A Branch-and-bound Algorithm for Determining Discrete Changes for Hybrid Constraint Solver HyLaGI

Abstract

Hybrid systems are dynamical systems involving continuous and discrete changes. Various models such as cyber-physical systems and control systems can be discribed as hybrid systems. We are developing HydLa, a modeling language of hybrid system and its symbolic simulator HyLaGI. HyLaGI performs exhaustive search to find time points of discrete changes, but its computation becomes a bottleneck for some programs having a large number of guarded constraints. In this research, we propose a efficient search method using a branch-and-bound algorithm and implement a prototype. The result of simple experiment shows that our approach reduces most of the search cost in the motivating example.