A fault location method for an electric steering oil pump module of a pure electric commercial vehicle

Abstract

The present invention provides a fault location method for an electric steering oil pump module of a pure electric commercial vehicle, comprising the following steps: locating the oil pump motor overtemperature fault point according to the temperature control operation state and the resistance value of the steering oil pump temperature sensor; locating the output phase loss fault point according to the steering oil pump high-voltage interlocking state and the steering oil pump harness terminal resistance value; locating the input overvoltage fault point according to the power battery state, the power battery output voltage, and the steering oil pump input voltage value; locating the input undervoltage fault point according to the power battery state, the power battery output voltage, the steering oil pump input voltage value, and the all-in-one controller input voltage signal; locating the overcurrent fault point according to the steering system state, the steering oil pump output current value, and the steering oil pump configuration parameter rated current value; locating the motor overload fault point according to the steering system state, the steering wheel state, the steering angle state, the power battery output voltage, and the steering oil pump input voltage value. The present invention can effectively locate the specific fault position of the steering oil pump.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy vehicles, and in particular relates to a fault locating method for an electric steering oil pump module of a pure electric commercial vehicle. Background Art

[0002] Relying on electronic components such as sensors to provide judgment information, once the electronic components are damaged, the fault cannot be diagnosed. Existing patent application CN201910792569.9-A method and device for locating oil pump motor faults, based on the premise that the oil pump has no electrical faults, monitors the oil pump motor speed, current, and working status, and determines the motor blocking and idling faults according to the size of the values. Existing patent application CN202110581236.9-Control method for electronic oil pump fault diagnosis Electronic equipment and storage medium, verify whether the fault reported by the oil pump has occurred.

[0003] The above patent application has the same technical problems as the prior art, namely, there are few identifiable fault types, and the faults such as abnormal voltage, current, etc. of the steering oil pump itself can be diagnosed. There is a lack of diagnosis of specific failed components of the system's mechanical structure, and the fault location cannot be accurately located. Summary of the invention

[0004] The purpose of the present invention is to solve the deficiencies of the above-mentioned background technology and to provide a fault locating method for an electric steering oil pump module of a pure electric commercial vehicle, which can effectively locate the specific fault position of the steering oil pump.

[0005] The technical solution adopted by the present invention is: a fault location method for an electric steering oil pump module of a pure electric commercial vehicle, comprising the following steps:

[0006] The vehicle controller receives the fault code reported by the electric steering oil pump module;

[0007] If the fault code type received by the vehicle controller is an oil pump motor overtemperature fault, the fault point is located according to the temperature control operation status, the resistance value of the steering oil pump temperature sensor, and the fault status of the motor controller, which is the water pump, water circuit, cooling fan, or steering oil pump thermal resistor or temperature sensor harness or motor control or motor body;

[0008] If the fault code type received by the vehicle controller is an output phase loss fault, the fault point is located according to the high-voltage interlocking state of the steering oil pump, the resistance of the steering oil pump harness end, the phase-to-phase resistance, and the insulation resistance to ground. It is the steering oil pump external high-voltage harness or the steering oil pump internal harness or the three-phase motor phase-to-phase or the three-phase motor to ground or the steering oil pump module current detection module;

[0009] If the fault code type received by the vehicle controller is an input overvoltage fault, the fault point is located according to the power battery status, power battery output voltage, steering oil pump input voltage value, and all-in-one controller input voltage signal, which is the battery system or all-in-one controller, main relay or voltage sensor, or steering oil pump controller software version;

[0010] If the fault code type received by the vehicle controller is an input undervoltage fault, the fault point is located according to the power battery status, power battery output voltage, steering oil pump input voltage value, and all-in-one controller input voltage signal, which is the battery system or all-in-one controller, auxiliary drive relay or steering oil pump module power distribution fuse or steering oil pump voltage sensor;

[0011] If the fault code type received by the vehicle controller is a module overcurrent fault, the fault point is located based on the steering system status, steering oil pump output current value, and steering oil pump configuration parameter rated current value, which is the steering system or steering oil pump module software version or steering oil pump wiring harness, motor phase or steering oil pump module;

[0012] If the fault code type received by the vehicle controller is a motor overload fault, the fault point is located based on the steering system status, steering wheel status, steering angle status, power battery output voltage, steering oil pump input voltage value, and steering oil pump output current value, and it is found that the fault point is a sudden change in the steering system or motor solidification parameters or the power battery output voltage or the motor torque increase.

