Design of a control moment gyroscope with outer rotor BLDC motor

İnce, Berk
The aim of this thesis is to design a control moment gyroscope (CMG) with outer rotor BLDC motor for medium size satellites. CMG is a device that provides high output torque to the satellite in order to maneuvering satellites rapidly. CMG is the most efficient actuator in terms of output torque capacity when it is compared with other type actuators such as the reaction wheel. The first step of the designing CMG is to determine CMG design specifications. The mass and volume specifications of the designed CMG are selected to be the same as the previous satellite actuator (reaction wheel) that was used in the previous satellite program Satellite maneuvering calculations on x and y axes are covered for four different maneuvering cases to determine the required CMG output torque capacity. Operating temperature, operating voltage, and maximum gimbal angle excursion are other specifications to be considered in the design process of the CMG in this thesis. In addition, the effect of the four different maximum gimbal angle excursions on the CMG design is investigated. The designed CMG consists of the wheel, BLDC motor, and gimbal structure. The wheel that provides the required inertia is designed to generate CMG output torque. During the wheel design, mass and volume reduction calculations are done and yield stress and safety factor constraints of the wheel are considered. To drive the wheel of CMG, the outer rotor BLDC motors are designed. The designed motor satisfies electrical loading and magnetic loading constraints and the mass of the motor is selected as low as possible. Step motor for gimbal angle control, step motor driver and gear system are selected for gimbal structure to overcome the required torque of the gimbal system. The thermal simulation model of the designed CMG is created to analyze thermal performance of the CMG. In the end, the design results of CMG are shown. In this thesis, it is shown that although mass and volume are the same for these two actuators, the output torque capacity of the designed CMG is higher than the previous reaction wheel.
Citation Formats
B. İnce, “Design of a control moment gyroscope with outer rotor BLDC motor,” Thesis (M.S.) -- Graduate School of Natural and Applied Sciences. Electrical and Electronics Engineering., Middle East Technical University, 2019.