一类时滞混沌系统的修正函数投影拟同步

参数失配是基于同步技术的混沌保密通信研究中不可回避的问题.以典型的Lur'e时滞混沌系统为研究对象,利用脉冲控制技术,在驱动-响应系统参数发生失配的情况下,实现了驱动-响应系统的修正函数投影拟同步,同时给出了拟同步的充分条件,估计了拟同步误差限,最后通过数值仿真验证了理论分析的正确有效性.     

基于Lorenz混沌系统的同步控制方法仿真

由于受到噪声、干扰以及系统不稳定的影响,混沌同步保密通信很难避免两个系统参数完全相同的扰动,甚至可以使原先同步的系统失去同步或带来较大误差.该文以Lorenz动力学系统为对象,基于同步理念,设计了一种当系统参数未知时的同步控制方法.该方法在系统单状态同步控制的基础上,通过设计合适的控制器和参数自适应律,实现相同结构而参数互异混沌的系统渐近同步,并以典型的Lorenz混沌系统进行了仿真,结果表明该方法可以很好的达到同步控制要求,验证了所提方案的可行性.     

一种自适应混沌同步方法及其在信息传输中的应用

基于自适应误差反馈策略,利用同步误差对系统参数进行调整,并采取策略对信道噪声进行一定程度的补偿,实现了两个具有参数失配的混沌系统的同步。并在此基础上利用参数调制和参数估计策略,实现了信息传输。     

基于比例微分反馈控制思想的不同类型混沌系统同步方法

提出一种新的混沌同步思想,在"命令匹配”的概念基础上,设计比例微分同步控制策略,并结合扩张状态观测器原理,使所得的控制策略满足混沌保密通信的要求.以Duf丘ng和VabdI阳系统为例进行仿真,同步效果良好.     

基于直接构造法的不同参数统一混沌系统的同步

研究不同参数统一混沌系统的同步问题.首先采用直接构造法为响应系统设计适当的控制器,将误差系统 化成三对角结构;然后根据具有三对角结构的非线性系统状态全局渐近稳定的性质,得到误差系统状态在原点渐近稳定,进而实现驱动系统与响应系统的同步;最后在参数相同和参数不同两种情况下.分别对统一混沌系统的同步进行数值仿真,仿真结果表明所提出的设计方法是有效的.     

利用部分状态反馈的统一混沌系统的混沌同步

通常混沌同步控制器的设计大都需要全部状态或多个输入,对此利用Lyapunov函数和一些不等式技巧,给出一种新的同步控制器设计方法.该方法仅使用一个输入一个状态反馈,或仅使用两个输入一个状态反馈设计Lorenz混沌系统和Unified混沌系统的同步控制器,实现了二者全局指数混沌同步.该控制器只需一个状态变量,结构简单,实现容易,而且所给算法减小了参数选取的保守性.算例仿真结果表明了所给方法的有效性.     

优化策略在不同类型混沌系统同步中的应用

利用Ｌａｇｒａｎｇｅ优化策略设计同步控制器,根据扩张状态观测器（ＥＳＯ）对系统之间的结构信息进行渐进估计,给出一个可实现的同步制策略,实现了两个不同结构的混沌系统之间的同步。以Ｄｕｆｆｉｎｇ和Ｖａｎｄｅｒ Ｐｏｌ系统为例进行仿真,效果良好。     

一类永磁电动机的混沌反控制研究

研究了永磁同步电动机系统在不改变电机结构参数条件下的混沌反控制问题.该方法借鉴非线性系统模型跟踪控制的思想,利用电机系统和混沌系统状态变量之间的关系来设计控制器.根据误差的变化,控制器随时做出响应,强迫被控系统的状态变量从非混沌状态转化为混沌状态.实现了永磁同步电动机系统比较精确跟踪混沌系统的过程.本文方法中控制器参数的选取范围比较宽,为控制器设计带来很大方便.仿真结果验证了本文控制方法的有效性.     

外激励参数未知系统的同步控制及其参数识别

考虑外激励的振幅和频率未知的混沌系统.把系统未知参数扩张成系统的新的状态量,构造新的驱动系统.用参数自适应控制方法构造一个响应系统,使之与驱动系统的结构相同.基于级联系统的稳定性理论,通过两个步骤来设计控制器和参数自适应律,使得驱动—响应系统能够达到完全同步.当驱动—响应系统达到完全同步时,就可以识别出系统的未知参数振...     

