Rotating Arc Sensor Research Articles

The System Design of an Autonomous Mobile Welding Robot

The welding robot system designed in this paper is helpful to realize welding automation. The closed loop control system and algorithm of arc rotating speed have been designed, so arc rotating speed was stabilized near the set value and the tracking accuracy of fillet weld has been improved by the rotating arc sensor. A data acquisition system and a motion control system have been designed based on multi-sensor technology. The mapping relationship between the features in the welding seam image and the pose of the welding gun was established, so as to realize the identification of the pose of the welding gun based on three-wire laser vision sensing technology. The effect of wire extension, welding currents and welding voltages on the current waveform was investigated based on the rotating arc sensor. By using the designed system and algorithm, the welding deviations recognition experiment, the arc rotating speed control experiment and the tracking experiment of the right-angle welding seam have been carried out. The experimental results showed that the welding deviations were located within [Formula: see text][Formula: see text]mm, and the welding robot can track the complex welding seam accurately and reliably.

Seam tracking system based on rotating arc sensor for robot arc welding

Rotating arc sensor is applied to acquire V-shape groove contour information through the change of welding current signals. Most of the current signals which are acquired by NI acquisition card are disturbed by noise, so the wavelet filter and median filter is used to remove the noise. PCA_nu-SVR method is used to discriminant the weld seam centre position through input signals. Command about seam offset is sent to the welding robot with the serial communication to control the movement of torch. The tracking experiment of sidelong shows that the system can meet the demand of the tracking precision.

Realization of rectangular fillet weld tracking based on rotating arc sensors and analysis of experimental results in gas metal arc welding

Abstract In order to improve the welding quality and efficiency of the rectangular fillet weld in the shipyard and the steel structure workshop, reduce the labor cost, and improve the welding automation, it is necessary to study a welding robot that can track rectangular fillet weld. The working principle of the rotating arc sensor has been studied, and the mathematical model of the space posture of the arc welding gun has been established. The equivalent link coordinate systems of the wheeled mobile robot have been built, and the jacobian matrix of the robot and its inverse matrix have been calculated. The transformation from the operational space speed to the joint space speed has been realized by using the inverse matrix of the jacobian matrix, and the trajectory planning of the welding robot has been finished. The tracking algorithms of the linear fillet weld and the rectangular fillet weld have been studied, and the rectangular fillet weld tracking experiment has been done in the laboratory and the factory. Experimental results showed that the welding robot can track the rectangular fillet weld with high accuracy and good reliability.

Dynamic Balance Design of the Rotating Arc Sensor Based on PSO Algorithm

Dynamic balancing is a key issue for rotating arc sensor (RAS). It causes vibration during welding, and has an influence on reliable welding signal collection. It is a very significant thing to find a quick design methodology for RAS dynamic balancing structure, especially in restricted space. With the help of PROE and ADAMS virtual prototype technology, and the dynamic balancing analysis of the counterbalance, the unbalanced inertial force and the balance-weight-plane can be determined. Based on PSO (Particle Swarm Optimization) algorithm and the range of parameters according to RAS space dimension, the counterbalance dynamic balancing structure are achieved in which three parameters of the counterbalance are considered. It shows the optimized RAS structure has a lower vibration. The paper provides a novel dynamic balancing design methodology for RAS.

Circular fillet weld tracking in GMAW by robots based on rotating arc sensors

In order to reduce the welding cost, improve the welding quality, and enhance the automation level of the welding, the circular fillet weld tracking algorithm was studied based on the coordinated movement between wheels and a horizontal slider, and the tracking algorithm can eliminate the impact on the welding quality due to roundness errors of the circular fillet weld in the plane. Furthermore, the circular fillet weld tracking algorithm was studied based on the vertical slider moving up or down, and this algorithm can eliminate the influence on the welding quality due to flatness errors of the circular fillet weld in the vertical direction. By using the circular fillet weld tracking algorithm that robots track the circular fillet weld based on the coordinated movement among wheels, the vertical and horizontal sliders, a large number of experiments have been done in the laboratory and the factory. For example, robots tracked the circular fillet weld with different diameters in the laboratory, and the circular fillet weld of the flat bottom container was tracked by robots in the factory. At last, the deviation that the arc welding gun deviated from the weld seam was analyzed, and the experimental results show that the robot based on the rotating arc sensor can track the circular fillet weld with high accuracy and good reliability by using the designed algorithm in gas metal arc welding.

Welding Seam Error Research based on Multi-Pass Welding of Rotating Arc Sensor

Welding Seam Error Research based on Multi-Pass Welding of Rotating Arc Sensor

The Study on Weld Tracking of TIG Based on Rotating Arc

Aimed at the situation that the welding voltage is easy to be disturbed by the voice outside, median filtering and average filtering are adopted to filtering signal of the voltage the rotating arc sensor collected in this paper. They can make the voltage waveform get obvious improvement. In order to get information which the welding torch deviated the welding seam more accurately, left and right integration, Characteristic Harmonics method and welding torch deviation recognition algorithm are adopted to identify the deviations in this paper. Finally compare the two kinds of identification deviation methods and obtain better welding torch deviated information.

Fuzzy based welding seam tracking control for gmaw with rotating arc sensor.

Fuzzy based welding seam tracking control for gmaw with rotating arc sensor.

Fillet Welding Seam Tracking Based on a Mobile Robot with Rotational Arc Sensor

The control method of tracking rectangle-corner fillets based on wheeled mobile robot with rotational arc sensor is researched.For the lined welding seam tracking,a multi-segment controller is designed which is composed of a proportion controller and a self-turning fuzzy controller to control horizontal slider.When the deviation is large the proportion controller will be used to quickly reduce the deviation,otherwise the self-turning fuzzy controller will be used to avoid overshoot and achieve smooth tracking,and the immunity feedback method is used to modify proportion gene of fuzzy controller.A kinematics mathematical model of robot is built for tracking rectangle-corner fillet seams.The welding torch inclination is used to detect rectangle corner,and ultrasonic sensor is used to detect the frontage welding seam position.A fuzzy compromise controller is designed to carry out coordinated control of wheels and horizontal slider of robot.Actual welding test proves the effectiveness of the method.

Mathematic model of high speed rotational arc sensor

A mathematical model of high speed rotational arc sensor, which is used in gas metal arc welding (GMAW) of fillet joints, is developed. It is based on the mathematical model of GMA welding system and Halmoy's wire melting model. The variations of welding current, arc length and wire extension are simulated by using the developed model. It is shown that the simulation results of welding current, arc length and wire extension agree with the experimental results in fillet joints. Based on the mathematical model, the variation of arc length is bigger than that of wire extension. The deviation and direction of the welding gun can be detected by the difference between the left half-cycle current and the right half-cycle current during each torch rotational cycle. In addition, the end point of the fillet joint can be detected by the average current value in each torch rotational cycle. The mathematical model developed is helpful to the design and application of high speed rotational arc sensors.

Mathematical modelling of rotational arc sensor in GMAW and its applications to seam tracking and endpoint detection

High speed rotational arc sensing is an important method to detect the torch deviation during automatic seam tracking of arc welding. In the present paper, a mathematic model of high speed rotational arc sensing is analysed. Simulations have been implemented in two conditions, namely considering or without considering weld bead profile. The simulation results are consistent with the experimental results. The current waveforms at the beginning of the welding are different from those at middle of the welding because of the formation of the weld bead profile. The signal patterns for seam tracking and endpoint detection are proposed. A phase shift between the rotation and the current variation is also discovered in the experiments. The mathematical model can be helpful for the interpretation and improvement of arc sensing systems.