CN106295795A - A kind of copper pipe interior whorl forming qualitative forecasting method based on BP neural network algorithm - Google Patents
A kind of copper pipe interior whorl forming qualitative forecasting method based on BP neural network algorithm Download PDFInfo
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Abstract
The present invention relates to a kind of copper pipe interior whorl forming qualitative forecasting method based on BP neural network algorithm, belong to copper material female thread prediction of quality technical field.It is simple that purpose is to provide for a kind of application, quality controllable, the copper pipe female thread that efficiency is high manufactures early stage Forecasting Methodology, the present invention is with motor speed, drawing speed and 3, spinning position key element are independent variable, within a height of dependent variable of thread establish BP neutral net internal threads forming quality based on genetic algorithm and be predicted, learnt by training from discrete experimental data, complicated Mathematical Modeling Problem is converted into and solves network connection weights and the problem of threshold value, establish each main technologic parameters and the system model of forming quality inherent law during reflection interior whorl forming, thus the prediction for interior whorl forming quality and defect provides effective way.
Description
Technical field
The invention belongs to copper material female thread prediction of quality technical field, relate generally to a kind of based on BP neural network algorithm
Copper pipe interior whorl forming qualitative forecasting method.
Background technology
Requiring and 12 planning outlines according to national sustainable development, air-conditioning manufacturing industry is just towards energy-saving and environmental protection, health
Direction develop.No. two phosphorized coppers (TP2) have good heat conductivity, corrosion resistance and excellent processing characteristics and quilt because of it
It is widely used in heat exchanger, fuel system, air limiter and pump line road and other deep-draws and welding product, especially at sky
Industry is adjusted to enjoy favor especially.
TP2 inner screw thread copper pipe has good heat conductivity, diamagnetism, corrosion resistance and excellent processing characteristics, extensively should
For air-conditioning and cooling vaporizer and heat exchanger tube, refrigerator refrigerator pipes, condensing tube etc..Compared with traditional light pipe, interior
Corrugated tubing can increase heat exchange area 2～3 times, the turbulent flow in addition formed because of internal spiral thread, can improve heat exchange
Rate 20%～30%, energy-conservation 15%.But owing to the process technology of inner screw thread copper pipe requires the highest, formation mechenism is complicated, real
The generation experience that border relies primarily on workman conventional during generating gropes to determine forming parameters, adds that the processing of China sets
Standby automaticity is relatively low, the undue quality relying on operator, causes TP2 inner screw thread copper pipe in the interior whorl forming stage
The defects such as often appearance such as folding, profile of tooth are not fully filled, outer surface sawtooth wound, quality cannot be completely secured.At present, in TP2
Screw thread copper pipe mainly forms the screw thread within copper pipe by ball planet spinning.Owing to inner screw thread copper pipe forming process having
The feature that motor high speed spinning, extruding and spinning combine, its compacting mechanism is sufficiently complex, hence with the adaptation of genetic algorithm
Degree function calculates individual fitness value, sets up BP neural network prediction model based on genetic algorithm, internal threads morphoplasm
Amount is predicted having great importance.
Spinning forming process is furtherd investigate by numerous experts and scholars both domestic and external, but due to interior whorl forming technique
Complexity, the achievement in research basic source at initial stage, in infrastest and summary of experience, is formed without complete theory.The nineties
After, the emphasis of research gradually develops towards formation mechenism direction.Rotarescu analyzes contact area stressing conditions, and nip angle is big
Little and the size of steel ball and the impact of number internal threads forming quality, and define certain theory.Li Maosheng etc. propose
When utilizing circular arc drift press-in semi-infinite body under plane strain state, average contact pressure extrapolates the course of processing indirectly
The method of middle formation zone average contact pressure, discusses when steel ball is pressed into the average contact pressure of semi-infinite body with ball spinning and connects
Under touch pressure and plane strain state circular arc drift press-in semi-infinite body time average contact pressure between relation.Wang Miao etc.
