Motor back electromotive force suppression circuit and electronic parking brake motor control device

Abstract

This application discloses a back electromotive force (EMF) suppression circuit for a motor and an electronic parking brake motor control device, applied in the field of electric vehicle technology. It addresses the problem in the prior art where the generation of back EMF reduces the reliability of the electronic parking brake motor control device. Specifically, it includes a first suppression branch and a second suppression branch respectively set for the first and second bridge arms of the full-bridge circuit. Each suppression branch includes a state sensing module, an on / off control module, and a back EMF absorption module. The state sensing module outputs a first-level or second-level logic control signal based on the upper and lower switch drive signals. The on / off control module connects or disconnects the corresponding terminal of the motor from the back EMF absorption module. The back EMF absorption module absorbs the back EMF of the motor, achieving precise timing control for back EMF suppression and effectively improving the reliability and safety of the electronic parking brake motor control device.

Description

Technical Field

[0001] This application relates to the field of electric vehicle technology, and in particular to a motor back electromotive force suppression circuit and an electronic parking brake motor control device. Background Technology

[0002] With the rapid development of automotive electronics technology, the Electronic Parking Brake (EPB) system has become an important part of modern vehicle safety features. The EPB system uses electronic control to achieve the vehicle's parking function, replacing the traditional mechanical handbrake and providing drivers with a more convenient and intelligent parking experience.

[0003] Currently, the control of the EPB motor is typically handled by the Electronic Stability Control (ESC) controller or the integrated brake control system controller. These controllers activate the EPB motor by receiving driver commands or automatic triggering conditions to achieve vehicle parking brake operation. During EPB motor operation, when the motor winding current is suddenly cut off (such as during H-bridge drive circuit commutation or emergency stop), the motor generates a significant back electromotive force due to its inductive characteristics. This back electromotive force may be much higher than the power supply voltage and is conducted along the drive circuit to the power devices and signal interface circuits of the controller in the electronic parking brake motor control device. This can lead to power MOSFET breakdown, gate drive chip damage, or overvoltage failure of the microcontroller unit (MCU) analog / digital input pins, thereby reducing the reliability of the entire electronic parking brake motor control device. Summary of the Invention

[0004] This application provides a motor back electromotive force suppression circuit and an electronic parking brake motor control device to solve the problem in the prior art where the generation of motor back electromotive force reduces the reliability of the electronic parking brake motor control device.

[0005] The technical solutions provided in this application are as follows: On one hand, embodiments of this application provide a reverse electromotive force suppression circuit for a motor, including: a first suppression branch and a second suppression branch; The first suppression branch corresponds to the first bridge arm of the full-bridge circuit of the drive motor, and the second suppression branch corresponds to the second bridge arm of the full-bridge circuit of the drive motor. Each suppression branch includes: a state sensing module, an on / off control module, and a back electromotive force absorption module; The first and second input terminals of the state sensing module are respectively connected to the upper and lower switch drive terminals of the corresponding bridge arm. The third input terminal of the state sensing module is connected to an external power supply. The output terminal of the state sensing module is connected to the control terminal of the on / off control module. The state sensing module is used to output a first-level logic control signal when both the upper and lower switch drive signals are invalid. When either the upper or lower switch drive signal is valid, it outputs a second-level logic control signal that is opposite to the first level. The on / off control module is connected between the corresponding terminal of the motor and the first terminal of the reverse electromotive force absorption module. The on / off control module is used to connect the corresponding terminal of the motor to the reverse electromotive force absorption module in response to a logic control signal of the first level; and to disconnect the corresponding terminal of the motor from the reverse electromotive force absorption module in response to a logic control signal of the second level. The second terminal of the reverse electromotive force absorption module is connected to ground; the reverse electromotive force absorption module is used to absorb the reverse electromotive force of the motor.

[0006] Optionally, the state-aware module includes: a logic operation unit and a level conversion unit; The first input terminal of the logic operation unit is connected to the upper switch drive terminal of the corresponding bridge arm, the second input terminal of the logic operation unit is connected to the lower switch drive terminal of the corresponding bridge arm, and the output terminal of the logic operation unit is connected to the first input terminal of the level conversion unit. The logic operation unit is used to perform logic operations on the received upper switch drive signal and lower switch drive signal, and output the corresponding logic level signal. The second input terminal of the level conversion unit is connected to the external first power supply, the third input terminal of the level conversion unit is connected to the external second power supply, and the output terminal of the level conversion unit is connected to the control terminal of the on / off control module. The level conversion unit is used to convert logic level signals into logic control signals that match the voltage of the external second power supply, based on the voltage of the external first power supply and the external second power supply.

[0007] Optionally, the logic operation unit includes: a first NOR gate; The first input terminal of the first NOR gate is connected to the upper switch driver terminal of the corresponding bridge arm, the second input terminal of the first NOR gate is connected to the lower switch driver terminal of the corresponding bridge arm, and the output terminal of the first NOR gate is connected to the first input terminal of the level conversion unit.

[0008] Optionally, the level conversion unit includes: a first resistor, a first transistor, and a second transistor; The first end of the first resistor is connected to an external first power supply, and the second end of the first resistor is connected to the collector of the first transistor and the base of the second transistor, respectively. The base of the first transistor is connected to the output terminal of the first NOR gate, and the emitter of the first transistor is connected to ground. The emitter of the second transistor is connected to an external second power supply, and the collector of the second transistor is connected to the control terminal of the on / off control module.

[0009] Optionally, the on / off control module includes: a first MOSFET; The gate of the first MOSFET is connected to the output terminal of the state sensing module, the source of the first MOSFET is connected to the first terminal of the reverse electromotive force absorption module, and the drain of the first MOSFET is connected to the corresponding terminal of the motor.

[0010] Optionally, the reverse electromotive force absorption module includes: a second resistor and a first capacitor; The first terminal of the first capacitor is connected to the on / off control module, and the second terminal of the first capacitor is connected to ground via the second resistor.

