CN113977039A - Pulse consumable electrode argon arc welding molten drop transition monitoring device and control method - Google Patents
Pulse consumable electrode argon arc welding molten drop transition monitoring device and control method Download PDFInfo
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- CN113977039A CN113977039A CN202111252951.4A CN202111252951A CN113977039A CN 113977039 A CN113977039 A CN 113977039A CN 202111252951 A CN202111252951 A CN 202111252951A CN 113977039 A CN113977039 A CN 113977039A
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K9/00—Arc welding or cutting
- B23K9/095—Monitoring or automatic control of welding parameters
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- B—PERFORMING OPERATIONS; TRANSPORTING
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- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K9/00—Arc welding or cutting
- B23K9/16—Arc welding or cutting making use of shielding gas
- B23K9/173—Arc welding or cutting making use of shielding gas and of a consumable electrode
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- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
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Abstract
The invention discloses a device for monitoring the transition of molten drops in pulse consumable electrode argon arc welding, which comprises: the arc sensor is used for monitoring arc changes in the welding process, converting optical signals into electric signals and transmitting the electric signals to the controller; the arc sensor fixing device is used for fixing the arc sensor on the welding gun in the welding process; and the controller judges the droplet transition frequency at the moment according to the electric signal transmitted by the arc sensor and judges the coincidence condition of the droplet transition frequency and the pulse period of the pulsed arc at the moment. The invention also discloses a control method for the molten drop transition of the pulse consumable electrode argon arc welding, which controls the welding current through fuzzy PID control, thereby leading the pulse consumable electrode argon arc welding to always keep a good molten drop transition form of one pulse and one drop, realizing the closed-loop control of the molten drop transition frequency, solving the defects of splashing, finger-shaped molten depth and the like caused by improper molten drop transition frequency in the welding process, improving the stability of the welding process and obtaining a welding line with better welding quality.
Description
Technical Field
The invention relates to the technical field of welding of metal materials, in particular to a device for monitoring molten drop transition in pulsed consumable electrode argon arc welding and a control method.
Background
Due to the current increase in the driving range of electric vehicles, the weight reduction of automobiles has become the focus of the research direction of automobiles. Aluminum alloys are increasingly being used in automobiles because of their low density and high specific strength. The pulse consumable electrode argon arc welding and the double-pulse consumable electrode argon arc welding can effectively weld the aluminum thin plate and are widely applied to the welding process of the automobile body.
Pulsed gas metal arc welding is an arc welding method that protects metal droplets, weld pools and high temperature metal in the weld zone by using a consumable electrode with an external gas as an arc medium. When in droplet injection transition, the welding wire has high melting coefficient, low droplet temperature, little welding smoke and basically no splash, but the droplet injection transition current interval is too narrow, so the droplet injection transition form is difficult to use reliably. Researches find that the pulsed consumable electrode argon arc welding (pulse MIG/MAG welding for short) is a very suitable welding method.
There are three forms of pulsed MIG/MAG weld droplet transitions: (1) each pulse transitions between one large drop and multiple small drops. (2) Each pulse transitions through one large drop. (3) Several pulses transition into one large droplet. In the first form, the first droplet is a larger droplet of similar diameter to the wire, followed by a series of droplets. The shapes of these droplets and the conical arc are likely to generate spatters and smoke, and the formation of the weld with the finger-like penetration is not ideal. In the third form, the molten drop transition mode is similar to that of thick drop transition, the welding process is unstable, the molten drop transition is irregular, the weld joint is irregular in formation, and the method is not suitable for use. The second transition form is a pulse transition and a molten drop, has a drop injection transition mode, and can realize stable drop injection transition from the jet flow transition critical current to dozens of amperes. In summary, a pulse transition and a droplet are the best forms of droplet transitions. Therefore, the manner and frequency of droplet transitions during welding can have a significant impact on the quality of the welded joint.
The molten drop transition process of the pulse consumable electrode argon arc welding is quite complex, on one hand, the pulse parameters are more, and all the parameters must be matched with each other. On the other hand, other welding parameters such as wire feed speed, arc voltage, shielding gas composition, wire stick out, etc. are relatively independent and must be adjusted over a significant amount of time to ensure that the welding process is stable. Therefore, the control of the molten drop transition process by the open-loop control is difficult to ensure that the dropping form of the molten drop is shot drop transition, and each parameter can bring adverse effect on the welding quality as long as the parameter is slightly changed. In order to ensure the stability of the pulse consumable electrode argon arc welding process and improve the welding quality, the molten drop transition process must be controlled by adopting closed-loop control. At the same time, however, the welding process also needs to be monitored, so that the welding process can be adjusted in real time.
