Method, apparatus and storage medium for measuring the contact point between stator and float

Abstract

This invention relates to the field of magnetic levitation system technology, and in particular to a method, device, and storage medium for measuring the contact point between the stator and the float. The method for measuring the contact point between the stator and the float (the extreme point of the excitation current-float displacement curve) first determines the search interval range within which the contact point between the stator and the float (the extreme point of the excitation current-float displacement curve) lies. Using an interval optimization method, the search interval is iteratively narrowed until it is sufficiently small, or the current change at several consecutive points is sufficiently small. The iteration stops, and the process returns to the midpoint of the search interval to obtain the contact point between the stator and the float. This invention, by using an interval optimization method to gradually approximate the point, ensures that the contact point between the stator and the float is found within a certain accuracy. Furthermore, during the search process, only the float slightly compresses the stator in the initial stage; the degree of compression by the float on the stator does not become more severe in subsequent stages, thus avoiding levitation instability or structural damage.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of magnetic suspension systems, in particular to a method and device for measuring the contact point between a stator and a floating body and a storage medium. BACKGROUND

[0002] In a magnetic suspension system such as an electromagnetic bearing, in order to detect the gap between the stator and the floating body, the following method is often used: as shown in FIG. 1, the floating body is suspended at a set position of the suspension system, the position of the floating body is changed gradually by constantly changing the suspension system command, until the floating body contacts the stator. Figure 1

[0003] In the above process, as the position of the floating body changes, the magnetic flux density in the suspension system changes accordingly, the magnetic flux density changes in direct proportion to the exciting current, and the exciting current is easy to measure, so the relationship between the current and the displacement of the floating body is often used to determine the contact point between the floating body and the stator. When the floating body is not in contact with the stator, the floating body is not subjected to the supporting force of the stator; when the floating body contacts the stator, the floating body is pressed against the stator and thus subjected to the supporting force of the stator. Therefore, the current-displacement trend before and after the contact between the floating body and the stator is different, and the extreme point (maximum or minimum) of the current-displacement curve theoretically corresponds to the contact point between the floating body and the stator, as shown in FIG. 2. Figure 2

[0004] The commonly used contact point monitoring method is shown in FIG. 3, in which displacement points (marked with x in the figure) are uniformly selected, but this method cannot accurately obtain the extreme point of the current-displacement curve, affecting the measurement accuracy; the selection of points is blind, and the displacement of the floating body may be large, in which case the floating body is pressed against the stator severely, which may damage the floating body and the stator structure, and the data with large displacement is not significant for determining the contact point; when the floating body is pressed against the stator severely, the contact force affects the suspension stability, which may cause unstable suspension, violent vibration of the floating body, affect the measurement accuracy, and damage the floating body and the stator structure. Figure 3 SUMMARY

[0005] Therefore, the present application aims to overcome the problems of low measurement accuracy and damage to the floating body and the stator structure in the prior art.

[0006] To solve the above technical problems, the present application provides a method for measuring the contact point between a stator and a floating body, comprising:

[0007] Step 1: Obtain a plurality of continuous suspension position points that satisfy a preset condition, and determine the search interval of the contact point between the stator and the floating body on the exciting current-floating body displacement curve;

[0008] ​​​Step 2: When the search interval size does not reach the displacement threshold, and the difference in excitation current between two adjacent floating position points in the continuous multiple floating position points does not reach the current threshold, then the search interval is reduced and the continuous multiple floating position points are updated according to the magnitude relationship between the excitation currents corresponding to the continuous multiple floating position points.

[0009] Step 3: Repeat Step 2 until the updated multiple floating position points no longer meet the execution conditions of Step 2. Then, output the midpoint of the updated search interval as the contact point between the stator and the float.

[0010] Preferably, the number of the consecutive multiple suspended position points is 3.

[0011] Preferably, the preset condition includes the fact that the excitation current is the largest at the second floating position point in the middle of three consecutive floating position points.

[0012] Preferably, the specific process of step one includes:

[0013] Set initial displacement displacement step size And the initial number of iterations n=1;

[0014] The displacement step size changes the levitation position of the float. And record the corresponding excitation current. ;

[0015] Calculate whether the current three consecutive floating positions satisfy the preset condition, and the calculation expression is as follows: ;

[0016] If the current three consecutive floating positions do not meet the preset conditions, the floating position of the float continues to change according to the displacement step size, and the iteration step number is updated. The calculation expression is as follows: ;

[0017] If the current three consecutive floating position points meet the preset conditions, then the interval between the first floating position point and the third floating position point on the excitation current-float displacement curve is set as the search interval for the contact point between the stator and the float, and then proceed to step two.

