直线式箱体全自动无氟发泡线充注机械手的设计

介绍了直线式全自动箱体发泡线充注机械手的结构及其驱动系统,该系统可直接应用在新箱体发泡线的制造上,又可用在老箱体发泡线的改造上,因此具有极大的推广价值和显著的经济效益.     

铜线替代金线在晶体管封装中的压焊工艺研究

通过比较铜线与金线的性能,论述了铜线压焊的特点、设备的改造、铜线产品质量检验与常见不良产品等,在晶体管产量较大时,使用铜线压焊能有效地降低生产成本,因而在通用民品中有着非常广阔的应用前景.     

金亿机械有限公司:玉米收获机创造新纪录

11月18日,山东金亿机械制造有限公司在美丽的海滨城市日照举办了山东省玉米机械化发展与推广研讨会暨2008年商务年会.原计划600多人参加的会议却来了900多人,这在金亿公司是史无前例的,让公司领导及员工忙得不亦乐乎.金亿公司董事长马金英满面春风对记者说:"人气旺盛,一是得益于党的政策好,二是今年金亿公司拥有喜人的表现,小麦机产销1600台,市场占有率由去年的5%提升为15%,玉米机销售1200台,占行业内同类机型首位.同时,金亿产品也是获得政府补贴最多的产品."     

SIMATIC IT助力制造

西门子中国有限公司的业务结构涉及的行业和领域主要包括:信息通讯、自动化与控制、医疗、照明、能源、交通、金融和房地产等.西门子MES属于西门子自动化与驱动集团,这个业务集团是西门子最古老的集团之一,在中国的业务也发展非常好,产品覆盖各行业客户的自动化需求.自动化与驱动集团分为七个部门,MES隶属于其中的自动化与系统部.整个集团全球有近10万种产品,每个月约有18种新产品问世.自动化与驱动集团将其年销售额的约9%用于研发投资,尤其在工业软件方面很多人都认为自动化是一个硬件设备,但随着现在软件的发展,西门子也提供大量的软件开发.     

为推动国内实验室离心机行业升级而努力——专访上海安亭科学仪器厂董事长陆永泉先生

我国的实验室离心机产业近年来在研发生产方面取得了进步,但由于大部分企业的规模较小等原因,整体上与国外产品尚有一定差距。《中国仪器仪表》杂志记者专访了上海安亭科学仪器有限公司董事长陆永泉先生,陆先生评述了实验室离心机行业现状并提出了提高产品水平的措施,为推动国内实验室离心机行业升级提供了很好的建议。     

DSP+FPGA数据处理系统的研究与应用

针对铣削加工中心主轴刚度检测系统实时性的要求,重点阐述了DSP FPGA的数字硬件系统和流水线结构的CORDIC算法在FPGA中的实现,并通过仿真和实验对CORDIC算法的理论值和计算数值进行对比分析,结果表明,计算数值非常接近理论值.     

"数字化组织"迈出智能化敏捷制造第一步

PTC这支在船舶领域雄立多年的老牌劲旅,早在1992年就开始涉足船舶业,并取得了不错的成绩,1998年收购CV公司后更加强了其在船舶业的发展势头.目前在中国,军船市场一直占主导地位,民船虽然近几年才开始兴起,但市场表现也不俗.2007年我国的船舶业迎来了前所未有的井喷时期,也为PTC船舶业绩的提升带来了发展良机,而这一切早已洋溢在了PTC中国船舶业销售总监王慧杰的脸上.     

美国流体动力工程研究中心简介

本文简要介绍了美国国家流体动力工程中心的基本情况、研究方向和教学计划.在此基础上对我国流体动力传动与控制的科研单位和企业的发展提出了一些看法.     

颅骨解剖机械设备的研制

本文针对目前法医解剖人体颅骨用设备存在的问题,探讨研究一种科学实用的颅骨解剖专用设备,用以提高解剖人员的工作效率,提高解剖质量,改善工作环境.     

