Research On Gas Detection Technology In Space Life Science

China’s three-step manned space flight plan has entered the crucial third,the construction of the space station has been carried out to the astronauts long-term duty stage,the space station is completed,in its experimental cabin to carry out a large number of life sciences experiment.In space life science experiments,the presence or absence of trace gases has an important effect on the progress and results of the experiments.If the aeronautical component,which is influential to the astronauts in the culture,is directly discharged into the tank without detection and treatment,it is likely to affect the astronauts’ orbital life,and therefore the gas generated in the space life sciences There is an urgent need for real-time quantitative analysis of component gases.In order to carry out real-time quantitative detection of the gas produced in the life science experiment,a multi-component gas detection system based on Fourier transform infrared spectroscopy was designed.The main research contents and achievements are as follows:1)Compared with a variety of trace gas analysis methods,the development of gas components inside the development of the status quo,according to the space application for weight,volume,power consumption and reliability constraints,and ultimately identified the system based on Fourier transform infrared spectrometer.2)Analysis of the sources and characteristics of carbon dioxide and ethylene,which need to be focused on the space life science incubator.Based on the absorption potential of the gas molecules,the absorption spectra of carbon dioxide and ethylene molecules in the middle infrared band and the absorption lines of methane,carbon monoxide and water vapor in the database were retrieved,and the gas concentration The spectral range used in the play.The principle of the infrared spectrometer is analyzed,and the influence of the error generated by the laser metering system on the acquisition of the infrared spectrum is deduced.3)Designed the laser measurement and analysis system in the space life science instrument,carried out the performance evaluation,completed the Fourier transform infrared spectrometer subsystem,the optical path of the long path gas pool and the design of the gas pool window,and finally completed the principle prototype Build.4)The spectral preprocessing method based on wavelet transform is designed.The method can pretreat the poor quality spectrum and analyze the advantages and disadvantages of least squares method,principal component regression method and partial least squares method.Least Square Method for Gas Density Information Fitting and Inversion.The algorithm is evaluated by using different concentrations of ethylene standard gas.It is proved that the current inversion results of the algorithm can meet the needs of scientific experiments,and the gas composition of the artificial climate chamber is analyzed.