209 results about "Wave trough" patented technology

The invention provides a three-dimensional skin waviness fitting analysis method. The method comprises the following steps: performing boundary analysis on skin point cloud data obtained by laser measurement, performing interpolation sampling from the point cloud data according to a specified area and resolution to obtain point cloud coordinates which can reflect the real condition of the skin and are regularly arranged, performing bicubic spline surface least square approximation based on a sampling point set, and calculating the skin point cloud data according to the bicubic spline surface least square approximation. The method comprises the following steps: acquiring a reference curved surface reflecting the overall distribution trend of an analysis area, calculating distance deviation from a sampling point to the reference curved surface, carrying out filtering smoothing processing, forming a smooth deviation curved surface capable of reflecting the deviation condition of a measurement curved surface, extracting information such as wave crest and wave trough positions, wave amplitude, wavelength and slope in the deviation curved surface, and carrying out skin waviness characteristic analysis. According to the method, the tiny waviness characteristics of the irregular curvature surface of the aircraft can be extracted, the skin waviness distribution condition can be visually displayed, and the method has the advantages of being wide in applicability, small in error, high in reliability, low in time cost and the like.

The invention provides an aviation nacelle part waviness automatic detection and evaluation method, and belongs to the field of product production detection, and the method comprises the steps: carrying out the protocol scanning of part surface contour features, and obtaining the undistorted coordinate point discrete point cloud data of the actual surface contour; filtering the point cloud data; obtaining a piece of flattened deviation value discrete point cloud data; obtaining a flattened deviation value continuous curve by adopting a general standard curve reduction method; extracting waviness components, and obtaining a curve center line; obtaining a crest value and a trough value participating in calculation; and calculating the maximum wave amplitude, the waviness and the slope for evaluating the waviness by using the wave peak value and the wave trough value. According to the method, the relation between the minimum cut-off wavelength of the waviness and the sampling interval is stipulated, the undistorted reduction of the surface profile curve is ensured, the influence of non-waviness profile components in the digital evaluation of the waviness is eliminated through a combined calculation method, and the evaluation accuracy of the waviness of the aviation nacelle part is improved.

The invention belongs to the technical field of spectral analysis, and particularly discloses a Raman spectrum baseline correction method, device and system, a medium and equipment, and the method comprises the steps: obtaining a to-be-processed original Raman spectrum, recognizing trough points of the original Raman spectrum, and screening the recognized trough points to obtain baseline trough points; fitting the base line wave trough points to obtain a Raman spectrum base line; and correcting the Raman spectrum baseline to obtain a corrected Raman spectrum. Through multi-stage trough point screening and adaptive fitting, background interference can be effectively eliminated, and the signal-to-noise ratio and the characteristic peak fidelity of the Raman spectrum can be improved.

The invention relates to the technical field of electric energy conversion, and discloses a high-frequency resonant topology-driven isolation power conversion system, which comprises a power conversion circuit, a driving unit, a feature sensing unit and a logic regulation and control unit, and is characterized in that the logic regulation and control unit extracts a parasitic ringing extreme point of a voltage evolution waveform in dead time; a charge release balance point is determined by calculating an arithmetic mean value of the first wave crest and the first wave trough, and high-frequency parasitic parameter interference is stripped; and predicting a time domain window of a return-to-zero potential based on a charge release balance point, performing phase compensation on a driving pulse in the time domain window according to a voltage waveform second derivative feature, and locking the starting moment of a switching tube at a zero voltage point. Interference of high-frequency distribution electromagnetic parameters on conduction judgment is eliminated, and soft switching self-healing in a full-load domain is achieved.

The invention discloses an aircraft surface waviness measurement and analysis method and system, and the method comprises the steps: scanning the surface of an aircraft according to a planned path through employing a three-coordinate measuring machine and a scanning probe, obtaining scanning data, and obtaining the scanning data for evaluation through employing a segmented scanning and segment-to-segment direct splicing mode for a hole, a pin and other structural parts; fitting based on scanning data to obtain a point deviation data set, calculating corresponding point arc length data based on the point deviation data and the point coordinate data on this basis, and drawing a graph by taking a horizontal axis as the point arc length data and a longitudinal axis as the point deviation data; and determining the surface waviness of the airplane by combining the derivative at the intersection point of the point deviation data curve and the transverse axis and the distance between the wave crest and the wave trough, thereby realizing the efficient and accurate measurement of cavities, welding seams and other obstacle structures on the outer surface of a large-scale airplane part or the whole machine and the accurate calculation of the waviness.

