Research Of The Truck Base Plates Automatic Welding Robot System Based On The Laser Tracking Technology

With the development of transportation and the improvement of road capacity,dump trucks and trailers have gradually developed to lighter weight,and the structure of cargo compartments has become more and more abundant.Welding is an important processing method in the process of dump trucks manufacturing.The bottom plate of dump trucks is the key structural component for the load-bearing dump trucks,due to its complicated structures,manual welding is often used to make it,but the labor cost of artificial welding is high and it is harmful to the human body.The welding efficiency of universal robot is low,and the welding torch trajectory is easily deviated from the actual weld by the thermal deformation of the welding.Therefore,in order to realize the automatic welding processing of the dump truck bottom plate and ensure the stability of the welding trajectory,we developed an automatic welding robot system based on laser tracking technology combined with off-line programming technology and motion control technology.In order to determine the automatic welding implementation method and ensure that the welding system meets the requirements of the dump truck floor welding,the subject studied the manufacturing process of the bottom plate and the characteristics of the weld at first.On this basis,the position information needed for welding and the welding process of the welding robot are determined.The method of off-line planning of welding task based on key points and the welding seam tracking mode of point position deviation correction were developed.The welding path and task planning scheme of the bottom plate are studied.In order to solve the problem of low efficiency of manual programming,an off-line programming system for the bottom plate welding of dump trucks was established.The development method of off-line programming software based on secondary development of Solidworks was determined,which solved the problems of weld seam identification,welding task planning,path optimization,coordinate system calibration,processing file generation,etc.In off-line programming system,it can realize the automatic generation of welding and machining files of imported a 3D model.According to the welding process and welding requirements,the mechanical structure and control system hardware composition of the dumping floor welding robots are determined.The gantry-type rectangular coordinate mechanical structure and two-point laser tracking method were determined.The overall scheme of the control system with the GOOGOL controller as the core was established,and the related I/O interface and driving scheme were designed.Based on the control system scheme,the laser tracker installation method was determined,the laser tracking weld identification and track correction research were completed,and the laser data processing method of slope judgment and deviation calculation of was proposed,which solved the problem of deviation acquisition,correction and integration with off-line processing program in the system.It can improve the welding precision,reduce the influence of workpiece error,positioning error and thermal deformation in the welding of the bottom plate of dump truck.The control system software development on motion control,weld tracking,and off-line programming systems were completed.The compilation method of NC code and the method of rectification function of automatic processing module in NC system were studied.The man-machine interface was designed,and the NC welding system of dump truck bottom plate welding robot which can be imported into off-line program was established.In order to verify the stability of the system and the welding effect,the welding experiment was carried out on the bottom plate welding system of the dump truck.From the final welding effect,it can be concluded that the system is capable of welding a uniform and complete weld seam to achieve a predetermined function.