Transformation Mathematics of a Mobile Robot Work Center

A mobile robot work center has been constructed for the Navy by Southwest Research Institute for the purpose of re moving rivets from airplane wings during overhaul and re pair. This system is referred to as a deriveter. Two features of the robotic deriveter system required the derivation of new mathematical relationships. The first feature is the computa tion of the transformation relating the robot and wing refer ence frames to each other based on measurements made by the robot, which is mounted on a movable vehicle. Four methods for finding this transformation are presented and the applicability of each to the deriveter is discussed. The second feature is that of positioning the end-effector, tool cen terline so that it is perpendicular to the wing surface, with the tool center point at a given offset from the wing based on measurements made by the robot end effector.