Multiprocessor speeds baggage inspection
"By measuring the attenuation of x-rays as they pass through the lumber, high-density knots and other defects can be examined," says Bill Wong, project manager at Newnes. "Statistical correlation then predicts the tensile and bending strength of the wood." The system also activates a paint sprayer that applies a mark to indicate the lumber`s strength.
By reducing the potential for jamming, the machine can be placed in-line with the lumber production system, saving floor space and reducing handling costs. Because of its noncontact scanning, the x-ray scanner can analyze wood faster than tensile-stress-testing equipment.
Bill Wong can be contacted at (604) 273-2248.
InVision Technologies (Foster City, CA) is not the only company using multiprocessors to speed baggage detection at airports (see p. 24). In December, Vivid Technology (Woburn, MA) announced that it has sold more than 100 of its Vivid VIS systems to European airports.
Vivid`s systems use dual-energy x-ray techniques to analyze the size of objects and their atomic number to determine whether explosives are present in baggage. Using VME-based SKYbolt multiprocessors from Sky Computers (Chelmsford, MA), Vivid systems are capable of inspecting up to 1500 bags per hour. Unlike the InVision Technologies CTX-500, Vivid`s systems do not perform computed tomography (CT) of objects.
"CT-based systems are too expensive and too slow," says Kristoph Krug, Vivid`s director of research, design, and development.
In operation, baggage images are digitized by x-ray sources at both high and low voltages. Because matter reacts differently to each of these pulses, the atomic number of material in the baggage can be determined.
To process the data, Vivid manufactures a variety of systems, each with different levels of processing. In its simplest configuration, the Level 1 system uses three SKYbolt VME processors to compute image data.
"We chose Sky more than seven years ago," says Krug, "because of Sky`s development tools." Unfortunately, because the system needed to be very reliable, it could not run under UNIX. Because of this, Krug chose a 486-based CPU from RadiSys (Hillsboro, OR) and DOS as the operating system.
For its next-generation system, Vivid would like to increase processing through put by ten times. According to Krug, the company is now considering different architectures and off-the-shelf processors. "But when you are shipping product," adds Krug, "you cannot just change computer architectures overnight." Kristoph Krug can be reached at (617) 938-7800.