STUDY ON NONLINEAR DYNAMICS OF TCP-RENO TRAFFIC UNDER RED

The traditional net work management can tmeet the users requirements about quality of servicealong with the fast increasing of the scale of net-work.So service management has been proposed toguarantee the QoS of net work services and has beena hot topic in the research community for a fewyears now,and a lot of research has been carriedout[1-6].The net work traffic management is one ofthe key compositions of service management,andplays ani mportant role inthe QoS,congestion con-trol and net wo…     

Improved scheme of internet congestion control under moving average filter

An important task of Internet congestion control is inhibiting sporadic data flow to maintain a suitable window size or route queue length. Such a requirement is just consistent with the basic idea and function of a moving average filter. In this paper one prior Internet congestion control model, named transmission control protocol (TCP)/random early detection (RED) stroboscopic model, is studied, and then one new scheme is proposed to enlarge its stable domain, where a simple moving average filter is introduced to inhibit sporadic data flow as possible. In the novel scheme the bifurcation phenomenon is postponed without any extra controller. The effectiveness of the new scheme is verified by theoretical analyses and numerical simulations.     

一类周期系数力学系统分岔控制

为了控制周期系数微分系统平衡点失稳后的分岔行为,基于Floquet-Lyapunov理论,将控制常系数系统分岔行为的方法（线性法、参数法、平移法）应用于一类具有周期系数的力学微分系统,设计了相应的控制器,研究了其控制平衡点分岔行为的有效性.研究结果表明:平移法不能有效控制周期系数微分系统的平衡点失稳后发生的Flip分岔和Hopf分岔行为.若平衡点失稳发生Flip分岔形成周期2点,可分别采用线性法和参数法将周期2点控制到周期1点;若平衡点失稳发生Hopf分岔形成Hopf圈,可分别采用线性法和参数法将Hopf圈控制到周期1点.      

CMAC BASED NONLINEAR PROCESS CONTROL SYSTEMS,PART Ⅱ:CONTROLLER DESIGN

，ＰＡＲＴ Ⅱ：ＣＯＮＴＲＯＬＬＥＲ ＤＥＳＩＧＮTX＠段培永＠李成东＠邵惠鹤ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｒｅｃｅｎｔｙｅａｒｓ，ＮｅｕｒａｌＮｅｔｗｏｒｋｓ（ＮＮｓ）ｈａｖｅｆｏｕｎｄｇｒｏｗｉｎｇｓｕｃｃｅｓｓｉｎｄｉｖｅｒｓｅｉｎｉｎｄｕｓｔｒｉａｌｃ?..     

Hybrid control of delay induced hopf bifurcation of dynamical small-world network

In this paper, we focus on the Hopf bifurcation control of a small-world network model with time-delay. With emphasis on the relationship between the Hopf bifurcation and the time-delay, we investigate the effect of time-delay by choosing it as the bifurcation parameter. By using tools from control and bifurcation theory, it is proved that there exists a critical value of time-delay for the stability of the model. When the time-delay passes through the critical value, the model loses its stability and a Hopf bifurcation occurs. To enhance the stability of the model, we propose an improved hybrid control strategy in which state feedback and parameter perturbation are used. Through linear stability analysis, we show that by adjusting the control parameter properly, the onset of Hopf bifurcation of the controlled model can be delayed or eliminated without changing the equilibrium point of the model. Finally, numerical simulations are given to verify the theoretical analysis.     

