Mover, S., Cimatti, A., Tiwari, A., & Tonetta, S. (2013, 29 September – 4 October). Time-aware relational abstractions for hybrid systems. Paper presented at the International Conference on Embedded Software (EMSOFT ’13), Montreal, Canada.
Hybrid Systems model both discrete switches and continuous dynamics and are suitable to represent embedded systems where discrete controllers interact with a physical plant. Relational abstraction is a new approach for verifying hybrid systems. In relational abstraction, the continuous dynamics in each location of the hybrid system is abstracted by a binary relation that relates the current value of the continuous variables with all future values of the variables that are reachable after a time elapse (continuous) transition. The abstract system is an infinite-state system, which can be verified using k-induction or abstract interpretation. Existing techniques for computing relational abstractions are time-agnostic: they do not construct any relationship between the state variables and the time elapsed during the continuous evolution. Time-agnostic abstractions cannot verify timing properties. We present a technique to compute a time-aware relational abstraction for verifying (timing-related) safety properties of cyber-physical systems. We show the effectiveness of the new abstraction on several case studies on which the previous techniques fail.