An Adaptive Shift Control Method for Planetary Integrated Transmission Device

Abstract

This invention belongs to the field of integrated transmission for tracked vehicles, specifically relating to an adaptive shifting control method for a planetary integrated transmission device. It is the first to address how to utilize speed signals to achieve adaptive adjustment control during the rapid oil filling and emptying phase. A control algorithm based on feedforward and feedback is developed. The feedforward control calculates initial control parameters based on clutch structural parameters and the characteristics of the electro-hydraulic shifting control loop. The feedback algorithm adaptively adjusts the initial control parameters by monitoring the actual oil filling and emptying process and updates the control parameters in the feedforward control for the next preparation phase. In the torque phase, model reference adaptive control is employed. By comparing the actual control results with the reference model output, the deviation in performance indicators is used to generate an adaptive law through a nonlinear feedback adaptive controller to adjust the initial control parameters. In the inertial phase, derivative-leading PID control is used to improve shifting quality control.

Description

Technical Field

[0001] This invention belongs to the field of integrated transmission for tracked vehicles, and specifically relates to an adaptive shifting control method for a planetary integrated transmission device. Background Technology

[0002] Integrated transmission systems combine mechanical, electrical, and hydraulic characteristics, exhibiting complex logical operations and numerous and diverse system state variables, thus exhibiting the fault characteristics of large and complex systems. During gear shifting, considering different faults and performance degradation under service conditions, and to maximize shifting functionality and ensure shifting quality while maintaining the speed sensor's integrity, an adaptive control strategy based on a closed-loop speed control is proposed.

[0003] Because the electro-hydraulic shift quality control system is a typical nonlinear, time-varying system, torque phase control is affected by many factors, including the variation of transmission input torque with engine and torque converter characteristics, the impact of oil temperature changes on hydraulic system stiffness, damping ratio, and natural frequency, the variation of clutch plate friction coefficient with the speed difference between the driving and driven sides, clutch plate wear, and variations in road loads. All these factors influence the shift control process. The entire shift process is divided into several stages: the rapid oil charging / discharging stage, the torque phase stage, and the inertia phase stage.

[0004] To address uncertainties such as clutch wear and oil pressure changes, closed-loop adaptive adjustment can be achieved through speed signals during the torque and inertia phases. However, the rapid oil filling and discharging phase has open-loop characteristics, and simple calibration for control can easily lead to shocks or clutch slippage. This invention provides a planetary integrated transmission device shift control strategy that utilizes speed signals to achieve adaptive control during the rapid oil filling and discharging phase, thereby improving shift quality. Summary of the Invention

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

[0006] Step S1: During the rapid charging / discharging phase, a first duty cycle charging control command with a duty cycle of 100% is used to continuously charge / discharge for the first rapid charging / discharging time length t. f1 Then; with the second duty cycle oil filling control command D b1 The second duty cycle is less than the first duty cycle;

[0007] Monitor the rate of change of turbine shaft speed. When it drops to the first threshold, confirm that the gap between the clutch master and slave friction plates has been eliminated and enter the torque phase stage.

[0008] Step S2: During the torque phase, the filling slope α1 at the given initial clutch oil pressure rise rate and the discharge slope β1 at the given clutch oil pressure fall rate are measured over the first torque phase time length t. t1 Then, the oil filling rate was changed to α2 until the speed difference of the clutch to be separated was detected to be out of range or the time length t of the second torque phase was reached. t2 If separation still does not occur, continue to fill with oil at the stated oil filling slope α1 until the torque phase ends;

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

[0010] Specifically, in step S1, when the oil filling control command is given with the second duty cycle, the valve core of the double-sided throttle valve is controlled to return from the rightmost opening of 100% to near the zero position; the rate of increase of the clutch working pressure is reduced, and the clutch master and slave friction plates are continuously pushed until the gap between the clutch master and slave friction plates is eliminated.

[0011] Specifically, for the turbine shaft speed signal n t After filtering, differential processing is performed. When the clutch to be engaged begins to transmit torque, the rate of change of the turbine shaft speed decreases by a certain threshold. At that time, it was assumed that the free clearance between the clutch master and slave friction plates had been eliminated.

[0012] Specifically, in step S2, the speed difference of the clutch to be separated exceeding the range specifically includes: the input shaft speed of the clutch to be separated being higher or lower than the maximum allowable value of the output shaft speed.

