OMNI Sip三维万向测头

测头是坐标测量机的关键部件，直接关系到测量机的工作效率和测量精度。坐标测量机测头按测量方式可分为接触式和非接触式两大类。接触式测头又可分为机械式、电气式和光电式；非接触式测头则包括光学显微镜测头和电视扫描测头等。本文介绍的瑞士Sip公司生产的OMNISip三维万向测头属于接触式光电测头。一、工作原理OMNISip三维万向测头（见图1）可在空间以任一方向进行探测。测头的设计遵循了以下计量原则：①测头无内部摩擦；②对探测方向无限制；③无非线性轴向运动。测头本身就可看作是一台微型测量机。测头内有一个可向任意方向运…     

加工中心测头的校正

在加工中心上加工工件时,测量刀具直径、长度以及确定工件零点坐标等需占用大量辅助工时,缩短这部分辅助工时对生产效率的提高具有重要意义。为此,我厂在引进辛辛那提公司四轴加工中心的同时,选购了雷尼绍(Ｒｅｎｉｓｈａｗ)公司的ＴＳ27Ｒ型刀具测头和ＭＰ12型主轴测头。刀具测头可快速测量刀具的长度和直径,并将测量值自动输入机床控制系统的刀具表中。主轴测头可准确测量工件表面位置坐标、外角和内角点位置坐标、圆柱中心线、两平行平面的中心面位置坐标,并建立工件零点与程序零点的对应关系。这两种测头操作简便,测量准确。但因两种测…     

在"万工显"上模拟从动件(测头)形状测量圆盘凸轮的方法

1测量原理与方法构思 如果把凸轮的转角-升程,用测头与凸轮轮廓型线接触点的坐标表示,只要准确求出以凸轮回转中心O为原点直角坐标系XOY中,测头与凸轮接触点的坐标值x、y,即可在"万工显"上实现模拟直动对心式刀口测头、滚柱测头和平面测头,进行圆盘凸轮升程的精密测量.     

改进型卡尺

改进前的情况用卡尺测量外圆，常会遇到以下情况而难以直接测量：①被测直径大于卡尺量程；②卡尺的测爪不能到达被测直径处；③被测外圆不完整（不足半圆）。改进后的情况如果对卡尺作一简单的改进，即能使它便利地适用于上述情况而不必进行烦琐的换算。其措施如下：①按附图所示制备一对测头，其内孔是为精磨外圆时装芯轴而设，孔径可按芯轴自定，切口宽度按卡尺的测爪厚度，使测头卡在测爪上略紧即可（如切口过宽，可用钳夹或锤击使其适度收口变形，直至能卡紧测爪）。测头材料可用４５号钢经调质处理（２８９～３２１HB）。②将测头装…     

非接触式曲面测头设计及精度试验研究

针对激光测头因测量范围小难以满足大量程自由曲面的高精度测量要求的问题,基于伺服运动控制技术,集成激光测头和光栅尺研制了一种非接触式测头。控制激光测头工作在线性度误差较小的中心范围内、而采用光栅尺反馈实现大范围的测量,详细介绍了系统的硬件及软件设计。试验数据处理结果表明,与激光测头相比,研制的非接触式测头测量范围扩大了1倍,而测量不确定度、修正值、线性度等精度指标并没有下降。     

基于多色集合的三坐标测头规划方法研究

为了提高三坐标测量中测头选择的智能化和测头可达性分析的效率,提出了基于多色集合理论的测头规划方法。针对不同的被测几何要素,制定了测头"可达性判定规则";利用色多集合理论建立了测头选择与测头可达性分析相关模型,给出了基于多色集合的"测头规划算法";实现了测头类型的选择及测头角度的确定。经实例验证,表明该方法可靠、有效。     

加工中心上刀具测头和主轴测头的校正

在使用加工中心加工工件的过程中,测量刀具的直径和长度以及确定工件零点的坐标占用了大部分的辅助时间。如何尽量缩短这部分时间,对提高生产效率有很重要的意义。为此,我厂在引进辛米公司四轴加工中心的同时,选购了雷尼绍{Renishaw)公司的TR27R型刀具测头(Tool Setting Probe)和MP12型主轴测头(spindle Probe)。其中刀具测头可以快速地测出     

高精度三维螺纹测量机接触式扫描测头动态特性研究

扫描测头是高精度三维螺纹综合测量机的核心部件,其动态特性严重影响了整机的精度.为了提高测量机的精度,对高精度螺纹三维尺寸测量线性扫描测头的动态特性进行了研究.首先分析了三维螺纹综合测量机用扫描测头的测量原理,然后建立了动态特性模型并提出了影响动态测量结果的因素,最后通过实验验证了这种测头结构的动态特性和测量处理方式的有...     

