A method and system for feedback control of a magnetic levitation gap

Abstract

The application discloses a kind of magnetic suspension gap feedback control methods, comprising: establishing the magnetic suspension system electromagnet control model for indicating the relationship between the control voltage of electromagnet and magnetic flux;By state space equation representation method, the magnetic suspension system electromagnet control model is converted into state space expression;Magnetic suspension system total disturbance is added as new state variable of state space expression, and the extended state system including magnetic suspension system total disturbance is established;The extended state observer of the extended state system is established, and the observation gain function and control quantity of the extended state observer are set to build the integral series type magnetic suspension system for carrying out magnetic suspension gap control;Based on integral series type magnetic suspension system, the feedback control of magnetic suspension gap is carried out.The scheme of the application can effectively improve the accuracy and stability of control, realize the feedback control of magnetic suspension gap.The application also discloses a kind of magnetic suspension gap feedback control system, with corresponding technical effects.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of rail transit, in particular to a feedback control method and system for magnetic suspension gap. BACKGROUND

[0002] At present, the control method of the magnetic suspension system is to establish the magnetic suspension system equation, Taylor linearization expansion is carried out on the magnetic suspension system equation near the suspension working point, and the high-order small amount is omitted, and then the feedback is designed according to the error between the control target and the measured response, and the control law is designed by combining the classical control theory and the modern control theory.

[0003] The limitation of the existing conventional method is that when the magnetic suspension system works, it will be disturbed by external load, track and other excitations, so that the working point will fluctuate, and the control method of linear expansion of the working point will introduce the control model error at the beginning of the design, so that when the working point deviation is large, the original set control parameters are not matched and the application range is limited. In addition, the processing of external disturbance and system parameter change is to control adjustment after the system deviation occurs, which has a lag problem.

[0004] In summary, how to effectively control the magnetic suspension system and improve the accuracy and stability of the control is a technical problem that needs to be solved by the technical personnel in the field at present. SUMMARY

[0005] The purpose of the present application is to provide a feedback control method and system for magnetic suspension gap, so as to effectively control the magnetic suspension system and improve the accuracy and stability of the control.

[0006] To solve the above technical problems, the present application provides the following technical scheme:

[0007] A feedback control method for magnetic suspension gap, comprising:

[0008] establishing a magnetic suspension system electromagnet control model for representing the relationship between the control voltage of electromagnet and the magnetic flux;

[0009] convert the magnetic suspension system electromagnet control model into a state space expression by state space equation representation method;

[0010] regard the total disturbance of the magnetic suspension system as a new state variable of the state space expression, and establish an extended state system including the total disturbance of the magnetic suspension system;

[0011] establish an extended state observer of the extended state system, and set the observation gain function and the control amount of the extended state observer, so as to construct an integral series magnetic suspension system for controlling the magnetic suspension gap;

[0012] The integral series type maglev system is used to perform feedback control on a maglev gap.

[0013] Preferably, the maglev system electromagnet control model representing the relationship between the control voltage and the magnetic flux of the electromagnet is established by:

[0014] The third-order maglev system electromagnet control model or the first-order maglev system electromagnet control model representing the relationship between the control voltage and the magnetic flux of the electromagnet is established.

[0015] Preferably, the third-order maglev system electromagnet control model representing the relationship between the control voltage and the magnetic flux of the electromagnet is established by:

[0016] The maglev system relationship is established to represent the relationship between the magnetic flux and the electromagnet attraction force.

[0017] The maglev system dynamic balance relationship is established to represent the motion state of the electromagnet based on the displacement z of the electromagnet relative to the track surface and the track irregularity r.

[0018] The maglev system dynamic balance relationship is upgraded and substituted into the differential expression of the magnetic flux and the upgraded maglev system relationship to obtain a third-order electromagnet control equation as the established third-order maglev system electromagnet control model.

[0019] Preferably, the established maglev system relationship is represented as:

[0020] The established maglev system dynamic balance relationship is represented as:

[0021] The differential expression of the magnetic flux is established according to Faraday's law of electromagnetic induction and Kirchhoff's second law and is represented as:

[0022] The obtained third-order electromagnet control equation is represented as:

[0023] wherein, F s is the suspension force acting on the electromagnet, F m is the electromagnet attraction force, f is an external disturbance excitation, φ is the magnetic flux, μ0 is the vacuum permeability, A is twice the area of the electromagnet armature surface, m is the mass of the electromagnet, t is time, N is the number of turns of the electromagnet induction coil, I is the electromagnet control current, u is the electromagnet control voltage, R e is the equivalent resistance of the electromagnet.