[0013] Specifically, in step S1, the initial control parameters are calculated using a feedforward control algorithm based on the clutch structural parameters and the characteristics of the electro-hydraulic shift control loop; the initial control parameters include: the initial 100% duty cycle oil filling time t. f1 Low duty cycle fuel filling command D b1 and pre-drainage control command D a1 ;

[0014] Feedback control adjusts the 100% duty cycle fuel filling time t based on real-time oil temperature and engine speed. f1 Low duty cycle fuel filling command D b1 Perform adaptive correction.

[0015] Specifically, in step S3, when slippage of the clutch to be disengaged is detected, the inertial phase begins, and in the initial stage t of the inertial phase... i1The control objective is to control the second-order decrease in the speed difference of the clutch to be engaged, and to gradually increase the rate of change of the speed difference of the clutch to be engaged; when the decrease in the speed difference of the clutch to be engaged reaches a preset threshold a... i t i1 2 At that time, start controlling the speed difference of the clutch to be engaged 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 At this point, the inertial phase ends; the rate of change of the speed difference of the clutch to be engaged is gradually reduced to zero; when the transmission speed ratio is detected to be equal to the target gear ratio, the inertial phase ends; the electro-hydraulic proportional valve is fully opened, allowing the clutch to be engaged to reliably engage, completing the gear shifting operation, where a i and c i For time parameters, t i1 t represents the initial stage time of the inertial phase. i3 This indicates the end time of the inertial phase.

[0016] Beneficial effects:

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

[0018] Smooth gear shifting: Multi-stage control and adaptive adjustment effectively avoid shocks and slippage, improving the smoothness of gear shifting.

[0019] It has strong adaptability, and through feedforward and feedback control algorithms, as well as model reference adaptive control, it improves the system's adaptability under different operating conditions.

[0020] Optimized control, through PID control and adaptive adjustment strategies, has improved the control process and ensured the continuous stability of shift quality. Attached Figure Description

[0021] Figure 1 This is a flowchart illustrating the adaptive control process during the oil filling and discharging phase of the present invention.

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

[0023] Figure 3 This is a flowchart of the inertial phase control process of the present invention. Detailed Implementation

[0024] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0025] This invention provides a planetary integrated transmission device that, based on sensor malfunction, obtains target gear information by looking up a table using current gear, throttle opening, and vehicle speed information. Then, according to a gear management strategy, it employs an adaptive control method to ensure vehicle operation and safety. Figure 1 As shown. Its gear management strategy process is as follows:

[0026] Step S1: Rapid fuel filling and discharging stage. Fuel is filled at 100% duty cycle for a period of time t. f1 Then, a control command D with a lower duty cycle is given. b1 This allows the valve core of the dual-sided throttle valve to return from its rightmost position to near zero, reducing the rate of increase in clutch working pressure to a controllable level while ensuring that the clutch piston continuously pushes the master and slave friction plates to eliminate free play. (Regarding the turbine shaft speed signal n...) t After filtering, differential processing is performed. When the clutch to be engaged begins to transmit torque, the rate of change of the turbine shaft speed decreases by a certain threshold. At that time, it is believed that the free clearance between the clutch driving and driven plates, i.e., the driving and driven 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 filling time is too long, meaning the actual filling process is faster than the preset 100% duty cycle filling time, the clutch to be engaged has already begun transmitting torque before the initial filling command is completed, and the turbine speed change rate begins to decrease. The initial rapid filling time t is adjusted by monitoring the advance of the actual filling completion moment. f1 Make corrections and reduce t. f1 When the 100% duty cycle filling time is too short, that is, the actual filling process is slower than the preset 100% duty cycle filling time, t f2 Larger than ideal, relying on low duty cycle fuel filling command D b1 The extension means that the clutch only begins to transmit torque after engagement. Similarly, by monitoring the actual oil filling completion time and the preset oil filling completion lag, the relationship between t and the actual oil filling completion time can be improved. f1 Make corrections and increase t. f1 .

[0028] The low duty cycle control command is used to precisely control the working pressure corresponding to the initial torque transmission after the clutch oil chamber is fully filled, and to return the spool valve from its rightmost position to its equilibrium position. The low duty cycle command value is D. b1 Both excessively high and excessively low duty cycle commands can negatively impact clutch engagement. When the low duty cycle command is too high, the steady-state pressure in the clutch oil chamber becomes too high after the friction plates eliminate free play, causing shift shock. The low duty cycle command D should be lowered. b1 If the turbine shaft speed change rate is not detected after the low duty cycle command has been applied for more than a certain time threshold t*, it indicates that the initial low duty cycle control command D... b1The duty cycle is too low, which cannot guarantee that the clutch piston can overcome the spring force and eliminate free travel. The low duty cycle command D should be increased. b1 .

