Cyclic control of redundatn robot under constraint with the self-motion method

To meet the requirements due to the existing constraints in addition to the main task, it is possible to use, for the redundant robots, the self-motion (internal motion of joints). However, this solution can lead to a loss of the motion cyclicity in joints space. In this work, three methods are compared which ensure the conservation of the movement cyclicity. These latter are based respectively on the Lagrangian one (to improve selfmotion solution), a compliance function (to improve inverse jacobian solution) and the last is a combination of both methods. We consider the control of a redundant robot which carries out a trajectory tacking in operational space with the constraints due to the position and velocity limits of joints. Also, the proposed methods are tested in the case of the 3 DOF planar robots deduced from the PUMA 560. The obtained results show that the two methods alone can ensure the motion cyclicity meanwhile the combined method is more efficient.