LTR DESIGN OF PROPORTIONAL-INTEGRAL OBSERVERS

This paper applies the proportional-integral (PI) observer in connecti on with loop transfer recovery (LTR) design for continuous-time system s. We show that a PI observer makes it possible to obtain time recover y, i.e., exact recovery for t --> infinity, under mild conditions. Bas ed on an extension of the LQG/LTR method of proportional (P) observers , a systematic LTR design method is derived for the PI observer. Our r ecovery design method allows time recovery and frequency (normal) reco very to be done independently. Furthermore, we give explicit expressio ns for the recovery error when asymptotic recovery cannot be obtained. A design example demonstrates the advantages of time recovery in the non-minimum phase case.