Estimation of parameter variation based on the disturbance observer. Application to the estimation of the inner pressure of tires

Abstract

This paper deals with an estimation method of parameter variations of dynamic systems based on the disturbance observer. In this method, the disturbance observer is designed to estimate the parameter variations as disturbances. A necessary and sufficient design condition for the existence of disturbance observers is shown from the view point of the observability of extended systems. This condition is used to determine the states to be measured by sensors for corresponding parameter variations. The simple correlation method extracts the parameter variations from the estimated disturbances which include external disturbances and noise. The proposed method is applied to the estimation of the inner pressure, i. e. the stiffness, variations of tires in the active suspension system. Several numerical and experimental results are shown to confirm the effectiveness of the method. © 1994, The Institute of Electrical Engineers of Japan. All rights reserved.