Method and system for reducing vibration of motion-enabled chairs

Abstract

In a building equipped with a plurality of motion-enabled chairs such as a movie theatre, the vibration of the motion-enabled chairs adds up and may damage the foundation of the building especially at the resonance frequency. The present application describes a system and method for controlling the resulting vibration by introducing an alteration such as a delay or an inversion in the motion signals sent to the motion-enabled chairs. This delay causes the vibration of some motion-enabled chairs to be de-phased from the vibration of the other motion-enabled chairs. Whereby, the intensity (magnitude) of the resulting vibration is reduced. Control of the motion-enabled chairs may be done centrally through a central controller, or locally at selected motion-enabled chairs.

The invention claimed is: 
     
       1. A method for controlling an intensity of a vibration resulting from an addition of the vibrations caused by a set of motion-enabled chairs receiving motion signals that are synchronized, the motion-enabled chairs of the type being motion enabled by actuators between the ground and a seating portion, the method comprising:
 selecting, from the set, one or more motion-enabled chairs to control, with a pair of immediate neighbor motion-enabled chairs comprising one said selected motion-enabled chair and one non-selected motion enabled chair; 
 alteringde-phasing motion signals for the selected motion-enabled chairs relative to the motion signals of the non-selected motion-enabled chairs to de-phase the vibration of the selected motion-enabled chairs from the vibration of the non-selected motion-enabled chairs; 
 sending altered de-phased motion signals to the selected motion-enabled chairs; and 
 sending non-altered motion signals relative to motion signals concurrently sent to the non-selected motion-enabled chairs, thereby reducing the intensity of the vibration resulting from the addition of the vibrations caused by the set of motion-enabled chairs. 
 
     
     
       2. The method of  claim 1 , further comprising selecting a frequency at which the vibration is to be reduced. 
     
     
       3. The method of  claim 2 , wherein the altering de-phasing motion signals comprises applying a delay that allows to motion signals sent to at least one of group of the selected motion-enabled chairs and of the non-selected motion-enabled chairs for a substantial cancellation of the vibration at the selected frequency. 
     
     
       4. The method of  claim 3 , further comprising calculating the delay in accordance with the following equation in which T represents the delay and F represents the selected frequency: T=1/ (2F). 
     
     
       5. The method of  claim 2 , wherein the frequency is selected in a range between 10 Hz and 50 Hz. 
     
     
       6. The method of  claim 2 , wherein the frequency is selected to be the resonance frequency of a building in which the set of motion-enabled chairs is located. 
     
     
       7. The method of  claim 1 , wherein for a given frequency range, the motion signals to the selected motion-enabled chairs is the inverse of the motion signals to the non-selected motion-enabled chairs. 
     
     
       8. The method of  claim 7 , wherein the given frequency range is between 10 Hz and 100 Hz. 
     
     
       9. The method of  claim 1 , further comprising:
 performing the altering de-phasing centrally, at a central transmitter; and 
 sending motion signals to the set of motion-enabled chairs from the central transmitter. 
 
     
     
       10. The method of  claim 1 , wherein the selecting one or more motion-enabled chairs to control comprises dividing the set of motion-enabled chairs into groups of alternating neighboring motion-enabled chairs, wherein each motion-enabled chair will receive motion signals which are altered as compared with motion signals received by its immediate neighbor corresponding to an adjacent motion-enabled chair of the set of motion-enabled chairs. 
     
     
       11. The method of  claim 1 , wherein the selecting one or more motion-enabled chairs to control comprises:
 receiving information relating to an occupant weight from each motion-enabled chair; and 
 dividing the set of motion-enabled chairs in two groups, a first and a second group, based on the weight of each occupant wherein the sum of the weight each occupant in the first group is similar or substantially equal to the sum of the weight of each occupant in the second group. 
 
     
     
       12. The method according to claim 1, wherein sending de-phased motion signals to the selected motion-enabled chairs includes sending non-altered motion signals to the non-selected motion-enabled chairs.