Circuit for switching driving signals of double-control EPBH bridge

Abstract

The utility model discloses a circuit for switching driving signals of a double-control EPBH bridge. Each of the main control part and the backup part comprises a power management module, an MCU2 micro-control unit, a driving signal switching module and a driving voltage switching module which are connected in sequence, the driving signal switching module is connected to a parking H-bridge pre-driving chip, the parking H-bridge pre-driving chip is connected with a parking driving H-bridge circuit, and the driving voltage switching module is connected with a parking driving H-bridge circuit. And the driving signal switching module performs channel control on the driving signals PWM1 and PWM2 to ensure that only one of the driving signals is transmitted to the parking H-bridge pre-driving chip at the same moment so as to control the parking driving H-bridge circuit. According to the utility model, through the driving signal switching module, signals of the same parking H-bridge circuit driven by the redundant MCU are isolated, and mutual interference between driving signals of the master control MCU1 and the backup MCU2 is prevented. The circuit design improves the function safety of the double-control EPB electronic parking system in use.

Description

Technical Field

[0001] The utility model relates to the technical field of an EPB driving circuit, in particular to a circuit for switching driving signals of a dual-controlled EPBH bridge. Background Art

[0002] New energy vehicles have removed the mechanical P gear lock to reduce vehicle weight, so new energy vehicles have higher functional safety requirements for the EPB electronic parking system. In order to meet regulatory requirements, dual MCUs are generally used in the architecture to drive the same parking H-bridge circuit to prevent single point failure. Usually, the two MCUs are driven by direct parallel connection. This method has the following two problems:

[0003] 1. The main control MCU1 may misidentify the H-bridge drive circuit or diagnose faults due to interference from the backup MCU2's drive signal.

[0004] 2. When the main control MCU1 fails, the system function is degraded, and the backup MCU chip will identify or diagnose the fault of the H-bridge drive circuit, resulting in signal recognition errors due to the abnormal state of the main MCU1. Utility Model Content

[0005] In order to solve the problems existing in the background technology, the utility model proposes a circuit for switching dual-control EPBH bridge drive signals.

[0006] The technical solution of the utility model is achieved in this way:

[0007] The utility model comprises two parts: a main control part and a backup part.

[0008] The main control part includes a main control power management module and a main control MCU1 micro control unit connected in sequence, the main control power management module outputs power to the main control MCU1 micro control unit, and the main control MCU1 micro control unit outputs an H-bridge drive signal PWM1 to the drive signal switching module;

[0009] The backup part includes a backup power management module and a backup MCU2 microcontroller unit connected in sequence, the backup power management module outputs power to the backup MCU2 microcontroller unit, and the backup MCU2 microcontroller unit outputs an H-bridge drive signal PWM2 to the drive signal switching module;

[0010] The main control MCU1 microcontroller unit and the backup MCU2 microcontroller unit are both connected to the driving voltage switching module, the driving signal switching module and the driving voltage switching module are both connected to the parking H-bridge pre-driver chip, the parking H-bridge pre-driver chip is further connected to the parking drive H-bridge circuit, and the driving signal switching module performs channel control of the input H-bridge driving signal PWM1 and the H-bridge driving signal PWM2 to ensure that at the same time, only one of the driving signals is transmitted to the parking H-bridge pre-driver chip, thereby controlling the parking drive H-bridge circuit.

[0011] The main control MCU1 micro control unit is communicatively connected with the backup MCU2 micro control unit.

[0012] The PS1 / TXD0 pin of the micro-control chip MCU1 is connected to the PS0 / RXD0 pin of the micro-control chip MCU2, and the PS0 / RXD0 pin of the micro-control chip MCU1 is connected to the PS1 / TXD0 pin of the micro-control chip MCU2.

[0013] The main control power management module includes a power management chip U5, a VSUP pin of the power management chip U5 is connected to the vehicle power VBAT, an RST pin of the power management chip U5 is connected to the VCC1 pin via a resistor R16, and a VDD pin outputs the power VCC1.

[0014] The backup power management module includes a power management chip U6, a VSUP pin of the power management chip U6 is connected to the vehicle power VBAT, an RST pin of the power management chip U6 is connected to the VCC2 pin via a resistor R17, and a VDD pin outputs the power VCC2.

