Development of an Autonomous Redundant Attitude Determination System for Cubesats

ABSTRACT: This work deals with the problem of the design of an autonomous redundant system for the attitude determination of nanosatellites. The system consists of a circuit board equipped with three microcontrollers, a magnetic field sensor in three axes, and complementary commercial-of-the-shelf (COTS) components and connectors to provide data signal exchange the vehicle on-board computer. The main goal of this system, named SDATF (of the acronym in Portuguese Sistema de Determinação de Atitude com Tolerância a Falhas), is to provide autonomously the vehicle attitude from the information collected from the onboard computer (OBC) and the magnetometer. The adopted attitude determination algorithm is based on the well-known QUEST method, and the goal of this system is to get accurate attitude computations to low-orbit CubeSat satellites using COTS electronic components, and to provide highly reliable data and high availability levels using fault tolerance tools to avoid the harmful consequences of spatial radiation and its faults known as single event upsets (SEU). The article presents the general design of the fault-tolerant systems and experimental tests using bit flip injection methodology.

摘要：本研究针对纳卫星姿态确定用自主冗余系统的设计问题展开探讨。该系统搭载一块电路板，集成3个微控制器、一台三轴磁场传感器，以及配套的商用现货（commercial-of-the-shelf, COTS）组件与连接器，用于与星载计算机（onboard computer, OBC）实现数据信号交互。该系统被命名为SDATF（源自葡萄牙语Sistema de Determinação de Atitude com Tolerância a Falhas的首字母缩写），其核心目标是基于星载计算机与磁强计采集的信息，自主解算卫星姿态。本系统采用的姿态确定算法基于经典的QUEST方法，其设计目标为：依托商用现货电子组件，为近地轨道立方体卫星（CubeSat）提供高精度姿态解算；同时借助容错工具规避空间辐射及其引发的单粒子翻转（single event upsets, SEU）故障所带来的有害影响，实现高可靠的数据输出与高可用性水平。本文阐述了该容错系统的总体设计方案，并采用位翻转注入方法开展了相关实验测试。