SU611165A1 - Apparatus for processing vibration recordings in predetermined frequency range - Google Patents

Description

The aim of the invention is to expand the functional capabilities of the device and increase its reliability.

The goal is achieved by introducing into the proposed device two waiting multivibrators, a smoothing filter and setting switches for the binary code; the inputs of the waiting multivibrators are connected via diodes and binary code switches to the outputs of the block determining the instantaneous frequency of the reference signal, and the outputs are loaded on a relay connected to the output of the seismic receiver through the smoothing filter.

In the proposed device, in the process of reproducing the signals recorded in the field, a continuous measurement of the instantaneous frequency of the reference signal is performed. At the moment of reaching the specified frequency, the waiting multivibrator is triggered, which turns on the circuit passing the seismic receiver signal to the correlating device

(analogue of the high-pass filter) or turning it off {low-pass filter). the multivibrator generates pulses as long as the frequency of the reference signal is above the specified value. Since the duration of the pulse of the waiting multivibrator is almost equal to the time interval used to measure the instantaneous frequency of the reference signal, the signal from the geophone will be passed (or turned off) to the correlating headphone as long as the frequency of the reference signal is above the specified value. If, during the excitation of elastic vibrations, several cortex cycles are generated, then. the signal transmission circuit will work only during those periods when the instantaneous frequency is higher than the specified value.

The drawing shows a block diagram of the proposed device for processing vibration records in a given frequency range.

In the proposed device, the reproducing node 1 is connected to the inputs of the amplifier 2 of the geophone signal, the imaging unit 3 a reference signal (the vibrator signal) and the imaging unit 4 clock pulses. The outputs of the elements 2, 3 and 4 are connected to the calculating unit 5, in addition, the outputs of the elements 3 and 4 are connected to the input of the meter 6 of the instantaneous frequency of the reference signal. Outputs of the meter 6 through toggle switches G | - Tg, which serve to set in binary form the values of the boundary frequencies of the selected range of vibrations, and the diodes are connected to the input of the waiting multivibrators L / 1 and M-2. Waiting multivibrators through smoothing cells RiCi and RjQ are loaded on the executive elements PI and Pr (relay or electronic keys). PI and mute or open the output of amplifier 2.

. The device works as follows.

After reproducing the amplification and forming the reference signal and the clock pulses, the instantaneous frequency-1, l reference signal is input to the meter 6 to determine.

The principle of operation of meter 6 is to count the number of pulses of the reference signal during a certain constant time interval LH, which is determined by counting a predetermined number of clock pulses.

Tumblers G | - T sets the lower limit of the frequency range of vibrations in the binary code. Tumblers (, - upper limit.

At the moment of coincidence of the instantaneous frequency of the reference signal with a predetermined value, a pulse appears that triggers the waiting multivibrator (MI and Mj). This pulse is repeated every time the frequency of the reference signal is equal to or higher than the value set on the Toggle Switches.

The repetition rate is equal to the duration of the AG time interval, during which the instantaneous shchtot of the reference signal is determined. The duration of the impulse of the railway multivibrator is selected by several exchanges; AT, after smoothing the RC cell, the voltage from the outputs of the multivibrators controls the operation of the relay P W P-2.

Relay PI opens the output of a seismic signal amplifier, when the frequency of the reference signal becomes equal to the specified lower value. Relay / 2 - closes the same output with a switch equal to or higher than the specified upper limit.

Thus, in contrast to the known device, in the proposed apparatus, the frequency of the reference signal is continuously monitored. As soon as it falls below the set point, the relay returns to its original position. This allows one to work with signals consisting of several short actions, successively excited in one or neighboring points.

Since the boundary frequencies of the vibration range are set by setting the corresponding binary code to the toggle switches (G1-G4), the frequency change step can be selected by any means. With 4 toggle switches - after 4 Hz, with 5 - through 2 Hz. This greatly simplifies the design of the equipment in comparison with the known device and expands its capabilities.

It should also be noted that sampling only a part of the recorded in the record field significantly speeds up subsequent processing on digital machines as a result of a reduction in the amount of information received by the computer. At present, the long duration of the vibromiddle recordings is one of the main reasons that impede the implementation of digital processing in vibrational seismic surveys.

Claims (2)

1. Certificate of author No. 269504, cl. G 01 V 1/14, 1967. 2. Certificate of author No. 283614, cl. G 01 V 1/28, 1969. R -and TO d. . m Mg  Kiff 1H tiHi f, -1l l 2