Information processing apparatus

Abstract

To estimate a communication quality in a mine with a small calculation amount and relatively high accuracy.SOLUTION: An information processing apparatus comprises: a storage part that stores terrain information 300 indicating a terrain of a mine, position information indicating a position of a transmitting station that transmits radio waves, and a wireless communication parameter related to wireless communication between the transmitting station and a receiving station; and a calculation part that generates a direct wave power map 312 indicating a received power of a direct wave of radio waves transmitted from the transmitting station at each point in the mine, using the terrain information 300, the position information, and the wireless communication parameter. The calculation part corrects the received power at each point in the direct wave power map 312 based on a distance difference between a point in the direct wave power map 312 and one or a plurality of peripheral points around the point and the received power at the peripheral point in the direct wave power map (331).SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an information processing apparatus.

Background Art

[0002] For the purpose of automating mines and the like, there is a need to connect mining machines by wireless communication. It is necessary to maintain wireless communication between the mining machine and the base station regardless of the position where the mining machine moves within the mine or the change in the terrain of the mine due to mining.

[0003] For this purpose, the propagation situation of radio waves is calculated, and the installation plan of the base station is formulated or corrected by estimating the wireless communication quality of each mining machine.

[0004] Patent Document 1 discloses a technique for improving efficiency by sharing information with each other so that the output of the mining plan is used as the input of the network plan and the output of the network plan is used as the input of the mining plan. As an example for creating a network plan, Patent Document 1 exemplifies propagation calculation by ray tracing.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In order to estimate the wireless communication quality, it is necessary to calculate how much the received power is attenuated until the radio wave transmitted from the transmitting station reaches the receiving station.

[0007] For example, ray tracing is one of the calculation methods for the propagation attenuation of this radio wave. In ray tracing, it is necessary to consider many reflected waves in order to accurately calculate the received power. When the entire vast mine is targeted, a very large amount of calculation is required. For this reason, every time the mine terrain changes due to mining or the mining machinery moves, it is difficult to calculate the received power by ray tracing that requires a large amount of calculation. Therefore, it is difficult to calculate the received power following the changes in the mine terrain due to mining and the movement of mining machinery.

[0008] Therefore, the present invention has been made in view of the above problems, and an object thereof is to provide an information processing apparatus capable of estimating communication quality in a mine with a small amount of calculation and relatively high accuracy.

Means for Solving the Problems

[0009] The information processing apparatus according to the present invention includes a storage unit that stores terrain information indicating the terrain of a mine, position information indicating the position of a transmitting station that transmits radio waves, and radio communication parameters related to wireless communication between the transmitting station and a receiving station that receives the radio waves transmitted by the transmitting station, and an arithmetic unit that generates a direct wave power map indicating the received power of the direct wave of the radio wave transmitted from the transmitting station at each point in the mine using the terrain information, position information, and radio communication parameters. The arithmetic unit corrects the received power at each point in the direct wave power map based on the distance difference between the point in the direct wave power map and one or a plurality of surrounding points around the point, and the received power at the surrounding points in the direct wave power map.

Effects of the Invention

[0010] According to the information processing apparatus of the present invention, it is possible to estimate communication quality in a mine with a small amount of calculation and relatively high accuracy.

Brief Description of the Drawings

[0011]

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Best Mode for Carrying Out the Invention

[0012] Hereinafter, this embodiment will be described with reference to the accompanying drawings. In the accompanying drawings, functionally identical elements may sometimes be denoted by the same reference numerals. Note that the accompanying drawings show embodiments and implementation examples in accordance with the principles of the present disclosure, but these are for the purpose of understanding the present disclosure and are by no means used for interpreting the present disclosure in a limiting manner. The description in this specification is merely a typical example and does not limit the scope of the claims or application examples of the present disclosure in any way.

[0013] In this embodiment, although the description is given in sufficient detail for those skilled in the art to implement the present disclosure, other implementations and forms are possible, and it is necessary to understand that changes in configuration and structure and replacement of various elements can be made without departing from the scope and spirit of the technical idea of the present disclosure. Therefore, the following description should not be construed as being limited thereto.

