CN116671654A - Method for obtaining material moisture control model of silk-making leaf-wetting machine through test - Google Patents
Method for obtaining material moisture control model of silk-making leaf-wetting machine through test Download PDFInfo
- Publication number
- CN116671654A CN116671654A CN202310571476.XA CN202310571476A CN116671654A CN 116671654 A CN116671654 A CN 116671654A CN 202310571476 A CN202310571476 A CN 202310571476A CN 116671654 A CN116671654 A CN 116671654A
- Authority
- CN
- China
- Prior art keywords
- control
- leaf
- moisture
- value
- wetting machine
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000009736 wetting Methods 0.000 title claims abstract description 247
- 239000000463 material Substances 0.000 title claims abstract description 114
- 238000000034 method Methods 0.000 title claims abstract description 112
- 238000012360 testing method Methods 0.000 title claims abstract description 18
- 238000004519 manufacturing process Methods 0.000 claims abstract description 33
- 241000208125 Nicotiana Species 0.000 claims abstract description 29
- 235000002637 Nicotiana tabacum Nutrition 0.000 claims abstract description 29
- 230000008569 process Effects 0.000 claims abstract description 26
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 171
- 230000006641 stabilisation Effects 0.000 claims description 137
- 238000011105 stabilization Methods 0.000 claims description 137
- 230000001502 supplementing effect Effects 0.000 claims description 70
- 238000002347 injection Methods 0.000 claims description 46
- 239000007924 injection Substances 0.000 claims description 46
- 238000004364 calculation method Methods 0.000 claims description 34
- 238000012546 transfer Methods 0.000 claims description 10
- 238000005507 spraying Methods 0.000 claims description 6
- 230000003321 amplification Effects 0.000 claims description 4
- 238000004422 calculation algorithm Methods 0.000 claims description 4
- 238000007599 discharging Methods 0.000 claims description 4
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 4
- 230000003068 static effect Effects 0.000 claims description 4
- 230000009466 transformation Effects 0.000 claims description 4
- 230000008859 change Effects 0.000 claims description 3
- 230000000087 stabilizing effect Effects 0.000 claims description 3
- 238000010793 Steam injection (oil industry) Methods 0.000 claims description 2
- 238000013178 mathematical model Methods 0.000 abstract description 19
- 238000011217 control strategy Methods 0.000 abstract description 5
- 230000004044 response Effects 0.000 abstract description 5
- 238000012937 correction Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 238000012545 processing Methods 0.000 description 4
- 238000013528 artificial neural network Methods 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- 230000009471 action Effects 0.000 description 2
- 238000013459 approach Methods 0.000 description 2
- 235000019504 cigarettes Nutrition 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000001824 photoionisation detection Methods 0.000 description 2
- 238000004886 process control Methods 0.000 description 2
- 239000002699 waste material Substances 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 238000012795 verification Methods 0.000 description 1
Classifications
-
- A—HUMAN NECESSITIES
- A24—TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
- A24B—MANUFACTURE OR PREPARATION OF TOBACCO FOR SMOKING OR CHEWING; TOBACCO; SNUFF
- A24B9/00—Control of the moisture content of tobacco products, e.g. cigars, cigarettes, pipe tobacco
-
- A—HUMAN NECESSITIES
- A24—TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
- A24B—MANUFACTURE OR PREPARATION OF TOBACCO FOR SMOKING OR CHEWING; TOBACCO; SNUFF
- A24B3/00—Preparing tobacco in the factory
- A24B3/04—Humidifying or drying tobacco bunches or cut tobacco
-
- A—HUMAN NECESSITIES
- A24—TOBACCO; CIGARS; CIGARETTES; SIMULATED SMOKING DEVICES; SMOKERS' REQUISITES
- A24B—MANUFACTURE OR PREPARATION OF TOBACCO FOR SMOKING OR CHEWING; TOBACCO; SNUFF
- A24B3/00—Preparing tobacco in the factory
- A24B3/18—Other treatment of leaves, e.g. puffing, crimpling, cleaning
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P90/00—Enabling technologies with a potential contribution to greenhouse gas [GHG] emissions mitigation
- Y02P90/02—Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]
Landscapes
- Paper (AREA)
Abstract
The invention discloses a method for obtaining a material moisture control model of a tobacco shred making and leaf wetting machine through a test, which belongs to the technical field of tobacco shred making, and comprises the steps of entering a production stage when the leaf wetting machine meets production conditions; the method comprises the steps of controlling moisture of a leaf wetting machine in a production stage, and defining a stable stage of moisture control of the leaf wetting machine in a formulated form; when the moisture control of the tobacco leaf wetting machine enters a stable stage, a nonlinear time-varying system is approximated to a linear steady system, and a material moisture control model of the tobacco leaf wetting machine is obtained. The invention solves the problems of complex moisture control in the process of moistening leaves in the prior art, lack of an accurate mathematical model based on a control strategy adopted for improving the control model, and can approximate the properties and parameters of the accurate mathematical model at a stable stage in the production process, thereby obtaining the stability, stability margin, accuracy and time domain quick response characteristics of the material moisture control model of the silk-making leaf-moistening machine so as to further improve and correct the accurate mathematical model.
Description
Technical Field
The invention relates to the technical field of cigarette cut tobacco making, in particular to a method for obtaining a cut tobacco making and leaf wetting machine material moisture control model through a test.
Background
Moistening She Guocheng is an important procedure in the tobacco shred making process, and the tobacco flakes are heated and humidified to be completely loosened and reach a certain temperature and humidity so as to meet the process requirements of subsequent processing, and meanwhile, the toughness and the processing resistance of the tobacco flakes are improved. The purpose of controlling the moisture content of tobacco leaves is achieved by adjusting the frequency of the water adding pump.
The moisture control of the leaf wetting process is very complex due to the strong nonlinearity, uncertainty and large hysteresis of the leaf wetting and humidifying process and the special property of the tobacco leaf. In essence, the material moisture control of the silk-making leaf-wetting machine belongs to a nonlinear time-varying system, and can be approximately considered as a linear steady system at a relatively stable stage of certain production processes. And the control strategies of time lag Smith control, fuzzy control, neural network, self-adaptive control, predictive control and the like adopted for improving the control model often need an accurate mathematical model.
Disclosure of Invention
The invention aims to overcome the defects in the prior art, and provides a method for obtaining a material moisture control model of a silk-making leaf-wetting machine through a test, which solves the problems that in the prior art, moisture control is complex in a leaf-wetting process, an accurate mathematical model is lacking in a control strategy adopted based on the purpose of improving the control model, and the properties and parameters of the accurate mathematical model can be approximated in a stable production process, so that the stability, stability margin, accuracy and time domain quick response characteristics of the material moisture control model of the silk-making leaf-wetting machine are obtained, and the accurate mathematical model is further improved and corrected.
In order to achieve the above purpose, the invention is realized by adopting the following technical scheme:
the invention provides a method for obtaining a material moisture control model of a silk-making leaf-wetting machine through a test, which comprises the following steps:
entering a production stage when the leaf wetting machine meets production conditions;
the method comprises the steps of controlling moisture of a leaf wetting machine in a production stage, and defining a stable stage of moisture control of the leaf wetting machine in a formulated form;
when the moisture control of the tobacco leaf wetting machine enters a stable stage, a nonlinear time-varying system is approximated to a linear steady system, and a material moisture control model of the tobacco leaf wetting machine is obtained.
Further, the moisture control of the leaf wetting machine in the production stage comprises:
controlling inlet water adding control, outlet water supplementing water adding control, hot air control, moisture discharging negative pressure control and direct injection steam control in a moisture control loop of the leaf wetting machine by adopting a PID control module;
the set point SP in the PID control module is defined as a preset set point of the moisture control loop in the production phase, said preset set point comprising equipment parameters and/or recipe parameters.
Further, the method for controlling the moisture of the leaf wetting machine in the production stage further comprises the following steps:
when the infrared moisture meter at the outlet detects that the outlet has the material moisture value, controlling the water supplementing and adding of the outlet as a main material moisture control loop; the outlet water supplementing and adding control is used for controlling the water content of the outlet materials;
And canceling a preset set value of the outlet water supplementing and adding control loop, feeding back the water content value of the outlet material to a set value SP of the outlet water supplementing and adding PID control loop in a PID cascade mode, and performing closed-loop control.
