976documents trouvés
Exponential stability of a PI plus reset integrator controller by a sampled-data system approach
M.A.DAVO, F.GOUAISBAUT, A.BANOS, S.TARBOURIECH, A.SEURET
GIPSA-Lab, MAC, Murcia
Revue Scientifique : Nonlinear Analysis: Hybrid Systems , Vol.29, pp.133-146, Août 2018 , N° 18133
Lien : https://hal.laas.fr/hal-01799415
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The paper deals with the stability analysis of time delay reset control systems, for which the resetting law is assumed to satisfy a time-dependent condition. A stability analysis of the closed-loop system is performed based on an appropriate sampled-data system. New linear matrix inequality (LMI) conditions are proposed to ensure the exponential stability of the closed-loop system resulting from the connection of a plant with a proportional and integral controller together with a reset integrator (PI+RI).
Local Input-to-State Stabilization of 1-D Linear Reaction-Diffusion Equation with Bounded Feedback
A.TANWANI, S.MARX, C.PRIEUR
MAC, GIPSA-Lab
Manifestation avec acte : International Symposium on Mathematical Theory of Networks and Systems ( MTNS ) 2018 du 16 juillet au 20 juillet 2018, Hong Kong (Chine), Juillet 2018, 6p. , N° 18143
Lien : https://hal.laas.fr/hal-01785104
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The problem of robust stabilization with bounded feedback control is considered for a scalar reaction-diffusion system with uncertainties in the dynamics. The maximum value of the control input acting on one of the boundary points has to respect a given bound at each time instant. It is shown that, if the initial condition and the disturbance satisfy the certain bounds (computed as a function of the bound imposed on the control input), then the proposed control respects the desired saturation level and renders the closed-loop system locally input-to-state stable, that is, the trajectories with certain bound on the initial condition converge to a ball parameterized by certain norm of the disturbance.
Closeness-Centrality-Based Synchronization Criteria for Complex Dynamical Networks With Interval Time-Varying Coupling Delays
M.PARK, S.H.LEE, O.KWON, A.SEURET
Chungbuk Natinonal University, MAC
Revue Scientifique : IEEE Transactions on Cybernetics, Vol.48, N°7, pp.2192-2205, Juillet 2018, doi 10.1109/TCYB.2017.2729164 , N° 17535
Lien : https://hal.archives-ouvertes.fr/hal-01699188
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This paper investigates synchronization in complex dynamical networks (CDNs) with interval time-varying delays. The CDNs are representative of systems composed of a large number of interconnected dynamical units, and for the purpose of the mathematical analysis, the leading work is to model them as graphs whose nodes represent the dynamical units. At this time, we take note of the importance of each node in networks. One way, in this paper, is that the closeness-centrality mentioned in the field of social science is grafted onto the CDNs. By constructing a suitable Lyapunov-Krasovskii functional, and utilizing some mathematical techniques, the sufficient and closeness-centrality-based conditions for synchronization stability of the networks are established in terms of linear matrix inequalities. Ultimately, the use of the closeness-centrality can be weighted with regard to not only the interconnection relation among the nodes, which was utilized in the existing works but also more information about nodes. Here, the centrality will be added as the concerned information. Moreover, to avoid the computational burden causing the nonconvex term including the square of the time-varying delay, how to deal with it is applied by estimating it to the convex term including time-varying delay. Finally, two illustrative examples are given to show the advantage of the closeness-centrality in point of the robustness on time-delay.
New model transformations for the stability analysis of time-delay systems
M.SAFI, L.BAUDOUIN, A.SEURET
ISI, MAC
Manifestation avec acte : IFAC Workshop on Time Delay Systems ( TDS ) 2018 du 28 juin au 30 juin 2018, Budapest (Hongrie), Juin 2018, 6p. , N° 18137
Lien : https://hal.laas.fr/hal-01799394
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This paper deals with the stability analysis of time delay systems based on continuous-time approach. The originality of the present paper relies on the construction of several models for a same time-delay systems using the interconnection of an ordinary differential equation and a transport partial differential equation. The stability analysis is then performed using a Lyapunov functional. These models are constructed in order to first reduce potentially the complexity of the resulting stability conditions. Second several models are build in order to be interpreted as a discretization scheme as the one usually used in the Lyapunov functional. The proposed result can be seen as a generalized (N − M) discretization which consists in both a time-discretization of the delay interval into M sub-intervals, and the projection of the state function within each sub-interval on the Legendre polynomials of degree less than N. The efficiency of this novel approach is illustrated on an academic example.
Data Instance generator and optimization models for evacuation planning in the event of wildfire
C.ARTIGUES, E.HEBRARD, Y.PENCOLE, A.SCHUTT, P.STUCKEY
ROC, DISCO, CSIRO, Univ of Melbourne
Rapport LAAS N°18155, Juin 2018, 18p.
