基于非线性规划的人体上肢运动研究

该文对非线性规划技术在人体上肢运动中的应用进行了研究,对解逆运动学问题的几种数值方法进行了分析和比较.然后根据这些方法的比较结果,该文选用了BFGS变度量法来求解与逆运动学问题等价的最小化问题,这种方法有良好的数值稳定性且对奇异矩阵不敏感,计算代价不高,程序设计也比较简单.最后,针对上肢的小范围运动设计了仿真系统,并和其他几种解逆运动学问题的方法在计算时间上进行了比较,结果表明了该方法的有效性和可行性.     

结合模型匹配与特征跟踪的人体上半身三维运动姿态恢复方法

人体姿态空间的高维性及单目视频深度信息丢失,导致从单目视频恢复人体三维运动姿态非常困难,为此,利用特征跟踪的快速性及模型匹配的鲁棒性,提出一种无标记人体上半身三维运动跟踪方法.该方法利用匹配SIFT特征,并根据长度不变性约束建立优化目标函数,再采用迭代优化算法得到全局运动位姿;其他关节的姿态先根据逆运动学计算初始估计值,并通过模型匹配验证其可信度,当初始姿态估计错误时,则使用局部搜索获得关节姿态.实验结果表明,文中方法可以准确地恢复单目视频中人体上半身三维运动姿态.     

基于单目视觉的机器人逆运动学分析

本文介绍了一种通过单目视觉测量,实现机器人的自主定位的数学方法.利用运动学建模确立了目标从图像到实际工作空间的映射关系,得到目标的实际位置和姿态,并利用三点法对KLD-600机器人进行逆运动学求解.实验表明,该方法操作简单,计算准确,运算速度快.     

仿人机器人复杂动作设计中人体运动数据提取及分析方法

提出了仿人机器人复杂动作设计中人体运动数据提取及分析方法. 首先, 通过运动捕捉系统获取人体运动数据, 并采用运动重定向技术, 输出人--机简化模型的数据; 然后, 对运动数据进行分析和运动学解算, 给出基于人体运动数据的仿人机器人逆运动学求解方法, 得到仿人机器人模型的关节角数据; 再经过运动学约束和稳定性调节后, 生成能够应用于仿人机器人的运动轨迹. 最终, 通过在仿人机器人BHR-2上进行刀术实验验证了该方法的有效性.     

具有避障能力的虚拟人姿态优化算法

为了解决复杂环境下的虚拟人运动控制问题,提出一种基于人工势场的具有避障能力的虚拟人姿态优化算法.首先在虚拟环境中根据目标和障碍物建立人工势场,并对虚拟人运动链末端进行无碰撞路径规划;其次将规划后末端每个中间位姿的逆运动学计算问题表示为带位姿和无碰撞约束的舒适度函数优化问题,并进行求解;最后得到虚拟人运动过程中一系列连续的无碰撞姿态,实现自行避障的虚拟人运动控制.通过实例测试验证了文中算法的有效性,该算法可应用于复杂环境下的虚拟人动画和人机工程仿真.     

全局和声搜索方法及其在仿人灵巧臂逆运动学求解中的应用

仿人灵巧臂逆运动学(IK)问题可转化为等效的最小化问题,并采用数值优化方法求解.和声搜索(HS)是模拟乐师在音乐演奏中调整音调现象的一种启发式搜索方法,目前还尚未在机器人机械臂逆运动学问题中得到应用.本文提出一种基于粒子群体智能的全局和声搜索方法(GHSA),该方法在和声搜索算法中引入微粒群操作(PSO),采用粒子群策略替代常规和声搜索算法中的搜索法则创作新和声,通过粒子自身认知和群体知识更新和声变量位置信息平衡算法对解空间全局探索与局部开发间能力;同时算法还引入变异操作增强算法跳出局部最优解能力,基准函数测试表明该方法改善了全局搜索能力及求解可靠性.在此基础上以七自由度(7-DOF)冗余仿人灵巧臂为例,考虑以灵巧臂末端位姿误差和“舒适度”指标构建适应度函数并采用GHSA算法求解其逆运动学(IK)问题,数值仿真结果表明了该方法是解决仿人灵巧臂逆运动学问题的一种有效方法.     

