JP5556245B2 - Brake control device - Google Patents

Description

  The present invention relates to a brake control device that controls braking force applied to wheels provided in a vehicle.

  Patent Document 1 describes a braking control device for an electric vehicle that shifts down after a regenerative braking force is set to zero when a driver performs a shift lever operation. In this apparatus, a friction braking force corresponding to the difference between the required braking force required for the vehicle and the regenerative braking force is applied to the vehicle. Patent Document 2 describes a regenerative braking device for an electric vehicle that controls a regenerative braking force in accordance with a driving situation of a vehicle and a road condition ahead.

JP-A-11-27802 Japanese Patent Laid-Open No. 10-201008

  By the way, when a shift change is performed during regenerative braking, the regenerative braking force may be momentarily reduced. In this case, it is conceivable to compensate the decrease in the regenerative braking force with the friction braking force. However, since the friction braking force is generally operated with hydraulic pressure and is inferior in response, the instantaneous decrease in the regenerative braking force with respect to the required braking force is reduced. It is not always easy to compensate completely with the hydraulic braking force. In extreme cases, the increase in regenerative braking force from the momentary drop to the original state overlaps with the increase in hydraulic braking force that should have compensated for the momentary drop, resulting in brake feeling. An impact may also occur.

  In view of the above, an object of the present invention is to provide a brake control device that can reduce the influence on brake feeling caused by a shift during regenerative braking.

  A brake control device according to an aspect of the present invention includes an electric motor connected to a wheel via a speed change mechanism, a regenerative brake unit that applies a regenerative braking force to the wheel by regeneration of the electric motor, and a friction control to the wheel. And a control unit that controls the regenerative brake unit and the friction brake unit so as to generate the required braking force by using the regenerative braking force and the friction braking force in combination. The control unit suppresses a variation in friction braking force when a shift is detected or predicted.

  According to this aspect, since the variation of the friction braking force is suppressed when the shift is detected or predicted, the influence on the brake feeling can be reduced.

  The control unit may keep the friction braking force constant when a shift operation by the driver is detected or predicted. Here, the control unit may keep the actual value of the friction braking force constant, or may hold the friction braking force by keeping the target value of the friction braking force constant.

  The control unit may keep the friction braking force constant for at least the shift operation time when the shift operation by the driver is detected or predicted.

  The control unit may suppress a variation in the friction braking force when an appropriate amount of the regenerative braking force that can be generated is limited to a request from the vehicle drive system.

  Another aspect of the present invention is also a brake control device. This device includes a regenerative braking unit that applies a regenerative braking force to a wheel by regenerating a motor for driving the wheel, a friction brake unit that applies a friction braking force to the wheel, a regenerative braking force and a friction braking force, And a controller that controls the regenerative brake unit and the friction brake unit to generate the required braking force. The control unit suppresses fluctuations in the frictional braking force when it detects or predicts that the amount of the regenerative braking force that can be applied to the required braking force decreases at a reduction rate that exceeds the reference.

  According to this aspect, it is possible to reduce the influence on the brake feeling due to the difference in response between the regenerative braking force and the friction braking force. For example, when a sudden change in the regenerative braking force due to a shift is detected or predicted, the variation in the friction braking force is suppressed, so that the influence on the brake feeling can be reduced.

  According to the present invention, the brake feeling during shifting is improved.

1 is a schematic configuration diagram illustrating a vehicle to which a brake control device according to an embodiment of the present invention is applied. It is a systematic diagram showing a hydraulic brake unit concerning one embodiment of the present invention. It is a flowchart for demonstrating an example of the regeneration cooperation control process which concerns on one Embodiment of this invention. It is a flowchart for demonstrating the switching process of the brake control mode which concerns on one Embodiment of this invention. It is a figure which shows an example of the time change of the regenerative braking force and hydraulic braking force which concern on one Embodiment of this invention. It is a figure which shows an example of the time change of regenerative braking force and hydraulic braking force. It is a figure which shows an example of the time change of the regenerative braking force and hydraulic braking force which concern on one Embodiment of this invention.

  The brake control device according to an embodiment of the present invention is suitable when a large fluctuation (in other words, a high-frequency fluctuation) is assumed to occur instantaneously in the regenerative braking force. For example, there is a brake control system that limits or stops regenerative braking when the shift position is neutral. Normally, it goes through neutral for a moment during a shift change. Therefore, when the driver performs a shift operation, a large fluctuation occurs instantaneously in the regenerative braking force. The brake control device temporarily suppresses fluctuations in the friction braking force, for example, when a shift is detected or predicted. In this way, it is possible to reduce the influence on the brake feeling due to the difference in response between the regenerative braking force and the friction braking force. In particular, it is possible to reduce a sense of incongruity due to the overlap between the recovery from the instantaneous decrease of the regenerative braking force and the compensation by the frictional braking force, thereby improving the brake feeling.

  In addition, the brake control device according to an embodiment of the present invention is also suitable when it is assumed that a high-frequency fluctuation occurs in the regenerative braking force due to a request from another control system in the vehicle. For example, this is a case where the regenerative braking force is limited by a request from the drive control system of the vehicle. In one embodiment, the drive control system of the vehicle gives a request for limiting the regenerative braking force to the brake control device when a shift is detected. The drive control system can use the margin of the regenerative braking force obtained by imposing this restriction in order to compensate for an instantaneous decrease in engine brake accompanying a shift. The brake control device temporarily suppresses fluctuations in the friction braking force, for example, when a shift is detected or predicted.

  In this way, since the reduction due to the shift of the deceleration by the engine brake is compensated by the regenerative braking force, the influence on the brake feeling can be reduced. Furthermore, it is possible to reduce the influence on the brake feeling due to the overlap between the release of the restriction of the regenerative braking force accompanying the end of the shift operation and the response delay of the friction braking force with respect to the regenerative braking force. Therefore, the influence on the brake feeling due to the shift is reduced.

  Further, the frequency of operation of the friction brake unit for generating the friction braking force can be reduced by suppressing the fluctuation of the friction braking force. For this reason, the service life of the friction brake unit can be extended. For example, since the frequency of opening and closing the hydraulic control valve for operating the friction member by hydraulic pressure can be reduced, deterioration of the sealing performance of the control valve can be suppressed. Since the drag of the wheel cylinder pressure due to the deterioration of the sealability can be suppressed, the practical fuel consumption can be improved in the long run. By suppressing the deterioration of the sealing property, erroneous detection of abnormality in the hydraulic pressure control system can also be suppressed.

