CN115276474A

CN115276474A - Magnetic suspension device

Info

Publication number: CN115276474A
Application number: CN202210813353.8A
Authority: CN
Inventors: 邓舒同; 刘�英; 何云飞; 邹圣楠; 陈鹏荣; 刘畅; 褚褚
Original assignee: Quanzhou Institute of Equipment Manufacturing
Current assignee: Quanzhou Institute of Equipment Manufacturing
Priority date: 2022-07-11
Filing date: 2022-07-11
Publication date: 2022-11-01

Abstract

The invention discloses a magnetic suspension device, which comprises a floater, a magnetic base and a controller, wherein the floater is arranged on the magnetic base; the magnetic base comprises a chassis, 2 or 3 magnet exciting coils, a permanent magnet array and a floater position monitoring unit; the chassis is an installation surface of the excitation coil and the permanent magnet array; the floater position monitoring unit is arranged at the center point of the chassis and used for detecting the current position of the floater on the suspension plane in real time and transmitting the current position to the controller; the controller compares the current position value with the target position value to generate a position deviation signal, and changes the current magnitude and direction in all the excitation coils by combining the stress analysis and the calculation result of the electromagnetic force of the excitation coils and the floater so as to enable the resultant force F of all the excitation coils to the floater_PThe float can be pulled to a target position value. The invention breaks through the limitation that only one direction freedom degree can be controlled by using a group of 2 coils in pairs, can save space and materials, and is beneficial to the miniaturization of the magnetic suspension device.

Description

Magnetic suspension device

Technical Field

The invention relates to a magnetic suspension device, in particular to a magnetic repulsion type magnetic suspension device.

Background

The existing push-down magnetic repulsion type magnetic suspension device has the basic principle that a floater is positioned at the center of the upper part, an excitation coil and an annular magnet are arranged below the floater, the repulsion force generated by the annular magnet is balanced with the gravity of the floater, and the electromagnetic resultant force generated by the excitation coil can control the stability of a suspended floater, so that the floater can be stably suspended at the center of the annular magnet. The number of the exciting coils is generally 4 (patent CN1819436A, patent CN 110677075A) or more (patent US20070170798 A1), and the basic principle is that one set of 2 coils in a pair controls the degree of freedom of the floater in the horizontal x direction, and the other set of 2 coils in a pair controls the degree of freedom of the floater in the horizontal y direction, so that the number of the exciting coils in the existing push-down magnetic repulsion type magnetic suspension device is at least 4, and the exciting coils appear in pairs.

With the increasing demand for miniaturization of magnetic levitation devices, it is a direction of research on how the device can be reduced in size. The solution of miniaturization by reducing the number of exciting coils has not been solved well.

Disclosure of Invention

In view of this, the invention provides a scheme for realizing stable suspension of the push-down magnetic repulsion type magnetic suspension device by using a smaller number of excitation coils, and the scheme realizes suspension by using 2 or 3 excitation coils, breaks through the limitation that only one pair of 2 coils is used for controlling the degree of freedom in a certain direction, can save space and materials, is beneficial to the miniaturization of the magnetic suspension device, and is beneficial to the expansion of the application scene of the magnetic suspension device.

In order to solve the above-mentioned technical problems, the present invention has been accomplished as described above.

A magnetic levitation apparatus comprising: the device comprises a floater, a magnetic base and a controller; the floater is a cylindrical permanent magnet; the magnetic base comprises a chassis, 2 or 3 magnet exciting coils, a permanent magnet array and a floater position monitoring unit;

the chassis is an installation surface of the excitation coil and the permanent magnet array; all field coils and permanent magnet arraysThe center of the chassis is taken as a central point Q and the two are symmetrically distributed; the ring line formed by the centers of all the permanent magnets in the permanent magnet array is positioned outside the ring line formed by the centers of all the magnet exciting coils; the floater position monitoring unit is arranged at the central point Q and is used for detecting the current position P (x) of the floater on the suspension plane in real time_p,y_p) And transmitted to the controller;

the controller compares the current position value P (x)_p,y_p) Comparing with the target position value to generate a position deviation signal, combining the calculation results of the stress analysis and the electromagnetic force of the exciting coil and the floater, and changing the current magnitude and direction in all the exciting coils to ensure that the resultant force F of all the exciting coils to the floater_PThe float can be pulled to a target position value.

