Transfer case jam detection method and device, transfer case jam processing method and device, transfer case, automobile

Abstract

The invention relates to the field of automobile manufacturing. In order to solve the problem that the detection method of the transfer case jamming phenomenon in the prior art is mostly disassembly detection after the system is abnormal, and the driver cannot be warned before the fault becomes serious, the technical solution provided detects the state of the transfer case in real time during its operation, identifies the jamming and handles it in time, reduces the more serious failure of the transfer case, and improves the reliability and safety of the system. It includes: learning the zero position of the transfer case motor when the clutch is completely disengaged; recording and updating the zero position, and recording the number of jams; learning the Kp position of the transfer case motor when the clutch is transmitting torque stably; recording and updating the Kp position, and subtracting the zero position to obtain the relative position; judging the relative position and the preset minimum limit value. If the relative position is less than the preset minimum limit value, the transfer case jam result is output. It is suitable for application in automobile transfer case manufacturing and research.

Description

Technical Field

[0001] The invention relates to the field of automobile manufacturing, and specifically to the field of transfer case manufacturing. Background Art

[0002] The application of motor-driven timely four-wheel drive transfer cases is becoming more and more widespread. It is a common drive form to use an actuator motor plus a mechanical transmission mechanism to drive the compression and separation of the transfer case clutch to achieve torque distribution between the front and rear axles of the vehicle. For this system, the mechanical transmission mechanism plays the role of reducing speed and increasing torque, and converting the rotation of the actuator motor into the axial movement of the clutch, which is the premise for the function of the transfer case. If the mechanical transmission system is stuck, it will directly affect the torque transmission function of the transfer case and even cause the transfer case clutch to burn out.

[0003] At the same time, due to cost and space constraints, transfer case products do not have a jam detection device or clutch pressure sensor, and cannot be judged by equipment or sensor information. The current detection method is mostly to disassemble the machine after the system is abnormal, which cannot warn the driver before the fault becomes serious, so as to deal with the fault as soon as possible.

[0004] Therefore, there is an urgent need for a mechanical transmission mechanism jam detection and processing method to solve the above problems. Summary of the invention

[0005] In order to solve the problem that the detection method of the transfer case jamming phenomenon in the prior art is mostly to disassemble the machine for detection after the system is abnormal, and it is impossible to warn the driver before the fault becomes serious so as to deal with the fault as soon as possible, the technical solution provided by the present invention detects the state of the transfer case in real time during its operation, identifies the jamming and handles it in time, reduces the more serious failure of the transfer case, and improves the reliability and safety of the system. Specifically:

[0006] A transfer case jam detection method is used to detect a transfer case jam phenomenon, the method comprising:

[0007] Zero position self-learning steps: learning the motor zero position of the transfer case when the clutch is completely disengaged;

[0008] Recording zero position step: recording and updating the zero position, and recording the number of stuck times;

[0009] Kp position learning steps: learning the motor Kp position of the transfer case when the clutch is transmitting torque stably;

[0010] Recording Kp position learning steps: recording and updating the Kp position, and subtracting the zero position to obtain the relative position;

[0011] Judgment step: judge the size of the relative position and the preset minimum limit. If the relative position is greater than the preset minimum limit, no information is output and the transfer case continues to work normally. If the relative position is less than the preset minimum limit, the transfer case jam result is output.

[0012] Furthermore, the method further comprises:

[0013] Real-time detection step: when the transfer case stuck result is not output in the judgment step, if the actual motor position of the transfer case deviates from the preset expected motor position by more than a preset distance and time, a suspected transfer case stuck result is output.

[0014] Furthermore, the zero position self-learning step further includes:

[0015] Step 1: Determine whether the zero position self-learning conditions are met. If so, continue with the zero position recording step. If not, enter the standby state.

[0016] Furthermore, the Kp position learning step further includes:

[0017] Step 2: Determine whether the Kp learning condition is met. If so, continue with the Kp position learning step. If not, enter the standby state.

[0018] Based on the same inventive concept, the present invention also provides a transfer case jam detection device for detecting a transfer case jam phenomenon, the device comprising:

[0019] A zero position self-learning module, used for learning the motor zero position of the transfer case when the clutch is completely disengaged;

[0020] A zero position recording module is used to record and update the zero position and the number of stuck times;

[0021] A Kp position learning module, used to learn the motor Kp position of the transfer case when the clutch is transmitting torque stably;

[0022] A Kp position recording learning module is used to record and update the Kp position and subtract the zero position to obtain a relative position;

[0023] The judgment module is used to judge the size of the relative position and the preset minimum limit. If the relative position is greater than the preset minimum limit, no information is output and the transfer case continues to work normally. If the relative position is less than the preset minimum limit, the transfer case jam result is output.