采用鲁棒滑模观测器实现一类混沌系统的同步

提出一种鲁棒滑模观测器，并应用于一类混沌系统的同步，该鲁棒滑模观测器通过滑模与相应的控制策略来实现，可调整观测器跟踪系统状态的收敛速度，实现两个混沌系统的同步，将所提出的鲁棒滑模状态观测器用于一类存在参数摄动和／或干扰的混沌系统的同步具有鲁棒性，该鲁棒滑模状态观测器不仅能实现低维的混沌系统的同步，而且能实现超混沌系统的同步，以Chua’s电路和超混沌Roessler系统为例给出了设计过程和仿真实验，其结果验证了所提出方法的有效性。     

Extended Kalman filters for fractional‐order nonlinear continuous‐time systems containing unknown parameters with correlated colored noises

By using the Grünwald‐Letnikov (G‐L) difference method and the Tustin generating function method, this study presents extended Kalman filters to achieve satisfactory state estimation for fractional‐order nonlinear continuous‐time systems that containing some unknown parameters with the correlated fractional‐order colored noises. Based on the G‐L difference method and the Tustin generating function method, the difference equations corresponding to fractional‐order nonlinear continuous‐time systems are constructed respectively. The first‐order Taylor expansion is used to linearize the nonlinear functions in the estimated system, which provides the system model for extended Kalman filters. Using the augmented vector method, the unknown parameters are regarded as new state vectors, and the augmented difference equation is constructed. Based on the augmented difference equation, extended Kalman filters are designed to estimate the state of fractional‐order nonlinear systems with process noise as fractional‐order colored noise or measurement noise as fractional‐order colored noise. Meanwhile, the extended Kalman filters proposed in this paper can also estimate the unknown parameters effectively. Finally, the effectiveness of the proposed extended Kalman filters is validated in simulation with two examples.     

基于操作系统调用的容错计算机系统同步技术研究

同步是实现基于表决的容错计算机系统的关键过程．现有的采用基于硬件或应用软件同步技术的系统存在设计和制造困难、兼客性差和难以使用等问题．提出了一种基于操作系统调用的同步机制；描述了其同步算法；介绍了在Linux操作系统上的实现．该同步机制对应用程序完全透明，同步点无需人工设置，同步算法由软件和硬件结合的方式实现．实验结果表明该同步机制是可行的，较好地达到了系统易设计和好使用的目标．     

Observer‐based compensation control of servo systems with backlash

For compensating backlash phenomenon in servo systems, the authors propose an observer method in this paper to estimate both system states and vibration torque before controller design. First, a systematic scheme is given to obtain plant parameters, which is very important in observing system states. This is a parameter estimation principle that gives a crude estimation and computes the differences between the crude and true values. As a result, the precise value of the parameters is obtained by adding together the crude value and the difference. Then, based on the precise estimated parameters, an extended state observer (ESO) is designed to obtain feedback and feedforward signals. Consequently, robust compensation control is achieved by designing an output feedback controller, consisting of a feedback term and a feedforward term. Finally, in order to validate the proposed approach, extensive experiments are performed on a practical servo system with backlash nonlinearity.     

Attributed Transition Systems with Hidden Transitions

This paper conducts the set-theoretic analysis of the structure of attributed transition systems with hidden transitions on the assumption that the set of states for which the set of transitions can be extended is fixed and does not change the system structure. Cases are investigated when priorities of hidden and available actions coincide or the priority of hidden actions is higher than the priority of available actions. In terms of systems with singled out initial and final states, the classes of admissible, safe, and correct systems are defined and characterized. The algebra of such systems is constructed.     

VSS theory-based disturbance estimation scheme for MIMO systems and its applications

Based on variable structure systems (VSS) theory, this paper presents a new method of estimating the disturbances (or system nonlinearities and any model uncertainties) for continuous-time multi-input multi-output (MIMO) minimum phase (with respect to the relation between the disturbance and the output) dynamical systems. The designed robust method requires only the input and output measurements of the system. Even for MIMO systems under the assumption that the partial states directly affected by the disturbances do not directly appear in the outputs (when it is considered in the state space), the disturbances can still be estimated by applying the proposed formulation. The estimated disturbances are then employed to construct a robust state observer. Further, the estimated disturbances and the state observer are applied to synthesize a controller to place the desired stable poles and to cancel the disturbances. A design example and simulation results are presented to show the practicality and effectiveness of the proposed algorithm.     

基于输入-输出线性化方法实现混沌系统的同步

本文将非线性控制系统的输入-输出线性化方法应用于混沌系统的同步中。首先对发送系统和接收系统进行适当的坐标变换，分别得到一个具有规范型或类规范型的新系统，再对两个新系统进行比较得到误差系统．然后通过对误差系统进行反馈变换，从而实现混沌系统的输出及其导数的同步．当满足一定条件．还可实现所有状念变量的同步．此方法所需的发送信号仅为标量信号，适于保密通信。对Lorenz系统、Rossler系统的仿真证明了该方法的有效性。     

A knowledge-based system for information management in an automated and integrated manufacturing system

In recent years there has been considerable interest in flexible automation of manufacturing processes in an effort to improve the productivity of manufacturing industry. Central to an integrated, flexible and intelligent manufacturing system is the information management function. The sharing of data is the basis of flexible and intelligent decision-making, the means of integrating the system components, the mode of synchronizing their processes and the method of maintaining the consistency of their states.

It appears that the data management and manipulation function in manufacturing systems is increasingly becoming a bottleneck for further performance improvement of manufacturing systems. New information management systems need to be developed that meet the needs of modern manufacturing systems in terms of efficiency, flexibility, reliability and intelligence. A new model for an integrated manufacturing information system is presented. A double structure of two parallel but independent system is proposed for manufacturing control and manufacturing information management. The objective is to improve service efficiency. representational adequacy, consistency of information and reliability in the information system.