Phone app can guide user around buildings

CAMBRIDGE, Mass., Feb. 14 (UPI) -- A smartphone app may soon guide people through unfamiliar buildings by shining lighted arrows on the ground before them to show the way, U.S. researchers say.

The Guiding Light app, developed at the Massachusetts Institute of Technology, consists of a wearable badge with magnetic sensors and software that makes use of a projector built into many Samsung smartphones to project the arrows onto the ground.

The system relies on a map of the building based on fluctuations in its magnetic field created by the presence of steel in the walls, floor and ceiling, an MIT release said Tuesday.

The map is created by walking through a building wearing a badge that contains four magnetic sensors, which record changes in the magnetic field at each point in the building.

The map is then loaded onto a phone. To navigate around the building, a user must wear a similar badge that "talks" to the map on the phone, confirming their position.

A specific location can be keyed into the app and Guiding Light will continuously project an arrow onto the floor ahead to take the user to that location.

Similar indoor positioning systems using WiFi nodes or Bluetooth sensors embedded in walls require the user to stare at maps on their phones to see where they are headed, researcher Jaewoo Chung said.

Guiding Light does not, he said.

"We wanted people's eyes to be on their environment," Chung said.