Studies On The Attitude Determination And Control System Of High Precision Three-Axis Stabilized Satellite

The dissertation, taking a specific meteorological satellite as an example, studies systematically and thoroughly the design and realization of an attitude determination and control system for the three-axis stabilizing satellite. Some further research is done in the field of robust Kalman filtering, attitude determination algorithms, correction algorithms of the earth oblateness and flywheel control, et al.The main work done in the dissertation is as follows:1 .The attitude representation of Euler Angle and Quaternion are analyzed and generalized. Then the attitude kinematic and dynamic models about rigid/flexible satellite are developed employing Quaternion and Euler-Angle representations.2.The first part is to analyze the two error sources of the earth horizon sensor: one is earth oblateness and the other is non-uniformly distributed atmospheric infrared radiation. The measurement process of the attitude angle based on single trailing earth horizon sensor is investigated, and an analytical formula of attitude compensating error is obtained.The second part is concerned with the influence of the semi-scan angle on the measuring process of the horizon sensor. The results shows that the oblateness influence attitude measuring through the semi-scan angle, and the essence of earth horizon measuring error is that the geodetic normal on the reference spheroid is not aligned with the geocentric normal.The final part is the design of a new iteration algorithms to compensate oblate error of the horizon sensor, which base on the earth elliptical model, the earth horizon plane and scanning cone model, and the simulation show its validity.In addition, the compensating algorithm of the gyro random drift is studied. An iterative method of minimum squares with a fading-down divisor is given to identify the parameters of gyro random drift model on line. An algorithm consisting of broad-sense minimum variance control and iterative method of minimum squares with a fading-down divisor is put forward to correct the gyro random drift, and the simulation show that this method was practicable and gyro random drift is reduced.3.Attitude determination subsystem for a specific satellite is designed byextended kalman filter equipped with three-axis gyro, earth horizon sensor and three-axis magnetometers, which include attitude sensor allocation, measurement modeling, attitude estimating algorithms and so on.The method of the robust filtering is analyzed, and the algorithm of the robust Kalman filtering of the discrete uncertainty system is studied. The result shows that the algorithms have the characteristic of strong robustness, unbiased estimation.Then a velocity estimation method is put forward by using robust kalman filtering, and it is used to do rate damping when the satellite initially enter the orbit. The new method to perform rate damping on gyro-less satellite is put forwarded.4.The typical flywheel installation considering reliability and optimal installation are analyzed, and their stable state performances are studied. The performances among them on the response and power consumption are compared based on PID control laws.Secondly, the influence of the flywheels approaching zero rating is compared between the torque mode and momentum mode, and the results show that the stabilizing precision of the flywheel system in a momentum mode will have 4:1 attitude error reduction corresponding to torque mode.The final part is concerned with dahl model of the flywheel actuator. Its mathematical model characteristic and dither compensating method are discussed. The dahl model is verified by adding offset pulse dither signal compensating for wheel friction, and it actually improves the performance to a great extent.5.First, The characteristic of the WHECON-biased momentum is investigated, and the magnetic-torque control law is analyzed. Second, The performance of the single-freedom momentum wheel under the minimum phase control is studied. The comparison between those two-momentum wheel schemes is d...