Multi-component seismic wave signal acquisition device for coal mine tunneling face

Abstract

The utility model relates to the technical field of seismic wave signal collection, especially relates to a multi-component seismic wave signal collection device for the coal mine roadway tunneling face, including circuit board, three component geophone, including multistage differential amplifier circuit, wide frequency band collection module, adaptive power management circuit and temperature compensation crystal oscillator chip on the circuit board, multistage differential amplifier circuit is equipped with three groups, respectively with three component geophone's three acceleration sensor corresponding connection, each multistage differential amplifier circuit adopts two stage differential circuit structure, wherein, the first stage differential circuit is the chopping steady zero amplifier circuit of configurable gain, and the second stage differential circuit is low noise operational amplifier circuit, the wide frequency band collection module contains microcontroller, multichannel synchronous sampling AD conversion chip, and is connected through copper foil wiring with each multistage differential amplifier circuit output respectively, the utility model can realize high dynamic range and high signal fidelity in the coal mine well collection environment simultaneously.

Description

Technical Field

[0001] This utility model relates to the field of seismic wave signal acquisition technology, and in particular to a multi-component seismic wave signal acquisition device for coal mine roadway excavation faces. Background Technology

[0002] The geological conditions at coal mine roadway excavation faces are complex, with numerous unknown geological structures such as faults and collapse columns. These structures seriously affect safe coal mine production. Seismic wave exploration technology is an effective means of detecting these geological structures. However, the underground environment of coal mines is characterized by strong noise, which places special requirements on seismic wave signal acquisition devices. Currently, the seismic wave signal acquisition devices used at coal mine roadway excavation faces, such as the data acquisition device for coal mines disclosed in CN111443383B, have insufficient dynamic range, cannot handle both strong and weak signals, and are easily affected by environmental factors, leading to signal distortion. Utility Model Content

[0003] The technical problem to be solved by this utility model is to overcome the existing defects and provide a multi-component seismic wave signal acquisition device for coal mine roadway excavation face. In the environment of strong interference and wide-band seismic signal acquisition in underground coal mines, it can simultaneously achieve high dynamic range and high signal fidelity, and effectively solve the problems in the background technology.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a multi-component seismic wave signal acquisition device for coal mine roadway excavation face, including a circuit board and a three-component seismic detector; The circuit board includes a multi-stage differential amplifier circuit, a wideband acquisition module, an adaptive power management circuit, and a temperature-compensated crystal oscillator chip. The multi-stage differential amplifier circuit has three groups, each connected to one of the three accelerometers of the three-component seismic detector. Each group of multi-stage differential amplifier circuits adopts a two-stage differential circuit structure, wherein the first-stage differential circuit is a chopper-stabilized amplifier circuit with configurable gain, and the second-stage differential circuit is a low-noise operational amplifier circuit. The wideband acquisition module includes a microcontroller and a multi-channel synchronous sampling analog-to-digital converter chip, which are connected to the output terminals of each group of multi-stage differential amplifier circuits via copper foil traces. The adaptive power management circuit supplies power to the entire acquisition device circuit and adopts a two-stage voltage regulation design, including a switching pre-regulator and a linear main regulator. The output terminal of the temperature-compensated crystal oscillator chip is connected to the clock input terminal of the microcontroller of the wideband acquisition module via copper foil traces.

[0005] Preferably, the first-stage differential circuit has two sets, which are respectively connected to the positive and negative terminals of the differential signal of the acceleration sensor of the corresponding three-component seismic detector; each signal path includes a chopper stabilizing amplifier, an analog switch, a variable resistor network and a temperature compensation circuit, and the components of the variable resistor network and the temperature compensation circuit are arranged close together on the circuit board with the chopper stabilizing amplifier as the center.

