Magnetic field adjusting method of magnetic suspension planar motor

Abstract

The invention is suitable for the technical field of planar motors, and provides a magnetic field adjusting method of a magnetic suspension planar motor. The magnetic suspension planar motor comprises a rotor assembly and a stator assembly. The rotor assembly comprises a rotor top plate, a controller cabin, an adjustable magnetic array layer and a rotor bottom plate which are connected from top to bottom. The adjustable magnetic array layer comprises a permanent magnet array and a magnetic field reconstruction unit, and the permanent magnet array is formed by arranging a plurality of permanent magnet sub-array units; the magnetic field reconstruction units are arranged in magnetic pole gaps of the permanent magnet array, and each magnetic field reconstruction unit comprises a miniature soft magnetic core and a miniature coil wound on the miniature soft magnetic core; a rotor controller used for receiving an instruction and controlling the current of the micro coil is arranged in the controller cabin; the method is adjusted by controlling the magnetic field reconstruction unit. According to the invention, the problem of poor magnetic flux leakage magnetic field utilization rate caused by physical gaps between rotor permanent magnets in a planar motor is solved.

Description

Technical Field

[0001] This invention relates to the field of planar motor technology, and in particular to a method for adjusting the magnetic field of a magnetically levitated planar motor. Background Technology

[0002] Magnetic levitation planar motors, as a type of drive device capable of achieving contactless, high-precision, and high-speed movement of the mover in two-dimensional or three-dimensional space, have significant application prospects in fields such as semiconductor lithography, precision manufacturing, and micro-nano manipulation. Their working principle typically relies on the electromagnetic interaction between an array of permanent magnets on the mover and an array of coils on the stator to generate the required levitation and driving forces. In a typical magnetic levitation planar motor, the mover assembly is equipped with a magnetic array composed of permanent magnets (such as a Heilbeck array). Levitation and propulsion are achieved through the interaction between the magnetic field generated by the permanent magnets and the electromagnetic coils on the stator side.

[0003] However, existing mover structures generally suffer from low magnetic field utilization, severely limiting the thrust density and energy efficiency ratio of motors. Specifically, the permanent magnet arrays on existing movers have certain physical gaps, which lead to significant magnetic flux leakage. In the gap regions between permanent magnets, magnetic field lines cannot be effectively constrained and guided as they are inside the magnets; instead, they diverge into the surrounding space, forming closed loops, rather than being concentrated entirely in the working air gap. This magnetic flux leakage results in a more uneven magnetic field distribution, which should be highly concentrated on the mover's working surface, with the magnetic field density at the pole gaps significantly lower than the ideal value. Summary of the Invention

[0004] This invention provides a mover assembly, a magnetically levitated planar motor, and a magnetic field adjustment method, aiming to solve the problems of magnetic flux leakage and low magnetic field utilization caused by the physical gap between the mover permanent magnets in a planar motor. The technical solution is as follows: A method for adjusting the magnetic field of a magnetically levitated planar motor is disclosed. The magnetically levitated planar motor includes a mover assembly and a stator assembly. The mover assembly includes a mover top plate, a controller compartment, an adjustable magnetic array layer, and a mover bottom plate connected from top to bottom. The adjustable magnetic array layer includes a permanent magnet array and a magnetic field reconstruction unit. The permanent magnet array is composed of multiple permanent magnet sub-array units. The magnetic field reconstruction unit is disposed in the magnetic pole gap of the permanent magnet array. Each magnetic field reconstruction unit includes a miniature soft magnetic core and a miniature coil wound on the miniature soft magnetic core. The controller compartment is equipped with a mover controller for receiving commands and controlling the current of the miniature coil. The magnetic pole gap is the gap between adjacent permanent magnets in the permanent magnet sub-array unit or the inter-unit gap between adjacent permanent magnet sub-array units. The method adjusts the magnetic field reconstruction unit by controlling it, and includes the following steps: S1: Based on the magnetic field distribution data of the mover, obtain the adjustment parameters of the magnetic field reconstruction unit that needs to be adjusted. The magnetic field distribution data includes the actual magnetic field distribution data and the target magnetic field distribution data. The adjustment parameters of the magnetic field reconstruction unit include the number of the magnetic field reconstruction unit, the magnetic field strength, and the magnetic field direction. S2: Based on the adjustment parameters of the magnetic field reconstruction unit, obtain the current parameters of the corresponding magnetic field reconstruction unit through the magnetic field strength-current mapping table; S3: Based on the current parameters in step S2, drive the magnetic field reconstruction unit to generate an additional magnetic field.

