Seismic geophone and measuring method thereof

Abstract

The invention belongs to the technical field of seismic exploration, and particularly discloses a geophone and a measurement method thereof. The geophone comprises an oscillator unit, an upper cover plate and a measuring unit, wherein the upper cover plate and the measuring unit are arranged right above the oscillator unit in parallel; a first capacitor plate array is deposited on the lower surface of the upper cover plate through metal deposition, and a second capacitor plate array and a metal coil are deposited on the upper surface of an oscillator of the oscillator unit through metal deposition; the vibrator unit is arranged in the constant magnetic field, and the vibrator unit is electrically connected with the measuring unit; the oscillator unit is used for driving the second capacitance plate array to move relative to the first capacitance plate array when an oscillator moves due to external vibration so as to generate a capacitance change signal; driving the metal coil to move so as to generate an induced current signal; and the measurement unit is used for measuring the seismic signal of the target frequency band based on the capacitance change signal and the induced current signal. According to the invention, seismic signal measurement covering a large dynamic range and a large frequency range can be realized, and meanwhile, high-resolution seismic signal measurement is realized.

Description

Technical Field

[0001] The present application belongs to the technical field of seismic exploration, and more specifically, to a seismic geophone and a measurement method thereof. Background Art

[0002] Seismometers are instruments that measure the movement of the ground when it is disturbed. Measuring this ground motion with seismometers is often not easy because of the large amplitude and frequency range of earthquake signals.

[0003] At present, the commonly used seismic detector in the field of seismic exploration is the moving coil velocity detector. However, in the above-mentioned moving coil velocity detector, due to the limitation of its working principle, it can only record vibration signals higher than the natural frequency of its spring-oscillator system, and is insensitive to lower frequency signals. Although it has high sensitivity, its typical dynamic range is only 60dB, and it cannot detect larger vibration signals. Acceleration sensors are also commonly used for strong earthquake signal detection. According to their working principle, they can detect acceleration signals lower than their natural frequency, but their sensitivity is usually lower than that of moving coil velocity-type seismic detectors, so they are often used to detect strong vibrations. Therefore, using a moving coil velocity-type seismic detector or an acceleration-type seismic detector alone cannot effectively measure seismic signals covering a large dynamic range and a large frequency range. Using the above two types of seismic detectors at the same time is bound to increase costs.

[0004] Therefore, how to realize a single seismic detector that can simultaneously detect seismic signals covering a large dynamic range and a large frequency range is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0005] In view of the defects of the prior art, the purpose of the present application is to realize a single seismic detector that can simultaneously detect seismic signals covering a large dynamic range and a large frequency range.

[0006] To achieve the above objectives, in a first aspect, the present application provides a seismic detector, comprising:

[0007] A vibrator unit, an upper cover plate arranged in parallel and directly above the vibrator unit, and a measuring unit;

[0008] A first capacitor plate array is deposited on the lower surface of the upper cover plate, and a second capacitor plate array and a metal coil are deposited on the upper surface of the vibrator of the vibrator unit; the projections of the first capacitor plate array and the second capacitor plate array in the vertical direction completely overlap; the vibrator unit is set in a constant magnetic field, and the vibrator unit is electrically connected to the measuring unit;

[0009] The vibrator unit is used to drive the second capacitor plate array to move relative to the first capacitor plate array to generate a capacitance change signal when the vibrator moves due to external vibration, and drive the metal coil to move to generate an induced current signal;

[0010] The measuring unit is used to measure a seismic signal in a target frequency band based on the capacitance change signal and the induced current signal.

[0011] Optionally, the vibrator unit includes a proof mass, a connecting beam, an outer frame, and a spring structure symmetrically distributed on both sides of the proof mass; the proof mass is connected to the spring structure via the connecting beam, and the spring structure is connected to the outer frame via the connecting beam; the vibrator is the proof mass.

[0012] Optionally, the second capacitor plate array of the metal deposited on the upper surface of the inspection mass of the vibrator unit is arranged inside the metal coil of the metal deposition.

[0013] Optionally, the seismic detector further comprises an upper yoke, an upper magnetic pole piece, a lower yoke and a lower magnetic pole piece;

[0014] The upper magnetic pole piece and the lower magnetic pole piece are arranged parallel and symmetrically above and below the vibrator unit, and the orthographic projections of the upper magnetic pole piece and the lower magnetic pole piece on the inspection mass both cover the metal coil; the upper magnetic pole piece is arranged above the upper cover plate;

[0015] The upper yoke is arranged directly above the upper magnetic pole piece, and the lower yoke is arranged directly below the lower magnetic pole piece, and is used to control the magnetic field generated by the upper magnetic pole piece and the lower magnetic pole piece to vertically pass through the metal coil.

[0016] Optionally, the measuring unit includes a speed measuring unit, an acceleration measuring unit and a main control unit; the speed measuring unit and the acceleration measuring unit are respectively connected to the main control unit;

[0017] The speed measurement unit is used to analyze the induced current signal to determine a first digital signal corresponding to the speed information of the vibrator;

[0018] The acceleration measurement unit is used to analyze the capacitance change signal to determine a second digital signal corresponding to the acceleration information of the vibrator;

[0019] The main control unit is used to measure the seismic signal in the target frequency band based on the first digital signal and the second digital signal.

[0020] Optionally, the speed measurement unit includes a speed sensing subunit, a speed measurement and control circuit and a first analog-to-digital converter;

[0021] The speed sensing subunit is used to convert the induced current signal into a corresponding first voltage change signal;

[0022] The speed measurement and control circuit is used to measure the speed analog signal of the vibrator based on the first voltage change signal;

[0023] The first analog-to-digital converter is used to convert the velocity analog signal of the vibrator into a corresponding first digital signal.