Disclosure of Invention
The invention aims to design and develop a molten drop transition monitoring device for pulsed consumable electrode argon arc welding, wherein an arc light sensor is fixed on a welding gun through a fixing device, the molten drop transition frequency is monitored at a short distance, and the monitoring accuracy is improved while the molten drop transition frequency is stable and reliable.
The invention also designs and develops a control method for the molten drop transition in the pulse consumable electrode argon arc welding, adopts a fuzzy PID control algorithm to carry out closed-loop control on the whole welding process, and can achieve the purpose of changing the molten drop transition period through the change of pulse current, shorten the regulation time, and contribute to improving the dynamic performance of a molten drop transition frequency controller and enhancing the stability of a system.
The technical scheme provided by the invention is as follows:
a pulse consumable electrode argon arc welding molten drop transition monitoring device comprises:
the clamping ring is of an open ring structure and is sleeved on the welding gun; and
the two clamping pieces are respectively arranged at two ends of the opening of the clamping ring;
fastening means passing through said two clamping tabs for selectively closing the opening of said clamping ring;
one end of the first positioning pipe is fixedly connected with the clamping ring;
the second positioning tube is of an L-shaped structure, one end of a long edge is movably arranged in the first positioning tube, and the long edge and the first positioning tube are selectively and relatively fixed;
the fixing frame is arranged on the short edge of the second positioning pipe and can be bent at any angle and fixed;
and the arc sensor is arranged on the fixing frame, is vertical to the welding gun and is arranged at the same height as the arc.
Preferably, the arc sensor includes:
an arc signal receiver that receives an arc signal from the welding torch;
the arc signal processor is connected with the arc signal receiver and is used for converting the arc signals into electric signals;
and the arc signal emitting device is connected with the arc signal processor and is used for transmitting the electrical signals.
Preferably, the method further comprises the following steps:
and the controller is electrically connected with the arc signal emitting device and is used for controlling the welding equipment.
Preferably, the method further comprises the following steps:
a plurality of first through holes which are arranged on the first positioning pipe at intervals;
a plurality of second through holes spaced apart on the long side;
and the positioning pin selectively penetrates through the first through hole and the second through hole and is used for fixing the relative positions of the first positioning pipe and the second positioning pipe.
A control method for the transition of molten drops in pulse consumable electrode argon arc welding is used, and the monitoring device for the transition of molten drops in pulse consumable electrode argon arc welding comprises the following steps:
step one, collecting arc light signals;
and step two, obtaining a molten drop transition period, comparing the molten drop transition period with a pulse period of pulse current, if the molten drop transition period is not equal to the pulse period of the pulse current, establishing a molten drop transition control model, adjusting the welding current, and stopping adjustment until the molten drop transition period is equal to the pulse period of the pulse current, so as to realize a one-pulse-one-drop molten drop transition form.
Preferably, the droplet transfer period is:
when the arc signal reaches the maximum, the instantaneous drop is the beginning of a droplet transition period, and then the arc signal goes from low to high until the arc signal is instantaneously dropped again to the end of the droplet transition period.
Preferably, the droplet transition control model is a PID fuzzy control model, and specifically includes:
inputting the difference e between the droplet transition period and the pulse period of the pulse current and the difference change rate ec into a PID fuzzy control model;
adjusting proportional gain, integral gain and differential gain in a PID fuzzy controller;
the PID fuzzy control model outputs a proportional gain correction quantity, an integral gain correction quantity and a differential gain correction quantity;
and adjusting the difference between the droplet transition period and the pulse period of the pulse current according to the proportional gain correction amount, the integral gain correction amount and the differential gain correction amount.
Preferably, the difference between the actual welding peak current and the ideal welding peak current is 0 to 50A, the current change rate is 10A/s, and the correction amount of the proportional gain, the correction amount of the integral gain, and the correction amount of the differential gain satisfy:
KP＝ΔKP+{e,ec}p；
KI＝ΔKI+{e,ec}i；
KD＝ΔKD+{e,ec}d；
in the formula, KPTo proportional gain, KITo integrate the gain, KDFor differential gain, Δ KPCorrection for proportional gain, { e, ec }pFor a matrix fuzzy model of proportional gain, Δ KIIs the correction of integral gain, { e, ec }iFor a matrix fuzzy model of integral gain, Δ KDIs a differential gainCorrection amount of (1), (e, ec) }dA matrix fuzzy model of the differential gain.
Preferably, the ambiguity range of the difference e between the droplet transition period and the pulse period of the pulse current is (-1,1), and the ambiguity range of the difference change rate ec is (-1, 1);
the fuzzy domain of the proportional gain correction is (-1,1), the fuzzy domain of the integral gain correction is (-1,1), and the fuzzy domain of the differential gain correction is (-1, 1).