基于Kinect深度相机的实时三维人体动画

研究了一种基于H Anim标准的实时人体三维动画方法,首先对H Anim中人体肢体层次结构进行研究和分析,给出了进行人体动画的坐标变换方法;其次,基于OpenNI对Kinect获取的数据进行重新处理,采用逆运动学计算非根关节旋转矩阵;最后给出了系统流程及具体实验方法,采用OpenGL由实时获取的关节旋转矩阵驱动虚拟人实现了人体动画。实验结果表明,该算法可以较精确地提取人体三维姿态,实时重构人体运动。     

虚拟环境中的多手指抓取操作技术

抓取操作是虚拟手操作的关键部分.为了实现无力反馈条件下抓取的真实准确,提出一种虚拟环境中的虚拟手抓取方法.通过建立虚拟手结构模型和采用状态变换描述抓取过程,实现了未被抓取和被抓取时的模型运动控制;对逆运动学循环坐标下降算法进行改进,并结合正向运动学方法调整手指姿态,解决了手指穿透问题;通过确立抓取条件,保证了抓取操作的真实准确.利用二次开发环境CAA将数据手套与CATIA V5集成,在无力反馈虚拟原型系统中实现了简单模型的抓取,证明了文中方法的正确性及实时性.     

仿人机器人逆运动学在线求解方法研究

针对仿人机器人逆运动学在线求解问题,从计算实时性与数值稳定性的角度展开研究。分析了仿人机器人下肢拓扑结构,建立其运动学模型与前向运动学描述,根据当前机器人逆运动学算法研究成果,将几何方法与阻尼最小二乘法相结合,并结合分段阻尼思想,提出一种仿人机器人在线逆运动学求解算法。根据运动规划结果,将所提方法与基于雅可比矩阵的广义逆方法通过仿真算例进行对比,验证了所提方法在奇异位形附近的数值稳定性和在线实施的可行性。     

约束条件下的巡线机器人逆运动学求解

高压输电线路巡检机器人是一种多关节悬挂运动机构,要实现其运动控制就需要根据机器人的本身机构特点和悬挂系统的运动约束条件进行运动学分析.本文利用微分扭转法对巡线机器人的正向运动学进行了求解,并通过对机器人悬挂系统的力学分析,得到了机器人运动学的约束条件,并在这种约束条件下,采用了一种可用来进行实时控制的迭代循环坐标下降(CCD)算法,来进行机器人的逆运动学求解.这种迭代算法对于有运动约束系统的逆运动学求解具有较强的适用性,而且它具有较好的收敛性和有效性,适合于在线计算,便于巡线机器人的实时运动控制.     

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.     

Call for Papers The 6^th International Conference on Grid and Cooperative Computing

Recent years have seen rapid advances in various grid-related technologies, middleware, and applications. The GCC conference has become one of the largest scientific events worldwide in grid and cooperative computing. The 6th international conference on grid and cooperative computing (GCC2007) Sponsored by China Computer Federation (CCF),Institute of Computing Technology, Chinese Academy of Sciences (ICT) and Xinjiang University ,and in Cooperation with IEEE Computer Soceity ,is to be held from August 16 to 18, 2007 in Urumchi, Xinjiang, China.     

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.     

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.     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and     

Editorial:Brain-machine interface(BMI) and cyborg intelligence

正Brain-machine interfaces(BMIs)aim at building a direct communication pathway between the brain and an external device,and represent an area of research where significant progress has been made during the past decade.Based on BMIs,mind information can be read out by neural signals to control     

Information for Authors

正http://www.zju.edu.cn/jzus http://www.springerlink.com Aim The Journals of Zhejiang University-SCIENCE(A/B/C)are edited by the international board of distinguished Chinese and foreign scientists,and are aimed to present the latest developments and achievements in scientific research in China and overseas to the world’s scientific circles,especially to stimulate     

SCIENCE CHINA Information Sciences SUBJECT INDEX TO VOLUME 57(2014)

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