[0014] (Example 1) FIG. 1 is a plan view schematically showing the whole of Mine 1. As shown in FIG. 1, in Mine 1, various mining machines 4 are operating, such as excavation machines like shovels for mining mineral resources, transport machines like dump trucks for transporting the mineral resources excavated by the excavation machines to smelting facilities, and support vehicles for these machines. In this embodiment, the case where the mining machine 4 is a transport machine such as a dump truck will be described.

[0015] In addition, in Mine 1, control equipment 5 communicable with the mining machine 4 is provided. The control equipment 5 receives various information from the mining machine 4 and also transmits various commands such as operation commands and management information to the mining machine 4. Although not shown, a remote operation device for operating the mining machine 4 from outside the mining machine 4 is provided in the control equipment 5. Note that the remote operation device may be provided outside Mine 1.

[0016] In Mine 1, as a communication device between the mining machine 4 and the control equipment 5, a transmitting station 2 that transmits radio waves from the control equipment 5 to the mining machine 4 and receives radio waves from the mining machine 4 to the control equipment 5, and a receiving station 3 that receives the radio waves transmitted from the transmitting station 2 and transmits the radio waves received by the transmitting station 2 are provided.

[0017] The transmitting station 2 is, for example, a fixed station, a base station, an access point, an eNodeB (evolved Node B), etc. For example, the transmitting station 2 is communicably connected to a remote operation device in the control facility 5 through a priority or wireless network. The transmitting station 2 transmits the remote operation instruction received from the remote operation device to the mining machine 4. The receiving station 3 is, for example, mounted on the mining machine 4. The mining machine 4 (receiving station 3) receives the remote operation instruction transmitted from the transmitting station 2 and operates according to the remote operation instruction. The receiving station 3 is, for example, a mobile station, a terminal, a UE (User Equipment), etc. Note that the mining machine 4 may be an unmanned dump truck or a manned dump truck. Also, the receiving station 3 may be provided outside the mining machine 4.

[0018] The information processing device 200 is a device that can communicate with the transmitting station 2 and the receiving station 3. The information processing device 200 may be installed inside the mine 1 or outside the mine 1. The configuration and operation of the information processing device 200 will be described later.

[0019] (Information processing device 200) The information processing apparatus 200 of Example 1 creates a power map indicating the received power at each location in Mine 1. The information processing apparatus 200 is, for example, a personal computer, a smartphone, a tablet, a cloud server, an on-premises server, or the like. As shown in FIG. 2, the information processing apparatus 200 includes an arithmetic unit 201, a memory 202, a storage unit 203, a logic circuit 204, an interface 205, a bus 206, and a communication unit 207. Hereinafter, the interface will be abbreviated as I / F as appropriate. The arithmetic unit 201 is a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), a DSP (Digital Signal Processor), or the like. The memory 202 is a DRAM (Dynamic Random Access Memory) or the like and is used as a work area for the arithmetic unit 201. The storage unit 203 is an HDD (Hard Disk Drive), an SSD (Solid State Drive), or a combination thereof, etc., and stores various programs and various data. The logic circuit 204 is an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or the like. The interface 205 is a device controller that controls the operation of peripheral devices (such as a keyboard, a mouse, a display, etc.) or a network controller that communicates information with external devices.

[0020] The arithmetic unit 201 or the logic circuit 204 is an example of the arithmetic unit of the present invention. The arithmetic unit 201, the logic circuit 204, or a combination thereof executes the direct wave power derivation process 311, the spatial correlation derivation process 321, and the spatial correlation correction process 331 described with reference to FIG. 3.

[0021] The storage unit 203 stores the terrain information 300, the communication station parameters 310, the direct wave power map 312, the received power information 320, the spatial correlation information 322, and the corrected power map 332 described with reference to FIG. 3.

[0022] The communication unit 207 transmits and receives data by communicating with devices outside the information processing apparatus 200. For example, when the storage unit 203 does not store data such as terrain information 300, communication station parameters 310, received power information 320, etc. in advance (or when acquiring them again, etc.), these data are received from a data source and stored in the storage unit 203.