[0013] In the above technical solution, the process of locating the over-temperature fault point of the oil pump motor includes:

[0014] Test whether the oil pump motor over-temperature fault is reported in both cold and hot states:

[0015] If the fault is reported only in the cold state but not in the hot state, the fault point is located in the cooling water circuit. Further check the cooling water pump status, water circuit circulation status, and water cooling fan operation status to determine the specific fault point;

[0016] If the fault is reported in both cold and hot states, read the resistance value of the steering oil pump temperature sensor.

[0017] When the resistance value is less than the design value, it is determined that the thermal resistor is damaged; when the resistance value is equal to the design value, check whether the temperature sensor circuit is faulty;

[0018] If the temperature sensor circuit is faulty, the fault is cleared after the wiring harness is repaired;

[0019] If the temperature sensor circuit is not faulty, determine whether the motor controller is faulty;

[0020] If the motor controller is faulty, the fault point is located at the motor controller; if the motor controller is not faulty, the fault point is located at the motor body magnetic demagnetization fault.

[0021] In the above technical solution, the process of further checking the cooling water pump status, water circuit circulation status, and water cooling fan operation status to determine the specific fault point includes:

[0022] Read the cooling system fault code. If a specific fault code is reported, the fault indicated by the water pump system fault code will be processed first;

[0023] If the water pump system confirms that no fault code has been reported and the steering oil pump motor fault has not been eliminated, read the enable status of the water pump feedback and the enable command sent by the vehicle control system;

[0024] If the vehicle requests to be enabled, and the enablement status signal fed back by the water pump system is disabled or unavailable, the water pump is judged to be working abnormally; if the enablement status fed back by the water pump system is effectively enabled, the water pump is judged to be working normally, and the current actual speed value of the water pump fed back by the water pump system and the target speed value of the water pump sent by the vehicle control system are continued to be read;

[0025] If the feedback speed value of the water pump system is less than the target speed value of the vehicle controller system and the difference exceeds the set threshold, it is determined that the cooling fan is not turned on normally;

[0026] If the enabling status is valid and the difference between the cooling water pump feedback speed value and the cooling water pump target value sent by the vehicle control system is within the set threshold, it is determined that the cooling fan has been turned on normally, and the oil pump overtemperature fault point is caused by an error in the water circulation.

[0027] In the above technical solution, the process of locating the output phase failure point includes:

[0028] Read the high-voltage interlock status signal. If the high-voltage interlock fails, it is determined that the high-voltage wiring harness of the steering module is loose or poorly connected.

[0029] If the high-voltage interlock is valid, continue to read the resistance value at both ends of the steering oil pump power line; if the resistance value is not 0, it is determined that the wiring harness inside the steering module is disconnected or poorly connected, choose to repair the faulty line and continue the subsequent positioning process;

[0030] If the resistance value is 0, the wiring harness inside the steering module is normal. Continue to read whether the resistance values ​​between the phases of the three-phase motor of the steering oil pump are consistent. If the resistance error of each phase exceeds the set range, it is determined that the insulation between the phases of the three-phase motor of the steering oil pump is abnormal.

[0031] Read the insulation resistance value of the three-phase motor of the steering oil pump to the ground. If the resistance value is less than the set value, it is determined that the three-phase insulation of the steering oil pump motor to the ground is abnormal;

[0032] If the above judgment conditions are not met, it is determined that the steering motor module current detection circuit fails.

[0033] In the above technical solution, the process of locating the input overvoltage fault point includes:

[0034] Read the power battery fault code. If there is any, give priority to processing the power battery fault. If there is no fault in the power battery, continue to read the steering oil pump input voltage signal value, the all-in-one controller input voltage value, and the power battery output voltage value.

[0035] If the input voltage value of the all-in-one controller is greater than the first voltage threshold and the output voltage value of the power battery is less than the first voltage threshold for more than the set time, check the all-in-one controller or the main relay;

[0036] If the input voltage value of the all-in-one controller is less than the first voltage threshold value, the output voltage value of the power battery is less than the first voltage threshold value, and the input voltage signal value of the steering oil pump is greater than the first voltage threshold value for more than the set time, it is determined that the voltage sensor of the steering oil pump module is damaged;

[0037] If the input voltage value of the all-in-one controller is less than the first voltage threshold and the output voltage value of the power battery is less than the first voltage threshold, and the input voltage signal value of the steering oil pump is less than the first voltage threshold and the duration exceeds the set time, it is determined that the software overvoltage point parameter value is fixed incorrectly and the software version is incorrect.

