CN117803670A - AMT clutch starting control method, system and vehicle - Google Patents

Abstract

The invention provides an AMT clutch starting control method, an AMT clutch starting control system and a vehicle, which belong to the technical field of commercial vehicle control, and are based on starting clutch torque, and the PID control parameters in a clutch executing mechanism are optimized by combining clutch transfer torque curves under different oil temperatures; when the target vehicle meets starting conditions, determining a target torque controlled by the clutch; according to the selected driving mode, starting action is executed by combining the accelerator opening degree, the accelerator change rate signal and the target torque, the closed-loop adjusting torque of the clutch is analyzed, and the operation of the clutch executing mechanism is controlled through the optimized PID control parameter. The invention increases the correction of the PID parameter by the clutch stroke position, optimizes the I parameter adjusting range, realizes the accurate control of the clutch position, can reduce the clutch abrasion and prolongs the service life of the clutch.

Description

AMT clutch starting control method, system and vehicle

Technical Field

The invention belongs to the technical field of commercial vehicle control, and particularly relates to an AMT clutch starting control method and system and a vehicle.

Background

With the vigorous development of the vehicle transportation industry, people pay more attention to the performance of vehicles in various aspects, and the vehicle starting smoothness is an important evaluation index matched with the AMT gearbox vehicle, and how to control the clutch release and combination speed is a difficulty of the evaluation index. Along with the continuous promotion of heavy commercial car AMT commercial occupancy, more and more users select AMT commercial car, and heavy commercial car's service conditions are abominable, complicated, and automatic start can reduce the driver and drive the degree of difficulty, and clutch control is too fast too slow in automatic start in-process can cause the transmission system load to change, and the rotational speed fluctuation produces the impact simultaneously, causes the vehicle shake, influences the driving impression.

According to the existing AMT vehicle starting control method, an engine and a clutch are controlled, and a control mode based on FF+PI is adopted for clutch control, but the control method only considers accelerator parameters as main control parameters calculated by target rotating speed in an engine control stage, and adjustment of engine control by different starting gears is not considered. In the ff+pi control of the clutch control, only the adjustment of the accelerator size is considered, and the adjustment of the accelerator change rate and the user demand pattern is not considered. Therefore, the control method cannot adapt to different starting gears in the starting stage of engine speed control, can cause speed difference control of different gears and keep the torque of the clutch consistent, is difficult to meet the smoothness and comfort of a user without gear starting, and cannot identify the real requirements of the user in acceleration and deceleration of an accelerator pedal.

Disclosure of Invention

The invention provides an AMT clutch starting control method, which can execute starting control of different clutches based on signals such as driving modes, accelerator opening, accelerator change rate and the like, adjust target torque of clutch starting control, realize various starting modes and improve starting smoothness.

The method comprises the following steps:

s101: based on the opening of an accelerator pedal and a starting gear as main parameters, simultaneously adjusting the engine request rotating speed according to the weights of parameters such as ambient temperature, vehicle load, ambient atmospheric pressure, ramp and the like, and based on starting clutch torque, optimizing PID control parameters in a clutch executing mechanism by combining clutch transfer torque curves under different oil temperatures;

s102: when the vehicle meets starting conditions, determining a target torque of clutch control;

s103: according to the selected driving mode, starting action is executed by combining the accelerator opening degree, the accelerator change rate signal and the target torque, the closed-loop adjusting torque of the clutch is analyzed, and the operation of the clutch executing mechanism is controlled through the optimized PID control parameter.

Further, in the method, a section of the opening of the accelerator pedal is defined, including a small section of the opening of the accelerator, a middle section of the opening of the accelerator and a large section of the opening of the accelerator;

and under the same throttle section opening, determining the engine speed request according to the ratio of the current gear speed ratio to the 1 st gear basic speed ratio.

In step S103, PID processing is performed based on the difference between the engine requested rotation speed and the engine actual rotation speed, and the torque transmission capability of the clutch is combined to obtain a closed-loop adjustment torque of the clutch.

