Radio environment model calculation system and radio environment model calculation method

Abstract

This radio environment model calculation system generates a structure polygon representing a stationary structure from point cloud data relating to the stationary structure and electrical data representing electrical characteristics of the stationary structure. Also, the radio environment model calculation system generates a moving body polygon representing a moving body from point cloud data relating to the moving body. Then, the radio environment model calculation system acquires a first electric field intensity distribution based on the structure polygon from an electromagnetic field calculation engine. Also, the radio environment model calculation system acquires a second electric field intensity distribution based on the moving body polygon from the electromagnetic field calculation engine. Then, the radio environment model calculation system generates an electric field intensity distribution on the basis of the first electric field intensity distribution and the second electric field intensity distribution, and outputs the electric field intensity distribution from a display device.

Description

Radio wave environment model calculation system and radio wave environment model calculation method

[0001] The present invention relates to a radio wave environment model calculation system and a radio wave environment model calculation method.

[0002] The increasing speed and integration of semiconductor chips has made it possible to perform large-scale, high-speed electromagnetic field calculations using computer resources. A technology called digital twin has emerged, in which objects in the real world that affect electromagnetic waves are modeled within computer resources, and this model is used to reproduce wireless communication characteristics in the real world within a computer, and research and development is currently underway.

[0003] Until now, a technology has been adopted to reproduce structures that affect the electromagnetic field within a wireless communication area in cyberspace within computer resources, by constructing a three-dimensional structure in cyberspace using size data and electrical characteristic data of the structure.

[0004] However, when a mobile object exists within a wireless communication area, the influence of the mobile object on the electromagnetic field within the wireless communication area must be reflected in the cyberspace within the computer resources.

[0005] To address this issue, Patent Document 1 discloses a technology that measures the electromagnetic field at multiple points within a wireless communication area and corrects the electromagnetic field distribution within the area based on the results of calculations using structural data in cyberspace.

[0006] Patent Literature 2 discloses a technology for detecting the presence or absence of a moving object from actual measured values ​​of the electromagnetic field at a set of multiple transmitting and receiving points within a wireless communication area. Then, physical and electrical properties, such as the position, of the moving object present between the transmitting and receiving points are estimated using the difference between the measured values ​​when the moving object is not present and the measured values ​​when the moving object is present. The technology then discloses a technology for calculating the electromagnetic field distribution within the wireless communication area using the estimated physical and electrical attributes of the moving object.

[0007] International Publication No. 2020 / 195296 Japanese Patent Application Laid-Open No. 2023-72230

[0008] However, the conventional technologies of Patent Documents 1 and 2 described above have a problem in that it is difficult to accurately predict the radio wave environment within a wireless communication service area by faithfully reproducing in cyberspace structures that affect electromagnetic waves, such as wireless communication media, that exist within the wireless communication service area.Furthermore, it is also difficult to predict fluctuations in the radio wave environment within the wireless communication service area in response to changes in the position of a mobile object within the wireless communication service area.

[0009] As one aspect for solving the above problem, there is provided a radio wave environment model calculation system for calculating an electric field strength distribution in a wireless communication service area in which stationary structures and mobile bodies are present, the radio wave environment model calculation system having a processor and a memory, wherein the processor generates a structure polygon representing the stationary structure from point cloud data relating to the stationary structure and electrical data representing the electrical characteristics of the stationary structure, generates a mobile body polygon representing the mobile body from the point cloud data relating to the mobile body, obtains a first electric field strength distribution based on the structure polygon from an electromagnetic field calculation engine, obtains a second electric field strength distribution based on the mobile body polygon from the electromagnetic field calculation engine, generates the electric field strength distribution based on the first electric field strength distribution and the second electric field strength distribution, and outputs the electric field strength distribution from a display device.

[0010] According to the present invention, it is possible to quickly and accurately estimate communication quality within a service area including mobile objects that provide wireless communication, and it is possible to quickly and accurately estimate wireless communication quality in a communication environment including mobile objects by following the movement of the mobile objects.

[0011] 1 is a diagram showing the configuration of a radio wave environment model calculation system according to embodiment 1. FIG. 2 is a flowchart showing main operation processing of the radio wave environment model calculation system according to embodiment 1. FIG. 3 is a flowchart showing electromagnetic field calculation processing in main operation processing of the radio wave environment model calculation system according to embodiment 1. FIG. 4 is a diagram showing the configuration of a radio wave environment model calculation system according to a modified example of embodiment 1. FIG. 5 is a diagram showing the configuration of a radio wave environment model calculation system according to embodiment 2. FIG. 6 is a flowchart showing main operation processing of the radio wave environment model calculation system according to embodiment 2. FIG. 7 is a flowchart showing direct wave calculation processing in main operation processing of the radio wave environment model calculation system according to embodiment 2. FIG. 8 is a flowchart showing reflected wave calculation processing in main operation processing of the radio wave environment model calculation system according to embodiment 2. FIG. 9 is a flowchart showing main operation processing of the radio wave environment model calculation system according to embodiment 3. FIG. 10 is a flowchart showing moving object point cloud measurement / data generation processing in main operation processing of the radio wave environment model calculation system according to embodiment 3. FIG. 11 is a diagram showing the configuration of a radio wave environment model calculation system according to embodiment 4. FIG. 12 is a flowchart showing main operation processing of the radio wave environment model calculation system according to embodiment 4. FIG. 13 is a flowchart showing moving object point cloud measurement / data generation processing in main operation processing of the radio wave environment model calculation system according to embodiment 4. FIG. 14 is a diagram for explaining the operation of the radio wave environment model calculation system according to example 1. FIG. 1 is a diagram for explaining the operation of the radio wave environment model calculation system according to Example 1. FIG. 2 is a diagram for explaining the operation of the radio wave environment model calculation system according to Example 1. FIG. 3 is a diagram for explaining the operation of the radio wave environment model calculation system according to Example 2. FIG. 4 is a diagram for explaining the operation of the radio wave environment model calculation system according to Example 2. FIG. 5 is a diagram for explaining the operation of the radio wave environment model calculation system according to Example 2. FIG. 6 is a diagram for explaining the operation of the radio wave environment model calculation system according to Example 2. FIG. 7 is a diagram for explaining the operation of the radio wave environment model calculation system according to Example 3. FIG. 8 is a diagram for explaining the operation of the radio wave environment model calculation system according to Example 3. FIG. 9 is a diagram for explaining the operation of the radio wave environment model calculation system according to Example 3. FIG. 10 is a diagram for explaining the operation of the radio wave environment model calculation system according to Example 3.FIG. 10 is a diagram for explaining the operation of the radio wave environment model calculation system according to Example 4. FIG. 11 is a diagram for explaining the operation of the radio wave environment model calculation system according to Example 4. FIG. 12 is a diagram for explaining the operation of the radio wave environment model calculation system according to Example 4. FIG. 13 is a diagram for explaining the operation of the radio wave environment model calculation system according to Example 5. FIG. 14 is a diagram for explaining the operation of the radio wave environment model calculation system according to Example 5. FIG. 15 is a diagram for explaining the operation of the radio wave environment model calculation system according to Example 5. FIG. 16 is a diagram for explaining the operation of the radio wave environment model calculation system according to Example 6. FIG. 17 is a diagram for explaining the operation of the radio wave environment model calculation system according to Example 7. FIG. 18 is a diagram for explaining the operation of the radio wave environment model calculation system according to Example 7. FIG. 19 is a diagram for explaining the operation of the radio wave environment model calculation system according to Example 9. FIG. 19 is a diagram showing an example of the hardware configuration of a computer.

[0012] Hereinafter, embodiments of the present application will be described with reference to the drawings. Note that the embodiments described below do not limit the invention according to the claims, and not all of the elements and combinations thereof described in the embodiments are necessarily essential to the solution of the invention.

[0013] In the following description, the programs that realize each processing function unit are executed by a processor to perform a predetermined process using a storage resource (e.g., a random access memory (RAM)) and / or a communication interface device (e.g., a port). The processor is, for example, a central processing unit (CPU). Therefore, the process executed by each processing function unit may be a process performed by a processor or a computer having that processor.

[0014] In the following embodiments and examples, explanations of matters that overlap with previously described embodiments or examples will be omitted, and the differences will be mainly described. Furthermore, in the following embodiments and examples, a combination of part or all of one embodiment or example with part or all of another embodiment or example is also included in the embodiments of the present application as long as there is no contradiction and consistency.

