Radio wave intensity correction system, arrival time notification system, mobile communication terminal device, communication terminal device, program, radio wave intensity correction method, and arrival time notification method

Abstract

In a technique for estimating the distance between two wireless communication terminals based on the radio wave strength between them, this invention provides a technique for correcting the measured radio wave strength. [Solution] The radio wave strength correction system includes a mobile communication terminal device 11 mounted on a mobile body, a communication terminal device 12 that communicates wirelessly with operating conditions, a wireless communication unit 125 that acquires the wireless radio wave strength between the mobile communication terminal device 11 and the communication terminal device 12, a history acquisition unit 152 that acquires history information 175 that associates the time when the radio wave strength was acquired by the wireless communication unit 125 with the radio wave strength, a strength prediction unit 153 that acquires predicted radio wave strength information 178 by predicting the radio wave strength to be acquired next time based on the history information 175, and a strength correction unit 154 that acquires corrected radio wave strength information 179 by correcting the radio wave strength included in the history information 175 according to the predicted radio wave strength information 178.

Description

Technical Field

[0001] The present invention relates to a technique for correcting a measured radio field strength in a technique for estimating a distance between two wireless communication terminal devices based on the radio field strength of wireless communication between the two wireless communication terminal devices.

Background Art

[0002] Conventionally, a technique is known that estimates the distance between terminals by using the radio field strength of wireless communication that attenuates according to the distance between the terminals.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, since the radio field strength is also affected by events other than the distance between the terminals, there is a problem that if the distance is estimated using the measured radio field strength as it is, the error in the estimated distance is large. For example, in the technique described in Patent Document 1, in an environment where multipath occurs, the radio field strength is greatly attenuated or, conversely, increased compared to the original distance between the terminals, which causes a problem that the estimated distance includes a larger error than the actual distance.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a technique for correcting measured radio field strength in a technique for estimating a distance between two wireless communication terminal devices based on the radio field strength of wireless communication between the two wireless communication terminal devices.

Means for Solving the Problems

[0006] To solve the above problems, the invention of claim 1 is a radio wave intensity correction system comprising: a mobile communication terminal device mounted on a mobile body; a communication terminal device that performs wireless communication with the mobile communication terminal; intensity acquisition means for acquiring the wireless radio wave intensity between the mobile communication terminal device and the communication terminal device; history acquisition means for acquiring history information relating the time at which the radio wave intensity was acquired by the intensity acquisition means and the radio wave intensity; intensity prediction means for acquiring a predicted radio wave intensity by predicting the radio wave intensity to be acquired next time based on the history information; and intensity correction means for acquiring a corrected radio wave intensity by correcting the radio wave intensity included in the history information according to the predicted radio wave intensity.

[0007] Furthermore, the invention of claim 2 is a radio wave intensity correction system according to the invention of claim 1, further comprising a route acquisition means for acquiring route information indicating the path of the moving object, wherein the intensity prediction means acquires the predicted radio wave intensity based on the route information.

[0008] Furthermore, the invention of claim 3 is a radio wave intensity correction system according to the invention of claim 2, wherein the route information includes starting position information indicating the position of the mobile body when the wireless communication between the communication terminal device and the mobile communication terminal device is started, and ending position information indicating the position of the mobile body when the wireless communication between the communication terminal device and the mobile communication terminal device is ended, the route acquisition means approximately determines the route of the mobile body based on the starting position information and the ending position information, and the intensity prediction means acquires the predicted radio wave intensity based on the approximately determined route.

[0009] Furthermore, the invention of claim 4 is a radio wave intensity correction system according to the invention of claim 1, further comprising a model acquisition means for acquiring model information showing the relationship between the distance between the communication terminal device and the mobile communication terminal device and the radio wave intensity of the wireless, wherein the intensity prediction means acquires the predicted radio wave intensity based on the model information.

