Self-learning method of a clutch and vehicle

Abstract

The application provides a self-learning method of a clutch and a vehicle. The method comprises: when a self-learning trigger condition is met, controlling a motor to operate at a preset rotating speed and controlling the clutch to be combined in an open loop; during the open loop combination, monitoring a variation of an engine operating parameter, a variation of a motor operating parameter and an actual position of the clutch; if the variation of the engine operating parameter or the motor operating parameter is greater than or equal to a corresponding threshold value and the actual separation position of the clutch is in a preset position interval, recording the current actual separation position as a maximum separation position. The application can accurately identify the maximum separation boundary of the clutch by monitoring the matching relationship between the parameter mutation of the vehicle power system and the position interval of the clutch, thereby avoiding the unexpected power transmission and component wear caused by excessive separation.

Description

Technical Field

[0001] This invention relates to the field of automotive control technology, specifically to a self-learning method for a clutch and a vehicle thereof. Background Technology

[0002] In the transmission systems of hybrid and traditional gasoline vehicles, the clutch, as a key actuator connecting the engine and the electric motor (or transmission), plays a crucial role in interrupting and engaging power transmission. Especially in P2 hybrid architectures, where the clutch is located between the engine and the drive motor, its control precision directly affects the vehicle's shift smoothness, starting quality, and energy management efficiency. During vehicle calibration or daily operation, to ensure the control system can accurately identify the clutch's physical limit positions, self-learning is typically used to control clutch action and monitor relevant signals to determine key parameters such as the maximum disengagement position, thus establishing an accurate reference benchmark in subsequent control cycles.

[0003] However, in existing technologies, determining the maximum clutch disengagement position often relies on fixed position thresholds. When the actual disengagement characteristics of the clutch drift due to mechanical tolerances, wear, or temperature changes, the original fixed criteria may fail to accurately obtain the true maximum disengagement boundary, easily leading to over-disengagement or identification errors. This inaccuracy in position recognition may result in unexpected power transmission even when the clutch should be completely disengaged, causing jolts during driving, accelerating abnormal wear of the clutch friction plates, and even affecting the safety of the entire vehicle and the service life of components under extreme conditions. Summary of the Invention

[0004] In view of this, the present invention aims to provide a self-learning method and vehicle for a clutch, which can solve the technical problem in the prior art where the maximum clutch disengagement position is not accurately identified, leading to excessive disengagement and causing unexpected power transmission and component wear.

[0005] This invention provides a self-learning method for a clutch, wherein the clutch is positioned between the engine and the motor of a vehicle. Disengagement of the clutch achieves disengagement of the engine and the motor, while engagement of the clutch achieves connection between the engine and the motor. The self-learning method includes: When the self-learning trigger condition is met, the motor is controlled to run at a preset speed, and the clutch is controlled to engage in open-loop operation. During the clutch engagement / disengagement process, the changes in the engine's operating parameters, the changes in the motor's operating parameters, and the actual position of the clutch are monitored. If the change in the engine's operating parameters is greater than or equal to a first threshold, or the change in the motor's operating parameters is greater than or equal to a second threshold, and the actual disengagement position of the clutch is within a preset position range, then the current actual disengagement position of the clutch is recorded as the maximum disengagement position.

[0006] In one embodiment, the self-learning method further includes: If the change in the engine's operating parameters is less than the first threshold and the change in the motor's operating parameters is less than the second threshold, or if the actual disengagement position of the clutch exceeds the preset position range, then the actual disengagement position of the clutch is detected in real time. When it is detected that the actual disengagement position of the clutch no longer changes, the current actual disengagement position is recorded as the maximum disengagement position.

[0007] In one embodiment, the operating parameters of the engine include the engine speed or the engine torque, and the operating parameters of the electric motor include the electric motor torque.

[0008] In one embodiment, the step of controlling the clutch to engage in open-loop operation includes: The duty cycle at which the overshoot reaches its maximum is obtained as the control duty cycle, wherein the overshoot is the difference between the actual disengagement position and the ideal disengagement position of the clutch; The control duty cycle is adjusted unidirectionally while keeping its sign unchanged.

