A magnetic levitation device

Abstract

The invention discloses a magnetic suspension device, comprising a float, a magnetic base and a controller; the magnetic base comprises a chassis, two or three excitation coils, a permanent magnet array and a float position monitoring unit; the chassis is a mounting surface for the excitation coil and the permanent magnet array; the float position monitoring unit is arranged at the center point of the chassis for real-time detection of the current position of the float on the suspension plane and transmits it to the controller; the controller compares the current position value with the target position value, generates a position deviation signal, combines the force analysis and the calculation result of the electromagnetic force between the excitation coil and the float, changes the current magnitude and direction in all the excitation coils, so that the resultant force F of all the excitation coils on the float is P The float can be pulled to the target position value. The present invention breaks through the limitation that a set of two coils in pairs can only realize the control of the degree of freedom in a certain direction, can save space and materials, and is conducive to the miniaturization of the magnetic suspension device.

Description

Technical Field

[0001] The invention relates to a magnetic suspension device, in particular to a magnetic repulsion type magnetic suspension device. Background Art

[0002] The basic principle of the existing push-down magnetic repulsion type magnetic suspension device is that the float is located at the center of the upper part, and an excitation coil and an annular magnet are installed below. The annular magnet generates a repulsive force that is balanced with the gravity of the float. The electromagnetic force generated by the excitation coil can control the stability of the float, so that the float can be stably suspended at the center of the annular magnet. The number of excitation coils is generally 4 (invention patents CN1819436A, CN110677075A) or more (invention patent US20070170798A1). The basic principle is to control the horizontal x-direction degree of freedom of the float with a pair of 2 coils, and to control the horizontal y-direction degree of freedom of the float with another pair of 2 coils. Therefore, the number of excitation coils in the existing push-down magnetic repulsion type magnetic suspension device is at least 4, and they appear in pairs.

[0003] As the demand for miniaturization of magnetic levitation devices increases, how to reduce the size of the device has become a research direction. However, the solution of miniaturization by reducing the excitation coil has not been well solved. Summary of the invention

[0004] In view of this, the present invention provides a solution for achieving stable suspension of a push-down magnetic repulsion type magnetic levitation device by using a smaller number of excitation coils. The solution uses 2 or 3 excitation coils to achieve suspension, breaking through the limitation of using a pair of 2 coils to only control the degree of freedom in a certain direction. It can save space and materials, help to miniaturize the magnetic levitation device, and is conducive to the expansion of the application scenarios of the magnetic levitation device.

[0005] In order to solve the above technical problems, the present invention is implemented as follows.

[0006] A magnetic suspension device comprises: a float, a magnetic base and a controller; the float is a cylindrical permanent magnet; the magnetic base comprises a chassis, 2 or 3 excitation coils, a permanent magnet array and a float position monitoring unit;

[0007] The chassis is the mounting surface of the excitation coil and the permanent magnet array; all the excitation coils and the permanent magnet array are symmetrically distributed with the center of the chassis as the center point Q; the loop formed by the centers of the permanent magnets in the permanent magnet array is located outside the loop formed by the centers of the excitation coils; the float position monitoring unit is located at the center point Q, which is used to detect the current position P (x p ,y p ), passed to the controller;

[0008] The controller sets the current position value P(xp ,y p ) is compared with the target position value to generate a position deviation signal. Combined with the force analysis and the calculation results of the electromagnetic force between the excitation coil and the float, the current magnitude and direction in all the excitation coils are changed so that the resultant force F of all the excitation coils on the float P Capable of pulling the float to the target position value.

[0009] Among them, there are 2 excitation coils, and the target position value of the control is the equilibrium position point O(0,0):

[0010] Take the horizontal plane where the center point of the excitation coil is located as the reference plane, take the line connecting the center points A and B of the two excitation coils A and B as the x-axis, and the perpendicular bisector of line segment AB as the y-axis to establish a plane rectangular coordinate system; project the attraction of the two excitation coils vertically onto the reference plane, and the projected attraction is F A and F B ; F A and F B The size of |F A |、|F B |;

[0011] By F A 、F B Mathematical expression of and The resultant force F can be obtained A +F B By adjusting |F in the mathematical expression A |、|F B | can be combined to form the current float position P(x p ,y p ) The resultant force F pointing to the equilibrium position O(0,0) P = -μ(x p e x +y p e y ), F P The float can be pulled back to the equilibrium position; where a is the length of line segment AB, μ is a real coefficient; e x 、e y Represent the x-axis and y-axis unit vectors respectively.

