A distributed electromagnetic field detection method and apparatus

Abstract

The application discloses a kind of distributed electromagnetic field detection methods, belong to electromagnetic field, by installing multiple field intensity detection nodes on detection environment or equipment to be detected, utilize distributed field intensity detection node and scaling node to realize the real-time monitoring of the environmental electromagnetic pollution situation of key area, build electromagnetic pollution early warning system.The application can also be applied to large equipment, such as automobile, airplane and automation production line and the electromagnetic field distributed detection of equipment system in and outside adjacent space, realize the analysis and construction of the field intensity distribution characteristics of large electrical equipment system itself near-field electromagnetic field.The application also relates to the distributed electromagnetic field detection device for implementing the above-mentioned distributed electromagnetic field detection method.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic technology, and in particular to a method and apparatus for detecting distributed electromagnetic fields. Background Technology

[0002] With the development of science and technology, more and more electromagnetic radiation facilities have entered various fields of human life and production, such as communication base stations, high-voltage power transmission and transformation stations, and various electronic devices. This has made electromagnetic pollution in the daily environment increasingly serious, posing potential risks to the normal operation of equipment and people's health. Electromagnetic fields are invisible, intangible, and difficult to detect, urgently requiring specialized equipment and technical methods to achieve real-time monitoring and early warning of electromagnetic pollution in key areas. In addition, complex electrical equipment systems such as new energy vehicles, large passenger aircraft, high-speed trains, and automated production lines consist of numerous active electronic and electrical devices and cables, and are in close contact with users. Therefore, the detection and analysis of their near-field electromagnetic field distribution can further identify the main interference sources within the system, promote the improvement of electromagnetic compatibility reliability between various components of the equipment, and, based on the near-field field strength detection results, achieve electromagnetic radiation safety analysis and assessment for users of the equipment system.

[0003] Currently, the technical solutions for distributed electromagnetic field detection systems that can be used in the above scenarios are not yet perfect. The main drawbacks are: 1. Setting up fixed detection base stations and pre-determining the location information of the detection base stations makes dynamic positioning impossible and lacks flexibility; 2. The detection node structure is complex and cannot achieve sufficient miniaturization, portability and low power consumption. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, one of the objectives of this invention is to provide a distributed electromagnetic field detection method that enables dynamic and automatic positioning of detection nodes, makes installation more flexible and convenient, and does not require other tools to calibrate the position of the nodes.

[0005] To overcome the shortcomings of the prior art, the second objective of this invention is to provide a distributed electromagnetic field detection device that enables dynamic and automatic positioning of detection nodes, is more flexible and convenient to install, and does not require other tools to calibrate the position of the nodes.

[0006] One of the objectives of this invention is achieved through the following technical solution:

[0007] A distributed electromagnetic field detection method includes the following steps:

[0008] S1: Install multiple field strength detection nodes in the testing environment or on the equipment to be tested;

[0009] S2: Set up the positioning auxiliary mechanism and install calibration nodes on the positioning auxiliary mechanism, and define the reference coordinate system;

[0010] S3: The centralized control unit enters the location coordinate information of the calibration nodes and the identification information of all the field strength detection nodes;

[0011] S4: The centralized control unit sends the synchronization time information to ensure the time synchronization of all the field strength detection nodes and the centralized control unit;

[0012] S5: The centralized control unit sends the start positioning instruction, and all the nodes feed back the location information to the centralized control unit after completing the positioning;

[0013] S6: The centralized control unit constructs the spatial location structure model of the sensor network composed of the detection nodes;

[0014] S7: The centralized control unit sends the frequency band and resolution information of the detected electromagnetic field strength, and initializes the detection parameters of the detection nodes;

[0015] S8: The detection nodes transmit the detected field strength information to the centralized control unit through the calibration nodes;

[0016] S9: The centralized control unit corresponds the field strength information, the time information and the node location information to obtain the field strength distribution of the detected area.

[0017] Further, in step S1, there is a spacing between the multiple field strength detection nodes, and a single node cannot be completely blocked.

