MEMS seismic acquisition system, method and device based on dual-path alternate sampling technology

Abstract

The application belongs to the field of seismic signal acquisition, and particularly relates to a MEMS seismic acquisition system, method and equipment based on a double-path alternating sampling technology, and aims to solve the problem of low system measurement accuracy and reliability. The application comprises: a seismic signal sensitive unit for sensing external seismic signals and outputting corresponding displacement signals; a readout unit for converting the displacement signals into voltage signals and performing noise suppression through a double-path alternating sampling method; an analog-to-digital conversion unit for converting the analog voltage signals into digital signals; a digital signal processing unit for processing the digital signals and generating a final output signal and a feedback control signal; a feedback unit for converting the feedback control signal into an analog quantity and feeding it back to the seismic signal sensitive unit to realize closed-loop control; and a timing unit for controlling the alternating sampling of the double paths and the switching of circuit states according to a set timing. The application realizes multi-stage noise suppression and improves the measurement accuracy.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of seismic signal acquisition, and particularly relates to a MEMS seismic acquisition system, method and device based on a double-path alternating sampling technology. BACKGROUND

[0002] In geological survey and seismic acquisition applications, it is often necessary to continuously and accurately monitor and record extremely weak seismic signals in order to analyze underground structures, stratum changes or source characteristics. The noise level of a seismic acquisition system will directly affect 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, and designing a low-noise readout unit is a prerequisite for implementing a high-precision MEMS seismic acquisition system. The existing readout unit of the MEMS seismic acquisition system mainly consists of a preamplifier, a sample-and-hold circuit, a switching network, a timing unit, etc. The design goal is to convert small displacement changes into voltage signals of sufficient amplitude and to suppress various noises as much as possible in the process. Common noise suppression methods such as chopping stabilization technology, self-stable zero calibration, and correlated double sampling are used to eliminate 1 / f noise and offset voltage. The chopping stabilization technology separates the signal and noise by frequency modulation, and the self-stable zero calibration and correlated double sampling technology use a feedback capacitor to correct the offset in different sampling time slots to achieve the separation of signal and noise.

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

[0005] In addition, many existing designs use a pseudo-differential structure, i.e., using a fixed reference level on one side and signal sampling on the other side to achieve differential processing, but this asymmetric approach can easily cause device mismatching, resulting in additional errors and dynamic imbalance and reducing the overall accuracy of the system.

[0006] To address these problems, it is necessary to improve the circuit structure. By using symmetric double paths and alternating sampling, full-differential signal processing and multi-stage noise suppression are achieved, thereby improving the measurement accuracy and reliability of the MEMS seismic acquisition system. SUMMARY

[0007] To solve the above problems in the prior art, i.e., the single-path readout unit of the existing MEMS seismic acquisition system has insufficient noise suppression capability (such as the inability to eliminate switching noise) and device mismatching due to the pseudo-differential structure, resulting in reduced measurement accuracy and reliability of the system, the present application provides a MEMS seismic acquisition system, method and device based on a double-path 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:

[0009] Seismic signal sensitive unit, used to sense external seismic signals and output corresponding displacement signals;

[0010] a readout unit, configured to convert the displacement signal into a voltage signal and perform noise suppression through a dual-channel alternating sampling method;

[0011] an analog-to-digital conversion unit, configured to convert an analog voltage signal into a digital signal;

[0012] A digital signal processing unit, configured to process the digital signal and generate a final output signal and a feedback control signal;

[0013] 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;

[0014] 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.

[0015] 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;

[0016] 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.

