251 results about "Magnetic dipole" patented technology

The invention discloses a high-strength and high-toughness aluminum nitride ceramic and a preparation method thereof, and relates to the technical field of ceramics, a sol-gel method is adopted to coat the surface of aluminum nitride with a stable shell layer to form a core-shell structure, meanwhile, the low lattice mismatch rate of a core-shell interface is utilized to reduce thermal resistance, and toughness and thermal conductivity are both considered; according to the external magnetic field tape casting method, the magnetic dipole moment orientation principle is utilized, an external magnetic field is applied in the tape casting stage, the in-plane mechanical property is improved, and the fracture toughness is improved through the magnetism of aluminum nitride whiskers; a reinforcement is introduced to improve the mechanical property and corrosion resistance of the aluminum nitride ceramic material, multi-granularity powder is compounded, large-particle aluminum nitride powder is used as a sintering and heat-conducting framework material, and high activity provided by submicron particles is utilized to promote sintering, so that the sintering temperature of aluminum nitride can be remarkably reduced, and the performance is greatly improved; and the aluminum nitride substrate expands more application fields on a future packaging circuit.

The invention relates to the technical field of magnetic detection, in particular to a target positioning method based on geomagnetic anomaly and an axis frequency magnetic field. Comprising the following steps: S1, preparing before entering water; s2, approaching a target; s3, target detection: when no target appears, an observation signal is composed of an environment magnetic field, and the energy value of the part is very small; once the target appears, the energy of the observation signal can be continuously and obviously increased, when the energy value is greater than a preset judgment threshold, the target point is judged as a suspected target point, and if the suspected point is continuously detected for a specified time, the existence of the target is confirmed; s4, combined positioning: under a Kalman filtering framework, enabling the target to be equivalent to a magnetic dipole and an electric dipole, and correcting a position predicted by a target state equation by combining measurement equations of the two models, thereby realizing combined positioning of the target and obtaining more accurate target position information; and S5, verifying and outputting a positioning result. The method has the advantages of improving the positioning precision, enhancing the anti-interference capability and the like.

The invention discloses a magnetic source positioning method based on a spin-exchange relaxation-free atom magnetometer, and aims to provide a high-precision brand-new solution for magnetic source positioning in a near-zero magnetic environment by performing physical modeling and least square estimation on space magnetic field distribution of a target magnetic source. The magnetometer is enabled to be simultaneously sensitive to a three-axis magnetic field, a light absorption detection method is utilized to ensure that complete three-axis magnetic field information is obtained, and the sensitivity of the three axes reaches fT / Hz1 / 2 (1fT = 10 <-15 > T) magnitude. In the positioning process, the target magnetic source is abstracted into a physical model of the magnetic dipole, and the space magnetic field information generated by the target magnetic source is obtained through the atom magnetometer, so that the long-term stability of the magnetic source positioning process and the high precision of the positioning result can be ensured in the zero magnetic environment; therefore, a high-precision magnetic positioning technical means with great potential is provided for various application scenes such as paleomagnetic sample testing and magnetic source positioning in medical research, and technical progress and application expansion in related fields are expected to be promoted.

An antenna element, an antenna module, an antenna array and an electronic device. The antenna element (4) comprises electric dipoles (41), magnetic dipoles (42) and a feed unit (43). The current of the feed unit (43) is coupled to the magnetic dipoles (42), and is then directly transmitted to the electric dipoles (41) by the magnetic dipoles (42). Each pair of electric dipoles (41) comprises two first patches (411), each first patch (411) is of a closed loop structure, and the coupled current is transmitted along the contour of the first patch (411), thereby facilitating the lengthening of a transmission path of the coupled current. For the same transmission path length, the electric dipoles (41) of this structure have a smaller volume, which can reduce the volume of the antenna element (4). Each first patch (411) of the closed loop structure reduces the radiation area of an antenna to a certain extent, and reduces the coupling between antenna elements (4), so that the radiation gain of the antenna module (100) can be improved. Therefore, the antenna element (4) can improve the radiation gain of the antenna module (100) while making the antenna module (100) smaller. (FIG. 1)