In the method, the basic target torque of the starting clutch control is obtained based on the addition of the open-loop adjustment torque and the closed-loop adjustment torque.

In step S103, the basic target torque for clutch start control is adjusted by the driving mode and accelerator opening degree and accelerator change rate signal, and a different driving mode adjustment specific gravity Q is set.

Further, the clutch target torques required for the different starting modes are set as follows:

when the accelerator opening is greater than 0 and the accelerator change rate is greater than a preset calibration value N1, torqueclu=basic target torque a×q;

when the accelerator opening is >0, and 0< accelerator change rate < N1, torclu=base target torque×b×q;

when the accelerator opening is >0 and the accelerator change rate is <0, torqueclu=base target torque×c×q.

It should be further noted that the PID control parameters in the optimized clutch actuator in step S101 further include:

determining PID control parameters based on the clutch target position and the actual position fed back by the position sensor, and determining the duty ratio parameters of the control electromagnetic valve according to the difference value between the clutch target position and the actual position and the clutch stroke position;

the clutch actuator is driven by a duty cycle voltage.

The invention also provides an AMT clutch starting control system, which comprises: clutch, throttle, clutch actuator and AMT controller;

the AMT controller optimizes PID control parameters in a clutch executing mechanism based on starting clutch torque and combining clutch transfer torque curves under different oil temperatures;

when the target vehicle meets starting conditions, determining a target torque controlled by the clutch;

and the AMT controller executes starting action according to the selected driving mode by combining the accelerator opening degree, the accelerator change rate signal and the target torque, analyzes the closed-loop regulating torque of the clutch, and controls the operation of the clutch executing mechanism through the optimized PID control parameter.

It should be further noted that the method further includes: a position sensor and a solenoid valve;

the AMT controller determines PID control parameters based on the clutch target position and the clutch actual position fed back by the position sensor and according to the difference value between the clutch target position and the actual position and the clutch stroke position, and obtains duty ratio parameters of the control electromagnetic valve;

the clutch actuator is driven by a duty cycle voltage.

The invention further provides a vehicle, which comprises the AMT clutch starting control system.

From the above technical scheme, the invention has the following advantages:

the AMT clutch starting control method and the AMT clutch starting control system provided by the invention can control the engine speed request based on signals such as the actual engine speed, the accelerator opening, the current gear and the like, determine a basic target for clutch starting control, adjust the basic torque based on signals such as a driving mode, the accelerator opening, the accelerator change rate and the like, ensure the stable transition of target torque in different accelerator openings and accelerator change rates in the starting process, determine the clutch torque slope, and improve the starting smoothness. In the execution control process, according to the clutch torque transmission capacity-position model under different oil temperatures, the clutch torque transmission capacity difference caused by temperature is avoided, and the refined control of the clutch torque under different environment temperatures is also met. The correction of the PID parameter by the clutch stroke position is increased, the I parameter adjusting range is optimized, the accurate control of the clutch position is realized, the clutch abrasion can be reduced, the service life of the clutch is prolonged,

drawings

In order to more clearly illustrate the technical solutions of the present invention, the drawings that are needed in the description will be briefly introduced below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a flow chart of a method of AMT clutch launch control;

FIG. 2 is a clutch transfer torque curve establishment flow chart of the present invention;

FIG. 3 is a schematic diagram of PID control of a clutch actuator.

Detailed Description

The invention provides an AMT clutch starting control method and system, which mainly aim to solve the problems that the load change of a transmission system is caused by too fast and too slow clutch control in the automatic starting process, and meanwhile, the fluctuation of the rotating speed generates impact, so that the vehicle shakes and the driving feeling is influenced. The starting control method and the starting control system can acquire and process data related to starting based on a vehicle-mounted intelligent control technology and combined with PID closed-loop control.

