WO2022183468A1

WO2022183468A1 - Control method for turntable with six-degrees-of-freedom adjustment

Info

Publication number: WO2022183468A1
Application number: PCT/CN2021/079242
Authority: WO
Inventors: 毕然; 周烽; 王辉; 王丽萍; 金春水
Original assignee: 中国科学院长春光学精密机械与物理研究所
Priority date: 2021-03-05
Filing date: 2021-03-05
Publication date: 2022-09-09

Abstract

A control method for a turntable with six-degrees-of-freedom adjustment, comprising: dividing the turntable with six-degrees-of-freedom adjustment into mechanical parts for harmonic response analysis in order to acquire N groups of frequency response data under different inputs, performing systematic identification on a group of frequency response data, and establishing a set of first transfer function models of different order-zero number combinations; performing systematic identification on the N groups of frequency response data, and selecting a preferred transfer function model from a set of second transfer function models as a mechanical transfer function model; setting a preset order and preset zero number of an electrical part, performing systematic identification on a plurality of preset signals, and establishing a set of third transfer function models of a preset order and preset zero number and an electrical transfer function model; acquiring and controlling a control parameter of a motor controller on the basis of an overall transfer function, and controlling the motor controller to control the operation of the turntable on the basis of the control parameter. The present invention can achieve accurate control of a complex system.

Description

A control method for adjusting turntable with six degrees of freedom

technical field

The invention relates to the technical field of system identification, and more particularly, to a control method for adjusting a turntable with six degrees of freedom.

Background technique

The main process of the existing traditional system identification technology is: design identification experiments according to the identification purpose and prior knowledge of the system, after acquiring the input/output data, preprocess the data, and then determine the model according to the prior knowledge and identification purpose. Structure, use mathematical methods for parameter estimation, and establish the transfer function model of the system.

For complex systems, especially complex electromechanical systems, the difficulty of traditional identification methods lies in: due to the complexity of the system itself and the high requirements for control accuracy, one of the core steps in the identification process is the routine determination of the model structure. The effect of the method is not ideal, and it is difficult to accurately specify the model structure of the system, which affects the subsequent system identification and the work of designing the controller based on the transfer function model.

In the prior art, for some complex pure mechanical structures, in the analysis, the physical object of the system can be disassembled into a plurality of simple structures, and then experiments are designed for each part separately, and after the input/output data is obtained, the system identification is used to establish the transfer function. . However, for some high-precision mechanical structures, it is inconvenient to disassemble during the test. Therefore, even if the system can be decomposed into multiple links from a theoretical point of view, the overall mechanical structure that cannot be disassembled is for the accuracy of the actual data of each link. The measurement created difficulties.

To sum up, how to provide a control method for adjusting the turntable with six degrees of freedom capable of realizing accurate control is an urgent problem to be solved by those skilled in the art.

SUMMARY OF THE INVENTION

In view of this, the purpose of the present invention is to provide a control method for a six-degree-of-freedom adjustment turntable, which can realize precise control of the six-degree-of-freedom adjustment turntable.

In order to achieve the above object, the present invention provides the following technical solutions:

A control method for a six-degree-of-freedom adjustment turntable is applied to a six-degree-of-freedom adjustment turntable, wherein the six-degree-of-freedom adjustment turntable includes a turntable, a voice coil motor and a motor controller, and the control method includes:

dividing the six-DOF adjustment turntable into a mechanical part and an electrical part;

Perform harmonic response analysis on the mechanical part to obtain N groups of frequency response data under different inputs, perform systematic identification on a group of the frequency response data, and establish a first transfer function model of different order-zero number combinations. Set, select the preferred transfer function model from the set of the first transfer function model and use its order as the target order, and the number of zeros as the number of target zeros;

Perform systematic identification on N groups of the frequency response data, establish a set of second transfer function models of the target order and target zero points, and select a preferred transfer function model from the set of second transfer function models as a mechanical transfer function model; the mechanical transfer function model is a transfer function model containing parameters;

Setting the preset order and preset zero points of the electrical part, performing systematic identification on multiple groups of preset signals, and establishing a set of third transfer function models of the preset order and preset zero points, Select a preferred transfer function model from the set of the third transfer function models as an electrical transfer function model; the electrical transfer function model is a transfer function model containing parameters;

Obtaining an overall transfer function model according to the mechanical transfer function model and the electrical transfer function model, obtaining control parameters of the motor controller according to the overall transfer function model, and controlling the motor controller according to the control parameters Control the operation of the turntable.