  In one embodiment, the brake control device may temporarily suppress fluctuations in the friction braking force when a driver shift operation is detected or predicted. A so-called sequential shiftmatic is known in which downshifting and upshifting operations by a driver's operation are allowed. In the sequential shiftmatic mode, the frequency of shifting is expected to increase compared to the normal automatic mode. Therefore, in a preferred embodiment, the brake control device temporarily performs the fluctuation of the friction braking force when the shift operation is detected or predicted when the brake regeneration cooperative control is executed in the sequential shiftmatic mode. It may be suppressed.

  Further, the brake control device may temporarily suppress the variation of the friction braking force when a shift switching operation between the so-called D range and B range is detected. The D range is a recommended shift position in normal driving, and the B range is a shift position to be selected when the driver needs engine brake (including regenerative braking) stronger than normal driving. In addition, the brake control device may determine whether or not the driving situation is highly likely to perform the shift switching operation, and may temporarily suppress the variation of the friction braking force in the case of an affirmative determination. For example, the brake control device may determine whether or not there is a driving situation in which there is a high possibility that a shift-down operation from the D range to the B range is performed based on information about the traveling road ahead. The brake control device may determine whether or not there is a downhill, an uphill, or a curve on the forward travel path based on information from the vehicle navigation system. Information from an angle sensor for outputting information indicating the direction of the vehicle may be used instead of or together with information from the navigation system.

  In one embodiment, the brake control device may execute the friction braking force fluctuation suppression control for at least the shift operation time when a shift operation by the driver is detected during execution of the brake regeneration cooperative control. The shift operation time is, for example, a required time from the detection of the operation input by the driver until the shift change is completed. The shift operation time preferably includes at least a time during which power transmission from the vehicle drive source to the wheels is interrupted by the speed change operation. The variation suppression control of the friction braking force may be control that keeps the friction braking force constant. Here, keeping the friction braking force constant is a concept including keeping the target value of the friction braking force constant.

  The brake control device may include a regenerative brake unit that applies a regenerative braking force to the wheel by regenerating a motor for driving the wheel. The motor may be connected to the wheels via a reduction mechanism having a constant reduction ratio. The regenerative brake unit may include a motor control unit for controlling the motor and / or a drive control unit for controlling the drive system of the vehicle. The control unit of the regenerative brake unit and the control unit of the brake control device may be connected so as to communicate with each other. For example, it may be communicatively connected through an in-vehicle network or may be communicably connected via a host controller.

  The brake control device may include a friction brake unit that applies friction braking force to the wheels. The friction brake unit includes a friction member that applies a friction braking force to each wheel, a wheel cylinder that presses the friction member against the wheel by the action of hydraulic pressure, and an actuator that controls the hydraulic pressure applied to each wheel cylinder. May be. The response delay of the friction braking force increases as the hydraulic pressure control volume increases. Therefore, in a preferred embodiment, the actuator may include a common control valve for controlling the hydraulic pressure applied to each wheel cylinder. When the friction braking force fluctuation suppression control is applied to a brake system including such a hydraulic circuit, the effect of improving the brake feeling can be further increased.

  The suppression of the fluctuation of the friction braking force by the brake control device may not be triggered by the detection or prediction of the shift. In one embodiment, the brake control device temporarily suppresses fluctuations in the friction braking force when it detects or predicts that the reproducible braking force can be applied to the required braking force at a decreasing rate exceeding a reference. You may make it do. The reference value for the reduction speed is preferably set based on the response of the friction brake unit. Alternatively, the brake control device may temporarily suppress fluctuations in the friction braking force when the appropriation to the required braking force among the regenerative braking force that can be generated is limited by a request from the drive system of the vehicle. Good. In this way, when the regenerative braking force is subject to high-frequency fluctuations exceeding the standard, the friction braking force fluctuations are suppressed, so that the difference in response between the regenerative braking force and the friction braking force affects the brake feeling. Can be reduced. Further, the service life of the friction brake unit can be extended.

  On the other hand, in one embodiment, the brake control device may not apply the friction braking force fluctuation suppression even when a high frequency fluctuation of the regenerative braking force is detected or predicted. For example, in a situation where securing sufficient braking force is more important than improving brake feeling, fluctuations in friction braking force may be allowed. The brake control device may allow the variation of the frictional braking force in the same way as usual during the execution of the control for stabilizing the behavior of the vehicle such as ABS control, or when the control system is abnormal such as communication abnormality. .

  In one embodiment, a vehicle control device is provided in which motor torque is transmitted to wheels via a transmission. The control device includes a target value setting unit configured to set a target value of the regenerative braking force by the motor and a target value of the friction braking force by pressurizing the friction member based on an operation amount of the braking operation member by the driver; And braking means for applying a regenerative braking force and a frictional braking force to the vehicle in accordance with each set target value. The control device may further include shift change detection means for detecting the presence or absence of a shift change, and may suppress a change in the target value of the friction braking force when the shift change is detected. Instead of the target value, a change in a command value (for example, a control current of the control valve) for realizing the target value may be suppressed. In this way, a temporary increase in braking force due to shift change can be suppressed.

  The shift change detecting means or the brake control unit may directly detect the operation of the driver by the driver, or may detect the shift operation by detecting a change in the operating state of the drive source due to the shift operation. You may detect indirectly. The shift change detection means or the brake control unit may determine whether or not the shift operation is highly likely to be performed. The shift change detection means or the brake control unit may detect that there is a shift change when it is determined that the possibility of a shift operation is high.

  FIG. 1 is a schematic configuration diagram illustrating a vehicle to which a brake control device according to an embodiment of the present invention is applied. The vehicle 1 shown in the figure is configured as a so-called hybrid vehicle. The vehicle 1 has an engine and a motor as drive sources, and power is transmitted from the drive sources to the wheels via a speed change mechanism. The vehicle 1 includes an engine 2, a three-shaft power split mechanism 3 connected to a crankshaft that is an output shaft of the engine 2, a motor generator 4 capable of generating power connected to the power split mechanism 3, and a transmission 5. The electric motor 6 connected to the power split mechanism 3 through the hybrid electronic control unit (hereinafter referred to as “hybrid ECU”) that controls the entire drive system of the vehicle 1. 7). A right front wheel 9FR and a left front wheel 9FL, which are drive wheels of the vehicle 1, are connected to the transmission 5 via a drive shaft 8.

  The engine 2 is an internal combustion engine that is operated using a hydrocarbon-based fuel such as gasoline or light oil, and is controlled by the engine ECU 13. The engine ECU 13 can communicate with the hybrid ECU 7, and performs fuel injection control, ignition control, intake control, etc. of the engine 2 based on control signals from the hybrid ECU 7 and signals from various sensors that detect the operating state of the engine 2. Run. Further, the engine ECU 13 gives information regarding the operating state of the engine 2 to the hybrid ECU 7 as necessary.

