Part Sourcing in a global market

1. Part Sourcing in a global market (A 3D Internet Search Engine) Dr Jonathan Corney (Engineering), Dr Doug Clark (Mathematics), Mr Micheal Breaks (Library), Dr Heather Rea (Research Associate), Heriot-Watt University

2. How many components exist? • 6 Billion People on the planet. • Currently 20 Billion CAD models! (AutoDesk). • Online databases of over 1 Million mechanical CAD models (www.inpart.com) PTC. • We guess between 60 to 600 Billion distinct designs? • How many are moulding, pressings or castings? • How many have 3D CAD representations?

3. Research Vision “One day, soon, engineers will be able to search the Internet for 3D models which are geometrically similar to ones they have designed on their CAD system.”

4. The scenario • A CAD model of a prototype part is exported in a neutral format (VRML,STL). • The part is uploaded to a 3D search engine which presents the engineer with a list of the most geometrically similar parts in its database. • The engineer can change the design to use the existing part or get the supplier to quote for supply of the new component.

5. Our Goal

6. Why will this be useful ? Because the modification, or re-use, of existing parts is far quicker, and cheaper, than starting from scratch: • $1 to $5 million a year saving through the re-use of plastic clips in one Automotive company (Berchtold 1992). • Aggressive reuse of parts could reduce the cost of complex systems by 20% (Cybenko 1996),

7. Why will this be useful ? Potentially it’s a win-win scenario ! • The designers get cheaper parts,faster. • The manufacturers get to sell to a bigger market and re-sell existing “inventory”. So potentially everyone wins from the re-use of existing molds, dies, jigs, fixtures, CNC code and CAD data etc.

8. Why not ? • Cost too much ? Internet economics suggest it will cost nothing. • People will steal the 3D CAD data ? Exact CAD data not required (VRML,STL). • Computers can’t tell if shapes are similar ? True! This is the research. • IPR and contracts will be too complicated? Also part of the research.

9. 3 Year, EPSRC Funded Project £170K From EPSRC over 3 years from June 00 Support in “cash and kind” from 3 collaborators: • Pathtrace.net, (CAD/CAM Software & Internet Services) • Subcontract UK Ltd, (Manufacturing Yellow Pages, www.firstindex.com) • Scottish Polymer Technology Network, (Industry Focus, Business Issues)

10. Project Plan • 1st Year Plan: • Baseline Measurement of Human Performance. • Stand alone geometric similarity algorithms. • Build-up Collections of 3D Models (test data). • Initiate Business Issues Study. • Upload Server.

11. Indexing the database Searching the database Search Engine GUI Web Page Upload File C:/temp/newpart Material polypropelene Part Number:L3567 Desc: Lock pin Material: Steel 535 Strength: 5 N/m2 : : Scale 3:1 Email address Me@here.com Database Geometric Analysis Program Geometric Analysis Program Search Engine Results Display Upload Page Looking for: Found: 84% 79% 52% Filename Volume 3D Model C:/models/l3546 Material Picture Surface Area Steel535 Name Material Lock pin Owner Locksmiths PLC Indices

12. Java3D Prototype

13. Plan for Similarity Algorithms • 3 year plan to implement progressively more exact shape indexes: • Size: Bounding Boxes, Bounding Spheres, Number of Facets. • Physical Properties: Volume, Surface Area, Moments, Crinkliness, Fractal Dimension, Medial Surface. • Normalization:Position, Scale & Orientation. • Spatial Occupancy: Voxel Comparisons

14. Crinkliness* The `crinkliness' of a faceted model is defined as the surface area of the model divided by the surface area of a sphere having the same volume as the model: Crinkliness = *Denis Mollison (1972) `Conjecture on the spread of infection in two dimensions disproved', Nature 240, 467-468.

15. Fractal Dimension Fractal Dimension (D) indicates the degree of detail in an object and how much space it occupies between the Euclidean dimensions: • It has often been applied as a measure of 2D surface roughness and boundary shape. • An increase in D represents an increase in complexity. • But even in 2D significant differences in complexity only contribute to slight differences in D (20%).

16. Basic Concepts of Fractal Dimension 2D Fractal Dimension is determined by calculating either the area, or length of a profile, over a range of resolutions. There are many approaches: • One common method measures the lengths or distances between points on the border. • Another method counts border pixels located within discs of various diameter, where the discs are randomly centeredon the border.

17. Parallel-Planes Method for Calculating Fractal Dimension Estimates the volume of a model by summing the “swept area” of a number of intersection planes: • Horizontal flat planes are specified at regular intervals with pitches ranging from 1 to 50 units. • Intersected area is calculated by intersecting a plane and the model. • All intersected area multiplied by the pitch and summed to give a total volume. The process is repeated for all pitch sizes.

18. Simple Cube Mono-Dice Duo-Dice Tri-Dice No. of primitives 6 12 20 32 No. of polygons 6 4,528 6,493 11,925 Surface area (units3) 60,000 170,474 153,434 128,583 Volume (units3) 1,000,000 803 755 672 925 542 095 Crinkliness 1.1713 3.0208 2.8463 8.9071 D1 (method 1) 1.0223 1.0236 1.0244 1.0268 D2 (method 2) 0.0714 0.0737 0.0737 0.0735 D3 (method 3) 0.0851 0.0929 0.0815 0.0860 D4 (method 4) 0.0689 0.0711 0.0710 0.0706 D5 (method 5) 0.0662 0.0658 0.0681 0.0778 D6 (method 6) 0.0782 0.0815 0.0814 0.0811 Results and Comparisons

19. Normalization • Normalization is needed to allow voxel-voxel comparisons. • Position: Centroid located at the origin. • Size: Scale to fit standard size. • Orientation: Rotation applied to the object to align it with the principle moments.

20. Voxel Comparisons

21. Test Data

22. Physical Properties

23. Matrix

24. Results Target Model “Bone” > 0.7 >= 0.65

25. Results Target Model “Botfig8” > 0.7 > 0.65 > 0.55

26. What is the “correct” answer? ? ?

27. Human Performance Choose the five most similar objects to the circled one.

28. Business Issues Lots of Questions: • Does the commissioner of a part get a royalty every time it is reused ? • Could contractors manufacture components for less in return for “reuse rights”? • Are there existing models which could be adopted to support this sort of trading (Project Alba’s VCX)?

29. Project Plan • 2nd Year Plan • Incorporation of similarity algorithms into an on-line search engine. • First User trials. • Development of more sophisticate tests for geometric similarity (normalization). • Business Issues Report

30. Project Plan • 3rd Year Plan • Large Scale Trials (1000+ parts). • Yet more sophisticated measures of geometric similarity (voxel comparisons). • On-line prototype. • Full developed business model for trading and re-use of mechanical components .

31. Why am I telling you this? We need: • Lots of 3D Models (in VRML or STL format). • People to do take the online similarity tests. • Next year feedback on the prototype.

32. Closing thought If commercial 3D Search Engines appear within the next five years, will commercial pressures force CAD models of almost every manufactured part to be post on the Internet by 2010 ?