[0038] In the above technical solution, the process of troubleshooting the all-in-one controller or main relay includes reading the high-voltage distribution box fault. If the high-voltage distribution box reports a fault code, the distribution box fault is handled first; if the distribution box does not report a fault code, the battery main relay status signal is read. If the feedback main relay status signal is that the relay is disconnected, it is determined that the voltage rise is caused by the abnormal disconnection of the main relay.

[0039] In the above technical solution, the process of locating the input undervoltage fault point includes:

[0040] Read the power battery fault code. If there is any, give priority to processing the power battery fault. If there is no fault in the power battery, continue to read the steering oil pump input voltage signal value, the all-in-one controller input voltage value, and the power battery output voltage value.

[0041] If the input voltage value of the all-in-one controller is less than the second voltage threshold and the output voltage value of the power battery is greater than the second voltage threshold and exceeds the set time, check for a fault in the all-in-one controller or a fault in the auxiliary drive contactor;

[0042] If the output voltage value of the power battery is greater than the second voltage threshold and the input voltage signal value of the steering oil pump is less than the second voltage threshold for more than the set time, check whether the power distribution fuse of the steering oil pump distribution module is blown. If the fuse is normal, the diagnostic conclusion is that the steering oil pump module detection voltage sensor is damaged. The fault is cleared after replacing the voltage sensor.

[0043] In the above technical solution, the process of troubleshooting the all-in-one controller fault or the auxiliary drive contactor fault includes:

[0044] Read the high-voltage distribution box fault. If the high-voltage distribution box reports a fault code, give priority to handling the distribution box fault. If the distribution box does not report a fault code, read the auxiliary drive relay status signal fed back by the all-in-one controller. If the auxiliary drive relay status signal fed back by the all-in-one controller is that the relay is disconnected, it is determined that the auxiliary drive relay is abnormally disconnected.

[0045] In the above technical solution, the process of locating the module overcurrent fault point includes:

[0046] Read other fault codes of the steering system. If there are other faults in the steering system, give priority to other steering faults. If there are no other faults in the steering system, continue to read the actual current value of the steering oil pump controller and the rated current value of the steering oil pump controller.

[0047] If the rated current value of the steering oil pump controller is not equal to the set current value or the actual current value of the steering oil pump controller is less than or equal to the product of the rated current value of the steering oil pump controller and the set multiple, it is determined that the software version of the steering oil pump module is wrong;

[0048] If the rated current value of the steering oil pump controller is equal to the set current value and the actual current value of the steering oil pump controller is greater than the product of the rated current value of the steering oil pump controller and the set multiple, check the connection status of the wiring harness and whether the motor phases are short-circuited;

[0049] If the inspection result shows that there is no fault in the circuit, it is determined that the oil pump steering module is damaged and the oil pump steering module needs to be replaced.

[0050] In the above technical solution, the process of locating the motor overload fault point includes:

[0051] Read other fault codes of the steering system. If there are other faults in the steering system, give priority to handling other steering faults;

[0052] If there is no other fault in the steering system, determine whether the steering wheel is turned to the limit or the steering time is too long and exceeds the set time. If it is determined to be so, the artificial motor has been working for too long or the motor curing parameters are unreasonable;

[0053] If the above situation is excluded, read the power battery output voltage; if the power battery output voltage is less than the set value, it is determined that the power battery output voltage is too low; if the power battery voltage output is normal, check the motor load value change curve to see if there is a sudden load change.

[0054] The beneficial effect of the present invention is that the present invention can locate the specific locations where different faults occur based on the fault type fed back by the vehicle fault code in combination with the vehicle status information, thereby facilitating subsequent repair work on the fault point, improving the fault repair efficiency of the steering oil pump and effectively saving costs.

[0055] Furthermore, for motor overtemperature failure, the present invention first distinguishes between cold and hot fault information, effectively clarifies the fault location route, narrows the scope of fault location, and improves the efficiency of fault location; the present invention can check possible fault points in turn along the corresponding fault location route to ensure the accuracy of positioning.

[0056] Furthermore, for the output phase loss fault, the present invention checks the possible fault points in sequence according to the line layout, effectively improving the efficiency of positioning and not missing the possible fault points. At the same time, the present invention determines the status of each device by direct reading, and the positioning process is simple and easy to operate.

[0057] Furthermore, for the input overvoltage fault point, the present invention checks the voltages of the all-in-one controller, the main relay and the sensor in sequence according to the set voltage threshold, and then locates the device where the input voltage overvoltage may occur, avoiding omissions and misjudgments.

