Fault diagnosis method and device of multi-motor driving system, domain controller and vehicle

Abstract

The invention relates to the technical field of vehicles, in particular to a fault diagnosis method and device for a multi-motor driving system, a domain controller and a vehicle, and the method comprises the steps: determining a first target diagnosis strategy based on the motor fault level in fault information and a preset first corresponding relation if the fault information sent by a single motor module is received, the first corresponding relation is the corresponding relation between the motor fault level and the diagnosis strategy; if the fault information sent by the multiple motor modules is received, wheel end driving torques of multiple wheels of the vehicle are obtained, and the maximum value in the multiple wheel end driving torques is determined as the actual wheel end torque; determining a second target diagnosis strategy based on the actual wheel end torque, a motor fault level in the multiple pieces of fault information and a preset second corresponding relation; according to the method, diagnosis strategies can be given in a targeted manner in different fault scenes of the multi-motor driving system, and the fault diagnosis requirements of the multi-motor driving system are well met.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and in particular to a fault diagnosis method, device, domain controller, and vehicle for a multi-motor drive system. Background Technology

[0002] With the rapid development of new energy vehicle technology, multi-motor drive systems have become an important technological direction for high-end electric vehicles. Models with three, four, or even more motors are gradually being mass-produced and applied. These drive systems achieve torque vectoring distribution, efficient energy management, and improved dynamic performance through the coordinated work of multiple motors, significantly improving vehicle handling and stability.

[0003] However, as automotive technology evolves, traditional diagnostic strategies for drive systems based on single-motor or dual-motor architectures have revealed significant limitations and inadequacies. These strategies cannot cover the vast number of fault scenarios in vehicles with three-motor, four-motor, or even more-motor configurations, and are insufficient to meet the diagnostic needs of multi-motor drive systems. Summary of the Invention

[0004] This application provides a fault diagnosis method, device, domain controller, and vehicle for a multi-motor drive system, in order to solve the technical problem that the diagnostic strategies in related technologies cannot cover the massive fault scenarios of vehicles with three-motor, four-motor, or even more-motor configurations, and thus cannot meet the diagnostic needs of multi-motor drive systems.

[0005] This application provides a fault diagnosis method for a multi-motor drive system, wherein the multi-motor drive system includes multiple motor modules, and the method includes: If a fault information is received from a single motor module, a first target diagnostic strategy is determined based on the motor fault level in the fault information and a preset first correspondence relationship, wherein the first correspondence relationship is the correspondence between the motor fault level and the diagnostic strategy. If multiple fault messages from the motor modules are received, the wheel-end drive torques of multiple wheels of the vehicle are obtained, and the maximum value among the multiple wheel-end drive torques is determined as the actual wheel-end torque. Based on the actual wheel-end torque, the motor fault level in the multiple fault messages, and a preset second correspondence, a second target diagnostic strategy is determined. The second correspondence is the correspondence between multi-motor fault triggering conditions and diagnostic strategies. The triggering factors in the multi-motor fault triggering conditions include the actual wheel-end torque and the motor fault level. Both the first target diagnostic strategy and the second target diagnostic strategy are used for motor fault handling.

[0006] In one embodiment of this application, if fault information is received from a single motor module, determining a first target diagnostic strategy based on the motor fault level in the fault information and a preset first correspondence includes: In the case that the multi-motor drive system is a three-motor drive system, if a first fault information is received from the front motor module and the motor fault level in the first fault information is less than a preset level, then it is determined that the first target diagnostic strategy includes recording diagnostic fault codes. If the motor fault level in the first fault information is equal to the preset level, then the first maximum available speed of the front motor is periodically and continuously collected according to the preset data collection cycle; if multiple first maximum available speeds collected within a first preset time period are all greater than or equal to the first preset speed, then it is determined that the first target diagnostic strategy includes recording diagnostic fault codes.

[0007] In one embodiment of this application, the step of determining a first target diagnostic strategy based on the motor fault level in the fault information and a preset first correspondence relationship if fault information is received from a single motor module further includes: If the motor fault level in the first fault information is equal to the preset level, and within the first preset time period, multiple first maximum available speeds are all less than the first preset speed, then the first target diagnostic strategy is determined to include recording diagnostic fault codes, limiting vehicle speed based on the first maximum available speed, illuminating the motor fault light, and turning on the vehicle speed limit text reminder. If the motor fault level in the first fault information is greater than the preset level and continues for the first preset duration, then the first target diagnostic strategy is determined to include recording the diagnostic fault code, disabling the front motor drive, and illuminating the motor fault light.

[0008] In one embodiment of this application, if fault information is received from a single motor module, determining a first target diagnostic strategy based on the motor fault level in the fault information and a preset first correspondence includes: In the case that the multi-motor drive system is a three-motor drive system, if a second fault information is received from any of the rear motor modules and the motor fault level in the second fault information is less than a preset level, then the first target diagnostic strategy is determined to include recording diagnostic fault codes; and the motor in the rear motor module that sent the second fault information is determined to be the faulty rear motor. If the motor fault level in the second fault information is equal to the preset level, then the second maximum available speed of the motor after the fault is periodically and continuously collected according to the preset data collection cycle; if multiple second maximum available speeds collected within the second preset time period are all greater than or equal to the second preset speed, then it is determined that the first target diagnostic strategy includes recording diagnostic fault codes.

