دانلود رایگان مقاله متوقف سازی ارتعاشات فعال در فضاپیمای انعطاف پذیر با اندازه گیری نوری

ABSTRACT

With the development of the space station technology in China, the active vibration suppression of the lager flexible antennas and solar panels that mounted on the space station is demanded. The active vibration suppression is hard to achieve because these appendages are not allowed to mount actuators on it. Further, the practical goal is usually unachievable by the controller based on the unreliability or impracticality observed vibration parameters. In this paper, the active vibration suppression during the spacecraft attitude maneuver by the optical camera monitoring the dynamic behaviors of the flexible appendages is introduced under the restriction of the freedom of the actuators. The modal parameters of the flexible appendage used in the controller are obtained by the optical monitoring approach. A referenced angular velocity is set as the virtual input by the back-stepping control and Lyapunov method, and the control law is designed to track this virtual input. The constraint of the coefficient in the controller is investigated to guarantee the asymptotic convergence of the system considering angular velocity tracking error. The control manage coefficient is defined to describe the distribution coefficient of the vibration suppression in the design of control law. The relationship between the attitude maneuver accuracy and active vibration suppression is introduced. The appropriate control manage coefficient is obtained numerically. To guarantee the reliability or practicality of the designate flexible spacecraft control system, the optical measurements are used to measure the dynamic behaviors of the large flexible structures. The absence of displacement velocity sensors is compensated by the presence of appropriate dynamics in the controller. The results of simulation validate the feasibility of the proposed control strategy

5. Conclusion

In this paper, the active vibration suppression of the flexible appendages, which are not allowed to be allocated with actuators, is introduced. The optical measurements, instead of an observer, are used to measure the dynamic behaviors of the large flexible structures in order to guarantee the reliability and practicality of the designate control system in the actual on-orbit service. The active vibration controller during the spacecraft attitude maneuver is proposed under the restriction of the freedom of the actuators. The simulation results show the feasibility of the newly proposed active vibration suppression method. The control manage coefficient is defined to describe the distribution coefficient of the vibration suppression in the controller. The relationship between the control manage coefficient, the attitude control accuracy and the vibration suppression is discussed. The controller with appropriate control manage coefficient is not only able to effectively damp the vibration, but also to improve the accuracy of the attitude maneuver and the performance of the control torque of the flexible spacecraft. The numerical method to obtain the appropriate control manage coefficient is introduced. The control manage coefficient defined in this paper can also be determined by the requirements of actual control missions. The control manage coef- ficient k1c is of first priority when the mission is concentrated on the attitude control accuracy. Numerical simulations validate the proposed active vibration suppression algorithm. Furthermore, the control manage presented in this paper is considered as an instruction for the actual control mission. The problem discussed in this paper derives from the requirements of actual control missions and extends the existing control methods. The method and results put forward in this paper is supposed to be utilized in the actual control mission of the space station.