Abstract
Space situational awareness (SSA) with in-space imaging is one of the top priorities of the U.S. military. The Oculus is a low-cost test bed for nanosatellite in-space imaging technologies. The purpose of the Oculus is to (1) demonstrate vision-based attitude control for tracking resident space objects (RSOs), (2) provide in-space validation of two imaging devices, and (3) train future space-systems engineers through both undergraduate and graduate student research and development. One of the major challenges of creating a low-cost nanosat imaging test bed is the three-axis attitude control system. The Oculus' mission requires two types of attitude control: inertially referenced attitude control and visually referenced attitude control. The visually referenced attitude control, focused upon in this paper, requires precise RSO tracking where both a wide field-of-view imager and a narrow field-of-view imager are used to provide feedback for visual servoing of the spacecraft. Such precise attitude control is implemented using reaction wheels. This paper describes the control strategies used for Oculus' attitude control for visual servoing. Closed-loop performance is illustrated using a dynamic simulation of the spacecraft and a hardware-in-the-loop test bed utilizing a Stewart platform.
Presentation Slides
Nanosatellite Attitude Control System for the Oculus: A Space-Based Imaging Platform for Space Situational Awareness
Space situational awareness (SSA) with in-space imaging is one of the top priorities of the U.S. military. The Oculus is a low-cost test bed for nanosatellite in-space imaging technologies. The purpose of the Oculus is to (1) demonstrate vision-based attitude control for tracking resident space objects (RSOs), (2) provide in-space validation of two imaging devices, and (3) train future space-systems engineers through both undergraduate and graduate student research and development. One of the major challenges of creating a low-cost nanosat imaging test bed is the three-axis attitude control system. The Oculus' mission requires two types of attitude control: inertially referenced attitude control and visually referenced attitude control. The visually referenced attitude control, focused upon in this paper, requires precise RSO tracking where both a wide field-of-view imager and a narrow field-of-view imager are used to provide feedback for visual servoing of the spacecraft. Such precise attitude control is implemented using reaction wheels. This paper describes the control strategies used for Oculus' attitude control for visual servoing. Closed-loop performance is illustrated using a dynamic simulation of the spacecraft and a hardware-in-the-loop test bed utilizing a Stewart platform.
