Research On Starting Control Of Electric AMT Clutch

As the development of electronic control technology, people pay more attention to the intelligence and automation of the vehicle, so it’s important to improve the performance of automobile electronic control system. The control of automobile powertrain system directly affects the dynamic property, comfort and safety of driving experience. As for automatic transmission, AMT is appropriate to be developed in our country. During starting process, AMT system is needed to make the vehicle started rapidly without shock. Therefore, the engaging control of AMT clutch during starting is the key section, and also the difficult one.The structure of AMT system and the principle of the clutch which is driven by direct current motor are introduced. The deformation characteristics and the torque transfer characteristics of dry clutch with diaphragm spring are analyzed. As electric clutch, the working principle, characteristics and drive mode of electric actuator are analyzed, and the mathematical model of DC motor is built. Furthermore, the operating feature of clutch is analyzed by stages, which implied the fast-slow-fast control strategy during starting.Among all intelligent control methods, fuzzy control is more suitable for nonlinear systems to realize steady control without transfer functions. Mostly based on driver’s intention, the four-parameters fuzzy controller is designed, which controls the engaging speed in two levels. Based on mathematical models, the simulation model of the dynamic engaging process of clutch is built in MATLAB/Simulink. The engaging controls in different conditions are simulated, and the control strategy is evaluated to be effective by impact degree and work of slipping.For further test of the engaging control strategy of clutch, the clutch motor was selected, and the full-function AMT control unit circuit board is designed and manufactured, which takes MPC5634 series chip as the core. With the control unit as hardware, the vehicle test of clutch engaging control is carried out. Compared with simulation results, the clutch engaging fuzzy control strategy during starting is proved effective, which meets the starting demands in different conditions.