Research On Off-line Programming Of Multi-arc Hybrid Robot Welding Applied On Curved Plates

Welding structure accounts for 70% of a ship,and the thickness of ship plate could be up to 30 mm.Traditional multi-layer and multi-passes welding method leads to high labor intensity,low efficiency and unstable quality.In contrast,robot welding technology has advantages of high efficiency and automation rate,stable welding quality,and excellent mechanical property.Moreover,through a special design of welding head,single-pass welding of ships' curved plate can be achieved,so robot welding will be widely applied in the shipbuilding industry.The core technology of robot welding is welding path planning,and there are two ways of teaching: off-line teaching and on-line teaching.During on-line teaching programming,production operations should be suspended,and with the absence of visual sensor tracking,the experience of the programmer could affect the programming quality directly,which reduces the operating efficiency.However,adopting off-line programming technology can reduce downtime and give full play to the use of welding robots.It could not only further improve the automation of the production process,but also shorten the production cycle and improve the welding quality.In this paper,welding robot,LORCH arc welding machines,shielding gas,and self-designed multi-guns and multi-wires welding heads were combined,forming a robotic automated high-efficiency welding workstation.This new workstation is capable of single-pass welding for ships' curved plate,and 15-30 mm thick ship plates welding test was conducted.The three-dimensional modeling software SolidWorks was used to design and model the key components of the real work station,for example,a suitable solution was proposed,which can solve the problem of interference collision between the welding head and the curved plate workpiece during the welding process.Auxiliary models for welding path tracking process were designed to quickly track the precise path curve.The off-line programming software RobotStudio was used to set up a virtual work station to plan and simulate the welding path.A simulation workstation was built with same scale as an actual one,and a tool model with TCP data and Wobj data were designed for the station.Off-line programming and virtual simulation were conducted for the welding path,which verified the feasibility of the multi-heat source hybrid welding equipment.The obtained off-line program was used to guide the welding test in the real workstation.The weld seam tracking system was applied in the robot welding workstation,and it can accurately identify the welding path and dimensions by laser vision sensing technology.As a result,the efficiency and quality of robot welding were improved.