  The power split mechanism 3 transmits the output of the electric motor 6 to the left and right front wheels 9FR, 9FL via the transmission 5, distributes the output of the engine 2 to the motor generator 4 and the transmission 5, and the electric motor. 6 and the speed of the engine 2 is reduced or increased. By changing the rotation speed of the engine 2 and the rotation speed of the motor generator 4, the power split mechanism 3 also functions as a continuously variable transmission.

  The motor generator 4 and the electric motor 6 are each connected to a battery 12 via a power converter 11 including an inverter, and a motor ECU 14 is connected to the power converter 11. As the battery 12, for example, a storage battery such as a nickel hydride storage battery can be used. The motor ECU 14 can also communicate with the hybrid ECU 7 and controls the motor generator 4 and the electric motor 6 via the power converter 11 based on a control signal from the hybrid ECU 7 or the like. The hybrid ECU 7, engine ECU 13, and motor ECU 14 described above are all configured as a microprocessor including a CPU. In addition to the CPU, a ROM that stores various programs, a RAM that temporarily stores data, and an input / output port And a communication port.

  The left and right front wheels 9FR and 9FL can be driven by the output of the electric motor 6 by supplying electric power from the battery 12 to the electric motor 6 via the power converter 11 under the control of the hybrid ECU 7 and the motor ECU 14. . Further, the vehicle 1 is driven by the engine 2 in a driving region where the engine efficiency is good. At this time, by transmitting a part of the output of the engine 2 to the motor generator 4 via the power split mechanism 3, the electric motor 6 is driven using the electric power generated by the motor generator 4 or the power conversion device 11 is operated. It is possible to charge the battery 12.

  When the vehicle 1 is braked, the electric motor 6 is rotated by the power transmitted from the front wheels 9FR and 9FL under the control of the hybrid ECU 7 and the motor ECU 14, and the electric motor 6 is operated as a generator. That is, the electric motor 6, the power converter 11, the hybrid ECU 7, the motor ECU 14, and the like function as a regenerative brake unit 10 that applies braking force to the left and right front wheels 9FR, 9FL by regenerating the kinetic energy of the vehicle 1 into electric energy. To do. In one embodiment, the regenerative brake unit 10 is configured to apply a regenerative braking force to the wheels by the regeneration of the motor 6 and compensate for a decrease in engine brake accompanying a shift with the regenerative braking force.

  In addition to the regenerative brake unit 10, the vehicle 1 includes a hydraulic brake unit 20 that generates a braking force by supplying hydraulic fluid from a power hydraulic pressure source 30 or the like, as shown in FIG. 2. The vehicle braking device of the present embodiment is capable of braking the vehicle 1 by executing brake regeneration cooperative control in which the regenerative brake unit 10 and the hydraulic brake unit 20 are coordinated. The vehicle 1 in the present embodiment can generate a desired braking force by using the regenerative braking force and the hydraulic braking force together by executing the brake regeneration cooperative control.

  FIG. 2 is a system diagram showing the hydraulic brake unit 20 according to the present embodiment. As shown in FIG. 2, the hydraulic brake unit 20 includes disc brake units 21FR, 21FL, 21RR and 21RL provided for each wheel, a master cylinder unit 27, a power hydraulic pressure source 30, a hydraulic brake unit 20 Pressure actuator 40.

  Disc brake units 21FR, 21FL, 21RR, and 21RL apply braking force to the right front wheel, the left front wheel, the right rear wheel, and the left rear wheel of the vehicle, respectively. The master cylinder unit 27 as the manual hydraulic pressure source in the present embodiment sends the brake fluid pressurized according to the operation amount by the driver of the brake pedal 24 as the brake operation member to the disc brake units 21FR to 21RL. To do. The power hydraulic pressure source 30 can send the brake fluid as the working fluid pressurized by the power supply to the disc brake units 21FR to 21RL independently of the brake pedal operation. The hydraulic actuator 40 appropriately adjusts the hydraulic pressure of the brake fluid supplied from the power hydraulic pressure source 30 or the master cylinder unit 27 and sends it to the disc brake units 21FR to 21RL. Thereby, the braking force with respect to each wheel by hydraulic braking is adjusted.

  Each of the disc brake units 21FR to 21RL, the master cylinder unit 27, the power hydraulic pressure source 30, and the hydraulic actuator 40 will be described in more detail below. Each of the disc brake units 21FR to 21RL includes a brake disc 22 and wheel cylinders 23FR to 23RL incorporated in the brake caliper, respectively. The wheel cylinders 23FR to 23RL are connected to the hydraulic actuator 40 via different fluid passages. Hereinafter, the wheel cylinders 23FR to 23RL are collectively referred to as “wheel cylinders 23” as appropriate.

  In the disc brake units 21FR to 21RL, when brake fluid is supplied to the wheel cylinder 23 from the hydraulic actuator 40, a brake pad as a friction member is pressed against the brake disc 22 that rotates together with the wheel. Thereby, a braking force is applied to each wheel. In the present embodiment, the disc brake units 21FR to 21RL are used, but other braking force applying mechanisms including a wheel cylinder 23 such as a drum brake may be used.

  In this embodiment, the master cylinder unit 27 is a master cylinder with a hydraulic booster, and includes a hydraulic booster 31, a master cylinder 32, a regulator 33, and a reservoir. The hydraulic booster 31 is connected to the brake pedal 24, amplifies the pedal effort applied to the brake pedal 24, and transmits it to the master cylinder 32. When the brake fluid is supplied from the power hydraulic pressure source 30 to the hydraulic pressure booster 31 via the regulator 33, the pedal effort is amplified. The master cylinder 32 generates a master cylinder pressure having a predetermined boost ratio with respect to the pedal effort.

  A reservoir 34 for storing brake fluid is disposed above the master cylinder 32 and the regulator 33. The master cylinder 32 communicates with the reservoir 34 when the depression of the brake pedal 24 is released. On the other hand, the regulator 33 is in communication with both the reservoir 34 and the accumulator 35 of the power hydraulic pressure source 30, and the reservoir 34 is used as a low pressure source, the accumulator 35 is used as a high pressure source, and the hydraulic pressure is approximately equal to the master cylinder pressure. Is generated. Hereinafter, the hydraulic pressure in the regulator 33 is appropriately referred to as “regulator pressure”. The master cylinder pressure and the regulator pressure do not need to be exactly the same pressure. For example, the master cylinder unit 27 can be designed so that the regulator pressure is slightly higher.

