Magnetic suspension bearing rotor control method, system, equipment, medium and product

Abstract

The invention belongs to the technical field of high-speed electromagnetic bearing systems, and discloses a magnetic suspension bearing rotor control method, system, device, medium and product, and the method comprises the steps: determining an actual adjustable object mathematical model, and selecting a transfer function; selecting a reference model by referring to a controlled object, and selecting a second-order reference model; setting the output of the progressive tracking reference model output by the object as a control target; obtaining an error according to the difference between the output of the reference model and the output of the controlled object; and dynamically adjusting a feedback part output by the closed-loop controller according to the error, and adjusting a feedforward part according to an expected control requirement. According to the method, the accurate reference model is constructed to reflect the dynamic performance of the magnetic suspension electromagnetic bearing system, so that the operation state of the actual system gradually approaches to the reference model, the purpose of improving the stability and the accuracy is achieved, and stable control over the vibration track of the rotor in the magnetic suspension electromagnetic bearing rotor system can be considered.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-speed electro-magnetic bearing systems, and particularly relates to a control method, system, device, medium and product for a magnetic levitation bearing rotor. Background Art

[0002] As an advanced high-tech product, the magnetic levitation electromagnetic bearing has the characteristics of non-contact, frictionless, lubrication-free, long life, high speed, high precision, low noise, etc. However, in practical applications, the stability and precision of the magnetic levitation bearing system are often affected by various factors. For the design of a magnetic levitation electromagnetic bearing system based on model reference adaptive control, the system uses the model reference adaptive (Model Reference Adaptive Control, MRAC) strategy to dynamically adjust the control parameters according to the error signal, so that the operating state of the actual system gradually approaches the reference model. Even when facing external disturbances or uncertainties, it can quickly return to the stable state, thereby achieving the purpose of improving stability and precision. This design not only simplifies the structure of the control device, reduces the computational load, but also improves the real-time performance and precision of the control.

[0003] The Chinese patent publication number is CN115289137A, and the patent application is named "Design and Disturbance Elimination Method of a Linear Active Disturbance Rejection Controller for a Six-Pole Hybrid Magnetic Bearing". The method includes: establishing a suspension force mathematical model for a six-pole radial-axial hybrid magnetic bearing, observing the rotor displacement of the six-pole radial-axial hybrid magnetic bearing through a linear extended state observer to obtain a displacement estimate value, subtracting the given displacement from the displacement estimate value to obtain a displacement error, and then calculating the required suspension current value of the rotor through a linear state error feedback law. The linear extended state observer is used to estimate the acceleration estimate value generated by the disturbing force in real time, and the required suspension current value of the rotor is compensated for disturbance based on the velocity estimate value to obtain a control current after disturbance compensation, so as to eliminate the control current disturbance in the X / Y / Z directions generated by the disturbing force of the magnetic suspension support system, thereby eliminating the control current disturbance generated by the disturbance of the magnetic levitation bearing control system. Although this patent application can also control the magnetic bearing, it cannot well balance the stable control of the rotor vibration trajectory in the magnetic levitation electromagnetic bearing rotor system. Summary of the Invention

[0004] In order to overcome the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a control method, system, device, medium and product for a magnetic levitation bearing rotor. By constructing an accurate reference model to reflect the dynamic performance of the magnetic levitation electromagnetic bearing system, the operating state of the actual system gradually approaches the reference model, thereby achieving the purpose of improving stability and precision, and being able to balance the stable control of the rotor vibration trajectory in the magnetic levitation electromagnetic bearing rotor system.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a control method for a magnetic levitation bearing rotor, comprising the following steps: S1: Establish a differential equation of a four-degree-of-freedom magnetic levitation bearing rotor control system; S2: Independently design closed-loop controllers for four channels of a radial four-degree-of-freedom electromagnetic bearing; select one degree of freedom for analysis, and perform the same processing for other degrees of freedom; S3: Determine the mathematical model of the actually adjustable object, and select a transfer function; select a reference model with reference to the controlled object, and select a second-order reference model: set the output of the object to asymptotically track the output of the reference model as the control target; S4: Obtain an error based on the difference between the output of the reference model and the output of the controlled object; S5: Dynamically adjust the feedback part of the output of the closed-loop controller according to the error, and adjust the feedforward part according to the desired control requirements.

