More than half of fatal commercial airline accidents occur during near ground operations, such as take-off, final approach and landing. These near ground accidents can be caused by flight control performance failure due to bad weather or mechanical issues or by failure of the navigation and guidance performance due to, for example, poor visibility. “Enhancing flight safety during such critical operational phases is an important key to reducing the number of aviation accidents,” says Yoko Watanabe, Project Coordinator of the VISION (Validation of Integrated Safety-enhanced Intelligent flight cONtrol) project, a jointly funded initiative of the EU and Japan. The VISION project is helping reduce the number of civil aviation accidents by developing smart technologies for aircraft Guidance, Navigation and Control (GN&C) and, more importantly, by conducting in-flight evaluations. Although previous projects have evaluated advanced GN&C solutions to detect flight anomalies, their uptake has been slow due to a lack of flight validations. The VISION project aims to overcome this hurdle by conducting flight validations on real aircraft platforms, including the JAXA MuPAL-alpha in Japan and the USOL K50 in Europe. Impressive results Although the project is ongoing, researchers have already achieved some remarkable results, including the flight validation of Fault Detection and Diagnosis (FDD)/Fault Tolerant Control (FTC) designs. “Whilst there has been extensive academic research in the area of model-based FDD and FTC designs, most of the resulting ideas have only been tested in simulation,” explains Watanabe. “In this project, FDD/FTC control designs are being flight-tested onboard a full-scale, two-engine research aircraft, where they accommodate failures in real-time.” Researchers also developed two vision systems. One involves control surface monitoring in conjunction with the FDD function in auto-pilot, while the other is a long-range stereo vision system for runway feature detection and to aid aircraft during final approach. Both patent-pending systems have been successfully flight-tested on real aircraft. Another key outcome is the development of a vision-integrated navigation system augmented with an integrity monitoring function. The design was evaluated in simulations with real sensor data taken on a K50 UAV platform, with the results confirming an improvement in both navigation performance and fault detectability. The design is now being prepared for flight testing. Towards certification These validations are the first step towards raising the technology readiness levels (TRLs) of the state-of-the-art, advanced FDD/FTC techniques being developed by the project. This is a necessary step before flying them on real test planes developed by such leading manufacturers as Dassault, Airbus and Mitsubishi. “To our knowledge, this is the first time advanced FDD/FTC flight control designs have been flight-tested on a full scale, real aircraft – a result that we are particularly proud of,” says Watanabe. “These outcomes will contribute to raising the TRL of the advanced aircraft GNC techniques, which will reduce a pilot’s tasks during critical situations and enhance the overall flight safety of civil aircraft operations.” The next task for researchers is to work on providing the theoretical proof of the flight controller stability and the navigation integrity of the methods – both essential steps towards having the project’s advanced GNC solutions certified for use in civil aviation aircraft.
VISION, aviation, flight safety, near ground operations, Guidance, Navigation and Control (GN&C)