Robust Collocated Control of Large Flexible Space Structures

Agile maneuvering and precise pointing control require special attention for spacecraft equipped with large flexible appendages. A joint academia-industry research involving Sapienza University of Rome, Thales Alenia Space in France and the European Space Agency (ESA), investigates the use of innovative solutions to counteract the deterioration in pointing accuracy stemming from interactions between a rigid bus and the flexible structures during operations. Specifically, this paper aims at presenting the design of an attitude/vibration control architecture in a μ-synthesis framework. The architecture consists of an attitude control system combined with a distributed network of actuators/sensors at structural level for active vibration control purposes. A spacecraft equipped with an interferometric Ka-band SAR payload and two solar arrays is considered as a useful and challenging benchmark problem to assess the proposed methodology. The numerical simulations, carried out via both a linearized setting and a nonlinear simulator, have proved the effectiveness of the robust collocated control in comparison with a baseline PID controller.