Position management server, wireless communication system, control circuit, storage medium, and mobile body position management method

Abstract

A position management server is a first position management server in a wireless communication system having the first position management server and a second position management server, the first position management server storing first position information indicating a position of a mobile body located by a first method, the second position management server storing second position information indicating a position of the mobile body located by a second method, the position management server having: a storage section (11) storing the first position information; a communication section (12) receiving the second position information from the second position management server, transmitting the first position information to the second position management server; and a control section (13) generating third position information indicating the position of the mobile body using the second position information and the first position information, storing in the storage section (11).

Description

Technical Field

[0001] This invention relates to a location management server for storing the location information of a mobile body, a wireless communication system, a control circuit, a storage medium, and a method for managing the location of a mobile body. Background Technology

[0002] In the past, in systems for locating mobile terminals, base stations or positioning servers exchange received power information and information about the angle of the received signal with the terminal via wireless communication, thereby determining the absolute position of the terminal expressed in latitude and longitude. As specified in the 3GPP (3rd Generation Partnership Project) standard, Non-Patent Document 1 discloses a technique for locating a terminal by exchanging reference signals between a base station or positioning server and the terminal.

[0003] Non-patent literature 1: "Physical layer procedures for data (Release 15)", 3GPP TS38.214, V 15.8.0, (2019-12) Summary of the Invention

[0004] However, the technology described in Non-Patent Document 1 has the following problem: if there are obstacles between the base station or positioning server and the terminal, the received power is reduced and accurate location information cannot be obtained. Although there is a way to perform relative positioning between the terminals and measure how far away the other terminal is, it is impossible to determine the absolute position of each terminal.

[0005] The present invention was proposed in view of the above-mentioned problems, and its purpose is to provide a location management server that can suppress the reduction of positioning accuracy when locating the position of a moving body.

[0006] To address the aforementioned issues and achieve the objective, the location management server of the present invention is a first location management server in a wireless communication system having a first location management server and a second location management server. The first location management server stores first location information indicating the location of a mobile object located via a first method, and the second location management server stores second location information indicating the location of a mobile object located via a second method. The location management server is characterized by comprising: a storage unit that stores the first location information; a communication unit that receives the second location information from the second location management server and transmits the first location information to the second location management server; and a control unit that uses the second location information and the first location information to generate third location information indicating the location of the mobile object and stores it in the storage unit.

[0007] The effects of the invention

[0008] The location management server of the present invention achieves the effect of suppressing the reduction of positioning accuracy when locating the position of a moving body. Attached Figure Description

[0009] Figure 1 Figure 1 shows a structural example of the wireless communication system according to Embodiment 1.

[0010] Figure 2 Figure 2 shows a structural example of the wireless communication system according to Embodiment 1.

[0011] Figure 3 This is a diagram illustrating an example of a reliable timestamp exchanged in a wireless communication system according to Implementation 1.

[0012] Figure 4 This is a diagram illustrating an example of location information timestamps exchanged in the wireless communication system according to Implementation 1.

[0013] Figure 5 This is a timing diagram showing the actions of a mobile body in obtaining reliability information in the wireless communication system according to Implementation Method 1.

[0014] Figure 6 This is a block diagram illustrating a structural example of a base station according to Implementation Method 1.

[0015] Figure 7 This is a block diagram illustrating a structural example of the mobile body according to Embodiment 1.

[0016] Figure 8 This is a first block diagram illustrating a structural example of the location management server involved in Implementation 1.

[0017] Figure 9 This is a flowchart illustrating the operation of the location management server involved in Implementation Method 1.

[0018] Figure 10 This is a block diagram illustrating a structural example of the control unit of the location management server according to Embodiment 1.

[0019] Figure 11 This is a diagram illustrating a configuration example of a sidelink station in a wireless communication system according to Embodiment 1.

[0020] Figure 12 This is the second block diagram illustrating a structural example of the location management server involved in Implementation 1.

[0021] Figure 13This is a timing diagram showing the operation of the location management server in the wireless communication system according to Embodiment 2 to locate the position of a mobile body.

[0022] Figure 14 Figure 1 shows the operational status of the location management server, base station, and mobile body in the wireless communication system according to Embodiment 2.

[0023] Figure 15 This is Figure 2, which shows the operational status of the location management server, base station, and mobile body in the wireless communication system according to Embodiment 2.

[0024] Figure 16 This is Figure 3, which shows the operational status of the location management server, base station, and mobile body in the wireless communication system according to Embodiment 2.

[0025] Figure 17 Figure 4 shows the operational status of the location management server, base station, and mobile body in the wireless communication system according to Embodiment 2.

[0026] Figure 18 This is a diagram illustrating an example of the structure of a processing circuit in which the processing circuit of the location management server described in embodiments 1 and 2 is implemented by a processor and a memory.

[0027] Figure 19 This is a diagram illustrating an example of a processing circuit in the case where the processing circuit of the location management server involved in embodiments 1 and 2 is constructed using dedicated hardware. Detailed Implementation

[0028] The location management server, wireless communication system, control circuit, storage medium, and mobile body location management method according to embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0029] Implementation Method 1

[0030] Figure 1 This is Figure 1, illustrating a structural example of the wireless communication system 100 according to Embodiment 1. The wireless communication system 100 includes location management servers 10 and 20, a base station 30, sidelink stations 40 and 50, and a mobile vehicle 60. The wireless communication system 100 is a system having a first location management server and a second location management server. The first location management server stores first location information indicating the location of the mobile vehicle 60 located by a first method, and the second location management server stores second location information indicating the location of the mobile vehicle 60 located by a second method. That is, the wireless communication system 100 has multiple location management servers that store location information of mobile vehicles 60 located by different methods.

