Abstract
A selective harvesting robot of crisp head lettuce was made for experiment and the physical properties of lettuce concerned with harvesting were measured. The robot consisted of a vehicle whichtraveledacrosstheridge, arectangularmanipulator, a3-Dvisionsensorfortherecognitionofthelettuce, a harvesting hand, a conveying system and a 32 bit personal-computer. The force required to cut the stem, the holding force of the root against the external side force and the reaction force from the ground at the landing of the hand were measured. Results of the experiment showed that the harvesting method of this robot was suitable and that the ground height could be detected by the reaction force from the ground.
