The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
In this paper the Switched Linear Internal Model (SLIM) controller, an Internal Model based control scheme recently proposed by the authors, is qualitatively analyzed in terms of sensitivity to external disturbances. This investigation is particularly relevant to motivate further efforts toward a theoretical assessment of the considered scheme. In fact, SLIM solution is expected to have good robustness...
In this paper, synchronization in coupled irregularly arrays of 3D cellular neural networks (CNNs) is numerically studied. Chaotic synchronization of 3D CNNs is achieved by appealing to complex systems theory. In particular, we consider complex dynamical networks composed by 3D CNNs, as interconnected nodes, where the interactions in the networks are defined by coupling the first state of each node...
This contribution deals with design of controllers for integrating processes with time delay. In contrast to many other methods, the proposed method is not based on the time delay approximation. A control structure combining standard 1DOF and 2DOF control structures is considered. The control design is performed in the RMS ring of retarded quasipolynomial (RQ) meromorphic functions - an algebraic...
In this article, we propose the use of a Sigma - Delta modulation approach combined with an appropriate dualization of generalized proportional integral (GPI) control strategies for the design of observers undergoing switched output injections, as in remote state estimation cases. The class of switched injection sliding observers inherit their robustness with respect to un-modeled perturbation inputs...
The roots of palindromic and antipalindromic polynomials appear in pairs (lambda,1/lambda). A polynomial with such roots is antipalindromic if and only if in addition, it has a root at 1 of an odd multiplicity. The result has applications in system theory: 1) any kernel representation of a discrete-time, time-reversible, scalar, autonomous LTI system is either palindromic or antipalindromic. (Similar...
This paper recapitulates the adaptive (time- varying) control strategy funnel-control (FC) and introduces its direct derivative error reference control (ERC) with specially designed Funnel boundaries and auxiliary reference. Both controller designs are comparatively applied to a nonlinear two-mass flexible servo system for speed control. ERC (as derivative of FC) is based on the high-gain controllability...
This paper deals with discrete-time systems and considers the problem of computing an upper bound to the dwell time of switched systems ensuring a pre-specified root mean square gain (RMS). As a natural consequence of treating general systems of this particular class in terms of the order and the number of subsystems, only sufficient conditions are worked out. However, as positive features, they are...
This paper presents a new approach for on-line identification of an exact affine model for single-input, single- output (SISO) processes with nonlinear and time-varying behaviors. For this purpose, a modified growing and pruning algorithm for radial basis function (MGAP-RBF) neural network is used for affine modeling of the SISO nonlinear and time-varying processes. The extended Kalman filter (EKF)...
A new approach for the design of robust static output feedback controller for a class of discrete-time Lipschitz nonlinear systems with time-varying uncertainties is proposed based on linear matrix inequalities. The controller has also a guaranteed disturbance attenuation level (Hinfin performance). Thanks to the linearity of the proposed LMIs in both the admissible Lipschitz constant of the system...
The paper presents a new discrete time sliding mode flow control algorithm for connection-oriented communication networks. The networks are modeled as discrete time systems with the available bandwidth acting as disturbance. The algorithm employs a time-varying sliding plane, which helps reduce the initial flow rate magnitude. The plane parameters are determined so that the closed-loop system stability...
An adaptive (time-varying) MIMO/SISO control strategy - funnel-control - for position control of nonlinear, coupled (rigid) robotic systems is presented and its applicability in robotics introductory shown. The concept is based on the high-gain controllability of minimum-phase systems with relative degree one and known high-frequency gain. The approach allows prescribed transient behavior without...
The paper proposes a method for feedback stability evaluation for discrete-time, linear time-varying control systems. It is assumed that the time-varying system can be described by linear matrices operators, equivalent to general discrete-time, time-varying state space model with nonzero input-output delay. The main used tools are Bode diagrams approximated for time-varying systems, using power spectral...
This paper deals with the observer design for nonlinear time delay systems. The approach is to represent the observer error system as the feedback interconnection of a linear system and a time varying nonlinearity. The proposed result developed for designing the observer is in term of linear matrix inequalities (LMI) that guarantees the global uniform asymptotic stability of the error dynamic system...
The Archimedes wave swing (AWS) is a a fully- submerged wave energy converter (WEC), that is to say, a device that converts the kinetic energy of sea waves into electricity. A first prototype of the AWS has already been built and tested. This paper presents simulation results of the performance of several control strategies applied to this device, including PID control, reactive control, phase and...
The problem of stabilizing positive switching discrete-time systems by output feedback is studied and solved in this paper. First, necessary and sufficient conditions for the existence of such controllers are presented for non-switching positive systems, which are then extended to positive switching systems. The proposed conditions, formulated as LMIs, can be directly used for controller synthesis...
An adaptive output feedback neural network controller is designed, capable of rendering affine in the control uncertain MIMO nonlinear systems passive. Consequently, a linear output feedback is employed to stabilize the system. The controlled system need not be in normal form, or have a well defined relative degree. Under a zero state detectability assumption, uniform ultimate boundedness of the system's...
This paper provides some qualitative results concerning the asymptotic stability of some dynamical systems encountered in biochemical networks. We adopt a frequency-domain approach combined with a simple geometric interpretation and we give a complete characterization of the dynamical behavior of the linearized system under consideration. The conclusion of the analysis can be resumed as follows: the...
The main goal of this paper consists in the development of a new actuator fault-tolerant control dedicated to nonlinear systems. Based on the assumption that the nonlinear system is described by a finite number of interpolated linear time invariant models, the proposed method makes possible the faults compensation for the whole operating range through an extended interacting multiple model. Its principle...
The problem of asymptotic state reconstruction of systems characterized by nonlinear state-output maps is investigated in this paper. The approach here presented is based on the approximation of output maps by means of polynomials or by ratios of polynomials, also named rational functions (RF). In previous papers the authors showed that when the input-state dynamics is bilinear and the output maps...
Based on the Euler angles parameterization, a new approach for the attitude control of a vertical take-off and landing (VTOL) quadrotor aircraft is proposed. It rests on the combination of the backstepping technique and a nonlinear robust PI controller. The integral action gain is nonlinear and based on a switching function that ensures a robust behaviour for the overall control law. One of the strengths...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.