Structured control for a satellites platoon formation in low Earth orbit using Youla-parametrization

Abstract

The paper presents the design and analysis of a control strategy appropriate in the case of two or more spacecrafts in low Earth orbit and in close along-track configuration. The well known dynamics of the relative motion are briefly recalled and their decoupling properties allow to restrict the multivariable control design to an in-plane problem. An H∞ synthesis is used to obtain a control law for a formation of two satellites. The control of a formation of four satellites, in the case of local measurements between each satellite and the preceding one, falls in the framework of structured control. A Youla-parameter based technique (convex synthesis) allows to use convex optimization to improve the initial blockdiagonal structure derived from the two-satellites controllers, with a great flexibility to take into account frequency and time constraints.