• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2017, Vol. 53 ›› Issue (6): 68-72.doi: 10.3901/JME.2017.06.068

• 材料科学与工程 • 上一篇    下一篇

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基于背面小孔图像的受控脉冲穿孔PAW控制系统*

黄纯德1, 钟黎明1, 刘祖明2   

  1. 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
  • 出版日期:2017-03-20 发布日期:2017-03-20
  • 作者简介:黄纯德,男,1979年出生,高级工程师,材料所所长。主要研究方向为电厂电网金属材料成形及检测。E-mail:jinshushi2005@126.com刘祖明(通信作者),男,1984年出生,博士,讲师,硕士研究生导师。主要研究方向为焊接过程检测与控制、先进焊接工艺方法。E-mail:zuming.liu@tju.edu.cn
  • 基金资助:
    * 国家自然科学基金青年(51505329)和天津市应用基础与前沿技术研究计划青年(15JCQNJC03400)资助项目; 20160302收到初稿,20170106收到修改稿;

Controlled-pulse PAW Control System Based on Backside Keyhole Image

HUANG Chunde1, ZHONG Liming1, LIU Zuming2   

  1. 1. Electric Research Institute, State Grid Shanxi Electric Power, Taiyuan 030001;
    2. School of Materials Science and Engineering, Tianjin University, Tianjin 300350
  • Online:2017-03-20 Published:2017-03-20

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。

关键词: 控制系统, 视觉传感, 受控脉冲穿孔, 等离子弧焊

Abstract:

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.

Key words: control system, controlled pulse keyholing, vision-observation, plasma arc welding