CN116382357A - Water adding flow control method based on equal-percentage flow characteristic model - Google Patents
Water adding flow control method based on equal-percentage flow characteristic model Download PDFInfo
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Abstract
The invention relates to a water adding flow control method based on an equal percentage flow characteristic model, belonging to the technical field of tobacco redrying and hot air moistening; the water adding flow control system based on the equal percentage flow characteristic model comprises the following steps: step one, data acquisition and arrangement of flow rate of each hot air leaf wetting machine and variable data of a film valve, step two, building a model according to different valve opening degrees of different flow characteristics, performing actual verification on a pneumatic film valve of a three-purpose production line one-time leaf wetting machine, step four, collecting signal addresses of all control points, and writing an AB system PLC program; according to the invention, a large amount of data is collected, software modeling is used, water is added to the feeding end and the discharging end of the primary and secondary hot air leaf wetting machine of the redrying workshop production line for compound control, the accuracy of water addition can be well controlled, the steaming rate is reduced, the water stain smoke is reduced, the failure stop rate is reduced, and the yield of finished products is improved.
Description
Technical Field
The invention relates to a water adding flow control method based on an equal percentage flow characteristic model, and belongs to the technical field of tobacco redrying and hot air moistening.
Background
In the threshing and redrying production line in the redrying room of the cigarette factory, the primary tobacco moistening and the secondary tobacco moistening processes all need to use a hot air tobacco moistening machine to heat and moisten tobacco leaves. In the hot air leaf wetting machine, a hot air system and in-cylinder direct-injection steam are used for heating tobacco leaves, a pneumatic film valve is used for respectively controlling water and steam to be mixed into the tobacco leaves through an in-cylinder nozzle for humidification, the leaf wetting quality directly influences the quality of follow-up leaf threshing procedures and the qualification rate of products, secondary leaf wetting is used as a key procedure for adjusting the temperature and the moisture of materials before leaf threshing, the completion condition of the procedure quality characteristics directly influences the leaf tearing effect of the leaf threshing wind separation procedure, and finally, important indexes such as the structure, the leaf yield and the like of finished product tobacco sheets are influenced. The switch of the two leaf wetting and redrying pretreatment processes has occasional network faults, unstable flow meters and disconnection, so that the flow meters of the leaf wetting machine are stopped, water addition is abnormal and the like, and the leaf wetting quality is affected.
Therefore, the water adding flow control method based on the equal percentage flow characteristic model is provided, and water is added to the feeding end and the discharging end of the hot air leaf wetting machine for compound control.
Disclosure of Invention
In order to overcome the problems in the background art, the invention uses software modeling to realize the composite control of the water adding at the feeding end and the discharging end of the primary and secondary hot air leaf wetting machine of the redrying workshop production line by the new control method, thereby being capable of very well controlling the accuracy of water adding, avoiding the occurrence of the conditions that the shutdown and the inaccurate water adding caused by the network faults and instability of the flowmeter affect the quality of tobacco leaves, reducing the steaming rate, the water-soaked tobacco and the like, reducing the failure stop rate, ensuring the normal operation of production and improving the internal quality and the qualification rate of the finished products of the tobacco leaves.
In order to solve the problems in the background art, the invention is realized by the following technical scheme:
a water adding flow control method based on an equal percentage flow characteristic model comprises the following steps:
step one, data acquisition and arrangement, acquisition: the primary leaf wetting machine and the secondary leaf wetting machine 30 of the production line produce data of flow rate and film valve variable of each hot air leaf wetting machine;
establishing a model, namely establishing models based on the equal-percentage flow characteristic models according to different valve openings of different flow characteristics;
step three, selecting an optimal model according to the optimal fitting degree and the mechanism model, and optimizing optimal parameters;
step four, programming an AB system PLC program, collecting signal addresses of all control points, drawing a calibration program flow chart, and adding an independent control program of a film valve;
preferably, in the first step, the maximum and minimum flow values are determined according to the maximum and minimum valve opening, and the abnormal values are removed, and the continuous data mutation data are removed.
