A Model Predictive Control Based Magnetorquer-only Attitude Control Approach for a Small Satellite

Magnetic attitude control is an essential topic in attitude determination and control (ADC) studies as it can be used as the main or backup attitude control method in different scenarios. The magnetic actuation system is advantageous for its low cost, reliability, and ease of implementation when the pointing accuracy requirement is not high. The major issue in using magnetorques for attitude control is that it provides controllability over a period. In this study, a magnetic attitude control algorithm is designed for a low Earth orbit sun-synchronous small satellite by using a model predictive control approach which is an advanced control technique that generates control input using the system model to predict the future behavior of the system. The control algorithm is integrated into the overall ADC algorithm and the complete algorithm is tested via simulations. The simulation results show that the three-axis attitude control can be achieved with an accuracy of below 10 deg in around 10 orbits from the tumbling status of the satellite.