MEMS (Micro Electro Mechanical System) seismic acquisition system, method and equipment based on double-channel alternate sampling technology

Abstract

The invention belongs to the field of seismic signal acquisition, particularly relates to an MEMS seismic acquisition system, method and equipment based on a double-channel alternate sampling technology, and aims to solve the problem that the system is low in measurement precision and reliability. The system comprises a seismic signal sensing unit used for sensing an external seismic signal and outputting a corresponding displacement signal; the reading unit is used for converting the displacement signal into a voltage signal and carrying out noise suppression through a dual-channel alternate sampling method; the analog-to-digital conversion unit is used for converting the analog voltage signal into a digital signal; the digital signal processing unit is used for processing the digital signal and generating a final output signal and a feedback control signal; and the feedback unit is used for converting the feedback control signal into an analog quantity and feeding the analog quantity back to the seismic signal sensing unit to realize closed-loop control. And the time sequence unit is used for controlling alternate sampling of the double channels and switching of circuit states according to a set time sequence. According to the invention, multi-stage noise suppression is realized, and the measurement precision is improved.

Description

Technical Field

[0001] The present invention belongs to the field of seismic signal acquisition, and in particular relates to a MEMS seismic acquisition system, method and equipment based on a dual-path alternating sampling technology. Background Art

[0002] In applications such as geological surveys and seismic data collection, it is often necessary to continuously and accurately monitor and record extremely weak seismic signals in order to analyze underground structures, stratum changes, or earthquake source characteristics. The noise level of the seismic data acquisition system directly affects the usability and accuracy of the data.

[0003] The noise level of the readout unit directly determines the performance of the MEMS seismic acquisition system. Designing and implementing a low-noise readout unit is a prerequisite for realizing a high-precision MEMS seismic acquisition system. The readout unit of an existing MEMS seismic acquisition system mainly consists of a preamplifier, a sample-and-hold circuit, a switch network, a timing unit, etc. Its design goal is to convert tiny displacement changes into a voltage signal of sufficient amplitude while suppressing various noises as much as possible in the process. Common noise suppression methods include chopper stabilization technology, auto-zero calibration, and correlated double sampling to eliminate 1 / f noise and offset voltage. Chopper stabilization technology separates signal and noise through frequency modulation, while auto-zero calibration and correlated double sampling technologies use feedback capacitors to correct offsets within different sampling time slots to achieve signal-to-noise separation.

[0004] However, in a single-channel readout unit, since there is only one signal path, its noise suppression capability is often insufficient, especially the inability to effectively eliminate switching noise, such as charge injection and clock feedthrough.

[0005] In addition, many existing designs use a pseudo-differential structure, which uses a fixed reference level on one side and signal sampling on the other side to achieve differential processing. However, this asymmetric method easily causes device matching mismatch, resulting in additional errors and dynamic imbalance, reducing the overall accuracy of the system.

[0006] To address these issues, it is urgent to improve the circuit structure. By using symmetrical dual-path and alternating sampling methods, fully differential signal processing and multi-level noise suppression can be achieved, thereby improving the measurement accuracy and reliability of MEMS seismic acquisition systems. Summary of the Invention

[0007] In order to solve the above-mentioned problems in the prior art, namely, the problem that the single-channel readout unit of the existing MEMS seismic acquisition system has insufficient noise suppression capability (such as the inability to eliminate switching noise) and the device matching mismatch caused by the pseudo-differential structure, resulting in reduced system measurement accuracy and reliability, the present invention provides a MEMS seismic acquisition system, method and equipment based on dual-channel alternating sampling technology.

[0008] In a first aspect of the present invention, a MEMS seismic acquisition system based on a dual-channel alternating sampling technique is proposed, the system comprising: Seismic signal sensitive unit, used to sense external seismic signals and output corresponding displacement signals; a readout unit, configured to convert the displacement signal into a voltage signal and perform noise suppression through a dual-channel alternating sampling method; an analog-to-digital conversion unit, configured to convert an analog voltage signal into a digital signal; A digital signal processing unit, configured to process the digital signal and generate a final output signal and a feedback control signal; A feedback unit, configured to convert the feedback control signal into an analog quantity and feed the analog quantity back to the seismic signal sensitive unit to implement closed-loop control; The timing unit is used to control the alternating sampling of the dual channels and the switching of the circuit states according to the set timing.

