Modeling and verifying active structural control systems

This paper presents the results of a case study involving the use of a formal graphical notation, Modechart, and an automatic verification tool, the Concurrency Workbench, in the analysis of the design of a fault-tolerant active structural control system. Such control systems must satisfy strict requirements on their timing behavior; we show how to use various equivalence-based features supported by the Workbench to examine the timing behavior of different design alternatives, one of which has in excess of 1019 states. The central insight arising from the study involves the importance of compositionality for reasoning about large and complex systems; in particular, the success of the case study depends integrally on our notationʹs and toolʹs support of componentwise minimization.