A non-destructive detection system for Conopomorpha sinensis Bradley, comprising a visible/near-infrared non-destructive detection platform, an X-ray imaging detection platform, a power supply platform, a conveyor device, and an information processing device;
- wherein the visible/near-infrared non-destructive detection platform is used to acquire internal quality features of the lychee sample;
- the X-ray imaging detection platform is used to acquire internal density variation features of the lychee sample;
- the power supply platform is used to supply power to all devices and platforms in the non-destructive detection system;
- the information processing device is used to perform data processing and analysis based on PLSR and a support vector machine on feature information acquired in the non-destructive detection system to acquire a detection result of the lychee sample with and without insects;
- the conveyor device is compatible with the visible/near-infrared non-destructive detection platform and the X-ray imaging detection platform, and is used to convey the lychee sample to be detected to a preset detection platform for detection;
- the information processing device implements feature fusion process on a received quality image representing the internal quality features of the lychee sample and a density variation image representing the internal density variation features of the lychee sample based on a carried data analysis and processing program, and further improves a detection accuracy in combination with PLSR and a support vector regression;
- the feature fusion process on the received quality image representing the internal quality features of the lychee sample and the density variation image representing the internal density variation features of the lychee sample comprises the following steps:
- extracting average grayscale values of a stem, a core, and flesh in the density variation image of the lychee sample with the best classification and prediction effect, and combining the average grayscale values with feature bands of visible/near-infrared transmission spectrum extracted using the continuous projection method to form a comprehensive analysis of multi-source information;
- the improves the detection accuracy in combination with PLSR comprises:
- preliminarily determining a classification of the lychee sample with and without insects using PCA, which is represented by a sample scatter plot formed by a first principal component and a second principal component;
- dividing spectral data after feature extraction into a training set and a testing set and establishing a discrimination model using PLSR, wherein a detection result of the lychee sample without insects is set to be 0 and the detection result of the lychee sample with insects is set to 1, a detection effect of a PLSR model is greatly affected by a number of the selected features after dimensional reduction, and the detection result is outputted as a decimal number, which is usually represented by a coefficient of determination R2 between a predicted value and an actual value, as well as a root mean square error;
- the improves the detection accuracy in combination with the support vector regression comprises:
- dividing a training set and a testing set and establishing a prediction model using SVR, wherein a prediction result of the lychee sample without insects is set to be 0 and the prediction result of the lychee sample with insects is set to be 1, and rounding the results of the PLSR model and a SVR model to a nearest integer, wherein when the integer is less than or equal to 0, it indicates the lychee sample does not have insects;
- when the integer is greater than or equal to 1, it indicates the lychee sample has insects.