23,895 research outputs found
Traffic Network Control from Temporal Logic Specifications
We propose a framework for generating a signal control policy for a traffic
network of signalized intersections to accomplish control objectives
expressible using linear temporal logic. By applying techniques from model
checking and formal methods, we obtain a correct-by-construction controller
that is guaranteed to satisfy complex specifications. To apply these tools, we
identify and exploit structural properties particular to traffic networks that
allow for efficient computation of a finite state abstraction. In particular,
traffic networks exhibit a componentwise monotonicity property which allows
reach set computations that scale linearly with the dimension of the continuous
state space
Formal Synthesis of Control Strategies for Positive Monotone Systems
We design controllers from formal specifications for positive discrete-time
monotone systems that are subject to bounded disturbances. Such systems are
widely used to model the dynamics of transportation and biological networks.
The specifications are described using signal temporal logic (STL), which can
express a broad range of temporal properties. We formulate the problem as a
mixed-integer linear program (MILP) and show that under the assumptions made in
this paper, which are not restrictive for traffic applications, the existence
of open-loop control policies is sufficient and almost necessary to ensure the
satisfaction of STL formulas. We establish a relation between satisfaction of
STL formulas in infinite time and set-invariance theories and provide an
efficient method to compute robust control invariant sets in high dimensions.
We also develop a robust model predictive framework to plan controls optimally
while ensuring the satisfaction of the specification. Illustrative examples and
a traffic management case study are included.Comment: To appear in IEEE Transactions on Automatic Control (TAC) (2018), 16
pages, double colum
A Learning Based Approach to Control Synthesis of Markov Decision Processes for Linear Temporal Logic Specifications
We propose to synthesize a control policy for a Markov decision process (MDP)
such that the resulting traces of the MDP satisfy a linear temporal logic (LTL)
property. We construct a product MDP that incorporates a deterministic Rabin
automaton generated from the desired LTL property. The reward function of the
product MDP is defined from the acceptance condition of the Rabin automaton.
This construction allows us to apply techniques from learning theory to the
problem of synthesis for LTL specifications even when the transition
probabilities are not known a priori. We prove that our method is guaranteed to
find a controller that satisfies the LTL property with probability one if such
a policy exists, and we suggest empirically with a case study in traffic
control that our method produces reasonable control strategies even when the
LTL property cannot be satisfied with probability one
A provably correct MPC approach to safety control of urban traffic networks
Model predictive control (MPC) is a popular strategy for urban traffic management that is able to incorporate physical and user defined constraints. However, the current MPC methods rely on finite horizon predictions that are unable to guarantee desirable behaviors over long periods of time. In this paper we design an MPC strategy that is guaranteed to keep the evolution of a network in a desirable yet arbitrary -safe- set, while optimizing a finite horizon cost function. Our approach relies on finding a robust controlled invariant set inside the safe set that provides an appropriate terminal constraint for the MPC optimization problem. An illustrative example is included.This work was partially supported by the NSF under grants CPS-1446151 and CMMI-1400167. (CPS-1446151 - NSF; CMMI-1400167 - NSF
Modeling and Verification of Agent based Adaptive Traffic Signal using Symbolic Model Verifier
This paper addresses the issue of modeling and verification of a Multi Agent
System (MAS) scenario. We have considered an agent based adaptive traffic
signal system. The system monitors the smooth flow of traffic at intersection
of two road segment. After describing how the adaptive traffic signal system
can efficiently be used and showing its advantages over traffic signals with
predetermined periods, we have shown how we can transform this scenario into
Finite State Machine (FSM). Once the system is transformed into a FSM, we have
verified the specifications specified in Computational Tree Logic(CTL) using
NuSMV as a model checking tool. Simulation results obtained from NuSMV showed
us whether the system satisfied the specifications or not. It has also showed
us the state where the system specification does not hold. Using which we
traced back our system to find the source, leading to the specification
violation. Finally, we again verified the modified system with NuSMV for its
specifications.Comment: 13 pages, 6 figures, Submitted to International Journal of Computer
Application (IJCA
Model Checking Classes of Metric LTL Properties of Object-Oriented Real-Time Maude Specifications
This paper presents a transformational approach for model checking two
important classes of metric temporal logic (MTL) properties, namely, bounded
response and minimum separation, for nonhierarchical object-oriented Real-Time
Maude specifications. We prove the correctness of our model checking
algorithms, which terminate under reasonable non-Zeno-ness assumptions when the
reachable state space is finite. These new model checking features have been
integrated into Real-Time Maude, and are used to analyze a network of medical
devices and a 4-way traffic intersection system.Comment: In Proceedings RTRTS 2010, arXiv:1009.398
Synthesis of Distributed Longitudinal Control Protocols for a Platoon of Autonomous Vehicles
We develop a framework for control protocol synthesis for a platoon of autonomous vehicles subject to temporal logic specifications. We describe the desired behavior of the platoon in a set of linear temporal logic formulas, such as collision avoidance, close spacing or comfortability. The problem of decomposing a global specification for the platoon into distributed specification for each pair of adjacent vehicles is hard to solve. We use the invariant specifications to tackle this problem and the decomposition is proved to be scalable.. Based on the specifications in Assumption/Guarantee form, we can construct a two-player game (between the vehicle and its closest leader) locally to automatically synthesize a controller protocol for each vehicle. Simulation example for a distributed vehicles control problem is also shown
Reactive Rules for Emergency Management
The goal of the following survey on Event-Condition-Action (ECA) Rules is to come to a common understanding and intuition on this topic within EMILI. Thus it does not give an academic overview on Event-Condition-Action Rules which would be valuable for computer scientists only. Instead the survey tries to introduce Event-Condition-Action Rules and their use for emergency management based on real-life examples from the use-cases identified in Deliverable 3.1. In this way we hope to address both, computer scientists and security experts, by showing how the Event-Condition-Action Rule technology can help to solve security issues in emergency management. The survey incorporates information from other work packages, particularly from Deliverable D3.1 and its Annexes, D4.1, D2.1 and D6.2 wherever possible
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