[0023] (Flow of the wireless communication quality estimation method executed by the information processing apparatus 200) With reference to FIG. 3, the flow of the wireless communication quality estimation method executed by the information processing apparatus 200 of the first embodiment will be described. The rectangular blocks in FIG. 3 indicate the processes executed by the information processing apparatus 200, and the parallelogram blocks indicate the data stored by the information processing apparatus 200. In the following description of the wireless communication quality estimation method, the operations are described on the premise that power, gain, and attenuation are each represented by logarithmic values in dB units. For this reason, for example, the addition of power or gain corresponds to multiplication in the true value.

[0024] The information processing apparatus 200 executes a direct wave power derivation process 311 using the terrain information 300 and the communication station parameters 310.

[0025] The terrain information 300 is information indicating the terrain of a mine, and is, for example, DEM (Digital Elevation Model) data including altitude information for each coordinate. The terrain information 300 is created, for example, from detection results by Lidar, Rader, or an optical camera mounted on a drone, an aircraft, or a satellite. The communication unit 207 receives the created terrain information 300 and stores it in the storage unit 203. Alternatively, for example, known terrain information 300 may be stored in the storage unit 203 in advance.

[0026] As shown in FIG. 3A, the communication station parameter 310 includes the location information 350 of the transmitting station 2 and the receiving station 3 (collectively referred to as the communication station), and the wireless communication parameter 360 related to the wireless communication of the communication station. The location information 350 includes the coordinates indicating the location of the transmitting station 2, the height of the antenna of the transmitting station 2, the antenna height of the receiving station 3, etc. In this embodiment, the antenna height of the receiving station 3 corresponds to the height of the antenna when the antenna is mounted on the mining machine 4 (hydraulic shovel or dump truck). The wireless communication parameter 360 includes the transmission power of the radio wave transmitted by the transmitting station 2, the transmitter gain (including the directivity and gain of the antenna of the transmitting station 2), the frequency band, the bandwidth, the receiver gain (including the directivity and gain of the antenna of the receiving station 3), etc. The communication unit 207 receives the data describing these information from an appropriate data source as the communication station parameter 310 and stores it in the storage unit 203. Alternatively, known information may be stored in the storage unit 203 in advance as the communication station parameter 310.

[0027] The direct wave power map 312 is generated by the direct wave power derivation process 311. The direct wave power map 312 shows the received power of the direct wave of the radio wave transmitted from the transmitting station 2 at each point in the mine 1. That is, the direct wave power map 312 shows the power of the direct wave received when the receiving station 3 exists at the coordinates. As shown in FIG. 3B, the direct wave power map 312 is data in which the direct wave power (Pd(x,y)) is associated with the coordinates of each point in the mine 1.

[0028] Also, the information processing device 200 executes the spatial correlation derivation process 321 using the received power information 320.

[0029] The received power information 320 is, for example, the received power value for each coordinate measured by the mining machine 4 (dump truck) traveling in the mine 1 as the receiving station 3. The communication unit 207 receives the measured value from the mining machine 4 by communicating with the mining machine 4, for example, and stores the value in the storage unit 203 as the received power information 320.

[0030] By the spatial correlation derivation process 321, spatial correlation information 322 is generated. The spatial correlation information 322 is information in which the relative distance between two points in Mine 1 and the power difference caused by the relative distance correspond. The larger the value, that is, the larger the power difference, the smaller the correlation. The spatial correlation information 322 may be one value for the entire Mine 1, or different values may be set for each of a plurality of areas within Mine 1. The plurality of areas may be, for example, areas divided by a fixed distance range such as 1 km × 1 km, or areas for each attribute of the area such as a mining area or a transportation route area.

[0031] Then, the information processing apparatus 200 executes a spatial correlation correction process 331 using the terrain information 300, the direct wave power map 312, and the spatial correlation information 322.

[0032] By the spatial correlation correction process 331, a corrected power map 332 is created. The corrected power map 332 indicates the received power of the radio wave transmitted from the transmitting station 2 at each point in Mine 1. That is, the corrected power map 332 indicates the power received when the receiving station 3 exists at the coordinates. As shown in FIG. 3C, the corrected power map 332 is data in which the corrected received power (P(x, y)) is associated with the coordinates of each point in Mine 1.

