Engine torque unloading and clutch disengagement method and system

Abstract

The application provides an engine torque unloading and clutch separation method and system, and relates to the technical field of intelligent control.The method comprises the following steps: calculating the engine request torque by using a feedforward-feedback compound control architecture, calculating a dynamic torque reduction slope based on the fusion of multi-dimensional feedforward parameters such as gear position, mass, slope, initial torque and throttle opening, and introducing an engine speed change rate for closed-loop feedback correction; calculating the clutch target torque in the first stage, introducing an adaptive attenuation factor based on the torque unloading process, so that the clutch separation rate dynamically follows the engine torque unloading; when the end condition is met, entering the second stage, and adaptively adjusting the clutch target torque according to the shift type and slope to complete the rapid separation. The application realizes the precise cooperation of engine torque unloading and clutch separation through multi-dimensional parameter fusion and closed-loop feedback, effectively solves the shift impact and jerk problem, and significantly improves the shift smoothness and system reliability of the AMT vehicle under various working conditions.

Description

Technical Field

[0001] This invention relates to the field of intelligent control technology, and in particular to a method and system for engine torque unloading and clutch disengagement. Background Technology

[0002] An automated manual transmission (AMT) is a stepped mechanical automatic transmission based on a traditional dry clutch and manual gear transmission, with the addition of an electronic control system to transform the manual shifting mechanism into an automatic shifting mechanism. During AMT shifting, the power cut-off phase is a critical stage affecting shift quality. The rapid and precise reduction of engine torque and the timely and smooth disengagement of the clutch are the core technical challenges in achieving seamless power switching. Improper coordination between engine torque unloading and clutch disengagement will directly lead to unpleasant phenomena such as shocks and jerks, severely impacting driving comfort; it will also accelerate the wear of the clutch friction plates, shorten the service life of transmission system components, and may even cause drivetrain shocks, affecting vehicle driving safety.

[0003] Traditional AMT shift control methods often employ fixed-slope open-loop control strategies, which struggle to adapt to complex conditions such as changes in vehicle mass, road gradients, diverse driver intentions, and variations in system dynamics. In practical applications, this can easily lead to jerking sensations caused by excessively rapid torque reduction or clutch disengagement, or clutch drag and overheating issues due to excessively slow torque reduction. The core logic of existing solutions is "calculate time first, then decide on the action," essentially still an open-loop timing scheduling strategy. Before shifting begins, the system calculates the remaining torque reduction time and clutch disengagement time based on the initial state, and then executes according to a preset timing sequence. Once the actual operating conditions deviate from the preset conditions, the pre-calculated timing sequence loses accuracy, causing misalignment between engine torque unloading and clutch disengagement, failing to achieve true dynamic coordination. In existing solutions, the engine torque reduction rate is calculated only once based on finite parameters such as gear position, transmission stiffness, and initial torque, remaining constant throughout the torque reduction process. This fixed-slope control method cannot adapt to nonlinear conditions such as changes in vehicle mass, road gradients, and high loads at low throttle, nor can it respond to driver intervention during shifting. Under heavy load or uphill conditions, a fixed torque reduction slope may result in insufficient torque unloading and clutch slippage; under low torque conditions, a fixed slope may cause unnecessary torque fluctuations or jerking.

[0004] Therefore, there is an urgent need for an adaptive and coordinated control method and system that can achieve engine torque unloading and clutch disengagement, which automates gear shifting through electronic control, reduces the driver's workload, and ensures vehicle driving safety. Summary of the Invention

[0005] The main objective of this invention is to provide a method and system for engine torque unloading and clutch disengagement, which solves the problem of shock and jerking caused by the mismatch between torque unloading and clutch action in traditional shift control, thereby improving shift smoothness and driving experience.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is an engine torque unloading and clutch disengagement method, comprising the following steps: S1. The engine requested torque is calculated using a feedforward-feedback composite control architecture. The feedforward-feedback composite control architecture includes: calculating the dynamic torque reduction slope based on multi-dimensional feedforward parameters, and coupling the engine speed change rate feedback correction coefficient in real time, and obtaining the engine requested torque through iterative updates. S2. The first stage of calculating the clutch target torque based on the engine requested torque includes: generating the clutch feedforward target torque, introducing a decay factor that dynamically changes according to the engine unloading process, and dynamically updating the clutch requested torque through an iterative formula to achieve dynamic coupling between the clutch disengagement rate and the engine torque unloading process. S3. After the end conditions of the first stage are met, the target torque of the clutch is adaptively adjusted according to the shift load state in the second stage to complete the rapid disengagement of the clutch.

