On Use of Adaptive Schedules in Semantic Modeling of Real- Time Control Algorithms

The paper presents a semantic model for time-driven real-time control algorithms based on adaptive schedule. In contrast to known models of semantics of programs and reactive systems based on the notion of state, use of adaptive schedules allows avoiding surplus detalization which leads to a `state explosion' problem. On the other hand, adaptive schedules correspond well to the nature of real-time control algorithms. The use of this model allows automated checking of the control algorithms' synchronization properties. The paper describes two case studies of application of a presented model for automation of design and verification of spacecraft's onboard flight control programs. The use of adaptive schedules semantics together with domain specific language, and automation toolset allow formal specification and verification of the important properties of realtime systems.