Double spiraliform path planning and tracking for agricultural mobile robotics: A modeling and simulation study

Abstract

This research presents a comprehensive study on the design and implementation of a robust trajectory tracking system for autonomous agricultural robots. It introduces a unified kinematic model that integrates different rolling structures, facilitating performance across various robotic designs. The novel path planning method utilizes double spiraliform tracks to enhance movement efficiency in complex agricultural settings and generate flexible fields in terms of scale, orientation, and location, providing reference trajectory models. A sliding mode controller is developed to manage nonlinear dynamics and discontinuous input references, ensuring stability and precision during operation. The sliding approach was compared against four controllers: a linear feedback controller, a state-space feedback controller, a proportional controller, and a proportional–integral controller. The evaluation of accuracy and precision with respect to the input reference model showed similar performances across the controllers. However, the sliding approach proved superior when inputting nonlinear reference and discontinuous external perturbations, producing chattering metric errors averaging 0.94 m and mean = 0.012 m, for components, respectively A Lyapunov analysis confirmed the sliding mode controller stability during path tracking nonlinear dynamics, handling unpredictable operational conditions. Numerical simulations validated the controller’s effectiveness, showcasing its robustness against external disturbances and its ability to maintain stability and precision during operation.