[0006] Preferably, in the positive signal path of the first-stage differential circuit, the non-inverting input of the chopper-stabilized amplifier is connected to the positive terminal of the differential signal of the accelerometer of the three-component seismic detector via copper foil traces, its inverting input is connected to the common terminal of the analog switch via copper foil traces, and its output is connected back to the inverting input via a variable resistor network via copper foil traces; the normally closed terminal of the analog switch is grounded via a first gain resistor, its normally open terminal is grounded via a second gain resistor, and its control terminal is connected to the microcontroller via copper foil traces; the temperature compensation circuit is connected in parallel across the first gain resistor.

[0007] Preferably, the variable resistor network is composed of a digital potentiometer and a fixed resistor connected in series and adopts a coplanar mounting structure. One end of the series branch is connected to the output terminal of the chopper stabilizing amplifier through copper foil traces, and the other end is connected to its inverting input terminal through copper foil traces. The digital interface of the digital potentiometer is connected to the main control computer in the safe zone outside the roadway through the microcontroller of the wideband acquisition module, so as to realize remote programming adjustment; The temperature compensation circuit consists of a negative temperature coefficient thermistor and a precision metal film resistor connected in series.

[0008] Preferably, the second-stage differential circuit consists of a dual-channel low-noise operational amplifier and a second-stage signal conditioning circuit, wherein the second-stage signal conditioning circuit is composed of resistors R5, R6, R7, R8, R9 and R10. The non-inverting input of the first channel of the dual-channel low-noise operational amplifier is connected to the positive output of the first-stage differential circuit through copper foil traces. Its inverting input is grounded through resistor R5 and connected to its output through copper foil traces through resistor R9, forming the positive output V_out+ of the acquisition circuit. The non-inverting input of the second channel of the dual-channel low-noise operational amplifier is connected to the negative output of the first-stage differential circuit through copper foil traces. Its inverting input is grounded through resistor R6 and connected to its output through copper foil traces through resistor R10, forming the negative output V_out- of the acquisition circuit. Resistor R7 is connected between the output of the first low-noise operational amplifier and the inverting input of the second low-noise operational amplifier via copper foil traces. Resistor R8 is connected via copper foil traces between the output of the second low-noise operational amplifier and the inverting input of the first low-noise operational amplifier.

[0009] Preferably, resistors R5 and R6 are resistors with equal resistance values, resistors R9 and R10 are resistors with equal resistance values, and resistors R7 and R8 are resistors with equal resistance values. In the circuit board layout, resistors with equal resistance values ​​are arranged in adjacent positions.

[0010] Preferably, the adaptive power management circuit includes a switching pre-regulator and a linear main regulator connected in sequence; the input terminal of the switching pre-regulator is connected to the downhole power supply, and its output terminal is connected to the input terminal of the linear main regulator through copper foil traces; the output terminal of the linear main regulator supplies power to the entire acquisition device circuit.

[0011] Compared with the prior art, the beneficial effects of this utility model are: By employing a two-stage differential amplifier structure that combines a configurable gain chopper-stabilized amplifier circuit with a remotely programmable digital potentiometer feedback network, the circuit can amplify weak signals with high gain while avoiding saturation of strong signals through hardware range extension, thus achieving distortion-free acquisition of seismic wave signals with a wide amplitude range under strong interference.

[0012] The chopper-stabilized amplification technology effectively suppresses low-frequency noise and DC drift. Through a precisely matched resistor network and temperature compensation circuit, the stability of the amplifier circuit gain across the entire frequency band, especially the high-frequency band, is ensured, thereby improving the fidelity of broadband seismic signals, particularly the high-frequency effective components.

[0013] The differential amplifier structure and physically isolated three-channel independent signal chain design, combined with a unified synchronous sampling clock, effectively suppress common-mode interference and channel crosstalk, providing a hardware foundation for extracting high signal-to-noise ratio and high temporal consistency multi-component seismic wave signals in the strong electromagnetic interference environment of underground coal mines. Attached Figure Description

[0014] Figure 1 This is a block diagram of the overall structure of this utility model; Figure 2 This is the schematic diagram of the first-stage differential circuit of this utility model; Figure 3 This is the schematic diagram of the second-stage differential circuit of this utility model. Detailed Implementation

[0015] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0016] It should be understood that, when used in this specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or sets.

