OBSERVER DESIGN FOR LOOP TRANSFER RECOVERY

A design technique of loop transfer recovery (LTR) is introduced to design a robust full-order observer that recovers the full-state feedback loop properties for uniformly completely controllable (UCC) and uniformly completely observable (UCO) linear time-varying (LTV) systems. Asymptotic loop transfer recovery is achieved by selecting the observer gains based on the observability Gramian of closed loop system. We study the loop recovery problem at the input of the plant when the loop is broken•t the input When the loop is broken at the output, similar results can be developed for the recovery problem at the output of the plant. For linear time-invariant (LTI) systems the observer gain is computed via solving a simpler algebraic equation compared with the standard.. linear quadratic Gaussian/loop transfer recovery (LQG/LTR). For linear time-varying (LTV) systems the stability of the closed loop system is guaranteed during the recovery process without any additional constrain. Finally, two examples are given to illustrate the effectiveness' of the proposed approach.