An intelligent valve positioner system and control method based on active disturbance rejection control

Abstract

The present invention discloses an intelligent valve positioner system and control method based on self-anti-disturbance control, which relates to the technical field of industrial automation instruments, including a tracking differentiator, an extended state observer, a nonlinear feedback controller and an intelligent valve positioner. By collecting valve stem feedback voltage signals and output control signals, the tracking differentiator and the extended state observer are used to estimate the sum of the system model error part and the unknown disturbance part, and feedback compensation is performed to reduce the dependence on the model, improve the anti-disturbance ability, and use a nonlinear feedback controller combined with a nonlinear error combination to realize closed-loop control of the valve nonlinearity. The present invention improves the control performance, anti-disturbance performance and robustness of the intelligent valve positioner.

Description

Technical Field

[0001] The present invention relates to the technical field of industrial automation instruments, and more particularly to an intelligent valve positioner system and a control method based on auto-anti-disturbance control. Background Art

[0002] With the development of industrial automation in my country, the position of industrial production automatic control (referred to as process control) in the national economy has become increasingly prominent. The quality of process control depends largely on the performance of process control instruments, which include sensors, control units, actuators and various auxiliary devices. The actuator consists of two parts: the actuator and the regulating mechanism. According to the different driving forms, it can be divided into three categories: pneumatic, hydraulic and electric. Among them, the pneumatic actuator uses compressed air as the power source. It has the advantages of simple structure, low price, fireproof and explosion-proof, and environmental protection. It is widely used in chemical, energy, oil and gas, water treatment, papermaking and other fields, occupying more than 60% of the market share.

[0003] Due to the existence of nonlinear factors such as air compressibility and friction, as well as differences in system model parameters caused by differences in pneumatic control valves, installation and processing, the precise control of the valve positioner system of the pneumatic actuator becomes particularly complex. When faced with the nonlinear characteristics and parameter differences of the valve positioner system, traditional control strategies often find it difficult to achieve self-tuning of control parameters and high-performance control, resulting in poor control performance, low control accuracy, slow dynamic response, large overshoot, and long stabilization time.

[0004] Therefore, how to improve the control performance of the valve positioner system is an urgent problem to be solved by those skilled in the art. Summary of the invention

[0005] In view of this, the present invention provides an intelligent valve positioner system and control method based on active anti-disturbance control, which realizes precise positioning of the pneumatic control valve by collecting valve position feedback voltage signals and outputting control signals and combining nonlinear combinations of errors.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] An intelligent valve positioner system based on active disturbance rejection control includes a tracking differentiator, an extended state observer, a nonlinear feedback controller and an intelligent valve positioner;

[0008] The tracking differentiator sets a transition process v1 according to a set reference signal v0, and extracts a differential signal v2 from the intelligent valve positioner;

[0009] The extended state observer receives the actual control signal u and the feedback signal x, calculates the tracking signal z1 and the differential signal z2 of the feedback signal x, and calculates the disturbance sum z3 including the error part and the position disturbance part according to the actual control signal u and the feedback signal x in combination with the intelligent valve positioner model corresponding to the intelligent valve positioner; and compensates the disturbance sum z3 to the feedback control signal u0;

[0010] The nonlinear feedback controller calculates a transient state error e1=v1-z1 and a differential signal state error e2=v2-z2, and calculates a feedback control signal u0 using a nonlinear combination of the transient state error and the differential signal state error;

[0011] The intelligent valve positioner collects the actual control signal u and the feedback signal x and transmits them to the extended state observer, and receives the feedback control signal u0 and generates an anti-disturbance control signal in combination with the actual control signal u, and performs automatic control adjustment according to the anti-disturbance control signal.

[0012] The technical effect of the above technical solution is that the differential tracker has a certain filtering effect on the high-frequency interference of the reference signal v0; the extended state observer compensates z3 to the feedback control signal u0, and jointly determines the final actual control quantity u, which can transform the complex intelligent valve positioner into a pure integral series system composed of two integrators with the feedback control signal u0 and the actual control quantity u as control signals at the same time.

