Commercial vehicle left and right rearview mirror drive circuit and control method

Abstract

The present invention proposes a left and right rearview mirror drive circuit for a commercial vehicle and a control method thereof, comprising full-bridge drive circuits for the left and right rearview mirrors. The first full-bridge drive circuit comprises a first half-bridge circuit and a second half-bridge circuit connected to a left-right direction adjustment motor; the second full-bridge drive circuit comprises a second half-bridge circuit and a third half-bridge circuit, both connected to an up-down direction adjustment motor; and all three half-bridge circuits comprise an intelligent high-side power driver chip, an intelligent low-side power driver chip, and an AD detection circuit, wherein the intelligent high-side power driver chip is connected to the AD detection circuit, and the intelligent high-side power driver chip, the intelligent low-side power driver chip, and the AD detection circuit are all connected to an MCU controller. The present invention has dual software and hardware protection capabilities, improving the cost-effectiveness of the left and right rearview mirror drive circuits for commercial vehicles; it has strong portability, reusability, and reference value, while reducing product development time and development costs.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile body control, and in particular to a driving circuit for left and right rearview mirrors of a commercial vehicle and a control method thereof, specifically a full-bridge driving circuit for left and right rearview mirrors of a 24V commercial vehicle. Background Art

[0002] The car rearview mirror is an important safety feature. It can reflect the situation behind, to the sides and below the car. By adjusting the rearview mirror up and down, left and right, the driver can indirectly see the situation in these positions. It plays the role of a "second eye", expanding the driver's field of view and ensuring driving safety.

[0003] Currently, commercial vehicle rearview mirrors on the market are generally driven by relays or full-bridge intelligent power driver chips. Relays come in two types: plug-in and PCB. Plug-in relays are larger and must be mounted outside the product housing, making them unsuitable for products requiring sealing, waterproofing, and noise reduction. Regardless of the relay type, a significant drawback is their lack of short-circuit protection. Relays operate in open-loop control and lack current feedback detection or overcurrent, overheating, or short-circuit protection. In practice, to enhance these protections, a high-power, milliohm-level sense resistor is connected between the relay contacts and the rearview mirror motor. A differential amplifier detection circuit is also required. This detection circuit feeds the sensed voltage signal into the MCU's AD detection channel. When the current flowing through the sense resistor is abnormally high or the external motor short-circuits, the voltage signal detected by the MCU's AD detection port increases. At this point, the MCU controls the relay coil's IO port to shut down the high-level output, thereby shutting off the relay output and implementing the relay's overcurrent and short-circuit protection.

[0004] However, the aforementioned control and protection strategies still present a significant risk. Signal conversion in the detection circuit, debouncing of the AD detection, software identification and judgment algorithms, and even software shutdown all require time. This prevents the relay's overcurrent and short-circuit protection from being properly activated. Prolonged operation and protection can damage the relay, ultimately leading to its destruction. Furthermore, the aforementioned control and protection strategies rely excessively on software. If the MCU software malfunctions, overcurrent and short-circuit protection capabilities will be lost. Furthermore, the inherent limitations of relays, such as size, weight, noise, and lifespan, are making it increasingly difficult to meet the demands of intelligent, safe, and lightweight vehicles.

[0005] There are very few 24V full-bridge intelligent power driver chips available on the market. These chips are entirely imported, resulting in high prices and long procurement cycles. Furthermore, a rearview mirror has two motors, each requiring separate drive for up, down, left, and right adjustments. Even if the drive channels are combined, three half-bridge drive channels are required: left and right / up and down, to form two full-bridge drives. The left and right mirrors require a total of six half-bridge drive channels, requiring a large number of 24V full-bridge driver chips. This further increases costs and sharply reduces product competitiveness, making it unsuitable for projects with short development cycles and high cost requirements.

[0006] To solve the above problems, it is necessary to build a driving circuit for the six half-bridge driving channels of the left and right rearview mirrors. Summary of the Invention

[0007] To address the technical problems of existing commercial vehicle rearview mirror drive mechanisms, such as large size, high cost, and excessive reliance on control software, the present invention proposes a commercial vehicle left and right rearview mirror drive circuit and control method, which can accurately drive the left and right rearview mirrors of the commercial vehicle and has overcurrent and short-circuit protection functions, thereby comprehensively improving the cost-effectiveness of the commercial vehicle left and right rearview mirror drive circuit.

