A Satellite Attitude Control Method Based on Three-DOF Momentum Exchange of Spherical Motor

Abstract

The invention relates to a satellite attitude control method based on three-freedom-degree momentum exchange of a spherical motor. According to the satellite attitude control method, a spherical momentum exchange device is the spherical motor, and the spherical motor is connected with a satellite platform through a stator shell. The satellite attitude control method comprises the following steps that 1, a control Euler axis rotating angle is determined; 2, a hierarchical control Euler axis rotating angle is determined; 3, the incremental control torque of each level is determined; 4, a spherical rotor track control command is determined; 5, trajectory tracking control over a spherical rotor is conducted; 6, the increment grades n are adjusted. By the adoption of the satellite attitude control method, the weight of an aircraft can be reduced, satellite-borne space is reduced, and control is easy.

Description

technical field [0001] The invention belongs to the field of satellite attitude control and relates to a satellite attitude control method. Background technique [0002] Satellite attitude control plays a key role in whether spaceborne instruments can accurately orient or track targets, and then complete specific tasks (such as reconnaissance, communication, relay, etc.). The traditional satellite attitude control mainly relies on the jet reaction system and the inertial actuator. The former not only consumes fuel, but also pollutes the sensitive instruments on board. The inertial actuator mainly includes flywheel (RW) and control moment gyro (CMG). The advantages are that only solar power is required, long life, high precision, and little pollution. [0003] Compared with RW, CMG has a torque amplification effect, but in order to realize the three-degree-of-freedom momentum exchange with the satellite platform, the system structure is more complicated, and the rotor needs ...

AI Technical Summary

Problems solved by technology

Configuring an additional outer frame or adjusting the rotor speed essentially provides a degree of freedom for the system, so these two solutions only have two degrees of freedom, and it is impossible to rely on a single VSCMG or DGCMG to complete the three-dimensional momentum exchange with the satellite platform

In addition, the limitation of the outer frame also increases the singularity risk of the system

The current solution generally requires several CMG units to cooperate to form a CMG gyro group (Cluster), such as a pyramid configuration, and it is necessary to formulate a manipulation rate for the singular point problem. The huge servo system greatly increases the weight, volume, and weight of the attitude control system. Cost and energy consumption, the current application is mostly seen in large space stations

Recently, some scholars have proposed a dual-frame variable speed torque control gyro (DG-VSCMG) that combines the above two. Although this scheme has three degrees of freedom in theory, its torque amplification effect is not good due to the limitation of the double frame. Ideal, and the mechanical structure and control strategy are extremely complex, and there are few related studies at present

In order to prevent possible under-actuation, the inertial actuators must also be equipped with redundant units. At present, many space stations in orbit use a fourth flywheel on the basis of three orthogonal flywheels to obliquely intersect with three orthogonal flywheels, which further Increased complexity of system structure and control

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