Distance measuring device of permanent magnet electromagnetic hybrid system

Abstract

The present invention provides a distance measuring device for a permanent magnet electromagnetic hybrid system, the permanent magnet electromagnetic hybrid system comprising an electromagnet and a permanent magnet. The distance measuring device comprises: at least two linear Hall elements spaced apart on the adsorption surface of the electromagnet, one of the linear Hall elements being located in the center of the adsorption surface, opposite the permanent magnet; the at least two linear Hall elements being used to obtain a magnetic field intensity electrical signal of a mixed magnetic field formed by the superposition of a permanent magnetic field generated by the permanent magnet and an electromagnetic field generated by an excitation current in the electromagnet; and a signal compensation module electrically connected to each linear Hall element, being used to compensate the magnetic field intensity electrical signal of the mixed magnetic field to offset the influence of the electromagnetic field, and outputting a compensated magnetic field intensity electrical signal related only to the permanent magnetic field to represent the distance between the electromagnet and the permanent magnet. The present invention can effectively reduce the influence of the sway and lateral deviation of the permanent magnet on the distance signal during measurement, thereby improving the accuracy of distance detection.

Description

Technical Field

[0001] The present invention relates to the technical field of distance detection, and in particular to a distance measuring device of a permanent magnet electromagnetic hybrid system. Background Art

[0002] In a permanent magnet electromagnetic hybrid suspension system, to achieve stable levitation, the distance between the permanent magnet and the electromagnet must be measured in real time to achieve dynamic balance control of the hybrid suspension system. Existing technologies commonly use laser ranging, infrared sensor ranging, ultrasonic ranging, light occlusion ranging, and linear Hall effect ranging. Laser ranging offers high accuracy but is expensive. Infrared sensor ranging is less expensive than laser ranging, but is significantly affected by ambient light sources. Ultrasonic ranging has low accuracy and a large ultrasonic generator, making it impractical. Light occlusion ranging is complex and inaccurate, failing to meet operational requirements. Linear Hall effect ranging elements are often used as distance detection elements in existing hybrid suspension systems due to their low price and high sensitivity. However, linear Hall effect ranging elements are susceptible to the electromagnetic field generated by the electromagnet, resulting in deviations in measurement results. This issue urgently needs to be addressed to improve measurement accuracy. Summary of the Invention

[0003] The purpose of the embodiment of the present invention is to provide a distance measuring device of a permanent magnet electromagnetic hybrid system, which is used to solve the problem that the existing linear Hall element is easily affected by the electromagnetic field generated by the electromagnet when measuring distance, causing deviation in the measurement result.

[0004] To achieve the above objectives, an embodiment of the present invention provides a distance measuring device for a permanent magnet electromagnetic hybrid system, wherein the permanent magnet electromagnetic hybrid system includes an electromagnet and a permanent magnet, wherein the bottom surface of the electromagnet is a horizontal adsorption surface, and the permanent magnet is located directly below the electromagnet and does not contact the electromagnet; the distance measuring device for the permanent magnet electromagnetic hybrid system includes:

[0005] At least two linear Hall elements are arranged at intervals on the adsorption surface of the electromagnet, one of the linear Hall elements is located in the center of the adsorption surface and opposite to the permanent magnet, and the at least two linear Hall elements are used to obtain a magnetic field strength electrical signal of a mixed magnetic field formed by the superposition of a permanent magnetic field excited by the permanent magnet and an electromagnetic magnetic field excited by the excitation current in the electromagnet;

[0006] a signal compensation module, electrically connected to each linear Hall element, for compensating the magnetic field strength electrical signal of the mixed magnetic field to offset the influence of the electromagnetic magnetic field, and outputting a compensated magnetic field strength electrical signal related only to the permanent magnetic field to represent the distance between the electromagnet and the permanent magnet;

[0007] A power supply module is connected to the electromagnet, the linear Hall element and the signal compensation module, and is used to supply power to the electromagnet, the linear Hall element and the signal compensation module.

[0008] Optionally, the electromagnet is an E-type electromagnet or an electromagnetic chuck.

[0009] Optionally, the permanent magnet is a neodymium iron boron permanent magnet, a samarium cobalt permanent magnet or an aluminum nickel cobalt permanent magnet, and the shape of the permanent magnet is a cylinder, a rectangular parallelepiped or a ring.

[0010] Optionally, the number of the linear Hall elements is three, which are arranged in a straight line at equal intervals on the adsorption surface, and the linear Hall element in the middle position is located in the middle of the adsorption surface and opposite to the permanent magnet.

[0011] Optionally, the number of the linear Hall elements is five, and one of the linear Hall elements is located in the center of the adsorption surface and opposite to the permanent magnet, and the remaining four linear Hall elements are equidistantly and rotationally symmetrically arranged on the periphery of the adsorption surface.

[0012] Optionally, the signal compensation module is a digital controller, and the digital controller uses the following formula to calculate the compensated magnetic field strength electric signal:

[0013]

[0014] Among them, U 补偿后 is the compensated magnetic field strength electrical signal; U0 is the magnetic field strength electrical signal of the mixed magnetic field obtained by the linear Hall element located in the middle of the adsorption surface; K is the compensation coefficient, U 调零 is the zero adjustment coefficient; i is the i-th linear Hall element located outside the adsorption surface, and i ≥ 1; n is the number of linear Hall elements located outside the adsorption surface; U i The electric signal of the magnetic field strength of the mixed magnetic field obtained by the linear Hall element located outside the adsorption surface.