Wherein, the number of the magnet exciting coils is 2, and when the target position value of the control is the balance position point O (0, 0):

a plane rectangular coordinate system is established by taking a horizontal plane where the center points of the excitation coils are located as a reference plane, taking a connecting line of the center points A and B of the two excitation coils A and B as an x axis and taking a vertical bisector of a line segment AB as a y axis; vertically projecting the attractive forces of two excitation coils on a reference surface, wherein the projected attractive forces are respectively F_AAnd F_B；F_AAnd F_BIs recorded as | F_A|、|F_B|；

From F_A、F_BMathematical expression of

And

a resultant force F can be obtained_A+F_BBy adjusting | F in the mathematical expression_A|、|F_BThe size of | can be combined to form the current float position P (x)_p,y_p) Resultant force F directed to equilibrium position O (0, 0)_P＝-μ(x_pe_x+y_pe_y)，F_PThe float can be pulled back to the equilibrium position; wherein a is the length of the line segment AB and mu is a real coefficient; e.g. of the type_x、e_yRespectively, x-axis and y-axis unit vectors.

Preferably, when | F_A|、|F_BI satisfy

In time, a suitable resultant force F can be combined_P＝-μ(x_pe_x+y_pe_y) Wherein the coefficient

F_PThe float being movable from a current position P (x)_p,y_p) Pulling back to the equilibrium position.

Wherein, the number of the magnet exciting coils (3) is 3, and when the target position value of the control is the balance position point O (0, 0):

the horizontal plane where the center points of the excitation coils are located is used as a reference surface, the center points A, B and C of the three excitation coils A, B and C form an equilateral triangle, the center O point of the equilateral triangle ABC is used as a coordinate origin, and OA is used as a y-axis direction to establish a plane rectangular coordinate system;

vertically projecting the attractive forces of the three excitation coils on a reference surface, wherein the projection attractive forces are respectively F_A,F_B,F_C；F_A,F_B,F_CIs recorded as | F_A|、|F_B|、|F_C|；

From F_A、F_B、F_CMathematical expression of

A resultant force F can be obtained_A+F_B+F_CBy adjusting | F in the mathematical expression_A|、|F_B|、|F_CThe size of | can be combined to form the current float position P (x)_p,y_p) Resultant force F directed to equilibrium position O (0, 0)_P＝-β(x_pe_x+y_pe_y)；F_PThe float can be pulled back to the equilibrium position; wherein a is the side length of an equilateral triangle ABC, and beta is a real coefficient; e.g. of the type_x、e_yRespectively, x-axis and y-axis unit vectors.

Preferably, when | F_A|、|F_B|、|F_CI satisfy

When appropriate, F can be combined_P＝-β(x_pe_x+y_pe_y) Wherein the coefficient

F_PThe float can be moved from the current position P (x)_p,y_p) Pulling back to the equilibrium position.

When 3 excitation coils are used, an appropriate horizontal thrust can also be combined to move the float in the horizontal plane.

When 3 excitation coils are used, the target position value of the control is P₂(x₂,y₂) The method comprises the following steps:

the current magnitude and direction in the excitation coils A, B and C are changed to respectively generate proper electromagnetic force F_A、F_B、F_C，

By adjusting | F_A|、|F_B|、|F_CThe size of | can be combined to form the current floater position P₁(x₁,y₁) Pointing to a target position P₂(x₂,y₂) Resultant force F of_P＝γ[(x₂-x₁)e_x+(y₂-y₁)e_y]Where γ is a real coefficient, e_x、e_yRespectively representing x-axis and y-axis unit vectors; f_PCan make the floater move from P₁Point moving to P₂And (4) point.

Preferably, when | F_A|、|F_B|、|F_CSatisfy |

When appropriate, F can be combined_P＝γ[(x₂-x₁)_ex+(y₂-y₁)e_y]Wherein the coefficient

F_PCan make the floater move from P₁Point moving to P₂And (4) point.

For the structural design of the device, the excitation coil can adopt an excitation coil with a magnetic core: the excitation coil and the permanent magnet array are fixed on the upper surface of the chassis, and the excitation coil is symmetrically distributed by taking the center of the chassis as a central point Q; permanent magnets in the permanent magnet array are distributed around the outer side of the excitation coil and are annularly and symmetrically distributed by taking the central point Q as the center.

In another embodiment, the excitation coil may also be free of magnetic cores or permanent magnets: the excitation coil and the permanent magnet array can be detachably stacked up and down: the excitation coil is fixed on the coil base platform, and the coil base platform is placed on the upper surface of the permanent magnet array and can be detached and separated.