[0031] In the wireless communication system 100, the location management server 10 can also be configured as the first location management server, with the first mode being a positioning mode that locates the absolute position of the mobile body 60, and the location information of the absolute position of the mobile body 60 stored by the location management server 10 being the first location information. Alternatively, the location management server 20 can be configured as the second location management server, with the second mode being a positioning mode that locates the relative position of the mobile body 60, and the location information of the relative position of the mobile body 60 stored by the location management server 20 being the second location information. The following explanation will be based on the case where location management server 10 is the first location management server and location management server 20 is the second location management server.

[0032] The base station 30 communicates with the location management server 10 and the mobile body 60. The base station 30, for example, uses a reference signal to determine the absolute position of the mobile body 60 based on the received power, the direction of the received electromagnetic waves, etc. The direction information of the received electromagnetic waves can also use the beam number used to receive the reference signal or the beam number used to transmit the reference signal. In the wireless communication system 100, multiple base stations 30 may be included, and positioning can be performed by transmitting the positioning reference signal from multiple base stations 30. Furthermore, in the wireless communication system 100, the mobile body 60 may also determine the absolute position of the base station 30 using the same method as described above and notify the base station 30 of its position information.

[0033] Side link stations 40 and 50 manage communication information between devices, i.e., side link communication information. For example, side link stations 40 and 50 generate control signals for inter-device communication and store the results of relative positioning between devices.

[0034] Mobile body 60 is a communication device that moves within the communication area of ​​wireless communication system 100. Mobile body 60 may be, for example, a vehicle equipped with a smartphone, mobile phone, communication terminal, or AGV (Automated Guided Vehicle), but is not limited to these. Mobile body 60 confirms its position with sidelink stations 40 and 50.

[0035] The location management server 10 locates the absolute position of the mobile body 60 through the base station 30, and manages and saves the first location information representing the absolute position of the located mobile body 60.

[0036] The location management server 20 locates the relative position of the mobile body 60 through the side link stations 40 and 50, and manages and saves the second location information representing the relative position of the located mobile body 60. Alternatively, the location management server 20 can also manage and save the absolute position of the mobile body 60 as the second location information, if it can calculate the absolute position of the mobile body 60 based on the location results obtained from locating the relative position of the mobile body 60 by multiple side link stations 40 and 50.

[0037] In the wireless communication system 100, communication from the mobile unit 60 to the base station 30 or the location management server 10, and communication from the mobile unit 60 to the side link stations 40, 50 or the location management server 20, are referred to as uplink. Similarly, in the wireless communication system 100, communication from the base station 30 or the location management server 10 to the mobile unit 60, and communication from the side link stations 40, 50 or the location management server 20 to the mobile unit 60, are referred to as downlink.

[0038] Furthermore, mobile units 60 can also confirm their locations with each other without using sidelink stations. Additionally, mobile units 60 can also exchange information directly with location management servers 10 and 20. Figure 2 Figure 2 shows a structural example of the wireless communication system 100 according to Embodiment 1. Figure 2 The diagram shows an example where position confirmation is also performed between moving bodies 60 and 70. Additionally, in... Figure 2 The diagram illustrates examples of mobile device 60 directly exchanging information with location management server 10, and mobile device 70 directly exchanging information with location management server 20. Figure 2 In the example, the location management server 10 locates the absolute positions of the moving bodies 60 and 70 to replace... Figure 1 The base station 30 shown. The positioning method for the absolute position of mobile bodies 60 and 70 in the location management server 10 is the same as that for base station 30. Figure 1 The method for locating the absolute positions of the mobile bodies 60 and 70 in the base station 30 shown is the same. Additionally, in Figure 2 In this example, the location management server 20 can also locate the relative positions of mobile bodies 60 and 70 instead of the side link station 40. The method for locating the relative positions of mobile bodies 60 and 70 in the location management server 20 is similar to... Figure 1 The positioning method for the relative positions of the moving bodies 60 and 70 in the side link stations 40 and 50 shown is the same. The following will use... Figure 1The wireless communication system 100 shown is used as an example for explanation. In addition, in this embodiment, an example via base station 30 is also conceivable, but in this case, base station 30 simply transmits reference signals according to the instructions issued from location management server 10, and transmits reference signals for positioning purposes.

[0039] This describes a method for determining the relative position of mobile body 60 between mobile body 60 and side link stations 40 and 50 in wireless communication system 100. As a method for determining the relative position of mobile body 60, positioning can be performed using reference signals specified by 3GPP standards, or using sensors installed on mobile body 60, side link stations 40 and 50. Regarding signals that can be used as reference signals in 3GPP standards, examples include DMRS (Demodulation Reference Signal) used in side links, but PRS (Positioning Reference Signal), CSI-RS (Channel State Information-Reference Signal), and TRS (Tracking Reference Signal) can also be used.

[0040] Typically, relative position information is exchanged between sidelink stations 40 and 50 and the mobile body 60. Sidelink stations 40 and 50, along with the mobile body 60, can transmit reference signals and determine the relative position of the communicating objects based on the reception status of the response signals to the reference signals. For example, sidelink station 40 can determine the direction and distance the mobile body 60 has moved from sidelink station 40, in meters or centimeters. Similarly, sidelink station 50 can determine the direction and distance the mobile body 60 has moved from sidelink station 50, in meters or centimeters. Sidelink stations 40 and 50 transmit the relative position information of the mobile body 60 to the location management server 20. Directional information can also use angle information, the beam number transmitted from sidelink station 40, the beam number transmitted from the mobile body 60, or the receiving beam number used in sidelink stations 40, the mobile body 60, etc.

