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33
Samplingbased motion planning with temporal goals
 in IEEE International Conference on Robotics and Automation (ICRA), 2010. Proceedings
, 2010
"... Abstract — This paper presents a geometrybased, multilayered synergistic approach to solve motion planning problems for mobile robots involving temporal goals. The temporal goals are described over subsets of the workspace (called propositions) using temporal logic. A multilayered synergistic fram ..."
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Cited by 47 (5 self)
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Abstract — This paper presents a geometrybased, multilayered synergistic approach to solve motion planning problems for mobile robots involving temporal goals. The temporal goals are described over subsets of the workspace (called propositions) using temporal logic. A multilayered synergistic framework has been proposed recently for solving planning problems involving significant discrete structure. In this framework, a highlevel planner uses a discrete abstraction of the system and the exploration information to suggest feasible highlevel plans. A lowlevel samplingbased planner uses the physical model of the system, and the suggested highlevel plans, to explore the statespace for feasible solutions. In this paper, we advocate the use of geometry within the above framework to solve motion planning problems involving temporal goals. We present a technique to construct the discrete abstraction using the geometry of the obstacles and the propositions defined over the workspace. Furthermore, we show through experiments that the use of geometry results in significant computational speedups compared to previous work. Traces corresponding to trajectories of the system are defined employing the sampling interval used by the lowlevel algorithm. The applicability of the approach is shown for secondorder nonlinear robot models in challenging workspace environments with obstacles, and for a variety of temporal logic specifications. I.
Linear encodings of bounded LTL model checking
 Logical Methods in Computer Science, 2(5):1–64, 2006. Matteo Pradella, Angelo Morzenti, and Pierluigi San Pietro
"... ABSTRACT. We consider the problem of bounded model checking (BMC) for linear temporal logic (LTL). We present several efficient encodings that have size linear in the bound. Furthermore, we show how the encodings can be extended to LTL with past operators (PLTL). The generalised encoding is still of ..."
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Cited by 27 (3 self)
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ABSTRACT. We consider the problem of bounded model checking (BMC) for linear temporal logic (LTL). We present several efficient encodings that have size linear in the bound. Furthermore, we show how the encodings can be extended to LTL with past operators (PLTL). The generalised encoding is still of linear size, but cannot detect minimal length counterexamples. By using the virtual unrolling technique minimal length counterexamples can be captured, however, the size of the encoding is quadratic in the specification. We also extend virtual unrolling to Büchi automata, enabling them to accept minimal length counterexamples. Our BMC encodings can be made incremental in order to benefit from incremental SAT technology. With fairly small modifications the incremental encoding can be further enhanced with a termination check, allowing us to prove properties with BMC. An analysis of the livenesstosafety transformation reveals many similarities to the BMC encodings in this paper. We conduct experiments to determine the advantage of employing dedicated BMC encodings for PLTL over combining more general but potentially less efficient approaches with BMC: the livenesstosafety transformation with invariant checking and Büchi automata with fair cycle detection.
Falsification of LTL Safety Properties in Hybrid Systems
"... Abstract. This paper develops a novel computational method for the falsification of safety properties specified by syntactically safe linear temporal logic (LTL) formulas φ for hybrid systems with general nonlinear dynamics and input controls. The method is based on an effective combination of robot ..."
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Cited by 21 (5 self)
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Abstract. This paper develops a novel computational method for the falsification of safety properties specified by syntactically safe linear temporal logic (LTL) formulas φ for hybrid systems with general nonlinear dynamics and input controls. The method is based on an effective combination of robot motion planning and model checking. Experiments on a hybrid robotic system benchmark with nonlinear dynamics show significant speedup over related work. The experiments also indicate significant speedup when using minimized DFA instead of nonminimized NFA, as obtained by standard tools, for representing the violating prefixes of φ. 1
On the construction of fine automata for safety properties
 In Proc. 4th ATVA, LNCS 4218
, 2006
"... Abstract. Of special interest in formal verification are safety properties, which assert that the system always stays within some allowed region. Each safety property ψ can be associated with a set of bad prefixes: a set of finite computations such that an infinite computation violates ψ iff it has ..."