[0009] Furthermore, the readout unit includes a storage module, a transducer module, a sampling and holding module and a differential amplifier module according to hardware functions; The readout unit is symmetrically provided with an A path and a B path. The A path and the B path alternately complete the storage, transduction and sampling and holding of the signal under the control of the timing unit, and finally perform differential processing on the signal through the differential amplifier module.

[0010] Furthermore, the A channel includes an A channel in-phase storage module, an A channel inverting storage module, an A channel transducer module, and an A channel sampling and holding module; the B channel includes a B channel in-phase storage module, a B channel inverting storage module, a B channel transducer module, and a B channel sampling and holding module; The A-path in-phase storage module is used to store the displacement signal, and the polarity of the stored displacement signal is the same as the output of the seismic signal sensitive unit; The A-path inverting storage module is used to store the displacement signal, and the polarity of the stored displacement signal is opposite to the output of the seismic signal sensitive unit; The B-path in-phase storage module is used to store the displacement signal, and the polarity of the stored displacement signal is the same as the output of the seismic signal sensitive unit; The B-path inverting storage module is used to store the displacement signal, and the polarity of the stored displacement signal is opposite to the output of the seismic signal sensitive unit; The operating windows of the A-path in-phase storage module, the A-path inverted storage module, the B-path in-phase storage module, and the B-path inverted storage module are non-overlapping under the control of the timing unit. Between the operating windows of the A-path in-phase storage module and the A-path inverted storage module, and the B-path in-phase storage module and the B-path inverted storage module, the reference voltage of the seismic signal sensitive unit is reversed, reversing the polarity of the displacement signal. Since the operating frequency of the readout unit is much larger than the noise bandwidth, the noise stored simultaneously with the signal in the in-phase storage module and the inverted storage module can be approximately considered equal. The A-channel transducer module and the B-channel transducer module are used to convert the displacement signal into the voltage domain with a double amplification factor in a differential manner, and to cancel out noise once by differential operation; The A channel sampling and holding module and the B channel sampling and holding module are used to sample and hold the transduced signal; The differential amplifier module is used to differentially amplify the outputs of the A-channel sampling and holding module and the B-channel sampling and holding module, so as to amplify the signal by two times and cancel the noise twice by differential operation, thereby further reducing the noise to a negligible high-order small amount.

[0011] Furthermore, the working cycle of the readout unit includes the following timing phases: Reset phase, used to ground each node of the circuit; The A channel storage phase and the B channel storage phase are used to store the displacement signals of the A channel and the B channel respectively; A channel signal transduction phase, used to calculate the difference between the displacement signals stored in the A channel in-phase storage module and the A channel inverted phase storage module, and convert the displacement signal into a voltage signal; The B channel signal transduction phase is used to calculate the difference between the displacement signals stored in the B channel in-phase storage module and the B channel inverse-phase storage module, and convert the displacement signal into a voltage signal; The sampling and holding phase of channel A and the sampling and holding phase of channel B respectively sample and hold the transduced signal; The differential amplification phase is used to differentially amplify the outputs of the A-channel sampling and holding module and the B-channel sampling and holding module and output them to the analog-to-digital conversion unit.

[0012] Furthermore, in the A-path storage phase and the B-path storage phase, the polarity of the reference voltage of the seismic signal sensitive unit is reversed once, so as to reverse the polarity of the displacement signal.

[0013] Furthermore, the A-channel transducer module and the B-channel transducer module each include: The two input terminals of the fully differential operational amplifier are connected to the differential output nodes of the seismic signal sensitive unit in a time-sharing manner under the control of the timing unit.

[0014] Furthermore, the seismic signal sensitive unit is a displacement sensitive MEMS sensor, and the displacement sensitive MEMS sensor at least includes a capacitive, piezoresistive, piezoelectric or optical interference structure.

[0015] In a second aspect of the present invention, a MEMS seismic acquisition method based on a dual-channel alternating sampling technique is proposed. The method comprises the following steps: Step S1, sensing an external seismic signal through a seismic signal sensitive unit, and outputting a displacement signal corresponding to the seismic signal; Step S2, collecting the displacement signal and noise through the readout unit, and performing noise suppression through a dual-channel alternating sampling method, performing differential amplification on the suppressed output signal, suppressing the noise again and amplifying the effective signal to obtain an analog voltage signal; Step S3, converting the analog voltage signal into a digital signal through an analog-to-digital conversion unit; Step S4, processing the digital signal by a digital signal processing unit to generate a final output signal and a feedback control signal; Step S5: converting the feedback control signal into an analog quantity through a feedback unit and feeding it back to the seismic signal sensitive unit to realize closed-loop control.

