Research On Control Technology Of Reconfigurable Control Moment Gyros

The agile satellite needs to have the ability that it can maneuver fast and high precision attitude control,so that it ensure the accurate and fast tracking and positioning.Compared with the flywheel which is traditional satellite actuator,the control moment gyroscope(Control Moment Gyro:CMG)has the advantages of clean and output larger torque compared to the traditional actuator.It will be the first choice for the satellite which needs to have rapid attitude maneuver and tracking.CMG is the actuator of satellite which has the following problems: first,the current mainstream CMG's output precision is low,a large angle in CMG are usually the first satellite attitude maneuver with large angle maneuver,combined with other actuators for precise control of the way to achieve the desired steady-state control accuracy,but this way increase the complexity and cost of the control system;second,due to the CMG monomer coupling interference in the control process,the control strategy is very complex;third,the current mainstream CMG configuration design,single fault will greatly reduce the system performance.Aiming at the above problems,this paper will be introduced to the reconstruction of configuration design of CMG,it use many micro CMG make up of reconfigurable group,through the reconstruction strategy to change the control mode of CMG monomer in configuration,optimization of CMG group available momentum distribution,so that it can not only provide high torque,but also it can provide fine moment.In this paper,a scheme to replace the large CMG monomer with micro CMG monomers is used to reduce the adverse effects on the system.CMG monomer index requirements of the reduction,but also make the CMG monomer development costs significantly decreased.In this paper,we mainly study the reconfigurable configuration,control mechanism and the distribution of singular surface of CMG:On the basis of the relevant theoretical research,the reconfigurable architecture of CMG group is designed.The CMG group system provides the ability of angular momentum as the constraint condition,analyses the benefits of various configurations of 4~8 group angular momentum CMG monomer composition,and through the analysis of the influence on the configuration of angular CMG's failure.According to the comparative analysis,a reconfigurable configuration scheme consisting of 8 CMG monomers is proposed.When the satellite needs to have rapid maneuver,CMG group change into high torque output mode;when the satellite needs small torque fine control,CMG group change into small output torque,high torque and low torque can take into account the fine control of rapid maneuver when two cases.In this paper,the singularity of reconfigurable CMG configuration is analyzed.Based on the investigation of the mechanism and classification of the traditional configuration singularity,this paper makes a research on the distribution of various kinds of singular surfaces of the designed CMG reconfigurable configuration.Compared with the traditional configuration,the singular surface distribution is well distributed and can not be avoided by the zero motion.The study on the CMG reconfigurable group involved in satellite attitude control is studied,using non singular robust control law reconfiguration after manipulation of the structure,and design a new filtering backstepping attitude controller based on satellite.Based on Matlab/Simulink,the satellite's large angle and small angle maneuver simulation are carried out by using the classical configuration and reconfigurable configuration,and the correctness and feasibility of the reconfigurable CMG configuration are verified by comparison.