[0017] 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;

[0018] 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;

[0019] 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;

[0020] 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;

[0021] 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;

[0022] The working windows of the A-path in-phase storage module, the A-path anti-phase storage module, the B-path in-phase storage module and the B-path anti-phase storage module are non-overlapped under the control of the timing unit, and the reference voltage of the seismic signal sensing unit is reversed between the working windows of the A-path in-phase storage module and the A-path anti-phase storage module and the working windows of the B-path in-phase storage module and the B-path anti-phase storage module, so that the polarity of the displacement signal is reversed, and since the working frequency of the readout unit is much greater than the noise bandwidth, the noise stored in the in-phase storage module and the anti-phase storage module at the same time as the signal can be considered approximately equal;

[0023] The A-path transduction module and the B-path transduction module are configured to transduce the displacement signal to the voltage domain in a differential manner with a two-fold amplification factor, and offset the noise once by differential operation;

[0024] The A-path sampling and holding module and the B-path sampling and holding module are configured to sample and hold the transduced signal;

[0025] The differential amplification module is configured to differentially amplify the outputs of the A-path sampling and holding module and the B-path sampling and holding module, so that the signal is amplified again by two times and the noise is offset twice by differential operation, and the noise is further reduced to a negligible high-order small amount.

[0026] Further, the working cycle of the readout unit includes the following timing phases:

[0027] The reset phase is configured to ground each node of the circuit;

[0028] The A-path storage phase and the B-path storage phase are configured to store the displacement signals of the A-path and the B-path, respectively;

[0029] The A-path signal transduction phase is configured to calculate the difference between the displacement signals stored in the A-path in-phase storage module and the A-path anti-phase storage module, and convert the displacement signal into a voltage signal;

[0030] The B-path signal transduction phase is configured to calculate the difference between the displacement signals stored in the B-path in-phase storage module and the B-path anti-phase storage module, and convert the displacement signal into a voltage signal;

[0031] The A-path sampling and holding phase and the B-path sampling and holding phase are configured to sample and hold the transduced signal, respectively;

[0032] The differential amplification phase is configured to differentially amplify the outputs of the A-path sampling and holding module and the B-path sampling and holding module and output to the analog-to-digital conversion unit.

[0033] Further, in the A-path storage phase and the B-path storage phase, the reference voltage polarity of the seismic signal sensing unit is reversed once to reverse the polarity of the displacement signal.

[0034] Further, the A-path transduction module and the B-path transduction module each include:

[0035] A fully differential operational amplifier, two input terminals of which are connected to the differential output nodes of the seismic signal sensing unit under the control of the timing unit.

[0036] Further, the seismic signal sensing unit is a displacement-sensitive MEMS sensor, which at least includes a capacitive, piezoresistive, piezoelectric or optical interference structure.

[0037] In a second aspect, the application provides a MEMS seismic acquisition method based on a dual-path alternating sampling technology, based on a MEMS seismic acquisition system based on a dual-path alternating sampling technology, the method comprising the following steps:

[0038] Step S1, sensing an external seismic signal by a seismic signal sensing unit, and outputting a displacement signal corresponding to the seismic signal;

[0039] Step S2, acquiring the displacement signal and noise by a readout unit, suppressing noise by a dual-path alternating sampling method, differentially amplifying the output signal after suppression, suppressing noise again and amplifying the effective signal to obtain an analog voltage signal;

[0040] Step S3, converting the analog voltage signal into a digital signal by an analog-to-digital conversion unit;

[0041] Step S4, processing the digital signal by a digital signal processing unit to generate a final output signal and a feedback control signal;

[0042] Step S5, converting the feedback control signal into an analog quantity by a feedback unit, and feeding it back to the seismic signal sensing unit to realize closed-loop control.

[0043] In a third aspect, the application provides an electronic device, comprising:

[0044] at least one processor; and

[0045] a memory in communication connection with the at least one processor; wherein,

[0046] The memory stores instructions executable by the processor, and the instructions are used to be executed by the processor to realize a MEMS seismic acquisition method based on a dual-path alternating sampling technology.

[0047] In a fourth aspect, the application provides a computer readable storage medium storing computer instructions for being executed by a computer to implement a MEMS seismic acquisition method based on a dual-channel alternate sampling technology.

