Nothing Special   »   [go: up one dir, main page]

WO2019230547A1 - Brake control device and method for detecting malfunction in brake control device - Google Patents

Brake control device and method for detecting malfunction in brake control device Download PDF

Info

Publication number
WO2019230547A1
WO2019230547A1 PCT/JP2019/020428 JP2019020428W WO2019230547A1 WO 2019230547 A1 WO2019230547 A1 WO 2019230547A1 JP 2019020428 W JP2019020428 W JP 2019020428W WO 2019230547 A1 WO2019230547 A1 WO 2019230547A1
Authority
WO
WIPO (PCT)
Prior art keywords
liquid
hydraulic pressure
pressure
valve
brake
Prior art date
Application number
PCT/JP2019/020428
Other languages
French (fr)
Japanese (ja)
Inventor
秀章 矢頭
大澤　俊哉
旭 渡辺
周 加藤
Original Assignee
日立オートモティブシステムズ株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 日立オートモティブシステムズ株式会社 filed Critical 日立オートモティブシステムズ株式会社
Publication of WO2019230547A1 publication Critical patent/WO2019230547A1/en

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T17/00—Component parts, details, or accessories of power brake systems not covered by groups B60T8/00, B60T13/00 or B60T15/00, or presenting other characteristic features
    • B60T17/18—Safety devices; Monitoring
    • B60T17/22—Devices for monitoring or checking brake systems; Signal devices
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
    • B60T8/17—Using electrical or electronic regulation means to control braking
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
    • B60T8/32—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration
    • B60T8/34—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition
    • B60T8/48—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition connecting the brake actuator to an alternative or additional source of fluid pressure, e.g. traction control systems