[0058] Furthermore, for the input voltage fault point, the present invention checks the voltages of the all-in-one controller, the main relay and the sensor in sequence according to the set voltage threshold, and then locates the device where the input voltage overvoltage may occur, avoiding omissions and misjudgments.

[0059] Furthermore, for the module overcurrent fault point, the present invention checks the steering oil pump controller current in sequence according to the set current threshold, and then locates the possible cause of the module current, avoiding omissions and misjudgment.

[0060] Furthermore, for motor overload failure, the present invention combines the vehicle motion state and battery voltage information to check possible motor failures in turn, thereby clarifying the cause of the motor failure and improving the precision of positioning. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 It is a schematic diagram of the method flow of the present invention;

[0062] Figure 2 The motor over-temperature fault location process of the present invention;

[0063] Figure 3 This is the output phase loss fault locating process of the present invention;

[0064] Figure 4 The input overvoltage fault diagnosis process of the present invention;

[0065] Figure 5 This is the input undervoltage fault diagnosis process of the present invention;

[0066] Figure 6 This is the module overcurrent fault diagnosis process of the present invention;

[0067] Figure 7 The motor overload fault diagnosis process of the present invention;

[0068] Figure 8 This is the connection diagram of the steering oil pump module. DETAILED DESCRIPTION

[0069] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments to facilitate a clear understanding of the present invention, but they do not constitute a limitation on the present invention.

[0070] like Figure 1 As shown, the present invention provides a fault locating method for an electric steering oil pump module of a pure electric commercial vehicle, comprising the following steps:

[0071] The vehicle controller receives the fault code reported by the electric steering oil pump module;

[0072] If the fault code type received by the vehicle controller is an oil pump motor overtemperature fault, the fault point is located according to the temperature control operation status, the resistance value of the steering oil pump temperature sensor, and the fault status of the motor controller, which is the water pump, water circuit, cooling fan, or steering oil pump thermal resistor or temperature sensor harness or motor control or motor body;

[0073] If the fault code type received by the vehicle controller is an output phase loss fault, the fault point is located according to the high-voltage interlocking state of the steering oil pump, the resistance of the steering oil pump harness end, the phase-to-phase resistance, and the insulation resistance to ground. It is the steering oil pump external high-voltage harness or the steering oil pump internal harness or the three-phase motor phase-to-phase or the three-phase motor to ground or the steering oil pump module current detection module;

[0074] If the fault code type received by the vehicle controller is an input overvoltage fault, the fault point is located according to the power battery status, power battery output voltage, steering oil pump input voltage value, and all-in-one controller input voltage signal, which is the battery system or all-in-one controller, main relay or voltage sensor, or steering oil pump controller software version;

[0075] If the fault code type received by the vehicle controller is an input undervoltage fault, the fault point is located according to the power battery status, power battery output voltage, steering oil pump input voltage value, and all-in-one controller input voltage signal, which is the battery system or all-in-one controller, auxiliary drive relay or steering oil pump module power distribution fuse or steering oil pump voltage sensor;

[0076] If the fault code type received by the vehicle controller is a module overcurrent fault, the fault point is located based on the steering system status, steering oil pump output current value, and steering oil pump configuration parameter rated current value, which is the steering system or steering oil pump module software version or steering oil pump wiring harness, motor phase or steering oil pump module;

[0077] If the fault code type received by the vehicle controller is a motor overload fault, the fault point is located based on the steering system status, steering wheel status, steering angle status, power battery output voltage, steering oil pump input voltage value, and steering oil pump output current value, and it is found that the fault point is a sudden change in the steering system or motor solidification parameters or the power battery output voltage or the motor torque increase.

[0078] In the specific embodiment 1, the steering oil pump is referred to as HSCU.

[0079] After the driver operates the electric vehicle key from OFF to ON, the vehicle enters the high-voltage power-on completion state. The electric HSCU should always remain in operation. The connection diagram of the HSCU module and other vehicle modules is as follows: Figure 8 At this time, the HSCU module unexpectedly shuts down and reports the fault code to the vehicle controller, which then performs the following positioning method:

[0080] 1. If the fault code type reported by HSCU is oil pump motor overtemperature fault. Figure 2 As shown, the method for locating the fault point at this time includes:

[0081] Test whether the fault is reported in both cold and hot states. If the fault is reported only in cold state but not in hot state, the faulty component is located as the cooling water circuit. Further check the cooling water pump status, water circuit circulation status, and water cooling fan operating status to determine the specific fault point.