The present application relates to the technical field of oil reservoir exploration, and particularly relates to a fracture-cave seismic facies identification method and device, which comprises the following steps: obtaining each reservoir section range of a fracture-cave reservoir; obtaining the seismic reflection energy intensity of each reservoir section of the fracture-cave reservoir; obtaining the seismic waveform characteristics of each reservoir section, wherein the seismic waveform characteristics are any one of the following: a first type of seismic waveform with both wave peaks and wave troughs, and a second type of seismic waveform with only wave peaks or only wave troughs; determining the seismic facies category of each reservoir section of the fracture-cave reservoir based on the seismic waveform characteristics and the seismic reflection energy intensity, thereby providing an important basis for the exploration and development of the carbonate rock fracture-cave oil reservoir through effective identification of the seismic facies.

The invention belongs to the technical field of net mold frames for hollow internal mold metal net cement partition walls, and discloses a net mold frame for a hollow internal mold metal net cement partition wall and a method for building the hollow internal mold metal net cement partition wall. The main technical characteristics are as follows: two opposite wave-shaped meshes are included, wave troughs of the two meshes are attached together, wave crests of the two meshes are opposite, a cavity is formed between the wave crests of the two meshes, vertical keels are arranged in the cavity, the vertical keels are bound and fixed with the meshes, and the vertical keels are arranged in the cavity. Vertical supporting frames are arranged at the wave trough positions of the two meshes, and the vertical supporting frames are fixed to the meshes. The upper embedded steel bars and the lower embedded steel bars are connected together through the vertical supporting frames, the vertical supporting frames are arranged at intervals, and the anti-collision performance and the anti-seismic performance of the wall are greatly improved.

The invention discloses a rolling force calculation method for longitudinal wave rolling of a metal plate, and relates to the technical field of rolling. The rolling force calculation method for longitudinal wave rolling of the metal plate comprises the steps that based on rolling parameters of longitudinal wave rolling equipment and a neutral angle in the rolling process of the longitudinal wave rolling equipment, plastic deformation area rolling force at the wave trough position and the wave waist position of the longitudinal wave rolling equipment is determined; and the total rolling force of the plastic deformation area of the longitudinal wave rolling equipment is determined according to the rolling force of the plastic deformation area at the wave trough and the wave waist of the longitudinal wave rolling equipment. Accurate calculation of the total rolling force of the plastic deformation area is achieved, and the calculation efficiency of the rolling force is improved.

The application provides an ultrasonic fingerprint readout circuit, an ultrasonic fingerprint chip and an ultrasonic fingerprint module. The ultrasonic fingerprint readout circuit comprises a sensing circuit, a single-ended-to-dual-ended circuit and a bidirectional integration circuit which are coupled in sequence. Compared with a conventional ultrasonic fingerprint readout circuit, two noise sources are saved, bidirectional integration (integration from a wave peak to a wave trough and from a wave trough to a wave peak) is realized through a differential working mode, the output signal quantity is doubled, the output noise is reduced, the signal-to-noise ratio is greatly improved, the anti-interference capability is better, and the additional circuit cost is not increased too much.

The invention relates to a reservoir identification method, and belongs to the technical field of oil-gas exploration and development. And determining the reservoir development condition of the target stratum by using the seismic data, the logging data and the gas testing data of the target stratum. Based on the reservoir development condition of the target stratum, wave crest and wave trough positions of the target stratum are determined through well seismic calibration and forward modeling, and structural interpretation is conducted on the wave crest and wave trough positions of the target stratum. And determining the seismic reflection characteristics of the reservoir by using a structural interpretation result, a multi-well synthetic record and a forward modeling result. Subtracting the wave trough horizon from the obtained wave crest horizon of the target layer to obtain a wave trough-to-wave crest interval time plane graph, and utilizing the interval time plane graph to construct a high-timeliness deposition interface. And recognizing the reservoir according to the determined seismic reflection characteristics of the reservoir and the constructed high-temporal sedimentary interface. According to the method, the problems that the improvement of the seismic data resolution is limited and the identification result is easily interfered by the seismic event time penetration, so that the reservoir identification precision is relatively low are effectively solved.

