Machine vision technology is used extensively throughout manufacturing to improve product quality, increase productivity and reduce costs. One of the reasons for that is a machine vision system will work tirelessly on mundane repetitive tasks at high speed with great precision.

Figure 1. Teledyne DALSA’s BOA smart camera is about 44 mm on a side. The BOA is IP67 rated and, with a suitable lens enclosure, can be used in wet environments.
The typical implementation involves configuring camera systems to capture and analyze the manufacturing process against user defined acceptance criteria. Costly errors associated with incomplete or incorrect assembly can then be quickly identified and eliminated to assure customer satisfaction and brand protection. Machine vision systems can also be integrated directly into the factory control network for efficient data sharing and process monitoring.

A wide range of applications and industries can benefit from machine vision inspection, including automotive, electronics, medical, packaging, pharmaceutical, semiconductor and general manufacturing.

Smart Cameras

One of the latest advances in machine vision technology involves the use of so-called “smart” cameras. What are “smart” cameras and how do they simplify machine vision?

A smart camera combines the functionality of a digital camera, processing, software, and communications into one small package. Smart cameras are an excellent choice for a machine vision system handling tasks such as positioning, identification, verification, measurement, or flaw detection.

Smart cameras are easy to integrate at an affordable price, while consuming very little space and power. Some smart cameras are specifically designed for industrial use with an IP67-rated housing, which means that the camera can be directly deployed in harsh, wash-down environments. This is particularly useful to meet cleanliness standards in the food and pharmaceutical industries, and it eliminates the need for a separate, costly protective enclosure.

The small form factor and easy mounting capabilities of many smart cameras allow them to be integrated easily into existing production lines, machinery, or moving equipment.

How the Software Works

Figure 2. Teledyne DALSA’s iNspect vision software running on a BOA “server” as viewed through a personal computer “client.” Tools are graphically selected (on the left) and applied to the part image (on the right). Dialogs, such as the one shown on the lower right, are used to set parameters.
Fully integrated, easy-to-use software is a key factor to consider when choosing a smart camera. PC-based machine vision systems and smart cameras require programming because they are general-purpose tools. However, if the programming takes too much time, the benefits of a machine vision project will quickly evaporate. Therefore, easy-to-use software is required for rapid and successful development of a machine vision application.

For example, Teledyne DALSA’s BOA smart camera uses iNspect machine vision software, the same easy-to-use software that is available on PC-based machine vision systems. Vision applications are “programmed” graphically — you point-and-click to select a tool, such as a caliper, and then position that tool on the part to be measured. There is no programming in the conventional sense. Vision operations are presented in familiar terms, rather than the terms of machine vision algorithms. For example, the caliper tool is presented as if it was a mechanical gage so you don’t need to understand sub-pixel edge detection algorithms.

The smart camera acts as a “server” on an Ethernet network and has no way to display images itself. Instead, images are sent over the Ethernet to a “client” PC (Personal Computer). You set up and program the smart camera from the client PC and then “log off” of the smart camera and let it run independently. Results are reported over Ethernet using standard industrial protocols or via digital input/output lines from the camera. Consequently, one “client” PC can manage many smart cameras.

The Smart Camera in Action

Figure 3. At Prime Engineered Components, parts from a vibratory bowl go into an index wheel that rotates to show the part to the smart camera for dimensioning. (Source: Prime)
Prime Engineered Components in Watertown, CT manufactures precision-turned products for industries ranging from aerospace to automotive. The company produces 800,000 parts per week. Since defective parts cause expensive returns and hurt customer relations, Prime uses smart cameras for their 100% quality inspection.

“We elected to put vision in place for a multitude of dimensional inspections,” says Kathy Dibble, Director of Quality for Prime. “We would much rather remedy any quality problems in-house before product ships to our customers.” The BOA’s ease of use and programming, along with its accuracy, were the primary reasons Prime decided to implement smart cameras in their machine vision system.

One Prime facility manufactures mostly screw machined parts — parts with grooved patterns such as threaded anchor bolts. Critical dimensions for these parts include the minimum and maximum dimensions of the threads. To measure these dimensions, the parts are fed by a vibratory feeder into slots on an index wheel. The wheel turns to position the part in front of the smart camera and a “caliper tool” measures the thread dimensions.

The quality of the parts going out the door has increased dramatically since the smart camera solution was implemented during the spring of 2010. Machine downtime stemming from frequent issues with the old vision system has been greatly reduced. In addition, Dibble and her team are thrilled with the ease of use of the BOA, in particular with the embedded iNspect Express interface. iNspect Express allows users to build solutions using a comprehensive toolset that is accessed via a web browser from a standard PC or laptop, and it connects directly to a variety of Ethernet-ready factory devices.

“It’s a simple, streamlined machine vision application that has worked wonders for our quality control,” concludes Dibble.

Summary

Today’s smart cameras, packaged complete with application software, offer scalable vision solutions designed to satisfy a wide range of application needs from positioning robotic handlers to complete assembly verification, so if you’re looking for a powerful and quick-to-deploy machine vision solution, consider a highly integrated smart camera that comprises all of the elements of an industrial machine vision system.

This article was written by Ben Dawson, Director of Strategic Development, Teledyne DALSA Corporation (Waterloo, Ontario, Canada). For more information, contact Dr. Dawson at This email address is being protected from spambots. You need JavaScript enabled to view it., or visit http://info.hotims.com/34454-201.


Photonics Tech Briefs Magazine

This article first appeared in the May, 2011 issue of Photonics Tech Briefs Magazine.

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