[0016] According to a third aspect of the present invention, an electronic device is provided, comprising: at least one processor; and a memory communicatively connected to at least one of the processors; wherein, The memory stores instructions that can be executed by the processor, and the instructions are used to be executed by the processor to implement a MEMS seismic acquisition method based on a dual-channel alternating sampling technology.

[0017] In a fourth aspect, the present invention provides a computer-readable storage medium storing computer instructions for being executed by the computer to implement a MEMS seismic acquisition method based on a dual-path alternating sampling technique.

[0018] Beneficial effects of the present invention: Eliminating switching noise: Dual-channel alternating sampling technology enables time-interleaved signal acquisition and processing on two symmetrical signal paths. This allows switching noise, such as charge injection and clock feedthrough, to form common-mode components in the two differential outputs and be canceled out, significantly suppressing the noise superposition problem in single-channel sampling.

[0019] Resolving pseudo-differential structure mismatch errors: A symmetrical dual-path fully differential signal processing architecture is adopted, eliminating the fixed reference level design, making the two signal paths completely symmetrical. This eliminates the dynamic imbalance and additional offset errors caused by device mismatch from the circuit structure, thereby improving system accuracy.

[0020] Multi-level noise suppression capability: Combining fully differential signal processing with an alternate sampling mechanism, this technology suppresses residual noise in the signal path. This directly addresses the shortcomings of single-channel readout units in existing technologies, enhancing weak signal resolution capabilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Other features, objects and advantages of the present application will become more apparent upon reading the detailed description of non-limiting embodiments made with reference to the following drawings: Figure 1 This is a block diagram of a MEMS seismic acquisition system based on dual-channel alternating sampling technology of the present invention; Figure 2 A circuit for implementing a readout unit according to an embodiment of the present invention; Figure 3 A schematic diagram of the working state of the circuit of the readout unit according to an embodiment of the present invention when in the reset phase; Figure 4 Schematic diagram of the working state of the circuit of the readout unit of the embodiment of the present invention when storing the phase for the A channel; Figure 5 A schematic diagram of the working state of the circuit of the readout unit according to the embodiment of the present invention when the signal is in the transducing phase of the A channel; Figure 6 A schematic diagram of the working state of the circuit of the readout unit according to the embodiment of the present invention when the channel A is in the sample-and-hold phase; Figure 7 Schematic diagram of the working state of the circuit of the readout unit of the embodiment of the present invention when storing the phase for the B channel; Figure 8 A schematic diagram of the working state of the circuit of the readout unit according to the embodiment of the present invention when the signal is in the transducing phase of the B channel; Figure 9 A schematic diagram of the working state of the circuit of the readout unit according to an embodiment of the present invention when the B channel is in the sample-and-hold phase; Figure 10 A schematic diagram of the working state of the circuit of the readout unit according to the embodiment of the present invention when the phase is differential amplification; Figure 11 1 is a diagram showing the corresponding switching states and timing sequences of a specific implementation circuit of a readout unit according to an embodiment of the present invention. DETAILED DESCRIPTION

[0022] The present application will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are intended only to illustrate the relevant invention and are not intended to limit the invention. It should also be noted that, for ease of description, only portions relevant to the relevant invention are shown in the accompanying drawings.

[0023] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0024] The present invention provides a MEMS seismic acquisition system based on a dual-channel alternating sampling technology, the system comprising: Seismic signal sensitive unit, used to sense external seismic signals and output corresponding displacement signals; a readout unit, configured to convert the displacement signal into a voltage signal and perform noise suppression through a dual-channel alternating sampling method; an analog-to-digital conversion unit, configured to convert an analog voltage signal into a digital signal; A digital signal processing unit, configured to process the digital signal and generate a final output signal and a feedback control signal; A feedback unit, configured to convert the feedback control signal into an analog quantity and feed the analog quantity back to the seismic signal sensitive unit to implement closed-loop control; The timing unit is used to control the alternating sampling of the dual channels and the switching of the circuit states according to the set timing.

[0025] The working principle of the present invention is as follows: the seismic signal sensitive unit senses the external input seismic signal, generates a displacement signal that changes with the external input seismic signal, and outputs it to the readout unit; the readout unit converts the displacement signal into a voltage signal that can be processed, and outputs it to the analog-to-digital conversion unit; the analog-to-digital conversion unit converts the analog voltage signal into a digital signal, and outputs it to the digital signal processing unit; the digital signal processing unit processes the digital signal to generate a final output signal and a signal required for feedback control, thereby completing the signal conditioning function; the feedback unit receives the feedback control signal generated by the digital signal processing unit, converts it into an analog quantity, and directly acts on the driving mechanism of the seismic sensitive unit to realize real-time adjustment of the seismic sensitive unit and complete closed-loop control.

