A noise reduction method for force measurements in water entry experiments based on the Ensemble Empirical Mode Decomposition

In this paper a denoising strategy based on the EEMD (Ensemble Empirical Mode Decomposition) is used to reduce background noise in non-stationary signals, which represent forces measured scaled model testing of emergency water landing aircraft, generally referred as ditching. Ditching tests are performed at constant horizontal speed 12 m/s and vertical velocity beginning impact 0.45 m/s. The data affected by large amplitude broadband noise, has both mechanical electronic origin. Noise sources cannot be easily avoided or removed, since they associated with vibrations structure towing carriage interaction between measurement chain electromagnetic fields. reduction method decomposition signal into modes its partial reconstruction using residue, signal-dominant some further treated thresholding technique, helps retain sharp features signal. developed tested first synthetic superimposed known noise. then verified inertial force acting fuselage when it moving air, case added mass negligible denoised should equal product acceleration, them being known. Finally, procedure applied denoise during actual ditching experiments. results superior those obtained other classical filtering methods, such average filter low-pass FIR filter, particularly due enhanced capabilities EEMD-denoising here preserve signals residual low-frequency oscillations spurious