JP2007082306A - Power supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power supply device that detects an abnormality generated in a power supply circuit, in the power supply device equipped with a plurality of power systems. <P>SOLUTION: The power supply device comprises: a plurality of battery power supplies; an electric operation device driven by power supplied from the plurality of battery power supplies; a plurality of power circuits that supply power to the electric operation device from the plurality of battery power supplies, and are connected to the electric operation device by making the power flow into each other; a plurality of power backflow prevention means that prevent the backflow of currents of the plurality of power circuits. The power supply device also comprises: a plurality of power switching means that switch the energization and disconnection of the plurality of power circuits by controlling the electric operation device; a plurality of power monitor devices that input the voltage information of the plurality of battery power supplies to the electric operation device; and an abnormality detection means of a circuit of the power supply device. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a power supply device that includes a plurality of power supply systems and controls so that power is supplied from other normal power supply systems when an abnormality occurs in any of the power supply systems.

This kind of technology is equipped with multiple power supplies, and even if the battery with the remaining amount is accidentally pulled out, charging between the batteries is performed, and the minimum battery system is maintained with the battery with the less remaining side. Have been disclosed (for example, see Patent Document 1).
JP 2003-70172 A

  However, in the above prior art, an abnormality in one power supply system is detected by monitoring the voltage of the power supply circuit, and in the case of an abnormality, the power supply is switched to the other power supply and is provided downstream of the monitor location. It is impossible to detect a failure of the backflow prevention diode itself. In a system that requires a redundant power supply from the viewpoint of safety, such as a brake device, it is necessary not only to continue control with the power supply system remaining after the failure but also to announce the failure. However, the above prior art has a problem that even if it has a plurality of power supply systems, there is a part where failure of the power supply system cannot be detected, so that the meaning of constructing a redundant power supply may be lost in the first place. .

  The present invention has been made paying attention to the above problems, and an object of the present invention is to provide a power supply device that detects an abnormality occurring in a power supply circuit in a power supply device including a plurality of power supply systems. There is.

  In order to achieve the above object, in the present invention, a plurality of battery power supplies, an electric actuator driven by electric power supplied from the plurality of battery power supplies, and electric power are supplied to the electric actuators from the plurality of battery power supplies, respectively. And a plurality of power supply circuits that join each other and connect to the electric actuator, and a plurality of power supply backflow prevention means that respectively prevent backflow of currents of the plurality of power supply circuits. A plurality of power supply switching means provided upstream of the power supply backflow prevention means, each for switching between energization and interruption of the plurality of power supply circuits under the control of the electric actuator; the plurality of power supply switching means; and the plurality of power supply backflows And a plurality of voltage information of the plurality of battery power supplies respectively input to the electric actuator. Provided a power supply monitor circuit, and abnormality detecting means of the circuit of the power supply device, the

  In the power supply device of the present invention, it is possible to detect a failure occurring in a power supply circuit including a plurality of power supply systems.

  The best mode for realizing the power supply device of the present invention will be described below with reference to the drawings.

  First, the configuration will be described.

  FIG. 1 is a system diagram illustrating an overall configuration of a brake system to which the power supply device according to the first embodiment is applied.

  The brake system in the present embodiment controls the brake main control device 2 that controls the braking force of the front and rear wheels based on information from each sensor and the like, and controls the front wheel hydraulic brake unit 3 based on the command value of the brake main control device 2. A front wheel hydraulic brake control device 1 is provided.

  The front wheel hydraulic brake control device 1 is a hydraulic brake that controls the operation of the left and right front wheel hydraulic brakes B1 and B2 via the front wheel hydraulic brake unit 3 based on a braking command signal from the brake main control device 2. It is a by-wire control means.

  The front wheel hydraulic brake unit 3 includes a brake hydraulic pump provided separately from the master cylinder in the unit and a motor for driving the pump. The front wheel hydraulic brake unit 3 responds to a control command from the front wheel hydraulic brake control device 1. Supply hydraulic pressure to brakes B1 and B2.

  The front wheel hydraulic brake control device 1 is configured to be capable of feedback control by a hydraulic pressure monitor using the wheel hydraulic pressure sensors WP1 and WP2.

  The front wheel hydraulic brake unit 3 and the brake pedal BP are connected by a hydraulic circuit so that a fail-safe valve (not shown) is released at the time of failure so that the pedaling force applied to the brake pedal BP is transmitted to the front wheel hydraulic brakes B1 and B2. It is composed.

  The front-wheel hydraulic brake control device 1 is supplied with electric power from a microcomputer 16 (see FIG. 2, which corresponds to the electric actuator according to claim 1), and the microcomputer 16 receives a first power supply PWR1 and a second power supply PWR2. Is supplied with power. The microcomputer 16 is activated by a first ignition switch signal or a second ignition switch signal for starting the engine by the first power supply PWR1 or the second power supply PWR2, or a wakeup switch signal such as a brake lamp switch.

  On the other hand, the left and right rear wheel electric brake units 4 and 5 are electric brake actuators and have a control communication line common to the rear wheels. Further, the motor and the like in the unit can be controlled based on the braking command from the brake main control device 2.

  This electric brake applies a braking force to the rear wheel based on the pedal operation information of the driver, and generates a braking force by pressing a brake pad against a brake disk by a motor or the like, for example. Further, when a regenerative brake control device 7 to be described later is operated, the left and right rear wheel electric brakes are obtained by subtracting the braking force generated by the regenerative brake control device 7 from the required braking force of the rear wheels. Generated by B3 and B4.

  Note that the rear wheel side that employs an electric brake does not generate braking force when the system is shut down during a failure. Also, the rear wheel electric brake unit 4 is supplied with power only from the first power supply PWR1, and the rear wheel electric brake unit 5 is supplied with power only from the second power supply PWR2, and is supplied like the front wheel hydraulic brake control device 1. The source is not a double system. However, the rear wheel has a smaller braking force than the front wheel (generally, the braking force ratio between the front wheel and the rear wheel is about 7: 3). For example, even if the brake-by-wire control fails, the braking force is sufficient only with the front wheel. Can be secured.

  On the rear wheel side, in addition to the rear wheel electric brake units 4 and 5, a brake generator BG that generates a braking force by generating electric power by the rotational force of the wheel, and a regenerative brake control device 7 that controls the operation of the brake generator BG. Is provided. The regenerative brake control device 7 monitors the SOC (State Of Charge) of a battery that can be stored outside the figure, and transmits the SOC to the brake main control device 2. Further, the regenerative brake control device 7 controls the operation of the brake generator BG based on a command signal from the brake main control device 2.

  Each front and rear wheel is provided with wheel speed sensors V1S, V2S, V3S, and V4S for detecting the wheel speed. These wheel speed sensor values V1, V2, V3, and V4 are transmitted to the brake main control device 2.

