March 8, 2016

Connectivity Lab custom-designs two-axis gimbal for air-to-air and air-to-ground laser communications

By: Amnon Talmor, Chien-Chung Chen, Harvard K Harding Jr

Originally published on the Facebook Code blog.

We started the Connectivity Lab at Facebook to see if we could develop a range of new technologies that would help accelerate the process of bringing connectivity to areas that don’t have access to internet infrastructure.

We’re focusing the research on laser and millimeter-wave (MMW) communications for terrestrial, high-altitude unmanned aerial vehicles (UAVs), and satellites. Laser and MMW technologies allow us to leverage large bandwidths of communications data and, in some cases, unlicensed spectrum. In one scenario, laser or MMW beams transmit data initially from a fiber point of presence gateway to a UAV, then from UAV to UAV until the backhaul they’ve created extends far enough to the desired location.

To make this work, the team custom-designed a gimbal to be used onboard UAVs. The gimbal had to swivel, be lightweight, and be aerodynamically appropriate for the job. The slideshow below shows various designs the team considered, the one they ultimately decided on, and a description of the final design.

This video shows the gimbal being tested in our lab. The state-of-the-art gimbal is made of carbon fiber and magnesium composite to keep the weight down to about 3.5 kilograms — and is at least two times lighter than the existing gimbal technology.

To learn more about the design decisions they made to achieve these goals, you can read further details in this paper.