FEATURES OF IMPLEMENTATION OF THE SPECTRAL ANALYSIS METHOD FOR PROCESSING VIBRAOACUSTIC CONTROL DATA

Problem statement. The main trend in the development of vibroacoustic technology for monitoring geotechnical objects is aimed at automating the receipt, transmission, collection and processing of information. However, the mathematical apparatus and algorithms for digital processing of vibroacoustic signals require further development. Purpose of the study. Definition of features and development of algorithms for the implementation of the spectral analysis method for vibroacoustic monitoring of the geotechnical system functioning safety. Methods. Analysis and generalization of data, analytical and laboratory studies of acoustic signals oscillograms, methods for constructing digital environmental control systems. Research results. The methods and algorithms used in systems for monitoring the state of rocks, mine workings, underground and surface structures are investigated. Digital signal processing algorithms usually include filtering and spectral analysis of input data. The features of the spectral analysis method implementation for processing vibroacoustic monitoring data of a geotechnical system are determined. It is established that a decaying aperiodic signal can be considered as a superposition of multiplications of imaginary periodic signals and shifted single rectangular pulses. In this case, the frequency of the first oscillation mode is inversely proportional to the double thickness of the studied elements of the geotechnical system. To control the characteristics of pulsed acoustic signals, in contrast to the previously known method, which uses one measurement during the partition interval and manual construction of point fields, it is proposed to use a series of points at each of the time intervals of signal change and analyze the relationships between the spectrum of the real aperiodic signal and the spectra of its imaginary periodic components. Algorithms for automatic analysis of vibroacoustic response spectrograms and calculating control parameters using the discrete ordinate method are developed. The method is implemented by sequential cyclic processing of the signal from high frequencies to low frequencies, followed by division into time intervals, within each of which the change in the deviation value is taken as the period of the unquenchable oscillatory process. Scientific novelty. The methodology for identifying hidden damage in structural elements of buildings and structures has been further developed, which is distinguished by taking into account the parameters of vibroacoustic control of the destruction consequences and assessing the risks of the structures stability loss. Practical significance. The research results make it possible to improve the method for assessing changes in the structure of the medium as a result of the occurrence of observed and hidden systems of cracks using vibroacoustic monitoring.