阅读说明：本技术 一种基于名义模型的冷原子重力仪主动隔振控制方法 (Cold atom gravimeter active vibration isolation control method based on nominal model ) 是由 罗东云 邓长寿 曾伟 樊莉丽 刘清平 于 2021-08-23 设计创作，主要内容包括：本发明提供了一种基于名义模型的冷原子重力仪主动隔振控制方法,包括以下步骤：建立冷原子重力仪主动隔振模型；建立真实对象的名义模型；设计所述名义模型的控制律；设计冷原子重力仪主动隔振系统的控制律,解决了目前控制方法没有考虑地面振动等外界扰动随机性和模型不确定性的问题,通过建立名义模型,使得冷原子重力仪主动隔振系统的振动速度和振动位移迅速收敛,进而提高冷原子重力仪主动隔振系统的控制精度。(The invention provides a cold atom gravimeter active vibration isolation control method based on a nominal model, which comprises the following steps: establishing an active vibration isolation model of a cold atom gravimeter; establishing a nominal model of the real object; designing a control law of the nominal model; the control law of the active vibration isolation system of the cold atom gravimeter is designed, the problems that the randomness of external disturbance such as ground vibration and the like and model uncertainty are not considered in the existing control method are solved, the vibration speed and the vibration displacement of the active vibration isolation system of the cold atom gravimeter are rapidly converged by establishing a nominal model, and the control precision of the active vibration isolation system of the cold atom gravimeter is further improved.)

1. A cold atom gravimeter active vibration isolation control method based on a nominal model is characterized by comprising the following steps:

establishing an active vibration isolation model of a cold atom gravimeter;

establishing a nominal model of the real object;

designing a control law of the nominal model;

and designing a control law of the active vibration isolation system of the cold atom gravimeter.

2. The cold atom gravimeter active vibration isolation control method based on the nominal model according to claim 1, wherein the step of establishing the cold atom gravimeter active vibration isolation model includes:

wherein ξ₀Is the damping coefficient of the system, omega₀Is the system natural vibration frequency, F is the force generated by the voice coil motor, x is the vibration displacement of the Raman reflector,is a Raman reflectorThe speed of vibration of the vibration means (c),is the vibration acceleration of the Raman reflector, y is the ground vibration displacement,the ground vibration speed is adopted, and m is the mass of the Raman reflector;

let F be expressed as:

F＝K_VCY_VCu (2)

where u is the controller input, K_VCIs the current gain coefficient of the voice coil motor, Y_VCIs a voltage to current gain factor;

bringing F into the formula (1) to obtain

(3) Formula both sides remove K_VCY_VCIs/m to obtain

Definition ofJ＝2ξ₀ω₀m/K_VCY_VC，B＝ω₀ ²m/K_VCY_VCAnd the formula (4) is substituted, and the obtained cold atom gravimeter active vibration isolation model is as follows:

。

3. the cold atom gravimeter active vibration isolation control based on nominal model as set forth in claim 2

A method, characterized in that the step of establishing a nominal model of the real object comprises:

wherein x is_nFor the vibrational displacement of the nominal model raman mirror,the vibration velocity of the nominal model raman mirror,vibration acceleration of Raman mirror of nominal model, μ is controller input of nominal model, J_n，B_nRespectively are the nominal values of J and B;

defining the expected value of the vibration displacement as x_d，For vibration displacement desired value x_dThe first derivative of (a) is,for vibration displacement desired value x_dThe second derivative of (a);

defining a nominal model with a tracking error of e ═ x_n-x_dIts first derivative isSecond derivative ofAnd substituting it into equation (6):

definition of m/K_VCY_VCAnd (7) substituting the formula to obtain a nominal model of the real object:

。

4. the active vibration isolation control method for the cold atom gravimeter based on the nominal model as claimed in claim 3, wherein the step of designing the control law of the nominal model comprises:

substituting equation (8) into equation (9):

wherein h is₁,h₂Is a positive coefficient and satisfies sigma²+(J_n/C+h₂)σ+B_n/C+h₁Hurwitz, sigma is Laplace operator;

take (sigma + k)²0, k > 0, gives J_n/C+h₂＝2k，B_n/C+h₁＝k²H is obtained by the value of k₁,h₂。

5. The cold atom gravimeter active vibration isolation control method based on the nominal model according to claim 4, wherein the step of establishing a control law of the cold atom gravimeter active vibration isolation system includes:

defining:

J_m≤J≤J_M,B_m≤B≤B_M,|d|≤d_M (11)

wherein, J_m,J_MIs a normal number, respectively lower and upper bound of J, B_m,B_MIs aConstants, lower and upper bounds of B, d_MAn upper bound of d;

defining: e.g. of the type_n＝x-x_n；

Defining the slip form surface as:

wherein λ > 0, and λ ═ B_n/J_n；

Defining:

J_a＝1/2(J_m+J_M) (13)

B_a＝1/2(B_m+B_M) (14)

obtaining a control law of the active vibration isolation system of the cold atom gravimeter:

wherein K and h are positive coefficients.

