Monday, December 11, 2017

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Using 3D Machine Vision to prevent defects in seals & Sealing devices
 

By Robert Bock  - Chief Scientist, Lumenec Corporation

 


3D MACHINE VISION SEAL INSPECTION SYSTEMS

Seal manufacturers are seeking to eliminate manual inspection and improve defect detection by investing in 3D Machine Vision Seal Inspection Systems. 3D Machine Vision Seal Inspection Systems can be used for improved process control and for satisfying customer inspection requirements:

- Find defective products before they are shipped

- Reduce returns and liability

- Boost production speed

- Reduce labor cost and scrap

- Improve product quality and upstream processes

- Preserve customer goodwill

- Eliminate manual inspection

WHAT ARE THE REQUIREMENTS OF SEAL INSPECTION?

1. Seal Surfaces
All surfaces on the air-side, fluid side and auxiliary lip must be defect free. The contact point on the primary lip is a critical area of concern for seal manufacturers. In addition, the OD of the seal must be inspected for defects. In many cases, the fluid-side lip must be pulled down during inspection so that the spring groove area can also be inspected. Also, it is often critical to verify that the spring groove is fully seated and not damaged.

2. Loading/Unloading and Changeover
Both manual-fed machines and fully automatic systems are needed. In many cases, seal manufacturers are investing in manual-fed machines that can be upgraded to a fully automated system in the future. In addition, a machine vision seal inspection system must be able to accommodate seamless changeover between products. Many manufacturers have 20+ products on a single line.

3. Measurement Tolerances
Seal inspection requires very tight tolerances. Defects that manifest greater than 20 microns upwards/depth and 0.2 mm in width/length must be detectable.

4. Cycle Time
In most cases, loading, inspection, and unloading must be performed in less than 5 seconds, which leaves approximately 1.5 seconds for the machine vision inspection of all critical surfaces.

WHAT ARE THE LIMITATIONS OF CURRENT SEAL INSPECTION TECHNIQUES?

Traditional leak down tests have their limitations. Pumping features on the seal that help move oil away from the contact area can cause problems with leak down tests. In addition, traditional 2D machine vision cannot be used to inspect all the critical surfaces. Typical defects on seals are extremely low-contrast and perfect lighting conditions are required in order to find all the defects on all surfaces. In order to make capital expenditure justification, one must remove manual inspection entirely. As a result, the capex justification cannot be made for a 2D seal inspection system.

BENEFITS OF 3D MACHINE VISION FOR SEAL INSPECTION

3D Machine Vision is ideal for the automated inspection of seals and sealing devices. Since 3D Machine Vision does not depend on complex lighting it can be used to inspect all critical surfaces for low-contrast defects. As a result, 3D Machine Vision eliminates manual inspection. In addition, a single 3D Machine Vision system can accommodate many different seals produced on a given line. Furthermore, since 3D Machine Vision operates at extremely high speeds and high resolutions, 3D Machine Vision Seal Inspection systems can meet the tight tolerances and cycle time requirements of seal manufacturers.

 

Courtesy of Vision Systems Design 


Bitflow Showcase CoaXPress @ SPIE DSS Show

Video frame grabbers are key components in the high-technology vision systems deployed by the military to detect bombs, guide weapons, drive unmanned vehicles, capture images from aircraft, and other applications that keep citizens safe. 

To educate engineers how to make their vision systems more accurate, responsive and productive. 

BitFlow, Inc. will be displaying its field-proven line of video frame grabbers at the upcoming SPIE Defense, Security + Sensing Conference, the industry's leading meeting for scientists, researchers and engineers from industry, military, government agencies, and academia throughout the world. BitFlow will be in booth 813 at SPIE, scheduled for April 29-May 3 in Baltimore, MD.

"Our commitment to the defense sector has led us to engineer frame grabbers capable of extremely fast, zero latency transfer of uncompressed HD video for critical surveillance and guidance,' explained Donal Waide, Director of Sales for BitFlow. "Also, our Software Development Kit (SDK) allows developers to take full advantage of the host computer's capabilities for greater flexibility."

For the first time at SPIE BitFlow will display its Cyton and Karbon CXP frame grabbers, both based upon the CoaXPress interface. CoaXPress is a simple, yet powerful interface that offers video acquisition speeds up to 6 Gigabits per second, along with the ability to send control commands and triggers at 20 Megabits per second, all over a single piece of 75 Ohm coaxial cable in lengths up to 135 meters. Additionally, a maximum 13W of power can be transmitted to a camera along the same cable.

Karbon-CXP frame grabbers are CoaXPress 1.0 compliant, and support anywhere from one to four CXP cameras and up to four CXP multi-links. Cyton frame grabbers incorporates the Gen 2.0 x8 PCI Express bus interface on its back-end, an advancement that doubles the data rate of the Gen 1.0 bus for the ultimate high-speed access to host memory in multi-camera systems, while using the same compact footprint and connectors.

Also on display at SPIE will be BitFlow's wide range of Camera Link solutions, from its low cost Neon models to its high speed Karbon grabbers. Camera Link remains a viable interface in machine vision, especially for military systems.

About BitFlow
BitFlow has been developing reliable, high-performance Frame Grabbers for use in imaging applications since 1993. BitFlow is the leader in Camera Link frame grabbers, building the fastest frame grabbers in the world, with the highest camera/frame grabber densities, triggering performance, and price. With thousands of boards installed throughout the world, into hundreds of imaging applications, BitFlow is dedicated to using this knowledge and experience to provide customers with the best possible image acquisition and application development solutions. BitFlow, located in Woburn, MA, has distributors and resellers located all over the world including Asia, Japan, and Europe.

