Backpack-mounted system maps places unreachable by GPS
By Ben Coxworth
March 27, 2013
Mapping environmental threats in GPS-inaccessible locations – such as underground installations, or the passageways of ships – can certainly pose some challenges. While there are robotic systems that can do the job, robots aren’t necessarily the best choice for cramped quarters or uneven terrain. That’s why a team of scientists at Johns Hopkins University have developed the backpack-mounted Enhanced Mapping and Positioning System ... or EMAPS.
Produced for the Defense Threat Reduction Agency, the EMAPS device itself takes the form of a cube measuring about six inches (15 cm) per side and weighing less than four pounds (1.8 kg).
It incorporates one 270-degree laser scanner that measures distances to walls and other objects, along with a second laser that can be combined with the first one to collect that data in 3D. A camera can be added to continuously capture omnidirectional images, while additional sensors automatically register and map the location of hazards such as radiation or toxic chemicals.
An inertial sensor keeps track of the wearer’s movements (and thus their relative location within the environment), and is able to compensate for the roll, pitch and yaw of their gait. All of the sensory data is gathered at a rate of about one “picture” per step, and is processed and stored in real time to create an annotated floor plan-style map, using custom algorithms on an onboard computer.
So far, EMAPS has been used to collect over 100 hours of mapping data from a variety of locations in which GPS doesn’t work. MIT and the University of California, Berkeley are also developing backpack-mounted mapping systems for use in such places.