Motor braking control method and device, motor controller and vehicle

Abstract

The invention provides a motor braking control method and device, a motor controller and a vehicle. The motor braking control method comprises the following steps: judging whether the maximum braking torque of a motor is reduced or not under the condition that a braking system has a fault; if the maximum braking torque of the motor is not reduced, the motor is controlled to compensate the braking torque according to the fault type of the braking system. And if the maximum braking torque of the motor is reduced, the motor is controlled to limit the maximum speed of the vehicle. According to the motor braking control method and device, the motor controller and the vehicle, the safety and reliability of braking control can be improved.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and in particular to a motor braking control method, device, motor controller and vehicle. Background Art

[0002] With the popularization of new energy vehicles, society pays more and more attention to vehicle driving safety. The requirements of laws and regulations on vehicle driving safety are becoming more and more perfect and stricter, and higher requirements are put forward for the safety of vehicles during driving. Among them, the stability and reliability of vehicle braking performance have a very important impact on the driving safety of vehicles. The braking system contains complex electrical circuits, control chips and circuits, moving parts, hydraulic devices and complex control software. Whether it is the random failure of parts or the system failure caused by insufficient production design, it will lead to the decline of braking performance, and even the failure or loss of control of the braking system during driving, which will seriously endanger the driving safety and reliability.

[0003] Therefore, it is necessary to provide an improved motor braking control method, device, motor controller and vehicle to solve the above problems. Summary of the invention

[0004] The present application provides a motor braking control method, device, motor controller and vehicle for improving driving safety and reliability.

[0005] The present application discloses a motor braking control method, comprising: in the case of a fault in the braking system, determining whether the maximum braking torque of the motor decreases;

[0006] If the maximum braking torque of the motor does not decrease, the motor is controlled to compensate the braking torque according to the fault type of the braking system;

[0007] If the maximum braking torque of the motor decreases, the motor is controlled to limit the maximum speed of the vehicle.

[0008] Furthermore, the controlling motor limits the maximum speed of the vehicle, including:

[0009] A target braking distance of the vehicle is set, and the maximum vehicle speed is determined according to the maximum braking torque of the motor, wherein the maximum vehicle speed is proportional to the maximum braking torque of the motor.

[0010] Furthermore, the relationship between the target braking distance, the maximum braking torque of the motor and the maximum vehicle speed is as follows:

[0011] S=1 / 2*V 2 *M / (F / r);

[0012] Wherein, S represents the target braking distance, V represents the maximum vehicle speed, M represents the weight of the vehicle, F represents the maximum wheel-end braking torque of the motor, and r represents the tire radius of the vehicle.

[0013] Further, controlling the motor to compensate the braking torque according to the fault type of the braking system includes:

[0014] receiving a braking torque original request signal of the motor and a braking torque request signal of the brake;

[0015] calculating a total brake torque request of the brake system, the total torque request being equal to a sum of a brake torque raw request of the motor and a brake torque request of the brake;

[0016] Determining a fault type of the braking system;

[0017] The compensated braking torque of the motor is determined according to the fault type of the braking system, and the motor is controlled to output the compensated braking torque.

[0018] Furthermore, the fault types include insufficient braking force, brake performance degradation, and external torque command error.

[0019] Further, the step of determining that the fault type of the braking system is insufficient braking force includes:

[0020] Calculate the actual total braking torque based on vehicle information;

[0021] calculating the total brake torque deviation, the total brake torque deviation being equal to a difference between a total brake torque request of the brake system and the actual total brake torque;

[0022] If the total braking torque request of the braking system is greater than a first set threshold, and the total braking torque deviation is greater than a second set threshold, and the anti-skid trigger flag of the braking system is not set, it is determined that the fault type of the braking system is insufficient braking force.

[0023] Further, when the fault type of the braking system is insufficient braking force, determining the braking torque after the motor is compensated includes:

[0024] determining a brake torque compensation request of the motor according to the total brake torque deviation;

[0025] The compensated braking torque of the motor is calculated, and the compensated braking torque of the motor is equal to the sum of the original braking torque request of the motor and the braking torque compensation request.