[0006] Optionally, the mathematical model of the actually adjustable object is:

[0007] The selected transfer function is:

[0008] where, x p (t) is the state vector, u(t) is the control input, y p (t) is the output; where: k p is the gain of the controlled object, and k p , a p1 , a po are all constants greater than zero.

[0009] Optionally, the reference model is:

[0010] The transfer function of the reference model is:

[0011] where, x m (t) is the reference state, r(t) is the reference input, y m (t) is the reference output; k m is the gain of the controlled object, and km, am1, am0 are all constants greater than zero.

[0012] Optionally, the output function of the closed-loop controller is:

[0013] Among them, \(K_x(t)\) is the state feedback gain matrix for adjusting the system state \(x(t)\); \(K_r(t)\) is the reference input gain matrix for adjusting the reference input \(r(t)\).

[0014] Optionally, after step S5, a model reference adaptive controller for the magnetic levitation bearing rotor control system is established and its dynamic performance is verified.

[0015] Optionally, in step S2, when independently designing the closed-loop controllers for four channels of the radial four-degree-of-freedom electromagnetic bearing, the influence of the rotor axial bearing is ignored.

[0016] In a second aspect, the present invention provides a magnetic levitation bearing rotor control system, including: a control system establishment module for establishing a differential equation of the four-degree-of-freedom magnetic levitation bearing rotor control system; A closed-loop controller design module for independently designing closed-loop controllers for four channels of the radial four-degree-of-freedom electromagnetic bearing; selecting one degree of freedom for analysis and performing the same processing for other degrees of freedom; A model selection module for determining the mathematical model of the actual adjustable object and selecting a transfer function; selecting a reference model with reference to the controlled object, and selecting a second-order reference model: setting the output of the object to asymptotically track the output of the reference model as the control target; An error calculation module for obtaining an error based on the difference between the output of the reference model and the output of the controlled object; An adjustment module for dynamically adjusting the feedback part of the output of the closed-loop controller according to the error and adjusting the feedforward part according to the desired control requirements.

[0017] In a third aspect, the present invention provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, and when the processor executes the computer program, the magnetic levitation bearing rotor control method is implemented.

[0018] In a fourth aspect, the present invention provides a computer-readable storage medium, where the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the magnetic levitation bearing rotor control method is implemented.

[0019] In a fifth aspect, the present invention provides a computer program product including a computer-readable medium, and computer-readable program code is included on the computer-readable medium, and the program code executes the magnetic levitation bearing rotor control method.

[0020] Compared with the prior art, the present invention has the following beneficial effects: The present invention constructs an accurate reference model to reflect the dynamic characteristics of the magnetic levitation electromagnetic bearing system and further optimizes it, taking into account the stable control of the rotor vibration trajectory in the magnetic levitation electromagnetic bearing rotor system.

[0021] First, an accurate reference model is constructed, which can accurately reflect the dynamic characteristics and behavior of the magnetic levitation bearing system. By real-time monitoring the operating state of the actual system and comparing it with the reference model, the error of the system can be calculated. Then, according to the error signal, the control parameters can be dynamically adjusted, so that the operating state of the actual system gradually approaches the reference model, thereby achieving the purpose of improving stability and accuracy. The present invention not only simplifies the structure of the control device, reduces the computational amount, but also improves the real-time performance and accuracy of the control.

