Dynamic modeling and analysis of an in-space cable-driven manipulator for on-orbit servicing

In-space cable-driven manipulators exhibit several advantages, such as a large range of motion, high dexterity, and lightweight structure. However, kinematic and dynamic analysis play an essential role in designing a cable-driven manipulator. In this paper, the kinematic analysis of a type of cable-driven manipulator is performed, and a motion planning scheme is conducted to actuate this manipulator. Moreover, a flexible multi-body dynamic model of a cable-driven manipulator considering the frictional contact between the cables and pulleys is established. To describe properties such as flexibility, vibration, and variable length of the cable, this paper utilizes reduced-order beam elements of the Absolute Nodal Coordinates Formulation (ANCF) in Arbitrary Lagrangian Eulerian (ALE) framework. Additionally, a virtual element is introduced to model the contact segment in the cable-pulley system. A tension decay factor is employed to account for the friction in the contact segment. To validate the proposed method, a semi-analytical model based on D'Alembert’s principle is established. Cross-verification is performed to validate the accuracy of both models. The model is further applied to simulate the rotation of the cable-driven manipulator with different structural parameters and frictional factors. The results from the analyses provide valuable guidance for the design and motion control of the in-space cable-driven manipulator. Finally, a prototype of a single module is manufactured and tested. Ground experiments are carried out to verify the kinematic and dynamic models.