Further, the defining of the stable phase of the moisture control of the leaf wetting machine comprises the following steps:
inlet water adding control 1 in corresponding outlet material water control loop of leaf wetting machine # PID loop and outlet water supplementing and adding control 2 # The PID loop enters a moisture control stable state;
wherein the duration is time 1 Inlet water addition control 1 during the time of (2) # Set point SP of PID loop 1 Subtracting the actual value PV 1 The absolute value of the difference of the means of (a) is below the threshold value TV 1 And the duration is the actual value PV within time1 1 Standard deviation SD of 1 Below threshold value TV 2 ；
Duration is time 2 Outlet water make-up and water addition control 2 in the time of (2) # Set point SP of PID loop 2 Subtracting the actual value PV 2 The absolute value of the difference of the means of (a) is below the threshold value TV 3 And the duration is time 2 Actual value PV over time of (a) 2 Standard deviation SD of 2 Below threshold value TV 4 。
Further, the defining formula of the stable phase of the moisture control of the leaf wetting machine comprises the following steps:
control 1 for inlet Water addition # PID loop with duration time 1 Is within the time of (1):
in the method, in the process of the invention,actual value of inlet water addition PV for moisture control stabilization stage of leaf-wetting machine 1 Mean, SP of (V) 1 Set value of water adding amount for inlet of moisture control stable stage of leaf wetting machine, TV 1 Inlet water-adding control 1 for moisture control stabilization stage of leaf-wetting machine # A threshold value of the PID loop;
the calculation formula of (2) is as follows:
wherein n is 1 Actual value of inlet water addition PV for moisture control stabilization stage of leaf-wetting machine 1 Is set in the number of (3),actual value of inlet water addition PV for moisture control stabilization stage of leaf-wetting machine 1 Is the sum of (3);
SD 1 the calculation formula of (2) is as follows:
in SD (secure digital) 1 Actual value of inlet water addition PV for moisture control stabilization stage of leaf-wetting machine 1 Standard deviation of X i Actual value of inlet water addition PV for moisture control stabilization stage of leaf-wetting machine 1 Is a single sample value of (1);
duration is time 1 SD in (a) time period 1 ＜TV 2 ；TV 2 Inlet water-adding control 1 for moisture control stabilization stage of leaf-wetting machine # A threshold value of the PID loop;
water replenishing and adding control 2 for outlet # PID loop with duration time 2 Is within the time of (1):
in the method, in the process of the invention,actual value PV of outlet make-up water for moisture control stabilization stage of leaf-wetting machine 2 Mean, SP of (V) 2 Set value of outlet water supplementing quantity for moisture control and stabilization stage of leaf wetting machine, TV 3 Water supplementing and adding control 2 for outlet water supplementing and adding control 2 for moisture control stabilization stage of leaf wetting machine # A threshold value of the PID loop;
the calculation formula of (2) is as follows:
wherein n is 2 Actual value P of outlet make-up water quantity for moisture control stabilization stage of leaf-wetting machineV 2 Is set in the number of (3),actual value PV of outlet make-up water for moisture control stabilization stage of leaf-wetting machine 2 Is the sum of (3);
SD 2 the calculation formula of (2) is as follows:
in SD (secure digital) 2 Actual value PV of outlet make-up water for moisture control stabilization stage of leaf-wetting machine 2 Standard deviation of Y i Actual value PV of outlet make-up water for moisture control stabilization stage of leaf-wetting machine 2 Is a single sample value of (1);
duration is time 2 SD in (a) time period 2 ＜TV 4 ；TV 4 Water supplementing and adding control 2 for outlet water supplementing and adding control 2 for moisture control stabilization stage of leaf wetting machine # Threshold of PID loop.
Further, the definition of the stable phase of the moisture control of the leaf wetting machine further comprises:
the inlet water adding control is kept relatively stable and the outlet water supplementing water adding control is kept relatively stable; the hot air control, the moisture removal negative pressure control and the direct steam injection control are kept relatively stable;
the inlet water adding control is relatively stable and comprises an inlet water adding control 1 # Output value CV of PID loop 1 Remain below threshold TV 5 The outlet water supplementing and adding control is relatively stable and comprises an outlet water supplementing and adding control 2 # Output value CV of PID loop 2 Remain below threshold TV 6 ；
The hot air temperature control loop 3 is used for keeping the hot air control, the moisture removal negative pressure control and the direct injection steam control relatively stable # PID loop, moisture removal negative pressure 4 # PID loop and direct injection steam 5 # The PID loop enters a moisture stable state;
wherein the duration is time 4 Hot air temperature control 3 during the time of (2) # PID loopSet value SP of (1) 3 Subtracting the actual value PV 3 The absolute value of the difference of the means of (a) is below the threshold value TV 7 The method comprises the steps of carrying out a first treatment on the surface of the Duration is time 4 Actual value PV over time of (a) 3 Standard deviation SD of 3 Below threshold value TV 8 The method comprises the steps of carrying out a first treatment on the surface of the Duration is time 5 Moisture removal negative pressure 4 during the time period of (2) # Set point SP of PID loop 4 Subtracting the actual value PV 4 The absolute value of the difference of the means of (a) is below the threshold value TV 9 The method comprises the steps of carrying out a first treatment on the surface of the Duration is time 5 Actual value PV over time of (a) 4 Standard deviation SD of 4 Below threshold value TV 10 The method comprises the steps of carrying out a first treatment on the surface of the Duration is time 6 Is directly sprayed with steam 5 during the period of time # Set point SP of PID loop 5 Subtracting the actual value PV 5 The absolute value of the difference of the means of (a) is below the threshold value TV 11 The method comprises the steps of carrying out a first treatment on the surface of the Duration is time 6 Actual value PV over time of (a) 5 Standard deviation SD of 5 Below threshold value TV 12 。
Further, the defining formula of the stable phase of the moisture control of the leaf wetting machine further comprises:
CV 1 ＜TV 5 and the duration exceeds time 3 ；
CV 2 ＜TV 6 And the duration exceeds time 3 ；
In CV 1 Inlet water-adding control 1 for moisture control stabilization stage of leaf-wetting machine # Output value, CV, of PID loop 2 Water supplementing and adding control 2 for outlet water supplementing and adding control 2 for moisture control stabilization stage of leaf wetting machine # Output value of PID loop, TV 5 Inlet water-adding control 1 for moisture control stabilization stage of leaf-wetting machine # Threshold of PID loop, TV 6 Water supplementing and adding control 2 for outlet water supplementing and adding control 2 for moisture control stabilization stage of leaf wetting machine # A threshold value of the PID loop;
temperature control for hot air 3 # PID loop with duration time 4 Is within the time of (1):
in the method, in the process of the invention,actual value PV of hot air temperature for moisture control stabilization stage of leaf-wetting machine 3 Mean, SP of (V) 3 Set value of hot air temperature in stable stage of moisture control of leaf wetting machine, TV 7 Hot air temperature control 3 for moisture control stabilization stage of leaf wetting machine # A threshold value of the PID loop;
the calculation formula of (2) is as follows:
wherein n is 3 Actual value PV of hot air temperature for moisture control stabilization stage of leaf-wetting machine 3 Is set in the number of (3),actual value PV of hot air temperature for moisture control stabilization stage of leaf-wetting machine 3 Is the sum of (3);
SD 3 the calculation formula of (2) is as follows:
in SD (secure digital) 3 Actual value PV of hot air temperature for moisture control stabilization stage of leaf-wetting machine 3 Standard deviation of W i Actual value PV of hot air temperature for moisture control stabilization stage of leaf-wetting machine 3 Is a single sample value of (1);
duration is time 4 SD in (a) time period 3 ＜TV 8 ；TV 8 Hot air temperature control 3 for moisture control stabilization stage of leaf wetting machine # A threshold value of the PID loop;
for moisture removal negative pressure 4 # PID loop with duration time 5 Is within the time of (1):
in the method, in the process of the invention,actual value PV of moisture removal negative pressure for moisture control stabilization stage of leaf wetting machine 4 Mean, SP of (V) 4 Set value of moisture removal negative pressure in stable stage of moisture control of leaf wetting machine, TV 9 Moisture removal negative pressure 4 for moisture control and stabilization stage of leaf wetting machine # A threshold value of the PID loop;
the calculation formula of (2) is as follows:
wherein n is 4 Actual value PV of moisture removal negative pressure for moisture control stabilization stage of leaf wetting machine 4 Is set in the number of (3),actual value PV of moisture removal negative pressure for moisture control stabilization stage of leaf wetting machine 4 Is the sum of (3);
SD 4 the calculation formula of (2) is as follows:
in SD (secure digital) 4 Actual value PV of moisture removal negative pressure for moisture control stabilization stage of leaf wetting machine 4 Standard deviation of Z i Actual value PV of moisture removal negative pressure for moisture control stabilization stage of leaf wetting machine 4 Is a single sample value of (1);
duration is time 5 SD in (a) time period 4 ＜TV 10 ；TV 10 Moisture removal negative pressure 4 for moisture control and stabilization stage of leaf wetting machine # A threshold value of the PID loop;
for direct injection of steam 5 # PID loop, duration is time6 time:
In the method, in the process of the invention,actual value PV of direct-injection steam for moisture control stabilization stage of leaf-wetting machine 5 Mean, SP of (V) 5 Set value of direct-injection steam for moisture control stabilization stage of leaf wetting machine, TV 11 Direct injection steam 5 for moisture control stabilization stage of leaf-wetting machine # A threshold value of the PID loop;
the calculation formula of (2) is as follows:
wherein n is 5 Actual value PV of direct-injection steam for moisture control stabilization stage of leaf-wetting machine 5 Is set in the number of (3),actual value PV of direct-injection steam for moisture control stabilization stage of leaf-wetting machine 5 Is the sum of (3);
SD 5 the calculation formula of (2) is as follows:
in SD (secure digital) 5 Actual value PV of direct-injection steam for moisture control stabilization stage of leaf-wetting machine 5 Standard deviation of G i Is for moistening She JishuiActual value PV of direct injection steam for sub-control stabilization phase 5 Is a single sample value of (1);