[0026] In order to more clearly explain the MEMS seismic acquisition system based on the dual-channel alternating sampling technology of the present invention, the following Figure 1 The present invention is described in detail as follows: Seismic signal sensitive unit, used to sense external seismic signals and output corresponding displacement signals; The input end of the seismic signal sensitive unit is connected to the output end of the feedback unit, and the output end of the seismic signal sensitive unit is connected to the input end of the readout unit; The seismic signal sensitive unit is a displacement sensitive MEMS sensor, which includes but is not limited to capacitive, piezoresistive, piezoelectric or optical interferometric structures. In this embodiment, a MEMS capacitive sensor is preferred.

[0027] a readout unit, configured to convert the displacement signal into a voltage signal and perform noise suppression through a dual-channel alternating sampling method; The readout unit comprises two input terminals connected to the output terminals of the seismic signal sensitive unit and the timing unit respectively, the output terminal of the readout unit is connected to the input terminal of the analog-to-digital conversion unit, the output terminal of the analog-to-digital conversion unit is connected to the input terminal of the digital signal processing unit, the digital signal processing unit is configured with two output terminals, one of which is used to output a signal, and the other output terminal is connected to the input terminal of the feedback unit, and the output terminal of the feedback unit is connected to the input terminal of the seismic signal sensitive unit; Preferably, the readout unit is composed of a capacitance-voltage readout circuit.

[0028] The readout unit includes a transducer module, a sample-and-hold module, and a differential amplifier module according to its hardware functions. Path A and path B are symmetrically arranged inside the readout unit. These two paths alternately perform signal storage, transducer, and sample-and-hold operations under the control of the timing unit, ultimately performing differential processing on the signal through the differential amplifier module. The A channel includes an A channel in-phase storage module, an A channel inverting storage module, an A channel transducer module and an A channel sampling and holding module, and the B channel includes a B channel in-phase storage module, a B channel inverting storage module, a B channel transducer module and a B channel sampling and holding module; The A-path in-phase storage module is used to store the displacement signal, and the polarity of the stored displacement signal is the same as the output of the seismic signal sensitive unit; The A-path inverting storage module is used to store the displacement signal, and the polarity of the stored displacement signal is opposite to the output of the seismic signal sensitive unit; The B-path in-phase storage module is used to store the displacement signal, and the polarity of the stored displacement signal is the same as the output of the seismic signal sensitive unit; The B-path inverting storage module is used to store the displacement signal, and the polarity of the stored displacement signal is opposite to the output of the seismic signal sensitive unit; The working windows of the A-path in-phase storage module, the A-path inverted storage module, the B-path in-phase storage module, and the B-path inverted storage module are non-overlapping under the control of the timing unit. Between the working windows of the A-path in-phase storage module and the A-path inverted storage module, and the B-path in-phase storage module and the B-path inverted storage module, the reference voltage of the seismic signal sensitive unit is reversed, thereby reversing the polarity of the displacement signal. The A-channel transducer module and the B-channel transducer module are used to convert the displacement signal into the voltage domain with a double amplification factor in a differential manner, and to cancel out noise once by differential operation; The A channel sampling and holding module and the B channel sampling and holding module are used to sample and hold the transduced signal; The differential amplifier module is used to differentially amplify the outputs of the A-channel sampling and holding module and the B-channel sampling and holding module and to cancel noise twice by differential operation.

[0029] Among them, the A channel and B channel of the readout unit work alternately, collecting signals and noise twice in one cycle respectively, and completing signal transduction, amplification and noise cancellation once. Then the signal and noise residuals are sampled and stored in their respective sampling capacitors. Finally, they are subtracted through the differential amplification module to further reduce the noise residual to a negligible high-order small amount, and complete the secondary amplification of the signal.

[0030] The output end of the timing unit is connected to the input end of the readout unit; the timing unit is used to control the alternating sampling of the A path and the B path and the switching of the circuit state according to a preset timing.

[0031] Preferably, the timing unit is composed of a crystal oscillator, a phase-locked loop and a corresponding digital logic circuit.

