Method and system for measuring water content of waste paper based on separated radar

Abstract

The invention provides a waste paper water content measuring method and system based on separated radar, and belongs to the technical field of radar measurement, and the method comprises the steps: obtaining to-be-measured target waste paper, measuring dielectric constants of water and dry paper, and determining the dielectric constant of the target waste paper; setting separated radar parameters, transmitting a radar signal to the target waste paper by adopting a separated radar, and receiving a returned radar echo signal; calculating a radar backscattering coefficient based on the dielectric constant of the waste paper, the surface roughness, the radar parameter and the radar echo signal; and based on the backscattering coefficient, constructing a mathematical model between the backscattering coefficient and the water content of the waste paper through a linear regression method, and solving the mathematical model to obtain the water content of the waste paper. The method realizes non-contact, real-time and accurate measurement of the moisture state of the waste paper, has wide application potential, and is particularly suitable for the industries of waste paper recovery, transportation, treatment and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of radar measurement, and particularly relates to a method and system for measuring the water content of waste paper based on a separated radar. Background Art

[0002] The statements in this part only provide background technical information related to the present invention, and do not necessarily constitute prior art.

[0003] The water content of waste paper is one of the key factors affecting the performance and quality of waste paper. During the recycling, reuse, and production processes of waste paper, accurately measuring the water content of waste paper is of great significance for improving product quality, saving energy and reducing consumption, and environmental protection.

[0004] Traditional methods for measuring the water content of waste paper, such as the drying method, resistance method, and infrared method, have problems such as slow measurement speed, damage to waste paper, and the need for complex sample preparation. With the development of technology, the application of radar technology in water content measurement has gradually received attention. Radar technology utilizes the propagation characteristics of electromagnetic waves and measures the physical properties of substances through reflected signals. Water has a high dielectric constant, so changes in water content will significantly affect the propagation characteristics of electromagnetic waves. By analyzing the backscattering signal of the radar, the water content of the measured object can be reflected. Compared with traditional methods, radar technology has the advantages of non-contact, fast, and real-time, and is not affected by the surface state and thickness of waste paper, making it suitable for measuring the water content of complex media such as waste paper. However, there are still certain challenges in existing radar measurement technologies. When waste paper is placed on a vehicle, if the vehicle speed is high, the propagation path of the signal may be interfered by the multipath effect, resulting in a decrease in measurement accuracy; at the same time, existing measurement systems are usually relatively complex, with high installation and maintenance costs, and are not suitable for large-scale or low-budget applications. Summary of the Invention

[0005] To overcome the deficiencies of the above-mentioned prior art, the present invention proposes a method and system for measuring the water content of waste paper based on a separated radar. By selecting an appropriate operating frequency, it can adapt to the measurement requirements of different types of waste paper and their water content, and calculate the backscattering coefficient through the intensity change of the radar echo signal, and then establish a mathematical model between the backscattering coefficient and the water content of waste paper, so as to achieve accurate measurement of the water content of waste paper. The present invention can effectively overcome the drawbacks of existing measurement technologies, has the advantages of non-contact, fast, and real-time, and is suitable for water content detection of various types of waste paper.

[0006] To achieve the above object, one or more embodiments of the present invention provide the following technical solutions: In the first aspect, a method for measuring the water content of waste paper based on a separated radar is disclosed, including: Obtain the target waste paper to be measured, measure the dielectric constants of water and dry paper, and determine the dielectric constant of the target waste paper; Set the parameters of the separated radar, use the separated radar to transmit radar signals to the target waste paper, and receive the returned radar echo signals; Based on the dielectric constant, surface roughness, radar parameters, and radar echo signals of the waste paper, calculate the radar backscattering coefficient; Based on the backscattering coefficient, construct a mathematical model between the backscattering coefficient and the water content of the waste paper by linear regression method, and solve the mathematical model to obtain the water content of the waste paper.

