Optimal Trajectory Planning for Orbital Robot Rendezvous and Docking

TL;DR

This paper presents a nonlinear optimization-based trajectory planning method for safe, close-range rendezvous with tumbling space debris, incorporating a dynamic keep-out sphere and a practical thruster control strategy.

Contribution

It introduces an adaptive keep-out sphere and a control approach for discrete thrusters, enhancing safety and practicality in orbital debris rendezvous missions.

Findings

Effective trajectory planning with dynamic safety margins

Successful control strategy for discrete thrusters

Potential for safer debris removal operations

Abstract

Approaching a tumbling target safely is a critical challenge in space debris removal missions utilizing robotic manipulators onboard servicing satellites. In this work, we propose a trajectory planning method based on nonlinear optimization for a close-range rendezvous to bring a free-floating, rotating debris object in a two-dimensional plane into the manipulator's workspace, as a preliminary step for its capture. The proposed method introduces a dynamic keep-out sphere that adapts depending on the approach conditions, allowing for closer and safer access to the target. Furthermore, a control strategy is developed to reproduce the optimized trajectory using discrete ON/OFF thrusters, considering practical implementation constraints.