[0018] Preferably, the recorded excitation current includes:

[0019] Determine whether the float is in a stable suspended state;

[0020] When the float is in a stable levitation state, the corresponding excitation current is recorded.

[0021] Preferably, the specific process of step three includes:

[0022] If the updated three floating position points do not meet the execution conditions of step two, namely: the size of the reduced search interval reaches the displacement threshold, or the difference in excitation current between any two adjacent floating position points reaches the current threshold, the formula is expressed as: Then the updated search interval midpoint, i.e. the second floating position point, will be output as the contact point between the stator and the float.

[0023] in, This is the first floating position point. This is the second floating position point. This is the third floating position point. for The corresponding excitation current, for The corresponding excitation current, for The corresponding excitation current, The displacement threshold is... The current threshold is defined as .

[0024] Preferably, the step of narrowing the search interval and updating the consecutive floating position points based on the magnitude relationship between the excitation currents corresponding to the multiple consecutive floating position points includes:

[0025] First floating position point Corresponding excitation current Not greater than the second floating position point Corresponding excitation current And the first floating position point Corresponding excitation current Greater than the third floating position point Corresponding excitation current or the first floating position point Corresponding excitation current Greater than the second floating position point Corresponding excitation current And the first floating position point Corresponding excitation current Less than the third floating position point Corresponding excitation current When, the first floating position point is recorded as Change the levitation position of the floating element to And record the corresponding excitation current. ,in, Interval factor;

[0026] right , Second Floating Position Sort them in ascending order and re-record them as the first floating position point, the second floating position point, and the third floating position point.

[0027] Preferably, the step of narrowing the search interval and updating the consecutive floating position points based on the magnitude relationship between the excitation currents corresponding to the multiple consecutive floating position points includes:

[0028] First floating position point Corresponding excitation current Not greater than the second floating position point Corresponding excitation current And the first floating position point Corresponding excitation current Not greater than the third floating position point Corresponding excitation current or the first floating position point Corresponding excitation current Greater than the second floating position point Corresponding excitation current And the first floating position point Corresponding excitation current Not less than the third floating position point Corresponding excitation current At that time, the third floating position point is recorded as Change the levitation position of the float to And record the corresponding excitation current. ,in, Interval factor;

[0029] right , Second Floating Position Sort them in ascending order and re-record them as the first floating position point, the second floating position point, and the third floating position point.

[0030] The present invention also provides a device for measuring the contact point between the stator and the float, comprising:

[0031] The search interval acquisition module is used to acquire multiple consecutive floating position points that meet preset conditions, and to determine the search interval of the contact point between the stator and the float on the excitation current-float displacement curve.

[0032] Search interval optimization module: When the search interval size does not reach the displacement threshold, and the difference in excitation current between two adjacent floating position points in the continuous multiple floating position points does not reach the current threshold, it is used to reduce the search interval and update the continuous multiple floating position points according to the magnitude relationship between the excitation currents corresponding to the continuous multiple floating position points.

[0033] The contact point measurement module is used to repeat the steps of the search interval optimization module until the updated multiple floating position points no longer meet the execution conditions of the search interval optimization module. Then, the updated search interval midpoint is output as the contact point between the stator and the float.

[0034] The present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the above-described method for measuring the contact point between a stator and a float.

[0035] The technical solution of the present invention has the following advantages compared with the prior art:

[0036] The stator-float contact point measurement method of this invention first preliminarily determines the search interval range where the stator-float contact point (excitation current-float displacement curve extreme point) is located. Using an interval optimization method, the search interval is iteratively narrowed until the search interval is small enough, or the current change at several consecutive points is small enough. Then, the iteration stops, and the search interval is returned to the middle point to obtain the stator-float contact point. This invention uses an interval optimization method to gradually approximate the point, ensuring that the stator-float contact point is found within a certain accuracy. Furthermore, during the search process, the float only needs to slightly squeeze the stator in the initial stage. In subsequent stages, the squeezing degree of the float on the stator will not become more severe, avoiding levitation instability or structural damage. Attached Figure Description

[0037] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein:

[0038] Figure 1 This is a schematic diagram of the suspension system;

[0039] Figure 2 This is a schematic diagram of the excitation current-float displacement curve;

[0040] Figure 3 This is a schematic diagram of uniformly selecting displacement points in existing contact point monitoring methods;

[0041] Figure 4 A flowchart illustrating the implementation of a method for measuring the contact point between a stator and a float provided by this invention;

[0042] Figure 5 This is a flowchart illustrating the initial determination of the search interval in one embodiment of the present invention;

[0043] Figure 6 This is a flowchart illustrating the implementation of optimizing the search interval in one embodiment of the present invention. Detailed Implementation

[0044] The core of this invention is to provide a method, apparatus, device, and computer storage medium for measuring the contact point between the stator and the float, which improves measurement accuracy and avoids levitation instability or structural damage.

