Frequency Modulation Control of an FMCW LiDAR Using a Frequency-to-Voltage Converter

Jubong Lee; Jinseo Hong; Kyihwan Park

doi:10.3390/s23104981

Frequency Modulation Control of an FMCW LiDAR Using a Frequency-to-Voltage Converter

Sensors (Basel). 2023 May 22;23(10):4981. doi: 10.3390/s23104981.

Authors

Jubong Lee¹, Jinseo Hong¹, Kyihwan Park¹

Affiliation

¹ Department of Mechanical Engineering, Gwangju Institute of Science and Technology (GIST), 123, Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea.

Abstract

An FMCW LiDAR (frequency-modulated continuous-wave light detection and ranging) is a sensor that can measure distance using optical interference frequency (fb). This sensor has recently attracted interest because it is robust to harsh environmental conditions and sunlight due to the wave properties of the laser. Theoretically, when the frequency of the reference beam is linearly modulated, a constant fb is obtained with respect to the distance. However, when the frequency of the reference beam fails to be linearly modulated, the distance measurement is not accurate. In this work, linear frequency modulation control using frequency detection is proposed to improve the distance accuracy. The FVC (frequency to voltage converting) method is used to measure fb for high-speed frequency modulation control. The experimental results show that linear frequency modulation control using an FVC improves FMCW LiDAR performance in terms of control speed and frequency accuracy.

Keywords: frequency control; frequency-modulated continuous-wave (FMCW) LiDAR; range finding.

Grants and funding

This research was financially supported by the Institute of Civil Military Technology Cooperation funded by the Defense Acquisition Program Administration and Ministry of Trade, Industry and Energy of Korean government under grant No. 21-CM-BD-06.