[0026] Furthermore, the step of determining that the fault type of the braking system is brake performance degradation includes:

[0027] If it is detected that a fault flag related to the brake system is set, the actual braking torque of the brake is obtained, and a braking torque attenuation value of the brake is calculated, where the braking torque attenuation value of the brake is equal to the difference between the braking torque request of the brake and the actual braking torque of the brake;

[0028] If the braking torque attenuation value of the brake is greater than a third set threshold, it is determined that the fault type of the braking system is brake performance attenuation.

[0029] Furthermore, the fault signs related to the braking system include: a braking system fault sign, a braking system overheating sign, and a braking system performance degradation sign.

[0030] Further, when the fault type of the braking system is brake performance attenuation, determining the braking torque after the motor is compensated includes:

[0031] determining a brake torque compensation request of the motor according to a brake torque attenuation value of the brake;

[0032] The compensated braking torque of the motor is calculated, and the compensated braking torque of the motor is equal to the sum of the original braking torque request of the motor and the braking torque compensation request.

[0033] Further, the step of determining that the fault type of the brake system is an external torque command error includes:

[0034] Determine whether there is a driving braking requirement;

[0035] If the driving braking demand exists, calculating the redundant total braking torque according to the vehicle operation information;

[0036] If the absolute value of the difference between the total braking torque request of the braking system and the redundant total braking torque is greater than a fourth set threshold, determining that the fault type of the braking system is an external torque command error;

[0037] or,

[0038] If an error or communication failure occurs between the received original request signal of the braking torque of the motor and the received braking torque request signal of the brake, it is determined that the fault type of the braking system is an external torque command error.

[0039] Further, the determining whether there is a driving braking demand includes:

[0040] When the brake pedal state signal or the brake pedal position signal is available, if the brake pedal depressed flag or the brake pedal bottom depressed flag is set, or the movement distance of the brake pedal is greater than the set distance, it is determined that there is a driving braking demand;

[0041] In the case where the brake pedal state signal and the brake pedal position signal fail, if the accelerator pedal movement distance at the set vehicle speed is less than the set distance, it is determined that there is a driving braking demand.

[0042] Further, in the case where the fault type of the braking system is an external torque command error, a larger value between an original request for the braking torque of the motor and the redundant total braking torque is determined as the compensated braking torque of the motor;

[0043] Or, the redundant total braking torque is determined as the braking torque after compensation of the motor.

[0044] Furthermore, the method further comprises:

[0045] Identify wheel locking conditions based on wheel speed change rate and tire slip rate;

[0046] When it is detected that the wheel is in or about to be in a locked state, the braking torque output by the motor is reduced.

[0047] The present application also discloses a motor braking control device, comprising:

[0048] A judgment module, used to judge whether the maximum braking torque of the motor decreases when there is a fault in the braking system;

[0049] The control module is used to obtain the judgment result of the judgment module and control the output of the motor accordingly according to the judgment result, wherein:

[0050] If the maximum braking torque of the motor decreases, the motor is controlled to limit the maximum speed of the vehicle;

[0051] If the maximum braking torque of the motor does not decrease, the motor is controlled to compensate the braking torque according to the fault type of the braking system.

[0052] The present application also discloses a motor controller, comprising a memory and a processor;

[0053] The memory is used to store computer programs;

[0054] When the processor is used to execute the computer program, the motor braking control method as described above is implemented.

[0055] The present application also discloses a vehicle, comprising the motor controller as described above.

[0056] The motor braking control method, device, motor controller and vehicle of the present application are controlled according to the maximum braking torque of the motor when there is a fault in the braking system. If the maximum braking torque of the motor does not decrease, the motor is controlled to compensate for the braking torque to ensure that the vehicle can still maintain a high braking efficiency when the braking system fails, thereby improving the stability and safety of the vehicle. If the maximum braking torque of the motor decreases, the maximum vehicle speed is limited to reduce the risk of dangerous events caused by braking system failures.

[0057] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the specification and, together with the description, serve to explain the principles of the specification.

[0059] Figure 1 It is a flow chart of the motor braking control method of the present application.

[0060] Figure 2 It is a flow chart of step S200 of the motor braking control method of the present application.

[0061] Figure 3 It is a flow chart of the motor braking control method of the present application when the fault type of the braking system is insufficient braking force.

