A formal model of IEC 61499-based industrial automation architecture supporting time-aware computations

Abstract

This paper proposes a formal model for industrial cyber-physical systems (CPS) with distributed control based on IEC 61499 standard and supporting time-aware computations for better adaptation to the ever changing environment conditions. Main features of the model include usage of timestamps, flattening, unified and independent behaviour of function block interfaces. This allows to make correct implementation of time-aware systems and significantly simplify the construction of models for verification and simulation, as well as ensure fairness of the model and determinism of the function block system execution at a resource level. The model formalism is based on a well-known abstract state machines (ASM) notion, which can be used as an intermediate formal representation to generate a variety of models for different purposes, e.g. formal verification, and executable code. This paper exemplifies this approach by the generation of models in the SMV language. The paper discusses the time-aware computation concept and its application in a few related case studies.