Sliding mode control of uncertain neutral stochastic systems with multiple delays.
Sliding mode controller-observer design for multivariable linear systems with unmatched uncertainty
This paper presents sufficient conditions for the sliding mode control of a system with disturbance input. The behaviour of the sliding dynamics in the presence of unmatched uncertainty is also studied. When a certain sufficient condition on the gain feedback matrix of the discontinuous controller and the disturbance bound holds, then the disturbance does not affect the sliding system. The design of asymptotically stable sliding observers for linear multivariable systems is presented. A sliding...
Sliding mode methods for fault detection and fault tolerant control with application to aerospace systems
Sliding mode methods have been historically studied because of their strong robustness properties with regard to a certain class of uncertainty, achieved by employing nonlinear control/injection signals to force the system trajectories to attain in finite time a motion along a surface in the state-space. This paper will consider how these ideas can be exploited for fault detection (specifically fault signal estimation) and subsequently fault tolerant control. It will also describe applications of...
Sliding mode observers and observability singularity in chaotic synchronization.
Sliding subspace design based on linear matrix inequalities
In this work, an alternative for sliding surface design based on linear and bilinear matrix inequalities is proposed. The methodology applies for reduced and integral sliding mode control, both continuous- and discrete-time; it takes advantage of the Finsler's lemma to provide a greater degree of freedom than existing approaches for sliding subspace design. The sliding surfaces thus constructed are systematically found via convex optimization techniques, which are efficiently implemented in commercially...
SMAC-FDI: A single model active fault detection and isolation system for unmanned aircraft
This article presents a single model active fault detection and isolation system (SMAC-FDI) which is designed to efficiently detect and isolate a faulty actuator in a system, such as a small (unmanned) aircraft. This FDI system is based on a single and simple aerodynamic model of an aircraft in order to generate some residuals, as soon as an actuator fault occurs. These residuals are used to trigger an active strategy based on artificial exciting signals that searches within the residuals for the...
Smooth factorizations of matrix valued functions and their derivatives.
Smooth optimal synthesis for infinite horizon variational problems
We study Hamiltonian systems which generate extremal flows of regular variational problems on smooth manifolds and demonstrate that negativity of the generalized curvature of such a system implies the existence of a global smooth optimal synthesis for the infinite horizon problem. We also show that in the Euclidean case negativity of the generalized curvature is a consequence of the convexity of the Lagrangian with respect to the pair of arguments. Finally, we give a generic classification for...
Soft computing in modelbased predictive control footnotemark
The application of fuzzy reasoning techniques and neural network structures to model-based predictive control (MPC) is studied. First, basic structures of MPC algorithms are reviewed. Then, applications of fuzzy systems of the Takagi-Sugeno type in explicit and numerical nonlinear MPC algorithms are presented. Next, many techniques using neural network modeling to improve structural or computational properties of MPC algorithms are presented and discussed, from a neural network model of a process...
Soft variable structure control in time-delay systems with saturating input
In order to achieve a short regulation cycle, time-optimal control has been considered in the past. However, the sensitivity to errors and uncertainties, and implementation difficulties in the practical systems, have incited other research directions to meet this objective. In this paper, soft Variable Structure Control (VSC) is analyzed from the perspective of linear time-delay systems with input constraint. The desired fast convergence under a smoothly varying control signal is obtained. The stability...
Soluble approximation of linear systems in max-plus algebra
We propose an efficient method for finding a Chebyshev-best soluble approximation to an insoluble system of linear equations over max-plus algebra.
Solution and stability of a set of th order linear differential equations with periodic coefficients via Chebyshev polynomials.
Solutions of inverse problems with potential application for breast tumour detection using microwave measurements.
Solutions of time-varying singular nonlinear sytems by single-term Walsh series.
Some algorithmic aspects of subspace identificationwith inputs
It has been experimentally verified that most commonly used subspace methods for identification of linear state-space systems with exogenous inputs may, in certain experimental conditions, run into ill-conditioning and lead to ambiguous results. An analysis of the critical situations has lead us to propose a new algorithmic structure which could be used either to test difficult cases andor to implement a suitable combination of new and old algorithms presented in the literature to help fixing the...
Some controllability results for the 2D Kolmogorov equation
Some controllability results for the relativistic Vlasov-Maxwell system
The goal of this note is to present the recent results concerning the controllability of the Vlasov-Maxwell system, which are proved in the paper [10] by Olivier Glass and the author.
Some decay properties for the damped wave equation on the torus
This article is a proceedings version of the ongoing work [1], and has been the object of a talk of the second author during the Journées “Équations aux Dérivées Partielles” (Biarritz, 2012).We address the decay rates of the energy of the damped wave equation when the damping coefficient does not satisfy the Geometric Control Condition (GCC). First, we give a link with the controllability of the associated Schrödinger equation. We prove that the observability of the Schrödinger group implies that...
Some geometrical properties of infinite-dimensional bilinear controlled systems
The study of controlled infinite-dimensional systems gives rise to many papers (see for instance [GXL], [GXB], [X]) but it is also motivated by various mathematical problems: partial differential equations ([BP]), sub-Riemannian geometry on infinite-dimensional manifolds ([Gr]), deformations in loop-spaces ([AP], [PS]). The first difference between finite and infinite-dimensional cases is that solutions in general do not exist (even locally) for every given control function. The aim of this paper...
Some ideas for comparison of Bellman chains
In this paper we are exploiting some similarities between Markov and Bellman processes and we introduce the main concepts of the paper: comparison of performance measures, and monotonicity of Bellman chains. These concepts are used to establish the main result of this paper dealing with comparison of Bellman chains.