Preferably, obtaining different inputs in the N groups of frequency response data under different inputs includes: different frequencies or different magnitudes of applied forces.

Preferably, a set of frequency response data is systematically identified, and a set of first transfer function models of different order-zero point combinations is established, including:

selecting a group of the frequency response data from the N groups of the frequency response data;

The selected frequency response data is systematically identified by the auxiliary variable method, and several transfer function models are established. gather.

Preferably, a preferred transfer function model is selected from the set of the first transfer function models and the target order and target zeros are determined, including:

Obtain the amplitude-frequency characteristic curve and the normalized root mean square error of each of the transfer function models in the set of the first transfer function models, and select a preferred transfer function model according to the degree of similarity between the two, wherein the degree of similarity The large transfer function model is the preferred transfer function model;

The order of the preferred transfer function model is obtained as the target order, and the zero point number of the preferred transfer function model is taken as the target zero point number.

Preferably, systematic identification is performed on the N groups of the frequency response data, and a set of second transfer function models of the target order and the target zero points is established, including:

Use the auxiliary variable method to systematically identify each group of the frequency response data;

Establish a set of second transfer function models of the transfer function model with the target order as the order and the target zero points as zero points, wherein the order of each of the transfer function models is The target order and the number of zero points are both the number of target zero points.

Preferably, a preferred transfer function model is selected from the set of the second transfer function models as the mechanical transfer function model, including:

Obtain the amplitude-frequency characteristic curve and the standardized root mean square error of each transfer function model in the set of the second transfer function models, and select the preferred transfer function model according to the degree of similarity between the two, wherein the transfer function model with the largest degree of similarity is selected. The functional model is the mechanical transfer function model.

Preferably, setting the preset order and preset zero points of the electrical part includes:

The transfer function model of the electrical part is determined according to the type of the electrical part, and the order corresponding to the transfer function model of the electrical part is obtained as the preset order, and the corresponding zero point number is used as the preset zero point number.

Preferably, a system identification is performed on a plurality of groups of preset signals, a set of third transfer function models of the preset order and the preset zero points is established, and a preferred set of transfer function models is selected from the set of third transfer function models. Transfer function model, as an electrical transfer function model; includes:

Taking the voltage signal and the output displacement as the input/output quantities of the preset signal respectively, using the preset signal as the input/output data, and using the auxiliary variable method to establish the preset order number and the preset zero point number A collection of third transfer function models of ;

Obtain the amplitude-frequency characteristic curve and the standardized root mean square error of each transfer function model in the set of the third transfer function model, and select the preferred transfer function model according to the degree of similarity between the two, wherein the transfer function model with the largest degree of similarity is the transfer function model. The functional model is the electrical transfer function model.

Controlling to obtain the control parameters of the motor controller according to the overall transfer function model, and controlling the motor controller to control the work of the turntable according to the control parameters, including:

The output current of the motor controller is controlled according to the overall transfer function model, and the motor controller is controlled to output the output current to the voice coil motor, so as to control the operation of the turntable.

The invention reasonably divides a complex mechanical-electrical system into a mechanical part and an electrical part, and establishes a transfer function model by means of frequency response analysis for the mechanical part, which reduces the difficulty of determining the structure of the complex system model in the system identification method; Systems with complex structures and difficult input/output data measurement provide a proven solution.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only It is an embodiment of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to the provided drawings without creative work.