[0015] The main control MCU1 microcontroller unit includes a microcontroller chip MCU1, and the microcontroller chip MCU1 serves as the main control microcontroller chip; the backup MCU2 microcontroller unit includes a microcontroller chip MCU2, and the microcontroller chip MCU2 serves as the backup microcontroller chip.

[0016] The drive signal switching module includes a drive signal switching chip U4; the PP1 pin of the micro-control chip MCU1 is connected to the 1B1 pin of the drive signal switching chip U4, and the PP0 pin of the micro-control chip MCU1 is connected to the 2B1 pin of the drive signal switching chip U4; the PP2 pin of the micro-control chip MCU2 is connected to the S pin of the drive signal switching chip U4, the S pin of the drive signal switching chip U4 is grounded via a resistor R18, the PP1 pin of the micro-control chip MCU2 is connected to the 1B2 pin of the drive signal switching chip U4, and the PP0 pin of the micro-control chip MCU2 is connected to the 2B2 pin of the drive signal switching chip U4.

[0017] The driving voltage switching module includes a transistor Q2, a transistor Q3 and a composite transistor U2. The composite transistor U2 is mainly composed of two transistors. The emitter of the first transistor of the composite transistor U2 is grounded, the base pin is connected to the PB0 driving port of the microcontroller chip MCU1, and the collector is connected to the base of the transistor Q3 via a resistor R6. The emitter of the second transistor of the composite transistor U2 is grounded, the base pin is connected to the PB0 driving port of the microcontroller chip MCU2, and the collector is connected to the base of the transistor Q2 via a resistor R7. The emitters of the transistors Q2 and Q3 are connected to the power supply VCC2 and the power supply VCC1 respectively. The collectors of the transistors Q2 and Q3 are connected together and serve as the output end of the power supply VCC.

[0018] This module can ensure that when the main power management output power VCC1 fails, the power supply VCC2 can still be used to power the drive signal switching chip U4 and the H-bridge pre-driver chip U7.

[0019] The parking H-bridge pre-driver chip includes a parking H-bridge pre-driver chip U7; the 1A pin of the drive signal switching chip U4 is connected to the IN1 pin of the parking H-bridge pre-driver chip U7, the 2A pin of the drive signal switching chip U4 is connected to the IN2 pin of the parking H-bridge pre-driver chip U7, the VCC pin of the drive signal switching chip U4 is connected to the power supply VCC, and the OE pin of the drive signal switching chip U4 is grounded.

[0020] The parking drive H-bridge circuit includes MOS tubes Q5 to Q8, the source of MOS tube Q6 and the drain of MOS tube Q7 are connected to one end of the motor M, the other end of the motor M is connected to the source of MOS tube Q5 and the drain of MOS tube Q8, the drains of MOS tube Q6 and MOS tube Q5 are connected to the vehicle power supply VBAT, and the sources of MOS tube Q7 and MOS tube Q8 are grounded;

[0021] The GH1 pins of the parking H-bridge pre-driver chip U7 are all connected to the gate of the MOS tube Q5, the GH2 pins of the parking H-bridge pre-driver chip U7 are all connected to the gate of the MOS tube Q6, the GL1 pins of the parking H-bridge pre-driver chip U7 are all connected to the gate of the MOS tube Q8, and the GL2 pins of the parking H-bridge pre-driver chip U7 are all connected to the gate of the MOS tube Q7.

[0022] The SH1 pins of the parking H-bridge pre-driver chip U7 are connected to the drain of the MOS tube Q8 and the source of the MOS tube Q5, the SH2 pins of the parking H-bridge pre-driver chip U7 are connected to the drain of the MOS tube Q7 and the source of the MOS tube Q6, and the SL2 pins of the parking H-bridge pre-driver chip U7 are connected to the source of the MOS tube Q7 and the source of the MOS tube Q8.

