SU1711109A1 - Device for spectral-time analysis of signals - Google Patents

Abstract

The invention is intended to measure the spectral characteristics of wave signals of different nature: acoustic, seismic, etc., and can be used, in particular, in the study of heterogeneous media, geological surveys. The purpose of the invention is to increase the resolution and information content of the device by providing the possibility of a more accurate and unambiguous selection of the observed modes. The signal recorded on a magnetic medium in analog form is passed through a set of band-pass frequency filters and reproduced using spectrum recorders in the frequency-amplitude-time coordinates, the additional analog signal obtained is converted into a digital code, converted into a modified time scale in the form of T

Description

The invention is intended to measure the spectral characteristics of wave signals of various nature: acoustic, seismic and others, and can be used, in particular, in the study of heterogeneous media, geological surveys.

There are various devices for measuring the characteristics of the spectrum of signals, including spectral analyzer devices, where spectral characteristics are obtained as a result of the effect of the process being studied on a selective quadrupole, which is realized either by a set of band-pass filters, parallel or serially connected, or by means of dispersive delay lines,

either on a digital filter, or on a combination of digital and analog devices.

The same measurement technique is used in the well-known device, in which the signal recorded on a magnetic tape is supplied in electrical analog form to the input of a circuit containing variable band-pass filters, where spectral components are sequentially filtered and recorded on the indicator in the coordinates frequency-time-amplitude. The said device contains a serially connected playback unit for recording the analyzed signal, a narrowband tunable frequency filter, an amplifier, a spectrum recorder in the coordinates frequency - amplitude - time.

ABOUT

Yu

The disadvantage of this device is that the spectrograms obtained, although they allow detecting the presence of characteristic modes, make it possible to follow the development of the process under study in time, but have insufficient resolution for studying and estimating the parameters of the mode structure of the studied field, i.e. do not have sufficient information.

The aim of the invention is to increase the resolution and informativeness of the device by providing the possibility of a more accurate and unambiguous selection of the observed modes.

This goal is achieved by the fact that a device for spectral-temporal analysis of signals containing a playback unit for recording the signal being analyzed. voltage matching unit and serially connected narrowband tunable frequency filter, amplifier, spectrum recorder in the coordinates frequency - amplitude - time, connected by the second input to the first output of the read synchronization unit, the second output of which is the second input of the narrowband tunable frequency filter, and input - the output A pointer to the readout period, an analog-to-digital converter is inserted between the playback unit for recording the signal being analyzed and the voltage matching unit, interface unit, threshold selection unit, threshold level setter, decoder, delay time counter, signal duration counter, sample sample period setting unit, function execution unit of the type T -V (1 + + g) 2 - to 2 gDe to time delay of signal arrival from synchronization time, t is the current value of the signal duration, the write control unit, the memory unit and the digital-to-analog converter, the analog-digital converter input connected to the first output of the playback unit of the analyzed signal, and the output to the first input one interface unit, the second input of which is connected to the first output of the recording control unit connected by the second output to the first input of the memory unit, the second input of which is the first output of the interface unit, its second output connected to the first input of the threshold selection unit, second input which is connected to the output of the Threshold Level Adjuster, and the first - the third outputs of the threshold selection block are connected respectively to the first input of the time counter

delay, the first input of the recording control unit and the first input of the signal duration counter, the second input of which is the first output of the set period

sampling, connected by the second output to the second input of the recording control unit, the third input of which is connected to the output of the function execution block of the form T - /. (r + 2) 2-to 2- and 11 and the second inputs of which are connected to the output of the signal duration counter and the output of the time delay counter connected by the second input to the output of the decoder connected by its input to the second output of the playback unit of the recording of the analyzed signal, the output of the memory unit connected to the input of the voltage matching unit connected by its output to ervym input analog converter whose output is the second input of the narrowband tunable frequency filter and a second input of the digital to analog converter coupled to the third output of reading sync block, a fourth output is connected to the third input of the memory,

The function block of the type T -V (t0 + r) 2-to2 contains a series-connected adder, the first

quad, subtractor, root extraction block, buffer register and the second quad connected to the second input of the subtractor, with the first input of the adder connected to the output of the duration counter

signal, and the second input of the adder and the input of the second quadr are connected to the output of the delay time counter, the output of the buffer register is the third input of the recording control unit.

FIG. 1 shows the scheme of the proposed device; Fig. 2 is a block diagram of the execution of a function of the form T - V (t0-fr) 2-t02 per fig. 3 - the same, option.

