Vehicle lateral motion chaos analysis based on the Lyapunov exponent method and sliding mode variable structure control

Abstract

In this paper, a 3-DOF nonlinear model including the yaw, lateral and rolls motion was constructed, and then the chaos numerical simulation analysis was performed based on the Lyapunov exponent method. Through the Lyapunov exponent and bifurcation diagrams, the vehicle motion was relatively complex, containing double-periodic, quasi-periodic and chaotic motions, which was harmful for the stability of the lateral motion of vehicles. In order to realize the control of chaos during vehicle lateral motion, the SMVSC controller was designed by using the sliding mode variable structure control (SMVSC) method. To decrease the chattering of the SMVSC system and further improve the stability of vehicle lateral motion under extreme operation conditions, the adaptive power reaching law was realized by using the fuzzy control method. Finally, the SMVSC system based on the designed adaptive reaching law was simulated in the Matlab/simulink, and the simulation results of uncontrol, SMVSC control and SMVSC control based on the adaptive reaching law were compared. It can be found that the SMVSC control based on the adaptive reaching law can present better performance than that of others by effectively suppressing the chaos during vehicle lateral motion and significantly improving the stability of vehicle lateral motions under extreme operation conditions. Therefore, it is proved that the control strategy is effective.