Preferably, in the second step, the relationship between the valve opening and the flow and the pressure is not determined according to a calculation formula, specifically, the specific test curve is a typical nonlinear curve, linearization processing cannot be performed according to a specific test curve, the working characteristics of the regulating valve have the nonlinear characteristics of dead zone and hysteresis, the nonlinear component of the valve is smaller, the linear valve characteristics can be analyzed by using an approximate proportional link, in the analysis and correction calculation of the control loop, the valve serving as the regulating mechanism is represented by a proportional link, the regulating valve of the general linear flow characteristics has a linear relationship between the relative flow and the relative opening, namely, the relative flow change caused by the unit relative opening change is a constant, and the differential equation is as follows:
d Q /d L ＝k f (1)
the integral can be obtained:
Q＝k f L+C(2)
using the boundary conditions, C and k can be derived f Is the value of (1):
C＝Qmin/Qmax(3)
k f ＝1-Qmin/Qmax (4)
so that:
Q＝[1+(R-1)L]/R (5)
wherein k is f The ratio coefficient, C, R, Q, and L are respectively the adjustable range of the regulator valve, the relative flow rate, and the relative opening degree, and (5) the formula:
R＝Qmax/Qmin (6)
qmax represents the maximum flow rate, qmin represents the minimum flow rate;
the analysis method of the nonlinear system is a descriptive function method, G(s) corresponds to the linear flow characteristic of the valve, the dead zone and return error generate nonlinear links, and the transfer function of the linear part can be expressed as:
G(s) ＝K/[s(s+1)] (7)
wherein K represents a proportionality coefficient and S represents an error;
and obtaining a component block diagram of the control system and a linear link of the actual characteristic of the regulating valve according to the transfer function.
Preferably, the second step is to build a model, wherein the linear flow characteristic is that the opening of the valve is in direct proportion to the flow, the opening of the valve reaches 50%, and the flow of the valve also reaches 50%; the equal hundred flow characteristics are contrary to the quick opening type, the relation between the valve opening and the flow and the pressure are not determined, and the relation between the relative flow Q/Qmax and the relative opening L/Lmax of the specific test curve regulating valve to be obtained according to the claim 3 is as follows:
Q/Qmax＝f(L/Lmax)) (8)
the relative flow rate Q/Qmax of the regulating valve and the relative opening L/Lmax are related as follows:
Q/Qmax＝f(L/Lmax) (dP1/dP)^(1/2) (9)
wherein Q represents a relative flow rate, L represents a relative opening degree, and P represents a pressure; the inherent flow characteristics of the regulator valve itself depend on the spool shape, the simplest of which is the straight line flow characteristics: the relative flow of the regulating valve and the relative opening degree are in a linear relation, namely the flow change caused by single-stroke change is a constant;
the ratio of the maximum flow rate to the minimum flow rate which can be controlled by the valve is called an adjustable ratio, the adjustable ratio is expressed by R, and R=qmax/Qmin, and the relation between the flow rate and the opening of the linear flow rate characteristic is as follows:
Q/Qmax＝(1/R)[1+(R-1)L/Lmax] (10)
when the opening is half, Q/qmax=51.7%,
equal percentage flow characteristics:
Q/Qmax＝R^(L/Lmax-1) (11)
when the opening is half, Q/qmax=18.3%,
quick-opening flow characteristics:
Q/Qmax＝(1/R)[1+(R^2-1)L/Lmax]^(1/2) (12)
when the opening is half, Q/qmax=75.8%,
wherein Qmax represents the maximum flow rate, qmin represents the minimum flow rate, and Lmax represents the maximum opening;
preferably, the data of the database is collected, modeling is carried out based on an equal percentage flow characteristic model Q/Qmax=R (L/Lmax-1) by using a software tool, modeling is respectively attempted by using Gaussian, interpolant, polynomial, linear Fitting and smoothening spring, a model with the minimum index is searched according to the best Fitting degree and mechanism model and according to statistical indexes such as SSE (sum of variance), R-square (determining coefficient) and the like, and a Linear Fitting model is selected to optimize the best parameters.
Preferably, in the fourth step, the PLC program of the AB system is written, the signal addresses of all control points are collected, a calibration program flow chart is drawn, an independent control program of a film valve is added, the independent control program is downloaded to the PLC, a control program and an alarm program written into the AB software are debugged, network faults or abnormal flow occur, and the system is automatically switched to a water adding estimated value of a feeding end and a water adding estimated value of a discharging end calculated by a model for water adding.