1 is a flowchart of a control method for a six-degree-of-freedom adjustment turntable provided by the present invention;

Fig. 2 is the flow chart of the specific embodiment provided by the present invention;

3 is a schematic diagram of a six-degree-of-freedom adjustment turntable provided by the present invention;

Fig. 4 is the front view of the motor control system of the six-degree-of-freedom turntable;

Fig. 5 is the top view of the motor control system of the six-degree-of-freedom turntable;

FIG. 6 is a left side view of the motor control system of the six-degree-of-freedom turntable.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to 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, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The core of the present invention is to provide a control method for adjusting the turntable with six degrees of freedom, which can realize precise control of the adjusting turntable with six degrees of freedom, and has good control effect.

Please refer to FIG. 1 to FIG. 6. FIG. 1 is a flowchart of a control method for a six-degree-of-freedom adjustment turntable provided by the present invention; FIG. 2 is a flowchart of a specific embodiment provided by the present invention; Figure 4 is a front view of the motor control system of the six degrees of freedom turntable; Figure 5 is a top view of the motor control system of the six degrees of freedom turntable; Figure 6 is the motor control system of the six degrees of freedom turntable. Left view.

A control method for a six-degree-of-freedom adjustment turntable provided by the present application is applied to a six-degree-of-freedom adjustment turntable. The six-degree-of-freedom adjustment turntable includes a turntable, a voice coil motor and a motor controller, and the control method includes the following steps:

Step S1, dividing the six-degree-of-freedom adjustment turntable into a mechanical part and an electrical part;

Step S2, perform harmonic response analysis on the mechanical part to obtain N groups of frequency response data under different inputs, perform systematic identification on a group of frequency response data, and establish a set of first transfer function models with different order-zero number combinations , select the preferred transfer function model from the set of the first transfer function model and use its order as the target order and zeros as the target zeros;

Step S3, perform systematic identification on N groups of frequency response data, establish a set of second transfer function models of target order and target zero points, and select a preferred transfer function model from the set of second transfer function models as the mechanical transfer function model. ;

Step S4, setting the preset order and preset zero points of the electrical part, performing system identification on multiple groups of preset signals, and establishing a set of third transfer function models of preset order and preset zero points, from the third Select the preferred transfer function model from the set of transfer function models as the electrical transfer function model;

Step S5, obtain an overall transfer function model according to the mechanical transfer function model and the electrical transfer function model, control the control parameters of the motor controller according to the overall transfer function model, and control the motor controller to control the work of the turntable according to the control parameters.

For the schematic diagrams of the six-degree-of-freedom adjustment turntable, please refer to FIGS. 4 to 6 , wherein, the lower part of the turntable 1 is provided with support and adjustment legs, which form six directions of support and adjustment for the turntable 1. The support forces are F ₁ , F ₂ , F ₃ , F ₄ , F ₅ and F ₆ .

Several support and adjustment legs can be adjusted respectively to change the space state of the turntable. The above-mentioned support and adjustment legs are respectively connected to the voice coil motor. The above-mentioned connection structures such as the turntable are the mechanical parts of the six-degree-of-freedom adjustment turntable. Degree of freedom adjusts the electrical part of the turntable.

Dividing the whole into a mechanical part and an electrical part in step S1 does not mean dividing the entity, but means analyzing and investigating the two respectively.

In step S2, the mechanical part can be modeled to obtain a mechanical model, and the mechanical model refers to the three-dimensional structural model of the mechanical part, which can be modeled and analyzed by software. Harmonic response analysis and simulation can be performed for the modeled mechanical model. Harmonic response analysis and simulation is used to determine the steady-state response of a linear structure when it is subjected to a load that changes according to a sinusoidal law with time. The purpose is to calculate the structure under several frequencies. The response value versus frequency curve, the data obtained and used in this application is a Bode plot, that is, a logarithmic frequency characteristic curve, including an amplitude plot and a phase angle plot. The harmonic response analysis simulation is applicable to the analytical form of the turntable in this application.

Among them, the harmonic response analysis process can input different types or values of input values to obtain N groups of frequency response data, and only perform system identification for one group to obtain the target number of first transfer function models and form the first transfer function. Collection of models.

