Loop-gain optimization of unstable-non-minimum phase feedback systems

摘要

The paper presents a design method for optimizing the loop-gain of unstable-non-minimum phase feedback systems. Because obvious gain-bandwidth limitations exist in such systems, the proposed best loop gain optimization goal is maximization of the stability gain and phase margins, which are inherently low in such feedback systems. The design procedure is based on coprime factorization of the plant and controller, and the Bezout identity. An optimization process varies iteratively the observer-based controller parameters until maximization of the gain and phase margins is achieved. The same design technique also allows one to solve the mixed sensitivity H infinity standard control problem for linear time invariant feedback systems. [References: 24]