Planning and Control of Robot Orientational Path

A new geometric method for the planning and control of the orientation of robot's end-effector along a prescribed translational path is presented. To eliminate the influence of geometric changes along a translational path and to be able to predict the orientation, the proposed method plans rotational paths with respect to a natural local coordinate frame formed by three unit vectors, namely, the tangent, normal and binomial vectors, defined by the geometry of the prescribed translational path. In addition to planning the rotational path, a motion control strategy is developed to maintain the desired rotational speed or acceleration of the end-effector. The presented examples show practical relevance of the proposed rotational trajectory planning method.