Feedforward control of a vibration isolation system for disturbance suppression

Vibration isolation system combining zero-power magnetic suspension with springs

“…One of the fundamental control strategies is to provide feedback regarding the absolute velocity of the isolation table-a process often referred to as skyhook damping (Fuller et al, 1996). The performance limitations of passive-type vibration isolation systems can be effectively overcome by two-degrees-of-freedom control (Miyazaki et al, 1994;Yasuda et al, 1996;Yoshioka et al, 2001). While various other control methods, such as state feedback (Miyazaki et al, 1994), H 1 (Watanabe et al, 1996), feedforward (Mohamed et al, 2005), repetitive (Daley et al, 2006) and active acceleration (Zhu et al, 2006) control have also been applied, most active vibration isolation systems use high-performance sensors, such as servo-type accelerometers, to detect the vibration of an isolation table with high sensitivity in a low-frequency domain.…”

Development of a Six-Axis Hybrid Vibration Isolation System Using Zero-Power Control

“…It is well known that an active vibration control technique can satisfy the demands for isolating floor vibrations as well as for rejecting the effect of direct disturbances [1]- [3]. Although conventional passive technique can separately be used, with low cost, to isolate floor vibration and to suppress the onboard-generated vibrations using different types of suspensions.…”

Modelling and control of hybrid vibration isolation system for high-precision equipment

“…The significant periodic movement of stages may induce the direct periodic disturbance to the system. Feedback control may not achieve sufficiently high speed responses because of delay intrinsically contained in its strategy and its own bandwidth limit [5]. Therefore the feedforward compensation is needed to attenuate the direct disturbance.…”