Research On Gas Detection And Identification Method Based On Chalcogenide

The international situation is complex and ever-changing,regional conflicts occur from time to time,and the threat of a cold war and a hot war continues.In order to protect the national military security and people’s life security,a fast and accurate chemical gas detection and identification method is required.In this paper,for the purpose of qualitative and quantitative detection of mustard gas and sarin gas,a detection system and corresponding theoretical method are designed in a simulated battlefield environment.Mainly carried out the following work:（1）The paper selects graphene composite molybdenum disulfide（Mo S₂-r GO）,graphene composite zinc disulfide（Sn S₂-r GO）,niobium-doped molybdenum disulfide（Nb-Mo S₂）,vanadium-doped molybdenum disulfide（V-Mo S₂）and tungsten diselenide（WSe₂）five materials to make semiconductor gas sensing array.The gas sensor array has good sensitivity,repeatability and selectivity through preliminary experiments on NH₃and NO₂gases.（2）Design a semiconductor gas sensor detection circuit based on FPGA,and realize the cross-response of the gas sensor array in the toxic gas environment by using the characteristics of rich FPGA resources and strong development flexibility.It provides a data basis for building gas identification and detection models.（3）In view of the existence of cross-sensitivity in the data obtained by the gas sensor array,a gas sensor array recognition method based on pattern recognition is proposed in this paper.By comparing the two methods of support vector machine and BP neural network,the effect of the pattern recognition method based on support vector machine is better than that of BP neural network under the condition of small samples.The genetic algorithm was used to improve the support vector machine model,and the parameter optimization model of GA-SVM was formed.The classification accuracy rate reached 100%,and the average absolute percentage error of concentration prediction was increased by 3.38%.This paper takes"sensor preparation-detection circuit design-pattern recognition"as the route,and designs a fast and accurate gas identification and detection system,which provides a new solution for environmental security from the perspective of military and civilians,and is of great importance for ensuring environmental security.realistic meaning.