关键词: 水下焊接, 潜水送丝系统, 焊丝状态检测, 数字控制

Abstract:

Aiming at the characteristics of underwater robotic welding process,a digital and intelligent underwater wire feeder is developed for the underwater gas metal arc welding.First,a digital control system is constructed with the DSC microcontroller STM32F405RGT6 based on the ARM Cortex^TM - M4 architecture as the control core.Then,a PWM- controlled half- bridge reversible chopper circuit based on the negative feedback of armature voltage is de- signed as the drive circuit,so as to compensate the fluctuation of the wire feeding speed caused by the variation of load torque.Finally,a welding wire detection module based on an eddy current proximity switch is developed,and thus the non- contact and real- time monitoring on the welding wire state is realized. Experimental results indicate that (1) the developed underwater wire feeder can monitor the welding wire state reliably,and feed wire uniformly and stably even when the state of wire feeding tube changes; and (2) the changing rate of wire feeding speed is within ±3.5%,which meets the national standard well.

Key words: underwater welding, underwater wire feeder, welding wire state detection, digital control