A new energy commercial vehicle electric drive axle gear shift stall fault diagnosis method and system

Abstract

The application discloses a new energy commercial vehicle electric drive axle gear shifting stall fault diagnosis method and system, and belongs to the technical field of vehicles. The method comprises the following steps: in response to receiving a gear shifting request instruction of a driver, a gear shifting mechanism is controlled to perform gear shifting; the duty cycle, the duration and the current of H-bridge driving output by a gear shifting controller in the gear shifting process, and the voltage fed back by a gear shifting mechanism position sensor are acquired; the change value of the duty cycle, the duration, the current value of H-bridge driving and the voltage fed back by the gear shifting mechanism position sensor within a preset time threshold are compared with preset threshold values respectively, and whether the gear shifting mechanism has a stall fault is judged based on the comparison result; if the gear shifting mechanism has a stall fault, a repair control instruction is executed. The application can quickly and accurately determine whether the gear shifting mechanism has a stall fault, so that safety hazards can be found in time and repaired, and the safety of the vehicle is improved.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and in particular to a method and system for diagnosing gear shifting stall faults in electric drive axles of new energy commercial vehicles. Background Technology

[0002] With the rapid development and widespread application of electric drive axles in new energy commercial vehicles, severe reliability challenges are faced in harsh working conditions such as mountainous areas and mines. The shifting mechanism of the electric drive axle is subjected to heavy-load impacts, vibrations, and dust intrusion, leading to mechanical wear and jamming risks, and resulting in shifting stall failures. While related technologies exist that classify severity levels based on the number of failures and implement different post-processing mechanisms, there are still significant shortcomings in the completeness and safety of handling shifting stall failures. Summary of the Invention

[0003] The purpose of this invention is to provide a method and system for diagnosing gear shifting stall faults in electric drive axles of new energy commercial vehicles, which can improve the reliability of the gear shifting process and solve the problems of insufficient completeness and safety in the handling of gear shifting stall faults in related technologies.

[0004] To solve the above-mentioned technical problems, the present invention is implemented using the following technical solution:

[0005] On the one hand, the present invention provides a method for diagnosing gear shifting stall faults in the electric drive axle of new energy commercial vehicles, including the following steps:

[0006] In response to receiving a shift request command from the driver, the shift mechanism is controlled to shift gears;

[0007] The duty cycle, duration, and current of the H-bridge drive output by the shift controller during the shift process, as well as the voltage fed back by the shift mechanism position sensor, are obtained.

[0008] The duty cycle, duration, current value of the H-bridge drive, and the voltage change value fed back by the position sensor of the shift mechanism within a preset time threshold are compared with their preset thresholds, and the shift mechanism is judged to have a stall fault based on the comparison results.

[0009] If the shifting mechanism experiences a stall fault, a repair control command is executed.

[0010] Optionally, a stall fault in the shifting mechanism is determined when the following conditions are met simultaneously:

[0011] The duty cycle is greater than the preset threshold PWM1;

[0012] The duration is greater than a preset threshold T1;

[0013] The current is greater than a preset threshold I1;

[0014] The voltage change value fed back by the position sensor of the shift mechanism within the preset time threshold T2 is less than the preset threshold U1.

[0015] Optionally, the shift control command includes a disengagement request command or an engagement request command. If a stall fault occurs in the shift mechanism, a repair control command is executed, including:

[0016] When the shift request command is a disengagement request command, and it is determined that a stall fault has occurred in the shift mechanism, the first repair control command is executed;

[0017] When the shift request command is an upshift request command and it is determined that the shift mechanism has a stall fault, the second repair control command is executed.

[0018] Optionally, the first repair control command includes:

[0019] Control the shifting mechanism to reverse drive and disengage the gear, record the number of reverse drive times of the shifting mechanism, and determine whether the shifting mechanism has switched to neutral.

[0020] If so, continue executing the gear shifting process, and clear the gear shift stall fault flag and the number of reverse drive cycles of the gear shifting mechanism to zero;

[0021] If not, determine whether the number of reverse drives of the shift mechanism is greater than the preset threshold N1. If the number of reverse drives of the shift mechanism is greater than the preset threshold N1, control the shift mechanism to switch to the previous target gear, and record one failure of the shift mechanism to disengage the gear. At the same time, limit the current vehicle speed to the maximum vehicle speed threshold V1 of the lower gear in the middle and rear axles.