duration is time 6 SD in (a) time period 5 ＜TV 12 ，TV 12 Direct injection steam 5 for moisture control stabilization stage of leaf-wetting machine # A threshold value of the PID loop;
further, the definition of the stable phase of the moisture control of the leaf wetting machine further comprises:
the control of the hot air temperature control loop, the opening of the moisture removal negative pressure valve and the control of the direct injection steam control loop are kept relatively stable; keeping the moisture of the material at the outlet of the leaf wetting machine in a stable and controlled state;
the control of the hot air temperature control loop is relatively stable and comprises hot air temperature control 3 # Output value CV of PID loop 3 Remain below threshold TV 13 And last for time 7 A length of time;
the opening of the moisture-removing negative pressure valve is relatively stable and comprises moisture-removing negative pressure 4 # Output value CV of PID loop 4 Remain below threshold TV 14 And last for time 8 A length of time;
the control of the direct injection steam control loop comprises the control of the direct injection steam 5 # Output value CV of PID loop 5 Remain below threshold TV 15 And last for time 9 A length of time;
the moisture of the outlet material of the leaf wetting machine is in a stable and controlled state and comprises the actual value Vtemp of the temperature of the outlet material real And the controlled demand value Vtemp set The absolute value of the difference of (c) remains below the threshold value TV 16 The method comprises the steps of carrying out a first treatment on the surface of the Actual value Vmos of outlet material moisture real And the controlled demand value Vmos set The absolute value of the difference of (c) remains below the threshold value TV 17 。
Further, the defining formula of the stable phase of the moisture control of the leaf wetting machine further comprises:
CV 3 ＜TV 13 and the duration exceeds time 7 ；
CV 4 ＜TV 14 And the duration exceeds time 8 ；
CV 5 ＜TV 15 And the duration exceeds time 9 ；
|Vtemp real -Vtemp set |＜TV 16 And the duration exceeds time 10 ；
|Vmos real -Vmos set |＜TV 17 And the duration exceeds time 11 ；
In CV 3 For controlling the temperature of hot air 3 # Output value, CV, of PID loop 4 For removing damp and negative pressure 4 # Output value, CV, of PID loop 5 For directly spraying steam 5 # Output value of PID loop, TV 13 For controlling the temperature of hot air 3 # Threshold of PID loop, TV 14 For removing damp and negative pressure 4 # Threshold of PID loop, TV 15 For directly spraying steam 5 # Threshold of PID loop, TV 16 And TV 17 For the corresponding outlet moisture related value, vtemp real As actual value of outlet material temperature, vtemp set Is the controlled requirement value of the outlet material temperature, vmos real For the actual value of the outlet material moisture, vmos set Is the controlled requirement value of the moisture of the outlet material.
Further, the method for obtaining the material moisture control model of the silk-making leaf-wetting machine comprises the following steps:
setting a fixed increment value for the frequency value of the outlet water supplementing and adding control output water supplementing pump, and simulating the fixed increment value into a stable step signal;
recording the data of the actual value of the water content of the outlet material along with the change of time t, and fitting into a curve by utilizing a computer algorithm;
calculating parameter values in a transfer function of a first-order and hysteresis control model in a reverse direction through the curve, and obtaining an approximate first-order hysteresis model, wherein the approximate first-order hysteresis model is a material moisture control model of the silk-making leaf-wetting machine;
the material moisture control model of the silk-making leaf-wetting machine is as follows:
wherein K is a static amplification coefficient, ts is a time constant, tau is model lag time, s is a Laplacian transformation factor, and phi(s) is a transfer function of a material moisture control model of the silk-making leaf-wetting machine.
Compared with the prior art, the invention has the beneficial effects that:
the invention discloses a method for obtaining a material moisture control model of a silk-making leaf-wetting machine through a test, which defines a stable moisture control stage of the leaf-wetting machine in a formulated form, effectively identifies a stage and a utilization scene of a stable system which can be approximated to linearization, and obtains an accurate mathematical model of the material moisture control of the silk-making leaf-wetting machine in a stable production stage, wherein the model can be used when production enters a stable state. The method for correcting the outlet water supplementing set value through cascade PID feedback can effectively stabilize the moisture control of tobacco leaf wetting process materials, and the method for correcting the moisture control stability of the defined leaf wetting machine is more towards actual conditions through the mode of connecting two single feedback PIDs in series and combining with the accumulated correction method, so that the method can more effectively accord with the processing characteristics of a tobacco cylinder device, has better realizability, can be simultaneously carried out with physical test in industry, and does not additionally waste tobacco material resources. Compared with the traditional PID control, the method can approximate the properties and parameters of the accurate mathematical model, and based on the method, the parameters determined by utilizing the tangent equation of the mathematical tool and the accurate mathematical model have higher accuracy, the accurate mathematical model is simple and has fewer parameters, and the method also has stability, stability margin and time domain quick response characteristics so as to further improve and correct the accurate mathematical model. Based on the characteristics of the accurate mathematical model, control strategies such as time lag Smith control, fuzzy control, neural network, self-adaptive control and predictive control can be adopted to replace the original PID control of equipment, so that the stability, accuracy and rapidity of material moisture control under a specific production state are effectively improved.
Drawings
FIG. 1 is a flow chart of a method for obtaining a material moisture control model of a silk-making leaf-wetting machine through a test in accordance with an embodiment of the present application;
fig. 2 is a schematic diagram of a conventional stage of moisture control of a tobacco moistening machine in a material moisture control model of a tobacco shred moistening machine obtained through a test according to a first embodiment of the present application;
FIG. 3 is a schematic diagram of a stable stage of moisture control of a tobacco moistening machine in a material moisture control model of a tobacco shred moistening machine obtained through a test according to an embodiment of the present application;
FIG. 4 is a schematic illustration of an approximate single loop process control in a test acquisition wire-making and leaf-wetting machine material moisture control model according to one embodiment of the present application;
FIG. 5 is a schematic diagram of step signals in a material moisture control model of a test acquisition silk-making leaf-wetting machine provided by the first embodiment of the application;
fig. 6 is a schematic diagram showing a step corresponding curve of a construction function f (t) in a material moisture control model of a silk-making leaf-wetting machine obtained through experiment according to an embodiment of the present application.
Detailed Description
The following detailed description of the technical solutions of the present application will be given by way of the accompanying drawings and specific embodiments, and it should be understood that the specific features of the embodiments and embodiments of the present application are detailed descriptions of the technical solutions of the present application, and not limiting the technical solutions of the present application, and that the embodiments and technical features of the embodiments of the present application may be combined with each other without conflict.
The term "and/or" is herein merely an association relationship describing an associated object, meaning that there may be three relationships, e.g., a and/or B, may represent: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.
As shown in fig. 1 to 6, the embodiment provides a method for obtaining a material moisture control model of a silk-making leaf-wetting machine through a test, which comprises the following steps:
step one: entering a production stage when the leaf wetting machine meets production conditions;
firstly, judging whether the loose leaf wetting machine starts production, if so, executing downwards, and if not, continuing to return to wait until the production condition is met. And entering a production stage when the loosening and leaf wetting machine meets production conditions.
Step two: the method comprises the steps of controlling moisture of a leaf wetting machine in a production stage, and defining a stable stage of moisture control of the leaf wetting machine in a formulated form;
the inlet water adding control and the outlet water supplementing control in the corresponding moisture control loop of the leaf wetting machine are controlled by adopting a single closed-loop negative feedback PID (proportional integral differential controller), and the hot air control, the moisture discharging negative pressure control and the direct injection steam control which indirectly affect the moisture of the outlet material in the leaf wetting machine are also controlled by adopting the single closed-loop negative feedback PID. The set values SP in each PID control module are defined as preset set values (equipment parameters or recipe parameters) of each control loop in the production phase, as shown in fig. 2. The whole production process is carried out in a relatively stable feedback mode, when the outlet infrared moisture meter detects that the outlet has a material moisture value, the outlet water supplementing and adding control affecting the outlet material moisture is locked to be a main material moisture control loop, the preset set value of the outlet water supplementing and adding PID loop is canceled, the outlet material moisture value is fed back to the SP value of the outlet water supplementing and adding PID control loop in a PID cascade mode to carry out closed-loop control, and the SP value is shown in figure 3.
The specific method comprises the following steps: newly adding an outlet material moisture 6 # PID loop, the outlet material moisture value is used as the actual value PV of the PID 6 The standard value of the water content of the outlet material required by the process is used as the set value SP of the PID 6 PID outputs a process value CV ranging from-100% to +100% 6 Then, the adjust value is obtained through a simple conversion formula. The adjust value calculates a correction value for each operation period, and is used for correcting the preset water adding quantity setting value of the outlet in real time so as to fulfill the aim of accurate control.