[0005] Based on the above technical solution, the magnetic pole gap is the gap between adjacent permanent magnets in the permanent magnet subarray unit.

[0006] Based on the above scheme, the method for obtaining the current parameters of the magnetic field reconstruction unit in step S2 includes the following steps: S21: Call the magnetic field strength-current mapping table of the magnetic field reconstruction unit; S22: If the magnetic field strength of the magnetic field reconstruction unit is a non-discrete value, the corresponding current is calculated by linear interpolation based on two adjacent discrete values ​​in the current mapping table of the magnetic field reconstruction unit; if the magnetic field strength of the magnetic field reconstruction unit is a discrete value, the corresponding current is read directly.

[0007] Furthermore, the method includes the following steps: A1: Real-time magnetic field strength is obtained through the Hall sensor array of the stator assembly. after ; A2: Based on the real-time magnetic field strength B after With the initial magnetic field strength B before Calculate the magnetic field compensation amount ΔB'=B before -B after ; A3: Determine whether compensation is needed based on the magnetic field compensation amount ΔB' and the compensation threshold Bq; A4: If the magnetic field strength needs to be compensated, based on the adjustment parameters of the magnetic field reconstruction unit, the current parameters of the corresponding magnetic field reconstruction unit are obtained through the magnetic field strength-current mapping table. A5: Based on the current parameters obtained in step A4, drive the magnetic field reconstruction unit to generate an additional magnetic field.

[0008] Based on the above scheme, the method for obtaining real-time magnetic field strength using a Hall sensor array is as follows: A11: Obtain the real-time voltage value Vh output by the Hall sensor array; A12: The real-time voltage value is converted into real-time magnetic field strength B using a calibration coefficient K. after =K×Vh.

[0009] Furthermore, the mover assembly further includes a reinforcement layer disposed between the adjustable magnetic array layer and the mover base plate; the reinforcement layer includes an array of reinforcement coils, the projection position of the reinforcement coils on the plane corresponding to the position of the permanent magnet array, and the method further includes: A6: If the current in the miniature coil of the magnetic field reconstruction unit is Imax, and at this time B after +ΔB' before Initiate enhancement layer compensation; A7: A compensation current is passed through the reinforcement coil of the reinforcement layer, and the magnetic field generated by the compensation current is in the same direction as the magnetization direction of the corresponding permanent magnet.

[0010] Based on the above scheme, the method for calculating the compensation current is as follows: A71: Calculate the real-time magnetic field strength after compensation by the magnetic field reconstruction unit. after +ΔB' and the initial magnetic field strength B before The average magnetic field deviation ΔBavg; A72: The compensation current of the reinforcement layer is obtained as Ie = ΔBavg / Ke, where Ke is the current-to-magnetic field conversion coefficient.

[0011] Beneficial effects Compared with the prior art, the beneficial effects of the present invention are: 1. This invention integrates a magnetic field reconstruction unit at the magnetic pole gap of a permanent magnet array to generate an additional magnetic field in the same direction as the bias magnetic field, effectively compensating for magnetic flux leakage caused by physical gaps, thereby significantly improving the effective utilization rate of the magnetic field and the thrust output capability per unit volume / mass.

[0012] 2. This invention compensates for the magnetic attenuation of permanent magnets by using a magnetic field reconstruction unit or reinforcement layer, overcoming the performance degradation caused by factors such as permanent magnet aging or temperature drift in traditional planar motors, ensuring the long-term stability of the planar motor system, and significantly extending the service life of the mover assembly. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only one embodiment of the present invention. For those skilled in the art, other embodiments can be derived from the provided drawings without creative effort.

[0014] Figure 1 : A schematic diagram of the structure of the magnetic levitation planar motor described in this invention; Figure 2 ​: Figure 1 An explosion diagram; Figure 3 : A schematic diagram of the existing Hellbeck array; Figure 4 : A schematic diagram showing the location of the magnetic field reconstruction unit in the gap between adjacent permanent magnets in the Heilbeck array described in this invention; Figure 5 : A schematic diagram of the magnetization of the magnetic field reconstruction unit of the gap between adjacent permanent magnets in the Heilbeck array of the present invention; Figure 6 : A schematic diagram of the structure after splicing existing permanent magnet subarray units; Figure 7 : A schematic diagram of the magnetic field reconstruction unit position of the inter-unit gap between the permanent magnet sub-array units described in this invention; Figure 8 : A schematic diagram of the magnetic field reconstruction unit for the gap between permanent magnet subarray units described in this invention. Detailed Implementation

[0015] The present invention will be further described below with reference to the accompanying drawings and examples: Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0016] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0017] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0018] Example 1 This embodiment provides a mover assembly, which includes a mover top plate 1, a controller compartment 2, an adjustable magnetic array layer 3, and a mover bottom plate 4 connected from top to bottom.