[0018] Further, in step S2, the calibration auxiliary mechanism is unfolded into a square and placed near the sensor network composed of the detection nodes, so that the vertex of the calibration auxiliary mechanism is not blocked by the line connecting more detection nodes.

[0019] Further, in step S2, the sensor network calibration node device is installed at the vertex of the square, one of the calibration nodes is taken as the coordinate origin, the square edges passing through the coordinate origin are taken as the X axis and the Y axis, and the direction perpendicular to the auxiliary calibration device is taken as the Z axis to construct a Cartesian coordinate system, which is used to determine the location information of the detection nodes. After the coordinate system is determined, the location coordinates of the calibration nodes on the calibration auxiliary mechanism can be determined.

[0020] Further, in step S5, after all nodes complete positioning, the position information is fed back to the centralized control unit, specifically: after receiving the position request instruction, the reference node feeds back the position information to the corresponding detection node, and initiates the DTOA-based ranging process to obtain the distance information of the detection node and the reference node; when the to-be-positioned node obtains the distance information and position information of more than three reference nodes, the position coordinates in the system-defined coordinate system are obtained through maximum likelihood estimation; the detection node obtaining the position coordinates can answer the position request information of other nodes, and the determination of the position coordinates of all detection nodes is recursively completed; after the detection node completes positioning, the position information is fed back to the centralized control unit.

[0021] The second purpose of the application is achieved by the following technical scheme:

[0022] A distributed electromagnetic field detection device is used to implement any one of the above-mentioned distributed electromagnetic field detection methods, and the distributed electromagnetic field detection device comprises a plurality of field strength detection nodes, reference nodes, positioning auxiliary mechanisms, and a centralized control unit; the plurality of field strength detection nodes are installed on a detection environment or a to-be-detected device to realize detection and positioning of node position information; the reference nodes are installed on the positioning auxiliary mechanisms to obtain accurate position information of the field strength detection nodes in a specific coordinate system; and the centralized control unit receives detection data and positioning information of each field strength detection node and constructs an electromagnetic field strength spatial distribution model at different frequency points.

[0023] Further, each field strength detection node comprises an antenna group, a radio frequency sampling module, a micro control module, and a UWB communication positioning module; the antenna group receives radio frequency signals in space and transmits them to the radio frequency sampling module; the radio frequency sampling module collects radio frequency signals of a specific frequency band at a specific sampling rate and intermediate frequency bandwidth and transmits them to the micro control module; the micro control module calculates and analyzes the radio frequency sampling data to obtain radio frequency intensity information at a corresponding frequency point, and transmits the radio frequency intensity information to the UWB communication positioning module.

[0024] Further, the reference node comprises a UWB communication positioning module, which obtains the position information of the reference node, so as to further calculate the position information of the field strength detection node in the same coordinate system.

[0025] Further, the centralized control unit comprises a UWB communication module and a calculation and analysis module; the UWB communication module can send instructions or initialization information to the field strength detection nodes and the reference nodes, and receive detection data and positioning information of each detection node; and the calculation and analysis module calculates and analyzes the positioning information of the nodes and the detection results of the electromagnetic field strength, and constructs an electromagnetic field strength spatial distribution model at different frequency points.

[0026] Further, the positioning auxiliary mechanism comprises four connecting rods and a positioning rod, the four connecting rods are equal in length and connected end to end to form a foldable structure, the positioning rod is installed at two adjacent connecting rods, so that the four connecting rods are positioned and form a square structure, and the positioning node is installed at the square positioning point.

[0027] Compared with the prior art, the distributed electromagnetic field detection method can realize dynamic automatic positioning of the detection node, is more flexible and convenient to install the field strength detection node, and does not need other tools to calibrate the position of the node; the distributed electromagnetic field detection method is based on an integrated sampling and communication positioning chip, realizes miniaturization and low power consumption of the node device, and designs a portable node position calibration device and mechanism, so that a spatial reference coordinate system based on the calibration node can be conveniently constructed in an environment without a position reference, and accurate positioning of the detection node in the coordinate system is realized. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 A flowchart of the distributed electromagnetic field detection method is shown in FIG. 1.

