부산대학교 도서관

Cyber physical systems (CPSs) are characterized by behaviors emergent from the interactions of software systems with physical systems. Many complex CPSs utilize “independent monitoring” of the system behavior for any undesirable effects so that appropriate mitigation actions can potentially be taken. Typical independent monitoring systems for CPSs focus only on the violation of specified constraints that are detected “after-the-fact,” and any preemptive attempts to prevent the violation are handled by the core software systems. In this paper, we propose an independent health monitoring mechanism as a human-recognizable measure of trustworthiness of the system. Specifically, this mechanism not only detects actual violations of constraints but also calculates the possibility to violate the constraints. The proposed health monitor has two components: 1) health measurement functions that are specific and tailored to each component of a CPS and 2) a probabilistic health-state determination that is generic and directly derived from Bayesian estimation methods. The implementation and performance of the proposed monitoring mechanism were demonstrated with an autonomous vehicle self-navigating to a free parking space in MATLAB/Simulink simulations, which showed that the mechanism was able to promptly and accurately estimate the health state of the monitored system and help prevent accidents/catastrophes.