This article studies the supervisory control problem of discrete event systems (DES) with state-dependent controllability. The new problem is given with the background of operating systems where the processes and the interrupt service routines (ISR) are supervised and coordinated. The new model is novel because the controllability of an event is changeable in the lifetime of system evolution, and dependent on the system state. Two fundamental problems are concerned with the new model: supervisor existence problem and supervisor synthesis problem. We derive a necessary and sufficient condition for the existence of the supervisor, and introduce an algorithm to synthesise the supremal supervisor in a given specification. With the background of process and ISR management in operating systems, some examples are given to show how the new model can be applied to practical computing.
- Discrete event systems
- State-dependent controllability
- Supervisory control