[0029] Step S2: Torque phase stage. (e.g.) Figure 2 As shown, the initial slope of torque phase oil filling and discharging is obtained based on theoretical calculations and experience. Oil is filled with a constant slope of α1 and with a slope of β. l Oil release with constant slope t t1 After a certain time, oil is added at a constant slope of α2 until the speed difference of the clutch to be disengaged is monitored to exceed the maximum allowable value of the input shaft speed being higher or lower than the output shaft speed of the clutch to be disengaged, such as within the ideal range [-Δω]. lim ,+Δω lim Or after time t t2 If the clutch still does not disengage, continue to fill with oil at a small slope α1 until the torque phase is detected to end. During this period, the oil discharge slope remains unchanged.

[0030] When the disengagement of the clutch to be disengaged is detected, the error between the slope of the rate of change of the speed difference of the clutch to be disengaged and the ideal range is used to determine whether it is a significant power interruption or a "dual-gear" condition where both gears are engaged simultaneously. The allowable range for the rate of change of the speed difference of the clutch to be disengaged is set as follows: The error of torque phase control is defined as:

[0031]

[0032] When the rate of change of the speed difference of the clutch to be disengaged exceeds the allowable range, the following measures are adopted: The adaptive adjustment mechanism corrects the rise slope α2 of the oil-filled duty cycle; when the rate of change of the speed difference of the clutch to be disengaged is within the allowable range, there is no need to correct the rise slope α2 of the oil-filled duty cycle, i.e. Ultimately, this achieves the goal of adjusting the torque phase charging and discharging oil slope.

[0033] Step S3: Inertial Phase Stage. The inertial phase control flowchart is as follows: Figure 3 As shown, the initial stage primarily aims for a smooth transition with torque, with the rate of change of the clutch speed difference decreasing from zero at a constant slope, i.e., the clutch speed difference decreasing as a second-order function. The intermediate stage's main task is to eliminate the clutch speed difference, aiming for a constant slope decrease in the clutch speed difference. The final stage's main task is to smoothly transition with the shift completion stage, aiming for the rate of change of the clutch speed difference to smoothly decrease from the constant slope value of the intermediate stage to zero. An ideal clutch speed difference change trajectory is proposed.

[0034] Furthermore, in step S1, a control algorithm based on feedforward and feedback is formulated during the preparation stage. The feedforward control algorithm calculates the initial control parameters based on the clutch structure 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 phase calculates initial control parameters based on the clutch structural parameters and the characteristics of the electro-hydraulic shift control loop, including the 100% duty cycle oil filling time t. f1 Low duty cycle fuel filling command D b1 and pre-drainage control command D a The feedback control algorithm during the preparation phase monitors the oil temperature and engine speed in real time during each filling operation, with only a 100% duty cycle filling time t. f1 and low duty cycle fuel filling command D b1 The oil filling process is greatly affected by different operating conditions; pre-discharge command D a1 The goal is simply to eliminate the influence of the reserve coefficient; precise control is not required. Therefore, only t needs to be considered. f1 and D b1 Make corrections.

[0036] Furthermore, in step S2, during the torque phase, the oil filling duty cycle rise slope α2 is corrected according to an adaptive algorithm to adjust the oil filling and discharging slope of the torque phase, such as... Figure 2 As shown, this adaptive control strategy formulates control rules based on a quadratic function of the error of the speed difference change rate of the clutch to be separated, ensuring that the error between the actual value and the reference target value is asymptotically convergent, and the control system meets the stability requirements.

[0037] Furthermore, in step S3, when slippage of the clutch to be separated is detected, the inertial phase begins, and in the initial stage t of the inertial phase... i1 With the second-order decrease of the speed difference of the clutch to be engaged as the control objective, the rate of change of the speed difference of the clutch to be engaged is gradually increased; the initial trajectory of the speed difference change of the clutch to be engaged, controlled by PID, is: -a i (t-t3) 2 +Δω C2 (t3); When the speed difference of the clutch to be engaged decreases to a preset threshold a i t i1 2 At that time, the trajectory of the speed difference change of the clutch to be engaged, controlled by PID, is 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 At that time, entering the end stage of the inertial phase, the trajectory of the speed difference change of the clutch to be engaged is controlled as c.i (t-t4) 2 When the transmission ratio is detected to be i2, the inertial phase ends.

[0038] Where a i b i and c i For time parameters, t i1 t represents the initial stage time of the inertial phase. i3 This indicates the end time of the inertial phase. When the transmission ratio is detected to be equal to the target gear ratio, the inertial phase ends, the electro-hydraulic proportional valve fully opens, and the clutch to be engaged is reliably engaged, completing the gear shift operation.

