Chapter 56 — Robotics in Agriculture and Forestry

A robot for harvesting sweet peppers in greenhouses

This video shows robotic harvesting of sweet-pepper fruits in a commercial Dutch greenhouse in June 2014. The base of the robot consists of two carrier modules. On the first are located the manipulator (nine degrees-of-freedom), specifically developed for this project, the control electronics and the computers. On the sensor carrier module, two 5 megapixel color cameras (comprising a small baseline stereo setup) and a time-of-flight (TOF) camera are installed. Around the sensors, a light grid is placed to illuminate the scene. The sensor system is mounted on a linear motorized slide and can be horizontally moved in and out of the workspace of the manipulator. Machine-vision software localizes ripe fruits and obstacles in 3D. Two different types of end-effectors were designed and tested. The fin-ray gripper features a combined grip and cut mechanism. This end-effector first grips the fruit and after that the peduncle of the fruit is cut. The lip-type end-effector first stabilizes the fruit using a suction cup after which two rings enclose the fruit and cut the peduncle of the fruit. Both end-effectors have a miniature RGB and a TOF camera for refining the fruit position and to determine the fruit pose. This robot demonstrator is one of the results of the EU project CROPS, Clever Robots for Crops (www.crops-robots.eu).
Jochen Hemming, Wouter Bac, Bart van Tuijl, Ruud Barth, Eldert van Henten, Jan Bontsema, Erik Pekkeriet
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