Electric braking system

Abstract

To provide an electric brake system which operates an electric parking brake adequately even under a condition of reduced power-supply voltage.SOLUTION: An electric brake system comprises a first electric parking brake 2 which is driven by a first electric motor 21, a second electric parking brake 3 which is driven by a second electric motor 31, a DC power source part 4 which supplies electric power to the first electric motor 21 and the second electric motor 31, and a controller 5 which controls a first control electric current which is supplied from the DC power source part 4 to the first electric motor 21 and a second control electric current which is supplied from the DC power source part 4 to the second electric motor 31. The controller 5 executes peak adjustment control which controls the first control electric current and the second control electric current so that peak of the first control electric current and peak of the second control electric current alternately appear multiple times, respectively when starting operations of the electric parking brakes 2, 3.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an electric brake system.

Background Art

[0002] Recently, in vehicles equipped with an electric parking brake, a control method for the electric parking brake when the power supply voltage drops has been studied. For example, in the brake device disclosed in Japanese Unexamined Patent Application Publication No. 2021-187183, it is possible to suppress excessive return of a linear member that may occur when the power supply voltage drops. In a state where the power supply voltage has dropped, the amount of movement of a linear member having an electric motor as a drive source may differ between when applying the brake and when releasing the brake. However, in the above brake device, it is possible to suppress the return amount of the linear member in such a state.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the above brake device, no countermeasure is taken when applying the parking brake in a state where the power supply voltage has dropped, and there is room for improvement in this regard. An object of the present invention is to provide an electric brake system that can appropriately operate an electric parking brake even in a state where the power supply voltage has dropped.

Means for Solving the Problems

[0005] The electric brake system of the present invention comprises: a first electric parking brake installed on one of the right and left wheels and driven by a first electric motor; a second electric parking brake installed on the other of the right and left wheels and driven by a second electric motor; a DC power supply unit that supplies power to the first and second electric motors; and a controller that controls a first control current supplied from the DC power supply unit to the first electric motor and a second control current supplied from the DC power supply unit to the second electric motor. The controller is configured to perform peak adjustment control of the first and second control currents so that the peaks of the first and second control currents alternate multiple times when the operation of the first and second electric parking brakes is started. [Effects of the Invention]

[0006] According to the present invention, peak adjustment control causes the peak timing of the left and right electric motors to be staggered, and the control current output from the DC power supply is leveled. Furthermore, because multiple peaks appear in each control current due to peak adjustment control, the inrush current generated in the present invention is reduced compared to when the control current is continuously supplied. Due to these effects, the rapid voltage drop in the DC power supply caused by the inrush current when operating each electric parking brake is suppressed. Therefore, according to the present invention, even if the power supply voltage (voltage of the power supply unit) is low for some reason, the voltage required for operation of the electric parking brake (system required voltage) is more easily maintained. In other words, according to the present invention, the system can be operated more stably and continuously, and the electric parking brake can be operated appropriately even when the power supply voltage is low. [Brief explanation of the drawing]

[0007] [Figure 1] This is a diagram showing the configuration of the electric brake system of this embodiment. [Figure 2] This is a diagram illustrating the configuration of the electric parking brake of this embodiment. [Figure 3]This is a conceptual diagram illustrating an example of peak adjustment control in this embodiment. [Figure 4] This is a conceptual diagram illustrating an example of peak adjustment control in this embodiment. [Figure 5] This is a flowchart illustrating an example of peak adjustment control in this embodiment. [Figure 6] This is a flowchart illustrating an example of peak adjustment control in this embodiment. [Modes for carrying out the invention]

[0008] Hereinafter, an electric brake system 1, which is one embodiment of the present invention, will be described in detail with reference to the figures. In addition to the embodiments described below, the present invention can be implemented in various forms with various modifications and improvements based on the knowledge of those skilled in the art.

[0009] As shown in Figure 1, the electric brake system 1 of this embodiment includes a first electric parking brake 2, a second electric parking brake 3, a battery 4 as a DC power supply unit, and a controller 5. In this example, the first electric parking brake 2 is installed on the right rear wheel (corresponding to the "right wheel") 91, and the second electric parking brake 3 is installed on the left rear wheel (corresponding to the "left wheel") 92. The first electric parking brake 2 and the second electric parking brake 3 may also be installed on the left and right front wheels 93 and 94.

