卡尔曼滤波焊缝跟踪控制.pdfVIP

第24卷第6期 控 制 理 论 与 应 用 、b1．24 No．6 2007年l2月 Control TheoryApplications Dec．20o7 文章编号：1000—8152(2007)06—0977—04 卡尔曼滤波焊缝跟踪控制 高向东，陈永平，袁弱男，李桂华，陈章兰 (广东工业大学机电工程学院，广东广州510006) 摘要：在视觉传感的电弧自动焊接过程中，需要根据视觉信息来控制电弧准确地跟踪焊缝．由于强烈的弧光干 扰，使得从焊接区图像中直接提取电弧与焊缝的偏差信息十分困难．为此提出～种利用熔池图像质心和卡尔曼滤波 来间接获取电弧与焊缝偏差的方法．选择熔池图像质心作为状态向量，建立基于图像质心的状态方程和焊缝位置 测量方程．利用卡尔曼滤波消除过程噪声和测量噪声的影响，通过对熔池图像质心的状态估计，准确获取焊缝位置 以及电弧与焊缝之间的偏差量，为自动焊接过程的焊缝跟踪控制提供准确信息．焊接试验结果表明，利用卡尔曼滤 波方法可有效降低过程噪声和测量噪声的影响，从而提高焊缝跟踪控制精度． 关键词：焊缝跟踪：卡尔曼滤波：熔池图像质心 中图分类号：TG316．7 文献标识码：A Seam tracking control using a Kalman filter GAO Xiang—dong，CHEN Yong—ping，YUAN Ruo—nan，LI Gui—hua，CHEN Zhang—lan (Faculty of Mechanical and Electrical Engineering，Guangdong University of Technology， Guang~ou Guangdong 5 10006，China) Abstract：During an automatic arc welding process which visual sensors are used，the electric arc should be controlled to track the weld seam accurately based on the visual sensing information．However,it is very di币cult to acquire the deviation between the electric arc and the weld seam from the welding images because of strong arc disturbance．An approach is proposed that this deviation Can be obtained by using the weld pool image centroid and a Kalman filter．1_he centroid of the weld pool image from a visual sensor iS extracted as the measurement eigenvector．Based on the weld pool image centroid．the state equation and the weld position measurement equation ale established．111e advantages Of a Kalman filter is taken to reduce the error of weld detection caused by the process and the measurement noises．Also，the weld position and the dev