[0024] Optionally, the acceleration measurement unit includes an acceleration sensor subunit, an acceleration measurement and control circuit, and a second analog-to-digital converter;

[0025] The acceleration sensor subunit is used to convert the capacitance change signal into a corresponding second voltage change signal;

[0026] The acceleration measurement and control circuit is used to measure the acceleration analog signal of the vibrator based on the second voltage change signal;

[0027] The second analog-to-digital converter is used to convert the acceleration analog signal of the vibrator into a corresponding second digital signal.

[0028] In a second aspect, the present application further provides a measurement method applied to a seismic geophone as described in any one of the above, the method comprising:

[0029] When the vibrator unit is subjected to external vibration and the vibrator moves, a capacitance change signal and an induced current signal are detected simultaneously; the capacitance change signal is an induced signal generated based on the movement of the second capacitor plate array relative to the first capacitor plate array driven by the vibrator; the induced current signal is an induced signal generated based on the movement of the metal coil driven by the vibrator;

[0030] Analyzing the induced current signal to determine a first digital signal corresponding to the speed information of the vibrator;

[0031] Analyze the capacitance change signal to determine a second digital signal corresponding to the acceleration information of the vibrator;

[0032] Based on the first digital signal and the second digital signal, a seismic signal in the target frequency band is measured.

[0033] Optionally, analyzing the induced current signal to determine the first digital signal corresponding to the speed information of the vibrator includes:

[0034] Converting the induced current signal into a corresponding first voltage change signal;

[0035] measuring a velocity analog signal of the vibrator based on the first voltage change signal;

[0036] The velocity analog signal of the vibrator is converted into a corresponding first digital signal.

[0037] Optionally, analyzing the capacitance change signal to determine the second digital signal corresponding to the acceleration information of the vibrator includes:

[0038] Converting the capacitance change signal into a corresponding second voltage change signal;

[0039] measuring an acceleration analog signal of the vibrator based on the second voltage change signal;

[0040] In general, the above technical solutions conceived by this application have the following beneficial effects compared with the prior art:

[0041] The present application provides a seismic detector and a measurement method thereof. A vibrator acceleration and velocity measurement mechanism is integrated through micro-nano processing. A capacitor plate array and a metal coil are simultaneously metal-deposited on the vibrator of the vibrator unit, and a corresponding capacitor plate array is metal-deposited on the lower surface of an upper cover plate above the vibrator, forming a dual structure of capacitance displacement detection and induced current detection, so that the acceleration and velocity of the vibrator can be measured simultaneously on a set of structures. The response frequency band range can reach at least 0.01 Hz to 200 Hz, and the maximum dynamic range can reach 180 dB, so that seismic signal measurement covering a large dynamic range and a large frequency range can be achieved. At the same time, the detector has high integration, small size, and low cost. The weight of the inertial sensitive vibrator can be increased without increasing the chip thickness through the bulk silicon penetration etching process, thereby reducing mechanical thermal noise and improving the sensitivity of the vibrator acceleration to displacement, thereby achieving high-resolution seismic signal measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is one of the structural schematic diagrams of the seismic detector provided in the embodiment of the present application;

[0043] Figure 2 It is a structural schematic diagram of an upper cover plate in a seismic geophone provided in an embodiment of the present application;

[0044] Figure 3 It is a structural schematic diagram of a vibrator unit in a seismic detector provided in an embodiment of the present application;

[0045] Figure 4 This is the second structural schematic diagram of the seismic detector provided in the embodiment of the present application;

[0046] Figure 5 is a schematic diagram of the structure of a measuring unit in a seismic geophone provided in an embodiment of the present application;

[0047] Figure 6 (a) is a schematic diagram of the amplitude-frequency response of the velocity measurement unit in the seismic geophone provided in an embodiment of the present application, and (b) is a schematic diagram of the amplitude-frequency response of the acceleration measurement unit in the seismic geophone provided in an embodiment of the present application;

[0048] Figure 7 It is a flow chart of a measurement method of a seismic geophone provided in an embodiment of the present application;

[0049] Figure 8 It is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0051] The terms "first" and "second" in the specification and claims herein are used to distinguish different objects rather than to describe a specific order of the objects. For example, the first capacitor plate array and the second capacitor plate array are used to distinguish different capacitor plate arrays rather than to describe a specific order of the capacitor plate arrays; for another example, the first analog-to-digital converter and the second analog-to-digital converter are used to distinguish analog-to-digital converters for different purposes rather than to describe a specific order of the analog-to-digital converters.

[0052] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0053] In the description of the embodiments of the present application, unless otherwise specified, "plurality" means two or more than two. For example, a plurality of micro capacitor plates refers to two or more than two micro capacitor plates.

[0054] It should be noted that the amplitude and frequency range of seismic signals are very large, with ground motion ranging from 0.1nm to a maximum of 10m, and a dynamic range of 220dB; the frequency ranges from as low as 10% of the solid tide frequency. -5 Hz is extended to 1000Hz. Therefore, it is very difficult to develop an instrument that covers this large dynamic range and frequency range and achieves relatively high sensitivity. Therefore, in order to solve the above technical defects, the present application provides a seismic detector as described below.

