In this paper we combine classical fault tree analysis and formal specifications to analyze the dependability of a transportation scenario. The example is a radio-based level crossing control system.

Well understood methods exist for developing programs from given specifications. A formal method identifies proof obligations at each development step: if all such proof obligations are discharged, a precisely defined class of errors can be excluded from the final program. For a class of “closed” systems such methods offer a gold standard against which less formal approaches can be measured. Fo...

This paper presents a novel approach for applying behaviour-based concepts at a high, deliberative layer of a robot control system. Complex tasks which a robot shall fulfil are typically specified using finite-state machines. It is shown here that behaviour-based systems can be used to implement such machines. This allows for realising complex tasks and at the same time benefit from the advanta...

Discussion of a radiation dose calculation example demonstrates various expressive limitations of the reenement calculus, particularly for systems with continuous variables. A liberalization of reenement, called retrenchment, is proposed, which will support an analogous formal development calculus. Useful concrete system behaviour can be speciied outside the domain of pure reenement, in particu...

Abstraction is a natural way to hierarchically decompse the analysis and design of hybrid systems. Given a hybrid control system and some desired properties, one extracts and abstracted system while preserving the properties of interest. Abstractions of purely discrete systems is a mature area, whereas abstractions of continuous systems is a recent activity. In this paper we present a framework...