一种圆度仪辅助测量工装的设计

转台式圆度仪是一种用于测量圆度、圆柱度、同轴度等参数的仪器。传统的使用圆度仪测量半径的方法由于操作繁琐、定位精度低,已不适用于大批量生产检测。提出了一种新的测量工装,具有结构简单、使用方便等特点。实践证明,使用新的工装辅助圆度仪进行内孔半径的测试,可以对工件进行较精确的定位,充分发挥圆度仪的精准性,有效避免了因定位误差导致需要重新调整工件位置的困扰,显著提高测量定位精度及工作效率。     

A new strategy for inspecting roundness features

This article addresses the problem of inspection of roundness error (in contrast to the measurement of roundness error) and the idea of GO-NOGO inspection software. A new approach is presented in which the formalism of linear programming is applied through reexpressing the initial geometrical problem and adding further constraints. The ultimate position is to provide a set of constraints from which the required inspection information can be obtained by examining only the feasibility of the mathematical progrma, with no need to consider its iteration toward optimality. Feasibility may be explored using an existing, although not widely known, algorithm to guide the GO-NOG decision. The basis of the algorithm is given along with practical examples of how it works, Tests indicate that on real data it usually involves a computational effort only modestly higher than using an exchange algorithm to find an optimal fit. Thus, it appears quite practical for applications to the relatively small computer of a standard instrument.     

High-accuracy roundness measurement by a new error separation method

This paper presents a new error separation method for accurate roundness measurement called the orthogonal mixed method. This method uses the information of one displacement probe and one angle probe to separate roundness error from spindle error. This method was developed from the mixed method, which uses the information of two displacement probes and one angle probe to carry out the error separation. In the present paper, the relationship between the characteristics of the mixed method and the probe arrangement is analyzed. Well-balanced harmonic response of the mixed method is verified to be obtainable for the case where the angular distance between the displacement probe and the angle probe is set at 90°. This orthogonal mixed method also had the simplest probe arrangement, because it requires only one displacement probe and one angle probe to realize the error separation. Optical probes were used to construct an experimental measurement system that employs the orthogonal mixed method. The displacement probe and the angle probe both use the principle of the critical angle method of total reflection, and they have stabilities of 1 nm and 0.01 in., respectively. The measurement results show that roundness measurement can be performed with a repeatability on the order of several nanometers.     

多步法圆度误差分离的演化形式及其谐波抑制分析

论述了多步法圆度误差分离技术原理,并通过测量次数、向量权函数的不同选择演化出了等转角多步法、两步法、反转法及不等角两次转位法,并对其逐一进行了谐波抑制分析.     

A new multiprobe method of roundness measurements

This paper presents a new multiprobe method for roundness measurements called the mixed method. In this method, displacements at two points on a cylindrical workpiece and an angle at one of the two points are simultaneously monitored by two probes. The differential output of the probes cancels the effect of the spindle error, and deconvolving the differential data yields the correct roundness error. The mixed method is compared to the traditional 3-point method with respect to the transfer function and resolution. Unlike the 3-point method, the mixed method can completely separate the roundness error and the spindle error, and can measure high-frequency components regardless of the probe distance. Resolution can also be improved throughout the entire frequency domain by increasing angular separation of the probes. An optical sensor specifically suited to the mixed method is designed and used to make roundness measurements. A fiber coupler and single-mode fibers are used in the sensor to divide a light beam from a laser diode into two beams, resulting in a compact sensor with good thermal drift characteristics. The displacement meter of the sensor is based on the imaging system principle and has a resolution of 0.1 μm. The angle meter is based on the principle of autocollimation and has a resolution of 0.5 in. A measurement system is constructed to realize measurements of roundness by using the optical sensor. Experimental results confirming the effectiveness of the mixed method for roundness measurements are also presented in this paper.     