[0012] Preferably, when |F A |、|F B |Satisfaction When the appropriate resultant force F P = -μ(x p e x +y p e y ), where the coefficient F P The float can be moved from the current position P(x p ,y p ) back to the equilibrium position.

[0013] Among them, there are three excitation coils (3), and the target position value of the control is the equilibrium position point O(0,0):

[0014] Take the horizontal plane where the center point of the excitation coil is located as the reference plane, the center points A, B, C of the three excitation coils A, B, C form an equilateral triangle, take the center point O of the equilateral triangle ABC as the coordinate origin, and establish a plane rectangular coordinate system with OA as the y-axis direction;

[0015] The attractive forces of the three excitation coils are projected vertically onto the reference plane. The projected attractive forces are F A ,F B ,F C ; F A ,F B ,F C The size of |F A |、|F B |、|F C |;

[0016] By F A 、F B 、F C Mathematical expression of The resultant force F can be obtained A +F B +F C By adjusting |F in the mathematical expression A |、|F B |、|F C | can be combined to form the current float position P(x p ,y p ) The resultant force F pointing to the equilibrium position O(0,0) P = -β(x p e x +y p e y );F P The float can be pulled back to the equilibrium position; where a is the side length of the equilateral triangle ABC, β is a real coefficient; e x 、e y Represent the x-axis and y-axis unit vectors respectively.

[0017] Preferably, when |F A |、|F B |、|F C |Satisfaction When the appropriate F P = -β(x p e x +y p e y ), where the coefficient F P The float can be moved from the current position P(x p ,y p ) back to the equilibrium position.

[0018] When three excitation coils are used, appropriate horizontal thrust can also be combined to move the float in the horizontal plane.

[0019] When using 3 excitation coils, the target position value of the control is P 2 (x 2 ,y 2 )hour:

[0020] Change the magnitude and direction of the current in the excitation coils A, B, and C to generate appropriate electromagnetic forces F respectively. A 、F B 、F C ,

[0021] By adjusting |F A |、|F B |、|F C | can be combined to form the current float position P 1 (x 1 ,y 1 ) points to the target position P 2 (x 2 ,y 2 ) P =γ[(x 2 -x 1 ) x +(y 2 -y 1 ) y ], where γ is a real coefficient, e x 、e y Respectively represent the x-axis and y-axis unit vectors; F P The float can be made by P 1 Move point to P 2 point.

[0022] Preferably, when |F A |、|F B |、|F C |Satisfaction When the appropriate F P =γ[(x2 -x 1 ) e x+(y 2 -y 1 ) y ], where the coefficient F P The float can be made by P 1 Move point to P 2 point.

[0023] 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 both fixed on the upper surface of the chassis, and the excitation coil is symmetrically distributed with the center of the chassis as the center point Q; the permanent magnets in the permanent magnet array are distributed around the outside of the excitation coil, and are annularly symmetrically distributed with the center point Q as the center.

[0024] In another design, the excitation coil may also not contain a magnetic core or a permanent magnet: 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 disassembled and separated.

[0025] The float is a cylindrical permanent magnet; the magnetic base includes a chassis, 2 or 3 excitation coils with magnetic cores, a permanent magnet array and a float position monitoring unit;

[0026] The excitation coil and the permanent magnet array are both fixed on the upper surface of the chassis, with the center of the circle on the upper surface of the chassis as the center point Q, and the excitation coils are symmetrically distributed around the center point Q. If there are two excitation coils, the midpoint of the line segment AB formed by connecting the center points A and B of the two excitation coils is point Q, and the straight line AB is used as the x-axis, and the perpendicular bisector of the line segment AB is used as the y-axis; if there are three excitation coils, the center points A, B, and C of the three excitation coils form an equilateral triangle, and the center of the equilateral triangle ABC is point Q, the straight line QA is used as the y-axis, and the straight line passing through point Q and perpendicular to the straight line QA is used as the x-axis.

