Remedy scheme and theoretical analysis of joint-angle drift phenomenon for redundant robot manipulators

A quadratic programming (QP)-based method, as a remedy for joint angle drifts, is employed for redundant robot manipulators with physical constraints (e.g., joint-angle limits and joint-velocity limits) considered. By using the QP-based redundancy-resolution scheme, real-time repetitive motion planning (RMP) can be achieved in a drift-free manner. Theoretical analyses based on gradient-descent and neural-dynamic methods are also conducted. Based on analyses, the efficacy of the presented QP-based RMP scheme for redundant manipulators is successfully explained. To demonstrate the effectiveness of the RMP scheme, different kinds of redundant robot manipulators, such as PA10, PUMA560, and a six-link planar robot arm, are tested in order to perform circular and straight line end-effector trajectories by using computer simulations. Both theoretical analysis and computer simulation results have demonstrated the efficacy of the QP-based RMP scheme.