Attitude Control Of Satellite Using Control Moment Gyroscope

With the widely used of high-precision optical remote sensing and observation satellites in the areas of scientific research, commerce and military, the structure of the satellite is becoming more complex. Traditional angular momentum exchange actuators(such as flywheel) and jet thruste which can not produce continuous torque output precisely are difficult to meet these requirements, problems caused by vibration and rotation of flexible appendages must be attached importance. Single gimbal control moment gyroscope has became an ideal actuator of agile satellite due to its simple and reliable physical structure, great torque amplification ability, but its inherent singularity caused some impact on its application.Therefore, this thesis investigated attitude control of satellite using control moment gyroscope in depth, the main contents are as follows:Firstly,the basic principle of a single control moment gyroscope were introduced in detail, common configuration of control moment gyroscope are beiefly introduced,and determine the pyramid configuration control moment gyro as the basic principle of control law design in the next chapter. The pyramid configuration control moment gyroscopes because of its good configuration characteristics, are the best configuration of Engineering application. In this paper, the principle and the classification of the singularity of the control moment gyro are described, which is a reference to the design of the control law. Then, coordinate systems are defined, characteristic and conversion relation of quaternion description are summed up. Both kinematic and dynamic models of rigid satellite using control moment gyroscope are established.Secondly, Based on the optimal theory, we obtained a novel steering law with general form, variety of practical steering laws are achieved from the transformation of the general form. the different initial frame angle in the manipulation of the steering law have different effects on the control moment gyro dynamic.we design a kind of seeking optimal initial frame angle method, ensure the control moment gyro operation can be away from the singularity.a new thought of design named feedback-based steering law are proposed and have a obviously effects on avoiding singularity.and then a double hybrid control law are proposed,when the control moment gyro are away from singular system can output accurate torque.otherwise can make the control moment gyro avoid singular, which bring great convenience to hybrid of different steering laws in actual engineering.Finally, for flexible satellite on orbit with not dynamic modeling, model parameter uncertainty and external disturbance torque, a sliding mode variable structure control algorithm with nonlinear disturbance observer and backstepping control algorithm with nonlinear disturbance observer are designed,which is more convenient for engineering application of satellite on orbit flight Both of these two control algorithms have many advantages such as simple structure, explicit physical meaning, parameter can be adjusted conveniently. The reliability and validity for the proposed algorithms are verified by multiple sets of simulation using the same uniform background in Maltlab/Simulink environment.