Online Update for November 10, 2006

11/10/2006



To SUBSCRIBE | To UNSUBSCRIBE | CHANGE YOUR PROFILE | PRIVACY POLICY

November 10, 2006

Highlights


Sponsored by
Rockwell Automation


New camera technology is allowing video metrology equipment to make many of the same non-destructive surface-shape measurements that coordinate measuring machines (CMMs) can, only faster—and with similar accuracy . The design has been used in applications such as paper quality control and label-quality inspection.





How Extreme are these Machines? Decide for yourself. Cast your vote! Click here. Sponsored by Control Engineering, Design News, and Rockwell Automation.




Digital video improves metrology system performance

Machine control, Software

Incorporating a multi-megapixel machine-vision camera into a video microscope creates a metrology instrument that rivals CMM precision for Digital Precision Corp. Photo: Toshiba Teli America.


The current generation of high-resolution digital video cameras is making it possible to achieve measurement precision with video microscopes that was previously achievable only with coordinate measuring machines (CMMs). With this new camera technology, video metrology equipment can make many of the same non-destructive surface-shape measurements faster and with similar accuracy, the main limitation being that video metrology works best for measuring flat objects in two dimensions.


CMMs achieve high measurement resolution by contacting component surfaces with a mechanical probe held by a robotic arm or gantry. Encoders in the robotic system determine exactly where the probe tip's center is in three-dimensional space, and the CMM's host computer uses that information to determine the contact point between the probe and the part's surface. By probing dozens of points over the part, the CMM builds up a 3-D model of the part's shape matching the accuracy and precision of the encoders' resolutions.


Video microscopes—which use a video camera and a precision lens to capture an image and then store it on a host computer for display or analysis—capture a far larger number of points that CMMs ever could, and do it in a fraction of a second.


Using a high-quality lens system calibrated for the field of view (FOV), image-analysis software running on the system's host computer can isolate and measure all the edges visible in the image. It then calculates the position of each edge in two dimensions. Such a system's advantages are much higher measurement speed and much better coverage of the part's features. The system's disadvantage is difficulty in measuring parts with high relief in the third dimension.

Selection challenges


When challenged with issues of performance and price in the design of newly-ordered video metrology machines, Digital Precision Corp. turned to Toshiba Teli America for cameras that would accurately capture video images of various size work pieces. These images in turn would be transferred for analysis using Digital Precision's proprietary software.


'After reviewing the two designs,' recalls Al Sabeh, a vice president at Toshiba Teli America, 'I recommended incorporating our new CSB4000F four-megapixel CMOS camera with FireWire and 2,008 x 2,047 [pixel] resolution.'


The CSB4000F's ultra-high resolution qualified it for use with large FOV measurement and inspection. Coupled with an FOV microscope, the camera can measure larger size parts, such as 50 x 50 mm, with better than 5 micron accuracy online or off-line without an expensive stage.


Digital Precision incorporated the camera into a modified version of their DP1-FV video microscope system (shown in Figure 1). The camera was the main modification to the system. The digital camera's greater than 4 Mpx resolution made it possible to achieve much higher measurement precision than a standard analog camera.


The new design still uses a MVZL macro video zoom lens with close-up attachment manufactured by Optem (now Qioptiq), and ZView DMP-2000 image capture and analysis software. The lens has a 6:1 optical zoom range from 18-108 mm effective focal length, and a f/2.5 maximum aperture, making it appropriate for metrology applications at working distances from 5.5 to 11-in. (140-279 mm). The software provides features that lend it to automated-metrology applications, such as one-touch calibration, image enhancement to clean up noisy images, and exporting of images and analysis results to other computers.


The design has now been used in a number of applications, such as paper quality control and label-quality inspection. According to Yan Yu, marketing manager at Digital Precision, current applications have moved quality control off-line, but they are looking at in-line applications as well. 'It is a simple matter of reconfiguring the system for automated applications,' she says.


Sabeh, from Toshiba-Teli agrees: 'One of the DMP2000 software's advantages is its ability to link with other applications, such as CAD package and statistical process control (SPC) software, in real time.'


C.G. Masi , Senior Editor, Control Engineering


For more information visit
www.toshiba-teli.com


See also:
www.dpccorp.com
www.qioptiqimaging.com
www.zview.com

 





No comments
The Engineers' Choice Awards highlight some of the best new control, instrumentation and automation products as chosen by...
Each year, a panel of Control Engineering editors and industry expert judges select the System Integrator of the Year Award winners.
Control Engineering Leaders Under 40 identifies and gives recognition to young engineers who...
Learn more about methods used to ensure that the integration between the safety system and the process control...
Adding industrial toughness and reliability to Ethernet eGuide
Technological advances like multiple-in-multiple-out (MIMO) transmitting and receiving
Virtualization advice: 4 ways splitting servers can help manufacturing; Efficient motion controls; Fill the brain drain; Learn from the HART Plant of the Year
Two sides to process safety: Combining human and technical factors in your program; Preparing HMI graphics for migrations; Mechatronics and safety; Engineers' Choice Awards
Detecting security breaches: Forensic invenstigations depend on knowing your networks inside and out; Wireless workers; Opening robotic control; Product exclusive: Robust encoders
The Ask Control Engineering blog covers all aspects of automation, including motors, drives, sensors, motion control, machine control, and embedded systems.
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
News and comments from Control Engineering process industries editor, Peter Welander.
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
This is a blog from the trenches – written by engineers who are implementing and upgrading control systems every day across every industry.
Anthony Baker is a fictitious aggregation of experts from Callisto Integration, providing manufacturing consulting and systems integration.
Integrator Guide

Integrator Guide

Search the online Automation Integrator Guide
 

Create New Listing

Visit the System Integrators page to view past winners of Control Engineering's System Integrator of the Year Award and learn how to enter the competition. You will also find more information on system integrators and Control System Integrators Association.

Case Study Database

Case Study Database

Get more exposure for your case study by uploading it to the Control Engineering case study database, where end-users can identify relevant solutions and explore what the experts are doing to effectively implement a variety of technology and productivity related projects.

These case studies provide examples of how knowledgeable solution providers have used technology, processes and people to create effective and successful implementations in real-world situations. Case studies can be completed by filling out a simple online form where you can outline the project title, abstract, and full story in 1500 words or less; upload photos, videos and a logo.

Click here to visit the Case Study Database and upload your case study.