[0008] In order to achieve the above-mentioned purpose, the technical solution of the present invention is implemented as follows: a left and right rearview mirror drive circuit for a commercial vehicle, including a full-bridge drive circuit for a left rearview mirror and a right rearview mirror, the full-bridge drive circuit including a first full-bridge drive circuit and a second full-bridge drive circuit, the first full-bridge drive circuit is connected to the left and right direction adjustment motor of the left rearview mirror or the right rearview mirror, and the second full-bridge drive circuit is connected to the up and down direction adjustment motor of the left rearview mirror or the right rearview mirror; the first full-bridge drive circuit includes a first half-bridge circuit and a second half-bridge circuit, the first half-bridge circuit and the second half-bridge circuit are both connected to the left and right direction adjustment motor; the second full-bridge drive circuit includes a second half-bridge circuit and a third half-bridge circuit, the second half-bridge circuit and the third half-bridge circuit are both connected to the up and down direction adjustment motor The first half-bridge circuit, the second half-bridge circuit and the third half-bridge circuit all include an intelligent high-side power driver chip, an intelligent low-side power driver chip and an AD detection circuit. The intelligent high-side power driver chip is connected to the AD detection circuit. The intelligent high-side power driver chip, the intelligent low-side power driver chip and the AD detection circuit are all connected to the MCU controller. The output ends of the intelligent high-side power driver chip and the intelligent low-side power driver chip are connected in parallel to the up and down direction adjustment motor or the left and right direction adjustment motor. The intelligent high-side power driver chip is used for power switching of the up and down direction adjustment motor or the left and right direction adjustment motor, and the intelligent low-side power driver chip is used for ground switching of the up and down direction adjustment motor or the left and right direction adjustment motor.

[0009] Preferably, the current detection feedback output pin of the intelligent high-side power driver chip is connected to the AD detection circuit, and the AD detection circuit is connected to the AD detection IO port of the MCU controller.

[0010] Preferably, the AD detection circuit includes a sampling resistor, a first current limiting resistor and a first filter capacitor, one end of the sampling resistor and the first current limiting resistor are both connected to the current detection feedback output pin of the intelligent high-side power driver chip, the other end of the first current limiting resistor is connected to the AD detection IO port of the MCU controller, the other end of the sampling resistor is connected in series with one end of the first filter capacitor, the other end of the first filter capacitor is connected to the other end of the first current limiting resistor, and the other end of the sampling resistor and one end of the first filter capacitor are both grounded.

[0011] Preferably, when a motor of the left rearview mirror or the right rearview mirror needs to work, the MCU controller first turns on the intelligent low-side power driver chip of the full-bridge drive circuit that drives the motor, and after a delay of 20ms, the MCU controller turns on the intelligent high-side power driver chip of the full-bridge drive circuit that drives the motor; when the motor needs to stop, the MCU controller first turns off the intelligent high-side power driver chip that drives the motor, and after a delay of 20ms, the MCU controller turns off the intelligent high-side power driver chip that drives the motor.

[0012] Preferably, the IN enable terminals of the intelligent high-side power driver chip and the intelligent low-side power driver chip are both connected to the control IO port of the MCU controller through a current limiting resistor; the current diagnosis enable terminal of the intelligent high-side power driver chip is connected to the control IO port of the MCU controller through a current limiting resistor, and the fault diagnosis enable terminal of the intelligent low-side power driver chip is connected to the control IO port of the MCU controller through a current limiting resistor; the fault feedback output terminal of the intelligent low-side power driver chip is respectively connected to the detection IO port of the MCU controller and one end of the first pull-up resistor, and the other end of the first pull-up resistor is connected to the power supply VCC; when the fault diagnosis enable terminal input is high level, the fault feedback output terminal outputs a feedback signal, and when the fault diagnosis enable terminal input is low level, the fault feedback output terminal turns off the output.

