Model-Based Loads Observer Approach for Landing Gear Remaining Useful Life Prediction

Abstract

Implementing health monitoring methods for aircraft landing gears holds the potential to prevent premature component replacements and optimize maintenance scheduling. Therefore, this paper introduces a fundamental framework for fatigue monitoring and subsequent steps for predicting the remaining useful life of landing gears. A key component of this framework is the model-based load observer, which lays the groundwork for subsequent remaining useful life prediction steps. This load observer will be analysed in detail in this paper. The model-based approach is specifically designed for observing the loads on civil aircraft landing gears during touchdown, utilizing signals from in-service sensors. To evaluate the load observation method, a flexible multibody simulation model is introduced to generate synthetic data sets of aircraft in-service data and the corresponding landing gear loads, given the unavailability of real in-service and recorded landing gear load data. The load observation method is applied to synthetic in-service data across various virtually performed landing scenarios, offering a proof of concept along with extensive analysis of parameter uncertainties and additional factors influencing observation quality. Through this analysis, certain challenges to the observation method are identified that require further investigation in subsequent research efforts.