Browsing by Subject "Nonlinear control systems"

Now showing 1 - 9 of 9

Open Access
Model based anticontrol of chaos
(IEEE, 2003) Morgül, Ömer
We will consider model based anticontrol of chaotic systems. We consider both continuous and discrete time cases. We first assume that the systems to be controlled are linear and time invariant. Under controllability assumption, we transform these systems into some canonical forms. We assume the existence of chaotic systems which has similar forms. Then by using appropriate inputs, we match the dynamics of the systems to be controlled and the model chaotic systems.
Open Access
A model-based scheme for anticontrol of some chaotic systems
(World Scientific Publishing, 2003) Morgül, Ö.
We consider a model-based approach for the anticontrol of some continuous time systems. We assume the existence of a chaotic model in an appropriate form. By using a suitable input, we match the dynamics of the controlled system and the chaotic model. We show that controllable systems can be chaotifled with the proposed method. We give a procedure to generate such chaotic models. We also apply an observer-based synchronization scheme to compute the required input.
Open Access
Multi-stage neural networks with application to motion planning of a mechanical snake
(IEEE, 2003-06) Fidan, B.; Sezer, Erol; Akar, M.
An efficient approach to nonlinear control problems in which the plant is to be driven to a desired state using a neural network controller in a number of steps is by representing the whole process as a multi - stage neural network. In this paper, an explicit formulation of the back propagation algorithm is developed for such networks. Later, this approach is used to build up a path planner for a mechanical snake (a robot composed of a sequence of articulated links). This path planner, together with a tracking algorithm, is shown to get the mechanical snake out of a collision-free closed region.
Open Access
Nonlinear PDE control of two-link flexible arm with nonuniform cross section
(IEEE, 2006-06) Dog̃an, M.; Morgül, Ömer
A two-link flexible arm with nonuniform or variable cross-section by design will be considered based on an exact PDE model with boundary conditions. In this research, the nonlinear controller is used to achieve set-point regulation of the rigid modes as well as suppression of elastic vibrations. The control laws are obtained by energy based Lyapunov approach. © 2006 IEEE.
Open Access
On the boundary control of Kirchhoff's nonlinear string
(IFAC, 2007) Morgül, Ömer; Shahruz, S. M.
In this paper we propose two new classes of controllers which stabilize Kirchhoff's nonlinear string by using boundary control techniques. We assume that the boundary displacement is the only available measurement. The classes of controllers proposed in this paper are related to the positive real controllers. One of the classes generalizes a special class of such stabilizing controllers which is already proposed in the literature and the other one is new.
Open Access
On the control of chaotic systems in Lur'e form by using dither
(Institute of Electrical and Electronics Engineers, 1999-10) Morgül, Ö.
In this paper we propose the application of dither for controlling chaotic systems in the Lur'e form. Dither is a high-frequency periodic signal and has the effect of modifying the nonlinearity for some nonlinear systems. We use piecewise constant dither signals and propose three different methods for the selection of dither parameters. We also present some experimental results.
Open Access
On the design of AQM supporting TCP flows using robust control theory
(IEEE, 2004) Quet, P-F.; Özbay, Hitay
Recently it has been shown that the active queue management schemes implemented in the routers of communication networks supporting transmission control protocol (TCP) flows can be modeled as a feedback control system. Based on a delay differential equations model of TCPs congestion-avoidance mode different control schemes have been proposed. Here a robust controller is designed based on the known techniques for H∞ control of systems with time delays.
Open Access
Optimal control for a class of partially observed bilinear stochastic systems
(IEEE, 1990) Dabbous, Tayel E.
An alternative formulation is presented for a class of partially observed bilinear stochastic control problems which is described by three sets of stochastic differential equations: one for the system to be controlled, one for the observer, and one for the control process which is driven by the observation process. With this formulation, the stochastic control problem is converted to an equivalent deterministic identification problem of control gain matrices. Using standard variation arguments, the necessary conditions of optimality on the basis of which the optimal control parameters can be determined are obtained.
Open Access
State feedback stabilization of switched systems with delay: trajectory based approach
(IEEE, 2017) Mazenc, F.; Ahmed, Saeed; Özbay, Hitay
We present a new trajectory based approach for state feedback stabilization of switched linear continuous-time systems with a time-varying input delay. In contrast with finding classical common Lyapunov function or multiple Lyapunov functions for establishing the stability of the closed-loop switched system, the new trajectory based approach relies on verifying certain inequalities along the solution of a supplementary system. This study does not make any assumption regarding the stabilizability of all of the constituent subsystems of the switched system. Moreover, no assumption is needed about the differentiability of the delay and no constraint is imposed on the upper bound of the delay derivative. Finally, an illustrative example is included to illustrate the applicability of our results.