Deadtime Compensation and Zero Frequency Decoupling of a Thermal Hydraulic Process

Abstract

This brief details the design and experimental implementation of a practical multivariable controller applied to a thermal hydraulic process. Features of the design include a first-order plus deadtime process model, zero frequency decoupling, and multivariable deadtime compensation. The deadtime compensator allowed higher loop gains and consequently improved overall performance. Practical first order prediction based on an estimated delay and process time constant achieved the deadtime compensation. The high gain controller effectively handled both setpoint changes and disturbance rejection. An intelligent choice of estimation schemes yielded a simple but accurate model.