Research Of Grain Inspection Based On Diffuse Reflectance Near-Infrared Spectroscopy

In the thesis, the development and application of the near infrared spectroscopy technology and instrumentation are introduced, the basic principles of the near-infrared absorption spectra is studied.Based on the theory of the near infrared absorption spectra ,a hardware test platform is set and a diffuse reflectance spectra collection system using integrating sphere has been designed. 40 representative wheat samples were tested. Many kinds of spectral data preprocessing method have been analyzed. The pretreatment of the experimental data has been made with the image enhancement algorithm, smoothing algorithm, multiplicative scatter correction, the trend algorithms, wavelet transform or orthogonal signal correction etc.The modeling methods and modeling strategies have been briefly analyzed. original spectral data, the spectral data processed by the method of the wavelet smoothing seeking second derivative, the spectral data processed by the method of the multiplicative scatter correction post-processing and the spectral data processed by the method of the standard normal variate correction, are modeled with PLS. And compared to each other.