Motor control device

Abstract

To provide a motor control device capable of preventing a parking brake device from becoming inoperable.SOLUTION: A braking control device 100 includes: an inverter circuit 120 that drives a brushless motor 52; a first drive circuit 130 that drives a first brush motor 71R; and a redundant circuit 150 that drives a first brush motor 71 via the inverter circuit 120. The redundant circuit 150 includes: a first connection line 151 that connects a DC power source 90 and one of power source terminals of the first brush motor 71R; a second connection line 152 that connects a connection point of an upper-stage switching element 124 and a lower-stage switching element 125 in a first phase circuit 121 of the inverter circuit 120 and the other power source terminal of the first brush motor 71R; and a first switching element 161 provided on the first connection line 151.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a motor control device.

Background Art

[0002] Patent Document 1 describes an electric power steering apparatus including a brushless motor for electric power steering, a brush motor for adjusting the position of a steering wheel, and a motor control device for controlling both motors. The motor control device has an inverter circuit that supplies power to the brushless motor and a power supply circuit that supplies power to the brush motor via the inverter circuit. The motor control device supplies power only to the brushless motor or only to the brush motor by switching on and off the switching elements constituting the inverter circuit or by switching on and off the switches constituting the power supply circuit.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the motor control device as described above, when the switch constituting the power supply circuit malfunctions, power cannot be supplied to the brush motor. Therefore, when the brushless motor is adopted as the power source of the electric brake and the brush motor is adopted as the power source of the parking brake, the following problems may occur. That is, when the switch constituting the power supply circuit malfunctions, there is a possibility that the electric parking brake cannot be operated.

Means for Solving the Problems

[0005] The motor control device for solving the above problems is a motor control device that controls a brushless motor which is a power source of an electric brake device for applying a braking force to a wheel, and a brushed motor which is a power source of a parking brake device for applying a braking force to the wheel. The motor control device includes an inverter circuit for driving the brushless motor, a drive circuit for driving the brushed motor, and a redundant circuit for driving the brushed motor via the inverter circuit. The inverter circuit has a first-phase circuit, a second-phase circuit, and a third-phase circuit that are connected in parallel to each other and connected to a DC power supply. Each of the first-phase circuit, the second-phase circuit, and the third-phase circuit includes an upper switching element and a lower switching element that are connected in series. The redundant circuit includes a first connection line connecting the DC power supply and one power supply terminal of the brushed motor, a second connection line connecting a connection point of the upper switching element and the lower switching element in one of the first-phase circuit, the second-phase circuit, and the third-phase circuit and the other power supply terminal of the brushed motor, and a first switching element provided on the first connection line.

[0006] The motor control device for solving the above problems includes a brushless motor which is a power source of an electric brake device that applies braking force to a first wheel and a second wheel, a first brushed motor which is a power source of a first parking brake device that applies braking force to the first wheel, and a second brushed motor which is a power source of a second parking brake device that applies braking force to the second wheel. The motor control device controls the brushless motor, a first drive circuit that drives the first brushed motor, a second drive circuit that drives the second brushed motor, and a redundant circuit that drives the first brushed motor and the second brushed motor via the inverter circuit. The inverter circuit has a first phase circuit, a second phase circuit, and a third phase circuit that are connected in parallel to each other and connected to a DC power supply. Each of the first phase circuit, the second phase circuit, and the third phase circuit includes an upper switching element and a lower switching element that are connected in series. The redundant circuit includes a first connection line that connects the DC power supply and one power supply terminal of the first brushed motor, a second connection line that connects a connection point of the upper switching element and the lower switching element in one of the first phase circuit, the second phase circuit, and the third phase circuit and the other power supply terminal of the first brushed motor, a first switching element provided on the first connection line, a third connection line that connects the DC power supply and one power supply terminal of the second brushed motor, a fourth connection line that connects a connection point of the upper switching element and the lower switching element in one of the first phase circuit, the second phase circuit, and the third phase circuit and the other power supply terminal of the second brushed motor, and a third switching element provided on the third connection line.

Effect of the Invention

[0007] The motor control device can suppress the inability to operate the parking brake device.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

BEST MODE FOR CARRYING OUT THE INVENTION

[0009] (First Embodiment) A first embodiment of a vehicle equipped with a braking control device as an example of a "motor control device" will be described with reference to the drawings.

[0010] <Configuration of the First Embodiment> As shown in FIG. 1, the vehicle 10 includes a plurality of wheels 20, an electric brake device 30, a plurality of parking brake devices 70, a brake operation member 80, a DC power supply 90, and a braking control device 100. The vehicle 10 also includes a brake sensor SE1, a state detection unit SE2, and a parking switch SW1.

[0011] The vehicle 10 is a four-wheel vehicle. FIG. 1 shows only the right rear wheel 20R and the left rear wheel 20L among the four wheels 20 provided in the vehicle 10. The right rear wheel 20R corresponds to the "first wheel", and the left rear wheel 20L corresponds to the "second wheel". Also, an example of the brake operation member 80 is a brake pedal.