  The power hydraulic pressure source 30 includes an accumulator 35 and a pump 36. The accumulator 35 converts the pressure energy of the brake fluid boosted by the pump 36 into the pressure energy of an enclosed gas such as nitrogen, for example, about 14 to 22 MPa and stores it. The pump 36 has a motor 36 a as a drive source, and its suction port is connected to the reservoir 34, while its discharge port is connected to the accumulator 35. The accumulator 35 is also connected to a relief valve 35 a provided in the master cylinder unit 27. When the pressure of the brake fluid in the accumulator 35 increases abnormally to about 25 MPa, for example, the relief valve 35 a is opened, and the high-pressure brake fluid is returned to the reservoir 34.

  As described above, the hydraulic brake unit 20 includes the master cylinder 32, the regulator 33, and the accumulator 35 as a supply source of brake fluid to the wheel cylinder 23. A master pipe 37 is connected to the master cylinder 32, a regulator pipe 38 is connected to the regulator 33, and an accumulator pipe 39 is connected to the accumulator 35. These master pipe 37, regulator pipe 38 and accumulator pipe 39 are each connected to a hydraulic actuator 40.

  The hydraulic actuator 40 includes an actuator block in which a plurality of flow paths are formed, and a plurality of electromagnetic control valves. The flow paths formed in the actuator block include individual flow paths 41, 42, 43 and 44 and a main flow path 45. The individual flow paths 41 to 44 are respectively branched from the main flow path 45 and connected to the wheel cylinders 23FR, 23FL, 23RR, 23RL of the corresponding disc brake units 21FR, 21FL, 21RR, 21RL. Thereby, each wheel cylinder 23 can communicate with the main flow path 45.

  In addition, ABS holding valves 51, 52, 53 and 54 are provided in the middle of the individual flow paths 41, 42, 43 and 44. Each of the ABS holding valves 51 to 54 has a solenoid and a spring that are ON / OFF controlled, and both are normally open electromagnetic control valves that are opened when the solenoid is in a non-energized state. Each of the ABS holding valves 51 to 54 in the opened state can distribute the brake fluid in both directions. That is, the brake fluid can flow from the main flow path 45 to the wheel cylinder 23, and conversely, the brake fluid can also flow from the wheel cylinder 23 to the main flow path 45. When the solenoid is energized and the ABS holding valves 51 to 54 are closed, the flow of brake fluid in the individual flow paths 41 to 44 is blocked.

  Further, the wheel cylinder 23 is connected to the reservoir channel 55 via pressure reducing channels 46, 47, 48 and 49 connected to the individual channels 41 to 44, respectively. ABS decompression valves 56, 57, 58 and 59 are provided in the middle of the decompression channels 46, 47, 48 and 49. Each of the ABS pressure reducing valves 56 to 59 has a solenoid and a spring that are ON / OFF controlled, and is a normally closed electromagnetic control valve that is closed when the solenoid is in a non-energized state. When the ABS pressure reducing valves 56 to 59 are closed, the flow of brake fluid in the pressure reducing flow paths 46 to 49 is blocked. When the solenoid is energized and the ABS pressure reducing valves 56 to 59 are opened, the brake fluid is allowed to flow through the pressure reducing flow paths 46 to 49, and the brake fluid flows from the wheel cylinder 23 to the pressure reducing flow paths 46 to 49 and It returns to the reservoir 34 via the reservoir channel 55. The reservoir channel 55 is connected to the reservoir 34 of the master cylinder unit 27 via a reservoir pipe 77.

  The main channel 45 has a separation valve 60 in the middle. By this separation valve 60, the main channel 45 is divided into a first channel 45 a connected to the individual channels 41 and 42 and a second channel 45 b connected to the individual channels 43 and 44. The first flow path 45a is connected to the front wheel wheel cylinders 23FR and 23FL via the individual flow paths 41 and 42, and the second flow path 45b is connected to the rear wheel wheel cylinder via the individual flow paths 43 and 44. Connected to 23RR and 23RL.

  The separation valve 60 has a solenoid and a spring that are ON / OFF controlled, and is a normally closed electromagnetic control valve that is closed when the solenoid is in a non-energized state. When the separation valve 60 is in the closed state, the flow of brake fluid in the main flow path 45 is blocked. When the solenoid is energized and the separation valve 60 is opened, the brake fluid can be circulated bidirectionally between the first flow path 45a and the second flow path 45b.

  In the hydraulic actuator 40, a master channel 61 and a regulator channel 62 communicating with the main channel 45 are formed. More specifically, the master channel 61 is connected to the first channel 45 a of the main channel 45, and the regulator channel 62 is connected to the second channel 45 b of the main channel 45. The master channel 61 is connected to a master pipe 37 that communicates with the master cylinder 32. The regulator channel 62 is connected to a regulator pipe 38 that communicates with the regulator 33.

  The master channel 61 has a master cut valve 64 in the middle. The master cut valve 64 is provided on the brake fluid supply path from the master cylinder 32 to each wheel cylinder 23. The master cut valve 64 has a solenoid and a spring that are ON / OFF-controlled, and the valve closing state is guaranteed by the electromagnetic force generated by the solenoid when supplied with a prescribed control current, so that the solenoid is in a non-energized state. It is a normally open electromagnetic control valve that is opened in some cases. The master cut valve 64 in the opened state can cause the brake fluid to flow in both directions between the master cylinder 32 and the first flow path 45 a of the main flow path 45. When a prescribed control current is applied to the solenoid and the master cut valve 64 is closed, the flow of brake fluid in the master flow path 61 is interrupted.

  A stroke simulator 69 is connected to the master channel 61 via a simulator cut valve 68 on the upstream side of the master cut valve 64. That is, the simulator cut valve 68 is provided in a flow path connecting the master cylinder 32 and the stroke simulator 69. The simulator cut valve 68 has a solenoid and a spring that are ON / OFF controlled, and the valve opening state is guaranteed by the electromagnetic force generated by the solenoid upon receipt of a specified control current, and the solenoid is in a non-energized state. It is a normally closed electromagnetic control valve that is closed in some cases. When the simulator cut valve 68 is closed, the flow of brake fluid between the master flow path 61 and the stroke simulator 69 is blocked. When the solenoid is energized and the simulator cut valve 68 is opened, the brake fluid can be circulated bidirectionally between the master cylinder 32 and the stroke simulator 69.

  The stroke simulator 69 includes a plurality of pistons and springs, and creates a reaction force corresponding to the depression force of the brake pedal 24 by the driver when the simulator cut valve 68 is opened. As the stroke simulator 69, in order to improve the feeling of brake operation by the driver, it is preferable to employ one having a multistage spring characteristic.