[0055] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0056] Figure 1 is one of the structural diagrams of the seismic detector provided in the embodiment of the present application, such as Figure 1 As shown, it is prepared by a micro-electro-mechanical system (MEMS) processing method. The seismic detector includes:

[0057] A vibrator unit 1, an upper cover plate 2 arranged parallel to and directly above the vibrator unit 1, and a measuring unit 3;

[0058] A first capacitor plate array 21 is deposited on the lower surface of the upper cover plate 2, and a second capacitor plate array 111 and a metal coil 112 are deposited on the upper surface of the vibrator 11 of the vibrator unit 1; the projections of the first capacitor plate array 21 and the second capacitor plate array 111 in the vertical direction completely overlap; the vibrator unit 1 is set in a constant magnetic field, and the vibrator unit 1 is electrically connected to the measuring unit 3;

[0059] The vibrator unit 1 is used to drive the second capacitor plate array 111 to move relative to the first capacitor plate array 21 to generate a capacitance change signal when the vibrator 11 moves due to external vibration, and drive the metal coil 112 to move to generate an induced current signal.

[0060] The measuring unit 3 is used to measure the seismic signal of the target frequency band based on the capacitance change signal and the induced current signal.

[0061] Specifically, the first capacitor plate array described in the embodiment of the present application refers to a capacitor plate array formed by metal deposition on the lower surface of the upper cover plate through a photolithography process, which can be specifically composed of a plurality of micro capacitor plates. The specific number of deposited micro capacitor plates can be set according to actual design requirements.

[0062] The second capacitor plate array described in the embodiment of the present application refers to a capacitor plate array formed by metal deposition on the vibrator upper surface of the vibrator unit through a photolithography process, which can also be composed of a plurality of micro capacitor plates. The number of micro capacitor plates deposited in the second capacitor plate array is the same as or greater than that of the first capacitor plate array.

[0063] It should be noted that, in the embodiments of the present application, the vibrator unit and the upper cover plate may be made of a silicon substrate material covered with silicon dioxide.

[0064] The seismic signal of the target frequency band described in the embodiment of the present application refers to a seismic signal covering a low frequency band lower than the eigenfrequency of the vibrator unit and a high frequency band higher than the eigenfrequency of the vibrator unit.

[0065] In the embodiment of the present application, deep silicon etching can be used to penetrate and etch the entire silicon wafer, increase the weight of the inertial sensitive vibrator without increasing the thickness of the chip, and deposit the second capacitor plate array and the metal coil on the vibrator upper surface of the vibrator unit at the same time. At the same time, the upper cover plate arranged parallel to the upper part of the vibrator unit also deposits the first capacitor plate array of the same size on its lower surface, so that when the instrument is in a static state, the upper cover plate and the vibrator unit are both arranged horizontally, the first capacitor plate array and the second capacitor plate array are arranged opposite each other, and the projections of the first capacitor plate array and the second capacitor plate array in the vertical direction completely overlap, forming a capacitive displacement detection structure.

[0066] Figure 2 is a schematic diagram of the structure of the upper cover plate in the seismic detector provided in the embodiment of the present application, such as Figure 2 As shown, a first capacitor plate array 21 is metal-deposited at a specific position on the lower surface of the upper cover plate 2. The specific position can be determined according to the position of the second capacitor plate array on the vibrator inside the vibrator unit, as long as the first capacitor plate array and the second capacitor plate array are arranged opposite to each other.

[0067] Furthermore, in an embodiment of the present application, the vibrator unit is disposed in a constant magnetic field, and the magnetic field vertically passes through the metal coil on the surface of the vibrator unit, thereby forming an induced current detection structure.

[0068] Thus, in the working state of the seismic detector of the embodiment of the present application, when the vibrator unit is subjected to external vibration and causes the internal vibrator to move, it can drive the capacitor plate array on the vibrator to move relative to the capacitor plate array on the upper cover plate, thereby generating a capacitance change signal. At the same time, the moving vibrator will also drive the metal coil to move in the constant magnetic field, and the metal coil cuts the magnetic flux lines, generating an induced electromotive force, and then generating an induced current signal.

[0069] Furthermore, in an embodiment of the present application, a signal routing is formed by photolithography and metal deposition, and a signal output terminal can be set on the vibrator unit to electrically connect the vibrator unit to the measuring unit. In this way, the measuring unit can receive the capacitance change signal and the induced current signal generated by the movement of the vibrator unit in real time, and by performing vibrator acceleration measurement and analysis on the received capacitance change signal, the seismic signal measurement in the low frequency band below the eigenfrequency of the vibrator unit can be realized; by performing vibrator velocity measurement and analysis on the received induced current signal, the seismic signal measurement in the high frequency band above the eigenfrequency of the vibrator unit can be realized. Finally, based on the fusion and splicing processing of the two types of measurement result data, the seismic signal of the target frequency band can be measured, and the response frequency band range can reach at least 0.01Hz to 200Hz, and the maximum dynamic range can reach 180dB.

[0070] It should be noted that in the embodiments of the present application, by adopting deep silicon etching to penetrate the entire silicon wafer, the weight of the inertial sensitive vibrator can be increased without increasing the thickness of the chip, thereby effectively reducing mechanical thermal noise and improving the sensitivity of the vibrator acceleration to displacement, thereby achieving a higher resolution than existing MEMS seismic detectors or MEMS accelerometers, and the measurement resolution can reach 5ng.

[0071] In addition, in an embodiment of the present application, a MEMS processing method for manufacturing a metal coil and a capacitor plate array on a vibrator unit, and a signal jumper lead-out thereof is provided, and the specific steps are as follows:

[0072] Step 110, transferring the signal wiring pattern to the surface of the silicon substrate covered with silicon dioxide by photolithography, and evaporating metal to form a metal coil jumper wiring;

[0073] Step 120, using physical vapor deposition technology (PECVD) to form a silicon dioxide film on the surface of the silicon substrate to cover the wiring;

[0074] Step 130, etching the silicon dioxide outside the metal trace by reactive ion etching (RIE) to open a window;

[0075] Step 140, transfer the capacitor plate and metal coil pattern to the surface of the silicon substrate through a photolithography process, and evaporate and deposit metal to form a capacitor plate array and a metal coil, and connect them to the metal wiring in the window to complete the signal jumper lead-out.

