Method for precise controlling of the at shift control system

The shift comfort and efficiency of Automatic Transmission in vehicle are highly influenced by the pressure of the clutch shift control system, especially by the electro-hydraulic clutch subsystem. In this paper, the new design principles of electro-hydraulic clutch systems developed and modeled in detail, the clutch-to-clutch control system is analyzed in three time intervals: oil filled phase, changing phase of clutch torque and synchronous phase of clutch speed. The demand pressures for the engaged clutches calculated in each phase and is precisely built up by using fuzzy slide mode control, the time of hydraulic pressure building-up is very sensitive to the dither current in simulation. All control parameters are optimized by Cosimulation between software Simulink and SimulationX. Finally, the optimal algorithm of the clutch shift control is written into the transmission control unit of a testing vehicle. The testing results show that the suggested control strategy is effective.