Main drive hardware of low-speed unmanned chassis of high-voltage system

Abstract

The utility model discloses low-speed unmanned chassis main drive hardware of a high-voltage system in the technical field of chassis main drive. The low-speed unmanned chassis main drive hardware comprises a negative voltage generation circuit and a phase current overcurrent protection circuit which are connected. The phase current protection circuit comprises an MCU, an LDO, a driving chip, a U-phase driver, a V-phase driver, a W-phase driver, a switch tube SiC mosfet, a high-voltage input power supply, a motor, a sampling resistor and a signal amplifier. The first output end of the negative voltage generating circuit is connected with the first end of the LDO, the second output end of the negative voltage generating circuit is connected with the second input end of the driving chip, the second end of the LDO is connected with the first input end of the MCU, and the output end of the MCU is connected with the first input end of the driving chip. According to the utility model, the technical problems that the utilization rate is reduced, the bad piece rate is increased and the electric power is relatively small because the pin type insulated gate bipolar transistor adopted in the prior art is not suitable for a high-voltage platform can be solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of chassis main drive, and in particular relates to main drive hardware of a low-speed unmanned driving chassis with a high-voltage system. Background Art

[0002] A low-speed unmanned driving chassis refers to a vehicle that is powered by an onboard power supply, uses an electric motor to drive the wheels, and complies with all requirements of road traffic and safety regulations. It uses electricity from a rechargeable battery instead of gasoline for propulsion.

[0003] With the development of autonomous driving technology, it is becoming increasingly common to see products related to autonomous driving in our lives. Low-speed autonomous driving refers to autonomous driving vehicles with relatively simple and fixed application scenarios and speeds below 50 km / h. Common express delivery vehicles, food delivery vehicles, smart mobile charging piles, etc. are all based on low-speed autonomous driving chassis.

[0004] However, existing low-speed autonomous driving chassis are all low-voltage systems, which are incompatible with the electrical architecture of some high-voltage platforms. For example, mobile charging stations require high-voltage fast charging. The conventional pin-type insulated-gate bipolar transistors (IGBTs) used in existing technologies are not suitable for this application and are prone to failure due to overcurrent, resulting in reduced IGBT utilization, increased failure rates, and low electrical power. Furthermore, the low carrier frequency, typically 8K-10K, results in poor speed control accuracy, making chassis main drive hardware equipped with IGBTs difficult to meet practical application requirements. Therefore, a high-voltage system is needed for the main drive hardware of low-speed autonomous driving chassis to address these issues. Utility Model Content

[0005] The purpose of the utility model is to overcome the deficiencies in the prior art and provide a main drive hardware for a low-speed unmanned driving chassis of a high-voltage system, which can solve the technical problems that the ordinary power pin-type insulated-gate bipolar transistor (IGBT) used in the prior art is not suitable for high-voltage platforms, resulting in a decrease in the utilization rate of IGBT tubes, an increase in the failure rate, and low electrical power.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] The utility model provides a main drive hardware for a low-speed unmanned driving chassis of a high-voltage system, comprising a negative pressure generating circuit and a phase current overcurrent protection circuit connected;

[0008] The phase current overcurrent protection circuit includes an MCU, an LDO, a driver chip, a U-phase driver, a V-phase driver, a W-phase driver, a switching tube SiC MOSFET, a high-voltage input power supply, a motor, a sampling resistor and a signal amplifier;

[0009] The first output end of the negative voltage generating circuit is connected to the first end of the LDO, the second output end of the negative voltage generating circuit is connected to the second input end of the driver chip, the second end of the LDO is connected to the first input end of the MCU, the output end of the MCU is connected to the first input end of the driver chip, the first output end and the second output end of the driver chip are both connected to the first ends of the U-phase driver, the V-phase driver, and the W-phase driver, the second ends of the U-phase driver, the V-phase driver, and the W-phase driver are all connected to the gate of the switching tube SiC MOSFET, the source of the switching tube SiC MOSFET is connected to the first end of the motor, the second end of the motor is connected to the second input end of the MCU, the drain of the switching tube SiC MOSFET is connected to the first output end of the high-voltage input power supply, one end of the sampling resistor is connected to the source of the switching tube SiC MOSFET, and the other end is grounded, one end of the signal amplifier is connected to the third input end of the MCU, and the other end is connected to the connection point between the source of the switching tube SiC MOSFET and the sampling resistor.

