Adaptive sampling method for inspection planning on CMM for free-form surfaces

Parts must be measured to evaluate the manufacturing accuracy in order to check whether their dimension is in expected tolerance. In engineering, parts with free-form surfaces are generally measured by high-precision coordinate-measuring machines. The measurement accuracy is usually improved by increasing the density of measurement points, which is time-consuming and costly. In this article, a novel sampling method of measurement points for free-form surface inspection is proposed. First, surface inspection is simplified into the inspection of a number of section curves of the surface. Second, B-spline curves constructed with an iterative method are employed to approximate these section curves. Subsequently, data points necessary to construct the B-spline curves are taken as the measurement points. Finally, the proposed method is compared with other two sampling methods. The results indicate that the proposed method greatly reduced the number of measurement points without decreasing the precision of surface modeling.

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An intelligent sampling method for inspecting free-form surfaces

The International Journal of Advanced Manufacturing Technology ◽

10.1007/s00170-008-1427-3 ◽

2008 ◽

Vol 40 (11-12) ◽

pp. 1125-1136 ◽

Cited By ~ 54

Author(s):

Suleiman M. Obeidat ◽

Shivakumar Raman

Keyword(s):

Sampling Method ◽

Free Form ◽

Intelligent Sampling ◽

Free Form Surfaces

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An Adaptive Sampling Approach for Digitizing Unknown Free-form Surfaces based on Advanced Path Detecting

Procedia CIRP ◽

10.1016/j.procir.2013.08.034 ◽

2013 ◽

Vol 10 ◽

pp. 216-223 ◽

Cited By ~ 4

Author(s):

Keqing Lu ◽

Wen Wang ◽

Yaofeng Wu ◽

Yanding Wei ◽

Zichen Chen

Keyword(s):

Adaptive Sampling ◽

Free Form ◽

Free Form Surfaces ◽

Sampling Approach

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Sampling for Free Form Surfaces Inspection Planning

Volume 2: 19th Computers and Information in Engineering Conference ◽

10.1115/detc99/cie-9136 ◽

1999 ◽

Author(s):

Diaa F. ElKott ◽

Hoda A. ElMaraghy ◽

Ashraf O. Nassef

Keyword(s):

Gaussian Curvature ◽

Patch Size ◽

Free Form ◽

Maximum Deviation ◽

Inspection Planning ◽

Nurbs Surface ◽

Cpu Time ◽

Inspection Process ◽

Data Points ◽

Free Form Surfaces

Abstract This paper presents four methodologies for sampling of free form surfaces and discusses their merits and application. These are equi-parametric sampling, patch size based sampling, patch mean Gaussian curvature based sampling, and the combined patch size and patch mean Gaussian curvature based sampling. The locations of points inspected for a NURBS surface are optimized to minimize the maximum deviation between the surface fitted to the data points and the designed surface. During optimization, the inspection process is simulated, a parametric NURBS surface is fitted to the data points and the maximum deviation between the fitted and designed surfaces is minimized. Algorithms for the application of the sampling methodologies were implemented using MATLAB software. Each sampling methodology is explained, and illustrated by an example. The performance of the different sampling methodologies are compared in terms of the maximum deviation obtained and the CPU time needed to accomplish the sampling task.

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Machine Vision and Data Reconstruction for Measuring Free Form Surface

Materials Science Forum ◽

10.4028/www.scientific.net/msf.471-472.508 ◽

2004 ◽

Vol 471-472 ◽

pp. 508-512 ◽

Cited By ~ 1

Author(s):

Hong Wei Zhang ◽

Guo Xiong Zhang ◽

Y. Shi

Keyword(s):

Adaptive Sampling ◽

High Speed ◽

Turbine Blades ◽

Sampling Strategy ◽

Ccd Camera ◽

Free Form ◽

Optical Center ◽

Sculptured Surfaces ◽

Ccd Cameras ◽

Free Form Surfaces

Reverse engineering of free-form surfaces is one of the most challenging technologies in advanced manufacturing. With the development of industry more and more sculptured surfaces, such as molds and turbine blades, are required to measure quickly and accurately. Optical non-contact probes possess many advantages, such as high speed, no measuring force, in comparison with contact ones. The ability of stereovision probe with CCD cameras in gathering a large amount of information simultaneously makes it the most popularly used one in sculptured surface measurements. So based on the laser triangular principle, a measuring and testing device with two CCD cameras was designed, and its accuracy was analyzed. With a virtual 3D target in form of a grid plate, all the intrinsic and extrinsic parameters of CCD camera including the uncertainty of image scale factor and optical center of camera can be readily calibrated. In order to obtain all the required data with high accuracy in a short time, the curvature-based adaptive sampling strategy is presented. Due to huge amount of arbitrary scattered points, the Delaunay triangular division and Bezier interpolation and NURBS interpolation are applied to get a continuous surface.

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