坐标测量机的溯源与校准规范

讨论了坐标测量机溯源的概念和方法,介绍了新制定的坐标测量机校准规范(报批稿),并与国家标准进行了比较     

Mapping and correction of the CMM workspace error with the use of an electronic gyroscope and neural networks—practical application

The article presents the application of neural networks in determining and correction of the deformation of a coordinate measuring machine (CMM) workspace. The information about the CMM errors is acquired using an ADXRS401 electronic gyroscope. A test device (PS‐20 module) was built and integrated with a commercial measurement system based on the SP25M passive scanning probe and with a PH10M module (Renishaw). The proposed solution was tested on a Kemco 600 CMM and on a DEA Global Clima CMM. In the former case, correction of the CMM errors was performed using the source code of WinIOS software owned by The Institute of Advanced Manufacturing Technology, Cracow, Poland and in the latter on an external PC. Optimum parameters of full and simplified mapping of a given layer of the CMM workspace were determined for practical applications. The proposed method can be employed for the interim check (ISO 10360–2 procedure) or to detect local CMM deformations, occurring when the CMM works at high scanning speeds (>20 mm/s). SCANNING 35: 222‐231, 2013. © 2012 Wiley Periodicals, Inc.     

On the calibration of surface plates

Calibration of large surface plates could be performed using different measuring systems. In this investigation an autocollimator system, a laser system and a coordinate measuring machine have been investigated. A comparison among these methods of calibration has been carried out. An Elcomat 3000 autocollimator of resolution 0.05 arcsecond, an Agilent 5529A laser interferometer system of resolution 0.05 arcsecond and a Prismo/Zeiss Computerized Numerically Controlled Coordinate Measuring Machine (CNC–CMM) respectively are used. Large reflecting mirror, angular retro reflector and sensitive probe are used with autocollimator, laser systems and CNC–CMM respectively to identify heights at each position on the tested surface plate. Repeated results from the different methods are carried out and presented in the paper. Uncertainties associated with the measurement results of each method have been estimated using the GUM procedures and given in the paper. The paper discusses the difficults and ease as well as accuracies associated with each method.     

半光斑成像式多功能激光瞄准测头的研究

运用半光斑成像原理设计了一种用于三坐标测量机的多功能激光瞄准测头。详细介绍了测头的光学系统工作原理和设计思路,采用自适应控制方法实时调节激光光强使其可以适应不同光学特性表面的瞄准测量,并进行了多功能测头的重复性瞄准测量、灵敏度测量、倾角跟踪实验。实验结果表明,该测头重复性瞄准测量不确定度优于1 μm,测量灵敏度可达30 mV/μm,激光跟踪瞄准被测曲面倾角可达25°,能满足三坐标测量机的使用要求。该测头具有检测速度快、自动化程度高、瞄准精度高的特点,结合三坐标测量机或者其它测长仪器,能够实现对自由曲面进行快速精确瞄准及轮廓图像瞄准测量,具有广泛的应用前景和实用价值。     

坐标测量机方位误差软件的算法研究

本文研究了坐标测量机应用软件中方位误差计算的算法，分析了要素的构成性质，定义边界和相互作用对计算方位误差的影响，提出了方位误差软件的标准与软件检定的概念。     

基于虚拟现实的坐标测量机动态图形建模方法

近几年发展起来的虚拟制造技术成为设计制造领域研究的热点,它对制造过程中的设计、加工、测量、装配和检验等提出了新的要求。由于坐标测量机是制造系统的重要组成部分,为了满足虚拟制造系统的要求,说明了虚拟现实环境中坐标测量机动态图形建模与仿真的必要性,并介绍了利用三维图形开发语言ＯｐｅｎＧＬ进行几何建模与现有其它几何建模方法的统一性和差别,以及用Ｏｐｅｎ在虚拟环境中进行坐标测量机动态图形建模的方法和过程,     

