上肢康复外骨骼机器人的模糊滑模导纳控制

为了辅助上肢运动功能障碍患者进行不同模式的康复训练,基于上肢康复外骨骼机器人系统,提出了一种模糊滑模导纳控制策略,实现训练过程的人机协调控制.首先,介绍了康复外骨骼的整体结构和实时控制平台.然后,分析了模糊滑模导纳控制算法的推导过程,并根据李亚普诺夫稳定性判据证明系统的稳定性.最后,在不同系统导纳参数条件下,分别进行被动训练模式和主动训练模式实验,并对比分析了实验过程中运动偏差、人机交互力以及肱二头肌表面肌电信号的变化特点.实验结果表明,选择合适的目标导纳模型可以优化康复训练强度与难度,提高人机交互柔顺性与患者参与度,满足不同瘫痪程度和康复进度患者的训练需求.     

基于无模型自适应的外骨骼式上肢康复机器人主动交互训练控制方法

设计了一种基于无模型自适应的外骨骼式上肢康复机器人主动交互训练控制方法.在机器人与人体上肢接触面安装力传感器采集人机交互力矩信息作为量化的主动运动意图,设计了一种无模型自适应滤波算法使交互力矩变得平滑而连贯;以人机交互力矩为输入,综合考虑机器人末端点与参考轨迹的相对位置和补偿力的信息,设计了人机交互阻抗控制器,用于调节各关节的给定目标速度;设计了将无模型自适应与离散滑模趋近律相结合的速度控制器完成机器人各关节对目标速度的跟踪.仿真结果表明,该控制方法可以实现外骨骼式上肢康复机器人辅助患者完成主动交互训练的功能.通过调节人机交互阻抗控制器的相应参数,机器人可以按照患者的运动意图完成不同的主动交互训练任务,并在运动出现偏差时予以矫正.控制器在设计实现过程中不要求复杂准确的动力学建模和参数识别,并有一定的抗干扰性和通用性.     

基于BP神经网络补偿的下肢外骨骼位置控制

坐卧式康复外骨骼机器人可以帮助下肢功能障碍患者进行康复训练,为实现康复训练的位置控制目标,通过深入分析人机耦合关系,建立包括穿戴者、外骨骼在内的耦合运动学/动力学模型,提出了基于人机混合系统动力学模型的带前馈补偿项的PD控制算法,然而为了实现良好的运动轨迹跟踪性能,必须在位置控制算法中加入对不确定项的补偿,因此提出一种基于BP神经网络补偿的位置控制算法并通过仿真验证算法的高效性。     

面向人机交互的下肢外骨骼自适应轨迹跟踪

在可穿戴下肢外骨骼助力系统的轨迹跟踪控制研究中,针对系统存在人机交互力耦合,建立了人机耦合高阶动力学模型,提出了一种单自由度下肢外骨骼系统的人机协同控制策略.考虑系统存在的模型误差和外界干扰,采用了干扰观测器对系统总扰动进行动态观测和实时补偿;针对模型参数因人而异且难以准确获取的问题,设计了自适应反步滑模控制器;根据Lyapunov稳定性分析,证明了闭环系统渐进稳定.仿真结果表明系统能够快速准确地跟踪期望轨迹且具有较强的鲁棒性,验证了自适应反步滑模控制器的有效性.     

下肢软质康复外骨骼机器人的模糊神经网络阻抗控制

针对脑卒中或交通意外等因素导致的运动功能障碍问题,设计了一种可用于康复训练的可穿戴式的软质膝关节外骨骼机器人．在重点介绍基于Hill肌肉模型的套索人工肌肉驱动系统设计和实时控制平台的基础上,分析了模糊神经网络阻抗控制算法的推导过程．最后,分别在定阻抗与变阻抗参数控制策略条件下,进行人机协同训练模式下的康复训练实验,并对比分析了康复外骨骼系统对受试者肌肉活性的影响．实验结果表明,定频率定幅值训练时的屈/伸扭矩分别增加了9.70%和9.06%,而变频率变幅值训练时的屈/伸扭矩提升了88.34%和57.68%．由此可知,选择符合人体生理肌肉刚度特性的阻抗模型可以改善下肢康复机器人系统的稳定性和安全性,提高人机交互的柔顺性和协调性．     

基于人机偏差模型的自对齐髋关节外骨骼解耦设计与计算

针对辅助外骨骼,分析了单自由度人机交互中的人机偏差因素,建立人机偏差变量模型,运用自对齐机构设计理论设计外骨骼机构,以提升人机耦合性能.首先,深入分析了单自由度人体生物关节,建立了人体简化模型+人机偏差变量模型的外骨骼设计模型参考.然后,运用自对齐机构设计理论和多自由度关节解耦方法,提出了自对齐人体运动的外骨骼机构设计思路与方法.最后,以下肢髋关节为对象,将髋关节外骨骼解耦为3个单自由度关节,设计了髋关节助力外骨骼的运动形式,并进行了人机耦合下的外骨骼动态静力驱动计算.结果显示,该运动设计使人机偏差交互力变得可控,从理论上证明了髋关节外骨骼机构能够跟随下肢运动并提供自适应人体的驱动助力.     

