Real-time Inverse Kinematics of redundant manipulator using a hybrid (analytical and numerical) method

Inverse Kinematics (IK) of redundant manipulators has been an active research problem in the field of robotics for a long time. Many solutions exist, though the focus here is to solve the problem of inverse kinematics (both position and orientation) in real-time for a 7 DOF redundant manipulator with spherical wrist. In other words, a computationally efficient way. The approach taken here attempts to decouple the redundant manipulator at the wrist, thus solving for the first four angles satisfying the wrist position and the last three angles satisfying the End Effector (EE) position and orientation. A hybrid approach of using analytical and numerical methods is undertaken to improve the computational efficiency, and the performance is compared with pure numerical methods. Various paths are generated using this method and tested for performance in terms of accuracy and speed. Finally, simulations on a Motoman IA20 redundant manipulator are shown to display satisfactory performance.