[0032] One working cycle of the readout unit includes the following timing phases: Reset phase (phreset), used to ground each node of the circuit; The A channel storage phase (phAsave) and the B channel storage phase (phBsave) are used to store the displacement signals of the A channel and the B channel respectively; A channel signal transduction phase (phAtrans), used to calculate the difference between the displacement signals stored in the A channel in-phase storage module and the A channel anti-phase storage module, and convert the displacement signal into a voltage signal; B channel signal transduction phase (phBtrans), used to calculate the difference between the displacement signals stored in the B channel in-phase storage module and the B channel anti-phase storage module, and convert the displacement signal into a voltage signal; The sampling and holding phase of channel A (phAsh) and the sampling and holding phase of channel B (phBsh) are used to sample and hold the transduced signal respectively; The differential amplification phase (phdiff) is used to differentially amplify the outputs of the A-channel sample-and-hold module and the B-channel sample-and-hold module.

[0033] In the A-path storage phase and the B-path storage phase, the polarity of the reference voltage of the seismic signal sensitive unit is reversed once, so as to reverse the polarity of the displacement signal.

[0034] The A-channel energy conversion module and the B-channel energy conversion module both include: The two input terminals of the fully differential operational amplifier are connected to the differential output nodes of the seismic signal sensitive unit in a time-sharing manner under the control of the timing unit.

[0035] Storage phase, the equivalent voltage signal of the output node of the same-phase storage module of channels A and B is: ; ; Storage phase, the equivalent voltage signal of the output node of the inverting storage module of the A and B channels is: ; ; Signal transduction phase, differential processing is performed on the equivalent voltage signals of the output nodes of the "in-phase storage module" and "inverting storage module" of channels A and B respectively to obtain the output voltage of the transduction modules of channels A and B. This voltage will be sampled and held by the sampling and holding modules of channels A and B respectively for subsequent differential amplification module processing.

[0036] ; ; In the sample-and-hold phase, the output voltage of the sample-and-hold module is: ; ; In the differential amplification phase, the output voltage of the differential amplification module is: ; Since the operating frequency of the system readout unit is much higher than the noise bandwidth, the noise stored in the "in-phase storage module" and the "inverted phase storage module" can be approximately considered as: ; ; After differential processing of the signal transduction phase, the noise cancels out in the first-order approximation, leaving only the noise residual and : ; ; After the differential amplifier module, the noise residual and Cancel again, and the remaining high-order noise is small , which is negligible compared to the measured signal: ; In the above formula, Represents the equivalent voltage signal of the measured signal. Its original physical dimension can be different types such as capacitance signal, resistance signal, voltage signal, light intensity signal, etc. according to different types of MEMS displacement sensitive sensors; Represents the noise of path A or B. The physical dimension of this noise can be different types of MEMS displacement-sensitive sensors, such as capacitance signal, resistance signal, voltage signal, and light intensity signal. Represents the equivalent voltage signal of the output node of the A or B channel, the in-phase storage module or the inverting storage module. This voltage signal contains the equivalent voltage signal of the measured signal and noise. Its physical dimension can be different types such as capacitance signal, resistance signal, voltage signal, light intensity signal, etc. according to different types of MEMS displacement sensitive sensors; Represents the noise residual after a difference; Represents the high-order noise element after the second difference.

[0037] like Figure 2 As shown, the specific implementation circuit of the readout unit of the present invention includes a MEMS seismic signal sensitive unit equivalent differential capacitor 1, an A-channel CV readout circuit 2, an A-channel feedback capacitor 3, a B-channel CV readout circuit 4, a B-channel feedback capacitor 5, an A-channel sampling and holding circuit 6, a B-channel sampling and holding circuit 7, a fully differential operational amplifier 8, and a differential amplifier circuit 9.

[0038] Here, the CV readout circuit represents a capacitance-voltage readout circuit.

[0039] In the circuit shown in the figure, the symbol Φxxx represents a corresponding analog switch. Each Φxxx logically has only two states: "on" or "off", which is used to switch the circuit state in different phases. Figure 11 In the middle, a high level indicates that the switch is on, and a low level indicates that the switch is off.

[0040] V P Represents the positive reference voltage; V N Represents negative reference voltage; GND represents system zero potential reference; C FB Represents the feedback capacitor; C HA represents the sampling and holding capacitor of channel A; C HB Represents the sampling and holding capacitor of channel B; VOUTA Represents the output voltage of channel A; V OUTB Represents the output voltage of channel B; V OUT Represents the output voltage of the differential amplifier module.

[0041] Under the control of the timing unit, the specific implementation circuit of the readout unit of the present invention will be in the following working states: Figure 3 This is a schematic diagram of the circuit working state when the timing unit is in the reset phase. In this state, all nodes of the circuit are grounded, all capacitors are cleared, and the circuit output is zero.

