Self-adaptive gear shifting control method for planetary comprehensive transmission device

Abstract

The invention belongs to the field of comprehensive transmission of tracked vehicles, and particularly relates to a self-adaptive gear shifting control method of a planetary comprehensive transmission device, which aims at how to utilize a rotating speed signal to realize self-adaptive adjustment control in a rapid oil charging and discharging stage for the first time. A control algorithm based on feed-forward and feedback is formulated, and initial control parameters are calculated through feed-forward control according to clutch structure parameters and electro-hydraulic gear shifting control loop characteristics; and the feedback algorithm performs adaptive adjustment on the initial control parameters by monitoring the actual oil charging and discharging process, and updates the control parameters in the feed-forward control for the control of the next preparation stage. Model reference adaptive control is adopted in a torque phase stage, and by comparing an actual control result with reference model output, an adaptive law is generated through a nonlinear feedback adaptive controller by using deviation of performance indexes to adjust initial control parameters; and differential preceding type PID control is adopted in the inertia phase stage, and the purpose of improving gear shifting quality control is achieved.

Description

Technical Field

[0001] The invention belongs to the field of integrated transmission of tracked vehicles, and in particular relates to an adaptive shift control method for a planetary integrated transmission device. Background Art

[0002] The integrated transmission system combines the characteristics of mechanics, electricity and fluids, with complex logical operations, a large number of system state variables and a variety of types, and has the fault characteristics of a large complex system. In the process of gear shifting, in view of different faults and performance degradation under the service state, in order to maximize the shifting function and ensure the shifting quality, an adaptive control strategy for the shifting process based on the speed closed loop is proposed under the condition that the speed sensor does not fail.

[0003] Since the electro-hydraulic shift quality control system is a typical nonlinear and time-varying system, torque phase control is affected by many factors, including the change of transmission input torque with the characteristics of the engine and torque converter, the influence of oil temperature change on the stiffness, damping ratio and natural frequency of the hydraulic system, the change of clutch plate friction coefficient with the speed difference between the active and passive sides, the wear of the clutch plate, the change of different road loads, etc., which will affect the shift control process. The entire shift process is divided into multiple stages: fast filling and discharging stage, torque phase stage and inertia phase stage.

[0004] In view of uncertain factors such as clutch wear and oil pressure changes, closed-loop adaptive adjustment can be achieved through the speed signal in the torque phase and inertia phase. However, the rapid oil filling and releasing phase has an open-loop characteristic. Simple calibration for control can easily lead to impact or clutch slippage. The planetary integrated transmission device shift control strategy of the present invention utilizes the speed signal to achieve adaptive control in the rapid oil filling and releasing phase, thereby improving the shift quality. Summary of the invention

[0005] In view of this, the present invention provides a planetary integrated transmission device adaptive shift control method, comprising the following steps:

[0006] Step S1: In the rapid oil filling and discharging stage, a first duty cycle oil filling control instruction with a duty cycle of 100% is used for a first rapid oil filling and discharging time length t f1 After that, the oil filling control instruction D of the second duty cycle b1 , wherein the second duty cycle is less than the first duty cycle;

[0007] Monitor the turbine shaft speed change rate, and when it drops to the first threshold, confirm that the gap between the clutch master and slave friction plates is eliminated and enter the torque phase stage;

[0008] Step S2: In the torque phase, the first torque phase time length t is passed with a given initial clutch oil pressure rising rate filling slope α1 and a clutch oil pressure falling rate draining slope β1. t1 After that, the oil filling is changed to the oil filling slope α2 until the speed difference of the clutch to be separated is detected to be out of range or the second torque phase time length t t2 After that, the two ends are still not separated; the oil filling is continued at the oil filling slope α1 until the torque phase ends;

[0009] Step S3: In the inertia phase, the speed difference of the clutch to be engaged is controlled to decrease as a second-order function, and then the speed difference of the clutch to be engaged is controlled to decrease at a constant slope; until the speed difference change rate of the clutch to be engaged is controlled to gradually decrease to zero; when the target gear ratio is reached, the proportional valve is opened to engage the clutch to complete the gear shift.

