Development of a parallel link manipulator

Describes a parallel link manipulator built for application to an underground excavation task. The specifications of both the manipulator and the controller are explained. The kinematics of the manipulator are analyzed to develop a control algorithm. The workspace of the manipulator is analyzed by simulation. The singularity problem for parallel manipulators is discussed. Since it is difficult to derive the forward kinematics in the closed form, two alternatives are proposed: a serial measuring link and a linearization method using the Jacobian. The former is used to get the precise location and orientation of the end effector for real-time control and the latter gives a good estimation of the end effector motion in off-line motion planning. >