[0015] In the following description, identical or similar components are given the same reference numerals, and in later embodiments and modifications, their description may be omitted or only the differences may be described. Furthermore, when there are multiple identical or similar components, they may be described with the same reference numerals but with different subscripts. Furthermore, when there is no need to distinguish between these multiple components, the subscripts may be omitted. The number of each component may be singular or plural unless otherwise specified.

[0016] The following embodiments and examples are applied to the calculation of a radio wave environment model for automatic driving control of a vehicle, which is a moving body, but are not limited to this and can be widely applied to constructing a model of a communication radio wave environment in an environment that includes both stationary and moving bodies.

[0017] [Embodiment 1] (Configuration of a radio wave environment model calculation system 1S according to embodiment 1) Fig. 1A is a diagram showing the configuration of a radio wave environment model calculation system 1S according to embodiment 1. The radio wave environment model calculation system 1S includes an electromagnetic field calculation engine 510, a calculation control device 520, a calculation model generation device 530, a storage device 540, an input device 550, a display device 560, a point cloud acquisition device 601, and a moving object detection device 602.

[0018] The point cloud acquisition device 601 acquires point cloud data related to stationary structures and stores it in the storage device 540 as structure shape data 542. The moving body detection device 602 acquires point cloud data related to moving bodies and stores it in the storage device 540 as moving body shape data 541. The moving body detection device 602 is an optical point cloud measurement device such as LiDAR (Light Detection And Ranging).

[0019] The calculation model generating device 530 converts the structure shape data 542 into structure polygon data 531 using structure electrical data 544 stored in advance in the storage device 540. The calculation model generating device 530 also converts the moving body shape data 541 into moving body polygon data 532.

[0020] A polygon rearrangement function unit 521 of the calculation control device 520 uses structure polygon data 531 and moving object polygon data 532 to generate polygon data that is spatially arranged in order of ID so that the distance between polygons is minimized. A ray emission point setting function unit 522 of the calculation control device 520 determines a ray emission point from a ray emission point 552 input to an input device 550. A receiving area setting function unit 523 of the calculation control device 520 determines a receiving area forming polygon surface and ID-assigned polygon data to which an ID has been assigned from a receiving area 551 input to the input device 550.

[0021] The electromagnetic field calculation engine 510 calculates the electromagnetic field distribution within the wireless communication service area using the ray emission points, reception area forming polygon surface, and ID-attached polygon data determined as described above, and generates a field intensity distribution 561 and a propagation ray 562.

[0022] The display device 560 displays a field intensity distribution 561 and a propagation ray 562. The display device 560 also uses the mobile object shape data 541, the structure shape data 542, and the structure electrical data 544 stored in the storage device 540 to graphically output a mobile object 563 and a structure 564 within the wireless communication service area.

[0023] (Main Operation Processing of Radio Wave Environment Model Calculation System 1S According to First Embodiment) FIG. 1B is a flowchart showing main operation processing of the radio wave environment model calculation system 1S according to the first embodiment.

[0024] First, in step S11, the calculation model generating device 530 reads the structure point cloud data (structure shape data 542). Next, in step S12, the calculation model generating device 530 generates a structure polygon (structure polygon data 531) based on the structure shape data 542.

[0025] Next, in step S13, the computational model generating device 530 reads the moving body point cloud data (moving body shape data 541). At this time, the computational model generating device 530 also reads the structure electrical data 544. Next, in step S14, the computational model generating device 530 generates a moving body polygon (moving body polygon data 532) based on the moving body shape data 541 and the structure electrical data 544.

[0026] Next, in step S15, the calculation control device 520 generates a congruent polygon data structure using the structure polygon data 531 and the moving object polygon data 532, and stores the data in the polygon rearrangement function unit 521. The congruent polygon data is a polygon that includes structure polygons and moving object polygons.

[0027] Next, in step S16, the calculation control device 520 accepts input of a receiving area 551 from the input device 550. Next, in step S17, the calculation control device 520 generates a receiving surface polygon from the receiving area 551 input in step S16 and stores it in the receiving area setting function unit 523. The receiving surface polygon is a polygon that represents the receiving surface of a ray in the receiving area 551 set by the user.

[0028] Next, in step S 18 , the calculation control device 520 receives input of the ray emission point 552 from the input device 550 , creates positional relationship data between the ray emission point and the receiving surface polygon, and stores it in the ray emission point setting function unit 522 .

[0029] Next, in step S19, the electromagnetic field calculation engine 510 reads the congruent polygon data, receiving surface polygons, and data related to ray emission points from the calculation control device 520 via the polygon rearrangement function unit 521, receiving area setting function unit 523, and ray emission point setting function unit 522, and executes electromagnetic field calculation processing. Details of the electromagnetic field calculation processing will be described later with reference to FIG. 2B. The calculation control device 520 acquires the electric field strength distribution within the wireless communication service area as the processing result of the electromagnetic field calculation engine 510.

[0030] Next, in step S20, the calculation control device 520 uses the electromagnetic field calculation engine 510 to draw a structure on the display screen of the display device 560. Next, in step S21, the calculation control device 520 uses the electromagnetic field calculation engine 510 to draw a moving object on the display screen of the display device 560. Next, in step S22, the calculation control device 520 uses the electromagnetic field calculation engine 510 to draw an electric field intensity distribution on the display screen of the display device 560.

[0031] (Electromagnetic Field Calculation Processing According to First Embodiment) FIG. 1C is a flowchart showing the electromagnetic field calculation processing (step S19 (FIG. 1B)) in the main operation processing of the radio wave environment model calculation system 1S according to the first embodiment.

[0032] First, in step S19a, the electromagnetic field calculation engine 510 calculates the limit path length L of the ray. ｍａｘ Next, in step S19b, the electromagnetic field calculation engine 510 emits a ray from the ray emission point 552. Next, in step S19c, the electromagnetic field calculation engine 510 propagates the ray in free space.

[0033] Next, in step S19d, the electromagnetic field calculation engine 510 determines whether the propagation ray propagated in step S19c passes through the receiving surface polygon. If the propagation ray passes through (step S19d YES), the electromagnetic field calculation engine 510 proceeds to step S19e, and if the propagation ray does not pass through (step S19d NO), the electromagnetic field calculation engine 510 proceeds to step S19f.

[0034] In step S19e, the electromagnetic field calculation engine 510 stores and accumulates the ray data in the receiving surface polygon.

[0035] In step S19f following step S19d or step S19e, the electromagnetic field calculation engine 510 searches for a congruent polygon (collision polygon) that collides with the ray at the position closest to the ray emission point 552.

[0036] Next, in step S19g, the electromagnetic field calculation engine 510 calculates the total value of the path length of the ray at the time of collision (total path length) and the limit path length L ｍａｘThe electromagnetic field calculation engine 510 ends the process if the total path length of the ray is equal to or greater than the limit path length (NO in step S19g), and proceeds to step S19h if the total path length of the ray is less than the limit path length (YES in step S19g).

[0037] In step S19h, the electromagnetic field calculation engine 510 re-emits the reflected ray from the collision point, and returns the process to step S19c.

[0038] (Effects of Embodiment 1) According to this embodiment, the electric field strength distribution and propagation rays within a wireless communication service area can be displayed in terms of their relative positional relationship with stationary structures and moving objects present within the wireless communication service area, which is effective in improving the reliability of estimation and diagnosis of wireless communication characteristics within the wireless communication service area.

[0039] [Modification of First Embodiment] (Radio wave environment model calculation system 1S1 according to a modification of First Embodiment) Fig. 2 is a diagram showing the configuration of a radio wave environment model calculation system 1S1 according to a modification of First Embodiment. The radio wave environment model calculation system 1S1 according to the modification of First Embodiment differs from the radio wave environment model calculation system 1S according to First Embodiment in that the storage device 540 further stores mobile body electrical data 543. The mobile body shape data 541 is converted into mobile body polygon data 532 by the calculation model generation device 530 using the mobile body electrical data 543.

[0040] (Effects of the modified example of embodiment 1) According to this embodiment, the accuracy of calculation of the electromagnetic field distribution within a wireless communication service area can be improved using mobile body electrical data representing the electrical characteristics of the mobile body, which is effective in improving the reliability of estimation and diagnosis of wireless communication characteristics within a wireless communication service area.

[0041] [Embodiment 2] (Configuration of radio wave environment model calculation system 2S according to embodiment 2) Fig. 3A is a diagram showing the configuration of a radio wave environment model calculation system 2S according to embodiment 2. Compared to the radio wave environment model calculation system 1S according to embodiment 1, the radio wave environment model calculation system 2S according to embodiment 2 has a calculation control device 520 that includes a reflection point data storage function unit 526, and enables the electromagnetic field calculation to be performed at high speed using reflection points.