基于阻抗模型的下肢康复机器人交互控制系统设计

为帮助下肢功能障碍患者进行康复训练,设计了下肢康复机器人。对于该机器人的控制,采用传统系统无法柔顺控制,导致机器人运动轨迹偏离预设轨迹。针对该现象,提出了基于阻抗模型的下肢康复机器人交互控制系统设计。通过分析总体控制方案,设计系统硬件结构框图。采用L型二维力传感器,确定两个方向的人机交互力。使用绝对值编码器安装在各个关节处,其输出值作为髋关节、膝关节、踝关节电机的转动位置,增量编码器安装在电机轴上,测量值用来作为后期控制方法的输入参数。构建阻抗控制模型,能够调节机器人位置和速度,具有消除力误差功能。依据此力矩对参考运动轨迹进行设计,实时获取患者康复训练的跟踪、主动柔顺和接近状态信息。在柔顺训练实验测出人机交互力,通过实验结果知,在检测到人体主动力矩异常时,系统能够重新优化轨迹,具有良好柔顺控制效果。     

下肢康复机器人的自适应人机交互控制策略

针对康复机器人运动过程中的人机交互性问题,提出一种下肢康复机器人自适应人机交互控制策略.提取伸屈运动中下肢表面肌电信号（Surface electromyography,sEMG）和足底压力特征,分别用于表征下肢运动意图和人机交互力（Interaction force,IF）信息,建立基于sEMG-IF的人机交互信息融合模型,实现下肢康复机器人运动轨迹的在线规划;考虑主动康复运动过程中的人机交互作用,建立具有时变动态特性的人机系统动力学模型,设计间接模糊自适应控制器对期望轨迹进行跟踪控制,实现下肢康复机器人自适应人机交互控制.通过对5名被试者进行下肢康复机器人运动控制实验研究,验证所提方法的可行性和有效性.     

基于人机交互的重载机械臂控制方法

针对目前重载机械臂控制系统存在的人机交互性不足问题及重载带来的刚柔耦合问题,设计了一种基于动力学模型的人机交互闭环力!/!位控制算法,并依据该算法设计了7自由度重载机械臂控制系统.首先分析了国内外重载机械臂的工作特点和存在的问题,提出基于力!/!视觉反馈的人机交互方式来增强系统的人机交互性;然后为抑制刚柔耦合带来的控制问题,建立了重载机械臂刚柔耦合动力学模型,提出基于人机交互的重载机械臂力!/!位闭环控制算法.最后搭建重载机械臂控制系统,搭建的控制系统包括人机交互子系统、环境感知子系统、驱动子系统、信息处理子系统及通信子系统.在此基础上,进行重载机械臂控制系统作业试验.试验结果表明,该控制系统能够完成人机交互作业功能,相对于传统重载机械臂作业手段,有效提高了作业效率70%,保障了作业人员安全,验证了所提出控制系统的人机友好性、可行性和实用性.     

基于模糊补偿的主从式上肢外骨骼康复机器人训练控制方法

针对主从式上肢外骨骼康复机器人主臂信息获取、从臂快速响应等问题,提出了基于关节位姿、速度和力/力矩等信息的运动意图建模方法及基于模糊补偿的康复训练控制策略.根据人体工程学原理,提出了一种同构同型的主从式双臂康复机器人新型结构;利用D-H算法给出了笛卡儿空间的主从臂运动学模型,建立了患者健肢运动意图信息和从臂各关节动作的人机协作映射关系;以患者运动意图力矩作为输入,基于模糊补偿算法提出了患者-主臂-从臂协作控制策略,并利用李亚普诺夫定理证明了该控制系统的稳定性.仿真结果表明,康复机器人从臂可以根据患者运动意图跟随主臂运动,能有效地防止抖动误动,可避免对患肢的二次伤害.实验结果表明从臂运动轨迹平滑,无剧烈波动,控制轨迹跟踪主臂效果好.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

The Distributed Time-Triggered Simulation Scheme: Core Principles and Supporting Execution Engine

Distributed real-time simulation is a young technology field but its practice is under increasing demands. In recent years the author and his collaborators have been establishing a new approach called the distributed time-triggered simulation (DTS) scheme which is conceptually simple and easy to use but widely applicable. The concept was initiated in the course of developing a new-generation object-oriented real-time programming scheme called the time-triggered message-triggered object (TMO) programming scheme. Some fundamental issues inherent in distributed real-time simulation that were learned during recent experimental studies are discussed along with some approaches for resolving the issues. An execution engine developed to support both the TMOs engaged in control computation and the TMOs engaged in DTS is also discussed along with its possible extensions that will enable significantly larger-scale DTSs.     

Software-Konfigurationsmanagement in großen Softwareprojekten

Zusammenfassung Mit zunehmender Größe der Softwaresysteme verschärfen sich die für die Software-Herstellung typischen Probleme: Beherrschen großer Objektmengen, Erhalten der Systemkonsistenz, Kontrolle der ständigen Änderungseinflüsse und Gewährleisten einer langen Lebensdauer. Die Disziplin Konfigurationsmanagement bildet den methodischen Ansatz, diese Probleme besser zu beherrschen. Software-Konfigurationsmanagement faßt die Herstellung von Softwaresystemen als eine Abfolge von kontrollierten Änderungen an gesicherten Zwischen- und Endergebnissen auf. Dargestellt werden die Objekte und Funktionen des Software-Konfigurationsmanagements sowie die hierfür in großen Software-Projekten benötigten Methoden, Instanzen und Hilfsmittel.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。