840documents trouvés
Improved solutions for ill-conditioned problems involved in set-membership estimation for fault detection and isolation
L.RAVANBOD, C.JAUBERTHIE, N.VERDIERE, L.TRAVE-MASSUYES
Université du Havre, DISCO
Revue Scientifique : Journal of process control, Vol.58, pp.139-151, Octobre 2017 , N° 13403
Diffusable
Plus d'informations
Abstract
Set-membership (SM) estimation implies that the computed solution sets are guaranteed to contain all the feasible estimates consistent with the bounds specified in the model. Two issues often involved in the solution of SM estimation problems and their application to engineering case studies are considered in this paper. The first one is the estimation of derivatives from noisy signals, which in a bounded uncertainty framework means obtaining an enclosure by lower and upper bounds. In this paper, we improve existing methods for enclosing derivatives using Higher-Order Sliding Modes (HOSM) differentiators combining filtering. Our approach turns the use of high order derivatives more efficiently especially when the signal to differentiate has slow dynamics. The second issue of interest is solving linear interval equation systems, which is often an ill-conditioned problem. This problem is reformulated as a Constraint Satisfaction Problem and solved by the combination of the constraint propagation Forward Backward algorithm and the SIVIA algorithm. The two proposed methods are tested on illustrative examples. The two methods are then used in a fault detection and isolation algorithm based on SM parameter estimation that is applied to detect abnormal parameter values in a biological case study.
Cumulative scheduling with variable task profiles and concave piecewise linear processing rate functions
M.NATTAF, C.ARTIGUES, P.LOPEZ
ROC
Revue Scientifique : Constraints, Vol.22, N°4, pp.530-547, Octobre 2017 , N° 17213
Lien : https://hal.archives-ouvertes.fr/hal-01546131
Diffusable
Plus d'informations
Abstract
We consider a cumulative scheduling problem where a task duration and resource consumption are not fixed. The consumption profile of the task, which can vary continuously over time, is a decision variable of the problem to be determined and a task is completed as soon as the integration over its time window of a non-decreasing and continuous processing rate function of the consumption profile has reached a predefined amount of energy. The goal is to find a feasible schedule, which is an NP-hard problem. For the case where functions are concave and piecewise linear, we present two propagation algorithms. The first one is the adaptation to concave functions of the variant of the energetic reasoning previously established for linear functions. Furthermore, a full characterization of the relevant intervals for time-window adjustments is provided. The second algorithm combines a flow-based checker with time-bound adjustments derived from the timetable disjunctive reasoning for the cumulative constraint. Complementarity of the algorithms is assessed via their integration in a hybrid branch-and-bound and computational experiments on small-size instances.
Computing Gaussian & exponential measures of semi-algebraic sets
J.B.LASSERRE
MAC
Revue Scientifique : Advances in Applied Mathematics, Vol.91, pp.137-163, Octobre 2017 , N° 15302
Lien : https://hal.archives-ouvertes.fr/hal-01185641
Diffusable
Plus d'informations
Abstract
We provide a numerical scheme to approximate as closely as desired the Gaussian or exponential measure μ(\om) of (not necessarily compact) basic semi-algebraic sets \om⊂\Rn. We obtain two monotone (non increasing and non decreasing) sequences of upper and lower bounds (ω¯¯¯d), (ω−d), d∈\N, each converging to μ(\om) as d→∞. For each d, computing ω¯¯¯d or ω−d reduces to solving a semidefinite program whose size increases with d. Some preliminary (small dimension) computational experiments are encouraging and illustrate the potential of the method. The method also works for any measure whose moments are known and which satisfies Carleman's condition.
Hybrid adaptive control of the boost converter
S.HADJERAS, C.ALBEA SANCHEZ, G.GARCIA
MAC
Rapport LAAS N°17311, Septembre 2017, 6p.
Lien : https://hal.laas.fr/hal-01588081
Diffusable
Plus d'informations
Abstract
This work proposes a control law for the boost converter with unknown constant resistive load. It focuses on Hybrid Dynamical System (HDS) theory, which considers the voltage and current signals as continuous-time variables and the switching signal as discrete-time variable. In several applications the voltage has to be constant. To ensure that the voltage value is robust with respect to any reference, an adaptive scheme is proposed. This adaptation is accomplished using a state observer and assuming that all states are accessible. Then, the full system stability can be established by using a singular perturbation analysis. The hybrid adaptive controller is tested in simulations.
ARMISCOM: self-healing service composition
J.VIZCARRONDO, J.AGUILAR, E.EXPOSITO, A.SUBIAS
CENDITEL, Andes, LIUPPA, DISCO
Revue Scientifique : Service Oriented Computing and Applications, Vol.11, N°3, pp.345-365, Septembre 2017 , N° 17304
Non disponible
Plus d'informations
Abstract
In the domain of the service composition, the failure of a service generates error propagation in the other services, and therefore, it can generate the failure of the entire system. Usually, these failures cannot be detected and corrected only with local information. Normally, it is required the development of architectures that enable the diagnosis and correction of faults, both locally (elementary service) as well as globally (service composition). This paper presents a reflexive middleware architecture based on autonomic computing, which allows the distributed diagnosis of faults in the service composition, called ARMISCOM. This middleware has not a central diagnoser, instead the diagnosis of failures is carried out through the interaction of local diagnosers present in each service of the composition. These local diagnoses use a distributed chronicle approach proposed in previous works, which allows the recognition of fully distributed patterns of the classic failures in the SOA systems. In addition, the repair strategies are defined through consensus of the repairers, equally distributed between the services of the composition. The repair strategies use the concept of “equivalent regions” defined in this paper, for the fault correction in a SOA application.