[0024] Preferably, the established expansion state system representing the total disturbance of the maglev system is represented as:

[0025]

[0026] The extended state observer of the extended state system is represented as:

[0027]

[0028] wherein z1, z2, z3, z4 are state variables of the electromagnet control system, y is the system output, μ0 is the vacuum permeability, b0 is a set parameter, f total is the total disturbance of the magnetic levitation system, is the observed value of the electromagnet control current, is the observed value of the magnetic flux, are observed values of the state variables of the electromagnet control system, is the observed value of the system output, β 01 (e), β 02 (e), β 03 (e) and β 04 (e) are observation gain functions of the extended state observer, and e is an error and e = z1-y.

[0029] Preferably, a first-order magnetic levitation system electromagnet control model for representing the relationship between the control voltage of the electromagnet and the magnetic flux is established, comprising:

[0030] A magnetic flux expression based on the magnetic resistance is determined

[0031] The magnetic flux expression is upgraded and substituted into the differential expression of the magnetic flux to obtain a first-order electromagnet control equation as the established first-order magnetic levitation system electromagnet control model;

[0032] wherein N is the number of turns of the electromagnet induction coil, I is the electromagnet control current, R is the magnetic resistance, and φ is the magnetic flux.

[0033] Preferably, the magnetic resistance is a magnetic resistance based on the electromagnet suspension gap length δ, and the magnetic resistance is represented as

[0034]

[0035] wherein μ is the medium permeability, L is the electromagnet coil length, S is the area perpendicular to the magnetic field direction, and δ is the electromagnet suspension gap length.

[0036] Preferably, the magnetic resistance is a magnetic resistance based on the electromagnet suspension gap length δ and the permeability μ, and the magnetic resistance is represented as

[0037] Wherein, k is the value of the magnetic permeability μ of the unsaturated section, μ is the magnetic permeability of the medium, L is the length of the electromagnet coil, S is the area perpendicular to the magnetic field direction, and δ is the length of the electromagnet suspension gap.

[0038] Preferably, the established extended state system including the total disturbance of the magnetic levitation system is represented as:

[0039]

[0040] The extended state observer of the established extended state system is represented as:

[0041]

[0042] Wherein, z1 and z2 are state variables of the electromagnet control system, y is the system output, f total is the total disturbance of the magnetic levitation system, is the observed value of the electromagnet control current, is the observed value of the magnetic flux, are observed values of the state variables of the electromagnet control system, is the observed value of the system output, β 01 (e) and β 02 (e) are observation gain functions of the extended state observer, e is an error and e = z1-y, f unk is the sum of all internal and external disturbances suffered by the magnetic levitation system, A1 and A2 are set parameters, and R e is the equivalent resistance of the electromagnet, and u is the electromagnet control voltage.

[0043] A feedback control system of a magnetic levitation gap, comprising:

[0044] An electromagnet control model establishing module, configured to establish a magnetic levitation system electromagnet control model for representing the relationship between the control voltage and the magnetic flux of the electromagnet;

[0045] A state space expression establishing module, configured to convert the magnetic levitation system electromagnet control model into a state space expression by state space equation representation;

[0046] An extended state system establishing module, configured to establish an extended state system including the total disturbance of the magnetic levitation system by taking the total disturbance of the magnetic levitation system as a new state variable of the state space expression;

[0047] An integral series type magnetic levitation system constructing module, configured to establish an extended state observer of the extended state system, and set the observation gain function and the control quantity of the extended state observer, so as to construct an integral series type magnetic levitation system for performing magnetic levitation gap control;

[0048] The feedback control execution module is configured to perform feedback control of the magnetic suspension gap based on the integral series magnetic suspension system.

