Implementation of PID Autotuning Procedure Based on Doublet-Pulse Method in PLC Controller

The paper describes the implementation of a PI controller autotuning procedure based on the doublet-pulse method. The doublet-pulse method is used as a tool to identify the control object. Its main advantage is its simplicity, requiring only two parameters to be declared, i.e., the amplitude and duration of the two step signals. We combined the Doublet-Pulse method with the Approximate M-constrained Integral Gain Optimisation tuning rules and implemented this combination as a stand-alone autotuning procedure in Siemens S7-1200 PLC controller. The procedure was tested for three types of simulated plant models. The simulated models were diverse in terms of dynamics, as we used lag-dominated, balanced, and delay-dominated models. We compared the doublet-pulse method with the classical identification method in the form of step response, i.e. method of moments. We conducted tests for three scenarios, i.e., a step change in the set point, set point trajectory tracking and load disturbances. To assess the control quality, we used integral index IAE. The described method is universal and can also be implemented in controllers from other manufacturers.

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Opracowanie rekordu ze środków MNiSW, umowa nr SONP/SP/546092/2022 w ramach programu "Społeczna odpowiedzialność nauki" - moduł: Popularyzacja nauki i promocja sportu (2024).