RU2592752C2 - Seismograph - Google Patents

Abstract

FIELD: geology.

SUBSTANCE: invention relates to devices for recording seismic waves. Device comprises tight housing (1), inside which there are following elements: inertial mass (3) with suspension system (2), mirror reflecting surface (4), magnetic damping system (5), reference signal generator (12), calibrating coil (13), laser micrometer (20). Device also includes unit (9) for generating output signal, time unit (10), control device (11), unit (14) for interface with client part. Unit (9) for generating output signal comprises a unit for final signal processing and a unit for determining position of inertial mass, which includes a read-only memory, a signal time synchronisation unit and a range calculating unit.

EFFECT: technical result is improved accuracy of detecting seismic vibrations, higher efficiency of obtaining and processing seismic data.

1 cl, 2 dwg

Description

The invention relates to geophysical instrumentation, namely to seismometry, and can be used in seismic exploration of mineral deposits, in seismic groups for recording earthquakes, underground nuclear and chemical explosions, as well as in seismic security systems.

A known seismograph containing a sealed enclosure, an inertial mass with a suspension system suspended from the housing, a magnetic damping system attached to the inertial mass, a mirror reflective surface mounted on the inertial mass, a laser micrometer connected to the output device and mounted on the housing so that it the longitudinal axis is directed to the reflecting surface perpendicular to it, and the output device and the time unit are connected to a read-only memory (ROM). [one]

The disadvantages of the analogue are: low accuracy of recording seismic vibrations as a result of the inability to dynamically control changes in the zero position of the inertial mass (zero drift) as a result of external influences (changes in temperature, humidity, pressure) and structural changes consisting in aging of structural elements; low efficiency of receiving and processing seismic data.

Closest to the proposed invention is a seismograph containing a sealed enclosure, an inertial mass with a suspension system suspended from the housing, a magnetic damping system attached to the inertial mass, a mirror reflective surface mounted on the inertial mass, a laser micrometer connected to the output device and mounted on case so that its longitudinal axis is directed to the reflecting surface perpendicular to it, and the output device and the time unit are connected to a permanent storage device The device is equipped with a unit for monitoring the zero position of the inertial mass of the seismograph; moreover, the output of the laser micrometer is connected to its input and one of the inputs of the output device, the output of the unit for monitoring the zero position is connected to the other input of the output device, and the output device and the time unit are connected to read-only memory. [2]

The disadvantage of the prototype is also the low accuracy of registration of seismic oscillations as a result of a sufficiently large methodological error in determining the distance to the zero position of the inertial mass in the control unit for the zero position of the inertial mass and the low efficiency of obtaining and processing seismic data.

The aim of the invention is to increase the accuracy of registration of seismic vibrations and increase the efficiency of obtaining and processing seismic data.

This goal is achieved by the fact that the known seismograph containing a sealed enclosure, an inertial mass with a suspension system suspended from a sealed enclosure, a magnetic damping system attached to an inertial mass, a mirror reflective surface mounted on an inertial mass, a laser micrometer mounted on the housing so that its longitudinal axis is directed to the reflecting surface perpendicular to it, a time unit and a read-only memory, further comprising an output generating unit Igna comprising block end signal processing unit determining the position of the inertial mass, comprising serially connected a ROM block timing signals and range calculating unit; the output of the laser micrometer is connected to the input of the time synchronization unit and the input of the final signal processing unit, the time unit and the range determination unit are connected to other information inputs, the outputs of the control device are connected to the control input of the unit for determining the position of the inertial mass and the control input of the reference signal generator, the outputs of which connected to the inputs of the calibration coil, and the output of the final signal processing unit is connected to the input of the interface unit with the client part.

Figure 1 presents the structural diagram of a vertical seismograph. Figure 2 presents the structural diagram of the block forming the output signal, where:

1. sealed enclosure

2. suspension system

3. inertial mass

4. mirror reflective surface

5. magnetic damping system

6. ferrite core

7. damping coil

8. controllable resistor

9. output signal conditioning unit

10. time block

11. control device

12. reference signal generator

13. calibration coil

14. client interface unit

15. signal processing unit

16. unit for determining the position of the inertial mass

17. read only memory

18. signal timing block

19. range calculation unit

20. laser micrometer.

