CN107219239A - Microwave measurement for moisture content method, device, equipment and storage medium - Google Patents

Abstract

A microwave moisture measurement method, device, equipment, and storage medium. The method in one example includes the steps of: acquiring material type information; extracting a predetermined number of Frequency information; control the microwave transmitting antenna to sequentially transmit microwave signals of frequencies corresponding to the predetermined number of frequency information; obtain microwave signals received by the microwave receiving antenna; determine the microwave signals of each frequency received by the microwave receiving antenna relative to the microwave transmitting antenna The phase difference and damping attenuation of the microwave signals of each frequency; the phase difference of the microwave signals of each frequency is the first vector, and the damping attenuation is the second vector, and the superposition of the first vector and the second vector is obtained respectively. The microwave signal vector of the microwave signal; the water content of the material to be tested is determined according to the microwave signal vector of the microwave signal of each frequency. The scheme of this embodiment improves the accuracy of microwave moisture measurement.

Description

Microwave moisture measurement method, device, equipment and storage medium

technical field

The invention relates to the technical field of moisture measurement, in particular to a microwave moisture measurement method, device, equipment and storage medium.

Background technique

Microwave moisture measurement technology is more and more commonly used in various industries. It can monitor the moisture content of materials in the production process in order to improve product quality and effectively control the production process, thereby saving costs and improving production efficiency and production benefits.

The basic principle of microwave moisture measurement is: the microwave emitted by the transmitting antenna penetrates the material under test and reaches the receiving antenna, and the microwave received by the receiving antenna is fed back to the evaluator, and the evaluator analyzes the moisture content of the material under test. When the microwave penetrates the material, since the water molecule in the material is a polar molecule, it will absorb the microwave, generate vibration of the key foot, and convert the electromagnetic energy into heat energy, resulting in a difference in the phase of the microwave and an attenuation of the amplitude. The amount can calculate the moisture content in the material.

The current microwave measurement method is inevitably affected by changes in the density of the material. When the density of the measured material in a certain volume changes, the microwave moisture meter cannot accurately reflect the true moisture content of the measured material. For example: when a certain volume of 6 kg of cotton bales M with 6% water content passes through the microwave moisture meter, the microwave moisture meter responds that the material contains 6% water; The moisture meter considers the cotton bale M to be 12% water. This is because the weight and density of the cotton bale M increase, and the moisture content per unit volume increases, but in fact the real moisture content of the cotton bale M is still 6%, and the weight and density of the material in the actual production cannot be kept strictly consistent , thus resulting in inaccurate final measured water content.

Contents of the invention

Based on this, the purpose of the embodiments of the present invention is to provide a microwave moisture measurement method, a microwave moisture measurement device, a device and a storage medium, so as to improve the accuracy of microwave moisture measurement.

In order to achieve the above purpose, the embodiment of the present invention adopts the following technical solutions:

A microwave moisture measurement method, comprising steps:

Get material type information;

Extracting a predetermined number of frequency information from frequency intervals corresponding to the material type information according to the material type information;

controlling the microwave transmitting antenna to sequentially transmit microwave signals of frequencies corresponding to the predetermined number of frequency information;

Obtain the microwave signal received by the microwave receiving antenna;

Determine the phase difference and damping attenuation of the microwave signals of each frequency received by the microwave receiving antenna relative to the microwave signals of each frequency emitted by the microwave transmitting antenna;

Taking the phase difference of the microwave signals of each frequency as the first vector and the damping attenuation as the second vector, superimposing the first vector and the second vector to obtain microwave signal vectors of the microwave signals of each frequency respectively;

The water content of the material to be tested is determined according to the microwave signal vector of the microwave signal of each frequency.

A microwave moisture measuring device, comprising:

A type determination module, configured to obtain material type information; a frequency information determination module, configured to extract a predetermined number of frequency information from frequency intervals corresponding to the material type information according to the material type information;

The microwave irradiation control module is used to control the microwave transmitting antenna to sequentially transmit microwave signals of frequencies corresponding to the predetermined number of frequency information, and obtain microwave signals received by the microwave receiving antenna;

The vector determination module is used to determine the phase difference and damping attenuation of the microwave signals of each frequency received by the microwave receiving antenna relative to the microwave signals of each frequency emitted by the microwave transmitting antenna; and the phase difference of the microwave signals of each frequency is the first The first vector and the damping attenuation are the second vector, and the microwave signal vectors of the microwave signals of each frequency are respectively obtained by superimposing the first vector and the second vector;

The water content determination module is used to determine the water content of the material to be tested according to the microwave signal vector of the microwave signal of each frequency.

