Title:
OPTICAL MEASUREMENT DEVICE AND MEASUREMENT METHOD
Document Type and Number:
WIPO Patent Application WO/2020/110779
Kind Code:
A1
Abstract:
Provided are an optical measurement device and a measurement method, whereby the effect of nonlinear chirps of a laser are removed, and distance and speed can be accurately measured in FMCW lidar. This optical measurement device is provided with: a frequency-modulated laser; a photodetector; a heterodyne optical system for dividing the output light of the laser in two, one light being a probe light and the other light being a reference light, imparting a frequency shift to either the probe light or the reference light, radiating the probe light to an object, and multiplexing the reference light and the scattered light from the object and causing the multiplexed light to be incident on the photodetector; an IQ detection unit; and a computational processing unit. The IQ detection unit detects an in-phase component I and an orthogonal component Q of a beat signal generated from the photodetector, and the computational processing unit determines the phase and frequency of the beat signal from the in-phase component I and the orthogonal component Q, and executes computation for calculating the speed of the object from the frequency, and/or computation for calculating the distance to the object from the phase.
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Inventors:
TSUCHIDA HIDEMI (JP)
Application Number:
PCT/JP2019/044883
Publication Date:
June 04, 2020
Filing Date:
November 15, 2019
Export Citation:
Assignee:
AIST (JP)
International Classes:
G01S17/34; G01S7/4911; G01S7/4913; G01S7/4915; G01S7/497; G01S17/58
Foreign References:
| JP2006513399A | 2006-04-20 | |||
| JP2000338244A | 2000-12-08 | |||
| JP2018185347A | 2018-11-22 | |||
| JP2017181269A | 2017-10-05 | |||
| JP2003240852A | 2003-08-27 | |||
| JPH01206283A | 1989-08-18 | |||
| JP2013238474A | 2013-11-28 | |||
| JP2018141821A | 2018-09-13 | |||
| US20150071315A1 | 2015-03-12 | |||
| JP2000111312A | 2000-04-18 | |||
| US20100085992A1 | 2010-04-08 | |||
| US20120106579A1 | 2012-05-03 | |||
| US20090135403A1 | 2009-05-28 | |||
| JP2008514910A | 2008-05-08 | |||
| JP2017165940A | 2017-09-21 |
Other References:
TSUCHIDA HIDEMI : "Digital Coherent LiDAR", OPTICAL ALLIANCE, vol. 29, no. 9, September 2018 (2018-09-01), pages 2 - 5, XP009527652, ISSN: 0917-026X
H. TSUCHIDA: "Waveform measurement technique for phase/frequency-modulated lights based on heterodyne interferometry", OPTICS EXPRESS, vol. 25, no. 5, March 2017 (2017-03-01), pages 4793 - 4799, XP055563625, DOI: 10.1364/OE.25.004793
See also references of EP 3889644A4
H. TSUCHIDA: "Waveform measurement technique for phase/frequency-modulated lights based on heterodyne interferometry", OPTICS EXPRESS, vol. 25, no. 5, March 2017 (2017-03-01), pages 4793 - 4799, XP055563625, DOI: 10.1364/OE.25.004793
See also references of EP 3889644A4
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