[0082] The specific positioning method is to read the cooling system of the all-in-one controller (such as Figure 8 If there is a specific fault code reported, such as overpressure, underpressure, overspeed, stall, fault, etc. in the water pump system, or motor stall, etc., the fault indicated by the water pump system fault code will be processed first;

[0083] If the water pump system confirms that no fault code has been reported and the HSCU oil pump motor fault has not been eliminated, the enable status fed back by the water pump and the enable command sent by the vehicle control system are read. If the vehicle requests to be enabled and the enable status signal fed back by the cooling water pump system is disabled or unavailable, it is determined that the cooling water pump system is working abnormally. If the enable status fed back by the cooling water pump system is effectively enabled, it is determined that the cooling water pump is working normally.

[0084] Continue to read the actual speed of the water pump fed back by the cooling water pump system and the target speed of the water pump sent by the vehicle control system. If the speed of the water pump system fed back is less than the target speed of the vehicle controller system and the difference exceeds 200r / min, it is determined that the cooling fan is not turned on normally.

[0085] If the enabling status is valid and the difference between the cooling water pump feedback speed value and the cooling water pump target value sent by the vehicle control system is within 200r / min, it is determined that the cooling fan has been turned on normally, and the oil pump overtemperature fault point is caused by an error in the water circulation.

[0086] If the fault is reported in both cold and hot states, read the resistance value of the temperature sensor. When the actual resistance value is less than the design value, it is judged as a thermal resistor damage fault. When the actual resistance value is equal to the design value, check the temperature sensor circuit for loose wiring harness, enlarged hole, virtual connection, etc., resulting in short circuit or short circuit fault.

[0087] If the circuit is faulty, the fault is cleared after the wiring harness is repaired. If the circuit is not faulty, the motor controller status is obtained to determine the motor controller fault. If the motor controller is not faulty, the fault point is located as the motor body demagnetization fault.

[0088] 2. If the fault code type reported by HSCU is output phase loss. Figure 3 As shown, the method for locating the fault point at this time includes:

[0089] Read the high-voltage interlock status signal, where the high-voltage interlock status signal is detected by the all-in-one controller and then reported to the vehicle controller through the CAN signal;

[0090] If the high-voltage interlock fails, the high-voltage wiring harness of the steering oil pump module is loose or poorly connected. The fault is cleared after the wiring harness is correctly connected.

[0091] If the high-voltage interlock is valid, continue to read the resistance value at both ends of the HSCU power line; if the resistance value is not 0, the wiring harness inside the steering module is disconnected or poorly connected, and the fault is cleared after the wiring harness is correctly connected;

[0092] If the resistance value is 0, the wiring harness inside the steering module is normal. Continue to read the resistance values ​​between the motor UV / VW / WU to see if they are consistent. If the resistance error is within ±5%, it is normal. If it exceeds ±5%, it is determined that the insulation between the three-phase motor of the steering oil pump is abnormal.

[0093] Read the insulation resistance value of the steering motor to ground. If the resistance is less than 4MΩ, it is determined that the three-phase insulation of the steering oil pump motor to ground is abnormal. If the above judgment conditions are not met, the cause of the fault is determined to be the failure of the current detection circuit of the steering motor module. After replacing the all-in-one controller, the fault is cleared.

[0094] 3. If the fault code type reported by HSCU is input overvoltage. Figure 4 As shown, the method for locating the fault point at this time includes:

[0095] Read the power battery fault code. If there is any, the power battery fault will be dealt with first. Battery fault diagnosis and treatment will not be expanded here.

[0096] If the power battery has no fault, continue to read the HSCU input voltage signal value Ud, read the all-in-one controller input voltage value Ue, and the power battery output voltage value Uf;

[0097] If Ue>775 and Uf<775 exceeds 5ms, it is necessary to check the multi-in-one fault or the abnormal disconnection of the main relay causing the voltage rise. The specific troubleshooting method is: read the high-voltage distribution box fault. If the high-voltage distribution box reports a fault code, such as an overvoltage fault, an overcurrent fault, etc., then give priority to handling the distribution box fault. If the distribution box has no fault code reported, read the battery main relay status signal. If the feedback main relay status signal is that the relay is disconnected, it is determined that the voltage rise is caused by the abnormal disconnection of the main relay.

