Delay-dependent criteria for robust dynamic stability control of articulated vehicles

In this paper, the dynamic stability analysis and control of an articulated heavy vehicle is investigated. First, lateral dynamics of an articulated heavy vehicle is described by a 3-DOF rigid body model. Then, it is considered as a linear system with steering input with delay. System states are the lateral and yaw motion of the tractor unit and the yaw motion of the semitrailer unit. Thus a less conservative stability criterion is developed for this system with time-varying delay. The key idea is constructing a new type of LKF containing a quadruple-integral term. Moreover, novel free-weighting matrices are introduced to increase the degree of freedom in the sufficient stability condition. The proposed delay-dependent stability measure is presented in the terms of linear matrix inequalities (LMIs). Numerical simulations are performed to show the performance of the proposed approach and demonstrate that the suggested scheme is remarkably less conservative compared to the available stability analysis approaches in the literature.