The invention discloses a stomach tube tail end three-dimensional positioning method based on a high-precision permanent magnet mark and a flexible TMR array. The method comprises the following steps: disinfecting a stomach tube and a permanent magnet marker; the miniaturized permanent magnet marker is firmly installed at the front end of the stomach tube; reserving a mounting position at the front end of the stomach tube, and inserting the stomach tube into the esophagus of a patient through a nasal cavity or an oral cavity until the stomach tube reaches a preset position; flexible TMR sensor arrays in double-sided distribution are arranged in the chest area and the back area of the patient; according to magnetic field data detected by a TMR sensor array, coordinates of a permanent magnet marker in a sensor coordinate system are solved through magnetic dipole modeling and nonlinear optimization, a thoracic coordinate system transformation matrix is established, and three-dimensional position coordinates of the permanent magnet marker in a world coordinate system are determined; a magnetic dipole reverse solution positioning method is adopted, and meanwhile, the zero radiation exposure risk is ensured; spatial registration with an ultrasonic image is supported, and the positioning precision and the anti-interference capability are improved.

The invention discloses a cilia type magnetic tactile perception method for distributed force load. The size and direction of the distributed force load are calculated based on magnetic field distribution around magnetic cilia by using a force-magnetic coupling model; the magnetic cilia is composed of a flexible non-magnetic material segment and a flexible magnetic material segment, the flexible non-magnetic material end is fixed to the substrate, and the flexible magnetic material end is a free end; discretizing the magnetic cilia into a plurality of sections, wherein each section is regarded as a combined fragment of a plurality of magnetic dipoles; for any combined segment, superposing the magnetic fields of all the magnetic dipoles in the combined segment to obtain the magnetic field of the combined segment based on the superposing property of the magnetic fields; and the overall space magnetic field distribution of the magnetic cilia is obtained by superposing the magnetic fields of all the combined fragments based on the superposing property of the magnetic fields. The method has the advantages of high sensitivity, simple structure, strong anti-interference capability and the like, and is suitable for the fields of robot touch, medical micro-force detection, industrial precision measurement and the like.

The invention discloses a cilia type magnetic tactile perception method for concentrated force load. The size and direction of the concentrated force load are calculated based on magnetic field distribution around magnetic cilia by using a force-magnetic coupling model; the magnetic cilia is composed of a flexible non-magnetic material segment and a flexible magnetic material segment, the flexible non-magnetic material end is fixed to the substrate, and the flexible magnetic material end is a free end; discretizing the magnetic cilia into a plurality of sections, wherein each section is regarded as a magnetic dipole fragment; the overall space magnetic field distribution of the magnetic cilia is obtained by superposing the magnetic fields of all the magnetic dipole segments based on the superposing performance of the magnetic fields. The method has the advantages of high sensitivity, simple structure, strong anti-interference capability and the like, and is suitable for the fields of robot touch, medical micro-force detection, industrial precision measurement and the like.

The invention provides a wear coefficient correction method for a shield cutter, and relates to the technical field of wear monitoring, and the method comprises the steps: collecting a time sequence magnetic field signal obtained by a magnetic sensor array disposed on a non-rotating part of a shield tunneling machine, and synchronously obtaining a cutter angle coding signal; performing time-frequency conversion and filtering on the magnetic field signal to obtain a noise reduction time sequence signal; determining a geometric position sequence of each shield cutter in combination with the angle coding signals; based on the magnetic sensor pose, the tool position and the magnetic dipole model, theoretical magnetic field mapping between the tool and the sensor is constructed, and a system response matrix is generated; reconstructing an independent magnetic feature vector of each cutter to obtain an optimal feature set; generating a vector difference through comparison with a reference vector, inputting the vector difference into an abrasion identification model, obtaining the abrasion loss and type identification of each cutter, and correcting an abrasion coefficient; the method improves the wear recognition precision and reliability, and is suitable for tunnel construction under complex geological conditions.

