Design Of Tobacco Leaf Drying Control System Based On Image Processing

At present,the intensive tobacco barn,which is popular in China,has problems such as large temperature control error and low quality of flue-cured tobacco products.The main reasons include the low level of automation of the temperature and humidity control system in the baking room and the excessive dependence on the baking process.Manual regulation,low system integration,etc.An automatic control system that automatically determines the state of tobacco leaves and adjusts the subsequent baking process based on the eigenvalue information of the real-time flue-cured tobacco image is proposed in this thesis.The main content of this thesis can be divided into three parts,namely: collection and processing of flue-cured tobacco images,research on temperature and humidity control algorithm of tobacco roasting room,and hardware design of temperature and humidity control system.Collection and processing of flue-cured tobacco image: The hardware equipment model of the image acquisition system according to the real environment and actual needs inside the baking room,and completes the construction of the image acquisition system selected by this design;Based on the Opencv platform,the real-time image processing program of tobacco leaves was designed,which realized the separation of the image of mesophyll and vein area,the extraction of image feature values and the drawing of eigenvalue curves.Research on temperature and humidity control algorithm of tobacco barn baking room: The traditional PID control algorithm is not ideal for temperature control of dense barn system.The use of fuzzy adaptive by analyzing the physical characteristics of the barn system and the main reasons for unsatisfactory control proposed in this thesis.PID control is used as the temperature control algorithm for the barn system.The two models are compared with the simulation model In the Simulink.The simulation results verify the superiority of the fuzzy adaptive PID control algorithm in the temperature control of the baking room.Hardware design of temperature and humidity control system: Considering the main functions and actual needs of the baking room control system,this design selects and optimizes the hardware part of the temperature and humidity control system.Among them: the Siemens S7-200 series PLC is selected as the main controller of the baking room control system;the PT-100 temperature sensor and the EM235 expansion module are selected as the temperature and humidity measurement and signal conversion equipment of the control system;A new air energy heat pump is selected as the heat source for the baking room system.Finally,the human-computer interaction software of the upper computer is designed to realize the real-time information display and monitoring inside the barn,the modification of the target parameters of the barn and the automatic alarm,etc.which comprehensively improves the automation and integration level of the barn control system.