[0023] Beneficial effects of the utility model:

[0024] The utility model isolates the signal of the redundant MCU driving the same parking H-bridge circuit through the driving signal switching module, thereby preventing the mutual interference between the driving signals of the main control MCU1 and the backup MCU2. This circuit design improves the functional safety of the dual-control EPB electronic parking system. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of a circuit for switching dual-control EPBH bridge drive signals;

[0026] Figure 2 The schematic diagram of a circuit for switching dual-controlled EPBH bridge drive signals. DETAILED DESCRIPTION

[0027] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0028] like Figure 1 As shown, the circuit includes two parts: the main control part and the backup part;

[0029] The main control part includes a main power management module 1 and a main MCU1 microcontroller unit connected in sequence. The main power management module 1 outputs power to the main MCU1 microcontroller unit, and the main MCU1 microcontroller unit outputs an H-bridge drive signal PWM1 to the drive signal switching module; the backup part includes a backup power management module 2 and a backup MCU2 microcontroller unit connected in sequence. The backup power management module 2 outputs power to the backup MCU2 microcontroller unit, and the backup MCU2 microcontroller unit outputs an H-bridge drive signal PWM2 to the drive signal switching module.

[0030] The main control MCU1 microcontroller unit and the backup MCU2 microcontroller unit are both connected to the driving voltage switching module, the driving signal switching module and the driving voltage switching module are both connected to the parking H-bridge pre-driver chip, and the parking H-bridge pre-driver chip is further connected to the parking drive H-bridge circuit. The driving signal switching module controls the channel of the input H-bridge driving signal PWM1 and the H-bridge driving signal PWM2 to ensure that at the same time, only one of the driving signals is transmitted to the parking H-bridge pre-driver chip, thereby controlling the parking drive H-bridge circuit.

[0031] When the main control MCU1 microcontroller unit is working, the signal switching module is driven to connect PWM1 to PWM and disconnect PWM2 from PWM, so that the main control MCU1 microcontroller unit controls the parking H-bridge pre-driver chip to drive the parking H-bridge circuit, and the backup MCU2 microcontroller unit does not work. The above PWM can represent the port name or signal. In the circuit schematic diagram, it refers to the IN1 and IN2 ports of the pre-driver chip U7. PWM1 represents the signals M_IN1_IN and M_IN2_IN. Similarly, PWM2 represents S_IN1_IN and S_IN2_IN, which expresses the connection relationship between the ports.

[0032] When the main control MCU1 microcontroller unit fails, the backup MCU2 microcontroller unit starts working, connects the PWM2 signal with PWM, and disconnects PWM1 from PWM, so that the backup MCU2 microcontroller unit controls the parking H-bridge pre-driver chip and then drives the parking H-bridge circuit.

[0033] The main control MCU1 microcontroller unit and the backup MCU2 microcontroller unit are connected in communication, and the communication method is USART serial port for data exchange.

[0034] like Figure 2 As shown, the main power management module 1 includes a power management chip U5, a No. VSUP pin of the power management chip U5 is connected to the vehicle power supply VBAT, a No. 22 RST pin of the power management chip U5 is connected to the No. 28 VDD pin via a resistor R16, and the No. 28 VDD pin outputs the power supply VCC1; the backup power management module 2 includes a power management chip U6, a No. VSUP pin of the power management chip U6 is connected to the vehicle power supply VBAT, a No. 22 RST pin of the power management chip U6 is connected to the No. 28 VDD pin via a resistor R17, and the No. 28 VDD pin outputs the power supply VCC2.

[0035] The main power management module 1 includes a power management chip U5, the VSUP pin of the power management chip U5 is connected to the vehicle power supply VBAT, the RST pin of the power management chip U5 is connected to the VCC1 pin via a resistor R16, and the VDD pin outputs the power supply VCC1; the backup power management module 2 includes a power management chip U6, the VSUP pin of the power management chip U6 is connected to the vehicle power supply VBAT, the RST pin of the power management chip U6 is connected to the VCC2 pin via a resistor R17, and the VDD pin outputs the power supply VCC2.

[0036] The main control MCU1 microcontroller unit includes a microcontroller chip MCU1, and the microcontroller chip MCU1 is used as the main control microcontroller chip; the backup MCU2 microcontroller unit includes a microcontroller chip MCU2, and the microcontroller chip MCU2 is used as the backup microcontroller chip.

