Nonlinear fault diagnosis on vehicle system in the spring broken down

This paper analyses the stability of the dry friction vehicle system by using nonlinear map theory supposing that fault has happened to the spring. Numerical computation results show that the motion of the vehicle is in a stable periodic behaviour when the running speed is suitable and the spring is without fault. However, dynamic bifurcation and local chaos occurs when the spring part is broken down and the frequency of the excitation is changed. This causes instability of the vehicle system, and the information can be used for the fault diagnosis of the vehicle system. In addition, the dynamic behaviour of the system with damping coefficient changing has been considered. The computation result shows that changing of the damping coefficient has little effect on the stability of the vehicle system.