[0010] Furthermore, the invention of claim 5 is a radio wave intensity correction system according to the invention of claim 4, wherein the model acquisition means acquires a plurality of model candidate information associated with environmental conditions, and determines the model information from the plurality of model candidate information according to the environmental conditions.

[0011] Furthermore, the invention of claim 6 is a radio wave intensity correction system according to the invention of claim 5, wherein the environmental conditions include at least one of the following: day of the week, time, weather, region, season, distinction between indoors and outdoors, type of mobile object, surrounding environment of the mobile object, and distinction between routes.

[0012] Furthermore, the invention of claim 7 is a radio wave intensity correction system according to the invention of claim 1, further comprising device identification means for identifying a target communication terminal device from the plurality of communication terminal devices by comparing the radio wave intensity of the wireless between the plurality of communication terminal devices and the mobile communication terminal device, wherein the intensity prediction means acquires the predicted radio wave intensity between the target communication terminal device and the mobile communication terminal device, and the intensity correction means acquires the corrected radio wave intensity between the target communication terminal device and the mobile communication terminal device.

[0013] Furthermore, the invention of claim 8 is a radio wave intensity correction system according to the invention of claim 1, further comprising a server device capable of data communication with the communication terminal device, wherein the intensity correction means is provided in the server device.

[0014] Furthermore, the invention of claim 9 is a radio wave intensity correction system according to any one of the inventions of claims 1 to 8, further comprising positioning means for determining the position of the moving object based on the corrected radio wave intensity.

[0015] Furthermore, the invention of claim 10 is a radio wave intensity correction system according to the invention of claim 9, wherein the position determination means determines the position using a particle filter.

[0016] Furthermore, the invention of claim 11 is a radio wave intensity correction system according to the invention of claim 10, wherein the radio wave intensity at time T and the amount of change in radio wave intensity at time (Ti) are defined as the likelihood of the particle filter.

[0017] Furthermore, the invention of claim 12 is a radio wave intensity correction system according to the invention of claim 10, wherein the positioning means moves particles that are distributed behind the position of the moving body predicted earlier than time (T+i) from a sample predicted at time (T+i).

[0018] Furthermore, the invention of claim 13 is a radio wave intensity correction system according to the invention of claim 10, comprising a storage means for storing a plurality of likelihood function candidate information, each associated with operating condition information, and an operating condition acquisition means for acquiring the operating condition information, wherein the position identification means identifies one likelihood function candidate information from the plurality of likelihood function candidate information according to the operating condition information acquired by the operating condition acquisition means, and calculates the weight of each particle using the identified likelihood function candidate information as likelihood function information.

[0019] Furthermore, the invention of claim 14 is a radio wave intensity correction system according to the invention of claim 13, wherein the operating condition information includes at least one of the following: day of the week, time, weather, region, season, distinction between indoors and outdoors, type of mobile object, surrounding environment of the mobile object, and distinction between route.

[0020] Furthermore, the invention of claim 15 is a radio wave intensity correction system according to the invention of claim 10, wherein the position identification means uses initial distribution information in which particles are biased towards the vicinity of the starting position of the moving body.

[0021] Furthermore, the invention of claim 16 is a radio wave intensity correction system according to the invention of claim 9, comprising a plurality of communication terminal devices, wherein the position of the mobile body is determined based on the position of the mobile body determined by the position determination means of one of the communication terminal devices and the position of the mobile body determined by the position determination means of another communication terminal device.

[0022] Furthermore, the invention of claim 17 is a mobile communication terminal device mounted on a mobile body that performs wireless communication with a communication terminal device installed outside the mobile body, and comprises: an intensity acquisition means for acquiring the radio wave intensity of the wireless communication with the communication terminal device; a history acquisition means for acquiring history information relating the time at which the radio wave intensity was acquired by the intensity acquisition means and the radio wave intensity; an intensity prediction means for acquiring a predicted radio wave intensity by predicting the radio wave intensity to be acquired next time based on the history information; and an intensity correction means for acquiring a corrected radio wave intensity by correcting the radio wave intensity included in the history information according to the predicted radio wave intensity.

