| China is the country with the highest rice production in the world,and rice is also my country’s largest food crop.The accurate determination of the moisture content of rice is an important factor for the safe storage of rice after harvest.In order to improve the degree of agricultural intelligence and the accuracy of online detection of rice moisture content,the parallel plate capacitive on-line detection device for rice moisture content was optimized based on the variation of the dielectric properties of rice moisture content.The main work of this article includes the following four aspects:(1)In this paper,the parallel plate capacitive on-line detection device for moisture content of rice is taken as the research object,and the two-dimensional electric field analysis is carried out with the Comsol finite element analysis software for the relationship between the capacitance pole structure and the edge effect.Using Design Expert,the Box-Behnken design experiment with response surface optimization was adopted to determine the influence of the thickness,distance and relative area of the plate on the edge effect,and the plate structure with the lowest edge effect was obtained.(2)The mechanical structure of the device has been optimized.Designed a dual-polar plate detection structure and a pull-type grain discharge mechanism.The MCF51AC125 chip with high integration is selected to design the measuring circuit,and the monitoring system of the host computer is used to realize the functions of real-time collection of rice moisture content data.(3)Establish a rice water content NARX prediction model.The optimization algorithm,the number of neurons,and the lag order of the model are compared and analyzed,and the optimal structural parameters of the model are selected.The prediction model of moisture content is trained,and the error range of water content prediction is obtained.(4)Carry on the laboratory static moisture content test and the rice drying field on-line test.Compared with the results of 105℃ constant weight method,the stability and accuracy of the on-line measuring device for water content of parallel plate capacitive rice were verified. |