[0042] (Main Operation Processing of Radio Wave Environment Model Calculation System 2S According to Second Embodiment) FIG. 3B is a flowchart showing main operation processing of the radio wave environment model calculation system 2S according to the second embodiment.

[0043] First, in step S21, the input device 550 inputs a ray emission point 552 to the calculation control device 520.

[0044] Next, in step S22, the calculation model generating device 530 generates polygons by reading the structure shape data 542. Next, in step S23, the calculation model generating device 530 generates structure polygon data 531 based on the polygons generated in step S22.

[0045] Next, in step S24, the calculation control device 520 performs direct wave calculation processing for the structure using the electromagnetic field calculation engine 510. Details of the direct wave calculation processing will be described later with reference to FIG. 3C. Next, in step S25, the reflection point data storage function unit 526 of the calculation control device 520 stores the direct wave ray R for the structure as the calculation result of step S24. Ｓ ｉ The path length L Ｓ Remember.

[0046] Next, in step S26, the computational model generating device 530 generates polygons by reading the moving object shape data 541. Next, in step S27, the computational model generating device 530 generates moving object polygon data 532 based on the polygons generated in step S26.

[0047] Next, in step S28, the calculation control device 520 performs direct wave calculation processing for the moving object using the electromagnetic field calculation engine 510. Details of the direct wave calculation processing will be described later with reference to FIG. 3C. Next, in step S29, the reflection point data holding function unit 526 stores the direct wave ray R for the moving object as the calculation result of step S28. ｄ ｉ The path length L ｄ Remember.

[0048] Next, in step S30, the calculation control device 520 compares the path lengths of the direct wave rays for the structure and the moving object radiated in the same direction from a predetermined ray radiation point 552 in the space of the radio wave environment model. Ｓ ｉ The path length L Ｓ is the direct wave ray R ｄ ｉ The path length L ｄ If the direct wave ray R is larger than the target object (YES in step S30), the process proceeds to step S31. Ｓ ｉ The path length L Ｓ is the direct wave ray R ｄ ｉ The path length L ｄ In the following cases (NO in step S30), the process proceeds to step S32. In step S31, the calculation control device 520 calculates the direct wave ray R Ｓ ｉ In step S32, the calculation control device 520 rejects the direct wave ray R ｄ ｉ is rejected.

[0049] In step S33 following step S31 or S32, the calculation model generating device 530 generates structure polygon data 531 relating to the structure.

[0050] Next, in step S34, the electromagnetic field calculation engine 510 executes a reflected wave calculation process based on the structure polygon data 531 related to the structure generated in step S33. The details of the reflected wave calculation process will be described later with reference to FIG. 3D. Next, in step S35, the reflection point data storage function unit 526 stores the reflected wave ray r related to the structure as the calculation result of step S34. Ｓ ｉ The path length of Ｓ Remember.

[0051] Next, in step S 36 , the computational model generating device 530 generates moving object polygon data 532 .

[0052] Next, in step S37, the electromagnetic field calculation engine 510 executes a reflected wave calculation process based on the moving body polygon data 532 related to the moving body generated in step S36. The details of the reflected wave calculation process will be described later with reference to FIG. 3D. Next, in step S38, the reflection point data holding function unit 526 stores the reflected wave ray r related to the moving body as the calculation result of step S37. ｄ ｉ The path length of ｄ Remember.

[0053] Next, in step S39, the receiving area setting function unit 523 of the calculation control device 520 generates a receiving area polygon from the receiving area 551 input from the input device 550. Next, in step S40, the calculation control device 520 executes drawing of structures and moving objects on the display device 560.

[0054] Next, in step S41, the calculation control device 520 executes field intensity and ray drawing on the display device 560.

[0055] (Direct Wave Calculation Processing According to Second Embodiment) FIG. 3C is a flowchart showing the direct wave calculation processing (steps S24, S28 (FIG. 3B)) in the main operation processing of the radio wave environment model calculation system 2S according to the second embodiment.

[0056] First, in step S24a, the electromagnetic field calculation engine 510 calculates the limit path length L of the ray. ｍａｘ Next, in step S24b, the electromagnetic field calculation engine 510 emits a ray from the ray emission point 552. Next, in step S24c, the electromagnetic field calculation engine 510 propagates the ray emitted in step S24b through free space.

[0057] Next, in step S24d, the electromagnetic field calculation engine 510 determines whether the ray propagated in step S24c passes through the receiving surface polygon. If the ray passes through the receiving surface polygon (step S24d YES), the electromagnetic field calculation engine 510 proceeds to step S24e. If the ray does not pass through (step S24d NO), the electromagnetic field calculation engine 510 proceeds to step S24f. In step S24e, the electromagnetic field calculation engine 510 stores and accumulates the ray data in the receiving surface polygon.

[0058] Next, in step S24f, the electromagnetic field calculation engine 510 performs a closest collision polygon search to search for a polygon that collides with the ray in the closest position. Next, in step S24g, the electromagnetic field calculation engine 510 calculates the total value L of the path length of the ray at the time of collision with the closest collision polygon found in step S24f as the limit path length L ｍａｘ The electromagnetic field calculation engine 510 compares L<L ｍａｘ If L≧L (YES in step S24g), the process proceeds to step S24h. ｍａｘ If so (step S24g NO), the direct wave calculation process ends.

[0059] In step S24h, the reflection point data storage function unit 526 of the calculation control device 520 stores the collision point between the ray and the nearest collision polygon. Next, in step S24i, the reflection point data storage function unit 526 stores the direction of the reflected wave of the ray reflected from the collision point between the ray and the nearest collision polygon. When step S24i is completed, the electromagnetic field calculation engine 510 returns the process to step S25.

[0060] 3D is a flowchart showing the reflected wave calculation process (steps S34, S37 (FIG. 3B)) in the main operation process of the radio wave environment model calculation system 2S according to embodiment 2. The reflected wave calculation process is different from the direct wave calculation process in that step S34b is executed instead of step S24b, and reflected waves are calculated until the total path length of the ray radiated from the collision point exceeds the limit path length, but is otherwise similar.

[0061] In step S34b, the electromagnetic field calculation engine 510 emits a ray from the collision point. The collision point is a point on a polygon where the direct wave stored in step S24h of the direct wave calculation process (FIG. 3C) collides with a structure polygon or a moving object polygon. Alternatively, the collision point is a point on a polygon where the indirect wave stored in step S24h of the indirect wave calculation process (FIG. 3D) previously collided with a structure polygon or a moving object polygon.

[0062] In the indirect wave calculation process, when step S24i is completed, the process returns to step S34b. Also, in the indirect wave calculation process, if the determination in step S24g is YES, the indirect wave calculation process is completed.

[0063] (Effects of Embodiment 2) According to this embodiment, the collision points of direct waves and indirect waves with structure polygons or moving body polygons and the reflection directions after the collision are stored, and reflected waves are propagated based on the stored information. Therefore, the electromagnetic field distribution in a wireless communication service area, including direct waves and reflected waves of rays, can be calculated at high speed. Furthermore, it is possible to simultaneously and quickly draw the positions and shapes of structures and moving bodies present in the wireless communication service area, and display the electric field strength distribution and propagation rays in the wireless communication service area. This has the effect of enabling real-time estimation and evaluation of the wireless communication quality of a wireless system including moving bodies.

[0064] Third Embodiment (Configuration of a Radio Wave Environment Model Calculation System 3S According to a Third Embodiment) A radio wave environment model calculation system 3S according to a third embodiment is similar to the radio wave environment model calculation system 2S (FIG. 3A) according to the second embodiment.

[0065] (Main Operation Processing of Radio Wave Environment Model Calculation System 3S According to Embodiment 3) Fig. 4A is a flowchart showing the main operation processing of the radio wave environment model calculation system 3S according to embodiment 3. Fig. 4B is a flowchart showing the moving object point cloud measurement / data generation processing (step S26B (Fig. 4A)) in the main operation processing of the radio wave environment model calculation system 3S according to embodiment 3. The main operation processing of the radio wave environment model calculation system 3S according to embodiment 3 is the same as that of the radio wave environment model calculation system 2S according to embodiment 2, except that step S26B is executed instead of step S26.

[0066] In the moving object point cloud measurement / data generation process shown in FIG. 4B, first, in step S26Ba, the calculation model generation device 530 acquires point cloud data {P ｏｌｄ ｎNext, in step S26Bb, the calculation model generation device 530 acquires the point cloud data {P ｏｌｄ ｎ Next, in step S26Bc, the calculation model generation device 530 stores the point cloud data {P ｎｅｗ ｎ} is reacquired.