[0009] In one embodiment, the step of unidirectionally adjusting the control duty cycle while maintaining its sign unchanged includes: If it is detected that the control duty cycle needs to be reverted, the control duty cycle before the revert is maintained for a preset time to prevent the clutch from reverting.

[0010] In one embodiment, the self-learning trigger condition includes at least one of the following: The clutch first self-learning, the actual maximum disengagement position of the clutch exceeds the self-learned maximum disengagement position, the actual maximum disengagement position of the clutch exceeds a preset disengagement position value, wherein the preset disengagement position value is a preset value used when the first self-learning fails, and the engine speed is not 0 or not idle when the clutch is in the disengagement position.

[0011] In one embodiment, the self-learning method further includes: The difference between the actual disengagement position and the ideal disengagement position of the clutch is obtained to determine the overshoot. The difference between the maximum disengagement position and the ideal disengagement position obtained from the previous self-learning of the clutch is used as a comparison value; If the overshoot is less than the comparison value, then a preset separation value is used to determine that the self-learning trigger condition is not met.

[0012] In one embodiment, prior to the step of controlling the motor to operate at a preset speed, the method further includes: The vehicle is controlled to be in a preset self-learning state.

[0013] In one embodiment, the step of controlling the vehicle to be in a preset self-learning state includes: The vehicle is controlled to be stationary, with the handbrake engaged, the engine idling, and the transmission in neutral.

[0014] In another aspect, the present invention provides a vehicle including an engine, an electric motor, and a clutch. The clutch is disposed between the engine and the electric motor. The engine and the electric motor are separated by disengaging the clutch, and connected by engaging the clutch. The clutch is applied to the self-learning method described above.

[0015] Beneficial effects This invention provides a self-learning method for a clutch and a vehicle thereof. The self-learning method includes: when a self-learning trigger condition is met, controlling the motor to run at a preset speed and controlling the clutch to engage in open-loop operation; during the clutch engagement process, monitoring the changes in engine operating parameters, the changes in motor operating parameters, and the actual position of the clutch; if the changes in engine operating parameters are greater than or equal to a first threshold, or the changes in motor operating parameters are greater than or equal to a second threshold, and the actual disengagement position of the clutch is within a preset position range, then recording the current actual disengagement position of the clutch as the maximum disengagement position.

[0016] This solution identifies the maximum disengagement position of the clutch by setting the following conditions: the change in the operating parameters of the engine or motor reaches a set threshold, and the actual disengagement position of the clutch is within a preset position range. By judging through the coupling changes of multiple source parameters, the critical point at which the clutch transitions from a fully disengaged state to a micro-slipping state can be accurately obtained. This effectively solves the problem of maximum disengagement position identification deviation caused by relying on fixed position criteria in existing technologies, and avoids unexpected power transmission phenomena caused by unclear disengagement position definitions. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating a self-learning method for a clutch provided in the first embodiment of the present invention.

[0018] Figure 2 This is a flowchart illustrating a self-learning method for a clutch provided in the second embodiment of the present invention.

[0019] Figure 3 yes Figure 1 The flowchart of step S1 shown is a schematic diagram of an embodiment.

[0020] Figure 4 This is a schematic diagram of overshoot in actual clutch control.

[0021] Figure 5 This is a schematic block diagram illustrating the PID control principle of a clutch.

[0022] Figure 6 This is a flowchart illustrating a self-learning method for a clutch provided in the third embodiment of the present invention.

[0023] Figure 7 This is a structural schematic diagram of a vehicle provided in the third embodiment of the present invention. Detailed Implementation

[0024] 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 the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] In existing technologies, the learning of the maximum clutch disengagement position is often not precise enough, easily leading to over-disengagement. When the clutch disengages too much, the diaphragm spring may act in reverse, resulting in unexpected power transmission, which in turn leads to accelerated clutch wear and other problems, seriously affecting driving experience, safety, and component lifespan. In addition, existing solutions usually determine the maximum disengagement position based on a fixed position or a simple strategy of shifting the slip point upwards. The self-learning results have poor adaptability and are difficult to cover all operating conditions of a batch of vehicles.