Lien : https://hal.archives-ouvertes.fr/hal-01814063
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One critical part of decision support during the response phase to a wildfire is the ability to perform large-scale evacuation planning. While in practice most evacuation planning is principally designed by experts using simple heuristic approaches or scenario simulations, more recently optimization approaches to evacuation planning have been carried out, notably in the context of floodings. Evacuation planning in case of wildfires is much harder as wildfire propagations are inherently less predictable than floods. This paper present a new optimization model for evacuation planning in the event of wildfire aiming at maximizing the temporal safety margin between the evac-uees and the actual or potential wildfire front. As a first contribution, an open-source data instance generator based on road network generation via quadtrees and a basic fire propagation model is proposed to the community. As a second contribution we propose 0–1 integer programming and constraint programming formulations enhanced with a 1 simple compression heuristic that are compared on 240 problem instances build by the generator. The results show that the generated instances are computationally challenging and that the contraint programming framework obtains the best performance.
SRide: A Privacy-Preserving Ridesharing System
U.M.AIVODJI, K.HUGUENIN, M.J.HUGUET, M.O.KILLIJIAN
TSF, HEC Lausanne, ROC
Manifestation avec acte : ACM Conference on Security and Privacy in Wireless and Mobile Networks ( WiSec ) 2018 du 18 juin au 20 juin 2018, Stockholm (Suède), Juin 2018 , N° 18094
Lien : https://hal.archives-ouvertes.fr/hal-01762436
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143253GeoSafe – Evacuation planning problems
C.ARTIGUES, E.HEBRARD, Y.PENCOLE, A.SCHUTT, P.STUCKEY
ROC, DISCO, CSIRO, Univ of Melbourne
Rapport LAAS N°18154, Juin 2018, 10p.
Lien : https://hal.archives-ouvertes.fr/hal-01814177
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This paper aims at identifying new challenging variants of the evacuation planning problems, especially in case of bush fires, based on exchanges with practitioners in the context of the GeoSafe project. A large amount of work has been carried out at NICTA mainly in the context of floodings, which can be easily transposed to evacuation in case of fires. .We present a state-of-the-art review of these papers and we provide new research directions for the GeoSafe project.
A Study of Evacuation Planning for Wildfires
C.ARTIGUES, E.HEBRARD, Y.PENCOLE, A.SCHUTT, P.STUCKEY
ROC, DISCO, CSIRO, Univ of Melbourne
Rapport LAAS N°18153, Juin 2018, 17p.
Lien : https://hal.archives-ouvertes.fr/hal-01814083
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The GEO-SAFE project gathers researchers and fire emergency practitioners from EU and Australia with the aim to design innovative models and efficient response tools based on optimization methods for fighting wildfires. In this paper, we consider an evacuation planning problem issued from discussions with practitioners, where a wildfire is threatening a region with intermediate populated centres. As in earlier approaches in case of flood, we use a constraint optimization model involving malleable tasks to represent the evacuation of a population and a cumulative constraint per route segments. Indeed, in order to mitigate congestion risks, the authorities may delay the start of the evacuation but they may also affect the rate of evacuation by modulating the method used to raise the alarm. However, we consider a different objective: we maximize the minimum " safety margin " , weighted by the population, over every road segment. We introduce a new heuristic and a global flow constraint propa-gator. Moreover, we also propose an instance generator based on a random generation of road networks and basic fire propagation models. This generator produces challenging benchmarks even with very few evacuation tasks. Finally, we report the results of extensive computational experiments done using CP Optimizer.
Static state and output feedback synthesis for time-delay systems
M.BARREAU, F.GOUAISBAUT, A.SEURET
MAC
Manifestation avec acte : European Control Conference ( ECC ) 2018 du 12 juin au 15 juin 2018, Limassol (Chypre), Juin 2018, 7p. , N° 17428
Lien : https://hal.laas.fr/hal-01639829
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In this paper, the design of a static feedback gain for a linear system subject to an input delay is studied. This synthesis is based on a stability analysis conducted using Lyapunov-Krasovskii theorem and Bessel-Legendre inequalities expressed in terms of LMIs. Some bilinear non-convex matrix inequalities are obtained to go from analysis to synthesis. They are then difficult to solve and an iterative LMI procedure is given which takes advantage of the elimination lemma. Naturally, slack variables are introduced and then, following an optimization process, values for them are proposed to reduce the conservatism. The two main corollaries discuss the static state and output feedback synthesis. Finally, a comparison is proposed and shows that this formulation introduces small conservatism.
Positive Functionals and Hessenberg Matrices
J.B.LASSERRE, M.PUTINAR
MAC, Nanyang
Rapport LAAS N°18146, Juin 2018, 14p.
Lien : https://hal.archives-ouvertes.fr/hal-01806491
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Not every positive functional defined on bi-variate polynomials of a prescribed degree bound is represented by the integration against a positive measure. We isolate a couple of conditions filling this gap, either by restricting the class of polynomials to harmonic ones, or imposing the vanishing of a defect indicator. Both criteria offer constructive cubature formulas and they are obtained via well known matrix analysis techniques involving either the dilation of a contractive matrix to a unitary one or the specific structure of the Hessenberg matrix associated to the multiplier by the underlying complex variable.