Study on Measuring Perpendicularity Based-On Non-Diffracting Beam as the References

2012 ◽  
Vol 586 ◽  
pp. 349-355
Author(s):  
Xin Bao Zhang ◽  
Kun Zhang ◽  
Hong Lu
Keyword(s):  
Coordinate Measuring Machine ◽  
Position Error ◽  
New Method ◽  
Straight Line ◽  
Pentagonal Prism ◽  
Measuring Machine ◽  
Working Distance

A new method for measuring perpendicularity is developed in this paper, in which the non-diffracting beam that illuminates a pentagonal prism to produce the vertical reference is used as the straight-line reference and CCD is used as the sensor to gauge the position error to the references. Three evaluation algorithms of the perpendicularity error are also given in the paper. And furthermore, perpendicularity of a Coordinate Measuring Machine was measured by this method, which is easy to be operated. The results and analysis indicate that its working distance can be more than 15m while the precision can be less than±5μm/m.

Measurement Method for the Symmetry Error of Double Keyway in a Wheel Hub Bore

2010 ◽  
Vol 139-141 ◽  
pp. 2087-2092
Author(s):  
Xiao Ming Zhao ◽  
Yun Feng
Keyword(s):  
Measurement Method ◽  
Geometric Analysis ◽  
Coordinate Measuring Machine ◽  
Position Error ◽  
Minimum Condition ◽  
Engineering Practice ◽  
Error Evaluation ◽  
Measurement Principle ◽  
Measuring Machine ◽  
Error Formulas

In this paper, a new measurement method is presented, This method is to use a three-coordinate measuring machine (CMM) to test the symmetry error of double keyway in a wheel hub bore. According to the minimum condition criterion of form and position error evaluation, and making use of the minimum tolerance zone of position error evaluation, two symmetry error formulas of double keyway in a wheel hub bore are deduced by geometric analysis. The problems may be encountered when using the formulas in the practical application are discussed. These formulas solve the measurement principle problem of double keyway in the engineering practice. In the end an example is put forward to verify this method and the formulas.

Structure design and performance analysis of self-driving articulated arm coordinate measuring machine

2021 ◽  
Author(s):  
Hongtao Yang ◽  
Mei Shen ◽  
Mengyao Zhang ◽  
Jingjing Cheng ◽  
Tingting Hu ◽  
...  
Keyword(s):  
Performance Analysis ◽  
Angular Acceleration ◽  
Coordinate Measuring Machine ◽  
Position Error ◽  
Static Deformation ◽  
Theoretical Research ◽  
Positioning Error ◽  
Instantaneous Position ◽  
Measuring Machine ◽  
Space Range

Abstract To solve the problem that the traditional articulated arm coordinate measuring machine cannot measure automatically, a self-driven articulated arm coordinate measuring machine (AACMM) is proposed. The length of the connecting rods of the AACMM was allocated according to the design indicators. The AACMM virtual prototype was assembled based on the joint module selection and joint component design, and its measurement space range was also verified. The AACMM ideal measurement model was established based on MDH methodology. The static deformation of the structure and the influence of the dynamic flexible deformation on the positioning error of the probe of the measuring machine was analyzed, respectively. The results show that the measurement space range of the AACMM designed in this paper can meet the design index of the measuring radius. The probe position error caused by static deformation of the measuring machine after structural optimization was reduced by an order of magnitude. The positioning error of the probe caused by the dynamic deformation of the AACMM structure meets the positioning accuracy index. In the constant-speed touch measurement stage, the instantaneous position error of the probe changes linearly with time, and the optimal touch speed (6.6 mm/s, 6.4 mm/s) exists to minimize the probe positioning error. During the variable-speed approach stage, the influence of angular acceleration and velocity of each joint on the positioning error of the probe can be negligible when AACMM in the typical posture. In the extreme posture, , the inertial force of the measuring machine structure and the instantaneous position error of the probe are the smallest with the optimal joint angular acceleration ( ) and angular velocity ( ). The structural design and positioning error performance analysis of self-driving AACMM can provide a theoretical research foundation for subsequent trajectory planning and error compensation modeling.

