*3.1. Experimental Platform*

In this work, corresponding experimental design had been conducted. The experimental platform was composed of a FANUC Robot M-10IA industrial robot (FANUS Corporation, Oshino-mura, Yamanashi Prefecture, Japan), a LORCH S-RobotMIG arc welding machine (Lorch Schweißtechnik GmbH, Im Anwänder, Auenwald, Germany), a wire feeder machine, a welding torch and other auxiliary equipment. During the experimental process, the industrial robot controlled the welding speed, the current waveforms in TPP and TBP were controlled by the LORCH arc welding machine. In addition, one self-designed robot welding multi-signals collection and analysis instrument, which was based on the USB-6363 data acquisition card developed by NI (National Instruments) company (Austin, TA, USA), can be utilized to synchronously collect and analyze the current, voltage, arc sound signals. Figure 2 presented corresponding experimental instruments.

**Figure 2.** Experimental instruments and equipment.

Where two cabinets were used in the experiment. The robot control cabinet was responsible for the robot control operation, while the cooperative control cabinet was responsible for coordinately controlling the DP-GMAW process and robot operation.
