Controllers for reachability specifications for hybrid systems

The problem of systematically synthesizing hybrid controllers which satisfy multiple control objectives is considered. We present a technique, based o n the principles of optimal control, for determining the class of least res trictive controllers that satisfies the most important objective (which we refer to as safety). The system performance with respect to lower priority objectives (which we refer to as efficiency) can then be optimized within t his class. We motivate our approach by showing how the proposed synthesis t echnique simplifies to well-known results from supervisory control and purs uit evasion games when restricted to purely discrete and purely continuous systems respectively. We then illustrate the application of this technique to two examples, one hybrid (the steam boiler benchmark problem), and one p rimarily continuous (a flight vehicle management system with discrete fligh t modes). (C) 1999 Elsevier Science Ltd. All rights reserved.