[0012] <Electric Brake Device> The electric brake device 30 is a brake device that applies a braking force to the wheels 20 based on the operation of the brake operation member 80. In this regard, the electric brake device 30 can also be referred to as a service brake device. The electric brake device 30 includes a plurality of braking mechanisms 40, a hydraulic pressure generating unit 50, and a pressure regulating unit 60.

[0013] The plurality of braking mechanisms 40 are respectively provided so as to correspond to the plurality of wheels 20. For example, a braking mechanism 40 for the right rear wheel 20R is provided for the right rear wheel 20R, and a braking mechanism 40 for the left rear wheel 20L is provided for the left rear wheel 20L. The braking mechanism 40 includes a rotating body 41 that rotates integrally with the wheel 20, a friction material 42 that applies a braking force corresponding to the friction with the rotating body 41, a piston 43 that moves the friction material 42 with respect to the rotating body 41, and a wheel cylinder 44 that houses the piston 43. There is a hydraulic chamber 45 filled with brake fluid between the piston 43 and the wheel cylinder 44. The piston 43 is movable with respect to the wheel cylinder 44 in a direction to change the volume of the hydraulic chamber 45. In the following description, among the moving directions of the piston 43, the direction in which the volume of the hydraulic chamber 45 is increased is referred to as the forward direction X1, and the direction in which the volume of the hydraulic chamber 45 is decreased is referred to as the backward direction X2. The wheel cylinder 44 has a communication hole 46 that communicates with the hydraulic chamber 45.

[0014] When brake fluid is supplied to the hydraulic chamber 45 through the communication hole 46, the hydraulic pressure in the hydraulic chamber 45 increases. In this case, since the piston 43 moves in the forward direction X1, the force with which the piston 43 presses the friction material 42 against the rotating body 41 increases. As a result, the braking force applied to the wheel 20 increases. On the other hand, when the brake fluid is discharged from the hydraulic chamber 45 through the communication hole 46, the hydraulic pressure in the hydraulic chamber 45 decreases. In this case, since the piston 43 moves in the backward direction X2, the force with which the piston 43 presses the friction material 42 against the rotating body 41 decreases. As a result, the braking force applied to the wheel 20 decreases. In this way, the braking mechanism 40 applies a braking force corresponding to the hydraulic pressure in the hydraulic chamber 45 to the wheel 20.

[0015] The hydraulic pressure generating unit 50 includes a hydraulic pressure generating mechanism 51 that generates hydraulic pressure, and a brushless motor 52 that is a power source for the hydraulic pressure generating mechanism 51. The brushless motor 52 is a three-phase motor having a first-phase coil, a second-phase coil, and a third-phase coil. Based on the power transmitted from the brushless motor 52, the hydraulic pressure generating mechanism 51 sends out the brake fluid toward the pressure regulating unit 60 or sucks in the brake fluid from the pressure regulating unit 60. The hydraulic pressure generating mechanism 51 has a configuration including, for example, an electric pump or an electric cylinder using the brushless motor 52 as a power source.

[0016] The pressure regulating unit 60 is connected to the hydraulic pressure generating unit 50 and the communication holes 46 of the plurality of braking mechanisms 40. Although not shown, the pressure regulating unit 60 includes a plurality of flow paths through which the brake fluid flows, and a plurality of solenoid valves that open and close the plurality of flow paths. Then, the pressure regulating unit 60, together with the hydraulic pressure generating unit 50, adjusts the hydraulic pressure in the hydraulic pressure chamber 45 of the braking mechanism 40 for the right rear wheel 20R and the hydraulic pressure in the hydraulic pressure chamber 45 of the braking mechanism 40 for the left rear wheel 20L. For example, the pressure regulating unit 60 changes the hydraulic pressure in the hydraulic pressure chamber 45 of the braking mechanism 40 for the right rear wheel 20R and the hydraulic pressure in the hydraulic pressure chamber 45 of the braking mechanism 40 for the left rear wheel 20L in the same manner. Also, the pressure regulating unit 60 generates a differential pressure between the hydraulic pressure in the hydraulic pressure chamber 45 of the braking mechanism 40 for the right rear wheel 20R and the hydraulic pressure in the hydraulic pressure chamber 45 of the braking mechanism 40 for the left rear wheel 20L.

[0017] <Parking Brake Device> The parking brake device 70 is a brake device that applies a braking force to the wheels 20 based on the operation of the parking switch SW1. In the first embodiment, the parking brake device 70 shares a part of the configuration with the braking mechanism 40 in the electric brake device 30. That is, the parking brake device 70 is integrated with the electric brake device 30. In other embodiments, the parking brake device 70 may have a configuration independent of the electric brake device 30.

[0018] A plurality of parking brake devices 70 are respectively provided so as to correspond to a plurality of wheels 20. Specifically, a first parking brake device 70R for the right rear wheel 20R is provided on the right rear wheel 20R, and a second parking brake device 70L for the left rear wheel 20L is provided on the left rear wheel 20L. In other embodiments, the parking brake device 70 may be provided on at least one of the plurality of wheels 20.