  The brake pedal BP is provided with sensors SEN1, SEN2, and SEN3 for detecting three brake pedal operation information. That is, as a performance unique to brake-by-wire, sensors for detecting three brake pedal operation information are provided so that accurate measurement (that is, detection of the driver's operation intention) can be performed even if one sensor fails. ing.

  The brake main control device 2 calculates front and rear wheel braking forces and transmits a control command to each device. The brake main control device 2 receives brake pedal operation signals S1, S2, S3 and signals from other control devices 6 such as a first ignition switch signal, a second ignition switch signal, a wake-up switch signal, and an engine control device. Entered. Similarly to the front wheel hydraulic brake control device 1, power is supplied from the microcomputer 16, and power is supplied to the microcomputer 16 from the first power supply PWR1 and the second power supply PWR2.

  Each of the above devices is connected by three communication lines, T1 connecting the front wheel hydraulic brake control device 1, the brake main control device 2, the rear wheel electric brake units 4, 5, the brake main control device 2, and the regenerative brake. Communication is performed between T2 connecting the control device 7 and T3 connecting the brake main control device 2 and the other control device 6.

  The brake main control device 2 includes a front wheel hydraulic brake control device 1 and a rear wheel electric brake unit 4 based on the operation of the brake pedal BP and vehicle behavior (wheel speed, steering angle, yaw rate, front / rear G, lateral G, etc.). 5. The control command is transmitted to the regenerative brake control device 7 and the like. Specifically, normal control that increases braking force according to the depression force on the brake pedal BP, vehicle dynamics control system that controls vehicle behavior by brake fluid pressure, and wheel lock during braking is avoided by decompression control, etc. An anti-lock brake system, a traction control system that suppresses drive wheel slip caused by excessive torque of the drive wheel during driving, and the like are executed, and the brake braking force of each wheel is optimally controlled according to the driving situation.

[Details of power supply device]
FIG. 2 is a circuit configuration of a power supply device 8 (brake ECU power supply unit) that supplies power to the front wheel hydraulic brake control device 1, the brake main control device 2, and the rear wheel electric brake units 4 and 5.

  The power supply apparatus includes a battery power source (first and second power sources PWR1 and PWR2), a power source circuit (first and second power source circuits 10 and 11), and a power relay circuit (first and second power source relay circuits 12 and 14). (Corresponding to the power supply switching means of claim 1), power supply backflow prevention means (first and second backflow prevention diodes 13 and 15), power supply monitor circuit (first and second power supply monitor circuits 19 and 20), microcomputer 16, power relay trigger circuit (first and second power relay trigger circuits 17 and 18), external trigger signal monitor circuit (first and second ignition switch signal monitor circuits 21 and 22, wake-up signal monitor circuit 23), and The 5V power generation circuit 24 is configured.

  The external trigger signal activates and shuts off the power supply device 8 from the outside. The external trigger signal includes an ignition switch (hereinafter referred to as IGN SW) signal and a wakeup (hereinafter referred to as WUP) signal.

  The IGN SW signal is an IGN SW ON / OFF signal with switch contacts connected to the first and second power supplies PWR1 and PWR2, and is output to the first and second power supply relay trigger circuits 17 and 18 and the microcomputer 16. Is done. The WUP signal is a trigger signal output from the vehicle electrical unit when the door lock is released, and is output to the first and second power supply relay trigger circuits 17 and 18 and the microcomputer 16.

  The first and second power supplies PWR1 and PWR2 supply power to the microcomputer 16 via the first and second power supply circuits 10 and 11, respectively.

  On the first power supply circuit 10, a first power supply relay circuit 12 and a first backflow prevention diode 13 are provided in order from the first power supply PWR1 side (upstream) to the microcomputer 16 side (downstream). Similarly, a second power supply relay circuit 14 and a second backflow prevention diode 15 are provided on the second power supply circuit 11 in order from the second power supply PWR2 side (upstream) to the microcomputer 16 side (downstream).

  The first power supply circuit 10 and the second power supply circuit 11 merge downstream of the first backflow prevention diode 13 and the second backflow prevention diode 15, and are connected to the microcomputer 16 via the 5V power supply generation circuit 24.

  The first power relay circuit 12 and the second power relay circuit 14 energize and shut off the first power circuit 10 and the second power circuit 11, respectively.

  The first backflow prevention diode 13 and the second backflow prevention diode 15 are connected from one power supply circuit (the first power supply circuit 10 or the second power supply circuit 11) to the other power supply circuit (the first power supply circuit 10 or the second power supply circuit 11). To prevent current from flowing to

  The 5V power supply generation circuit 24 is a step-down circuit that generates a 5V constant voltage from the first power supply PWR1 and the second power supply PWR2.

  The microcomputer 16 outputs a command to the first power supply relay circuit 12 and the second power supply relay circuit 14 to energize or cut off the first power supply circuit 10 and the second power supply circuit 11.

  The first power supply relay trigger circuit 17 outputs a signal indicating either conduction or interruption of the first power supply circuit 10 to the first power supply relay circuit 12 based on a command output from the microcomputer 16.

  Similarly, the second power supply relay trigger circuit 18 outputs a signal indicating either conduction or interruption of the second power supply circuit 11 to the second power supply relay circuit 14 based on a command output from the microcomputer 16.

  The first power supply circuit 10 branches between the first power supply relay circuit 12 and the first backflow prevention diode 13 to form a branch point 25 and a branch circuit 27. The branch circuit 27 is connected to the microcomputer 16, and a first power supply monitor circuit 19 is provided on the branch circuit 27. The first power supply monitor circuit 19 detects the voltage value at the branch point 25, and the detected value is output to the microcomputer 16.

  Similarly, the second power supply circuit 11 branches between the second power supply relay circuit 14 and the second backflow prevention diode 15 to form a branch point 26 and a branch circuit 28. The branch circuit 28 is connected to the microcomputer 16, and a second power supply monitor circuit 20 is provided on the branch circuit 28. The second power supply monitor circuit 20 detects the voltage value at the branch point 26, and the detected value is output to the microcomputer 16.

  The external trigger signal monitor circuit (first and second IGN SW signal monitor circuits 21 and 22 and WUP signal monitor circuit 23) detects ON / OFF of the external trigger signal (first and second IGN SW signal and WUP signal). The detected signal is output to the microcomputer 16. Based on this signal, the microcomputer 16 outputs external trigger cut signals (first and second IGN SW cut signals, WUP cut signals) to the first power relay trigger circuit 17 and the second power relay trigger circuit 18.

