An intelligent sampling method for inspecting free-form surfaces

The two most important factors in sampling during coordinate verification of a surface are the number of measuring points that accurately represent the surface and the distribution of those points. Three algorithms are developed in this paper for sampling of free-form surfaces at a patch scale (not the entire surface). The three developed algorithms take each patch on the surface as a separate unit and distribute the points within the patch in two steps, namely, sample the most critical points that depend on maximum and minimum Gaussian curvature of each patch and add more points depending on the overall distribution of the most critical points distributed on the surface. In each step of sampling, the maximum difference between the CAD model and the surface created using those sampled points is obtained, and an optimum number of measuring points is determined. This minimizes sampling effort and (non-value-added) measurement time. A comparison is performed between the three proposed algorithms and two well known sampling techniques: the equiparametric approach and the patch-size-based sampling method. The proposed algorithms distribute the points in each patch based on a specific plan. The results show that the developed algorithms help select an efficient number of sampling points.

[1]  Hong-Tzong Yau,et al.  An automated dimensional inspection environment for manufactured parts using coordinate measuring machines , 1992 .

[2]  Tony C. Woo,et al.  Dimensional measurement of surfaces and their sampling , 1993, Comput. Aided Des..

[3]  Chung-Chi Hsieh,et al.  Efficient sampling for surface measurements , 1995 .

[4]  Chia-Hsiang Menq,et al.  The prediction of dimensional error for sculptured surface productions using the ball-end milling process. Part 2: Surface generation model and experimental verification , 1995 .

[5]  Mooyoung Jung,et al.  Integrated precision inspection system for manufacturing of moulds having CAD defined features , 1995 .

[6]  M. W. Cho,et al.  New inspection planning strategy for sculptured surfaces using coordinate measuring machine , 1995 .

[7]  Jerry Y. H. Fuh,et al.  A neural network approach to determining optimal inspection sampling size for CMM , 1996 .

[8]  Yin-Lin Shen,et al.  Sampling strategy design for dimensional measurement of geometric features using coordinate measuring machine , 1997 .

[9]  Kuang-Chao Fan,et al.  Intelligent planning of CAD-directed inspection for coordinate measuring machines , 1998 .

[10]  V. N. Narayanan Namboothiri.  ON DETERMINATION OF SAMPLE SIZE IN FORM ERROR EVALUATION USING COORDINATE METROLOGY , 1999 .

[11]  A. Winsor.  Sampling techniques. , 2000, Nursing times.

[12]  Shivakumar Raman,et al.  On the selection of flatness measurement points in coordinate measuring machine inspection , 2000 .

[13]  Hoda A. ElMaraghy,et al.  Automatic sampling for CMM inspection planning of free-form surfaces , 2002 .

[14]  Shivakumar Raman,et al.  Intelligent Search-Based Selection of Sample Points for Straightness and Flatness Estimation , 2003 .

[15]  Shivakumar Raman,et al.  Experimental verification of manufacturing error pattern and its utilization in form tolerance sampling , 2005 .

[16]  Shivakumar Raman,et al.  Experimental analysis of search-based selection of sample points for straightness and flatness estimation , 2005 .

[17]  Gil-Sang Yoon,et al.  A feature-based inspection planning system for coordinate measuring machines , 2005 .

[18]  Sam Anand,et al.  A design advisor for the optimal inspection of circularity tolerance , 2007 .

[19]  Stephen C. Veldhuis,et al.  CAD-based sampling for CMM inspection of models with sculptured features , 2007, Engineering with Computers.