Friction circle estimation-based torque distribution control of six-wheeled independent driving vehicles for terrain-driving performance

This paper describes torque distribution control of six-wheeled in-wheel motor vehicles by considering the friction circle of each wheel for enhanced terrain-driving performance. Using control allocation, the proposed torque distribution algorithm determines the torque command to each wheel, by considering the size of the friction circle. The friction circle of each wheel is estimated using a linear parameterized tyre model with two threshold values. The parameters and the threshold values are computed from measurements of the wheel speed, the yaw rate, the acceleration and the torque command signals using a recursive least-squares method. Simulation studies were conducted using TruckSim and MATLAB/Simulink co-simulations. It was confirmed that the proposed friction circle estimation algorithm can be successfully used for torque distribution to enhance the terrain-driving and hill-climbing performance.