Vibration suppression of four degree-of-freedom nonlinear vehicle suspension model excited by the consecutive speed humps

It is well known that chaos phenomenon is harmful for a nonlinear mechanical vibration system. For a running vehicle, chaotic vibrations may lead to early damage to road and the component of vehicle or even bring physical injury to crew member. In this paper, we first studied the possibility of chaotic vibration of the four degree-of-freedom half vehicle model under consecutive speed control humps on the highway. Then, a direct variable feedback control is proposed to eliminate the influence of chaos on vehicle nonlinear vibrations and how to select proper control parameters is discussed.