[0041] If the side link stations 40 and 50 are fixedly positioned and their coordinates are known, the location management server 20 can use the relative position information of multiple side link stations 40 and 50 with the mobile body 60 to determine the position coordinates of the mobile body 60. Even without knowing the coordinates of the side link stations 40 and 50, the location management server 20 can manage the position information of the mobile body 60 using only its relative position. The location management server 20 can manage both the relative position information between the mobile body 60 and the side link stations 40 and 50, and the absolute position of the mobile body 60.

[0042] Sidelink stations 40 and 50 and location management server 20 exchange location information about mobile body 60. For example, sidelink station 40 sends the location information of mobile body 60 located through sidelink station 40 to location management server 20. Sidelink station 50 sends the location information of mobile body 60 located through sidelink station 50 to location management server 20. Location management server 20 sends the location information of mobile body 60 located through sidelink station 40 to sidelink station 50. Location management server 20 sends the location information of mobile body 60 located through sidelink station 50 to sidelink station 40. In this embodiment, sidelink stations 40 and 50 and location management server 20 exchange reliability timestamps and location information timestamps during the exchange of location information.

[0043] In addition, base station 30 and location management server 10 exchange location information about mobile body 60. For example, base station 30 sends the location information of mobile body 60 located by base station 30 to location management server 10. In this embodiment, base station 30 and location management server 10 exchange reliability timestamps and location information timestamps during the exchange of location information.

[0044] Figure 3 This is a diagram illustrating an example of reliable timestamps exchanged in the wireless communication system 100 according to Embodiment 1. Figure 3 In this diagram, the horizontal axis represents time, and the vertical axis represents reliability. Here, reliability represents the dependability of the location information. For example, if σ represents the standard error of the result obtained from locating the position of the moving object 60, reliability represents the probability that the relative distance falls within ±σ. σ can be measured in centimeters or meters. Alternatively, reliability can be expressed as the probability of exceeding a set error, also using σ. Furthermore, reliability can be represented by a 0 or 1 symbol, or by a quantized numerical value. The reliability timestamp represents the relationship between reliability and time. The unit of time can be seconds, minutes, hours, etc., or a system-specific time unit can be used.

[0045] Figure 4 This is a diagram illustrating an example of location information timestamps exchanged in the wireless communication system 100 according to Embodiment 1. (See diagram below.) Figure 4 As shown, the location information timestamp is data indicating the relationship between the latitude and longitude of the location of the mobile body 60 and the time of positioning. Alternatively, the location information timestamp can also be data indicating the relationship between the relative position of the mobile body 60 and the time of positioning.

[0046] The wireless communication system 100 can determine the location of the mobile body 60 and the relationship between the reliability of the mobile body 60's location and time by using data such as reliability timestamps and location information timestamps. Therefore, for example, in the event that the mobile body 60 is involved in an accident, the wireless communication system 100 can determine the time of the accident, the progression of the mobile body 60's movement, and the progression of reliability.

[0047] In addition, the reliability timestamp can also be included in supplementary information sent from location management servers 10 and 20, base station 30, sidelink stations 40 and 50, etc. Supplementary information may include, for example, assistance information as defined by 3GPP standards.

[0048] By periodically reporting location information from base station 30, location management server 10 can monitor the location of mobile body 60. Therefore, in situations where multiple mobile bodies 60 are present and an accident occurs due to their proximity, or where the reliability of location information reports decreases, location management server 10 can send instructions such as "stop moving" to the mobile body 60 to prevent accidents. Additionally, such as... Figure 1 As shown, the location management server 10 can also send movement instructions to the mobile body 60 and control the movement direction, speed, etc. of the mobile body 60.

[0049] Alternatively, the mobile body 60 may be able to request and obtain information about the reliability of its current location. Figure 5This is a timing diagram illustrating the operation of a mobile body 60 obtaining reliability information in the wireless communication system 100 according to Embodiment 1. The mobile body 60 requests reliability information at its location from the location management server 10 via the base station 30 (step S11). If the location management server 10 receives the reliability information request from the mobile body 60, it obtains the reliability information of the mobile body 60 (step S12). At this time, if the location management server 10 has not obtained the reliability information from the base station 30, it obtains the reliability information of the mobile body 60 that received the reliability information request from the base station 30; if it has already obtained the reliability information from the base station 30, it uses the obtained reliability information. The location management server 10 transmits the reliability information at the location of the mobile body 60 (step S13). Thus, the mobile body 60 can obtain reliability information at its current location, and even if the reliability is lower than a predetermined value, it can control actions such as stopping, moving direction, and speed without waiting for instructions from the location management server 10.

[0050] In this embodiment, the location management server 10 and the location management server 20 for the side link exchange the stored location information, namely, the reliability timestamp and the location information timestamp. Specifically, the location management server 10 sends first location information to the location management server 20. The first location information includes a reliability timestamp indicating the reliability of the location of the mobile body 60, which indicates the timing of the location determination using a first method, and a location information timestamp indicating the location of the mobile body 60. Furthermore, the location management server 20 sends second location information to the location management server 10. The second location information includes a reliability timestamp indicating the reliability of the location of the mobile body 60, which indicates the timing of the location determination using a second method, and a location information timestamp indicating the location of the mobile body 60.