[0015] Optionally, the signal compensation module is further configured to implement compensation coefficient calibration, including:

[0016] An alternating current of a specific frequency and amplitude is supplied to the electromagnet, and a magnetic field strength electric signal of the mixed magnetic field is obtained in real time through the linear Hall element;

[0017] Determine the sensitivity of the sum of the magnetic field strength electrical signal of the mixed magnetic field obtained by the linear Hall element located in the center of the adsorption surface and the magnetic field strength electrical signal of the mixed magnetic field obtained by the linear Hall element located at the periphery of the adsorption surface;

[0018] The sensitivity is determined as a compensation coefficient of the digital controller.

[0019] Optionally, the sensitivity is obtained by linear programming data fitting:

[0020]

[0021] Among them, U′0 is the magnetic field strength electrical signal of the mixed magnetic field obtained by the linear Hall element located in the middle of the adsorption surface, and U′ i is the magnetic field strength electrical signal of the mixed magnetic field obtained by the linear Hall element located on the periphery of the adsorption surface, i is the i-th linear Hall element located on the periphery of the adsorption surface, and i ≥ 1, n is the number of linear Hall elements located on the periphery of the adsorption surface; under the influence of the electromagnetic magnetic field, U′0 and The changes of the two are linearly related; K is the sum of U′0 and The sensitivity between them is , and C is the intercept.

[0022] Optionally, the signal compensation module is an analog circuit;

[0023] The analog circuit comprises: an input signal processing module and a parameter adjustment module connected in series;

[0024] The input signal processing module includes at least two first operational amplifiers, the output end of each first operational amplifier is connected to the input end of the parameter adjustment module through a first resistor, the non-inverting input end of each first operational amplifier is connected to the output end of the corresponding linear Hall element, and the inverting input end of each first operational amplifier is connected to the respective output end;

[0025] The parameter adjustment module includes a second operational amplifier and a third operational amplifier connected in series, the inverting input end of the second operational amplifier is connected to the output end of the input signal processing module and is also connected to the output end of the second operational amplifier through a second resistor, the non-inverting input end of the second operational amplifier is connected to an adjustable potentiometer, the output end of the second operational amplifier is connected to the non-inverting input end of the third operational amplifier, the inverting input end of the third operational amplifier is connected to the output end of the third operational amplifier, and the output end of the third operational amplifier outputs a compensated magnetic field strength electrical signal.

[0026] Optionally, the signal compensation module is further configured to implement calibration, including:

[0027] Passing alternating current of specific frequency and amplitude into the electromagnet;

[0028] The resistance value of the first resistor corresponding to the linear Hall element located in the center of the adsorption surface is adjusted, and the adjustable potentiometer is adjusted until the compensated magnetic field strength electric signal is a fixed value.

[0029] The present technical solution obtains the magnetic field strength electrical signal of the mixed magnetic field formed by the superposition of the permanent magnetic field and the electromagnetic magnetic field through at least two linear Hall elements, and uses a signal compensation module to compensate the magnetic field strength electrical signal of the mixed magnetic field to offset the influence of the electromagnetic magnetic field, and outputs the compensated magnetic field strength electrical signal related only to the permanent magnetic field, so as to characterize the distance between the electromagnet and the permanent magnet, avoid interference of the linear Hall element by the electromagnetic magnetic field, make the signal measurement more accurate, and improve the distance detection accuracy; in addition, by setting at least three linear Hall elements, the influence of the swaying and lateral deviation of the permanent magnet on the distance signal during the measurement process can be effectively reduced, thereby improving the accuracy of distance detection.

[0030] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following detailed description, they are used to explain the embodiments of the present invention, but do not constitute a limitation of the embodiments of the present invention. In the accompanying drawings:

[0032] Figure 1 This is a structural schematic diagram of a first type of distance measuring device of a permanent magnet electromagnetic hybrid system provided by the present invention;

[0033] Figure 2 This is a partial structural diagram of a distance measuring device of a first permanent magnet electromagnetic hybrid system provided by the present invention;

[0034] Figure 3 1 is a structural schematic diagram of a second type of distance measuring device of a permanent magnet electromagnetic hybrid system provided by the present invention;

[0035] Figure 4 This is a partial structural diagram of a distance measuring device of a second permanent magnet electromagnetic hybrid system provided by the present invention;

[0036] Figure 5 2. It is a structural schematic diagram of a signal compensation module of a distance measuring device of a permanent magnet electromagnetic hybrid system provided by the present invention;

[0037] Figure 6 Schematic diagram showing how the sum of the magnetic field strength electrical signal of the mixed magnetic field obtained by the linear Hall element located in the center of the adsorption surface and the magnetic field strength electrical signal of the mixed magnetic field obtained by the linear Hall element located on the periphery of the adsorption surface, respectively, changes with the excitation current in the electromagnet;

[0038] Figure 7Schematic diagram of the relationship between the sum of the magnetic field strength electrical signal of the mixed magnetic field obtained by the linear Hall element located in the center of the adsorption surface and the magnetic field strength electrical signal of the mixed magnetic field obtained by the linear Hall element located on the periphery of the adsorption surface provided by the present invention;

[0039] Figure 8 It is a schematic diagram of the relationship between the compensated magnetic field strength electric signal and the distance between the electromagnet and the permanent magnet provided by the present invention.

[0040] Description of Reference Numerals

[0041] 1-electromagnet; 2-permanent magnet; 3-linear Hall element;

[0042] 4-Signal compensation module; 41-Input signal processing module; 42-Parameter adjustment module;

[0043] 411 - first operational amplifier; 412 - first resistor; 421 - second operational amplifier;

[0044] 422 - a third operational amplifier; 423 - a second resistor; 424 - an adjustable potentiometer. DETAILED DESCRIPTION

[0045] The following describes the specific implementation of the embodiment of the present invention in detail with reference to the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the embodiment of the present invention and is not used to limit the embodiment of the present invention.

