Device and method for evaluating the wireless transmission efficiency of electromagnetic signals of built-in concrete sensors

Abstract

The present invention provides a device and method for evaluating the efficiency of wireless transmission of electromagnetic signals of a sensor built-in in concrete. The device at least comprises: a transparent cylinder, a steel mesh, a wireless sensor, a signal transceiver and processing module, a signal activation and charging module and a processing terminal; the transparent cylinder is used to carry liquid whose conductivity is the same as or different from that of concrete within a set range, the steel mesh is bound together to form a steel cage, and is arranged in a single layer or double layer around the wireless sensor; the wireless sensor is communicatively connected with the signal transceiver and processing module, the signal transceiver and processing module is communicatively connected with the control terminal, and the wireless sensor is communicatively connected with the signal activation and charging module; the present invention can realize wireless reception and transmission of data of the sensor built-in in concrete, self-power supply of the sensor and efficiency evaluation of the data, and realizes true wireless passive monitoring.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless passive sensors, and in particular to a device and method for evaluating the wireless transmission efficiency of electromagnetic signals of a sensor built into concrete. Background Art

[0002] The statements in this section merely provide background art related to the present invention and do not necessarily constitute prior art.

[0003] The monitoring and early warning work for tunnel disasters runs through the entire stage of tunnel construction and operation and maintenance, especially in the early stage of tunnel construction. The accuracy of monitoring data can not only ensure construction safety and long-term stability of the structure, but also confirm the rationality of the construction method, and provide a basis for information-based design and construction. The specific detection contents include surrounding rock internal force, surrounding rock deformation, initial support steel arch deformation, initial support and secondary lining pressure, etc.

[0004] Currently, existing tunnel monitoring technology usually uses wired sensors to monitor various physical quantities and transmit data. Although it has the advantages of high transmission efficiency, stable and reliable data, and mature technology, it also has the following problems: (1) The internal structure of the tunnel is complex, and the lining structure is divided into multiple layers, so the burial of sensors is a big problem; (2) Since wired sensors require transmission cables to receive excitation and transmit data, each sensor needs to be buried with holes reserved to store the cables. For the monitoring of multiple physical quantities, a large number of cables must be laid, and the arrangement and protection of the cables are difficult to guarantee; (3) The installation, inspection and data reading of sensors mainly rely on manual operations, which will result in low efficiency and increased costs.

[0005] Wireless passive sensors solve the above problems very well. They are small in size and easy to install. They can effectively reduce the laying of cables through wireless transmission of electromagnetic waves. In addition, the on-site wireless data transmission network can be quickly established, which greatly improves work efficiency and reduces construction costs.

[0006] However, the inventors found that the current mainstream wireless passive sensors can only be arranged on the surface of the structure for monitoring and cannot be used inside the structure. In addition, in terms of data transmission, there are still many problems in data accuracy, stability and transmission efficiency. This is also the reason why wireless passive sensors cannot be applied to actual projects. Summary of the invention

[0007] In order to address the deficiencies of the prior art, the present invention provides a device and method for evaluating the wireless transmission efficiency of electromagnetic signals of sensors built into concrete, which can realize wireless reception and transmission of data from sensors built into concrete, self-power supply of sensors, and performance evaluation of data, thereby achieving true wireless passive monitoring.

[0008] In order to achieve the above object, the present invention adopts the following technical solution:

[0009] A first aspect of the present invention provides a device for evaluating the wireless transmission efficiency of electromagnetic signals of a sensor built into concrete.

[0010] A device for evaluating the wireless transmission efficiency of electromagnetic signals of a built-in concrete sensor, comprising at least:

[0011] Transparent cylinder, steel mesh, wireless sensor, signal transceiver and processing module, signal activation and charging module and processing terminal;

[0012] The transparent cylinder is used to carry liquid with the same conductivity as concrete or a difference within a set range. The steel mesh is tied together to form a steel cage, which is arranged in a single or double layer around the wireless sensor;

[0013] The wireless sensor is communicatively connected with the signal transceiving and processing module, the signal transceiving and processing module is communicatively connected with the control terminal, and the wireless sensor is communicatively connected with the signal activation and charging module.

[0014] As an optional implementation, the wireless sensor is disposed in a sealed transparent box.

[0015] As an optional implementation, the wireless sensor is wirelessly connected to the signal transceiver and processing module, the wireless sensor is wirelessly connected to the signal activation and charging module, and the signal transceiver and processing module is communicatively connected to the control terminal via a transmission cable.

