ERRORS IN DIGITAL PROCESSING OF SIGNALS IN VIBROACOUSTIC DIAGNOSIS

Abstract

The modern stage of development and use of diagnostic tools is characterized by intensive computerization. Computer technology is used at all stages of designing diagnostic systems, but, of course, it plays the main role in the process of processing and analyzing diagnostic information. Vibrodiagnostics is based on measuring the characteristics of vibration processes (displacement, speed or acceleration) that are formed during the interaction of parts of a working machine or mechanism, and their analysis by various methods. The vibroacoustic signal has a complex structure that depends on the dynamics of the mechanism, as well as the type and nature of the interaction of the nodes that make it up. Acceleration is a derivative of speed and can be used to assess the tendency of a machine's technical condition to change. The change in the amount of movement (amplitude of vibration) in the frequency spectrum is used in the tasks of finding various defects. The vibroacoustic signal has a complex structure, contains a useful component and an obstacle that prevents accurate recognition of the information contained in the signal. In addition, distortions occur when the diagnostic signal passes through the channels from the source to the sensor. The mathematical model of the vibroacoustic signal obtained during the vibroacoustic diagnosis of machines is presented in the article. It was determined that the time function s(t) specified in the interval [0, T] serves as a mathematical representation of the signal, which will be used to consider methods of its transformation in order to highlight its parameters and diagnostic features. The ability of the signal to provide information about the state of the object is due to the fact that some of its properties can change depending on the state change. In order for the diagnostic problem to be solved, different signals must correspond to different states of the object, and this correspondence must be mutually unambiguous.