Information processing device, system, method and program

Abstract

To provide an information processing apparatus, a system, a method, and a program, capable of efficiently grasping a propagation environment of signals.SOLUTION: An information processing apparatus according to an embodiment includes a processing unit configured to: acquire first data that includes a first position of a mobile object at a time of receiving a first signal from an antenna or a first distance between the mobile object and the antenna, and a first received power of the first signal; acquire second data that includes a second position of the mobile object at a time of receiving a second signal from the antenna, the second signal being different from the first signal, or a second distance between the mobile object and the antenna, and a second received power of the second signal; and estimate a propagation environment of a signal in a space facing the antenna with the second position interposed therebetween by comparing the first data with the second data.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an information processing device, a system, a method, and a program. [Background technology]

[0002] In recent years, it has become known to control a mobile object (e.g., a mobile robot) that moves within a predetermined space by, for example, executing wireless communication. In this case, the mobile object is controlled to move along a route from a start point to a goal point that is set on a map of the space in which the mobile object moves.

[0003] Incidentally, the control signal for controlling the above-mentioned mobile object is transmitted by radio waves from an antenna, but if an obstacle (radio wave blocking object) is placed in the space in which the mobile object moves, the signal propagation environment in the space opposite the antenna across the obstacle (i.e., the space behind the obstacle as seen from the antenna) may be deteriorated by the obstacle (i.e., a dead zone where the received power is reduced may occur). In such a case, a route that avoids the dead zone can be selected.

[0004] Here, if the above-mentioned obstacle is removed, the signal propagation environment in the dead zone improves (recovers), so the mobile object does not need to move around the dead zone.

[0005] However, it is difficult to efficiently grasp the signal propagation environment in the space in which the mobile object moves (that is, whether the signal propagation environment in a blind area has improved, etc.). [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] Michimi et al., "A Study on Path Control of Autonomous Guided Vehicles Based on Radio Wave Environment Monitoring in Factory Environments," IEICE Technical Report, vol. 120, no. 404, RCS2020-222, pp. 94-99, March 2021 Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, an object of the present invention is to provide an information processing device, system, method, and program that can efficiently grasp the signal propagation environment in a space in which a mobile object moves. [Means for solving the problem]

[0008] The information processing device according to the embodiment includes: A moving object moving between the first space in which the radio wave shield is arranged and the antenna is When the first signal transmitted from the antenna is received The aforementioned a first position of a moving object or a first distance between the moving object and the antenna; And, a first received power of the first signal; and Contains Multiple Acquire the first data, A moving object moving between the second space and the antenna When a second signal different from the first signal transmitted from the antenna is received, The aforementioned a second position of the moving body or a second distance between the moving body and the antenna; And, a second received power of the second signal; and Contains Multiple Acquire second data; Multiple First Data a trend of the first position or the first distance and the first received power in and 、 The aforementioned Multiple Second Data a trend of the second position or the second distance and the second received power in and If there is a difference in , the aforementioned 2 sky Signal propagation environment between When the change The processor includes a processor for estimating the [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing an example of a local 5G system applied to an embodiment. [Figure 2]FIG. 1 is a diagram showing an example of a map of a target space. [Figure 3] FIG. 2 is a diagram for explaining an example of an environment assumed in the present embodiment. [Figure 4] FIG. 2 is a diagram showing an example of the functional configuration of a moving object. [Figure 5] FIG. 2 is a diagram showing an example of the functional configuration of an information processing apparatus. [Figure 6] FIG. 1 is a diagram showing an example of a system configuration of an information processing apparatus. [Figure 7] FIG. 10 is a diagram showing an example of a processing procedure of an information processing apparatus. [Figure 8] 1A and 1B are diagrams for explaining the principle of estimating the signal propagation environment in an estimation target area. [Figure 9] 1A and 1B are diagrams for explaining the principle of estimating the signal propagation environment in an estimation target area. [Figure 10] 1A and 1B are diagrams for explaining the principle of estimating the signal propagation environment in an estimation target area. [Figure 11] 1A and 1B are diagrams for explaining the principle of estimating the signal propagation environment in an estimation target area. [Figure 12] 1A and 1B are diagrams for explaining the principle of estimating the signal propagation environment in an estimation target area. [Figure 13] 1A and 1B are diagrams for explaining the principle of estimating the signal propagation environment in an estimation target area. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments will be described with reference to the drawings. The information processing device according to this embodiment is used to control a mobile object (mobile robot) that moves within a predetermined space (hereinafter referred to as a target space) such as a factory.

[0011] The following describes a scenario in which the information processing device according to this embodiment is applied. When a moving object moves in a straight line along a passage arranged in a target space, simple control of the moving object is sufficient. However, when the moving object is required to perform an action such as turning a curve or avoiding an obstacle, more advanced control is required.

[0012] However, when controlling such moving objects via a wire (i.e., when transmitting control signals for controlling the moving objects via a wire), there are problems such as a limited range in which the moving objects can move, the moving objects becoming uncontrollable due to wire breaks, and the wiring work being cumbersome. These problems become particularly pronounced when a large number of moving objects are moving within the target space.

[0013] On the other hand, when controlling a mobile object wirelessly (i.e., wirelessly controlling a mobile object), the above-mentioned problems can be solved. For example, local 5G can be used for wireless control of such mobile objects. Local 5G is a 5G network that can be used individually by, for example, a company, and is capable of achieving high speed, low latency, and multiple simultaneous connections, making it useful in environments where multiple mobile objects moving within a target space are wirelessly controlled. Note that wireless LAN can also be used for wireless control of mobile objects.

[0014] Here, the above-mentioned mobile objects can be broadly divided into those that operate autonomously and those that operate based on external commands (control signals). Mobile objects that operate autonomously are useful because each mobile object can determine its own situation and act accordingly, but they are expensive and difficult to apply to cases where a large number of mobile objects are placed within a target space. In contrast, mobile objects that operate based on external commands can reduce the total cost of a system including the mobile objects and the information processing device by consolidating the functions for controlling a large number of mobile objects into a single device (e.g., an information processing device). Furthermore, since information about a large number of mobile objects moving within a space can be managed collectively, management of the mobile objects is relatively easy.

[0015] Hereinafter, it is assumed that this embodiment is applied to a local 5G system (cellular system) in which the base station controls the terminal side, as shown in Figure 1.

[0016] The example shown in FIG. 1 assumes a situation in which multiple mobile objects 1 move within a target space. Each of the multiple mobile objects 1 is equipped with a radio and is communicably connected to a base station 2. An information processing device 3 is also connected to the base station 2, and a control signal for controlling the mobile object 1, generated by the information processing device 3, is transmitted from (an antenna installed at) the base station 2 to the mobile object 1. In other words, it can be said that the mobile object 1 is communicably connected to the information processing device 3 via the base station 2. This allows the mobile object 1 to move within the target space based on the control signal generated by the information processing device 3.

[0017] 1, it is assumed that the moving object 1 is, for example, an autonomous mobile robot (AMR), and the information processing device 3 is, for example, a server device called multi-access edge computing (MEC). The information processing device 3 may also be a server device that provides cloud computing services.

[0018] Here, we consider a case where a mobile object 1 is controlled to move within a target space based on (map data showing) a map of the target space shown in Fig. 2. Here, we consider a situation where the mobile object 1 moves from a start point 1b set on the map to a goal point 1c along a passage 1a shown on the map (for example, a travel path set in a factory) in order to transport a load such as a cardboard box.

[0019] In this case, there are three routes for moving from the starting point 1b to the goal point 1c: route 1d, which corresponds to the shortest route; route 1e, which corresponds to the longest route; and route 1f, which corresponds to an intermediate route between the shortest and longest routes.

[0020] According to the map shown in Fig. 2, by selecting route 1d (i.e., the shortest route) from routes 1d to 1f, the mobile object 1 can be controlled to move efficiently from the start point 1b to the goal point 1c. Note that a control signal for controlling the mobile object 1 in this manner is transmitted to the mobile object 1 from, for example, an antenna 2a installed in a base station 2. Note that the antenna 2a is placed, for example, within the target space.

