Class Of Uncertain Interconnected Systems Research Articles

Decentralized Backstepping Control for Interconnected Systems With Non-Triangular Structural Uncertainties

In this article, a decentralized adaptive control scheme is proposed based on backstepping techniques for a class of uncertain interconnected systems with unknown modeling errors and interactions. Unlike existing results, the functions bounding modeling errors and interactions are not required to meet the triangular condition. Namely, such functions are allowed to depend on all the states of the interconnected system. It is shown that the proposed adaptive control scheme can ensure all signals in the closed-loop system bounded. Simulation studies verify the effectiveness of the proposed scheme.

Adaptive Decentralized Output-Feedback Control Dealing With Static/Dynamic Interactions and Different-Unknown Subsystem Control Directions

In this article, we present an adaptive decentralized control scheme for a class of interconnected uncertain systems with subsystems having different yet unknown control directions and involving static nonlinear interactions as well as input and output dynamic interactions. A new form of K-filters is designed for each subsystem, and only local information is employed to generate control signals. A new Nussbaum-type function is developed with a key property that allows for the quantification of the interconnections among multiple Nussbaum-type functions for the subsystems with different control directions in a single inequality. By using appropriately chosen Lyapunov functions, global stability of the resulting closed-loop system is rigorously established. Simulation results are included to demonstrate the effectiveness of the proposed methodology.

Observer-Based Decentralized Control for Uncertain Interconnected Systems of Neutral Type

The observer-based decentralized control problem is investigated for a class of uncertain interconnected systems of neutral type. Using the singular value decomposition approach, a full-order observer is designed to guarantee the asymptotic stability of the error dynamic system. A novel mathematical technique is developed to solve this design problem. Sufficient condition for uncertain interconnected systems of neutral type to be asymptotic stable is established based on the singular value decomposition method. Furthermore, the desired gains of observer and controller are obtained by the explicit expressions in terms of some free parameters. Finally, an illustrative example is used to demonstrate the proposed approach, and the corresponding simulation results are given to elucidate the effectiveness.

Reliable H ∞ control of a class of uncertain interconnected systems: an LMI approach

The aim of this work is to study the reliable control design problem for parameter-dependent interconnected systems in the presence of actuator failures. Moreover, the control ensures H ∞ performance in front of L 2 perturbations. A more practical model of actuators or control channel failures than outage is adopted, considering partial achievement. The continuous H∞ control problem is solved via elementary manipulations on linear matrix inequalities and the resulting control systems are robustly stable against plant uncertainties and failures.

Delay-dependent decentralized H∞ filtering for uncertain interconnected systems

This article considers delay dependent decentralized H ∞ filtering for a class of uncertain interconnected systems, where the uncertainties are assumed to be time varying and satisfy the norm-bounded conditions. First, combining the Lyapunov-Krasovskii functional approach and the delay integral inequality of matrices, a suf-ficient condition of the existence of the robust decentralized H ∞ filter is derived, which makes the error systems asymptotically stable and satisfies the H ∞ norm of the transfer function from noise input to error output less than the specified up-bound on the basis of the form of uncertainties. Then, the above sufficient condition is transformed to a system of easily solvable LMIs via a series of equivalent transformation. Finally, the numerical simulation shows the efficiency of the main results.

Decentralized H∞ state feedback control for large-scale interconnected uncertain systems with multiple delays

Decentralized H∞ control was studied for a class of interconnected uncertain systems with multiple delays in the state and control and time varying but norm-bounded parametric uncertainties. A sufficient condition which makes the closed-loop system decentralized asymptotically stable with H∞ performance was derived based on Lyapunov stability theorem. This condition is expressed as the solvability problem of linear matrix inequalities. The method overcomes the limitations of the existing algebraic Riccati equation method. Finally, a numerical example was given to demonstrate the design procedure for the decentralized H∞ state feedback controller.

Decentralized impulsive control for a class of uncertain interconnected systems

Decentralized impulsive control for a class of uncertain interconnected systems

Decentralized impulsive control for a class of uncertain interconnected systems

Decentralized impulsive control for a class of uncertain interconnected systems

Decentralized robust control for a class of uncertain interconnected systems

Abstract In this paper, the problem of decentralized control for a class of uncertain linear interconnected systems is considered. The uncertainties of each decomposed system, which do not satisfy matching conditions, are assumed to be structured and value bounded. A robust decentralized scheme is proposed which guarantees the overall uncertain system to be quadratic stable.

