High-precision moment output control method for control moment gyro group

Abstract

The invention relates to a high-precision moment output control method for a control moment gyro group. The method comprises the following steps: (1) firstly, establishing a kinetic model of the control moment gyro group; (2) constructing a singularity avoidant manipulation rule algorithm and determining distance threshold values d1 and d2 of the control moment gyro group approaching to a singular area; (3) judging singularity of the kinetic model of the control moment gyro group and calculating a singularity metric value D of the control moment gyro group; if D is larger than d1, a paseudo-inverse manipulation rule algorithm is directly used as the manipulation rule of the control moment gyro group, if D is larger than d2 and smaller than d1, decreasing the accommodation amplitude of a parameter lambda, and if D is larger than 0 and smaller than d2, increasing the accommodation amplitude of the parameter lambda; (4) calculating framework angular speed values of each control moment gyro of the control moment gyro group; (5) integrating framework angular speed and calculating to obtain a framework angle position input to the step (1) for circular calculations and driving the control moment gyro group to output a moment to a satellite according to the framework angular speed values.

Description

technical field [0001] The invention relates to a high-precision torque output control method for an agile satellite attitude control actuator to control a torque gyroscope group. The design of the method compensates for the singularity defect of a single frame control torque gyroscope, and improves the torque output accuracy of the control torque gyroscope group. Background technique [0002] Agile satellites have the dual capabilities of large-width and high-resolution imaging with the help of agile maneuvering of attitude, which has become one of the important development directions of small satellites. At present, the actuators of the satellite attitude control system mainly include three categories: (1) thrusters; (2) flywheel actuators: including reaction wheels, (bias) momentum wheels, frame momentum wheels and control moment gyroscopes; (3) Environmental Torque Actuator. The control moment gyroscope is the best choice for attitude control of large satellites such as...

AI Technical Summary

Problems solved by technology

The control torque gyroscope group composed of multiple control moment gyroscopes has two problems: (1) the configuration of the control moment gyroscope group, different configurations have different torque output capabilities; (2) the singularity problem of the control moment gyroscope group , when the group of control moment gyroscopes is manipulated to output torque, the column vectors in the moment equation matrix of the control moment gyroscope group will appear parallel to each other, and this state will cause the control moment gyroscope group to not be in the direction orthogonal to each column vector output torque, or when the column vectors in the torque equation matrix are located in the same plane, the control moment gyroscope group cannot output torque in the direction perpendicular to this plane. In the above cases, the control moment gyroscope group loses three-dimensional control ability and falls into a singularity state

Therefore, the current control law design methods for these three types of control moment gyroscopes cannot meet the high-precision requirements for attitude control of highly agile satellites.

[0005] Chinese patent: 200810222230.7, titled "Spacecraft Attitude Control System with Singular Steering Law Avoidance", involves controlling the torque output control of the moment gyroscope group, mainly using zero motion algorithm, look-up table method and pseudo-inverse algorithm of steering law The switch to solve the singularity problem of the control moment gyroscope group in the spacecraft attitude control system. Although this design method avoids the singularity problem of the control moment gyroscope group to a certain extent, the zero-motion algorithm can only avoid part of the singularity point, and the zero-motion algorithm Singular areas that cannot be avoided need to be solved by calculation and table lookup. This design method leads to frequent switching of the steering law algorithm, and the calculated angular velocity of the frame has a large jump, which introduces errors to the high-precision output of the torque, and the amount of calculation is large.

Images