[0010] As shown in Figure 2, the first electric parking brake 2 comprises a first electric motor 21, a conversion mechanism 22, a linear motion member 23, a pair of brake pads 241 and 242, and a caliper 25. The first electric motor 21 is the drive source for the first electric parking brake 2. In other words, the first electric parking brake 2 is driven by the first electric motor 21. The output shaft of the first electric motor 21 is connected to the conversion mechanism 22. The conversion mechanism 22 is a mechanism (device) that converts the rotational motion of the output shaft of the electric motor 21 into the linear motion of the linear motion member 23. The conversion mechanism 22 is composed of multiple gears and also functions as a reduction mechanism.

[0011] The linear motion member 23 is positioned opposite the brake pad 241 so as to press against one of the brake pads 241 by its own linear motion. The pair of brake pads 241 and 242 are positioned to sandwich the disc rotor 8, which rotates with the wheel. When the brake pad 241 is pressed towards the disc rotor 8 by the linear motion member 23, the pair of brake pads 241 and 242 sandwich the disc rotor 8, generating a braking force due to friction.

[0012] The caliper 25 is positioned relative to the wheel so as to straddle the disc rotor 8. The caliper 25 is equipped with a linear motion member 23 and brake pads 241 and 242. The conversion mechanism 22 has a self-locking function (for example, a mechanism with zero reverse efficiency). Therefore, when there is no driving force from the first electric motor 21, the linear motion member 23 is locked (position fixed). The linear motion member 23 does not move in response to pressure from the brake pads 241, but moves due to the driving force of the first electric motor 21.

[0013] The second electric parking brake 3 comprises a second electric motor 31, a conversion mechanism, a linear motion member, a pair of brake pads, and a caliper. The second electric parking brake 3 is driven by the second electric motor 31. Since the first electric parking brake 2 and the second electric parking brake 3 have the same configuration, the configuration description of the second electric parking brake 3 is omitted. Well-known electric brakes are used as the first electric parking brake 2 and the second electric parking brake 3.

[0014] Battery 4 is a power source that supplies power to the first electric motor 21 and the second electric motor 31 based on the control of the controller 5. The vehicle is equipped with wheel speed sensors 71 installed on each wheel 91-94, acceleration sensors 72 that detect acceleration in the longitudinal direction, a position sensor 73 that detects the position of the shift lever, and the like. The various sensors 71, 72, and 73 transmit their detection results to the controller 5. Communication within the vehicle is performed via CAN (car area network or controllable area network).

[0015] The controller 5 controls the first control current supplied from the battery 4 to the first electric motor 21, and the second control current supplied from the battery 4 to the second electric motor 31. When the parking brake is turned on by the user operating an operating device (for example, by pressing a button), the controller 5 supplies the first control current to the first electric motor 21 by making the battery 4 and the first electric motor 21 conductive, and supplies the second control current to the second electric motor 31 by making the battery 4 and the second electric motor 31 conductive.

[0016] The controller 5 includes an ECU 51, a first switching unit 52, and a second switching unit 53. The ECU 51 includes one or more processors and one or more memories, and is an electronic control unit that realizes the functions of the controller 5 and executes various processes. The first switching unit 52 is a part (device) that switches the connection state between the battery 4 and the first electric motor 21 between on (conductive) and off (interrupted). The second switching unit 53 is a part (device) that switches the connection state between the battery 4 and the second electric motor 31 between on (conductive) and off (interrupted). The ECU 51 controls the on / off states of the first switching unit 52 and the second switching unit 53. That is, the first switching unit 52 and the second switching unit 53 switch the connection state (conductive / interrupted) according to the control of the ECU 51 respectively. The first switching unit 52 and the second switching unit 53 are, for example, relays. In the description of the connection states of the switching units 52 and 53, "on" means "conductive" and "off" means "interrupted".

[0017] In normal control, when the parking brake is turned on by the user, the ECU 51 turns on both the first switching unit 52 and the second switching unit 53, continues the on state until a predetermined braking force is generated, and then turns both off after the predetermined braking force is generated. The ECU 51 may selectively execute normal control and peak adjustment control described later according to the situation.

[0018] Current detection units 541 and 542 and a voltage detection unit 55 are installed in the vehicle (or the controller 5). The current detection units 541 and 542 and the voltage detection unit 55 are connected to the ECU 51. The current detection unit 541 detects the first control current and transmits the detection value (current value) to the ECU 51. The current detection unit 542 detects the second control current and transmits the detection value (current value) to the ECU 51. The current detection units 541 and 542 are, for example, ammeters provided individually for the circuit through which the first control current flows and the circuit through which the second control current flows. The voltage detection unit 55 detects the voltage of the battery 4 and transmits the detection value (voltage value) to the ECU 51. The voltage detection unit 55 is, for example, a voltmeter.