[0037] The No. 9 VDD1 pin, No. 77 VDDX pin, No. 60 VRH pin, No. 59 VDDA pin, No. 31 VSSPLL pin, and No. 29 VDDR pin of the main microcontroller chip MCU1 are all connected to the power supply VCC1, and the No. 10 VSS1 pin, No. 76 VSSX pin, No. 67 VREGEN pin, No. 62 VSSA pin, No. 61 VRL pin, No. 33 VSSPLL pin, No. 32 XFC pin, and No. 28 VSSR pin of the microcontroller chip MCU1 are all connected to ground.

[0038] The No. 3 PP1 pin of the microcontroller chip MCU1 is connected to the No. 2 1B1 pin of the drive signal switching chip U4 as the M_IN1_IN interface, and the No. 4 PP0 pin of the microcontroller chip MCU1 is connected to the No. 5 2B1 pin of the drive signal switching chip U4 as the M_IN2_IN interface.

[0039] The backup microcontroller chip MCU2's VDD1 pin No. 9, VDDX pin No. 77, VRH pin No. 60, VDDA pin No. 59, VSSPLL pin No. 31, and VDDR pin No. 29 are all connected to the power supply VCC2, and the microcontroller chip MCU2's VSS1 pin No. 10, VSSX pin No. 76, VREGEN pin No. 67, VSSA pin No. 62, VRL pin No. 61, VSSPLL pin No. 33, XFC pin No. 32, and VSSR pin No. 28 are all connected to ground.

[0040] The microcontroller chip MCU1 is used as the main microcontroller chip, and the microcontroller chip MCU2 is used as the backup microcontroller chip. The 64th PS1 / TXD0 pin of the microcontroller chip MCU1 is connected to the 63rd PS0 / RXD0 pin of the microcontroller chip MCU2 as M_TXD_S, and the 63rd PS0 / RXD0 pin of the microcontroller chip MCU1 is connected to the 64th PS1 / TXD0 pin of the microcontroller chip MCU2 as M_RXD_S. The communication mode is USART serial port mode, and its function is to enable the backup MCU2 to monitor the running status of the main MCU1.

[0041] The driving signal switching module includes a driving signal switching chip U4; the PP1 pin of the microcontroller chip MCU1 is connected to the 1B1 pin of the driving signal switching chip U4, and the PP0 pin of the microcontroller chip MCU1 is connected to the 2B1 pin of the driving signal switching chip U4; the PP2 pin of the microcontroller chip MCU2 is connected to the S pin of the driving signal switching chip U4, and the S pin of the driving signal switching chip U4 is grounded via a resistor R18, the PP1 pin of the microcontroller chip MCU2 is connected to the 1B2 pin of the driving signal switching chip U4, and the PP0 pin of the microcontroller chip MCU2 is connected to the 2B2 pin of the driving signal switching chip U4.

[0042] The driving voltage switching module includes transistors Q2, Q3 and composite transistor U2. Composite transistor U2 is mainly composed of two transistors. The emitter of the first transistor of composite transistor U2 is grounded, the base pin is connected to the PB0 driving port of the microcontroller chip MCU1, and the collector is connected to the base of transistor Q3 through resistor R6. The emitter of the second transistor of composite transistor U2 is grounded, the base pin is connected to the PB0 driving port of the microcontroller chip MCU2, and the collector is connected to the base of transistor Q2 through resistor R7. The emitters of transistors Q2 and Q3 are connected to power supply VCC2 and power supply VCC1 respectively. The collectors of transistors Q2 and Q3 are connected together and serve as the output end of power supply VCC. This module can ensure that when the output power supply VCC1 of the main control power management fails, the power supply VCC2 can still be used to power the driving signal switching chip U4 and the H-bridge pre-driver chip U7.

[0043] The No. 2 PP2 pin of the microcontroller chip MCU2 is connected to the No. 1 S pin of the drive signal switching chip U4 as the S_STATE interface, the No. 1 S pin of the drive signal switching chip U4 is grounded via resistor R18, the No. 3 PP1 pin of the microcontroller chip MCU2 is connected to the No. 4 1B2 pin of the drive signal switching chip U4 as the S_IN1_IN interface, and the No. 4 PP0 pin of the microcontroller chip MCU2 is connected to the No. 6 2B2 pin of the drive signal switching chip U4 as the S_IN2_IN interface.

