Design of an Under-Actuated Mechanism for Collecting and Cutting Crop Samples in Precision Agriculture

Automating the processes of sampling and harvesting in precision agriculture is essential to expand the range of potential application scenarios. In this regard, this paper presents the design and development of an under-actuated device for grapevine harvesting and sampling. The tool is intended to be part of a set of tools from which a rover for precision agriculture can choose to perform various tasks. The tool presented in this paper is designed specifically for the gripper of a 7 d.o.f. robotic arm equipped by the rover Agri.Q, a service robot designed for agriculture. However, the design of the tool can be adapted to work with other robotic arm grippers. In this research, the gripper output contact forces and the required cut forces are experimentally measured to clearly define the design requirements of the tool. Then, the functional design of the system is described and a kinematic model of the mechanism is presented. Finally, the tool prototype is presented and tested with green peduncles ranging from 2 mm to 6 mm in diameter.