Definitions

  • the present invention relates to a brake control device and an abnormality detection method for the brake control device.
  • a brake control device in which two brake systems connecting between the master cylinder and the wheel cylinder are connected by a communication fluid path, two communication valves are provided in the communication fluid path, and a discharge side of the pump is connected between the two communication valves, are known.
  • Patent Document 1 a fluid leakage system is detected based on the fluid pressures of both brake fluids when the pump is operated to alternately open and close both communication valves, and then the fluid pressures of both brake systems are predetermined.
  • a technique for detecting a liquid leakage system based on the hydraulic pressures of both brake systems after closing both communicating valves after increasing the hydraulic pressure to the above-described level is disclosed.
  • the brake control device detects the first communication valve detected by the pressure sensor in the first state in which the first communication valve is operated in the valve opening direction and the second communication valve is operated in the valve closing direction.
  • the brake control device in one embodiment of the present invention it is possible to suppress an increase in size and cost.
  • FIG. 1 is a schematic configuration diagram of a brake control device 1 of Embodiment 1.
  • FIG. It is a flowchart showing the state transition of each control state.
  • 3 is a flowchart illustrating a processing flow in a liquid leakage detection mode according to the first embodiment. It is a flowchart which shows the flow of a 1st liquid leak detection process.
  • FIG. 5 is a block diagram of hydraulic pressure feedback control in a first liquid leak detection unit 107. It is a flowchart which shows the flow of a 2nd liquid leak detection process.
  • 6 is a time chart showing the operation of the hydraulic pressure control unit 6 when only the first liquid leakage detection process is performed in the liquid leakage detection mode when a relatively large amount of liquid leakage occurs in the P system.
  • 7 is a time chart showing the operation of the hydraulic pressure control unit 6 when only the first liquid leakage detection process is performed in the liquid leakage detection mode when a relatively small amount of liquid leakage occurs in the P system.
  • 7 is a time chart showing the operation of the hydraulic pressure control unit 6 when only the second liquid leakage detection process is performed in the liquid leakage detection mode when a relatively small amount of liquid leakage occurs in the P system.
  • 6 is a time chart showing the operation of the hydraulic pressure control unit 6 in the liquid leakage detection mode of the first embodiment.
  • 6 is a flowchart illustrating a process flow in a liquid leakage detection mode according to the second embodiment.
  • FIG. 1 is a schematic configuration diagram of a brake control device 1 according to the first embodiment.
  • the brake control device 1 is a hydraulic brake device suitable for an electric vehicle.
  • the electric vehicle is a hybrid vehicle provided with a motor generator in addition to an engine as a prime mover for driving wheels, an electric vehicle provided with only a motor generator, or the like.
  • the brake control device 1 may be applied to a vehicle using only the engine as a driving force source.
  • the brake control device 1 supplies brake fluid to a wheel cylinder 8 provided on each wheel FL to RR (left front wheel FL, right front wheel FR, left rear wheel RL, right rear wheel RR) of the vehicle to provide brake fluid pressure ( Foil cylinder hydraulic pressure Pw) is generated.
  • the wheel cylinder 8 may be a wheel cylinder of a drum brake mechanism in addition to a cylinder of a hydraulic brake caliper in the disc brake mechanism.
  • the brake control device 1 has two systems, that is, a brake system (brake piping) of a P (primary) system and an S (secondary) system, and employs, for example, an X piping format. In addition, you may employ
  • the brake pedal 2 is a brake operation member that receives an input of a driver's brake operation.
  • the brake pedal 2 is a so-called suspension type, and its base end is rotatably supported by a shaft 201.
  • a pad 202 that is a target to be depressed by the driver is provided.
  • One end of the push rod 2a is rotatably connected to the base end side between the shaft 201 and the pad 202 of the brake pedal 2 by the shaft 203.
  • the master cylinder 3 is actuated by operation of the brake pedal 2 (brake operation) by the driver, and generates brake fluid pressure (master cylinder fluid pressure Pm).
  • the brake control device 1 does not include a negative pressure type booster that boosts or amplifies the brake operation force (stepping force F of the brake pedal 2) using intake negative pressure generated by the vehicle engine. For this reason, the brake control device 1 can be miniaturized and is optimal for an electric vehicle that does not have a negative pressure source (in many cases, an engine).
  • the master cylinder 3 is connected to the brake pedal 2 via the push rod 2a, and is supplied with brake fluid from the reservoir tank 4.
  • the reservoir tank 4 is a brake fluid source that stores brake fluid, and is a low pressure portion that is opened to atmospheric pressure.
  • the bottom side (vertically in the vertical direction) inside the reservoir tank 4 includes a primary hydraulic pressure chamber space 41P, a secondary hydraulic pressure chamber space 41S, and a pump suction space by a plurality of partition members having a predetermined height. It is divided into 42 (defined).
  • a liquid level sensor 94 that detects the level of the brake fluid amount in the reservoir tank is installed in the reservoir tank.
  • the liquid level sensor 94 is used to warn of a decrease in the liquid level in the reservoir tank 4, and includes a fixed member and a float member, and discretely detects the liquid level.
  • the fixing member is fixed to the inner wall of the reservoir tank 4 and has a switch. The switch is provided at a position that is substantially the same height as the liquid level.
  • the float member has buoyancy with respect to the brake fluid, and is provided so as to move up and down with respect to the fixed member in accordance with an increase or decrease in the amount of brake fluid (liquid level).
  • the switch provided on the fixed member switches from the off state to the on state. Thereby, a drop in the liquid level is detected.
  • the specific mode of the liquid level sensor 94 is not limited to the one that discretely detects the liquid level (switch) as described above, but is one that continuously detects the liquid level (analog detection). May be.
  • the master cylinder 3 is a tandem type and includes a primary piston 32P and a secondary piston 32S in series as a master cylinder piston that moves in the axial direction in response to a brake operation.
  • the primary piston 32P is connected to the push rod 2a.
  • the secondary piston 32S is a free piston type.
  • the brake pedal 2 is provided with a stroke sensor 90.
  • the stroke sensor 90 detects the amount of displacement of the brake pedal 2 (pedal stroke S).
  • the stroke sensor 90 may be provided on the push rod 2a or the primary piston 32P to detect the piston stroke Sp.
  • the pedal stroke S corresponds to a value obtained by multiplying the axial displacement (stroke amount) of the push rod 2a or the primary piston 32P by the pedal ratio K of the brake pedal.
  • K is a ratio of S to the stroke amount of the primary piston 32P, and is set to a predetermined value. K can be calculated, for example, by the ratio of the distance from the axis 201 to the pad 202 with respect to the distance from the axis 201 to the axis 203.
  • the stroke simulator 5 operates according to the driver's brake operation.
  • the stroke simulator 5 generates the pedal stroke S when the brake fluid that has flowed out from the inside of the master cylinder 3 flows into the stroke simulator 5 in accordance with the brake operation of the driver.
  • the brake fluid supplied from the master cylinder 3 operates the piston 52 of the stroke simulator 5 in the cylinder 50 in the axial direction. Thereby, the stroke simulator 5 generates an operation reaction force accompanying the brake operation of the driver.
  • the hydraulic pressure control unit 6 is a braking control unit that can generate the brake hydraulic pressure independently of the brake operation by the driver.
  • An electronic control unit (a control unit, hereinafter referred to as an ECU) 100 is a control unit that controls the operation of the hydraulic pressure control unit 6.
  • the hydraulic pressure control unit 6 receives supply of brake fluid from the reservoir tank 4 or the master cylinder 3.
  • the hydraulic pressure control unit 6 is provided between the wheel cylinder 8 and the master cylinder 3, and can supply the master cylinder hydraulic pressure Pm or the control hydraulic pressure to each wheel cylinder 8 individually.
  • the hydraulic control unit 6 has a motor 7a of a pump (hydraulic pressure source) 7 and a plurality of control valves (electromagnetic valve 26 and the like) as hydraulic equipment for generating a control hydraulic pressure.
  • the pump 7 draws in brake fluid from a brake fluid source other than the master cylinder 3 (reservoir tank 4 or the like) and discharges it toward the wheel cylinder 8.
  • the pump 7 is, for example, a plunger pump or a gear pump.
  • the pump 7 is used in common in both systems and is rotationally driven by an electric motor 7a as the same drive source. Examples of the motor 7a include a brushed DC motor and a brushless motor.
  • the electromagnetic valve 26 or the like opens and closes according to the control signal, and switches the communication state of the liquid path 11 and the like. Thereby, the flow of brake fluid is controlled.
  • the hydraulic pressure control unit 6 can pressurize the wheel cylinder 8 with the hydraulic pressure generated by the pump 7 in a state where the communication between the master cylinder 3 and the wheel cylinder 8 is cut off.
  • the hydraulic pressure control unit 6 includes hydraulic pressure sensors 91 and 93 that detect the discharge pressure of Pm and the pump 7.
  • the ECU 100 receives the detection values sent from the stroke sensor 90 and the hydraulic pressure sensors 91 and 93, and information related to the running state sent from the vehicle side.
  • the ECU 100 performs information processing according to a built-in program based on these various types of information.
  • command signals are output to the actuators of the hydraulic pressure control unit 6 according to the processing results to control them.
  • the opening / closing operation of the electromagnetic valve 26 and the like, and the rotation speed of the motor 7a that is, the discharge amount of the pump 7) are controlled.
  • various brake controls are realized by controlling the wheel cylinder hydraulic pressure Pw of each wheel FL to RR.
  • boost control For example, boost control, anti-lock control, brake control for vehicle motion control, automatic brake control, regenerative cooperative brake control, and the like are realized.
  • the boost control assists the brake operation by generating a hydraulic braking force that is insufficient for the driver's brake operation force.
  • Anti-lock control suppresses slipping (lock tendency) of the wheels FL to RR due to braking.
  • Vehicle motion control is vehicle behavior stabilization control (ESC) that prevents skidding and the like.
  • the automatic brake control is a preceding vehicle following control or the like.
  • the regenerative cooperative brake control controls the wheel cylinder hydraulic pressure Pw so as to achieve the target deceleration (target braking force) in cooperation with the regenerative brake.
  • a primary hydraulic chamber 31P is defined between both pistons 32P and 32S of the master cylinder 3.
  • the coil spring 33P is installed in a compressed state.
  • a secondary hydraulic pressure chamber 31S is defined between the piston 32S and the positive end of the cylinder 30 in the x-axis direction.
  • the coil spring 33S is installed in a compressed state.
  • a first liquid passage 11 is opened in each of the hydraulic chambers 31P and 31S.
  • the hydraulic chambers 31P and 31S are connected to the hydraulic pressure control unit 6 through the first liquid passage 11 and are provided so as to communicate with the wheel cylinder 8.
  • the piston 32 is stroked by the depression of the brake pedal 2 by the driver, and the hydraulic pressure Pm is generated as the volume of the hydraulic pressure chamber 31 decreases. Approximately the same Pm is generated in both hydraulic pressure chambers 31P and 31S. As a result, the brake fluid is supplied from the hydraulic chamber 31 to the wheel cylinder 8 through the first fluid path 11.
  • the master cylinder 3 pressurizes the P system wheel cylinders (first braking force applying portions) 8a and 8d through the P system fluid passage (first fluid passage 11P) by Pm generated in the primary fluid pressure chamber 31P. Is possible.
  • the master cylinder 3 causes the wheel cylinders (second braking force applying portions) 8b and 8c of the S system to pass through the S system fluid path (first fluid path 11S) by Pm generated in the secondary hydraulic pressure chamber 31S. Pressurization is possible.
  • FIG. 1 shows a cross section passing through the axis of the cylinder 50 of the stroke simulator 5.
  • the cylinder 50 is cylindrical and has a cylindrical inner peripheral surface.
  • the cylinder 50 has a relatively small-diameter piston accommodating portion 501 on the x-axis negative direction side and a relatively large-diameter spring accommodating portion 502 on the x-axis positive direction side.
  • the piston 52 is installed on the inner peripheral side of the piston accommodating portion 501 so as to be movable in the x-axis direction along the inner peripheral surface thereof.
  • the piston 52 is a separation member (partition wall) that separates the inside of the cylinder 50 into at least two chambers (a positive pressure chamber 511 and a back pressure chamber 512).
  • a positive pressure chamber 511 is defined on the x-axis negative direction side of the piston 52
  • a back pressure chamber 512 is defined on the x-axis positive direction side.
  • the positive pressure chamber 511 is a space surrounded by the surface of the piston 52 on the x-axis negative direction side and the inner peripheral surface of the cylinder 50 (piston accommodating portion 501).
  • the second liquid path 12 always opens to the positive pressure chamber 511.
  • the back pressure chamber 512 is a space surrounded by the surface on the x-axis positive direction side of the piston 52 and the inner peripheral surface of the cylinder 50 (spring accommodating portion 502, piston accommodating portion 501).
  • the liquid passage 13A always opens into the back pressure chamber 512.
  • a piston seal 54 is installed on the outer periphery of the piston 52 so as to extend in the direction around the axis of the piston 52 (circumferential direction).
  • the piston seal 54 is in sliding contact with the inner peripheral surface of the cylinder 50 (piston accommodating portion 501), and seals between the inner peripheral surface of the piston accommodating portion 501 and the outer peripheral surface of the piston 52.
  • the piston seal 54 is a separation seal member that seals between the positive pressure chamber 511 and the back pressure chamber 512 to separate them liquid-tightly, and complements the function of the piston 52 as the separation member.
  • the spring 53 is a coil spring installed in a compressed state in the back pressure chamber 512, and always urges the piston 52 to the x axis negative direction side.
  • the spring 53 is provided so as to be deformable in the x-axis direction, and can generate a reaction force according to the displacement amount (stroke amount) of the piston 52.
  • the spring 53 has a first spring 531 and a second spring 532.
  • the first spring 531 is smaller in diameter and shorter than the second spring 532, and has a smaller wire diameter.
  • the spring constant of the first spring 531 is smaller than that of the second spring 532.
  • the first and second springs 531 and 532 are arranged in series via the retainer member 530 between the piston 52 and the cylinder 50 (spring accommodating portion 502).
  • the members corresponding to the wheels FL to RR are appropriately distinguished by adding suffixes a to d at the end of the reference numerals.
  • the first fluid path 11 connects the fluid pressure chamber 31 of the master cylinder 3 and the wheel cylinder 8.
  • the shut-off valve 21 is a normally open type solenoid valve (opened in a non-energized state) provided in the first liquid passage 11.
  • the first liquid path 11 is separated by a shutoff valve 21 into a liquid path 11A on the master cylinder 3 side and a liquid path 11B on the wheel cylinder 8 side.
  • the solenoid-in valve (SOL / V IN) 25 is located closer to the wheel cylinder 8 (liquid path 11B) than the shut-off valve 21 in the first liquid path 11 and corresponds to each wheel FL to RR (to the liquid paths 11a to 11d). ) This is a normally open solenoid valve.
  • the first liquid passages 11P, 11a, and 11d are first connection liquid passages, and the first liquid passages 11S, 11b, and 11c are second connection liquid passages.
  • a bypass liquid path 120 is provided in parallel with the first liquid path 11 by bypassing the SOL / V IN 25.
  • the bypass fluid path 120 is provided with a check valve (one-way valve or check valve) 250 that allows only the flow of brake fluid from the wheel cylinder 8 side to the master cylinder 3 side.
  • the suction liquid path 15 is a liquid path that connects the reservoir tank 4 (pump suction space 42) and the suction part 70 of the pump 7.
  • the discharge liquid path 16 connects the discharge section 71 of the pump 7 and the shut-off valve 21 and the SOL / V IN 25 in the first liquid path 11B.
  • the check valve 160 is provided in the discharge liquid passage 16 and allows only the flow of brake fluid from the discharge portion 71 side (upstream side) of the pump 7 to the first liquid passage 11 side (downstream side).
  • the check valve 160 is a discharge valve provided in the pump 7.
  • the discharge liquid path 16 branches into a P-system liquid path 16P and an S-system liquid path 16S on the downstream side of the check valve 160.
  • the liquid passages 16P and 16S are connected to the first liquid passage 11P of the P system and the first liquid passage 11S of the S system, respectively.
  • the liquid paths 16P and 16S function as communication liquid paths that connect the first liquid paths 11P and 11S to each other.
  • the communication valve (first communication valve) 26P is a normally closed electromagnetic valve (closed in a non-energized state) provided in the liquid passage 16P.
  • the communication valve (second communication valve) 26S is a normally closed electromagnetic valve provided in the liquid path 16S.
  • the pump 7 is a second hydraulic pressure source capable of generating the wheel cylinder hydraulic pressure Pw by generating the hydraulic pressure in the first liquid passage 11 by the brake fluid supplied from the reservoir tank 4.
  • the pump 7 is connected to the wheel cylinders 8a to 8d via the communication liquid path (discharge liquid paths 16P, 16S) and the first liquid paths 11P, 11S, and is connected to the communication liquid paths (discharge liquid paths 16P, 16S).
  • the wheel cylinder 8 can be pressurized by discharging the brake fluid.
  • the first depressurizing liquid path 17 connects the suction liquid path 15 between the check valve 160 and the communication valve 26 in the discharge liquid path 16.
  • the pressure regulating valve 27 is a normally open type electromagnetic valve as a first pressure reducing valve provided in the first pressure reducing liquid passage 17.
  • the pressure regulating valve 27 may be a normally closed type.
  • the second depressurization liquid path 18 connects the suction liquid path 15 to the wheel cylinder 8 side with respect to the SOL / V IN 25 in the first liquid path 11B.
  • the solenoid-out valve (SOL / V OUT) 28 is a normally closed electromagnetic valve as a second pressure reducing valve provided in the second pressure reducing liquid path 18.
  • the first depressurizing liquid path 17 on the suction liquid path 15 side from the pressure regulating valve 27 and the second depressurizing liquid path 18 on the suction liquid path 15 side from the SOL / V OUT 28 are partially provided.
  • the second liquid path 12 is a branched liquid path that branches from the first liquid path 11B and connects to the stroke simulator 5.
  • the second liquid path 12 functions as a positive pressure side liquid path that connects the secondary hydraulic pressure chamber 31S of the master cylinder 3 and the positive pressure chamber 511 of the stroke simulator 5 together with the first liquid path 11B.
  • the second fluid passage 12 may directly connect the secondary fluid pressure chamber 31S and the positive pressure chamber 511 without passing through the first fluid passage 11A.
  • the third liquid path 13 is a first back pressure side liquid path that connects the back pressure chamber 512 of the stroke simulator 5 and the first liquid path 11. Specifically, the third liquid path 13 branches from between the shutoff valve 21S and the SOL / V IN 25 in the first liquid path 11S (liquid path 11B) and is connected to the back pressure chamber 512.
  • the stroke simulator in valve SS / V IN23 is a normally closed electromagnetic valve provided in the third liquid passage 13.
  • the third liquid path 13 is separated into a liquid path 13A on the back pressure chamber 512 side and a liquid path 13B on the first liquid path 11 side by SS / V IN23.
  • a bypass liquid path 130 is provided in parallel with the third liquid path 13 by bypassing the SS / V IN 23.
  • the bypass liquid path 130 connects the liquid path 13A and the liquid path 13B.
  • a check valve 230 is provided in the bypass liquid passage 130. The check valve 230 allows the brake fluid to flow from the back pressure chamber 512 side (fluid passage 13A) toward the first fluid passage 11 side (fluid passage 13B) and suppresses the flow of brake fluid in the reverse direction.
  • the fourth liquid path 14 is a second back pressure side liquid path that connects the back pressure chamber 512 of the stroke simulator 5 and the reservoir tank 4.
  • the fourth liquid path 14 is located between the back pressure chamber 512 and the SS / V IN 23 (liquid path 13A) in the third liquid path 13 and on the suction liquid path 15 side of the suction liquid path 15 (or the pressure regulating valve 27).
  • the first depressurizing liquid path 17 and the second depressurizing liquid path 18) closer to the suction liquid path 15 than the SOL / V OUT28 are connected.
  • the fourth liquid passage 14 may be directly connected to the back pressure chamber 512 or the reservoir tank 4.
  • the stroke simulator out valve (simulator cut valve) SS / V OUT24 is a normally closed solenoid valve provided in the fourth liquid passage 14.
  • a bypass liquid path 140 is provided in parallel with the fourth liquid path.
  • the bypass fluid path 140 permits the flow of brake fluid from the reservoir tank 4 (suction fluid path 15) side to the third fluid path 13A side, that is, the back pressure chamber 512 side, and suppresses the brake fluid flow in the reverse direction.
  • a check valve 240 is provided.
  • the shut-off valve 21, the SOL / V IN 25, and the pressure regulating valve 27 are proportional control valves in which the valve opening is adjusted according to the current supplied to the solenoid.
  • the other valves that is, SS / V IN23, SS / V OUT24, communication valve 26, and SOL / V OUT28 are two-position valves (on / off valves) in which the opening / closing of the valves is controlled by binary switching. It is also possible to use a proportional control valve as the other valve.
  • the fluid pressure at this location (the fluid pressure in the master cylinder fluid pressure Pm and the positive pressure chamber 511 of the stroke simulator 5) is set.
  • a hydraulic pressure sensor 91 for detection is provided.
  • a hydraulic pressure sensor (pressure sensor) 93 for detecting the hydraulic pressure (pump discharge pressure) at this point is provided. ing.
  • a brake system (first fluid path 11) that connects the hydraulic chamber 31 of the master cylinder 3 and the wheel cylinder 8 in a state where the shutoff valve 21 is controlled in the valve opening direction constitutes a first system.
  • This first system can realize pedal force braking (non-boosting control) by generating the wheel cylinder hydraulic pressure Pw by the master cylinder hydraulic pressure Pm generated using the pedal effort F.
  • the brake system suction fluid path 15, discharge fluid path 16, etc.
  • the pump 7 and connecting the reservoir tank 4 and the wheel cylinder 8 with the shut-off valve 21 controlled in the valve closing direction is the second Configure the system.
  • This second system constitutes a so-called brake-by-wire device that generates the wheel cylinder hydraulic pressure Pw by the hydraulic pressure generated using the pump 7, and can realize boost control or the like as brake-by-wire control.
  • brake-by-wire control (hereinafter simply referred to as “by-wire control”), the stroke simulator 5 generates an operation reaction force accompanying a driver's brake operation.
  • the ECU 100 includes a by-wire control unit 101, a pedal force brake unit 102, and a fail safe unit 103.
  • the by-wire control unit 101 closes the shut-off valve 21 and pressurizes the wheel cylinder 8 by the pump 7 according to the brake operation state of the driver.
  • the by-wire control unit 101 includes a brake operation state detection unit 104, a target wheel cylinder hydraulic pressure calculation unit 105, and a wheel cylinder hydraulic pressure control unit.
  • the brake operation state detection unit 104 receives the input of the value detected by the stroke sensor 90, and detects the pedal stroke S as a brake operation amount by the driver. Further, based on S, it is detected whether or not the driver is operating the brake (whether or not the brake pedal 2 is operated).
  • a pedal force sensor for detecting the pedal force F may be provided, and the brake operation amount may be detected or estimated based on the detected value. Further, the brake operation amount may be detected or estimated based on the detection value of the hydraulic pressure sensor 91. That is, the brake operation amount used for the control is not limited to S, and other appropriate variables may be used.
  • the target wheel cylinder hydraulic pressure calculation unit 105 calculates the target wheel cylinder hydraulic pressure Pw *.
  • boost control based on the detected pedal stroke S (brake operation amount), between S and the driver's required brake hydraulic pressure (vehicle deceleration requested by the driver) according to a predetermined boost ratio
  • a predetermined boost ratio For example, in a brake device equipped with a normal size negative pressure booster, a predetermined relationship between the pedal stroke S and the wheel cylinder hydraulic pressure Pw (braking force) realized when the negative pressure booster is operated, The above ideal relationship for calculating the target wheel cylinder hydraulic pressure Pw * is obtained.
  • the wheel cylinder hydraulic pressure control unit 106 generates the wheel cylinder hydraulic pressure Pw by the pump 7 (second system) by controlling the shut-off valve 21 in the valve closing direction.
  • Control possible state.
  • hydraulic pressure control for example, boost control
  • the shutoff valve 21 is controlled in the valve closing direction
  • the communication valve 26 is controlled in the valve opening direction
  • the pressure regulating valve 27 is controlled in the valve closing direction
  • the pump 7 is operated.
  • the brake fluid discharged from the pump 7 flows into the first liquid path 11B via the discharge liquid path 16.
  • each wheel cylinder 8 is pressurized. That is, the wheel cylinder 8 is pressurized using the hydraulic pressure generated in the first liquid passage 11B by the pump 7.
  • feedback control is performed on the rotational speed of the pump 7 and the valve opening state (opening degree, etc.) of the pressure regulating valve 27 so that the detected value of the hydraulic pressure sensor 93 approaches the target wheel cylinder hydraulic pressure Pw *. Power is obtained. That is, the wheel cylinder hydraulic pressure Pw is adjusted by controlling the valve opening state of the pressure regulating valve 27 and appropriately leaking the brake fluid from the discharge fluid passage 16 or the first fluid passage 11 to the suction fluid passage 15 through the pressure regulating valve 27. it can.
  • the wheel cylinder hydraulic pressure Pw is controlled by changing the valve opening state of the pressure regulating valve 27, not the rotational speed of the pump 7 (motor 7a).
  • the shut-off valve 21 in the valve closing direction and shutting off the master cylinder 3 side and the wheel cylinder 8 side, the wheel cylinder hydraulic pressure Pw can be easily controlled independently of the driver's brake operation.
  • control SS / V OUT24 in the valve opening direction.
  • the back pressure chamber 512 of the stroke simulator 5 communicates with the suction liquid passage 15 (reservoir tank 4) side.
  • the brake fluid is discharged from the master cylinder 3, and when this brake fluid flows into the positive pressure chamber 511 of the stroke simulator 5, the piston 52 is activated. As a result, a pedal stroke Sp is generated. Brake fluid having the same amount as that flowing into the positive pressure chamber 511 flows out from the back pressure chamber 512.
  • the brake fluid is discharged to the suction fluid passage 15 (reservoir tank 4) through the third fluid passage 13A and the fourth fluid passage 14.
  • the fourth fluid passage 14 need only be connected to a low-pressure portion through which brake fluid can flow, and need not necessarily be connected to the reservoir tank 4.
  • an operation reaction force (pedal reaction force) acting on the brake pedal 2 is generated by the force by which the hydraulic pressure of the spring 53 of the stroke simulator 5 and the back pressure chamber 512 pushes the piston 52. That is, the stroke simulator 5 generates a characteristic of the brake pedal 2 (FS characteristic that is a relation of S to F) during the by-wire control.
  • the pedal force brake unit 102 opens the shut-off valve 21 and pressurizes the wheel cylinder 8 by the master cylinder 3.
  • the hydraulic pressure control unit 6 is brought into a state in which the wheel cylinder hydraulic pressure Pw can be generated by the master cylinder hydraulic pressure Pm (first system), and a pedaling force brake is realized.
  • the stroke simulator 5 is deactivated in response to the driver's brake operation.
  • the brake fluid is efficiently supplied from the master cylinder 3 toward the wheel cylinder 8. Therefore, it is possible to suppress a decrease in the wheel cylinder hydraulic pressure Pw that is generated by the pedaling force F by the driver.
  • the pedal effort brake unit 102 deactivates all the actuators in the hydraulic pressure control unit 6.
  • SS / V IN 23 may be controlled in the valve opening direction.
  • the fail safe unit 103 detects the occurrence of an abnormality (failure or failure) in the brake control device 1.
  • a failure of an actuator (pump 7 or motor 7a, pressure regulating valve 27, etc.) in the hydraulic pressure control unit 6 is detected based on a signal from the brake operation state detection unit 104 or a signal from each sensor.
  • an abnormality is detected in the in-vehicle power source (battery) that supplies power to the brake control device 1 or the ECU 100.
  • fail-safe unit 103 When fail-safe unit 103 detects the occurrence of an abnormality during the by-wire control, it switches control according to the abnormal state. For example, when it is determined that the hydraulic pressure control by the by-wire control cannot be continued, the pedal force brake unit 102 is operated to switch from the by-wire control to the pedal force brake. Specifically, all the actuators in the hydraulic pressure control unit 6 are deactivated and shifted to the pedal effort brake.
  • the shut-off valve 21 is a normally open valve, it is possible to automatically realize pedal force braking by opening the shut-off valve 21 when the power supply fails.
  • SS / V OUT24 is a normally closed valve, the stroke simulator 5 is automatically deactivated by closing SS / V OUT24 when the power fails.
  • the communication valve 26 is a normally closed type, the brake fluid pressure systems of both systems are made independent of each other when the power fails, and the wheel cylinder can be pressurized by the pedaling force F in each system separately.
  • the fail safe unit 103 detects a brake system (liquid leakage system) in which a liquid leakage failure has occurred among the two brake systems.
  • the leak point of the brake system is the brake piping that connects the housing of the hydraulic control unit 6 and the wheel cylinder 8, but the hydraulic pressure of the brake system also decreases due to the open fixing of the SOL / V OUT28. .
  • the hydraulic pressure drop due to the open fixing of the SOL / V OUT28 is also treated as a brake system liquid leak.
  • the by-wire control unit 101 performs the by-wire control only with the brake system (normal system) in which no liquid leakage has occurred (this is referred to as one-system boost control). Call).
  • the operation of the shut-off valve 21, the pressure regulating valve 27, and the pump 7 is the same as in normal control (normal by-wire control), but the communication valve 26 on the liquid leakage system side is closed to close the liquid leakage system. Shut off the side communication fluid path. Thereby, the wheel cylinder hydraulic pressure Pw of the normal system can be controlled.
  • FIG. 2 is a flowchart showing the state transition of each control state. This process is implemented as a program in the ECU 100 and executed at predetermined intervals.
  • the fail safe unit 103 determines whether or not the brake level stored in the reservoir tank 4 is lowered based on the signal from the level sensor 94. If YES, the process proceeds to step S3. If NO, the process proceeds to step S2.
  • the by-wire control unit 101 executes the normal control mode.
  • the normal control mode is a mode in which normal by-wire control is performed by the by-wire control unit 101.
  • the fail safe unit 103 determines whether the liquid leakage system has been detected. If YES, the process proceeds to step S5. If NO, the process proceeds to step S4.
  • step S4 the fail safe unit 103 executes the liquid leak detection mode.
  • the liquid leakage detection mode is a mode for detecting a liquid leakage system. Details of the liquid leakage detection mode will be described later.
  • step S5 the fail safe unit 103 determines whether the liquid leakage system is the P system. If YES, the process proceeds to step S6. If NO, the process proceeds to step S7.
  • step S6 the by-wire control unit 101 executes the S-system single-system boost mode.
  • the single system boost mode of the S system is a mode in which the by-wire control unit 101 performs the by-wire control only in the S system. When the leakage of the P system is detected, one-system boost control is performed using the normal S system.
  • step S7 the fail safe unit 103 determines whether the liquid leakage system is the S system. If YES, the process proceeds to step S8. If NO, the process proceeds to step S9.
  • step S8 the by-wire control unit 101 executes the single system boost mode of the P system.
  • the single system boost mode of the P system is a mode in which the by-wire control unit 101 performs the by-wire control only in the P system. If a liquid leakage failure is detected in the S system, the single system boost control is performed in the normal P system.
  • step S9 the by-wire control unit 101 continues the boost control of both the P and S systems.
  • the liquid level of the reservoir tank 4 decreases. Further, the liquid level of the reservoir tank 4 also decreases when a liquid leak occurs on the master cylinder side (liquid path 11A) with respect to the shutoff valve 21 of the first liquid path 11. In these cases, boost control can be continued, but the amount of brake fluid that can be used has decreased. It is preferable to prohibit brake control, automatic brake control, etc., and to prompt the driver for maintenance.
  • FIG. 3 is a flowchart illustrating a processing flow in the liquid leakage detection mode of the first embodiment.
  • the fail safe unit 103 of the ECU 100 includes a first liquid leak detection unit 107, a second liquid leak detection unit 108, a two-system hydraulic pressure generation possibility determination unit 109, and a vehicle travel stop state as a configuration for executing the liquid leak detection mode. It has a determination unit 110, a second liquid leak detection execution state determination unit 111, and a vehicle braking request determination unit 112.
  • step S101 the vehicle travel stop state determination unit 110 determines whether the vehicle is stopped. If YES, the process proceeds to step S106, and if NO, the process proceeds to step S102.
  • step S102 signals from each wheel speed sensor mounted on the vehicle corresponding to each wheel FL to RR are input, and the vehicle stops when each wheel speed is 0 (including almost 0). It is determined that In step S102, the vehicle braking request determination unit 112 determines whether there is a braking request. If YES, the process proceeds to step S103, and if NO, this process ends. In this step, based on information from the brake operation state detection unit 104 or the target wheel cylinder hydraulic pressure calculation unit 105, it is determined whether there is a braking request for the vehicle. For example, when S is other than 0, it is determined that there is a braking request because the driver is stepping on the brake pedal 2. In step S103, the target wheel cylinder hydraulic pressure Pw * is set based on the information from the target foil cylinder hydraulic pressure calculation unit 105.
  • step S104 the first liquid leak detection unit 107 executes a first liquid leak detection process. Details of the first liquid leakage detection process will be described later.
  • step S105 the fail safe unit 103 determines whether a liquid leakage system has been detected. If YES, the process proceeds to step S109, and if NO, this process ends.
  • step S106 in the fail safe unit 103, the target wheel cylinder hydraulic pressure Pw * is set to a predetermined hydraulic pressure Pws for detecting a leakage at the time of stopping. Pws is higher than the target wheel cylinder hydraulic pressure Pw * calculated by the target wheel cylinder hydraulic pressure calculation unit 105. Thereby, the outflow speed when the liquid leak has occurred can be increased, and the detectability can be improved.
  • step S107 the first liquid leak detection unit 107 executes a first liquid leak detection process.
  • step S108 the fail-safe unit 103 determines whether a liquid leakage system has been detected. If YES, the process proceeds to step S109, and if NO, the process proceeds to step S111.
  • step S109 the fail safe unit 103 stores the liquid leakage system.
  • step S110 the fail safe unit 103 determines that the liquid leakage system has been detected, and ends this process.
  • both system hydraulic pressure generation possibility determination unit 109 confirms whether hydraulic pressure has been generated in both systems P and S.
  • the occurrence of hydraulic pressure can be determined by the fact that the value detected by the hydraulic pressure sensor 93 is almost the same as the predetermined hydraulic pressure Pws for detecting leakage when the vehicle is stopped (the differential pressure is small). It is desirable that the condition be continued for a predetermined time.
  • step S112 the fail-safe unit 103 determines whether the generation of hydraulic pressure has been confirmed in both the P and S systems. If YES, the process proceeds to step S113, and if NO, this process ends.
  • step S113 the second liquid leak detection unit 108 executes a second liquid leak detection process. Details of the second liquid leakage detection process will be described later.
  • step S114 the failsafe unit 103 determines whether a liquid leakage system has been detected. If YES, the process proceeds to step S109, and if NO, the process proceeds to step S115.
  • step S115 the second liquid leak detection execution state determination unit 111 determines whether the control of the P system and the S system has been completed in the second liquid leak detection process by the second liquid leak detection unit 108.
  • step S116 the fail safe unit 103 determines that the liquid level of the reservoir tank 4 has decreased due to reasons other than the fluid leakage failure of the wheel cylinder 8, and stores the information.
  • the execution time of the second liquid leakage detection process exceeds the predetermined time, the liquid leakage detection mode is terminated because the liquid leakage of the wheel cylinder 8 to be detected in the process has not occurred.
  • FIG. 4 is a flowchart showing the flow of the first liquid leakage detection process.
  • step S201 the motor 7a is operated and the shutoff valves 21P and 21S are closed.
  • step S202 control system switching processing is performed. The switching of the control system is to selectively switch the control of the P system and the control of the S system. In the first embodiment, this switching is performed for a predetermined time (for example, 150 ms).
  • step S203 it is determined whether the P system is selected as the current control system. If YES, the process proceeds to step S204. If NO, the process proceeds to step S205.
  • step S204 the communication valve 26P is opened, the communication valve 26S is closed, and the feedback hydraulic pressure for wheel cylinder hydraulic pressure control is set to the value detected by the hydraulic pressure sensor 93.
  • step S205 the communication valve 26P is closed, the communication valve 26S is opened, and the feedback hydraulic pressure for wheel cylinder hydraulic pressure control is set to the value detected by the hydraulic pressure sensor 93.
  • step S206 hydraulic pressure feedback control is performed so that the target wheel cylinder hydraulic pressure Pw * matches the wheel cylinder hydraulic pressure Pw of the control system by adjusting the rotation speed of the pump 7 and the opening of the pressure regulating valve 27.
  • FIG. 5 is a block diagram of the hydraulic pressure feedback control in the first liquid leak detection unit 107.
  • the feedback hydraulic pressure is configured to match the target wheel cylinder hydraulic pressure Pw *.
  • the feedback hydraulic pressure is the hydraulic pressure of the system in which the communication valve (26P or 26S) is open. This is because only the system in which the communication valve is open can adjust the wheel cylinder hydraulic pressure by the pump 7 and the pressure regulating valve 27.
  • the first liquid leak detection unit 107 inputs a hydraulic pressure deviation between the target wheel cylinder hydraulic pressure Pw * and the feedback hydraulic pressure to the hydraulic pressure controller 107a.
  • the hydraulic pressure controller 107a controls the rotational speed of the pump 7 and the current (opening degree) of the pressure regulating valve 27 so as to eliminate the hydraulic pressure deviation. Thereby, the hydraulic pressure control unit 6 operates so as to output the wheel cylinder hydraulic pressure Pw.
  • step S207 it is determined whether the control system has just been switched from the P system to the S system. If YES, the process proceeds to step S209. If NO, the process proceeds to step S208. In step S208, it is determined whether the control system has just been switched from the S system to the P system. If YES, the process proceeds to step S210. If NO, the process proceeds to step S211. In step S209, the value detected by the hydraulic pressure sensor 93 is stored as the primary system hydraulic pressure Ppri. In step S210, the value detected by the hydraulic pressure sensor 93 is stored as the secondary system hydraulic pressure Psec. In step S211, it is determined whether the control of the P system and the S system has been completed for one cycle.
  • step S212 a differential pressure ⁇ P between the hydraulic pressures (primary system hydraulic pressure Ppri, secondary system hydraulic pressure Psec) stored in steps S209 and S210 is calculated.
  • step S213 it is determined whether or not the absolute value
  • step S214 a system with a low hydraulic pressure among both P and S systems is determined as a faulty system.
  • FIG. 6 is a flowchart showing the flow of the second liquid leakage detection process.
  • control system switching processing is performed.
  • the switching of the control system is to selectively switch the control of the P system, the re-boosting control, and the control of the S system. In the first embodiment, this switching is performed for a predetermined time (for example, 1 s).
  • re-boosting control is performed during the switching of the control system, which is different from step S202. Further, the switching time of the control system and the switching time of the re-boosting control may be set separately.
  • step S302 it is determined whether the P system is selected as the current control system. If YES, the process proceeds to step S303, and if NO, the process proceeds to step S304.
  • step S303 the motor 7a is deactivated, the pressure regulating valve 27 and the shutoff valves 21P and 21S are closed, the communication valve 26P is opened, and the communication valve 26S is closed.
  • the fluid paths 11B (11P), 11a, 11d of the P system, the wheel cylinders 8a, 8d and the fluid paths 16P, 16S are closed circuits, and the fluid pressure of the P system can be maintained when there is no liquid leakage. Become. If there is a fluid leak in the P system, the fluid pressure in the P system (the value of the fluid pressure sensor 93) decreases.
  • step S304 it is determined whether the S system is selected as the current control system.
  • step S305 the motor 7a is deactivated, the pressure regulating valve 27 and the shutoff valves 21P and 21S are closed, the communication valve 26P is closed, and the communication valve 26S is opened.
  • the S system fluid passages 11B (11S), 11b, 11c, the wheel cylinders 8b, 8c and the fluid passages 16P, 16S are closed circuits, and the fluid pressure of the S system can be maintained when there is no liquid leakage. Become. If there is a liquid leak, the hydraulic pressure of the S system (the value of the hydraulic pressure sensor 93) decreases.
  • step S306 it is determined whether or not the control system before the transition to the repressurization control is the P system. If YES, the process proceeds to step S307, and if NO, the process proceeds to step S308. In step S307, the motor 7a is operated, the communication valve 26P is closed, the communication valve 26S is opened, and the feedback hydraulic pressure for wheel cylinder hydraulic pressure control is set to the value detected by the hydraulic pressure sensor 93.
  • step S308 the motor 7a is operated, the communication valve 26P is opened, the communication valve 26S is closed, and the feedback hydraulic pressure for wheel cylinder hydraulic pressure control is set to the value detected by the hydraulic pressure sensor 93.
  • step S309 the same hydraulic pressure feedback control as in step S206 is performed.
  • step S310 it is determined whether the P system control has just ended. If YES, the process proceeds to step S312. If NO, the process proceeds to step S311.
  • step S311 it is determined whether the S system control has just ended. If YES, the process proceeds to step S313, and if NO, the process proceeds to step S314.
  • step S312 the value detected by the hydraulic pressure sensor 93 is stored as the primary system hydraulic pressure Ppri.
  • step S313 the value detected by the hydraulic pressure sensor 93 is stored as the secondary system hydraulic pressure Psec.
  • step S314 it is determined whether the control of the P system and the S system has been completed for one cycle. If YES, the process proceeds to step S315, and if NO, this process ends.
  • step S315 the differential pressure ⁇ P between the hydraulic pressures (primary system hydraulic pressure Ppri and secondary system hydraulic pressure Psec) of each system stored in steps S312 and S313 is calculated.
  • step S316 it is determined whether the absolute value
  • FIG. 7 is a time chart showing the operation of the hydraulic pressure control unit 6 when only the first liquid leakage detection process is performed in the liquid leakage detection mode, and a relatively large amount of liquid leakage (opening of the liquid leakage portion) is performed in the P system. Occurs when the area is large).
  • the target wheel cylinder hydraulic pressure Pw * is 0 [Mpa], so it is in an uncontrolled state, the shutoff valves 21P and 21S and the pressure regulating valve 27 are open, and the communication valves 26P and 26S are closed.
  • the motor 7a is OFF (inactive).
  • the target wheel cylinder hydraulic pressure Pw * is generated, and hydraulic pressure control is started.
  • the shutoff valves 21P and 21S are closed, the motor 7a is turned on (actuated), and the pressure regulating valve 27 is closed (proportional control).
  • the P system is selected as the control system (determined by the control system switching process in S202).
  • the P system communication valve 26P is opened and the S system communication valve 26S is closed.
  • servo control is performed so that the value detected by the hydraulic pressure sensor 93 matches the target wheel cylinder hydraulic pressure Pw *.
  • the hydraulic pressure in the P system increases, and in the S system, the shutoff valve 21S and the communication valve 26S are both closed to form a closed circuit, so that the hydraulic pressure remains zero.
  • the increase in the hydraulic pressure of the P system in which the liquid leakage has occurred is due to a loss due to the flow of the brake fluid.
  • the degree of generated hydraulic pressure is inversely proportional to the square of the opening area of the outflow part due to the nature of the fluid, and can be approximated to be proportional to the square of the flow rate from the hydraulic pressure source (pump 7). Since the supply flow rate is limited, a large hydraulic pressure cannot be generated when a large amount of leakage occurs.
  • the control system is switched from the P system to the S system, and the value detected by the hydraulic pressure sensor 93 is stored as the primary system hydraulic pressure Ppri.
  • the control system switches to the S system in the sections T11 to T12.
  • the S system communication valve 26S is opened, and the P system communication valve 26P is closed.
  • servo control is performed so that the value detected by the hydraulic pressure sensor 93 coincides with the target wheel cylinder hydraulic pressure Pw *. Therefore, in the section T11 to T12, the hydraulic pressure in the S system increases, and in the P system, the shutoff valve 21P and the communication valve 26P are both closed to form a closed circuit, so the hydraulic pressure should be maintained. .
  • the brake fluid flows out to the outside in the sections T11 to T12, and the fluid pressure decreases.
  • the control system is switched from the S system to the P system, and the value detected by the hydraulic pressure sensor 93 is stored as the secondary system hydraulic pressure Psec.
  • a differential pressure ⁇ P between the primary system hydraulic pressure Ppri and the secondary system hydraulic pressure Psec is calculated in S212.
  • of the differential pressure ⁇ P in S213 is equal to or greater than the predetermined abnormal differential pressure threshold value P1 is No, the first liquid leakage detection process is continued.
  • the control system is switched to the P system.
  • the hydraulic pressure of the P system increases and the hydraulic pressure of the S system is maintained.
  • the control system is switched from the P system to the S system, and the value detected by the hydraulic pressure sensor 93 is stored as the primary system hydraulic pressure Ppri.
  • the control system and the like are switched to the S system.
  • the hydraulic pressure of the S system increases, and the hydraulic pressure of the P system decreases due to the influence of liquid leakage.
  • the control system is switched from the S system to the P system, and the value detected by the hydraulic pressure sensor 93 is stored as the secondary system hydraulic pressure Psec.
  • a differential pressure ⁇ P between the primary system hydraulic pressure Ppri and the secondary system hydraulic pressure Psec is calculated in S212.
  • the first liquid leakage detection process is continued.
  • the differential pressure ⁇ P between the hydraulic pressure of the P system and the hydraulic pressure of the S system gradually increases, and when ⁇ P reaches the abnormal differential pressure threshold P1 at time T16, the hydraulic pressure of the P system is lost. A fall is detected.
  • the first liquid leak detection process by alternately switching between the P system and the S system and repeating the pressure increase and the fluid pressure holding, the fluid pressure is stably generated in the normal system, A leak system can be detected.
  • FIG. 8 is a time chart showing the operation of the hydraulic pressure control unit 6 when only the first liquid leakage detection process is performed in the liquid leakage detection mode, and a relatively small amount of liquid leakage (opening of the liquid leakage portion) is performed in the P system. Occurs when the area is small).
  • the target wheel cylinder hydraulic pressure Pw * is 0 [MPa]
  • it is in an uncontrolled state.
  • target wheel cylinder hydraulic pressure Pw * is generated, and hydraulic pressure control is started.
  • the P system is selected as the control system, the P system is increased in pressure, and the S system is maintained at the hydraulic pressure.
  • the control system is switched from the P system to the S system, and the value detected by the hydraulic pressure sensor 93 is stored as the primary system hydraulic pressure Ppri.
  • the S system is selected as the control system, the S system is increased in pressure, and the P system is maintained in hydraulic pressure.
  • the leakage has occurred from the P system, since the leakage is relatively small, there is almost no decrease in the hydraulic pressure during the operation of maintaining the hydraulic pressure in the P system.
  • the control system is switched from the S system to the P system, and the value detected by the hydraulic pressure sensor 93 is stored as the secondary system hydraulic pressure Psec.
  • a differential pressure ⁇ P between the primary system hydraulic pressure Ppri and the secondary system hydraulic pressure Psec is calculated in S212.
  • of the differential pressure ⁇ P in S213 is equal to or greater than the predetermined abnormal differential pressure threshold P1 is No, the first liquid leakage detection process is continued.
  • both the P and S systems behave in such a way that the pressure can be increased and maintained.
  • FIG. 9 is a time chart showing the operation of the hydraulic pressure control unit 6 when only the second liquid leakage detection process is performed in the liquid leakage detection mode, and a relatively small amount of liquid leakage occurs in the P system.
  • the target wheel cylinder hydraulic pressure Pw * is 0 [MPa]
  • target wheel cylinder hydraulic pressure Pw * is generated, and hydraulic pressure control is started.
  • the shutoff valves 21P and 21S are closed, the communication valves 26P and 26S are opened, the motor 7a is ON, and the pressure regulating valve 27 is closed (proportional control).
  • the fluid pressure control can be performed without any problem because the leakage is relatively small.
  • the hydraulic pressures of the P system and the S system both reach the target wheel cylinder hydraulic pressure Pw *.
  • whether or not the wheel cylinder hydraulic pressure Pw has reached the target wheel cylinder hydraulic pressure Pw * is determined from the relationship between the target wheel cylinder hydraulic pressure Pw * and the hydraulic pressure of each system.
  • execution of the second liquid leakage detection process is started.
  • the P system is selected as the control system (determined by the control system switching process in S301).
  • the shutoff valves 21P and 21S, the pressure regulating valve 27, and the communication valve 26S are closed, the communication valve 26P is opened, and the motor 7a is OFF.
  • the P system forms a closed circuit, but the fluid pressure gradually decreases in the P system where a relatively small amount of liquid leakage occurs.
  • the control system is switched from the P system to the repressurization control, and the value detected by the hydraulic pressure sensor 93 is stored as the primary system hydraulic pressure Ppri in step S312.
  • the repressurization control is selected (determined by the control system switching process in S301).
  • the communication valve 26P is closed, the communication valve 26S is opened, the motor 7a is ON, and the pressure regulating valve 27 is closed according to step S306. (Proportional control), the target wheel cylinder hydraulic pressure Pw * is generated, the hydraulic pressure control is started, and the hydraulic pressure of the S system reaches the target foil cylinder hydraulic pressure Pw * by time T34.
  • the S system is selected as the control control (determined by the control system switching process in S302).
  • shutoff valves 21P and 21S, the communication valve 26P and the pressure regulating valve 27 are closed, the communication valve 26S is opened, and the motor 7a is OFF.
  • the S system forms a closed circuit, but the S system where no liquid leakage occurs maintains the hydraulic pressure.
  • the value detected by the hydraulic pressure sensor 93 at step T313 at time T35 is stored as the secondary system hydraulic pressure Psec.
  • of the differential pressure ⁇ P of the secondary system hydraulic pressure Psec reaches the abnormal differential pressure threshold P2, and the hydraulic pressure failure of the P system is detected.
  • the second liquid leakage detection process it is possible to detect a relatively small amount of liquid leakage by performing an operation of maintaining the hydraulic pressure by making the P system and the S system independent.
  • the control of the P system and the S system needs to be alternately performed for one cycle. Therefore, when the target wheel cylinder hydraulic pressure changes, ⁇ P in step S315 cannot be calculated correctly. For this reason, it is preferable to implement in a scene where the target wheel cylinder hydraulic pressure can be kept constant, such as when the vehicle is stopped.
  • the second liquid leak detection process is based on the premise that a predetermined liquid pressure is generated in both the P and S systems for liquid leak detection.
  • a predetermined liquid pressure is generated in both the P and S systems for liquid leak detection.
  • the conditions for detecting liquid leakage may not be satisfied.
  • the wheel cylinder 8 is held at a higher pressure, the outflow speed is increased, so that the detectability for a relatively small amount of liquid leakage is improved.
  • the holding hydraulic pressure is higher.
  • FIG. 10 is a time chart showing the operation of the hydraulic pressure control unit 6 in the liquid leakage detection mode of the first embodiment, and a relatively small amount of liquid leakage occurs in the P system.
  • the vehicle is traveling, a braking request is generated at time T40, the target wheel cylinder hydraulic pressure corresponding to the pedal stroke S is set, and the operation of the first liquid leakage detection process is started. Since the amount of liquid leakage is relatively small, the wheel cylinder hydraulic pressure Pw is generated in both the P and S systems according to the target wheel cylinder hydraulic pressure Pw *, and the vehicle decelerates.
  • the vehicle stops, and the target wheel cylinder hydraulic pressure Pw * is set to a predetermined hydraulic pressure Pws for detecting leakage at the time of stopping.
  • the operation of the second fluid leakage detection process is started.
  • the differential pressure between the P and S systems is calculated in the second liquid leakage detection process, and the differential pressure exceeds the abnormal differential pressure threshold P2, so the P system that is lower in pressure than the S system is determined as the liquid leakage system.
  • the hydraulic pressure control shifts to the S-system single-system boost mode, and the target wheel cylinder hydraulic pressure Pw * is also switched to the target wheel cylinder hydraulic pressure Pw * corresponding to the pedal stroke S.
  • the hydraulic pressure of the P system is reduced by opening the shutoff valve 21P on the P system side at the end of the driver's brake operation.
  • the ECU 100 causes the hydraulic pressure sensor 93 to operate in the first state in which the communication valve 26P is operated in the valve opening direction and the communication valve 26S is operated in the valve closing direction.
  • the detected hydraulic pressure is acquired and detected by the hydraulic pressure sensor 93 in the second state in which the communication valve 26P is operated in the valve closing direction and the communication valve 26S is operated in the valve opening direction after the first state. Get the hydraulic pressure.
  • the P system first liquid paths 11B, 11a, and 11d are in communication with the discharge liquid path 16 provided with the hydraulic pressure sensor 93, and the S system first liquid paths 11B, 11b, and 11c. Will be disconnected.
  • the ECU 100 can acquire the hydraulic pressure of the first liquid passages 11B, 11a, 11d of the P system, that is, the primary system hydraulic pressure Ppri from the hydraulic pressure sensor 93.
  • the first liquid passages 11B, 11b, 11c of the S system are in communication with the discharge liquid passage 16, and the communication of the first liquid passages 11B, 11a, 11d of the P system is blocked. It becomes a state.
  • the ECU 100 can acquire the hydraulic pressures of the S system first liquid passages 11B, 11b, and 11c from the hydraulic pressure sensor 93, that is, the secondary system hydraulic pressure Psec.
  • the brake control device 1 can acquire the primary system hydraulic pressure Ppri and the secondary system hydraulic pressure Psec using the existing hydraulic pressure sensor 93 provided between the pump 7 and the communication valves 26P and 26S. Therefore, both the hydraulic pressure sensor that detects the primary system hydraulic pressure Ppri and the hydraulic pressure sensor that detects the secondary system hydraulic pressure Psec are not required, so that an increase in size and cost can be suppressed.
  • the ECU 100 detects a brake fluid leakage in each system based on the primary system fluid pressure Ppri acquired in the first state and the secondary system fluid pressure Psec acquired in the second state. As a result, it is possible to detect the liquid leakage system using only the hydraulic pressure sensor 93.
  • the ECU 100 operates the communication valves 26P and 26S in the valve opening direction, and then operates the pump 7 to alternately repeat the first state and the second state.
  • a first fluid leak detection process for detecting a fluid leak in both the P and S systems is executed.
  • the wheel cylinder hydraulic pressure Pw of both systems is gradually increased, and the liquid leaks into the P system or S system.
  • the wheel cylinder hydraulic pressure Pw of the normal system is gradually increased, so that the liquid leakage system can be detected while generating the braking force.
  • the second liquid leak detection process In order to execute the second liquid leak detection process, it is necessary to increase the hydraulic pressures of both the P and S systems to a predetermined liquid pressure Pws for detecting a liquid leak when the vehicle is stopped, but before executing the second liquid leak detection process.
  • the first fluid leakage detection process By executing the first fluid leakage detection process at the same time, when the amount of brake fluid leakage is relatively small, it is ensured that the fluid pressure in both the P and S systems reaches the predetermined fluid pressure Pws for detecting fluid leakage during stoppage.
  • the pressure can be increased, and the liquid leakage system can be detected by the second liquid leakage detection process.
  • the fluid leakage system can be detected by the first fluid leakage detection process. That is, by executing the second liquid leak detection process after the first liquid leak detection process, the detection accuracy of the liquid leak system can be improved regardless of the amount of brake fluid leak.
  • the ECU 100 executes the second liquid leak detection process when the generation of the predetermined liquid pressure Pws can be confirmed in both the P and S systems after the execution of the first liquid leak detection process. Since the second liquid leak detection process is based on the premise that the hydraulic pressure is generated in both the P and S systems, the second liquid leak detection process is performed only when the conditions for performing the liquid leak detection by the second liquid leak detection process are satisfied. By executing the leak detection process, it is possible to suppress unnecessary execution of the second liquid leak detection process.
  • the ECU 100 executes the first liquid leak detection process while the vehicle is stopped. In the first liquid leakage detection process, the P system and the S system are alternately switched to repeat the pressure increase and the fluid pressure maintenance.
  • the vehicle behavior (reduction by the driver) is not intended. Speed change).
  • the vehicle behavior not intended by the driver does not occur.
  • the ECU 100 executes the second liquid leak detection process while the vehicle is stopped. During the second liquid leak detection process, the communication valves 26P and 26S are alternately closed, and the motor 7a is inactivated during the control other than the repressurization control, so the change in the target wheel cylinder hydraulic pressure Pw * I cannot follow.
  • the ECU 100 sets a period from the start of the first state (start of the first liquid leak detection process) to the end of the second state (trip of the second liquid leak detection process) during the first liquid leak detection process.
  • start of the first liquid leak detection process start of the first liquid leak detection process
  • second state trip of the second liquid leak detection process
  • FIG. 11 is a flowchart showing the flow of processing in the liquid leakage detection mode of the second embodiment.
  • the fail safe unit 103 of the ECU 100 includes a first liquid leak detection execution state determination unit 113 as a configuration for executing the liquid leak detection mode.
  • the first liquid leakage detection execution state determination unit 113 measures the number of control cycles of the P system and the S system in the first liquid leakage detection process.
  • step S118 the first liquid leakage detection execution state determination unit 113 determines whether the number of control cycles of the P system and the S system is greater than or equal to a predetermined value in the first liquid leakage detection process. If YES, the process proceeds to step S113, and if NO, this process ends.
  • the ECU 100 performs a predetermined number of times of switching between control of the P system (first state) and control of the S system (second state) in the first liquid leakage detection process. Then, the second liquid leakage detection process is executed. That is, the fact that the liquid leakage system cannot be detected even if the first liquid leakage detection process takes a certain amount of time means that the amount of leakage of the brake fluid is relatively small. Therefore, in this case, by shifting from the first liquid leak detection process to the second liquid leak detection process, it is possible to suppress an unnecessary increase in the detection time of the liquid leak system.
  • the fluid pressure source is composed of only the pump 7, it may be combined with a pressure accumulator such as an accumulator.
  • the hydraulic pressure control unit may be an integrated type in which the master cylinder 3, the hydraulic pressure control unit 6, and the stroke simulator 5 are integrated, or any one of them may be configured by a plurality of divided units. .
  • the condition for making a transition to the operation for detecting a faulty system may be a condition in which a liquid leak failure is suspected. For example, it is possible to shift to an operation for detecting a faulty system on condition that the deviation between the target wheel cylinder hydraulic pressure and the actual wheel cylinder hydraulic pressure is equal to or greater than a predetermined value.
  • step S115 in FIG. 3 it is determined whether the control of the P system and the S system has been completed for one cycle. In order to improve the detection accuracy of the liquid leakage system, the control of the P system and the S system is performed in a predetermined cycle. It is good also as determination of whether it is complete
  • Detection of the faulty system in the first liquid leakage detection process is not limited to that shown in S212 to S214 of FIG.
  • the target wheel cylinder hydraulic pressure Pw * and the differential pressure of each system may be monitored.
  • the faulty system may be determined when a state in which the absolute value
  • the integrated value of the differential pressure ⁇ P exceeds a predetermined value, the failed system may be determined, or various methods for evaluating the differential pressure ⁇ P can be applied.
  • Detection of the faulty system in the second liquid leakage detection process is not limited to that shown in S315 to S317 of FIG.
  • the target wheel cylinder hydraulic pressure Pws for detecting leakage at the time of stopping and the differential pressure of each system may be monitored. Further, the faulty system may be determined when the state in which the abnormal differential pressure threshold P2 is exceeded for a certain period of time. Further, when the integrated value of the differential pressure ⁇ P exceeds a predetermined value, the failed system may be determined, and various methods for evaluating the differential pressure ⁇ P can be applied.
  • the control system switching time may be longer when the vehicle is stopped than when the vehicle is traveling. As the switching time is increased during traveling, the amount of pressure increase or decrease in pressure increases. Therefore, a large differential pressure is generated between the P and S systems, which may affect vehicle behavior. On the other hand, even if a differential pressure is generated between the P and S systems while the vehicle is stopped, the vehicle behavior is not affected, and the liquid leakage system can be detected early.
  • the brake control device includes a first connection fluid path connected to a first braking force applying unit that applies braking force to the wheel according to the brake fluid pressure, and a wheel according to the brake fluid pressure.
  • a second connecting liquid path that connects to a second braking force applying section that applies a braking force, the first connecting liquid path, and a communicating liquid path that connects the second connecting liquid path;
  • a first communication valve provided in the communication liquid path; a second communication valve provided in the communication liquid path; and the first communication valve and the second communication valve among the communication liquid paths.
  • the pressure sensor and the first communication valve are operated in the valve opening direction and the second communication valve is operated in the valve closing direction.
  • a physical quantity related to the first pressure detected by the sensor is acquired, and after the first state, the first communication valve is operated in the valve closing direction, and the second communication valve is operated in the valve opening direction.
  • control unit is configured such that the first connection liquid path or the control unit is based on the acquired physical quantity related to the first pressure and the acquired physical quantity related to the second pressure. Brake fluid leakage in the second connection fluid path is detected.
  • control unit operates the hydraulic pressure source after operating the first communication valve and the second communication valve in a valve opening direction. A first liquid that detects the liquid leakage based on a physical quantity related to the first pressure and a physical quantity related to the second pressure when the first state and the second state are alternately repeated. Perform leak detection processing.
  • control unit operates the hydraulic pressure source after operating the first communication valve and the second communication valve in a valve opening direction. Based on the physical quantity related to the first pressure and the physical quantity related to the second pressure when the hydraulic pressure source is stopped to enter the first state and then to the second state, the liquid leakage A second liquid leakage detection process is performed to detect. In still another preferred aspect, in any one of the above aspects, the control unit executes the second liquid leak detection process after executing the first liquid leak detection process.
  • control unit has a predetermined hydraulic pressure in the first connection liquid path and the second connection liquid path after the execution of the first liquid leak detection process.
  • the second liquid leakage detection process is executed when the above has occurred.
  • control unit performs the switching between the first state and the second state a predetermined number of times in the first liquid leakage detection process, and then A two-liquid leak detection process is executed.
  • control unit executes the first liquid leak detection process and the second liquid leak detection process while the vehicle is stopped.
  • control unit has a cycle from the start of the first state to the end of the second state as one cycle. The liquid leak is detected. In still another preferred aspect, in any one of the above aspects, the control unit executes the second liquid leakage detection process while the vehicle is stopped.
  • the abnormality detection method for the brake control device includes a first connection fluid path connected to a first braking force application unit that applies a braking force to the wheel according to the brake fluid pressure.
  • a second connection liquid path connected to a second braking force applying unit that applies a braking force to the wheel according to the brake hydraulic pressure, the first connection liquid path, and the second connection liquid path, Of the communication liquid path, the first communication valve provided in the communication liquid path, the second communication valve provided in the communication liquid path, and the first communication among the communication liquid paths.
  • An abnormality detection method for a brake control device comprising: a pressure sensor provided in a fluid path between the first and second valves; A physical quantity relating to a first pressure detected by the pressure sensor in a first state in which the second communication valve is operated in the valve closing direction is acquired in the first state, and after the first state Obtaining a physical quantity related to the second pressure detected by the pressure sensor in a second state in which the first communication valve is operated in the valve closing direction and the second communication valve is operated in the valve opening direction. Based on the acquired physical quantity related to the first pressure and the acquired physical quantity related to the second pressure, the brake fluid leaks in the first connection liquid path or the second connection liquid path Is detected.
  • this invention is not limited to above-described embodiment, Various modifications are included.
  • the above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to one having all the configurations described.
  • a part of the configuration of an embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of an embodiment.
  • 1 brake control device 7 pump (hydraulic pressure source) 8a, 8d wheel cylinder (first braking force applying portion) 8b, 8c wheel cylinder (second braking force applying portion) 11P, 11a, 11d first fluid path (first 1 connection liquid path) 11S, 11b, 11c first liquid path (second connection liquid path) 16P discharge liquid path (communication liquid path) 16S discharge liquid path (communication liquid path) 26P communication valve (first communication valve) ) 26S communication valve (second communication valve) 93 Fluid pressure sensor (pressure sensor) 100 ECU (control unit) FL ⁇ RR wheel

