CN115857322A - Fractional order fluid control valve system parameter identification method based on gradient iteration algorithm - Google Patents

Fractional order fluid control valve system parameter identification method based on gradient iteration algorithm Download PDF

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CN115857322A
CN115857322A CN202210851565.5A CN202210851565A CN115857322A CN 115857322 A CN115857322 A CN 115857322A CN 202210851565 A CN202210851565 A CN 202210851565A CN 115857322 A CN115857322 A CN 115857322A
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control valve
fluid control
fractional order
valve system
fractional
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李俊红
张泓睿
顾菊平
华亮
严俊
肖康
蒋一哲
白贵祥
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Nantong University
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Abstract

The invention provides a method for identifying parameters of a fractional order fluid control valve system based on a gradient iterative algorithm, belongs to the technical field of identification of fluid control valve systems, and solves the problem of low identification precision of the parameters of the fractional order fluid control valve system. The technical scheme is as follows: a method for identifying a fractional order fluid control valve system based on a gradient iterative algorithm comprises the following steps: step 1) establishing a fractional order fluid control valve system Wiener nonlinear model; and 2) constructing an identification process of the gradient iterative algorithm. The invention has the beneficial effects that: the gradient iterative algorithm provided by the invention has higher convergence speed and higher convergence precision, and can be better suitable for modeling and parameter identification of a fractional order fluid control valve system.

Description

Fractional order fluid control valve system parameter identification method based on gradient iteration algorithm
Technical Field
The invention relates to the technical field of fluid control valve system identification, in particular to a fractional order fluid control valve system parameter identification method based on a gradient iterative algorithm.
Background
With the rapid development of science and technology, industrial processes will inevitably put more stringent and urgent demands on the control of actual production processes. In order to meet such control requirements and achieve better control effects, accurate and effective mathematical models must be established for the actual production process. The actual production process almost involves the control of gas or liquid, so that the fluid control valve is indispensable in a control system, which is an important link constituting an industrial automation system. Fluid control valves are mechanical devices for controlling the state of fluid flow (pressure, flow, cut-off/on), and due to their nonlinear flow characteristics, modeling them has become a significant difficulty in production control. To better analyze and predict the production process, it is necessary to build an accurate system model for the fluid control valve while identifying the parameters of the built model. For this reason, researchers have proposed different identification methods, such as: random gradient algorithm, newton iterative algorithm, particle swarm algorithm and the like.
The random gradient algorithm has the problems of low convergence speed and low identification precision in parameter identification; the Newton iteration algorithm is an iteration algorithm, an inverse matrix of a Hessian matrix of an objective function needs to be solved in each step, the calculation is complex, and the occupied memory is large; although the particle swarm algorithm serving as the swarm intelligence algorithm can be well applied to different working conditions, the selection of genetic operators is troublesome sometimes, and the problem of low identification precision exists.
How to solve the above technical problems is the subject of the present invention.
Disclosure of Invention
The invention aims to provide a method for identifying parameters of a fractional order fluid control valve system based on a gradient iterative algorithm, which has higher convergence speed and higher convergence precision and can be better suitable for modeling and parameter identification of the fractional order fluid control valve system.
The invention is realized by the following measures: the method for identifying the parameters of the fractional order fluid control valve system based on the gradient iterative algorithm specifically comprises the following steps:
step 1) establishing an input and output mathematical model of a fractional order fluid control valve system.
And 2) constructing an identification process of the gradient iterative algorithm.
As a further optimization scheme of the method for identifying the parameters of the fractional order fluid control valve system based on the gradient iterative algorithm, the specific modeling step of the step 1) is as follows:
(1-1) constructing a structure of a fractional order fluid control valve system Wiener nonlinear model.
