Research And Development Of Spiral Seam Tracking Welding Control System Based On Laser Vision Guidance

At present,mechanical tea frying is the main means of tea frying,in which the stir frying tea tube is the core component of the stir frying tea machine,while most of the stir frying tea machine manufacturers adopt the manual welding of the spiral rib plate of the stir frying tea tube.Manual welding has the disadvantages of great harm to human body,low efficiency,unstable welding quality,etc.In addition,the limitations of welding in the tube cause more resistance to manual welding,which always restricts the production quality and efficiency of tea tube.Therefore,in order to improve the welding quality and welding efficiency of the spiral weld in the tea tube,and improve the overall quality of the tea machine,a welding manufacturing scheme based on the tracking of spiral weld seam guided by laser vision is proposed,which can automatically perform spiral welding through visual guidance find welding of welds.First of all,according to the analysis of the forming characteristics of the tea tube,understand the welded parts of the tea tube.After mastering the basic characteristics of the tea tube,the welding process design is carried out,the welding sequence and welding method are determined,and the basic process scheme of welding is determined.According to the structure of the weld and the characteristics of the weld,the welding mode of the carbon dioxide shielded welding is determined,and the welding process parameters are determined according to the type of the tea tube.In order to solve the problem of weld offset caused by machining error,laser vision is used to guide the position.Because of the spiral welding in the tube,the active vision method is used to guide the weld and enhance the image contrast.After determining the active vision method,the structure,installation and shading of the vision sensor are studied,so that the vision system can get clear,stable and non-arc interference field of view pictures.The obtained clear field of view image is extracted from the weld feature points,and the coordinate system of the weld feature points is further transformed.At the same time,the calibration of welding gun is completed,and the relationship between welding gun and weld characteristic points is established.Based on the analysis of the spiral weld and the synthesis of helix,it is determined that the synthesis motion consists of translation motion and rotation motion.Design the mechanical system after determining the motion mode.Rotation movement is realized by A-axis supporting wheel mechanism.Translational motion is realized by cross structure composed of X axis,Y axis,Z axis,B axis and W axis.The fitting of helix is realized by the synchronous movement of the two.On the basis of determining the mechanical structure,the hardware control framework with Panasonic PLC as the core is established to realize the information exchange and data transmission with servo control system,visual system and welding process system.On the basis of the completion of the control system,the software part of the welding system is designed and developed.Firstly,the motion control function of PLC is studied,and then the control flow is analyzed.Based on the establishment of model management database,this paper expounds the automatic starting point searching,the automatic next weld searching and the algorithm of weld correction in the control process.In order to verify the reliability design of automatic welding equipment for welding experiment,through no-load movement and welding movement for experimental design comparison,analysis of experimental data,observation of welding effect,it can be determined that the design scheme can realize the automatic search and welding of stir frying tea tube spiral weld,and the welding effect is good.