FINITE TWIST MAPPING AND ITS APPLICATION TO PLANAR SERIAL MANIPULATORS WITH REVOLUTE JOINTS

This paper reviews a method of representing the finite twist motion of a rigid body, and applies this concept to the problem of describing t he motion capabilities of planar serial manipulators. In particular, t his finite twist representation describes the position and orientation of the end-effector link relative to a defined reference position and orientation. The transformations associated with the joint motions ar e used to investigate the range of end-effector motion, including the effects of limits of joint travel. The finite twist representations ar e then extracted from such transformations and presented in an image s pace so that the motion of the manipulator is fully characterized. Fur ther, the reachable and dexterous workspaces are predicted by the same general means. Examples of planar serial manipulators with two (RR) a nd three revolute (RRR) joints are given to illustrate the approach.