Adjustable vibration isolation and tuned mass damper systems

Abstract

Particular embodiments relate generally to vibration isolation systems and tuned mass dampers. In one embodiment, a vibration isolation system may include a supporting base, an isolated mass, at least one air mount, a control valve, a compressed air supply, and a supervisory controller. The air mount is positioned between the isolated mass and the supporting base. The control valve is pneumatically coupled to the air mount, the compressed air supply and the atmosphere, and is operable to adjust a flow of air to and from the air mount. The supervisory controller receives a mass relative height signal, a mass relative velocity signal, and a mass relative acceleration feedback signal corresponding to a relative acceleration of the isolated mass or a pressure of the air mount. The supervisory controller may control the control valve such that a mounting height, a damping and a stiffness level of the air mount are a function of the mass relative height signal, the mass relative velocity signal, the mass relative acceleration feedback signal, or combinations thereof.

1 - 11 . (canceled) 
     
     
         12 . A vibration isolation system comprising a supporting base, an isolated mass, at least one air mount, a control valve, a compressed air supply, and a supervisory controller, wherein:
 the air mount is positioned between the isolated mass and the supporting base;   the control valve is pneumatically coupled to the air mount, the compressed air supply, and atmosphere, and is operable to adjust a flow of air to and from the air mount; and   the supervisory controller is operable to receive a mass relative height signal corresponding to a relative vertical displacement of the mass with respect to the supporting base or an air pressure of the air mount, a mass relative velocity signal corresponding to a relative velocity of the mass with respect to the supporting base, and a mass relative acceleration signal corresponding to a relative acceleration of the isolated mass with respect to the supporting base or the air pressure of the air mount, and programmed to control the control valve such that a mounting height of the air mount, a damping level of the air mount, and a stiffness level of the air mount are a function of the mass relative height signal, the mass relative velocity signal, the mass relative acceleration feedback signal, or combinations thereof.   
     
     
         13 . A vibration isolation system as claimed in  claim 12  wherein the supervisory controller is programmed to control the control valve such that:
 the air mount operates at a relatively damped level when a shock excitation is present in the isolated mass or the supporting base; 
 the air mount operates at a relatively underdamped level when a relatively high frequency vibration is present in the mass or the supporting base; 
 the air mount operates at a relatively stiff level when a shock excitation is present in the mass; 
 the air mount operates at a relatively soft level when a relatively low frequency vibration is present in the mass; and 
 the air mount operates at a relatively soft level when a shock excitation is present in the supporting base, a relatively low frequency vibration is present in the supporting base, or a combination thereof. 
 
     
     
         14 . A vibration isolation system as claimed in  claim 13  wherein the air mount operates at a damping level and a stiffness level to isolate shock excitation when both shock excitation and vibration are present in the isolated mass, the supporting base or a combination thereof. 
     
     
         15 . A vibration isolation system as claimed in  claim 12  wherein:
 the control valve is responsive to a drive signal such that a magnitude and sign of the drive signal adjusts the flow of air to and from the air mount; 
 the supervisory controller comprises:
 a mass height feedback loop configured to generate a mass height feedback output signal by applying a mass height feedback gain G h  to the mass height error signal; 
 a mass velocity feedback loop configured to generate a mass velocity output signal by applying a mass velocity feedback gain G v  to the mass relative velocity signal; and 
 a mass acceleration feedback loop configured to generate a mass acceleration feedback output signal by applying a mass acceleration feedback gain G a  to the mass relative acceleration signal; and 
 
 the supervisory controller is operable to generate the drive signal by summing the mass height feedback output signal, the mass velocity feedback output signal, and the acceleration feedback output signal, and apply the drive signal to the control valve to adjust the mounting height of the air mount, the damping level of the air mount and the stiffness level of the air mount. 
 
     
     
         16 . A vibration isolation system as claimed in  claim 12  further comprising:
 a displacement sensor coupled to the isolated mass or a pressure sensor coupled to the air mount configured to generate the mass relative height signal; and 
 a first accelerometer coupled to the isolated mass configured to generate a first acceleration signal and a second accelerometer coupled to supporting base configured to generate a second acceleration signal, wherein the mass relative acceleration signal is a difference between the first and second acceleration signals. 
 
     
     
         17 . A vibration isolation system as claimed in  claim 16  wherein the vibration isolation system further comprises a velocity sensor coupled to the isolated mass and configured to generate the mass relative velocity signal, or a velocity estimator coupled to the isolated mass operable to receive the mass relative acceleration signal and the mass relative height signal and provide the mass relative velocity signal at a velocity estimator output. 
     
     
         18 . A vibration isolation system comprising a supporting base, an isolated mass, at least one main air mount, at least one main control valve, at least one stiffness air mount, at least one stiffness control valve, and a compressed air supply, wherein:
 the main air mount is pneumatically coupled to the main control valve and is operable to provide a flow of air to and from the main air mount;   the stiffness air mount is pneumatically coupled to the stiffness control valve and is operable to provide a flow of air to and from the stiffness air mount;   the main air mount and the stiffness air mount are positioned between the isolated mass and the supporting base;   the stiffness air mount is operable to enter an engaged state wherein the stiffness air mount is engaged with the isolated mass, and a disengaged state wherein the stiffness air mount is disengaged from the isolated mass; and   the vibration isolation system is configured to receive an engagement signal, engage the stiffness air mount with the isolated mass in accordance with the engagement signal, vary an air pressure in the stiffness air mount in accordance with the engagement signal, and disengage the stiffness air mount in accordance with the engagement signal.   
     
     
         19 . A vibration isolation system as claimed in  claim 18  wherein the vibration isolation system is configured to disengage the stiffness air mount in accordance with the engagement signal by controlling the control valve to deflate the stiffness air mount and provide a vacuum to the stiffness air mount. 
     
     
         20 . A vibration isolation system as claimed in  claim 18  wherein the stiffness air mount is configured to mechanically pull back from the isolated mass upon deflation. 
     
     
         21 . A vibration isolation system as claimed in  claim 18  wherein the engagement signal corresponds with a motion of the isolated mass, a motion of the supporting base, or a combination thereof. 
     
     
         22 . A vibration isolation system as claimed in  claim 18  wherein:
 the at least one stiffness air mount comprises a first stiffness air mount and a second stiffness air mount; 
 the main air mount, the first stiffness air mount and the second stiffness air mount are configured as convoluted air springs; 
 the main air mount is positioned between the isolated mass and the supporting base in a main vibration direction; 
 the first stiffness air mount is positioned between the isolated mass and the supporting base in a first lateral direction; and 
 the second stiffness air mount is positioned between the isolated mass and the supporting base in a second lateral direction. 
 
     
     
         23 . A vibration isolation system as claimed in  claim 18  wherein the vibration isolation system comprises a main air mount and a stiffness air mount at each corner of the isolated mass. 
     
     
         24 . A vibration isolation system as claimed in  claim 18  wherein:
 the main air mount is configured as a convoluted air spring and is positioned between the isolated mass and the supporting base in a main vibration direction; and 
 the stiffness air mount is configured as a pneumatic air spring and is positioned between the isolated mass and the supporting base in the main vibration direction. 
 
     
     
         25 . A vibration isolation system as claimed in  claim 24  wherein the vibration isolation system further comprises one or more additional stiffness air mounts.