Open-loop control method for rotation speed change of reaction wheels and unloading method

Abstract

The invention provides an open-loop control method for the rotation speed change of reaction wheels (hereinafter referred to as flywheels) and an unloading method. The open-loop control method for the rotation speed change of the reaction wheels and the unloading method comprise the following specific steps that 1, controlling is conducted through the four flywheels, and the instruction of the magnitude of the reaction wheel control torque of the fourth flywheel is adjusted to be consistent with the magnitude of the theoretical nominal rotation speed friction torque; 2, a control instruction output by a controller is limited within the maximum output torque, the control torque of each flywheel is distributed according to a flywheel distribution matrix, after the control torque of each flywheel is distributed, the flywheel with the maximum output torque is limited within the maximum torque, and the control torque of the other two flywheels is decreased and increased proportionally; 3, the momentum of a synthetic angle of the four flywheels is calculated, and when any axial angle momentum reaches the unloading threshold range and the relationship between the magnetic field intensity and an angular momentum included angle during unloading is met, magnetic torquers are started to be uninstalled; and 4, the magnetic torquer with the maximum unloading capacity is selected to work, and the flywheels are unloaded by adopting a switch control mode.

Description

technical field [0001] The invention relates to the technical field of aerospace control, in particular to an open-loop control method for changing the rotational speed of a reaction wheel and unloading it. Background technique [0002] The reaction wheel is a common actuator for satellites. Due to the higher and higher requirements for satellite attitude accuracy and satellite life, the reaction wheel should be controlled to work near the optimum operating speed when performing attitude control to avoid excessive speed. Zero interference affects attitude accuracy while improving lifespan. [0003] Using 4 flywheels for attitude control, the flywheels can be biased near the nominal speed to form zero momentum. For the torque control mode, the speed of the reaction flywheel will decrease under the action of friction torque. When the speed of the four reaction wheels decreases at the same time, It can also ensure stable attitude and zero momentum throughout the star, that is,...

AI Technical Summary

Problems solved by technology

[0003] Using 4 flywheels for attitude control, the flywheels can be biased near the nominal speed to form zero momentum. For the torque control mode, the speed of the reaction flywheel will decrease under the action of friction torque. When the speed of the four reaction wheels decreases at the same time, It can also ensure stable attitude and zero momentum throughout the star, that is, it is impossible to maintain the flywheel speed through attitude closed-loop feedback. Therefore, to keep the flywheel near the nominal speed requires friction compensation for each flywheel, but because the friction torque of each flywheel is different , the compensation torque causes the nominal speed of the flywheel to be different, which affects the attitude control of the flywheel

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