Relay feedback test used for process identification and PID tuning controller by genetic algorithms

In this article, a proposal to solve two control problems from multiple point identification process frequency response of linear models, using a relay closed loop is presented. The identified points are used, in one case a PID controller tuning, and the other application deals with transfer function modeling problem. Both problems are stated as a nonlinear least squares unconstrained minimization problem. The optimization problem is solved with a simple genetic algorithm.