Research On Attitude Control Of The Long-term Space Station In Orbit

As a long-term stay spacecraft in the space, the application value of the space station can not be replaced by any other spacecraft. The space station is with the highest level of technology and complexity among all the spacecrafts. Attitude control is a key technology for the development of the space station.Choosing attitude control of long-term space station in orbit as the main research content, this dissertation focuses on t he study of space station attitude control and momentum management integration with uncertainty parameters. The main contents are as follows:Firstly, an approximate open-loop form of tracking solution for the torque equilibrium attitude(TEA) is presented. Based on detailed model of the aero torque and gravity gradient torque, the three-axis attitude angles with no momentum accumulation are calculated by open-loop controllers. Disadvantages of this method is also discussed.Secondly, a full-state feedback controller for momentum management and attitude control of the space station is designed. First, the equations of motion is linearized and uncoupled near the small attitude deviation from orbit orientation. Next, a s equential procedure is used for the development of a linear quadratic regulator(LQR), which places the eigenvalues in a specified region of the complex plane. For torque disturbance, the disturbance rejection filter is incorporated in an integrated attitude/momentum controllers. Simulation results are given which show that the controller designed is able to provide the desired performance.Thirdly, the space station equations of motion is linearized and uncoupled near the TEA attitude. By using the pole placement method, the state feedback controller is employed. Simulation results illustrate the desired performance of the controller when the TEA deviations from the local vertical local horizontal orientation.Finaly, according to the variations in the moment of inertias and disturbance of the space station, the final part of the paper discusses the application of variable structure control theory applied to the controllers designed. By using Lyapunov theory, stability of the controllers is proved. Simulation results illustrate the robustness and performance of the controller.