  The first and second power supply holding signals are signals that the microcomputer 16 outputs to the first and second power supply relay trigger circuits 17 and 18 in order to hold the energization of the first and second power supply relay circuits 12 and 14. It is. As a result of the energization of the first and second power supply relay circuits 12 and 14 being held by the first and second power holding signals, power is supplied to the microcomputer 16 for a certain period of time even after the external trigger signal is turned off.

  The microcomputer 16 outputs ON / OFF of the power holding signal or the external trigger cut signal in a predetermined pattern at a predetermined time after the external trigger signal is turned ON / OFF, and the power supply monitor circuit 19, 20 or the external trigger is output. By receiving monitor signals from the signal monitor circuits 21, 22, and 23, abnormality diagnosis of relays, diodes, and the like is performed.

[Details of power relay circuit]
The configuration of the first power relay circuit 12 is shown in FIG. The first power relay circuit 12 includes a first power relay (power MOSFET 12a, parasitic diode 12b), resistors 12c and 12d, and a semiconductor switch (transistor 12e). The power MOSFET 12a energizes and cuts off the first power supply circuit 10 from the first power supply PWR1 (upstream) toward the first backflow prevention diode 13 (downstream). The parasitic diode 12b provided between the source and drain of the power MOSFET 12a cuts off the current from the first power supply PWR1 to the first backflow prevention diode 13 when the first power supply circuit 10 is cut off.

  The gate of the power MOSFET 12 a is connected to the first power supply relay trigger circuit 17. On the circuit connecting the gate and the first power supply relay trigger circuit 17, a resistor 12d is provided on the gate side, and a transistor 12e is provided on the first power supply relay trigger circuit 17 side. A circuit branches from between the resistor 12d and the transistor 12e and is connected to the upstream side of the power MOSFET 12a. A resistor 12c is provided on this branch circuit. The transistor 12 e switches between energization and interruption of the power MOSFET 12 a according to a signal from the first power supply relay trigger circuit 17.

  The voltage applied to the gate of the power MOSFET 12 a is switched by a signal input from the first power supply relay trigger circuit 17. When the input signal is Lo, the power MOSFET 12a does not pass current, and at the same time, the parasitic diode 12b prevents current from the first power supply PWR1 side to the first backflow prevention diode 13 side. On the other hand, when the signal from the first power supply relay trigger circuit 17 is Hi, the power MOSFET 12a passes a current.

  Similarly to the first power relay circuit 12, the second power relay circuit 14 also includes a second power relay (power MOSFET 14a, parasitic diode 14b), resistors 14c and 14d, and a semiconductor switch (transistor 14e) as shown in FIG. The second power supply circuit 11 is switched between energization and cutoff by a signal input from the second power supply relay trigger circuit 18.

[Details of power supply relay trigger circuit]
The configuration of the first power supply relay trigger circuit 17 is shown in FIG. The first power supply relay trigger circuit 17 includes a first power supply relay energization control diode (diodes 17a, 17b, 17c), resistors 17d, 17e, and semiconductor switches (transistors 17f, 17g).

  The transistor 17f receives the input of the first IGN SW cut signal controlled by the microcomputer 16 and invalidates the Hi output of the first IGN SW signal. The transistor 17g receives the input of the WUP cut signal controlled by the microcomputer 16 and invalidates the Hi output of the WUP signal.

  On the circuit from the first IGN SW signal input side (upstream) to the first power relay circuit 12 side (downstream), a resistor 17d and a first IGN SW trigger diode 17a are provided in order from the upstream. Similarly, on the circuit from the WUP signal input side (upstream) to the first power relay circuit 12 side (downstream), a resistor 17e and a first power system WUP diode 17b are provided in order from the upstream.

  These two circuits are connected downstream of the diodes 17a and 17b to form connection points 17h and 17i. A circuit that receives the input of the first power holding signal branches from the connection point 17i, and a diode 17c is provided on the branch circuit.

  The diodes 17a and 17b allow only current from the external trigger signal input side to the first power supply relay circuit 12 side, respectively. The diode 17c allows only a current from the microcomputer 16 to the connection point 17i.

  A circuit that receives the input of the first IGN SW cut signal branches from between the resistor 17d and the diode 17a, and a transistor 17f is provided on the branch circuit. Similarly, a circuit that receives the input of the WUP cut signal branches from between the resistor 17e and the diode 17b, and a transistor 17g is provided on the branch circuit.

  The first power relay trigger circuit 17 outputs a Hi signal to the first power relay circuit 12 if at least one of the first IGN SW signal, the WUP signal, or the first power holding signal is a Hi output. On the other hand, the first IGN SW cut signal from the microcomputer 16 invalidates the Hi output of the first IGN SW signal. WUP cut signal invalidates Hi output of WUP signal.

  As shown in FIG. 4, the second power supply relay trigger circuit 18 also includes the first power supply relay diodes (diodes 18a, 18b, 18c), resistors 18d, 18e, and semiconductor switches (transistors 18f, 18g). The configuration is the same as that of the relay trigger circuit 17.

  Similar to the first power relay trigger circuit 17, the second power relay trigger circuit 18 is a second power relay if at least one of the second IGN SW signal, the WUP signal, or the second power holding signal is a Hi output. The Hi signal is output to the circuit 14. On the other hand, the second IGN SW cut signal from the microcomputer 16 invalidates the Hi output of the second IGN SW signal. The WUP cut signal disables the Hi output of the WUP signal.

  Next, the operation of the power supply device 8 according to the first embodiment will be described.

  By setting the power supply to a dual system (first and second power supply systems), even when a failure occurs in one of the power supply systems, normal voltage power is always supplied to the microcomputer 16. Therefore, normal voltage power is always supplied from the microcomputer 16 to the brake control devices 1 and 2 and the brake units 4 and 5. Here, the first and second power supply systems include power supply circuits 10 and 11, power supply relay circuits 12 and 14, and backflow prevention diodes 13 and 15, respectively.

  However, even if it has a plurality of power supply systems in this way, if there is a part that cannot be detected in the failure occurring in the circuit of the power supply device 8, the effect of using a plurality of power supply systems is diminished. Therefore, it is necessary not only to continue the control with the other power supply system remaining after the failure of one power supply system but also to announce the failed part.

  Therefore, in the first embodiment, during the start-up process and the shut-off process of the power supply device 8, an abnormality occurring in the circuit of the power supply device 8 is detected, and self-diagnosis in which part on the circuit has occurred. And announce.

  The failure to be diagnosed includes ON / OFF fixation of the first power relays 12a and 12b and the second power relays 14a and 14b, the first and second backflow prevention diodes 13 and 15, the first and second IGN SW trigger diodes 17a. , 18a, disconnection / short circuit of the first and second power supply system WUP diodes 17b and 18b, and the first and second power supply holding signal diodes 17c and 18c.

