CN101021718A - Double-layer roll welding pipe welding process control system and control method thereof - Google Patents

Abstract

The invention relates to a double-layer brazed tube welding course control system and method, where the system comprises temperature detector, high speed photo-isolating A/D board, industrial computer and peripheral equipment, high speed photo-isolating D/A board, and executing mechanism, and the method is based on fuzzy self-adapting control method with hierarchical structure. And its beneficial effects: the system has simple structure and low cost; the system control accuracy is more improved so as to improve welding quality of the brazed tubes.

Description

Double-layer roll welding pipe welding process control system and control method thereof

Technical field

The present invention relates to a kind of double-layer roll welding pipe welding process control system and control method thereof, belong to welded tube solder technology and control method technical field thereof.

Background technology

Double coiled welded tube is widely used in fields such as automobile, household electrical appliances, the nineties, China began from the external double coiled welded tube production line of having introduced, product quality is increased, but because import equipment costs an arm and a leg, maintenance cost is higher, so domestic most producer still relies on operating personnel's experience to go to control to the main technologic parameters of welding process, be difficult to realize parameters Optimization, the welding quality of welded tube is difficult to guarantee.

Summary of the invention

Technical matters to be solved by this invention provides a kind of simple in structure, cost is low, control accuracy is high double-layer roll welding pipe welding process control system and control method thereof.

The technical solution adopted for the present invention to solve the technical problems:

Technical scheme one: double-layer roll welding pipe welding process control system

This control system is made up of temperature testing equipment, high-speed light isolation A/D plate, industrial computer and peripherals thereof, high-speed light isolation D/A plate, topworks; The output termination high-speed light of temperature testing equipment is isolated the input end of A/D plate, and high-speed light is isolated the A/D plate and is connected with industrial computer by bus, and the output terminal of industrial computer is isolated the input end that the D/A plate meets topworks through high-speed light.

Described temperature testing equipment adopts the infrared color comparison temperature measurement of optical fiber system; The infrared color comparison temperature measurement of optical fiber system is installed on the right electrode wheel place horizontal level vertical with welded tube, apart from welded tube 20-50cm place.

Described topworks adopts the silicon-controlled voltage regulation device.

Technical scheme two: double-layer roll welding pipe welding process control method

This control method is based on the fuzzy self-adaption control algolithm with hierarchy, and described hierarchy is about to The whole control system and is divided into three grades of control structures: (1) basic fuzzy control level.In order to satisfy system's requirement of real-time control, basic fuzzy control level adopts the fuzzy logic control mode.(2) self-adaptation is adjusted level.In order to adapt to controlled system parameter time varying situation, adopt the adaptive control mode, regularly online adjustment Fuzzy Controller Parameters.(3) process status is declared rank.In order to overcome the influence that process status changes (or different actual condition), improve the robust performance of control system, process status is judged as auxiliary input quantity, according to system's process status of living in, adopt corresponding Fuzzy Controller Parameters collection.

Concrete grammar step of the present invention is as follows:

One, input step:

In following parameters input industrial computer: the specification of welded tube is cross-sectional area, welding temperature expectation value, adopt the scope of selected fuzzy rule base, fuzzy domain;

Two, data acquisition step:

Gather the brazing temperature of surveying by temperature testing equipment in real time by industrial computer;

Three, calculation procedure:

Finish following calculation procedure by the industrial computer that the fuzzy adaptive algorithm with hierarchy is housed:

(1) basic fuzzy control level:

A. calculate the error e and the error rate △ e of system;

B. with the error e of system and error rate △ e by change of scale to separately domain scope;

C. the input quantity that will transform to the domain scope is carried out Fuzzy Processing, makes original accurate input quantity become fuzzy quantity;

D. pass through the fuzzy value of fuzzy reasoning calculation control amount u;

E. controlled quentity controlled variable u's is definite:

At first by the value z of the controlled amount u of method of weighted mean in domain ₀Then by change of scale with z ₀Become actual controlled quentity controlled variable u output;

(2) self-adaptation is adjusted level:

When the satisfied control of above-mentioned controlled quentity controlled variable u output requires, adopt adjustment degree of membership output valve method to carry out the self-adaptation adjustment, enter the d item in above-mentioned (1) step then, finally the output valve of Correction and Control amount u;

(3) process status is judged level:

When bigger variation takes place in system condition, change as the welded tube specification, judge the variation that is taken place by industrial computer, and select fuzzy rule base to adapt to this variation automatically;

Four, execution in step:

Controlled quentity controlled variable u adds to the two interelectrode voltages that are positioned on the welded tube by actuating mechanism controls, thereby reaches the control brazing temperature.