[0076] The seismic detector of the embodiment of the present application integrates a vibrator acceleration and velocity measurement mechanism through micro-nano processing, and simultaneously deposits a capacitor plate array and a metal coil on the vibrator of the vibrator unit, and deposits a corresponding capacitor plate array on the lower surface of the upper cover plate above it, forming a dual structure of capacitance displacement detection and induced current detection, so that the vibrator acceleration and velocity measurement can be performed simultaneously on a set of structures, the response frequency band range can reach at least 0.01Hz to 200Hz, and the maximum dynamic range can reach 180dB, which can realize seismic signal measurement covering a large dynamic range and a large frequency range. At the same time, the detector has high integration, small size and low cost. Through the bulk silicon penetration etching process, the weight of the inertial sensitive vibrator can be increased without increasing the chip thickness, thereby reducing mechanical thermal noise and improving the sensitivity of the vibrator acceleration to displacement, thereby realizing high-resolution seismic signal measurement.

[0077] Figure 3 is a schematic diagram of the structure of the vibrator unit in the seismic detector provided in the embodiment of the present application, such as Figure 3As shown, in the implementation of the present application, the vibrator unit 1 includes a test mass 11, a connecting beam 12, an outer frame 13, and a spring structure 14 symmetrically distributed on both sides of the test mass 11; the test mass 11 is connected to the spring structure 14 through the connecting beam 12, and the spring structure 14 is connected to the outer frame 13 through the connecting beam 12; the vibrator 11 is the test mass.

[0078] Specifically, in the embodiment of the present application, the internal structure of the vibrator unit is etched on the silicon substrate by a MEMS processing method, wherein the spring structure is composed of etched folded beams, forming a hollow rectangular parallelepiped structure, and the spring expansion and contraction effect is achieved through the hollowed-out part in the middle.

[0079] In the embodiment of the present application, the vibrator inside the vibrator unit adopts a test mass. For the spring structures symmetrically distributed on both sides of the test mass, one side of any spring structure is connected and fixed to the outer frame through a connecting beam, and the other side is connected to the test mass through a connecting beam, so that the test mass can be suspended in the middle position of the vibrator unit and can move freely.

[0080] It should be noted that the sizes of the inspection mass, connecting beam, outer frame and spring structure in the vibrator unit can be set according to actual design requirements, and this application does not make specific limitations on this.

[0081] The seismic detector of the embodiment of the present application constructs a vibrator unit by utilizing a test mass, a connecting beam, an outer frame, and a spring structure. It has a simple structure and is easy to process. It can effectively sense external ground vibrations and has high flexibility, which is beneficial to improving the sensitivity of seismic wave perception.

[0082] Continue to refer to Figure 3 Based on the contents of the above embodiments, as an optional embodiment, the second capacitor plate array 111 etched on the upper surface of the inspection mass 11 of the vibrator unit 1 is arranged inside the deposited metal coil 112 .

[0083] Specifically, in the embodiment of the present application, a second capacitor plate array and a metal coil are simultaneously deposited on the upper surface of the inspection mass through micro-nano processing technology, wherein the second capacitor plate array is located inside the metal coil. On the one hand, a capacitive displacement detection structure can be formed by combining the second capacitor plate array disposed on the inspection mass and the second capacitor plate array disposed on the bottom surface of the upper cover plate above it.

[0084] On the other hand, the vibrator unit is arranged in a preset constant magnetic field, so the inspection mass is also located in the constant magnetic field, which can make the constant magnetic field vertically pass through the metal coil deposited on the surface of the inspection mass, thereby forming an induced current detection structure.

[0085] The seismic detector of the embodiment of the present application can improve the utilization rate of the substrate material and save the manufacturing cost while ensuring the effective detection of the induced signal by simultaneously depositing a capacitor plate array and a metal coil on the surface of the inspection mass and etching the capacitor plate array inside the metal coil.

[0086] Figure 4 This is the second structural diagram of the seismic detector provided in the embodiment of the present application, such as Figure 4 As shown, as an optional embodiment, the seismic detector further includes an upper yoke 4, an upper magnetic pole piece 5, a lower yoke 6 and a lower magnetic pole piece 7;

[0087] The upper magnetic pole piece 5 and the lower magnetic pole piece 7 are arranged parallel and symmetrically above and below the vibrator unit 1, and the orthographic projections of the upper magnetic pole piece 5 and the lower magnetic pole piece 7 on the inspection mass 11 both cover the metal coil 112; the upper magnetic pole piece 5 is arranged on the upper surface of the upper cover plate 2;

[0088] The upper yoke 4 is arranged directly above the upper magnetic pole piece 5 , and the lower yoke 6 is arranged directly below the lower magnetic pole piece 7 , and is used to control the magnetic field generated by the upper magnetic pole piece 5 and the lower magnetic pole piece 7 to vertically pass through the metal coil 112 .

[0089] Specifically, in an embodiment of the present application, the seismic detector further includes a structural unit for generating a constant magnetic field, which specifically includes a pair of yokes and a pair of magnetic pole pieces, namely an upper yoke, an upper magnetic pole piece, a lower yoke and a lower magnetic pole piece. It can be understood that the magnetic poles of the upper magnetic pole piece and the lower magnetic pole piece are opposite.

