A Set-Based Approach to Derive Contracts for Dynamic Behavior in Interconnected Systems

Cyber-Physical Systems (CPSs) are characterized by the interplay between numerous hardware and software components. To design large-scale CPSs, the so-called contract-based design (CBD) methodology has gained in importance over the recent years. The advantage of this approach is that desired behavior of the overall system can be ensured by a suitable composition of sub-contracts for individual system components. Besides a specification of the nominal system behavior, contracts can also be used to detect faulty system behavior, when they are embedded into monitors. It is possible to further account for uncertainty in the design methodology, if set-based and/or stochastic extensions are included into the CBD. In this paper, we propose a novel, decentralized systematic set-based derivation procedure for contracts, which is especially applicable when stability of the interconnected CPS can be verified with the help of the system property of passivity or the small-gain theorem.