[0021] Here, if the target space in which the moving object 1 moves is, for example, a factory, it is assumed that the arrangement of obstacles (such as cardboard boxes carried by the moving object 1) in the target space will change over time. Here, it is assumed that in a situation in which the moving object 1 repeatedly carries luggage from a start point 1b to a goal point 1c (i.e., multiple moving objects 1 move sequentially along a predetermined route) as shown in Fig. 2, an obstacle 1g is placed in the target space as shown on the left side of Fig. 3.

[0022] If this obstacle 1g is, for example, an object that blocks radio waves (i.e., a cardboard box or the like containing a radio wave blocking object), the signal transmitted from the antenna 2a will be blocked by the obstacle 1g, and the signal propagation environment in the space 1h opposite the antenna 2a across the obstacle 1g will deteriorate (i.e., a dead zone 1h will be created where the received power will decrease).

[0023] 3, a space where the propagation environment is deteriorated (i.e., a dead zone) 1h overlaps with the route 1d, so when the mobile object 1 moves along the route 1d, the mobile object 1 may not be able to properly receive a control signal in the dead zone 1h. In other words, the obstacle 1g placed in the target space as described above becomes a factor that hinders efficient movement (control) of the mobile object 1.

[0024] When a dead zone 1h occurs in this way, the moving object 1 can be controlled to avoid the dead zone 1h by, for example, changing the route 1d to a route 1f (intermediate route) as shown on the right side of FIG.

[0025] Incidentally, in a situation where multiple moving objects 1 repeatedly transport luggage along route 1f changed from route 1d (i.e., multiple moving objects 1 repeatedly move between start point 1b and goal point 1c), if obstacle 1g placed in the target space is removed over time, the (worsening of) the signal propagation environment in blind zone 1h improves, and blind zone 1h disappears. In this case, it is preferable to recognize that blind zone 1h has disappeared and change the route on which moving objects 1 travel from route 1f to route 1d again (i.e., select route 1d again as the appropriate route for moving object 1).

[0026] Here, a method for determining elimination of the blind zone 1h in a comparative example of this embodiment will be described.

[0027] First, at any timing while the mobile object 1 is repeatedly transporting a load along the route 1f, the mobile object 1 is controlled to move along the route 1d, and when the mobile object 1 passes through the blind zone 1h, a synchronization signal is transmitted from the antenna 2a (base station 2). The mobile object 1 receives the synchronization signal transmitted from the antenna 2a and measures the received power of the synchronization signal.

[0028] In the comparative example of this embodiment, if the received power measured in the dead zone 1h is equal to or greater than the threshold value as described above, it can be determined that the dead zone 1h has been eliminated (i.e., the signal propagation environment in the dead zone 1h has improved). On the other hand, if the received power measured in the dead zone 1h is less than the threshold value, it can be determined that the dead zone 1h has not been eliminated.

[0029] However, if the mobile object 1 is moved into the dead zone 1h while the dead zone 1h has not been resolved (i.e., the obstacle 1g has not been removed), the mobile object 1 may not be able to properly receive control signals in the dead zone 1h and may not operate normally (for example, may stop operating). In this case, it may take time for the mobile object 1 to resume normal operation, and it may not be possible to efficiently determine whether the dead zone 1h has been resolved. Furthermore, moving through the dead zone 1h may be a cause of accidents, etc., due to the inability to properly receive control signals (i.e., instructions to change the moving speed and moving direction, etc.).

[0030] Furthermore, for example, by utilizing the reflection of a laser beam emitted from the moving body 1, it is possible to directly detect the presence or absence of an obstacle 1g without moving the moving body 1 into the blind zone 1h.

[0031] However, as described above, in a situation where the mobile object 1 moves through a target space such as a factory, an obstacle 1g may be placed, such as multiple cardboard boxes packed with radio wave blocking materials stacked vertically (i.e., piled up), and the height of the obstacle 1g changes when the cardboard boxes are removed or further stacked. The signal propagation environment is thought to depend on the height of such obstacle 1g. Specifically, even if the obstacle 1g is placed in the position shown in Figure 3, if the height of the obstacle 1g is low (the number of cardboard boxes stacked vertically is small), the blind zone 1h may be eliminated.

[0032] On the other hand, as described above, it is difficult to grasp the height direction of the obstacle 1g due to the linearity of the laser emitted from the moving body 1, and it is not possible to grasp the elimination of the blind zone 1h taking into account the height direction of the obstacle 1g. Although it is possible to apply a mechanism that can grasp the height direction, the cost of building the system will increase when controlling multiple moving bodies 1.

[0033] Furthermore, if the obstacle 1g that is a radio wave shield is replaced with an obstacle that is not a radio wave shield, the dead zone 1h may be eliminated even if the obstacle is still in place.

[0034] That is, even if the presence or absence of an obstacle is detected by utilizing the reflection of the laser emitted from the moving body 1, there are cases in which it is not possible to appropriately grasp whether the blind zone 1h has been eliminated based on the detection result.

[0035] Therefore, in this embodiment, a mobile object control system is described that can estimate (infer) the signal propagation environment in a target zone (space) such as a blind zone while avoiding a situation in which the mobile object 1 cannot operate normally. As shown in Fig. 1 above, the mobile object control system according to this embodiment includes a mobile object 1 (e.g., AMR) and an information processing device 3 (e.g., MEC) communicably connected to the mobile object 1 via a base station 2.

[0036] First, an example of the functional configuration of the moving object 1 will be described with reference to Fig. 4. As shown in Fig. 4, the moving object 1 includes a receiving unit 11, a control unit 12, a distance measuring unit 13, a received power measuring unit 14, and a transmitting unit 15.

[0037] The receiving unit 11 receives a control signal for controlling the mobile object 1. The control signal received by the receiving unit 11 is output to the control unit 12. The receiving unit 11 also receives a synchronization signal for measuring received power, which will be described later. The control signal received by the receiving unit 11 is output to the received power measurement unit 14. The control signal and synchronization signal are transmitted to the mobile object 1 from an antenna installed in the base station 2.

[0038] The control unit 12 controls the moving object 1 based on the control signal output from the receiving unit 11. The moving object 1 is equipped with wheels and the like for moving the moving object 1, and the control unit 12 controls the rotation speed and direction of the wheels (i.e., the moving speed and direction of the moving object 1) in accordance with the control signal, thereby moving the moving object 1. The moving speed and direction of the moving object 1 controlled by the control unit 12 are output to the distance measurement unit 13.

[0039] The distance measurement unit 13 is realized by, for example, an optical distance sensor (LRF: Laser Range Finder) or the like, and measures the distance from the moving object 1 to walls or obstacles present around the moving object 1 based on the time (TOF: Time Of Flight) it takes for a laser (light) emitted from the LRF to be reflected. The distance (LRF scan data indicating) measured by the distance measurement unit 13 and (data indicating) the moving speed and direction of the moving object 1 output from the control unit 12 are output to the transmission unit 15 as data for creating map data (hereinafter referred to as map creation data) to be described later.

[0040] The received power measuring unit 14 measures the received power (power intensity) of the synchronization signal based on the synchronization signal output from the receiving unit 11. The received power data indicating the received power measured by the received power measuring unit 14 is transmitted to the transmitting unit 15.

[0041] The transmitting unit 15 transmits the map creation data output from the distance measuring unit 13 to the information processing device 3. The transmitting unit 15 also transmits the reception power data output from the reception power measuring unit 14 to the information processing device 3.

[0042] Next, an example of the functional configuration of the information processing device 3 will be described with reference to Fig. 5. The information processing device (MEC) 3 according to this embodiment is configured to acquire data from the mobile object 1 side via the base station 2 (or an antenna installed therein) and to instruct the mobile object 1 on the route (travel route) along which the mobile object 1 should move.

[0043] 5, the information processing device 3 includes a processing unit 31 and a storage unit 32. The processing unit 31 also includes an acquisition unit 31a, a map data creation unit 31b, a received power map creation unit 31c, a propagation environment estimation unit 31d, a control unit 31e, and an output unit 31f.

