Seismometer with high sensitivity, broadband and all-dip

Patent metadata

Field	Value
Publication number	US-11953635-B2
Application number	US-202318352240-A
Country	US
Kind code	B2
Filing date	Jul 13, 2023
Priority date	Jul 19, 2022
Publication date	Apr 9, 2024
Grant date	Apr 9, 2024

Abstract

A seismometer with high sensitivity, broadband and all-dip is provided, The which relates to the technical field of seismometer, including a first force feedback module, an insulator, a top cover, a terminal post, an upper leaf spring, a mass block, a casing, a sealing ring, an insulation gasket, a guide spring, a wire frame, a magnetic shoe, a compensation ring, a lower leaf spring, a bottom cover, a second force feedback module and a third force feedback module. It provides the broadband seismometer technology based on dynamic force balance feedback and the all-dip broadband seismometer technology based on dip angle perception, which breaks through the limitations of conventional seismometers in sensitivity, frequency band, and dip angle, and truly realizes a seismometer with high sensitivity, broadband, and all-dip.

First claim

What is claimed is:

1. A seismometer with high sensitivity, broadband and all-dip, comprising a first force feedback module ( 1 ), an insulator ( 2 ), a top cover ( 3 ), a terminal post ( 4 ), an upper leaf spring ( 5 ), a mass block ( 6 ), a casing ( 7 ), a sealing ring ( 8 ), an insulation gasket ( 9 ), a guide spring ( 10 ), a wire frame ( 11 ), a magnetic shoe ( 12 ), a compensation ring ( 13 ), a lower leaf spring ( 14 ), a bottom cover ( 15 ), a second force feedback module ( 16 ) and a third force feedback module ( 17 );
wherein the first force feedback module ( 1 ) is fixed on the magnetic shoe ( 12 ), the second force feedback module ( 16 ) and the third force feedback module ( 17 ) are both fixed in a middle of the wire frame ( 11 ), the top cover ( 3 ) is tightly pressed on the upper leaf spring ( 5 ) and the magnetic shoe ( 12 ), the magnetic shoe ( 12 ) is tightly pressed on the lower leaf spring ( 14 ) and the bottom cover ( 15 ), the terminal post ( 4 ) is elastically connected to the guide spring ( 10 ), the insulator ( 2 ) is connected to the casing ( 7 ), the mass block ( 6 ) is respectively adjacent to the magnetic shoe ( 12 ) and the compensation ring ( 13 ) and is located in a middle of the seismometer, the sealing ring ( 8 ) is adjacent to the upper leaf spring ( 5 ) and is located at a bottom of the seismometer, the insulation gasket ( 9 ) is located at a top of the seismometer, and the compensation ring ( 13 ) is adjacent to the magnetic shoe ( 12 ).

2. The seismometer with high sensitivity, broadband and all-dip according to claim 1 , wherein each of the first force feedback module ( 1 ), the second force feedback module ( 16 ) and the third force feedback module ( 17 ) comprises a first control sub module and a second control sub module; the first control sub module comprises a coil and a PID feedback circuit; the second control sub module comprises an application layer, an algorithm layer connected to the application layer, and a sensing layer connected to the algorithm layer;
the application layer is configured to obtain dynamic orientation and obtain perception of low-frequency signals based on the dynamic orientation;
the algorithm layer is configured to calculate feedback parameters of the seismometer based on the first force feedback module ( 1 ) by using a broadband seismometer method based on dynamic force balance feedback, and to cancel interference of gravity components based on the first force feedback module ( 1 ), the second force feedback module ( 16 ) and the third force feedback module ( 17 ) by using an all-dip broadband seismometer method based on dip angle perception, and feedback angle and attitude information of current seismometer;
the sensing layer is configured to influence a motion of the mass block ( 6 ) based on a generated feedback force to obtain a sensing perception result; and
the PID feedback circuit is configured to generate feedback current according to the feedback parameters of the seismometer, and generate feedback force based on the coil.

3. The seismometer with high sensitivity, broadband and all-dip according to claim 2 , wherein the application layer comprises a memory and a collector connected with the memory;
the algorithm layer comprises a feedback calculation unit connected to the collector, a D/A converter and a D/A converter respectively connected to the feedback calculation unit; and
the sensing layer comprises a coil driver connected to the D/A converter, a feedback coil connected to the coil driver, a dynamic coil sensor connected to the feedback coil, and a preamplifier connected to the dynamic coil sensor; and the preamplifier is connected to the A/D converter.

4. The seismometer with high sensitivity, broadband and all-dip according to claim 3 , wherein the feedback calculation unit comprises:
a parameter estimator, configured to calculate frequency characteristic response of a collected signal and an excitation signal, extract a difference response curve;
a controller parameter calculation sub unit, configured to dynamically adjust calibration parameters of the current seismometer according to a calculated frequency characteristic response curve; and
a controller, configured to adjust acquisition frequency according to controller parameters to achieve real-time dynamic calibration of the seismometer.

5. The seismometer with high sensitivity, broadband and all-dip according to claim 4 , wherein a calculation process of the feedback parameters of the seismometer is as follows:
A1. the coil driver is used to receive analog signals from the D/A converter, and the feedback coil is controlled through the analog signals to excite a specific frequency vibration signal;
A2. the vibration signal is transmitted to the feedback calculation unit through the dynamic coil sensor, the preamplifier, and the A/D converter in sequence;
A3. the frequency characteristic response of the collected signal and the excited vibration signal is calculated by the feedback calculation unit to extract the difference response curve;
A4. according to the difference response curve, parameters g′ p g′ i g′ p of the current seismometer are calculated by using a frequency calibration equation;
A5. based on the parameters g′ p g′ i g′ p , the feedback coil is reused as a signal generator and obtain a frequency band of current signal;
A6. according to a difference between a current signal frequency band and a standard frequency band, a frequency band drift value of the current seismometer is obtained;
A7. based on the frequency band drift value, the feedback parameters g p , g i and g d of the seismometer are obtained through inverse inference based on interpolation results.

6. The seismometer with high sensitivity, broadband and all-dip according to claim 5 , wherein an expression of the difference response curve is as follows:
F′=F o −F i
wherein, F′ represents the difference response curve, F o represents a frequency characteristic spectrum of the collected signal, and F o represents a frequency characteristic spectrum of the vibration excitation signal.

7. The seismometer with high sensitivity, broadband and all-dip according to claim 6 , wherein an expression of the frequency calibration equation is as follows:

{

g
p

=

-

γδ
⁡
(
t
)

⁢

F
′

(
t
)

1
+

a
1

g
i

=

Assignees

• Inst Geology & Geophysics Cas

Inventors

• Wang Yibo
• Xue Qingfeng
• Zheng Yikang

Classifications

• G01V1/18 Primary

  Receiving elements, e.g. seismometer, geophone {or torque detectors, for localised single point measurements} · CPC title

• G01V1/003

  Seismic data acquisition in general, e.g. survey design (G01V1/3808, G01V1/42 take precedence) · CPC title

• G01V1/164

  Circuits therefore · CPC title

• G01V1/202

  Connectors, e.g. for force, signal or power · CPC title

• G01V1/307

  for determining seismic attributes, e.g. amplitude, instantaneous phase or frequency, reflection strength or polarity · CPC title