Performance enhancement of electronic differential in electric vehicles using a novel wavelet controller

Differential in a transmission system plays an important role of preventing the vehicle from slipping on curved roads. Mechanical differentials are heavy and bulky and are not suitable for electric vehicles especially those employing separate drives for both the rear wheels. Electronic differential constitutes a technological advance in electric vehicle design enabling better stability and control of the vehicle on curved roads. This paper presents modelling and simulation of an electronic differential employing a novel wavelet controller for two brushless DC motors ensuring the drive of the two rear wheels. The proposed controller uses discrete wavelet transform to decompose the error between actual and command speed as given by the electronic differential based on throttle and steering angle as the input into frequency components. These frequency components are scaled by their respective gains to generate a control signal which is given as input to the motor. To test the system, several simulations were carried out viz. vehicle on a straight road and vehicle driven on a road turning right and left. The results and comparison with conventional controllers like PID has been presented.