Preferably, the difference e and the difference change rate ec between the droplet transition period and the pulse period of the pulse current in the PID fuzzy control model are all 7 levels, the fuzzy set is { NB, NM, NS, ZO, PS, PM, PB }, and the correction amount Δ K of the proportional gain in the PID fuzzy control model isPCorrection amount of integral gain Δ KIAnd correction amount of differential gain Δ KDDividing the fuzzy set into 7 levels, wherein the fuzzy set is { NB, NM, NS, ZO, PS, PM, PB };
in the formula, NB is negative and large, NM is negative and medium, NS is negative and small, ZO is zero, PS is positive and small, PM is middle, and PB is positive and large.
The invention has the following beneficial effects:
(1) compared with the device for monitoring the metal molten drop transition process by adopting a high-speed camera, the device for monitoring the molten drop transition process by adopting the arc light sensor is designed and developed, so that the cost for monitoring the molten drop transition frequency is greatly reduced, and the device can be interconnected with a control end of welding equipment.
(2) The invention discloses a device for monitoring the molten drop transition of the pulse consumable electrode argon arc welding, which is designed and developed by the invention.
(3) The fuzzy PID control method can reduce the overshoot of the system, shorten the regulation time, contribute to improving the dynamic performance of a molten drop transition frequency controller and enhancing the stability of the system, and form a one-pulse-one-drop molten drop transition.
Drawings
FIG. 1 is a schematic structural diagram of a molten drop transition monitoring device for pulsed consumable electrode argon arc welding according to the present invention.
FIG. 2 is a schematic structural diagram of the assembly of the pulsed consumable electrode argon arc welding molten drop transition monitoring device of the present invention.
FIG. 3 is a flow chart of a droplet transfer control method for pulsed consumable electrode argon arc welding according to the present invention.
FIG. 4 is a schematic diagram of the change of the arc signal during the droplet transfer cycle of the present invention.
FIG. 5 is a schematic diagram of a fuzzy control rule curve of the correction amount of proportional gain according to the present invention.
Fig. 6 is a schematic diagram of a fuzzy control rule curved surface of the correction amount of the integral gain according to the present invention.
Fig. 7 is a schematic diagram of a fuzzy control rule curve of the correction amount of the differential gain according to the present invention.
FIG. 8 is a schematic diagram of a transition current interval of pulsed consumable electrode argon arc welding droplets according to the present invention.
Detailed Description
The present invention is described in further detail below in order to enable those skilled in the art to practice the invention with reference to the description.
As shown in fig. 1, the present invention provides a molten drop transition monitoring device for pulsed gas metal argon arc welding, which specifically includes: the arc sensor 170 is used for monitoring arc changes in the welding process, converting optical signals into electric signals and transmitting the electric signals to the controller; the arc sensor fixing device is used for fixing the arc sensor in the welding process; and a controller (not shown) for determining the droplet transition frequency based on the electrical signal from the arc sensor, and determining the coincidence of the droplet transition frequency and the pulse period of the pulsed arc.
The arc sensor 170 includes: the arc signal receiver, the arc signal processor and the arc signal transmitting device, wherein in the welding process, the welding gun sends out an arc signal which is received by the arc signal receiver; in the receiving process, the specific light intensity is not required to be obtained, and only the time period of light intensity change is required to be obtained, so that the workload of the sensor can be greatly reduced; when the arc signal reaches the maximum and then instantaneously decreases, the droplet transition occurs, the signal can be considered to represent the beginning of a droplet transition period, and when the arc signal changes from weak to strong in the droplet transition beginning period, the arc signal decreases again until the arc signal reaches the maximum, and the time is a period of the droplet transition. The arc signal receiver receives arc signal change by using the sensing element and transmits an arc signal change signal to the arc signal processor; the arc signal processor converts the received arc signal change into the change of an electric signal by using the conversion original piece and transmits the electric signal to the arc signal emitting device; the arc light signal emission device transmits the electric signal to a wireless receiving module of the molten drop transition controller, and the molten drop transition controller processes the collected electric signal.
Utilize pulse MIG welding equipment to weld the parent metal, in the welding process, the form of molten drop transition is difficult to monitor, compare in other sensors, because the light that electric arc sent, it is hot, sound, the interference of splashing etc., sensor commonly used can receive certain influence, adopt arc light sensor 170 to monitor the arc light in the molten drop transition process, because the existence of molten drop, when taking place the molten drop transition, the change of arc light is comparatively obvious, consequently, adopt arc light sensor record molten drop transition's frequency, the signal of this detection is the signal that needs control promptly, be fit for carrying out the control of molten drop transition, furthermore, also there is not very high requirement to arc light sensor 170's arrangement position, can fix on welder, also can fix near the welding bead, can monitor welding process molten drop action can, arc light sensor 170 size designatable is less, save space.