[0010] In particular, in step S1, when the oil filling control instruction of the second duty cycle is used, the double-sided throttle valve core is controlled to return from the rightmost end opening of 100% to near zero; the rising rate of the clutch working pressure is reduced, and the master and slave friction plates of the clutch are pushed until the gap between the master and slave friction plates of the clutch is eliminated.

[0011] In particular, for the turbine shaft speed signal n t After filtering, differential processing is performed. When the clutch to be engaged starts to transmit torque, the turbine shaft speed change rate drops to a certain threshold. It is considered that the free gap between the clutch master and slave friction plates has been eliminated.

[0012] In particular, in step S2, the speed difference of the off-going clutch exceeds the range specifically includes: the speed of the input shaft of the off-going clutch is higher or lower than the maximum allowable value of the output shaft speed.

[0013] In particular, in step S1, the initial control parameters are calculated according to the clutch structure parameters and the characteristics of the electro-hydraulic shift control circuit by using a feedforward control algorithm; the initial control parameters include: the initial 100% duty cycle filling time t f1 , low duty cycle oil filling instruction D b1 And pre-release oil control command D a1 ;

[0014] Through feedback control, the 100% duty cycle oil filling time t is adjusted according to the real-time oil temperature and engine speed. f1 , low duty cycle oil filling instruction D b1 Make adaptive corrections.

[0015] In particular, in step S3, when it is detected that the clutch to be released starts to slip, the inertia phase begins. i1The second-order decrease of the speed difference of the clutch to be engaged is taken as the control target, and the speed difference change rate of the clutch to be engaged is controlled to gradually increase; when the speed difference decrease of the clutch to be engaged reaches the preset threshold a i t i1 2 When the speed difference of the clutch to be engaged is controlled to b i The slope decreases; when the speed difference of the clutch to be engaged is detected to be less than the preset value c i t i3 2 , the inertia phase ends; the speed difference change rate of the clutch to be engaged is controlled to gradually decrease to zero; when the transmission speed ratio is detected to be equal to the target gear ratio, the inertia phase ends; the electro-hydraulic proportional valve is fully opened to enable the clutch to be engaged to engage reliably and complete the shift operation, where a i and c i is the time parameter, t i1 represents the initial stage time of the inertial phase, t i3 Indicates the end time of the inertia phase.

[0016] Beneficial effects:

[0017] Through the above scheme, the present invention achieves the following technical effects in the integrated transmission system of the tracked vehicle:

[0018] Smooth gear shifting: Multi-stage control and adaptive adjustment effectively avoid impact and slippage, and improve gear shifting smoothness.

[0019] The system has strong adaptability, and its adaptability under different working conditions is improved through feedforward and feedback control algorithms, as well as model reference adaptive control.

[0020] Optimized control: Through PID control and adaptive adjustment strategies, the control process is optimized to ensure the continuous stability of shifting quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a flow chart of the adaptive control of the oil filling and discharging stages of the present invention;

[0022] Figure 2 This is a torque phase adaptive control flow chart of the present invention;

[0023] Figure 3 This is the inertia phase control flow chart of the present invention. DETAILED DESCRIPTION

[0024] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0025] The present invention provides a planetary integrated transmission device that obtains target gear information by looking up a table based on a sensor failure, according to current gear, throttle opening and vehicle speed information, and adopts an adaptive control method according to a gear management strategy to ensure the driving and safety of the vehicle, such as Figure 1 The gear management strategy process is as follows:

[0026] Step S1: Rapid oil filling and discharging stage. Fill oil at 100% duty cycle for a period of time t f1 After that, a control command D with a lower duty cycle is given. b1 , so that the valve core of the bilateral throttle valve returns to near zero position from the rightmost end, reducing the rising rate of the clutch working pressure to a controllable level while ensuring that the clutch piston always pushes the master and slave friction plates to eliminate the free gap. t After filtering, differential processing is performed. When the clutch to be engaged starts to transmit torque, the turbine shaft speed change rate drops to a certain threshold. It is considered that the free gap between the clutch active and passive plates, i.e. the master and slave friction plates, has been eliminated, and the shifting process enters the torque phase control stage from rapid oil filling.