An apparatus comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, the processor implementing the method as described above when executing the computer program.

A computer storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the above method are realized.

According to the solution of the above-mentioned embodiment, when performing microwave moisture measurement, based on the received material type selection instruction, the frequency information is extracted from the frequency interval corresponding to the material type information in the material type selection instruction, and the extracted It is a predetermined number of frequency information, and then control the microwave transmitting antenna to transmit microwave signals corresponding to the extracted predetermined number of frequency information, so as to realize the measurement of water content based on a predetermined number of received microwave signals and corresponding transmitted microwave signals , and when determining the water content, the water content is determined based on the microwave signal vector determined based on the received microwave signal and the transmitted microwave signal, so that it transmits microwaves based on a plurality of frequencies in the frequency interval corresponding to the type of the material to be measured, and The moisture content is determined according to the microwave signal vector determined by the phase difference and the damping attenuation determined based on the microwave signal, thereby improving the accuracy of the microwave moisture measurement.

Description of drawings

Figure 1 is a schematic diagram of the structure and principle of microwave moisture measurement in an application example;

Fig. 2 is a schematic flow sheet of the microwave moisture measuring method in an embodiment;

Fig. 3 is a schematic structural diagram of a microwave moisture measuring device in one embodiment.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, and do not limit the protection scope of the present invention.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field of the invention. The terms used herein in the description of the present invention are for the purpose of describing specific embodiments only, and are not intended to limit the present invention. As used herein, the term "or/and" includes any and all combinations of one or more of the associated listed items.

FIG. 1 shows a schematic diagram of the structure and principle of microwave moisture measurement in an application example. As shown in FIG. 1 , a microwave moisture measuring instrument for microwave moisture measurement includes an evaluator 100 , a transmitting antenna 200 and a receiving antenna 300 . The transmitting antenna 200 and the receiving antenna 300 can be communicated with the evaluator 100 through a high-frequency transmission line or the like. The evaluation instrument 100 includes a frequency controller and a processor, and the frequency controller may specifically include a quartz crystal oscillator, a low-noise phase-locked loop frequency converter, a mixer, an attenuator, a modulator, a radio frequency amplifier, a differential amplifier, a filter, a logarithmic amplifier and phase difference comparator.

When performing microwave moisture measurement, the frequency controller generates a microwave signal of a specified frequency based on the control of the processor. The microwave signal is transmitted through the transmitting antenna 200. The transmitted microwave signal will penetrate the measured material on the non-metallic conveyor belt and reach the receiving antenna 300 . The microwave signal received by the receiving antenna 300 is transmitted to the evaluator 100 , and the evaluator 100 calculates the moisture content of the material under test based on the microwave signal received by the receiving antenna 300 and the microwave signal emitted by the transmitting antenna 200 .

FIG. 2 shows a schematic flowchart of a microwave moisture measurement method in an example, which can be applied to the evaluator shown in FIG. 1 . As shown in Figure 2, the microwave moisture measurement methods in this example include:

Step S201: Obtain material type information;

Step S202: According to the material type information, extract a predetermined number of frequency information from the frequency range corresponding to the material type information;

Step S203: controlling the microwave transmitting antenna to sequentially transmit microwave signals of frequencies corresponding to a predetermined number of frequency information;

Step S204: Obtain the microwave signal received by the microwave receiving antenna;

Step S205: Determine the phase difference and damping attenuation of the microwave signals of each frequency received by the microwave receiving antenna relative to the microwave signals of each frequency transmitted by the microwave transmitting antenna;

Step S206: taking the phase difference of the microwave signal at each frequency as the first vector and the damping attenuation as the second vector, and superimposing the first vector and the second vector to obtain the microwave signal vectors of the microwave signals at each frequency;

Step S207: Determine the moisture content of the material to be tested according to the microwave signal vectors of the microwave signals of each frequency.

