6 research outputs found
Autonomous Robots for Active Removal of Orbital Debris
This paper presents a vision guidance and control method for autonomous
robotic capture and stabilization of orbital objects in a time-critical manner.
The method takes into account various operational and physical constraints,
including ensuring a smooth capture, handling line-of-sight (LOS) obstructions
of the target, and staying within the acceleration, force, and torque limits of
the robot. Our approach involves the development of an optimal control
framework for an eye-to-hand visual servoing method, which integrates two
sequential sub-maneuvers: a pre-capturing maneuver and a post-capturing
maneuver, aimed at achieving the shortest possible capture time. Integrating
both control strategies enables a seamless transition between them, allowing
for real-time switching to the appropriate control system. Moreover, both
controllers are adaptively tuned through vision feedback to account for the
unknown dynamics of the target. The integrated estimation and control
architecture also facilitates fault detection and recovery of the visual
feedback in situations where the feedback is temporarily obstructed. The
experimental results demonstrate the successful execution of pre- and
post-capturing operations on a tumbling and drifting target, despite multiple
operational constraints
Design and Validation of a Novel Mission Framework for the Detumbling of Rotating Space Debris Using a Tether-Net Linkage and Momentum Wheel
As the number of artificial satellites in low Earth orbit (LEO) increases, the probability of collisions between these artificial satellites increases, and so does the need for cost-effective space debris remediation. In this project, we designed and tested a mission framework for the capture and detumbling of space debris. A computer simulation was used to observe the contact dynamics of a net on space debris and its efficacy in capturing tumbling satellites. An experiment was designed and executed to validate the use of a momentum wheel and tether-net linkage to detumble spinning space debris. Through experimentation, it was shown that controlling a piece of tumbling debris with a tether-net connection and momentum wheel is a feasible solution for low-mass debris removal mission
Simultaneous Capture and Detumble of a Resident Space Object by a Free-Flying Spacecraft-Manipulator System
A maneuver to capture and detumble an orbiting space object using a chaser spacecraft equipped with a robotic manipulator is presented. In the proposed maneuver, the capture and detumble objectives are integrated into a unified set of terminal constraints. Terminal constraints on the end-effector's position and velocity ensure a successful capture, and a terminal constraint on the chaser's momenta ensures a post-capture chaser-target system with zero angular momentum. The manipulator motion required to achieve a smooth, impact-free grasp is gradually stopped after capture, equalizing the momenta across all bodies, rigidly connecting the two vehicles, and completing the detumble of the newly formed chaser-target system without further actuation. To guide this maneuver, an optimization-based approach that enforces the capture and detumble terminal constraints, avoids collisions, and satisfies actuation limits is used. The solution to the guidance problem is obtained by solving a collection of convex programming problems, making the proposed guidance approach suitable for onboard implementation and real-time use. This simultaneous capture and detumble maneuver is evaluated through numerical simulations and hardware-in-the-loop experiments. Videos of the numerically simulated and experimentally demonstrated maneuvers are included as Supplementary Material
Robotic Manipulation and Capture in Space: A Survey
Space exploration and exploitation depend on the development of on-orbit robotic capabilities for tasks such as servicing of satellites, removing of orbital debris, or construction and maintenance of orbital assets. Manipulation and capture of objects on-orbit are key enablers for these capabilities. This survey addresses fundamental aspects of manipulation and capture, such as the dynamics of space manipulator systems (SMS), i.e., satellites equipped with manipulators, the contact dynamics between manipulator grippers/payloads and targets, and the methods for identifying
properties of SMSs and their targets. Also, it presents recent work of sensing pose and system states, of motion planning for capturing a target, and of feedback control methods for SMS during motion or interaction tasks. Finally, the paper reviews major ground testing testbeds for capture operations, and several notable missions and technologies developed for capture of targets on-orbit
ET-Class, an Energy Transfer-based Classification of Space Debris Removal Methods and Missions
Space debris is positioned as a fatal problem for current and future space missions.
Many e ective space debris removal methods have been proposed in the
past decade, and several techniques have been either tested on the ground or
in parabolic
ight experiments. Nevertheless, no uncooperative debris has been
removed from any orbit until this moment. Therefore, to expand this research
eld and progress the development of space debris removal technologies, this
paper reviews and compares the existing technologies with past, present, and
future methods and missions. Moreover, since one of the critical problems when
designing space debris removal solutions is how to transfer the energy between
the chaser/de-orbiting kit and target during the rst interaction, this paper proposes
a novel classi cation approach, named ET-Class (Energy Transfer Class).
This classi cation approach provides an energy-based perspective to the space
debris phenomenon by classifying how existing methods dissipate or store energy
during rst contact