The floater is a cylindrical permanent magnet; the magnetic base comprises a chassis, 2 or 3 magnet exciting coils with magnetic cores, a permanent magnet array and a floater position monitoring unit;

the excitation coil and the permanent magnet array are fixed on the upper surface of the chassis, the center of the circle on the upper surface of the chassis is taken as a central point Q, the excitation coils are symmetrically distributed by taking the central point Q as the center, if the number of the excitation coils is 2, the midpoint of a line segment AB formed by connecting the central points A and B of the two excitation coils is taken as a point Q, a straight line AB is taken as an x axis, and the vertical bisector of the line segment AB is taken as a y axis; if the number of the exciting coils is 3, central points A, B and C of the three exciting coils form an equilateral triangle, the center of the equilateral triangle ABC is a point Q, a straight line QA is used as a y axis, and a straight line which passes through the point Q and is perpendicular to the straight line QA is used as an x axis.

The permanent magnet units in the permanent magnet array are distributed around the outer side of the magnet exciting coil, and the permanent magnet array is distributed in an annular symmetrical mode by taking the central point Q as the center.

The floater position monitoring unit is arranged at the central point Q, comprises two Hall sensors and is respectively used for detecting the current position values of the floater in the x direction and the y direction on the suspension plane in real time.

The float deviates from the equilibrium position due to external disturbance, etc., and the float position monitoring unit detects the current position value P (x)_p,y_p) The data are sent to the controller in real time, the controller compares the current position value with the set balance position value to generate a position deviation signal, and the magnitude and the direction of current in each magnet exciting coil are changed by combining the stress analysis and the calculation results of electromagnetic force of the magnet exciting coils and the floater, so that the resultant force of all the magnet exciting coils on the floater can pull the floater back to the balance position, and the suspension stability of the floater is effectively controlled.

Further, 3 magnet exciting coils are used, and appropriate horizontal thrust can be combined to enable the floater to move in the horizontal plane.

Has the beneficial effects that:

(1) The push-down magnetic repulsion type magnetic suspension device can realize stable suspension by using a smaller number of excitation coils, and the realization mode of 3 excitation coils breaks through the limitation that the excitation coils have to appear in pairs, thereby providing a brand new design method.

(2) The scheme of 2 magnet exciting coils can solve the problem of stable control of the floater at the central position, and the scheme of 3 magnet exciting coils can further solve the problem of control to any position.

(3) In a preferred embodiment, the excitation coil and the permanent magnet array are separated in space, so that the magnet can be independently disassembled and replaced, and the maintenance is easy.

(4) The excitation coil and the permanent magnet array are connected and supported by the coil base platform, and the coil base platform is directly installed on the upper surface of the permanent magnet array, so that the coil base platform is convenient to disassemble and separate, and is easier to maintain.

(5) Adopt coil base platform with excitation coil too high for excitation coil is closer to the float, is favorable to increasing the magnetic force between the two like this for under the condition that does not set up magnetic core or permanent magnet in excitation coil, also can guarantee the sufficient electromagnetic force between drive coil and the suspension magnet.

(6) The invention provides an advanced adjustment control method, which comprises the steps of dividing the distance between a final target value and an actual position into a plurality of target positions with equal intervals, sequentially comparing the actual position with the divided target positions to obtain error information, and performing small-step adjustment for multiple times based on the error to reach the target position. The lead adjustment method can effectively improve the control quality of the controlled object with larger time lag.

Drawings

FIG. 1 is a schematic view of the overall structure of a stator of the present invention including 2 field coils;

FIG. 2 is a top view of a stator of the present invention including 2 field coils;

FIG. 3 is a schematic view of the overall structure of the stator of the present invention including 3 field coils;

fig. 4 is a top view of a stator of the present invention including 3 field coils;

FIG. 5 is a schematic diagram of a control method;

FIG. 6 is a schematic illustration of the force applied by two solenoids to a float in a horizontal direction in accordance with one embodiment;

FIG. 7 is a schematic diagram showing the forces applied by two solenoids to a float in the horizontal direction in accordance with a second embodiment;

FIG. 8 is a schematic diagram showing the forces applied by two solenoids to a float in the horizontal direction in accordance with one embodiment;

fig. 9 is a schematic view of an excitation coil and a permanent magnet array stacked up and down according to four embodiments.

