Attitude Determination and Control System for Nadir Pointing and Detumbling Using Magnetorquer for 1U Bolivian Cubesat

Abstract

A CubeSat represents a low-cost solution for developing countries like Bolivia due to its small size and weight. However, particularly for the Bolivian territory there are no previous studies regarding testing the performance of regular attitude controllers applied to CubeSats. For this reason, this paper delves into the attitude control scheme and estimation system design for a 1U CubeSat aimed at Earth observation considering a maximum disturbance torque in Bolivian territory using gyroscopes, sun sensors, magnetorquers as actuators and magnetometers as attitude sensors. The stabilization approach for Nadir earth pointing is based on the quaternion position of CubeSat concerning an orbit reference frame and B-dot controller for CubeSat Detumbling. Furthermore, the CubeSat orbit was modelled as a circular orbit where a simplified earth’s magnetic field was used for control laws. Additionally, the Attitude estimation was performed by using the TRIAD method and Extended Kalman Filter (EKF). Finally, simulation results about power consumption and attitude response of CubeSat are presented. The obtained results indicate that the control scheme design workflow stabilizes the attitude of CubeSat in Detumbling and Nadir Earth pointing; against a maximum disturbance torque which is modelled as a random Gaussian vector.