[0023] Furthermore, the invention of claim 18 is a communication terminal device that performs wireless communication with a mobile communication terminal device mounted on a mobile body, comprising: an intensity acquisition means for acquiring the radio wave intensity of the wireless communication with the mobile communication terminal device; a history acquisition means for acquiring history information relating the time at which the radio wave intensity was acquired by the intensity acquisition means and the radio wave intensity; an intensity prediction means for acquiring a predicted radio wave intensity by predicting the radio wave intensity to be acquired next time based on the history information; and an intensity correction means for acquiring a corrected radio wave intensity by correcting the radio wave intensity included in the history information according to the predicted radio wave intensity.

[0024] Furthermore, the invention of claim 19 is a computer-readable program for correcting the radio wave intensity using a mobile communication terminal device mounted on a mobile body and a communication terminal device that communicates wirelessly with the mobile communication terminal, wherein the execution of the program by the computer causes the computer to function as a computer comprising: intensity acquisition means for acquiring the radio wave intensity between the mobile communication terminal device and the communication terminal device; history acquisition means for acquiring history information relating the time at which the radio wave intensity was acquired by the intensity acquisition means and the radio wave intensity; intensity prediction means for acquiring predicted radio wave intensity by predicting the radio wave intensity to be acquired next time based on the history information; and intensity correction means for acquiring corrected radio wave intensity by correcting the radio wave intensity included in the history information according to the predicted radio wave intensity.

[0025] Further, the invention of claim 20 is a radio field intensity correction method for correcting the radio field intensity of wireless communication using a mobile communication terminal device mounted on a mobile object and a communication terminal device that performs wireless communication with the mobile communication terminal, the method comprising: a step of acquiring the radio field intensity of the wireless communication between the mobile communication terminal device and the communication terminal device by an intensity acquisition unit; a step of acquiring history information in which the time at which the radio field intensity was acquired by the intensity acquisition unit is associated with the relevant radio field intensity by a history acquisition unit; a step of acquiring a predicted radio field intensity by an intensity prediction unit by predicting the radio field intensity to be acquired next time based on the history information; and a step of acquiring a corrected radio field intensity by an intensity correction unit by correcting the radio field intensity included in the history information in accordance with the predicted radio field intensity.

[0026] Further, the invention of claim 21 is an arrival time notification system for notifying a predicted arrival time indicating the time at which a mobile object moving on a movement route is predicted to arrive at a destination, the system comprising: a mobile communication terminal device mounted on the mobile object; a communication terminal device installed in the vicinity of the destination and configured to perform wireless communication with the mobile communication terminal device; a terminal position acquisition unit configured to acquire terminal position information indicating the position of the communication terminal device; a movement route acquisition unit configured to acquire movement route information indicating the movement route; an intensity acquisition unit configured to acquire the radio field intensity of the wireless communication between the communication terminal device and the mobile communication terminal device; a position specifying unit configured to specify the position of the mobile object based on the radio field intensity acquired by the intensity acquisition unit and the movement route information; a time prediction unit configured to obtain the predicted arrival time based on the position of the mobile object specified by the position specifying unit, the movement route information, and the terminal position information; and an output unit configured to notify by outputting the predicted arrival time predicted by the time prediction unit.

[0027] Further, the invention of claim 22 is the arrival time notification system according to claim 21, wherein the wireless communication is power-saving long-range communication.

[0028] Furthermore, the invention of claim 23 is an arrival time notification system according to the invention of claim 21, wherein the mobile body is a bus that carries passengers, and the communication terminal device is installed at the bus stop.

[0029] Furthermore, the invention of claim 24 is an arrival time notification system according to the invention of claim 21, wherein the communication terminal device is installed on a utility pole provided along the travel route.

