Controller Design for Time Domain Specifications

The Coefficient Diagram Method (CDM) is a parametric approach to design a controller based on coefficient shaping. It involves two steps; first, characterization of the desired time response in terms of the two specific parameters denoted by (αi, τ), in this paper, that are functions of a characteristic polynomial. Once such a target characteristic polynomial is obtained, the controller parameters are determined accordingly. During the process of the design, both stability and performance of the closed loop system can be considered together. This paper first summarizes the recent results on basic properties of the parameter set (αi, τ) and shows a scheme to construct a target characteristic polynomial that meets a desired transient response characteristic. Finally, we show how to achieve a fixed order controller.