Abstract: Aiming at the problem of climbing and moving in the process of space on-orbit assembly and maintenance, three elementary cells, i.e. junctional cell, rotational cell and end-effector cell, are proposed based on the concept of cellular space robot (CSR). In addition, in order to intuitively and accurately express the arbitrary configuration and tissue migration process of CSR, the cell migration matrix is obtained by improving the incidence matrix and using the graph theory and topology. Then, three generalized two-bar climbing conditions are summarized by considering the application environment of the truss and the characteristics of CSR. Further, the kinematics model is established by the exponential product formula based on the screw theory. And the climbing gaits are proposed for each climbing condition by employing the principles of consistency, repeatability and non-interference. Finally, the joint torque, energy consumption and the workspace occupied by the end trajectory of CSR with different gaits are analyzed and compared by numerical simulation. The results have important theoretical significance and engineering value for the research of climbing path planning and control mode of space robot.

Key words: Cellular space robot (CSR), Gait analysis, On-orbit climbing, Truss