The device (Fig. 1) contains a playback unit 1 for recording the analyzed signal, an analog-to-digital converter (ADC) 2, a conjugation unit 3, a threshold selection unit 4, a threshold level setting unit 5, a decoder 6. a delay counter 7,

block 8 of performing the function of the form T (to + V) 2-t02 block 9 of recording control, counter 10 of signal duration, unit 11 of sampling period, block 12 of memory, block 13 of charging, digital-to-analog converter (D / A) 14, narrow-band tunable frequency filter (PFC) 15, amplifier 16, recorder 17, read synchronization unit 18 and read period setting unit 19.

The first output of the playback unit 1 for recording the analyzed signal is connected via ADC 2 to the first input of the interface 3, the second input of which is connected to the first output of the recording control unit 9 connected by the second output to the first input of the memory 12, the second input of which is the first output an interface unit 3 connected by a second output to the first input of the threshold selection unit 4, the second input of which is connected to the threshold level sensor 5, and the first to the third output are connected respectively to the first inputs of the backward time counter 7 The control module 9 and the counter 10 of the signal duration, the second input of which is the first output of the setpoint generator 11 of the sampling period, connected to the second input of the recording control unit 9, the third input of which is connected to the output of the function 8 unit T e / (to + r) 2-to the first and second inputs of which are connected respectively to the outputs of the counter 10 of the signal duration and the counter 7 of the delay time connected by the second input to the output of the decoder 6 connected by its input to the second output block 1 playback recording of the analyzed signal. The memory unit 12 is connected by its output to series-connected voltage matching unit 13, D / A converter 14.UPF 15, amplifier 16 and recorder 17, and the third input of memory block 12 and the second inputs of DAC 14, UPF 15 and recorder 17 are connected to The outputs of the read synchronization unit 18 connected by its input to the output of the sensor 19 of the read period.

Unit 8 of performing the function of the type T ((FIG. 2) contains a series-connected adder 20, a first quad 21, a subtractor 22, a root extraction block 23, a buffer register 24 and a second quad 25 25 connected to the second input of the subtractor 22,: -S:

The playback unit 1 for recording the analyzed signal is designed to reproduce the signal under study and the reference sync pulse recorded on a magnetic medium (tape, tape, disk) and to obtain an electrical analog signal at the output. As this unit, a tape recorder can be used, from the first output of which the voltage corresponding to the signal is removed, and from the second to the reference clock.

A / D converter 2 converts the electrical voltage of signals from the first output of block 1 to the corresponding digital code.

The interface 3 is designed to match the parameters of the interface and 5 to ensure the interaction of the A / D converter with blocks 4 and 12, to receive and store data received from the A / D converter during one cycle of converting analog information, and output them to blocks 4 and 12.

0 Block 4 of the threshold selection is designed to select the useful signal and determine the moment of its arrival, which is ensured by comparing the code coming from block 3 with the one specified by

5 blocks 5 by the value of the threshold level. At the first excess and on. When this threshold is exceeded, block 4 outputs signals to counters 7 and 10 and block 9.

Over the threshold sensor level 5 provides

0 the possibility of setting a certain threshold level and converting this value to the corresponding code for issuing to block 4. The decoder 6 serves to highlight the reference clock, to generate a control pulse at the time of its arrival and to issue it to the counter 7.

Counter 7 of the delay time provides the determination of the time of arrival (delay) of the signal from the time of synchronization to

0 and its value is output to the ADC 2. This counter is triggered by a pulse coming from the decoder 6, and the stop is generated by a pulse from block 4 generated at the first time the signal arrives (above 5 nor the set threshold).

Block 8 of performing the function of the form T -V (t0 -f r) 2-to2 ensures that the specified operations are performed on the values of to and g, respectively, coming from

0 counters 7 and 10, and the output of the obtained value of T - modified time in block 9.

Block 8 contains (2) adder 20, which provides the operation

5 adding over the data to and g, coming from the counters 7 and 10, respectively, and issuing the result to the quad 21, which ensures the execution of the operation of squaring the value posting from the adder 20, and issuing the result to the subtractor 22, ensuring performing an arithmetic subtraction operation on the values (to + t) 2 and to2, coming from the quadrants 21 and 25, respectively, and issuing the result to the square root extraction unit 23, which ensures the execution of the specified operation on the value, n stepping of the subtractor 22, and output the result in the register 24, which serves for the intermediate storage of data coming from the unit 23 and outputting them to the unit 9, a second squarer 25, which provides fulfillment erecting operations in time squared magnitude values to. coming from counter 7, and issuing the result to the subtractor22.