The invention provides a multi-magnetic accurate positioning method based on APSO-LM fusion, and solves the technical contradictions that global search and local convergence are unbalanced and the resolving efficiency is low in the existing multi-magnetic accurate positioning technology. The method comprises the following steps: constructing a magnetic moment calibration module, selecting a sensor array calibration point, collecting magnetic field data, and calculating a precise magnetic moment amplitude based on a magnetic dipole model; an NSS-VMGT initial positioning result is input through a parameter initialization module, APSO and LM algorithm parameters are configured, and particle vectors are normalized; generating a particle swarm by using an APSO global search module, and iteratively screening a global optimal parameter as an LM initial value; calculating a residual error and a Jacobian matrix by means of an LM local refining module, and iteratively optimizing and outputting a magnetic source position and a magnetic moment; and the dynamic compensation module is used for calibrating clock skew and inhibiting environment interference. The device is realized based on STM32H743, and comprises a 7 * 7 lis2mdltr sensor array, a dual-chip data acquisition link, an APSO-LM algorithm hardware acceleration module and an upper computer interaction unit.

The invention belongs to the technical field related to nanometer material testing, and discloses a magnetic nanoparticle relaxation time detection method and an environmental parameter detection method, and the method comprises the following steps: applying an excitation magnetic field around a to-be-detected target mixed with magnetic nanoparticles; obtaining magnetization response generated by the magnetic nanoparticles in any direction of the magnetic field plane, and obtaining phase lag corresponding to any order harmonic term of the magnetization response; according to the function relationship between the phase lag corresponding to any harmonic term and the Brown relaxation time of the magnetic nanoparticles, solving and obtaining the Brown relaxation time of the magnetic nanoparticles; wherein the function relationship comprises a correction term introduced by magnetic dipole interaction of the magnetic nanoparticles. The magnetic dipole interaction among the magnetic nanoparticles is introduced, relaxation time detection of particle space distribution under an external magnetic field is corrected, the interference of the magnetic dipole interaction on the magnetic nanoparticle Brown relaxation time detection process can be effectively reduced, and accurate estimation of the magnetic nanoparticle Brown relaxation time is realized.

The invention discloses a broadband circularly polarized magnetoelectric dipole antenna with superposed Ka-band radiation modes, and belongs to the field of radio frequency front-end devices. The antenna is composed of an electric dipole patch composed of a rectangular patch and a stepped patch, a magnetic dipole radiator composed of four metal columns, an H-shaped slotted coupling floor, a feeder line, coaxial feed metal columns, an SIW structure, a metal ground backboard, an upper dielectric substrate, a lower dielectric substrate and a pp bonding layer, an antenna unit is subjected to 4 * 4 arraying, and the circularly polarized radiation performance of the antenna unit is verified. According to the invention, the circularly polarized wave beam range is wide, and the axial ratio bandwidth is 3GHz to cover the complete working frequency band. After the array is formed, the active S parameters of the array elements are well matched, and the excellent axial ratio performance is still achieved during beam scanning.

The invention relates to a radio frequency coil design method for transmitting array space coding imaging, and belongs to the technical field of magnetic resonance imaging. Aiming at the problems of low single-dimensional coding efficiency, strong coupling interference among coils and nonlinear phase gradient in the traditional TRASE technology, axial and radial coding coils are designed based on a target field method and a magnetic dipole method, two-dimensional radio frequency phase coding is realized through reverse current solenoid decoupling combination, and excitation and signal receiving are realized in combination with a saddle-shaped coil. According to the technical scheme, by optimizing the coil structure and the decoupling design, multi-dimensional efficient coding, high-precision phase gradient, strong anti-interference and light system weight are achieved, and the method is suitable for portable and dynamic monitoring scenes of low-field magnetic resonance.

The invention provides an indoor local magnetic field modeling method and device based on a magnetic source equivalence principle, and belongs to the technical field of indoor localization, and the method comprises the steps: collecting the data of a three-axis magnetometer in a space range through an array type magnetic sensor, and obtaining the original measurement information of an indoor magnetic field; based on a magnetic source equivalence principle, an indoor magnetic field is modeled into an equivalent magnetic dipole model consisting of a plurality of equivalent magnetic dipoles, and a magnetic field generated by the model is consistent with a real magnetic field in an observation area by setting magnetic moment and position parameters of the magnetic dipoles; according to the measured value of the array type magnetic sensor, an observation model is established in combination with an equivalent magnetic dipole model and used for describing the relation between the measured value and model parameters; through a nonlinear least square optimization method, parameters of the equivalent magnetic dipole model are solved according to the observation model, the equivalent magnetic dipole model of the indoor magnetic field is obtained, and the parameters comprise the magnetic moment and the position of the magnetic dipole. The precision and the reliability of the model are remarkably improved.

