92 results about "Helmholtz coil" patented technology

The invention relates to the technical field of micro-nano robots, and provides a motion control method and system for a magnetic control micro-nano robot carrying medicine in a simulation environment, and the method comprises the steps: obtaining a motion image of a magnetic control silicon dioxide-based micro-nano robot cluster in the simulation environment in real time; according to a preset transportation task, the current state of the micro-nano robot cluster is judged; based on the current state of the micro-nano robot cluster, establishing a magnetic field generated by the micro-nano robot cluster and the three-dimensional Helmholtz coil, a fluid resistance field of a simulation environment and a dynamic model of a simulation environment channel boundary condition; and based on the motion image acquired in real time, using a deep learning model to identify real-time pose information of the micro-nano robot cluster and the simulated environment channel boundary information, and using a path planning algorithm to perform trajectory planning according to the real-time pose information and the simulated environment channel boundary information. And the magnetic field is adjusted to control the movement of the micro-nano robot cluster.

The invention discloses a Helmholtz coil material lightning magnetic field shielding performance measuring device, which comprises a magnetic field generation device, a shielding test box is arranged in a magnetic field coverage range of the magnetic field generation device, an open hole is formed in the shielding test box, and the open hole enables a magnetic line of force of the magnetic field generation device to transversely penetrate through the shielding test box. The shielding test box is internally provided with the signal measurement unit, the signal measurement unit measures the magnetic field in the shielding test box, the lightning stroke magnetic field environment is accurately simulated, and the repeatability and accuracy of the shielding performance test are improved. The invention further discloses a method for measuring the lightning magnetic field shielding performance of the Helmholtz coil material, the lightning magnetic field shielding performance of the measured shielding material is measured by applying the device for measuring the lightning magnetic field shielding performance of the Helmholtz coil material, and the problem that traditional measurement is poor in accuracy is effectively solved.

The application discloses a geomagnetic vector measurement system compensation method based on a three-dimensional helmholtz coil, and steps include: S01. Constructing a geomagnetic vector measurement system interference magnetic field compensation model; S02. Placing the geomagnetic vector measurement system in the center region of the three-dimensional helmholtz coil, and generating magnetic field data of different directions and different sizes through the three-dimensional helmholtz coil, so as to obtain multiple groups of measurement data, wherein the measurement data include output values of three-axis magnetic field sensors, true values generated by the three-dimensional helmholtz coil and a change rate of the true values generated by the three-dimensional helmholtz coil with time; S03. Obtaining an error model equation group according to the data obtained in the step S02 and the geomagnetic vector measurement system interference magnetic field compensation model; and S04. Solving parameters in the error model equation group, and compensating the magnetic interference field of the geomagnetic vector measurement system by using the solved parameters. The application has the advantages of simple operation, low cost, high compensation precision, strong flexibility and the like.

The invention provides an electromagnetic field constraint system and constraint method for a CO2 laser amplifier, and the system comprises a spiral electrode which is wound on a discharge tube of the CO2 laser amplifier, the spiral electrode comprises a first DC positive electrode, a radio frequency positive electrode, a second DC positive electrode and a ground electrode which are sequentially and adjacently arranged, and the current flows through the first DC positive electrode in the electric field direction from the first DC positive electrode to the ground electrode. The electric field direction of the current from the second direct current positive electrode to the ground electrode is partially perpendicular to the electric field direction of the current from the radio frequency positive electrode to the ground electrode; the CO2 laser amplifier discharge tube and the Helmholtz coil are coaxially arranged, and the magnetic field direction of the Helmholtz coil is perpendicular to the electric field direction from the radio frequency positive electrode to the ground electrode. In the discharge area of the CO2 laser amplifier, the strong electromagnetic field restraint system is adopted, the vertical alternating high-voltage electric field and the vertical alternating high-voltage magnetic field are used for restraining plasma movement, the electro-optical conversion efficiency can reach about 20%, the CO2 laser power can be effectively improved, and the arc discharge problem under the high radio frequency power injection condition is avoided.

