The computer-aided structural design of robotic manipulators

Abstract

The research carried out in this work involves the kinematic and dynamic analyses of the robotic manipulators. The kinematic analysis includes the displacement analysis of the planar and spatial mechanisms as well as the velocity and acceleration analyses. In the dynamic analysis, the variation of the natural frequencies and the dynamic condensation techniques have been studied. -- The displacement analysis of the open and closed-loop systems have been carried out using the optimization principles and the modified Newton-Raphson technique. The velocity and acceleration analyses have been divided into two categories: in the first one, the number of unknowns are either greater or less than three and in the second one they are equal to three. The first type is solved using the modified Newton-Raphson technique whereas the second type solved by simultaneous solution of the equations. -- To carry out the dynamic analysis, the equations of motion have been obtained using the finite element analysis. The system matrices for the robotic manipulators are also dependent on the angular velocities and angular acceleration. Several new methods of obtaining the matrix of direction cosines needed to represent the orientation of the local axes with respect to the global axes, are discussed. The natural frequencies as a result of the variation of several design parameters have been obtained. Finally, a comparative study on the two types of dynamic condensation schemes have been carried out using a machine tool spindle and a robotic manipulator as examples.