Определение допустимых амплитуд вибрации основания бесплатформенной инерциальной навигационной системы

Abstract

In modern aerospace technology, strapdown inertial navigation systems (SINS) based on fiber-optic gyroscopes (FOG) are widely used. SINS vibrations that violate the direction of the gyro sensitivity axes require a separate analysis for each specific arrangement of SINS systems using FOG. When performing research on the creation of a strapdown SINS based on OIUS501 gyroscopes, it became necessary to determine the maximum permissible amplitudes of external vibration impact for a specific configuration of the SINS unit assembly. The aim of the work is to determine the maximum permissible vibration amplitudes acting on the SINS body, according to the permissible values of the deviation of the FOG sensitivity axes. The solution of such a problem requires the use of modern numerical methods, for example, the finite element method (FEM). To achieve this goal, the following tasks were solved: the development of a design scheme and a finite element model of the SINS, modeling the influence of an external vibration effect on the deviations of the sensitivity axes, determining the maximum permissible values of the amplitudes of external vibration effects in the operating frequency range. The design scheme, mathematical and finite element models for calculating natural frequencies and forced vibrations of a strapdown inertial navigation system block are presented. In various frequency ranges, the limiting values of the amplitudes of the external harmonic action on the basis of a specific configuration of the SINS assembly are determined by calculation. It has been established that the value of the limiting amplitudes of external influences at operating frequencies is quite large, and a relatively low level of permissible vibration amplitudes occurs in the region of higher frequencies.