The recording control block 9 is designed to organize and synchronize the operation of blocks 3, 4, 8, setpoint 11 and memory block 12 and receives from the unit 4 a start signal pulse, from block 8 — values of the modified time T, from setpoint 11 — the specified the sampling period, as well as the generation of control signals and issuing commands to block 3 to issue a signal code to block 12 and, last, commands to receive and ensure the recording of the signal code received from block 3 to a memory cell whose address is defined in the block 9 according to the value obtained from block 8 parameter T.

The counter 10 of the signal duration provides for determining the current values of time r, counted from the beginning of the arrival of the signal to its termination (or interruption), and the output of these values to block 8 in accordance with the sampling period specified in the generator 11.

This counter is started and stopped by the commands of block 4.

The unit 11 of the sampling period provides the ability to set a specific sampling period, the conversion of this value

the corresponding code and its issuance in the TO meter and block 9.

The memory block 12 is a memory device that, upon command from block 9, provides for receiving and storing signal codes from block 3 in memory cells in accordance with the addresses specified from block 9, as well as for receiving commands from block 18 for reading and issuing stored codes in the DAC 14 through block 13.

The voltage matching unit 13 provides the interface between the unit 12 and the DAC 14 and the matching of their electrical parameters.

D / A converter 14 is designed to convert incoming codes into voltages proportional to the values of the codes, and output them to the filter 15.

FPS 15 is designed to extract signals in the assigned bandwidth and provides a smooth change in the bandwidth when switching to a new read cycle. UPF is developed on the basis of an active filter with independent frequency control and quality factor, in it

it is possible to correct the dependence of the filter coefficient as a whole on its tuning frequency.

The matching amplifier 16 provides docking for the electrical parameters of the filter 15 and the recorder 17 and allows adjusting the value of the input power of the signal input to the recorder 17.

The recorder 17 is intended for recording and reproducing in a consistent form in the coordinates of frequency - time - amplitude of the results of spectral-time analysis of signals. The device uses a recorder with laconic recording (using an electric spark), which records the level of the signal received from amplifier 16, sweeps the pen (both ways) and draws electrothermal paper according to commands from block 18.

The read synchronization unit 8 organizes synchronous operation of units 12, central processing unit 14, filter 15, recorder 17 and provides control pulses in accordance with the cycle specified in unit 19 and issuing commands to unit 12 for reading and issuing information stored in it, in the DAC 14 - commands to start it, to filter 15 - commands to switch filters, to recorder 17 - commands to control the operation of the recorder.

The unit 19 of the readout period clears the possibility of setting the value of the readout cycle, as well as the values of the frequency range under study, the filter bandwidth, the reference tuning frequency, the conversion of these values into codes, and issuing them to block 18.

The device works as follows.

The signal recorded on the tape is reproduced in block 1. In this case, the reference clock pulse from one of the outputs of the tape recorder through the decoder 6 is fed to the input of counter 7 and does not start it tia will time out to time. and the signal converted into a digital code in the A / D converter 2, through the block 3 of the conjugation, is fed to the input of block 4 of the threshold selection, where it is compared with the threshold value specified from block 5. At the moment when this threshold is exceeded in block 4, a signal is generated which, arriving at the input of counter 7, stops it, arriving at the input of counter 10, starts it to count the duration of the signal t, and entering the input of block 9 of the recording control gives information about the need to prepare to receive and write the signal code to the memory (from block 3 to block 12).

In this case, the issuance of control signals from block 9 to block 3 and block 12 is carried out at a frequency specified by the setting device 11. With the same discreteness, the current values of the signal durability signal t are output from the counter 10 to the block 8. The delay time of the signal to is given to the input of block 8, where T - V + T is calculated) and the value of the modified time T is determined, which is fed to the input of block 9 of the recording control.

In block 9, the determined code of the value of T is brought into correspondence with the determined cell number, which is the address 15 cell for recording the signal code, point-to-point. block 3, in block 12 of memory.

Thus, the signal under study is transformed to a new type, recorded and stored in a new modified time scale in memory block 12. The next stage of operation of the device provides further signal processing. la read, filter and register. To perform these operations, from 25 master 19, a read period is set, the frequency range under study, the filter bandwidth, the reference frequency of its setting. These values are fed to the input of the synchronization unit 18 readings, where control commands are generated based on them, received in memory unit 12, D / A converter 14, UPF 15 and recorder 17. In accordance with these commands, produce in the recorder 17 Stretching paper at 35 a new pitch and setting the pen to its original position, and then sweeping it with burning along the time axis marks, the brightness of which is determined by the voltage value of the signal read from block 12, is converted 40 times a different electrical type in the DAC 14 after passing through From the voltage matching unit 13, and then filtered after the DAC 14 in the UPF 15 in a given frequency band and amplified in a matching amplifier 16. As a result, in the recorder 17 we obtain the spectrogram of the analyzed signal.

