A Systematic Robust Control Design and Verification Approach for Drag-free Space Missions

A systematic and iterative framework for robust control design and verification, tailored to critical drag-free space missions, is presented. The main contribution of the work consists of integrating well-established H-infinity and mu-based tools within a unified hierarchical design and verification workflow specifically devised for drag-free applications, in which the design complexity is progressively increased from decoupled single-input single-output synthesis to multi-input multi-output robust refinement only when required by the verification results, thereby limiting unnecessary controller complexity, while systematically addressing mission-level stability and performance requirements. By integrating linear robustness analysis with parametric uncertainty considerations, the framework provides a systematic procedure to assess drag-free compliance with mission-critical constraints and is applied to the robust control design and analysis of the European Space Agency missions LISA and NGGM. Numerical simulations confirm the effectiveness of the approach, highlighting its adaptability and potential application to future advanced drag-free space missions.