[0067] Next, in step S26Bd, the calculation model generating device 530 calculates the point cloud data {P ｏｌｄ ｎ} and point cloud data {P ｎｅｗ ｎ The computational model generating device 530 compares {P ｏｌｄ ｎ}≡{P ｎｅｗ ｎ} (step S26BdYES), the moving object point cloud measurement / data generation process is terminated, and {P ｏｌｄ ｎ}≠{P ｎｅｗ ｎ} (NO in step S26Bd), the process proceeds to step S16Be.

[0068] In step S26Be, the calculation model generating device 530 calculates the point cloud data {P ｏｌｄ ｎ} and point cloud data {P ｏｌｄ ｎ} difference set {P ｄ ｎ}={P ｎｅｗ ｎ}-{P ｏｌｄ ｎ Next, in step S26Bf, the computational model generation device 530 calculates the difference set {P ｄ ｎ} into a plurality of polygons. Next, in step S26Bg, the computational model generation device 530 generates moving object polygon data 532 from the plurality of polygons generated in step S26Bf.

[0069] According to the present embodiment, the position and shape of a mobile object existing within a wireless communication service area can be updated at any time using the actual measured values ​​of point cloud data obtained by a point cloud measurement device, thereby enabling real-time estimation and evaluation of the wireless communication quality of a wireless system that follows the movement of the mobile object.

[0070] [Fourth Embodiment] (Configuration of a radio wave environment model calculation system 4S according to a fourth embodiment) Fig. 5A is a diagram showing the configuration of a radio wave environment model calculation system 4S according to a fourth embodiment. The radio wave environment model calculation system 4S according to the fourth embodiment differs from the radio wave environment model calculation system 3S according to the third embodiment in that it further includes an image analysis device 570 and an image capturing device 603.

[0071] The image analysis device 570 has an image diagnosis function unit 571 and an image database that stores moving body image data 572. In the image database, physical property information such as the size of each moving body and electrical properties related to wireless communication radio waves is associated with and managed for the moving body image data 572 of each moving body.

[0072] In the radio wave environment model calculation system 4S, image data acquired by the image capturing device 603 is input to the image analysis device 570. The image diagnosis function unit 571 of the image analysis device 570 compares the input image data with moving object image data 572 and identifies the size and electrical characteristics of the moving object identified by the image data. The calculation model generation device 530 then generates moving object polygon data 532 based on the size and electrical characteristics of the moving object.

[0073] (Main Operation Processing of Radio Wave Environment Model Calculation System 4S According to Embodiment 4) Fig. 5B is a flowchart showing the main operation processing of the radio wave environment model calculation system 4S according to embodiment 4. Fig. 5C is a flowchart showing the moving object point cloud measurement / data generation processing (step S26C (Fig. 5B)) in the main operation processing of the radio wave environment model calculation system 4S according to embodiment 4. The main operation processing of the radio wave environment model calculation system 4S according to embodiment 4 is the same as that of the radio wave environment model calculation system 3S according to embodiment 2, except that step S26C is executed instead of step S26.

[0074] In the moving object point cloud measurement / data generation process shown in FIG. 5C, first, in step S26Ca, the computational model generation device 530 reads the moving object image database (moving object image data 572 of the image analysis device 570). Next, in step S26Cbd, the computational model generation device 530 reads the point cloud data {P ｏｌｄ ｎ Next, in step S26Cc, the calculation model generation device 530 acquires the image data {p ｏｌｄ ｎ Next, in step S26Cd, the calculation model generation device 530 acquires the point cloud data {P ｏｌｄ ｎ Next, in step S26Ce, the calculation model generating device 530 stores the image data {p ｏｌｄ ｎ} is stored.

[0075] Next, in step S26Cf, the calculation model generating device 530 calculates the point cloud data {P ｎｅｗ ｎ Next, in step S26Cg, the computational model generating device 530 reacquires the image data {p ｎｅｗ ｎ} is reacquired.

[0076] Next, in step S26Ch, the calculation model generating device 530 calculates the point cloud data {P ｏｌｄ ｎ} and point cloud data {P ｎｅｗ ｎ The computational model generating device 530 compares {P ｏｌｄ ｎ}≡{P ｎｅｗ ｎ} (step S26ChYES), the moving object point cloud measurement / data generation process is terminated, and {P ｏｌｄ ｎ}≠{P ｎｅｗ ｎ} (step S26ChNO), the process proceeds to step S26Ci.

[0077] In step S26Ci, the computational model generating device 530 calculates the image data [{P ０ ｎ}, {P １ ｎ}, ...] in which point cloud data {P ｏｌｄ ｎ} and point cloud data {P ｏｌｄ ｎ} difference set {P ｎｅｗ ｎ}-{P ｏｌｄ ｎ}. In other words, [{P ０ ｎ}, {P １ ｎ}, ...] ∋{P ｄ ｎ If there is a match (step S26Ci: YES), the calculation model generation device 530 proceeds to step S16Cj, and if there is no match (step S26Ci: NO), the calculation model generation device 530 ends the moving object point cloud measurement / data generation process.

[0078] Next, in step S26Cj, the calculation model generating device 530 calculates the image data [{P ０ ｎ}, {P １ ｎ}, ...] {P ｎｅｗ ｎ}-{P ｏｌｄ ｎ} into the difference set {P ｄ ｎ Next, in step S26Ck, the computational model generation device 530 calculates the difference set {P ｄ ｎ} into a plurality of polygons. Next, in step S26Cl, the computational model generation device 530 generates moving object polygon data 532 from the plurality of polygons generated in step S26Ck.

[0079] (Effects of embodiment 4) According to this embodiment, the calculation accuracy of the electromagnetic field distribution within a wireless communication service area can be improved using the precise size and electrical characteristics of the mobile object, which is effective in improving the reliability of estimation and diagnosis of wireless communication characteristics when a mobile object is included within the wireless communication service area.

[0080] Below, examples of the above-mentioned first to fourth embodiments will be described. Mobile bodies have an overwhelmingly smaller number of polygons than stationary structures. In the following examples, the electromagnetic wave equivalence theorem is used to separate the polygon generation process for stationary structures and mobile bodies. Then, the calculation results of the radio wave environment for stationary structures are kept fixed, and the radio wave environment for only the mobile bodies is repeatedly recalculated, and the two are superimposed to obtain real-time calculation results of the radio wave environment that track the movement of the mobile body.

[0081] (Operation of the Radio Wave Environment Model Calculation System According to the First Embodiment) FIGS. 6A to 6C are diagrams for explaining the operation of the radio wave environment model calculation system according to the first embodiment.

[0082] 6A , a base station 1, a terminal station 2, a stationary structure 3, and a mobile object 4 located on a road 5 are located within a wireless communication service area 101. The base station 1, the terminal station 2, and the mobile object 4 are each equipped with a base station antenna 11, a terminal station antenna 12, and a mobile object antenna 14. The base station 1 communicates with a plurality of terminal stations 2 using radio waves 71, and also communicates with a plurality of mobile objects 4 using radio waves 71.

[0083] 6B shows the operation in cyberspace among the computer resources of the radio wave environment model calculation system. As shown in FIG. 6B, the surface of a stationary structure 3 is represented by a point cloud 31 and a polygon 32 having a plurality of point clouds as vertices. The surface of a moving object 4 is represented by a point cloud 41 and a polygon 42 having a plurality of point clouds as vertices. The base station 1 communicates with a plurality of terminal stations 2 and the moving object 4 by direct waves or reflected waves using a plurality of rays 74 radiated into three-dimensional space from a ray radiation point 73 on the base station antenna 11.

[0084] 6C is a diagram showing the process of assigning IDs to polygons representing a stationary structure 3 and a moving body 4 in cyberspace within the computer resources of the radio wave environment model calculation system. Fig. 6C is a plan view of the cyberspace. In Fig. 6C, polygons 32 and 42 representing the stationary structure 3 and the moving body 4, respectively, are represented by a plurality of triangles that form the outer shapes of quadrangles.

[0085] In diagram F11 at the top of Fig. 6C, IDs are assigned to the multiple polygons representing the stationary structure 3 in the order of the IDs so that the distance between each polygon is minimized. Diagram F12 in the middle of Fig. 6C shows a state in which, in addition to Fig. F11, IDs have been newly assigned to the multiple polygons representing the moving body 4. In Fig. F12, the condition that the distance between each polygon is minimized in the order of the IDs is not satisfied for the entire system including the stationary structure 3 and the moving body 4. Therefore, as shown in diagram F13 at the bottom of Fig. 6C, the IDs are changed for most of the polygons relating to the stationary structure 3 and the moving body 4.

