TWI Industrial Member Report Summary 652/1998
W Lucas and J Tapp
There are a number of dedicated, commercially available instruments that will perform low speed data acquisition, and these instruments are adequate for undertaking the most rudimentary process monitoring. However, to investigate arc and weld pool stability there is a requirement to record short term fluctuations in the welding current, arc voltage and wire feed waveforms. As the commercially available arc monitors operate at too low a sampling rate to record these fluctuations, special purpose instrumentation is required.
A PC based arc monitor has been developed in this project for recording arc welding parameters. It is only through the availability of high processing speeds and greater memory that the PC can achieve the data acquisition rates required for recording complex waveforms. By using the PC monitor, algorithms can be derived to produce a numerical indication of the process performance. It is expected that analysis of the waveform will yield information on:
- Process stability
- Parameter optimisation
- Weld integrity
This report details the development of the monitor for data acquisition rather than its use as a tool for determining the algorithms. It is intended that the second phase of the work will use the PC monitor to establish transient data patterns and from these the control algorithms.