[0051] Therefore, location management server 10 can obtain location information from location management server 20, and even if communication between base station 30 and mobile vehicle 60 is interrupted, it can still determine the location of mobile vehicle 60 by using the location information obtained from location management server 20. Similarly, location management server 20 can obtain location information from location management server 10, and even if communication between side link stations 40, 50 and mobile vehicle 60 is interrupted, it can still determine the location of mobile vehicle 60 by using the location information obtained from location management server 10. Furthermore, location management servers 10 and 20 can exchange either the reliability timestamp or the location information timestamp, or they can exchange information that does not contain time information between the reliability timestamp and the location information timestamp.

[0052] Next, the structure of each device will be explained. Figure 6This is a block diagram illustrating a structural example of the base station 30 according to Embodiment 1. The base station 30 includes a receiving unit 31, an information processing unit 32, a data signal control signal generation unit 33, a data signal generation unit 34, a reference signal control signal generation unit 35, a reference signal generation unit 36, and a transmission processing unit 37.

[0053] The receiving unit 31 receives signals transmitted from the mobile unit 60 or the location management server 10. The information processing unit 32, based on the output from the receiving unit 31 and the instructions (control signals) from the upper layer, issues instructions to the data signal control signal generation unit 33 and the reference signal control signal generation unit 35. The upper layer refers to the communication layer higher than the physical layer, such as the protocol layer or architecture level. In the 3GPP standard, information transmitted through positioning protocols such as RRC (Radio Resource Control) and LPP (LTE Positioning Protocol) is equivalent to instructions (control signals) from the upper layer. These instructions (control signals) from the upper layer can also be MAC-CE (Medium Access Control-Control Element) in the 3GPP standard.

[0054] The control signal generation unit 33 outputs a control signal to the data signal generation unit 34. The data signal generation unit 34 generates a data signal or control signal for transmission to the mobile body 60 or the location management server 10. Regarding the control signal, if the mobile body 60 receives the control signal, it is used as a control signal for data decryption. The control signal includes information such as data volume, modulation method, and multiplexing method. The control signal generation unit 35 outputs a control signal to the reference signal generation unit 36. The reference signal generation unit 36 ​​generates a reference signal for transmission to the mobile body 60 or the location management server 10. The reference signal includes signals used for positioning, data decryption, and transmission path estimation. The transmission processing unit 37 performs transmission processing such as conversion from digital signals to analog signals, digital filtering, and analog filtering on the data signal or control signal generated by the data signal generation unit 34 and the reference signal generated by the reference signal generation unit 36, and then transmits the signal.

[0055] In base station 30, information processing unit 32 may also have a storage function, such as a memory, for storing the positioning results of the absolute position of mobile body 60. Furthermore, the structures of side link stations 40 and 50 are the same as those of base station 30. In this case, the information processing units of side link stations 40 and 50 may also have a storage function, such as a memory, for storing the positioning results of the relative position of mobile body 60.

[0056] Figure 7This is a block diagram illustrating a structural example of the mobile body 60 according to Embodiment 1. The mobile body 60 includes a receiving unit 61, an information processing unit 62, a signal generation unit 63, and a transmission processing unit 64. The receiving unit 61 receives signals transmitted from base stations 30, side link stations 40, 50, etc. The receiving unit 61 can also receive reference signals transmitted from other mobile bodies. The received signals received by the receiving unit 61 include positioning reference signals, data demodulation control signals, data signals, etc. The information processing unit 62 issues instructions to the signal generation unit 63 based on the output from the receiving unit 61. The signal generation unit 63 generates data signals or control signals for transmission to base stations 30, side link stations 40, 50, and reference signals for transmission to other mobile bodies, etc. The transmission processing unit 64 performs transmission processing such as conversion from digital signals to analog signals, or digital filtering and analog filtering processing on the data signals, control signals, reference signals, etc. generated by the signal generation unit 63, and then transmits them. In the mobile body 60, the information processing unit 62 may also have a storage function, such as a memory, for storing the positioning results of the absolute or relative position of the mobile body 60.

[0057] Figure 8 This is a first block diagram illustrating a structural example of the location management server 10 according to Embodiment 1. The location management server 10 includes a storage unit 11, a communication unit 12, and a control unit 13. The storage unit 11 stores first location information indicating the absolute position of the mobile body 60, which is located by the base station 30.

[0058] The communication unit 12 communicates with the base station 30, the location management server 20, and the like. Specifically, the communication unit 12 receives second location information, which indicates the relative position of the mobile body 60 located by side link stations 40 and 50, from the location management server 20, and sends first location information to the location management server 20. Additionally, the communication unit 12 receives the first location information from the base station 30, which locates the position of the mobile body 60 using the first method, and stores it in the storage unit 11.

[0059] The control unit 13 uses the second position information and the first position information to generate third position information representing the position of the moving body 60 and stores it in the storage unit 11. For example, the control unit 13 compares the first position information and the second position information, obtains non-repeating information from the second position information and embeds it into the first position information to generate the third position information. Alternatively, the control unit 13 may compare the first position information and the second position information, obtain non-repeating information from the second position information and embed it into the first position information, and use highly reliable information for the repetitive parts to generate the third position information.

