Analysis of the Inertial Acceleration of a Shipborne Telescope Tracking Frame and Experimental Device Construction

Shipborne photoelectric telescopes must consider the influence of the ship on structural stability during offshore operations. In this study, a 1.2 m shipborne photoelectric telescope tracking frame was investigated, and the inertial acceleration induced by hull motion was analyzed. Three ship motion modes were simplified as independent harmonic motions, and their motion equations and parameters were derived. The structural deformation under combined ship motions was evaluated by applying inertial loads through finite element analysis. The maximum deformations along the altitude axis parallel and perpendicular to the bow-stern line were both less than 0.09 mm, indicating negligible structural impact. A ship motion simulation system was developed and validated using an LMS modal analyzer. Modal analysis was performed to obtain the first six mode shapes, and sensor locations were optimized accordingly. The measured frequencies of the first six modes were 43.10, 47.47, 62.76, 74.52, 126.84, and 146.32 Hz, respectively, with the fundamental frequency exceeding the simulated value of 34.32 Hz.