A seismograph consists of: a sealed enclosure 1; suspension systems 2 of inertial mass 3, on which a specular reflecting surface 4 is rigidly mounted; a magnetic damping system 5, comprising a ferrite rod 6, which is attached to the inertial mass 3, and a damping coil 7, closed to a controlled resistor 8 and attached to a sealed enclosure 1; a laser micrometer 20, mounted on a sealed housing 1 so that its longitudinal axis is directed to the mirror reflecting surface 4 perpendicular to it; output signal generating unit 9.

The output signal generating unit 9 includes a final signal processing unit 15 and an inertial mass position determining unit 16 containing serially connected ROMs 17, a signal timing block 18 and a range calculating unit 19, the output of the laser micrometer 20 is connected to the input of the signal timing block 18 and the input block final signal processing 15; to the other information inputs of the final signal processing unit 15, a time unit 10 and a range determination unit 19 are connected. The outputs of the control device 11 are connected to the control input of the unit for determining the position of the inertial mass 16 and the control input of the reference signal generator 12, the outputs of which are connected to the calibration coil 13 attached to the sealed housing 1 and located around the ferrite rod 6 of the magnetic damping system 5. The output of the final signal processing unit 15 is connected to the input of the interface unit with ent part 14.

The device operates as follows: the energy of seismic vibrations drives the sealed housing 1 of the seismograph relative to the inertial mass 3; a laser micrometer 20 with a given sampling frequency Δt emits a laser beam that is reflected from the mirror surface 4 and returns. Laser micrometer 20 according to the results of beam reflection determines the distance to the current position of the inertial mass according to the formula Y (i) = n (i) + D, where n (i) is the oscillation of the inertial mass 3 relative to the sealed housing 1, D is the distance from the laser micrometer 20 to the zero position of the inertial mass 3. The output signal of the laser micrometer 20 enters the block for determining the position of the inertial mass 16 and the final signal processing unit 15, in which the output signal of the range calculation unit 19 D is subtracted from the output signal of the laser micrometer 20 Y (i) the distance from the laser micrometer 20 to the zero position of the inertial mass 3, and the signal reports are linked to the time stamps T coming from the time unit 10. The output signal of the final signal processing unit 15 is input to the interface unit with the client part 14 in which it is transmitted to client means of registration, transfer, express analysis and other types of terminal processing.

To calculate D, the control device 11 generates a control signal supplied to the reference signal generator 12, which supplies a current I (t) = B · sin (ω · t) to the calibration coil 13, while the ferrite rod 6 is rigidly fixed to the inertial mass 3 , is brought into vibrational motion y (t) = A · sin (ω · t). The other output of the control device 11, connected to the control input of the unit for determining the position of the inertial mass 16, starts the calculation process D.

, где $$\omega =\frac{2\pi }{\Delta t}$$

, n(i) - отчеты сейсмического сигнала, K - количество отсчетов дальностей; до прихода второго управляющего сигнала от устройства управления 11 одновременно управляющий сигнал со второго выхода отключает генератор эталонного сигнала 12.In the block of temporary synchronization of signals 18, reports of ranges to the current position of the inertial mass 3 are accumulated - Y (i) = A · sin (ω · i + φ) + n (i) + D, $$i=\overline{\mathrm{one,}K}$$

where $$\omega =\frac{2\pi }{\Delta t}$$

, n (i) —seismic signal reports, K — number of range samples; before the second control signal arrives from the control device 11, the control signal from the second output simultaneously disables the reference signal generator 12.

с частотой и амплитудой колебания равной заданному колебательному движению ферритового стержня 6, при этом $$K-k>\frac{1}{\Delta t}$$

.In the ROM 17 stored reference signal S (j) = A · sin (ω · j), $$j=\overline{\mathrm{one,}k}$$

with a frequency and amplitude equal to a given oscillatory motion of the ferrite rod 6, while $$K-k>\frac{\mathrm{one}}{\Delta t}$$

.

