Homogeneous Module Unit Morphology Optimization and Design for On-Orbit Services

In order to meet the increasingly complex space missions, this paper designs a homogeneous modular unit form that can be reconfigured into single-chain, two-branch, three-branch and four-branch configurations of space robots. Through the analysis of on-orbit service tasks, the future space robot configuration needs are obtained, and the interface configuration scheme of four interfaces of the modular unit is designed; in order to ensure the motion capability and flexibility of the modular unit, six modular unit degree-of-freedom configurations are proposed, and through the comparative analysis of the motion capability and degree-of-freedom redundancy, and the performance synthesis of the single-chain configuration of the modular unit, such as the mass, degree-of-freedom, workspace and load capacity, the preferred modular unit is selected as the best configuration for the single-chain configuration. Through the comparative analysis of kinematic capability and redundancy of degrees of freedom, as well as the mass, degrees of freedom, working space and load capacity of the single-chain configuration space robot composed of the modular unit, a three-degree-of-freedom configuration scheme is preferred, including two interface degrees of freedom with variable angles and one internal degree of freedom at 45° to the interface degrees of freedom; combined with the analysis of structural load-bearing performance, the design of the sphere of the modular unit is accomplished; and finally, the interface configuration, degrees of freedom configuration and the design of the sphere is synthesized, and a homogenous Modular unit morphology.