[0027] When the 100% duty cycle oil filling time is too long, that is, the actual oil filling process is faster than the preset 100% duty cycle oil filling time, the clutch to be engaged has started to transmit torque before the initial oil filling command is completed, and the turbine speed change rate begins to decrease. The initial rapid oil filling time t is monitored by monitoring the advance amount of the actual oil filling completion time. f1 Make corrections to reduce t f1 ; When the 100% duty cycle oil filling time is too short, that is, the actual oil filling process is slower than the preset 100% duty cycle oil filling time, t f2 Larger than the ideal value, relying on low duty cycle oil filling command D b1 The clutch will start to transmit torque only after the engagement. Similarly, by monitoring the actual oil filling completion time and the preset oil filling completion hysteresis, t f1 Make corrections and increase t f1 .

[0028] The low duty cycle control command is used to accurately control the working pressure corresponding to the torque transmission after the oil chamber of the clutch to be engaged is filled, and to return the spool of the spool valve from the rightmost end to the equilibrium position. b1 Too high or too low will have an adverse effect on the clutch engagement. When the low duty cycle command is too high, the steady-state pressure of the clutch oil chamber will be too large after the friction plate eliminates the free gap, causing shift shock. The low duty cycle command D should be lowered. b1 When the action time of the low duty cycle command exceeds a certain time threshold t* and the turbine shaft speed change rate still cannot be detected to decrease, it means that the initial low duty cycle control command D b1Too low, it cannot ensure that the clutch piston overcomes the spring force to eliminate the free travel, and the duty cycle command D should be adjusted up. b1 .

[0029] Step S2: Torque phase. Figure 2 As shown in the figure, the initial slope of oil filling and discharging in the torque phase is obtained based on theoretical calculation and experience. The oil is filled with a slope of α1 and the oil is discharged with a slope of β l Equal slope oil discharge t1 After a certain time, oil is added at a constant slope of α2 until the speed difference of the clutch to be separated exceeds the maximum allowable value of the input shaft speed of the clutch to be separated is higher or lower than the output shaft speed, such as the ideal range [-Δω lim , +Δω lim ] or after time t t2 If the clutch to be separated still does not separate, oil will continue to be filled with a small slope α1 until the end of the torque phase is detected. During this period, the oil release slope remains unchanged.

[0030] When the clutch to be separated is detected, the error between the slope of the clutch speed differential change rate and the ideal change range is calculated to determine whether it is a clear power interruption or a "double gear" condition where two gears are engaged at the same time. The range of the allowable clutch speed differential change rate to be separated is set to The error of torque phase control is defined as:

[0031]

[0032] When the speed difference change rate of the clutch to be released exceeds the allowable range, the The adaptive adjustment rule is used to correct the rising slope α2 of the oil filling duty cycle; when the speed difference change rate of the to-be-released clutch is within the allowable range, there is no need to correct the rising slope α2 of the oil filling duty cycle, that is, Ultimately, the purpose of adjusting the oil charging and discharging slope of the torque phase is achieved.

[0033] Step S3: Inertia phase. The inertia phase control flow chart is as follows: Figure 3 As shown, the initial stage is mainly to smoothly transition with the torque, with the speed difference change rate of the clutch to be engaged decreasing from zero with a constant slope, that is, the speed difference of the clutch to be engaged decreases with a second-order function as the initial stage target; the main task of the intermediate stage is to eliminate the speed difference of the clutch to be engaged, with the speed difference of the clutch to be engaged decreasing with a constant slope as the target; the main task of the ending stage is to smoothly transition with the shift completion stage, with the speed difference change rate of the clutch to be engaged decreasing from the constant slope value of the intermediate stage to zero smoothly as the target, and an ideal speed difference change trajectory of the clutch to be engaged is proposed.

