A Co-Verification Interface Design for High-Assurance CPS

Cyber-Physical Systems (CPS) tightly integrate cyber and physical components and transcend traditional control systems and embedded system. Such systems are often mission-critical; therefore, they must be high-assurance. High-assurance CPS require co-verification which takes a comprehensive view of the whole system to verify the correctness of a cyber and physical components together. Lack of strict multiple semantic definition for interaction between the two domains has been considered as an obstacle to the CPS co-verification. A Cyber/Physical interface model for hierarchical a verification of CPS is proposed. First, we studied the interaction mechanism between computation and physical processes. We further classify the interaction mechanism into two levels: logic interaction level and physical interaction level. We define different types of interface model according to combinatorial relationships of the A/D (Analog to Digital) and D/A (Digital to Analog) conversion periodical instants. This interface model has formal semantics, and is efficient for simulation and formal verification. The experiment results show that our approach has major potential in verifying system level properties of complex CPS, therefore improving the high-assurance of CPS.