  The regulator flow path 62 has a regulator cut valve 65 in the middle. The regulator cut valve 65 is provided on the brake fluid supply path from the regulator 33 to each wheel cylinder 23. The regulator cut valve 65 also has a solenoid and a spring that are ON / OFF controlled, and the valve closing state is guaranteed by the electromagnetic force generated by the solenoid upon receipt of a specified control current, and the solenoid is in a non-energized state. It is a normally open electromagnetic control valve that is opened in some cases. The regulator cut valve 65 that has been opened can cause the brake fluid to flow in both directions between the regulator 33 and the second flow path 45 b of the main flow path 45. When the solenoid is energized and the regulator cut valve 65 is closed, the flow of brake fluid in the regulator flow path 62 is blocked.

  In the hydraulic actuator 40, an accumulator channel 63 is also formed in addition to the master channel 61 and the regulator channel 62. One end of the accumulator channel 63 is connected to the second channel 45 b of the main channel 45, and the other end is connected to an accumulator pipe 39 that communicates with the accumulator 35.

  The accumulator flow path 63 has a pressure-increasing linear control valve 66 in the middle. Further, the accumulator channel 63 and the second channel 45 b of the main channel 45 are connected to the reservoir channel 55 via the pressure-reducing linear control valve 67. The pressure-increasing linear control valve 66 and the pressure-decreasing linear control valve 67 each have a linear solenoid and a spring, and both are normally closed electromagnetic control valves that are closed when the solenoid is in a non-energized state. In the pressure-increasing linear control valve 66 and the pressure-decreasing linear control valve 67, the opening degree of the valve is adjusted in proportion to the current supplied to each solenoid.

  The pressure-increasing linear control valve 66 is provided as a common pressure-increasing control valve for each of the wheel cylinders 23 provided corresponding to each wheel. Similarly, the pressure-reducing linear control valve 67 is provided as a pressure-reducing control valve common to the wheel cylinders 23. That is, in this embodiment, the pressure-increasing linear control valve 66 and the pressure-reducing linear control valve 67 are a pair of common control valves that control the supply and discharge of the working fluid sent from the power hydraulic pressure source 30 to each wheel cylinder 23. It is provided as. Thus, if the pressure-increasing linear control valve 66 and the pressure-decreasing linear control valve 67 are made common to each wheel cylinder 23, it is preferable from the viewpoint of cost as compared with the case where a linear control valve is provided for each wheel cylinder 23.

  Here, the differential pressure between the inlet and outlet of the pressure-increasing linear control valve 66 corresponds to the differential pressure between the pressure of the brake fluid in the accumulator 35 and the pressure of the brake fluid in the main flow path 45, and the inlet / outlet of the pressure-reducing linear control valve 67. The pressure difference therebetween corresponds to the pressure difference between the brake fluid pressure in the main flow path 45 and the brake fluid pressure in the reservoir 34. Further, the electromagnetic driving force according to the power supplied to the linear solenoid of the pressure increasing linear control valve 66 and the pressure reducing linear control valve 67 is F1, the spring biasing force is F2, and the pressure increasing linear control valve 66 and the pressure reducing linear control valve are Assuming that the differential pressure acting force according to the differential pressure between the inlet / outlet of 67 is F3, the relationship F1 + F3 = F2 is established. Therefore, the differential pressure between the inlet and outlet of the pressure-increasing linear control valve 66 and the pressure-reducing linear control valve 67 is controlled by continuously controlling the power supplied to the linear solenoids of the pressure-increasing linear control valve 66 and the pressure-reducing linear control valve 67. can do.

  In the hydraulic brake unit 20, the power hydraulic pressure source 30 and the hydraulic actuator 40 are controlled by a brake ECU 70 as a control unit in the present embodiment. The brake ECU 70 is configured as a microprocessor including a CPU, and includes a ROM that stores various programs, a RAM that temporarily stores data, an input / output port, a communication port, and the like in addition to the CPU. The brake ECU 70 can communicate with the host hybrid ECU 7 and the like, and configures the pump 36 of the power hydraulic pressure source 30 and the hydraulic actuator 40 based on control signals from the hybrid ECU 7 and signals from various sensors. The electromagnetic control valves 51 to 54, 56 to 59, 60, and 64 to 68 are controlled.

  Further, a regulator pressure sensor 71, an accumulator pressure sensor 72, and a control pressure sensor 73 are connected to the brake ECU 70. The regulator pressure sensor 71 detects the pressure of the brake fluid in the regulator flow path 62 on the upstream side of the regulator cut valve 65, that is, the regulator pressure, and gives a signal indicating the detected value to the brake ECU 70. The accumulator pressure sensor 72 detects the pressure of the brake fluid in the accumulator flow path 63, that is, the accumulator pressure on the upstream side of the pressure increasing linear control valve 66, and gives a signal indicating the detected value to the brake ECU 70. The control pressure sensor 73 detects the pressure of the brake fluid in the first flow path 45a of the main flow path 45, and gives a signal indicating the detected value to the brake ECU 70. The detection values of the pressure sensors 71 to 73 are sequentially given to the brake ECU 70 every predetermined time, and are stored and held in a predetermined storage area of the brake ECU 70.

  When the separation valve 60 is opened and the first flow path 45 a and the second flow path 45 b of the main flow path 45 communicate with each other, the output value of the control pressure sensor 73 is the low pressure of the pressure-increasing linear control valve 66. This indicates the hydraulic pressure on the high pressure side of the pressure-reducing linear control valve 67 and the output value can be used to control the pressure-increasing linear control valve 66 and the pressure-reducing linear control valve 67. When the pressure-increasing linear control valve 66 and the pressure-decreasing linear control valve 67 are closed and the master cut valve 64 is opened, the output value of the control pressure sensor 73 indicates the master cylinder pressure. Further, the separation valve 60 is opened so that the first flow path 45a and the second flow path 45b of the main flow path 45 communicate with each other, and the ABS holding valves 51 to 54 are opened, while the ABS pressure reducing valves 56 are opened. When? 59 is closed, the output value of the control pressure sensor 73 indicates the working fluid pressure acting on each wheel cylinder 23, i.e., the wheel cylinder pressure.

  Further, the sensor connected to the brake ECU 70 includes a stroke sensor 25 provided on the brake pedal 24. The stroke sensor 25 detects a pedal stroke as an operation amount of the brake pedal 24 and gives a signal indicating the detected value to the brake ECU 70. The output value of the stroke sensor 25 is also sequentially given to the brake ECU 70 every predetermined time, and is stored and held in a predetermined storage area of the brake ECU 70. A brake operation state detection unit other than the stroke sensor 25 may be provided in addition to the stroke sensor 25 or in place of the stroke sensor 25 and connected to the brake ECU 70. Examples of the brake operation state detection means include a pedal depression force sensor that detects an operation force of the brake pedal 24 and a brake switch that detects that the brake pedal 24 is depressed.

