Frequency-modulated continuous-wave (FMCW) LiDAR is an absolute-distance measurement technology with the advantages of high-precision, non-cooperative target measurement capabilities and the ability to measure distance and speed simultaneously. However, the existing range extraction method for FMCW LiDAR is associated with problems, such as requiring a high sample rate and dispersion mismatch. Here, we propose and demonstrate a dynamic range extraction method based on an FM nonlinear kernel function, which improves measurement accuracy without the use of a long auxiliary interferometer (as is required for the traditional method), reduces the influence of dispersion mismatch and the Doppler effect caused by target movement and can simultaneously measure the target motion information dynamically, with a lower measurement error than that of the existing range extraction method under the same conditions.

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Frequency-modulated continuous wave (FMCW) laser interferometry is an ideal large-scale absolute distance measurement method. It has advantages of high precision and noncooperative target measurement capability, with no blind spot for ranging. To meet the requirements of high-precision, high-speed 3D topography measurement technologies, a faster measurement speed of FMCW LiDAR at each measurement point is required. To solve the shortcomings of the existing technology, a real-time high-precision hardware solution method (including but not limited to FPGA and GPU) for lidar beat frequency signals is provided here based on hardware multiplier arrays to reduce lidar beat frequency signal processing time and to save energy and resource consumption during processing. A high-speed FPGA architecture was also designed for the frequency-modulated continuous wave lidar range extraction algorithm. The whole algorithm was designed and implemented in real time based on the principle of full-pipelines and parallelism. The results show that the processing speed of the FPGA system is faster than that of current top-performing software implementations.

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