By the technique study of finite element numerical simulation under different die rotating speeds the Changing Pattern of axial feed rate and the one-tenth of workpiece
Shape rule, is analyzed the distribution of ess-strain in analog result, and the choosing of feed ratio when giving thin-walled ball spinning
Take scope.The studies above analyzes ball spinning technique to shaping from the stress of light pipe ball spinning and technological parameter angle mostly
The impact of pipe fitting quality, seldom relate to compacting mechanism and stressing conditions more complicated interior whorl forming research.Jiang Shuyong decile
Analyse the forming process of thin wall cylinder longitudinal inner rib, disclosed the compacting mechanism of muscle in spinning part, but longitudinal inner rib is de-after having shaped
Mould is relatively easy.Zhang Guangliang etc. analyze fold defect Producing reason in TP2 interior whorl forming technical process, draw pipe with
There is gap between screw thread core print is to cause folding the reason formed, but this factor is not joined with concrete forming parameters
System gets up, and analyzes the most deep enough.
In interior whorl forming operation, the spinning grooving stage is the committed step affecting inner screw thread copper pipe forming quality.Interior spiral shell
Stricture of vagina ball spinning technique, in addition to the spinning feature with partial plastic forming, has been also equipped with many spies such as rolling and extruding simultaneously
Point, metal fill in teeth groove is a compacting mechanism complexity, deformation affected by the many factors such as mould, lubricating condition, Yi
There is the mechanical process of number of drawbacks in copper pipe inner surface, and geometrical condition that it is comprised, boundary condition, contact conditions are all non-thread
Property, belong to nonlinear problem category.
Finite element modelling is a kind of strong design and analysis and optimization tool for solving nonlinear problem, can be used for
Analyze and the change of part shape during prediction shaping, the deformation rule of blank, Technical Parameters on Product Quality and dimensional accuracy
Affecting laws and defect form the problem such as region.But in actual production, technological parameter, lubricating condition, the mechanics of pipe
Performances etc. all change in the moment, and adding to be simplified by geometric model, boundary condition etc. in simulation process is affected, finite element modelling
Result does not often reach the technological parameter requirement of actual production, and BP neutral net is by instructing from discrete experimental data
Practice study, the prediction of interior whorl forming quality can be converted into and solve network connection weights and the information system of Threshold, it
Can be by being connected with each other and mathematical calculation between neuron, it is established that during reaction interior whorl forming forming parameters with
The system model of inherent law between interior whorl forming quality.
Summary of the invention
In order to overcome the deficiency of background technology, the invention provides a kind of copper pipe female thread based on BP neural network algorithm
Forming quality Forecasting Methodology.During mainly establishing reflection interior whorl forming, each main technologic parameters is being advised in forming quality
The system model of rule, thus the prediction for interior whorl forming quality and defect provides effective way.
The technical solution adopted in the present invention is: a kind of copper pipe interior whorl forming quality based on BP neural network algorithm is pre-
Survey method, comprises the following steps:
S1. the determination of neural network prediction model: determine the structure of neutral net, including the network number of plies, the joint of hidden layer
Count and the input layer number of neutral net and output layer nodes, use real coding, using each layer weights and threshold value as
Gene carries out initial value coding, each neutral net correspondence item chromosome after coding；
S2. to training sample and the normalized of test samples, use the linear function Mapminmax revised by data
In the range of being mapped to [0.1,0.9]；
It is as follows that samples normalization processes computational methods:
Wherein, x is for treating normalized data；xmax, xminIt is respectively the maximum in string and minima, xiAfter normalization
Data.
S3. using genetic algorithm to carry out neutral net selecting operation, determine population scale N, stochastic generation N bar dyes
Body, determines control parameter: control parameter includes crossover probability, mutation probability and end condition, determines fitness function, adaptability
Function is used for passing judgment on the individual adaptability to environment, is trained obtaining error as just to neutral net according to fitness function
Beginning fitness value, and select the individuality that fitness is high；
S4. using individuality high for two fitness selected as parent, according to the crossover probability arranged in step S3, use
Crossover operator carries out intersection operation, carries out mutation operation according to the mutation probability arranged in step S3；
S5. according to fitness function, fitness value is calculated；
S6. check whether to meet end condition, if meeting, selecting best initial weights threshold value, calculating error update weight threshold；
S7. the error calculated according to step S6, meets the termination circulation of setting accuracy condition, it was predicted that obtain copper pipe female thread
Forming results, if not met setting accuracy condition, turn round step S6.
