SU748317A1 - Register of photocorrelation diagrams - Google Patents

Description

one

The invention relates to devices for recording acoustic logging information (TAK) in the form of continuous phase correlation diagrams and can be used in borehole seismic acoustic studies.

A device is known for recording AK information on a photo carrier in the form of a {0 continuous phase correlator of a regular diagram (PCD) using the variable density method l. The registry includes a luminance modulated electronic beam indicator (ELI), opti-. a system for projecting (OSB) brightness marks on a photo carrier, a photo carrier stretching mechanism synchronously with the movement of the borehole projectile on a scale of chart recording, a logging speed sensor, and an optical system optical system, which is controlled by the output signals of the speed sensor. When recording a PCD, there is an accumulation of several receivables through consecutive signals due to the superposition of superimposed images of brightness markers projected from the ELI screen on the photo carrier. For the influence of

changes in the multiplicity of accumulation on the optical density of the blackening of the photocarrier, which leads to a decrease in the clarity and reproduction of the recording and, as a result, in the accuracy, measurement, the initial signal of the sensor speed of the tape drive mechanism controls the aperture of the lens of the optical system 2,

A disadvantage of the device is the difficulty of providing high precision control of the diaphragm mechanism with a wide range of variation in the accumulation ratio, which leads to the occurrence of errors in measuring the kinematic parameters of elastic waves. The device requires the use of special regular diaphragms, which complicates the optical system of image projection. In addition, the presence of movable mechanical elements for transferring motion to the diaphragm, as well as repeated adjustments of the diaphragm mechanism in equipment designed for operation in field conditions, leads in addition to a decrease in measurement accuracy and reliability. ..., ---: -.,. . -GL: - .. -... G.-. -, -. -: --.... : - -. -. ., i. .. The closest to the forecasted technical solution is the PCD recording device, which contains a modulated by brightness ELI, OSB performance MevoK, a mechanism for stretching the photo carrier synchronously with the movement of the borehole projectile on the scale of recording diagrams, the shaper of the PCD signal of the standard duration and amplitudes {logging logging speed sensor, FKD recording signal accumulator and amplitude adjustment of the highlight. Such recorders are equipped for recording PCDs of domestic stations such as LAC, Zvuk AKKN, In these devices to obtain qualitative diagrams when the accumulation ratio varies depending on the speed of the photocarrier regulating the amplitude of the backlight and the current of the electron-beam tube (EDT), respectively, calibrate the scale of adjustments . With K-fold superpositions of the exposures а, which are created by the photocarrier at every glare, the total exposure Э is S S3.-K3. t - i By choosing the appropriate position of the illumination and luminance adjustments of the beam, the Э .-. (K1 (, k.) turns out to be real, that is, the exposure becomes independent of the accumulation ratio. Here Ed is the exposure value, providing the optical density required for qualitative interpretation of PCDs on a photocarrier. Calibration of the scales of CRT brightness regulators is determined by the modulation characteristic of the tube, t, i.e., depending on the brightness of the Venom screen, on the setting voltage of the cathode voltage, g The TG coefficient characterizing the non-linearity of the modulation characteristics, in most cases, 5, The drawback of the device is a decrease in the measurement accuracy with large variations in the multiplicity of accumulation associated with the type of modulation characteristic CRT from the instance The pv have a wide variation in modulation characteristics and change with time. Moreover, CRTs do not qualify according to the f (U) dependences. This makes the calibration of the control dials very inaccurate. The non-linearity of the modulation characteristic of the HWP leads to an increase in / out-time of the installation error of the required tube brightness caused by the load on the voltage applied to the modulator: Ms - .V-A1J, I. calibration of the scale, the accuracy of the speed sensor and, and so, d. The aim of the invention is to improve the accuracy of measuring the kinematic parameters of acoustic pulses and the reliability of the recorder. The goal is achieved by connecting the output of the logging speed sensor to the speed-to-frequency converter, the converter output is connected to one of the cxeNW comparison inputs through a one-time luminance simulation simulator, a reference spot luminance receiver is installed in front of the indicator screen, the output of which is connected to another input of the comparison circuit, and its output through the unit for forming a reference spot of variable luminance is connected to the input of the adder. FIG. 1 is a block diagram of a phase correlation recorder; Fig. 2 shows the modulation characteristic of a CRT and the form of the applied modulating voltage; Fig. 3 shows an example of the implementation of a unit for forming a reference spot of variable luminance; FIG. 4 shows graphs explaining the operation of the unit for forming a reference spot of variable luminance% ia of FIG. 5, graphs explaining the operation of the PCF recorder. The PCD recorder contains the modulus of brightness by the electron-beam in-. Dicator 1, logging speed 2 to accumulation ratio 2, unit of forming a reference spot of variable brightness, photodetector 4, block of simulating a single flash of a CRT, comparison circuit B, cyMf-iaTOp 7, sensor 8. logging speed. Electron beam indicator 1 is designed to display incoming information in the form of luminance modulated tags. The indicator modulator is connected to the output of the adder 7. The information from the ELI screen is projected by the optical system onto the photo carrier and is recorded as continuous lines of phase correlation. Inverter 2 connected to the output of the logging speed sensor is made as an accumulation factor sensor (DTC) and produces a signal proportional to the multiplicity of the accumulation of signals on the photocarrier. The sensor is implemented in the form of a photoelectric converter (photoelectric converter) mounted on the top of the tape mechanism.