[0044] like Figure 2 As shown, the parking signal switching chip U44 No. 1A pin is used as the IN1 interface, and the No. 7 2A pin is used as the IN2 interface, which are respectively connected to the No. 2 IN1 pin and the No. 3 IN2 pin of the parking H-bridge pre-driver chip U2. The No. 16 VCC pin of the drive signal switching chip U4 is connected to the power supply VCC, and the No. 15 OE pin and the No. 8 GND pin are grounded.

[0045] like Figure 2 As shown, the parking drive H-bridge circuit includes MOS tubes Q5 to Q8, the source of MOS tube Q6 and the drain of MOS tube Q7 are connected to one end of the motor M, the other end of the motor M is connected to the source of MOS tube Q5 and the drain of MOS tube Q8, the drains of MOS tube Q6 and MOS tube Q5 are connected to the vehicle power supply VBAT, and the sources of MOS tube Q7 and MOS tube Q8 are grounded.

[0046] The parking H-bridge pre-driver chip includes a parking H-bridge pre-driver chip U7; No. 18 GH1 pins of the parking H-bridge pre-driver chip U7 in the parking H-bridge pre-driver chip are all connected to the gate of the MOS tube Q7, No. 26 GH2 pins of the parking H-bridge pre-driver chip U7 are all connected to the gate of the MOS tube Q6, No. 20 GL1 pins of the parking H-bridge pre-driver chip U7 are all connected to the gate of the MOS tube Q8, and No. 24 GL2 pins of the parking H-bridge pre-driver chip U7 are all connected to the gate of the MOS tube Q7.

[0047] The No. 19 SH1 pin of the parking H-bridge pre-driver chip U7 is connected to the drain of the MOS tube Q8, the No. 25 SH2 pin of the parking H-bridge pre-driver chip U7 is connected to the drain of the MOS tube Q7, and the No. 23 SL2 pin of the parking H-bridge pre-driver chip U7 is connected to the source of the MOS tube Q7 and the source of the MOS tube Q8.

[0048] In the specific implementation, the models of MCU1 and MCU2 are S9S12P128JOMQK, the models of power management chips U5 and U6 are MCZ33904A5EK, the model of parking H-bridge pre-driver chip U7 is DRV8702, and the drive signal switching chip U4 is CBT3257APW-Q100.

[0049] The specific working mode of the utility model includes two modes: normal mode and failure mode;

[0050] Normal mode: The backup main microcontroller chip acts as a watchdog to monitor the working status of the main microcontroller chip MCU1 in real time.

[0051] The main microcontroller chip MCU1 works normally, and sends out H-bridge drive signals of PWM waveform from the PP1 and PP2 pins, and the PB0 pin sends out a high level. The PB0 pin of the backup MCU2 sends out a low level, at which time the transistor Q3 is turned on and Q2 is turned off, so that VCC1 is loaded onto VCC.

[0052] The PP2 pin of the backup microcontroller chip MCU2 outputs a low level, and at this time, the S pin of the drive signal switching chip U4 receives a low level, so that the 1B1 pin interface of the drive signal switching chip U4 is connected to the 1A pin interface, and the 2B1 pin interface of the drive signal switching chip U4 is connected to the 2A pin interface; the 1B2 pin interface of the drive signal switching chip U4 is not connected to the 1A pin interface, and the 2B2 pin interface of the drive signal switching chip U4 is not connected to the 2A pin interface. That is, the M_IN1_IN interface of the drive signal switching chip U4 is connected to the IN1 interface, and the M_IN2_IN interface of the drive signal switching chip U4 is connected to the IN2 interface; the S_IN1_IN interface of the drive signal switching chip U4 is not connected to the IN1 interface, and the S_IN2_IN interface of the drive signal switching chip U4 is not connected to the IN2 interface.

[0053] The above operation enables the H-bridge driving signal of the main control part to be transmitted to the parking H-bridge pre-driving chip U7, thereby controlling the action of the parking driving H-bridge circuit. In the backup part, since the driving signal cannot be loaded onto the parking H-bridge pre-driving chip U7, it will not interfere with the normal action of the main control unit.

