Analyze Of The Vertical Vibration And Structure Optimization For The In-wheel Motor Electric Vehicle

Facing with challenge of the world-wide environmental pollution and energy crisis, electric vehicle will be one of the best choices for automotive industry in the future. As a unique development direction of electric vehicles, the in-wheel motor electric vehicle(IWM-EV) has a series of advantages such as high transmission efficiency, good fuel economy and great controllability, etc. Therefore, it is widely noticed and specially considered to be the final drive form. However, the significant increase of unsprung mass and the special torque fluctuation of IWM worsen the vertical performance of vehicle. Aiming at this problem, this dissertation carries on a series of research work which are shown as follows:① According to given parameters, establish a 1/4 vehicle vibration model and analyze the effect of the increased unsprung mass and special torque fluctuation of IWM to the IWM-EV under different road condition with different speed, then deal with the simulation results in time domain and frequency domain.② Adopting the principle of dynamic absorber, install suspension components to “suspend” the IWM and thus design the vibration-depressing in-wheel drive system. Then, make a contrast among three types of IWM-EV with suspension components in different position of the vehicle, and analyze the result, in order to select the best structure with good damping effect and easy implementation, for IWM-EV. Besides, the sensitivity of vertical vibration response of IWM-EV is also analyzed.③ In order to improve the coefficient of performance and reduce the quality for the IWM, adopt the fuzzy optimization method to optimize the size parameters of IWM. On this basis, with the main goal of decreasing acceleration and dynamic wheel road of the vehicle, use “optimizing method” to optimize the stiffness and damping parameters of the IWM mounts, and then carry out simulation process to verify the effectiveness of the optimization.④ To make the vertical vibration performance of IWM-EV as good as the integrated-drive electric vehicle, bring in active suspension to the wheel of IWM-EV according to the principle of active wheel technology and establish multi-body dynamics model with ADAMS software to prove the effectiveness of the new structure. On this basis, put forward a Fuzzy-PID control strategy for the electromagnetic suspension. At last, carry on a joint-simulation with software ADAMS and MATLAB. The result proves the effectiveness of the combined control strategy.