182 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.

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 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 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 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 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.

The application discloses a coil layout optimization and pose estimation simulation model, relates to the technical fields of electromagnetic tracking, simulation modeling and electromagnetic layout optimization, and aims to realize optimal design of a transmitting coil spatial layout and high-precision pose calculation through high-fidelity numerical simulation data driving. Under the driving of specific excitation signals, a simulation engine utilizes ANSYS finite element analysis to pre-construct a global magnetic field fingerprint characteristic map of the transmitting coil, so as to replace a traditional magnetic dipole mathematical approximation model. In order to improve the scientificity of the coil layout, virtual magnetic field data generated by ANSYS is mapped into sensor sensing voltage prediction values, and residual errors are constructed with pose estimation values output by a calculation module; subsequently, the pose errors are used as feedback evaluation indexes to iteratively correct coil geometric arrangement parameters in the ANSYS model, and finally, a global optimal layout is obtained.

According to the magnetoelectric dipole antenna, the coaxial feed communication bandwidth is larger than 100%, and the technical problems that broadband impedance matching and high-frequency mismatching are achieved, and the stability of a feed structure is poor are solved. According to the antenna, a meandering seam bending type electric dipole and a stepped flaring type magnetic dipole are cooperatively matched, and a feed structure and a U-shaped reflector are combined to integrally form the magnetoelectric dipole antenna. A meandering seam is etched on a horizontal rectangular patch, a vertical patch is welded on the outer side of the horizontal rectangular patch to form a three-dimensional radiator, and the three-dimensional radiator and a stepped flaring type cavity structure magnetic dipole form a closed structure. The feed structure comprises a coaxial line and two bent copper sheets, thereby realizing direct current grounding and providing mechanical reinforcement. 3.7 GHz and 4.2 GHz resonance points are introduced to realize 104.8% of relative bandwidth, while the compact structure is maintained, the broadband coverage and stable radiation characteristics are realized, the long-term reliability in an outdoor complex environment is ensured by a stable feed structure, part of 5G communication signals in a Sub-6G frequency band can be effectively covered, and the antenna is suitable for various wireless communication systems.

The application relates to a radio frequency coil design method for transmit array spatial encoding imaging, and belongs to the technical field of magnetic resonance imaging. In view of the problems of low single-dimension coding efficiency, strong coupling interference between coils and nonlinear phase gradient of a 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 coil. Through optimization of the coil structure and decoupling design, the technical scheme achieves multi-dimensional efficient coding, high-precision phase gradient, strong anti-interference and system light weight, and is suitable for the portability and dynamic monitoring scene of low-field magnetic resonance.

The application discloses a three-dimensional positioning method and device based on scalar magnetic anomaly and related equipment, and the method comprises the following steps: acquiring two-dimensional scalar magnetic anomaly data, and the record points of the two-dimensional scalar magnetic anomaly data are uniformly distributed in a detection area; based on the two-dimensional scalar magnetic anomaly data, acquiring energy level distribution data of two-dimensional scalar magnetic anomaly in a two-dimensional space formed by each group of unit orthogonal bases, wherein the unit orthogonal bases are obtained by decomposing two-dimensional scalar magnetic anomaly data generated by a magnetic dipole of a target body at an arbitrary height; based on the energy level distribution data, determining a horizontal positioning result and a vertical positioning result of the target body. The application converts two-dimensional scalar magnetic anomaly distribution into two-dimensional energy distribution, improves the signal-to-noise ratio of data, and does not involve the vector magnetic moment information of the target body in the three-dimensional positioning process of the target body, is not affected by the magnetic moment, and can improve the positioning accuracy in the vertical direction.

The invention relates to the technical field of optical communication, in particular to a device and a method for testing isolation of a free space isolator. The test method comprises the following steps: determining a path for connecting each isolator single sheet according to the number of the isolator single sheets required to be segmented of the whole isolator sheet; preparing a magnet according to a magnetic dipole model or magnet magnetic field distribution simulation software, and determining a detection position of a required magnetic field intensity near the magnet; a light source and an optical power meter are arranged at the detection position, the light source corresponds to the output end of the isolator whole piece, and the optical power meter corresponds to the input end of the isolator whole piece; moving the whole magnet or isolator to enable the path to pass through the detection position in sequence; and determining the isolator single chip corresponding to the unqualified position according to the detection value of the optical power meter. By adopting the mode, the isolation degree of each area can be tested before the whole isolator is segmented, so that unqualified products after segmentation can be screened out, and the qualified rate of the free space isolator manufactured subsequently is ensured.