[0022] Furthermore, the present invention can not only ensure the stability of the closed-loop system, but also resist the changes of system parameters and external disturbances. First, the magnetic levitation electromagnetic bearing rotor system realizes the suspension and stable control of the rotor through electromagnetic force. In this process, the state information such as the position and speed of the rotor needs to be real-time monitored by sensors and fed back to the controller. However, due to factors such as the nonlinearity of electromagnetic force, the change of the gap between the rotor and the stator, and external disturbances, traditional fixed-parameter controllers often have difficulty in achieving precise control of the rotor system.

[0023] The method of the present invention first establishes an accurate mathematical model of the electromagnetic bearing rotor system, including the calculation of electromagnetic force, the description of rotor dynamic characteristics, and the design of the controller. This reference model generates an ideal rotor position output trajectory according to the input signal (such as current command), and compares it with the rotor displacement output of the reference model. When there is a difference between the actual output and the reference model output, adjustment instructions are generated according to the error signal, and these instructions are converted into actual current changes in the electromagnetic bearing through a power amplifier. The change of current then changes the magnitude and direction of the electromagnetic force, thereby achieving precise control of the rotor position and speed. Through continuous adaptive adjustment, including the determination of controller gain and adaptive speed key parameters, the actual output of the magnetic levitation electromagnetic bearing rotor system can gradually approach or even equal the output of the reference model, thereby realizing the stable suspension and precise control of the rotor. This adaptive control strategy not only improves the control accuracy and stability of the system, but also enhances the robustness of the system to external disturbances and parameter changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings described herein are for illustrative purposes only and are not intended to limit the scope of the disclosure of the present invention in any way.

[0025] In the drawings: Figure 1 is a schematic diagram of the magnetic levitation bearing rotor; Figure 2 is a block diagram of the model reference adaptive control system structure; Figure 3 is a rigid rotor system model; Figure 4 It is a principle block diagram of an electromagnetic bearing system based on model reference adaptive control; Figure 5 It is a flowchart of a model reference adaptive control algorithm; Figure 6 It is the vibration trajectory of a single-degree-of-freedom magnetic levitation system; Figure 7 It is a simulation result diagram of the step response curves in the xA direction with four degrees of freedom for a PID controller and an MRAC controller. Detailed implementation manners

[0026] In order to enable those skilled in the art of the present technology to better understand the technical solutions in the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the present invention.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the description of the present invention herein are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0028] It should be noted that in the claims, any reference signs placed between parentheses shall not be construed as limiting the claims. The word "comprising" does not exclude the presence of components or steps not listed in the claims. The word "a" or "an" preceding a component does not exclude the presence of a plurality of such components. The present application can be implemented by means of hardware including several different components and by means of a properly programmed computer. In the unit claims listing several devices, several of these devices can be embodied by the same hardware item. The use of the words first, second, and third, etc. does not denote any order. These words can be interpreted as names. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more unless otherwise specifically defined. The present invention will be described in detail below in conjunction with the accompanying drawings.

[0029] As Figure 1As shown in the figure, a control method for a magnetic levitation bearing rotor of the present invention includes the following steps: S1: Establish the differential equation of the magnetic levitation bearing rotor control system with four degrees of freedom; S2: Independently design closed-loop controllers for four channels of the radial four-degree-of-freedom electromagnetic bearing; Select one degree of freedom for analysis, and perform the same processing for other degrees of freedom; The schematic diagram of the single-degree-of-freedom active magnetic levitation control system is shown in the figure.

[0030] Design the reference adaptive control law of the system model: S3: Determine the mathematical model of the actually adjustable object, and select the transfer function; Select the reference model with reference to the controlled object, and select the second-order reference model: Set the output of the object to asymptotically track the output of the reference model as the control target; S4: Obtain the error based on the difference between the output of the reference model and the output of the controlled object; S5: Dynamically adjust the feedback part of the output of the closed-loop controller according to the error, and adjust the feed-forward part according to the desired control requirements.