[0019] (Peak adjustment control) When starting the operation of the electric parking brakes 2 and 3, the controller 5 is configured to execute "peak adjustment control" for controlling the first control current and the second control current so that the peak of the first control current and the peak of the second control current alternately appear a plurality of times respectively. A peak is the point where it switches from increasing to decreasing, and can also be said to be the maximum value. For example, as shown in FIG. 3 (upper side), when the controller 5 supplies power to the first electric motor 21 and the second electric motor 31, the peaks of the respective control currents are the peak P11 of one control current, the peak P22 of the other control current, the peak P12 of one control current, and the peak P22 of the other control current. The first control current and the second control current are controlled so as to appear in this order. As shown in FIG. 3 (lower side), according to the peak adjustment control, the total value of the left and right control currents is leveled, and the inrush current becomes smaller than before.

[0020] As an example of the peak adjustment control, in the example of FIG. 3 (upper side), when operating both electric parking brakes 2 and 3, the ECU 51 turns on the second switching unit 53 (the other switching unit) after turning on the first switching unit 52 (one switching unit), and turns off the second switching unit 53 after turning off the first switching unit 52. The "alternate on / off process" of turning off is executed a plurality of times. That is, the ECU 51 shifts the on / off timing of the two switching units 52 and 53. For example, the interval between the appearances of the peaks can be made the same for the first control current and the second control current. According to this alternate on / off process, the peak of the first control current (one control current) appears, and then the peak of the second control current (the other control current) appears. By executing this alternate on / off process a plurality of times, the peak of the first control current and the peak of the second control current alternately appear a plurality of times. That is, the peak adjustment control is executed by a plurality of alternate on / off processes.

[0021] In the alternating on / off processing, the ECU 51 may, for example, turn on the other switching unit 52, 53 in conjunction with turning off one of the switching units 52, 53. In other words, in the alternating on / off processing, the on of one unit and the off of the other unit may be performed simultaneously. Thus, the ECU 51 may, for at least a portion of the period during which peak adjustment control is being performed, turn off the second switching unit 53 in conjunction with turning on the first switching unit 52, and turn on the second switching unit 53 in conjunction with turning off the first switching unit 52. The ECU 51 may also perform the on of one unit and the off of the other unit in conjunction for the entire period of peak adjustment control (excluding the initial on).

[0022] The ECU 51 causes each control current to exhibit a predetermined number of peaks, and then maintains each switching unit 52 and 53 in the ON state. Each control current gradually decreases, exhibiting peaks in accordance with the ON / OFF cycles, and becomes a steady-state current after each switching unit 52 and 53 is maintained in the ON state. The ON / OFF cycles of each switching unit 52 and 53 are controlled so that each control current exhibits multiple peaks before becoming a steady-state current. In other words, the ON / OFF cycles of each switching unit 52 and 53 are performed at high speed.

[0023] Each control current increases in accordance with the generation of braking force on the corresponding wheel after it has become a steady current. When the brake pad 241 contacts the disc rotor 8 and braking force begins to be generated, the braking force increases in accordance with the increase in the control current. When the control current reaches a predetermined threshold, the ECU 51 determines that the braking force has reached a predetermined value and turns off the corresponding switching units 52 and 53. Even if the power supply to the electric motors 21 and 31 is stopped, the braking force is maintained by the self-locking function of the conversion mechanism 22. When releasing the braking force of the electric parking brakes 2 and 3 (releasing the lock), the controller 5 reverses the rotation of the first electric motor 21 and the second electric motor 31.

[0024] Another example of peak adjustment control is that when power is supplied to the electric parking brakes 2 and 3, the first switching unit 52 and the second switching unit 53 are turned on simultaneously, and one of the control currents may be controlled so that the slope (current value / time) of one control current is smaller than the slope of the other control current. The slope of the control currents can be adjusted, for example, by setting ECU circuit constants (hard) or control constants (soft). In this way, the ECU 51 can shift the peaks of the two control currents by controlling each control current so that the slopes of one control current and the other control current are different.

