Schemes Research and Application of Close-to-Wheel Drive System Based on Slider-Crank Mechanism

Normal in-wheel drive system with large unsprung mass has negative effects on the ride comfort and wheel ground adhesion. Therefore, three new kinds of close- to-wheel drive concepts were proposed: the motor suspended on car frame, the motor suspended on knuckle and two-stage suspension. Dynamic differential equation with the three concepts were deduced and their three degree-of-freedom(DOF) vibration models of 1/4 suspension were established in MATLAB software respectively. In order to analyze the three concepts' effects of ride comfort and handling stability compared with in-wheel drive system, the multi-objective genetic algorithms was applied to optimize the added stiffness and damping parameters of different concepts based on two objectives of Root-Mean-Square of body acceleration and wheel dynamic load.