The invention discloses a short baseline constraint optimization positioning method based on a magnetic moment vector modulus ratio, a measurement array and a system, and belongs to the technical field of magnetic detection and positioning. The method comprises the following steps: firstly, constructing a regular triangular prism-shaped measurement array, collecting magnetic field vector data generated by a magnetic target at each vertex measurement point of the array, and calculating a magnetic field vector at a coordinate origin of the measurement array and a vector mode gradient of the magnetic field vector; the spatial position coordinates of the magnetic target are used as decision variables, a constraint optimization model used for magnetic dipole positioning solution is established, and the target function of the constraint optimization model is a magnetic moment vector modulus ratio function; solving the constraint optimization model by adopting an adaptive differential evolution dung beetle optimization algorithm to obtain an optimal spatial position coordinate of the magnetic target; and based on the optimal spatial position coordinates, performing inversion calculation on three components of the magnetic moment vector of the magnetic target. According to the invention, the space volume of the positioning system is reduced, the positioning system is relatively simple, and the positioning error caused by the uncertainty of magnetic conductivity is also eliminated.

This invention discloses a method and system for anomaly assessment of the magnetic field of a UAV. The method includes: acquiring magnetic field measurement data of the UAV through a three-axis fluxgate sensor array; estimating the number of magnetic dipoles and spatial orientation boundaries based on the UAV's structural design information; constructing magnetic dipole range constraints based on the number of magnetic dipoles and spatial orientation boundaries; obtaining the optimal magnetic dipole parameter set based on the magnetic dipole range constraints using a genetic algorithm; embedding the optimal magnetic dipole parameter set into a magnetic field calculation model; obtaining a magnetic field intensity distribution cloud map and a closed surface with isomagnetic induction intensity of the UAV's own magnetic field under a specific scenario through the magnetic field calculation model; and performing anomaly assessment of the UAV's own magnetic field based on the magnetic field intensity distribution cloud map and the closed surface. This invention improves the determinism of the inversion results by designing a constraint strategy based on the distribution characteristics of the UAV's own magnetic source and embedding it into a genetic algorithm, thereby achieving high-precision anomaly assessment of the magnetic field.

The application discloses a magnetic moment comparator device and a measuring method. The magnetic moment of a current-carrying standard coil is proportional to the magnetic field generated at a fixed distance on the axis, and according to the principle of equivalence between the magnetic dipole layer and the current-carrying coil in electromagnetism, the magnetic moment of the magnetic sample at the same position can be measured by the current-carrying standard coil when the spatial magnetic field can be accurately measured. The application designs a magnetic moment comparator in a magnetic shielding cylinder, uses an atomic magnetometer to measure the absolute magnetic field with high sensitivity, places a current-carrying standard coil at a distance r0 on one side of the atomic chamber along the background magnetic field direction, and the axis is parallel to the background magnetic field direction; the magnetic moment direction of the magnetic sample is parallel to the background magnetic field direction, when the magnetic sample is moved to the position of the atomic chamber at a distance r0 on the other side of the atomic chamber by a sample transmission rod, the current flowing into the standard coil is changed in real time under the condition that the background magnetic field remains unchanged, and then the magnetic moment of the magnetic sample is equal in size and opposite in direction to the magnetic moment of the current-carrying standard coil.

The application belongs to the field of satellite mobile communication, and specifically provides a wide-beam metal-resistant antenna for satellite communication to overcome the problem that communication is interrupted under the interference of a metal environment for the existing satellite communication antenna. The application adopts a design of laminated slot coupling feed, improves the back and forward radiation of the antenna through a metal reflector plate and a forward radiation plate to improve the gain, generates 90 degrees of self-phase shift through a Wilkinson power divider, feeds a rotationally symmetrical "H" type slot at the same time, introduces a metal aluminum ring to pre-compensate the metal environment, reduces the influence of the surrounding metal floor on the antenna, and the metal reflector plate and the conductive metal aluminum ring together form a magnetic dipole, which is complementary to the directional diagram of the feed plate as an electrode to widen the lobe and improve the gain at a low elevation angle. Furthermore, the application has the advantages of wide beam, good low-elevation circular polarization performance and metal resistance, and is more suitable for satellite communication in actual scenarios.

The application provides an arbitrary dimension magnetic anomaly gradient positioning method for buried target detection, comprising the following steps: an optimization function modeling step: constructing an arbitrary dimension magnetic anomaly gradient function based on a magnetic dipole model; an optimization solving step: obtaining the position and magnetic moment module value of a target object through a particle swarm optimization algorithm based on the arbitrary dimension magnetic anomaly gradient function; and a data fusion step: fusing multiple sensor information based on the position and magnetic moment module value of the target object to obtain the buried depth of the target object under cross-medium conditions.

The invention discloses an electromagnetic anomaly detection method based on tensor shrinkage and orthogonal basis function decomposition, and belongs to the technical field of magnetic detection and correction, and the method comprises the steps: enabling a metal target to be equivalent to a magnetic dipole, and building an AC radiation field model; then, deducing a magnetic gradient tensor of a metal target scattered field; next, taking the square of the reduced tensor of the scattering field as a detection quantity, and calculating a primary function of mutual orthogonality of the detection quantity; and finally, establishing an energy function to complete electromagnetic anomaly detection of the metal target. According to the invention, the non-ferromagnetic metal target in the space can be effectively detected based on the electromagnetic emission source, the signal-to-noise ratio of electromagnetic anomaly detection is improved, and the method is of great significance to detection of metal anomalous objects in anti-submarine, anti-mine, anti-landmine and other scenes.

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.