CottonSim: Development of an autonomous visual-guided robotic cotton-picking system in the Gazebo

In this study, an autonomous visual-guided robotic cotton-picking system, built on a Clearpath's Husky robot platform and the Cotton-Eye perception system, was developed in the Gazebo robotic simulator. Furthermore, a virtual cotton farm was designed and developed as a Robot Operating System (ROS 1) package to deploy the robotic cotton picker in the Gazebo environment for simulating autonomous field navigation. The navigation was assisted by the map coordinates and an RGB-depth camera, while the ROS navigation algorithm utilized a trained YOLOv8n-seg model for instance segmentation. The model achieved a desired mean Average Precision (mAP) of 85.2%, a recall of 88.9%, and a precision of 93.0% for scene segmentation. The developed ROS navigation packages enabled our robotic cotton-picking system to autonomously navigate through the cotton field using map-based and GPS-based approaches, visually aided by a deep learning-based perception system. The GPS-based navigation approach achieved a 100% completion rate (CR) with a threshold of 5 x 10^-6 degrees, while the map-based navigation approach attained a 96.7% CR with a threshold of 0.25 m. This study establishes a fundamental baseline of simulation for future agricultural robotics and autonomous vehicles in cotton farming and beyond. CottonSim code and data are released to the research community via GitHub: https://github.com/imtheva/CottonSim

Analysis of LiDAR Configurations on Off-road Semantic Segmentation Performance

This paper investigates the impact of LiDAR configuration shifts on the performance of 3D LiDAR point cloud semantic segmentation models, a topic not extensively studied before. We explore the effect of using different LiDAR channels when training and testing a 3D LiDAR point cloud semantic segmentation model, utilizing Cylinder3D for the experiments. A Cylinder3D model is trained and tested on simulated 3D LiDAR point cloud datasets created using the Mississippi State University Autonomous Vehicle Simulator (MAVS) and 32, 64 channel 3D LiDAR point clouds of the RELLIS-3D dataset collected in a real-world off-road environment. Our experimental results demonstrate that sensor and spatial domain shifts significantly impact the performance of LiDAR-based semantic segmentation models. In the absence of spatial domain changes between training and testing, models trained and tested on the same sensor type generally exhibited better performance. Moreover, higher-resolution sensors showed improved performance compared to those with lower-resolution ones. However, results varied when spatial domain changes were present. In some cases, the advantage of a sensor's higher resolution led to better performance both with and without sensor domain shifts. In other instances, the higher resolution resulted in overfitting within a specific domain, causing a lack of generalization capability and decreased performance when tested on data with different sensor configurations.