[0030] Furthermore, the invention of claim 25 is an arrival time notification system according to any one of the inventions of claims 21 to 24, further comprising: a history acquisition means for acquiring history information relating the time at which the radio wave intensity was acquired by the intensity acquisition means and the radio wave intensity; an intensity prediction means for acquiring a predicted radio wave intensity by predicting the radio wave intensity to be acquired next based on the history information; and an intensity correction means for acquiring a corrected radio wave intensity by correcting the radio wave intensity included in the history information according to the predicted radio wave intensity, wherein the position identification means identifies the position of the moving object based on the corrected radio wave intensity acquired by the intensity correction means instead of the radio wave intensity acquired by the intensity acquisition means.

[0031] Furthermore, the invention of claim 26 is a mobile communication terminal device mounted on a mobile body moving along a travel path, comprising: wireless communication means for wirelessly communicating with a communication terminal device installed near the destination of the mobile body; terminal location acquisition means for acquiring terminal location information indicating the location of the communication terminal device; travel path acquisition means for acquiring travel path information indicating the travel path; intensity acquisition means for acquiring the radio wave intensity of the wireless signal between the communication terminal device and the mobile communication terminal device; location identification means for identifying the location of the mobile body based on the radio wave intensity acquired by the intensity acquisition means and the travel path information; time prediction means for determining the predicted arrival time based on the location of the mobile body identified by the location identification means, the travel path information and the terminal location information; and the wireless communication means outputs the predicted arrival time determined by the time prediction means to the communication terminal device.

[0032] Furthermore, the invention of claim 27 is a communication terminal device installed near the destination of a mobile body moving along a travel path, comprising: wireless communication means for wirelessly communicating with a mobile communication terminal device mounted on the mobile body; terminal location acquisition means for acquiring terminal location information indicating the location of the communication terminal device; travel path acquisition means for acquiring travel path information indicating the travel path; intensity acquisition means for acquiring the radio wave intensity of the wireless signal between the communication terminal device and the mobile communication terminal device; location identification means for identifying the location of the mobile body based on the radio wave intensity acquired by the intensity acquisition means and the travel path information; time prediction means for determining the predicted arrival time based on the location of the mobile body identified by the location identification means, the travel path information and the terminal location information; and output means for notifying by outputting the predicted arrival time determined by the time prediction means.

[0033] Furthermore, the invention of claim 28 is a computer-readable program for notifying a predicted arrival time, which indicates the time it is predicted that a mobile body moving along a travel path will arrive at a destination, wherein the execution of the program by the computer causes the computer to function as a computer comprising: a mobile communication terminal device mounted on the mobile body; a wireless communication means for communicating with a communication terminal device installed near the destination and communicating wirelessly with the mobile communication terminal device; a terminal location acquisition means for acquiring terminal location information indicating the location of the communication terminal device; a travel path acquisition means for acquiring travel path information indicating the travel path; an intensity acquisition means for acquiring the radio wave intensity of the wireless signal between the communication terminal device and the mobile communication terminal device; a location identification means for identifying the location of the mobile body based on the radio wave intensity acquired by the intensity acquisition means and the travel path information; a time prediction means for determining the predicted arrival time based on the location of the mobile body identified by the location identification means, the travel path information, and the terminal location information; and an output means for notifying by outputting the predicted arrival time determined by the time prediction means.