[0046] In the embodiments of the present invention, unless otherwise specified, directional words such as "up, down, left, right" generally refer to the orientation or position relationship shown in the accompanying drawings, or the orientation or position relationship in which the product of the invention is usually placed when in use.

[0047] The terms "first", "second", "third", etc. are only used for distinction and description and should not be understood as indicating or implying relative importance.

[0048] The terms "parallel" and "perpendicular" do not necessarily mean that the components must be absolutely parallel or perpendicular, but rather that they can be slightly tilted. For example, "parallel" simply means that the direction is more parallel than "perpendicular", not that the structure must be completely parallel, but rather that it can be slightly tilted.

[0049] Terms such as "horizontal," "vertical," and "overhanging" do not necessarily mean that a component must be absolutely horizontal, vertical, or overhanging. A slight tilt is permitted. For example, "horizontal" simply means that its direction is more horizontal than "vertical." It does not mean that the structure must be completely horizontal, but rather that a slight tilt is permitted.

[0050] Furthermore, terms like "approximately" and "substantially" are intended to clarify that the relevant content does not require absolute precision, but rather allows for certain deviations. For example, "approximately equal" does not simply mean absolute equality. Because absolute equality is difficult to achieve in actual production and operational processes, certain deviations generally exist. Therefore, in addition to absolute equality, "approximately equal" also encompasses the aforementioned situation of certain deviations. Taking this as an example, in other contexts, unless otherwise specified, terms like "approximately" and "substantially" have similar meanings as described above.

[0051] In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0052] Figure 1 This is a structural schematic diagram of a first type of distance measuring device of a permanent magnet electromagnetic hybrid system provided by the present invention; Figure 2 This is a partial structural diagram of a distance measuring device of a first permanent magnet electromagnetic hybrid system provided by the present invention; Figure 3 1 is a structural schematic diagram of a second type of distance measuring device of a permanent magnet electromagnetic hybrid system provided by the present invention; Figure 4 It is a partial structural schematic diagram of the distance measuring device of the second permanent magnet electromagnetic hybrid system provided by the present invention.

[0053] like Figure 1-4 As shown, an embodiment of the present invention provides a distance measuring device of a permanent magnet electromagnetic hybrid system, the permanent magnet electromagnetic hybrid system comprising: an electromagnet 1 and a permanent magnet 2, wherein the bottom surface of the electromagnet 1 is a horizontal adsorption surface, and the permanent magnet 2 is located directly below the electromagnet 1 and does not contact the electromagnet 1; the distance measuring device of the permanent magnet electromagnetic hybrid system comprises:

[0054] At least two linear Hall elements 3 are arranged at intervals on the adsorption surface of the electromagnet 1, one of the linear Hall elements 3 is located in the center of the adsorption surface and opposite to the permanent magnet 2, and the at least two linear Hall elements 3 are used to obtain a magnetic field strength electrical signal of a mixed magnetic field formed by the superposition of the permanent magnetic field excited by the permanent magnet 2 and the electromagnetic magnetic field excited by the excitation current in the electromagnet 1;

[0055] a signal compensation module 4, electrically connected to each linear Hall element 3, for compensating the magnetic field strength electrical signal of the mixed magnetic field to offset the influence of the electromagnetic magnetic field, and outputting a compensated magnetic field strength electrical signal related only to the permanent magnetic field to represent the distance between the electromagnet 1 and the permanent magnet 2;

[0056] A power supply module is connected to the electromagnet 1 , the linear Hall element 3 and the signal compensation module 4 , and is used to supply power to the electromagnet 1 , the linear Hall element 3 and the signal compensation module 4 .

[0057] Specifically, the electromagnet 1 comprises an iron core and a coil. When an excitation current is passed through the coil, the electromagnet 1 generates an electromagnetic magnetic field, the direction of which is determined by the direction of the excitation current. Simultaneously, the permanent magnet 2 generates a permanent magnetic field. The interaction between the permanent magnetic field, the iron core of the electromagnet 1, and the electromagnetic field generates a magnetic field force between the permanent magnet 2 and the electromagnet 1. The number of linear Hall elements 3 depends on actual usage and can range from two to five or more. They are arranged according to a specific pattern, ensuring that one linear Hall element 3 is located in the center of the adsorption surface. After the linear Hall element 3 receives the magnetic field strength signal of the mixed magnetic field, the signal compensation module 4, which can use a digital controller or an analog circuit, compensates the magnetic field strength signal of the mixed magnetic field to offset the influence of the electromagnetic field and outputs a compensated magnetic field strength signal related only to the permanent magnetic field, which is used to represent the distance between the electromagnet 1 and the permanent magnet 2.

[0058] More specifically, the signal compensation module 4 can determine the actual distance between the permanent magnet 2 and the electromagnet 1 according to the functional relationship between the distance and the compensated magnetic field strength electrical signal.

[0059] More specifically, the power supply (not shown) can be provided as a whole or individually to supply power to the electromagnet 1, the linear Hall element 3 or the signal compensation module 4, specifically including disposable batteries, rechargeable batteries, etc. as power sources.