[0029] Figure 2 A schematic diagram of a field strength detection node of the distributed electromagnetic field detection device is shown in FIG. 2.

[0030] Figure 3 A schematic diagram of a calibration node of the distributed electromagnetic field detection device is shown in FIG. 3.

[0031] Figure 4 A schematic diagram of a centralized control unit of the distributed electromagnetic field detection device is shown in FIG. 4. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0033] It should be noted that when a component is referred to as being "fixed" to another component, it can be directly on the other component or can be fixed through another intermediate component. When a component is referred to as being "connected" to another component, it can be directly connected to the other component or can be connected through another intermediate component. When a component is referred to as being "disposed" on another component, it can be directly disposed on the other component or can be disposed through another intermediate component. The terms "vertical", "horizontal", "left", "right", and the like used herein are for illustrative purposes only.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0035] Figure 1 This is a flowchart of the distributed electromagnetic field detection method of the present invention. The distributed electromagnetic field detection method includes the following steps:

[0036] S1: Install multiple field strength detection nodes in the testing environment or on the equipment to be tested;

[0037] S2: Set up the positioning auxiliary mechanism and install calibration nodes on the positioning auxiliary mechanism, and define the reference coordinate system;

[0038] S3: The centralized control unit inputs the coordinate information of the calibration node location and the identification information of all field strength detection nodes;

[0039] S4: The centralized control unit sends synchronization time information to ensure that the time of all field strength detection nodes and the centralized control unit is synchronized.

[0040] S5: The central control unit sends a start positioning command, and after all nodes complete positioning, the location information is fed back to the central control unit;

[0041] S6: The centralized control unit constructs a spatial location structure model of the sensor network composed of detection nodes;

[0042] S7: The centralized control unit sends the frequency band and resolution information for detecting electromagnetic field strength and initializes the detection parameters of the detection nodes;

[0043] S8: The detection node transmits the detected field strength information to the centralized control unit through the calibration node;

[0044] S9: The centralized control unit matches the field strength information, time information, and node location information to obtain the field strength distribution of the detected area.

[0045] Specifically, in step S1, the number of field strength detection nodes is tens to hundreds, there is a spacing between the plurality of field strength detection nodes, and a single node cannot be completely blocked. In step S2, the calibration auxiliary mechanism is unfolded into a square and placed near the sensor network formed by the detection nodes, so that the vertex of the calibration auxiliary mechanism is not blocked by the line of more detection nodes. In step S2, the sensor network calibration node device is installed at the vertex of the square, one of the calibration nodes is taken as the coordinate origin, the square edges passing through the coordinate origin are taken as the X and Y axes, and the direction perpendicular to the auxiliary calibration device is taken as the Z axis to construct a Cartesian coordinate system, which is used to determine the position information of the detection nodes. After the coordinate system is determined, the position coordinates of the calibration nodes on the calibration auxiliary mechanism can be determined. In step S5, after all the nodes complete positioning, the position information is fed back to the centralized control unit. Specifically, the calibration nodes receive the position request instruction, feed back the position information to the corresponding detection nodes, start the DTOA-based ranging process, obtain the distance information of the detection nodes and the calibration nodes, and when the to-be-positioned nodes obtain the distance information and position information of more than three calibration nodes, the position coordinates in the system-defined coordinate system are obtained through maximum likelihood estimation. The detection nodes that obtain the position coordinates can answer the position request information of other nodes to recursively complete the determination of the position coordinates of all detection nodes. After the positioning of the detection nodes is completed, the position information is fed back to the centralized control unit.

[0046] The application also relates to a distributed electromagnetic field detection device, which comprises a plurality of field strength detection nodes, calibration nodes, a positioning auxiliary mechanism, and a centralized control unit.

