Special-purpose, "intelligent," computer-controlled, highly miniaturized radio transceivers have been proposed for use in monitoring critical and/or valuable pieces of equipment. These transceivers and associated electronic circuits would perform both diagnostic and prognostic monitoring functions: They would acquire and provide information on the history and current status of the monitored equipment. On the basis of this information, they would predict impending failures of components. Then they would order replacements for components expected to fail soon or for consumable supplies (e.g., fuel) expected to be exhausted soon; these orders would be submitted so that the needed replacements would arrive just in time.

An 'Intelligent' Transceiver connected with 'smart-part' sensor chips would provide information on the status of the equipment in which the sensor chips were embedded.

The intelligent transceivers were conceived as means to relieve highly mobile military forces of much of the burden of maintenance and logistics. They could also prove useful in civilian industries in which it would be cost-effective to anticipate needs to replace components and/or replenish supplies; examples could include the automotive, vending-machine, and shipping industries.

Intelligent transceivers would have dimensions of no more than a few centimeters. They could be mass-produced relatively inexpensively by use of established integrated-circuit fabrication techniques. An intelligent transceiver would be connected with "smart-part" microchips that would be designed into major components and subassemblies of the equipment to be monitored (see figure). These microchips would contain sensors and sensor circuitry for monitoring the physical conditions and statuses of components and subassemblies. The sensors and circuits would be designed and calibrated to be especially sensitive to such failure-inducing phenomena as excessive wear, overstress, and temperature anomalies. The output signals from the smart chips would be collected by the transceiver and processed by algorithms that would predict times of probable failure of specific components.

An application-specific integrated circuit (ASIC) within the transceiver would provide the sensor-signal-processing algorithms and would serve as the interface between the rest of the transceiver and the smart sensor chips. During normal operation, the principal function of the ASIC would be to scan the sensors and perform continuous self-interrogation and diagnosis. Meanwhile, the time accumulating on each monitored component would be sent to a transceiver memory for continuous updating. During this operation, anomalies expected to lead to failures would be identified and times to failure would be estimated. The collected data would be processed into "plain-language" text with supplemental information derived from the memory, and requests for replacement of parts expected to fail would be transmitted — all automatically.

Functions and characteristics of intelligent transceivers, in addition to those described above, would include the following:

  • Each transceiver would contain a small battery or other power source and a small antenna for transmitting and receiving over a limited range; however, in normal operation, it would be connected, via a standardized receptacle, to a larger antenna and a power source in the monitored equipment to enable communication over a longer range.
  • Although a transceiver would automatically signal the need for replacement of parts or other maintenance actions, it could also be interrogated manually for information on the status of the monitored equipment.
  • Each transceiver would record the maintenance history of the monitored equipment.
  • All components of the monitored equipment would be identified, in a transceiver memory, by part numbers.
  • Instructions for repair and replacement would be contained in each transceiver memory and would be accessible via an infrared link to a display unit.
  • Each transceiver would contain a Global Positioning System (GPS) receiver.
  • Each transceiver would be capable of autonomously communicating with other transceivers to ascertain their locations.
  • A transceiver on a damaged piece of equipment could interrogate other damaged pieces of equipment to determine what components could be salvaged and whether a replacement for a damaged component in its own damaged piece of equipment was locally available.
  • Each transceiver would be capable of "learning" and updating its "knowledge" of the rates of wear of critical components.

This work was done by Philip Moynihan and Govind Deshpande of Caltech for NASA's Jet Propulsion Laboratory. For further information, access the Technical Support Package (TSP) free on-line at www.nasatech.com/tsp  under the Electronics & Computers category. NPO-20699


This Brief includes a Technical Support Package (TSP).
"Intelligent" Tranceivers Would Predict Failures of Parts

(reference NPO-20699) is currently available for download from the TSP library.

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This article first appeared in the June, 2000 issue of NASA Tech Briefs Magazine.

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