基于背面小孔图像的受控脉冲穿孔PAW控制系统  

Controlled-pulse PAW Control System Based on Backside Keyhole Image

作　　者：黄纯德 钟黎明[1] 刘祖明[2] 

机构地区：[1]国网山西省电力公司电力科学研究院,太原030001 [2]天津大学材料科学与工程学院,天津300350

出　　处：《机械工程学报》2017年第6期68-72,共5页Journal of Mechanical Engineering

基　　金：国家自然科学基金青年(51505329);天津市应用基础与前沿技术研究计划青年(15JCQNJC03400)资助项目

摘　　要：已开发的受控脉冲穿孔等离子弧焊被验证能够较好地控制小孔的穿透行为,提高焊接稳定性,保证焊接质量。然而,过去开发的控制系统使用间接反映小孔穿透状态的尾焰电压作为反馈量,不能够反映熔池的热量状态。前期研究发现,背面小孔参数中,小孔中心位置的变化能够反映熔池热量的变化趋势,脉冲电流下降沿时长能够调节小孔中心位置。本研究,利用摄像机拍摄的背面小孔图像信号为反馈信号,以小孔中心偏移量为被控制量,以脉冲电流下降沿时长为控制量,基于预测控制算法,设计新的受控脉冲穿孔等离子弧焊控制系统。利用新的脉冲穿孔焊接控制系统焊接9.5 mm厚304不锈钢,能够控制小孔周期性稳定穿透,得到了高质量的焊缝。The developed controlled pulse keyholing plasma arc welding control system has been verified to stabilize the keyhole behaviour and improve the process stability, confirm the weld quality. However, the system is developed based on the indirect signals to reflect keyhole penetration state, the feedback signal cannot measure the weld pool thermal state. Previous observation studies to the PAW keyhole behaviour find that, keyhole exit positional parameter is better to predicate the weld pool thermal state evolution than the keyhole dimensional parameters, and the decreasing speed of the welding current in pulse waveform is reliable to adjust the keyhole exit deviation distance. In this paper, a novel controlled pulse keyholing PAW control system is designed by using the keyhole exit image as the feedback signal. In the new system, keyhole exit deviation distance as the controlled factor, falling degree in the welding current pulse as the controlling factor, predicative control algorithm is developed. Bead on welding is conducted on the 9.5 mm thick 304 stainless steel plate to test control system, keyhole process is controlled to open and close smoothly, sound quality weld is obtained.

关 键 词：等离子弧焊 视觉传感 受控脉冲穿孔 控制系统 

分 类 号：TG156[金属学及工艺—热处理]