The invention discloses a magnetic field calculation method and device for a magnetic dipole and a storage medium, and relates to the technical field of magnetic field calculation, and the method comprises the steps: calculating a model of first magnetic induction intensity at the center of the magnetic dipole, a model of target magnetic induction intensity at a target point, and a model of second magnetic induction intensity at the center of the magnetic dipole; polynomial fitting is carried out on the change relation between the target point and the first position vector of the target point relative to the center of the magnetic dipole to obtain a first relation function; determining a model of the target magnetic induction intensity at the target point according to the first relation function; polynomial fitting is carried out on the change relation between a second position vector corresponding to the second magnetic induction intensity and the vector direction of the second position vector, and a second relation function is obtained; determining the target direction of the vector of the magnetic induction intensity of the target point according to the second relation function; and determining the target magnetic induction intensity of the target point according to the model of the target magnetic induction intensity and the target direction. According to the invention, the magnetic induction intensity of the magnetic dipole can be accurately calculated.

The invention discloses a dual-polarization filtering integrated antenna and a manufacturing method, and relates to the technical field of communication, the dual-polarization filtering integrated antenna comprises an antenna assembly and a filtering assembly, the antenna assembly comprises a substrate, a grounding plate and two groups of radiation units, the grounding plate is arranged at the first end of the substrate, and the filtering assembly is arranged at the second end of the substrate; each radiation unit comprises an electric dipole, a magnetic dipole and a feed part, the magnetic dipole comprises two single walls, each single wall comprises a plurality of metal columns, the feed part is arranged at the second end of the substrate, the electric dipole is arranged in the horizontal direction and located between the first end and the second end, and the metal columns are arranged at intervals and form an electromagnetic shielding cavity; the filtering assembly is arranged between the electric dipole and the first end and is positioned in the electromagnetic shielding cavity; the filtering assembly comprises a filter, a vertical transmission line and an improved structure; the filter comprises a plurality of capacitors and inductors; according to the technical scheme provided by the invention, the limitation of contradiction between the structural integration level and the electromagnetic performance in the conventional filtering antenna design can be broken through.

A single-layer broadband vertically polarized endfire magnetoelectric dipole (ME-dipole) antenna and an antenna array. The main radiator of this antenna is a substrate-integrated closed loop, which consists of two horizontal metallic strips printed on the upper and lower surfaces of substrate and a pair of vertical metallic vias. Excited by a double-sided parallel-strip line at the center of the loop, the metallic vias function as electric dipoles while the entire loop aperture works as magnetic dipole. To facilitate integration, this magnetoelectric dipole loop antenna is fed by an open-ended substrate integrated waveguide (SIW), which also works as a backed cavity to enhance the front-to-back ratio. Moreover, rectangular slots are etched at the edges of the SIW aperture to further improve the front-to-back ratio and also the cross-polarization performance. Thus, a vertically polarized endfire ME-dipole loop antenna with a low-profile structure, broad bandwidth, and stable radiation performance is achieved.

The invention discloses a two-dimensional motion trail tracking device based on permanent magnet positioning. The two-dimensional motion trail tracking device comprises an induction positioning plate, a signal acquisition module, a data transmission interface, a position calculation module and a display device, a three-axis magnetic sensor array is arranged on an induction positioning plate, magnetic field changes during movement of a permanent magnet are collected in real time, the three-dimensional position of the permanent magnet is inversed in combination with a magnetic dipole model, and the positioning precision is improved through an adaptive weighted fusion algorithm for multi-point position estimation. The signals are transmitted to display equipment after being processed, so that real-time drawing and physical quantity analysis of a motion track are realized; the permanent magnet serves as a passive projectile, power supply is not needed, and trajectory tracking of various motion modes such as horizontal projectile, free falling and simple pendulum can be achieved by matching with an optional auxiliary module. Through the synergistic effect of the passive permanent magnet and the magnetic sensor array, maintenance-free and high-precision real-time tracking and visual analysis of a two-dimensional motion track in a middle school physical experiment are realized.

