A PVS-Simulink Integrated Environment for Model-Based Analysis of Cyber-Physical Systems

TLDR

This paper presents a methodology and tool for formal modeling and analysis of software components in cyber‑physical systems, aiming to facilitate the integration of formal verification technologies into their development process. The approach enables developers to integrate logic‑based specifications of software components with Simulink models of continuous processes, generate these specifications from automata‑based formalism, formally verify them with PVS, and co‑simulate a pacemaker model with a heart model to validate design requirements. The integrated simulation validates discrete component characteristics early, and formal verification with PVS demonstrates safety compliance for the pacemaker model.

Abstract

This paper presents a methodology, with supporting tool, for formal modeling and analysis of software components in cyber-physical systems. Using our approach, developers can integrate a simulation of logic-based specifications of software components and Simulink models of continuous processes. The integrated simulation is useful to validate the characteristics of discrete system components early in the development process. The same logic-based specifications can also be formally verified using the Prototype Verification System (PVS), to gain additional confidence that the software design complies with specific safety requirements. Modeling patterns are defined for generating the logic-based specifications from the more familiar automata-based formalism. The ultimate aim of this work is to facilitate the introduction of formal verification technologies in the software development process of cyber-physical systems, which typically requires the integrated use of different formalisms and tools. A case study from the medical domain is used to illustrate the approach. A PVS model of a pacemaker is interfaced with a Simulink model of the human heart. The overall cyber-physical system is co-simulated to validate design requirements through exploration of relevant test scenarios. Formal verification with the PVS theorem prover is demonstrated for the pacemaker model for specific safety aspects of the pacemaker design.