[0031] The key role of the adaptive law module is to achieve rapid convergence of parameter estimation on the basis of system stability, gradually adjust the error, which is crucial for maintaining system stability and ensuring the convergence of the control system. The design method based on Lyapunov stability theory is adopted, and this theory aims to ensure that the adaptive control system has Lyapunov stability by designing the system state equation, thereby improving the performance and robustness of the control system.

[0032] Mathematical model of the actually adjustable object:

[0033] Among them, x p (t) is the state vector, u(t) is the control input, and y p (t) is the output.

[0034] The transfer function is:

[0035] Among them: k p is the gain of the controlled object, and k p , a p1 , a po are all constants greater than zero.

[0036] Select the reference model with reference to the controlled object, and select the second-order reference model:

[0037] Among them, x m(t) is the reference state, r(t) is the reference input, and y m (t) is the reference output.

[0038] The transfer function is:

[0039] where: k m is the gain of the controlled object, and km, am1, and am0 are all constants greater than zero.

[0040] The control objective is to design the control action u(t) such that the output yp(t) of the object can asymptotically track the output ym(t) of the reference model, and all signals of the system are bounded throughout the control process.

[0041] For the electromagnetic bearing rotor system, assuming the output of the reference model is xm and the output of the controlled object is x, the error e can be expressed as: e = xm - x The design of the adaptive law is based on this error e to adjust the parameters of the controller.

[0042] The controller output u(t) consists of a feedback part and a feedforward part. The feedback part is dynamically adjusted according to the error, and the feedforward part is adjusted according to the desired control requirements.

[0043] The output of the controller is:

[0044] where Kx(t) is the state feedback gain matrix used to adjust the system state x(t); Kr(t) is the reference input gain matrix used to adjust the reference input r(t). By adjusting Kx(t) and Kr(t), the controller can be adjusted in real time to reduce the error.

[0045] Build a model reference adaptive controller for the magnetic levitation bearing rotor control system and verify its dynamic performance.

[0046] The adaptive law is designed through Lyapunov stability theory to ensure that the error converges to zero and is in the form of:

[0047] where, and are positive definite gain matrices.

[0048] Verify the system stability through the Lyapunov function:

[0049] where P is a positive definite matrix, .

[0050] The convergence of the adaptive gains Kx(t) and Kr(t) depends on the persistent excitation conditions of the reference input r(t) and the system state x(t). If r(t) and x(t) satisfy the persistent excitation conditions, then Kx(t) and Kr(t) will converge to the ideal values.

[0051] This control structure is designed when the model state variables are measurable. The adjustable system is formed by using the existing parameter-adjustable state feedback control Kx and the feedforward control Kr. As shown in the figure, by analyzing the error e(t), the change of the error over time is analyzed, and it is proved that under the action of the adaptive mechanism control algorithm, the system can gradually converge to zero error.

[0052] Embodiment 1 Step 1: The magnetic levitation rotor system usually consists of two radial bearings and one axial bearing. The schematic diagram of the magnetic levitation bearing rotor is as Figure 1 shown.

[0053] Let the central planes of the two ends AMBs-A and AMBs-B be Π A and Π B . The center of mass of the balanced rotor is C . Due to symmetry, the center of mass C must be located on the geometric center line of the rotor. Pass through the point and make a plane A parallel to the central planes Π B of the two ends AMBs . The plane intersects the geometric center line of the stator at point. The distances from the A point to the central planes Π B of the two ends AMBs are l a and l b respectively. The distance between the planes Π A and Π B is . Establish a Oxyz fixed coordinate system, where the z axis is the rotation axis, and a right-handed system is formed among x , y and z . Then the motion state of the rotor can be represented by the translational displacements of the rotor center of mass in the x and y directions ([[]] x , y ) and the angular displacements of the rotor around the x and y axes ([[]] θ x , θy ) is described as follows.

