Comparison of the LQG and H-infinity techniques to design experimentally a flexible satellite attitude control system.

Abstract

Attitude Control System (ACS) for flexible space satellites demands great reliability, autonomy and robustness. These flexible structures face low stiffness due to minimal mass weight requirements. Satellite ACS design usually based on computer simulations without experimental verification can face instability and/or inefficient controller performance due to model uncertainties. In this paper one investigates the robustness and performance of the time domain approach LQG (Lineal Quadratic Gaussian) and the frequency domain H–Infinity approach. The satellite ACS design is performed initially in a computer simulation environment, following experimentally verification of the same control algorithm, using Quanser rotary flexible link module. This investigation has shown that the controller performance based on simulation model can be degraded when applied in an experimental set up. So this prototype verification is fundamental before satellite onboard computer algorithms implementation.