[0026] To address the aforementioned problems, this invention provides a self-learning method for a clutch. Please refer to... Figure 1 , Figure 1 A flowchart of a self-learning method for a clutch provided in an embodiment of the present invention is shown. The method includes: Step S1: When the self-learning trigger condition is met, control the motor to run at the preset speed and control the clutch to engage in open-loop operation.

[0027] Step S2: During the clutch engagement / disengagement process, monitor the changes in engine operating parameters, the changes in motor operating parameters, and the actual position of the clutch.

[0028] Step S3: If the change in the engine's operating parameters is greater than or equal to the first threshold, or the change in the motor's operating parameters is greater than or equal to the second threshold, and the actual disengagement position of the clutch is within the preset position range, then record the current actual disengagement position of the clutch as the maximum disengagement position.

[0029] Therefore, this invention first determines the self-learning trigger condition to ensure that the learning process is initiated only when necessary, avoiding invalid operations. Based on this, it controls the motor to operate at a preset speed and provides open-loop engagement commands. Furthermore, it uses changes in engine and motor operating parameters as the primary judgment signals, supplemented by preset position ranges as boundary constraints; these two are used together to determine the maximum disengagement boundary of the clutch. This not only solves the problem of poor adaptability caused by fixed duty cycles or fixed position settings in existing technologies, but also effectively identifies and avoids the risk of over-disengagement, ensuring that the clutch can be precisely controlled at the optimal disengagement point under various operating conditions, thereby extending component life and improving the driving experience.

[0030] The self-learning trigger condition can be the initial initialization command when the vehicle rolls off the production line, or a dynamic trigger signal when a deviation between the actual clutch state and the stored value is detected during vehicle operation. Specifically, the self-learning trigger condition includes at least one of the following situations: the clutch is in the initial self-learning stage; the actual maximum disengagement position of the clutch exceeds the maximum disengagement position that has been self-learned and stored; the actual maximum disengagement position of the clutch exceeds a preset disengagement position value, which is usually the default value used when the initial self-learning fails; or when the clutch is in the disengagement position, the engine speed is detected to be not 0 or not in an idling state. For example, after the vehicle has been running for a long time, the actual disengagement stroke increases due to wear of the clutch friction plates. If it is detected that the currently used disengagement position cannot completely stop the engine (i.e., the engine speed is higher than the idle speed), then the self-learning trigger condition is determined to be met.

[0031] When the self-learning trigger condition is met, the control motor operates at a preset speed. This preset speed can be set according to the vehicle type and testing requirements, for example, to 50 rpm. Operating the control motor at this preset speed ensures a constant input source during clutch engagement.

[0032] The open-loop engagement in step S2 refers to directly driving the clutch actuator to engage based on a preset control quantity. Specifically, open-loop engagement is achieved by outputting a fixed or unidirectionally adjusted duty cycle signal to the clutch solenoid valve or drive motor. Compared to closed-loop control, open-loop engagement avoids control instability caused by feedback delays or oscillations, making it particularly suitable for scenarios requiring the search for mechanical limit positions. By controlling the motor to operate at a preset speed and coordinating it with the open-loop engagement of the clutch, the maximum disengagement position can be located solely based on the sudden changes in power system parameters caused by mechanical contact, while eliminating interference from closed-loop control.

[0033] In step S3, the engine's operating parameters specifically include engine speed or engine torque. The change in engine operating parameters refers to the absolute value of the difference between the currently collected engine operating parameters and the reference values ​​at the start of self-learning or the previous sampling time. For example, if engine speed is the monitored object, when the clutch begins to engage from a fully disengaged state, the engine load will increase instantaneously, causing the speed to drop. The monitored change in speed at this time is the absolute value of the difference between the reference speed and the current speed.

