Flutter Test Data Processing Based on Improved Hilbert-Huang Transform

Table 2

Estimated modal parameters.

	Natural frequency (Hz)			Damping ratio (%)
	First modal	Second modal	Third modal	First modal	Second modal	Third modal
True value	50	70	150	1.0	0.7	0.3
Original HHT	49.239	70.522	4.357	0.913	0.532	0.8
Error /%	1.52	0.75	14997	8.7	24	236
Improved method	49.305	69.185	149.340	0.949	0.681	0.301
Error /%	1.39	1.16	0.44	5.10	2.71	0.33