The sensor comprises a floater 1, a permanent magnet 2, a magnet exciting coil 3, a floater position monitoring unit x-direction Hall sensor 4, a floater position monitoring unit y-direction Hall sensor 5 and a coil base platform 6.

Detailed Description

The invention is described in detail below by way of example with reference to the accompanying drawings.

The first embodiment is as follows:

the magnetic levitation apparatus of the present embodiment employs 2 excitation coils, and realizes stable levitation of the push-down magnetic repulsion type magnetic levitation apparatus, that is, recovery from any point to a central point.

As shown in fig. 1-2, the magnetic levitation apparatus of the present embodiment includes a float 1, a magnetic base, and a controller (not shown in the drawings). The floater 1 is a cylindrical permanent magnet and is positioned on a suspension plane above the magnetic base, and the magnetic force of the floater and the magnetic base is mutually exclusive, so that the self gravity of the floater is balanced with the received repulsive force. The magnetic base comprises a chassis, two excitation coils 3 with magnetic cores, a permanent magnet array 2 and floater

position monitoring units

4 and 5.

The excitation coil 3 with the magnetic core and the permanent magnet array 2 are both fixed on the upper surface of the chassis, the center of the upper surface of the chassis is used as a center point Q, and the 2 excitation coils are symmetrically distributed by taking the center point Q as the center, namely the midpoint of a line segment AB formed by connecting the center points A and B of the 2 excitation coils is a point Q. The straight line AB is taken as the x-axis and the perpendicular bisector of the line segment AB is taken as the y-axis. The permanent magnet array 2 is composed of permanent magnets distributed around the outside of the magnetic exciting coil 3 with the magnetic core, and the permanent magnet array 2 is distributed in a ring shape symmetrically by taking a central point Q as the center.

The floater position monitoring unit is arranged at the central point Q and used for detecting the current position of the floater on the suspension plane in real time and obtaining a current position value. The float position monitoring unit includes an x-direction hall sensor 4 and a y-direction hall sensor 5.

The float deviates from the equilibrium position point O (0, 0) due to external disturbance and the like, and the float position monitoring unit detects the current position value P (x) of the float_p,y_p) Sending the data to the controller in real time, and the controller sending the current position value P (x)_p,y_p) Comparing with the set equilibrium position value O (0, 0) to generate position deviation signal, combining the force analysis and the electromagnetic force of the exciting coil and the floaterCalculating the result, and changing the current magnitude and direction in each excitation coil to make the resultant force F of all the excitation coils to the floater_PThe float can be pulled back to the equilibrium position, thereby effectively controlling the suspension stability of the float.

Concrete solution resultant force F_PThe process of (2) is as follows:

as shown in fig. 6, a plane rectangular coordinate system is established by taking a horizontal plane where the center point of the excitation coil is located as a reference plane, taking a connecting line of the center point a and the point B of the coils a and B as an x axis, and taking a perpendicular bisector of the line segment AB as a y axis; if the length | AB | = a of the line segment AB, the coordinates of two points A and B are respectively

Let the coordinate of the vertical projection point P of the float center on the reference surface be P (x)_p,y_p) The vertical projections of the floater on the reference surface by the attraction of the two excitation coils are respectively F_AAnd F_BThe resultant of the two attractive forces is F_P＝F_A+F_BAt a resultant force F_PThe float returns to the origin.

(Vector)

Therefore, the method comprises the following steps:

wherein | F_A|、|F_BRespectively denote F_A、F_BSize of (e)_x、e_yRespectively, x-axis and y-axis unit vectors.

Due to electromagnetic force F_A、F_BIs fixed in direction and adjustable in size, by adjusting F_A、F_BAccording to the parallelogram rule of vector operation and the force superposition principle, the magnitude of (x) can be combined to form the direction from the current floater position P (x)_p,y_p) Resultant force F directed to equilibrium position O (0, 0)_P＝-α(x_pe_x+y_pe_y) Where α is a real coefficient, e_x、e_yRespectively, x-axis and y-axis unit vectors. From F_A、F_BMathematical expression of

And

a resultant force F can be obtained_A+F_BBy adjusting | F in the mathematical expression_A|、|F_BSize of | can be combined to have a value of- μ (x)_pe_x+y_pe_y) Resultant force of the form F_P＝F_A+F_BThe float can be pulled back to the equilibrium position. μ is a real coefficient.

