75 results about "Low frequency response" patented technology

The utility model relates to the technical field of sound boxes, in particular to an improved sound box, which comprises a box body and a front cover fixedly mounted on one side of the box body, a loudspeaker is fixedly arranged at the center of the inner side of the front cover, a small loudspeaker is fixedly arranged at the upper end of the inner side of the front cover, and a connecting block is fixedly arranged at the concentric position of the center of the outer side of the front cover and the loudspeaker. U-shaped blocks used for protecting the loudspeaker are symmetrically arranged in the connecting block up and down, damage of an external object to a vibrating diaphragm of the loudspeaker is prevented, the service life of the loudspeaker is prolonged, the U-shaped blocks can also be used as handles, a user can conveniently carry the loudspeaker box, and practicability is improved; the supporting plate is arranged in the annular groove, so that the structural strength is enhanced, the front cover is prevented from being deformed when being stressed, the resonance phenomenon in the annular groove is reduced, the overall tone quality performance of the sound box is improved, the sealing gasket ensures the tight attachment between the front cover and the box body, air leakage is prevented, and the low-frequency response and the overall tone quality clarity are improved.

The invention relates to the technical field of improvement of electroacoustic devices, and discloses a sound guide method for a non-in-ear earphone and a sound guide accessory thereof, and the method comprises the steps: collecting the spatial parameters of the earphone and an ear canal; the optimal gathering angle theta opt is calculated through the sound energy gathering angle optimization model, the sound guide path shape is optimized through the path loss minimization model so as to minimize Lpath, and finally sound guide accessories are manufactured and installed; the fitting comprises an adaptive interface part, an acoustic gathering part and a flexible sound conducting part, directional gathering and efficient conduction of sound energy are accurately controlled through a mathematical model, and on the premise that the non-in-ear earphone is kept painless and comfortable to wear, low-frequency response is remarkably improved, sound leakage is reduced, and sound quality details are improved; the technical contradiction between the poor tone quality of an open earphone and the strong discomfort of an in-ear earphone is effectively solved; the scheme is simple in structure, can be used as a universal accessory or integrally designed, and has wide applicability.

A method for optimizing acoustic performance in listening spaces addresses limitations in room acoustics for music production and reproduction. The method comprises two optimization steps: a multi-objective room optimization method applicable to any room shape and a multi-objective treatment optimization method that iteratively searches a library of potential acoustical treatments to determine optimal solutions for each accessible area. The method utilizes a multi-objective search engine to simultaneously optimize several critical acoustic metrics, including low-frequency response, spatial variation around listening positions, early reflections, modal temporal decay, and mid-to-high-frequency reverberation time. The integration of both optimization methods provides comprehensive acoustic control across the entire audible spectrum.

The utility model discloses a high-performance loudspeaker, which relates to the technical field of loudspeakers, comprises a loudspeaker box, and a voice coil, a magnetic group and a membrane group which are arranged in the loudspeaker box, and is characterized in that an accommodating space is arranged in the magnetic group, the accommodating space is communicated with the external space of the loudspeaker box, a passive radiator is arranged in the accommodating space, and the membrane group is communicated with the passive radiator. The passive radiator comprises a passive radiation mass block and a passive radiation vibrating diaphragm arranged on the periphery of the passive radiation mass block, and the passive radiation vibrating diaphragm is connected with the magnetic group. According to the utility model, through the structure of the magnetic circuit and the passive radiator, the performance of the loudspeaker is improved, and under the condition of the same rear cavity space, the loudspeaker has lower resonant frequency, better low-frequency response and larger sound radiation area, and can provide more loud sound.

According to the sound equipment system provided by the utility model, by optimizing the structural design of the sound equipment, the sound quality effect of the sound equipment is ensured, and meanwhile, the standard packaging size requirement is met. Firstly, the length of the bar-shaped sound box is controlled within 400mm, and the width and the height of the bar-shaped sound box do not exceed 90mm, so that the bar-shaped sound box can adapt to a compact packaging design, and sound channel arrangement and a sound field coverage range are not influenced. And secondly, the size of the bass sound box is limited within 400mm * 300mm * 150mm, so that the volume is reduced, enough low-frequency response can still be provided, and the requirement of a user on a bass effect is met. The size of the outer packaging box provided by the invention accords with the international general standard package size, so that the logistics transportation cost is reduced, and the storage and distribution efficiency is improved. Meanwhile, the structural design avoids the problem that a traditional sound box product needs to be packaged in a special shape due to the fact that the size is too large, not only is the universality of packaging improved, but also the market competitiveness is enhanced, and the product is convenient to sell and circulate in the global range.

