AMT clutch starting control method, system and vehicle

Abstract

The application provides an AMT clutch starting control method, system and vehicle, belongs to the technical field of commercial vehicle control, and is based on starting clutch torque and combines clutch transmission torque curves under different oil temperatures to optimize PID control parameters in a clutch actuator; when a target vehicle meets starting conditions, target torque of clutch control is determined; starting actions are performed according to selected driving modes, combined with throttle opening degree, throttle change rate signals and target torque, closed-loop adjustment torque of the clutch is analyzed, and the clutch actuator is controlled to operate through the optimized PID control parameters. The application increases the correction of the clutch stroke position on the PID parameters, optimizes the I parameter adjustment range, realizes accurate control of the clutch position, reduces the wear of the clutch, and improves the service life of the clutch.

Description

Technical Field

[0001] This invention belongs to the field of commercial vehicle control technology, and particularly relates to an AMT clutch start-up control method, system and vehicle. Background Technology

[0002] With the booming development of the vehicle transportation industry, people are paying more and more attention to the performance of vehicles in all aspects. The smoothness of vehicle start-up is an important evaluation indicator for vehicles matched with AMT transmissions, and how to control the clutch disengagement and engagement speed is the difficulty of this evaluation indicator. As the market share of AMT in heavy commercial vehicles continues to increase, more and more users are choosing AMT commercial vehicles. However, the operating conditions of heavy commercial vehicles are harsh and complex. Automatic start-up can reduce the driving difficulty for drivers. During automatic start-up, excessively fast or slow clutch control can cause changes in the load on the transmission system, and at the same time, speed fluctuations can generate shocks, causing vehicle vibration and affecting the driving experience.

[0003] An existing AMT vehicle start-up control method controls both the engine and clutch. Clutch control employs a front-start (FF) + PI (Pi) control approach. However, this method only considers throttle parameters as the primary control parameter for calculating the target speed during the engine control phase, neglecting the adjustment of engine control based on different starting gears. In the FF + PI clutch control, only throttle adjustment is considered, without taking into account the throttle change rate or user-demanded mode adjustments. Therefore, this control method cannot adapt engine speed control to different starting gears during the start-up phase, resulting in inconsistent speed difference control and clutch torque across gears. This makes it difficult to meet the smoothness and comfort requirements of users starting in different gears and fails to recognize the user's actual acceleration and deceleration needs using the accelerator pedal. Summary of the Invention

[0004] This invention provides an AMT clutch start-up control method. The method can execute different clutch start-up controls based on signals such as driving mode, throttle opening, and throttle change rate, adjust the target torque of clutch start-up control, realize multiple start-up modes, and improve start-up smoothness.

[0005] The methods include: S101: Based on the accelerator pedal opening and starting gear as the main parameters, and taking into account the weights of parameters such as ambient temperature, vehicle load, ambient atmospheric pressure, and slope, the engine request speed is adjusted. Based on the starting clutch torque and combined with the clutch transmission torque curve at different oil temperatures, the PID control parameters in the clutch actuator are optimized. S102: When the vehicle meets the starting conditions, determine the target torque for clutch control; S103: executing a starting action according to the selected driving mode in combination with the accelerator opening, accelerator change rate signal and target torque, analyzing the closed-loop adjustment torque of the clutch, and controlling the operation of the clutch actuator through the optimized PID control parameters.

[0006] It should be further noted that the method further defines sections of accelerator pedal opening, including small accelerator opening, medium accelerator opening and large accelerator opening; under the same accelerator opening section, an engine speed request is determined according to the ratio of the current gear speed ratio to the 1st gear basic speed ratio.

[0007] It should be further noted that in step S103, PID processing is performed based on the difference between the requested engine speed and the actual engine speed in combination with the torque transmission capacity of the clutch, so as to obtain the closed-loop adjustment torque of the clutch.

[0008] It should be further noted that in the method, the basic target torque for starting clutch control is obtained by adding the open-loop adjustment torque and the closed-loop adjustment torque.

[0009] It should be further noted that in step S103, the basic target torque for clutch starting control is adjusted according to the driving mode, the accelerator opening and the accelerator change rate signal, and adjustment proportion Q is set for different driving modes.

[0010] It should be further noted that the setting modes of the requested clutch target torque for different starting modes are as follows: when the accelerator opening > 0 and the accelerator change rate is greater than a preset calibration value N1, Torqueclu=basic target torque*a*Q; when the accelerator opening > 0 and 0 < accelerator change rate < N1, Torqueclu=basic target torque*b*Q; when the accelerator opening > 0 and the accelerator change rate < 0, Torqueclu=basic target torque*c*Q.

