Field-VIO: Stereo Visual-Inertial Odometry Based on Quantitative Windows in Agricultural Open Fields

In agricultural open fields, accurate autonomous localization of robots requires long-term data correlation to reduce cumulative error. Our article presents a Stereo Visual- Inertial Odometry (VIO) system based on ORB-SLAM3 to address the malfunction of the Loop Closure Detection (LCD) methods in this environment. In this method, we first propose a concept of quantitative windows to describe the robot’s trajectory along the crop rows. We design a driving state quantification algorithm and accurately separate the quanti- tative windows between the crop rows. Our system constructs spatial constraints according to the parallelism between the quantitative windows. We apply an anomaly correction method to maintain the constructed parallel matching relationship and implement holistic pose correction for keyframes within abnormal quantitative windows. Our system demonstrated excellent performance over long distances in experiments on the Rosario dataset, verifying its effectiveness in reducing cumulative positioning error in agricultural open fields.