Truss assembly by space robot and task error recovery via reinforcement learning

This paper addresses an experimental system simulating a free-flying space robot, which has been constructed to study autonomous space robots. The experimental system consists of a space robot model, a frictionless table system, a computer system, and a vision sensor system. The robot model composed of two manipulators and a satellite vehicle can move freely on a two-dimensional planar table without friction by using air-bearings. The robot model has successfully performed the automatic truss structure construction including many jobs, e.g., manipulator berthing, component manipulation, arm trajectory control avoiding collision, assembly considering contact with the environment, etc. Moreover, even if the robot fails in a task planned in advance, the robot accomplishes it by task re-planning through reinforcement learning. The experiment demonstrates the possibility of the automatic construction and the usefulness of space robots.