Safer aircraft navigation ahead An EU-funded project brought together an expert team to advance the future adoption of a new navigation system for safer aircraft operations. Digital Economy © Shutterstock Some of the most critical tasks in aircraft operation include landings and take-offs, approaches, and manoeuvres or navigation in the terminal zone. The certified navigation systems currently available require heavy airport infrastructures and/or may lack the integrity and accuracy necessary in such operations. These shortcomings call for new systems to either replace or complement existing systems. The 'Helicopter and aeronef navigation airborne systems' (Pegase) project set out to assess the feasibility of a new navigation system that provides a 3D autonomous approach and guidance for airports as well as helipads. Three core technologies are central to the system: specification of a reliable ground reference database, innovative correlation techniques between sensors and the onboard ground database, and a servoing algorithm for managing trajectories of fixed wing and rotary wing aircraft. The servoing technique relies on information obtained from a vision sensor to control the motion of a robot and its positioning relative to the environment - this constitutes a valid approach, considering the robot is the size of an aeroplane. Pegase partners, in line with their areas of expertise, undertook a number of activities aimed at assessing the feasibility of the autonomous, all-weather, localisation and guidance system. They also sought to determine performance criteria required for the vision sensors and the ground reference database. This serves to provide accurate guidance for the take-off run from alignment to final take-off, and from final approach to full stop on the taxiway or helipad. The project team made use of existing simulation and man-machine interface tools developed for both fixed wing and rotary wing aircraft. Work focusing on the sensors enabled a better understanding of the requirements for visual sensors during landing and take-off functions; ultimately this highlighted the need to develop new sensors. Work on existing data sources took into account the emerging satellite systems that will come in to play in the near future. Various methodologies were elaborated for further development, and image-processing algorithms for on-board camera use were developed. The latter are applicable to detection, localisation and tracking, while the development of image- and position-based visual servoing methods advances the automatic landing of fixed-wing aircraft. Pegase's successes pave the way for introduction of a new more cost-effective navigation system boasting higher accuracy and integrity than those currently in use.
