СИСТЕМА ДЛЯ ОЦЕНОК ИЗНОСА СТВОЛА ПО ДАННЫМ ИЗМЕРЕНИЯ ЕГО ДЕФОРМАЦИЙ С ИСПОЛЬЗОВАНИЕМ АДРЕСНЫХ ВОЛОКОННЫХ БРЭГГОВСКИХ РЕШЁТОК
Authors: Куликов Е.В. , Сахабутдинов А.Ж. , Липатников К.А. , Кузнецов А.А. 
Published: February 2025

Представлена структура и оценки метрологических характеристик многосенсорной системы мониторинга живучести ствола в реальном масштабе времени. Система является радиофотонной и построена на основе адресных волоконных брэгговских решёток (ВБР). Сформированные в ВБР оптические сигналы о сдвиге центральной длины волны, вызванные деформацией ствола при прохождении вдоль него снарядов, преобразуются системой в пригодные для последующей обработки информативные сигналы радиодиапазона. Использование такой радиофотонной системы позволяет снять ограничения, присущие существующим беспроводным системам мониторинга живучести ствола, связанные с чувствительностью к электромагнитным помехам, и волоконно-оптическим системам, связанным с использованием дорогих, вибро неустойчивых интеррогаторов (систем опроса классических ВБР). Как показали оценки, максимальная погрешность определения положения адресной ВБР в системе составляет не более 8 МГц, что приводит к ошибке в определении её центральной длины волны, вызванной деформацией, порядка десятых долей пикаметра или десятых долей микрострейн при пересчёте в значения деформации.
Introduction. When firing from a gun, the barrel wears (suffers from abrasion and erosion) and barrel deterioration occurs. This ultimately leads to the inability of the gun to ensure aimed shooting or to its sudden breakdown. Therefore, the problem of creation of systems for monitoring the gun barrel life is crucial and still unsolved. The aim of the research was the development of the microwave photonic multi-sensor system for monitoring barrel life with the use of the sensors that are based on the addressable fiber Bragg gratings (AFBG) as the deformation sensitive elements and measuring system that consists of fiber-optic and electro-optic components for converting signals generated by the sensors into informative radio-frequency signals appropriate for further processing. Designing the system, we identified requirements and evaluated several configurations to achieve an appropriate design that should be attached to the barrel. Optimally, the design consists of several AFBG of a reflective type FBG of notch filter type with an inclined characteristic narrowband laser source providing a range of illumination of the AFBG and the filter corresponding to a temperature change from -100 to 400 С as well as splitter and photo detector. The design can be implemented both on waveguide gratings and in integral design. The FBG of the notch filter and the emission bandwidth of the laser diode, taking into account the range of possible temperature deviations and pressure wave impulses, should be 4-6 nm. The rate of change of the deformation amount will be monitored by controlling the modulation coefficient of the envelope at the beat-note frequency of each AFBG in its specific position relative to the filter characteristic, which varies depending on the size and sign of the deformation. Besides, a change of 0.5 nm/mcs does not influence beat-note frequency, that is constant, and, therefore, does not require a wideband direct current receiver. Practical significance. Such microwave photonics system allows to overcome limitations of the existing wireless systems for monitoring barrel life, related to electromagnetic interference sensitivity as well as to eliminate the drawbacks of fiber-optic systems, associated with the use of expensive, vibro-unstable interrogators (interrogation systems of classical FBG). Findings. The developed block diagram of the system contains a base optical fiber, consisting of a reflective-type AFBG for measuring axial deformations ez of the barrel, as well as radial er and circular deformations e along the barrel profiles, placed on orthogonal fibers that are connected to the base fiber through the optical splitters. Experimental model results show that the proposed system more effectively detects deformations than systems with strain sensor or classical FBG. According to the estimates, the maximum error in determining the position of the AFBG do not exceed 8 MHz. That results in an error in determining central wavelength of the order of tenths of a pica meter or tenths of a micro strain in terms of strain values. It is an order of magnitude better than the similar parameter of the existing systems.