Design and Evaluation of Thruster Control Approach for Micro-satellite ALE-2

This paper provides the thruster control approach for micro-satellites to realize autonomous orbit and attitude control. The Space Robotics Laboratory (SRL) of Tohoku University and ALE Co. Ltd. are currently developing a micro-satellite called "ALE-2" to generate artificial meteors. This satellite is required to keep the sun-synchronous orbit at the altitude of 375-400 km due to operational safety and mission constraints. ALE-2 is equipped with the High Density Cold Gas Jet System (HDCGJ) developed by Patchedconics, LLC for orbit and attitude control. Although a variety of thruster control methods have been proposed, this research focuses on a design of a reliable, uncomplicated and robust algorithm using the low-thrust, 4 nozzle propulsion system. A precomputed thruster selection table is utilized to reduce the processing power and to optimize the thrust force and torque distribution. The evaluation result from the full-software closed-loop simulation demonstrated that the proposed approach was valid for the orbit control of ALE-2 while high attitude control stability could be maintained in the long term.