An Efficient Inverse Kinematic Method for SSRMS-type Manipulator with Conformal Geometric Algebra

SSRMS-type Manipulator is a typical type of space manipulator featuring 7-degree-of-freedom offset configuration with redundancy characteristic. It is challenging to solve inverse kinematics in high efficiency, make the upmost of redundancy characteristic, and select optimal redundant parameter. This paper proposes an analytical inverse kinematic method, named three-continuous-parallel-Link Direction Vector Parameterization (LDVP), in the theory of Conformal Geometric Algebra. This method employs the direction vector of the axis of parallel Joint 3, Joint 4, and Joint 5 as the parameter, and selects the optimal parameter according to context plan-points in a given trajectory. The process of solving inverse kinematics is divided into two steps, including solving joint positions and joint variables. The average solution time of forward and inverse kinematics is 9.79 us and 0.25 ms respectively. The continuous path tracking experiment verifies that all seven joints changing to pursue the optimal configuration, which makes full use of redundancy characteristic.