Described temperature testing equipment adopts the infrared color comparison temperature measurement of optical fiber system; The infrared color comparison temperature measurement of optical fiber system is installed on the right electrode wheel place horizontal level vertical with welded tube, apart from welded tube 20-50cm place.

Described topworks adopts the silicon-controlled voltage regulation device.

The invention has the beneficial effects as follows that its control system is simple in structure, cost is lower.Because its control method has adopted the Fuzzy Adaptive Control Scheme with hierarchy, has improved the control accuracy of control system greatly, thereby has improved the welding quality of welded tube.

Welding pipe welding process Analysis on Mechanism of the present invention is as follows:

When whole parameters of supposing that welding process relates to, all do not change in time as socket cross-sectional area, soldering speed, electric current, voltage, electrode contact resistance etc., thereby be constant along the Temperature Distribution of socket between two electrodes, brazing process is a steady-state process.

The present invention is directed to welding pipe welding process this retardation time of non-linear process little, that response speed is fast and analyze, adopt resistance directly-heated type heat protocol (referring to Fig. 2).

When welded tube was sentenced speed v through electrode 2 by electrode 1, two interelectrode welded tubes constituted the loop by electrode and power supply, and pipe has electric current to produce.Itself has resistance pipe, by Joule law as can be known, has heat to produce when electric current is flowed through.Adopt the mode of low-voltage, big electric current, make pipe in operational process by Fast Heating, reach desired temperature.

Welding process Temperature Distribution function:

$T=\frac{\left\{\right[1+\mathrm{\&alpha;}\&times;(t_1-20)]\&times;\exp (\frac{{\mathrm{<figure-callout\; id="2"\; label="I"\; filenames="A20061010215500121.png"\; state="\{\{state\}\}">I</figure-callout>}}^2\&times;{\mathrm{\&rho;}}_0\&times;\mathrm{\&alpha;}}{{\mathrm{\&rho;}}_1\&times;c\&times;v\&times;{\mathrm{<figure-callout\; id="2"\; label="F"\; filenames="A20061010215500121.png"\; state="\{\{state\}\}">F</figure-callout>}}^2}\&times;L)+(20\&times;\mathrm{\&alpha;}-1)\}}{\mathrm{\&alpha;}}$

In the formula: the temperature of T-electrode 2 place's pipes, the also preheat temperature that promptly will control, ℃;

t ₁The temperature at-electrode 1 place, ℃;

The I-preheat curent, A;

L-two interelectrode distances, m;

V-manages travelling speed, m/s;

C-tubing specific heat, J/kg ℃;

F-tube wall area of section, mm ²

α-tubing temperature-coefficient of electrical resistance, ℃ ^-1

ρ ₀Resistivity in the time of-20 ℃, Ω m;

ρ ₁-pipe workpiece quality density, kg/m ²

Description of drawings

Fig. 1 is the structural representation of control system of the present invention.

Fig. 2 is for adopting the principle schematic of resistance directly-heated type heat protocol.

Fig. 3 is brazing process fuzzy self-adaption control principle figure.

Fig. 4 is a software flow pattern of the present invention.

Embodiment

The embodiment of control system of the present invention as shown in Figure 1, it is isolated by temperature testing equipment, high-speed light, and A/D plate, industrial computer and peripherals thereof, high-speed light are isolated the D/A plate, topworks forms; The output termination high-speed light of temperature testing equipment is isolated the input end of A/D plate, and high-speed light is isolated the A/D plate and is connected with industrial computer by bus, and the output terminal of industrial computer is isolated the input end that the D/A plate meets topworks through high-speed light.

