A Reconfigurable Robot with Telescopic Links for In-Space Servicing

Compacting the arms of a space manipulator in its designated launch volume has been a difficult design problem in several robotic missions not only for in-orbit servicing but also for planetary exploration. This paper presents a conceptual design for space manipulators with lockable telescopic links that allows the arms to change their length as well as the twist angles. Each cylindrical telescopic link is equipped with a built-in brake mechanism which is normally locked, but the lock can be released whenever the kinematic parameters are to be changed. Since the telescopic links do not have any actuator, the robot reduces its number of degrees of freedom by constraining the motion of its end-effector in order to be able to control the values of the length and the twist angles. The control system which autonomously realizes the configuration change in addition to autonomous calibration of the manipulator after every configuration change are fully developed in this work. Several space mission examples which can benefit from such a reconfigurable robot are discussed.