The calculation formula of the adjust value is:
adjust＝CV 6 *K；
wherein K is a correction coefficient of cascade PID, and the adjust value calculates a correction value, CV, for each calculation period 6 For discharging water 6 # Process values of the PID loop.
Combine the adjust value with the exitAdding the preset water adding quantity setting value to obtain the real-time outlet water adding quantity setting value and assigning the real-time outlet water adding quantity setting value to the SP 2 . The outlet water adding quantity real-time setting value=adjust+outlet water adding quantity preset setting value
＝CV 6 * K+ outlet water adding quantity preset set value.
Then, waiting for the moisture control of the leaf-wetting machine to enter a stable phase. In the method, the moisture control stabilization stage of the leaf wetting machine is defined as follows: inlet water adding control 1 in corresponding outlet material water control loop of leaf wetting machine # PID loop and outlet water supplementing and adding control 2 # The PID loop enters a moisture control steady state.
At this stage, a threshold value TV is defined 1 ～TV 17 Threshold value TV 1 ～TV 17 The value range comparison type parameters are respectively used for judging whether the equipment enters the moisture control stabilization stage of the leaf wetting machine and are set by a user according to debugging experience. Wherein the threshold value TV 1 、TV 2 And TV 5 Correspond to 1 # PID loop, threshold value TV 3 、TV 4 And TV 6 Correspond to 2 # PID loop, threshold value TV 7 、TV 8 And TV 13 Corresponds to 3 # PID loop, threshold value TV 9 、TV 10 And TV 14 Corresponds to 4 # PID loop, threshold value TV 11 、TV 12 And TV 15 Corresponding to 5 # PID loop, threshold value TV 16 And TV 17 Corresponding to the outlet moisture related value.
Defining a time length parameter time 1 ～time 11 Time length parameter time 1 ～time 11 The time length comparison type parameter is used for judging whether the equipment enters the moisture control stabilization stage of the leaf wetting machine or not respectively, and is set by a user according to debugging experience. Wherein time is 1 And time 3 Correspond to 1 # PID loop, time 2 And time 3 Correspond to 2 # PID loop, time 4 And time 7 Corresponds to 3 # PID loop, time 5 And time 8 Corresponds to 4 # PID loop, time 6 And time 9 Corresponding to 5 # PID loop, time 10 And time 11 Corresponding to the outlet moisture related value.
Wherein the duration is time 1 Inlet water addition control 1 during the time of (2) # Set point SP of PID loop 1 Subtracting the actual value PV 1 The absolute value of the difference of the means of (a) is below the threshold value TV 1 And the duration is time 1 Actual value PV over time of (a) 1 Standard deviation SD of 1 Below threshold value TV 2 。
Duration is time 2 Outlet water make-up and water addition control 2 in the time of (2) # Set point SP of PID loop 2 Subtracting the actual value PV 2 The absolute value of the difference of the means of (a) is below the threshold value TV 3 And the duration is time 2 Actual value PV over time of (a) 2 Standard deviation SD of 2 Below threshold value TV 4 。
The description based on the mathematical formula is:
control 1 for inlet Water addition # PID loop with duration time 1 Is within the time of (1):
in the method, in the process of the invention,actual value of inlet water addition PV for moisture control stabilization stage of leaf-wetting machine 1 Mean, SP of (V) 1 Set value of water adding amount for inlet of moisture control stable stage of leaf wetting machine, TV 1 Inlet water-adding control 1 for moisture control stabilization stage of leaf-wetting machine # A threshold value of the PID loop;
the calculation formula of (2) is as follows:
wherein n is 1 Actual value of inlet water addition PV for moisture control stabilization stage of leaf-wetting machine 1 Is set in the number of (3),actual value of inlet water addition PV for moisture control stabilization stage of leaf-wetting machine 1 Is the sum of (3);
SD 1 the calculation formula of (2) is as follows:
in SD (secure digital) 1 Actual value of inlet water addition PV for moisture control stabilization stage of leaf-wetting machine 1 Standard deviation of X i Actual value of inlet water addition PV for moisture control stabilization stage of leaf-wetting machine 1 Is a single sample value of (1);
duration is time 1 SD in (a) time period 1 ＜TV 2 ；TV 2 Inlet water-adding control 1 for moisture control stabilization stage of leaf-wetting machine # A threshold value of the PID loop;
water replenishing and adding control 2 for outlet # PID loop with duration time 2 Is within the time of (1):
in the method, in the process of the invention,the average value, SP, of the actual value PV2 of the outlet water supply quantity in the stabilizing stage of the moisture control of the leaf wetting machine 2 Set value of outlet water supplementing quantity for moisture control and stabilization stage of leaf wetting machine, TV 3 Water supplementing and adding control 2 for outlet water supplementing and adding control 2 for moisture control stabilization stage of leaf wetting machine # A threshold value of the PID loop;
the calculation formula of (2) is as follows:
wherein n is 2 Actual value PV of outlet make-up water for moisture control stabilization stage of leaf-wetting machine 2 Is set in the number of (3),actual value PV of outlet make-up water for moisture control stabilization stage of leaf-wetting machine 2 Is the sum of (3);
SD 2 the calculation formula of (2) is as follows:
in SD (secure digital) 2 Actual value PV of outlet make-up water for moisture control stabilization stage of leaf-wetting machine 2 Standard deviation of Y i Actual value PV of outlet make-up water for moisture control stabilization stage of leaf-wetting machine 2 Is a single sample value of (1);
duration is time 2 SD in (a) time period 2 ＜TV 4 ；TV 4 Water supplementing and adding control 2 for outlet water supplementing and adding control 2 for moisture control stabilization stage of leaf wetting machine # Threshold of PID loop.
Meanwhile, the stabilization phase also needs to satisfy: the inlet water adding control is kept relatively stable and the outlet water supplementing water adding control is kept relatively stable; the hot air control, the moisture removal negative pressure control and the direct injection steam control are kept relatively stable.
The inlet water adding control is relatively stable and comprises an inlet water adding control 1 # Output value CV of PID loop 1 Remain below threshold TV 5 And for a corresponding period of time, the outlet water replenishing and adding control is relatively stable and comprises an outlet water replenishing and adding control 2 # Output value CV of PID loop 2 Remain below threshold TV 6 And continues for a corresponding period of time.
The description based on the mathematical formula is:
CV 1 ＜TV 5 and the duration exceeds time 3 ；
CV 2 ＜TV 6 And the duration exceeds time 3 ；
In CV 1 Inlet water-adding control 1 for moisture control stabilization stage of leaf-wetting machine # Output value, CV, of PID loop 2 Water supplementing and adding control 2 for outlet water supplementing and adding control 2 for moisture control stabilization stage of leaf wetting machine # Output value of PID loop, TV 5 Inlet water-adding control 1 for moisture control stabilization stage of leaf-wetting machine # Threshold of PID loop, TV 6 Water supplementing and adding control 2 for outlet water supplementing and adding control 2 for moisture control stabilization stage of leaf wetting machine # Threshold of PID loop.
In addition, the hot air control, the moisture removal negative pressure control and the direct injection steam control which have indirect influence on the moisture of the outlet materials in the leaf wetting machine are required to meet the stable conditions, and the method comprises the following steps: the hot air temperature control loop 3#PID loop, the moisture removal negative pressure 4#PID loop and the direct injection steam 5#PID loop enter a moisture stable state.
Wherein the duration is time 4 Hot air temperature control 3 during the time of (2) # Set point SP of PID loop 3 Subtracting the actual value PV 3 The absolute value of the difference of the means of (a) is below the threshold value TV 7 The method comprises the steps of carrying out a first treatment on the surface of the Duration is time 4 Actual value PV over time of (a) 3 Standard deviation SD of 3 Below threshold value TV 8 The method comprises the steps of carrying out a first treatment on the surface of the Duration is time 5 Moisture removal negative pressure 4 during the time period of (2) # Set point SP of PID loop 4 Subtracting the actual value PV 4 The absolute value of the difference of the means of (a) is below the threshold value TV 9 The method comprises the steps of carrying out a first treatment on the surface of the Similarly, the duration is time 5 Actual value PV over time of (a) 4 Standard deviation SD of 4 Below threshold value TV 10 The method comprises the steps of carrying out a first treatment on the surface of the Duration is time 6 Is directly sprayed with steam 5 during the period of time # Set point SP of PID loop 5 Subtracting the actual value PV 5 The absolute value of the difference of the means of (a) is below the threshold value TV 11 The method comprises the steps of carrying out a first treatment on the surface of the Duration is time 6 Actual value PV over time of (a) 5 Standard deviation SD of 5 Below threshold value TV 12 。
The description based on the mathematical formula is:
temperature control for hot air 3 # PID loop with duration time 4 Is within the time of (1):
in the method, in the process of the invention,actual value PV of hot air temperature for moisture control stabilization stage of leaf-wetting machine 3 Mean, SP of (V) 3 Set value of hot air temperature in stable stage of moisture control of leaf wetting machine, TV 7 Hot air temperature control 3 for moisture control stabilization stage of leaf wetting machine # Threshold of PID loop.