[0011] On the other hand, embodiments of this application provide an electronic parking brake motor control device, including: an electronic parking brake motor, a control module, a drive module, a full-bridge circuit, and the aforementioned motor back electromotive force suppression circuit; The control module is connected to the drive module and the motor back EMF suppression circuit respectively; the power supply terminal of the control module is connected to the vehicle battery. The output terminal of the drive module is connected to the drive terminal of the switching transistor of each bridge arm in the full-bridge circuit; the power supply terminal of the drive module is connected to the vehicle battery. The first input terminal of the full-bridge circuit is connected to the vehicle battery, the second input terminal of the full-bridge circuit is connected to ground, the first output terminal of the full-bridge circuit is connected to the first terminal of the electronic parking brake motor, and the second output terminal of the full-bridge circuit is connected to the second terminal of the electronic parking brake motor. The first and second suppression branches of the motor reverse electromotive force suppression circuit are respectively connected between the corresponding terminals of the electronic parking brake motor and the reference ground. The motor reverse electromotive force suppression circuit is respectively connected to the switching transistor drive terminals of each bridge arm in the full bridge circuit.

[0012] Optionally, the control module includes: a power management chip and a control chip; The power input terminal of the power management chip is connected to the vehicle battery, the power output terminal of the power management chip is connected to the power input terminal of the control chip, and the communication terminal of the power management chip is connected to the control chip. The output terminal of the control chip is connected to the input terminal of the drive module, and the communication terminal of the control chip is connected to the drive module.

[0013] Optionally, the electronic parking brake motor control device includes: a reverse connection protection module; The reverse connection protection module is connected in series between the vehicle battery and the first input terminal of the full-bridge circuit, and the control terminal of the reverse connection protection module is connected to the power management chip. The reverse connection protection module is used to connect or disconnect the vehicle battery from the full-bridge circuit in response to the control signal from the power management chip.

[0014] Optionally, the reverse connection protection module includes: a second MOSFET; The source of the second MOSFET is connected to the vehicle battery, the drain of the second MOSFET is connected to the first input terminal of the full-bridge circuit, and the gate of the second MOSFET is connected to the power management chip.

[0015] The beneficial effects of the embodiments of this application are as follows: In this embodiment, the motor back EMF suppression circuit sets up a first suppression branch and a second suppression branch corresponding to the first and second arms of the full-bridge circuit, respectively. A state sensing module monitors the signal states of the upper and lower switch drive terminals of the corresponding arms in real time. When both the upper and lower switch drive signals are invalid, a first-level logic control signal is output to control the on / off control module to connect the corresponding motor terminal to the back EMF absorption module. When either the upper or lower switch drive signal is valid, a second-level logic control signal is output to control the on / off control module to disconnect the corresponding motor terminal from the back EMF absorption module. Thus, during the period when both upper and lower switches of the full-bridge circuit are off, a back EMF absorption path is automatically connected to absorb the motor's back EMF. During the period when either switch is on, the absorption path is automatically disconnected to avoid affecting normal driving. This achieves precise timing control of back EMF suppression, effectively improving the reliability and safety of the electronic parking brake motor control device.

[0016] Other features and advantages of this application will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of the first circuit structure of the motor reverse electromotive force suppression circuit in the embodiments of this application; Figure 2 This is a schematic diagram of the second circuit structure of the motor back electromotive force suppression circuit in the embodiments of this application; Figure 3 This is a schematic diagram of the third circuit structure of the motor back electromotive force suppression circuit in the embodiments of this application; Figure 4 This is a schematic diagram of the first circuit structure of the electronic parking brake motor control device in the embodiments of this application; Figure 5 This is a schematic diagram of a second circuit structure for the electronic parking brake motor control device in an embodiment of this application; Figure 6 This is a schematic diagram of a third circuit structure for the electronic parking brake motor control device in the embodiments of this application.

[0018] Icons: 100 - Motor reverse EMF suppression circuit; 110 - First suppression branch; 120 - Second suppression branch; 130 - Status sensing module; 140 - On / off control module; 150 - Reverse EMF absorption module; 131 - Logic operation unit; 132 - Level conversion unit; VCC1 - External first power supply; VCC2 - External second power supply; NOR1 - First NOR gate; R1 - First resistor; P1 - First transistor; P2 - Second transistor; Q1 - First MOSFET; R2 - Second resistor; C1 - First capacitor; 200 - Electronic parking brake motor control device; M - Electronic parking brake motor; 210 - Control module; 220 - Drive module; 230 - Full bridge circuit; 211 - Power management chip; 212 - Control chip; 240 - Reverse connection protection module; Q2 - Second MOSFET. Detailed Implementation

[0019] To make the objectives, technical solutions, and beneficial effects of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] This application provides a reverse electromotive force suppression circuit 100 for a motor, see reference. Figure 1 As shown, the motor reverse electromotive force suppression circuit 100 includes at least: a first suppression branch 110 and a second suppression branch 120; The first suppression branch 110 is set to the first bridge arm of the full bridge circuit 230 of the drive motor, and the second suppression branch 120 is set to the second bridge arm of the full bridge circuit 230 of the drive motor. Each suppression branch includes: a state sensing module 130, an on / off control module 140, and a back electromotive force absorption module 150; The first and second input terminals of the state sensing module 130 are respectively connected to the upper and lower switch drive terminals of the corresponding bridge arm. The third input terminal of the state sensing module 130 is connected to an external power supply. The output terminal of the state sensing module 130 is connected to the control terminal of the on / off control module 140. The state sensing module 130 is used to output a logic control signal of the first level when both the upper and lower switch drive signals are invalid; and to output a logic control signal of the second level, which is opposite to the first level, when either the upper or lower switch drive signal is valid. The on / off control module 140 is connected between the corresponding end of the motor and the first end of the reverse electromotive force absorption module 150. The on / off control module 140 is used to connect the corresponding end of the motor to the reverse electromotive force absorption module 150 in response to a logic control signal of the first level; and to disconnect the corresponding end of the motor from the reverse electromotive force absorption module 150 in response to a logic control signal of the second level. The second end of the reverse electromotive force absorption module 150 is connected to ground; the reverse electromotive force absorption module 150 is used to absorb the reverse electromotive force of the motor.

