悬臂式掘进机截割机构状态诊断策略研究

悬臂式掘进机工作中常会遇到煤层硬度突然变大,使截割机构发生异常,甚至导致截齿断裂、减速器齿轮受损、截割电机转子不平衡等故障.为了实现对掘进机截割机构运行状态的远程监控,在分析掘进机截割机构工作原理及重要部件频率特征的基础上,采用Hilbert-Huang分析方法,在MATLAB中仿真得到了四种不同状态下振动信号的频谱特征和能量特征,基于支持向量机算法设计了系统的多故障分类器,通过仿真测试验证了上述分类器能有效地诊断出系统的故障部件,为实现掘进机截割机构运行状态的远程监控奠定了基础.     

掘进机截齿磨损程度分析及识别方法

为了实现掘进机截齿磨损程度的精确识别,提出了掘进机截齿磨损程度分析及识别方法,测试和提取了不同磨损程度截齿截割过程中的三向振动信号和电流信号,建立了各截割特征信号的样本证据组,采用基于修改模型的D-S组合识别模型实现了截齿磨损程度在线识别。实验结果表明,该方法能够根据多截割特征信号实现截齿磨损程度的精确识别,具有较高的识别精度和可靠性,为确定截齿的最佳维护和更换周期提供了重要依据。     

考虑煤岩硬度的悬臂式掘进机截割控制

煤岩硬度显著影响悬臂式掘进机空间运行状态,分析掘进机空间运行状态与煤岩硬度变化的关联性,有助于更好地实现悬臂式掘进机自动化截割控制。为提高截割控制精度,提出了一种考虑煤岩硬度的悬臂式掘进机截割控制方法。根据动力学原理获得了悬臂式掘进机空间运行状态与煤岩硬度变化的关系,得出随着截割头与目标点之间的距离、运动范围半径及动态角度增大,截割头的运行稳定性会相应提高。采用加权平衡的方式确定自动化控制参数,采用PID控制和闭环模糊控制方法实现掘进机自动化截割控制。实验结果表明,该方法横向控制和纵向控制都表现出较好的性能,掘进机截割头摆速在2 s内达到稳定值,动态工作稳定性好;悬臂式掘进机截割头回转和升降角度变化轨迹与期望轨迹之间的吻合度较高,整体偏离程度较小,控制精度较高。     

带有侧隙的行星齿轮传动动态特性研究

掘进机截割部减速器一般采用行星齿轮传动。掘进机工作时较大的载荷冲击会加剧截割部减速器齿轮的磨损,产生侧隙,从而影响齿轮的受力。本文运用力学原理建立了带有侧隙的行星齿轮传动的动力学方程,建立了三维模型,并在ADAMS中进行了动力学仿真,得到了行星齿轮传动的啮合力仿真曲线,揭示了啮合力的一些规律及其影响,得到了带有侧隙的ADAMS虚拟样机。同时,本文也为减速器箱体的虚拟样机分析提供了数据来源。     

数字孪生驱动掘进机远程自动截割控制技术

目前掘进机远程截割控制方法大多基于视频监控与平面信息,巷道断面成形质量取决于人工操作经验,可靠性较低。针对该问题,研究了数字孪生驱动掘进机远程自动截割控制技术,从数据感知、数据驱动、数据传输、远程自动截割控制等方面介绍了数字孪生驱动掘进机自动截割的实现过程。采用视觉测量技术获取掘进机位姿数据、气体传感器等获取掘进环境数据,构成数字孪生驱动的数据来源;建立掘进机虚拟模型和虚拟场景并完成虚拟模型动作编程及虚拟模型与虚拟场景的耦合,通过求解掘进机运动学正逆解,实现掘进机与虚拟模型交互;基于三次多项式方法进行巷道断面"S"形截割轨迹规划,设计反馈线性积分滑模控制器实现截割轨迹跟踪控制;采用MySQL数据库作为数据交互媒介,通过井下工业以太环网及矿用5G技术实现数据远程传输。实验结果表明,掘进机截割头能稳定跟随规划轨迹,且同一时刻虚拟界面显示的掘进机截割头位姿与实际位姿一致。     

