The conflicting nature of vibration and shock isolation requirements, necessitates design compromises in realizing mounting schemes for systems subject to both vibration and shock perturbations. To avoid making such design compromises, one needs to pursue active and semi-active isolation solutions.
One approach to active isolation is combining an active scheme with a traditional passive isolation system. In such an approach a passive, but adjustable mount (such as an air spring) is used in mounting the machine. The control scheme takes advantage of the adjustability of air as the mounting medium and through the use of controls does on-demand adjustment of the parameters (damping and stiffness) of the isolation system. Such a system uses no additional actuators to exercise the control. Such active system can switch its parameters, promptly, from being an ideal vibration isolator to an ideal shock isolator, depending on the nature of the instantaneous perturbation (vibration or shock). More