Research On Attitude Determination And Control System Of Three-Axis Stabilized Satellite

With the rapid development of the space industry, high precision three-axis stabilizedsatellite attracts much attention. To ensure the satellite’s high precision, high reliability andstability of the long-term operation, which means it is necessary to ensure that the satellite hasenough control accuracy and stability. thesis discusses respectively from two aspects, thethree axis stabilized satellite attitude determination and the attitude control, the experimentalresults and analysis confirmed that the method can satisfy the satellite’s accuracy and controlstability when it on operation. At the same time, based on this, use VC++software to developthree axis stabilized satellite control system simulation software, which helps to improvesimulation efficiency. The paper mainly analysis as follows:Definition of the frequently-used reference-coordinate in satellite control system.Separately studied Euler Angle and quaternion these two mathematical description method,and based on them to establish satellites movement model including attitude dynamics,posture, kinematics and environmental interference model, summarizes the fundamentaltheorem and definition of the control theory.Separately describing several classic attitude-determine methods: reference vectormethod, inertial measurement method and the state estimation method, and focus on ExtendedKalman Filtering (EKF) method study, which widely used in state estimation method.According to established EKF attitude estimator, respectively does further research on attitudedetermination system, in order to deduce the filer error equation and to establish measurementequation, the research includes two type of combinations, they are "gyroscope+infrared earthsensor+digital sun sensors" and "the gyroscope+star sensors". The simulation results showsthat the former combination will reduce the measurement accuracy of attitude determinationwhen in the sun shadow region, but can still meet the system requirements. The latter one hashigher accuracy of measurement. The simulation results shows that the former combinationwill reduce the measurement accuracy of attitude determination when in the sun shadowregion, but can still meet the system requirements. The latter one has higher accuracy ofmeasurement.Establish the flywheel mathematical model of flywheel control system; it alsosummarizes satellite momentum’s control principle. According to the whole star zeromomentum of the three axis stable satellite control system, respectively designed traditionalPID controller and sliding mode variable structure controller, and do the simulation experiment for these two controllers. The result proves that traditional PID controller can leadclosed-loop control system to steady state, at the same time, the advantages of simplestructure make engineering easy to realize. In the design of the sliding mode variable structurecontrol law, and the results show that the control law can in satellite attitude tracking processto the inertia of perturbation, external disturbance moment has strong robustness.In the earlier research, and on the basis of VC++software development three-axisstabilized satellite control system simulation software, the three axis stabilized the satellitesimulation and study efficiency has greatly increased with the function of software modularand visual, and the result of operation is good.