[0090] like Figure 4 As shown, in the embodiments of the present application, each pole piece includes two pole pieces, the upper pole piece and the lower pole piece are symmetrically arranged, and the upper pole piece is arranged above the upper cover plate and arranged in parallel above the vibrator unit, and the lower pole piece is arranged in parallel below the vibrator unit, and the orthographic projections of the upper pole piece and the lower pole piece on the inspection mass can completely cover the metal coil to ensure that the generated magnetic field can completely cover the metal coil on the inspection mass.

[0091] In the embodiment of the present application, the upper yoke is arranged directly above the upper magnetic pole piece, and the lower yoke is arranged directly below the lower magnetic pole piece, forming a "sandwich" structure. The upper and lower yokes can constrain the direction of the magnetic field and control the constant magnetic field generated by the upper magnetic pole piece and the lower magnetic pole piece to vertically pass through the metal coil on the inspection mass.

[0092] like Figure 4As shown, in an embodiment of the present application, the second capacitor plate array 111 on the inspection mass 11 and the first capacitor plate array 21 on the upper cover plate 2 constitute a parallel plate capacitor for measuring the displacement of the inspection mass 11 and thus measuring its acceleration. The upper yoke 4, the upper magnetic pole piece 5, the lower yoke 6 and the lower magnetic pole piece 7 are used to generate a constant magnetic field. When the inspection mass 11 moves, the metal coil 112 will cut the magnetic flux lines in the constant magnetic field to generate an induced current for detecting the speed of the inspection mass 11. It is only necessary to integrate the velocity signal once and the acceleration signal twice. Whether measuring acceleration or velocity, the purpose of measuring ground displacement can be achieved.

[0093] The seismic detector of the embodiment of the present application can stably output a constant magnetic field through the designed sandwich structure of the yoke iron and the pole piece, which is convenient for the metal coil on the test mass to cut the magnetic flux lines, which is beneficial to improving the stability of the test mass velocity measurement and improving the resolution of high-frequency seismic signal detection.

[0094] Figure 5 is a schematic diagram of the structure of the measuring unit in the seismic detector provided in the embodiment of the present application, such as Figure 5 As shown, the measuring unit 3 includes a speed measuring unit 31, an acceleration measuring unit 32 and a main control unit 33; the speed measuring unit 31 and the acceleration measuring unit 32 are connected to the main control unit 33 respectively;

[0095] The speed measurement unit 31 is used to analyze the induced current signal to determine the first digital signal corresponding to the speed information of the vibrator;

[0096] The acceleration measurement unit 32 is used to analyze the capacitance change signal to determine the second digital signal corresponding to the acceleration information of the vibrator;

[0097] The main control unit 33 is used to measure the seismic signal of the target frequency band based on the first digital signal and the second digital signal.

[0098] Specifically, in the embodiment of the present application, the measuring unit can be mainly divided into three parts, including a speed measuring unit, an acceleration measuring unit and a main control unit, wherein the speed measuring unit and the acceleration measuring unit are respectively connected to the main control unit for data communication.

[0099] In the embodiment of the present application, the induced current signal generated by the movement of the metal coil is analyzed by a speed measurement unit, and the first digital signal corresponding to the speed information of the vibrator is determined to achieve the measurement of the vibrator speed.

[0100] Continue to refer to Figure 5 Based on the content of the above embodiment, as an optional embodiment, the speed measurement unit 31 includes a speed sensing subunit 311, a speed measurement and control circuit 312 and a first analog-to-digital converter 313;

[0101] The speed sensing subunit 311 is used to convert the induced current signal into a corresponding first voltage change signal;

[0102] The speed measurement and control circuit 312 is used to measure the speed analog signal of the vibrator based on the first voltage change signal;

[0103] The first analog-to-digital converter 313 is used to convert the velocity analog signal of the vibrator into a corresponding first digital signal.

[0104] Specifically, in an embodiment of the present application, the speed measurement unit includes a speed sensing subunit, a speed measurement and control circuit, and a first analog-to-digital converter. When the induced current signal generated by the metal coil is transmitted to the speed measurement unit, the speed sensing subunit first processes the induced current signal, that is, converts the induced current signal into a corresponding voltage change signal, that is, a first voltage change signal; the speed measurement and control circuit converts the above voltage change signal into a final analog voltage output through a series of signal processing, including but not limited to bandpass filtering, modulation and demodulation, low-pass filtering and other signal processing links, that is, obtains the speed analog signal of the vibrator; the first analog-to-digital converter further converts the speed analog signal of the vibrator into a corresponding digital signal, that is, a first digital signal, so as to transmit the digital signal to the main control unit for processing.

[0105] In the embodiment of the present application, the vibrator may adopt a test mass. For a metal coil, when the test mass moves, the metal coil cuts the magnetic flux lines, and according to Lenz's law, the relationship between the induced electromotive force E and the induced current I generated in the coil is as follows:

[0106] E = n2BLv;

[0107] I = E / R;

[0108] In the formula, n2 represents the number of turns of the metal coil; B represents the magnetic induction intensity; L represents the length of the metal coil cutting the magnetic field line in the magnetic field, which is perpendicular to Figure 3 The direction of movement is shown; v represents the speed of the test mass; R represents the resistance of the metal coil.

[0109] In the embodiment of the present application, the speed measuring unit measures the induced current signal in the metal coil, thereby achieving the purpose of measuring the speed of the inspection mass. The yoke, the magnetic pole piece, the metal coil, the speed sensor subunit, and the speed measurement and control circuit constitute a speed transducer.

[0110] It should be noted that the velocity transducer can actually be regarded as a second-order high-pass filter, and signals with frequencies lower than the eigenfrequency f0 of the vibrator unit will be filtered out. In this way, the velocity transducer can only measure relatively high-frequency seismic signals, but cannot measure low-frequency seismic signals.