The invention relates to an autonomous docking wireless charging method for an underwater robot, and the method comprises the steps: enabling the underwater robot to monitor the state of a battery in real time through a battery management module, and triggering a charging mode when the electric quantity is detected to be lower than a preset low electric quantity threshold value; when the underwater robot moves to a preset to-be-charged area near the charging base station, magnetic field gradient data and motion state data of the underwater robot are collected, and three-dimensional coordinates and attitude angles of the underwater robot relative to the magnetic dipole beacons of the charging base station are calculated; calculating a position deviation between a charging coil of the underwater robot and a charging base station coil according to the three-dimensional coordinate and the attitude angle; after the position of the underwater robot is adjusted, the underwater robot is driven to be in charging butt joint with the charging base station, and a charging program is started; and monitoring the charging process in real time until the electric quantity of the underwater robot reaches the preset charging electric quantity. According to the invention, charging is autonomously triggered through electric quantity monitoring, accurate docking in a complex environment is realized through magnetic field gradient positioning, and efficient charging is ensured.

The invention relates to a planar end-fire dual-frequency circularly polarized antenna with a small frequency ratio, which comprises a first magnetic dipole unit used for providing a vertical polarization component, and the first magnetic dipole unit comprises a medium, a first patch assembly, a first short circuit assembly and a feed end, the first patch assembly and the first short circuit assembly form a first cavity; the feed end is arranged on the first patch assembly; the second electric dipole unit comprises a first folding structure and a second folding structure, the second folding structure is a reverse folding structure of the first folding structure, and the second folding structure and the first folding structure form a complementary structure at the tail end. According to the invention, the structure is simple, the requirements of circular polarization phases of two frequency bands can be met at the same time, and the design complexity and the processing and manufacturing cost are greatly reduced; the complementary structure of the folded electric dipole tail end structure and the reverse extension branch knot can realize a small frequency ratio of about 1.3, and has the advantages of high gain and wide impedance bandwidth at high frequency.

The embodiment of the invention provides a spacecraft multi-layer near field method magnetic moment calculation method and device, and the method comprises the steps: determining the characteristics of a spacecraft, and determining the experiment arrangement of a magnetometer based on the characteristics of the spacecraft; wherein the magnetometer experiment arrangement comprises at least two layers; determining a magnetic moment conversion matrix based on magnetometer experimental arrangement; determining a magnetic moment result through a multi-layer near field method based on magnetometer experimental arrangement; a magnetic moment measurement is determined based on the magnetic moment conversion matrix and the magnetic moment result. Based on the multilayer near-field method and the magnetic dipole magnetic field model, optimization of the spacecraft multilayer near-field method magnetic moment calculation method can be realized, so that the magnetic characteristics of the spacecraft can be evaluated.

The invention discloses a magnetoencephalogram-based epilepsy lesion positioning method and system and a medium, and relates to the technical field of artificial intelligence, and the method comprises the steps: carrying out the preprocessing of a structure image of a patient, carrying out the registration with the magnetoencephalogram of the patient, carrying out the grid division of a cerebral cortex region based on the preprocessed structure image and a registration result, and obtaining a forward model of the patient; performing preprocessing and spine wave detection on the magnetoencephalogram to obtain a spine wave time point sequence; based on the forward model and the ratchet wave time point sequence, using a magnetic dipole algorithm to calculate a source coordinate and a source direction of a ratchet wave time point, and classifying the ratchet wave time point sequence according to the source coordinate and the source direction to obtain a clustering result; calculating the source coordinate and the source direction of the class center of each class in the clustering result by using a magnetic dipole algorithm; generating a clinical report of the patient; according to the positioning method, the problems of large epilepsy diagnosis difference and error proneness caused by level difference of different doctors are solved, and the epilepsy focus position can be quickly determined.