The invention provides a spiral-like sensing assembly and an imaging system thereof, and belongs to the technical field of sensing and detection. The sensing assembly comprises a bottom lining layer and a vibration diaphragm layer, the bottom lining layer is of a spiral-like cavity structure, the vibration diaphragm layer comprises a supporting layer, a plurality of electrode layers and at least one piezoelectric layer, and the positions of the supporting layer, the electrode layers and the piezoelectric layer correspond to each other and are geometrically matched. The plurality of sensing units with different sizes are arranged according to a spiral-like path, and the wave crests and the wave troughs of sensitivity curves are mutually compensated and coupled; the imaging system is composed of a spiral array formed by the sensing assembly, a sound wave emission unit, a central processing module and a display device, and the array further comprises a sound impedance matching layer to improve the sound energy transmission efficiency. The response bandwidth of the sensing assembly is effectively widened, the detection sensitivity and precision of the imaging system are remarkably improved, and the method can be applied to target detection, position calibration and route planning, underwater acoustic communication transmission, fishery breeding monitoring, geological structure exploration and the like; and a certain reference is provided for exploration of light weight and informatization of future equipment.

The invention discloses a corrugated pipe-shaped soft body actuator and a hand rehabilitation training device. The actuator comprises a hollow corrugated pipe section; the first connector pipe section is connected with one end of the hollow corrugated pipe section; the wave height of the hollow corrugated pipe section has the maximum value and the minimum value in the circumferential direction, and the maximum value is larger than the minimum value. The projections of the outer contour of the wave crest structure and the outer contour of the wave trough structure of the hollow corrugated pipe section in the axial direction are two closed curves which are eccentrically arranged; the axial section where the wave height maximum value of the hollow corrugated pipe section is located is not coplanar with the axial section where the wave height minimum value of the hollow corrugated pipe section is located. The corrugated-pipe-shaped soft body actuator can achieve combination of telescopic deformation and bending deformation of the actuator under the unconstrained condition, and when the corrugated-pipe-shaped soft body actuator is used as a hand rehabilitation training device, interphalangeal unfolding and finger bending and straightening can be combined.

The utility model provides a slide seat with oil guide groove structures, the slide seat is arranged on a lower template and can slide back and forth on the lower template in a reciprocating manner, a plurality of oil guide groove structures are concavely arranged on the contact surface of the slide seat and the lower template, and the oil guide groove structures are used for accommodating lubricating oil. Each oil guide groove structure is provided with a first oil guide groove and two second oil guide grooves communicated with the first oil guide groove, the multiple first oil guide grooves are distributed in the contact surface in parallel, the first oil guide grooves are linear and extend in the front-back direction, and the second oil guide grooves are wavy; the two second oil guide grooves are arranged in a mirroring mode with the first oil guide groove communicating with the second oil guide grooves as the center, each second oil guide groove is provided with a wave crest end and a wave trough end, the wave crest ends are arranged away from the first oil guide grooves, and the wave trough ends communicate with the first oil guide grooves. The utility model further provides a die.

The invention discloses an intelligent flood prevention method for a water conservancy project, and relates to the technical field of water conservancy project flood prevention. Performing feature extraction of in-segment peak attenuation gradient, trough rise amplitude difference and change rhythm drift total value on the jump sequence map, and constructing a signal interference feature vector group to determine signal interference features; and based on the signal interference feature vector group, extracting a disturbance dimension, a disturbance intensity and a historical interference reproduction rate corresponding to the shielding disturbance as input parameters, and constructing a credibility identification variable set. In order to solve the problem that water level data continuously jumps and is easily misjudged as real data due to the fact that water surface sensing equipment is shielded by floating objects in intelligent flood prevention for hydraulic engineering, accurate identification, hierarchical management and control and dynamic scheduling correction of interference data are realized by constructing a jump map, an interference feature vector and a credibility evaluation system.

A drag chain with a corrugated bending radian comprises an upper cover and a lower cover which are buckled with each other, the upper cover and the lower cover are integrated corrugated hoses with wave crests and wave troughs alternately appearing to form corrugated contours, and the corrugated contours have flexibility and are flexibly bent towards the direction of the upper cover. The corrugated contours of the upper cover and the lower cover comprise side parts located on the two sides in the width direction and middle sections located on the side parts gradually, and the two ends of each middle section are bent gradually from the connecting positions of the side parts to the direction of the center line, so that the middle sections have radians protruding towards the direction of one side. According to the technical scheme, the protruding radians are arranged on the wave crests on the corrugated outline, so that when the drag chain is flexibly bent in the movement process, a space with a larger bending radian can be formed between every two connected wave crests, the radius of flexible bending can be reduced, and the flexibility of the drag chain is improved. Therefore, the bearing capacity and the tensile property of the drag chain can be improved.

