Study of the electro-hydraulic control system for CVT metal belt axial-misalignment

Axial misalignment of metal steel belt will lead to shifting and addition abrasion between belt and pulley, affecting the transmission performance, efficiency, and reliability of metal belt type CVT. After deeply analyzing the reasons of the belt misalignment for metal belt type CVT, an electro-hydraulic control system has been designed to eliminate the belt misalignment. The belt misalignment control strategy for metal belt type CVT has been put forward, and the mathematical model of the electro-hydraulic control system has been established. Then, a Fuzzy PID controller has been designed, the simulation and experiment of the belt misalignment have been carried out, the results show that the electro-hydraulic control system and the fuzzy controller with parameter self adjustment could not only control ratio, which had a higher accuracy of the stable state and a stronger robust of the driving condition, but also eliminated the belt misalignment, improved the dynamic performance of metal belt type CVT.