Robust Multi-Event Detection for Pulsed LiDARs

Pulsed light detection and rangings (LiDARs) are widely utilized in various applications such as navigation, robotic, and remote sensing for their high distance resolution, accuracy, and speed. When multiple echoes are received either from interferences or under harsh environmental conditions, conventional pulsed LiDARs fail to extract the distance information out of received signal. To overcome this problem, this paper introduces a multi-event detecting pulsed LiDAR that delivers multiple distance and intensity information when multiple echoes are received. The proposed system comprises an analog front-end (AFE), a timing discriminator with 8 comparators, a multi-event detector, and a time-to-amplitude converter (TAC) for the timing circuit, capable of capturing the distance and intensity information up to four echoes. For quantification, experiments based on multiple echoes with multiple local peaks are conducted using an electrical model generated from real situation. Each event delivers 3-bit intensity information, and the measured distance information with a 10-bit analog-to-digital converter (ADC) exhibits the time resolution of 146.5 ps and the integral nonlinearity (INL) of 1.17 LSB.