A convex-programming-based guidance algorithm to capture a tumbling object on orbit using a spacecraft equipped with a robotic manipulator

Abstract

An algorithm to guide the capture of a tumbling resident space object by a spacecraft equipped with a robotic manipulator is presented. A solution to the guidance problem is found by solving a collection of convex programming problems. As convex programming offers deterministic convergence properties, this algorithm is suitable for onboard implementation and real-time use. A set of hardware-in-the-loop experiments substantiates this claim. To cast the guidance problem as a collection of convex programming problems, the capture maneuver is divided into two simultaneously occurring submaneuvers: a system-wide translation and an internal re-configuration. These two sub-maneuvers are optimized in two consecutive steps. A sequential convex programming procedure, overcoming the presence of non-convex constraints and nonlinear dynamics, is used on both optimization steps. A proof of convergence is offered for the system-wide translation, while a set of structured heuristics-trust regions-is used for the optimization of the internal re-configuration sub-maneuver. Videos of the numerically simulated and experimentally demonstrated maneuvers are included as supplementary material.

Simultaneous Capture and Detumble of a Resident Space Object by a Free-Flying Spacecraft-Manipulator System

“…In order to cast both sub-maneuver optimization problems as convex programming problems, they are converted to fixedfinal-time problems. As discussed by Virgili-Llop et al (2019), and later shown in section 5, longer final times, t f , reduce, in broad terms, the cost of the maneuver. The user is then prompted to select the longest possible maneuver duration, only limited by the available computing power, or by other factors as communication, or illumination windows.…”

“…A seed to the sequential convex programming procedure is obtained during the first iteration, k = 1, by removing the keep-out zone constraint in Equation (52) from the convex programming problem. The sequential convex programming procedure of the systemwide translation enjoys guaranteed convergence to a locally optimal point-meeting the Karush-Kuhn-Tucker conditions (Boyd and Vandenberghe, 2004)-even if the RSO's shape, S RSO , is non-convex (Virgili-Llop et al, 2019). To obtain these convergence properties replace, during the second iteration k = 2, the RSO shape, S RSO , by its convex hull.…”

“…The simulation and experimental results obtained with the simultaneous capture and detumble maneuvers are compared to the results obtained with our previous capture-only maneuvers (Virgili-Llop et al, 2017b,c, 2019. The simulation scenario as well as the experimental set-up are the same on both cases, allowing for a direct comparison between the two.…”

Dynamic Visual Tracking for Robot Manipulator Using Adaptive Fading Kalman Filter

“…robot tracking control. It is often used for grasping tumbling satellites [6]- [9], and face tracking [10], [11].…”

Neural Network Control of Space Manipulator Based on Dynamic Model and Disturbance Observer

“…In recent years, the aerospace industry has placed increasingly stringent requirements on the performance of space manipulators [1], [2]. If the arms are required to be light in weight, large in end load, and capable of capture maneuvers [3], its own elastic deformation must be large, which may cause system damage because of the resonance of the structure [4]. The arm needs to be redundant for better flexibility and adaptability, which tends to increase flexibility.…”