Active suspension control by output feedback through extended high-gain observers

Abstract

The paper addresses extended high-gain observer (EHGO) design for a vehicle suspension system. The different way from previous reports is that a regional input-to-state stabilization (including exponential stabilization) controller is presented. To pursue this aim, first the original suspension dynamical equation is transformed into a normal form. And then, a feedback linearization controller is designed as the state feedback control, which makes the closed-loop system regionally input-to-state stable. Based on this, the output feedback control by using EHGO is proposed. The stability of the singular perturbation system composed by the state closed-loop system and the scaled error equation is demonstrated. Simulation examples are illustrated, which validate that provided small high-gain parameter the output feedback control will recover the performance of RISS under state feedback control and the responses of suspension performance behave better than those under the later.