[0007] Preferably, in step S1, calculating the requested engine torque specifically includes: According to the current gear Obtaining the basic torsional slope ; Based on vehicle mass and road slope Obtain the quality-ramp correction factor ; Based on the initial torque Obtain the initial torque correction coefficient ; According to throttle opening and initial torque Obtain the throttle-initial torque coupling correction coefficient ; Based on engine speed change rate Obtain the feedback correction coefficient for the rate of change of rotational speed ; Calculate the dynamic torsional slope using the following formula : ; Iterative update of engine requested torque using the following formula : ; in, Request torque for the engine in the current control cycle. This represents the actual engine torque from the previous control cycle. To control the cycle.

[0008] Preferably, in step S1, the mass-ramp correction factor is... With the initial torque correction coefficient The two values ​​are compared, and the smaller value is taken as the safety correction factor. Used to participate in dynamic torsional slope reduction The calculation.

[0009] Preferably, in step S2, the first stage of calculating the target clutch torque specifically includes: Calculate the offset coefficient using the following formula : ; in, This is the maximum torque value of the clutch. This is the engine's maximum torque. This is a correction term for operating conditions with relatively low initial torque; Calculate the clutch feedforward target torque using the following formula : ; in, Request torque for the engine; Introducing a decay factor for the engine torque unloading process The clutch torque request is updated iteratively using the following formula. : ; in, Request torque for the clutch in the current control cycle. The clutch requests torque for the previous control cycle. Furthermore, it dynamically maps the process based on the real-time progress of engine torque unloading: the initial unloading stage. The value is relatively large, and it increases as the uninstallation process progresses. Monotonically decreasing, as unloading nears completion The value is significantly reduced.

[0010] Preferably, in step S3, the end condition of the first stage includes: the actual engine torque. Less than the set torque threshold Furthermore, the clutch disengagement action lasts for more than a set time threshold. ; Torque threshold Calculate using the following formula: ; in, To be based on quality and slope The base torque value was determined by referring to the table. This is the gear correction factor.

[0011] Preferably, the gear correction coefficient The value range is [0,1], and the lower the gear, the better. The smaller the value, the longer the timing of the first phase ends.

[0012] Preferably, in step S3, the second stage of the clutch target torque is calculated using the following formula: ; That is, according to the shift type Select the corresponding lookup function, based on road slope. To obtain the target clutch torque; in flat or uphill mode and not in power-free upshift mode, The torque is less than the torque corresponding to the clutch engagement point; this applies to downhill driving conditions or when upshifting without power. It is greater than the torque corresponding to the clutch engagement point.

[0013] Preferably, in step S3, the multi-dimensional feedforward parameters include: gear position, vehicle mass, road gradient, initial torque, and throttle opening.

[0014] This invention provides an engine torque unloading and clutch disengagement system for implementing the above method, comprising: The multi-source information acquisition module is used to collect road conditions, vehicle operating parameters, and driver input information; The engine torque calculation module adopts a feedforward-feedback composite control architecture to execute the engine requested torque calculation logic. The clutch torque calculation module executes the two-stage clutch target torque calculation logic. The actuator control module sends control commands to the engine ECU and clutch actuator respectively based on the calculated engine requested torque and clutch target torque; The status feedback module collects the actual execution status of the engine and clutch in real time and feeds it back to the engine torque calculation module and clutch torque calculation module to form a closed-loop control.

[0015] Preferably, a hierarchical control architecture is adopted, including an input layer, a computing layer and a physical layer, with data interaction between the layers via a CAN bus.

[0016] Beneficial effects: 1. Improved shift smoothness and elimination of jerking: This invention dynamically calculates the engine torque reduction slope through a feedforward-feedback composite control architecture and introduces an adaptive decay factor based on the torque unloading process to adjust the clutch disengagement rate in real time, achieving precise coordination between engine torque unloading and clutch disengagement throughout the entire process. Compared with existing open-loop timing control strategies, this invention can effectively avoid transmission chain shocks caused by misalignment between torque reduction and disengagement actions, significantly improving shift smoothness and driving comfort under various operating conditions.