[0034] Furthermore, in step S1, a control algorithm based on feedforward and feedback is formulated in the preparation stage, and the feedforward control algorithm calculates the initial control parameters according to the clutch structural parameters and the characteristics of the electro-hydraulic shift control loop; the feedback algorithm adaptively adjusts the initial control parameters by monitoring the actual oil filling and discharging process, and updates the control parameters in the feedforward control algorithm for the next preparation stage control.

[0035] The feedforward control algorithm in the preparation stage calculates the initial control parameters according to the clutch structure parameters and the characteristics of the electro-hydraulic shift control loop, including the 100% duty cycle filling time t f1 , low duty cycle oil filling instruction D b1 And pre-release oil control command D a The feedback control algorithm in the preparation phase monitors the oil temperature and engine speed in real time during each oil filling. Only the 100% duty cycle oil filling time t f1 and low duty cycle oil filling command D b1 The oil filling process is greatly affected under different working conditions; the pre-discharge oil instruction D a1 It is only to eliminate the influence of the reserve factor, and there is no requirement for precise control. Therefore, it is only necessary to f1 and D b1 Make corrections.

[0036] Furthermore, in step S2, the oil filling duty cycle rising slope α2 is corrected according to the adaptive algorithm in the torque phase stage to achieve the purpose of adjusting the oil filling and releasing slope of the torque phase, such as Figure 2 As shown, this adaptive control strategy formulates control rules based on the quadratic function of the speed difference change rate error of the clutch to be released, ensuring that the error between the actual value and the reference target value converges gradually and the control system meets the stability requirements.

[0037] Furthermore, in step S3, when it is detected that the clutch to be separated starts to slip, the inertia phase begins. i1 The second-order decrease of the speed difference of the clutch to be engaged is taken as the control target, and the speed difference change rate of the clutch to be engaged is controlled to gradually increase; the initial speed difference change trajectory of the clutch to be engaged is controlled by PID as follows: i (t-t3) 2 +Δω C2 (t3); When the speed difference of the clutch to be engaged decreases to a preset threshold value a i t i1 2 When , the speed difference change trajectory of the clutch to be engaged is controlled by PID as follows: When the speed difference of the clutch to be engaged is detected to be less than the preset value c i t i3 2 When the inertia phase ends, the speed difference of the clutch to be engaged is controlled to change to ci (t-t4) 2 ; When the transmission ratio is detected to be i2, the inertia phase ends.

[0038] where a i 、b i and c i is the time parameter, t i1 represents the initial stage time of the inertial phase, t i3 Indicates the end stage time of the inertia phase. When the transmission speed ratio is detected to be equal to the target gear ratio, the inertia phase ends, the electro-hydraulic proportional valve is fully opened, and the clutch to be engaged is reliably engaged, completing the shift operation.

[0039] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0040] It is obvious to those skilled in the art that the embodiments of the present invention are not limited to the details of the above exemplary embodiments, and that the embodiments of the present invention can be implemented in other specific forms without departing from the spirit or basic features of the embodiments of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the embodiments of the present invention is limited by the attached claims rather than the above description, so it is intended to include all changes that fall within the meaning and scope of the equivalent elements of the claims in the embodiments of the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved. In addition, it is obvious that the word "comprising" does not exclude other units or steps, and the singular does not exclude the plural. Multiple units, modules or devices stated in the system, device or terminal claims can also be implemented by the same unit, module or device through software or hardware. The words first, second, etc. are used to indicate names, and do not indicate any particular order.

