Cascaded strapdown line-of-sight stabilization for Risley prisms on motion platforms
Hongfeng Xia, Huayang Xia, Liangzhu Yuan, Piao Wen, Luo Xun, Qiliang Bao, Yihan Luo, Jinying Li · Applied Optics · 2025
A cascaded strapdown line-of-sight (LOS) stabilization and tracking method based on Risley prisms is proposed to address the challenge of maintaining image closed-loop stability in the presence of platform attitude disturbances. First, this paper introduces the Risley-prism coordinate system and the inertial space coordinate system, and then analyzes the disturbance coupling between LOS and the platform, superimposing the platform’s attitude disturbance onto the target position motion. By utilizing an inverse calculation model, the system achieves suppression of platform disturbance. Specifically, a method is proposed to compensate for residual disturbances and enable image closed-loop tracking by integrating a fast-steering mirror (FSM) with the Risley prisms’ LOS stabilization system. The coupling relationship between the FSM and the residual disturbances from the Risley-prism system is established to facilitate real-time compensation. Finally, a simulation and an experimental platform were developed to validate the effectiveness of the proposed cascaded strapdown LOS stabilization method for Risley prisms. From the simulation and experimental results, the disturbance suppression ratio is improved by about −12dB at 1 Hz.