Inertia tensor estimation for a rigid nadir pointing satellite based on star tracker

Abstract

Accurate inertia properties information is important to reach an optimized estimation of attitude and precise control of a rigid spacecraft. Unfortunately, the satellite is succumbing several influences that can affect the inertia properties, such as fuel consumption and sloshing. Thus, this work inspects the use of star tracker to estimate the attitude, angular velocity and moment of inertia for a rigid nadir pointing satellite by employing extended Kalman filter, without any prior information about the nominal inertia matrix. The proposed estimator is applied in nadir pointing mode and without any constant control torque to avoid the attitude tumbling during the estimation phase, which in turn leads to a catastrophic failure of the satellite mission. The simulation results are compared to three other approaches and validated by Monte Carlo method that elucidates the good performance of the suggested approach and demonstrates its efficiency in satellite inertia tensor and attitude estimation even in worst situations.