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CN-122025343-A - Multipolar magnetizing method and system for complex curved permanent magnet

CN122025343ACN 122025343 ACN122025343 ACN 122025343ACN-122025343-A

Abstract

The application relates to the technical field of permanent magnet magnetizing, and discloses a complex curved surface permanent magnet multipolar magnetizing method and a complex curved surface permanent magnet multipolar magnetizing system. The method comprises the steps of preparing a permanent magnet to be magnetized and importing data of a magnetization vector field, conducting self-adaptive meshing on the permanent magnet to be magnetized, determining a magnetizing sequence from strong to weak, planning a magnetizing path, conducting pre-magnetizing on all magnetizing units according to the path sequence, generating a pulse magnetic field meeting parameter requirements to complete magnetizing, conducting magnetic field distribution measurement and deviation calculation, reconstructing an actual magnetization vector field, calculating deviation of the actual magnetization vector and a target magnetization vector, identifying an exceeding unit exceeding an accuracy threshold, establishing a magnetizing response model, obtaining coupling interference of adjacent units, calculating compensation parameters of the exceeding unit, and iterating until the whole field magnetic field distribution meets the accuracy requirement. The application realizes the omnibearing and high-precision multipolar magnetization of the complex curved permanent magnet, and the magnetization direction can be continuously changed in the three-dimensional space, thereby effectively inhibiting the interference of adjacent areas.

Inventors

  • MENG XIAOWEI
  • HE KETAI
  • DONG HAO
  • DU YANGWEI

Assignees

  • 北京科技大学

Dates

Publication Date
20260512
Application Date
20260113

Claims (10)