[0060] Furthermore, the present invention is implemented based on the following principles:

[0061] According to the linear superposition principle of magnetic fields, the mixed magnetic field obtained by the linear Hall element 3 can be linearly decomposed into the permanent magnetic field B 永 and electromagnetic field B 电 ; Among them, the permanent magnetic field B 永 Affected by the distance h between the electromagnet 1 and the permanent magnet 2 and the magnetization degree α of the core of the electromagnet 1 near the linear Hall element 3; the electromagnetic magnetic field B 电Affected by the excitation current I of the electromagnet 1 and the position coefficient β of the linear Hall element 3. Since the permanent magnet 2 cannot be further magnetized or demagnetized, the permanent magnetic field B 永 It has nothing to do with the excitation current I; the multiple linear Hall elements 3 are positively correlated with each other under the influence of the electromagnetic magnetic field, which is characterized by the position coefficient β. The position coefficient β is a constant and has nothing to do with the excitation current I and the distance h.

[0062] In summary, the mixed magnetic field obtained by each linear Hall element 3 has the following functional relationship:

[0063] B0=B 永 (h)+B 电 (I)

[0064] B i =α i (h)B 永 (h)+β i B 电 (I)

[0065] Among them, β i As a constant, the electromagnetic magnetic field B can be directly measured and 电 Compensation is performed. Let the compensated magnetic field B 补偿后 is the following expression:

[0066]

[0067] From the above formula, we can know that the magnetic field B after compensation is 补偿后 It has nothing to do with the excitation current I, but only with the distance h, which can characterize the distance between the permanent magnet 2 and the electromagnet 1.

[0068] Furthermore, the electromagnet 1 is an E-type electromagnet 1 or an electromagnetic chuck.

[0069] Specifically, the electromagnet 1 can be an E-type electromagnet or an electromagnetic chuck, and when an E-type electromagnet is used, its open end is vertically downward and arranged relative to the permanent magnet 2; in addition, when an E-type electromagnet is used, three linear Hall elements 3 can be provided, and one of the linear Hall elements 3 is located in the center of the adsorption surface of the E-type electromagnet, and the three linear Hall elements 3 are arranged in a straight line on the iron core of the E-type electromagnet; when an electromagnetic chuck is used, five linear Hall elements 3 are provided, and one of the linear Hall elements 3 is located in the center of the adsorption surface of the electromagnetic chuck, and the remaining four linear Hall elements 3 are equidistant and rotationally symmetrically arranged on the adsorption surface of the electromagnetic chuck.

[0070] Furthermore, the permanent magnet 2 is a neodymium iron boron permanent magnet, a samarium cobalt permanent magnet or an aluminum nickel cobalt permanent magnet, and the shape of the permanent magnet 2 is a cylinder, a cuboid or a ring.

[0071] Specifically, the permanent magnet 2 can be a permanent magnet with strong magnetism such as neodymium iron boron permanent magnet, samarium cobalt permanent magnet or alnico permanent magnet, and the shape can be cylindrical, rectangular or ring-shaped, etc., which can be determined according to the actual use environment.

[0072] Furthermore, the number 3 of the linear Hall elements 3 is three, which are arranged in a straight line at equal intervals on the adsorption surface, and the linear Hall element 3 in the middle is located in the middle of the adsorption surface and opposite to the permanent magnet 2.

[0073] Specifically, if Figure 1-2 As shown, when there are three linear Hall elements 3, one of the linear Hall elements 3 is located in the middle of the adsorption surface of the electromagnet 1, and the three linear Hall elements 3 are symmetrically distributed at equal distances. The most preferred arrangement is in a straight line, which can effectively reduce the influence of the swing and lateral deviation of the permanent magnet 2 on the distance signal during the measurement process and improve the accuracy of distance detection. When there are three linear Hall elements 3, it can be applied to an E-type electromagnet.

[0074] Furthermore, the number of the linear Hall elements 3 is five, and one of the linear Hall elements 3 is located in the center of the adsorption surface and opposite to the permanent magnet 2, and the remaining four linear Hall elements 3 are equidistantly and rotationally symmetrically arranged on the periphery of the adsorption surface.

[0075] Specifically, if Figure 3-4 As shown, when there are five linear Hall elements 3, one of the linear Hall elements 3 is located in the middle of the adsorption surface of the electromagnet 1, and the remaining four linear Hall elements 3 are equidistantly and rotationally symmetrically distributed on the adsorption surface of the electromagnet 1, located on the periphery of the adsorption surface, and the four linear Hall elements 3 are equidistant from the linear Hall element 3 located in the middle of the adsorption surface of the electromagnet 1. This arrangement can effectively reduce the influence of the swing and lateral deviation of the permanent magnet 2 on the distance signal during the measurement process, thereby improving the accuracy of distance detection. When there are five linear Hall elements 3, it can be applied to an electromagnetic chuck.

[0076] Furthermore, the signal compensation module 4 is a digital controller, which uses the following formula to calculate the compensated magnetic field strength electric signal:

[0077]

[0078] Among them, U 补偿后 is the compensated magnetic field strength electrical signal; U0 is the magnetic field strength electrical signal of the mixed magnetic field obtained by the linear Hall element located in the middle of the adsorption surface; K is the compensation coefficient, U 调零 is the zero adjustment coefficient; i is the i-th linear Hall element located outside the adsorption surface, and i ≥ 1; n is the number of linear Hall elements located outside the adsorption surface; Ui The magnetic field strength electrical signal of the mixed magnetic field obtained by the linear Hall element located outside the adsorption surface

[0079] Specifically, when the signal compensation module 4 is a digital controller, the compensation formula is used. The magnetic field strength electrical signal of the input mixed magnetic field is compensated to offset the influence of the electromagnetic magnetic field, and a compensated magnetic field strength electrical signal related only to the permanent magnetic field is output to represent the distance between the electromagnet 1 and the permanent magnet 2.

