Indoor navigation tracks firefighters in blazing buildings

Satellite signals that help us maneuver city streets can't penetrate buildings. Here are two indoor navigation systems that could help emergency workers find life-saving escape routes.
Written by Janet Fang, Contributor

Engineers are racing to develop indoor navigation systems that can track firefighters to within a meter or two. Some are close to succeeding. IEEE Spectrum reports.

Firefighters are specifically trained to deal with disorientation. Still, each year in the U.S., hundreds suffer injuries or have died when they can't get out of burning buildings.

Creating a system for navigating indoors -- where satellite signals don't easily penetrate -- is tough. And consumer products requiring Wi-Fi signals are useless if the power source goes up in flames.

Now, if two groups can clear just a few lingering technical hurdles, they may be able to get equipment in the hands of firefighters, paramedics, and other first responders within the next couple of years.

A U.S. Department of Homeland Security team is working on a gadget that uses gyroscopes and accelerometers to track a wearer’s movements in three dimensions. It’s called Geospatial Location Accountability and Navigation System for Emergency Responders (GLANSER).

  • Units the size of tissue boxes attach to firefighters' breathing gear.
  • Each device packages a military inertial measurement unit (IMU) with a GPS receiver, Doppler radars to correct velocity, a pressure sensor to judge changes in altitude, and a radio to measure the range to a fixed base station and to other nearby units.
  • Before a firefighter enters a building, the initial position is established and a radio beams position changes to the commander.
  • Neighboring wearable units communicate with the base station and with one another, forming a "mesh network," letting them swap location data and relay weak signals.
  • But the components of a portable unit alone add up to $3,000, not counting the fancy battery.

Researchers from the Worcester Polytechnic Institute are working on their Precision Personnel Locator (PPL).

  • Firefighters carry portable units the size of walkie-talkies with a 24-hour battery life and contain a cheap IMU (broadcasts internal position) and a radio transmitter (beams ranging signals).
  • Three stationary radio transceivers link wirelessly to one another and to a laptop-size base station that houses an atomic clock and orients itself and the transceivers using GPS.
  • Transceivers (antennas mounted on trucks or ladders) listen for transmissions from firefighters and pass those signals to the base station.
  • Timing the signals’ arrival from each portable radio helps determine their ranges and calculates their three-dimensional positions.
  • Location data are streamed wirelessly to the commander, who dictates an escape route or directs rescuers over voice radios.
  • To make it mass-producible and cost a few hundred dollars, the team is eliminating expensive, power-hungry hardware by building better software.

[IEEE Spectrum]

Image: Wikimedia

This post was originally published on Smartplanet.com

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