[0034] The operating parameters of an electric motor include its torque. The change in these parameters refers to the absolute value of the difference between the current motor torque and the reference torque. In the initial stage of clutch engagement, since the motor and engine have not yet established an effective connection, the motor torque is primarily used to maintain its preset speed. Once the clutch begins to engage, the motor needs to share some of the engine resistance or is dragged back by the engine, causing its output torque to fluctuate significantly.

[0035] The actual position of the clutch refers to the physical displacement value of the clutch release bearing or pressure plate, measured in real time by a displacement sensor, typically in millimeters (mm). Monitoring this actual position is crucial for determining the current mechanical state of the clutch and ensuring that subsequent judgments are made within the effective travel range. During clutch engagement, the clutch position, engine speed, and motor torque exhibit changes over time. Specifically, in the initial stage of clutch engagement, the clutch position gradually decreases (indicating deeper engagement), while the engine speed and motor torque remain relatively stable. When a certain critical point is reached, the engine speed drops significantly, and the motor torque jumps; this abrupt change corresponds to the moment the clutch begins to transmit power.

[0036] By monitoring the changes in the operating parameters of the engine and motor, as well as the actual position of the clutch in real time, the instantaneous characteristics of power coupling can be fully obtained. By using the collaborative verification of multi-source data, the risk of misjudgment caused by noise from a single sensor can be eliminated, ensuring that the acquired signal truly reflects the mechanical contact state of the clutch.

[0037] The first and second thresholds are empirical values ​​used to determine whether the clutch has started transmitting power. Their settings can be determined based on vehicle calibration data. For example, the first threshold can be set to an engine speed change ≥ 50 rpm or an engine torque change ≥ 20 Nm, and the second threshold can be set to an electric motor torque change ≥ 20 Nm. When the monitored change reaches or exceeds these thresholds, it indicates that sufficient friction has been generated between the clutch friction plates, and power transmission has begun. The preset position range is a safe and effective range defined based on the clutch's mechanical structure characteristics, used to filter out abnormal position points caused by sensor drift or extreme mechanical failures. For example, the preset position range can be set to [10 mm, 14 mm]. Only when a sudden change in power parameters is detected (meeting the threshold conditions) and the actual clutch position falls within this range is the true maximum disengagement position considered to have been found. If the position exceeds this range, even if the parameters change, it may be considered an abnormal operating condition or noise interference and will not be recorded.

[0038] The previous section introduced a scheme for determining the maximum clutch disengagement position when changes in engine or motor operating parameters all meet preset threshold conditions, and the clutch disengagement position is within a preset range. The following section will introduce a scheme for determining the maximum clutch disengagement position when the above conditions are not met. Please refer to [link to relevant documentation] for details. Figure 2 This includes the following steps: Step S4: If the change in the engine's operating parameters is less than the first threshold and the change in the motor's operating parameters is less than the second threshold, or if the actual disengagement position of the clutch exceeds the preset position range, then the actual disengagement position of the clutch is detected in real time.

[0039] Step S5: When the actual disengagement position of the clutch is no longer changing, record the current actual disengagement position as the maximum disengagement position.

[0040] In step S4, the change in engine operating parameters being less than the first threshold and the change in motor operating parameters being less than the second threshold can mean that during the aforementioned open-loop engagement process, neither the engine nor the motor experienced the expected load change or speed fluctuation, i.e., the clutch was not engaged or the contact force was extremely small, failing to transmit sufficient torque to cause a significant change in the power source parameters. The actual clutch disengagement position exceeding the preset position range means that the current physical displacement of the clutch exceeds the theoretical maximum disengagement position range. For example, if the preset position range is [10mm, 14mm], and the actual detected position is greater than 14mm or less than 10mm, this indicates possible sensor zero-point drift, mechanical jamming, or initial calibration deviation. When the engine speed change is only 10rpm (less than the first threshold of 50rpm), and the motor torque change is 5Nm (less than the second threshold of 20Nm), while the clutch position is displayed as 15mm (exceeding the upper limit of 14mm), the system immediately switches to real-time monitoring mode to continuously track the actual clutch disengagement position. This dual-condition logic or judgment can cover various boundary situations where the main features are not obvious due to abnormal operating conditions, ensuring that the self-learning process will not be interrupted due to the lack of a single criterion.

