Research On Control Method Of Gear Shifting Quality For Integrated Transmission

Shift quality control is one of the most important technologies in the control of vehicular integrated transmission assembly.The shift quality will not only impact the comfortness but also affect the lifetime of the transmission parts.This thesis focuses on the integrated transmission of a military track vehicle.An optimal control method is proposed considering the shift quality of each phase during the whole shift process and verified by real vehicle test results.A dynamic model of the entire vehicle powertrain system including the engine,torque converter,integrated transmission,and vehicle load was established.The shift quality requirements of the research object in each stage of the shift process were analyzed.The relation between the clutch oil pressure and the speed and torque of the power transmission system proposes the inertial and torque phase control targets.The proportional solenoid valve model in the electro-hydraulic shift control system based on test data was established by using parameter identification method.The dynamic model including the bilateral throttle valve and the clutch piston chamber was established by combining the CFD simulation results with the system dynamics equation.Established the objective function including the impact degree and sliding friction work in the shift process,and comprehensively analyzed the relationship between shifting torque and rotational torque in the torque phase and the inertia phase.A shift-quality segmented optimal controller for the shift process was established.The simulation results show that the proposed optimal control strategy can effectively meet the shift quality requirements of the integrated transmission and enable the vehicle to achieve a fast and smooth shift.Using a certain tracked vehicle to perform shift quality real vehicle test,the proposed shift quality optimal control strategy was applied to real vehicle shift quality control through rapid prototyping,and the shift quality control strategy proposed in this paper was conducted using experimental results.Verification results show that this piecewise optimal control strategy can achieve good shift quality.