[0111] The seismic detector of the embodiment of the present application constructs a velocity measurement unit by utilizing a velocity sensor unit, a velocity measurement and control circuit, and a first analog-to-digital converter, and combines a yoke, a pole piece, and a metal coil on the vibrator to form a velocity transducer. The vibrator has high sensitivity and can effectively measure the velocity changes of the vibrator, thereby achieving high-resolution measurement of high-frequency seismic signals.

[0112] Furthermore, in an embodiment of the present application, an acceleration measurement unit is used to analyze a capacitance change signal generated by the misaligned movement of the upper cover plate and the capacitor plate array on the vibrator, and a second digital signal corresponding to the acceleration information of the vibrator is determined to achieve measurement of the vibrator acceleration.

[0113] Continue to refer to Figure 5 Based on the content of the above embodiment, as an optional embodiment, the acceleration measurement unit 32 includes an acceleration sensor subunit 321, an acceleration measurement and control circuit 322 and a second analog-to-digital converter 323;

[0114] The acceleration sensor subunit 321 is used to convert the capacitance change signal into a corresponding second voltage change signal;

[0115] The acceleration measurement and control circuit 322 is used to measure the acceleration analog signal of the vibrator based on the second voltage change signal;

[0116] The second analog-to-digital converter 323 is used to convert the acceleration analog signal of the vibrator into a corresponding second digital signal.

[0117] Specifically, in an embodiment of the present application, the acceleration measurement unit includes an acceleration sensor subunit, an acceleration measurement and control circuit, and a second analog-to-digital converter. When the capacitance change signal generated by the two capacitor plate arrays is transmitted to the acceleration measurement unit, the acceleration sensor subunit first processes the capacitance change signal, that is, converts the capacitance change signal into a corresponding voltage change signal, that is, a second voltage change signal; the acceleration measurement and control circuit converts the above voltage change signal into a final analog voltage output through a series of signal processing, including but not limited to bandpass filtering, modulation and demodulation, low-pass filtering and other signal processing links, that is, obtains the acceleration analog signal of the vibrator; the second analog-to-digital converter further converts the acceleration analog signal of the vibrator into a corresponding digital signal, that is, a second digital signal, so as to transmit the digital signal to the main control unit for processing.

[0118] In the embodiment of the present application, the vibrator may use a test mass. When the test mass moves, according to Newton's second law, the relationship between the acceleration change and the displacement of the test mass, the relationship between the capacitance change and the displacement change, and the relationship between the voltage change and the capacitance change can be expressed as follows:

[0119] Δx=Δa / ω0 2 ;

[0120] ΔC=2n1εlΔx / d;

[0121] ΔV=V f ΔC / C f ;

[0122] Wherein, Δx represents the displacement of the test mass; Δa represents the change of gravity acceleration; ω0 represents the eigenfrequency of the vibrator unit; ΔC represents the capacitance change; n1 represents the number of facing plates of the first capacitor plate array and the second capacitor plate array; ε represents the dielectric constant; l represents the plate length; d represents the distance between the facing plates; V f Indicates the carrier amplitude; ΔV indicates the voltage change; C f Represents the feedback capacitor.

[0123] When the seismic detector is subjected to ground vibration and the inspection mass moves, the overlapping area of ​​the capacitor formed by the capacitor plate array on the upper cover and the capacitor plate array on the inspection mass will change, and the acceleration measurement unit will measure the capacitance change, thereby achieving the purpose of measuring the acceleration change of the inspection mass. The vibrator unit, the first capacitor plate array, the second capacitor plate array and the subsequent acceleration sensor subunit and the acceleration measurement and control circuit constitute an acceleration transducer.

[0124] It should be noted that for the acceleration transducer, its open-loop working mode can be regarded as a second-order low-pass filter, which can measure relatively low-frequency seismic signals, while seismic signals with frequencies higher than the eigenfrequency f0 of the vibrator unit will be attenuated, making it impossible to measure high-frequency seismic signals.

[0125] The seismic detector of the embodiment of the present application constructs an acceleration measurement unit by utilizing an acceleration sensor unit, an acceleration measurement and control circuit, and a second analog-to-digital converter, and combines a vibrator unit, a first capacitor plate array, and a second capacitor plate array to form an acceleration transducer. The acceleration change of the vibrator can be effectively measured to achieve high-resolution measurement of low-frequency seismic signals.

[0126] Furthermore, in an embodiment of the present application, through the main control unit, the measurement results of the aforementioned velocity measurement unit and acceleration measurement unit are fused, and the acceleration signal with a frequency lower than the eigenfrequency f0 of the vibrator unit and the velocity signal with a frequency higher than the eigenfrequency f0 of the vibrator unit are spliced ​​to realize the measurement of the wide-band seismic signal of the seismic detector.

[0127] Figure 6(a) is a schematic diagram of the amplitude-frequency response of the velocity measurement unit in the seismic detector provided in the embodiment of the present application, and (b) is a schematic diagram of the amplitude-frequency response of the acceleration measurement unit in the seismic detector provided in the embodiment of the present application. It can be seen from the figure that the velocity signal with a frequency higher than the eigenfrequency f0 of the vibrator unit and the acceleration signal with a frequency lower than the eigenfrequency f0 of the vibrator unit are both flat in their respective frequency bands. Through signal fusion and splicing, the measurement of wide-band seismic signals of the seismic detector can be realized.

[0128] The seismic detector of the embodiment of the present application divides the acceleration and velocity measurements into two channels for detection, which are independent of each other. The measurement data of the two channels are output in digital form after data fusion operation by the main control unit. The measurement results can cover the low frequency band below the eigenfrequency f0 of the vibrator unit and the high frequency band above the eigenfrequency f0 of the vibrator unit. The measurement frequency range is wide, and it is a large-scale, low-cost solution that can be implemented in the field of seismic exploration.

