Search

CN-121989431-A - PVC plastic pipe extrusion control method and equipment thereof

CN121989431ACN 121989431 ACN121989431 ACN 121989431ACN-121989431-A

Abstract

The invention discloses a PVC plastic pipe extrusion control method and equipment thereof, wherein a database containing historical data, deviation factors and correction data is constructed, after real-time data is obtained, the database is updated through a triple verification strategy, a deviation value set is obtained through a data processing strategy, a comprehensive deviation vector is calculated by weighting, corresponding correction data is found according to indexes, equipment parameters are corrected until the deviation vector reaches the standard, and the equipment is applied to the method. And constructing a correction library, ensuring reliable data through triple verification, and dynamically updating and adapting to production. In the data processing, the deviation is captured in a multi-strategy full-dimension mode, and monitoring blind areas are eliminated. The weighting algorithm converts the multi-bias value into a unified vector, and the index strategy is fast matched with the optimal correction data, so that the manual dependence is reduced. The whole-flow closed loop control reduces batch defects, shortens downtime, enables the database to excavate the optimal process, improves production benefits and product stability, and enhances enterprise competitiveness.

Inventors

  • LI CHENG
  • ZHAO CHENG
  • HAN LI
  • MA LINA

Assignees

  • 公元管道(天津)有限公司

Dates

Publication Date
20260508
Application Date
20260122

Claims (10)