[0042] ; Figure 4 This is a schematic diagram of the circuit working state when the timing unit is in the A path storage phase. In this state, the upper plate of the equivalent differential capacitor of the MEMS seismic signal sensitive unit is connected to the positive voltage V P , the lower plate is connected to a negative voltage V N The input of channel A is connected to the middle plate of the equivalent differential capacitor of the MEMS seismic signal sensitive unit. The feedback capacitor of channel A stores the circuit noise. The sampling and holding circuits of channels A and B are disconnected from their respective CV readout circuits. Each node of the CV readout circuit of channel B is kept grounded.

[0043] Figure 5 This is a schematic diagram of the circuit working state when the timing unit is in the A channel signal transduction phase. In this state, the upper plate of the equivalent differential capacitor of the MEMS seismic signal sensitive unit is connected to the negative voltage V N , the lower plate is connected to the positive voltage V P The input of channel A is connected to the middle stage board of the equivalent differential capacitor of the MEMS seismic signal sensitive unit, and the feedback capacitor of channel A is connected to the negative input terminal of the fully differential operational amplifier to convert the changing capacitance signal into a voltage signal.

[0044] Figure 6 Schematic diagram of the circuit working state when the timing unit is in the sample-and-hold phase of channel A. In this state, the sample-and-hold circuit of channel A samples the output voltage of the CV readout circuit of this channel.

[0045] ; Among them, V outA Represents the output voltage of the sample-and-hold module of channel A; C T represents the capacitance between the upper and middle plates of the equivalent differential capacitor of the seismic signal sensitive unit; C B represents the capacitance between the lower and middle plates of the equivalent differential capacitance of the seismic signal sensitive unit; C FB represents the feedback capacitor; V P Represents the positive reference voltage; V NRepresents negative reference voltage; Represents the noise residual of channel A.

[0046] Figure 7 This is a schematic diagram of the circuit working state when the timing unit is in the B channel storage phase. In this state, the A channel sample and hold circuit is first disconnected from the A channel CV readout circuit to maintain the A channel output voltage collected in the previous working state. Subsequently, the remaining A channel nodes are grounded. The upper plate of the equivalent differential capacitor of the MEMS seismic signal sensitive unit is connected to the negative voltage V N , the lower plate is connected to the positive voltage V P , the input of channel B is connected to the middle plate of the equivalent differential capacitor of the MEMS seismic signal sensitive unit, and the feedback capacitor of channel B stores circuit noise.

[0047] Figure 8 This is a schematic diagram of the circuit working state when the timing unit is in the B channel signal transduction phase. In this state, the upper plate of the equivalent differential capacitor of the MEMS seismic signal sensitive unit is connected to the positive voltage V P , the lower plate is connected to a negative voltage V N The input of channel B is connected to the middle-stage plate of the equivalent differential capacitor of the MEMS seismic signal sensitive unit, and the feedback capacitor of channel B is connected to the positive input terminal of the fully differential operational amplifier to convert the changing capacitance signal into a voltage signal.

[0048] Figure 9 Figure 3 is a schematic diagram of the circuit operating state when the timing unit is in the sample-and-hold phase of channel B. In this state, the sample-and-hold circuit of channel B samples the output voltage of the CV readout circuit of this channel. Except for the sample-and-hold capacitor, all nodes of channel A remain grounded.

[0049] ; Among them, V outB Represents the output voltage of the sample-and-hold module of channel B; Represents the B channel noise residual.

[0050] Figure 10 Figure 2 is a schematic diagram of the circuit operating state when the timing unit is in the differential amplification phase. In this state, the sample-and-hold circuits of channels A and B are connected to the two inputs of the differential amplifier circuit. The differential amplifier circuit calculates the difference between the outputs of channels A and B to obtain the final output voltage of the readout unit: .

[0051] The capacitance of the feedback capacitor is configured to match the capacitance of the equivalent differential capacitor.

[0052] The feedback unit includes a digital-to-analog converter and a driving circuit, which is used to convert the digital feedback signal into an analog driving voltage and apply the analog driving voltage to the driving mechanism of the seismic signal sensitive unit.

[0053] The seismic signal sensitive unit has an intermediate plate of an equivalent differential capacitor connected to the input ends of the A-path and B-path transducer modules.

