Image stabilization of airborne inertial stabilization platform using fast steering mirror

One of the most important missions of an airborne inertial stabilization platform (AISP) is to acquire the image of the target with high resolution. It is challenging for the AISP to acquire such high-quality images because the AISP is continuously exposed to a significant level of vibration from the airplane, which is transformed into exogenous disturbance torque. As a consequence, the AISP suffers line-of-sight jitter that undermines the image quality. Although the conventional mass stabilization system is capable of rejecting exogenous disturbance torque only within a low frequency band, the introduction of a fast steering mirror (FSM) can significantly expand the disturbance rejection capacity. This paper describes how the introduction of the FSM improves the image stabilization capacity. On top of the conventional mass stabilization system of gimbaled mechanism with inertial sensor feedbacks, we implement the FSM that covers high frequency band within the optical path from the telescopes of the AISP to its image sensor. A high gain FSM controller is designed through the loop-shaping method and applied to the piezo-electric actuator driven FSM, which shows a sufficiently high bandwidth for rejecting the exogenous disturbance of our interest. The results from both actuation data and acquired images demonstrate the effectiveness of the FSM in the image stabilization of the AISP.