COORDINATE MEASURING MACHINE PROBING ACCESSIBILITY

0　ＩＮＴＲＯＤＵＣＴＩＯＮＣｏｏｒｄｉｎａｔｅｍｅａｓｕｒｉｎｇｍａｃｈｉｎｅ (ＣＭＭ )ｉｓｔｈｅｋｅｙｄｅｖｉｃｅｕｓｅｄｉｎｃｏｍｐｕｔｅｒ ｉｎｔｅｇｒａｔｅｄｄｉｍｅｎｓｉｏｎａｌｉｎｓｐｅｃｔｉｏｎ .Ｈｏｗｅｖｅｒ,ｆｒｏｍｔｈｅ ｐｅｒｓｅｃｔｉｖｅｏｆｆｕｎｃｔｉｏｎａｌｉｔｙ ,ｉｔｉｓｍｅｒｅｌｙａｎａｃｃｕｒａｔｅｄｉｇｉｔｉｚｅｒ ,ｒｅｑｕｉｒｉｎｇｌｅｎｇｔｈｙ ｐｌａｎｎｉｎｇ ,ｆｏｒｉｎｓｐｅｃｔｉｎｇｃｏｍｐｌｅｘｗｏｒｋｐｉｅｃｅｓ.Ｉｎ ａｎｉｎｓｐｅｃｔｉｏｎ ｐｌａ…     

Geometrical principles for analysing hypoidal gears in Coordinate Measuring Machines: Involutometry,protocols, data interpretation

The design of hypoidal gears has many degrees of freedom; some external such as eccentricity, diameters, surfaces of pitch; and others internal such as pressure angle, helix angle, or involute. All parameters are linked producing teeth which are continuously variable in their shape. Apart from indexing, Coordinate Measuring Machines are required for quality control, reverse engineering, analysis of faults, or for setting up manufacturing processes. To design measurement protocols with Coordinate Machines, it is necessary to define: involutometry, boundaries of teeth and paths for touching. To interpret the data from Coordinate Machines, mathematical tools are proposed as complementary to those proposed by previous authors in this field. Since couples of crown–pinion may differ from theoretical designs, it is necessary to define universal frames to aid the analysis of geometrical quality. Both mathematical tools and CAD tools are considered as part of the Coordinate Machines for these applications.     

The geometric dynamic errors of CMMs in fast scanning-probing

Quasi-stiffness model is effective for the compensation of the geometric errors of coordinates measuring machines (CMMs) in slow probing, but degrade the error compensation accuracy due to the generation of dynamic errors in fast probing. It is usually regarded that acceleration is the major origin of dynamic errors; and yet the dynamic effects that rise from the quick fluctuation of geometric errors in fast probing had attracted little attentions. This paper presents a model for the dynamic effects of the geometric errors of CMMs in fast probing, and investigates their properties with experiments. The error model is built with recursive least squares (RLS) identification technique by taking probing acceleration and the 6 geometric errors of X slideway for the inputs while the positioning error of probe tip for output. Then the positioning error of probe tip is decomposed into 7 components corresponding to the 7 inputs. Analyses on the experiments show that the angular errors around Y and Z axes, ε_Y(x) and ε_Z(x), can induce remarkable dynamic effects, especially in a CMM with low stiffness air bearing. Error compensation with RLS identification seems feasible theoretically, but it is not recommendable due to the veracity uncertainty of identification. Nevertheless smoothening the sharp corners of the curves of geometric errors, especially ε_Y ∼ x and ε_Z ∼ x, in terms of probing speed and Y coordinates of probe tip is considered as a simple but effective and reliable method to improve the accuracy of CMMs errors compensation in fast probing.     

坐标测量机测量齿轮形位偏差不确定度评估方法和实验

介绍了坐标测量机测量齿轮形位偏差不确定度的评估思路及计算方法，通过试验找出了坐标测量机测量齿轮参数的主要不确定度来源，并阐述了提高测量准确度的途径及如何确定被测齿轮的精度级别。