[0017] 2. Strong adaptability to various operating conditions, covering complex scenarios: This invention constructs a torque reduction slope calculation model that includes multi-dimensional feedforward parameters such as gear position, vehicle mass, road slope, initial torque, and throttle opening, and introduces a minimum value selection arbitration mechanism to form a safety lower limit constraint. Simultaneously, the second stage employs a differentiated separation strategy based on gear shift type and slope, enabling adaptive handling of nonlinear operating conditions such as heavy loads, uphill, downhill, and low throttle high loads, overcoming the poor adaptability of existing fixed slope control systems.

[0018] 3. Shorten shift power interruption time and improve response speed: This invention introduces the engine speed change rate as a real-time feedback signal. When a continuous increase in engine speed is detected, it actively increases the torque reduction slope to accelerate the torque unloading process. At the same time, in the initial stage of the first phase, the clutch is allowed to follow quickly, effectively shortening the total power cut-off time and improving shift response performance and vehicle dynamics.

[0019] 4. Improved System Robustness and Safety: This invention employs a minimum value selection arbitration strategy, utilizing the initial torque coefficient to form a safety lower limit constraint on mass and gradient estimation deviations, preventing excessively high torque reduction slope values ​​from causing impacts. Simultaneously, the torque threshold in the first stage introduces a gear correction coefficient to achieve smooth disengagement in low gears, and a time threshold limits the maximum clutch disengagement speed, forming multiple safety protection mechanisms to ensure the hardware reliability and control stability of the transmission system. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a flowchart of the overall method for AMT shift coordination control of the present invention; Figure 2 This is a flowchart of the engine torque unloading adaptive control of the present invention; Figure 3 This is a structural diagram of the control system of the present invention. Detailed Implementation

[0021] Example 1 like Figure 1 As shown, a method for unloading engine torque and disengaging the clutch includes the following steps: S1, Shift control: When the AMT control system determines that the shift conditions are met, the shift control process is triggered, and the engine torque unloading control and clutch disengagement control are started simultaneously. S2. Acquisition and preprocessing of multi-source input information: The system synchronously acquires and preprocesses multi-source heterogeneous input information through the vehicle's CAN bus and sensor network, providing accurate decision input for subsequent feedforward-feedback composite control. S3. Engine requested torque calculation adopts a strategy that combines multi-dimensional feedforward parameter fusion and real-time feedback correction, and calculates engine requested torque based on feedforward-feedback composite control architecture. S4. First stage calculation of clutch target torque: Based on the calculation of the engine requested torque, the system generates the clutch feedforward torque target value according to the preset correction coefficient, and introduces the attenuation factor according to the engine unloading torque process to correct the feedforward target value in real time, thereby adjusting the clutch disengagement rate. S5. The second stage of clutch target torque calculation is completed. The second stage completes the rapid disengagement of the clutch and adaptively adjusts the clutch target torque according to the shift load state.

[0022] According to an embodiment of the present invention, in step S2, the system synchronously collects multi-source heterogeneous input information through the vehicle CAN bus and sensor network at a control cycle of 10ms, including: Road condition information: road gradient, turning radius; Vehicle operating parameters: estimated vehicle mass, tire slippage rate, actual clutch torque, vehicle speed, engine speed, transmission input shaft speed, actual engine torque, current gear and target gear; Driver input requirements: throttle opening and power mode requirements.

[0023] All input data are tagged with a uniform timestamp and aligned using linear interpolation based on the timestamp to ensure the spatiotemporal synchronization of multi-source data.

[0024] According to an embodiment of the present invention, in step S3, the system calculates the engine requested torque according to a feedforward-feedback composite control architecture. Specifically, this includes: calculating the dynamic torque reduction slope based on multi-dimensional feedforward parameters such as mass, gradient, initial torque, and throttle opening, and coupling the engine speed change rate feedback correction coefficient in real time, and obtaining the engine requested torque for the current control cycle through iterative updates.

[0025] According to an embodiment of the present invention, in step S4, based on the calculation of the requested engine torque, the system generates a target value of the feedforward torque of the clutch according to a preset correction coefficient, and introduces a decay factor based on the engine unloading torque process to correct the target value of the feedforward in real time, thereby realizing the dynamic coupling of the clutch disengagement rate and the engine torque unloading process.

