Time‐ and Behaviour‐Preserving Execution of Determinate Supervisory Control

ABSTRACT Behaviours and activities are natural concepts (found, e.g., in UML and SysML) for model‐driven design of cyber‐physical systems (CPS). These concepts are formalised in the activity framework , a model‐based framework incorporating a model of activities with determinate timing and behaviour, and a strong mathematical foundation based on max‐plus algebra that allows efficient timing analysis and optimisation. It provides a layered view of the system's actions and events, activities built from them, and sequences of activities that capture the overall behaviour of the system. Implementations of supervisory control for CPS to govern the system behaviour are often made by hand. Preserving the specified behaviour and the model‐predicted timing in an implementation is challenging, due to the need to simultaneously handle action timing, synchronisation, concurrency, pipelining and plant feedback . We introduce an execution architecture and engine to automatically synthesise an implementation of a supervisory controller directly from a model specification. The execution engine is guaranteed to execute a specification in a time‐ and behaviour‐preserving fashion, even in the presence of action timing variations and including event feedback in a physical execution. We prove that the architecture and engine preserve the specified ordering of actions and events of the model as well as the timing thereof, up to a known bound. We validate our approach on a prototype production system.