[0033] (Direct wave power derivation process 311) In the direct wave power derivation process 311, using the terrain information 300 and the communication station parameters 310, a direct wave power map 312 indicating the received power of the direct wave of the radio wave transmitted from the transmitting station 2 at each point in the mine is created. When the following power is expressed in logarithm, the received power (direct wave power) at each point is calculated by the following formula. Direct wave power (Pd(x, y)) = Transmission power + Transmitter gain + Propagation gain + Receiver gain

[0034] Each of the transmitter gain and the receiver gain includes the gain of the antenna of the transmitting station 2 and the gain of the antenna of the receiving station 3. Also, the propagation gain is a value obtained by adding the terrain shielding gain to the distance attenuation × (-1) determined by the distance between the transmitting station 2 and the receiving station 3. The distance attenuation is, for example, the inverse-square attenuation of the distance according to the Friis formula. As shown in FIG. 4, the terrain shielding gain is a value determined by the shielding by the shield 400 between the transmitting station 2 and the receiving station 3. For example, the terrain shielding gain is considered when there is a shield 400 on the straight line 410 connecting the antenna of the transmitting station 2 and the antenna of the receiving station 3 in a straight line.

[0035] (Relationship between terrain shielding and its gain in the direct wave power derivation process) FIG. 5 is a diagram showing the relationship between terrain shielding and its gain in the direct wave power derivation process of FIG. 4. The horizontal axis of each graph in FIG. 5 is a parameter representing the degree to which the shield 400 blocks the line of sight between the transmitting station 2 and the receiving station 3, and the vertical axis is the gain when shielded by the shield 400.

[0036] As shown in FIG. 5(a), regarding the radio wave as a single ray, if the shielding by the shield 400 is below a certain level, the gain may be set to 0, and if it is above a certain level, the gain may be set to -infinity.

[0037] Also, as shown in FIG. 5(b), regarding the radio wave as having a certain spread, the gain may be made to decrease according to the degree of shielding by the shield 400. As an example, the relationship of knife-edge diffraction or its approximate formula may be used.

[0038] Regarding the shield 400, only the shield 400 with the largest degree of shielding between the transmitting station 2 and the receiving station 3 may be calculated, or an approximation such as the Bullington Method that synthesizes a plurality of shields 400 and treats them as a single obstacle may be used, or the gain may be calculated as the synthesis of diffractions by a plurality of shields 400.

[0039] Here, the shielding object 400 includes, for example, the terrain within the mine and the mining machine 4 itself. Therefore, the shielding object 400 that shields between the transmitting station 2 and the receiving station 3 can change over time.

[0040] (Spatial correlation derivation process 321) In the spatial correlation derivation process 321, spatial correlation information 322 is derived in which the relative distance between two points within the mine 1 and the power difference caused by the relative distance correspond to each other.

[0041] In the first embodiment, when the received power (received power information 320) and related information are acquired by the receiving station 3 mounted on the mining machine 4 traveling within the mine 1, the spatial correlation information 322 is derived using the point where the received power was measured and its measured value. FIG. 6(a) is a diagram showing the relationship between the distance difference (horizontal axis) of the coordinates between two points where the received power was acquired and the absolute value of the power difference (vertical axis) for a plurality of received powers acquired by the receiving station 3.

[0042] Based on the relationship in FIG. 6(a), spatial correlation information 322 such as 601, 602, and 603 shown in FIG. 6(b) is created.

[0043] As the spatial correlation information 322, for example, it may be the spatial correlation information 601 of a straight line passing through a power difference = 0 dB and a distance difference = 0 m and having a slope, or it may be the spatial correlation information 602 that has the same slope as the spatial correlation information 601 within a certain value of the distance difference but cuts off when the distance difference is greater than a certain value. Alternatively, it may be the spatial correlation information 603 that is fixed at 0 dB within a certain value of the distance difference and cuts off when the distance difference is greater than a certain value. The value of the spatial correlation information is a power value in dB units.

