Research On Agricultural Products Quality Detection Technology Based On Terahertz

Terahertz technology is a hot technology in the field of cutting-edge technology,bringing creative development to industrial development,agricultural testing and national defense.In this paper,the plant growth regulators contained in crops and crops are studied.The main contents are as follows:(1)The terahertz time-domain spectra of plant growth regulators including gibberellic acid(GA3),thidiazuron and forchlorfenuron are obtained.It is verified that different samples have different absorption characteristics for terahertz waves.Corresponding parameters of the corresponding samples are obtained by calculation,such as absorption coefficient,refractive index,etc.Through the relevant software simulation experiments,combined with the actual experimental results and the molecular structure of the substance itself,the causes of the absorption peaks of plant growth regulators under terahertz radiation are analyzed.(2)The classification characteristics of 18 kinds of pure substances including plant growth regulators,pure medicines,flour and other powdery substances are studied.Support vector machine and BP neural network based on genetic algorithm are used to classify these 18 substances.In addition,three algorithms are used to optimize the parameters of the support vector machine model,and the efficiency and robustness of the three methods are compared.(3)A two-dimensional mobile platform is built to assist the sample to move and image in a two-dimensional plane.A software system is developed for image preprocessing of terahertz-based imaging.The condition of the fruit inside the crop with the outer shell,such as the degree of fullness and growth,is analyzed by imaging.(4)The feasibility of terahertz technology for imaging samples is studied.Firstly,the absorption degree of terahertz waves by the tested crops is detected,and the imaging method of spectral peak transformation in the time domain and the imaging method based on specific frequency are used to image the samples.The differences between the two imaging methods and their respective advantages and disadvantages are compared.Based on the acquired image,the condition of the fruit inside the crop is analyzed,which provides a new way for the non-destructive detection of crops with shells such as nut crops and grains.