52results about How to "Improve detection distance" patented technology

The invention relates to the technical field of logging while drilling, and discloses a near-bit stratum detection method, system and device, electronic equipment and a medium, and the method comprises the steps: transmitting a seismic wave to a to-be-detected stratum in front of a drill bit through an underground vibroseis, and receiving a reflected wave signal of the to-be-detected stratum through a geophone; calculating the relative position of the stratum in front of the drill to the drill in real time according to the reflected wave signal; acquiring a first lithologic seismic wave characteristic parameter of the reflected wave signal and a second lithologic seismic wave characteristic parameter of a known typical stratum; matching the first lithologic characteristic wave characteristic parameter with the second lithologic seismic wave characteristic parameter, and determining the formation lithology and the geological structure of the formation to be detected; outputting the stratum information of the to-be-measured stratum including the distance data, the stratum lithology and the geological structure; the seismic waves are not affected by various complex geological environments, the stratum information of the stratum to be measured can be accurately obtained, the drilling risk is reduced, and the drilling efficiency and safety are improved.

The invention provides an optical system of a laser radar transmitting lens. The optical system comprises a first lens, a second lens, a diaphragm, a third lens, a fourth lens, a fifth lens, an optical filter, protective glass and an image surface which are arranged in a direction from an object side to an image side. According to the invention, by reasonably using the lenses with specific shapes and structures and limiting the focal power of each lens, the field angle of the optical system is increased to 150 degrees and the relative illumination is greater than 90%, the radar detection field of view is wider and clearer, the F-theta distortion is less than 1%, the CRA is less than 1 degree, the detection distance and precision are improved, and the detection cost is reduced. According to the utility model, more accurate distance measurement data and farther detection distance can be provided, TTL is 29 mm, the size is small, miniaturization can be realized, the camera can be arranged in a vehicle, the matching of 2G3P glass and plastic enables the whole optical system to optimize high and low temperature excursion compensation, it is ensured that the lens does not have virtual focus at high and low temperatures, the cost is more advantageous, and the cost performance is higher.

The invention discloses a method for enhancing intelligent construction site fire recognition capability by using an AI large model, relates to the field of fire recognition, and solves the technical problems of limited detection distance and insufficient blind fire detection in the existing fire recognition technology. The method comprises a blind fire identification model construction step and a blind fire identification analysis step, and the blind fire identification model construction step comprises the following steps: S11, collecting a blind fire training sample which comprises first characteristic values of a hidden heat source, an air expansion distortion phenomenon and a light refraction phenomenon; and S12, training the blind fire training sample through a deep convolutional neural network model. Compared with a traditional fire identification algorithm, the method reduces the dependence on a smoke sensing alarm and a temperature sensing fire detector, obviously increases the detection distance of the fire, can achieve the timely blind fire early warning, can prevent a part of the fire, and guarantees the project progress and construction safety.

The present invention relates to a laser scanning device and method based on on-chip soliton frequency comb without mechanical scanning. The laser scanning device includes a broadband laser, an arbitrary signal generator, an electro-optical phase modulator, a core frequency comb chip and a two-dimensional optical phased array chip; the output end of the broadband laser is connected to the light source input port of the electro-optical phase modulator, and the output port of the arbitrary signal generator is connected to the microwave signal input port of the electro-optical phase modulator; the waveform output port of the electro-optical phase modulator is connected to the input port of the core frequency comb chip, and the output port of the core frequency comb chip is connected to the input port of the two-dimensional optical phased array chip. The present invention utilizes the principle of frequency modulated continuous wave coherent ranging, generates parallel multi-channel light sources through frequency comb chips, combines optical phased arrays and gratings to achieve two-dimensional non-mechanical scanning, and adopts a planar array light scanning method, which has faster scanning speed, higher efficiency and longer detection distance.

The invention relates to the technical field of radar antennas, and provides a filtering antenna and an antenna system for a vehicle-mounted millimeter wave radar, the filtering antenna comprises a microstrip array antenna structure, a parasitic branch filtering structure and a feed transmission line, and the parasitic branch filtering structure is connected with the microstrip array antenna structure through the feed transmission line; a parasitic stub filtering structure of a short stub is added to a single side of the antenna, and a fan-shaped patch structure is arranged to form an adjusting circuit capacitive element by changing the radius of an open circuit fan-shaped stub structure; an inductive adjusting element is formed by combining a microstrip structure and a ground connection copper-clad hole, high-frequency coupling signal filtering is achieved, the influence on the amplitude and phase performance of the microstrip array antenna structure is small, more MIMO antenna channels are arranged on a low-cost and small-size radar PCB, meanwhile, the problems that coupling is serious and isolation is poor between the antenna channels are solved, and the antenna performance is improved. A miniaturized and high-isolation millimeter wave radar MIMO technology is realized, and the isolation between MIMO antenna channels of the whole board can be improved to 30 db or more.