The utility model discloses a parallel module with double independent front cavities, which relates to the technical field of loudspeakers and comprises an upper loudspeaker, a lower loudspeaker and a front cavity channel, the front cavity channel is arranged between the lower loudspeaker and the upper loudspeaker, and a front cavity isolation plate is arranged between the upper loudspeaker and the lower loudspeaker. The front cavity isolation plate, the upper loudspeaker and the lower loudspeaker are all connected with the peripheral supporting piece. According to the parallel module with the double independent front cavities, the front cavity channel is divided into the two independent cavities through the arrangement of the front cavity isolation plate, sound wave interference is eliminated, distortion is reduced, and the independent front cavities isolate vibration of the vibrating diaphragm, so that the problem of phase loss resonance distortion is effectively solved; the upper loudspeaker and the lower loudspeaker are arranged in parallel, so that the problem of insufficient sound pressure of small equipment is effectively solved, and the low-frequency response and the overall volume are remarkably enhanced; through the arrangement of the lower loudspeaker, the problem of weak low-frequency sound is effectively improved, and the low-frequency depth and elasticity are improved.

The invention belongs to the technical field of MEMS loudspeakers, and particularly relates to a preparation method of a PZT loudspeaker based on a back guide structure. Comprising the steps that a bottom electrode metal film and a PZT piezoelectric film are sequentially sputtered on the front face of a device at high temperature through a magnetron sputtering PVD technology; performing a bottom electrode layer structure photoetching process; performing a top electrode layer photoetching process; performing an upper and lower electrode isolation layer photoetching process, performing a front surface back guide hole structure photoetching process, and etching a top silicon layer of the SOI substrate material sheet through ICP (Inductively Coupled Plasma) to form a device back guide hole structure; depositing a Parylene protection material on the front side by a vacuum vapor deposition process; and performing a back photoetching process, and etching the back of the SOI substrate material sheet through ICP (Inductively Coupled Plasma) to form a device diaphragm cavity structure. According to the invention, the air circulation resistance of the rear cavity can be accurately controlled, the quality-spring property of the diaphragm can be matched, the rigidity and damping of the diaphragm can be balanced, the resonance peak can be effectively reduced, the low-frequency response bandwidth can be expanded, and the SPL can be improved.

The application discloses a MEMS loudspeaker device, system and preparation method driven by electrostatic and piezoelectric mixed driving, relates to the technical field of loudspeakers, and aims at solving the problems of high driving voltage, easy occurrence of suction effect and insufficient low-frequency response caused by single electrostatic driving mode of the prior art, and the problem of poor high-frequency response caused by single piezoelectric driving. The MEMS loudspeaker device comprises, from bottom to top, a substrate, an electrostatic driving unit formed on the substrate, at least a fixed electrode and a movable diaphragm of the electrostatic driving unit, and a piezoelectric driving unit integrated on the movable diaphragm. The piezoelectric driving unit receives a preset direct-current bias voltage of a preset size to control the movable diaphragm to generate a preset static displacement in the direction of the fixed electrode, and the piezoelectric driving unit processes middle-low frequency signals in input wide-band audio signals; the electrostatic driving unit processes high frequency signals in the wide-band audio signals. The application is used for improving loudspeaker quality of the loudspeaker and reducing power consumption.

The utility model belongs to the field of teaching conference consonants, particularly relates to a flat-panel sound box adopting an aluminum honeycomb double-surface vibration sound production board, and aims to solve the problems that in the prior art, in order to improve low-frequency response, a wave or honeycomb sandwich layer double-surface paperboard is generally adopted as a sound production surface, so that transient response is reduced, sound is not transparent enough, and the reduction degree is poor. According to the technical scheme, the sound box comprises a sound box body, the sound box body comprises a flat-panel sound box frame body, an aluminum honeycomb double-surface vibration sound production plate and a sound box back plate, the aluminum honeycomb double-surface vibration sound production plate and the sound box back plate are arranged on the two sides in the flat-panel sound box frame body respectively, and a driver is installed on the side, located in the flat-panel sound box frame body, of the aluminum honeycomb double-surface vibration sound production plate; an existing paper sandwich panel is replaced by the aluminum honeycomb double-surface vibration sound production plate, so that medium-high frequency extension of the loudspeaker can be expanded, a transparent and pure sound production effect is generated, and the loudspeaker has very high pressure resistance, and can effectively prevent deformation, moisture and mildew.