[0019] The parking brake device 70 includes a brush motor 71 which is a power source of the parking brake device 70, and a linear motion conversion mechanism 72 which transmits the power transmitted from the brush motor 71 to the piston 43 of the braking mechanism 40. The linear motion conversion mechanism 72 includes a rotating member 73 which rotates based on the power transmitted from the brush motor 71, and a linear motion member 74 which linearly moves in the forward direction X1 or the backward direction X2 according to the rotation of the rotating member 73. The rotating member 73 penetrates the bottom of the wheel cylinder 44 of the braking mechanism 40. The linear motion member 74 is disposed inside the hydraulic chamber 45 so as to be able to press the piston 43 in the forward direction X1. The parking brake device 70 may have a speed reduction mechanism between the brushless motor 52 and the linear motion conversion mechanism 72. Further, it is preferable that the linear motion conversion mechanism 72 has a self-locking function such that the rotating member 73 does not rotate even when the rotating member 73 is stopped and a load acts on the linear motion member 74 in the forward direction X1 or the backward direction X2.

[0020] In the following description, the brush motor 71 of the first parking brake device 70R is also referred to as the first brush motor 71R, and the brush motor 71 of the second parking brake device 70L is also referred to as the second brush motor 71L.

[0021] When the vehicle 10 is stopped, that is, when the wheels 20 are not rotating, if the rotating member 73 rotates in one rotation direction (hereinafter referred to as the "forward direction"), the linear motion member 74 moves in the forward direction X1. Then, via the piston 43, the friction material 42 is pressed against the rotating body 41, thereby applying a braking force to the wheel 20. On the other hand, when the rotating member 73 rotates in the direction opposite to the forward direction, the linear motion member 74 moves in the backward direction X2, which is the direction opposite to the forward direction X1. Then, since the friction material 42 separates from the rotating body 41, the braking force applied to the wheel 20 is canceled. In the following description, in the parking brake device 70, applying a braking force to the wheel 20 is referred to as a "lock operation", and canceling the braking force applied to the wheel 20 is referred to as a "release operation". In this regard, the parking brake device 70 performs a lock operation and a release operation according to the rotation direction of the output shaft of the brush motor 71.

[0022] <Braking control device> As shown in FIGS. 1 and 2, the braking control device 100 includes a motor control circuit 110 and a braking control unit 170.

[0023] <Motor control circuit> As shown in FIG. 2, the motor control circuit 110 includes an inverter circuit 120, a first drive circuit 130, a second drive circuit 140, and a redundant circuit 150.

[0024] The inverter circuit 120 is a circuit for driving the brushless motor 52. The inverter circuit 120 is provided between the DC power supply 90 and the ground GND. The inverter circuit 120 has a first-phase circuit 121, a second-phase circuit 122, and a third-phase circuit 123 that are connected in parallel to each other and connected to the DC power supply 90 and the ground GND. The first-phase circuit 121 includes switching elements 124 and 125 corresponding to the first-phase coil of the brushless motor 52. The second-phase circuit 122 includes switching elements 126 and 127 corresponding to the second-phase coil of the brushless motor 52. The third-phase circuit 123 includes switching elements 128 and 129 corresponding to the third-phase coil of the brushless motor 52.

[0025] The switching elements 124 to 129 of each phase are power switching elements such as MOSFETs, for example. The switching elements 124, 126, and 128 are connected to the DC power supply 90. The switching elements 125, 127, and 129 are respectively arranged between the switching elements 124, 126, 128 and the ground GND. That is, the switching elements 124, 126, and 128 correspond to the "upper switching elements", and the switching elements 125, 127, and 129 correspond to the "lower switching elements".

[0026] Then, the inverter circuit 120 converts the DC power output by the DC power supply 90 into AC power by switching the on / off states of the plurality of switching elements 124 to 129. In this way, the inverter circuit 120 drives the brushless motor 52.

[0027] The first drive circuit 130 is a circuit for driving the first brush motor 71R, and the second drive circuit 140 is a circuit for driving the second brush motor 71L. The first drive circuit 130 and the second drive circuit 140 are so-called H-bridge circuits. The first drive circuit 130 and the second drive circuit 140 are provided between the DC power supply 90 and the ground GND.

[0028] The first drive circuit 130 has four switching elements 131 to 134. The switching elements 131 to 134 are power switching elements such as MOSFETs, for example. The switching elements 131 and 132 are connected in series between the DC power supply 90 and the ground GND. Similarly, the switching elements 133 and 134 are connected in series between the DC power supply 90 and the ground GND. The connection point of the switching elements 131 and 132 is connected to one power supply terminal of the first brush motor 71R, and the connection point of the switching elements 133 and 134 is connected to the other power supply terminal of the first brush motor 71R. Then, the first drive circuit 130 switches the on / off states of the plurality of switching elements 131 to 134 to switch the direction of the current flowing through the first brush motor 71R or stop the power supply to the first brush motor 71R.

[0029] The second drive circuit 140 has a plurality of switching elements 141 to 144 corresponding to the plurality of switching elements 131 to 134 of the first drive circuit 130. The connection point of the switching elements 141 and 142 is connected to one power supply terminal of the second brush motor 71L, and the connection point of the switching elements 143 and 144 is connected to the other power supply terminal of the second brush motor 71L. Then, the second drive circuit 140 switches the on / off states of the plurality of switching elements 141 to 144 to switch the direction of the current flowing through the second brush motor 71L or stop the power supply to the second brush motor 71L.