The calculation formula of (2) is as follows:
Wherein n is 3 Actual value PV of hot air temperature for moisture control stabilization stage of leaf-wetting machine 3 Is set in the number of (3),actual value PV of hot air temperature for moisture control stabilization stage of leaf-wetting machine 3 Is a sum of (a) and (b).
SD 3 The calculation formula of (2) is as follows:
in SD (secure digital) 3 Actual value PV of hot air temperature for moisture control stabilization stage of leaf-wetting machine 3 Standard deviation of W i Temperature of hot air in stable stage for moisture control of leaf wetting machineActual value PV of (2) 3 Is a single sample value of (a).
Duration is time 4 SD in (a) time period 3 ＜TV 8 ；TV 8 Hot air temperature control 3 for moisture control stabilization stage of leaf wetting machine # Threshold of PID loop.
For moisture removal negative pressure 4 # PID loop with duration time 5 Is within the time of (1):
in the method, in the process of the invention,actual value PV of moisture removal negative pressure for moisture control stabilization stage of leaf wetting machine 4 Mean, SP of (V) 4 Set value of moisture removal negative pressure in stable stage of moisture control of leaf wetting machine, TV 9 Moisture removal negative pressure 4 for moisture control and stabilization stage of leaf wetting machine # Threshold of PID loop.
The calculation formula of (2) is as follows: />
Wherein n is 4 Actual value PV of moisture removal negative pressure for moisture control stabilization stage of leaf wetting machine 4 Is set in the number of (3),actual value PV of moisture removal negative pressure for moisture control stabilization stage of leaf wetting machine 4 Is a sum of (a) and (b).
SD 4 The calculation formula of (2) is as follows:
in SD (secure digital) 4 Actual value PV of moisture removal negative pressure for moisture control stabilization stage of leaf wetting machine 4 Standard deviation of Z i Actual value PV of moisture removal negative pressure for moisture control stabilization stage of leaf wetting machine 4 Is a single sample value of (a).
Duration is time 5 SD in (a) time period 4 ＜TV 10 。TV 10 Moisture removal negative pressure 4 for moisture control and stabilization stage of leaf wetting machine # Threshold of PID loop.
For direct injection of steam 5 # PID loop, duration is time6 time:
in the method, in the process of the invention,actual value PV of direct-injection steam for moisture control stabilization stage of leaf-wetting machine 5 Mean, SP of (V) 5 Set value of direct-injection steam for moisture control stabilization stage of leaf wetting machine, TV 11 Direct injection steam 5 for moisture control stabilization stage of leaf-wetting machine # Threshold of PID loop.
The calculation formula of (2) is as follows:
wherein n is 5 Actual value PV of direct-injection steam for moisture control stabilization stage of leaf-wetting machine 5 Is set in the number of (3),actual value PV of direct-injection steam for moisture control stabilization stage of leaf-wetting machine 5 Is a sum of (a) and (b).
SD 5 Is of the meter(s)The calculation formula is as follows:
in SD (secure digital) 5 Actual value PV of direct-injection steam for moisture control stabilization stage of leaf-wetting machine 5 Standard deviation of G i Actual value PV of direct-injection steam for moisture control stabilization stage of leaf-wetting machine 5 Is a single sample value of (a).
Duration is time 6 SD in (a) time period 5 ＜TV 12 ，TV 12 Direct injection steam 5 for moisture control stabilization stage of leaf-wetting machine # Threshold of PID loop.
Meanwhile, the stabilization phase also needs to satisfy: the control of the hot air temperature control loop, the opening of the moisture removal negative pressure valve and the control of the direct injection steam control loop are kept relatively stable; and keeping the moisture of the material at the outlet of the leaf wetting machine in a stable and controlled state.
Hot air temperature control 3 # Output value CV of PID loop 3 Remain below threshold TV 13 And last for time 7 The long time represents that the control of the hot air temperature control loop is relatively stable. Moisture removal negative pressure 4 # Output value CV of PID loop 4 Remain below threshold TV 14 And last for time 8 The time of the length represents that the opening of the moisture removal negative pressure valve is relatively stable. Direct injection steam 5 # Output value CV of PID loop 5 Remain below threshold TV 15 And last for time 9 The long time represents that the control of the direct injection steam control loop is relatively stable.
The description based on the mathematical formula is:
CV 3 ＜TV 13 and the duration exceeds time 7 ；
CV 4 ＜TV 14 And the duration exceeds time 8 ；
CV 5 ＜TV 15 And the duration exceeds time 9 ；
In CV 3 For controlling the temperature of hot air 3 # Output value of PID loop，CV 4 For removing damp and negative pressure 4 # Output value, CV, of PID loop 5 For directly spraying steam 5 # Output value of PID loop, TV 13 For controlling the temperature of hot air 3 # Threshold of PID loop, TV 14 For removing damp and negative pressure 4 # Threshold of PID loop, TV 15 For directly spraying steam 5 # Threshold of PID loop.
In addition to this, the stabilization phase needs to satisfy: the moisture of the material at the outlet of the leaf wetting machine is in a stable and controlled state with small fluctuation. Actual value Vtemp of the required outlet material temperature real And the controlled demand value Vtemp set The absolute value of the difference of (c) remains below the threshold value TV 16 And continuing for a corresponding period of time; actual value Vmos of outlet material moisture real And the controlled demand value Vmos set The absolute value of the difference of (c) remains below the threshold value TV 17 And continues for a corresponding period of time.
The description based on the mathematical formula is:
|Vtemp real -Vtemp set |＜TV 16 and the duration exceeds time 10 ；
|Vmos real -Vmos set |＜TV 17 And the duration exceeds time 11 ；
In TV, TV 16 And TV 17 For the corresponding outlet moisture related value, vtemp real As actual value of outlet material temperature, vtemp set Is the controlled requirement value of the outlet material temperature, vmos real For the actual value of the outlet material moisture, vmos set Is the controlled requirement value of the moisture of the outlet material.
And the water control stable stage of the leaf wetting machine is defined only when all the conditions and the mathematical formulas are satisfied.
Step three: when the moisture control of the tobacco leaf wetting machine enters a stable stage, a nonlinear time-varying system is approximated to a linear steady system, and a material moisture control model of the tobacco leaf wetting machine is obtained.
Only when the system enters the moisture control stabilization stage of the tobacco leaf making machine, the nonlinear time-varying system can be approximated to be a linearization stabilizing system, and a linearization accurate control model of the moisture control stabilization stage, namely a material moisture control model of the tobacco leaf making machine, can be obtained through a complex method.
Since in the previous step, the outlet water is supplied with water 2 # The PID loop is used as a unique feedback control path for controlling the water content of the outlet material, and the water content value of the outlet material is fed back to the SP value of the outlet water supplementing and adding PID control loop in a PID cascading mode to carry out closed-loop control. The speed of the outlet water supplementing PID output control water supplementing pump frequency directly controls the water content of the outlet materials. At this time, the overall leaf-wetting machine outlet material moisture control is reduced to a single process control, as shown in block 4. Water supplementing and adding control 2 due to outlet # The output of PID loop controls the change of water content in the outlet material, which is non-oscillating, monotonous, with delay and inertia, and has self-balancing ability, belonging to self-constant process. Meanwhile, based on the output step characteristic curve of the water supplementing pump frequency for the output control of the PID of the water supplementing and adding of the outlet, the water content of the outlet material presents the shape and characteristic consideration of the corresponding curve of the step, and the control process can be approximately used as a first-order lag model for accurate acquisition and accurate verification.
In the automatic control principle, the transfer function of a first-order hysteresis control model is as follows:
wherein K is a static amplification coefficient, ts is a time constant, tau is model lag time, s is a Laplacian transformation factor, and phi(s) is a transfer function of a material moisture control model of the silk-making leaf-wetting machine.
After the Laplace inverse transformation is carried out, under the action of the step disturbance quantity A, the time characteristic function is as follows:
where y (t) is a time characteristic function and t is time.
The general shape of the function curve is shown in fig. 5.
The method of the invention controls the output of the frequency value of the water supplementing pump by adding water to the outlet water to a fixed increment value, simulates a stable step signal and records the water content vm os of the outlet material real 'data over time t' and fitted to a curve using a computer algorithm. The values of the K, T and tau parameters in the transfer function of the first-order hysteresis control model are calculated reversely through the curve, so that an approximate first-order hysteresis model is obtained.
The specific method comprises the following steps: firstly, calculating the average value of the frequency value of the output water-supplementing pump of the output water-supplementing control PID loop of the moisture control stabilization stage of the leaf-wetting machineThe calculation formula is as follows:
wherein n is 6 The number of the frequency value data of the water supplementing pump is output for controlling the water supplementing and adding of the outlet of the moisture control and stabilization stage of the leaf wetting machine, Is the sum of the actual values of the frequency values of the water supplementing pump, < >>And outputting a mean value of the frequency values of the water supplementing pump by the PID loop for controlling water supplementing and adding at the outlet of the moisture control stabilization stage of the leaf wetting machine.
