1,369 research outputs found
Improving HyLTL model checking of hybrid systems
The problem of model-checking hybrid systems is a long-time challenge in the
scientific community. Most of the existing approaches and tools are either
limited on the properties that they can verify, or restricted to simplified
classes of systems. To overcome those limitations, a temporal logic called
HyLTL has been recently proposed. The model checking problem for this logic has
been solved by translating the formula into an equivalent hybrid automaton,
that can be analized using existing tools. The original construction employs a
declarative procedure that generates exponentially many states upfront, and can
be very inefficient when complex formulas are involved. In this paper we solve
a technical issue in the construction that was not considered in previous
works, and propose a new algorithm to translate HyLTL into hybrid automata,
that exploits optimized techniques coming from the discrete LTL community to
build smaller automata.Comment: In Proceedings GandALF 2013, arXiv:1307.416
Model checking embedded system designs
We survey the basic principles behind the application of model checking to controller verification and synthesis. A promising development is the area of guided model checking, in which the state space search strategy of the model checking algorithm can be influenced to visit more interesting sets of states first. In particular, we discuss how model checking can be combined with heuristic cost functions to guide search strategies. Finally, we list a number of current research developments, especially in the area of reachability analysis for optimal control and related issues
Deciding the Satisfiability of MITL Specifications
In this paper we present a satisfiability-preserving reduction from MITL
interpreted over finitely-variable continuous behaviors to Constraint LTL over
clocks, a variant of CLTL that is decidable, and for which an SMT-based bounded
satisfiability checker is available. The result is a new complete and effective
decision procedure for MITL. Although decision procedures for MITL already
exist, the automata-based techniques they employ appear to be very difficult to
realize in practice, and, to the best of our knowledge, no implementation
currently exists for them. A prototype tool for MITL based on the encoding
presented here has, instead, been implemented and is publicly available.Comment: In Proceedings GandALF 2013, arXiv:1307.416
Weak Alternating Timed Automata
Alternating timed automata on infinite words are considered. The main result
is a characterization of acceptance conditions for which the emptiness problem
for these automata is decidable. This result implies new decidability results
for fragments of timed temporal logics. It is also shown that, unlike for MITL,
the characterisation remains the same even if no punctual constraints are
allowed
Integrated Modeling and Verification of Real-Time Systems through Multiple Paradigms
Complex systems typically have many different parts and facets, with
different characteristics. In a multi-paradigm approach to modeling, formalisms
with different natures are used in combination to describe complementary parts
and aspects of the system. This can have a beneficial impact on the modeling
activity, as different paradigms an be better suited to describe different
aspects of the system. While each paradigm provides a different view on the
many facets of the system, it is of paramount importance that a coherent
comprehensive model emerges from the combination of the various partial
descriptions. In this paper we present a technique to model different aspects
of the same system with different formalisms, while keeping the various models
tightly integrated with one another. In addition, our approach leverages the
flexibility provided by a bounded satisfiability checker to encode the
verification problem of the integrated model in the propositional
satisfiability (SAT) problem; this allows users to carry out formal
verification activities both on the whole model and on parts thereof. The
effectiveness of the approach is illustrated through the example of a
monitoring system.Comment: 27 page
Temporal Reasoning Through Automatic Translation of tock-CSP into Timed Automata
In this work, we present an approach for automatic translation of tock-CSP into Timed Automata (TA) for Uppaal to facilitate using Uppaal in reasoning about temporal specifications of tock-CSP models. The process algebra tock-CSP provides textual notations for modelling discrete-time behaviours, with the support of tools for automatic verification. Automatic verification of TA with a graphical notation is supported by Uppaal. The two approaches provide facilities for automatic verification. For instance, liveness requirements are difficult to specify with the constructs of tock-CSP, but they are easy to specify and verify in Uppaal. We have developed a translation technique and a tool based for translating tock-CSP into a network of small TAs for capturing the compositional structure of tock-CSP. For validating the rules, we begin with an experimental approach based on finite approximations to trace sets. Then, we explore using structural induction to establish the correctness
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