[0045] To enable those skilled in the art to better understand the present invention, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] Please refer to Figure 4. Figure 4 The flowchart illustrates the implementation of a method for measuring the contact point between a stator and a float provided by this invention; the specific operation steps are as follows:

[0047] S101: Obtain multiple consecutive floating position points that meet the preset conditions, and determine the search interval of the contact point between the stator and the float on the excitation current-float displacement curve.

[0048] S102: When the search interval size does not reach the displacement threshold, and the difference in excitation current between two adjacent floating position points among the consecutive multiple floating position points does not reach the current threshold, then the search interval is reduced and the consecutive multiple floating position points are updated according to the magnitude relationship between the excitation currents corresponding to the consecutive multiple floating position points.

[0049] S103: Repeat step S102 until the updated multiple floating position points no longer meet the execution conditions of step S102, then output the midpoint of the updated search interval as the contact point between the stator and the float.

[0050] Based on the above embodiments, the present invention only needs to find three consecutive floating position points that meet the preset conditions to determine the search interval of the contact point between the stator and the float on the excitation current-float displacement curve, that is, the interval from the first floating position point to the third floating position point on the excitation current-float displacement curve; the preset conditions include that the excitation current is the largest at the second floating position point in the middle of the three consecutive floating position points.

[0051] likeFigure 5 As shown, based on the above embodiments, this embodiment further explains step S101, and its specific process includes:

[0052] Set initial displacement displacement step size And the initial number of iterations n=1;

[0053] The displacement step size changes the levitation position of the float. And record the corresponding excitation current. The recording of the corresponding excitation current includes: determining whether the float is in a stable levitation state, and recording the corresponding excitation current when the float is in a stable levitation state;

[0054] Calculate whether the current three consecutive floating positions satisfy the preset condition, and the calculation expression is as follows: ;

[0055] If the current three consecutive floating positions do not meet the preset conditions, the floating position of the float continues to change according to the displacement step size, and the iteration step number is updated. The calculation expression is as follows: ;

[0056] If the current three consecutive floating position points meet the preset conditions, then the interval from the first floating position point to the third floating position point on the excitation current-float displacement curve is set as the search interval for the contact point between the stator and the float, and the process proceeds to step S102.

[0057] like Figure 6 Based on the above embodiments, this embodiment further explains step S102, which involves narrowing the search interval and updating the multiple consecutive floating position points according to the magnitude relationship between the excitation currents corresponding to the multiple consecutive floating position points:

[0058] First floating position point Corresponding excitation current Not greater than the second floating position point Corresponding excitation current And the first floating position point Corresponding excitation current Greater than the third floating position point Corresponding excitation current or the first floating position point Corresponding excitation current Greater than the second floating position point Corresponding excitation current And the first floating position point Corresponding excitation current Less than the third floating position point Corresponding excitation current When, the first floating position point is recorded as Change the levitation position of the float to And record the corresponding excitation current. ,in, For interval factors; , and the second floating position point Sort them in ascending order and re-record them as the first floating position point, the second floating position point, and the third floating position point.

[0059] First floating position point Corresponding excitation current Not greater than the second floating position point Corresponding excitation current And the first floating position point Corresponding excitation current Not greater than the third floating position point Corresponding excitation current or the first floating position point Corresponding excitation current Greater than the second floating position point Corresponding excitation current And the first floating position point Corresponding excitation current Not less than the third floating position point Corresponding excitation current At that time, the third floating position point is recorded as Change the levitation position of the float to And record the corresponding excitation current. ,in, For interval factors; , and the second floating position point Sort them in ascending order and re-record them as the first floating position point, the second floating position point, and the third floating position point.

[0060] Based on the above embodiments, this embodiment further explains step S103:

[0061] If the updated three floating position points do not meet the execution conditions of step S102, namely: the size of the reduced search interval reaches the displacement threshold, or the difference in excitation current between any two adjacent floating position points reaches the current threshold, the formula is expressed as: Then the updated search interval midpoint, i.e. the second floating position point, will be output as the contact point between the stator and the float.