[0025] The flow of peak adjustment control will be explained with reference to Figures 4 and 5. When the parking brake is turned on at time t0, the ECU 51 turns on the first switching unit 52 and the second switching unit 53 (S101). That is, the controller 5 turns on both electric motors 21 and 31. In this example, the ECU circuit constants or control constants are set so that the slope (rising slope) of the second control current is smaller than the slope (rising slope) of the first control current. In other words, in peak adjustment control, the controller 5 is set so that the rising slope of the second control current is smaller than the rising slope of the first control current.

[0026] The ECU 51 has a time measurement function (also called a time counting function or timer function). For example, the ECU 51 measures elapsed time triggered by the on / off switching of at least one of the first switching unit 52 and the second switching unit 53. Furthermore, the ECU 51 also measures elapsed time triggered by the first on-by of at least one of the first switching unit 52 and the second switching unit 53 after the parking brake has been turned on by the user.

[0027] When a predetermined time In1 has elapsed from the time the first switching unit 52 and the second switching unit 53 are turned on (time t0) until time t1 (S102: Yes), the ECU 51 turns off the first switching unit 52 and keeps the second switching unit 53 on (S103). In other words, the controller 5 turns off the first electric motor 21 and keeps the second electric motor 31 on.

[0028] When a predetermined time In2 has elapsed since the previous off state of the first switching unit 52 (time t1) and it reaches time t2 (S104: Yes), the ECU 51 turns on the first switching unit 52 and turns off the second switching unit 53. In other words, at time t2, the controller 5 turns on the first electric motor 21 and turns off the second electric motor 31. This process of turning off an electric motor that is in the ON state and turning on an electric motor that is in the OFF state is also called an "on / off inversion process". Note that predetermined time In1 and predetermined time In2 may be set to the same value.

[0029] The ECU 51 determines whether a predetermined end time In3 has elapsed from time t0 (S106). If the end time In3 has not elapsed (S106: No), the ECU 51 determines whether a predetermined time In2 has elapsed since the previous on / off inversion process (S107). When the predetermined time In2 has elapsed since the previous on / off inversion process (time t2) and it is time t3 (S107: Yes), the process returns to step S103 and the on / off inversion process is executed again (S103). When the predetermined time In2 has elapsed from time t3 and it is time t4 (S104: Yes), the on / off inversion process is executed again (S105).

[0030] When the end time In3 has elapsed from time t0 to time t5 (S106: Yes), the ECU 51 terminates the peak adjustment control and turns on both switching units 52 and 53 (S108). As a result, each control current thereafter decreases towards the steady-state current value, either without producing a peak or after producing a peak. After the first control current becomes a steady-state current, the second control current becomes a steady-state current. When the first electric parking brake 2 begins to generate braking force on the wheels, the first control current gradually begins to increase. After the second electric parking brake 3 begins to generate braking force on the wheels, the second control current gradually begins to increase. The predetermined times In1, In2 and end time In3 are set so that the peaks of the first control current and the second control current each appear at least twice.

[0031] When the control current increases from the steady-state current and reaches a predetermined threshold, the ECU 51 determines that the wheel corresponding to that control current is locked. In this example, by adjusting the slope of the second control current, the right rear wheel 91 corresponding to the first control current is locked, and then the left rear wheel 92 corresponding to the second control current is locked.

[0032] The ECU 51 determines whether the right rear wheel 91 is locked based on the current value of the first control current (S109). If the right rear wheel 91 is locked (S109: Yes) (time t6), the ECU 51 turns off the first switching unit 52 and terminates control of the first electric motor 21 (S110). Similarly, the ECU 51 determines whether the left rear wheel 92 is locked based on the current value of the second control current (S111). If the left rear wheel 92 is locked (S112: Yes) (time t7), the ECU 51 turns off the second switching unit 53 and terminates control of the second electric motor 31 (S110). Since the ECU 51 monitors each control current, steps S109 and S111 are effectively executed simultaneously. With peak adjustment control, the time required for the wheels to lock is slightly longer compared to normal control.

[0033] According to this embodiment, peak adjustment control causes the peak timing of the left and right electric motors 21 and 31 to be shifted, and the control current output from the battery 4 is leveled. In addition, peak adjustment control causes multiple peaks to appear in each control current. As a result, the inrush current generated by peak adjustment control is lower than the inrush current generated by normal control. Due to these effects, the rapid voltage drop of the battery 4 caused by the inrush current when each electric parking brake is activated is suppressed. Therefore, according to this embodiment, even if the power supply voltage (voltage of battery 4) is low for some reason, the voltage required for the operation of the electric parking brakes 2 and 3 (system required voltage) is more easily maintained. In other words, according to this embodiment, the system can be operated more stably and continuously, and although the time until locking is slightly longer, the electric parking brakes 2 and 3 can be operated appropriately even when the power supply voltage is low. A state in which the voltage of battery 4 is low includes, for example, a state in which battery 4 is degraded, or a state in which battery 4 is degraded and the temperature is low, such as on a winter morning. Even in such a state, according to this embodiment, the parking brake can be activated.