[0048] Advantages of the application:

[0049] Elimination of switching noise: through the dual-channel alternate sampling technology, time-interleaved signal acquisition and processing are realized on the symmetric two-channel signal paths, so that the switching noise such as charge injection and clock feedthrough is canceled as a common-mode component in the two-channel differential output, and the problem of noise superposition in single-channel sampling is significantly suppressed.

[0050] Solving the mismatch error of pseudo-differential structure: the symmetric dual-channel fully differential signal processing architecture is adopted, and the fixed reference level design is abandoned, so that the two signal paths are completely symmetric, the dynamic imbalance and additional mismatch error caused by device mismatch are eliminated from the circuit structure, and the system precision is improved.

[0051] Multi-stage noise suppression capability: combined with the fully differential signal processing and the alternate sampling mechanism, the suppression of noise residual is realized in the signal path, directly aiming at the defect of insufficient noise suppression of single-channel readout unit in the background technology, and the weak signal analysis capability is enhanced. BRIEF DESCRIPTION OF DRAWINGS

[0052] Other features, objects and advantages of the application will become more apparent from the following detailed description of non-limiting embodiments made with reference to the accompanying drawings:

[0053] Figure 1 A block diagram of a MEMS seismic acquisition system based on a dual-channel alternate sampling technology of the application;

[0054] Figure 2 A specific implementation circuit of a readout unit of an embodiment of the application;

[0055] Figure 3 A working state schematic diagram of the specific implementation circuit of the readout unit of the embodiment of the application in a reset phase;

[0056] Figure 4 A working state schematic diagram of the specific implementation circuit of the readout unit of the embodiment of the application in an A-channel storage phase;

[0057] Figure 5 A working state schematic diagram of the specific implementation circuit of the readout unit of the embodiment of the application in an A-channel signal transduction phase;

[0058] Figure 6 A working state schematic diagram of the specific implementation circuit of the readout unit of the embodiment of the application in an A-channel sampling and holding phase;

[0059] Figure 7 The working state diagram of the readout unit of the embodiment of the application for storing the phase of the B channel is shown in the figure below.

[0060] Figure 8 The working state diagram of the readout unit of the embodiment of the application for transducing the phase of the signal of the B channel is shown in the figure below.

[0061] Figure 9 The working state diagram of the readout unit of the embodiment of the application for sampling and holding the phase of the B channel is shown in the figure below.

[0062] Figure 10 The working state diagram of the readout unit of the embodiment of the application for differential amplification is shown in the figure below.

[0063] Figure 11 The diagram of the switch state and timing of the readout unit of the embodiment of the application is shown in the figure below. DETAILED DESCRIPTION

[0064] The application will be further described below in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the related application, and not to limit the application. In addition, it should be noted that only the parts related to the application are shown in the drawings for ease of description.

[0065] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0066] The application provides a MEMS seismic acquisition system based on a double-channel alternating sampling technology, which comprises:

[0067] A seismic signal sensing unit is configured to sense external seismic signals and output corresponding displacement signals.

[0068] A readout unit is configured to convert the displacement signals into voltage signals and suppress noise by means of a double-channel alternating sampling method.

[0069] An analog-to-digital conversion unit is configured to convert analog voltage signals into digital signals.

[0070] A digital signal processing unit is configured to process the digital signals and generate a final output signal and a feedback control signal.

[0071] A feedback unit is configured to convert the feedback control signal into an analog quantity and feed it back to the seismic signal sensing unit to realize closed-loop control.

[0072] Timing unit, for controlling the switching of the circuit state and the alternate sampling of the double channel according to the set timing.

[0073] The working principle of the present application is as follows: the seismic signal sensing 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 the final output signal and the feedback control signal required, and completes 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 sensing unit to realize real-time adjustment of the seismic sensing unit and complete closed-loop control.

[0074] In order to more clearly illustrate the MEMS seismic acquisition system based on the double-channel alternate sampling technology of the present application, the following will be combined with Figure 1 The present application will be described in detail, and the detailed description is as follows:

[0075] The seismic signal sensing unit is used for sensing the external seismic signal and outputting the corresponding displacement signal.

