Page 154 - Welding Robots Technology, System Issues, and Applications

Robotic Welding: System Issues 141

To operate the system, using the same TCP/IP sockets strategy, the calling
computer should send the welding parameterization, using the available services,
and command “automatic mode” to start production. This can be done from any
computer on the network, namely from computers running the software used to
track and control the production. In many industries, production is closed tracked
in any part of the manufacturing cycle, which is composed by several in-line
manufacturing systems that perform the necessary operations transforming the raw
materials in a final product. In many cases, if properly designed, those individual
manufacturing systems require simple parameterization (like the robot welding
tasks) to execute the tasks they are designed to execute. If that parameterization
can be commanded remotely by automatic means from where it is available, then
the system becomes almost autonomous in the sense that operator intervention is
reduced to the minimum and essentially related with error and maintenance
situations. A system like this will improve efficiency and agility, since it is less
dependent on human operators. Also, since those systems are built under
distributed frameworks, based on client-server software architectures which require
a collection of functions that implement the system functionality, it is easier to
change production by adjusting parameterization (a software task now) which also
contributes to agility. In adition, since all information about each item produced is
available in the manufacturing tracking software, it is logical to use it to command
some of the shop-floor manufacturing systems, namely the ones that require simple
parameterization to work properly. This procedure would take advantage of the
available information and computing infrastructure, avoiding unnecessary operator
interfaces to command the system. Also, further potential gains in terms of
flexibility and productivity are evident.

Furthermore, to adjust the welding parameters and start production in the simple
welding example presented, the collection of commands would be:

Set the welding current
Connect
Send message: variable_write feed_ref num value
Close

Set the welding voltage
Connect
Send message: variable_write wd_ref num value
Close

Set the welding velocity
Connect
Send message: variable_write velocity num value
Close

Note: these three commands are used to define the welding parameters. They can
be done once, and/or adjusted during production, or done asynchronously in any
combination, without being followed by the “automatic mode” command. This