To ensure operational safety of complex cyber-physical systems such as automobiles, aircraft, and medical devices, new models, analyses, platforms, and development techniques are needed that can predict, possible interactions between features, detect them in the features' concrete implementations, and either eliminate or mitigate such interactions through precise modeling and enforcement of mixed-criticality cyber-physical system semantics. This project is taking a novel approach to reasoning about and managing feature interactions in cyber-physical systems, which encompasses interactions within software, interactions through the physical dynamics of the system, and interactions via shared computational resources. The proposed approach consists of three tightly coupled research thrusts: (1) a novel way of modeling features as automata equipped with both physical dynamics of the feature environment, and an assigned criticality level in each state of an automaton, (2) new automata-theoretic and control-theoretic analysis techniques, enabled by the modeling approach, and (3) new algorithms for adaptive sharing of computational resources between individual features that are guaranteed to satisfy the assumptions made during analysis, realized within a novel mixed-criticality cyber-physical platform architecture. The modeling approach will introduce a new model for mixed-criticality cyber-physical components and will support modern development standards, such as AUTOSAR in the automotive industry, for assigning criticality levels to features. Component interfaces in this model will capture control modes and the associated physical dynamics, operating modes and the associated resource requirements and criticality level, as well as relationships between control modes and operating modes. Analysis of features expressed in the proposed model will include detection of interactions and exploration of their effect on safety properties of the composite system. The broader impacts of the proposed work are twofold. One impact lies in the pervasive use of cyber-physical systems in our society. If the developed results are adopted in industry, it may help to promote improved safety of such systems. Results of the proposed research will be used in courses offered at both University of Pennsylvania and Washington University at the graduate and undergraduate levels. The project will also provide students with opportunities to get involved in cutting edge research within their fields of study