The invention discloses an array coil excitation coupling eddy current detection probe, system and method and a related device, and relates to the technical field of nondestructive testing. The probe comprises a double-coil excitation module and a sensing module; the double-coil excitation module comprises two semicircular Helmholtz coils; the two semicircular Helmholtz coils are symmetrically arranged, are parallel and coaxial, and are electrified with alternating-current excitation current with the same direction, the same frequency and the same phase; the distance between the two semicircular Helmholtz coils is adjustable; and the sensing module is arranged in the central area of the two semicircular Helmholtz coils and is used for detecting the magnetic field change caused by the eddy current field at the defect. According to the invention, the detection precision of pipeline corrosion, cracks and composite defects can be improved.

The invention provides a method for detecting the residual magnetic quantity of a permanent magnetic ferrite magnetic shoe. The method comprises the following steps: carrying out surface cleaning treatment on a permanent magnetic ferrite magnetic shoe to be detected; measuring the volume of the magnetic tile; peelable soft magnetic auxiliary layers are uniformly coated on the inner cambered surface, the outer cambered surface and the bottoms and the side walls of the grooves at the two ends of the magnetic tile, the relative permeability of the soft magnetic auxiliary layers is 10-100 times that of the magnetic tile body, and the spraying thickness is 0.2-0.6 mm; after the soft magnetic auxiliary layer is naturally aired, performing constant-temperature treatment on the magnetic tile; the magnetic shoe is placed in the center of a magnetizing coil, saturation magnetizing is carried out, and the magnetizing direction is consistent with the thickness direction of the magnetic shoe; stripping the soft magnetic auxiliary layer after magnetizing; a Helmholtz coil method is adopted to measure the magnetic flux of the magnetic shoe, and volume data is combined to convert the residual magnetic quantity.

The invention provides a three-axis coil error parameter identification method and device based on Kalman filtering, a medium and electronic equipment, and belongs to the technical field of motor control. According to the method, an error parameter identification model of a three-axis Helmholtz coil under the condition that a single-group coil offset error and a three-axis non-orthogonal error are superposed is constructed, and interference parameters in the error parameter identification model are identified by adopting a Kalman algorithm; according to identification interference parameters obtained through identification, a central uniform region vector magnetic field of the same three-axis Helmholtz coil under all current conditions is obtained through calculation; the method can effectively solve the problem that a traditional least square method or a neural network method is low in reliability of magnetic field simulation of the three-axis Helmholtz coil, magnetic field calculation errors caused by interference coefficient errors of the three-axis Helmholtz coil are remarkably reduced, and the identification accuracy is greatly improved.

The invention relates to an amorphous alloy wire continuous annealing device and method based on an alternating load auxiliary magnetic field. In magnetic field equipment of the device, a transverse Helmholtz coil transversely surrounds the periphery of a heat treatment furnace, the axial direction of the transverse Helmholtz coil is perpendicular to the wire penetrating direction, and a longitudinal Helmholtz coil longitudinally surrounds the periphery of the heat treatment furnace, and the axial direction of the longitudinal Helmholtz coil is parallel to the wire penetrating direction; in the heat treatment furnace, a hearth is arranged in a furnace box, and heating equipment is arranged on the hearth; in the alternating load equipment, a clamp is arranged on a three-dimensional combined table to clamp the amorphous alloy wire, and the tensile load is detected; in the winding device, a wire feeding roller winds the amorphous alloy wire and feeds the wire to the heat treatment furnace before annealing is started, after the amorphous alloy wire is clamped by the alternating load devices on the two sides, annealing is conducted under the conditions of a dynamic magnetic field and alternating loads, and a wire winding motor drives a wire winding roller to complete wire winding. Compared with the prior art, isotropic release of an internal stress field of the amorphous alloy wire is effectively promoted, and the amorphous alloy wire is better designed for materials with specific magnetic anisotropy requirements.