[0086] As shown in Figure 6B, in cyberspace within computer resources, radio waves are treated as rays traveling in a straight line through space, and the electromagnetic field is calculated. When a ray collides with a polygon, it is re-emitted from the collision point and travels in a straight line through space, repeating this process. Therefore, in electromagnetic field calculations that approximate radio waves with rays, a lot of time is spent calculating which polygon the ray will collide with.

[0087] Effect of First Embodiment According to this embodiment, when a ray makes a collision detection with the total number of polygons that represent, within computer resources, stationary structures and moving bodies that scatter electromagnetic waves and are present within a wireless communication area, the collision detection is performed in the order of the IDs assigned to each polygon, thereby making it possible to significantly reduce the calculations for collision detection. This is because, of the stationary structures and moving bodies that are placed within a wireless communication service area, only those that are located closest in the traveling direction of the ray will actually cause a collision.

[0088] Furthermore, according to this embodiment, it is possible to significantly reduce the calculation time when calculating the electromagnetic field within a wireless communication service area by approximating radio waves as rays in cyberspace within computer resources. Therefore, it is possible to calculate the electromagnetic field distribution within the area by following the movement of a mobile object present within the wireless communication service area, which has the effect of realizing a prompt estimation of wireless communication quality.

[0089] (Operation of the Radio Wave Environment Model Calculation System According to the Second Embodiment) FIGS. 7A to 7E are diagrams for explaining the operation of the radio wave environment model calculation system according to the second embodiment.

[0090] As shown in Fig. 7A, a base station 1, a terminal station 2, and a stationary structure 3 are located within a wireless communication service area 102. The base station 1 and the terminal station 2 are equipped with a base station antenna 11 and a terminal station antenna 12, respectively. As shown in Fig. 7A, the surface of the stationary structure 3 is represented by a point cloud 31 and a polygon 32 having a plurality of point clouds as vertices. The base station 1 communicates with a plurality of terminal stations 2 using radio waves by direct waves or reflected waves. In Fig. 7A, the path of the radio waves is represented by a ray 74.

[0091] In Fig. 7B, a base station 1, a terminal station 2, and a mobile object 4 located on a road 5 are located within a wireless communication service area 102. The base station 1, the terminal station 2, and the mobile object 4 are equipped with a base station antenna 11, a terminal station antenna 12, and a mobile object antenna 14, respectively. As shown in Fig. 7B, the surface of the stationary structure 3 is represented by a point cloud 31 and a polygon 32 having a plurality of point clouds as vertices. The surface of the mobile object 4 is represented by a point cloud 41 and a polygon 42 having a plurality of point clouds as vertices.

[0092] The base station 1 communicates with multiple terminal stations 2 using direct waves or reflected waves, using multiple rays 74 (rays #a, #i, #k, ... in Figure 7B) emitted into three-dimensional space from a ray emission point 73 on the base station antenna 11.

[0093] In Fig. 7B, multiple rays #a, #j, and #k reach the terminal station antenna 12 or the terminal station antenna 12 via direct waves. In Fig. 7B, the stationary structure 3 is represented by a dashed polygon 32 and is assumed not to exist, so if the stationary structure 3 exists, rays that do not reach the mobile antenna 14 via direct waves also reach the mobile antenna 14.

[0094] Figure 7C shows the progress of a ray in cyberspace when only stationary structures 3 are present within the wireless communication service area. For clarity of explanation, Figure 7C shows only polygons related to one stationary structure 3. As is clear from Figure 7C, ray #j, which in Figure 7B reached the mobile antenna 14 as a direct wave, is blocked by the stationary structure 3 and does not reach the mobile antenna 14, becoming a reflected wave. The arrival of a ray can be easily determined by comparing rays emitted from the same ray emission point 73 in Figures 7A and 7B.

[0095] 7D shows how a ray 74 emitted from the ray emission point 73 obtained in FIG. 7A is reflected by the stationary structure 3 and reaches the terminal station 2 and the mobile antenna 14. Collision determination between the polygon 42 constituting the mobile antenna 14 and the ray (reflected wave) is performed using only the ray 74 reflected by the stationary structure 3 among the rays 74 shown in FIG. 7A.

[0096] 7E shows IDs assigned to polygons 32, 42 that represent the stationary structure 3 and the moving body 4 in cyberspace in this embodiment. In this embodiment, a group of polygons related to the stationary structure 3 and a group of polygons related to the moving body 4 are used separately. That is, a first electric field intensity distribution based on the structure polygon (polygon 32) is obtained from the electromagnetic field calculation engine 510, and a second electric field intensity distribution based on the moving body polygon (polygon 42) is obtained separately from the electromagnetic field calculation engine 510. Then, the first electric field intensity distribution and the second electric field intensity distribution are superimposed to generate an electric field intensity distribution 561.

[0097] As is clear from FIG. 7E, unlike Example 1, it is not necessary to change the IDs assigned to polygons in cyberspace, and the amount of calculation required for electromagnetic field calculations due to the ray's straight-line travel, collision, and re-radiation process can be significantly reduced.

[0098] According to the present embodiment, it is possible to significantly reduce the calculation time required for calculating the electromagnetic field within a wireless communication service area by approximating radio waves as rays in cyberspace within computer resources. Therefore, it is possible to quickly calculate the electromagnetic field distribution within a wireless communication service area where a mobile object exists, and it is possible to achieve an effect of realizing estimation of wireless communication quality in real time.

[0099] In this embodiment, the radio wave environment is calculated using only direct waves that directly reach the mobile object, and therefore, this embodiment is suitable for measuring the radio wave environment for controlling the mobile object.

[0100] (Operation of the Radio Wave Environment Model Calculation System According to the Third Embodiment) FIGS. 8A to 8F are diagrams for explaining the operation of the radio wave environment model calculation system according to the third embodiment.

[0101] As shown in Fig. 8A, a base station 1, a terminal station 2, and a stationary structure 3 are located within a wireless communication service area 103. The base station 1 and the terminal station 2 are equipped with a base station antenna 11 and a terminal station antenna 12, respectively. As shown in Fig. 8A, the surface of the stationary structure 3 is represented by a point cloud 31 and a polygon 32 having a plurality of point clouds as vertices.

[0102] 8A , a base station 1 communicates with multiple terminal stations 2 using radio waves by direct waves or reflected waves. The base station 1 emits multiple rays 74 from a ray emission point 73 in all directions in three-dimensional space at predetermined fixed intervals. In FIG. 8A , some of the multiple rays 74 reach the terminal station antenna 12.

[0103] 8B , the base station 1 also radiates multiple rays 74 into all three-dimensional space at predetermined fixed intervals from a ray radiation point 73 on the base station antenna 11. In Fig. 8B , some of the multiple rays 74 are blocked by the stationary structure 3 and do not reach the terminal station antenna 12, and some of the remaining rays 74 reach the terminal station antenna 12 and the mobile antenna 14.

[0104] By comparing rays 74 with the same radiation direction in Figures 8A and 8B and selecting the ray 74 with the shorter path length, the wireless communication path in cyberspace including the base station 1, terminal station 2, and mobile antenna 14 using direct waves in Figure 8C is calculated using the ray of direct waves.

[0105] Fig. 8D shows an example of identifying a ray 74 that collides with a stationary structure 3 among multiple rays emitted from a ray emission point 73 in cyberspace, as calculated by Fig. 8A, and storing a collision point 81 on a polygon 32 related to the stationary structure 3 and a re-emission direction 82 of the reflected ray. As shown in Fig. 8E, using the collision point 81 and the re-emission direction 82, an electromagnetic field calculation is performed by a ray in cyberspace, assuming that the stationary structure 3 does not exist, as in Fig. 8B.

[0106] Then, the electromagnetic field calculation result including the ray obtained in Fig. 8C is superimposed on the electromagnetic field calculation result including the ray obtained in Fig. 8E. By combining the vectors of the ray in Fig. 8C and the reflected ray in Fig. 8E at the collision point 81, it is possible to estimate the wireless communication characteristics between the base station 1 and the multiple terminal stations 2 and multiple mobile objects 4.

[0107] 8F shows polygon groups used in calculating, by rays, the wireless communication characteristics between the base station 1 and multiple terminal stations 2 and multiple moving bodies 4 in this embodiment. As is clear from comparison with FIG. 7E of Example 2, in one calculation, either the polygon group related to the stationary structure 3 or the polygon group related to the moving body 4 is used independently, which enables faster calculations compared to Example 2.