[0076] The input end of the seismic signal sensing unit is connected to the output end of the feedback unit, and the output end of the seismic signal sensing unit is connected to the input end of the readout unit.

[0077] The seismic signal sensing unit is a displacement sensitive MEMS sensor, which includes but is not limited to a capacitive, piezoresistive, piezoelectric or optical interference structure. In this embodiment, a MEMS capacitive sensor is preferred.

[0078] The readout unit is used for converting the displacement signal into a voltage signal and suppressing noise by the double-channel alternate sampling method.

[0079] The readout unit includes two input ends connected to the output ends of the seismic signal sensing unit and the timing unit, respectively, the output end of the readout unit is connected to the input end of the analog-to-digital conversion unit, the output end of the analog-to-digital conversion unit is connected to the input end of the digital signal processing unit, the digital signal processing unit is provided with two output ends, one of which is used for outputting a signal, and the other is connected to the input end of the feedback unit, and the output end of the feedback unit is connected to the input end of the seismic signal sensing unit.

[0080] Preferably, the readout unit is composed of a capacitance-voltage readout circuit.

[0081] The readout unit comprises a transduction module, a sample and hold module and a differential amplification module in terms of hardware functions.

[0082] The A channel comprises an A channel in-phase storage module, an A channel inverse-phase storage module, an A channel transduction module and an A channel sample and hold module, and the B channel comprises a B channel in-phase storage module, a B channel inverse-phase storage module, a B channel transduction module and a B channel sample and hold module.

[0083] The A channel in-phase storage module is configured to store the displacement signal, and the stored displacement signal has the same polarity as the output of the seismic signal sensing unit.

[0084] The A channel inverse-phase storage module is configured to store the displacement signal, and the stored displacement signal has the opposite polarity to the output of the seismic signal sensing unit.

[0085] The B channel in-phase storage module is configured to store the displacement signal, and the stored displacement signal has the same polarity as the output of the seismic signal sensing unit.

[0086] The B channel inverse-phase storage module is configured to store the displacement signal, and the stored displacement signal has the opposite polarity to the output of the seismic signal sensing unit.

[0087] The working windows of the A channel in-phase storage module, the A channel inverse-phase storage module, the B channel in-phase storage module and the B channel inverse-phase storage module are non-overlapping under the control of the timing unit, and the reference voltage of the seismic signal sensing unit is reversed between the working windows of the A channel in-phase storage module and the A channel inverse-phase storage module and between the working windows of the B channel in-phase storage module and the B channel inverse-phase storage module, so that the polarity of the displacement signal is reversed.

[0088] The A channel transduction module and the B channel transduction module are configured to transduce the displacement signal to the voltage domain in a differential manner with a doubled amplification factor, and offset noise once by differential operation.

[0089] The A channel sample and hold module and the B channel sample and hold module are configured to sample and hold the transduced signal.

[0090] The differential amplification module is configured to differentially amplify the outputs of the A channel sample and hold module and the B channel sample and hold module and offset noise twice by differential operation.

[0091] The A channel and the B channel of the readout unit work alternately, and in one cycle, the signal and the noise are collected twice, the signal transduction, amplification and noise cancellation are completed, then the signal and the noise residual are sampled and stored in the respective sampling capacitors, finally, the noise residual is further reduced to a negligible high-order small amount through the differential amplification module, and the signal is amplified twice.

[0092] The output end of the timing unit is connected to the input end of the readout unit; and the timing unit is used for controlling the alternate sampling and circuit state switching of the A channel and the B channel according to a preset timing.

[0093] Preferably, the timing unit is composed of a crystal oscillator, a phase-locked loop and a corresponding digital logic circuit.