[0060] The operation of the location management server 10 is explained. Figure 9This is a flowchart illustrating the operation of the location management server 10 according to Embodiment 1. In the location management server 10, the communication unit 12 receives first location information (step S21) from the base station 30, which locates the position of the mobile body 60, and stores it in the storage unit 11. The storage unit 11 stores the first location information (step S22). The communication unit 12 receives second location information from the location management server 20 and sends the first location information to the location management server 20 (step S23). The control unit 13 uses the second location information and the first location information to generate third location information indicating the position of the mobile body 60 (step S24) and stores it in the storage unit 11.

[0061] In addition, the structure and operation of the location management server 10 have been described, but the structure and operation of the location management server 20 are the same as those of the location management server 10.

[0062] Here, when location management servers 10 and 20 exchange location information, namely reliability timestamps and location information timestamps, it is also conceivable that the location information stored by location management servers 10 and 20 may differ in format, time unit for positioning, and granularity of reliability. In such cases, location management servers 10 and 20 need to transform the location information obtained from the other side's location management server into a data format that their own location management server can use. Figure 10 This is a block diagram illustrating a structural example of the control unit 13 of the location management server 10 according to Embodiment 1. The control unit 13 includes an information conversion unit 131, a timing adjustment unit 132, and a reliability adjustment unit 133.

[0063] The information conversion unit 131 converts the format of the second location information to the format of the first location information. The information conversion unit 131 may also be a detachable structure relative to the location management server 10, serving as an information conversion device such as a PT (Positioning Translator). Alternatively, if the location management servers 10 and 20 manage the same format of location information, the location management server 10 may also be structured without the information conversion unit 131.

[0064] The timing adjustment unit 132 matches the timing used to locate the position of the moving body 60 via the first method with the timing used to locate the position of the moving body 60 via the second method. Specifically, when the timestamps of the first and second position information have different time units, the timing adjustment unit 132 unifies the time units of the timestamps of each position information. For example, if the position information in the first position information regarding a timing corresponding to a certain time when the moving body 60 is located is not included in the second position information, the timing adjustment unit 132 uses the position information included in the second position information, which was obtained by locating the position at a time corresponding to the timing before and after that timing, to interpolate and determine the position of the moving body 60 at the desired timing.

[0065] The reliability adjustment unit 133 matches the reliability in the first location information with the reliability in the second location information. Specifically, when the granularity of the reliability timestamps of the first and second location information is different, the reliability adjustment unit 133 unifies the granularity of the reliability of each location information. For example, the reliability adjustment unit 133 transforms the granularity of the reliability of the second location information to the granularity of the reliability of the first location information. The reliability used by the location management servers 10 and 20 can also be represented in the form of QoS (Quality of Service).

[0066] Alternatively, the information conversion unit 131 may also have the functions of a timing adjustment unit 132 and a reliability adjustment unit 133. Furthermore, in the aforementioned example, a mechanism for maintaining compatibility between parameters related to the first position information and parameters related to the second position information was described. However, adjustments can also be made using the same structure as the control unit 13 to maintain compatibility between parameters related to the second position information and parameters related to the first position information.

[0067] An application example of the wireless communication system 100 will be described. In the case of the wireless communication system 100, by exchanging and storing the location information of the mobile body 60 located in different ways through the location management servers 10 and 20, the possibility of losing the location of the mobile body 60 can be reduced. Therefore, the wireless communication system 100 can be applied to real-time control of the mobile body 60, etc. For example, the wireless communication system 100 can manage the movement of the mobile body 60 moving within the factory based on the relationship between time information represented by location information and reliability timestamps. The wireless communication system 100 can correct the operation timestamps of the equipment mounted on the mobile body 60 in accordance with the movement time of the mobile body 60. The equipment mounted on the mobile body 60 is, for example, a forklift loader. The wireless communication system 100 can manage the operation of the equipment in association with the timestamps.

[0068] Controlled by the wireless communication system 100, the following timing sequence is presented: For example, a mobile body 60 equipped with a forklift loader moves from location A at time T1 and arrives at location B at time T2. The mobile body 60 equipped with the forklift loader lifts the goods at location B at time T3 and moves towards location A at time T4. Time T1, T2, T3, and T4 can be absolute times or individual times used within the wireless communication system 100. Conventionally, equipment in a factory can operate according to time information from a schedule transmitted via a factory equipment operation management network such as a Time Sensitive Network (TSN). However, due to delays such as the time required for movement, the equipment mounted on the mobile body 60 may not be able to operate at the designated location according to the schedule. The wireless communication system 100 of this embodiment can suppress the decrease in positioning accuracy when locating the position of the mobile body 60, thus enabling continued control of the mobile body 60 without losing it. In addition, the location management server 10 can also adjust the timestamps of FA (Factory Automation) devices such as the mobile body 60 equipped with a fork loader through the information conversion unit 131 of the control unit 13.

[0069] The configuration of a sidelink station is explained when the wireless communication system 100 is used in a factory or other similar facility. Figure 11 This is a diagram illustrating a configuration example of a sidelink station in the wireless communication system 100 according to Embodiment 1. Figure 11 In this example, the wireless communication system 100 has side link stations 41-45. Side link stations 41-45 can be configured on the ground, or as... Figure 11 As shown, it is installed underground. Side link stations 41-45 are used to determine the relative position with the moving body 60. Therefore, as Figure 11 As shown in the ellipse, if the side link stations 41-45 are equally spaced underground, the wireless communication system 100 can determine the positions of the side link stations 41-45 and the mobile body 60 at fixed intervals, enabling accurate positioning of the mobile body 60. Furthermore, since the side link stations 41-45 are located underground, they do not become obstacles for the mobile body 60, making it a suitable configuration for positioning. Additionally, by installing the side link stations 41-45 underground, the layout of machines, conveyor belts, etc., within the factory is not affected, making it a suitable configuration for positioning the mobile body 60 within the factory as well.