[0010] Furthermore, the negative voltage generating circuit includes a flyback transformer, a second voltage regulator tube D2, a fourth voltage regulator tube D4, an eighth capacitor C8, a ninth capacitor C9, a tenth capacitor C10 and a third resistor R3;

[0011] The flyback transformer is connected to the positive electrode of the second voltage-stabilizing diode D2 and the first end of the eighth capacitor C8, and also serves as the ground terminal GND_Driver. The negative electrode of the second voltage-stabilizing diode D2 is respectively connected to the first end of the third resistor R3, the first end of the ninth capacitor C9, and the second end of the eighth capacitor C8, and also serves as the ground terminal GND_Power. The negative electrode of the fourth voltage-stabilizing diode D4 is respectively connected to the second end of the tenth capacitor C10, and also serves as the power supply terminal VCC. The positive electrode of the fourth voltage-stabilizing diode D4 is respectively connected to the second end of the third resistor R3, the second end of the ninth capacitor C9, and the first end of the tenth capacitor C10, and also serves as the power supply terminal VCC1.

[0012] Furthermore, a bootstrap drive circuit is arranged between the U-phase driver, V-phase driver and W-phase driver and the driver chip, and the bootstrap drive circuit includes an upper bridge and a lower bridge, the power supply end of the upper bridge is respectively connected to the ground end GND_Power and the power supply end VCC; the power supply end of the lower bridge is respectively connected to the ground end GND_Driver and the power supply end VCC1.

[0013] Furthermore, the upper bridge includes a first capacitor C1, a first resistor R1, a first rectifier diode D1, a second capacitor C2, a third capacitor C3, a second resistor R2, a third voltage regulator diode D3, a fourth resistor R4 and a seventh capacitor C7;

[0014] The two ends of the first capacitor C1 are respectively connected to the ground terminal GND_Power and the power supply terminal VCC; one end of the first resistor R1 is connected to the connection point between the first capacitor C1 and the power supply terminal VCC, and the other end is connected to the positive electrode of the first rectifier diode D1, the negative electrode of the first rectifier diode D1 is connected to the first input terminal of the driver chip, and the negative electrode of the first rectifier diode D1 is also connected to the second input terminal of the driver chip through the second capacitor C2; the first resistor R1, the first rectifier diode D1 and the second capacitor C2 constitute a bootstrap circuit; the high-level output terminal of the driver chip is connected to one end of the second resistor R2, and the other end of the second resistor R2 is used to be connected to the gate of the switching tube SiC MOSFET; the positive electrode of the third voltage regulator tube D3 is connected to the connection point between the second capacitor C2 and the second input terminal of the driver chip, and the negative electrode is used to be connected to the switching tube SiC The source of the mosfet is connected; the two ends of the third capacitor C3 are respectively connected to the negative electrode of the first rectifier diode D1 and the third voltage-stabilizing tube D3; one end of the seventh capacitor C7 is connected to the negative electrode of the third voltage-stabilizing tube D3, and the other end is connected to the positive electrode of the third voltage-stabilizing tube D3.

[0015] Furthermore, the upper bridge further includes a fourth resistor R4 , one end of which is connected to the connection point between the second resistor R2 and the third capacitor C3 , and the other end of which is connected to the negative electrode of the third voltage regulator tube D3 .

