OCTOBER 19-20, 2012 - YMCA University of Science & Technology

Proceedings of the National Conference on
Trends and Advances in Mechanical Engineering,
YMCA University of Science & Technology, Faridabad, Haryana, Oct 19-20, 2012
Analysis of the Depth of Penetration using Automatic Robotic Arc Welding
System
Anees Ahmed 1 , Dr. Sanjeev Kumar 2 and Ruchika Singh 3
1 Student (M.Tech), Automation & Robotics, Ajay Kumar Garg Engineering College, Ghaziabad
2 Associate Professor, Deptt. of Mechanical Engineering, YMCA UST, Faridabad, Haryana
3 Associate Professor, Deptt. of EN, Krishna Institute of Engineering & Technology, Ghaziabad
Abstract
This paper presents an automatic arc welding system used for the analysis of the depth of penetration on
different specimens welded at different welding speed. Automatic arc welding system has been designed using
mainly a six axes vertically articulated robot, Jigs/fixtures Programmable Logic Controller (PLC), Human
Machine Interface and electrical control panel. Electrical control panel has been used to control the arc welding
robot and jigs/fixtures. The basic system controlling diagram has been presented with I/O address assignment
table. The design of jigs/fixtures has been carried out and selection of servo motors/drives, arc welding robot,
PLC has been made. In this paper, a system has been presented and demonstrated to assist and simplify
industrial welding procedures. The welding current, arc voltage, welding speed and heat input rate are chosen
as welding parameters. Analysis of depth of penetration of welded specimen has been carried out varying the
welding speed. The depth of penetration was measured for each specimen (butt joint) after each weld cycle by
varying the welding speed. A brief overview of actual state of the art about robotic welding technology is
presented. HMI has been used to monitor welding process and to display the corresponding status.
Keywords: Programmable Logic Controller, Arc Welding Robot, Jigs and Fixtures, Human Machine Interface.
1. Introduction
The MIG/MAG welding is also known as gas metal arc welding process, uses the heat of electric arc to melt an
electrode wire and a metallic component to be welded. The fusion is carried out under the protection of gas or a
mixture of gases in order to prevent the contamination with some gases of the atmosphere (oxygen, nitrogen and
hydrogen). MIG is used chiefly in the welding of stainless steel, aluminum alloys and titanium alloys while
MAG is used in carbon steel. In manual arc welding, the labor intensity is high, welding inefficient and difficult
to guarantee the weld quality due to the variation in arc length and welding speed. The first prototype of an
industrial robot was used in Ford in 1961 from Unimation. [1]
Welding process emits sound, light and electromagnetic radiation to surrounded space [2]. Manual welding
process is also dangerous for health and safety. Robotic arc welding system has been used which is controlled by
PLC system in order to analyze the depth of penetration by varying the welding speed. After getting the optimum
penetration, the welding speed is fixed to perform welding on that particular type of specimen. CAD interface
could also be used for fast and simple robot manipulator programming [3].
Jigs and fixtures played major role in this work for positioning and holding the work piece which is to be weld
[4]. HMI has been used to interface the human operator with the machine for setting different input parameters
and getting different machine status such as faults, weld cycle, jig1 and jig2 status, gas ok, air ok, welding torch
tip and home sensor status.
2. MECHANICAL DESIGN
Jigs and fixtures are designed for holding and positioning purpose. In this work, two jigs with fixtures are
designed with same dimensions.
Fig. 1. Schematic of Jigs/fixtures
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