Radio wave environment analysis device and radio wave environment analysis method

Radio environment analysis device and radio environment analysis method

The present disclosure relates to a radio wave environment analysis device and a radio wave environment analysis method.

In Patent Document 1, a first simulation using a ray tracing method (ray tracing method) is performed based on device information about a transmitter and a receiver and information about an environment in which transmission and reception are performed by the transmitter and the receiver. , The first reception strength at the nearby points set within the first distance for each of the installation candidate points at the center of each of the plurality of installation candidate positions where the receiver is installed. A device for determining the installation position of a wireless device to be calculated is disclosed. This installation position determining device calculates the second reception intensity of each installation candidate position based on the calculation result of the first reception intensity, and determines the installation position of the receiver based on the second reception intensity. ..

<p num="0003"><patcit num="1"><text>JP-A-2019-12875</text></patcit></p>

This disclosure was devised in view of the above-mentioned conventional situation, and suppresses an increase in the number of calculations for the overall simulation of the radio wave environment for the target area where the moving object exists in the actual environment, and suppresses the increase in the number of calculations for the overall simulation of the radio wave environment. It is an object of the present invention to provide a radio wave environment analysis device and a radio wave environment analysis method for efficiently executing analysis processing.

The radio wave environment analysis device of the present disclosure holds the position information of a radio transmitter arranged in a target area where at least one mobile body exists and the position information of a reference point at which radio waves from the radio transmitter are received. The memory to be used, the reception intensity of the radio wave at the reference point when the at least one moving body is present at the initial position, and the at least one moving body have moved a predetermined distance from the initial position a plurality of times. It includes a processor that acquires the reception intensity of the radio wave at the reference point when it exists at each of a plurality of moving positions. The processor executes a simulation of the radio wave environment in the target area based on the reception intensity of the radio wave at the reference point when the at least one moving body is present at the initial position and the plurality of moving positions. Select one or more of the plurality of moving positions for the purpose.

Further, the radio wave environment analysis method of the present disclosure retains the position information of the radio transmitter arranged in the target area where the moving body exists and the position information of the reference point at which the radio wave from the radio wave transmitter is received. Each of the step, the reception intensity of the radio wave at the reference point when the moving body is present at the initial position, and a plurality of moving positions where the moving body has moved a predetermined distance from the initial position a plurality of times. In the step of acquiring the reception intensity of the radio wave at the reference point when present, and the reception intensity of the radio wave at the reference point when the moving body is present at the initial position and the plurality of moving positions. Based on this, it has a step of selecting one or more of the plurality of moving positions for executing the simulation of the radio wave environment in the target area.

According to the present disclosure, it is possible to suppress an increase in the number of calculations for the overall simulation of the radio wave environment for the target area where the moving object exists in the actual environment, and it is possible to efficiently execute the analysis process of the overall simulation of the radio wave environment.

<figref num="1">Block diagram showing a hardware configuration example of the radio wave environment analysis device according to the first embodiment</figref><figref num="2">Perspective view showing the appearance of the radio wave measuring device</figref><figref num="3">Top view schematically showing an example of the target area</figref><figref num="4A">Graph showing example 1 of change in electric field strength with respect to the moving distance of a moving body at the reference point shown in FIG.</figref><figref num="4B">Graph showing example 2 of change in electric field strength with respect to the moving distance of the moving body at the reference point shown in FIG.</figref><figref num="5">Flow chart showing an example of the operation procedure of the radio wave environment analysis device according to the first embodiment</figref><figref num="6">The figure which shows the example of the whole simulation result of the radio wave environment in the target area corresponding to the position of the moving body shown in FIG.</figref><figref num="7">The figure which shows the operation outline example of the radio wave environment analysis apparatus which concerns on Embodiment 2.</figref><figref num="8A">A graph showing an example of changes in the electric field strength with respect to the moving distance of the moving body MV1 at the reference point shown in FIG.</figref><figref num="8B">A graph showing an example of changes in the electric field strength with respect to the moving distance of the moving body MV2 at the reference point shown in FIG.</figref><figref num="9">Flow chart showing an example of the operation procedure of the radio wave environment analysis device according to the second embodiment</figref>

(Background to the present disclosure) The technology of Patent Document 1 is premised on the use of a known ray tracing method, and according to this ray tracing method, it is possible to perform an overall simulation of the radio wave environment targeting the target area. be. However, in the overall simulation of the radio wave environment using the ray tracing method, there is a problem that the load of the arithmetic unit due to the calculation processing (analysis processing) is large. Further, in the actual environment, a person existing in the target area or a moving object such as an AGV (Automated Guided Vehicle) may move. For this reason, if the entire radio wave environment is simulated for each position of the moving body, the number of calculations becomes enormous, and a large amount of time is required for the analysis process.

Therefore, in the following embodiment 1, the increase in the number of calculations for the overall simulation of the radio wave environment targeting the target area where the moving object exists in the actual environment is suppressed, and the analysis process of the overall simulation of the radio wave environment is efficiently executed. An example of the radio wave environment analysis device and the radio wave environment analysis method will be described.

Hereinafter, embodiments in which the configuration and operation of the radio wave environment analysis device and the radio wave environment analysis method according to the present disclosure are specifically disclosed will be described in detail with reference to the drawings as appropriate. However, more detailed explanation than necessary may be omitted. For example, detailed explanations of already well-known matters and duplicate explanations for substantially the same configuration may be omitted. This is to avoid unnecessary redundancy of the following description and to facilitate the understanding of those skilled in the art. It should be noted that the accompanying drawings and the following description are provided for those skilled in the art to fully understand the present disclosure and are not intended to limit the subject matter described in the claims.

&lt;Embodiment 1&gt; In the following embodiment 1, the target area for the purpose of calculation (in other words, simulation) and visualization of the radio wave environment in order to determine and determine the appropriate installation position of the receiver (hereinafter referred to as "Embodiment 1"). In the area (abbreviated as "area"), a wireless transmitter (for example, an access point) as a radio wave transmission source and a receiver (see the radio wave measuring device shown in FIG. 2) for receiving radio waves from the radio wave transmitter are arranged. .. In addition, this area may be an indoor room or a wide area such as an outdoor room.

