Welding wire monitoring over Internet.

Sintea, Sorin ; Pomazan, Valentina ; Bordea, Nicolae 等

1. INTRODUCTION

Often, the technical support services and data monitoring systems are not placed in the same location with the production units. The ability to remotely access welding cells from the home office to anywhere in the world can yield several benefits. These include quicker response time to problems, improved weld quality, increased production line reliability, and reduced travel time for the specialists. The current trends in manufacturing include an integration of information and knowledge-base network with a manufacturing system. Any production equipment and its control functions become a part of the holistic operation system, with distant monitoring, remote quality control, and fault diagnostic capabilities. Lately the Internet is more and more used as basic information network and data exchange support for long distance information centres and long distance data automation services.

Since welding is of crucial importance for automotive and shipbuilding industries, process remote control gains more importance and requires multifold monitoring capabilities. One control unit can control several welding units, remotely located. This paper presents the remote monitoring approach for the wire consumption and welding unit status (Joni, 2005). The signals acquired by these units are processed by specialized embedded controllers and are included in SCADA data management system. The main capabilities of this equipment are:

* Signalling of welding equipment status on a local interface;

* Changing the welding automated robots algorithm according to the monitored parameters status;

* Data exchange with SCADA system regarding the welding equipments functionality;

* Centralized display of the welding equipments functional parameters.

Research done at the beginning of '70s concluded with several equipments, each responsible for only one function as parts of welding technological monitoring subsystem, having important role in the process automation (Schmidt, 2002). Large scale integration and communication techniques advances in nowadays allowed to embed all the function in a single data monitoring controller. A welding monitoring subsystem consists of several welding monitoring controllers connected via a network. Several robots or welding controllers can be supervised by a single data monitoring unit, as showed in figure 1. They can stand independently or linked and steered from a SCADA control network (Margineanu, 2005).

[FIGURE 1 OMITTED]

The presented equipment was implemented by our research team and works in live industrial environment via a communication channel integrated into the factory data communication network (including also the SCADA system) (Schmidt 2002). The conversion of communications technology to TCP/IP over Ethernet (IEEE 802.x standards), ended with the inclusion of the SCADA network in the factory's informatics system. The SCADA network is the communication system layer between command equipments and control units of the automated process, which simplifies the integration of the new equipment, as SCADA architecture is easy to edit. These new communication structures create more facilities for the addition of new equipments and the development of the data architecture automation.

2. WELDING WIRE MONITORING IMPLEMENTATION VIA INTERNET

ELCo "Wizard View 2" data acquisition controller (ELCo, 2009) was used for the implementation of welding wire monitoring system. This controller is connected with a welding torch or welding automated robot signals. Using this unit we measured the wire speed signal using ELCo PAWFS-540 wire sensor and the wire motor load current through U_[R.sub.d]'s HCS-36-500-AP current sensor (500A/4V sensor) (see Fig. 2.) (Zaciu, 2002).

The controller calculates the wire welding consumption and monitors the wire motor load functionality during the welding time (ELCo, 2009). The controller's digital inputs are connected with outputs from welding control equipment (for information regarding the welding robot status or welding controller status readings) and to the welding torch for reading of welding parameters. The digital outputs of this controller are connected to the inputs of welding controller in order to give possibility to change the welding algorithm and welding conditions in according with current status read by the monitoring system.

[FIGURE 2 OMITTED]

On the Internet web pages the controller presents the following data acquired and calculated (Fig.3.):

* The welding index, welding time and welding time stamp.

* The weight and length of wire consumed during the welding process

The status of wire motor load (the current consumed and the motor load factor). All presented data are also accessible in XML data format. This format permits easy access and further achieves storage for welding parameters history (logs) on external data server. This server was organized on a three-fold purpose basis: a) Data communications service, named "wv Central Service". This module receives all welding parameters from the controller and stores them on the data server (as sown in figure 4.); b) Data server functionality, installed on the same computer; c) The implementation of the web application for data display, named "wv Central App" using an Apache web server (presented in figure 4), running on the same computer. This friendly web page structured interface, all the data stored on the data server can be accessed and analysed.

[FIGURE 3 OMITTED]

3. RESULTS

Measuring and analyzing the wire speed factor and the wire motor load factor in welding one can have access to the status of wire supplying mechanism, predict material consumption and undertake rapid reaction to any process events. Wire supply problems can be solved in due in time, and unwanted functionality gaps in the welding process can be successfully avoided. The device allows a smooth welding process while monitoring critical parameters as wire motor load, rolling wire mechanism.

[FIGURE 4 OMITTED]

Adding this new feature to welding units it is possible to:

* Shorten the wire supply time for welding automated machines. This can increase the productivity and provides automation support for the entire supplying process in the plant.

* Develop remote maintenance schemes. The automation of the monitoring process for welding machines signals the problems that might appear and permits rapid decisions and quicker response time to problems.

4. CONCLUSIONS

The equipment presented adds new wire supply control features for automated plants. Optimized and rational supply are the main outcomes of this developed version of "Wizard View 1" monitoring system, with new featured added (Sintea 2008). The system improves also the monitoring of welding units functionality during the welding process. It allows further developments as new elements can be added into the external controller or PLC (programmable logic controller). Fuzzy logic algorithms can be used for in situ reading and correction of the welding algorithms, according with data issued by the welding monitoring equipment. The data collected can be centralized at manufacturing unit level for analysis, prognosis and decisions, envisaging a more reliable welding and production process.

The new "Wizard View 2" controller can be programmed to send data over Ethernet port to a central server, creating a central welding monitor system. All data centralized on the server level can be accessed by any specialist involved in the welding process. Data are easily accessed and displayed on web pages, due to its Internet networking facilities. The presented equipment offers a real time solution for process monitoring while improving the existing automated systems implemented at factory level, completing them with new functions.

5. REFERENCES

Joni, N. & Trif, N. (2005). Automated Electrical Arc Welding, LUX Libris, ISBN 973-9495-34-3, Brasov, Romania

Margineanu, I. (2005). Programmable Controllers, Blue Editor, ISBN 973-650-156-6, Cluj Napoca, Romania

Schmidt, J. S. (2002). Protocols for interconnecting the components of a welding system, -, IIW DOC XII-1697-02, Lisboa

Sintea, S., Cooper, L. E., Grebenisan, D. & Bordea, N (2008). Method for Welding Wire Consumption Optimization, DAAAM 2008, ISSN 1726-9679, Trnava, Slovakia

Zaciu, R. (2002). Signals Digital Editing, Blue Editor, ISBN 973-650-095-0, Cluj Napoca, Romania

*** ELCo Enterprises Inc. (2009), Wizard View 2. User Manual, rev. A., ELCo Enterprises Inc, --, Jackson, Michigan, USA