[0080] Furthermore, the signal compensation module 4 is also used to implement compensation coefficient calibration, including:

[0081] An alternating current of a specific frequency and amplitude is supplied to the electromagnet 1, and an electric signal of the magnetic field strength of the mixed magnetic field is obtained in real time through the linear Hall element 3;

[0082] Determine the sensitivity of the sum of the magnetic field strength electrical signal of the mixed magnetic field obtained by the linear Hall element 3 located in the center of the adsorption surface and the magnetic field strength electrical signal of the mixed magnetic field obtained by the linear Hall element 3 located at the periphery of the adsorption surface;

[0083] The sensitivity is determined as a compensation coefficient of the digital controller.

[0084] Specifically, the permanent magnet 2 is removed, and alternating current of a specific frequency and amplitude is passed through the electromagnet 1. The magnetic field strength electric signal of the electromagnetic magnetic field is obtained in real time through the linear Hall element 3. At this time, the signal is only related to the excitation current passed through the electromagnet 1. The sensitivity between the magnetic field strength electric signal obtained by the linear Hall element 3 located in the center of the adsorption surface and the magnetic field strength electric signal obtained by the linear Hall element 3 located on the periphery of the adsorption surface is determined by using a data analysis method. The sensitivity is determined as the compensation coefficient of the digital controller, so that the digital controller compensates the magnetic field strength electric signal of the mixed magnetic field to offset the influence of the electromagnetic magnetic field, and outputs a compensated magnetic field strength electric signal related only to the permanent magnetic field to characterize the distance between the electromagnet 1 and the permanent magnet 2.

[0085] Furthermore, the sensitivity is obtained by linear programming data fitting:

[0086]

[0087] Among them, U′0 is the magnetic field strength electrical signal of the mixed magnetic field obtained by the linear Hall element located in the middle of the adsorption surface, and U′ iis the magnetic field strength electrical signal of the mixed magnetic field obtained by the linear Hall element located on the periphery of the adsorption surface, i is the i-th linear Hall element located on the periphery of the adsorption surface, and i ≥ 1, n is the number of linear Hall elements located on the periphery of the adsorption surface; under the influence of the electromagnetic magnetic field, U′0 and The changes of the two are linearly related; K is the sum of U′0 and The sensitivity between them is , and C is the intercept.

[0088] More specifically, in this embodiment, five linear Hall elements 3 are provided, and the magnetic field strength electric signal of the mixed magnetic field obtained by the linear Hall element 3 located in the center of the adsorption surface is recorded as U'0, and the magnetic field strength electric signal of the mixed magnetic field obtained by the linear Hall element 3 located at the periphery of the adsorption surface is recorded as U' i , U′2, U′3, U′4; After obtaining the magnetic field strength electrical signals of the five linear Hall elements 3, linear programming is used to perform data fitting to obtain an approximate relationship between the sum of the magnetic field strength electrical signals obtained by the linear Hall element 3 located in the center of the adsorption surface and the magnetic field strength electrical signals obtained by the linear Hall element 3 located on the periphery of the adsorption surface:

[0089]

[0090] Where K is the sum of U′0 and The sensitivity between can be used as the compensation coefficient of the digital controller; C is the intercept.

[0091] On the other hand, when the signal compensation module 4 is an analog circuit, the signal compensation module 4 is calibrated using the following calibration method:

[0092] The signal compensation module 4 is an analog circuit;

[0093] The analog circuit comprises: an input signal processing module 41 and a parameter adjustment module 42 connected in series;

[0094] The input signal processing module 41 includes at least two first operational amplifiers 411. The output of each first operational amplifier 411 is connected to the input of the parameter adjustment module 42 via a first resistor 412. The non-inverting input of each first operational amplifier 411 is connected to the output of the corresponding linear Hall element 3. The inverting input of each first operational amplifier 411 is connected to the output of the corresponding linear Hall element 3.

[0095] The parameter adjustment module 42 includes a second operational amplifier 421 and a third operational amplifier 422 connected in series, the inverting input end of the second operational amplifier 421 is connected to the output end of the input signal processing module 41 and is also connected to the output end of the second operational amplifier 421 through a second resistor 423, the non-inverting input end of the second operational amplifier 421 is connected to the adjustable potentiometer 424, the output end of the second operational amplifier 421 is connected to the non-inverting input end of the third operational amplifier 422, the inverting input end of the third operational amplifier 422 is connected to the output end of the third operational amplifier 422, and the output end of the third operational amplifier 422 outputs the compensated magnetic field strength electrical signal.

[0096] Specifically, Figure 5 Schematic diagram of the structure of the signal compensation module of the distance measuring device of the permanent magnet electromagnetic hybrid system provided by the present invention. Figure 5 As shown, in this embodiment, five linear Hall elements 3 are provided, and the analog circuit includes an input signal processing module 41 and a parameter adjustment module 42 connected in series. The input signal processing module 41 includes five first operational amplifiers 411. The output end of each first operational amplifier 411 is connected to the input end of the parameter adjustment module 42 through a first resistor 412. The same-direction input end of each first operational amplifier 411 is connected to the output end of the corresponding linear Hall element 3, and the reverse input end of each first operational amplifier 411 is connected to the respective output end; the parameter adjustment module 42 includes second operational amplifiers 42 connected in series. 1 and a third operational amplifier 422, the inverting input terminal of the second operational amplifier 421 is connected to the output terminal of the input signal processing module 41 and is also connected to the output terminal of the second operational amplifier 421 through a second resistor 423, the non-inverting input terminal of the second operational amplifier 421 is connected to the adjustable potentiometer 424, the output terminal of the second operational amplifier 421 is connected to the non-inverting input terminal of the third operational amplifier 422, the inverting input terminal of the third operational amplifier 422 is connected to the output terminal of the third operational amplifier 422, and the output terminal of the third operational amplifier 422 outputs the compensated magnetic field strength electrical signal. Among them, the number of first operational amplifiers 411 and first resistors 412 is the same as the number of linear Hall elements 3, and the first resistor 412 and the second resistor 423 can both adopt sliding resistors, variable resistor boxes, etc.; further, the first resistor 412 corresponding to the linear Hall element 3 located in the center of the adsorption surface adopts a sliding resistor, and the first resistor 412 corresponding to the linear Hall element 3 located on the periphery of the adsorption surface can adopt a fixed resistance resistor; in addition, by adjusting the resistance value of the second resistor 423, the sensitivity of the analog circuit to the permanent magnetic field can be adjusted; by adjusting the adjustable potentiometer 424, the analog circuit can be zeroed.