The application provides a semi-submersible platform air gap extreme value prediction system and method based on numerical simulation, relates to the technical field of numerical simulation, and obtains an air gap response sequence of a semi-submersible platform in a target water area through numerical simulation; extracts a low-frequency response from the air gap response sequence, carries out nonlinear correction on the low-frequency response based on a data-driven model, and obtains a corrected low-frequency response sequence; reconstructs the corrected low-frequency response sequence and a wave frequency response to obtain a composite air gap response sequence; carries out non-Gaussian extreme value statistics based on the composite air gap response sequence to obtain an air gap extreme value prediction result; and then obtains a test sequence of the air gap of the semi-submersible platform changing with time, and iteratively optimizes the data-driven model based on the difference between the test sequence and the air gap extreme value prediction result, so that the application can realize data-driven accurate correction of the low-frequency response in numerical simulation, and improve the air gap extreme value prediction accuracy of the semi-submersible platform.

The invention relates to the technical field of force sensors, and discloses a six-dimensional force sensor comprising a mounting seat; the cover plate can rotate around a first direction and a second direction relative to the inner core to drive the inner core to rotate around a third direction and move along the first direction, the second direction and the third direction; a first rotary connection assembly; the first tangential force sensitive core body is used for detecting a first tangential force; a second rotary connection assembly; the second tangential force sensitive core body is used for detecting a second tangential force; the third tangential force sensitive core body is used for detecting a third tangential force; the force transmission piece is arranged on the inner core in a sleeving manner; the first direction force sensitive core body is used for detecting a first acting force; the second direction force sensitive core body is used for detecting a second acting force; the second force transmission piece is fixed on the movable piece; and the third direction force sensitive core body detects the third acting force. According to the six-dimensional force sensor disclosed by the invention, the defects of low detection precision, poor creep resistance, low frequency response and remarkable temperature drift of a strain gauge type six-dimensional force sensor are improved.

The utility model discloses a single shell bone conduction MEMS microphone structure belongs to bone conduction MEMS microphone technical field. A single shell bone conduction MEMS microphone structure, including shell and PCB, the shell is installed at the top of PCB, and the bottom of PCB is provided with PAD, the outer surface of PCB is provided with MEMS, one side of MEMS is provided with ASIC, wherein, ASIC is connected with MEMS and PCB through gold wire respectively. To solve the existing bone conduction MEMS microphone when receiving the broadcast is susceptible to external air pressure, thereby appearing the problem of resonance peak, and the diaphragm appears the tailing effect, finally leads the problem of voice fuzzy, the inner air vent solves the static pressure balance problem, protects the diaphragm and guarantees long -term stability, and the design of the air vent of extending to the support ring and mass block gap, through the accurate control of air release, can optimize the low frequency response, and suppress unnecessary resonance peak.

The invention relates to a low-frequency response test method for a lithium niobate phase modulator based on a fiber-optic gyroscope, belongs to the technical field of fiber-optic gyroscopes, and solves the problem that the frequency response of the lithium niobate phase modulator at the low frequency is difficult to measure in the prior art. A digital quantity corresponding to the 2pi phase voltage of the lithium niobate phase modulator; s2, setting the fiber-optic gyroscope under a static and open-loop working condition; s3, the multiple fixed step waves and the bias modulation signals are applied to the lithium niobate phase modulator, and the fixed step waves correspond to different phase modulator modulation frequencies; s4, calculating to obtain an ideal phase difference; the actual phase difference is measured; and S5, comparing the ideal phase difference with the actual phase difference to obtain an electro-optical response characteristic of the lithium niobate phase modulator under a low-frequency condition, and taking the electro-optical response characteristic as a test result.

The technique for operating a loudspeaker disposed within a sealed housing, executed by a data processing system, includes: obtaining a first input signal to be output by the loudspeaker; determining a first volume level associated with the first input signal; selecting a first Linkwitz transform and a first multi-band compressor (MBDRC) from volume-related configuration data based on the first volume level; generating a first intermediate signal to improve the low-frequency response of the loudspeaker by applying the first Linkwitz transform to the first input signal; applying the first MBDRC to the first intermediate signal to generate a first output signal by compressing at least a portion of the first intermediate signal; and driving the loudspeaker using the first output signal to produce a first audio output.