[0021] exist Figure 1In the motor back electromotive force suppression circuit 100 shown, the first suppression branch 110 corresponds to the first bridge arm of the full-bridge circuit of the drive motor, and the second suppression branch 120 corresponds to the second bridge arm of the full-bridge circuit of the drive motor. Each suppression branch includes three functional units: a state sensing module 130, an on / off control module 140, and a back electromotive force absorption module 150. The three modules are electrically connected in sequence to form a protection path for the corresponding port of the motor. The first input terminal of the state sensing module 130 is electrically connected to the upper switch driving terminal of the corresponding bridge arm to receive the driving signal of the upper switch; the second input terminal of the state sensing module 130 is electrically connected to the lower switch driving terminal of the corresponding bridge arm to receive the driving signal of the lower switch; the third input terminal of the state sensing module 130 is electrically connected to an external power supply to obtain the electrical energy required for the module to operate; and the output terminal of the state sensing module 130 is electrically connected to the control terminal of the on / off control module 140 to output logic control commands. The state sensing module 130 integrates a logic operation circuit to monitor the validity status of the upper and lower switch drive signals in real time. When both signals are simultaneously in an invalid state, the state sensing module 130 outputs a first-level logic control signal, indicating that the back electromotive force (EMF) is allowed to be released to the back EMF absorption module 150 at a high or low level. When either signal is valid, the state sensing module 130 outputs a second-level logic control signal, which is logically opposite to the first level, indicating a normal operating state where the back EMF absorption module 150 is prohibited from intervening. The on / off control module 140 is connected in series between the corresponding end of the motor and the first end of the back EMF absorption module 150. The corresponding end of the motor refers to one of the two ends of the motor winding. The on / off control modules 140 on the two branches are connected to different ends of the motor winding. The control terminal of the on / off control module 140 receives the logic control signal from the state sensing module 130. The on / off control module 140 executes a switching action based on the received logic control signal level. When a first-level logic control signal is received, the switching device inside the on / off control module 140 is in the on state, thereby establishing a low-impedance electrical path between the corresponding terminal of the motor and the back EMF absorption module 150. When a second-level logic control signal is received, the switching device inside the on / off control module 140 is in the off state, thereby forming electrical isolation between the corresponding terminal of the motor and the back EMF absorption module 150, cutting off the electrical connection between the two. The back EMF absorption module 150 serves as an energy dissipation unit. The first terminal of the back EMF absorption module 150 is electrically connected to the on / off control module 140, and the second terminal of the back EMF absorption module 150 is electrically connected to the reference ground potential, forming an energy discharge circuit.When the on / off control module 140 is turned on in response to the first level logic control signal, the back electromotive force generated by the sudden change in current in the motor winding is transmitted to the back electromotive force absorption module 150 through the on / off control module 140. The back electromotive force absorption module 150 absorbs and converts the back electromotive force energy through resistor consumption and capacitor energy storage, thereby suppressing the overvoltage at the motor port. When the on / off control module 140 is turned off in response to the second level logic control signal, the electrical path between the back electromotive force absorption module 150 and the corresponding terminal of the motor is physically cut off. At this time, the normal PWM drive signal of the full-bridge circuit is not affected by the absorption module, ensuring the drive efficiency of the motor under normal operating conditions.

[0022] In practical applications, when both the upper and lower switches of the full-bridge circuit are in the off state, the state sensing module 130 detects that both drive terminals are at invalid levels. At this time, it outputs a first level to turn on the on / off control module 140, and the reverse electromotive force absorption module 150 is connected to the motor port to provide a release path for the energy stored in the motor windings, preventing the induced electromotive force generated at the moment of turn-off from damaging the switches. When the upper or lower switch of any bridge arm in the full-bridge circuit is in the on state, the state sensing module 130 detects a valid drive signal and outputs a second level to turn off the on / off control module 140, and the reverse electromotive force absorption module 150 is disconnected from the motor port, ensuring that the full-bridge circuit can normally drive and control the motor, and preventing the absorption module from causing a load effect on the normal drive signal.

[0023] In this way, the motor back EMF suppression circuit 100 sets up a first suppression branch 110 and a second suppression branch 120 corresponding to the first and second bridge arms of the full-bridge circuit, respectively. The state sensing module 130 monitors the signal status of the upper and lower switch drive terminals of the corresponding bridge arms in real time. When both the upper and lower switch drive signals are invalid, it outputs a first-level logic control signal to control the on / off control module 140 to connect the corresponding motor terminal to the back EMF absorption module 150. When either the upper or lower switch drive signal is valid, it outputs a second-level logic control signal to control the on / off control module 140 to disconnect the corresponding motor terminal from the back EMF absorption module 150. Thus, during the period when both the upper and lower switches of the full-bridge circuit are off, the back EMF absorption path is automatically connected to absorb the motor back EMF. During the period when either switch is on, the absorption path is automatically cut off to avoid affecting normal drive. This achieves precise timing control of back EMF suppression and effectively improves the reliability and safety of the motor drive system.

[0024] In one possible implementation, see [reference] Figure 2 As shown, the state-aware module 130 includes: a logic operation unit 131 and a level conversion unit 132; The first input terminal of the logic operation unit 131 is connected to the upper switch drive terminal of the corresponding bridge arm, the second input terminal of the logic operation unit 131 is connected to the lower switch drive terminal of the corresponding bridge arm, and the output terminal of the logic operation unit 131 is connected to the first input terminal of the level conversion unit 132. The logic operation unit 131 is used to perform logic operations on the received upper switch drive signal and lower switch drive signal, and output the corresponding logic level signal. The second input terminal of the level conversion unit 132 is connected to the external first power supply VCC1, the third input terminal of the level conversion unit 132 is connected to the external second power supply VCC2, and the output terminal of the level conversion unit 132 is connected to the control terminal of the on / off control module 140. The level conversion unit 132 is used to convert the logic level signal into a first level or a second level logic control signal that matches the voltage of the external second power supply VCC2 based on the voltage of the external first power supply VCC1 and the external second power supply VCC2.

[0025] exist Figure 2 In the motor reverse electromotive force suppression circuit 100 shown, the first input terminal of the logic operation unit 131 is electrically connected to the driving terminal of the upper switch transistor of the corresponding bridge arm, and is used to receive the driving control signal of the upper switch transistor; the second input terminal of the logic operation unit 131 is electrically connected to the driving terminal of the lower switch transistor of the corresponding bridge arm, and is used to receive the driving control signal of the lower switch transistor; the output terminal of the logic operation unit 131 is electrically connected to the first input terminal of the level conversion unit 132, and is used to transmit the intermediate signal after logical operation, i.e., the logic level signal. The logic operation unit 131 integrates logic gate circuits internally, which are used to perform logical operation processing on the driving signals of the upper and lower switches transistors. When both the upper and lower switch drive signals are detected to be in an invalid state, the logic operation unit 131 outputs a first logic level signal indicating that the reverse electromotive force absorption module 150 is allowed to connect. When either the upper or lower switch drive signal is detected to be in an active state, the logic operation unit 131 outputs a second logic level signal indicating that the reverse electromotive force absorption module 150 is prohibited from connecting. The first and second logic level signals are inverse logic states. Through the configuration of the logic operation unit 131, real-time monitoring and logic synthesis of the conduction state of the upper and lower switches in the full-bridge circuit are realized, and the subsequent absorption action is triggered only when both switches are turned off simultaneously, avoiding accidental triggering of the reverse electromotive force absorption function during the conduction of either switch.