The invention provides a magnetocardiogram dipole center track parameter determination system. The system comprises an acquisition device, a generation device, a determination device and a calculation device. Wherein the acquisition device is used for acquiring a magnetocardiogram data set of a target wave band in a target magnetocardiogram data set; the generating device is used for generating a target isomagnetic map of the target wave band based on the magnetocardiogram data set of the target wave band; the determining device is used for determining a target dipole center pixel point set of a target wave band based on the dipole position of each frame of isomagnetic map in the target isomagnetic map; and the calculation device is used for calculating the center track parameters of the target dipole based on the center pixel point set of the target dipole and a pre-created standard center track distribution map. Therefore, the change rule of the center of the magnetocardiogram dipole can be accurately and intuitively described, and the distribution states of the dipoles in different wave bands can be accurately quantified through the calculated center track parameters of the dipoles.

The invention provides an annular segmented iron yoke center magnetic field uniformity optimization method and device, relates to the technical field of superconducting electrical iron yokes, and solves the technical problem that the uniformity of a superconducting magnet center magnetic field is difficult to improve in the prior art. The method specifically comprises the following steps: acquiring physical basic parameters of the superconducting magnet; establishing a two-dimensional axisymmetric calculation model, determining radial and axial calculation ranges, and generating a two-dimensional grid coordinate matrix; calculating an initial static magnetic field by using the two-dimensional grid coordinate matrix based on the Biot-Savart law and the axial symmetry characteristic; constructing an annular yoke multi-parameter optimization problem, and performing global parameter search by adopting a genetic algorithm to obtain yoke optimization parameters; based on the magnetic dipole theory and the saturation characteristic of the ferromagnetic material, a correction model of the yoke to the magnetic field is established by combining yoke optimization parameters, an additional magnetic field generated by the yoke is calculated, the additional magnetic field and the initial static magnetic field are superposed, and the total magnetic field intensity is obtained. The method is used for optimizing the uniformity of the iron yoke center magnetic field.

A magneto-electric dipole antenna array includes a substrate and at least one antenna unit. Each of the at least one antenna unit includes an electric-dipole component, a magnetic-dipole component, a first feeding probe, a second feeding probe and a stripline. The electric-dipole component is disposed on an upper surface of the substrate. The magnetic-dipole component is disposed in the substrate and between the upper surface and a lower surface of the substrate, and is electrically connected to the electric-dipole component. The first feeding probe is disposed on the upper surface of the substrate for vertical polarization. The second feeding probe is disposed in the substrate and between the upper surface and the lower surface of the substrate for horizontal polarization. The stripline is disposed in the substrate and between the first feeding probe and the second feeding probe for capacitive coupling.

The invention discloses an ultra-wideband miniaturized vertical polarization horizontal omnidirectional radiation antenna, and belongs to the technical field of antenna engineering and wireless communication. The antenna comprises a vertical polarization radiator, a metal top cap, a parasitic metal column, a metal floor and a polarization surface, wherein the vertical polarization radiator is composed of four miniaturized Vivaldi antennas which are placed towards the end-fire direction; the metal top cap and the metal floor are respectively located above and below the radiator, the polarization surface surrounds the periphery of the radiator, and two ends of the parasitic metal column are respectively connected with the metal top cap and the metal floor. The miniature Vivaldi antenna is adopted to form the radiator, so that the problem of distortion of a high-frequency radiation pattern caused by the size of an ultra-wideband antenna is solved; a low-frequency magnetic dipole radiation mode is formed by using the parasitic metal columns, the metal top caps and the metal floor, and the low-frequency bandwidth is expanded. On the basis of miniaturization, the antenna provided by the invention can realize S11lt in 1-6GHz; and vertical polarization horizontal omnidirectional radiation of-10dB is realized, and the out-of-roundness of an omnidirectional radiation pattern is less than 3dB.

A method for operating an electromagnetic coilgun system, the method comprising: an electromagnetic coilgun comprising: a barrel and a longitudinally extended electrical excitation coil; wherein the electrical excitation coil circumferentially surrounds a bore of the barrel, energizing the electrical excitation coil to produce a steady-state magnetic field within and around the bore of the barrel, the steady-state magnetic field extending along a longitudinal axis of the barrel; loading the barrel with a magnetic dipole projectile at a breech end of the barrel, wherein the loaded magnetic dipole projectile is oriented with a first magnetic dipole moment aligned to a magnetic field orientation of the steady state magnetic field; and firing the magnetic dipole projectile by magnetically propelling the magnetic dipole along the longitudinal axis of the bore by a magnetic force produced by the steady-state magnetic field within and around the bore of the barrel.