[0016] Furthermore, the lower bridge includes a fourth capacitor C4, a fifth capacitor C5, a sixth resistor R6 and a seventh resistor R7;

[0017] The third input terminal and the fourth input terminal of the driver chip are connected to the ground terminal GND_Driver and the power supply terminal VCC1 respectively; the two ends of the fourth capacitor C4 are connected to the ground terminal GND_Driver and the power supply terminal VCC1 respectively; the low-level output terminal of the driver chip is connected to one end of the sixth resistor R6, and the other end of the sixth resistor R6 is used to be connected to the gate of the switching tube SiC MOSFET;

[0018] One end of each of the seventh resistor R7 and the fifth capacitor C5 is used to be connected to the source of the switch tube SiC MOSFET, and the other end of each of the seventh resistor R7 and the fifth capacitor C5 is used to be connected to the gate of the switch tube SiC MOSFET.

[0019] Also included: an overcurrent comparator and an overcurrent fault latch;

[0020] One end of the overcurrent comparator is connected to the signal amplifier, and the other end is connected to the overcurrent fault latch. The output end of the overcurrent fault latch is connected to the fourth input end of the MCU.

[0021] Furthermore, it also includes a communication module that uses a bus communication method to build a network and an isolation communication module arranged between the communication module and the MCU to reduce the interference of high-voltage signals on low-voltage signals. The bus communication method supports one of LIN, CAN, and CANFD.

[0022] Furthermore, it also includes a temperature sampling unit for sampling the temperature inside the motor, and the temperature sampling unit includes a temperature sampling resistor arranged on the motor coil.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present application provides a complete circuit topology for the main drive hardware of a low-speed unmanned chassis of a high-voltage system. The electrical signal output by the low-voltage circuit flows into the gate of the switching tube SiC MOSFET through the driver chip, and the electrical signal output by the high-voltage power supply flows into the source and drain of the switching tube SiC MOSFET. When the gate-source voltage reaches the threshold, it is saturated and turned on, thereby driving the motor. The phase currents of the three phases UV and W generate a voltage drop through the sampling resistor. The small signal is filtered and amplified by the signal amplifier and transmitted to the MCU. The MCU then converts the read voltage into the phase current. If the phase current exceeds the software threshold at this time, an overcurrent protection interrupt is triggered. Since the SiC MOSFET itself uses SIC as the base material, it has better voltage resistance than traditional Si-based materials and can be used in high voltage and high power applications. At the same time, since it has the characteristics of MOSFET, the heat generated is mainly generated when it is turned on, and the heat loss generated by the switch is small. This determines that the SiC MOSFET is suitable for applications with higher switching frequencies. The switching frequency can reach above 30K, which improves the utilization rate of the SiC MOSFET and reduces the cost of SiC. The failure rate of MOSFETs is reduced, which improves the motor speed control accuracy and further ensures the normal use of the chassis main drive hardware to meet the needs of daily life;

[0025] To compensate for the frequency influence of software sampling, the voltage signal amplified by the signal amplifier is simultaneously transmitted to the overcurrent comparator. When overcurrent occurs, a digital signal is output to the overcurrent fault latch, which is finally read by the MCU as a hardware overcurrent fault. Compared with software overcurrent protection, hardware overcurrent protection only takes about 3us, which can effectively protect controller components. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1A schematic diagram of a phase current overcurrent protection circuit for a high-voltage system low-speed unmanned driving chassis main drive hardware provided in the first embodiment of the present application;

[0027] Figure 2 A schematic diagram of a negative pressure generating circuit principle for a low-speed unmanned driving chassis main drive hardware of a high-voltage system provided in Example 1 of the present application;

[0028] Figure 3 This is a schematic diagram of the principle of a bootstrap drive circuit for the main drive hardware of a low-speed unmanned driving chassis of a high-voltage system provided in Example 1 of the present application. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention and are not intended to limit the scope of protection of the present invention.

[0030] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. By this, features defined as "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0031] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0032] For ease of understanding, the names of the components appearing in this application are explained:

[0033] MCU: Microcontroller Unit (MCU), also known as Single-Chip Microcomputer or SCM, is a chip-level computer that reduces the frequency and specifications of the Central Processing Unit (CPU) and integrates memory, timers, USB, A / D converters, UART, PLC, DMA and other peripheral interfaces, and even LCD driver circuits on a single chip, forming a chip-level computer that can provide different control combinations for different applications.

