In: 29th Annual International Computer Software and Applications Conference (COMPSAC'05), Volume 2, pages 97-100. 2005. http://doi.ieeecomputersociety.org/10.1109/COMPSAC.2005.148.
Abstract: We define supervisory controllers for enforcing deadlines on transition firings in time Petri nets. Given a target net transition td, and a deadline lambda, we generate a controller that under broad assumptions forces td to fire every lambda time units. Our supervisory controller is based on the notion of transition latency. The latency of a net transition is an upper bound on the time between the firing of that transition and the firing of td. A transition is not allowed to fire when its latency is greater than the amount time left until td must fire.
Our real-time supervisory controllers consist of two subnets, which are added to the controlled net in order to enforce deadline lambda on the firing of td. First, the clock subnet dynamically tracks the amount of time left until the expiration of lambda. As the deadline approaches, this subnet also indicates transitions that must be disabled because their latency has become greater than the time until the expiration of the deadline. When this happens, a supervisor subnet actually disables these transitions. These transitions are enabled again only after td has fired.
Back to the Petri Nets Bibliography