脉冲MIG焊电弧双模模糊控制

Double-model fuzzy logic control strategy of arc in pulsed metal inertia gas welding

针对脉冲M IG焊焊钢时的电弧稳定性控制,采用峰值弧压反馈的方式,设计了基于修正因子的电弧双模模糊控制器,当峰值弧压偏差较大时采用基于修正因子的粗调模糊控制规则,以送丝速度Vf为控制量,而当峰值弧压偏差较小时采用基于修正因子的细调模糊控制规则,以基值时间Tb为控制量,以查表方式实现模糊控制器.最后通过试验验证了在焊接过程中弧长变化时所设计的模糊控制器可保持电弧的稳定从而保证焊接过程的稳定.

According to the feature of arc control in welding steel using pulsed metal inertia gas（MIG） welding, a correction-factor-based double-model fuzzy logic controller （FLC） was developed to realize the stability of arc control by means of feedback of peak arc voltage. When the difference of peak arc voltage is high, a coarse adjusting fuzzy control rule with correction factor is designed, the peak arc voltage is controlled by the wire feeding speed by means of feedback of peak arc voltage. When the difference of peak arc voltage is small, a fine adjusting fuzzy control rule with correction factor is designed, the peak arc voltage is controlled by the pulse base time by means of feedback of arc voltage. The FLC is realized in a Look-Up-Table （LUT） method. An experiment has been carried out, aiming at implementing the control strategy to control the arc length change in welding process. The experiment result shows that the＇ proposed controller enables the stability of arc and welding process to be achieved in pulsed MIG welding process.