The starting control method and system utilize an AMT controller or a corresponding processor to control the engine speed request based on signals according to the actual engine speed, the accelerator opening, the current gear and the like, determine a basic target of clutch starting control, adjust basic torque based on signals such as a driving mode, the accelerator opening, the accelerator change rate and the like, ensure stable transition of target torque in different accelerator opening and accelerator change rates in the starting process, determine clutch torque slope and improve starting smoothness.

In the execution process, the AMT clutch starting control method and the AMT clutch starting control system provided by the invention are realized by matching technologies such as a vehicle sensor, a vehicle-mounted special intelligent chip, a distributed storage technology, a big data processing technology, an operation/interaction system, an electromechanical integration technology and the like. Computer program code for carrying out operations of the present disclosure may also be written in combination with one or more programming languages, including but not limited to an object oriented programming language such as Java, smalltalk, C ++ and conventional procedural programming languages, such as the "C" programming language or similar programming languages. Therefore, the torque transmission capacity-position model of the clutch under different oil temperatures can be used for meeting the requirement of vehicle starting by achieving the refined control of the torque of the clutch under different environment temperatures.

Of course, the AMT clutch start control method and system according to the present invention may be applied to one or more vehicles having devices capable of automatically performing numerical calculation and/or information processing according to preset or stored instructions, and the hardware thereof includes, but is not limited to, a microprocessor, an Application-specific integrated circuit (SpecificIntegratedCircuit, ASIC), a programmable gate array (Field-ProgrammableGate Array, FPGA), a digital processor (DigitalSignalProcessor, DSP), an embedded device, and the like. The method comprises the steps of analyzing the target torque controlled by the clutch, executing starting action by combining the accelerator opening degree, the accelerator change rate signal and the target torque, ensuring starting smoothness by learning the correction of the PID parameter by the clutch stroke position, and having a positive effect on reducing the abrasion of the clutch.

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Referring to fig. 1 to 3, which are flowcharts illustrating a method for controlling the start of an AMT clutch according to an embodiment, the method determines a control target torque and a torque slope of the start clutch based on signals such as an accelerator pedal opening, an accelerator pedal slope, a brake pedal slope, a gear, and an oil temperature, so as to realize accurate control of a clutch position, so as to improve starting smoothness; meanwhile, the abrasion of the clutch can be reduced, and the service life of the clutch is prolonged.

Specifically, the PID control parameters of the clutch actuator are optimized first in this embodiment, wherein the optimization mode is to determine the clutch coupling position based on the starting clutch torque and the clutch transmission torque curves under different oil temperatures to optimize the PID control parameters of the clutch actuator.

As one example, the manner of optimizing the PID control parameters of the clutch actuator may include the following: and determining PID control parameters according to the difference value between the clutch target position and the actual position and the clutch stroke position based on the clutch target position and the actual position fed back by the position sensor to obtain duty ratio parameters of the control electromagnetic valve, and driving the clutch executing mechanism through the duty ratio voltage.

Therefore, the embodiment increases the correction of the PID parameter by the clutch stroke position, and controls the duty ratio output according to the position of the current clutch in the whole stroke, thereby realizing the problem of control curve deformation caused by uneven stress in the clutch disengaging and combining process.

For the starting clutch torque control method of the embodiment, when the target vehicle meets the starting condition, the open-loop adjustment torque of the clutch is obtained based on the opening degree of the accelerator pedal, the actual rotation speed of the engine and the like; PID processing is carried out based on the engine request speed, the engine actual speed and the torque transmission capacity of the clutch, namely PID proportional integral differential processing is carried out, and the closed-loop regulating torque of the clutch is obtained; and adding the open-loop regulating torque and the closed-loop regulating torque to obtain the basic target torque of the starting clutch control.

As an example, to meet the smoothness of clutch separation and combination in the gear shifting process, the clutch and electromagnetic valve loss is reduced, the service life of the clutch is prolonged, and the embodiment can adjust the range of integral action. In the embodiment, the difference range of the I parameter is adjusted to realize that the effect of the I parameter is reduced when the difference between the actual position and the target position is reduced to a certain range, and the control on the target position is realized quickly and stably through the control of the P parameter and the D parameter.

