Evaluation on Filter Performance of Variational Mode Decomposition and Its Application in Separating Closely Spaced Modes

Table 3

The identified modal parameters.

	Order	Theoretical values	PolyMAX in the frequency domain	Error (%)	Proposed method based on VMD	Error (%)
f (Hz)	1	15.507	15.487	0.129	15.482	0.159
	2	18.941	18.916	0.135	18.911	0.159
	3	28.513	28.511	0.007	28.496	0.059
	4	45.526	45.431	0.012	45.452	0.162
	5	55.646	55.659	0.023	55.639	0.012
ζ (%)	1	0.427	0.389	8.875	0.429	0.441
	2	0.471	0.511	8.438	0.471	0.025
	3	0.312	0.279	10.601	0.321	2.732
	4	0.551	0.493	10.476	0.545	1.113
	5	0.447	0.444	0.603	0.449	0.434