Inspecting Profile Errors of Conjugate Disk Cams With Coordinate Measurement

2008 ◽  
Vol 130 (1) ◽  
Author(s):  
Wen-Tung Chang ◽  
Long-Iong Wu ◽  
Kuang-Hua Fuh ◽  
Chen-Chou Lin
Keyword(s):  
Interpolation Method ◽  
Measurement Data ◽  
Coordinate Measuring Machine ◽  
Coordinate Measurement ◽  
Numerical Interpolation ◽  
Radial Dimension ◽  
Cam Profile ◽  
Measuring Machine ◽  
Profile Errors ◽  
Coordinate Data

To inspect cam profile errors, a coordinate measuring machine (CMM) is frequently employed. The coordinate data of discrete points at the cam surface are measured by a CMM in order to further evaluate the actual cam profile with complicated interpolation algorithms, and then the cam contour approximated by these algorithms may be compared with the theoretical one. In this paper, a direct and simple analytical method, instead of a numerical interpolation algorithm, is proposed for inspecting the profile deviations of conjugate disk cams with coordinate measurement data. The method is based on the derived correlation between the radial-dimension errors and the normal-direction errors of conjugate cam profiles. To verify the proposed method, an experiment of inspecting a pair of conjugate disk cam profiles was conducted. The experimental results obtained from the proposed method were compared with those obtained by using the Hermite interpolation method. It shows that this method is accurate and more efficient for inspecting the profile errors of conjugate disk cams.

A Simplified Method for Examining Profile Deviations of Conjugate Disk Cams

2008 ◽  
Vol 130 (5) ◽  
Author(s):  
Wen-Tung Chang ◽  
Long-Iong Wu
Keyword(s):  
Analytical Approach ◽  
Coordinate Measuring Machine ◽  
Measuring Instrument ◽  
Angle Variation ◽  
Cam Mechanism ◽  
Simplified Method ◽  
Cam Profile ◽  
Measuring Machine ◽  
Profile Errors ◽  
Dial Indicator

The profile errors of conjugate disk cams can be indirectly examined by means of measuring the conjugate condition of the assembled conjugate cam mechanism. This paper demonstrates how to measure the conjugate condition of the assembled conjugate cam mechanism to reveal the cam profile errors and also develops an analytical approach for relating the variation of the conjugate condition with the cam profile errors. For the machined conjugate cams with profile errors, if the subtending angle of the oscillating follower arms is intentionally changed to be variable, the variation of the subtending angle of the follower arms may indicate the variation of profile errors when the cams rotate. According to the magnitude of the subtending angle variation, the profile deviations of conjugate disk cams can be analyzed analytically. The profile errors of a pair of conjugate cams can be evaluated by means of the corresponding motion variation of the indicator reading. For such an examining method, the only required measuring instrument is a dial indicator. A pair of conjugate cams were examined by the method and also measured using a coordinate measuring machine to test the accuracy and efficiency of the method.

Determination of True Dimensional Quality and Build Errors Using Coordinate Measurement Data

1999 ◽  
Vol 121 (4) ◽  
pp. 749-755 ◽  
Author(s):  
R. J. Gu ◽  
G. C. Barber
Keyword(s):  
Measurement Data ◽  
Coordinate Measuring Machine ◽  
Coordinate Frame ◽  
Numerical Examples ◽  
Coordinate Measurement ◽  
Acceptable Quality ◽  
Measuring Machine ◽  
Material Points

For manufacturing personnel there exist two major tasks: determination of the quality of the build, and locating build errors if the quality is inferior. To serve this purpose a coordinate measuring machine is employed to determine the actual locations of designated material points. Depending on the measuring coordinate frame chosen, the initial raw data, unfortunately, do not impartially represent the true deviations of all the measurement points. This paper shows a technique to overcome this inevitable drawback embedded in the CMMs and determine if the build has acceptable quality under specified tolerances. Also presented in this paper is a method to quantify the quality of the measurement points for easy identification of build errors. Numerical examples are given to demonstrate the feasibility of the technique.

