Angular momentum management method for variable-speed control moment gyroscope

Abstract

The invention relates to an angular momentum management method for a variable-speed control moment gyroscope (VSCMG). A technical scheme is described as follow. An angular momentum management algorithm for the VSCMGs is designed to mainly solve the following problems: mixed mode instruction torque output based on singularity measurement, zero-motion rotor wheel speed balance, zero-motion frame configuration singularity avoidance, frame angular velocity dead-zone nonlinear processing and neglected item compensation, and gives corresponding theoretical analysis. The mixed mode of the VSCMGs gives full scope to the large torque output of the control moment gyroscope and large-angle fast attitude maneuver operation can be achieved by using the steering law. The present invention provides a novel VSCMGs angular momentum management algorithm which is improved significantly in torque output accuracy, angular velocity tracking, and frame singularity avoidance compared with a conventional angular momentum management algorithm, and which has a good engineering value.

Description

technical field [0001] The invention relates to an angular momentum management method of a variable speed control moment gyroscope, relates to the field of attitude control of aerospace satellites, and in particular relates to angular momentum management of a variable speed control moment gyroscope (VSCMG), an angular momentum exchange device used for attitude control on a satellite method, a technology that separates the rotor acceleration and the frame motion to achieve a good torque output accuracy. Background technique [0002] With the rapid development of the aerospace industry and the diversification of space missions, various attitude control devices have emerged as the times require, from pico-satellites of a few kilograms to space stations of hundreds of tons. At present, the actuators used for the active control of satellite attitude maneuvering mainly include thrusters, reaction flywheels, and control moment gyroscopes. Control moment gyros include single frame ...

AI Technical Summary

Problems solved by technology

[0007] Finally, the variability of the rotor speed of VSCMGs leads to the same angular momentum saturation unloading problem as the flywheel system. How to design an appropriate unloading strategy to ensure that VSCMGs can work stably for a long time is a problem that VSCMGs must consider

[0008] The so-called CMG / RW hybrid mode in the traditional VSCNGs maneuvering law is based on the command torque, through the weight matrix to distribute the torque, and then solve the frame angular velocity and rotor angular acceleration together, and then make the CMG try to avoid hidden singularity through zero motion, and make the rotor The speed tends to the specified speed, but there are two problems in this control law: although the weight matrix of torque distribution can be flexibly changed by the singularity measure of the CMG mode, the relationship between the selection of the weight matrix and the distribution of torque is subtle, Moreover, the singularity of the RW configuration was not taken into account when the moment distribution was performed. It is possible that when the CMG is close to singularity in a certain direction, most of the moment is distributed to RW through the weight matrix, but at this time the RW configuration is also in the other direction. Close to singularity, in the actual operation process, the angular acceleration of the rotor may be very large, exceeding the execution capacity of the actuator, (although the essence of VSCMGs that is not singular as a whole is that when a certain direction of CMG is close to singularity, in the corresponding direction RW is away from Singular, but RW may approach singularity in other directions as well)

Images