Two-level Control of Processes with Dead Time and Input Constraints

This paper proposes a new idea, shaping the control signal, and generalizes the time-delay-filter-based deadbeat control for processes with dead time to two-level control so that the controller saturation is avoided. The controller mimics experienced manual operations to provide a two-level control signal. At first, the controller outputs a value close to the maximal value and then the controller outputs a smaller value to maintain the steady-state output at the set point. The system output reaches the steady state in finite time, which is explicitly determined by the upper bound of the control output and is independent of the controller and (almost) of the sampling period. The disturbance response can be freely tuned according to the desired phase or gain margin. Three examples are given to show the effectiveness of the proposed controller.