  1. The extrusion control method for the PVC plastic pipe is characterized by comprising the following steps: Constructing a correction library, wherein a historical data set, a historical deviation factor set and a corresponding correction data set are stored in the correction library; acquiring a real-time acquisition data set; Inputting each real-time data of the real-time acquisition data set into a correction library, and dynamically updating historical data, historical deviation factors and corresponding correction data according to a data verification strategy, a deviation factor verification strategy and a correction data verification strategy which are carried in the correction library; Respectively processing the real-time acquisition data sets through the data processing strategy sets to obtain deviation value sets; each deviation value in the deviation value set is weighted through a weighted comprehensive algorithm to obtain a comprehensive deviation vector, wherein the weight value of each deviation value is determined according to the influence degree of each deviation value on the product quality in the PVC extrusion process; Finding a history deviation factor corresponding to the comprehensive deviation vector in a correction library through an index strategy, and acquiring correction data corresponding to the history deviation factor; and correcting the exchange flow rates, extrusion pressures and extrusion speeds of the heating section, the melting section and the homogenizing section of the PVC plastic pipe extrusion equipment through correction data, and finishing correction when the comprehensive deviation vector is smaller than the deviation threshold value.
  2. 2. The method according to claim 1, wherein the data verification policy is to determine whether each real-time data is within a preset reasonable threshold range defined based on the history data; The deviation factor verification strategy is to perform difference solving processing on effective real-time data according to a deviation formula defined in a correction library to obtain real-time deviation data, judge whether the real-time deviation data exceeds a history deviation factor of a preset multiple, define the effective real-time deviation data as the effective real-time deviation data and write the effective real-time deviation data into the history deviation factor if the real-time deviation data does not exceed the history deviation factor of the preset multiple; the correction data verification strategy is to process effective real-time deviation data according to a defined correction formula in a correction library to obtain real-time correction data, and write the real-time correction data into a correction data set.
  3. 3. The extrusion control method of PVC plastic pipe according to claim 1, wherein the data processing strategy set comprises performing difference processing on a preset extrusion pressure value, a real-time extrusion pressure value, a preset extrusion speed value and a real-time extrusion speed value through a pressure speed deviation strategy to obtain an extrusion pressure deviation value and an extrusion speed deviation value; and carrying out difference processing on the preset inlet pipe temperature value, the real-time inlet pipe temperature value, the preset outlet pipe temperature value and the real-time outlet pipe temperature value of the heating section, the homogenizing section and the melting section through a temperature deviation strategy to obtain a heating section exchange temperature deviation value, a homogenizing section exchange temperature deviation value and a melting section exchange temperature deviation value.
  4. 4. The extrusion control method of the PVC plastic pipe according to claim 1, wherein the data processing strategy set further comprises the steps of splicing the thermal imaging image set into a thermal imaging image to be detected through a thermal imaging processing splicing strategy, and analyzing the thermal imaging image to be detected through a temperature distribution analysis strategy to obtain a thermal uniformity deviation value of the PVC plastic pipe; the thermal imaging image set comprises thermal imaging images in four circumferential directions of the PVC plastic pipe, wherein the thermal imaging images are acquired according to preset angles; The thermal imaging processing stitching strategy comprises performing thermal imaging image registration on the preprocessed thermal imaging images in four directions, realizing spatial position alignment, and adopting The fusion algorithm processes overlapping areas of adjacent thermal imaging images, and the overlapping areas are spliced in turn clockwise according to the circumference of the PVC plastic pipe to form a complete thermal imaging image to be detected; The temperature distribution analysis strategy comprises the steps of processing a thermal imaging image to be detected through an image segmentation algorithm, extracting an effective area of a PVC plastic pipe, axially dividing the effective area into a detection section according to the preset length of an extrusion direction, circumferentially dividing the effective area into a temperature detection unit according to the preset angle, extracting the temperature values of all pixel points in each detection unit, calculating the average temperature value of each detection unit, calculating the average temperature value, the axial temperature maximum deviation value and the circumferential temperature maximum deviation value of the whole PVC pipe through a temperature distribution statistical algorithm, calculating the number proportion of detection units with the statistical temperature value exceeding the preset temperature range of the surface of the PVC pipe, and calculating the axial temperature maximum deviation value, the circumferential temperature maximum deviation value and the average temperature value of the whole PVC pipe through a weighted comprehensive algorithm to obtain a thermal uniformity deviation value, wherein the axial temperature maximum deviation value, the circumferential temperature maximum deviation value and the weight value of the average temperature value of the whole PVC pipe are determined according to the sensitivity of PVC pipe molding performance to the temperature.
  5. 5. The method for controlling extrusion of PVC plastic pipes according to claim 1, wherein the data processing strategy set further comprises the steps of splicing a plurality of appearance image sets into appearance images to be detected through an appearance image processing splicing strategy, and analyzing the appearance images to be detected through a defect analysis strategy to obtain appearance deviation values of the PVC plastic pipes; The appearance image set comprises appearance images in four circumferential directions of the PVC plastic pipe, wherein the appearance images are arranged between adjacent thermal imaging images and are acquired at equal intervals with the thermal imaging images; The appearance image processing and splicing strategy comprises the steps of carrying out appearance image registration on appearance images in four directions after pretreatment, realizing space position alignment, adopting a brightness fusion algorithm to process overlapping areas of adjacent thermal imaging images, and splicing the adjacent thermal imaging images in turn clockwise according to the circumference of a PVC plastic pipe to form a complete appearance image to be detected; The defect analysis strategy comprises the steps of extracting an effective defect area of a pipe from an appearance image to be detected through an RGB color space threshold segmentation algorithm, defining a preset RGB range of a normal color of a PVC pipe, primarily judging the area exceeding the preset RGB range as a suspected defect area, carrying out morphological processing on the suspected defect area to obtain the effective defect area, classifying according to morphological characteristics of defects to obtain defect characteristics, wherein the defect characteristics comprise scratch characteristics, bubble characteristics, concave characteristics, chromatic aberration characteristics and impurity characteristics, calculating quantization parameters of each defect characteristic, wherein the quantization parameters at least comprise one of defect area, defect length and defect depth, counting the number of each defect characteristic and defect total area, and processing the number of each defect characteristic and the defect total area through a weighted comprehensive algorithm to obtain an appearance deviation value, wherein the weight value of each defect characteristic is determined according to the influence degree of the defect characteristics on the performance of the PVC plastic pipe.
