Robust momentum manager controller for space station applications

Abstract

An innovative methodology to design a robust Control Momentum Gyro (CMG) momentum manager for the International Space Station (ISS) is developed. Unlike most other momentum manager designs, which use either a Linear Quadratic Regular (LQR) or mu-synthesis technique, the proposed methodology is based on the Nash differential game theory. This approach accounts for both a robustness specification in terms of the gain/phase margins, and a time domain requirement, such as the maximum CMG momentum. An inverse solution procedure is used to recast the original coupled Algebraic Riccati Equation (ARE) problem to a constrained optimization problem. Further, the dynamics used in this momentum manager design are linearized for any operating point, including the Torque Equilibrium Attitude (TEA), as opposed to only the Local Vertical and Local Horizontal (LVLH) frame. Design examples are provided to demonstrate the practicality of the proposed methodology, and the results are favorable