[0007] In a second aspect, a system for measuring the water content of waste paper based on a separated radar is disclosed, including: A preprocessing module, which is configured to: obtain the target waste paper to be measured, measure the dielectric constants of water and dry paper, and determine the dielectric constant of the target waste paper; A signal acquisition module, which is configured to: set the parameters of the separated radar, use the separated radar to transmit radar signals to the target waste paper, and receive the returned radar echo signals; A model construction and measurement module, which is configured to: based on the dielectric constant, surface roughness, radar parameters, and radar echo signals of the waste paper, calculate the radar backscattering coefficient; based on the backscattering coefficient, construct a mathematical model between the backscattering coefficient and the water content of the waste paper by linear regression method, and solve the mathematical model to obtain the water content of the waste paper.

[0008] In a third aspect, an electronic device is disclosed, including a memory, a processor, and computer instructions stored on the memory and running on the processor. When the computer instructions are run by the processor, the steps of the above method for measuring the water content of waste paper based on a separated radar are completed.

[0009] In a fourth aspect, a computer-readable storage medium is disclosed, which is used to store computer instructions. When the computer instructions are executed by a processor, the steps of the above method for measuring the water content of waste paper based on a separated radar are completed.

[0010] In a fifth aspect, a computer program product is disclosed, including a computer program, and when the computer program is executed by a processor, the above method for measuring the water content of waste paper based on a separated radar is implemented.

[0011] Compared with the prior art, the beneficial effects of the present invention are: The present invention provides a method for measuring the water content of waste paper based on a split radar, which overcomes the defects in traditional methods and realizes non-contact, fast, and accurate measurement of the water content of waste paper through radar technology. This method not only improves the measurement speed but also reduces the damage to waste paper, and can perform accurate measurement in a wider range of application scenarios. Especially in the fields of large-scale production and waste paper recycling, it has great practical application value.

[0012] The present invention proposes that the propagation characteristics of radar waves can effectively reflect the change of the water content of waste paper, effectively realizing fast and accurate measurement of the water content of waste paper, and can process waste paper samples of different types and thicknesses. By processing the radar wave echo signal, the water content of waste paper can be monitored in real time and continuously without contact. Using low-frequency radar can deeply detect the water information inside waste paper, avoiding the limitation of shallow penetration of high-frequency radar and ensuring the applicability to thick paper or waste paper with a large density.

[0013] The present invention can automatically execute functions such as radar signal transmission, echo signal reception, data analysis, and water content calculation. The program automatically calculates the backscattering coefficient by real-time reading of radar signals and echo information, and calculates the water content of waste paper based on this. This program has the characteristics of simple operation and rapid response, and can provide accurate measurement results for users.

[0014] Advantages of additional aspects of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. Brief Description of the Drawings

[0015] The specification drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention.

[0016] Figure 1 It is a schematic flow chart of the method for measuring the water content of waste paper based on a split radar described in Embodiment 1 of the present invention. Detailed Description of the Embodiments

[0017] It should be noted that the following detailed descriptions are all exemplary and are intended to provide further description of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0018] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention.

[0019] Without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0020] Example 1 In one or more embodiments, a method for measuring the water content of waste paper based on a separated radar is disclosed. As Figure 1 shown, it includes the following steps: Step 1: Obtain the target waste paper to be measured, measure the dielectric constants of water and dry paper, and determine the dielectric constant of the target waste paper; Recover the waste paper to be measured and determine its dielectric constant. The dielectric constant of waste paper is greatly affected by the moisture content. The dielectric constant of waste paper can be expressed as:

[0021] Wherein, is the dielectric constant of the waste paper substrate; is the dielectric constant of water, and the dielectric constant of water is about 80 at room temperature; is the dielectric constant of dry paper, which is calibrated by experiments; is the volume fraction of water, which is measured by a densitometer.

[0022] Step 2: Set the parameters of the separated radar, use the separated radar to transmit radar signals to the target waste paper, and the vehicle loaded with waste paper drives vertically and uniformly along the radar signal path, so that the waste paper is evenly penetrated by the radar signals, and then receive the penetrated radar signals; In this embodiment, the separated radar means that the radar transmitting antenna and the receiving antenna are physically separated and non-integrated. By physical separation, the direct interference of the transmitted signal on the receiving system is reduced; the separated design is convenient for separate maintenance or replacement of components, and the maintenance cost is low; it is suitable for the mobile measurement scenario of vehicles loaded with waste paper. The radar system uses a low-frequency radar, and a radar with a frequency of 30 MHz can be used. Its wavelength is relatively large and it has strong penetration ability. The wavelength of the radar signal and the frequency have the following relationship:

[0023] Wherein, c is the speed of light, is the frequency of the radar signal. The low-frequency radar can effectively penetrate the waste paper and measure the water content inside it.