Landscapes

  • Engineering & Computer Science (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Regulating Braking Force (AREA)
  • Valves And Accessory Devices For Braking Systems (AREA)

Abstract

In the present invention, an ECU actuates a connection valve in a valve opening direction so as to acquire a P-system brake fluid pressure that has been detected by a fluid pressure sensor in a state of P-system control in which the connection valve was actuated in a valve-closing direction, and actuates the connection valve in the valve-closing direction so as to acquire an S-system brake fluid pressure that has been detected by the brake fluid sensor in a state of S-system control in which the connection valve was actuated in the valve-opening direction.

Description

ブレーキ制御装置およびブレーキ制御装置の異常検出方法Brake control device and abnormality detection method for brake control device
　本発明は、ブレーキ制御装置およびブレーキ制御装置の異常検出方法に関する。 The present invention relates to a brake control device and an abnormality detection method for the brake control device.
　マスタシリンダおよびホイルシリンダ間を接続する２つのブレーキ系統が連通液路で接続され、連通液路に２つの連通弁が設けられ、両連通弁間にポンプの吐出側が接続されたブレーキ制御装置が、知られている。
  特許文献１には、ポンプを作動させて両連通弁を交互に開閉動作させたときの両ブレーキ液等の液圧に基づいて液漏れ系統を検知し、その後、両ブレーキ系統の液圧を所定の液圧まで高めてから両連通弁を閉じた後の両ブレーキ系統の液圧に基づいて液漏れ系統を検知する技術が開示されている。 A brake control device in which two brake systems connecting between the master cylinder and the wheel cylinder are connected by a communication fluid path, two communication valves are provided in the communication fluid path, and a discharge side of the pump is connected between the two communication valves, Are known.
In Patent Document 1, a fluid leakage system is detected based on the fluid pressures of both brake fluids when the pump is operated to alternately open and close both communication valves, and then the fluid pressures of both brake systems are predetermined. A technique for detecting a liquid leakage system based on the hydraulic pressures of both brake systems after closing both communicating valves after increasing the hydraulic pressure to the above-described level is disclosed.
特開2018-1973号公報JP 2018-1973
　しかしながら、上記特許文献１にあっては、両ブレーキ系統の液圧を検出するための液圧センサを搭載しているため、大型化や高コスト化を招くおそれがあった。 However, in the above-mentioned Patent Document 1, since the hydraulic pressure sensor for detecting the hydraulic pressure of both brake systems is installed, there is a risk of increasing the size and cost.
  本発明の目的の一つは、大型化および高コスト化を抑制できるブレーキ制御装置およびブレーキ制御装置の異常検出方法を提供することにある。
　本発明の一実施形態におけるブレーキ制御装置は、第１の連通弁を開弁方向に作動させ、第２の連通弁を閉弁方向に作動させた第１の状態で圧力センサによって検出された第１の圧力に関する物理量を取得し、第１の連通弁を閉弁方向に作動させ、第２の連通弁を開弁方向に作動させた第２の状態で圧力センサによって検出された第２の圧力に関する物理量を取得するコントロールユニットを備える。 One of the objects of the present invention is to provide a brake control device and an abnormality detection method for the brake control device that can suppress an increase in size and cost.
In one embodiment of the present invention, the brake control device detects the first communication valve detected by the pressure sensor in the first state in which the first communication valve is operated in the valve opening direction and the second communication valve is operated in the valve closing direction. The second pressure detected by the pressure sensor in the second state in which the physical quantity related to the pressure of 1 is acquired, the first communication valve is operated in the valve closing direction, and the second communication valve is operated in the valve opening direction. It has a control unit that acquires the physical quantity.
　よって、本発明の一実施形態におけるブレーキ制御装置によれば、大型化および高コスト化を抑制できる。 Therefore, according to the brake control device in one embodiment of the present invention, it is possible to suppress an increase in size and cost.
実施形態１のブレーキ制御装置1の概略構成図である。1 is a schematic configuration diagram of a brake control device 1 of Embodiment 1. FIG. 各制御状態の状態遷移を表すフローチャートである。It is a flowchart showing the state transition of each control state. 実施形態１の液漏れ検知モードにおける処理の流れを示すフローチャートである。3 is a flowchart illustrating a processing flow in a liquid leakage detection mode according to the first embodiment. 第１液漏れ検知処理の流れを示すフローチャートである。It is a flowchart which shows the flow of a 1st liquid leak detection process. 第１液漏れ検知部107における液圧フィードバック制御のブロック図である。FIG. 5 is a block diagram of hydraulic pressure feedback control in a first liquid leak detection unit 107. 第２液漏れ検知処理の流れを示すフローチャートである。It is a flowchart which shows the flow of a 2nd liquid leak detection process. P系統で比較的多量の液漏れが発生している場合に、液漏れ検知モードで第１液漏れ検知処理のみを実施した場合の液圧制御ユニット6の動作を示すタイムチャートである。6 is a time chart showing the operation of the hydraulic pressure control unit 6 when only the first liquid leakage detection process is performed in the liquid leakage detection mode when a relatively large amount of liquid leakage occurs in the P system. P系統で比較的少量の液漏れが発生している場合に、液漏れ検知モードで第１液漏れ検知処理のみを実施した場合の液圧制御ユニット6の動作を示すタイムチャートである。7 is a time chart showing the operation of the hydraulic pressure control unit 6 when only the first liquid leakage detection process is performed in the liquid leakage detection mode when a relatively small amount of liquid leakage occurs in the P system. P系統で比較的少量の液漏れが発生している場合に、液漏れ検知モードで第２液漏れ検知処理のみを実施した場合の液圧制御ユニット6の動作を示すタイムチャートである。7 is a time chart showing the operation of the hydraulic pressure control unit 6 when only the second liquid leakage detection process is performed in the liquid leakage detection mode when a relatively small amount of liquid leakage occurs in the P system. 実施形態１の液漏れ検知モードにおける液圧制御ユニット6の動作を示すタイムチャートである。6 is a time chart showing the operation of the hydraulic pressure control unit 6 in the liquid leakage detection mode of the first embodiment. 実施形態２の液漏れ検知モードにおける処理の流れを示すフローチャートである。6 is a flowchart illustrating a process flow in a liquid leakage detection mode according to the second embodiment.
　〔実施形態１〕
  図１は、実施形態１のブレーキ制御装置1の概略構成図である。ブレーキ制御装置1は、電動車両に好適な液圧式ブレーキ装置である。電動車両は、車輪を駆動する原動機として、エンジンのほかモータジェネレータを備えたハイブリッド車や、モータジェネレータのみを備えた電気自動車等である。なお、エンジンのみを駆動力源とする車両にブレーキ制御装置1を適用してもよい。ブレーキ制御装置1は、車両の各車輪FL～RR（左前輪FL、右前輪FR、左後輪RL、右後輪RR）に設けられたホイルシリンダ8にブレーキ液を供給してブレーキ液圧（ホイルシリンダ液圧Pw）を発生させる。このホイルシリンダ液圧Pwにより摩擦部材を移動させ、摩擦部材を車輪側の回転部材に押付けることで、摩擦力を発生させる。これにより、各車輪FL～RRに液圧制動力を付与する。ここで、ホイルシリンダ8は、ディスクブレーキ機構における油圧式ブレーキキャリパのシリンダのほか、ドラムブレーキ機構のホイルシリンダであってもよい。ブレーキ制御装置1は、２系統すなわちP（プライマリ）系統およびS（セカンダリ）系統のブレーキ系統（ブレーキ配管）を有しており、例えばX配管形式を採用している。なお、前後配管等、他の配管形式を採用してもよい。以下、P系統に対応して設けられた部材とS系統に対応する部材とを区別する場合は、それぞれの符号の末尾に添字P,Sを付す。 Embodiment 1
FIG. 1 is a schematic configuration diagram of a brake control device 1 according to the first embodiment. The brake control device 1 is a hydraulic brake device suitable for an electric vehicle. The electric vehicle is a hybrid vehicle provided with a motor generator in addition to an engine as a prime mover for driving wheels, an electric vehicle provided with only a motor generator, or the like. Note that the brake control device 1 may be applied to a vehicle using only the engine as a driving force source. The brake control device 1 supplies brake fluid to a wheel cylinder 8 provided on each wheel FL to RR (left front wheel FL, right front wheel FR, left rear wheel RL, right rear wheel RR) of the vehicle to provide brake fluid pressure ( Foil cylinder hydraulic pressure Pw) is generated. The friction member is moved by the wheel cylinder hydraulic pressure Pw, and the friction member is pressed against the rotating member on the wheel side to generate a frictional force. As a result, a hydraulic braking force is applied to each of the wheels FL to RR. Here, the wheel cylinder 8 may be a wheel cylinder of a drum brake mechanism in addition to a cylinder of a hydraulic brake caliper in the disc brake mechanism. The brake control device 1 has two systems, that is, a brake system (brake piping) of a P (primary) system and an S (secondary) system, and employs, for example, an X piping format. In addition, you may employ | adopt other piping formats, such as front and rear piping. In the following, when distinguishing between members provided corresponding to the P system and members corresponding to the S system, the suffixes P and S are added to the end of each symbol.
　ブレーキペダル2は、ドライバのブレーキ操作の入力を受けるブレーキ操作部材である。ブレーキペダル2はいわゆる吊下げ型であり、その基端が軸201によって回転自在に支持されている。ブレーキペダル2の先端には、ドライバが踏み込む対象となるパッド202が設けられている。ブレーキペダル2の軸201とパッド202との間における基端側には、プッシュロッド2aの一端が、軸203によって回転自在に接続されている。
  マスタシリンダ3は、ドライバによるブレーキペダル2の操作（ブレーキ操作）により作動し、ブレーキ液圧（マスタシリンダ液圧Pm）を発生する。なお、ブレーキ制御装置1は、車両のエンジンが発生する吸気負圧を利用してブレーキ操作力（ブレーキペダル2の踏力F）を倍力または増幅する負圧式の倍力装置を備えていない。このため、ブレーキ制御装置1を小型化可能であり、かつ、負圧源（多くの場合はエンジン）を有さない電動車両に最適である。マスタシリンダ3は、プッシュロッド2aを介してブレーキペダル2に接続されると共に、リザーバタンク4からブレーキ液を補給される。リザーバタンク4は、ブレーキ液を貯留するブレーキ液源であり、大気圧に開放される低圧部である。リザーバタンク4の内部における底部側（鉛直方向下側）は、所定の高さを有する複数の仕切部材により、プライマリ液圧室用空間41Pと、セカンダリ液圧室用空間41Sと、ポンプ吸入用空間42とに区画（画成）されている。リザーバタンク内には、リザーバタンク内ブレーキ液量のレベルを検出する液面センサ94が設置されている。液面センサ94は、リザーバタンク4内の液面低下を警報するために用いられ、固定部材とフロート部材からなり、液面レベルを離散的に検出する。固定部材は、リザーバタンク4の内壁に固定されており、スイッチを有している。スイッチは、液面レベルと略同一の高さとなる位置に設けられている。フロート部材は、ブレーキ液に対して浮力を有しており、ブレーキ液量（液面レベル）の増減に応じて固定部材に対して上下に移動するように設けられている。リザーバタンク4内のブレーキ液量が減少し、フロート部材が所定液面レベルまで低下するように移動すると、固定部材に設けられたスイッチがオフ状態からオン状態に切り替る。これにより、液面レベルの低下を検出する。なお、液面センサ94の具体的な態様は上記のように液面レベルを離散的に検出するもの（スイッチ）に限定されず、液面レベルを連続的に検出するもの（アナログ検出）であってもよい。 The brake pedal 2 is a brake operation member that receives an input of a driver's brake operation. The brake pedal 2 is a so-called suspension type, and its base end is rotatably supported by a shaft 201. At the tip of the brake pedal 2, a pad 202 that is a target to be depressed by the driver is provided. One end of the push rod 2a is rotatably connected to the base end side between the shaft 201 and the pad 202 of the brake pedal 2 by the shaft 203.
The master cylinder 3 is actuated by operation of the brake pedal 2 (brake operation) by the driver, and generates brake fluid pressure (master cylinder fluid pressure Pm). The brake control device 1 does not include a negative pressure type booster that boosts or amplifies the brake operation force (stepping force F of the brake pedal 2) using intake negative pressure generated by the vehicle engine. For this reason, the brake control device 1 can be miniaturized and is optimal for an electric vehicle that does not have a negative pressure source (in many cases, an engine). The master cylinder 3 is connected to the brake pedal 2 via the push rod 2a, and is supplied with brake fluid from the reservoir tank 4. The reservoir tank 4 is a brake fluid source that stores brake fluid, and is a low pressure portion that is opened to atmospheric pressure. The bottom side (vertically in the vertical direction) inside the reservoir tank 4 includes a primary hydraulic pressure chamber space 41P, a secondary hydraulic pressure chamber space 41S, and a pump suction space by a plurality of partition members having a predetermined height. It is divided into 42 (defined). A liquid level sensor 94 that detects the level of the brake fluid amount in the reservoir tank is installed in the reservoir tank. The liquid level sensor 94 is used to warn of a decrease in the liquid level in the reservoir tank 4, and includes a fixed member and a float member, and discretely detects the liquid level. The fixing member is fixed to the inner wall of the reservoir tank 4 and has a switch. The switch is provided at a position that is substantially the same height as the liquid level. The float member has buoyancy with respect to the brake fluid, and is provided so as to move up and down with respect to the fixed member in accordance with an increase or decrease in the amount of brake fluid (liquid level). When the amount of brake fluid in the reservoir tank 4 decreases and the float member moves so as to decrease to a predetermined fluid level, the switch provided on the fixed member switches from the off state to the on state. Thereby, a drop in the liquid level is detected. The specific mode of the liquid level sensor 94 is not limited to the one that discretely detects the liquid level (switch) as described above, but is one that continuously detects the liquid level (analog detection). May be.
　マスタシリンダ3は、タンデム型であり、ブレーキ操作に応じて軸方向に移動するマスタシリンダピストンとして、プライマリピストン32Pとセカンダリピストン32Sとを直列に備えている。プライマリピストン32Pはプッシュロッド2aに接続されている。セカンダリピストン32Sはフリーピストン型である。
  ブレーキペダル2には、ストロークセンサ90が設けられている。ストロークセンサ90はブレーキペダル2の変位量（ペダルストロークS）を検出する。なお、ストロークセンサ90をプッシュロッド2aやプライマリピストン32Pに設けてピストンストロークSpを検出してもよい。このとき、ペダルストロークSは、プッシュロッド2aまたはプライマリピストン32Pの軸方向変位量（ストローク量）にブレーキペダルのペダル比Kを乗じたものに相当する。Kは、プライマリピストン32Pのストローク量に対するSの比率であり、所定の値に設定されている。Kは、例えば、軸201から軸203までの距離に対する、軸201からパッド202までの距離の比により算出できる。
  ストロークシミュレータ5は、ドライバのブレーキ操作に応じて作動する。ストロークシミュレータ5は、ドライバのブレーキ操作に応じてマスタシリンダ3の内部から流出したブレーキ液がストロークシミュレータ5内に流入することで、ペダルストロークSを発生させる。マスタシリンダ3から供給されたブレーキ液によりストロークシミュレータ5のピストン52がシリンダ50内を軸方向に作動する。これにより、ストロークシミュレータ5はドライバのブレーキ操作に伴う操作反力を生成する。 The master cylinder 3 is a tandem type and includes a primary piston 32P and a secondary piston 32S in series as a master cylinder piston that moves in the axial direction in response to a brake operation. The primary piston 32P is connected to the push rod 2a. The secondary piston 32S is a free piston type.
The brake pedal 2 is provided with a stroke sensor 90. The stroke sensor 90 detects the amount of displacement of the brake pedal 2 (pedal stroke S). The stroke sensor 90 may be provided on the push rod 2a or the primary piston 32P to detect the piston stroke Sp. At this time, the pedal stroke S corresponds to a value obtained by multiplying the axial displacement (stroke amount) of the push rod 2a or the primary piston 32P by the pedal ratio K of the brake pedal. K is a ratio of S to the stroke amount of the primary piston 32P, and is set to a predetermined value. K can be calculated, for example, by the ratio of the distance from the axis 201 to the pad 202 with respect to the distance from the axis 201 to the axis 203.
The stroke simulator 5 operates according to the driver's brake operation. The stroke simulator 5 generates the pedal stroke S when the brake fluid that has flowed out from the inside of the master cylinder 3 flows into the stroke simulator 5 in accordance with the brake operation of the driver. The brake fluid supplied from the master cylinder 3 operates the piston 52 of the stroke simulator 5 in the cylinder 50 in the axial direction. Thereby, the stroke simulator 5 generates an operation reaction force accompanying the brake operation of the driver.
　液圧制御ユニット6は、ドライバによるブレーキ操作とは独立にブレーキ液圧を発生可能な制動制御ユニットである。電子制御ユニット（コントロールユニットであり、以下、ECUという。）100は、液圧制御ユニット6の作動を制御するコントロールユニットである。液圧制御ユニット6は、リザーバタンク4またはマスタシリンダ3からブレーキ液の供給を受ける。液圧制御ユニット6は、ホイルシリンダ8とマスタシリンダ3との間に設けられており、各ホイルシリンダ8にマスタシリンダ液圧Pmまたは制御液圧を個別に供給可能である。液圧制御ユニット6は、制御液圧を発生するための液圧機器として、ポンプ（液圧源）7のモータ7aおよび複数の制御弁（電磁弁26等）を有している。ポンプ7は、マスタシリンダ3以外のブレーキ液源（リザーバタンク4等）からブレーキ液を吸入し、ホイルシリンダ8に向けて吐出する。ポンプ7は例えばプランジャポンプやギヤポンプである。ポンプ7は両系統で共通に用いられ、同一の駆動源としての電動式のモータ7aにより回転駆動される。モータ7aとして、例えばブラシ付き直流モータやブラシレスモータ等である。電磁弁26等は、制御信号に応じて開閉動作し、液路11等の連通状態を切り替える。これにより、ブレーキ液の流れを制御する。液圧制御ユニット6は、マスタシリンダ3とホイルシリンダ8との連通を遮断した状態で、ポンプ7が発生する液圧によりホイルシリンダ8を加圧可能である。また、液圧制御ユニット6は、Pmとポンプ7の吐出圧を検出する液圧センサ91,93を備えている。 The hydraulic pressure control unit 6 is a braking control unit that can generate the brake hydraulic pressure independently of the brake operation by the driver. An electronic control unit (a control unit, hereinafter referred to as an ECU) 100 is a control unit that controls the operation of the hydraulic pressure control unit 6. The hydraulic pressure control unit 6 receives supply of brake fluid from the reservoir tank 4 or the master cylinder 3. The hydraulic pressure control unit 6 is provided between the wheel cylinder 8 and the master cylinder 3, and can supply the master cylinder hydraulic pressure Pm or the control hydraulic pressure to each wheel cylinder 8 individually. The hydraulic control unit 6 has a motor 7a of a pump (hydraulic pressure source) 7 and a plurality of control valves (electromagnetic valve 26 and the like) as hydraulic equipment for generating a control hydraulic pressure. The pump 7 draws in brake fluid from a brake fluid source other than the master cylinder 3 (reservoir tank 4 or the like) and discharges it toward the wheel cylinder 8. The pump 7 is, for example, a plunger pump or a gear pump. The pump 7 is used in common in both systems and is rotationally driven by an electric motor 7a as the same drive source. Examples of the motor 7a include a brushed DC motor and a brushless motor. The electromagnetic valve 26 or the like opens and closes according to the control signal, and switches the communication state of the liquid path 11 and the like. Thereby, the flow of brake fluid is controlled. The hydraulic pressure control unit 6 can pressurize the wheel cylinder 8 with the hydraulic pressure generated by the pump 7 in a state where the communication between the master cylinder 3 and the wheel cylinder 8 is cut off. The hydraulic pressure control unit 6 includes hydraulic pressure sensors 91 and 93 that detect the discharge pressure of Pm and the pump 7.
　ECU100には、ストロークセンサ90、および液圧センサ91,93から送られる検出値、並びに車両側から送られる走行状態に関する情報が入力される。ECU100は、これら各種情報に基づき、内蔵されたプログラムに従って情報処理を行う。また、この処理結果に従って液圧制御ユニット6の各アクチュエータに指令信号を出力し、これらを制御する。具体的には、電磁弁26等の開閉動作や、モータ7aの回転数（すなわちポンプ7の吐出量）を制御する。これにより各車輪FL～RRのホイルシリンダ液圧Pwを制御することで、各種ブレーキ制御を実現する。例えば、倍力制御、アンチロック制御、車両運動制御のためのブレーキ制御、自動ブレーキ制御、回生協調ブレーキ制御等を実現する。倍力制御は、ドライバのブレーキ操作力では不足する液圧制動力を発生してブレーキ操作を補助する。アンチロック制御は、制動による車輪FL～RRのスリップ（ロック傾向）を抑制する。車両運動制御は、横滑り等を防止する車両挙動安定化制御(ESC)である。自動ブレーキ制御は、先行車追従制御等である。回生協調ブレーキ制御は、回生ブレーキと協調して目標減速度（目標制動力）を達成するようにホイルシリンダ液圧Pwを制御する。 The ECU 100 receives the detection values sent from the stroke sensor 90 and the hydraulic pressure sensors 91 and 93, and information related to the running state sent from the vehicle side. The ECU 100 performs information processing according to a built-in program based on these various types of information. In addition, command signals are output to the actuators of the hydraulic pressure control unit 6 according to the processing results to control them. Specifically, the opening / closing operation of the electromagnetic valve 26 and the like, and the rotation speed of the motor 7a (that is, the discharge amount of the pump 7) are controlled. Thus, various brake controls are realized by controlling the wheel cylinder hydraulic pressure Pw of each wheel FL to RR. For example, boost control, anti-lock control, brake control for vehicle motion control, automatic brake control, regenerative cooperative brake control, and the like are realized. The boost control assists the brake operation by generating a hydraulic braking force that is insufficient for the driver's brake operation force. Anti-lock control suppresses slipping (lock tendency) of the wheels FL to RR due to braking. Vehicle motion control is vehicle behavior stabilization control (ESC) that prevents skidding and the like. The automatic brake control is a preceding vehicle following control or the like. The regenerative cooperative brake control controls the wheel cylinder hydraulic pressure Pw so as to achieve the target deceleration (target braking force) in cooperation with the regenerative brake.
　マスタシリンダ3の両ピストン32P,32Sの間にプライマリ液圧室31Pが画成されている。プライマリ液圧室31Pには、コイルスプリング33Pが押し縮められた状態で設置されている。ピストン32Sとシリンダ30のｘ軸正方向端部との間にセカンダリ液圧室31Sが画成されている。セカンダリ液圧室31Sには、コイルスプリング33Sが押し縮められた状態で設置されている。各液圧室31P,31Sには第１液路11が開口する。各液圧室31P,31Sは、第１液路11を介して、液圧制御ユニット6に接続すると共に、ホイルシリンダ8と連通可能に設けられている。
  ドライバによるブレーキペダル2の踏み込み操作によってピストン32がストロークし、液圧室31の容積の減少に応じて液圧Pmが発生する。両液圧室31P,31Sには略同じPmが発生する。これにより、液圧室31から第１液路11を介してホイルシリンダ8に向けてブレーキ液が供給される。マスタシリンダ3は、プライマリ液圧室31Pに発生したPmによりP系統の液路（第１液路11P）を介してP系統のホイルシリンダ（第１の制動力付与部）8a,8dを加圧可能である。また、マスタシリンダ3は、セカンダリ液圧室31Sに発生したPmによりS系統の液路（第１液路11S）を介してS系統のホイルシリンダ（第２の制動力付与部）8b,8cを加圧可能である。 A primary hydraulic chamber 31P is defined between both pistons 32P and 32S of the master cylinder 3. In the primary hydraulic pressure chamber 31P, the coil spring 33P is installed in a compressed state. A secondary hydraulic pressure chamber 31S is defined between the piston 32S and the positive end of the cylinder 30 in the x-axis direction. In the secondary hydraulic chamber 31S, the coil spring 33S is installed in a compressed state. A first liquid passage 11 is opened in each of the hydraulic chambers 31P and 31S. The hydraulic chambers 31P and 31S are connected to the hydraulic pressure control unit 6 through the first liquid passage 11 and are provided so as to communicate with the wheel cylinder 8.
The piston 32 is stroked by the depression of the brake pedal 2 by the driver, and the hydraulic pressure Pm is generated as the volume of the hydraulic pressure chamber 31 decreases. Approximately the same Pm is generated in both hydraulic pressure chambers 31P and 31S. As a result, the brake fluid is supplied from the hydraulic chamber 31 to the wheel cylinder 8 through the first fluid path 11. The master cylinder 3 pressurizes the P system wheel cylinders (first braking force applying portions) 8a and 8d through the P system fluid passage (first fluid passage 11P) by Pm generated in the primary fluid pressure chamber 31P. Is possible. Further, the master cylinder 3 causes the wheel cylinders (second braking force applying portions) 8b and 8c of the S system to pass through the S system fluid path (first fluid path 11S) by Pm generated in the secondary hydraulic pressure chamber 31S. Pressurization is possible.
　次に、ストロークシミュレータ5の構成を図１に基づき説明する。ストロークシミュレータ5は、シリンダ50とピストン52とスプリング53を有している。図１では、ストロークシミュレータ5のシリンダ50の軸心を通る断面を示す。シリンダ50は筒状であり、円筒状の内周面を有している。シリンダ50は、ｘ軸負方向側に比較的小径のピストン収容部501を有し、ｘ軸正方向側に比較的大径のスプリング収容部502を有している。スプリング収容部502の内周面には後述する第３液路13（13A）が常時開口する。ピストン52は、ピストン収容部501の内周側に、その内周面に沿ってｘ軸方向に移動可能に設置されている。ピストン52は、シリンダ50内を少なくとも２室（正圧室511と背圧室512）に分離する分離部材（隔壁）である。シリンダ50内において、ピストン52のｘ軸負方向側に正圧室511が画成され、ｘ軸正方向側に背圧室512が画成されている。正圧室511は、ピストン52のｘ軸負方向側の面とシリンダ50（ピストン収容部501）の内周面とにより囲まれる空間である。第２液路12は、正圧室511に常時開口する。背圧室512は、ピストン52のｘ軸正方向側の面とシリンダ50（スプリング収容部502、ピストン収容部501）の内周面により囲まれる空間である。液路13Aは、背圧室512に常時開口する。 Next, the configuration of the stroke simulator 5 will be described with reference to FIG. The stroke simulator 5 includes a cylinder 50, a piston 52, and a spring 53. FIG. 1 shows a cross section passing through the axis of the cylinder 50 of the stroke simulator 5. The cylinder 50 is cylindrical and has a cylindrical inner peripheral surface. The cylinder 50 has a relatively small-diameter piston accommodating portion 501 on the x-axis negative direction side and a relatively large-diameter spring accommodating portion 502 on the x-axis positive direction side. A third liquid passage 13 (13A), which will be described later, always opens on the inner peripheral surface of the spring accommodating portion 502. The piston 52 is installed on the inner peripheral side of the piston accommodating portion 501 so as to be movable in the x-axis direction along the inner peripheral surface thereof. The piston 52 is a separation member (partition wall) that separates the inside of the cylinder 50 into at least two chambers (a positive pressure chamber 511 and a back pressure chamber 512). In the cylinder 50, a positive pressure chamber 511 is defined on the x-axis negative direction side of the piston 52, and a back pressure chamber 512 is defined on the x-axis positive direction side. The positive pressure chamber 511 is a space surrounded by the surface of the piston 52 on the x-axis negative direction side and the inner peripheral surface of the cylinder 50 (piston accommodating portion 501). The second liquid path 12 always opens to the positive pressure chamber 511. The back pressure chamber 512 is a space surrounded by the surface on the x-axis positive direction side of the piston 52 and the inner peripheral surface of the cylinder 50 (spring accommodating portion 502, piston accommodating portion 501). The liquid passage 13A always opens into the back pressure chamber 512.
　ピストン52の外周には、ピストン52の軸心の周り方向（周方向）に延びるようにピストンシール54が設置されている。ピストンシール54は、シリンダ50（ピストン収容部501）の内周面に摺接して、ピストン収容部501の内周面とピストン52の外周面との間をシールする。ピストンシール54は、正圧室511と背圧室512との間をシールすることでこれらを液密に分離する分離シール部材であり、ピストン52の上記分離部材としての機能を補完する。スプリング53は、背圧室512内に押し縮められた状態で設置されたコイルスプリングであり、ピストン52をｘ軸負方向側に常時付勢する。スプリング53は、ｘ軸方向に変形可能に設けられており、ピストン52の変位量（ストローク量）に応じて反力を発生可能である。スプリング53は、第１スプリング531と第２スプリング532を有している。第１スプリング531は、第２スプリング532よりも小径かつ短尺であり、線径が小さい。第１スプリング531のばね定数は第２スプリング532よりも小さい。第１，第２スプリング531,532は、ピストン52とシリンダ50（スプリング収容部502）との間に、リテーナ部材530を介して直列に配置されている。 A piston seal 54 is installed on the outer periphery of the piston 52 so as to extend in the direction around the axis of the piston 52 (circumferential direction). The piston seal 54 is in sliding contact with the inner peripheral surface of the cylinder 50 (piston accommodating portion 501), and seals between the inner peripheral surface of the piston accommodating portion 501 and the outer peripheral surface of the piston 52. The piston seal 54 is a separation seal member that seals between the positive pressure chamber 511 and the back pressure chamber 512 to separate them liquid-tightly, and complements the function of the piston 52 as the separation member. The spring 53 is a coil spring installed in a compressed state in the back pressure chamber 512, and always urges the piston 52 to the x axis negative direction side. The spring 53 is provided so as to be deformable in the x-axis direction, and can generate a reaction force according to the displacement amount (stroke amount) of the piston 52. The spring 53 has a first spring 531 and a second spring 532. The first spring 531 is smaller in diameter and shorter than the second spring 532, and has a smaller wire diameter. The spring constant of the first spring 531 is smaller than that of the second spring 532. The first and second springs 531 and 532 are arranged in series via the retainer member 530 between the piston 52 and the cylinder 50 (spring accommodating portion 502).
　次に、液圧制御ユニット6の液圧回路を図１に基づき説明する。各車輪FL～RRに対応する部材には、その符号の末尾にそれぞれ添字a～dを付して適宜区別する。第１液路11は、マスタシリンダ3の液圧室31とホイルシリンダ8とを接続する。遮断弁21は、第１液路11に設けられた常開型の（非通電状態で開弁する）電磁弁である。第１液路11は、遮断弁21によって、マスタシリンダ3側の液路11Aとホイルシリンダ8側の液路11Bとに分離される。ソレノイドイン弁(SOL/V IN)25は、第１液路11における遮断弁21よりもホイルシリンダ8側（液路11B）に、各車輪FL～RRに対応して（液路11a～11dに）設けられた常開型の電磁弁である。第１液路11P,11a,11dは第１の接続液路、第１液路11S,11b,11cは第２の接続液路である。なお、SOL/V IN25をバイパスして第１液路11と並列にバイパス液路120が設けられている。バイパス液路120には、ホイルシリンダ8側からマスタシリンダ3側へのブレーキ液の流れのみを許容するチェック弁（一方向弁または逆止弁）250が設けられている。
  吸入液路15は、リザーバタンク4（ポンプ吸入用空間42）とポンプ7の吸入部70とを接続する液路である。吐出液路16は、ポンプ7の吐出部71と、第１液路11Bにおける遮断弁21とSOL/V IN25との間とを接続する。チェック弁160は、吐出液路16に設けられ、ポンプ7の吐出部71の側（上流側）から第１液路11の側（下流側）へのブレーキ液の流れのみを許容する。チェック弁160は、ポンプ7が備える吐出弁である。吐出液路16は、チェック弁160の下流側でP系統の液路16PとS系統の液路16Sとに分岐している。各液路16P,16SはそれぞれP系統の第１液路11PとS系統の第１液路11Sに接続している。液路16P,16Sは、第１液路11P,11Sを互いに接続する連通液路として機能する。連通弁（第１の連通弁）26Pは、液路16Pに設けられた常閉型の（非通電状態で閉弁する）電磁弁である。連通弁（第２の連通弁）26Sは、液路16Sに設けられた常閉型の電磁弁である。ポンプ7は、リザーバタンク4から供給されるブレーキ液により第１液路11に液圧を発生させてホイルシリンダ液圧Pwを発生可能な第２の液圧源である。ポンプ7は、上記連通液路（吐出液路16P,16S）および第１液路11P,11Sを介してホイルシリンダ8a～8dと接続しており、連通液路（吐出液路16P,16S）にブレーキ液を吐出することでホイルシリンダ8を加圧可能である。 Next, the hydraulic circuit of the hydraulic control unit 6 will be described with reference to FIG. The members corresponding to the wheels FL to RR are appropriately distinguished by adding suffixes a to d at the end of the reference numerals. The first fluid path 11 connects the fluid pressure chamber 31 of the master cylinder 3 and the wheel cylinder 8. The shut-off valve 21 is a normally open type solenoid valve (opened in a non-energized state) provided in the first liquid passage 11. The first liquid path 11 is separated by a shutoff valve 21 into a liquid path 11A on the master cylinder 3 side and a liquid path 11B on the wheel cylinder 8 side. The solenoid-in valve (SOL / V IN) 25 is located closer to the wheel cylinder 8 (liquid path 11B) than the shut-off valve 21 in the first liquid path 11 and corresponds to each wheel FL to RR (to the liquid paths 11a to 11d). ) This is a normally open solenoid valve. The first liquid passages 11P, 11a, and 11d are first connection liquid passages, and the first liquid passages 11S, 11b, and 11c are second connection liquid passages. A bypass liquid path 120 is provided in parallel with the first liquid path 11 by bypassing the SOL / V IN 25. The bypass fluid path 120 is provided with a check valve (one-way valve or check valve) 250 that allows only the flow of brake fluid from the wheel cylinder 8 side to the master cylinder 3 side.
The suction liquid path 15 is a liquid path that connects the reservoir tank 4 (pump suction space 42) and the suction part 70 of the pump 7. The discharge liquid path 16 connects the discharge section 71 of the pump 7 and the shut-off valve 21 and the SOL / V IN 25 in the first liquid path 11B. The check valve 160 is provided in the discharge liquid passage 16 and allows only the flow of brake fluid from the discharge portion 71 side (upstream side) of the pump 7 to the first liquid passage 11 side (downstream side). The check valve 160 is a discharge valve provided in the pump 7. The discharge liquid path 16 branches into a P-system liquid path 16P and an S-system liquid path 16S on the downstream side of the check valve 160. The liquid passages 16P and 16S are connected to the first liquid passage 11P of the P system and the first liquid passage 11S of the S system, respectively. The liquid paths 16P and 16S function as communication liquid paths that connect the first liquid paths 11P and 11S to each other. The communication valve (first communication valve) 26P is a normally closed electromagnetic valve (closed in a non-energized state) provided in the liquid passage 16P. The communication valve (second communication valve) 26S is a normally closed electromagnetic valve provided in the liquid path 16S. The pump 7 is a second hydraulic pressure source capable of generating the wheel cylinder hydraulic pressure Pw by generating the hydraulic pressure in the first liquid passage 11 by the brake fluid supplied from the reservoir tank 4. The pump 7 is connected to the wheel cylinders 8a to 8d via the communication liquid path (discharge liquid paths 16P, 16S) and the first liquid paths 11P, 11S, and is connected to the communication liquid paths (discharge liquid paths 16P, 16S). The wheel cylinder 8 can be pressurized by discharging the brake fluid.
　第１減圧液路17は、吐出液路16におけるチェック弁160と連通弁26との間と、吸入液路15とを接続する。調圧弁27は、第１減圧液路17に設けられた第１減圧弁としての常開型の電磁弁である。なお、調圧弁27は常閉型でもよい。第２減圧液路18は、第１液路11BにおけるSOL/V IN25よりもホイルシリンダ8側と、吸入液路15とを接続する。ソレノイドアウト弁(SOL/V OUT)28は、第２減圧液路18に設けられた第２減圧弁としての常閉型の電磁弁である。なお、本実施形態では、調圧弁27よりも吸入液路15の側の第１減圧液路17と、SOL/V OUT28よりも吸入液路15の側の第２減圧液路18とが、部分的に共通している。
  第２液路12は、第１液路11Bから分岐してストロークシミュレータ5に接続する分岐液路である。第２液路12は、第１液路11Bと共に、マスタシリンダ3のセカンダリ液圧室31Sとストロークシミュレータ5の正圧室511とを接続する正圧側液路として機能する。なお、第２液路12が、第１液路11Aを介さずにセカンダリ液圧室31Sと正圧室511とを直接的に接続するようにしてもよい。第３液路13は、ストロークシミュレータ5の背圧室512と第１液路11とを接続する第１の背圧側液路である。具体的には、第３液路13は、第１液路11S（液路11B）における遮断弁21SとSOL/V IN25との間から分岐して背圧室512に接続する。ストロークシミュレータイン弁SS/V IN23は、第３液路13に設けられた常閉型の電磁弁である。第３液路13は、SS/V IN23によって、背圧室512側の液路13Aと第１液路11側の液路13Bとに分離される。SS/V IN23をバイパスして第３液路13と並列にバイパス液路130が設けられている。バイパス液路130は、液路13Aと液路13Bとを接続する。バイパス液路130にはチェック弁230が設けられている。チェック弁230は、背圧室512側（液路13A）から第１液路11側（液路13B）へ向うブレーキ液の流れを許容し、逆方向へのブレーキ液の流れを抑制する。 The first depressurizing liquid path 17 connects the suction liquid path 15 between the check valve 160 and the communication valve 26 in the discharge liquid path 16. The pressure regulating valve 27 is a normally open type electromagnetic valve as a first pressure reducing valve provided in the first pressure reducing liquid passage 17. The pressure regulating valve 27 may be a normally closed type. The second depressurization liquid path 18 connects the suction liquid path 15 to the wheel cylinder 8 side with respect to the SOL / V IN 25 in the first liquid path 11B. The solenoid-out valve (SOL / V OUT) 28 is a normally closed electromagnetic valve as a second pressure reducing valve provided in the second pressure reducing liquid path 18. In the present embodiment, the first depressurizing liquid path 17 on the suction liquid path 15 side from the pressure regulating valve 27 and the second depressurizing liquid path 18 on the suction liquid path 15 side from the SOL / V OUT 28 are partially provided. In common.