[0026] The system calculates the offset coefficient as shown in equation (1): (1); in, Based on the maximum torque transmission capacity of the clutch With engine maximum torque The benchmark coefficient obtained from the ratio; This is a correction function for the condition where the engine's initial torque is relatively low. Below the preset threshold hour, Take a positive value to increase The coefficient is used to control the rate of torque reduction in the clutch, thus preventing jerking caused by excessively rapid clutch disengagement. In this embodiment, .

[0027] The system calculates the engine requested torque and the calculated offset coefficient based on step S3. The target torque for clutch feedforward is generated as shown in equation (2) below: (2); The system dynamically calculates the clutch request torque for each control cycle using an iterative formula, as shown below: (3); in, This indicates the clutch torque request for the current control cycle. This indicates the clutch torque request from the previous control cycle. The target torque for the current control cycle is the feedforward torque. This is the attenuation factor for the engine torque unloading process, and its value changes dynamically within the range of [0,1].

[0028] Attenuation factor Dynamic mapping is performed based on the real-time progress of engine torque unloading: defining the unloading process ratio. This is the ratio of the current actual engine torque to the initial torque, i.e. During the initial uninstallation phase, Approaching 1, The value is 0.8, which makes It can approach the value at a relatively fast rate. As the uninstallation process proceeds, Gradually decrease, Monotonically decreasing; as unloading nears completion, Approximately 0.2 The value is 0.1. The rate of change forms a strong constraint, causing the change to tend to be gradual.

[0029] The system monitors the end conditions of the first phase in real time. The first phase is considered complete when both of the following conditions are met: The actual engine torque is less than the set threshold. ,Right now ; The clutch disengagement action lasts longer than the set threshold. ,Right now .

[0030] Wherein, the torque threshold The value is determined by the vehicle mass, road gradient, and current gear, as shown in equation (4) below: (4); in, The base torque value is determined by looking up a table based on the mass and two-dimensional parameters of the ramp; This is the gear correction coefficient, with a value range of [0,1]. The lower the gear, the smaller the correction coefficient, meaning a smaller torque threshold, a later termination at the end of the first stage, and a smoother clutch disengagement process. In this embodiment, in 1st gear... 16th gear Time threshold Based on the preset response characteristics of the clutch actuator, in this embodiment .

[0031] If the end condition of the first stage is not met, return to step S4 to continue executing the first stage clutch target torque control. At the same time, step S3 continuously iterates and updates the engine requested torque to form a closed-loop dynamic coupling. If the end condition of the first stage is met, proceed to step S5.

[0032] According to an embodiment of the present invention, in step S5, the second stage completes the rapid disengagement of the clutch, and adaptively adjusts the target clutch torque according to the shift load state. The shift load status is determined by the shift type. and ramp The decision is made jointly, as shown in the following formula: (5); in, This indicates the lookup strategy selected based on the shift type.

[0033] The design principle is: Flat road or uphill driving conditions (not in power-free upshifting mode): The clutch is fully disengaged. This refers to the torque at the engagement point; Downhill driving conditions or no-power upshift mode: The clutch remains partially engaged to neutralize the wheel drag torque.

[0034] When the second-stage clutch target torque output is completed and the engine torque unloading reaches the target value, the system ends the current shift coordination control and enters the disengagement and subsequent shift execution stage.

[0035] Example 2 like Figure 2 As shown in the illustration, this embodiment details an adaptive control method for engine torque unloading during AMT shifting. The method is based on a feedforward-feedback composite control architecture and achieves precise and smooth engine torque unloading through multi-dimensional parameter fusion and real-time closed-loop correction.

[0036] The system uses a 10ms control cycle and synchronously collects the following input information via the vehicle's CAN bus: Vehicle estimated mass The unit is kg, which is estimated in real time through a longitudinal dynamics model with an update cycle of 100ms. Road slope The unit is °. It is estimated by fusing longitudinal acceleration sensor data with GPS elevation information, and the estimation accuracy is controlled within ±0.5°. Engine actual torque The unit is , The instantaneous value of the actual engine torque sampled at the start of the unloading action is estimated and output through the torque model inside the engine ECU; Current gear This value is obtained through the AMT transmission control unit and is a discrete integer. Throttle opening The value is expressed as a percentage and is obtained from the accelerator pedal position sensor.

