Machine vision is used in virtually every industrial manufacturing market from general manufacturing to semiconductor manufacturing. 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 generally are a low-cost system 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 Assn. concluded that more than 50% of illumination systems sold to the North American vision market in 2005 were based on LEDs. Overall, these advances make machine vision more affordable for tasks that previously would not have justified the cost. Consultant Don Braggins of Machine Vision Systems feels “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 insures 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 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.
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
PV310 monochrome vision systems offer 13 pre-processing image functions that can be combined to enhance difficult to find defects. They can transfer images in real time via Ethernet. Together with a 360 degree, low-contrast-matching function or flaw checker, it detects defects on uneven surfaces. Auto Area Adjustment automatically adjusts the inspection area to cover the work piece. Panasonic Electric Works; 908/464-3550; www.pewa.panasonic.com
What the Eye Can’t See
Used with an IR LED illuminator, the 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
Vision-Integrated Display Inspection
VidiaSys PC-based software supports semi-automated inspection of LCDs. The modular software enables various functional blocks to be combined and exercised as needed to address a variety of LCD related inspection tasks. Standard systems detect pixel and line defects and problems with luminance or uniformity. The Value Engineering Alliance; 617/492-1252; www.the-v-e-a.com
Imaging Library (MIL) 8.0 with Processing Pack 3 has a metrology module that calculates the 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.xom
High-Speed Industrila 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 1400x1024 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