Resistance weld control with line impedance compensation
US6013892A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 27, 1998 |
| Grant date | Jan 11, 2000 |
| Priority date | — |
| Expiry date | Jan 27, 2018 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K11/252
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A phase controlled weld controller system uses an internal model of weld line and load impedance and of open circuit weld input voltage to develop a nominal firing angle sequence to maintain a desired weld current sequence. The weld controller computes a nominal firing angle sequence based on estimated models of line impedance, open circuit line voltage, and an estimated relation between the load current and conduction angle and the mathematical relation between firing angle, conduction angle and load circuit power that will achieve a desired weld sequence if the models are accurate. The weld controller subsequently uses measured values received in real time while the weld sequence is being executed to modify the nominal firing angle to better achieve the desired objective. This approach allows the weld controller to quickly achieve the desired weld sequence with the actual load, while permitting low feedback gains, resulting in a system that is quick and accurate in response without being overly sensitive.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.