[0062] Figure 4 It is a flow chart of the motor braking control method of the present application when the fault type of the braking system is brake performance degradation.

[0063] Figure 5 It is a flow chart of the motor braking control method of the present application when the fault type of the braking system is an external torque command error.

[0064] Figure 6 It is a relationship curve diagram among the target braking distance, the maximum vehicle speed and the maximum braking torque of the motor in the motor braking control method of the present application.

[0065] Figure 7 It is a schematic diagram of the motor brake control device of the present application. DETAILED DESCRIPTION

[0066] Here, the technical solutions in the embodiments (or "implementations") of the present application will be described clearly and completely in conjunction with the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements.

[0067] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the attached claims.

[0068] Next, the embodiments of this specification are described in detail.

[0069] like Figure 1 As shown, the present application provides a motor braking control method, comprising the following steps:

[0070] Step S100: When there is a fault in the braking system, determine whether the maximum braking torque of the motor decreases.

[0071] The maximum braking torque of a motor is usually closely related to the electrical characteristics (such as voltage, current, speed, temperature, etc.) and mechanical characteristics (such as rotor inertia, magnetic field strength, etc.) of the motor. Through the motor control system, the maximum braking torque of the motor can be calculated based on the rated parameters of the motor (such as rated power, rated current, rated speed, etc.) and the working status (such as current voltage, current, speed, temperature, etc.). During the driving process of the vehicle, the maximum braking torque of the motor will be continuously corrected according to parameters such as the motor temperature and water flow.

[0072] Step S200: If the maximum braking torque of the motor does not decrease, the motor is controlled to compensate the braking torque according to the fault type of the braking system.

[0073] If the maximum braking torque of the motor does not decrease, it means that the motor is capable of providing sufficient compensatory braking torque in the event of a brake system failure so as not to affect the braking performance of the vehicle.

[0074] like Figure 2 As shown, further, step S200 includes the following steps:

[0075] Step S201 : receiving a braking torque original request signal of a motor and a braking torque request signal of a brake.

[0076] The raw request for the brake torque of the motor and the brake torque request of the brake are usually calculated according to the position of the accelerator pedal, the position of the brake pedal and the vehicle speed.

[0077] Step S202: Calculate the total braking torque request of the braking system.

[0078] The total torque request of the braking system is equal to the sum of the original braking torque request of the motor and the braking torque request of the brake. The total braking torque request of the braking system is the ideal braking torque of the vehicle under the current driving state.

[0079] Step S203: determine the fault type of the braking system.

[0080] The fault type of the brake system can be judged based on the original request signal of the motor's brake torque, the brake's brake torque request signal and other vehicle or motor information. In this application, the fault types include insufficient braking force, brake performance degradation, and external torque command error. Different fault types have different judgment conditions.

[0081] Step S204: determining the compensated braking torque of the motor according to the fault type of the braking system, and controlling the motor to output the compensated braking torque.

[0082] Specifically, Figure 3 As shown, in step S203, the step of determining that the fault type of the braking system is insufficient braking force includes:

[0083] Step S2131: Calculate the actual total braking torque according to the vehicle information.

[0084] The actual total braking torque of the braking system can be calculated based on the vehicle's speed, weight, and slope information.

[0085] Step S2132: Calculate the total braking torque deviation.

[0086] The total brake torque deviation of the brake system is equal to the difference between the total brake torque request and the actual total brake torque of the brake system.

[0087] Step S2133: If the total braking torque request of the braking system is greater than the first set threshold, and the total braking torque deviation is greater than the second set threshold, and the anti-skid trigger flag of the braking system is not set, determine that the fault type of the braking system is insufficient braking force.

[0088] The total braking torque request of the braking system is greater than the first set threshold, indicating that the braking system requires a higher braking force under the current circumstances. The total braking torque deviation is greater than the second set threshold, indicating that the total braking torque currently actually output by the braking system is too different from the total braking torque requested, indicating that the current braking system cannot provide sufficient braking effect. The anti-skid trigger flag of the braking system is not set, which means that the total braking torque deviation is not caused by vehicle slip.

[0089] Only when the above three conditions are met at the same time can it be determined that the fault type of the braking system is insufficient braking force.

