Vision and UWB-based anchor self-localisation system for UAV in GPS-denied environment

With the increasing applications of unmanned aerial vehicles (UAVs) in industries, it has drawn dramatic interests that utilising UAVs for internal inspection of oil tanks and vessels in recent years. Due to the fact that there is no global positioning system (GPS) and limited prior knowledge about operational environment, it is an unsolved problem on how to get the precise position information without relying on prior knowledge. To solve this problem, a Vision Aided Self-Localisation Two-way Time of Flight (VASTWTOF) algorithm is proposed. In the proposed algorithm, ultra-wideband (UWB) based sensor nodes are utilised for UAVs to achieve precise localisation in GPS-denied environment and the vision-based approach is adopted for anchor self-localisation. The simulation results show that the proposed algorithm can greatly improve the localisation performance and could be used for UAVs' precise localisation in GPS-denied environment, especially for the internal inspection of oil tanks and vessels