Narrow bandwidth detection of vibration signature using fiber lasers
원문보기
IPC분류정보
국가/구분
United States(US) Patent
등록
국제특허분류(IPC7판)
G01B-009/02
G01H-009/00
출원번호
US-0541609
(2014-11-14)
등록번호
US-9964431
(2018-05-08)
발명자
/ 주소
Moore, Sean
Soh, Daniel B. S.
출원인 / 주소
National Technology & Engineering Solutions of Sandia, LLC
대리인 / 주소
Medley, Behrens & Lewis, LLC
인용정보
피인용 횟수 :
0인용 특허 :
5
초록▼
The various technologies presented herein relate to extracting a portion of each pulse in a series of pulses reflected from a target to facilitate determination of a Doppler-shifted frequency for each pulse and, subsequently, a vibration frequency for the series of pulses. Each pulse can have a squa
The various technologies presented herein relate to extracting a portion of each pulse in a series of pulses reflected from a target to facilitate determination of a Doppler-shifted frequency for each pulse and, subsequently, a vibration frequency for the series of pulses. Each pulse can have a square-wave configuration, whereby each pulse can be time-gated to facilitate discarding the leading edge and the trailing edge (and associated non-linear effects) of each pulse and accordingly, capture of the central portion of the pulse from which the Doppler-shifted frequency, and ultimately, the vibration frequency of the target can be determined. Determination of the vibration velocity facilitates identification of the target being in a state of motion. The plurality of pulses can be formed from a laser beam (e.g., a continuous wave), the laser beam having a narrow bandwidth.
대표청구항▼
1. A system, comprising: a laser that is configured to emit a continuous wave laser beam, wherein an optical reference signal is generated based upon the continuous wave laser beam emitted by the laser;a modulator optically coupled to the laser, wherein the modulator emits a sequence of optical squa
1. A system, comprising: a laser that is configured to emit a continuous wave laser beam, wherein an optical reference signal is generated based upon the continuous wave laser beam emitted by the laser;a modulator optically coupled to the laser, wherein the modulator emits a sequence of optical square pulses based upon the continuous wave laser beam emitted by the laser;an amplifier optically coupled to the modulator, wherein the amplifier emits an amplified optical signal based upon the sequence of square pulses emitted by the modulator;a lens optically coupled to the amplifier, wherein a collimated optical signal is emitted from the lens based upon the amplified optical signal and is directed towards a target, the collimated optical signal includes a sequence of pulses, the sequence of pulses include non-linear effects induced by the modulator and the amplifier;a mixer element that is configured to: mix a received optical signal with the optical reference signal to form an optical heterodyne signal, wherein the received optical signal comprises the sequence of pulses that have reflected off of the target, and further wherein the optical heterodyne signal comprises:a first pulse, the first pulse comprises: a leading edge portion that includes a first non-linear effect in the non-linear effects;a trailing edge portion that includes a second non-linear effect in the non-linear effects; anda central portion, the central portion is located between the leading edge portion and the trailing edge portion;a detector that detects the optical heterodyne signal and outputs an electrical mixed signal based upon optical heterodyne signal, the electrical mixed signal comprises the first pulse; andan analyzer component that is configured to: extract the central portion of the first pulse from the electrical mixed signal, the extraction based at least in part on discarding the leading edge portion of the first pulse and the trailing edge portion of the first pulse;determine a Doppler-shifted frequency from the central portion of the first pulse of the electrical mixed signal;determine, based upon the extracted Doppler-shifted frequency, a frequency of vibration of the vibrating target; andoutput an indication that the vibrating target is vibrating at the frequency of vibration responsive to determining the frequency of vibration of the vibrating target. 2. The system of claim 1, wherein the optical heterodyne signal further comprises: a second pulse, the second pulse comprises: a second leading edge portion that includes a third non-linear effect in the non-linear effects;a second trailing edge portion that includes a fourth non-linear effect in the non-linear effects; anda second central portion, the second central portion is located between the second leading edge portion and the second trailing edge portion, wherein the electrical mixed signal comprises the second pulse, and further wherein the analyzer component is further configured to: extract the second central portion of the second pulse of the electrical mixed signal; anddetermine the frequency of vibration of the vibrating target based upon a determined second Doppler-shifted frequency for the second pulse, wherein the second Doppler-shifted frequency is determined based upon the extracted central portion of the second pulse. 3. The system of claim 2, wherein the analyzer component is further configured to determine the vibration frequency of the vibrating target based at least in part on a first velocity determined for the first pulse and a second velocity determined for the second pulse. 4. The system of claim 1, wherein the sequence of pulses are radar pulses. 5. The system of claim 1, wherein a transmitter comprises the laser, the modulator, the amplifier, and the lens. 6. The system of claim 1, further comprising a beam splitter optically positioned between the laser and the modulator, the beam splitter receives the continuous wave laser beam, wherein the beam splitter emits a first optical beam that is received by the modulator and a second optical beam, wherein the optical reference signal is based upon the second optical beam. 7. The system of claim 1, wherein the continuous wave laser beam is a narrow-band laser beam. 8. The system of claim 7, wherein the narrow-band laser beam has a wavelength of between 500 nanometers and 2 micrometers. 9. The system of claim 8, wherein the narrow-band laser beam has a bandwidth of less than 100 kHz. 10. The system of claim 1, wherein the analyzer component is configured to extract the central portion of the first pulse of the electrical mixed signal when the target is in motion. 11. The system of claim 10, wherein the analyzer component is configured to determine that the vibrating target is an idling vehicle based upon the frequency of vibration. 12. The system of claim 1, wherein the mixer element, the detector, and the analyzer component are included in a same device. 13. The system of claim 6, further comprising an acousto-optic filter optically coupled to the beam splitter, wherein the optical reference signal is based upon an output of the acousto-optic filter.
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이 특허에 인용된 특허 (5)
Engel Simon L. (Mountain View CA) McFall Robert A. (East Peoria IL), Apparatus for modulating a high energy beam.
Paranto Joseph N. (Albuquerque NM) Liskow Dean H. S. (Albuquerque NM) Minden Monica L. (Calabasas CA), Random pulse burst range-resolved doppler laser radar.
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