Robust Navigation System for UAVs in GNSS-and Magnetometer-Denied Environments

Navigating in environments where GNSS- and magnetometer measurements are unreliable can lead to a significant decrease in state estimation accuracy. The use of supplementary measurements, either from optical sensors or otherwise, could enhance the state estimates notably even when at low quality. Using inertial navigation corrected by a multiplicative extended Kalman filter, state estimation is performed on a simulated UAV in motion. This paper has investigated the effect of adding measurements of body-fixed velocity and specific force as reference vectors to the navigation systems of UAVs in GNSS- and magnetometer denied environments. A case study for each of the two measured vectors is performed, and compared to a reference flight without dropout of GNSS or magnetometer, and a flight with dropout, but without any additional aiding sensor.