[0026] The first input terminal of the level conversion unit 132 is electrically connected to the output terminal of the logic operation unit 131, and is used to receive the logic level signal output by the logic operation unit 131. The second input terminal of the level conversion unit 132 is electrically connected to the external first power supply VCC1, and is used to introduce the power supply voltage of the circuit area where the logic operation unit 131 is located as a reference level. The third input terminal of the level conversion unit 132 is electrically connected to the external second power supply VCC2, and is used to introduce the power supply voltage of the circuit area where the on / off control module 140 is located as the target conversion level. The output terminal of the level conversion unit 132 is electrically connected to the control terminal of the on / off control module 140, and is used to output the logic control signal after voltage adaptation. The level conversion unit 132 is used to realize signal transmission and level matching between different voltage domains. Based on the voltage amplitude provided by the external first power supply VCC1 and the voltage amplitude provided by the external second power supply VCC2, the level conversion unit 132 converts the voltage amplitude of the logic level signal output by the logic operation unit 131 to generate a first level or second level logic control signal that matches the voltage of the external second power supply VCC2. This level conversion function ensures that the voltage amplitude of the control signal is consistent with the drive voltage requirements of the on / off control module 140.

[0027] Specifically, the external first power supply VCC1 provides the operating voltage for the logic operation unit 131 and its preceding control circuit. This power supply voltage is typically a low-voltage logic level used in digital control circuits, such as a 3.3V or 5V DC voltage. The external second power supply VCC2 provides the operating voltage for the on / off control module 140 and its drive circuit. This power supply voltage is typically a higher level required for driving power switching devices, such as a 12V, 15V, or higher amplitude DC voltage. Since the logic operation unit 131 and the on / off control module 140 may operate in different voltage domains, directly transmitting the output signal of the logic operation unit 131 to the on / off control module 140 may cause the on / off control module 140 to fail to conduct or turn off properly due to voltage amplitude mismatch, or even damage the devices. The level conversion unit 132 enables signal conversion from the voltage domain of the external first power supply VCC1 to the voltage domain of the external second power supply VCC2, ensuring that the level of the signal output by the level conversion unit 132 can reliably drive the switching devices inside the on / off control module 140 into the conducting state or reliably into the off state.

[0028] In this way, by dividing the state sensing module 130 into a logic operation unit 131 and a level conversion unit 132, modular separation of control logic functions and interface driving functions is achieved. The logic operation unit 131 focuses on the logical synthesis and judgment of the switching transistor drive signals, and can be implemented using low-voltage digital integrated circuits, featuring low power consumption and fast response. The level conversion unit 132 focuses on signal adaptation between different voltage domains, featuring strong anti-interference ability and strong driving capability. The division of labor and cooperation between the two units ensures the accuracy of logic judgment and meets the electrical characteristic requirements of the power drive interface, improving the applicability and reliability of the motor back electromotive force suppression circuit 100, enabling it to adapt to full-bridge drive circuits and power switching devices of different voltage levels.

[0029] In one possible implementation, see [reference] Figure 3 As shown, the logic operation unit 131 includes: a first NOR gate NOR1; The first input terminal of the first NOR gate NOR1 is connected to the upper switch driver terminal of the corresponding bridge arm, the second input terminal of the first NOR gate NOR1 is connected to the lower switch driver terminal of the corresponding bridge arm, and the output terminal of the first NOR gate NOR1 is connected to the first input terminal of the level conversion unit 132.

[0030] exist Figure 3 In the motor reverse electromotive force suppression circuit 100 shown, the first input terminal of the first NOR gate NOR1 is electrically connected to the driving terminal of the upper switch transistor of the corresponding bridge arm, and is used to receive the driving control signal of the upper switch transistor in real time; the second input terminal of the first NOR gate NOR1 is electrically connected to the driving terminal of the lower switch transistor of the corresponding bridge arm, and is used to receive the driving control signal of the lower switch transistor in real time; the output terminal of the first NOR gate NOR1 is electrically connected to the first input terminal of the level conversion unit 132, and is used to transmit the result of the NOR logic operation to the subsequent level conversion unit 132 for signal level conversion. The first NOR gate NOR1 integrates an NOR logic operation circuit. When the logic level states received by the first input terminal and the second input terminal are both low-level invalid levels, the output terminal of the first NOR gate NOR1 outputs a high-level logic signal; when either the first input terminal or the second input terminal receives a high-level valid level, or when both terminals simultaneously receive a high-level valid level, the output terminal of the first NOR gate NOR1 outputs a low-level logic signal.

[0031] In the actual operation of a full-bridge drive circuit, the drive signals for the upper and lower switches on the same bridge arm typically employ a complementary conduction control strategy, with a dead-time protection period. A high-level state of the drive signal is defined as the active level, used to drive the corresponding switch to conduct; a low-level state is defined as the inactive level, used to control the corresponding switch to turn off. Under normal driving conditions, the upper and lower switches conduct alternately, and the two inputs of the first NOR gate (NOR1) receive inverse drive signals, i.e., one end is a high active level and the other is a low inactive level. At this time, the output of the first NOR gate (NOR1) outputs a low-level logic signal. During the dead-time protection period, both the upper and lower switches are simultaneously off, and both inputs of the first NOR gate (NOR1) simultaneously receive a low inactive signal. At this time, the output of the first NOR gate (NOR1) outputs a high-level logic signal. Under normal full-bridge circuit operation, the upper and lower switches will not simultaneously receive high active signals, therefore, the first NOR gate (NOR1) will not have both inputs at a high level. The logic operation of the first NOR gate (NOR1) enables real-time hardware monitoring of the simultaneous off-state of the upper and lower switches in the full-bridge circuit. When the first NOR gate (NOR1) outputs a high-level logic signal, it indicates that both the upper and lower switches are off. At this time, the motor winding current is forced to stop, generating a back electromotive force (EMF). This high-level logic signal is transmitted as a trigger signal to the level conversion unit 132. After level conversion, it generates a first-level logic control signal, which drives the on / off control module 140 to connect the back EMF absorption module 150, providing a low-impedance path for the back EMF. When the first NOR gate (NOR1) outputs a low-level logic signal, it indicates that at least one of the upper or lower switches is on, and the motor is in a normal driving or freewheeling state. This low-level logic signal is generated as a second-level logic control signal after level conversion, which drives the on / off control module 140 to turn off, cutting off the connection between the motor port and the back EMF absorption module 150, ensuring that the back EMF absorption module 150 does not affect the normal PWM driving function of the full-bridge circuit.

