基于自适应状态观测器实现一类混沌系统同步

研究了一类具有未知参数的混沌系统,依据Lyapunov稳定理论,讨论了一种基于自适应状态观测器的混沌同步的方法,根据持续激励条件讨论了参数估计的收敛性,实现了响应系统与驱动系统的同步并估计出了未知参数。数字仿真结果证明了该方法的有效性。     

有界动态随机系统的观测器设计

提出了用于有界动态随机系统的状态观测器设计方法.首先利用平方根B样条逼近系统的输出概率密度函数来构造残差,同时利用李亚普诺夫函数方法得到观测器增益的自适应调节规律,然后提出了新的对数B样条逼近模型并设计了新的自适应观测器,两个仿真例子表明了方法的有效性.     

宗地图自动绘制软件的设计及实现

软件以Visual Basic语言为开发工具,通过CAD强大的绘图功能实现了宗地图的精确绘制和距离、面积的量算,输出坐标表。文章介绍了该程序的总体流程和关键点。     

Finite Memory Observers for linear time-varying systems. Part II: Observer and residual sensitivity

Fault detection and diagnosis are important issues in process engineering. Hence, considerable interest is growing in this field from industrial practitioners as well as academic researchers, as opposed to 30 years ago. This paper focusses on a model-based approach for fault detection. This approach is based on Finite Memory Observers (FMO), properties of this observer are presented in the first part of our work (Graton et al., 2014 [1]), the main results of this paper are recalled at the beginning of this paper and constitute the basis of this second part. Properties of the Finite Memory Observer (FMO) are studied from a global point of view for the class of linear time-varying (LTV) systems with stochastic noises. FMO performances take their framework from the study of their properties, and from the study of their influences on diagnosis results. Fundamentally, the generation of residuals is essential in a diagnosis procedure. In Graton et al. (2014) [1], the design for the finite memory observer is shown, the determination of its optimal window length is solved, and the generation of residuals for diagnosis is completed. This paper is the second part of this work and is devoted to the study of the observer and residual sensitivity towards model parameter variations and noises.     

适用于老旧小区改造的智能采集器的设计

本文设计了一种符合国家电网、南方电网的新型智能采集器,并对它的原理和实现做了详细阐述。该采集器采用RENESAS公司的uPD78F0526为主控制芯片,兼容DL/T645-1997和DL/T645-2007通信规约,自动适应电能表通信波特率。经过实际安装使用表明,设计的系统具有功耗低、运行稳定、抄读成功率高等特点,完全符合国家电网及南方电网要求。     

Order reduction of linear systems using an error minimization technique

A simple method is proposed for order reduction of linear continuous systems with real distinct eigenvalues. The steady state parts of the unit step responses of the original and reduced-order models are matched in this method. Zeros are synthesized by minimizing the error between the transient responses, where as dominant poles are retained. An example is solved to illustrate the superiority of the method over some existing ones.     

Map Out a Strategy for International Cooperation

International cooperation is a prerequisite for the successful .implementation of the national Knowledge Innovation Program (KIP) being piloted by CAS, and hence further efforts will be made to strengthen collaboration and exchanges with the outside world,stresses CAS President Lu Yongxiang.     

Constructing a Genomic Map for All Soybeans

Recently, a joint team of Chinese scientists at the CAS Institute of Genetics and Developmental Biology(IGDB) constructed a new genomic map that contains almost all the genetic information of soybeans by assembling the genomes of 26 representative strains around the world into one comprehensive pan-genome. This new map is expected to benefit the upcoming efforts in soybean breeding by associating genetic variations to agronomic traits.     

论科技人才发展状态监测评估指标体系的构建

基于德尔菲法和多元统计分析方法的运用,从科技人力资源投入要素指标、科技人才效能要素指标、科技人才发展条件要素指标等三个维度,构建一套科技人才发展状态监测评估指标体系,并进行案例应用.为区域科技人才发展状态监测评估提供一种在现有统计体系内的客观、可操作方法,并为研究和评价区域科技人才竞争力提供一种思路和依据.     

高阶Chebyshev低通滤波器的快速设计

Chebyshev滤波器是一种常用的高性能滤波器。本文通过对Chebyshev滤波器的系统函数的推导分解,提出了一种可以快速实现高阶Chebyshev低通滤波器电路的方法,并给出了设计高阶Chebyshev低通滤波器电路的各元器件参数的计算公式。最后运用该算法快速设计了一个7阶Chebyshev低通滤波器,并采用Saber软件对设计的7阶Chebyshev低通滤波器进行了理论分析验证。     

Observer based fault-tolerant control for a class of nonlinear networked control systems

In this paper, we present a fault-tolerant control (FTC) framework for a class of nonlinear networked control systems (NCSs). Firstly, the plant is transformed into two subsystems with one of them decoupled from the system fault. Then, the nonlinear observer is designed to provide the estimation of unmeasurable state and modelling uncertainty, which are used to construct fault estimation algorithm. Considering the sampling intervals occurred by net, a fault-tolerant control method is proposed for such nonlinear NCSs using the impulsive system techniques. The controller gain and the maximum sampling interval, which make the faulty system stable are given. An example is included to show the efficiency of the proposed method.     

