Automatic mushroom harvester development

This paper describes research which demonstrates that robotic harvesting of high-quality mushrooms, for the fresh market, is entirely feasible. The work was undertaken in two stages. First, systems capable of automatic mushroom location, sizing, selection, picking, trimming, conveying and transfer were conceived and implemented on a specially designed laboratory development rig. Once the sub-systems and integrated control software had been proven, the second stage of producing a pilot robotic harvester, based on these ideas, was carried out. Machine vision and image analysis algorithms were used for mushroom location and sizing. A separate strategy algorithm was written for selecting the most appropriate mushroom picking order. Overall system control was achieved using a single 486 DX33 MHz personal computer. Separate suction cup end-effecters were produced for picking in confined (less than 300 mm) or open headroom spaces. New delicate handling techniques for conveying, trimming and transferring mushrooms using flexible fingers, high-speed knives and a padded pneumatic gripper system, were developed. Both the laboratory rig and the pilot harvester were evaluated using imitation mushrooms constructed from dental plaster and a wide range of cultivated Agaricus bisporus mushrooms. In trials on a commercial farm, an average of over 80% of the mushroom pick attempts were successful. (C) 2001 Silsoe Research Institute.