[0090] When the fault type of the braking system is insufficient braking force, step S204 includes:

[0091] Step S2141: Determine the braking torque compensation request of the motor according to the total braking torque deviation.

[0092] In some cases, the brake torque compensation request of the motor is equal to the total brake torque deviation. In some cases, the brake torque compensation request of the motor is linearly related to the total brake torque deviation.

[0093] Step S2142, calculating the braking torque after motor compensation.

[0094] The motor-compensated braking torque is equal to the sum of the motor's original braking torque request and the braking torque compensation request. In this way, it can be ensured that the braking system can restore sufficient braking force through motor compensation when the braking force is insufficient, ensuring that the braking system can continue to brake effectively and ensure driving safety.

[0095] like Figure 4 As shown, in step S203, the step of determining whether the fault type of the braking system is brake performance degradation includes:

[0096] Step S2231: If it is detected that a fault flag related to the brake system is set, the actual braking torque of the brake is obtained, and the braking torque attenuation value of the brake is calculated.

[0097] Among them, the fault signs related to the braking system include: braking system fault sign, braking system overheating sign, and braking system performance degradation sign.

[0098] When the brake system identifies a fault that affects the performance of the brake system or causes complete brake failure, such as actuator jamming, pipeline leakage, or missing friction pads, the brake system fault flag is set. When the brake system identifies that the temperature of any brake disc and friction pad exceeds the threshold, the brake system overheat flag is set. When there is a brake system fault and the brake system is overheated, the brake force is attenuated or all brake force is lost. When the brake system identifies problems such as leakage in the brake system, insufficient or missing friction pad thickness, and cavitation in the brake system oil, the brake system performance attenuation fault is set and the brake force is attenuated.

[0099] The actual braking torque of the brake can be calculated or set based on the hydraulic pressure, friction coefficient and geometric characteristics of the brake.

[0100] The braking torque decay value of the brake is equal to the difference between the braking torque request of the brake and the actual braking torque of the brake. In the worst case, the actual braking torque of the brake is 0, that is, the brake loses all braking force, and the braking torque decay value of the brake is equal to the braking torque request of the brake.

[0101] Step S2232: If the braking torque attenuation value of the brake is greater than the third set threshold, determine that the fault type of the braking system is brake performance attenuation.

[0102] When the fault type of the braking system is brake performance degradation, step S204 includes:

[0103] Step S2241: Determine the braking torque compensation request of the motor according to the braking torque attenuation value of the brake.

[0104] In some cases, the braking torque attenuation value of the brake is equal to the braking torque compensation request of the motor. In some cases, the braking torque attenuation value of the brake is linearly related to the braking torque compensation request of the motor.

[0105] Step S2242, calculating the braking torque after motor compensation.

[0106] The motor-compensated braking torque is equal to the sum of the motor's original braking torque request and the braking torque compensation request. In this way, it can be ensured that the braking system can restore sufficient braking force through motor compensation when the braking force is insufficient, ensuring that the braking system can continue to brake effectively and ensure driving safety.

[0107] like Figure 5 As shown, in step S203, the step of determining that the fault type of the braking system is an external torque command error includes:

[0108] Step S2332: Determine whether there is a driving braking requirement.

[0109] Among them, judging whether there is a driving braking demand includes:

[0110] When the brake pedal state signal or the brake pedal position signal is available, if the brake pedal is stepped on, it is determined that there is a driving braking demand. Specifically, if the brake pedal stepping flag or the brake pedal stepping bottom flag is set, or the moving distance of the brake pedal is greater than the set distance, it is determined that the brake pedal is stepped on.

[0111] In the case where the brake pedal state signal and the brake pedal position signal fail, it is determined whether there is a driving braking demand according to the position of the accelerator pedal. Specifically, if the accelerator pedal movement distance is less than the set distance at a certain set vehicle speed, it is determined that there is a driving braking demand.

[0112] Step S2333: If there is a driving braking demand, calculate the redundant total braking torque according to the vehicle operation information.

[0113] At this time, the redundant total braking torque is calculated according to the vehicle speed or rotation speed, the brake pedal position or the brake pedal state signal or the accelerator pedal position.

[0114] S2334: If the absolute value of the difference between the total braking torque request of the braking system and the redundant total braking torque is greater than a fourth set threshold, determine that the fault type of the braking system is an external torque command error.

