Automated Low Cost 3D Scanning

Automated Low Cost 3D ScanningAutomated Low Cost 3D Scanning

Nasir Mannan, CCATThomas Tong, 3D3 Solutions

© 2010 Connecticut Center for Advanced Technology Inc. All rights reserved.

About CCAT

• CCAT-The Connecticut Center for Advanced Technology, Inc.• NCAL-National Center for Aerospace Leadership.• Nonprofit organization that serves as economic development center for

excellence for the region, state and nation.• Core programs address military and civilian industrial manufacturing Core programs address military and civilian industrial manufacturing

needs.• Collaborating with 3D3 Solutions to develop push button 3D scanning

solutions in the aerospace and automotive industries.


About 3D3 Solutions

• 3D3 Solutions is a research and development company that develops 3D i t h l scanning technology.

• Our focus is on flexible white light 3D scanning systems.• Works with companies to develop custom scanning solutions for specific

needs such as high resolution, high speed or low cost. g , g p


Overview/Introduction

Current Manufacturing ProcessF ll d di i d b i• For small and medium sized businesses

• Common metrology process• Equipment

IIssue• Bottlenecking

ResolutionI t d ti t t t t• Introduction to non-contact measurement

• Making it easy to use• Making it cost effective

H ldi h • Holding the accuracy• Reporting


Small and Medium Businesses

• Suppliers to major OEM companies• Limited on resources and specialized skilled workers• Most produce parts for OEM’s at high rates• Must produce parts to quality standard• Have limited budgets for improvements• Have limited resources to research new technologies


Equipment for Quality Control

As parts come off from manufacturing it goes to quality control. There are two basic pathways for inspection.

Coordinate Measuring Machines Hand Gauging Tools


Common Metrology Process


Bottlenecking

Bottlenecking occurs when parts are manufactured

3 hours

parts are manufacturedfaster than they are beinginspected during the qualitycontrol process.

2 weeks

3 hours


2 weeks

Bottlenecking


Resolution: Non-Contact Measurement

Use of 3D scanning to measure parts for quality inspection.


White Light 3D Scanning Systems

• A projector projects a series of reference patterns onto the scan object.

• The scene is captured using 1 or 2 camerascameras.

• 3D scanning software processes the images from the cameras to acquire the data needed to create a q3D model.

• Compared to a laser scanner, it takes a full view of the object i d f i l binstead of using laser beam.

• Takes a few seconds to create a single scan.


Automation

O b tt i• One button scanning• 3D scanning generally takes lots of work

(depends on the complexity of the scan object)• Goal of technology is to save time effort• Goal of technology is to save time effort• Whole object scanning with a single click


Automating the Pipeline

Report or Manufacturing

2. Scan Alignment

3. Scan Merging

4. Data Filtering and Conversion

1. Acquire Data

Scan


Complete Data Acquisition

• If the object is small and easily moved: Move the object• If the object is small and easily moved: Move the object• If the object is large and difficult to move: Move the scanner


Multiple Scanners

Th f lti l h d t ll d b PC• The use of multiple scan heads controlled by one PC• Fast 3D data capture


Data Alignment

One scanner• Manual feature alignment• Motion control alignment• Photogrammetric dots

Multiple scanners• Geometric object alignment


Data Cleanup

Automated Cleanup• Noise Filters

H l Filli• Hole Filling• Scan Merging• Abnormal Triangles

S thi• Smoothing

one scan (left) vs. multiple scans of an object (right)


Making it Cost Effective: Data Acquisition

I di id l d b hi hlIndividual scans need to be highlyaccurate because downstreamingcannot improve the quality and

f h daccuracy of the data.


Making it Cost Effective: Hardware

S ll d di b i h li i d • Small and mediums businesses have a limited resources• Make technology cost effective by using off-the shelf hardware

components (ie. projectors, cameras, lenses)


Making it Cost Effective: Post Processing

• Range of mesh editing tools to sample, filter, smooth, enhance, decimate, li h i l d d i l d halign, merge, remesh, etc…point clouds and triangulated meshes.

• Reverse Engineering modules allows users to create solid or surface models from scan data.

• Inspection modules allows whole deviation 3D measurement for part Inspection modules allows whole deviation 3D measurement for part qualification.


Holding the Accuracy: Tracking the Positioner

The coordinate system of the positioner table needs to be accurate in orderfor data alignment to be accurate.


Holding the Accuracy: Target Registration

• Align two scans together using features in your scan (ie. spheres).R i th h d t th t i t f th h d • Recognizes the spheres and captures the center point of the sphere and use it for alignment.


Holding the Accuracy: Global Registration

ICP (I i Cl P i )ICP (Iterative Closest Point):

• Associate points by nearest neighbor criteria.• Estimate transformation parameters using a

mean square cost function.mean square cost function.• Transform the points using the estimated

parameters.• Iterate (re-associate the points and so on).• Provides better accuracy.


Holding the Accuracy: Automation

• Use a positioner table with reference spheres for one button scanning.• Then align the data using target registration with global alignment.


Case Studies: Accuracy

Single Camera Scanning and Alignment Simulation Scan - Idealg g g

46 sec 31 sec


Case Studies: Accuracy

Single Camera Scanning and AlignmentAccuracy Indicator

scan 1 vs scan 2 scan 2 vs scan 3 scan 3 vs scan 4

Simulation Scan - Ideal


Causes for Accuracy Distortion

Using a single camera:Slight rotation creates mis-alignment ofprojector and camera coordinate systems.


Solution: Accuracy Improved Using Two Cameras

Improve scan accuracy by usingtwo industrial cameras.


Case Studies: Accuracy Improved Using Two CamerasAccuracy Improved Using Two Cameras

Two Camera Scanning and AlignmentAccuracy Indicator

scan 1 vs scan 2 scan 2 vs scan 3 scan 3 vs scan 4

Simulation Scan IdealSimulation Scan - Ideal

Case study proves that off-the-shelf hardware can produce accurate


results for quality inspection and aerospace at lower cost.

Reporting

Most post-processing software have reporting function for quality inspection.


Automatic Reporting

Acquire Scan

Fixture Part Index Part End of Program Target Align Merge ReportFixture Part Index Part End of Program Target Align Merge Report

Automate these steps


Automation Process

10 min

83 h 8 16 h8 hour 83 hours 8.16 hours


Future Plans

E i t ith diff t ti l t h i / t ti l ith t • Experiment with different optical techniques/reconstruction algorithms to solve shiny part scanning without coating

• Multi scanner setup for faster quality inspection• Multi scanner setup for faster quality inspection

• Large area scanning at high accuracies

• Deform mesh alignment – account for movement.

• High accuracy single camera calibration• High accuracy single camera calibration


Thank you!Thank you!

Nasir [email protected]

Thomas Tong3D3 Solutions

[email protected]
