面向微粒操纵的介电泳芯片系统研究

针对目前在纳米器件及传感器的制造中尚无对大量粒子进行有效操纵的方法,我们利用介电泳方法对大量微粒进行定位和传输操纵,介绍了利用MEMS工艺进行介电泳芯片加工的过程以及整个观测与实验系统的建立,通过有限元软件对传统介电泳和行波介电泳中电极阵列的电场分布进行求解,并在该实验系统下实现了对微通道中的悬浮高度和微粒的运动速度的测量.该实验系统的研究为液体环境下微纳颗粒的装配和分离提供了一条有效的技术路径.     

一种套件精密对接自动装配实验系统

针对点火靶装配中的套件对接装配,搭建了一套可实现微米级定位、视觉和力觉检测的装配实验平台.通过对装配零件的分类判别以及对应图像的识别检测,实现了位置闭环控制.对套件对接圆环的装配过程进行了分析并建立了装配力模型,在该模型的基础上提出了装配力控制方法.最后,对所研制的自动装配实验系统进行了定位和对接实验,验证了系统的装配力控制、装配精度和效率.     

毫米器件半自动微装配系统研制

微靶是惯性约束聚变研究中的一个关键器件,针对该器件研制了一种半自动微装配系统,该系统可以对由两半腔(直径约800～1000μm,长1 mm左右)和微球(直径200～500μm)组成的微器件进行半自动装配。详细介绍了该系统的结构与组成及其所采用的关键技术与解决方案,分析了装配过程显微在线检测系统误差影响因素,并建立了测量误差数学模型。装配实验表明:该系统的装配精度≤10μm。     

基于机器视觉的机械手装配系统设计

为了解决工业生产过程中料板的自动装配问题,提出了一种基于机器视觉的机械手定位装配检测系统,建立了实验平台。系统通过工业相机对料盘进行图像采集,将所采集的信息传送给工控机,借助图像处理程序,采用图像预处理实现了对图像的降噪,结合BLOB分析对图像特征进行了提取,获得了料盘上装配孔的位置信息,通过控制机械手动作,移动到装配位置,旋转相应角度,实现料板的自动定位装配。实验结果表明,该系统装配准确度高,误差小,满足了工业上的要求。     

基于多传感器的微装配系统研究

1引言 随着MEMS(微机电系统)技术的发展,对于各种光学元件、压力传感器、加速度计等微型精密元件的年需求量已达数百万.微器件的加工与装配越来越引起人们的关注,许多研究单位对于微器件进行了研究与开发.微小零件的精密加工中存在的主要问题是:如何以微观精度和低成本实现微小零件的加工与装配.近些年来,基于IC工艺和深层X射线技术也被成功用于复杂工艺的微机械零件的加工.但是,对于那些由多个不同材料不同工艺加工而成的微小器件组成的混杂系统,往往需要进行一步或多步的装配.有时也需要将常规元件与微元件装配在一个系统中.这些都需要先进的定位技术和高度灵活的装配仪器.利用常规的设备进行上述操作,实现起来很困难,而且成本很高.     

微操纵系统自动调焦方法的研究

讨论了在微操纵系统中显微成像的自动调焦方法。首先介绍了一些常用的自动调焦方法,然后重点讲述了清晰度法自动调焦原理．对各种清晰度评价函数进行了分类,并通过理论和实验分析比较了在微操纵系统中各种评价函数的性能,最后确定了适合微操纵系统的清晰度评价函数。     

锥壳靶自动精密微装配系统

为解决多尺度、多形状的锥壳靶精密装配问题,研制了一套具有微米级定位精度的多操作手精密微装配系统.该系统具有3个多自由度操作手,能够针对不同形状、不同材质的零件进行拾取、装配.在显微视觉景深较小及装配空间光照有限的条件下,采用提升小波算法获得清晰的零件与操作手图像并进行相应图像的识别检测,实现了位置的闭环控制.通过3路显微视觉实现靶零件的在线测量,直线测量不确定度小于2μm,角度测量不确定度小于0.01?.装配实验结果表明,该系统能够保证微球中心与锥轴线的偏差小于5μm,微球中心与柱腔中心偏差小于10μm,与手动装配相比大大提高了装配精度.     