The arc light sensor 170 is adopted to monitor the molten drop transition process in the welding process, the molten drop transition signal is transmitted to the controller, the matching condition of the molten drop transition frequency and the parameters of the welding power supply is detected, the molten drop transition frequency detected by the arc light sensor 170 is formed into a signal which can be compared with an input instruction based on the feedback control principle, the controlled quantity is compared with the input instruction at any time to form an error, and the error is used for controlling the servo mechanism to operate in the direction of eliminating the error and continuously correcting the input instruction.
The operating principle of the arc sensor 170 is as follows: in the formation process of molten drop, molten drop luminance is a process that increases gradually, and when the molten drop necking down was broken by the stretch-breaking, the molten drop fell from the welding wire end and takes place the molten drop transition, and arc light detection signal reduces suddenly, and the separation from and the transition of this concave reaction molten drop that can be accurate can regard as the characteristic signal of molten drop transition, and this characteristic signal-to-noise ratio is high, reliable and stable.
This embodiment arc sensor fixing device specifically includes: the welding device comprises two clamping pieces 110, a fastening device, a positioning pin 130, a first positioning pipe 140, a second positioning pipe 150, a fixing frame 160 and a clamping ring 180, wherein the clamping ring 180 is of an open ring structure and is sleeved on a welding gun, and the design size of the clamping ring 180 is the same as that of the welding gun; the two clamping pieces 110 are respectively arranged at two ends of the opening of the clamping circular ring 180 and can clamp the clamping circular ring 180; fastening means pass through said two clamping tabs 110 for selectively closing said clamping ring 180 opening; one end of the first positioning tube 140 is fixedly connected with the clamping ring 180; the second positioning tube 150 is an L-shaped structure, one end of the long side is movably disposed in the first positioning tube 140, and the long side and the first positioning tube 140 are selectively and relatively fixed; a fixing frame 160 is arranged on the short side of the second positioning tube 150, the fixing frame 160 can be bent and fixed at any angle, the arc sensor 170 is arranged on the fixing frame 160, and the arc sensor 170 is perpendicular to the welding gun and is arranged at the same height as the arc; the first positioning tube 140 is provided with a plurality of first through holes at intervals, the long side of the second positioning tube 150 is provided with a plurality of second through holes with the same number as the first through holes at intervals, and the positioning pin 130 can selectively penetrate through the first through holes and the second through holes to fix the relative positions of the first positioning tube 140 and the second positioning tube 150.
In this embodiment, the number of the first through holes and the number of the second through holes are both 5, the number of the through holes is not limited to 5, and the number of the through holes can be arbitrarily selected as required; the fastening device includes: a clamping nut 120 and a clamping bolt 190, wherein the clamping bolt 190 penetrates through the two clamping sheets 110 and is fixed by the clamping nut 120.
When the arc sensor is installed, the clamping ring 180 can be slightly opened, and then the clamping ring is sleeved on the welding gun and then clamped by the clamping bolt 190 and the clamping nut 120, so that the arc sensor 170 is integrally fixed with the welding gun; in the welding process, the matching positions of the first through hole and the second through hole between the first positioning tube 140 and the second positioning tube 150 are selected according to requirements, so that the distance between the arc sensor and a welding wire, namely the molten drop transition position, is selected according to requirements; selecting the position of the positioning pin 130 according to actual welding requirements; the positioning pin 130 and the first positioning tube 140 and the second positioning tube 150 are in interference fit to obtain a more stable fixing effect of the arc sensor 170.
As shown in fig. 2, the arc sensor 170 is generally set to be equal to the arc height in the welding process, and the monitoring direction of the arc sensor 170 is directly perpendicular to the welding gun, so that the welding process is not monitored by adopting the mirror reflection principle, and the arc light can be better monitored, thereby controlling the droplet transfer process.
Compared with the device for monitoring the metal molten drop transition process by adopting a high-speed camera, the device for monitoring the molten drop transition frequency of the pulsed consumable electrode argon arc welding is designed and developed, the arc light sensor is adopted to monitor the arc light in the molten drop transition process, the cost for monitoring the molten drop transition frequency can be greatly reduced, the device can be interconnected with the control end of welding equipment, the arc light sensor is fixed on a welding gun through a fixing device, the molten drop transition frequency can be monitored at a short distance, the monitoring accuracy is improved while stability and reliability are realized, the size of the arc light sensor can be designed to be smaller, and the space is saved.
As shown in fig. 3, the present invention further provides a droplet transition control method for pulsed gas metal arc welding, wherein the droplet transition monitoring device for pulsed gas metal arc welding mainly changes welding parameters by changing welding current process parameters.
The molten drop form of the pulse consumable electrode argon arc welding is mostly one drop per pulse, one drop per pulse and one drop per pulse, and the key point is to obtain the molten drop transition form of one drop per pulse, namely the control of welding process parameters, particularly the control of welding current.