[0044] For the slopes of the spatial correlation information 601 and 602, the slope that minimizes the least squares error may be selected, or a value obtained by multiplying the slope that minimizes the least squares error by a certain constant such as 0.5 may be selected, or the slope may be selected under the condition that the number of data points below the straight line among all data points is below a certain ratio (for example, 80% or less).

[0045] The cut-off thresholds for the spatial correlation information 602 and 603 can be obtained by, for example, obtaining the slope according to the same rules as those for deriving the slopes of the spatial correlation information 601 and 602 described above, and selecting the distance difference at which the product of the slope and the distance difference is equal to or greater than a certain value, such as 5 dB. Also, the cut-off threshold may be a fixed value (e.g., 10 m), or the smaller value of the product of the slope and the distance difference and the fixed value may be selected.

[0046] (Horizontal direction spatial correlation information, vertical direction spatial correlation information) Regarding the distance difference in FIG. 6, it may be separated into the horizontal direction distance difference and the vertical (altitude) direction distance difference. FIG. 7 is a conceptual diagram of the spatial correlation derivation process 321 when the distance difference in FIG. 6 is separated into the horizontal direction and the vertical direction.

[0047] As shown in FIG. 7(a), for example, considering only the horizontal distance difference on the horizontal axis, the spatial correlation information 601 is derived in the same manner as the method for deriving the spatial correlation information in FIG. 6, and the spatial correlation information in the horizontal direction (horizontal direction spatial correlation information) is derived. Next, for the point 701 with a horizontal distance of 20 m and a vertical distance of 10 m, for example, the power difference 702 from the spatial correlation information 601 corresponding to the horizontal distance of 20 m is obtained. Then, the relationship (b) in which the power difference 702 is associated with the vertical distance on the horizontal axis is obtained. For example, the horizontal axis is associated with a vertical distance of 10 m, and the vertical axis is associated with the value of the power difference 702. In this way, the relationship between the vertical distance and the power difference is derived for each point, and using this relationship, the spatial correlation information corresponding to 601, 602, and 603 in FIG. 6 is created, and the spatial correlation information in the vertical direction is created.

[0048] When creating the relationship between the vertical distance and the received power difference, if the power difference becomes negative during the above derivation process, or if the horizontal distance difference is greater than the cut-off threshold of the spatial correlation information in the horizontal direction, it is not included in the relationship between the vertical distance and the power difference.

[0049] (Spatial correlation correction process 331) In the spatial correlation correction process 331, the value (received power) at each point (each coordinate) of the direct wave power map 312 is smoothed using the values (received powers) at the surrounding coordinates, and the corrected power map 332 is created. At this time, using the terrain information 300, the distance difference between each point and the surrounding coordinates is derived, and based on the spatial correlation information 322, smoothing is performed such that the direct wave power at the coordinates where the power difference corresponding to the derived distance difference is small is strongly affected.

[0050] (Details of the spatial correlation correction process) FIG. 8 is a flowchart showing the details of the spatial correlation correction process. Each step of the flowchart in FIG. 8 may be executed by the arithmetic unit 201 of the information processing apparatus 200 executing a program, or may be executed by the logic circuit 204.

[0051] The information processing apparatus 200 executes the following processes S801 to S806 for all coordinates (x, y) within the mine 1 (S800).

[0052] The information processing apparatus 200 acquires the direct wave power Pd(x, y) of the coordinate (x, y) from the direct wave power map 312 and substitutes it into the corrected received power P(x, y) (S801).

[0053] Next, the information processing apparatus 200 performs a loop process from -N to N for the variables l and j (S802). In this flowchart, a loop process is performed from -N to N for the variables l and j, but a loop process may be performed from -N1 to N1 for the variable l and a loop process may be performed from -N2 to N2 for the variable j.

[0054] The information processing apparatus 200 determines whether the coordinate (x + l, y + j) of the surrounding point of the coordinate (x, y) is outside the range of the mine 1 (S803). If the information processing apparatus 200 determines that the coordinate (x + l, y + j) of the surrounding point is outside the range of the mine 1 (S803: Yes), it returns to S800. On the other hand, if the information processing apparatus 200 determines that the coordinate (x + l, y + j) of the surrounding point is within the range of the mine 1 (S803: No), it executes the process of S804.

