Emergency control of unstable behavior of nonlinear systems induced by fault.
Equivalência de sistemas de gradiente
Estimation of the output deviation norm for uncertain, discrete-time nonlinear systems in a state dependent form
Numerical evaluation of the optimal nonlinear robust control requires estimating the impact of parameter uncertainties on the system output. The main goal of the paper is to propose a method for estimating the norm of an output trajectory deviation from the nominal trajectory for nonlinear uncertain, discrete-time systems. The measure of the deviation allows us to evaluate the robustness of any designed controller. The first part of the paper concerns uncertainty modelling for nonlinear systems...
Exact controllability of the radial solutions of the semilinear wave equation in R3.
The exact internal controllability of the radial solutions of a semilinear heat equation in R3 is proved. The result applies for nonlinearities that are of an order smaller than |s| logp |s| at infinity for 1 ≤ p < 2. The method of the proof combines HUM and a fixed point technique.
Existence of different kind of solutions for discrete time equations
The aim of this paper is to extend the classical linear condition concerning diagonal dominant bloc matrix to fully nonlinear equations. Even if assumptions are strong, we obtain an explicit condition which exactly extend the one known in linear case, and the setting allows also to consider bicontinuous operator instead of the schift and as particular case, we receive periodic or almost periodic solutions for discrete time equations.
Existence of optimal controls for control systems governed by nonlinear partial differential equations
Exponential stability for nonlinear filtering
Exponential stability of time-switched two-subsystem nonlinear systems with application to intermittent control.
Exponential stabilization of nonlinear driftless systems with robustness to unmodeled dynamics
Exponential stabilization of nonlinear driftless systems with robustness to unmodeled dynamics
Exponential stabilization of nonlinear driftless affine control systems is addressed with the concern of achieving robustness with respect to imperfect knowledge of the system's control vector fields. In order to satisfy this robustness requirement, and inspired by Bennani and Rouchon [1] where the same issue was first addressed, we consider a control strategy which consists in applying periodically updated open-loop controls that are continuous with respect to state initial conditions. These...
Exponentially dissipative nonlinear dynamical systems: A nonlinear extension of strict positive realness.
Fault estimation for time-varying systems with Round-Robin protocol
This paper is concerned with the design problem of finite-horizon fault estimator for a class of nonlinear time-varying systems with Round-Robin protocol scheduling. The faults are assumed to occur in a random way governed by a Bernoulli distributed white sequence. The communication between the sensor nodes and fault estimators is implemented via a shared network. In order to prevent the data from collisions, a Round-Robin protocol is utilized to orchestrate the transmission of sensor nodes. By...
Fault tolerant control of switched nonlinear systems with time delay under asynchronous switching
This paper investigates the problem of fault tolerant control of a class of uncertain switched nonlinear systems with time delay under asynchronous switching. The systems under consideration suffer from delayed switchings of the controller. First, a fault tolerant controller is proposed to guarantee exponentially stability of the switched systems with time delay. The dwell time approach is utilized for stability analysis and controller design. Then the proposed approach is extended to take into...
Feedback linearization idle-speed control: design and experiments
This paper proposes a novel nonlinear control algorithm for idle-speed control of a gasoline engine. This controller is based on the feedback linearization approach and extends this technique to the special structure and specifications of the idle-speed problem. Special static precompensations and cascaded loops are used to achieve the desired bandwidth separation between the fast spark and slow air-bypass action. A key element is the inclusion of the (engine-speed dependent) induction to power...
Feedback linearization of control for nonlinear systems with uncertainties
Field-weakening nonlinear control of a separately excited DC motor.
Finite element-based observer design for nonlinear systems with delayed measurements
This paper presents a computational procedure for the design of an observer of a nonlinear system. Outputs can be delayed, however, this delay must be known and constant. The characteristic feature of the design procedure is computation of a solution of a partial differential equation. This equation is solved using the finite element method. Conditions under which existence of a solution is guaranteed are derived. These are formulated by means of theory of partial differential equations in -space....
Finite-time boundedness and stabilization of switched linear systems
In this paper, finite-time boundedness and stabilization problems for a class of switched linear systems with time-varying exogenous disturbances are studied. Firstly, the concepts of finite-time stability and finite-time boundedness are extended to switched linear systems. Then, based on matrix inequalities, some sufficient conditions under which the switched linear systems are finite-time bounded and uniformly finite-time bounded are given. Moreover, to solve the finite-time stabilization problem,...
Finite-time cooperative tracking control for a class of second-order nonlinear multi-agent systems
The problem of finite-time cooperative tracking control for a class of second-order nonlinear multi-agent systems is studied in this paper. The agent dynamic is described by a second-order nonlinear system with uncertain time-varying control coefficients and unknown nonlinear perturbations. Based on the finite-time control technique and graph theory, a class of distributed finite-time control laws are proposed which are only based on the neighbors' information. Under the proposed controller, it...
Flat outputs of two-input driftless control systems
We study the problem of flatness of two-input driftless control systems. Although a characterization of flat systems of that class is known, the problems of describing all flat outputs and of calculating them is open and we solve it in the paper. We show that all x-flat outputs are parameterized by an arbitrary function of three canonically defined variables. We also construct a system of 1st order PDE’s whose solutions give all x-flat outputs of two-input driftless systems. We illustrate our results...