[0019] The adjustable magnetic array layer 3 includes a permanent magnet array and a magnetic field reconstruction unit 32, which is composed of multiple permanent magnet sub-array units. The magnetic field reconstruction unit 32 is disposed in the magnetic pole gap of the permanent magnet array, and each magnetic field reconstruction unit 32 includes a micro soft magnetic core and a micro coil wound on the micro soft magnetic core.

[0020] The soft magnetic core can be a slender column, and the specifications of the magnetic field reconstruction unit are basically matched with the pole gap of the permanent magnet array. The miniature coil is continuously wound along the axis of the soft magnetic core to form a compact coil column.

[0021] To reduce heat generation, the miniature soft magnetic core uses amorphous or nanocrystalline materials with low loss and high saturation magnetic induction intensity to reduce core loss. The coil uses high-temperature resistant enameled wire.

[0022] The mover assembly also includes a reinforcement layer disposed between the adjustable magnetic array layer 3 and the mover base plate 4; the reinforcement layer includes a reinforcement coil, the projection position of the reinforcement coil on the plane corresponding to the position of the permanent magnet array.

[0023] The controller compartment 2 is equipped with a mover controller for receiving commands and controlling the current of the micro coil. After the micro coil leads converge, they are connected to the drive circuit in the controller compartment 2 through a flexible circuit. When current is passed through the micro coil, an additional magnetic field is formed at the magnetic pole gap. The additional magnetic field is vector-superimposed with the bias magnetic field generated by the permanent magnet array at the magnetic pole gap, thereby enhancing the magnetic field strength in the magnetic pole gap region.

[0024] Figure 6 This is a schematic diagram of an existing permanent magnet unit in the form of a Hellbeck array. Multiple such permanent magnet array units make up the entire mover permanent magnet array. The magnetization direction of each permanent magnet is shown by the arrow, forming a basic magnetic field distribution.

[0025] The two-dimensional Hellbeck array 31 includes a first magnet located at the center and four second magnets respectively arranged around the first magnet. The magnetic field direction of the first magnet is perpendicular to the fixed surface it is positioned outwards, while the magnetic field direction of the four second magnets arranged around the first magnet is horizontal and points towards the first magnet. At the pole gaps, the Hellbeck array already possesses a bias magnetic field with specific direction and intensity, formed by the combined action of adjacent permanent magnets.

[0026] The magnetic field reconstruction unit can be set in the magnetic pole gap between the four magnets arranged around the first magnet and the first magnet.

[0027] like Figure 4As shown, there are magnetic pole gaps between adjacent permanent magnets, and a magnetic field reconstruction unit 32 is embedded in each gap. The magnetic field reconstruction unit 32 consists of a miniature soft magnetic core and a miniature coil wound around it.

[0028] When the mover controller needs to adjust the local magnetic field according to instructions, it supplies a precisely controlled current to a miniature coil at a specific location. The current flowing through the miniature coil generates a controllable additional magnetic field, the direction and strength of which depend on the direction and magnitude of the coil current. This additional magnetic field is vector-superimposed on the existing bias magnetic field at the gap, which is formed by the surrounding permanent magnets.

[0029] like Figure 5 As shown, by controlling the direction of the current, the additional magnetic field is made to be in the same direction as the bias magnetic field, thereby realizing the magnetic field strength of the local area.

[0030] In the static state (with no current flowing through the miniature coil), the soft magnetic core of the magnetic field reconstruction unit 32 has extremely high permeability, forming a low magnetic reluctance path that guides some of the magnetic field lines that would otherwise leak through the soft magnetic core. This changes the static magnetic field distribution of the entire array, but its main static magnetic field is still dominated by the permanent magnet array.

[0031] During adjustment (current passes through the micro coil): When current is passed through the micro coil of the magnetic field reconstruction unit 32, an additional magnetic field is formed at the magnetic pole gap. The additional magnetic field can be in the same direction as the bias magnetic field of the permanent magnet array, thereby enhancing the effect of the local magnetic field.