(1-2) according to the model, constructing a fractional order fluid control valve system Wiener nonlinear model expression as follows:
Figure BDA0003753737290000021
Figure BDA0003753737290000022
e(t)=D(z)v(t), (3)
y(t)=x(t)+e(t), (4)
the meaning of each symbol in the above formula: u (t) is the model input signal, y (t) is the model output signal, v (t) is a mean of 0 and a variance of σ 2 And white noise satisfying a Gaussian distribution, the intermediate variables u (t), x (t) and e (t) being signals immeasurable in the middle, z -1 Is the unit delay symbol: z is a radical of formula -1 y (t) = y (t-1), a (z), B (z) and D (z) are constant polynomials with the following definitions:
Figure BDA0003753737290000023
Figure BDA0003753737290000024
Figure BDA0003753737290000025
wherein the polynomial factor a i ,b j And d l Is the parameter to be estimated, α i ,β j And gamma l Is the fractional order of the polynomial denominator. The present invention contemplates a fractional order system, i.e., the fractional order is a multiple of the same base and is known:
Figure BDA0003753737290000026
(1-3) intermediate signal
Figure BDA0003753737290000027
And e (t) can be expressed as:
Figure BDA0003753737290000028
Figure BDA0003753737290000029
simplifying to obtain:
Figure BDA00037537372900000210
Figure BDA00037537372900000211
the invention adopts Gr unwald Letnikov (GL) definition to solve fractional order derivative, and the GL definition can be expressed as:
Figure BDA0003753737290000031
where Δ is the discrete fractional order difference operator, Δ α m (kh) is the alpha fractional derivative of the function m (k), which can be given as t = kh, where h is the sampling interval and k is the number of samples to compute the derivative approximation. Substituting equation (7) into equations (5) and (6), the intermediate signal after dispersion
Figure BDA0003753737290000032
And e (t) can be rewritten as:
Figure BDA0003753737290000033
Figure BDA0003753737290000034
the output of the nonlinear element in the model is in a polynomial form, which can be expressed as:
Figure BDA0003753737290000035
wherein p is i Is an unknown coefficient to be identified and the order r of the polynomial function is known. To ensure the uniqueness of the parameters, let the first modulus p of the non-linear component 1 =1。
(1-4) obtaining an identification model of a Wiener nonlinear model of a fractional order fluid control valve system:
Figure BDA0003753737290000036
in the above-mentioned formula,
Figure BDA0003753737290000037
is a systematic information vector, represented as:
Figure BDA0003753737290000038
wherein,
Figure BDA0003753737290000039
are respectively defined as
Figure BDA00037537372900000310
Figure BDA00037537372900000311
Figure BDA00037537372900000312
θ is the parameter vector of the system, expressed as: θ = [ θ = 1 T2 T3 T ] T
Wherein, theta 1 ,θ 2 ,θ 3 Are respectively defined as:
Figure BDA0003753737290000041
θ 2 =[p 2 ,p 3 ,…,p r ] T ,
Figure BDA0003753737290000042
the method for identifying parameters of the Wiener nonlinear model of the fractional order fluid control valve system based on the gradient iterative algorithm is further designed in that the step 2) is specifically as follows:
step 2-1) initialization, given iteration times k max Data length N;
step 2-2) using the pneumatic control signal of the valve as input data u (t) of a fractional order fluid control valve system model) Fluid flow as output data y (t) and valve plug position as intermediate signal
Figure BDA0003753737290000043
Step 2-3) defining a stacking output vector Y (N) according to the input and output data, and defining a stacking information matrix psi (N) as a formula (12);
Figure BDA0003753737290000044
step 2-4) defining a criterion function J (theta) as
Figure BDA0003753737290000045
Wherein,
Figure BDA0003753737290000046
is an estimate of the pile-up information matrix, and->
Figure BDA0003753737290000047
Is an estimate of the parameter vector; />
Step 2-5) intermediate variables in the information vector
Figure BDA0003753737290000048
Fractional derivative of an intermediate variable->
Figure BDA0003753737290000049
And fractional order derivative of the undetectable noise Δ α v (t) is replaced by its evaluation value>
Figure BDA00037537372900000410
And &>
Figure BDA00037537372900000411
Calculating an estimate ≥ of the information vector according to equation (14)>
Figure BDA00037537372900000412
Construction according to equation (15)>
Figure BDA00037537372900000413
Figure BDA00037537372900000414
Figure BDA00037537372900000415
Step 2-6) selecting a suitable convergence factor mu according to formula (16) k
Figure BDA00037537372900000416
Step 2-7) calculating the estimated value of the parameter vector according to the formula (17)
Figure BDA0003753737290000051
Figure BDA0003753737290000052
Step 2-8) calculating the estimated intermediate variables according to the equations (8), (18)
Figure BDA0003753737290000053
And the estimated noise->
Figure BDA0003753737290000054
The fractional derivative { (R) } of the noise and the intermediate variable estimated is calculated as defined by GL of equation (7)>
Figure BDA0003753737290000055
Figure BDA0003753737290000056
Step 2-9) judging whether the maximum iteration times are reached, if not, skipping the program to step 2-5), and if so, entering step 2-10);
and 2-10) outputting a result to finish identification.