[0013] Preferably, the output end of the intelligent high-side power driver chip is connected to the up and down direction adjustment motor or the left and right direction adjustment motor through a protection circuit; the protection circuit includes a second pull-up resistor and a second filter capacitor, the second pull-up resistor and the second filter capacitor are connected in parallel, one end of the second pull-up resistor and the second filter capacitor are both connected to the output end of the intelligent high-side power driver chip, and the other ends of the second pull-up resistor and the second filter capacitor are both grounded; the output end of the intelligent low-side power driver chip is connected to one end of the third filter capacitor, and the other end of the third filter capacitor is grounded; the ground end of the intelligent high-side power driver chip is grounded through a second current limiting resistor and an anti-reverse connection diode, and the ground end of the intelligent low-side power driver chip is directly grounded; the power supply ends of the intelligent high-side power driver chip and the intelligent low-side power driver chip are both connected to the power supply through a filter capacitor.

[0014] Preferably, the first half-bridge circuit is used to drive the left adjustment of the left and right direction adjustment motor, the second half-bridge circuit is used to drive the right adjustment of the left and right direction adjustment motor and the up adjustment of the up and down direction adjustment motor, and the third half-bridge circuit is used for the down adjustment of the up and down direction adjustment motor; the driving current of the intelligent high-side power driver chip and the intelligent low-side power driver chip of the second half-bridge is more than twice the larger of the rated currents of the up and down direction adjustment motor and the left and right direction adjustment motor.

[0015] Preferably, when the left adjustment and downward adjustment of the left rearview mirror or the right rearview mirror work simultaneously, the intelligent low-side power driver chip of the second half-bridge circuit shared by the first full-bridge drive circuit and the second full-bridge drive circuit is turned on and bears the driving current of the two motors; when the right adjustment and upward adjustment of the left rearview mirror or the right rearview mirror work simultaneously, the HSD of the second half-bridge circuit shared by the first full-bridge drive circuit and the second full-bridge drive circuit is turned on and bears the driving current of the two motors.

[0016] Preferably, the control method is as follows: when the left or right adjustment motor of the left rearview mirror or the right rearview mirror needs to be adjusted to the left, the MCU controller first turns on the intelligent low-side power driver chip of the second half-bridge circuit to ground its output, and then turns on the intelligent high-side power driver chip of the first half-bridge circuit to output a high level, thereby realizing left adjustment drive of the left or right adjustment motor; when the left or right adjustment motor of the left or right rearview mirror needs to be adjusted to the right, the MCU controller first turns on the intelligent low-side power driver chip of the first half-bridge circuit to ground its output, and then turns on the intelligent high-side power driver chip of the second half-bridge circuit to output a high level, thereby realizing right adjustment drive of the left or right adjustment motor;

[0017] When the up and down adjustment motor of the left rearview mirror or the right rearview mirror needs to be adjusted downward, the MCU controller first turns on the intelligent low-side power driver chip of the second half-bridge circuit to ground its output, and then turns on the intelligent high-side power driver chip of the third half-bridge circuit to output a high level, thereby realizing the downward adjustment drive of the left and right adjustment motors; when the up and down adjustment motor of the left rearview mirror or the right rearview mirror needs to be adjusted upward, the MCU controller first turns on the intelligent low-side power driver chip of the third half-bridge circuit to ground its output, and then turns on the intelligent high-side power driver chip of the second half-bridge circuit to output a high level, thereby realizing the upward adjustment drive of the up and down adjustment motors.

[0018] Preferably, when the AD detection circuit detects that the current of the up and down direction adjustment motor or the left and right direction adjustment motor increases abnormally, the control IO port of the MCU controller outputs a low level to shut down the working intelligent low-side power driver chip and the intelligent high-side power driver chip, thereby achieving overcurrent or short circuit protection; when the fault feedback output end of the intelligent low-side power driver chip outputs a low level, the control IO port of the MCU controller outputs a low level to shut down the working intelligent low-side power driver chip and the intelligent high-side power driver chip, thereby achieving overcurrent or short circuit protection.