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

[0040] It will be apparent to those skilled in the art that the embodiments of the present invention are not limited to the details of the exemplary embodiments described above, and that the embodiments of the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the embodiments of the present invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the embodiments of the present invention is defined by the appended claims rather than the foregoing description. Therefore, all variations falling within the meaning and scope of equivalents of the claims are intended to be encompassed within the embodiments of the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims. Furthermore, it is clear that the word "comprising" does not exclude other units or steps, and the singular does not exclude the plural. Multiple units, modules, or devices recited in the system, apparatus, or terminal claims may also be implemented by the same unit, module, or device through software or hardware. The terms "first," "second," etc., are used to indicate names and do not indicate any particular order.

[0041] Finally, it should be noted that the above embodiments 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 embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of the embodiments of the present invention should not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An adaptive shifting control method for a planetary integrated transmission device, comprising the following steps: Step S1: During the rapid charging / discharging phase, a first duty cycle charging control command with a duty cycle of 100% is used to continuously charge / discharge for the first rapid charging / discharging time length t. f1 Then; with the second duty cycle oil filling control command D b1 The second duty cycle is less than the first duty cycle; Monitor the rate of change of turbine shaft speed. When it drops to the first threshold, confirm that the gap between the clutch master and slave friction plates has been eliminated and enter the torque phase stage. Step S2: During the torque phase, the filling slope α1 at the given initial clutch oil pressure rise rate and the discharge slope β1 at the given clutch oil pressure fall rate are measured over the first torque phase time length t. t1 Then, the oil filling rate was changed to α2 until the speed difference of the clutch to be separated was detected to be out of range or the time length t of the second torque phase was reached. t2 If separation still does not occur, continue to fill with oil at the stated oil filling slope α1 until the torque phase ends; Step S3: In the inertial phase, control the speed difference of the clutch to be engaged to decrease in a second-order function, and then control the speed difference of the clutch to be engaged to decrease at a constant slope. The speed difference change rate of the clutch to be engaged is gradually reduced to zero until the target gear ratio is reached. When the target gear ratio is reached, the proportional valve is opened to engage the clutch and complete the gear shift.

2. The adaptive shifting control method for a planetary integrated transmission device as described in claim 1, characterized in that, In step S1, when the oil filling control command is given with the second duty cycle, the valve core of the double-sided throttle valve is controlled to return from the rightmost opening of 100% to near the zero position; the rate of increase of the clutch working pressure is reduced, and the clutch master and slave friction plates are continuously pushed until the gap between the clutch master and slave friction plates is eliminated.

3. The adaptive shifting control method for a planetary integrated transmission device as described in claim 2, characterized in that, For the turbine shaft speed signal n t After filtering, differential processing is performed. When the clutch to be engaged begins to transmit torque, the rate of change of the turbine shaft speed decreases by a certain threshold. At that time, it was assumed that the free clearance between the clutch master and slave friction plates had been eliminated.

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

5. The adaptive shifting control method for a planetary integrated transmission device as described in claim 4, characterized in that: In step S1, the initial control parameters are calculated based on the clutch structure parameters and the characteristics of the electro-hydraulic shift control circuit using a feedforward control algorithm. The initial control parameters include: the initial 100% duty cycle fuel filling time t. f1 Low duty cycle fuel filling command D b1 and pre-drainage control command D a1 ; Feedback control adjusts the 100% duty cycle fuel filling time t based on real-time oil temperature and engine speed. f1 Low duty cycle fuel filling command D b1 Perform adaptive correction.

6. The adaptive shifting control method for a planetary integrated transmission device as described in claim 5, characterized in that: In step S3, when slippage of the clutch to be separated is detected, the inertial phase begins, and in the initial stage t of the inertial phase... i1 The control objective is to control the second-order decrease in the speed difference of the clutch to be engaged, and to gradually increase the rate of change of the speed difference of the clutch to be engaged; when the decrease in the speed difference of the clutch to be engaged reaches a preset threshold a... i t i1 2 At that time, start controlling the speed difference of the clutch to be engaged 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 At this point, the inertial phase ends; the rate of change of the speed difference of the clutch to be engaged is gradually reduced to zero; when the transmission speed ratio is detected to be equal to the target gear ratio, the inertial phase ends; the electro-hydraulic proportional valve is fully opened, allowing the clutch to be engaged to reliably engage, completing the gear shifting operation, where a i and c i For time parameters, t i1 t represents the initial stage time of the inertial phase. i3 This indicates the end time of the inertial phase.

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