For example, when | F_A|、|F_BI satisfy

When appropriate, F can be combined_P＝-μ(x_pe_x+y_pe_y) Wherein the coefficients

F_PThe float can be pulled back to the equilibrium position. The controller changes the current magnitude and direction in the exciting coil A and B according to the position deviation signal to respectively generate proper electromagnetic force F_AAnd F_BResultant force F thereof_PThe float can be pulled back to the equilibrium position.

Example two:

the magnetic levitation device of the embodiment adopts 3 excitation coils to realize stable levitation of the push-down magnetic repulsion type magnetic levitation device, and the stable levitation is recovered from any point to a central point.

As shown in fig. 3 to 4, the magnetic levitation apparatus of the present embodiment includes a float 1, a magnetic base, and a controller. The floater 1 is a cylindrical permanent magnet and is positioned on a suspension plane above the magnetic base, and the magnetic force of the floater and the magnetic base is mutually exclusive, so that the self gravity of the floater is balanced with the received repulsive force. The magnetic base comprises a chassis, three excitation coils 3 with magnetic cores, a permanent magnet array 2 and floater

position monitoring units

4 and 5.

Take magnetic core excitation coil 3 and permanent magnet array 2 all to fix the upper surface on the chassis to chassis upper surface centre of a circle is central point Q, and 3 excitation coils use central point Q to present the symmetric distribution as the center, and 3 excitation coil's central point A, B, C constitute equilateral triangle promptly, and equilateral triangle ABC's center is the Q point. A straight line QA is taken as a y-axis, and a straight line passing through a Q point and perpendicular to the straight line QA is taken as an x-axis. The permanent magnet arrays are distributed around the outer side of the magnet exciting coil with the magnetic core, and the permanent magnet arrays are annularly and symmetrically distributed by taking the central point Q as the center.

The float deviates from the equilibrium position point O (0, 0) due to external disturbance and the like, and the float position monitoring unit detects the current position value P (x) of the float_p,y_p) The data is sent to the controller in real time, and the controller sends the current position value P (x)_p,y_p) Comparing with the set balance position value O (0, 0), generating position deviation signals, combining the results of stress analysis and calculation of electromagnetic force of the exciting coil and the floater, changing the current magnitude and direction in each exciting coil, and making the resultant force F of all exciting coils to the floater_PThe float can be pulled back to the equilibrium position, thereby effectively controlling the suspension stability of the float.

Solving in detail the resultant force F_PThe process of (2) is as follows:

as shown in fig. 7, a horizontal plane in which the center point of the exciting coil is located is used as a reference plane, the center points a, B, and C of the exciting coils a, B, and C form an equilateral triangle, the center O point of the equilateral triangle ABC is used as the origin of coordinates, and OA is used as the y-axis direction to establish a rectangular plane coordinate system. If the side length | AB | = a of the equilateral triangle ABC, the coordinates of the three points A, B and C are respectively

Let the coordinate of the vertical projection point P of the float center on the reference surface be P (x)_p,y_p) The vertical projection of the attraction force of the three electromagnetic coils on the reference surface of the floater is respectively F_A,F_B,F_CThe resultant of the three attractive forces is F_P＝F_A+F_B+F_CAt resultant force F_PThe float returns to the origin.

(Vector)

Therefore, the method comprises the following steps:

wherein | F_A|、|F_B|、|F_CRespectively represents F_A、F_B、F_CSize of (e)_x、e_yRespectively represent x-axis and y-axis unit vectors.

Due to electromagnetic force F_A、F_B、F_CIs fixed in direction and adjustable in size, by adjusting F_A、F_B、F_CAccording to the parallelogram rule of vector operation and the force superposition principle, the current float position P (x) in the direction can be combined_p,y_p) Resultant force F directed to equilibrium position O (0, 0)_P＝-β(x_pe_x+y_pe_y) Where β is a real coefficient, e_x、e_yRespectively, x-axis and y-axis unit vectors. From F_A、F_B、F_CMathematical expression of

A resultant force F can be obtained_A+F_B+F_CBy adjusting | F in the mathematical expression_A|、|F_B|、|F_CThe size of |, can be combined to have-beta (x)_pe_x+y_pe_y) The resultant of the forms.

For example, when | F_A|、|F_B|、|F_CI satisfy

F_PThe float can be pulled back to the equilibrium position. The controller changes the current magnitude and direction in the exciting coils A, B and C according to the position deviation signal to respectively generate proper electromagnetic force F_P＝F_A+F_B+F_CResultant force F thereof_PThe float can be pulled back to the equilibrium position.

