Attitude Determination System for Nanosatellites
CubeSat, Attitude Determination, Nanosatellite, Kalman filter.
The technological advances of the last decades, together with the standardization of the CubeSat, have made viable the use of nanossatellites for commercial and institutional purposes. Taking advantage of the trend, the National Institute of Space Research has been developing the CONASAT project, which consists of a constellation of nanossatellites for the collection of environmental data. In this context, the present work aims to evaluate methods of attitude estimation for nano-satellites, in order to meet the requirements of the project, which requires attitude stabilization in the three axes. It adopts a kinematic model of the system with quaternion attitude representation, and a dynamic model considering the object as a rigid body. The attitude sensor system consists of a magnetometer and a sun sensor, simulated from the ideal model with added white Gaussian noise. Four attitude estimation algorithms are initially evaluated: the TRIAD, the Davenport's q-Method, the QUEST, and the extended Kalman filter (EKF). Preliminary simulations are presented, with a comparison between the methods searched. Finally, some conclusions and final considerations are presented.