The invention relates to the technical field of optoelectronic device modeling, in particular to a thin film lithium niobate phase modulator low-frequency response analysis method which comprises the steps that equivalent RC branches are established for an upper cladding layer, a lithium niobate waveguide layer and a substrate layer of a thin film lithium niobate phase modulator respectively, and an RC network structure is established through the equivalent RC branches; extracting the structure and electrical parameters of the thin film lithium niobate phase modulator and determining the initial value of an RC element in the RC network structure; determining a node voltage state model based on the RC network structure, solving the node voltage state model, and obtaining system response; based on the system response and the RC network structure, effective voltage, characteristic relaxation time and low-frequency drift amplitude are determined to serve as low-frequency response of the thin-film lithium niobate phase modulator; according to the invention, corresponding physical interpretability analysis of the device can be realized.

The application discloses a kind of based on three-stage cooperation of transmission and distribution self-adapting power grid low-frequency load shedding method and device, the method is by constructing wide-area measurement network when detecting low-frequency overrun, collection synchronous operation data, constructs multi-machine equivalent model, calculates initial total power shortage;Draw low-frequency response curve, calculate real-time frequency change rate, according to new energy access proportion judgment threshold interval, correct or directly adopt initial shortage value;According to accurate shortage value, by equal distribution algorithm is decomposed into distribution network partition load shedding and is issued, distribution network is again decomposed to district internet of things terminal;Terminal screening cuts off the non-important load of small frequency regulation effect, feedback actual cut-off amount;Transmission network dispatching center accumulates cumulative load shedding, judges whether frequency recovers safety threshold, recovers and terminates process, does not recover and does not reach maximum round then iteration estimation correction, until up to standard or complete full round cut-off.The application solves the problems of low power shortage estimation accuracy, inaccurate load shedding and other problems in the prior art.

The invention provides a micro-electro-mechanical system device and a manufacturing method thereof. The micro-electro-mechanical system device comprises a substrate, a thin film layer and a plurality of patterned back plates. The film layer is disposed on the substrate and has a plurality of wavy structures. The top surface of the thin film layer has a rounded corner feature and the bottom surface of the thin film layer has a sharp corner feature. The plurality of patterned backboards are arranged above the thin film layer. The micro electro mechanical system device provided by the invention has relatively good performance in the characteristics of signal-to-noise ratio and low-frequency response attenuation frequency.

The invention provides an adaptive equalizer circuit and an operation method thereof. The adaptive equalizer circuit includes an amplifier circuit and an adaptive circuit. The amplifier circuit is coupled to the adaptive circuit. The amplifier circuit receives an input signal. The amplifier circuit provides a compensation signal to the adaptive circuit based on an input signal. The adaptability circuit provides a compensation setpoint and a feedback signal to the amplifier circuit based on the compensation signal. A low-frequency response and a high-frequency gain of the amplifier circuit are adjusted based on the feedback signal and the compensation setpoint, respectively.

Aspects of acoustic transducers are described. One aspect is a microelectromechanical (MEMS) transducer comprising a substrate and multiple cantilevered beams. A first cantilevered beam comprises a first protrusion and a first piezoelectric structure, where the first piezoelectric structure comprises a first deflection end and a first fixed end, where the first fixed end is coupled to the substrate, and where the first deflection end is cantilevered away from the substrate. The first cantilevered beam is separated from a second cantilevered beam by a gap. The first protrusion is disposed at the first deflection end and increases a thickness of the first cantilevered beam along the gap at the first deflection end. A second protrusion of the second beam is disposed at a second deflection end and increases a thickness of the second cantilevered beam along the gap at the second deflection end.

The application relates to the technical field of sound wave detection, in particular to a sound vibration cavity sensing structure based on a porous array type PZT, which comprises a cavity, a piezoelectric ceramic film, a positive electrode and a negative electrode. The piezoelectric ceramic film is arranged on the opening of the cavity and is fixedly connected with the opening end of the cavity. A plurality of half-through holes are arranged on the piezoelectric ceramic film. The positive electrode is arranged on the outer surface of the piezoelectric ceramic film, and the negative electrode is arranged on the inner surface of the piezoelectric ceramic film. The material of the piezoelectric ceramic film is lead zirconate titanate. The application has higher sensitivity and better low-frequency response performance, and has a good application prospect in the technical field of sound wave detection.

