Synchronous weld pool oscillation for monitoring and control

Andersen, Kristinn; Cook, Gerald; Barnett, R.J.; Strauss, Alvin M.

doi:10.1109/ias.1994.377691

Cited by 21 publications

(15 citation statements)

References 2 publications

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“…Andersen [7] developed a synchronous weld pool oscillation method for controlling the weld pool dimensions and state of penetration. The approach used to induce pool oscillations was to excite the weld pool with current pulses synchronized to the natural oscillations of the pool.…”

Section: Pool Oscillation Methodsmentioning

confidence: 99%

Real-Time Measurement of Three Dimensional Weld Pool Surface in GTAW

Zhang¹,

Liu²,

Zhang³

2012

Welding Processes

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Section: Pool Oscillation Methodsmentioning

confidence: 99%

Real-Time Measurement of Three Dimensional Weld Pool Surface in GTAW

Zhang¹,

Liu²,

Zhang³

2012

Welding Processes

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“…Step 1) Re-compute the grayscale range of the image as [1,255]. Compute the normalized histogram distribution P (x) of the image as…”

Section: Image Segmentationmentioning

confidence: 99%

“…j = arg max j∈ [1,255] Nj (20) where N i denotes the frequency of the grayscale i and N j denotes the maximum frequency which occurs at j in the interval [1, 255]. Step 2) Transform P (x) by the discrete Fourier transform (DFT)…”

Section: Image Segmentationmentioning

confidence: 99%

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Monitoring of GMAW Weld Pool From the Reflected Laser Lines for Real-Time Control

Wang

2014

IEEE Trans. Ind. Inf.

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Abstract-Controlling the welding process by monitoring the weld pool surface becomes more and more popular in robotic arc welding. In this paper, we propose a monitoring system to infer the P-gas metal arc welding (GMAW) weld pool geometry from the reflected laser lines, which are projected onto the specular weld pool and reflected onto a diffusive plane. The parallel straight lines are distorted according to the shape of the weld pool and thus contain the weld pool's shape information. Accurately computing the equations of the imaged laser lines in the world coordinate system is critical for the subsequent weld pool shape estimation. This paper focuses on accurately segmenting and identifying the reflected laser lines and novel image processing algorithms are proposed to fulfill this specific task. Experimental results verified the effectiveness of the proposed algorithms.Index Terms-Clustering, gas metal arc welding (GMAW), gas tungsten arc welding (GTAW), image processing, machine vision, monitoring, segmentation.

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“…When optical giving the power source characteristics whereby the pulsed means are used, changes in the strength of light reflected output was modulated according to these. from the surface of the oscillating molten pool are detected [3] and, when an arc voltmeter is used, changes in the arc length due to height variations in the liquid surface 2. Experimental methods immediately below the arc are detected [4][5][6][7].…”

Section: Introductionmentioning

confidence: 99%

Detection and amplification of the molten pool natural oscillation in consumable electrode arc welding

Matsui

Chiba

Yamazaki

2012

Welding International

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In the pulsed MAG welding with highly precise periodic drop transfer, welding current was analysed by fast Fourier transform (FFT). By this analysis, peculiar frequency of the molten pool was detected by resonance phenomena with the base plate vibration and it was confirmed that peculiar frequency falls according to growth of the molten pool. Furthermore, natural frequency was detected at the natural welding state that is without vibration of the base plate and confirmed by the resonance method with the base plate vibration. To amplify natural vibration of the molten pool, drop transfer pulse was modulated consisting of regular pulse peak current and higher pulse peak current. The higher pulse peak current makes a change in the arc pressure and the molten pool is pushed down in the period of higher pulse. Because short circuit is apt to occur at the time that the molten pool is at the top of the front side, so it is effective for amplifying the molten pool oscillation that higher pulse phase begins at this time instantaneously or somewhat later. According to this, higher peak was gained at peculiar frequency by FFT analysis. It means that amplifying of the molten pool oscillation was successful. Appropriate period of higher pulse for maintaining stable oscillation is from about 1/4 to 1/2 of the oscillation cycle.

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Synchronous weld pool oscillation for monitoring and control

Cited by 21 publications

References 2 publications

Real-Time Measurement of Three Dimensional Weld Pool Surface in GTAW

Real-Time Measurement of Three Dimensional Weld Pool Surface in GTAW

Monitoring of GMAW Weld Pool From the Reflected Laser Lines for Real-Time Control

Detection and amplification of the molten pool natural oscillation in consumable electrode arc welding

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