FPGA-Accelerated Distributed Sensing System for Real-Time Industrial Laser Absorption Spectroscopy Tomography at Kilo-Hertz
Jiangnan Xia, Godwin Enemali, Rui Zhang, Yalei Fu, H. McCann, Bin Zhou, Chang Liu
Abstract
Fast and continuous data acquisition (DAQ) with well resolved spectral information is essential for high-speed and high-fidelity measurement of thermophysical parameters of industrial processes using laser absorption spectroscopy tomography (LAST). However, the state-of-the-art DAQ systems suffer: inability to collect raw spectral data in real-time due to the very high data throughput; degradation of spectral integrity when excessive on-chip down-sampling is implemented to reduce data throughput. In this article, we designed a star-networked and reconfigurable DAQ system for real-time LAST imaging at kilo-Hz frame rate. The DAQ system is embedded with a new field programmable gate array (FPGA)-accelerated digital lock-in technique, whereby a cascaded integrator-comb (CIC) filter is implemented for down-sampling of the raw signal with well-maintained spectral information. Furthermore, a customized data-encapsulation protocol is developed to enable continuity of real-time data communication between the front-end DAQ hubs and back-end processor. Performance of the developed DAQ system is experimentally validated by flame temperature imaging at 1 kHz, providing the necessary temporal resolution to penetrate turbulent flow and related industrial processes such as reaction propagation.