Example three:

the magnetic suspension device of the present embodiment has the same structure as the embodiment. The purpose of this embodiment is to control the float from P₁P with point moved to non-zero point₂And (4) point.

The magnetic suspension device comprises a floater which is a cylindrical permanent magnet and a magnetic base, wherein the floater is positioned on a suspension plane above the magnetic base, and the magnetic force of the floater and the magnetic base is mutually exclusive, so that the gravity of the floater is balanced with the received repulsive force.

The magnetic base comprises a chassis, 3 magnet exciting coils with magnetic cores, a permanent magnet array, a floater position monitoring unit and a controller.

The excitation coil with the magnetic core and the permanent magnet array are both fixed on the upper surface of the chassis, the center of the upper surface of the chassis is taken as a central point Q, the 3 excitation coils are symmetrically distributed by taking the central point Q as the center, namely, the central points A, B and C of the 3 excitation coils form an equilateral triangle, and the center of the equilateral triangle ABC is taken as a Q point. The permanent magnet arrays are distributed around the outer side of the excitation coil with the magnetic core, and the permanent magnet arrays are distributed in an annular symmetrical mode by taking the central point Q as the center.

The floater position monitoring unit is arranged at the central point Q and used for detecting the current position of the floater on the suspension plane in real time and obtaining a current position value.

The float position monitoring unit detects the current position value P of the float₁(x₁,y₁) The data is sent to the controller in real time, and the controller sends the current position value P₁(x₁,y₁) And the set required movement to the target position value P₂(x₂,y₂) Comparing to generate position deviation signals, combining the results of stress analysis and calculation of electromagnetic force of the exciting coils and the floater to change the current magnitude and direction in each exciting coil so as to enable the resultant force F of all the exciting coils to the floater_PThe float can be moved to a target position.

Concrete solution resultant force F_PThe process of (2) is as follows:

as shown in fig. 8, a horizontal plane where the center point of the excitation coil is located is used as a reference plane, the center points a, B, and C of the excitation coils a, B, and C form an equilateral triangle, the center point O of the equilateral triangle ABC is used as a coordinate origin, and OA is used as a y-axis direction to establish a rectangular plane coordinate system. Setting the side length AB | = a of the equilateral triangle ABC, and the vertical projection point P of the center of the circle of the initial position of the floater on the reference surface₁Has the coordinate of P₁(x₁,y₁) Moving the floater to a target position, wherein the center of the floater is positioned at the vertical projection point P on the reference surface₂Has the coordinate of P₂(x₂,y₂). The vertical projection of the attraction force of the three electromagnetic coils on the reference surface of the floater is respectively F_A,F_B,F_CThree attractive forcesResultant force of F_P＝F_A+F_B+F_C

The coordinates of three points A, B and C are respectively

(Vector)

Therefore, the method comprises the following steps:

wherein | F_A|、|F_B|、|F_CRespectively denote F_A、F_B、F_CSize of (e)_x、e_yRespectively, x-axis and y-axis unit vectors.

Due to electromagnetic force F_A、F_B、F_CIs fixed in direction and adjustable in size, by adjusting F_A、F_B、F_CAccording to the parallelogram rule of vector operation and the force superposition principle, the magnitude of the force can be combined to form the direction from the current floater position P₁(x₁,y₁) Pointing to a target position P₂(x₂,y₂) Resultant force F of_P＝γ[(x₂-x₁)e_x+(y₂-y₁)e_y]Where γ is a real coefficient, e_x、e_yRespectively represent x-axis and y-axis unit vectors. From F_A、F_B、F_CMathematical expression of

A resultant force F can be obtained_A+F_B+F_CBy adjusting | F in the mathematical expression_A|、|F_B|、|F_CThe size of |, can be combined to have γ [ (x)₂-x₁)e_x+(y₂-y₁)e_y]The resultant of the forms.

For example, when | F_A|、|F_B|、|F_CI satisfy

When appropriate, F can be combined_P＝γ[(x₂-x₁)e_x+(y₂-y₁)e_y]Wherein the coefficients

F_PCan make the floater move from P₁Point moving to P₂And (4) point. The controller changes the current magnitude and direction in the exciting coils A, B and C according to the position deviation signal to respectively generate proper electromagnetic force F_A,F_B,F_CResultant force F thereof_P＝F_A+F_B+F_CCan make the floater move from P₁Point moves to P₂And (4) point.

