A methodology for "on-line" monitoring system in a welding process using FPGAs

This paper presents both the hardware implementation and the simulation of a Kahnan filter algorithm for detecting "on-line" discontinuities in a Tungsten Inert Gas (TIG) welding process, by using an infrared sensor. For the hardware implementation of the Kaiman filter a Field Programmable Gate Array (FPGA) with 32 bit floating point arithmetic was used. The data used for the simulation proposal were previously acquired through the infrared sensor and stored during an off-line test. Afterwards, the results from the off-line test were analyzed and compared against the results obtained using the "on-line" filter implemented in the hardware, which was described using the VHDL hardware description language. The results of the filter implemented in the FPGA were simulated using the ModelSim tool. Finally, both the estimative consumption and performance of the FPGA are also shown.