And in the welding process, the molten drop transition time is monitored and compared with the welding pulse period, so that the molten drop transition mode in the welding process is judged.
If the welding process is one pulse and multiple droplets, the droplet transition frequency is proved to be too fast, the heat input is proved to be too large, at the moment, the welding control system inputs an instruction to the welding power supply, the welding current is reduced to a lower current, and the droplet transition frequency is continuously observed until the stable one pulse one droplet transition is realized.
If the welding process is multi-pulse one-drop, the droplet transition frequency is proved to be too slow, the heat input is small, at the moment, the welding control system inputs an instruction to a welding power supply, the welding current is gradually increased, and the droplet transition frequency is continuously observed until stable one-pulse one-drop droplet transition is realized.
In the control process, on the basis of obtaining the droplet frequency, if the welding current is only adjusted in a single direction, the efficiency is not very high, and if the difference between the initial welding parameter and the optimal one-pulse-droplet parameter is large, the time for searching the optimal parameter is long, and the satisfactory welding quality cannot be obtained.
The invention relates to a control method for molten drop transition in pulsed consumable electrode argon arc welding, which comprises the following steps:
monitoring arc light change through an arc light sensor, collecting an arc light change signal of a molten drop, sending the signal to a wireless receiving module, and outputting the signal to a controller after the signal is processed by an A/D data collecting and processing module;
step two, obtaining a molten drop transition period, comparing the molten drop transition period with a pulse period of pulse current, if the molten drop transition period is not equal to the pulse period of the pulse current, and the molten drop transition state does not reach an ideal state, establishing a molten drop transition control model, and adjusting the welding current;
when the droplet transition period is smaller than the pulse period of the pulse current, increasing the welding pulse current;
when the droplet transition period is larger than the pulse period of the pulse current, reducing the welding pulse current;
and stopping adjustment until the droplet transition period is equal to the pulse period of the pulse current, so as to realize a one-pulse-droplet transition form.
Wherein, at the molten drop formation to the biggest, the necking down is broken to the in-process that the welding wire end drops, and what arc signal experienced is the process that increases gradually again earlier, and after the arc signal reached the highest, be the beginning of a molten drop transition period when reducing in the twinkling of an eye, this arc signal from the minimum can be regarded as the end of a molten drop transition period of welding process to the process that reduces again of biggest.
The traditional PID is generally established on the basis of an accurate model and has a good adjusting effect on a linear system, however, in a system with larger interference or a nonlinear system, the traditional PID control algorithm is always subjected to overshoot or has larger static error with an expected level, and compared with the traditional PID controller, the fuzzy controller has better robustness.
Therefore, the droplet transition control model is a PID fuzzy control model, and a difference value e between the droplet transition cycle and the target droplet transition cycle and a change rate ec of the difference value are obtained according to the real-time monitored droplet transition cycle and the target droplet transition cycle.
Setting the initial proportional coefficient, the integral coefficient and the differential coefficient of the parameters of the PID control algorithm according to the difference e between the two, the change rate ec of the difference and the PID control algorithm, and KPTo proportional gain, KITo integrate the gain, KDIs the differential gain.
According to the difference e between the droplet transition period and the pulse period and the change rate ec of the difference, performing fuzzy calculation by using the difference e and the change rate ec as fuzzy input quantities, performing reasoning and decision by using a fuzzy rule, performing fuzzy resolution on fuzzy parameters, and inputting the proportional, differential and integral coefficients of a PID controller;
the output quantity of PID control (regulation) is set as u (t), the difference value between the droplet transition period and the pulse period is set as input quantity e (t), and the relationship between the input quantity and the pulse period is as follows:
in the formula, KPTo proportional gain, KITo integrate the gain, KDIs the differential gain; in order to obtain a satisfactory control effect, the three parameters need to be adjusted in real time according to the system state; through a large amount of operation experience, the three coefficients have a nonlinear relation with the deviation amount e (t) and the deviation change rate de (t)/dt of the input controller; these relationships cannot be described by clear mathematical expressions, but can be expressed in fuzzy language:
when | e (t) | is larger, to increase the response speed of the system, a larger K is selectedPThus, the time constant and the damping coefficient of the system can be reduced; certainly not too large, otherwise the system would be unstable; to avoid out-of-range control effects that may be caused by the system at start-up, a smaller K should be takenDTo speed up system response; to avoid major overshoot, the integral can be removed, and K is takenI＝0；
When | e (t) | is at medium size, it should take smaller KPMaking the corresponding overshoot of the system slightly smaller; at this time KDThe value of (A) is more critical to the system, and K is the response speed of the systemDThe value of (A) is proper; at this time, a point K can be addedIBut not too large;
when | e (t) | is smaller, a larger K may be used to obtain a good steady-state performance of the systemPAnd KI(ii) a To avoid oscillation of the system at the equilibrium point, KDThe value of (A) should be appropriate;
in the control system, the maximum difference value between the actual welding peak current and the peak current in the one-pulse-one-drop molten drop transition form (ideal welding peak current) is set to be 50A, the current change rate is set to be 10A/s, and three parameters K are obtained based on the input variablesP，KI，KDThe relationship between;
KP＝ΔKP+{e,ec}p；
KI＝ΔKI+{e,ec}i；
KD＝ΔKD+{e,ec}d；
in the formula, KPTo proportional gain, KITo integrate the gain, KDFor differential gain, Δ KPCorrection for proportional gain, { e, ec }pFor a matrix fuzzy model of proportional gain, Δ KIIs the correction of integral gain, { e, ec }iFor a matrix fuzzy model of integral gain, Δ KDCorrection for differential gain, { e, ec }dA matrix fuzzy model of the differential gain.