[0062] in, This is the first floating position point. This is the second floating position point. This is the third floating position point. for The corresponding excitation current, for The corresponding excitation current, for The corresponding excitation current, The displacement threshold is... The current threshold is defined as .

[0063] The stator-floor contact point measurement method described in this invention uses a conventional uniform sampling method to search until the search interval range of the stator-floor contact point (extreme point of the excitation current-floor displacement curve) is initially determined. Then, using an interval optimization method, the search interval is iteratively narrowed until it is sufficiently small, or the current change at several consecutive points is sufficiently small. At this point, the iteration stops, and the method returns to the midpoint of the current search interval to obtain the stator-floor contact point. This invention uses an interval optimization method to gradually approximate the point, ensuring that the stator-floor contact point is found within a certain accuracy. Furthermore, during the search process, only the float slightly compresses the stator in the initial stage; the compression of the stator by the float does not become more severe in subsequent stages, thus avoiding levitation instability or structural damage.

[0064] The stator-float contact point measurement method of the present invention ensures that the displacement of the float will not exceed the initially established search space throughout the entire search process. Therefore, it avoids excessive pressure from the float on the stator, which could cause levitation instability or structural damage. On the other hand, by gradually narrowing the interval containing the extreme point, it ensures that the extreme point can be finally found, and the error will not exceed [the specified limit]. or The corresponding displacement.

[0065] Based on the above embodiments, the present invention also provides a stator-floor contact point measuring device, comprising:

[0066] The search interval acquisition module is used to acquire multiple consecutive floating position points that meet preset conditions, and to determine the search interval of the contact point between the stator and the float on the excitation current-float displacement curve.

[0067] Search interval optimization module: When the search interval size does not reach the displacement threshold, and the difference in excitation current between two adjacent floating position points in the continuous multiple floating position points does not reach the current threshold, it is used to reduce the search interval and update the continuous multiple floating position points according to the magnitude relationship between the excitation currents corresponding to the continuous multiple floating position points.

[0068] The contact point measurement module is used to repeat the steps of the search interval optimization module until the updated multiple floating position points no longer meet the execution conditions of the search interval optimization module. Then, the updated search interval midpoint is output as the contact point between the stator and the float.

[0069] The stator and float contact point measuring device of this embodiment is used to implement the aforementioned stator and float contact point measuring method. Therefore, the specific implementation of the stator and float contact point measuring device can be found in the previous embodiment section of the stator and float contact point measuring method. For example, the search interval acquisition module 100, the search interval optimization module 200, and the contact point measuring module 300 are respectively used to implement steps S101, S102, and S103 in the above stator and float contact point measuring method. Therefore, the specific implementation can be referred to the description of the corresponding embodiments, which will not be repeated here.

[0070] A specific embodiment of the present invention also provides a stator-floor contact point measuring device, comprising: a memory for storing a computer program; and a processor for executing the computer program to implement the steps of the above-described stator-floor contact point measuring method.

[0071] A specific embodiment of the present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the above-described method for measuring the contact point between a stator and a float.

[0072] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0073] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0074] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0075] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0076] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for measuring the contact point between a stator and a float, characterized in that, include: Step 1: Obtain multiple consecutive floating position points that meet preset conditions, and determine the search interval of the stator-float contact point on the excitation current-float displacement curve. The number of the multiple consecutive floating position points is 3. The preset conditions include that among three consecutive floating position points, the second floating position point in the middle position corresponds to the largest excitation current. The specific process of step one includes: Set initial displacement displacement step size And the initial number of iterations n=1; The displacement step size changes the levitation position of the float. And record the corresponding excitation current. ; Calculate whether the current three consecutive floating positions satisfy the preset condition, and the calculation expression is as follows: ; If the current three consecutive floating positions do not meet the preset conditions, the floating position of the float continues to change according to the displacement step size, and the iteration step number is updated. The calculation expression is as follows: ; If the current three consecutive floating position points meet the preset conditions, then the interval from the first floating position point to the third floating position point on the excitation current-floating sub-displacement curve is set as the search interval for the contact point between the stator and the floating sub-displacement, and then proceed to step two. Step 2: When the search interval size does not reach the displacement threshold, and the difference in excitation current between two adjacent floating position points in the continuous multiple floating position points does not reach the current threshold, then the search interval is reduced and the continuous multiple floating position points are updated according to the magnitude relationship between the excitation currents corresponding to the continuous multiple floating position points. Step 3: Repeat Step 2 until the updated multiple floating position points no longer meet the execution conditions of Step 2. Then, output the midpoint of the updated search interval as the contact point between the stator and the float.