The invention provides a ground material type detection method and equipment, which can be applied to the technical field of autonomous mobile equipment. The method comprises the following steps: transmitting ultrasonic waves to the ground, and receiving echoes of the ultrasonic waves to obtain an echo waveform diagram; the longitudinal axis of the echo waveform diagram is positively correlated with the echo intensity, and the transverse axis of the echo waveform diagram is positively correlated with the time; identifying wave troughs in the echo waveform graph; determining the number of echo groups in the echo waveform diagram according to the wave troughs; and determining a ground material type according to the number of the echo groups. The ground material type is detected through the number of the echo groups of the ultrasonic waves, and the detection accuracy of the ground material type can be improved. Moreover, only one ultrasonic sensor is needed to detect the type of the ground material, the occupied space is small, and the cost of the autonomous mobile equipment is reduced.

The invention discloses a hollow outer rotor single-channel winding type rotary transformer and system. The transformer comprises a stator, a rotor, an excitation winding, a sine signal winding and a cosine signal winding. The rotor is sleeved outside the stator; the rotor comprises magnetic conductive materials located at the two ends of the rotor, a gap is formed between the two magnetic conductive materials, and sine ripple structures are arranged on the surfaces, making contact with the gap, of the two magnetic conductive materials. The wave crests and the wave troughs of the two sine ripple structures are oppositely arranged; the excitation winding is arranged on the rotor; the sine signal winding and the cosine signal winding are arranged on the stator. The transformer has the advantages of being high in measurement precision and small in size.

The utility model relates to the technical field of packing, in particular to a corrugated packing combined structure for a water scrubber. The corrugated packing combined structure is formed by stacking or coiling corrugated packing, each corrugated packing comprises a wave crest, a wave trough and a wave surface, a hook-shaped structure is arranged on each wave surface, and the surface, with the largest surface area, of each hook-shaped structure is connected with the corresponding wave surface. The corrugated packing composite structure is small in gap, better in gas-liquid ratio uniformity during water spraying, not prone to displacement in the installation process and the use process, good in stability and longer in service life.

The invention discloses a spectrograph high-precision wavelength calibration method based on optical filter hardware interception, and the method comprises the steps: placing an optical filter in an interference light path, limiting the spectrum range in a hardware manner, and enabling a camera to directly collect an interference spectrum signal with a sharp boundary; extracting wave crest and wave trough positions of the interference spectrum signal, calculating a local half cycle and fitting to obtain a half cycle change curve; calculating a phase gradient to obtain a wavenumber gradient; solving a relative function of wave numbers through an integral accumulation mode; establishing a mapping relation between a pixel coordinate and a wavelength by combining cut-off wavelength information of the optical filter, and completing wavelength calibration of the spectrograph; performing interpolation resampling on the interference spectrum signal based on a calibration result; and Fourier transform is carried out on the re-sampled interference spectrum signal to obtain depth information. According to the invention, the problem that the existing calibration method depends on an expensive light source, and is insufficient in precision or high in complexity can be solved.

The invention provides a preparation method of a composite board with excellent interface bonding, which comprises the following steps: if the processing and using temperature of the composite board is less than or equal to 200 DEG C, polishing one side surface of a base material blank until the roughness is 0.02 T + 0.05 t + 0.5 CR <-5 >-0.02 T + 0.05 t + 0.5 CR, T is a preset heat treatment temperature unit of DEG C, t is a total heat treatment time unit of min, CR is a preset total compression ratio, and if multiple heat treatments are needed, T is a maximum value; if the processing and using temperature of the composite board is higher than 200 DEG C, the surface of one side of the base material blank is polished into a wave shape, the vertical distance between the wave crests and the wave troughs is 0.1 T-85-0.1 T-80, the unit is mm, the horizontal distance between the wave crests is 100-12.5 lnT-110-12.5 lnT, and the unit is cm. The surface of the base material blank is subjected to different treatments through different processing use temperatures, so that the bonding strength of the base material and the covering material is guaranteed.

