Vibration rejection of phased array telescope systems via disturbance-propagation-characteristics-based feedforward control

Abstract

Vibration rejection is one of the key techniques to stabilize the line of sight (LOS) for phased array telescope systems. Conventionally, feedback control based on image sensors is mainly used to correct the tip/tilt errors caused by disturbances and to keep the LOS stable. However, it is restricted by the sampling rate and time delay of image sensors, leading to a limited closed-loop bandwidth. Disturbances in the middle and high frequencies are hard to suppress. In this paper, disturbance-propagation-characteristics-based feedforward control is proposed to overcome these problems. A theoretical imaging model of the phased array telescope is developed to analyze the LOS disruption caused by disturbance. In addition, to improve the disturbance suppression bandwidth and correction accuracy of the system, the disturbance propagation characteristics of the phased array telescope system are analyzed. Combined with the disturbance feedforward, targeted compensation is achieved for the sub-apertures. Finally, a comparative experiment is carried out based on the self-developed Fizeau phased array telescope system to verify the superiority of the proposed method.