The utility model discloses a device for measuring two-dimensional magnetic induction intensity on an axial plane of a Helmholtz coil, and belongs to the technical field of electronic components. The device comprises a two-dimensional Hall probe, a stepping motor guide rail moving circuit and a high-precision voltage acquisition module, wherein the two-dimensional Hall probe consists of a two-dimensional Hall probe mounting base and two linear Hall sensors which are orthogonally mounted on the two-dimensional Hall probe mounting base; the stepping motor guide rail moving circuit and the high-precision voltage acquisition module are connected with the two-dimensional Hall probe; two ends of the high-precision voltage acquisition module are respectively connected with the two-dimensional Hall probe and the computer. According to the utility model, the symmetrical distribution characteristic of the Helmholtz coil magnetic field is utilized, the two-dimensional Hall probe is designed by using the two mutually orthogonal Hall sensors, and the three-dimensional space magnetic field distribution is reflected by measuring the two-dimensional magnetic field of the 1 / 4 axis plane of the Helmholtz coil; the high-precision voltage acquisition module is designed based on the single-chip microcomputer, so that measurement errors are effectively Compared with an existing device of the same type, measurement is easier and more convenient, experimental data processing is easier and more intelligent, and the expandability of the device is higher.

The invention discloses a bionic camouflage briefcase with an electromagnetic emission function, the bionic camouflage briefcase comprises an outer bionic structure, a middle layer and an inner layer structure, the outer bionic structure comprises a rotatable handle and a layered shell, and the handle is internally provided with a firing button, an emission mode selection button and a fingerprint unlocking device; the inner layer control area comprises a laser rapid aiming device; the middle layer comprises a pulse transmitting device and a pulse energy storage device, the pulse transmitting device is composed of multiple stages of Helmholtz coils in an array mode, the pulse energy storage device is composed of multiple pulse capacitors in an array mode, the pulse capacitors and the multiple stages of Helmholtz coils are connected in parallel to provide transient electric energy, and a transmitting tube is arranged on one side of each stage of Helmholtz coil; unification of camouflage and functionality is realized, the concealment is high, and the exposure risk is reduced; and a multiple safety control mechanism is adopted, so that false triggering and unauthorized use are prevented.

This invention discloses an anti-clogging biofiltration device coupled with a microbial fuel cell, applied in the field of biofiltration technology. It includes: a biofilter consisting of a porous media coarse filter layer, a cathode region, and an anode region arranged sequentially from top to bottom; a Helmholtz coil array deployed around the biofilter; and an external circuit that, together with the anode and cathode regions, constitutes the microbial fuel cell. The microbial fuel cell provides self-sufficient power to the cathode region, anode region, and Helmholtz coil array for anti-clogging biofiltration. This invention effectively solves the problems of accumulated clogging in EPS (expanded power filters) and the inability to clean the bottom filter media, and realizes self-generated electricity for the microbial fuel cell.

The invention relates to the field of biomedical research, and discloses a controllable magnetic field generation device which comprises a magnetic field generation device and a heat effect comparison device which are separated through a heat insulation plate. The magnetic field generation device and the heat effect comparison device comprise a magnetic field control table and a Helmholtz coil group mounted above the magnetic field control table; a transverse guide rod penetrates through the center of the movable base on the left side and the right side above the magnetic field control table, symmetrical transverse screws are arranged on the surfaces of the two ends of the transverse guide rod, the transverse screws are screwed to the center of the movable base through threads, and an adjusting rotary handle is fixedly connected to the end of the transverse guide rod. Compared with the prior art, the device has the advantages of concentrated and stable magnetic field intensity, convenience in magnetic field type regulation and control, weak heat effect and the like, and solves a series of problems of poor magnetic field uniformity, inconvenience in magnetic field type regulation and control, great influence of heat effect on experiments and the like.

The application provides a kind of magnetic shielding assembly shielding effectiveness evaluation method and device, it is related to magnetic shielding assembly shielding effectiveness evaluation technical field.Magnetic shielding assembly is placed in the axis center of helmholtz coil, and evaluation method includes: in the case where helmholtz coil is unloaded, with first set step, the magnetic field value inside N magnetic shielding assembly is measured, and unloaded magnetic field value is obtained;Control constant current source output current, so that helmholtz coil generates working magnetic field;In the case where helmholtz coil generates working magnetic field, first set step is measured again, and the magnetic field value inside N magnetic shielding assembly is obtained, and loading magnetic field value is obtained;According to the unloaded magnetic field value and loading magnetic field value of the same position of magnetic shielding assembly, the internal magnetic field difference value of magnetic shielding assembly is calculated;According to internal magnetic field difference value and working magnetic field, the shielding effectiveness value of magnetic shielding assembly is calculated, to determine whether the shielding effectiveness of magnetic shielding assembly is qualified.The application can realize efficient and accurate evaluation before magnetic shielding assembly assembly.

