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。     

圆度仪的调平和圆柱度误差评定

从圆柱度误差的测量要求和圆柱度误差评定搜索算法两个方面研究了提高测量精度的方法。为了减小圆柱度误差测量中的工件倾斜误差,设计并分析了两点垂直布局的调平方法;根据工件轴线的方向余弦,计算得到了两点调整的高度值,克服了手动调整存在的问题,实现了工件快速精确调平并提高了工件圆柱度的测量精度。由于圆柱度误差评定是对满足最小条件的圆柱轴线的搜索,文中针对Nelder-Mead单纯形法的收敛精度依赖于初始解和收敛速度较慢,提出了拟牛顿法和Nelder-Mead单纯形法相结合的联合算法来实现全局最优解的快速准确搜索。对经典测试函数的Matlab仿真及实际测量数据的应用表明,该联合算法能有效地提高收敛速度和收敛精度,其收敛速度提高了50%,收敛精度提高了1倍,从而提高了工件圆柱度误差的测量精度。     

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.     

全自动测量轴圆度的V形法测量系统研究

为了寻找一种结构简单、精度高、造价较低而且能全自动地测量轴圆度的方法,本文根据一般V形法的实际应用及测量精度,对一般的V形法测量系统进行了全自动化研究.本文介绍了V形法的测量原理、数据处理方法、全自动V形法测量系统的研究以及主要单元部件的构成.通过计算机控制、直流伺服电机带动被测轴旋转、计数码盘计算被测轴转过的角度、测微头自动拾取测量数据、计算机计算并输出计算结果,能够实现全自动测量轴的圆度,测量精度可达到十纳米级.     

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.     

曲轴连杆颈圆度误差的测量与评定方法研究

曲轴轴颈圆度是评价曲轴合格性和加工精度的一项重要指标。针对曲轴综合测量过程中连杆轴颈沿主轴颈公转运动,导致连杆轴颈的检测数据无法直接用于圆度误差评定的问题,建立基于运动坐标系的圆度误差检测模型,实现了连杆轴颈检测数据转换处理。同时,深入分析用于圆度误差评定的3种最小二乘法的适用条件,结合采样数据的特点实现了连杆轴颈圆度误差的高精度检测。以某型号发动机曲轴为例进行大样本误差检测试验,并与最小区域评定结果进行对比,偏差在1μm以内。数据分析表明了所提出的曲轴连杆轴颈圆度误差检测方法理论上的正确性及工程实践的可行性。     

高精度影像测量系统中图像的超分辨率重建

为了提高影像测量系统的测量精度,研究了基于微位移错位的多幅图像超分辨重建技术.考虑制作成本和制作难度,提出了一种不苛求精确微位移的超分辨率重建技术.首先,获取随机微位移图像序列;然后,利用被测对象中易于实现高精度提取的特征点或采用模板衬底中的特征点计算出图像序列间的准确位移关系;最后,根据本文提出的数学模型重建出高分辨...     

A hybrid three-probe method for measuring the roundness error and the spindle error

The three-probe method is the most widely used technique for separating the artifact roundness error from the spindle error, with the superiority available for in situ measurement. For further improving the measurement accuracy of the three-probe method, in this paper, the harmonic measurement errors are investigated analytically and experimentally. To achieve this aim, firstly, according to the transfer matrices W(k), the harmonics are classified into two types: the suppressed harmonics with zero W(k) and the unsuppressed harmonics with no-zero W(k). Then, on one hand, through mathematical deduction, the formulation for determining the suppressed harmonics is derived; on the other hand, the measurement errors to the unsuppressed harmonics are experimentally acquired, and the experimental results demonstrate that the measurement errors to the unsuppressed harmonics are greatly related to the determinant of the transfer matrix |W(k)|, but not rigorously in inverse proportion to |W(k)|. Based on the conclusions drawn from the investigations, a hybrid three-probe method is constructed, where several conventional three-probe measurements are performed for optimizing individual harmonic coefficients. Experiments verify that the hybrid three-probe method is more robust to the error sources than the conventional method.     

Investigation of error separation for three dimensional profile rotary measuring system

High precision 3D profile rotary measuring systems for large diameter workpieces are urgently needed in precision engineering. Error separation is critical for improving the accuracy of the system. In order to obtain higher accuracy for 3D profile rotary measuring systems, the random and systematic errors are analyzed and separated in this paper. In the measuring system, roll and pitch caused by the probe tilt violate the Abbe principle. Roll is removed by using two probes and pitch is separated by the interferometer method. The radial run-out and the perpendicularity error between the probe and the spindle axis are compensated by a two-probe-two-step method carried out on a standard hemisphere artifact. As the form error of the artifact is mixed with the perpendicularity error, the least-squares method is applied to fit the hemisphere and work out the perpendicularity error and the profile error of the hemisphere. Finally, numerical validation is presented using Matlab program to demonstrate the effectiveness and correctness of the proposed method.     

高精度弹丸质偏心测试系统的设计

弹丸质偏心是弹丸性能的重要设计参数,它们的准确测量对于提高产品质量,提高发射准确性是必不可少的。为了提高其测量精度和效率,本文详细介绍了基于三点法的弹丸质偏心测量原理、计算公式和测量设备,分析了测量误差产生的因素,提出了一座多测试平台和自动调平以及弹体自动旋转90°的设计思想。给出的试验结果表明,这些方法极大地提高了系统的测量精度和试验效率,能够满足弹丸高精度质偏心测量的指标要求。该设备测量范围广、制造成本低,具有广泛的应用开发前景。     

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。     

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。     

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。     

Uncertainty evaluation and reduction in three-probe roundness profile measurement based on the system transfer function

The three-probe method for separating the spindle rotation error and the specimen form error is extensively described in the literature. An attractive feature is its application in in-process measurement. However, the resulting uncertainty is studied far less extensively. In this paper, an evaluation and propagation method for the uncertainty, as well as for an uncertainty reduction, is given based on the system transfer function (S-function). First, utilizing the Laplace transform, the measurement system model is developed and expressed by an S-function. Second, the propagation laws of input uncertainties are analytically deduced by computing the partial derivatives of the S-function of roundness. Then, the laws are numerically validated by Monte Carlo simulations. The uncertainty propagation laws show that the uncertainties propagate with varying amplification over the harmonic domain, and moreover, they enable the quantification of both the harmonic and the total uncertainty of roundness. Taking the roundness uncertainty as a decisive parameter, three approaches are proposed for uncertainty reduction: (1) the hybrid 3-PM, where two roundness estimates are combined by taking individual harmonic estimate with the lowest uncertainty, (2) the fusion 3-PM, where the weighted average is taken over the harmonic domain, and (3) the angle optimization, which minimizes the total roundness uncertainty by properly arranging the sensor angles. The angle optimization is applied to the conventional 3-PM, as well as to the hybrid and the fusion 3-PMs. The genetic algorithm is adopted to speed up the optimization process. Finally, practical roundness measurements are performed.     

凸轮升程误差在三坐标测量机上的精确测量

根据凸轮升程误差的设计要求与测量要求,提出了在三坐标测量机上用搜索点法实现的凸轮升程误差的测量方法,介绍了方法的原理、实现步骤,并对测量方法进行了误差分析。理论分析与测量实践表明,本文提出的凸轮升程误差测量方法的测量极限误差为±1.8 μm,比传统的凸轮升程误差测量方法如桃尖点法、敏感点法的测量极限误差小40%左右。