Oscillatory Failure Case detection in flight control systems via wavelets decomposition

Area of Science:

• Aerospace Engineering
• Control Systems
• Signal Processing

Background:

• The Oscillatory Failure Case (OFC) detection problem was introduced in a joint aerospace industrial-benchmark competition.
• Effective detection of OFCs is crucial for ensuring aircraft safety and operational reliability.

Purpose of the Study:

• To propose and evaluate a fault detection design for addressing the OFC detection problem.
• To address the detection of wide frequency range OFCs within specified performance criteria.

Main Methods:

• The proposed detection scheme integrates an output estimator, wavelet decomposition, and an energy-based denoising method.
• A residual evaluation unit is employed for fault identification.
• The method was tested against competition prescriptions for OFC detection.

Main Results:

• The fault detection method successfully met competition requirements for OFCs within the 1-10 Hz frequency range and specific amplitude thresholds (2.3 mm at rod position sensor, 1.4 mA at servo input current).
• Detection performance was maintained irrespective of disturbance levels, uncertainties, and load factor control inputs.
• In some scenarios, faults were detected slightly beyond the prescribed limits, with notable exceptions.

Conclusions:

• The developed fault detection system demonstrates high efficacy in identifying OFCs under various operational conditions.
• The proposed method offers a robust solution for aerospace fault detection, particularly for OFCs within the specified frequency and amplitude ranges.