Electric brake 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 technology]

[0002] Recently, in vehicles equipped with electric parking brakes, methods for controlling the electric parking brakes when the power supply voltage drops have been studied. For example, the brake device disclosed in JP 2021-187183 A can suppress excessive return of the linear member that can occur when the power supply voltage drops. When the power supply voltage drops, the amount of movement of the linear member driven by an electric motor may differ between when the brakes are applied and when the brakes are released. In such a state, the brake device can suppress the amount of return of the linear member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2021-187183 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above brake device does not provide a solution for applying the parking brake when the power supply voltage is low, and in this respect, there is room for improvement in the above brake device. An object of the present invention is to provide an electric brake system that can properly operate the electric parking brake even when the power supply voltage is low. [Means for solving the problem]

[0005] The electric brake system of the present invention includes a first electric parking brake installed for one of a right wheel or a left wheel and driven by a first electric motor, a second electric parking brake installed for the other of the right wheel or the left wheel and driven by a second electric motor, a DC power supply unit that supplies power to the first electric motor and the second electric motor, 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 execute peak adjustment control that controls the first control current and the second control current so that peaks of the first control current and the second control current alternately appear multiple times when starting operation of the first electric parking brake and the second electric parking brake. Effect of the Invention

[0006] According to the present invention, the peak timing is shifted between the left and right electric motors by peak adjustment control, and the control current output from the DC power supply unit is leveled. Furthermore, since multiple peaks appear in each control current by peak adjustment control, the inrush current generated by the present invention is lower than when the control current is continuously supplied. These actions suppress a sudden voltage drop in the DC power supply unit due to the inrush current when each electric parking brake is operated. Therefore, according to the present invention, even if the power supply voltage (voltage of the power supply unit) is reduced for some reason, the voltage required for the operation of the electric parking brake (system required voltage) is easily maintained. In other words, according to the present invention, the system can be operated continuously more stably, and the electric parking brake can be operated appropriately even if the power supply voltage is reduced. [Brief description of the drawings]

[0007] [Figure 1] 1 is a configuration diagram of an electric brake system according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a configuration diagram of an electric parking brake according to the present embodiment. [Diagram 3]FIG. 4 is a conceptual diagram for explaining an example of peak adjustment control according to the present embodiment. [Figure 4] FIG. 4 is a conceptual diagram for explaining an example of peak adjustment control according to the present embodiment. [Diagram 5] 5 is a flowchart illustrating an example of peak adjustment control according to the present embodiment. [Figure 6] 5 is a flowchart illustrating an example of peak adjustment control according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] An electric brake system 1 according to an embodiment of the present invention will be described in detail below with reference to the drawings. In addition to the following examples, the present invention can be embodied in various forms with various modifications and improvements based on the knowledge of those skilled in the art.

[0009] 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 provided for a right rear wheel (corresponding to a "right wheel") 91, and the second electric parking brake 3 is provided for a left rear wheel (corresponding to a "left wheel") 92. The first electric parking brake 2 and the second electric parking brake 3 may be provided for left and right front wheels 93, 94.

[0010] As shown in Fig. 2, the first electric parking brake 2 includes a first electric motor 21, a conversion mechanism 22, a linear motion member 23, a pair of brake pads 241, 242, and a caliper 25. The first electric motor 21 is a drive source of 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 a plurality of gears, and also functions as a reduction mechanism.

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

[0012] The caliper 25 is disposed relative to the wheel so as to straddle the disc rotor 8. A linear motion member 23 and brake pads 241, 242 are disposed on the caliper 25. The conversion mechanism 22 has a self-locking function (for example, a mechanism with zero reverse efficiency). Therefore, in a state where there is no driving force from the first electric motor 21, the linear motion member 23 is locked (fixed in position). The linear motion member 23 does not move in response to the 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 includes 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, a description of the configuration of the second electric parking brake 3 will be omitted. Well-known electric brakes are applied as the first electric parking brake 2 and the second electric parking brake 3.

[0014] The battery 4 is a power source and supplies power to the first electric motor 21 and the second electric motor 31 under the control of the controller 5. The vehicle is equipped with wheel speed sensors 71 installed for each of the wheels 91-94, an acceleration sensor 72 for detecting acceleration in the front-rear direction, a position sensor 73 for detecting the position of the shift lever, and the like. The various sensors 71, 72, 73 transmit the detection results to the controller 5. Communications within the vehicle are carried out by CAN (car area network or controllable area network).

[0015] The controller 5 controls a first control current supplied from the battery 4 to the first electric motor 21, and a second control current supplied from the battery 4 to the second electric motor 31. When the parking brake is turned on by a user operating an operating member (e.g., operating a button), the controller 5 supplies the first control current to the first electric motor 21 by connecting the battery 4 and the first electric motor 21, and supplies the second control current to the second electric motor 31 by connecting the battery 4 and the second electric motor 31.

