Negru, Sorin A.Geragersian, PatrickPetrunin, IvanZolotas, ArgyriosGrech, Raphael2023-02-092023-02-092023-01-19Negru SA, Geragersian P, Petrunin I, et al., (2023) GNSS/INS/VO fusion using gated recurrent unit in GNSS denied environments. In: AIAA SciTech Forum 2023, 23-27 January 2023, National Harbor, Maryland, USA. Paper number AIAA 2023-2226https://doi.org/10.2514/6.2023-2226https://dspace.lib.cranfield.ac.uk/handle/1826/19163Urban air mobility is a growing market, which will bring new ways to travel and to deliver items covering urban and suburban areas, at relatively low altitudes. To guarantee a safe and robust navigation, Unmanned Aerial Vehicles should be able to overcome all the navigational constraints. The paper is analyzing a novel sensor fusion framework with the aim to obtain a stable flight in a degraded GNSS environment. The sensor fusion framework is combining data coming from a GNSS receiver, an IMU and an optical camera under a loosely coupled scheme. A Federated Filter approach is implemented with the integration of two GRUs blocks. The first GRU is used to increase the accuracy in time of the INS, giving as output a more reliable position that it is fused, with the position information coming from, the GNSS receiver, and the developed Visual Odometry algorithm. Further, a master GRU block is used to select the best position information. The data is collected using a hardware in the loop setup, using AirSim, Pixhawk and Spirent GSS7000 hardware. As validation, the framework is tested, on a virtual UAV, performing a delivery mission on Cranfield university campus. Results showed that the developed fusion framework, can be used for short GNSS outages.enAttribution-NonCommercial 4.0 InternationalConference paper