Control systems with rate and magnitude saturation for neutrally stable open loop systems

A systematic methodology for the design of control systems with multiple saturations in control magnitude and rate is introduced. A supervisor loop is introduced. When the references and/or disturbances are small enough not to cause saturations, the system operates linearly as designed. When the signals are large enough to cause saturations, the control law is modified in such a way as to preserve, to the extent possible, the behavior of the linear control design. It is shown that the operator error governor can be used to design control systems when the controls saturate in magnitude and rate. The main benefits of the methodology are that it leads to controllers with the following properties: the signals that the modified compensator produces never cause saturation; possible integrators or slow dynamics in the compensator never windup; the closed-loop system has inherent stability properties; and the online computation required to implement the control system is feasible. An example is used to illustrate the methodology and its benefits