2011 IR&D Annual Report

Investigation of Model-Based Diagnostic Methods, 09-R8104

Principal Investigator
David A. Ogden

Inclusive Dates:  09/28/09 – 04/01/11

Background — This project explored various diagnostic techniques using empirical data and physics-based models. Previous internal research projects addressed anomaly detection technologies. This project is related to those previous efforts by addressing diagnostics, which is the next step in the detection, diagnostic and prognostic process that enables a condition-based maintenance (CBM) system. In improving and automating the diagnostic process, project team members developed a configurable physics-based model to be fused with empirical sensor data acquired from in-flight data. The improved and automated methods developed for this project represent advancement beyond the state of the art for aerospace propulsion engine diagnostics.

Approach — The main objectives of this project were to create a configurable physics-based model and to develop analysis methodologies that fuse the physics-based information with sensor data to provide a high level of diagnostic automation and precision.

Accomplishments — With this approach, pattern/regime recognition and classification algorithms and particle swarm intelligence-based diagnostic algorithms were created and tested. The pattern recognition algorithms proved reliable for operational regime classification and sensor validation. The particle swarm diagnostic algorithms fuse the formerly disparate data sets of empirical data and physics-based models. These algorithms reduce diagnostic time by automatically directing maintenance personnel to the failed module, even if the failure is not predefined as a fault.

Future efforts for this project will address using the pattern recognition algorithms as a diagnostic tool for alerting users to previously defined failures, using the particle swarm optimization algorithms for selecting an optimal set of features to be used for diagnostics, and using the physics-based model to calculate and test using additional health parameters that are available once the model and data are fused.

Figure 1. Cost Information Associated with One Particle during a Diagnostic Analysis.
Figure 1. Cost Information Associated with One Particle during a Diagnostic Analysis.

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Southwest Research Institute® (SwRI®), headquartered in San Antonio, Texas, is a multidisciplinary, independent, nonprofit, applied engineering and physical sciences research and development organization with 9 technical divisions.