The present invention relates to a distance detection of ozone, and in particular to an optimization method for improving the detection distance of an ozone laser radar, comprising the following steps: selecting different convolution kernels according to different distance heights of the signal; denoising the noise in the echo signal by a sliding convolution filtering method to obtain a smooth signal; using the smoothed signal to calculate the extinction coefficient and the backscattering coefficient; and calculating the ozone concentration on the vertical contour line. The optimization method for improving the detection distance of an ozone laser radar provided by the present invention adopts a new convolution noise reduction algorithm, and its characteristic of changing the sliding window size retains rich high-altitude ozone information while smoothing the signal, and effectively reduces noise, thereby achieving an improvement in the signal-to-noise ratio. Through experimental verification, the detection distance is increased from 2.5km to 5.0km, greatly improving the ozone detection distance.

This disclosure relates to a lidar, a scanner for the lidar, and an apparatus. The lidar includes a transmitter and a scanner. The transmitter is configured to emit a probe light. The scanner is configured to oscillate about a rotation axis within an oscillation range, deflecting the probe light into a field of view. The oscillation range includes a first fixed-speed region, a first variable-speed transition region, and a second fixed-speed region along a first direction. The first direction is perpendicular to the rotation axis. The scanner rotates at a greater speed in the first fixed-speed region than it rotates at the second fixed-speed region. In the first variable-speed transition region, the scanner's rotational speed varies with angle according to a half-period cosine function.

The present invention belongs to the field of advanced geological prediction, and discloses a multi-pulse spark source directional acoustic wave advanced detection system and an advanced geological prediction method. The system includes a directional spark excitation source, an acoustic wave receiving sensor, a host computer, and a multi-level energy storage capacitor; there are multiple directional spark excitation sources, and each of them can independently excite a directional high-frequency acoustic wave signal; each directional spark excitation source is equipped with a rotation azimuth controller; there are multiple acoustic wave receiving sensors; the multi-level energy storage capacitor is connected to each directional spark excitation source, and is used to apply multi-pulse spark signal excitation to each directional spark excitation source. The present invention utilizes a directional spark excitation source and multiple pulse excitations to enhance the propagation distance of the acoustic wave signal, and through the directional spark source acoustic wave excitation and multi-band signal superposition, all-round directional focusing is performed in front of the excavation face to enhance the resolution of poor geological bodies, thereby obtaining an accurate description of the location and occurrence state of abnormal geological bodies.

The utility model discloses a broadband wide beam antenna and a vehicle millimeter wave radar, the antenna comprises a first feed line, a plurality of radiators and a plurality of parasitic radiators, the plurality of radiators are distributed at two sides of the first feed line along the extension direction of the first feed line and are connected with the first feed line, and the parasitic radiators are distributed at two sides of the first feed line along the extension direction of the first feed line. The multiple parasitic radiators are arranged on the first side or the second side of the first feeder line, and each parasitic radiator is located on one side of one radiator on the same side as the parasitic radiator. According to the antenna provided by the utility model, the first feeder line, the plurality of radiators and the plurality of parasitic radiators are arranged on the same plane, so that the manufacturing is convenient, the processing cost is reduced, the shaping is realized by optimizing the number of the radiators, adjusting the length of the first feeder line between two adjacent radiators and the width of the radiators, and using a single antenna, so that the antenna is more compact. The size of the antenna is greatly reduced, and the input amplitude of the radiating body is adjusted by combining the additionally arranged parasitic radiating body, so that the beam direction and the beam width of the antenna are adjusted.

The utility model relates to the technical field of elevator braking distance detection, and provides a traction driving elevator braking distance detection device which comprises an elevator detection assembly and an elevator car, and the elevator detection assembly comprises a wall body, a supporting plate, a traction wheel, a fixing plate, a rope and a traction machine. By arranging the limiting structure, the rope passes through the top end of the guide wheel, the support is moved to the position above the guide wheel, one end of the clamping block abuts against one end of the clamping groove, the support is pressed, under the action of the reserved groove, the support drives the clamping block to move into the clamping groove through the connecting block, and then the support and the guide base are fixed to each other; according to the traction drive elevator braking distance detection device, the limiting groove is formed in the limiting seat, under the cooperation of the guide wheel and the limiting groove, the rope is prevented from being disengaged when the rope passes through the top end of the guide wheel, the function that the device is convenient to limit is achieved, and therefore the applicability of the traction drive elevator braking distance detection device in use is improved.

