Microsatellite Attitude Determination and Control Subsystem Design and Implementation: Software-in-the-Loop Approach

Ho-Nien Shou

doi:10.1155/2014/904708

Abstract

The paper describes the development of a microsatellite attitude determination and control subsystem (ADCS) and verification of its functionality by software-in-the-loop (SIL) method. The role of ADCS is to provide attitude control functions, including the de-tumbling and stabilizing the satellite angular velocity, and as well as estimating the orbit and attitude information during the satellite operation. In Taiwan, Air Force Institute of Technology (AFIT), dedicating for students to design experimental low earth orbit micro-satellite, called AFITsat. For AFITsat, the operation of the ADCS consists of three modes which are initialization mode, detumbling mode, and normal mode, respectively. During the initialization mode, ADCS collects the early orbit measurement data from various sensors so that the data can be downlinked to the ground station for further analysis. As particularly emphasized in this paper, during the detumbling mode, ADCS implements the thrusters in plus-wide modulation control method to decrease the satellite angular velocity. ADCS provides the attitude determination function for the estimation of the satellite state, during normal mode. The three modes of microsatellite adopted Kalman filter algorithm estimate microsatellite attitude. This paper will discuss using the SIL validation ADCS function and verify its feasibility.

Highlights

The purpose of the satellite project is to establish indigenous capability for spacecraft development, including the design, analysis, manufacturing, assembly, integration, tests, and inspace validation
The paper is relevant to the design and implement of the attitude determination and control subsystem (ADCS) for a microsatellite simulation in software
In designing the ADCS, the satellite environment, dynamics, control, and estimation functions are simulated through a SIL simulation endeavor

Summary

Introduction

The purpose of the satellite project is to establish indigenous capability for spacecraft development, including the design, analysis, manufacturing, assembly, integration, tests, and inspace validation. The paper is relevant to the design and implement of the attitude determination and control subsystem (ADCS) for a microsatellite simulation in software. Micro-satellite Attitude Determination and Control Subsystem Design and Implementation: Software-in-the-loop Approach. To support the satellite mission, the ADCS is required to provide the in-orbit attitude control and determination functions. In designing the ADCS, the satellite environment, dynamics, control, and estimation functions are simulated through a SIL simulation endeavor. SIL simulation is a virtual platform which can provide the simulation of the satellite working environment, satellite dynamics, and ADCS instruments including attitude sensors and actuators. PIL enables the testing of the actual control and estimation codes running on the microcontroller in the verification environment. The paper is concluded with the summary and some remarks for the future research are depicted

ADCS Design

Attitude Control

Kalman Filter

The SIL Test of Microsatellite ADCS

Conclusions