[0034] SiC: silicon carbide; MOSFET, also known as MOSFET;

[0035] LDO is the abbreviation of "Low Dropout Regulator". It means low voltage dropout linear regulator in Chinese. It is a voltage regulator used in electronic devices. It is mainly used to convert the input voltage into a stable output voltage while maintaining a low voltage dropout.

[0036] VB: "Bulk Voltage" refers to the voltage connected to the semiconductor substrate or body in a semiconductor device, such as a MOSFET (metal-oxide-semiconductor field-effect transistor) or an IGBT (insulated gate bipolar transistor). The substrate is usually connected to the source.

[0037] VS: "Source Voltage" refers to the source voltage in the driver chip connected to an external load (such as a motor or LED). It is the voltage provided by the driver circuit to the load to drive the load to operate normally. Example 1:

[0038] like Figure 1 As shown, this embodiment provides a high-voltage system low-speed unmanned driving chassis main drive hardware, including a connected negative pressure generating circuit and a phase current overcurrent protection circuit;

[0039] The phase current overcurrent protection circuit includes an MCU, an LDO, a driver chip, a U-phase driver, a V-phase driver, a W-phase driver, a switching tube SiC MOSFET, a high-voltage input power supply, a motor, a sampling resistor and a signal amplifier;

[0040] The first output end of the negative voltage generating circuit is connected to the first end of the LDO, the second output end of the negative voltage generating circuit is connected to the second input end of the driver chip, the second end of the LDO is connected to the first input end of the MCU, the output end of the MCU is connected to the first input end of the driver chip, the first output end and the second output end of the driver chip are both connected to the first ends of the U-phase driver, the V-phase driver, and the W-phase driver, the second ends of the U-phase driver, the V-phase driver, and the W-phase driver are all connected to the gate of the switching tube SiC MOSFET, the source of the switching tube SiC MOSFET is connected to the first end of the motor, the second end of the motor is connected to the second input end of the MCU, the drain of the switching tube SiC MOSFET is connected to the first output end of the high-voltage input power supply, one end of the sampling resistor is connected to the source of the switching tube SiC MOSFET, and the other end is grounded, one end of the signal amplifier is connected to the third input end of the MCU, and the other end is connected to the connection point between the source of the switching tube SiC MOSFET and the sampling resistor.

[0041] The three-phase currents of UV and W generate a voltage drop through the sampling resistor. The small signal is filtered and amplified by the signal amplifier and transmitted to the MCU. The MCU then converts the read voltage into phase current. If the phase current exceeds the software threshold at this time, an overcurrent protection interrupt is triggered.

[0042] The negative voltage generating circuit includes a flyback transformer, a second voltage regulator tube D2, a fourth voltage regulator tube D4, an eighth capacitor C8, a ninth capacitor C9, a tenth capacitor C10 and a third resistor R3;

[0043] The flyback transformer is connected to the positive electrode of the second voltage-stabilizing diode D2 and the first end of the eighth capacitor C8, and also serves as the ground terminal GND_Driver. The negative electrode of the second voltage-stabilizing diode D2 is respectively connected to the first end of the third resistor R3, the first end of the ninth capacitor C9, and the second end of the eighth capacitor C8, and also serves as the ground terminal GND_Power. The negative electrode of the fourth voltage-stabilizing diode D4 is respectively connected to the second end of the tenth capacitor C10, and also serves as the power supply terminal VCC. The positive electrode of the fourth voltage-stabilizing diode D4 is respectively connected to the second end of the third resistor R3, the second end of the ninth capacitor C9, and the first end of the tenth capacitor C10, and also serves as the power supply terminal VCC1.

