Design of Reaction Wheels Based on COTS Device for Nano-Satellite

In this paper, a modular micro-reaction wheel based on Commercial off the Shelf Components (COTS) is designed to meet the mission requirements of nano-satellites. The system is guided by open box-shaped structure and the flywheel is drived by brushless DC motor(BLDCM), which can avoid the resonance problem according to vibration mode analysis. The controller uses the integral separation control algorithm and based on Ultra-low-power processor to capture the Hall Signal speed and drive the MOSFET bridge to change phase. The proposed flywheel has successfully passed the ground test and environmental test, the measured flywheel parameters are as follows: mass 63 g, size 36 mm×36 mm×28 mm, maximum speed 9 000 r/min, maximum angular momentum≥5.5 mNms, torque≥0.2 mNm, power consumption≤500 mW. On June 25, 2016, the flywheel as part of the world's first 12U CubeSat “Star of AoXiang”, which is the first satellite of Northwestern Polytechnic University, launched into the orbit along with “CZ-7” and served as the actuator for 99 days with excellent working conditions, until it fell into the atmosphere. Both the ground test experiment and the flight verification results show that the proposed COTS flywheel can meet the mission requirements for nano-satellite and CubeSat.