Research On Pig Carcass Detection System Based On Near Infrared Spectroscopy Analysis Technology

China has the largest pork consumer market in the world.With the improvement of people's living standard,consumers are putting forward higher standards for pork quality.Therefore,research and development of an efficient pork carcass grading detection system has practical significance for the development of pork industry.Near Infrared Spectroscopy(NIRS)is increasingly used because of its high efficiency.After analyzing the current situation and trend of pork carcass grading at home and abroad,this paper combines with the optical system,NIR signal acquisition and processing system,and the spectral acquisition software,a design of pork lean meat rate detection system is proposed.Based on the asymmetric Czerny-Turner structure,the optical system is designed.The light source,Y-type fiber and grating in the optical system were selected,and the selection principle and characteristic parameters of CCD detector were studied.The optical system was built to receive diffuse reflection optical signals and output electrical signals containing meat characteristics.This paper presents a design scheme of hardware system for NIRS signal acquisition and processing.It analyses the working sequence of the CCD,A/D conversion and transmission,and selects FPGA to provide timing sequence to ensure the normal operation.Then the design of signal conditioning is proposed to realize noise suppression between circuits,and finally through the serial port configuration to complete the signal communication.After analyzing the functional requirements and software flow,the software of pork carcass reflectance spectrum data acquisition is designed.The background noise,the light amplitude of the whiteboard and the light amplitude of the sample are collected.The sample reflectance is calculated accurately and the near-infrared reflectance spectra containing meat information are displayed.Finally,an experimental platform is built and a series of pork carcass fat and lean reflection spectral characteristics analysis experiments are designed.The factors such as thickness of pork,irradiation height of light source and freshness of the sample are analyzed.The final experimental results meet the needs of development of pork carcass grading equipment in the future.