Abstract： To improve the vehicle pitch characteristics, the index of vehicle pitch motion and the suspension control were investigated. Taking a certain model of SUV as an example, to solve the problem of existing pitch characteristics without suitable evaluation index, the concept of extended zero moment point was introduced into the vehicle pitch evaluation system with considering the influence of road slope on pitch characteristics, and the vehicle pitch model was adopted. The derivation of the position of zero moment point was extended to obtain the pitch evaluation index of XEZMP, which was used to evaluate the effect of pitch control. A complete vehicle dynamics model was established in Adams/Car, and an active suspension PID controller was designed with XEZMP as control target. The joint simulation was used to verify the control effect. The results show that compared with passive suspension, the active suspension significantly suppresses the changes in vehicle pitch angle, vehicle pitch angle speed and XEZMP, which improves the vehicle pitch characteristics. The pitch evaluation index of XEZMP can reasonably evaluate vehicle pitch characteristics.
