Construction of an active suspension system of a quarter car model using the concepts of sliding mode control

This paper is concerned with the construction of an active suspension syste m for a quarter car model using the concept of sliding mode control. The ac tive control is derived by the equivalent control and switching function wh ere the sliding surface is obtained by using Linear quadratic control (LQ c ontrol) theory. The active control is generated with non-negligible time la g by using a pneumatic actuator, and the road profile is estimated by using the minimum order observer based on a linear system transformed from the e xact non-linear system. The experimental result indicates that the proposed active suspension system is more effective in the vibration isolation of t he car body than the linear active suspension system based on LQ control th eory and the passive suspension system. (C) 2001 Academic Press.