In the process that the present invention provides, according to 2n+1, (n is input layer to the nodes of the hidden layer described in step S1
Nodes) determine.
In the process that the present invention provides, the input layer of the neutral net described in step S1 is several to be set according to the study
Fixed independent variable number determines, the dependent variable number that the output layer nodes of described neutral net sets according to research determines.
In the process that the present invention provides, the neural network structure described in step S1 is 3-7-1 type network structure.
In the process that the present invention provides, the described independent variable set is as motor speed, drawing speed and spinning position 3
Individual independent variable.
In the process that the present invention provides, the described dependent variable set is as 1 dependent variable of female thread tooth depth.
In the process that the present invention provides, in described step S7, precision conditions is that error is less than 0.00001.
Accompanying drawing explanation
Fig. 1 is the mean square deviation obtained after neural network model is trained and tests as sample by copper material formed data.
Fig. 2 is that the inventive method predicts the outcome and measured result comparison diagram.
Detailed description of the invention
Below in conjunction with the accompanying drawing in the embodiment of the present invention, technical matters step, it is embodied as condition, the present invention is implemented
Technical scheme in example is clearly and completely described, it is clear that described embodiment is only that a part of the present invention is implemented
Example rather than whole embodiments.Based on the embodiment in the present invention, those of ordinary skill in the art are not paying creativeness
The every other embodiment obtained under work premise, broadly falls into the scope of protection of the invention.
Embodiment 1
(1) three independent variables determining BP neural network model are motor speed, drawing speed and spinning position and
Individual dependent variable female thread tooth depth, the input layer number of BP neutral net is set to 3, and output layer nodes is set to 1.
(2) nodes of hidden layer then according to Hecht-Nielsen propose empirical equation 2n+1 (n is input layer
Number), select 5,7 and 9 respectively, training objective 0.00001, learning rate 0.1.
(3) BP neutral net selects the network structure of 3-7-1.
(4) normalized to training sample and test samples makes the data of input and output be mapped in [0.1,0.9].
Training sample normalized computational methods are as follows:
Wherein, x is for treating normalized data；xmax, xminIt is respectively the maximum in string and minima, xiAfter normalization
Data.
(5) initial value used by BP neutral net is then to be selected, intersect and make a variation the phase that obtains after optimization by genetic algorithm
Closing numerical value, wherein population scale is 10, and evolution number of times is 50 times, and crossover probability is 5, and mutation probability is 0.2,
(6) formed data that orthogonal obtains is utilized as sample neural network model to be trained and survey
Examination.
Result display training sample obtains less mean square deviation after experience 13 circulation, uses this method prediction to obtain
The female thread corresponding tooth depth minimum relative error that copper material female thread correspondence tooth depth obtains with actual test is 0.08%, maximum relative
Error is 0.77%, and average relative error is 0.418%, and the gear forming quality of this method prediction possesses higher degree of accuracy.
Every technical staff's notice: although the present invention describes according to above-mentioned detailed description of the invention, but the present invention
Invention thought be not limited to that invention, the repacking of any utilization inventive concept, all will include this patent protection of the patent right in
In the range of.
Claims (7)
1. a copper pipe interior whorl forming qualitative forecasting method based on BP neural network algorithm, it is characterised in that comprise following step
Rapid:
S1. the determination of neural network prediction model: determine the structure of neutral net, including the network number of plies, the nodes of hidden layer
With input layer number and the output layer nodes of neutral net, use real coding, using each layer weights and threshold value as gene
Carry out initial value coding, each neutral net correspondence item chromosome after coding；
S2. to training sample and the normalized of test samples, the linear function Mapminmax revised is used data all to be reflected
In the range of being mapped to [0.1,0.9]；
It is as follows that samples normalization processes computational methods:
Wherein, x is for treating normalized data；xmax, xminIt is respectively the maximum in string and minima, xiNumber after normalization
According to.