The above input values of different types or values include different frequencies, etc., so as to obtain frequency response data sets established by N sets of different input values.

This application provides a solution for performing harmonic response analysis based on ANSYS modeling analysis. It should be noted that the harmonic response analysis simulation includes: the material, density and frequency range of the input harmonic response analysis simulation object.

Optionally, in this application, the frequency setting may be 1-1000 Hz, so as to obtain N groups of frequency response data.

In the process of the above-mentioned system identification, it is necessary to establish transfer function models of different order-zero point combinations to form several selectable transfer function models, wherein the transfer function model may include coefficients, or it may be a transfer function that does not include coefficients. The model structure thus and forms a set of transfer function models, called the set of first transfer function models. In this process, the system identification by the auxiliary variable method in the prior art may be referred to. Since the difference between the set of transfer function models and the set of transfer function model structures is only whether they have coefficients, and the coefficients are not required in the subsequent steps, therefore, it is expressed here as a set of transfer function models and a set of transfer function model structures. are also included in this scope.

Then, through optimization selection, a set of preferred transfer function models is obtained, so as to determine the target order and target zeros.

In step S3, the N groups of frequency response data obtained in step 2 and the N groups of frequency response data are systematically identified to establish a transfer function model with the above target order as the order and the target zero points as zero points, and form After the collection, the optimization selection is carried out, and the mechanical transfer function model is finally determined. The transfer function model obtained in step S3 needs to contain parameters, and is not a transfer function model structure.

In step S4, the preset order number and the preset zero point number of the electrical part are set, and the electrical part model corresponding to the type of the electrical part can be determined according to the prior knowledge and theoretical analysis. Optionally, it is the electrical part mentioned later. Part of the transfer function model, because the mechanical part will also take the transfer function model as the final result, and the final overall transfer function model can be obtained by operating the two transfer functions.

Perform system identification on multiple groups of preset signals, the preset signals may include voltage signals, etc., establish a set of third transfer function models based on the above preset order and preset zero points, from the set of third transfer function models The preferred transfer function model is selected as the electrical transfer function model, and the electrical transfer function model is a transfer function model with parameters; this process is similar to the above-mentioned process, and will not be repeated here.

The principle of optimal selection can be based on preset criteria, for example, in terms of the characteristics of the amplitude-frequency characteristic curve corresponding to the transfer function model, and it is preferable to specify that the characteristic selection value is within the preset interval. It can also be selected according to the numerical value of the normalized root mean square error of the transfer function model, and the numerical value within the preset range or the closest preset value is preferred. Of course, it can also be selected according to the similarity between the normalized root mean square error of the transfer function model and the amplitude-frequency characteristic curve, and the one with the largest similarity in the set is preferred. In a preferred embodiment, the selection of the above optimization can be obtained according to the amplitude of the Bode plot of the transfer function model. Specifically, the harmonic response analysis and simulation of the mechanical model is realized by ANSYS simulation, and the amplitude plot obtained by the simulation analysis is the same as The magnitude diagram of the Bode plot of the established transfer function model, the intuitive closeness of the two can be used to obtain the intuitive closeness; another way is to pass the magnitude of the Bode plot of the transfer function model and the NRMSE of the transfer function model. The similarity of the calculated values is determined.

The method provided by this application is not limited to the above-mentioned optimization methods, and the key point is to screen out several preferred models from the actual models obtained by modeling, and obtain the preferred models related to the actual models, not the theoretical optimal models obtained by using prior knowledge. optimal solution.

In this application, since the mechanical part in the overall model is obtained according to the analysis of the actual model, the obtained control parameters can be used to control the operation of the motor controller according to the actual structure of the turntable system, and the control of the turntable by the voice coil motor can be realized. It is more in line with the actual characteristics of the turntable.

The present invention reasonably divides a complex mechanical-electrical system into a mechanical part and an electrical part. For the mechanical part that is inconvenient for further disassembly, the frequency response analysis is used to establish a transfer function model, which reduces the complexity of determining the system identification method. The difficulty of the system model structure provides an effective solution for analyzing the system with complex structure and difficult input/output data measurement.

