Design of a linear time-invariant control system based on a multiobjective optimization approach

Abstract

This paper explores the optimal design problem of a linear time-invariant control system composed of three different types of linear parallel actuators. The actuators' time constants have been defined to achieve a conflicting behavior among the transient response provided by them. Thus, a novel solution has been proposed to find the best selection of actuators' gains to improve the performance parameters. Such methodology is based on a discrete multiobjective optimization technique. The transfer functions, as well as the transient response, have been derived and evaluated throughout this work. In addition, the stability conditions have been analyzed for a range of closed-loop poles and zeros. The discrete multiobjective optimization problem is formulated with a couple of objective functions: overshoot and settling time of the closed-loop response. A decision-making method has been used to find the best compromise solution from a group of candidate solutions. The results have indicated that a better performance can be achieved with a systematic multiobjective optimization methodology.