Quadrotor control for RF source localization and tracking

Preliminary results on quadrotor control strategies enabling omnidirectional radio frequency (RF) sensing for source localization and tracking are discussed. The use of a quadrotor for source localization and tracking requires a tight coupling of the attitude control and RF sensing designs. We present a controller for tracking a ramp reference input in yaw (causing rotation of quadrotor) while maintaining a constant altitude hover or translation. The ability to track a ramp in the yaw angle is crucial for RF bearing estimation using received signal strength (RSS) measurements from a directional antenna as it avoids the need for additional gimbaling payload. This bearing or angle of arrival (AOA) estimate is then utilized by a particle filter for source localization and tracking. We report on extensive experiments that suggest that this approach is appropriate even in complex indoor environments where multipath fading effects are difficult to model.