[0098] If Ue<775 and Uf<775 and Ud>775 exceeds 5ms, the diagnosis conclusion is that the HSCU module voltage sensor is damaged. The fault is cleared after replacing the voltage sensor.

[0099] If Ue<775V and Uf<775V, and Ud<775 and the duration exceeds 5 milliseconds, it is judged that the software overvoltage point parameter value is incorrectly fixed and the software version is wrong.

[0100] 4. If the fault code type reported by HSCU is input undervoltage. Figure 5 As shown, the method for locating the fault point at this time includes:

[0101] Read the power battery fault code. If there is any, the power battery fault is handled first. The battery fault diagnosis and treatment are not expanded here. If the power battery has no fault, continue to read the HSCU input voltage signal value Ud, read the all-in-one controller input voltage value Ue, and the power battery output voltage value Uf;

[0102] If Ue<400 and Uf>400 exceeds 5ms, it is necessary to check the multi-in-one fault or auxiliary drive contactor fault. The specific troubleshooting method is: read the high-voltage distribution box fault. If the high-voltage distribution box reports a fault code, such as an undervoltage fault, the distribution box fault is handled first. If the distribution box has no fault code reported, read the auxiliary drive relay status signal fed back by the multi-in-one. If the auxiliary drive relay status signal fed back by the multi-in-one module is that the relay is disconnected, it is determined that the auxiliary drive relay is abnormally disconnected.

[0103] If Uf>400 and Ud<400 for more than 5ms, check whether the HSCU power distribution module power distribution fuse is blown. If the fuse is normal, the diagnosis conclusion is that the HSCU module detection voltage sensor is damaged. After replacing the voltage sensor, the fault is cleared.

[0104] 5. If the fault code type reported by HSCU is module overcurrent fault. Figure 6 As shown, the method for locating the fault point at this time includes:

[0105] Read other fault codes of the steering system. If any, give priority to other steering faults. Steering fault diagnosis and treatment will not be expanded here;

[0106] If there is no other fault in the steering system, continue to read the actual current value Ia of the HSCU controller and the rated current value Ib of the HSCU controller;

[0107] If the Ib value is not equal to 13A or Ia<=Ib*2.2, the diagnosis conclusion is that the HSCU module software version is wrong;

[0108] If the read Ib value is equal to 13A and Ia>Ib*2.2, check the wiring harness connection status and whether the motor phases are short-circuited. If there is no fault in the electrical circuit, the diagnosis conclusion is that the HSCU module is damaged. After replacing the HSCU module, the fault is cleared.

[0109] 6. If the fault code type reported by HSCU is motor overload fault. Figure 7 As shown, the method for locating the fault point at this time includes:

[0110] Read other fault codes of the steering system. If any, give priority to other steering faults, such as motor rotor jam and other mechanical faults. The diagnosis and treatment of other steering faults will not be expanded here;

[0111] If there are no other faults in the steering system, determine whether the steering wheel is turned to the limit or the steering time is too long, exceeding 5 minutes. In this case, the motor is working for too long or the motor curing parameters are unreasonable.

[0112] If this situation is excluded, read the HSCU input voltage value Ud, the all-in-one controller input voltage Ue, and the power battery output voltage Uf;

[0113] If Uf<500V, the diagnostic conclusion is that the power battery output voltage is too low.

[0114] If the power battery voltage output is normal, check the motor load value change curve to see if there is a sudden load change. The specific method is to query the motor load MAP diagram and find the point in the diagram where the slope of the curve suddenly changes: calculate the actual slope of the point and the slopes of other points. If the slope of this point exceeds 50% of the slopes of other points, adjust the torque boost amount to smooth the MAP diagram. Update the software and clear the fault.

