Researches On Control Related Characteristics Of Single Gimbal Control Moment Gyros

The development of space technology of china requires the spacecrafts of more functions and higher requirements on pointing accuracy, attitude stabilization and service life of the spacecraft. Based on practical demand of controlling the attitude of large-scale spacecraft, the thesis analyzes the configuration characteristic, steering law design of the Single Gimbal Control Moment Gyros(SGCMG) and provides references in theory for the Application of SGCMG in spacecraft attitude control.Firstly, according to pyramid configuration and five pyramid configuration,which are widely used, the thesis analyzes the efficiency of SGCMG configuration on actual performance of the attitude control mechanism, then draws configuration singular surface and singular envelope by numerical calculation. After analyzing Gauss curvature of the singular surface, the thesis shows graphical representations of all elliptic singular states of the two configurations, and deduces configurations index on normal working condition. At last, it's demonstrated that if it can meet the demand of spacecraft attitude control on condition that one of the SGCMG is failure.Second, According to the principle of least energy and accurately track the torque output instructions, Penrose-Moore steering law is designed. For the Penrose-Moore pseudo-inverse steering law was easy to make SGCMGs into the singular state, pseudo-inverse steering law with null-motion is designed based on singularity measure. At the same time, considering the gimbal angular velocity limit and control errors, singularity robust steering law is designed based on linear quadratic optimal theory to solve the problem that pseudo-inverse steering law failures in singularity. And then, based on the method of adding periodic perturbation, perturbed singularity robust steering law is designed which do not rely on input torque commands while escaping the singular state.Last but not least, on the basis of configuration analysis and design of control laws, a simplified gimbal servo system model is established and the controller is designed, then the SGCMG systems were simulated to verify the configuration and control law analysis results are correct. And then, combined with spacecraft attitude dynamics model, spacecraft attitude control simulation model building on SGCMGs is established in the form of the configuration and the steering law ascertained, and the response of SGCMGs in the process of spacecraft attitude control is analyzed.