[0129] The measurement method of the seismic detector provided in the present application is described below. The measurement method of the seismic detector described below and the seismic detector described above can be referenced to each other.

[0130] Figure 7 is a flow chart of a method for measuring a seismic detector provided in an embodiment of the present application, which can be applied to any of the aforementioned seismic detectors, such as Figure 7 As shown, the method includes:

[0131] Step S1, when the vibrator unit is subjected to external vibration and the vibrator moves, a capacitance change signal and an induced current signal are detected simultaneously; the capacitance change signal is an induced signal generated based on the movement of the second capacitor plate array relative to the first capacitor plate array driven by the vibrator; the induced current signal is an induced signal generated based on the movement of the metal coil driven by the vibrator;

[0132] Step S2, analyzing the induced current signal to determine a first digital signal corresponding to the speed information of the vibrator;

[0133] Step S3, analyzing the capacitance change signal to determine a second digital signal corresponding to the acceleration information of the vibrator;

[0134] Step S4: measuring a seismic signal in a target frequency band based on the first digital signal and the second digital signal.

[0135] Based on the content of the above embodiment, as an optional embodiment, analyzing the induced current signal to determine the first digital signal corresponding to the speed information of the vibrator includes:

[0136] Converting the induced current signal into a corresponding first voltage change signal;

[0137] Measuring a velocity analog signal of the vibrator based on the first voltage change signal;

[0138] The velocity analog signal of the vibrator is converted into a corresponding first digital signal.

[0139] Based on the content of the above embodiment, as an optional embodiment, analyzing the capacitance change signal to determine the second digital signal corresponding to the acceleration information of the vibrator includes:

[0140] Converting the capacitance change signal into a corresponding second voltage change signal;

[0141] Measuring an acceleration analog signal of the vibrator based on the second voltage change signal;

[0142] The acceleration analog signal of the vibrator is converted into a corresponding second digital signal.

[0143] It should be understood that the above method is applied to execute the seismic detector in the above embodiment. The implementation principle and technical effects of the method are similar to those described in the above seismic detector embodiment. The execution process of the method can refer to the corresponding measurement process in the above seismic detector embodiment, which will not be repeated here.

[0144] The measurement method of the seismic detector of the embodiment of the present application integrates the vibrator acceleration and velocity measurement mechanism through micro-nano processing, simultaneously metal-deposits a capacitor plate array and a metal coil on the vibrator of the vibrator unit, and deposits a corresponding capacitor plate array on the lower surface of the upper cover plate above it, forming a dual structure of capacitance displacement detection and induced current detection, so that the vibrator acceleration and velocity measurement can be performed simultaneously on a set of structures, the response frequency band range can reach at least 0.01Hz to 200Hz, and the maximum dynamic range can reach 180dB, which can realize seismic signal measurement covering a large dynamic range and a large frequency range. At the same time, the detector has high integration, small size and low cost. Through the bulk silicon penetration etching process, the weight of the inertial sensitive vibrator can be increased without increasing the chip thickness, thereby reducing mechanical thermal noise and improving the sensitivity of the vibrator acceleration to displacement, thereby realizing high-resolution seismic signal measurement.

[0145] Based on the method in the above embodiment, the embodiment of the present application provides an electronic device, such as Figure 8 As shown, the electronic device may include: a processor (Processor) 810, a communication interface (CommunicationsInterface) 820, a memory (Memory) 830 and a communication bus 840, wherein the processor 810, the communication interface 820, and the memory 830 communicate with each other through the communication bus 840. The processor 810 can call the logic instructions in the memory 830 to execute the method in the above embodiment.

[0146] In addition, the logic instructions in the above-mentioned memory 830 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application.

[0147] Based on the method in the above embodiment, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program. When the computer program runs on a processor, the processor executes the method in the above embodiment.

[0148] Based on the method in the above embodiment, an embodiment of the present application provides a computer program product. When the computer program product runs on a processor, the processor executes the method in the above embodiment.

[0149] It is understandable that the processor in the embodiment of the present application may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0150] The method steps in the embodiments of the present application can be implemented by hardware or by a processor executing software instructions. The software instructions can be composed of corresponding software modules, and the software modules can be stored in random access memory (RAM), flash memory, read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, mobile hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and the storage medium can be located in an ASIC.

[0151] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted through the computer-readable storage medium. The computer instructions may be transmitted from a website site, a computer, a server or a data center to another website site, a computer, a server or a data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or a data center that includes one or more available media integrated. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state drive (SSD)), etc.

[0152] It should be understood that the various numerical numbers involved in the embodiments of the present application are only used for the convenience of description and are not used to limit the scope of the embodiments of the present application.

[0153] It should be understood that expressions such as "including" and "may include" that may be used in the present application indicate the existence of the disclosed functions, operations, or constituent elements, and do not limit one or more additional functions, operations, and constituent elements. In the present application, terms such as "including" and / or "having" may be interpreted as indicating specific characteristics, numbers, operations, constituent elements, components, or combinations thereof, but may not be interpreted as excluding the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.