In the embodiment, based on signals such as the driving mode, the accelerator opening, the accelerator change rate and the like, different clutch starting control is executed, the target torque of the clutch starting control is adjusted, various starting modes are realized, and starting smoothness is improved.

In the execution process of the embodiment, the clutch torque slope is determined based on the clutch target torque requested by starting and the opening degree of the accelerator pedal, and the clutch transmission torque is controlled to change according to the calibrated slope.

The clutch transfer torque curve establishment method related to the embodiment comprises the following steps: the method comprises the steps of learning torque transmission characteristics of a clutch in the running process of a vehicle, acquiring a torque transmission characteristic curve of the clutch based on oil temperature, and acquiring a target position of the clutch based on a target torque requested by the clutch, a reference torque of an engine and the torque transmission characteristic curve of the clutch under the current oil temperature; in this way, a fixed torque-clutch position model is no longer used, avoiding the difference in the ability of the clutch to transfer torque as a function of temperature, to meet the need for accurate control of clutch torque at different ambient temperatures.

It should be understood that the sequence number of each step in the foregoing embodiment does not mean that the execution sequence of each process should be determined by the function and the internal logic, and should not limit the implementation process of the embodiment of the present invention.

Further, as a refinement and extension of the specific implementation manner of the foregoing embodiment, in order to fully describe the specific implementation process in this embodiment, a specific AMT clutch start control method example is provided, where the method includes:

step S11, the engine requested rotation speed is based on the accelerator pedal opening and the starting gear as main parameters, and the engine requested rotation speed is adjusted according to the weights of the parameters such as the ambient temperature, the vehicle load, the ambient atmospheric pressure, the ramp, and the like.

The engine engreq=idle 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 a small accelerator, a medium accelerator and a large accelerator, and the basic rotation speed request EngDrv is determined according to a 1-gear speed ratio as follows basically:

the final EngDrv is determined from the ratio of starting gear to 1 gear ratio using the following formula:

engdrv=engdrv basically the starting gear ratio/1 gear ratio.

And step S12, acquiring the current actual rotation speed of the engine and the opening degree of an accelerator pedal to obtain a requested clutch open-loop adjustment torque value, and finally obtaining the clutch open-loop adjustment torque.

Note that: x is the opening degree of an accelerator pedal; y: actual engine speed

And step S13, PID processing is performed on the basis of the difference between the engine request speed and the engine actual speed and the torque transmission capacity of the clutch, namely, the closed-loop adjustment torque of the clutch is obtained through proportional-integral-derivative processing.

And S14, adding the open-loop adjustment torque and the closed-loop adjustment torque to obtain a basic target torque of the starting clutch control.

In the embodiment, the driving mode, the accelerator opening, the accelerator change rate and other signals are used for adjusting the basic target torque of clutch starting control, and the specific gravity of adjustment of different driving modes is Q, so that the requested clutch target torque of different starting modes is obtained.

The specific processing mode is as follows:

when the accelerator opening is greater than 0 and the accelerator change rate is greater than a certain calibration value N1, torqueclu=basic target torque a×q;

when the accelerator opening is >0, and 0< accelerator change rate < N1, torclu=base target torque×b×q;

when the accelerator opening is >0 and the accelerator change rate is <0, torqueclu=base target torque Q;

a. the value of b, c, Q, N1 is not fixed unique and can be calibrated for a particular vehicle. The clutch is controlled based on the target torque, so that various starting modes are realized, and starting smoothness is improved.

Step S15, determining a clutch torque slope based on a clutch target torque required by starting and an accelerator pedal opening, controlling the change of the clutch transmission torque according to a calibrated slope, wherein the initial slope is large in an early idle stroke stage, ensuring that the clutch transmission torque quickly passes over a kisspeoint point, and entering a slip stage; meanwhile, when the torque of the requested clutch is larger, the slope is small, so that the response speed of the engine is ensured.