[0047] Please continue to refer to Figure 2Each field strength detection node comprises an antenna group, a radio frequency sampling module, a micro control module, a UWB communication positioning module and a power module. The antenna group is a small antenna group, which is used to receive radio frequency signals in space and transmit them to the corresponding radio frequency input port of the radio frequency sampling module. The radio frequency sampling module can collect radio frequency signals of a specific frequency band at a specific sampling rate and intermediate frequency bandwidth according to the control instructions of the micro control module, and convert the radio frequency signals into digital signals of a specific communication protocol format and transmit them to the micro control module. The micro control module calculates and analyzes the radio frequency sampling data to obtain the radio frequency strength information of the corresponding frequency point, and transmits the corresponding data to the UWB communication positioning module through a high-speed communication interface such as USB3.0. The UWB communication positioning module transmits the radio frequency field strength information through UWB wireless communication with the central control unit. The UWB communication positioning module of the single field strength detection node device can also communicate with the UWB communication positioning modules of other field strength detection node devices or sensor network calibration node devices with known position information, to realize the detection and positioning of node position information. The power module is composed of a lithium battery pack, a charging circuit and a voltage conversion circuit, which provides long-time power supply for the whole node device.

[0048] Please continue to refer to Figure 3 The calibration node removes the antenna group, the radio frequency sampling module and the micro control module relative to the field strength detection node, and only retains the UWB communication positioning module and the power module. Thus, the calibration node is further miniaturized and low in power consumption. The sensor network calibration node is installed on the calibration auxiliary mechanism, so as to obtain accurate position information in a specific coordinate system. The position information of the detection node relative to the calibration node is obtained through the UWB technology detection node, so as to further calculate the position information of the detection node in the same coordinate system.

[0049] The calibration auxiliary mechanism is composed of four connecting rods with equal length and connected end to end, which can be folded and stored. When used, it can be unfolded into a square, and the included angle of the two connecting rods is determined by a short rod with a specific length straddling the two connecting rods. The pins at both ends of the short rod are inserted into the mounting holes of the connecting rods, so that the two rods can be unfolded into a square. The calibration node is installed at the top of the square. Usually, 3-4 calibration node devices are installed. Taking one of the calibration nodes as the origin, taking the square edges of the auxiliary mechanism as the X and Y axes of the positioning coordinate system, and taking the Z axis perpendicular to the square plane upward, a corresponding Cartesian coordinate system is constructed. Thus, the position coordinates of the calibration nodes installed at the other vertices of the auxiliary mechanism can be determined.

[0050] Please continue to refer to Figure 4The centralized control unit is composed of a UWB communication module, a data storage module, a calculation and analysis module, a remote communication module and a display module. The UWB communication module can communicate with the detection nodes and the calibration nodes in short distance, send instructions or initialization information to the related nodes, and receive the detection data and positioning information of each detection node. The data storage module stores the detection data and other information uploaded by each node. The calculation and analysis module is used to control the working state of the nodes, and to calculate and analyze according to the positioning information of the nodes and the detection results of the electromagnetic field strength, so as to construct the electromagnetic field strength spatial distribution model of different frequency points. The remote communication module can realize the remote communication and management of the centralized control unit.

