scholarly journals Vibration suppression of a dynamical system to multi-parametric excitations via time-delay absorber

2012 ◽  
Vol 36 (1) ◽  
pp. 35-45 ◽  
Author(s):  
H.A. El-Gohary ◽  
W.A.A. El-Ganaini
Keyword(s):  
Dynamical System ◽  
Time Delay ◽  
Vibration Suppression

scholarly journals A time delay dynamical model for outbreak of 2019-nCoV and the parameter identification

2020 ◽  
Vol 28 (2) ◽  
pp. 243-250 ◽  
Author(s):  
Yu Chen ◽  
Jin Cheng ◽  
Yu Jiang ◽  
Keji Liu
Keyword(s):  
Dynamical System ◽  
Time Delay ◽  
Parameter Identification ◽  
Typical Feature ◽  
The Novel ◽  
Isolation Rate ◽  
High Isolation ◽  
The Government ◽  
System With Time Delay ◽  
Official Data

AbstractIn this paper, we propose a novel dynamical system with time delay to describe the outbreak of 2019-nCoV in China. One typical feature of this epidemic is that it can spread in the latent period, which can therefore be described by time delay process in the differential equations. The accumulated numbers of classified populations are employed as variables, which is consistent with the official data and facilitates the parameter identification. The numerical methods for the prediction of the outbreak of 2019-nCoV and parameter identification are provided, and the numerical results show that the novel dynamic system can well predict the outbreak trend so far. Based on the numerical simulations, we suggest that the transmission of individuals should be greatly controlled with high isolation rate by the government.

TWO-SCROLL ATTRACTOR IN A DELAY DYNAMICAL SYSTEM

2007 ◽  
Vol 17 (10) ◽  
pp. 3455-3460 ◽  
Author(s):  
ARŪNAS TAMAŠEVIČIUS ◽  
TATJANA PYRAGIENĖ ◽  
MANTAS MEŠKAUSKAS
Keyword(s):  
Dynamical System ◽  
Time Delay ◽  
Nonlinear Function ◽  
Delay System ◽  
The Novel ◽  
Type Function ◽  
Delay Dynamical System ◽  
Glass Type ◽  
Electronic Oscillator

Nonvanishing 𐑍-shaped nonlinear function has been introduced in delay dynamical system instead of commonly used Mackey–Glass type function. Depending on time delay the system exhibits not only mono-scroll, but also more complex two-scroll hyperchaotic attractors. Delay system with the novel nonlinear function can be implemented as an analogue electronic oscillator.

Control of multi-scroll attractors in a memristor-coupled resonator via time-delayed feedback

2018 ◽  
Vol 32 (32) ◽  
pp. 1850399 ◽  
Author(s):  
Zhilong Liu ◽  
Fuqiang Wu ◽  
Faris Alzahrani ◽  
Jun Ma
Keyword(s):  
Dynamical System ◽  
Time Delay ◽  
Magnetic Flux ◽  
Memory Effect ◽  
Delayed Feedback ◽  
Feedback Gain ◽  
Initial Setting ◽  
Physical Background ◽  
Time Delayed Feedback ◽  
With Memory

A four-variable dynamical system composed of memristor is proposed to investigate the dependence of multi-scroll attractor on initial setting for one variable with memory, and the description for physical background is supplied. It is found that appropriate setting of initial values for the memory variable can induce different numbers of attractor, as a result, resetting initials can change the profile of attractors which is also dependent on the calculating period. Time-delayed feedback is used to stabilize the dynamical system thus the effect of initial dependence is suppressed and multi-scroll attractors are controlled by applying appropriate time delay and feedback gain in the controller. Furthermore, the system is verified on FPGA circuit platform and memristor is used to describe the memory effect of variable related to magnetic flux. It is confirmed that multi-scroll attractors can be stabilized and the dependence of initials setting is suppressed in experiment way.

Modified Zero Time Delay Input Shaping for Industrial Robot With Flexibility

2017 ◽  
Author(s):  
Yu Zhao ◽  
Masayoshi Tomizuka
Keyword(s):  
Time Delay ◽  
Vibration Suppression ◽  
Industrial Robot ◽  
Experimental Results ◽  
Input Shaping ◽  
Smooth Motion ◽  
Zero Time

Although input shaping is an effective approach for vibration suppression in a variety of applications, the time delay introduced is not desired. Current techniques to reduce the time delay can not guarantee zero delay or may cause non-smooth motion, which is harmful for the actuators. In order to address such issue, a modified zero time delay input shaping is proposed in this paper. Experimental results show the advantage of the proposed approach.