[0022] Optionally, after limiting the vehicle speed to the maximum speed threshold V1 of the lower gear in the middle and rear axles, within a preset time threshold T3, in response to receiving a driver's request to disengage the gear shifting mechanism, the gear shifting mechanism is disengaged.

[0023] Determine whether the gear shifting mechanism has switched to neutral;

[0024] If so, continue the gear shifting process, reset the number of failed gear disengagement attempts of the gear shifting mechanism to zero, and remove the vehicle speed limit;

[0025] If not, execute the first repair control command;

[0026] When executing the first repair instruction, if the number of reverse drives of the shift mechanism is greater than the preset threshold N1, a shift failure is recorded once;

[0027] When the number of failed gear shifts within the preset time threshold T3 exceeds the preset threshold N2, the first safety control command is executed based on the current vehicle speed.

[0028] Optionally, the first safety control command is executed based on the current vehicle speed, including:

[0029] If the current vehicle speed is greater than the preset threshold V2, the torque sent by the shift controller to the motor controller is cleared to zero, the instrument alarm is triggered, and the hazard warning lights are automatically turned on.

[0030] If the vehicle speed is less than or equal to the set threshold V2, control the vehicle to issue a reminder to pull over for maintenance.

[0031] Optionally, the second repair control command includes:

[0032] The shift controller controls the shift mechanism to return to neutral and engage a gear. After each engagement, the number of times the shift mechanism returns to neutral is recorded, and it is determined whether the shift mechanism has switched to the target gear.

[0033] If so, continue executing the gear shifting process and clear the gear shift stall fault flag and the number of times the gear shifting mechanism has returned to zero;

[0034] If not, determine whether the number of times the shift mechanism returns to neutral is greater than the set threshold N3. When the number of times the shift mechanism returns to neutral is greater than the set threshold N3, the shift controller controls the shift mechanism to switch to the previous target gear and counts the number of times the shift mechanism fails to engage gear. At the same time, the vehicle speed is limited to the maximum vehicle speed threshold V3 of the lower gear of the middle and rear axles.

[0035] Optionally, after limiting the vehicle speed to the maximum speed threshold V3 of the lower gear in the middle and rear axles, within a preset time threshold T4, in response to receiving the driver's gear shifting request command, the gear shifting mechanism is shifted to the next gear, and it is determined whether the gear shifting mechanism has switched to the target gear.

[0036] If so, the number of failed gear shifts for the gear shifting mechanism is reset to zero, and the vehicle speed limit is lifted;

[0037] If not, execute the second repair control command;

[0038] When executing the second repair control command, if the number of times the shifting mechanism returns to neutral exceeds the set threshold N3, a shifting failure is recorded once;

[0039] When the number of failed gear shifts exceeds the preset threshold N4, the first safety control command is executed based on the current vehicle speed.

[0040] Optionally, a second safety control command may be executed based on the current vehicle speed, including:

[0041] If the current vehicle speed is greater than the preset threshold V4, the torque sent by the shift controller to the motor controller is cleared to zero, the instrument alarm is triggered, and the hazard warning lights are automatically turned on.

[0042] If the vehicle speed is less than or equal to the set threshold V4, control the vehicle to issue a reminder to pull over for maintenance.

[0043] On the other hand, the present invention provides a fault diagnosis system for gear shifting stall in electric drive axle of new energy commercial vehicle. The system includes: a receiving module, which is used to receive a shifting request command from the driver to the shifting mechanism;

[0044] The acquisition module is used to acquire the duty cycle, duration and current of the H-bridge drive output by the shift controller during the shift process, as well as the voltage fed back by the position sensor of the shift mechanism.

[0045] The comparison and judgment module is used to compare the duty cycle, duration, current value of the H-bridge drive and the voltage change value fed back by the shift mechanism position sensor within a preset time threshold with their preset thresholds, and to determine whether the shift mechanism has a stall fault based on the comparison results.