[0044] The map creation data and reception power data transmitted by the transmitter 15 included in the mobile object 1 described above are received by an antenna installed in the base station 2. The acquirer 31a acquires the map creation data and reception power data received by the antenna from the base station 2. The map creation data acquired by the acquirer 31a is output to the map data creator 31b, reception power map creator 31c, and propagation environment estimator 31d, and the reception power data acquired by the acquirer 31a is output to the reception power map creator 31c and propagation environment estimator 31d.

[0045] The map data creation unit 31b creates map data that shows a map of the target space based on the map creation data output from the acquisition unit 31a. The map data created by the map data creation unit 31b is stored in the storage unit 32.

[0046] The reception power map creating unit 31c creates a reception power map of the target space based on the map creation data and reception power data output from the acquiring unit 31a. The reception power map created by the reception power map creating unit 31c is stored in the storage unit 32.

[0047] The propagation environment estimation unit 31d estimates (changes in) the propagation environment of the signal transmitted from the antenna installed in the base station 2 based on the map creation data and the received power data output from the acquisition unit 31a. In this case, the propagation environment estimation unit 31d estimates the signal propagation environment not in the space near the mobile object 1 moving along a predetermined route, but in the space facing the antenna 2a across the mobile object 1 (hereinafter referred to as the estimation target zone). Note that the estimation target zone (space in which the signal propagation environment is estimated) in this embodiment may be, for example, This includes a space where the received power is smaller than a predetermined received power (that is, a space corresponding to a blind zone).

[0048] The control unit 31e generates a control signal for controlling the moving object 1 based on the map data and reception power map stored in the storage unit 32 and the propagation environment estimation result by the propagation environment estimation unit 31d. The control signal generated by the control unit 31e is output to the output unit 31f.

[0049] The output unit 31f outputs the control signal output from the control unit 31e to the base station 2. The control signal output from the output unit 31f in this manner is transmitted to the mobile object 1 from an antenna installed in the base station 2.

[0050] Fig. 6 shows an example of the system configuration of the information processing device 3 shown in Fig. 5. The information processing device 3 includes a CPU 301, a nonvolatile memory 302, a RAM 303, a communication device 304, and the like.

[0051] The CPU 301 is a processor for controlling the operations of various components within the information processing device 3. The CPU 301 may be a single processor or may be configured with multiple processors. The CPU 301 executes various programs loaded from the non-volatile memory 302 to the RAM 303. These programs include an operating system (OS) and various application programs including a propagation environment estimation program 303A.

[0052] The nonvolatile memory 302 is a storage medium used as an auxiliary storage device. The RAM 303 is a storage medium used as a main storage device. Although only the nonvolatile memory 302 and the RAM 303 are shown in Fig. 6, the information processing device 3 may also include other storage devices such as a hard disk drive (HDD) and a solid state drive (SSD).

[0053] The communication device 304 is a device configured to perform wired communication or wireless communication. The information processing device 3 according to this embodiment is assumed to be connected to the base station 2 by wire (cable), but may be connected to the base station 2 via a network to perform wireless communication.

[0054] In this embodiment, the processing unit 31 shown in Fig. 5 is realized by at least one processor. The processor includes, for example, a control device and an arithmetic device, and is realized by analog or digital circuits, etc. The processor may be the above-mentioned CPU 301, or may be a general-purpose processor, a microprocessor, a digital signal processor (DSP), an ASIC, an FPGA, or a combination thereof.

[0055] Note that part or all of the processing unit 31 can be realized by causing the CPU 301 (i.e., the computer of the information processing device 3) to execute the propagation environment estimation program 303A, that is, by software. This propagation environment estimation program 303A may be stored in a computer-readable storage medium and distributed, or may be downloaded to the information processing device 3 via a network. Note that part or all of the processing unit 31 may be realized by dedicated hardware or the like.

[0056] In this embodiment, the storage unit 32 shown in FIG. 5 is realized by, for example, the nonvolatile memory 302 or other storage devices.

[0057] An example of a processing procedure of the information processing device 3 according to this embodiment will be described below with reference to the flowchart of FIG.

[0058] In the information processing device 3 according to this embodiment, a process of creating map data and a reception power map is executed as a pre-processing (preparation) for controlling the moving body 1 (step S1).

[0059] First, the process of creating map data will be described. When the target space (environment) is a relatively static space, it is sufficient to prepare fixed map data showing a map of the target space in advance. However, in a target space such as the above-mentioned factory, the location of obstacles (baggage, etc.) changes over time, so it is necessary to dynamically create (update) map data.

[0060] In this case, the processing unit 31 (control unit 31e) included in the information processing device 3 generates a control signal for controlling the moving body 1 to move throughout the entire range in which the moving body 1 can move within the target space. The control signal (downlink) generated in the processing unit 31 in this manner is output from the processing unit 31 (output unit 31f) to the base station 2 and transmitted to the moving body 1 from an antenna installed in the base station 2. In this case, the control signal is received by the receiving unit 11 included in the moving body 1, and the control unit 12 controls the moving speed and direction of the moving body 1 based on the control signal. As a result, the moving body 1 moves throughout the target space.

[0061] Here, the distance measurement unit 13 included in the moving body 1 measures the distance to objects (e.g., walls, obstacles, etc.) present around the moving body 1 moving within the target space by measuring the TOF using an LRF or the like.

[0062] The transmitter 15 transmits map creation data (uplink) including the distance measured by the distance measurement unit 13 and the moving speed and direction of the moving object 1 controlled by the controller 12 to the information processing device 3 via (an antenna installed in) the base station 2. The map creation data is transmitted to the information processing device 3, for example, every time the moving object 1 moves based on a control signal (that is, for each point in the target space).

[0063] As described above, the map creation data transmitted from the moving object 1 (transmitter 15) is received by an antenna installed in the base station 2 and output to the information processing device 3. The processing device 3 includes a processing unit 31 (acquirer 31a) that acquires the map creation data output from the base station 2. The processing unit 31 (map data creator 31b) creates map data that indicates a map of the target space based on the distance, moving speed, and direction of the moving object 1 included in the acquired map creation data. The map data created by the processing unit 31 in this manner is data that indicates a map such as a plan view that indicates the walls that form the target space, the paths through which the moving object 1 can move, and obstacles located within the target space.

[0064] The map data may be created by updating the initial layout of the target space (map data showing only walls and passages) in which no obstacles or the like are located.

[0065] The map data created by the processing unit 31 (map data creating unit 31b) as described above is stored in the storage unit 32.

[0066] Next, a process for creating a reception power map will be described. In this case, the processing unit 31 (control unit 31e) included in the information processing device 3 generates a control signal for controlling the mobile object 1 to move throughout the entire range in which the mobile object 1 can move within the target space, based on the map indicated by the map data stored in the storage unit 32 as described above. The control signal thus generated in the processing unit 31 is output from the processing unit 31 (output unit 31f) to the base station 2, and transmitted to the mobile object 1 from an antenna installed in the base station 2. As a result, the mobile object 1 moves throughout the target space.

[0067] Here, in 5G (local 5G), a synchronization signal is broadcast from (an antenna installed at) a base station 2. A receiver 11 included in the mobile object 1 receives the synchronization signal broadcast from the base station 2 in this manner.

[0068] The received power measuring unit 14 measures the received power of the synchronization signal received by the receiving unit 11. Note that the received power measured in this embodiment may be, for example, at least one of RSSI (Received Signal Strength Indicator), RSRP (Reference Signal Received Power), SSS-RSRP (Secondary Synchronization Signal-Reference Signal Received Power), and PSS-RSRP (Primary Synchronization Signal-Reference Signal Received Power).

[0069] Also, although the description here assumes that the received power of a synchronization signal broadcast from base station 2 is measured, for example, in 5G (local 5G), multiple reference signals are provided, such as a CSI-RS (Channel State Information-Reference Signal), which is a reference signal for channel information estimation, and a DM-RS (Demodulation Reference Signal), which is a reference signal for demodulation. Therefore, the received power may be measured using these reference signals. In this case, the received power of one of multiple reference signals that differ in at least one of frequency, time, and antenna may be measured, or the average value of the received power of each of the multiple reference signals may be measured.

