The significance and difficulty of deepwater welding applied in offshore engineering were described as well as several new technologies such as hyperbaric TIG welding, hyperbaric MIG welding and friction stitch welding were introduced.

This paper introduces hyperbaric TIG welding and the research works finished by BIPT Underwater Joining Group,especially several new technologies such as hyperbaric MIG welding,friction stir welding,friction stitch welding and radial friction welding,which can satisfy the future demands of deepwater engineering.

Simulation of MIG welding control system for aluminum alloy;

Pulsed MIG welding digital control system based on DSP;

Sensing and controlling system of welding torch position in MIG welding;

Application of Fuzzy Control Technology in MIG Welding Pool Width;

Fuzzy Control System for MIG Weld Pool Width;

Processing Research of Tandem Pulsed MIG Welding;

Design and simulation of intelligent PID controller for aluminum alloy pulsed MIG welding process;

Research on a waveform control method for pulsed MIG welding based on DSP;

Situation and expectation on pulsed MIG welding control technique;

Identification of aluminum alloy pulsed metal inert-gas welding dynamic process;

Median waveform control method for pulsed metal inert-gas welding;

In order to control stable droplet transfer in pulsed metal inert-gas welding,the forward median waveform control method was proposed,which adding median current between the two peaks of pulse current.