[0046] A control module, which is used to execute repair control commands based on the shift request command and the judgment result.

[0047] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: By comparing the duty cycle, duration, current value of the H-bridge drive and the voltage change value fed back by the position sensor of the shift mechanism within a preset time threshold during the shifting process with their preset thresholds, the present invention can quickly and accurately determine whether the shifting mechanism has a stall fault, promptly detect safety hazards and repair them, thereby improving vehicle safety.

[0048] Furthermore, this invention achieves full-process coverage of fault handling through a complete closed loop, from fault detection and attempted repair to repair failure and fault reporting and maintenance. This avoids the inefficiency or safety hazards caused by a one-size-fits-all approach and reduces the risk of mechanical damage. At the same time, by limiting the speed, it creates a time window and safety boundary for the recovery of the faulty bridge, which can improve the robustness and reliability of the system. Attached Figure Description

[0049] To more clearly illustrate the technical solutions in the embodiments or related technologies of this disclosure, the accompanying drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0050] Figure 1 This is a flowchart illustrating a method for diagnosing stall faults in the electric drive axle of a new energy commercial vehicle, provided in an embodiment of the present invention.

[0051] Figure 2 This is a schematic diagram of a stalling process provided in an embodiment of the present invention;

[0052] Figure 3 This is a schematic diagram of a gear shift stall process provided by an embodiment of the present invention. Detailed Implementation

[0053] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure / invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0054] Example 1

[0055] This embodiment describes a method for diagnosing shift stall faults in the electric drive axle of new energy commercial vehicles, referencing... Figure 1 The fault diagnosis method for gear shifting stall in the electric drive axle of a new energy commercial vehicle in this embodiment includes the following steps:

[0056] S1, in response to receiving a shift request command from the driver, controls the shift mechanism to perform a shift.

[0057] The shift control commands include a disengagement request command or an engagement request command. When a disengagement request command is received from the driver, the shift mechanism is controlled to disengage, that is, to shift from the current gear to neutral. When an engagement request command is received from the driver, the shift mechanism is controlled to engage, that is, to shift from neutral to the target gear.

[0058] S2, acquire the duty cycle, duration and current of the H-bridge drive output by the shift controller during the shift process, as well as the voltage fed back by the shift mechanism position sensor.

[0059] S3 compares the duty cycle, duration, current value of the H-bridge drive, and the voltage change value fed back by the shift mechanism position sensor within a preset time threshold with their preset thresholds, and determines whether the shift mechanism has a stall fault based on the comparison results.

[0060] The shifting mechanism is considered to have stalled when the following conditions are met simultaneously:

[0061] The duty cycle is greater than the preset threshold PWM1;

[0062] The duration exceeds the preset threshold T1;

[0063] The current is greater than the preset threshold I1;

[0064] The change in voltage fed back by the position sensor of the shift mechanism within a preset time threshold T2 is less than the preset threshold U1.

[0065] S4, if a stall fault occurs in the shifting mechanism, execute the repair control command.

[0066] refer to Figure 2 and Figure 3 In this embodiment, the stall fault can be divided into disengagement stall and engagement stall. When the shift request command is a disengagement request command and a stall fault is determined to have occurred in the shift mechanism, the stall fault is disengagement stall. When the shift request command is an engagement request command and a stall fault is determined to have occurred in the shift mechanism, the stall fault is engagement stall.

[0067] refer to Figure 2 When the stall fault is due to stalling during gear disengagement, the first repair control command is executed, including:

[0068] Control the shift mechanism to reverse drive and disengage the gear, record the number of reverse drive times of the shift mechanism, and determine whether the shift mechanism has switched to neutral.

[0069] If the shift mechanism switches to neutral, the shift process continues, and the shift stall fault flag and the number of reverse drive counts of the shift mechanism are cleared to zero.

[0070] If the shift mechanism cannot shift to neutral, it checks whether the number of reverse drive cycles of the shift mechanism exceeds a preset threshold N1. If the number of reverse drive cycles exceeds the preset threshold N1, it controls the shift mechanism to switch to the previous target gear, counts the number of failed shifts, and limits the current vehicle speed to the maximum speed threshold V1 of the lower gear in the middle and rear axles.