  The microcomputer 16 receives the IGN SW signal and WUP signal monitor values and the monitor value of the power supply monitor circuits 19 and 20, and outputs the IGN SW cut signal, the WUP cut signal, and the power holding signal. Each abnormality occurring in the circuit is detected based on the combination of these input / output values.

  5 to 12 are flowcharts showing the flow of the circuit abnormality diagnosis of the power supply device 8 in the first embodiment.

  Hereinafter, the flow of each diagnosis process will be described with reference to the main flowchart of FIG.

  In S <b> 1, an external trigger signal, that is, the first and second IGN SW signals and the WUP signal are turned ON to the power supply device 8. These signals are ON until the control process of the power supply device 8 is completed.

  In S100, diagnosis process 1 is performed. When the external trigger signal is ON and the power holding signal is Lo, the first and second power supply relays 12a, 12b, 14a, and 14b are fixed OFF and the first and second power holding signal diodes 17c and 18c are short-circuited. To detect.

  In S200, diagnostic processing 2 is performed. When the external trigger signal is ON and the power holding signal is Lo, disconnection of the first and second power supply system WUP diodes 17b and 18b is detected.

  In S300, diagnostic processing 3 is performed. When the external trigger signal is ON and the power holding signal is Lo, the disconnection of the first and second IGN SW trigger diodes 17a and 18a is detected.

  In S2, the power supply device 8 performs control processing.

  In S3, the microcomputer 16 detects the states of the first and second IGN SW signals and the WUP signal from the external trigger signal monitor circuits 21, 22, and 23, and determines whether or not they are OFF. If it is OFF, the process proceeds to S400. If it is not OFF, the process proceeds to S2. Specifically, the power supply device 8 continues the control process while any of the external trigger signals is in the ON state. When all of these signals are in the OFF state, the power supply device 8 starts the cutoff process.

  In S400, the diagnosis process 4 is performed. When the external trigger signal is OFF and the first and second power holding signals are both Hi, the first and second power relays 12a, 12b, 14a, and 14b are fixed OFF, and the first and second power holding signal diodes 17c. , 18c is detected.

  In S4, when the second power supply system is disconnected, the power supply is all shut off after the first power supply system shutoff in S407. In this case, the microcomputer 16 becomes inoperable, and the operation of the power supply device 8 ends. The step moves to END, and the abnormality is determined at the next activation. If power can be supplied from the second power supply system, the process proceeds to S500.

  In S500, diagnosis processing 5 is performed. When the external trigger signal is OFF, the first power holding signal is Lo, and the second power holding signal is Hi, the first power relays 12a and 12b are fixed ON, the first backflow prevention diode 13 is short-circuited, and the second power supply system A short circuit of the WUP diode 18b is detected.

  In S5, when the first power supply system is disconnected, all power supply is shut off after the second power supply system is shut off in S506. In this case, the microcomputer 16 becomes inoperable, and the operation of the power supply device 8 ends. The step moves to END, and the abnormality is judged at the next startup. If power can be supplied from the first power supply system, the process proceeds to S600.

  In S600, a diagnosis process 6 is performed. When the external trigger signal is OFF, the first power holding signal is Hi, and the second power holding signal is Lo, the second power relays 14a and 14b are fixed ON, the second backflow prevention diode 15 is short-circuited, and the first power system A short circuit of the WUP diode 17b is detected.

  In S700, a diagnosis process 7 is performed. When the external trigger signal is OFF, the first power holding signal is Hi, and the second power holding signal is Hi, a short circuit of the first and second IGN SW signal diodes 17a and 18a is detected.

  Next, the flow for each diagnosis process will be described with reference to the flowcharts of FIGS.

[Diagnosis process 1]
FIG. 6 shows the flow of the diagnostic process 1. This control corresponds to S100 in FIG.

  In S101, the activation process of the power supply device 8 is started using the ON input of the external trigger signal as the activation trigger.

  In S102, it is determined whether or not the stored diagnostic count value is 0 or 3. When the diagnostic count value is 0 or 3, the process proceeds to S106, and when it is not 0 or 3, (1 or 2), the process proceeds to S103. Here, the diagnosis count value 0 indicates that the diagnosis has not been performed, and the diagnosis count value 3 indicates that the diagnosis at the previous operation has ended normally.

  In S103, it is determined whether or not the diagnostic count value is 1. If it is 1, the process proceeds to S104, and if it is not 1 (2), the process proceeds to S105. Here, the diagnosis count value 1 indicates that the microcomputer 16 becomes inoperable due to the second power relays 14a and 14b being fixed OFF or the second backflow prevention diode 15 being disconnected during the previous operation of the power supply device 8 (S407). Indicates that the diagnostic process has been completed. The diagnosis count value 2 indicates that the microcomputer 16 has become inoperable due to the first power supply relays 12a and 12b being fixed OFF or the first backflow prevention diode 13 being disconnected during the previous operation (S506), and the diagnosis process has been completed. .

  In S104, it is determined that the second power supply relays 14a, 14b are fixed OFF or the second backflow prevention diode 15 is disconnected, and the second power supply system disconnection abnormality flag is set to 1, and then the process proceeds to S106.

  In S105, it is determined that the first power relays 12a and 12b are fixed OFF or the first backflow prevention diode 13 is disconnected, and the first power supply system disconnection abnormality flag is set to 1, and then the process proceeds to S106.

  In S106, 0 is set in the diagnosis count value, and the process proceeds to S107.

  In S107, the first power holding signal and the second power holding signal are set to Lo output, and the process proceeds to S108.

  In S108, it is determined whether or not the first power supply monitor value is at a predetermined voltage (for example, 7V) indicating the conduction state of the first power supply relays 12a and 12b. When it is equal to or greater than the predetermined value, the process proceeds to S110, and when it is smaller than the predetermined value, the process proceeds to S109.

  In S109, it is determined that the first power relays 12a and 12b are fixed OFF or the first power holding signal diode 17c is short-circuited. After setting the first power system disconnection abnormality flag to 1, the process proceeds to S110. As can be seen from FIG. 4, when the first power holding signal diode 17c is short-circuited, an external trigger signal (first IGN SW signal, WUP signal) is output to the microcomputer 16 through the shorted diode 17c. Since it is not output to the first power supply relay circuit 12 side, a short circuit abnormality of the diode 17c is detected.

  In S110, it is determined whether or not the second power supply monitor value is at a predetermined voltage (7 V) indicating the conduction state of the second power supply relays 14a and 14b. When it is equal to or greater than the predetermined value, the process proceeds to S112, and when it is smaller than the predetermined value, the process proceeds to S111.

  In S111, it is determined that the second power supply relays 14a and 14b are fixed OFF or the second power supply holding signal diode 18c is short-circuited. After setting 1 in the second power supply system disconnection abnormality flag, the process proceeds to S200.

