New method for constructing wheat moisture microwave transmission model based on COMSOL

Abstract

The invention relates to a new method for constructing a wheat moisture microwave transmission model based on COMSOL. The method comprises the steps: building a 3D simulation model, adding material attributes, adding an electromagnetic wave source field, carrying out mesh generation of the 3D simulation model, defining a frequency range, calculating the 3D simulation model and obtaining a frequency-S parameter one-dimensional curve graph; changing the water content of the wheat, observing a frequency-S parameter curve of the changed water content and recording change rules; forming rules between the wheat water content and the frequency-S parameter curve; and measuring the frequency-S parameter curve of to-be-measured wheat to determine the water content of the to-be-measured wheat. On thepremise that the wheat state is not damaged, a microwave detection method is adopted to explore the rules between the wheat water content and the frequency-S parameter curve of microwaves, and thus the accuracy of wheat water content measurement is improved; and meanwhile, a water content database can be quickly constructed based on different wheat water contents with different characteristic parameters, thereby promoting formulation of water standard in the wheat industry.

Description

technical field [0001] The invention relates to a new 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 ...

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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