[0041] In step S5, the actual separation position no longer changes. This can mean that the reading of the clutch displacement sensor remains constant over multiple consecutive sampling periods, or that its rate of change is below a preset small threshold (e.g., the displacement change is less than 0.01mm within 500ms). At this point, the current actual separation position is recorded as the maximum separation position and updated as the reference value for the maximum separation position used in subsequent control strategies. For example, during real-time monitoring, if the controller detects that the clutch position slowly moves from 13.5mm to 14.2mm, and then remains unchanged at 14.2mm for the next 2 seconds, the system determines that the clutch has reached its true physical limit and records 14.2mm as the maximum separation position.

[0042] By real-time monitoring of the clutch's dynamic behavior when the actual disengagement position deviates from the expected parameter changes or exceeds the preset range, and combining this with a position static criterion to ultimately determine the maximum disengagement position, seamless switching is achieved in scenarios where the main criterion fails. This ensures accurate maximum disengagement position data can be obtained under various complex vehicle operating conditions, sensor noise interference, or individual mechanical differences, thus providing reliable basic parameters for precise clutch control and fault warning.

[0043] Please see Figure 3 , Figure 3 This is the specific implementation method of "controlling the clutch to engage in open-loop" in step S1 above. For example... Figure 3 As shown, it includes the following steps: Step S11: Obtain the duty cycle at which the overshoot reaches its maximum as the control duty cycle, where the overshoot is the difference between the actual disengagement position and the ideal disengagement position of the clutch.

[0044] Step S12: Adjust the control duty cycle in one direction while keeping its sign unchanged.

[0045] Overshoot refers to the deviation of the actual displacement of the clutch from the target command displacement due to system inertia or response lag during the clutch's disengagement or engagement process. Its value is equal to the actual disengagement position of the clutch minus the ideal disengagement position. The control duty cycle is the duty cycle value of the pulse width modulation signal used to drive the clutch actuator (such as a solenoid valve or drive motor), and its magnitude determines the speed and force of the actuator's action. This control duty cycle is obtained by analyzing historical data from the clutch during the previous PID (proportional, integral, and derivative) closed-loop control phase. Specifically, before step S11, the PID conditions are executed, recording the duty cycle output value and its corresponding overshoot at each moment during the PID adjustment process. The duty cycle corresponding to the moment when the overshoot reaches its peak value is selected and determined as the control duty cycle for the subsequent open-loop engagement phase. For example, in PID control, if the actual clutch position exceeds the ideal position by 0.8mm (the maximum overshoot in this process) when the duty cycle is 65%, and the overshoot corresponding to other duty cycles is less than this value, then 65% is determined as the control duty cycle. As shown in Figure 4, which is a schematic diagram of the overshoot in the actual clutch control provided by this invention, Figure 4 shows that the portion of the actual position (i.e., the actual displacement in the figure) curve that is higher than the ideal position (i.e., the target displacement in the figure) curve in the clutch dynamic response curve is the overshoot region. The peak point corresponds to the moment of maximum overshoot, and the control input corresponding to this moment is the selected control duty cycle. By selecting the duty cycle that maximizes the overshoot, it is ensured that the open-loop control signal has sufficient energy to overcome mechanical resistance and friction, allowing the clutch to quickly and fully reach the limit disengagement position, while avoiding jamming or incomplete engagement due to individual differences in the fixed duty cycle.

