Manipulator guidance strategies

This thesis presents several different numerical methods for guidance of a mechanical manipulator by simultaneous control of all its joint variables. The emphasis is on avoiding unwanted displacements of the manipulator hand while transfering it from one position to another. Algorithms are developed for computing changes in all the joint variables for a desired small displacement of the manipulator hand. Basically two different types of computer controls are discussed. One is that of guiding the manipulator when the initial and the final positions of the hand are specified. The other is that of controlling the manipulator by means of a computer which receives commands from an external operator. The linear and angular velocities of the manipulator hand are equated to the sums of the linear and angular velocities produced at the manipulator hand by motion about individual joints of the manipulator. For a very small interval of time the same equations generate small changes in the joint variables to give specific small displacements of the manipulator hand. Six linear equations in the six unknown joint variable increments are obtained, for a known small change in position of the manipulator hand. If we know the path by which the manipulator hand should move, intermediate positions of the manipulator hand can be assumed at small intervals and the changes in joint variables necessary for the displacement from one position to the next position can be computed.