Reduced-order Observer-based Output Feedback Research Articles

Reduced-order observer based output feedback control for a Timoshenko beam

This paper proposes observer based controls for a MIMO Timoshenko beam system with disturbances and references from an exosystem, and by further limiting the references and disturbances, also gives reduced-order controls. At first, we propose state feedback controls to guarantee the output regulation problem of a nominal Timoshenko beam system, which is obtained by specially choosing known disturbances and references. This also makes the PDE observer easily designed based on tracking errors only. Then, exosystem observers and their reduced-order forms are proposed in case of different geometric multiplicities and limited conditions of disturbances, references and system uncertainties. This gives observer based robust controls and reduced-order observer based controls. Robust output regulation is proved for the Timoshenko beam under observer based controls. Simulation examples are provided for a Timoshenko beam system with different references and system uncertainties.

Global Regulation of a Chain of Integrators with an Unknown Delay in the Input via Reduced-order Observer Based Output Feedback with a Gain-scaling Factor

Global Regulation of a Chain of Integrators with an Unknown Delay in the Input via Reduced-order Observer Based Output Feedback with a Gain-scaling Factor

Global exponential stabilisation of nonlinear systems by reduced-order observer-based output feedback control via matrix inequality approach

In this paper, we consider the global exponential stabilisation problem by output feedback for a class of nonlinear systems with the extended structure of nonlinearity over the existing control scheme. The new feature is that we present a newly designed reduced-order observer-based output feedback controller with a gain-scaling factor. In our proposed method, we provide more flexibility in the selection of control parameters by utilising a matrix inequality approach under the extended structure of nonlinearity. Using examples, we illustrate the improved results of the proposed control scheme over the existing control scheme.

Consensus of delayed multi‐agent systems by reduced‐order observer‐based truncated predictor feedback protocols

For high-order linear multi-agent systems with large input and communication delays, a predictor feedback approach is established to design reduced-order observer-based output feedback protocols. This approach can compensate arbitrarily large delays but will lead to infinite dimensional protocols. Under the assumption that the open-loop dynamics is at most polynomially unstable, the proposed predictor feedback protocols is truncated by removing the distributed terms, resulting in a finite dimensional reduced-order observer-based output feedback protocols, which will be referred to as truncated predictor feedback (TPF) protocols. Compared with the predictor feedback protocols, the main advantage of the TPF protocols is that it is very easy to implement. Two numerical examples are worked out to demonstrate the effectiveness of the proposed approaches.

Distributed and Truncated Reduced-Order Observer Based Output Feedback Consensus of Multi-Agent Systems

This technical note is concerned with output feedback consensus of both continuous-time and discrete-time multi-agent systems (MASs) characterized by high-order linear systems with directed communication topologies. Distributed reduced-order observer based protocols are established by only using the relative outputs and inputs of neighboring agents. It is shown that consensusability by the proposed output feedback protocols is equivalent to the consensusability by state feedback protocol. Under the condition that the open-loop dynamics of the MASs is not exponentially unstable, a truncated reduced-order observer based protocol utilizing only the relative outputs of neighboring agents is also established. A numerical example is given to illustrate the effectiveness of the proposed approaches.

Reduced-order observer-based output feedback control of nonlinear time-delay systems with prescribed performance

This paper studies the problem of output feedback control for a class of nonlinear time-delay systems with prescribed performance. The system is in the form of triangular structure with unmodelled dynamics. First, we introduce a reduced-order observer to provide the estimate of the unmeasured states. Then, by setting a new condition with the performance function, we design the state transformation with prescribed performance control. By employing backstepping method, we construct the output feedback controller. It is proved that the resulting closed-loop system is asymptotically stable and both transient and steady-state performance of the output are preserved with the changing supply function idea. Finally, a simulation example is conducted to show the effectiveness of the main results.

Output feedback control of nonlinear systems with uncertain ISS/iISS supply rates and noises

This paper considers the problem of global output feedback control for a class of nonlinear systems with inverse dynamics. The main contribution of paper is that: For the inverse dynamics with uncertain ISS/iISS supply rates, and the systems being disturbed by L2 noises, we construct a reduced-order observer-based output feedback controller, which drives the output of system to zero and maintain other closed-loop signals bounded. Finally, a simulation example shows the effectiveness of the control scheme.

Design of output feedback consensus controllers for nonlinear sampled-data multi-agent systems of strict-feedback form

Design of reduced-order observer-based output feedback consensus controllers for nonlinear sampled-data multi-agent systems of strict-feedback form is considered based on nonlinear sampled-data control and consensus control theories. As a practical application of the proposed design method, output feedback consensus control for sampled-data fully actuated ships is also discussed.

Reduced-order observer-based output feedback regulation for a class of nonlinear systems with iISS inverse dynamics

Global asymptotic regulation via output feedback based on a reduced-order observer is considered for a class of nonlinear systems with integral input-to-state stable (iISS) inverse dynamics. The contributions are that: (1) we further consider the conditions on changing supply rates in iISS systems, and discuss the necessity of some conditions by constructing a counter-example; (2) For a more general class of nonlinear systems with iISS inverse dynamics, a reduced-order observer is introduced, and by the combined approach of backstepping and changing iISS supply rates, an output feedback controller is given to drive the output of system to the origin asymptotically and maintain other closed-loop signals bounded.

TAKING ADVANTAGE OF HOMOGENEITY: A UNIFIED FRAMEWORK FOR OUTPUT FEEDBACK CONTROL OF NONLINEAR SYSTEMS

A unified framework is presented for global output feedback stabilization of a family of uncertain systems with low- and high-order nonlinearities. By taking advantage of homogeneity, together with a domination-based observer/controller design, this framework not only incorporates a number of results proposed recently in the literature, but also yields new results for more general classes of non-uniformly observable and non-smoothly stabilizable systems, whose global stabilization problem cannot be addressed by existing output feedback control schemes. The novelty of this paper lies in the development of a reduced order observer-based output feedback design method, making it possible to compensate simultaneously low-order nonlinearities that dominate near the origin, and high-order nonlinearities that dominate far away from the origin.