ABSTRACT
The air spring systems just discussed are certainly active systems since they are feedback control systems and use an external power source (the compressed air supply) to achieve their desired performance. Pneumatic servosystems of this type are, however, too slow to be effective in counteracting the floor vibrations and/or exciting force inputs which cause payload vibration. These servosystems are only useful in maintaining the payload level and keeping the system natural frequency constant for different payload masses. If we want to use feedback principles to dynamically fight against vibration, we must use hardware that is capable of much faster response. Various forms of electromechanical vibration isolation systems have been developed for this purpose. These can be used alone or are sometimes "piggybacked" on top of pneumatic isolators.