[0016] As an optional implementation method, the steel mesh is welded and manufactured with a diameter and strength used in actual engineering projects, and is regularly arranged around the wireless sensor to simulate the steel mesh in actual engineering concrete.

[0017] As an optional implementation, the transparent cylinder is a transparent glass cylinder.

[0018] As an optional implementation, the signal receiving and processing module includes a wireless signal receiving device and a signal processing terminal, the wireless sensor is communicatively connected to the wireless signal receiving device, and the wireless signal receiving device is communicatively connected to the signal processing terminal.

[0019] As an optional implementation, a signal activation and charging module includes: a plastic housing, an output coil, an AC-DC converter and a frequency converter;

[0020] The output coil is arranged in the plastic shell, the frequency converter is connected to the output coil, the frequency converter is connected to the AC-DC converter, the frequency converter and the AC-DC converter are used to generate an alternating electromagnetic field, so that the coil in the wireless sensor 9 induces a voltage for charging and signal transmission.

[0021] As an optional implementation, the computer terminal module is at least configured to: parse and process the received signal, and verify whether the transmission signal is accurate, whether it reflects the actual state, the signal distortion rate, and the transmission efficiency.

[0022] As an optional implementation, the wireless sensor includes: a sensor module, an energy storage module, a data preprocessing module and a wireless transceiver module;

[0023] The sensor module is connected to the data preprocessing module, the data preprocessing module is connected to the wireless transceiver module, and the sensor module, the wireless transceiver module and the data preprocessing module are respectively connected to the energy storage module;

[0024] The energy storage module adopts the principle of electromagnetic induction to receive electromagnetic energy from the signal activation and charging module and convert it into electrical energy for storage, thus providing energy for the sensor module, data preprocessing module and wireless transceiver module.

[0025] A second aspect of the present invention provides a method for evaluating the wireless transmission efficiency of electromagnetic signals of a sensor built into concrete.

[0026] A method for evaluating the wireless transmission efficiency of electromagnetic signals of a built-in concrete sensor, using the device for evaluating the wireless transmission efficiency of electromagnetic signals of a built-in concrete sensor according to the first aspect of the present invention, comprises the following steps:

[0027] The signal activation and charging module is used to charge and activate the wireless sensor to put it into working state, and the processing terminal evaluates the received signal;

[0028] The steel mesh in the concrete structure is simulated by changing the number of steel mesh pieces and the distance between them. The thickness of the concrete in the structure is simulated by changing the volume of the added transparent liquid. The angle at which the antenna receives the signal is changed by changing the placement of the built-in wireless sensor.

[0029] Repeat the above steps according to the experimental conditions, screen and judge the experimental results, and obtain the optimal signal transmission conditions under the multi-condition coupling inside the concrete.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. The device and method for evaluating the wireless transmission efficiency of electromagnetic signals of built-in concrete sensors described in the present invention can realize the wireless reception and transmission of data from built-in concrete sensors, the self-power supply of sensors, and the performance evaluation of data, thus realizing true wireless passive monitoring.

[0032] 2. The device and method for evaluating the performance of wireless transmission of electromagnetic signals of sensors built into concrete described in the present invention simulate the steel mesh in the concrete structure by changing the number of steel meshes and the distance between them, simulate the thickness of concrete in the structure by changing the volume of the added transparent liquid, and change the angle at which the antenna receives the signal by changing the placement of the built-in wireless sensor. The effects of concrete conductivity, thickness and steel bars on electromagnetic signals are taken into account, thereby achieving a more accurate performance evaluation of the wireless transmission of electromagnetic signals of sensors, avoiding the interference of these materials on electromagnetic signals in actual projects, being more in line with actual project conditions, and being more conducive to later applications in actual projects.

[0033] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0035] Figure 1 A schematic diagram of the structure of a device for evaluating the effectiveness of wireless transmission of electromagnetic signals from a built-in sensor in concrete provided in Example 1 of the present invention;

[0036] Figure 2 This is a schematic diagram of the main module for evaluating the electromagnetic signal wireless transmission efficiency provided in Example 1 of the present invention.