[Diagnosis process 2]
FIG. 7 shows the flow of the diagnostic process 2. This control corresponds to S200 in FIG.

  If the first power monitor value is Lo level when the first IGN SW signal is cut, it is determined that the first power system WUP diode 17b is disconnected. Similarly, if the second power supply monitor value is Lo level when the second IGN SW signal is cut, it is determined that the second power supply system WUP diode 18b is disconnected.

  In S201, the microcomputer 16 outputs the first IGN SW cut signal Hi, and fixes the first IGN SW trigger diode 17a to OFF. As a result, the first power supply system WUP diode 17b is always turned on.

  In S202, it is determined whether or not the first power supply monitor value is at a predetermined voltage (for example, 7V) indicating the conduction state of the first power supply relays 12a and 12b. When it is equal to or greater than the predetermined value, the process proceeds to S205, and when it is smaller than the predetermined value, the process proceeds to S203.

  In S203, it is determined whether or not the first power system disconnection abnormality flag is 1. If it is 1, the process proceeds to S205, and if it is not 1, the process proceeds to S204.

  In S204, it is determined that the first power supply system WUP diode 17b is disconnected abnormally, 1 is set in the first power supply system WUP diode disconnection abnormality flag, and the process proceeds to S205. It has already been confirmed in S203 that the first power system disconnection abnormality flag is not 1, that is, the first power relays 12a and 12b are not fixed to OFF and the first power holding signal diode 17c is not short-circuited. Therefore, it can be determined that the disconnection abnormality of the diode 17b.

  In S205, the microcomputer 16 outputs the second IGN SW cut signal as Hi, and fixes the second IGN SW trigger diode 18a to OFF. As a result, the second power supply system WUP diode 18b is always turned on.

  In S206, it is determined whether or not the second power supply monitor value is at a predetermined voltage (for example, 7V) indicating the conduction state of the second power supply relays 14a and 14b. When it is equal to or greater than the predetermined value, the process proceeds to S209, and when it is smaller than the predetermined value, the process proceeds to S207.

  In S207, it is determined whether or not the second power system disconnection abnormality flag is 1. If it is 1, the process proceeds to S209. If it is not 1, the process proceeds to S208.

  In S208, it is determined that the second power supply system WUP diode 18b is disconnected abnormally, 1 is set in the second power supply system WUP diode disconnection abnormality flag, and the process proceeds to S209.

  In S209, the microcomputer 16 outputs the first IGN SW cut signal and the second IGN SW cut signal to Lo, and the OFF fixing of the first IGN SW trigger diode 17a and the second IGN SW trigger diode 18a is released. Move to S300.

[Diagnosis process 3]
FIG. 8 shows the flow of the diagnosis process 3. This control corresponds to S300 in FIG.

  If the first power supply monitor value is Lo level when the WUP signal is cut, it is determined that the first IGN SW trigger diode 17a is disconnected. Similarly, if the second power monitor value is Lo level when the WUP signal is cut, it is determined that the second IGN SW trigger diode 18a is disconnected.

  In S301, the microcomputer 16 outputs the WUP signal cut signal as Hi, and fixes the first and second power supply system WUP diodes 17b and 18b to OFF. As a result, the first and second IGN SW trigger diodes 17a and 18a are always turned on.

  In S302, it is determined whether or not the first power supply monitor value is at a predetermined voltage (for example, 7V) indicating the communication state of the first power supply relays 12A and 12b. When it is equal to or larger than the predetermined value, the process proceeds to S305, and when it is smaller than the predetermined value, the process proceeds to S303.

  In S303, it is determined whether or not the first power system disconnection abnormality flag is 1. If it is 1, the process proceeds to S305, and if it is not 1, the process proceeds to S304.

  In S304, it is determined that the first IGN SW trigger diode 17a is disconnected abnormally, 1 is set in the first power supply system IGN SW diode disconnected abnormality flag, and the process proceeds to S305. It has already been confirmed in S303 that the first power system disconnection abnormality flag is not 1, that is, the first power relays 12a and 12b are not fixed to OFF and the first power holding signal diode 17c is not short-circuited. Therefore, it can be determined that the disconnection of the diode 17a is abnormal.

  In S305, it is determined whether or not the second power supply monitor value is at a predetermined voltage (for example, 7 V) indicating the conduction state of the second power supply relays 14a and 14b. If it is equal to or greater than the predetermined value, the process proceeds to S308, and if it is smaller than the predetermined value, the process proceeds to S306.

  In S306, it is determined whether or not the second power system disconnection abnormality flag is 1. If it is 1, the process proceeds to S308, and if it is not 1, the process proceeds to S307.

  In S307, it is determined that the second IGN SW trigger diode 18a is disconnected abnormally, 1 is set in the second power supply system IGN SW diode disconnected abnormality flag, and the process proceeds to S308.

  In S308, the microcomputer 16 outputs the WUP signal cut signal Lo, and releases the OFF fixing of the first power holding diode 17b and the second power holding diode 18b.

  In S309, the first power holding signal and the second power holding signal are output as Hi, and after the power supply to the microcomputer 16 is secured, the process proceeds to S2.

[Diagnosis process 4]
FIG. 9 shows the flow of the diagnostic process 4. This control corresponds to S400 in FIG.

  If the first power monitor value is at the Lo level, it is determined that the first power relays 12a and 12b are fixed OFF or the first power holding signal diode 17c is disconnected. Similarly, if the second power supply monitor value is Lo level, it is determined that the second power supply relays 14a and 14b are fixed OFF or the second power supply holding signal diode 18c is disconnected.

  In S401, the shut-off process of the power supply device 8 is started.

  In S402, 1 is set in the diagnosis count value, and the process proceeds to S403.

  In S403, it is determined whether or not the first power supply monitor value is at a predetermined voltage (for example, 7V) indicating the conduction state of the first power supply relays 12a and 12b. If it is equal to or greater than the predetermined value, the process proceeds to S405, and if it is smaller than the predetermined value, the process proceeds to S404.

  In S404, it is determined that the first power supply relays 12a and 12b are fixed OFF or the first power supply holding diode 17c is disconnected, and the first power supply system disconnection abnormality flag is set to 1, and the process proceeds to S405.

  In S405, it is determined whether or not the second power supply monitor value is at a predetermined voltage (for example, 7V) indicating the conduction state of the second power supply relays 14a and 14b. If it is equal to or greater than the predetermined value, the process proceeds to S407, and if it is smaller than the predetermined value, the process proceeds to S406.

  In S406, it is determined that the second power supply relays 14a and 14b are fixed OFF or the second power supply holding signal diode 18c is disconnected, and the second power supply system disconnection abnormality flag is set to 1, and the process proceeds to S407.

  In S407, the first power holding signal is set to Lo output, the first power supply system is turned off, and the process proceeds to S4. Here, only the second power holding signal is output Hi.

