An Attitude Control Method for Flexible Spacecraft Based on Finite Time Friction Estimation

Abstract

The invention provides a flexible spacecraft attitude control method based on limited time friction estimation. The control method comprises the following steps: a, introducing spacecraft flywheel friction interference into an spacecraft dynamic system, and establishing a flexible spacecraft dynamic system sigma1 with the flywheel friction interference; b, converting the flexible spacecraft dynamic system sigma1 with the flywheel friction interference into a state space form; c, constructing a flywheel friction interference estimator; d, constructing a flexible accessory vibration interference observer; and e, compounding the flywheel friction interference estimator in the step c and the flexible accessory vibration interference observer in the step d with a nominal controller so as to obtain a composite controller which compensates flywheel friction through an estimated value of flywheel friction torque and compensates vibration interference of a flexible accessory through an estimated value of the vibration interference of the flexible accessory.

Description

technical field [0001] The invention relates to the field of aerospace technology, in particular to a method for controlling the attitude of a flexible spacecraft based on finite-time friction estimation. Background technique [0002] The spacecraft attitude control system is an important part of many systems of the spacecraft. The accuracy, stability and reliability of the spacecraft attitude control are the key technologies in the process of spacecraft development. In recent years, the tasks that spacecraft need to undertake have become more and more complex, which makes the demand for power continue to increase. Therefore, it is necessary to have a larger area of ​​solar panels to meet the needs of the mission. The requirements are getting higher and higher, and antennas with larger structures need to be designed as much as possible to complete data exchange and communication. These requirements have made the accessories of spacecraft more and more large. In terms of lau...

AI Technical Summary

Problems solved by technology

However, the flywheel has very distinctive characteristics. Due to the limitation of processing conditions, when the flywheel crosses zero at low speed, friction torque will be generated, which will affect the attitude control system of the spacecraft. Even in some cases, due to the repeated zero crossing of the flywheel speed, the flywheel will It generates tremors by itself, and then drives the spacecraft body with flexible accessories to tremble, and then makes the flexible accessories start to tremble, making it more difficult for the spacecraft system to be stable and difficult to achieve high-precision attitude control

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