According to the solution of the above-mentioned embodiment, when performing microwave moisture measurement, based on the received material type selection instruction, the frequency information is extracted from the frequency interval corresponding to the material type information in the material type selection instruction, and the extracted It is a predetermined number of frequency information, and then control the microwave transmitting antenna to transmit microwave signals corresponding to the extracted predetermined number of frequency information, so as to realize the measurement of water content based on a predetermined number of received microwave signals and corresponding transmitted microwave signals , and when determining the water content, the water content is determined based on the microwave signal vector determined based on the received microwave signal and the transmitted microwave signal, so that it transmits microwaves based on a plurality of frequencies in the frequency interval corresponding to the type of the material to be measured, and The moisture content is determined according to the microwave signal vector determined by the phase difference and the damping attenuation determined based on the microwave signal, thereby improving the accuracy of the microwave moisture measurement.

In an example, when determining the moisture content of the material to be tested according to the microwave signal vector of the microwave signal of each frequency, the method in a specific example may include:

Determine the included angle of the microwave signal vector of the microwave signal of each frequency;

Constructing a vector matrix comprising angles of each microwave signal vector;

The moisture content of the material to be tested is determined according to the vector matrix.

In a specific application example, the moisture content of the material to be tested can be determined according to the vector matrix and the preset determined regression coefficient matrix.

Based on the scheme in this example, a detailed example will be given below in conjunction with the process of measuring moisture by microwave measurement in an application example.

As mentioned above, when moisture is measured by microwave, the moisture content of the material to be measured is calculated based on the microwave signal received by the receiving antenna and the microwave signal emitted by the transmitting antenna. When microwave measures moisture, it mainly uses the dielectric properties of moisture, and the dielectric constant can be expressed as:

εr=ε′r-j(ε″r+o’/ωε0)

Among them, ε″r is the dielectric loss, o’/ωε0 is the conductive loss, and ω is proportional to the microwave frequency.

At low frequencies, the conductive loss dominates, and the relationship between microwave attenuation and water content is not obvious; while at high frequencies, dielectric loss dominates, and there is an obvious linear relationship between microwave attenuation and water content. Therefore, in order to determine the accuracy of the measured water content of the material to be tested, in this embodiment, a frequency band suitable for the material to be tested (that is, a frequency band with an obvious linear relationship between microwave attenuation and water content) is selected for measurement.

In the solution of the embodiment, firstly, the type of the material to be tested is determined, that is, the material type information is determined, and any possible way may be used to determine the material type information. The method in one embodiment may be that the user sends a material type selection instruction through a set selection switch, a touch screen and other similar equipment, and the material type selection instruction includes the material type information of the material to be tested. The type selection command obtains the material type information. In some embodiments, it is also possible to automatically identify the type of the material to be tested, so as to obtain the above-mentioned material type information.

According to the solution of the embodiment of the present invention, after the material type information is obtained, a predetermined number of frequency information is extracted from the frequency range corresponding to the material type information. The predetermined number here can be set according to actual needs, for example, it can be set to 100. The frequency range of the microwave signal is generally a wide frequency range. The frequency range in this example can be set to 500 MHz to 10 GHz. For different types of materials, the frequency intervals in the frequency range corresponding to each material (ie, material type information) may or may not be the same.

Subsequently, the microwave transmitting antenna is controlled to sequentially transmit microwave signals of frequencies corresponding to the predetermined number of frequency information, that is, the microwave signals of 100 different frequencies are controlled to be transmitted, and the 100 microwave signals of different frequencies can be transmitted sequentially within a predetermined time period. The predetermined time limit may be set according to actual needs, and may be set to 10 milliseconds in an example.

After the microwave signal of each frequency is emitted by the transmitting antenna, it penetrates the measured material on the non-metallic conveyor belt and reaches the receiving antenna. After the microwave signal received by the receiving antenna is obtained, the phase difference and damping attenuation of the microwave signal of this frequency can be determined according to the microwave signal received by the receiving antenna and the microwave signal received by the transmitting antenna. A specific manner of determining the phase difference and the damping attenuation may be performed in any possible manner.

The phase difference between the received and transmitted microwave signals at this frequency is used as a vector, which is recorded as the first vector, and the damping attenuation is also used as a vector, which is recorded as the second vector. The microwave signal vector of the microwave signal of the frequency can be obtained by superimposing the first vector and the second vector.

By analyzing the microwave signal vector and expressing the microwave signal vector as a vector in the coordinate system, it can be determined that the microwave signal vector is a quantity that has nothing to do with density changes but is related to moisture changes. As long as the water content is constant, the angle of the microwave signal vector in the coordinate system will not change, regardless of the water content.

