In this paper a generalized tuning methodology for proportional–integral–derivative (PID) controllers is proposed. The methodology is akin to the Ziegler–Nichols forced oscillation method, inheriting fully its practical appeal, but can be applied to much more general classes of plants. This generalization is achieved by employing a relay with adjustable phase (RAP) in a relay feedback experiment, and the tuning consists of formulas based on measurements obtained from this experiment. Experimental results in a liquid processing plant with of-the-shelf industrial equipments illustrate the performance of the methodology and the practical procedures involved in its application, which can be fully automated.
- Fractional-order systems
- Frequency domain controller design
- PID controllers
- Process control
- Relay with adjustable phase (RAP) experiment
- Ziegler–Nichols (ZN) methods