[0115] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

Claims

1. A fault location method for an electric steering oil pump module of a pure electric commercial vehicle, characterized in that: The following steps are involved: The vehicle controller receives the fault code reported by the electric steering oil pump module; If the fault code type received by the vehicle controller is an oil pump motor overtemperature fault, the fault point is located according to the temperature control operation status, the resistance value of the steering oil pump temperature sensor, and the fault status of the motor controller, which is the water pump, water circuit, cooling fan, or steering oil pump thermal resistor or temperature sensor harness or motor control or motor body; If the fault code type received by the vehicle controller is an output phase loss fault, the fault point is located according to the high-voltage interlocking state of the steering oil pump, the resistance of the steering oil pump harness end, the phase-to-phase resistance, and the insulation resistance to ground. It is the steering oil pump external high-voltage harness or the steering oil pump internal harness or the three-phase motor phase-to-phase or the three-phase motor to ground or the steering oil pump module current detection module; If the fault code type received by the vehicle controller is an input overvoltage fault, the fault point is located according to the power battery status, power battery output voltage, steering oil pump input voltage value, and all-in-one controller input voltage signal, which is the battery system or all-in-one controller, main relay or voltage sensor, or steering oil pump controller software version; If the fault code type received by the vehicle controller is an input undervoltage fault, the fault point is located according to the power battery status, power battery output voltage, steering oil pump input voltage value, and all-in-one controller input voltage signal, which is the battery system or all-in-one controller, auxiliary drive relay or steering oil pump module power distribution fuse or steering oil pump voltage sensor; If the fault code type received by the vehicle controller is a module overcurrent fault, the fault point is located based on the steering system status, steering oil pump output current value, and steering oil pump configuration parameter rated current value, which is the steering system or steering oil pump module software version or steering oil pump wiring harness, motor phase or steering oil pump module; If the fault code type received by the vehicle controller is a motor overload fault, the fault point is located based on the steering system status, steering wheel status, steering angle status, power battery output voltage, steering oil pump input voltage value, and steering oil pump output current value, and it is found that the fault point is a sudden change in the steering system or motor solidification parameters or the power battery output voltage or the motor torque increase.

2. A method according to claim 1, characterized in that: The process of locating the oil pump motor overtemperature fault point includes: Test whether the oil pump motor over-temperature fault is reported in both cold and hot states: If the fault is reported only in the cold state but not in the hot state, the fault point is located in the cooling water circuit. Further check the cooling water pump status, water circuit circulation status, and water cooling fan operation status to determine the specific fault point; If the fault is reported in both cold and hot states, read the resistance value of the steering oil pump temperature sensor. When the resistance value is less than the design value, it is determined that the thermal resistor is damaged; when the resistance value is equal to the design value, check whether the temperature sensor circuit is faulty; If the temperature sensor circuit is faulty, the fault is cleared after the wiring harness is repaired; If the temperature sensor circuit is not faulty, determine whether the motor controller is faulty; If the motor controller is faulty, the fault point is located at the motor controller; if the motor controller is not faulty, the fault point is located at the motor body magnetic demagnetization fault.

3. A method according to claim 2, characterized in that: The process of further checking the cooling water pump status, water circulation status, and water cooling fan operation status to determine the specific fault point includes: Read the cooling system fault code. If a specific fault code is reported, the fault indicated by the water pump system fault code will be processed first; If the water pump system confirms that no fault code has been reported and the steering oil pump motor fault has not been eliminated, read the enable status of the water pump feedback and the enable command sent by the vehicle control system; If the vehicle requests to be enabled, and the enablement status signal fed back by the water pump system is disabled or unavailable, the water pump is judged to be working abnormally; if the enablement status fed back by the water pump system is effectively enabled, the water pump is judged to be working normally, and the current actual speed value of the water pump fed back by the water pump system and the target speed value of the water pump sent by the vehicle control system are continued to be read; If the feedback speed value of the water pump system is less than the target speed value of the vehicle controller system and the difference exceeds the set threshold, it is determined that the cooling fan is not turned on normally; If the enabling status is valid and the difference between the cooling water pump feedback speed value and the cooling water pump target value sent by the vehicle control system is within the set threshold, it is determined that the cooling fan has been turned on normally, and the oil pump overtemperature fault point is caused by an error in the water circulation.

4. A method according to claim 1, characterized in that: The process of locating the output phase failure point includes: Read the high-voltage interlock status signal. If the high-voltage interlock fails, it is determined that the high-voltage wiring harness of the steering module is loose or poorly connected. If the high-voltage interlock is valid, continue to read the resistance value at both ends of the steering oil pump power line; if the resistance value is not 0, it is determined that the wiring harness inside the steering module is disconnected or poorly connected, choose to repair the faulty line and continue the subsequent positioning process; If the resistance value is 0, the wiring harness inside the steering module is normal. Continue to read whether the resistance values ​​between the phases of the three-phase motor of the steering oil pump are consistent. If the resistance error of each phase exceeds the set range, it is determined that the insulation between the phases of the three-phase motor of the steering oil pump is abnormal. Read the insulation resistance value of the three-phase motor of the steering oil pump to the ground. If the resistance value is less than the set value, it is determined that the three-phase insulation of the steering oil pump motor to the ground is abnormal; If the above judgment conditions are not met, it is determined that the steering motor module current detection circuit fails.