S3. use genetic algorithm to carry out neutral net selecting operation, determine population scale N, stochastic generation N bar chromosome, really
Surely control parameter: control parameter includes crossover probability, mutation probability and end condition, determine fitness function, fitness function
It is used for passing judgment on the individual adaptability to environment, is trained obtaining error as initial suitable to neutral net according to fitness function
Answer angle value, and select the individuality that fitness is high；
S4. using individuality high for two fitness selected as parent, according to the crossover probability arranged in step S3, use and intersect
Operator carries out intersection operation, carries out mutation operation according to the mutation probability arranged in step S3；
S5. according to fitness function, fitness value is calculated；
S6. check whether to meet end condition, if meeting, selecting best initial weights threshold value, calculating error update weight threshold；
S7. the error calculated according to step S6, meets the termination circulation of setting accuracy condition, it was predicted that obtain the one-tenth of copper pipe female thread
Shape result, if not met setting accuracy condition, turns round step S6.
2. according to claim 1 one kind copper pipe based on BP neural network algorithm interior whorl forming qualitative forecasting method, its feature
It is that the nodes of the hidden layer described in step S1 determines according to 2n+1 (n is input layer number).
3. according to claim 1 one kind copper pipe based on BP neural network algorithm interior whorl forming qualitative forecasting method, its feature
It is that the several independent variable number set according to the study of the input layer of the neutral net described in step S1 determines, described nerve
The dependent variable number that the output layer nodes of network sets according to research determines.
4. according to claim 1 one kind copper pipe based on BP neural network algorithm interior whorl forming qualitative forecasting method, its feature
It is that the neural network structure described in step S1 is 3-7-1 type network structure.
5. according to claim 3 one kind copper pipe based on BP neural network algorithm interior whorl forming qualitative forecasting method, its feature
It is that the described independent variable set is as motor speed, drawing speed and 3, spinning position independent variable.
6. according to claim 3 one kind copper pipe based on BP neural network algorithm interior whorl forming qualitative forecasting method, its feature
It is that the described dependent variable set is as 1 dependent variable of female thread tooth depth.
7. according to claim 1 one kind copper pipe based on BP neural network algorithm interior whorl forming qualitative forecasting method, its feature
It is in step S7 that precision conditions is that error is less than 0.00001.
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Cited By (6)
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| CN107391890A (en) * | 2017-09-01 | 2017-11-24 | 东营市永利精工石油机械制造有限公司 | A kind of oil bushing threaded connector machines prediction and the optimal control method for line defect of quivering |
| CN109272497A (en) * | 2018-09-05 | 2019-01-25 | 深圳灵图慧视科技有限公司 | Method for detecting surface defects of products, device and computer equipment |
| CN109886500A (en) * | 2019-03-05 | 2019-06-14 | 北京百度网讯科技有限公司 | Method and apparatus for determining processing technology information |
| CN109919941A (en) * | 2019-03-29 | 2019-06-21 | 深圳市奥特立德自动化技术有限公司 | Internal screw thread defect inspection method, device, system, equipment and medium |
| CN112528955A (en) * | 2020-12-25 | 2021-03-19 | 华中科技大学 | High-frequency element machining size precision prediction method and system |
| CN116596403A (en) * | 2023-06-14 | 2023-08-15 | 常州润来科技有限公司 | Evaluation method and system for forming quality of internal threads of copper pipe |
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Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107391890A (en) * | 2017-09-01 | 2017-11-24 | 东营市永利精工石油机械制造有限公司 | A kind of oil bushing threaded connector machines prediction and the optimal control method for line defect of quivering |
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| CN109919941A (en) * | 2019-03-29 | 2019-06-21 | 深圳市奥特立德自动化技术有限公司 | Internal screw thread defect inspection method, device, system, equipment and medium |
| CN112528955A (en) * | 2020-12-25 | 2021-03-19 | 华中科技大学 | High-frequency element machining size precision prediction method and system |
| CN112528955B (en) * | 2020-12-25 | 2022-05-13 | 华中科技大学 | High-frequency element machining size precision prediction method and system |
| CN116596403A (en) * | 2023-06-14 | 2023-08-15 | 常州润来科技有限公司 | Evaluation method and system for forming quality of internal threads of copper pipe |
| CN116596403B (en) * | 2023-06-14 | 2023-12-22 | 常州润来科技有限公司 | Evaluation method and system for forming quality of internal threads of copper pipe |
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