[0013] Preferably, the intelligent valve positioner includes an IP component, a valve position feedback mechanism, a pneumatic amplifier, a pneumatic diaphragm actuator, a valve and a controller; wherein the controller receives control signals and feedback signals and performs control operations, generates control signals and converts them into current control signals for transmission to the IP component; the torque motor in the IP component generates an electromagnetic torque of corresponding magnitude to drive the nozzle baffle to move, and changes the size of the nozzle by controlling the distance between the baffle and the nozzle, thereby adjusting the back pressure chamber pressure of the pneumatic amplifier; the pneumatic amplifier compares the air pressure values ​​in each mold cavity, amplifies the small pressure signal into a large pressure signal, and uses the large pressure signal to drive the pneumatic diaphragm actuator to realize the conversion of air pressure into the displacement of the valve stem of the valve.

[0014] Preferably, the actual control signal u is the excitation current I output to the IP component, and the feedback signal x is the valve stem feedback voltage signal V.

[0015] Preferably, a current acquisition and conditioning circuit is used to acquire the excitation current, and a valve position feedback voltage acquisition circuit is used to acquire the valve stem feedback voltage signal; the valve stem feedback voltage signal is normalized and then transmitted to the expansion state observer as a feedback signal x.

[0016] A control method for an intelligent valve positioner system based on active disturbance rejection control comprises the following steps:

[0017] Step 1: Construct an intelligent valve positioner model under an ideal gas environment;

[0018] Step 2: The tracking differentiator sets the transition process v1 according to the set reference signal v0, and extracts the differential signal v2 from the smart valve positioner;

[0019] Step 3: Collect the actual control signal u input to the intelligent valve positioner and the feedback signal x of the intelligent valve positioner, calculate the tracking signal z1 and the differential signal z2 of the feedback signal x by the extended state observer, and calculate the disturbance sum z3 in combination with the intelligent valve positioner model;

[0020] Step 4: The nonlinear feedback controller calculates the transition state error and the differential signal state error according to the transition process v1, the differential signal v2, the tracking signal z1 and the differential signal z2, calculates the feedback control signal u0 through the nonlinear combination of the transition state error and the differential signal state error, and compensates the disturbance sum z3 to the feedback control signal u0;

[0021] Step 5: Adjust the intelligent valve positioner according to the feedback control signal u0.

[0022] Preferably, the intelligent valve positioner includes an IP component, a valve position feedback mechanism, a pneumatic amplifier, a pneumatic diaphragm actuator, a valve and a controller; the specific process of step 1 is:

[0023] Step 11: Construct the zero-order steady-state model of the IP component and the zero-order steady-state model of the pneumatic amplifier;

[0024] Input linearly increasing and decreasing driving current in the range of 0-1mA into the intelligent valve positioner, and record the excitation current I and back pressure chamber pressure P in steady state. b and output pressure P out , fitting the recorded data, and obtaining the excitation current I and the back pressure chamber pressure P b , excitation current I and output pressure P out are linearly related, so the back pressure chamber pressure P b and output pressure P out It is a linear relationship, and the zero-order steady-state model of the IP component is expressed as:

[0025] P b =0.15I-0.009;

[0026] The IP component and the pneumatic amplifier are in series relationship. The zero-order steady-state model of the IP component and the zero-order steady-state model of the pneumatic amplifier are combined in series to obtain the excitation current I and the output pressure P out The linear relationship is expressed as:

[0027] Pout =1.7I-0.525;

[0028] According to the zero-order steady-state model of the IP component, the excitation current I and the output pressure P out The linear relationship between and is obtained, and the zero-order steady-state model of the pneumatic amplifier is obtained, which is expressed as:

[0029] P out =11.87P b -0.421;

[0030] Step 12: Construct the motion model of the pneumatic diaphragm actuator;

[0031] The balance equation of valve stem motion of pneumatic diaphragm actuator is:

