Finite-dimensional control of a flexible space structure: A new view based on input-output space

Abstract

How to design a simple, finite-dimensional controller for complex, infinite-dimensional Flexible Space Structures (FSSs) with uncertain physical parameters is the main topic of this paper. The research shows that a simple controller that makes the controlled FSS system of high stable degree can be obtained by using only the input-output property instead of the poles-zeros property of the FSS system, which is a new result in the control of uncertain FSS systems. The main idea can be summarized as: (1) it is difficult, even impossible, to obtain convergent poles and zeros estimation for an uncertain FSS system, which is different from that in a finite-dimensional system; (2) there is an inherent relation between the input-output property and the poles-zeros property for the FSS system, which means that modelling and controlling, based on the input-output property, may guarantee the high authority control of the FSS system; (3) in the H sense and based on input-output space to make the model error as small as possible and the controller tolerate a model error as large as possible, will result in a very low dimensional controller.