Communications – electrical: acoustic wave systems and devices – Signal transducers – Underwater type
Patent
1998-07-13
2000-05-16
Pihulic, Daniel T.
Communications, electrical: acoustic wave systems and devices
Signal transducers
Underwater type
H04R 144
Patent
active
060646306
ABSTRACT:
A system for measuring changes in an environmental parameter such as displacement, velocity, acceleration, or pressure, includes a laser for providing a pulsed, coherent light signal, and an interferometer having a first and second optical legs of unequal optical path lengths. The signal is split into first and second beams that are directed into the first and second optical legs. Either a fixed mirror disposed on a frame or a moving mirror on one side of the proof mass reflects the first beam received at the end of the first optical leg. The frame also suspends a proof mass at opposite ends. An optical pick-off embodied in a movable mirror formed on the proof mass reflects the second beam received from the end of the second optical leg. The proof mass with mirror moves in response to changes in the value of the parameter to be measured. An optical coupler combines the first and second beams after they have been reflected back into their respective optical legs, producing an interference signal, which is detected by an optical detector. The detector generates an electronic signal, which is analyzed in a microcomputer. To compensate for gravity, the proof mass has an asymmetrical profile. As a velocity sensor for seismic measurements, its construction is guided by the mass of the proof mass and spring stiffness of the hinges. Represented mathematically, those terms are selected to minimize the acceleration and displacement components, leaving only the velocity component as a function of the ratio of mass to damping coefficients.
REFERENCES:
patent: 4446543 (1984-05-01), McLandrich et al.
patent: 4799797 (1989-01-01), Huggins
patent: 5218420 (1993-06-01), Asmar
patent: 5448058 (1995-09-01), Arab-Sadeghabadi et al.
patent: 5503285 (1996-04-01), Warren
patent: 5529671 (1996-06-01), Debley et al.
patent: 5675415 (1997-10-01), Akatsu et al.
patent: 5949740 (1999-09-01), Hall
Fersht Samuel N.
Hall David B.
Feng Paul Y.
Litton Systems Inc.
Pihulic Daniel T.
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