Multidimensional System Identification and Active Vibration Control of a Piezoelectric-Based Sting System Used in Wind Tunnel

Table 6

Contrast results at different points.

Hammering point	Vibration direction pitch/yaw	Active controller on/off	Damping ratio (%)	Attenuation time (s)	Spectral attenuation (dB/Hz)
30° (A point)	Pitch	Off	0.16	23.09	23.73
		On	1.09	4.89
	Yaw	Off	0.11	20.78	16.37
		On	1.27	4.43
45° (B point)	Pitch	Off	0.10	28.89	18.41
		On	1.27	4.02
	Yaw	Off	0.09	32.37	14.80
		On	1.42	4.44
60° (C point)	Pitch	Off	0.12	35.58	23.26
		On	1.84	4.09
	Yaw	Off	0.08	25.31	22.97
		On	1.21	4.16