Quality Innovations: Machine Vision Made Affordable

By Neal Lorenzi

The Sentinel Smart Camera from Webview Inc. (Santa Rosa, CA), now being introduced to the industrial market, is designed to make machine vision affordable for a wide range of manufacturers. Available with a line of sensors, ranging from VGA to mega pixel, color to monochrome, it can be fitted with a line-scan sensor for surface inspection applications. In addition, the camera can be configured by the machine operator or integrator; or, Edu-Key upgrades can be added to configure the camera for thousands of applications.

Philip Russo, Webview president, says the driving force behind developing this product was to make machine vision compact, smart and affordable. “During the years that Webview has done system integration, we’ve been told many times that machine vision is too expensive,” he explains. “So we decided (with this program) to make it affordable. We were able to reduce the cost and size of the package and make it environmentally friendly. Power usage is much lower than with traditional systems; yet, output is powerful.”

In the past, machine vision required the use of large computer, rack- mounted systems that cost up to $200,000, according to Russo. Systems are now available in the $20,000 to $40,000 range. In contrast, the Sentinel system is priced around $3,000. Thus, it is being marketed as an affordable solution to parts inspection.

Sentinel Smart Camera uses FPGA and DSP functions to perform image processing. Source: Webview Inc.

The Sentinel series of cameras are self-contained units that use field programmable gate array (FPGA) and digital signal processor (DSP) functions to perform image processing. Images of scanned objects can be viewed and archived on a PC via a built-in USB port. Setup of the inspection system can be accomplished via a PC or through an Edu-Key module and port. The target market is any part inspection with rates up to 3,600 parts per minute, as well as continuous process inspection known as webs. Virtually any nonpatterned material such as glass, paper, plastics, wood and metal reportedly can be inspected at speeds up to 3,000 feet per minute.

The Sentinel’s on-board sensor uses light from the object being scanned and digitizes the signal for processing by the FPGA. The FPGA can run custom and standard intellectual property (IP) cores that execute DSP functions at video rates on the data. The camera can operate standalone or, when connected to a host computer running Windows XP or 2000, can display and archive images and reports. It is set up from the computer and begins inspection at power-up.

Sentinel finds the center of the package, measures the tilt, then determines the presence or absence of each pill. It also detects any broken pills. Source: Webview Inc.

According to the manufacturer, the camera can scan both linearly or radially for defects. A variety of inspection locations on a single part also can be programmed. It identifies defective parts via color graphics and archives images of defects for later analysis. Multiple cameras can be used on a single production line for more complex inspections, such as those featuring spherical products.

Besides adaptability and low power consumption, the following attributes are noted by the manufacturer: small footprint; easy setup with Edu-Key or PC; choice of sensors-area array or line scan; USB 2.0 communication (480 Mbps); single 24VDC supply; remote sensor head option; multiple camera imaging; optically isolated inputs and outputs; ability to control and strobe illumination sources.

Edu-Key allows the camera to be configured for a variety of inspections. Webview does the engineering; an end-user or integrator purchases a specific key and attaches it to the camera. The inspection configuration automatically transfers to the camera. Source: Webview Inc.

Education

The Edu-Key programming feature is a key attribute of the Sentinel series. Webview offers a range of Edu-Keys, which contain all the parameters necessary to inspect a particular part. This eliminates the need to reprogram for different products; instead, the operator merely plugs in a new Edu-Key.

“For most companies that use machine vision, continuing cost is a major concern,” Russo remarks. “To change inspection parameters, they either use an in-house software writer or hire an outside integrator. With this system, the operator plugs in the Edu-Key which, in effect, becomes a teacher to the camera. It allows the operator to achieve the result at a low cost. Within minutes, he is up and running with a new inspection process. In essence, Edu-Key allows the operator to be comfortable making changes within a short time frame.”

Russo says that with traditional smart cameras, in most cases, the machine operator or integrator must write a software routine or program to achieve the desired inspection. However, Webview can draw on its 35 years of field experience to offer a virtual library that can be customized for almost any inspection and setup in the camera using the Edu-Key module or a PC.

“The Edu-Key programming feature and proven algorithms make it possible for owners to standardize on one system, with one software platform doing different inspection routines at each of their plants worldwide. Sentinel units are registered by serial number, which includes any Edu-Key routines provided for that unit, so that replacement can be accomplished by overnight shipment,” Russo says.