Dandelion-Picking Legged Robot

Abstract

The emergence of robots in agricultural applications in recent years has radically boosted productivity while decreasing farmer labor and lead times. With the world’s agricultural output growth rates decelerating, a compelling case is made for the advancement of robots in agriculture. The future scope of agricultural robots may lie in using low-degree-of-freedom (low-DoF) multi-legged robots because wheeled or treaded robots suffer from known disadvantages: they are unable to move over rubble and steep or loose ground, and they trample continuous strips of land thereby reducing the viable crop area. Our approach was to show how BigAnt, a low-cost hexapedal robot platform with 1-DoF legs equipped with a RGB-D camera can be used to perform a lawn pest control task of plucking a dandelion. BigAnt plucks dandelions by moving pairs of legs in a manner that translates a cutting fixture attached to its chassis through a concaveshaped dipping trajectory. This dipping motion, which plucks the dandelion, is performed when the RGB-D camera data confirms that the dandelion’s position and the concave-shaped trajectory intersect after approaching it. The results show that BigAnt, with the 0-DoF cutting appendage attached, is sufficient for plucking a dandelion and that other robotic attachments with greater DoFs may be superfluous for this purpose. We show a BigAnt’s ability to maneuver its chassis height and rotation—an important behavior which is used to pick dandelions. This paper also demonstrates that robots with six or more low-DoF legs may hit a sweet-spot for legged robots designed for agricultural applications by providing enough mobility, stability, and low complexity.