In step S2, different inputs in the N groups of frequency response data under different inputs are obtained, including different frequencies or different magnitudes of applied forces.

In step S2, a method for systematically identifying a set of frequency response data and establishing a set of first transfer function models of different order-zero point combinations specifically includes the following steps:

Step S21, selecting a group of frequency response data from the N groups of frequency response data;

Step S22 , use the auxiliary variable method to systematically identify the selected frequency response data, and establish several transfer function models. The order of the transfer function models and the combinations of zeros are different to form a set of first transfer function models.

Specifically, using a certain group of frequency response data as input/output data, the auxiliary variable method (IV) is used to systematically identify the mechanical part of the system, and a set G of transfer function models with different orders and zeros is established.

G={G _1,0 (s),G _2,0 (s),G _2,1 (s)...G _np,nz-1 (s),G _np,nz (s)}

Among them, np represents the order, or the number of poles, nz represents the number of zeros, and nz<np, and the specific upper limit can be adjusted within a reasonable range. It should be noted that the values of the above order and zero points may be: 1≤np≤20, np∈Z, 0≤nz≤19, nz∈Z, and Z is an integer.

Among them, the upper limit of np is 20, and the upper limit of nz is 19, because in common application situations, the selection of this order value and zero point value can already meet the analysis needs. Of course, the above values can also be adjusted according to the actual situation.

In this embodiment, the auxiliary variable method is used for system identification, and the input/output data can be set as the above single set of frequency response data to obtain the input/output transfer function model, and the transfer function model is specifically G(s).

At the same time, due to different orders and zero points, different transfer function models G(s) can be obtained, which are divided by the above orders and zero points, so as to obtain the set of the above transfer function models G(s):

G={G _1,0 (s),G _2,0 (s),G _2,1 (s)...G _np,nz-1 (s),G _np,nz (s)}

Specifically, performing harmonic response analysis on the mechanical part above to obtain N groups of frequency response data under different inputs, including: performing harmonic response analysis and simulation on the mechanical part model established in ANSYS finite element analysis software, setting the frequency range, analyzing And obtain the frequency response data under N groups of different inputs.

The above frequency range may specifically be 1-1000 Hz.

In step S2, the method for selecting a preferred transfer function model from the set of first transfer function models and determining the target order and target zero points specifically includes the following steps:

Step S23: Acquire the amplitude-frequency characteristic curve and the normalized root mean square error of each transfer function model in the set of first transfer function models, and select the preferred transfer function model according to the degree of similarity between the two, wherein the transfer function model with the greatest degree of similarity is selected. The function model is the preferred transfer function model;

Step S24 , obtaining the order of the preferred transfer function model as the target order, and taking the zero point number of the preferred transfer function model as the target zero point number.

The obtained transfer function models G(s) can be used to obtain the corresponding amplitude-frequency characteristic curve, standardized root mean square error, etc., and the calculated value of the standardized root mean square error and the image of the amplitude-frequency characteristic curve can be used to obtain similarity or approximation. Each transfer function model G(s) has a corresponding similarity, and all the similarities can be compared. The similarity is close to 100%, indicating that the model features of the transfer function model G(s) are more optimized. Therefore, When selecting the optimized transfer function model G(s), the optimal solution can be obtained according to the above similarity. Since the total number of transfer function models G(s) is limited, the optimal solution of similarity can be selected from the set of transfer function models formed by different orders and zero points.

Specifically, obtaining the standardized root mean square error of each transfer function model includes obtaining two given matrices x[m,n] and y[m,n] to obtain the standardized root mean square error NRMSE.

Specifically, the unified form of each transfer function model is obtained, as follows:

Select the determination of the preferred transfer function model, wherein a ₁ , a ₂ , ..., an _npm , b ₀ , b ₁ , b ₂ , ..., b _nzm in the general formula are all coefficients, npm is the order, and nzm is The number of zero points, here G _npm,nzm (s) means that the obtained transfer function model and its optimal solution are in the form of the above formula, and the value of each coefficient is determined according to the actual situation of each transfer function model.

