Fault-Tolerant Attitude Determination and Control System Design of Nanosatellite 2

Abstract

Nanosatellite 2 (NS-2) is a science and technology experimental nanosatellite developed by Tsinghua University. Since it was launched, NS-2 has operated properly and has been used as a low-cost, rapid-response satellite platform for on-orbit experiments with microelectromechanical system devices. The design, mathematical model, numerical simulation, and on-orbit telemetry data analysis of the NS-2 attitude determination and control system (ADCS) are presented in this paper. A bias momentum wheel and three-axis magnetic torquers were used and an actuator fault-tolerance control algorithm was proposed. Flight data confirmed that NS-2 ADCS achieved a three-axis stabilized control with an accuracy of 2.5° and an angular rate within .5°/s in each axis, which met the mission requirements. In addition, single event effects were detected during the NS-2 flight, which led to attitude control failures. A simple and practical fault processing method was uploaded to NS-2 ADCS by the ground station to solve this problem. On-orbit operation validated the efficacy of this method. This paper provided reference for the study and design of nanosatellites.