Compared with the prior art, the invention has the beneficial effects that:
(1) The method establishes a model for identifying the parameters of the fractional order Wiener nonlinear system of the fluid control valve, takes a pneumatic control signal of the valve as input data, and identifies the parameters of the model by using a gradient iterative algorithm; it can be seen from fig. 4 that the algorithm can identify the internal parameters of the model well.
(2) Compared with a random gradient algorithm, the gradient iteration algorithm uses all data available for the system in each iteration process, updates intermediate variables and noise in each iteration process so as to obtain an estimated information vector, improves the convergence rate, can better identify a nonlinear system, has higher identification precision and obtains smaller estimation error; meanwhile, the identification method has better applicability to a fractional order fluid control valve Wiener nonlinear model.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention.
Fig. 1 is an overall flowchart of a fractional order fluid control valve Wiener nonlinear system identification method based on a gradient iterative algorithm provided by the invention.
Fig. 2 is a schematic structural diagram of the fractional order fluid control valve provided by the present invention, which mainly comprises a displacement sensor, magnetic steel, an electromagnetic linear actuator, a mushroom valve, a valve seat, and a valve body upper cover fixed on a central shaft center, wherein one side of the valve body is provided with a fluid inlet connected with an external gas supply pipeline.
Fig. 3 is a schematic diagram of a general model of an input/output system of the fractional-order fluid control valve parameter identification method based on the gradient iterative algorithm provided by the invention.
FIG. 4 is a schematic diagram of the error between the identification parameter and the true value according to the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. Of course, the specific embodiments described herein are merely illustrative of the invention and are not intended to be limiting.
Example 1
Referring to fig. 1 to 4, the present embodiment provides a technical solution of a method for identifying parameters of a fractional order fluid control valve system based on a gradient iterative algorithm, which includes the following specific steps:
step 1) establishing an input and output mathematical model of a fractional order fluid control valve system.
And 2) constructing an identification process of the gradient iterative algorithm.
As a further optimization scheme of the identification method for the fractional order fluid control valve system based on the gradient iterative algorithm provided by this embodiment, the specific modeling steps of step 1) are as follows:
(1-1) constructing a structure of a fractional order fluid control valve system Wiener nonlinear model.
(1-2) according to the model, constructing a fractional order fluid control valve system Wiener nonlinear model expression as follows:
Figure BDA0003753737290000061
Figure BDA0003753737290000062
e(t)=D(z)v(t), (3)
y(t)=x(t)+e(t), (4)
the meaning of each symbol in the above formula: u (t) is the model input signal, y (t) is the model output signal, v (t) is a mean of 0 and a variance of σ 2 And white noise, an intermediate variable, satisfying Gaussian distribution
Figure BDA0003753737290000063
x (t) and e (t) are signals which are not measurable in the middle, z -1 Is the unit delay symbol: z is a radical of -1 y (t) = y (t-1), a (z), B (z) and D (z) are constant polynomials with the following definitions:
Figure BDA0003753737290000064
Figure BDA0003753737290000065
Figure BDA0003753737290000066
wherein the polynomial factor a i ,b j And d l Is the parameter to be estimated, α i ,β j And gamma l Is the fractional order of the polynomial denominator. The present embodiment considers a fractional order system, i.e. the fractional order is a multiple of the same base and is known:
Figure BDA0003753737290000067
(1-3) intermediate signal
Figure BDA0003753737290000068
And e (t) can be expressed as: />
Figure BDA0003753737290000071
Figure BDA0003753737290000072
Simplifying to obtain:
Figure BDA0003753737290000073
Figure BDA0003753737290000074
