A partitioned redundancy management scheme for an eight-joint revolute manipulator

摘要

A partitioned redundancy management approach is developed for a class of eight-joint manipulators with four-axis intersecting wrists. Segmenting the excess degrees of freedom at the wrist simplifies the inverse kinematics problem substantially and allows different and often competing schemes to be used for controlling the motion of the arm. In the upper arm, the roll angle of the shoulder–elbow–wrist plane is controlled directly. In the wrist, the spare joint is used to minimize the instantaneous joint velocities. In addition, the partitioning scheme substantially reduces the number of singularities that can be encountered by the arm and thus actively avoided. A new four-axis “skew” wrist design is also introduced which doubles the workspace size of the traditional orthogonal design while retaining the ability to avoid singularities. Simulations are used to illustrate the redundancy management approach on the dexterous manipulator for a submersible robotic vehicle. © 2000 John Wiley & Sons, Inc.