One of several ground robots move into position with compact low-VHF antennas. (U.S. Army)

Army and Universities Deploy New Warfighter Communication Technology

February 1, 2021

Researchers from the U.S. Army and the University of Maryland, College Park, have developed a controller for deploying robots that forms antenna arrays to maintain longer-range wireless communication. Antennas are distributed between mobile robots, allowing the controller to autonomously guide robots to create and maintain a reliable wireless communication network in challenging battlefield environments.

Recent progress in antenna design for the lower bands of the very high frequency, or VHF, range and corresponding research shows it is possible to form multi-robot antenna arrays, said Jeff Twigg, a researcher with the U.S. Army Combat Capabilities Development Command’s Army Research Laboratory.

Twigg, CCDC ARL, and from the University of Maryland created an approach to maximize overall network connectivity. Through simulation, they tested their approach and demonstrated its ability to increase communication range by automatically increasing array size.

“We proposed a simple way to model the antenna gain created by forming a particular type of antenna array, which is composed of passive (unpowered) and active (powered) antennas,” Twigg said.

Robots move to positions where they can reflect and focus a signal for directional communication. (U.S. Army)

“We also determined the speed and direction in which these antenna arrays should move so that a network of these antenna arrays will always be connected. Our research also describes how quickly new antenna-robots should be added to different antenna arrays and where these antennas should be placed.”

Theses arrays increase communications range by using robots composing the array to position passive antennas that reflect and focus radiation around a robot with an active antenna. They extend communication range in a desired direction in urban and indoor environments.

Existing control formulations are not general enough to support this new capability, Twigg said. “We want to know how to deploy groups of these arrays.”

Future Priorities

When soldiers need to communicate over a longer distance, they need to increase the power of their transmitter and/or the gain of their antenna, Twigg said. “This approach allows us to increase the gain without increasing power,” he said.

Maintaining connectivity between an ensemble of autonomous or semi-autonomous systems is critical for mission completion, Chopra said. The new framework successfully addresses this problem in challenging operational environments, he said.

For the Army, this research is critical to its , which will allow it to fight and win in multi-domain operations.

“The Next Generation Combat Vehicle and Network Command, Control, Communications and Intelligence Modernization Priorities require innovative ways of establishing and maintaining communications,” Twigg said. “This research describes how autonomous or semi-autonomous vehicles can create and maintain a reliable communications network.”

According to Twigg, this research will help guide concepts about how parasitic antenna arrays should be deployed. In the short term, it will help soldiers know when and where to create parasitic antenna arrays. In the long-term, he said, it will guide robots and other autonomous systems to automatically maintain communication.

Several groups of robots that are poorly connected are not positioned to form arrays. (U.S. Army)

Groups of robots form arrays and maneuver to increase overall network connectivity. (U.S. Army)

“Our approach is especially reliable in challenging environments where there are high buildings or dense forest cover,” Twigg said. “In these environments, Wi-Fi or cellular coverage is not reliable. This research and future efforts will help develop technologies that enable reliable communication for these environments.”