[0016] The controller 5 includes an ECU 51, a first switching unit 52, and a second switching unit 53. The ECU 51 is an electronic control unit that includes one or more processors and one or more memories, and 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 (conduction) and off (disconnection). 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 (conduction) and off (disconnection). The ECU 51 controls the on / off 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 (conduction / disconnection) according to the control of the ECU 51. 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 "conduction" and "off" means "disconnection."

[0017] In the 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, keeps them on until a predetermined braking force is generated, and turns them off after the predetermined braking force is generated. The ECU 51 may selectively execute the normal control and the peak adjustment control described later depending on the situation.

[0018] The vehicle (or the controller 5) is provided with current detection units 541, 542 and a voltage detection unit 55. The current detection units 541, 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, 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 regulation control) The controller 5 is configured to execute a "peak adjustment control" for controlling the first control current and the second control current so that the peaks of the first control current and the second control current alternately appear multiple times when the electric parking brakes 2 and 3 are started. The peak is a point where an increase switches to a decrease, and can also be called a maximum value. For example, as shown in FIG. 3 (upper side), when supplying power to the first electric motor 21 and the second electric motor 31, the controller 5 controls the first control current and the second control current so that the peaks of the control currents appear in the order of a peak P11 of one control current, a peak P21 of the other control current, a peak P12 of one control current, and a peak P22 of the other control current. 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), the ECU 51 executes an "alternate on / off process" multiple times to activate both electric parking brakes 2 and 3, in which the ECU 51 turns on the first switching unit 52 (one switching unit) and then turns on the second switching unit 53 (the other switching unit), and turns off the first switching unit 52 and then turns off the second switching unit 53. That is, the ECU 51 shifts the on / off timing of the two switching units 52 and 53. For example, the intervals at which the peaks appear can be the same for the first control current and the second control current. According to this alternating on / off process, a peak appears in the first control current (one control current), and then a peak appears in the second control current (the other control current). By executing this alternating on / off process multiple times, the peaks of the first control current and the second control current appear alternately multiple times. That is, the peak adjustment control is executed by multiple alternating on / off processes.

[0021] In the alternating on / off process, for example, the ECU 51 may turn on one of the switching units 52, 53 in accordance with turning off the other switching unit 52, 53. In other words, in the alternating on / off process, turning on one and turning off the other may be executed simultaneously. In this manner, the ECU 51 may turn off the second switching unit 53 in accordance with turning on the first switching unit 52, and turn on the second switching unit 53 in accordance with turning off the first switching unit 52, during at least a part of the period during which the peak adjustment control is being executed. The ECU 51 may simultaneously turn on one and turn off the other during the entire period of the peak adjustment control (may exclude the initial on).

[0022] The ECU 51 keeps each of the switching units 52, 53 on after causing each control current to peak a predetermined number of times. Each control current gradually decreases while causing a peak to appear depending on whether it is on or off, and becomes a steady current after each of the switching units 52, 53 is kept on. The on / off of each of the switching units 52, 53 is controlled so that each control current has a peak a number of times before it becomes a steady current. In other words, the on / off switching of each of the switching units 52, 53 is performed at high speed.

[0023] After each control current becomes a steady current, it increases according to the generation of a braking force of the corresponding wheel. When the brake pad 241 abuts against the disc rotor 8 and a braking force starts to be generated, the braking force increases according to 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 unit 52, 53. Even if the power supply to the electric motors 21, 31 is stopped, the braking force is maintained due to the self-locking function of the conversion mechanism 22. When the braking force of the electric parking brakes 2, 3 is released (when the lock is released), the controller 5 rotates the first electric motor 21 and the second electric motor 31 in the reverse direction.

[0024] As another example of the peak adjustment control, when power supply to the electric parking brakes 2, 3 starts, the first switching unit 52 and the second switching unit 53 may be simultaneously turned on, and one control current 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 current is adjusted, for example, by setting an ECU circuit constant (hardware) or a control constant (software). In this way, the ECU 51 controls each control current so that the slope of one control current differs from the slope of the other control current, thereby making it possible to shift the peaks of the two control currents from each other.

[0025] The flow of the peak adjustment control will be described with reference to Fig. 4 and Fig. 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, 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. That is, the controller 5 is set in the peak adjustment control so that the increasing gradient of the rising of the second control current is smaller than the increasing gradient of the rising of the first control current.

[0026] The ECU 51 has a time measurement function (also referred to as a time count function or a timer function). For example, the ECU 51 measures the elapsed time using as a trigger 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 the elapsed time using as a trigger the first on of at least one of the first switching unit 52 and the second switching unit 53 after the parking brake is turned on by the user.