[0070] The transmitter 15 transmits reception power data indicating the reception power measured by the reception power measuring unit 14 in this manner to the information processing device 3 via (an antenna installed in) the base station 2. Note that the reception power data is transmitted to the information processing device 3 every time the mobile object 1 moves (for each point in the target space) based on, for example, a control signal.

[0071] Furthermore, although detailed explanation will be omitted here, in the process of creating a reception power map, the above-mentioned map creation data (distance to objects present around the moving body 1, and the moving speed and direction of the moving body 1) is transmitted from the moving body 1 to the information processing device 3 each time the moving body 1 moves.

[0072] As described above, the map creation data and received power data transmitted from the mobile object 1 (transmitter 15) are received by an antenna installed in the base station 2 and output to the information processing device 3. The processing unit 31 (acquirer 31a) included in the information processing device 3 acquires the map creation data and received power data output from the base station 2.

[0073] Here, the processing unit 31 can acquire (determine) the position of the mobile unit 1 on the map shown by the map data based on the distance to objects existing around the mobile unit 1, which are included in the map creation data, and the moving speed and direction of the mobile unit 1. The processing unit 31 (received power map creation unit 31c) creates a received power map that maps the position of the mobile unit 1 thus acquired and the received power indicated by the received power data. Specifically, the processing unit 31 creates a received power map (a radio wave map that shows the propagation environment of radio waves in the target space) by assigning the received power measured at each position of the mobile unit 1 to the position (i.e., linking the position and the received power).

[0074] The reception power map created by the processing unit 31 (reception power map creating unit 31c) as described above is stored in the storage unit 32.

[0075] In the process of creating a reception power map, map creation data is used to obtain the position to which the reception power indicated by the reception power data is to be allocated, but the map creation data may also be used to update the map data (i.e., the location of obstacles, etc.) stored in the storage unit 32 described above.

[0076] Here, the process of creating the map data and the process of creating the reception power map have been described separately (i.e., the process has been described as the map data being created first and then the reception power map being created), but the map data and the reception power map may be created simultaneously (in parallel).

[0077] Furthermore, in this embodiment, instead of a received power map, a map may be created that assigns signal throughput and bit error rate to each position on the map, as long as it is possible to grasp the signal (radio wave) propagation environment in the target space.

[0078] When the processing of step S1 is executed, the processing unit 31 (control unit 31e) included in the information processing device 3 selects a route along which the moving body 1 will move within the target space based on the map data and reception power map stored in the storage unit 32 (step S2).

[0079] In step S2, the processing unit 31 calculates the cost of each of a plurality of routes from a start point to a goal point set on a map shown by map data, taking into account the received power in spaces that overlap with the route, and selects the optimal route from among the plurality of routes based on the results of the cost calculation. According to step S2, for example, the shortest route among the plurality of routes that avoids spaces where the signal propagation environment is poor (i.e., blind zones where received power is reduced) is selected. While it is conceivable to suppress the reduction in received power in blind zones by, for example, changing the time or frequency or utilizing spatial diversity, in this embodiment, a route that avoids blind zones is selected, prioritizing more stable operation (motion) of the mobile object 1.

[0080] When the process of step S2 is executed, the processing unit 31 (control unit 31e) controls the moving object 1 to move along the route selected in step S2 (step S3). The control of the moving object 1 in step S3 is realized by outputting a control signal for controlling the moving object 1 generated by the processing unit 31 to the base station 2, and transmitting the control signal to the moving object 1 from an antenna installed in the base station 2.

[0081] Here, when the processing of the above-mentioned step S3 is executed, the mobile body 1 moves from the start point to the goal point along the route selected in step S2, and the mobile body 1 transmits the above-mentioned map creation data and received power data to the information processing device 3 via the base station 2 at each point during the movement.

[0082] In this case, the processing unit 31 (acquisition unit 31a) included in the information processing device 3 acquires from the base station 2 the map creation data and received power data transmitted from the mobile body 1 that moved along the route selected in step S2 (step S4).

[0083] Next, the processing unit 31 (map data creation unit 31b) updates the map data stored in the storage unit 32 based on the map creation data acquired in step S4 (step S5). Note that, since only the map creation data on the route selected in step S2 is acquired in step S4, only the area around the route in the map shown by the map data is updated in step S5.

[0084] Next, the processing unit 31 (reception power map creating unit 31c) updates the reception power map stored in the storage unit 32 based on the map creation data and reception power data acquired in step S4 (step S6).

[0085] Here, in the above-mentioned step S2, a route is selected that avoids blind areas where the reception power is low, but in step S4, only the map creation data and reception power data on the route selected in step S2 are acquired, so in step S6, only the reception power assigned to each position on that route in the reception power map is updated.

[0086] In other words, the reception power map updated in step S6 described above cannot determine whether or not a dead zone on a route where the mobile object 1 is not moving (i.e., a dead zone that occurred in the past) has been resolved.

[0087] It should be noted that a blind zone can be eliminated, for example, by removing an obstacle, and the mobile object 1 in this embodiment is considered to be able to detect the presence or absence of the obstacle using the LRF. However, since the LRF cannot determine, for example, the height of an obstacle, even if the LRF detects an obstacle, the blind zone may be eliminated if the obstacle is low in height. In other words, it is difficult for the LRF to estimate the elimination of a blind zone (i.e., the signal propagation environment in a blind zone that occurred in the past).

[0088] Therefore, in this embodiment, the processing unit 31 (propagation environment estimation unit 31d) determines the space facing the antenna across the mobile object 1 (i.e., the space outside the route traveled by the mobile object 1) as the estimation target zone, and estimates the signal propagation environment (radio wave reception sensitivity) in the estimation target zone (step S7). Note that the estimation target zone corresponds to the zone (space) behind an obstacle that was placed in the past (i.e., an obstacle that caused a blind zone that occurred in the past) as seen from the mobile object 1 moving along the route.

[0089] The processing of step S7 is performed using the position of the moving body 1 obtained based on the map creation data obtained in step S4 above and the received power indicated by the received power data (i.e., the received power of the signal received at that position).

[0090] The principle of estimating the signal propagation environment in the estimation target zone in step S9 will be described below.

[0091] Here, it is assumed that a moving object 1 moves within a target space as shown in Fig. 8. In Fig. 8, it is assumed that the target space 100 is a room of, for example, 9 m (X-axis direction) × 18 m (Y-axis direction) × 3 m (Z-axis direction). It is also assumed that an obstacle (radio wave shield) 101 of, for example, 2 m (X-axis direction) × 1 m (Y-axis direction) × 3 m (Z-axis direction) can be placed near the center of the target space 100.

[0092] In this case, for example, the antenna 2a is placed near the ceiling of the target space (room) 100, and the above-mentioned received power is measured while the mobile object 1 is moved 50 cm at a time in the Y-axis direction along the ground of the target space 100.

[0093] When an obstacle 101 is placed, the space opposite the antenna 2a across the obstacle 101 (i.e., the space behind the obstacle 101 as seen from the antenna 2a) becomes a blind zone because the signal (radio wave) transmitted from the antenna 2a is blocked by the obstacle 101.

[0094] Figure 9 shows the received power (hereinafter referred to as the first received power) measured at each position of the moving body 1 when the above-mentioned obstacle 101 is placed, in a manner that allows comparison with the received power (hereinafter referred to as the second received power) measured at each position of the moving body 1 when the obstacle 101 is not placed.

[0095] In FIG. 9, the horizontal axis represents the position of the moving object 1 (signal receiving point), and the vertical axis represents the received power measured at that position.

[0096] The position of the moving object 1 includes positions Y1 to Y17 on the path from near the end of the target space 100 to approach the obstacle 101 as shown in Fig. 8. In this case, position Y1 is the position farthest from the obstacle 101, and position Y17 is the position closest to the obstacle 101.

