Determination of edge positions of hot objects using simple IR-sensing elements

This paper deals with novel methods to determine both the lateral edge position as well as the axial distance of a heated planar object employing simple photodiodes. In contrast to an infrared camera a photodiode and the required electronic components are insensitive to mechanical vibrations commonly experienced in industrial fabrication processes. Nevertheless, the limited spatial resolution of such photodiode-ensembles demands for a signal-processing based resolution enhancement, which is presented in this paper. By means of simulation results the efficiency of the novel method is verified.