采用PLL的电机速度控制系统

介绍了在采用通用变频器的交流调速系统中应用锁上技术的理论和方法，调速系统的结构及各部件的组成，并用实验证明了系统具有较高的控制精度。在得出系统数学模型的基础上，对系统的稳定性进行了分析，并讨论了各参数对系统稳定性的影响以及系统的调速范围。     

新型智能控制系统研究

本文从实际应用的高度出发，基于传统控制方法和智能控制思想，提出了一种新型智能控制（ＩＣ）结构，并应用小增益定量为闭环自学习智能控制系统建立了稳定性分析，给出了ｌ＾∞稳定性结果。该控制器已成功地应用于一温湿度自动控制系统，效果良好。     

Adaptive robust control for an active heave compensation system

Active heave compensation systems are usually employed in offshore and deep-sea operations to reduce the adverse impact of unexpected vessel’s vertical motion on the response of underwater instruments.This paper presents a control strategy for an active heave compensation system consisting of an electro-hydraulic system driven by a double rod actuator,which is subjected to parametric uncertainties and unmeasured environmental disturbances.Adaptive observer and discontinuous projection type updating law with bounded adaption rate are presented firstly to estimate the uncertain system parameters.Then a similar estimation algorithm is designed by using a multiple delayed version of the system to enhance the performance of parameter observation.A reduced order observer is also introduced to estimate unknown wave disturbances.Using the obtained uncertainty information,the resulting control development and stability analysis are implemented based on the Lyapunov’s direct method and back-stepping technique.The proposed controller guarantees the heave compensation error convergent to a bounded neighborhood around the origin.Simulations illustrate the effectiveness of the proposed control system.     

基于预瞄驾驶员模型的车辆操控稳定性分析

建立了高效、能适应复杂路况的驾驶员模型,以空间方程形式给出了一种基于最大预瞄距离的驾驶员模型;将驾驶员模型、汽车运动学模型及稳定性控制系统有机结合,采用最优控制理论方法,分析了基于该模型的人-车-路闭环控制系统的指数稳定性条件;运用仿真软件MATALB/Simulink建立了4轮车辆驾驶员模型,仿真结果验证了所建立的驾...     

一类振荡电路的混沌及其控制

研究了一个振荡电路的混沌形成过程,并利用分岔图、Lyapunov指数图以及相图分析了该系统的混沌行为.利用分岔控制和x|x|控制等两种方法实现了系统的混沌控制,将系统的混沌行为有效地控制到稳热定的周期轨道.其中,在分岔控制方法下,对受控系统做出了控制参数的系统分岔图,由分岔图可以得到控制到np的周期轨道的取值范围,在这范围内适当选择数值,将电路系统控制到p-1,p-2,p-4,p-8等周期轨道.x|x|控制是对混沌动力系统增加一个具有分段二次函数x|x|形式的非线性反馈控制器.仿真结果表明,这两种方法对控制电路系统的可行性.     

Electrostatic Suspension System Nonlinear Character Analysis and Its Internal Model Control

Nonlinearity is an important characteristic in electrostatic suspension system (ESS). This paper concludes the nonlinear parts in ESS, which generally result from the relationships between rotor displacement and capacitance, rotor displacement and electrostatic force, and control voltage and electrostatic force. In terms of the nonlinearities, a new control method with modified internal model control (IMC) was proposed to analyze the ESS, deduce the transfer function of the modified IMC controller in ESS, and simulate this new application in ESS. Comparing with proportional integral derivative (PID) control, IMC has only a parameter, and has better performance. As a result, IMC solves nonlinearity error well in ESS with only one uncertain parameter, and performs well when the rotor has large displacement.     

船舶航向非线性系统的输出反馈鲁棒控制

考虑船舶航向控制系统模型中存在非线性，假设模型参数和外界干扰有界的情况下，首先利用Lyapunov稳定性模型，提出了一种状态反馈鲁棒控制新算法的自动舵设计，进而考虑到实际船舶上，在进行航向控制时，并不是所有船舶运动状态都是可测的，仅有航向是可测的，采用一种高增益状态观测器对状态进行重构，提出了输出反馈鲁棒控制自动舵设计，以大连海事大学远洋实习船“育龙轮”为例，进行了输出反馈鲁棒控制自动舵设计，并利用Matlab工具箱进行了仿真研究，结果证明该算法是十分有效的。     

