Coordinate transformations and programming for small revolute-coordinate robots

Abstract

In attempting to program a revolute-coordinate (arm-and-elbow) robot directly from data about required end-effector positions expressed in spatial (x, y, z) coordinates, users of smaller ‘teaching’ robots face a lack of information about the necessary transformation from spatial coordinates to joint coordinates. The purpose of this paper is to provide that information in the form of simplified trigonometrical expressions which, while not representing a completely general solution to all possible cases, nevertheless provide the solution for a large class of tasks to which small robots are commonly applied. Application of the algorithm to a Smart Arms 6E robot is described, and a summary of the interfacing and programming requirements is included.