Automatic Arc Welding System Research Articles

Design of Control Kit for Arc Welding Process with Atomised Digital Controlled Welding System

This Research paper studies about the designing and simulation aspects of automatic arc welding system using digital control with the help of Proteus Simulation software. The welding sequence considered for the study consists of five intervals they are Standby, Squeeze, Weld, Hold, and Release intervals. A separate stepping interval circuit with a decoder to step the intervals from one to another is designed and analysis is done using a decoding technique. The designed stepping circuit ensures the correct order of the five intervals of the welding system, also a separate stepping of heat-cool sub intervals of weld interval is also designed with a user defined preset time counter circuit so that welding interval can be timed based on the user defined priority and can also be stepped between the two heat and cool sub intervals based on the total time assigned by the user. The digital automatic control system is developed to accurately control the arc welding system for welding of two given metal pieces. This report concerns automatic welding system with digital control and is directed to the improvement of certain drive and guide means for a relatively freely carried welding of wheel rim and wheel spider for continuous welding of a part resting on a freely rotatable table. The drive and guide means are carried on the welding head and impart drive to the part while maintaining the welding head properly positioned relative to the part. The system presented is a slightly simplified version of a real automobile wheel-welding system. Although system operation is explained in terms of wheel welding, the design of the system has much in common with other welding operations utilizing the basic industrial automatic welding sequence of Squeeze, Weld, Hold, Release, and Standby with digital control.

A Novel Method to Improve Weld Uniformity by Automatic Control of Current Intensity

This study aims to develop an automatic arc welding system capable of welding irregular and moving joints which are difficult to weld manually. The motivation of this research comes from the need to produce uniforms weldings on regular and irregular surfaces by automatic means. The system consists of a personal computer equipped with A/D interface card connected to an electric current sensor and two electric motors controlled via electronic circuits. A control program receives the electric current measurements and makes the necessary calculations for the correct vertical motion of the welding electrode. A modified PID controller was used to control the process dynamics. An X-Y mechanism with two electric motors was developed to control the motion of the electrode as well as the work piece. A comparison was made between two welded specimens; one was welded by traditional manual method and, the second by using automatic control mechanism. The weld distribution through the welded joints was compared. Different irregular joints were also compared for the manual and automatic control welding methods. It was found that the control system works with an accuracy of ±28 µm for a 1.01 mm weld thickness of a flat weld by controlling the current at 60 A within a standard deviation of ±1.45 A. As a result welds with uniform thickness were obtained. The uniform heating further contributes to a uniform microstructure in the weld area. The implications of this research will be enhanced automation of the welding process in industry, with improved control over its uniformity, especially while welding around circular objects and during vibrating or unstable conditions.

Development of an automatic arc welding system using an adaptive sliding mode control

This paper develops an automatic welding control scheme for alternating current shielded metal arc welding (SMAW) system. A mathematical model of the welding control system is derived and the system parameters identified. An adaptive sliding mode controller is designed to estimate the bound of the system uncertainties and to modulate the electrode feed rate in such a way that the desired arc length and arc current are maintained as the electrode melts during the welding process. The proposed control method is suitable for any consumed electrode welding technique. The simulation and experimental results show that the automatic welding control system successfully maintains the magnitude of the arc current at the desired value and preserves the arc stability, thereby obtaining an enhanced SMAW control system performance.

Development of an automatic arc welding system using a variable structure model reference scheme

This paper presents an automatic welding control system for the alternating current shield metal arc welding process. A nominal nonlinear mathematical model containing uncertainties such as dead-zone, welding control system saturation, and the identified system parameters is derived. A novel variable structure model reference control scheme is designed to modulate the rate of the electrode feed mechanism, thereby regulating the arc current. The developed controller assures the global reaching condition of the sliding mode of the controlled welding system. In the sliding mode, the electric current error between the plant and the model asymptotically approaches zero. Moreover, the welding system remains insensitive to uncertainties and disturbance as the systems with friction. The simulation and experimental results confirm that the automatic welding control system, based on the proposed model-following variable structure controller, successfully maintains the magnitude of the arc current at the desired value and preserves the stability of the arc length, thereby ensuring excellent welding performance.

Adaptive fuzzy sliding mode control for an automatic arc welding system

Adaptive fuzzy sliding mode control for an automatic arc welding system

Tuning PID control of an automatic arc welding system using a SMAW process

A new method to tune the gains of the proportional integral derivative (PID) controller for alternating current shield metal arc welding (SMAW) of automatic arc welding system using a SMAW process is presented in this paper. This method used the genetic algorithm (GA) approach to optimize the gains of the PID auto-tuner and considerably modulated the rate of an electrode feed mechanism that regulates arc current. The proposed controller was verified by simulation and experiments of the transient response in the automatic arc welding system. Finally, the performance indices of the proposed controller are compared with that based on Ziegler–Nichols tuning rules.

Adaptive fuzzy sliding mode control for an automatic arc welding system

This paper describes an automatic welding control system developed for alternating current shielded metal arc welding (SMAW). This method could replace manual operations which require a well-trained technician. We have derived a mathematical model of the welding control system and identified the system’s parameters. The sliding surface is used as the input variable to reduce the number of fuzzy reasoning rules, in comparison with the conventional two-dimensional fuzzy logic control (FLC) algorithm. An adaptive fuzzy sliding mode controller (AFSMC) consists of an equivalent control part and a hitting control part. An adaptive law derived from a Lyapunov function is used to obtain the FLC’s parameters, and is applied to approximate the equivalent control part of the sliding mode control (SMC), so that the system states can be forced to zero. By using three-rules FLC, the control part that satisfies the hitting conditions of the SMC can force the system’s states to reach and remain on the sliding surface. Therefore, the stability of the AFSMC can be guaranteed and can be used to modulate the rate of the electrode feeding mechanism that regulates the arc current of the SMAW. The simulation and the experimental results both show that this automatic welding control system, based on the AFSMC, can perform effectively.

Development of an automatic arc welding system using SMAW process

This paper describes a developed automatic welding control system for alternating current shield metal arc welding. It replaces manual operations which require a well-trained technician. We derived a mathematical model of the welding control system and identified the value of the system parameters thereof. A fuzzy gain scheduling PID controller modulates the rate of an electrode feed mechanism that regulates arc current. The electrode feed rate mechanism with this controller driven by an AC servomotor can both compensate for the molting part of the electrode and the undesirable fluctuation of the arc length during welding operation. It can also be easily applied to any welding system whose electrode is consumed during the welding process. By maintaining the magnitude of the arc current at the desired value and ensuring the stability of the arc length, excellent welding performance can be obtained. The simulation and experimental results both show that this automatic welding control system, based on the fuzzy gain scheduling PID controller, can perform effectively.

Development of an automatic arc welding system using a sliding mode control

This paper describes the development of an automatic welding control system for alternating current shield metal arc welding. This method could replace manual operations which require a well-trained technician. We have derived a mathematical model of the welding control system and identified system parameters. An adaptive sliding mode controller, estimates the bound of uncertainties, and modulates the rate of the electrode feed mechanism that regulates the arc current. The electrode feed-rate mechanism with this controller is driven by an AC servomotor, which can compensate for both the molten part of the electrode and undesirable fluctuations in the arc length during the welding process. The method can be easily applied to any welding system in which the electrode is consumed during the welding process. By maintaining the magnitude of the arc current at the desired value and the stability of the arc length, excellent welding performance is obtained. The simulation and the experimental results both show that this automatic welding control system, based on the adaptive sliding mode controller, can perform effectively.