[0017] To keep the drawings concise, only the parts relevant to this invention are shown schematically in each figure, and they do not represent the actual structure of the product. Furthermore, for ease of understanding, in some figures, only one of the components with the same structure or function is schematically depicted, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one."

[0018] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0019] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the specific implementation methods of this utility model will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of this utility model. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0021] Please see Figure 1-3 This utility model provides a technical solution: a multi-component seismic wave signal acquisition device for coal mine roadway excavation face, including a circuit board and a three-component seismic detector. Specifically, in this embodiment, the three-component seismic detector can be a moving-coil three-component detector, which outputs analog differential signals in the X, Y, and Z directions independently.

[0022] The circuit board includes a multi-stage differential amplifier circuit, a wideband acquisition module, an adaptive power management circuit, and a temperature-compensated crystal oscillator chip. The multi-stage differential amplifier circuit has three sets, which are respectively connected to the three acceleration sensors of the three-component seismic detector and are dedicated to processing the signals of the X, Y and Z channels. The advantage of this design is that physical isolation is achieved from the very beginning of the signal chain, which completely avoids crosstalk between channels and provides a hardware foundation for subsequent accurate analysis of wave arrival direction and wave field characteristics.

[0023] Each multi-stage differential amplifier circuit employs a two-stage differential circuit structure. The first-stage differential circuit is a configurable gain chopper-stabilized amplifier circuit, whose main function is to achieve low-noise amplification and dynamic range matching of the initial signal. The second-stage differential circuit is a low-noise operational amplifier circuit, whose main function is to provide stable secondary gain and drive the subsequent load. The wideband acquisition module includes a microcontroller and a multi-channel synchronous sampling analog-to-digital converter chip. This chip integrates multiple independent high-performance Σ-Δ modulators and a shared high-precision digital decimation filter. Specifically, in terms of circuit connections, the multiple analog input channels of this multi-channel synchronous sampling analog-to-digital converter chip are respectively connected to the output terminals of the second-stage differential amplifier circuits of the three multi-stage differential amplifier circuits via copper foil traces. The data output bus of this chip is connected to the microcontroller within the module via copper foil traces. The temperature-compensated crystal oscillator chip serves as the clock source. Its output is connected via a coaxial cable to the clock input of the multi-channel synchronous sampling analog-to-digital converter chip in the wideband acquisition module through copper foil traces. This ensures the phase consistency of the multi-channel sampling clocks and provides a strict time base guarantee for high-precision seismic source positioning based on wave arrival time difference. The adaptive power management circuit supplies power to the entire acquisition device circuit. It adopts a two-stage voltage regulation design, including a sequentially connected switching pre-regulator and a linear main regulator. In terms of circuit connection, the input of the switching pre-regulator is connected to the downhole power supply, which performs preliminary step-down and voltage regulation on the downhole DC power supply with a large fluctuation range, such as 12-36V. Its output is connected to the input of the linear main regulator through copper foil traces. The output of the linear main regulator supplies power to the entire acquisition device circuit.

[0024] Furthermore, the first-stage differential circuit has two sets, which are respectively connected to the positive terminal V_in+ and the negative terminal V_in- of the differential signal of the accelerometer of the corresponding three-component seismic detector; Each signal path includes a chopper-stabilized amplifier, an analog switch, a variable resistor network, and a temperature compensation circuit. In the circuit board layout, the components of the variable resistor network and the temperature compensation circuit are arranged close together around the chopper-stabilized amplifier to provide equal processing for common-mode interference. In addition, its symmetrical amplification structure can effectively suppress even-order harmonic distortion.