In the following description, the radio wave environment is defined by the radio wave environment analyzer when radio waves are transmitted (radiated) from a radio transmitter arranged at a transmission point (that is, a position where the above-mentioned wireless transmitter is arranged). It is the reception intensity (an example of reception quality) for each point in the area calculated in the analysis process (in other words, simulation). The reception quality is, for example, the received electric field strength (electric field strength) or the received power.

(Configuration of Radio Wave Environment Analysis Device) FIG. 1 is a block diagram showing a hardware configuration example of the radio wave environment analysis device 100 according to the first embodiment. The radio wave environment analysis device 100 analyzes the radio wave environment in the area ARE1 by using the analysis basic data 7b regarding the area ARE1 in which the transmission point TX1 (see FIG. 3) in which the radio wave transmitter is placed as the radio wave transmission source is located. To execute. The radio wave environment analysis process is a process of calculating the reception quality (see above) by executing a simulation of the radio wave environment when the radio wave from the transmission point is received at the reference point RCV1 (see Fig. 3) in the area ARE1. Is. The radio wave environment analysis device 100 uses analysis result data based on the analysis process (for example, an electric field strength distribution map showing the electric field strength at each point in the area ARE1 of the radio wave from the transmission point). ) Is displayed (see Fig. 6).

Radio environment analysis apparatus 100 includes a processor 1, a ROM (Read Only Memory) 2, a RAM (Random Access Memory) 3, key and Bodo 4, a mouse 5, a display 6, an HDD (Hard Disk Drive) 7 , The configuration includes the input / output interface 8. ROM2, RAM3, keyboard 4, mouse 5, display 6, HDD7 and input / output interface 8 are each connected to the processor 1 by an internal bus or the like so that data or information can be input and output. In FIG. 1, the interface is abbreviated as "I / F" for the sake of simplicity.

The processor 1 is configured by using, for example, a CPU (Central Processing Unit), an MPU (Micro Processing Unit), a DSP (Digital Signal Processor), or an FPGA (Field Programmable Gate Array). The processor 1 functions as a control unit of the radio wave environment analysis device 100, controls processing for overall control of the operation of each part of the radio wave environment analysis device 100, and data or information between each part of the radio wave environment analysis device 100. Input / output processing, data calculation processing, and data or information storage processing. The processor 1 operates according to the program 7a stored in the HDD 7. The processor 1 uses ROM2 and RAM3 when executing the process, acquires the current time information, and outputs the analysis result data 7c generated by the analysis process (see FIG. 5) described later to the display 6 for display. ..

ROM2 is a read-only memory, and stores programs and data of an OS (Operating System), which is basic software, and an application for analysis processing of a radio wave environment in advance. The OS program is executed when the radio wave environment analyzer 100 is started. The application program is started and executed according to the operation of the user of the radio wave environment analysis device 100.

RAM3 is a memory that can be written and read, and is used as a work memory when executing various radio wave environment analysis processes (see Fig. 5), and is used or generated during various radio wave environment analysis processes. Alternatively, the information is temporarily retained.

The keyboard 4 and the mouse 5 as an example of the operation input unit have a function as a human interface with the user, and input the user's operation. In other words, the keyboard 4 and the mouse 5 are used for input or instruction in various processes executed by the radio wave environment analyzer 100.

The display 6 as an example of the display unit is configured by using a display device such as an LCD (Liquid Crystal Display) or an organic EL (Electroluminescence). The display 6 has a function as a human interface with the user, and displays the contents of various settings, the operating state of the radio wave environment analysis device 100, various calculation results, and display data 7d corresponding to the analysis results.

HDD7 as an example of memory is a program 7a for executing the analysis process of the radio wave environment (see Fig. 5), the basic analysis data 7b used in the analysis process of the radio wave environment, and the analysis result by the analysis process of the radio wave environment. The analysis result data 7c corresponding to the above and the display data 7d generated based on the analysis result data 7c are stored. The analysis basic data 7b includes, for example, map or layout data in area ARE1, the number of structures installed in area ARE1 (that is, scatterers that block the progress of radio waves), and the type of each structure (for example). It includes various data or information such as structure data in which the material) and the material constants (for example, reflectance and transmittance) corresponding to the type are associated with each other, and the arrangement position of the wireless transmitter in the area ARE1. In addition, the analysis basic data 7b includes information including the type and number of moving objects (for example, a person, an automated guided vehicle such as an AGV) in the area ARE1.

The radio wave environment analysis processing program 7a in the area ARE1 is read from the HDD 7 to the RAM 3 via the processor 1 and executed by the processor 1. Further, this program 7a may be recorded on a recording medium other than HDD 7 (not shown, for example, DVD-ROM) and read to RAM 3 by a corresponding reading device (not shown, for example, DVD-ROM drive device).

As described above, the analysis basic data 7b used in the analysis processing of the radio wave environment in the area ARE1 specifically includes, for example, the following data or information. (1) Data such as transmission power (dBm), frequency, modulation method, antenna gain and placement position, height of placement position, etc. of radio waves from radio transmitters placed in area ARE1, (2) Area ARE1 Data such as the gain of the antenna of the radio receiver and the height of the location assumed at the point inside (that is, the receiving point of the virtual radio wave), (3) Data related to the two-dimensional or three-dimensional size of area ARE1 (4) The number of structures located in area ARE1, the three-dimensional size of each structure (that is, the scatterer that blocks the progress of radio waves), material constants (eg, transmittance, reflectance) and position (that is, that is). , Structure data associated with (two-dimensional coordinates in the area), (5) Set value data of the lower limit of reception quality (for example, reception power) calculated based on analysis processing (for example, "-100dBm") , (6) Data such as the position of the reference point RCV1 and the height of the reference point RCV1.

The radio wave environment analyzer 100 according to the first embodiment receives radio waves at each point in the area ARE1 based on the above-mentioned analysis basic data 7b, for example, by using a known ray tracing method or a known statistical inference method. The electric field strength can be calculated. Therefore, in the first embodiment, the details of the calculation method of the received electric field strength of the radio wave at the point in the area ARE1 will be omitted.

The input / output interface 8 has a function as an interface for inputting / outputting data or information to / from the radio wave environment analyzer 100, and is, for example, a connector, a connector, and a cable physically connected to the measuring device 11. Etc. are used. In the first embodiment, the radio wave environment analysis device 100 is connected to the measuring device 11 via the input / output interface 8. The cable described above includes, for example, a USB (Universal Serial Bus) cable (not shown).