[0011] It should be further noted that the PID control parameters in the optimized clutch actuator in step S101 further include: obtaining the duty cycle parameter for controlling the solenoid valve based on the target position of the clutch, the actual position of the clutch fed back by the position sensor, and determining the PID control parameters according to the difference between the target position and the actual position of the clutch and the stroke position of the clutch; driving the clutch actuator through duty cycle voltage.

[0012] the present invention further provides an AMT clutch starting control system, which comprises: a clutch, an accelerator, a clutch actuator and an AMT controller; The AMT controller optimizes the PID control parameters in the clutch actuator based on the starting clutch torque and the clutch transmission torque curves at different oil temperatures. When the target vehicle meets the starting conditions, determine the target torque for clutch control; The AMT controller, based on the selected driving mode, combines the throttle opening and throttle change rate signals with the target torque to execute the starting action, analyzes the closed-loop adjustment torque of the clutch, and controls the operation of the clutch actuator through optimized PID control parameters.

[0013] It should be further noted that this also includes: position sensors and solenoid valves; The AMT controller determines the PID control parameters based on the clutch target position, the actual clutch position fed back by the position sensor, and the clutch travel position, thereby obtaining the duty cycle parameters of the control solenoid valve. The clutch actuator is driven by the duty cycle voltage.

[0014] The present invention also provides a vehicle including an AMT clutch start control system.

[0015] As can be seen from the above technical solutions, the present invention has the following advantages: The AMT clutch start-up control method and system provided by this invention can control the engine speed request based on signals such as actual engine speed, throttle opening, and current gear, to determine the basic target of clutch start-up control. Based on signals such as driving mode, throttle opening, and throttle change rate, the basic torque is adjusted to ensure a smooth transition of the target torque at different throttle openings and throttle change rates during start-up, thus determining the clutch torque slope and improving start-up smoothness. During the control execution process, this invention uses a clutch torque transmission capacity-position model under different oil temperatures to avoid variations in clutch torque transmission capacity due to temperature, and also achieves fine-grained clutch torque control under different ambient temperatures. Furthermore, it adds correction to PID parameters based on clutch travel position and optimizes the I-parameter adjustment range to achieve precise clutch position control, while also reducing clutch wear and extending clutch lifespan. Attached Figure Description To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 Here is a flowchart of the AMT clutch start-up control method; Figure 2A flowchart for establishing the clutch torque transmission curve of the present invention; Figure 3 This is a schematic diagram of PID control for a clutch actuator. Detailed Implementation

[0017] The AMT clutch start-up control method and system provided by this invention mainly aims to solve the problem that excessively fast or slow clutch control during automatic start-up can cause changes in transmission system load, and simultaneously, speed fluctuations can generate shocks, resulting in vehicle vibration and affecting the driving experience. The start-up control method and system involved in this invention can be based on in-vehicle intelligent control technology, combined with PID closed-loop control to acquire and process start-up-related data.

[0018] The starting control method and system utilizes an AMT controller or a corresponding processor to control the engine speed request based on signals such as the actual engine speed, throttle opening, and current gear, to determine the basic target of clutch starting control. Based on signals such as driving mode, throttle opening, and throttle change rate, the basic torque is adjusted to ensure a smooth transition of the target torque at different throttle openings and throttle change rates during the starting process, and the clutch torque slope is determined to improve starting smoothness.

[0019] The AMT clutch start-up control method and system provided by this invention require the cooperation of vehicle sensors, on-board dedicated intelligent chips, distributed storage, big data processing technology, operation / interaction systems, mechatronics, and other technologies during execution. It also incorporates one or more programming languages, or combinations thereof, to write computer program code for executing the operations disclosed herein. These programming languages ​​include, but are not limited to, object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as C or similar languages. This allows for precise control of clutch torque under different ambient temperatures, based on a clutch torque transmission capability-position model at different oil temperatures, thus meeting vehicle start-up requirements.

[0020] Of course, the AMT clutch start-up control method and system of this invention can be applied to one or more vehicles. The vehicle has a device capable of automatically performing numerical calculations and / or information processing according to pre-set or stored instructions. Its hardware includes, but is not limited to, microprocessors, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), digital signal processors (DSPs), embedded devices, etc. By analyzing the target torque of the clutch control, combining the throttle opening and throttle change rate signals with the target torque, the start-up action is executed. Furthermore, by knowing the clutch travel position and correcting the PID parameters, smooth start-up is ensured, which has a positive effect on reducing clutch wear.

[0021] 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.

