Reachability analysis for timed automata using max-plus algebra (original) (raw)

SAT-based Reachability Checking for Timed Automata with Diagonal Constraints

Fundamenta Informaticae, 2005

Reachability analysis for timed automata using SAT-based methods was considered in many papers, occurring to be a very efficient model checking technique. In this paper we show how to apply this method of verification to timed automata with discrete data, i.e., to standard timed automata augmented with integer variables. The theoretical description is supported by some preliminary experimental results.

SAT-Based Reachability Checking for Timed Automata with Discrete Data

Fundamenta Informaticae, 2007

Reachability analysis for timed automata using SAT-based methods was considered in many papers, occurring to be a very efficient model checking technique. In this paper we show how to apply this method of verification to timed automata with discrete data, i.e., to standard timed automata augmented with integer variables. The theoretical description is supported by some preliminary experimental results.

Checking reachability properties for Timed Automata via SAT

Fundamenta Informaticae, 2002

Abstract. The paper deals with the problem of checking reachability for timed automata. The main idea consists in combining the well-know forward reachability algorithm and the Bounded Model Checking (BMC) method. In order to check reachability of a state satisfying some desired property, first the transition relation of a timed automaton is unfolded iteratively to some depth and encoded as a propositional formula. Next, the desired property is translated to a propositional formula and the satisfiability of the conjunction of the two ...

Lower and upper bounds in zone-based abstractions of timed automata

International Journal on Software Tools for Technology Transfer, 2006

The semantics of timed automata is defined using an infinite-state transition system. For verification purposes, one usually uses zone based abstractions w.r.t. the maximal constants to which clocks of the timed automaton are compared. We show that by distinguishing maximal lower and upper bounds, significantly coarser abstractions can be obtained. We show soundness and completeness of the new abstractions w.r.t. reachability. We demonstrate how information about lower and upper bounds can be used to optimise the algorithm for bringing a difference bound matrix into normal form. Finally, we experimentally demonstrate that the new techniques dramatically increases the scalability of the realtime model checker Uppaal.

Multi-Core Reachability for Timed Automata

2012

Model checking of timed automata is a widely used technique. But in order to take advantage of modern hardware, the algorithms need to be parallelized. We present a multi-core reachability algorithm for the more general class of well-structured transition systems, and an implementation for timed automata.

A new algorithm for reachability analysis of hybrid automata

Abstract. A new algorithm is presented for computing approximations of the reached sets of linear hybrid automata. First, we present some new theoretical results on termination of a class of reachability algorithms, which includes Botchkarev's, based on ellipsoidal calculus. The main contribution of the paper is a revised reachability computation that avoids the approximations caused by the union operation in the discretized flow tube estimation.

Model checking via reachability testing for timed automata

In this paper we develop an approach to model-checking for timed automata via reachability testing. As our specification formalism, we consider a dense-time property language with clocks. This property language may be used to express safety and bounded liveness properties of real-time systems. We show how to automatically synthesize, for every formula ϕ, a test automaton Tϕ in such a way that checking whether a system S satisfies the property ϕ can be reduced to a reachability question over the system obtained by making Tϕ interact with S.

Symbolic Reachability Analysis of High Dimensional Max-Plus Linear Systems

IFAC-PapersOnLine

This work discusses the reachability analysis (RA) of Max-Plus Linear (MPL) systems, a class of continuous-space, discrete-event models defined over the max-plus algebra. Given the initial and target sets, we develop algorithms to verify whether there exist trajectories of the MPL system that, starting from the initial set, eventually reach the target set. We show that RA can be solved symbolically by encoding the MPL system, as well as initial and target sets into difference logic, and then checking the satisfaction of the resulting logical formula via an off-the-shelf satisfiability modulo theories (SMT) solver. The performance and scalability of the developed SMT-based algorithms are shown to clearly outperform state-ofthe-art RA algorithms for MPL systems, newly allowing to investigate RA of high-dimensional MPL systems: the verification of models with more than 100 continuous variables shows the applicability of these techniques to MPL systems of industrial relevance.