SU1411589A2 - Bed for preparing vibration-measuring circuits for natural tests - Google Patents

Abstract

The invention relates to a measurement technique and is designed to prepare vibration measurement paths, including a piezo sensor, measuring transducers and a recording system, to field tests in automatic mode. The aim of the invention is to increase the reliability of the operation of the stand by automating the operations of technical control and diagnostics. In the course of operation, the automatically assigned signal is fed to the vibration measuring path with a known number, and the output signal from the path is fed to the input of the 10-unit block and control of significant signal values, where the RAM contains predetermined characteristics and current values of the output signal from the path. Next, the analyzer 13 performs monitoring at specified time intervals and compares the parameters, which allows diagnosing possible malfunctions or their absence. 2 Il. SP

Description

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The invention relates to a measurement technique, and more specifically to test test vibration measurement systems, can be used, for example, when conducting field tests as part of the objects under study, and is an improvement of the invention according to author. No. 767553.

The purpose of the invention is to increase the reliability of the stand by automating the operations of technical control and diagnostics.

Fig. 1 shows a structural diagram of the stand, Fig. 2 shows successively the time diagrams of a signal at the output of a variable frequency current generator, at the output of a fixed frequency current generator, a signal at the modulator output, and pulse following at the output of a clock pulse generator.

Stand for the preparation of vibration meters

The body paths for field tests consist of piezo sensor 1, amplifier 2 and recording system 3, which form a vibro-measuring path, connected in series. The input of the amplifier 2 is connected via an additional capacitor 4 to the output of the modulator 5, the first input of which is connected to the generator 6 of a fixed frequency current, and the second input to the generator 7 of a variable frequency current. The generator 6 is also connected to the information input of the quantization unit 8. The service (control) input of the quantization unit 8 through the shaper 9 clock pulses is connected to the output of the generator 7. The speeds of the recording system 3 and the quantization unit 8 are connected respectively to the first and second inputs of the allocation and control 10 essential values of the signal removed from the output of the vibration measuring path , and in the composition of the block 10 includes a storage device. The output of the modulator 5 is also connected to the first input of the electronic switch 11, to the second and third inputs of which the outputs of fixed and variable frequency current generators are respectively connected. The address control inputs of the switch 11 are connected to the outputs of the decoder 12 of the address code, the outputs of which are connected to the address control of the CC1TM outputs of the analyzer 13 of the amplitude-modulated signal8

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five

5 0 5 p

It computes the execution of computational operators according to a given algorithm and includes a processor and a persistent storage device. In this case, the first input of the analyzer 13 is connected to the output of the second quantization unit 14, and the second input and output to the corresponding output and input of the selection unit 10 and the control of significant values of the signal taken from the vibration measuring path. The information input of the second quantization unit 14 is connected to the output of the switch 11.

The stand works as follows.

The operational memory of unit 10 is preliminarily inserted into an information array containing, among other things, a set of previously calculated amplitude and frequency values of the control signal, corresponding numbers of vibration measuring paths to be prepared, time characteristics corresponding to the specified test program during the stand operation, a number of admissible the values and arguments of the function of the amplitude value of the signal E, having the form:

I eat EO (I + 1pz1p2Ya, t) -sin ("

H n), (1)

. one

where Ep is the amplitude of the output signal

generator 7

m is the modulation depth coefficient;

fj is the frequency of the signal at the generator output 6 °

f is the frequency of the signal at the output of the generator 7;

η is the initial phase of the signal at the output of the generator 7, t is independent variable. In the process of preparing the vibration measuring paths, the measurements from them through the modulator 5 provide a signal from generator 7 modulated by the signal of generator 6, the signal of which is in turn quantized by quantization unit 8 (Fig. 2). At the same time, the amplitude of the output signal of the modulator 5 takes a number of instantaneous values, among which, with some error, any E of the set of 10 control signals amplitude values for the i-path can be found in the RAM. The clock pulses, which are stored in the quantization block 8, are formed by converting the generator signal 7 using successively connected limiter, differentiating circuit, rectifier and delay line, which are supplied to the shaper 9, which provide a quarter of the oscillator signal 7 period.

As a result, on the output of block 8

analyzer 13 for tolerance control, as well as for subsequent comparison of the codes of these samples with the codes of the corresponding samples at the output of the quantization unit 8 recorded in the operational memory of unit 10 and read from this memory by the analyzer 13. In the case of a normal result

quantizing, the samples are formed, the MGNO-Q tolerance control and the comparison of the tested amplitude value of each of which coincides with the instantaneous amplitude value of the signal by. output modulator 5. Using block 10

Verification of the accuracy of the stand is completed.

In case of an abnormal outcome of the control using the analyzer 13, the levels of the received samples are measured and the tolerance control of the arguments is measured.

and determine the difference between the LU between the measured value of the sample level and the set value E of the calibration signal level of the i-path. At the same time, the operational memory of the block 10 is recorded-20, the sequence of current values of the signal taken from the output of the recording system 3. At the time of sampling with the corresponding

her value of the difference 4E, which is 25% of this

i

within the permissible error of path calibration, from the operative memory of block 10, the amplitude value of the control output signal of the recording system 3 is counted, by block 10, the fact that it is within acceptable limits and the operability of the path is fixed, after which it is fixed on the display media — graphically or alphanumeric printers.

All the listed operations for preparing the BT are repeated for all the frequency values of the control signal specified for this path.

The analyzer 13 monitors at predetermined real-time intervals the amplitude values of the E signal at the output of the modulator. This procedure is implemented both prior to the start of operation of the stand, and directly in the process of control and calibration of vibration measuring paths. For this, the analyzer 13 at its address control outputs generates a control address code to the input of the switch 11. In accordance with this address, the switch connects to the information input of the second quantization unit of the output circuit of the modulator 5.

Parallel binary codes of samples of the amplitude of the output signal of the modulator 5 are fed to the first input

Verification of the accuracy of the stand is completed.

In the case of an abnormal outcome of control, the analyzer 13 performs tolerance control of the arguments using the analyzer.

functions (1). Connecting the test bench circuits to the first input of the analyzer 13 is carried out similarly to connecting the output circuits of the modulator 5. In the case of an abnormal outcome of monitoring one or another argument of function (1), the value of this function is determined in accordance with the output (1) and substitution35

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Jq 45

50

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argument values. When coinciding with the specified tolerance of the calculated and measured value of E., the argument of the function (1), which went beyond the normal limits, is fixed in the documentation tools and, in order to diagnose a stand fault, indicates the failed block. In this case, the technical maintenance of the vibration measuring paths is stopped and resumed after the elimination of the malfunction. I The result of the preparation of the vibration measuring paths for field measurements is the family of calibration marks obtained for each path on the display means, each of which corresponds to a certain amplitude and frequency values that fall within the respective working path ranges.

Claims (1)

Invention Formula Stand for the preparation of vibration measuring paths for field tests by author. St. No. 767553, which is based on the fact that, in order to ensure the reliability of its work by automating the operations of technical control and diagnostics, a switch, a second quantizing unit, an amplitude modulated signal analyzer and an address code decoder were introduced into it, the inputs of which are connected to the address control outputs of the analyzer of the amplitude-modulated signal and the outputs are with the address control inputs of the switch, the first input of which is connected to the modulator output, the second and third inputs are respectively connected to the outputs of current generators of fixed and variable frequencies, the output is connected to information the input of the second quantization unit, the output of which is connected to the first input of the amplitude-modulated signal analyzer, the second input and output of which are connected to the output and input of the remote unit and the role of significant signal values.