CN115750778A - Gear-shifting control fault diagnosis system and method for multi-gear reduction box of vehicle - Google Patents

Abstract

The invention discloses a gear-shifting control fault diagnosis system and method for a multi-gear reduction box of a vehicle, which comprises a pre-gear-shifting fault diagnosis module, a during-gear-shifting fault diagnosis module and a post-gear-shifting fault diagnosis module; the fault diagnosis method can quickly and effectively identify the clamping stagnation of the gear shifting motor, the overtime of the gear shifting motor and the overlarge rotating speed of two ends of the synchronizer in the gear shifting process; and simultaneously, the running state of an external driving motor is monitored in real time. The fault diagnosis method comprises the steps that after hundreds of thousands of gear shifting endurance tests on a rack, gear shifting is forbidden or returned to an original position to enter or retreat again according to a corresponding fault protection mechanism when a fault occurs; when the gear shifting function is met, the hardware structure can be well protected, and when the synchronous speed difference is triggered to be overlarge in the actual measurement gear shifting and gear shifting process, the vehicle enters a Retry protection strategy, namely returns to the neutral gear and enters the gear again. The gear shifting quality is guaranteed, and meanwhile hardware is fully protected from being damaged.

Description

Gear-shifting control fault diagnosis system and method for multi-gear reduction box of vehicle

Technical Field

The invention belongs to the technical field of gear shift control fault diagnosis, and particularly relates to a gear shift control fault diagnosis system and method for a multi-gear reduction box of a vehicle.

Background

Most of the existing new energy electric drive transmission systems adopt single-stage reduction products, and have the advantages of no control, pure mechanical transmission, simple structure and lower cost; the power assembly product has higher requirements on the driving motor; the high-efficiency working range of the motor is limited, and the requirements of dynamic property, economy and the like cannot be considered; high speed acceleration is not strong; high-speed NVH noise is large, and the comfort of drivers and passengers is influenced. Therefore, the multi-gear of the pure electric product is the development direction in the future, and meanwhile, the fault detection method corresponding to the multi-gear control system is particularly important for safe driving. When the gear shifting mechanism has a problem, a corresponding fault processing mode needs to be adopted according to the fault type, so that the vehicle can normally complete gear shifting, normal driving and safe parking.

Disclosure of Invention

The invention aims to develop a method and a system for diagnosing gear shifting control faults of a multi-gear reduction box, which can monitor whether a transmission system has abnormal conditions before gear shifting action, in the gear shifting action executing process and after the gear shifting execution is finished in real time, and adopt a correct coping mode aiming at the abnormal conditions so that a vehicle can normally finish gear shifting or can normally drive or adopt a mechanism such as safe parking and the like, thereby ensuring the comfortable safety of the vehicle and drivers and passengers. And setting and recovering the fault are executed according to the corresponding fault triggering condition and the fault recovery condition.

The gear-shifting control fault diagnosis system of the multi-gear reduction box for achieving one of the purposes of the invention comprises a before-gear-shifting fault diagnosis module, an in-gear-shifting fault diagnosis module and an after-gear-shifting fault diagnosis module;

the pre-gear-shifting fault diagnosis module is used for diagnosing whether the temperature and/or voltage signals are abnormal or not, and reporting temperature and/or voltage faults if the temperature and/or voltage signals are abnormal; the temperature abnormity means that the current temperature needs to be in a temperature range of stable working conditions of the gear shifting motor and the control board, and if the current temperature is not in the temperature range, the temperature abnormity is detected; the voltage abnormity means that the voltage needs to be in a normal set range, if the voltage is not in the set range, the voltage abnormity is abnormal, and faults such as electric appliance fault short circuit, open circuit and open circuit can be generated due to the voltage abnormity;

the gear shifting fault diagnosis module is used for diagnosing whether a vehicle generates a fault related to a gear shifting process in the gear shifting and/or neutral gear shifting and/or gear shifting process, and if so, reporting a corresponding fault code; the shift process related fault includes: abnormal fault of speed regulation, mismatching fault of torque, overlarge fault of synchronous speed difference, unexpected static fault of a gear shifting hub, overcurrent fault of a gear shifting motor, overlarge fault of deviation of a gear shifting position, gear entering and/or gear disengaging and/or overtime of gear shifting;

the gear-off refers to a dynamic process of the vehicle from gear position to neutral gear; the gear-in refers to a movement process of the vehicle from a neutral gear position to a gear-in position; the shift hub is unexpectedly static, namely, a large driving force is given to the motor, but the actual shift hub rotates too slowly to reach the driving force, and the shift hub is close to a static state.