无线移动传感器网络节点自定位控制仿真研究

研究移动节点确认自身位置信息的节点自定位问题,传感器节点的移动部署和数据通信容易受外界环境的干扰,造成网络节点自定位精度低。为解决上述问题,提出了一种改进的灰色系统预测移动节点定位技术。改进方法采用跨层设计,利用灰色系统预测移动节点及其相邻节点移动状态和距离来实时地根据自身及相邻节点位置重新成簇进而实现移动节点自定位控制。仿真表明,提出的灰色系统预测模型能够有效地提高了移动节点位置计算精度,在算法时空复杂度和能效上可以实现合理的自定位控制。     

视觉反馈的微装配自动调焦系统

基于视觉反馈的微装配自动调焦系统由可调焦光学显微镜、CCD、图像采集卡、步进电机和齿轮减速传动机构等组成.它采用粗精组合式调焦算法,即使用Variance调焦函数结合优化爬山法进行粗调来确定聚焦目标区域,并应用梯度平方函数进行精调;最后用最小二乘法拟合得到焦平面位置.实验证明,该自动词焦方法具有响应速度快、精度高等特性,满足了微装配调焦对精度的要求.     

多尺度异型零件精密装配关键技术研究与系统开发

随着对操作的精度和可靠性的要求越来越高,精密装配技术与系统近年来受到广泛的关注。本文分析了自动精密装配领域的国内外研究现状,结合以点火靶装配为应用对象的多尺度异型零件精密装配研究,从装配对象、装配系统、系统标定、控制策略以及装配实现等方面探讨精密微装配的发展、关键技术及研究成果。     

Exceptional C or C with exceptions

C does not have exception handling facilities. Errors are handled by examining the value returned by each function and signals (conditions reported to the program) are handled by using library functions. These approaches lead to ad hoc error-handling techniques and can make programs hard to understand. Exceptional C, a superset of C, provides exception handling facilities. Exceptional C integrates the two techniques used by C programmers (i.e., status values and signals) to handle errors into one unified exception handling mechanism. In this paper, I review exception handling models, specify the criteria used for designing the exception handling facilities in Exceptional C, and then describe these facilities. I also illustrate the use of the exception handling facilities with examples.     

A biomechanical assessment of floor and overhead lifts using one or two caregivers for patient transfers

This study investigated the differences in peak external hand forces and external moments generated at the L5/S1 joint of the low back due to maneuvering loaded floor-based and overhead-mounted patient lifting devices using one and two caregivers. Hand forces and external moments at the L5/S1 joint were estimated from ground reaction forces and motion capture data. Caregivers gave ratings of perceived exertion as well as their opinions regarding overhead vs. floor lifts. Use of overhead lifts resulted in significantly lower back loads than floor lifts. Two caregivers working together with a floor lift did not reduce loads on the primary caregiver compared to the single-caregiver case. In contrast, two-caregiver operation of an overhead lift did result in reduced loads compared to the single-caregiver case. Therefore, overhead lifts should be used whenever possible to reduce the risk of back injury to caregivers. The use of two caregivers does not compensate for the poorer performance of floor lifts.     

Review paper A comparative study of methods for establishing load handling capabilities

There has been much effort in recent years to quantify manual handling capabilities. Four main techniques have been used to this end; biomechanical modelling; the measurement of intra-abdominal pressure; psychophysics; and metabolic/physiological criteria. The aim of this study was to compare quantitatively the data produced from the first three techniques. The comparisons were limited to bimanual, sagittal plane lifting, which of all manual handling activities has been studied the most comprehensively, except that pushing and pulling data were compared from the psychophysics and intra-abdominal pressure (‘force limits’) databases. It was found that the data from ‘force limits’ proposed weights for bimanual lifting in the sagittal plane are lower than those reported to be psychophysically acceptable except for lifting close to and around the shoulder. The closest agreement between the databases was for lifting from an origin above knuckle height. The ‘force limits’ data were found to propose weights of lift which are at a minimum when lifting with a freestyle posture from the floor whereas the psychophysical technique proposes weights which are at a maximum when lifting from the floor. The psychophysical data were found to generate compressive forces at L5/S1 according to a static sagittal plane biomechanical model about 10% in excess of the NIOSH action limit (NIOSH 1981) when lifting from the floor, although over other lifting ranges the compressive forces were less than the NIOSH action limit. Lifting the (force limits) weights generated compressive forces which were on average 55% less than the AL (range 45 to 60%) when lifting in an erect posture. The data for pushing according to the psychophysical and ‘force limits’ database showed good agreement, but for pulling the ‘force limits’ weights were considerably greater than those selected psych ophysically. The implications of these findings are discussed.     

International consensus on manual handling of people in the healthcare sector: Technical report ISO/TR 12296

In 1990 the European Union introduced a directive on manual handling in the health and social care industries. A review of the implementation in 2004 found a wide variation in official national guidance on patient handling. This paper reports the iterative development of a Technical Report (ISO/TR 12296) by the international standards Technical Committee ISO/TC 159, Ergonomics, Subcommittee SC 3, Anthropometry and Biomechanics representing 23 participating and 12 observing countries with expert support from the European Panel on Patient Handling Ergonomics. The process included 6 reviews over 3 years to produce a consensus document as a state of science summary. It has an overarching framework of risk management with sections on risk estimation and evaluation, organisational aspects, aids and equipment, buildings and the environment, staff training and education and intervention evaluation.     