[0032] By using the existing magnetic pole gap to embed the micro magnetic field reconstruction unit 32, there is no need to increase the overall thickness or volume of the mover, thus maximizing the compactness of the mover, achieving high acceleration and high dynamic response, while avoiding adverse effects on the motor air gap.

[0033] The permanent magnet array and the magnetic field reconstruction unit 32 are encapsulated into a single module using high-strength, thermally conductive epoxy resin. The high-strength epoxy resin firmly bonds and fixes multiple permanent magnets and the embedded micro-magnetic field reconstruction unit 32 together, forming a rigid whole. During high-speed, high-acceleration movement of the mover, the permanent magnets will not loosen or the reconstruction unit 32 will not detach due to severe vibration or impact, ensuring the structural integrity of the mover assembly and its long-term operational reliability. The controller compartment 2 also integrates a wireless communication module, a wireless power supply module, and a micro drive circuit; the wireless communication module and the micro drive circuit are both electrically connected to the mover controller; the micro drive circuit is also electrically connected to the micro coil of the magnetic field reconstruction unit 32.

[0034] The wireless power supply module provides power to the mover controller, micro drive circuit and micro coil, and the wireless communication module receives external commands and transmits status information back, enabling the mover to move freely, at high speed and without restriction.

[0035] Example 2 Based on Embodiment 1 above, the difference between the mover assembly provided in this embodiment and Embodiment 1 is that the permanent magnet array is composed of multiple independent permanent magnet sub-array units spliced ​​together, and the magnetic pole gap of the magnetic field reconstruction unit is the inter-unit gap between each permanent magnet sub-array unit. In other embodiments, the magnetic field reconstruction unit is simultaneously provided in the inter-unit gap between the permanent magnet sub-array units and the gap between adjacent permanent magnets within the unit.

[0036] Reference Figure 6 The permanent magnet array of the mover consists of multiple independent permanent magnet subarray units. Each subarray unit is a small two-dimensional Helbeck array (or other optimized magnetic circuit combination of permanent magnets) with strong local magnetic field focusing capability. These permanent magnet subarray units are spliced ​​together on the mover base plate according to a predetermined two-dimensional layout to form a complete magnetic array layer.

[0037] During assembly, relatively wide inter-unit gaps are formed between adjacent permanent magnet subarray units. These gaps are no longer tiny slits between individual permanent magnets, but rather regions of a certain width between permanent magnet subarray units. Magnetic field reconstruction units 32 are disposed within these inter-unit gaps. Similar to Embodiment 1, multiple reconstruction units 32 are distributed along the gaps.

[0038] When the mover controller needs to make adjustments, the micro-drive circuit, according to the controller's instructions, supplies a specific current to the micro-coils within the inter-cell gaps. This current generates an additional magnetic field in the micro-soft magnetic core. This additional magnetic field is vector-superimposed on the edge magnetic fields generated at the boundaries of two adjacent permanent magnet subarray units. By controlling the current in each reconfiguration unit within the gap, the magnetic field coupling strength between adjacent subarray units can be enhanced. For example, the enhanced magnetic field can connect two subarrays, making the overall magnetic field more continuous.

[0039] Furthermore, the magnetization direction of the magnetic field reconstruction unit 32 is diagonal along the magnetic block. Based on the magnetization direction of the surrounding magnetic blocks, an oblique magnetization direction is set to achieve unidirectional superposition of magnetic fields. This better aligns the magnetic circuit direction with the bias magnetic field direction at the gap, enhancing the coupling efficiency between the additional magnetic field and the bias magnetic field.

[0040] Specifically, such as Figure 7 and Figure 8As shown in the illustration, this embodiment demonstrates a permanent magnet array composed of two permanent magnet subarray units (two-dimensional Helbeck array), which will be used as an example for explanation. A first central magnet with its magnetization direction facing outwards from the paper (represented by a dot) and a second central magnet with its magnetization direction facing inwards from the paper (represented by a cross) are provided. Magnets are positioned horizontally to the first central magnet and vertically to the first central magnet, while magnets with magnetic fields opposite to the second central magnet are positioned horizontally and vertically to the second central magnet.

