Research On Arc Welding Seam Tracking System Of Arc Welding Robot Base On Single Chip Microcomputer

With the transformation and upgrading of China's manufacturing industry,arc welding robots are increasingly widely used in industrial production.The organic combination of seam tracking and arc welding robots is one of the important research directions for welding automation.In this paper,an industrial robot is used as a platform and an arc sensor is used to realize the arc swing through the redundancy freedom degree of the robot.The welding torch deviation and working angle during fillet seam tracking are detected and corrected.The research content mainly includes:filter processing of welding current signal software and hardware combination,detection of welding torch deviation and working angle,combination and experiment of welding seam tracking module and arc welding robot.In this paper,the welding current signal is processed by means of hardware filtering and software filtering.Firstly,a second-order Butterworth filter is used as a hardware filter to filter out high-frequency interference signals in the welding current signal.Then,a combination of improved amplitude limiting filter,median filtering,and arithmetic mean filtering is used as the software filtering to filter low-frequency interference signals in the welding current signal.The smoothness of the welding current signal after the filtering of software and hardware is significantly improved,and revivification degree of weld groove information is high,which is conducive to detection of welding torch deviation and working angle.Aiming at the application of traditional integration difference value mean in fillet weld seam tracking and the misjudgment of torch horizontal deviation caused by the changes of torch working angle.Firstly,the text theoretically analyzes the influence of torch working angle and establishes the torch height mathematical model of the working angle,horizontal deviation and height deviation of the welding torch;Then a two-cycle integral difference method is proposed to compare the integral value of the left and right sides of the current cycle with the corresponding integral value of the previous cycle,and the torch height deviation is successfully separated.For the problem of coupling the horizontal deviation and the working angle of the welding torch solved by the double-cycle integral difference method,the dichotomy method is used to approximate the actual welding torch working angle.And the decoupling work of the welding torch horizontal deviation and the working angle is completed.Finally,the torch level deviation,the height deviation of the welding torch and the working angle of the welding torch are successfully extracted from the welding current signal.For the organically combined communication between arc welding robot and weld tracking module,this paper uses RJ45 interface as the basis to achieve data exchanges through Socket Message communication.Firstly,the data is pre-processed and then restored,and the error correction signal is pre-processed as string data at the seam tracking module end.In the arc welding robot,the string data is restored to numerical data,so that the arc welding robot controller successfully recognizes the correction signal;Then take the method of segmenting the welding instructions,and divide a welding instruction into several welding instructions in the unit of the swing cycle;Finally,after the end of each welding instruction,the next welding end point is updated to realize the real-time correction of the weld seam tracking system.In order to verify the feasibility of the weld tracking system developed in this paper,we constructed a two-part weld tracking experiment for the weld seam tracking platform of the arc welding robot.The first part of the experiment uses traditional integral difference method and double-cycle integral difference method to carry out weld seam tracking,and verifies the necessity of taking into account the change of the working angle of the welding torch in the process of seam tracking.In the second part of the experiment,single factor experiments were carried out for different welding torch working angles,welding gun level deviations and welding gun height deviations.The results were compared with Matlab simulation results.The results show that the weld seam tracking system is real-time and effective.