SU1497610A1 - Apparatus for shaping a spectrum of random vibration - Google Patents

Abstract

The invention allows to form a spectrum of random vibration with automatic maintenance of a given spectral density on vibrating tables. The purpose of the invention is to improve the formation accuracy. This is achieved by the fact that in each channel of the imaging unit the same filter performs the functions of both the shaping and analyzing filters. The filter is made in the form of a third circulator, the first input of which is the simultaneous input and output of the filter, and its second and third inputs are connected respectively to the input and output of the narrow-band filter based on a reversible amplifier, the input and output of which is invariant. To compensate for the analyzed signal in the formation path, and the generated one, the corresponding inverters and adders are introduced in the analysis path.

in addition, the first and second circulators are introduced. 1 il.

Description

The invention relates to vibration testing of products, namely, devices for forming a spectrum of random vibrations with automatic maintenance of a given spectral density on vibrating tables.

The aim of the invention is to improve the accuracy of forming a spectrum of random nibrations.

The drawing shows a block diagram of the proposed device.

A device for forming a spectrum of random vibrations contains parallel formation channels, each of which consists of a series-connected noise generator 1, an adjustable amplifier 2, a first-time circulator 3, a filter 4, a second circulator 5, a second adder 6, a second inverter 7 , the first adder 8, the first inverter 9, the output of which is connected to the first input of the second adder 6, the output of which is connected to the series-connected common adder 10, the amplifier 1 1 power, the vibrator 1 2, on s, the tolerance of which ene vibration sensor 13, whose output is connected to a third input of the second circulator 5 forming each channel and the third input of the second adder 6, series-connected dispersion meter 14, an input connected to the output of the first adder 8, and the comparison unit 13

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LIA, the output of which is connected to a control amplifier with adjustable amplifier 2, in, which is connected to the second input of the first adder 8,

In this case, the filter 4 consists of a third circulator 16, the first output of which is simultaneously the input and output of the filter 4, and its second and third terminals are connected respectively with the input and output of the narrowband filter 17.

The device works as follows.

The signal from the noise generator 1 — the first wideband signal — is fed to the adjustable amplifier 2. From the output of amplifier 2, amplified K times the first wideband signal to the first output of the first circulator 3, from the second output of which is fed to the input of the filter 4. The input of filter 4 is at the same time the first output of the third direction switch 16, from the second output of which the signal enters the input of the narrowband filter 17, the latter amplifies the components of the first wideband signal at the resonant frequency.

Thus, the first narrowband signal from the output of the filter 17 goes to the third output of the third circulator 16 and then through the first second of the latter to the first end of the second circulator 5, Since at the resonant frequency of the narrowband filter 17 - there is no phase shift, in the first output of the second circulator 5, the first wideband signal from the second output of the first circulator 3 is summed with the narrowband signal from the first output of the third circulator 16. Since the level of the first broadband signal is relative to the nodes Rinse the signal output of narrowband filter 17 is small, the further their sum signal will assume the second narrowband signal

Thus, the second narrowband signal through the first output of the second circulator 5 is fed to the second output of the circulator 5 and then to the second input of the second adder 6, from the output of which the second narrowband signal enters the input of the common adder 10.

On the common adder 10, it is summed with a friend of the second narrow-band sig nals of similar

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canonon form psh. As a result, a broadband signal is obtained at the output of the total of 10 chips - a second wideband signal. This signal is then amplified by the power amplifier 11. With B, the latter goes to the vibrator 12, which converts the input electric signal into mechanical oscillations, which, in turn, are converted by the vibration sensor 13 into an electrical signal fed to the parallel formation channels, which for the signal from the vibration sensor I3 are analysis channels. Since the channels are similar, consider the work of one channel. The second broadband signal from the vibration sensor 13 is fed to the third input of the second adder 6 and to the third output of the second circulator 5, from the first output of which is fed to the first output of the third circulator 16. From the second output — the last second broadband signal goes to the input of the narrowband filter 17, where it is filtered. At the output we have a narrowband signal that characterizes the frequency response of the vibrator path - a product in this frequency band. The third narrowband signal from the output of the narrowband filter 17 is fed to the third output of the third circulator 16 and then through the first output of the third circulator 16 to the second output of the first circulator 3, where it is summed with the second wideband signal. This sum signal - the fourth narrowband signal (by analogy with the second narrowband signal) goes through the second output of the first circulator 3 to its third output and then to the third input of the first adder 8. the signal power is measured in the band of the narrowband filter 17.

From the output of the dispersion meter 14, the signal in the form of a constant voltage is passed to the comparison unit 15, where the signal is compared with a given spectrum value Gj .. The error signal from the output of the comparison unit 15 is fed to the control input of the adjustable amplifier 2,

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Yam of the Raisnin mouth of the Gstemepchsko error of measurement} 1 and due to the penetration of the first signal on the formation of the second first inductor 3 — the third output of the first pyro 3 — the second input of the first adder 8 the second narrowband signal from the output of the second adder 6 enters through the second inverter 7 to the first input of the first adder 8. Thus, at the first input of the first adder 8 we have an inverted second narrowband signal, at the third input - the first narrowband signal, at the second input - the first wideband signal th signal.

Obviously, at the output of the first adder 8, the sum of the first narrowband and first wideband signals is mutually compensated with the second narrowband shaping signal,

Similarly, the analyzed signal is compensated in the path of formation of the first output of the second circulator 5 - the second output of the second circulator 6 - the second input of the second adder 9 - the second input of the second adder 6. At the first input of the second adder 6 there is an inverted fourth narrow-band signal

the second entrance - the third narrowband

signal, on the third - the second broadband signal. At the output of the second adder 6, these signals are mutually compensated.

Thus, the implementation of the device for forming a spectrum of random vibrations does not cause fundamental difficulties, and its use allows vibration tests to be performed with high accuracy in forming the required vibration spectrum.

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ABOUT

Claims (1)

Invention Formula A device for forming a spectrum of random vibrations containing parallel channels of formation, each of which consists of a series-connected noise generator and an adjustable amplifier, a filter, a first adder and a series-connected dispersion meter and a comparison unit, the output of which is connected to the control input of the adjustable amplifier, as well as A common adder, a power amplifier and a vibrator, on the table of which a vibration sensor is placed, characterized in that, in order to increase The first inverter, the second adder and the second inverter connected to the first input of the first adder, the output connected to the inputs of the first inverter and the dispersion meter, as well as the first and second circulators, and the first output of the first circulator connected to the output of the adjustable amplifier and the second input of the first adder, the second output - with the filter output and the first output of the second circulator, the third output - with the third input of the first adder, the second output of the second The second circulator is connected to the second input of the second adder, and the third output is connected to the output of the vibration sensor and the third input of the second adder, the outputs of the second adders of all channels are connected to the inputs of the common adder, and the filter is made as a third circulator, the first output of which is the output of the filter and a narrowband filter connected to the second output of the third circulator, and the output to the third output of the third circulator. Uyl