Technical Field

The invention relates to the technical field of cold atom gravimeter active vibration isolation, in particular to a cold atom gravimeter active vibration isolation control method based on a nominal model.

Background

The cold atom gravimeter is a novel quantum sensor which is rapidly developed in the last two decades, and the cold atom gravimeter has the function of realizing high-precision and high-sensitivity gravity acceleration measurement by utilizing technologies such as laser cooling, atom interference and the like. At present, the measurement precision of the cold atom gravimeter reaches micro gamma, and the cold atom gravimeter can be used in the precision engineering measurement fields of mineral resource exploration, geological structure research, oil and gas general survey, spectral identification determination in the scientific field, gravity between substances and the like.

In actual measurement, the accuracy of atomic gravity measurement is affected by ground vibration noise, raman optical phase noise, detection noise and the like, wherein the vibration noise is the most important factor affecting the atomic gravimeter. The minimum natural vibration frequency of the conventional commercial passive vibration isolation platform can be adjusted to 0.5Hz, and the passive vibration isolation platform can be used for isolating the influence of ground vibration above 10Hz on the atomic gravimeter, but the atomic gravimeter is more sensitive to vibration of 0.1-10Hz, so that the single passive vibration isolation platform cannot meet the vibration isolation requirement of the atomic gravimeter. Although the natural vibration frequency of the whole passive vibration isolation platform can be adjusted, the natural vibration frequency is adjusted too low, the whole system can present a nonlinear effect, the ground vibration near the passive vibration isolation self-frequency is not inhibited, but becomes larger on the basis of the original vibration, so that an active vibration isolation system needs to be introduced to inhibit the vibration of the frequency band, but the active vibration isolation system is influenced by a large number of uncertain factors, and the randomness of external disturbance such as the ground vibration and the uncertainty of a model are not considered in the current control method.

Disclosure of Invention

The invention discloses a cold atom gravimeter active vibration isolation control method based on a nominal model, which solves the problems that the randomness of external disturbance such as ground vibration and the like and model uncertainty are not considered in the conventional control method, and enables the vibration speed and the vibration displacement of a cold atom gravimeter active vibration isolation system to be rapidly converged by establishing the nominal model, thereby improving the control precision of the cold atom gravimeter active vibration isolation system.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

the invention discloses a cold atom gravimeter active vibration isolation control method based on a nominal model, which comprises the following steps of:

establishing an active vibration isolation model of a cold atom gravimeter;

establishing a nominal model of the real object;

designing a control law of the nominal model;

and designing a control law of the active vibration isolation system of the cold atom gravimeter.

Further, the step of establishing the active vibration isolation model of the cold atom gravimeter comprises the following steps:

wherein ξ₀Is the damping coefficient of the system, omega₀Is the system natural vibration frequency, F is the force generated by the voice coil motor, x is the vibration displacement of the Raman reflector,is the vibration speed of the raman mirror,is the vibration acceleration of the Raman reflector, y is the ground vibration displacement,the ground vibration speed is adopted, and m is the mass of the Raman reflector;

let F be expressed as:

F＝K_VCY_VCu (2)

where u is the controller input, K_VCIs the current gain coefficient of the voice coil motor, Y_VCIs a voltage to current gain factor;

bringing F into the formula (1) to obtain

(3) Formula both sides remove K_VCY_VCIs/m to obtain

Definition ofJ＝2ξ₀ω₀m/K_VCY_VC，B＝ω₀ ²m/K_VCY_VCAnd the formula (4) is substituted, and the obtained cold atom gravimeter active vibration isolation model is as follows:

further, the step of establishing a nominal model of the real object comprises:

wherein x is_nFor the vibrational displacement of the nominal model raman mirror,the vibration velocity of the nominal model raman mirror,vibration acceleration of Raman mirror of nominal model, μ is controller input of nominal model, J_n，B_nRespectively are the nominal values of J and B;