The fault diagnosis module after gear shifting is used for diagnosing whether the vehicle generates faults related to gear shifting after gear shifting, and if yes, corresponding fault codes are reported.

Further, the pre-shift fault diagnosis module further comprises a shift hub position verification module for verifying whether the current angle and the physical position are matched according to the self-learning position of the shift hub; if not, reporting a shift hub position unreliable fault; the self-learning position, namely the corresponding relation between the actual physical structure physical position of the gear shifting hub and the angle of the gear shifting hub is obtained through self-learning of the gear shifting hub, and if the gear shifting hub rotates to the bottom dead center, the gear shifting hub corresponds to the 0-degree reference.

Further, the during-gear-shifting fault diagnosis module comprises an in-gear fault diagnosis module used for verifying whether the torque of the driving motor is 0, and reporting the unmatched fault of the out-of-gear torque if the torque of the driving motor is not 0 all the time within the set time length;

further, the shift-in-gear fault diagnosis module comprises an out-of-gear fault diagnosis module for monitoring whether an out-of-gear process exists: shift out state timeout, shift hub unexpected standstill and current overcurrent; if the vehicle is in any state, the vehicle is returned to the gear position, and the gear-disengaging action is executed again; and if the total duration of the gear-out process is overtime, the vehicle reports the gear-out failure fault.

Further, the fault diagnosis module during gear shifting comprises a neutral fault diagnosis module, and is used for carrying out speed regulation on the driving motor according to speed ratio change in the neutral process, and reporting a fault with abnormal speed regulation if the target rotating speed is not reached within a set time length.

Further, the shift fault diagnosis module comprises a shift fault diagnosis module for monitoring whether a shift process exists: the shift control method comprises the following steps that a shift state is overtime, a shift hub is unexpectedly static, a synchronous speed difference is larger than a set speed difference value, and the current of a shift motor is overcurrent; if the vehicle is in any state, the vehicle is retreated to a neutral position, and the gear shifting action is executed again; and if the total duration of the gear entering process is overtime, reporting a gear entering failure fault by the vehicle. The set speed difference value is determined according to the inherent characteristics of the synchronizer parts and the abrasion condition of the durability test of the synchronizer parts; monitoring whether the current gear shifting hub motor current is larger than a calibration threshold (such as 80A) within a certain time (such as 0.1 s) when the motor current is overcurrent;

further, the during-shifting fault diagnosis module comprises a driving dead center position detection module, and is used for acquiring a dead center position angle of the shifting hub when the shifting hub is in a gear position or a neutral position in the driving process; and the gear shifting hub dead point position angle is used for comparing with a dead point position learned in the gear shifting hub position verification module, and if the positions are inconsistent, reporting a position unreliable fault.

Further, the post-shift fault diagnosis module includes a motor position monitoring module for continuously monitoring whether the motor position is abnormal, where the motor position is abnormal: no driving duty ratio is available after gear shifting is finished; if the change of the position of the gear shifting hub motor exceeds 3 degrees in two continuous time periods, the motor position is abnormal, and if the change of the position of the gear shifting hub motor exceeds 3 degrees, a position loss fault is reported.

Further, the fault diagnosis module after gear shifting comprises a rotating speed signal monitoring module which is used for continuously monitoring whether the rotating speed of the motor and the rotating speed of the output shaft jump abnormally or not, and reporting the position loss fault if the rotating speed of the motor and the rotating speed of the output shaft jump abnormally.

