High-Resolution Non-Line-of-Sight Tracking By Comb-Calibrated FMCW LiDAR

Abstract

Non-line-of-sight (NLOS) tracking has the ability to detect and locate moving objects which are hidden from the direct line of sight. It has a number of potential applications in autonomous driving, security and search-and-rescue scenarios. The current approaches for NLOS tracking mostly rely on time-of-flight (ToF) LiDAR, mmWave radar or RGB camera. However, they may either have a limited resolution or need accumulation to detect the position and velocity. Here a real-time comb-calibrated frequency-modulated-continuous-wave (FMCW) LiDAR system is proposed and demonstrated for high-resolution NLOS tracking. A 3D positioning (and velocity) accuracy of 2 mm (and 2 mm s⁻¹) and the capability to realize real-time multi-object tracking are demonstrated in experiment. Importantly, the FMCW-LiDAR approach can obtain the position and velocity of multiple objects in a snapshot, thus resolving the problems of measurement origin uncertainty, false alarm, and detection overlap in multi-target tracking. The proposed approach shows significant potential for practical applications in NLOS detection and sensing.