用虚拟仪器改造YD200A型圆度仪

对传统的YD200A型圆度仪进行了虚拟改造的可行性分析,给出了基于PCI总线的虚拟仪器系统的软硬件构成。用设计的虚拟仪器对轴的圆度误差进行了实际测量,结果表明与传统的仪器及其测量方法、数据处理方式相比,虚拟仪器构建非常容易,还实现了检测过程的自动化、数字化、智能化及可视化,大幅度提高了测量速度、数据处理速度及测量精度。     

基于误差分离技术的圆度误差在位测量

总结了现有用于在位圆度误差测量的误差分离技术,并对经典频域三点法、时域三点法、频域三点法的近似实现方法和频域三点法的改进实现方法的测量特点进行了评述。针对球度误差没有实现在位测量的问题,将圆度误差分离技术引伸到球度误差分离技术,并在理论上进行了探讨。     

基于MATLAB的提高测量仪器精度方法研究

针对学生使用的形位公差测量仪器原始误差大、测量精度不高等现状,提出一种基于MATLAB曲面拟合提高测量精度的方法,并给出了具体的数学模型。实验中采用前后对照的实验方法,对同一工件同一位置直线度误差测量,直线度误差值由原来的66.75μm变成34.33μm,精度提高48.6%。实践证明:此方法可以有效减小测量仪器原始误差,并且可以为其他测量仪器消除原始误差提供借鉴。     

低成本大范围测温系统

本文介绍了一种由无距离测温探头，巡测仪及ＰＣ／３８６微机机组成的大面积测温系统。它成本低、测点多、测量覆盖面积大，具有很高的性能价格比。     

基于多体系统运动学理论的坐标测量机误差自动建模

研究分析了运用多体系统运动学理论对复杂机械如坐标测量机进行误差建模的基本原理,介绍了误差自动建模过程。以FXYZ型立式三坐标测量机为例进行了误差建模,给出了空间误差模型具体数学表达式。理论分析和实际应用显示所述方法很好地解决了误差建模的通用性问题,为精度分析和误差补偿等提供了一个理想的误差建模方式。     

经济型大尺寸激光自动坐标测量系统

利用手持式激光测距仪和二轴转台,设计了一种经济型大尺寸激光三维自动测量系统,用于船舶等大型工件的现场测量.介绍了系统的测量原理和主要组成部分,系统无需合作目标,在计算机的控制下自动对目标进行测量来获得相对系统的三维坐标数据.分析了系统的主要误差对测量结果的影响,完成了主要误差的提取实验.最后,利用激光跟踪仪对系统测试水平两点间的距离的测量精度进行了评定,并对船分段模型进行了测量实验.实验表明,该系统对水平放置物体的两点间距离的测量精度达到了1.73 mm,对船分段模型的平行平面之间的距离测量精度达到了1.5 mm.由于系统构成简单,硬件成本较低,测量精度较高,测量速度大约为1 point/s,非常适用于船分段的测量.     

Optical deflection measuring system

A system for accurate real-time measurement of deflections was developed. A stable laser source is, by means of a single-mode fiber, coupled to an optical head located at one end of deformed structure. A detector circuit with a quadrant detector and processing electronics, located at the other end of the structure, communicates the resolved 2D position of the incident beam over a common digital bus. Experiments using interferometers were conducted in a climate-controlled chamber to evaluate system performance and verify the accuracy. A resolution of 0.1  m is attainable in dynamic measurements. The system was calibrated and tested to yield measurement accuracy of ± 0.8  m for ± 2σ probability over the measurement range of ± 300  m. Drift of the system in the experimental setup was determined to be less than 2  m for measurement in both degrees of freedom within the 10 h period under constant environmental conditions.     