The invention also provides a method for diagnosing the gear shifting control fault of the multi-gear reduction box, which comprises the following steps:

before gear shifting: identifying the temperature and/or voltage signal, reporting the abnormal fault of the temperature and/or voltage signal if the signal is abnormal, and entering a fault mode;

during gear shifting: detecting whether the torque of the driving motor is 0 or not in the gear position; if the time length is not 0 all the time within the set time length, the vehicle enters a failure mode; otherwise, entering a gear-disengaging process;

monitoring whether the motor has overtime gear shifting state, unexpected rest of a gear shifting hub and overcurrent of current in the gear shifting process or not in the gear shifting process, and if the motor is not abnormal, the motor is successfully shifted to a neutral gear; if any abnormity occurs, returning to the original gear to execute the gear-disengaging action again; when the gear-off is carried out for multiple times but the gear-off does not reach the target position, the vehicle reports the failure fault of gear-off and enters a fault mode;

in the neutral gear process, judging whether the speed regulation of the motor is abnormal, if the speed regulation does not reach the target rotating speed within the set time length, reporting a speed regulation abnormal fault and entering a fault mode; the gear keeps neutral at the moment;

monitoring whether a gear shifting state of a gear shifting motor is overtime, an unexpected static state of a gear shifting hub, whether the gear shifting motor is over-current and whether a synchronous speed difference is overlarge in the gear shifting process, and if any abnormal condition occurs, returning to a neutral position and re-shifting; and if the total duration of the gear entering process is overtime, reporting a gear entering failure fault by the vehicle and entering a fault mode.

After gear shifting: judging whether the rotating speed of the motor and the rotating speed of the output shaft are abnormal or not, and if so, enabling the vehicle to enter a fault mode;

further, before gear shifting, if the temperature and voltage signals are normal, the gear shifting hub enters a self-learning position verification mode, and if the gear shifting hub fails to pass multiple times of verification, a corresponding fault code is reported and the gear shifting hub enters a fault mode. The self-learning position, namely the corresponding relation between the physical position and the angle of the actual physical structure is obtained by the self-learning self-checking of the gear shifting hub, and if the gear shifting hub rotates to the bottom dead center, the corresponding relation corresponds to the 0-degree reference; if the current angle and the physical position are correct corresponding relations, the verification is passed, otherwise, the verification is not passed.

Furthermore, in the gear position or neutral position of the vehicle in the gear shifting process, the angle of the dead point position of the gear shifting hub is obtained, the dead point position is compared with the dead point position obtained by self-learning of the gear shifting hub, if the dead point position exceeds a specified threshold value, the vehicle reports an unreliable fault code of the position, and enters a diagnosis mode to request for self-learning again.

The method for acquiring the dead point position angle of the gear shifting hub comprises the following steps: when the gear shifting hub is located at a gear position or a neutral position in the driving process, the gear shifting motor is triggered to drive the gear shifting hub to touch upper and lower dead points of the shell, and a gear shifting hub dead point position angle is obtained.

Further, the failure mode comprises the steps of carrying out speed limit and torque limit requests on the PDCU of the whole vehicle controller.

The invention also provides a method for diagnosing the gear shifting control fault of the multi-gear reduction box, which comprises the following steps:

before gear shifting: identifying the temperature and/or voltage signal, reporting the abnormal fault of the temperature and/or voltage signal if the signal is abnormal, and entering a fault mode;

in the gear shifting: detecting whether the torque of the driving motor is 0 or not in the gear position; if the time length is not 0 all the time within the set time length, the vehicle enters a failure mode; otherwise, entering a gear-disengaging process;

monitoring whether faults related to gear disengagement exist in the motor or not in the gear disengaging process, and if the faults do not occur, the gear disengaging is successfully carried out to enter a neutral gear; if any fault occurs, returning to the original gear to execute the gear-disengaging action again; when the gear-off is carried out for multiple times but the gear-off does not reach the target position, the vehicle reports the failure fault of gear-off and enters a fault mode; the faults related to gear disengagement comprise overtime of a gear shifting state, unexpected rest of a gear shifting hub and overcurrent of current during gear disengagement;

in the neutral gear process, judging whether the speed regulation of the motor is abnormal, if the speed regulation does not reach the target rotating speed within the set time length, reporting a speed regulation abnormal fault and entering a fault mode; the gear keeps neutral at the moment;