[0115] It is understandable that, ideally, the total braking torque of the braking system should be equal to the redundant total braking torque. If the braking system requests a relatively small total braking torque, but the calculated redundant total braking torque is large, it may be caused by an error in the external torque command. By setting the fourth set threshold, the fault tolerance in the process of judging the error of the external torque command can be improved to avoid misjudgment of faults when the difference is too small.

[0116] In addition, a certain delay time can be set before calculating the difference between the total braking torque request of the braking system and the redundant total braking torque. When the driver has a braking demand, the total braking torque request for the braking system is not issued immediately, but requires a certain amount of signal processing time such as filtering, so that the processed total braking torque request can maximize the driver's driving experience. The certain delay time set here is to adapt to the signal processing time, so that the total braking torque request value of the braking system obtained is more accurate and the driver's driving experience is improved.

[0117] Furthermore, before step S2332, the following steps are also included:

[0118] Step S2331, determine whether the motor speed is greater than the set speed threshold, or whether the vehicle speed is greater than the set speed threshold; if the motor speed is greater than the set speed threshold, or the vehicle speed is greater than the set speed threshold, execute step S2332.

[0119] If the motor speed is greater than the set speed threshold, or the vehicle speed is greater than the set speed threshold, the vehicle's current operating conditions have reached the stage where braking torque needs to be controlled, ensuring more precise control of the braking system under high load or high speed conditions.

[0120] In some cases, it is also possible to determine whether the fault type is an external torque command error based on the state of the communication signal of the brake system. In this case, step S203 also includes:

[0121] Step S2335: If an error or communication failure occurs between the received original request signal of the motor's braking torque and the brake's braking torque request signal, it is determined that the fault type of the braking system is an external torque command error.

[0122] When the fault type of the braking system is an external torque command error, step S204 includes:

[0123] Step S234: Determine the larger value of the original request for the motor's braking torque and the redundant total braking torque as the motor's compensated braking torque. Or, determine the redundant total braking torque as the motor's compensated braking torque.

[0124] By selecting the larger value between the original request for the motor's braking torque and the redundant total braking torque, the braking system can ensure that there will be no safety issues caused by underestimating the braking force, thereby improving the fault tolerance and stability of the overall system. By using the calculated redundant total braking torque as the motor-compensated braking torque, the driving experience can be improved.

[0125] Step S300: If the maximum braking torque of the motor decreases, the motor is controlled to limit the maximum speed of the vehicle.

[0126] If the maximum braking torque of the motor decreases, it means that the motor cannot provide additional compensatory braking torque or the compensatory braking torque provided is insufficient.

[0127] In this application, the target braking distance of the vehicle can be set, and the maximum vehicle speed can be determined based on the correspondence between the maximum braking torque of the motor and the target braking distance. The maximum vehicle speed is proportional to the maximum braking torque of the motor. This means that when the motor can provide greater braking torque, the vehicle can travel at a higher speed and still stop within the specified target braking distance. However, when the braking torque of the motor decreases, the system will dynamically adjust the maximum vehicle speed based on this change to ensure that the vehicle can still stop safely within the target distance.

[0128] Specifically, the relationship between the target braking distance, the maximum braking torque of the motor and the maximum vehicle speed is as follows:

[0129] S=1 / 2*V 2 *M / (F / r).

[0130] Among them, S represents the target braking distance, V represents the maximum vehicle speed, M represents the weight of the vehicle, F represents the maximum braking torque of the motor wheel end, and r represents the tire radius of the vehicle.

[0131] Figure 6 It is the relationship curve between the target braking distance, the maximum vehicle speed and the maximum braking torque of the motor. Among them, the horizontal axis represents the braking force (ie F / r), the vertical axis represents the maximum vehicle speed (ie V), and the curve in the figure represents the contour line of the target braking distance, and the target braking distance increases from bottom to top. It can be seen that when the target braking distance is set to a certain small fixed value (ie curve A in the figure), the maximum vehicle speed will increase with the increase of braking force. As the set target braking distance increases (ie other curves above curve A), the maximum vehicle speed will also be improved.