[0041] Multiple reconstruction units 32 are added between the two permanent magnet subarray units. In the corner gaps on the side of the first central magnet, the reconstruction units 32 face the first central magnet; in the corner gaps on the side of the second central magnet, the magnetic field of the reconstruction units 32 is opposite to that of the second central magnet. Furthermore, the magnetization direction of the corner magnetic field reconstruction units 32 is along the diagonal direction of the magnetic block. To better align the magnetic circuit direction with the bias magnetic field direction at the gap, the coupling efficiency between the additional magnetic field and the bias magnetic field can be enhanced. In this case, the reconstruction unit 32 located between the first and second central magnets has its magnetic field direction facing downwards.

[0042] Example 3 like Figure 1 and Figure 2 As shown, this embodiment provides a magnetic levitation planar motor, which is configured with a mover assembly 10 of either embodiment 1 or 2.

[0043] The magnetic levitation planar motor also includes a stator assembly 11, which includes a stator top plate 5, a coil array layer 6 and a stator base 8 arranged from top to bottom. When current is passed through the coil array layer 6, it generates electromagnetic force, which interacts with the magnetic field generated by the adjustable magnetic array layer 3 of the mover assembly 10, driving the mover assembly 10 to levitate and move above the stator assembly.

[0044] The coil array layer 6 serves as the direct source of electromagnetic force. When current is applied, it interacts with the magnetic field of the adjustable magnetic array layer 3 to generate a precise and controllable Lorentz force or magnetic resistance. This enables the mover to levitate freely in the X, Y, and Z directions and move at high speed and with high precision in a two-dimensional plane, meeting the core requirements of a precision positioning system.

[0045] The stator top plate 5 is made of a high-permeability material (such as silicon steel sheet), which can effectively guide and concentrate the magnetic flux generated by the coil array, reduce leakage flux, and form a more efficient closed magnetic circuit.

[0046] The stator assembly 11 also includes a sensor layer 7 for detecting the position information or magnetic field data of the mover assembly 10. The sensor layer 7 is disposed between the coil array layer 6 and the stator base 8. The sensor on the sensor layer 7 can be a Hall sensor or an eddy current sensor.

[0047] Example 4 This embodiment provides a magnetic field adjustment method for the magnetic levitation planar motor applied in Embodiment 3, the method comprising the following steps: S1: Based on the magnetic field distribution data of the mover, obtain the adjustment parameters of the magnetic field reconstruction unit that needs to be adjusted. The magnetic field distribution data includes the actual magnetic field distribution data and the target magnetic field distribution data. The adjustment parameters of the magnetic field reconstruction unit include the number of the magnetic field reconstruction unit, the magnetic field strength, and the magnetic field direction. In this embodiment, step S1, obtaining the adjustment parameters of the magnetic field reconstruction unit, specifically includes: S11: Based on the actual magnetic field distribution data and the target magnetic field distribution data, determine whether the magnetic field at the magnetic pole gap needs adjustment. The magnetic field distribution data includes the magnetic field strength and magnetic field direction. (1) Obtain the magnetic field strength Ba, magnetic field direction θa, target magnetic field strength Bb, and magnetic field direction θb at the magnetic pole gap; (2) If Bb-Ba>0, the magnetic field at the pole gap needs to be strengthened, and the direction of the strengthened magnetic field is the same as that of θa; if Bb-Ba<0, the magnetic field at the pole gap needs to be weakened, and the direction of the strengthened magnetic field is opposite to that of θa.

[0048] S12: Based on Ba, Bb and the type of magnetic pole gap, obtain the adjustment parameters of the magnetic field reconstruction unit corresponding to the magnetic pole gap, specifically including the number, magnetic field strength ΔB and magnetic field direction θ.

[0049] In this embodiment, the magnetic field distribution data of the mover includes actual magnetic field distribution data and target magnetic field distribution data. The actual magnetic field distribution data is obtained by acquiring pre-measured and stored mover magnetic field strength data or by acquiring real-time measured mover magnetic field strength data. The target magnetic field distribution data is magnetic field distribution data designed experimentally to meet the predetermined electromagnetic force requirements of the mover.

[0050] S2: Based on the adjustment parameters of the magnetic field reconstruction unit, the current parameters of the corresponding magnetic field reconstruction unit are obtained through the magnetic field strength-current mapping table. The current parameters include the magnitude and direction of the current. In this embodiment, step S2, obtaining the current parameters of the magnetic field reconstruction unit, specifically includes: S21: Call the pre-stored magnetic field strength-current mapping table of the magnetic field reconstruction unit, wherein the magnetic field strength-current mapping table is the current parameter corresponding to the magnetic field strength of each magnetic field reconstruction unit. S22: If the magnetic field strength is a non-discrete value, the corresponding current is calculated by linear interpolation based on two adjacent discrete values ​​in the magnetic field strength-current mapping table; if the magnetic field strength is a discrete value, the corresponding current parameters are read directly to obtain the current magnitude and direction.