[0025] Furthermore, in the positive terminal V_in+ signal path of the first-stage differential circuit, in terms of circuit connection, the non-inverting input terminal of the chopper-stabilized amplifier U1 is connected to the positive terminal V_in+ of the differential signal of the accelerometer of the three-component seismic detector through copper foil traces, and its inverting input terminal is connected to the common terminal of the analog switch U3 through copper foil traces. Its output terminal is connected back to the inverting input terminal through a variable resistor network and copper foil traces. The normally closed terminal of the analog switch U3 is grounded through the first gain resistor R1_HighGain, and its normally open terminal is grounded through the second gain resistor R1_LowGain. Its control terminal is connected to the microcontroller through copper foil traces. By switching between different grounding gain resistors through the analog switch U3, this structure realizes the macroscopic switching of the signal range at the hardware level. It is a simple and fast-responding hardware range extension scheme, enabling the circuit to adapt to signal strengths with huge differences in an instant. The temperature compensation circuit is connected in parallel across the first gain resistor R1_HighGain. This structure can offset the thermal drift of the resistor itself, thereby locking in the accuracy of the high gain level, which is the structural basis for achieving long-term reliable measurement.

[0026] This collaborative working mode, through its hardware construction, jointly ensures the long-term accuracy and adaptability of the preamplifier stage in the complex environment of underground coal mines.

[0027] Furthermore, the variable resistor network is composed of a digital potentiometer U4 and a fixed resistor R3 connected in series, and adopts a coplanar mounting structure, that is, the two are mounted side by side on the same layer of the circuit board, and the pin pads are directly connected through printed copper foil traces on the surface of the circuit board without the use of conductive vias. One end of this series branch is connected to the output terminal of the chopper stabilizing amplifier U1 through copper foil traces, and the other end is connected to its inverting input terminal through copper foil traces, thereby forming a precise feedback network.

[0028] The digital interface of the digital potentiometer U4 (which, as those skilled in the art will know, typically includes a clock line SCL, a data line SDA, and a reset line RESET) is connected to the main control computer in the safe zone outside the roadway via the microcontroller of the broadband acquisition module, enabling remote programming adjustments. Specifically, on the circuit board, the digital interface of the digital potentiometer U4 is connected to the general-purpose I / O pins of the microcontroller on the broadband acquisition module via copper foil traces. This microcontroller establishes a data connection with the main control computer located in the safe zone outside the roadway via a communication bus such as RS485, forming a remote programming channel from the ground computer to the front end of the underground acquisition circuit.

[0029] The temperature compensation circuit is an independent two-terminal network structure, consisting of a negative temperature coefficient thermistor R12 and a precision metal film resistor R13 connected in series via copper foil traces; the two ends of this series combination are directly connected in parallel across the first gain resistor R1_HighGain.

[0030] Furthermore, the second-stage differential circuit consists of a dual-channel low-noise operational amplifier U5, which can be a chip such as OPA1612, which integrates two highly matched operational amplifiers and a second-stage signal conditioning circuit.

[0031] The second-stage signal adjustment circuit consists of resistors R5, R6, R7, R8, R9, and R10. To achieve high precision and stability, these resistors should be precision metal film resistors.

[0032] The non-inverting input of the first channel of the dual-channel low-noise operational amplifier U5 is connected to the positive output of the first-stage differential circuit through copper foil traces. Its inverting input is grounded through resistor R5 and connected to its output through copper foil traces through resistor R9, forming the positive output V_out+ of the acquisition circuit. The non-inverting input of the second channel of the dual-channel low-noise operational amplifier is connected to the negative output of the first-stage differential circuit through copper foil traces. Its inverting input is grounded through resistor R6 and connected to its output through copper foil traces through resistor R10, forming the negative output V_out- of the acquisition circuit. Resistor R7 is connected between the output of the first low-noise operational amplifier and the inverting input of the second low-noise operational amplifier via copper foil traces. Resistor R8 is connected via copper foil traces between the output of the second low-noise operational amplifier and the inverting input of the first low-noise operational amplifier.

