The first robotic cutting mechanism, or “end effector,” for a fully automated, computerized pruning system for modern apple orchards has been designed by a Penn State research team. This might be an early step in the creation of a technology aimed at easing challenges facing tree fruit growers.
Researcher Long He, assistant professor of agricultural and biological engineering, claims that automated or mechanical pruning could largely solve the pressing problems of both preharvest production costs and the tree fruit industry’s struggle with increasing labor costs and a limited labor pool.
In the U.S. the tree fruit industry contributes one-fourth, or $18 billion, of all specialty crop production, and apples are one of the most valuable. Pruning is a necessary cultivation technique that affects fruit quality, quantity and the efficacy of pest control, and it is still largely dependent on manual labor.
In the study conducted at Penn State’s Fruit Research and Extension Center, researchers first measured branch-cutting force with a sensor attached to manual pruners to provide information for the end effector design. An end effector is a device or tool that's connected to the end of a robot arm where the hand would be.
The pruning end effector was developed using two rotary motors, a pneumatic cylinder and a pair of shear-blade pruning cutters. A three-directional linear manipulator was built to house the end effector and move it to the targeted pruning locations.