[0054] Failure Mode:

[0055] At this time, the main microcontroller chip MCU1 fails and cannot issue an H-bridge driving signal with a PWM waveform.

[0056] When the main microcontroller chip MCU1 works abnormally and cannot send out the H-bridge drive signal, the PB0 pin sends out a low level, and the PB0 pin of the backup MCU2 sends out a high level. At this time, transistor Q2 is turned on and Q3 is turned off, so that VCC2 is loaded onto VCC.

[0057] The S_STATE interface / PP2 pin of the backup microcontroller chip MCU2 outputs a high level, and at this time, the S pin of the drive signal switching chip U4 receives a high level, so that the 1B1 pin interface of the drive signal switching chip U4 is disconnected from the 1A pin interface, and the 2B1 pin interface of the drive signal switching chip U4 is disconnected from the 2A pin interface; the 1B2 pin interface of the drive signal switching chip U4 is connected to the 1A pin interface, and the 2B2 pin interface of the drive signal switching chip U4 is connected to the 2A pin interface. That is, the M_IN1_IN interface of the drive signal switching chip U4 is disconnected from the IN1 interface, and the M_IN2_IN interface of the drive signal switching chip U4 is disconnected from the IN2 interface; the S_IN1_IN interface of the signal channel selection chip U4 is connected to the IN1 interface, and the S_IN2_IN interface of the signal channel selection chip U4 is connected to the IN2 interface.

[0058] The above operation makes it impossible for the H-bridge driving signal of the main control part to be transmitted to the parking H-bridge pre-driver chip U7, and it is impossible to control the action of the parking drive H-bridge circuit. However, in the backup part, the driving signal is loaded onto the parking H-bridge pre-driver chip U7, which can control the action of the parking drive H-bridge circuit and play a role of failure backup.

Claims

1. A circuit for dual-control EPBH bridge drive signal switching, characterized in that: It consists of two parts: the main control part and the backup part; The main control part comprises a main control power management module (1) and a main control MCU1 micro control unit which are connected in sequence. The main control power management module (1) outputs power to supply power to the main control MCU1 micro control unit, and the main control MCU1 micro control unit outputs an H-bridge drive signal PWM1 to the drive signal switching module. The backup part includes a backup power management module (2) and a backup MCU2 microcontroller unit connected in sequence, the backup power management module (2) outputs power to supply power to the backup MCU2 microcontroller unit, and the backup MCU2 microcontroller unit outputs an H-bridge drive signal PWM2 to the drive signal switching module; The main control MCU1 microcontroller unit and the backup MCU2 microcontroller unit are both connected to the drive voltage switching module. The drive signal switching module and the drive voltage switching module are both connected to the parking H-bridge pre-drive chip, and the parking H-bridge pre-drive chip is then connected to the parking drive H-bridge circuit. The drive signal switching module performs channel control on the input H-bridge drive signal PWM1 and the H-bridge drive signal PWM2 to ensure that only one of the drive signals is transmitted to the parking H-bridge pre-drive chip at the same time, thereby controlling the parking drive H-bridge circuit.

2. A circuit for dual-control EPBH bridge drive signal switching according to claim 1, characterized in that: The main control MCU1 micro control unit and the backup MCU2 micro control unit are connected in communication; The main control MCU1 microcontroller unit includes a microcontroller chip MCU1, and the microcontroller chip MCU1 serves as the main control microcontroller chip; the backup MCU2 microcontroller unit includes a microcontroller chip MCU2, and the microcontroller chip MCU2 serves as the backup microcontroller chip.

3. A circuit for switching dual-controlled EPBH bridge drive signals according to claim 2, characterized in that: The PS1 / TXD0 pin of the micro-control chip MCU1 is connected to the PS0 / RXD0 pin of the micro-control chip MCU2, and the PS0 / RXD0 pin of the micro-control chip MCU1 is connected to the PS1 / TXD0 pin of the micro-control chip MCU2.

