Development of intelligent electromagnetic continuously variable transmission

Abstract

A continuously variable transmission (CVT) system transmits the engine power to the car driving wheel smoothly and efficiently. Several types of CVT already been developed to improve the transmission losses while maintaining the acceleration time. However, most of the CVT has some constraints in the actuation mechanism which led us to develop an innovative electromagnetic actuator for CVT. An analytical model of the electromagnetic actuated of the CVT is developed by deep analysis on the kinematics of the CVT clamping forces and electromagnetic forces of the electromagnetic actuator (EMA). The speed sensor and throttle position sensor will be used to determine the targeted CVT ratio. The Crankshaft Position Sensor (engine RPM), the CVT Pulley Position Sensor, and the CVT Secondary Pulley Revolution Sensor is used to determine the actual CVT ratio. Based on the error, i.e. the different between and targeted and actual ratio, the fuzzy logic controller (FLC) then makes appropriate adjustments of the CVT by controlling the power supply to the EMA. This study introduced fuzzy intelligent system to predict the EMA system dynamic behaviour in order to regulate the current supply for the EMA actuation during operation of the CVT. The power supply will be controlled with FLC and digital control switching system to set the targeted CVT gear ratio. There is a failsafe mode built into the CVT to prevent damage in case some of the sensors malfunction. During failsafe mode, the system shifted to manual mode for fixing the gear ratio equivalent to first gear and to save the CVT from damage by the central manual switching system. It is observed that time taken to accelerate the car in the range of 5-7 sec. The EMA develops the electromagnetic force in the ranged of 185-266 N for the supply current in the range of 3-3.7 amps.