基于辐射本底扣除和对数放大的TDLAS燃烧温度快速反演OA

To address the limitation that traditional TDLAS systems fail to meet the millisecond-scale transient combustion measurement requirements of engines because of processing delays introduced by complex spectral line fitting and numerical inversion algorithms,a rapid hardware-based spectral process-ing system using logarithmic amplification is proposed and developed.The study covers the overall system architecture,the design of an automatic background radiation subtraction circuit,the logarithmic amplifica-tion circuit,algorithmic correction methods,and the real-time data processing framework.In the analog front end,a proprietary background radiation subtraction circuit and a logarithmic ratio amplifier based on the LOG114 chip are employed to directly output a voltage signal proportional to absorbance.In the digital section,a field-programmable gate array(FPGA)is used for high-speed data acquisition and absorbance integration accumulation,followed by temperature inversion calculations implemented on a microcon-troller.Experimental results show that,at a scanning frequency of 100 kHz,stable background radiation subtraction is achieved,and a single temperature calculation requires approximately 2.5 ms.The system is therefore capable of rapidly measuring high-temperature flow fields at millisecond intervals and is expect-ed to capture transient combustion variations in engines.