Modeling of the thermal regime of a platformless navigation system with thermal stabilization of accelerated warm-up

Abstract

Currently, platformless inertial navigation systems (IBS) based on fiber optic gyroscopes (FOG) are widely used in modern aviation and space technology. In connection with the high sensitivity of VOG to the influence of temperature changes, ensuring stable thermal modes of operation is an urgent problem. The most important task of increasing the accuracy of system operation is the development of methods of thermal protection and thermostabilization of VOG. The work is devoted to the modeling of the temperature field of the platformless inertial unit (BIB), which is part of the BINS, in order to ensure a minimum temperature difference on the VOG platform with the use of thermal stabilization. The purpose of the work is to simulate the temperature field of the BIB measuring unit and determine the conditions that ensure a minimum of temperature differences on the VOG platform under thermal stabilization conditions. To achieve the goal, the following tasks were solved: creation of a calculation scheme and finite element model of the BIB device, modeling of the effect of changes in external temperatures on the temperature field of the BIB device, numerical determination of temperature gradients at given points of the device. According to the results of numerical modeling, the parameters of the temperature field of the device and the characteristics of the thermal stabilization system were studied. The thermal mode of the device with a thermostabilization system for accelerated heating and reduction of temperature change gradients on VOG sensors with a governing law corresponding to base temperature changes is considered. The temperature gradients at the given points of the device are numerically determined. It was established that the law of thermostabilization should ensure the stability of the temperature field (the smallness of the temperature gradient). The value of the VOG temperature itself does not have a significant effect on the amount of drift. It is advisable to use the thermal stabilization system only to bring the system to the working temperature mode for no more than 30 minutes, and not to use it in the working mode.