On-board algorithm for SamSat-218D nanosatellite orientation and stabilization system

Abstract

Algorithms for determining the attitude and angular rate damping of the SamSat-218D nanosatellite developed at Samara State Aerospace University are described in the paper. The date of the prospective launching of the satellite into the Earth orbit from Vostochniy spaceport is April, 2016. A triaxial magnetometer and luminance sensors are used as sources of information in the orientation system. Three magnetic coils serve as actuators providing the angular rate damping onboard the nanosatellite. A known method of vector coordination with the original criterion of preliminary measurement rejection is used as the orientation determination algorithm since the vector coordination method is very sensitive to measurement errors. The traditional B-dot algorithm is used as the damping algorithm. The influence of the initial angular rates on the magnetic moment coefficient in the B-dot control algorithm is studied. Since the continuous mode of operation of magnetic coils on board the nanosatellite is unpractical due to the necessity of measuring variations in the Earth magnetic field intensity vector the damping process is analyzed in the discrete mode of operation at different values of angular rates of nanosatelite separation. The comparison of the algorithm processing speed in the continuous and discrete operating modes at various initial angular rates of separation is given.