Najjar, L. J., Thompson, J. C., & Ockerman, J. J. (1997, March). Using a wearable computer to improve the performance of quality assurance inspectors in a food processing plant. Paper presented at the CHI'97 Workshop on Wearable Computing, Atlanta, GA.
Lawrence J. Najjar, J. Christopher Thompson, and Jennifer J. Ockerman
Georgia Institute of Technology
Georgia Tech Research Institute
Multimedia in Manufacturing Education Laboratory
(404) 894-3412
gt4708d@prism.gatech.edu
When trying to collect and record data, quality assurance inspectors in food processing plants face a variety of tough challenges. Inspectors must walk all around the plant to collect and measure samples at different processing points. So, the inspectors must use a data recording system that is mobile. To collect food samples, inspectors must use both of their hands. After collecting a food sample, inspectors' hands are covered with the food. So, to avoid contamination of the food and damage to their recording equipment, inspectors must be able to enter data without using their hands. The inspectors work in an extremely noisy environment and must wear hearing protectors. So, providing auditory information is a major challenge. Finally, the plant manager wants immediate access to the quality assurance data collected by the inspectors.
Traditional data collection systems do not meet these requirements. Clipboard-mounted forms are mobile and can be used in a noisy environment. However, this system requires that inspectors use their hands and does not give the plant manager instant access to data. Networked desktop computers can give the plant manager instant access to data and can be used in a noisy environment. However, desktop computers are not mobile and require that inspectors use their hands to operate them. Laptop, palmtop, and pen-based computers with wireless network connections offer mobility, can be used in a noisy environment, and can give the plant manager instant access to data. But these small computers still require that inspectors use their hands.
The Georgia Tech Research Institute is investigating the use of a wearable computer to meet these tough challenges. We built three generations of wearable computers. Each generation is lighter, smaller, and more powerful than its predecessor. Our most recent wearable computer includes:
To power the computer, we developed easy-to-replace, rechargeable, nickel metal hydride battery packs. We also developed a unique power management system that maximizes battery life and provides battery status to the user. To complete our system hardware, we added a noise-cancelling microphone, a head-mounted, monochrome display, an earphone, and noise-reducing ear plugs. The wearable computer software includes the Windows95 operating system, wireless network software, voice-recognition software, and a customized application that we developed for quality assurance inspectors. You can see photographs of our wearable computer at http://mime1.marc.gatech.edu/EPSS.
We demonstrated our proposed wearable computer system and application to managers and quality assurance inspectors at a food processing plant. Both groups of people were very excited about our concept. They believe that our wearable computer system will make it easier for quality assurance inspectors to do their jobs and for plant management to get immediate access to the quality assurance data. The quality assurance workers said that they are willing to wear the system and even asked if they could try on our prototype.
Building our wearable computer system and application taught us several user interface design lessons. They are:
Based on our experience, it is our position that the applications that are most appropriate for wearable computers are ones in which:
Applications that are consistent with these characteristics include in-the-field maintenance repair support, mobile quality assurance inspection, and remote, collaborative work (if the wearable computer is equipped with a video camera and a wireless network connection).
We believe that the most appropriate input modality for wearable computers is voice. Voice input is natural, quick, and light in weight. To provide voice input, a wearable computer needs to include a lightweight, highly-directional, noise-cancelling microphone and speaker-dependent, voice recognition software (speaker-independent voice recognition software is ultimately preferred). However, until voice recognition technology is extremely accurate (e.g., greater than 95% accurate), wearable computer systems may need to include a backup cursor positioning and selection device (such as a trackball with a selection button).
We believe that the most appropriate output devices for wearable computers to support the applications described above are head-mounted displays and earphones. Currently, the best, reasonably-priced head-mounted displays provide monochrome, VGA-quality resolution. For wearable computers to become popular, the quality of head-mounted displays must match the quality of the users' desktop computers. Future head-mounted displays should be full-color and provide SVGA-quality resolution. Also, head-mounted displays need to be light, comfortable, adjustable, and easy to remove. Regarding earphones, for the applications described above, a single, lightweight, easy-to-adust, earphone should adequately meet the user's needs.
As computers become lighter, they become more specialized. Wearable computers will not be the next generation of popular computer. However, wearable computers can fill a unique niche for users who are mobile, need to use their hands for other tasks, and need to send and receive information. Wearable computers are coming, and they are here to stay.