An Optimization Software Tool for Performance/Robustness Analysis and Tuning of PID Controllers

This paper presents an optimization and simulation software tool with a graphical user interface to analyze the trade-off between the performance and robustness of PID control systems. The process can be represented by a first- or second-order plus dead-time model and the controller is a PID-type controller with one or two degrees of freedom. From the information of the model, the PID is designed for optimal integrated absolute error (IAE) performance and also it is possible to tune the controller with three different levels of degraded IAE performance, in order to modify the robustness of the system. The tool allows to test different model/controller combinations and it is concluded that degrading the control system performance to increase its robustness has a higher impact over the controller gain than over other of its parameters. The software tool allows to study the relation between control system performance and robustness by undergraduate students of a control system course.