A strategy removing the need for aircraft to use their main engines during taxiing is being studied by a research project being coordinated by the Institute of Aerospace Technologies at the University of Malta, in collaboration with HandsOn Systems and Malta Air Traffic Services.
The strategy proposes the use of autonomous, electric tow trucks to move aircraft between the terminal and the runway, and vice-versa, during taxi operations, Stefano Zaninotto, an engineer said.
The project, called Satmet, is focusing on three main challenges, the first being the introduction of autonomous towing operations on the airfield while keeping air traffic controllers (ATCs) aware of what was happening but without increasing their workload.
For this purpose, Satmet was developing a system which would be responsible for allocating a tow truck to each taxiing aircraft; determining the optimal path to be followed by the tow trucks and aircraft and detecting and resolving any conflicts between vehicles on the taxiways.
Mr Zaninotto said the system would provide ATCs with information regarding the movement and status of each vehicle, and alert them about any impending conflicts. It would also enable ATCs to give taxi clearances and to modify paths proposed by the system.
The second challenge was to detect obstacles around the autonomous tow trucks. For this purpose, Satmet was developing techniques to detect obstacles using multiple sensors to accurately pinpoint nearby objects so that safe passage of the tow truck to the desired runway or terminal could be determined.
Through accurate measurements of obstacle positions, the tow truck would be able to allow enough clearance to tow an aircraft safely. This technology would contribute towards the elimination of ground collisions mostly attributed to pilot error.
Preliminary results demonstrated that the accuracy and confidence of obstacle information could be improved by fusing data from multiple sensors. If a sensor fails, obstacles could still be detected by the remaining sensors. The resulting accuracy was expected to be in line with that required for autonomous taxi operations, Mr Zaninotto said.
The third challenge was to ensure that each autonomous tow truck followed the taxiways precisely – especially when towing an aircraft – without deviating from the taxiway centreline.
Satmet was proposing the mounting of visible and infrared cameras on the tow truck to detect taxiway line markings and estimate the position of the tow truck relative to the centre of the taxiway.
Mr Zaninotto said such a system would be able to cope with different weather and visibility conditions and would not be dependent on external systems such as the Global Positioning Systems.
By addressing the challenges described above, Satmet would contribute to an increase in the safety and efficiency of ground operations and a reduction of environmental impact. It was envisaged that the proposed solutions would facilitate various ATC tasks and improve situation awareness.
Satmet is financed by the Malta Council for Science and Technology, for and on behalf of the Foundation for Science and Technology, through the FUSION: R&I Technology Development Programme.