PID control performance assessment in various scenarios using L-moment ratio diagrams

Implementation of any control system requires the method and measures that allow assessment whether the applied system works satisfactory. Practitioners use various key performance indicators (KPIs) that allow them to indicate poor or good control. The basic ones: overshoot and settling time are almost ideal, if not for one limitation -- in practical solutions there is a serious difficulty in determining them. Therefore there is an ongoing and yet unsolved need to evaluate their reliable counterparts. Researchers and practitioners use various statistical factors, integral indexes or benchmarking measures. This research investigates two areas. Novel approach using different variants of symmetrical moment ratio diagrams (MRDs) is proposed and tested in various simulated scenarios. Moreover, an impact of the control goal: setpoint tracking or disturbance rejection for various signal profiles is evaluated assessing index feasibility areas. The paper is concluded with the methodology validation conducted for real industrial loop data.