Yoshikazu Motozono

Nonlinear H∞ control for semi-active suspension

Abstract This paper describes the development of a damping control system for semi-active suspension which is based on nonlinear H ∞ control theory instead of conventional linear control theory. A two degrees of freedom system is used as the structure for the vehicle suspension model. Since the structure is bilinear, its not easy to design the controller. We designed the controller based on the Hamilton-Jacobi inequality by solving a linear Riccati equation. We were able to verify by simulation that nonlinear H ∞ control theory made it possible to control vehicle vibration optimally and smoothly.

A Feedback/Feedforward Accommodation of Load Change and its Application to Control of Reformer for Fuel Cell Vehicle

Abstract Output regulation for nonlinear plants with large load variation is considered assuming that a nonlinear model of the plant for simulation is available. A linear model of the plant for a fixed load is obtained via 4SID method which naturally leads to a feedback/feedforward control architecture. The control configuration is applied to control of reformer for fuel cell vehicle, where H∞ control is applied for feedback. It is shown both theoretically and experimentary that the overall feedback/feedforward configuration achieves a high performance of regulation under heavy load change.