Kinetic Characteristic Analysis Of Shift And Select Actuators For Automatic Mechanical Transmission

A kind of design method and process for automatic mechanical transmission shift actuation is presented in this paper. Based on the requirement of the shifting force and the national standard 28 working conditions, started from drawing up the dynamic and economic shift law which followed the prototype vehicle performance parameters, analyzed the synchronous process and affecting factors to synchronous force of gear-shifting, studied the electromechanical shift actuators of the kinematics and dynamics, then the maximum synchronous force was calculated. The parameters of the electromechanical shift actuator finally were determined. At last, kinetic characteristic of the shift and select actuators were analyzed on a simulative simulink modle to show the the effectiveness and feasibility of control strategy and the whole design method for automatic mechanical transmission shift actuation. It's a foundation for electromechanical shift actuators design of automatic transmission and AMT control algorithm formulating.To this end, several things were done based on a prototype vehicle. Specifically falls into the following points.①Introduced the structure and principle of automated mechanical transmissions. Then the development trend and present situation of research on electromechanical shift actuators were summarized.②Analyzed the stress characteristics in shifting process and got the mathematicalrelation between shifting resistances and their influencing factors. Including self-locking and interlocking resistances of the fork shafts, self-locking resistance of the synchronizing sleeve, inertia resistance piking gear, synchronizing force, inertia resistance of the drive dog.③Based on the performance of the prototype vehicle engine, according to the existing theory, general shift schedules of dynamic and economic performance were developed. Grounded on the national standard 28 working conditions and Matlab, the simulink modle was build to illustratesthe validity of the shift schedules. Futher more, synchronizing force curve and the maximum one of shiftting between adjacent gears were got from the simulation results. Besides, we can get the maximum selecting resistance by selecting process analysis.④Parametric design for the electromechanical shift actuator was done to match the maximum synchronizing force and the maximum selecting resistance. Then the make and technical parameter of the driving motors were determined.⑤Worked out a control strategy for shift and select actuators position servo-control.It contains isolated functional blocks, such as hysteresis current controller block, speed controller block, position controller block, ect.⑥Studied on the electromechanical shift actuators of the kinematics and dynamics, elected driving type PWM to drive the motors, built the actuators'simulink modle, debugged the PID controllers, the whole positional servosystem modle finally was built. By study and analysis the results of the modle, kinetic characteristics were got like shifting force, motor rotate and torque , displacement and speed respond to the actuator. The simulation results also testified the validity of the strategy and the whole design method for automatic mechanical transmission shift actuation.