The beneficial effects of the invention are as follows:
according to the invention, a large amount of data is collected, software modeling is applied, a new control method is used for carrying out compound control on the water feeding end and the water feeding end of the primary hot air leaf wetting machine and the secondary hot air leaf wetting machine of the production line of the redrying workshop, the accuracy of water feeding quantity can be well controlled, the situations that the shutdown and the inaccurate water feeding influence the quality of tobacco leaves and the like caused by network faults and instability of a flowmeter are avoided, the steaming rate, the water-soaked tobacco and the like are reduced, the failure stop rate is reduced, the normal operation of production is ensured, and the internal quality of tobacco leaves and the qualification rate of finished products are improved.
Drawings
FIG. 1 is a flow chart of the flow meter control of the present invention;
FIG. 2 is a block diagram of a control system of the present invention;
FIG. 3 is a real Gaussian model of the present invention;
FIG. 4 is an interpolart model of the present invention;
FIG. 5 is a linear mapping model of the present invention;
FIG. 6 is a polynominal model of the invention;
FIG. 7 is a smoothening spring model of the present invention;
FIG. 8 is experimental data for a single-pass leaf-wetting machine of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantageous effects of the present invention more apparent, preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, so as to facilitate understanding of the skilled person.
As shown in fig. 1 to 8, the specific implementation steps of the water adding flow control method based on the equal percentage flow characteristic model are as follows:
step one, data acquisition and arrangement, namely acquiring multiple data of the flow rate of each hot air leaf-wetting machine and the variable 80000 of a film valve every day, acquiring total 4 pieces of equipment of a primary leaf-wetting machine and a secondary leaf-wetting machine of two production lines A, B, acquiring 30 production days, acquiring 960 tens of thousands of pieces of data in total, acquiring 86031 pieces of data according to the data acquisition process shown in the following figure 1, determining the maximum value and the minimum value of the flow rate according to the maximum and minimum opening of the valve, removing abnormal values, and removing continuous data mutation data to obtain final available data.
Step two, a model is built, and different valve opening degrees are generated according to different flow characteristics: the quick-opening flow characteristic has large initial change and relatively gentle rear face; the linear flow characteristic is that the opening of the valve is in direct proportion to the flow, that is to say, the opening of the valve reaches 50%, and the flow of the valve also reaches 50%; the equal hundred flow characteristics, as opposed to the quick open type, are small in initial variation and larger in later. The relation between the valve opening and the flow and pressure has no definite calculation formula. Their relationship can only be expressed by a general functional formula, and a specific test flow characteristic curve is specifically examined.
The flow characteristic curve calculation process is that typical nonlinear links cannot be subjected to linearization processing, and the typical nonlinear links have adverse effects on the performance of a control system. The gap characteristic may cause instability of the system, the dead zone characteristic may cause steady state error of the system, and the like. In terms of the operating characteristics of the regulator valve, it has dead zone, hysteresis non-linear characteristics. In general, the nonlinear components of a valve are small, so that an approximate proportional element can be used to analyze the linear valve characteristics. In the evaluation and correction calculations of the control circuit, the valve as the regulating means is represented in a proportional element. However, if the dead zone and return errors of the valve are large, such approximation can produce large errors that severely degrade the regulation quality of the control system and must be carefully treated. Among the thin film regulating valves used, a regulating valve having a linear flow characteristic is generally used, in which the relative flow and the relative opening are in a linear relationship, that is, the relative flow change due to a change in the unit relative opening is a constant, and the differential equation is:
d Q /d L ＝k f (1)
integration can be obtained by q=k f L+C(2)
Using the boundary conditions, C and k can be derived f Is the value of (1):
C＝Qmin/Qmax(3)
k f ＝1-Qmin/Qmax(4)
so that Q= [1+ (R-1) L ]/R (5)
Wherein k is f The ratio coefficient, C, R, Q, and L are respectively the adjustable range of the regulator valve, the relative flow rate, and the relative opening degree, and (5) the formula:
R＝Qmax/Qmin(6)
if the adjustable minimum flow of the regulating valve is 2% -4% of the maximum flow, the value of R is 25-50, and when R=40, the flow characteristic equation is as follows:
Q＝0.024+0.975L
on the one hand, the pressure difference between the front and rear of the valve changes due to the change of the flow area, and on the other hand, the working flow characteristics of the valve are distorted due to the return error and the slow response of the valve, and nonlinear components are contained in the flow characteristics. Thus, the actual characteristic of the regulator valve should be a combination of a linear element and 1 non-linear element. The control system is shown in the block diagram of fig. 2.
The flow characteristics are distorted from solid line portions to broken line portions due to dead zone and return errors, and hysteresis characteristics exist.