When the floater is required to be stabilized at P₂When the float is in contact with the ground, the position of the float deviates from P due to disturbance₂At this point, the sensor will detect the actual position of the float, passing through the target position P of stable levitation₂Obtaining error information by point comparison, and further obtaining the magnitude and direction of each excitation coil current according to the stress analysis calculation result and through a control method of advanced adjustment so as to adjust | F_A|、|F_B|、|F_CL. making F_P＝F_A+F_B+F_CCan adjust the float back to the target stable position P₂And (4) point.

Example four

In the first to third embodiments, the exciting coil 3 is an exciting coil with a magnetic core. The excitation coil 3 and the permanent magnet array 2 are both fixed on the upper surface of the chassis. In the present embodiment, the exciting coil 3 is an exciting coil that does not include a magnetic core or a permanent magnet. As shown in fig. 9, the excitation coil 3 and the permanent magnet array 2 are detachably stacked one on another: the magnet exciting coil 3 is fixed on the coil base platform 6, and the coil base platform 6 is placed on the upper surface of the permanent magnet array 2 and can be detached and separated.

In this embodiment, the excitation coil 3 and the permanent magnet array 2 are detachably stacked up and down, so that the driving unit is closer to the floating magnet, which is beneficial to increase the magnetic force between the two. Through the series of arrangement, under the condition that a magnetic core or a permanent magnet is not arranged in the driving coil, enough electromagnetic force between the driving coil and the suspension magnet can be ensured. And, adopt the structure with excitation coil setting at coil base platform, coil base platform direct mount is on magnetic stator upper surface, is convenient for dismantle the separation to easy to maintain more.

In any of the first to fourth embodiments, the control method shown in fig. 5 may be adopted. As shown in fig. 5, after the displacement sensor obtains the position of the float, the position is subjected to analog-to-digital conversion and compared with a target position, the difference between the two is 0, the PD operation is performed, the output result generates PWM, and after optical coupling isolation, a driving signal is generated and output to the electromagnetic coil. The control process can add advanced control: the displacement of the floater is realized by a small-spacing stepping method, the actual position of the floater is detected in real time through a sensor, the distance between the final target value and the actual position of the floater is divided into a plurality of target positions with equal spacing, the actual positions and the divided target positions are compared to obtain error information, the current magnitude and direction of each magnet exciting coil are obtained according to a stress analysis calculation result and a control method of advanced adjustment, electromagnetic force facing to the target positions is generated, and the floater is pushed to move towards the target positions. The advanced adjustment control method divides the distance between the final target value and the actual position into a plurality of target positions with equal intervals, compares the actual position with the divided target positions in sequence to obtain error information, and performs small-step adjustment for a plurality of times based on the error to reach the target position. The lead adjustment method can effectively improve the control quality of the controlled object with larger time lag.

The above embodiments only describe the design principle of the present invention, and the shapes and names of the components in the description may be different without limitation. Therefore, a person skilled in the art of the present invention can modify or substitute the technical solutions described in the foregoing embodiments; such modifications and substitutions do not depart from the spirit and scope of the present invention.

Claims

1. A magnetic levitation apparatus, comprising: the device comprises a floater (1), a magnetic base and a controller; the floater is a cylindrical permanent magnet; the magnetic base comprises a chassis, 2 or 3 magnet exciting coils (3), a permanent magnet array (2) and floater position monitoring units (4, 5);

the chassis is a mounting surface of the excitation coil (3) and the permanent magnet array (2); all the excitation coils (3) and the permanent magnet array (2) are symmetrically distributed by taking the center of the circle of the chassis as a central point Q; the loop line formed by the centers of all the permanent magnets in the permanent magnet array (2) is positioned outside the loop line formed by the centers of all the magnet exciting coils (3); the floater position monitoring unit is arranged at the central point Q and is used for detecting the current position P (x) of the floater on the suspension plane in real time_p,y_p) Transmitting to the controller;

the controller compares the current position value P (x)_p,y_p) Comparing with the target position value to generate a position deviation signal, and combining the calculation results of the stress analysis and the electromagnetic force of the exciting coil and the floater to change the current magnitude and direction in all the exciting coils so as to ensure that the resultant force F of all the exciting coils to the floater_PThe float can be pulled to a target position value.