[0108] According to the present embodiment, it is possible to simplify the calculation algorithm when calculating the electromagnetic field in a wireless communication service area by approximating radio waves as rays in cyberspace within computer resources. This enables high-speed calculation of the electromagnetic field distribution in a wireless communication service area where a mobile object exists, thereby realizing estimation of wireless communication quality in real time.

[0109] In this embodiment, the radio wave environment of reflected waves that are reflected by stationary structures and reach mobile bodies is calculated by comparing an environment containing only stationary structures with an environment containing both stationary structures and mobile bodies, making it suitable for measuring a radio wave environment suitable for distributing data to mobile bodies.

[0110] (Operation of the Radio Wave Environment Model Calculation System According to the Fourth Embodiment) FIGS. 9A to 9C are diagrams for explaining the operation of the radio wave environment model calculation system according to the fourth embodiment.

[0111] 9A , a base station 1, a terminal station 2, a stationary structure 3, and a mobile object 4 located on a road 5 are located within a wireless communication service area 104. The base station 1, the terminal station 2, and the mobile object 4 are each equipped with a base station antenna 11, a terminal station antenna 12, and a mobile object antenna 14. The base station 1 communicates with the plurality of terminal stations 2 and the plurality of mobile objects 4 using a direct wave 76 radiated from a ray radiation point 73 on the base station antenna 11 and a reflected wave 78 formed by the direct wave 76 being reflected by the surface of a polygon 32.

[0112] 9A, the surface of the stationary structure 3 is represented by a point cloud 31 and a polygon 32 having a plurality of point clouds as vertices. The surface of the moving object 4 is represented by a point cloud 41 and a polygon 42 having a plurality of point clouds as vertices.

[0113] As shown in Fig. 9B , in this embodiment, the electromagnetic field distribution is calculated within a limited area 6 set by a user on a road 5. In the case of measuring a communication environment for automatic driving of a vehicle, the limited area 6 may be a location where accidents frequently occur. When the limited area 6 is set, as shown in Fig. 9C , electromagnetic field calculations using rays are performed within a limited area 6A where no moving object 4 is present. In other words, the necessary calculations are performed only for rays that are emitted from a ray emission point 73 and reach the limited area 6A.

[0114] (Effects of Fourth Embodiment) According to this embodiment, it is possible to omit in advance the calculation of rays that do not contribute to the electromagnetic field distribution in the limited area 6, which is effective in shortening the electromagnetic field calculation time of the radio wave environment model calculation system.

[0115] (Operation of the Radio Wave Environment Model Calculation System According to the Fifth Embodiment) FIGS. 10A to 10D are diagrams for explaining the operation of the radio wave environment model calculation system according to the fifth embodiment.

[0116] 10A , a base station 1, a terminal station 2, a stationary structure 3, and a mobile object 4 located on a road 5 are located within a wireless communication service area 105. The base station 1, the terminal station 2, and the mobile object 4 are each equipped with a base station antenna 11, a terminal station antenna 12, and a mobile object antenna 14. The base station 1 communicates with the multiple terminal stations 2 and the multiple mobile objects 4 using a direct wave 76 and a reflected wave 78 radiated from a ray radiation point 73.

[0117] This embodiment differs from Example 1 in that multiple moving bodies 4 are close to each other, and one moving body 4 may block radio waves to the other moving bodies 4. In this embodiment, as shown in Figures 10B and 10C, the electromagnetic field distribution in a state in which it is assumed that a specific one of the multiple moving bodies 4 is present and the other moving bodies 4 are not present is calculated using the method of Example 3. Then, the electromagnetic field calculation results for each state are compared, and the ray with the shortest path length is selected from the rays radiated from the ray emission point 73. The selected rays are superimposed to obtain the desired electromagnetic field distribution.

[0118] As shown in Figure 10D, the procedure for performing electromagnetic field calculations using rays is shown, using a polygon group Pg0 that represents a stationary structure 3 in cyberspace within the computer resources, and polygon groups Pg1 and Pg2 that represent, for example, two moving bodies 4, respectively, in cyberspace within the computer resources.

[0119] First, a selected area is defined as a specific micro-area for which electromagnetic field calculations are to be performed. First, polygon group Pg0 is used to perform electromagnetic field calculations using multiple rays emitted from ray emission point 73 in multiple predetermined directions, and rays that reach the selected area within the wireless communication service area are extracted. Next, a similar calculation is performed using polygon group Pg1 to extract rays that reach the selected area. Subsequently, a similar calculation is performed on polygon group Pg2 to extract rays that reach the selected area. If there are three or more moving bodies 4, the same calculation is repeated for each moving body 4.

[0120] Compare the calculation results of the rays arriving at the selection areas related to the polygon group Pg0 and the polygon groups Pg1 and Pg2. When there are rays arriving at the same minute area within the selection area, leave the ray with the shortest travel path length among them and delete the other rays. By the above procedure, identify the rays arriving within the selection area and determine the calculation results of the electromagnetic field within the selection area. Note that the size of the minute area set within the selection area is preferably 1 / 2 or less of the wavelength of the electromagnetic wave used in the communication.

[0121] (Effect of Example 5) According to this example, since no modification of the calculation model occurs in the electromagnetic field calculation in each step of FIG. 10D, the electromagnetic field calculation can be performed at high speed. Since it is possible to calculate the influence of other mobile bodies on the communication characteristics of the mobile body communicating with the base station, it is effective in improving the accuracy of the calculation results of the electromagnetic field calculation when mobile bodies are densely distributed within the wireless communication service area.

[0122] (Operation of the Radio Wave Environment Model Calculation System According to Example 6) FIGS. 11A to 11B are diagrams for explaining the operation of the radio wave environment model calculation system according to Example 6.

[0123] As shown in FIG. 11A, within the wireless communication service area 106, a base station 1, a terminal station 2, a stationary structure 3, and a road 5 are arranged. The base station 1 and the terminal station 2 each include a base station antenna 11 and a terminal station antenna 12. The base station 1 communicates with a plurality of terminal stations 2. [[ID=eleven]]

[0124] Within the wireless communication service area 106, a mobile point group acquisition device 8 equipped with LiDAR (Light Detection And Ranging) 18 operates while moving along a path 28. The path 28 is set so as to overlook all the sides of the stationary structure 3. The mobile point group acquisition device 8 acquires a point group indicating the position of the surface of the stationary structure 3 by laser measurement.

[0125] As shown in FIG. 11B, the surface of the stationary structure 3 is represented by a polygon 32 having a plurality of point groups of the point group 31 as vertices. By the methods of Examples 1 to 5, it becomes possible to calculate the electromagnetic field within the wireless communication service area using the polygon 32.

[0126] (Effects of Example 6) According to this example, physical data including the shape and position of stationary structures within a wireless communication service area can be obtained by actual measurements using measuring equipment such as LiDAR, which is effective in improving the accuracy of electromagnetic field calculations within the wireless communication service area.

[0127] (Operation of the Radio Wave Environment Model Calculation System According to the Seventh Embodiment) FIGS. 12A and 12B are diagrams for explaining the operation of the radio wave environment model calculation system according to the seventh embodiment.

[0128] 12A , a base station 1, a terminal station 2, a stationary structure 3, a fixed point cloud acquisition device 7, and a mobile object 4 moving on a road 5 are located within a wireless communication service area 107. The base station 1, the terminal station 2, and the mobile object 4 are equipped with a base station antenna 11, a terminal station antenna 12, and a mobile object antenna 14, respectively.

[0129] A base station 1 communicates with a plurality of terminal stations 2 and a plurality of mobile objects 4. A fixed point cloud acquisition device 7 is installed along a road 5. The fixed point cloud acquisition device 7 includes a LiDAR 17. The fixed point cloud acquisition device 7 acquires a point cloud 41 related to a mobile object 4 moving within the road 5.

[0130] As shown in Fig. 12B, the point cloud data acquired by the fixed point cloud acquisition device 7 is converted into a polygon 42 relating to the moving body 4 within the computer resources. Each time a point cloud 41 is acquired, a polygon 42 (moving body polygon) is regenerated from the point cloud 41. As shown in Fig. 12C, the surface of the stationary structure 3 is represented by a polygon 32 having multiple points in the point cloud 31 as vertices. Using the polygons 32 and 42, it is possible to calculate the electromagnetic field within the wireless communication service area by the methods of Examples 1 to 5.