The present application relates to a kind of low-frequency magnetic field generator for rat electromagnetic experiment and its uniform area measuring method, the method includes the following steps: S1, analysis display terminal calculates the magnetic induction intensity distribution of Helmholtz coil under given condition, and according to the change of magnetic induction intensity relative error determines the uniform area of magnetic field distribution, is recorded as reference area, corresponding boundary is reference boundary;S2, using magnetic field probe coil measures the magnetic induction intensity on reference boundary;S3, least square method is applied to obtain the measured boundary of magnetic field distribution uniform area;S4, according to the average absolute percentage error of magnetic induction intensity at measured boundary and reference boundary determines its actual uniform boundary;S5, analysis display terminal displays the actual uniform area of Helmholtz coil magnetic field distribution under given current amplitude and frequency, for rat electromagnetic experiment.Compared with prior art, the present application has the advantages of obtaining accurate magnetic field uniform area, reducing test workload and the like.

The invention discloses a high-frequency transformer winding loss calculation method based on finite element and eddy current loss characteristics, and the method comprises the following steps: 1, building a model of a Helmholtz coil and a single winding through finite element software, and simulating an alternating magnetic field in a high-frequency transformer through the Helmholtz coil; 2, changing the magnetic field frequency, and recording the eddy current loss of a single winding of the high-frequency transformer at different frequencies of a Helmholtz coil; step 3, an eddy-current loss correction factor between different frequencies is calculated by using an eddy-current loss characteristic formula; 4, the eddy-current loss generated in the high-frequency transformer winding is calculated by using the eddy-current loss factor, and comparison verification is carried out by using a traditional formula method; 5, adding the eddy current loss to the direct current loss of the high-frequency transformer winding to obtain the total winding loss of the high-frequency transformer; the method solves the problem that a common eddy current factor method is not high in calculation precision.

The utility model relates to the technical field of brake systems, in particular to a test device for electromagnetic detection of a brake oil can alarm. A testing device for electromagnetic detection of a brake oil can alarm is characterized in that a computer monitor of a computer is connected with a computer host through a computer signal line, the computer host is connected with the signal input end of a signal receiver through a first signal line, and the signal output end of the signal receiver is connected with a coil testing mechanism through a second signal line; the power input end of the signal receiver is connected with the programmable power supply through a first power line, and the power output end of the signal receiver is connected with the coil testing mechanism through a second power line. Compared with the prior art, the Helmholtz coil mechanism is utilized, the brake oil pot alarm is placed in the Helmholtz coil mechanism to be tested, the magnetic field intensity of the oil pot alarm is automatically tested and calculated, and the magnetic field intensity of the brake oil pot alarm is tested.

The invention discloses a dynamic quantization axis control device for multi-axis inertial measurement, which comprises an interference cavity, two ends of the interference cavity are respectively provided with an atom source, and two orthogonal laser groups and three pairs of mutually orthogonal Helmholtz coils are arranged outside the interference cavity. The invention further discloses a dynamic quantization axis control method for multi-axis inertial measurement, according to a preset axial distribution time sequence, the atom source continuously emits cold atomic groups to the interference cavity, the magnetic field generated by the Helmholtz coil and start and stop of the laser group are periodically switched, and therefore quasi-synchronous measurement of the double-axis inertial quantity is achieved. The method can be quickly expanded into full-vector inertial measurement. By introducing rapid adiabatic shortcut magnetic field pulse rotation and utilizing three-axis orthogonal magnetic field waveform control and anti-adiabatic compensation field design, it is ensured that atomic spin adiabatically follows a quantization axis while magnetic field direction switching is completed at a sub-millisecond level, non-adiabatic transition and Zeeman phase shift accumulation are effectively inhibited, and interference contrast and phase stability are ensured.