The measuring device 11 is connected to and from the radio wave measuring device 12 (see FIG. 2) as a receiver for receiving the radio wave transmitted from the wireless transmitter in the area ARE1 via a cable (not shown). The measuring device 11 is also connected to the radio wave environment analysis device 100 via the input / output interface 8. The measuring device 11 measures the received power (in other words, the received radio wave intensity) or the delay spread related to the reception of the radio wave based on the detection output of the radio wave received by the radio wave measuring device 12. When measuring the received power, the measuring device 11 uses, for example, a spectrum analyzer to measure each frequency based on the detection outputs of the horizontally polarized antenna and the vertically polarized antenna arranged on each surface of the radio wave measuring device 12. It is possible to measure the radio field strength of horizontally polarized and vertically polarized waves. Further, when measuring the delay spread, the measuring device 11 uses, for example, a network analyzer based on the detection outputs of the horizontally polarized antenna and the vertically polarized antenna arranged on each surface of the radio wave measuring device 12. It is possible to specify the direction of arrival of the reflected wave and determine whether or not an obstacle (scatterer) such as a wall surface is absorbing radio waves.

The radio wave measuring device 12 is placed at a predetermined height of the reference point RCV1 when the radio wave environment is measured at the reference point RCV1 in the area ARE1. The radio wave measuring device 12 receives the radio wave transmitted from the transmission point TX1 at the reference point RCV1 at each time point when the mobile body MV1 moves by a predetermined distance from the initial placement point (initial position) in the area ARE1. The radio wave measuring device 12 outputs the detection output of the radio wave detected by the reception (for example, characteristics such as the waveform of the received signal) to the measuring device 11. In the first embodiment, the reception strength (for example, electric wave strength) of the radio wave at the reference point RCV1 when the moving body MV1 (see below) exists at each position along the moving route RUT1 is determined by the measuring device 11 and the radio wave. It may be obtained by measurement (actual measurement) using the measuring device 12, or may be obtained by calculation (pinpoint simulation) by the radio wave environment analyzer 100. In the latter case, the configuration of the measuring device 11 and the radio wave measuring device 12 may be omitted.

Here, the shape of the radio wave measuring device 12 will be described with reference to FIG.

FIG. 2 is a perspective view showing the appearance of the radio wave measuring device 12. In the description of the radio wave measuring device 12, the directions of the X-axis, the Y-axis, and the Z-axis follow the directions of the arrows shown in FIG. Specifically, the + X and -X directions are the vertical direction of the housing of the radio wave measuring device 12, and the -Y and + Y directions are the left and right directions of the housing of the radio wave measuring device 12, the -Z direction and the + Z direction. Corresponds to the front-rear direction of the housing of the radio wave measuring device 12.

The radio wave measuring device 12 mainly includes a laminated substrate 13 as an example of a face material and a frame body inside the housing of the radio wave measuring device 12. In the radio wave measuring device 12, the laminated substrate 13 and the frame body form a polyhedral (for example, hexahedral) housing. The housing of the radio wave measuring device 12 is, for example, a hexahedron, and FIG. 2 illustrates a cube. The laminated substrate 13 is screwed to each surface of the cube by, for example, a fixing screw 35.

The face material constituting the housing of the radio wave measuring device 12 is not limited to the laminated substrate 13. Further, the polyhedron is not limited to the hexahedron, and may be, for example, a tetrahedron, a dodecahedron, or the like.

In the radio wave measuring device 12, two sets (two sets of each of the laminated substrate 13 arranged on one upper surface, the laminated substrate 13 arranged on each of the four side surfaces, and the laminated substrate 13 arranged on one lower surface ( One or more sets of antennas are provided. As a result, the radio wave measuring device 12 can receive the incoming radio waves from a total of six directions that match the number (number of surfaces) of the laminated substrates 13. When the lower surface of the radio wave measuring device 12 is fixed to a predetermined mounting surface to measure radio waves, the laminated substrate 13 provided with an antenna may be omitted from the lower surface of the radio wave measuring device 12. Further, in FIG. 2, an antenna provided on the laminated substrate 13 arranged on the above-mentioned upper surface is shown, and an antenna provided on the other surface (specifically, arranged on each of the above-mentioned four side surfaces). The antenna provided on the laminated substrate 13 and the antenna provided on the laminated substrate 13 arranged on one lower surface) are not shown.

The antenna arranged on each laminated substrate 13 is, for example, a dipole antenna. The dipole antenna is formed on, for example, the laminated substrate 13, and the pattern of the dipole antenna is formed by etching the metal foil on the surface or the like. Each of the plurality of layers is composed of, for example, copper foil, glass epoxy, or the like.

Each laminated substrate 13 of the cubic housing of the radio wave measuring device 12 has two sets of antennas, for example, a set of a 2.4 GHz band horizontally polarized antenna 19 and a vertically polarized antenna 21, and a set of 5 GHz band horizontally polarized antennas. A pair of the antenna 23 and the vertically polarized antenna 25 is provided on the surface (upper layer).

The AMC (Artificial Magnetic Conductor) 47 is an artificial magnetic conductor having PMC (Perfect Magnetic Conductor) characteristics, and is formed by a predetermined metal pattern. By using the AMC47, the antenna of the radio wave measuring device 12 can be arranged parallel to the laminated substrate 13, and the overall size can be reduced. In addition, the AMC47 can be prevented from receiving radio waves from other directions by means of a ground conductor, and the gain of the antenna can be increased.

In the radio wave measuring device 12, a plurality of grounding via conductors 61 are provided on the edges of the four sides of the laminated substrate 13 in a straight line along each side. The grounding via conductors 61 may be arranged side by side at equal intervals. Further, each grounding via conductor 61 can shield radio waves from the outside of the radio wave measuring device 12 according to the frequency band (in other words, wavelength) corresponding to the antenna conductor arranged on the laminated substrate 13. It may be provided with a sufficient pitch (interval). The grounding via conductor 61 is provided so as to penetrate from the upper surface to the lower surface of the laminated substrate 13.

In the radio wave measuring device 12, the laminated substrate 13 is formed in, for example, a quadrangular shape. The laminated substrate 13 has a concave portion 73 and a convex portion 75 formed on each side portion in a direction along the side portion, with one step portion 71 provided in the center of the side portion as a boundary. That is, as shown in FIG. 2, the housing of the radio wave measuring device 12 is combined by fitting the concave portion 73 and the convex portion 75 of the adjacent laminated substrates 13 to each other.