[0037] The system estimates the mass of the vehicle. and road slope Using the input parameters, the mass-ramp joint correction coefficient is obtained by querying a preset two-dimensional lookup table. The horizontal axis of the two-dimensional lookup table represents vehicle mass, ranging from 0 to 50,000 kg, while the vertical axis represents road gradient, ranging from -15° to +15°. The design logic for this coefficient is: the greater the vehicle mass or the greater the road gradient (positive values ​​indicate uphill), the greater the driving resistance torque, and the higher the correction coefficient. A larger value results in a higher torque reduction slope, which overcomes greater driving resistance torque and avoids clutch slippage or shift shock caused by insufficient torque unloading. In this embodiment, The value range is [0.5, 2.0].

[0038] The system uses the actual engine torque at the start of the unloading action. Query the preset one-dimensional mapping table to obtain the initial torque correction coefficient. The design principle of this coefficient is as follows: the smaller the initial torque, the smaller the correction coefficient value, to slow down the torque reduction rate under low torque conditions and prevent unnecessary torque fluctuations or jerking; the larger the initial torque, the larger the correction coefficient value, to accelerate the unloading process under high torque conditions. In this embodiment, The value range is [0.3, 1.5], and the input torque range covers... .

[0039] The system will calculate With the calculated The smaller of the two values ​​is taken as the safety correction factor, as shown in equation (6) below: (6); The core objective of this strategy is to establish a safety lower limit constraint through the initial torque coefficient when there are estimation errors or delays in gradually changing parameters such as vehicle mass and gradient, effectively preventing issues caused by these parameters. Excessive values ​​can lead to excessively high torsional slope, ensuring smoothness of the unloading process and system robustness.

[0040] The system depends on the current gear. Query the preset basic torsional slope mapping table to obtain The design principle of the mapping table is as follows: the higher the gear, the greater the inertia of the transmission system, and the larger the value of the basic torque reduction slope, in order to achieve faster torque unloading that matches the inertia of the transmission system; the lower the gear, the smaller the value of the basic torque reduction slope, ensuring smooth unloading under low gear, high gear ratio conditions. In this embodiment, the mapping table covers gears 1 to 16, and the output... Units are .

[0041] The system uses the current throttle opening. and initial torque Using the input parameters, a two-dimensional lookup table is used to obtain the throttle-initial torque coupling correction coefficient. The horizontal axis of the two-dimensional lookup table represents the throttle opening. The range covers 0% to 100%, with the vertical axis representing the initial torque. , range coverage The revised rule is: under the same initial torque, the larger the throttle opening, the higher the coefficient. The larger the initial torque, the greater the coefficient; under the same throttle opening, the greater the initial torque. The larger the value, the better. This achieves a comprehensive response to both the driver's intentions and the actual load conditions. In this embodiment, The value range is [0.6, 1.8].

[0042] The system integrates the coefficients calculated above to calculate the dynamic torsional slope reduction. As shown in equation (7): (7); in, The base torque reduction slope, the value of which depends on the current gear. The value was obtained by looking up the preset mapping table. The design principle is: the higher the gear, the larger the value of the basic torque reduction slope, so as to achieve faster torque unloading that matches the inertia of the transmission system. The mass-gradient correction coefficient is obtained through a two-dimensional lookup table using the estimated vehicle mass and road gradient as input parameters. The design logic of this coefficient is as follows: the greater the vehicle mass or the greater the road gradient, the larger the correction coefficient value, thereby increasing the torque reduction slope to overcome greater driving resistance torque and avoid clutch slippage or shift shock caused by insufficient torque unloading. The initial torque correction factor is based on the actual engine torque at the start of the unloading action. The design principle is determined by referring to a table: the smaller the initial torque, the smaller the correction coefficient, in order to slow down the rate of torque reduction under low torque conditions and prevent unnecessary torque fluctuations or jerking. As the safety correction factor after minimum value arbitration, the system adopts the minimum value selection arbitration strategy to adjust the mass-ramp correction coefficient. With initial torque correction factor The two values ​​are compared, and the smaller value is taken as the final correction factor for that part. The core purpose of this strategy is to form a safety lower limit constraint through the initial torque coefficient when there are estimation errors or delays in gradually changing parameters such as vehicle mass and gradient, effectively preventing errors caused by these factors. Excessive values ​​can lead to excessively high torsional inclination, thus ensuring a smooth unloading process. The throttle-initial torque coupling correction coefficient is obtained through a two-dimensional lookup table using the current throttle opening and initial torque as inputs. This model aims to precisely cover nonlinear operating conditions such as small throttle opening and high load torque. The correction rule is: under the same initial torque, the larger the throttle opening, the higher the coefficient. The larger the initial torque, the greater the coefficient; under the same throttle opening, the greater the initial torque. The larger the value, the better. This enables a comprehensive response to both driver intent and actual load conditions, allowing for more refined optimization across the entire operating range. This is a feedback correction coefficient for the engine speed change rate. This coefficient is dynamically adjusted based on the real-time calculated engine speed change rate. Its core control logic is: when a continuous upward trend in engine speed is detected... At that time, the correction factor should be increased appropriately. This actively increases the torque reduction slope. This accelerates the torque unloading process, effectively shortens the total power interruption time, and improves shift response speed.

