Research On Fast Attitude Maneuver Of Satellites Based On Flywheels And Thrusts

The article chooses the large and very high-resolution reconnaissance satellites forstudy. This paper studies the problem of rapid attitude maneuver based on joint controlbetween reaction wheel and thruster. Due to the limited capacity of reaction flywheel andcontrol accuracy of thrust is low, we study the joint control strategy and the switchingalgorithm to achieve rapid attitude maneuver and stable. The content of the study includethe following aspects:First it derived the dynamic model of reconnaissance satellites with Lagrangeequation. Then derived the kinematics equations of reconnaissance satellites and expressthem in the form of matrix. It laid the foundation for design and simulation of the controlsystem.According to the characteristics of Thruster and Reaction Wheel, we have designeda control allocation scheme based on the two implementing agencies and derived theswitch allocation algorithm under the circumstances that thruster control accuracy is nothigh and the reaction flywheel output torque is limited. The effectiveness of theswitching algorithm is verified by mathematical simulation. The thrust output who withstrong nonlinear characteristics is the output of the switch constant value, so we designedthe PWPF. It can automatically modulated pulse width and frequency of the switch toturn the amount of modulation into a continuous quantity.In this paper, we use the stability theory of Lyapunov to design the PD controllerand the sliding mode variable structure controller. From the time of maneuver, controlaccuracy and stability, we compared the two controllers, and then get the controllerwhich is suitable for the thruster and reaction flywheel. The coupling effects between thesolar panels’ vibration and body motion will reduce the control precision and stability ofthe satellite. To lower this effect, a positive position feedback controller is designed. Itcan increase the system damper to suppress the vibration of the solar panels. We setsingle degree of freedom and multi degree of freedom system as example and use themathematical simulation to verify the effect of the positive position feedback controller.Finally, we will form a composite controller of the attitude controller and solarpanels vibration suppression controller for a reconnaissance satellite. Then together withthe switching algorithm, the mathematical model of the implementing agencies and thereconnaissance satellite dynamics, kinematics model constitutes a closed loop system. Itmakes a Closed-loop system simulation with MATLAB software last.