A New Method of CMM Inspect Path Planning for Precision Generalized Helicoid

2010 ◽  
Vol 455 ◽  
pp. 458-461
Author(s):  
Wei Min Pan ◽  
Yong Jian Yu ◽  
J.S. Li ◽  
F. Xu
Keyword(s):  
Path Planning ◽  
Aerial Part ◽  
Power Transmission ◽  
Coordinate Measuring Machine ◽  
Measuring Method ◽  
New Method ◽  
Measuring Process ◽  
Measuring Machine

The helical surfaces are widely applied to both power transmission and fluid compression or pumping. Helicoid is measured by digitized measurement with the coordinate measuring machine (CMM) in this paper. A numerical measuring method which is different from traditional measuring method for Helicoid is given. The Measuring process is illustrated in detail. At the same time, this method is proved effectiveness through a practical measuring example of an aerial part.

An exact method for the sphericity measurement of soccer balls

2003 ◽  
Vol 217 (5) ◽  
pp. 715-719 ◽  
Author(s):  
P J Neilson ◽  
R Jones
Keyword(s):  
Three Dimensional ◽  
Computer Software ◽  
Coordinate Measuring Machine ◽  
Current Method ◽  
New Method ◽  
Ball Surface ◽  
Ball Diameter ◽  
Sphere Approximation ◽  
Measuring Machine ◽  
A New Technique

The most popular games in the world are ball sports. Generally, ball properties such as weight, circumference and sphericity are specified in the rules and determine the ball quality. The current method of sphericity measurement employed by the Federation International Football Association (FIFA) is to measure the ball diameter at 16 points and then calculate the mean average. The sphericity of the ball is inferred from the diametric measurements. Unfortunately, diameter measurement does not guarantee sphericity, and a new technique has been developed to measure ball sphericity using a coordinate measuring machine (CMM). In this method a representative sample of the ball surface is probed/measured to give three-dimensional coordinates of defined points, nominally the ball panel centres. Computer software is then used to fit a least-squares sphere approximation to the ball data, giving a unique value for ball sphericity. Measurements were taken of six different brand type balls, with a sample of four balls of each brand; all balls were inflated to the same pressure. The results show that the new method of sphericity measurement suggested here gives a unique assessment of sphericity. The errors obtained from the new method are such that the FIFA error specification may need reconsideration.

New Method Based on Improved Double Ball Bar for Measuring Geometric Motion Errors of Coordinate Measuring Machine

2018 ◽  
Vol 12 (2) ◽  
pp. 199-205
Author(s):  
Ping Yang ◽  
◽  
Yue Wu ◽  
Hui Yu ◽  
Yinbiao Guo
Keyword(s):  
Rotation Angle ◽  
Coordinate Measuring Machine ◽  
Influential Factors ◽  
New Method ◽  
Separation Algorithm ◽  
Double Ball Bar ◽  
Ball Bar ◽  
Measuring Machine ◽  
The Difference ◽  
Geometric Motion

In this paper, an optimized method of measuring the geometric motion errors of a coordinate measuring machine (CMM) is proposed. The method is based on an improved double ball bar (DBB) that acquires the motion and link errors of the CMM and its actual rotation angles through simultaneous circular tests. The improved DBB has embedded a ring encoder system to the bottom of a commercial DBB on an auxiliary platform. In addition, an improved motion and link error separation algorithm is established by considering the difference angle Δθ between the actual rotation angle and the theoretical rotation angle of the DBB. Both influential factors of the center offset of the DBB and Δθ are discussed through simulations. When geometric motion errors are compensated for and measured on a 400 mm × 400 mm × 150 mm CMM, the standard deviations of the roundness errors decrease to 1.9 μm and 1.5 μm on the XY and ZX planes, respectively.

scholarly journals APPLICATION OF RULED SURFACES IN FREEFORM AND GEAR METROLOGY

2021 ◽  
Vol 61 (SI) ◽  
pp. 99-109
Author(s):  
Ivana Linkeová ◽  
Vít Zelený
Keyword(s):  
Coordinate Measuring Machine ◽  
Ruled Surfaces ◽  
Optical Scanning ◽  
Mathematical Properties ◽  
Straight Line ◽  
Tangent Surface ◽  
Cad Models ◽  
Measuring Machine ◽  
Point To Point ◽  
Cylindrical Helix