[0132] Figure 6The dotted line B in the figure is an ideal curve, which sets additional target braking distances at different maximum vehicle speeds. By setting the dotted line B, the vehicle can have a sufficiently short braking distance at low speeds, thereby improving driving safety.

[0133] Furthermore, the motor braking control method of the present application also includes the following steps:

[0134] Step S401, identifying the wheel locking condition according to the wheel speed change rate and the tire slip rate;

[0135] Step S402: When it is identified that the wheel is in or about to be in a locked state, the braking torque output by the motor is reduced.

[0136] By reducing the braking torque output by the motor, the excessive braking force on the wheel can be reduced, allowing the wheel to return to normal rolling state, avoiding locking and ensuring that the vehicle remains stable and controllable during braking. Through this intelligent adjustment mechanism, the motor brake system can provide more efficient and safer braking performance under different road conditions and driving conditions.

[0137] like Figure 7 As shown, the present application also provides a motor braking control device, comprising:

[0138] The judgment module is used to judge whether the maximum braking torque of the motor decreases when there is a fault in the braking system.

[0139] The control module is used to obtain the judgment result of the judgment module and control the output of the motor accordingly according to the judgment result, wherein:

[0140] If the maximum braking torque of the motor decreases, the motor is controlled to limit the maximum speed of the vehicle.

[0141] If the maximum braking torque of the motor does not decrease, the motor is controlled to compensate the braking torque according to the fault type of the braking system.

[0142] The present application also provides a motor controller, comprising a memory and a processor. The memory is used to store a computer program. When the processor is used to execute the computer program, the motor braking control method as described above is implemented.

[0143] The present application also provides a vehicle, comprising the motor controller as described above.

[0144] The motor braking control method, device, motor controller and vehicle of the present application are controlled according to the maximum braking torque of the motor when there is a fault in the braking system. If the maximum braking torque of the motor does not decrease, the motor is controlled to compensate for the braking torque to ensure that the vehicle can still maintain a high braking efficiency when the braking system fails, thereby improving the stability and safety of the vehicle. If the maximum braking torque of the motor decreases, the maximum vehicle speed is limited to reduce the risk of dangerous events caused by braking system failures.

[0145] It should be noted that the technical solutions or technical features described in the above embodiments can be combined or supplemented with each other without causing conflicts. The scope of protection of this application is not limited to the precise structures described in the above embodiments and shown in the drawings; all modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this application should be included in the scope of protection of this application.

Claims

1. A motor braking control method, characterized in that: include: In case of a fault in the braking system, determine whether the maximum braking torque of the motor decreases; If the maximum braking torque of the motor does not decrease, the motor is controlled to compensate the braking torque according to the fault type of the braking system; If the maximum braking torque of the motor decreases, the motor is controlled to limit the maximum speed of the vehicle.

2. The motor braking control method according to claim 1, characterized in that: The controlling motor limits the maximum speed of the vehicle, including: A target braking distance of the vehicle is set, and the maximum vehicle speed is determined according to the maximum braking torque of the motor, wherein the maximum vehicle speed is proportional to the maximum braking torque of the motor.

3. The motor braking control method according to claim 2, characterized in that: The relationship between the target braking distance, the maximum braking torque of the motor and the maximum vehicle speed is as follows: S=1 / 2*V 2 *M / (F / r); Wherein, S represents the target braking distance, V represents the maximum vehicle speed, M represents the weight of the vehicle, F represents the maximum wheel-end braking torque of the motor, and r represents the tire radius of the vehicle.

4. The motor braking control method according to claim 1, characterized in that: The controlling the motor to compensate the braking torque according to the fault type of the braking system comprises: receiving a braking torque original request signal of the motor and a braking torque request signal of the brake; calculating a total brake torque request of the brake system, the total torque request being equal to a sum of a brake torque raw request of the motor and a brake torque request of the brake; Determining a fault type of the braking system; The compensated braking torque of the motor is determined according to the fault type of the braking system, and the motor is controlled to output the compensated braking torque.

5. The motor braking control method according to claim 4, characterized in that: The fault types include insufficient braking force, brake performance degradation, and external torque command error.