[0030] The redundant circuit 150 has a first connection line 151, a second connection line 152, and a first switching element 161. The first connection line 151 connects the DC power supply 90 and one power supply terminal of the first brush motor 71R. The second connection line 152 connects the connection point of the upper switching element 124 and the lower switching element 125 of the first-phase circuit 121 and the other power supply terminal of the first brush motor 71R. The first switching element 161 is provided on the first connection line 151. The first switching element 161 is a power switching element such as a MOSFET, for example.

[0031] In FIG. 2, three DC power supplies 90 are illustrated, but the three DC power supplies 90 are the same DC power supply 90. In other embodiments, the vehicle 10 may include three DC power supplies 90 for supplying power to the inverter circuit 120, the first drive circuit 130, and the second drive circuit 140, respectively.

[0032] <Brake control unit> The brake control unit 170 is an electronic control device having a CPU and a memory. By the CPU executing a program stored in the memory, the voltage regulating unit 60 and the motor control circuit 110 are controlled.

[0033] A detection signal is output from a brake sensor SE1 that detects the operation amount of the brake operation member 80 to the brake control unit 170. The brake control unit 170 determines the presence or absence of a braking request from the driver and calculates the required braking force requested by the driver based on the detection signal of the brake sensor SE1. Then, when there is a braking request from the driver, the brake control unit 170 controls the inverter circuit 120 in the motor control circuit 110 based on the required braking force.

[0034] For example, when the required braking force increases, the brake control unit 170 rotates the brushless motor 52 in one rotation direction (hereinafter referred to as the "forward direction") through the voltage regulating unit 60 so that the brake fluid flows into the braking mechanism 40. In this case, as the piston 43 of the braking mechanism 40 moves in the forward direction X1, the force with which the friction material 42 presses the rotating body 41 increases. That is, the braking force applied to the wheel 20 increases. On the other hand, when the required braking force decreases, the brake control unit 170 rotates the brushless motor 52 in the direction opposite to the forward direction through the voltage regulating unit 60 so that the brake fluid flows out of the braking mechanism 40. In this case, as the piston 43 of the braking mechanism 40 moves in the backward direction X2, the force with which the friction material 42 presses the rotating body 41 decreases. That is, the braking force applied to the wheel 20 decreases. In this way, the brake control unit 170 adjusts the braking force applied to the wheel 20 by driving the brushless motor 52.

[0035] A detection signal is output from a state detection unit SE2 that detects the states of the first drive circuit 130 and the second drive circuit 140 to the braking control unit 170. Based on the detection signal output from the state detection unit SE2, the braking control unit 170 determines whether the first drive circuit 130 and the second drive circuit 140 are functioning properly. The state detection unit SE2 may be, for example, a rotation angle sensor that detects the rotation angles of the first brush motor 71R and the second brush motor 71L, or a current sensor that detects the current flowing through the first drive circuit 130 and the second drive circuit 140. When such a state detection unit SE2 is employed, if the rotation angle of the first brush motor 71R does not change even when the on / off states of the switching elements 131 to 134 of the first drive circuit 130 are switched so that current flows through the first brush motor 71R, the braking control unit 170 may determine that the first drive circuit 130 is not functioning properly. Also, if no current flows through the first drive circuit 130 even when the on / off states of the switching elements 131 to 134 of the first drive circuit 130 are switched so that current flows through the first brush motor 71R, the braking control unit 170 may determine that the first drive circuit 130 is not functioning properly. The same applies to the case of determining whether the second drive circuit 140 is functioning properly.

[0036] When an operation signal indicating that the parking switch SW1 has been turned on is output under the condition that both the first drive circuit 130 and the second drive circuit 140 are functioning properly, the braking control unit 170 causes the parking brake device 70 to perform a locking operation. Specifically, the braking control unit 170 controls a plurality of switching elements 131 to 134 and 141 to 144 of the first drive circuit 130 and the second drive circuit 140 in the motor control circuit 110. In this way, the braking control unit 170 applies a braking force to the wheels 20 by rotating the brush motor 71 of the parking brake device 70 in the forward direction.

[0037] On the one hand, when an operation signal indicating that the parking switch SW1 has been turned off is output under the situation where both the first drive circuit 130 and the second drive circuit 140 are functioning normally, the braking control unit 170 causes the parking brake device 70 to perform a release operation. Specifically, the braking control unit 170 controls a plurality of switching elements 131 to 134 and 141 to 144 of the first drive circuit 130 and the second drive circuit 140 in the motor control circuit 110. In this way, the braking control unit 170 eliminates the braking force applied to the wheels 20 by rotating the brush motor 71 of the parking brake device 70 in the reverse direction.

