Construction method of microwave transmission model of wheat moisture based on comsol

Abstract

The invention relates to a method for constructing a COMSOL-based microwave transmission model of wheat moisture. The method includes establishing a 3D simulation model, adding material attributes, adding an electromagnetic wave source field, dividing the grid of the 3D simulation model, defining a frequency range, and calculating the 3D simulation model. And obtain the frequency-S parameter one-dimensional graph; Change the water content of wheat, observe the frequency-S parameter curve of moisture content after changing, record its change law; Form the law between the wheat water content and the frequency-S parameter curve; Measure the frequency-S parameter curve of the wheat to be measured, so as to determine the moisture content of the wheat to be measured; under the premise of not destroying the state of the wheat, the present invention uses a microwave detection method to explore the relationship between the moisture content of wheat and the frequency-S parameter curve of microwave The law can improve the accuracy of wheat moisture content measurement; at the same time, it can quickly build its moisture content database for different grain moisture content of different characteristic parameters, thereby promoting the formulation of grain moisture standards in the grain industry.

Description

technical field [0001] The invention relates to a method for constructing a microwave transmission model of wheat moisture based on COMSOL. Background technique [0002] Grain moisture content is an important quality index of grain storage safety, timely grasping of grain moisture content can prevent grain mildew caused by excessive moisture content. The traditional methods of grain moisture detection mainly include capacitance method, resistance method and near-infrared method. Capacitance measurement has low cost and simple structure. The disadvantage is that it is greatly affected by the variety, temperature, and density of grain, and the measurement accuracy is low and the stability is poor. The resistance method grain moisture measuring instrument is cheap and simple in structure; the disadvantage is that the sampling requirements are high, the signal strength is low, the contact state of the sensor and the grain will affect the measurement accuracy, and it is not suit...

AI Technical Summary

Problems solved by technology

Capacitance measurement has low cost and simple structure. The disadvantage is that it is greatly affected by the variety, temperature, and density of grain, and the measurement accuracy is low and the stability is poor.

The resistance method grain moisture measuring instrument is cheap and simple in structure; the disadvantage is that the sampling requirements are high, the signal strength is low, and the contact state between the sensor and the grain will affect the measurement accuracy. It is not suitable for the determination of micro-water content and high water content.

The near-infrared method is a non-contact measurement without pretreatment, fast measurement speed and wide application range; the disadvantage is that factors such as grain shape, density and ambient temperature will affect the measurement results

Compared with traditional detection methods, microwave detection methods are less sensitive to the environment, have strong penetrating ability, are non-invasive, have no damage to the detection objects, and can detect continuously and rapidly online; however, microwave detection methods have not been widely used in food Moisture content detection

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