2. The method for measuring the contact point between the stator and the float according to claim 1, characterized in that, The excitation current corresponding to the record includes: Determine whether the float is in a stable suspended state; When the float is in a stable levitation state, the corresponding excitation current is recorded.

3. The method for measuring the contact point between the stator and the float according to claim 1, characterized in that, The specific process of step three includes: If the updated three floating position points do not meet the execution conditions of step two, namely: the size of the reduced search interval reaches the displacement threshold, or the difference in excitation current between any two adjacent floating position points reaches the current threshold, the formula is expressed as: Then the updated search interval midpoint, i.e. the second floating position point, will be output as the contact point between the stator and the float. in, This is the first floating position point. This is the second floating position point. This is the third floating position point. for The corresponding excitation current, for The corresponding excitation current, for The corresponding excitation current, The displacement threshold is... The current threshold is defined as .

4. The method for measuring the contact point between the stator and the float according to claim 1, characterized in that, The step of narrowing the search interval and updating the consecutive floating position points based on the magnitude relationship between the excitation currents corresponding to the consecutive multiple floating position points includes: When the first floating position point Corresponding excitation current Not greater than the second floating position point Corresponding excitation current And the first floating position point Corresponding excitation current Greater than the third floating position point Corresponding excitation current or the first floating position point Corresponding excitation current Greater than the second floating position point Corresponding excitation current And the first floating position point Corresponding excitation current Less than the third floating position point Corresponding excitation current When, the first floating position point is recorded as Change the levitation position of the floating element to And record the corresponding excitation current. ,in, Interval factor; right , Second Floating Position Sort them in ascending order and re-record them as the first floating position point, the second floating position point, and the third floating position point.

5. The method for measuring the contact point between the stator and the float according to claim 1, characterized in that, The step of narrowing the search interval and updating the consecutive floating position points based on the magnitude relationship between the excitation currents corresponding to the consecutive multiple floating position points includes: First floating position point Corresponding excitation current Not greater than the second floating position point Corresponding excitation current And the first floating position point Corresponding excitation current Not greater than the third floating position point Corresponding excitation current or the first floating position point Corresponding excitation current Greater than the second floating position point Corresponding excitation current And the first floating position point Corresponding excitation current Not less than the third floating position point Corresponding excitation current At that time, the third floating position point is recorded as Change the levitation position of the floating element to And record the corresponding excitation current. ,in, Interval factor; right , Second Floating Position Sort them in ascending order and re-record them as the first floating position point, the second floating position point, and the third floating position point.

6. A device for measuring the contact point between a stator and a float, characterized in that, include: The search interval acquisition module is used to acquire multiple consecutive floating position points that meet preset conditions, and to determine the search interval of the contact point between the stator and the float on the excitation current-float displacement curve. The number of the multiple consecutive floating position points is 3, and the preset conditions include that the excitation current is the largest at the second floating position point in the middle of the three consecutive floating position points. It is specifically used for: Set initial displacement displacement step size And the initial number of iterations n=1; The displacement step size changes the levitation position of the float. And record the corresponding excitation current. ; Calculate whether the current three consecutive floating positions satisfy the preset condition, and the calculation expression is as follows: ; If the current three consecutive floating positions do not meet the preset conditions, the floating position of the float continues to change according to the displacement step size, and the iteration step number is updated. The calculation expression is as follows: ; If the current three consecutive floating position points meet the preset conditions, then the interval from the first floating position point to the third floating position point on the excitation current-floating sub-displacement curve is set as the search interval for the contact point between the stator and the floating sub-displacement, and the steps of the search interval optimization module are executed. Search interval optimization module: When the search interval size does not reach the displacement threshold, and the difference in excitation current between two adjacent floating position points in the continuous multiple floating position points does not reach the current threshold, it is used to reduce the search interval and update the continuous multiple floating position points according to the magnitude relationship between the excitation currents corresponding to the continuous multiple floating position points. The contact point measurement module is used to repeat the steps of the search interval optimization module until the updated multiple floating position points no longer meet the execution conditions of the search interval optimization module. Then, the updated search interval midpoint is output as the contact point between the stator and the float.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the method for measuring the contact point between a stator and a float as described in any one of claims 1 to 5.

Images