A test-driven approach for model-based development of powertrain functions

Vehicle functions for engine control units are modeled using a set of software units, so-called modules, specifying the discrete and continuous behavior of the corresponding function. As required by ISO26262, each module needs to be tested separately. Established techniques for model-based testing necessitate a requirements specification from which a test model can be derived. In practice, requirements are specified by natural language and on the level of whole vehicle functions instead of modules so that test models on module level can not be derived directly. Therefore, we propose a systematic model-based, test-driven approach to design a specification on the level of modules, which is directly testable. We demonstrate our approach on a Selective Catalytic Reduction system, a real world case study from automotive software engineering.