5. A method according to claim 1, characterized in that: The process of locating the input overvoltage fault point includes: Read the power battery fault code. If there is any, give priority to processing the power battery fault. If there is no fault in the power battery, continue to read the steering oil pump input voltage signal value, the all-in-one controller input voltage value, and the power battery output voltage value. If the input voltage value of the all-in-one controller is greater than the first voltage threshold and the output voltage value of the power battery is less than the first voltage threshold for more than the set time, check the all-in-one controller or the main relay; If the input voltage value of the all-in-one controller is less than the first voltage threshold value, the output voltage value of the power battery is less than the first voltage threshold value, and the input voltage signal value of the steering oil pump is greater than the first voltage threshold value for more than the set time, it is determined that the voltage sensor of the steering oil pump module is damaged; If the input voltage value of the all-in-one controller is less than the first voltage threshold and the output voltage value of the power battery is less than the first voltage threshold, and the input voltage signal value of the steering oil pump is less than the first voltage threshold and the duration exceeds the set time, it is determined that the software overvoltage point parameter value is fixed incorrectly and the software version is incorrect.

6. A method according to claim 5, characterized in that: The process of troubleshooting the all-in-one controller or main relay includes reading the high-voltage distribution box fault. If the high-voltage distribution box reports a fault code, the distribution box fault is handled first; If the distribution box does not report a fault code, the battery main relay status signal is read. If the feedback main relay status signal shows that the relay is disconnected, it is determined that the voltage rise is caused by abnormal disconnection of the main relay.

7. A method according to claim 1, characterized in that: The process of locating the input undervoltage fault point includes: Read the power battery fault code. If there is any, give priority to processing the power battery fault. If there is no fault in the power battery, continue to read the steering oil pump input voltage signal value, the all-in-one controller input voltage value, and the power battery output voltage value. If the input voltage value of the all-in-one controller is less than the second voltage threshold and the output voltage value of the power battery is greater than the second voltage threshold and exceeds the set time, check for a fault in the all-in-one controller or a fault in the auxiliary drive contactor; If the output voltage value of the power battery is greater than the second voltage threshold and the input voltage signal value of the steering oil pump is less than the second voltage threshold for more than the set time, check whether the power distribution fuse of the steering oil pump distribution module is blown. If the fuse is normal, the diagnostic conclusion is that the steering oil pump module detection voltage sensor is damaged. The fault is cleared after replacing the voltage sensor.

8. A method according to claim 7, characterized in that: The process of troubleshooting an all-in-one controller fault or an auxiliary drive contactor fault includes: Read the high-voltage distribution box fault. If the high-voltage distribution box reports a fault code, give priority to handling the distribution box fault. If the distribution box does not report a fault code, read the auxiliary drive relay status signal fed back by the all-in-one controller. If the auxiliary drive relay status signal fed back by the all-in-one controller is that the relay is disconnected, it is determined that the auxiliary drive relay is abnormally disconnected.

9. A method according to claim 1, characterized in that: The process of locating the module overcurrent fault point includes: Read other fault codes of the steering system. If there are other faults in the steering system, give priority to handling other steering faults; if there are no other faults in the steering system, continue to read the actual current value of the steering oil pump controller and the rated current value of the steering oil pump controller; If the rated current value of the steering oil pump controller is not equal to the set current value or the actual current value of the steering oil pump controller is less than or equal to the product of the rated current value of the steering oil pump controller and the set multiple, it is determined that the software version of the steering oil pump module is wrong; If the rated current value of the steering oil pump controller is equal to the set current value and the actual current value of the steering oil pump controller is greater than the product of the rated current value of the steering oil pump controller and the set multiple, check the connection status of the wiring harness and whether the motor phases are short-circuited; If the inspection result shows that there is no fault in the circuit, it is determined that the oil pump steering module is damaged and the oil pump steering module needs to be replaced.

10. A method according to claim 1, characterized in that: The process of locating the motor overload fault point includes: Read other fault codes of the steering system. If there are other faults in the steering system, give priority to handling other steering faults; If there is no other fault in the steering system, determine whether the steering wheel is turned to the limit or the steering time is too long and exceeds the set time. If it is determined to be so, the artificial motor has been working for too long or the motor curing parameters are unreasonable; If the above situation is excluded, read the power battery output voltage; if the power battery output voltage is less than the set value, it is determined that the power battery output voltage is too low; if the power battery voltage output is normal, check the motor load value change curve to see if there is a sudden load change.

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