Orchard Navigation of UGVs Using UAV-LiDAR-Based Semantic Costmap

This study proposes a costmap generation method for orchard navigation that integrates both semantic and geometric information from point clouds acquired using unmanned aerial vehicle (UAV)-based light detection and ranging (LiDAR). Conventional approaches often rely on aerial imagery, which cannot capture the internal structures of tree crowns, or on ground-based mapping, which is inefficient and typically limited to height-based costmaps. In this study, orchard-scale three-dimensional point clouds were acquired using UAV-LiDAR, and RandLA-Net was applied for semantic segmentation to classify tree trunks, crowns, and ground. Based on this classification, we constructed a semantic costmap that incorporates obstacle height and shape and integrated it into the Navigation2 framework for unmanned ground vehicle (UGV) navigation. Simulation experiments (20 trials) achieved an 85% success rate, significantly higher than that of conventional methods (60%–65%). Furthermore, field experiments (15 trials) achieved a 93% success rate, demonstrating safe and efficient path planning even in densely canopied environments.