Then, calculating the average value of the moisture of the outlet materials in the moisture control and stabilization stage of the leaf wetting machineThe calculation formula is as follows:
in the method, in the process of the invention,for controlling the water average value of the outlet material in the stable stage of the moisture control of the leaf wetting machine, n 7 For the moisture control of the leaf wetting machine, the number of the actual value data of the moisture of the outlet material in the stable stage is +.>Is the sum of the actual values of the moisture of the outlet materials.
If it isThen an increment P is given and accumulated to +.>On value and keep the outlet water supplementing and adding control 2 # The PID loop is in a manual state and outputs CV 2 The value is always +.>A step signal with a step value P is simulated and always acts steadily on the system output as shown in fig. 5. Recording outlet material moisture Vmos real ' data over time t, and calculate Vmos real ' moisture control of leaf-wetting machine stabilization stage outlet material moisture average valueIs defined as the data y. The definition formula for y is:
wherein y is the difference between the actual value of the moisture of the outlet material in the moisture control stabilization stage of the leaf wetting machine and the average value of the moisture of the outlet material in the moisture control stabilization stage, and vm os real ' is the actual value of the outlet material moisture of the moisture control stabilization stage of the leaf wetting machine.
The y value is recorded according to the continuous action of the step signal, and a curve is fitted to the coordinate with the time t as the abscissa, and the approximate shape of the curve is shown in fig. 6.
The numerical tool is used for calculating K, T and tau three parameter values in a first-order plus hysteresis control model transfer function, and the method is as follows:
the value of K is first defined and,
wherein K is a static amplification factor, y (infinity) is a steady state value of a corresponding curve of a step, and A is a step disturbance increment value.
Defining a function f (t) again to let
Since the model of first-order hysteresis has self-balancing capability, the method belongs to a self-constant process. The step must, accordingly, converge to a fixed value, the value of which is defined as y (+. defining the ratio of y (t) to y (++) as a function f (t), the formula of the function f (t) is:
where f (t) is the ratio of the time characteristic function y (t) to the steady state value y (≡) of the step corresponding curve.
As shown in fig. 6, a point D is found on the curve f (t), and the tangential slope value of the over-changed point is the maximum. From the mathematical integral correlation knowledge, it can be deduced that f (t) has a slope of zero at the origin, and as the value of t increases, the slope gradually increases until the point D is reached to be the maximum value of the slope. After passing the point D, the slope gradually decreases as the value of t increases, and approaches y (≡), the slope approaches zero.
In the method of the invention, because the recorded value of the automatic control system is the sampling value at fixed time intervals, a standardized algorithm is needed to calculate the coordinate value of the point D and the tangential slope value of the passing point D with higher accuracy, and the method is as follows:
starting point of data recording at t=0, recording f (t) value every time interval Ts time, and storing into array a [ a ] 1 ,a 2 ,a 3 ,…,a n ]Wherein array a contains n sample data. Then subtracting the previous value from the next value of array A to define a new array B [ B ] 1 ,b 2 ,b 3 ,…,b (n-1) ]Wherein b 1 ＝a 2 -a 1 ，b 2 ＝a 3 -a 2 ，b 3 ＝a 4 -a 3 ，…，b (n-1) ＝a n -a (n-1) Array B contains n-1 samples of data. Dividing each data of the array B to obtain an array C [ C ] 1 ,c 2 ,c 3 ,…,c (n-1) ]Wherein c 1 ＝b 1 /Ts，c 2 ＝b 2 /Ts，c 3 ＝b 3 /Ts，…，c (n-1) ＝b (n-1) Ts, array C contains n-1 sample data.
In general, ts is set to be about 1 second in length, so the largest data unit in the array C is directly found and defined as the point D, and the definition formula of the tangential slope kd of the point D is:
kd＝max(c 1 ,c 2 ,c 3 …c (n-1) )＝c d ；
in the formula, the max () function is a maximum value function commonly required in statistics, c d Represents the data unit of the array Cmax, d is the sequence number corresponding to the data unit of the array Cmax, wherein 1<d<(n-1)。
At the same time, the following continuous conditional inequality should also be satisfied:
c 1 ≤c 2 ≤c 3 ...≤c d ≥...≥c (n-3) ≥c (n-2) ≥c (n-1) ；
if the continuous inequality is not satisfied, the model error is too large, and the conditions and parameters of the moisture control stable stage of the leaf wetting machine need to be re-planned, and the step response test is re-carried out until the maximum tangential slope point D of the precise first-order hysteresis transfer function and the continuous condition inequality can be obtained.
D point coordinates areWherein, ts is the abscissa value of the D point, representing the (d+1) th data in the array A, +.>The ordinate value of the point D is substituted into the corresponding value of the f (t) function.
From this, the tangential function g (x) passing through the point D is expressed as:
substituting the coordinates (τ, 0) of the point B into the expression of g (x), and solving τ to obtain the formula:
in the above equation, the τ value is calculated from the above equation, except that τ value is a known value.
Substituting the coordinate (T+τ, 1) of the point A into the expression of g (x) to obtain T, and obtaining the formula:
the formula can be derived:
the above equations, except for the T value, are all known quantities, and the T value can be found from the above equations.
From this, the transfer function of the silk making and leaf wetting machine material moisture control model is:
the values of the parameter K, the parameter T and the parameter tau are all obtained. Therefore, the material moisture control model of the silk-making leaf-wetting machine under the special production stable mode can be obtained.
It should be noted that, when the method is used for field test and MATLAB simulation in Hangzhou cigarette factories, the effective parameter combination is adopted as follows: TV set 1 ＝1.0；TV 2 ＝0.3；TV 3 ＝0.3；TV 4 ＝0.2；TV 5 ＝5.0％；TV 6 ＝5.0％；TV 7 ＝3.0；TV 8 ＝0.3；TV 9 ＝0.5；TV 10 ＝0.2；TV 11 ＝0.9；TV 12 ＝0.2；TV 13 ＝TV 14 ＝TV 15 ＝5.0％；TV 16 ＝1；TV 17 ＝0.5；time 1 ＝time 2 ＝time 3 ＝200s；time 4 ＝time 5 ＝time 6 ＝time 7 ＝time 8 ＝time 9 ＝150s；time 10 ＝time 11 ＝250s；A＝20％。
In summary, the embodiment provides a method for obtaining a material moisture control model of a silk-making leaf-wetting machine through experiments, which defines a stable moisture control stage of the leaf-wetting machine in a formulated form, effectively identifies a stage and a utilization scene of a stable system which can be approximately linearized, obtains an accurate mathematical model of the material moisture control of the silk-making leaf-wetting machine in a stable production stage, and can be used when the silk-making leaf-wetting machine is produced to enter a stable state. The method for correcting the outlet water supplementing set value through cascade PID feedback can effectively stabilize the moisture control of tobacco leaf wetting process materials, and the method for correcting the moisture control stability of the defined leaf wetting machine is more towards actual conditions through the mode of connecting two single feedback PIDs in series and combining with the accumulated correction method, so that the method can more effectively accord with the processing characteristics of a tobacco cylinder device, has better realizability, can be simultaneously carried out with physical test in industry, and does not additionally waste tobacco material resources. Compared with the traditional PID control, the method can approximate the properties and parameters of the accurate mathematical model, and based on the method, the parameters determined by utilizing the tangent equation of the mathematical tool and the accurate mathematical model have higher accuracy, the accurate mathematical model is simple and has fewer parameters, and the method also has stability, stability margin and time domain quick response characteristics so as to further improve and correct the accurate mathematical model. Based on the characteristics of the accurate mathematical model, control strategies such as time lag Smith control, fuzzy control, neural network, self-adaptive control and predictive control can be adopted to replace the original PID control of equipment, so that the stability, accuracy and rapidity of material moisture control under a specific production state are effectively improved.
The foregoing is merely a preferred embodiment of the present invention, and it should be noted that modifications and variations could be made by those skilled in the art without departing from the technical principles of the present invention, and such modifications and variations should also be regarded as being within the scope of the invention.
Claims (10)
1. A method for obtaining a material moisture control model of a silk-making leaf-wetting machine through a test is characterized by comprising the following steps:
entering a production stage when the leaf wetting machine meets production conditions;
the method comprises the steps of controlling moisture of a leaf wetting machine in a production stage, and defining a stable stage of moisture control of the leaf wetting machine in a formulated form;
when the moisture control of the tobacco leaf wetting machine enters a stable stage, a nonlinear time-varying system is approximated to a linear steady system, and a material moisture control model of the tobacco leaf wetting machine is obtained.
2. The method for obtaining a model for controlling moisture of a material in a silk-making leaf-wetting machine according to claim 1, wherein the step of controlling moisture of the leaf-wetting machine in the production stage comprises:
controlling inlet water adding control, outlet water supplementing water adding control, hot air control, moisture discharging negative pressure control and direct injection steam control in a moisture control loop of the leaf wetting machine by adopting a PID control module;
The set point SP in the PID control module is defined as a preset set point of the moisture control loop in the production phase, said preset set point comprising equipment parameters and/or recipe parameters.