The invention discloses a sound wave balanced automobile loudspeaker which comprises an outer support, a U-shaped iron is installed at the axial first end of the outer support, a large voice diaphragm is arranged at the axial second end of the outer support, a first pole piece and a first permanent magnet are installed in the U-shaped iron, and a large voice coil is arranged between the first permanent magnet and the U-shaped iron in the axial direction. A magnetic cup is installed on the axial upper side of the permanent magnet, an inner support is embedded in the magnetic cup, a magnetic conductive ring is installed in the inner support, a second pole piece and a magnetic ring are installed on the inner side of the magnetic conductive ring, a second permanent magnet is installed on the upper side of the magnetic ring, a small voice coil covers the upper side of the second permanent magnet, and a small voice diaphragm is installed between the outer side of the small voice coil and the inner support. A sound wave equalizer located on the upper side of the small voice coil is installed in the middle of the large voice diaphragm. The problems that an existing automobile loudspeaker is difficult to give consideration to high and low frequency responses at the same time, low-frequency turbidity, high-frequency harsh or tone quality faults easily occur, and the broadband tone quality requirement cannot be met are solved.

The invention discloses an acceleration sensing system and a measurement method thereof, and belongs to the technical field of optical acceleration sensing. Linearly polarized light is output to the transduction module through the laser light source module, the transduction module comprises an MEMS transduction structure and a metasurface unit, and the metasurface unit decomposes the incident linearly polarized light into left-handed circularly polarized light and right-handed circularly polarized light and introduces initial phase modulation related to displacement. The reflected light module reflects the two beams of circularly polarized light back to the metasurface unit, so that the two beams of circularly polarized light pass twice, multiplication of phase modulation is achieved, and the phase modulation amount is increased to 8 times of that of single pass. The photoelectric detection module converts emergent light into two paths of orthogonal electric signals, the signal processing unit eliminates non-ideal errors through an orthogonal compensation algorithm, displacement is calculated through an orthogonal demodulation algorithm, and then acceleration signals are obtained. The method has the advantages of high sensitivity, large dynamic range and excellent low-frequency response, and is suitable for precise measurement scenes such as micro-vibration monitoring.

The utility model discloses a circular bone conduction vibrator which comprises a shell, a vibrating membrane, a permanent magnet and a driving coil, the shell is arranged to be in a circular ring shape, the vibrating membrane is arranged at the position, close to the top, in the shell, the driving coil is arranged at the position, close to the bottom, in the shell, and the vibrating membrane and the driving coil are arranged in an opposite mode. The permanent magnet is installed in the shell, the permanent magnet is arranged between the vibrating diaphragm and the driving coil, and the permanent magnet and the driving coil are oppositely arranged. According to the utility model, through the circular design, the vibrator structure is compact, miniaturization and integration are facilitated, and the wearing comfort is improved; the flexible vibrating diaphragm and the multi-layer wound driving coil are adopted, so that the low-frequency response and energy conversion efficiency are remarkably improved, and the tone quality is improved; the use of the high magnetic energy product permanent magnet enhances the magnetic field force, and improves the vibration effect and sound transmission efficiency of the vibrator.

The application relates to a kind of double-mechanism broadband vibration reduction methods based on local resonance and nonlinear damping of superhull, comprising: constructing linear vibrator for suppressing the low-frequency response peak of target shell using local resonance band gap;Linear vibrator includes: support structure, mass bin and linear mass unit;Replace linear mass unit with nonlinear mass unit of equal mass to obtain nonlinear vibrator;Construct a nonlinear damping effect model for nonlinear vibrator, used to optimize the adjustment parameters of nonlinear mass unit;Based on the setting of adjustment parameters, array the nonlinear vibrator on the target shell;Establish a vibration reduction prediction model for vibration reduction performance, and if the predicted vibration reduction performance meets the preset requirements, output the obtained nonlinear vibrator and its array mode for vibration reduction control of the target shell.The scheme realizes the double-mechanism coupling effect of local resonance band gap and nonlinear damping, and meets the demand of broadband vibration control.

The utility model discloses an interaction device, intelligent equipment and a vehicle, the interaction device comprises a vibration assembly and a connecting piece, and the vibration assembly is used for vibrating to produce sound; the connecting pieces are annularly arranged along the outer edge of the vibration assembly, and the connecting pieces are used for connecting the vibration assembly to an external component and transmitting vibration; the vibration assembly comprises a substrate and a piezoelectric piece, and the connecting face of the piezoelectric piece and the substrate is a continuous face. The interaction device provided by the utility model has relatively good low-frequency response.