FIG. 3 is a plan view schematically showing an example of area ARE1. Area ARE1 is described as a closed space such as a factory, an office, or a public facility. Here, in order to explain in an easy-to-understand manner, the area ARE1 is assumed to be a factory.

In the area ARE1 in the factory, a transmission point TX1 in which a wireless transmitter is arranged is provided on one end side thereof, and a reference point RCV1 serving as a reception point is provided on the other end side opposite to the one end side. Further, between the transmission point TX1 and the reference point RCV1, for example, two types of structures C1 and C2 used in the factory are arranged respectively. Structures C1 and C2 are immovable scatterers (see above) that block the progress of radio waves, such as metal warehouses, wooden desks, and immovable mechanical objects, but are not limited thereto.

In addition, between the transmission point TX1 and the reference point RCV1, along the movement route RUT1 for the moving body MV1 to move by a predetermined distance (so-called interval, for example, 1 m [meter]) from the position P1 to the position P2 at the time of initial placement. And move. The moving body is also a movable scatterer (see above) that blocks the progress of radio waves, and is, for example, a person or an automatic guided vehicle, but is not limited thereto. Here, it is assumed that the moving body MV1 moves every 1 m in a straight line distance of 15 m from the position P1 to the position P2 at the time of initial placement. The moving route RUT1 of the moving body MV1 does not have to be limited to the linear route shown in FIG.

In the first embodiment, the radio wave environment analysis device 100 is used when the radio wave measurement device 12 (see FIG. 2) is placed on the reference point RCV1 and the mobile body MV1 is present at the position P1 at the time of initial placement. , The reception strength of radio waves (for example, electric field strength) at the reference point RCV1 is acquired at each time point when the moving body MV1 moves from the position P1 to the position P2 along the movement route RUT1 by a predetermined distance (for example, 1 m). The radio wave environment analyzer 100 generates the graph shown in FIG. 4A or FIG. 4B by using the received radio wave reception strength (for example, the electric field strength) calculated at the reference point RCV1 obtained for each position of the mobile body MV1.

4A and 4B are graphs showing examples 1 and 2 of changes in the electric field strength with respect to the moving distance of the moving body MV1 at the reference point RCV1 shown in FIG. FIGS. 4A and 4B are the results calculated under conditions in which, for example, the types of structures C1 and C2 (for example, made of wood and metal) and the number of arrangements are different from each other.

The horizontal axis of the graphs shown in FIGS. 4A and 4B shows the moving distance [m] of the moving body MV1, and the vertical axis of the graph shows the electric field strength at the reference point RCV1. When the moving distance of the moving body MV1 is 1 m, it indicates that the moving body MV1 has moved 1 m along the moving route RUT1 from the position P1 (see Fig. 3) at the time of initial placement. Similarly, when the moving distance of the moving body MV1 is 15 m, it indicates that the moving body MV1 has moved 15 m along the moving route RUT1 from the position P1 (see FIG. 3) at the time of initial placement. The position where the moving body MV1 has moved 15 m along the moving route RUT1 is defined as the position P2. Further, the means of moving the mobile body MV1 may be artificially performed or mechanically, and the type may be used.

In the radio wave environment analysis device 100, after the mobile body MV1 has finished moving from the initial position P1 to the final position P2 along the movement route RUT1, before and after one movement of the mobile body MV1, at the reference point RCV1. Compare the electric field strength of each. For example, in the radio wave environment analysis device 100, the electric field strength at the reference point RCV1 when the moving body MV1 exists at the position P1 at the time of initial placement, and immediately after the moving body MV1 moves 1 m along the moving route RUT1 from the position P1. Compare with the electric field strength at the reference point RCV1 at the time of. In addition, the radio wave environment analysis device 100 has the electric field strength at the reference point RCV1 when the moving body MV1 is located at a position where the moving body MV1 has moved 1 m along the moving route RUT1 and the moving body MV1 has moved 2 m along the moving route RUT1. Compare with the electric field strength at the reference point RCV1 when present at the position. Similarly, in the radio wave environment analysis device 100, the electric field strength at the reference point RCV1 when the moving body MV1 exists at a position moved by 14 m along the moving route RUT1 and the moving body MV1 along the moving route RUT1. Compare with the electric field strength at the reference point RCV1 when it exists at the position P2 that has moved 15 m. Hereinafter, for the sake of clarity, the electric field strength at the reference point RCV1 when the moving body MV1 exists at the position before movement is referred to as "pre-movement electric field strength" among the two electric field strengths to be compared. The electric field strength at the reference point RCV1 when the moving body MV1 exists at the position after movement is referred to as "post-movement electric field strength".

The radio wave environment analyzer 100 compares the pre-movement electric field strength and the post-movement electric field strength each time the moving body MV1 moves, and whether the difference between the pre-movement electric field strength and the post-movement electric field strength exceeds a predetermined threshold value. Judge whether or not. When the radio wave environment analyzer 100 determines that the difference between the pre-movement electric field strength and the post-movement electric field strength is equal to or greater than a predetermined threshold value, the radio wave environment analyzer 100 determines the position of the moving body MV1 when the post-movement electric field strength is obtained. It is determined that the position of the moving object (hereinafter referred to as "moving point") to be the target of the overall simulation of the radio wave environment of area ARE1 using the racing method. In other words, when the radio wave environment analyzer 100 determines that the difference between the pre-movement electric field strength and the post-movement electric field strength is less than the predetermined threshold value, the position of the moving body MV1 when the post-movement electric field strength is obtained. Is not adopted for the above-mentioned movement point. This is because even if the moving body MV1 moves by a predetermined distance (for example, 1 m), if the electric field strength of the radio wave at the reference point RCV1 changes only by a minute value less than the threshold value, the electric field strength after the movement is obtained. This is because it is less necessary to adopt the position of the moving body MV1 at the time as a moving point for executing a calculation-intensive overall simulation. That is, if the electric field strength of the radio wave at the reference point RCV1 changes less than the threshold value even if the moving body MV1 moves by a predetermined distance (for example, 1 m), the moving body when the electric field strength after the movement is obtained. By thinning out the position of the MV1, the execution load of the overall simulation of the radio wave environment analyzer 100 can be reduced.