  6. 6. The method for controlling extrusion of PVC plastic pipes according to claim 1, wherein the indexing strategy comprises the steps of constructing an index of historical data in a correction library, establishing a primary index based on production condition parameters of raw material model and product specification grouping, and establishing a secondary index based on a historical comprehensive deviation vector; matching the first-level index according to the current production working condition parameters, and screening out a historical data set which is the same as the current working condition; then, for the screened historical data set, calculating the overall similarity of the current comprehensive deviation vector and the historical comprehensive deviation vector, wherein the overall similarity takes a value in a range The larger the value, the closer the overall deviation; Through early-stage experiment verification, presetting a similarity threshold value, and screening out a historical data set with the overall similarity larger than or equal to the preset similarity threshold value; if the number of the data sets is equal to zero, adjusting a preset similarity threshold value, and rescreening until the number of the data sets after screening is equal to or more than one; When the number of the data sets is larger than one, selecting a historical data set with the maximum overall similarity value, and extracting corresponding correction data, wherein the correction data comprises a heating section, a melting section, an exchange flow rate adjusting value of a homogenizing section, an extrusion pressure adjusting value and an extrusion speed adjusting value of each section of flow channel.
  7. PVC plastic pipe extrusion equipment, characterized in that the equipment is applied to the PVC plastic pipe extrusion control method as claimed in any one of claims 1 to 6, and the equipment comprises: an equipment base (1) fixedly installed on the ground; a feed hopper (2); a gear box driving mechanism (3) which is positioned on the equipment base (1); The three-stage screw extrusion mechanism (4) is positioned on the equipment base (1), wherein the driving end of the gear box driving mechanism (3) is connected with one end of the three-stage screw extrusion mechanism (4), and the feed hopper (2) is positioned on the upper surface of the three-stage screw extrusion mechanism (4) close to one end of the gear box driving mechanism (3); The extrusion die (5) is fixedly arranged on the three-stage screw extrusion mechanism (4) and is used for extruding PVC materials to form PVC plastic pipes; A heating section diversion temperature adjusting mechanism (6), a melting section diversion temperature adjusting mechanism (7) and a homogenizing section diversion temperature adjusting mechanism (8) are sequentially arranged on the three-stage screw extrusion mechanism (4) along the extrusion direction of the PVC plastic pipe, and are used for controlling the heating temperature of the corresponding PVC material heating section, the constant temperature of the PVC material melting section and the heat preservation temperature of the PVC material homogenizing section; The annular collection mechanism (9) is positioned at the outlet of the extrusion die (5), the PVC plastic pipe penetrates out of the annular collection mechanism (9), and the annular collection mechanism (9) is used for monitoring the surface temperature distribution condition and the appearance change of the PVC plastic pipe.
  8. 8. PVC plastic pipe extrusion apparatus according to claim 7, wherein the three stage screw extrusion mechanism (4) comprises: an extrusion cavity (401); The heating section screw (402), the melting section screw (403) and the homogenizing section screw (404), the heating section screw (402), the melting section screw (403) and the homogenizing section screw (404) are connected in sequence and positioned in the extrusion cavity (401), One end of the heating section screw rod (402) is fixedly connected with the driving end of the gear box driving mechanism (3); The gear box driving mechanism (3) drives the heating section screw (402), the melting section screw (403) and the homogenizing section screw (404) to rotate, so that PVC materials entering from the feed hopper (2) are driven to be gradually heated, melted and homogenized and then screwed into the extrusion die (5); a pressure sensor (405) is arranged at the inlet of the extrusion die (5), and the pressure sensor (405) is used for monitoring the extrusion pressure of the three-stage screw extrusion mechanism (4); And a speed sensor (406) is arranged on the extrusion cavity (401) close to the extrusion die (5), and the speed sensor (406) is used for monitoring the extrusion speed of the three-stage screw extrusion mechanism (4).
  9. 9. The PVC plastic pipe extrusion apparatus according to claim 8, wherein the heating section diversion temperature adjusting mechanism (6), the melting section diversion temperature adjusting mechanism (7) and the homogenizing section diversion temperature adjusting mechanism (8) are identical in structure; comprises a corresponding heating section heat exchange inlet pipe (601), a melting section heat exchange inlet pipe (701) and a homogenizing section heat exchange inlet pipe (801); A heating section heat exchange conduit (602), a melting section heat exchange conduit (702), a homogenizing section heat exchange conduit (802) coiled within the lumen shell of the extrusion lumen (401); A heating section heat exchange pipe (603), a melting section heat exchange pipe (703) and a homogenizing section heat exchange pipe (803); A heating section heat exchange inlet pipe (601), a melting section heat exchange inlet pipe (701) and a homogenizing section heat exchange inlet pipe (801) are correspondingly provided with a heating section inlet pipe temperature sensor (604), a melting section inlet pipe temperature sensor (704) and a homogenizing section inlet pipe temperature sensor (804); the heating section heat exchange pipe (603), the melting section heat exchange pipe (703) and the homogenizing section heat exchange pipe (803) are correspondingly provided with a heating section pipe temperature sensor (605), a melting section pipe temperature sensor (705) and a homogenizing section pipe temperature sensor (805).
  10. 10. PVC plastic pipe extrusion apparatus according to claim 9, wherein the annular collecting mechanism (9) comprises: An annular bracket (901) the center of which is concentric with the center of the extrusion die (5); At least four thermal imaging cameras (902) for monitoring the temperature distribution information of the four surfaces of the PVC plastic pipe, wherein the four thermal imaging cameras (902) are arranged along the circumferential direction of the PVC plastic pipe 、 、 、 The directions are uniformly distributed on the inner surface of the annular bracket (901); At least four image cameras (903) for monitoring the appearance change of the four surfaces of the PVC plastic pipe, wherein the four image cameras (903) are circumferentially arranged along the PVC plastic pipe 、 、 、 The directions are uniformly distributed on the inner surface of the annular bracket (901); each thermal imaging camera (902) camera and image camera (903) is configured with a bar light source, and the light source and each thermal imaging camera (902) and image camera (903) are synchronously exposed and sampled by a pulse synchronous trigger circuit.

