Study on adverse effect suppression of hub motor driven vehicles with inertial suspensions

Abstract

With increasingly severe energy supply and environmental pollution, Hub Motor Driven Vehicle (HMDV) have become the ideal configuration for future electric vehicles. The adverse effect caused by the significant increase in HMDV unsprung mass directly affects the vehicle ride comfort and handling stability, becomes a technical bottleneck for theoretical research and industrial development to be solved urgently. The HMDV adverse effect should be suppressed by the vehicle suspension system, which can be classified as vertical motion inertia instability caused by the increase of unsprung mass, but the lack of inertial elements in the conventional suspension “damping-spring” structure restricts the overall performance of the suspension. Therefore, the inertial suspension containing the inertial element “inerter” is utilized to effectively distribute the HMDV vertical motion inertia to suppress its adverse effects. First, the adverse effects of increased unsprung mass on vehicle ride comfort and road friendliness are studied. Then, the inertial suspension models of different structures are established and their impedance expressions are derived. Thirdly, the impact of the inertance in the inertial suspension on the suppression of the HMDV adverse effect is studied. Finally, the particle swarm optimization algorithm is utilized to optimize the parameters of the inertial suspension to improve the performance of the suspension. The results show that the inertial suspension can reduce the RMS value of body acceleration and dynamic tire load. The RMS value of body acceleration and dynamic tire load of the L4 structure is reduced by 8.1% and 16.38% respectively. It shows that the inertial suspension can effectively suppress the HMDV vertical adverse effect, improve the HMDV ride comfort and road friendliness, and lay the foundation for the subsequent suppression research.