[0071] V1 = (0.377 * r * n) / i, where r is the wheel rolling radius, n is the maximum speed of the motor, and i is the gear ratio of the electric drive axle.

[0072] If the number of reverse drives of the shift mechanism is not greater than the preset threshold N1, then the shift mechanism will continue to be controlled to reverse drive and disengage the gear until the shift mechanism switches to neutral or the number of reverse drives of the shift mechanism is greater than the preset threshold N1.

[0073] After limiting the vehicle speed to the maximum speed threshold V1 of the lower gear in the middle and rear axles, within the preset time threshold T3, when the vehicle shifts gears again as the vehicle speed changes, it is determined whether the shifting mechanism has switched to neutral after each shift.

[0074] If the shift mechanism switches to neutral, the shift process continues, the number of failed shifts is reset to zero, and the speed limit is lifted.

[0075] If the shifting mechanism still cannot switch to neutral, the first repair control command will continue to be executed.

[0076] If the shift mechanism still cannot switch to neutral after the first repair control command is executed, and the number of reverse drive times of the shift mechanism is greater than the preset threshold N1, then a shift failure is recorded.

[0077] When the number of failed gear shifts exceeds a preset threshold N2 within a preset time threshold T3, a first safety control command is executed based on the current vehicle speed, including:

[0078] If the current vehicle speed exceeds the preset threshold V2, the torque sent by the shift controller to the motor controller will be zeroed, the control instrument will alarm and the hazard warning lights will be automatically turned on to alert the driver and vehicles behind. The vehicle can then coast to a safe area for maintenance of the electric drive axle shift mechanism.

[0079] If the vehicle speed is less than or equal to the set threshold V2, the vehicle will issue a pullover maintenance reminder, prompting the driver to immediately pull over for maintenance of the electric drive axle shift mechanism.

[0080] refer to Figure 3 When the stall fault is gear engagement stall, the second repair control command is executed, including:

[0081] The shift controller controls the shift mechanism to return to neutral and engage a gear. After each engagement, it records the number of times the shift mechanism returns to neutral and determines whether the shift mechanism has switched to the target gear.

[0082] If the shift mechanism switches to the target gear, the shift process continues, and the shift stall fault flag and the number of shift mechanism return cycles are reset to zero.

[0083] If the shifting mechanism cannot switch to the target gear, it is determined whether the number of times the shifting mechanism returns to neutral is greater than the set threshold N3. When the number of times the shifting mechanism returns to neutral is greater than the set threshold N3, the shifting controller controls the shifting mechanism to switch to the previous target gear, while limiting the vehicle speed to the maximum speed threshold V3 of the lower gear of the middle and rear axles, and counting the number of times the shifting mechanism fails to shift gears.

[0084] After limiting the vehicle speed to the maximum speed threshold V3 of the lower gear in the middle and rear axles, within the preset time threshold T4, when the vehicle shifts gears again as the vehicle speed changes, it is determined whether the shifting mechanism has switched to the target gear after each shift.

[0085] If so, reset the number of failed gear shifts to zero and remove the speed limit;

[0086] If not, execute the second repair control command;

[0087] When executing the second repair control command, if the number of times the shift mechanism returns to neutral exceeds the set threshold N3, a shift failure is recorded.

[0088] When the number of failed gear shifts exceeds the preset threshold N4, a second safety control command is executed based on the current vehicle speed.

[0089] Record one failed shifting action of the gear shifting mechanism and determine whether the total number of failed shifting actions of the gear shifting mechanism exceeds the preset threshold N4;

[0090] If the number of failed gear shifts exceeds the set threshold N4, a second safety control command is executed based on the current vehicle speed, including:

[0091] If the current vehicle speed exceeds the preset threshold V4, the torque sent by the shift controller to the motor controller will be zeroed, the control instrument will alarm and the hazard warning lights will be automatically turned on to alert the driver and vehicles behind. The vehicle can then coast to a safe area for maintenance of the electric drive axle shift mechanism.