[0022] Please see Figures 1 to 3 The diagram shows a flowchart of an AMT clutch start-up control method in a specific embodiment. The method determines the target torque and torque slope of the start-up clutch based on signals such as accelerator pedal opening, accelerator pedal slope, brake, brake pedal slope, gear position, and oil temperature, so as to achieve precise control of the clutch position, thereby improving start-up smoothness; at the same time, it can reduce clutch wear and increase clutch service life.

[0023] Specifically, in this embodiment, the PID control parameters of the clutch actuator are first optimized. The optimization method is to optimize the PID control parameters of the clutch actuator based on the starting clutch torque and the clutch engagement position determined by the clutch transmission torque curve under different oil temperatures.

[0024] As an example, optimizing the PID control parameters of a clutch actuator can be achieved by: determining the PID control parameters based on the clutch target position, the actual clutch position fed back by the position sensor, the difference between the clutch target position and the actual position, and the clutch travel position; obtaining the duty cycle parameters of the control solenoid valve; and driving the clutch actuator through the duty cycle voltage.

[0025] Thus, this embodiment adds the correction of PID parameters based on the clutch stroke position. The duty cycle output is controlled according to the current position of the clutch in the entire stroke, thereby solving the problem of control curve deformation caused by uneven force during clutch engagement and disengagement.

[0026] In the starting clutch torque control method of this embodiment, when the target vehicle meets the starting conditions, the open-loop adjustment torque of the clutch is obtained based on the accelerator pedal opening and the actual engine speed; PID processing (i.e., PID proportional-integral-derivative processing) is performed based on the engine requested speed, the actual engine speed, and the clutch torque transmission capability to obtain the closed-loop adjustment torque of the clutch; the open-loop adjustment torque and the closed-loop adjustment torque are added together to obtain the basic target torque for starting clutch control.

[0027] As an example, to ensure smooth clutch engagement and disengagement during gear shifting, reduce clutch and solenoid valve wear, and increase clutch lifespan, this embodiment adjusts the range of integral action. Compared to traditional control strategies where the I-value participates in calculations throughout the entire clutch control process (which can affect clutch control response speed and lead to overshoot and oscillation at small deviations), this embodiment adjusts the range of I-parameter action. This allows for a reduction in the I-parameter effect when the difference between the actual and target positions narrows to a certain range. Through P and D parameters, rapid and stable control at the target position is achieved.

[0028] This embodiment also performs different clutch start-up controls based on driving mode and signals such as throttle opening and throttle change rate, adjusts the target torque of clutch start-up control, realizes multiple start-up modes, and improves start-up smoothness.

[0029] In this embodiment, during execution, the clutch torque slope is determined based on the clutch target torque of the start request and the accelerator pedal opening, and the clutch transmission torque is controlled to change according to the calibrated slope.

[0030] The method for establishing the clutch torque transmission curve involved in this embodiment is as follows: the clutch torque transmission characteristics are learned during vehicle operation, the clutch torque transmission characteristic curve is obtained based on oil temperature, and the clutch target position is obtained based on the clutch requested target torque, engine reference torque, and the clutch torque transmission characteristic curve at the current oil temperature; in this way, a fixed torque-clutch position model is no longer used, avoiding the clutch's torque transmission capability being affected by temperature, so as to meet the requirement of accurate control of clutch torque under different ambient temperatures.

[0031] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0032] Further, as a refinement and expansion of the specific implementation of the above embodiment, in order to fully illustrate the specific implementation process of this embodiment, a specific example of an AMT clutch starting control method is provided, the method comprises: Step S11, the engine requested speed takes accelerator pedal opening and starting gear as main parameters, and the engine requested speed is adjusted according to the weights of parameters such as ambient temperature, vehicle load, ambient atmospheric pressure and gradient.

[0033] Wherein, engine EngReq = idle speed point + EngDrv, wherein the accelerator pedal opening EngDrv is adjusted according to the accelerator pedal and the current gear, the accelerator pedal opening is divided into 3 sections, namely small, medium and large accelerator opening, and the basic engine speed request EngDrv_base determined by the first gear speed ratio is shown in the following table:

[0034] Finally, EngDrv is determined according to the ratio of the starting gear to the first gear speed ratio, and the formula adopted is as follows: EngDrv= EngDrv_base * starting gear speed ratio / first gear speed ratio.

[0035] Step S12, acquire the current actual engine speed and accelerator pedal opening to obtain the requested clutch open-loop adjustment torque value, and finally obtain the open-loop adjustment torque of the clutch.