[0024] Set the angle and frequency points of the radar, and transmit radar signals to the target waste paper according to the predetermined angle and frequency points. The transmitting antenna transmits radar signals through high-frequency electromagnetic waves. The reflection intensity of the radar signals by the waste paper is related to its moisture content. The echo signals are received by the receiving antenna, and after signal processing, signals containing moisture information are obtained.

[0025] Step 3: Calculate the radar backscattering coefficient based on the dielectric constant, surface roughness, radar parameters, and radar echo signal of the waste paper; Radar backscattering coefficient is one of the key parameters reflecting the water content of waste paper. According to radar reflection theory, the backscattering coefficient can be calculated by the following formula:

[0026] where, is a constant, is the effective dielectric constant of the waste paper, is the distance between the radar and the waste paper. The effective dielectric constant of the waste paper is related to the surface roughness of the waste paper and is given by the following formula:

[0027] where, reflects the surface roughness of the waste paper. This coefficient is qualitatively evaluated by comparing the waste paper with a standard plate of known roughness through tactile or optical comparison using the standard roughness plate comparison method.

[0028] In this embodiment, the radar parameters include radar receiving power, radar transmitting power, antenna gain, etc.

[0029] Moreover, the radar backscattering coefficient has the following relationship with the radar parameters:

[0030] where, is the radar receiving power, is the radar transmitting power, is the antenna gain. The constant K can be measured through the relationship between the radar backscattering coefficient, the radar parameters, and the effective dielectric constant of the waste paper.

[0031] Step 4: Based on the backscattering coefficient, construct a mathematical model between the backscattering coefficient and the water content of the waste paper through linear regression method, and solve the mathematical model to obtain the water content of the waste paper.

[0032] The relationship between the backscattering coefficient and the water content of the waste paper obtained through experiments can be expressed as:

[0033] where, Water Content is the water content of the waste paper, and are parameters calculated through linear regression, is the calculated backscattering coefficient. Through this mathematical model, the water content of the waste paper can be deduced from the backscattering coefficient.

[0034] In this embodiment, a host computer is used for the above signal processing process. The host computer can be a laptop computer, a desktop computer, a tablet computer, etc.

[0035] In this embodiment, a low-frequency radar in the 30 MHz frequency band is selected for measurement. The low-frequency radar wave has a large penetration depth and can effectively capture the distribution of moisture inside the waste paper. The experimental results show that within the range of 10%-40% water content in the waste paper, the relationship between the radar echo signal and the water content presents a good linear relationship. Therefore, the water content of the waste paper can be accurately calculated by the linear regression method.

[0036] Embodiment Two In one or more embodiments, a waste paper water content measurement system based on a split radar is disclosed, specifically including: A preprocessing module, which is configured to: obtain the target waste paper to be measured, measure the dielectric constants of water and dry paper, and determine the dielectric constant of the target waste paper; A signal acquisition module, which is configured to: set the split radar parameters, use the split radar to transmit radar signals to the target waste paper, and receive the returned radar echo signals; A model construction and measurement module, which is configured to: calculate the radar backscattering coefficient based on the dielectric constant, surface roughness, radar parameters, and radar echo signals of the waste paper; based on the backscattering coefficient, construct a mathematical model between the backscattering coefficient and the water content of the waste paper by the linear regression method, and solve the mathematical model to obtain the water content of the waste paper.

[0037] Embodiment Three This embodiment provides an electronic device, including a memory and a processor, as well as computer instructions stored on the memory and running on the processor. When the computer instructions are run by the processor, the steps of the above waste paper water content measurement method based on a split radar are completed.

[0038] Embodiment Four This embodiment provides a computer-readable storage medium for storing computer instructions. When the computer instructions are executed by the processor, the steps of the above waste paper water content measurement method based on a split radar are completed.