[0019] Beneficial effects of the present invention: The present invention is a standard commercial vehicle left and right rearview mirror drive circuit and control method, which uses a high-side intelligent power driver chip (HSD) and a low-side intelligent power driver chip (LSD) to form a half-bridge drive circuit, and uses a minimum peripheral circuit combination to build a full-bridge drive circuit. Compared with traditional devices, the high-side and low-side driver chips have overvoltage protection, overcurrent protection, overtemperature protection, short-circuit protection and diagnostic feedback mechanisms. Through the software detection and logic control of the MCU, the present invention has dual protection capabilities of software and hardware, improving the cost-effectiveness of the commercial vehicle left and right rearview mirror drive circuit. The present invention can be directly used on any commercial vehicle body controller, has strong portability, reusability and reference value, and improves product development speed and work efficiency. The present invention has undergone sufficient experimental verification and mass production verification, ensuring design robustness and product quality, while reducing product development time and development costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 It is a circuit diagram of the left rearview mirror of the present invention. DETAILED DESCRIPTION

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without creative work are within the scope of protection of the present invention.

[0023] like Figure 1 As shown, a left and right rearview mirror drive circuit for a commercial vehicle includes full-bridge drive circuits for the left and right rearview mirrors. The full-bridge drive circuits are used to drive the motors of the left or right rearview mirror to rotate, thereby achieving up, down, left, and right adjustment. The full-bridge drive circuits include a first full-bridge drive circuit and a second full-bridge drive circuit. The first full-bridge drive circuit is connected to the left and right direction adjustment motor of the left or right rearview mirror and is used to drive the left and right direction adjustment motor to rotate forward or reverse, thereby achieving left or right adjustment of the rearview mirror. The second full-bridge drive circuit is connected to the up and down direction adjustment motor of the left or right rearview mirror and is used to drive the up and down direction adjustment motor to rotate forward or reverse, thereby achieving up or down adjustment of the rearview mirror.

[0024] The first full-bridge drive circuit comprises a first half-bridge circuit and a second half-bridge circuit, both of which are connected to the left / right adjustment motor. The second full-bridge drive circuit comprises a second half-bridge circuit and a third half-bridge circuit, both of which are connected to the up / down adjustment motor. The two half-bridge circuits shared by the four full-bridge drive circuits for the left and right mirrors can actually utilize dual-channel HSDs and LSDs, while the other four half-bridge circuits can also flexibly utilize multi-channel HSDs and LSDs.

[0025] The first half-bridge circuit outputs the L_Mirror_Left left adjustment signal for driving the left adjustment of the left and right direction adjustment motor, the second half-bridge circuit outputs the L_Mirror_Right / Up right upper adjustment signal for driving the right adjustment of the left and right direction adjustment motor and the up adjustment of the up and down direction adjustment motor, and the third half-bridge circuit outputs the L_Mirror_Down down adjustment signal for driving the down adjustment of the up and down direction adjustment motor.

[0026] The first, second, and third half-bridge circuits each include an intelligent high-side power driver (HSD), an intelligent low-side power driver (LSD), and an AD detection circuit. The HSD is connected to the AD detection circuit, and the two chips are all connected to the MCU. The outputs of the HSD and LSD are connected in parallel to the vertical or horizontal adjustment motors. The HSD switches power to the vertical or horizontal adjustment motors, while the LSD switches ground to the vertical or horizontal adjustment motors. The HSD and LSD are both controlled by the MCU, and their opening and closing are executed according to a specific logic sequence. The HSD has current detection and feedback capabilities. The IS pin of the HSD is fed into the MCU's AD detection IO port via an external AD detection circuit. The MCU's AD detection channel enables detection of the rearview mirror motor's operating current. When the motor stalls or the current increases abnormally, the MCU controller shuts down the HSD and LSD for overcurrent protection. In addition, the HSD and LSD themselves also have overcurrent and short-circuit self-protection capabilities. When the operating current of the rearview mirror motor is abnormal, hardware self-shutdown protection can be performed in time, giving this half-bridge drive circuit dual protection capabilities of software and hardware.