The analysis method of the nonlinear system comprises a descriptive function method and a phase plane. The descriptive function is an extension of the frequency analysis method on a nonlinear system, and can determine the stability of the control system and whether a limit cycle exists, but cannot provide an exact time response characteristic. It is also helpful to describe the functional approach for determining the stability of the system. G(s) corresponds to the linear flow characteristic of the valve, and N (E) is a nonlinear link generated by dead zone and return error. The transfer function of the linear portion can be expressed as:
G(s)＝K/[s(s+1)] (7)
wherein K represents a proportionality coefficient and S represents an error;
the nonlinear section N (E) can be represented by a gap characteristic whose sinusoidal input, X (t) =output y (t) of E sin ωt, is:
wherein k represents a slope; e represents the input amplitude; delta represents a dead zone; ω represents angular frequency.
From the y (t) equation, we can solve the description function N (E) of the hysteresis gap characteristic by Fourier transform expansion, and analyze the influence of N (E) on the stability of the closed loop system by the relative position between 2 root tracks of-l/N (E) and G (j omega) by root track analysis. If the trajectory of-l/N (E) is not surrounded by the trajectory of G (jω), the system is stable; if the trajectory of-l/N (E) is surrounded by the trajectory of G (jω), the system is unstable; if there is a trace intersection, the system may produce a sustained oscillation. The open-loop frequency characteristic curve of the flow characteristic of the valve in the S plane is 1 parabola with r=k as asymptote in the 3 rd quadrant, which does not contain (-l, j 0) point, and the system is stable. In the presence of hysteresis gap characteristics, when the slopes k and E/delta are not appropriate, the intersection of the-l/N (E) curve and the G (jω) curve may occur, causing the system to oscillate. Thus, the presence of nonlinear components may deteriorate the stability of the control system.
Relationship between the relative flow Q/Qmax and the relative opening L/Lmax of the regulating valve obtained according to the flow special effect curve of the regulating valve:
Q/Qmax＝f(L/Lmax) (8)
relation between the relative flow rate Q/Qmax of the regulating valve and the relative opening L/Lmax, the differential pressure across the valve:
Q/Qmax＝f(L/Lmax)(dP1/dP)^(1/2) (9)
wherein Q represents a relative flow rate, L represents a relative opening degree, and P represents a pressure;
the inherent flow characteristics of the regulator valve itself depend on the spool shape, the simplest of which is the straight line flow characteristics: the relative flow rate of the regulating valve is in a linear relation with the relative opening, i.e. the flow rate change caused by the single stroke change is a constant.
The ratio of the maximum flow rate to the minimum flow rate which can be controlled by the valve is called an adjustable ratio, and is expressed by R, wherein R=qmax/Qmin, the relation between the flow rate and the opening of the linear flow rate characteristic is as follows:
Q/Qmax＝(1/R)[1+(R-1)L/Lmax] (10)
when the opening is half, Q/qmax=51.7%
Equal percentage flow characteristics:
Q/Qmax＝R^(L/Lmax-1) (11)
when the opening is half, Q/qmax=18.3%.
Quick-opening flow characteristics:
Q/Qmax＝(1/R)[1+(R^2-1)L/Lmax]^(1/2) (12)
when the opening is half, Q/qmax=75.8%.
Wherein Q represents the flow rate, qmax represents the maximum flow rate, qmin represents the minimum flow rate, and Lmax represents the maximum opening;
step three, 960 tens of thousands of data of the database are collected, and the data are processed by the following steps ofFor a pair ofAfter deleting irrelevant variable data and removing abnormal data, modeling is performed by using Curve Fitting tool tools of MATLAB software based on an equal-percentage flow characteristic model Q/Qmax=R (L/Lmax-1). The modeling process is shown in fig. 3 to 7 below, and modeling with Gaussian, interpolant, polynomial, linear fixing, and Smoothing spring, respectively, is attempted. Experiment verifies that according to the best Fitting degree and mechanism model, namely the model with the minimum index is searched according to SSE (sum of variance), R-square (determination coefficient) and other statistical indexes, a Linear Fitting model is selected, the best parameters are optimized, the actual verification is carried out on the feed end estimated value and the discharge end estimated value of different valve set opening degrees under the water pressure of 0.45MPa, and the actual value of a specific feed end, the actual value of the discharge end and the deviation between the estimated values are obtained, and finally the method is shown in the following figure 7.
