Research On Control Strategy Of The Electric Vehicle With In-Wheel Motors

At present, among a wide range of the electric vehicle technical selections, wheel motor drive electric vehicle has become a new direction and it has gained lots of attentions from academia and engineers. In China, the research on wheel motor drive electric vehicle is in the initial stage. But because of its unique advantages, wheel motor drive electric vehicle will have broad prospects for application.in this thesis, a dynamic model with 7 freedom degrees(longititude,lateral yaw movement,and four wheels'rotation) is built, and a tire submodel based on Guo's semi-empirical exponent theory , and the DC motor model with its control system's design and validation, and the control model of slip ratio with fuzzy theory. Because the nonliner character of the tire system, the slip ratio cannot be manipulated by traditional way, the fuzzy is a good choice, in this paper, the fuzzy control system is set up and parameterized.The whole vehicle performance was simulated. Torque distribution, kinetics performance and anti-skid performance of the vehicle were specially analyzed. Wheel motor drive vehicle torque distribution control strategy which was based on the vehicle loads condition was used to distribute the vehicle torque, so the vehicle stability tolerance and tire anti-skid performance were improved.In this paper, the drive performance of wheel motor drive electric vehicle was theoretically discussed and analyzed by simulation. Some qualitative conclusions were obtained and they can be the references for the future in-depth research.