Designing, Testing and Evaluation of Single Gimbal Control Moment Gyro for Microsatellite

In this paper, a designing procedure of Single Gimbal Control Moment Gyro (SGCMG) for performing an agile slew maneuver in a microsatellite is described, then a prototype is fabricated and finally the test results are presented. The design of actuator mechanism is based on simplicity, direction of produced torque, minimum volume and weight. A DC electrical and a stepper motor with accuracy of 0.024 degree are used for controlling the angular velocity of flywheel and the gimbal slew rate, respectively. The motors controller and driver units are designed and implemented, so that the maximum accuracy, minimum errors and best response time could be accessible. The flywheel design is based on the required angular momentum which should be stored. The gimbal consists of two in-line beams which are attached to bearing in one side and momentum wheel system in the other side. A specific approach was considered to avoid any deformation in beams in consequence of mounting the momentum wheel system.