Electronic Notes in Theoretical Computer Science

AbstractEmbeddedsystemsareofgrowingimportanceinindustry. Forexample,inatoday'svehicleahugenumberofembeddedandcommunicating systems can be found. Exhaustive testing of such systems is a requirement, because changes after deliveryand use are expensive and sometimes even impossible. In this paper we propose the use of qualitative models, which are anabstraction of quantitative physical models, for test case generation and test execution. In particular, we show how Simulinkmodels from which control programs are automatically extracted can be tested with respect to qualitative models. SinceSimulink models are heavily used in industry, the approach is of practical interest.Keywords: conformance testing, hybrid systems, qualitative reasoning, qrioconf, Garp3 1 Introduction In industry and especially in the automotive industry Simulink is often used to implementcontrol programs for various purposes. One reason is that those models can be directlyconverted into C code, which runs on the vehicle's electronic control units (ECUs). As aconsequence Simulink models have to be tested thoroughly. This holds in particular forsafety critical systems. In order to meet the safety and quality criteria of such modelsautomated test case generation and more specically model-based testing is of specicinterest but has hardly been explored. In order to ll this gap we present an approach thatmakes use of qualitative models for model-based test cases generation.Qualitative models represent basically cause-effect relationships and constraints onmodel variables. They can be seen as an abstraction of the usually implemented quan-titative differential equation models when using Simulink or other modeling languages.Hence, Simulink models are a renement of qualitative models. This is in contrast to theuse of other means for representing models in this domain like hybrid automata, whichshares basically the same abstraction level with Simulink models.Inordertoallowforusingqualitativemodelsformodel-basedtestingwehavetospecifythe equality relation between the specication and the implementation. For this purpose