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Cited by 14 (4 self)
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Abstract. Of special interest in formal verification are safety properties, which assert that the system always stays within some allowed region. Each safety property ψ can be associated with a set of bad prefixes: a set of finite computations such that an infinite computation violates ψ iff it has a prefix in the set. By translating a safety property to an automaton for its set of bad prefixes, verification can be reduced to reasoning about finite words: a system is correct if none of its computations has a bad prefix. Checking the latter circumvents the need to reason about cycles and simplifies significantly methods like symbolic fixedpoint based verification, bounded model checking, and more. A drawback of the translation lies in the size of the automata: while the translation of a safety LTL formula ψ to a nondeterministic Büchi automaton is exponential, its translation to a tight badprefix automaton — one that accepts all the bad prefixes of ψ, is doubly exponential. Kupferman and Vardi showed that for the purpose of verification, one can replace the tight automaton by a fine automaton — one that accepts at least one bad prefix of each infinite computation that violates ψ. They also showed that for many safety LTL formulas, a fine automaton has the same structure as the Büchi automaton for the formula. The problem of constructing fine automata for general safety LTL formulas was left open. In this paper we solve this problem and show that while a fine automaton cannot, in general, have the same structure as the Büchi automaton for the formula, the size of a fine automaton is still only exponential in the length of the formula. 1
Deterministic Dynamic Monitors for LinearTime Assertions
 In Proceedings of International ICSC Symposium on MultiAgents and Mobile Agents in Virtual Organizations and ECommerce (MAMA'2000
, 2006
"... We describe a framework for dynamic verification of temporal assertions based on assertion compilation into deterministic automata. The novelty of our approach is that it allows efficient dynamic verification of general linear temporal formulas written in formal property specification languages s ..."
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Cited by 12 (4 self)
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We describe a framework for dynamic verification of temporal assertions based on assertion compilation into deterministic automata. The novelty of our approach is that it allows efficient dynamic verification of general linear temporal formulas written in formal property specification languages such as LTL, ForSpec, PSL, and SVA, while the existing approaches are applicable to limited subsets only. We also show an advantage of the described framework over industrial simulators, which typically use transactionbased verification. Another advantage of our approach is its ability to use deterministic checkers directly for hardware emulation. Finally, we compare the deterministic compilation with the OBDDbased onthefly simulation of deterministic automata. We show that although the OBDDbased simulation method is much slower, the two methods may be efficiently combined for hybrid simulation, when the RTL signals in assertions are mixed with symbolic variables.
Motion planning with hybrid dynamics and temporal goals
 In Decision and Control, IEEE Conf. on
, 2010
"... Abstract — In this paper, we consider the problem of motion planning for mobile robots with nonlinear hybrid dynamics, and highlevel temporal goals. We use a multilayered synergistic framework that has been proposed recently for solving planning problems involving hybrid systems and highlevel tem ..."
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Cited by 11 (4 self)
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Abstract — In this paper, we consider the problem of motion planning for mobile robots with nonlinear hybrid dynamics, and highlevel temporal goals. We use a multilayered synergistic framework that has been proposed recently for solving planning problems involving hybrid systems and highlevel temporal goals. In that framework, a highlevel planner employs a userdefined discrete abstraction of the hybrid system as well as exploration information to suggest highlevel plans. A lowlevel samplingbased planner uses the dynamics of the hybrid system and the suggested highlevel plans to explore the statespace for feasible solutions. In previous work, we have proposed a geometrybased approach for the construction of the discrete abstraction for the case when the robot is modeled as a continuous system. Here, we extend the approach for the construction of the discrete abstraction to the case when the robot is modeled as nonlinear hybrid system. To use the resulting abstraction more efficiently, we also propose a lazysearch approach for highlevel planning that reduces the size of the search space by reusing previously constructed highlevel plans for initializing the search. Our proposed techniques result in computational speedups of close to 10 times over other possible approaches for secondorder nonlinear hybrid robot models in challenging workspace environments with obstacles and for a variety of temporal logic specifications. I.
