Development of an Autonomous Redundant Attitude Determination System for Cubesats

Ricardo O Duarte,Fernando E Torres,Samuel R C Vale,Luiz S Martins-Filho

doi:10.5028/jatm.v12.1166

Ricardo O Duarte, Fernando E Torres + Show 2 more

Open Access

https://doi.org/10.5028/jatm.v12.1166

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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.

Highlights

This paper describes fundamental aspects of the development of a CubeSat nanosatellite attitude determination system with triple redundancy and fault tolerance tools
The SDATF has a planned in-flight test on a mission of the satellite NanosatC-BR2, in the context of a program of the Brazilian National Institute for Space Research (INPE, Instituto Nacional de Pesquisas Espaciais), shown in Fig. 1, where it will fly as an experiment payload, but without responsibility on the attitude determination and control strategy of this CubeSat (Garcia et al 2018; Schuch et al 2014)
The main contribution of this work is the procedure described and detailed in the engineering decisions and the sequence of steps required for the designing of a fault-tolerant scheme for the attitude determination system

Summary

INTRODUCTION

This paper describes fundamental aspects of the development of a CubeSat nanosatellite attitude determination system with triple redundancy and fault tolerance tools. Excessive radiation loads neutralize the logical state of the volatile memory cells of COTS devices This phenomenon is logically perceived as an inversion of a bit of memory, which may affect the application, causing a system lock or a harmful error in the calculated attitude values, compromising system reliability and availability (Wang and Agrawal 2008). Another module is responsible for calculating the geomagnetic field vector using a truncated model from the IGRF12 model (Thébault et al 2015), which will be used together with the vector measured by the magnetometer in the attitude parameter calculation process The inputs to this module are time reference of the model (year), distance from the satellite to the center of the Earth, colatitude and east longitude. More details about the SDATF software, as well as tests, results, and analysis regarding the performance and accuracy of calculations from the adopted mathematical models can be found in Garcia et al (2018)

METHODOLOGY

CONCLUSION