Research on Attitude Determination and Magnetic Control for Small Satellites
|School||National University of Defense Science and Technology|
|Course||Aeronautical and Astronautical Science and Technology|
|Keywords||Micro-satellite Extended Kalman filter Linearization Rate damping Cold jet device Magnetorquer Minus-dot-B PID Three-axis stabilized control Axis magnetometer|
Today, satellite technology has become more sophisticated and the development of small satellite with its low-cost, short cycle characteristics by the attention of many research institutions and universities. However, due to the tiny satellite is limited by the physical size, weight, power consumption, development costs and other factors, such tiny satellites using traditional satellite design. In order to better meet the needs of small satellite development process, to improve the overall performance of the micro-satellite, the thesis is based on the engineering application determine magnetron tiny satellite attitude control technology research has important engineering reference value. Tiny satellite attitude determination, using a three-axis magnetometer to simulate the sun-sensitive, a micromechanical gyroscope as a gesture sensitive devices, the establishment of a satellite attitude kinematics, dynamics mathematical model and attitude sensors measurement model. Taking into account the non-linear factors and the onboard computer in the tiny satellite attitude determination computing speed, storage capacity and other constraints, the paper using conventional processing nonlinear problem extended Kalman filter method for data processing and attitude estimation, the equation of state , measurement methods, linearization, discretization, derivation of the linearized model error, the extended Kalman filter model, given by digital simulation magnetometer, gyroscope, sun-sensitive gyro two attitude sensors combination under the simulation results. Control of the tiny satellite rate damping stage, the paper uses the magnetic moment, the cold jet device as the executing agency, Minus-dot-B controller and PID controller design and digital simulation given magnetic Moment \Simulation results show that in Minus-dot-B under the control of the satellite rate damping time is shorter, but the damping accuracy is not high, the angular velocity is relatively large fluctuations; under the PID control, the satellite rate damping time is longer, but less energy consumption, the damping high precision angular rate fluctuation is very small. Control of the tiny satellite stage of three-axis stabilized, the papers still use the magnetic moment, the cold jet device as the executing agency. For satellite equipped with a bias momentum wheel analysis of the freedom of movement of the characteristics of satellite attitude, the research and design of pitch channel and scroll - the yaw channel's attitude control algorithm, gives the magnetic moment axis stabilized control of the simulation results. Bias momentum wheel satellite, micro-jet device magnetic moment \Simulation results show that the three-axis stabilized control method used in this paper to meet the accuracy requirements of small satellite attitude control. Finally, the important attitude determination and control system the attitude sensors - triaxial magnetometer measurement error correction method, a three-axis magnetometer measurement error sources, the establishment of a measurement error correction Mathematics model, experimental verification of the error correction method of the present measurement and through experiments. The experimental results show that, This paper presents three-axis magnetometer measurement error correction method can effectively correct the measurement axis magnetometer output data, to improve its measurement accuracy for high-precision micro-satellite attitude determination and control provided good posture sensor conditions.