[0027] like Figure 1 The diagram shows the three half-bridges (i.e., two full-bridge drive circuits) for the left rearview mirror. The intelligent high-side power driver chip HSD1, the intelligent low-side power driver chip LSD1, and peripheral circuits form the first half-bridge circuit. The intelligent high-side power driver chip HSD2, the intelligent low-side power driver chip LSD2, and peripheral circuits form the second half-bridge circuit. The intelligent high-side power driver chip HSD3, the intelligent low-side power driver chip LSD3, and peripheral circuits form the third half-bridge circuit. These three half-bridge drive circuits form two full-bridge drive circuits. The first and second half-bridge circuits form a first full-bridge drive circuit to drive the left rearview mirror's left-right adjustment motor, while the second and third half-bridge circuits form a second full-bridge drive circuit to drive the left rearview mirror's up-down adjustment motor. Using the same circuit architecture, the right rearview mirror's two adjustment motors (left-right and up-down) can be driven, achieving three half-bridges (i.e., two full-bridge drive circuits) for the right rearview mirror. The six half-bridge circuits described above are combined to form four full-bridge drive circuits, enabling full-bridge drive of the four adjustment motors for the left and right mirrors. With the vigorous advancement and development of domestic automotive semiconductor chip production, HSD and LSD have also gradually become domestically produced. This has effectively controlled the cost of the left and right mirror drive circuits, improving their overall cost-performance.

[0028] The operating principles and circuit structures of the first, second, and third half-bridge circuits are identical. The first half-bridge circuit is used as an example to further analyze the HSD and LSD chips and their peripheral components. HSD1's IN enable pin is the chip enable pin, and HSD1's OUT port is a chip output pin. The IN enable pin is connected to the MCU's control IO port (network name: L_Mirror_Left_H_IN) through a current-limiting resistor R1. When L_Mirror_Left_H_IN is high, HSD1's OUT port is enabled; when L_Mirror_Left_H_IN is low, HSD1's OUT port is disabled. Pull-down resistor R3 provides a bias voltage for OUT port to ensure output stability, and filter capacitor C2 filters out high-frequency interference from OUT port. The HSD1's DEN pin is the chip's current diagnostic enable pin. The IS pin is the current sense feedback output pin. The DEN pin is connected to the MCU's control IO port (network name: L_Mirror_Left_H_DEN) through current-limiting resistor R2. The IS pin is connected to the MCU's AD sense IO port (network name: L_Mirror_Left_H_AD) through an AD detection circuit (composed of sampling resistor R5, current-limiting resistor R4, and filter capacitor C3). When L_Mirror_Left_H_DEN is high, the IS pin outputs a feedback signal. When L_Mirror_Left_H_DEN is low, the IS pin disables the output. The HSD1's VS pin is the chip's power supply pin. BAT is the power supply for the rearview mirror motor. BAT is filtered by capacitor C1 and connected to the VS power pin. The HSD1's GND pin is the chip's ground pin. The GND pin is connected to the system ground through current-limiting resistor R6 and reverse polarity protection diode D1.

[0029] LSD1's IN enable pin is the chip enable pin, and LSD1's OUT port is the chip output pin. The IN enable pin is connected to the MCU controller's control IO port (network name: L_Mirror_Left_L_IN) through current-limiting resistor R8. When L_Mirror_Left_L_IN is high, LSD1's OUT port is enabled. When L_Mirror_Left_L_IN is low, LSD1's OUT port is disabled. Filter capacitor C5 filters out high-frequency interference at the OUT port. The ENA pin of LSD1 is the chip fault diagnosis enable pin, and the FAULT pin of LSD1 is the fault feedback output pin. The ENA pin is connected to the MCU control IO port (network name L_Mirror_Left_L_EN) through current-limiting resistor R9. The FAULT pin is connected to one end of a pull-up resistor R7 and to the MCU controller's detection IO port (network name L_Mirror_Left_L_FT). The other end of pull-up resistor R7 is connected to the power supply VCC. When L_Mirror_Left_L_EN is high, the FAULT pin of LSD1 outputs a feedback signal. When L_Mirror_Left_L_EN is low, the FAULT pin of LSD1 disables the output. A low FAULT pin output indicates that LSD1 has entered an overcurrent or overtemperature fault state. The VCC port of LSD1 is the chip power pin, which is the system 5V power supply. The VCC system power supply is filtered by capacitor C4 and then connected to the LSD1 power pin. The GND port of LSD1 is the chip ground pin and is directly connected to the system ground.