[0027] The permanent magnet units in the permanent magnet array are distributed around the outside of the excitation coil, and the permanent magnet array is distributed in a ring-shaped symmetrical manner with the center point Q as the center.

[0028] The float position monitoring unit is arranged at the center point Q, and comprises two Hall sensors, which are used to detect the current position values ​​of the float in the x direction and the y direction on the suspension plane in real time.

[0029] Due to external disturbances and other reasons, the float will deviate from the equilibrium position. The float position monitoring unit detects the current position value P(x p ,y p), and sends the data to the controller in real time. The controller compares the current position value with the set equilibrium position value, generates a position deviation signal, and combines the force analysis and the calculation results of the electromagnetic force between the excitation coil and the float to change the current size and direction in each excitation coil, so that the combined force of all the excitation coils on the float can pull the float back to the equilibrium position, thereby effectively controlling the suspension stability of the float.

[0030] Furthermore, by using three excitation coils, an appropriate horizontal thrust can be combined to move the float in the horizontal plane.

[0031] Beneficial effects:

[0032] (1) The present invention can achieve stable suspension of the push-down magnetic repulsion type magnetic suspension device using a smaller number of excitation coils, and the implementation method of three excitation coils breaks through the limitation that the excitation coils must appear in pairs, providing a new design method.

[0033] (2) The solution of two excitation coils of the present invention can solve the problem of stable control of the float at the center position, and the solution of three excitation coils can further solve the problem of control at any position.

[0034] (3) In a preferred embodiment, the excitation coil and the permanent magnet array are separated in space and can be independently disassembled and replaced for easy maintenance.

[0035] (4) The excitation coil and the permanent magnet array are connected and supported by a coil base platform. The coil base platform is directly installed on the upper surface of the permanent magnet array, which is convenient for disassembly and separation, making it easier to maintain.

[0036] (5) The coil base platform is used to raise the excitation coil so that the excitation coil is closer to the float, which is beneficial to increase the magnetic force between the two. Even if a magnetic core or permanent magnet is not set in the excitation coil, sufficient electromagnetic force can be guaranteed between the driving coil and the suspension magnet.

[0037] (6) The present invention provides a method for advanced control, which divides the distance between the final target value and the actual position into several equally spaced target positions, compares the actual position with the divided target positions in turn to obtain error information, and performs multiple small step adjustments based on the error to reach the target position. The advanced control method can effectively improve the control quality of the controlled object with a large time lag. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The schematic diagram of the overall structure of the stator of the present invention includes two excitation coils;

[0039] Figure 2 A top view of a stator including two excitation coils according to the present invention;

[0040] Figure 3 The schematic diagram of the overall structure of the stator of the present invention includes three excitation coils;

[0041] Figure 4 A top view of a stator including three excitation coils according to the present invention;

[0042] Figure 5 It is a schematic diagram of the control method;

[0043] Figure 6 This is a schematic diagram of the force exerted by two electromagnetic coils on the float in the horizontal direction in Example 1;

[0044] Figure 7 This is a schematic diagram of the force exerted by two electromagnetic coils on the float in the horizontal direction in Example 2;

[0045] Figure 8 This is a schematic diagram of the force exerted by two electromagnetic coils on the float in the horizontal direction in Example 3;

[0046] Fig. 9 Schematic diagram of the excitation coil and permanent magnet array stacked up and down in Example 4.

[0047] Among them, 1-float, 2-permanent magnet, 3-excitation coil, 4-x-direction Hall sensor of float position monitoring unit, 5-y-direction Hall sensor of float position monitoring unit, 6-coil base platform. DETAILED DESCRIPTION

[0048] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0049] Embodiment 1:

[0050] The magnetic suspension device of this embodiment uses two excitation coils to achieve stable suspension of the push-down magnetic repulsion type magnetic suspension device, that is, to restore from any point to the center point.

[0051] like Figure 1-2 As shown, the magnetic suspension device of this embodiment includes a float 1, a magnetic base and a controller (not shown in the figure). The float 1 is a cylindrical permanent magnet, located on the suspension plane above the magnetic base. The float and the magnetic base repel each other magnetically, so that the float's own gravity is balanced with the repulsive force. The magnetic base includes a chassis, two excitation coils 3 with magnetic cores, a permanent magnet array 2 and a float position monitoring unit 4, 5.

