18221

19/12/2018

M.BARREAU, F.GOUAISBAUT, A.SEURET

MAC

Manifestation avec acte : IEEE Conference on Decision and Control ( CDC ) 2018 du 17 décembre au 19 décembre 2018, Miami Beach (USA), Décembre 2018, 7p. , N° 18221

Lien : https://hal.laas.fr/hal-01845845

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This paper deals with the stabilization of an anti-stable string equation with Dirichlet actuation where the instability appears because of the uncontrolled boundary condition. Then, infinitely many unstable poles are generated and an infinite dimensional control law is therefore proposed to exponentially stabilize the system. The idea behind the choice of the controller is to extend the domain of the PDE so that the anti-damping term is compensated by a damping at the other boundary condition. Additionally, notice that the system can then be exponentially stabilized with a chosen decay-rate and is robust to uncertainties on the wave speed and the anti-damped coefficient of the wave equation, with the only use of a point-wise boundary measurement. The efficiency of this new control strategy is then compared to the backstepping approach.

18061

19/12/2018

M.BARREAU, A.SEURET, F.GOUAISBAUT

MAC

Manifestation avec acte : IEEE Conference on Decision and Control ( CDC ) 2018 du 17 décembre au 19 décembre 2018, Miami Beach (USA), Décembre 2018, 6p. , N° 18061

Lien : https://hal.laas.fr/hal-01725416

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This article deals with the stability analysis of a drilling system which is modelled as a coupled ordinary differential equation / string equation. The string is damped at the two boundaries but leading to a stable open-loop system. The aim is to derive a linear matrix inequality ensuring the exponential stability with a guaranteed decay-rate of this interconnected system. A strictly proper dynamic controller based on boundary measurements is proposed to accelerate the system dynamics and its effects are investigated through the stability theorem and simulations. It results in an efficient finite dimension controller which subsequently improves the system performances.

18214

05/10/2018

R.SERRA , D.ARZELIER, F.BREHARD, M.M.JOLDES

MAC, ROC

Manifestation avec acte : International Astronautical Congress ( IAC ) 2018 du 01 octobre au 05 octobre 2018, Breme (Allemagne), Octobre 2018, 9p. , N° 18214

Lien : https://hal.archives-ouvertes.fr/hal-01830253

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The problem of fixed-time fuel-optimal trajectories with high-thrust propulsion in the vicinity of a Lagrange point is tackled via the linear version of the primer vector theory. More precisely, the proximity to a Lagrange point i.e. any equilibrium point-stable or not-in the circular restricted three-body problem allows for a linearization of the dynamics. Furthermore, it is assumed that the spacecraft has ungimbaled thrusters, leading to a formulation of the cost function with the 1-norm for space coordinates, even though a generalization exists for steerable thrust and the 2-norm. In this context, the primer vector theory gives necessary and sufficient optimality conditions for admissible solutions to two-value boundary problems. Similarly to the case of rendezvous in the restricted two-body problem, the in-plane and out-of-plane trajectories being uncoupled, they can be treated independently. As a matter of fact, the out-of-plane dynamics is simple enough for the optimal control problem to be solved analytically via this indirect approach. As for the in-plane dynamics, the primer vector solution of the so-called primal problem is derived by solving a hierarchy of linear programs, as proposed recently for the aforementioned rendezvous. The optimal thrusting strategy is then numerically obtained from the necessary and sufficient conditions. Finally, in-plane and out-of-plane control laws are combined to form the complete 3-D fuel-optimal solution. Results are compared to the direct approach that consists in working on a discrete set of times in order to perform optimization in finite dimension. Examples are provided near various Lagrange points in the Sun-Earth and Earth-Moon systems, hinting at the extensive span of possible applications of this technique in station-keeping as well as mission analysis, for instance when connecting manifolds to achieve escape or capture.

18163

01/09/2018

M.GONDRAN, M.J.HUGUET, P.LACOMME, A.QUILLIOT, N.TCHERNEV

LIMOS, ROC

Revue Scientifique : Engineering Applications of Artificial Intelligence, Vol.74, pp.70-89, Septembre 2018 , N° 18163

Lien : https://hal.laas.fr/hal-01822071

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The Job-Shop scheduling Problem with Transport (JSPT) is a combinatorial optimization problem that combines both scheduling and routing problems. It has received attention for decades, resulting in numerous publications focused on the makespan minimization. The JSPT is commonly modeled by a disjunctive graph that encompasses both machine-operations and transport-operations. The transport-operations define a sub-problem which is close to the DARP where pickup and delivery operations have to be scheduled. The vast majority of the evaluation functions used into disjunctive graphs of JSPT, minimizes the makespan and there is no routing criteria in the objective function. Commonly used evaluation functions lead to left-shifted solutions for both machine-operations and transport-operations. The present work investigates a new evaluation function for the JSPT which integrates routing problematic to compute non semi-active solutions but which minimize the makespan first and maximize the Quality of Service second thanks to a time-lag max based modeling and an iterative process. The Quality of Service proposed in this paper, is extended from the Quality of Service defined by (Cordeau and Laporte, 2003) for the DARP. The procedure performance is benchmarked with a CPLEX resolution and the numerical experiments proved that the proposed evaluation function is nearly optimal and provides new solutions with a high Quality of Service.

