Zero-Gravity Simulation with Attitude Control and Automatic Balancing

This thesis documents the design, construction, and testing of a neutral-buoyancy robot to be used as a zero-gravity simulator for space robotics research in the Laboratory for Space Teleoperation and Robotics (LSTAR). The robot was primarily designed to support the development of autonomous, vision-based vehicle navigation and control. In a secondary role, it was also designed to support research of operator-vehicle visual interfaces to provide verification of results obtained from virtual-environment experimentation. The robot design was based on neutral-buoyancy robots previously built by the Space Systems Laboratory. Several design improvements were undertaken to remedy problems discovered during past neutral-buoyancy testing. The most notable of these improvements is the design of an automatic balancing subsystem. An attitude control system was implemented to demonstrate the controllability of the robot. The performance of the control system was evaluated through the measurement of system response to the application of step inputs. The control system was found to be fast and powerful