超硬气动测量头的机械加工

图1、图2所示的气动内外径测头与浮标式气动量仪配套使用,广泛应用于机械行业,进行孔、轴、槽等的尺寸测量以及形位误差的测量。目前使用的气动测头硬度在HRC62～65之间。但是,在如此高限硬度下,测头的使用寿命仍然很低,一般约为8000～10000次。例如,油泵油嘴偶件测头,连续使用不到一星期就因磨损而报废。     

Renishaw新型坐标测量机用经济型测座

世界领先的坐标测量机传感技术供应商Renishaw推出了RTP20(“绕杆式”)测座。它是一种独创的配有集成测头传感器的经济型测座,具有机动测座系统的功能及优点。它基于Renishaw现有的MH20i测座,能够进行以15度为增量的自动重复定位,配用集成的TP20触发式测头,为自动坐标测量机提供了一个灵活的触发测头系统,将显著提高测量能力。新型RTP20测座允许集成的测头利用A轴和B轴以15度为增量移动,具有168个可重复定位的空间位置,只需对每一测尖位置进行一次标定即可。由此避免了昂贵、费时的重新标定程序,从而确保了快速的零件检测能力。因此用…     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

Limits of topographic measurement by the scanning tunnelling and atomic force microscopes

Parameters describing the topographic character of a surface (height, surface wavelength, slope and curvature) can be derived from equivalent sinusoidal profiles. The response of a surface-measuring instrument may be modelled in terms of instrument parameters such as stylus radius, and scanning range and resolution. The performance of the instrument may then be mapped as a zone in amplitude-wavelength (AW) space to show the sinusoidal profiles it is capable of measuring. In a first-order analysis the STM and AFM are considered as equivalent to contact-stylus instruments with a notional stylus radius equal to the tip radius plus the gap. Comparisons between different instruments and types of instrument are readily made by mapping in AW space. The error arising from convolution of the sinusoidal profile with that of the finite tip may be quantified and plotted as contours in AW space.     

Fractional order nonsingular terminal sliding mode control for flexible spacecraft attitude tracking

This paper investigates a fractional terminal sliding mode control for flexible spacecraft attitude tracking in the presence of inertia uncertainties and extern...     

奥氏体不锈钢表面双辉等离子渗锆的动力学

利用双辉等离子渗金属技术在0Cr18Ni9Ti奥氏体不锈钢表面制备了一层均匀、致密、呈良好冶金结合的渗锆合金层,并对1 060℃下的渗锆动力学进行了研究。结果表明:随着距锆合金层表面距离的增加,锆元素的含量呈梯度递减,扩散系数逐渐减小,而扩散激活能逐步增大;在1 060℃采用双辉等离子技术渗锆时,渗锆合金层表层的空位密度为2.945×(1012~1013)cm-2,与相同温度下采用常规渗金属工艺相比,提高了1~2个数量级。     

气化炉三维扫描测量与数据处理

以德士古气化炉耐火砖的内壁蚀损检测设备为基础,对采集到的点云数据做了进一步处理.通过对数据的筛选和剔除,实现了数据点的平滑降噪细化和精简.然后利用点云对整、网格划分和分色显示等方法,最终完成了内壁腐蚀情况的三维建模.重点讨论了点云数据的预处理及后处理的方法,并根据内壁耐火砖的腐蚀阈值,提出了一种气化炉内壁腐蚀区域的识别与分割方法.对耐火砖的腐蚀分析、气化炉的生产与维修提供了可靠依据,并在工程应用中获得了一致认可.