monitoring whether a fault related to gear shifting exists in a gear shifting motor in the gear shifting process, and if the fault occurs, returning to a neutral position for gear shifting again; if the total duration of the gear entering process is overtime, reporting a gear entering failure fault by the vehicle and entering a fault mode; the faults related to gear entering comprise overtime of a gear shifting state, unexpected static of a gear shifting hub, overcurrent of a gear shifting motor and overlarge synchronous speed difference;

after gear shifting: judging whether the rotating speed of the motor and the rotating speed of the output shaft are abnormal, if so, reporting a position loss fault by the vehicle and entering a fault mode;

the fault mode comprises the steps of carrying out speed limit and torque limit requests on the PDCU of the whole vehicle controller.

Has the advantages that:

the fault diagnosis method can quickly and effectively identify the clamping stagnation (such as over-slow rotating speed) of the gear shifting motor, the overtime (overtime shifting state) of the gear shifting motor and the overlarge rotating speed (in the synchronization process) at the two ends of the synchronizer in the gear shifting process. And simultaneously, the running state of an external driving motor is monitored in real time. The fault diagnosis method comprises the steps that after hundreds of thousands of gear shifting endurance tests on a rack, gear shifting is forbidden or returned to an original position to enter or retreat again according to a corresponding fault protection mechanism when a fault occurs; the gear shift control method has the advantages that the effect is good, the logic is clear, the gear shift function is met, meanwhile, the hardware structure can be well protected, and the logic control process that the vehicle enters a Retry protection strategy when the synchronous speed difference is triggered to be too large in the actual measurement gear shift process, namely, the vehicle returns to the neutral gear and enters the gear again is achieved. The gear shifting quality is guaranteed, and meanwhile hardware is fully protected from being damaged.

Drawings

FIG. 1 is a block diagram of the system of the present invention;

FIG. 2 is a schematic flow chart of an embodiment of the method of the present invention prior to a shift event;

FIG. 3 is a schematic flow chart of a shift action in an embodiment of the method of the present invention;

fig. 4 is a schematic flow chart of the method according to the invention after a gear change.

FIG. 5 is a schematic representation of the method of the present invention in which a Retry protection strategy is triggered during a shift into gear with an excessive differential synchronization.

Detailed Description

The following detailed description is provided to explain the claims of the present invention so that those skilled in the art may understand the claims. The scope of the invention is not limited to the following specific implementation configurations. It is intended that the scope of the invention be determined by those skilled in the art from the following detailed description, which includes claims that are directed to this invention.

The application embodiment also provides an embodiment of a gear shifting control fault diagnosis system of a multi-gear reduction box, which comprises a before-gear-shifting fault diagnosis module, a during-gear-shifting fault diagnosis module and a after-gear-shifting fault diagnosis module as shown in fig. 1;

and the before-gear-shifting fault diagnosis module is used for diagnosing whether the temperature and/or voltage signals are abnormal or not, and reporting the temperature and/or voltage faults if the temperature and/or voltage signals are abnormal.

In another embodiment, the pre-shift fault diagnostic module further comprises a shift hub position verification module for verifying whether the current angle and physical position match based on the shift hub self-learned position; and if not, reporting a shift hub position unreliable fault.

And the in-gear-shifting fault diagnosis module is used for diagnosing whether the vehicle generates faults related to gear shifting in the gear shifting process and/or the neutral gear process and/or the gear shifting process, and if so, reporting corresponding fault codes.

In another embodiment, the shift fault diagnosis module comprises a driving dead center position detection module, which is used for acquiring a dead center position angle of a shift hub when the shift hub is in a gear position or a neutral position in the driving process; the gear shifting hub dead point position angle is used for comparing with a dead point position learned in the gear shifting hub position checking module, and if the positions are inconsistent, the position is reported to be an unreliable fault

In another embodiment, the shift-in-gear fault diagnosis module includes an in-gear fault diagnosis module for verifying whether the torque of the driving motor is 0, and reporting the out-of-gear torque mismatch fault if the torque of the driving motor is not 0 for a set time period.

