Method and apparatus for countering vibrations of a platform
First Claim
1. An apparatus for countering vibrations of a platform induced by a mechanically oscillating mass mounted on the platform and driven by a motor comprising:
- motor pick-off means at said motor for providing electrical signals representative of said oscillating mass movements;
a counter mass mechanically coupled to said platform;
oscillator means for mechanically oscillating said counter mass,oscillator pick-off means at said oscillator means for providing signals representative of mechanical movements of said counter mass;
drive input means at said oscillator means for receiving electrical signals to mechanically drive said counter mass;
accelerometer means mounted on said platform for providing electrical signals representative of platform vibrations; and
vibration control means coupled to receive signals from said motor pick-off means, signals from said oscillator pick-off means, and signals from said accelerometer means for providing signals to said drive input means that cause said oscillator means to mechanically drive said counter mass in a manner to induce vibrations of said platform that counter vibrations of said platform induced by oscillations of said oscillating mass.
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Accused Products
Abstract
A dynamic vibration absorber for reducing vibrations of a platform induced by an oscillating mass mounted thereon is provided by mounting a mass of equal mechanical resonant frequency as that of the oscillating mass and oscillating this mass in a manner to establish an equal and opposite vibration of the platform, thereby cancelling the vibrations induced by the oscillating mass. In one embodiment, a signal from the oscillating mass representative of the frequency and amplitude of its mechanical oscillation is phase shifted and utilized as a driving signal to the drive motor of the absorber mass. In another embodiment, electrical signals representative of the platform vibrations are detected to provide phase and amplitude vibration error signals. These error signals are applied to a reference signal coupled to the drive motor of the canceller mass causing the oscillations of the canceller mass to induce vibrations in the platform which counter the vibrations induced by the oscillating mass.
51 Citations
8 Claims
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1. An apparatus for countering vibrations of a platform induced by a mechanically oscillating mass mounted on the platform and driven by a motor comprising:
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motor pick-off means at said motor for providing electrical signals representative of said oscillating mass movements; a counter mass mechanically coupled to said platform; oscillator means for mechanically oscillating said counter mass, oscillator pick-off means at said oscillator means for providing signals representative of mechanical movements of said counter mass; drive input means at said oscillator means for receiving electrical signals to mechanically drive said counter mass; accelerometer means mounted on said platform for providing electrical signals representative of platform vibrations; and vibration control means coupled to receive signals from said motor pick-off means, signals from said oscillator pick-off means, and signals from said accelerometer means for providing signals to said drive input means that cause said oscillator means to mechanically drive said counter mass in a manner to induce vibrations of said platform that counter vibrations of said platform induced by oscillations of said oscillating mass. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method for countering vibrations of a platform induced by motions of a mechanically oscillating mass mounted thereon comprising the steps of:
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mounting a counter mass on said platform; generating a first reference signal in-phase with a signal representative of said motions of said mechanically oscillating mass; generating a second reference signal phase shifted by a predetermined phase angle relative to said motions representative signal; providing a signal representative of vibrations of said platform; synchronously detecting said vibrations representative signal relative to said first and second reference signals to obtain phase and amplitude error signals; processing said phase and amplitude error signals to generate a drive reference signal; and coupling said drive reference signal to motor means coupled to said counter mass for oscillating said counter mass in a manner to induce vibrations of said platform that counter vibrations thereof induced by said oscillating mass.
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Specification