[0049] The technical scheme provided by the embodiment of the application can establish a magnetic suspension system electromagnet control model for representing the relationship between the control voltage and the magnetic flux of the electromagnet. The magnetic suspension system electromagnet control model is converted into a state space expression by state space equation representation, which facilitates calculation. The total disturbance of the magnetic suspension system is taken as a new state variable of the state space expression, an extended state system including the total disturbance of the magnetic suspension system is established, an extended state observer of the extended state system is established, and the observation gain function and the control quantity of the extended state observer are set to construct an integral series magnetic suspension system for performing magnetic suspension gap control. It can be seen that, since the total disturbance of the magnetic suspension system is taken as a new state variable of the state space expression and the extended state system including the total disturbance of the magnetic suspension system is established, the scheme of the application can compensate for the total disturbance at the control input end, thereby converting the magnetic suspension system into a simple integral series control object, and the accuracy and stability of control can be effectively improved, and feedback control of the magnetic suspension gap can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0050] In order to more clearly illustrate the technical scheme in the embodiments of the application or the prior art, the drawings needed in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative effort.

[0051] Figure 1 An implementation flowchart of the magnetic suspension gap feedback control method in the application;

[0052] Figure 2 A structural schematic diagram of the magnetic suspension gap feedback control system in the application. DETAILED DESCRIPTION

[0053] The core of the application is to provide a magnetic suspension gap feedback control method, which can effectively improve the accuracy and stability of control and realize feedback control of the magnetic suspension gap.

[0054] In order to make the technical personnel in the art better understand the application scheme, the application will be further described in detail below with reference to the drawings and specific embodiments. Obviously, the described embodiments are only some of the embodiments of the application, not all. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the application.

[0055] Please refer toFigure 1 , Figure 1 is an embodiment flow chart of a feedback control method of a magnetic suspension gap in the application, and the feedback control method of the magnetic suspension gap can include the following steps:

[0056] Step S101: establishing a magnetic suspension system electromagnet control model for representing the relationship between the control voltage of the electromagnet and the magnetic flux.

[0057] Specifically, the magnetic suspension system electromagnet control model can be generally represented as an electromagnet control equation, which needs to be able to represent the relationship between the control voltage of the electromagnet and the magnetic flux. In actual application, the establishment of the electromagnet control equation can be based on parameters such as magnetic flux and current.

[0058] In a specific embodiment of the application, step S101 can specifically include: establishing a third-order magnetic suspension system electromagnet control model or a first-order magnetic suspension system electromagnet control model for representing the relationship between the control voltage of the electromagnet and the magnetic flux, and then a third-order or first-order integral series type magnetic suspension system can be constructed accordingly.

[0059] This embodiment takes into account that the control performance of the integral series type magnetic suspension system of different orders is different under different environments, which can be affected by factors such as the hardware equipment of the vehicle, specific algorithm programs, etc. Therefore, in actual application, the most suitable order of the integral series type magnetic suspension system can be selected according to the actual application environment. That is, when step S101 is performed, it can be selected whether to establish a third-order magnetic suspension system electromagnet control model or a first-order magnetic suspension system electromagnet control model according to actual needs. And through different expressions of the magnetic flux, the establishment of the third-order or first-order magnetic suspension system electromagnet control model can be realized.

[0060] In a specific embodiment of the application, the operation of establishing a third-order magnetic suspension system electromagnet control model for representing the relationship between the control voltage of the electromagnet and the magnetic flux can specifically include:

[0061] Step one: establishing a magnetic suspension system relationship for representing the relationship between the magnetic flux and the electromagnet attraction force;

[0062] Step two: based on the displacement z of the electromagnet relative to the track surface and the track irregularity amount r, establishing a magnetic suspension system dynamic balance relationship for representing the motion state of the electromagnet;

[0063] Step three: the magnetic suspension system dynamic balance relationship is upgraded, and the differential expression of the magnetic flux and the upgraded magnetic suspension system relationship are substituted into the third-order electromagnet control equation, which is taken as the established third-order magnetic suspension system electromagnet control model.

[0064] In the embodiment, since a third-order maglev system electromagnet control model is to be established, a maglev system relationship based on magnetic flux is selected to represent the magnetic flux. Specifically, an Ampere loop theorem of a magnetic circuit, a second Kirchhoff theorem of the magnetic circuit, an electromagnet suction force formula, and an electromagnet motion equation are utilized to establish the maglev system relationship based on the magnetic flux, which can reflect a corresponding relationship between the magnetic flux and the electromagnet suction force and can be expressed as formula (1), i.e., the formula is used as an expression form of the magnetic flux.