The second liquid path 12 is a branched liquid path that branches from the first liquid path 11B and connects to the stroke simulator 5. The second liquid path 12 functions as a positive pressure side liquid path that connects the secondary hydraulic pressure chamber 31S of the master cylinder 3 and the positive pressure chamber 511 of the stroke simulator 5 together with the first liquid path 11B. Note that the second fluid passage 12 may directly connect the secondary fluid pressure chamber 31S and the positive pressure chamber 511 without passing through the first fluid passage 11A. The third liquid path 13 is a first back pressure side liquid path that connects the back pressure chamber 512 of the stroke simulator 5 and the first liquid path 11. Specifically, the third liquid path 13 branches from between the shutoff valve 21S and the SOL / V IN 25 in the first liquid path 11S (liquid path 11B) and is connected to the back pressure chamber 512. The stroke simulator in valve SS / V IN23 is a normally closed electromagnetic valve provided in the third liquid passage 13. The third liquid path 13 is separated into a liquid path 13A on the back pressure chamber 512 side and a liquid path 13B on the first liquid path 11 side by SS / V IN23. A bypass liquid path 130 is provided in parallel with the third liquid path 13 by bypassing the SS / V IN 23. The bypass liquid path 130 connects the liquid path 13A and the liquid path 13B. A check valve 230 is provided in the bypass liquid passage 130. The check valve 230 allows the brake fluid to flow from the back pressure chamber 512 side (fluid passage 13A) toward the first fluid passage 11 side (fluid passage 13B) and suppresses the flow of brake fluid in the reverse direction.
　第４液路14は、ストロークシミュレータ5の背圧室512とリザーバタンク4とを接続する第２の背圧側液路である。第４液路14は、第３液路13における背圧室512とSS/V IN23との間（液路13A）と、吸入液路15（または、調圧弁27よりも吸入液路15側の第１減圧液路17や、SOL/V OUT28よりも吸入液路15側の第２減圧液路18）とを接続する。なお、第４液路14を背圧室512やリザーバタンク4に直接的に接続してもよい。ストロークシミュレータアウト弁（シミュレータカット弁）SS/V OUT24は、第４液路14に設けられた常閉型の電磁弁である。SS/V OUT24をバイパスして、第４液路14と並列にバイパス液路140が設けられている。バイパス液路140には、リザーバタンク4（吸入液路15）側から第３液路13A側すなわち背圧室512側へ向うブレーキ液の流れを許容し、逆方向へのブレーキ液の流れを抑制するチェック弁240が設けられている。
  遮断弁21、SOL/V IN25、および調圧弁27は、ソレノイドに供給される電流に応じて弁の開度が調整される比例制御弁である。他の弁、すなわちSS/V IN23、SS/V OUT24、連通弁26、およびSOL/V OUT28は、弁の開閉が二値的に切り替え制御される２位置弁（オン・オフ弁）である。なお、上記他の弁に比例制御弁を用いることも可能である。第１液路11Sにおける遮断弁21Sとマスタシリンダ3との間（液路11A）には、この箇所の液圧（マスタシリンダ液圧Pmおよびストロークシミュレータ5の正圧室511内の液圧）を検出する液圧センサ91が設けられている。吐出液路16におけるポンプ7の吐出部71（チェック弁160）と連通弁26との間には、この箇所の液圧（ポンプ吐出圧）を検出する液圧センサ（圧力センサ）93が設けられている。 The fourth liquid path 14 is a second back pressure side liquid path that connects the back pressure chamber 512 of the stroke simulator 5 and the reservoir tank 4. The fourth liquid path 14 is located between the back pressure chamber 512 and the SS / V IN 23 (liquid path 13A) in the third liquid path 13 and on the suction liquid path 15 side of the suction liquid path 15 (or the pressure regulating valve 27). The first depressurizing liquid path 17 and the second depressurizing liquid path 18) closer to the suction liquid path 15 than the SOL / V OUT28 are connected. The fourth liquid passage 14 may be directly connected to the back pressure chamber 512 or the reservoir tank 4. The stroke simulator out valve (simulator cut valve) SS / V OUT24 is a normally closed solenoid valve provided in the fourth liquid passage 14. Bypassing the SS / V OUT 24, a bypass liquid path 140 is provided in parallel with the fourth liquid path. The bypass fluid path 140 permits the flow of brake fluid from the reservoir tank 4 (suction fluid path 15) side to the third fluid path 13A side, that is, the back pressure chamber 512 side, and suppresses the brake fluid flow in the reverse direction. A check valve 240 is provided.
The shut-off valve 21, the SOL / V IN 25, and the pressure regulating valve 27 are proportional control valves in which the valve opening is adjusted according to the current supplied to the solenoid. The other valves, that is, SS / V IN23, SS / V OUT24, communication valve 26, and SOL / V OUT28 are two-position valves (on / off valves) in which the opening / closing of the valves is controlled by binary switching. It is also possible to use a proportional control valve as the other valve. Between the shutoff valve 21S and the master cylinder 3 in the first fluid passage 11S (fluid passage 11A), the fluid pressure at this location (the fluid pressure in the master cylinder fluid pressure Pm and the positive pressure chamber 511 of the stroke simulator 5) is set. A hydraulic pressure sensor 91 for detection is provided. Between the discharge part 71 (check valve 160) of the pump 7 and the communication valve 26 in the discharge liquid path 16, a hydraulic pressure sensor (pressure sensor) 93 for detecting the hydraulic pressure (pump discharge pressure) at this point is provided. ing.
　遮断弁21が開弁方向に制御された状態で、マスタシリンダ3の液圧室31とホイルシリンダ8とを接続するブレーキ系統（第１液路11）は、第１の系統を構成する。この第１の系統は、踏力Fを用いて発生させたマスタシリンダ液圧Pmによりホイルシリンダ液圧Pwを発生させることで、踏力ブレーキ（非倍力制御）を実現可能である。一方、遮断弁21が閉弁方向に制御された状態で、ポンプ7を含み、リザーバタンク4とホイルシリンダ8を接続するブレーキ系統（吸入液路15、吐出液路16等）は、第２の系統を構成する。この第２の系統は、ポンプ7を用いて発生させた液圧によりホイルシリンダ液圧Pwを発生させる、いわゆるブレーキバイワイヤ装置を構成し、ブレーキバイワイヤ制御として倍力制御等を実現可能である。ブレーキバイワイヤ制御（以下、単にバイワイヤ制御という。）時、ストロークシミュレータ5は、ドライバのブレーキ操作に伴う操作反力を生成する。
  ECU100は、バイワイヤ制御部101、踏力ブレーキ部102およびフェールセーフ部103を備えている。バイワイヤ制御部101は、ドライバのブレーキ操作状態に応じて、遮断弁21を閉じ、ポンプ7によりホイルシリンダ8を加圧する。バイワイヤ制御部101は、ブレーキ操作状態検出部104と、目標ホイルシリンダ液圧演算部105と、ホイルシリンダ液圧制御部106とを備えている。 A brake system (first fluid path 11) that connects the hydraulic chamber 31 of the master cylinder 3 and the wheel cylinder 8 in a state where the shutoff valve 21 is controlled in the valve opening direction constitutes a first system. This first system can realize pedal force braking (non-boosting control) by generating the wheel cylinder hydraulic pressure Pw by the master cylinder hydraulic pressure Pm generated using the pedal effort F. On the other hand, the brake system (suction fluid path 15, discharge fluid path 16, etc.) including the pump 7 and connecting the reservoir tank 4 and the wheel cylinder 8 with the shut-off valve 21 controlled in the valve closing direction is the second Configure the system. This second system constitutes a so-called brake-by-wire device that generates the wheel cylinder hydraulic pressure Pw by the hydraulic pressure generated using the pump 7, and can realize boost control or the like as brake-by-wire control. During brake-by-wire control (hereinafter simply referred to as “by-wire control”), the stroke simulator 5 generates an operation reaction force accompanying a driver's brake operation.
The ECU 100 includes a by-wire control unit 101, a pedal force brake unit 102, and a fail safe unit 103. The by-wire control unit 101 closes the shut-off valve 21 and pressurizes the wheel cylinder 8 by the pump 7 according to the brake operation state of the driver. The by-wire control unit 101 includes a brake operation state detection unit 104, a target wheel cylinder hydraulic pressure calculation unit 105, and a wheel cylinder hydraulic pressure control unit.
　ブレーキ操作状態検出部104は、ストロークセンサ90が検出した値の入力を受けて、ドライバによるブレーキ操作量としてのペダルストロークSを検出する。また、Sに基づき、ドライバのブレーキ操作中であるか否か（ブレーキペダル2の操作の有無）を検出する。なお、踏力Fを検出する踏力センサを設け、その検出値に基づきブレーキ操作量を検出または推定してもよい。また、液圧センサ91の検出値に基づきブレーキ操作量を検出または推定してもよい。すなわち、制御に用いるブレーキ操作量として、Sに限らず、他の適当な変数を用いてもよい。
  目標ホイルシリンダ液圧演算部105は、目標ホイルシリンダ液圧Pw*を算出する。例えば、倍力制御時には、検出されたペダルストロークS（ブレーキ操作量）に基づき、所定の倍力比に応じてSとドライバの要求ブレーキ液圧（ドライバが要求する車両減速度）との間の理想の関係（ブレーキ特性）を実現する目標ホイルシリンダ液圧Pw*を算出する。例えば、通常サイズの負圧式倍力装置を備えたブレーキ装置において、負圧式倍力装置の作動時に実現されるペダルストロークSとホイルシリンダ液圧Pw（制動力）との間の所定の関係を、目標ホイルシリンダ液圧Pw*を算出するための上記理想の関係とする。 The brake operation state detection unit 104 receives the input of the value detected by the stroke sensor 90, and detects the pedal stroke S as a brake operation amount by the driver. Further, based on S, it is detected whether or not the driver is operating the brake (whether or not the brake pedal 2 is operated). A pedal force sensor for detecting the pedal force F may be provided, and the brake operation amount may be detected or estimated based on the detected value. Further, the brake operation amount may be detected or estimated based on the detection value of the hydraulic pressure sensor 91. That is, the brake operation amount used for the control is not limited to S, and other appropriate variables may be used.
The target wheel cylinder hydraulic pressure calculation unit 105 calculates the target wheel cylinder hydraulic pressure Pw *. For example, during boost control, based on the detected pedal stroke S (brake operation amount), between S and the driver's required brake hydraulic pressure (vehicle deceleration requested by the driver) according to a predetermined boost ratio Calculate the target wheel cylinder hydraulic pressure Pw * that realizes the ideal relationship (brake characteristics). For example, in a brake device equipped with a normal size negative pressure booster, a predetermined relationship between the pedal stroke S and the wheel cylinder hydraulic pressure Pw (braking force) realized when the negative pressure booster is operated, The above ideal relationship for calculating the target wheel cylinder hydraulic pressure Pw * is obtained.
　ホイルシリンダ液圧制御部106は、遮断弁21を閉弁方向に制御することで、液圧制御ユニット6の状態を、ポンプ7（第２の系統）によりホイルシリンダ液圧Pwを発生（加圧制御）可能な状態とする。この状態で、液圧制御ユニット6の各アクチュエータを制御して目標ホイルシリンダ液圧Pw*を実現する液圧制御（例えば倍力制御）を実行する。具体的には、遮断弁21を閉弁方向に制御し、連通弁26を開弁方向に制御し、調圧弁27を閉弁方向に制御すると共に、ポンプ7を作動させる。このように制御することで、リザーバタンク4側から所望のブレーキ液を吸入液路15、ポンプ7、吐出液路16、および第１液路11を経由してホイルシリンダ8に送ることが可能である。ポンプ7が吐出するブレーキ液は吐出液路16を介して第１液路11Bに流入する。このブレーキ液が各ホイルシリンダ8に流入することによって、各ホイルシリンダ8が加圧される。すなわち、ポンプ7により第１液路11Bに発生させた液圧を用いてホイルシリンダ8を加圧する。このとき、液圧センサ93の検出値が目標ホイルシリンダ液圧Pw*に近づくようにポンプ7の回転数や調圧弁27の開弁状態（開度等）をフィードバック制御することで、所望の制動力が得られる。すなわち、調圧弁27の開弁状態を制御し、吐出液路16または第１液路11から調圧弁27を介して吸入液路15へブレーキ液を適宜漏らすことで、ホイルシリンダ液圧Pwを調節できる。 The wheel cylinder hydraulic pressure control unit 106 generates the wheel cylinder hydraulic pressure Pw by the pump 7 (second system) by controlling the shut-off valve 21 in the valve closing direction. Control) possible state. In this state, hydraulic pressure control (for example, boost control) for controlling the actuators of the hydraulic pressure control unit 6 to achieve the target wheel cylinder hydraulic pressure Pw * is executed. Specifically, the shutoff valve 21 is controlled in the valve closing direction, the communication valve 26 is controlled in the valve opening direction, the pressure regulating valve 27 is controlled in the valve closing direction, and the pump 7 is operated. By controlling in this way, it is possible to send a desired brake fluid from the reservoir tank 4 side to the wheel cylinder 8 via the suction fluid passage 15, the pump 7, the discharge fluid passage 16, and the first fluid passage 11. is there. The brake fluid discharged from the pump 7 flows into the first liquid path 11B via the discharge liquid path 16. As the brake fluid flows into each wheel cylinder 8, each wheel cylinder 8 is pressurized. That is, the wheel cylinder 8 is pressurized using the hydraulic pressure generated in the first liquid passage 11B by the pump 7. At this time, feedback control is performed on the rotational speed of the pump 7 and the valve opening state (opening degree, etc.) of the pressure regulating valve 27 so that the detected value of the hydraulic pressure sensor 93 approaches the target wheel cylinder hydraulic pressure Pw *. Power is obtained. That is, the wheel cylinder hydraulic pressure Pw is adjusted by controlling the valve opening state of the pressure regulating valve 27 and appropriately leaking the brake fluid from the discharge fluid passage 16 or the first fluid passage 11 to the suction fluid passage 15 through the pressure regulating valve 27. it can.
　本実施形態では、基本的に、ポンプ7（モータ7a）の回転数ではなく調圧弁27の開弁状態を変化させることによりホイルシリンダ液圧Pwを制御する。このとき、遮断弁21を閉弁方向に制御し、マスタシリンダ3側とホイルシリンダ8側とを遮断することで、ドライバのブレーキ操作から独立してホイルシリンダ液圧Pwを制御することが容易となる。また、SS/V OUT24を開弁方向に制御する。これにより、ストロークシミュレータ5の背圧室512と吸入液路15（リザーバタンク4）側とが連通する。よって、ブレーキペダル2の踏み込み操作に伴いマスタシリンダ3からブレーキ液が吐出され、このブレーキ液がストロークシミュレータ5の正圧室511に流入すると、ピストン52が作動する。これにより、ペダルストロークSpが発生する。正圧室511に流入する液量と同等の液量のブレーキ液が背圧室512から流出する。このブレーキ液は第３液路13Aおよび第４液路14を介して吸入液路15（リザーバタンク4）側へ排出される。なお、第４液路14はブレーキ液が流入可能な低圧部に接続していればよく、必ずしもリザーバタンク4に接続している必要はない。また、ストロークシミュレータ5のスプリング53と背圧室512の液圧等がピストン52を押す力により、ブレーキペダル2に作用する操作反力（ペダル反力）が発生する。すなわち、ストロークシミュレータ5は、バイワイヤ制御時に、ブレーキペダル2の特性（Fに対するSの関係であるF-S特性）を生成する。 In this embodiment, basically, the wheel cylinder hydraulic pressure Pw is controlled by changing the valve opening state of the pressure regulating valve 27, not the rotational speed of the pump 7 (motor 7a). At this time, by controlling the shut-off valve 21 in the valve closing direction and shutting off the master cylinder 3 side and the wheel cylinder 8 side, the wheel cylinder hydraulic pressure Pw can be easily controlled independently of the driver's brake operation. Become. Also, control SS / V OUT24 in the valve opening direction. As a result, the back pressure chamber 512 of the stroke simulator 5 communicates with the suction liquid passage 15 (reservoir tank 4) side. Accordingly, when the brake pedal 2 is depressed, the brake fluid is discharged from the master cylinder 3, and when this brake fluid flows into the positive pressure chamber 511 of the stroke simulator 5, the piston 52 is activated. As a result, a pedal stroke Sp is generated. Brake fluid having the same amount as that flowing into the positive pressure chamber 511 flows out from the back pressure chamber 512. The brake fluid is discharged to the suction fluid passage 15 (reservoir tank 4) through the third fluid passage 13A and the fourth fluid passage 14. Note that the fourth fluid passage 14 need only be connected to a low-pressure portion through which brake fluid can flow, and need not necessarily be connected to the reservoir tank 4. Further, an operation reaction force (pedal reaction force) acting on the brake pedal 2 is generated by the force by which the hydraulic pressure of the spring 53 of the stroke simulator 5 and the back pressure chamber 512 pushes the piston 52. That is, the stroke simulator 5 generates a characteristic of the brake pedal 2 (FS characteristic that is a relation of S to F) during the by-wire control.
　踏力ブレーキ部102は、遮断弁21を開け、マスタシリンダ3によりホイルシリンダ8を加圧する。遮断弁21を開弁方向に制御することで、液圧制御ユニット6の状態を、マスタシリンダ液圧Pm（第１の系統）によりホイルシリンダ液圧Pwを発生可能な状態とし、踏力ブレーキを実現する。このとき、SS/V OUT24を閉弁方向に制御することで、ドライバのブレーキ操作に対してストロークシミュレータ5を非作動とする。これにより、マスタシリンダ3からブレーキ液が効率的にホイルシリンダ8に向けて供給される。したがって、ドライバが踏力Fにより発生させるホイルシリンダ液圧Pwの低下を抑制できる。具体的には、踏力ブレーキ部102は、液圧制御ユニット6における全アクチュエータを非作動状態とする。なお、SS/V IN23を開弁方向に制御してもよい。
  フェールセーフ部103は、ブレーキ制御装置1における異常（失陥または故障）の発生を検出する。例えば、ブレーキ操作状態検出部104からの信号や、各センサからの信号に基づき、液圧制御ユニット6におけるアクチュエータ（ポンプ7またはモータ7aや調圧弁27等）の失陥を検知する。または、ブレーキ制御装置1に電源を供給する車載電源（バッテリ）やECU100の異常を検知する。フェールセーフ部103は、バイワイヤ制御中に異常の発生を検出すると、異常の状態に応じて制御を切り替える。例えば、バイワイヤ制御による液圧制御が継続不可能であると判断された場合は、踏力ブレーキ部102を作動させ、バイワイヤ制御から踏力ブレーキへ切替える。具体的には、液圧制御ユニット6における全アクチュエータを非作動状態とし、踏力ブレーキへ移行させる。ここで、遮断弁21は常開弁であるため、電源失陥時には遮断弁21が開弁することで、踏力ブレーキを自動的に実現することが可能である。また、SS/V OUT24は常閉弁であるため、電源失陥時にはSS/V OUT24が閉弁することで、ストロークシミュレータ5が自動的に非作動とされる。さらに、連通弁26は常閉型であるため、電源失陥時に両系統のブレーキ液圧系を互いに独立とし、各系統で別々に踏力Fによるホイルシリンダ加圧が可能となる。
  また、フェールセーフ部103は、液面センサ94がリザーバタンクの液面低下を検出した場合は、２つのブレーキ系統のうち液漏れ失陥が発生しているブレーキ系統（液漏れ系統）を検知するための動作を行う。なお、ブレーキ系統の液漏れ箇所は、液圧制御ユニット6のハウジングとホイルシリンダ8とを接続するブレーキ配管等であるが、SOL/V OUT28の開固着などによってもブレーキ系統の液圧が低下する。よって、実施形態１では、SOL/V OUT28の開固着などによる液圧低下もブレーキ系統の液漏れとして扱うものとする。バイワイヤ制御部101は、フェールセーフ部103により液漏れ系統が検知された場合、液漏れ失陥が発生していないブレーキ系統（正常系統）のみでバイワイヤ制御を行う（これを片系統倍力制御と呼ぶ）。片系統倍力制御では、遮断弁21、調圧弁27およびポンプ7の動作は通常制御（通常のバイワイヤ制御）と同様であるが、液漏れ系統側の連通弁26を閉弁して液漏れ系統側の連通液路を遮断する。これにより、正常系統のホイルシリンダ液圧Pwを制御できる。 The pedal force brake unit 102 opens the shut-off valve 21 and pressurizes the wheel cylinder 8 by the master cylinder 3. By controlling the shut-off valve 21 in the valve opening direction, the hydraulic pressure control unit 6 is brought into a state in which the wheel cylinder hydraulic pressure Pw can be generated by the master cylinder hydraulic pressure Pm (first system), and a pedaling force brake is realized. To do. At this time, by controlling the SS / V OUT 24 in the valve closing direction, the stroke simulator 5 is deactivated in response to the driver's brake operation. As a result, the brake fluid is efficiently supplied from the master cylinder 3 toward the wheel cylinder 8. Therefore, it is possible to suppress a decrease in the wheel cylinder hydraulic pressure Pw that is generated by the pedaling force F by the driver. Specifically, the pedal effort brake unit 102 deactivates all the actuators in the hydraulic pressure control unit 6. SS / V IN 23 may be controlled in the valve opening direction.
The fail safe unit 103 detects the occurrence of an abnormality (failure or failure) in the brake control device 1. For example, a failure of an actuator (pump 7 or motor 7a, pressure regulating valve 27, etc.) in the hydraulic pressure control unit 6 is detected based on a signal from the brake operation state detection unit 104 or a signal from each sensor. Alternatively, an abnormality is detected in the in-vehicle power source (battery) that supplies power to the brake control device 1 or the ECU 100. When fail-safe unit 103 detects the occurrence of an abnormality during the by-wire control, it switches control according to the abnormal state. For example, when it is determined that the hydraulic pressure control by the by-wire control cannot be continued, the pedal force brake unit 102 is operated to switch from the by-wire control to the pedal force brake. Specifically, all the actuators in the hydraulic pressure control unit 6 are deactivated and shifted to the pedal effort brake. Here, since the shut-off valve 21 is a normally open valve, it is possible to automatically realize pedal force braking by opening the shut-off valve 21 when the power supply fails. Since SS / V OUT24 is a normally closed valve, the stroke simulator 5 is automatically deactivated by closing SS / V OUT24 when the power fails. Further, since the communication valve 26 is a normally closed type, the brake fluid pressure systems of both systems are made independent of each other when the power fails, and the wheel cylinder can be pressurized by the pedaling force F in each system separately.
Further, when the liquid level sensor 94 detects a decrease in the liquid level of the reservoir tank, the fail safe unit 103 detects a brake system (liquid leakage system) in which a liquid leakage failure has occurred among the two brake systems. For the operation. Note that the leak point of the brake system is the brake piping that connects the housing of the hydraulic control unit 6 and the wheel cylinder 8, but the hydraulic pressure of the brake system also decreases due to the open fixing of the SOL / V OUT28. . Therefore, in the first embodiment, the hydraulic pressure drop due to the open fixing of the SOL / V OUT28 is also treated as a brake system liquid leak. When the liquid leakage system is detected by the fail safe unit 103, the by-wire control unit 101 performs the by-wire control only with the brake system (normal system) in which no liquid leakage has occurred (this is referred to as one-system boost control). Call). In single-system boost control, the operation of the shut-off valve 21, the pressure regulating valve 27, and the pump 7 is the same as in normal control (normal by-wire control), but the communication valve 26 on the liquid leakage system side is closed to close the liquid leakage system. Shut off the side communication fluid path. Thereby, the wheel cylinder hydraulic pressure Pw of the normal system can be controlled.
　図２は、各制御状態の状態遷移を表すフローチャートである。この処理は、ECU100内にプログラムとして実装され、所定の周期毎に実行される。
  ステップS1では、フェールセーフ部103において、液面センサ94からの信号に基づき、リザーバタンク4内に貯蔵されているブレーキ液に液面低下が生じているかを判定する。YESの場合はステップS3へ進み、NOの場合はステップS2へ進む。
  ステップS2では、バイワイヤ制御部101において、通常制御モードを実行する。通常制御モードは、バイワイヤ制御部101により通常のバイワイヤ制御を行うモードである。
  ステップS3では、フェールセーフ部103において、液漏れ系統が検知済みかを判定する。YESの場合はステップS5へ進み、NOの場合はステップS4へ進む。
  ステップS4では、フェールセーフ部103において、液漏れ検知モードを実行する。液漏れ検知モードは、液漏れ系統の検知を行うモードである。液漏れ検知モードの詳細は後述する。
  ステップS5では、フェールセーフ部103において、液漏れ系統がP系統かを判定する。YESの場合はステップS6へ進み、NOの場合はステップS7へ進む。
  ステップS6では、バイワイヤ制御部101において、S系統の片系統倍力モードを実行する。S系統の片系統倍力モードは、バイワイヤ制御部101によりS系統のみでバイワイヤ制御を行うモードである。P系統の液漏れ失陥を検知した場合は、正常なS系統で片系統倍力制御を行う。 FIG. 2 is a flowchart showing the state transition of each control state. This process is implemented as a program in the ECU 100 and executed at predetermined intervals.
In step S1, the fail safe unit 103 determines whether or not the brake level stored in the reservoir tank 4 is lowered based on the signal from the level sensor 94. If YES, the process proceeds to step S3. If NO, the process proceeds to step S2.
In step S2, the by-wire control unit 101 executes the normal control mode. The normal control mode is a mode in which normal by-wire control is performed by the by-wire control unit 101.
In step S3, the fail safe unit 103 determines whether the liquid leakage system has been detected. If YES, the process proceeds to step S5. If NO, the process proceeds to step S4.
In step S4, the fail safe unit 103 executes the liquid leak detection mode. The liquid leakage detection mode is a mode for detecting a liquid leakage system. Details of the liquid leakage detection mode will be described later.
In step S5, the fail safe unit 103 determines whether the liquid leakage system is the P system. If YES, the process proceeds to step S6. If NO, the process proceeds to step S7.
In step S6, the by-wire control unit 101 executes the S-system single-system boost mode. The single system boost mode of the S system is a mode in which the by-wire control unit 101 performs the by-wire control only in the S system. When the leakage of the P system is detected, one-system boost control is performed using the normal S system.
　ステップS7では、フェールセーフ部103において、液漏れ系統がS系統かを判定する。YESの場合はステップS8へ進み、NOの場合はステップS9へ進む。
  ステップS8では、バイワイヤ制御部101において、P系統の片系統倍力モードを実行する。P系統の片系統倍力モードは、バイワイヤ制御部101によりP系統のみでバイワイヤ制御を行うモードである。S系統の液漏れ失陥を検知した場合は、正常なP系統で片系統倍力制御を行う。
  ステップS9では、バイワイヤ制御部101において、P,S両系統の倍力制御を継続する。例えば、ホイルシリンダ8に液漏れは発生していないが、ブレーキパッドが摩耗し、ホイルシリンダ8の消費液量が摩耗前よりも増加したにもかかわらず長時間ブレーキ液の補充がなされない場合には、リザーバタンク4の液面は低下する。また、第１液路11の遮断弁21よりもマスタシリンダ側（液路11A）で液漏れが発生した場合にもリザーバタンク4の液面は低下する。これらの場合は倍力制御を継続可能であるが、使用可能なブレーキ液量は減少しているため、車両を安定的に減速させる必要最低限の倍力制御に留め、車両運動制御のためのブレーキ制御や自動ブレーキ制御等は禁止し、ドライバにメンテナンスを促すのが好ましい。 In step S7, the fail safe unit 103 determines whether the liquid leakage system is the S system. If YES, the process proceeds to step S8. If NO, the process proceeds to step S9.
In step S8, the by-wire control unit 101 executes the single system boost mode of the P system. The single system boost mode of the P system is a mode in which the by-wire control unit 101 performs the by-wire control only in the P system. If a liquid leakage failure is detected in the S system, the single system boost control is performed in the normal P system.
In step S9, the by-wire control unit 101 continues the boost control of both the P and S systems. For example, when there is no fluid leakage in the wheel cylinder 8, but the brake pads are worn out and the brake fluid is not replenished for a long time even though the amount of fluid consumed in the wheel cylinder 8 has increased from before the wear. As a result, the liquid level of the reservoir tank 4 decreases. Further, the liquid level of the reservoir tank 4 also decreases when a liquid leak occurs on the master cylinder side (liquid path 11A) with respect to the shutoff valve 21 of the first liquid path 11. In these cases, boost control can be continued, but the amount of brake fluid that can be used has decreased. It is preferable to prohibit brake control, automatic brake control, etc., and to prompt the driver for maintenance.
　図３は、実施形態１の液漏れ検知モードにおける処理の流れを示すフローチャートである。ECU100のフェールセーフ部103は、液漏れ検知モードを実行するための構成として、第１液漏れ検知部107、第２液漏れ検知部108、両系統液圧発生可否判断部109、車両走行停止状態判定部110、第２液漏れ検知実行状態判定部111および車両制動要求判定部112を有する。
  ステップS101では、車両走行停止状態判定部110において、車両が停車しているかを判定する。YESの場合はステップS106へ進み、NOの場合はステップS102へ進む。このステップでは、各車輪FL～RRに対応して車両に搭載された各車輪速度センサの信号を入力し、各車輪速度がいずれも0（ほぼ0も含む。）である場合に、車両が停止していると判定する。
  ステップS102では、車両制動要求判定部112において、制動要求が有るかを判定する。YESの場合はステップS103へ進み、NOの場合は本処理を終了する。このステップでは、ブレーキ操作状態検出部104または目標ホイルシリンダ液圧演算部105からの情報に基づき、車両に対する制動要求の有無を判定する。例えば、Sが0以外である場合にはドライバがブレーキペダル2を踏んでいるため、制動要求有りと判定する。
  ステップS103では、目標ホイルシリンダ液圧演算部105からの情報に基づき、目標ホイルシリンダ液圧Pw*を設定する。 FIG. 3 is a flowchart illustrating a processing flow in the liquid leakage detection mode of the first embodiment. The fail safe unit 103 of the ECU 100 includes a first liquid leak detection unit 107, a second liquid leak detection unit 108, a two-system hydraulic pressure generation possibility determination unit 109, and a vehicle travel stop state as a configuration for executing the liquid leak detection mode. It has a determination unit 110, a second liquid leak detection execution state determination unit 111, and a vehicle braking request determination unit 112.
In step S101, the vehicle travel stop state determination unit 110 determines whether the vehicle is stopped. If YES, the process proceeds to step S106, and if NO, the process proceeds to step S102. In this step, signals from each wheel speed sensor mounted on the vehicle corresponding to each wheel FL to RR are input, and the vehicle stops when each wheel speed is 0 (including almost 0). It is determined that
In step S102, the vehicle braking request determination unit 112 determines whether there is a braking request. If YES, the process proceeds to step S103, and if NO, this process ends. In this step, based on information from the brake operation state detection unit 104 or the target wheel cylinder hydraulic pressure calculation unit 105, it is determined whether there is a braking request for the vehicle. For example, when S is other than 0, it is determined that there is a braking request because the driver is stepping on the brake pedal 2.
In step S103, the target wheel cylinder hydraulic pressure Pw * is set based on the information from the target foil cylinder hydraulic pressure calculation unit 105.
　ステップS104では、第１液漏れ検知部107において、第１液漏れ検知処理を実行する。第１液漏れ検知処理の詳細は後述する。
  ステップS105では、フェールセーフ部103において、液漏れ系統が検知できたかを判定する。YESの場合はステップS109へ進み、NOの場合は本処理を終了する。
  ステップS106では、フェールセーフ部103において、目標ホイルシリンダ液圧Pw*を停車時液漏れ検知用の所定液圧Pwsに設定する。Pwsは、目標ホイルシリンダ液圧演算部105により演算された目標ホイルシリンダ液圧Pw*よりも高い液圧とする。これにより、液漏れが発生している場合の流出速度を速め、検知性を向上できる。
  ステップS107では、第１液漏れ検知部107において、第１液漏れ検知処理を実行する。
  ステップS108では、フェールセーフ部103において、液漏れ系統が検知できたかを判定する。YESの場合はステップS109へ進み、NOの場合はステップS111へ進む。
  ステップS109では、フェールセーフ部103において、液漏れ系統を記憶する。
  ステップS110では、フェールセーフ部103において、液漏れ系統を検知済みとして本処理を終了する。
  ステップS111では、両系統液圧発生可否判断部109において、P,S両系統に液圧が発生したかを確認する。液圧の発生は、液圧センサ93により検出された値が停車時液漏れ検知用の所定液圧Pwsとほぼ一致（差圧が小）していることで判断でき、差圧が小の時間が所定時間継続することなどを条件とすることが望ましい。 In step S104, the first liquid leak detection unit 107 executes a first liquid leak detection process. Details of the first liquid leakage detection process will be described later.
In step S105, the fail safe unit 103 determines whether a liquid leakage system has been detected. If YES, the process proceeds to step S109, and if NO, this process ends.
In step S106, in the fail safe unit 103, the target wheel cylinder hydraulic pressure Pw * is set to a predetermined hydraulic pressure Pws for detecting a leakage at the time of stopping. Pws is higher than the target wheel cylinder hydraulic pressure Pw * calculated by the target wheel cylinder hydraulic pressure calculation unit 105. Thereby, the outflow speed when the liquid leak has occurred can be increased, and the detectability can be improved.
In step S107, the first liquid leak detection unit 107 executes a first liquid leak detection process.
In step S108, the fail-safe unit 103 determines whether a liquid leakage system has been detected. If YES, the process proceeds to step S109, and if NO, the process proceeds to step S111.
In step S109, the fail safe unit 103 stores the liquid leakage system.
In step S110, the fail safe unit 103 determines that the liquid leakage system has been detected, and ends this process.
In step S111, both system hydraulic pressure generation possibility determination unit 109 confirms whether hydraulic pressure has been generated in both systems P and S. The occurrence of hydraulic pressure can be determined by the fact that the value detected by the hydraulic pressure sensor 93 is almost the same as the predetermined hydraulic pressure Pws for detecting leakage when the vehicle is stopped (the differential pressure is small). It is desirable that the condition be continued for a predetermined time.
　ステップS112では、フェールセーフ部103において、P,S両系統で液圧の発生が確認できたかを判定する。YESの場合はステップS113へ進み、NOの場合は本処理を終了する。
  ステップS113では、第２液漏れ検知部108において、第２液漏れ検知処理を実行する。第２液漏れ検知処理の詳細は後述する。
  ステップS114では、フェールセーフ部103において、液漏れ系統が検知できたかを判定する。YESの場合はステップS109へ進み、NOの場合はステップS115へ進む。
  ステップS115では、第２液漏れ検知実行状態判定部111において、第２液漏れ検知部108による第２液漏れ検知処理でP系統とS系統の制御が１サイクル終了しているかを判定する。YESの場合はステップS116へ進み、NOの場合は本処理を終了する。
  ステップS116では、フェールセーフ部103において、ホイルシリンダ8の液漏れ失陥以外の理由によるリザーバタンク4の液面低下と判定し、その情報を記憶する。第２液漏れ検知処理の実行時間が所定時間を超えた場合は、当該処理で検知しようとしているホイルシリンダ8の液漏れが生じていない場合であるため、液漏れ検知モードを終了する。 In step S112, the fail-safe unit 103 determines whether the generation of hydraulic pressure has been confirmed in both the P and S systems. If YES, the process proceeds to step S113, and if NO, this process ends.
In step S113, the second liquid leak detection unit 108 executes a second liquid leak detection process. Details of the second liquid leakage detection process will be described later.
In step S114, the failsafe unit 103 determines whether a liquid leakage system has been detected. If YES, the process proceeds to step S109, and if NO, the process proceeds to step S115.
In step S115, the second liquid leak detection execution state determination unit 111 determines whether the control of the P system and the S system has been completed in the second liquid leak detection process by the second liquid leak detection unit 108. If YES, the process proceeds to step S116, and if NO, this process ends.
In step S116, the fail safe unit 103 determines that the liquid level of the reservoir tank 4 has decreased due to reasons other than the fluid leakage failure of the wheel cylinder 8, and stores the information. When the execution time of the second liquid leakage detection process exceeds the predetermined time, the liquid leakage detection mode is terminated because the liquid leakage of the wheel cylinder 8 to be detected in the process has not occurred.