Sparse polynomial interpolation: compressed sensing, super resolution, or Prony?
C.JOSZ, J.B.LASSERRE, B.MOURRAIN
MAC, INRIA Sophia
Rapport LAAS N°17279, Septembre 2017, 23p.
Lien : https://hal.archives-ouvertes.fr/hal-01575325
Diffusable
Plus d'informations
Abstract
We show that the sparse polynomial interpolation problem reduces to a discrete super-resolution problem on the n-dimensional torus. Therefore the semidefinite programming approach initiated by Candès & Fernandez-Granda [7] in the univariate case (and later extended to the multi-variate setting) can be applied. In particular, exact recovery is guaranteed provided that a geometric spacing condition on the " supports " holds and the number of evaluations are sufficiently many (but not many). It also turns out that the (compressed sensing) LP-formulation of ℓ 1-norm minimization is also guaranteed to provide exact recovery provided that the evaluations are made in a certain manner and even though the Restricted Isometry Property for exact recovery is not satisfied. (A naive compressed sensing LP-approach does not offer such a guarantee.) Finally we also describe the algebraic Prony method for sparse interpolation, which also recovers the exact decomposition but from less point evaluations and with no geometric spacing condition. We provide two sets of numerical experiments , one in which the super-resolution technique and Prony's method seem to cope equally well with noise, and another in which the super-resolution technique seems to cope with noise better than Prony's method, at the cost of an extra computational burden (i.e. a semidefinite optimization).
Randomized and robust methods for uncertain systems using R-RoMulOC, with applications to DEMETER satellite benchmark
M.CHAMANBAZ, F.DABBENE, D.PEAUCELLE, C.PITTET-MECHIN
ARAKUT, CNR-IEIIT, Torino, MAC, CNES
Revue Scientifique : AerospaceLab Journal, N°13, 15p., Septembre 2017 , N° 17263
Lien : https://hal.archives-ouvertes.fr/hal-01570588
Diffusable
Plus d'informations
Abstract
R-RoMulOC is a freely distributed toolbox which aims at making easily available to the users different optimization-based methods for dealing with uncertain systems. It implements both deterministic LMI-based results, that provide guaranteed performances for all values of the uncertainties, and probabilistic randomization-based approaches, that guarantee performances for all values of the uncertainties except for a subset with arbitrary small probability measure. The paper is devoted to the description of these two approaches for analysis and control design when applied to a satellite benchmark proposed by CNES, the French Space Agency. The paper also describes the modeling of the DEMETER satellite and its integration into the R-RoMulOC toolbox as a challenging test example. Design of state-feedback controllers and closed-loop performance analysis are carried out with the randomized and robust methods available in the R-RoMulOC toolbox.
Control of Anesthesia Based on Singularly Perturbed Model
S.TARBOURIECH, I.QUEINNEC, G.GARCIA, M.MAZEROLLES
MAC, CHU Toulouse
Ouvrage (contribution) : Positive Systems - Theory and Applications (POSTA 2016), Springer, N°ISBN 978-3-319-54210-2, Septembre 2017, Chapter 2, pp.17-29 , N° 17273
Lien : https://hal.laas.fr/hal-01573825
Diffusable
Plus d'informations
Abstract
This chapter deals with the control of anesthesia taking into account the pos-itivity together with the upper limitation constraints of the variables and the target interval tolerated for the depth of anesthesia during a surgery. Due to the presence of multiple time scale dynamics in the anesthesia model, the system is re-expressed through a singularly perturbed system allowing to decouple the fast dynamics from the slow ones. Differently from general approaches for singularly perturbed systems , the control objective is then to control and accelerate the fast system without interest in modifying the slow dynamics. Thus, a structured state feedback control is proposed through quasi-LMI (linear matrix inequalities) conditions. The characterization of domains of stability and invariance for the system is provided. Associated convex optimization issues are then discussed. Finally, the theoretical conditions are evaluated on a simulated patient case.
Exact values for three domination-like problems in circular and infinite grid graphs of small height
M.BOUZNIF, J.DARLAY, J.MONCEL, M.PREISSMANN
G-SCOP, Innovation 24 & LocalSolver, ROC
Rapport LAAS N°17267, Septembre 2017, 29p.
Lien : https://hal.archives-ouvertes.fr/hal-01569881
Diffusable
Plus d'informations
Abstract
In this paper we study three domination-like problems, namely identifying codes, locating-dominating codes, and locating-total-dominating codes. We are interested in finding the minimum cardinality of such codes in circular and infinite grid graphs of given height. We provide an alternate proof for already known results, as well as new results. These were obtained by a computer search based on a generic framework, that we developed earlier, for the search of a minimum labeling satisfying a pseudo-d-local property in rotagraphs.
Stability analysis of a system coupled to a heat equation
L.BAUDOUIN, A.SEURET, F.GOUAISBAUT
MAC
Rapport LAAS N°17247, Septembre 2017, 8p.
Lien : https://hal.archives-ouvertes.fr/hal-01566455
Diffusable
Plus d'informations
Abstract
As a first approach to the study of systems coupling finite and infinite dimensional natures, this article addresses the stability of a system of ordinary differential equations coupled with a classic heat equation using a Lyapunov functional technique. Inspired from recent developments in the area of time delay systems, a new methodology to study the stability of such a class of distributed parameter systems is presented here. The idea is to use a polynomial approximation of the infinite dimensional state of the heat equation in order to build an enriched energy functional. A well known efficient integral inequality (Bessel inequality) will allow to obtain stability conditions expressed in terms of linear matrix inequalities. We will eventually test our approach on academic examples in order to illustrate the efficiency of our theoretical results.