A Kinematically Redundant (6+1)-Dof Hybrid Parallel Robot for Delicate Physical Environment and Robot Interaction (pERI)

A novel kinematically redundant 6+1-degree-of- freedom (dof) spatial hybrid parallel robot is proposed. Each of the two legs of the robot has a fully parallel structure to minimize the moving inertia by mounting actuators on the base. The kinematic model of each leg and overall robot architecture is developed based on the constraint conditions of the robot geometry. The singularity analysis of legs 1 and 2 reveals that their serial and parallel singularities can be avoided by properly dimensioning the robot and sacrificing the edge of the workspace. In addition, it is shown that the type II (parallel) singularities can be completely avoided, resulting in a large orientational workspace. The gripping mechanism is then introduced which is operated by the redundant degree of freedom of the robot. A CAD model of the robot and a computer animation are provided to demonstrate the positioning and orientation of the robot and the gripping function.