Formation patterns and robust cyclic pursuit approach for space-based radiography

This paper firstly puts forward a novel concept of space-based radiography which could be used to detect the interior of spacecraft, and investigates the relevant four kinds of formation patterns with application to the disabled spacecraft, i.e., patterns of external structure reconstruction, with the same or different relative orbit, with the spiral relative orbit. Taking advantages of the cyclic pursuit theory and the extended state observer (ESO), the three kinds of pursuit strategies and the robust coordinated cyclic pursuit controllers of each formation patterns are designed. In addition, the tuning method and formulation of controller parameter with respect to the required formation pattern are also derived and presented. Simulation results verify that the cyclic pursuit controller could enable all required formation patterns with certain robust capability, which could be enhanced by the feedback compensation of ESO-based estimates.