[0055] The information processing apparatus 200 calculates the horizontal distance difference and the vertical distance difference between the coordinates (x, y) of the target point and the coordinates (x + l, y + j) of the surrounding point. Then, the information processing apparatus 200 uses the horizontal spatial correlation information to obtain the horizontal direction spatial correlation Ch(l, j) (horizontal power difference) corresponding to the calculated horizontal distance difference, and uses the vertical spatial correlation information to obtain the vertical direction spatial correlation Cv(l, j) (vertical power difference) corresponding to the calculated vertical distance difference (S804).

[0056] Also, the information processing apparatus 200 obtains the direct wave power Pd(x + l, y + j) of the coordinates (x + l, y + j) from the direct wave power map 312 (S805).

[0057] The information processing apparatus 200 calculates the corrected received power (Pd(x + l, y + j) - Ch(l, j) - Cv(l, j)) using the horizontal direction spatial correlation Ch(l, j) and the vertical direction spatial correlation Cv(l, j) obtained in S804, and the direct wave power Pd(x + l, y + j) obtained in S805. Then, the calculated corrected received power (Pd(x + l, y + j) - Ch(l, j) - Cv(l, j)) is compared with the corrected received power P(x, y) substituted in S801. As a result of the comparison, when the corrected received power (Pd(x + l, y + j) - Ch(l, j) - Cv(l, j)) is greater than P(x, y), the corrected received power P(x, y) is updated to Pd(x + l, y + j) - Ch(l, j) - Cv(l, j) (S806). Note that P, Pd, Ch, and Cv are values in dB units, and addition and subtraction are performed in dB units as they are.

[0058] The information processing apparatus 200 determines whether the loop process has ended (S807). If it is determined that the loop process from -N to N for the above-described variables l and j has not been completed, the process returns to S802, and the processes of S803 to S806 are executed for the coordinates (x + l, y + j) of the next surrounding point.

[0059] When the information processing apparatus 200 determines that the loop processing from -N to N for the above-described variables l and j has been completed and determines that the spatial correlation correction processing has not been completed for all coordinates (x, y) in the mine 1, it returns to S801 and executes the processing of S801 to S806 for the next coordinates (x, y).

[0060] When the information processing apparatus 200 determines that the spatial correlation correction processing has been completed for all coordinates (x, y) in the mine 1, it ends this flowchart (S808).

[0061] Note that the order of each process shown in the flowchart of FIG. 8 may be different from the flowchart of FIG. 8 as long as the final result is the same.

[0062] (Effect of Example 1) In Example 1, the corrected power map 332 can be obtained using the direct wave power map 312 that can be calculated with a smaller amount of calculation compared to ray tracing that considers many reflected waves. Also, in Example 1, instead of calculating for the reflected waves, by using the spatial correlation information 322, although it is not as highly accurate as considering many reflected waves, a corrected power map 332 with relatively high accuracy can be obtained compared to the direct wave power map 312. Therefore, in Example 1, the communication quality in the mine 1 can be estimated with a small amount of calculation and relatively high accuracy.

[0063] Also, in Example 1, when the condition of S806 is met, by correcting the direct wave power map 312 using the spatial correlation information 322, there is a possibility that a radio wave unreachable point or a point with a low received power level in the direct wave power map 312 becomes a radio wave reachable point or a point with a high received power level. By comparing the direct wave power map 312 before correction and the corrected power map 332 after correction on a display or the like, it becomes possible to grasp the radio wave situation in a region that cannot be grasped only by the direct wave power map 312.

[0064] By estimating the communication quality as described above, it becomes easier to formulate and modify the network plan of Mine 1, and it is possible to estimate the communication quality in Mine 1 following the fluctuations in the terrain of Mine 1 and the movement of mining machinery that change every moment.

[0065] Furthermore, in a mine having a vast area such as an open-pit mine, a method for estimating the communication quality in Mine 1 with a small amount of calculation and relatively high accuracy is effective.

[0066] (Example 2) In Example 1, a vehicle equipped with a receiving station was driven in Mine 1 to obtain the spatial correlation information 322, but the present invention is not limited to this. The spatial correlation information 322 in Example 2 may be a fixed relationship value referring to, for example, values used in other mines.