[0070] Here, as Figure 2 As shown, the structure of the location management server 10 is described in the case where the mobile body 60 directly exchanges information with the location management server 10. Figure 12This is a second block diagram illustrating a structural example of the location management server 10 according to Embodiment 1. The location management server 10 includes a storage unit 11, a communication unit 12, a control unit 13, and a positioning unit 14. The positioning unit 14 locates the position of the moving body 60 using a first method, and stores first position information in the storage unit 11. The positioning unit 14 has... Figure 6 The base station 30 shown has the same structure, which enables the absolute position of the mobile body 60 to be located by the first method.

[0071] As described above, according to this embodiment, in the wireless communication system 100, location management servers 10 and 20 exchange and share location information of mobile bodies 60 located by different methods, which they store with each other. Therefore, even when there are obstacles between the base station 30 that locates the mobile body 60 and the mobile body 60, the location management server 10 can suppress the decrease in positioning accuracy when locating the mobile body 60 by using the location information from the location management server 20, and thus determine the location of the mobile body 60. Furthermore, even when there are obstacles between the location management server 20 and the side link stations 40 and 50 that locate the mobile body 60, the location management server 20 can suppress the decrease in positioning accuracy when locating the mobile body 60 by using the location information from the location management server 10, and thus determine the location of the mobile body 60.

[0072] In addition, by sharing location information, the location management servers 10 and 20 can determine the absolute position of the mobile body 60 and improve the positioning accuracy of the absolute position of the mobile body 60 by using the positioning results of the relative position between the mobile body 60 and the side link stations 40 and 50.

[0073] Implementation Method 2

[0074] In Embodiment 1, the wireless communication system 100 locates the position of the mobile body 60 using two methods. In Embodiment 2, a method for suppressing the decrease in positioning accuracy of the mobile body when it is impossible to locate the position of the mobile body using only one method will be described.

[0075] In embodiment 2, the wireless communication system 100 has Figure 13 and Figure 14 The mobile units 71 to 73 are shown. An example with three mobile units is used here, but this embodiment does not impose a limit on the number of mobile units. Furthermore, each mobile unit 71 to 73 has its own sensor and possesses positioning capabilities using relative positions obtained through standardized positioning methods such as IEEE (Institute of Electrical and Electronics Engineers) standards or 3GPP standards. Figure 13 This is a timing diagram illustrating the operation of the location management server 10 in the wireless communication system 100 according to Embodiment 2 to locate the positions of mobile bodies 71 to 73. Furthermore, either the location management server 10 or 20 may operate, but as an example, the operation of the location management server 10 will be described.

[0076] Figure 14 Figure 1 illustrates the operational states of the location management server 10, base station 30, and mobile units 71-73 in the wireless communication system 100 according to Embodiment 2. Mobile units 71-73 send a location request to the location management server 10 via the base station 30 (step S31). If the location management server 10 receives the location request, it requests a location capability report from the mobile units 71-73 via the base station 30 (step S32). Mobile units 71-73 report their location capability to the location management server 10 via the base station 30 (step S33). Location capability refers to the characteristics of the sensors, etc., possessed by the mobile units 71-73, and the location results relative to their positions with respect to the side link stations 40 and 50.

[0077] Figure 15 Figure 2 illustrates the operational states of the location management server 10, base station 30, and mobile units 71-73 in the wireless communication system 100 according to Embodiment 2. The location management server 10 designates a mobile unit with high relative positioning capability as a reference mobile unit (step S34). For example, the location management server 10 considers a mobile unit with a high-precision sensor as having high relative positioning capability and designates it as a reference mobile unit. Furthermore, the location management server 10 obtains positioning results relative to sidelink stations 40 and 50 from the location management server 20. Therefore, the location management server 10 may also compare the relative positioning results obtained from the location management server 20 with the relative positioning results of mobile units 71-73, and designate the mobile unit that sends a positioning result closest to the relative positioning result obtained from the location management server 20 as a mobile unit with high positioning capability. Alternatively, the location management server 10 may omit steps S31-S33 and pre-designate a mobile unit as a reference mobile unit. Here, the location management server 10 designates mobile unit 71 as the reference mobile unit. The location management server 10 notifies the mobile body 71 via the base station 30 that it has been designated as a reference mobile body (step S35), and notifies the absolute position of the mobile body 71 (step S36). Regarding the absolute position of the mobile body 71, as described in Embodiment 1, the base station 30 and the mobile body 71 can transmit and receive reference signals and determine the absolute position based on the observation results. Alternatively, the mobile body 71 can also use signals from satellites and supplementary information from the location management server 10 to determine its absolute position.

