2,892 research outputs found
Algorithmic Verification of Continuous and Hybrid Systems
We provide a tutorial introduction to reachability computation, a class of
computational techniques that exports verification technology toward continuous
and hybrid systems. For open under-determined systems, this technique can
sometimes replace an infinite number of simulations.Comment: In Proceedings INFINITY 2013, arXiv:1402.661
Model Predictive Control for Signal Temporal Logic Specification
We present a mathematical programming-based method for model predictive
control of cyber-physical systems subject to signal temporal logic (STL)
specifications. We describe the use of STL to specify a wide range of
properties of these systems, including safety, response and bounded liveness.
For synthesis, we encode STL specifications as mixed integer-linear constraints
on the system variables in the optimization problem at each step of a receding
horizon control framework. We prove correctness of our algorithms, and present
experimental results for controller synthesis for building energy and climate
control
Reducing Clocks in Timed Automata while Preserving Bisimulation
Model checking timed automata becomes increasingly complex with the increase
in the number of clocks. Hence it is desirable that one constructs an automaton
with the minimum number of clocks possible. The problem of checking whether
there exists a timed automaton with a smaller number of clocks such that the
timed language accepted by the original automaton is preserved is known to be
undecidable. In this paper, we give a construction, which for any given timed
automaton produces a timed bisimilar automaton with the least number of clocks.
Further, we show that such an automaton with the minimum possible number of
clocks can be constructed in time that is doubly exponential in the number of
clocks of the original automaton.Comment: 28 pages including reference, 8 figures, full version of paper
accepted in CONCUR 201
The Power of Proofs: New Algorithms for Timed Automata Model Checking (with Appendix)
This paper presents the first model-checking algorithm for an expressive
modal mu-calculus over timed automata, , and reports performance results for an implementation.
This mu-calculus contains extended time-modality operators and can express all
of TCTL. Our algorithmic approach uses an "on-the-fly" strategy based on proof
search as a means of ensuring high performance for both positive and negative
answers to model-checking questions. In particular, a set of proof rules for
solving model-checking problems are given and proved sound and complete; we
encode our algorithm in these proof rules and model-check a property by
constructing a proof (or showing none exists) using these rules. One noteworthy
aspect of our technique is that we show that verification performance can be
improved with \emph{derived rules}, whose correctness can be inferred from the
more primitive rules on which they are based. In this paper, we give the basic
proof rules underlying our method, describe derived proof rules to improve
performance, and compare our implementation of this model checker to the UPPAAL
tool.Comment: This is the preprint of the FORMATS 2014 paper, but this is the full
version, containing the Appendix. The final publication is published from
Springer, and is available at
http://link.springer.com/chapter/10.1007%2F978-3-319-10512-3_9 on the
Springer webpag
Tropical Fourier-Motzkin elimination, with an application to real-time verification
We introduce a generalization of tropical polyhedra able to express both
strict and non-strict inequalities. Such inequalities are handled by means of a
semiring of germs (encoding infinitesimal perturbations). We develop a tropical
analogue of Fourier-Motzkin elimination from which we derive geometrical
properties of these polyhedra. In particular, we show that they coincide with
the tropically convex union of (non-necessarily closed) cells that are convex
both classically and tropically. We also prove that the redundant inequalities
produced when performing successive elimination steps can be dynamically
deleted by reduction to mean payoff game problems. As a complement, we provide
a coarser (polynomial time) deletion procedure which is enough to arrive at a
simply exponential bound for the total execution time. These algorithms are
illustrated by an application to real-time systems (reachability analysis of
timed automata).Comment: 29 pages, 8 figure
Interpolation in local theory extensions
In this paper we study interpolation in local extensions of a base theory. We
identify situations in which it is possible to obtain interpolants in a
hierarchical manner, by using a prover and a procedure for generating
interpolants in the base theory as black-boxes. We present several examples of
theory extensions in which interpolants can be computed this way, and discuss
applications in verification, knowledge representation, and modular reasoning
in combinations of local theories.Comment: 31 pages, 1 figur
- …