[0065]

[0066] The electromagnet displacement in the absolute coordinate system can be expressed as two parts: a displacement z of the electromagnet relative to a track surface and a track irregularity r. Therefore, the maglev system dynamic balance relationship established can be expressed as formula (2).

[0067]

[0068] Formula (3) can be obtained by upgrading formula (2), and formula (4) can be obtained by upgrading formula (1).

[0069]

[0070]

[0071] Since Therefore, a differential expression of the magnetic flux established according to the Faraday's law of electromagnetic induction and the second Kirchhoff theorem can be expressed as formula (5).

[0072]

[0073] Formula (3) can be obtained by bringing formula (5) and formula (4) into formula (3), and a third-order electromagnet control equation can be obtained. The third-order electromagnet control equation can be used as the third-order maglev system electromagnet control model established. The third-order electromagnet control equation can be expressed as formula (6).

[0074]

[0075] In formula (6), F is a suspension force acting on the electromagnet, F is an electromagnet suction force, f is an external disturbance excitation, φ is the magnetic flux, μ0 is a vacuum permeability, A is twice an electromagnet armature area, m is an electromagnet mass, t is time, N is a number of turns of an electromagnet induction coil, I is an electromagnet control current, u is an electromagnet control voltage, R is an equivalent resistance of the electromagnet, and F s m e

[0076] ​​​Step S102: Convert the maglev system electromagnet control model into a state space expression by state space equation representation.

[0077] By state space equation representation, the maglev system electromagnet control model is converted into a state space expression. Since this operation reduces the order of the maglev system electromagnet control model, it is convenient for subsequent calculation.

[0078] Still taking the three-order electromagnet control equation established in the foregoing embodiment as an example, that is, by state space equation representation, formula (6) can be reduced in order to obtain a state space expression, that is, a multi-dimensional first-order system. It can be expressed as:

[0079]

[0080] Step S103: Take the total disturbance of the maglev system as a new state variable of the state space expression, and establish an extended state system including the total disturbance of the maglev system.

[0081] The present application takes the total disturbance of the maglev system as a new state variable of the state space expression. For example, the three-order electromagnet control equation established in the foregoing embodiment is converted into formula (7) after being converted into a state space expression. The total disturbance f of the maglev system can be taken as a new state variable z4. total It is defined as:

[0082]

[0083] And take it as a state variable z4.

[0084] Therefore, the extended state system including the total disturbance of the maglev system can be expressed as:

[0085]

[0086] Step S104: Establish an extended state observer of the extended state system, and set the observation gain function and control amount of the extended state observer to build an integral series type maglev system for performing maglev gap control.

[0087] After the extended state system is established, a corresponding extended state observer needs to be established to observe the state variable, and the observation gain function and control amount of the extended state observer need to be set, thereby building an integral series type maglev system for performing maglev gap control.

[0088] Taking the extended state system established in the foregoing embodiment as formula (9) for example, an error e = z1-y can be defined, and the extended state observer of the state extended system can be expressed as:

[0089]

[0090] In formula (7) to formula (10), z1, z2, z3, z4 are state variables of the electromagnet control system, y is the system output, μ0 is the vacuum permeability, b0 is a set parameter, f total is the total disturbance of the magnetic levitation system, is the observed value of the electromagnet control current, is the observed value of the magnetic flux, are observed values of the state variables of the electromagnet control system, is the observed value of the system output, β 01 (e), β 02 (e), β 03 (e) and β 04 (e) are observation gain functions of the extended state observer, and e is an error and e=z1-y.

[0091] β 01 (e), β 02 (e), β 03 (e) and β 04 (e) can be in a linear form, that is, directly defined as a linear multiple of the error e, and can be combined with the pole placement method and the observation bandwidth requirement to obtain the parameter configuration of the extended state observer. It can also be in a nonlinear form, for example, it can be in a nonlinear form as shown in formula (11), and obtained by adjusting parameters a and γ.

[0092]

[0093] Under the action of appropriate observer gain parameters and within a certain observer bandwidth, the extended state observer can achieve the following state estimation effect:

[0094] The set control quantity can be represented as:

[0095]

[0096] Wherein, u0 represents a virtual control quantity, and the parameter b0 is Substituted into formula (10) and simplified, the following formula (13) can be obtained:

[0097]

[0098] And since Therefore, formula (13) can be simplified as:

[0099] Therefore, under the feedback action of the extended state observer, the third-order integral series type magnetic levitation system constructed can be represented as:

[0100]

[0101] It should be further noted that for the selection of the parameter b0, the initial value can be set as, for example: φ0 is the magnetic flux under the rated load of the electromagnet, which is subsequently updated in real time online according to the observation of According to .