　図４は、第１液漏れ検知処理の流れを示すフローチャートである。
  ステップS201では、モータ7aを作動させ、遮断弁21P,21Sを閉弁する。
  ステップS202では、制御系統の切り替え処理を行う。制御系統の切り替えとは、P系統の制御とS系統の制御を選択的に切り替えるもので、実施形態１では、この切り替えを所定時間（例えば150ms）で行う。
  ステップS203では、現在の制御系統としてP系統が選択されているかを判定する。YESの場合はステップS204へ進み、NOの場合はステップS205へ進む。
  ステップS204では、連通弁26Pを開弁し、連通弁26Sを閉弁し、ホイルシリンダ液圧制御用のフィードバック液圧を液圧センサ93により検出された値にセットする。
  ステップS205では、連通弁26Pを閉弁し、連通弁26Sを開弁し、ホイルシリンダ液圧制御用のフィードバック液圧を液圧センサ93により検出された値にセットする。 FIG. 4 is a flowchart showing the flow of the first liquid leakage detection process.
In step S201, the motor 7a is operated and the shutoff valves 21P and 21S are closed.
In step S202, control system switching processing is performed. The switching of the control system is to selectively switch the control of the P system and the control of the S system. In the first embodiment, this switching is performed for a predetermined time (for example, 150 ms).
In step S203, it is determined whether the P system is selected as the current control system. If YES, the process proceeds to step S204. If NO, the process proceeds to step S205.
In step S204, the communication valve 26P is opened, the communication valve 26S is closed, and the feedback hydraulic pressure for wheel cylinder hydraulic pressure control is set to the value detected by the hydraulic pressure sensor 93.
In step S205, the communication valve 26P is closed, the communication valve 26S is opened, and the feedback hydraulic pressure for wheel cylinder hydraulic pressure control is set to the value detected by the hydraulic pressure sensor 93.
　ステップS206では、液圧フィードバック制御を実施し、ポンプ7の回転数および調圧弁27の開度の調整により、目標ホイルシリンダ液圧Pw*と制御系統のホイルシリンダ液圧Pwとが一致するようにサーボ制御する。図５は、第１液漏れ検知部107における液圧フィードバック制御のブロック図である。目標ホイルシリンダ液圧Pw*に対し、フィードバック液圧が一致するように構成される。フィードバック液圧は連通弁（26Pまたは26S）が開弁している系統の液圧である。連通弁が開弁している系統のみがポンプ7および調圧弁27によってホイルシリンダ液圧を調整可能だからである。調整できない系統は、遮断弁21と連通弁26とが共に閉弁しているため、閉回路が形成されホイルシリンダ液圧が保持される。第１液漏れ検知部107では、目標ホイルシリンダ液圧Pw*とフィードバック液圧との液圧偏差を液圧制御コントローラ107aに入力する。液圧制御コントローラ107aは、液圧偏差を無くすようにポンプ7の回転数および調圧弁27の電流（開度）を制御する。これにより、液圧制御ユニット6がホイルシリンダ液圧Pwを出力するように動作する。 In step S206, hydraulic pressure feedback control is performed so that the target wheel cylinder hydraulic pressure Pw * matches the wheel cylinder hydraulic pressure Pw of the control system by adjusting the rotation speed of the pump 7 and the opening of the pressure regulating valve 27. Servo control. FIG. 5 is a block diagram of the hydraulic pressure feedback control in the first liquid leak detection unit 107. The feedback hydraulic pressure is configured to match the target wheel cylinder hydraulic pressure Pw *. The feedback hydraulic pressure is the hydraulic pressure of the system in which the communication valve (26P or 26S) is open. This is because only the system in which the communication valve is open can adjust the wheel cylinder hydraulic pressure by the pump 7 and the pressure regulating valve 27. In the system that cannot be adjusted, the shut-off valve 21 and the communication valve 26 are both closed, so that a closed circuit is formed and the wheel cylinder hydraulic pressure is maintained. The first liquid leak detection unit 107 inputs a hydraulic pressure deviation between the target wheel cylinder hydraulic pressure Pw * and the feedback hydraulic pressure to the hydraulic pressure controller 107a. The hydraulic pressure controller 107a controls the rotational speed of the pump 7 and the current (opening degree) of the pressure regulating valve 27 so as to eliminate the hydraulic pressure deviation. Thereby, the hydraulic pressure control unit 6 operates so as to output the wheel cylinder hydraulic pressure Pw.
　ステップS207では、制御系統がP系統からS系統へ切り替えられた直後かを判定する。YESの場合はステップS209へ進み、NOの場合はステップS208へ進む。
  ステップS208では、制御系統がS系統からP系統へ切り替えられた直後かを判定する。YESの場合はステップS210へ進み、NOの場合はステップS211へ進む。
  ステップS209では、液圧センサ93により検出された値を、プライマリ系統液圧Ppriとして記憶する。
  ステップS210では、液圧センサ93により検出された値を、セカンダリ系統液圧Psecとして記憶する。
  ステップS211では、P系統およびS系統の制御が１サイクル終了したかを判定する。YESの場合はステップS212へ進み、NOの場合は本処理を終了する。
  ステップS212では、ステップS209とステップS210で記憶した各系統の液圧（プライマリ系統液圧Ppri、セカンダリ系統液圧Psec）の差圧ΔPを計算する。
  ステップS213では、差圧ΔPの絶対値|ΔP|が所定の異常差圧閾値P1以上であるかを判定する。YESの場合はステップS214へ進み、NOの場合は本処理を終了する。
  ステップS214では、P,S両系統のうち液圧が低い系統を失陥系統と確定する。 In step S207, it is determined whether the control system has just been switched from the P system to the S system. If YES, the process proceeds to step S209. If NO, the process proceeds to step S208.
In step S208, it is determined whether the control system has just been switched from the S system to the P system. If YES, the process proceeds to step S210. If NO, the process proceeds to step S211.
In step S209, the value detected by the hydraulic pressure sensor 93 is stored as the primary system hydraulic pressure Ppri.
In step S210, the value detected by the hydraulic pressure sensor 93 is stored as the secondary system hydraulic pressure Psec.
In step S211, it is determined whether the control of the P system and the S system has been completed for one cycle. If YES, the process proceeds to step S212, and if NO, this process ends.
In step S212, a differential pressure ΔP between the hydraulic pressures (primary system hydraulic pressure Ppri, secondary system hydraulic pressure Psec) stored in steps S209 and S210 is calculated.
In step S213, it is determined whether or not the absolute value | ΔP | of the differential pressure ΔP is equal to or greater than a predetermined abnormal differential pressure threshold P1. If YES, the process proceeds to step S214, and if NO, this process ends.
In step S214, a system with a low hydraulic pressure among both P and S systems is determined as a faulty system.
　図６は、第２液漏れ検知処理の流れを示すフローチャートである。
  ステップS301では、制御系統の切り替え処理を行う。制御系統の切り替えとは、P系統の制御、再増圧制御、S系統の制御を選択的に切り替えるもので、実施形態１では、この切り替えを所定時間（例えば1s）で行う。ここでの制御系統の切り替えでは、制御系統の切り替えの間に再増圧制御を実施しており、ステップS202とは異なる。また、制御系統の切り替え時間と再増圧制御の切り替え時間は別に設定してもよい。ただし、再増圧制御の切り替え時間については、制御系統切り替え時に目標ホイルシリンダ液圧付近から液漏れ判定を開始した方が、液漏れ系統が検知しやすいため、後述のステップS310の液圧フィードバック制御が完了する時間以上に設定することが望ましい。第２液漏れ検知処理においては、比較的少量の液漏れを検知するため、制御系統の切り替え時間については、図４に示した第１液漏れ検知処理におけるステップS202の制御系統の切り替え処理時の切り替え時間よりも長く設定することが望ましい。
  ステップS302では、現在の制御系統としてP系統が選択されているかを判定する。YESの場合はステップS303へ進み、NOの場合はステップS304へ進む。 FIG. 6 is a flowchart showing the flow of the second liquid leakage detection process.
In step S301, control system switching processing is performed. The switching of the control system is to selectively switch the control of the P system, the re-boosting control, and the control of the S system. In the first embodiment, this switching is performed for a predetermined time (for example, 1 s). In the switching of the control system here, re-boosting control is performed during the switching of the control system, which is different from step S202. Further, the switching time of the control system and the switching time of the re-boosting control may be set separately. However, with regard to the switching time of the re-pressurization control, it is easier to detect the liquid leakage system if the liquid leakage determination is started near the target wheel cylinder hydraulic pressure at the time of control system switching. It is desirable to set more than the time to complete. In the second liquid leakage detection process, since a relatively small amount of liquid leakage is detected, the control system switching time is the same as that in the control system switching process of step S202 in the first liquid leakage detection process shown in FIG. It is desirable to set it longer than the switching time.
In step S302, it is determined whether the P system is selected as the current control system. If YES, the process proceeds to step S303, and if NO, the process proceeds to step S304.
　ステップS303では、モータ7aを非作動とし、調圧弁27および遮断弁21P,21Sを閉弁し、連通弁26Pを開弁し、連通弁26Sを閉弁する。これにより、P系統の液路11B(11P),11a,11d、ホイルシリンダ8a,8dおよび液路16P,16Sが閉回路となり、液漏れが生じていない場合はP系統の液圧が保持可能となる。P系統の液漏れがあれば、P系統の液圧(液圧センサ93の値)は低下する。
  ステップS304では、現在の制御系統としてS系統が選択されているかを判定する。YESの場合はステップS305へ進み、NOの場合はステップS306へ進む。
  ステップS305では、モータ7aを非作動とし、調圧弁27および遮断弁21P,21Sを閉弁し、連通弁26Pを閉弁し、連通弁26Sを開弁する。これにより、S系統の液路11B(11S),11b,11c、ホイルシリンダ8b,8cおよび液路16P,16Sが閉回路となり、液漏れが生じていない場合はS系統の液圧が保持可能となる。液漏れがあれば、S系統の液圧(液圧センサ93の値)は低下する。
  ステップS306では、再増圧制御移行前の制御系統がP系統であったかを判定する。YESの場合はステップS307へ進み、NOの場合はステップS308へ進む。
  ステップS307では、モータ7aを作動させ、連通弁26Pを閉弁し、連通弁26Sを開弁し、ホイルシリンダ液圧制御用のフィードバック液圧を液圧センサ93により検出された値にセットする。 In step S303, the motor 7a is deactivated, the pressure regulating valve 27 and the shutoff valves 21P and 21S are closed, the communication valve 26P is opened, and the communication valve 26S is closed. As a result, the fluid paths 11B (11P), 11a, 11d of the P system, the wheel cylinders 8a, 8d and the fluid paths 16P, 16S are closed circuits, and the fluid pressure of the P system can be maintained when there is no liquid leakage. Become. If there is a fluid leak in the P system, the fluid pressure in the P system (the value of the fluid pressure sensor 93) decreases.
In step S304, it is determined whether the S system is selected as the current control system. If YES, the process proceeds to step S305, and if NO, the process proceeds to step S306.
In step S305, the motor 7a is deactivated, the pressure regulating valve 27 and the shutoff valves 21P and 21S are closed, the communication valve 26P is closed, and the communication valve 26S is opened. As a result, the S system fluid passages 11B (11S), 11b, 11c, the wheel cylinders 8b, 8c and the fluid passages 16P, 16S are closed circuits, and the fluid pressure of the S system can be maintained when there is no liquid leakage. Become. If there is a liquid leak, the hydraulic pressure of the S system (the value of the hydraulic pressure sensor 93) decreases.
In step S306, it is determined whether or not the control system before the transition to the repressurization control is the P system. If YES, the process proceeds to step S307, and if NO, the process proceeds to step S308.
In step S307, the motor 7a is operated, the communication valve 26P is closed, the communication valve 26S is opened, and the feedback hydraulic pressure for wheel cylinder hydraulic pressure control is set to the value detected by the hydraulic pressure sensor 93.
　ステップS308では、モータ7aを作動させ、連通弁26Pを開弁し、連通弁26Sを閉弁し、ホイルシリンダ液圧制御用のフィードバック液圧を液圧センサ93により検出された値にセットする。
  ステップS309では、ステップS206と同様の液圧フィードバック制御を実施する。
  ステップS310では、P系統制御終了直後かを判定する。YESの場合はステップS312へ進み、NOの場合はステップS311へ進む。
  ステップS311では、S系統制御終了直後かを判定する。YESの場合はステップS313へ進み、NOの場合はステップS314へ進む。
  ステップS312では、液圧センサ93により検出された値を、プライマリ系統液圧Ppriとして記憶する。
  ステップS313では、液圧センサ93により検出された値を、セカンダリ系統液圧Psecとして記憶する。
  ステップS314では、P系統およびS系統の制御が１サイクル終了したかを判定する。YESの場合はステップS315へ進み、NOの場合は本処理を終了する。
  ステップS315では、ステップS312とステップS313で記憶した各系統の液圧（プライマリ系統液圧Ppri、セカンダリ系統液圧Psec）の差圧ΔPを計算する。
  ステップS316では、差圧ΔPの絶対値|ΔP|が所定の異常差圧閾値P2以上であるかを判定する。YESの場合はステップS317へ進み、NOの場合は本処理を終了する。
  ステップS317では、P,S両系統のうち液圧が低い系統を失陥系統と確定する。 In step S308, the motor 7a is operated, the communication valve 26P is opened, the communication valve 26S is closed, and the feedback hydraulic pressure for wheel cylinder hydraulic pressure control is set to the value detected by the hydraulic pressure sensor 93.
In step S309, the same hydraulic pressure feedback control as in step S206 is performed.
In step S310, it is determined whether the P system control has just ended. If YES, the process proceeds to step S312. If NO, the process proceeds to step S311.
In step S311, it is determined whether the S system control has just ended. If YES, the process proceeds to step S313, and if NO, the process proceeds to step S314.
In step S312, the value detected by the hydraulic pressure sensor 93 is stored as the primary system hydraulic pressure Ppri.
In step S313, the value detected by the hydraulic pressure sensor 93 is stored as the secondary system hydraulic pressure Psec.
In step S314, it is determined whether the control of the P system and the S system has been completed for one cycle. If YES, the process proceeds to step S315, and if NO, this process ends.
In step S315, the differential pressure ΔP between the hydraulic pressures (primary system hydraulic pressure Ppri and secondary system hydraulic pressure Psec) of each system stored in steps S312 and S313 is calculated.
In step S316, it is determined whether the absolute value | ΔP | of the differential pressure ΔP is equal to or greater than a predetermined abnormal differential pressure threshold P2. If YES, the process proceeds to step S317, and if NO, this process ends.
In step S317, a system having a low hydraulic pressure among both the P and S systems is determined as a failed system.
　図７は、液漏れ検知モードで第１液漏れ検知処理のみを実施した場合の液圧制御ユニット6の動作を示すタイムチャートであり、P系統で比較的多量の液漏れ（液漏れ部の開口面積が大きい場合）が発生している。
  時刻T10以前は、目標ホイルシリンダ液圧Pw*が0[Mpa]であるため、非制御状態であり、遮断弁21P,21Sおよび調圧弁27は開弁状態、連通弁26P,26Sは閉弁状態、モータ7aはOFF（非作動）である。
  時刻T10では、目標ホイルシリンダ液圧Pw*が発生し、液圧制御が開始される。同時に遮断弁21P,21Sは閉弁状態、モータ7aはON（作動）、調圧弁27は閉弁状態（比例制御）となる。ここで、区間T10～T11では、制御系統としてP系統が選択されている（S202の制御系統の切り替え処理で決定）。区間T10～T11の間、P系統連通弁26Pは開弁し、S系統連通弁26Sは閉弁する。また、区間T10～T11の液圧フィードバック制御では、液圧センサ93により検出された値が目標ホイルシリンダ液圧Pw*に一致するようにサーボ制御が実施される。したがって、区間T10～T11では、P系統の液圧は上昇し、S系統は遮断弁21Sおよび連通弁26Sが共に閉弁されて閉回路が形成されるため、液圧は0のままである。ここで、液漏れが発生しているP系統の液圧が上昇するのは、ブレーキ液の流れによる損失によるものである。発生液圧の程度は、流体の性質上、流出部の開口面積の2乗に反比例し、液圧源（ポンプ7）からの流量の2乗に比例すると近似できるが、ポンプ7からのブレーキ液の供給流量には限りがあるため、多量の漏れが生じている場合には大きな液圧は発生できない。時刻T11で制御系統がP系統からS系統に切り替えられ、液圧センサ93により検出された値を、プライマリ系統液圧Ppriとして記憶する。 FIG. 7 is a time chart showing the operation of the hydraulic pressure control unit 6 when only the first liquid leakage detection process is performed in the liquid leakage detection mode, and a relatively large amount of liquid leakage (opening of the liquid leakage portion) is performed in the P system. Occurs when the area is large).
Before time T10, the target wheel cylinder hydraulic pressure Pw * is 0 [Mpa], so it is in an uncontrolled state, the shutoff valves 21P and 21S and the pressure regulating valve 27 are open, and the communication valves 26P and 26S are closed. The motor 7a is OFF (inactive).
At time T10, the target wheel cylinder hydraulic pressure Pw * is generated, and hydraulic pressure control is started. At the same time, the shutoff valves 21P and 21S are closed, the motor 7a is turned on (actuated), and the pressure regulating valve 27 is closed (proportional control). Here, in the sections T10 to T11, the P system is selected as the control system (determined by the control system switching process in S202). During the section T10 to T11, the P system communication valve 26P is opened and the S system communication valve 26S is closed. Further, in the hydraulic pressure feedback control in the sections T10 to T11, servo control is performed so that the value detected by the hydraulic pressure sensor 93 matches the target wheel cylinder hydraulic pressure Pw *. Accordingly, in the sections T10 to T11, the hydraulic pressure in the P system increases, and in the S system, the shutoff valve 21S and the communication valve 26S are both closed to form a closed circuit, so that the hydraulic pressure remains zero. Here, the increase in the hydraulic pressure of the P system in which the liquid leakage has occurred is due to a loss due to the flow of the brake fluid. The degree of generated hydraulic pressure is inversely proportional to the square of the opening area of the outflow part due to the nature of the fluid, and can be approximated to be proportional to the square of the flow rate from the hydraulic pressure source (pump 7). Since the supply flow rate is limited, a large hydraulic pressure cannot be generated when a large amount of leakage occurs. At time T11, the control system is switched from the P system to the S system, and the value detected by the hydraulic pressure sensor 93 is stored as the primary system hydraulic pressure Ppri.
　次に、区間T11～T12において、制御系統がS系統に切り替わる。区間T11～T12では、S系統連通弁26Sは開弁状態、P系統連通弁26Pは閉弁状態となる。また、区間T11～T12の液圧フィードバック制御では、液圧センサ93により検出された値が目標ホイルシリンダ液圧Pw*に一致するようにサーボ制御が実施される。したがって、区間T11～T12では、S系統の液圧は上昇し、P系統は遮断弁21Pおよび連通弁26Pが共に閉弁されて閉回路が形成されるため、液圧は保持されるはずである。ところが、P系統は液漏れが発生しているため、区間T11～T12ではブレーキ液が外部へ流出し、液圧が低下する。時刻T12で制御系統がS系統からP系統に切り替えられ、液圧センサ93により検出された値を、セカンダリ系統液圧Psecとして記憶する。P系統とS系統の制御が１サイクル終了すると、S212においてプライマリ系統液圧Ppri、セカンダリ系統液圧Psecの差圧ΔPを計算する。この時点では、S213の差圧ΔPの絶対値|ΔP|が所定の異常差圧閾値P1以上であるかの判定結果がNoであるため、第１液漏れ検知処理を継続する。 Next, the control system switches to the S system in the sections T11 to T12. In the sections T11 to T12, the S system communication valve 26S is opened, and the P system communication valve 26P is closed. Further, in the hydraulic pressure feedback control in the sections T11 to T12, servo control is performed so that the value detected by the hydraulic pressure sensor 93 coincides with the target wheel cylinder hydraulic pressure Pw *. Therefore, in the section T11 to T12, the hydraulic pressure in the S system increases, and in the P system, the shutoff valve 21P and the communication valve 26P are both closed to form a closed circuit, so the hydraulic pressure should be maintained. . However, since fluid leaks in the P system, the brake fluid flows out to the outside in the sections T11 to T12, and the fluid pressure decreases. At time T12, the control system is switched from the S system to the P system, and the value detected by the hydraulic pressure sensor 93 is stored as the secondary system hydraulic pressure Psec. When the control of the P system and the S system ends, a differential pressure ΔP between the primary system hydraulic pressure Ppri and the secondary system hydraulic pressure Psec is calculated in S212. At this time, since the determination result of whether the absolute value | ΔP | of the differential pressure ΔP in S213 is equal to or greater than the predetermined abnormal differential pressure threshold value P1 is No, the first liquid leakage detection process is continued.
　区間T12～T13では、制御系統がP系統に切り替わる。P系統の液圧は上昇し、S系統の液圧は保持される。時刻T13で制御系統がP系統からS系統に切り替えられ、液圧センサ93により検出された値を、プライマリ系統液圧Ppriとして記憶する。区間T13～T14では、制御系等がS系統に切り替わる。S系統の液圧は上昇し、P系統の液圧は液漏れの影響により低下する。時刻T14で制御系統がS系統からP系統に切り替えられ、液圧センサ93により検出された値を、セカンダリ系統液圧Psecとして記憶する。P系統とS系統の制御が１サイクル終了すると、S212においてプライマリ系統液圧Ppri、セカンダリ系統液圧Psecの差圧ΔPを計算する。この時点では、S213の差圧ΔPの絶対値|ΔP|が所定の異常差圧閾値P1以上であるかの判定結果がNoであるため、第１液漏れ検知処理を継続する。
  以降同様に繰り返すことにより、徐々にP系統の液圧とS系統の液圧との差圧ΔPが増大し、時刻T16でΔPが異常差圧閾値P1に達することで、P系統の液圧失陥が検知される。
  上記のように、第１液漏れ検知処理では、P系統とS系統とを交互に切り替えて増圧と液圧保持とを繰り返すことにより、正常系統には安定的に液圧を発生させつつ、液漏れ系統を検出できる。 In the section T12 to T13, the control system is switched to the P system. The hydraulic pressure of the P system increases and the hydraulic pressure of the S system is maintained. At time T13, the control system is switched from the P system to the S system, and the value detected by the hydraulic pressure sensor 93 is stored as the primary system hydraulic pressure Ppri. In the sections T13 to T14, the control system and the like are switched to the S system. The hydraulic pressure of the S system increases, and the hydraulic pressure of the P system decreases due to the influence of liquid leakage. At time T14, the control system is switched from the S system to the P system, and the value detected by the hydraulic pressure sensor 93 is stored as the secondary system hydraulic pressure Psec. When the control of the P system and the S system ends, a differential pressure ΔP between the primary system hydraulic pressure Ppri and the secondary system hydraulic pressure Psec is calculated in S212. At this time, since the determination result of whether the absolute value | ΔP | of the differential pressure ΔP in S213 is equal to or greater than the predetermined abnormal differential pressure threshold P1 is No, the first liquid leakage detection process is continued.
By repeating in the same manner, the differential pressure ΔP between the hydraulic pressure of the P system and the hydraulic pressure of the S system gradually increases, and when ΔP reaches the abnormal differential pressure threshold P1 at time T16, the hydraulic pressure of the P system is lost. A fall is detected.
As described above, in the first liquid leak detection process, by alternately switching between the P system and the S system and repeating the pressure increase and the fluid pressure holding, the fluid pressure is stably generated in the normal system, A leak system can be detected.
　図８は、液漏れ検知モードで第１液漏れ検知処理のみを実施した場合の液圧制御ユニット6の動作を示すタイムチャートであり、P系統で比較的少量の液漏れ（液漏れ部の開口面積が小さい場合）が発生している。
  時刻T20以前は、目標ホイルシリンダ液圧Pw*が0[MPa]であるため、非制御状態である。
  時刻T20では、目標ホイルシリンダ液圧Pw*が発生し、液圧制御が開始される。
  区間T20～T21では、Ｐ系統が制御系統として選択され、P系統は増圧、S系統は液圧保持となる。時刻T21で制御系統がP系統からS系統に切り替えられ、液圧センサ93により検出された値を、プライマリ系統液圧Ppriとして記憶する。区間T21～T22では、S系統が制御系統として選択され、S系統は増圧、P系統は液圧保持となる。ここで、P系統から漏れは発生しているものの、漏れが比較的少量であることから、P系統で液圧保持の動作を行っている間もほとんど液圧の低下は見られない。 FIG. 8 is a time chart showing the operation of the hydraulic pressure control unit 6 when only the first liquid leakage detection process is performed in the liquid leakage detection mode, and a relatively small amount of liquid leakage (opening of the liquid leakage portion) is performed in the P system. Occurs when the area is small).
Prior to time T20, since the target wheel cylinder hydraulic pressure Pw * is 0 [MPa], it is in an uncontrolled state.
At time T20, target wheel cylinder hydraulic pressure Pw * is generated, and hydraulic pressure control is started.
In the sections T20 to T21, the P system is selected as the control system, the P system is increased in pressure, and the S system is maintained at the hydraulic pressure. At time T21, the control system is switched from the P system to the S system, and the value detected by the hydraulic pressure sensor 93 is stored as the primary system hydraulic pressure Ppri. In the sections T21 to T22, the S system is selected as the control system, the S system is increased in pressure, and the P system is maintained in hydraulic pressure. Here, although leakage has occurred from the P system, since the leakage is relatively small, there is almost no decrease in the hydraulic pressure during the operation of maintaining the hydraulic pressure in the P system.
　時刻T22では、制御系統がS系統からP系統に切り替えられ、液圧センサ93により検出された値を、セカンダリ系統液圧Psecとして記憶する。P系統とS系統の制御が１サイクル終了すると、S212においてプライマリ系統液圧Ppri、セカンダリ系統液圧Psecの差圧ΔPを計算する。この時点では、S213の差圧ΔPの絶対値|ΔP|が所定の異常差圧閾値P1以上であるかの判定結果がNoであるため、第１液漏れ検知処理を継続する。同様に、時刻T22以降、制御系統を切り替えながら液圧を制御しても、P,S両系統共に増圧可能、かつ、保持可能な振る舞いをしている。
  上記のように、漏れが比較的少量である場合は、液漏れ系統の制御性悪化影響を見極めるだけの有意な液圧変化が発生しない場合がある。この課題を解決するためには、制御系統の切り替え周期を長くし、液漏れ系統の減圧影響を大きくすることでP,S両系統間の差圧ΔPを大きくすることが考えられる。しかしながら、この手法では、制御間隔が長くなることで、目標ホイルシリンダ液圧Pw*が変化した場合に大きな左右差圧が生じる可能性があるため、差圧ΔPの検知性悪化や車両挙動の不安定化を招くおそれがある。 At time T22, the control system is switched from the S system to the P system, and the value detected by the hydraulic pressure sensor 93 is stored as the secondary system hydraulic pressure Psec. When the control of the P system and the S system ends, a differential pressure ΔP between the primary system hydraulic pressure Ppri and the secondary system hydraulic pressure Psec is calculated in S212. At this time, since the determination result of whether the absolute value | ΔP | of the differential pressure ΔP in S213 is equal to or greater than the predetermined abnormal differential pressure threshold P1 is No, the first liquid leakage detection process is continued. Similarly, after time T22, even if the hydraulic pressure is controlled while switching the control system, both the P and S systems behave in such a way that the pressure can be increased and maintained.
As described above, when there is a relatively small amount of leakage, there may be a case where a significant change in hydraulic pressure is insufficient to determine the influence of deterioration in controllability of the leakage system. In order to solve this problem, it is conceivable to increase the pressure difference ΔP between the P and S systems by increasing the switching cycle of the control system and increasing the pressure reduction effect of the liquid leakage system. However, in this method, since the control interval becomes longer, a large left-right differential pressure may occur when the target wheel cylinder hydraulic pressure Pw * changes. May lead to stabilization.
　図９は、液漏れ検知モードで第２液漏れ検知処理のみを実施した場合の液圧制御ユニット6の動作を示すタイムチャートであり、P系統で比較的少量の液漏れが発生している。
  時刻T30以前は、目標ホイルシリンダ液圧Pw*が0[MPa]であるため、非制御状態である。
  時刻T30では、目標ホイルシリンダ液圧Pw*が発生し、液圧制御が開始される。遮断弁21P,21Sは閉弁状態、連通弁26P,26Sは開弁状態、モータ7aはON、調圧弁27は閉弁状態（比例制御）となる。ホイルシリンダ8の液漏れが発生しているものの、漏れは比較的少量であるため、液圧制御は問題なく実施できる。
  時刻T31では、P系統およびS系統の液圧が共に目標ホイルシリンダ液圧Pw*に到達する。区間T31～T32では、ホイルシリンダ液圧Pwが目標ホイルシリンダ液圧Pw*に到達したか否かを目標ホイルシリンダ液圧Pw*と各系統の液圧との関係より判断する。
  時刻T32では、第２液漏れ検知処理の実行を開始する。ここで、区間T32～T33では、制御系統としてP系統が選択されている（S301の制御系統の切り替え処理で決定）。ここでは、遮断弁21P,21S、調圧弁27および連通弁26Sは閉弁状態、連通弁26Pは開弁状態、モータ7aはOFFである。このとき、P系統は閉回路を形成しているが、比較的少量の液漏れが発生しているP系統は徐々に液圧が低下する。
  時刻T33で制御系統がP系統から再増圧制御に切り替えられ、ステップS312により、液圧センサ93により検出された値を、プライマリ系統液圧Ppriとして記憶する。 FIG. 9 is a time chart showing the operation of the hydraulic pressure control unit 6 when only the second liquid leakage detection process is performed in the liquid leakage detection mode, and a relatively small amount of liquid leakage occurs in the P system.
Prior to time T30, since the target wheel cylinder hydraulic pressure Pw * is 0 [MPa], it is in an uncontrolled state.
At time T30, target wheel cylinder hydraulic pressure Pw * is generated, and hydraulic pressure control is started. The shutoff valves 21P and 21S are closed, the communication valves 26P and 26S are opened, the motor 7a is ON, and the pressure regulating valve 27 is closed (proportional control). Although the fluid leakage of the wheel cylinder 8 has occurred, the fluid pressure control can be performed without any problem because the leakage is relatively small.
At time T31, the hydraulic pressures of the P system and the S system both reach the target wheel cylinder hydraulic pressure Pw *. In the sections T31 to T32, whether or not the wheel cylinder hydraulic pressure Pw has reached the target wheel cylinder hydraulic pressure Pw * is determined from the relationship between the target wheel cylinder hydraulic pressure Pw * and the hydraulic pressure of each system.
At time T32, execution of the second liquid leakage detection process is started. Here, in the sections T32 to T33, the P system is selected as the control system (determined by the control system switching process in S301). Here, the shutoff valves 21P and 21S, the pressure regulating valve 27, and the communication valve 26S are closed, the communication valve 26P is opened, and the motor 7a is OFF. At this time, the P system forms a closed circuit, but the fluid pressure gradually decreases in the P system where a relatively small amount of liquid leakage occurs.
At time T33, the control system is switched from the P system to the repressurization control, and the value detected by the hydraulic pressure sensor 93 is stored as the primary system hydraulic pressure Ppri in step S312.
　区間T33～T34では、再増圧制御が選択されている（S301の制御系統の切り替え処理で決定）。このとき、再増圧制御移行前の制御系統はP系統であったため、ステップS306により連通弁26Pは閉弁状態、連通弁26Sは開弁状態、モータ7aはON、調圧弁27は閉弁状態(比例制御)とし、目標ホイルシリンダ液圧Pw*が発生し、液圧制御が開始され、時刻T34までにはS系統の液圧が目標ホイルシリンダ液圧Pw*に到達する。
  区間T34～T35では、制御制御としてS系統が選択されている（S302の制御系統の切り替え処理で決定）。ここでは、遮断弁21P,21S、連通弁26Pおよび調圧弁27は閉弁状態、連通弁26Sは開弁状態、モータ7aはOFFである。このとき、S系統は閉回路を形成しているが、液漏れの発生していないS系統は液圧を保持する。時刻T35でステップS313により、液圧センサ93により検出された値を、セカンダリ系統液圧Psecとして記憶する。また、この時点でP系統とS系統の制御が１サイクル終了しているので、ステップS314でYESの判定となり、ステップS316において、ステップS312で記憶したプライマリ系統液圧Ppriと、ステップS313で記憶したセカンダリ系統液圧Psecの差圧ΔPの絶対値|ΔP|が異常差圧閾値P2に達し、P系統の液圧失陥が検知される。
  上記のように、第２液漏れ検知処理では、P系統とS系統とを独立させて液圧を保持する動作を行うことにより、比較的少量な液漏れを検知できる。ただし、第２液漏れ検知処理は、P系統およびS系統の制御を交互に１サイクル実施する必要があるため、目標ホイルシリンダ液圧の変化する場合には、ステップS315のΔPが正しく算出できない。このため、停車時など、目標ホイルシリンダ液圧を一定にできるシーンで実施するのが好ましい。 In the sections T33 to T34, the repressurization control is selected (determined by the control system switching process in S301). At this time, since the control system before the transition to the repressurization control was the P system, the communication valve 26P is closed, the communication valve 26S is opened, the motor 7a is ON, and the pressure regulating valve 27 is closed according to step S306. (Proportional control), the target wheel cylinder hydraulic pressure Pw * is generated, the hydraulic pressure control is started, and the hydraulic pressure of the S system reaches the target foil cylinder hydraulic pressure Pw * by time T34.
In the sections T34 to T35, the S system is selected as the control control (determined by the control system switching process in S302). Here, the shutoff valves 21P and 21S, the communication valve 26P and the pressure regulating valve 27 are closed, the communication valve 26S is opened, and the motor 7a is OFF. At this time, the S system forms a closed circuit, but the S system where no liquid leakage occurs maintains the hydraulic pressure. The value detected by the hydraulic pressure sensor 93 at step T313 at time T35 is stored as the secondary system hydraulic pressure Psec. At this time, since control of the P system and the S system has been completed for one cycle, it is determined YES in step S314, and in step S316, the primary system hydraulic pressure Ppri stored in step S312 and stored in step S313. The absolute value | ΔP | of the differential pressure ΔP of the secondary system hydraulic pressure Psec reaches the abnormal differential pressure threshold P2, and the hydraulic pressure failure of the P system is detected.
As described above, in the second liquid leakage detection process, it is possible to detect a relatively small amount of liquid leakage by performing an operation of maintaining the hydraulic pressure by making the P system and the S system independent. However, in the second liquid leakage detection process, the control of the P system and the S system needs to be alternately performed for one cycle. Therefore, when the target wheel cylinder hydraulic pressure changes, ΔP in step S315 cannot be calculated correctly. For this reason, it is preferable to implement in a scene where the target wheel cylinder hydraulic pressure can be kept constant, such as when the vehicle is stopped.
　図９に示したように、第２液漏れ検知処理では、液漏れ検知のためにP,S両系統で所定液圧を発生させることが前提である。しかしながら、漏れが比較的多量である場合、P,S両系統に液圧を発生できるとは限らず、液漏れ検知を行うための条件を満たせない場合がある。ここで、液漏れの検知前にはホイルシリンダ8をより高圧に保持した方が、流出速度が高まるため、比較的少量の液漏れに対する検知性が向上する。ホイルシリンダ8の液圧が低いと、流出速度が低くなって検知に長い時間が必要となるため、保持液圧はより高い方が好ましい。ところが、液漏れが生じている場合は保持液圧を高くするほど当該液圧を発生できる可能性は低くなる。ここで、所定液圧を発生させるためにポンプ7の流量を増大させることが考えられるが、この場合、リザーバタンク4に残存するブレーキ液を早期に消費することとなり、安全面から好ましくない。 As shown in FIG. 9, the second liquid leak detection process is based on the premise that a predetermined liquid pressure is generated in both the P and S systems for liquid leak detection. However, when there is a relatively large amount of leakage, it is not always possible to generate hydraulic pressure in both the P and S systems, and the conditions for detecting liquid leakage may not be satisfied. Here, before the liquid leakage is detected, if the wheel cylinder 8 is held at a higher pressure, the outflow speed is increased, so that the detectability for a relatively small amount of liquid leakage is improved. When the hydraulic pressure in the wheel cylinder 8 is low, the outflow speed is low and a long time is required for detection. Therefore, it is preferable that the holding hydraulic pressure is higher. However, when liquid leakage occurs, the higher the holding liquid pressure, the lower the possibility that the liquid pressure can be generated. Here, it is conceivable to increase the flow rate of the pump 7 in order to generate a predetermined hydraulic pressure. However, in this case, the brake fluid remaining in the reservoir tank 4 is consumed at an early stage, which is not preferable from the viewpoint of safety.