[0036]

[0037] Note: X: accelerator pedal opening; Y: actual engine speed Step S13, perform PID processing based on the difference between the requested engine speed and the actual engine speed and the torque transmission capacity of the clutch, that is, obtain the closed-loop adjustment torque of the clutch through proportional-integral-derivative processing.

[0038] Step S14, adding the open-loop adjustment torque and the closed-loop adjustment torque to obtain the basic target torque for starting clutch control.

[0039] In this embodiment, the driving mode of this embodiment and signals such as accelerator opening and accelerator change rate adjust the basic target torque for clutch starting control, the adjustment proportion of different driving modes is Q, so as to obtain the requested clutch target torque for different starting modes.

[0040] The specific processing method is as follows: When accelerator opening >0 and accelerator change rate is greater than a certain calibration value N1, Torqueclu=basic target torque*a*Q; When accelerator opening >0 and 0<accelerator change rate<N1, Torqueclu=basic target torque*b*Q; When throttle opening > 0 and throttle change rate < 0, Torqueclu = base target torque * c * Q; The values ​​of a, b, c, Q, and N1 are not fixed and can be calibrated according to the specific vehicle. Clutch control based on the target torque enables multiple starting methods and improves starting smoothness.

[0041] Step S15: Determine the clutch torque slope based on the clutch target torque and accelerator pedal opening requested for starting, and control the clutch to transmit torque according to the calibrated slope. In the early idle travel stage, the initial slope is large to ensure that the kisspoint is quickly passed and the slip phase is entered; at the same time, when the requested clutch torque is large, the slope is small to ensure the engine response speed.

[0042]

[0043] Note: X: Accelerator pedal opening; Y: Requested clutch target torque Step S16: During vehicle operation, the clutch torque transmission characteristics are learned. The clutch torque transmission characteristic curve is obtained based on the oil temperature. The clutch target position is obtained based on the clutch target torque for the start request, the engine reference torque, and the clutch torque transmission characteristic curve at the current oil temperature. This avoids the clutch's torque transmission capability being affected by temperature, so as to meet the precise control of clutch torque under different ambient temperatures.

[0044] In one embodiment of the present invention, the clutch actuator PID control method based on the AMT clutch start control method is described below as a possible embodiment with a non-limiting description of its specific implementation.

[0045] The clutch PID control system is based on the clutch target position and the actual clutch position fed back by the position sensor. It determines the PID control parameters according to the difference between the clutch target position and the actual position and the clutch stroke position, obtains the duty cycle parameters of the control solenoid valve, and drives the clutch actuator by controlling the current through the duty cycle.

[0046] In this embodiment, the clutch actuator's movement is affected by other factors, and the damping experienced during the entire disengagement or engagement process is not linear. At the beginning of disengagement, the clutch resistance is low, resulting in the fastest disengagement speed; after the free travel is eliminated, the resistance increases.

[0047] Therefore, this embodiment adds a correction to the PID parameters based on the clutch stroke position. The duty cycle output is controlled according to the current position of the clutch throughout the entire stroke, thereby solving the problem of control curve deformation caused by uneven force during clutch engagement and disengagement.

[0048] For example, the following P parameters:

[0049] Note: X: Difference between target position and actual position; Y: Clutch travel position This embodiment aims to ensure smooth clutch engagement and disengagement during gear shifting, reduce clutch and solenoid valve wear, and increase service life. The range of the integral parameter's effective range is adjusted. Traditional control strategies calculate the I-value throughout the entire clutch control process, which affects the clutch control response speed and can lead to overshoot and oscillation due to excessive adjustment at small deviations. By adjusting the difference range of the I-parameter's effective range, the effect of the I-parameter can be reduced when the difference between the actual and target positions narrows to a certain range. Through P-parameter and D-parameter control, rapid and stable control at the target position is achieved.

[0050] As an optimization measure in this embodiment, the range in which the I value participates in the calculation can be calculated based on the difference ΔD between the target position and the actual feedback position. When the difference between the target position and the actual position is less than DT, the I value output is set to 0. When ΔD is greater than DT, the D value participates in the calculation. The difference range DT in which the I parameter takes effect can be calibrated according to the actual vehicle conditions.

[0051] The following are embodiments of the AMT clutch start control system provided in this disclosure. This system and the AMT clutch start control methods in the above embodiments belong to the same inventive concept. For details not described in detail in the embodiments of the AMT clutch start control system, please refer to the embodiments of the above AMT clutch start control methods.

[0052] The system includes: clutch, throttle, clutch actuator and AMT controller.

[0053] The AMT controller optimizes the PID control parameters in the clutch actuator based on the starting clutch torque and the clutch transmission torque curves at different oil temperatures.