[0043] To ensure safety under extreme operating conditions, the system incorporates a dynamically reduced torsional slope after fusion. Apply safety boundary constraints: If Then let ;like Then let .in and Based on the engine characteristics and the transmission system's load-bearing capacity, this embodiment... , .

[0044] The system calculates the dynamic torsional slope reduction. Update the engine requested torque in an iterative manner. As shown in equation (8): (8); in, Request torque for the engine in the current control cycle. The actual engine torque sampled during the current control cycle. The dynamic torsional slack for the current control cycle. To control the cycle, in this embodiment By integrating gear position, mass, gradient, throttle, initial torque and engine speed change rate, and introducing the Min function, an adaptive and robust engine torque unloading rate decision core is formed, ensuring that the torque reduction process is both fast and smooth in various complex scenarios such as rapid acceleration under heavy load and coasting under light load.

[0045] The system determines whether engine torque unloading is complete, where the completion condition is the actual engine torque. Not greater than the preset torque reduction target value ,Right now . Based on the adaptive settings of the working conditions, in this embodiment If unloading is complete, the final engine requested torque is output; if unloading is incomplete, engine speed change rate feedback correction is performed. When unloading is determined to be complete, the system outputs the final engine requested torque. End this engine torque unloading control. This refers to the engine's requested torque during the current control cycle, obtained through iterative calculation. .

[0046] Example 3 like Figure 3 As shown, this embodiment provides an AMT shift coordination control system that implements the above control method, including: The multi-source information acquisition module is used to collect road conditions, vehicle operating parameters, and driver input information; The engine torque calculation module adopts a feedforward-feedback composite control architecture to execute the engine requested torque calculation logic. The clutch torque calculation module executes the two-stage clutch target torque calculation logic. The actuator control module sends control commands to the engine ECU and the clutch actuator respectively, based on the calculated engine requested torque and clutch target torque. Status feedback module: Real-time acquisition of the actual operating status of the engine and clutch, and feedback to the engine torque calculation module and clutch torque calculation module to form closed-loop control.

[0047] This system adopts a hierarchical control architecture, which is divided into an input layer, a computing layer and a physical layer. The layers interact with each other via a CAN bus to ensure the real-time performance and reliability of control commands.

[0048] The above embodiments are merely preferred technical solutions of the present invention and should not be considered as limitations on the present invention. The scope of protection of the present invention should be limited to the technical solutions described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A method for unloading engine torque and disengaging the clutch, characterized in that, Includes the following steps: S1. The engine requested torque is calculated using a feedforward-feedback composite control architecture. The feedforward-feedback composite control architecture includes: calculating the dynamic torque reduction slope based on multi-dimensional feedforward parameters, and coupling the engine speed change rate feedback correction coefficient in real time, and obtaining the engine requested torque through iterative updates. S2. The first stage of calculating the clutch target torque based on the engine request torque includes: generating the clutch feedforward target torque, introducing a decay factor that dynamically changes according to the engine unloading process, and dynamically updating the clutch request torque through an iterative formula to achieve dynamic coupling between the clutch disengagement rate and the engine torque unloading process. S3. After the end conditions of the first stage are met, the target torque of the clutch is adaptively adjusted according to the shift load state in the second stage to complete the rapid disengagement of the clutch.