[0032] F P =F0+F k +F f +F g

[0033] Among them, F P Indicates the output pressure P at the diaphragm out The upward thrust generated; F0 represents the downward pressure generated by the atmospheric pressure P0 at the diaphragm; F k Indicates spring force; F f Indicates the friction of moving parts; F g Represents the total weight of the moving parts;

[0034] The motion model of the pneumatic diaphragm actuator is expressed as a second-order motion equation:

[0035]

[0036] Wherein, c is the velocity damping coefficient of the valve stem; n is the number of springs in the pneumatic diaphragm actuator; k is the elastic coefficient of the spring; L is the relative displacement; Ae is the effective area of ​​the diaphragm;

[0037] Step 13: Construct the valve position feedback mechanism model, expressed as:

[0038]

[0039] Wherein, V represents the valve stem feedback voltage signal; is a constant, R represents the radius of the large gear of the valve position feedback mechanism, r represents the radius of the small gear of the valve position feedback mechanism, and n represents the conversion accuracy;

[0040] Step 14: Construct an intelligent valve positioner model based on the zero-order steady-state model of the IP component, the zero-order steady-state model of the pneumatic amplifier, the motion model of the pneumatic diaphragm actuator, and the valve position feedback mechanism model.

[0041] Through the above technical solutions, it can be known that compared with the prior art, the present invention discloses a control method for an intelligent valve positioner based on self-disturbance rejection control. In view of the nonlinearity of the valve positioner system, it is difficult to establish its accurate mathematical model and to perform parameter self-tuning. At the same time, in order to improve the control performance, anti-disturbance performance and robustness of the valve positioner, the present invention applies the self-disturbance rejection control technology with high robustness and anti-disturbance and independent of the system model to the intelligent valve positioner. By collecting the valve position feedback voltage signal and the output control signal, the tracking differentiator and the extended state observer are used to estimate the sum of the system model error part and the unknown disturbance part, and feedback compensation is performed to reduce the dependence on the model and improve the anti-disturbance ability. In addition, the nonlinear feedback controller is combined with the nonlinear error combination to realize the closed-loop control of the valve nonlinearity, improve the control performance, anti-disturbance performance and robustness of the intelligent valve positioner, avoid the dependence of the traditional algorithm on the system model, and solve the contradiction between the rapidity and overshoot of the traditional PID algorithm. At the same time, the system structure of the present invention is simple, which is convenient for application and implementation in the intelligent valve positioner. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0043] Figure 1 A schematic diagram of an intelligent valve positioner system based on active disturbance rejection control provided by the present invention;

[0044] Figure 2 A schematic diagram of the structure of an intelligent valve positioner system based on active disturbance rejection control in an embodiment of the present invention;

[0045] Figure 3 A schematic diagram of the structure of the intelligent valve positioner provided by the present invention;

[0046] Figure 4 This is a schematic diagram of the starting film actuator and valve structure provided by the present invention.

[0047] In the accompanying drawings: 1-return spring, 2-upper diaphragm cover, 3-diaphragm, 4-lower diaphragm cover, 5-valve stem, 6-sealing packing, 7-valve core, 8-valve seat. DETAILED DESCRIPTION

[0048] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] The embodiment of the present invention discloses an intelligent valve positioner system based on active disturbance rejection control, such as Figure 1 As shown, it includes a tracking differentiator, an extended state observer, a nonlinear feedback controller and an intelligent valve positioner; the tracking differentiator arranges a transition process v1 according to a set reference signal v0, extracts a differential signal v2, and has a certain filtering effect on the high-frequency interference of v0; the extended state observer receives the actual control signal u and the feedback signal x, calculates the tracking signal z1 and the differential signal z2 of the feedback signal x, and the disturbance sum z3 of the error part and the position disturbance part calculated by the intelligent valve positioner model corresponding to the actual control signal u and the feedback signal x; the disturbance sum z3 is compensated to the feedback control signal u0, The final actual control quantity u is jointly determined, and the complex system can be converted into a pure integral series system consisting of two integrators with the feedback control signal u0 as the control signal; the nonlinear feedback controller calculates the transition state error e1=v1-z1 and the differential signal state error e2=v2-z2, and uses the nonlinear combination of the transition state error and the differential signal state error to calculate the feedback control signal u0; the intelligent valve positioner collects the actual control signal u and the feedback signal x and transmits them to the extended state observer, and receives the feedback control signal u0 and combines it with the actual control signal u to generate an anti-disturbance control signal, and performs automatic control adjustment according to the anti-disturbance control signal.

