Tilt suppression for ultra-low residual motion vibration isolation in gravitational wave detection

Chaotification of Quasi-Zero Stiffness System via Direct Time-delay Feedback Control

“…The fact about the benefits of QZS, has given rise to a growing interest in the study of it. Application of QZS mechanisms range from space field to machinery isolation [6][7][8].…”

Modelling of tuning of an ultra low frequency Roberts Linkage vibration isolator

“…The main control effort is in applying the relatively large forces required to counteract low frequency residual motion which bypass the isolation system below its cut off frequency (a few Hz). Reducing low frequency motion down to nanometre levels for frequencies above 0.2 Hz can greatly reduce the required servo control forces and reduce injected noise [1].…”

Vertical vibration isolator having piecewise‐constant restoring force

“…Development of passive three-dimensional vibration isolators is difficult because of the existence of gravity [2][3][4][5][6]. In horizontal vibration isolation, inserting low-stiffness elements, such as rubber bearings or coil springs, below an isolated object is usually sufficient.…”

“…An example of nonlinear isolators is depicted in Figure 2(a). Zerostiffness or negative-stiffness isolators [2,4,9], Euler column isolators [3,11], and shape memory alloy isolators [10] are representative examples of nonlinear vibration isolators. Nonlinear vibration isolators are designed so that their restoring forces satisfy the following two conditions: (1) the tangent stiffness is large in the small displacement range, and (2) the tangent stiffness is small in the operating range around the static equilibrium position.…”