Drive shaft torque estimation for electric vehicles

The drive shaft torque information is important for the vehicle longitudinal speed control and regenerative braking control. In this paper a drive shaft torque estimator based on feedback linearization theory is proposed as torque signal is seldom measured but estimated in the production vehicle. A longitude vehicle dynamics model is established in MATLAB/Simulink environment and a model-based estimator is designed to deal with the parameters drift problem and effectiveness of the observer is tested through simulation experiments under urban road driving cycle conditions.