Fault-tolerant attitude control systems using multi-objective optimization for a spacecraft equipped with control moment gyros

In recent years, there has been a requirement for accurate and agile attitude control of spacecraft. To meet this demand there has been an increasing use of Control Moment Gyros (CMGs), which can generate much higher torque than reaction wheels that are used as conventional spacecraft actuators. The drive on the motors is needed for rapid maneuverability, negatively affecting their life. Thus, in designing spacecraft the conflicting requirements are rapid maneuverability and reduced the drive on motors for long operation life. Furthermore, the attitude control system needs to be fault-tolerant. The dominant requirement is different for each spacecraft mission, and therefore the relationship between the requirements should be shown. In this study, a design method is proposed for the attitude control system, using multi objective optimization of the skew angle and parameters of the control system. Pareto solutions that can show the relationship between the requirements are obtained by optimizing the parameters. Using numerical analysis, it is shown that an attitude control system appropriate to the dominant situation can be designed and the appropriate skew angle and parameters of the control system, which correspond to the considered requirements, can be confirmed by the proposed method.