Field Test of an Autonomous Cucumber Picking Robot

Abstract

At the Institute of Agricultural and Environmental Engineering (IMAG B.V.) an autonomous harvesting robot for cucumbers was developed and tested in a greenhouse in autumn 2001. Analysis of the harvest process had revealed that at a 2 ha Dutch production facility four robots are needed to replace the skilled human work force during the peak season. Then assuming a success rate of 100%, a harvest cycle might take at most 10 s per cucumber fruit. In this paper the results of the field test of the harvesting robot are reported and analysed in view of the performance criteria mentioned above. Cucumbers ( Cucumis sativus cv. Korinda) were grown in a high-wire cultivation system. In four independent experiments the robot was tested. The average success rate was 74·4%. The majority of failures originated from inaccurate positioning of the end-effector at the stalk of the fruit. It was found to be a great advantage that the system was able to perform several harvest attempts on a single cucumber from different harvest positions of the robot. This improved the success rate considerably. A single successful harvest cycle took 65·2 s per cucumber. Since not all attempts were successful, a cycle time of 124 s per harvested cucumber was measured under practical circumstances. The test confirmed the ability to harvest more than one cucumber using a single set of images which reduced the cycle time of a successful harvest to 56·7 and 53·0 s if two or three cucumbers were harvested. To bridge the gap between the measured performance and the design specifications, future research focuses on improving the success rate, faster hardware and software for image processing and motion planning as well as the reduction of the motion time of the manipulator.