[0054] Considering the influence of rotor imbalance, the differential equation of the four-degree-of-freedom magnetic levitation bearing rotor control system is obtained as follows:

[0055] In the formula, m is the rotor mass; J Z and J are the moments of inertia of the rotor about the Z axis and the x axis and y axis respectively; m e and ε are the unbalanced mass and the eccentricity respectively; f xa , f ya , f xb , f yb are the electromagnetic forces of the two AMBs in the x and y directions respectively; the distances between the centroid of the balanced rotor and the center planes of the electromagnetic bearings at both ends are l a and l b respectively; the translational displacements (x, y) of the rotor centroid in the x-axis direction and y-axis direction are described by the angular displacements (θ x , θ y ) of the rotor about the x and y axes; the transient rotation angle of the unbalanced centroid is ϕ.

[0056] Step 2: Ignoring the influence of the rotor axial bearing, the four-degree-of-freedom radial electromagnetic bearing can independently design the closed-loop controllers for four channels. Since the mathematical model structures of each degree of freedom are the same but the parameters are different, one degree of freedom can be selected for analysis, and the same treatment is done for other degrees of freedom.

[0057] Select the x a direction of the radial bearing A as the research object. The controlled object is a second-order linear time-invariant system, and its state equation is:

[0058] Its transfer function is:

[0059] Among them: k p is the gain of the controlled object, Y p (s)=1, k p , a p1 , a po are all constants greater than zero and are selected according to the system transfer function. is the state variable of the b controlled object; is the output signal of the controlled object system; is the coefficient matrix of the controlled object; is the coefficient matrix of the input variable of the controlled object; is the coefficient matrix; is the input signal of the controlled object system. P is the transfer function of the controlled object; Y and U are Hurwitz polynomials with the leading coefficient being 1; Kp is the positive gain of the controlled object.

[0060] Select a reference model with reference to the controlled object. The selected second-order reference model is:

[0061] The transfer function is:

[0062] where: k m is the gain of the controlled object, Y m (s) = 1, k m , a m1 , a mo are all constants greater than zero, selected according to the system transfer function. is the state variable of the reference model; is the output signal of the reference model system; is the coefficient matrix of the reference model; is the coefficient matrix of the input variable of the reference model; is the coefficient matrix; is the input signal of the reference model system. M is the transfer function of the reference model; Y and R are Hurwitz polynomials with the leading coefficient being 1; km is the positive gain of the reference model.

[0063] Since the relative orders of the controlled object and the reference model are both 2, M(s) is not positive real. To ensure that M(s) is strictly positive real, a polynomial L(s) is introduced to make L(s)M(s) strictly positive real.

[0064] L(s) is a first-order stable polynomial, taken as: L(s) = s + a = s + 5 where: L is the polynomial; S is the complex frequency variable; a is the adjustable constant; 0 < a < a m1 ; a m1 is the first-order term coefficient of the denominator of M(s).

[0065] The corresponding block diagram of the model reference adaptive control system is as Figure 2 shown.

[0066] Figure 2 In it, P(s) and M(s) are the controlled object and the reference model respectively, y r , y p , y m are the reference input, the output of the controlled object, and the output of the reference model of the system respectively, u is the input of the controlled object, e mis the adaptive control error, k0, c T , d0 and d T are adjustable parameters, η(t) = [k0(t), c T (t), d0(t), d T (t)], S is the complex frequency variable, F1 and F2 are auxiliary signal generators, and their transfer functions are expressed as:

[0067]

[0068] Among them, c1, d0, d1 are adjustable parameters, s is the variable, a is a constant, and a = 5 is taken From the system block diagram, the input signal u is expressed as:

[0069] Among them, is the signal vector, are the state variables of the auxiliary signal generator respectively, is the adjustable parameter vector, is the adaptive law used to compensate for the system uncertainty.

[0070] Step 3: Specific design of the model reference adaptive control law.

[0071] From Figure 2 , the input-output transfer function of the adjustable system is:

[0072] Among them, y r , y p are the reference input of the system and the output of the controlled object respectively.