Described temperature testing equipment adopts optical fiber infrared color comparison temperature measurement system (model is FR1B); The infrared color comparison temperature measurement of optical fiber system is installed on right electrode wheel place (Fig. 2 is seen at the electrode 2 places) horizontal level vertical with welded tube, apart from welded tube 20-50cm place.

Described topworks adopts the silicon-controlled voltage regulation device.

The embodiment of control method of the present invention comprises following four steps:

One, input step:

In following parameters input industrial computer: the specification of welded tube is cross-sectional area, welding temperature expectation value, adopt the scope of selected fuzzy rule base, fuzzy domain;

Two, data acquisition step:

Gather the brazing temperature of surveying by temperature testing equipment in real time by industrial computer;

Three, calculation procedure:

Finish following calculation procedure by the industrial computer that the fuzzy adaptive algorithm with hierarchy is housed:

(1) basic fuzzy control level:

A. calculate the error e and the error rate △ e of system:

e＝r-y

Δe＝de/dt＝e(i)-e(i-1)/T

Wherein T is the control cycle of system, and r is an argon brazing temperature setting value, and y is the actual temperature value that temperature testing equipment detected, and e (i) is an i error constantly, and e (i-1) is an i-1 error constantly;

B. with the error e of system and error rate △ e by change of scale to separately domain scope, its general formula is:

$x_0=\frac{x_{\min }+x_{\mathrm{<figure-callout\; id="2"\; label="max"\; filenames="A20061010215500121.png"\; state="\{\{state\}\}">max</figure-callout>}}}{2}+k_I(x_0^{*}-\frac{{x^{*}}_{\min }+{x^{*}}_{\max }}{2})$

$k_I=\frac{x_{\max -}{x}_{\min }}{{x^{*}}_{\max -}{x^{*}}_{\min }}$

Wherein, k _IBe called scale factor

x ₀Input quantity for reality

 x _Min ^*, x _Max ^* is x ₀ ^*Variation range

[x _Min, x _Max] be the domain scope that requires;

C. the input quantity that will transform to the domain scope is carried out Fuzzy Processing, makes original accurate input quantity become fuzzy quantity, adopts following bell shape subordinate function:

${\mathrm{\&mu;}}_A\left(x\right)=e^{\frac{{(x-x_0)}^2}{2{\mathrm{\&sigma;}}^2}}$

X wherein ₀Be the central value of membership function, σ ²Be variance;

D. by the fuzzy value of fuzzy reasoning calculation control amount u, fuzzy reasoning adopts following formula:

Wherein, A ₁' for the linguistic variable value of representative error e

A ₂' for the linguistic variable value of representative error rate Δ e

$\underset{i=1}{\overset{n}{\mathrm{\&cup;}}}{R}_i$ Be the fuzzy implication relation that obtains according to the control law storehouse

B ' is the linguistic variable value of representative controlled quentity controlled variable u;

E. controlled quentity controlled variable u's is definite:

Obtain the value z of controlled quentity controlled variable u in domain by method of weighted mean ₀:

${\mathrm{<figure-callout\; id="0"\; label="z"\; filenames="A20061010215500121.png"\; state="\{\{state\}\}">z</figure-callout>}}_0=\mathrm{df}\left(z\right)=\frac{\underset{a}{\overset{b}{\&Integral;}}z{\mathrm{\&mu;}}_{B^{\&prime;}}\left(z\right)\mathrm{dz}}{\underset{a}{\overset{b}{\&Integral;}}{\mathrm{\&mu;}}_{B^{\&prime;}}\left(z\right)}$

By change of scale with z ₀Become actual controlled quentity controlled variable u output:

$u=\frac{u_{\min }+{\mathrm{<figure-callout\; id="2"\; label="u\; max"\; filenames="A20061010215500121.png"\; state="\{\{state\}\}">u</figure-callout>}}_{\max }}{2}+k_O(z_0-\frac{z_{\min }+z_{\max }}{2})$

$k_O=\frac{u_{\max -}{u}_{\min }}{z_{\max -}{z}_{\min }}$

Wherein, k _OBe called output-scale-factor

[z _Min, z _Max] be z ₀The domain scope

[u _Min, u _Max] be the variation range of output quantity;

(2) self-adaptation is adjusted level:

When the satisfied control of above-mentioned controlled quentity controlled variable u output requires, adopt adjustment degree of membership output valve method to carry out the self-adaptation adjustment, enter the d item in above-mentioned (1) step then, finally the output valve of Correction and Control amount u;

What adopt here is the self-adaptation adjustment of adjusting degree of membership output valve method, belongs to direct fuzzy self-adaption control:

u＝u _c(x|θ)+u _D

U wherein _c(x| θ) is

$u_c\left(x\right|\mathrm{\&theta;})=\left[\underset{l=1}{\overset{M}{\mathrm{\&Sigma;}}}{\stackrel{\&OverBar;}{y}}_1\right|\underset{i=1}{\overset{n}{\mathrm{\&Pi;}}}{\mathrm{\&mu;}}_{F_i^{\&prime;}}\left(x_i\right)\left|\right]/\left[\underset{l=1}{\overset{M}{\mathrm{\&Sigma;}}}\right|\underset{i=1}{\overset{n}{\mathrm{\&Pi;}}}{\mathrm{\&mu;}}_{F_i^{\&prime;}}\left(x_i\right)\left|\right]$

Wherein

Be state x in the l bar rule _iTo fuzzy subset F _i' degree of membership, n is the state number, M is regular number,

Be that the conclusion degree of membership is the output valve of 1 correspondence in the l bar rule; Will

As adjustable parameter, following formula can be written as:

$u_c\left(x\right|\mathrm{\&theta;})={\mathrm{\&theta;}}^T\mathrm{\&xi;}\left(x\right),{\mathrm{\&xi;}}^1\left(x\right)=\frac{\underset{i=1}{\overset{n}{\mathrm{\&Pi;}}}{\mathrm{\&mu;}}_{F_i^{\&prime;}}\left(x_i\right)}{\underset{l=1}{\overset{M}{\mathrm{\&Sigma;}}}\left|\underset{i=1}{\overset{n}{\mathrm{\&Pi;}}}{\mathrm{\&mu;}}_{F_i^{\&prime;}}\left(x_i\right)\right|}$

Wherein $\mathrm{\&theta;}={({\stackrel{\&OverBar;}{y}}_1,\&CenterDot;\&CenterDot;\&CenterDot;,{\stackrel{\&OverBar;}{y}}_M)}^T$ Be parameter vector, ξ (x)=(ξ ¹(x) ..., ξ ^M(x)) ^TBe regression vector, and ξ ¹(x) be called fuzzy basis function; u _D=k _dSgn (e ^TPb _c) be that D controls k _d〉=0, b _c=[0,0 ..., b] ^TIf, e ^TPb _c＞0, u then _D=k _dIf, e ^TPb _c＜0, u then _D=-k _d

The adaptive law of parameter vector θ is taken as:

P wherein _r[ ^*] be defined as:

$P_r=\left[{\mathrm{\&gamma;e}}^T{P}_n\mathrm{\&xi;}\left(x\right)\right]={\mathrm{\&gamma;e}}^T{p}_n\mathrm{\&xi;}\left(x\right)-{\mathrm{\&gamma;e}}^T{P}_n\frac{{\mathrm{\&theta;\&theta;}}^T\mathrm{\&xi;}\left(x\right)}{{\left|\mathrm{\&theta;}\right|}^2}$

P _nBe last row of P, | θ |≤M _θ＜∞, M _θThe limited upper bound for the θ vector;

P is a positive definite matrix and satisfies Lyapunov equation Λ ^TP+P Λ=-Q, Q is any positive definite matrix of n * n in the formula;

$\mathrm{\&Lambda;}=\left[\begin{array}{ccccc}0& 1& 0& \&CenterDot;\&CenterDot;\&CenterDot;& 0\\ 0& 0& 1& \&CenterDot;\&CenterDot;\&CenterDot;& 0\\ \&CenterDot;\&CenterDot;\&CenterDot;& \&CenterDot;\&CenterDot;\&CenterDot;& \&CenterDot;\&CenterDot;\&CenterDot;& \&CenterDot;\&CenterDot;\&CenterDot;& \&CenterDot;\&CenterDot;\&CenterDot;\\ {-k}_n& -k_{n-1}& {-k}_{n-2}& \&CenterDot;\&CenterDot;\&CenterDot;& {-\mathrm{<figure-callout\; id="1"\; label="k"\; filenames="A20061010215500121.png"\; state="\{\{state\}\}">k</figure-callout>}}_1\end{array}\right];$