[0052] The magnetic core excitation coil 3 and the permanent magnet array 2 are both fixed on the upper surface of the chassis, with the center of the circle on the upper surface of the chassis as the center point Q, and the two excitation coils are symmetrically distributed around the center point Q, that is, the midpoint of the line segment AB formed by connecting the center points A and B of the two excitation coils is point Q. The straight line AB is used as the x-axis and the perpendicular bisector of the line segment AB is used as the y-axis. The constituent units in the permanent magnet array 2, that is, the permanent magnets, are distributed around the outer side of the magnetic core excitation coil 3, and the permanent magnet array 2 is annularly symmetrically distributed around the center point Q.

[0053] The float position monitoring unit is arranged at the center point Q, and is used to detect the current position of the float on the suspension plane in real time and obtain the current position value. The float position monitoring unit includes an x-direction Hall sensor 4 and a y-direction Hall sensor 5 .

[0054] Due to external disturbances and other reasons, the float will deviate from the equilibrium position O(0,0). The float position monitoring unit detects the current position value P(x p ,y p ), sends the data to the controller in real time, and the controller converts the current position value P(x p ,y p ) is compared with the set equilibrium position value O(0,0) to generate a position deviation signal. Combined with the force analysis and the calculation results of the electromagnetic force between the excitation coil and the float, the current size and direction in each excitation coil are changed so that the combined force F of all the excitation coils on the float is P The float can be pulled back to the equilibrium position, thereby effectively controlling the suspension stability of the float.

[0055] Solve the resultant force F P The process is as follows:

[0056] like Figure 6 As shown in the figure, the horizontal plane where the center point of the excitation coil is located is used as the reference plane, the line connecting the center points A and B of coils A and B is used as the x-axis, and the perpendicular bisector of line segment AB is used as the y-axis to establish a plane rectangular coordinate system; if the length of line segment AB |AB| = a, then the coordinates of the two points A and B are

[0057] Let the coordinates of the vertical projection point P of the float center on the reference plane be P(x p ,y p ), the vertical projections of the float on the reference plane under the attraction of the two excitation coils are F A and F B , the combined force of the two attractive forces is F P =F A +F B , in the resultant force F P Under the action of, the float returns to the origin.

[0058] vector Therefore, there are:

[0059]

[0060] where |F A |、|F B | respectively represent F A 、F B The size of e x 、e y Represent the x-axis and y-axis unit vectors respectively.

[0061] Due to the electromagnetic force F A 、F B The direction is fixed and the size is adjustable. A 、F B According to the parallelogram law of vector operations and the principle of superposition of forces, the direction can be combined to obtain the direction of the current float position P(x p ,y p ) The resultant force F pointing to the equilibrium position O(0,0) P = -α(x p e x +y p e y ), where α is a real coefficient, e x 、e y Represent the x-axis and y-axis unit vectors respectively. A 、F B Mathematical expression of and The resultant force F can be obtained A +F B By adjusting |F in the mathematical expression A |、|F B | can be combined to form -μ(x p e x +y p e y ) form, so that F P =F A +F B The float can be pulled back to the equilibrium position. μ is a real coefficient.

[0062] For example, when |F A |、|F B |Satisfaction When the appropriate F P = -μ(x p e x +y p e y ), where the coefficient F P The float can be pulled back to the equilibrium position. The controller changes the current size and direction in the excitation coils A and B according to the position deviation signal to generate appropriate electromagnetic force F A and F B , the resultant force F P The float can be pulled back to the equilibrium position.

[0063] Embodiment 2:

[0064] The magnetic suspension device of this embodiment uses three excitation coils to achieve stable suspension of the push-down magnetic repulsion type magnetic suspension device and restore it to the center point from any point.

[0065] like Figure 3-4 As shown, the magnetic suspension device of this embodiment includes a float 1, a magnetic base and a controller. The float 1 is a cylindrical permanent magnet, located on the suspension plane above the magnetic base. The float and the magnetic base repel each other magnetically, so that the float's own gravity is balanced with the repulsive force. The magnetic base includes a chassis, three magnetic core excitation coils 3, a permanent magnet array 2 and a float position monitoring unit 4, 5.