An application of two ruled surfaces (i.e., surfaces generated by a motion of a straight line), a surface of hyperbolic paraboloid and a tangent surface of a cylindrical helix in freeform and gear metrology is introduced in this paper. Both surfaces have been implemented as the main functional figures in several artefacts – metrological calibration standards intended for testing the freeform capabilities of various measuring technologies (e.g., tactile point-to-point measurement and tactile scanning on coordinate measuring machine, optical scanning, computer tomography). Geometrical and mathematical properties of the surface used are summarised, CAD models of all the developed standards are presented and photos of the manufactured standards are shown.

scholarly journals Coordinate Measuring Machine Probes Effect during Inner Thread Position Measurement

Proceedings ◽  
2020 ◽  
Vol 63 (1) ◽  
pp. 55
Author(s):  
Ferencz Peti ◽  
Petru Serban
Keyword(s):  
Coordinate Measuring Machine ◽  
New Method ◽  
Coordinate Measuring Machines ◽  
Position Measurement ◽  
Measurement Strategy ◽  
Accuracy Of Measurements ◽  
Measuring Machine

Starting from the idea of improving Coordinate Measuring Machines’ (CMM) measurement strategy for inner thread locations, we developed a new method which increases the accuracy of measurements and takes us closer to the pitch diameter. This article will analyze this new method by testing different touching probes configurations for different thread sizes. The objective is to identify the best probe configuration to be used in the measurements of different inner thread sizes.

Study on the Measuring Space of Flexible Arm Coordinate Measuring Machines

2012 ◽  
Vol 500 ◽  
pp. 283-286
Author(s):  
Guan Bin Gao ◽  
Wen Wang
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Kinematic Model ◽  
Coordinate Measuring Machine ◽  
New Method ◽  
Joint Angles ◽  
Flexible Arm ◽  
Important Measure ◽  
Measuring Machine ◽  
Measuring Space

The measuring space is the set of positions a flexible arm coordinate measuring machine (FACMM) can reach, and it is an important measure for the evaluation of a FACMM. To study the measuring space of FACMMs the kinematic model was established. Furthermore, a new method based on Monte Carlo method to calculate the measuring space of FACMMs was proposed. The method generates the data of joint angles with Monte Carlo method, which is used to calculate the coordinates of the FACMM’s probe through the kinematic model. These coordinates make up the measuring space. The results of the analysis on the measuring space show that the measuring space of FACMMs is not a sphere usually considered as but an ellipsoid, and there is lack of flexibility near the border of the measuring space.

scholarly journals Selection of the Best Model of Distribution of Measurement Points in Contact Coordinate Measurements of Free-Form Surfaces of Products

Sensors ◽  
2019 ◽  
Vol 19 (24) ◽  
pp. 5346 ◽  
Author(s):  
Marek Magdziak
Keyword(s):  
Coordinate Measuring Machine ◽  
New Method ◽  
Free Form ◽  
Experimental Investigations ◽  
Accuracy Of Measurements ◽  
Measuring Machine ◽  
Coordinate Measurements ◽  
Free Form Surface ◽  
Free Form Surfaces ◽  
Selection Of

The article presents a new method for determining the distribution of measurement points, which can be used in the case of contact coordinate measurements of curvilinear surfaces of products. The developed method is based on multi-criteria decision analysis. In the case of the new method, the selection of the distribution of measurement points on free-form surfaces is carried out based on the analysis of five different criteria. The selection of the best model of the distribution of measurement points results from the accuracy of coordinate measurements, the time needed to complete measurement tasks, the number of measurement points, the accuracy of the substitute surface representing the measured free-form surface and the area where measurement points are located. The purpose of using the developed method of the distribution of measurement points is to increase the performance of coordinate measurements primarily by increasing the automation of strategy planning of measurements of curvilinear surfaces and improving the accuracy of measurements of free-form surfaces of products. The new method takes into account various aspects of coordinate measurements to determine the final model of the distribution of measurement points on measured surfaces of products, thereby increasing the probability of the proper determination (i.e., identifying the highest deviations of a product) of the location of measurement points on the surfaces of a measured object. The paper presents an example of the application of the created method, which concerns the selection of the best model of the distribution of measurement points on a selected free-form surface. This example is based on, among others, the results of experimental investigations, which were carried out by using the ACCURA II coordinate measuring machine equipped with the VAST XXT measuring probe and the Calypso measurement software. The results of investigations indicate a significant reduction in time of coordinate measurements of products when using the new method for determining the distribution of measurement points. However, shortening the time of coordinate measurements does not reduce their accuracy.

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