In another embodiment, the shift in fault diagnostic module includes an out-of-gear fault diagnostic module for monitoring whether an out-of-gear condition exists: an out-of-gear state timeout, shift hub unexpected rest and current over-current; if the vehicle is in any one of the states, the vehicle is retreated to the gear position, and the gear-disengaging action is executed again; and if the total duration of the gear-out process is overtime, the vehicle reports the gear-out failure fault.

In another embodiment, the fault diagnosis module during gear shifting comprises a neutral fault diagnosis module, which is used for carrying out speed regulation on the driving motor according to speed ratio change in the neutral process, and reporting a fault with abnormal speed regulation if the target rotating speed is not reached within a set time length.

In another embodiment, the shift in fault diagnostic module includes an upshift fault diagnostic module for monitoring whether there is: the shift-in state is overtime, the shift hub is unexpectedly static, the synchronous speed difference is greater than a set value, and the current of the shift motor is overcurrent; if the vehicle is in any state, the vehicle is retreated to a neutral position, and the gear shifting action is executed again; and if the total duration of the gear entering process is overtime, reporting a gear entering failure fault by the vehicle.

The fault diagnosis module after gear shifting is used for diagnosing whether the vehicle generates faults related to gear shifting after gear shifting, and if yes, reporting corresponding fault codes.

In another embodiment, the post-shift fault diagnosis module includes a motor position monitoring module configured to continuously monitor whether a motor position is abnormal, and report a position loss fault if the motor position is abnormal.

In another embodiment, the fault diagnosis module after gear shifting comprises a rotating speed signal monitoring module which is used for continuously monitoring whether the rotating speed of the motor and the rotating speed of the output shaft jump abnormally or not, and reporting the position loss fault if the rotating speed of the motor and the rotating speed of the output shaft jump abnormally.

An embodiment of the method of the present invention is described below with reference to fig. 2-5.

Before the gear shifting starts, as shown in fig. 2, the MTCU controller acquires a gear shifting motor voltage signal and recognizes a temperature measured by an oil temperature sensor;

judging whether the motor has faults such as electrical fault short circuit, open circuit and the like according to the voltage range of the gear shifting motor, wherein the voltage range of the gear shifting motor is usually [9V,16V ];

comparing the current temperature with the temperature range of the stable working conditions of the gear shifting motor and the control plate, wherein the range is usually between the range of minus 40 ℃ and 120 ℃;

if the voltage of the gear shifting motor is not in the range or the temperature is not in the range, the vehicle reports a corresponding fault code and enters a fault mode, and the speed limit and torque limit request is carried out on the PDCU of the whole vehicle controller. Otherwise, the vehicle enters the self-learning position verification of the gear shifting hub; the self-learning position, namely the corresponding relation between the physical position and the angle of the actual physical structure is obtained by the self-learning self-checking of the gear shifting hub, and if the gear shifting hub rotates to the bottom dead center, the corresponding relation corresponds to the 0-degree reference; if the current angle and the physical position are in correct corresponding relation, the checking is passed, and at the moment, the position of the gear shifting hub is credible, a PDCU instruction is waited, and the gear shifting process is started; if the test fails, repeating the self-learning process, if the self-learning fails for multiple times, reporting a corresponding fault code and entering a fault mode, and carrying out speed limit and torque limit requests on the PDCU of the whole vehicle controller. Otherwise, waiting for a PDCU instruction and entering a gear shifting process.

As shown in fig. 3, the gear shifting process is performed, whether the torque of the driving motor is 0 or not is checked at the gear position, if the torque is not 0 all the time within a set time period, a fault code with unmatched gear-disengaging torque is reported, the vehicle enters a fault mode, and a speed-limiting and torque-limiting request is performed on a PDCU of the whole vehicle controller; and entering a gear-disengaging process if the torque is proper.

Several conditions are monitored during the gear-out process:

1. the shift state is overtime;

2. the shift hub is not expected to be stationary;

3. overcurrent of current in the gear disengaging process;

if the vehicle is in any one of the states, a Retry strategy is entered, namely, the vehicle is returned to the gear position, and the gear-out action is executed again. If the total duration of the gear-out process is overtime, the vehicle reports a fault code corresponding to the gear-out failure, the vehicle enters a fault mode, and the speed limit and torque limit request is carried out on the PDCU of the whole vehicle controller. Otherwise, the gear is shifted into the neutral gear successfully.