According to the method of adopting the moving point described above, the radio wave environment analysis device 100 performs an overall simulation of each of the positions P1, Pt1, Pt4, Pt6, Pt7, Pt9, Pt10, Pt15 (that is, the position P2) of the moving body MV1. Narrow down (determine) as a movement point to execute. That is, the radio wave environment analysis device 100 moves to execute the entire simulation out of a total of 16 points (points) from the position P1 at the time of initial placement to the position P2 after the end of the movement along the movement route RUT1. Select and narrow down to a total of 8 points.

The position Pt1 is a position where the moving body MV1 has moved 1 m from the position P1 along the moving route RUT1. The position Pt4 is the position where the moving body MV1 has moved 4 m from the position P1 along the moving route RUT1. The position Pt6 is the position where the moving body MV1 has moved 6 m from the position P1 along the moving route RUT1. The position Pt7 is the position where the moving body MV1 has moved 7 m from the position P1 along the moving route RUT1. The position Pt9 is the position where the moving body MV1 has moved 9 m from the position P1 along the moving route RUT1. The position Pt10 is the position where the moving body MV1 has moved 10 m from the position P1 along the moving route RUT1. The position Pt15 (that is, the position P2) is the position where the moving body MV1 has moved 15 m from the position P1 along the moving route RUT1.

For example, the types of structures C1 and C2 arranged in the area ARE1 are different between the graph shown in FIG. 4A and the graph shown in FIG. 4B. Similarly, in FIG. 4B, according to the method of adopting the moving point described above, in the radio wave environment analysis device 100, the position of the moving body MV1 is the position P1, Pt1, Pt3, Pt4, Pt6, Pt8, Pt10, Pt15 (that is, the position P2). Narrow down (determine) each as a moving point to run the overall simulation. That is, the radio wave environment analysis device 100 moves to execute the entire simulation out of a total of 16 points (points) from the position P1 at the time of initial placement to the position P2 after the end of the movement along the movement route RUT1. Select and narrow down to a total of 8 points.

(Operation of Radio Wave Environment Analysis Device) Next, the operation of the radio wave environment analysis device 100 according to the first embodiment will be described with reference to FIG. FIG. 5 is a flowchart showing an example of the operation procedure of the radio wave environment analysis device 100. Each process (step) of the operation shown in FIG. 5 is mainly executed by the processor 1 of the radio wave environment analysis device 100.

In FIG. 5, the radio wave environment analysis device 100 calculates the electric field strength at the reference point RCV1 of the radio wave transmitted from the transmission point TX1 when the mobile body MV1 exists at the position P1 at the time of initial placement in the area ARE1. (St1). The calculation of the electric field strength at the reference point RCV1 is a process of calculating the electric field strength only in the periphery including the reference point RCV1 by simulation (in other words, a process of simulating small). The small simulation process is a simulation process in which the target area of the calculation process is limited to the periphery of the reference point RCV1 instead of the entire area ARE1. According to this small simulation process, it is possible to avoid an increase in the load of the radio wave environment analysis device 100 due to a large amount of calculation when the entire area ARE1 is simulated. The electric field strength at the reference point RCV1 may be acquired by the above-mentioned calculation (small simulation process) or by actual measurement using the measuring device 11 and the radio wave measuring device 12 (see FIG. 1). , The same applies to the subsequent embodiments.

Next, when the moving body MV1 moves from the position P1 at the time of initial placement to a predetermined distance (for example, 1 m) along the moving route RUT1 in the area ARE1, the radio wave environment analysis device 100 similarly at the reference point RCV1. Calculate the electric field strength of radio waves (St2).

If the mobile MV1 has not reached the final point along the travel route RUT1 (ie position P2) (St3, NO), the mobile MV1 has not reached the final point along the travel route RUT1 (ie position P2). The radio wave environment analyzer 100 repeatedly calculates the electric field strength at the reference point RCV1 when it exists at the remaining position (point) of the moving body MV1 (St2).

On the other hand, when the moving body MV1 reaches the final point (that is, the position P2) along the moving route RUT1 (St3, YES), the radio wave environment analyzer 100 uses the reference before and after one movement of the moving body MV1. Compare the respective electric field strengths at point RCV1 (St4). The radio wave environment analyzer 100 compares the pre-movement electric field strength and the post-movement electric field strength each time the moving body MV1 moves, and whether the difference between the pre-movement electric field strength and the post-movement electric field strength exceeds a predetermined threshold value. Judge whether or not (St4). When the radio wave environment analyzer 100 determines that the difference between the pre-movement electric field strength and the post-movement electric field strength is equal to or greater than a predetermined threshold value, the radio wave environment analyzer 100 determines the position of the moving body MV1 when the post-movement electric field strength is obtained. Determined as the moving point of the moving body MV1 to be subjected to the overall simulation of the radio wave environment of area ARE1 using the racing method (see St4, Fig. 4A or Fig. 4B).

After step St4, the radio wave environment analyzer 100 executes a calculation of the entire simulation of the radio wave environment of the area ARE1 when the mobile body MV1 exists at the position P1 at the time of initial placement (St5). Further, the radio wave environment analysis device 100 determines the entire radio wave environment of the area ARE1 when the moving body MV1 exists at each moving point (for example, a total of eight in the example of FIG. 4A) determined in step St4. Perform each simulation calculation (St6).

If the calculation of the overall simulation of the radio wave environment in area ARE1 when the mobile MV1 exists at the final movement point has not been completed (St7, NO), when the mobile MV1 exists at the final movement point. Until the calculation of the overall simulation of the radio wave environment of area ARE1 is completed, the radio wave environment analyzer 100 executes the calculation of the overall simulation of the radio wave environment of area ARE1 when the mobile body MV1 exists at the remaining movement points. (St6).

On the other hand, when the calculation of the overall simulation of the radio wave environment of the area ARE1 when the moving body MV1 exists at the final moving point is completed (St7, YES), the radio wave environment analyzer 100 is executed in step St6. The execution results (see Fig. 6) of the overall simulation of the radio wave environment of the series of areas ARE1 obtained for each movement point of the mobile body MV1 are continuously displayed on the display 6 (St8).