[0037] Figure 3 A schematic diagram of a signal activation and charging module provided in Example 1 of the present invention;

[0038] Figure 4 A schematic diagram of a signal receiving and sending and processing module provided in Embodiment 1 of the present invention;

[0039] Figure 5 A schematic diagram of the internal structure of a wireless sensor provided in Example 1 of the present invention;

[0040] Among them: 1. Main module for evaluating the efficiency of wireless transmission of electromagnetic signals; 2. Signal receiving and processing module; 3. Signal activation and charging module; 4. Control terminal; 5. Transmission cable; 6. Transparent glass cylinder; 7. Steel mesh; 8. Sealed transparent box; 9. Wireless sensor; 10. Transparent liquid with similar conductivity to concrete; 11. Plastic shell; 12. Output coil; 13. AC-DC converter; 14. Frequency converter; 15. Wireless signal receiving device; 16. Signal processing end; 17. Sensor module; 18. Energy storage module; 19. Data preprocessing module; 20. Wireless receiving and transmitting module. DETAILED DESCRIPTION

[0041] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0042] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0043] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0044] In the present invention, terms such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "side", "bottom", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are relational words determined only for the convenience of describing the structural relationships of the various parts or elements of the present invention, and do not specifically refer to any part or element in the present invention and should not be understood as limitations on the present invention.

[0045] In the present invention, terms such as "fixed connection", "connected", "connection", etc. should be understood in a broad sense, indicating that it can be fixedly connected, integrally connected or detachably connected; it can be directly connected or indirectly connected through an intermediate medium. Relevant scientific research or technical personnel in this field can determine the specific meanings of the above terms in the present invention according to specific circumstances, and they should not be understood as limiting the present invention.

[0046] In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0047] Embodiment 1:

[0048] like Figure 1 As shown, embodiment 1 of the present invention provides a device for evaluating the wireless transmission efficiency of electromagnetic signals of built-in sensors in concrete, including a main module 1 for evaluating the wireless transmission efficiency of electromagnetic signals, a signal transceiver and processing module 2, a signal activation and charging module 3 and a control terminal 4 (for example, a computer terminal module). The main module 1 for electromagnetic signal transmission verification, the signal activation and charging module 3 and the signal transceiver and processing module 2 are connected wirelessly, and the remaining modules are connected via a transmission cable 5.

[0049] In this embodiment, the electromagnetic signal wireless transmission efficiency evaluation main module 1 includes: a transparent glass cylinder 6, a steel mesh 7, a sealed transparent box 8, a wireless sensor 9 and a transparent liquid 10 (the conductivity of the transparent liquid 10 is the same as that of concrete or the difference between the conductivity of the transparent liquid 10 and that of the concrete is within a set range);

[0050] Specifically, the transparent glass cylinder 6 is used to place the experimental device, so as to facilitate observation of the internal instrument status and adjustment. The transparent liquid 10 is disposed in the transparent glass cylinder 6 (i.e., the transparent cylinder body). It can be understood that in some other embodiments, the transparent cylinder body can also be replaced by a transparent hard cylinder body of other materials. Those skilled in the art can make a choice according to the specific working conditions, which will not be described in detail here.

[0051] In this embodiment, the wireless sensor 9 is arranged in a sealed transparent box 8, and the sealed transparent box 8 is placed in a transparent glass cylinder 6. The sealed transparent box 8 can prevent liquid from entering the sensor and damaging the sensor, thereby ensuring the normal operation of the wireless sensor 9;

[0052] The steel mesh 7 is welded and made with the diameter and strength commonly used in actual engineering, and is regularly arranged around the wireless sensor 9 to simulate the steel mesh in the concrete of actual engineering;

[0053] In this embodiment, the magnetic signal wireless transmission efficiency evaluation main module 1 mainly simulates the position of the built-in sensor in the actual project. The wireless sensor 9 can monitor the slight deformation of the structure and convert the physical signal into an electromagnetic signal, which is transmitted in the form of electromagnetic waves and captured by the signal receiving and processing module 2. It is in a dormant state when not in operation and is activated and charged by the external signal activation and charging module 3 to turn into a working state.

[0054] In this embodiment, the transparent liquid 10 uses a method of adding NaCl to a transparent organic solvent to simulate the conductivity of concrete in an actual structure. At present, the calculation method for the equivalent conductivity of reinforced concrete mainly adopts the idea of ​​weighted average, that is, the proportion of steel bars and concrete is multiplied by the theoretical conductivity of the material itself (σ 钢筋 ×V 钢筋 / V 总 +σ 混凝土 ×V 混凝土 / V 总 ), since this embodiment needs to focus on the reflection of electromagnetic waves on the surface of steel bars, it is necessary to separate the steel bars separately (σ 混凝土 ×V 混凝土 / V 总 ), concrete is replaced by similar materials, the conductivity of concrete is still calculated by weighted calculation method, the conductivity is measured by conductivity meter, transparent organic solvent can facilitate the observation of the status of internal instruments, and can also simulate the internal vacuum state well.

