Robust H2 Control of Active Suspension-Improvement of Ride Comfort and Driving Stability

This paper suggests a method of robust control for an active suspension to improve both of the ride comfort and the driving stability using half car model. The ride comfort is evaluated by the vertical acceleration and the pitch acceleration of the human body. The driving stability is evaluated by the vertical force of front and rear wheels. The purpose of this paper is to improve the ride comfort and the driving stability by using state feedback. On the other hand, the robust stability is also important factor to evaluate the performance of the car. In this study, the front and rear weights of car body are considered as uncertain parameters depending on the passengers and the loads. Their weights influence on the pitch motion of the car body. The robust H-2 controller is designed to guarantee the robust stability for the system with uncertain parameters with polytopic representation. These problems are solved by a finite set of Linear Matrix Inequality (LMI). The effectiveness of the proposed method is illustrated by simulations and experiments.