纵轴式掘进机随机振动响应分析

为研究纵轴式掘进机在随机截割载荷作用下的随机振动特性,利用ADAMS软件建立了纵轴式掘进机多刚体动力学模型,利用该模型模拟了掘进机轴向钻进、垂直截割、水平截割工作方式下截割头、悬臂、机体的振动特征。仿真结果表明:轴向钻进工作方式对掘进机各部件的振动影响最大,且随机振动的纵向位移响应大于横向位移响应;垂直截割和水平截割时随机振动的横向和纵向位移响应相差不大,且水平截割对机体的振动影响最小。     

掘进机截割部振动特性分析与仿真

根据掘进机截割部的工作状态,在假设煤壁的单轴压缩强度恒定等条件下,建立了截割部的振动方程,利用ADAMS/Vibration振动模块对实体模型进行自由振动分析和强迫振动分析,得到系统各阶模态主振型、频率响应曲线等振动特性,为验证掘进机工作过程中的动力特性及掘进机结构优化的提供了依据。     

割岩截齿的应力分布及其载荷的仿真研究

针对掘进机截割岩石时截齿损坏严重、直接影响掘进机截割的经济效益和推广应用的实际,为了探究截齿损坏的原因,解决割岩截齿强度的问题,提出了一种考虑硬质合金头柔性体截齿割岩的分析方法,根据等向硬化理论、关联流动法则、能量耗散的破坏准则,建立了岩石及其截槽的三维模型和截齿的硬质合金头、齿体的三维模型,通过显式动力学分析模块ABAQUS/explicit,仿真得到了截齿及其齿体、硬质合金头的应力云图和截齿的截割阻力、牵引阻力和侧向阻力曲线.研究证明,齿体与合金头结合部的应力集中是产生合金头脱落的主要原因,幅值最大的截割阻力将导致截齿的磨损、折断,而波动最大的侧向阻力是引起截齿横向疲劳断裂的根本原因.实践证明,可为截齿的强度设计提供了科学依据.     

掘进机恒功率自适应调速与记忆截割系统研究

由于掘进机在进给过程中截割头工作面负载变化存在随机性且幅度很大,设计并开发一套以可编程序控制器为数据采集和控制核心,上位机采用组态软件构建远程监控系统的掘进机自适应控制系统,采用多信息融合技术综合分析负载的变化,实现恒功率自适应调速,同时采用记忆截割与自适应调节相结合的控制方法,在记忆截割的基础上根据反馈信号进行局部调节,更新记忆曲线,保证掘进机的恒功率进给,延长掘进机截割头的使用寿命.     

悬臂式掘进机截割臂互换性设计

针对现有掘进机多采用单一的横轴式或者纵轴式整机,对不同岩层掘进工作的适应能力差等问题,提出一种面向不同岩层的掘进机截割臂互换性设计方案。对纵、横轴式2种掘进机的结构特点与性能进行了对比分析;针对2种截割臂工作模式的特点,分别设计了相应的截割减速器。Solidworks仿真结果表明,与单一横轴式或者纵轴式掘进机相比,采用互换式截割臂结构可有效提高掘进机对不同岩层截割工作的适应能力,提高掘进效率,节省设备运输及使用成本。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

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。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

基于QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

基于AD9626的模拟信号采集存储卡设计

自然界的绝大部分信号都是以模拟的形式存在,因此模拟信号的采集转换存储在数字时代十分关键。文章讨论了在雷达信号处理领域基于AD9626的AD采集存储卡的设计原理、硬件结构和程序设计与芯片配置等问题,为今后相关领域的研究提供了可参考的方案。     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

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.     

A human-computer interface for non-computer specialists

The COM teleconferencing system was designed to be easy to use for both beginners and people with much computer experience. A number of design choices in organizing the human-computer interface were considered very carefully. These design problems are not unique for teleconferencing applications, but will appear in many other developments of human-computer interfaces for non-computer specialists. This report discusses naming conventions, menu format, user commands, help facility and the treatment of ‘type ahead’ from the users.