Context aware exception handling in business process execution language

ContextFault handling represents a very important aspect of business process functioning. However, fault handling has thus far been solved statically, requiring the definition of fault handlers and handling logic to be defined at design time, which requires a great deal of effort, is error-prone and relatively difficult to maintain and extend. It is sometimes even impossible to define all fault handlers at design time.ObjectiveTo address this issue, we describe a novel context-aware architecture for fault handling in executable business process, which enables dynamic fault handling during business process execution.MethodWe performed analysis of existing fault handling disadvantages of WS-BPEL. We designed the artifact which complements existing statically defined fault handling in such a way that faults can be defined dynamically during business process run-time. We evaluated the artifact with analysis of system performance and performed a comparison against a set of well known workflow exception handling patterns.ResultsWe designed an artifact, that comprises an Observer component, Exception Handler Bus, Exception Knowledge Base and Solution Repository. A system performance analysis shows a significantly decreased repair time with the use of context aware activities. We proved that the designed artifact extends the range of supported workflow exception handling patterns.ConclusionThe artifact presented in this research considerably improves static fault handling, as it enables the dynamic fault resolution of semantically similar faults with continuous enhancement of fault handling in run-time. It also results in broader support of workflow exception handling patterns.     

某型航母舰载机机库内调运方法设计

航母机库是存放、检修维护舰载机和进行飞行前准备工作的重要场所。舰载机在机库内的调运效率直接影响其出动率,因此需要结合调运小组和各调运设备,设计合理的方法来保证调运流程的顺利进行。本文分析国外某型航母舰载机机库内调运流程,将其划为5个阶段,并参考操作系统中进程调度的概念,使用短进程优先的方法设计出2种调运方法,并对这2种方法进行了分析。     

The effects of caregiver experience on low back loads during floor and overhead lift maneuvering activities

This study investigated the effects of caregiver experience on peak external forces and moments generated at the L5/S1 joint of the low back when maneuvering loaded floor-based and overhead-mounted patient lifting devices. Twenty caregivers were divided into more-experienced and less-experienced groups based on the product of two factors: their years of lifting experience and the frequency of lifting the caregivers had done in the past. Ground reaction forces and moments as well as motion capture data were recorded while caregivers performed five different maneuvering tasks with both lifts in each of three conditions (caregiver subjects worked alone, as the primary caregiver in a pair, and as the secondary caregiver in a pair). Six outcome measures (net external forces and moments at the L5/S1 joint) were recorded. Multivariate analyses of variance of all net external forces and moments were done separately for the floor and overhead lifts. A significant effect of experience level was found for the floor lift (p = 0.006) but not for the overhead lift (p = 0.163). A follow-up univariate analysis of floor lift activities found significant differences between more-experienced and less-experienced caregivers for Turn, Push and Legs Up activities.

Relevance to industry

Previous work has shown that overhead lifts reduce the loads on caregivers compared to floor lifts. The findings of this study further underscore the need to purchase overhead lifts to protect less-experienced caregivers (including informal family caregivers) who are at increased risk of back injury when maneuvering floor lifts.     

Simulation-based baggage handling system merge analysis

This paper details the investigation into the design and control of merging bottlenecks of conveyor-based baggage handling systems, encompassing the merging control algorithm and the impact of the merge’s physical layout. A methodology for the analysis of simulation model results is presented. Results show that the layout of the merge influences bag throughput and when the physical configuration is in a preferred position, input variance has no effect on bag throughput performance. These results have potential application to other material handling systems, such as those used in manufacturing and warehousing.     

Java虚拟机异常处理机制的设计与实现

异常处理机制是程序设计语言的重要特征之一,它为开发可靠性软件系统提供了强有力的支持,介绍了不同语言的异常处理机制,对Ｊａｖａ语言的异常处理机制进行了详细论述,最后结合国产开放系统平台ＣＯＳＩＸ虚拟机异常处理的设计,深入探讨了在解释才及时编译执行两种不同的情况下,异常处理设计与实现的关键技术。     

工作流异常处理技术与方法

首先介绍了工作流异常处理的体系结构,然后详细介绍了异常处理在流程建模中的描述方式和异常处理的四个基本方法：事务特性与程序设计结合法、知识库法、ECA规则法和工作流进化法。最后展望了工作流异常处理的未来发展方向。