[0078] Figure 16 Figure 3 shows the operational states of the location management server 10, base station 30, and mobile units 71-73 in the wireless communication system 100 according to Embodiment 2. Mobile unit 71 receives the setting of the reference mobile unit and the notification of its absolute position from the location management server 10, and initializes the positioning for relative position (step S37). The initialization for relative position positioning refers to setting the absolute position, which becomes the reference when mobile unit 71 positions the relative position of mobile units 72 and 73. Mobile unit 71 notifies mobile unit 72 that the positioning for relative position has begun, and performs relative position positioning. Similarly, mobile unit 71 notifies mobile unit 73 that the positioning for relative position has begun, and performs relative position positioning (step S38). As for relative positioning, mobile unit 71 determines the distance and direction between the reference mobile unit, i.e., mobile unit 71, and mobile units 72 and 73. Regarding the direction, for mobile unit 71, it can be the direction in which the strongest received power is shown when receiving signals from mobile units 72 and 73. Mobile body 71 can also use the beam number of the reference signal transmitted for positioning, or the beam number used by mobile bodies 72 and 73 to receive the reference signal transmitted from mobile body 71, as directional information. The reference mobile body, i.e., mobile body 71, can accurately determine its relative position, thus enabling high-precision determination of the relative positions of mobile bodies 72 and 73 relative to mobile body 71. Mobile body 71 reports the positioning results of the relative positions of mobile bodies 72 and 73 to the location management server 10 via base station 30 (step S39). Alternatively, mobile bodies 72 and 73 can also report the positioning results of their relative positions to the location management server 10 via base station 30.

[0079] The location management server 10 has obtained the absolute position of the reference mobile body, i.e., mobile body 71. Therefore, if the positioning result of the relative position between mobile body 71 and mobile bodies 72 and 73 is obtained, the absolute positions of other mobile bodies 72 and 73 can be calculated (step S40). The location management server 10 notifies mobile body 72 of the calculated absolute position of mobile body 72 via base station 30, and notifies mobile body 73 of the calculated absolute position of mobile body 73 via base station 30 (step S41). Figure 17 Figure 4 shows the operating states of the location management server 10, base station 30, and mobile units 71-73 in the wireless communication system 100 according to Embodiment 2. Figure 17 The action state of step S41 is shown. Furthermore, in Figure 17 The description of the moving body 71 is omitted.

[0080] As described above, when multiple mobile bodies 71 to 73 are communicating wirelessly in the wireless communication system 100, if the control unit 13 receives a positioning request from the multiple mobile bodies 71 to 73, it sets mobile body 71 as the reference mobile body, i.e., the reference mobile body. The control unit 13 positions the reference mobile body 71 relative to the other mobile bodies 72 and 73, and notifies the reference mobile body 71 of its absolute position. The control unit 13 obtains the relative positions of the other mobile bodies 72 and 73 from the reference mobile body 71, and calculates the absolute positions of the other mobile bodies 72 and 73 using the absolute position of the reference mobile body 71 and the relative positions of the other mobile bodies 72 and 73.

[0081] As described above, according to this embodiment, the location management servers 10 and 20 can determine the location of other mobile bodies besides the reference mobile body by combining the accurate absolute location positioning result with the accurate relative location positioning result obtained from the reference mobile body. By setting the reference mobile body, the location management servers 10 and 20 can minimize the use of the resources, namely time and frequency band, required by the base station 30 to accurately locate the absolute position of the mobile body 60.

[0082] Next, the hardware structure of the location management server 10 will be described. In the location management server 10, the storage unit 11, communication unit 12, control unit 13, and positioning unit 14 are implemented by a processing circuit. The processing circuit can be a processor and memory that execute programs stored in memory, or it can be dedicated hardware. The processing circuit is also called the control circuit.

[0083] Figure 18 This is a diagram illustrating an example of the structure of the processing circuit 90 in the case where the processing circuit of the location management server 10 according to embodiments 1 and 2 is implemented by a processor and a memory. Figure 18 The processing circuit 90 shown is a control circuit, comprising a processor 91 and a memory 92. When the processing circuit 90 is composed of the processor 91 and the memory 92, each function of the processing circuit 90 is implemented by software, firmware, or a combination of both. The software or firmware is written as a program and stored in the memory 92. In the processing circuit 90, each function is implemented by reading and executing the program stored in the memory 92 from the processor 91. That is, the processing circuit 90 has a memory 92 for storing programs that, in effect, cause the location management server 10 to perform its processing. This program can also be described as a program used to cause the location management server 10 to perform the functions implemented by the processing circuit 90. This program can be provided by a storage medium storing the program or by other means such as a communication medium.

[0084] The above procedure can also be described as follows, which causes the location management server 10 to execute: Step 1, the storage unit 11 saves the first location information; Step 2, the communication unit 12 receives the second location information from the second location management server and sends the first location information to the second location management server; and Step 3, the control unit 13 uses the second location information and the first location information to generate third location information representing the position of the moving body 60 and saves it in the storage unit 11.

[0085] Here, the processor 91 is, for example, a CPU (Central Processing Unit), processing device, arithmetic device, microprocessor, microcomputer, or DSP (Digital Signal Processor). Additionally, the memory 92 is, for example, non-volatile or volatile semiconductor memory such as RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable ROM), EEPROM (Electrically EPROM), magnetic disk, floppy disk, optical disk, high-density disk, mini-disk, or DVD (Digital Versatile Disc).

[0086] Figure 19 This is a diagram illustrating an example of the processing circuit 93 in the case where the processing circuit of the location management server 10 according to embodiments 1 and 2 is constructed using dedicated hardware. Figure 19 The processing circuit 93 shown may be, for example, a single circuit, a composite circuit, a programmed processor, a parallelized programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination thereof. The processing circuit may also be partially implemented by dedicated hardware and partially by software or firmware. In this way, the processing circuit can implement the aforementioned functions through dedicated hardware, software, firmware, or a combination thereof.

[0087] The hardware structure of the location management server 10 has been described, but the hardware structures of the location management server 20, base station 30, side link stations 40 and 50, and mobile units 60 and 70-73 are also the same as those of the location management server 10.

