VIBRATION SENSOR AND A SYSTEM TO ISOLATE VIBRATIONS

• US 20110126630A1
• Filed: 05/14/2009
• Published: 06/02/2011
• Est. Priority Date: 05/15/2008
• Status: Abandoned Application

• Current Assignee: Nederlandse Organisatie Voor Toegepast-Natuurwetenschappelijk Onderzoek Tno
• Original Assignee: Nederlandse Organisatie Vorre Toegepast- Natuurwetenschappelijk Onderzoek Tno.
• Inventors: Fraanje, Petrus Rufus, Rijnveld, Niek, van den Dool, Teunis Cornelis
• Application Number:
  US12/992,892
• Publication Number:
  US 20110126630A1
• Time in Patent Office: Days
• US Class Current: 73/654
• CPC Class Codes: F16F 15/02 Suppression of vibrations of non-rotating, e.g. reciprocating systems; Suppression of vibrations of rotating systems by use of members not moving with the rotating systems F16F15/005 takes precedence ; layered products B32B; suppression of vibration in ships B63; relieving load on bearings, using magnetic means F16C39/06
• CPC Class Codes: F16F 7/1005 characterised by active control of the mass

Abstract

A vibration sensor comprises a reference mass, a resilient element supporting the reference mass, and a base supporting the resilient element, and further comprises a displacement sensor for determining the distance between the reference mass and the base. In accordance with the invention the vibration sensor comprises an actuator that is situated between the resilient element and the base, a second displacement sensor, and a controller for providing an output signal to the actuator.

Claims

1. A vibration sensor comprising a reference mass, a resilient element supporting the reference mass, a base, and a first displacement sensor for determining a distance between the reference mass and the base and for providing an ouput signal indicative of said distance, wherein the vibration sensor further comprises an actuator situated between the resilient element and the base, a second displacement sensor for determining a length of the resilient element and for producing a corresponding distance signal, and a controller for providing an output signal to the actuator in response to the distance signal.

2. A vibration sensor according to claim 1, wherein the second displacement sensor is arranged for determining a distance between the reference mass and the actuator.

3. A vibration sensor according to claim 1, wherein at least one of the displacement sensors is a sensor for measuring an absolute distance.

4. A vibration sensor according to claim 1, wherein the actuator is a piezo-electric actuator.

5. A vibration sensor according to claim 1, wherein the controller comprises a low pass filter, a lead filter, a lag filter and an amplifier arranged in series.

6. A vibration sensor according to claim 1, wherein the resilient element is a mechanical spring.

7. An active vibration isolation system comprising a vibration sensor according to claim 1.

8. An active vibration isolation system according to claim 7, wherein the vibration sensor is placed on a payload that has to be isolated.

9. An active vibration isolation system according to claim 7 wherein the system further comprises a second actuator for displacing the payload relative to a bearing, and a second controller for providing a payload displacement signal to the second actuator.