Research on Frequency-Modulated Continuous-Wave Laser Radar Imaging Technology Based on Two-Axis Galvanometer

Frequency-modulated continuous-wave (FMCW) light detection and ranging (LiDAR) has received extensive attention, owing to its high robustness and accuracy, and its extensive applications in the automotive and robotics domains. However, mainstream demonstrations predominantly rely on high performance yet expensive instrumentation, which poses a significant barrier to the widespread manufacturing of FMCW LiDAR systems. In this study, we introduce a novel laser frequency modulation and beat signal processing (LFM-BSP) module realized on a field-programmable gate array (FPGA). The LFM-BSP is distinguished by its full functionality, encompassing all essential electronic operations required by FMCW LiDARs. The LFM-BSP adopts a predistortion approach to generate a linear modulation waveform of nonlinear laser source. Utilizing the waveform, a fully functional, standalone FMCW LiDAR prototype was developed based on the LFM-BSP. The prototype incorporates a two-axis galvanometer to facilitate beam steering. Simultaneous ranging and velocimetry experiments were performed, resulting in the ranging and velocimetry precision of 0.011 m and 0.059 m/s, respectively. Furthermore, the prototype’s capability in 4-D point cloud imaging was evaluated. The results suggest that the LFM-BSP is highly suitable for automotive LiDAR applications, thereby offering a practical framework for the development of next-generation monolithic FMCW LiDAR systems.