Design Of Potato Sorting And High Voltage Pulsed Electric Field Treatment

In recent years,with the proposal of potatoes as the fourth staple food strategy,the domestic potato processing industry has been promoted.In the preprocessing process before potato cutting,it has been proven that high-voltage pulsed electric field(PEF)treatment can reduce cutting loss,reduce the oil content after frying,and improve product taste.Based on this,Thesis designed a set of potato sorting and high-voltage pulse processing system.The main research work and innovation points are as follows:(1)In order to obtain clear,accurate,and complete potato surface images,Thesis designed a scheme for collecting images through a three camera system and made a selection for the image acquisition unit.In order to improve the accuracy of potato sorting,a potato deep learning sorting model based on attention mechanism was designed.After training and parameter tuning,the sorting accuracy of this model reached as high as 98.64%.(2)In order to design a high-voltage pulse generator more suitable for Thesis,five commonly used types of high-voltage pulse generators were compared,and a solid-state switch-type highvoltage pulse generator with a wider adjustable range of pulse width and frequency and a stronger load capacity was selected.In response to the problem of large volume,low efficiency,and poor stability of commonly used high-voltage DC power supplies,a set of high-voltage DC stabilizing power supplies using Buck circuits to control the output voltage were designed.After studying various pulse waveforms,it was found that bipolar pulse square wave processing was more suitable for Thesis.Improvements were made to the traditional solid-state switch-type high-voltage pulse generator circuit to achieve bipolar square wave output.Through Simulink circuit simulation,the feasibility of the high-voltage power supply and generator were demonstrated.In order to realize the potato PEF pipeline processing,a flat plate electric level processing chamber with flexible and convenient installation was designed.(3)In response to the control of high-voltage DC stabilizing power supply,a power control board with STM32F103ZET6 as the core controller was designed.In response to other PEF processing equipment control requirements and to obtain nanosecond-level pulses,a PEF equipment control board with STM32F103ZET6+FPGA as the core controller was designed.The hardware design including the lower machine power supply,detection,communication,signal acquisition and other modules was completed.Combined with the control requirements of highvoltage pulse processing and the requirements for later program maintenance,lower machine software programs were written,including the communication protocol between the lower machine and the central control machine,IAP firmware remote upgrade design,power control board main program design,PEF equipment control board program design,and FPGA software(i.e.highvoltage pulse generator control program)design.(4)In order to facilitate on-site operation,Thesis used XA070LAI15 central control touch screen as the on-site human-machine interaction equipment and completed the writing of the application software APP.In order to realize remote monitoring of the equipment,Thesis built an LNMP architecture server,uploaded on-site information through the central control touch screen,put it into the corresponding database form,and used HBuilder software to write the monitoring webpage of the PEF processing system to achieve real-time display.In order to facilitate remote program upgrades,Net Assist was chosen as the PC-side upgrade tool,and relevant upgrade protocols were formulated.The potato sorting and high-voltage pulse processing system designed in Thesis can effectively and accurately sort potatoes and perform high-voltage pulse processing on the sorted potatoes,improving the quality of potato products and reducing production costs.