[0033] This second-stage differential circuit is not simply a combination of two independent amplifiers, but a complete differential signal processing unit that tightly couples the two operational amplifier channels together through a network of six resistors, R5 to R10. Local feedback resistors R9 and R10 determine the gain, while cross-feedback resistors R7 and R8 force the two channels to work together to suppress common-mode signals. This unique topology enables it to simultaneously perform differential amplification, common-mode rejection, and signal driving functions, providing a high-performance, highly stable second-stage amplification interface for the weak differential signal output from the first-stage circuit.

[0034] Furthermore, resistors R5 and R6 are resistors with equal resistance values, resistors R9 and R10 are resistors with equal resistance values, and resistors R7 and R8 are resistors with equal resistance values; together with the dual-channel low-noise operational amplifier, they form a high common-mode rejection ratio differential amplifier structure with a differential voltage gain of 1 + (R9 / R5).

[0035] In the specific circuit layout, matching resistor pairs, such as R5 and R6, are placed adjacent to each other on the circuit board, and precision metal film resistors with the same temperature coefficient are selected. This structural arrangement ensures that when the ambient temperature changes, the resistance value of each resistor pair will change almost the same way, and their ratio remains unchanged, thereby keeping the differential gain and common-mode rejection capability of the circuit stable throughout the entire operating temperature range.

[0036] The working principle and application principle of this utility model are as follows: High-quality seismic signal acquisition in the complex environment of underground coal mines is achieved through innovative hardware circuit structure. The analog differential signals in the X, Y, and Z directions acquired by the three-component seismic detector are processed by three independent multi-stage differential amplifier circuits, achieving physical isolation from the front end of the signal chain to avoid channel crosstalk.

[0037] The multi-stage differential amplifier circuit employs a two-stage differential structure working in tandem. The first-stage chopper-stabilized amplifier circuit achieves hardware range extension by switching the gain resistor through an analog switch. Combined with a remote programmable feedback network composed of digital potentiometers and a thermistor temperature compensation circuit, it ensures stable gain in a wide downhole temperature environment. The second-stage low-noise operational amplifier circuit achieves differential amplification, common-mode rejection, and signal driving functions simultaneously through a coupling network composed of six precision resistors.

[0038] After amplification, the signals from each channel are converted by a multi-channel synchronous sampling analog-to-digital converter chip integrated with multiple independent Σ-Δ modulators in the wideband acquisition module. This, combined with a unified clock source provided by a temperature-compensated crystal oscillator, ensures phase consistency across the multi-channel sampling. The adaptive power management employs a two-stage architecture of switching pre-regulation and linear main regulation, adapting to wide voltage inputs downhole while providing clean power to analog circuits.

[0039] This end-to-end hardware architecture design ensures the accuracy, synchronization, and environmental adaptability of seismic wave signal acquisition.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A multi-component seismic wave signal acquisition device for coal mine roadway excavation faces, comprising a circuit board and a three-component seismic detector, characterized in that: The circuit board includes a multi-stage differential amplifier circuit, a wideband acquisition module, an adaptive power management circuit, and a temperature-compensated crystal oscillator chip. The multi-stage differential amplifier circuit has three groups, each connected to one of the three accelerometers of the three-component seismic detector. Each group of multi-stage differential amplifier circuits adopts a two-stage differential circuit structure, wherein the first-stage differential circuit is a chopper-stabilized amplifier circuit with configurable gain, and the second-stage differential circuit is a low-noise operational amplifier circuit. The wideband acquisition module includes a microcontroller and a multi-channel synchronous sampling analog-to-digital converter chip, which are connected to the output terminals of each group of multi-stage differential amplifier circuits via copper foil traces. The adaptive power management circuit supplies power to the entire acquisition device circuit and adopts a two-stage voltage regulation design, including a switching pre-regulator and a linear main regulator. The output terminal of the temperature-compensated crystal oscillator chip is connected to the clock input terminal of the microcontroller of the wideband acquisition module via copper foil traces.