  Note that the brake ECU 70 may be provided with shift information indicating the presence or absence of a shift operation by the driver and shift information indicating the presence or absence of a shift at predetermined intervals. Further, sensing information from a shift operation sensing system (not shown) attached to the shift knob of the shift lever may be given to the brake ECU 70 every predetermined time and stored. For example, the shift operation sensing system may include a temperature sensor that measures the temperature of the shift knob or a pressure sensor that measures the pressure on the surface of the shift knob, and may be configured to output the output of these sensors to the brake ECU 70.

  The brake control device according to the present embodiment including the hydraulic brake unit 20 configured as described above can execute brake regeneration cooperative control. In one embodiment, the brake ECU 70 calculates a required braking force based on a driver's brake operation, and calculates a required regenerative braking force based on the required braking force. The brake ECU 70 transmits the requested regenerative braking force to the hybrid ECU 7. The hybrid ECU 7 controls the regenerative braking unit 10 according to the received required regenerative braking force to generate the regenerative braking force, and transmits the actually generated regenerative braking force effective value to the brake ECU 70. The brake ECU 70 calculates a required friction braking force based on the required braking force and the regenerative braking force effective value, and controls the friction brake unit, that is, the hydraulic brake unit 20 in accordance with the required friction braking force.

  FIG. 3 is a flowchart for explaining an example of the regeneration cooperative control process. In response to the braking request, the brake ECU 70 starts processing. The braking request is generated when a braking force should be applied to the vehicle, for example, when the driver operates the brake pedal 24. The brake ECU 70 is repeatedly executed at a predetermined control cycle until, for example, the operation of the brake pedal 24 is released. The brake ECU 70 executes the process shown in FIG. 3 on the assumption that the conditions for permitting the regenerative cooperative control are satisfied. For example, when the shift position is neutral, at the time of a predetermined low speed assumed to be when the vehicle is stopped or immediately before the vehicle is stopped, it is determined that the permission condition for the regenerative cooperative control is not satisfied, and the vehicle is braked by the friction braking force.

  As shown in FIG. 3, in response to a braking request, the brake ECU 70 calculates a target deceleration, that is, a required braking force (S10). For example, the brake ECU 70 calculates a target deceleration based on the measured values of the master cylinder pressure and the stroke. Here, the brake ECU 70 calculates the target braking force of each wheel by distributing the target deceleration to each wheel according to the desired braking force distribution, and in the subsequent processing, the regenerative braking force and the hydraulic braking force are based on the target braking force. May be controlled.

  The brake ECU 70 calculates the required regenerative braking force based on the target deceleration (S12). For example, the brake ECU 70 sets the target deceleration as the required regenerative braking force when the target deceleration is smaller than the maximum regenerative braking force that can be generated, and the maximum regenerative braking force when the target deceleration is equal to or greater than the maximum regenerative braking force. Is the required regenerative braking force. Further, the brake ECU 70 may calculate the required regenerative braking force by correcting the target deceleration instead of using the target deceleration as it is as the required regenerative braking force. The required regenerative braking force may be corrected to be higher with respect to the target deceleration, or may be corrected to be lower. For example, when the regeneration decrease notice signal is received, the brake ECU 70 may perform correction so as to limit the required regenerative braking force. The brake ECU 70 transmits the calculated required regenerative braking force to the hybrid ECU 7 (S14). The brake ECU 70 and the hybrid ECU 7 are connected to the in-vehicle network. The brake ECU 70 transmits the requested regenerative braking force to the in-vehicle network.

  The hybrid ECU 7 receives the requested regenerative braking force from the in-vehicle network. The hybrid ECU 7 controls the regenerative brake unit 10 with the received regenerative braking force received as the regenerative braking force target value. As a result, the hybrid ECU 7 transmits the effective value of the regenerative braking force actually generated to the brake ECU 70 through the in-vehicle network. When a part of the regenerative braking force is used for simulating the engine brake, the hybrid ECU 7 sets the remainder obtained by subtracting the portion allocated to the engine brake from the actually generated regenerative braking force to the brake ECU 70 as an effective value. Send. Further, the hybrid ECU 7 may transmit a regeneration decrease notice signal to the brake ECU 70 based on the state of charge of the battery 12.

  The brake ECU 70 receives the regenerative braking force effective value from the hybrid ECU 7 (S16). The brake ECU 70 calculates a required hydraulic braking force that is a braking force to be generated by the hydraulic brake unit 20 by subtracting the regenerative braking force effective value from the target deceleration (S18). The brake ECU 70 calculates the target hydraulic pressure of each wheel cylinder 23FR to 23RL based on the required hydraulic braking force. The brake ECU 70 may correct the required hydraulic braking force or the target hydraulic pressure. The brake ECU 70 controls the hydraulic actuator 40 so that the wheel cylinder pressure becomes the target hydraulic pressure (S20). The brake ECU 70 determines the value of the control current supplied to the pressure-increasing linear control valve 66 and the pressure-decreasing linear control valve 67 by feedback control, for example.

  As a result, in the hydraulic brake unit 20, the brake fluid is supplied from the power hydraulic pressure source 30 to each wheel cylinder 23 via the pressure-increasing linear control valve 66, and braking force is applied to the wheels. Further, brake fluid is discharged from each wheel cylinder 23 through the pressure-reducing linear control valve 67 as necessary, and the braking force applied to the wheel is adjusted. In the present embodiment, a wheel cylinder pressure control system is configured including the power hydraulic pressure source 30, the pressure-increasing linear control valve 66, the pressure-decreasing linear control valve 67, and the like. A so-called brake-by-wire braking force control is performed by the wheel cylinder pressure control system. The wheel cylinder pressure control system is provided in parallel to the brake fluid supply path from the master cylinder unit 27 to the wheel cylinder 23.

  When brake-by-wire braking force control is performed, the brake ECU 70 closes the regulator cut valve 65 so that the brake fluid delivered from the regulator 33 is not supplied to the wheel cylinder 23. Further, the brake ECU 70 closes the master cut valve 64 and opens the simulator cut valve 68. This is because the brake fluid sent from the master cylinder 32 in accordance with the operation of the brake pedal 24 by the driver is supplied not to the wheel cylinder 23 but to the stroke simulator 69. During the brake regeneration cooperative control, a differential pressure corresponding to the magnitude of the regenerative braking force acts between the upstream and downstream of the regulator cut valve 65 and the master cut valve 64.