[Diagnosis process 5]
FIG. 10 shows the flow of the diagnostic process 5. This control corresponds to S500 in FIG.

  When the first power supply monitor value is not at the Lo level, it is determined that the first power supply relays 12a and 12b are fixed to ON or the backflow prevention diode 13 is short-circuited. Further, when the WUP signal monitor value is not equivalent to OFF, it is determined that the second power supply system WUP diode 18b is short-circuited.

  In S501, it is determined whether or not the first power supply monitor value is at a predetermined voltage (for example, 7 V) indicating the conduction state of the first power supply relays 12a and 12b. When it is smaller than the predetermined value, the process proceeds to S503, and when it is equal to or greater than the predetermined value, the process proceeds to S502.

  In S502, it is determined that the first power supply relays 12a and 12b are fixed to ON or the first backflow prevention diode 13 is short-circuited, the first power system disconnection abnormality flag is set to 1, and the process proceeds to S503. As can be seen from FIG. 2, when the first backflow prevention diode 13 is short-circuited, the current from the second power supply circuit 11 flows back to the first power supply circuit 10 through the shorted diode 13. A short circuit abnormality of the diode 13 is detected.

  In S503, the microcomputer 16 determines whether or not the WUP signal monitor value indicates OFF equivalent. If it is equivalent to OFF, the process proceeds to S505, and if it is not equivalent to OFF, the process proceeds to S504.

  In S504, it is determined that the WUP signal trigger abnormality (second power supply system WUP diode 18b is short-circuited) on the second power supply system side, 1 is set in the second power supply system WUP diode short-circuit abnormality flag, and the process proceeds to S505. As can be seen from FIG. 4, if the second power supply system WUP diode 18b is short-circuited, the second power holding signal is output to the WUP signal monitor circuit 23 and the like through the shorted diode 18b. A short circuit abnormality of the diode 18b is detected.

  In S505, 2 is set in the diagnosis count value, and the process proceeds to S506.

  In S506, the first power holding signal is set to Hi output, the second power holding signal is set to Lo output, the second power supply system is turned off, and the process proceeds to S5.

[Diagnosis process 6]
FIG. 11 shows the flow of the diagnostic process 6. This control corresponds to S600 in FIG.

  When the second power supply monitor value is not at the Lo level, it is determined that the second power supply relays 14a and 14b are fixed ON or the second backflow prevention diode 15 is short-circuited. When the WUP signal monitor value is not equivalent to OFF, it is determined that the first power supply system WUP diode 17b is short-circuited.

  In S601, it is determined whether or not the second power supply monitor value is at a predetermined voltage (for example, 7 V) indicating the conduction state of the second power supply relays 14a and 14b. When it is smaller than the predetermined value, the process proceeds to S603, and when it is equal to or greater than the predetermined value, the process proceeds to S602.

  In S602, it is determined that the second power supply relays 14a and 14b are fixed to ON or the second backflow prevention diode 15 is short-circuited, 1 is set in the second power supply system disconnection abnormality flag, and the process proceeds to S603.

  In S603, the microcomputer 16 determines whether the WUP signal monitor value indicates OFF equivalent. If it is equivalent to OFF, the process proceeds to S701, and if it is not equivalent to OFF, the process proceeds to S604.

  In S604, it is determined that the WUP signal trigger abnormality is on the first power supply system side (short circuit of the first power supply system WUP diode 17b), 1 is set in the first power supply system WUP diode short circuit abnormality flag, and the process proceeds to S700.

[Diagnosis process 7]
FIG. 12 shows the flow of the diagnostic process 7. This control corresponds to S700 in FIG.

  When the first IGN SW signal monitor value is equivalent to ON, it is determined that the first IGN SW signal diode 17a is short-circuited abnormally. Similarly, when the second IGN SW signal monitor value is equivalent to ON, it is determined that the second IGN SW signal diode 18a is short-circuited abnormally.

  In S701, the diagnosis count value is set to 3, and the process proceeds to S702.

  In S702, the second power holding signal is set to Hi output, both the first power supply system and the second power supply system are energized, and the process proceeds to S703.

  In S703, the microcomputer 16 determines whether or not the first IGN SW signal monitor value indicates OFF equivalent. If it is equivalent to OFF, the process proceeds to S705. If it is not equivalent to OFF, the process proceeds to S704.

  In S704, it is determined that the trigger of the first IGN SW signal is abnormal (short circuit of the first IGN SW signal diode 17a), the first IGN SW diode short circuit abnormality flag is set to 1, and the process proceeds to S705. As can be seen from FIG. 4, if the first IGN SW signal diode 17a is short-circuited, the first power holding signal is output to the first IGN SW signal monitor circuit 22 and the like through the shorted first IGN SW signal diode 17a. Therefore, a short circuit abnormality of the first IGN SW signal diode 17a is detected.

  In S705, the microcomputer 16 determines whether or not the second IGN SW signal monitor value indicates OFF equivalent. If it is equivalent to OFF, the process proceeds to S707, and if it is not equivalent to OFF, the process proceeds to S706.

  In S706, it is determined that the trigger of the second IGN SW signal is abnormal (the second IGN SW signal diode 18a is short-circuited), the second IGN SW diode short-circuit abnormality flag is set to 1, and the flow proceeds to S707.

  In S707, the first power supply holding signal and the second power supply holding signal are set to Lo output, and the first power supply system and the second power supply system are cut off. All power supply is cut off, the microcomputer becomes inoperable, and the operation of the power supply device 8 ends.

[Time chart of diagnosis processing]
FIG. 13 is a time chart of the diagnosis process of the circuit of the power supply device 8.

  At time t1, the microcomputer 16 is activated by the first and second IGN SW signals and the WUP signal, and the power supply device 8 starts the activation process from the stopped state. The external trigger signal is turned ON, and the first power supply relay circuit 12 is turned on by the Hi signal of the first power supply relay trigger circuit 17. Similarly, the second IGN SW signal is turned ON, and the second power supply relay circuit 14 is turned on by the Hi signal of the second power supply relay trigger circuit 18. In addition, after the microcomputer 16 is activated, the first and second power supply monitor values that the microcomputer 16 monitors the voltage values of the first and second power supply circuits 10 and 11 through the first and second power supply monitor circuits 19 and 20 are displayed. However, it becomes Hi level indicating energization of the first and second power supply relay circuits 12 and 14. After the microcomputer 16 is activated, the first and second power holding signals are not output and are fixed as Lo signals until the diagnosis process 3 is completed.

  From time t1 to t2, it is determined whether or not the first and second power supply monitor values are at the Hi level indicating conduction of the first and second power supply relay circuits 12 and 14, and disconnection abnormality of each power supply system is detected. Diagnosis processing 1 is performed.