3. The method for obtaining a model of controlling moisture in a material of a silk-making leaf-wetting machine according to claim 2, wherein the controlling moisture in the leaf-wetting machine in the production stage further comprises:
when the infrared moisture meter at the outlet detects that the outlet has the material moisture value, controlling the water supplementing and adding of the outlet as a main material moisture control loop; the outlet water supplementing and adding control is used for controlling the water content of the outlet materials;
and canceling a preset set value of the outlet water supplementing and adding control loop, feeding back the water content value of the outlet material to a set value SP of the outlet water supplementing and adding PID control loop in a PID cascade mode, and performing closed-loop control.
4. A method of experimentally obtaining a model of the moisture control of a material in a wire-making and leaf-wetting machine according to claim 3, wherein the definition of the stabilization phase of the moisture control of the leaf-wetting machine includes:
inlet water adding control 1 in corresponding outlet material water control loop of leaf wetting machine # PID loop and outlet water supplementing and adding control 2 # The PID loop enters a moisture control stable state;
Wherein the duration is time 1 Inlet water addition control 1 during the time of (2) # Set point SP of PID loop 1 Subtracting the actual value PV 1 The absolute value of the difference of the means of (a) is below the threshold value TV 1 And the duration is the actual value PV within time1 1 Standard deviation SD of 1 Below threshold value TV 2 ；
Duration is time 2 Outlet water make-up and water addition control 2 in the time of (2) # Set point SP of PID loop 2 Subtracting the actual value PV 2 The absolute value of the difference of the means of (a) is below the threshold value TV 3 And the duration is time 2 Actual value PV over time of (a) 2 Standard deviation SD of 2 Below threshold value TV 4 。
5. The method for obtaining a model for controlling moisture in a material of a silk-making and leaf-wetting machine according to claim 4, wherein the defined formula of the stable phase of moisture control of the leaf-wetting machine comprises:
control 1 for inlet Water addition # PID loop with duration time 1 Is within the time of (1):
in the method, in the process of the invention,actual value of inlet water addition PV for moisture control stabilization stage of leaf-wetting machine 1 Mean, SP of (V) 1 Set value of water adding amount for inlet of moisture control stable stage of leaf wetting machine, TV 1 Inlet water-adding control 1 for moisture control stabilization stage of leaf-wetting machine # A threshold value of the PID loop;
the calculation formula of (2) is as follows:
wherein n is 1 Actual value of inlet water addition PV for moisture control stabilization stage of leaf-wetting machine 1 Is set in the number of (3),actual value of inlet water addition PV for moisture control stabilization stage of leaf-wetting machine 1 Is the sum of (3);
SD 1 the calculation formula of (2) is as follows:
wherein S isD 1 Actual value of inlet water addition PV for moisture control stabilization stage of leaf-wetting machine 1 Standard deviation of X i Actual value of inlet water addition PV for moisture control stabilization stage of leaf-wetting machine 1 Is a single sample value of (1);
duration is time 1 SD in (a) time period 1 ＜TV 2 ；TV 2 Inlet water-adding control 1 for moisture control stabilization stage of leaf-wetting machine # A threshold value of the PID loop;
water replenishing and adding control 2 for outlet # PID loop with duration time 2 Is within the time of (1):
in the method, in the process of the invention,actual value PV of outlet make-up water for moisture control stabilization stage of leaf-wetting machine 2 Mean, SP of (V) 2 Set value of outlet water supplementing quantity for moisture control and stabilization stage of leaf wetting machine, TV 3 Water supplementing and adding control 2 for outlet water supplementing and adding control 2 for moisture control stabilization stage of leaf wetting machine # A threshold value of the PID loop;
the calculation formula of (2) is as follows:
wherein n is 2 Actual value PV of outlet make-up water for moisture control stabilization stage of leaf-wetting machine 2 Is set in the number of (3),actual value PV of outlet make-up water for moisture control stabilization stage of leaf-wetting machine 2 Is the sum of (3);
SD 2 calculation of (2)The formula is:
in SD (secure digital) 2 Actual value PV of outlet make-up water for moisture control stabilization stage of leaf-wetting machine 2 Standard deviation of Y i Actual value PV of outlet make-up water for moisture control stabilization stage of leaf-wetting machine 2 Is a single sample value of (1);
duration is time 2 SD in (a) time period 2 ＜TV 4 ；TV 4 Water supplementing and adding control 2 for outlet water supplementing and adding control 2 for moisture control stabilization stage of leaf wetting machine # Threshold of PID loop.
6. The method for experimentally obtaining a model of controlling the moisture of a material in a silk-making and leaf-wetting machine according to claim 5, wherein the defining of the stable phase of the moisture control of the leaf-wetting machine further comprises:
the inlet water adding control is kept relatively stable and the outlet water supplementing water adding control is kept relatively stable; the hot air control, the moisture removal negative pressure control and the direct steam injection control are kept relatively stable;
the inlet water adding control is relatively stable and comprises an inlet water adding control 1 # Output value CV of PID loop 1 Remain below threshold TV 5 The outlet water supplementing and adding control is relatively stable and comprises an outlet water supplementing and adding control 2 # Output value CV of PID loop 2 Remain below threshold TV 6 ；
The hot air temperature control loop 3 is used for keeping the hot air control, the moisture removal negative pressure control and the direct injection steam control relatively stable # PID loop, moisture removal negative pressure 4 # PID loop and direct injection steam 5 # The PID loop enters a moisture stable state;
wherein the duration is time 4 Hot air temperature control 3 during the time of (2) # Set point SP of PID loop 3 Subtracting the actual value PV 3 The absolute value of the difference of the means of (a) is below the threshold value TV 7 The method comprises the steps of carrying out a first treatment on the surface of the Duration is time 4 Actual value P in time of (2)V 3 Standard deviation SD of 3 Below threshold value TV 8 The method comprises the steps of carrying out a first treatment on the surface of the Duration is time 5 Moisture removal negative pressure 4 during the time period of (2) # Set point SP of PID loop 4 Subtracting the actual value PV 4 The absolute value of the difference of the means of (a) is below the threshold value TV 9 The method comprises the steps of carrying out a first treatment on the surface of the Duration is time 5 Actual value PV over time of (a) 4 Standard deviation SD of 4 Below threshold value TV 10 The method comprises the steps of carrying out a first treatment on the surface of the Duration is time 6 Is directly sprayed with steam 5 during the period of time # Set point SP of PID loop 5 Subtracting the actual value PV 5 The absolute value of the difference of the means of (a) is below the threshold value TV 11 The method comprises the steps of carrying out a first treatment on the surface of the Duration is time 6 Actual value PV over time of (a) 5 Standard deviation SD of 5 Below threshold value TV 12 。
7. The method for obtaining a model for controlling moisture in a material of a silk-making and leaf-wetting machine according to claim 6, wherein the defined formula for the stable phase of moisture control of the leaf-wetting machine further comprises:
CV 1 ＜TV 5 and the duration exceeds time 3 ；
CV 2 ＜TV 6 And the duration exceeds time 3 ；
In CV 1 Inlet water-adding control 1 for moisture control stabilization stage of leaf-wetting machine # Output value, CV, of PID loop 2 Water supplementing and adding control 2 for outlet water supplementing and adding control 2 for moisture control stabilization stage of leaf wetting machine # Output value of PID loop, TV 5 Inlet water-adding control 1 for moisture control stabilization stage of leaf-wetting machine # Threshold of PID loop, TV 6 Water supplementing and adding control 2 for outlet water supplementing and adding control 2 for moisture control stabilization stage of leaf wetting machine # A threshold value of the PID loop;
temperature control for hot air 3 # PID loop with duration time 4 Is within the time of (1):
in the method, in the process of the invention,actual value PV of hot air temperature for moisture control stabilization stage of leaf-wetting machine 3 Mean, SP of (V) 3 Set value of hot air temperature in stable stage of moisture control of leaf wetting machine, TV 7 Hot air temperature control 3 for moisture control stabilization stage of leaf wetting machine # A threshold value of the PID loop;
the calculation formula of (2) is as follows:
wherein n is 3 Actual value PV of hot air temperature for moisture control stabilization stage of leaf-wetting machine 3 Is set in the number of (3),actual value PV of hot air temperature for moisture control stabilization stage of leaf-wetting machine 3 Is the sum of (3);
SD 3 the calculation formula of (2) is as follows:
in SD (secure digital) 3 Actual value PV of hot air temperature for moisture control stabilization stage of leaf-wetting machine 3 Standard deviation of W i Actual value PV of hot air temperature for moisture control stabilization stage of leaf-wetting machine 3 Is a single sample value of (1);
duration is time 4 SD in (a) time period 3 ＜TV 8 ；TV 8 Hot air temperature control 3 for moisture control stabilization stage of leaf wetting machine # A threshold value of the PID loop;
For moisture removal negative pressure 4 # PID loop with duration time 5 Is within the time of (1):
in the method, in the process of the invention,actual value PV of moisture removal negative pressure for moisture control stabilization stage of leaf wetting machine 4 Mean, SP of (V) 4 Set value of moisture removal negative pressure in stable stage of moisture control of leaf wetting machine, TV 9 Moisture removal negative pressure 4 for moisture control and stabilization stage of leaf wetting machine # A threshold value of the PID loop;
the calculation formula of (2) is as follows:
wherein n is 4 Actual value PV of moisture removal negative pressure for moisture control stabilization stage of leaf wetting machine 4 Is set in the number of (3),actual value PV of moisture removal negative pressure for moisture control stabilization stage of leaf wetting machine 4 Is the sum of (3);
SD 4 the calculation formula of (2) is as follows:
in SD (secure digital) 4 Actual value PV of moisture removal negative pressure for moisture control stabilization stage of leaf wetting machine 4 Standard deviation of Z i Actual value PV of moisture removal negative pressure for moisture control stabilization stage of leaf wetting machine 4 Is a single sample value of (1);
duration is time 5 SD in (a) time period 4 ＜TV 10 ；TV 10 For controlling and stabilizing moisture of leaf-wetting machineConstant-stage moisture removal negative pressure 4 # A threshold value of the PID loop;
for direct injection of steam 5 # PID loop, duration is time6 time:
in the method, in the process of the invention,actual value PV of direct-injection steam for moisture control stabilization stage of leaf-wetting machine 5 Mean, SP of (V) 5 Set value of direct-injection steam for moisture control stabilization stage of leaf wetting machine, TV 11 Direct injection steam 5 for moisture control stabilization stage of leaf-wetting machine # A threshold value of the PID loop;
the calculation formula of (2) is as follows:
wherein n is 5 Actual value PV of direct-injection steam for moisture control stabilization stage of leaf-wetting machine 5 Is set in the number of (3),actual value PV of direct-injection steam for moisture control stabilization stage of leaf-wetting machine 5 Is the sum of (3);
SD 5 the calculation formula of (2) is as follows:
in SD (secure digital) 5 Actual value PV of direct-injection steam for moisture control stabilization stage of leaf-wetting machine 5 Standard deviation of G i Actual value of direct-injection steam for moisture control stabilization stage of leaf-wetting machinePV 5 Is a single sample value of (1);
duration is time 6 SD in (a) time period 5 ＜TV 12 ，TV 12 Direct injection steam 5 for moisture control stabilization stage of leaf-wetting machine # Threshold of PID loop.