[0050] Furthermore, intelligent valve positioners such as Figure 3 As shown, it includes an IP component (nozzle baffle type electrical conversion unit), a valve position feedback mechanism, a pneumatic amplifier, a pneumatic film actuator, a valve and a controller; wherein the controller receives the control signal and the feedback signal and performs control operations, generates a control signal and converts it into a current control signal and transmits it to the IP component; the torque motor in the IP component generates an electromagnetic torque of corresponding magnitude to drive the nozzle baffle to move, and changes the size of the nozzle by controlling the distance between the baffle and the nozzle, thereby adjusting the back pressure cavity pressure of the pneumatic amplifier; the pneumatic amplifier compares the air pressure values ​​in each cavity, and amplifies the small pressure signal into a large pressure signal. Since the diaphragm area of ​​the cavity where the output pressure is located is small and the diaphragm area of ​​the cavity where the back pressure cavity is located is large, the input of the pneumatic amplifier is a small pressure signal, which is converted into a large pressure signal by amplification to drive the pneumatic film actuator, and the large pressure signal is used to drive the pneumatic film actuator to realize the conversion of air pressure into the displacement of the valve stem of the valve, thereby controlling the valve opening.

[0051] Further, the pneumatic diaphragm actuator is connected to the valve as follows Figure 3 As shown, the pneumatic diaphragm actuator is provided with an upper diaphragm cover 2, a return spring 1, a diaphragm 3 and a lower diaphragm cover 4 from top to bottom, and also includes a valve stem 5, one end of which is fixed on the diaphragm 3 and passes through the lower diaphragm cover 4; the valve is provided with a sealing packing 6 and a valve seat 8 from top to bottom, a valve core 7 is provided in the valve seat 8, and the valve stem 5 passes through the sealing packing 6 and is connected to the valve core 7.

[0052] Furthermore, the tracking differentiator (TD), extended state observer (ESO) and nonlinear state error feedback controller (NLSEF) constitute the ADRC algorithm of the intelligent valve positioner based on the ADRC. According to the simplified model of the intelligent valve positioner, the ADRC algorithm of the intelligent valve positioner is designed. Its principle block diagram is shown in FIG. Figure 2 As shown. The actual control signal u in the ADRC algorithm is the excitation current I output to the IP component, which is acquired through the current acquisition and conditioning circuit. The feedback signal x is the valve stem feedback voltage signal V of the intelligent valve positioner, which is acquired through the valve position feedback voltage acquisition circuit. In practical applications, since the algorithm needs to process discrete signals, the corresponding discrete ADRC algorithm is as follows:

[0053]

[0054] fal() is a nonlinear function k represents the current k moment, k+1 represents the next moment, e(k) represents the difference between the observed value and the actual value at k moment, and y(k) represents the actual value at k moment; the discrete auto-disturbance rejection control algorithm shown in the above formula is programmed and applied in the controller circuit board of the intelligent valve positioner. In order to meet the requirement of step size h=0.001s, the clock interrupt frequency of entering the auto-disturbance rejection control subroutine is set to 1kHz, and the normalized valve stem feedback voltage signal V is used as the feedback signal participating in the auto-disturbance rejection control algorithm operation, thereby realizing the full stroke control of pneumatic control valves with different strokes under the control of the auto-disturbance rejection control algorithm.