[0046] Step S12 executes a one-way adjustment mechanism. This one-way adjustment ensures the clutch changes only along a single trend or remains constant, strictly prohibiting reverse backlash. The unchanged sign can mean that the polarity (positive or negative) of the duty cycle or the direction of its change trend remains consistent throughout the open-loop engagement phase. For example, if a positive value represents the disengagement direction and a negative value represents the engagement direction, then during disengagement, the duty cycle always remains non-negative, and even when a positional deviation is detected requiring fine-tuning, switching to a negative value range is not allowed. Specifically, when the system determines that open-loop engagement is necessary, it locks the sign of the current control duty cycle. Any subsequent calculations that cause the sign to flip will be intercepted and forcibly maintained at the sign and value before locking. This one-way adjustment strategy works in conjunction with the aforementioned step of obtaining the maximum overshoot duty cycle. The former provides the optimal power input reference, while the latter ensures the continuity and directional consistency of the power input. Together, they ensure that the clutch can stably reach and maintain the maximum disengagement position without feedback oscillation interference, thus providing a reliable physical state basis for accurately recording the maximum disengagement position.

[0047] In practical applications, if a control duty cycle correction is detected, the control duty cycle is maintained for a preset time before the correction to prevent clutch correction. Detecting a need for control duty cycle correction refers to a situation where, during unidirectional adjustment of the control duty cycle, the control system determines, based on the changing trend of the difference between the current actual separation position and the ideal separation position, that the polarity (sign) of the duty cycle should be changed or the duty cycle value should be significantly reduced according to conventional PID logic or adaptive algorithms. For example, as the clutch gradually approaches the target position, conventional closed-loop control logic might calculate that the driving force needs to be reduced or even a reverse force applied (i.e., the duty cycle changes from positive to negative) to suppress overshoot or achieve rapid stabilization; this is considered a need for correction. In this case, the correction instruction is not executed immediately; instead, the last valid duty cycle value before the determination time is locked and continuously output for a preset time. This preset time is set based on the mechanical response characteristics of the clutch actuator, the pressure build-up / de-pressure delay of the hydraulic or pneumatic system, and the time required to eliminate mechanical backlash; for example, it can be set to 5 seconds. During this period, regardless of changes in the position error reported by the sensor, the duty cycle signal output to the clutch solenoid valve or drive motor remains unchanged. To avoid the clutch actuator from reversing or significantly attenuating due to premature reversal of the control signal, the original duty cycle is maintained for a preset time. This ensures that the actuator has sufficient time to overcome system lag, fully reach and stabilize at the true maximum disengagement position, thus guaranteeing the accuracy of the self-learning data.

[0048] Please see Figure 5This invention also provides a specific implementation method for obtaining the control duty cycle. As shown in Figure 5, Figure 5 is a block diagram of the basic principle of PID control of the clutch provided by this invention. In the PID control process, the controller receives the clutch target disengagement position command and, combined with the actual disengagement position fed back by the displacement sensor, dynamically adjusts the output duty cycle through the proportional-integral-derivative (PID) algorithm to eliminate position errors. For example, when the clutch needs to disengage quickly from the engaged state, the PID controller may output a large positive duty cycle (e.g., 80%). As the actual position approaches the target position, the duty cycle gradually decreases to a maintenance value (e.g., 30%). This duty cycle acquisition process is carried out throughout the vehicle's normal operating conditions such as starting, shifting, and stopping, forming a rich historical operating dataset, which provides a source for subsequent selection of optimal control parameters.

[0049] Under PID control, the difference between the actual and ideal clutch disengagement positions is obtained. This difference is calculated by subtracting the actual disengagement position, measured in real-time by a clutch displacement sensor, from the ideal disengagement position (target position) set by the controller at the same moment. In actual operation, due to factors such as mechanical backlash, hydraulic hysteresis, or load variations, the actual position often fluctuates around the ideal position, and may even exceed the target position during rapid response phases (i.e., overshoot). For example, during rapid deceleration, the clutch disengages quickly, and the actual position may momentarily exceed the ideal disengagement position by 2mm; the recorded difference is 2mm. The trend of this difference directly characterizes the dynamic performance of the system under different duty cycles and is a key indicator for evaluating the system's critical state.