[0038] When an operation signal indicating that the parking switch SW1 has been turned on is output under the situation where the first drive circuit 130 is not functioning normally, the braking control unit 170 causes the first parking brake device 70R to perform a locking operation. In this case, the braking control unit 170 controls the inverter circuit 120 and the redundant circuit 150 instead of the first drive circuit 130 that is not functioning normally. Specifically, the braking control unit 170 turns on the switching element 125 at the lower stage of the first-phase circuit 121 in the inverter circuit 120 and turns on the first switching element 161 of the redundant circuit 150. In this way, the braking control unit 170 rotates the first brush motor 71R of the first parking brake device 70R in the forward direction via the inverter circuit 120 and the redundant circuit 150.

[0039] In the first embodiment, the redundant circuit 150 can supply power to the first brush motor 71R via the inverter circuit 120, but cannot supply power to the second brush motor 71L via the inverter circuit 120. For this reason, when an operation signal indicating that the parking switch SW1 has been turned on is output under the situation where the second drive circuit 140 is not functioning normally, the braking control unit 170 does not cause the second parking brake device 70L to perform a locking operation.

[0040] <Actions and Effects of the First Embodiment> The actions and effects of the braking control device 100 when parking the vehicle 10 will be described. When parking the vehicle 10 in operation, the driver turns on the parking switch SW1. When the first drive circuit 130 is functioning normally, the first drive circuit 130 drives the first brush motor 71R of the first parking brake device 70R to perform a locking operation. Also, when the second drive circuit 140 is functioning normally, the second drive circuit 140 drives the second brush motor 71L of the second parking brake device 70L to perform a locking operation.

[0041] On the other hand, when the first drive circuit 130 is not functioning normally, the inverter circuit 120 and the redundant circuit 150 drive the first brush motor 71R of the first parking brake device 70R to perform a locking operation. Therefore, even when the first drive circuit 130 stops functioning normally, the braking control device 100 can prevent the first parking brake device 70R from being unable to perform a locking operation. That is, the braking control device 100 can apply a braking force to the right rear wheel 20R by the first parking brake device 70R.

[0042] (Second Embodiment) The braking control device 100A according to the second embodiment will be described with reference to the drawings. <Configuration of the Second Embodiment> The braking control device 100A according to the second embodiment has a different configuration of the motor control circuit 110A when compared with the braking control device 100 according to the first embodiment. Therefore, in the following description, the same reference numerals will be given to the configurations common to the first embodiment and the description thereof will be omitted.

[0043] As shown in FIG. 3, the braking control device 100A includes a motor control circuit 110A. The motor control circuit 110A includes an inverter circuit 120, a first drive circuit 130, a second drive circuit 140, and a redundant circuit 150A. The redundant circuit 150A includes a first connection line 151, a second connection line 152, a first ground connection line 155, a first switching element 161, and a second switching element 162. The first ground connection line 155 connects a portion between the first switching element 161 and one power terminal of the brush motor 71 in the first connection line 151 to the ground GND. The second switching element 162 is provided on the first ground connection line 155. The second switching element 162 is a power switching element such as a MOSFET, for example.

[0044] When an operation signal indicating that the parking switch SW1 is turned on is output in a situation where the first drive circuit 130 is not functioning properly, the braking control unit 170 causes the first parking brake device 70R to perform a locking operation in the same manner as in the first embodiment.

[0045] On the other hand, when an operation signal indicating that the parking switch SW1 is turned off is output in a situation where the first drive circuit 130 is not functioning properly, the braking control unit 170 causes the first parking brake device 70R to perform a release operation. In this case, the braking control unit 170 controls the inverter circuit 120 and the redundant circuit 150A instead of the first drive circuit 130 that is not functioning properly. Specifically, the braking control unit 170 turns on the upper switching element 124 of the first-phase circuit 121 in the inverter circuit 120 and turns on the second switching element 162 of the redundant circuit 150A. In this way, the braking control unit 170 rotates the first brush motor 71R of the first parking brake device 70R in the reverse direction via the inverter circuit 120 and the redundant circuit 150A.

[0046] <Operations and Effects of the Second Embodiment> When parking the vehicle 10 in operation, the driver turns on the parking switch SW1. When the first drive circuit 130 is functioning properly, the first drive circuit 130 drives the first brush motor 71R of the first parking brake device 70R, thereby performing the locking operation of the first parking brake device 70R. On the other hand, when the first drive circuit 130 is not functioning properly, the inverter circuit 120 and the redundant circuit 150A drive the first brush motor 71R of the first parking brake device 70R, thereby performing the locking operation of the first parking brake device 70R.

[0047] When starting the operation of the parked vehicle 10, the driver turns off the parking switch SW1. When the first drive circuit 130 is functioning properly, the first drive circuit 130 drives the first brush motor 71R of the first parking brake device 70R, thereby performing the release operation of the first parking brake device 70R. On the other hand, when the first drive circuit 130 is not functioning properly, the inverter circuit 120 and the redundant circuit 150A drive the first brush motor 71R of the first parking brake device 70R, thereby performing the release operation of the first parking brake device 70R.

[0048] Therefore, even when the first drive circuit 130 fails to function properly, the brake control device 100A can prevent the first parking brake device 70R from being unable to perform the locking operation and the release operation. That is, the brake control device 100A can apply a braking force to the right rear wheel 20R or cancel the application of the braking force to the right rear wheel 20R by the first parking brake device 70R.