[0055] On the other hand, in a specific embodiment, a control method of an intelligent valve positioner system based on active disturbance rejection control includes the following steps:

[0056] S1: Constructing the intelligent valve positioner model under ideal gas environment;

[0057] S2: The tracking differentiator arranges the transition process v1 according to the set reference signal v0, and extracts the differential signal v2 from the intelligent valve positioner;

[0058] S3: Collect the actual control signal u of the input intelligent valve positioner and the feedback signal x of the intelligent valve positioner, the extended state observer calculates the tracking signal z1 and the differential signal z2 of the feedback signal x, and calculates the disturbance sum z3 in combination with the intelligent valve positioner model;

[0059] S4: The nonlinear feedback controller calculates the transition state error and the differential signal state error according to the transition process v1, the differential signal v2, the tracking signal z1 and the differential signal z2, calculates the feedback control signal u0 through the nonlinear combination of the transition state error and the differential signal state error, and compensates the disturbance sum z3 to the feedback control signal u0;

[0060] S5: Adjust the intelligent valve positioner according to the feedback control signal u0.

[0061] Furthermore, relative to the action process of the membrane actuator, the torque motor in the IP component converts electrical energy into magnetic field energy, the nozzle baffle generates electromagnetic torque in the magnetic field, and the nozzle baffle swings slightly in the electromagnetic torque, spring torque, jet torque, damping torque, and the change in air pressure can all be considered to be completed instantly. At the same time, the movement of the valve stem in the pneumatic amplifier is also small, with a very fast response speed. Therefore, the relationship between the excitation current and the back pressure chamber pressure of the IP component, and the relationship between the back pressure chamber pressure and the output pressure in the pneumatic amplifier can be simplified to a steady-state model. Therefore, the model of the IP component can be directly established through the steady-state relationship between the excitation current and the back pressure chamber pressure, and the model of the pneumatic amplifier can be established through the steady-state relationship between the back pressure chamber pressure and the output pressure in the pneumatic amplifier; the specific process of S1 is:

[0062] S11: Construct the zero-order steady-state model of IP component and the zero-order steady-state model of pneumatic amplifier;

[0063] Input linear increasing and linear decreasing driving current in the range of 0-1mA into the intelligent valve positioner, and record the excitation current I and back pressure chamber pressure P in steady state. b , output pressure P out The size of the back pressure chamber is obtained by fitting the test data to obtain the excitation current I and the back pressure chamber pressure P b It is approximately a linear relationship, so the model of the IP component can be simplified to the zero-order steady-state model of the IP component shown in formula (1), which is expressed as:

[0064] P b =0.15I-0.009 (1);

[0065] At the same time, the excitation current I and output pressure P are obtained by fitting.out It is also a linear relationship, so the back pressure chamber pressure P is obtained b and output pressure P out The relationship is linear, that is, the steady-state model of the pneumatic amplifier can also be simplified to a zero-order model. The IP component and the pneumatic amplifier are in series. The two zero-order models are connected in series and can be combined and simplified to I and P. out The linear relationship is shown in formula (2):

[0066] P out =1.7I-0.525 (2);

[0067] From equations (1) and (2), it is easy to obtain the back pressure chamber pressure P b and output pressure P out The relationship between , that is, the zero-order steady-state model of the pneumatic amplifier is obtained, as shown in formula (3):

[0068] P out =11.87P b -0.421 (3);

[0069] S12: Construct the motion model of pneumatic diaphragm actuator;

[0070] The valve stem movement of the pneumatic diaphragm actuator is mainly affected by the spring force F k , the downward pressure F0 generated by the atmospheric pressure P0 at the diaphragm, the output pressure P out The upward thrust F P The total weight F of the moving parts such as the valve stem and valve core g , friction force F f The equilibrium equation is:

[0071] F P =F0+F k +F f +F g (4)

[0072] The motion model of the pneumatic diaphragm actuator can be expressed as the second-order motion equation shown in formula (5):

[0073]