And setting argument ranges of the difference value e and the difference value change rate ec of the droplet transition period and the pulse period of the pulse current to be (-1,1), an argument range of the correction quantity of the proportional gain to be (-1,1), an argument range of the correction quantity of the integral gain to be (-1,1), and an argument range of the correction quantity of the differential gain to be (-1, 1).
Determining fuzzy subsets of input variables, wherein the input variables are difference values e and difference value change rates ec of a droplet transition period and a pulse period of pulse current respectively, and the two input variables respectively select 7 fuzzy sets as language values and are marked as { NB, NM, NS, ZO, PS, PM and PB };
determining a fuzzy subset of output variables, the output variables being proportional gain corrections Δ K of PID parametersPCorrection amount of integral gain Δ KIAnd correction amount of differential gain Δ KDThe method comprises the following steps of selecting 7 fuzzy sets as language values of the three output variables, and respectively recording the fuzzy sets as { NB, NM, NS, ZO, PS, PM and PB };
in the formula, NB is negative and large, NM is negative and medium, NS is negative and small, ZO is zero, PS is positive and small, PM is middle, and PB is positive and large.
Generating a correction amount Δ K for a PID parameter from fuzzy subsets of input and output variablesP、ΔKIAnd Δ KDThe fuzzy rule control table of (1):
TABLE- Δ KPFuzzy rule ofWatch (A)
TABLE II. DELTA.KIFuzzy rule table of
TABLE III Δ KDFuzzy rule table of
According to Δ K, as shown in FIG. 5, FIG. 6, and FIG. 7P、△KI、△KDThe fuzzy rule table establishes a fuzzy rule control curved surface.
And comparing a molten drop transition period formed according to the actual pulse period after the pulse current is adjusted with the pulse period, and quickly correcting the difference value between the molten drop transition period and the pulse period according to a fuzzy PID control algorithm so as to achieve optimal control.
The fuzzy control process can be summarized as follows:
(1) and calculating the input variable of the selected system according to the output value of the system obtained by sampling.
(2) The precise value of the input variable is changed to a fuzzy amount.
(3) The output control quantity (fuzzy quantity) is calculated according to the input variable (fuzzy quantity) and the fuzzy control rule and the fuzzy reasoning synthesis rule.
(4) An accurate output control amount is calculated from the control amount (blur amount) obtained as described above, and acts on an actuator:
when the droplet transition period time is longer than the pulse current pulse period, the fuzzy PID controller sends out a pulse current increasing instruction to control the pulse current to increase.
When the droplet transition period time is shorter than the pulse current pulse period, the fuzzy PID controller sends out a pulse current reduction instruction to control the pulse current to be reduced.
The purpose of changing the droplet transition period can be achieved through the change of the pulse current.
Fig. 8 shows the relationship between the droplet transition frequency and the pulse duration, in which the white circle portion is a one-pulse-one-droplet transition section, the lower portion of the lower curve is a multi-pulse-one-droplet section, and the upper portion of the upper curve is a one-pulse-multi-droplet section.
For the defects of the traditional PID control method in controlling the change of the molten drop transition period, the fuzzy control PID method is adopted to control the molten drop transition, so that the stable control of the molten drop transition can be realized, and the defects of splashing, smoke dust, finger-shaped fusion depth and the like caused by improper molten drop transition frequency in the welding process can be effectively overcome, so that the stability of the welding process is improved, and a welding seam with good welding quality can be obtained.
While embodiments of the invention have been described above, it is not limited to the applications set forth in the description and the embodiments, which are fully applicable to various fields of endeavor for which the invention may be embodied with additional modifications as would be readily apparent to those skilled in the art, and the invention is therefore not limited to the details given herein and to the embodiments shown and described without departing from the generic concept as defined by the claims and their equivalents.