[0131] Effect of Seventh Embodiment According to this embodiment, physical data including the shape and position of a moving object within a wireless communication service area can be obtained by actual measurement, which is effective in improving the accuracy of electromagnetic field calculation within the wireless communication service area.

[0132] (Operation of the Radio Wave Environment Model Calculation System According to the Eighth Example) FIG. 13 is a diagram for explaining the operation of the radio wave environment model calculation system according to the eighth example.

[0133] 13 , the position, shape, and moving speed of a moving object 4 traveling on a road 5 are measured from point cloud data acquired by a fixed point cloud acquisition device 7 installed along a road 5 within a wireless communication service area 108. The fixed point cloud acquisition device 7 includes a LiDAR 17. The moving object 4, whose presence is detected by the LiDAR 17 of the fixed point cloud acquisition device 7, can estimate its position after a predetermined time T has elapsed. The eighth embodiment differs from the seventh embodiment in that the estimated position is used to determine the electromagnetic field distribution within the wireless communication service area 108 after the predetermined time T has elapsed by electromagnetic field calculation using rays.

[0134] 13 , the surface of the stationary structure 3 is represented by a polygon 32 having vertices that are a plurality of points in the point cloud 31, and the surface of the moving body 4 after a predetermined time T has elapsed is estimated by a polygon 42 having vertices that are a plurality of points in the point cloud 41 acquired by the LiDAR 17. Using the polygon 32 and the polygon 42, it is possible to calculate the electromagnetic field within the wireless communication service area by the methods of Examples 1 to 5.

[0135] Effect of Example 8 According to this example, it is possible to estimate the electromagnetic field distribution in a wireless communication service area including a mobile object in real time using estimated values ​​of the shape and position of the mobile object in the wireless communication service area, which is effective in improving the accuracy of the communication reliability evaluation of a wireless communication environment using the calculated values ​​of the electromagnetic field distribution in the wireless communication service area.

[0136] (Operation of the Radio Wave Environment Model Calculation System According to the Ninth Embodiment) FIG. 14 is a diagram for explaining the operation of the radio wave environment model calculation system according to the ninth embodiment.

[0137] In this embodiment, a point cloud 41 related to the moving object 4 and images of the moving object 4 are acquired by a camera-equipped LiDAR 19 mounted on a fixed point cloud / image acquisition device 9 installed along a road 5 within a wireless communication service area 109. The point cloud 41 acquired by the camera-equipped LiDAR 19 is used to measure the position, shape, and movement speed of the moving object 4 moving on the road 5. In addition, the images acquired by the camera-equipped LiDAR 19 are used to identify the type of vehicle, etc. of the moving object 4 using image recognition technology, and to determine precise dimensional data and electrical characteristics.

[0138] 14, the surface of the stationary structure 3 is represented by a polygon 32 whose vertices are the plurality of points in the point cloud 31, and the surface of the moving body 4 is represented by a polygon 42 whose vertices are the plurality of points in the point cloud 41. Then, using the specified dimensional data and electrical characteristics of the moving body 4, and the polygon 32 relating to the stationary structure 3 and the polygon 42 relating to the moving body 4, it becomes possible to calculate the electromagnetic field within the wireless communication service area by the methods of Examples 1 to 5.

[0139] According to the present embodiment, it is possible to accurately estimate the electromagnetic field distribution within a wireless communication service area including the mobile object by using precise estimates of the shape and position of the mobile object within the wireless communication service area and the electrical characteristics of the mobile object. This is effective in improving the accuracy of the communication quality evaluation of the wireless communication environment using the calculated values ​​of the electromagnetic field distribution within the wireless communication service area.

[0140] 15 is a diagram showing an example of the hardware configuration of the computer 1000. The computer 1000 executes a predetermined program to realize the radio wave environment model calculation systems according to the above-described first to fourth embodiments and first to ninth examples, and the various devices included in the radio wave environment model calculation systems.

[0141] The computer 1000 comprises a processor 1001 including a CPU, a main memory device 1002, an auxiliary memory device 1003, a network interface 1004, an input device 1005, and an output device 1006, all of which are interconnected via an internal communication line 1007 such as a bus.

[0142] The processor 1001 controls the overall operation of the computer 1000. The main memory device 1002 is composed of, for example, a volatile semiconductor memory, and is used as a work memory for the processor 1001. The auxiliary memory device 1003 is composed of a large-capacity nonvolatile memory device such as a hard disk device, an SSD (Solid State Drive), or a flash memory, and is used to store various programs and data for a long period of time.

[0143] An executable program 1003a stored in the auxiliary storage device 1003 is loaded into the main storage device 1002 when the computer 1000 is started up or when necessary, and is executed by the processor 1001. This realizes the radio wave environment model calculation systems according to the above-described first to fourth embodiments and first to ninth examples, and the various devices included in the radio wave environment model calculation systems.

[0144] The executable program 1003a may be recorded on a non-transitory recording medium, read from the non-transitory recording medium by a medium reading device, and loaded into the main memory device 1002. Alternatively, the executable program 1003a may be obtained from an external computer via a network and loaded into the main memory device 1002.

[0145] The network interface 1004 is an interface device for connecting the computer 1000 to each network within the system or for communicating with other computers. The network interface 1004 is configured, for example, by a network interface card (NIC) for a wired local area network (LAN) or a wireless LAN.

[0146] The input device 1005 is composed of a keyboard, a pointing device such as a mouse, and the like, and is used by the user to input various instructions and information to the computer 1000. The output device 1006 is composed of, for example, a display device such as a liquid crystal display, and an audio output device such as a speaker, and is used to present necessary information to the user when necessary.

[0147] Although the embodiments of the present disclosure have been described in detail above, the present disclosure is not limited to the above-described embodiments and can be modified in various ways without departing from the spirit of the present disclosure. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present disclosure is not necessarily limited to those including all of the described configurations. Furthermore, some of the configurations of the above-described embodiments can be added to, deleted from, or replaced with other configurations.

[0148] Furthermore, the above-described configurations, functional units, processing units, etc. may be partially or entirely implemented in hardware, for example, by designing them as integrated circuits. The above-described configurations, functions, etc. may also be implemented in software by a processor interpreting and executing a program that implements each function. Information such as the programs, tables, and files that implement each function can be stored in a memory, a storage device such as an HDD or SSD, or a recording medium such as an IC card, an SD card, or a DVD.

[0149] In addition, in the above-mentioned drawings, the control lines and information lines shown are those that are considered necessary for explanation, and do not necessarily show all the control lines and information lines that are actually implemented. For example, it may be considered that almost all components are actually connected to each other.

[0150] Furthermore, the above-described radio wave environment model calculation system and the arrangement of the functions and data of the various devices that make up the radio wave environment model calculation system are merely examples. The arrangement, integration, and distribution of the functions and data can be changed to an optimal form in terms of hardware and software performance, processing efficiency, communication efficiency, etc.

[0151] 1S, 1S1, 2S, 3S, 4S: radio wave environment model calculation system, 3: stationary structure, 4: moving body, 6, 6A: limited area, 7: fixed point cloud acquisition device, 8: moving point cloud acquisition device, 9: image acquisition device, 31: point cloud, 32: polygon, 41: point cloud, 42: polygon, 71: radio wave, 73: ray emission point, 74: ray, 76: direct wave, 78: reflected wave, 81: collision point, 510: electromagnetic field calculation engine, 520: calculation control device, 521: polygon rearrangement function unit, 522: ray emission point setting function unit, 523: receiving area setting function unit, 526: reflection point data storage function unit, 530: calculation model generation device, 5 31: Structure polygon data, 532: Moving body polygon data, 540: Storage device, 541: Moving body shape data, 542: Structure shape data, 543: Moving body electrical data, 544: Structure electrical data, 550: Input device, 551: Receiving area, 552: Ray emission point, 560: Display device, 561: Electric field strength distribution, 562: Propagation ray, 563: Moving body, 564: Structure, 570: Image analysis device, 571: Image diagnosis function unit, 572: Moving body image data, 601: Point cloud acquisition device, 602: Moving body detection device, 603: Image capturing device, 1000: Computer, 1001: Processor.

Claims

1. A radio wave environment model calculation system that calculates an electric field intensity distribution in a wireless communication service area where stationary structures and mobile objects are present, the radio wave environment model calculation system having a processor and a memory, wherein the processor: generates a structure polygon representing the stationary structure from point cloud data related to the stationary structure and electrical data representing the electrical characteristics of the stationary structure, generates a mobile body polygon representing the mobile body from the point cloud data related to the mobile body, obtains a first electric field intensity distribution based on the structure polygon from an electromagnetic field calculation engine, obtains a second electric field intensity distribution based on the mobile body polygon from the electromagnetic field calculation engine, generates the electric field intensity distribution based on the first electric field intensity distribution and the second electric field intensity distribution, and outputs the electric field intensity distribution from a display device.