The invention provides a method and system for measuring the side deformation degree and the girdling depth of a capacitor, and relates to the technical field of intelligent quality inspection, and the method comprises the steps: carrying out the background subtraction and image binarization of a side image of the capacitor, so as to obtain a binary image of the capacitor; carrying out segmented detection on the capacitance binary image by adopting a slope and curvature combined mode to obtain wave crest information and wave trough information of a side surface deformation area and a girdling area; and performing side deformation degree measurement according to the wave crest information and the wave trough information of the side deformation area, and performing girdling depth measurement according to the wave crest information and the wave trough information of the girdling area so as to obtain a side deformation degree measurement result and a girdling depth measurement result. The side deformation degree and the girdling depth of the capacitor are measured based on the machine vision technology, and the problems that the side deformation degree and the girdling depth of an existing capacitor are high in measurement cost and poor in measurement precision are solved.

The utility model discloses a curved surface belleville spring, the upper end surface and the lower end surface of the cross section of a belleville spring body are wave-shaped, the upper end surface of the cross section of the belleville spring body is provided with an odd number A of wave crests, wave troughs and the wave crests on the cross section of the belleville spring body are arc-shaped, and the radian radius R0 of the wave crests and the radian radius R0 of the wave troughs are the same. The ratio of the maximum compression amount h0 of the belleville spring body to the thickness t of the belleville spring body is larger than or equal to 1.6 and smaller than or equal to 3, the ratio of the outer diameter phi D to the inner diameter phi d of the belleville spring body 1 is larger than or equal to 1.8 and smaller than or equal to 3, and the ratio of the arc radius R0 of the wave, the peak and the trough to the thickness t of the belleville spring body is larger than or equal to 6 and smaller than or equal to 10. The stress distribution and the bearing characteristic are optimized through the structural design of the curved surface belleville spring, the stress concentration of the belleville spring is reduced, and the buffering capacity and the fatigue resistance of the spring are improved; and after the compression amount of the curved surface belleville spring reaches a certain amount, the rigidity tends to be constant rigidity, and stable pre-tightening force can be provided.

The present application belongs to the technical field of earthquake sandy soil liquefaction evaluation, and in particular relates to an evaluation data acquisition method for earthquake liquefaction potential evaluation and an earthquake liquefaction evaluation method, wherein the evaluation data acquisition method comprises the following steps: S1, acquiring a seismic displacement waveform or a strain waveform of a target site during an earthquake; S2, detecting a wave peak and a wave trough of each period of each component seismic displacement waveform or strain waveform, calculating a difference value between the wave peak and the wave trough, and comparing the difference value with a preset statistical significance threshold; and S3, obtaining a dynamic cyclic vibration number representing the driving strength of earthquake liquefaction based on period counting. The present application solves the technical defect that the prior art cannot accurately reflect the actual dynamic loading level of soil during an earthquake, and provides a measurement method for directly acquiring key physical parameters that can truly reflect the driving strength of earthquake liquefaction from displacement waveforms or strain waveforms and a liquefaction potential evaluation method.

Embodiments of the present application disclose an ultrasonic transducing assembly and an ultrasonic transducing array, which can improve the working bandwidth of the ultrasonic transducing assembly. The ultrasonic transducing assembly comprises a substrate, at least one first PMUT unit and at least one second PMUT unit, and the first PMUT unit and the second PMUT unit are located on the substrate. The cross-sectional shape of the first PMUT unit has a long axis and a short axis, and the cross-sectional shape of the second PMUT unit has a long axis and a short axis, and the cross sections are parallel to the substrate. The size of the first PMUT unit is different from the size of the second PMUT unit. The difference between the frequency corresponding to the wave peak position on the sensitivity curve of the first PMUT unit and the frequency corresponding to the wave trough position on the sensitivity curve of the second PMUT unit is less than a preset value, and / or the difference between the frequency corresponding to the wave trough position on the sensitivity curve of the first PMUT unit and the frequency corresponding to the wave peak position on the sensitivity curve of the second PMUT unit is less than a preset value.