[0032] In one possible implementation, see [reference] Figure 3 As shown, the level conversion unit 132 includes: a first resistor R1, a first transistor P1, and a second transistor P2; The first end of the first resistor R1 is connected to the external first power supply VCC1, and the second end of the first resistor R1 is connected to the collector of the first transistor P1 and the base of the second transistor P2. The base of the first transistor P1 is connected to the output terminal of the first NOR gate NOR1, and the emitter of the first transistor P1 is connected to ground. The emitter of the second transistor P2 is connected to the external second power supply VCC2, and the collector of the second transistor P2 is connected to the control terminal of the on / off control module 140.

[0033] exist Figure 3 In the motor reverse electromotive force suppression circuit 100 shown, the first resistor R1 is used as both a pull-up resistor and a bias resistor. Its first terminal is electrically connected to the external first power supply VCC1 to introduce the power supply voltage of the circuit region where the logic operation unit 131 is located. The second terminal of the first resistor R1 is electrically connected to the collector of the first transistor P1 and the base of the second transistor P2, forming a signal coupling node between the first-stage switching circuit and the second-stage switching circuit. When the first transistor P1 is in the off state, the first resistor R1 pulls the node voltage up to the external first power supply VCC1 voltage, providing a base bias voltage for the second transistor P2. The first transistor P1, as the first-stage inverting switch, adopts an NPN bipolar transistor structure. When the output terminal of the first NOR gate NOR1 outputs a high-level logic signal, a forward bias voltage is formed between the base and emitter of the first transistor P1, and the first transistor P1 enters the saturation conduction state, pulling the collector potential down to near ground potential. When the output terminal of the first NOR gate NOR1 outputs a low-level logic signal, the bias voltage between the base and emitter of the first transistor P1 is zero or reverse biased, and the first transistor P1 enters the cutoff state, and the collector potential is pulled up to the external first power supply VCC1 voltage by the first resistor R1. The second transistor P2, acting as a second-stage in-phase switch and level shifter, employs a PNP bipolar transistor structure. When the first transistor P1 is in saturation conduction, its collector potential is close to ground, and its base potential is lower than its emitter potential, causing P2 to enter saturation conduction and output a first-level logic control signal. When the first transistor P1 is in cutoff state, the first resistor R1 pulls the base potential of P2 up to the external first power supply VCC1, causing P2 to enter cutoff state and output a second-level logic control signal.

[0034] In practical applications, when the upper and lower switching transistors of the full-bridge circuit are turned off simultaneously, the first NOR gate NOR1 outputs a high-level logic signal. This high level acts on the base of the first transistor P1, causing the first transistor P1 to saturate and conduct. The collector potential of the first transistor P1 is pulled low, which in turn causes the second transistor P2 to saturate and conduct. The collector of the second transistor P2 outputs a high-level logic control signal close to the voltage of the external second power supply VCC2 to the on / off control module 140, driving the on / off control module 140 to connect the reverse electromotive force absorption module 150. When either the upper or lower switch of the full-bridge circuit is turned on, the first NOR gate NOR1 outputs a low-level logic signal, the first transistor P1 is turned off, the first resistor R1 pulls the base potential of the second transistor P2 up to the external first power supply VCC1 voltage, the second transistor P2 is turned off, there is no drive current output at the collector of the second transistor P2, the control terminal of the on / off control module 140 is in a low-level state, driving the on / off control module 140 to turn off to cut off the reverse electromotive force absorption module 150.

[0035] In one possible implementation, see [reference] Figure 3 As shown, the on / off control module 140 includes: a first MOSFET Q1; The gate of the first MOSFET Q1 is connected to the output terminal of the state sensing module 130, the source of the first MOSFET Q1 is connected to the first terminal of the reverse electromotive force absorption module 150, and the drain of the first MOSFET Q1 is connected to the corresponding terminal of the motor.

[0036] exist Figure 3 In the motor reverse electromotive force suppression circuit 100 shown, the first MOSFET Q1 is connected in series as a controllable switching element between the corresponding terminal of the electronic parking brake motor M and the reverse electromotive force absorption module 150. Its on / off state is determined by the level of the logic control signal output by the state sensing module 130. When the state sensing module 130 detects that both the upper and lower switch drive signals of the corresponding bridge arm are invalid, it outputs a first-level logic control signal to the gate of the first MOSFET Q1, turning on the first MOSFET Q1, thereby establishing an electrical connection between the corresponding terminal of the motor and the reverse electromotive force absorption module 150, so that the reverse electromotive force generated by the motor windings can be discharged and absorbed through the reverse electromotive force absorption module 150. When the state sensing module 130 detects that either the upper switch drive signal or the lower switch drive signal is at an effective level, it outputs a second-level logic control signal to the gate of the first MOS transistor Q1, causing the first MOS transistor Q1 to turn off. This cuts off the electrical connection between the corresponding terminal of the electronic parking brake motor M and the reverse electromotive force absorption module 150, preventing the reverse electromotive force absorption module 150 from affecting the normal driving function of the electronic parking brake motor M.

[0037] In one possible implementation, see [reference] Figure 3 As shown, the reverse electromotive force absorption module 150 includes: a second resistor R2 and a first capacitor C1; The first terminal of the first capacitor C1 is connected to the on / off control module 140, and the second terminal of the first capacitor C1 is connected to ground via the second resistor R2.

