Certain parameters must be established if citrus harvesting devices are to be designed and used effectively. For this reason the relationships between a citrus tree and a man-positioning device were analyzed in this study in terms of the tree shape, the motions of the machine, and the motions of the operator of the machine. For this discussion, the tree is considered a cylindrical body (when ideally pruned) and the position of any point on its surface or within its boundaries is determined by the "cylindrical curvilinear coordinate system." The coordinates are defined as follows: r = the length of the radius; È = the angular direction of the radial coordinate relative to an arbitrarily selected radial line. The height above ground is the third coordinate, which is designated by Z, and it determines the position of the point relative to the base of the cylinder (fig. 1).

This is a report from the research project on citrus harvest mechanization being conducted in cooperation with the University of California.