Robust Linear PID Control of a Pressure Reducing Valve

This work presents the design of controls for a pressure-reducing valve considering stability and robustness issues and preserving the classical linear proportional-integral-derivative (PID) structure included in, nowadays, industrial controllers. Due to only the outlet pressure being measured for control purposes, other variables, flow and inlet pressure, are included in the uncertainty of the system. The theory of Lyapunov allows for validating the linear PID proposal even considering the nonlinear relation between inlet pressure and flow with the behavior of pressure-reducing valves. A brief robustness analysis demonstrates how the proposal can cope with the uncertainties of the system. Finally, experimental and simulated results indicate the good performance of the control. (C) 2022 American Society of Civil Engineers.