8. The method for experimentally obtaining a model of controlling the moisture of a material in a silk-making and leaf-wetting machine according to claim 7, wherein the defining of the stable phase of the moisture control of the leaf-wetting machine further comprises:
the control of the hot air temperature control loop, the opening of the moisture removal negative pressure valve and the control of the direct injection steam control loop are kept relatively stable; keeping the moisture of the material at the outlet of the leaf wetting machine in a stable and controlled state;
the control of the hot air temperature control loop is relatively stable and comprises hot air temperature control 3 # Output value CV of PID loop 3 Remain below threshold TV 13 And last for time 7 A length of time;
the opening of the moisture-removing negative pressure valve is relatively stable and comprises moisture-removing negative pressure 4 # Output value CV of PID loop 4 Remain below threshold TV 14 And last for time 8 A length of time;
the control of the direct injection steam control loop comprises the control of the direct injection steam 5 # Output value CV of PID loop 5 Remain below threshold TV 15 And last for time 9 A length of time;
the moisture of the outlet material of the leaf wetting machine is in a stable and controlled state and comprises the actual value Vtemp of the temperature of the outlet material real And the controlled demand value Vtemp set The absolute value of the difference of (c) remains below the threshold value TV 16 The method comprises the steps of carrying out a first treatment on the surface of the Actual value Vmos of outlet material moisture real And the controlled demand value Vmos set The absolute value of the difference of (c) remains below the threshold value TV 17 。
9. The method for obtaining a model for controlling moisture in a material of a silk-making and leaf-wetting machine according to claim 8, wherein the defined formula for the stable phase of moisture control of the leaf-wetting machine further comprises:
CV 3 ＜TV 13 and the duration exceeds time 7 ；
CV 4 ＜TV 14 And the duration exceeds time 8 ；
CV 5 ＜TV 15 And the duration exceeds time 9 ；
|Vtemp real -Vtemp set |＜TV 16 And the duration exceeds time 10 ；
|Vmos real -Vmos set |＜TV 17 And the duration exceeds time 11 ；
In CV 3 For controlling the temperature of hot air 3 # Output value, CV, of PID loop 4 For removing damp and negative pressure 4 # Output value, CV, of PID loop 5 For directly spraying steam 5 # Output value of PID loop, TV 13 For controlling the temperature of hot air 3 # Threshold of PID loop, TV 14 For removing damp and negative pressure 4 # Threshold of PID loop, TV 15 For directly spraying steam 5 # Threshold of PID loop, TV 16 And TV 17 For the corresponding outlet moisture related value, vtemp real As actual value of outlet material temperature, vtemp set Is the controlled requirement value of the outlet material temperature, vmos real For the actual value of the outlet material moisture, vmos set Is the controlled requirement value of the moisture of the outlet material.
10. The method for obtaining a material moisture control model of a silk-making and leaf-wetting machine according to claim 9, wherein the method for obtaining the material moisture control model of the silk-making and leaf-wetting machine comprises the following steps:
setting a fixed increment value for the frequency value of the outlet water supplementing and adding control output water supplementing pump, and simulating the fixed increment value into a stable step signal;
recording the data of the actual value of the water content of the outlet material along with the change of time t, and fitting into a curve by utilizing a computer algorithm;
calculating parameter values in a transfer function of a first-order and hysteresis control model in a reverse direction through the curve, and obtaining an approximate first-order hysteresis model, wherein the approximate first-order hysteresis model is a material moisture control model of the silk-making leaf-wetting machine;
The material moisture control model of the silk-making leaf-wetting machine is as follows:
wherein K is a static amplification coefficient, ts is a time constant, tau is model lag time, s is a Laplacian transformation factor, and phi(s) is a transfer function of a material moisture control model of the silk-making leaf-wetting machine.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310571476.XA CN116671654A (en) | 2023-05-18 | 2023-05-18 | Method for obtaining material moisture control model of silk-making leaf-wetting machine through test |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310571476.XA CN116671654A (en) | 2023-05-18 | 2023-05-18 | Method for obtaining material moisture control model of silk-making leaf-wetting machine through test |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116671654A true CN116671654A (en) | 2023-09-01 |
Family
ID=87786381
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310571476.XA Pending CN116671654A (en) | 2023-05-18 | 2023-05-18 | Method for obtaining material moisture control model of silk-making leaf-wetting machine through test |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116671654A (en) |
-
2023
- 2023-05-18 CN CN202310571476.XA patent/CN116671654A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110101106B (en) | Moisture control method and system for dampening and humidifying process based on fuzzy feedforward feedback algorithm | |
| CN110893001B (en) | Method and system for controlling water content of outlet of loosening and dampening process | |
| CN109581870A (en) | The temperature in the kettle dynamic matrix control method of energetic material reaction kettle | |
| CN110946306B (en) | Quality control method and system based on drum-type cut tobacco moisture regain | |
| CN115336780B (en) | Loose conditioning water-adding control system based on neural network model and double parameter correction | |
| CN105388765B (en) | A kind of multivariable tdeduction prediction control method of medium-speed pulverizer | |
| CN108489015B (en) | Air conditioning system temperature control method based on pole allocation and Pade approximation | |
| CN105807632B (en) | A kind of furnace temp controller design method based on improvement dahlin algorithm | |
| CN110946313B (en) | Method and system for controlling water content of outlet of cut tobacco drying process | |
| CN105676915A (en) | Production line spraying and drying process temperature control method based on active-disturbance-rejection control (ADRC) technology | |
| CN104850151A (en) | Temperature control method for airflow type cut tobacco dryer combustion chamber | |
| CN115251445B (en) | Control method for moisture content of tobacco leaves at outlet of loosening and conditioning machine | |
| CN110013044A (en) | A method of barrel temperature is obtained by calculating KLD-2 cut-tobacco drier dehydrating amount | |
| CN111165866A (en) | Quality control method and system based on airflow type cut stem drying | |
| CN116671654A (en) | Method for obtaining material moisture control model of silk-making leaf-wetting machine through test | |
| CN106773675B (en) | Fired power generating unit Predictive function control simplifies method and its application | |
| CN112790421B (en) | Cut stem charging outlet water content control method based on sliding window prediction | |
| CN116540802A (en) | Method for obtaining material temperature control model of silk-making leaf-wetting machine through test | |
| CN115599055A (en) | Intelligent control method and system for water adding amount in silk making based on mechanism prediction model | |
| CN108363292A (en) | A kind of fired power generating unit AGC control method and device based on fuzzy control strategy | |
| CN106950835A (en) | Succinct Robust Two-Degree-of-Freedom proportional plus integral control method | |
| CN116509037A (en) | Method for identifying material temperature control model of cut-tobacco making and drying machine | |
| CN117678796A (en) | Accurate control method for outlet moisture and temperature of damping machine | |
| CN109388064B (en) | Method for predicting and controlling softening degree of Chinese herbal pieces during spray-moistening process | |
| CN111067130A (en) | Perfuming and charging precision control method and system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |