Integer Parameter Synthesis for Real-Time Systems

Aleksandra Jovanovic (1) , Didier Lime (1) , Olivier Henri Roux (1)

1 LS2N - équipe STR - STR

We provide a subclass of parametric timed au-tomata (PTA) that we can actually and efficiently analyze, and we argue that it retains most of the practical usefulness of PTA for the modeling of real-time systems. The currently most useful known subclass of PTA, L/U automata, has a strong syntactical restriction for practical purposes, and we show that the associated theoretical results are mixed. We therefore advocate for a different restriction scheme: since in classical timed automata, real-valued clocks are always compared to integers for all practical purposes, we also search for parameter values as bounded integers. We show that the problem of the existence of parameter values such that some TCTL property is satisfied is PSPACE-complete. In such a setting, we can of course synthesize all the values of parameters and we give symbolic algorithms, for reachability and unavoidability properties, to do it efficiently, i.e., without an explicit enumeration. This also has the practical advantage of giving the result as symbolic constraints between the parameters. We finally report on a few experimental results to illustrate the practical usefulness of our approach.

Domaines: Informatique [cs]; Théorie et langage formel [cs.FL]

Aleksandra Jovanovic, Didier Lime, Olivier Henri Roux. Integer Parameter Synthesis for Real-Time Systems. IEEE Transactions on Software Engineering, 2015, 41 (5), pp.445-461. ⟨10.1109/TSE.2014.2357445⟩. ⟨hal-02939617⟩