[0034] Furthermore, for each control current, as in this embodiment, by simultaneously turning one on and the other off, the timing of the peak (maximum value) of one control current and the timing of the minimum value of the other can be synchronized. This allows for a more leveling of the total control current.

[0035] (others) The present invention is not limited to the above embodiments. For example, as shown in the callout in Figure 4, the controller 5 may also perform peak adjustment control when the control current begins to increase from the steady-state current. In this case, for example, when the ECU 51 detects that the first control current has increased after passing through the steady-state current, it performs on / off processing so that multiple peaks appear. Also, when the ECU 51 detects that the second control current has increased after passing through the steady-state current, it controls the second control current so that the peaks of the first control current and the peaks of the second control current appear alternately, and performs peak adjustment control. When both control currents increase from the steady-state current, the ECU 51 performs peak adjustment control, for example, by alternating on / off processing. Thus, when the controller 5 starts the operation of the electric parking brakes 2 and 3, it performs peak adjustment control for an initial predetermined period, then terminates the peak adjustment control, and performs peak adjustment control again when the first control current and the second control current increase from the steady current. This suppresses the rapid increase in the control current when braking force begins to be generated on the wheels. As the wheels approach the locked state, the voltage of the battery 4 gradually decreases due to power consumption. However, with this configuration, the inrush current when braking force is generated can be leveled, and system shutdown near lock can also be suppressed. The ECU 51 may pre-calculate (estimate) the difference in the timing of the start of current increase in the first control current and the second control current when the wheels are locked, based on the detection results of the respective current detection units 541 and 542.

[0036] Furthermore, if the controller 5 detects that the vehicle is moving (sliding backward) based on the results of the wheel speed sensor 71 or the like while peak adjustment control is being performed, it may stop peak adjustment control and perform normal control. Normal control is a control that keeps each switching unit 52 and 53 in the ON state until the wheels are locked. With this, if the vehicle starts to slide backward, the braking force on the wheels can be quickly increased by normal control.

[0037] Furthermore, the controller 5 may execute peak adjustment control only when the execution conditions for peak adjustment control are met. The execution conditions are set to, for example, "the voltage of the battery 4 is below a predetermined value" and / or "the shift lever is in the parking position". The execution conditions may also include "the road surface gradient at the vehicle position is within a predetermined range". For example, as shown in Figure 6, the ECU 51 acquires information on the voltage of the battery 4 based on the detection value of the voltage detection unit 55 (S201). If the voltage of the battery 4 is below a predetermined value (S202: Yes), the ECU 51 determines whether or not the shift lever is in the parking position (S203). If the shift lever is in the parking position (S203: Yes), the ECU 51 determines that the execution conditions are met and executes peak adjustment control in response to the parking brake being turned on (S204).

[0038] If the shift lever is not in the parking position (S203: No), the ECU 51 determines whether the road surface gradient at the vehicle's position (stopping position) is within a predetermined range (-α < gradient < β) (S205). If the road surface gradient is within the predetermined range (S205: Yes), the ECU 51 determines that the execution conditions are met and performs peak adjustment control in response to the parking brake being applied (S204). If the road surface gradient is not within the predetermined range (S205: No), the ECU 51 determines that the execution conditions are not met and performs normal control in response to the parking brake being applied (S206). Also, if the voltage of the battery 4 is above a predetermined value (S202: No), the ECU 51 determines that the execution conditions are not met and performs normal control in response to the parking brake being applied (S206). The determination of the execution conditions may be performed periodically when the parking brake is off, or when the parking brake is applied.

[0039] Thus, the ECU 51 is configured to selectively perform normal control, which maintains the first switching unit 52 in the ON state until the right rear wheel 91 is locked (until a predetermined braking force is generated on the right rear wheel 91), and the second switching unit 53 in the ON state until the left rear wheel 92 is locked (until a predetermined braking force is generated on the left rear wheel 92), and peak adjustment control. The ECU 51 may also be configured to perform peak adjustment control only when the conditions for performing peak adjustment control are met. In other words, the controller 5 may be configured to selectively perform normal control and peak adjustment control depending on the voltage of the battery 4, the position of the shift lever, etc. (depending on the result of determining the execution conditions). This enables more situation-appropriate control.