[0097] The received power is assumed to be an average value of the received power (for example, RSSI) of synchronization signals received at a plurality of frequencies (for example, 4.8 GHz, 4.825 GHz, 4.85 GHz, 4.875 GHz, and 4.9 GHz).

[0098] 9, for example, there is no significant difference between the first and second received powers from positions Y1 to Y7, but a difference occurs between the first and second received powers from position Y8 onwards. Specifically, when an obstacle 101 is present, a mobile object 1 moving near the obstacle 101 directly receives a signal (synchronization signal) transmitted from the antenna 2a and also receives a wave reflected from (the surface of) the obstacle 101. Therefore, the second received power is greater than the first received power when no obstacle 101 is present.

[0099] In this embodiment, the signal propagation environment in the estimation target zone is estimated by utilizing the tendency of the received power to be affected by the obstacle 101 in the target space 100.

[0100] To explain using Figure 8, for example, the processing unit 31 included in the information processing device 3 stores in advance in the storage unit 32 as comparison data data the position of the moving body 1 when it moves with the obstacle 101 placed therein (hereinafter referred to as the first position) and data including the received power of the signal received at the first position (first received power).

[0101] In this case, the processing unit 31 compares the above-mentioned comparison data with data (hereinafter referred to as propagation environment estimation data) including the position of the moving body 1 (hereinafter referred to as the second position) acquired based on the map creation data acquired in step S4 and the received power (second received power) indicated by the received power data, thereby determining whether or not there is a difference as described in Figure 9 above (i.e., whether or not there is a reflected wave from the obstacle 101).

[0102] If it is determined that there is no difference between the comparison data (first position and first received power) and the propagation environment estimation data (second position and second received power), the processing unit 31 can estimate that the signal propagation environment in the estimation target area (here, the space behind the obstacle 101) has not changed (i.e., the obstacle 101 is still present and the blind area has not been resolved). Note that "there is no difference between the comparison data and the propagation environment estimation data" does not simply mean that the comparison data and the propagation environment estimation data are completely identical, but also includes the difference being within a predetermined range. When the comparison data (first position and first received power) and the propagation environment estimation data (second position and second received power) are compared as in this embodiment, if the difference between the first received power and the second received power at the same position is equal to or less than a predetermined value, it is deemed that there is "no difference between the comparison data and the propagation environment estimation data." Furthermore, "the blind zone has not been resolved" means that the received power of the signal by the moving object 1 in the estimation target zone is smaller than a predetermined received power.

[0103] On the other hand, if it is determined that there is a difference between the comparison data and the propagation environment estimation data, the processing unit 31 can estimate that the signal propagation environment in the estimation target zone has changed (i.e., the obstacle 101 has been removed and the blind zone has been eliminated). Note that "there is a difference between the comparison data and the propagation environment estimation data" does not simply mean that the comparison data and the propagation environment estimation data do not completely match, but rather that the difference is outside a predetermined range. In this embodiment, when the comparison data (first position and first received power) is compared with the propagation environment estimation data (second position and second received power), if the difference between the first received power and the second received power at the same position exceeds a predetermined value, it is deemed that there is a "difference between the comparison data and the propagation environment estimation data." Furthermore, "the blind zone has been eliminated" means that the received power of the signal by the mobile object 1 in the estimation target zone is greater than a predetermined received power.

[0104] That is, in this embodiment, it is possible to estimate (changes in) the signal propagation environment in the estimation target area by comparing the received power measured at different times (timings) at the same position. Note that the above positions Y1 to Y17 are spaced 50 cm apart, but for example, any position within ±25 cm of position Yn (n=1, 2, ..., 17) is considered to be position Yn (the same position).

[0105] Next, let us consider a case where a moving object 1 moves within a target space as shown in Fig. 10. In Fig. 10, it is assumed that the target space 200 is a room (conference room) in an office environment. It should be noted that it is possible to place an obstacle 201 such as a partition within the target space 200.

[0106] 10, for example, an antenna 2a (a wireless LAN access point in the 5 GHz band) is placed at a height of 2.25 m on the rear side of the protective wall 202, and a mobile object 1 (terminal) that receives a beacon (control signal) moves in a space opposite the antenna 2a across the protective wall 202. Note that the access point side is configured as a single antenna, and the mobile object 1 (terminal) side is configured as a multi-antenna (i.e., diversity is applied).

[0107] Here, it is assumed that the moving object 1 moves along each of the routes 211 to 213 extending in the X-axis direction. It is assumed that the moving object 1 moves at a constant speed of 0.1 m / s at a position at a height of 0.2 m.

[0108] FIG. 11 shows an example of the received power measured at each position of a moving object 1 moving along a route 211. FIG. 12 shows an example of the received power measured at each position of a moving object 1 moving along a route 212. FIG. 13 shows an example of the received power measured at each position of a moving object 1 moving along a route 213. Note that while the horizontal axis in FIG. 9 above is described as representing the position of the moving object 1, in FIGS. 11 to 13 the horizontal axis represents the distance between the moving object 1 and the antenna 2a (access point) obtained (calculated) from the position of the moving object 1 and the known position of the antenna 2a. Also shown in FIGS. 11 to 13 are regression lines of the received power as a function of the distance between the moving object 1 and the antenna 2a.

[0109] First, when the mobile object 1 moves along the routes 211 and 212, each position on the routes 211 and 212 is within the line of sight of the antenna 2a, and the obstacle 201 does not affect the received power of the signal received by the mobile object 1. For this reason, the received power shown in Figures 11 and 12 tends to decrease (attenuate) as the distance between the mobile object 1 and the antenna 2a increases (i.e., as the mobile object 1 moves away from the antenna 2a).

[0110] In contrast, when the moving object 1 moves along the route 213, each position on the route 213 up until it passes by the obstacle 201 is within the line of sight as seen from the antenna 2a, but each position on the route 213 after it passes by the obstacle 201 is outside the line of sight as seen from the antenna 2a. In other words, the received power shown in Fig. 13 changes significantly at the timing when the line of sight changes from within the line of sight to outside the line of sight at the position of the obstacle 201. Specifically, according to FIG. 13, while the mobile body 1 is approaching the obstacle 201, the received power decreases (attenuates) as the distance between the mobile body 1 and the antenna 2a increases, but just before the obstacle 201 as viewed from the antenna 2a side, the received power increases due to the influence of reflected waves from the obstacle 201 (or its surface) (i.e., the waves reflected by the obstacle 201 act in a direction that reinforces their intensity), and once the mobile body 1 has passed the obstacle 201 as viewed from the antenna 2a side, the signal is blocked by the obstacle 201 (the line of sight from the antenna 2a is blocked, and direct waves cannot reach the mobile body 1), causing the received power to drop sharply.

[0111] In other words, there is a difference between the received power measured at each position of the moving body 1 moving along the routes 211 and 212 that are not affected by the obstacle 201 and the received power measured at each position of the moving body 1 moving along the route 213 that is affected by the obstacle 201.

[0112] In this embodiment, the signal propagation environment in the estimation target zone is estimated by utilizing the tendency of the received power to be affected by the obstacle 201 in the target space 200.

[0113] 10, for example, the processing unit 31 included in the information processing device 3 compares comparison data including a distance (first distance) from the antenna 2a of the moving object 1 moving along the route 211 or 212 and a received power of a signal received at the first distance (first received power) with propagation environment estimation data including a distance (second distance) from the antenna 2a of the moving object 1 moving along the route 213 and a received power of a signal received at the second distance (second received power), thereby determining whether or not there is a difference as described above in FIGS. 11 to 13 (i.e., whether or not there is a reflected wave from the obstacle 201). Note that the comparison data may be acquired based on, for example, map creation data and received power data transmitted from the moving object 1 when the moving object 1 moves along the route 211 or 212, and the propagation environment estimation data may be acquired based on, for example, map creation data and received power data transmitted from the moving object 1 when the moving object 1 moves along the route 213.

