Attitude control and momentum management of space station via weighted-state H<inf>&#x221E;</inf> method

Abstract

This study investigates the application of gravity gradient and aerodynamic torques in the attitude control and momentum management (ACMM) of the space station. Due to the large inertia and solar panels, environmental torque is significant enough in the ACMM in order to save fuel costs. Towards this end, the gravity gradient and the solar panels' aerodynamic models are established. The weighted-state H controller is designed since the attitude control sub-system is much slower than the momentum management sub-system. Numerical results are shown to demonstrate the practicability of the environmental torque application and the effectiveness of the weighted-state H technique.

Uncertainties and Design of Active Aerodynamic Attitude Control in Very Low Earth Orbit

“…The greatest challenge, when implementing active aerodynamic attitude control, is addressing the uncertainties that characterise the problem formulation. The majority of studies propose to achieve aerodynamic attitude control by selecting the angles of rotation of allocated aerodynamic control actuators [4,[9][10][11][12][13][14][15][16]. A simple and quick way of estimating the control torque is obtained by assuming small attitudes with regards to the incoming flow and limited ranges of deflection of the panels so that approximate linear laws can be used [4,[9][10][11][12]16].…”

“…The majority of studies propose to achieve aerodynamic attitude control by selecting the angles of rotation of allocated aerodynamic control actuators [4,[9][10][11][12][13][14][15][16]. A simple and quick way of estimating the control torque is obtained by assuming small attitudes with regards to the incoming flow and limited ranges of deflection of the panels so that approximate linear laws can be used [4,[9][10][11][12]16]. Alternative approaches see the implementation of an optimal control problem to find the time-varying position of the panels to minimise a desired cost function [14], or the use of truncated Fourier series [17] to obtain an estimation of the aerodynamic torques.…”

“…Alternative approaches see the implementation of an optimal control problem to find the time-varying position of the panels to minimise a desired cost function [14], or the use of truncated Fourier series [17] to obtain an estimation of the aerodynamic torques. In order to privilege the demonstration of the control concept, some studies assume in first approximation time-invariant aerodynamic coefficients and neglect the small contribution due to the aerodynamic lift to the computation of the aerodynamic torques [9,10,15]. For the computation of the aerodynamic coefficients, most investigations generally assume diffuse re-emission with complete [9] or incomplete [4,11,14] accommodation of the particles to the surface, or include some specular re-emission component by applying partial accommodation theory [12,16].…”