[0051] S3: Based on the current magnitude and direction obtained in step S2, drive the magnetic field reconstruction unit to generate an additional magnetic field; S3 in this embodiment specifically includes the following steps: S31: Converts the current magnitude and direction into a PWM control signal, sends the PWM control signal to the micro drive circuit, and the micro drive circuit outputs current; S32: Input the output current of the micro drive circuit into the micro coil of the corresponding magnetic field reconstruction unit.

[0052] The above steps in this embodiment enable the magnetic field reconstruction unit to generate an additional magnetic field in the magnetic pole gap by precisely controlling the current of the micro coil. The additional magnetic field is vector-superimposed with the bias magnetic field or the actual magnetic field of the permanent magnet array to achieve the adjustment of the local magnetic field.

[0053] This embodiment effectively compensates for magnetic flux leakage caused by physical gaps by controlling the additional magnetic fields of different magnetic field reconstruction units and selectively changing the additional magnetic fields of one or more magnetic field reconstruction units according to actual needs.

[0054] Example 5 This embodiment provides a magnetic field adjustment method for a magnetic levitation planar motor, aiming to solve the problem of magnetic field attenuation caused by the aging of permanent magnets in the rotor of existing magnetic levitation planar motors. The stator assembly 11 in this embodiment includes a sensor layer 7, which is disposed between the coil array layer 6 and the stator base 8. The sensor layer 7 is a Hall sensor array. Because the aging of permanent magnets has a significant impact on the magnetic pole gap, this embodiment compensates for this by adjusting the magnetic field strength of the magnetic pole gap, specifically including the following steps: A1: Real-time magnetic field strength is obtained through the Hall sensor array of the stator assembly. after ; In this embodiment, step A1 specifically includes: A11: Obtain the real-time voltage value Vh output by the Hall sensor array; A12: The real-time voltage value is converted into real-time magnetic field strength B using a calibration coefficient K. after =K×Vh, where K is the conversion coefficient of the Hall sensor in converting the voltage signal into magnetic field strength, and the unit is mT / V.

[0055] A2: Based on the real-time magnetic field strength B after With the initial magnetic field strength Bbefore Calculate the magnetic field compensation amount ΔB' = B before - B after ; In this embodiment, the method for obtaining the initial magnetic field strength in step A2 specifically includes: A21: Obtain the initial voltage value Vi output by the Hall sensor when the mover leaves the factory or when the permanent magnet is in an unaged state; A22: Calculate the initial magnetic field strength B before = K × Vi; A23: Store the initial magnetic field strength in the Flash memory.

[0056] A3: Determine whether compensation is required based on the magnetic field compensation amount ΔB' and the compensation threshold Bq: If ΔB' > Bq, the magnetic field strength needs to be compensated; if ΔB' < Bq, the magnetic field strength does not need to be compensated.

[0057] A4: If the magnetic field strength needs to be compensated, based on the adjustment parameters of the magnetic field reconstruction unit, obtain the corresponding current parameters of the magnetic field reconstruction unit through the magnetic field strength - current mapping table, and the current parameters include the magnitude and direction of the current; In this embodiment, step A4 further includes locating the magnetic field reconstruction unit that needs to compensate the magnetic field strength, specifically including: A41: Obtain the real - time position of the mover (Xm, Ym) and the position of the magnetic field to be reinforced (Xs, Ys); In this embodiment, the real - time position of the mover is obtained by existing methods such as the grating scale or camera on the stator side recorded in the prior art, and the coordinates of this real - time position of the mover are the real - time position coordinates of the center point of the mover in the stator coordinate system.

[0058] In this embodiment, the position of the magnetic field to be reinforced is the position where the Hall sensor detects that the magnetic field strength needs to be compensated, and this position corresponds to the position of the Hall sensor in the stator coordinate system.