[0114] If it is determined that there is a difference between the comparison data (first distance and first received power) and the propagation environment estimation data (second distance and second received power), the processing unit 31 can estimate that the signal propagation environment in the estimation target area (here, the space behind the obstacle 201) has not changed (i.e., the obstacle 201 is still in place and the blind area has not been eliminated).

[0115] On the other hand, if it is determined that there is no difference between the comparison data and the propagation environment estimation data, the processing unit 31 can estimate that the signal propagation environment in the estimation target area has changed (i.e., the obstacle 201 has been removed and the blind area has been eliminated).

[0116] That is, in this embodiment, by comparing the received power measured at positions at the same distance from the antenna 2a (i.e., different positions), it is possible to estimate the signal propagation environment (changes in the environment) in the area to be estimated.

[0117] For example, FIG. 13 shows the received power measured at a position beyond the obstacle 201. However, as described above, when the obstacle 201 is located, a difference arises due to the phenomenon that the received power increases immediately before the obstacle 201. Therefore, in order to obtain the propagation environment estimation data described above, it is not necessary for the mobile body 1 to move to a position beyond the obstacle 201 (i.e., a blind zone) to measure the received power.

[0118] As described above, in step S7 shown in FIG. 7, by focusing on the fact that the received power increases due to reflected waves from the surface of an obstacle (radio wave shield), the comparison data is compared with the propagation environment estimation data to estimate the signal propagation environment in the estimation target area (i.e., the space corresponding to the back side of the obstacle) facing the antenna across the mobile body 1.

[0119] When the process of step S7 is executed, the processing unit 31 (received power map creation unit 31c) reflects the result of the process of step S7 (i.e., the estimation result of the propagation environment) in the received power map (step S8). Specifically, in step S8, if it is estimated in step S7 as described above that the signal propagation environment in the estimation target zone has improved (i.e., the blind zone has been eliminated), a process is executed to reflect the elimination of the blind zone in the received power map (i.e., to update the received power map so as to increase the received power allocated to the blind zone).

[0120] After the processing of step S8 described above is executed, the process returns to step S2 and is repeated. According to this, if a dead zone occurs in the reception power map updated in step S6 due to the placement of a new obstacle, for example, a route that avoids the dead zone is selected in step S2 that is repeatedly executed. Furthermore, although a route that avoids the dead zone is selected in step S2 described above, if the dead zone has been eliminated (that is, the elimination of the dead zone is reflected in the reception power map), a route that passes through the space that was the dead zone can be selected in step S2 that is repeatedly executed.

[0121] In Figure 7, a situation is assumed in which the moving body 1 repeatedly moves along a route from a start point to a goal point set on a map shown by map data, for example. The processing shown in Figure 7 may be terminated, for example, at the timing when predetermined control of the moving body 1 (i.e., the transport of luggage by the moving body 1, etc.) ends.

[0122] Furthermore, in the process shown in FIG. 7, the estimation result of the propagation environment in the estimation target area in step S7 is described as being used to control the mobile body 1 (route selection), but the estimation result may be used for other processing, or may be output from the information processing device 3 to an external device for use in processing executed in the external device.

[0123] Hereinafter, a specific example of the operation of the information processing device 3 according to this embodiment will be described using the examples shown in FIGS. 2 and 3 above.

[0124] First, map data showing the map shown in Fig. 2 is created by moving the mobile object 1 within the target space. Then, although not shown, a reception power map is created in which the reception power measured at each position on the map shown by the map data is assigned to that position. Note that it is assumed that the reception power map created here does not have any dead zones where reception power is reduced (spaces where the signal propagation environment is deteriorated).

[0125] Next, based on the map data and the reception power map, a route for the moving object 1 to travel is selected. Here, it is assumed that the route 1d shown in Fig. 2 is selected.

[0126] When the route 1d is selected as described above, the moving object 1 is controlled to move (carry the luggage) from the start point 1b to the goal point 1c along the route 1d.

[0127] While the moving object 1 is moving along the route 1d, the moving object 1 transmits map creation data and received power data at each position on the route 1d. In this case, the map data and received power map are updated based on the map creation data and received power data transmitted from the moving object 1.

[0128] Here, it is assumed that an obstacle 1g is placed in the target space while the mobile object 1 is moving along the route 1d, as shown in Fig. 3. In this case, a blind zone 1h occurs, and the received power map is updated by allocating reduced received power to the position overlapping with the blind zone 1h.

[0129] According to such a reception power map, a route 1f that avoids the blind zone 1h is selected as the route for the moving body 1 to travel, and the moving body 1 is controlled to move from the start point 1b to the goal point 1c along the route 1f.

[0130] The moving object 1 transmits map creation data and received power data at each position on the route 1f while moving along the route 1f. In this case, the map data and received power map are updated based on the map creation data and received power data transmitted from the moving object 1.

[0131] Furthermore, by comparing the prepared comparison data with the propagation environment estimation data (i.e., the propagation environment estimation data including the position of the mobile body 1 and the received power measured at that position) obtained based on the map creation data and received power data transmitted at each position on the route 1f as described above, the signal propagation environment in the estimation target area (the space facing the antenna 2a across the mobile body 1) is estimated.

[0132] In this case, for example, when the moving object 1 passes between the obstacle 1g and the antenna 2a (i.e., in front of the obstacle 1g as seen from the antenna 2a) without the obstacle 1g being removed, the received power measured will be increased due to the influence of the reflected wave from the obstacle 1g. The presence or absence of such a reflected wave is determined by comparing the above-mentioned comparison data with the propagation environment estimation data. If it is determined that the reflected wave is present, it can be assumed that the obstacle 1g is present and the blind zone 1h behind the obstacle 1g has not been eliminated (i.e., the received power of the signal is lower than the predetermined received power). On the other hand, if it is determined that the reflected wave is not present, it can be assumed that the obstacle 1g is not present (has already been removed) and the blind zone 1h behind the position where the obstacle 1g was present has been eliminated (i.e., the received power of the signal is higher than the predetermined received power).

[0133] The comparison data is, for example, data including each position on the route 1f and the received power measured at that position when the obstacle 1g is placed or when the obstacle 1g is not placed, but any data can be used as long as it is possible to determine the presence or absence of a reflected wave from the obstacle 1g. In other words, the comparison data may be data including each position on a route other than the route 1f and the received power measured at that position, or may be data (sample data) prepared in advance before the moving object 1 moves through the target space.

[0134] When it is estimated that the dead zone 1h has been eliminated as described above, the reception power map is updated so as to increase the reception power allocated to the dead zone 1h (i.e., the estimation result is reflected in the reception power map). According to such a reception power map, it becomes possible to select the route 1d again instead of the route 1f, and move the mobile object 1 along the shortest route (i.e., the route passing through the space 1h).

[0135] As described above, in this embodiment, comparison data (first data) including a first position of the mobile body 1 when a first signal is received and a first reception power of the first signal is obtained, and propagation environment estimation data (second data) including a second position of the mobile body 1 when a second signal different from the first signal is received and a second reception power of the second signal is obtained, and the comparison data and the propagation environment estimation data are compared to estimate the signal propagation environment in the space opposite the antenna that transmitted the first and second signals across the mobile body 1 (i.e., the space behind the mobile body 1 as seen from the antenna). Note that the comparison data may be stored in the storage unit 32, for example.

[0136] That is, in this embodiment, when a mobile body 1 moves through a space where the arrangement of obstacles (e.g., luggage such as cardboard boxes) changes over time, the signal propagation environment in the space behind the mobile body 1 (i.e., the estimation target area) as seen from the antenna is estimated (i.e., the presence or absence of obstacles that block radio waves is detected) based on the relationship between the position of the mobile body 1 (mobile radio) obtained by utilizing wireless communication and the received power of the signal received at that position.

[0137] In this embodiment, the above-described configuration makes it possible to efficiently grasp the signal propagation environment.

