Research On Transmission Shift Schedule And Shift Drive System For Light Vehicles

Retaining the traditional mechanical transmission’ advantages of low cost and simple structure,good inheritance,automatic mechanical transmission,can reduce the work intensity significantly,improve the dynamic performance and fuel economy,and has broad prospects for development.Different shift schedule for the automatic transmission vehicle are compared and analyzed,a dynamics model of light vehicle transmission system is established to analyze the shift control strategy and determine the layout scheme of electronic controlled electric quadrature shift actuator.According to the parametric design of shift actuator,the main technical indicators of the shift motor are determined.The main structure parameters of rotor and stator of shift gear motor are designed and calculated.The 2D simulation model of shift motor is established and simulated,and the chart of magnetic force lines,magnetic flux density modulus value,magnetic flux density vector and air gap flux density in the static magnetic field,and the induced electromotive force waveform in the transient magnetic field is obtained.The simulation results show that the magnetic field peak flux density of the shift gear motor is 1.41 T,that is less than the flux saturation;the induced electromotive force waveform of shift motor is sinusoidal and the harmonic content are less;the influence of the parameters of the shift motor on the cogging torque is analyzed,the maximum cogging torque of shift motor is 29.4 m N·m,which is in accordance with the design requirements of small motors.These results verify the rationality of the shift motor design from the angle of magnetic field.According to the determined shift schedule and shift control strategy,the light vehicle electric control mechanical type automatic gear drive system simulation model is established using MATLAB / Simulink,and the simulation analysis results of shift motor starting current,speed under different conditions and speed of shift gear motor in shift time,show that the control system has good current limiting protection function,and can better meet the requirements of the shift time and shift position precision.