HAT: Analyzing Linear Hybrid Automata as Labelled Transition System

Abstract

Linear Hybrid Automata (LHA) is a natural modeling language for real-time embedded systems. However, due to the existences of both discrete and continuous behaviors, formal analysis of LHA is recognized as a very challenging task. Despite decades of active research, the kinds of LHA problems that can be efficiently analyzed is rather limited. On the other hand, Labelled Linear Transition System (LTS) is a widely used modeling language to describe the state changes of the system before and after certain transitions. Lots of research efforts have been devoted into the verification of LTS models. Many off-the-shelf formal techniques and tools are available for analyzing different kinds of problems for LTS systems. In this paper, we propose to express an LHA as an equivalent LTS model explicitly. Then, we can take advantage of all the off-the-shelf formal checkers of LTS to answer different problems of the LHA model. A prototype tool HAT is implemented under this idea. By integrating typical LTS checkers like ARMC and Interproc, we conduct considerably difficult checking problems like reachability verification, termination analysis, and invariant generation of LHA successfully and efficiently. It shows the open possibility of analyzing more kinds of difficult problems of LHA by LTS checkers easily in the future.