CN-121980898-A - Bearing rotor position and attitude prediction and calculation method excited by actuating unit

CN121980898ACN 121980898 ACN121980898 ACN 121980898ACN-121980898-A

Abstract

The invention relates to a method for predicting and resolving the position and the attitude of a bearing rotor excited by an actuating unit, which takes the solution of an air film mechanical value as a physical basis, combines a multi-input multi-output neural network to construct a prediction model, uses indexes such as complex correlation coefficients and the like to verify the precision of the prediction model on a testing set, can rapidly predict and reversely solve the parameters of the actuating unit, thereby realizing the rapid and reversely solving of the position and the attitude of the rotor, further dynamically adjusting the distribution of an air film pressure field by ‌ to change the excitation parameters ‌ of the actuating unit, realizing the active regulation and control of the position and the attitude of the rotor, remarkably reducing the time delay, improving the control instantaneity and the stability, covering various bearings and different actuating excitation modes, taking account of solving speed, application range and convenience, and having higher practical value.

Inventors

GAO FENWU
LI WENJUN
FENG KAI
SUN JIANYONG
ZHANG PENGFEI

Assignees

洛阳轴承研究所有限公司

Dates

Publication Date: 20260505
Application Date: 20251128

Claims (10)

1. The method for predicting and resolving the position and the attitude of a rotor of a bearing excited by an actuating unit is characterized in that the bearing is excited by the actuating unit to form a gas film between the rotor and establish a pressure field, and the position and the attitude of the rotor are actively regulated and controlled by changing excitation parameters of the actuating unit, and the method for predicting and resolving the position and the attitude is characterized by comprising the following steps: s1, modeling and dimensionless, namely establishing a relation between a geometric model of a bearing structure and the thickness of a gas film, and deducing a dimensionless Reynolds equation suitable for the bearing structure, wherein the thickness of the gas film comprises a static position item and a dynamic deformation item; s2, dispersing and iteration solving, namely dispersing the dimensionless Reynolds equation by adopting a finite difference or equivalent format, and carrying out nonlinear iteration on the discrete equation to obtain a pressure field; s3, solving the position and the posture, namely calculating the bearing capacity and the rotation moment of a bearing rotor based on the pressure field distribution of the bearing, and solving the static balance position and the posture of the rotor according to a balance criterion; S4, sampling and data construction, namely selecting a target point in a working area where a bearing rotor can reach, sampling to generate a data set about 'actuating unit parameters-rotor position and posture', and dividing the data set into a training set and a testing set; s5, training and verifying a prediction model by adopting a multi-input multi-output neural network, and verifying model accuracy on a test set; S6, applying the trained and verified prediction model to rapidly and reversely solve corresponding actuating unit parameters according to the position and the posture of the rotor to realize active track control of the air bearing.
2. The method for predicting and resolving the position and the attitude of a rotor of a bearing excited by an actuating unit according to claim 1, wherein the bearing type is at least one of a radial bearing or a thrust bearing, and the bearing is in the form of at least one of annular actuation, segmented multi-unit, tilting pad, conical surface or spherical surface or any combination thereof, and the number of units of the segmented multi-unit is more than or equal to 3.
3. A method of predicting and resolving the position and attitude of a rotor in a bearing excited by an actuator unit according to claim 2, wherein in step S1, the dimensionless reynolds equation for the radial bearing at (θ, Z) is: ; In the middle of In the case of a circumferential angle of the ring, As the axial coordinate of the two-dimensional coordinate system, In the case of a time-varying term, Is the pressure of the non-dimensional air film, The thickness of the non-dimensional air film is set as a non-dimensional time; the non-dimensional Reynolds equation for the thrust bearing at (R, θ) is: ; Wherein R is a radial coordinate of the compound, In the case of a circumferential angle of the ring, In the case of a time-varying term, The pressure of the non-dimensional air film, Is the thickness of the dimensionless air film, T is the dimensionless time.
4. The method for predicting and resolving the position and attitude of a rotor of a bearing excited by an actuating unit according to claim 1, wherein in step S1, the dynamic deformation term is deformed by a bearing structure under the influence of the actuating unit excitation, and the thickness of the air film is summarized as: ; wherein r is the polar diameter, The polar angle is the polar angle, t is the time, H s is a static position term, H d is a dynamic deformation term, and the dynamic deformation is obtained according to the mode shape fitting of the bearing.
5. The method for predicting and resolving the position and the attitude of a bearing rotor excited by an actuating unit according to claim 1, wherein in the step S2, nonlinear iteration adopts a Newton-Raphson method, a Gauss-Seidel method or an ultra-relaxation iteration method, and the convergence condition is that the pressure difference and the position and attitude difference under the adjacent iteration times are smaller than a threshold value, and the deviation between the air film bearing and the external load is smaller than the threshold value.
6. The method for predicting and resolving the position and the attitude of a rotor of a bearing excited by an actuating unit according to claim 1, wherein in the step S3, the static equilibrium position and the attitude of the rotor are determined by integrating the pressure into a tile air film force and decomposing the tile air film force to the respective degrees of freedom, solving the attitude correction by using a simultaneous bearing stiffness model, and then using the periodic average levitation force and the moment and the external load and the moment as criteria.
7. The method according to claim 1, wherein in step S4, the target point is selected by regular grid sampling, latin hypercube sampling or a combination thereof.
8. The method according to claim 1, wherein in step S4, the data in the data set is divided into a training set and a test set after the data in the data set is normalized and normalized in the input and output dimensions.
9. The method according to claim 1, wherein in step S5, the mimo neural network includes an input layer, a hidden layer and an output layer, wherein the input parameters of the input layer are rotor position and attitude, and the output parameters of the output layer are actuator parameters.
10. The method for predicting and resolving the position and orientation of a rotor in a bearing excited by an actuator unit according to claim 1, wherein in step S5, the accuracy of the prediction model is measured based on complex correlation coefficients, the complex correlation coefficients being calculated as Calculating, wherein n is the number of samples in the test set, Representing the actual observations of the ith sample in the test set, Representing the predicted value of the i-th sample in the test set, Representing the actual observed mean of all samples in the test set, and considering that the model meets the accuracy requirement if the complex correlation coefficient of the test set is > 0.95.