2. The method for engine torque unloading and clutch disengagement according to claim 1, characterized in that, In step S1, calculating the requested engine torque specifically includes: According to the current gear Obtaining the basic torsional slope ; Based on vehicle mass and road slope Obtain the quality-ramp correction factor ; Based on the initial torque Obtain the initial torque correction coefficient ; According to throttle opening and initial torque Obtain the throttle-initial torque coupling correction coefficient ; Based on engine speed change rate Obtain the feedback correction coefficient for the rate of change of rotational speed ; Calculate the dynamic torsional slope using the following formula : ； Iterative update of engine requested torque using the following formula : ； in, Request torque for the engine in the current control cycle. This represents the actual engine torque from the previous control cycle. To control the cycle.

3. The method for unloading engine torque and disengaging clutch according to claim 1, characterized in that the steps are as follows: In S1, the mass-ramp correction factor With the initial torque correction coefficient The two values ​​are compared, and the smaller value is taken as the safety correction factor. Used to participate in dynamic torsional slope reduction The calculation.

4. The method for engine torque unloading and clutch disengagement according to claim 1, characterized in that, In step S2, the first stage of calculating the target clutch torque specifically includes: Calculate the offset coefficient using the following formula : ； in, This is the maximum torque value of the clutch. This is the engine's maximum torque. This is a correction term for operating conditions with relatively low initial torque; Calculate the clutch feedforward target torque using the following formula : ； in, Request torque for the engine; Introducing a decay factor for the engine torque unloading process The clutch torque request is updated iteratively using the following formula. : ； in, Request torque for the clutch in the current control cycle. The clutch requests torque for the previous control cycle. Furthermore, it dynamically maps the process based on the real-time progress of engine torque unloading: the initial unloading stage. The value is relatively large, and it increases as the uninstallation process progresses. Monotonically decreasing, as unloading nears completion The value is significantly reduced.

5. The method for engine torque unloading and clutch disengagement according to claim 1, characterized in that, In step S3, the first stage termination condition includes: actual engine torque. Less than the set torque threshold Furthermore, the clutch disengagement action lasts for more than a set time threshold. ; Torque threshold Calculate using the following formula: ； in, To be based on quality and slope The base torque value determined by referring to the table. This is the gear correction factor.

6. The method for engine torque unloading and clutch disengagement according to claim 5, characterized in that, Gear Correction Coefficient The value range is [0,1], and the lower the gear, the better. The smaller the value, the longer the timing of the first phase ends.

7. The method for engine torque unloading and clutch disengagement according to claim 1, characterized in that, In step S3, the second stage of the clutch target torque is calculated using the following formula: ； That is, according to the shift type Select the corresponding lookup function, based on road slope. To obtain the target clutch torque; in flat or uphill mode and not in power-free upshift mode, The torque is less than the torque corresponding to the clutch engagement point; this applies to downhill driving conditions or when upshifting without power. It is greater than the torque corresponding to the clutch engagement point.

8. The method for engine torque unloading and clutch disengagement according to claim 1, characterized in that, In step S3, the multi-dimensional feedforward parameters include: gear position, vehicle mass, road gradient, initial torque, and throttle opening.

9. An engine torque unloading and clutch disengagement system for implementing the method of any one of claims 1 to 8, characterized in that, include: The multi-source information acquisition module is used to collect road conditions, vehicle operating parameters, and driver input information; The engine torque calculation module adopts a feedforward-feedback composite control architecture to execute the engine requested torque calculation logic. The clutch torque calculation module executes the two-stage clutch target torque calculation logic. The actuator control module sends control commands to the engine ECU and clutch actuator respectively based on the calculated engine requested torque and clutch target torque; The status feedback module collects the actual execution status of the engine and clutch in real time and feeds it back to the engine torque calculation module and clutch torque calculation module to form a closed-loop control.

10. An engine torque unloading and clutch disengagement system according to claim 9, characterized in that: A hierarchical control architecture is adopted, including an input layer, a computing layer, and a physical layer, with data exchange between the layers via a CAN bus.

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