CRONOS 3D DIMENSIONAL CERTIFICATION This dimensional certification is structured as follow: 1. 2. 3. 4. 5. Test description Dimensional report basic workflow Dimensional report, acquisition field 18mm Dimensional report, acquisition field 35mm Dimensional report, acquisition field 5mm 1.Test description 1.1. Given the fact that a common accepted norm to certify the accuracy of a white structured light scanner does not exist yet, Open Technology s.r.l adopted an highly accurate self-made method. 1.2. The test object has been designed and crafted by highly skilled engineers and technicians, the choice has fallen to a milled stone block with different geometric entities on its upper surface. The material was adopted due to its crushproof characteristics and resistance to external factors; the shapes help the user through the alignment and simplify the detection of significant points. The object appears as in the following picture.
1.3. The test object has been constantly measured with a Coordinates Measuring Machine by the College of engineering, Data analysis department of the University of Padova in order to regularly have, updated and accurate parameters (1792 certain points). 1.4. Softwares used for the test are Optical RevEng 2.2 (Open Technologies s.r.l) for the acquisition and Stl generation, and Geomagic Control (3D Systems) for the final alignment and 3D comparison. 2.Dimensional report basic workflow 2.1. Test calibration, eventually re-calibrate the system. 2.2. Set the test object on the turn table selecting Direct alignment as reconstruction method, start an automatic acquisition of eight range images. No alignment data were obtained from the turntable's axis of rotation. 2.3. Select and delete outliers points and cluster of outliers points with the respective tools. 2.4. Perform a global alignment on the pointclouds, checking the global optimization box. 2.5. Generate an optimized polygonal mesh. 2.6. Export the.stl(binary) file and import it in 3ds' Geomagic Control 2.7. Align the scan data with the CMM data using same features, pyramids vertex and centres of the two sphere projected on the base plane. 2.8. Geomagic Control's 3D comparison. 2.9. Detection of significant points and computation of distances.
3.Dimensional report, acquisition field 18mm 3.1. Equipment: OPT Cronos3D 18mm, 3. Mpx sensors Calibration master (Crystal, 15mm marker's pitch) Syncronized rotating table 3.2. Results: Reference model OpenMarble Test equipment Cronos 3D - 18mm 3. Mpx sensor No. of data points 1776 3.2.1. Alignment statistics Pair Distance Angle Plane base 5mm 2 Spheres line mm Projected centre_big sphere mm 3.2.2. 3D comparison results Tolerance Tolerance Type 3D deviation Units Millimeters Max. critical Max. nominal.6 Min. nominal -.6 Min. critical Max.upper deviation.59 Max.lower deviation.54 Average deviation.13/-.15 Standard deviation.16
Standard s Distribution (+/-) No. of points Percentage -6 * Std. Dev. -5 * Std. Dev. -4 * Std. Dev. -3 * Std. Dev. 11.614-2 * Std. Dev. 217 12.19-1 * Std. Dev. 727 4.569 1 * Std. Dev. 636 35.491 2 * Std. Dev. 149 8.315 3 * Std. Dev. 24 1.339 4 * Std. Dev. 15.837 5 * Std. Dev. 8.446 6 * Std. Dev. 5.279 3.2.3 Significant points C1: Projected centre of the bigger sphere on the plane base C2: Projected centre of the smaller sphere on the plane base C3: Centre of the central sphere V1: Vertex of the pyramid lying beside the bigger cylinder V2: Vertex of the pyramid lying beside the smaller cylinder Name Measured Nominal C1_C2 246.877 246.872 V1_V2 219.892 Status Upper tol. Lower tol..4 219.875.18 12.888 12.886.2 C1_V1 143.796 143.789.7 C2_V2 142.315 142.315 C1_V2 195.4 195.371.29 V1_C2 198.863 198.848.15 12.888 12.886.2 C2_C3
4.Dimensional report, acquisition field mm35 4.1. Equipment: OPT Cronos3D 35mm, 2. Mpx sensors Calibration master (Crystal, 15mm marker's pitch) Syncronized rotating table 4.2. Results: Reference model OpenMarble Test equipment Cronos 3D - 35 2.Mpx sensor No. of data points 1764 4.2.1. Alignment statistics Pair Distance Angle Plane base mm Spheres line mm Projected centre_big sphere mm 4.2.2. 3D comparison results Tolerance Tolerance Type 3D deviation Units Millimeters Max. critical Max. nominal.6 Min. nominal -.6 Min. critical Max.upper deviation.58 Max.lower deviation.56 Average deviation.39/-.2 Standard deviation.2
Standard s Distribution (+/-) No. of points Percentage -6 * Std. Dev. -5 * Std. Dev. -4 * Std. Dev. -3 * Std. Dev. 6 3.41-2 * Std. Dev. 365 2.691-1 * Std. Dev. 675 38.265 1 * Std. Dev. 58 28.798 2 * Std. Dev. 131 7.426 3 * Std. Dev. 25 1,417 4 * Std. Dev. 5 * Std. Dev. 6 * Std. Dev. 4.2.3 Significant points C1: Projected centre of the bigger sphere on the plane base C2: Projected centre of the smaller sphere on the plane base C3: Centre of the central sphere V1: Vertex of the pyramid lying beside the bigger cylinder V2: Vertex of the pyramid lying beside the smaller cylinder Name Measured Nominal C1_C2 246.87 246.872 V1_V2 219.96 Status Upper tol. Lower tol. -.2 219.875.31 12.885 12.886.1 C1_V1 143.786 143.789 -.3 C2_V2 142.38 142.315 -.7 C1_V2 195.395 195.371.24 V1_C2 198.849 198.848.1 12.885 12.886 -.1 C2_C3 128.65 -.3
5.Dimensional report, acquisition field 5mm 5.1. Equipment: OPT Cronos3D 5mm, 1.3 Mpx sensors Calibration master (Crystal, 3mm marker's pitch) Syncronized rotating table 5.2. Results: Reference model OpenMarble Test equipment Cronos 3D - 5mm 1.3 Mpx sensor No. of data points 1769 5.2.1. Alignment statistics Pair Distance Angle Plane base mm Spheres line mm Projected centre_big sphere mm 5.2.2. 3D comparison results Tolerance Tolerance Type 3D deviation Units Millimeters Max. critical Max. nominal.6 Min. nominal -.6 Min. critical Max.upper deviation.74 Max.lower deviation -.91 Average deviation.12/-.17 Standard deviation.19
Standard s Distribution (+/-) No. of points Percentage -6 * Std. Dev. -5 * Std. Dev. 3.167-4 * Std. Dev. 8.446-3 * Std. Dev. 43 2.4-2 * Std. Dev. 171 9.542-1 * Std. Dev. 657 36.663 1 * Std. Dev. 679 37.891 2 * Std. Dev. 188 1.491 3 * Std. Dev. 32 1,786 4 * Std. Dev. 8.446 5 * Std. Dev. 3.167 6 * Std. Dev. 5.2.3 Significant points C1: Projected centre of the bigger sphere on the plane base C2: Projected centre of the smaller sphere on the plane base C3: Centre of the central sphere V1: Vertex of the pyramid lying beside the bigger cylinder V2: Vertex of the pyramid lying beside the smaller cylinder Name Measured Nominal C1_C2 246.887 246.872 V1_V2 219.874 Status Upper tol. Lower tol..15 219.875 -.1 12.9 12.886.13 C1_V1 143.792 143.789.3 C2_V2 142.294 142.315 -.21 C1_V2 195.49 195.371.38 V1_C2 198.843 198.848 -.5 12.9 12.886.13 C2_C3