　図１０は、実施形態１の液漏れ検知モードにおける液圧制御ユニット6の動作を示すタイムチャートであり、P系統で比較的少量の液漏れが発生している。
  時刻T40では、車両は走行しており、時刻T40で制動要求が生じ、ペダルストロークSに応じた目標ホイルシリンダ液圧が設定され、第１の液漏れ検知処理の動作を開始する。液漏れ量は比較的少量であるため、目標ホイルシリンダ液圧Pw*に応じてP,S両系統でホイルシリンダ液圧Pwが発生し、車両は減速する。時刻T41では車両が停車し、目標ホイルシリンダ液圧Pw*は停車時液漏れ検知用の所定液圧Pwsに設定される。これはドライバのブレーキ操作に応じた目標ホイルシリンダ液圧Pw*よりも高く設定される。液圧を高くするのは、漏れの流量を増加させて検知性を高めるためである。ここで、仮に液漏れ量が比較的多量である場合は、第１液漏れ検知処理を実施した時点で、P,S両系統の液圧に明確な差圧が発生するため、第１液漏れ検知処理のみで液漏れ系統を確定できる（図７のような動作となる）。一方、図１０のケースでは、液漏れ量が比較的少量であるため、時刻T42でP,S両系統の液圧は共に停車時液漏れ検知用の所定液圧Pws付近に達する。区間T42～T43では、P,S両系統の液圧がPwsを維持出来ているため、第２液漏れ検知処理の動作を開始する。
  時刻T44では、第2液漏れ検知処理でP,S両系統の差圧が演算され、前記差圧が異常差圧閾値P2を超えるため、S系統よりも低圧なP系統を液漏れ系統と確定する。時刻T44以降は、液圧制御はS系統の片系統倍力モードに移行し、目標ホイルシリンダ液圧Pw*もペダルストロークSに応じた目標ホイルシリンダ液圧Pw*に切り替わる。P系統の液圧を保持する動作は継続するが、ドライバのブレーキ操作終了と共にP系統側の遮断弁21Pを開弁するなどしてP系統の液圧を低下させる。 FIG. 10 is a time chart showing the operation of the hydraulic pressure control unit 6 in the liquid leakage detection mode of the first embodiment, and a relatively small amount of liquid leakage occurs in the P system.
At time T40, the vehicle is traveling, a braking request is generated at time T40, the target wheel cylinder hydraulic pressure corresponding to the pedal stroke S is set, and the operation of the first liquid leakage detection process is started. Since the amount of liquid leakage is relatively small, the wheel cylinder hydraulic pressure Pw is generated in both the P and S systems according to the target wheel cylinder hydraulic pressure Pw *, and the vehicle decelerates. At time T41, the vehicle stops, and the target wheel cylinder hydraulic pressure Pw * is set to a predetermined hydraulic pressure Pws for detecting leakage at the time of stopping. This is set higher than the target wheel cylinder hydraulic pressure Pw * corresponding to the driver's brake operation. The reason for increasing the hydraulic pressure is to increase the leakage flow rate and enhance the detectability. Here, if the amount of liquid leakage is relatively large, a clear differential pressure is generated between the P and S systems when the first liquid leakage detection process is performed. The liquid leakage system can be determined only by the detection process (the operation is as shown in FIG. 7). On the other hand, in the case of FIG. 10, since the amount of liquid leakage is relatively small, the liquid pressures of both the P and S systems reach the vicinity of the predetermined liquid pressure Pws for detecting liquid leakage at the time of stopping at time T42. In the sections T42 to T43, since the fluid pressures of both the P and S systems can maintain Pws, the operation of the second fluid leakage detection process is started.
At time T44, the differential pressure between the P and S systems is calculated in the second liquid leakage detection process, and the differential pressure exceeds the abnormal differential pressure threshold P2, so the P system that is lower in pressure than the S system is determined as the liquid leakage system. To do. After time T44, the hydraulic pressure control shifts to the S-system single-system boost mode, and the target wheel cylinder hydraulic pressure Pw * is also switched to the target wheel cylinder hydraulic pressure Pw * corresponding to the pedal stroke S. Although the operation of maintaining the hydraulic pressure of the P system continues, the hydraulic pressure of the P system is reduced by opening the shutoff valve 21P on the P system side at the end of the driver's brake operation.
　以上のように、実施形態１のブレーキ制御装置1では、ECU100は、連通弁26Pを開弁方向に作動させ、連通弁26Sを閉弁方向に作動させた第１の状態で液圧センサ93によって検出された液圧を取得し、第１の状態の後、連通弁26Pを閉弁方向に作動させ、連通弁26Sを開弁方向に作動させた第２の状態で液圧センサ93によって検出された液圧を取得する。第１の状態では、液圧センサ93が設けられた吐出液路16に対し、P系統の第１液路11B,11a,11dは連通状態となり、S系統の第１液路11B,11b,11cは連通が遮断された状態となる。このため、ECU100は、第１の状態において、液圧センサ93からP系統の第１液路11B,11a,11dの液圧、すなわちプライマリ系統液圧Ppriを取得できる。一方、第２の状態では、吐出液路16に対し、S系統の第１液路11B,11b,11cは連通状態となり、P系統の第１液路11B,11a,11dは連通が遮断された状態となる。このため、ECU100は、第２の状態において、液圧センサ93からS系統の第１液路11B,11b,11cの液圧、すなわちセカンダリ系統液圧Psecを取得できる。よって、ブレーキ制御装置1では、ポンプ7および連通弁26P,26S間に設けられた既存の液圧センサ93を用いて、プライマリ系統液圧Ppriおよびセカンダリ系統液圧Psecを取得できる。よって、プライマリ系統液圧Ppriを検出する液圧センサおよびセカンダリ系統液圧Psecを検出する液圧センサが共に不要であるため、大型化および高コスト化を抑制できる。
  ECU100は、第１の状態で取得されたプライマリ系統液圧Ppriと、第２の状態で取得されたセカンダリ系統液圧Psecと、に基づいて、各系統におけるブレーキ液の液漏れを検出する。これにより、液圧センサ93のみで液漏れ系統の検知が可能である。 As described above, in the brake control device 1 of the first embodiment, the ECU 100 causes the hydraulic pressure sensor 93 to operate in the first state in which the communication valve 26P is operated in the valve opening direction and the communication valve 26S is operated in the valve closing direction. The detected hydraulic pressure is acquired and detected by the hydraulic pressure sensor 93 in the second state in which the communication valve 26P is operated in the valve closing direction and the communication valve 26S is operated in the valve opening direction after the first state. Get the hydraulic pressure. In the first state, the P system first liquid paths 11B, 11a, and 11d are in communication with the discharge liquid path 16 provided with the hydraulic pressure sensor 93, and the S system first liquid paths 11B, 11b, and 11c. Will be disconnected. Therefore, in the first state, the ECU 100 can acquire the hydraulic pressure of the first liquid passages 11B, 11a, 11d of the P system, that is, the primary system hydraulic pressure Ppri from the hydraulic pressure sensor 93. On the other hand, in the second state, the first liquid passages 11B, 11b, 11c of the S system are in communication with the discharge liquid passage 16, and the communication of the first liquid passages 11B, 11a, 11d of the P system is blocked. It becomes a state. For this reason, in the second state, the ECU 100 can acquire the hydraulic pressures of the S system first liquid passages 11B, 11b, and 11c from the hydraulic pressure sensor 93, that is, the secondary system hydraulic pressure Psec. Therefore, the brake control device 1 can acquire the primary system hydraulic pressure Ppri and the secondary system hydraulic pressure Psec using the existing hydraulic pressure sensor 93 provided between the pump 7 and the communication valves 26P and 26S. Therefore, both the hydraulic pressure sensor that detects the primary system hydraulic pressure Ppri and the hydraulic pressure sensor that detects the secondary system hydraulic pressure Psec are not required, so that an increase in size and cost can be suppressed.
The ECU 100 detects a brake fluid leakage in each system based on the primary system fluid pressure Ppri acquired in the first state and the secondary system fluid pressure Psec acquired in the second state. As a result, it is possible to detect the liquid leakage system using only the hydraulic pressure sensor 93.
　ECU100は、両連通弁26P,26Sを開弁方向に作動させた後、ポンプ7を作動させて第１の状態と第２の状態とを交互に繰り返したときの、プライマリ系統液圧Ppriとセカンダリ系統液圧Psecとの差圧ΔPに基づいて、P,S両系統の液漏れを検出する第１液漏れ検知処理を実行する。これにより、第１液漏れ検知処理の実行中、P,S両系統に液漏れが発生していない場合は両系統のホイルシリンダ液圧Pwが徐々に昇圧され、P系統またはS系統に液漏れが発生している場合は正常系統のホイルシリンダ液圧Pwが徐々に昇圧されるため、制動力を発生させつつ液漏れ系統を検出できる。
  ECU100は、両連通弁26P,26Sを開弁方向に作動させてポンプ7を作動させることにより、P,S両系統の液圧を停車時液漏れ検知用の所定液圧Pwsまで昇圧した後、ポンプ7を停止させて第１の状態とし、その後第２の状態としたときの、プライマリ系統液圧Ppriとセカンダリ系統液圧Psecとの差圧ΔPに基づいて、P,S両系統の液漏れを検出する第２液漏れ検知処理を実行する。これにより、第１液漏れ検知処理では検出が難しい少量の液漏れを検出できる。
  ECU100は、第１液漏れ検知処理の実行後、第２液漏れ検知処理を実行する。第２液漏れ検知処理を実行するためには、P,S両系統の液圧を停車時液漏れ検知用の所定液圧Pwsまで高める必要があるが、第２液漏れ検知処理を実行する前に第１液漏れ検知処理を実行することにより、ブレーキ液の漏れ量が比較的少量である場合には確実にP,S両系統の液圧を停車時液漏れ検知用の所定液圧Pwsまで昇圧でき、第２液漏れ検知処理により液漏れ系統を検知できる。一方、ブレーキ液の漏れ量が比較的多量である場合には、第１液漏れ検知処理により液漏れ系統を検知できる。つまり、第１液漏れ検知処理の実行後に第２液漏れ検知処理を実行することにより、ブレーキ液の漏れ量に依らず液漏れ系統の検知精度を向上できる。 The ECU 100 operates the communication valves 26P and 26S in the valve opening direction, and then operates the pump 7 to alternately repeat the first state and the second state. Based on the differential pressure ΔP with respect to the system fluid pressure Psec, a first fluid leak detection process for detecting a fluid leak in both the P and S systems is executed. As a result, during the execution of the first liquid leak detection process, if no liquid leak has occurred in both the P and S systems, the wheel cylinder hydraulic pressure Pw of both systems is gradually increased, and the liquid leaks into the P system or S system. When this occurs, the wheel cylinder hydraulic pressure Pw of the normal system is gradually increased, so that the liquid leakage system can be detected while generating the braking force.
ECU100, after operating both communication valves 26P, 26S in the valve opening direction and operating pump 7, after increasing the fluid pressure of both P, S system to a predetermined fluid pressure Pws for detecting leakage at stop, Based on the differential pressure ΔP between the primary system fluid pressure Ppri and the secondary system fluid pressure Psec when the pump 7 is stopped to be in the first state and then into the second state, the liquid leakage of both the P and S systems A second liquid leakage detection process is performed to detect. Thereby, a small amount of liquid leak that is difficult to detect in the first liquid leak detection process can be detected.
The ECU 100 executes the second liquid leak detection process after executing the first liquid leak detection process. In order to execute the second liquid leak detection process, it is necessary to increase the hydraulic pressures of both the P and S systems to a predetermined liquid pressure Pws for detecting a liquid leak when the vehicle is stopped, but before executing the second liquid leak detection process. By executing the first fluid leakage detection process at the same time, when the amount of brake fluid leakage is relatively small, it is ensured that the fluid pressure in both the P and S systems reaches the predetermined fluid pressure Pws for detecting fluid leakage during stoppage. The pressure can be increased, and the liquid leakage system can be detected by the second liquid leakage detection process. On the other hand, when the amount of leakage of the brake fluid is relatively large, the fluid leakage system can be detected by the first fluid leakage detection process. That is, by executing the second liquid leak detection process after the first liquid leak detection process, the detection accuracy of the liquid leak system can be improved regardless of the amount of brake fluid leak.
　ECU100は、第１液漏れ検知処理の実行後、P,S両系統で所定液圧Pwsの発生が確認できた場合に、第２液漏れ検知処理を実行する。第２液漏れ検知処理は、P,S両系統で液圧を発生させることが前提であるため、第２液漏れ検知処理による液漏れ検知を行うための条件を満たした場合にのみ第２液漏れ検知処理を実行することにより、不要な第２液漏れ検知処理の実行を抑制できる。
  ECU100は、第１液漏れ検知処理を停車中に実行する。第１液漏れ検知処理ではP系統とS系統とを交互に切り替えて増圧と液圧保持とを繰り返すため、走行中であって制動要求がない場合には、ドライバの意図しない車両挙動（減速度の変化）が生じる。一方、停車中は第１液漏れ検知処理を実行してもドライバの意図しない車両挙動は生じない。
  ECU100は、第２液漏れ検知処理を停車中に実行する。第２液漏れ検知処理中は、連通弁26P,26Sを交互に閉弁して、再増圧制御以外の制御時は、モータ7aは非作動とするため、目標ホイルシリンダ液圧Pw*の変化に追従できない。一方、停車中は目標ホイルシリンダ液圧Pw*を一定に維持できるため、第２液漏れ検知処理を実行してもドライバの意図しない車両挙動（減速度の変化）は生じない。
  ECU100は、第１液漏れ検知処理中、第１の状態の開始（第１液漏れ検知処理の開始）から第２の状態の終了（第２液漏れ検知処理の修旅）までの期間を１サイクルとしたとき、１サイクルの終了毎に差圧ΔPを算出して液漏れを検出する。これにより、複数サイクルの終了時に液漏れを検出する場合と比べて、より早期に液漏れ系統を検出できる。 The ECU 100 executes the second liquid leak detection process when the generation of the predetermined liquid pressure Pws can be confirmed in both the P and S systems after the execution of the first liquid leak detection process. Since the second liquid leak detection process is based on the premise that the hydraulic pressure is generated in both the P and S systems, the second liquid leak detection process is performed only when the conditions for performing the liquid leak detection by the second liquid leak detection process are satisfied. By executing the leak detection process, it is possible to suppress unnecessary execution of the second liquid leak detection process.
The ECU 100 executes the first liquid leak detection process while the vehicle is stopped. In the first liquid leakage detection process, the P system and the S system are alternately switched to repeat the pressure increase and the fluid pressure maintenance. Therefore, when there is no braking request while driving, the vehicle behavior (reduction by the driver) is not intended. Speed change). On the other hand, even when the first liquid leakage detection process is executed while the vehicle is stopped, the vehicle behavior not intended by the driver does not occur.
The ECU 100 executes the second liquid leak detection process while the vehicle is stopped. During the second liquid leak detection process, the communication valves 26P and 26S are alternately closed, and the motor 7a is inactivated during the control other than the repressurization control, so the change in the target wheel cylinder hydraulic pressure Pw * I cannot follow. On the other hand, since the target wheel cylinder hydraulic pressure Pw * can be kept constant while the vehicle is stopped, the vehicle behavior (change in deceleration) not intended by the driver does not occur even when the second liquid leakage detection process is executed.
The ECU 100 sets a period from the start of the first state (start of the first liquid leak detection process) to the end of the second state (trip of the second liquid leak detection process) during the first liquid leak detection process. When a cycle is set, a differential pressure ΔP is calculated every time one cycle is completed, and a liquid leak is detected. Thereby, compared with the case where a liquid leak is detected at the end of a plurality of cycles, the liquid leak system can be detected earlier.
　〔実施形態２〕
  実施形態２のブレーキ装置の基本的な構成は実施形態１と同じであるため、実施形態１と異なる部分のみ説明する。
  図１１は、実施形態２の液漏れ検知モードにおける処理の流れを示すフローチャートである。ECU100のフェールセーフ部103は、液漏れ検知モードを実行するための構成として、第１液漏れ検知実行状態判定部113を有する。
  ステップS117では、第１液漏れ検知実行状態判定部113において、第１液漏れ検知処理のP系統とS系統の制御サイクル数を計測する。
  ステップS118では、第１液漏れ検知実行状態判定部113において、第１液漏れ検知処理でP系統とS系統の制御サイクル数が所定以上であるかを判定する。YESの場合はステップS113へ進み、NOの場合は本処理を終了する。
  実施形態２のブレーキ制御装置1では、ECU100は、第１液漏れ検知処理においてP系統の制御（第１の状態）とS系統の制御（第２の状態）との切り替えを所定回数行った後、第２液漏れ検知処理を実行する。つまり、第１液漏れ検知処理にある程度の時間をかけても液漏れ系統が検知できないということは、ブレーキ液の漏れ量が比較的少量であることを意味している。よって、この場合は第１液漏れ検知処理から第２液漏れ検知処理へ移行することにより、液漏れ系統の検知時間が不要に延びるのを抑制できる。 [Embodiment 2]
Since the basic configuration of the brake device of the second embodiment is the same as that of the first embodiment, only the parts different from the first embodiment will be described.
FIG. 11 is a flowchart showing the flow of processing in the liquid leakage detection mode of the second embodiment. The fail safe unit 103 of the ECU 100 includes a first liquid leak detection execution state determination unit 113 as a configuration for executing the liquid leak detection mode.
In step S117, the first liquid leakage detection execution state determination unit 113 measures the number of control cycles of the P system and the S system in the first liquid leakage detection process.
In step S118, the first liquid leakage detection execution state determination unit 113 determines whether the number of control cycles of the P system and the S system is greater than or equal to a predetermined value in the first liquid leakage detection process. If YES, the process proceeds to step S113, and if NO, this process ends.
In the brake control device 1 of the second embodiment, the ECU 100 performs a predetermined number of times of switching between control of the P system (first state) and control of the S system (second state) in the first liquid leakage detection process. Then, the second liquid leakage detection process is executed. That is, the fact that the liquid leakage system cannot be detected even if the first liquid leakage detection process takes a certain amount of time means that the amount of leakage of the brake fluid is relatively small. Therefore, in this case, by shifting from the first liquid leak detection process to the second liquid leak detection process, it is possible to suppress an unnecessary increase in the detection time of the liquid leak system.
　〔他の実施形態〕
  以上、本発明を実施するための実施形態を説明したが、本発明の具体的な構成は実施形態の構成に限定されるものではなく、発明の要旨を逸脱しない範囲の設計変更等があっても本発明に含まれる。
  液圧源はポンプ7のみで構成されたものを記載したが、これにアキュムレータのような蓄圧装置を組み合わせても構わない。液圧制御ユニットは、マスタシリンダ3、液圧制御ユニット6、ストロークシミュレータ5が一体化された一体型であってもよいし、いずれかがより分割された複数のユニットで構成されていてもよい。
  図２のステップS1の条件、すなわち失陥系統検知のための動作へ遷移するための条件は、液漏れ失陥が疑われる条件であればよい。例えば、目標ホイルシリンダ液圧と実際のホイルシリンダ液圧との偏差が所定値以上となったことを条件として、失陥系統検知のための動作へ遷移することも可能である。
  図３のステップS115では、P系統とS系統の制御が１サイクル終了しているかの判定をしているが、液漏れ系統の検知精度を向上させるため、P系統とS系統の制御が所定サイクル終了しているかの判定としてもよい。 [Other Embodiments]
Although the embodiment for carrying out the present invention has been described above, the specific configuration of the present invention is not limited to the configuration of the embodiment, and there are design changes and the like within the scope not departing from the gist of the invention. Are also included in the present invention.
Although the fluid pressure source is composed of only the pump 7, it may be combined with a pressure accumulator such as an accumulator. The hydraulic pressure control unit may be an integrated type in which the master cylinder 3, the hydraulic pressure control unit 6, and the stroke simulator 5 are integrated, or any one of them may be configured by a plurality of divided units. .
The condition in step S1 in FIG. 2, that is, the condition for making a transition to the operation for detecting a faulty system may be a condition in which a liquid leak failure is suspected. For example, it is possible to shift to an operation for detecting a faulty system on condition that the deviation between the target wheel cylinder hydraulic pressure and the actual wheel cylinder hydraulic pressure is equal to or greater than a predetermined value.
In step S115 in FIG. 3, it is determined whether the control of the P system and the S system has been completed for one cycle. In order to improve the detection accuracy of the liquid leakage system, the control of the P system and the S system is performed in a predetermined cycle. It is good also as determination of whether it is complete | finished.
　第１液漏れ検知処理における失陥系統の検知は、図４のS212～S214に示したものに限らない。例えば、目標ホイルシリンダ液圧Pw*と各系統の差圧をそれぞれ監視してもよい。また、差圧ΔPの絶対値|ΔP|が異常差圧閾値P1を超えた状態が一定時間継続した場合に失陥系統を確定してもよい。また、差圧ΔPの積分値が所定値を超えた場合に失陥系統を確定してもよいし、差圧ΔPを評価する様々な手法を適用できる。
  第２液漏れ検知処理における失陥系統の検知は、図６のS315～S317に示したものに限らない。例えば、停車時液漏れ検知用の目標ホイルシリンダ液圧Pwsと各系統の差圧をそれぞれ監視してもよい。また、異常差圧閾値P2を超えた状態が一定時間継続した場合に失陥系統を確定してもよい。また、差圧ΔPの積分値が所定値を超えた場合に失陥系統を確定してもよいし、差圧ΔPを評価する様々な手法を適用できる。
  図４のS202において、停車中は走行中よりも制御系統の切り替え時間を長くしてもよい。走行中に切り替え時間を長くするほど一度の増圧量または減圧量は多くなるため、P,S両系統間に大きな差圧が生じ、車両挙動に影響を及ぼす可能性がある。一方、停車中はP,S両系統間に差圧が生じても車両挙動に影響はなく、液漏れ系統を早期に検知できる。 Detection of the faulty system in the first liquid leakage detection process is not limited to that shown in S212 to S214 of FIG. For example, the target wheel cylinder hydraulic pressure Pw * and the differential pressure of each system may be monitored. Further, the faulty system may be determined when a state in which the absolute value | ΔP | of the differential pressure ΔP exceeds the abnormal differential pressure threshold value P1 continues for a certain time. Further, when the integrated value of the differential pressure ΔP exceeds a predetermined value, the failed system may be determined, or various methods for evaluating the differential pressure ΔP can be applied.
Detection of the faulty system in the second liquid leakage detection process is not limited to that shown in S315 to S317 of FIG. For example, the target wheel cylinder hydraulic pressure Pws for detecting leakage at the time of stopping and the differential pressure of each system may be monitored. Further, the faulty system may be determined when the state in which the abnormal differential pressure threshold P2 is exceeded for a certain period of time. Further, when the integrated value of the differential pressure ΔP exceeds a predetermined value, the failed system may be determined, and various methods for evaluating the differential pressure ΔP can be applied.
In S202 of FIG. 4, the control system switching time may be longer when the vehicle is stopped than when the vehicle is traveling. As the switching time is increased during traveling, the amount of pressure increase or decrease in pressure increases. Therefore, a large differential pressure is generated between the P and S systems, which may affect vehicle behavior. On the other hand, even if a differential pressure is generated between the P and S systems while the vehicle is stopped, the vehicle behavior is not affected, and the liquid leakage system can be detected early.
　以上説明した実施形態から把握し得る技術的思想について、以下に記載する。
  ブレーキ制御装置は、その一つの態様において、ブレーキ液圧に応じて車輪に制動力を付与する第１の制動力付与部に接続する第１の接続液路と、ブレーキ液圧に応じて車輪に制動力を付与する第２の制動力付与部に接続する第２の接続液路と、前記第１の接続液路と、前記第２の接続液路と、を接続する連通液路と、前記連通液路に設けられた第１の連通弁と、前記連通液路に設けられた第２の連通弁と、前記連通液路のうち、前記第１の連通弁と、前記第２の連通弁と、の間にブレーキ液を吐出する液圧源と、前記液圧源と前記第１の連通弁との間、または前記液圧源と前記第２の連通弁との間、の液路に設けられた圧力センサと、前記第１の連通弁を開弁方向に作動させ、前記第２の連通弁を閉弁方向に作動させた第１の状態で前記圧力センサによって検出された第１の圧力に関する物理量を取得し、前記第１の状態の後、前記第１の連通弁を閉弁方向に作動させ、前記第２の連通弁を開弁方向に作動させた第２の状態で前記圧力センサによって検出された第２の圧力に関する物理量を取得するコントロールユニットと、を備える。 The technical idea that can be grasped from the embodiment described above will be described below.
In one aspect thereof, the brake control device includes a first connection fluid path connected to a first braking force applying unit that applies braking force to the wheel according to the brake fluid pressure, and a wheel according to the brake fluid pressure. A second connecting liquid path that connects to a second braking force applying section that applies a braking force, the first connecting liquid path, and a communicating liquid path that connects the second connecting liquid path; A first communication valve provided in the communication liquid path; a second communication valve provided in the communication liquid path; and the first communication valve and the second communication valve among the communication liquid paths. Between a hydraulic pressure source for discharging brake fluid between the hydraulic pressure source and the first communication valve, or between the hydraulic pressure source and the second communication valve. The pressure sensor and the first communication valve are operated in the valve opening direction and the second communication valve is operated in the valve closing direction. A physical quantity related to the first pressure detected by the sensor is acquired, and after the first state, the first communication valve is operated in the valve closing direction, and the second communication valve is operated in the valve opening direction. And a control unit for acquiring a physical quantity related to the second pressure detected by the pressure sensor in the second state.
　より好ましい態様では、上記態様において、前記コントロールユニットは、取得された前記第１の圧力に関する物理量と、取得された前記第２の圧力に関する物理量と、に基づいて、前記第１の接続液路または前記第２の接続液路におけるブレーキ液の液漏れを検出する。
  別の好ましい態様では、上記態様のいずれかにおいて、前記コントロールユニットは、前記第１の連通弁および前記第２の連通弁を開弁方向に作動させた後、前記液圧源を作動させて前記第１の状態と前記第２の状態とを交互に繰り返したときの、前記第１の圧力に関する物理量と、前記第２の圧力に関する物理量と、に基づいて、前記液漏れを検出する第１液漏れ検知処理を実行する。
  別の好ましい態様では、上記態様のいずれかにおいて、前記コントロールユニットは、前記第１の連通弁および前記第２の連通弁を開弁方向に作動させて前記液圧源を作動させた後、前記液圧源を停止させて前記第１の状態とし、その後前記第２の状態としたときの、前記第１の圧力に関する物理量と、前記第２の圧力に関する物理量と、に基づいて、前記液漏れを検出する第２液漏れ検知処理を実行する。
  さらに別の好ましい態様では、上記態様のいずれかにおいて、前記コントロールユニットは、前記第１液漏れ検知処理の実行後、前記第２液漏れ検知処理を実行する。 In a more preferred aspect, in the above aspect, the control unit is configured such that the first connection liquid path or the control unit is based on the acquired physical quantity related to the first pressure and the acquired physical quantity related to the second pressure. Brake fluid leakage in the second connection fluid path is detected.
In another preferred aspect, in any one of the above aspects, the control unit operates the hydraulic pressure source after operating the first communication valve and the second communication valve in a valve opening direction. A first liquid that detects the liquid leakage based on a physical quantity related to the first pressure and a physical quantity related to the second pressure when the first state and the second state are alternately repeated. Perform leak detection processing.
In another preferred aspect, in any one of the above aspects, the control unit operates the hydraulic pressure source after operating the first communication valve and the second communication valve in a valve opening direction. Based on the physical quantity related to the first pressure and the physical quantity related to the second pressure when the hydraulic pressure source is stopped to enter the first state and then to the second state, the liquid leakage A second liquid leakage detection process is performed to detect.
In still another preferred aspect, in any one of the above aspects, the control unit executes the second liquid leak detection process after executing the first liquid leak detection process.
　さらに別の好ましい態様では、上記態様のいずれかにおいて、前記コントロールユニットは、前記第１液漏れ検知処理の実行後、前記第１の接続液路および前記第２の接続液路に所定の液圧が発生している場合に、前記第２液漏れ検知処理を実行する。
  さらに別の好ましい態様では、上記態様のいずれかにおいて、前記コントロールユニットは、前記第１液漏れ検知処理において前記第１の状態と前記第２の状態との切り替えを所定回数行った後、前記第２液漏れ検知処理を実行する。
  さらに別の好ましい態様では、上記態様のいずれかにおいて、前記コントロールユニットは、前記第１液漏れ検知処理および前記第２液漏れ検知処理を停車中に実行する。
  さらに別の好ましい態様では、上記態様のいずれかにおいて、前記コントロールユニットは、前記第１の状態の開始から前記第２の状態の終了までの期間を１サイクルとしたとき、前記１サイクルの終了毎に前記液漏れを検出する。
  さらに別の好ましい態様では、上記態様のいずれかにおいて、前記コントロールユニットは、前記第２液漏れ検知処理を停車中に実行する。 In still another preferred aspect, in any one of the above aspects, the control unit has a predetermined hydraulic pressure in the first connection liquid path and the second connection liquid path after the execution of the first liquid leak detection process. The second liquid leakage detection process is executed when the above has occurred.
In still another preferred aspect, in any one of the above aspects, the control unit performs the switching between the first state and the second state a predetermined number of times in the first liquid leakage detection process, and then A two-liquid leak detection process is executed.
In still another preferred aspect, in any one of the above aspects, the control unit executes the first liquid leak detection process and the second liquid leak detection process while the vehicle is stopped.
In yet another preferred aspect, in any one of the above aspects, the control unit has a cycle from the start of the first state to the end of the second state as one cycle. The liquid leak is detected.
In still another preferred aspect, in any one of the above aspects, the control unit executes the second liquid leakage detection process while the vehicle is stopped.
　また、他の観点から、ブレーキ制御装置の異常検出方法は、ある態様において、ブレーキ液圧に応じて車輪に制動力を付与する第１の制動力付与部に接続する第１の接続液路と、ブレーキ液圧に応じて車輪に制動力を付与する第２の制動力付与部に接続する第２の接続液路と、前記第１の接続液路と、前記第２の接続液路と、を接続する連通液路と、前記連通液路に設けられた第１の連通弁と、前記連通液路に設けられた第２の連通弁と、前記連通液路のうち、前記第１の連通弁と、前記第２の連通弁と、の間にブレーキ液を吐出する液圧源と、前記液圧源と前記第１の連通弁との間、または前記液圧源と前記第２の連通弁との間、の液路に設けられた圧力センサと、を備えるブレーキ制御装置の異常検出方法であって、前記第１の連通弁を開弁方向に作動させ、前記第２の連通弁を閉弁方向に作動させた第１の状態で前記圧力センサによって検出された第１の圧力に関する物理量を取得し、前記第１の状態の後、前記第１の連通弁を閉弁方向に作動させ、前記第２の連通弁を開弁方向に作動させた第２の状態で前記圧力センサによって検出された第２の圧力に関する物理量を取得し、取得された前記第１の圧力に関する物理量と、取得された前記第２の圧力に関する物理量と、に基づいて、前記第１の接続液路または前記第２の接続液路におけるブレーキ液の液漏れを検出する。 In another aspect, the abnormality detection method for the brake control device according to another aspect includes a first connection fluid path connected to a first braking force application unit that applies a braking force to the wheel according to the brake fluid pressure. A second connection liquid path connected to a second braking force applying unit that applies a braking force to the wheel according to the brake hydraulic pressure, the first connection liquid path, and the second connection liquid path, Of the communication liquid path, the first communication valve provided in the communication liquid path, the second communication valve provided in the communication liquid path, and the first communication among the communication liquid paths. A hydraulic pressure source for discharging brake fluid between the valve and the second communication valve; and between the hydraulic pressure source and the first communication valve or between the hydraulic pressure source and the second communication valve. An abnormality detection method for a brake control device comprising: a pressure sensor provided in a fluid path between the first and second valves; A physical quantity relating to a first pressure detected by the pressure sensor in a first state in which the second communication valve is operated in the valve closing direction is acquired in the first state, and after the first state Obtaining a physical quantity related to the second pressure detected by the pressure sensor in a second state in which the first communication valve is operated in the valve closing direction and the second communication valve is operated in the valve opening direction. Based on the acquired physical quantity related to the first pressure and the acquired physical quantity related to the second pressure, the brake fluid leaks in the first connection liquid path or the second connection liquid path Is detected.
　尚、本発明は上記した実施形態に限定されるものではなく、様々な変形例が含まれる。例えば、上記した実施形態は本発明を分かりやすく説明するために詳細に説明したものであり、必ずしも説明した全ての構成を備えるものに限定されるものではない。また、ある実施形態の構成の一部を他の実施形態の構成に置き換えることが可能であり、また、ある実施形態の構成に他の実施形態の構成を加えることも可能である。また、各実施形態の構成の一部について、他の構成の追加・削除・置換をすることが可能である。 In addition, this invention is not limited to above-described embodiment, Various modifications are included. For example, the above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to one having all the configurations described. Further, a part of the configuration of an embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of an embodiment. In addition, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.
　本願は、２０１８年５月３１日付出願の日本国特許出願第２０１８－１０４４９４号に基づく優先権を主張する。２０１８年５月３１日付出願の日本国特許出願第２０１８－１０４４９４号の明細書、特許請求の範囲、図面、及び要約書を含む全開示内容は、参照により本願に全体として組み込まれる。 This application claims priority based on Japanese Patent Application No. 2018-104494 filed on May 31, 2018. The entire disclosure including the specification, claims, drawings, and abstract of Japanese Patent Application No. 2018-104494, filed May 31, 2018, is hereby incorporated by reference in its entirety.
1  ブレーキ制御装置7  ポンプ（液圧源）8a,8d  ホイルシリンダ（第１の制動力付与部）8b,8c  ホイルシリンダ（第２の制動力付与部）11P,11a,11d  第１液路（第１の接続液路）11S,11b,11c  第１液路（第２の接続液路）16P  吐出液路（連通液路）16S  吐出液路（連通液路）26P  連通弁（第１の連通弁）26S  連通弁（第２の連通弁）93　液圧センサ（圧力センサ）100  ECU（コントロールユニット）FL～RR　車輪 1 brake control device 7 pump (hydraulic pressure source) 8a, 8d wheel cylinder (first braking force applying portion) 8b, 8c wheel cylinder (second braking force applying portion) 11P, 11a, 11d first fluid path (first 1 connection liquid path) 11S, 11b, 11c first liquid path (second connection liquid path) 16P discharge liquid path (communication liquid path) 16S discharge liquid path (communication liquid path) 26P communication valve (first communication valve) ) 26S communication valve (second communication valve) 93 Fluid pressure sensor (pressure sensor) 100 ECU (control unit) FL ~ RR wheel