防雨、防暴晒、夜晚能自动收缩的智能晾衣架设计

智能晾衣架的机械部分是在普通拉杆式晾衣架两支撑杆的端部各安装一个滑轮,再穿入钢丝绳.钢丝绳与最前外面的晾衣杆固定连接.钢丝绳的另一端连接到与直流电动机相连的转轴上,通过电动机的正反转达到晾衣架的伸缩效果.其控制部分的电路CPU采用89C2051单片机.利用温度、雨水、光敏等传感器,达到下雨时自动收回,雨后自动伸展;气温高于设定值时自动收回,低于设定值时自动伸展;夜晚自动收回,白天自动伸展的功能.     

A CO2 tracer-gas method for local air leakage detection and characterization

A method for local measurement of air leakage rate is presented that can be used to accurately and quickly assess leakage rates across a surface, such as around a valve or hatch in a pressurized gas tank or a window in a building. The method uses a small local enclosure with constant volume placed about a region on the structure under investigation (e.g., a window), which is depressurized and injected with a small concentration of carbon dioxide as a tracer gas. The time variation of the pressure and carbon dioxide concentration inside the enclosure are monitored and used to quantify the leakage flow rate as a function of pressure difference. This method uses a small enclosure with internal mixing so that a quasi-steady-state condition is quickly achieved. Because of the small size of the enclosure, advanced data processing techniques are necessary to reduce uncertainty in determination of the rate of change of the carbon dioxide concentration that arises from sensor variability. Results of a laboratory demonstration of the proposed leakage detection and characterization device are reported for the problem of leakage through a circular hole in a plate with prescribed pressure differences. Experimental results from the laboratory tests are found to be in excellent agreement with results of a numerical simulation of leakage flow through a hole, as well as predictions from a number of empirical equations for this problem found in the literature.     

CMM Probing Accessibility in a Single Slot

This study presents a novel mathematical method for resolving the accessibility of a through slot when using coordinate measuring machines. The proposed method considers the actual shape of a probe consisting of a motor column, a stylus, and a probe tip. Also derived herein is a mathematical method to derive the feasible probe orientation of the measurement point in the bottom of a slot using a geometrical relationship between the probe and the slot.     

计算机辅助设计凸轮及其数控加工

介绍了如何利用计算机对于形状复杂和高精度的凸轮进行辅助设计,以及将设计结果直接在数控机床上加工的方法,分析了图解法设计的局限性和计算机辅助设计的优越性,指出了利用计算机辅助解析法设计是实现数控加工的基础,也是未来机械设计的发展方向。     

脉冲激光测距中高精度时间间隔测量方法的研究

高精度时间间隔测量对脉冲激光测距系统具有重要意义,为此提出了一种新的高精度时间间隔测量方法。该方法在FPGA中实现了脉冲计数法、多相采样法和延迟链法的结合。采用脉冲计数法对被测时间间隔进行“粗值”测量,保证大的动态测量范围。利用FPGA内部锁相环产生N路同频率,相位均匀分布的时钟信号作为计数时钟,基于等精度测频原理,将被测时间间隔的测时分辨率提高到Tclk/N。利用FlipFlop锁存器形成延时链,对被测信号与相邻计数时钟的时间间隔进一步量化。该方法解决了传统多相采样技术中倍频次数高则相移分辨率降低的问题,在不增加计数时钟和有限延迟链数量的前提下,得到较高测时分辨率。测试结果表明,该时间间隔测量模块不但可以实现大的动态测量范围,而且测时过程相对较短,具有较高测时精度。     

智能气体识别仪的研究

智能气体识别仪用以识别气体种类,它具有学习识别多种气体的功能。本文介绍了仪器的工作原理、特点及仪器的硬件和软件构成。     

基于XeF(C-A)放大器的混合(固态/气态)超高功率飞秒激光系统

提出了基于前端发生器和终端放大器,使用光泵浦XeF(C-A)激活介质的太瓦级混合激光器(THIA00)系统.前端发生器由长532 nm的连续激光泵浦的钛宝石飞秒脉冲振荡器,脉冲展宽机构,532 nm的脉冲激光泵浦的再生多通道放大器,衍射光栅压缩器和二次谐波发生器(KDP)组成.其光束输出参数为:脉冲持续时间50 fs,...     

