Ground Evaluation of the Attitude Control System of 3U-CubeSat IHI-SAT

Abstract

IHI Corporation and the Space Robotics Laboratory (SRL) of Tohoku University have jointly developed a 3U-CubeSat named “IHI-SAT”. The purpose of IHI-SAT is to demonstrate an AIS (Automatic Identification System) receiving system that collects ship identification information at sea and transfers it to ground stations to keep track of the congestion situation at sea. In order to keep the development of this satellite at a low cost, it is necessary to downsize the attitude control system and evaluate the attitude with a limited number of sensors. This satellite performs attitude estimation by applying Kalman filtering on the data obtained from a magnetic sensor and a gyroscope. The SRL has a simulator technology for ground evaluation called SSES that simulates the space environment and the satellite dynamics. This simulator is constructed based on the operational data of the satellites developed by the SRL in the past, so its reliability is guaranteed. In this research, in order to evaluate the hardware equipped with the onboard software of the attitude control system, a HILS (Hardware-in-the-Loop Simulation) environment was constructed by connecting SSES and the attitude control system. By comparison with the result of SILS (Software-in-the-Loop Simulation), it was confirmed that a reliable ground evaluation environment could be established and the attitude control system performance was evaluated for IHI-SAT. This system can be used for other CubeSats to establish a versatile ground evaluation environment.