6. The motor braking control method according to claim 5, characterized in that: The step of determining that the fault type of the braking system is insufficient braking force comprises: Calculate the actual total braking torque based on vehicle information; calculating the total brake torque deviation, the total brake torque deviation being equal to a difference between a total brake torque request of the brake system and the actual total brake torque; If the total braking torque request of the braking system is greater than a first set threshold, and the total braking torque deviation is greater than a second set threshold, and the anti-skid trigger flag of the braking system is not set, it is determined that the fault type of the braking system is insufficient braking force.

7. The motor braking control method according to claim 6, characterized in that: When the fault type of the braking system is insufficient braking force, determining the braking torque after the motor is compensated includes: determining a brake torque compensation request of the motor according to the total brake torque deviation; The compensated braking torque of the motor is calculated, and the compensated braking torque of the motor is equal to the sum of the original braking torque request of the motor and the braking torque compensation request.

8. The motor brake control method according to claim 5, characterized in that: The step of determining that the fault type of the braking system is brake performance degradation comprises: If it is detected that a fault flag related to the brake system is set, the actual braking torque of the brake is obtained, and a braking torque attenuation value of the brake is calculated, where the braking torque attenuation value of the brake is equal to the difference between the braking torque request of the brake and the actual braking torque of the brake; If the braking torque attenuation value of the brake is greater than a third set threshold, it is determined that the fault type of the braking system is brake performance attenuation.

9. The motor brake control method according to claim 8, characterized in that: The fault signs related to the braking system include: a braking system fault sign, a braking system overheating sign, and a braking system performance degradation sign.

10. The motor brake control method according to claim 8, characterized in that: In a case where the fault type of the braking system is brake performance attenuation, determining the braking torque after the motor is compensated includes: determining a brake torque compensation request of the motor according to a brake torque attenuation value of the brake; The compensated braking torque of the motor is calculated, and the compensated braking torque of the motor is equal to the sum of the original braking torque request of the motor and the braking torque compensation request.

11. The motor brake control method according to claim 5, characterized in that: The step of determining that the fault type of the brake system is an external torque command error comprises: Determine whether there is a driving braking requirement; If the driving braking demand exists, calculating the redundant total braking torque according to the vehicle operation information; If the absolute value of the difference between the total braking torque request of the braking system and the redundant total braking torque is greater than a fourth set threshold, determining that the fault type of the braking system is an external torque command error; or, If an error or communication failure occurs between the received original request signal of the braking torque of the motor and the received braking torque request signal of the brake, it is determined that the fault type of the braking system is an external torque command error.

12. The motor brake control method according to claim 11, characterized in that: The determining whether there is a driving braking demand includes: When the brake pedal state signal or the brake pedal position signal is available, if the brake pedal depressed flag or the brake pedal bottom depressed flag is set, or the movement distance of the brake pedal is greater than the set distance, it is determined that there is a driving braking demand; In the case where the brake pedal state signal and the brake pedal position signal fail, if the accelerator pedal movement distance at the set vehicle speed is less than the set distance, it is determined that there is a driving braking demand.

13. The motor brake control method according to claim 11, characterized in that: In a case where the fault type of the braking system is an external torque command error, determining a larger value between an original request for the braking torque of the motor and the redundant total braking torque as the compensated braking torque of the motor; Or, the redundant total braking torque is determined as the braking torque after compensation of the motor.

14. The motor brake control method according to claim 1, characterized in that: The method further comprises: Identify wheel locking conditions based on wheel speed change rate and tire slip rate; When it is detected that the wheel is in or about to be in a locked state, the braking torque output by the motor is reduced.

15. A motor brake control device, characterized in that: include: A judgment module, used to judge whether the maximum braking torque of the motor decreases when there is a fault in the braking system; The control module is used to obtain the judgment result of the judgment module and control the output of the motor accordingly according to the judgment result, wherein: If the maximum braking torque of the motor decreases, the motor is controlled to limit the maximum speed of the vehicle; If the maximum braking torque of the motor does not decrease, the motor is controlled to compensate the braking torque according to the fault type of the braking system.

16. A motor controller, characterized in that: including memory and processor; The memory is used to store computer programs; When the processor is used to execute the computer program, the motor braking control method according to any one of claims 1 to 14 is implemented.

17. A vehicle, characterized in that: Comprising a motor controller as claimed in claim 16.

Images