Abstract:In order to research the influence of bogie's hunting motion on car body shaking, a multi-rigid vehicle system model is established at first, and the local deterioration of lateral ride quality is reproduced. Secondly, the concept of modal coupling degree is defined based on the Euclidean Closeness which belongs to fuzzy mathematics theory. In order to reduce the coupling degree of the system, the suspension parameters of the vehicle are optimized. The results show that transverse coupling vibration occurs when the frequency of bogie hunting and the natural frequency of car body approach which can decreases the ride quality. The severe transverse coupling vibration is, the greater the degree of coupling is. The coupling degree of system can be reduced if the vehicle suspension parameters are appropriate. So that the transverse coupling vibration can be weakened and the local deterioration of the lateral ride quality will be eliminated.