(3) process status is judged level:

When bigger variation takes place in system condition, change as the welded tube specification, judge the variation that is taken place by industrial computer, and select fuzzy rule base to adapt to this variation automatically;

Four, execution in step:

Controlled quentity controlled variable u adds to the two interelectrode voltages that are positioned on the welded tube by actuating mechanism controls, thereby reaches the control brazing temperature.

Described temperature testing equipment adopts optical fiber infrared color comparison temperature measurement system (model is FR1B); The infrared color comparison temperature measurement of optical fiber system is installed on right electrode wheel place (Fig. 2 is seen at the electrode 2 places) horizontal level vertical with welded tube, apart from welded tube 20-50cm place.

Described topworks adopts the silicon-controlled voltage regulation device.

Claims (6)

1, double-layer roll welding pipe welding process control system is characterized in that it is isolated by temperature testing equipment, high-speed light that A/D plate, industrial computer and peripherals thereof, high-speed light are isolated the D/A plate, topworks forms; The output termination high-speed light of temperature testing equipment is isolated the input end of A/D plate, and high-speed light is isolated the A/D plate and is connected with industrial computer by bus, and the output terminal of industrial computer is isolated the input end that the D/A plate meets topworks through high-speed light.

2, double-layer roll welding pipe welding process control system according to claim 1 is characterized in that described temperature testing equipment adopts the infrared color comparison temperature measurement of optical fiber system; The infrared color comparison temperature measurement of optical fiber system is installed on the right electrode wheel place horizontal level vertical with welded tube, apart from welded tube 20-50cm place.

3, double-layer roll welding pipe welding process control system according to claim 2 is characterized in that described topworks adopts the silicon-controlled voltage regulation device.

4, double-layer roll welding pipe welding process control method is characterized in that:

One, input step:

In following parameters input industrial computer: the specification of welded tube is cross-sectional area, welding temperature expectation value, adopt the scope of selected fuzzy rule base, fuzzy domain;

Two, data acquisition step:

Gather the brazing temperature of surveying by temperature testing equipment in real time by industrial computer;

Three, calculation procedure:

Finish following calculation procedure by the industrial computer that the fuzzy adaptive algorithm with hierarchy is housed:

(1) basic fuzzy control level:

A. calculate the error e and the error rate Δ e of system;

B. with the error e of system and error rate Δ e by change of scale to separately domain scope;

C. the input quantity that will transform to the domain scope is carried out Fuzzy Processing, makes original accurate input quantity become fuzzy quantity;

D. pass through the fuzzy value of fuzzy reasoning calculation control amount u;

E. controlled quentity controlled variable u's is definite:

At first by the value z of the controlled amount u of method of weighted mean in domain ₀Then by change of scale with z ₀Become actual controlled quentity controlled variable u output;

(2) self-adaptation is adjusted level:

When the satisfied control of above-mentioned controlled quentity controlled variable u output requires, adopt adjustment degree of membership output valve method to carry out the self-adaptation adjustment, enter the d item in above-mentioned (1) step then, finally the output valve of Correction and Control amount u;

(3) process status is judged level:

When bigger variation takes place in system condition, change as the welded tube specification, judge the variation that is taken place by industrial computer, and select fuzzy rule base to adapt to this variation automatically;

Four, execution in step:

Controlled quentity controlled variable u adds to the two interelectrode voltages that are positioned on the welded tube by actuating mechanism controls, thereby reaches the control brazing temperature.

5, double-layer roll welding pipe welding process control method according to claim 4 is characterized in that described temperature testing equipment adopts the infrared color comparison temperature measurement of optical fiber system; The infrared color comparison temperature measurement of optical fiber system is installed on the right electrode wheel place horizontal level vertical with welded tube, apart from welded tube 20-50cm place.

6, double-layer roll welding pipe welding process control method according to claim 5 is characterized in that described topworks adopts the silicon-controlled voltage regulation device.

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