In the neutral gear process, the driving motor is driven to regulate speed according to the speed ratio change condition, if the target rotating speed is not reached for a long time, a fault code abnormal in speed regulation is reported, the neutral gear is kept, the vehicle enters a fault mode, and speed limit and torque limit requests are carried out on a PDCU (packet data processing unit). Otherwise, the neutral gear is adjusted normally, and the gear entering process is started.

During the gear-in process, the following states are monitored:

1. the shift state is overtime;

2. the shift hub is not expected to be stationary;

3. the synchronous speed difference is too large;

4. overcurrent of a gear shifting motor;

if the vehicle meets any one of the conditions, a Retry strategy is entered, namely, the vehicle is returned to a neutral position and enters the gear again. If the total duration of the gear entering process is overtime, reporting a fault code of gear entering failure by the vehicle, enabling the vehicle to enter a fault mode, and carrying out speed limit and torque limit requests on a PDCU of the whole vehicle controller; otherwise, the gear is successfully shifted into the gear position.

Preferably, the vehicle is in a gear position or a neutral position in the gear shifting process, the running gear stop position is triggered to be checked, specifically, when the gear shifting hub is in the gear position or the neutral position in the driving process, the gear shifting motor is triggered to drive the gear shifting hub to touch upper and lower stop points of the shell to obtain the stop point position angle of the gear shifting hub, the running gear stop position is compared with the self-learning stop point position, if a specified threshold value is exceeded (if the positive and negative deviation is greater than 3 degrees), the vehicle reports an unreliable fault code of the position, and enters a diagnosis mode to request for self-learning again.

After gear shifting is finished, as shown in fig. 4, an actual speed ratio is obtained according to the rotating speed of the driving motor and the rotating speed of the output shaft, the vehicle continuously monitors the actual speed ratio and compares the actual speed ratio with a theoretical speed ratio, if the difference value is overlarge, the vehicle reports a fault code with unreliable speed ratio and enters a fault mode, and a speed-limiting and torque-limiting request is made on the PDCU of the whole vehicle controller. Fig. 5 shows a logic control process of triggering a Retry protection strategy when the synchronous speed difference is too large, returning to the neutral gear, and re-entering the gear in the actually measured gear shifting and gear entering process. The gear shifting quality is guaranteed, and meanwhile hardware is fully protected from being damaged.

And after gear shifting is finished, the duty ratio output is 0, whether the motor position and the rotating speed signal are abnormally jumped or not is continuously monitored, if the position and the rotating speed signal are abnormally jumped, the vehicle reports a position loss fault code and enters a fault mode, and a speed limit and torque limit request is carried out on the PDCU of the whole vehicle controller.

It should be understood that, the sequence numbers of the steps in the foregoing embodiments do not imply an execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

Details not described in this specification are within the skill of the art that are well known to those skilled in the art.

Claims (10)

1. A multi-gear reduction box gear-shifting control fault diagnosis system is characterized by comprising:

the system comprises a fault diagnosis module before gear shifting, a fault diagnosis module during gear shifting and a fault diagnosis module after gear shifting;

the before-gear-shifting fault diagnosis module is used for diagnosing whether the temperature and/or voltage signals are abnormal or not, and reporting temperature and/or voltage faults if the temperature and/or voltage signals are abnormal;

the gear shifting fault diagnosis module is used for diagnosing whether a vehicle generates faults related to a gear shifting process in the gear shifting process and/or the neutral gear shifting process and/or the gear shifting process, and if yes, reporting corresponding fault codes;

the fault diagnosis module after gear shifting is used for diagnosing whether the vehicle generates faults related to gear shifting after gear shifting, and if yes, reporting corresponding fault codes.

2. The multi-speed reduction gearbox shift control fault diagnosis system of claim 1, wherein the pre-shift fault diagnosis module further comprises a shift hub position verification module for verifying whether the current angle and physical position match based on the shift hub self-learned position; and if not, reporting an unreliable fault of the shift hub position.