[0097] In this embodiment, the first resistor 412 corresponding to the linear Hall element 3 located in the center of the adsorption surface is VR0. The first resistors 412 corresponding to the peripheral linear Hall elements 3 are R1, R2, R3, and R4, respectively. In actual applications, the first resistors 412 of the peripheral linear Hall elements 3 are set to the same value.

[0098] Furthermore, the signal compensation module 4 is also used to implement calibration, specifically including:

[0099] Passing alternating current of specific frequency and amplitude into the electromagnet 1;

[0100] The resistance value of the first resistor 412 corresponding to the linear Hall element 3 located in the center of the adsorption surface and the adjustable potentiometer 424 are adjusted until the compensated magnetic field strength electric signal is a fixed value.

[0101] Specifically, the permanent magnet 2 is removed, and alternating current of a specific frequency and amplitude is passed through the electromagnet 1. The magnetic field strength electrical signal of the mixed magnetic field is obtained in real time through the linear Hall element 3. By adjusting the resistance value VR0 of the first resistor 412 corresponding to the linear Hall element 3 located in the center of the adsorption surface and adjusting the adjustable potentiometer 424, the compensated magnetic field strength electrical signal can be finally stabilized to a fixed value of appropriate size. In the subsequent distance detection process, the magnetic field strength electrical signal of the mixed magnetic field can be compensated to offset the influence of the electromagnetic magnetic field, and a compensated magnetic field strength electrical signal related only to the permanent magnetic field is output to represent the distance between the electromagnet 1 and the permanent magnet 2.

[0102] Specifically, signal compensation is performed by an analog circuit.

[0103] Taking the setting of five linear Hall elements 3 as an example, five magnetic field strength electrical signals are obtained respectively: U0, U1, U2, U3 and U4; among them, U0 is the magnetic field strength electrical signal of the mixed magnetic field obtained by the linear Hall element 3 located in the center of the adsorption surface, which is greatly affected by the permanent magnetic field; U1, U2, U3, and U4 are the magnetic field strength electrical signals of the mixed magnetic field obtained by the other four linear Hall elements 3 arranged on the periphery of the adsorption surface. The four linear Hall elements 3 are geometrically equidistant and rotationally symmetric and are less affected by the permanent magnetic field.

[0104] The purpose of this analog circuit is to exploit the linear relationship between the electromagnetic field strength signals obtained by multiple linear Hall elements 3, thereby canceling out the effects of the electromagnetic field and outputting a compensated magnetic field strength signal related only to the permanent magnetic field. If the linear Hall elements 3 are positioned in the same orientation on the adsorption surface of electromagnet 1 (e.g., with the working surface of the linear Hall elements 3 facing electromagnet 1), the electromagnetic field's effect on U0 is opposite to its effect on U1, U2, U3, and U4. For example, as U0 increases, U1, U2, U3, and U4 decrease.

[0105] The following relationship can be obtained from the circuit analysis of the second operational amplifier 421:

[0106]

[0107] Among them, R1=R2=R3=R4. Further simplification can be obtained,

[0108]

[0109] Among them, U 补偿后 is the compensated magnetic field strength electrical signal output by the third operational amplifier; U0 and The sensitivity between them can be regarded as the compensation coefficient of the analog circuit; U 调零 is the zero adjustment factor, generated by the adjustable potentiometer.

[0110] From the above formula, we can know that fine-tuning VR0 can offset the effect of electromagnetic magnetic field on U 补偿后 Impact; Fine-tuning VR 第二 , can adjust the sensitivity of the analog circuit to the permanent magnetic field; fine-tune U 调零 , the output signal of the analog circuit can be zeroed.

[0111] Example 1

[0112] like Figure 1-2 As shown, in this embodiment, the electromagnet 1 is an E-shaped electromagnet; the permanent magnet 2 is a rectangular parallelepiped; three linear Hall elements 3 are arranged on the adsorption surface of the E-shaped electromagnet, equidistantly spaced in a straight line, with the center linear Hall element 3 located in the center of the adsorption surface and facing the permanent magnet 2. A signal compensation module 4 is also provided on the adsorption surface. This signal detection method effectively reduces the impact of the sway and lateral deviation of the permanent magnet 2 on the distance signal during measurement, thereby improving the accuracy of distance detection.