[0138] Specifically, according to this embodiment, in a situation where a dead zone occurs and the mobile object 1 is controlled by selecting a route that avoids the dead zone, it is possible to estimate the signal propagation environment in the estimation target zone corresponding to the dead zone based on the received power measured at a position where there is no obstacle between the antenna and the dead zone (i.e., an environment where there is no obstacle between the antenna and each of the first and second positions), without moving the mobile object 1 into the dead zone. That is, in this embodiment, the mobile object 1 only needs to move within a space that is within the line of sight as seen from the antenna, and it is possible to avoid a situation where the mobile object 1 would not operate normally if it were moved into the dead zone to understand the signal propagation environment, for example.

[0139] In this embodiment, a control signal is output based on the propagation environment estimated as described above to control the mobile object 1. Specifically, a reception power map (first map) is created by mapping the first position and first reception power described above, and the reception power map is updated based on the second position, the second reception power, and the estimated propagation environment (i.e., the first map is updated to the second map), and the mobile object 1 is controlled (a route along which the mobile object 1 will move is selected) based on the updated reception power map (second map).

[0140] This allows for the selection of a route that avoids spaces with a poor signal propagation environment and passes through spaces with an improved signal propagation environment, thereby enabling efficient control of the moving body 1 (transportation of luggage).

[0141] In this embodiment, the received power map created by allocating the received power measured at a position of the moving object 1 (the received power of a signal received at that position) to that position has been mainly described, but the received power map may also be data in which obstacles detected by measuring TOF with an LRF or the like are further mapped as described above. Also, the map data and received power map in this embodiment may be output (displayed) so as to be referable to, for example, an administrator who manages the moving object 1 and the information processing device 3, etc.

[0142] Furthermore, the comparison data in this embodiment includes a first received power of a first signal received by the mobile object 1 at a first location at a first time, and the propagation environment estimation data includes a second received power of a second signal received by the mobile object 1 at a second location that is the same as the first location at a second time that is different from the first time. That is, the comparison data and the propagation environment estimation data in this embodiment may be data that includes received power measured at the same location but at different times, as described above with reference to Figures 8 and 9. Note that in this embodiment, "a second location that is the same as the first location" includes a situation where the difference between the first location and the second location is less than a predetermined distance.

[0143] However, the comparison data and the propagation environment estimation data may be data including received power measured at different positions, as explained above with reference to Figures 10 to 13. Furthermore, in order to utilize the distance attenuation characteristics of signals (radio waves), the comparison data and the propagation environment estimation data may be data including distances (first and second distances) between the mobile body 1 and the antenna, acquired based on the position of the mobile body 1 (and the antenna), instead of the position (first and second positions) of the mobile body 1.

[0144] In this embodiment, the comparison data may be data that has been prepared from the perspective of being able to easily detect the presence of an obstacle (radio wave obstruction) or the removal of the obstacle by comparing it with the propagation environment estimation data (i.e., to easily estimate the signal propagation environment in the area to be estimated).

[0145] In this embodiment, the comparison data is compared with the propagation environment estimation data to determine whether or not there are reflected waves from obstacles located within the target space (i.e., changes in received power due to the reflected waves), and the signal propagation environment in the target area is estimated based on the determination result.

[0146] Here, in this embodiment, an obstacle is assumed to be, for example, a cardboard box, but a physical obstacle is different from an obstacle to a signal (radio wave). For example, if the object packed in the cardboard box that is an obstacle is made of plastic or the like, the signal will not be blocked by the obstacle, and a dead zone will not occur. On the other hand, if the object packed in the cardboard box that is an obstacle is made of metal or the like (a radio wave blocking object), the signal will be blocked by the obstacle, and a dead zone will occur.

[0147] In this embodiment, the signal propagation environment in the target area is estimated based on the determination result of the presence or absence of reflected waves from obstacles, as described above. Therefore, the signal propagation environment in the target area can be estimated taking into account, for example, whether the obstacle is a radio wave blocker. This allows for high specificity of phenomena affecting the propagation environment. That is, in this embodiment, if a reflected wave is present, the obstacle is a radio wave blocker, and it can be inferred that the signal propagation environment behind the obstacle as seen from the antenna is deteriorated. On the other hand, even if an obstacle is present, if a reflected wave is not present, it can be inferred that there is no radio wave blocker, and the signal propagation environment behind the obstacle as seen from the antenna is not deteriorated (i.e., is good). Note that this embodiment assumes an environment in which multiple obstacles may be present in the target space, and the status of the obstacles (loads) changes over time. However, the time-varying received power map reflecting the estimation result of the signal propagation environment in the target area described above makes it possible to identify obstacles that may act as radio wave blockers without requiring additional information about the obstacles.

[0148] Furthermore, the occurrence or elimination of a dead zone depends on the height of an obstacle (a radio wave blocking object), and it is thought that if the height of the obstacle is low, the impact of the reflected waves from the obstacle on the received power will be small, and if the height of the obstacle is high, the impact of the reflected waves from the obstacle on the received power will be large. For this reason, in this embodiment, by utilizing the degree of difference between the above-mentioned comparison data and the propagation environment estimation data (i.e., the magnitude of the impact of the reflected waves from the obstacle on the received power), it is possible to estimate the signal propagation environment in the estimation target zone taking into account the height of the obstacle.

[0149] Furthermore, in this embodiment, it is possible to detect obstacles located within the target space (measure the distance to the obstacle) by measuring the TOF using, for example, an LRF or the like. Although it is unclear whether the detected obstacle is a radio wave blocking object or not, a configuration may be adopted in which the process of estimating the signal propagation environment in the estimation target zone is executed only when the mobile object 1 moves near the detected obstacle (i.e., the propagation environment is estimated based on the obstacles located within the target space). With such a configuration, it is possible to reduce the load of the process of estimating the signal propagation environment in the estimation target zone.

[0150] Although this embodiment relates to a technology for indirectly estimating the signal propagation environment in a space where reception power is reduced (dead zone), in this embodiment, in an environment where multiple mobile bodies 1 (e.g., AMR) move within a target space, if there is a possibility that reception power will be reduced behind an obstacle (radio wave shield), the multiple mobile bodies 1 may be made to operate in cooperation. For example, when a first mobile body 1 moves through a space where reception power may be reduced, the second mobile body 1 may assist the operation of the first mobile body 1 by moving through a space within line of sight as seen from the first mobile body 1.

[0151] In addition, in the present embodiment, when a dead zone occurs due to the placement of an obstacle (radio wave blocking object), a route that avoids the dead zone is selected. However, a mechanism that improves the signal propagation environment in the dead zone may be combined with the present embodiment. For example, if significantly different frequency bands such as 900 MHz and 5 GHz can be utilized, the frequency band may be switched (e.g., the 5 GHz frequency band is switched to the 900 MHz frequency band) when an obstacle (radio wave blocking object) is detected, thereby allowing radio waves to go around and eliminating the decrease in received power behind the obstacle.

[0152] In this embodiment, the processing unit 31 included in the information processing device 3 has been described as including the units 31a to 31f, but some of the units 31a to 31f may be located outside the processing unit 31.

[0153] Furthermore, some of the units 31a to 31f included in the processing unit 31 may be omitted. Specifically, the information processing device 3 according to this embodiment only needs to be configured to estimate at least the signal propagation environment in the estimation target zone, and for example, the configuration for controlling the moving object 1 (for example, the control unit 31e) may be omitted.

[0154] Furthermore, in the present embodiment, the information processing device 3 has been described as being one device, but the information processing device 3 may be realized by a plurality of devices.

[0155] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention described in the claims and their equivalents.