FIG. 6 is a diagram showing an example of an overall simulation result of the radio wave environment in the area ARE1 corresponding to the position of the mobile body MV1 shown in FIG. Figure 6 shows the execution result of the overall simulation of the radio wave environment of area ARE1 while the mobile body MV1 is moving along the movement route RUT1, and the radio wave environment of area ARE1 when the mobile body MV1 moves to the final position P2. The execution result of the whole simulation is shown exemplarily. In the execution result of each overall simulation, the positions of the transmission point TX1, the moving body MV1, and the reference point RCV1 are clearly shown, and are shown in grayscale so that the electric field strength (reception strength) of the radio wave can be understood. ing.

In Fig. 6, at time T = t1, the execution result of the overall simulation of the radio wave environment of area ARE1 when the moving body MV1 moves 1 m along the movement route RUT1 from the position P1 at the time of initial placement (see Fig. 4A) is shown. Has been done. The reception strength (electric field strength) of radio waves is high near the transmission point TX1, and not only is the distance from the transmission point TX1 at the reference point RCV1, but also the effects of radio wave scattering by the structures C1 and C2 and the moving body MV1. In response to this, the reception strength (electric field strength) is relatively low.

In addition, at time T = t2, the execution result of the overall simulation of the radio wave environment of area ARE1 when the moving body MV1 moves 6 m along the movement route RUT1 from the position P1 at the time of initial placement (see Fig. 4A) is shown. There is. Even at time T = t2, the reception strength (electric field strength) of radio waves is high near the transmission point TX1, and at the reference point RCV1, not only is the distance from the transmission point TX1 far, but also the radio waves from the structures C1 and C2 and the moving body MV1 respectively. The reception strength (electric field strength) is relatively low due to the influence of scattering and the like.

In addition, at time T = t3, the execution result of the overall simulation of the radio wave environment of area ARE1 when the moving body MV1 moves 9 m along the movement route RUT1 from the position P1 at the time of initial placement (see Fig. 4A) is shown. There is. Even at time T = t3, the reception strength (electric field strength) of radio waves is high near the transmission point TX1, and at the reference point RCV1, not only is the distance from the transmission point TX1 far, but also the radio waves from the structures C1 and C2 and the moving body MV1 respectively. The reception strength (electric field strength) is relatively low due to the influence of scattering and the like.

In addition, at time T = t4, the execution result of the overall simulation of the radio wave environment of area ARE1 when the moving body MV1 moves 15 m along the movement route RUT1 from the position P1 at the time of initial placement (see Fig. 4A) is shown. There is. Even at time T = t4, the reception strength (electric field strength) of radio waves is high near the transmission point TX1, and at the reference point RCV1, not only is the distance from the transmission point TX1 far, but also the radio waves from the structures C1 and C2 and the moving body MV1 respectively. The reception strength (electric field strength) is relatively low due to the influence of scattering and the like.

As described above, the radio wave environment analysis device 100 according to the first embodiment has the position information of the radio transmitter arranged in the area ARE1 in which the mobile body MV1 exists and the reference point RCV1 at which the radio wave from the radio transmitter is received. The location information and the location information are stored in HDD7. In the radio wave environment analyzer 100, the reception intensity of radio waves at the reference point RCV1 when the mobile body MV1 is in the initial position, and each movement of the mobile body MV1 by a predetermined distance (for example, 1 m) from the initial position a plurality of times. Calculate the reception intensity of radio waves at the reference point RCV1 at the time point. The radio wave environment analysis device 100 determines the position (movement point) of the mobile body MV1 for executing the simulation of the radio wave environment in the area ARE1 based on the reception intensity of the radio wave at the reference point RCV1 at each position of the mobile body MV1. Select.

As a result, the radio wave environment analysis device 100 can be used when the moving body MV1 exists at each position of the moving route RUT1 where the moving body MV1 is expected to move in the actual environment of the area ARE1 such as a factory where the moving body MV1 exists. By using the electric field strength of the reference point RCV1, it is possible to efficiently narrow down some of the moving points that are effective for the calculation of the overall simulation of the radio wave environment from all the moving points where the moving body MV1 can exist. Therefore, since the radio wave environment analysis device 100 can suppress an increase in the number of calculations for performing the overall simulation of the radio wave environment, the analysis process of the overall simulation of the radio wave environment can be executed at an early stage.

Further, the radio wave environment analysis device 100 executes an overall simulation of the radio wave environment under the condition that the moving body MV1 exists at each of the selected one or more positions. As a result, the radio wave environment analysis device 100 can execute an overall simulation of the radio wave environment after considering the influence of radio wave scattering by the mobile body MV1 existing in the area ARE1, and the reception strength of the radio wave at the reference point RCV1. Can be obtained with high accuracy.

Further, the radio wave environment analysis device 100 continuously displays the execution result of the entire simulation of the radio wave environment in the area ARE1 on the display 6 for each position of the mobile body MV1. As a result, the observer of the radio wave environment can see the reception strength of the radio wave in the entire area ARE1 including the reception strength of the radio wave at the reference point RCV1 from a bird's-eye view while checking the difference depending on the position of the moving body MV1 during the moving process. Can be grasped.

Further, the radio wave environment analysis device 100 uses the reception intensity of radio waves at the reference point RCV1 when the mobile body MV1 is present at the immediately preceding position and the reference point RCV1 when the mobile body MV1 is present at the position immediately after the movement. The position of the moving body MV1 for executing the overall simulation is selected according to the difference between the reception intensity of the radio wave and the threshold value. As a result, if the electric field strength of the radio wave at the reference point RCV1 changes by less than the threshold value even if the moving body MV1 moves by a predetermined distance (for example, 1 m), the movement when the electric field strength is obtained after the movement. By thinning out the position of the body MV1, the execution load of the entire simulation of the radio wave environment analyzer 100 can be reduced.

Further, the radio wave environment analysis device 100 acquires the reception intensity of the radio wave at the reference point RCV1 by simulation (calculation). As a result, the radio wave environment analyzer 100 can be easily acquired by simulation (calculation) based on the execution processing of the simulation program without measuring the reception intensity of the radio wave at the reference point RCV1, so that the entire area ARE1 is targeted. A series of processes from the execution of the entire simulation of the radio wave environment to the display of the result can be efficiently executed by the calculation by the radio wave environment analyzer 100.