[0088] The structure shown in the above embodiments is an example and can be combined with other known technologies. The embodiments can also be combined with each other, and a part of the structure can be omitted or changed without departing from the main idea.

[0089] Explanation of the label

[0090] 10, 20 Location management server, 11 Storage unit, 12 Communication unit, 13 Control unit, 14 Positioning unit, 30 Base station, 31, 61 Receiver unit, 32, 62 Information processing unit, 33 Control signal generation unit for data signals, 34 Data signal generation unit, 35 Control signal generation unit for reference signals, 36 Reference signal generation unit, 37, 64 Transmission processing unit, 40-45, 50 Side link station, 60, 70-73 Mobile unit, 63 Signal generation unit, 100 Wireless communication system, 131 Information conversion unit, 132 Timing adjustment unit, 133 Reliability adjustment unit.

Claims

1. A location management server, comprising a first location management server and a second location management server in a wireless communication system, wherein the first location management server manages and stores first location information indicating the location of a mobile body located by a first method, and the second location management server manages and stores second location information indicating the location of the mobile body located by a second method. Its characteristics are: The storage unit stores the first location information; The communication unit receives the second location information from the second location management server, sends the first location information to the second location management server, and in the second method, uses a side link in a manner that indicates the relative position of the mobile body using side link positioning based on the second location information; and The control unit uses the second position information and the first position information to generate third position information representing the position of the moving body, and stores it in the storage unit.

2. The location management server according to claim 1, characterized in that, The first location information includes a reliability timestamp indicating the reliability of the location of the moving body, which indicates the timing of the location determination using the first method, and a location information timestamp indicating the location of the moving body. The second location information includes a reliability timestamp indicating the reliability of the location of the moving body, which indicates the timing of the location determination by the second method, and a location information timestamp indicating the location of the moving body.

3. The location management server according to claim 2, characterized in that, The control unit has: A timing adjustment unit that matches the timing of positioning the moving body by the first method with the timing of positioning the moving body by the second method; as well as A reliability adjustment unit that matches the reliability in the first location information with the reliability in the second location information.

4. The location management server according to claim 3, characterized in that, The control unit has an information transformation unit that transforms the format of the second position information into the format of the first position information.

5. The location management server according to any one of claims 1 to 4, characterized in that, The communication unit receives the first location information from the base station that locates the position of the mobile body using the first method, and stores it in the storage unit.

6. The location management server according to any one of claims 1 to 4, characterized in that, It has a positioning unit that positions the moving body using the first method and stores the first position information in the storage unit.

7. The location management server according to any one of claims 1 to 4, characterized in that, The first method is for locating the absolute position of the moving body, and the second method is for locating the relative position of the moving body. In this wireless communication system, multiple moving bodies communicate wirelessly. If the control unit receives a positioning request from the plurality of mobile bodies, it selects a mobile body as a reference from the plurality of mobile bodies, that is, a reference mobile body, and indicates the positioning of the relative positions of other mobile bodies to the reference mobile body, and notifies the absolute position of the reference mobile body, obtains the relative positions of the other mobile bodies from the reference mobile body, and calculates the absolute positions of the other mobile bodies using the absolute position of the reference mobile body and the relative positions of the other mobile bodies.

8. A wireless communication system, characterized in that, have: The first location management server, which is the location management server according to any one of claims 1 to 7, manages and stores the first location information indicating the location of the mobile body located by the first method; and A second location management server manages and stores second location information representing the location of the mobile body located by a second method, wherein the second method uses a side link to indicate the relative position of the mobile body located using a side link, as shown by the second location information.

9. A control circuit for controlling a first location management server (i.e., a location management server) in a wireless communication system having a first location management server and a second location management server, the first location management server managing and storing first location information indicating the location of a mobile body located by a first method, and the second location management server managing and storing second location information indicating the location of the mobile body located by a second method. The characteristic of this control circuit is that, The location management server should perform the following processing: The first location information is saved. The second location information is received from the second location management server. In the second method, the first location information is sent to the second location management server using a side link, in a manner that the second location information indicates the relative position of the mobile body located using a side link. Using the second location information and the first location information, a third location information representing the position of the moving body is generated and saved.

10. A storage medium storing a program for controlling the first location management server (i.e., a location management server) in a wireless communication system having a first location management server and a second location management server, the first location management server managing and saving first location information indicating the location of a mobile body located by a first method, and the second location management server managing and saving second location information indicating the location of the mobile body located by a second method. The storage medium is characterized by, The program causes the location management server to perform the following processing: The first location information is saved. The second location information is received from the second location management server. In the second method, the first location information is sent to the second location management server using a side link, in a manner that the second location information indicates the relative position of the mobile body located using a side link. Using the second location information and the first location information, a third location information representing the position of the moving body is generated and saved.

11. A method for managing the location of a mobile entity, comprising a first location management server (i.e., a location management server) in a wireless communication system having a first location management server and a second location management server, wherein the first location management server manages and stores first location information representing the location of a mobile entity located via a first method, and the second location management server manages and stores second location information representing the location of the mobile entity located via a second method. The method for managing the location of a mobile entity is characterized by including: In the first step, the storage unit saves the first location information; In the second step, the communication unit receives the second location information from the second location management server. In the second method, the first location information is sent to the second location management server using a side link, in a manner that the second location information indicates the relative position of the mobile body located using a side link. In the third step, the control unit uses the second position information and the first position information to generate third position information representing the position of the moving body, and saves it in the storage unit.

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