[0102] Step S105: Feedback control of the magnetic levitation gap based on the integral series type magnetic levitation system.

[0103] After obtaining the integral series type magnetic levitation system, the controller design can be carried out on the integral series type magnetic levitation system in combination with classical and modern control methods, such as PD controller design method, pole placement method, nonlinear PID method, etc., so as to realize the feedback control of the magnetic levitation gap.

[0104] In the foregoing embodiments, a third-order electromagnet control equation is established to obtain a third-order integral series type magnetic levitation system, and in one specific embodiment of the present application, a first-order magnetic levitation system electromagnet control model is established for representing the relationship between the control voltage and the magnetic flux of the electromagnet, which can specifically include:

[0105] Step one: determine the magnetic flux expression based on magnetic resistance

[0106] Step two: upgrade the magnetic flux expression and substitute it into the differential expression of the magnetic flux to obtain a first-order electromagnet control equation as a first-order magnetic levitation system electromagnet control model;

[0107] Wherein, N is the number of turns of the electromagnet inductor coil, I is the electromagnet control current, R is the magnetic resistance, and φ is the magnetic flux.

[0108] Specifically, according to the Ampere loop theorem, ∮H·dL=4πNI. Since and since dφ is a constant along the induction tube, it can be taken out of the integral sign, so that

[0109] Wherein, μ is the medium permeability, L is the electromagnet coil length, S is the area perpendicular to the magnetic field direction, B is the magnetic induction intensity, and H is the magnetic field intensity.

[0110] The magnetic flux φ of the entire magnetic circuit is the sum of the magnetic flux dφ of all the magnetic induction tubes. By integrating μdS along a positive cross section of the magnetic circuit and assuming that μ is constant on each positive cross section, we have: ∫μdS=μS. Thus, the magnetic flux expression based on magnetic resistance can be obtained as:

[0111]

[0112] Here, R is the magnetic resistance,

[0113] Further, in one embodiment of the present application, the length of the electromagnetic suspension gap is δ, and a more accurate magnetic resistance expression is obtained, i.e., in one embodiment of the present application, the magnetic resistance is based on the length of the electromagnetic suspension gap δ, and the magnetic resistance is expressed as:

[0114]

[0115] Further, in one embodiment of the present application, it is considered that in practical applications, the permeability μ of the magnetic material is not a constant, and there is a magnetic saturation phenomenon, i.e., the magnetization increases with the increase of the external magnetic field strength in the external magnetic field, and when the magnetization reaches a certain value, even if the external magnetic field strength continues to increase, the magnetization no longer continues to increase. In the magnetic levitation control system, it will be shown that after the electromagnetic current I reaches a certain value, the current and the magnetic resistance continue to increase rapidly, and the magnetic flux φ no longer continues to increase. Assuming that the permeability μ of the unsaturated section is a constant k, in this embodiment of the present application, the magnetic resistance is based on the length of the electromagnetic suspension gap δ and the permeability μ, and the magnetic resistance is expressed as:

[0116]

[0117] Wherein, k is the value of the permeability μ of the unsaturated section, μ is the medium permeability, L is the length of the electromagnetic coil, S is the area perpendicular to the magnetic field direction, and δ is the length of the electromagnetic suspension gap.

[0118] The electromagnetic current I can be used as an observation quantity to judge the magnetic saturation phenomenon, and the magnetic resistance can be expressed as a function R(δ, I) related to the length of the electromagnetic suspension gap δ and the electromagnetic current I. Through finite element analysis of electromagnetic theory, a numerical table of the function can be obtained in advance for table lookup and interpolation during control.

[0119] Therefore, in this embodiment, the magnetic flux expression based on the magnetic resistance is: The following examples also use the magnetic flux expression of this embodiment.

[0120] The formula (18) is upgraded to obtain:

[0121]

[0122] is a partial differential symbol, and d is a differential symbol.