W1x1rez width (/ on the coding disk F5G1 is equal to the size of the port and on the photo carrier of the CRT benchmark. The size of the 1st light on the photocarrier section (along the long side of the logging diagram) can be set the photocarrier surface. The slit length is chosen equal to the image size of the beam spread on the CRT screen. The disk is illuminated by a light beam from the strobotrons, which commute with the frequency of starting the radiators th projectile. In this implementation, DTC output transducer 2 represents a sequence of pulses, whose number is equal to the measured ratio.

Unit 3 (BF) is intended to form an illumination in the form of a spot of the reference variable capacitance 1 on the CRT screen. A spot is formed in a time interval that is a priori free from the appearance of a useful signal. The unit is implemented as a step-1Pr (GOS) generator for shifting the modulation characteristics of a CRT with a pulse of a standardized duration and amplitude applied to each stage of the illumination. The amplitude of the backlight signal is chosen equal to the amplitude of the pulses, feeding aeNbix to the recorder input for recording the PCD (Fig. 1).

FIG. Figure 2 shows the waveform of the output of the BF block and the corresponding change in time of the luminance of the reference spot. The GOS may be completed, for example, on the basis of the well-known cxeNtJ, built on the principle of converting the result of a sequential counting of pulses into voltage using a digital-analog converter.

An example implementation of a variable brightness driver is shown in FIG. 3, where 9 is a step voltage generator, 10 is a differentiating circuit (DC), 11 is a standardizer of pulses in duration and amplitude (SI), 12 is an adder.

At the command, the Beginning of the GOS counting begins the formation of stepped voltage. The voltage drops of each step are differentiated by the DC chain and launch the standardizer 11, implemented as a waiting pulse generator. The generated pulses are then summed in the adder 12 with the signal of the GOS and are fed to the input of the adder 7. (Fig. D; To control the rise of the voltage of the GOS, the control commands serve

and reset.

FIG. 4 shows the graphs explaining the sequence listed: no conversions: a - signals from command part1 of the count, eb - impulses generated in hsn converted into step voltage, g - voltage at output of hcn, g - signal from the command end of count, g - signal comandy Reset, e - impulses at the output of the DC, w - impulses at the SR output;

3 pulses at the output of the adder-12.

The photodetector 4 is installed in front of the screen of the CRT. In the image area of the reference mark of variable brightness

0 and converts brightness to a voltage proportional to it. As a photodetector a semiconductor photocell can be used, for example, a photodiode. It is known that light

5V characteristic of such a photodetector is linear with high accuracy in a wide range of input effects. Therefore, the relationship between the output voltage of the photodetector and the variable

0 by the intensity of this; an alon spot on the screen of a cathode ray tube, I, is a relationship:

five

where K fp - the proportionality coefficient. The output of the photodetector is connected to one of the inputs cxeNbi of comparison b (fi, 1).

The unit 5 for simulating (NI) the brightness of a single CRT light is intended to form a voltage imitating the amplitude of the signal at the output of a photoreceiver identical to that of the OP 4, at a capacitance equal to Яо / К, where Yar is the spot that corresponds to the exposure of a single exposure of a photocarrier is equal to Eo. The block is realized as a divider of the reference voltage, formed by digital control of resistance (NOC) and low resistance, in comparison with NOC, load resistance. The amplitude of the source of the reference voltage is chosen equal to the voltage of the output of the photodetector 4 at brightness

5 of the reference spot, equal to Yao, i.e.