3. The gear shifting control fault diagnosis system of a multi-gear reduction box according to claim 2, wherein the gear shifting fault diagnosis module comprises a driving dead center position detection module for acquiring a dead center position angle of a gear shifting hub when the gear shifting hub is in a gear position or a neutral position during driving; and the gear shifting hub dead point position angle is used for comparing with the dead point position learned in the gear shifting hub position checking module, and if the positions are inconsistent, reporting a position unreliable fault.

4. The gear shifting control fault diagnosis system of the multi-gear reduction box according to claim 1, wherein the gear shifting fault diagnosis module comprises a gear shifting fault diagnosis module for verifying whether the torque of the driving motor is 0, and reporting the unmatched gear shifting torque fault if the torque is not 0 for a set time period.

5. A multiple speed reduction gearbox shift control diagnostic trouble system according to claim 1 wherein said in-shift fault diagnostic module includes an out-of-gear fault diagnostic module for monitoring whether there is: shift out state timeout, shift hub unexpected standstill and current overcurrent; if the vehicle is in any state, the vehicle is returned to the gear position, and the gear-disengaging action is executed again; and if the total duration of the gear-out process is overtime, the vehicle reports the gear-out failure fault.

6. The gear-shifting control fault diagnosis system of a multi-gear reduction box according to claim 1, wherein the fault diagnosis module during gear shifting comprises a neutral fault diagnosis module, and is used for carrying out speed regulation on the driving motor according to speed ratio change in the neutral process, and reporting a fault with abnormal speed regulation if a target rotating speed is not reached within a set time length.

7. The shift control fault diagnostic system for a multi-speed reduction gearbox according to claim 1, wherein said in-shift fault diagnostic module includes an in-shift fault diagnostic module for monitoring whether there is: the shift control method comprises the following steps of overtime shift state, unexpected rest of a shift hub, synchronous speed difference larger than a set value and overcurrent of shift motor current; if the vehicle is in any state, the vehicle is retreated to a neutral position, and the gear shifting action is executed again; and if the total duration of the gear entering process is overtime, reporting a gear entering failure fault by the vehicle.

8. The shift control fault diagnosis system of a multi-speed reduction gearbox according to claim 1, wherein said post-shift fault diagnosis module comprises a motor position monitoring module for continuously monitoring whether the motor position is abnormal, and reporting a position loss fault if abnormal.

9. The gear shifting control fault diagnosis system of the multi-gear reduction box according to claim 1, wherein the after-gear shifting fault diagnosis module comprises a rotation speed signal monitoring module for continuously monitoring whether the rotation speed of the motor and the rotation speed of the output shaft jump abnormally or not, and reporting a position loss fault if the abnormal.

10. A multi-gear reduction box gear-shifting control fault diagnosis method is characterized by comprising the following steps:

before gear shifting: identifying the temperature and/or voltage signal, reporting the abnormal fault of the temperature and/or voltage signal if the signal is abnormal, and entering a fault mode;

during gear shifting: detecting whether the torque of the driving motor is 0 or not in the gear position; if the time length is not 0 all the time within the set time length, the vehicle enters a failure mode; otherwise, entering a gear-disengaging process;

monitoring whether faults related to gear disengagement exist in the motor or not in the gear disengaging process, and if the faults do not occur, the gear disengaging is successfully carried out to enter a neutral gear; if any fault occurs, returning to the original gear to execute the gear-disengaging action again; when the gear-off is carried out for multiple times but the gear-off does not reach the target position, the vehicle reports the failure fault of gear-off and enters a fault mode;

in the neutral gear process, judging whether the speed regulation of the motor is abnormal, if the speed regulation does not reach the target rotating speed within the set time length, reporting a speed regulation abnormal fault and entering a fault mode; the gear keeps neutral at the moment;

monitoring whether faults related to gear entering exist in the gear entering motor or not in the gear entering process, and if any fault occurs, returning to a neutral position for gear entering again; if the total duration of the gear entering process is overtime, reporting a gear entering failure fault by the vehicle and entering a fault mode;

after gear shifting: judging whether the rotating speed of the motor and the rotating speed of the output shaft are abnormal, if so, reporting a position loss fault by the vehicle and entering a fault mode;

the fault mode comprises the steps of carrying out speed limit and torque limit requests on the PDCU of the whole vehicle controller.

Images