4. The circuit for switching dual-controlled EPBH bridge drive signals according to claim 1, characterized in that: The main control power management module (1) comprises a power management chip U5, a VSUP pin of the power management chip U5 is connected to the vehicle power supply VBAT, an RST pin of the power management chip U5 is connected to the VCC1 pin via a resistor R16, and a VDD pin outputs the power supply VCC1; The backup power management module (2) comprises a power management chip U6, a VSUP pin of the power management chip U6 is connected to the vehicle power supply VBAT, an RST pin of the power management chip U6 is connected to the VCC2 pin via a resistor R17, and a VDD pin outputs the power supply VCC2.

5. The circuit for switching dual-control EPBH bridge drive signals according to claim 2, characterized in that: The drive signal switching module includes a drive signal switching chip U4; the PP1 pin of the micro-control chip MCU1 is connected to the 1B1 pin of the drive signal switching chip U4, and the PP0 pin of the micro-control chip MCU1 is connected to the 2B1 pin of the drive signal switching chip U4; the PP2 pin of the micro-control chip MCU2 is connected to the S pin of the drive signal switching chip U4, the S pin of the drive signal switching chip U4 is grounded via a resistor R18, the PP1 pin of the micro-control chip MCU2 is connected to the 1B2 pin of the drive signal switching chip U4, and the PP0 pin of the micro-control chip MCU2 is connected to the 2B2 pin of the drive signal switching chip U4.

6. A circuit for switching dual-controlled EPBH bridge drive signals according to claim 2, characterized in that: The driving voltage switching module includes a transistor Q2, a transistor Q3 and a composite transistor U2. The composite transistor U2 is mainly composed of two transistors. The emitter of the first transistor of the composite transistor U2 is grounded, the base pin is connected to the PB0 driving port of the microcontroller chip MCU1, and the collector is connected to the base of the transistor Q3 via a resistor R6. The emitter of the second transistor of the composite transistor U2 is grounded, the base pin is connected to the PB0 driving port of the microcontroller chip MCU2, and the collector is connected to the base of the transistor Q2 via a resistor R7. The emitters of the transistors Q2 and Q3 are connected to the power supply VCC2 and the power supply VCC1 respectively. The collectors of the transistors Q2 and Q3 are connected together and serve as the output end of the power supply VCC.

7. The circuit for switching dual-controlled EPBH bridge drive signals according to claim 5, characterized in that: The parking H-bridge pre-driver chip includes a parking H-bridge pre-driver chip U7; the 1A pin of the drive signal switching chip U4 is connected to the IN1 pin of the parking H-bridge pre-driver chip U7, the 2A pin of the drive signal switching chip U4 is connected to the IN2 pin of the parking H-bridge pre-driver chip U7, the VCC pin of the drive signal switching chip U4 is connected to the power supply VCC, and the OE pin of the drive signal switching chip U4 is grounded.

8. The circuit for switching dual-control EPBH bridge drive signals according to claim 1, characterized in that: The parking drive H-bridge circuit includes MOS tubes Q5 to Q8, the source of MOS tube Q6 and the drain of MOS tube Q7 are connected to one end of the motor M, the other end of the motor M is connected to the source of MOS tube Q5 and the drain of MOS tube Q8, the drains of MOS tube Q6 and MOS tube Q5 are connected to the vehicle power supply VBAT, and the sources of MOS tube Q7 and MOS tube Q8 are grounded; The GH1 pins of the parking H-bridge pre-driver chip U7 are all connected to the gate of the MOS tube Q5, the GH2 pins of the parking H-bridge pre-driver chip U7 are all connected to the gate of the MOS tube Q6, the GL1 pins of the parking H-bridge pre-driver chip U7 are all connected to the gate of the MOS tube Q8, and the GL2 pins of the parking H-bridge pre-driver chip U7 are all connected to the gate of the MOS tube Q7; The SH1 pins of the parking H-bridge pre-driver chip U7 are connected to the drain of the MOS tube Q8 and the source of the MOS tube Q5, the SH2 pins of the parking H-bridge pre-driver chip U7 are connected to the drain of the MOS tube Q7 and the source of the MOS tube Q6, and the SL2 pins of the parking H-bridge pre-driver chip U7 are connected to the source of the MOS tube Q7 and the source of the MOS tube Q8.

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