Computer modeling of CVT ratio control system based on matlab

To simplify the modeling process and to increase accuracy and stability of CVT ratio control system, CVT transmission structure and ratio changing theory were analyzed. The mathematical model every part of control system was built. Engine simulation model and CVT object ratio simulation model based on the engine optimal-economy and the optimal-power work mode were built. CVT-vehicle model according to mass concentration method and an improved CVT ratio controller model based on the integral separation PID control method were built too. Total simulation model of CVT ratio control system was built which included five sub model. Finally, the simulation experiment of ratio control was made, which included the deceleration with 65%~15% throttle opening and the acceleration with 15%~60%. The results shown that the overshoot and the delay time of the ratio control system were shortened, CVT real ratio could follow object ratio well, ratio control performance was improved.