[0059] A42: Calculate the offset of the magnetic field reconstruction unit that needs to be compensated to the center point of the mover (i.e., the real - time position of the mover); In this embodiment, the position of the magnetic field to be reinforced (Xs, Ys) corresponds to the position of the magnetic field reconstruction unit on the mover. Due to the projection relationship, except for the different z - coordinates, their x and y - direction coordinates are the same. Therefore, when the magnetic field compensation site on the stator is located by the Hall sensor, the position of the magnetic field reconstruction unit to be adjusted in the stator coordinate system can be clearly corresponding as (Xs, Ys); Based on the real-time position of the mover (Xm, Ym), the offset (ΔX, ΔY) of the magnetic field reconstruction unit to be adjusted from the center point of the mover is calculated, where ΔX = Xs - Xm and ΔY = Ys - Ym. This is useful for subsequent calculations to determine the positioning of the magnetic field reconstruction unit to be adjusted on the mover.

[0060] A43: Locating the Magnetic Field Reconstruction Unit to be Adjusted: The position of the magnetic field reconstruction unit within the mover is fixed. Therefore, using the center point of the mover as the origin, the position (Xv, Yv) of each magnetic field reconstruction unit in the mover coordinate system is obtained. The position (Xv, Yv) of each magnetic field reconstruction unit in the mover coordinate system is matched with the offset (ΔX, ΔY) of the magnetic field reconstruction unit from the center point of the mover to locate the magnetic field reconstruction unit to be adjusted. Specifically, locating the magnetic field reconstruction unit to be adjusted can be either its position or its number.

[0061] A5: Based on the magnitude and direction of the current obtained in step A4, drive the magnetic field reconstruction unit at the corresponding position to generate an additional magnetic field.

[0062] In this embodiment, the A5 driving magnetic field reconstruction unit generates an additional magnetic field in the same way as the driving magnetic field reconstruction unit generates an additional magnetic field in Embodiment 4, and will not be described again here.

[0063] This embodiment directly detects the air gap magnetic field using a Hall sensor. By comparing the air gap magnetic field with that of an unaged air gap, and matching the location requiring compensation with the magnetic field reconstruction unit within the mover pole gap, the magnetic field is compensated to a certain extent by the additional magnetic field of the magnetic field reconstruction unit, ensuring real-time magnetic field compensation during operation. Simultaneously, this embodiment improves the response speed and control accuracy during the real-time movement of the mover through the aforementioned adjustment method.

[0064] Example 6 This embodiment provides a magnetic field adjustment method for a magnetically levitated planar motor. The method is the same as in Embodiment 5, except that the magnetic field is compensated by the reinforcement layer in the mover assembly of Embodiment 1. This aims to solve the problem that the magnetic field ages to the point where it is difficult to achieve effective compensation through the magnetic field reconstruction unit 32. The method includes: A6: If the current in the miniature coil of the magnetic field reconstruction unit is Imax, and at this time B after +ΔB' before Initiate enhancement layer compensation; A7: A compensation current is passed through the reinforcement coil of the reinforcement layer, and the magnetic field generated by the compensation current is in the same direction as the magnetization direction of the corresponding permanent magnet. In step A7 of this embodiment, the method for calculating the compensation current is as follows: A71: Calculate the real-time magnetic field strength after compensation by the magnetic field reconstruction unit.​after +ΔB' and the initial magnetic field strength B before The average magnetic field deviation ΔBavg; A72: The compensation current of the reinforcement layer is obtained as Ie = ΔBavg / Ke, where Ke is the current-to-magnetic field conversion coefficient, which is determined by the number of coil turns, size, etc.

[0065] This embodiment is used to solve the problem of permanent magnet aging that cannot be compensated by the additional magnetic field generated by the magnetic field reconstruction unit. By controlling the reinforcement coil of the reinforcement layer to generate a magnetic field, the magnetic field attenuation generated by the permanent magnet is effectively compensated.

[0066] It should be noted that the actuator controller, wireless communication module, wireless power supply module, micro drive circuit, and sensor layer in this embodiment are all general standard parts or components known to those skilled in the art. Their structure and principles can be learned by those skilled in the art through technical manuals or conventional experimental methods.