The invention relates to the technical field of active magnetic compensation, and discloses an active magnetic compensation driving system based on a forward converter, and the system comprises a power module which comprises an AC-DC circuit, a double-end forward circuit and an auxiliary power supply; the constant current source module is connected with the output end of the power supply module, and the constant current source module comprises a coil load interface, a constant current structure and a current signal acquisition circuit, and the constant current structure is formed by four parallel MOSFETs (Metal-Oxide-Semiconductor Field Effect Transistors) and an operational amplifier; one end of the constant current structure is connected with the coil load interface, and the other end of the constant current structure is connected with the current signal acquisition circuit; the digital control module comprises a control unit and a lower computer; the invention discloses a uniaxial Helmholtz coil and a fluxgate sensor. According to the invention, the output power and the precision can be improved, and the requirements of high-precision applications such as active magnetic compensation are met.

The invention relates to the technical field of electrical safety, and provides an electric leakage detection device and method based on a Helmholtz coil and a Hall chip, and the device comprises a Helmholtz coil assembly, a Hall sensing module, a signal processing module, and an execution mechanism. The Helmholtz coil assembly sleeves the outer sides of a phase line and a zero line of a detected circuit and is used for sensing a magnetic field generated by leakage current in the circuit; the Hall sensing module is arranged in the central area of the Helmholtz coil assembly and is used for detecting the magnetic field intensity and converting the magnetic field intensity into an electric signal; and the signal processing module processes and analyzes the electric signal, and drives the actuating mechanism to cut off the circuit when electric leakage is judged. Compared with a traditional zero-sequence mutual inductor and leakage protection chip scheme, the Helmholtz coil and Hall chip combined scheme has the advantages of being high in detection sensitivity, high in response speed, good in linearity, excellent in temperature stability and the like, and can be widely applied to various electrical safety protection fields.

The utility model discloses a light path test device for three-dimensional measurement of a weak magnetic field, which relates to the technical field of weak magnetic field measurement and comprises a working circular truncated cone, a first support and a second support are fixed on the working circular truncated cone, and the end of the first support far away from the working circular truncated cone is rotatably connected with a placing plate. The end, away from the working circular truncated cone, of the second support is rotationally connected with an angle adjusting plate, a magnetic field measuring box is fixed to the angle adjusting plate, an Arduino development board is fixed into the magnetic field measuring box, a polarizer and an analyzer are arranged on the two sides of the Arduino development board respectively, and a photodiode electrically connected with the Arduino development board is arranged on the Arduino development board. An aluminized reflecting mirror which rotates in the magnetic field measuring box is arranged on the outer side of the polarizer or the polarization analyzer, and a Helmholtz coil is further arranged between the first support and the second support; the equipment can more accurately measure the magnetic field intensity in the magneto-optic glass, and avoids the limitation that the Faraday effect can only enable a light beam in the same direction as the magnetic field to deflect.

The invention discloses an optical fiber interferometer precision adjustment vibration reduction platform for plasma density diagnosis, and belongs to the technical field of magnetic confinement nuclear fusion plasma diagnos.The optical fiber interferometer precision adjustment vibration reduction platform comprises symmetrically-arranged vibration reduction bases, supporting columns are arranged above the vibration reduction bases, a cross beam is arranged above the supporting columns, and the cross beam is arranged above the vibration reduction bases. Cantilever supports are symmetrically arranged on the lower surface of the cross beam, cylindrical coil fixers are arranged on the peripheries of the cantilever supports, Helmholtz coils are arranged on the cylindrical coil fixers, L-shaped collimator fixers are arranged on the cantilever supports, and optical fiber interferometer collimators are arranged on the L-shaped collimator fixers; according to the optical fiber interferometer precision adjustment vibration reduction platform for plasma density diagnosis, environment vibration can be effectively restrained, it is ensured that the optical fiber interferometer reaches the theoretical phase resolution, precision height adjustment and firm locking can be achieved, and the accuracy and reliability of plasma density measurement data are guaranteed.

