Variable-Horizon Guidance for Autonomous Rendezvous and Docking to a Tumbling Target

TL;DR

This paper introduces a novel variable-horizon guidance method for autonomous spacecraft rendezvous and docking with tumbling targets, efficiently solving a complex nonconvex optimization problem through linear programming techniques.

Contribution

It presents a new approach that uses a variable planning horizon and linear programming to effectively solve the nonlinear trajectory optimization problem.

Findings

Successfully generated optimal trajectories for docking with a tumbling target.

Reduced computational cost compared to traditional nonlinear solvers.

Demonstrated effectiveness on EnviSat spacecraft simulation.

Abstract

In this paper, the trajectory planning problem for autonomous rendezvous and docking between a controlled spacecraft and a tumbling target is addressed. The use of a variable planning horizon is proposed in order to construct an appropriate maneuver plan, within an optimization-based framework. The involved optimization problem is nonconvex and features nonlinear constraints. The main contribution is to show that such problem can be tackled effectively by solving a finite number of linear programs. To this aim, a specifically conceived horizon search algorithm is employed in combination with a polytopic constraint approximation technique. The resulting guidance scheme provides the ability to identify favourable docking configurations, by exploiting the time-varying nature of the optimization problem endpoint. Simulation results involving the capture of the nonoperational EnviSat spacecraft indicate that the method is able to generate optimal trajectories at a fraction of the computational cost incurred by a state-of-the-art nonlinear solver.