[0009] In one embodiment of this application, the step of determining a first target diagnostic strategy based on the motor fault level in the fault information and a preset first correspondence relationship if fault information is received from a single motor module further includes: If the motor fault level in the second fault information is equal to the preset level, and within the second preset time period, multiple second maximum available speeds are less than the second preset speed, then the first target diagnostic strategy is determined to include recording diagnostic fault codes, limiting vehicle speed based on the target available speed, illuminating the motor fault light, and opening the vehicle speed limit text reminder. The target available speed is the smaller value between the second maximum available speed and the third maximum available speed, and the third maximum available speed is another maximum available speed of the motor after it returns to normal. If the motor fault level in the second fault information is greater than the preset level and lasts for the second preset duration, then the first target diagnostic strategy is determined to include recording the diagnostic fault code, prohibiting the motor drive after the fault, limiting the vehicle speed based on the target available speed, illuminating the motor fault light, and turning on the vehicle speed limit text reminder.

[0010] In one embodiment of this application, determining the second target diagnostic strategy based on the actual wheel-end torque, the motor fault level among multiple fault information, and a preset second correspondence includes: If the motor fault level in multiple fault information is greater than or equal to the preset level, and the actual wheel end torque is within the preset wheel end torque threshold range and continues for a third preset duration, then the second target diagnostic strategy is determined to include recording diagnostic fault codes and illuminating the motor fault light. If the motor fault level in multiple fault messages is greater than or equal to a preset level, the target drive torque is less than a preset torque value, and this continues for the third preset duration, then the second target diagnostic strategy is determined to include recording diagnostic fault codes, illuminating the motor fault light, limiting the vehicle speed to a preset speed, limiting the vehicle acceleration to a preset acceleration, and activating a speed limit text reminder; the target drive torque is the sum of a first torque and a second torque; in the case of a three-motor drive system, the first torque is the maximum output drive torque of the front motor, and the second torque is the smaller of the maximum output drive torques of the two rear motors; in the case of a multi-motor drive system using three or more motors, the first torque is the minimum of the maximum output drive torques of two or more front motors, and the second torque is the minimum of the maximum output drive torques of two or more rear motors.

[0011] In one embodiment of this application, the step of determining the second target diagnostic strategy based on the actual wheel-end torque, the motor fault level among multiple fault information, and a preset second correspondence relationship further includes: If the motor fault level in multiple fault messages is greater than or equal to a preset level, the actual wheel-end torque is less than the minimum value in the wheel-end torque threshold range, and this continues for the third preset duration, then the second target diagnostic strategy is determined to include recording diagnostic fault codes, illuminating the motor fault light, and enabling a power interruption text reminder.

[0012] This application also provides a fault diagnosis device for a multi-motor drive system, the multi-motor drive system including multiple motor modules, the device comprising: The first fault diagnosis module is used to determine a first target diagnosis strategy based on the motor fault level in the fault information and a preset first correspondence relationship if it receives fault information sent by a single motor module. The first correspondence relationship is the correspondence between the motor fault level and the diagnosis strategy. The second fault diagnosis module is used to, if it receives fault information sent by multiple motor modules, acquire the wheel-end drive torque of multiple wheels of the vehicle, and determine the maximum value among the multiple wheel-end drive torques as the actual wheel-end torque; based on the actual wheel-end torque, the motor fault level in the multiple fault information, and a preset second correspondence, determine a second target diagnosis strategy, wherein the second correspondence is the correspondence between multi-motor fault triggering conditions and diagnosis strategies, and the triggering factors in the multi-motor fault triggering conditions include the actual wheel-end torque and the motor fault level; both the first target diagnosis strategy and the second target diagnosis strategy are used for motor fault handling.

[0013] This application also provides a domain controller, including a fault diagnosis device for a multi-motor drive system as described above.

[0014] This application also provides a vehicle including the domain controller as described above.

[0015] The beneficial effects of this application are as follows: The fault diagnosis method, device, domain controller, and vehicle for a multi-motor drive system proposed in this application include multiple motor modules. The method includes: if fault information is received from a single motor module, determining a first target diagnosis strategy based on the motor fault level in the fault information and a preset first correspondence relationship, wherein the first correspondence relationship is the correspondence between the motor fault level and the diagnosis strategy; if fault information is received from multiple motor modules, acquiring the wheel-end drive torque of multiple wheels of the vehicle, and determining the maximum value among the multiple wheel-end drive torques as the actual wheel-end torque; determining a second target diagnosis strategy based on the actual wheel-end torque, the motor fault level in the multiple fault information, and a preset second correspondence relationship, wherein the second correspondence relationship is the correspondence between the multi-motor fault triggering condition and the diagnosis strategy, wherein the triggering factors in the multi-motor fault triggering condition include the actual wheel-end torque and the motor fault level; both the first target diagnosis strategy and the second target diagnosis strategy are used for motor fault handling. This method can provide targeted diagnosis strategies under different multi-motor drive system fault scenarios (such as a single motor fault in a multi-motor drive system, or a multi-motor fault in a multi-motor drive system), thus better meeting the fault diagnosis needs of multi-motor drive systems. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0017] In the attached diagram: Figure 1 This is a flowchart illustrating a fault diagnosis method for a multi-motor drive system provided in one embodiment of this application. Figure 2 This is a schematic diagram of a front motor fault in a three-motor drive system in a fault diagnosis method for a multi-motor drive system provided in one embodiment of this application. Figure 3 This is a schematic diagram of a fault in the left rear motor of a three-motor drive system in a fault diagnosis method for a multi-motor drive system provided in one embodiment of this application. Figure 4 This is a schematic diagram of a right rear motor fault in a three-motor drive system in a fault diagnosis method for a multi-motor drive system provided in one embodiment of this application. Figure 5 This is a schematic diagram of a single motor fault in a four-motor drive system in a fault diagnosis method for a multi-motor drive system provided in one embodiment of this application. Figure 6This is a schematic diagram of a multi-motor fault in a three-motor drive system in a fault diagnosis method for a multi-motor drive system provided in one embodiment of this application. Figure 7 This is a schematic diagram of a multi-motor fault in a four-motor drive system in a fault diagnosis method for a multi-motor drive system provided in one embodiment of this application. Figure 8 This is a schematic diagram of the structure of a fault diagnosis device for a multi-motor drive system provided in one embodiment of this application; Figure 9 This is a schematic diagram of the structure of an electronic device provided in one embodiment of this application. Detailed Implementation

[0018] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0019] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The drawings only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0020] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the present application. However, it will be apparent to those skilled in the art that embodiments of the present application may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the present application.

