Windup in Control Owing to Sensor Saturation

This brief presents methods for anti-windup control in the presence of saturating sensors, arbitrary external reference inputs, and constant or step-like disturbance inputs. It also offers techniques to assure windup prevention when both the input and the output signals are limited and this for systems with one input (SISO) and multiple inputs (MIMO). The emphasis in both is on real-world practicality rather than rigorously proven stability.

Two novel solutions for anti-windup control are explored. The first approach, for SISO systems only, follows the classic design paradigm of anti-windup control: design an arbitrary linear compensator and add appropriate measures for their prevention if saturation causes stability problems. This uses a saturation indicator detecting the presence, but not the extent of saturation. The second methodology uses a compensator design that assures the desired rejection of persistent disturbances without jeopardizing closed-loop stability, and can be applied to SISO and MIMO systems alike.