For more information contact IVS Imaging @ info@ivsimaging.com or 888-446-1301.


Precision Measurment in Machine Vision I

 

Understanding Precision Measurement Concepts

Precision measurement using machine vision technology is a valuable application for online production inspection.  A good place to start in addressing how to successfully perform machine vision metrology is to understand precision measurement concepts.  The term metrology often is used interchangeably with measurement and indeed they are closely linked.  Actually, metrology is the “science of measurement”.  When we talk about metrology in an industrial process, it refers to “applied metrology” or “industrial metrology”; the application of the science of metrology for manufacturing.  As we consider metrology in this sense, let’s review some terms and concepts used in measurement and metrology.

The terms precision and accuracy are used in the specification and qualification of a measurement system.   Precision is the ability to repeat a certain measurement, while accuracy is how well a measurement agrees with a true or known value.  It is very important to understand that accuracy does not provide a very useful metric in determining the quality of a metrology device in the context of the plant floor.  In specifying and qualifying production machine vision solutions, then, precision is most important, and in specific, the uncertainty or bias of the measurement.  The terms uncertainty and bias refer to the amount of variation that will be exhibited by a measurement system over repeated measurements (or the degree of precision).   To be clear, the goal of the on-line metrology system will be to produce a specific measurement with a reliable and repeatable level of uncertainty that meets the application requirements.

For example, a machine vision system might report the diameter of a specific part to be 20.4mm, with an uncertainty over many repetitions of +/- 0.05mm (that is, no measurement of the same part deviated from 20.4mm by more than 0.05mm).  Of course, the actual amount of uncertainty that is acceptable for any application is dependent upon the application specification.

Note:  machining specifications are not the equivalent of inspection specifications.  If a part must be manufactured to 24mm +/- 0.01mm in length, what is the acceptable uncertainty for inspecting that length?  If the inspection uncertainty is specified as +/- 0.01, a good machined part could be 24.01mm in length, but that measurement system would fail it a statistically significant number of times since in this example, the 24.01mm measurement could report between 24.00 and 24.02mm.   To be certain of the target measurement criteria, consult with the quality team and determine in advance the allowable inspection uncertainty based upon the needs of the application.

Next:  Image and inspection resolution (machinevisionsource.com)

 

USB3.0: Revisiting USB Vision

For industrial applications, cameras using USB vision hadn’t seemed to have gained much traction – until the release and proliferation of the USB 3.0 Vision standard.   Although camera manufacturers have been offering USB interfacing before, over the past few months it seems that many new USB 3.0 Vision camera offerings have sprung up  from a variety of vendors.   With that availability of components, and adherence to the USB 3 Vision standard, this interface appears to be reasonably viable for industrial machine vision.  Multiple cameras can be implemented, with very good bandwidth, easy component integration, up to 5 meter native cable lengths.  Further, many vendors offering this interface are implementing cameras with the somewhat less-expensive, but high-speed CMOS sensors (though many are available with CCD sensors).  In the software arena, NI notably recently announced support for USB 3.0 Vision in their latest acquisition driver release.   I think the USB 3.0 Vision standard starts to look appealing, at least for some, if not many applications.  I have not yet used these products on a project, but will be looking for an appropriate situation to try out this technology. 

 

Courtesy of: Machinevisionsource.com


USB3.0 Interface for Machine Vision

 

The development of the USB 3.0 interface was originally driven by the consumer need for a PC based interface with higher bandwidths. The USB 3.0 interface came to market in 2009 with support for up to 440 MB/s of bandwidth; 10 times faster than USB 2.0 and 5 times faster than FireWire-B.

Adoption of the interface increased by mid-2012. Support from major vendors such as Intel, AMD, Microsoft, Apple and the Linux community are under development. At the current rate of deployment, every new PC manufactured in 2015 will support USB 3.0. With adoption of this magnitude, vendors can build applications and deploy them on almost any PC without the need of additional hardware. Pricing for peripherals that are required, such as cables and hubs, will benefit from a highly competitive consumer oriented marketplace.

In terms of machine vision, USB 3.0 offers a number of attractive features in addition to the high bandwidth. USB 3.0 supports Direct Memory Access which allows the data to be written directly to memory reducing CPU processing load. USB 3.0 is capable of delivering up to 4.5 Watts of power over a single USB 3.0 cable. Multiple camera systems can be deployed using USB 3.0 hubs.

In 2011, the AIA decided to implement the USB3 Vision standard. Similarly to GigE Vision, USB3 Vision follows the same robust framework using the GenICam programming interface and XML description files. With this commonality between the two standards, system integrators will be able to easily learn one after working with the other. With its high bandwidth, ease of use, and low cost, USB 3.0 is ideal for a wide variety of applications both within machine vision and in the consumer world.

For more information on IVS Imaging’s line of USB3.0 Cameras & Approved Accessories please contact info@ivsimaging.com now!

Basler USB3.0 Cameras

 



IVS Imaging is a distributor & manufacturer of machine vision cameras, lenses, cabling, monitors, filters, interface boards & more. IVS is your one stop shop for all your vision needs. IVS Imaging is known across the USA for carrying imaging products from leading manufactures, including Sony Cameras and Accessories, Basler Industrial Cameras, Hitachi Surveillance Cameras, Toshiba Network-based IP Cameras, and Sentech Advanced Digital and OEM cameras. Contact IVS Imaging for all your imaging products, parts, and accessories needs.

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