Claims (13)

  1. 　ブレーキ液圧に応じて車輪に制動力を付与する第１の制動力付与部に接続する第１の接続液路と、
    　ブレーキ液圧に応じて車輪に制動力を付与する第２の制動力付与部に接続する第２の接続液路と、
    　前記第１の接続液路と、前記第２の接続液路と、を接続する連通液路と、
    　前記連通液路に設けられた第１の連通弁と、
    　前記連通液路に設けられた第２の連通弁と、
    　前記連通液路のうち、前記第１の連通弁と、前記第２の連通弁と、の間にブレーキ液を吐出する液圧源と、
    　前記液圧源と前記第１の連通弁との間、または前記液圧源と前記第２の連通弁との間、の液路に設けられた圧力センサと、
    　前記第１の連通弁を開弁方向に作動させ、前記第２の連通弁を閉弁方向に作動させた第１の状態で前記圧力センサによって検出された第１の圧力に関する物理量を取得し、
    　前記第１の状態の後、前記第１の連通弁を閉弁方向に作動させ、前記第２の連通弁を開弁方向に作動させた第２の状態で前記圧力センサによって検出された第２の圧力に関する物理量を取得するコントロールユニットと、
    　を備えるブレーキ制御装置。     A first connection fluid path connected to a first braking force application unit that applies a braking force to the wheel according to the brake fluid pressure;
    A second connecting fluid path connected to a second braking force applying unit that applies a braking force to the wheel according to the brake fluid pressure;
    A communication liquid path connecting the first connection liquid path and the second connection liquid path;
    A first communication valve provided in the communication liquid path;
    A second communication valve provided in the communication liquid path;
    A hydraulic pressure source for discharging brake fluid between the first communication valve and the second communication valve in the communication fluid path;
    A pressure sensor provided in a fluid path between the fluid pressure source and the first communication valve or between the fluid pressure source and the second communication valve;
    Obtaining a physical quantity relating to a first pressure detected by the pressure sensor in a first state in which the first communication valve is operated in the valve opening direction and the second communication valve is operated in the valve closing direction;
    After the first state, the second state detected by the pressure sensor in the second state in which the first communication valve is operated in the valve closing direction and the second communication valve is operated in the valve opening direction. A control unit that obtains physical quantities related to the pressure of
    A brake control device comprising:
  2. 　請求項１に記載のブレーキ制御装置において、
    　前記コントロールユニットは、取得された前記第１の圧力に関する物理量と、取得された前記第２の圧力に関する物理量と、に基づいて、前記第１の接続液路または前記第２の接続液路におけるブレーキ液の液漏れを検出するブレーキ制御装置。     The brake control device according to claim 1, wherein
    The control unit is configured to perform braking in the first connection liquid path or the second connection liquid path based on the acquired physical quantity related to the first pressure and the acquired physical quantity related to the second pressure. Brake control device that detects liquid leakage.
  3. 　請求項２に記載のブレーキ制御装置において、
    　前記コントロールユニットは、前記第１の連通弁および前記第２の連通弁を開弁方向に作動させた後、前記液圧源を作動させて前記第１の状態と前記第２の状態とを交互に繰り返したときの、前記第１の圧力に関する物理量と、前記第２の圧力に関する物理量と、に基づいて、前記液漏れを検出する第１液漏れ検知処理を実行するブレーキ制御装置。     The brake control device according to claim 2,
    The control unit operates the hydraulic pressure source after operating the first communication valve and the second communication valve in the valve opening direction to alternately switch the first state and the second state. A brake control device that executes a first liquid leak detection process for detecting the liquid leak based on the physical quantity related to the first pressure and the physical quantity related to the second pressure.
  4. 　請求項３に記載のブレーキ制御装置において、
    　前記コントロールユニットは、前記第１の連通弁および前記第２の連通弁を開弁方向に作動させて前記液圧源を作動させた後、前記液圧源を停止させて前記第１の状態とし、その後前記第２の状態としたときの、前記第１の圧力に関する物理量と、前記第２の圧力に関する物理量と、に基づいて、前記液漏れを検出する第２液漏れ検知処理を実行するブレーキ制御装置。     The brake control device according to claim 3,
    The control unit operates the hydraulic pressure source by operating the first communication valve and the second communication valve in a valve opening direction, and then stops the hydraulic pressure source to enter the first state. Then, the brake that executes the second liquid leakage detection process for detecting the liquid leakage based on the physical quantity related to the first pressure and the physical quantity related to the second pressure when the second state is set. Control device.
  5. 　請求項４に記載のブレーキ制御装置において、
    　前記コントロールユニットは、前記第１液漏れ検知処理の実行後、前記第２液漏れ検知処理を実行するブレーキ制御装置。     The brake control device according to claim 4, wherein
    The said control unit is a brake control apparatus which performs a said 2nd liquid leak detection process after execution of a said 1st liquid leak detection process.
  6. 　請求項５に記載のブレーキ制御装置において、
    　前記コントロールユニットは、前記第１液漏れ検知処理の実行後、前記第１の接続液路および前記第２の接続液路に所定の液圧が発生している場合に、前記第２液漏れ検知処理を実行するブレーキ制御装置。     The brake control device according to claim 5,
    The control unit detects the second liquid leak when a predetermined liquid pressure is generated in the first connection liquid path and the second connection liquid path after the execution of the first liquid leak detection process. Brake control device that executes processing.
  7. 　請求項５に記載のブレーキ制御装置において、
    　前記コントロールユニットは、前記第１液漏れ検知処理において前記第１の状態と前記第２の状態との切り替えを所定回数行った後、前記第２液漏れ検知処理を実行するブレーキ制御装置。     The brake control device according to claim 5,
    The said control unit is a brake control apparatus which performs a said 2nd liquid leak detection process, after switching the said 1st state and the said 2nd state predetermined times in the said 1st liquid leak detection process.
  8. 　請求項４に記載のブレーキ制御装置において、
    　前記コントロールユニットは、前記第１液漏れ検知処理および前記第２液漏れ検知処理を停車中に実行するブレーキ制御装置。     The brake control device according to claim 4, wherein
    The control unit is a brake control device that executes the first liquid leak detection process and the second liquid leak detection process while the vehicle is stopped.
  9. 　請求項３に記載のブレーキ制御装置において、
    　前記コントロールユニットは、前記第１の状態の開始から前記第２の状態の終了までの期間を１サイクルとしたとき、前記１サイクルの終了毎に前記液漏れを検出するブレーキ制御装置。     The brake control device according to claim 3,
    The said control unit is a brake control apparatus which detects the said liquid leak for every completion | finish of the said 1 cycle, when the period from the start of the said 1st state to the completion | finish of the said 2nd state is 1 cycle.
  10. 　請求項２に記載のブレーキ制御装置において、
    　前記コントロールユニットは、前記第１の連通弁および前記第２の連通弁を開弁方向に作動させて前記液圧源を作動させた後、前記液圧源を停止させて前記第１の状態とし、その後前記第２の状態としたときの、前記第１の圧力に関する物理量と、前記第２の圧力に関する物理量と、に基づいて、前記液漏れを検出する第２液漏れ検知処理を実行するブレーキ制御装置。     The brake control device according to claim 2,
    The control unit operates the hydraulic pressure source by operating the first communication valve and the second communication valve in a valve opening direction, and then stops the hydraulic pressure source to enter the first state. Then, the brake that executes the second liquid leakage detection process for detecting the liquid leakage based on the physical quantity related to the first pressure and the physical quantity related to the second pressure when the second state is set. Control device.
  11. 　請求項１０に記載のブレーキ制御装置において、
    　前記コントロールユニットは、前記第２液漏れ検知処理を停車中に実行するブレーキ制御装置。     The brake control device according to claim 10,
    The control unit is a brake control device that executes the second leakage detection process while the vehicle is stopped.
  12. 　請求項２に記載のブレーキ制御装置において、
    　前記コントロールユニットは、前記第１の状態の開始から前記第２の状態の終了までの期間を１サイクルとしたとき、前記１サイクルの終了毎に前記液漏れを検出するブレーキ制御装置。     The brake control device according to claim 2,
    The said control unit is a brake control apparatus which detects the said liquid leak for every completion | finish of the said 1 cycle, when the period from the start of the said 1st state to the completion | finish of the said 2nd state is 1 cycle.
  13. 　ブレーキ液圧に応じて車輪に制動力を付与する第１の制動力付与部に接続する第１の接続液路と、
    　ブレーキ液圧に応じて車輪に制動力を付与する第２の制動力付与部に接続する第２の接続液路と、
    　前記第１の接続液路と、前記第２の接続液路と、を接続する連通液路と、
    　前記連通液路に設けられた第１の連通弁と、
    　前記連通液路に設けられた第２の連通弁と、
    　前記連通液路のうち、前記第１の連通弁と、前記第２の連通弁と、の間にブレーキ液を吐出する液圧源と、
    　前記液圧源と前記第１の連通弁との間、または前記液圧源と前記第２の連通弁との間、の液路に設けられた圧力センサと、
    　を備えるブレーキ制御装置の異常検出方法であって、
    　前記第１の連通弁を開弁方向に作動させ、前記第２の連通弁を閉弁方向に作動させた第１の状態で前記圧力センサによって検出された第１の圧力に関する物理量を取得し、
    　前記第１の状態の後、前記第１の連通弁を閉弁方向に作動させ、前記第２の連通弁を開弁方向に作動させた第２の状態で前記圧力センサによって検出された第２の圧力に関する物理量を取得し、
    　取得された前記第１の圧力に関する物理量と、取得された前記第２の圧力に関する物理量と、に基づいて、前記第１の接続液路または前記第２の接続液路におけるブレーキ液の液漏れを検出するブレーキ制御装置の異常検出方法。     A first connection fluid path connected to a first braking force application unit that applies a braking force to the wheel according to the brake fluid pressure;
    A second connecting fluid path connected to a second braking force applying unit that applies a braking force to the wheel according to the brake fluid pressure;
    A communication liquid path connecting the first connection liquid path and the second connection liquid path;
    A first communication valve provided in the communication liquid path;
    A second communication valve provided in the communication liquid path;
    A hydraulic pressure source for discharging brake fluid between the first communication valve and the second communication valve in the communication fluid path;
    A pressure sensor provided in a fluid path between the fluid pressure source and the first communication valve or between the fluid pressure source and the second communication valve;
    An abnormality detection method for a brake control device comprising:
    Obtaining a physical quantity relating to a first pressure detected by the pressure sensor in a first state in which the first communication valve is operated in the valve opening direction and the second communication valve is operated in the valve closing direction;
    After the first state, the second state detected by the pressure sensor in the second state in which the first communication valve is operated in the valve closing direction and the second communication valve is operated in the valve opening direction. The physical quantity related to the pressure of
    Based on the acquired physical quantity related to the first pressure and the acquired physical quantity related to the second pressure, leakage of brake fluid in the first connection liquid path or the second connection liquid path is reduced. An abnormality detection method for a brake control device to detect.
PCT/JP2019/020428 2018-05-31 2019-05-23 Brake control device and method for detecting malfunction in brake control device WO2019230547A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2018104494A JP2019209707A (en) 2018-05-31 2018-05-31 Brake control device and method of detecting error of brake control device
JP2018-104494 2018-05-31