this example uses the Gr ü nwald Letnikov (GL) definition to solve for fractional derivatives, which can be expressed as:
Figure BDA0003753737290000075
where Δ is the discrete fractional order difference operator, Δ α m (kh) is the fractional derivative of the order a of the function m (k), and it is possible to let t = kh, where h is the sampling interval and k is the number of samples to which the derivative approximation is calculated. Substituting equation (7) into equations (5) and (6), the intermediate signal after dispersion
Figure BDA0003753737290000076
And e (t) can be rewritten as:
Figure BDA0003753737290000077
Figure BDA0003753737290000078
the output of the nonlinear element in the model is in a polynomial form, which can be expressed as:
Figure BDA0003753737290000079
wherein p is i Is an unknown coefficient to be identified and the order r of the polynomial function is known. To ensure the uniqueness of the parameters, let the first modulus p of the non-linear component 1 =1。
(1-4) obtaining an identification model of a Wiener nonlinear model of a fractional order fluid control valve system:
Figure BDA0003753737290000081
in the above-mentioned formula,
Figure BDA0003753737290000082
is a systematic information vector, represented as:
Figure BDA0003753737290000083
wherein,
Figure BDA0003753737290000084
are respectively defined as
Figure BDA0003753737290000085
Figure BDA0003753737290000086
Figure BDA0003753737290000087
θ is a parameter vector of the system, expressed as: θ = [ θ = 1 T2 T3 T ] T
Wherein, theta 1 ,θ 2 ,θ 3 Are respectively defined as:
Figure BDA0003753737290000088
θ 2 =[p 2 ,p 3 ,…,p r ] T ,
Figure BDA0003753737290000089
preferably, the model of step 1) is a fractional Wiener nonlinear model.
Preferably, the step 2) of constructing the identification process of the gradient iterative algorithm includes the following specific steps:
step 2-1) initialization, given iteration times k max Data length N;
step 2-2) taking a pneumatic control signal of the valve as input data u (t) of a fractional order fluid control valve system model, taking fluid flow as output data y (t), and taking the position of the valve plug as an intermediate signal
Figure BDA00037537372900000811
Step 2-3) defining a stacking output vector Y (N) according to the input and output data, and defining a stacking information matrix psi (N) as a formula (12);
Figure BDA00037537372900000810
step 2-4) defining a criterion function J (theta) as
Figure BDA0003753737290000091
Wherein,
Figure BDA0003753737290000092
is an estimate of the pile-up information matrix, and->
Figure BDA0003753737290000093
Is an estimate of the parameter vector;
step 2-5) intermediate variables in the information vector
Figure BDA0003753737290000094
Fractional derivatives of intermediate variables
Figure BDA0003753737290000095
And fractional derivative of the undetectable noise Δ α v (t) is replaced by its evaluation value>
Figure BDA0003753737290000096
And &>
Figure BDA0003753737290000097
Calculating an estimate ≥ of the information vector according to equation (14)>
Figure BDA0003753737290000098
Construction according to equation (15)>
Figure BDA0003753737290000099
Figure BDA00037537372900000910
Figure BDA00037537372900000911
Step 2-6) selecting a suitable convergence factor mu according to the formula (16) k
Figure BDA00037537372900000912
Step 2-7) calculating the estimated value of the parameter vector according to the formula (17)
Figure BDA00037537372900000913
Figure BDA00037537372900000914
Step 2-8) calculating the estimated intermediate variables according to the equations (8), (18)
Figure BDA00037537372900000915
And the estimated noise->
Figure BDA00037537372900000916
The fractional derivative { (R) } of the noise and the intermediate variable estimated is calculated as defined by GL of equation (7)>
Figure BDA00037537372900000917
Figure BDA00037537372900000918
Step 2-9) judging whether the maximum iteration times are reached, if not, skipping the program to step 2-5), and if so, entering step 2-10);
and 2-10) outputting a result to finish identification.
The schematic of the fractional order fluid control valve system employed in this embodiment is shown in fig. 2. Wherein u (t) is a pneumatic control signal of the valve,
Figure BDA00037537372900000919
is the valve plug position, x (t) is the estimated fluid flow, and y (t) is the actual fluid flow.