[0030] The up and down direction adjustment motor or the left and right direction adjustment motor is an inductive load. In order to ensure smooth driving of the drive circuit, reduce temperature rise and extend service life, when one motor of the left rearview mirror or the right rearview mirror needs to work, the MCU controller first opens the LSD of the full-bridge drive circuit of the motor, and after a delay of 20ms, the MCU controller opens the HSD of the full-bridge drive circuit of the motor; when the motor needs to stop, the MCU controller first closes the HSD of the full-bridge drive circuit of the motor, and after a delay of 20ms, the MCU controller closes the LSD of the full-bridge drive circuit of the motor.

[0031] When the left or right rearview mirror is adjusted left and down simultaneously, the shared half-bridge in the two full-bridge drive circuits, i.e., LSD2 of the second half-bridge circuit, must be turned on and bear the drive current of the two motors; when the left or right rearview mirror is adjusted right and up simultaneously, the shared half-bridge in the two full-bridge drive circuits, i.e., HSD2 of the second half-bridge circuit, must be turned on and bear the drive current of the two motors; when selecting, the shared half-bridge, i.e., HSD2 and LSD2 of the second half-bridge circuit, must have a drive current capacity of more than twice the rated current of the motor.

[0032] When the left rearview mirror's left-to-right adjustment motor needs to be adjusted to the left, LSD2 of the second half-bridge circuit of the first full-bridge drive circuit driving the motor is first turned on, grounding its output. HSD1 of the first half-bridge circuit is then turned on, causing its output to be high, thereby achieving leftward adjustment. While the motor is operating, the AD detection circuit of HSD1 of the first half-bridge circuit and its IS pin provides feedback detection of the motor's operating current and transmits the converted voltage signal to the AD detection port of the MCU controller. HSD1's AD detection circuit consists of a sampling resistor R5, a current-limiting resistor R4, and a filter capacitor C3. The MCU controller's control IO port is connected to the IN enable terminals of HSD1 and LSD2 via current-limiting resistors R1 and R17, respectively. If the MCU controller detects an abnormal increase in motor current through the AD detection circuit, the MCU controller's control IO port outputs a low level, shutting down HSD1 and LSD2 for overcurrent or short-circuit protection. Conversely, if the left / right adjustment motor requires right adjustment, LSD1 of the first half-bridge circuit of the first full-bridge drive circuit is first turned on, followed by HSD2 of the second half-bridge circuit, thereby achieving right adjustment drive for the motor. While the motor is operating, HSD2 of the second half-bridge circuit and its IS port AD detection circuit provide feedback detection of the motor's operating current and transmit the converted voltage signal to the AD detection port of the MCU controller. The AD detection circuit consists of sampling resistor R14, current-limiting resistor R13, and filter capacitor C8. The MCU controller's control IO port is connected to the IN enable ports of HSD2 and LSD1 via current-limiting resistors R10 and R8, respectively. If the MCU controller detects an abnormal increase in motor current, the MCU controller's control IO port outputs a low level, shutting down HSD2 and LSD1 to provide overcurrent or short-circuit protection. The control methods for the left rearview mirror's up / down adjustment motor, the right rearview mirror's left / right adjustment motor, and the right rearview mirror's up / down adjustment motor are the same as those for the left rearview mirror's left / right adjustment motor. The HSD and LSD hardware also features overcurrent and short-circuit self-protection, enabling timely hardware self-shutdown protection when the mirror motor's operating current is abnormal. The aforementioned drive circuit and control method achieve functional performance, overcurrent and short-circuit protection, and software implementation for the left and right mirror drive circuits in commercial vehicles.

