The Key Role of Virtual Prototypes for the Functional Safety of Software-Defined Vehicles

In modern vehicle development, proof of functional safety represents a crucial aspect since the software content in vehicles and the significance of automated driving functions are continuously increasing. While humans can act as a fallback level for conventional systems, algorithms take over this role for automated driving functions. They depend on the complete and correct recognition of the vehicle’s environment at all times and on the error-free communication of the vehicle’s components, such as sensors, actuators and ECUs, with each other. To ensure functional safety in all traffic situations, the focus on the full vehicle needs to be strengthened in development. Integration and system tests enable investigations of the interaction between all components. Due to the variety of possible traffic situations, an extremely large number of tests is required to achieve maximum test coverage for proof of safety. This is the only way to ensure accurate handling of any situation. For every stage of the development process, there are suitable test methods that offer support to achieve the required test coverage with simulation: software-in-the-loop (SIL), hardware-in-the-loop (HIL) and vehicle-in-the-loop (VIL). The targeted test strategy resembles a funnel. The early development stage starts with high levels of virtualization, automation, parallelization and, derived from this, many possible tests. Over the course of the development process, the scope of every aspect mentioned before decreases continuously while the tests remain entirely reproducible at any time. An open integration and test platform (e.g. CarMaker) offers the possibility to implement tests automatically and safely as well as in an unlimited number of critical scenarios, and thus ensures functional safety. Combined with agile software development, virtual vehicle development lays an ideal foundation for coping with said requirements for functional safety and for enabling assurance of the necessary quality.