State estimation for semi-Markovian switching CVNNs with quantization effects and linear fractional uncertainties

This paper is concerned with the robust state estimation problem for semi-Markovian switching complex-valued neural networks with quantization effects (QEs). The uncertain parameters are described by the linear fractional uncertainties (LFUs). To enhance the channel utilization and save the communication resources, the measured output is quantized before transmission by a logarithmic quantizer. The purpose of the problem under consideration is to design a full-order state estimator to estimate the complex-valued neuron states. Based on the Lyapunov stability theory, stochastic analysis method, and some improved integral inequalities, sufficient conditions are first derived to guarantee the estimation error system to be globally asymptotically stable in the mean square. Then, the desired state estimator can be directly designed after solving a set of matrix inequalities, which is robust against the LFUs and the QEs. In the end of the paper, one numerical example is provided to illustrate the feasibility and effectiveness of the proposed estimation design scheme.     

Observer design and stability analysis for a class of PDE chaotic systems

This paper deals with observer design and stability for a class of partial differential equation (PDE) systems governed by one-dimensional wave equations with mixed derivative terms and superlinear boundary conditions, whose dynamics exhibits chaos when the system parameters change within certain ranges. Firstly, a sufficient and necessary condition that guarantees the stability of this class of systems is obtained. Secondly, based on the method of characteristics, an observer is designed by injecting the measurement output estimation error on the boundary, and the observation error dynamics is proved to be stable with a necessary and sufficient criterion, which can identity the range of the feedback gain for the observer. Finally, two numerical examples are provided to illustrate the validity of the theoretical conclusions.     

Observer design for a class of nonlinear fractional-order systems with unknown input

A full order fractional-order observer is designed for a class of Lipschitz continuous-time nonlinear fractional-order systems with unknown input. Sufficient conditions of existence for the designed observer and stability of state estimation error system are developed by reconstructing state and using general quadratic Lyapunov function. By applying fractional-order extension of Lyapunov direct method, the stability of the fractional-order state estimation error system is analyzed. Due to the conditions involving a nonlinear matrix inequality, a new sufficient condition with linear matrix inequality (LMI) is reformulated, which makes the full order fractional-order observer implemented easily by using Matlab LMI toolbox. Examples are taken to show the effectiveness of the proposed approach by numerical simulations.     

State feedback uniform decoupling problem of linear time-varying analytic systems

A new approach to the input-output uniform decoupling problem of linear time-varying analytic systems via proportional state feedback is presented. A major feature of the proposed approach is that it reduces the solution of the uniform decoupling problem to that of solving a linear algebraic system of equations. This system of equations greatly facilitates the solution of the three major aspects of the decoupling problem: the necessary and sufficient conditions, the general analytical expressions for the controller matrices, and the structure of the uniformly decoupled closed-loop system.     

State and unknown input estimations for discrete-time switched linear systems with average dwell time

In this paper, the problem of state and unknown input estimations for a class of discrete-time switched linear systems with average dwell time switching is investigated. First, a proportional integral observer with an exponential H_∞ performance is constructed to estimate the system state and unknown input simultaneously. Second, both of the observability and the stability of the estimation error system are analyzed, then the derivation of the observer gain matrices is transformed into the calculation of linear matrix inequalities. Third, the obtained results are extended to the systems with output disturbances. Finally, two simulation examples are provided to show the validity and effectiveness of the proposed methods.     

地下电缆状态监测仪的设计

本文通过分析电缆发生故障的主要原因,设计了地下电缆状态监测仪.该监测仪可以对地下电缆的温度和湿度进行多点监测.实时处理监测数据.发现或预防地下电缆故障.     

Design,identification, and control of a linear dual-stage actuation positioning system

Voice coil actuators (VCAs) are widely used for motion control applications that require high precision and fast acceleration. However, they have one disadvantage of short travel ranges typically on the order of centimeters. To overcome this disadvantage, this paper employs an existing concept called dual-stage actuation and combines a linear VCA with a low-cost dc-motor (DCM) to construct a linear dual-stage actuation (DSA) positioning system, which extends the travel range as large as that provided by the DCM while retaining the positioning accuracy offered by the VCA. For this setup, proper controllers are crucial to achieve the desired performance. Hence, we first identify the DSA model and investigate the interaction force between the VCA and DCM stage. Next, robust controllers are specifically designed for the DCM and VCA stage, respectively. Finally, experiments are carried out to verify the robust tracking performance of the developed linear DSA positioning system. It is demonstrated that the developed DSA positioning system offered a cost-effective solution to extending the working range of the existing VCA whilst retaining the positioning accuracy.     

一类二阶非自治系统周期解的存在性

在二阶系统一系列定理基础上,建立一个直接根据系统Lyapunov函数性质判定系统周期解存在性的定理,针对一类二阶非自治非线性系统构造了适当的Lyapunov函数,并研究了这类系统周期解的存在性。