Further, the radio wave environment analysis device 100 acquires the reception intensity of the radio wave at the reference point RCV1 by actual measurement. As a result, the radio wave environment analysis device 100 can accurately acquire the reception strength (for example, electric wave strength) of the radio wave at the reference point RCV1 by the measuring device 11 and the radio wave measuring device 12, so that the radio wave for the entire area ARE1 is covered. The execution result of the entire environment simulation can be acquired with high accuracy.

&lt;Embodiment 2&gt; In the first embodiment, the case where the mobile MV1 existing in the area ARE1 is single has been described. In the second embodiment, it is assumed that there are a plurality of moving objects existing in the area ARE2 (see FIG. 7). In order to make the explanation easy to understand, in the second embodiment, it is assumed that two mobile bodies MV1 and MV2 exist in the area ARE2.

Since the configuration of the radio wave environment analysis device according to the second embodiment is the same as the configuration of the radio wave environment analysis device 100 according to the first embodiment, the same reference numerals are given to the same configuration to simplify the explanation. It will be omitted and different contents will be explained.

FIG. 7 is a diagram showing an operation outline example of the radio wave environment analysis device 100 according to the second embodiment. In the second embodiment, the area ARE2 in which the transmission point TX1, the structures C1 and C2 and the reference point RCV1 are arranged in the same environment as the area ARE1 according to the first embodiment (for example, a closed space such as a factory or an office) is set. It will be explained with reference to. Note that in FIG. 7, the structures C1 and C2 are not shown. The mobile bodies MV1 and MV2 may be the same as those of the mobile body MV1 according to the first embodiment.

In the second embodiment, the mobile bodies MV1 and MV2 move, for example, 100 times along their respective movement routes. In other words, since there are a total of 10000 (= 100 × 100) combinations of points after the movement of the mobile bodies MV1 and VM2, the radio wave environment analysis device 100 is assumed to be each of the mobile bodies MV1 and MV2 in the area ARE2. If the entire simulation of the radio wave environment in area ARE2 is performed after considering all the movement patterns of, the calculation will be performed 10,000 times. In other words, the load at the time of executing the overall simulation of the radio wave environment analysis device 100 increases.

Therefore, in the second embodiment, when each of the mobile bodies MV1 and MV2 moves in 100 different movement patterns, the radio wave environment analysis device 100 moves only one of the plurality of mobile bodies, and the other. It is considered that all one or more moving objects of the above are stopped, and the moving points for executing the whole simulation are narrowed down for the moving objects to be moved in the same manner as in the first embodiment. Similarly, the radio wave environment analysis device 100 also considers that the one or more mobile bodies other than the above-mentioned other mobile bodies are all stopped, and the first embodiment. In the same way, for the moving object to be moved, the moving points for executing the overall simulation are narrowed down.

For example, to explain with reference to FIG. 7, the radio wave environment analysis device 100 first considers that only the moving body MV1 is moving and the other moving body MV2 is stopped, and targets 100 movement patterns of the moving body MV1. In the same manner as in the first embodiment, the movement points for executing the overall simulation are narrowed down. For example, suppose that 10 movement points are narrowed down (selected) out of 100 movement patterns of the moving body MV1 (see FIG. 8A). FIG. 8A is a graph showing an example of a change in the electric field strength with respect to the moving distance of the moving body MV1 at the reference point RCV1 shown in FIG. The horizontal axis of the graph shown in FIG. 8A shows the moving distance [m] of the moving body MV1, and the vertical axis of the graph shows the electric field strength at the reference point RCV1. Note that FIG. 8A shows a part of the total moving distance of the moving body MV1 up to 15 m out of a total of 100 m.

As shown in FIG. 8A, the radio wave environment analyzer 100 performs an overall simulation for each of the positions Pt1a, Pt4a, Pt6a, Pt7a, Pt8a, Pt9a, Pt10a, Pt12a, Pt14a, and Pt15a of the mobile body MV1. Narrow down (determine) as a movement point of. In the present embodiment, for the sake of simplification of the explanation, the case where 10 points are selected within the moving distance of 15 m of the moving body MV1 is shown, but 10 points may be selected during the moving distance of 100 m. .. That is, the radio wave environment analysis device 100 is for executing the entire simulation out of a total of 100 points (points) from the position P11 at the time of initial placement to the position P12 after the end of movement along the predetermined movement route by the moving body MV1. Select and narrow down the movement points (for example, 10 points).

Next, the radio wave environment analysis device 100 considers that only the moving body MV2 is moving and the other moving body MV1 is stopped, and performs the same as the first embodiment for 100 movement patterns of the moving body MV2. To narrow down the movement points for executing the overall simulation. For example, suppose that eight movement points are narrowed down (selected) out of 100 movement patterns of the moving body MV2 (see FIG. 8B). FIG. 8B is a graph showing an example of changes in the electric field strength with respect to the moving distance of the moving body MV2 at the reference point RCV1 shown in FIG. The horizontal axis of the graph shown in FIG. 8B shows the moving distance [m] of the moving body MV2, and the vertical axis of the graph shows the electric field strength at the reference point RCV1. Note that FIG. 8B shows a part of the total moving distance of the moving body MV2 up to 15 m out of a total of 100 m.

As shown in FIG. 8B, the radio wave environment analyzer 100 uses each of the positions Pt1b, Pt5b, Pt6b, Pt9b, Pt10b, Pt11b, Pt12b, and Pt15b of the moving body MV2 as moving points for executing the overall simulation. Narrow down (decide). In the present embodiment, for the sake of simplification of the explanation, the case where 8 points are selected within the moving distance of 15 m of the moving body MV2 is shown, but 8 points may be selected during the moving distance of 100 m. .. That is, the radio wave environment analysis device 100 is for executing the entire simulation out of a total of 100 points (points) from the position P21 at the time of initial placement of the moving body MV2 to the position P22 after the end of movement along the predetermined movement route. Select and narrow down the movement points (for example, 8 points).

Therefore, in the second embodiment, the radio wave environment analysis device 100 assumes the number of moving points (10) selected assuming that only the moving body MV1 moves, and the case where only the moving body MV2 moves. The product (that is, 80) with the number of movement points (8) selected in the above calculation is calculated as the movement points for executing the overall simulation. In other words, the radio wave environment analysis device 100 does not need to perform the above-mentioned 10,000 overall simulations, and the reception intensity of radio waves at the reference point RCV1 is likely to fluctuate due to the movement of the moving body. Since the entire simulation needs to be executed by the amount, the increase in the number of executions of the overall simulation can be further reduced.