With the above-mentioned fractional Wiener model, the following model can be established for the present embodiment:
Figure BDA00037537372900000920
Figure BDA00037537372900000921
e(t)=(1+d 1 z )v(t)=(1+0.1z -0.3 )v(t),
y(t)=x(t)+e(t),
comparing the above model with step 1), it is possible to obtain
a 1 =0.2,a 2 =0.4,b 1 =0.3,b 2 =0.5,p 2 =1,d 1 =0.1,
For the above model, a criterion function J (θ) is determined for use in the gradient iteration algorithm, the criterion function being defined as follows:
Figure BDA0003753737290000101
wherein Y (N) is a pile-up output vector,
Figure BDA0003753737290000102
is an estimate of the pile-up information matrix, and->
Figure BDA0003753737290000103
Is an estimate of the parameter vector;
in order to conveniently substitute the parameters to be identified into the gradient iterative algorithm, the parameters to be identified are formed into a parameter vector θ, and the parameters to be identified are as follows:
θ=[a 1 ,a 2 ,b 1 ,b 2 ,p 2 ,d 1 ] T ,
initializing according to step 2-1), and giving iteration times k max Data length N;
obtaining input and output data of the fractional order fluid control valve system model according to the step 2-2), and calculating the position of the valve plug
Figure BDA00037537372900001010
Defining a stacking output vector Y (N) and a stacking information matrix psi (N) according to the step 2-3);
obtaining a criterion function J (theta) according to the step 2-4);
calculating an estimated value of the information vector according to step 2-5)
Figure BDA0003753737290000104
Evaluation value for constructing accumulation information matrix>
Figure BDA0003753737290000105
Selecting a proper convergence factor mu according to the step 2-6) k
Updating the estimated value of the parameter vector according to the step 2-7)
Figure BDA0003753737290000106
Calculating estimated intermediate variables according to steps 2-8)
Figure BDA0003753737290000107
And the estimated noise->
Figure BDA0003753737290000108
Calculating a fractional order derivative of the estimated intermediate variable and noise ≧>
Figure BDA0003753737290000109
And (5) completing circulation according to the steps 2-9) and 2-10) and outputting a result.
Wherein, the convergence factor mu is set k And data length N, several considerations need to be taken into account: the too small convergence factor can cause too large identification error and fail to obtain accurate identification result; too large a convergence factor may result in a fluctuating recognition result and a non-converged recognition result. The problem of low identification precision is caused by unsatisfactory identification result due to the fact that the data length is too small; too large data length will cause a problem of large calculation amount.
The parameter identification result performed by using the fractional order fluid control valve system parameter identification method based on the gradient iterative algorithm of the present embodiment is shown in fig. 4; the identification method is high in identification precision, the estimated value of the parameter to be identified is very close to the true value, and meanwhile, the identification method is good in applicability to parameter identification of the fractional order fluid control valve model.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims (3)

1. The method for identifying the parameters of the fractional order fluid control valve system based on the gradient iterative algorithm is characterized by comprising the following steps of:
step 1) establishing an input and output mathematical model of a fractional order fluid control valve system;
and 2) constructing an identification process of the gradient iterative algorithm.
2. The gradient iterative algorithm-based fractional order fluid control valve system identification method of claim 1, wherein the step 1) comprises the steps of:
(1-1) constructing a structure of a fractional order fluid control valve system Wiener nonlinear model;
(1-2) constructing a fractional order fluid control valve system Wiener nonlinear model expression according to the Wiener nonlinear model obtained in the step (1-1) as follows:
Figure QLYQS_1
Figure QLYQS_2
e(t)=D(z)v(t), (3)
y(t)=x(t)+e(t), (4)
where u (t) is the model input signal, y (t) is the model output signal, and v (t) is a mean of 0 and a variance of σ 2 And white noise, an intermediate variable, satisfying Gaussian distribution
Figure QLYQS_3
x (t) and e (t) are signals which are not measurable in the middle, z -1 Is the unit delay symbol: z is a radical of -1 y (t) = y (t-1), a (z), B (z) and D (z) are constant polynomials with the following definitions:
Figure QLYQS_4
Figure QLYQS_5
Figure QLYQS_6
