Lightweight infrared sensing for relative navigation of quadrotors

A lightweight solution for estimating position and velocity relative to a known marker is presented. The marker consists of three infrared (IR) LEDs in a fixed pattern. Using an IR camera with a 100 Hz update rate, the range and bearing to the marker are calculated. This information is then fused with inertial sensor information to produce state estimates at 1 kHz using a sigma point Kalman filter. The computation takes place on a 14 gram custom autopilot, yielding a lightweight system for generating high-rate relative state information. The estimation scheme is compared to data recorded with a motion capture system.