[0094] One working cycle of the readout unit includes the following timing phases:

[0095] A reset phase (phreset) for grounding each node of the circuit;

[0096] An A channel storage phase (phAsave) and a B channel storage phase (phBsave) for respectively storing the displacement signals of the A channel and the B channel;

[0097] An A channel signal transduction phase (phAtrans) for calculating the difference between the displacement signals stored in the A channel same-phase storage module and the A channel opposite-phase storage module, and converting the displacement signals into voltage signals;

[0098] A B channel signal transduction phase (phBtrans) for calculating the difference between the displacement signals stored in the B channel same-phase storage module and the B channel opposite-phase storage module, and converting the displacement signals into voltage signals;

[0099] An A channel sampling and holding phase (phAsh) and a B channel sampling and holding phase (phBsh) for respectively sampling and holding the transduced signals;

[0100] A differential amplification phase (phdiff) for differentially amplifying the outputs of the A channel sampling and holding module and the B channel sampling and holding module.

[0101] In the A channel storage phase and the B channel storage phase, the polarity of the reference voltage of the seismic signal sensing unit is reversed once, for reversing the polarity of the displacement signals.

[0102] The A channel transduction module and the B channel transduction module each include:

[0103] A fully differential operational amplifier, whose two input ends are connected to the differential output nodes of the seismic signal sensing unit in time under the control of the timing unit.

[0104] The equivalent voltage signal of the output node of the in-phase storage module of the A and B paths in the storage phase is:

[0105]

[0106]

[0107] The equivalent voltage signal of the output node of the anti-phase storage module of the A and B paths in the storage phase is:

[0108]

[0109]

[0110] The output voltage of the transduction module of the A and B paths is obtained by differentially processing the equivalent voltage signals of the output nodes of the in-phase storage module and the anti-phase storage module of the A and B paths in the signal transduction phase, and the voltage will be sampled and held by the sampling and holding modules of the A and B paths for subsequent processing by the differential amplification module.

[0111]

[0112]

[0113] The output voltage of the sampling and holding module in the sampling and holding phase is:

[0114]

[0115]

[0116] The output voltage of the differential amplification module in the differential amplification phase is:

[0117]

[0118] Since the working frequency of the system readout unit is much higher than the noise bandwidth, the noise stored by the in-phase storage module and the anti-phase storage module can be approximately considered as:

[0119]

[0120]

[0121] After differential processing in the signal transduction phase, the noise is approximately canceled, leaving only the noise residual and :

[0122]

[0123] ;​​​​​​​​​​​​

[0124] After passing through the differential amplification module, the noise residual and Again, the final remaining noise is a small amount of high order , which can be ignored compared to the measured signal:

[0125]

[0126] In the above formula, represents the equivalent voltage signal of the measured signal, and the 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 A or B path, and the physical dimension of the noise 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 equivalent voltage signal of the output node of A or B path, in-phase storage module or anti-phase storage module, which contains the equivalent voltage signal of the measured signal and noise, and the 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 the first difference; represents the noise high order small amount after the second difference.

[0127] As Figure 2 shown, the specific implementation circuit of the readout unit of the application includes a MEMS seismic signal sensitive unit equivalent differential capacitor 1, an A path CV readout circuit 2, an A path feedback capacitor 3, a B path CV readout circuit 4, a B path feedback capacitor 5, an A path sample and hold circuit 6, a B path sample and hold circuit 7, a full differential operational amplifier 8, and a differential amplification circuit 9.

[0128] Among them, CV readout circuit represents a capacitance-voltage readout circuit.

[0129] In the illustrated circuit, the symbol Φxxx represents a corresponding analog switch, and each Φxxx has only two states of "on" or "off in logic, which is used to switch the circuit state at different phases; further, in Figure 11 , high level represents switch on, and low level represents switch off.

[0130] V P represents a positive reference voltage; V N represents a negative reference voltage; GND represents a system zero potential reference; C FB represents a feedback capacitor; C HA represents an A path sampling and holding capacitor; C HB ​The sampling holding capacitor of the B channel; V OUTA The output voltage of the A channel; V OUTB The output voltage of the B channel; V OUT The output voltage of the differential amplification module.

