Sharif Digital Repository

A modification to the control law presented in [Y. Lei, W. Xu, H. Zheng, Synchronization of two chaotic nonlinear gyros using active control, Phys. Lett. A 343 (2005) 153] is proposed. © 2007 Elsevier B.V. All rights reserved  

In synchronization of identical chaotic systems, the control cost would be optimal in the sense that it would be zero when the synchronization is occurred. Based on this idea, in synchronization of non-identical chaotic systems, we find a signal function added to states of the derive system so that it makes the dynamics of the drive system translated into dynamics of the response system. After synchronizing two systems using this function, states of the response system will be synchronized with the equivalent states and the control cost will be optimal similar to those in the identical synchronization. © ICROS  

This paper deals with the synchronization of two Lur'e differential inclusions containing sector nonlinearity. Lyapunov stability theorem is employed to design the control inputs. The controllers are designed considering three important practical features in physical systems. First, differential equation part of the Lur'e differential inclusion is assumed to be convex. Second, it is presumed that parameters of the Lur'e differential inclusion are not completely known. Third, sector nonlinearities are considered on control inputs applied to the Lur'e differential inclusions. To assess performance and effectiveness of the proposed controllers, synchronization of two rotor dynamic systems is... 

Synchronization of two fractional order hyperchaotic systems considering uncertainties and sector nonlinear inputs is investigated in this paper. A new fractional order sliding mode control scheme is proposed to synchronize two different fractional order hyperchaotic systems in the presence of uncertainties, sector nonlinearity in the control inputs. The stability of the error dynamics is proven using Lyapunov stability theorem. Simulation results are provided to verify the feasibility and effectiveness of the proposed synchronizing method  

In this paper the problem of synchronization between two chaotic gyros with stochastic base excitation, based on the mater-slave scheme, is studied. The stochastic excitation is modeled by applying a Gaussian white noise to the deterministic model of gyro. The white noise is derived from the Wiener process, so the resulted system is a stochastic differential equation and is modeled by an Ito differential form. Using a modified sliding mode control a Markov synchronizing control law is designed and the convergence of error states to the sliding surface in the mean square norm is analytically proved. Simulation results show the high performance of the proposed controller in stochastic chaos... 

Design, implementation and experimental evaluation of a classic PID, and a modern Generalized Predictive Control (GPC) for an off-pump heart tracking system were carried out. Following the design and simulation analysis of the controllers, experimental evaluation was conducted on the slave robot of SINA tele-operational surgical system. Results revealed that considering the volatile high-frequency/speed pattern of heart motion, the agility of the controlled system is the most influential factor on its performance. With this in mind, unlike the Ziegler-Nichols-based tuned PID with emphasis on steady-state condition, the PID control with more transient behavior showed a superior performance.... 

Design, implementation and experimental evaluation of a classic PID, and a modern Generalized Predictive Control (GPC) for an off-pump heart tracking system were carried out. Following the design and simulation analysis of the controllers, experimental evaluation was conducted on the slave robot of SINA tele-operational surgical system. Results revealed that considering the volatile high-frequency/speed pattern of heart motion, the agility of the controlled system is the most influential factor on its performance. With this in mind, unlike the Ziegler-Nichols-based tuned PID with emphasis on steady-state condition, the PID control with more transient behavior showed a superior performance.... 

This paper presents an algorithm for synchronizing two different chaotic systems by using a combination of Unscented Kalman-Bucy Filter (UKBF) and sliding mode controller. It is assumed that the drive chaotic system is perturbed by white noise and shows stochastic chaotic behavior. In addition the output of the system does not contain the whole state variables of the system, and it is also affected by some independent white noise. By combining the UKBF and the sliding mode control, a synchronizing control law is proposed. Simulation results show the ability of the proposed method in synchronizing chaotic systems in presence of noise  

In this paper, the synchronization of a pair of pacemaker cells as Sino-Atrial (SA) and Atrio-Ventricullar (AV) nodes have been studied and a new approach for synchronization, based on the concept of Phase Response Curve (PRC), has been proposed. The paper starts with presenting the necessary and sufficient conditions for synchronization in terms of the PRC parameters. Such conditions are time dependent and thus, the paper proceeds with deriving some sufficient conditions, which are not time dependent. The time-delay between the firing time of SA node and when it reaches the AV node is also considered. When the conditions for spontaneous synchronization are not valid, the synchronization is... 

In this article, an adaptive nonlinear controller is designed to synchronize two uncertain fractional-order chaotic systems using fractional-order sliding mode control. The controller structure and adaptation laws are chosen such that asymptotic stability of the closed-loop control system is guaranteed. The adaptation laws are being calculated from a proper sliding surface using the Lyapunov stability theory. This method guarantees the closed-loop control system robustness against the system uncertainties and external disturbances. Eventually, the presented method is used to synchronize two fractional-order gyro and Duffing systems, and the numerical simulation results demonstrate the... 

Common methods of gait generation of bipedal locomotion based on experimental results, can successfully synthesize biped joints' profiles for a simple walking. However, most of these methods lack sufficient physical backgrounds which can cause major problems for bipeds when performing fast locomotion such as running and jumping. In order to develop a more accurate gait generation method, a thorough study of human running and jumping seems to be necessary. Most biomechanics researchers observed that human dynamics, during fast locomotion, can be modeled by a simple spring loaded inverted pendulum system. Considering this observation, a simple approach for bipedal gait generation in fast... 

Due to the highly dynamic nature of Wireless Sensor Networks (WSN), Software-Defined Network (SDN) is a promising technology to ease network management by providing a logically centralized control plane. It is a common approach to employ multiple SDN controllers to form a physically distributed SDN to achieve better fault tolerance, boost scalability, and enhance performance. Despite physical distribution, since the notion behind SDN is to logically centralize network management, it is essential to provide a consistent view of the network's state for all controllers. Deploying multiple controllers result in higher synchronization and deployment cost. Since network performance and...