[0067] Also, as an initial value, the spatial correlation information 322 with a fixed relationship as in Example 2 may be used, and then it may be changed to derive the spatial correlation information 322 as in the spatial correlation derivation process 321 as in Example 1.

[0068] (Effect of Example 2) In Example 2, since the spatial correlation information 322 used in other mines can be used, it is not necessary to drive a vehicle equipped with a receiving station in Mine 1 as in Example 1. For example, by using the spatial correlation information 322 of mines with similar shapes, etc., it becomes possible to accurately correct the direct wave power map 312. Other effects are the same as those in Example 1.

[0069] (Example 3) When there are a plurality of transmission stations 2 in Mine 1, the processes corresponding to Example 1 and Example 2 are performed for each transmission station 2.

[0070] In Example 3, a corrected power map 332 is created for each of the plurality of transmission stations 2. Then, by the inter-station synthesis process 341, an inter-station synthesis power map 342 corresponding to the communication quality when using the plurality of transmission stations 2 is created using the plurality of corrected power maps 332.

[0071] In the inter-cell combining process 341, for example, a fixed station with the highest received power for each coordinate is selected as the connected fixed station, and assuming that the transmission signals of fixed stations other than the connected fixed station interfere with the signal from the connected fixed station, the signal-to-interference power ratio is estimated, and the signal-to-interference power ratio is used as the inter-cell combined power map.

[0072] (Effect of Embodiment 3) In Embodiment 3, by creating the inter-cell combined power map 342, the communication quality in the mine can be estimated with relatively high accuracy even when there are multiple transmitting stations 2. Other effects are the same as those in Embodiment 1.

[0073] Note that the present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Also, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Also, for a part of the configuration of each embodiment, addition, deletion, or replacement with other configurations is possible. Also, the above-described respective configurations, functions, processing units, processing means, etc. may be realized in hardware by designing a part or all of them, for example, by using an integrated circuit. Also, the above-described respective configurations, functions, etc. may be realized in software by a processor interpreting and executing a program for realizing each function.

[0074] For example, in Embodiment 1, in S804 of FIG. 8, the horizontal spatial correlation Ch(l,j) and the vertical spatial correlation Cv(l,j) are obtained, and in S806, the corrected received power P(x,y) is calculated using the horizontal spatial correlation Ch(l,j) and the vertical spatial correlation Cv(l,j). The present invention is not limited to this, and the spatial correlation may be obtained from the three-dimensional distance difference using any one of 601 to 603 in FIG. 6, and the corrected received power P(x,y) may be calculated using the spatial correlation.

[0075] Note that the transmitting station 2 and the receiving station 3 in the above-described first to third embodiments may be transmitting and receiving stations that transmit and receive radio waves.

[0076] The information processing apparatus according to the present invention stores terrain information indicating the terrain of a mine, position information indicating the position of a transmitting station that transmits radio waves, position information of a receiving station configured to be mounted on a mining machine operating in the mine and receiving radio waves transmitted from the transmitting station, and wireless communication parameters related to wireless communication between the transmitting station and the receiving station; and includes an arithmetic unit that calculates the received power of the direct wave among the radio waves transmitted from the transmitting station at each point in the mine using the terrain information, the position information of the transmitting station, and the wireless communication parameters, and generates a direct wave power map indicating the distribution of the received power at each point based on the calculated values. When information regarding the measured value of the received power of the direct wave when the receiving station mounted on the mining machine receives the direct wave from the transmitting station is newly acquired, the arithmetic unit corrects the received power at each point in the direct wave power map based on the first point at which the received power in the direct wave power map is calculated and its calculated value, the second point at which the received power is measured and its measured value, and the relative distance between the first point and the second point. According to the information processing apparatus of the present invention, it is possible to estimate the communication quality in a mine with a small amount of calculation and relatively high accuracy. Specifically, a corrected power map 332 can be obtained using a direct wave power map 312 that can be calculated with a smaller amount of calculation compared to ray tracing that considers many reflected waves. Therefore, it is possible to estimate the communication quality in the mine 1 with a small amount of calculation and relatively high accuracy.