[0073]

[0074]

[0075]

[0076] Among them, k0, d0 are adjustable parameters, is the output of the auxiliary signal generator module F1, is the output of the auxiliary signal generator module F2, Auxiliary generator, polynomial L(s) = s + a.

[0077] Then the input-output transfer function of the system is expressed as:

[0078] Among them, is the system adjustable parameter vector, kp is the gain of the controlled object, km is the gain of the reference model, Yp(s) and Rp(s) are the nth and mth monic polynomials of the controlled object respectively, Ym(s) and Rm(s) are the nth and mth monic polynomials of the reference model respectively, is the output of the auxiliary signal generator module F1, is the output of the auxiliary signal generator module F2, Auxiliary generator, polynomial L(s)=s+a.

[0079] Then the adaptive law , where is the displacement error, R is a diagonal positive definite matrix

[0080]

[0081] where is the signal vector.

[0082] From the system gain k p <0 After derivation, the adaptive law of the system can be obtained as:

[0083] From the system transfer function, it can be obtained that:

[0084] kp is the gain of the controlled object, km is the gain of the reference model; then

[0085] Step 4: Build a four-degree-of-freedom magnetic levitation bearing rotor control system model according to the differential equation in Step 1. As Figure 3 shown, it is a rigid rotor system model. It can be seen that the magnetic levitation bearing rotor control system has mutual coupling.

[0086] The coupling relationship of the radial four degrees of freedom can be expressed by a complete mathematical model. The mathematical model structures of each degree of freedom are the same but the parameters are different. Therefore, one degree of freedom is selected for analysis, and the other degrees of freedom can be processed similarly.

[0087] Figure 4 is the principle block diagram of the electromagnetic bearing system based on model reference adaptive. y r , y p are the reference input, the output of the controlled object, y m is the output of the reference model, e is the system error, and e m is the adaptive control error.

[0088] Rx is the reference input, x is the displacement signal collected by the displacement sensor, U0 is the control signal output by the controller, I0 is the bias current, fx is the suction force of the electromagnet on the rotor, ix is the current change value caused by the change of the electromagnetic force of the electromagnet, and x is the distance that the rotor deviates from the equilibrium position due to the disturbance.

[0089] In the field of electromagnetic bearing control, MRAC has the ability to automatically adjust and correct the stable operation of the rotor, and can quickly and effectively readjust when the working environment or parameters of the high-speed motor change, so that the rotor returns to the ideal working state.

[0090] The core of the MRAC system consists of a reference model, an adjustable model and an adaptive law. The reference model represents the actual operation of the electromagnetic bearing rotor system, which is usually constructed from the dynamic equation of the electromagnetic bearing rotor system and receives the voltage signal given by the controller as input. The adjustable model is obtained by transforming the mathematical model of the bearing rotor system, and is a model for estimating the rotor state according to the displacement signal collected by the actual rotor system, including the parameters to be identified. The system compares the error between the reference model and the adjustable model, and adjusts through the adaptive law to make the steady-state error between the two approach zero. When the difference between the reference model and the adjustable model is zero, it can be considered that the adjustable model has approached the reference model, and the identified parameters also match the actual values.

[0091] Select the rotor mass m = 18.09 kg, the power amplifier gain K a = 1 A / V, the current stiffness coefficient K i = 321.09 N / A, the displacement stiffness coefficient K y = 8.476×10 5 N / m.

[0092] Input-output transfer function of the active electromagnetic bearing:

[0093] Among them, k p > 0, a p1 > 0, a p0 > 0. k p , a p1 , a po are all constants greater than zero.

[0094] In the formula: , ,

[0095] Select the desired system input-output transfer function:

[0096] M(s) is selected as a stable minimum-phase system, having the same order and relative degree as P(s), and also having ideal dynamic performance.