[0066] The magnetic core excitation coil 3 and the permanent magnet array 2 are both fixed on the upper surface of the chassis. The center of the circle on the upper surface of the chassis is the center point Q. The three excitation coils are symmetrically distributed around the center point Q, that is, the center points A, B, and C of the three excitation coils form an equilateral triangle, and the center of the equilateral triangle ABC is point Q. The straight line QA is used as the y-axis, and the straight line passing through point Q and perpendicular to the straight line QA is used as the x-axis. The permanent magnet array is distributed around the outer side of the magnetic core excitation coil, and the permanent magnet array is annularly symmetrically distributed around the center point Q.

[0067] The float position monitoring unit is arranged at the center point Q, and is used to detect the current position of the float on the suspension plane in real time and obtain the current position value. The float position monitoring unit includes an x-direction Hall sensor 4 and a y-direction Hall sensor 5 .

[0068] Due to external disturbances and other reasons, the float will deviate from the equilibrium position O(0,0). The float position monitoring unit detects the current position value P(x p ,y p ), sends the data to the controller in real time, and the controller converts the current position value P(x p ,y p ) is compared with the set equilibrium position value O(0,0) to generate a position deviation signal. Combined with the force analysis and the calculation results of the electromagnetic force between the excitation coil and the float, the current size and direction in each excitation coil are changed so that the combined force F of all the excitation coils on the float is P The float can be pulled back to the equilibrium position, thereby effectively controlling the suspension stability of the float.

[0069] Solve the resultant force F P The process is as follows:

[0070] like Figure 7 As shown, the horizontal plane where the center point of the excitation coil is located is used as the 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 the origin of the coordinates, and OA is used as the y-axis direction to establish a plane rectangular coordinate system. Assuming that the side length of the equilateral triangle ABC |AB| = a, the coordinates of the three points A, B, and C are respectively

[0071] Let the coordinates of the vertical projection point P of the float center on the reference plane be P(x p ,y p ), the vertical projections of the float on the reference plane under the attraction of the three electromagnetic coils are F A ,F B ,F C , the combined force of the three attractions is F P =F A +F B +F C , in the resultant force F P Under the action of, the float returns to the origin.

[0072] vector Therefore, there are:

[0073]

[0074] where |F A |、|F B |、|F C | respectively represent F A 、F B 、F C The size of e x 、e y Represent the x-axis and y-axis unit vectors respectively.

[0075] Due to the electromagnetic force F A 、F B 、F C The direction is fixed and the size is adjustable. A 、F B 、F C According to the parallelogram law of vector operations and the principle of superposition of forces, the direction can be combined to obtain the direction of the current float position P(x p ,y p ) The resultant force F pointing to the equilibrium position O(0,0) P = -β(x p ex +y p e y ), where β is a real coefficient, e x 、e y Represent the x-axis and y-axis unit vectors respectively. A 、F B 、F C Mathematical expression of The resultant force F can be obtained A +F B +F C By adjusting |F in the mathematical expression A |、|F B |、|F C | can be combined to form a -β(x p e x +y p e y ) forms of combined force.

[0076] For example, when |F A |、|F B |、|F C |Satisfaction When the appropriate F P = -β(x p e x +y p e y ), where the coefficient F P The float can be pulled back to the equilibrium position. The controller changes the current size and direction in the excitation coils A, B, and C according to the position deviation signal to generate appropriate electromagnetic forces F P =F A +F B +F C , the resultant force F P The float can be pulled back to the equilibrium position.

[0077] Embodiment three:

[0078] The structure of the magnetic suspension device of this embodiment is the same as that of the second embodiment. 1 Point moves to non-zero point P 2 point.

[0079] The magnetic suspension device of this embodiment includes a float, which is a cylindrical permanent magnet. The magnetic suspension device also includes a magnetic base. The float is located on a suspension plane above the magnetic base. The float and the magnetic base repel each other magnetically, so that the float's own gravity is balanced with the repulsive force it receives.

[0080] The magnetic base includes a chassis, three excitation coils with magnetic cores, a permanent magnet array, a float position monitoring unit and a controller.