[0038] exist Figure 3 In the motor reverse electromotive force suppression circuit 100 shown, the first capacitor C1 and the second resistor R2 are connected in series and then connected in parallel between the corresponding terminal of the electronic parking brake motor M and the reference ground. The first capacitor C1 is used as an energy storage element to absorb the reverse electromotive force energy generated by the motor winding during the current change process. The second resistor R2 is used as an energy dissipation element to dissipate the energy absorbed by the first capacitor C1 in the form of heat energy, thereby effectively suppressing the amplitude of the reverse electromotive force peak voltage. When the first MOSFET Q1 in the on / off control module 140 is turned on in response to a logic control signal of the first level, the back electromotive force generated at the corresponding terminal of the electronic parking brake motor M is applied to the series branch composed of the first capacitor C1 and the second resistor R2 through the turned-on first MOSFET Q1. At this time, the first capacitor C1 charges rapidly to absorb voltage spikes, and then slowly discharges through the second resistor R2, converting the stored electrical energy into heat energy for release. This prevents high-amplitude back electromotive force spikes from being directly applied to the power switching devices in the full-bridge circuit, thereby protecting the power switching devices from voltage breakdown damage. When the first MOSFET Q1 is turned off, the RC snubber circuit is disconnected from the corresponding terminal of the electronic parking brake motor M, without affecting the normal operation of the motor. By adjusting the capacitance of the first capacitor C1 and the resistance of the second resistor R2, the response time and absorption capacity of the back electromotive force absorption module 150 can be adjusted to meet the back electromotive force suppression requirements of electronic parking brake motors M of different specifications.

[0039] Based on the same concept, this application also provides an electronic parking brake motor control device, see reference. Figure 4 As shown, the electronic parking brake motor control device 200 includes: an electronic parking brake motor M, a control module 210, a drive module 220, a full-bridge circuit 230, and the aforementioned motor back electromotive force suppression circuit 100. The control module 210 is connected to the drive module 220 and the motor back electromotive force suppression circuit 100 respectively; the power supply terminal of the control module 210 is connected to the vehicle battery. The output terminal of the drive module 220 is connected to the drive terminal of the switching transistor of each bridge arm in the full-bridge circuit 230; the power supply terminal of the drive module 220 is connected to the vehicle battery. The first input terminal of the full-bridge circuit 230 is connected to the vehicle battery, the second input terminal of the full-bridge circuit 230 is connected to ground, the first output terminal of the full-bridge circuit 230 is connected to the first terminal of the electronic parking brake motor M, and the second output terminal of the full-bridge circuit 230 is connected to the second terminal of the electronic parking brake motor M. The first suppression branch 110 and the second suppression branch 120 of the motor reverse electromotive force suppression circuit 100 are respectively connected between the corresponding terminals of the electronic parking brake motor M and the reference ground. The motor reverse electromotive force suppression circuit 100 is respectively connected to the switching transistor drive terminals of each bridge arm in the full bridge circuit 230.

[0040] exist Figure 4In the electronic parking brake motor control device 200 shown, the control module 210 serves as a logic control and command generation unit. The signal output terminal of the control module 210 is electrically connected to the signal input terminal of the drive module 220 and the signal input terminal of the motor back EMF suppression circuit 100, respectively. It transmits motor steering and speed control commands to the drive module 220 and provides reference signals required for logic judgment to the motor back EMF suppression circuit 100. The power supply terminal of the control module 210 is electrically connected to the vehicle battery, which provides the DC power required for its operation. The drive module 220 serves as a signal isolation and power amplification unit. Its output terminal is electrically connected to the upper and lower switch drive terminals of the first and second bridge arms of the full-bridge circuit 230, respectively. It receives the low-voltage logic control signals output by the control module 210 and converts them into switch drive signals with sufficient driving capability. The power supply terminal of the drive module 220 is electrically connected to the vehicle battery to obtain the electrical energy required to drive the switch transistors. The first input terminal of the full-bridge circuit 230 is electrically connected to the positive terminal of the vehicle battery to introduce the positive terminal of the DC power supply; the second input terminal of the full-bridge circuit 230 is electrically connected to the reference ground potential to introduce the negative terminal of the DC power supply, thereby establishing a DC bus voltage between the two input terminals; the first output terminal of the full-bridge circuit 230 is electrically connected to the first terminal of the electronic parking brake motor M, and the second output terminal of the full-bridge circuit 230 is electrically connected to the second terminal of the electronic parking brake motor M. Through the orderly switching combination of the internal power switching transistors, the DC bus voltage is converted into an AC drive voltage and applied to the electronic parking brake motor M to realize the forward rotation, reverse rotation or braking control of the motor. The first suppression branch 110 of the motor reverse electromotive force suppression circuit 100 is electrically connected between the first terminal of the electronic parking brake motor M and the reference ground potential, and the second suppression branch 120 of the motor reverse electromotive force suppression circuit 100 is electrically connected between the second terminal of the electronic parking brake motor M and the reference ground potential. At the same time, the input terminal of the state sensing module 130 of the motor reverse electromotive force suppression circuit 100 is electrically connected to the upper switch driving terminal and the lower switch driving terminal of the corresponding bridge arm in the full bridge circuit 230, respectively, for real-time monitoring of the driving signal status of each bridge arm switch. When it is detected that both the upper and lower switching transistors of the same bridge arm in the full-bridge circuit 230 are in the off state, the on / off control module 140 in the motor reverse electromotive force suppression circuit 100 is turned on, connecting the reverse electromotive force absorption module 150 between the corresponding terminal of the motor and ground to absorb the stored energy released by the motor windings; when it is detected that any switching transistor is in the on state, the on / off control module 140 is turned off, cutting off the connection between the reverse electromotive force absorption module 150 and the motor, ensuring that the normal driving function of the full-bridge circuit 230 is not affected.

[0041] In one possible implementation, see [reference] Figure 5As shown, the control module 210 includes a power management chip 211 and a control chip 212; The power input terminal of the power management chip 211 is connected to the vehicle battery, the power output terminal of the power management chip 211 is connected to the power input terminal of the control chip 212, and the communication terminal of the power management chip 211 is connected to the control chip 212. The output terminal of the control chip 212 is connected to the input terminal of the drive module 220, and the communication terminal of the control chip 212 is connected to the drive module 220.

