%% Example: Bearing Vibration
% Load the vibration signal from a defective bearing generated in the Compute Hilbert Spectrum of Vibration Signal example. The signal is sampled at a rate 10 kHz.

load bearingVibration

% Compute the first five intrinsic mode functions (IMFs) of the signal. Plot the Hilbert spectrum of the first and third empirical modes. The first mode reveals increasing wear due to high-frequency impacts on the bearing's outer race. The third mode shows a resonance occurring halfway through the measurement process that caused the defect in the bearing.

imf = emd(y,'MaxNumIMF',5,'Display',0);
subplot(2,1,1)
hht(imf(:,1),fs)
subplot(2,1,2)
hht(imf(:,3),fs,'FrequencyLimits',[0 100])

% Copyright 2019 The MathWorks, Inc.