The invention relates to the technical field of high polymer materials, in particular to a low-frequency response degradable self-reinforced piezoelectric composite material and a preparation method thereof. The self-reinforced piezoelectric composite material is prepared from the following components: stereocomplex polylactic acid and hydroxyapatite, the content of the hydroxyapatite is 5-30 wt% of the content of the stereocomplex polylactic acid; the low-frequency response degradable self-reinforced piezoelectric composite material has a mesoporous structure. The crystal of the degradable self-reinforced piezoelectric composite material with low-frequency response is a 100% stereocomplex crystal, and has excellent piezoelectric property.

The invention belongs to the technical field of new energy consumption, and discloses a multi-HESS distributed event trigger control system and method based on periodic communication, and the method comprises the steps: carrying out the droop control of a DC micro-grid, and achieving the power distribution of different HESSs through the adjustment of a virtual resistance value; a communication network between HESSs is constructed, and distributed control is adopted to carry out secondary regulation and control on DC bus voltage and power distribution; an event triggering mechanism is introduced into distributed control, and the convergence of the proposed method is verified based on a Lyapunov stability theory. According to the invention, a bottom layer uses a low-pass filter to carry out frequency division processing on reference current, so that high-frequency response of the super capacitor and low-frequency response of the storage battery are realized.

This invention relates to the field of force sensor technology, and discloses a six-dimensional force sensor, comprising: a mounting base; an inner core and a cover plate, the cover plate being rotatable relative to the inner core around a first direction and a second direction, driving the inner core to rotate around a third direction and move along the first direction, the second direction, and the third direction; a first rotational connection assembly; a first tangential force-sensitive core for detecting a first tangential force; a second rotational connection assembly; a second tangential force-sensitive core for detecting a second tangential force; a third tangential force-sensitive core for detecting a third tangential force; a force transmission element sleeved on the inner core; a first-direction force-sensitive core for detecting a first applied force; a second-direction force-sensitive core for detecting a second applied force; a second force transmission element fixed to a movable component; and a third-direction force-sensitive core for detecting a third applied force. The six-dimensional force sensor disclosed in this invention improves upon the shortcomings of strain gauge-type six-dimensional force sensors, such as low detection accuracy, poor creep resistance, low frequency response, and significant temperature drift.

A low-frequency optical fiber acceleration sensor provided by the present invention comprises a bottom plate, a sensing body and a cover body, the sensing body is arranged on the bottom plate, the sensing body comprises a connecting plate, a central cabin is arranged on the connecting plate, a first flexible carrier plate is arranged in the central cabin, a first end of the first flexible carrier plate is fixedly connected with the central cabin, and a second end of the first flexible carrier plate is fixedly connected with the cover body. A first rigid mass block is fixedly arranged at the second end of the first flexible carrier plate and can swing left and right relative to the first end of the first flexible carrier plate, a first fiber bragg grating is arranged on the left side face of the first flexible carrier plate, and a second fiber bragg grating is arranged on the right side face of the first flexible carrier plate. The first fiber bragg grating and the second fiber bragg grating extend along the length direction of the first flexible carrier plate; the cover body is connected to the upper portion of the connecting plate and used for sealing the central cabin body. The problems that an existing acceleration sensor is poor in low-frequency response, prone to electromagnetic interference, poor in corrosion resistance, insufficient in sensitivity and the like in ocean engineering application are solved.

The application belongs to the technical field of ground-air electromagnetic detection, and specifically relates to a damping-self-integration integrated ground-air frequency domain electromagnetic wideband receiving system and method, which comprises: a hollow coil sensor for sensing a ground magnetic field signal and outputting an induced electromotive force based on a Faraday electromagnetic induction law; an active integration circuit connected with the output end of the hollow coil sensor through an input end and used for analog integration compensation of the induced electromotive force; a signal conditioning unit used for gain adjustment, high-frequency noise filtering and power frequency noise notch processing of the integrated voltage signal, and output of a conditioned analog voltage signal; and a signal acquisition unit used for conversion of the conditioned analog voltage signal into a digital signal and execution of an acquisition action in response to an external synchronous trigger signal. The application improves the low-frequency response characteristic of the coil, so that the amplitude of a low-frequency signal reaches the same level as that of a high-frequency signal.