2. A radio wave environment model calculation system as described in claim 1, wherein the processor: acquires from the electromagnetic field calculation engine a first direct wave ray representing a direct wave that collides at a first structure collision point which is the first collision point with the structure polygon after being radiated from a predetermined ray radiation point; acquires from the electromagnetic field calculation engine a second direct wave ray representing a direct wave that collides at a first moving body collision point which is the first collision point with the moving body polygon after being radiated from the ray radiation point; defines the ray having the shorter path length of the first direct wave ray and the second direct wave ray radiated in the same direction from the ray radiation point as a direct wave ray; acquires from the electromagnetic field calculation engine a first reflected wave ray representing a reflected wave that has repeatedly collided with the structure polygon after being reflected at the first structure collision point, and the first electric field intensity distribution based on the first reflected wave ray; a second reflected wave ray representing a reflected wave that has been reflected at the first moving body collision point by the direct wave ray and then repeatedly collides with the moving body polygon, and a second electric field intensity distribution based on the second reflected wave ray are obtained from the electromagnetic field calculation engine.

3. A radio wave environment model calculation system as described in claim 1, characterized in that the radio wave environment model calculation system has a point cloud measurement device that acquires point cloud data regarding the stationary structure, and the processor generates the moving body polygon from the point cloud data regarding the stationary structure acquired by the point cloud measurement device.

4. A radio wave environment model calculation system as described in claim 1, characterized in that the radio wave environment model calculation system has a point cloud measurement device that acquires point cloud data regarding the moving body, and the processor, each time point cloud data regarding the moving body is acquired by the point cloud measurement device, regenerates the moving body polygon from the point cloud data, regenerates the electric field intensity distribution based on the first electric field intensity distribution and the regenerated second electric field intensity distribution, and outputs the regenerated electric field intensity distribution from a display device.

5. A radio wave environment model calculation system as described in claim 1, comprising: an image capturing device for capturing images of the moving body; a database for managing moving body image data in which the image data of the moving body is associated with information on the size and electrical characteristics of the moving body; and an image analysis device having an image diagnosis function unit for comparing the image of the moving body captured by the image capturing device with the image managed in the database to obtain the size and electrical characteristics of the moving body; and wherein the processor generates the moving body polygon from point cloud data regarding the moving body and the size and electrical characteristics of the moving body acquired by the image analysis device.

6. A radio wave environment model calculation system as described in claim 5, characterized in that the radio wave environment model calculation system has a point cloud measurement device that acquires point cloud data regarding the moving body and measures the position and moving speed of the moving body, and the processor estimates the position of the moving body after a predetermined time based on the position and moving speed of the moving body measured by the point cloud measurement device, generates the moving body polygon from the point cloud data regarding the moving body, and acquires the second electric field intensity distribution based on the moving body polygon at the estimated position from the electromagnetic field calculation engine.

7. A radio wave environment model calculation system as described in claim 1, characterized in that the processor assigns IDs in ascending order to each polygon constituting the structure polygon and the moving object polygon so that consecutive IDs are assigned to the closest polygons.

8. A radio wave environment model calculation system as described in claim 1, characterized in that the processor accepts specification of a limited area within the wireless communication service area, limits the area to the limited area, obtains the first electric field intensity distribution from the electromagnetic field calculation engine, and obtains the second electric field intensity distribution from the electromagnetic field calculation engine.

9. A radio wave environment model calculation system as described in claim 2, characterized in that the processor further outputs the direct wave ray, the first reflected wave ray, and the second reflected wave ray from the display device.

10. A radio wave environment model calculation system as described in claim 9, characterized in that the processor further outputs from the display device the position and shape of the stationary structure based on the structure polygon, and the position and shape of the moving body based on the moving body polygon.

11. A radio wave environment model calculation method executed by a radio wave environment model calculation system that calculates an electric field intensity distribution in a wireless communication service area where stationary structures and mobile objects are present, the radio wave environment model calculation system having a processor and a memory, the processor including the following processes: generating a structure polygon representing the stationary structure from point cloud data related to the stationary structure and electrical data representing the electrical characteristics of the stationary structure, generating a mobile body polygon representing the mobile body from the point cloud data related to the mobile body, obtaining a first electric field intensity distribution based on the structure polygon from an electromagnetic field calculation engine, obtaining a second electric field intensity distribution based on the mobile body polygon from the electromagnetic field calculation engine, generating the electric field intensity distribution based on the first electric field intensity distribution and the second electric field intensity distribution, and outputting the electric field intensity distribution from a display device.

12. A radio wave environment model calculation method according to claim 11, wherein the processor: acquires from the electromagnetic field calculation engine a first direct wave ray representing a direct wave that collides at a first structure collision point, which is the first collision point with the structure polygon after being radiated from a predetermined ray radiation point; acquires from the electromagnetic field calculation engine a second direct wave ray representing a direct wave that collides at a first moving body collision point, which is the first collision point with the moving body polygon after being radiated from the ray radiation point; defines the ray having the shorter path length of the first direct wave ray and the second direct wave ray radiated in the same direction from the ray radiation point as the direct wave ray; acquires from the electromagnetic field calculation engine a first reflected wave ray representing a reflected wave that has repeatedly collided with the structure polygon after being reflected at the first structure collision point, and the first electric field intensity distribution based on the first reflected wave ray; and acquiring from the electromagnetic field calculation engine a second reflected wave ray representing a reflected wave that has repeatedly collided with the moving body polygon after the direct wave ray is reflected at the first moving body collision point, and the second electric field intensity distribution based on the second reflected wave ray.

13. A radio wave environment model calculation method as described in claim 11, wherein the radio wave environment model calculation system has a point cloud measurement device that acquires point cloud data regarding the stationary structure, and the processor includes a process of generating the moving body polygon from the point cloud data regarding the stationary structure acquired by the point cloud measurement device.

14. A radio wave environment model calculation method as described in claim 11, wherein the radio wave environment model calculation system has a point cloud measurement device that acquires point cloud data regarding the moving body, and the processor includes the following processes: regenerates the moving body polygon from the point cloud data each time point cloud data regarding the moving body is acquired by the point cloud measurement device, regenerates the electric field intensity distribution based on the first electric field intensity distribution and the regenerated second electric field intensity distribution, and outputs the regenerated electric field intensity distribution from a display device.

15. A radio wave environment model calculation method as described in claim 11, wherein the radio wave environment model calculation system comprises: an image capturing device for capturing images of the moving body; a database for managing moving body image data in which the image data of the moving body is associated with information on the size and electrical characteristics of the moving body; and an image analysis device having an image diagnosis function unit for comparing the image of the moving body captured by the image capturing device with the image managed in the database to obtain the size and the electrical characteristics of the moving body; and wherein the processor includes a process for generating the moving body polygon from point cloud data regarding the moving body and the size and the electrical characteristics of the moving body acquired by the image analysis device.

16. A radio wave environment model calculation method as described in claim 15, wherein the radio wave environment model calculation system has a point cloud measurement device that acquires point cloud data regarding the moving body and measures the position and moving speed of the moving body, and the processor includes the following processes: estimating the position of the moving body after a predetermined time based on the position and moving speed of the moving body measured by the point cloud measurement device; generating the moving body polygon from the point cloud data regarding the moving body; and acquiring the second electric field intensity distribution based on the moving body polygon at the estimated position from the electromagnetic field calculation engine.

17. A radio wave environment model calculation method as described in claim 11, characterized in that the processor includes a process of assigning IDs in ascending order to each polygon constituting the structure polygon and the moving object polygon so that consecutive IDs are assigned to the closest polygons.

18. A radio wave environment model calculation method as described in claim 11, characterized in that the processor includes the following processes: accepting a designation of a limited area within the wireless communication service area; limiting the area to the limited area; acquiring the first electric field intensity distribution from the electromagnetic field calculation engine; and acquiring the second electric field intensity distribution from the electromagnetic field calculation engine.

19. A radio wave environment model calculation method as described in claim 12, characterized in that the processor further includes a process of outputting the direct wave ray, the first reflected wave ray, and the second reflected wave ray from the display device.

20. A radio wave environment model calculation method as described in claim 19, characterized in that the processor further includes a process of outputting from the display device the position and shape of the stationary structure based on the structure polygon and the position and shape of the moving body based on the moving body polygon.

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