Verification of Giotto based embedded control systems

• Authors: Rajiv Kumar Poddar;Purandar Bhaduri
• Venue: Nordic Journal of Computing
• Year: 2006

An implementation of a control system design may not preserve the functional and timing requirements of the application. Our goal is to verify that an implementation meets the high-level timing and functional specifications of a control application. We take Giotto as the implementation model, and verify Giotto models using UPPAAL, a tool box for modelling, simulation and verification of timed automata. We present a translation scheme for building timed automata in UPPAAL for real-time systems written in Giotto. When translating Giotto to timed automata, we consider timing constraints imposed by the control application, as well as the characteristics of the implementation platform. These timing constraints take into account execution times of atomic tasks, worst case execution times, worst case communication times and jitters. The timed models obtained in this manner are analysed and the corresponding system's functional and timing properties are verified using UPPAAL. We develop the translation scheme in two phases. The first is applicable to basic Giotto models; the latter considers Giotto models with annotations providing information on scheduling and resource allocation. We demonstrate both phases of the scheme by applying it to two Giotto models - an elevator control and a hovercraft control system. The two systems vary in their complexity, their functional and non-functional requirements. We report on the results of our verification of the Giotto models.