[0113] Example 2

[0114] like Figure 3-4As shown, in this embodiment, the electromagnet 1 is an electromagnetic chuck; the permanent magnet 2 is cylindrical; five linear Hall elements 3 are disposed on the suction surface of the electromagnetic chuck, one of which is located in the center of the suction surface of the electromagnet 1. The remaining four linear Hall elements 3 are equidistantly and rotationally symmetrically distributed on the suction surface of the electromagnet 1, located on the periphery of the suction surface. These four linear Hall elements 3 are equidistant from the linear Hall element 3 located in the center of the suction surface of the electromagnet 1. A signal compensation module 4 is disposed on the suction surface. Performing signal detection in this manner effectively reduces the impact of the sway and lateral deviation of the permanent magnet 2 on the distance signal during measurement, thereby improving the accuracy of distance detection.

[0115] Example 3

[0116] Figure 6 Schematic diagram showing how the sum of the magnetic field strength electrical signal of the mixed magnetic field obtained by the linear Hall element located in the center of the adsorption surface and the magnetic field strength electrical signal of the mixed magnetic field obtained by the linear Hall element located on the periphery of the adsorption surface, respectively, changes with the excitation current in the electromagnet; Figure 7 Schematic diagram of the relationship between the sum of the magnetic field strength electrical signal of the mixed magnetic field obtained by the linear Hall element located in the center of the adsorption surface and the magnetic field strength electrical signal of the mixed magnetic field obtained by the linear Hall element located on the periphery of the adsorption surface provided by the present invention; Figure 8 Schematic diagram of the relationship between the compensated magnetic field strength electric signal and the distance between the electromagnet and the permanent magnet provided by the present invention; Figure 6-8 As shown, this embodiment provides a calibration method for a distance measuring device of a permanent magnet electromagnetic hybrid system, wherein the signal compensation module 4 is an analog circuit, and the distance measuring device includes five linear Hall elements 3, and one of the linear Hall elements 3 is located in the center of the adsorption surface and opposite to the permanent magnet 2, and the remaining four linear Hall elements 3 are equidistantly and rotationally symmetrically arranged on the periphery of the adsorption surface. Let the resistance value of the first resistor 412 corresponding to the linear Hall element 3 located on the periphery be 90 kilo-ohms. Remove the permanent magnet 2, and pass an alternating current of a specific frequency and amplitude into the electromagnet 1, and obtain the magnetic field strength electric signal of the mixed magnetic field in real time through the linear Hall element 3. It can be obtained that the sum of the magnetic field strength electric signal of the mixed magnetic field obtained by the linear Hall element 3 located in the center of the adsorption surface and the magnetic field strength electric signal of the mixed magnetic field obtained by the linear Hall element 3 located on the periphery of the adsorption surface changes with the excitation current in the electromagnet 1, as shown in FIG. Figure 6 As shown. Then, by using linear programming to fit the data, we can obtain the relationship between the sum of the magnetic field strength electrical signal of the mixed magnetic field obtained by the linear Hall element 3 located in the center of the adsorption surface and the magnetic field strength electrical signal of the mixed magnetic field obtained by the linear Hall element 3 located outside the adsorption surface. The equation As you can see, just set That is, VR0=1.88×90=169.2 kΩ, and the resistance of the first resistor 412 corresponding to the linear Hall element 3 located in the middle of the adsorption surface is 169.2 kΩ. Figure 7 As shown. Before performing distance detection, the resistance value of the first resistor 412 corresponding to the linear Hall element 3 located in the center of the adsorption surface is adjusted to 169.2 kilo-ohms, and then the magnetic field strength electrical signal of the mixed magnetic field obtained by the linear Hall element 3 is compensated to offset the influence of the electromagnetic magnetic field, and the compensated magnetic field strength electrical signal related only to the permanent magnetic field is output. Furthermore, the signal compensation module 4 can determine the actual distance between the permanent magnet 2 and the electromagnet 1 based on the functional relationship between the distance and the compensated magnetic field strength electrical signal, as shown in FIG. Figure 8 As shown, under three different excitation currents (0mA, 100mA, -100mA), the compensated magnetic field strength electrical signals output by the signal compensation module 4 are almost the same, indicating that the compensated magnetic field strength electrical signals are no longer affected by the electromagnetic magnetic field and are only related to the permanent magnetic field.

[0117] In addition, if the signal compensation module 4 is a digital controller, the compensation coefficient is set to K=1.88, and signal compensation and distance detection can be performed.

[0118] The above describes in detail the optional implementation methods of the embodiments of the present invention in conjunction with the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details in the above implementation methods. Within the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical solutions of the embodiments of the present invention, and these simple modifications all fall within the scope of protection of the embodiments of the present invention.

[0119] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. To avoid unnecessary repetition, the embodiments of the present invention will not further describe various possible combinations.

[0120] Those skilled in the art will understand that all or part of the steps in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a program, which is stored in a storage medium and includes a number of instructions for causing a single-chip microcomputer, chip or processor to execute all or part of the steps of the methods described in each embodiment of the present application. The aforementioned storage medium includes: a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and other media that can store program code.

[0121] In addition, various implementations of the embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the embodiments of the present invention, they should also be regarded as the contents disclosed in the embodiments of the present invention.