  1. 1. A complex curved permanent magnet multipole magnetizing method, characterized in that it comprises: Step S1, preparing a permanent magnet to be magnetized and importing magnetization vector field data, and solving the target magnetic induction intensity distribution reversely through a magnetic field inverse problem optimization algorithm in advance to obtain a target magnetization vector of each spatial position of the permanent magnet to be magnetized; Step S2, adaptively dividing the magnetizing units and planning paths, adaptively meshing the permanent magnets to be magnetized by adopting a gradient threshold triggering mechanism, determining the magnetizing sequence from strong to weak according to the descending order of the target magnetic field intensity of each magnetizing unit, and combining with improvement A The algorithm gives consideration to space proximity and obstacle avoidance requirement planning magnetizing paths; s3, performing pre-magnetizing for the first time, and performing pre-magnetizing on each magnetizing unit based on a magnetizing path and a magnetizing sequence to trigger a pulse magnetic field generator to generate a pulse magnetic field meeting parameter requirements so as to complete magnetizing; s4, measuring magnetic field distribution and calculating deviation, reconstructing an actual magnetization vector field, calculating the deviation between an actual magnetization vector and a target magnetization vector based on the actual magnetization vector field, and identifying a magnetization exceeding unit exceeding an accuracy threshold based on the deviation; And S5, performing compensation magnetization, establishing a magnetization response model integrating physical constraint and increment learning, and performing iterative magnetization on the magnetization exceeding unit based on the magnetization response model until the full-field magnetic field distribution meets the precision requirement.
  2. 2. The complex curved surface permanent magnet multipole magnetizing method according to claim 1, wherein in step S1, the solving process of the magnetic field inverse problem optimizing algorithm is: The method comprises the steps of determining the magnetic induction intensity distribution requirement of a target area when a permanent magnet to be magnetized is in a complex three-dimensional curved surface structure and in a demagnetizing state, obtaining the geometric shape and material parameters of the permanent magnet to be magnetized, establishing a magnetic field forward model based on a finite element method or a boundary element method, constructing an optimization problem aiming at minimizing magnetic field errors, applying physical constraints, carrying out iterative solution to obtain a target magnetization vector, and storing the target magnetization vector in a discrete point cloud, regular grid or parameterized function format, wherein the target magnetization vector comprises three-dimensional coordinates, magnetization intensity and magnetization direction information.
  3. 3. The complex curved permanent magnet multipole magnetizing method according to claim 1, characterized in that in step S2, it comprises: Executing a gradient threshold triggering mechanism based on the spatial variation gradient of the target magnetic field vector field, setting a magnetic field variation gradient threshold, automatically adopting fine grids when the magnetic field variation gradient of the local area exceeds the magnetic field variation gradient threshold, and adopting coarse grids when the magnetic field variation gradient threshold is not exceeded, wherein the grid side length of the fine grids is a first length interval, and the grid side length of the coarse grids is a second length interval; improvement A The algorithm balances the moving distance and the energy consumption in path planning by introducing a magnetizing head movement energy consumption weighting factor, and avoids an obstacle region corresponding to the surface protrusion of the permanent magnet.
  4. 4. The complex curved surface permanent magnet multipole magnetizing method according to claim 1, wherein in step S3, the six-degree-of-freedom magnetizing head positioning platform is controlled to move the magnetizing head to a target position and adjust the posture by means of a layered motion planning and coordination control strategy, so that the normal direction of the magnetizing head end surface is aligned to the normal direction of the curved surface of the magnetizing unit, comprising: The layered motion planning and coordination control strategy comprises a task layer, a kinematic layer and an execution layer, wherein the task layer determines the target pose and the air gap distance of the magnetizing head, the kinematic layer solves the motion parameters of each joint through an inverse kinematic algorithm and adopts cubic spline interpolation to plan a smooth track, the execution layer verifies the positioning precision through PID closed-loop control and force sensor feedback, and the permanent magnet to be magnetized is charged to the preset proportion of the target magnetization intensity during pre-magnetizing.
  5. 5. The complex curved surface permanent magnet multipole magnetizing method according to claim 1, wherein in step S3, the parameter calculation process corresponding to the pulsed magnetic field is: Extracting target magnetization intensity, multiplying the target magnetization intensity by a pre-charge coefficient, combining a permanent magnet material magnetization curve fitting equation and a dynamic correction coefficient to obtain required external magnetic field intensity, calculating air gap loss through a magnetic circuit loss model, and calculating charging voltage and discharging time sequence of a pulse power supply by utilizing an ampere loop law and a capacitance discharging formula and combining circuit efficiency correction according to coil parameters of a magnetizing head.
  6. 6. The complex curved surface permanent magnet multipole magnetizing method according to claim 1, wherein in step S4, the magnetic field distribution measuring unit collects full-field magnetic field data using a partition synchronous scanning mode, comprising: The method comprises the steps that a measuring area is divided into a plurality of subareas in a subarea synchronous scanning mode, a mechanical arm clamps a Hall element array to synchronously scan and measure each subarea, a scanning path is in an S shape or a spiral shape, splicing errors of measurement data of adjacent subareas are eliminated through an overlapping area fusion algorithm, and the mechanical arm clamps the Hall element array to be formed by arranging a plurality of triaxial Hall sensors according to preset intervals.
  7. 7. The complex curved permanent magnet multipole magnetizing method of claim 6, wherein reconstructing the actual magnetization vector field using a magnetic field inversion algorithm incorporating regularization method, further comprises: The magnetic field inversion algorithm fused with the regularization method adopts a Gihonov regularization or truncated singular value decomposition method to stably solve a linear equation set, determines regularization parameters through an L-curve method, introduces magnetization upper limit constraint and direction continuity constraint at the same time, and ensures that the reconstructed actual magnetization vector field accords with a physical rule.
  8. 8. The complex curved surface permanent magnet multipole magnetizing method according to claim 1, wherein in step S5, the magnetizing response model is a hybrid model, comprising: the hybrid model comprises a physical model and a data driven model; The physical model establishes local linear approximation based on Stoner-Wohlfarth theory, the data driving model adopts a three-layer feedforward neural network, the off-line stage trains the network through a plurality of groups of magnetizing-measuring experimental data, and the on-line stage updates network parameters in real time through an incremental learning method; The magnetizing response model acquires coupling interference of adjacent units, calculates compensation parameters of the magnetizing exceeding unit through a constraint optimization algorithm, performs compensation magnetizing based on the compensation parameters, performs magnetic field measurement and deviation calculation again, and iterates magnetizing based on a calculation result until the full-field magnetic field distribution meets the precision requirement; the constraint optimization algorithm adopts a quadratic programming algorithm, and the magnetization disturbance quantity of adjacent units is used as a constraint condition to solve the optimal compensation magnetic field intensity and direction.
  9. 9. A complex curved permanent magnet multipole magnetizing system for implementing a complex curved permanent magnet multipole magnetizing method according to any of claims 1 to 8, characterized in that it comprises: The device comprises a six-degree-of-freedom magnetizing head positioning platform, a pulse magnetic field generator, a permanent magnet positioning platform, a magnetic field distribution measuring unit and a control and data processing system; The six-degree-of-freedom magnetizing head positioning platform adopts a three-joint serial structure, each joint comprises a rotation degree of freedom and a translation degree of freedom, and a high-precision driving device and a position feedback device are arranged; The pulse magnetic field generator consists of a charging head and a pulse power supply, the charging head is arranged at the tail end of the six-degree-of-freedom positioning platform, an electromagnetic coil and a magnetic circuit iron core are integrated in the pulse power supply, a large-capacitance energy storage and controllable discharge circuit is adopted by the pulse power supply, a short-time high-intensity pulse magnetic field is generated, the peak intensity of the pulse magnetic field reaches the magnetic field intensity required by the saturation magnetization of a permanent magnet material, the pulse power supply is connected to the charging head through a cable, and a control system calculates required capacitance charging voltage and discharge time sequence according to magnetizing parameters to trigger the pulse power supply to release energy to the coil of the charging head; The permanent magnet positioning platform comprises a special fixture customized according to the shape of the permanent magnet and a high-rigidity positioning base, and the fixture adopts a mechanical locking and vacuum adsorption composite fixing mode; The magnetic field distribution measuring unit comprises a Hall element array, a multi-degree-of-freedom mechanical arm and a magnetic field data processor, wherein the mechanical arm is provided with a path self-adaptive adjusting module, and the scanning track is corrected in real time according to the curved surface shape of the permanent magnet; And the control and data processing system integrates modularized functions corresponding to magnetization vector field data processing, motion control, parameter calculation and deviation analysis.
  10. 10. The complex curved surface permanent magnet multipole magnetizing system of claim 9, wherein each subsystem cooperates with the data processing system through the control to achieve high precision multipole magnetizing of the complex curved surface permanent magnet to be charged.