[0044] In this embodiment, the flyback voltage generator generates a 21V voltage. Zener diodes D2 and D4 with a stable voltage of 3V are selected. The reference ground is GND_Power, and the voltage at this point is 0. GND_Driver, serving as the ground for the upper bridge driver, is clamped to -3V by the Zener diode. When the lower bridge is turned off, the gate voltage is -3V. R3 acts as a current guide and a series circuit here. C8, C9, and C10 are used for filtering and energy storage.

[0045] A bootstrap drive circuit is arranged between the U-phase driver, V-phase driver, and W-phase driver and the driver chip. The bootstrap drive circuit includes an upper bridge and a lower bridge. The power supply end of the upper bridge is respectively connected to the ground end GND_Power and the power supply end VCC; the power supply end of the lower bridge is respectively connected to the ground end GND_Driver and the power supply end VCC1. Due to the limitations of the circuit topology, the upper bridge driver will be grounded to GND_Power only when the switching tube SiC MOSFET of the lower bridge is turned on. At this time, the driver chip voltage is clamped to -3V by the voltage regulator tube, and negative voltage shutdown can also be achieved during the upper bridge shutdown period.

[0046] The upper bridge includes a first capacitor C1, a first resistor R1, a first rectifier diode D1, a second capacitor C2, a third capacitor C3, a second resistor R2, a third voltage regulator diode D3, a fourth resistor R4 and a seventh capacitor C7;

[0047] The two ends of the first capacitor C1 are respectively connected to the ground terminal GND_Power and the power supply terminal VCC; one end of the first resistor R1 is connected to the connection point between the first capacitor C1 and the power supply terminal VCC, and the other end is connected to the positive electrode of the first rectifier diode D1, the negative electrode of the first rectifier diode D1 is connected to the first input terminal (VB) of the driver chip, and the negative electrode of the first rectifier diode D1 is also connected to the second input terminal (VS) of the driver chip through the second capacitor C2; the first resistor R1, the first rectifier diode D1 and the second capacitor C2 constitute a bootstrap circuit; the high-level output terminal (HO) of the driver chip is connected to one end of the second resistor R2, and the other end of the second resistor R2 is used to be connected to the gate of the switching tube SiC MOSFET; the positive electrode of the third voltage regulator tube D3 is connected to the connection point between the second capacitor C2 and the second input terminal of the driver chip, and the negative electrode is used to be connected to the switching tube SiC The source of the mosfet is connected; the two ends of the third capacitor C3 are respectively connected to the negative electrode of the first rectifier diode D1 and the third voltage-stabilizing tube D3; one end of the seventh capacitor C7 is connected to the negative electrode of the third voltage-stabilizing tube D3, and the other end is connected to the positive electrode of the third voltage-stabilizing tube D3.

[0048] The upper bridge further includes a fourth resistor R4 , one end of which is connected to the connection point between the second resistor R2 and the third capacitor C3 , and the other end of which is connected to the negative electrode of the third voltage regulator tube D3 .

[0049] The lower bridge includes a fourth capacitor C4, a fifth capacitor C5, a sixth resistor R6 and a seventh resistor R7;

[0050] The third input terminal and the fourth input terminal of the driver chip are connected to the ground terminal GND_Driver and the power supply terminal VCC1 respectively; the two ends of the fourth capacitor C4 are connected to the ground terminal GND_Driver and the power supply terminal VCC1 respectively; the low-level output terminal (LO) of the driver chip is connected to one end of the sixth resistor R6, and the other end of the sixth resistor R6 is used to be connected to the gate of the switching tube SiC MOSFET;

[0051] One end of each of the seventh resistor R7 and the fifth capacitor C5 is used to be connected to the source of the switch tube SiC MOSFET, and the other end of each of the seventh resistor R7 and the fifth capacitor C5 is used to be connected to the gate of the switch tube SiC MOSFET.

[0052] The bootstrap circuit is composed of a first resistor R1, a first voltage stabilizing diode D1 and a second capacitor C2.

