MECHATRONICS: THE DEVELOPMENT, ANALYSIS, AND GROUND-BASED DEMONSTRATIONS OF ROBOTIC SPACECRAFT HOPPING WITH A MANIPULATOR

Abstract

Astrobee is a robot designed by Intelligent Robotics Group at NASA Ames Research Center to operate inside of the International Space Station (ISS). The robot has a manipulator that is made up of various mechanical, electronic, and control systems. The designed purpose of the manipulator is to perch Astrobee in an effort to minimize power consumption. The study of grasping dynamics and hopping will lead to more efficient maneuvers that would not require propellant. Can the current Astrobee manipulator perform a propellantless maneuver by using its manipulator?

This thesis reports the construction, design, integration, and testing of a robotic manipulator. A replica model of NASA’s Astrobee manipulator, with 3 degrees of freedom (3-DOF), was constructed at the Spacecraft Research Laboratory (SRL) of Naval Postgraduate School (NPS) using commercial off-the-shelf (COTS) avionics. The control principle of the manipulator was correspondingly developed. Using the Python scripts, the user can easily interact and control the manipulator. Purposely developed test beds enabled to measure the maximum linear force required to remove the manipulator from a perched rail and determine the gripper slip angle of the manipulator from a three-dimensional (3D) printed ISS rail. We found that Astrobee’s manipulator can perform propellantless maneuvers by tossing itself from one ISS rail to another ISS rail.