  In the above-described brake regenerative cooperative control, the regenerative braking force is preferentially generated and the shortage of the regenerative braking force with respect to the required braking force is compensated with the friction braking force. The present invention is not limited to such a regeneration priority mode. For example, the control unit may control the braking force in a regeneration assist mode in which the regenerative braking force is used supplementarily, or distributes the target deceleration to the distribution of the preset regeneration target value and friction target value, The braking force may be controlled in a regenerative combined mode that generates a regenerative braking force and a friction braking force.

  FIG. 4 is a flowchart for explaining a brake control mode switching process according to an embodiment of the present invention. In this embodiment, from the so-called complete regenerative cooperative control to completely compensate the regenerative braking force fluctuation by the friction braking force, the so-called incomplete cooperative control that suppresses the fluctuation of the friction braking force with emphasis on the brake feeling. When the high frequency fluctuation occurs in the regenerative braking force, the switching is performed.

  In one embodiment, the brake ECU 70 starts suppressing the variation in the friction braking force when the variation suppression start condition for the friction braking force is satisfied during the execution of the regenerative cooperative control. The brake ECU 70 continues to suppress the fluctuation of the friction braking force for a predetermined time except when the fluctuation suppression stopping condition is satisfied. After the predetermined time has elapsed, the brake ECU 70 cancels the suppression of the fluctuation of the friction braking force (for example, as shown in FIG. 3) and returns to normal regenerative cooperative control. The brake ECU 70 also cancels the fluctuation suppression of the friction braking force even when the fluctuation suppression stop condition is satisfied within the predetermined time.

  The brake ECU 70 repeatedly executes the processing shown in FIG. 4 at a predetermined control cycle (for example, several msec) during braking on the assumption that the conditions for permitting regenerative cooperative control are satisfied. The brake ECU 70 first determines whether or not ABS control is being executed (S22). When it is determined that the ABS control is not being executed (N in S22), the brake ECU 70 determines whether a communication abnormality with the hybrid ECU 7 has occurred (S24).

  When it is determined that the ABS control is being executed (Y in S22) and when it is determined that a communication abnormality has occurred (Y in S24), the brake ECU 70 continues the normal regenerative cooperative control. . This is because in these cases, it is important to ensure the braking force by causing the hydraulic braking force to quickly follow the sudden change in the regenerative braking force. That is, here, execution of ABS control and occurrence of communication abnormality are cited as examples of the fluctuation suppression stop condition. The brake ECU 70 calculates the target value of the hydraulic braking force based on the target deceleration and the regenerative braking force effective value, and updates the hydraulic braking force target value from the value obtained in the previous process (S32). Then, the brake ECU 70 controls the hydraulic actuator 40 using the updated value (S34).

  If it is determined that the communication with the hybrid ECU 7 is normal (N in S24), the brake ECU 70 further determines whether or not the condition for suppressing the fluctuation of the target value of the hydraulic braking force is satisfied (S26). . The fluctuation suppression condition includes that the change speed of the regenerative braking force exceeds a reference value. During normal braking, the regenerative braking force gradually increases as the vehicle decelerates. Accordingly, unlike this, when a large regenerative braking force change is detected or predicted in a short time, a change in the hydraulic braking force can be suppressed, thereby suppressing brake feeling disturbance.

  In the present embodiment, a part of the regenerative braking force that can be generated may be allocated to compensate for a decrease in engine brake. When a shift change is made during regenerative braking, the motor generator 4 is idled for a moment and the mechanical connection between the engine 2 and the drive wheels 9 is interrupted. That is, when the shift is switched, the state instantaneously corresponds to the shift position of the N range, and at this time, the deceleration due to the engine brake is reduced or eliminated. On the other hand, the electric motor 6 is continuously connected to the drive wheels 9 via a speed reduction mechanism. Therefore, the hybrid ECU 7 directs a part of the regenerative braking force for realizing the required braking force in order to simulate engine braking. Therefore, when it is detected that the decrease rate of the regenerative braking force to be applied to the required braking force exceeds the reference value, it can be considered that a shift change has been performed.

  For example, the brake ECU 70 determines whether or not the difference between the current value of the regenerative braking force and the previous value exceeds a threshold value A. The brake ECU 70 uses the net regenerative braking force obtained by subtracting the portion allocated to the engine brake to determine whether the above-described variation suppression condition is satisfied. In other words, this net regenerative braking force is the amount that can be applied to the required braking force. The comparison target with the current value is not limited to the previous value, and may be a value before the predetermined time t1. The predetermined time t1 corresponds to, for example, a plurality of calculation cycles.

  The threshold value A is set based on the wheel cylinder pressure increasing capability of the pressure increasing linear control valve 66. That is, the threshold A is set to the amount of change in the regenerative braking force that can be compensated by the pressure regulation response of the wheel cylinder pressure. The pressure-increasing linear control valve 66 is provided as a pressure-increasing control valve common to the four wheel cylinders 23. In this case, the threshold value A set based on the pressure increase response of the wheel cylinder 23 by the pressure increase linear control valve 66 is a considerably small value.

  When it is determined that the variation suppression condition is satisfied (Y in S26), the brake ECU 70 determines whether or not a predetermined suppression time T for suppressing the variation of the hydraulic braking force has elapsed (S28). ). This determination is performed when the variation suppression control has already been started. The suppression time T is set to a shift operation time, for example. In this way, fluctuations in the hydraulic braking force can be suppressed until the shift operation is completed. If it is determined that the suppression time T has not elapsed (N in S28), the brake ECU 70 maintains the hydraulic braking force target value at the previous value (S30), and the hydraulic actuator 40 is based on the target value. Is controlled (S34). The brake ECU 70 determines the value of the control current supplied to the pressure-increasing linear control valve 66 and the pressure-decreasing linear control valve 67 so that the wheel cylinder pressure becomes the target hydraulic pressure, similarly to S20 of FIG.

  When it is determined that the fluctuation suppression condition is not satisfied (N in S26), the brake ECU 70 updates the hydraulic braking force target value in the same manner as in the normal regenerative cooperative control (S32), and the hydraulic actuator 40 is changed. Control (S34). If it is determined that the suppression time T has elapsed (Y in S28), the brake ECU 70 ends the suppression of fluctuations in the hydraulic braking force, and updates the hydraulic braking force target value in the same manner as in normal regenerative cooperative control. (S32), the hydraulic actuator 40 is controlled (S34).