[0034] Furthermore, the invention of claim 29 is an arrival time notification method for notifying a predicted arrival time, which indicates the time when a mobile body is expected to arrive at its destination, using a mobile communication terminal device mounted on a mobile body moving along a travel path and a communication terminal device installed near the destination of the mobile body and communicating wirelessly with the mobile communication terminal device, comprising the steps of: acquiring terminal location information indicating the location of the communication terminal device; acquiring travel path information indicating the travel path; acquiring the radio wave strength of the wireless signal between the communication terminal device and the mobile communication terminal device; identifying the location of the mobile body based on the acquired radio wave strength and the travel path information; determining the predicted arrival time based on the identified location of the mobile body, the travel path information and the terminal location information; and notifying by outputting the determined predicted arrival time. [Effects of the Invention]

[0035] The inventions described in claims 1 to 16 are radio wave intensity correction systems comprising: a mobile communication terminal device mounted on a mobile body; a communication terminal device that performs wireless communication with the mobile communication terminal; intensity acquisition means for acquiring the wireless radio wave intensity between the mobile communication terminal device and the communication terminal device; history acquisition means for acquiring history information relating the time at which the radio wave intensity was acquired by the intensity acquisition means and the radio wave intensity; intensity prediction means for acquiring predicted radio wave intensity by predicting the radio wave intensity to be acquired next based on the history information; and intensity correction means for acquiring corrected radio wave intensity by correcting the radio wave intensity included in the history information according to the predicted radio wave intensity. By doing so, it is possible to suppress the influence of events other than the distance between the mobile communication terminal device and the communication terminal device on the radio wave intensity by correcting it according to the purpose.

[0036] Furthermore, the invention described in claim 17 is a mobile communication terminal device mounted on a mobile body that performs wireless communication with a communication terminal device installed outside the mobile body, and comprises: an intensity acquisition means for acquiring the wireless radio wave strength between the mobile communication terminal device and the communication terminal device; a history acquisition means for acquiring history information relating the time at which the radio wave strength was acquired by the intensity acquisition means and the radio wave strength; an intensity prediction means for acquiring a predicted radio wave strength by predicting the radio wave strength to be acquired next based on the history information; and an intensity correction means for acquiring a corrected radio wave strength by correcting the radio wave strength included in the history information according to the predicted radio wave strength. As a result, by correcting according to the purpose, it is possible to suppress the influence of events other than the distance between the mobile communication terminal device and the communication terminal device on the radio wave strength.

[0037] Furthermore, the invention described in claim 18 is a communication terminal device that performs wireless communication with a mobile communication terminal device mounted on a mobile body, comprising: an intensity acquisition means for acquiring the wireless radio wave strength between the mobile communication terminal device and the communication terminal device; a history acquisition means for acquiring history information relating the time at which the radio wave strength was acquired by the intensity acquisition means and the radio wave strength; an intensity prediction means for acquiring a predicted radio wave strength by predicting the radio wave strength to be acquired next based on the history information; and an intensity correction means for acquiring a corrected radio wave strength by correcting the radio wave strength included in the history information according to the predicted radio wave strength. By correcting according to the purpose, for example, the influence of events other than the distance between the mobile communication terminal device and the communication terminal device on the radio wave strength can be suppressed.

[0038] Furthermore, the invention described in claim 19 is a computer-readable program for correcting radio wave intensity using a mobile communication terminal device mounted on a mobile body and a communication terminal device that communicates wirelessly with the mobile communication terminal, wherein the execution of the program by the computer causes the computer to function as a computer comprising: intensity acquisition means for acquiring radio wave intensity between the mobile communication terminal device and the communication terminal device; history acquisition means for acquiring history information relating the time at which the radio wave intensity was acquired by the intensity acquisition means and said radio wave intensity; intensity prediction means for acquiring predicted radio wave intensity by predicting the radio wave intensity to be acquired next time based on the history information; and intensity correction means for acquiring corrected radio wave intensity by correcting the radio wave intensity included in the history information according to the predicted radio wave intensity. As a result, by correcting according to the purpose, the influence of events other than the distance between the mobile communication terminal device and the communication terminal device on the radio wave intensity can be suppressed, for example.