2. The multi-component seismic wave signal acquisition device for coal mine roadway excavation face according to claim 1, characterized in that: The first-stage differential circuit has two sets, which are respectively connected to the positive and negative terminals of the differential signal of the acceleration sensor of the corresponding three-component seismic detector. Each signal path includes a chopper stabilizing amplifier, an analog switch, a variable resistor network and a temperature compensation circuit. On the circuit board, the components of the variable resistor network and the temperature compensation circuit are arranged close together with the chopper stabilizing amplifier as the center.

3. The multi-component seismic wave signal acquisition device for coal mine roadway excavation face according to claim 2, characterized in that: In the positive signal path of the first-stage differential circuit, the non-inverting input of the chopper-stabilized amplifier is connected to the positive terminal of the differential signal of the accelerometer of the three-component seismic detector through copper foil traces, its inverting input is connected to the common terminal of the analog switch through copper foil traces, and its output is connected back to the inverting input through a variable resistor network through copper foil traces; the normally closed terminal of the analog switch is grounded through a first gain resistor, its normally open terminal is grounded through a second gain resistor, and its control terminal is connected to the microcontroller through copper foil traces; the temperature compensation circuit is connected in parallel across the first gain resistor.

4. The multi-component seismic wave signal acquisition device for coal mine roadway excavation face according to claim 3, characterized in that: The variable resistor network consists of a digital potentiometer and a fixed resistor connected in series and adopts a coplanar mounting structure. One end of the series branch is connected to the output terminal of the chopper-stabilized amplifier through copper foil traces, and the other end is connected to its inverting input terminal through copper foil traces. The digital interface of the digital potentiometer is connected to the main control computer in the safe zone outside the roadway through the microcontroller of the wideband acquisition module, so as to realize remote programming adjustment; The temperature compensation circuit consists of a negative temperature coefficient thermistor and a precision metal film resistor connected in series.

5. The multi-component seismic wave signal acquisition device for coal mine roadway excavation face according to claim 1, characterized in that: The second-stage differential circuit consists of a dual-channel low-noise operational amplifier and a second-stage signal conditioning circuit, which is composed of resistors R5, R6, R7, R8, R9, and R10. The non-inverting input of the first channel of the dual-channel low-noise operational amplifier is connected to the positive output of the first-stage differential circuit through copper foil traces. Its inverting input is grounded through resistor R5 and connected to its output through copper foil traces through resistor R9, forming the positive output V_out+ of the acquisition circuit. The non-inverting input of the second channel of the dual-channel low-noise operational amplifier is connected to the negative output of the first-stage differential circuit through copper foil traces. Its inverting input is grounded through resistor R6 and connected to its output through copper foil traces through resistor R10, forming the negative output V_out- of the acquisition circuit. Resistor R7 is connected between the output of the first low-noise operational amplifier and the inverting input of the second low-noise operational amplifier via copper foil traces. Resistor R8 is connected via copper foil traces between the output of the second low-noise operational amplifier and the inverting input of the first low-noise operational amplifier.

6. The multi-component seismic wave signal acquisition device for coal mine roadway excavation face according to claim 5, characterized in that: The resistors R5 and R6 are resistors with equal resistance values, the resistors R9 and R10 are resistors with equal resistance values, and the resistors R7 and R8 are resistors with equal resistance values. In the circuit board layout, the resistors with equal resistance values ​​are arranged in adjacent positions.

7. The multi-component seismic wave signal acquisition device for coal mine roadway excavation face according to claim 1, characterized in that: The adaptive power management circuit includes a switching pre-regulator and a linear main regulator connected in sequence; the input of the switching pre-regulator is connected to the downhole power supply, and its output is connected to the input of the linear main regulator through copper foil traces; the output of the linear main regulator supplies power to the entire acquisition device circuit.

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