[0123] The differential expression of the magnetic flux is Substituting equation (19) into equation (20), a first-order electromagnet control equation can be obtained, which is a first-order electromagnet control model of the magnetic levitation system and can be expressed as:

[0124]

[0125] Similarly to the foregoing embodiment, when step S102 is performed in this embodiment, a first-order electromagnet control model of the magnetic levitation system can be converted into a state space expression by using a state space equation expression, i.e., equation (20) is reduced to a multi-dimensional first-order system and can be expressed as:

[0126]

[0127] Let It should be noted that A1 and A2 are quantities related only to the structural characteristics of the electromagnet and can be determined in advance by finite element analysis of electromagnetic theory.

[0128] In this embodiment, the total disturbance of the magnetic levitation system can be expressed as:

[0129]

[0130] f unk is the sum of all internal and external disturbances of the magnetic levitation system, the number of turns of the electromagnet coil N and A1 and A2 are known, the magnetic flux φ and the current I can be measured, and thus the part in equation (22) can be regarded as a known quantity and can be written as f k During the controller design process, f k can be fed forwardly compensated.

[0131] Therefore, in one specific embodiment of the present application, the extended state system including the total disturbance of the magnetic levitation system can be expressed as:

[0132]

[0133] Correspondingly, the extended state observer corresponding to the extended state system can be expressed as:

[0134]

[0135] wherein z1 and z2 are state variables of the electromagnet control system, y is the system output, f total is the total disturbance of the magnetic levitation system, is the observed value of the control current of the electromagnet, is the observed value of the magnetic flux, are observed values of the state variables of the electromagnet control system, is the observed value of the system output, and β01 (e) and β 02 (e) are observation gain functions of the extended state observer, e is an error and e = z1-y, f unk is the sum of all internal and external disturbances suffered by the maglev system, A1 and A2 are set parameters, and R e is the equivalent resistance of the electromagnet, and u is the control voltage of the electromagnet.

[0136] As in the foregoing embodiment, in this embodiment, the observation gain functions β 01 (e) and β 02 (e) can adopt a linear form or a nonlinear form.

[0137] The set control quantity can be represented as:

[0138]

[0139] In formula (25), the is brought into formula (24) and simplified, and under the feedback action of the extended state observer, the first-order integral series type maglev system constructed can be represented as:

[0140]

[0141] Similarly, after obtaining the first-order integral series type maglev system, a controller can be designed for the integral series type maglev system by combining classical and modern control methods, such as a PD controller design method, a pole placement method, a nonlinear PID method, and the like, so as to realize feedback control of the maglev gap.

[0142] By applying the technical solution provided in the embodiments of the present application, a maglev system electromagnet control model for representing the relationship between the control voltage of the electromagnet and the magnetic flux can be established, and the maglev system electromagnet control model can be converted into a state space expression by state space equation representation, which facilitates calculation. The total disturbance of the maglev system is taken as a new state variable of the state space expression, an extended state system including the total disturbance of the maglev system is established, an extended state observer of the extended state system is established, the observation gain functions of the extended state observer and the control quantity are set, and an integral series type maglev system for controlling the maglev gap is constructed. It can be seen that, since the total disturbance of the maglev system is taken as a new state variable of the state space expression and the extended state system including the total disturbance of the maglev system is established, the scheme of the present application can compensate for the total disturbance at the control input end, so that the maglev system is converted into a simple integral series type control object, and the accuracy and stability of the control can be effectively improved, and feedback control of the maglev gap can be realized.

[0143] Corresponding to the above method embodiments, the embodiments of the present application also provide a feedback control system of a magnetic levitation gap, which can be mutually corresponding with the above.

[0144] The feedback control system of the magnetic levitation gap can include:

[0145] The electromagnet control model establishing module 201 is configured to establish a magnetic levitation system electromagnet control model for representing a relationship between a control voltage and a magnetic flux of an electromagnet.

[0146] The state space expression establishing module 202 is configured to convert the magnetic levitation system electromagnet control model into a state space expression by a state space equation representation method.

[0147] The extended state system establishing module 203 is configured to establish an extended state system including total disturbance of the magnetic levitation system by taking the total disturbance of the magnetic levitation system as a new state variable of the state space expression.

[0148] The integral series type magnetic levitation system constructing module 204 is configured to establish an extended state observer of the extended state system, and set an observation gain function and a control amount of the extended state observer, so as to construct an integral series type magnetic levitation system for performing magnetic levitation gap control.