18164

31/08/2018

A.SAHUGUEDE, E.LE CORRONC, M.V.LE LANN

DISCO

Manifestation avec acte : IFAC International Symposium on Fault Detection Supervision and Safety of Technical Processes ( SAFEPROCESS ) 2018 du 29 août au 31 août 2018, Varsovie (Pologne), Août 2018, 8p. , N° 18164

Lien : https://hal.laas.fr/hal-01817529

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Chronicles are temporal patterns well suited for an abstract representation of the behavior of dynamic systems. For fault diagnosis, chronicles describe the nominal and faulty behaviors of the process. Powerful algorithms allow the recognition of chronicles in the flow of observations of the system and appropriate actions can be taken when a faulty situation is recognized. However, designing chronicles is not a trivial thing to do. The increasing complexity and capacity of data generation of highly-advanced processes cause the acquisition of a complete model difficult. This paper focuses on the problem of discovering chronicles that are representative of a system behavior from direct observations. A clustering approach to this problem is considered. The chronicle discovery algorithm proposed here designs chronicles with minimal knowledge of the system to diagnose. Furthermore, unprocessed data obtained directly from the system can be used in this clustering algorithm. Finally, the chronicle discovery algorithm proposed in this paper is illustrated on a sport performance monitoring device for a diagnosis of movement deviations in the temporal domain, in the event domain, or both, considered as faults for the athlete.

18191

24/08/2018

A.SAHUGUEDE, S.FERGANI, E.LE CORRONC, M.V.LE LANN

DISCO

Manifestation avec acte : IEEE International Conference on Automation Science and Engineering ( CASE ) 2018 du 20 août au 24 août 2018, Munich (Allemagne), Août 2018, 6p. , N° 18191

Lien : https://hal.laas.fr/hal-01817539

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This paper is concerned with an innovative strategy that maps chronicles, that are timed discrete event models, to a k-dimensional Euclidean space via random projections. The proposed approach is a projection that takes into account both characteristics of events, namely event types, and temporal constraints of chronicles. This will lead to an unbounded convex polytope in the Euclidean space that contains all the possible instances of the corresponding chronicle. It allows to easily and efficiently compare chronicles. Such comparisons are useful in a fault diagnosis purpose to discriminate chronicles representing behaviors of dynamic processes. Examples and preliminary results are provided in this paper to introduce the proposed methodology.

18222

17/08/2018

M.KORDA, D.HENRION, I.MEZIC

University of Califo, MAC

Rapport LAAS N°18222, Août 2018, 21p.

Lien : https://hal.archives-ouvertes.fr/hal-01841989

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We propose a convex-optimization-based framework for computation of invariant measures of polynomial dynamical systems and Markov processes, in discrete and continuous time. The set of all invariant measures is characterized as the feasible set of an infinite-dimensional linear program (LP). The objective functional of this LP is then used to single-out a specific measure (or a class of measures) extremal with respect to the selected functional such as physical measures, ergodic measures, atomic measures (corresponding to, e.g., periodic orbits) or measures absolutely continuous w.r.t. to a given measure. The infinite-dimensional LP is then approximated using a standard hierarchy of finite-dimensional semidefinite programming problems (SDPs), the solutions of which are truncated moment sequences, which are then used to reconstruct the measure. In particular, we show how to approximate the support of the measure as well as how to construct a sequence of weakly converging absolutely continuous approximations. The presented framework, where a convex functional is minimized or maximized among all invariant measures, can be seen as a generalization of and a computational method to carry out the so called ergodic optimization, where linear functionals are optimized over the set of invariant measures. Finally, we also describe how the presented framework can be adapted to compute eigenmeasures of the Perron-Frobenius operator.

18219

16/08/2018

E.PAUWELS, M.PUTINAR, J.B.LASSERRE

MAC, Nanyang

Rapport LAAS N°18219, Août 2018, 20p.

Lien : https://hal.archives-ouvertes.fr/hal-01845137

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Spectral features of the empirical moment matrix constitute a resourceful tool for unveiling properties of a cloud of points, among which, density, support and latent structures. It is already well known that the empirical moment matrix encodes a great deal of subtle attributes of the underlying measure. Starting from this object as base of observations we combine ideas from statistics, real algebraic geometry, orthogonal poly-nomials and approximation theory for opening new insights relevant for Machine Learning (ML) problems with data supported on singular sets. Refined concepts and results from real algebraic geometry and approximation theory are empowering a simple tool (the empirical moment matrix) for the task of solving non-trivial questions in data analysis. We provide (1) theoretical validation , (2) numerical experiments and, (3) connections to real world data as a validation of the stamina of the empirical moment matrix approach.

18218

16/08/2018

D.HENRION, M.KRUZIK, T.WEISSER

MAC, CzechTech. Univ.

Rapport LAAS N°18218, Août 2018, 15p.

Lien : https://hal.archives-ouvertes.fr/hal-01802883

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Optimal control problems with oscillations (chattering controls) and concentrations (impulsive controls) can have integral performance criteria such that concentration of the control signal occurs at a discontinuity of the state signal. Techniques from functional analysis (anisotropic parametrized measures) are applied to give a precise meaning of the integral cost and to allow for the sound application of numerical methods. We show how this can be combined with the Lasserre hierarchy of semidefinite programming relaxations

18133

01/08/2018

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).

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