The order and zero points of the obtained transfer function model selected for optimization are extracted and used as the target order and target zero points respectively.

In step S3, the steps of systematically identifying the N groups of frequency response data, and establishing a set of second transfer function models of target order and target zero points, specifically include the following steps:

Step S31, using the auxiliary variable method to systematically identify each group of frequency response data;

Step S32, establishing a set of second transfer function models with the target order as the order and the transfer function model with the target zero points as zero points, wherein the order of each transfer function model is the target order, zero. Points are all target zero points.

It should be noted that the second system identification is performed in step S3, and the system identification of each group of frequency response data is performed again by the auxiliary variable method, and the selection of the order and the number of zero points for the system identification this time is not based on the above. For the selection of the permutation and combination formula in a given range in the embodiment, the above-mentioned target order and target zero points are used as the establishment of the transfer function model, so it is necessary to obtain the above-mentioned target order and target zero points.

The preferred target order and target zeros obtained through the above optimization are the preferred order and zeros, and the above step S3 is the transfer function of the determined order and zeros obtained by systematically identifying all the frequency response data through the two Model.

Optionally, in step S3, a preferred transfer function model is selected from the set of second transfer function models as the mechanical transfer function model, including:

Step S33, acquiring the amplitude-frequency characteristic curve and the normalized root mean square error of each transfer function model in the set of second transfer function models, and selecting the preferred transfer function model according to the degree of similarity between the two, wherein the transfer function with the greatest degree of similarity is the transfer function model. The model is the mechanical transfer function model G _m (s).

The method for selecting the preferred transfer function model is the same as the above-mentioned optimization method for the set of the first transfer function model, which is not repeated here.

Optionally, in step S4, the preset order number and the preset zero point number of the electrical part are set, including:

Step S41 , determining the transfer function model of the electrical part according to the type of the electrical part, and obtaining the order corresponding to the transfer function model of the electrical part as the preset order, and the corresponding zero point number as the preset zero point number.

Determine the model structure of the electrical part, which is a transfer function model. Specifically, the model structure of the electrical part is determined by combining the prior knowledge and the analysis of the electrical link of the voice coil motor.

The order and the number of zero points are obtained through the transfer function model of the above electrical part, which are respectively used as the preset order number and the preset number of zero points.

Optionally, in step S4, system identification is performed on multiple groups of preset signals, and a set of third transfer function models of the preset order and the preset zero points is established, and the third transfer function model is obtained from the third transfer function model. Select the preferred transfer function model from the collection as the electrical transfer function model; including:

Step S42, using the voltage signal and the output displacement as the input/output amount of the preset signal respectively, using the preset signal as the input/output data, and using the auxiliary variable method to establish the preset order, the preset order Set the set of third transfer function models with zero points;

Step S43, acquiring the amplitude-frequency characteristic curve and the normalized root mean square error of each transfer function model in the third set of transfer function models, and selecting a preferred transfer function model according to the degree of similarity between the two, wherein the degree of similarity The large transfer function model is the electrical transfer function model.

Specifically, the third transfer function model is determined in the same manner as above, using multiple sets of input values as preset signals, wherein the voltage signal may be a sinusoidal signal, a random Gaussian white noise signal, or the like.

Optionally, in step S5, the overall transfer function model is obtained according to the mechanical transfer function model and the electrical transfer function model, including:

Step S51 , obtaining a mechanical transfer function model and an electrical transfer function model, and using this to obtain an overall transfer function model of the six-degree-of-freedom adjustment turntable.

The method of obtaining the overall model by exporting the model and the electrical part model, specifically includes the following steps:

Obtain the preferred transfer function model G _m (s), and obtain the electrical part model _Ge (s);

Get the overall model G(s); where:

G(s)=G _m (s)·G _e (s)

G _m (s) is the preferred transfer function model, and _Ge (s) is the electrical part model.

