Abstract:

In this paper, a new kind of real time discrete event system model is proposed based on the concept of state sojourn times. A definition of real time control-invariance is given for a certain predicate. It is shown that for this class of system, there is a state feedback controller such that the given predicate remains true at the state trajectories of the closed loop system if and only if the given predicate is real time control-invariant. It is also shown that for a given predicate, there is a unique supreme real time control-invariant subpredicate. A procedure is presented for its computation. Finally, an example is given to illustrate the results.

Key words: discrete event systems, state feedback, real time control, control-invariance