Automated fixture configuration using projective geometry approach

The geometric and topological specification of a workpiece boundary is usually represented in a specific data format in a CAD database. To retrieve a set of workpiece data, to analyse its shape in addition to the machining requirements, and to determine the proper fixture configuration accordingly, are not trivial tasks when a part has a complicated shape. The real challenge is to recognise and synthesise the shape of a workpiece from its data representation. Consequently, the decision for fixturing can be made when the shape of a workpiece and the relationship of the shape and the fixturing configuration can be derived by a systematic methodology. In this paper, a projective spatial occupancy enumeration (PSOE) approach is applied as a representational and manipulating scheme for developing algorithms in automatic fixture configuration. The workpiece is projected onto the working plane of the fixture baseplate. A 2D projection is defined as a matrix of cells which can represent a workpiece with an arbitrary shape. Using a discrete search based upon the matrix of cells, the fixture types and their locations are generated according to a set of heuristic algorithms. This work is a generalisation and extension of previous works for prismatic parts. The same methodology is equally applicable in general robot grasping.     

An inverse shock response spectrum

The shock response spectrum (SRS) is a tool commonly used by application engineers that characterizes the severity of a transient acceleration. Due to the definition of the SRS, neither an analytical nor a unique inverse exists for an arbitrary function. An SRS presented without any temporal information makes creating a corresponding acceleration time history for an experimental or numerical study prohibitively difficult without a rigorous method to determine an inverse of the SRS (a corresponding time history). The present work develops a method to calculate an inverse of an arbitrary SRS using three sets of well characterized basis functions: an impulse function, a sine function/damped sine function, and a modified Morlet wavelet. These three basis functions are specifically chosen for the properties of their transformations: the impulse introduces a constant increase to the SRS above a given frequency, the sine wave introduces a narrow peak at a given frequency, and the Morlet wavelet introduces a plateau with an adjustable width and relative height. Using the definition of the SRS, the transformations of the basis functions are calculated and these expressions are used to derive a methodology for calculating an inverse SRS. The effectiveness of the method is demonstrated by several examples. The quality of an inverse SRS is evaluated by comparing the SRS of the inverse to the target SRS. This method is developed in order to provide a quick estimate of a corresponding time history; in applications where a higher fidelity representation of the SRS is needed than can be provided by the method developed, a genetic algorithm is used to optimize the coefficients of the basis functions. Given a sufficient number of basis functions for the optimization, the resulting SRS can almost exactly match a randomly generated target SRS that is nonzero over the frequency range considered. For applications in which the permissable basis functions are limited (such as for an experimental test apparatus), an extension of the genetic algorithm method is discussed.     

A method for detecting tool wear on a CNC lathe using a doppler radar detector

Installing a non-contact in-process tool wear detection system on a computer numerical control lathe can help prevent product defects and improve product quality without impacting product cycle time. Many methods have been proposed for non-contact in-process tool wear detection. In particular, a recent international patent application describes a method for measuring the torque in a rotating axle using a high-frequency wireless transmitter/receiver and a vibrating string. The method has reportedly been used to detect cutting on a manual lathe. The authors present a new method for measuring tool wear using a high-frequency wireless transmitter/receiver alone, without a vibrating string. The high-frequency transmitter/receiver apparently responds to metal-metal contact noise rather than, or more strongly than, to signals generated by a vibrating string. The findings could help bring automated tool wear monitoring systems closer to the level of performance needed for practical use in industry.     

Robust scene recognition using a GA and real-world raw-image

This paper presents a new concept of scene recognition by a genetic algorithm (GA), using the 2-D gray-scale image of a working space, termed here as raw-image, and a model shaping the 2-D top-surface of a target object. In fact here, the problem of object recognition in the raw-image is changed into an optimization problem of a model-based evaluation function. We make use in this research of a GA, as a search and optimization method. This GA employs a model-based fitness function as its objective function to perform the search of a target in the raw-image. In this research, three object models, namely a frame model, a surface model, and a surface-strips model are investigated in order to determine which one is the best for scene recognition in a noisy environment. Also, in order to appraise the recognition performance of each model, a comparative study is performed by analyzing the answers to the following criteria questions: sensitivity, reliability, and speed. The effectiveness of the method has been verified through experiments using real-world raw-images, and the method has shown its robustness of object recognition with the surface-strips model, in spite of the noises in the scene.