US 12,442,924 B2
Signal processing device, signal processing method, and lidar device
Junia Nomura, Tokyo (JP); Masaharu Imaki, Tokyo (JP); Shumpei Kameyama, Tokyo (JP); and Yusuke Ito, Tokyo (JP)
Assigned to MITSUBISHI ELECTRIC CORPORATION, Tokyo (JP)
Filed by Mitsubishi Electric Corporation, Tokyo (JP)
Filed on Jul. 27, 2023, as Appl. No. 18/227,013.
Application 18/227,013 is a continuation of application No. PCT/JP2021/007241, filed on Feb. 26, 2021.
Prior Publication US 2023/0375706 A1, Nov. 23, 2023
Int. Cl. G01S 17/58 (2006.01)
CPC G01S 17/58 (2013.01) 8 Claims
OG exemplary drawing
 
1. A signal processing device that calculates, as a moving speed of each of a plurality of observation targets present in a space, a relative speed of each of the observation targets with respect to a lidar device, wherein
a plurality of light pulses having different optical frequencies are generated from a laser beam output from a light source, each of the light pulses radiated to the space and then scattered by each of the observation targets is received as scattered light, and multiplexed light of the scattered light and the laser beam is detected, and
the signal processing device comprises:
a Doppler frequency calculator to calculate a Doppler frequency that is due to movement of each of the observation targets; and
a speed calculator to calculate a relative speed of each of the observation targets from each of the Doppler frequency calculated by the Doppler frequency calculator, wherein
the Doppler frequency calculator includes:
an optical frequency corrector to correct an optical frequency of each of the multiplexed lights associated with the observation targets, on a basis of a frequency difference between an optical frequency of one light pulse and an optical frequency of the remaining light pulse among the plurality of generated light pulses; and
a frequency calculation processor to calculate a Doppler frequency included in an optical frequency of each of the scattered light from an optical frequency of each of the multiplexed light corrected by the optical frequency corrector and an optical frequency of each of the generated light pulses.