Claims (10)
1. The utility model provides a pulse consumable electrode argon arc welds molten drop transition monitoring devices which characterized in that includes:
the clamping ring is of an open ring structure and is sleeved on the welding gun; and
the two clamping pieces are respectively arranged at two ends of the opening of the clamping ring;
fastening means passing through said two clamping tabs for selectively closing the opening of said clamping ring;
one end of the first positioning pipe is fixedly connected with the clamping ring;
the second positioning tube is of an L-shaped structure, one end of a long edge is movably arranged in the first positioning tube, and the long edge and the first positioning tube are selectively and relatively fixed;
the fixing frame is arranged on the short edge of the second positioning pipe and can be bent at any angle and fixed;
and the arc sensor is arranged on the fixing frame, is vertical to the welding gun and is arranged at the same height as the arc.
2. The apparatus for monitoring the droplet transition in pulsed gas arc welding according to claim 1, wherein the arc light sensor comprises:
an arc signal receiver that receives an arc signal from the welding torch;
the arc signal processor is connected with the arc signal receiver and is used for converting the arc signals into electric signals;
and the arc signal emitting device is connected with the arc signal processor and is used for transmitting the electrical signals.
3. The apparatus for monitoring the droplet transition in pulsed gas arc welding according to claim 2, further comprising:
and the controller is electrically connected with the arc signal emitting device and is used for controlling the welding equipment.
4. The apparatus for monitoring the droplet transition in pulsed gas arc welding according to claim 3, further comprising:
a plurality of first through holes which are arranged on the first positioning pipe at intervals;
a plurality of second through holes spaced apart on the long side;
and the positioning pin selectively penetrates through the first through hole and the second through hole and is used for fixing the relative positions of the first positioning pipe and the second positioning pipe.
5. A control method for molten drop transition in pulsed consumable electrode argon arc welding, which uses the monitoring device for molten drop transition in pulsed consumable electrode argon arc welding according to claims 1-4, and is characterized by comprising the following steps:
step one, collecting arc light signals;
and step two, obtaining a molten drop transition period, comparing the molten drop transition period with a pulse period of pulse current, if the molten drop transition period is not equal to the pulse period of the pulse current, establishing a molten drop transition control model, adjusting the welding current, and stopping adjustment until the molten drop transition period is equal to the pulse period of the pulse current, so as to realize a one-pulse-one-drop molten drop transition form.
6. The method for controlling droplet transfer in pulsed gas arc welding according to claim 5, wherein the droplet transfer period is as follows:
when the arc signal reaches the maximum, the instantaneous drop is the beginning of a droplet transition period, and then the arc signal goes from low to high until the arc signal is instantaneously dropped again to the end of the droplet transition period.
7. The method for controlling molten drop transition in pulsed gas arc welding according to claim 6, wherein the molten drop transition control model is a PID fuzzy control model, and specifically comprises:
inputting the difference e between the droplet transition period and the pulse period of the pulse current and the difference change rate ec into a PID fuzzy control model;
adjusting proportional gain, integral gain and differential gain in a PID fuzzy controller;
the PID fuzzy control model outputs a proportional gain correction quantity, an integral gain correction quantity and a differential gain correction quantity;
and adjusting the difference between the droplet transition period and the pulse period of the pulse current according to the proportional gain correction amount, the integral gain correction amount and the differential gain correction amount.
8. The method according to claim 7, wherein the difference between the actual welding peak current and the ideal welding peak current is 0-50A, the current change rate is 10A/s, and the correction amount of the proportional gain, the correction amount of the integral gain and the correction amount of the differential gain satisfy:
KP＝ΔKP+{e,ec}p；
KI＝ΔKI+{e,ec}i；
KD＝ΔKD+{e,ec}d；
in the formula, KPTo proportional gain, KITo integrate the gain, KDFor differential gain, Δ KPCorrection for proportional gain, { e, ec }pFor a matrix fuzzy model of proportional gain, Δ KIIs the correction of integral gain, { e, ec }iFor a matrix fuzzy model of integral gain, Δ KDCorrection for differential gain, { e, ec }dA matrix fuzzy model of the differential gain.
9. The method for controlling droplet transfer in pulsed gas arc welding according to claim 8, wherein the ambiguity range of the difference e between the droplet transfer period and the pulse period of the pulse current is (-1,1), and the ambiguity range of the difference change rate ec is (-1, 1);
the fuzzy domain of the proportional gain correction is (-1,1), the fuzzy domain of the integral gain correction is (-1,1), and the fuzzy domain of the differential gain correction is (-1, 1).
