Simulating Electrical Devices with Complex Behaviour

Automotive electrical and electronic systems have become very sophisticated in a relatively short time. This complexity has both led to the increased need for design analysis tools and the need for these tools to deal with more complex components. Qualitative simulation of electrical circuits has proven to be invaluable in the development of several design analysis techniques and the ability to build qualitative models for complex components has become essential to allow effective use of these tools. We have addressed the need to model complex electrical components by developing abstract representations for the behaviour to supplement the qualitative electrical simulation. This development has been carried out in two stages. In the first stage we provide the ability to include dependencies between the electrical activity in one part of a component and the (qualitative) resistance values in another. This approach is known as QCAT (Qualitative Circuit Analysis Tool), an early version of which is documented in [11] and has been implemented in the industrially used FMEA tool, Autosteve. The second stage (QCAT-SB) uses state based descriptions to allow more complex behaviour descriptions including temporal specifications. QCAT-SB will be included in the next release of Autosteve.