Time-Varying Modal Parameters Identification by Subspace Tracking Algorithm and Its Validation Method

Table 1

Error comparison of identified pseudo-natural frequencies.

SNR	Tracking algorithm	MAPE (%)
		1st order		2nd order		3rd order
		Original	Validated	Original	Validated	Original	Validated
30	PAST	1.75	1.42	0.24	0.24	0.62	0.62
	API	1.75	1.45	0.24	0.24	0.62	0.62
	NPI	2.50	1.45	0.24	0.24	0.62	0.62
	NIC	1.81	1.49	0.24	0.24	0.62	0.62
10	PAST	1.92	1.61	0.24	0.24	0.62	0.62
	API	1.95	1.66	0.25	0.25	0.75	0.62
	NPI	2.70	1.67	0.35	0.25	0.81	0.63
	NIC	1.95	1.62	0.24	0.24	0.62	0.62
1	PAST	4.36	3.67	0.68	0.43	2.15	0.67
	API	6.10	5.06	0.61	0.50	1.95	0.73
	NPI	6.48	3.88	0.54	0.52	2.16	0.64
	NIC	3.89	3.57	0.69	0.43	1.96	0.68
0.8	PAST	4.40	4.10	0.85	0.46	3.53	0.69
	API	11.29	6.77	1.76	0.61	2.95	0.72
	NPI	10.48	4.20	1.82	0.66	3.77	0.75
	NIC	4.17	3.85	1.19	0.51	3.35	0.70
0.5	PAST	9.04	5.60	1.43	0.71	4.21	0.74
	API	23.07	11.8	2.81	1.07	4.11	0.78
	NPI	23.80	6.32	3.00	1.01	5.58	0.63
	NIC	7.78	5.73	1.22	0.73	3.71	0.72