[0033] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A commercial vehicle left and right rearview mirror drive circuit, characterized in that: The invention comprises a full-bridge drive circuit for a left rearview mirror and a right rearview mirror, wherein the full-bridge drive circuit comprises a first full-bridge drive circuit and a second full-bridge drive circuit, wherein the first full-bridge drive circuit is connected to the left-right direction adjustment motor of the left rearview mirror or the right rearview mirror, and the second full-bridge drive circuit is connected to the up-down direction adjustment motor of the left rearview mirror or the right rearview mirror; the first full-bridge drive circuit comprises a first half-bridge circuit and a second half-bridge circuit, wherein the first half-bridge circuit and the second half-bridge circuit are both connected to the left-right direction adjustment motor; the second full-bridge drive circuit comprises a second half-bridge circuit and a third half-bridge circuit, wherein the second half-bridge circuit and the third half-bridge circuit are both connected to the up-down direction adjustment motor; the first half-bridge circuit, the second half-bridge circuit and the third half-bridge circuit are both connected to the up-down direction adjustment motor; the first half-bridge circuit, the second half-bridge circuit and the third half-bridge circuit are both connected to the up-down direction adjustment motor The bridge circuit and the third half-bridge circuit both include an intelligent high-side power driver chip, an intelligent low-side power driver chip and an AD detection circuit. The intelligent high-side power driver chip is connected to the AD detection circuit. The intelligent high-side power driver chip, the intelligent low-side power driver chip and the AD detection circuit are all connected to the MCU controller. The output ends of the intelligent high-side power driver chip and the intelligent low-side power driver chip are connected in parallel to the up-down direction adjustment motor or the left-right direction adjustment motor. The intelligent high-side power driver chip is used for power switching of the up-down direction adjustment motor or the left-right direction adjustment motor, and the intelligent low-side power driver chip is used for ground switching of the up-down direction adjustment motor or the left-right direction adjustment motor.

2. The commercial vehicle left and right rearview mirror drive circuit according to claim 1, characterized in that: The current detection feedback output pin of the intelligent high-side power driver chip is connected to the AD detection circuit, and the AD detection circuit is connected to the AD detection IO port of the MCU controller.

3. The commercial vehicle left and right rearview mirror drive circuit according to claim 2, characterized in that: The AD detection circuit includes a sampling resistor, a first current limiting resistor and a first filter capacitor. One end of the sampling resistor and the first current limiting resistor are both connected to the current detection feedback output pin of the intelligent high-side power driver chip, the other end of the first current limiting resistor is connected to the AD detection IO port of the MCU controller, the other end of the sampling resistor is connected in series with one end of the first filter capacitor, the other end of the first filter capacitor is connected to the other end of the first current limiting resistor, and the other end of the sampling resistor and one end of the first filter capacitor are both grounded.

4. The commercial vehicle left and right rearview mirror drive circuit according to claim 2 or 3, characterized in that: When one of the motors of the left or right rearview mirror needs to work, the MCU controller first turns on the intelligent low-side power driver chip of the full-bridge drive circuit that drives the motor. After a delay of 20ms, the MCU controller turns on the intelligent high-side power driver chip of the full-bridge drive circuit that drives the motor. When the motor needs to stop, the MCU controller first turns off the intelligent high-side power driver chip that drives the motor. After a delay of 20ms, the MCU controller turns off the intelligent high-side power driver chip that drives the motor.

5. The driving circuit for left and right rearview mirrors of a commercial vehicle according to claim 4, characterized in that: The IN enable terminals of the intelligent high-side power driver chip and the intelligent low-side power driver chip are both connected to the control IO port of the MCU controller through a current-limiting resistor; the current diagnosis enable terminal of the intelligent high-side power driver chip is connected to the control IO port of the MCU controller through a current-limiting resistor, and the fault diagnosis enable terminal of the intelligent low-side power driver chip is connected to the control IO port of the MCU controller through a current-limiting resistor; the fault feedback output terminal of the intelligent low-side power driver chip is respectively connected to the detection IO port of the MCU controller and one end of the first pull-up resistor, and the other end of the first pull-up resistor is connected to the power supply VCC; when the fault diagnosis enable terminal input is high level, the fault feedback output terminal outputs a feedback signal, and when the fault diagnosis enable terminal input is low level, the fault feedback output terminal turns off the output.