, $$\tau =\overline{\mathrm{0,}K-k}$$

, при максимуме функции $$\max \left[{\left(D*S\right)}_{\tau }\right]|{}_{s=\tau }$$

находится синхронизирующая переменная s. Сигналы синхронизируются, уравниваются по длительностиIn the block of temporary synchronization of signals 18, a temporary synchronization of the range signal stored in it and the reference signal is performed. For this, the values of the cross-correlation function of the signals are calculated $${\left(Y*S\right)}_{\tau }={\displaystyle \sum _{j=\mathrm{one}}^{k}Y\left(j+\tau \right)\cdot S\left(j\right)}$$

, $$\tau =\overline{0K-k}$$

, with maximum function $$\max \left[{\left(D*S\right)}_{\tau }\right]|{}_{s=\tau }$$

the synchronization variable s is found. Signals are synchronized, equalized in duration

and served in the unit for calculating the range 19 D between the laser micrometer 20 and the mirror reflective surface 4.

:The range calculation unit 19 determines the signal-to-noise ratio (SNR) in dB between the range signal Y (j) and the reference signal S (j) shifted with the set step d of the variable d∈ [min (D (s + j)), max (D (s + j))], $$j=\overline{\mathrm{one,}n}$$

:

, $$j=\overline{\mathrm{1,}k}$$

. При максимуме ОСШ $$\max \left[SNR\left(d\right)\right]|{}_{D=d}$$

находится D - вычисленная дальность от лазерного микрометра 8 до нулевого положения инерционной массы 3, которая в последующем в блоке конечной обработки сигнала 15 вычитается из сигнала дальностей до текущего положения инерционной массы 3 Y(i)=n(i)+D-D. $$SNR\left(d\right)=10{\log }_{10}\left(\frac{{\displaystyle \sum _{j}Y{\left(s+j\right)}^2}}{{\displaystyle \sum _j{\left[S\left(j\right)+d\right]}^2}}\right)$$

, $$j=\overline{\mathrm{one,}k}$$

. At maximum SNR $$\max \left[SNR\left(d\right)\right]|{}_{D=d}$$

D is the calculated distance from the laser micrometer 8 to the zero position of the inertial mass 3, which is subsequently subtracted from the range signal to the current position of the inertial mass 3 in the final signal processing unit 15 Y (i) = n (i) + DD.

равен колебанию инерционной массы 3 относительно герметичного корпуса 1 Y(T)=n(T).The output signal Y (T) of the final processing unit of the signal 15 when

equal to the fluctuation of the inertial mass 3 relative to the sealed housing 1 Y (T) = n (T).

Useful technical effects of using the device is to increase the accuracy of recording the fluctuations of the inertial mass 3, by improving the methodology for determining the zero position of the inertial mass 3, implemented in the block for determining the position of the inertial mass 16, as well as increasing the efficiency of processing the seismic signal by using the interface unit with the client part 14 after which the seismic signal is transmitted to the client means of registration, transmission, express analysis and other types of terminals Noah processing.

Used Books

1. RF patent for utility model 101848, Seismograph, IPC G01V 1/00, 2010, authors: Krivonogov AN and others (analog).

2. RF patent for utility model 107866, Seismograph, IPC G01V 1/00, 2011, authors: Krivonogov AN and others (prototype).

Claims (1)

A seismograph comprising a sealed enclosure, an inertial mass with a suspension system suspended from the sealed enclosure, a magnetic damping system attached to the inertial mass, a mirror reflective surface mounted on the inertial mass, a laser micrometer mounted on the housing so that its longitudinal axis is directed to the reflective the surface perpendicular to it, a time unit and a read-only memory device, characterized in that an output signal generating unit is additionally introduced, comprising a finite unit signal processing and the unit for determining the position of the inertial mass, which includes serially connected read-only memory, a time synchronization unit for signals, and a range calculation unit connected to the final signal processing unit, the output of the laser micrometer being connected to the input of the time synchronization unit and the input of the final processing unit the signal to which the time unit and the range determination unit are connected, the outputs of the control device are connected to the control input of the field determination unit zheniya inertial mass and the control input of the reference signal generator, which outputs are connected to inputs of a calibration coil, and the input interface block with the client part is connected to the output end of the signal processing unit.

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