Publications (1)

Publication Number Publication Date
WO2019230547A1 true WO2019230547A1 (en) 2019-12-05

Family

ID=68698789

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2019/020428 WO2019230547A1 (en) 2018-05-31 2019-05-23 Brake control device and method for detecting malfunction in brake control device

Country Status (2)

Country Link
JP (1) JP2019209707A (en)
WO (1) WO2019230547A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021208235A1 (en) * 2020-04-16 2021-10-21 新石器慧通（北京）科技有限公司 Unmanned means of transport, and safety checking method for brake system thereof

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008230355A (en) * 2007-03-19 2008-10-02 Hitachi Ltd Brake control device and pumping-up system
JP2014151806A (en) * 2013-02-12 2014-08-25 Hitachi Automotive Systems Ltd Brake system
JP2018001973A (en) * 2016-07-01 2018-01-11 日立オートモティブシステムズ株式会社 Brake device and liquid leakage detection method of brake device

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008230355A (en) * 2007-03-19 2008-10-02 Hitachi Ltd Brake control device and pumping-up system
JP2014151806A (en) * 2013-02-12 2014-08-25 Hitachi Automotive Systems Ltd Brake system
JP2018001973A (en) * 2016-07-01 2018-01-11 日立オートモティブシステムズ株式会社 Brake device and liquid leakage detection method of brake device

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021208235A1 (en) * 2020-04-16 2021-10-21 新石器慧通（北京）科技有限公司 Unmanned means of transport, and safety checking method for brake system thereof

Also Published As

Publication number Publication date
JP2019209707A (en) 2019-12-12

Similar Documents

Publication Publication Date Title
WO2018003539A1 (en) Brake device and method for detecting fluid leakage in brake device
KR101973892B1 (en) Brake device
US9522668B2 (en) Brake apparatus
JP6678996B2 (en) Hydraulic control device and brake system
JP7132838B2 (en) Automotive Pedal Stroke Detector and Automotive Control Unit
WO2013150631A1 (en) Vehicle brake device
WO2017006631A1 (en) Brake control device and braking system
WO2017068968A1 (en) Brake control device
WO2019146404A1 (en) Brake control device and failure detection method for brake control device
WO2019230547A1 (en) Brake control device and method for detecting malfunction in brake control device
JP2019085028A (en) Brake control device, brake control method, and brake system
JP2020093656A (en) Brake control device and method for detecting failure of brake control device
CN114423652B (en) Brake device for vehicle
JP2016020101A (en) Driving circuit of brake device
JP6898884B2 (en) Brake control device and abnormality detection method for brake control device
JP2018176757A (en) Brake device, brake system and method for controlling brake device
JP5977691B2 (en) Brake control device
JP2018043613A (en) Brake control device and method for controlling brake device
JP5898592B2 (en) Brake device
JP2022099361A (en) Vehicular braking device and electric cylinder
JP2018058540A (en) Brake device and control method of brake device
JP2020090144A (en) Brake control device
JP2019014476A (en) Brake system

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 19812279

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 19812279

Country of ref document: EP

Kind code of ref document: A1