Dynamics of Neural Networks as Nonlinear Systems with Several Equilibria

2011 ◽  
pp. 331-357 ◽  
Author(s):  
Daniela Danciu
Keyword(s):  
Neural Network ◽  
Dynamical System ◽  
Neural Networks ◽  
Time Delay ◽  
Dynamical Systems ◽  
Qualitative Properties ◽  
The Neural Network ◽  
The Neural Networks ◽  
Global Asymptotics ◽  
Dynamical Properties

Neural networks—both natural and artificial, are characterized by two kinds of dynamics. The first one is concerned with what we would call “learning dynamics”. The second one is the intrinsic dynamics of the neural network viewed as a dynamical system after the weights have been established via learning. The chapter deals with the second kind of dynamics. More precisely, since the emergent computational capabilities of a recurrent neural network can be achieved provided it has suitable dynamical properties when viewed as a system with several equilibria, the chapter deals with those qualitative properties connected to the achievement of such dynamical properties as global asymptotics and gradient-like behavior. In the case of the neural networks with delays, these aspects are reformulated in accordance with the state of the art of the theory of time delay dynamical systems.

Active Vibration Suppression With Time Delayed Feedback

2003 ◽  
Vol 125 (3) ◽  
pp. 384-388 ◽  
Author(s):  
Rifat Sipahi ◽  
Nejat Olgac
Keyword(s):  
Stability Analysis ◽  
Time Delay ◽  
Vibration Suppression ◽  
Linear Time ◽  
Direct Method ◽  
System Stability ◽  
Delayed Systems ◽  
Active Vibration Suppression ◽  
Active Vibration ◽  
The Stability

Various active vibration suppression techniques, which use feedback control, are implemented on the structures. In real application, time delay can not be avoided especially in the feedback line of the actively controlled systems. The effects of the delay have to be thoroughly understood from the perspective of system stability and the performance of the controlled system. Often used control laws are developed without taking the delay into account. They fulfill the design requirements when free of delay. As unavoidable delay appears, however, the performance of the control changes. This work addresses the stability analysis of such dynamics as the control law remains unchanged but carries the effect of feedback time-delay, which can be varied. For this stability analysis along the delay axis, we follow up a recent methodology of the authors, the Direct Method (DM), which offers a unique and unprecedented treatment of a general class of linear time invariant time delayed systems (LTI-TDS). We discuss the underlying features and the highlights of the method briefly. Over an example vibration suppression setting we declare the stability intervals of the dynamics in time delay space using the DM. Having assessed the stability, we then look at the frequency response characteristics of the system as performance indications.

scholarly journals Vibration Suppression of a 3-DOF Parallel Manipulator Based on Hybrid Negative Impulses Multi-Mode Input Shaping

2011 ◽  
Vol 2-3 ◽  
pp. 372-377 ◽  
Author(s):  
Yan Yan Han ◽  
Bing Li ◽  
Yu Lan Wei ◽  
Shou Xin Zhu ◽  
Ying Jun Dai
Keyword(s):  
Time Delay ◽  
Numerical Simulations ◽  
Parallel Manipulator ◽  
Vibration Suppression ◽  
Input Shaping ◽  
Vibration Modes ◽  
Residual Vibration ◽  
Input Shaper ◽  
Multi Mode

The classic multi-mode negative impulses input shapers can suppress the residual vibration of the multi-mode system effectively. But when these several frequencies bandwidths and amplitudes of vibration modes are greatly different, the time delay and the suppression performances of input shapers are decreased. However, the hybrid multi-mode negative impulses input shapers can overcome the disadvantage. The hybrid double-mode negative impulses input shapers of a 3-DOF parallel manipulator and are constructed and compared with the classic multi-mode negative impulses input shapers. And the numerical simulations are shown out, for different frequencies bandwidths and amplitudes of vibration, and the hybrid multi-mode negative impulses input shapers can increase the total suppression performance of input shaper.

Sign in / Sign up

Export Citation Format

Share Document