[0024] Furthermore, the device also includes:

[0025] The real-time detection module is used to output a suspected transfer case jam result when the judgment step does not output a transfer case jam result, if the actual motor position of the transfer case deviates from the preset expected motor position by more than a preset distance and time and exceeds a preset time.

[0026] Based on the same inventive concept, the present invention also provides a transfer case jam processing method for processing the transfer case jam phenomenon, wherein the method comprises:

[0027] A transfer case jam detection step, wherein the transfer case jam detection step is specifically the transfer case jam detection method;

[0028] Step 3: When the transfer case jam detection method outputs the transfer case jam result, the control signal is output to control the transfer case motor to perform reverse rotation back to zero, and determine whether the preset self-check condition is met. If so, the process proceeds to step 4; if not, the process enters the standby state;

[0029] Step 4: Record the forward rotation of the transfer case motor to the maximum motor position, recorded as position Pos1, and record the reverse rotation of the transfer case motor to the maximum motor position, recorded as position Pos2, and compare whether the difference between the position Pos1 and the position Pos2 is greater than a preset threshold. If less than, it is determined that the output mechanical stroke is shortened, and a control signal is sent to end the four-wheel drive function;

[0030] Step 5: When the transfer case stuck detection method outputs a suspected transfer case stuck result, a control signal is sent at a preset speed to control the motor to rotate in a direction opposite to the motor movement direction of the current transfer case. If the preset position is not reached within the preset time, the number of slight sticking times is recorded plus 1, and the method returns to the real-time detection step in the transfer case stuck detection method. If the number of slight sticking times is greater than the preset number, it is determined that the output mechanical stroke is shortened, and a control signal is sent to end the four-wheel drive function.

[0031] Based on the same inventive concept, the present invention also provides a transfer case jam processing device for processing the transfer case jam phenomenon, the device comprising:

[0032] A transfer case jam detection module, wherein the transfer case jam detection module is specifically the transfer case jam detection device;

[0033] Module 3 is used to output a control signal to control the motor of the transfer case to perform reverse rotation back to zero when the transfer case jam detection device outputs the transfer case jam result, and to determine whether a preset self-check condition is met, and if so, to start module 4, and if not, to enter a standby state;

[0034] Module 4: used to record the forward rotation of the motor of the transfer case to the maximum motor position, recorded as position Pos1, and record the reverse rotation of the motor of the transfer case to the maximum motor position, recorded as position Pos2, and compare whether the difference between the position Pos1 and the position Pos2 is greater than a preset threshold value. If less than, it is determined that the output mechanical stroke is shortened, and a control signal is sent to end the four-wheel drive function;

[0035] Module 5: When the transfer case jam detection device outputs a suspected jam result of the transfer case, a control signal is sent at a preset speed to control the motor to rotate in the direction opposite to the current motor movement direction of the transfer case. If the preset position is not reached within a preset time, the number of slight jams is recorded plus 1, and the real-time detection step in the transfer case jam detection method is returned. If the number of slight jams is greater than the preset number, it is determined that the output mechanical stroke is shortened, and a control signal is sent to end the four-wheel drive function.

[0036] Based on the same inventive concept, the present invention also provides a transfer case, wherein the transfer case includes the transfer case jam processing device.

[0037] Based on the same inventive concept, the present invention also provides a car, wherein the car comprises the transfer case.

[0038] The present invention is beneficial in that:

[0039] The technical solution provided by the present invention detects the status of the transfer case in real time during its operation, identifies and handles the jam in a timely manner, reduces more serious failures of the transfer case, and improves system reliability and safety.

[0040] It does not rely on newly added detection hardware and sensors, but relies on the original components of the system to perform the jam detection, that is, it does not need to add a new device for detecting the jam.

[0041] Realize the detection and processing of jamming during zero-position learning and Kp-position learning, including the identification of jamming, self-test condition determination, and self-test processing. The final determination of whether there is jamming through the self-test process can reduce false fault alarms as much as possible while ensuring safety.

[0042] The system can detect and handle jams during the normal operation of the transfer case, including key functions such as running jam identification, reverse movement to disengage from jams, counting of minor jams, attempting normal operation with minor jams, and reporting errors when the number of jams exceeds the threshold. It can effectively handle minor jams, and the preset number of minor jams can be calibrated. For systems that are sensitive to jam tolerance, this value can be set to 1, and for other systems, it can be set according to actual conditions.