When the voltage at the output of the unit

0 simulation equals:

  r et-M

The output of the simulation block is connected to the second input of cxeNEJ comparison 6.

five

Circuit 6 is designed to compare output voltages.

4 and block 5 and form-1 and signal

commands End of account

(Fig. 3) i

at the moment of their equality. This happens when the brightness becomes

Claims (1)

60 equals Yao / K. The parameters of modern photoreceivers are such that the measured voltage of the reference voltage (Kfp Yao) may be insufficient for the stable operation of the practically implemented unit 5. Therefore, with an increase, by M times for the invariance of the conditions of operation of comparison 6 t is a scale amplifier with a gain of M, 7 is designed for adding signals to the recording of PCD, standardized in duration and amplitude and for example produced by block 5, It can be implemented as an active or passive circuit s to a common load. The output of the adder is connected to a CRT brightness module. The work of the registrar is as follows. In the initial state, the recording signals of the PCD, standardized in duration and amplitude, are input to the recorder input. The voltage at the output of the single-light simulation unit is equal to (proportional to) the accumulation ratio K, measured in the previous 1-cy of the DTC: UjH. The bias voltage generated by block 3 is summed up from the PCD recording signal. adder 7, a reference brightness level is formed on the non-CRT screen, at which the voltage of the voltage is equal to "Therefore, PET-i Poison / K. The same brightness on the screen of the CRT is created by the recording signals of the PCD:. The total exposure reported to the photocarrier by the brightness mark at K., - - multiple accumulation on the photo layer, is 3 - S3, - k. i-H and does not depend on the multiplicity. After decoding the next DTC, the voltage on the output of block 5 is set. When the Reset command (Fig. 3) is generated, for example, the DTCs after declaring the measured multiplicity K, the offset value of the bias voltage on the CT blocker is reset. Then, the Start counting command (Fig. 3) is formed, according to which the bias voltage on the CRT modulator and the corresponding intensity of the reference point begin to increase. Correspondingly, the voltage at the output of the Inika 4 photon increases. When the voltages are equal for you at compihex comparison 6, the command for the end of counting signal is generated (Fig. To finish the further increase of the step bias voltage 3. As the amplitude of the FCD recording signals is chosen equal to the pulses under the light of a CRT formed in block 3, the marks they make on the ELI screen have the same brightness: Yase. 1+ 1 + -1 At the same time, the total exposure E, ... e „1 .., i.e. . remains constant when changing the multiplicity. The operation of the PCD recorder is explained in Asphors in Fig. 5: a and b - signals of the Reset and Start of count commands, c - voltage at the output of block 5 with i and i + 1 - DTCs operation cycles, g signals of PCD recording, d - voltage at the output of adder 7, e is the change in the luminance of the reference spot and the PCD recording signals, w, the signals of the command End of Count, Further operation of the recorder is repeated cyclically with each new decoding of the information from the output of the logging speed sensor 8 (see, Fig. 1) Acoustic logging diagrams of modulation in brightness lektronnoluchevoy indicator coupled to the output of the adder, the recording signal generator logging diagramky standard duration and amplitude, tape transport mechanism of photocarriers. synchronously with the movement of the downhole si-dar on the scale of recording diagrams, the optical system of projecting the image from the screen of the indicator onto the photo carrier and the logging speed sensor is different. In order to increase the accuracy of measuring the kinematic parameters of acoustic pulses and the reliability of the recorder, a speed converter has been introduced in the multiplicity of signal accumulation, a unit for simulating the brightness of a single glare of the display screen, a comparison circuit, a photo detector of the brightness of the reference spot, and a unit forming a reference spot of variable luminance, while the output of the logging speed sensor is connected to the speed converter in the accumulation ratio of signals, the converter output through the unit and A single-glare brightness test is connected to one of the inputs of the comparison circuit, in front of the indicator screen a photosensor of the brightness is installed, the output of which is connected to another input of the comparator cxeNbi, and its output through a variable brightness forming unit with the input of the adder. Sources of information taken into account in the examination of li U.S. Patent W 3093810, cl. 340-18, 1963, 2, Perelman A, A. et al. Some of the requirements that are unique to AK equipment of the LAC type. Geophysical equipment, Nedra, L., no. 32, 1967, p. 112. 3. Guidelines for AK (for the station LAC - 3) VNIIGeofizika, Moscow, 1974 (prototype). 111 pl 748317 Ill Jljl