Description

Bearing rotor position and attitude prediction and calculation method excited by actuating unit Technical Field The invention relates to the technical field of non-contact support and precision bearings, in particular to a method for predicting and resolving the position and the attitude of a bearing rotor excited by an actuating unit. Background The air film/air bearing has small friction and high cleanliness, the bearing forms a micron-sized air film between the rotors by the excitation of the actuating units and establishes a pressure field, the position and the posture of the rotors are actively regulated and controlled by changing the excitation parameters of the actuating units, the air film/air bearing is widely used for high-cleanliness transportation, precise positioning and high-speed rotation scenes, and the position and the posture of the rotors of the bearing are coupled by multiple factors, such as the amplitude, the air film gap, the load and the like of the actuating units, and the characteristics of strong nonlinearity and strong coupling are presented. The existing solving path for the rotor position and posture of the bearing mainly comprises two types, namely, directly solving a Reynolds equation in numerical value, calculating the air film pressure and bearing when each working condition parameter, and then gradually and iteratively searching the rotor position and posture meeting the force/moment balance. Therefore, a bearing rotor position and attitude quick solving algorithm with wide application range and ensured physical consistency and precision constraint is needed to meet the requirements of quick solving and real-time control of the rotor track of the air floatation/air film bearing. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a method for predicting and resolving the position and the attitude of a bearing rotor excited by an actuating unit, which takes the gas film mechanical numerical solution as a physical basis and combines a multi-input multi-output neural network to construct a prediction model, thereby realizing the rapid inverse solution of the position and the attitude of the rotor, remarkably reducing the time delay, improving the control instantaneity and the stability, covering various bearings and different actuating excitation modes, and taking the solving speed, the application range and the convenience into consideration. In order to achieve the aim, the technical scheme adopted by the invention is that the method for predicting and resolving the position and the attitude of the rotor of the bearing excited by the actuating unit comprises the following steps of: s1, modeling and dimensionless, namely establishing a relation between a geometric model of a bearing structure and the thickness of a gas film, and deducing a dimensionless Reynolds equation suitable for the bearing structure, wherein the thickness of the gas film comprises a static position item and a dynamic deformation item; s2, dispersing and iteration solving, namely dispersing the dimensionless Reynolds equation by adopting a finite difference or equivalent format, and carrying out nonlinear iteration on the discrete equation to obtain a pressure field; s3, solving the position and the posture, namely calculating the bearing capacity and the rotation moment of a bearing rotor based on the pressure field distribution of the bearing, and solving the static balance position and the posture of the rotor according to a balance criterion; S4, sampling and data construction, namely selecting a target point in a working area where a bearing rotor can reach, sampling to generate a data set about 'actuating unit parameters-rotor position and posture', and dividing the data set into a training set and a testing set; s5, training and verifying a prediction model by adopting a multi-input multi-output neural network, and verifying model accuracy on a test set; S6, applying the trained and verified prediction model to rapidly and reversely solve corresponding actuating unit parameters according to the position and the posture of the rotor to realize active track control of the air bearing. Further, the bearing type is at least one of a radial bearing or a thrust bearing, the structural form of the bearing is at least one of annular actuation, segmented multi-unit, tilting pad, conical surface or spherical surface or any combination, and the number of the segmented multi-unit units is more than or equal to 3. A method of predicting and resolving the position and attitude of a rotor in a bearing excited by an actuator unit according to claim 2, wherein in step S1, the dimensionless reynolds equation for the radial bearing at (θ, Z) is: ; In the middle of In the case of a circumferential angle of the ring,As the axial coordinate of the two-dimensional coordinate system,In the case of a time-varying term,Is the pressure of the non-dimensional air film,The thickness of the