Hybrid Modeling and Simulation of Shifting Process Involving Multi-group Clutches
The characteristics of automatic transmission shifting process involving multi-group clutches were studied and it was pointed out that the shifting process is a hybrid system including a continuous system and a discrete system; then a hybrid modeling method, based on the continuous system under bond graph theory and on the discrete system under Finite State Machine, was proposed. In the paper, a model of shifting process of hydro-mechanical transmission which was equipped in the Dongfanghong 1302R rubber tracked tractor was established on the platforms of Matlab/Simulink and Matlab/Stateflow. The simulation showed that this hybrid system was rather effective in simulating the dynamic behavior of clutches in shifting process, and its influence on the shift quality was analyzed through simulation, which served as an effective tool for the design of clutch control strategy in the shifting process.