[0081] The magnetic core excitation coil and the permanent magnet array are fixed on the upper surface of the chassis, with the center of the circle on the upper surface of the chassis as the center point Q, and the three excitation coils are symmetrically distributed around the center point Q, that is, the center points A, B, and C of the three excitation coils form an equilateral triangle, and the center of the equilateral triangle ABC is point Q. The permanent magnet array is distributed around the outer side of the magnetic core excitation coil, and the permanent magnet array is annularly symmetrically distributed around the center point Q.

[0082] The float position monitoring unit is arranged at the center point Q, and is used to detect the current position of the float on the suspension plane in real time and obtain the current position value.

[0083] The float position monitoring unit detects the current position value P of the float. 1 (x 1 ,y 1 ), the data is sent to the controller in real time, and the controller converts the current position value P 1 (x 1 ,y 1 ) and the target position value P 2 (x 2 ,y 2 ) to generate a position deviation signal, and combine the force analysis and the calculation results of the electromagnetic force between the excitation coil and the float to change the current size and direction of each excitation coil so that the combined force F of all the excitation coils on the float P Able to move the float to a target position.

[0084] Solve the resultant force F P The process is as follows:

[0085] like Figure 8 As shown, the horizontal plane where the center point of the excitation coil is located is used as the 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 the origin of the coordinates, and OA is used as the y-axis direction to establish a plane rectangular coordinate system. Assume that the side length of the equilateral triangle ABC |AB| = a, and the vertical projection point P of the center point of the float's initial position on the reference plane 1 The coordinates of 1 (x 1 ,y 1 ), move the float to the target position, the vertical projection point P of the float center on the reference plane 2 The coordinates of 2 (x 2 ,y 2 ). The vertical projections of the float on the reference plane under the attraction of the three electromagnetic coils are FA ,F B ,F C , the combined force of the three attractions is F P =F A +F B +F C

[0086] The coordinates of the three points A, B, and C are vector Therefore, there are:

[0087]

[0088] where |F A |、|F B |、|F C | respectively represent F A 、F B 、F C The size of e x 、e y Represent the x-axis and y-axis unit vectors respectively.

[0089] Due to the electromagnetic force F A 、F B 、F C The direction is fixed and the size is adjustable. A 、F B 、F C The size of the float can be combined according to the parallelogram law of vector operations and the superposition principle of forces to obtain the direction of the float. 1 (x 1 ,y 1 ) points to the target position P 2 (x 2 ,y 2 ) P =γ[(x 2 -x 1 ) x +(y 2 -y 1 ) y ], where γ is a real coefficient, e x 、e y Represent the x-axis and y-axis unit vectors respectively. A 、F B 、F C Mathematical expression of The resultant force F can be obtained A +F B +F C By adjusting |F in the mathematical expression A |、|FB |、|F C | can be combined to form a 2 -x 1 ) x +(y 2 -y 1 ) y ]The combined force of the form.

[0090] For example, when |F A |、|F B |、|F C |Satisfaction When the appropriate F P =γ[(x 2 -x 1 ) x +(y 2 -y 1 ) y ], where the coefficient F P The float can be made by P 1 Move point to P 2 According to the position deviation signal, the controller changes the current size and direction in the excitation coils A, B, and C to generate appropriate electromagnetic forces F A ,F B ,F C , the resultant force F P =F A +F B +F C The float can be made by P 1 Move point to P 2 point.

[0091] When the float is required to be stable at P 2 At point P, if the float position deviates from P due to external disturbances, etc. 2 point, the sensor will detect the actual position of the float, and compare it with the stable suspension target position P 2 The error information is obtained by comparing the points, and then the magnitude and direction of the current of each excitation coil are obtained according to the force analysis calculation results and the advance adjustment control method to adjust |F A |、|F B |、|F C |, so that F P =F A +F B +F C The float can be adjusted back to the target stable position P 2 point.

[0092] Embodiment 4

[0093] In the first to third embodiments, the excitation coil 3 is an excitation 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 this embodiment, the excitation coil 3 is an excitation coil without a magnetic core or a permanent magnet. Fig. 9 As shown, the excitation coil 3 and the permanent magnet array 2 can be detachably stacked up and down: the excitation 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 disassembled and separated.

