On the model-based networked control for singularly perturbed systems

In this paper, the control of a two-time-scale plant, where the sensor is connected to a linear controller/actuator via a network is addressed. The slow and fast systems of singularly perturbed systems are used to produce an estimate of the plant state behavior between transmission times, by which one can reduce the usage of the network. The approximate solutions of the whole systems are derived and it is shown that the whole systems via the network control are generally asymptotically stable as long as their slow and fast systems are both stable. These results are also extended to the case of network delay.     

非平衡拓扑结构的多智能体网络系统一致性协议

针对多智能体网络系统,本文分别研究了非平衡拓扑结构的多智能体连续状态和离散状态下的一致性协议.首先提出了能使用有向图表示的多智能体网络系统的拓扑结构,并根据该拓扑结构建立了网络系统的1阶数学模型和提出了多智能体网络系统一致收敛准则.对于多智能体网络连续系统,该系统的一致平衡点最终收敛于初始状态的凸组合,本文最终确定了非平衡拓扑结构的一致平衡点.如果多智能体网络系统的拓扑结构没有改变,在离散状态下系统的一致平衡点仍收敛于初始状态的凸组合,并且离散状态下系统的一致平衡点与连续状态下系统的一致平衡点相等.最后采用8个智能体组成的网络拓扑进行计算机仿真,验证理论的正确性.     

面向离散型制造业的MES的研究与设计

针对离散型制造业的行业特点,分析了MES的体系架构,利用J2EE的分布式多层应用开发与部署平台,构建具有多层结构的制造执行系统。提出了适合离散型制造业的功能模块。介绍了该系统的设计与应用。     

具有输出时延的网络控制系统故障检测

考虑一类具有长时延的网络控制系统,假定其传感器到控制器之间存在输出时延,对其进行故障检测研究.建立具有时延补偿功能的故障观测器,得到状态估计误差方程.基于离散切换系统理论,将观测器系统的稳定条件归结为一个线性矩阵不等式.当系统正常时,只要给定的矩阵不等式条件成立,该观测器系统就是渐近稳定的.当系统发生故障时,观测器残差能够迅速发生跳变,从而检测出故障的发生.仿真示例验证了方法的有效性.     

A study of roll‐printing technology for TFT‐LCD fabrication

Abstract— Recently, potential breakthrough technologies for low‐cost processing of TFT‐LCDs and new process developments for flexible‐display fabrication have been widely studied. A roll‐printing process using etch‐resist material as a replacement for photolithographic patterning was investigated. The characterization of the properties of patterns formed in roll printing, a method to fabricate cliché plates for fine patterns, and the design of a new formulation for resist printing ink is reported. The pattern position accuracy, which is one of the most important issues for the successful application of printing processes in display manufacturing was studied and how it can be improved by optimizing the blanket roll structure is explained. New design rules for the layout of the thin‐film‐transistor array was derived to improve the compatibility of roll printing. As a result, a prototype 15‐in.‐XGA TFT‐LCD panel was fabricated by using printing processes to replace all the photolithographic patterning steps conventionally used.     

Discrimination of visual and haptic rendering delays in networked environments

Many networked human-machine interface systems have a distributed structure for certain purposes such as more computational power, tele-presence, collaboration, and portability. However, network delays are inevitable in the distributed structure, and often make sensory information delivered behind time to the user. In the literature, the effect of network delays on the quality of information presentation has been considered with respect to task performances in most cases. In this paper, we pay attention to a more stringent criterion, namely whether perceptual artifacts caused by network delays are perceptible by the user. We examined minimum perceptible visual and/or haptic rendering delays by measuring their discrimination thresholds between normal and delayed virtual environments with and without a task, and report the results in this paper. We also provide a simple guideline for determining whether active delay compensation algorithms are required in a networked human-machine interface system by comparing representative network delays to the measured discrimination thresholds. Recommended by Guest Editor Phill Kyu Rhee. This work was supported in parts by a grant R01-2006-000-10808-0 and a NRL grant R0A-2008-000-20087-0 both from KOSEF and by a ITRC support program C1090-0804-0002 from IITA, all funded by the Korea government. In Lee is a Ph.D student in Computer Science and Engineering at POSTECH, of Korea. He received the B.S. degree in Information and Communication Engineering from Sungkyunkwan University in 2006. His research interests include haptics, virtual reality, and human-computer interaction. Seungmoon Choi is an Assistant Professor in Computer Science and engineering at POSTECH, Korea. He received the B.S. and M.S. degrees in Control and Instrumentation Engineering from Seoul National University in 1995 and 1997, respectively, and the Ph.D. degree in Electrical and Computer Engineering from Purdue University in 2003. His research areas include haptics, virtual reality, data perceptualization, and applied perception.     

A -based layout design for gratings allocation

In the design process of gratings, the grating layout design is the most important activity influencing manufacturing cost. In the grating layout design, the key to saving manufacturing cost is to find a design with a minimal number of cutting operations. This paper presents an application of the A^* algorithm in grating layout design. The design problem is represented as the space search problem of design alternatives. A^* explores the feasible alternatives within the space, until an optimal solution is obtained.     

小批量多元控制图建模方法研究

在分析研究现有小批量及多元控制图相关理论的基础上,基于Kalman滤波原理,提出一种综合解决小批量多元过程控制的建模方法。仿真实验及应用实例表明,该建模方法能够充分利用已经取得的数据,动态建立控制模型,从而解决小批量生产过程中建模数据不足的问题。     

基于网络控制系统的感应电机非线性控制

针对网络控制系统中存在不确定时延的问题,讨论了网络条件下感应电机的建模与控制．首先基于感应电机的非线性数学模型,运用直接反馈化方法将其线性化,然后在线性化的基础上引入具有时延的网络控制系统,建立了感应电机的网络化控制模型．运用李亚普诺夫函数方法,给出了闭环系统渐近稳定的充分条件,基于相应的线性矩阵不等式可行解,可以求解状态反馈控制律．最后,仿真结果验证了该方法的有效性．     

控制与通信协同设计的新进展

详尽地论述、分析、对比和讨论了网络化控制系统中的控制与通信协同设计问题．通过对该问题国内外研究现状的分析,强调了控制与通信协同设计研究的必要性、重要性和紧迫性,并着重从通信序列及通信协议两个方面阐述了控制与通信协同设计研究领域存在的不足、现有解决策略及主要结果的分析和对比,从而指出该领域急需解决的科学问题、可能的求解方向和今后的发展趋势,并为将来的研究工作提出了有益的建议和参考思路．