[0149] The feedback control executing module 205 is configured to perform feedback control of the magnetic levitation gap based on the integral series type magnetic levitation system.

[0150] It should be noted that, in the present document, the relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or sequence between the entities or operations. Moreover, the terms “include”, “contain” or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitations, the element defined by the statement “including a…” does not exclude the presence of another identical element in the process, method, article or device including the element. The steps of the method or algorithm described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0151] Those skilled in the art will further realize that the mere conception of the examples described herein is sufficient to enable practitioners to practice the examples as changed or modified for specific applications, and that various other modifications or changes in form and detail can be made by those skilled in the art without departing from the spirit and scope of the application. Accordingly, the drawings and descriptions are to be regarded as illustrative in nature and not as restrictive.

[0152] The principles and implementations of the present application have been described in specific examples. The above examples are only used to help understand the technical solutions of the present application and the core ideas thereof. It should be pointed out that, for those skilled in the art, without departing from the principles of the present application, some improvements and modifications can be made to the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

Claims

1. A method of feedback control of a magnetic levitation gap, characterized in that, The method comprises the following steps: establishing a maglev system electromagnet control model for representing the relationship between the control voltage and the magnetic flux of the electromagnet; converting the maglev system electromagnet control model into a state space expression by state space equation representation method; establishing an extended state system including the total disturbance of the maglev system by taking the total disturbance of the maglev system as a new state variable of the state space expression; establishing an extended state observer of the extended state system, and setting the observation gain function and the control quantity of the extended state observer to construct an integral series type maglev system for performing maglev gap control; performing feedback control of the maglev gap based on the integral series type maglev system; The method of establishing a maglev system electromagnet control model for representing the relationship between the control voltage and the magnetic flux of the electromagnet comprises the following steps: establishing a third-order maglev system electromagnet control model for representing the relationship between the control voltage and the magnetic flux of the electromagnet; The method of establishing a third-order maglev system electromagnet control model for representing the relationship between the control voltage and the magnetic flux of the electromagnet comprises the following steps: establishing a maglev system relationship for representing the relationship between the magnetic flux and the electromagnet attraction force; Displacement of an electromagnet relative to a track surface and a track irregularity amount to establish a dynamic equilibrium relationship of the maglev system for representing a motion state of the electromagnet obtaining a third-order electromagnet control equation by upgrading the maglev system dynamic balance relationship and substituting the differential expression of the magnetic flux and the upgraded maglev system relationship, and taking the third-order electromagnet control equation as the established third-order maglev system electromagnet control model; The magnetic levitation system relationship established is expressed as: ; The established dynamic balance relationship of the magnetic levitation system is expressed as: ; The differential expression of the magnetic flux, established according to Faraday's law of electromagnetic induction and Kirchhoff's second law, is expressed as: ; The obtained third-order electromagnet control equation is expressed as: ; wherein, is the suspension force acting on the electromagnet, is the electromagnet attraction force, is the external disturbance excitation, is the magnetic flux, is the vacuum permeability, is twice the electromagnet armature face area, is the electromagnet mass, is time, is the number of turns of the electromagnet induction coil, is the electromagnet control current, is the electromagnet control voltage, is the electromagnet equivalent resistance; The established extended state system including the total disturbance of the maglev system is represented as: ； The established extended state observer of the extended state system is represented as: ； wherein , , , are state variables of the electromagnet control system, y is the system output, is the vacuum permeability, is a set parameter, is the total disturbance of the magnetic levitation system, is the electromagnet control current observation value, is the magnetic flux observation value, , , , are observation values of the state variables of the electromagnet control system, is the observation value of the system output, , , and are observation gain functions of the extended state observer, is an error and .

2. The magnetic levitation gap feedback control method according to claim 1, characterized by, The method of establishing a first-order maglev system electromagnet control model for representing the relationship between the control voltage and the magnetic flux of the electromagnet comprises the following steps: Determining a magnetic flux expression based on a magnetic reluctance ; obtaining a first-order electromagnet control equation by upgrading the magnetic flux expression and substituting the differential expression of the magnetic flux, and taking the first-order electromagnet control equation as the established first-order maglev system electromagnet control model; wherein, N is the number of turns of the electromagnet induction coil, I is the electromagnet control current, R is the magnetic resistance, Φ is the magnetic flux.