[0039] Furthermore, the invention described in claim 20 is a radio wave intensity correction method for correcting radio wave intensity using a mobile communication terminal device mounted on a mobile body and a communication terminal device that performs wireless communication with the mobile communication terminal, comprising the steps of: acquiring the radio wave intensity between the mobile communication terminal device and the communication terminal device using intensity acquisition means; acquiring history information by history acquisition means that associates the time at which the radio wave intensity was acquired by the intensity acquisition means with the radio wave intensity; acquiring a predicted radio wave intensity by intensity prediction means by predicting the radio wave intensity to be acquired next based on the history information; and acquiring a corrected radio wave intensity by intensity correction means by correcting the radio wave intensity included in the history information according to the predicted radio wave intensity. By doing so, by correcting according to the purpose, for example, the influence of events other than the distance between the mobile communication terminal device and the communication terminal device on the radio wave intensity can be suppressed.

[0040] Furthermore, the invention described in claim 21 is an arrival time notification system that notifies a predicted arrival time indicating the time when a mobile body moving along a travel path is expected to arrive at a destination, comprising: a mobile communication terminal device mounted on the mobile body; a communication terminal device installed near the destination and performing wireless communication with the mobile communication terminal device; a terminal location acquisition means for acquiring terminal location information indicating the location of the communication terminal device; a travel path acquisition means for acquiring travel path information indicating the travel path; a strength acquisition means for acquiring the radio wave strength of the radio waves between the communication terminal device and the mobile communication terminal device; a location identification means for identifying the location of the mobile body based on the radio wave strength acquired by the strength acquisition means and the travel path information; a time prediction means for determining the predicted arrival time based on the location of the mobile body identified by the location identification means, the travel path information, and the terminal location information; and an output means for notifying by outputting the predicted arrival time predicted by the time prediction means. This makes it possible to notify the predicted arrival time without using GPS.

[0041] Furthermore, the invention described in claim 26 is a mobile communication terminal device mounted on a mobile body moving along a travel path, comprising: wireless communication means for wirelessly communicating with a communication terminal device installed near the destination of the mobile body; terminal location acquisition means for acquiring terminal location information indicating the location of the communication terminal device; travel path acquisition means for acquiring travel path information indicating the travel path; intensity acquisition means for acquiring the radio wave intensity between the communication terminal device and the mobile communication terminal device; location identification means for identifying the location of the mobile body based on the radio wave intensity acquired by the intensity acquisition means and the travel path information; time prediction means for determining the predicted arrival time based on the location of the mobile body identified by the location identification means, the travel path information and the terminal location information; and the wireless communication means outputs the predicted arrival time determined by the time prediction means to the communication terminal device. This makes it possible to notify the predicted arrival time without using GPS.

[0042] Furthermore, the invention described in claim 27 is a communication terminal device installed near the destination of a mobile body moving along a travel path, comprising: wireless communication means for wirelessly communicating with a mobile communication terminal device mounted on the mobile body; terminal location acquisition means for acquiring terminal location information indicating the location of the communication terminal device; travel path acquisition means for acquiring travel path information indicating the travel path; intensity acquisition means for acquiring the radio wave intensity between the communication terminal device and the mobile communication terminal device; location identification means for identifying the location of the mobile body based on the radio wave intensity acquired by the intensity acquisition means and the travel path information; time prediction means for determining the predicted arrival time based on the location of the mobile body identified by the location identification means, the travel path information and the terminal location information; and output means for notifying by outputting the predicted arrival time determined by the time prediction means. This makes it possible to notify the predicted arrival time without using GPS.

[0043] Furthermore, the invention described in claim 28 is a computer-readable program for notifying a predicted arrival time, which indicates the time it is predicted that a mobile body moving along a travel path will arrive at a destination. The execution of this program by a computer causes the computer to function as a computer comprising: a mobile communication terminal device mounted on the mobile body; wireless communication means for communicating with a communication terminal device installed near the destination and communicating wirelessly with the mobile communication terminal device; terminal location acquisition means for acquiring terminal location information indicating the location of the communication terminal device; travel path acquisition means for acquiring travel path information indicating the travel path; intensity acquisition means for acquiring the radio wave intensity between the communication terminal device and the mobile communication terminal device; location identification means for identifying the position of the mobile body based on the radio wave intensity acquired by the intensity acquisition means and the travel path information; time prediction means for determining the predicted arrival time based on the position of the mobile body identified by the location identification means, the travel path information, and the terminal location information; and output means for notifying by outputting the predicted arrival time determined by the time prediction means. This makes it possible to notify the predicted arrival time without using GPS.