[0040] Furthermore, even when peak adjustment control is performed, variations in the wiring resistance of the vehicle due to aging or other factors may cause the peak timings of each control current to become closer together. Based on the detection results of each current detection unit 541, 542, if the ECU 51 detects that the interval between the appearance of the peak of the first control current and the peak of the second control current has fallen below a predetermined threshold, it may shift the on / off timing of one of the switching units 52, 53 by a predetermined value to widen the appearance interval. In this case, the ECU 51 may also advance the on / off timing of one of the switching units 52, 53 by a predetermined value. Such adjustments may be performed one or more times until the appearance interval from one peak to the other peak exceeds the threshold. In this way, the controller 5 can adjust the left and right peak intervals.

[0041] The ECU can also be considered a computer. Furthermore, the electric parking brakes 2 and 3 may be of other well-known configurations, such as drum type. Also, the on / off switching of the parking brake is not limited to user operation, but may be performed automatically (for example, during autonomous driving). Furthermore, the determination of whether or not the wheels are locked may be performed by any well-known method, not limited to the above. [Explanation of Symbols]

[0042] 1...Electric braking system, 2...First electric parking brake, 21...First electric motor, 3...Second electric parking brake, 31...Second electric motor, 4...Battery (DC power supply unit), 5...Controller, 51...ECU, 52...First switching unit, 53...Second switching unit, 91...Right rear wheel (right wheel), 92...Left rear wheel (left wheel).

Claims

1. A first electric parking brake is installed on either the right or left wheel and is driven by a first electric motor, A second electric parking brake is installed on the other of the right and left wheels and is driven by a second electric motor, A DC power supply unit that supplies power to the first electric motor and the second electric motor, A controller that controls a first control current supplied from the DC power supply unit to the first electric motor and a second control current supplied from the DC power supply unit to the second electric motor, Equipped with, The aforementioned controller, When initiating the operation of the first electric parking brake and the second electric parking brake, the system is configured to perform peak adjustment control to control the first control current and the second control current such that the peaks of the first control current and the peaks of the second control current appear alternately multiple times. The controller is configured such that, in the peak adjustment control, the increasing slope of the rise of the second control current is smaller than the increasing slope of the rise of the first control current. Electric braking system.

2. A first electric parking brake is installed on either the right or left wheel and is driven by a first electric motor, A second electric parking brake is installed on the other of the right and left wheels and is driven by a second electric motor, A DC power supply unit that supplies power to the first electric motor and the second electric motor, A controller that controls a first control current supplied from the DC power supply unit to the first electric motor and a second control current supplied from the DC power supply unit to the second electric motor, Equipped with, The aforementioned controller, When initiating the operation of the first electric parking brake and the second electric parking brake, the system is configured to perform peak adjustment control to control the first control current and the second control current such that the peaks of the first control current and the peaks of the second control current appear alternately multiple times. The aforementioned controller, When the operation of the first electric parking brake and the second electric parking brake is initiated, the peak adjustment control is performed for an initial predetermined period, then the peak adjustment control is terminated, and when the first control current and the second control current increase from steady-state currents, the peak adjustment control is performed again. Electric braking system.

3. The aforementioned controller, The connection state between the DC power supply unit and the first electric motor is controlled by a first switching unit that switches between on and off, The connection state between the DC power supply unit and the second electric motor is controlled by a second switching unit that switches between on and off, An ECU that controls the on / off state of the first switching unit and the second switching unit, Equipped with, In the peak adjustment control, the ECU performs an alternating on / off process multiple times, in which it turns on the first switching unit, then turns on the second switching unit, and then turns off the first switching unit, then turns off the second switching unit. The electric brake system according to claim 1 or 2.

4. The aforementioned controller, The connection state between the DC power supply unit and the first electric motor is controlled by a first switching unit that switches between on and off, The connection state between the DC power supply unit and the second electric motor is controlled by a second switching unit that switches between on and off, An ECU that controls the on / off state of the first switching unit and the second switching unit, Equipped with, The ECU, during at least a portion of the period in which the peak adjustment control is being performed, turns off the second switching unit in conjunction with the first switching unit being turned on, and turns on the second switching unit in conjunction with the first switching unit being turned off. The electric brake system according to claim 1 or 2.

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