In this project, we consider the safety control problem for Hidden Mode Hybrid Systems (HMHSs), which are a special class of hybrid automata in which the mode is not available for control. For these systems, safety control is a problem with imperfect state information. We are tackling this problem by introducing the notion of non-deterministic discrete information state and by translating the problem to one with perfect state information. The perfect state information control problem is obtained by constructing a new hybrid automaton, whose discrete state is an estimate of the HMHS mode and is, as such, available for control. This problem is being solved by computing the capture set (the complement of the maximal controlled invariant set) and the least restrictive control map for the new hybrid automaton. Termination of the algorithms that compute the capture set is also investigated. The theory is being applied to the development of on-board driver assist systems that prevent collisions at intersections, merges, and roundabouts. |