ICA不确定性问题在圆度误差分离中的解决措施

独立分量分析方法(Independentcomponentanalysis,简称ICA)在国内尚属一门新型的方法。文章介绍了ICA的无噪声模型、原理、预处理、非高斯性量度以及快速定点算法,重点讨论了ICA的不确定性在圆度误差分离中的处理方法。仿真结果表明,基于独立分量分析的圆度误差分离技术比传统的频域法和时域法更简单、实用、高效,同时由ICA分离出的信号不确定性问题得到了很好的解决。     

转位三步法矩阵算法

根据实际测量工况,研究一种适合圆度误差在位检测的转位三步法矩阵算法。详细研究该算法的推导过程及回转误差分离原理,给出完整的数学公式;工件轮廓一阶谐波分量的分离以及回转误差分离后工件圆轮廓重构等问题,最后应用C语言和matlab软件对矩阵算法的回转误差分离效果进行仿真分析;搭建实验台验证算法在实际使用中的可行性与正确性。实验分析表明:通过转位三步法的矩阵算法可以实现圆度误差与回转轴误差的分离,得到高精度的工件圆轮廓,提高圆度误差测量精度。此算法具有较高的使用价值。     

用反向法测轴系回转误差

阐述了用反向法对高精度轴系回转误差测试的过程及测试的一些结果。对轴系各种测试方法作了简单介绍,重点介绍了“二元光学元件激光直接写入设备”轴系回转误差的测试过程。测得轴系的回转误差为0.018μm。对反向法测试原理、误差分离的数学方法及实际应用,进行了描述。总结了影响测量结果重复性的几个因素。测试结果证明,此方法简单实用、结果准确,适合于精密机械设计人员使用。     

High accuracy error separation technique for on-machine measuring straightness

A novel time-domain method, which can reconstruct straightness profile of workpiece exactly for on-machine measurement, has successfully been developed. The proposed method is based on difference measurement and can use two or three displacement probes. It possesses the following characteristics: (i) adapting to long or short workpiece, (ii) assuming no prior knowledge, (iii) employing large shears, (iv) needing no accurate zero-adjustment of probes, and (v) reconstructing various surfaces including smooth, non-smooth, periodic, and non-periodic profile with no theoretical error. The theoretical analysis and simulation justify the effectiveness of this method. Finally, the measurement system consisting of an autocollimator and two non-contact capacitive probes is built and evaluated experimentally on a diamond turning machine. This system can remove both pitching and translational error motion of the scanning stage.     

A Hole-Plate Artifact Design for the Volumetric Error Calibration of CMM

To measure the volumetric error of coordinate measuring machines (CMMs), a hole-plate artifact method was studied. Example designs of the hole-plate are shown using titanium and ceramic materials. The deflection by its own weight of the designed hole-plate is analysed using the finite element method. The hole distances moved by the deflection are shown in different hole-plate set-up cases, for vertical and horizontal positions. The influence of inside hole roundness as a measuring standard is also studied. Eccentric errors for different hole roundness are simulated. The hole-plate set-up errors are also discussed. A method for obtaining the parametric errors of a CMM is shown using the hole-plate as a measuring artifact for CMM positioning error. In addition, a method for measuring 2D and 3D length errors using the hole-plate data is introduced.     

最大内接圆法内孔截面圆度误差评价与实现

针对内孔圆度误差的最大内接圆法评价,提出了一种基于最大弦线截交对称关系的评价模式。利用最大内接圆评价法的几何特征关系,在确定虚拟中心位置的基础上弦线截交模式可以快速搜索到最大内接圆圆心的位置,并且在评价中避免了计算搜索步长和搜索方向。分析表明:利用几何关系的弦线截交评价模式,达到了高效、精确评价内孔截面圆度误差的目的。可实现三坐标测量机及其它测量仪器利用坐标采样数据对内孔圆周截面形状进行最大内接圆法误差评价。     

钢管光电测长系统及误差分析

介绍了一种钢管光电测长系统及其测长原理,并对定长钢管重复50次测量所得数据进行了分析.结果证明,此测长方法可使测长精度达到±1 mm.     

基于最大内接圆法的圆度误差测量实现方法

介绍了一种在直角坐标系下利用最大内接圆法评价圆度误差的方法,建立了圆度测量模型。针对圆度误差最大内接圆评价,提出了一种最大内接圆心搜索方法,达到了快速、精确评价的目的,实现了在直角坐标系下三坐标测量机对圆度误差的最大内接圆法评价。