The utility model discloses a filter assembly, filter device and air handling unit, filter assembly includes: sticky carbon structure, sticky carbon structure bends to form a plurality of crest portion and a plurality of trough portion, each crest portion and each trough portion extend along first direction, a plurality of crest portions and a plurality of trough portions are staggered along second direction, the plurality of crest parts and the plurality of trough parts jointly define a plurality of first through holes, and the first direction intersects with the second direction; the supporting piece is located on the other side of the thickness direction of the carbon adhering structure, and a plurality of second through holes are formed in the supporting piece. According to the filtering assembly disclosed by the utility model, the capability of filtering or adsorbing gas is improved, peculiar smell is also prevented from being generated in the filtering assembly, the use experience of a user is improved, and the use performance of the filtering assembly is improved.

A padding article includes a sheet formed according to a wave pattern to include a wave crest. A wave trough is connected to the wave crest. A first plurality of dimples is formed along either the wave crest or the wave trough. A cushion assembly and a packaging assembly are also disclosed.

The invention provides an anti-interference echo signal detection method and system for an ultrasonic flowmeter, and relates to the technical field of signal processing. Comprising the following steps: identifying wave crest positions and wave trough positions of a plurality of continuous waves in an ultrasonic echo signal, and determining time and amplitudes of the wave crest positions and the wave trough positions; calculating wave amplitudes of the plurality of waves, judging whether the wave amplitudes of the plurality of waves are all greater than an amplitude threshold, and if so, meeting the amplitude requirement; calculating wave crest frequencies and wave trough frequencies of the plurality of waves, judging whether differences between the wave crest frequencies and the wave trough frequencies of the plurality of waves and the frequency of the driving signal are within a set frequency width range or not, and if so, meeting the frequency requirement; the ultrasonic echo signals meeting the amplitude requirement and the frequency requirement at the same time serve as effective echo signals. According to the method, the echo signal is identified and positioned by taking the echo frequency and the echo amplitude as judgment conditions, so that the situations of signal failure and the like caused by abnormal deformation of the signal are reduced.

The present disclosure proposes a scroll compressor, comprising: a housing (100); the two scrolls (200 and 300) are contained in the shell (100), the scroll bodies of the two scrolls (200 and 300) extend along involutes respectively and are meshed with each other, and the scroll body of at least one scroll is provided with a sealing groove (340) recessed from the top face of the scroll body. The sealing groove (340) extends from an inner end wall (341) close to the circle center of the involute base circle to an outer end wall (342) far away from the circle center of the involute base circle along the involute, and is provided with a sealing strip (350) and a pre-tightening spring (360); the pre-tightening spring (360) is wave-shaped and has a plurality of wave crest portions (363) abutting against the bottom (351) of the sealing strip (350) and a plurality of wave trough portions (364) abutting against the bottom wall (344) of the sealing groove (340), and the spring stiffness of the pre-tightening spring (360) decreases in the direction from the inner end wall (341) to the outer end wall (342).

The invention relates to the technical field of tunnel monitoring, and discloses a device and method for monitoring deformation of an existing subway interval tunnel caused by pipe-jacking construction, and the device comprises an optical fiber which is laid on the arc surface of the inner wall of the tunnel in a snake-shaped wave shape, and the optical fiber is spread towards the two sides with the top of the tunnel as the center. And bending back and forth between the left and right side walls while extending longitudinally along the tunnel, so that the crest part is positioned on one side wall of the tunnel, the trough part is positioned on the other side wall of the tunnel, and the crest part and the trough part are flush in height in the cross section of the tunnel. The optical fiber is laid on the arc surface of the inner wall of the tunnel in a snakelike wave shape, radial deformation of the section of the tunnel is converted into axial strain of the optical fiber through wave geometry, and meanwhile the optical fiber extends in the longitudinal direction and can also sense longitudinal differential settlement.

The invention relates to a rapid identification method for a fiber bragg grating reflection center wavelength, and belongs to the technical field of fiber bragg grating sensor demodulation peak searching, and the method comprises the following steps: S1, building a fiber bragg grating reflection wavelength feature identification system; s2, collecting the spectral signals reflected by the fiber bragg grating for multiple times; s3, processing the spectral signals acquired for multiple times, and deriving the reflection waveform curve to obtain a slope curve corresponding to the reflection waveform curve of the fiber Bragg grating; s4, detecting wave crest and wave trough positions of the slope curve by using a centroid detection algorithm; and S5, obtaining the maximum slope point of the reflection waveform curve, namely the half-peak position of the reflection center wavelength.