Evaluation of Actual Geometric Tolerances Using Coordinate Measuring Machine Data

1989 ◽  
Author(s):  
W. H. ElMaraghy ◽  
Z. Wu ◽  
H. A. ElMaraghy
Keyword(s):  
Three Dimensional ◽  
Measurement Data ◽  
Simulated Data ◽  
Coordinate Measuring Machine ◽  
Optimization Techniques ◽  
Test Cases ◽  
Tolerance Zone ◽  
Geometric Tolerances ◽  
Measuring Machine

Abstract This paper focuses on the development of a procedure and algorithms for the systematic comparison of geometric variations of measured features with their specified geometric tolerances. To automate the inspection of mechanical parts, it is necessary to analyze the measurement data captured by coordinate measuring machines (CMM) in order to detect out-of-tolerance conditions. A procedure for determining the geometric tolerances from the measured three dimensional coordinates on the surface of a cylindrical feature is presented. This procedure follows the definitions of the geometric tolerances used in the current Standards, and is capable of determining the value of each geometric tolerance from the composite 3-D data. The developed algorithms adopt the minimum tolerance zone criterion. Nonlinear numerical optimization techniques are used to fit the data to the minimum tolerance zone. Two test cases are given in the paper which demonstrate the successful determination of geometric tolerances from given simulated data.

scholarly journals A frame for a computer aided inspection planning system

2015 ◽  
Vol 4 (1) ◽  
pp. 125 ◽  
Author(s):  
Wilma Polini ◽  
Giovanni Moroni
Keyword(s):  
Measurement Techniques ◽  
Coordinate Measuring Machine ◽  
Planning System ◽  
Inspection Planning ◽  
Coordinate Measurement ◽  
Measurement Results ◽  
Measuring Machine ◽  
Set Up ◽  
Almost All ◽  
Computer Aided Inspection

Coordinate Measuring Machine (CMM) inspection planning is an activity performed by well-trained operators, but different measurement techniques, using the same data analysis algorithms yield in different measurement results. This is a well-recognized source of uncertainty in coordinate measurement. A CMM, provided with an automatic inspection planning (CAIP) system, permits to implement more accurate and efficient operating procedures and to fit higher quality assurance standards and tighter production timings.In this paper we present a frame of a CAIP system, able to deal with almost all the decisional stages of CMM inspection. Moreover, original approaches have been developed and presented in inspection feature selection, part set-up, probe configuration, and path planning.

scholarly journals Geometric analysis of injection-molded polymer gears (Rapid communication)

Polimery ◽  
2021 ◽  
Vol 66 (1) ◽  
pp. 56-62
Author(s):  
Jadwiga Pisula
Keyword(s):  
Geometric Analysis ◽  
Coordinate Measuring Machine ◽  
Accuracy Class ◽  
Coordinate Measurement ◽  
Gear Teeth ◽  
Single Tooth ◽  
Measurement Results ◽  
Measuring Machine ◽  
Injection Molded

Properties of polymer gears were tested using coordinate measurement methods. This study is a follow-up to research on geometric accuracy of gears manufactured by injection molding. Spur gears were measured on a coordinate measuring machine running the GINA software by Klingelnberg. Measurement results were output in the form of measurement sheets which included values required in the DIN 3962 standard. The article also analyses the topography of test gear teeth. The topography was presented for a single tooth of the gear and determined on the basis of the measurements of 9 profiles distributed evenly over a specific profile assessment interval (interval Lα defined in the standard) and 7 tooth traces located within a relevant tooth trace assessment interval (interval Lβ defined in the standard). All gears tested in this study were placed outside accuracy class 12.

Determining the surface form of polystyrene through the coordinate measurement machine

2003 ◽  
Vol 217 (7) ◽  
pp. 839-844 ◽  
Author(s):  
D Aitchison ◽  
R Sulaiman
Keyword(s):  
Food Packaging ◽  
Coordinate Measuring Machine ◽  
Medical Application ◽  
Surface Form ◽  
Daily Lives ◽  
Coordinate Measurement ◽  
Different Temperatures ◽  
Measuring Machine ◽  
Different Shapes ◽  
Drilling Rigs

The market for foam materials has been growing rapidly throughout the world as they have a variety of uses. Some examples are in the automotives industries, food packaging industries, medical application, sports gears, home insulations and floatation in offshore drilling rigs, buoys and small boats. Since the uses of foam affects greatly the daily lives of humans, the need to have foams in different shapes requires speed in cutting and manufacture. This can only be done through computer aided cutting machines or automated cutting of foams. However, the speed of cutting will affect the surface finish of the cut. Therefore, it is necessary to determine the surface form of the polystyrene to achieve quality results. This is an on-going research to produce a rapid-prototyping machine that cuts foam models. The first phase of this research is to determine the surface form of polystyrene through the use of a coordinate measuring machine (CMM), after being cut with different types of wires, at different temperatures and cutting feedrates.

