Simulation of hybrid systems based on hierarchical interval constraints

We propose a framework called HydLa for simple modeling and reliable simulation of hybrid systems which involve discrete and continuous changes over time. HydLa employs interval constraints as a central principle to express uncertainties in modeling, error bounds in the computation of nonlinear continuous changes, and reachable state sets that play key roles in verification. In this research, we propose a modeling language with hierarchical interval constraints to facilitate well-defined modeling, and its implementation which uses machine-representable interval constraints to enclose computation errors with intervals or boxes. The implementation is based on the integration of a consistency technique for nonlinear interval constraints and a technique for solving ordinary differential equations. We also present a method for solving constraint hierarchies among interval constraints.