SU615364A1 - Vibration spectrum analyzer - Google Patents

Description

The invention relates to a measurement technique and can be used in various fields of technology when analyzing with a spectrum of vibrations, for example, in measuring the dynamic characteristics of machine tools.

A device for measuring cneKT ia vibrations is known, comprising a generator, a narrow-axis electromechanical tuning fork sensitive to external vibrations and a recording instrument l.

A disadvantage of this device is the low accuracy of the spectrum analysis.

The closest in technical essence to the described is a vibration spectrum analyzer containing a quadrature generator, a quadrature signal generating unit, the inputs of which are connected to the outputs of a quadrature generator, a measuring transmitter, a phase meter, a level indicator and two measuring channels, each of which contains a synchronous detector, signal inputs of synchronous detectors are connected to the output of the measuring converter

vibrations, and the control inputs to the outputs of the quadrature signal shaping unit J2j.

The purpose of the invention is to improve the accuracy of the analysis of the spectrum of vibrations.

This is achieved by the fact that the proposed analyzer is equipped with an adder and serially connected low-pass filters and an additional synchronous detector are introduced into each of the measuring channels, the input of each of the low-pass filters is connected to the output of the corresponding synchronous detector, the control input of each additional synchronous detector is connected to the quadrature output generator, the adder inputs are connected to the outputs of additional synchronous detectors, the output of the sum of the torus is uniformly connected to the input of the indicator ur A ram is connected to the signal input of the phase meter, and the control input of the phase meter is connected to the output of the square of the generator.

Claims (1)

The drawing shows a structural diagram of the proposed analyzer. The spectrum analyzer B {| (6ratsy consists of a quadrature generator 1, to the output; the dam of which is connected to the quadrature formation unit 2, the meter of the transducer. 3 vibrations and two measuring channels, each of which contains a synchronous detector 4 or S, the signal inputs of which connected to the output of the converter 3, and the control inputs to the outputs of block 2, serially connected low frequency 6 or 7 and an additional synchronous detector 8 or 9. Control inputs of the additional synchronous detectors 8 and 9 are connected to the outputs of the quadrature generator 1, the outputs of the detectors 8 and 9 are connected to the adder 10, to the output of which the phase meter 11 and the level indicator 12 are connected. The control input of the phase meter 11 is connected to one of the outputs of the generator 1. The analyzer operates as follows From the outputs of the quadrature generator 1, which operates at a certain fixed frequency fo, the orthogonal signals arrive at the inputs of the quadrature signal generating unit 2 and Up-co52 rf gt. and ' 1K, 2K | „. In block 2 of the quadrature signal generation, these signals are mixed with the variable frequency generator signals (not shown in the drawing), and the difference frequency fp corresponding to the first harmonic of the signal under study is extracted using low-pass filters ( not shown in the drawing). Thus, signals from the outputs of unit 2 to the control inputs of synchronous detectors 4 and 5, respectively, are received — i-Sin 2ltfp-t and U-C05 I At the same time, the analyzed signal of the type hp is fed to the signal inputs of synchronous detectors 4 and 5 from the output of the vibration measuring converter 3 / ... Z (121rfpt fЛ. T-1 At the outputs of synchronous detectors 4 and 5, the following signals are obtained, respectively: -j-UX cosVf --UX Cos2-2ir pt H-SX.sin (i2irf.) U & in2-R: jE-, i,, V. V P i; P-JUX, sin f -YUX S1nX Uco-212G p. n / .l fe. X S-tn M.-tW). (l .. OCG + After filtering at the outputs of the filters in and 7 low frequencies remains only for one component of the signal:,, -i-UX Comb and-i-UX einSi and all the other harmonics are captured. These signals are sent to the signal inputs of a pair of additional synchronous detectors 8 and 9, to the control inputs of which from the outputs of the quadrature generator 1 signals are sent Fqx pd. Uo-5in2irfot and UQ cos frequencies. At the outputs of additional synchronous detectors, signals appear from them — and – costoftfot,, - | –UX, 6inM UoSin2ir ot. As a result of the addition of these signals, a signal, u-UoX, cos, appears at the output of sum | aa 10 (i.e. a signal proportional to the amplitude XJ of the harmonic under study, measured by a level indicator 12, is obtained at the output of summer 10. In addition, This output signal stores information about the phase of the harmonic under investigation (in this case, H), to measure this phase, it is enough to send a signal UUoX CosC2R oi- 4) to the signal input of the phase meter 11, and to the control input give a signal with one of the outputs of the quadrature generator 1, for example, the signal UQ Сое 2} rfo t. Then the phase meter will show the value of the phase P1 {. Thus, a full amplitude and phase analysis of the signal under investigation is carried out, and the amplitude and phase of the studied harmonic are simultaneously recorded, which currently coincide in frequency with the signal generated by the quadrature reference signal generator. The frequency of the latter can manually change the vuia automatically when the frequency of the variable frequency generator changes. All measurements are made at one fixed frequency. This increases the noise immunity and allows the analyzer to be used directly in the workshop conditions for dynamic testing of machines. DETAILED DESCRIPTION OF THE INVENTION pppup