Ajuste de controlador PID por método de autossintonia baseado em estimativa de robustez

Abstract

This work proposes a autotuning method of PID controllers, in order to guarantee robustness to the system, being implemented in Programmable Logic Controller (PLC) through relay experiments, with the possibility of being applied in PI-D controllers. The autotuning method proposed was developed through the adaptation of methods directed to existing PI controllers, with the objective of using few iterative structures, allowing the implementation in PLC, as well as improving the performance in the transient response of the system. Robustness is obtained by the maximum sensitivity of the system. Relay experiments provide frequency response points that allow calculation of parameters that modify the original terms of the controller in order to remove the points from the interior of the maximum sensitivity circle. Results of two PLC applications of different didactic systems allowed comparison with an existing PI controller tuning method and the demonstration of the effectiveness of the method.