Experimental Study of Active Vibration Control of Planar 3-RRR Flexible Parallel Robots Mechanism

Table 1

PSD value of the first-order mode frequency.

	PSD1	PSD2	PSD3
Uncontrolled	29.58	20.67	17.92
Scheme  1	27.37 (−7.47%)	14.61 (−29.32%)	10.34 (−42.3%)
Scheme  2	27.08 (−8.45%)	20.65 (−0.1%)	17.83 (−0.5%)
Scheme  3	29.6 (+0.06%)	14.14 (−31.59%)	17.89 (−0.17%)
Scheme  4	29.44 (−0.47%)	20.25 (−2.03%)	10.16 (−43.3%)

Note: PSD1 is the PSD value of the vibration signal of sensor 1 with respect to the first-order mode frequency; PSD2 is the PSD value of the vibration signal of sensor 2 with respect to the first-order mode frequency; PSD3 is the PSD value of the vibration signal of sensor 3 with respect to the first-order mode frequency.