[0156] The following additional notes are provided regarding the above-described embodiment. [1] acquiring first data including a first position of the mobile object or a first distance between the mobile object and the antenna when a first signal transmitted from the antenna is received, and a first reception power of the first signal; acquiring second data including a second position of the moving object or a second distance between the moving object and the antenna when a second signal different from the first signal transmitted from the antenna is received, and a second reception power of the second signal; By comparing the first data with the second data, a signal propagation environment in a space facing the antenna across the second position is estimated. Equipped with a processing unit Information processing device. [2] The information processing device according to [1], wherein the processing unit outputs a control signal for controlling the mobile object based on the estimated propagation environment. [3] The processing unit creating a first map that maps the first position and the first received power; updating the first map to a second map based on the second position, the second received power, and the estimated propagation environment; Controlling the moving object based on the second map [2] The information processing device described above. [4] the first received power is affected by an object disposed between the first position and a space in which a propagation environment of the signal is estimated; and The processing unit If a difference between the first data and the second data is within a predetermined range, it is estimated that a received power of a signal by the moving object in the space will be smaller than a predetermined received power; If the difference between the first data and the second data is outside a predetermined range, it is estimated that the received power of the signal by the moving object in the space will be greater than a predetermined received power. The information processing device according to any one of [1] to [3]. [5] The processing unit When it is estimated that the received power of the signal by the moving object in the space will be smaller than a predetermined received power, the moving object is controlled to move along a route that avoids the space; When it is estimated that the received power of the signal by the moving object in the space will be greater than a predetermined received power, the moving object is controlled to move along a path passing through the space. [4] The information processing device described above. [6] further comprising a storage unit that stores the first data; When the second data is acquired, the processing unit estimates the propagation environment by comparing the first data stored in the storage unit with the second data. The information processing device according to any one of [1] to [5]. [7] The information processing device according to any one of [1] to [6], wherein no object that blocks signals is placed between the antenna and each of the first and second positions. [8] the first data includes a first reception power of a first signal received by the mobile device at the first location at a first time; The second data includes second reception power of a second signal received by the moving object at a second position identical to the first position and at a second time different from the first time. The first position and the second position are the same position. The information processing device according to any one of [1] to [7]. [9] The information processing device according to any one of [1] to

[88] , wherein the processing unit determines whether or not there is a reflected wave from an object located in the space in which the moving body is moving by comparing the first data with the second data, and estimates the propagation environment based on the determination result.

[10] the moving body detects an object disposed in a space in which the moving body moves, The processing unit estimates the propagation environment based on the detected object. The information processing device according to any one of [1] to [9].

[11] The information processing device according to

[10] , wherein the object is detected based on the reflection of a laser beam emitted from the moving body.

[12] The information processing device according to any one of [1] to

[11] , wherein the space in which the propagation environment of the signal is estimated includes a space in which the received power of the signal is smaller than a predetermined received power.

[13] The information processing device according to any one of [1] to

[12] , wherein the first received power is affected by an object placed between the first position and a space in which the signal propagation environment is estimated.

[14] [1] to

[13] , and an information processing device according to any one of the above. a mobile object communicably connected to the information processing device; A system comprising:

[14] acquiring first data including a first position of the mobile object or a first distance between the mobile object and the antenna when a first signal transmitted from the antenna is received, and a first reception power of the first signal; acquiring second data including a second position of the moving object or a second distance between the moving object and the antenna when a second signal different from the first signal transmitted from the antenna is received, and a second reception power of the second signal; By comparing the first data with the second data, a signal propagation environment in a space facing the antenna across the second position is estimated. method.

[16] On the computer, acquiring first data including a first position of the mobile object or a first distance between the mobile object and the antenna when a first signal transmitted from the antenna is received, and a first reception power of the first signal; acquiring second data including a second position of the mobile object or a second distance between the mobile object and the antenna when a second signal different from the first signal transmitted from the antenna is received, and a second reception power of the second signal; estimating a signal propagation environment in a space facing the antenna across the second position by comparing the first data with the second data; A program to execute. [Explanation of symbols]

[0157] 1...mobile body, 2...base station, 3...information processing device, 11...receiving unit, 12...control unit, 13...distance measurement unit, 14...received power measurement unit, 15...transmitting unit, 31...processing unit, 31a...acquisition unit, 31b...map data creation unit, 31c...received power map creation unit, 31d...propagation environment estimation unit, 31e...control unit, 31f...output unit, 32...storage unit, 301...CPU, 302...non-volatile memory, 303...RAM, 303A...propagation environment estimation program, 304...communication device.

Claims

1. A plurality of first data are acquired, the first data including a first position of a moving body moving between a first space in which a radio wave shield is placed and an antenna when the moving body receives a first signal transmitted from the antenna or a first distance between the moving body and the antenna, and a first reception power of the first signal; acquiring a plurality of second data including a second position of the moving body or a second distance between the moving body and the antenna when the moving body moving between the second space and the antenna receives a second signal different from the first signal transmitted from the antenna, and a second reception power of the second signal; When there is a difference between a trend of the first position or the first distance and the first reception power in the plurality of first data and a trend of the second position or the second distance and the second reception power in the plurality of second data, it is estimated that a propagation environment of the signal in the second space has changed. Equipped with a processing unit Information processing device.

2. The information processing apparatus according to claim 1 , wherein the processing unit outputs a control signal for controlling the mobile object based on the estimated propagation environment.

3. The processing unit creating a first map that maps the first position and the first received power; updating the first map to a second map based on the second location, the second received power, and the estimated propagation environment; Controlling the moving object based on the second map 3. The information processing device according to claim 2.

4. The processing unit When it is estimated that the propagation environment has not changed in the second space, the mobile object is controlled to move along a route that avoids the second space; When it is estimated that the propagation environment has changed in the second space, the mobile object is controlled to move along a route that passes through the second space.

2. The information processing device according to claim 1.

5. further comprising a storage unit that stores the plurality of first data; When the plurality of second data are acquired, the processing unit compares a trend of the first position or the first distance and the first received power in the plurality of first data stored in the storage unit with a trend of the second position or the second distance and the second received power in the plurality of second data.

2. The information processing device according to claim 1.

6. the first data includes a first received power of a first signal received by the mobile device at the first location at a first time; the second data includes second reception power of a second signal received by the mobile object at a second position identical to the first position and at a second time different from the first time; The first position and the second position are the same position.

2. The information processing device according to claim 1.

7. the moving body detects an object disposed in a space in which the moving body moves, The processing unit creates the first map in which the detected object is further mapped.

4. The information processing device according to claim 3.

8. 8. The information processing apparatus according to claim 7, wherein the object is detected based on the reflection of a laser beam emitted from the moving object.

9. An information processing device as described in claim 1, wherein the processing unit estimates that the signal propagation environment in the second space has changed when the second received power of the second signal received by the mobile body whose distance from the antenna is greater than or equal to a predetermined value is smaller than the first received power of the first signal received by the mobile body whose distance from the antenna is greater than or equal to the predetermined value.

10. An information processing device as described in claim 1, wherein some of the plurality of first data have a tendency for the first received power to increase as the distance between the mobile body and the antenna increases.

11. The first received power includes an average value of received powers of the first signal received at a plurality of frequencies, The second received power includes an average value of received power of the second signal received at a plurality of frequencies.

2. The information processing device according to claim 1.

12. An information processing device according to any one of claims 1 to 11; a mobile object communicably connected to the information processing device; A system comprising:

13. Acquiring a plurality of first data including a first position of a moving body moving between a first space in which a radio wave shield is placed and an antenna or a first distance between the moving body and the antenna when the moving body receives a first signal transmitted from the antenna, and a first reception power of the first signal; acquiring a plurality of second data including a second position of the moving body or a second distance between the moving body and the antenna when the moving body moving between the second space and the antenna receives a second signal different from the first signal transmitted from the antenna, and a second reception power of the second signal; When there is a difference between a trend of the first position or the first distance and the first reception power in the plurality of first data and a trend of the second position or the second distance and the second reception power in the plurality of second data, it is estimated that a propagation environment of the signal in the second space has changed. method.

14. On the computer, acquiring a plurality of first data including a first position of a moving body moving between a first space in which a radio wave shield is placed and an antenna when the moving body receives a first signal transmitted from the antenna or a first distance between the moving body and the antenna, and a first reception power of the first signal; acquiring a plurality of second data including a second position of a moving body moving between a second space and the antenna or a second distance between the moving body and the antenna when the moving body receives a second signal different from the first signal transmitted from the antenna, and a second reception power of the second signal; when there is a difference between a trend of the first position or the first distance and the first reception power in the plurality of first data and a trend of the second position or the second distance and the second reception power in the plurality of second data, it is estimated that a propagation environment of the signal in the second space has changed; A program to execute.

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