The present application provides a device, system and method for detecting weak electromagnetic signals of a sample, comprising a driving module, N Helmholtz coils, a low-temperature container, two SQUID modules, a first signal processing module and a second signal processing module; N is a natural number greater than 1; the driving module provides driving signals for each Helmholtz coil, each SQUID module includes a SQUID galvanometer and a gradiometer; the input end of each SQUID galvanometer is connected to each gradiometer; the input end of the first signal processing module is connected to the output end of each SQUID galvanometer, and outputs a first processing signal to the second signal processing module; the second signal processing module determines whether the processing signal produces random resonance. The present application can realize synchronous detection, that is, the sample of the substance to be tested dissolved in the solvent and the sample containing pure solvent are tested synchronously at the same time, further avoiding the error caused by the time difference caused by separate testing.

The invention relates to the technical field of lightning position indicators, and discloses an automatic calibration device and method for a very low frequency-low frequency lightning position indicator. The device comprises a shielding cabin, an electric field radiation antenna, a magnetic field radiation antenna, a lightning signal simulation board and a test instrument. The interior of the shielding cabin is divided into two independent areas, the two radiating antennas are arranged in the shielding cabin, and a taking and placing window is arranged on the outer side of the shielding cabin. The electric field radiation antenna is of a parallel metal plate structure, and the magnetic field radiation antenna is of a Helmholtz coil structure; the lightning signal analog board is connected with the two radiation antennas through shielding cables, and the test instrument is respectively communicated with the lightning signal analog board and the lightning locator to be calibrated. An electric field antenna and a magnetic field antenna of a position indicator to be calibrated can be correspondingly placed in the two radiating antennas through the taking and placing windows. The device can realize the automatic calibration of the positioning instrument, guarantee the accuracy and reliability of calibration, improve the calibration efficiency, and adapt to the respective calibration requirements of the double antennas of the positioning instrument.

The invention discloses a rotary Helmholtz coil magnetic field generating device and a control method thereof, and belongs to the technical field of electromagnetic field generation. The generating device comprises a base, a rotating seat, a fixing shaft, a first coil assembly, a second coil assembly, a driving assembly and a controller. The output end of the driving assembly is connected with the bottom of the rotating base and used for driving the rotating base to rotate. The fixed shaft is fixed at the top of the base; the first coil group is fixed at the top of the rotating seat and rotates along with the rotating seat; the second coil group is fixed at the top of the fixed shaft and is positioned between the first coil groups; an angle sensor for detecting a rotation angle is mounted on the rotating seat; the controller is connected with the driving assembly and the angle sensor and controls output of the driving assembly so as to adjust the rotating angle of the rotating base. According to the invention, the number of coil nesting layers is reduced, the space utilization efficiency is improved, and the required magnetic field direction can be obtained through accurate adjustment.

This invention relates to the field of geomagnetic vector measurement technology and proposes an in-situ rapid calibration method for a cubic magnetic gradient tensor measurement array. This invention utilizes a triaxial Helmholtz coil system to generate a constant magnetic field with random orientation and actively compensates for environmental magnetic drift. A hierarchical calibration algorithm is used to sequentially estimate sensor-level inherent errors and array-level alignment errors, and an evaluation framework based on tensor invariants is established to quantitatively analyze the calibration effect. Specifically, this includes: constructing a constant modulus random magnetic field, solving the hierarchical calibration algorithm, and evaluation and verification based on tensor invariants. This invention eliminates the need for mechanical array rotation, achieving in-situ rapid calibration in a static array state. It significantly suppresses pseudo-gradients introduced by channel inconsistencies, improving the stability of magnetic gradient tensor measurement by 3 to 5 orders of magnitude. It is applicable to magnetic anomaly detection and target localization scenarios in fields such as geological exploration, underwater tracking, and space magnetic surveying.