Slicing: A Procedure for Tolerance Evaluation of Manufactured Parts Using CMM Measurement Data

1995 ◽  
Author(s):  
Yu Wang ◽  
Shilendra Gupta ◽  
Srinavas Rao
Keyword(s):  
Computational Complexity ◽  
Measurement Data ◽  
Coordinate Measuring Machine ◽  
Significant Loss ◽  
Processing Procedure ◽  
Machined Parts ◽  
Measuring Machine ◽  
Part Model

Abstract This paper presents a sampling and processing procedure for tolerance evaluation of machined parts. In this method, deviations of the measured points from their ideal feature surface are evaluated in the plane where the data is measured by a Coordinate Measuring Machine (CMM). This procedure is called slicing. It is shown that the use of the structure inherent in measurement data has a potential in reducing computational complexity for evaluation of certain types of form tolerances without significant loss of accuracy. An application of the proposed method to the development of manufactured part model for automotive spaceframe structures is also discussed.

A study on the key techniques of application of REVO five-axis system in non-orthogonal coordinate measuring machine

2016 ◽  
Vol 231 (4) ◽  
pp. 730-736 ◽  
Author(s):  
Haitao Zhang ◽  
Shugui Liu ◽  
Xinghua Li
Keyword(s):  
Mathematical Model ◽  
Measurement Data ◽  
Coordinate Measuring Machine ◽  
Coordinate Measuring Machines ◽  
Measurement Results ◽  
Measuring Machine ◽  
Key Techniques ◽  
Five Axis ◽  
The Mathematical Model ◽  
Body Theory

REVO five-axis system, designed for the orthogonal coordinate measuring machines, must be reconfigured for the application in the non-orthogonal coordinate measuring machines. First, in this article, error sources of the system and components of measurement data are analyzed; then, scale values of coordinate measuring machine axes, which are essential to derive the coordinates of measured points in non-orthogonal coordinate measuring machine, are separated out. Besides, the mathematical model of REVO is established based on the quasi-rigid body theory, from which the measurement results can be evaluated by data derived instead of that returned by the system. The effectiveness of both separation of scale values and mathematical model of REVO is proved by experiments and practice. The research of this article is of great significance to the application of REVO five-axis system in the non-orthogonal coordinate measuring machine.

Reconstructing of Prototype Surface with Reverse Engineering and Data Process Technology

2010 ◽  
Vol 458 ◽  
pp. 368-373 ◽  
Author(s):  
Dong Man Yu ◽  
Xiao Jing Li ◽  
Yi Xiong ◽  
Zhi Hua Gao ◽  
D. Wang
Keyword(s):  
Reverse Engineering ◽  
Measurement Data ◽  
Coordinate Measuring Machine ◽  
Physical Object ◽  
Engineering System ◽  
Complex Data ◽  
Process Technology ◽  
Noise Elimination ◽  
Data Process ◽  
Measuring Machine

Design and manufacture of pioneer products with lower cost and shorter cycle is a major mission for an enterprise, and reverse engineering (RE) plays an important role in accelerating product research and borrowing ideals from other business. However, due to special structure and complex topology relation, obtaining full surface data of a prototype is not an easy thing and should carry out complex data process procedure to get global model. This paper describes the origin point cloud acquisition method and the data processing steps for better point quality. Based on reverse engineering system of a toy prototype, a fine surface reconstruction module is developed. Measurement data are acquired by scanning the physical object using three-dimensional coordinate measuring machine (CMM) and an optical scanning device. The model establishment and data process of the prototype, such as noise elimination, data interpolation, data smoothing, data filtering, data splicing and surface reconstructing are conducted subsequently. Through processing of measurement data, the authors succeed in creating a CAD model of the prototype and gaining a good result.

Best Fit Uncertainty Analysis for Computing Geometric Tolerances

1997 ◽  
Author(s):  
Hong-Tzong Yau
Keyword(s):  
Sample Size ◽  
Measurement Data ◽  
Coordinate Measuring Machine ◽  
Point Location ◽  
Geometric Tolerances ◽  
Surface Deviation ◽  
Measuring Machine ◽  
Point Data ◽  
Geometric Variables ◽  
Best Fit

Abstract In computing geometric tolerances using point data from a coordinate measuring machine (CMM), a best fit process needs to be carried out to bring the measurement data to the coordinate system of the substitute geometry. The measurement data does not precisely conform to the substitute geometry. It involves errors from machining as well as measurement itself. With this error-carrying measurement data, the best fit result contains uncertainties which in turn reduce the accuracy of the evaluated tolerances. In this paper, a model is proposed to estimate the best fit uncertainties caused by surface deviation, point location, and CMM sample size. The model was verified by simulation and experiment. To explore factors that affect the uncertainty variations, geometric variables that influence the uncertainties were first studied. Then, to understand the effect of point location on the uncertainty, optimization using the conjugate gradient method was developed to find the best measurement locations by minimizing the total uncertainties. In addition, simulations showed that the uncertainty is inversely proportional to the squared root of the number of points. This result can be used to predict the CMM sample size that will control the best fit uncertainty under certain tolerances.

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