Optionally, in step S5, control parameters of the motor controller are obtained according to the overall transfer function model control, and the motor controller is controlled to control the work of the turntable according to the control parameters, including:

Step S53: Control the output current of the motor controller according to the overall transfer function model, and control the motor controller to output the above-mentioned output current to the voice coil motor to control the operation of the turntable.

It should be noted that, after the overall model structure is determined, the motor controller of the voice coil motor can be controlled to work according to the transfer function of the structure, so that the voice coil motor can be controlled according to the motor controller.

Specifically, the transfer function model of the above-mentioned overall structure can be analyzed to obtain the characteristics of the transfer function, and the motor controller can be controlled with this characteristic. The motor controller can be a PID controller with feedback control. Degrees of freedom adjust the control of the work of the turntable.

The setting of the motor controller in the prior art is usually based on a priori data, or a general analysis is performed. Considering the characteristics in the transfer function model, the obtained motor controller has the characteristics of adjusting the turntable with six degrees of freedom. Therefore, the parameter setting can achieve the purpose of accurately controlling the voice coil motor. For the motor controller with feedback control, The improvement of the accuracy of the feedback control parameters can better improve the control accuracy of the motor controller.

Optionally, the above-mentioned adjustment of the motor controller mainly changes the current output by the voice coil motor of the motor controller, that is to say, the current delivered by the motor controller to the voice coil motor can be changed, so as to realize the adjustment of the voice coil motor. to make it more in line with the characteristics and actual state of the current six-degree-of-freedom adjustment turntable.

In the above method, the motor control with feedback control is mainly used for description. Of course, other types of motor controllers or control forms for voice coil motors are also possible.

The invention divides the complex electromechanical system into mechanical parts and electrical parts, and uses ANSYS finite element analysis software to model the complex mechanical parts in the system, and carries out harmonic response analysis, based on the acquired frequency response data, with the help of auxiliary variable method ( IV), establish the system transfer function model of the mechanical part. For the simple electrical part of the system, the system model structure is determined based on prior knowledge, and the transfer function model of the electrical part is established directly based on the experimental data using the auxiliary variable method (IV). Finally, according to the transfer function model of the mechanical part and the electrical part of the system, the overall transfer function model of the system is calculated.

The application establishes a transfer function model by means of finite element analysis, which reduces the difficulty of determining the model structure of a complex system in the system identification method, and provides an effective solution for analyzing systems with complex structures and difficult input/output data measurement.

In addition to the main steps and internal relationships of the control method for the six-degree-of-freedom adjustment turntable provided in the above-mentioned various embodiments, the calculation and synthesis method of the transfer function model included therein, and the contents of other parts, please refer to the prior art, this paper does not Repeat.

The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the points that are different from other embodiments, and the same and similar parts between the various embodiments can be referred to each other.

The control method for the six-degree-of-freedom adjustment turntable provided by the present invention has been described in detail above. The principles and implementations of the present invention are described herein by using specific examples, and the descriptions of the above embodiments are only used to help understand the method and the core idea of the present invention. It should be pointed out that for those skilled in the art, without departing from the principle of the present invention, several improvements and modifications can also be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

A control method for a six-degree-of-freedom adjustment turntable, which is applied to a six-degree-of-freedom adjustment turntable, wherein the six-degree-of-freedom adjustment turntable includes a turntable, a voice coil motor and a motor controller, wherein the control method includes:

dividing the six-DOF adjustment turntable into a mechanical part and an electrical part;

Perform harmonic response analysis on the mechanical part to obtain N groups of frequency response data under different inputs, perform systematic identification on a group of the frequency response data, and establish a first transfer function model of different order-zero number combinations. Set, select the preferred transfer function model from the set of the first transfer function model and use its order as the target order, and the number of zeros as the number of target zeros;

Perform systematic identification on N groups of the frequency response data, establish a set of second transfer function models of the target order and target zero points, and select a preferred transfer function model from the set of second transfer function models as a mechanical transfer function model; the mechanical transfer function model is a transfer function model containing parameters;

