Page 33 - Welding Robots Technology, System Issues, and Applications

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Introduction and Overview

Therefore, robotics is a science of generic ingenious mechatronical devices,
precise, powered by a permanent power source and flexible, i.e., open to new ideas
and a stimulus to the imagination. A stimulus so strong that it attracted many of the
best minds of our common history, i.e., authors of the work that constitutes the
legacy that we humans leave for the future.

1.3 Why to Automate Welding?

Robot manipulators came a long way since the early days. Actually robot
manipulators are interesting machines in terms of flexibility, programmability and
precision. Modern manufacturing systems depend increasingly on automatic
equipments, namely robot manipulators. This is an economic choice based on the
following reasons:

1. Robot manipulators can perform industrial tasks in a human-like manner
with at least comparable quality for longer periods of time.
2. Robots manipulators present the best rate between “production cost” and
“production volume” for small/medium production volumes (Figure 1.1).
Actually that is the case of SMEs existing in developing and developed
countries (as an example, SMEs represent more than 95% of the companies
in Europe). In fact, considering actual market conditions (very high
competition, products defined in part by the customers, products with low
life cycles, increasing demand for higher quality at lower prices, etc.)
companies operate based on orders and never risk big stocks (besides the
necessary security stocks) which keeps production on small/medium scale.
3. Robot manipulators are unique flexible machines (mainly due to
programmability) that can be adapted to perform very different tasks.
Consequently, robot manipulators are suitable to be used with
manufacturing setups requiring frequent task changes, which is
fundamental to respond to market changes or to the introduction of new
products.

Let’s consider briefly an industrial solution developed recently (2004) by the first
author. The objective is to justify the above-mentioned arguments just by
introducing a system that takes advantage of robot manipulator capabilities and
computer-based human-machine interfaces (HMI). The presented features are
common to any high-demanding industrial system, namely systems requiring
special human-machine interfaces and a semi-autonomous operation, like robotic
welding.

1.3.1 Example of an SME Based Industrial Robotic System

The industrial robotic system presented in this section was designed to execute the
task of removing the excess of joining PVC material from automobile glasses,