Simulation and experimental investigations on radius control of a variable pulley for the new type of electromechanical CVT system

摘要

This paper presents a method of varying CVT ratio by using a new pulley system which eliminates the axial motion of pulley. Current CVT have drawbacks with hydraulic and belt misalignment which can be solved by electromechanical system. The actuator consists of DC motor that coupled with power screw mechanism to drive slider crank mechanism for varying the radius position of sectional pulley. This approach avoids unnecessary load to the engine as in hydraulic system. The new pulley is controlled with PI controller for energising actuator, while radius position of sectional pulley uses PD controller. Simulation and experimental works are carried out in MATLAB SIMULINK where the real pulley on test rig is controlled via DAQ card. Investigation on the real pulley indicates that the implementation of CPD controller solves the irregularity of sectional pulley behaviours. The proposed CVT shows its improvement as compared with current electromechanical CVT in term of transient responses at averagely around 35% up to 63%.