[0074] Among them, c is the velocity damping coefficient of the valve stem, in N*s / mm; n is the number of springs in the pneumatic diaphragm actuator; k is the elastic coefficient of the spring, in N / mm; L is the relative displacement of the valve stem, in mm; Ae is the effective area of ​​the diaphragm;

[0075] S13: constructing a valve position feedback mechanism model;

[0076] The output voltage value of the potentiometer of the valve position feedback mechanism ranges from 0 to 2.5V. The radius of the large gear is R, the radius of the small gear is r, and the conversion accuracy is n, that is, the potential value changes by 2.5 / nV for each rotation of the small gear. The relationship between the relative displacement L of the valve stem and the feedback voltage signal V of the valve stem can be expressed as:

[0077]

[0078] in, is a constant, so the valve position feedback mechanism model is a typical zero-order linear link;

[0079] S14: Based on the zero-order steady-state model of the IP component, the zero-order steady-state model of the pneumatic amplifier, the motion model of the pneumatic diaphragm actuator and the valve position feedback mechanism model, the intelligent valve positioner model is constructed; the intelligent valve positioner system model is in the form of a second-order transfer function, which can be expressed as:

[0080]

[0081] Among them, K, ζ, ω n is the set model parameter, and s represents the input of the Laplace transform in the transfer function.

[0082] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0083] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An intelligent valve positioner system based on active disturbance rejection control, characterized in that: Includes tracking differentiator, extended state observer, nonlinear feedback controller and intelligent valve positioner; The tracking differentiator sets a transition process v1 according to a set reference signal v0, extracts a differential signal v2 from the intelligent valve positioner, and sends the transition process v1 and the differential signal v2 to the nonlinear feedback controller; The extended state observer receives the actual control signal u and the feedback signal x, calculates the tracking signal z1 and the differential signal z2 of the feedback signal x, and calculates the disturbance sum z3 according to the actual control signal u and the feedback signal x in combination with the intelligent valve positioner model corresponding to the intelligent valve positioner; sends the tracking signal z1, the differential signal z2 and the disturbance sum z3 to the nonlinear feedback controller; The nonlinear feedback controller receives the transition process v1, the differential signal v2, the tracking signal z1 and the differential signal z2 to calculate the feedback control signal u0; compensates the disturbance sum z3 into the feedback control signal u0, and transmits it to the intelligent valve positioner; The intelligent valve positioner collects the actual control signal u and the feedback signal x and transmits them to the extended state observer, and receives the feedback control signal u0 and generates an anti-disturbance control signal in combination with the actual control signal u, and performs automatic control adjustment according to the anti-disturbance control signal.

2. The intelligent valve positioner system based on active disturbance rejection control according to claim 1, characterized in that: The intelligent valve positioner model calculates the error part and the position disturbance part according to the actual control signal u and the feedback signal x, respectively, and sums the error part and the position disturbance part to obtain the disturbance sum z3.

3. The intelligent valve positioner system based on active disturbance rejection control according to claim 1, characterized in that: The nonlinear feedback controller calculates the transition state error e1=v1-z1 according to the transition process v1 and the tracking signal z1; calculates the differential signal state error e2=v2-z2 according to the differential signal v2 and the differential signal z2; and calculates the feedback control signal u0 using the nonlinear combination of the transition state error and the differential signal state error.

4. The intelligent valve positioner system based on active disturbance rejection control according to claim 1, characterized in that: The intelligent valve positioner includes an IP component, a valve position feedback mechanism, a pneumatic amplifier, a pneumatic film actuator, a valve and a controller; wherein the controller receives actual control signals and feedback signals and performs control operations, generates control signals and converts them into current control signals for transmission to the IP component; the torque motor in the IP component generates an electromagnetic torque of corresponding magnitude to drive the nozzle baffle to move, and changes the size of the nozzle by controlling the distance between the baffle and the nozzle, thereby adjusting the back pressure chamber pressure of the pneumatic amplifier; the pneumatic amplifier compares the air pressure values ​​in each mold cavity, amplifies the small pressure signal into a large pressure signal, and uses the large pressure signal to drive the pneumatic film actuator to realize the conversion of air pressure into the displacement of the valve stem of the valve.

