Automatic tuning of commercial PID controllers for single-loop and multiloop applications

Certain continuous-time self-tuning algorithms are shown to be capable of generating tuning parameters for commercial proportional-integral-derivative (PID) controllers. They are also shown to be capable of generating a feedforward signal that decouples the disturbance from the interaction from adjacent loops in a multivariable situation. The approach is verified using a standard Atari personal computer supervising Eurotherm 820 PID controllers. Two systems are used to test the method: a laboratory water tank system under level control and an industrial multizone plastics extruder under temperature control.<>