(Operation of Radio Wave Environment Analysis Device) Next, the operation of the radio wave environment analysis device 100 according to the second embodiment will be described with reference to FIG. FIG. 9 is a flowchart showing an example of the operation procedure of the radio wave environment analysis device 100. Each process (step) of the operation shown in FIG. 5 is mainly executed by the processor 1 of the radio wave environment analysis device 100. Further, in the description of FIG. 9, the same step number is assigned to the process overlapping with FIG. 5 to simplify or omit the description, and different contents will be described.

In FIG. 9, the radio wave environment analysis device 100 uses the radio wave environment analysis device 100 as a reference point RCV1 for radio waves transmitted from the transmission point TX1 when the plurality of mobile bodies MV1 and MV2 are located at positions P11 and P21 at the time of initial placement in the area ARE2. Perform the calculation of the electric field strength in (St11). Next, the radio wave environment analyzer 100 considers that only one moving body (for example, moving body MV1) has moved in the area ARE2, and the other one or more moving bodies (for example, moving body MV2) has stopped. Similarly, when the moving body MV1 to be moved is moved from the position P11 at the time of initial placement to a predetermined distance (for example, 1 m) along a predetermined movement route, the electric wave field strength at the reference point RCV1 is calculated ( St12).

It is assumed that the electric field strength of the radio wave at the reference point RCV1 when each of the moving objects MV1 and MV2 to be moved reaches the final point along the own movement route is not calculated (St13, NO). In this case, the radio wave environment analyzer until the electric field strength of the radio wave at the reference point RCV1 when each of the moving objects MV1 and MV2 to be moved reaches the final point along their own movement route is calculated. 100 repeats the calculation of the electric field strength at the reference point RCV1 when only one of the moving objects is the target of movement (St12). For example, after the electric field strength of the radio wave at the reference point RCV1 when reaching the final point along the movement route of the moving body MV1 to be moved is calculated, the radio wave environment analyzer 100 uses another moving body (for example, The moving body MV2) is regarded as the moving target, and one or more other moving bodies (for example, the moving body MV1) are regarded as stopped, and the moving body MV2 to be moved is determined along the predetermined movement route from the position P21 at the time of initial placement. When moving about a distance (for example, 1 m), the electric wave field strength at the reference point RCV1 is calculated in the same way (St12).

When the electric field strength of the radio wave at the reference point RCV1 when each of the moving objects MV1 and MV2 to be moved reaches the final point along their own movement route is calculated (St13, YES), the radio wave environment. The analyzer 100 compares the electric field strengths at the reference point RCV1 before and after one movement for each position of the moving body MV1 when only the moving body MV1 is the target of movement (St14). In the same manner as in the first embodiment, the radio wave environment analyzer 100 sets the position of the moving body MV1 when the difference between the pre-movement electric field strength and the post-movement electric field strength is equal to or more than a predetermined threshold value in the radio wave environment of the area ARE2. Determined as the moving point of the moving body MV1 for which the overall simulation is to be performed (St14, see Fig. 8A).

Similarly, the radio wave environment analysis device 100 compares the electric field strengths at the reference point RCV1 before and after one movement for each position of the moving body MV2 when only the moving body MV2 is the moving target (St14). ). In the same manner as in the first embodiment, the radio wave environment analyzer 100 sets the position of the moving body MV2 when the difference between the pre-movement electric field strength and the post-movement electric field strength is equal to or more than a predetermined threshold value in the radio wave environment of the area ARE2. Determined as the moving point of the moving body MV1 for which the overall simulation is to be performed (St14, see Fig. 8B).

The radio wave environment analyzer 100 is the product of the number of moving points selected assuming that only the moving body MV1 moves and the number of moving points selected assuming that only the moving body MV2 moves. Is calculated as the number of movement points for executing the overall simulation (St14), and the process proceeds to step St5. Since the processing after step St5 in FIG. 9 is the same as the processing after step St5 in the first embodiment described with reference to FIG. 5, the description thereof will be omitted.

As described above, the radio wave environment analysis device 100 according to the second embodiment is the first mobile body (for example, the mobile body MV1) among the plurality of mobile bodies MV1 and MV2 when a plurality of mobile bodies exist in the area ARE2. Acquires the reception strength of radio waves at the reference point RCV1 for each movement a predetermined number of times. The radio wave environment analysis device 100 acquires the reception intensity of radio waves at the reference point RCV1 for each movement of the second mobile body (for example, the mobile body MV2) among the plurality of mobile bodies MV1 and MV2 a predetermined number of times. The radio wave environment analyzer 100 selects the respective positions of the plurality of mobile bodies MV1 and MV2 for executing the simulation of the radio wave environment in the area ARE2 based on the reception intensity of the radio wave at each of the above-mentioned reference points RCV1. ..

As a result, the radio wave environment analysis device 100 does not need to execute the same number of total simulations as the number of movement patterns (for example, 10000 described above) when each of the plurality of mobile bodies MV1 and MV2 moves, and the reference point RCV1 Since it is sufficient to execute the overall simulation for a total of 80 moving points where the reception intensity of the radio waves in the above is likely to fluctuate due to the movement of the moving body, the increase in the number of executions of the overall simulation can be further reduced.

Although various embodiments have been described above with reference to the drawings, it goes without saying that the present disclosure is not limited to such examples. It is clear that a person skilled in the art can come up with various modification examples, modification examples, replacement examples, addition examples, deletion examples, and equal examples within the scope of the claims, and of course, these are also examples. It is understood that it belongs to the technical scope of the present disclosure. Further, each component in the various embodiments described above may be arbitrarily combined as long as the gist of the invention is not deviated.

The present disclosure is a radio wave environment analyzer that suppresses an increase in the number of calculations for the overall simulation of the radio wave environment for the target area where a moving object exists in the actual environment, and efficiently executes the analysis processing of the overall simulation of the radio wave environment. It is useful as a radio wave environment analysis method.

1 Processor 2 ROM 3 RAM 4 Keyboard 5 Mouse 6 Display 7 HDD 7a Program 7b Analysis basic data 7c Analysis result data 7d Display data 8 Input / output interface 11 Measuring device 12 Radio wave measuring device 100 Radio wave environment analyzer TX1 Transmission point RCV1 Reference point MV1 , MV2 mobile ARE1, ARE2 area