# Spacecraft Attitude Control with Nonconvex Constraints: An Explicit Reference Governor Approach

## TL;DR

This paper presents a new spacecraft attitude control method that ensures constraint satisfaction and stability using a two-layer approach with explicit reference governor techniques, addressing actuator saturation and exclusion zones.

## Contribution

It introduces an explicit reference governor approach for spacecraft attitude control that guarantees constraint satisfaction with nonconvex constraints and asymptotic stability.

## Key findings

- Effective constraint enforcement demonstrated through numerical examples
- Guarantees of stability and constraint satisfaction achieved
- Applicable to systems with actuator saturation and exclusion zones

## Abstract

This paper introduces a novel attitude controller for spacecraft subject to actuator saturation and multiple exclusion cone constraints. The proposed solution relies on a two-layer approach where the first layer prestabilizes the system dynamics whereas the second layer enforces constraint satisfaction by suitably manipulating the reference of the prestabilized system. In particular, constraint satisfaction is guaranteed by taking advantage of set invariance properties, whereas asymptotic convergence is achieved by implementing a non-conservative navigation field which is devoid of undesired stagnation points. Multiple numerical examples illustrate the good behavior of the proposed scheme.