Parallel Processing of Point Cloud Ground Segmentation for Mechanical and Solid-State LiDARs

In this study, we introduce a novel parallel processing framework for real-time point cloud ground segmentation on FPGA platforms, aimed at adapting LiDAR algorithms to the evolving landscape from mechanical to solid-state LiDAR (SSL) technologies. Focusing on the ground segmentation task, we explore parallel processing techniques on existing approaches and adapt them to real-world SSL data handling. We validated frame-segmentation based parallel processing methods using point-based, voxel-based, and range-image-based ground segmentation approaches on the SemanticKITTI dataset based on mechanical LiDAR. The results revealed the superior performance and robustness of the range-image method, especially in its resilience to slicing. Further, utilizing a custom dataset from our self-built Camera-SSLSS equipment, we examined regular SSL data frames and validated the effectiveness of our parallel approach for SSL sensor. Additionally, our pioneering implementation of range-image ground segmentation on FPGA for SSL sensors demonstrated significant processing speed improvements and resource efficiency, achieving processing rates up to 50.3 times faster than conventional CPU setups. These findings underscore the potential of parallel processing strategies to significantly enhance LiDAR technologies for advanced perception tasks in autonomous systems. Post-publication, both the data and the code will be made available on GitHub.

Stream-Based Ground Segmentation for Real-Time LiDAR Point Cloud Processing on FPGA

This paper presents a novel and fast approach for ground plane segmentation in a LiDAR point cloud, specifically optimized for processing speed and hardware efficiency on FPGA hardware platforms. Our approach leverages a channel-based segmentation method with an advanced angular data repair technique and a cross-eight-way flood-fill algorithm. This innovative approach significantly reduces the number of iterations while ensuring the high accuracy of the segmented ground plane, which makes the stream-based hardware implementation possible. To validate the proposed approach, we conducted extensive experiments on the SemanticKITTI dataset. We introduced a bird's-eye view (BEV) evaluation metric tailored for the area representation of LiDAR segmentation tasks. Our method demonstrated superior performance in terms of BEV areas when compared to the existing approaches. Moreover, we presented an optimized hardware architecture targeted on a Zynq-7000 FPGA, compatible with LiDARs of various channel densities, i.e., 32, 64, and 128 channels. Our FPGA implementation operating at 160 MHz significantly outperforms the traditional computing platforms, which is 12 to 25 times faster than the CPU-based solutions and up to 6 times faster than the GPU-based solution, in addition to the benefit of low power consumption.