6. The commercial vehicle left and right rearview mirror drive circuit according to claim 5, characterized in that: The output end of the intelligent high-side power driver chip is connected to the up and down direction adjustment motor or the left and right direction adjustment motor through a protection circuit; the protection circuit includes a second pull-up resistor and a second filter capacitor, the second pull-up resistor and the second filter capacitor are connected in parallel, one end of the second pull-up resistor and the second filter capacitor are both connected to the output end of the intelligent high-side power driver chip, and the other ends of the second pull-up resistor and the second filter capacitor are both grounded; the output end of the intelligent low-side power driver chip is connected to one end of the third filter capacitor, and the other end of the third filter capacitor is grounded; the ground end of the intelligent high-side power driver chip is grounded through a second current limiting resistor and an anti-reverse connection diode, and the ground end of the intelligent low-side power driver chip is directly grounded; the power supply ends of the intelligent high-side power driver chip and the intelligent low-side power driver chip are both connected to the power supply through a filter capacitor.

7. The commercial vehicle left and right rearview mirror drive circuit according to claim 5 or 6, characterized in that: The first half-bridge circuit is used to drive the left adjustment of the left and right direction adjustment motor, the second half-bridge circuit is used to drive the right adjustment of the left and right direction adjustment motor and the up adjustment of the up and down direction adjustment motor, and the third half-bridge circuit is used for the down adjustment of the up and down direction adjustment motor; the driving current of the intelligent high-side power driver chip and the intelligent low-side power driver chip of the second half-bridge is more than twice the rated current of the up and down direction adjustment motor and the left and right direction adjustment motor.

8. The driving circuit for left and right rearview mirrors of a commercial vehicle according to claim 7, characterized in that: When the left adjustment and downward adjustment of the left rearview mirror or the right rearview mirror work simultaneously, the intelligent low-side power driver chip of the second half-bridge circuit shared by the first full-bridge drive circuit and the second full-bridge drive circuit is turned on and bears the driving current of the two motors; when the right adjustment and upward adjustment of the left rearview mirror or the right rearview mirror work simultaneously, the HSD of the second half-bridge circuit shared by the first full-bridge drive circuit and the second full-bridge drive circuit is turned on and bears the driving current of the two motors.

9. The driving circuit for left and right rearview mirrors of a commercial vehicle according to any one of claims 5, 6 and 8, characterized in that: The control method is as follows: when the left or right rearview mirror's left-side adjustment motor needs to be adjusted to the left, the MCU controller first turns on the intelligent low-side power driver chip of the second half-bridge circuit to ground its output, and then turns on the intelligent high-side power driver chip of the first half-bridge circuit to output a high level, thereby realizing left-side adjustment drive of the left or right adjustment motor; when the left or right rearview mirror's left-side adjustment motor needs to be adjusted to the right, the MCU controller first turns on the intelligent low-side power driver chip of the first half-bridge circuit to ground its output, and then turns on the intelligent high-side power driver chip of the second half-bridge circuit to output a high level, thereby realizing right-side adjustment drive of the left or right adjustment motor; When the up and down adjustment motor of the left rearview mirror or the right rearview mirror needs to be adjusted downward, the MCU controller first turns on the intelligent low-side power driver chip of the second half-bridge circuit to ground its output, and then turns on the intelligent high-side power driver chip of the third half-bridge circuit to output a high level, thereby realizing the downward adjustment drive of the left and right adjustment motors; when the up and down adjustment motor of the left rearview mirror or the right rearview mirror needs to be adjusted upward, the MCU controller first turns on the intelligent low-side power driver chip of the third half-bridge circuit to ground its output, and then turns on the intelligent high-side power driver chip of the second half-bridge circuit to output a high level, thereby realizing the upward adjustment drive of the up and down adjustment motors.

10. The commercial vehicle left and right rearview mirror driving circuit according to claim 9, characterized in that: When the AD detection circuit detects that the current of the up-down direction adjustment motor or the left-right direction adjustment motor increases abnormally, the control IO port of the MCU controller outputs a low level to shut down the working intelligent low-side power driver chip and the intelligent high-side power driver chip to achieve overcurrent or short-circuit protection; when the fault feedback output end of the intelligent low-side power driver chip outputs a low level, the control IO port of the MCU controller outputs a low level to shut down the working intelligent low-side power driver chip and the intelligent high-side power driver chip to achieve overcurrent or short-circuit protection.

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