Active Vibration Isolation Using Multifunctional Interfaces and Adaptive Digital Controllers.

Abstract

Whenever mechanical vibrations disadvantageously influence sensitive technical systems, the question arises as to whether it is possible to isolate these systems from the adjoining structures. The aim of this investigation is to propose an isolation technology that totally reflects all vibration energy instead of absorbing it. This technique is mainly based on the use of interfaces in which smart actuators, such as magnetostrictive rods, are embedded and on the application of digital real-time controllers that employ adaptive signal processing methods. It is shown that an actively controlled interface acts as a mechanical impedance with arbitrarily adjustable resistive and reactive parts. Different adaptive transversal and recursive filterings are proposed; these are then combined with feedforward and feedback controller concepts. All experiments were conducted assuming the present of harmonic and alternatively broadband disturbances. If the controllability condition can be fulfilled, then the adaptively controlled multifunctional interface affords superb protection for sensitive structural elements from damaging environmental vibrations. Several examples demonstrating the potential usefulness of this method are given.