[0027] When a predetermined time In1 has elapsed from the time (time t0) when the first switching unit 52 and the second switching unit 53 are turned on and it becomes time t1 (S102: Yes), the ECU 51 turns off the first switching unit 52 and keeps the second switching unit 53 on (S103). That is, 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 turning-off of the first switching unit 52 (time t1) and it becomes 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 in an on state and turning on an electric motor in an off state is also referred to as an "on-off reversal process." Note that the predetermined time In1 and the predetermined time In2 may be set to the same value.

[0029] The ECU 51 determines whether a predetermined end time In3 has elapsed since 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 reversal process (S107). If the predetermined time In2 has elapsed since the previous on / off reversal process (time t2) and time t3 has arrived (S107: Yes), the ECU 51 returns to step S103 and executes the on / off reversal process again (S103). If the predetermined time In2 has elapsed since time t3 and time t4 has arrived (S104: Yes), the ECU 51 executes the on / off reversal process again (S105).

[0030] When the end time In3 has elapsed from time t0 and it becomes time t5 (S106: Yes), the ECU 51 ends the peak adjustment control and turns on both the switching units 52, 53 (S108). As a result, each control current thereafter does not have a peak or has a peak and then decreases toward the current value of the steady current. After that, the first control current becomes a steady current, and then the second control current becomes a steady current. When the first electric parking brake 2 starts to generate a braking force on the wheels, the first control current starts to gradually increase. After that, when the second electric parking brake 3 starts to generate a braking force on the wheels, the second control current starts to gradually increase. The predetermined times In1, In2 and the 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 current and reaches a predetermined threshold, the ECU 51 determines that the wheel corresponding to the 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 ends the 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 ends the control of the second electric motor 31 (S110). Note that since the ECU 51 monitors each control current, steps S109 and S111 are actually executed simultaneously. According to the peak adjustment control, the time required for the wheels to lock is slightly longer than that according to the normal control.

[0033] According to this embodiment, the peak timing is shifted between the left and right electric motors 21 and 31 by the peak adjustment control, and the control current output from the battery 4 is leveled. In addition, multiple peaks appear in each control current by the peak adjustment control. Therefore, the inrush current generated by the peak adjustment control is lower than the inrush current generated by the normal control. These actions suppress a sudden voltage drop of the battery 4 due to the inrush current when each electric parking brake is operated. Therefore, according to this embodiment, even if the power supply voltage (the voltage of the battery 4) is reduced for some reason, the voltage (system required voltage) required for the operation of the electric parking brakes 2 and 3 is easily maintained. In other words, according to this embodiment, the system can be operated continuously more stably, and the electric parking brakes 2 and 3 can be appropriately operated even if the time until locking is slightly increased. The state in which the voltage of the battery 4 is reduced includes, for example, a state in which the battery 4 is deteriorated, or a state in which the battery 4 is deteriorated and the temperature is low, such as a winter morning. Even in such a state, according to this embodiment, the parking brake can be operated.

[0034] In addition, by simultaneously turning on one control current and turning off the other control current as in this embodiment, the timing of the peak (maximum value) of one current and the timing of the minimum value of the other current can be synchronized, thereby making it possible to more even out the total control current.

[0035] (others) The present invention is not limited to the above embodiment. For example, as shown in the balloon in FIG. 4, the controller 5 may also execute the peak adjustment control when the control current starts to increase from the steady current. In this case, for example, when the ECU 51 detects that the first control current has increased through the steady current, it executes the on / off process so that multiple peaks appear. Also, when the ECU 51 detects that the second control current has increased through the steady current, it controls the second control current so that the peaks of the first control current and the second control current appear alternately, thereby executing the peak adjustment control. When both control currents increase from the steady current, the ECU 51 executes the peak adjustment control, for example, by the alternating on / off process. In this way, when starting the operation of the electric parking brakes 2 and 3, the controller 5 executes the peak adjustment control for an initial predetermined period, then ends the peak adjustment control, and executes the peak adjustment control again when the first control current and the second control current increase from the steady current. This also suppresses a sudden increase in the control current when the braking force starts to be generated on the wheels. As the wheels approach a locked state, the voltage of the battery 4 gradually decreases due to the use of electric power. However, with this configuration, it is possible to level out the inrush current when the braking force is generated, and it is also possible to suppress a system stop near the lock. The ECU 51 may previously calculate (estimate) a difference in the timing of starting to increase the first control current and the second control current when the wheels are locked, based on the detection results of the current detection units 541 and 542.

[0036] Furthermore, when the controller 5 detects that the vehicle is moving (sliding) based on the detection result of the wheel speed sensor 71 or the like during execution of the peak adjustment control, the controller 5 may stop the peak adjustment control and execute normal control. The normal control is a control in which the switching units 52, 53 are kept in the on state until the wheels are locked. In this way, when the vehicle starts to slide, the braking force on the wheels can be increased quickly by the normal control.