[0042] exist Figure 5 In the electronic parking brake motor control device 200 shown, the power input terminal of the power management chip 211 is electrically connected to the vehicle battery, directly obtaining raw DC power from the vehicle's electrical system. This power is typically a 12V or 24V vehicle DC voltage. The power output terminal of the power management chip 211 is electrically connected to the power input terminal of the control chip 212, providing the control chip 212 with operating power after voltage conversion and regulation. This output voltage is typically a 3.3V or 5V DC voltage required by the core and interface circuit of the control chip 212. The communication terminal of the power management chip 211 is electrically connected to the corresponding communication port of the control chip 212, used to transmit power status information, fault diagnosis data, or enable control signals, realizing bidirectional data interaction between the power management chip 211 and the control chip 212, enabling the control chip 212 to monitor the power operating status and perform protective actions in abnormal situations. The power input terminal of the control chip 212 is electrically connected to the power output terminal of the power management chip 211, receiving a DC operating voltage that has been regulated and filtered to provide stable power to the internal microprocessor core, memory, and peripheral interfaces of the chip. The output terminal of the control chip 212 is electrically connected to the input terminal of the drive module 220, and is used to output a pulse width modulation signal. This signal represents the target direction and torque of the electronic parking brake motor M. After being transmitted to the drive module 220, it is amplified to drive the power switching transistor in the full-bridge circuit 230. The communication terminal of the control chip 212 is electrically connected to the corresponding communication port of the drive module 220, and is used to establish a data communication link between the control chip 212 and the drive module 220. This enables the drive module 220 to provide status feedback, fault diagnosis information feedback, or drive parameter configuration functions, ensuring that the control chip 212 can monitor the working status of the drive module 220 in real time and cut off the drive signal in time when a fault occurs.

[0043] In practical applications, through the electrical connection between the power management chip 211 and the control chip 212, the high-voltage DC power supplied by the vehicle battery is first processed by the power management chip 211 through electromagnetic interference filtering, voltage reduction conversion, and output voltage regulation. This converts the power into a low-voltage DC power supply suitable for the operation of the digital control circuit before supplying it to the control chip 212, preventing interference from vehicle battery voltage fluctuations and electrical noise on the normal operation of the control chip 212. Simultaneously, the power management chip 211 reports power readiness status, undervoltage, or overvoltage fault information to the control chip 212 via a communication terminal. Based on this information, the control chip 212 determines whether to allow the drive module 220 to start or execute a fault protection shutdown. Through the electrical connection between the control chip 212 and the drive module 220, the low-voltage logic control signal generated by the control chip 212 is transmitted to the drive module 220 for electrical isolation and current amplification. The drive module 220 then drives the metal-oxide-semiconductor field-effect transistors or insulated-gate bipolar transistors in the full-bridge circuit 230 to perform switching operations based on this control signal. Meanwhile, the control chip 212 receives overcurrent, overtemperature or short-circuit fault signals fed back by the drive module 220 in real time through the communication terminal, realizing closed-loop monitoring and fault protection functions.

[0044] In one possible implementation, see [reference] Figure 6 As shown, the electronic parking brake motor control device 200 also includes: a reverse connection protection module 240; The reverse connection protection module 240 is connected in series between the vehicle battery and the first input terminal of the full bridge circuit 230, and the control terminal of the reverse connection protection module 240 is connected to the power management chip 211. The reverse connection protection module 240 is used to connect or disconnect the vehicle battery from the full bridge circuit 230 in response to the control signal of the power management chip 211.

[0045] exist Figure 6In the electronic parking brake motor control device 200 shown, the reverse connection protection module 240 serves as the power polarity protection and on / off control module 140. The power input terminal of the reverse connection protection module 240 is electrically connected to the positive or negative terminal of the vehicle battery, the power output terminal of the reverse connection protection module 240 is electrically connected to the first input terminal of the full bridge circuit 230, and the control terminal of the reverse connection protection module 240 is electrically connected to the control signal output terminal of the power management chip 211. The reverse connection protection module 240 is used to perform on or off actions in response to the control signal output by the power management chip 211: When the power management chip 211 detects that the vehicle battery connection polarity is correct and the voltage is within the normal operating range, it outputs a control signal to the reverse connection protection module 240 to allow conduction. The switching device inside the reverse connection protection module 240 enters the conducting state, and a low-impedance electrical path is formed between the vehicle battery and the full-bridge circuit 230, allowing DC power to be transmitted normally to the full-bridge circuit 230. When the power management chip 211 detects that the vehicle battery connection polarity is incorrect, the voltage is abnormal, or the system needs emergency power-off protection, it outputs a cut-off control signal to the reverse connection protection module 240. The switching device inside the reverse connection protection module 240 enters the off state, and the electrical connection between the vehicle battery and the full-bridge circuit 230 is physically cut off, preventing reverse current from flowing into the full-bridge circuit 230 and subsequent circuits, which could cause the power switching device to break down or the control circuit to malfunction.

[0046] In one possible implementation, see [reference] Figure 6 As shown, the reverse connection protection module 240 includes: a second MOSFET Q2; The source of the second MOSFET Q2 is connected to the vehicle battery, the drain of the second MOSFET Q2 is connected to the first input terminal of the full-bridge circuit 230, and the gate of the second MOSFET Q2 is connected to the power management chip 211.

[0047] exist Figure 6In the electronic parking brake motor control device 200 shown, a control voltage is applied to the gate of the second MOSFET Q2 to actively connect and disconnect the electrical path between the vehicle battery and the full-bridge circuit 230. Simultaneously, the unidirectional conductivity of the internal parasitic diode of the second MOSFET Q2 is utilized to achieve hardware-level reverse connection protection. The second MOSFET Q2 adopts a P-channel structure, and its source is connected to the high-potential terminal of the vehicle battery under normal operating conditions. When the power management chip 211 completes the system power-on self-test and confirms that the battery voltage polarity is correct and the amplitude is within the normal operating range, it outputs a control voltage lower than the source potential to the gate of the second MOSFET Q2. The second MOSFET Q2 enters a low-resistance conduction state, and the DC power output from the vehicle battery is transmitted to the first input terminal of the full-bridge circuit 230, providing operating power to the electronic parking brake motor control device 200. When the vehicle battery is reverse-connected, the body diode integrated inside the second MOSFET Q2 is in a reverse bias state, and the second MOSFET Q2 remains in a high-resistance off state, effectively preventing reverse current from flowing into the full-bridge circuit 230 and causing damage to the power switching devices or malfunction of the control circuit logic.

[0048] It should be noted that although several units or sub-units of the device have been mentioned in the detailed description above, this division is merely exemplary and not mandatory. In fact, according to embodiments of this application, the features and functions of two or more units described above can be embodied in one unit. Conversely, the features and functions of one unit described above can be further divided and embodied by multiple units.

[0049] Furthermore, although the operations of the method of this application are described in a specific order in the accompanying drawings, this does not require or imply that these operations must be performed in that specific order, or that all the operations shown must be performed to achieve the desired result. Additionally or alternatively, certain steps may be omitted, multiple steps may be combined into one step, and / or one step may be broken down into multiple steps.