[0097] According to the control requirements, a system model reference adaptive control algorithm flowchart is designed, as Figure 5 shown. By calculation, corresponding set parameters are selected, so as to obtain the control law parameters η(t) = [k0(t), c T (t), d0(t), d T (t)] in the model reference adaptive control, and drive the adaptive regulator to adjust the controller parameters to reduce the system error and make the output of the controlled object reach the desired output.

[0098] Example 2 To clearly demonstrate the control effect of the model reference adaptive control on the rotor stability, a classical PID control method is selected for comparison. The PID controller parameters P, I, and D are selected as 9000, 10000, and 2 respectively, Figure 6 The rotor displacement responses under the two control strategies are given. It is usually seen that the model reference adaptive controller (MRAC) can achieve a shorter steady-state time, that is, the time required for the system to reach the steady state is faster than that of the PID control. This is because the MRAC can more effectively adjust the control strategy according to the real-time performance of the system, so as to optimize the response. The MRAC can usually reduce the overshoot and make the system more stable at the steady state. On the contrary, the overshoot of the PID control is larger.

[0099] As Figure 7 shown, through the actual simulation data, the advantages of the MRAC controller in the four-degree-of-freedom electromagnetic bearing rotor system can be intuitively seen. Since the PID is based on fixed control parameters, it cannot adapt to the changes of the system and external disturbances, which may lead to a decrease in the system control accuracy and inability to reach the desired accuracy. The MRAC controller can minimize the steady-state error by adjusting the control parameters in real time. Especially in the four-degree-of-freedom system, due to its adaptive characteristics, it can effectively handle the system dynamic changes and eliminate the steady-state error. The MRAC can dynamically adjust the output to make the rotor centroid stay at the desired position as accurately as possible and eliminate the steady-state deviation in the system.

[0100] Example 3 Based on the magnetic levitation bearing rotor control method of Example 1, a magnetic levitation bearing rotor control system is disclosed, including: a control system establishment module for establishing a differential equation of the four-degree-of-freedom magnetic levitation bearing rotor control system; a closed-loop controller design module for independently designing four-channel closed-loop controllers for the radial four-degree-of-freedom electromagnetic bearings; select one degree of freedom for analysis, and the same treatment is done for other degrees of freedom; A model selection module, which is used to determine the mathematical model of the actual adjustable object and select a transfer function; select a reference model with reference to the controlled object, and select a second-order reference model; set the output of the object to asymptotically track the output of the reference model as the control objective. An error calculation module, which is used to obtain an error according to the difference between the output of the reference model and the output of the controlled object. An adjustment module, which is used to dynamically adjust the feedback part of the output of the closed-loop controller according to the error, and adjust the feedforward part according to the desired control requirements.

[0101] Embodiment 4 The purpose of this embodiment is to provide an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the magnetic levitation bearing rotor control method is implemented.

[0102] Embodiment 5 The purpose of this embodiment is to provide a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the magnetic levitation bearing rotor control method is implemented.

[0103] Embodiment 6 The purpose of this embodiment is to provide a computer program product including a computer-readable medium, on which computer-readable program code is included, and the program code implements the magnetic levitation bearing rotor control method.

[0104] The steps involved in the devices in the above Embodiments 3, 4, 5, and 6 correspond to those in Method Embodiment 1. For specific implementation manners, reference may be made to the relevant description part of Embodiment 1.

[0105] Those skilled in the art in this technical field should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memories, CD-ROMs, optical memories, etc.) containing computer-usable program code. This application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram, as well as the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the functions specified in one or more flows Figure 1 one or more flows and / or blocks Figure 1 or in one or more blocks. These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device that implements the functions specified in one or more flows Figure 1 one or more flows and / or blocks Figure 1 or in one or more blocks. These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more flows Figure 1 one or more flows and / or blocks Figure 1 or in one or more blocks.

[0106] In the above embodiments, the working methods or control methods involved, unless otherwise specified, are all conventional working methods or control methods in this field.

