iFIX组态软件在污水处理控制系统中的应用

介绍了组态软件iFIX在污水控制系统中的应用情况,对iFIX组态软件的特点进行了简介说明以及对整个污水处理控制系统的组成进行了阐述,提出了系统进行组态过程中的两个主要技术问题,iFIX和关系数据库的通讯以及日报表的生成,并提供了解决方法,同时给出了解决报表的部分主要程序代码。     

Color segmentation robust to brightness variations by using B-spline curve modeling

Color segmentation takes a great attention because color is an effective and robust visual cue for characterizing an object from the others. However, color segmentation suffers from color variations incurred by irregular illumination changes. We propose a reliable color modeling approach in hue–saturation–intensity (HSI) color space while considering intensity information by adopting the B-spline curve fitting to make a mathematical model for statistical characteristics of a color with respect to intensity. It is based on the fact that color distribution of a single-colored object is not invariant with respect to brightness variations even in the HS (hue–saturation) plane. The statistical characteristics contain the mean and standard deviation of hue and saturation with respect to intensity. They are mathematically expressed as four bar graphs. In order to fit the bar graphs to continuous curves, we use B-spline curve fitting procedure. From several experimental results, we verify that the proposed algorithm is successfully applied to color segmentation under various illumination conditions.     

Image categorization: Graph edit distance+edge direction histogram

This paper presents a novel algorithm for computing graph edit distance (GED) in image categorization. This algorithm is purely structural, i.e., it needs only connectivity structure of the graph and does not draw on node or edge attributes. There are two major contributions: (1) Introducing edge direction histogram (EDH) to characterize shape features of images. It is shown that GED can be employed as distance of EDHs. This algorithm is completely independent on cost function which is difficult to be defined exactly. (2) Computing distance of EDHs with earth mover distance (EMD) which takes neighborhood bins into account so as to compute distance of EDHs correctly. A set of experiments demonstrate that the newly presented algorithm is available for classifying and clustering images and is immune to the planar rotation of images. Compared with GED from spectral seriation, our algorithm can capture the structure change of graphs better and consume 12.79% time used by the former one. The average classification rate is 5% and average clustering rate is 25% higher than the spectral seriation method.     

一类不确定切换奇异系统的动态输出反馈鲁棒H∞控制

研究一类由任意有限多个不确定子系统组成的切换奇异系统的动态输出反馈鲁棒H∞控制问题. 利用共同 Lyapunov 函数方法和凸组合技术, 给出由矩阵不等式表示的控制器存在的充分条件, 并设计了相应的子控制器和切换策略. 采用消元法, 将该矩阵不等式转化为一组线性矩阵不等式 (LMIs). 最后, 数值实例验证了所提方法的有效性.     

非最小相位逐维定位多模型自适应解耦控制器

针对多变量系统中多个参数同时跳变导致模型数目巨大、计算时闻长等问题.提出了采用逐维定位技术的多模型自适应解耦控制器.该方法将多维空间的并行寻优问题转化为多个一维空间的串行寻优问题,可大大减少系统模型集的数量.针对非最小相位系统,将系统的耦合作用视为可测干扰,采用前馈方法予以消除.最后给出全局收敛性分析.仿真结果表明当采用相同数目的模型时,其控制效果明显优于常规多模型控制器.     

Multicriteria decisions on interdependent infrastructure transportation projects using an evolutionary-based framework

When evaluating transportation infrastructure projects and determining which of them will be carried out from a set of projects and given a budget constraint, several criteria need to be considered in the decision. Standard evaluation practices imply the aggregation of impacts into one utility function which is later optimized. Nevertheless these techniques used for translation of different measuring units into monetary terms are highly controversial. Multicriteria techniques can explicitly deal with different measuring units, however, they are not suitable to model interdependence relationships of projects that share a common characteristic (same route, location or target population, for instance). In this research we model this transportation planning problem, the multi-objective transportation infrastructure project selection problem (MTIPSP), as a constrained multi-objective optimization problem with quadratic objective functions, using a variation of the multi-objective 0–1 knapsack problem plus some additional constraints. Given the combinatorial nature of the problem, an evolutionary-based framework is used for the identification of Pareto solutions, and later, those with non-attractive properties are filtered using a Knee Identification Procedure. The final selection of the projects portfolio is made using a well known multicriteria decision aid method and including the decision makers’ preferences based on the existing context.     

Design and realization of hybrid ACO-based PID and LuGre friction compensation controller for three degree-of-freedom high precision flight simulator

Three degree-of-freedom (3-DOF) high precision flight simulator is a type of key hardware-in-loop equipment in the fields of aeronautics and astronautics. The conventional Proportional–Integral–Derivative (PID) is a widely used industrial controller that uses a combination of proportional, integral and derivative action on the control error to form the output of the controller. It is well known that the undesired phenomena caused by friction can lead to overall flight simulator performance degradation or instability. This paper presents a novel kind of hybrid Ant Colony Optimization (ACO)-based PID and LuGre friction compensation controller for 3-DOF high precision flight simulator. On the basis of introduction of the basic principles of ACO, the controlling scheme design for the 3-DOF high precision flight simulator is presented. Based on the popular LuGre friction model, a novel nonlinear friction compensation controller for 3-DOF high precision flight simulator is also developed. The proposed Lyapunov function proves the robust global convergence of the tracking error. The parameters tuning of PID can be summed up as the typical continual spatial optimization problem, grid-based searching strategy is adopted in the improved ACO algorithm, and self-adaptive control strategy for the pheromone decay parameter is also adopted. Modularization design is adopted in the 3-DOF high precision flight simulator. This software can process the position and status signals, and display them on the friendly interface. Double buffer mechanism is adopted in the communication protocol between lower Industrial Personal Computer (IPC) and upper IPC. The series experimental results have verified the feasibility and effectiveness of the proposed hybrid ACO-based PID and LuGre friction compensation controller.     

一种以太网边缘扫描控制器设计方案

利用嵌入式技术开发了以太网边缘扫描控制器,该控制器实现了以太网接入功能,可以测试任何符合IEEE1149．1标准的器件、电路板和系统。     

基于LabWindows／CVI的数据库应用程序开发

LabWindows／CVI是测试领域优秀的开发软件,用于开发大型、复杂的测试软件,能获得优良的测试性能,而MicrosoftAccess的数据库开发能力也十分强大,两者的结合可以使得需要测试大量指标和处理大量测试数据的自动测试系统的开发变得更加容易。本文以某电台信号处理模块的自动测试系统的开发为例,详细说明如何在眦Windows／CVI中访问Microsoft Access制作的数据库。结果表明,由此给自动测试系统在数据处理和数据存储方面提高了数倍效率。     

低耗低剖面单层波导阵列天线研究

新型单层波导阵列天线具有低耗、低剖面、结构紧凑、实用性强等诸多优点, 在毫米波甚至太赫兹无线通信领域具有巨大应用潜力, 是当前的研究热点。 文章首先介绍了用于构建波导阵列天线的几类波导馈电网络的特点, 指出E 面波导馈电网络在毫米波应用领域的优势,接着针对E 面波导在单层并馈波导阵列天线和Butler矩阵多波束阵列天线方面的研究展开叙述,最后给出了可应用在单层波导阵列天线中的开口波导辐射单元在实现多频和圆极化等不同功能上的最新研究进展。 文章对于低耗低剖面单层波导阵列天线的发展及其应用具有参考价值。