DIGITAL MULTIPLIER-CONVERTING METHOD FOR MEASURING FREQUENCY INSTABILITY USING THE LABVIEW PROGRAMMING ENVIRONMENT

Abstract

The article is aimed at measuring the parameters of the harmonic process by the multiplication- conversion method. The simulation was carried out through the use of the LabVIEW software environment, as applied to the digital multiplier-conversion method, the main points of which are presented in the form of a progressive chain: a) development of the first harmonic process; b) the multiplication of the indicator of the first harmonic process by four; c) the arrival of to the band-pass filter PF1 tuned to the highest frequency, in this case, d) simultaneously, using the generator Г2, a second source signal is generated; e) This oscillation is raised to the fifth power, f) using the filter PF2 tuned to a frequency of 5 , select the fifth harmonic g) The signals received at the outputs of the filters are added and the result of the sum is subjected to nonlinear transformation h) Then, from the resulting square of the sum of the signals and using a band-pass filter PF3, we extract only the low-frequency harmonic with the frequency i) Then, using the Hilbert transform, we extract the total instantaneous phase from the harmonic and it becomes the object of the derivative operation, which leads us to obtain the instantaneous frequency function, characterized by a fixed dispersion. j) The law of fluctuations of the frequency resulting from the use of multiplication-conversion operations is compared with a given frequency, and we proceed to determine the mathematical expectation and standard deviation. The conclusion about the frequency instability is based on the discrepancies obtained. Applying nonlinear transformations of oscillations of oscillators similar in instability and obtaining the oscillations of a given frequency in the same way, the measured frequency instability is established. If you apply this method many times to the oscillations of highly stable devices, you can develop an oscillation with increased instability, and then evaluate it with available measuring equipment. Thus, we bypass without high costs by performing this operation. Then, determine the initial instability by the formulas given in this article.