Abstract:
The aim of this study is to propose an alternative approach in prognostics for
airborne avionics system in order to enhance maintenance process and aircraft
availability. The objectives are to analyse the dependency of avionic systems
for fault propagation behaviour degradation, research and develop methods to
predict the remaining useful life of avionics Line Replaceable Units (LRU),
research and develop methods to evaluate and predict the degradation
performances of avionic systems, and lastly to develop software simulation
systems to evaluate methods developed.
One of the many stakeholders in the aircraft lifecycle includes the Maintenance,
Repair and Overhaul (MRO) industry. The predictable logistics process to some
degree as an outcome of IVHM gives benefit to the MRO industry.
In this thesis, a new integrated numerical methodology called ‘System Level
Airborne Avionic Prognostics’ or SLAAP is developed; looking at a top level
solution in prognostics. Overall, this research consists of two main elements.
One is to thoroughly understand and analyse data that could be utilised.
Secondly, is to apply the developed methodology using the enhanced
prognostic methodology.
Readily available fault tree data is used to analyse the dependencies of each
component within the LRUs, and performance were simulated using the linear
Markov Model to estimate the time to failure. A hybrid approach prognostics
model is then integrated with the prognostics measures that include
environmental factors that contribute to the failure of a system, such as
temperature. This research attempts to use data that is closest to the data
available in the maintenance repair and overhaul industry.
Based on a case study on Enhanced Ground Proximity Warning System
(EGPWS), the prognostics methodology developed showed a sufficiently close
approximation to the Mean Time Before Failure (MTBF) data supplied by the Original Equipment Manufacturer (OEM). This validation gives confidence that
the proposed methodology will achieve its objectives and it should be further
developed for use in the systems design process.
