Optimal Torque Distribution Strategy for Minimizing Energy Consumption of Four-wheel Independent Driven Electric Ground Vehicle

In order to improve the energy efficiency of a four-wheel independent driven ground vehicle, a vehicle model consisting of the vehicle dynamics model, in-wheel motor model and driver model is built in Matlab/Simulink and Carsim. The feasibility of the control allocation to distribute the total required torque to four in-wheel motors is analyzed and proved. Generally, motor rotation speed and torque have a great influence on the motor efficiency. Therefore, it is an effective method to improve the energy efficiency of vehicle by reasonably allocating the torque of the four in-wheel motors to make the motors work in high efficient regions. The total cost function of vehicle economy and motor torque mutation is constructed, then, the dynamic programming (DP) algorithm is adopted to obtain the optimized control instruction sequence of the motor torque. Simulation of the new control allocation algorithm is carried out on the federal test program (FTP) drive cycle and the urban new European driving cycle (NEDC). The results show that the energy consumption is significantly reduced with the proposed control allocation.