The work solves an important scientific and applied task – the development of a mathematical model and appropriate software for computer simulation of the interaction of light rays with sensitive fiber-diffraction elements of sensor systems for warning about the danger of fire damage by weapons that use laser systems for targeting.
The object of research is the interaction of light rays with polyaniline fibers of an diffractional sensor.
The subject of the research is mathematical models of the functioning of the signal element of the fiber diffraction sensor integrated into combat equipment
Scientific novelty of the work:
1. A mathematical model for the quantitative description of the interaction of 1D and 2D fiber diffraction gratings with laser radiation was developed.
2. For the first time, the appearance of diffraction bands in the form of scattered curves of the second order, whose shape caused by the phenomenon of conical diffraction and depends on the angle of incidence of the beam on the grating, which made it possible to develop the signal element of the fiber diffraction sensor.
3. For the first time, using the signal element of the fiber-diffraction sensor, the angular positions of the radiation source were mathematically determined, which made it possible to use the developed signal elements to build a system for detecting the radiation source and its positioning in one plane.
4. The characteristics of the polyaniline polymer fiber were studied. It is shown the possibility of using such a fiber for the formation of fiber-diffraction microsensors capable of detecting means of fire damage, in which directed laser radiation is used as a probing factor.
The practical significance of the obtained results is that they are directly used in the development of a physical prototype of the corresponding signal elements for the construction of a system for detecting means of fire damage and their positioning in relation to the signal element.
The work consists of an introduction, five chapters, conclusions, a list of used sources and an appendix.
The introduction provides the rationale for choosing the research topic; the goal, object, subject and tasks of the dissertation work are formulated; the scientific novelty and practical significance of the obtained results are reflected; the connection of the work with scientific programs, plans, topics and grants is highlighted. The acquirer's contribution, information on the approval of research results, a list of the acquirer's publications, the structure and scope of the work are also noted.
In the first section, an overview of fiber-diffraction sensors that can be used to diagnose various dangerous situations in real time is performed. A conclusion is made about the need for a new development capable of automatically establishing the fact of covert video surveillance and to find the location of the source of laser radiation.
The second chapter describes the results of experimental studies carried out in order to identify the features of the interaction of laser radiation with fiber diffraction gratings. Diffraction patterns were obtained depending on the fixed position of diffraction gratings.
In the third chapter, a mathematical model for the quantitative description of the interaction of a diffraction grating with laser radiation is proposed. It was found that when the grating is rotated to a certain angle, the result of the interaction of light with the diffraction grating is a diffraction band, which is a section of the diffraction cone by the plane of the screen. When the diffraction cone is intersected by the plane of the screen, the shape of the diffraction bands takes the form of second-order scattered curves. Numerical approximation of the diffraction bands for arbitrary angles of rotation of the diffraction grating was carried out using regression methods of data analysis.
The fourth section presents the results of digitization of experimental data. In the general analytical representation, the coefficients of the second-order scattered curves, which best describe the diffraction bands for conical diffraction on diffraction gratings, were obtained. The corresponding curves of the second order for the specified angles of incidence of the rays on the grating were determined by means of mathematical modeling. On this basis, the inverse problem was solved - determination of the angular coordinates of the laser radiation source.
In the fifth chapter, a variant of the practical implementation of a fire hazard warning system based on a fiber-diffraction sensor is proposed.
The created software based on the developed mathematical model of the interaction of laser radiation with a fiber diffraction grating is proposed for use in the development of a physical prototype of signal elements based on polyaniline fibers for the enemy detection system at "Tehprylad" LLC.