[0043] If a jam is detected and processed, and if it is considered that the jam has not been eliminated, the fault will be reported and the four-wheel drive function of the vehicle will be disabled to prevent the transfer case from being used incorrectly and ensure safety.

[0044] Key sticking detection and handling parameters can be calibrated based on actual mechanical system characteristics and test performance results.

[0045] It is suitable for use in automobile transfer case manufacturing and research. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is a flow chart of the transfer case sticking detection and processing method mentioned in the eleventh implementation mode. DETAILED DESCRIPTION

[0047] Embodiment 1: This embodiment provides a transfer case jam detection method for detecting a transfer case jam phenomenon, wherein the method comprises:

[0048] Zero position self-learning steps: learning the motor zero position of the transfer case when the clutch is completely disengaged;

[0049] Recording zero position step: recording and updating the zero position, and recording the number of stuck times;

[0050] Kp position learning steps: learning the motor Kp position of the transfer case when the clutch is transmitting torque stably;

[0051] Recording Kp position learning steps: recording and updating the Kp position, and subtracting the zero position to obtain the relative position;

[0052] Judgment step: judge the size of the relative position and the preset minimum limit. If the relative position is greater than the preset minimum limit, no information is output and the transfer case continues to work normally. If the relative position is less than the preset minimum limit, the transfer case jam result is output.

[0053] Specifically, learning refers to the process of controlling the drive motor to make it move in a specific state, and using the speed, torque and other information fed back in real time as a basis for judgment to obtain the key characteristic position of the system. For a transfer case system of this structure, there are zero position learning and Kp position learning. In this solution, no specific learning algorithm is involved or limited.

[0054] It is mainly used in transfer cases where the clutch is driven by an electric motor and a mechanical transmission mechanism.

[0055] Embodiment 2: This embodiment further limits the transfer case jam detection method provided in embodiment 1, and the method further includes:

[0056] Real-time detection step: when the transfer case stuck result is not output in the judgment step, if the actual motor position of the transfer case deviates from the preset expected motor position by more than a preset distance and time, a suspected transfer case stuck result is output.

[0057] Embodiment 3: This embodiment further limits the transfer case jam detection method provided in embodiments 1 and 2, and the zero position self-learning step further includes:

[0058] Step 1: Determine whether the zero position self-learning conditions are met. If so, continue with the zero position recording step. If not, enter the standby state.

[0059] Embodiment 4: This embodiment further limits the transfer case jam detection method provided in embodiments 1 and 2, and the Kp position learning step further includes:

[0060] Step 2: Determine whether the Kp learning condition is met. If so, continue with the Kp position learning step. If not, enter the standby state.

[0061] Embodiment 5: This embodiment provides a transfer case jam detection device for detecting a transfer case jam, and the device comprises:

[0062] A zero position self-learning module, used for learning the motor zero position of the transfer case when the clutch is completely disengaged;

[0063] A zero position recording module is used to record and update the zero position and the number of stuck times;

[0064] A Kp position learning module, used to learn the motor Kp position of the transfer case when the clutch is transmitting torque stably;

[0065] A Kp position recording learning module is used to record and update the Kp position and subtract the zero position to obtain a relative position;

[0066] The judgment module is used to judge the size of the relative position and the preset minimum limit. If the relative position is greater than the preset minimum limit, no information is output and the transfer case continues to work normally. If the relative position is less than the preset minimum limit, the transfer case jam result is output.

[0067] Embodiment 6: This embodiment is a further limitation of the transfer case jam detection device provided in Embodiment 5, and the device further includes:

[0068] The real-time detection module is used to output a suspected transfer case jam result when the judgment step does not output a transfer case jam result, if the actual motor position of the transfer case deviates from the preset expected motor position by more than a preset distance and time and exceeds a preset time.