defining the expected value of the vibration displacement as x_d，For vibration displacement desired value x_dThe first derivative of (a) is,for vibration displacement desired value x_dThe second derivative of (a);

defining a nominal model with a tracking error of e ═ x_n-x_dIts first derivative isSecond derivative ofAnd substituting it into equation (6):

definition of m/K_VCY_VCAnd (7) substituting the formula to obtain a nominal model of the real object:

further, the step of designing a control law of the nominal model comprises:

substituting equation (8) into equation (9):

wherein h is₁,h₂Is a positive coefficient and satisfies sigma²+(J_n/C+h₂)σ+B_n/C+h₁Hurwitz, sigma is Laplace operator;

take (sigma + k)²0, k > 0, gives J_n/C+h₂＝2k，B_n/C+h₁＝k²H is obtained by the value of k₁,h₂。

Further, the step of establishing a control law of the active vibration isolation system of the cold atom gravimeter comprises the following steps:

defining:

J_m≤J≤J_M,B_m≤B≤B_M,|d|≤d_M (11)

wherein, J_m,J_MIs a normal number, respectively lower and upper bound of J, B_m,B_MIs a normal number, is the lower and upper bounds of B, d_MAn upper bound of d;

defining: e.g. of the type_n＝x-x_n；

Defining the slip form surface as:

wherein λ > 0, and λ ═ B_n/J_n；

Defining:

J_a＝1/2(J_m+J_M) (13)

B_a＝1/2(B_m+B_M) (14)

obtaining a control law of the active vibration isolation system of the cold atom gravimeter:

wherein K and h are positive coefficients.

The beneficial technical effects are as follows:

the invention discloses a cold atom gravimeter active vibration isolation control method based on a nominal model, which comprises the following steps of: establishing an active vibration isolation model of a cold atom gravimeter; establishing a nominal model of the real object; designing a control law of the nominal model; the control law of the active vibration isolation system of the cold atom gravimeter is designed, the problems that the randomness of external disturbance such as ground vibration and the like and model uncertainty are not considered in the existing control method are solved, the vibration speed and the vibration displacement of the active vibration isolation system of the cold atom gravimeter are rapidly converged by establishing a nominal model, and the control precision of the active vibration isolation system of the cold atom gravimeter is further improved.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings used in the description of the embodiments will be briefly described below.

FIG. 1 is a flow chart illustrating steps of a cold atom gravimeter active vibration isolation control method based on a nominal model according to the present invention;

FIG. 2 is a diagram illustrating a structure of a control system in the active vibration isolation control method for a cold atom gravimeter based on a nominal model according to the present invention;

FIG. 3 is a diagram showing the comparison of vibration displacement after the cold atom gravimeter active vibration isolation control method based on a nominal model is controlled and the PID control method is controlled according to the invention;

FIG. 4 is a diagram comparing the vibration speed of a cold atom gravimeter according to the present invention after being controlled by a nominal model based active vibration isolation control method and a PID control method;

fig. 5 is a graph comparing the influence of the vibration on the gravity measurement phase angle of the cold atomic gravimeter after being controlled by the cold atomic gravimeter active vibration isolation control method based on the nominal model and the PID control method according to the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

The invention discloses a cold atom gravimeter active vibration isolation control method based on a nominal model, which specifically comprises the following steps of:

s1: establishing an active vibration isolation model of a cold atom gravimeter;

specifically, the step of establishing the active vibration isolation model of the cold atom gravimeter comprises the following steps:

wherein ξ₀Is the damping coefficient of the system, omega₀Is the system natural vibration frequency, F is the force generated by the voice coil motor, x is the vibration displacement of the Raman reflector,is the vibration speed of the raman mirror,is the vibration acceleration of the Raman reflector, y is the ground vibration displacement,the ground vibration speed is adopted, and m is the mass of the Raman reflector;

let F be expressed as:

F＝K_VCY_VCu (2)

where u is the controller input, K_VCIs the current gain coefficient of the voice coil motor, Y_VCIs a voltage to current gain factor;

bringing F into the formula (1) to obtain

(3) Formula both sides remove K_VCY_VCIs/m to obtain

Definition ofJ＝2ξ₀ω₀m/K_VCY_VC，B＝ω₀ ²m/K_VCY_VCAnd the formula (4) is substituted, and the obtained cold atom gravimeter active vibration isolation model is as follows:

s2: establishing a nominal model of the real object;

specifically, the step of establishing a nominal model of the real object comprises:

wherein x is_nFor the vibrational displacement of the nominal model raman mirror,the vibration velocity of the nominal model raman mirror,vibration acceleration of Raman mirror of nominal model, μ is controller input of nominal model, J_n，B_nRespectively are the nominal values of J and B;

defining the expected value of the vibration displacement as x_d，For vibration displacement desired value x_dThe first derivative of (a) is,for vibration displacement desired value x_dThe second derivative of (a);

defining a nominal model with a tracking error of e ═ x_n-x_dIts first derivative isSecond derivative ofAnd substituting it into equation (6):

definition of m/K_VCY_VCAnd (7) substituting the formula to obtain a nominal model of the real object:

s3: designing a control law of a nominal model;

specifically, the step of designing the control law of the nominal model comprises the following steps:

substituting equation (8) into equation (9):

wherein h is₁,h₂Is a positive coefficient and satisfies sigma²+(J_n/C+h₂)σ+B_n/C+h₁Hurwitz, sigma is Laplace operator;

take (sigma + k)²0, k > 0, gives J_n/C+h₂＝2k，B_n/C+h₁＝k²H is obtained by the value of k₁,h₂。

S4: and designing a control law of the active vibration isolation system of the cold atom gravimeter.

Specifically, the step of establishing the control law of the active vibration isolation system of the cold atom gravimeter comprises the following steps:

defining:

J_m≤J≤J_M,B_m≤B≤B_M,|d|≤d_M (11)

wherein, J_m,J_MIs a normal number, respectively lower and upper bound of J, B_m,B_MIs a normal number, is the lower and upper bounds of B, d_MAn upper bound of d;

defining: e.g. of the type_n＝x-x_n；

Defining the slip form surface as:

wherein λ > 0, and λ ═ B_n/J_n；

Defining:

J_a＝1/2(J_m+J_M) (13)

B_a＝1/2(B_m+B_M) (14)

obtaining a control law of the active vibration isolation system of the cold atom gravimeter:

wherein K and h are positive coefficients.

The invention discloses a structure of an active vibration isolation control system based on a nominal model cold atom gravimeter, which is shown in figure 2, wherein the control system comprises two controllers, one of the controllers is a controller for an actual system and is used for realizing x → x_nAndand the other controller is a controller for a nominal model to implement x_n→x_dAndthus the entire control system implements x → x_dAnd

as an embodiment of the present invention, the experimental simulation parameters of the cold atom gravimeter active vibration isolation control method based on the nominal model disclosed in the present invention are set as follows:

damping system of setting systemXi number₀＝0.1N·s·m^-1Frequency of natural vibration of system omega₀4.396rad, current gain coefficient K of voice coil motor_VC＝0.1V·A^-1Voltage to current gain coefficient Y_VC＝7.6N·A^-1Mass m of the Raman reflector is 10 kg; gain parameter k is 100, coefficient h₁10000, factor h₂200, nominal value J_n11.6 nominal value B_n254: gain parameter K is 200, h is 0.00005, λ is 30; coefficient h is 0.00005, coefficient λ is 30, and lower bound value J of J_mUpper bound of J11.1_M12.1, lower bound of B_m253.9, upper bound value of B_M＝254.1。

Compared with the traditional PID control method, the PID control law parameters of the cold atom gravimeter active vibration isolation system are as follows: proportional coefficient P10, integral time T_i20 and a differential time T_d＝20。

The invention discloses a cold atom gravimeter active vibration isolation control method based on a nominal model, which enables the vibration speed and the vibration displacement of a cold atom gravimeter active vibration isolation system to be rapidly converged and greatly improves the control precision of the cold atom gravimeter active vibration isolation system, and figures 3-5 show the comparison result of the cold atom gravimeter active vibration isolation control method based on the nominal model disclosed by the embodiment of the invention and a PID control method, and the vibration displacement after being controlled by the control method based on the nominal model is far smaller than the vibration displacement after being controlled by the PID control method; the vibration speed controlled by the control method based on the nominal model is far less than that controlled by the PID control method; the influence of the vibration based on the nominal model control method on the gravity measurement phase angle of the cold atom gravimeter is far smaller than the influence of the vibration controlled by the PID control method on the gravity measurement phase angle of the cold atom gravimeter, so that the advantage of the cold atom gravimeter active vibration isolation control method based on the nominal model disclosed by the invention is far superior to that of other control methods.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above examples are only for describing the preferred embodiments of the present invention, and are not intended to limit the scope of the present invention, and various modifications and improvements made to the technical solution of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.