Note that: x is the opening degree of an accelerator pedal; y: requested clutch target torque

Step S16, the torque transmission characteristic of the clutch is learned in the running process of the vehicle, a torque transmission characteristic curve of the clutch is obtained based on the oil temperature, and a target position of the clutch is obtained based on the target torque of the clutch requested by starting, the reference torque of the engine and the torque transmission characteristic curve of the clutch under the current oil temperature; this condition avoids the clutch from being affected by temperature and has different torque transmitting capacities so as to meet the requirement of achieving accurate control of the clutch torque at different ambient temperatures.

In one embodiment of the present invention, a PID control mode of the clutch actuator based on the AMT clutch start control method is given below as one possible example for non-limiting illustration of a specific implementation thereof.

The clutch PID control system determines PID control parameters according to the difference between the clutch target position and the actual position and the clutch stroke position based on the clutch actual position fed back by the clutch target position and the position sensor, obtains the duty ratio parameters of the control electromagnetic valve, and drives the clutch executing mechanism through the duty ratio control current.

In this embodiment, the clutch actuator action is affected by other factors and the damping of the motion throughout the decoupling or coupling process is not linear. When the separation is just started, the resistance of the clutch is small, and the separation speed is the fastest; the drag increases after the idle stroke is eliminated.

Therefore, the embodiment increases the correction of the clutch stroke position to the PID parameter, and controls the duty ratio output according to the position of the current clutch in the whole stroke, thereby realizing the problem of control curve deformation caused by uneven stress in the clutch disengaging and combining process.

For example the following P parameters:

note that: x is the difference between the target position and the actual position; y: clutch travel position

In order to meet the smoothness of clutch separation and combination in the gear shifting process, the clutch and solenoid valve loss is reduced, the service life is prolonged, the integral acting range is adjusted, the I value in the whole clutch control process participates in calculation in the traditional control strategy, the response speed of clutch control can be affected, the adjustment energy is too strong in small deviation, and overshoot and oscillation phenomena are caused. By adjusting the range of the difference value acted by the I parameter, the effect of reducing the I parameter can be realized when the difference value between the actual position and the target position is reduced to a certain range, and the control on the target position can be quickly and stably realized through the control of the P parameter and the D parameter.

As an optimization measure of the present embodiment: the interval of the I value participating in the operation can be calculated according to the target position and the actually fed back position difference value delta D. When the difference value between the target position and the actual position is smaller than DT, the I value output is set to 0, when DeltaD is larger than DT, the D value participates in operation, and the difference value range DT acting on the I parameter can be calibrated according to the actual vehicle condition.

The following is an embodiment of an AMT clutch start control system provided by the embodiments of the present disclosure, which belongs to the same inventive concept as the AMT clutch start control method of the above embodiments, and in details of the embodiment of the AMT clutch start control system, reference may be made to the embodiment of the AMT clutch start control method.

The system comprises: clutch, throttle, clutch actuator and AMT controller.

The AMT controller optimizes PID control parameters in the clutch executing mechanism based on starting clutch torque and combining clutch transfer torque curves under different oil temperatures.

When the target vehicle satisfies the start condition, a target torque of the clutch control is determined.

And the AMT controller executes starting action according to the selected driving mode by combining the accelerator opening degree, the accelerator change rate signal and the target torque, analyzes the closed-loop regulating torque of the clutch, and controls the operation of the clutch executing mechanism through the optimized PID control parameter.

In the system of this embodiment, further includes: position sensor and solenoid valve.

The AMT controller determines PID control parameters based on the clutch target position and the clutch actual position fed back by the position sensor and according to the difference value between the clutch target position and the actual position and the clutch stroke position, and obtains duty ratio parameters of the control electromagnetic valve; the clutch actuator is driven by a duty cycle voltage.