[0054] When the target vehicle meets the starting conditions, the target torque for clutch control is determined.

[0055] The AMT controller, based on the selected driving mode, combines the throttle opening and throttle change rate signals with the target torque to execute the starting action, analyzes the closed-loop adjustment torque of the clutch, and controls the operation of the clutch actuator through optimized PID control parameters.

[0056] The system in this embodiment also includes a position sensor and a solenoid valve.

[0057] The AMT controller determines the PID control parameters based on the clutch target position, the actual clutch position fed back by the position sensor, and the clutch travel position, thereby obtaining the duty cycle parameters of the control solenoid valve; and drives the clutch actuator through the duty cycle voltage.

[0058] The AMT clutch start-up control method provided by this invention comprises the unit and algorithm steps of various examples described in conjunction with the embodiments disclosed herein. These steps can be implemented using electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of each example have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0059] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An AMT clutch start-up control method, characterized in that, The methods include: S101: Based on the accelerator pedal opening and starting gear as parameters, and taking into account the weight of ambient temperature, vehicle load, ambient atmospheric pressure and slope, the engine request speed is adjusted. Based on the starting clutch torque and combined with the clutch transmission torque curve at different oil temperatures, the PID control parameters in the clutch actuator are optimized. S102: When the vehicle meets the starting conditions, determine the target torque for clutch control; S103: Based on the selected driving mode, combined with the throttle opening and throttle change rate signals and the target torque, it executes the starting action, analyzes the closed-loop adjustment torque of the clutch, and controls the operation of the clutch actuator through optimized PID control parameters.

2. The AMT clutch start-up control method according to claim 1, characterized in that, The method also defines the segments of accelerator pedal opening, including small accelerator pedal opening, medium accelerator pedal opening, and large accelerator pedal opening; At the same throttle opening, the engine speed request is determined by the ratio of the current gear ratio to the base gear ratio of 1st gear.

3. The AMT clutch start-up control method according to claim 1, characterized in that, In step S103, the closed-loop regulating torque of the clutch is obtained by performing PID processing based on the difference between the requested engine speed and the actual engine speed, combined with the clutch torque transmission capability.

4. The AMT clutch start-up control method according to claim 1, characterized in that, The method uses the sum of the open-loop regulating torque and the closed-loop regulating torque to obtain the basic target torque for starting clutch control.

5. The AMT clutch start-up control method according to claim 1, characterized in that, In step S103, the basic target torque for clutch start-up control is adjusted based on the driving mode, throttle opening, and throttle change rate signals, and the adjustment weight Q is set for different driving modes.

6. The AMT clutch start-up control method according to claim 5, characterized in that, The target clutch torque for different starting modes is set as follows: When the throttle opening is greater than 0 and the throttle change rate is greater than the preset calibration value N1, Torqueclu = base target torque. a Q; When the accelerator opening is > 0 and 0 < accelerator change rate < N1, Torqueclu=basic target torque b Q; When throttle opening > 0 and throttle change rate < 0, Torqueclu = base target torque. c Q.

7. The AMT clutch start-up control method according to claim 1, characterized in that, The optimization of PID control parameters in the clutch actuator in step S101 also includes: Based on the clutch target position, the actual clutch position fed back by the position sensor, and the PID control parameters determined according to the difference between the clutch target position and the actual position and the clutch stroke position, the duty cycle parameters of the control solenoid valve are obtained. The clutch actuator is driven by the duty cycle voltage.

8. An AMT clutch start control system, characterized in that, The system employs the AMT clutch start-up control method as described in any one of claims 1 to 7; the system includes: a clutch, a throttle, a clutch actuator, and an AMT controller; The AMT controller optimizes the PID control parameters in the clutch actuator based on the starting clutch torque and the clutch transmission torque curves at different oil temperatures. When the target vehicle meets the starting conditions, determine the target torque for clutch control; The AMT controller, based on the selected driving mode, combines the throttle opening and throttle change rate signals with the target torque to execute the starting action, analyzes the closed-loop adjustment torque of the clutch, and controls the operation of the clutch actuator through optimized PID control parameters.

9. The AMT clutch start control system according to claim 8, characterized in that, It also includes: position sensors and solenoid valves; The AMT controller determines the PID control parameters based on the clutch target position, the actual clutch position fed back by the position sensor, and the clutch travel position, thereby obtaining the duty cycle parameters of the control solenoid valve. The clutch actuator is driven by the duty cycle voltage.

10. A vehicle, characterized in that, Includes the AMT clutch start control system as described in any one of claims 8 to 9.

Images