Setting the preset order and preset zero points of the electrical part, performing systematic identification on multiple groups of preset signals, and establishing a set of third transfer function models of the preset order and preset zero points, Select a preferred transfer function model from the set of the third transfer function models as an electrical transfer function model; the electrical transfer function model is a transfer function model containing parameters;

Obtaining an overall transfer function model according to the mechanical transfer function model and the electrical transfer function model, obtaining control parameters of the motor controller according to the overall transfer function model, and controlling the motor controller according to the control parameters Control the operation of the turntable.
The control method for adjusting a turntable with six degrees of freedom according to claim 1, wherein obtaining different inputs in the N groups of frequency response data under different inputs comprises: different frequencies or different magnitudes of applied forces.
The control method for adjusting a turntable with six degrees of freedom according to claim 2, wherein a set of frequency response data is systematically identified, and a set of first transfer function models of different order-zero point combinations is established, include:

selecting a group of the frequency response data from the N groups of the frequency response data;

The selected frequency response data is systematically identified by the auxiliary variable method, and several transfer function models are established. gather.
The control method for adjusting a turntable with six degrees of freedom according to claim 3, wherein selecting a preferred transfer function model from the set of the first transfer function models and determining the target order and target zeros, comprising:

Obtain the amplitude-frequency characteristic curve and the normalized root mean square error of each of the transfer function models in the set of the first transfer function models, and select a preferred transfer function model according to the degree of similarity between the two, wherein the degree of similarity The large transfer function model is the preferred transfer function model;

The order of the preferred transfer function model is obtained as the target order, and the zero point number of the preferred transfer function model is taken as the target zero point number.
The control method for adjusting a turntable with six degrees of freedom according to claim 4, wherein the N groups of the frequency response data are systematically identified, and a second transfer function model of the target order and the target zero points is established. collection, including:

Use the auxiliary variable method to systematically identify each group of the frequency response data;

Establish a set of second transfer function models of the transfer function model with the target order as the order and the target zero points as zero points, wherein the order of each of the transfer function models is The target order and the number of zero points are both the number of target zero points.
The control method for adjusting a turntable with six degrees of freedom according to claim 1, wherein, selecting a preferred transfer function model from the set of the second transfer function models as the mechanical transfer function model, comprising:

Obtain the amplitude-frequency characteristic curve and the standardized root mean square error of each transfer function model in the set of the second transfer function models, and select the preferred transfer function model according to the degree of similarity between the two, wherein the transfer function model with the largest degree of similarity is selected. The functional model is the mechanical transfer function model.
The control method for adjusting a turntable with six degrees of freedom according to any one of claims 1 to 6, wherein setting the preset order and preset zero points of the electrical part includes:

The transfer function model of the electrical part is determined according to the type of the electrical part, and the order corresponding to the transfer function model of the electrical part is obtained as the preset order, and the corresponding zero point number is used as the preset zero point number.
The control method for adjusting a turntable with six degrees of freedom according to claim 7, wherein a system identification is performed on a plurality of sets of preset signals, and a third transfer function model of the preset order and the preset zero points is established , select the preferred transfer function model from the set of the third transfer function model, as the electrical transfer function model; including:

Taking the voltage signal and the output displacement as the input/output quantities of the preset signal respectively, using the preset signal as the input/output data, and using the auxiliary variable method to establish the preset order number and the preset zero point number A collection of third transfer function models of ;

Obtain the amplitude-frequency characteristic curve and the standardized root mean square error of each transfer function model in the set of the third transfer function model, and select the preferred transfer function model according to the degree of similarity between the two, wherein the transfer function model with the largest degree of similarity is the transfer function model. The functional model is the electrical transfer function model.
The control method for adjusting a turntable with six degrees of freedom according to claim 8, wherein the control parameters of the motor controller are obtained according to the overall transfer function model control, and the motor controller is controlled according to the control parameters Control the operation of the turntable, including:

The output current of the motor controller is controlled according to the overall transfer function model, and the motor controller is controlled to output the output current to the voice coil motor, so as to control the operation of the turntable.