[0054] It should be noted that the above embodiment provides a MEMS seismic acquisition system based on dual-channel alternating sampling technology, which is only illustrated by the division of the above functional modules. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the modules or steps in the embodiments of the present invention can be further decomposed or combined. For example, the modules in the above embodiments can be combined into one module, or further divided into multiple sub-modules to complete all or part of the functions described above. The names of the modules and steps involved in the embodiments of the present invention are only for distinguishing the modules or steps and are not to be regarded as improper limitations on the present invention.

[0055] A second embodiment of the present invention provides a MEMS seismic acquisition method based on a dual-channel alternating sampling technique, based on a MEMS seismic acquisition system based on a dual-channel alternating sampling technique, the method comprising the following steps: Step S1, sensing an external seismic signal through a seismic signal sensitive unit, and outputting a displacement signal corresponding to the seismic signal; Step S2, collecting the displacement signal and noise through the readout unit, and performing noise suppression through a dual-channel alternating sampling method, performing differential amplification on the suppressed output signal, suppressing the noise again and amplifying the effective signal to obtain an analog voltage signal; Step S3, converting the analog voltage signal into a digital signal through an analog-to-digital conversion unit; Step S4, processing the digital signal by a digital signal processing unit to generate a final output signal and a feedback control signal; Step S5: converting the feedback control signal into an analog quantity through a feedback unit and feeding it back to the seismic signal sensitive unit to realize closed-loop control.

[0056] Although the various steps in the above embodiment are described in the above-mentioned order, those skilled in the art will understand that in order to achieve the effect of this embodiment, different steps do not have to be executed in such an order. They can be executed simultaneously (in parallel) or in a reverse order. These simple changes are within the scope of protection of the present invention.

[0057] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working process and related instructions of the method described above can refer to the corresponding process in the aforementioned method embodiment and will not be repeated here.

[0058] An electronic device according to a third embodiment of the present invention includes: at least one processor; and a memory communicatively connected to at least one of the processors; wherein, The memory stores instructions that can be executed by the processor, and the instructions are used to be executed by the processor to implement the above-mentioned MEMS seismic acquisition method based on the dual-channel alternating sampling technology.

[0059] A fourth embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to be executed by the computer to implement the above-mentioned MEMS seismic acquisition method based on the dual-path alternating sampling technology.

[0060] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes and related instructions of the storage device and processing device described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0061] Those skilled in the art should be able to appreciate that the modules and method steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two, and the programs corresponding to the software modules and method steps can be placed in random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disks, removable disks, CD-ROMs, or any other form of storage medium known in the art. In order to clearly illustrate the interchangeability of electronic hardware and software, the above description has generally described the components and steps of each example according to their functions. Whether these functions are performed in electronic hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0062] The terms "first", "second", etc. are used to distinguish similar objects, rather than to describe or indicate a particular order or sequence.

[0063] The term "comprise" or any other similar term is intended to cover non-exclusive inclusion such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0064] Thus far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present invention.

Claims

1. A MEMS seismic acquisition system based on dual-channel alternating sampling technology, characterized in that: The system: Seismic signal sensitive unit, used to sense external seismic signals and output corresponding displacement signals; a readout unit, configured to convert the displacement signal into a voltage signal and perform noise suppression through a dual-channel alternating sampling method; an analog-to-digital conversion unit, configured to convert an analog voltage signal into a digital signal; A digital signal processing unit, configured to process the digital signal and generate a final output signal and a feedback control signal; A feedback unit, configured to convert the feedback control signal into an analog quantity and feed the analog quantity back to the seismic signal sensitive unit to implement closed-loop control; The timing unit is used to control the alternating sampling of the dual channels and the switching of the circuit states according to the set timing.

2. A MEMS seismic acquisition system based on dual-channel alternating sampling technology according to claim 1, characterized in that: The readout unit includes a storage module, a transducer module, a sampling and holding module and a differential amplifier module according to hardware functions; The readout unit is symmetrically provided with an A path and a B path. The A path and the B path alternately complete the storage, transduction and sampling and holding of the signal under the control of the timing unit, and finally perform differential processing on the signal through the differential amplifier module.

