Target-based line-of-sight stabilization in periscopes

This paper presents a novel method for target-based line-of-sight stabilization in periscopes with respect to disturbances in the platform movements. The platform can be a submarine or a tank. The disturbances can cause unstable images taken by the periscope and give altered information from the target, which can be located on the sea surface, on the earth, or in the air. To overcome this problem, a stabilization method is required to generate three reference signals for servomotors to remove the unwanted motion incurred on the image sequences. The stabilization equations, proposed in this paper, map the three-dimensional input space to the three-dimensional output space. The input space consists of the measurable pitch and yaw movements of the platform, and the target distance which can be measured or estimated. The output space consists of three reference paths. Simulation results show good results for the proposed method.