🤖 AI Summary
This study addresses the limitations of conventional agricultural robot path-tracking approaches, which typically control only the vehicle’s center of mass while neglecting the spatial pose and dynamic effects of attached implements—often compromising accuracy and risking crop damage. Focusing on Ackermann-steered agricultural robots, this work proposes a closed-form model predictive control method that explicitly incorporates lateral slip and lever-arm effects by modeling the implement as a rigid offset point. The approach enables high-precision tracking of the implement’s working point while maintaining computational efficiency for real-time operation. Experimental results demonstrate substantial improvements in field performance: compared to state-of-the-art controllers, median tracking errors are reduced by 24%–56%, and peak errors during curvature transitions decrease by up to 70%, significantly enhancing operational safety in complex agricultural environments.
📝 Abstract
Robots are increasingly being deployed in agriculture to support sustainable practices and improve productivity. They offer strong potential to enable precise, efficient, and environmentally friendly operations. However, most existing path-following controllers focus solely on the robot's center of motion and neglect the spatial footprint and dynamics of attached implements. In practice, implements such as mechanical weeders or spring-tine cultivators are often large, rigidly mounted, and directly interacting with crops and soil; ignoring their position can degrade tracking performance and increase the risk of crop damage. To address this limitation, we propose a closed-form predictive control strategy extending the approach introduced in [1]. The method is developed specifically for Ackermann-type agricultural vehicles and explicitly models the implement as a rigid offset point, while accounting for lateral slip and lever-arm effects. The approach is benchmarked against state-of-the-art baseline controllers, including a reactive geometric method, a reactive backstepping method, and a model-based predictive scheme. Real-world agricultural experiments with two different implements show that the proposed method reduces the median tracking error by 24% to 56%, and decreases peak errors during curvature transitions by up to 70%. These improvements translate into enhanced operational safety, particularly in scenarios where the implement operates in close proximity to crop rows.