The invention relates to the technical field of laser radars, in particular to an anti-intrusion laser radar active detection device which is characterized by comprising a base and a cover body arranged at the top of the base, and a fixing fastener, a laser radar assembly and an adjusting assembly are arranged in the cover body. The laser radar assembly comprises a laser transmitter, a beam shaper and a receiver, the laser transmitter and the beam shaper are respectively arranged at the lower half parts of the inner sides of the two different fixing fasteners, and the receiver is arranged on the outer surface of the fixing fastener close to the beam shaper; the outer side wall, close to the laser emitter, of the fixing fastener is provided with an adjusting assembly used for controlling the laser emission amount, and an adjusting assembly used for controlling the light inlet amount of the receiver is arranged between the fixing fastener and the receiver. Accurate laser detection is achieved through the laser radar assembly, and the laser emission amount and the receiver light inlet amount can be flexibly controlled and adjusted through the adjusting assembly so as to adapt to detection requirements and condition changes in different environments.

This invention relates to electromagnetic logging technology and discloses a forward-focusing electromagnetic logging method while drilling, comprising two stages: (1) Pre-testing stage: using a magnetic ring antenna array arranged in a straight line along the drill collar, the last antenna is used as a reference antenna to transmit signals, and the preceding antennas simultaneously receive them, so as to synchronously acquire the amplitude and phase delay of the received signals of each preceding antenna. (2) Forward focusing stage: configuring the transmission parameters for the preceding antennas, setting their initial phase to the negative value of the measured phase delay, and calculating an inversely proportional weighting coefficient based on the received amplitude, thereby configuring the driving amplitude of each preceding antenna; finally, driving the reference antenna and the configured preceding antennas to transmit synchronously, and coherently superimposing them in front of the drill bit to form a focused beam, while weakening the signal interference from the instrument's sides and back to the formation. This invention does not require pre-setting equipment in un-drilled formations, is fully compatible with existing instruments, and can significantly improve the signal strength and signal-to-noise ratio of forward detection.

The invention relates to the technical field of wireless communication, in particular to a risk early warning method, device and equipment, a medium and a product, the method is applied to a computing power server, and the method comprises the following steps: acquiring perception information reported by reconfigurable intelligent metasurface equipment and aircraft information reported by a low-altitude aircraft; matching the sensing information with the aircraft information to obtain a matching result; wherein the matching result is used for indicating whether a sensing target corresponding to the low-altitude aircraft is included in a plurality of sensing targets in a signal coverage range of the reconfigurable intelligent metasurface equipment; based on the matching result, determining collision risks between the low-altitude aircraft and other sensing targets except the sensing target corresponding to the low-altitude aircraft; and under the condition that the collision risk meets an early warning requirement, generating risk early warning information, and returning the risk early warning information to the low-altitude aircraft.

The invention relates to a laser radar system, which comprises at least two groups of receiving and transmitting modules and a single-axis galvanometer, the receiving and transmitting modules are arranged at intervals, laser emitted by each group of receiving and transmitting modules enters the single-axis galvanometer at different preset angles, the laser is reflected by the single-axis galvanometer to scan a target, and the laser subjected to diffuse reflection by the target is reflected back to the receiving and transmitting modules through the single-axis galvanometer; wherein scanning ranges covered by at least two groups of adjacent receiving and transmitting modules are partially overlapped, and the at least two groups of adjacent receiving and transmitting modules adopt time-sharing emission or code the laser, so that mutual interference of the laser emitted by the at least two groups of adjacent receiving and transmitting modules is avoided.

The present invention discloses an intelligent automobile headlight system, wherein the signal output end of the central computing unit is connected to the headlight control drive module and transmits the headlight control instruction to it, the headlight control drive module is connected to the automobile headlight actuator module and transmits the drive signal to it, a camera for collecting the image information in front of the vehicle is fixed at the front of the vehicle, the camera is connected to the central computing unit and transmits the image information to it, a positioning module is installed in the vehicle, the positioning module is connected to the central computing unit and transmits the current position signal to it. The system can automatically control the working condition of the high beam, and cooperate with the distant vehicle to improve the safety of the vehicle.

