A Closed-Form Solution for the Inverse Kinematics of the 2<i>n</i>-DOF Hyper-Redundant Manipulator Based on General Spherical Joint

• Main Authors: Ya’nan Lou, Pengkun Quan, Haoyu Lin, Dongbo Wei, Shichun Di
• Format: Article
• Language: English
• Published: MDPI AG 2021-01-01
• Series: Applied Sciences
• Subjects: closed-form inverse kinematics; general spherical joint; distance-based; hyper-redundant manipulator
• Online Access: https://www.mdpi.com/2076-3417/11/3/1277

This paper presents a closed-form inverse kinematics solution for the -degree of freedom (DOF) hyper-redundant serial manipulator with identical universal joints (UJs). The proposed algorithm is based on a novel concept named as general spherical joint (GSJ). In this work, these universal joints are modeled as general spherical joints through introducing a virtual revolution between two adjacent universal joints. This virtual revolution acts as the third revolute DOF of the general spherical joint. Remarkably, the proposed general spherical joint can also realize the decoupling of position and orientation just as the spherical wrist. Further, based on this, the universal joint angles can be solved if all of the positions of the general spherical joints are known. The position of a general spherical joint can be determined by using three distances between this unknown general spherical joint and another three known ones. Finally, a closed-form solution for the whole manipulator is solved by applying the inverse kinematics of single general spherical joint section using these positions. Simulations are developed to verify the validity of the proposed closed-form inverse kinematics model.