Optimal Trajectory Planning for Orbital Robot Rendezvous and Docking

2025-12-26

AI Summary

This paper addresses the challenge of safe, close-proximity rendezvous for servicing satellites capturing freely floating, two-dimensional tumbling space debris—specifically under actuator constraints (discrete thruster ON/OFF operation) and dynamic obstacle environments. Method: We propose an optimal trajectory planning and robust control framework tailored for robotic-arm capture. A coupled target–servicer dynamics model is formulated; an adaptive dynamic collision-avoidance sphere mechanism enables real-time obstacle avoidance; and a nonlinear optimization-based impulsive trajectory planner, integrated with a robust tracking controller, ensures precise delivery of the rotating target into the manipulator’s workspace. Results: Experimental validation demonstrates significant improvements in approach accuracy and safety: minimum safe distance is reduced by 32%, capture window duration increases by 45%, and overall mission feasibility and robustness are substantially enhanced under realistic operational uncertainties.

Technology Category

• Intelligent Robots: Manipulation
• Planning, Routing, and Scheduling: Replanning and Plan Repair
• Search and Optimization: Mixed Discrete/Continuous Search

Application Category

• Responsible Web: Human-perceived consequences of algorithmic deployment on the web
• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• Security and Privacy: Tracking, profiling, and countermeasures against them

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.

Problem

• Planning safe orbital robot trajectories for debris capture
• Optimizing close-range rendezvous with tumbling space targets
• Implementing control for thrusters to follow planned paths

Innovation

• Nonlinear optimization for close-range rendezvous trajectory planning
• Dynamic keep-out sphere adapting to approach conditions
• Control strategy using discrete ON/OFF thrusters for trajectory reproduction