[0055] In this embodiment, the signal receiving and processing module 2 is mainly responsible for receiving the electromagnetic signal from the wireless sensor 9, pre-processing it, and then transmitting it to the control terminal 4 through the transmission cable 5, including a wireless signal receiving device 15 and a signal processing terminal 16. The wireless sensor 9 is connected to the wireless signal receiving device 15 for communication, and the wireless signal receiving device 15 is connected to the signal processing terminal 16 for communication.

[0056] In this embodiment, the signal activation and charging module 3 includes a plastic housing 11, an output coil 12, an AC-DC converter 13 and a frequency converter 14, wherein the output coil 12 is disposed in the plastic housing 11, the frequency converter 14 is connected to the output coil 12, and the frequency converter 14 is connected to the AC-DC converter 13;

[0057] The signal activation and charging module 3 is mainly responsible for activating the sensor 9 embedded in the structure to put it into working state and charging the wireless sensor 9. The main principle is to use the electromagnetic induction principle to send the electromagnetic signal out by radiation, and to realize wireless transmission by converting magnetic field energy into electric energy.

[0058] The frequency converter 14 and the AC-DC converter 13 can generate an alternating electromagnetic field, thereby inducing a voltage in the coil of the wireless sensor 9 for charging and signal transmission. The plastic housing 11 is used to protect the coil and can be made of a thin transparent acrylic plate.

[0059] In this embodiment, the control terminal 4 can analyze and process the signal transmitted through the transmission cable 5, and check whether the transmission signal is accurate, whether it reflects the real state, the signal distortion rate and transmission efficiency, etc.

[0060] The device described in this embodiment mainly considers the influence of concrete conductivity, thickness and steel bars on electromagnetic signals. Electromagnetic waves themselves are a kind of energy. During the transmission process, part of the energy will be lost by interaction with the medium, and another part will be lost in the form of reflection and refraction. Finally, the remaining part can be used after passing through the medium. A large number of studies have shown that during the transmission of electromagnetic signals in reinforced concrete walls, changes in concrete conductivity and steel bars will cause great attenuation of electromagnetic waves. Although the change in the thickness of plain concrete does not attenuate it much, it can still reach several tens of decibels under the effect of coupling with the steel mesh; at the same time, electromagnetic waves will reflect and diffract between the steel bars and the concrete interface. If the number of steel mesh layers is large and the mesh is dense, the action process will be more complicated and the attenuation effect will be stronger. The evaluation device described in this embodiment focuses on the above factors and realizes a more accurate evaluation of the wireless transmission performance of electromagnetic signals of sensors built into concrete.

[0061] Example 2

[0062] Embodiment 2 of the present invention provides a method for evaluating the wireless transmission efficiency of electromagnetic signals of a built-in concrete sensor, using the device for evaluating the wireless transmission efficiency of electromagnetic signals of a built-in concrete sensor described in Embodiment 1, comprising:

[0063] First, the steel mesh 7 and the transparent liquid 10 in the electromagnetic signal wireless transmission efficiency evaluation main module 1 are set, and according to the experimental working conditions, the steel mesh 7 is tied together by steel wire to form a steel cage, which is arranged in a single layer or double layer around the wireless sensor 9;

[0064] The conductivity of the transparent liquid 10 was measured with a conductivity meter before addition, and NaCl was added to adjust the conductivity value to be similar to that of common concrete;

[0065] The transparent glass cylinder 6 has a size of 60 cm×50 cm×50 cm. The transparent glass cylinder 6 is marked with scales, which can be used to control the volume of the transparent liquid 10 added, and at the same time realize the visualization of the experimental process;

[0066] After arranging the various parts of the electromagnetic signal wireless transmission efficiency evaluation main module 1 according to the experimental working conditions, adjust the position and angle of the fixed signal transceiver and processing module 2, use the transmission cable 5 to establish a connection between the processing terminal 4 and the signal transceiver and processing module 2, and set the relevant parameters;

[0067] Finally, the signal activation and charging module 3 is used to charge and activate the wireless sensor 9, so that it enters the working state, and then the received signal is evaluated; wherein, the energy storage module 18 adopts the electromagnetic induction principle, can receive the electromagnetic energy from the signal activation and charging module 3 and convert it into electrical energy for storage, and provide energy for the sensor module 17, the data preprocessing module 19 and the wireless transceiver module 20;

[0068] In this embodiment, the steel mesh in the concrete structure is simulated by changing the number of steel mesh sheets 7 and the distance between them; the thickness of the concrete in the structure is simulated by changing the volume of the added transparent liquid 10; and the angle at which the antenna receives the signal can be changed by changing the placement of the built-in wireless sensor;

[0069] Repeat the above steps according to the experimental conditions, screen and evaluate the experimental results, and find out the optimal transmission conditions under the coupling of multiple conditions inside the concrete.