Step four, programming an AB system PLC program, collecting signal addresses of all control points, drawing a calibration program flow chart, adding an independent control program of a film valve, downloading the independent control program into the PLC, debugging a control and alarm program written into the AB software, and automatically switching the system to an estimated value calculated by a model for adding water if network failure or abnormal flow occurs;
program path: yffk 2015_131_a. Acd- > cntr_analog, feed side water addition estimate 30 ((f131.hmi_cylider_status. Y24_pv-10.0)/90.0-1) 430 variable FK131_out_water_y24_1
The water addition estimate at the discharge end is 20 ((FK 131.HMI_CYLINDER_STATUS. Y25_PV-25.0)/75.0-1) 430 variable FK131_out_water_Y25_1.
Finally, the actual application effect monitoring is carried out, the result is connected to an upper computer HMI system and is applied to tobacco leaves with different grades, the estimated value of the water adding value of the first moistening feeding end, the second moistening feeding end and the water adding value of the discharging end are respectively compared with the flow value of a flowmeter which normally operates, operation monitoring data acquire one data every second, specifically, the curve change of the actual value and the estimated value of the adding water of the VCO3S at the feeding end of the A-line primary wetting machine, the curve change of the VBO1S adding water at the feeding end of the A-line primary wetting machine, the curve change of the C2FS adding water at the feeding end of the A-line secondary wetting machine, the curve change of the comparison curve of the actual value and the estimated value of the VCO1S adding water at the feeding end of the A-line secondary wetting machine, the curve change of the VCO1S grade tobacco adding water at the feeding end of the B-line primary wetting machine, the curve change of the VCO3S tobacco adding water at the feeding end of the B-line primary wetting machine and the estimated value, the curve change of the C2F tobacco adding water at the feeding end of the B-line secondary wetting machine and the curve change of the VBO1S adding water at the feeding end of the B-line secondary wetting machine and the curve change of the estimated value and the state of the flow meter adding water of the pre-processing Duan Runshe machine are monitored, so that the fitting degree is improved and the error is reduced.
According to the invention, a large amount of data is collected, MATLAB software is used for modeling, a new control method is used for carrying out compound control on the water feeding end and the water feeding end of the primary and secondary hot air leaf wetting machine of the production line between redrying vehicles, the accuracy of water feeding can be well controlled, the situations that the shutdown and the inaccurate water feeding influence the quality of tobacco leaves caused by the network faults and instability of the flowmeter are avoided, the steaming rate, the water smoke stain rate and the like are reduced, the failure shutdown rate is reduced, the normal operation of production is ensured, and the internal quality of tobacco leaves and the yield of finished products are improved.
Finally, it is noted that the above-mentioned preferred embodiments are only intended to illustrate rather than limit the invention, and that, although the invention has been described in detail by means of the above-mentioned preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention as defined by the appended claims.
Claims (6)
1. A water adding flow control method based on an equal percentage flow characteristic model is characterized by comprising the following steps of: the water adding flow control method based on the equal percentage flow characteristic model comprises the following steps of:
step one, data acquisition and arrangement, acquisition: the primary leaf wetting machine and the secondary leaf wetting machine 30 of the production line produce data of flow rate and film valve variable of each hot air leaf wetting machine;
establishing a model, namely establishing models based on the equal-percentage flow characteristic models according to different valve openings of different flow characteristics;
step three, selecting an optimal model according to the optimal fitting degree and the mechanism model, and optimizing optimal parameters;
and step four, programming an AB system PLC program, collecting signal addresses of all control points, drawing a calibration program flow chart, and adding an independent control program of the film valve.
2. The water addition flow control method based on the equal percentage flow characteristic model according to claim 1, wherein the method comprises the following steps: and step one, determining a maximum flow value and a minimum flow value according to the maximum and minimum valve opening, removing abnormal values, and removing continuous data mutation data.
