Space robots are an effective resource for astronauts working in a dangerous space environment. This paper proposes and implements a system to validate the performance of robot movement in space. A humanoid robot was designed with a vision-based self-calibration and navigation system. In addition, a path planning method was proposed to minimize joint torque. Simple gravity-compensation equipment with active and passive mechanisms was proposed. However, the flexible connection required for free movement between the robot and the gravity-compensation equipment meant that the space robot was likely to vibrate when moving. In order to address this challenge, a new hybrid force-position controller with joint torque feedforward was proposed. This controller was based on the system dynamics model with a particular focus on joint dynamics. Experimental test results validated the system design and methodology, showing that the humanoid space robot could move sufficiently using simple gravity-compensation equipment.

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Using space stations for a large number of observation, exploration, and research is a necessary way to fully develop space technology. It is a necessary means of space experiment to install the extravehicular experimental load by using the load plate. However, the extravehicular environment is full of danger, which poses a threat to the health and even safety of astronauts. Using robots to replace astronauts to complete this task can effectively reduce the threat to astronauts. Aiming at the problem that the configurations of existing space robots have difficulty in balancing the contradiction between complexity and dexterity, our previous work proposes a 12-DOF 3-arm robot and preliminarily explores the feasibility of its large-scale ability. This paper focus on the 8-DOF redundant dexterous manipulator composed of 2 of the robot arms. In view of the difficulties in solving the inverse kinematics of the redundant manipulator, the challenges of complex environmental lighting, and difficulties of matching multiple groups of holes and pins in the load plate assembly task, the research on the autonomous assembly of the load plate is carried out. The main work is as follows: (a) A variable D-H parameter inverse kinematics solution method is proposed, which lays a foundation for humanoid dexterous operation planning of the robot. (b) An autonomous operation method based on visual guidance and variable parameter admittance control is proposed. Finally, the safety and robustness of the robot in the autonomous assembly of the load plate with multipins and holes are successfully verified by experiments.

Maintaining stability is a significant challenge during the control of a robot astronaut while climbing with humanlike dual-arm action in a space station. This challenge is caused by conflicting force generated by dynamic internal forces in the closed chain during dual-arm climbing. In general, an impedance controller is suitable for solving this problem. However, the conflicting force in the rigid closed chain is stored in the virtual spring of the impedance controller (especially in microgravity), where even small disturbances cause a significant change in robot astronaut movements. As such, it is difficult to select suitable control parameters for the stable climbing of a robot astronaut. This paper proposes an adaptive algorithm to optimize the impedance controller parameters. This eliminates conflicting force disturbances, with one arm in compliance with the motion of the other. It provides scope for achieving stable motion without the need for precise control parameters. Finally, the stability of the proposed algorithm is demonstrated by Lyapunov theory using a robot called ASTROBOT. The experimental results show the validity of the proposed algorithm.