This paper presents some analyses about the robust practical stability of a class of nonlinear affine systems in the presence of non-vanishing perturbations based on the passivity concept. The given analyses confirm the robust passivity property of the perturbed nonlinear systems in a certain region. Moreover, robust control laws are designed to guarantee the practical stability of the perturbe...

We consider the problem of stabilizing a nonlinear plant through the use of a, possibly unstable, pre-compensator and a stable feedback-compensator, and parametrizing a class of such stabilizers in terms of a BIBO stable map Q. In the linear case, by means of superposition the pre-and feedback-compensator can be combined in such a way that the BIBO map Q occurs in just one feedback loop within ...

The discrete-time robust repetitive control (RC, or repetitive controller, also designated RC) problem for nonlinear systems is both challenging and practical. This paper proposes a discrete-time output-feedback RC design for a class of systems subject to measurable nonlinearities to track reference robustly with respect to the period variation. The design relies on additive state decomposition...

In the present paper, a new 2-D Van der Polstructural oscillator model is introduced for the vortex induced vibrations of circular cylinders.The main purpose of this task is to control the recently introduced model by means of modern control definitions in state space. In order to control the system, the whole model is linearized about its equilibrium point by deriving state-space matrices. The...

This paper examines the control problem of discrete-time feedback linearizable nonlinear systems for which there is no available analytic models. Based on the ability of fuzzy systems to approximate any nonlinear mapping, the unknown nonlinear system is represented by a Takagi-Sugeno fuzzy model which is identified using input-output data. Then, a fuzzy feedback linearizing controller, based on...

Linear state bisection is introduced as a new method to find time-invariant state feedback control laws for a special form of underactuated nonlinear systems. The specialty of the systems considered is that every unactuated state should be coupled with at least two directly actuated states. The basic idea is based on bisecting actuated states and using linear combinations with adjustable parame...

This study introduces decentralized static output feedback fuzzy control design for nonlinear interconnected systems via T-S fuzzy models. In general, due to the interactions among subsystems, it is dif cult to design an decentralized output feedback controller for nonlinear interconnected systems. A singular value decomposition (SVD) method is proposed in this study to solve the decentralized ...

In recent years, nonlinear model predictive control schemes have been derived that guarantee stability of the closed loop under the assumption of full state information. However, only limited advances have been made with respect to output feedback in connection to nonlinear predictive control. Most of the existing approaches for output feedback nonlinear model predictive control do only guarant...

In this paper, nonlinear output feedback control design for linear systems subject to input saturation is addressed. Main issues of this paper are 1. stability analysis of the feedback system for both of state and output feedback and 2. design of stabilizing nonlinear feedback law. Sufficient global stability conditions for both of state and output feedback are derived. Furthermore, a design ap...

In this paper, an automatic gain control scheme is first proposed for analyses and designs of unity feedback control systems. The controlled system is a nonlinear feedback control system. The overall system is equivalent to a conventional automatic gain control loop with command tracking error input. Therefore, it gives good command tracking behaviour while keeping robust characteristic of the ...