Active microvibration control of an optical payload installed on the ARTEMIS spacecraft

This paper presents a feasibility study for the vibration control of the SI LEX optical payload installed on the European ARTEMIS advanced telecommunic ation satellite. Due to its stringent pointing requirements (being approxim ately a few microradiants) the payload is particularly sensitive to the tra nsmitted microvibrational disturbances. The vibration suppression problem h as been addressed using piezoceramic strain actuators bonded to the payload support structure and designing a high contra! authority linear quadratic compensator. The plant mathematical model was obtained through a NASTRAN fi nite element modeling of the payload structure equipped with the surface bo nded piezoceramic strain actuators. This high order evaluation model has su ccessively been reduced to a lower order design model using static condensa tion (Guyan) and modal reduction techniques. Different criteria have been a pplied in order to check for the controllability of the system. The LQR com pensator design was based on the minimization of a quadratic performance in dex of state and control vectors which included the output behavior. A comp arison between the open and dosed loop system behavior was carried out for different disturbance inputs and different control weights.