The Optimization Of Shifting Strategy For Electric Vehicle Equipped With AMT

Environmental protection and energy for sustainable development has become the two major themes to restrict the development of the world economy along with the exhaustion of oil resources and increasingly stringent environmental requirements automobile in the future, electric car being pushed into people’s vision,and design the special transmission for electric car has also become a hot spot. Automatic mechanical transmission has been widely used in electric vehicles.for its simple structure, reliable operation, high transmission efficiency, low cost for manufacturing and maintenance,Automatic mechanical transmission is based on the structure of manual transmission, and the TCU( Transmission Control Unit) control the shift actuator to shift automatically. In this paper, considering the wide speed range of drive motor and the characteristics of reversing for electric vehicle, combining with a two-blocks AMT with no clutch and controlled by TCU automatic transmission system for electric vehicle. The main contents and innovations are as follows:1. Based on the selection and comparative analysis for the shift driving motor of AMT, we select BDC motor as shift motor according to the shifting quality and economical design goals.2. Based on the 32-bit MPC5634 chip of Free-scale, designing the ECU for automatic transmission system:hardware system mainly contain the MPC5634 core system version, CAN communication interface circuit, serial interface circuits,H-bridge motor driver circuit, power supply circuit composition, analog interface circuits, digital signal interface circuit, the pulse signal interface circuit and thecurrent detection circuit and so on; software system includes shift control strategies under different conditions, the definition of CAN messages and CAN protocol packet transceiver process and so on.3. Based on the research of AMT power shift strategies and economy shift strategies, plotting the power shift curve and economy shift curve, modeling the subsystem of the electric vehicle on Matlab/Simulink platform,then simulink for it with ADVISOR.4. Based on the AMT control system and shift actuator, showing that engage a gear and pick neutral action can be completed stable and reliable. Based on the active speed control of drive motor. Shorten the shifting process synchronization time,thereby reducing the shift time, shift shock and sense of frustration, improving the performance of shifting comfort and ride comfort for electric vehicle.