The invention relates to the technical field of bolt fracture detection, and provides a wind generating set bolt fracture detection method and device, and the method comprises the steps: obtaining a surrounding magnetic field signal of a to-be-detected bolt; correcting the detected magnetic field signal based on the geomagnetic field to obtain a corrected magnetic field value; on the basis of the current corrected magnetic field value, the magnetic dipole intensity change gradient of the current moment relative to the previous moment is calculated, and when the magnetic dipole intensity change gradient exceeds a set value, it is judged that an abnormal defect occurs; and when the abnormal defect exists, for the current corrected magnetic field value, based on the obtained frequency spectrum energy ratio, calculating fracture feature extraction and diagnosis, and obtaining an abnormal expansion stage of the current defect. By collecting and correcting a magnetic field signal, calculating a magnetic dipole intensity change gradient to identify abnormity, and then combining a frequency spectrum energy ratio to diagnose a fracture stage, early online monitoring of bolt fracture is realized. The method has high sensitivity and strong anti-interference capability, and is suitable for intelligent monitoring in a wind power environment.

The invention provides a pressing plate state monitoring method and system based on magnetic induction, and relates to the technical field of pressing plate state monitoring, and the method comprises the steps: collecting the magnetic induction data of each pressing plate through a collection unit, and uploading the magnetic induction data to a data processing unit; removing environmental electromagnetic noise in the magnetic induction data based on the intrinsic characteristics of the magnetic field rotation; enabling each pressing plate to be equivalent to a magnetic dipole, and calculating the interference field intensity of the remaining pressing plates on the target pressing plate; eliminating interference field intensity from the magnetic induction data of the target pressing plate through an inverse coupling operator, and extracting an independent magnetic field component of the target pressing plate; according to the independent magnetic field component, the switching state of the target pressing plate is determined based on a threshold value method, and the switching state comprises a closed state and an open state; and outputting the on-off state to complete the state monitoring of the pressing plate. Even in a complex electromagnetic environment, the on-off state of the pressing plate can still be accurately monitored, and the safety risk and the misjudgment rate are reduced.

The present application relates to the technical field of antenna, in particular to a kind of flat end-fire dual-frequency circularly polarized antenna, including flat microstrip magnetic dipole, delay line, electric dipole with reverse elongated branch and feed coaxial conductor.Flat microstrip magnetic dipole forms closed current path by three short-circuit edges, and open-circuit edge is connected to the delay line arranged along the first direction.Electric dipole with reverse elongated branch includes the first part of electric dipole reversely arranged along the second direction, the second part of electric dipole forwardly arranged along the second direction, the first part of narrow-width reverse elongated branch forwardly arranged along the second direction and the second part of narrow-width reverse elongated branch reversely arranged along the second direction, wherein electric dipole with reverse elongated branch forms symmetrical structure by mirror image layout.Feed coaxial conductor is connected to flat microstrip magnetic dipole, and excites electric dipole to generate phase difference.The present application realizes receiving 2.46GHz and 5.58GHz signals simultaneously.

This invention discloses a method and system for magnet pose estimation based on magnetic dipole constraints. The method includes estimating the initial orientation and position of the magnet based on the triaxial magnetic field vectors measured by each magnetic sensor in a magnetic sensor array to determine the initial estimated orientation unit vector and initial estimated position of the magnet; iteratively solving the initial pose state parameters of the magnet using a nonlinear optimization algorithm based on a magnetic dipole model to obtain the final estimated orientation unit vector; obtaining the position residual and orientation residual using a pre-trained residual neural network model; and compensating the initial estimated position and the final estimated orientation unit vector based on the position residual and orientation residual to obtain the final magnet pose estimation result composed of the magnet orientation. This invention aims to overcome the influence of initial value deviation, sensor error, and environmental interference factors, improve robustness and generalization ability in complex environments, and meet the high-precision pose detection requirements of magnetic positioning.