[0094] In this embodiment, the excitation coil 3 and the permanent magnet array 2 can be detachably stacked up and down, so that the drive unit is closer to the suspension magnet, which is conducive to increasing the magnetic force between the two. Through the above series of settings, even if no magnetic core or permanent magnet is set in the drive coil, sufficient electromagnetic force between the drive coil and the suspension magnet can be guaranteed. Moreover, the structure of setting the excitation coil on the coil base platform is adopted, and the coil base platform is directly installed on the upper surface of the magnetic stator, which is convenient for disassembly and separation, thereby making it easier to maintain.

[0095] In the above embodiments 1 to 4, the following can be used: Figure 5 The control method shown in Figure 5 As shown in the figure, after the displacement sensor obtains the float position, it is converted into analog and compared with the target position. The difference between the two is 0 as the control target, and the PD operation is performed. The output result generates PWM. After optical coupling isolation, a drive signal is generated and output to the electromagnetic coil. The control process can be added with advance control: the displacement of the float is realized by a small-pitch step method, the actual position of the float is detected in real time by the sensor, and the distance between the final target value and the actual position of the float is divided into several equally spaced target positions. The actual position is compared with the divided target position to obtain error information, and then the magnitude and direction of each excitation coil current are obtained according to the force analysis calculation results and the advance adjustment control method, and an electromagnetic force toward the target position is generated to push the float toward the target position. This advance adjustment control method divides the distance between the final target value and the actual position into several equally spaced target positions, and compares the actual position with the divided target position in turn to obtain error information. Based on the error, multiple small step adjustments are performed to reach the target position. The advance adjustment method can effectively improve the control quality of the controlled object with a large time lag.

[0096] The above specific embodiments only describe the design principle of the present invention. The shapes and names of the components in the description may be different and are not limited. Therefore, those skilled in the art in the field of the present invention may modify or replace the technical solutions recorded in the above embodiments; and these modifications and replacements do not deviate from the creative purpose and technical solutions of the present invention and should all fall within the protection scope of the present invention.

Claims

1. A magnetic levitation device, characterized in that: include: A float (1), a magnetic base and a controller; The float is a cylindrical permanent magnet; the magnetic base comprises a chassis, two excitation coils (3), a permanent magnet array (2) and a float position monitoring unit (4, 5); The chassis is a mounting surface for the excitation coil (3) and the permanent magnet array (2); all the excitation coils (3) and the permanent magnet array (2) are symmetrically distributed with the center of the chassis as the center point Q; the loop formed by the centers of the permanent magnets in the permanent magnet array (2) is located outside the loop formed by the centers of the excitation coils (3); the float position monitoring unit is arranged at the center point Q, and is used to detect the current position P (x p ,y p ), passed to the controller; The controller sets the current position value P(x p ,y p ) is compared with the target position value to generate a position deviation signal. Combined with the force analysis and the calculation results of the electromagnetic force between the excitation coil and the float, the current magnitude and direction in all the excitation coils are changed so that the resultant force F of all the excitation coils on the float P Ability to pull the float to the target position value; When the target position of the magnetic suspension device is the equilibrium point O(0,0): Take the horizontal plane where the center point of the excitation coil is located as the reference plane, take the line connecting the center points A and B of the two excitation coils A and B as the x-axis, and the perpendicular bisector of line segment AB as the y-axis to establish a plane rectangular coordinate system; project the attraction of the two excitation coils vertically onto the reference plane, and the projected attraction is F A and F B ; F A and F B The size of |F A |、|F B |; By F A 、F B Mathematical expression of and The resultant force F can be obtained A +F B By adjusting |F in the mathematical expression A |、|F B | can be combined to form the current float position P(x p ,y p ) The net force F pointing to the equilibrium position O(0,0) P = -μ(x p e x +y p e y ), F P The float can be pulled back to the equilibrium position; Where a is the length of line segment AB, μ is a real coefficient; e x 、e y Represent the x-axis and y-axis unit vectors respectively.

2. The magnetic suspension device according to claim 1, characterized in that: When |F A |、|F B |Satisfaction When the appropriate resultant force F P = -μ(x p e x +y p e y ), where the coefficient F P The float can be moved from the current position P(x p ,y p ) back to the equilibrium position.