Description

PVC plastic pipe extrusion control method and equipment thereof Technical Field The invention relates to the technical field of computers, in particular to a PVC plastic pipe extrusion control method and equipment thereof. Background In the prior art, the control method for extruding the PVC plastic pipe only pays attention to macroscopic parameters such as extruding pressure, speed and the like, neglects heat exchange efficiency of a heating section, a melting section and a homogenizing section, causes insufficient preheating of raw materials, incapability of timely finding hidden problems such as uneven melting and the like, and finally causes defects such as pipe wall thickness deviation, surface bubbles and the like. Even if temperature monitoring or appearance detection is adopted, the temperature monitoring is also mostly carried out by adopting a single-point thermocouple, only the local temperature can be reflected, the whole circumference of the pipe cannot be covered, the appearance detection is limited by defects such as scratches, pits and the like at the rear side of the pipe, the defects such as color difference degree and bubble size are easy to miss, the judgment of the defects such as color difference degree and bubble size is lack of unified standard, and subjective misjudgment exists. And thermal imaging and appearance images are not accurately spliced and quantitatively analyzed, and millimeter-level temperature anomalies or tiny impurities cannot be captured, so that the problem of batch quality of small defect accumulation is caused. In conventional production, the judgment of whether deviation exists is based on the experience of operators, and no quantitative index is formed. The multi-dimensional deviation is not converted into a unified evaluation standard, when a plurality of parameters fluctuate simultaneously, whether the whole production state is qualified or not cannot be judged, and the evaluation of the deviation severity is lack of basis, so that the adjustment time is delayed or excessively adjusted, and the production fluctuation is aggravated. Meanwhile, when the parameters are adjusted, the operator does not have historical data support, and the operator only needs to adjust the parameters empirically and try the errors repeatedly. The correction effect is not recorded and fed back in the traditional production, the follow-up correction scheme cannot be optimized, the deviation of the same type occurs repeatedly, the production stability is poor, and the consistency of the sizes and the appearance of the pipes in different batches is low. Disclosure of Invention The invention aims to solve the technical problems of incomplete monitoring, blind correction and unstable quality of products produced in the traditional PVC extrusion production line. In order to achieve the purpose, the invention adopts one of the technical schemes that the extrusion control method of the PVC plastic pipe comprises the following steps: Constructing a correction library, wherein a historical data set, a historical deviation factor set and a corresponding correction data set are stored in the correction library; acquiring a real-time acquisition data set; Inputting each real-time data of the real-time acquisition data set into a correction library, and dynamically updating historical data, historical deviation factors and corresponding correction data according to a data verification strategy, a deviation factor verification strategy and a correction data verification strategy which are carried in the correction library; Respectively processing the real-time acquisition data sets through the data processing strategy sets to obtain deviation value sets; each deviation value in the deviation value set is weighted through a weighted comprehensive algorithm to obtain a comprehensive deviation vector, wherein the weight value of each deviation value is determined according to the influence degree of each deviation value on the product quality in the PVC extrusion process; Finding a history deviation factor corresponding to the comprehensive deviation vector in a correction library through an index strategy, and acquiring correction data corresponding to the history deviation factor; And correcting the exchange flow rates, extrusion pressures and extrusion speeds of the heating section, the melting section and the homogenizing section of the PVC plastic pipe extrusion equipment through correction data, and finishing correction when the corrected comprehensive deviation vector is smaller than a deviation threshold value. Further, the data verification policy is to determine whether each real-time data is within a preset reasonable threshold range defined based on the historical data; The deviation factor verification strategy is to perform difference solving processing on effective real-time data according to a deviation formula defined in a correction library to obtain real-time deviation data, judge