[0044] Furthermore, the invention described in claim 29 is an arrival time notification method for notifying a predicted arrival time, which indicates the time when a mobile body is expected to arrive at its destination, using a mobile communication terminal device mounted on a mobile body moving along a travel path and a communication terminal device installed near the destination of the mobile body and communicating wirelessly with the mobile communication terminal device, comprising the steps of: acquiring terminal location information indicating the location of the communication terminal device; acquiring travel path information indicating the travel path; acquiring the radio wave strength between the communication terminal device and the mobile communication terminal device; identifying the location of the mobile body based on the acquired radio wave strength and travel path information; determining the predicted arrival time based on the identified location of the mobile body, travel path information and terminal location information; and notifying by outputting the determined predicted arrival time. This makes it possible to notify the predicted arrival time without using GPS. [Brief explanation of the drawing]

[0045] [Figure 1] This is a diagram showing the configuration of the radio wave intensity correction system in the first embodiment. [Figure 2] This is a block diagram for mobile communication terminal equipment. [Figure 3] This is a block diagram of a communication terminal device according to the first embodiment. [Figure 4] This diagram shows the functional blocks of the communication terminal device in the first embodiment, along with the data flow. [Figure 5] This is a flowchart illustrating the radio wave correction method in the first embodiment. [Figure 6] This is a flowchart illustrating the radio wave intensity correction process in the first embodiment. [Figure 7] This is a flowchart illustrating the radio wave intensity prediction process in the first embodiment. [Figure 8] This is a diagram showing the configuration of the radio wave intensity correction system in the second embodiment. [Figure 9] This is a block diagram of a communication terminal device in the second embodiment. [Figure 10]This diagram shows the functional blocks of the communication terminal device in the second embodiment, along with the data flow. [Figure 11] This is a block diagram showing the server device in the second embodiment. [Figure 12] This diagram shows the functional blocks of the server device in the second embodiment, along with the data flow. [Figure 13] This figure shows the structure of the model database in the second embodiment. [Figure 14] This is a flowchart illustrating the radio wave intensity correction method in the second embodiment. [Figure 15] This is a flowchart illustrating the radio wave intensity correction method in the second embodiment. [Figure 16] This is a flowchart illustrating the operation of the server device in the second embodiment. [Figure 17] This figure illustrates the positional relationship between the mobile body and the communication terminal device in the second embodiment. [Figure 18] Figure 17 shows the relationship between the terminal distance and the route exemplified therein. [Figure 19] This is a flowchart illustrating the operation of the server device in the second embodiment. [Figure 20] This is a flowchart illustrating the radio wave intensity correction process in the second embodiment. [Figure 21] This is a flowchart illustrating the radio wave intensity prediction process in the second embodiment. [Figure 22] This figure shows the radio wave intensity correction system in the third embodiment. [Figure 23] This is a block diagram showing a communication terminal device in the third embodiment. [Figure 24] This figure shows the structure of the function database in the third embodiment. [Figure 25] This diagram shows the functional blocks of the communication terminal device in the third embodiment, along with the data flow. [Figure 26] This is a flowchart illustrating the operation of the communication terminal device in the third embodiment. [Figure 27] This diagram illustrates the typical particle distribution in an initial state. [Figure 28] This figure illustrates the particle distribution in the initial state according to the third embodiment. [Figure 29] This is a flowchart illustrating the radio wave intensity correction method in the third embodiment. [Figure 30] This is a flowchart illustrating the radio wave intensity prediction process in the third embodiment. [Figure 31] This is a flowchart illustrating the particle filter processing in the third embodiment. [Figure 32] This figure illustrates the distribution of the predicted samples in the third embodiment. [Figure 33] Figure 32 shows the size of each particle, with the weight values ​​reflected in the resulting diagram. [Figure 34] Figure 33 shows an example of particle resampling. [Figure 35] This is a diagram illustrating the configuration of the arrival time notification system. [Figure 36] This is a block diagram of a wireless in-vehicle device. [Figure 37] This is a block diagram of a notification device. [Figure 38] This diagram shows the functional blocks of the notification device along with the data flow. [Figure 39] This is a block diagram of a measuring device. [Figure 40] This diagram shows the functional blocks of the measuring device along with the data flow. [Figure 41] This is a block diagram showing a server device in the fourth embodiment. [Figure 42] This diagram illustrates the information included in the configuration settings. [Figure 43] This diagram shows the functional blocks of the server device in the fourth embodiment, along with the data flow. [Figure 44] This is a flowchart illustrating the operation of the notification device in the arrival time notification method. [Figure 45]This is a flowchart illustrating the operation of the observation device in the arrival time notification method. [Figure 46] This diagram shows the operation of the server device in the arrival time notification method. [Figure 47] This diagram shows the operation of the server device in the arrival time notification method. [Figure 48] This is a flowchart illustrating the radio wave intensity correction process in the fourth embodiment. [Figure 49] This is a flowchart illustrating the radio wave intensity prediction process in the fourth embodiment. [Figure 50] This is a flowchart illustrating the particle filter processing in the fourth embodiment. [Modes for carrying out the invention]