[0021] Please see Figure 1 , Figure 1 This is a flowchart illustrating a fault diagnosis method for a multi-motor drive system provided in an embodiment of this application. The multi-motor drive system includes multiple motor modules, such as... Figure 1 As shown, the method includes: S110: If a fault information sent by a single motor module is received, a first target diagnostic strategy is determined based on the motor fault level in the fault information and a preset first correspondence relationship, wherein the first correspondence relationship is the correspondence between the motor fault level and the diagnostic strategy.

[0022] In some examples of this embodiment, the motor module includes a motor and a fault level feedback unit, which is used to determine the motor fault level according to the motor state and feed it back to the fault diagnosis device of the multi-motor drive system (the device for running the fault diagnosis method of the multi-motor drive system).

[0023] In some examples of this embodiment, the first correspondence can be a preset correspondence. The higher the motor fault level, the more serious the fault, and the more stringent the corresponding diagnostic strategy. For example, if the motor fault level is low, a diagnostic strategy of recording Diagnostic Trouble Codes (DTCs) can be used; if the motor fault level is high, a diagnostic strategy such as disabling motor drive can be used.

[0024] Understandably, the above steps can better adapt to the application scenario of single-motor fault diagnosis in multi-motor drive systems, and achieve high flexibility in single-motor fault diagnosis of multi-motor drive systems.

[0025] S120: If multiple fault information messages are received from the motor modules, the wheel-end drive torque of multiple wheels of the vehicle is obtained, and the maximum value among the multiple wheel-end drive torques is determined as the actual wheel-end torque; based on the actual wheel-end torque, the motor fault level in the multiple fault information messages, and a preset second correspondence, a second target diagnostic strategy is determined, where the second correspondence is the correspondence between multi-motor fault triggering conditions and diagnostic strategies, and the triggering factors in the multi-motor fault triggering conditions include the actual wheel-end torque and the motor fault level; both the first target diagnostic strategy and the second target diagnostic strategy are used for motor fault handling.

[0026] In some examples of this embodiment, the actual wheel-end torque directly reflects the actual effect of the motor drive output. By combining the actual wheel-end torque and the motor fault level, it is possible to improve the accuracy of multi-motor fault diagnosis, that is, to match a second target diagnostic strategy with higher accuracy.

[0027] In some examples of this embodiment, the second correspondence can be set according to the actual situation, such as different diagnostic strategies corresponding to different multi-motor fault triggering conditions.

[0028] It is understandable that by adopting the above step S120, it is possible to better adapt to the multi-motor fault diagnosis application scenario of multi-motor drive system.

[0029] Figure 2 This is a schematic diagram illustrating a front motor fault in a three-motor drive system within a fault diagnosis method for a multi-motor drive system provided in one embodiment of this application. Please refer to [the diagram]. Figure 2 , Figure 2The red dot and green dot indicate the faulty motor. 210 represents the wheel, and 220 represents the steering wheel. The front motor is located on the front axle of the vehicle, and the rear motor is located on the rear axle. The diagnostic scheme for a faulty front motor in a three-motor drive system is explained below: In some embodiments, if fault information is received from a single motor module, determining a first target diagnostic strategy based on the motor fault level in the fault information and a preset first correspondence includes: S1101a: When the multi-motor drive system is a three-motor drive system, if a first fault information is received from the front motor module, and the motor fault level in the first fault information is less than a preset level, then it is determined that the first target diagnostic strategy includes recording diagnostic fault codes.

[0030] In some examples of this embodiment, the front motor module refers to a motor module containing a front motor, and the front motor refers to a motor used to drive the front wheels of the vehicle. The preset level can be set according to the actual situation, such as level 3.

[0031] In some examples of this embodiment, the diagnostic fault code can be generated by the fault level feedback unit in the motor module. When the fault level feedback unit detects a motor abnormality, it generates a standardized code as a diagnostic fault code and feeds this diagnostic fault code back to the fault diagnosis device of the multi-motor drive system. This diagnostic fault code is used to quickly indicate the scope and nature of the fault.

[0032] In some examples of this embodiment, when the multi-motor drive system is a three-motor drive system, if the first fault information sent by the front motor module is received, and the motor fault level in the first fault information is less than the preset level, the diagnostic fault code fed back by the fault level feedback unit is recorded for subsequent traceability.

[0033] S1102a: If the motor fault level in the first fault information is equal to the preset level, then the first maximum available speed of the front motor is periodically and continuously collected according to the preset data collection cycle; if multiple first maximum available speeds collected within a first preset time period are all greater than or equal to the first preset speed, then the first target diagnostic strategy is determined to include recording diagnostic fault codes.

[0034] In some examples of this embodiment, the data acquisition period can be set according to actual conditions, such as 10ms. The motor module, such as the front motor module, has an internal maximum available speed acquisition unit that obtains the maximum available speed of the motor based on the motor state, etc. Therefore, the fault diagnosis device for the multi-motor drive system can acquire the first maximum available speed from the front motor module.

[0035] In some examples of this embodiment, the first preset duration can be set according to actual conditions, such as 3 data acquisition cycles. The first preset rotational speed can be set according to actual conditions, such as 5500 rpm.

[0036] Understandably, step S1101a provides a corresponding first target diagnostic strategy for the fault situation where the motor fault level in the first fault information is less than the preset level. Step S1102a provides a corresponding first target diagnostic strategy for the fault situation where the motor fault level in the first fault information is equal to the preset level, and within a first preset time period, multiple first maximum usable speeds are all greater than or equal to the first preset speed. Since these two situations have minimal impact on the vehicle and usually do not affect the personal safety of occupants, the first target diagnostic strategy for both situations is to record the diagnostic fault code for subsequent problem querying and tracing.

[0037] In some embodiments, the step of determining a first target diagnostic strategy based on the motor fault level in the fault information and a preset first correspondence relationship if fault information is received from a single motor module further includes: S1103a: If the motor fault level in the first fault information is equal to the preset level, and within the first preset time period, multiple first maximum available speeds are all less than the first preset speed, then the first target diagnostic strategy is determined to include recording diagnostic fault codes, limiting vehicle speed based on the first maximum available speed, illuminating the motor fault light, and turning on the vehicle speed limit text reminder.

[0038] In some examples of this embodiment, for a fault situation where the motor fault level in the first fault information is equal to a preset level, and multiple first maximum available speeds collected within a first preset time period are all less than a first preset speed, this fault situation is usually a fuel pump motor failure, that is, the front motor cannot work normally, causing the fuel pump to fail to supply fuel, which may manifest as difficulty starting the engine, insufficient power, or acceleration sluggishness. If the vehicle speed is not limited, the front motor may suffer further damage due to overload. Therefore, for this fault situation, this embodiment adopts a first target diagnostic strategy of recording diagnostic fault codes, limiting vehicle speed based on the first maximum available speed, illuminating the motor fault light, and activating the vehicle speed limit text reminder. By limiting the vehicle speed, the motor load can be reduced, preventing the fault situation from worsening, while maintaining the vehicle's basic driving capability.

[0039] In some examples of this embodiment, the first maximum available speed has a corresponding vehicle speed. Based on the vehicle speed corresponding to the first maximum available speed, the vehicle speed is limited, that is, the vehicle speed is limited to within the vehicle speed corresponding to the first maximum available speed.

[0040] S1104a: If the motor fault level in the first fault information is greater than the preset level and continues for the first preset duration, then the first target diagnostic strategy is determined to include recording diagnostic fault codes, disabling front motor drive, and illuminating the motor fault light.

[0041] In some examples of this embodiment, a fault situation where the motor fault level in the first fault information is greater than a preset level and lasts for a first preset duration can be determined as a severe fault. If the front motor continues to output power, it may cause the front motor and its related components to fail rapidly, such as the front motor burning out and the transmission system gears breaking, which may lead to vehicle power loss and fire risks. Therefore, this embodiment adopts a first target diagnostic strategy for this type of fault situation, which involves recording diagnostic fault codes, disabling the front motor drive, and illuminating the motor fault light. By disabling the front motor drive (cutting off the front motor drive), the fault is prevented from escalating at its source, prioritizing the safety of the front motor and its related components, and avoiding further deterioration of the internal fault of the front motor.

[0042] Table 1 below provides an example of a diagnostic scheme for a front motor fault in a three-motor drive system: Table 1. Examples of diagnostic schemes for front motor faults in a three-motor drive system.

[0043] In Table 1, MCUF_faultlevel represents the motor fault level of the front motor in the three-motor drive system, and MCUF_FotSpdMaxLimit represents the first maximum available speed of the front motor in the three-motor drive system.

[0044] Figure 3 This is a schematic diagram illustrating a fault in the left rear motor of a three-motor drive system within a fault diagnosis method for a multi-motor drive system provided in one embodiment of this application. Figure 4 This is a schematic diagram illustrating a fault in the right rear motor of a three-motor drive system within a fault diagnosis method for a multi-motor drive system provided in one embodiment of this application. Please refer to... Figure 3 and Figure 4 , Figure 3 and Figure 4 Red dots indicate faulty motors, and green dots indicate normal motors. The following explains the fault diagnosis scheme for the rear single motor in a three-motor drive system: In some embodiments, if fault information is received from a single motor module, determining a first target diagnostic strategy based on the motor fault level in the fault information and a preset first correspondence includes: S1101b: When the multi-motor drive system is a three-motor drive system, if a second fault information is received from any of the rear motor modules, and the motor fault level in the second fault information is less than a preset level, then the first target diagnostic strategy is determined to include recording diagnostic fault codes; the motor in the rear motor module that sent the second fault information is determined to be the faulty rear motor.

[0045] In some examples of this embodiment, the preset level can be level 3, etc.

[0046] S1102b: If the motor fault level in the second fault information is equal to the preset level, then the second maximum available speed of the motor after the fault is periodically and continuously collected according to the preset data collection cycle; if multiple second maximum available speeds collected within the second preset time period are all greater than or equal to the second preset speed, then the first target diagnostic strategy is determined to include recording diagnostic fault codes.

[0047] In some examples of this embodiment, the second preset rotational speed can be 5500 rpm, etc. The second preset duration can be set according to actual conditions, such as 3 data acquisition cycles, etc.

[0048] Understandably, since the two fault conditions in S1101b and S1102b have little impact on the vehicle and the people inside the vehicle, this embodiment adopts the first target diagnostic strategy of recording diagnostic fault codes to facilitate subsequent query and tracing.

[0049] In some embodiments, the step of determining a first target diagnostic strategy based on the motor fault level in the fault information and a preset first correspondence relationship if fault information is received from a single motor module further includes: S1103b: If the motor fault level in the second fault information is equal to the preset level, and within the second preset time period, multiple second maximum available speeds are less than the second preset speed, then the first target diagnostic strategy is determined to include recording diagnostic fault codes, limiting vehicle speed based on the target available speed, illuminating the motor fault light, and opening the vehicle speed limit text reminder. The target available speed is the smaller value between the second maximum available speed and the third maximum available speed, and the third maximum available speed is the maximum available speed of the motor after it returns to normal.

[0050] In some examples of this embodiment, in the three-motor drive system, the front motor is an asynchronous motor, and the two rear motors are synchronous motors. The two rear motors need to be controlled in coordination to maintain power matching. Therefore, when the motor fault level in the second fault information is equal to the preset level, and within the second preset time period, multiple second maximum available speeds are less than the average second preset speed, this embodiment limits the vehicle speed according to the minimum value of the maximum available speeds of the two rear motors, thereby ensuring the coordination of the two rear motors.

[0051] S1104b: If the motor fault level in the second fault information is greater than the preset level and lasts for the second preset duration, then the first target diagnostic strategy is determined to include recording the diagnostic fault code, prohibiting the motor drive after the fault, limiting the vehicle speed based on the target available speed, illuminating the motor fault light, and turning on the vehicle speed limit text reminder.

[0052] In some examples of this embodiment, when the motor fault level in the second fault information is greater than the preset level and lasts for a second preset duration, only the motor drive after the fault can be prohibited, while the drive capability of other motors is retained, thereby ensuring the continuous driving of the vehicle.

[0053] In some examples of this embodiment, when one of the rear motors fails, the two rear motors may output inconsistent torque. To address this, vehicles with rear steering can adjust the wheel direction using rear steering to prevent the vehicle from veering off course. Vehicles without rear steering can use a fault indication system to guide the user to manually operate the steering wheel to correct the vehicle's position.

[0054] Understandably, compared to the solution of directly disabling both rear motors, this embodiment only prohibits the motor drive after a failure, thus preserving the availability of motor torque performance to the maximum extent, effectively improving user experience while ensuring driving safety.

[0055] Table 2 below provides an example of a diagnostic scheme for a fault in the left rear motor of a three-motor drive system: Table 2. Examples of diagnostic schemes for left rear motor faults in a three-motor drive system.

[0056] Among them, MCURL_faultlevel represents the motor fault level of the left rear motor, and MCURL_FotSpdMaxLimit represents the second maximum available speed.

[0057] Figure 5 This is a schematic diagram illustrating a single-motor fault in a four-motor drive system within a fault diagnosis method for a multi-motor drive system provided in one embodiment of this application. Please refer to [the diagram]. Figure 5 , Figure 5The diagram on the left shows a fault in the front single motor of a four-motor drive system. Figure 5 The diagram on the right illustrates a fault in the rear single motor of a four-motor drive system. For Figure 5 The two fault scenarios mentioned can also be addressed using the solutions in steps S1101b-S1104b to determine the diagnostic strategy.

[0058] The following explains the multi-motor fault diagnosis scheme in a multi-motor drive system: In some embodiments, determining the second target diagnostic strategy based on the actual wheel-end torque, the motor fault level among multiple fault information, and a preset second correspondence includes: S1201: If the motor fault level in multiple fault information is greater than or equal to the preset level, and the actual wheel end torque is within the preset wheel end torque threshold range and continues for a third preset duration, then the second target diagnostic strategy is determined to include recording the diagnostic fault code and illuminating the motor fault light.

[0059] In some examples of this embodiment, the minimum value of the wheel-end torque threshold range can be the dynamic creep wheel-end drive torque of the vehicle, such as 85 Nm (Newton-meters), corresponding to a vehicle speed of approximately 8 km / h. The maximum value of the wheel-end torque threshold range can be the vehicle's significant descent limit, such as 300 Nm, corresponding to a vehicle speed of 100 km / h. This dynamic creep wheel-end drive torque and significant descent limit can be obtained through vehicle testing or set based on experience.

[0060] In some examples of this embodiment, the third preset duration can be set according to the actual situation, such as 2 seconds.

[0061] In some examples of this embodiment, for a fault situation where the motor fault level in multiple fault messages is greater than or equal to a preset level, the actual wheel-end torque is within a preset wheel-end torque threshold range, and this condition persists for a third preset duration, this embodiment alerts the driver to a fault in the power system by illuminating the motor fault light. Simultaneously, it ensures the normal operation of the vehicle.

[0062] S1202: If the motor fault level in multiple fault information entries is greater than or equal to a preset level, the target drive torque is less than a preset torque value, and this condition persists for the third preset duration, then the second target diagnostic strategy is determined to include recording diagnostic fault codes, illuminating the motor fault light, limiting the vehicle speed to a preset speed, limiting the vehicle acceleration to a preset acceleration, and activating a speed limit text reminder. The target drive torque is the sum of a first torque and a second torque. In the case of a three-motor drive system, the first torque is the maximum output drive torque of the front motor, and the second torque is the smaller of the maximum output drive torques of the two rear motors. In the case of a multi-motor drive system using three or more motors, the first torque is the minimum of the maximum output drive torques of two or more front motors, and the second torque is the minimum of the maximum output drive torques of two or more rear motors. The preset torque value is less than the minimum value of the wheel-end torque threshold range.

[0063] In some examples of this embodiment, the preset torque value can be set according to actual conditions, such as 5 Nm. The preset vehicle speed can be set according to actual needs, such as 30 km / h. The preset acceleration can be set according to actual conditions, such as 1 m / s². 2 (meters per second squared) etc.

[0064] In some examples of this embodiment, for a fault situation where the motor fault level in multiple fault messages is greater than or equal to a preset level, the target drive torque is less than a preset torque value, and this condition persists for a third preset duration, the total drive torque of the vehicle is extremely low, approaching the "stall threshold," meaning it can only sustain the vehicle at a very low speed and cannot drive normally. To address this, this embodiment limits the vehicle speed to within a preset speed, preventing power loss due to high-speed driving at extremely low torque, and ensuring the vehicle can travel in "limp mode" to the nearest repair shop, avoiding a complete breakdown. Furthermore, by limiting the vehicle acceleration to within a preset acceleration, this embodiment effectively ensures smooth power changes.

[0065] In some embodiments, determining the second target diagnostic strategy based on the actual wheel-end torque, the motor fault level among multiple fault information, and a preset second correspondence further includes: S1203: If the motor fault level in multiple fault information is greater than or equal to the preset level, the actual wheel end torque is less than the minimum value in the wheel end torque threshold range, and this continues for the third preset duration, then the second target diagnostic strategy is determined to include recording diagnostic fault codes, illuminating the motor fault light, and opening a power interruption text reminder.

[0066] In some examples of this embodiment, if the motor fault level in all the fault information is greater than or equal to the preset level, the actual wheel end torque is less than the minimum value in the wheel end torque threshold range, and this continues for the third preset duration, then the second target diagnostic strategy is determined to include recording diagnostic fault codes, illuminating the motor fault light, and opening a power interruption text reminder.

[0067] In some examples of this embodiment, when the motor fault level in all fault information is greater than or equal to a preset level, it indicates that the drive system has been severely damaged. Furthermore, when the actual wheel-end torque is less than the minimum value within the wheel-end torque threshold range and persists for a third preset duration, the vehicle almost loses its driving capability and can only maintain a very weak creeping state. Therefore, this embodiment employs a second target diagnostic strategy to address this situation: recording diagnostic fault codes, illuminating the motor fault light, and enabling a power interruption text alert. Additionally, when this fault is triggered, it indicates that the fault in step S1202 has definitely been triggered; therefore, the limitations on vehicle speed and acceleration also apply at this time. By enabling the power interruption text alert, this embodiment allows the vehicle driver to more clearly understand the vehicle's status and take timely measures.

[0068] Figure 6 This is a schematic diagram illustrating a multi-motor fault in a three-motor drive system within a fault diagnosis method for a multi-motor drive system provided in one embodiment of this application. Figure 6 A red dot indicates a faulty motor, and a green dot indicates a normal motor. For example... Figure 6 As shown, a multi-motor fault in a three-motor drive system refers to a failure in two or three motors within the system. When a multi-motor fault occurs in a three-motor drive system, the diagnostic schemes described in steps S1201 to S1203 above can be used for fault diagnosis.

[0069] Table 3 below provides an example of a diagnostic scheme for multi-motor faults in a three-motor drive system: Table 3 Examples of multi-motor fault diagnosis schemes for three-motor drive systems

[0070] Where MCUF_MaxOutputDriveTq represents the maximum output drive torque of the front motor, min( ) indicates minimum value calculation, MCURR_MaxOutputDriveTq indicates the maximum output drive torque of the right rear motor, and MCURL_MaxOutputDriveTq indicates the maximum output drive torque of the left rear motor.

[0071] Compared to single-motor fault diagnosis which combines motor fault level and maximum usable speed, multi-motor fault diagnosis incorporates actual wheel-end torque as a triggering factor. Actual wheel-end torque is the driving torque ultimately transmitted from the motor to the wheels via the transmission system, comprehensively reflecting the coordinated control effect of multiple motors. Actual wheel-end torque is directly related to vehicle power performance, such as acceleration, hill climbing, and driving stability, allowing users to intuitively perceive whether there are abnormalities in the actual wheel-end torque (such as sudden power loss or acceleration jerking). By using actual wheel-end torque as the judgment criterion, the resulting diagnostic strategy is strongly aligned with the user's actual experience, while achieving multi-motor fault diagnosis with fewer judgment conditions.

[0072] Furthermore, compared to setting multiple judgment conditions for multi-motor fault diagnosis schemes (such as setting corresponding diagnosis strategies for each fault level of each motor, then for a dual-motor system with 6 fault levels, there are 36 possible strategy combinations; for a tri-motor system, there are 216 possible strategy combinations; and for a quad-motor system, there are as many as 1296 possible combinations, making the diagnosis process very complex, the system computational load large, and the overall fault diagnosis efficiency low), the multi-motor fault diagnosis scheme in the above embodiment can diagnose multi-motor faults with fewer judgment conditions, improving diagnosis efficiency while also ensuring good diagnostic accuracy.

[0073] Figure 7 This is a schematic diagram illustrating a multi-motor fault in a four-motor drive system within a fault diagnosis method for a multi-motor drive system provided in one embodiment of this application. Figure 7 The red dot indicates a faulty motor, and the green dot indicates a normal motor. For example... Figure 7 As shown, multi-motor faults in a four-motor drive system include various scenarios such as front dual-motor faults, front single and rear single diagonal motor faults, same-side motor faults, front dual and rear single motor faults, and faults in all four motors. For multi-motor fault diagnosis in a four-motor drive system, similar to the multi-motor fault diagnosis scheme for a three-motor drive system, the fault level and actual wheel-end torque can be used as the basis for judgment, and then a corresponding diagnostic strategy can be matched. In some examples of this embodiment, the dynamic creep wheel-end drive torque and the limit for significant drive drop can be calibrated based on the vehicle's operating conditions, thereby achieving targeted diagnosis of multi-motor faults in different four-motor drive systems.

[0074] The fault diagnosis method for multi-motor drive systems described in the above embodiments has modular adaptability, allowing for flexible matching with different multi-motor configurations, such as three-motor drive systems and four-motor drive systems. This method can improve both the response efficiency and accuracy of fault diagnosis, while also providing broad coverage.

[0075] Please refer to Figure 8This embodiment also provides a fault diagnosis device for a multi-motor drive system, the multi-motor drive system including multiple motor modules, the device comprising: The first fault diagnosis module 810 is used to determine a first target diagnosis strategy based on the motor fault level in the fault information and a preset first correspondence relationship if it receives fault information sent by a single motor module. The first correspondence relationship is the correspondence between the motor fault level and the diagnosis strategy. The second fault diagnosis module 820 is used to, if it receives fault information sent by multiple motor modules, acquire the wheel-end drive torque of multiple wheels of the vehicle, and determine the maximum value among the multiple wheel-end drive torques as the actual wheel-end torque; based on the actual wheel-end torque, the motor fault level in the multiple fault information, and a preset second correspondence, determine a second target diagnosis strategy, wherein the second correspondence is the correspondence between multi-motor fault triggering conditions and diagnosis strategies, and the triggering factors in the multi-motor fault triggering conditions include the actual wheel-end torque and the motor fault level; both the first target diagnosis strategy and the second target diagnosis strategy are used for motor fault handling.

[0076] This device can provide targeted diagnostic strategies for different fault scenarios in multi-motor drive systems, which effectively meets the fault diagnosis needs of multi-motor drive systems at a low cost.

[0077] It should be noted that the fault diagnosis method and fault diagnosis device for multi-motor drive systems provided in the above embodiments belong to the same concept. The specific operation methods of each module have been described in detail in the method embodiments and will not be repeated here. In practical applications, the fault diagnosis device for multi-motor drive systems provided in the above embodiments can allocate the above functions to different functional modules as needed, that is, divide the internal structure of the system into different functional modules to complete all or part of the functions described above. This is not a limitation here.

[0078] This embodiment also provides a domain controller, including the fault diagnosis device for the multi-motor drive system as described above. The domain controller in this embodiment achieves the technical effects of the fault diagnosis device for the multi-motor drive system described above, which will not be elaborated further here.

[0079] This embodiment also provides a vehicle, including the domain controller as described above. The vehicle in this embodiment can achieve the technical effects achieved by the fault diagnosis device for the multi-motor drive system in the above embodiments, which will not be elaborated further here.

[0080] Figure 9 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 9As shown, the electronic device may include: a processor 910, a communication interface 920, a memory 930, and a communication bus 940, wherein the processor 910, the communication interface 920, and the memory 930 communicate with each other through the communication bus 940. The processor 910 can call logic instructions in the memory 930 to execute a fault diagnosis method for a multi-motor drive system. This method includes: if fault information is received from a single motor module, determining a first target diagnosis strategy based on the motor fault level in the fault information and a preset first correspondence, where the first correspondence is the correspondence between the motor fault level and the diagnosis strategy; if fault information is received from multiple motor modules, acquiring the wheel-end drive torque of multiple wheels of the vehicle, and determining the maximum value among the multiple wheel-end drive torques as the actual wheel-end torque; determining a second target diagnosis strategy based on the actual wheel-end torque, the motor fault level in the multiple fault information, and a preset second correspondence, where the second correspondence is the correspondence between multi-motor fault triggering conditions and the diagnosis strategy, where the triggering factors in the multi-motor fault triggering conditions include the actual wheel-end torque and the motor fault level; both the first and second target diagnosis strategies are used for motor fault handling.

[0081] Furthermore, the logical instructions in the aforementioned memory 930 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0082] In another aspect, this application also provides a non-transitory computer-readable storage medium storing a computer program thereon. When executed by a processor, the computer program is implemented to perform the fault diagnosis method for a multi-motor drive system provided by the methods described above. The method includes: if fault information is received from a single motor module, determining a first target diagnosis strategy based on the motor fault level in the fault information and a preset first correspondence, wherein the first correspondence is the correspondence between the motor fault level and the diagnosis strategy; if fault information is received from multiple motor modules, acquiring the wheel-end drive torque of multiple wheels of the vehicle, and determining the maximum value among the multiple wheel-end drive torques as the actual wheel-end torque; determining a second target diagnosis strategy based on the actual wheel-end torque, the motor fault level in the multiple fault information, and a preset second correspondence, wherein the second correspondence is the correspondence between multi-motor fault triggering conditions and the diagnosis strategy, wherein the triggering factors in the multi-motor fault triggering conditions include the actual wheel-end torque and the motor fault level; both the first target diagnosis strategy and the second target diagnosis strategy are used for motor fault handling.

[0083] The device embodiments described above are merely illustrative. The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules; that is, they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0084] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0085] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this application should still be covered by the claims of this application.

Claims

1. A fault diagnosis method for a multi-motor drive system, characterized in that, The multi-motor drive system includes multiple motor modules, and the method includes: If a fault information is received from a single motor module, a first target diagnostic strategy is determined based on the motor fault level in the fault information and a preset first correspondence relationship, wherein the first correspondence relationship is the correspondence between the motor fault level and the diagnostic strategy. If multiple fault messages from the motor modules are received, the wheel-end drive torques of multiple wheels of the vehicle are obtained, and the maximum value among the multiple wheel-end drive torques is determined as the actual wheel-end torque. Based on the actual wheel-end torque, the motor fault level in the multiple fault messages, and a preset second correspondence, a second target diagnostic strategy is determined. The second correspondence is the correspondence between multi-motor fault triggering conditions and diagnostic strategies. The triggering factors in the multi-motor fault triggering conditions include the actual wheel-end torque and the motor fault level. Both the first target diagnostic strategy and the second target diagnostic strategy are used for motor fault handling.

2. The fault diagnosis method for a multi-motor drive system according to claim 1, characterized in that, If a fault information is received from a single motor module, a first target diagnostic strategy is determined based on the motor fault level in the fault information and a preset first correspondence, including: In the case that the multi-motor drive system is a three-motor drive system, if a first fault information is received from the front motor module and the motor fault level in the first fault information is less than a preset level, then it is determined that the first target diagnostic strategy includes recording diagnostic fault codes. If the motor fault level in the first fault information is equal to the preset level, then the first maximum available speed of the front motor is periodically and continuously collected according to the preset data collection cycle; if multiple first maximum available speeds collected within a first preset time period are all greater than or equal to the first preset speed, then it is determined that the first target diagnostic strategy includes recording diagnostic fault codes.