[0092] If the vehicle speed is less than or equal to the preset threshold V4, the vehicle will issue a pullover maintenance reminder, prompting the driver to immediately pull over for maintenance of the electric drive axle shift mechanism. In some embodiments, the preset threshold V4 is the same as the preset threshold V1 speed.

[0093] This embodiment achieves full coverage of fault handling through a complete closed loop, from fault detection and attempted repair to repair failure and fault reporting and maintenance. This avoids the inefficiency or safety hazards caused by a one-size-fits-all approach, reduces the risk of mechanical damage, and creates a time window and safety boundary for the recovery of the faulty bridge by limiting the speed, which can improve the robustness and reliability of the system.

[0094] Example 2

[0095] This embodiment provides a fault diagnosis system for gear shifting stall in the electric drive axle of a new energy commercial vehicle. The fault diagnosis system for gear shifting stall in the electric drive axle of a new energy commercial vehicle in this embodiment includes:

[0096] The receiving module is used to receive the driver's shift request command to the shift mechanism;

[0097] The acquisition module is used to acquire the duty cycle, duration and current of the H-bridge drive output by the shift controller during the shift process, as well as the voltage fed back by the position sensor of the shift mechanism.

[0098] The comparison and judgment module is used to compare the duty cycle, duration, current value of the H-bridge drive and the voltage change value fed back by the shift mechanism position sensor within a preset time threshold with their preset thresholds, and to determine whether the shift mechanism has a stall fault based on the comparison results.

[0099] The control module is used to execute repair control commands based on shift request commands and judgment results.

[0100] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present disclosure / the present invention, and these improvements and modifications should also be considered within the scope of protection of the present disclosure / the present invention.

Claims

1. A method for diagnosing gear shifting stall faults in the electric drive axle of a new energy commercial vehicle, characterized in that, Including the following steps: In response to receiving a shift request command from the driver, the shift mechanism is controlled to shift gears; The duty cycle, duration, and current of the H-bridge drive output by the shift controller during the shift process, as well as the voltage fed back by the shift mechanism position sensor, are obtained. The duty cycle, duration, current value of the H-bridge drive, and the voltage change value fed back by the position sensor of the shift mechanism within a preset time threshold are compared with their preset thresholds, and the shift mechanism is judged to have a stall fault based on the comparison results. If the shifting mechanism experiences a stall fault, a repair control command is executed.

2. The method for diagnosing gear shifting stall faults in the electric drive axle of new energy commercial vehicles according to claim 1, characterized in that, The shifting mechanism is considered to have a stall fault when the following conditions are met simultaneously: The duty cycle is greater than the preset threshold PWM1; The duration is greater than a preset threshold T1; The current is greater than a preset threshold I1; The voltage change value fed back by the position sensor of the shift mechanism within the preset time threshold T2 is less than the preset threshold U1.

3. The method for diagnosing stall faults in the electric drive axle of new energy commercial vehicles according to claim 1, characterized in that, The shift control commands include a disengagement request command or an engagement request command. If a stall fault occurs in the shift mechanism, a repair control command is executed, including: When the shift request command is a disengagement request command, and it is determined that a stall fault has occurred in the shift mechanism, the first repair control command is executed; When the shift request command is an upshift request command and it is determined that the shift mechanism has a stall fault, the second repair control command is executed.

4. The method for diagnosing stall faults in the electric drive axle of new energy commercial vehicles according to claim 3, characterized in that, The first repair control command includes: Control the shifting mechanism to reverse drive and disengage the gear, and record the number of times the shifting mechanism reverses drive; Determine whether the gear shifting mechanism has switched to neutral; If so, continue executing the gear shifting process, and clear the gear shift stall fault flag and the number of reverse drive cycles of the gear shifting mechanism to zero; If not, determine whether the number of reverse drives of the shift mechanism is greater than the preset threshold N1. If the number of reverse drives of the shift mechanism is greater than the preset threshold N1, control the shift mechanism to switch to the previous target gear, count the number of times the shift mechanism fails to disengage, and limit the current vehicle speed to the maximum vehicle speed threshold V1 of the lower gear in the middle and rear axles.

