Researchers from Harvard and Cornell University have developed a system based on Wi-Fi sensing that could allow robots to enhance their collaboration abilities in unmapped environments. The system essentially enables robots to measure relative direction, or AOA (Angle of Arrival), to other robots operating in non-line-of-sight and unmapped environments without the need for external navigational infrastructure.
"We do so by capturing all of the paths that a Wi-Fi signal traverses as it travels from a transmitting to a receiving robot, which we term an AOA profile," the researchers wrote in a recently released paper. "The key intuition is to "emulate antenna arrays in the air" as the robots move in 3D space, a method akin to Synthetic Aperture Radar (SAR)." The team looked to derive a system that uses sensors mounted directly onto the robots and looked at the impact of local trajectory estimations, which are imperfect and prone to errors when it comes to the patterns that Wi-Fi signals travel between two robots.
Using that information, the researchers designed a system that captures information on all Wi-Fi signal paths traveling from a transmitting robot to a receiving unit. That system leverages the receiving robot's trajectory to emulate an antenna array. By tracing that array in the air, DOA (Direction of Arrival) algorithms can estimate the travel path of the strongest signal path.
There are many benefits to using this new system, such as allowing robots to estimate other robots' locations in cluttered or unmapped areas where cameras and other sensors might be ineffective. This would no doubt enhance the collaborative properties of robots in those types of environments.