前置式磁控电弧传感器焊缝自动跟踪系统

针对目前机械式电弧传感器普遍存在的问题,将磁场控制电弧技术应用于焊缝跟踪,设计了磁控电弧传感器和一种双十字滑块的结构系统,对采样信号采用了RCπ型滤波和巴特沃思滤波器进行双级滤波,提出了有限区间去极值离散积分比较法来提取实际焊缝坡口的偏差信息。焊缝跟踪试验验证了该系统的有效性。     

新型旋转电弧传感系统的研究

介绍了旋转电弧传感器用于焊缝跟踪的工作原理.针对空间狭窄、折角变化大的焊缝跟踪场合,研制了一种结构更紧凑,工作更稳定的新型旋转电弧传感器.设计了电弧传感器的旋转位置检测电路和以单片机为核心控制器的转速闭环及调速控制电路.实验证明:所设计的电路抗干扰强、测位可靠、转速稳定、调速准确.该传感系统已在轮式移动焊接机器人焊缝跟踪控制系统中得到成功应用.     

机器人基于电弧传感器对90°折线角焊缝的跟踪

针对准确跟踪90°折线角焊缝比较困难的问题,提出了一种基于旋转电弧传感器和路径规划组合的方法.通过对旋转电弧传感器采集到的焊接电流进行滤波,采用最小二乘偏差识别和模糊控制算法,控制机器人左右轮差速运动或水平滑块伸缩.直角拐弯时基于路径规划和水平滑块伸缩跟踪焊缝,未进入直角拐弯时是基于左右轮差速运动跟踪焊缝.实验结果表明,该算法能够很好地实现90°折线角焊缝的跟踪.     

人工神经网络在焊缝跟踪中的应用

本文将人工神经网络用于焊缝跟踪系统中，研制了一种新型的焊缝跟踪用传感器－神经电弧传感器，该传感器成本低，操作简单，工作可靠，将其用于焊缝跟踪系统中，能够得到满意的跟踪效果。     

超声波传感器在直角焊缝自动焊接中的应用

机器人进行船体格子型焊缝焊接过程中,完全依靠电弧传感器无法完全得到其周围环境信息,造成了自动化焊接的困难。设计了一种直角焊缝自动焊接的方法,利用超声波传感器代替机械式传感器,获得周围障碍信息,用电弧传感器获得焊缝的偏差信息,通过对机器人合理的控制,完成了直角焊缝的自动跟踪焊接。     

基于模糊控制的电弧焊接焊缝跟踪技术研究

针对V型坡口焊缝,采用摆动扫描式电弧传感器,研制了基于模糊控制的焊缝跟踪系统.主要介绍了焊缝跟踪系统的组成,完成了模糊控制器算法的设计,离线完成模糊控制查询表.在焊接过程中,系统采用ARM微处理器实现焊缝跟踪的查表工作,从而实现焊接时焊缝的精确跟踪,使焊枪对中焊缝.该系统无需建立被控对象的精确数学模型,改善了伺服驱动系统的动静态特性,提高了焊缝跟踪的精度.     

高速旋转电弧传感焊缝偏差信息识别的研究

以空心轴电机直接驱动的高速旋转电弧传感器是焊接应用中使用的一种传感器,国内外将它应用于焊缝跟踪系统中,并进行了大量的研究。介绍了该传感器的结构与工作原理,阐述了采用特征谐波检测法识别焊缝偏差信号的方法。利用该方法对V形坡口进行了金属熔化极气体保护电弧焊(MIG)的跟踪试验,试验结果验证了所用方法的有效性。     

旋转电弧传感弧焊机器人焊缝实时纠偏系统研究

本文介绍了以高速旋转电弧为传感器的弧焊机器人焊缝实时纠偏系统 ,首先设计了适应机器人要求的高速旋转电弧传感器 ,然后对电弧传感 V形坡口焊缝的识别方法及铁水等干扰影响进行了研究 ,采用模糊控制技术进行焊缝实时纠偏 ,最后完成了 V形坡口直线焊和角焊缝折线焊 ,取得了满意的焊缝纠偏结果 .     

一种基于激光结构光的焊缝跟踪视觉传感器

焊缝自动跟踪是实现焊接自动化的关键.本文在总结不同焊缝跟踪传感器研究的基础上,设计了一种基于激光结构光的视觉传感器.针对不同类型焊缝(V形、U形坡口焊缝、搭接、对接焊缝和第一道焊焊缝、多道焊焊缝等)的图像特点,开发了焊缝激光图像处理模块库,可以提取出焊缝特征点位置坐标,实现焊缝跟踪.实验证明,传感器具有较高的精度和可靠性,并对焊缝跟踪系统具有一定的普适性.     

用高速旋转电弧信号进行焊缝的模糊跟踪

本文介绍了高速旋转电弧焊进行的角焊缝跟踪的计算机应用技术，主要内容有旋转电弧传感器获取焊距与焊缝偏差信号的机理和方法，进行焊缝跟踪的模糊控制的分析与推算以及以８０９８单片机为主体的控制系统软硬件构成。     

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.     

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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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