EXACT OBSERVER-BASED STRUCTURES FOR ARBITRARY FULL-ORDER COMPENSATORS

摘要

In this paper, some new techniques for determining the observer-based or LQG form of any full-order compensator, that is, a compensator whose order is the same as the plant's order, are discussed. The practical appeal of such techniques is thatthey allow for a simplified implementation and reduced memory storage of general controllers and offer additional flexibility for handling gain-scheduling and input saturation constraints. The derived observer-based controllers are input-output equivalent to the original controller but with an explicit separated estimation/control structure and an extra Youla parameter. Necessary conditions to apply this general controller equivalence principle are derived.The interest and practicality of such techniques are then investigated with regards to the LQG implementation of H{sub}∞ and μ controllers, classes of controllers that does not generally enjoy ease of implementation. In particular, these aspects haverevealed to be of crucial importance for the applicability of the H{sub}∞ technique to attitude control of launchers.