[0053] When the circuit is initially connected, the capacitor is not charged or only partially charged. However, after the lower-side SiC MOSFET switches on, current flows through R1 and D1, charging C2 to a value that essentially reaches the supply voltage. This voltage is reduced by the forward voltage of D1, the voltage drop of R1, and the conduction voltage drop of the SiC MOSFET. If the lower-side SiC MOSFET switches off, C2 can provide the energy required by the upper-side driver stage, hence the name "bootstrap capacitor."

[0054] Also included: an overcurrent comparator and an overcurrent fault latch;

[0055] One end of the overcurrent comparator is connected to the signal amplifier, and the other end is connected to the overcurrent fault latch. The output end of the overcurrent fault latch is connected to the fourth input end of the MCU.

[0056] Furthermore, it also includes a communication module that uses a bus communication method to build a network and an isolation communication module arranged between the communication module and the MCU to reduce the interference of high-voltage signals on low-voltage signals. The bus communication method supports one of LIN, CAN, and CANFD.

[0057] Furthermore, it also includes a temperature sampling unit for sampling the temperature inside the motor, and the temperature sampling unit includes a temperature sampling resistor arranged on the motor coil.

[0058] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A high-voltage system low-speed unmanned driving chassis main drive hardware, characterized by: including a connected negative voltage generating circuit and a phase current overcurrent protection circuit; The phase current overcurrent protection circuit includes an MCU, an LDO, a driver chip, a U-phase driver, a V-phase driver, a W-phase driver, a switching tube SiC MOSFET, a high-voltage input power supply, a motor, a sampling resistor and a signal amplifier; The first output end of the negative voltage generating circuit is connected to the first end of the LDO, the second output end of the negative voltage generating circuit is connected to the second input end of the driver chip, the second end of the LDO is connected to the first input end of the MCU, the output end of the MCU is connected to the first input end of the driver chip, the first output end and the second output end of the driver chip are both connected to the first ends of the U-phase driver, the V-phase driver, and the W-phase driver, the second ends of the U-phase driver, the V-phase driver, and the W-phase driver are all connected to the gate of the switching tube SiC MOSFET, the source of the switching tube SiC MOSFET is connected to the first end of the motor, the second end of the motor is connected to the second input end of the MCU, the drain of the switching tube SiC MOSFET is connected to the first output end of the high-voltage input power supply, one end of the sampling resistor is connected to the source of the switching tube SiC MOSFET, and the other end is grounded, one end of the signal amplifier is connected to the third input end of the MCU, and the other end is connected to the connection point between the source of the switching tube SiC MOSFET and the sampling resistor.

2. The high-voltage system low-speed unmanned driving chassis main drive hardware according to claim 1, characterized in that: The negative voltage generating circuit includes a flyback transformer, a second voltage regulator tube D2, a fourth voltage regulator tube D4, an eighth capacitor C8, a ninth capacitor C9, a tenth capacitor C10 and a third resistor R3; The flyback transformer is connected to the positive electrode of the second voltage-stabilizing diode D2 and the first end of the eighth capacitor C8, and also serves as the ground terminal GND_Driver. The negative electrode of the second voltage-stabilizing diode D2 is respectively connected to the first end of the third resistor R3, the first end of the ninth capacitor C9, and the second end of the eighth capacitor C8, and also serves as the ground terminal GND_Power. The negative electrode of the fourth voltage-stabilizing diode D4 is respectively connected to the second end of the tenth capacitor C10, and also serves as the power supply terminal VCC. The positive electrode of the fourth voltage-stabilizing diode D4 is respectively connected to the second end of the third resistor R3, the second end of the ninth capacitor C9, and the first end of the tenth capacitor C10, and also serves as the power supply terminal VCC1.

3. The high-voltage system low-speed unmanned driving chassis main drive hardware according to claim 2, characterized in that: A bootstrap drive circuit is arranged between the U-phase driver, V-phase driver and W-phase driver and the driver chip. The bootstrap drive circuit includes an upper bridge and a lower bridge. The power supply end of the upper bridge is respectively connected to the ground end GND_Power and the power supply end VCC; the power supply end of the lower bridge is respectively connected to the ground end GND_Driver and the power supply end VCC1.