3. A MEMS seismic acquisition system based on dual-channel alternating sampling technology according to claim 2, characterized in that: The A channel includes an A channel in-phase storage module, an A channel inverting storage module, an A channel transducer module and an A channel sampling and holding module, and the B channel includes a B channel in-phase storage module, a B channel inverting storage module, a B channel transducer module and a B channel sampling and holding module; The A-path in-phase storage module is used to store the displacement signal, and the polarity of the stored displacement signal is the same as the output of the seismic signal sensitive unit; The A-path inverting storage module is used to store the displacement signal, and the polarity of the stored displacement signal is opposite to the output of the seismic signal sensitive unit; The B-path in-phase storage module is used to store the displacement signal, and the polarity of the stored displacement signal is the same as the output of the seismic signal sensitive unit; The B-path inverting storage module is used to store the displacement signal, and the polarity of the stored displacement signal is opposite to the output of the seismic signal sensitive unit; The working windows of the A-path in-phase storage module, the A-path inverted storage module, the B-path in-phase storage module, and the B-path inverted storage module are non-overlapping under the control of the timing unit. Between the working windows of the A-path in-phase storage module and the A-path inverted storage module, and the B-path in-phase storage module and the B-path inverted storage module, the reference voltage of the seismic signal sensitive unit is reversed, thereby reversing the polarity of the displacement signal. The A-channel transducer module and the B-channel transducer module are used to convert the displacement signal into the voltage domain with a double amplification factor in a differential manner, and to cancel out noise once by differential operation; The A channel sampling and holding module and the B channel sampling and holding module are used to sample and hold the transduced signal; The differential amplifier module is used to differentially amplify the outputs of the A-channel sampling and holding module and the B-channel sampling and holding module, so as to amplify the signal by two times and cancel out the noise twice by differential operation.

4. A MEMS seismic acquisition system based on dual-channel alternating sampling technology according to claim 3, characterized in that: The working cycle of the readout unit includes the following timing phases: Reset phase, used to ground each node of the circuit; The A channel storage phase and the B channel storage phase are used to store the displacement signals of the A channel and the B channel respectively; A channel signal transduction phase, used to calculate the difference between the displacement signals stored in the A channel in-phase storage module and the A channel inverted phase storage module, and convert the displacement signal into a voltage signal; The B channel signal transduction phase is used to calculate the difference between the displacement signals stored in the B channel in-phase storage module and the B channel inverse-phase storage module, and convert the displacement signal into a voltage signal; The sampling and holding phase of channel A and the sampling and holding phase of channel B respectively sample and hold the transduced signal; The differential amplification phase is used to differentially amplify the outputs of the A-channel sampling and holding module and the B-channel sampling and holding module and output them to the analog-to-digital conversion unit.

5. The MEMS seismic acquisition system based on dual-channel alternating sampling technology according to claim 4, characterized in that: In the A-path storage phase and the B-path storage phase, the polarity of the reference voltage of the seismic signal sensitive unit is reversed once, so as to reverse the polarity of the displacement signal.

6. The MEMS seismic acquisition system based on dual-channel alternating sampling technology according to claim 3, characterized in that: The A-channel energy conversion module and the B-channel energy conversion module both include: The two input terminals of the fully differential operational amplifier are connected to the differential output nodes of the seismic signal sensitive unit in a time-sharing manner under the control of the timing unit.

7. The MEMS seismic acquisition system based on dual-channel alternating sampling technology according to claim 1, characterized in that: The seismic signal sensitive unit is a displacement sensitive MEMS sensor, and the displacement sensitive MEMS sensor at least includes a capacitive, piezoresistive, piezoelectric or optical interference structure.

8. A MEMS seismic acquisition method based on dual-channel alternating sampling technology, based on a MEMS seismic acquisition system based on dual-channel alternating sampling technology according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: Step S1, sensing an external seismic signal through a seismic signal sensitive unit, and outputting a displacement signal corresponding to the seismic signal; Step S2, collecting the displacement signal and noise through the readout unit, and performing noise suppression through a dual-channel alternating sampling method, performing differential amplification on the suppressed output signal, suppressing the noise again and amplifying the effective signal to obtain an analog voltage signal; Step S3, converting the analog voltage signal into a digital signal through an analog-to-digital conversion unit; Step S4, processing the digital signal by a digital signal processing unit to generate a final output signal and a feedback control signal; Step S5: converting the feedback control signal into an analog quantity through a feedback unit and feeding it back to the seismic signal sensitive unit to realize closed-loop control.

9. An electronic device, characterized in that: include: at least one processor; as well as a memory communicatively connected to at least one of the processors; wherein, The memory stores instructions that can be executed by the processor, and the instructions are used to be executed by the processor to implement the MEMS seismic acquisition method based on dual-channel alternating sampling technology as described in claim 8.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer instructions, and the computer instructions are used to be executed by the computer to implement the MEMS seismic acquisition method based on dual-channel alternating sampling technology as described in claim 8.

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