[0067] The present invention has been described above by way of example, but the present invention is not limited to the specific embodiments described above. Any modifications or variations made based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A method for adjusting the magnetic field of a magnetically levitated planar motor, the magnetically levitated planar motor comprising a mover assembly (10) and a stator assembly (11), characterized in that, The mover assembly (10) includes a mover top plate (1), a controller compartment (2), an adjustable magnetic array layer (3), and a mover bottom plate (4) connected from top to bottom; the adjustable magnetic array layer (3) includes a permanent magnet array and a magnetic field reconstruction unit (32), the permanent magnet array is composed of multiple permanent magnet sub-array units; the magnetic field reconstruction unit (32) is disposed in the magnetic pole gap of the permanent magnet array, each magnetic field reconstruction unit (32) includes a miniature soft magnetic core and a miniature coil wound on the miniature soft magnetic core; the controller compartment (2) is provided with a mover controller for receiving commands and controlling the current of the miniature coil; the magnetic pole gap is the gap between adjacent permanent magnets in the permanent magnet sub-array unit or the inter-unit gap between adjacent permanent magnet sub-array units; The method is adjusted by controlling the magnetic field reconstruction unit (32), and includes the following steps: S1: Based on the magnetic field distribution data of the mover, obtain the adjustment parameters of the magnetic field reconstruction unit (32) that needs to be adjusted. The magnetic field distribution data includes the actual magnetic field distribution data and the target magnetic field distribution data. The adjustment parameters of the magnetic field reconstruction unit (32) include the number of the magnetic field reconstruction unit, the magnetic field strength and the magnetic field direction. S2: Based on the adjustment parameters of the magnetic field reconstruction unit (32), the current parameters of the corresponding magnetic field reconstruction unit are obtained through the magnetic field strength-current mapping table; S3: Based on the current parameters in step S2, drive the magnetic field reconstruction unit (32) to generate an additional magnetic field.

2. The magnetic field adjustment method for a magnetically levitated planar motor according to claim 1, characterized in that, The method for obtaining the current parameters of the magnetic field reconstruction unit in step S2 includes the following steps: S21: Call the magnetic field strength-current mapping table of the magnetic field reconstruction unit (32); S22: If the magnetic field strength of the magnetic field reconstruction unit (32) is a non-discrete value, the corresponding current is calculated by linear interpolation based on two adjacent discrete values ​​in the current mapping table of the magnetic field reconstruction unit (32); if the magnetic field strength of the magnetic field reconstruction unit (32) is a discrete value, the corresponding current is read directly.

3. The magnetic field adjustment method for a magnetically levitated planar motor according to claim 1, characterized in that, The method further includes the following steps: A1: Real-time magnetic field strength B is obtained through the Hall sensor array of the stator assembly (11). after ; A2: Based on the real-time magnetic field strength B after With the initial magnetic field strength B before Calculate the magnetic field compensation amount ΔB'=B before -B after The initial magnetic field strength is the magnetic field strength detected by the Hall sensor when the mover leaves the factory or when the permanent magnet is not aged; A3: Determine whether compensation is needed based on the magnetic field compensation amount ΔB' and the compensation threshold Bq; A4: If the magnetic field strength needs to be compensated, based on the adjustment parameters of the magnetic field reconstruction unit, the current parameters of the corresponding magnetic field reconstruction unit (32) are obtained through the magnetic field strength-current mapping table; A5: Based on the current parameters obtained in step A4, drive the magnetic field reconstruction unit (32) to generate an additional magnetic field.

4. The magnetic field adjustment method for a magnetically levitated planar motor according to claim 3, characterized in that, The method for obtaining real-time magnetic field strength using a Hall sensor array is as follows: A11: Obtain the real-time voltage value Vh output by the Hall sensor array; A12: The real-time voltage value is converted into real-time magnetic field strength B using a calibration coefficient K. after =K×Vh.

5. The magnetic field adjustment method for a magnetically levitated planar motor according to claim 3, characterized in that, The mover assembly (10) further includes a reinforcement layer disposed between the adjustable magnetic array layer (3) and the mover base plate (4); the reinforcement layer includes an array of reinforcement coils, the projection position of the reinforcement coils on the plane corresponding to the position of the permanent magnet array; The adjustment methods also include: A6: If the current in the miniature coil of the magnetic field reconstruction unit is Imax, and at this time B after +ΔB' before Initiate enhancement layer compensation;​ A7: A compensation current is passed through the reinforcement coil of the reinforcement layer, and the magnetic field generated by the compensation current is in the same direction as the magnetization direction of the corresponding permanent magnet.

6. The magnetic field adjustment method for a magnetically levitated planar motor according to claim 5, characterized in that, The method for calculating the compensation current is as follows: A71: Calculate the real-time magnetic field strength B after compensation by the magnetic field reconstruction unit (32). after +ΔB' and the initial magnetic field strength B before The average magnetic field deviation ΔBavg; A72: The compensation current of the reinforcement layer is obtained as Ie = ΔBavg / Ke, where Ke is the current-to-magnetic field conversion coefficient.

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