The application discloses an anti-interference magnetoresistance multilayer film calibration system and a calibration method thereof, and the system comprises two three-dimensional Helmholtz coils, a three-axis fluxgate magnetometer, a conversion circuit and a control device; when the control device detects that the feedback voltage output by the three-axis fluxgate magnetometer is zero, the second three-dimensional Helmholtz coil is excited to generate an excitation magnetic field, the output voltage of the magnetoresistance multilayer film to be measured under the excitation magnetic field is collected, and calibration is carried out. By nesting two three-dimensional Helmholtz coils, the geomagnetic field interference is monitored by using the high-sensitivity fluxgate magnetometer, and the first three-dimensional Helmholtz coil provides a negative feedback magnetic field to offset the interference of the geomagnetic field. The second three-dimensional Helmholtz coil provides an excitation magnetic field to test and calibrate the magnetoresistance multilayer film to be measured. The interference of the external geomagnetic field can be offset from any direction, the defect of poor axial shielding effect of the magnetic shielding cylinder is avoided, and the calibration of the high-sensitivity magnetoresistance multilayer film can be realized without the construction of a large magnetic shielding room.

A self-calibrating magnetometer comprising a magnetometer, a set of Helmholtz coils, a current source, and a controller is presented. The magnetometer has three sense coils arranged to detect magnetic fields along three axes. The Helmholtz coils are arranged adjacent to the magnetometer and configured to generate magnetic fields for calibration. The current source energizes the set of Helmholtz coils with a signal that varies over time and the controller determines a calibration for the magnetometer by comparing the magnetic fields detected by the magnetometer to an expected magnetic field.

A magnetic field system and magnetic field control method for a wide-angle helium-3 neutron polarization device are disclosed, relating to the field of helium-3 polarization technology. The system includes four sets of Helmholtz coils; a first set of Helmholtz coils is nested within a second set of Helmholtz coils; the plane of the first set of Helmholtz coils intersects the plane of the second set of Helmholtz coils, with the intersection line passing through the center of the circles containing the first and second sets of Helmholtz coils; the second set of Helmholtz coils is nested within a third set of Helmholtz coils; the third set of Helmholtz coils is nested within a fourth set of Helmholtz coils; the plane of the third set of Helmholtz coils intersects the plane of the fourth set of Helmholtz coils, with the intersection line passing through the center of the circles containing the third and fourth sets of Helmholtz coils; the plane of the third set of Helmholtz coils is perpendicular to the plane of the first set of Helmholtz coils; the plane of the fourth set of Helmholtz coils is perpendicular to the plane of the second set of Helmholtz coils.

The invention discloses a magnetic sensor calibration method, which obviously improves the calibration efficiency, relates to the technical field of magnetic sensor calibration, simplifies the traditional multi-position calibration (generally needing more than six positions) into only needing two specific positions, shortens the calibration time by more than 60%, and is particularly suitable for a batch production environment. The calibration precision is guaranteed, the sensitivity matrix and the zero offset parameter can be accurately solved by accurately controlling the magnetic field of the Helmholtz coil and the angle of the rotating platform and combining a reasonable error model, and the precision requirements of most application scenes are met. The system structure is simplified, only rotation control of two specific positions is needed, a complex three-dimensional rotation mechanism is not needed, and the system cost and the maintenance difficulty are reduced.

The invention relates to a magnetoelectric non-contact speed measurement system and method based on output signal phase step, the system comprises a Helmholtz coil, a signal generator, a magnetoelectric antenna and a phase demodulation module, the magnetoelectric antenna is arranged in the Helmholtz coil and is parallel to the axial direction of the Helmholtz coil; the sensitive direction of the magnetoelectric antenna is arranged along the direction of a circumferential tangential direct current magnetic field generated by a rotor magnetic pole of the permanent magnet motor, the signal generator is electrically connected with the Helmholtz coil and is used for outputting alternating current to the Helmholtz coil, and the Helmholtz coil generates an alternating magnetic field to drive the magnetoelectric antenna to resonate and output a voltage signal; and the phase demodulation module is electrically connected with the magnetoelectric antenna and is used for detecting the phase step of the voltage signal output by the magnetoelectric antenna to generate a pulse signal, and the number of the pulse signal per minute is used as the number of phase step times per minute to obtain the rotating speed. Non-contact rotating speed measurement of the permanent magnet motor is achieved, stability is high, and errors are small.