5. The intelligent valve positioner system based on active disturbance rejection control according to claim 4 is characterized in that: The actual control signal u is the excitation current I output to the IP component, and the feedback signal x is the valve stem feedback voltage signal V obtained by the valve position feedback mechanism.

6. The intelligent valve positioner system based on active disturbance rejection control according to claim 5, characterized in that: The excitation current is collected by a current collection and conditioning circuit, and the valve position feedback voltage collection circuit is used to collect the valve stem feedback voltage signal; the valve stem feedback voltage signal is normalized and then transmitted to the expanded state observer as a feedback signal x.

7. A control method for an intelligent valve positioner system based on active disturbance rejection control, characterized in that: An intelligent valve positioner system based on active disturbance rejection control as described in any one of claims 1 to 6 comprises the following steps: Step 1: Construct an intelligent valve positioner model under an ideal gas environment; Step 2: The tracking differentiator sets the transition process v1 according to the set reference signal v0, and extracts the differential signal v2 from the smart valve positioner; Step 3: Collect the actual control signal u input to the intelligent valve positioner and the feedback signal x of the intelligent valve positioner, calculate the tracking signal z1 and the differential signal z2 of the feedback signal x by the extended state observer, and calculate the disturbance sum z3 in combination with the intelligent valve positioner model; Step 4: The nonlinear feedback controller calculates the feedback control signal u0 according to the transition process v1, the differential signal v2, the tracking signal z1 and the differential signal z2, and compensates the disturbance sum z3 into the feedback control signal u0; Step 5: Adjust the intelligent valve positioner according to the feedback control signal u0.

8. The control method of an intelligent valve positioner system based on active disturbance rejection control according to claim 7 is characterized in that: The specific process of step 1 is: Step 11: Construct the zero-order steady-state model of the IP component and the zero-order steady-state model of the pneumatic amplifier; Input linearly increasing and decreasing driving current in the range of 0-1mA into the intelligent valve positioner, and record the excitation current I and back pressure chamber pressure P in steady state. b and output pressure P out , fitting the recorded data, and obtaining the excitation current I and the back pressure chamber pressure P b , excitation current I and output pressure P out are linearly related, so the back pressure chamber pressure P b and output pressure P out It is a linear relationship, and the zero-order steady-state model of the IP component is expressed as: P b =0.15I-0.009; The IP component and the pneumatic amplifier are in series relationship. The zero-order steady-state model of the IP component and the zero-order steady-state model of the pneumatic amplifier are combined in series to obtain the excitation current I and the output pressure P out The linear relationship is expressed as: P out =1.7I-0.525; According to the zero-order steady-state model of the IP component, the excitation current I and the output pressure P out The linear relationship between and is obtained, and the zero-order steady-state model of the pneumatic amplifier is obtained, which is expressed as: P out =11.87P b -0.421; Step 12: Construct the motion model of the pneumatic diaphragm actuator; The motion model of the pneumatic diaphragm actuator is expressed as a second-order motion equation: Wherein, c is the velocity damping coefficient of the valve stem; n is the number of springs in the pneumatic diaphragm actuator; k is the elastic coefficient of the spring; L is the relative displacement; Ae is the effective area of ​​the diaphragm; Step 13: Construct the valve position feedback mechanism model, expressed as: Wherein, V represents the valve stem feedback voltage signal; L represents the relative displacement; is a constant, R represents the radius of the large gear of the valve position feedback mechanism, r represents the radius of the small gear of the valve position feedback mechanism, and n represents the conversion accuracy; Step 14: Construct an intelligent valve positioner model based on the zero-order steady-state model of the IP component, the zero-order steady-state model of the pneumatic amplifier, the motion model of the pneumatic diaphragm actuator, and the valve position feedback mechanism model.

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