[0049] (Third Embodiment) The brake control device 100B according to the third embodiment will be described with reference to the drawings. <Configuration of the Third Embodiment> When the braking control device 100B according to the third embodiment is compared with the braking control device 100 according to the first embodiment, the configuration of the motor control circuit 110B is different. Therefore, in the following description, the components common to the first embodiment are denoted by the same reference numerals and the description thereof is omitted.

[0050] As shown in FIG. 4, the braking control device 100B includes a motor control circuit 110B. The motor control circuit 110B includes an inverter circuit 120, a first drive circuit 130, a second drive circuit 140, and a redundant circuit 150B. The redundant circuit 150B includes a first connection line 151, a second connection line 152, a third connection line 153, a fourth connection line 154, a first switching element 161, and a third switching element 163.

[0051] The third connection line 153 connects the DC power supply 90 and one power supply terminal of the second brush motor 71L. The fourth connection line 154 connects the connection point of the upper switching element 126 and the lower switching element 127 in the second-phase circuit 122 and the other power supply terminal of the second brush motor 71L. The third switching element 163 is provided on the third connection line 153. The third switching element 163 is a power switching element such as a MOSFET, for example.

[0052] When the braking control unit 170 receives an operation signal indicating that the parking switch SW1 has been turned on under the condition that the first drive circuit 130 is not functioning properly, similar to the first embodiment, the braking control unit 170 causes the first parking brake device 70R to perform a locking operation. Also, when the braking control unit 170 receives an operation signal indicating that the parking switch SW1 has been turned on under the condition that the second drive circuit 140 is not functioning properly, the braking control unit 170 causes the second parking brake device 70L to perform a locking operation. In this case, the braking control unit 170 controls the inverter circuit 120 and the redundant circuit 150B instead of the second drive circuit 140 that is not functioning properly. Specifically, the braking control unit 170 turns on the switching element 127 at the lower stage of the second-phase circuit 122 in the inverter circuit 120 and turns on the third switching element 163 of the redundant circuit 150B. Thus, the braking control unit 170 rotates the second brush motor 71L of the second parking brake device 70L in the forward direction via the inverter circuit 120 and the redundant circuit 150B.

[0053] <Operation and Effect of the Third Embodiment> When parking the vehicle 10 during driving, the driver turns on the parking switch SW1. When the first drive circuit 130 is functioning properly, the first drive circuit 130 drives the first brush motor 71R of the first parking brake device 70R, thereby performing a locking operation of the first parking brake device 70R. Similarly, when the second drive circuit 140 is functioning properly, the second drive circuit 140 drives the second brush motor 71L of the second parking brake device 70L, thereby performing a locking operation of the second parking brake device 70L.

[0054] On the other hand, when the first drive circuit 130 is not functioning properly, the inverter circuit 120 and the redundant circuit 150B drive the first brush motor 71R of the first parking brake device 70R, thereby performing a locking operation of the first parking brake device 70R. Similarly, when the second drive circuit 140 is not functioning properly, the inverter circuit 120 and the redundant circuit 150B drive the second brush motor 71L of the second parking brake device 70L, thereby performing a locking operation of the second parking brake device 70L.

[0055] Therefore, even when the first drive circuit 130 fails to function properly, the brake control device 100B can prevent the first parking brake device 70R from failing to perform a locking operation. That is, the brake control device 100B can apply a braking force to the right rear wheel 20R by the first parking brake device 70R.

[0056] Also, even when the second drive circuit 140 fails to function properly, the brake control device 100B can prevent the second parking brake device 70L from failing to perform a locking operation. That is, the brake control device 100B can apply a braking force to the left rear wheel 20L by the second parking brake device 70L.

[0057] (Fourth Embodiment) The brake control device 100C according to the fourth embodiment will be described with reference to the drawings. <Configuration of the Fourth Embodiment> The brake control device 100C according to the fourth embodiment has a different configuration of the motor control circuit 110C when compared with the brake control devices 100, 100A, and 100B according to the first to third embodiments. Therefore, in the following description, the components common to the first to third embodiments are denoted by the same reference numerals and the description thereof is omitted.

[0058] As shown in FIG. 5, the braking control device 100C includes a motor control circuit 110C. The motor control circuit 110C includes an inverter circuit 120, a first drive circuit 130, a second drive circuit 140, and a redundant circuit 150C. The redundant circuit 150C includes a first connection line 151, a second connection line 152, a third connection line 153, a fourth connection line 154, a first ground connection line 155, a second ground connection line 156, a first switching element 161, a second switching element 162, a third switching element 163, and a fourth switching element 164. The second ground connection line 156 connects a portion of the third connection line 153 between the third switching element 163 and one power supply terminal of the second brush motor 71L to the ground GND. The fourth switching element 164 is provided on the second ground connection line 156. The fourth switching element 164 is a power switching element such as a MOSFET, for example.