[0041] Finally, it should be noted that the above implementation modes are only used to illustrate the technical solutions of the embodiments of the present invention and are not intended to limit them. Although the embodiments of the present invention have been described in detail with reference to the above preferred implementation modes, those skilled in the art should understand that the technical solutions of the embodiments of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A planetary integrated transmission device adaptive shift control method, comprising the following steps: Step S1: In the rapid oil filling and discharging stage, a first duty cycle oil filling control instruction with a duty cycle of 100% is used for a first rapid oil filling and discharging time length t f1 After that, the oil filling control instruction D of the second duty cycle b1 , wherein the second duty cycle is less than the first duty cycle; Monitor the turbine shaft speed change rate, and when it drops to the first threshold, confirm that the gap between the clutch master and slave friction plates is eliminated and enter the torque phase stage; Step S2: In the torque phase, the first torque phase time length t is passed with a given initial clutch oil pressure rising rate filling slope α1 and a clutch oil pressure falling rate draining slope β1. t1 After that, the oil filling is changed to the oil filling slope α2 until the speed difference of the clutch to be separated is detected to be out of range or the second torque phase time length t t2 After that, the two ends are still not separated; the oil filling is continued at the oil filling slope α1 until the torque phase ends; Step S3: During the inertia phase, the speed difference of the clutch to be engaged is controlled to decrease with a second-order function, and then the speed difference of the clutch to be engaged is controlled to decrease with a constant slope; Until the speed difference change rate of the clutch to be engaged is controlled to gradually decrease to zero; when the target gear ratio is reached, the proportional valve is opened to engage the clutch to complete the gear shift.

2. The adaptive shift control method of a planetary integrated transmission device according to claim 1, characterized in that: In step S1, when the oil filling control instruction of the second duty cycle is used, the double-sided throttle valve core is controlled to return from the rightmost end opening of 100% to near zero; the rising rate of the clutch working pressure is reduced, and the master and slave friction plates of the clutch are pushed until the gap between the master and slave friction plates of the clutch is eliminated.

3. The adaptive shift control method of a planetary integrated transmission device as claimed in claim 2, characterized in that: The turbine shaft speed signal n t After filtering, differential processing is performed. When the clutch to be engaged starts to transmit torque, the turbine shaft speed change rate drops to a certain threshold. It is considered that the free gap between the clutch master and slave friction plates has been eliminated.

4. The adaptive shift control method of a planetary integrated transmission device as claimed in claim 3, characterized in that: In step S2, the speed difference of the clutch to be separated exceeds the range specifically includes: the speed of the input shaft of the clutch to be separated is higher or lower than the maximum allowable value of the speed of the output shaft.

5. The adaptive shift control method of a planetary integrated transmission device as claimed in claim 4, characterized in that: In step S1, initial control parameters are calculated according to clutch structural parameters and electro-hydraulic shift control loop characteristics by using a feedforward control algorithm; The initial control parameters include: initial 100% duty cycle oil filling time t f1 , low duty cycle oil filling instruction D b1 And pre-release oil control command D a1 ; Through feedback control, the 100% duty cycle oil filling time t is adjusted according to the real-time oil temperature and engine speed. f1 , low duty cycle oil filling instruction D b1 Make adaptive corrections.

6. The adaptive shift control method of a planetary integrated transmission device as claimed in claim 5, characterized in that: In step S3, when it is detected that the clutch to be released starts to slip, the inertia phase begins. i1 The second-order decrease of the speed difference of the clutch to be engaged is taken as the control target, and the speed difference change rate of the clutch to be engaged is controlled to gradually increase; when the speed difference decrease of the clutch to be engaged reaches the preset threshold a i t i1 2 When the speed difference of the clutch to be engaged is controlled to b i The slope decreases; when the speed difference of the clutch to be engaged is detected to be less than the preset value c i t i3 2 , the inertia phase ends; the speed difference change rate of the clutch to be engaged is controlled to gradually decrease to zero; when the transmission speed ratio is detected to be equal to the target gear ratio, the inertia phase ends; the electro-hydraulic proportional valve is fully opened to enable the clutch to be engaged to engage reliably and complete the shift operation, where a i and c i is the time parameter, t i1 represents the initial stage time of the inertial phase, t i3 Indicates the end time of the inertia phase.

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