4. The high-voltage system low-speed unmanned driving chassis main drive hardware according to claim 3 is characterized by: The upper bridge includes a first capacitor C1, a first resistor R1, a first rectifier diode D1, a second capacitor C2, a third capacitor C3, a second resistor R2, a third voltage regulator diode D3, a fourth resistor R4 and a seventh capacitor C7; The two ends of the first capacitor C1 are respectively connected to the ground terminal GND_Power and the power supply terminal VCC; one end of the first resistor R1 is connected to the connection point between the first capacitor C1 and the power supply terminal VCC, and the other end is connected to the positive electrode of the first rectifier diode D1, the negative electrode of the first rectifier diode D1 is connected to the first input terminal of the driver chip, and the negative electrode of the first rectifier diode D1 is also connected to the second input terminal of the driver chip through the second capacitor C2; the first resistor R1, the first rectifier diode D1 and the second capacitor C2 constitute a bootstrap circuit; the high-level output terminal of the driver chip is connected to one end of the second resistor R2, and the other end of the second resistor R2 is used to be connected to the gate of the switching tube SiC MOSFET; the positive electrode of the third voltage regulator tube D3 is connected to the connection point between the second capacitor C2 and the second input terminal of the driver chip, and the negative electrode is used to be connected to the switching tube SiC The source of the mosfet is connected; the two ends of the third capacitor C3 are respectively connected to the negative electrode of the first rectifier diode D1 and the third voltage-stabilizing tube D3; one end of the seventh capacitor C7 is connected to the negative electrode of the third voltage-stabilizing tube D3, and the other end is connected to the positive electrode of the third voltage-stabilizing tube D3.

5. The high-voltage system low-speed unmanned driving chassis main drive hardware according to claim 4, characterized in that: The upper bridge further includes a fourth resistor R4 , one end of which is connected to the connection point between the second resistor R2 and the third capacitor C3 , and the other end of which is connected to the negative electrode of the third voltage regulator tube D3 .

6. The high-voltage system low-speed unmanned driving chassis main drive hardware according to claim 3, characterized in that: The lower bridge includes a fourth capacitor C4, a fifth capacitor C5, a sixth resistor R6 and a seventh resistor R7; The third input terminal and the fourth input terminal of the driver chip are connected to the ground terminal GND_Driver and the power supply terminal VCC1 respectively; the two ends of the fourth capacitor C4 are connected to the ground terminal GND_Driver and the power supply terminal VCC1 respectively; the low-level output terminal of the driver chip is connected to one end of the sixth resistor R6, and the other end of the sixth resistor R6 is used to be connected to the gate of the switching tube SiC MOSFET; One end of each of the seventh resistor R7 and the fifth capacitor C5 is used to be connected to the source of the switch tube SiC MOSFET, and the other end of each of the seventh resistor R7 and the fifth capacitor C5 is used to be connected to the gate of the switch tube SiC MOSFET.

7. The high-voltage system low-speed unmanned driving chassis main drive hardware according to claim 1 is characterized in that: Also includes: Overcurrent comparator and overcurrent fault latch; One end of the overcurrent comparator is connected to the signal amplifier, and the other end is connected to the overcurrent fault latch. The output end of the overcurrent fault latch is connected to the fourth input end of the MCU.

8. The high-voltage system low-speed unmanned driving chassis main drive hardware according to claim 1 is characterized in that: It also includes a communication module that uses a bus communication method to build a network and an isolation communication module arranged between the communication module and the MCU to reduce the interference of high-voltage signals on low-voltage signals. The bus communication method supports one of LIN, CAN, and CANFD.

9. The high-voltage system low-speed unmanned driving chassis main drive hardware according to claim 1 is characterized in that: The motor further comprises a temperature sampling unit for sampling the temperature inside the motor, wherein the temperature sampling unit comprises a temperature sampling resistor arranged on the motor coil.

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