Multi-Domain Coincidence Processing and Memory Architecture for Real-Time Geiger Mode LiDAR

Abstract

Geiger-Mode LiDAR is a powerful time-of-flight range sensing technology that enables rapid, wide area three-dimensional mapping with the unique capability of foliage penetration. These sensor arrays produce very high data rates on the order of 5 Gbps, requiring high-bandwidth motion compensation and coincidence processing to correlate the range returns and locate the modes in three-dimensional space. This paper proposes a multi-processor system architecture and memory management techniques for performing orientation-compensated histogram generation and peak detection to filter the LiDAR data stream, removing redundancy and spurious outputs. The multi-processor design, employing custom logic in concert with multiple CPUs, offers a reduction in system size, weight, and power [SWaP] by several orders of magnitude when compared to existing CPU-only real time coincidence processor designs. Behavioral simulations and hardware-in-the-loop testing offer partial proof of functionality for this design, which is capable of reducing the data rate by a factor of approximately 300 with output in the form of Cartesian coordinates, which can be directly integrated into a point cloud data structure for viewing. This promising result warrants further development work on LiDAR system designs incorporating these concepts.