wherein the polynomial factor a i ,b j And d l Is the parameter to be estimated, α i ,β j And gamma l Is the fractional order of the polynomial denominator, the present invention considers fractional fit systems, i.e. the fractional order is a multiple of the same base and is known:
Figure QLYQS_7
(1-3) intermediate signal
Figure QLYQS_8
And e (t) is expressed as:
Figure QLYQS_9
Figure QLYQS_10
simplifying to obtain:
Figure QLYQS_11
Figure QLYQS_12
the invention adopts Gr unwald Letnikov (GL) definition to solve fractional derivative, wherein the GL definition is as follows:
Figure QLYQS_13
where Δ is the discrete fractional order difference operator, Δ α m (kh) is the alpha fractional derivative of the function m (k) with t = kh, where h is the sampling interval and k is the number of samples to calculate the derivative approximation, substituting equation (7) into equations (5), (6), the intermediate signal after discretization
Figure QLYQS_14
And e (t) rewritten as:
Figure QLYQS_15
Figure QLYQS_16
the output of the nonlinear element in the model is in polynomial form and is expressed as:
Figure QLYQS_17
wherein p is i Is an unknown coefficient to be identified, and the order r of the polynomial function is known, in order to ensure the uniqueness of the parameter, let the first modulus p of the nonlinear component 1 =1;
(1-4) obtaining an identification model of a Wiener nonlinear model of a fractional order fluid control valve system:
Figure QLYQS_18
in the above-mentioned formula,
Figure QLYQS_19
is a systematic information vector, represented as:
Figure QLYQS_20
wherein,
Figure QLYQS_21
are respectively defined as
Figure QLYQS_22
Figure QLYQS_23
Figure QLYQS_24
θ is the parameter vector of the system, expressed as: θ = [ θ = 1 T2 T3 T ] T
Wherein, theta 1 ,θ 2 ,θ 3 Are respectively defined as:
Figure QLYQS_25
θ 2 =[p 2 ,p 3 ,…,p r ] T ,
Figure QLYQS_26
3. the gradient iterative algorithm-based method for identifying parameters of a Wiener nonlinear model of a fractional order fluid control valve system according to claim 1, wherein the step 2) comprises the steps of:
step 2-1) initialization, given iteration times k max Data length N;
step 2-2) taking a pneumatic control signal of the valve as input data u (t) of a fractional order fluid control valve system model, taking fluid flow as output data y (t), and taking the position of the valve plug as an intermediate signal
Figure QLYQS_27
Step 2-3) defining a stacking output vector Y (N) according to the input and output data, and defining a stacking information matrix psi (N) as a formula (12);
Figure QLYQS_28
step 2-4) defining a criterion function J (theta) as
Figure QLYQS_29
Wherein,
Figure QLYQS_30
is an estimate of the pile-up information matrix, and->
Figure QLYQS_31
Is an estimate of the parameter vector;
step 2-5) intermediate variables in the information vector
Figure QLYQS_32
Fractional derivative of an intermediate variable->
Figure QLYQS_33
And fractional derivative of the undetectable noise Δ α v (t) is replaced by its evaluation value>
Figure QLYQS_34
And &>
Figure QLYQS_35
Calculating an estimate ≥ of the information vector according to equation (14)>
Figure QLYQS_36
Construction according to equation (15)>
Figure QLYQS_37
Figure QLYQS_38
Figure QLYQS_39
Step 2-6) selecting a suitable convergence factor mu according to formula (16) k
Figure QLYQS_40
Step 2-7) calculating the estimated value of the parameter vector according to the formula (17)
Figure QLYQS_41
Figure QLYQS_42
Step 2-8) calculating the estimated intermediate variables according to the equations (8), (18)
Figure QLYQS_43
And the estimated noise->
Figure QLYQS_44
The fractional derivative { (R) } of the noise and the intermediate variable estimated is calculated as defined by GL of equation (7)>
Figure QLYQS_45
Figure QLYQS_46
Step 2-9) judging whether the maximum iteration times are reached, if not, skipping the program to step 2-5), and if so, entering step 2-10);
and 2-10) outputting a result to finish identification.
CN202210851565.5A 2022-07-19 2022-07-19 Fractional order fluid control valve system parameter identification method based on gradient iteration algorithm Pending CN115857322A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115033838A (en) * 2022-06-27 2022-09-09 南通大学 Fractional order water tank identification method based on forgetting augmentation random gradient algorithm

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115033838A (en) * 2022-06-27 2022-09-09 南通大学 Fractional order water tank identification method based on forgetting augmentation random gradient algorithm
CN115033838B (en) * 2022-06-27 2024-06-25 南通大学 Fractional order water tank identification method based on forgetting augmentation random gradient algorithm

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