3. The fault diagnosis method for a multi-motor drive system according to claim 2, characterized in that, If a fault information is received from a single motor module, the first target diagnostic strategy is determined based on the motor fault level in the fault information and a preset first correspondence, further comprising: If the motor fault level in the first fault information is equal to the preset level, and within the first preset time period, multiple first maximum available speeds are all less than the first preset speed, then the first target diagnostic strategy is determined to include recording diagnostic fault codes, limiting vehicle speed based on the first maximum available speed, illuminating the motor fault light, and turning on the vehicle speed limit text reminder. If the motor fault level in the first fault information is greater than the preset level and continues for the first preset duration, then the first target diagnostic strategy is determined to include recording the diagnostic fault code, disabling the front motor drive, and illuminating the motor fault light.

4. The fault diagnosis method for a multi-motor drive system according to claim 1, characterized in that, If a fault information is received from a single motor module, a first target diagnostic strategy is determined based on the motor fault level in the fault information and a preset first correspondence, including: In the case that the multi-motor drive system is a three-motor drive system, if a second fault information is received from any of the rear motor modules and the motor fault level in the second fault information is less than a preset level, then the first target diagnostic strategy is determined to include recording diagnostic fault codes; and the motor in the rear motor module that sent the second fault information is determined to be the faulty rear motor. If the motor fault level in the second fault information is equal to the preset level, then the second maximum available speed of the motor after the fault is periodically and continuously collected according to the preset data collection cycle; if multiple second maximum available speeds collected within the second preset time period are all greater than or equal to the second preset speed, then it is determined that the first target diagnostic strategy includes recording diagnostic fault codes.

5. The fault diagnosis method for a multi-motor drive system according to claim 4, characterized in that, If a fault information is received from a single motor module, the first target diagnostic strategy is determined based on the motor fault level in the fault information and a preset first correspondence, further comprising: If the motor fault level in the second fault information is equal to the preset level, and within the second preset time period, multiple second maximum available speeds are less than the second preset speed, then the first target diagnostic strategy is determined to include recording diagnostic fault codes, limiting vehicle speed based on the target available speed, illuminating the motor fault light, and opening the vehicle speed limit text reminder. The target available speed is the smaller value between the second maximum available speed and the third maximum available speed, and the third maximum available speed is another maximum available speed of the motor after it returns to normal. If the motor fault level in the second fault information is greater than the preset level and lasts for the second preset duration, then the first target diagnostic strategy is determined to include recording the diagnostic fault code, prohibiting the motor drive after the fault, limiting the vehicle speed based on the target available speed, illuminating the motor fault light, and turning on the vehicle speed limit text reminder.

6. The fault diagnosis method for a multi-motor drive system according to claim 1, characterized in that, The second target diagnostic strategy, determined based on the actual wheel-end torque, the motor fault level from multiple fault information sources, and a preset second correspondence, includes: If the motor fault level in multiple fault information is greater than or equal to the preset level, and the actual wheel end torque is within the preset wheel end torque threshold range and continues for a third preset duration, then the second target diagnostic strategy is determined to include recording diagnostic fault codes and illuminating the motor fault light. If the motor fault level in multiple fault messages is greater than or equal to a preset level, the target drive torque is less than a preset torque value, and this continues for the third preset duration, then the second target diagnostic strategy is determined to include recording diagnostic fault codes, illuminating the motor fault light, limiting the vehicle speed to a preset speed, limiting the vehicle acceleration to a preset acceleration, and activating a speed limit text reminder; the target drive torque is the sum of a first torque and a second torque; in the case of a three-motor drive system, the first torque is the maximum output drive torque of the front motor, and the second torque is the smaller of the maximum output drive torques of the two rear motors; in the case of a multi-motor drive system using three or more motors, the first torque is the minimum of the maximum output drive torques of two or more front motors, and the second torque is the minimum of the maximum output drive torques of two or more rear motors.

7. The fault diagnosis method for a multi-motor drive system according to claim 6, characterized in that, The step of determining the second target diagnostic strategy based on the actual wheel-end torque, the motor fault level among multiple fault information, and the preset second correspondence relationship further includes: If the motor fault level in multiple fault messages is greater than or equal to a preset level, the actual wheel-end torque is less than the minimum value in the wheel-end torque threshold range, and this continues for the third preset duration, then the second target diagnostic strategy is determined to include recording diagnostic fault codes, illuminating the motor fault light, and enabling a power interruption text reminder.

8. A fault diagnosis device for a multi-motor drive system, characterized in that, The multi-motor drive system includes multiple motor modules, and the device includes: The first fault diagnosis module is used to determine a first target diagnosis strategy based on the motor fault level in the fault information and a preset first correspondence relationship if it receives fault information sent by a single motor module. The first correspondence relationship is the correspondence between the motor fault level and the diagnosis strategy. The second fault diagnosis module is used to, if it receives fault information sent by multiple motor modules, acquire the wheel-end drive torque of multiple wheels of the vehicle, and determine the maximum value among the multiple wheel-end drive torques as the actual wheel-end torque; based on the actual wheel-end torque, the motor fault level in the multiple fault information, and a preset second correspondence, determine a second target diagnosis strategy, wherein the second correspondence is the correspondence between multi-motor fault triggering conditions and diagnosis strategies, and the triggering factors in the multi-motor fault triggering conditions include the actual wheel-end torque and the motor fault level; both the first target diagnosis strategy and the second target diagnosis strategy are used for motor fault handling.

9. A domain controller, characterized in that, It includes the fault diagnosis device for the multi-motor drive system as described in claim 8.

10. A vehicle, characterized in that, Includes the domain controller as described in claim 9.

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