  At time t2, a case where the microcomputer 16 outputs the first and second IGN SW cut signals as Hi is shown. Of the input external trigger signal, the Hi output of the first and second IGN SW signals is invalidated and becomes the Lo output, so that only the WUP signal becomes the Hi output.

  From time t2 to t3, it is determined whether the first and second power supply monitor values are at the Hi level indicating the conduction of the first and second power supply relay circuits 12 and 14, and the first and second power supply system WUP diodes are determined. Diagnosis processing 2 for detecting disconnection abnormality 17b, 18b is performed.

  At time t3, the first and second IGN SW cut signals are output Lo from the microcomputer 16, while the WUP cut signal is output Hi. Of the input external trigger signal, the Hi output of the WUP signal is invalidated and becomes the Lo output, and only the first and second IGN SW signals become the Hi output.

  From time t3 to t4, it is determined whether the first and second power supply monitor values are at the Hi level indicating conduction of the first and second power supply relay circuits 12 and 14, and the first and second IGN SW signal diodes 17a are determined. , 18a is detected.

  At time t4, the microcomputer 16 outputs the WUP cut signal Lo, while the first and second power holding signals are output Hi. The first and second IGN SW signals and WUP signals all become Hi outputs, and at the same time, the first and second power supply holding signals become Hi outputs.

  From time t4 to t5, after the start-up process of the power supply device 8 is continued, the control process of the power supply device 8 is performed.

  At time t5, the first and second IGN SW signals and the WUP signal are all output Lo and are fixed to OFF, whereby the power supply device 8 starts the cutoff process. The microcomputer 16 always outputs either the first power holding signal or the second power holding signal as Hi for a certain period of time after the external trigger signal is turned OFF until the power supply device 8 is shut off. To. Thereby, at least one of the first and second power supply relay circuits 12 and 14 is made conductive, thereby enabling power supply to the microcomputer 16. That is, even if a failure occurs in one power supply system, the microcomputer 16 operates normally.

  From time t5 to t6, it is determined whether the first and second power supply monitor values are at the Hi level indicating the conduction of the first and second power supply relay circuits 12 and 14, and the first and second power supply systems are disconnected. A diagnosis process 4 for detecting an abnormality is performed.

  At time t6, the microcomputer 16 outputs the first power holding signal Lo while maintaining the Hi output of the second power holding signal. The first power supply relay circuit 12 is cut off, and the first power supply monitor value becomes Lo level.

  From time t6 to t7, it is determined whether or not the first power supply monitor value is at the Lo level indicating that the first power supply relay circuit 12 is cut off, and a short circuit abnormality in the first power supply system is detected. A diagnosis process 5 is performed for determining whether the second power supply system WUP diode 18b is short-circuited by determining whether or not it is equivalent to OFF.

  At time t7, the microcomputer 16 outputs the first power holding signal Hi and then outputs the second power holding signal Lo. The second power supply relay circuit 14 is cut off, and the second power supply monitor value becomes Lo level.

  From time t7 to t8, it is determined whether or not the second power supply monitor value is at the Lo level indicating that the second power supply relay circuit 14 is cut off, and a short circuit abnormality in the second power supply system is detected. A diagnosis process 6 is performed for determining whether the first power supply system WUP diode 17b is short-circuited by determining whether or not it corresponds to OFF.

  At time t8, the microcomputer 16 outputs the second power holding signal Hi. The first and second power supply relay circuits 12 and 14 are turned on, and the first and second power supply monitor values become Hi level.

  From time t8 to t9, it is determined whether or not the first and second IGN SW monitor values are equivalent to OFF, and a diagnosis process 7 is performed to detect a short circuit abnormality of the first and second IGN SW signal diodes 17a and 18a. .

  At time t9, the microcomputer 16 outputs the first and second power holding signals Lo. Since both the first and second power supply relay circuits 12 and 14 are cut off, power supply to the microcomputer 16 is cut off, and the operation of the power supply device 8 ends.

[Effect of Example 1]
In the first embodiment, the backflow prevention diodes 13 and 15 downstream (on the microcomputer 16 side) of the power supply relay circuits 12 and 14 of the power supply circuits 10 and 11 are OR-connected, and the power supply relay circuit 12 is connected to each of the power supply circuits 10 and 11. , 14 and backflow prevention diodes 13, 15 are provided with power supply monitor circuits 19, 20 so that the microcomputer 16 can monitor the voltage of the power supplies PWR1, 2.

  As a result, after the microcomputer 16 is activated, the power relay circuits 12 and 14 are switched between conduction and interruption as appropriate, and the result is monitored by the power monitor circuits 19 and 20, thereby preventing the first and second backflow prevention. A disconnection / short circuit abnormality occurring in the diodes 13 and 15 can be detected and announced to the driver. For this reason, in a brake device that needs to construct a redundant power supply from the viewpoint of safety, power supply is reliably performed.

  Furthermore, since the configuration of the power supply circuit 8 serves as an abnormality detection circuit for the power relay circuits 12 and 14 and the power relay trigger circuits 17 and 18 as well as the backflow prevention diodes 13 and 15, a diagnostic circuit is further added. Therefore, it is possible to improve the reliability of the power supply system while maintaining the cost.

[Other embodiments]
The best mode for carrying out the present invention has been described based on the first embodiment. However, the specific configuration of the present invention is not limited to the first embodiment and does not depart from the gist of the present invention. Any changes in the design of the range are included in the present invention.

  For example, in the first embodiment, the brake system is a rear wheel electric brake, but is not limited thereto, and may be a rear wheel hydraulic brake.

  The power supply relay for conducting and shutting off the power supply circuit is not limited to the power MOSFET, and a mechanical relay or the like may be used.

  In the power relay circuit, the semiconductor switch for switching between conduction and interruption of the power relay is not limited to the bipolar transistor, and an FET or the like may be used.

  In the first embodiment, the power supply device 8 is provided separately from the front wheel hydraulic brake control device 1, the brake main control device 2, and the rear wheel electric brake units 4, 5. Are incorporated in these control devices and may be integrated with these control devices.

  Further, technical ideas other than the claims that can be grasped from the first embodiment will be described together with the effects thereof.

(A) In the power supply device according to claim 1,
After the electric actuator is activated, the electric actuator shuts off the plurality of power supply switching means one by one, and short-circuit abnormality of the plurality of power supply backflow prevention means based on voltage information of the plurality of battery power supplies And a means for detecting continuity fixing abnormality of the plurality of power supply switching means.