The invention relates to a subarray core design of a large-aperture underwater acoustic linear array. A subarray core is composed of a head end connector 1, a bearing rope 2, a depth sensor 3, a hydrophone 4, an electromagnetic shielding net 5, a hydrophone signal amplification circuit board 6, an internal wire 7, a pipe support 8, a damping sponge 9, a PU sheath tube 10, medium silicone oil 11, a buckling ring 12 and a tail end connector 13. According to the design, the mutual cascading function of the subarrays is considered, the array forming requirement of a large-aperture array can be met, and the linear array has the advantages of being high in detection precision and distance, resistant to water pressure, resistant to seawater corrosion, resistant to electromagnetic interference, capable of reducing water flow impact vibration, stable, reliable and the like.

The application relates to the fields of optics and fire rescue, and discloses a fluorescent conversion sheet with wavelength conversion function and a handheld smoke penetration imaging device. The fluorescent conversion sheet comprises, in sequence, a heat dissipation substrate layer, a mirror layer, a photonic crystal layer and a core-shell structure fluorescent layer. After short-wave near-infrared laser is incident, the core-shell structure fluorescent layer performs wavelength conversion; the mirror layer and the photonic crystal layer form an optical micro resonant cavity, and the unconverted laser is reflected back to the fluorescent layer for secondary conversion; and the heat dissipation substrate layer effectively suppresses the thermal quenching effect. The imaging device utilizes the fluorescent conversion sheet to efficiently convert the easily obtained short-wave near-infrared laser into middle-wave near-infrared laser with strong smoke penetration capability and safety to human eyes and emits the middle-wave near-infrared laser, and a receiving device containing a polarizer is used to image the target echo. Through systematic and synergistic optimization design, the conversion efficiency and thermal stability are greatly improved, excellent smoke penetration imaging effect is realized, and the safety and efficiency of fire rescue are improved.

The present application belongs to the technical field of laser radar measurement, and provides a pseudo-random code phase modulation wind measurement laser radar signal-to-noise ratio improving method and system, the method comprising: generating a pseudo-random code sequence, BPSK phase modulating a continuous wave seed laser to convert into an encoded pulse signal; transmitting the encoded pulse signal to the atmosphere, receiving a back wave and mixing with a local oscillator light; multiplying the coherent beat frequency signal with the same pseudo-random code sequence and integrating, so that the back wave signal of the matching distance gate obtains coherent accumulation gain in the correlation output, and the non-matching signal energy is expanded to a noise base, realizing correlation demodulation; performing spectrum analysis on the demodulated signal, and inverting the wind speed. The present application significantly improves the average power and processing gain under the premise of not improving the peak power through high duty cycle encoding pulse and pseudo-random code correlation demodulation, thereby improving the signal-to-noise ratio and detection distance.

The application discloses a pipeline defect Barkhausen coding excitation ultrasonic detection system, which comprises a measured pipeline, an excitation module, a receiving module and an EMAT transducing coil; the excitation module generates an AC excitation signal which is coded and modulated and is power-amplified through a full-bridge inverter circuit; the AC excitation signal excites a dynamic magnetic field after being input into the EMAT transducing coil, the dynamic magnetic field is superimposed with a static magnetic field provided by a permanent magnet, the magnetic field dynamically changes under a static working point, the changing magnetic field excites a torsional guided wave in a magnetostrictive patch, and the torsional guided wave is transmitted along the measured pipeline in an axial direction; the torsional guided wave signal is transmitted to the receiving module, a waveform signal of an oscilloscope is collected after being amplified, and a narrow pulse echo with a relatively large main and side lobe and a relatively high amplitude is obtained through corresponding matched filtering processing; the waveform signal after the matched filtering is analyzed, and qualitative analysis is conducted on the pipeline defect. The application transmits a wide pulse signal with large energy, and matched filtering processing is conducted at a receiving end, so that an echo signal with a relatively narrow main lobe and a relatively high amplitude is obtained, and therefore the detection capability of the pipeline defect is effectively improved.

The present invention provides a target detection imaging system and method based on a fiber laser phased array, comprising a fiber laser phased array light source, for generating an array fiber laser with a high-speed variable intensity distribution, wherein the array fiber laser is composed of a plurality of phase-controllable fiber lasers; a light splitting unit divides the array fiber laser into an emission light and a reference light; an emission optical system projects the emission light onto the target surface; a reference optical system collects the intensity distribution of the reference light; a receiving optical system receives the return light reflected from the target and collects its intensity distribution; a computing control system implements phase control on each fiber laser in the array fiber laser, so that its intensity distribution changes at a high speed, and reconstructs the target image based on the intensity distribution of the reference light and the intensity distribution of the return light. The present invention has the characteristics of high emission power, fast refresh rate, and convenient control of the field of view of the illumination light field, and can significantly improve the target detection distance and the correlation imaging speed.