[0131] Under the control of the timing unit, the specific implementation circuit of the readout unit of the application will be in the following working states:

[0132] Figure 3 For the timing unit in the reset phase, the circuit working state diagram, in this state, the circuit nodes are grounded, the capacitors are cleared, and the circuit output is zero.

[0133] ;

[0134] Figure 4 For the timing unit in the A channel storage phase, the circuit working state diagram, 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 the negative voltage V N , the input of the A channel is connected to the middle plate of the equivalent differential capacitor of the MEMS seismic signal sensitive unit, the feedback capacitor of the A channel stores the noise of the circuit, the sampling and holding circuits of the A and B channels are disconnected from the CV readout circuits, and the nodes of the CV readout circuit of the B channel remain grounded.

[0135] Figure 5 For the timing unit in the A channel signal transduction phase, the circuit working state diagram, 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 the A channel is connected to the middle plate of the equivalent differential capacitor of the MEMS seismic signal sensitive unit, and the feedback capacitor of the A channel is connected to the negative input terminal of the full differential operational amplifier, converting the changing capacitor signal into a voltage signal.

[0136] Figure 6 For the timing unit in the A channel sampling and holding phase, the circuit working state diagram, in this state, the A channel sampling and holding circuit will sample the output voltage of the CV readout circuit of the channel.

[0137] ;

[0138] Where, V outA The output voltage of the A channel sampling and holding module; C T The capacitance between the upper and middle plates of the equivalent differential capacitor of the seismic signal sensitive unit; C B The capacitance between the lower and middle plates of the equivalent differential capacitor of the seismic signal sensitive unit; CFB represents feedback capacitor; V P represents positive reference voltage; V N represents negative reference voltage; represents A channel noise residual.

[0139] Figure 7 As timing unit is in B channel storage phase, the circuit working state diagram, in this state, A channel sampling and holding circuit is first disconnected with A channel CV readout circuit, holding the A channel output voltage collected in the last working state, then the rest of the A channel nodes will be grounded. MEMS seismic signal sensitive unit equivalent differential capacitor upper plate connects negative voltage V N , the lower plate connects positive voltage V P , B channel input is connected with the middle plate of MEMS seismic signal sensitive unit equivalent differential capacitor, B channel feedback capacitor storage circuit noise.

[0140] Figure 8 As timing unit is in B channel signal transduction phase, the circuit working state diagram, in this state, the upper plate of MEMS seismic signal sensitive unit equivalent differential capacitor connects positive voltage V P , the lower plate connects negative voltage V N , B channel input is connected with the middle plate of MEMS seismic signal sensitive unit equivalent differential capacitor, B channel feedback capacitor is connected with the positive input terminal of full differential operational amplifier, and the changing capacitor signal is converted into voltage signal.

[0141] Figure 9 As timing unit is in B channel sampling and holding phase, the circuit working state diagram, in this state, B channel sampling and holding circuit will sample the output voltage of CV readout circuit of the channel, and all nodes of A channel except sampling and holding capacitor are kept grounded.

[0142] ;

[0143] wherein, V outB represents the output voltage of B channel sampling and holding module; represents B channel noise residual.

[0144] Figure 10 As timing unit is in differential amplification phase, the circuit working state diagram, in this state, the sampling and holding circuits of A and B channels are connected with the two inputs of differential amplification circuit, and the differential amplification circuit will find the difference between the outputs of A and B channels to obtain the final output voltage of readout unit:

[0145] .

[0146] The feedback capacitor is configured to match the equivalent differential capacitor.

[0147] The feedback unit includes a digital-to-analog converter and a driving circuit for converting a digital feedback signal into an analog driving voltage and applying it to a driving mechanism of the seismic signal sensing unit.

[0148] The seismic signal sensing unit has an equivalent differential capacitor, and the middle stage plate of the equivalent differential capacitor is connected to the input ends of the A-path and B-path transduction modules.