[0059] When an operation signal indicating that the parking switch SW1 is turned on is output in a situation where the first drive circuit 130 is not functioning normally, the braking control unit 170 causes the first parking brake device 70R to perform a locking operation in the same manner as in the first embodiment. On the other hand, when an operation signal indicating that the parking switch SW1 is turned off is output in a situation where the first drive circuit 130 is not functioning normally, the braking control unit 170 causes the first parking brake device 70R to perform a release operation in the same manner as in the second embodiment.

[0060] When the parking switch SW1 outputs an operation signal indicating that it has been turned on under the condition that the second drive circuit 140 is not functioning properly, the braking control unit 170 causes the second parking brake device 70L to perform a locking operation, as in the second embodiment. On the other hand, when the parking switch SW1 outputs an operation signal indicating that it has been turned off under the condition that the second drive circuit 140 is not functioning properly, the braking control unit 170 causes the second parking brake device 70L to perform a release operation. In this case, the braking control unit 170 controls the inverter circuit 120 and the redundant circuit 150C, rather than the second drive circuit 140 that is not functioning properly. Specifically, the braking control unit 170 turns on the switching element 126 at the upper stage of the second-phase circuit 122 in the inverter circuit 120 and turns on the fourth switching element 164 of the redundant circuit 150C. In this way, the braking control unit 170 rotates the second brush motor 71L of the second parking brake device 70L in the reverse direction via the inverter circuit 120 and the redundant circuit 150C.

[0061] <Operation and Effect of the Fourth Embodiment> When parking the vehicle 10 during operation, the driver turns on the parking switch SW1. When the first drive circuit 130 is functioning properly, the first drive circuit 130 drives the first brush motor 71R of the first parking brake device 70R, thereby performing a locking operation of the first parking brake device 70R. Similarly, when the second drive circuit 140 is functioning properly, the second drive circuit 140 drives the second brush motor 71L of the second parking brake device 70L, thereby performing a locking operation of the second parking brake device 70L. On the other hand, when the first drive circuit 130 is not functioning properly, the inverter circuit 120 and the redundant circuit 150C drive the first brush motor 71R of the first parking brake device 70R, thereby performing a locking operation of the first parking brake device 70R. Similarly, when the second drive circuit 140 is not functioning properly, the inverter circuit 120 and the redundant circuit 150C drive the second brush motor 71L of the second parking brake device 70L, thereby performing a locking operation of the second parking brake device 70L.

[0062] When starting the operation of the parked vehicle 10, the driver turns off the parking switch SW1. When the first drive circuit 130 is functioning normally, the first drive circuit 130 drives the first brush motor 71R of the first parking brake device 70R, thereby performing the release operation of the first parking brake device 70R. Similarly, when the second drive circuit 140 is functioning normally, the second drive circuit 140 drives the second brush motor 71L of the second parking brake device 70L, thereby performing the release operation of the second parking brake device 70L. On the other hand, when the first drive circuit 130 is not functioning normally, the inverter circuit 120 and the redundant circuit 150C drive the first brush motor 71R of the first parking brake device 70R, thereby performing the release operation of the first parking brake device 70R. Similarly, when the second drive circuit 140 is not functioning normally, the inverter circuit 120 and the redundant circuit 150C drive the second brush motor 71L of the second parking brake device 70L, thereby performing the release operation of the second parking brake device 70L.

[0063] Therefore, even when the first drive circuit 130 fails to function normally, the brake control device 100C can prevent the first parking brake device 70R from being unable to perform the locking operation and the release operation. That is, the brake control device 100C can apply a braking force to the right rear wheel 20R or release the application of the braking force to the right rear wheel 20R by the first parking brake device 70R.

[0064] Also, even when the second drive circuit 140 fails to function normally, the brake control device 100C can prevent the second parking brake device 70L from being unable to perform the locking operation and the release operation. That is, the brake control device 100C can apply a braking force to the left rear wheel 20L or release the application of the braking force to the left rear wheel 20L by the second parking brake device 70L.

[0065] <Modified Example> This embodiment can be implemented with the following modifications. This embodiment and the following modification examples can be implemented in combination with each other within a technically consistent range.

[0066] · The electric brake device 30 and the parking brake device 70 may be any brake devices that can apply a braking force to the wheel 20. For example, the parking brake device 70 may be a brake device configured to apply a braking force to the wheel 20 by pulling a wire.

[0067] · In the first embodiment, the second connection line 152 may be connected to the second-phase circuit 122 instead of the first-phase circuit 121, or may be connected to the third-phase circuit 123. Specifically, the second connection line 152 may be connected to the connection point of the upper switching element 126 and the lower switching element 127 in the second-phase circuit 122. Also, the second connection line 152 may be connected to the connection point of the upper switching element 128 and the lower switching element 129 in the third-phase circuit 123. The same applies to other embodiments.

[0068] · In the third embodiment, the third connection line 153 may be connected to the first-phase circuit 121 instead of the second-phase circuit 122, or may be connected to the third-phase circuit 123. Specifically, the second connection line 152 may be connected to the connection point of the upper switching element 124 and the lower switching element 125 in the first-phase circuit 121. Also, the second connection line 152 may be connected to the connection point of the upper switching element 128 and the lower switching element 129 in the third-phase circuit 123. The same applies to the fourth embodiment.