A method for generating low-frequency limited acoustic beams in a well, the method comprising: determining a transducer aperture according to a downhole borehole size, calculating a nonlinear action region of a radiated acoustic field based on the transducer aperture and a distance parameter; selecting a sound source design modulation theory model according to the nonlinear action region, determining sound source parameters of the transducer based on the sound source design modulation theory model and the transducer aperture; carrying out nonlinear radiated acoustic field simulation according to the sound source parameters, determining a critical propagation distance corresponding to a maximum value of a difference frequency sound source level, and extracting nonlinear acoustic wave signal characteristics at the distance, generating a loadable modulation signal based on the characteristics; measuring and comparing signal characteristics of the transducer under a loadable modulation signal loading state and under a natural radiated modulation signal loading state, and determining the loadable modulation signal with a larger difference frequency sound source level. The present application can generate nonlinear acoustic wave signals containing larger low-frequency components at a smaller radiated distance, and the difference frequency conversion efficiency of the generated nonlinear radiated signals is high.

The present invention discloses a drone countermeasure system based on aerial relay, comprising: a ground countermeasure system, which is arranged on the ground and used to detect the wireless signal of the target drone, and transmits a countermeasure signal after detecting the wireless signal of the target drone; at least one relay system, each relay system is mounted on an aircraft, so as to be arranged in the air through the aircraft, and the relay system is used to detect the wireless signal of the target drone, and after detecting the wireless signal of the target drone, the detection result is sent to the ground countermeasure system or other adjacent relay systems. The present invention can expand the detection range, increase the detection distance, and can detect farther places, avoiding the detection blind spots caused by obstacles.

This invention relates to a vertical array transmit beam optimization method based on deep-sea acoustic field feature prediction. Addressing the problem of long-range active detection, this method proposes a vertical array transmit beam optimization approach based on deep-sea acoustic field feature prediction. The method uses the average sound intensity level in the convergence zone as the beam optimization design criterion, and designs the main lobe width of the transmit beam in conjunction with the critical exit angle range of the inverted acoustic ray. This concentrates the transmitted energy in the main lobe direction while minimizing the sidelobe level to achieve sound intensity focusing in the convergence zone. Global optimization is then performed in different convergence zones to achieve the highest average sound intensity level for each zone. Compared with conventional beamforming methods, under the same transmit power conditions, the transmit beam control using the beam optimization method based on deep-sea acoustic field feature prediction can achieve a higher average sound intensity level in the convergence zone, effectively increasing the detection range and demonstrating promising application prospects.

The invention relates to an infrared multi-band intelligent fire behavior identification method and system based on a time sequence classification model, belongs to the technical field of fire behavior identification, and solves the problems that in the prior art, the identification distance is short, the anti-interference capability is weak, misjudgment is easily caused, and reliable identification cannot be realized when radiation is strong. Comprising the steps of collecting environmental radiation intensity data and performing preprocessing; inputting the data obtained after preprocessing into a time sequence classification model to obtain an identification result; the model comprises a flame feature extraction module which is used for calculating a flame matching coefficient by using data of an optimal wave band; the multi-band information fusion module is used for calculating the probability of fire behavior estimation by using the flame matching coefficient, the absolute radiation intensity mean value of the main band and the relative radiation intensity mean value of the auxiliary band; the saturation judgment module is used for judging whether the main wave band is saturated; and the threshold judgment module is used for judging whether a fire occurs or not. And the identification distance is long, the anti-interference capability is strong, and the reliable identification can still be realized when the radiation is strong.

The invention discloses a bucket tooth falling-off monitoring device and an excavator, and belongs to the technical field of mining machinery, the bucket tooth falling-off monitoring device comprises a monitoring mechanism, the monitoring mechanism comprises a monitoring assembly and a magnet assembly, a first connecting position is arranged in a containing groove, and a second connecting position is arranged at the position, right opposite to the first connecting position, of the head of a tooth holder; one of the first connecting position and the second connecting position is provided with a monitoring assembly, the other connecting position is provided with a magnet assembly, the distance between the monitoring assembly and the magnet assembly is a first distance value, and the monitoring assembly judges the first distance value by judging the change of the oscillation amplitude of an LRC circuit of the monitoring assembly caused by the change of the distance between the magnet assembly and the monitoring assembly; and when the oscillation amplitude is higher than a threshold value, the monitoring assembly generates prompt information. The excavator is provided with the bucket tooth falling monitoring device. Through cooperation of the detection assembly and the magnet assembly, the monitoring effect is optimized, and the monitoring distance of the monitoring assembly is increased.