[0069] Embodiment 7: This embodiment provides a method for handling a transfer case jam, which is used to handle a transfer case jam. The method includes:

[0070] A transfer case jam detection step, wherein the transfer case jam detection step is specifically a transfer case jam detection method provided in the second embodiment;

[0071] Step 3: When the transfer case jam detection method outputs the transfer case jam result, the control signal is output to control the transfer case motor to perform reverse rotation back to zero, and determine whether the preset self-check condition is met. If so, the process proceeds to step 4; if not, the process enters the standby state;

[0072] Step 4: Record the forward rotation of the transfer case motor to the maximum motor position, recorded as position Pos1, and record the reverse rotation of the transfer case motor to the maximum motor position, recorded as position Pos2, and compare whether the difference between the position Pos1 and the position Pos2 is greater than a preset threshold. If less than, it is determined that the output mechanical stroke is shortened, and a control signal is sent to end the four-wheel drive function;

[0073] Step 5: When the transfer case stuck detection method outputs a suspected transfer case stuck result, a control signal is sent at a preset speed to control the motor to rotate in a direction opposite to the motor movement direction of the current transfer case. If the preset position is not reached within the preset time, the number of slight sticking times is recorded plus 1, and the method returns to the real-time detection step in the transfer case stuck detection method. If the number of slight sticking times is greater than the preset number, it is determined that the output mechanical stroke is shortened, and a control signal is sent to end the four-wheel drive function.

[0074] Embodiment 8: This embodiment provides a transfer case jam processing device for processing a transfer case jam, and the device comprises:

[0075] A transfer case jam detection module, wherein the transfer case jam detection module is specifically the transfer case jam detection device according to claim 6;

[0076] Module 3 is used to output a control signal to control the motor of the transfer case to perform reverse rotation back to zero when the transfer case jam detection device outputs the transfer case jam result, and to determine whether a preset self-check condition is met, and if so, to start module 4, and if not, to enter a standby state;

[0077] Module 4: used to record the forward rotation of the motor of the transfer case to the maximum motor position, recorded as position Pos1, and record the reverse rotation of the motor of the transfer case to the maximum motor position, recorded as position Pos2, and compare whether the difference between the position Pos1 and the position Pos2 is greater than a preset threshold value. If less than, it is determined that the output mechanical stroke is shortened, and a control signal is sent to end the four-wheel drive function;

[0078] Module 5: When the transfer case jam detection device outputs a suspected jam result of the transfer case, a control signal is sent at a preset speed to control the motor to rotate in the direction opposite to the motor movement direction of the current transfer case. If the preset position is not reached within a preset time, the number of slight jams is recorded plus 1, and the real-time detection step in the transfer case jam detection method is returned. If the number of slight jams is greater than the preset number, it is determined that the output mechanical stroke is shortened, and a control signal is sent to end the four-wheel drive function.

[0079] Embodiment 9: This embodiment provides a transfer case, and the transfer case includes the transfer case jam processing device provided in embodiment 8.

[0080] Embodiment 10: This embodiment provides a car, which includes the transfer case provided in embodiment 9.

[0081] Implementation Method 11: See Figure 1 This embodiment is described. This embodiment provides a specific implementation process of the transfer case jam processing method provided in the seventh embodiment. Parts thereof also serve as specific explanations of the first to fourth and sixth embodiments. Specifically:

[0082] The system jam detection and processing method flow is as follows Figure 1 As shown. It should be noted that the position value is 0 when the motor is powered on. Therefore, the jamming processing method provided by the present invention is based on the learning and identification of the motor positions corresponding to several key positions of the system. Including the real zero position: the mechanical position corresponding to the minimum compression of the return spring, the complete separation of the clutch, and the motor cannot continue to rotate in the direction of releasing the clutch. The Kp position (clutch KissPoint) refers to the motor position corresponding to the start of stable torque transmission of the clutch.

[0083] Step 1: Determine whether the zero position self-learning conditions are met. If so, go to step 2. If not, continue waiting.

[0084] Step 2: Execute zero-position self-learning. If the learning is successful, go to Step 3. If the learning fails, the transfer case is not ready for use and go to the end.

[0085] Step 3: Record the absolute zero position obtained from zero position self-learning: Pos_Zero. At the same time, assign a value to the number of slight jams N, N = 0. The absolute Kp position value at this time uses the last learned value recorded in NVM (Non-Volatile Memory): Pos_Kp = Pos_KpNVM. Then, perform the Kp self-learning condition judgment. If the Kp self-learning condition is met, go to Step 4; if not, continue to wait.

[0086] Step 4: If the Kp self-learning is executed and successful, update the absolute Kp position to the Motor position value corresponding to the learned Kp position, minus the absolute zero position: Pos_Kp = Pos_Motor - PosZero, and perform the Kp position judgment. If Pos_Kp ≥ the minimum limit value of the reasonable Kp position Pos_KpMin, it indicates that the transfer case state is normal, and go to Step 5. If Pos_Kp < Pos_KpMin, it indicates that mechanical jamming may occur, resulting in the shortening of the mechanical zero position to the Kp position, and go to Step 6.

