INSTANTANEOUS KINEMATICS AND JOINT DISPLACEMENT ANALYSIS OF FULLY-PARALLEL ROBOTIC DEVICES (FLORIDA SHOULDER, SPECIAL CONFIGURATIONS)

State of the art industrial robot manipulators typically feature a serial sequence of simple joints. Serial robotic devices have been the subject of much study. The same cannot be said for parallel devices where two or more serially connected subchains join an end-effector platform to ground. Such devices do exist and are beginning to be studied in industry as potential robot manipulators. This dissertation presents a fundamental study of these alternative devices to provide a basic understanding and to assess some of the practical aspects.; A type synthesis of parallel robotic devices is performed using an algorithm based on Franke's condensed notation. This is followed by a discussion of potential robotic applications.; This dissertation essentially covers two major topics: instantaneous kinematics and joint displacement analysis of fully-parallel devices. Firstly, two novel procedures for determining the instantaneous motion of the end-effector platform of fully-parallel devices using the theory of screws are presented and an important theorem is derived--for any parallel device, the twist representing the instantaneous motion of the end-effector platform is equal to the sum of its partial twists. Equally important, a characteristic matrix equation is derived and used to describe and categorize various geometrical phenomena called "special configurations" which are by no means fully understood. Six different types of special configurations are tabulated. By the way of example special configurations of the planar Florida Shoulder are studied in detail and numerical results are provided. Secondly, the joint displacement analysis of the planar Florida Shoulder is presented. This is followed by presenting the reverse joint displacement analysis of the well known Stewart Platform and also of the R-P-SP spatial robotic device with three subchains connecting the end-effector platform. Numerical examples are presented for each device. Computer programs for the displacment analysis are listed in the appendices.