Practical analytical inverse kinematic approach for 7-DOF space manipulators with joint and attitude limits

Dongsheng Zhou, Lu Ji, Qiang Zhang, Xiaopeng Wei

Abstract: In this study, we propose a practical approach for calculating the analytical inverse kinematic solution for a seven-degrees of freedom (7-DOF) space manipulator with joint and attitude limits. Instead of utilizing traditional velocity-based approaches that limit the ranges of joints by calculating the velocity-level Jacobian matrix, we propose a position-based approach for evaluating the ranges of feasible inverse kinematic solutions. We then search for the optimal solution, which is estimated based on the disturbance that acts on the base of the manipulator to obtain the final solution. First, the concept of the redundancy of manipulators is defined and each joint is parameterized by the redundancy. Second, how the joint limits affect this redundancy is discussed. Third, a practical approach (include the objective function that the author needs to minimize) is proposed for dealing with the inverse kinematic problem of 7-DOF manipulators. Finally, the validity of this approach is verified by numerical simulation.