Description of Reference Numerals

[0077] 1... Mine, 2... Transmitting station, 3... Receiving station, 4... Mining machinery, 5... Control equipment, 200... Information processing device, 201... Arithmetic unit, 202... Memory, 203... Storage unit, 204... Logic circuit, 205... Interface, 206... Bus, 300... Topographic information, 310... Communication station parameters, 311... Direct wave power derivation process, 312... Direct wave power map, 320... Received power information, 321... Spatial correlation derivation process, 322... Spatial correlation information, 331... Spatial correlation correction process, 332... Corrected power map, 341... Inter-station synthesis process, 342... Inter-station synthesis power map, 350... Location information of communication stations, 360... Wireless communication parameters

Claims

1. A storage unit that stores terrain information indicating the terrain of a mine, position information indicating the position of a transmitter that transmits radio waves, position information of a receiver configured to be mounted on mining machinery operating in the mine and receive radio waves transmitted from the transmitter, and wireless communication parameters related to wireless communication between the transmitter and the receiver; An arithmetic unit that calculates the received power at each point in the mine of the direct wave among the radio waves transmitted from the transmitter using the terrain information, the position information of the transmitter, and the wireless communication parameters, and generates a direct wave power map showing the distribution of the received power at each point based on the calculated values; When information regarding the measured value of the received power of the direct wave when the receiver mounted on the mining machinery receives the direct wave from the transmitter is newly acquired, the arithmetic unit uses the first point at which the received power in the direct wave power map is calculated and its calculated value, the second point at which the received power is measured and its measured value, and the relative distance between the first point and the second point to correct the received power at each point in the direct wave power map An information processing apparatus characterized by the above.

2. The storage unit stores spatial correlation information in which the relative distance between two points in the mine corresponds to the power difference caused by the relative distance; The arithmetic unit Uses the spatial correlation information to obtain the power difference caused by the relative distance between the first point and the second point; Based on the received power at the second point in the direct wave power map and the obtained power difference, corrects the received power at each point in the direct wave power map The information processing apparatus according to claim 1, characterized by the above.

3. The spatial correlation information includes horizontal spatial correlation information in which the horizontal relative distance between two points in the mine corresponds to the power difference caused by the horizontal relative distance, and vertical spatial correlation information in which the vertical relative distance between two points in the mine corresponds to the power difference caused by the vertical relative distance; The arithmetic unit Uses the horizontal spatial correlation information to obtain the horizontal power difference corresponding to the horizontal relative distance between the first point and the second point in the direct wave power map, and uses the vertical spatial correlation information to obtain the vertical power difference corresponding to the vertical relative distance between the first point and the second point in the direct wave power map Correcting the received power at each point in the direct-wave power map based on the received power, the horizontal power difference, and the vertical power difference at the second point in the direct-wave power map The information processing apparatus according to claim 2, characterized in that.

4. The spatial correlation information is one piece of information set for the mine or information set for each of a plurality of areas within the mine The information processing apparatus according to claim 2, characterized in that.

5. The plurality of areas are a plurality of areas obtained by dividing the mine within a fixed distance range or areas for each attribute of the mine The information processing apparatus according to claim 4, characterized in that.

6. The spatial correlation information is generated based on the actually measured received power received by a mobile station moving within the mine from the transmitting station The information processing apparatus according to claim 2, characterized in that.

7. The spatial correlation information is the spatial correlation information of another mine different from the mine The information processing apparatus according to claim 2, characterized in that.

8. When a plurality of transmitting stations are provided in the mine, the calculation unit generates a corrected power map in which the received power at each point in the direct-wave power map is corrected for each of the plurality of transmitting stations, and uses the corrected power maps for each of the plurality of transmitting stations to generate a combined power map The information processing apparatus according to claim 1, characterized in that.

9. When the corrected received power calculated by using the received power at the second point in the direct-wave power map and the obtained power difference is greater than the received power at the first point in the direct-wave power map, the calculation unit corrects the received power at the first point in the direct-wave power map to the corrected received power The information processing apparatus according to claim 2, characterized in that.

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