Internal model-based control for integrating processes.

Internal model-based control (IMC) has been shown to possess many advantages over PID control, particularly in the presence of significant process deadtime. Implementation of IMC is simplified in a large class of industrial applications where the process dynamics can be adequately characterized by a simple first-order model requiring only estimates of process gain, lag time constant, and deadtime for implementing the controller design. Tuning of the controller is easily and intuitively done by adjusting the filter time constant; decreasing the time constant speeds up the closed-loop response, and increasing it yields generally a slower but more stable response.