  With the above-described fluctuation suppression control, as shown in FIG. 5, the target value of the hydraulic braking force is kept constant when the regenerative braking force increases or decreases for a short time. Therefore, the influence on the brake feeling is reduced. On the other hand, as shown in FIG. 6 as a comparative example, when the hydraulic braking force is to follow the short-time increase / decrease in the regenerative braking force, the decrease (or increase) of the regenerative braking force and the hydraulic control The increase (decrease) in the power target value becomes equal. Although the actual hydraulic braking force is at a level that satisfies the braking request, it is generated with some delay from the target value. In the example shown in FIG. 6, the increase in the regenerative braking force and the increase in the hydraulic braking force simultaneously overlap, and the change in deceleration is amplified. In this case, the brake feeling may be affected.

  The regenerative braking force increases as the vehicle decelerates. For this reason, during braking, the ratio of the hydraulic braking force to the required braking force is usually large at the beginning of braking and decreases with deceleration. Similarly, the wheel cylinder pressure gradually decreases gradually. Therefore, it is typically sufficient for the pressure-increasing linear control valve 66 to operate once at the beginning of braking during the period from the start of one braking to the stop. Thereafter, the wheel cylinder pressure is regulated by the pressure-reducing linear control valve 67 as the vehicle decelerates.

  The above-described fluctuation suppression control is executed, for example, when the driver performs a shift-up operation or a shift-down operation during braking during which regenerative cooperative control is being performed. When the shift operation is detected or predicted, the hydraulic braking force (that is, the wheel cylinder pressure) is kept constant during the shift operation time from that point. Although the regenerative braking force can be changed by these shift operations, the follow-up of the hydraulic braking force to the change is limited. Therefore, the fluctuation of the regenerative braking force is not amplified by the hydraulic braking force, and the influence on the brake feeling is reduced. Further, the wheel cylinder pressure is not increased or decreased in accordance with the fluctuation of the regenerative braking force, and the operation frequency of the linear control valve is also reduced. For this reason, the service life of the linear control valve can be expected to be long.

  The present invention is not limited to the above-described embodiments, and an appropriate combination of the elements of each embodiment is also effective as an embodiment of the present invention. Various modifications such as design changes can be added to each embodiment based on the knowledge of those skilled in the art, and embodiments to which such modifications are added can also be included in the scope of the present invention. Here are some examples.

  The fluctuation suppression condition may include other conditions indicating that there has been a shift operation. The brake ECU 70 may directly detect whether or not there has been a shift operation, for example, based on shift information. Further, the fluctuation suppression condition may include a condition indicating that there is a high possibility that the shift operation will occur most recently, that is, that the shift is predicted most recently. The fluctuation suppression condition may include sensing a driver's contact with a shift operation member (for example, a shift knob).

  The brake ECU 70 may determine the presence or absence of a driver's contact based on information from the shift operation member sensing system. The sensing system may include a pressure sensitive sensor attached to the operating member. The pressure sensitive sensor may be a temperature sensor or a piezoelectric sensor. Further, the fluctuation suppression condition may include that the rotational speed of the engine or the motor has increased beyond a reference. The brake ECU 70 may execute the above-described variation suppression control when any of a plurality of variation suppression conditions is satisfied.

  Further, instead of keeping the hydraulic braking force target value constant, the brake ECU 70 may change the hydraulic braking force target value more gradually than usual with respect to fluctuations in the regenerative braking force. Since the brake fluid flow rate can be reduced, deterioration of the sealing performance of the linear control valve can be suppressed.

  For example, as shown in FIG. 7, the brake ECU 70 changes the hydraulic braking force target value with a gradient that is more limited than the change gradient of the normal hydraulic braking force target value obtained as an insufficient amount of the regenerative braking force with respect to the required braking force. May be. In FIG. 7, a normal hydraulic braking force target value is indicated by a broken line, and a hydraulic braking force target value with a limited gradient is indicated by a solid line. Even in this way, fluctuations in the hydraulic braking force can be suppressed, so that both durability of the hydraulic brake unit and brake feeling can be achieved.

  In the above-described embodiment, the example in which the friction braking force fluctuation suppression is applied to the hybrid vehicle has been described, but the present invention is not limited to this. Fluctuation braking force fluctuation suppression control according to the present invention can be applied to a vehicle in which motor torque is transmitted to wheels via a transmission. For example, it can be applied to an electric vehicle using a motor as a drive source. In the case of a shift change, a momentary large change in regenerative braking force occurs by momentarily passing through neutral. Therefore, the brake control device temporarily suppresses the fluctuation of the friction braking force, for example, when the shift is detected or predicted, or when the regenerative braking force is detected or predicted to decrease at a decreasing speed exceeding the reference. . In this way, the influence on the brake feeling due to the difference in the responsiveness between the regenerative braking force and the friction braking force can be reduced as in the above-described embodiment.

  7 Hybrid ECU, 10 Regenerative brake unit, 20 Hydraulic brake unit, 23 Wheel cylinder, 27 Master cylinder unit, 32 Master cylinder, 33 Regulator, 34 Reservoir, 60 Separation valve, 65 Regulator cut valve, 66 Booster linear control valve, 67 pressure-reducing linear control valve, 70 brake ECU, 73 control pressure sensor.

Claims (5)

A regenerative brake unit that includes a motor connected to the wheel via a speed change mechanism, and applies a regenerative braking force to the wheel by regeneration of the motor;
A friction brake unit for applying a friction braking force to the wheel;
A controller that controls the regenerative brake unit and the friction brake unit so as to generate the required braking force by using the regenerative braking force and the friction braking force together,
The said control part suppresses the fluctuation | variation of friction braking force, when the shift operation by a driver | operator is detected or estimated, The brake control apparatus characterized by the above-mentioned.   The brake control device according to claim 1, wherein the control unit keeps the friction braking force constant when a shift operation by the driver is detected or predicted.   3. The brake control device according to claim 1, wherein the control unit keeps the friction braking force constant for at least a shift operation time when a shift operation by a driver is detected or predicted.   2. The control unit according to claim 1, wherein fluctuation of the friction braking force is suppressed when an amount of the regenerative braking force that can be generated is limited to a request from the driving system of the vehicle. 4. The brake control device according to any one of 3. A regenerative braking unit that applies a regenerative braking force to the wheel by regenerating a motor for driving the wheel;
A friction brake unit for applying a friction braking force to the wheel;
A controller that controls the regenerative brake unit and the friction brake unit so as to generate the required braking force by using the regenerative braking force and the friction braking force together,
The control unit suppresses fluctuations in friction braking force when detecting or predicting that the reproducible braking force can be applied to the required braking force at a decreasing rate exceeding a reference. .

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