  Even in the case where a short circuit failure (ON of the power relays 12a, 12b, 14a, 14b, or short circuit of the backflow prevention diodes 13, 15) occurs in any power system, the power relays 12a, 12b of each power system , 14a and 14b are shut off one by one, and it is possible to determine that there is an abnormality when the power monitor value does not indicate a shut-off equivalent level. Therefore, even when the backflow prevention diodes 13 and 15 that may possibly cause unstable power supply to the power supply device 8 are short-circuited, an abnormality can be reliably detected and an announcement to the driver can be made by lighting a warning light or the like. Has the effect.

(B) In the power supply device according to claim 1,
After the electric actuator is activated, the electric actuator sequentially conducts the plurality of power supply switching means one by one, and the disconnection abnormality of the plurality of power supply backflow prevention means is based on voltage information of the plurality of battery power supplies. And a means for detecting an interruption and sticking abnormality of the plurality of power supply switching means.

  Even in the case where a disconnection failure occurs (the power relays 12a, 12b, 14a, 14b are fixed OFF or the backflow prevention diodes 13, 15 are disconnected) in any power system, the power relays 12a, 12b of each power system , 14a and 14b are conducted one by one, and it can be determined that there is an abnormality when the power supply device 8 is not energized. Therefore, the power supply relays 12a, 12b, 14a, 14b can be reliably detected by detecting the power supply circuit failure such as the OFF fixation, the backflow prevention diodes 13, 15 being disconnected, and the driver can be announced by lighting the warning light. Has an effect.

(C) In the power supply device according to claim 1,
Providing a plurality of power supply switching control means for connecting the plurality of power supply switching means respectively to switch conduction / cutoff of the plurality of power supply switching means;
The plurality of power supply switching control means includes a plurality of trigger signal input paths, a plurality of current backflow prevention means for preventing backflow of the plurality of trigger signals on the plurality of trigger signal input paths, and the electric operation A plurality of trigger cut signal input paths capable of disabling each of the plurality of trigger signal inputs by control of the device,
The power supply device according to claim 1, wherein the input paths of the plurality of trigger signals are joined and connected to the plurality of power source switching units.

  In the power relay trigger circuit (corresponding to the power switching control means described in (C) above), the IGN SW signal trigger diodes 17a and 18a, the WUP diodes 17b and 18b, and the power holding diodes 17c and 18c (the above diodes are the above). (C) (corresponding to current backflow prevention means described in the above) was OR-connected. As a result, the Hi signal input of either the external trigger signal or the power supply holding signal is output to the power supply relay circuits 12 and 14 as an ON signal for conducting the power supply relay circuits 12 and 14. Here, the Hi input of the external trigger signal can be invalidated by the external trigger cut signal output from the microcomputer 16, and the conduction and cutoff of the power relay circuits 12 and 14 are controlled. Therefore, when the power supply monitor value of any power supply system is smaller than the predetermined voltage and indicates an interruption, if the power supply system is not broken, only one of the external trigger signals of that power supply system is used. By enabling it, it is possible to determine the disconnection failure of the external trigger diodes 17a, 18a, 17b, and 18b. Therefore, there is an effect that the circuit failure such as the disconnection failure of the external trigger diodes 17a, 18a, 17b, and 18b can be reliably detected, and the announcement to the driver can be made by lighting the warning lamp or the like.

(D) In the power supply device according to claim 1,
A power supply apparatus comprising a power MOSFET parasitic diode as the power backflow prevention means.

  A diode is widely used as a means for preventing a reverse current flow. This is due to the rectifying action of the diode that the resistance is small for the forward current flow and the resistance is large for the reverse current flow. However, a voltage drop occurs because resistance occurs even in the forward current flow. For this reason, in the configuration in which the current that has passed through the diode is supplied to the microcomputer 16, for example, when the voltage drops, for example, during cranking, a voltage drop due to the diode further occurs, resulting in 5 V for the 5 V power generation circuit 24. There is a possibility that the voltage necessary for generating the power cannot be supplied. Therefore, there is a possibility that 5V voltage cannot be supplied to the microcomputer 16. Therefore, in the first embodiment, a parasitic diode of a power MOSFET may be used instead of the backflow prevention diodes 13 and 15. In this case, since the current does not flow through the parasitic diode but flows between the shorted source and drain of the power MOSFET, no voltage drop occurs. That is, by switching the power MOSFET of the power supply system that selects conduction, a voltage equivalent to the voltage of the battery power supply can be supplied to the 5V power supply generation circuit 24. Therefore, there is no effect of a forward voltage drop as in the case where the backflow prevention diodes 13 and 15 are used, and there is an effect that the operation margin when the battery voltage is low is increased.

It is a block diagram of the brake system carrying this power supply apparatus. It is a block diagram of the circuit of this power supply apparatus. It is a block diagram of a 1st, 2nd power supply relay circuit. It is a block diagram of a 1st, 2nd power supply relay trigger circuit. It is the main flowchart which showed the flow of the diagnostic process for detecting a failure of a power supply circuit. It is the flowchart which showed the flow of the diagnostic process 1 for detecting the failure of a power supply circuit. It is the flowchart which showed the flow of the diagnostic process 2 for detecting the failure of a power supply circuit. It is the flowchart which showed the flow of the diagnostic process 3 for detecting the failure of a power supply circuit. It is the flowchart which showed the flow of the diagnostic process 4 for detecting the failure of a power supply circuit. It is the flowchart which showed the flow of the diagnostic process 5 for detecting the failure of a power supply circuit. It is the flowchart which showed the flow of the diagnostic process 6 for detecting the failure of a power supply circuit. It is the flowchart which showed the flow of the diagnostic process 7 for detecting the failure of a power supply circuit. It is a time chart of the diagnostic process for detecting the failure of a power supply circuit.

Explanation of symbols

8 power supply device 10 first power supply circuit 11 second power supply circuit 12 first power supply relay circuit 13 first backflow prevention diode 14 second power supply relay circuit 15 second backflow prevention diode 16 microcomputer 17 first power supply relay trigger circuit 18 second Power supply relay trigger circuit 19 First power supply monitor circuit 20 Second power supply monitor circuit
PWR1 1st power supply
PWR2 Second power supply

Claims (1)

Multiple battery power supplies,
An electric actuator driven by electric power supplied from the plurality of battery power sources;
A plurality of power supply circuits for supplying electric power to the electric actuator from the plurality of battery power sources, and joining the electric actuators to each other;
A plurality of power supply backflow prevention means for preventing backflow of currents of the plurality of power supply circuits, respectively;
In a power supply device comprising:
A plurality of power supply switching means provided upstream of the plurality of power supply backflow prevention means, respectively for switching between energization and shutoff of the plurality of power supply circuits under the control of the electric actuator;
A plurality of power supply monitor circuits provided between the plurality of power supply switching means and the plurality of power supply backflow prevention means, respectively, for inputting voltage information of the plurality of battery power supplies to the electric actuator;
Means for detecting an abnormality in the circuit of the power supply device;
A power supply device characterized by comprising:

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