Modified Configuration Control With Potential Field for Inverse Kinematic Solution of Redundant Manipulator

Abstract

This article proposes a method with a potential field for optimizing the configuration of angular velocity to avoid joint limitations while following the desired orientation of the end effector of a redundant manipulator. In the practical application of inverse kinematics for redundant manipulators, the most important tasks include avoiding collisions and maintaining the workspace. The null space projection method has been used to solve inverse kinematics from redundancy with the additional task of avoiding angle limitations. However, because such tasks vary, they can interfere in maintaining the desired orientation and following the end effector s desired trajectory. Furthermore, because of the use of a pseudoinverse matrix, singular value decomposition is applied to each calculation to avoid singularity; however, this increases the calculation time. To resolve these problems, the proposed method optimizes the error between the desired and actual tasks using the potential field method and angular limitation value function. This renders the proposed method more intuitive for assigning additional tasks to the manipulator while avoiding joint limitations and obstacles in real time. In the simulation, the calculation time using the proposed method is confirmed to be shorter than that of the conventional method. Finally, the proposed approach is verified to be capable of avoiding obstacles and angle limitations when the method is applied to a manipulator with seven degrees of freedom in the experiment.