Prioritization schemes for reference and command governors

Reference and command governors are predictive add-on schemes that are applied to closed-loop systems and guarantee constraint enforcement while tracking desired reference inputs. This paper introduces two methods for using these predictive methods in the presence of prioritized constraints. The first method handles the case of “soft” constraints by using a slack variable to relax the constraints. The second method prioritizes the reference inputs, enforcing the constraints by modifying the lower priority reference inputs first. Two examples are reported consisting of a constrained spring-mass-damper system and an F-16 aircraft with actuator constraints.