Northfield, MN--When the surveying crews at Schneider Excavating use computers, they don't bother with a mouse or a keyboard. Nor do they set their computers on desktops. Instead, they snap them around their waists and go to work.
By wearing their computers instead of carrying them, Schneider Excavating crews say they've dramatically improved the process of surveying. "We're 150% more efficient than we were with lap-tops," notes Fred Hartzheim, a civil engineer for the Lannon, WI-based firm. "We can double our work output, even when we cut our crew size from two to one."
The key to Schneider's success is the availability of a "hands-off" computer that responds to voice control, rather than a mouse or keyboard, and wraps around the user's waist like a wide belt. Manufactured by Via Inc. and designed by engineers at Logica Product Development, Minneapolis, MN, the ViA II Wearable PC offers a simple way for users to have access to computing capabilities while they move around.
The unit accomplishes that by incorporating voice recognition software in a PC-type hardware package. It includes a 180 MHz Cyrix Media GX chip, RAM memory of up to 64 Mbytes, a flat-panel display, and a 1.6-GByte hard drive, along with power supplies and other typical PC hardware.
To make the ViA II fit in a belt-like pouch, Logica engineers set out to make it thin and flexible. "Our first priority was to make it as slender as possible," notes Kevin Johnson, principal engineer for Logica. "But it also needed to bend across the wearer's back--the idea being that it had to be comfortable over long periods of time."
To accomplish that, Logica engineers took the traditional internal components of a PC and split them into two separate modules. One module incorporates the CPU chip, a display chip, RAM memory, and a two-card expansion slot for additional applications. The second module includes a motherboard, daughterboard, small rotating hard drive, power supply electronics, input/output, and electronics for two smart battery ports. Together, the two modules measure about 10 inches long by 3 inches high by about 1 inch thick.
The technical challenge in breaking the hardware into two modules was to maintain normal communication between the components, without having a rigid pc board serve as the means of that communication. To accomplish that, Logica engineers used a flex circuit developed by Packard-Hughes Interconnect (Irvine, CA). The flex circuit enables the major components on both sides--including the CPU chip, hard drive, and memory--to communicate with each other. It employs a high-density technology known as Gold Dot, which packs 150 contacts in an area less than a square inch. With that high density connection, the computer can pass signals back and forth between the modules across 150 separate circuits.
At the same time, the connection between the two modules is flexible enough--and rugged enough--to stand up to the tension, bending, and torsion of everyday activity. Logica engineers designed rigid case halves made from a polycarbonate ABS alloy. The case halves are insert-molded with a polyurethane elastomer at the flex region between the two modules. The chemical bond of the polyurethane to the polycarbonate ABS ensures mechanical strength and continuous environmental protection for internal components.
The other major challenge for ViA II's engineers was heat dissipation. With circuits packed so tightly and the voice recognition requiring continuous CPU activity, engineers needed to find ways to move heat out of the package. Logica used Pro/MECHANICA analysis to evaluate designs early in the development process. Analysis showed that the disk drive side would be sufficiently cooled by passive convection through a finned heat sink, while the CPU side would require forced convection from a miniature fan.
For power, the wearable computer employs an off-the-shelf lithium ion battery, which can provide up to 43W-hours of charge.
The resulting ViA II wearable computer was released as a product late in 1998. A handful of business users are finding that the ViA II can make work go more smoothly. Schneider Excavating, for example, has been able to cut its surveying teams from two men down to one. Quality control experts in the auto industry are employing it for real-time inspection and record keeping of automotive assemblies as they come off the line.
The unit, including the computer, belt assembly, and battery, weighs just 39 oz (55 oz with the flat panel display). "When this computer is harnessed to your back, you barely know it's there," Johnson says. "And with it, you can run anything that your desktop can run."
Additional details on the computer…
Contact ViA Inc., 11 Bridge Sq., Northfield, MN 55057; 1-800-FLEXI-PC.
Additional details on the design process…
Kevin Johnson, Logica Product Development, 411 Washington Ave. N., Suite 101, Minneapolis, MN 55401; 612-672-0726, or www.teamlogica.com.
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