[0070] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A device for evaluating the wireless transmission efficiency of electromagnetic signals of a built-in concrete sensor, characterized in that: At least: Transparent cylinder, steel mesh, wireless sensor, signal transceiver and processing module, signal activation and charging module and control terminal; The transparent cylinder is used to carry liquid with the same conductivity as concrete or a difference within a set range. The steel mesh is tied together to form a steel cage, which is arranged in a single or double layer around the wireless sensor; The wireless sensor is connected in communication with the signal transceiver and processing module, the signal transceiver and processing module is connected in communication with the control terminal, and the wireless sensor is connected in communication with the signal activation and charging module; The wireless sensor is set in a closed transparent box. The steel mesh is welded with the diameter and strength used in actual engineering projects and is regularly arranged around the wireless sensor to simulate the steel mesh in actual engineering concrete.

2. The device for evaluating the wireless transmission efficiency of electromagnetic signals of a built-in concrete sensor as claimed in claim 1, characterized in that: The wireless sensor is wirelessly connected to the signal transceiver and processing module, the wireless sensor is wirelessly connected to the signal activation and charging module, and the signal transceiver and processing module is communicatively connected to the control terminal via a transmission cable.

3. The device for evaluating the wireless transmission efficiency of electromagnetic signals of a built-in concrete sensor as claimed in claim 1, characterized in that: The transparent cylinder body is a transparent glass cylinder body.

4. The device for evaluating the wireless transmission efficiency of electromagnetic signals of a built-in concrete sensor as claimed in claim 1, characterized in that: The signal receiving and processing module includes a wireless signal receiving device and a signal control terminal. The wireless sensor is connected to the wireless signal receiving device for communication, and the wireless signal receiving device is connected to the signal control terminal for communication.

5. The device for evaluating the wireless transmission efficiency of electromagnetic signals of a built-in concrete sensor as claimed in claim 1, characterized in that: Signal activation and charging module, including: plastic housing, output coil, AC-DC converter and inverter; The output coil is arranged in the plastic shell, the frequency converter is connected to the output coil, the frequency converter is connected to the AC-DC converter, the frequency converter and the AC-DC converter are used to generate an alternating electromagnetic field, so that the coil in the wireless sensor induces a voltage for charging and signal transmission.

6. The device for evaluating the wireless transmission efficiency of electromagnetic signals of a built-in concrete sensor as claimed in claim 1, characterized in that: The control terminal is at least configured to: analyze and process the received signal, and check whether the transmission signal is accurate, whether it reflects the real state, the signal distortion rate and the transmission efficiency.

7. The device for evaluating the wireless transmission efficiency of electromagnetic signals of a built-in concrete sensor as claimed in claim 1, characterized in that: The wireless sensor comprises: a sensor module, an energy storage module, a data preprocessing module and a wireless transceiver module; The sensor module is connected to the data preprocessing module, the data preprocessing module is connected to the wireless transceiver module, and the sensor module, the wireless transceiver module and the data preprocessing module are respectively connected to the energy storage module; The energy storage module adopts the principle of electromagnetic induction to receive electromagnetic energy from the signal activation and charging module and convert it into electrical energy for storage, thus providing energy for the sensor module, data preprocessing module and wireless transceiver module.

8. A method for evaluating the wireless transmission efficiency of electromagnetic signals of sensors built into concrete, characterized in that: The device for evaluating the wireless transmission efficiency of electromagnetic signals of a built-in concrete sensor according to any one of claims 1 to 7 comprises the following steps: Use the signal activation and charging module to charge and activate the wireless sensor to put it into working state, and the control terminal evaluates the received signal; The steel mesh in the concrete structure is simulated by changing the number of steel mesh pieces and the distance between them. The thickness of the concrete in the structure is simulated by changing the volume of the added transparent liquid. The angle at which the antenna receives the signal is changed by changing the placement of the built-in wireless sensor. Repeat the above steps according to the experimental conditions, screen and judge the experimental results, and obtain the optimal signal transmission conditions under the multi-condition coupling inside the concrete.

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