[0039] Embodiment Five The purpose of this embodiment is to provide a computer program product containing instructions, which when running on a computer, enables the computer to execute the methods and functions involved in any one of the above embodiments. The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the present invention. It should be understood that each flow and / or block in the flowchart and / or block diagram, and the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0040] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including instruction means that implement the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0041] These computer program instructions can also be loaded onto a computer or other programmable data processing device to perform a series of operation steps on the computer or other programmable device to generate a computer-implemented process, such that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0042] In the above embodiments, the descriptions of each embodiment have their own focuses. For the parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0043] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for measuring the moisture content of waste paper based on a separation radar, characterized in that: include: Obtaining target waste paper to be tested, measuring the dielectric constants of water and dry paper, and determining the dielectric constant of the target waste paper; Setting separate radar parameters, using the separate radar to transmit radar signals to the target waste paper, and receiving returned radar echo signals; The radar backscattering coefficient is calculated based on the dielectric constant, surface roughness, radar parameters and radar echo signal of the waste paper; Based on the backscattering coefficient, a mathematical model between the backscattering coefficient and the moisture content of waste paper was constructed by linear regression method, and the moisture content of waste paper was obtained by solving the mathematical model.

2. The method for measuring the moisture content of waste paper based on a separate radar according to claim 1, characterized in that: The dielectric constant of the target waste paper is expressed as: in, is the dielectric constant of the waste paper substrate, is the dielectric constant of water, is the dielectric constant of dry paper, is the volume fraction of water.

3. The method for measuring the moisture content of waste paper based on a separate radar as claimed in claim 1, characterized in that: The radar echo signal includes the radar wavelength, which is expressed as: in, is the radar wavelength, c is the speed of light, is the frequency of the radar signal.

4. The method for measuring the moisture content of waste paper based on a separate radar according to claim 1, characterized in that: The radar backscatter coefficient is specifically calculated as: in, is a constant, is the effective dielectric constant of waste paper, is the distance between the radar and the waste paper.

5. The method for measuring the moisture content of waste paper based on a separate radar as claimed in claim 4, characterized in that: The effective dielectric constant of the waste paper is related to the surface roughness of the waste paper: in, is the surface roughness of waste paper, is the dielectric constant of the waste paper substrate; The radar backscatter coefficient has the following relationship with the radar parameters: in, is the radar receiving power, is the radar transmitting power, is the antenna gain, is the radar wavelength.

6. The method for measuring the moisture content of waste paper based on a separate radar according to claim 1, characterized in that: The mathematical model is solved to obtain the waste paper moisture content. The relationship between the backscattering coefficient and the waste paper moisture content is expressed as: Among them, Water Content is the water content of waste paper, and are the parameters calculated by linear regression, is the calculated backscattering coefficient.

7. A waste paper moisture content measurement system based on a separate radar, characterized in that: include: A pre-processing module is configured to: obtain target waste paper to be tested, measure the dielectric constants of water and dry paper, and determine the dielectric constant of the target waste paper; A signal acquisition module is configured to: set separate radar parameters, use the separate radar to transmit radar signals to the target waste paper, and receive returned radar echo signals; The model building and measurement module is configured as follows: based on the dielectric constant, surface roughness, radar parameters and radar echo signal of the waste paper, the radar backscattering coefficient is calculated; based on the backscattering coefficient, a mathematical model between the backscattering coefficient and the moisture content of the waste paper is constructed by a linear regression method, and the moisture content of the waste paper is obtained by solving the mathematical model.

8. An electronic device, characterized in that: The invention comprises a memory and a processor and computer instructions stored in the memory and executed on the processor. When the computer instructions are executed by the processor, the method for measuring the moisture content of waste paper based on a separate radar as described in any one of claims 1 to 6 is completed.

9. A computer-readable storage medium, characterized in that: Used to store computer instructions, when the computer instructions are executed by the processor, the waste paper moisture content measurement method based on the separate radar according to any one of claims 1-6 is completed.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the waste paper moisture content measurement method based on a separate radar according to any one of claims 1 to 6 is implemented.

Images