In this study, a motor torque control algorithm for improving the stability of an in-wheel electric vehicle is proposed. The longitudinal and normal forces acting on the tyre were estimated with the wheel speed, the vehicle acceleration and the motor torque, and a road friction coefficient estimation method based on these factors is suggested. Furthermore, a method for determining the control normal force of each wheel and for limiting the in-wheel motor torque is proposed by introducing the concept of virtual movement of the centre of gravity by the slip ratio. The performance of the proposed in-wheel motor torque control algorithm was validated through MATLAB/Simulink and CarSim co-simulation and real-vehicle tests. The simulations and experimental results show that the in-wheel motor torque control algorithm braked the vehicle with no spin on a slippery road.
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