3. The water addition flow control method based on the equal percentage flow characteristic model according to claim 1, wherein the method comprises the following steps: the second step, the equal hundred flow characteristic, contrary to the quick-open type, the relation between the valve opening and the flow and the pressure are not determined, the specific test curve is a typical nonlinear curve, linearization treatment cannot be performed, the working characteristic of the regulating valve is provided with the nonlinear characteristic of dead zone and hysteresis, the nonlinear component of the valve is smaller, the linear valve characteristic can be analyzed by using an approximate proportion link, in the analysis and correction calculation of the control loop, the valve serving as the regulating mechanism is expressed by a proportion link, the regulating valve with the general linear flow characteristic has a linear relation between the relative flow and the relative opening, namely, the relative flow change caused by the unit relative opening change is a constant, and the differential equation is as follows:
d Q /d L ＝k f (1)
the integral can be obtained:
Q＝k f L+C (2)
using the boundary conditions, C and k can be derived f Is the value of (1):
C＝Qmin/Qmax (3)
k f ＝1-Qmin/Qmax (4)
so that:
Q＝[1+(R-1)L]/R (5)
wherein k is f The ratio coefficient, C, R, Q, and L are respectively the adjustable range of the regulator valve, the relative flow rate, and the relative opening degree, and (5) the formula:
R＝Qmax/Qmin (6)
qmax represents the maximum flow rate, qmin represents the minimum flow rate;
the analysis method of the nonlinear system is a descriptive function method, G(s) corresponds to the linear flow characteristic of the valve, the dead zone and return error generate nonlinear links, and the transfer function of the linear part can be expressed as:
G(s) ＝K/[s(s+1)] (7)
wherein K represents a proportionality coefficient and S represents an error;
and obtaining a component block diagram of the control system and a linear link of the actual characteristic of the regulating valve according to the transfer function.
4. The water addition flow control method based on the equal percentage flow characteristic model according to claim 1, wherein the method comprises the following steps: establishing a model, wherein the linear flow characteristic is that the opening of the valve is in direct proportion to the flow, the opening of the valve reaches 50%, and the flow of the valve also reaches 50%; equal hundred flow characteristics, contrary to quick opening, the relation between valve opening and flow, pressure, no definite calculation formula, the specific test curve to be obtained according to claim 3
The relative flow rate Q/Qmax and the relative opening L/Lmax of the regulating valve are expressed as follows:
Q/Qmax＝f(L/Lmax)) (8)
the relative flow rate Q/Qmax of the regulating valve and the relative opening L/Lmax are related as follows:
Q/Qmax＝f(L/Lmax)(dP1/dP)^(1/2) (9)
wherein Q represents a relative flow rate, L represents a relative opening degree, and P represents a pressure; the inherent flow characteristics of the regulator valve itself depend on the spool shape, the simplest of which is the straight line flow characteristics: the relative flow of the regulating valve and the relative opening degree are in a linear relation, namely the flow change caused by single-stroke change is a constant;
the ratio of the maximum flow rate to the minimum flow rate which can be controlled by the valve is called an adjustable ratio, the adjustable ratio is expressed by R, and R=qmax/Qmin, and the relation between the flow rate and the opening of the linear flow rate characteristic is as follows:
Q/Qmax＝(1/R)[1+(R-1)L/Lmax] (10)
equal percentage flow characteristics:
Q/Qmax＝R^(L/Lmax-1) (11)
quick-opening flow characteristics:
Q/Qmax＝(1/R)[1+(R^2-1)L/Lmax]^(1/2) (12)
where Qmax represents the maximum flow rate, qmin represents the minimum flow rate, and Lmax represents the maximum opening.
5. The water addition flow control method based on the equal percentage flow characteristic model according to claim 1, wherein the method comprises the following steps: the data of the database is collected, modeling is carried out based on an equal percentage flow characteristic model Q/Qmax=R (L/Lmax-1) by using a software tool, modeling is respectively attempted by using Gaussian, interpolant, polynomial, linear Fitting and smoothening slines, a model with the minimum index is searched according to the best Fitting degree and mechanism model and according to statistical indexes such as SSE (sum of variance), R-square (determining coefficient) and the like, and a Linear Fitting model is selected to optimize the best parameters.
6. The water addition flow control method based on the equal percentage flow characteristic model according to claim 1, wherein the method comprises the following steps: and step four, programming the PLC program of the AB system, collecting the signal addresses of all control points, drawing a calibration program flow chart, adding an independent control program of a film valve, downloading the independent control program into the PLC, debugging a control program and an alarm program written into the AB software, generating network faults or abnormal flow, and automatically switching the system to a feed end water adding estimated value and a discharge end water adding estimated value calculated by a model to add water.
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| CN117270586B (en) * | 2023-11-21 | 2024-01-30 | 深圳市普朗医疗科技发展有限公司 | Automatic quantitative control method and system for sodium hyaluronate gel preparation |
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