[0051] When using the distributed electromagnetic field detection device, a plurality of field strength detection node devices are installed in the environment or equipment to be detected. Only the node spacing needs to be reasonably arranged and the single node cannot be completely blocked. The calibration auxiliary mechanism is unfolded into a square and placed at a suitable position near the sensor network composed of detection nodes, so that the vertex is not blocked by the connection line of more detection nodes. The calibration auxiliary device is generally placed on the ground. The sensor network calibration node device is installed at the vertex of the square, and one of the calibration nodes is taken as the coordinate origin. The square edge passing through the coordinate origin is the X-axis and Y-axis, and the direction perpendicular to the auxiliary calibration device is the Z-axis, to construct a Cartesian coordinate system. The coordinate system is used to determine the position information of the detection nodes. After the coordinate system is determined, the position coordinates of the calibration nodes on the calibration auxiliary mechanism can be determined. The centralized control unit is placed near the calibration nodes. First, the number of calibration nodes and detection node devices used is entered in the centralized control unit, and the position information of the corresponding calibration nodes in the self-defined Cartesian coordinate system is entered. In this way, the position information of 3-4 nodes in the system is known. The centralized control unit sends time synchronization information to each node to ensure the time synchronization of the nodes and the centralized control unit, and provides a unified time scale for field strength detection and intensity distribution reconstruction. The centralized control unit sends a start positioning instruction. The detection node broadcasts a position information request instruction, and the calibration node feeds back the position information to the corresponding detection node after receiving the position request instruction, and starts the DTOA-based ranging process to obtain the distance information of the detection node and the calibration node. When the to-be-positioned node obtains the distance information and position information of more than three calibration nodes, the position coordinates in the system-defined coordinate system can be obtained through maximum likelihood estimation. The detection node that has obtained the position coordinates can answer the position request information of other nodes. In this way, the determination of the position coordinates of all detection nodes is recursively completed. After the positioning of the detection nodes is completed, the position information is fed back to the centralized control unit. The centralized control unit can construct the spatial structure of the sensor network according to the position coordinates of the nodes. After the positioning of all nodes is completed, the centralized control unit sends the radio frequency field strength range to be detected to the detection nodes for initialization setting and starts the detection function of the detection nodes. The detection node transmits the detected data, i.e. the detection timestamp information, to the centralized control unit in real time. The centralized control unit associates the field strength detection data and the position information to obtain the spatial distribution of the radio frequency field strength in a specific frequency range.

[0052] The application constitutes an electromagnetic field monitoring network through a plurality of field strength detection nodes installed on a monitored environment or device. Field strength information measured by each node describes the interference electromagnetic field strength distribution of the monitoring network coverage range. The calibration node and the calibration auxiliary mechanism jointly constitute a position reference for the positioning of the monitoring network detection nodes. Through UWB positioning technology and TDOA positioning algorithm, the relative position information of each node relative to the sensor network calibration node device of the calibration auxiliary mechanism is obtained, the calibration of the spatial position information of each detection node is realized, and the spatial structure of the monitoring network is constructed. The centralized control unit is used for managing and controlling the field strength detection node device and the sensor network calibration node device, realizing accurate positioning of the nodes, parameter setting of the detection nodes, communication management of the nodes and the central control, and collection, processing and remote transmission of the field strength information.

[0053] The application realizes a distributed electromagnetic field strength detection network composed of low-power and miniaturized electromagnetic field strength detection nodes, which can dynamically position the detection node position, through an integrated RF sampling chip and a low-power UWB communication positioning module, realizes flexible deployment and rapid detection of various application scenarios. Through UWB technology, high-speed transmission and low interference of detection data in the network are realized, real-time transmission of wide-band detection data is realized, and the interference of the communication module on the environment field strength detection is minimized.

[0054] The above embodiments only express several embodiments of the application, and the description is more specific and detailed, but it cannot be understood as a limitation on the scope of the patent. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the application, a number of modifications and improvements can be made, which are equivalent modifications and evolutions of the above embodiments according to the essential technology of the application, and these all belong to the protection scope of the application.

