PERFORMANCE ANALYSIS OF AN ATTITUDE CONTROL SYSTEM FOR SMALL SATELLITES

Attitude Determination and Control (ADC) algorithms may implement different solutions depending on computational performance and sensor accuracy. Pointing requirements may be very restrictive and the ADC System (ADCS) shall be compliant with these strict requirements, ensuring their satisfaction through the implementation of robust control algorithms and design of a proper actuation system. The objective of this paper is the design of a robust flight software, in which the key features are (i) suitably designed control laws to guarantee the robustness to uncertainties and (ii) detailed model of the external disturbances, focusing on Low Earth Orbit (LEO) missions. In this paper, a first-order and a second order sliding mode controllers are proposed. Extensive simulations are performed to prove the effectiveness of the proposed control system in a LEO mission scenario, including uncertainties of the spacecraft configuration, measurement errors and errors in torque actuation. Moreover, a detailed model of external disturbances is taken into account, since this controller is proposed for LEO missions.