The AMT clutch launch control method provided by the present invention is the unit and algorithm steps of each example described in connection with the embodiments disclosed herein, and can be implemented in electronic hardware, computer software, or a combination of both, and 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 such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended 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 (10)

1. An AMT clutch start control method, comprising:

s101: based on the opening of an accelerator pedal and a starting gear as parameters, simultaneously adjusting the engine request rotating speed according to the weights of the parameters such as the ambient temperature, the load of a vehicle, the ambient atmospheric pressure, a ramp and the like, and based on the torque of a starting clutch, optimizing PID control parameters in a clutch executing mechanism by combining clutch transmission torque curves under different oil temperatures;

s102: when the vehicle meets starting conditions, determining a target torque of clutch control;

s103: according to the selected driving mode, starting action is executed by combining the accelerator opening degree, the accelerator change rate signal and the target torque, the closed-loop adjusting torque of the clutch is analyzed, and the operation of the clutch executing mechanism is controlled through the optimized PID control parameter.

2. The AMT clutch starting control method as claimed in claim 1, wherein,

the method further defines a section of the accelerator pedal opening, including a small section opening of the accelerator, a middle section opening of the accelerator and a large section opening of the accelerator;

and under the same throttle section opening, determining the engine speed request according to the ratio of the current gear speed ratio to the 1 st gear basic speed ratio.

3. The AMT clutch starting control method as claimed in claim 1, wherein,

in step S103, PID processing is performed based on the difference between the engine requested rotation speed and the engine actual rotation speed, and the torque transmission capability of the clutch is combined, so as to obtain the closed-loop adjustment torque of the clutch.

4. The AMT clutch starting control method as claimed in claim 1, wherein,

in the method, the basic target torque of the starting clutch control is obtained based on addition of the open-loop adjusting torque and the closed-loop adjusting torque.

5. The AMT clutch starting control method as claimed in claim 1, wherein,

in step S103, the basic target torque for clutch start control is adjusted based on the driving mode, the accelerator opening degree, and the accelerator change rate signal, and a different driving mode adjustment specific gravity Q is set.

6. The AMT clutch launch control method as claimed in claim 5, wherein,

the clutch target torques required for the different starting modes are set as follows:

when the accelerator opening is greater than 0 and the accelerator change rate is greater than a preset calibration value N1, torqueclu=basic target torque a×q;

when the accelerator opening is >0, and 0< accelerator change rate < N1, torclu=base target torque×b×q;

when the accelerator opening is >0 and the accelerator change rate is <0, torqueclu=base target torque×c×q.

7. The AMT clutch starting control method as claimed in claim 1, wherein,

the PID control parameters in the optimizing clutch actuator in step S101 further include:

determining PID control parameters based on the clutch target position and the actual position fed back by the position sensor, and determining the duty ratio parameters of the control electromagnetic valve according to the difference value between the clutch target position and the actual position and the clutch stroke position;

the clutch actuator is driven by a duty cycle voltage.

8. An AMT clutch start control system, characterized in that the system employs the AMT clutch start control method as claimed in any one of claims 1 to 7; the system comprises: clutch, throttle, clutch actuator and AMT controller;

the AMT controller optimizes PID control parameters in a clutch executing mechanism based on starting clutch torque and combining clutch transfer torque curves under different oil temperatures;

when the target vehicle meets starting conditions, determining a target torque controlled by the clutch;

and the AMT controller executes starting action according to the selected driving mode by combining the accelerator opening degree, the accelerator change rate signal and the target torque, analyzes the closed-loop regulating torque of the clutch, and controls the operation of the clutch executing mechanism through the optimized PID control parameter.

9. The AMT clutch start control system as claimed in claim 8, wherein,

further comprises: a position sensor and a solenoid valve;

the AMT controller determines PID control parameters based on the clutch target position and the clutch actual position fed back by the position sensor and according to the difference value between the clutch target position and the actual position and the clutch stroke position, and obtains duty ratio parameters of the control electromagnetic valve;

the clutch actuator is driven by a duty cycle voltage.

10. A vehicle comprising an AMT clutch launch control system as claimed in any one of claims 8 to 9.