Satellite three-axis attitude control method combined with magnetic torque device when the flywheel is underactuated

Abstract

The satellite three-axis attitude control method combined with the magnetic torque device when the flywheel is underactuated, the steps are: (1) Determine the magnetic control matrix Γ(b) according to the geomagnetic field intensity vector B measured by the magnetometer, and according to the actual flywheel availability , determine the flywheel control matrix Kw; (2) calculate the magnetic current command Izk=Kic*Mzk for three-axis attitude control; (3) calculate the magnetic current command Ixz=Kic*Mxz for three-axis magnetic unloading; (4) calculate the magnetic torque device Command Ick=Izk+Ixz; while the magnetic torquer performs attitude control according to the magnetic torquer command, the available reaction flywheel continues to perform attitude control based on the command torque Tc. The method of the present invention realizes the high-precision control of the satellite's three-axis attitude in combination with the three-axis magnetic torque device when there are only two or even one flywheel available in the system, and is suitable for long-term ground-oriented control or long-term sun-oriented control, and also It is suitable for the maneuvering control of satellites at any attitude and large angle.

Description

technical field [0001] The invention belongs to the field of spacecraft attitude control, and relates to a satellite three-axis attitude control method when a flywheel is under-driven. Background technique [0002] Modern small satellites generally do not carry a jet system, and the reaction flywheel has become the main actuator for high-performance attitude stability control and high-angle attitude maneuver control of small satellites. When the average value of the disturbance torque received by the satellite is not zero, the angular momentum of the flywheel will accumulate over time, which will eventually lead to the saturation of the flywheel rotational speed. Therefore, modern small satellites also need to be equipped with magnetic torquers to realize flywheel unloading. That is, the reaction flywheel is usually used for attitude control, and the magnetic torque device is used to cooperate with the flywheel to complete the unloading of the flywheel. [0003] In the pas...

AI Technical Summary

Problems solved by technology

When any one or any two flywheels fail, the flywheel system will not be able to provide three-axis attitude control torque, so the attitude control system degenerates into a typical flywheel underactuated control system (the number of control inputs is less than the number of system degrees of freedom) , no longer have three-axis attitude control capability

Images