The LIME Interface Specification Language and Runtime Monitoring Tool ⋆
"... Abstract. This paper describes an interface specification language designed in the LIME project (LIME ISL) and the supporting runtime monitoring tool. The interface specification language is tailored for the Java programming language and supports two kinds of specifications: (i) call specifications ..."
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Cited by 7 (0 self)
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Abstract. This paper describes an interface specification language designed in the LIME project (LIME ISL) and the supporting runtime monitoring tool. The interface specification language is tailored for the Java programming language and supports two kinds of specifications: (i) call specifications that specify requirements for the allowed call sequences to a Java object instance and (ii) return specifications that specify the allowed behaviors of the Java object instance. Both the call and return specifications can be expressed with Java annotations in several different ways: as past time LTL formulas, as (safety) future LTL formulas, as regular expressions, and as nondeterministic finite automata. We also describe the supporting LIME interface monitoring tool which is an open source implementation of runtime monitoring for the interface specifications implemented using AspectJ. 1
Incremental control synthesis in probabilistic environments with temporal logic constraints
 In Proc. of 51st IEEE Conf. on Decision and Control (CDC
, 2012
"... Abstract — In this paper, we present a method for optimal control synthesis of a plant that interacts with a set of agents in a graphlike environment. The control specification is given as a temporal logic statement about some properties that hold at the vertices of the environment. The plant is as ..."
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Cited by 7 (2 self)
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Abstract — In this paper, we present a method for optimal control synthesis of a plant that interacts with a set of agents in a graphlike environment. The control specification is given as a temporal logic statement about some properties that hold at the vertices of the environment. The plant is assumed to be deterministic, while the agents are probabilistic Markov models. The goal is to control the plant such that the probability of satisfying a syntactically cosafe Linear Temporal Logic formula is maximized. We propose a computationally efficient incremental approach based on the fact that temporal logic verification is computationally cheaper than synthesis. We present a casestudy where we compare our approach to the classical nonincremental approach in terms of computation time and memory usage. I.
BMC via OntheFly Determinization
, 2003
"... The paper develops novel bounded model checking techniques for labelled transition systems. The aim is to increase the e#ciency of BMC by exploiting the inherent concurrency in the product of LTSs in order to cover more executions of the product within a given bound. This is done by considering a no ..."
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Cited by 6 (1 self)
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The paper develops novel bounded model checking techniques for labelled transition systems. The aim is to increase the e#ciency of BMC by exploiting the inherent concurrency in the product of LTSs in order to cover more executions of the product within a given bound. This is done by considering a nonstandard execution model, step executions, where multiple actions can take place simultaneously and where component LTSs are determinized onthefly, i.e., a component may be in a set of states in a step instead of in just one as in standard interleaving executions. Step executions can be further restricted to a subclass called process executions without loosing reachable states. For bounded model checking of reachability properties of the product of LTSs the paper presents translation schemes from LTSs to a constrained Boolean circuit such that satisfying valuations of the circuit correspond to step (process) executions of the product. The translation schemes have been implemented and some experimental comparisons performed. The results show that the bound needed for step and process executions is in most cases lower than in interleaving executions and that the running time of the model checker using process executions is smaller than using steps. Moreover, the performance compares favorably to a stateoftheart interleaving BMC implementation in the NuSMV system.
Manipulating LTL formulas using Spot 1.0
"... Abstract. We present a collection of commandline tools designed to generate, filter, convert, simplify, lists of Lineartime Temporal Logic formulas. These tools were introduced in the release 1.0 of Spot, and we believe they should be of interest to anybody who has to manipulate LTL formulas. We f ..."
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Cited by 6 (1 self)
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Abstract. We present a collection of commandline tools designed to generate, filter, convert, simplify, lists of Lineartime Temporal Logic formulas. These tools were introduced in the release 1.0 of Spot, and we believe they should be of interest to anybody who has to manipulate LTL formulas. We focus on two tools in particular: ltlfilt, to filter and transform formulas, and ltlcross to crosscheck LTLtoBüchiAutomata translators. 1