Design of PI controller: A multiobjective optimization approach

This paper addresses the design of a PI controller as a multiobjective problem. For a given plant the design of a PI controller satisfies a given set of specifications and for acceptable design the parameters of the PI controller are to be adjusted so that whole closed loop system satisfies the specifications. A multiobjective optimization approach is implemented here to adjust the parameters of the PI controller and since the design presented here is multiobjective, hence for acceptable design some tradeoff is made among the specifications given. Since the robustness and the performance is not guaranteed both at the same time, due to this reason only some tradeoff is necessary and this paper addresses the contradiction between robustness and performance of PI controller by framing it into a multiobjective optimization problem. The simulation of multiobjective problem generates the Pareto front from which on can make the compromise between performance and robustness. The simulation results derived from the above said approach is applicable for large number of systems.