杜芬方程的仿真分析及混沌控制

为实现对系统的有效控制,针对杜芬方程在特定参数设置下所出现的混沌现象及其特性,提出了基于参数微扰和变量反馈的控制方法,这种方法能对混沌系统进行有效的控制,通过调节反馈系数k,就能得到新的运动轨迹．理论分析和系统仿真结果均表明该控制方法的可行性,得出了混沌特性被抑制或最终得到周期解的效果．     

列控车载设备控制程序及参数远程实时更新方法

针对既有列车控制系统不具备对车载设备控制程序及参数进行远程在线实时更新功能的问题,提出一种基于无线传输和嵌入式的列控车载设备控制程序与参数实时更新方法,在无线机车信号实际应用测试中表明,所实现的程序更新机制具有较高的适应性和可靠性,可有效提高运营中的车载设备程序升级效率,提高了对列车控制的安全性,降低了系统维护成本.     

车辆系统Hopf分叉的代数求解方法

运用运动稳定性及分叉理论,研究了非线性车辆系统的蛇行运动分叉现象,提出利用Ｈｕｒｗｉｔｚ行列式,给出平衡点失稳而发生Ｈｏｐｆ分叉的代数判定准则和计算方法,这一方法将Ｈｏｐｆ分叉点的求解转化为一个非线性方程的求解问题,并用此方法进行了客车系统运动稳定性的研究。     

基于泛布尔代数的多值逻辑控制与PID控制的仿真比较

为提高系统的动态性能,通过与传统的PID控制器比较,在此基础上提出一种基于泛布尔代数的多值逻辑控制器.此控制器物理背景明确,结构简单,数学概念清晰.Matlab仿真说明,其控制器要优于PID控制器,表现出稳定性好、响应快、超调量小的特点,在工业控制领域便于推广应用.     

Path following control of underactuated ships based on unscented Kalman filter

A path following controller is proposed to force an underactuated surface ship which is suffering from disturbance to follow a predefined path.The controller is based on analytic model predictive control and unscented Kalman filter(UKF) techniques.The analytic model predictive control provides a systematic method to get appropriate controller parameters to guarantee the stability of the closed-loop system,and the well-defined relative degree is guaranteed by introducing output-redefinition.The UKF is used t...     

具有时滞的Kaldor-Kalecki商业周期模型Hopf分支的频域分析

研究了一类具有时滞的Kaldor-Kalecki商业周期模型.首先,将时滞作为分支参数,应用Nyquist准则分析了Hopf分支的存在性;然后,应用频域法和图示Hopf分支定理研究了Hopf分支的方向和周期解的稳定性;最后,对该模型进行了数值仿真,仿真结果验证了理论分析的正确性.     

基于T-S模糊模型的Kawakami混沌系统的控制

研究了离散Kawakami混沌系统的模糊控制问题,利用单点模糊化、乘积推理和中心平均去模糊化模糊推理方法将Kawakami系统化为T-S模糊模型.在用T-S模糊模型重构了系统结构的基础上,利用反馈控制思想,借助于离散李亚普诺夫稳定性理论,给出了离散T-S模糊模型渐近稳定的充分条件,并设计出了相应的状态反馈控制器.利用线性矩阵不等式,进一步求出了模糊控制器的参数.仿真结果验证了该控制方法的有效性.     

谷值电流控制反激变换器的非线性现象

为了选取DC-DC变换器的参数,建立了谷值电流控制反激变换器动力学方程和离散映射模型,利用分岔图和庞加莱映射,研究了其复杂的非线性动力学行为,并对基于谷值参考电流和输入直流电压变化的稳定性和分岔特性进行了分析.通过Matlab/Simulink平台构造了相应的时域仿真模型,得到了谷值电流控制反激变换器的时域波形和相轨图.研究结果表明,谷值电流控制反激变换器存在非线性动力学行为,变换器随着电路参数的变化,从稳定状态经过倍周期分岔和边界碰撞分岔进入混沌状态.