Claims

1. A distance measuring device of a permanent magnet electromagnetic hybrid system, the permanent magnet electromagnetic hybrid system comprising an electromagnet (1) and a permanent magnet (2), the bottom surface of the electromagnet (1) being a horizontal adsorption surface, the permanent magnet (2) being located directly below the electromagnet (1) and not in contact with the electromagnet (1); characterized in that: The distance measuring device of the permanent magnet electromagnetic hybrid system includes: At least two linear Hall elements (3) are arranged at intervals on the adsorption surface of the electromagnet (1), one of the linear Hall elements (3) is located in the center of the adsorption surface and opposite to the permanent magnet (2), and the at least two linear Hall elements (3) are used to obtain a magnetic field intensity electric signal of a mixed magnetic field obtained by superimposing a permanent magnetic field excited by the permanent magnet (2) and an electromagnetic magnetic field excited by an excitation current in the electromagnet (1); a signal compensation module (4), electrically connected to each linear Hall element (3), for compensating the magnetic field strength electrical signal of the mixed magnetic field to offset the influence of the electromagnetic magnetic field, and outputting a compensated magnetic field strength electrical signal related only to the permanent magnetic field, for representing the distance between the electromagnet (1) and the permanent magnet (2); a power supply module connected to the electromagnet (1), the linear Hall element (3) and the signal compensation module (4), and used to supply power to the electromagnet (1), the linear Hall element (3) and the signal compensation module (4); The signal compensation module (4) is a digital controller, and the digital controller uses the following formula to calculate the compensated magnetic field strength electric signal: in, is the compensated magnetic field strength electrical signal; The electric signal of the magnetic field strength of the mixed magnetic field obtained by the linear Hall element located in the middle of the adsorption surface; is the compensation coefficient, is the zero adjustment coefficient; is located outside the adsorption surface linear Hall element, and ; is the number of linear Hall elements located outside the adsorption surface; The electric signal of the magnetic field strength of the mixed magnetic field obtained by the linear Hall element located outside the adsorption surface.

2. The distance measuring device of the permanent magnet electromagnetic hybrid system according to claim 1, characterized in that: The electromagnet (1) is an E-type electromagnet or an electromagnetic chuck.

3. The distance measuring device of the permanent magnet electromagnetic hybrid system according to claim 1, characterized in that: The permanent magnet (2) is a neodymium iron boron permanent magnet, a samarium cobalt permanent magnet or an aluminum nickel cobalt permanent magnet, and the shape of the permanent magnet (2) is a cylinder, a rectangular parallelepiped or a ring.

4. The distance measuring device of the permanent magnet electromagnetic hybrid system according to claim 1, characterized in that: The number of the linear Hall elements (3) is three, and they are arranged in a straight line with equal spacing on the adsorption surface, and the linear Hall element (3) in the middle position is located in the middle of the adsorption surface and is opposite to the permanent magnet (2).

5. The distance measuring device of the permanent magnet electromagnetic hybrid system according to claim 1, characterized in that: The number of the linear Hall elements (3) is five, and one of the linear Hall elements (3) is located in the center of the adsorption surface and opposite to the permanent magnet (2), and the remaining four linear Hall elements (3) are arranged at equal intervals and rotationally symmetrically on the periphery of the adsorption surface.

6. The distance measuring device of the permanent magnet electromagnetic hybrid system according to claim 1, characterized in that: The signal compensation module (4) is also used to implement compensation coefficient calibration, including: An alternating current of a specific frequency and amplitude is supplied to the electromagnet (1), and an electric signal of the magnetic field strength of the mixed magnetic field is obtained in real time through the linear Hall element (3); Determine the sensitivity of the sum of the magnetic field strength electric signal of the mixed magnetic field obtained by the linear Hall element (3) located in the center of the adsorption surface and the magnetic field strength electric signal of the mixed magnetic field obtained by the linear Hall element (3) located on the periphery of the adsorption surface; The sensitivity is determined as a compensation coefficient of the digital controller.

7. The distance measuring device of the permanent magnet electromagnetic hybrid system according to claim 6, characterized in that: The sensitivity is obtained by linear programming data fitting: in, The electric signal of the magnetic field strength of the mixed magnetic field obtained by the linear Hall element located in the middle of the adsorption surface is: The electric signal of the magnetic field strength of the mixed magnetic field obtained by the linear Hall element located outside the adsorption surface is is located outside the adsorption surface linear Hall element, and , is the number of linear Hall elements located outside the adsorption surface; under the influence of the electromagnetic magnetic field, and The changes in the two are linearly correlated; for and The sensitivity between is the intercept.

8. The distance measuring device of the permanent magnet electromagnetic hybrid system according to any one of claims 1 to 5, characterized in that: The signal compensation module (4) may also be an analog circuit; The analog circuit comprises: an input signal processing module (41) and a parameter adjustment module (42) connected in series; The input signal processing module (41) includes at least two first operational amplifiers (411), the output end of each first operational amplifier (411) is connected to the input end of the parameter adjustment module (42) via a first resistor (412), the non-inverting input end of each first operational amplifier (411) is connected to the output end of the corresponding linear Hall element (3), and the inverting input end of each first operational amplifier (411) is connected to the respective output end; The parameter adjustment module (42) comprises a second operational amplifier (421) and a third operational amplifier (422) connected in series, the inverting input end of the second operational amplifier (421) is connected to the output end of the input signal processing module (41) and is also connected to the output end of the second operational amplifier (421) via a second resistor (423), the non-inverting input end of the second operational amplifier (421) is connected to an adjustable potentiometer (424), the output end of the second operational amplifier (421) is connected to the non-inverting input end of the third operational amplifier (422), the inverting input end of the third operational amplifier (422) is connected to the output end of the third operational amplifier (422), and the output end of the third operational amplifier (422) outputs a compensated magnetic field strength electric signal.

9. The distance measuring device of the permanent magnet electromagnetic hybrid system according to claim 8, characterized in that: The signal compensation module (4) is also used to implement calibration, including: Passing alternating current of specific frequency and amplitude into the electromagnet (1); The resistance value of the first resistor (412) corresponding to the linear Hall element (3) located in the center of the adsorption surface is adjusted, and the adjustable potentiometer (424) is adjusted until the compensated magnetic field strength electric signal reaches a fixed value.

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