Taking the above-mentioned microwave signals with 100 frequencies as an example, for the above-mentioned microwave signals with 100 frequencies, 100 microwave signal vectors can be obtained. After determining the angles of these 100 signal vectors in the coordinate system, use The included angles represented by these 100 signal vectors construct a vector matrix, and then, the moisture content of the measured material can be determined according to the vector matrix and the preset regression coefficient matrix.

In specific applications, the moisture content of the material to be tested can be determined based on the following formula:

In the formula, C is the water content (%), b ₀ is the regression intercept (preset constant), bi is the regression coefficient matrix, Ai is the above-mentioned vector matrix, and _n is the frequency number. For example, taking the above-mentioned transmitted signal transmitted at 100 frequencies as an example, both b _i and Ai are matrices with 1 row and 100 columns, and n is equal to 100.

Wherein, the regression coefficient matrix can be predetermined and stored, and can be directly used when determining the water content. In a specific application example, the above b _i may be determined by establishing a calibration model and using a partial least squares algorithm. A specific manner of determining the regression coefficient matrix may be performed in any possible manner based on the water content of a plurality of known samples.

Based on the same idea as the above method, Fig. 3 shows a schematic structural diagram of a microwave moisture measuring device in an example. As shown in Fig. 3, the microwave moisture measuring device in this example includes:

A type determining module 301, configured to acquire material type information;

The frequency information determination module 302 is used to extract a predetermined number of frequency information from the frequency interval corresponding to the material type information according to the material type information; the predetermined number can be set in combination with actual needs, and in an example can be set is 100; the frequency interval in an example may be in the range of 500MHz to 10GHz;

The microwave irradiation control module 303 is used to control the microwave transmitting antenna to sequentially transmit microwave signals corresponding to the predetermined number of frequency information, and obtain the microwave signals received by the microwave receiving antenna; in one example, the microwave irradiation control module 303 can control the microwave The transmitting antenna sequentially transmits microwave signals of frequencies corresponding to a predetermined number of frequency information within a predetermined time period, and the predetermined time period can be set according to actual needs, for example, it can be set to 10 milliseconds;

The vector determination module 304 is used to determine the phase difference and damping attenuation of the microwave signal of each frequency received by the microwave receiving antenna relative to the microwave signal of each frequency emitted by the microwave transmitting antenna; and the phase difference of the microwave signal of each frequency is The first vector and the damping attenuation are the second vector, and the microwave signal vectors of the microwave signals of each frequency are respectively obtained by superimposing the first vector and the second vector;

The moisture content determination module 305 is configured to determine the moisture content of the material to be tested according to the microwave signal vectors of the microwave signals of various frequencies.

According to the solution of the above-mentioned embodiment, when performing microwave moisture measurement, based on the received material type selection instruction, the frequency information is extracted from the frequency interval corresponding to the material type information in the material type selection instruction, and the extracted It is a predetermined number of frequency information, and then control the microwave transmitting antenna to transmit microwave signals corresponding to the extracted predetermined number of frequency information, so as to realize the measurement of water content based on a predetermined number of received microwave signals and corresponding transmitted microwave signals , and when determining the water content, the water content is determined based on the microwave signal vector determined based on the received microwave signal and the transmitted microwave signal, so that it transmits microwaves based on a plurality of frequencies in the frequency interval corresponding to the type of the material to be measured, and The moisture content is determined according to the microwave signal vector determined by the phase difference and the damping attenuation determined based on the microwave signal, thereby improving the accuracy of the microwave moisture measurement.

The moisture content determination module 305 in one example includes:

An included angle determination module is used to determine the included angle of the microwave signal vector of the microwave signal of each frequency;

A matrix construction module is used to construct a vector matrix comprising angles of each microwave signal vector;

A determining module, configured to determine the water content of the material to be tested according to the vector matrix.

In a specific application example, the determining module may determine the moisture content of the material to be tested according to the vector matrix and the preset determined regression coefficient matrix.

Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be implemented through computer programs to instruct related hardware, and the programs can be stored in a non-volatile computer-readable storage medium. As in the embodiment of the present invention, the program may be stored in a storage medium of a computer system, and executed by at least one processor in the computer system, so as to implement the procedures including the embodiments of the above-mentioned methods. Wherein, the storage medium may be a magnetic disk, an optical disk, a read-only memory (Read-Only Memory, ROM) or a random access memory (Random Access Memory, RAM), and the like.

Based on the above example, an embodiment further provides a storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the microwave moisture measurement method as above is implemented.