[0149] It should be noted that the above embodiment provides a MEMS seismic acquisition system based on a dual-path alternating sampling technology, and only the division of the above functional modules is exemplified, and in actual application, the above functions can be completed by different functional modules according to needs, that is, the modules or steps in the embodiment of the application are further decomposed or combined, for example, the modules of the above embodiment can be combined into one module, or can be further split 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 application are only for distinguishing the modules and steps, and should not be considered as an improper limitation of the application.

[0150] The second embodiment of the application provides a MEMS seismic acquisition method based on a dual-path alternating sampling technology, based on a MEMS seismic acquisition system based on a dual-path alternating sampling technology, and the method includes the following steps:

[0151] Step S1, sensing an external seismic signal by a seismic signal sensing unit, and outputting a displacement signal corresponding to the seismic signal;

[0152] Step S2, acquiring the displacement signal and noise by a readout unit, suppressing noise by a dual-path alternating sampling method, differentially amplifying the output signal after suppression, suppressing noise again and amplifying the effective signal, and obtaining an analog voltage signal;

[0153] Step S3, converting the analog voltage signal into a digital signal by an analog-to-digital conversion unit;

[0154] Step S4, processing the digital signal by a digital signal processing unit to generate a final output signal and a feedback control signal;

[0155] Step S5, converting the feedback control signal into an analog quantity by a feedback unit, and feeding it back to the seismic signal sensing unit to realize closed-loop control.

[0156] Although the steps are described in the above-mentioned order in the above-mentioned embodiments, it can be understood by those skilled in the art that, in order to achieve the effects of the embodiments, the different steps do not have to be executed in such an order, and can be executed simultaneously (in parallel) or in a reversed order, and these simple changes are within the protection scope of the present application.

[0157] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes and related descriptions of the above-described method can refer to the corresponding processes in the foregoing method embodiments, which will not be described here.

[0158] The electronic device of the third embodiment of the present application comprises:

[0159] at least one processor; and

[0160] a memory in communication connection with the at least one processor; wherein

[0161] The memory stores instructions executable by the processor, and the instructions are used to be executed by the processor to implement the MEMS seismic acquisition method based on the double-channel alternating sampling technology.

[0162] The computer readable storage medium of the fourth embodiment of the present application stores computer instructions, and the computer instructions are used to be executed by the computer to implement the MEMS seismic acquisition method based on the double-channel alternating sampling technology.

[0163] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes and related descriptions of the above-described storage device and processing device can refer to the corresponding processes in the foregoing method embodiments, which will not be described here.

[0164] Those skilled in the art should appreciate that the modules and method steps of each example described in connection with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. The software modules, method steps corresponding to the program can be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. In order to clearly illustrate the interchangeability of electronic hardware and software, the components and steps of each example have been generally described in the above description. Whether the 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 can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0165] The terms "first", "second", etc. are used to distinguish similar objects, rather than to describe or indicate a particular order or sequence.

[0166] The term "comprising" or any other similar term is intended to encompass the inclusion of non-exclusive inclusion, so that the process, method, article or equipment / device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes elements inherent to the process, method, article or equipment / device.

[0167] So far, the technical solutions of the present application have been described in combination with the preferred embodiments shown in the drawings, but it is easy for those skilled in the art to understand that the protection scope of the present application is obviously not limited to these specific embodiments. Those skilled in the art can make equivalent changes or replacements to the related technical features without departing from the principles of the present application, and the technical solutions after the changes or replacements will all fall within the protection scope of the present application.

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; 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; 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 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.

3. A MEMS seismic acquisition system based on dual-channel alternating sampling technology according to claim 2, 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.

4. A MEMS seismic acquisition system based on dual-channel alternating sampling technology according to claim 3, 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.

5. The MEMS seismic acquisition system based on dual-channel alternating sampling technology according to claim 2, 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.

6. 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.

7. 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 6, 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.

8. 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 7.

9. 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 7.

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