The present invention relates to a multi-layer structure waveguide grating antenna based on staggered etching for use in an optical phased array and a preparation method thereof, comprising, from bottom to top, a substrate (1), a waveguide region and a top oxide layer (5); the waveguide region comprises, from bottom to top, a first waveguide layer (2), an isolation layer (3) and a second waveguide layer (4); wherein the second waveguide layer (4) has staggered deep and shallow grooves. The present invention reduces the leakage of light to the substrate, increases the proportion of light emitted upward, thereby improving the emission efficiency of the grating, and has the advantage of a long effective emission length, which is helpful to improve the detection distance of the phased array and realize high-power output devices.

This application provides a time-of-flight statistics device and a laser ranging device, relating to the field of laser ranging technology. The statistics device includes a statistics unit and a memory: the statistics unit is used to acquire S sets of first initial flight time data within S first integration periods, and to accumulate each first initial flight time data set by grouping every N adjacent first initial flight time data sets to obtain S sets of accumulated flight time data corresponding to the S sets of first initial flight time data, where S is a positive integer, S≥2, and N is a positive integer, N≥2; and to superimpose the S sets of accumulated flight time data to obtain a superimposed flight time data set, and to store at least one superimposed photon count value in the superimposed flight time data set in the memory as a single superimposed photon count value stored in a memory unit; this statistics device can increase the detection range of the laser ranging device.

The invention relates to a divergence angle regulation and control method and a vortex beam radar, and relates to the technical field of vortex beam radars. The method comprises the following steps: acquiring a target divergence angle and radar basic parameters; determining a divergence angle control phase based on the target divergence angle and the radar basic parameters; determining a feed source compensation phase based on the distance from the metasurface unit to the feed source; determining a vortex phase based on the position of the metasurface unit; determining a total phase based on the divergence angle control phase, the feed source compensation phase and the vortex phase; and adjusting the unit structure of the corresponding metasurface unit based on the total phase. By loading the divergence angle control phase in the total phase, the beam main lobe divergence angles of different modes can be unified as the target divergence angle, so that the problem that the divergence angles of beams of different modes are different is solved, cooperative receiving of signals, mode decoupling and information reconstruction are facilitated, and the detection precision and the operating distance of the vortex beam radar are improved.

The present invention belongs to the field of tunnel construction detection. In order to solve the problem that it is currently impossible to accurately detect small and medium-sized unfavorable geological bodies such as meter-level and sub-meter-level, a method and device for advanced geological detection of tunnel boring machine construction focused shear sound waves are provided. Among them, the tunnel boring machine construction focused shear sound wave advanced geological detection device includes a shear wave excitation module, a reflection wave acquisition module and a signal processing module; the shear wave excitation module uses the multi-point source signal delayed excitation focusing principle to excite and generate high-frequency focused sound waves, so that the high-frequency focused sound waves can achieve sound wave energy convergence and conversion into shear waves in front of the tunnel boring machine; the reflection wave acquisition module is used to collect the reflection waves generated when the shear waves encounter abnormal bodies; the signal processing module is used to receive the reflection waves collected by the reflection wave acquisition module, and use the time-frequency domain polarization weighted filtering method to extract the shear wave signal in the reflection wave, and then based on reverse time migration imaging, the meter-level and sub-meter-level abnormal body fine imaging is realized.

The present invention discloses a long-distance WiFi signal positioning method and device, the method comprising: obtaining channel state information and round-trip time distance information; performing beam synthesis on the channel state information to obtain positioning feature parameter information; using the round-trip time distance information and the positioning feature parameter information to train a preset positioning model to obtain an optimized positioning model; using the optimized positioning model to process the channel state information and round-trip time distance information to be processed to obtain a positioning result. The method of the present invention comprehensively utilizes channel state information, round-trip time distance information and beam synthesis method to enhance the signal-to-noise ratio of the received signal, obtain a more accurate WiFi signal, effectively improve the detection distance of the WiFi signal, and improve the positioning accuracy.