Claims

1. A distributed electromagnetic field detection method, characterized in that, Includes the following steps: S1: Install multiple field strength detection nodes in the testing environment or on the equipment to be tested; S2: Arrange the positioning auxiliary mechanism and install calibration nodes on it. Define a reference coordinate system. Unfold the positioning auxiliary mechanism into a square and place it near the sensor network formed by the detection nodes, ensuring that the vertices of the positioning auxiliary mechanism and the lines connecting to multiple detection nodes are unobstructed. Install sensor network calibration node devices at the vertices of the square. Using one of the calibration nodes as the origin, the edges of the square passing through the origin as the X and Y axes, and the direction perpendicular to the positioning auxiliary mechanism as the Z axis, construct a Cartesian coordinate system. This coordinate system is used to determine the position information of the detection nodes. After the coordinate system is determined, the position coordinates of the calibration nodes on the positioning auxiliary mechanism can be determined. The positioning auxiliary mechanism includes four connecting rods and one positioning rod. The four connecting rods are of equal length and are connected end to end to form a foldable structure. The two ends of the positioning rod are installed on two adjacent connecting rods, so that the four connecting rods are positioned and form a square structure. The calibration node is installed at the vertices of the square. S3: The centralized control unit inputs the coordinate information of the calibration node location and the identification information of all field strength detection nodes; S4: The centralized control unit sends synchronization time information to ensure that the time of all field strength detection nodes and the centralized control unit is synchronized. S5: The central control unit sends a start positioning command, and after all nodes complete positioning, the location information is fed back to the central control unit; S6: The centralized control unit constructs a spatial location structure model of the sensor network composed of detection nodes; S7: The centralized control unit sends the frequency band and resolution information for detecting electromagnetic field strength and initializes the detection parameters of the detection nodes; S8: The detection node transmits the detected field strength information to the centralized control unit through the calibration node; S9: The centralized control unit matches the field strength information, time information, and node location information to obtain the field strength distribution of the detected area.

2. The distributed electromagnetic field detection method according to claim 1, characterized in that: In step S1, there is a gap between multiple field strength detection nodes, and no single node can be completely blocked.

3. The distributed electromagnetic field detection method according to claim 1, characterized in that: In step S5, after all nodes complete positioning, they feed back their position information to the centralized control unit. Specifically, after receiving a position request instruction, the calibration node feeds back its position information to the corresponding detection node and initiates a ranging process based on TDOA technology to obtain the distance information between the detection node and the calibration node. When the node to be positioned obtains the distance and position information of more than three calibration nodes, it obtains its position coordinates in the system-defined coordinate system through maximum likelihood estimation. The detection node that has obtained its position coordinates can respond to the position request information of other nodes. This process is repeated to determine the position coordinates of all detection nodes. After the detection nodes have completed positioning, they feed back their position information to the centralized control unit.

4. A distributed electromagnetic field detection device for implementing the distributed electromagnetic field detection method as described in any one of claims 1-3, characterized in that: The distributed electromagnetic field detection device includes several field strength detection nodes, calibration nodes, a positioning auxiliary mechanism, and a centralized control unit. Several of the field strength detection nodes are installed in the detection environment or on the device to be tested to detect and locate the node position information. The calibration nodes are installed on the positioning auxiliary mechanism to obtain the accurate position information of the field strength detection nodes in a specific coordinate system. The centralized control unit receives the detection data and positioning information of each field strength detection node and constructs a spatial distribution model of electromagnetic field strength at different frequencies.

5. The distributed electromagnetic field detection device according to claim 4, characterized in that: Each field strength detection node includes an antenna group, a radio frequency sampling module, a micro control module, and a UWB communication and positioning module. The antenna group receives radio frequency signals in space and transmits them to the radio frequency sampling module. The radio frequency sampling module collects radio frequency signals in a specific frequency band at a specific sampling rate and intermediate frequency bandwidth and transmits them to the micro control module. The micro control module calculates and analyzes the radio frequency sampling data to obtain the radio frequency strength information of the corresponding frequency point and transmits the radio frequency strength information to the UWB communication and positioning module.

6. The distributed electromagnetic field detection device according to claim 4, characterized in that: The calibration node includes a UWB communication positioning module, which obtains the location information of the calibration node and then further calculates the location information of the field strength detection node in the same coordinate system.

7. The distributed electromagnetic field detection device according to claim 4, characterized in that: The centralized control unit includes a UWB communication module and a calculation and analysis module. The UWB communication module can send instructions or initialization information to the field strength detection node and the calibration node, and receive detection data and positioning information from each detection node. The calculation and analysis module performs calculations and analyses based on the positioning information of the nodes and the detection results of the electromagnetic field strength to construct a spatial distribution model of the electromagnetic field strength at different frequencies.

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