基于焊工调节的铝合金脉冲MIG焊背面熔透建模

针对铝合金薄板脉冲MIG焊背面熔透难题，提出一种基于焊工调节的背面熔透建模与控制方法.设计焊接速度随机变化波形，致使铝合金背面熔池尺寸动态波动，采用被动视觉系统实时采集背面熔池图像，焊工观察图像熔池大小，手工调节焊接电流保证背面熔宽的均匀性，同时开发图像处理算法提取背面熔宽.采用最小二乘系统辨识法建立焊工调节电流与背面熔宽的非线性Hammerstein模型.开展了铝合金脉冲MIG焊电流扰动和焊接速度扰动试验.结果表明，基于焊工调节的非线性Hammerstein模型可以有效地控制背面熔宽，且具有良好的抗干扰能力.

Penetration modeling of back-side bead in aluminum alloys pulsed MIG welding based on human welder adjustment

Aiming at the problem of back-side penetration in aluminum alloy pulsed MIG welding, a method for modeling and control of back-side penetration was proposed based on the experience of human welders. A random variable waveform of welding speed was designed to make the weld pool geometry change. A passive visual sensing system was used to detect the of back-side image of molten pool. The welder observed the molten pool and adjusted the welding current to keep the molten pool width consistent. At the same time, the molten pool width was extracted by developing image processing algorithms. A nonlinear Hammerstein model between adjusted current and back-side width was established by a least square system identification method. Current and welding speed disturbance experiments were carried out. The results showed that the nonlinear Hammerstein model based on human welder experience can control back-side penetration effectively, and it has a strong anti-interference ability.