On finding polynomial controllers with reduced pole sensitivity using state space methods

The problem of inaccuracies or variations in the parameters of the open-loop model on the poles of the closed-loop system is considered. It is assumed that the system is in input-output form and that the controller design is via pole-placement. The input-output description of the plant does not easily facilitate a direct investigation of the poles of the system. However, the state space description does. This paper presents a different approach to the design of pole-placement controllers for systems in input-output form by transforming to a state space system, performing an output feedback design and transforming the controller back to polynomial form