A framework for FMI-based co-simulation of human–machine interfaces

A framework for co-simulation of human–machine interfaces in Cyber-Physical Systems (CPS) is presented. The framework builds on formal (i.e. mathematical) methods. It aims to support the work of formal methods experts in charge of modelling and analysing safety-critical aspects of user interfaces in CPS. To carry out these modelling and analysis activities, formal methods experts usually need to engage with domain experts that may not fully understand the mathematical details of formal analysis results. The framework presented in this work mitigates this communication barrier by allowing formal methods experts to create interactive prototypes driven by formal models. The prototypes closely resemble the visual appearance of the system being developed. They can be used to discuss details of the formal analysis effort without showing any mathematical detail. An existing prototyping toolkit based on formal methods is used as baseline technology. Novel functionalities are developed for automatic generation of interactive prototypes supporting the Functional Mockup Interface (FMI), a de-facto standard technology for simulation of complex systems. Using the FMI interface, the prototypes can be integrated with simulations of other system components. The architecture of the framework is presented, along with a verification of core aspects of its functionalities. A case study based on a medical system is used to demonstrate the capabilities of the framework.