Quasi-optimal Character of Metaheuristic based Algorithms used in Closed Loop Evaluation through simulation series

A stand-alone metaheuristic based algorithm can solve a specific optimal control problem, but the result is an offline "optimal" solution, which is a sequence of values assigned to the control inputs over the control horizon. Because this solution can be exploited only within an open-loop control structure, the algorithm has to be adapted in order to be used inside a closed-loop control structure as controller. But this adaptation and also the dynamics of the real process involve a degradation of the optimal character of the control structure, namely a decreasing of the performance index. This paper proposes a method for analyzing the behavior of the closed-loop based on three simulation models. Using this tool, one can state whether the solution implemented by the real-time control system has a proper quasi-optimal character.