10. The method according to claim 9, wherein the difference e and the difference change rate ec between the droplet transfer period and the pulse period of the pulse current in the PID fuzzy control model are equally 7 levels, the fuzzy set is { NB, NM, NS, ZO, PS, PM, PB }, and the correction amount Δ K of the proportional gain in the PID fuzzy control model isPCorrection amount of integral gain Δ KIAnd correction amount of differential gain Δ KDDividing the fuzzy set into 7 levels, wherein the fuzzy set is { NB, NM, NS, ZO, PS, PM, PB };
in the formula, NB is negative and large, NM is negative and medium, NS is negative and small, ZO is zero, PS is positive and small, PM is middle, and PB is positive and large.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115026382A (en) * | 2022-05-26 | 2022-09-09 | 南昌大学 | Welding arc light detection sensor |
| CN115383260A (en) * | 2022-10-11 | 2022-11-25 | 湘潭大学 | GTAW process molten drop transition frequency control method based on arc sensing |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1071109A (en) * | 1991-09-27 | 1993-04-21 | 哈尔滨工业大学 | Utilize arc light to detect the method for droplet transfer |
| JPH07290241A (en) * | 1994-04-25 | 1995-11-07 | Kobe Steel Ltd | Carbon dioxide pulse arc welding method |
| CN2389746Y (en) * | 1999-08-06 | 2000-08-02 | 李鹏九 | Arc sensor for detection of droplet transfer of arc welding |
| CN1291534A (en) * | 2000-10-27 | 2001-04-18 | 天津大学 | Pulse optical spectrum control method for protecting molten electrode drops by gas |
| CN1634676A (en) * | 2005-01-13 | 2005-07-06 | 上海交通大学 | Full-digital speed change control method for wire feeding for submerged arc welding |
| CN105290576A (en) * | 2015-09-29 | 2016-02-03 | 湘潭大学 | Real-time detecting method and device for surface topography of swing arc MAG welding molten pool |
| CN105892475A (en) * | 2016-05-04 | 2016-08-24 | 中国海洋大学 | Underwater glider attitude control algorithm based on fuzzy PID |
| CN209609292U (en) * | 2019-02-20 | 2019-11-12 | 广东农工商职业技术学院 | A kind of ornamental plant cuts out curing means |
| US20200070270A1 (en) * | 2018-08-31 | 2020-03-05 | Illinois Tool Works Inc. | Systems and methods for auto-tuning a gmaw welding process |
| CN112336944A (en) * | 2020-09-28 | 2021-02-09 | 辉瑞(山东)环境科技有限公司 | Remove lift integral type transfusion rod |
-
2021
- 2021-10-27 CN CN202111252951.4A patent/CN113977039B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1071109A (en) * | 1991-09-27 | 1993-04-21 | 哈尔滨工业大学 | Utilize arc light to detect the method for droplet transfer |
| JPH07290241A (en) * | 1994-04-25 | 1995-11-07 | Kobe Steel Ltd | Carbon dioxide pulse arc welding method |
| CN2389746Y (en) * | 1999-08-06 | 2000-08-02 | 李鹏九 | Arc sensor for detection of droplet transfer of arc welding |
| CN1291534A (en) * | 2000-10-27 | 2001-04-18 | 天津大学 | Pulse optical spectrum control method for protecting molten electrode drops by gas |
| CN1634676A (en) * | 2005-01-13 | 2005-07-06 | 上海交通大学 | Full-digital speed change control method for wire feeding for submerged arc welding |
| CN105290576A (en) * | 2015-09-29 | 2016-02-03 | 湘潭大学 | Real-time detecting method and device for surface topography of swing arc MAG welding molten pool |
| CN105892475A (en) * | 2016-05-04 | 2016-08-24 | 中国海洋大学 | Underwater glider attitude control algorithm based on fuzzy PID |
| US20200070270A1 (en) * | 2018-08-31 | 2020-03-05 | Illinois Tool Works Inc. | Systems and methods for auto-tuning a gmaw welding process |
| CN209609292U (en) * | 2019-02-20 | 2019-11-12 | 广东农工商职业技术学院 | A kind of ornamental plant cuts out curing means |
| CN112336944A (en) * | 2020-09-28 | 2021-02-09 | 辉瑞(山东)环境科技有限公司 | Remove lift integral type transfusion rod |
Non-Patent Citations (2)
| Title |
|---|
| 毕侠飞: "基于模糊-PID控制的PMIG弧焊逆变电源主控系统研究", 《中国优秀博硕士学位论文全文数据库(硕士)工程科技Ⅰ辑》 * |
| 赵举东: "脉冲MIG_MAG焊接熔滴过渡的自适应模糊控制", 《电子与自动化》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115026382A (en) * | 2022-05-26 | 2022-09-09 | 南昌大学 | Welding arc light detection sensor |
| CN115383260A (en) * | 2022-10-11 | 2022-11-25 | 湘潭大学 | GTAW process molten drop transition frequency control method based on arc sensing |
| CN115383260B (en) * | 2022-10-11 | 2024-05-07 | 湘潭大学 | GTAW process droplet transition frequency control method based on arc sensing |
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