[0050] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0051] Obviously, those skilled in the art can make various modifications and variations to the embodiments of this application without departing from the spirit and scope of the embodiments of this application. Therefore, if these modifications and variations to the embodiments of this application fall within the scope of the claims of this application and their equivalents, this application also intends to include these modifications and variations.

Claims

1. A reverse electromotive force suppression circuit for a motor, characterized in that, include: First suppression branch and second suppression branch; The first suppression branch is configured to correspond to the first bridge arm of the full-bridge circuit of the drive motor, and the second suppression branch is configured to correspond to the second bridge arm of the full-bridge circuit of the drive motor. Each suppression branch includes: a state sensing module, an on / off control module, and a back electromotive force absorption module; The first and second input terminals of the state sensing module are respectively connected to the upper and lower switch driving terminals of the corresponding bridge arm. The third input terminal of the state sensing module is connected to an external power supply. The output terminal of the state sensing module is connected to the control terminal of the on / off control module. The state sensing module is used to output a first-level logic control signal when both the upper and lower switch driving signals are invalid. When either the upper or lower switch driving signal is valid, it outputs a second-level logic control signal that is opposite to the first level. The on / off control module is connected between the corresponding end of the motor and the first end of the reverse electromotive force absorption module; the on / off control module is used to connect the corresponding end of the motor to the reverse electromotive force absorption module in response to the first level logic control signal; and to disconnect the corresponding end of the motor from the reverse electromotive force absorption module in response to the second level logic control signal. The second end of the reverse electromotive force absorption module is connected to ground; the reverse electromotive force absorption module is used to absorb the reverse electromotive force of the motor.

2. The motor back electromotive force suppression circuit according to claim 1, characterized in that, The state sensing module includes: a logic operation unit and a level conversion unit; The first input terminal of the logic operation unit is connected to the upper switch drive terminal of the corresponding bridge arm, the second input terminal of the logic operation unit is connected to the lower switch drive terminal of the corresponding bridge arm, and the output terminal of the logic operation unit is connected to the first input terminal of the level conversion unit; the logic operation unit is used to perform logic operations on the received upper switch drive signal and lower switch drive signal, and output the corresponding logic level signal. The second input terminal of the level conversion unit is connected to an external first power supply, the third input terminal of the level conversion unit is connected to an external second power supply, and the output terminal of the level conversion unit is connected to the control terminal of the on / off control module. The level conversion unit is used to convert the logic level signal into a logic control signal of the first level or the second level that matches the voltage of the external second power supply, based on the voltage of the external first power supply and the external second power supply.

3. The motor back electromotive force suppression circuit according to claim 2, characterized in that, The logic operation unit includes: a first NOR gate; The first input terminal of the first NOR gate is connected to the upper switch driving terminal of the corresponding bridge arm, the second input terminal of the first NOR gate is connected to the lower switch driving terminal of the corresponding bridge arm, and the output terminal of the first NOR gate is connected to the first input terminal of the level conversion unit.

4. The motor back electromotive force suppression circuit according to claim 3, characterized in that, The level conversion unit includes: a first resistor, a first transistor, and a second transistor; The first end of the first resistor is connected to an external first power supply, and the second end of the first resistor is connected to the collector of the first transistor and the base of the second transistor, respectively. The base of the first transistor is connected to the output terminal of the first NOR gate, and the emitter of the first transistor is connected to ground. The emitter of the second transistor is connected to an external second power supply, and the collector of the second transistor is connected to the control terminal of the on / off control module.

5. The motor back electromotive force suppression circuit according to claim 1, characterized in that, The on / off control module includes: a first MOSFET; The gate of the first MOS transistor is connected to the output terminal of the state sensing module, the source of the first MOS transistor is connected to the first terminal of the reverse electromotive force absorption module, and the drain of the first MOS transistor is connected to the corresponding terminal of the motor.

6. The motor back electromotive force suppression circuit according to claim 1, characterized in that, The reverse electromotive force absorption module includes: a second resistor and a first capacitor; The first terminal of the first capacitor is connected to the on / off control module, and the second terminal of the first capacitor is connected to ground via the second resistor.

7. An electronic parking brake motor control device, characterized in that, include: Electronic parking brake motor, control module, drive module, full-bridge circuit, and motor back electromotive force suppression circuit as described in any one of claims 1-6; The control module is connected to the drive module and the motor back electromotive force suppression circuit respectively; the power supply terminal of the control module is connected to the vehicle battery. The output terminal of the drive module is connected to the drive terminal of the switching transistor of each bridge arm in the full-bridge circuit; the power supply terminal of the drive module is connected to the vehicle battery. The first input terminal of the full-bridge circuit is connected to the vehicle battery, the second input terminal of the full-bridge circuit is connected to ground, the first output terminal of the full-bridge circuit is connected to the first terminal of the electronic parking brake motor, and the second output terminal of the full-bridge circuit is connected to the second terminal of the electronic parking brake motor. The first and second suppression branches of the motor back electromotive force suppression circuit are respectively connected between the corresponding terminals of the electronic parking brake motor and the reference ground. The motor back electromotive force suppression circuit is respectively connected to the switching transistor drive terminals of each bridge arm in the full bridge circuit.

8. The electronic parking brake motor control device according to claim 7, characterized in that, The control module includes: a power management chip and a control chip; The power input terminal of the power management chip is connected to the vehicle battery, the power output terminal of the power management chip is connected to the power input terminal of the control chip, and the communication terminal of the power management chip is connected to the control chip. The output terminal of the control chip is connected to the input terminal of the drive module, and the communication terminal of the control chip is connected to the drive module.

9. The electronic parking brake motor control device according to claim 8, characterized in that, Also includes: Reverse connection protection module; The reverse connection protection module is connected in series between the vehicle battery and the first input terminal of the full bridge circuit, and the control terminal of the reverse connection protection module is connected to the power management chip. The reverse connection protection module is used to connect or disconnect the vehicle battery from the full-bridge circuit in response to the control signal of the power management chip.

10. The electronic parking brake motor control device according to claim 9, characterized in that, The reverse connection protection module includes: a second MOSFET; The source of the second MOSFET is connected to the vehicle battery, the drain of the second MOSFET is connected to the first input terminal of the full-bridge circuit, and the gate of the second MOSFET is connected to the power management chip.

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