Differential Drive Based Cooperate Steering Control Strategy Considering Energy Efficiency for Multi-axle Distributed Vehicle

This chapter presents a differential drive based cooperate steering control strategy considering energy efficiency for multi-axle distributed drive vehicle. Apart from used as a fault-tolerant control method of Steer-by-Wire (SBW) system to keep stability and performance of the vehicle, the differential drive steer (DDS) can also be combined with SBW by reasonable torque allocation with considering the efficiency distribution of drive motors during normal driving. Firstly, the dynamic models of multi-axle vehicle including the front SBW system are established. Then, the upper layer path follow controller is designed based on model predictive control (MPC) with measurable disturbance to obtain the generalized steer torque. According the drive motor efficiency map, the lower layer steer axles optimal torque allocation strategy is proposed to balance the contribution of SBW motor torque and differential torque. Finally, the strategy is validated through close-loop simulation in MATLAB/Simulink. The result shows that the proposed strategy can adaptively adjust differential torque of steer axles and SBW motor torque to track the target path with better energy efficiency.