In addition to the one shown in FIG. 1 embodiment of the device, 50 other examples of its implementation are possible. So, when only the signal under investigation is recorded on a magnetic tape, and there is no sync pulse recording, the device eliminates the decoder 6 and the counter 7 of the delay time 55 and, accordingly, their connection with blocks 1,4 and 8, but additionally introduces a delay time setting for ensuring manual entry in block 8 of the value to.

It is also possible to build a device / when the signal, after the modification carried out by the inputted blocks 2-11, is recorded in the memory block 12, and then after converting their code into an analog form (block 13 and D / A converter 14) is fed to the input of block 1 for recording on the tape using a tape recorder and conducting subsequent analysis and recording.

It is also possible to implement another example of implementation of block 8 for performing a function of the form T - V (to + t) 2 2 (FIG. 3), where the transformed function is implemented,

T v (to + r) 2-to;

 vV + 2tor

using the quadr 26, which provides the execution of the operation of squaring the value of m, the multiplier 27, which performs the operation of multiplying the values of t, G0 and constant 2, the adder 28, which provides the addition of the values of the values coming from blocks 26 and 27, and outputting the result to the block 29 to extract the square root of this value and then output it to the buffer register 30. This option contains fewer blocks than the one shown in FIG. 2.

The device allows, as a result of spectral-temporal analysis of signals, to obtain spectrograms with a clearer and more unambiguous selection of modes and to determine their main characteristics, thereby ensuring an increase in the resolution and information content of the device compared to other known ones.

Claims (2)

Claim 1. Device for spectral-temporal analysis of signals, comprising a playback unit for recording an analyzed signal, a voltage matching unit and serially connected narrow-band tunable frequency filter, amplifier, spectrum recorder in the coordinates frequency-amplitude-time, connected by the second input to the first output of the unit read synchronization, the second output of which is the second input of a narrowband tunable frequency filter, and the input is the output of the reference period generator yvani, characterized in that, in order to increase the resolution and information content device by allowing more accurate and unambiguous separation of the observed events, it between the analyte signal recording and reproducing unit the voltage matching unit introduced an analog-to-digital converter, interface block, threshold selection block, threshold level sensor, decoder, delay mode counter, signal duration counter, sample time setting unit, T function type execution unit ( to + t) 2 - to 2 is the delay time of the signal arrival delay from the moment of synchronization, g is the current value of the signal duration, the recording control unit, the memory block and the digital-to-analog converter, with the analog-to-digital converter input connected to the first output m of the playback unit of the recording of the signal being analyzed, and the output - with the first input of the interface unit, the second input of which is connected to the first output of the recording control unit connected by the second output to the first input of the memory unit, the second input of which is the first output of the interface unit, the second its output connected to the first input of the threshold selection block, the second input of which is connected to the output of the threshold level sensor, and the first to the third outputs of the threshold selection block are connected respectively to the first input of the time counter delay, the first input of the recording control unit and the first input of the signal duration counter, the second input of which is the first output of the unit of the sample sample period connected by the second output to the second input of the recording control unit, the third the input of which is connected to the output of the unit performing the function of the form T Vjfto + Y) 2-to the first and second inputs of which are connected to the output of the counter the duration of the signal and the output of the time delay counter connected to the second input with the output of the decoder connected to the second output of the playback unit of the analyzed signal, the output of the memory unit is connected to the input of the voltage matching unit; its output is connected to the first input of a digital-to-analog converter, the output of which is the second input of a narrow-band tunable frequency filter, and a third output of the read synchronization unit, the fourth output of which is connected to the third memory input is connected to the second input of the digital-to-analog converter. 2. The device according to claim 1, characterized in that the unit performing the function of the form +. T.) 2 .tp 2, contains a series-connected adder, the first quad, subtractor, root extraction block, buffer register and the second quad connected to the second input of the subtractor, with the first input of the adder connected to the output of the duration counter The signal, and the second input of the adder and the input of the second quadrator are connected to the output of the Time Delay Counter, the output of the buffer register is the third input of the recording control unit. FIG. I 2 FIG. 3