A Behavior Specification and Simulation Methodology for Embedded Real-Time Software

Safety-critical real-time systems must be carefully designed to guarantee both functional and temporal correctness. State-of-the-art approaches to achieve this are often based on formal notations capturing both the desired functionality and relevant timing properties. This work is concerned with the design of embedded software systems for emerging fields such as the Urban Air Mobility (UAM) sector. In this context, it deals with scenarios that benefit from a less formal programming model, but for which guarantees on functional and timing behavior must still be provided. We propose a concept to specify and simulate the behavior of embedded real-time software in a deterministic manner. It combines the Logical Execution Time (LET) paradigm with a flexible, code-based approach for behavior specification and performs discrete-event (DE) simulations to determine how exactly the designed system responds to given stimuli. We describe this concept, present a reference implementation using Ptolemy II as simulation backend, and discuss its application to a pilot assistance system from the UAM sector.