[0087] Step 5: Enter the normal working state of the transfer case, and the motor moves according to the requirements of the whole vehicle. During the movement, the deviation value between the actual motor position and the expected motor position is detected in real time. If the deviation is greater than Pos_Err (confirmed according to the motor position control accuracy), and the duration is greater than Time_Thresh, it indicates that during the operation, it is suspected that jamming occurs and the motor cannot run to the expected position, and go to Step 8. If the suspected jamming is not met, it means the operation is normal, and continue to be in the normal working state of the transfer case.

[0088] Step 6: Execute the motor to reverse back to the zero position and wait for the self-check condition. If the self-check condition is met, enter Step 7; otherwise, continue to wait for the self-check condition to be met.

[0089] Step 7: Enter the transfer case self-check, control the motor to rotate forward, when the motor torque reaches MotorTorque_Thresh1, record the current motor position Pos1 (the motor position corresponding to the maximum torque transmission of the transfer case working), control the motor to reverse until the motor torque reaches MotorTorque_Thresh2, and record the motor position Pos_2 at this time (the true zero position). Then, judge whether the absolute value of the difference between Pos1 and Pos2 is greater than or equal to the set threshold Pos_Thresh (the minimum value of the difference between the normal working zero position and the maximum torque transmission position of the transfer case). If |Pos1 - Pos2| ≥ Pos_Thresh is met, it indicates that the self-check result is that the operable range of the transfer case meets the requirements, and go to Step 5. If |Pos1 - Pos2| < Pos_Thresh, it indicates that the system self-check indeed has a mechanical stroke shortening caused by jamming, and go to Step 10.

[0090] Step 8: Control the motor's expected position to the Deg_Err position in the opposite direction of the motor's current position, and the rotation speed Spd_Err. If the motor reaches the set expected position within TimeErr (the error from the expected position is less than Pos_Err), it is considered that there is no jamming in the reverse direction, and the number of minor jams is increased by one, N=N+1, and the process goes to Step 9. If the motor cannot reach the set expected position within TimeErr, it is considered that serious bidirectional jamming occurs, and the process goes to Step 10.

[0091] Step 9: Determine whether the number of minor jams is greater than or equal to the set jam threshold. If it does not reach the set number, return to Step 5 and try again to see if normal operation can be performed. If N ≥ N_Thresh, go to Step 10.

[0092] Step 10: Report the jam fault and proceed to the end, completing the jam detection and handling process.

[0093] Among them, Pos_KpMin, Pos_Err, Time_Thresh, MotorTorque_Thresh1, MotorTorque_Thresh2, Pos_Thresh, Deg_Err, Spd_Err, TimeErr, and N_Thresh are all calibrable quantities, which need to be calibrated in combination with mechanical parameters and test characteristics. In Step 8, the setting of TimeErr is directly related to the defined rotation position Deg_Err and the rotation speed Spd_Err. Deg_Err determines the actual torque transmission capacity of the system, so the setting should not be too large. The recommended value is within 10% of the total motor stroke. After determining Deg_Err and Spd_Err, a reasonable TimeErr can be obtained through test calibration.

[0094] The conditions for entering the self-test can be set according to the actual situation. Optionally, it can be set to: when the vehicle is parked but the engine is not turned off, and the steering wheel angle is less than a certain threshold, or when the key door signal becomes Off.

[0095] The above uses several specific implementation modes to further illustrate the technical solution provided by the present invention in detail in order to make the advantages and benefits of the technical solution provided by the present invention more specific, and is not intended to limit the present invention. Any improvements, changes, combinations and equivalent substitutions of the present invention based on the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A transfer case jam detection method, used to detect a transfer case jam, characterized in that: The method includes: Zero position self-learning steps: learning the motor zero position of the transfer case when the clutch is completely disengaged; Recording zero position step: recording and updating the zero position, and recording the number of stuck times; Kp position learning steps: learning the motor Kp position of the transfer case when the clutch is transmitting torque stably; Recording Kp position learning steps: recording and updating the Kp position, and subtracting the zero position to obtain the relative position; Judgment step: judge the size of the relative position and the preset minimum limit. If the relative position is greater than the preset minimum limit, no information is output and the transfer case continues to work normally. If the relative position is less than the preset minimum limit, the transfer case jam result is output.