[0069] · The vehicle 10 may be an autonomous vehicle. In this case, the braking control device 100 may be requested by another control device to decelerate the vehicle 10. In this case, the braking control unit 170 may calculate the braking force corresponding to the deceleration of the vehicle 10 requested by another control device as the required braking force.

[0070] · As used herein, the expression "at least one" means "one or more" of the desired options. As an example, as used herein, the expression "at least one" means "only one option" or "both of the two options" if the number of options is two. As another example, as used herein, the expression "at least one" means "only one option" or "any combination of two or more options" if the number of options is three or more.

Explanation of Signs

[0071] 10… Vehicle 20… Wheel 30… Electric braking device 52… Brushless motor 70(70R)… Parking brake device (First parking brake device) 70(70L)… Parking brake device (Second parking brake device) 71(71R)… Brushed motor (First brushed motor) 71(71L)… Brushed motor (Second brushed motor) 90… DC power supply 100,100A~100C… Brake control device (Motor control device) 120… Inverter circuit 121… First-phase circuit 122… Second-phase circuit 123… Third-phase circuit 124~129… Switching elements 130… First drive circuit 131~134… Switching elements 140… Second drive circuit 141~144… Switching elements 150,150A~150C… Redundant circuit 151,152,153,154… First connection wire, Second connection wire, Third connection wire, Fourth connection wire 155,156… First ground connection wire, Second ground connection wire 161~164… First switching element, Second switching element, Third switching element, Fourth switching element GND…Ground

Claims

1. A motor control device that controls a brushless motor which is a power source of an electric brake device for applying a braking force to a wheel, and a brushed motor which is a power source of a parking brake device for applying a braking force to the wheel, an inverter circuit that drives the brushless motor, a drive circuit that drives the brushed motor, and a redundant circuit that drives the brushed motor via the inverter circuit, wherein the inverter circuit has a first-phase circuit, a second-phase circuit, and a third-phase circuit that are connected in parallel to each other and connected to a DC power supply, each of the first-phase circuit, the second-phase circuit, and the third-phase circuit includes an upper switching element and a lower switching element connected in series, the redundant circuit includes a first connection line that connects the DC power supply and one power supply terminal of the brushed motor, a second connection line that connects a connection point between the upper switching element and the lower switching element in one of the first-phase circuit, the second-phase circuit, and the third-phase circuit and the other power supply terminal of the brushed motor, and a first switching element provided on the first connection line. A motor control device.

2. The parking brake device is configured to perform a lock operation of applying a braking force to the wheel and a release operation of canceling the application of the braking force to the wheel according to the rotation direction of the output shaft of the brushed motor, the redundant circuit includes a first ground connection line that connects a portion between the first switching element and one power supply terminal of the brushed motor in the first connection line and ground, and a second switching element provided on the first ground connection line. The motor control device according to Claim 1.

3. A motor control device that controls a brushless motor which is a power source of an electric brake device for applying a braking force to a first wheel and a second wheel, a first brushed motor which is a power source of a first parking brake device for applying a braking force to the first wheel, and a second brushed motor which is a power source of a second parking brake device for applying a braking force to the second wheel, an inverter circuit that drives the brushless motor, a first drive circuit that drives the first brushed motor, a second drive circuit that drives the second brushed motor, and a redundant circuit that drives the first brushed motor and the second brushed motor via the inverter circuit. The inverter circuit has a first-phase circuit, a second-phase circuit, and a third-phase circuit that are connected in parallel to each other and connected to a DC power supply. Each of the first-phase circuit, the second-phase circuit, and the third-phase circuit includes an upper switching element and a lower switching element that are connected in series. The redundant circuit a first connection line connecting the DC power supply and one power supply terminal of the first brush motor; a second connection line connecting a connection point of the upper switching element and the lower switching element in one of the first-phase circuit, the second-phase circuit, and the third-phase circuit and the other power supply terminal of the first brush motor; a first switching element provided on the first connection line; a third connection line connecting the DC power supply and one power supply terminal of the second brush motor; a fourth connection line connecting a connection point of the upper switching element and the lower switching element in one of the first-phase circuit, the second-phase circuit, and the third-phase circuit and the other power supply terminal of the second brush motor; and a third switching element provided on the third connection line. A motor control device.

4. The first parking brake device is configured to perform a lock operation of applying a braking force to the first wheel and a release operation of canceling the application of the braking force to the first wheel according to the rotation direction of the output shaft of the first brush motor. The second parking brake device is configured to perform a lock operation of applying a braking force to the second wheel and a release operation of canceling the application of the braking force to the second wheel according to the rotation direction of the output shaft of the second brush motor. The redundant circuit a first ground connection line connecting a portion between the first switching element and one power supply terminal of the first brush motor in the first connection line and the ground; a second switching element provided on the first ground connection line; a second ground connection line connecting a portion between the third switching element and one power supply terminal of the second brush motor in the third connection line and the ground; and a fourth switching element provided on the second ground connection line. The motor control device according to claim 3.

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