International Journal of Control, Vol.70, No.2, 271-288, 1998
Safe implementations of supervisory commands
Two different types of control strategy used to safely implement supervisory commands of hybrid dynamical systems are compared. Both approaches considered switch between members of a family of control agents to ensure that constraints on the plant state are not violated at any time. The first approach is motivated by a hybrid system architecture outlined by Kohn and Nerode (1993) and uses a Fliess functional series of the plant's output to form a system of linear inequalities characterizing safe control inputs. Control signals are determined by solving a sequence of linear programs. The second approach is a model reference control approach to hybrid systems introduced by Lemmon and Bett (1996) and uses a known safe dynamical reference model to characterize the desired plant behaviour. The controller is determined by representing the resulting error dynamics as a linear parameter varying system and applying linear robust control techniques to enforce a bounded amplitude performance level. The fundamental results underlying each of the methods are derived; the approaches are compared with regard to their complexity, performance and sensitivity to modelling uncertainty. A numerical example is included for illustration.
Keywords:GAIN SCHEDULED CONTROL;PLANTS