Robust Design of Stabilizing Controllers for Interconnected Time-delay Systems

This paper develops a linear decentralized controller that guarantees the exponential stabilization of a class of interconnected uncertain systems with delays. The uncertainties are mismatched and are composed of three portions: local (within each subsystem), interaction (across the subsystem couplings) and state delay. The stability analysis is based on the constructive use of Lyapunov functional. It has been established that the developed stabilizing controller renders the closed-loop interconnected system globally exponentially stable to a calculable zone around the origin.

H∞control of interconnected nonlinear sampled-data systems with parametric uncertainty

This paper studies the problem of robust control design for a class of interconnected uncertain systems under sampled measurements. The class of system under consideration is described by a state space model containing unknown cone bounded nonlinear interaction and time-varying norm-bounded parameter uncertainties in both state and output equations. Our attention is focused on the design of linear dynamic output feedback controllers using sampled measurements. We address the problem of robust H∞ control in which both robust stability and a prescribed H∞ performance are required to be achieved irrespective of the uncertainties and nonlinearities. The H∞ performance measure involves both continuous-time and discrete-time signals. It has been shown that the above problems can be recast into H∞ syntheses for related N decoupled linear sampled-data systems without parameter uncertainties and unknown nonlinearities, which can be solved in terms of Riccati differential equations with finite discrete jumps. A numerical example is given to show the potential of the proposed technique.

Robust Filtering for Interconnected Uncertain Systems Under Sampled Measurements

This paper presents the results of robust filtering for a class of interconnected uncertain systems under sampled measurements. We address the problem of designing filters, using sampled measurements, which would guarantee a prescribed H∞ performance in the continuous-time context, irrespective of the parameter uncertainty and unknown initial states. Both the cases of finite and infinite horizon filtering are investigated in terms of N pairs of Riccati equations with finite discrete jumps.

Robust control design for interconnected uncertain dynamical systems under sampled measurements

This paper presents the results of robust control design for a class of interconnected uncertain systems under sampled measurements. The system under consideration involves parameter uncertainties and unknown nonlinear interactions among subsystems. We address the problem of designing linear dynamic output feedback controllers, using sampled measurements, that stabilize the uncertain system and if required, guarantee a certain performance in an H ∝ sense for all admissible uncertainties. The approach proposed for solving the problems above is to convert them into scale H ∝ control problems for N decoupled linear systems which do not contain parameter uncertainties as well as nonlinear perturbations.

Decentralized stabilization and output tracking of large-scale uncertain systems

A method for the design of linear constant decentralized robust controllers for a class of uncertain interconnected systems is presented in this paper. The uncertainties are assumed to satisfy the general matching conditions for each decomposed subsystem, and both stabilizing control and output tracking control are considered here. In the former, the uncertainties may be time-varying, and the system can be exponentially stabilized. In the latter, with the assumption of time-invariant uncertainties, the system can approach the constant reference input and reject constant disturbances with a prescribed convergence rate.

Decentralized robust controller design for a class of interconnected uncertain systems: with unknown bound of uncertainty

In this paper, a simple decentralized robust control scheme is proposed for a class of interconnected time-varying systems with uncertainties. The uncertainties may appear in the interconnections between the subsystems and also within the subsystems, and they are possibly nonlinear and time-varying. The uncertainties are bounded, but the bounds of the uncertainties are unknown in controller design. When certain matching conditions are satisfied for the uncertain interconnections and the uncertainties within the subsystems, the proposed decentralized control scheme guarantees the controlled system to converge exponentially with a prescribed degree toward the equilibrium of the system, or a residual ball around the equilibrium.

Stabilizing control for a class of uncertain interconnected systems

A linear decentralized control is constructed to stabilize a class of interconnected nonlinear uncertain systems with time-varying state-delay and in which the output measurement is noisy. The control action is based on output-feedback for matched uncertainties and takes the effect of coupling into account. With the knowledge of the uncertainty bounds, it is established that the developed stabilizing controller renders the closed-loop interconnected system globally practically stable. >