Abstract
This paper describes the development of a continuous damping control system for semi-active suspension which is based on nonlinear H##oo## control theory instead of conventional linear control theory. A two degree of freedom system is used as the plant for the vehicle suspension model. Since the plant is bilinear, it's not easy to design the controller. We design the controller for the nonlinear system based on the Hamilton-Jacobi inequality by solving a linear Riccati equation. Frequency weight function is properly designed in order to reduce sprung mass resonance, rugged vibration, and unsprung mass resonance, respectively, in the proper frequency band. We were able to verify by simulation that nonlinear H infinity control theory made it possible to control vehicle vibration optimally and smoothly.