Non-linear dynamics and control of an automotive suspension system based on local and global bifurcation analysis

Abstract

This paper details the non-linear dynamic behaviours and control of a non-linear semi-active suspension system using a quarter-car model under kinematic excitation by a road surface profile. The results of local and global bifurcation analysis indicate that the hysteretic non-linear characteristics of damping force cause the suspension system to exhibit codimension-two bifurcation, resulting in homoclinic orbits and a pitchfork bifurcation. The complex dynamic behaviour of automotive suspension systems was examined using a bifurcation diagram, phase portraits, a Poincare map, and frequency spectra. We also used Lyapunov exponent to identify the occurrence of chaotic motion and verify our analysis. Finally, a dither signal control was used to convert chaotic behaviours into periodic motion. Simulation results verify the effectiveness of the proposed control method.