2. The transfer case jam detection method according to claim 1, characterized in that: The method further comprises: Real-time detection step: when the transfer case stuck result is not output in the judgment step, if the actual motor position of the transfer case deviates from the preset expected motor position by more than a preset distance and time, a suspected transfer case stuck result is output.

3. The transfer case jam detection method according to any one of claims 1 to 2, characterized in that: The zero position self-learning step also includes: Step 1: Determine whether the zero position self-learning conditions are met. If so, continue with the zero position recording step. If not, enter the standby state.

4. The transfer case jam detection method according to any one of claims 1 to 2, characterized in that: The Kp position learning step also includes: Step 2: Determine whether the Kp learning condition is met. If so, continue with the Kp position learning step. If not, enter the standby state.

5. A transfer case jam detection device, used to detect a transfer case jam, characterized in that: The device comprises: A zero position self-learning module, used for learning the motor zero position of the transfer case when the clutch is completely disengaged; A zero position recording module is used to record and update the zero position and the number of stuck times; A Kp position learning module, used to learn the motor Kp position of the transfer case when the clutch is transmitting torque stably; A Kp position recording learning module is used to record and update the Kp position and subtract the zero position to obtain a relative position; The judgment module is used to judge the size of the relative position and the preset minimum limit. If the relative position is greater than the preset minimum limit, no information is output and the transfer case continues to work normally. If the relative position is less than the preset minimum limit, the transfer case jam result is output.

6. The transfer case jam detection device according to claim 5, characterized in that: The device also includes: The real-time detection module is used to output a suspected transfer case jam result when the judgment module does not output a transfer case jam result if the actual motor position of the transfer case deviates from the preset expected motor position by more than a preset distance and time for more than a preset time.

7. A method for handling a transfer case jam, used to handle a transfer case jam, characterized in that: The method includes: A transfer case jam detection step, wherein the transfer case jam detection step is specifically the transfer case jam detection method according to claim 2; Step 3: When the transfer case jam detection method outputs the transfer case jam result, the control signal is output to control the transfer case motor to perform reverse rotation back to zero, and determine whether the preset self-check condition is met. If so, the process proceeds to step 4; if not, the process enters the standby state; Step 4: Record the forward rotation of the transfer case motor to the maximum motor position, recorded as position Pos1, and record the reverse rotation of the transfer case motor to the maximum motor position, recorded as position Pos2, and compare whether the difference between the position Pos1 and the position Pos2 is greater than a preset threshold. If less than, it is determined that the output mechanical stroke is shortened, and a control signal is sent to end the four-wheel drive function; Step 5: When the transfer case stuck detection method outputs a suspected transfer case stuck result, a control signal is sent at a preset speed to control the motor to rotate in a direction opposite to the motor movement direction of the current transfer case. If the preset position is not reached within the preset time, the number of slight sticking times is recorded plus 1, and the method returns to the real-time detection step in the transfer case stuck detection method. If the number of slight sticking times is greater than the preset number, it is determined that the output mechanical stroke is shortened, and a control signal is sent to end the four-wheel drive function.

8. A transfer case jamming treatment device, used to treat a transfer case jamming phenomenon, characterized in that: The device comprises: A transfer case jam detection module, wherein the transfer case jam detection module is specifically the transfer case jam detection device according to claim 6; Module 3 is used to output a control signal to control the motor of the transfer case to perform reverse rotation back to zero when the transfer case jam detection device outputs the transfer case jam result, and to determine whether a preset self-check condition is met, and if so, to start module 4, and if not, to enter a standby state; Module 4: used to record the forward rotation of the motor of the transfer case to the maximum motor position, recorded as position Pos1, and record the reverse rotation of the motor of the transfer case to the maximum motor position, recorded as position Pos2, and compare whether the difference between the position Pos1 and the position Pos2 is greater than a preset threshold value. If less than, it is determined that the output mechanical stroke is shortened, and a control signal is sent to end the four-wheel drive function; Module 5: When the transfer case jam detection device outputs a suspected jam result of the transfer case, a control signal is sent at a preset speed to control the motor to rotate in the direction opposite to the motor movement direction of the current transfer case. If the preset position is not reached within the preset time, the number of slight jams is recorded plus 1, and the real-time detection step in the transfer case jam detection device is returned. If the number of slight jams is greater than the preset number, it is determined that the output mechanical stroke is shortened, and a control signal is sent to end the four-wheel drive function.

9. A transfer case, characterized in that: The transfer case includes the transfer case jam handling device according to claim 8.

10. An automobile, characterized in that The automobile comprises the transfer case according to claim 9.

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