5. The method for diagnosing stall faults in the electric drive axle of new energy commercial vehicles according to claim 4, characterized in that, After limiting the vehicle speed to the maximum speed threshold V1 of the lower gear in the middle and rear axle, within a preset time threshold T3, in response to receiving the driver's request to disengage the gear shifting mechanism, the gear shifting mechanism is disengaged. Determine whether the gear shifting mechanism has switched to neutral; If so, continue the gear shifting process, reset the number of failed gear disengagement attempts of the gear shifting mechanism to zero, and remove the vehicle speed limit; If not, execute the first repair control command; When executing the first repair instruction, if the number of reverse drives of the shift mechanism is greater than the preset threshold N1, a shift failure is recorded once; When the number of failed gear shifts within the preset time threshold T3 exceeds the preset threshold N2, the first safety control command is executed based on the current vehicle speed.

6. The method for diagnosing stall faults in the electric drive axle of new energy commercial vehicles according to claim 5, characterized in that, Execute the first safety control command based on the current vehicle speed, including: If the current vehicle speed is greater than the preset threshold V2, the torque sent by the shift controller to the motor controller is cleared to zero, the instrument alarm is triggered, and the hazard warning lights are automatically turned on. If the vehicle speed is less than or equal to the set threshold V2, control the vehicle to issue a reminder to pull over for maintenance.

7. The method for diagnosing stall faults in the electric drive axle of new energy commercial vehicles according to claim 2, characterized in that, The second repair control command includes: The shift controller controls the shift mechanism to return to neutral and engage a gear. After each engagement, the number of times the shift mechanism returns to neutral is recorded, and it is determined whether the shift mechanism has switched to the target gear. If so, continue executing the gear shifting process and clear the gear shift stall fault flag and the number of times the gear shifting mechanism has returned to zero; If not, determine whether the number of times the shift mechanism returns to neutral is greater than the set threshold N3. When the number of times the shift mechanism returns to neutral is greater than the set threshold N3, the shift controller controls the shift mechanism to switch to the previous target gear and counts the number of times the shift mechanism fails to engage gear. At the same time, the vehicle speed is limited to the maximum vehicle speed threshold V3 of the lower gear of the middle and rear axles.

8. The method for diagnosing stall faults in the electric drive axle of new energy commercial vehicles according to claim 7, characterized in that, After limiting the vehicle speed to the maximum speed threshold V3 of the lower gear in the middle and rear axles, within a preset time threshold T4, in response to receiving the driver's request for the shift mechanism to shift gears, the shift mechanism is shifted to the next gear, and it is determined whether the shift mechanism has switched to the target gear. If so, the number of failed gear shifts for the gear shifting mechanism is reset to zero, and the vehicle speed limit is lifted; If not, execute the second repair control command; When executing the second repair control command, if the number of times the shifting mechanism returns to neutral exceeds the set threshold N3, a shifting failure is recorded once; When the number of failed gear shifts exceeds the preset threshold N4, the first safety control command is executed based on the current vehicle speed.

9. The method for diagnosing stall faults in the electric drive axle of new energy commercial vehicles according to claim 8, characterized in that, Execute the second safety control command based on the current vehicle speed, including: If the current vehicle speed is greater than the preset threshold V4, the torque sent by the shift controller to the motor controller is cleared to zero, the instrument alarm is triggered, and the hazard warning lights are automatically turned on. If the vehicle speed is less than or equal to the set threshold V4, control the vehicle to issue a reminder to pull over for maintenance.

10. A fault diagnosis system for gear shifting stall in an electric drive axle of a new energy commercial vehicle, characterized in that, include: The receiving module is used to receive the driver's shift request command to the shift mechanism and control the shift mechanism to perform shifting. The acquisition module is used to acquire the duty cycle, duration and current of the H-bridge drive output by the shift controller during the shift process, as well as the voltage fed back by the position sensor of the shift mechanism. The comparison and judgment module is used to compare the duty cycle, duration, current value of the H-bridge drive and the voltage change value fed back by the shift mechanism position sensor within a preset time threshold with their preset thresholds, and to determine whether the shift mechanism has a stall fault based on the comparison results. A control module is provided to execute repair control commands when a stall fault occurs in the shifting mechanism.

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