Implementation on a harvesting robot of a sensor-based controller performing a u-turn

Abstract : In this paper we investigate the navigation of a harvesting robot using sensor-based controllers in an orchard. More precisely, we focus our work on the particular u-turn maneuver which allows the mechanical system to move from the current row to the next one. By using sensor-based controllers, the control law is expressed in the sensor space, and the robot does not have to localize itself nor use a global map of the field. The navigation task can then be realized more accurately. This paper reports the implementation of two generic sensor-based controllers. These controllers allow a differential robot to follow spirals around a given point of interest. In this work, we adapt these two controllers to our specific robot (car-like system), before detailing the ROS implementation architecture. Both simulations and experimental results show the interest and the efficiency of our controllers to perform u-turns in an orchard.