Machine vision is used in virtually every industrial manufacturing market from general manufacturing to semiconductors. When machine vision was introduced, it was costly and limited in its capabilities. All that has changed. According to Vision Machines Inc., “Machine vision systems for industrial inspection now generally can be classified into three types: smart camera system, GUI-oriented systems, and traditional, fully programmable systems.”
Smart camera systems are basic systems that process image data at the camera. They’re generally low-cost systems with little or no programmability, and perform basic inspection tasks. GUI systems are programmable, using a point-and-click, graphical interface. Some versions of these systems can generate or incorporate traditional programming code, as well. They offer shorter development cycles, and can be modified by plant personnel. Traditional vision systems are fully programmable in a standard language such as C, C++, or Visual Basic.
These systems generally offer the highest level of flexibility and power, but development times typically are longer and require more experienced personnel.Today, many machine vision systems offer faster, higher-resolution systems, easier-to-use software, and cameras with built-in processing. The use of LEDs as an illumination source reduces costs. The Automated Imaging Association concluded that more than 50% of illumination systems sold to North America’s vision market in 2005 were based on LEDs. Overall, these advances make machine vision more affordable for tasks that previously wouldn’t have justified the cost.
Consultant Don Braggins of Machine Vision Systems says, “The emergence of standards is the most significant trend in machine vision. The first of these is the Camera Link standard for interfacing cameras to the frame grabbers that digitize analog video signals. The standard ensures easy integration of these devices, even from different manufacturers. Connectors, cables, data format, and control signals all are synchronized. Industry-standard cables also will drive competitive pricing when manufactured in volume.”
More recently, the GigEVision standard emerged. It regulates how gigabit Ethernet connects cameras to computers, not necessarily with a frame grabber. “Currently, this method is somewhat slower than Camera Link,” adds Braggins, “but GigEVision provides the advantage of separating the camera from a computer at unlimited distances.” With these standards in place, users can mix and match cameras, frame grabbers, and processors. As a result, various manufacturers can provide replacement parts at any time.
Machine Vision Systems
High-Speed Performance Vision
In-Sight 5600 vision sensor line includes standard (640x480) resolution and two megapixel models for high-speed applications. All sensors have an IP67 (NEMA 4) rating to withstand dust and washdown without an accessory enclosure, and include a library of advanced vision software for inspection, identification, measurement and alignment tasks. Cognex; 508/650-3000; www.cognex.com
Imaging Library (MIL) 8.0 with Processing Pack 3 has a metrology module that calculates measured and constructed geometric features derived from a template, and also validates tolerances based on a template. The module can determine the measurement of features such as arcs, circles, line segments and points for imaging processing. Matrox; 514/822-6000; www.matrox.com
Impact family of high-speed intelligent cameras are configurable using supplier’s software suite that includes a tools for deploying vision inspection solutions in the factory environment. KickStart offers preconfigured setup panels. Vision Program Manager lets users deploy a complete vision solution from start to end, and Control Panel Manager provides an HMI to suit various application requirements. PPT Vision; 952/996-9500; www.pptvision.com
What the Eye Can’t See
Used with an IR LED illuminator, CS8620Hi near-IR RS-170 analog camera provides detailed surface inspection of superficial irregularities, blemishes, or defects not easily observed in the visible spectrum. Suited for factory automation, image measurement and various machine vision applications, it features a 380,000-pixel (EIA) CCD that attains a horizontal resolution of 570 TV. Toshiba Teli America; 949/770-8354; www.toshiba-teli.com
Three PCI-Express-based frame grabbers—PCIe-8255R, PCIe-8231 and PCIe-1427—offer support for every major digital camera bus including IEEE 1394b, Gigabit Ethernet (GigE) Vision and Camera Link. Each frame grabber offers vision acquisition software, a single interface for acquiring, saving and displaying images from industrial cameras. National Instruments; 888/280-7645; www.ni.com
High-speed Industrial Imaging
Genie-HM640, HM1024 and HM1400 GigE vision-compliant digital cameras capture image data at speeds to 295 fps in VGA resolution or 60 fps at 1,400x1,024 resolutions for high-speed industrial imaging applications. The cameras transmit data over standard CAT5e and CAT6 cables up to 100 m allowing for a greater distance between the camera and inspection system. Dalsa; 514/333-1301; www.dalsa.com