[0107] Although the preferred embodiments of the present application have been described, those skilled in the art can make additional changes and modifications once they learn the basic creative concepts. Therefore, the appended claims are intended to be construed as including the preferred embodiments and all changes and modifications falling within the scope of the present application. Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Other modifications or equivalent replacements made by those of ordinary skill in the art to the technical solutions of the present invention should be covered within the scope of the claims of the present invention as long as they do not depart from the spirit and scope of the technical solutions of the present invention.

Claims

1. A control method for a magnetic levitation bearing rotor, characterized in that, It includes the following steps: S1: Establish the differential equation of the magnetic levitation bearing rotor control system with four degrees of freedom; S2: Independently design closed-loop controllers for four channels of the radial electromagnetic bearing with four degrees of freedom; select one degree of freedom for analysis, and perform the same treatment for other degrees of freedom; S3: Determine the mathematical model of the actual adjustable object, and select the transfer function; select the reference model with reference to the controlled object, and select the second-order reference model: set the output of the object to asymptotically track the output of the reference model as the control target; S4: Obtain the error based on the difference between the output of the reference model and the output of the controlled object; S5: Dynamically adjust the feedback part of the output of the closed-loop controller according to the error, and adjust the feedforward part according to the desired control requirements.

2. A magnetic levitation bearing rotor control method according to claim 1, characterized in that the mathematical model of the actual adjustable object is: the selected transfer function is: where x p (t) is the state vector, u(t) is the control input, and y p (t) is the output; where: k p is the gain of the controlled plant, and k p , a p1 , a po are all constants greater than zero.

3. A method for controlling a magnetic levitation bearing rotor according to claim 1, characterized in that, the reference model is: the transfer function of the reference model is: where x m (t) is the reference state, r(t) is the reference input, y m (t) is the reference output; k m is the gain of the controlled plant, and km, am1, and am0 are all constants greater than zero.

4. A method for controlling a magnetic levitation bearing rotor according to claim 1, characterized in that, The output function of the closed-loop controller is as follows: where, Kx(t) is the state feedback gain matrix for adjusting the system state x(t); Kr(t) is the reference input gain matrix for adjusting the reference input r(t).

5. A magnetic levitation bearing rotor control method according to claim 1, characterized in that After step S5, establish a model reference adaptive controller for the magnetic levitation bearing rotor control system and verify its dynamic performance.

6. A method for controlling a magnetic levitation bearing rotor according to claim 1, characterized in that, In step S2, when independently designing closed-loop controllers for four channels of the radial electromagnetic bearing with four degrees of freedom, the influence of the rotor axial bearing is ignored.

7. A magnetic levitation bearing rotor control system, characterized in that It includes: A control system establishment module for establishing the differential equation of the magnetic levitation bearing rotor control system with four degrees of freedom; A closed-loop controller design module for independently designing closed-loop controllers for four channels of the radial electromagnetic bearing with four degrees of freedom; selecting one degree of freedom for analysis, and performing the same treatment for other degrees of freedom; A model selection module for determining the mathematical model of the actual adjustable object and selecting the transfer function; Selecting the reference model with reference to the controlled object, and selecting the second-order reference model: setting the output of the object to asymptotically track the output of the reference model as the control target; An error calculation module for obtaining the error based on the difference between the output of the reference model and the output of the controlled object; An adjustment module for dynamically adjusting the feedback part of the output of the closed-loop controller according to the error, and adjusting the feedforward part according to the desired control requirements.

8. An electronic device, characterized in that, It includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the magnetic levitation bearing rotor control method according to any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, and when the computer program is executed by the processor, it implements the magnetic levitation bearing rotor control method according to any one of claims 1-6.

10. A computer program product comprising a computer-readable medium, characterized in that, On the computer-readable medium, there is included computer-readable program code, and the program code executes the magnetic levitation bearing rotor control method according to any one of claims 1-6.

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