Research And Development Of Handheld Fluorescence Imaging System For Food Residue Detection

Foodborne disease is an important problem in the field of food safety.Food production and processing equipment in the process of work will produce debris residues,which will affect the quality of subsequent food production and easy to breed food-borne bacteria.At present,the health inspection of food production and processing sites in China is still mainly based on visual inspection.Visual inspection is easily disturbed by the environment and inspector fatigue,and the detection effect is unstable.However,for some transparent or similar background color residues,visual inspection is difficult to achieve better detection results,so it is necessary to develop a rapid detection equipment to improve the surface cleanliness and hygiene inspection ability of food processing equipment.This study deeply analyzes the shortcomings of traditional cleaning and hygiene detection methods.A handheld fluorescence imaging detection system for food residue is designed by combining fluorescence spectral imaging technology and embedded technology to solve the problems of unstable detection effect and high detection cost of traditional detection methods.The practicability of the designed system is verified by the test results of the simulated processing equipment surface system.The research content and development of this paper are as follows:1.According to the deficiencies of the current surface cleanliness and hygiene detection methods of food processing equipment,combined with the research of fluorescence imaging technology in the field of surface cleaning and verification of food processing equipment,the functional requirements of the handheld fluorescence imaging detection system for food residue are proposed.The hardware architecture design,software architecture design and main functional device selection of the handheld food residue fluorescence imaging detection system are completed according to the functional requirements.In the hardware architecture,according to the system functions,the handheld food residue detection system is divided into four modules: excitation light source module,signal acquisition module,display module and power module,and the selection of main functional devices is completed according to the functions of each module.In the software architecture,according to the characteristics of FPGA SOPC system,the software structure is divided into interaction layer and application layer.The human-computer interaction logic design is realized in the interaction layer,and the underlying device driver is realized in the application layer.2.The hardware design of the handheld food residue fluorescence imaging detection system and the three-dimensional modeling of the system shell were completed.According to the system hardware architecture,the embedded main control board,the excitation light source driver board,the TFT display module backplane and camera acquisition module are designed respectively in the system schematic.There are 233 electronic components in the system schematic,including a high-performance BGA package FPGA chip,a high-speed synchronous dynamic random access memory,a piece of external Flash,7 different sizes of power supply voltage and 8 power supplies.In the PCB design of the system,the multi-layer PCB circuit board layout is optimized from signal integrity and power integrity,which improves system stability and anti-interference performance.In the 3D modeling of the system shell,3D modeling software is used to design the system shell and 3D printing technology is used to produce the system shell.3.The driving logic design,image processing algorithm design and human-computer interaction design of handheld food residue fluorescence imaging detection system were completed.Make full use of FPGA hardware programmable ability,Verilog HDL is used to complete the development of camera,RGB touch screen,ultrasonic ranging and other peripheral drivers.Taking advantage of FPGA parallel pipeline,Verilog HDL is used to realize the hardware implementation of image processing algorithm.Taking advantage of FPGA SOPC,Qsys system is built with embedded soft-core NIOS II processor,and the human-computer interaction is designed by using the advantages of C language and image user interface u CGUI.4.According to the system hardware debugging and testing specifications,the system hardware function,software and logic function,and system performance are tested.The hardware circuit function of the system was verified by the test instrument,the correctness of the logic code timing sequence was verified by the embedded logic analyzer,the performance test was carried out on the surface of the simulated processing equipment to verify the humancomputer interaction function of the system and the detection ability of food residues.In summary,the design of handheld food residue detection system described in this paper includes hardware circuit design,driving logic design,FPGA accelerated image processing algorithm,human-computer interaction interface design.Through the hardware circuit and shell designed by ourselves,the volume of the equipment is reduced and the convenience of the equipment is improved.By integrating light source control,ultrasonic ranging,data backup and management,the system is more perfect and convenient in function and operation.By implementing gray transform,median filtering algorithm and block Otsu algorithm in FPGA,the detection speed and effect of the device are improved.The system has the functions of fluorescence image acquisition,image processing,image display and image saving,and can save the detected residue image in the SD card in real time.The system test shows that the system can effectively improve the surface food residue detection ability of processing equipment,and can be applied to verify the surface cleanliness of food production and processing equipment and guide the improvement of cleaning process.