3. The magnetic levitation gap feedback control method according to claim 2, characterized by, The magnetic reluctance is based on the length of the gap of the electromagnet levitation and the magnetic reluctance is expressed as ; wherein, is the magnetic permeability of the medium, is the length of the electromagnet coil, is the area perpendicular to the magnetic field direction, is the length of the electromagnet levitation gap.

4. The magnetic levitation gap feedback control method according to claim 2, characterized by, The reluctance is based on the length of the gap of the electromagnet suspension and the magnetic permeability The reluctance is expressed as ; wherein is the permeability of the unsaturated section is the value of the permeability of the medium, is the permeability of the medium, is the length of the electromagnet coil, is the area perpendicular to the direction of the magnetic field, is the length of the electromagnet levitation gap.

5. The magnetic levitation gap feedback control method according to claim 2, characterized by, The established extended state system including the total disturbance of the maglev system is represented as: ； The established extended state observer of the extended state system is represented as: ； wherein, , are state variables of the electromagnet control system, y is the system output, is the total disturbance of the maglev system, is the electromagnet control current observation value, is the magnetic flux observation value, , are observation values of the state variables of the electromagnet control system, is the observation value of the system output, and are observation gain functions of the extended state observer, is the error and , is the sum of all internal and external disturbances suffered by the maglev system, and are set parameters and , is the equivalent resistance of the electromagnet, is the electromagnet control voltage; represents the magnetic flux under the rated load of the electromagnet, represents the reluctance R is a function related to the suspension gap length of the electromagnet and the electromagnet current ; represents the control current observation value under the rated load of the electromagnet.

6. A feedback control system for a magnetic levitation gap, characterized by The method comprises the following steps: An electromagnet control model establishing module is configured to establish a maglev system electromagnet control model for representing the relationship between the control voltage and the magnetic flux of the electromagnet; A state space expression establishing module is configured to convert the maglev system electromagnet control model into a state space expression by state space equation representation method; An extended state system establishing module is configured to establish an extended state system including the total disturbance of the maglev system by taking the total disturbance of the maglev system as a new state variable of the state space expression; An integral series type maglev system constructing module is configured to establish an extended state observer of the extended state system, and set the observation gain function and the control quantity of the extended state observer to construct an integral series type maglev system for performing maglev gap control; A feedback control executing module is configured to perform feedback control of the maglev gap based on the integral series type maglev system; The method of establishing a maglev system electromagnet control model for representing the relationship between the control voltage and the magnetic flux of the electromagnet comprises the following steps: establishing a third-order maglev system electromagnet control model for representing the relationship between the control voltage and the magnetic flux of the electromagnet; establishing a third-order maglev system electromagnet control model for representing the relationship between the control voltage and the magnetic flux of the electromagnet, comprising: establishing a maglev system relationship for representing the relationship between the magnetic flux and the electromagnet suction force; Displacement of an electromagnet relative to a track surface , and a track irregularity amount , a dynamic equilibrium relationship of the maglev system for representing a motion state of the electromagnet is established; deriving a third-order electromagnet control equation by upgrading the maglev system dynamic balance relationship, substituting the differential expression of the magnetic flux and the upgraded maglev system relationship, and taking the third-order electromagnet control equation as the established third-order maglev system electromagnet control model; The magnetic levitation system relationship established is expressed as: ; The established dynamic balance relationship of the magnetic levitation system is expressed as: ; The differential expression of the magnetic flux, established according to Faraday's law of electromagnetic induction and Kirchhoff's second law, is expressed as: ; The obtained third-order electromagnet control equation is expressed as: ; wherein, is the suspension force acting on the electromagnet, is the electromagnet attraction force, is the external disturbance excitation, is the magnetic flux, is the vacuum permeability, is twice the electromagnet armature face area, is the electromagnet mass, is time, is the number of turns of the electromagnet induction coil, is the electromagnet control current, is the electromagnet control voltage, is the electromagnet equivalent resistance; the established expansion state system representation of the maglev system total disturbance is: ； the established expansion state observer of the expansion state system is: ； wherein , , , are state variables of the electromagnet control system, y is the system output, is the vacuum permeability, is a set parameter, is the total disturbance of the magnetic levitation system, is the electromagnet control current observation value, is the magnetic flux observation value, , , , are observation values of the state variables of the electromagnet control system, is the observation value of the system output, , , and are observation gain functions of the extended state observer, is an error and .

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