Modeling and torque control for a 4-wheel-drive electric vehicle

Recent developments in control systems have made it possible to manipulate wheel torques independently in order to improve vehicle handling characteristics of electric vehicles. These vehicles usually employ in-wheel motors which can be independently controlled. This paper presents a 4-wheel-drive electric vehicle for research purposes. A dynamic model based on the connection of the mechanical devices in the vehicle is implemented as a CAD model and as a simulator using Simmechanics in the MATLAB/Simulink framework. This model is validated using data from real experiments and it can be used to test new torque controllers before their implementation. The vehicle has a real-time control system that integrates the torque controller for the 4 motors. This control system fulfils the driver´s demand computing the torque that must be supplied by each of the 4 motors. Experimental results are presented, that show that this vehicle seems to be a good test bench that can be used for testing advanced torque distribution controllers.