2. Magnetic levitation apparatus according to claim 1, wherein the number of exciting coils (3) is 2, and when the target position value of the control is the equilibrium position point O (0, 0):

establishing a plane rectangular coordinate system by taking a horizontal plane where the center points of the excitation coils are located as a reference plane, taking a connecting line of the center points A and B of the two excitation coils A and B as an x axis and taking a vertical bisector of a line segment AB as a y axis; vertically projecting the attractive forces of two excitation coils on a reference plane, wherein the projected attractive forces are respectively F_AAnd F_B；F_AAnd F_BIs marked as | F_A|、|F_B|；

From F_A、F_BMathematical expression of

And

a resultant force F can be obtained_A+F_BBy adjusting | F in the mathematical expression_A|、|F_BThe size of | can be combined to form the current float position P (x)_p,y_p) Resultant force F directed to equilibrium position O (0, 0)_P＝-μ(x_pe_x+y_pe_y)，F_PThe float can be pulled back to the equilibrium position;

wherein a is the length of the line segment AB and mu is a real coefficient; e.g. of the type_x、e_yRespectively represent x-axis and y-axis unit vectors.

3. Magnetic levitation apparatus as defined in claim 1, characterised in that when | F_A|、|F_BI satisfy

In the meantime, an appropriate resultant force F can be combined_P＝-μ(x_pe_x+y_pe_y) Wherein the coefficient

4. Magnetic levitation apparatus according to claim 1, wherein the number of the exciting coils (3) is 3, and when the target position value of the control is the equilibrium position point O (0, 0):

From F_A、F_B、F_CMathematical expression of

A resultant force F can be obtained_A+F_B+F_CBy adjusting | F in the mathematical expression_A|、|F_B|、|F_CThe size of | can be combined to form the current float position P (x)_p,y_p) Resultant force F directed to equilibrium position O (0, 0)_P＝-β(x_pe_x+y_pe_y)；F_PThe float can be pulled back to the equilibrium position; wherein a is the side length of an equilateral triangle ABC, and beta is a real coefficient; e.g. of a cylinder_x、e_yRespectively, x-axis and y-axis unit vectors.

5. Magnetic levitation apparatus as defined in claim 4, characterised in that when | F |, is_A|、|F_B|、|F_CSatisfy |

Then appropriate F can be combined_P＝-β(x_pe_x+y_pe_y) Wherein the coefficient

6. A magnetic levitation apparatus as claimed in claim 4, wherein 3 exciting coils are used, combined to give a suitable horizontal thrust to move the float in the horizontal plane.

7. Magnetic levitation apparatus as claimed in claim 6, wherein the controlled target position value is P₂(x₂,y₂) The method comprises the following steps:

the current magnitude and direction in the exciting coils A, B and C are changed to respectively generate proper electromagnetic force F_A、F_B、F_C，

By adjusting | F_A|、|F_B|、|F_CThe magnitude of | can be combined from the current float position P₁(x₁,y₁) Pointing to a target position P₂(x₂,y₂) Resultant force F of_P＝γ[(x₂-x₁)e_x+(y₂-y₁)e_y]Where γ is a real coefficient, e_x、e_yRespectively representing x-axis and y-axis unit vectors; f_PCan make the floater move from P₁Point moving to P₂And (4) point.

8. Magnetic levitation apparatus as claimed in claim 7, wherein if F is_A|、|F_B|、|F_CSatisfy |

Then appropriate F can be combined_P＝γ[(x₂-x₁)e_x+(y₂-y₁)e_y]Wherein the coefficients

F_PCan make the floater move from P₁Point moves to P₂And (4) point.

9. Magnetic levitation apparatus according to any of claims 1-8, characterised in that the exciter coil (3) is a magnetic core exciter coil:

the excitation coil (3) and the permanent magnet array (2) are fixed on the upper surface of the chassis, and the excitation coil is symmetrically distributed by taking the center of the chassis as a central point Q; permanent magnets in the permanent magnet array (2) are distributed around the outer side of the excitation coil (3) and are circularly and symmetrically distributed by taking the central point Q as the center.

10. Magnetic levitation apparatus according to any of claims 1-8, characterised in that the excitation coil (3) does not contain magnetic cores or permanent magnets:

the excitation coil (3) and the permanent magnet array (2) can be stacked up and down in a detachable mode: the magnet exciting coil (3) is fixed on the coil base platform (6), and the coil base platform (6) is placed on the upper surface of the permanent magnet array (2) and can be detached and separated.