MPC for momentum counter-balanced and zero-impulse contact with a free-spinning satellite

TL;DR

This paper presents a nonlinear MPC framework enabling a servicer satellite to achieve zero-impulse contact with a free-spinning target by controlling two modules and explicitly modeling their dynamics, validated through simulations.

Contribution

The paper introduces a novel MPC approach that explicitly models cross-coupling dynamics for contact control in on-orbit servicing, allowing for constraint enforcement and improved performance.

Findings

MPC effectively maintains spin synchronization and zero-impulse contact.

Simulation results outperform prior control methods.

Controller handles constraints, noise, and contact location changes.

Abstract

In on-orbit robotics, a servicer satellite's ability to make contact with a free-spinning target satellite is essential to completing most on-orbit servicing (OOS) tasks. This manuscript develops a nonlinear model predictive control (MPC) framework that generates feasible controls for a servicer satellite to achieve zero-impulse contact with a free-spinning target satellite. The overall maneuver requires coordination between two separately actuated modules of the servicer satellite: (1) a moment generation module and (2) a manipulation module. We apply MPC to control both modules by explicitly modeling the cross-coupling dynamics between them. We demonstrate that the MPC controller can enforce actuation and state constraints that prior control approaches could not account for. We evaluate the performance of the MPC controller by simulating zero-impulse contact scenarios with a free-spinning target satellite via numerical Monte Carlo (MC) trials and comparing the simulation results with prior control approaches. Our simulation results validate the effectiveness of the MPC controller in maintaining spin synchronization and zero-impulse contact under operation constraints, moving contact location, and observation and actuation noise.