In addition, in one embodiment, a device is also provided, which may be any possible device form of the aforementioned evaluator, which includes a memory, a processor, and a computer program stored in the memory and operable on the processor, so that When the processor executes the program, the microwave moisture measurement method of any example above is realized.

The technical features of the above-mentioned embodiments can be combined arbitrarily. To make the description concise, all possible combinations of the technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, should be considered as within the scope of this specification.

The above-mentioned embodiments only express several implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but should not be construed as limiting the patent scope of the invention. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (10)

1. A microwave moisture measurement method, is characterized in that, comprises steps: Get material type information; Extracting a predetermined number of frequency information from frequency intervals corresponding to the material type information according to the material type information; controlling the microwave transmitting antenna to sequentially transmit microwave signals of frequencies corresponding to the predetermined number of frequency information; Obtain the microwave signal received by the microwave receiving antenna; Determine the phase difference and damping attenuation of the microwave signals of each frequency received by the microwave receiving antenna relative to the microwave signals of each frequency emitted by the microwave transmitting antenna; Taking the phase difference of the microwave signals of each frequency as the first vector and the damping attenuation as the second vector, superimposing the first vector and the second vector to obtain microwave signal vectors of the microwave signals of each frequency respectively; The water content of the material to be tested is determined according to the microwave signal vector of the microwave signal of each frequency. 2. microwave moisture measuring method according to claim 1, is characterized in that, according to the microwave signal vector of the microwave signal of each frequency, the mode that determines the moisture content of described material to be measured comprises: Determine the included angle of the microwave signal vector of the microwave signal of each frequency; Constructing a vector matrix comprising angles of each microwave signal vector; The moisture content of the material to be tested is determined according to the vector matrix. 3. The microwave moisture measuring method according to claim 2, characterized in that the moisture content of the material to be measured is determined according to the vector matrix and a preset regression coefficient matrix. 4. The microwave moisture measurement method according to any one of claims 1 to 3, characterized in that, comprising at least one of the following items: said predetermined number is 100; The frequency interval is within the range of 500MHz to 10GHz; The microwave transmitting antenna sequentially transmits microwave signals of frequencies corresponding to a predetermined number of frequency information within a predetermined time period. 5. A microwave moisture measuring device, characterized in that, comprising: A type determination module, used to obtain material type information; A frequency information determination module, configured to extract a predetermined number of frequency information from frequency intervals corresponding to the material type information according to the material type information; The microwave irradiation control module is used to control the microwave transmitting antenna to sequentially transmit microwave signals of frequencies corresponding to the predetermined number of frequency information, and obtain microwave signals received by the microwave receiving antenna; The vector determination module is used to determine the phase difference and damping attenuation of the microwave signals of each frequency received by the microwave receiving antenna relative to the microwave signals of each frequency emitted by the microwave transmitting antenna; and the phase difference of the microwave signals of each frequency is the first The first vector and the damping attenuation are the second vector, and the microwave signal vectors of the microwave signals of each frequency are respectively obtained by superimposing the first vector and the second vector; The water content determination module is used to determine the water content of the material to be tested according to the microwave signal vector of the microwave signal of each frequency. 6. microwave moisture measuring device according to claim 5, is characterized in that, described water content determination module comprises: An included angle determination module is used to determine the included angle of the microwave signal vector of the microwave signal of each frequency; A matrix construction module is used to construct a vector matrix comprising angles of each microwave signal vector; A determining module, configured to determine the water content of the material to be tested according to the vector matrix. 7 . The microwave moisture measuring device according to claim 6 , wherein the determining module determines the moisture content of the material to be measured according to the vector matrix and a preset determined regression coefficient matrix. 8. The microwave moisture measuring device according to any one of claims 5 to 7, characterized in that it comprises at least one of the following items: said predetermined number is 100; The frequency interval is within the range of 500MHz to 10GHz; The microwave irradiation control module controls the microwave transmitting antenna to sequentially transmit microwave signals of frequencies corresponding to a predetermined number of frequency information within a predetermined time period. 9. A device comprising a memory, a processor, and a computer program stored on the memory and operable on the processor, wherein the computer program according to claim 1 is implemented when the processor executes the computer program. - The method described in any one of 4. 10. A computer storage medium, on which a computer program is stored, characterized in that, when the computer program is executed by a processor, the steps of the method according to any one of claims 1-4 are implemented.