Description

Multipolar magnetizing method and system for complex curved permanent magnet Technical Field The application relates to the technical field of permanent magnet magnetizing, in particular to a complex curved surface permanent magnet multipolar magnetizing method and a complex curved surface permanent magnet multipolar magnetizing system. Background The permanent magnet magnetizing method is a key process link of permanent magnet material application, and the traditional permanent magnet magnetizing method mainly comprises the technologies of whole immersion magnetizing, specific fixture magnetizing, magnetic field auxiliary additive manufacturing, local magnetizing and the like. The method comprises the steps of carrying out integral immersion magnetization, namely putting the whole permanent magnet into a uniform strong magnetic field to carry out integral magnetization, wherein the integral immersion magnetization can only generate uniform unidirectional magnetization, and cannot meet multipolar magnetization requirements, the specific fixture magnetization is required to design a special magnetization fixture aiming at specific shapes such as a circular ring, a cylinder and the like, only a preset regular magnetization mode such as radial 2 poles, radial 4 poles, radial 8 poles and the like can be realized, adaptability is extremely poor, the magnetic field auxiliary additive manufacturing is to synchronously apply an external magnetic field to orient magnetic powder in the printing process, but the magnetic field direction is limited, the magnetization of a printed part can influence a subsequent layer, accurate control is difficult to realize, the local magnetization technology is to carry out local partition magnetization on the planar permanent magnet through a small-sized magnetization head, the special magnetization fixture is only suitable for a plane or a shallow curved surface, and the magnetization head is usually in a fixed direction, and has large limitation. In multipole magnetizing applications of complex curved permanent magnets, there are a number of significant problems with the prior art. Firstly, the prior magnetizing technology cannot adapt to complex three-dimensional curved surface geometry, the prior magnetizing technology is basically limited to simple geometry such as planes, cylinders, circular rings and the like, for complex curved surface permanent magnets such as saddle surfaces, twisted ring surfaces, free curved surfaces and the like, the magnetizing head is difficult to approach each part in a correct pose and is easy to cause magnetizing blind areas or uneven magnetization, secondly, the magnetizing direction which is continuously changed in space cannot be realized, the traditional method only can generate single-direction or regular multipolar magnetization, the application of the twisting magnetic field and the like of the permanent magnet star simulator which needs to continuously change in the three-dimensional space is difficult to meet the requirement, thirdly, the adjacent areas in multipolar magnetizing are greatly interfered with each other, the adjacent areas in partial partition magnetizing are mutually influenced to cause the accumulation of magnetizing deviation, the prior art lacks a disturbance suppression strategy and a compensation method of a system, the magnetizing precision is difficult to guarantee, fourthly, the closed loop feedback and precision control mechanism is lacking, the traditional magnetizing is in an open loop process, the actual measurement feedback and the iterative optimization are lacked after magnetizing, the magnetizing parameters depend on experience setting, and the high precision requirement is difficult to reach for complex magnetizing distribution. With the development of advanced magnetic field regulation technology, the permanent magnet star simulator, magnetic suspension, magnetic resonance imaging, particle accelerator and other leading edge scientific and engineering fields provide new requirements for the performance of the permanent magnet. These fields require permanent magnets of complex three-dimensional curved surface shape with magnetization direction continuously varying along the curved surface to achieve a specific magnetic field distribution. The additive manufacturing technology enables the preparation of the complex curved permanent magnet to be possible, but the magnetic powder is in a random orientation demagnetizing state in the printing process, the magnetic property is required to be endowed by subsequent magnetization, and the traditional magnetization method cannot be matched with the geometrical freedom degree brought by the additive manufacturing. Therefore, a magnetizing method and a magnetizing system which can adapt to a complex curved permanent magnet, realize spatially continuous change of magnetization direction, reduce magnetization interference of adjacent areas and have high-precision control