3. The magnetic suspension device according to claim 1 or 2, characterized in that: The excitation coil (3) is an excitation 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, and the excitation coil is symmetrically distributed with the center of the chassis as the center point Q; the permanent magnets in the permanent magnet array (2) are distributed around the outside of the excitation coil (3) and are annularly symmetrically distributed with the center point Q as the center.

4. The magnetic suspension device according to claim 1 or 2, characterized in that: The excitation coil (3) does not contain a magnetic core or a permanent magnet: The excitation coil (3) and the permanent magnet array (2) can be detachably stacked up and down: the excitation 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.

5. A magnetic levitation device, characterized in that: include: A float (1), a magnetic base and a controller; The float is a cylindrical permanent magnet; the magnetic base comprises a chassis, three excitation coils (3), a permanent magnet array (2) and a float position monitoring unit (4, 5); The chassis is a mounting surface for the excitation coil (3) and the permanent magnet array (2); all the excitation coils (3) and the permanent magnet array (2) are symmetrically distributed with the center of the chassis as the center point Q; the loop formed by the centers of the permanent magnets in the permanent magnet array (2) is located outside the loop formed by the centers of the excitation coils (3); the float position monitoring unit is arranged at the center point Q, and is used to detect the current position P (x p ,y p ), passed to the controller; The controller sets the current position value P(x p ,y p ) is compared with the target position value to generate a position deviation signal. Combined with the force analysis and the calculation results of the electromagnetic force between the excitation coil and the float, the current magnitude and direction in all the excitation coils are changed so that the resultant force F of all the excitation coils on the float P Ability to pull the float to the target position value; When the target position controlled by the magnetic suspension device is the equilibrium point O(0,0): Take the horizontal plane where the center point of the excitation coil is located as the reference plane, the center points A, B, C of the three excitation coils A, B, C form an equilateral triangle, take the center point O of the equilateral triangle ABC as the coordinate origin, and establish a plane rectangular coordinate system with OA as the y-axis direction; The attractive forces of the three excitation coils are projected vertically onto the reference plane. The projected attractive forces are F A ,F B ,F C ; F A ,F B ,F C The size of |F A |、|F B |、|F C |; By F A 、F B 、F C Mathematical expression of The resultant force F can be obtained A +F B +F C By adjusting |F in the mathematical expression A |、|F B |、|F C | can be combined to form the current float position P(x p ,y p ) The resultant force F pointing to the equilibrium position O(0,0) P = -β(x p e x +y p e y );F P The float can be pulled back to the equilibrium position; where a is the side length of the equilateral triangle ABC, β is a real coefficient; e x 、e y Represent the x-axis and y-axis unit vectors respectively; When the target position controlled by the magnetic levitation device is P2(x2,y2): Change the magnitude and direction of the current in the excitation coils A, B, and C to generate appropriate electromagnetic forces F respectively. A 、F B 、F C , By adjusting |F A |、|F B |、|F C | can be combined to form a resultant force F from the current float position P1 (x1, y1) to the target position P2 (x2, y2). P =γ[(x2-x1)e x +(y2-y1)e y ], where γ is a real coefficient, e x 、e y Respectively represent the x-axis and y-axis unit vectors; F P The float can be moved from point P1 to point P2.

6. The magnetic suspension device according to claim 5, characterized in that: When |F A |、|F B |、|F C |Satisfaction When the appropriate F P = -β(x p e x +y p e y ), where the coefficient F P The float can be moved from the current position P(x p ,y p ) back to the equilibrium position.

7. The magnetic suspension device according to claim 5, characterized in that: When |F A |、|F B |、|F C |Satisfaction When the appropriate F P =γ[(x2-x1)e x +(y2-y1)e y ], where the coefficient F P The float can be moved from point P1 to point P2.

8. The magnetic suspension device according to any one of claims 5 to 7, characterized in that: The excitation coil (3) is an excitation 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, and the excitation coil is symmetrically distributed with the center of the chassis as the center point Q; the permanent magnets in the permanent magnet array (2) are distributed around the outside of the excitation coil (3) and are annularly symmetrically distributed with the center point Q as the center.

9. The magnetic suspension device according to any one of claims 5 to 7, characterized in that: The excitation coil (3) does not contain a magnetic core or a permanent magnet: The excitation coil (3) and the permanent magnet array (2) can be detachably stacked up and down: the excitation 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.

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