Research on the ratio control of Metal Belt CVT

The Metal Belt CVT as vehicle´s ideal transmission has extensive development future and market space. When compared with the widely used automatic transmission (AT), it has many advantages, such as the performance is good, the structure is simple, the price is low and can realize vehicle´s continuously variable speeds. Speed ratio control is one of the key technologies. This paper introduces CVT development condition, internal actuality and development trend. It establishes engine simulation model, CVT-power train simulation model and ratio control with PID method model, and combines them together to get the Matlab Simulink model of CVT with PID control method. Then towards CVT at ramp starting and circulation working condition and proceeding contrast simulation analyses, check speed ratio PID controller´s control effect.