Study Of Complete Torque Shifting Control For Clutchless AMT Of Electric Vehicles

Traditional control method applied on clutchless AMT is based on control of driving motor's modes,and it has been applied successfully.But its feature limits futher enhancement of shift quality.Based on the National Science and Technology Support Plan Project “Develop of Electric Bus and Reasearch on Key Technologies for Industrialization”,this paper proposes the complete torque shifting control method for clutchless AMT,and launchs researches around it in depth.The researches include the propose of complete torque shifting control method,tracking on the target position for shifting motor,optimal control of shifting processes,optimization of shift schedule,etc.The main works include:Construct the models of clutchless AMT's shift component,the driving motor and the drivetrain.The model of transmission system considers the elasticity and damping of the drive shaft and the shaft,and it provides the basis for subsequent researches.The complete torque shifting control method is proposed.Shifting process is divided into six processes,including torque unloading,disengagement,electronic synchronization,mechanical synchronization,engagement and torque rebuilding process.Then put forward the shift performance evaluation parameters,and analyzes the influence on shift quality of each shifting process.Then in-depth analysis of the dynamic of six shifting process is executed,and the characteristics of each shifting process are studied.The influence on the shifting process by the throttle opening,the initial speed difference and the road gradient is analyzed.CMAC-PID control method is used for position tracking control of shift motor.The method adaptive change control parameters,so it improves the anti-interference ability of the shifting motor control.It meets the needs of the disengagement process and engagement process.The torque unloading porcess,the electronic synchronization process,the mechanical synchronization process and the torque rebuilding process have different characteristics.Based on the optimal control algorithm,objective functions including different control targets are built.Then the optimal trajectories are achieved and the influence on the trajectories caused by different weight proportion of the control targets is studied.Based on fuzzy recognition algorithm,the driver's acceleration intention is recognized.The recognized result is imported to the control of shifting process.It will meet the demand of power performance when the driver wants to accelerate,and meet the demand of confort when the driver drives gently.Aim at the particular motor's efficiency MAP,the dynamic programming method is used to optimize the working point of driving motor.Through reasonable choosing of gear,the drive motor will work more in high efficient area.Optimized shift schedule make the vehicle more energy efficiency,and the driving range is incresed.A gradient estimation method based on Luenberger state observer is designed.Its structure is simple,and the estimation error is small.The gradient can be estimated based on the existing informations.Modified shift schedule according to the estimation results will avoid the cyclic shift in uphill condition.The clutchless AMT powertrain prototype is developed and the gear position judgement method is studied based on x-y type shift component.The hardware and software of TCU are developed,and the corresponding host computer softwares are proposed.Then,the bench test for reliability is excuted,and the whole test includes 15000 times.Finally,static shifting and dynamic shifting test on electric bus are executed.Also another test using the electirc bus equiped with AMT which adoped the mode shifting control method is rasied.The test results are used to confirm the feasibility,relibility of the complete torque shifting control method and improve of the quality of shifting process.