[0154] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. Among them, "fixed connection" means that the relative position relationship after connection remains unchanged. "Rotational connection" means that the two are connected to each other and can rotate relative to each other after connection. "Sliding connection" means that the two are connected to each other and can slide relative to each other after connection. The directional terms mentioned in the embodiments of the present application, such as "upper", "lower", "inner", "outer", "left", "right", etc., are only reference directions of the accompanying drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of the present application, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0155] In addition, in the embodiments of the present application, the mathematical concepts mentioned are symmetry, equality, parallelism, and verticality. These limitations are all for the current level of technology, rather than absolutely strict definitions in the mathematical sense. A small amount of deviation is allowed, and approximate symmetry, approximate equality, approximate parallelism, and approximate verticality are all acceptable. For example, the upper cover plate is parallel to the vibrator unit, which means that the upper cover plate and the vibrator unit are parallel or approximately parallel, and the angle between the upper cover plate and the vibrator unit can be between 0 and 10 degrees. The direction of the magnetic field is perpendicular to the plane where the metal coil is located, which means that the direction of the magnetic field is perpendicular or approximately perpendicular to the plane where the metal coil is located, and the angle between them can be between 80 and 100 degrees.

[0156] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A seismic geophone, characterized in that: include: A vibrator unit, an upper cover plate arranged in parallel and directly above the vibrator unit, and a measuring unit; A first capacitor plate array is deposited on the lower surface of the upper cover plate, and a second capacitor plate array and a metal coil are deposited on the upper surface of the vibrator of the vibrator unit; the projections of the first capacitor plate array and the second capacitor plate array in the vertical direction completely overlap; the vibrator unit is set in a constant magnetic field, and the vibrator unit is electrically connected to the measuring unit; The vibrator unit is used to drive the second capacitor plate array to move relative to the first capacitor plate array to generate a capacitance change signal when the vibrator moves due to external vibration, and drive the metal coil to move to generate an induced current signal; The measuring unit is used to measure a seismic signal in a target frequency band based on the capacitance change signal and the induced current signal.

2. The seismic detector according to claim 1, characterized in that The vibrator unit includes a test mass, a connecting beam, an outer frame, and a spring structure symmetrically distributed on both sides of the test mass; the test mass is connected to the spring structure through the connecting beam, and the spring structure is connected to the outer frame through the connecting beam; the vibrator is the test mass.

3. The seismic detector according to claim 2, characterized in that The second capacitor plate array of the metal deposition on the upper surface of the inspection mass of the vibrator unit is arranged inside the metal coil of the metal deposition.

4. The seismic detector according to claim 2, characterized in that The seismic geophone also includes an upper yoke, an upper magnetic pole piece, a lower yoke and a lower magnetic pole piece; The upper magnetic pole piece and the lower magnetic pole piece are arranged parallel and symmetrically above and below the vibrator unit, and the orthographic projections of the upper magnetic pole piece and the lower magnetic pole piece on the inspection mass both cover the metal coil; the upper magnetic pole piece is arranged above the upper cover plate; The upper yoke is arranged directly above the upper magnetic pole piece, and the lower yoke is arranged directly below the lower magnetic pole piece, and is used to control the magnetic field generated by the upper magnetic pole piece and the lower magnetic pole piece to vertically pass through the metal coil.

5. The seismic geophone according to any one of claims 1 to 4, characterized in that: The measuring unit comprises a speed measuring unit, an acceleration measuring unit and a main control unit; the speed measuring unit and the acceleration measuring unit are respectively connected to the main control unit; The speed measurement unit is used to analyze the induced current signal to determine a first digital signal corresponding to the speed information of the vibrator; The acceleration measurement unit is used to analyze the capacitance change signal to determine a second digital signal corresponding to the acceleration information of the vibrator; The main control unit is used to measure the seismic signal in the target frequency band based on the first digital signal and the second digital signal.

6. The seismic detector according to claim 5, characterized in that The speed measurement unit includes a speed sensing subunit, a speed measurement and control circuit and a first analog-to-digital converter; The speed sensing subunit is used to convert the induced current signal into a corresponding first voltage change signal; The speed measurement and control circuit is used to measure the speed analog signal of the vibrator based on the first voltage change signal; The first analog-to-digital converter is used to convert the velocity analog signal of the vibrator into a corresponding first digital signal.

7. The seismic detector according to claim 5, characterized in that The acceleration measurement unit includes an acceleration sensor subunit, an acceleration measurement and control circuit and a second analog-to-digital converter; The acceleration sensor subunit is used to convert the capacitance change signal into a corresponding second voltage change signal; The acceleration measurement and control circuit is used to measure the acceleration analog signal of the vibrator based on the second voltage change signal; The second analog-to-digital converter is used to convert the acceleration analog signal of the vibrator into a corresponding second digital signal.

8. A measurement method applied to a seismic geophone as claimed in any one of claims 1 to 7, characterized in that: The measuring method comprises: When the vibrator unit is subjected to external vibration and the vibrator moves, a capacitance change signal and an induced current signal are detected simultaneously; the capacitance change signal is an induced signal generated based on the movement of the second capacitor plate array relative to the first capacitor plate array driven by the vibrator; the induced current signal is an induced signal generated based on the movement of the metal coil driven by the vibrator; Analyzing the induced current signal to determine a first digital signal corresponding to the speed information of the vibrator; Analyze the capacitance change signal to determine a second digital signal corresponding to the acceleration information of the vibrator; Based on the first digital signal and the second digital signal, a seismic signal in the target frequency band is measured.

9. The measuring method according to claim 8, characterized in that: The analyzing the induced current signal to determine the first digital signal corresponding to the speed information of the vibrator includes: Converting the induced current signal into a corresponding first voltage change signal; measuring a velocity analog signal of the vibrator based on the first voltage change signal; The velocity analog signal of the vibrator is converted into a corresponding first digital signal.

10. The measuring method according to claim 8, characterized in that: The analyzing the capacitance change signal to determine the second digital signal corresponding to the acceleration information of the vibrator includes: Converting the capacitance change signal into a corresponding second voltage change signal; measuring an acceleration analog signal of the vibrator based on the second voltage change signal; The acceleration analog signal of the vibrator is converted into a corresponding second digital signal.

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