[0050] Finally, the duty cycle corresponding to the maximum difference is obtained to determine the control duty cycle. This control duty cycle is determined by iterating and comparing a series of recorded difference and duty cycle data pairs to identify the duty cycle corresponding to the moment when the difference reaches its peak. Its function is to capture the critical point when the system is about to enter an unstable region or when the response is most sensitive, and use this point as the reference input for subsequent open-loop integration, which can cover the differences in mechanical characteristics of different vehicles to the greatest extent.

[0051] The above describes a solution under self-learning conditions. In practical applications, there are situations where self-learning is not fully met. Please refer to [link / reference needed] for details. Figure 6 This includes the following steps: Step 6: Obtain the difference between the actual disengagement position and the ideal disengagement position of the clutch to obtain the overshoot.

[0052] Step 7: Obtain the difference between the maximum disengagement position and the ideal disengagement position obtained from the clutch's last self-learning as a comparison value.

[0053] Step 8: If the overshoot is less than the comparison value, then use the preset separation value to determine that the self-learning trigger condition is not met.

[0054] The comparison value is calculated by retrieving the maximum separation position from the last successful self-learning record stored in memory and subtracting the current ideal separation position. By introducing this historical data, the system can distinguish between occasional control fluctuations and long-term performance drift.

[0055] Step S8 determines whether to initiate the time-consuming self-learning process by comparing the current dynamic deviation with the historical baseline deviation. The execution entity is the vehicle's control unit, which performs logical judgments based on the overshoot and comparison values ​​calculated in the preceding steps. Specifically, when the current overshoot value is detected to be significantly less than the historical comparison value, it indicates that the current actual clutch disengagement position is closer to the ideal position than the previous self-learning state, or at least there is no deterioration trend, and the system is in a controllable and stable state. In this case, the control unit directly calls the preset disengagement value as the effective disengagement position parameter under the current operating condition and determines that the self-learning trigger condition is not met, thus skipping subsequent self-learning steps such as motor speed control and open-loop engagement.

[0056] In practical applications, before step S1 (controlling the motor to operate at a preset speed), the vehicle needs to be in a preset self-learning state. This means that before self-learning the maximum clutch disengagement position, the vehicle must meet a series of static or quasi-static operating conditions. This eliminates dynamic disturbances during vehicle operation, such as inertial forces, road load fluctuations, and transmission system shocks, providing a stable and controllable physical environment for subsequent motor speed control and clutch open-loop engagement. Specifically, the preset self-learning state can include the vehicle being stationary, the handbrake engaged, the engine idling, and the transmission in neutral. In this scenario, the vehicle is mechanically locked, the transmission cuts off power output to the wheels, and the engine maintains only the minimum stable speed. This allows subsequent changes in engine or motor operating parameters to be purely attributed to minor clutch engagement rather than changes in vehicle driving resistance. This rigorous condition screening effectively avoids misjudgments during dynamic driving caused by sudden load changes, significantly improving the repeatability and data reliability of the self-learning process.

[0057] The present invention also provides a vehicle, please refer to [link / reference]. Figure 7The vehicle 70 includes an engine 71, an electric motor 72, and clutches 73 and 74. Clutch 73 is located between the engine 71 and the electric motor 72. Disengaging clutch 73 disconnects the engine 71 and the electric motor 72, while engaging clutch 73 connects the engine 71 and the electric motor 72. Transmission 74 is located at the output end of either the electric motor 72 or the clutch 73 and is used to adjust the input speed. Clutch 73 is used in the self-learning method described above.

[0058] In summary, this invention provides a self-learning method for a clutch and a vehicle thereof. The self-learning method includes: when the self-learning trigger condition is met, controlling the motor to run at a preset speed and controlling the clutch to engage in open-loop operation; during the clutch engagement process, monitoring the changes in engine operating parameters, the changes in motor operating parameters, and the actual position of the clutch; if the changes in engine operating parameters are greater than or equal to a first threshold, or the changes in motor operating parameters are greater than or equal to a second threshold, and the actual disengagement position of the clutch is within a preset position range, then recording the current actual disengagement position of the clutch as the maximum disengagement position. This effectively solves the problem of maximum disengagement position identification deviation caused by relying on fixed position criteria in the prior art, and avoids unexpected power transmission phenomena caused by unclear disengagement position definitions.

