Arlington, VA--A portable laser backpack for 3D mapping has been developed at the University of California, Berkeley (UC Berkeley), where it is being hailed as a breakthrough technology capable of producing fast, automatic, and realistic 3D mapping of difficult interior environments.
Research leading to the development of the reconnoitering backpack was funded by the Air Force Office of Scientific Research (AFOSR) and the Army Research Office (ARO) under the guidance of program managers Jon Sjogren, AFOSR, and John Lavery, ARO.
Data acquisition while walking
The backpack is the first of a series of similar systems to work without being strapped to a robot or attached to a cart. At the same time, its data-acquisition speed is very fast, as it collects the data while the human operator is walking, in contrast to existing systems in which the data is painstakingly collected in a stop-and-go fashion, resulting in days to weeks of data-acquisition time.
Using this technology, Air Force personnel will be able to collectively view the interior of modeled buildings and interact over a network in order to achieve military goals such as mission planning.
Under the direction of Avideh Zakhor, lead researcher and UC Berkeley professor of electrical engineering, the group has developed this more-portable method of mapping that relies on sensors or lightweight (less than eight ounces) laser scanners.
"We have also developed novel sensor-fusion algorithms that use cameras, lasers, range finders, and inertial-measurement units to generate a textured, photo-realistic, 3D model that can operate without GPS input," said Zakhor.
Building a point cloud
Basic research issues include calibration, sensor registration, and localization. Using multiple sensors facilitates the modeling process, though the data from various sensors do need to be registered and precisely fused with each other in order to result in coherent, aligned, and textured 3D models. Localization is another technical challenge, as without it, it is not possible to align scans from laser scanners to build the 3D "point cloud," which is the first step in the modeling process.
"It is fair to say that embarking on such a hands-on project to make indoor 3D modeling a matter of routine, a number of research questions of a fundamental nature came up," said Sjogren. "It is typical of the work that professor Zakhor has done for AFOSR/Air Force Research Laboratory over the years that she meets these challenges head-on, and in most cases solves the problem sufficiently to demonstrate a prototype system."
Sjogren noted that what is left for others is to examine the approach that was taken, and extend the techniques that were brought in, to a wider context.
The scientists plan to model entire buildings and develop interactive viewers that allow users to virtually walk through buildings before they are there in person.
In the meantime, the cutting-edge technology is being successfully implemented on campus. "We have already generated 3D models of two stories of the electrical engineering building at UC Berkeley, including the stairway, and that is a first," said Zakhor.
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John Wallace | Senior Technical Editor (1998-2022)
John Wallace was with Laser Focus World for nearly 25 years, retiring in late June 2022. He obtained a bachelor's degree in mechanical engineering and physics at Rutgers University and a master's in optical engineering at the University of Rochester. Before becoming an editor, John worked as an engineer at RCA, Exxon, Eastman Kodak, and GCA Corporation.