Compliant Plant Exploration for Agricultural Procedures With a Collaborative Robot

Abstract

This letter presents a compliant exploration framework based on a collaborative robot Franka Panda that builds a 3D plant stem model. The model is built for agricultural plant treatment procedures without external sensors, as contact forces are estimated from joint torques and robot's dynamic and kinematic model. By devising an impedance-based exploratory control algorithm capable of following an unknown shape, while being provided with only a general direction in which to explore, we eliminate the need for a precise position controller. Our approach is validated through experiments with several mock-up plant stems, showing that the proposed framework is capable of building a satisfactory 3D model of a plant. The method is evaluated against the ground truth model, and compared to the state of the art approach based on an industrial manipulator with external sensors.