[0059] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0060] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A self-learning method for a clutch, characterized in that, The clutch is positioned between the vehicle's engine and motor. Disengaging the clutch separates the engine and motor, while engaging the clutch connects them. The self-learning method includes: When the self-learning trigger condition is met, the motor is controlled to run at a preset speed, and the clutch is controlled to engage in open-loop operation. The self-learning trigger condition is the first initialization command when the vehicle rolls off the production line, or the dynamic trigger signal when a deviation between the actual state of the clutch and the stored value is detected during vehicle operation. The open-loop engagement refers to directly driving the clutch actuator to engage according to the preset control quantity. During the clutch engagement / disengagement process, the changes in the engine's operating parameters, the changes in the motor's operating parameters, and the actual position of the clutch are monitored. If the change in the engine's operating parameters is greater than or equal to a first threshold, or the change in the motor's operating parameters is greater than or equal to a second threshold, and the actual disengagement position of the clutch is within a preset position range, then the current actual disengagement position of the clutch is recorded as the maximum disengagement position. The step of controlling the clutch to engage in open-loop operation includes: obtaining the duty cycle at which the overshoot reaches its maximum as the control duty cycle, wherein the overshoot is the difference between the actual disengagement position and the ideal disengagement position of the clutch; and unidirectionally adjusting the control duty cycle while keeping its sign unchanged.

2. The self-learning method according to claim 1, characterized in that, The self-learning method also includes: If the change in the engine's operating parameters is less than the first threshold and the change in the motor's operating parameters is less than the second threshold, or if the actual disengagement position of the clutch exceeds the preset position range, then the actual disengagement position of the clutch is detected in real time. When it is detected that the actual disengagement position of the clutch no longer changes, the current actual disengagement position is recorded as the maximum disengagement position.

3. The self-learning method according to claim 1 or 2, characterized in that, The engine's operating parameters include the engine speed or the engine torque, and the motor's operating parameters include the motor torque.

4. The self-learning method according to claim 1, characterized in that, The step of unidirectionally adjusting the control duty cycle while keeping its sign unchanged includes: If it is detected that the control duty cycle needs to be reverted, the control duty cycle before the revert is maintained for a preset time to prevent the clutch from reverting.

5. The self-learning method according to claim 1, characterized in that, The self-learning triggering condition includes at least one of the following: The clutch first self-learning, the actual maximum disengagement position of the clutch exceeds the self-learned maximum disengagement position, the actual maximum disengagement position of the clutch exceeds a preset disengagement position value, wherein the preset disengagement position value is a preset value used when the first self-learning fails, and the engine speed is not 0 or not idle when the clutch is in the disengagement position.

6. The self-learning method according to claim 1, characterized in that, The self-learning method also includes: The difference between the actual disengagement position and the ideal disengagement position of the clutch is obtained to determine the overshoot. The difference between the maximum disengagement position and the ideal disengagement position obtained from the previous self-learning of the clutch is used as a comparison value; If the overshoot is less than the comparison value, then a preset separation value is used to determine that the self-learning trigger condition is not met.

7. The self-learning method according to claim 1, characterized in that, Before the step of controlling the motor to run at a preset speed, the method further includes: The vehicle is controlled to be in a preset self-learning state.

8. The self-learning method according to claim 7, characterized in that, The steps of controlling the vehicle to be in a preset self-learning state include: The vehicle is controlled to be stationary, with the handbrake engaged, the engine idling, and the transmission in neutral.

9. A vehicle, characterized in that, The vehicle includes an engine, a motor, and a clutch. The clutch is disposed between the engine and the motor. The engine and the motor are separated by disengaging the clutch, and connected by engaging the clutch. The clutch is applied to the self-learning method as described in any one of claims 1-8.

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