[0037] Also, the controller 5 may execute the peak adjustment control only when an execution condition for the peak adjustment control is satisfied. The execution condition is set to, for example, "the voltage of the battery 4 is less than a predetermined value" and / or "the shift lever is in the parking position". Also, the execution condition may include "the gradient of the road surface at the vehicle position is within a predetermined range". For example, as shown in FIG. 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 less than a predetermined value (S202: Yes), the ECU 51 determines whether 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 condition is satisfied and executes the peak adjustment control in response to the on of the parking brake (S204).

[0038] When the shift lever is not in the parking position (S203: No), the ECU 51 determines whether the gradient of the road surface at the vehicle position (stopped position) is within a predetermined range (-α<gradient<β) (S205). When the gradient of the road surface is within the predetermined range (S205: Yes), the ECU 51 determines that the execution condition is satisfied, and executes the peak adjustment control in response to the parking brake being turned on (S204). When the gradient of the road surface is not within the predetermined range (S205: No), the ECU 51 determines that the execution condition is not satisfied, and executes the normal control in response to the parking brake being turned on (S206). Also, when the voltage of the battery 4 is equal to or higher than a predetermined value (S202: No), the ECU 51 determines that the execution condition is not satisfied, and executes the normal control in response to the parking brake being turned on (S206). The determination of the execution condition may be performed periodically when the parking brake is turned off, or may be performed when the parking brake is turned on.

[0039] In this way, the ECU 51 is configured to selectively execute normal control, in which the first switching unit 52 is maintained 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 is maintained 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 be configured to execute the peak adjustment control only when an execution condition for the peak adjustment control is satisfied. In other words, the controller 5 may be configured to selectively execute the normal control and the peak adjustment control depending on the voltage of the battery 4, the position of the shift lever, etc. (depending on the determination result of the execution condition). This enables control that is more suited to the situation.

[0040] In addition, even if the peak adjustment control is executed, there may be a case where the timing of the peaks of the control currents becomes closer to each other due to, for example, variations in the wiring resistance of the vehicle caused by aging. When the ECU 51 detects that the appearance interval between the peaks of the first control current and the peaks of the second control current becomes less than a predetermined threshold based on the detection results of the current detection units 541 and 542, the ECU 51 may shift the on / off timing of one of the switching units 52 and 53 by a predetermined value so that the appearance interval becomes wider. In this case, the ECU 51 may advance the on / off timing of one of the switching units 52 and 53 by a predetermined value. Such an adjustment may be performed one or more times until the appearance interval from one peak to the other peak becomes equal to or greater than 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. The electric parking brakes 2, 3 may have other known configurations, such as drum types. The parking brakes may be turned on and off automatically (for example, during autonomous driving) and not necessarily by user operation. The determination of whether the wheels are locked may be performed by a known method and not limited to the above. [Explanation of symbols]

[0042] 1...electric brake 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 provided for one of the right and left wheels and driven by a first electric motor; a second electric parking brake provided for the other of the right wheel and the left wheel and driven by a second electric motor; a DC power supply unit for supplying 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 controller: and executing peak adjustment control for controlling the first control current and the second control current so that peaks of the first control current and peaks of the second control current alternately appear multiple times when starting operation of the first electric parking brake and the second electric parking brake. Electric brake system.

2. the controller is set so that, in the peak adjustment control, an increase gradient of the rising edge of the second control current is smaller than an increase gradient of the rising edge of the first control current. The electric brake system according to claim 1 .

3. The controller: a first switching unit that switches a connection state between the DC power supply unit and the first electric motor between on and off; a second switching unit that switches a connection state between the DC power supply unit and the second electric motor between on and off; An ECU that controls on / off of the first switching unit and the second switching unit; Equipped with The ECU executes an alternating on / off process a plurality of times in the peak adjustment control, in which the ECU turns on the first switching unit and then turns on the second switching unit, and turns off the first switching unit and then turns off the second switching unit. The electric brake system according to claim 1 .

4. The controller: When starting operation of the first electric parking brake and the second electric parking brake, the peak adjustment control is executed for an initial predetermined period, and then the peak adjustment control is terminated. When the first control current and the second control current increase from the steady-state current, the peak adjustment control is executed again. The electric brake system according to claim 1 .

5. The controller: a first switching unit that switches a connection state between the DC power supply unit and the first electric motor between on and off; a second switching unit that switches a connection state between the DC power supply unit and the second electric motor between on and off; An ECU that controls on / off of the first switching unit and the second switching unit; Equipped with The ECU turns off the second switching unit in accordance with the on-state of the first switching unit and turns on the second switching unit in accordance with the off-state of the first switching unit during at least a part of a period during which the peak adjustment control is being performed. The electric brake system according to any one of claims 1 to 4.

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