Dual-torch Automatic Welding Machine Control System Design Based On Obstacle-avoidance

T-tube radiator weld seam is a complex three-dimensional space curve and there is aluminum wing obstacle at vertical direction, interference phenomenon between risers at horizontal direction. It is difficult to achieve automatic continuous welding. then developed a new steel radiator automatic welding system based on research of welding technology of T-tube radiator welding seam, in order to achieve low-cost, high-efficient, high-quality automatic welding of T-tube radiator.Through analyzing the intersecting space curve and the trajectory of torch fuse point, it established the mathematical model of intersection line and two torcher oscillation in real-time which is used to ensure optimum welding angle. Then it introduced a real-time interpolation algorithm with controllable step length for the automatic welding of T-tube radiator weld seam and did simulation analysis for interpolation algorithm using Matlab software. The control system uses the typical control structure of"PC+multi-axis controller"which is with integration of IPC as upper computer and 6K4 controller and MCS-51 embedded control system as paralleled lower computers. The upper machine developed application program by Visual Basic language which used to realize the system of management, control functions, some real-time tasks which is not strong and multi-task coordination. 6K4 controller developed welding motion control program using using its unique 6000 programming language to complete the linkage and interpolation of axes, the process of control signals of arc welding machine and fiber detection signals, welding speed control, Ethernet communication between IPC and 6K4 controller; MCS-51 embedded control system complete power up order of servo system, real-time signal processing of the control panel, RS232 serial communication between MCS-51 system and IPC, and so on.In order to implement synchronization of optimum welding angles in welding process of T-tube intersection when using two torches simultaneous welding, a new two stepping motors synchronous drive system was densigned: syschronous driving two stepper drive systems based on same group control pulse signals of a servo axis of 6K4 controller. And the stepper drive systems were used to drive two welding torches separately which achieved two torches'accurate synchronous movement at low speed when load disturbance is little. Established the mathematical model of welding torch drive system, and then used MATAB to research system dynamic reponse and its static reponse. Then improved drive system of welding torch based on analysis results and ahieve oscillating error is less than±0.3mm when division driver's parameters is set properly (16 segments, 2.7A) and torch oscillating speed changes between 5°/s and 15°/s.Selected a certain size radiator and welded it with dual-torch automatic welding machine based on obstacle-avoidance. The results shows: the welding machine can be used to achieve continuous and automatic weld of T-tube radiator intersection when welding parameters are set properly and it has high welding efficiency, good bead shape and stable welding quality.