[0046] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, unless otherwise specified in the following description, descriptions of directions and orientations correspond to the drawings for the convenience of the description and do not limit, for example, the implemented product, the product, or the scope of rights.

[0047] Furthermore, the functions of the elements disclosed herein may be implemented using circuit configurations or processing circuit configurations, including general-purpose processors, dedicated processors, integrated circuits, ASICs (application-specific integrated circuits), conventional circuit configurations, and / or combinations thereof, which are configured to perform the disclosed elements or programmed to perform the disclosed functions. A processor is considered a processing circuit configuration or circuit configuration if it includes transistors and other circuit configurations within it. In this disclosure, a circuit configuration, unit, or means is hardware that performs the listed functions or hardware programmed to realize such functions. Hardware may be any hardware disclosed herein or other known hardware programmed to perform the listed functions or configured to perform such functions. When hardware is a processor which may be considered a type of circuit configuration, a circuit configuration, means, or unit is a combination of hardware and software, software used to configure the hardware, and / or a processor.

[0048] <1. First Embodiment> Figure 1 is a diagram showing the configuration of the radio wave intensity correction system 10 in the first embodiment. The radio wave intensity correction system 10 comprises a mobile communication terminal device 11 mounted on a mobile body and a communication terminal device 12 that communicates wirelessly with the mobile communication terminal device 11.

[0049] Furthermore, the wireless communication between the mobile communication terminal device 11 and the communication terminal device 12 is a low-power, long-distance wireless communication, and in particular, in the first embodiment, Wi-Fi HaLow, which is a low-power, long-distance communication, will be used as an example.In addition, although a vehicle is used as an example to illustrate the mobile object in Figure 1, the mobile object may be a ship, aircraft, drone, robot, transporter used in a factory, or a train, etc.

[0050] Furthermore, in the following explanation, time will be referred to as "time T," and the position of the moving object will be referred to as "position PO." The position PO at time T may also be expressed using T as a subscript, such as position PO(T).

[0051] Furthermore, the straight-line distance between the mobile device (mobile communication terminal device 11) and the communication terminal device 12 is referred to as "terminal distance CD," and the total distance traveled from the starting point of the mobile device to its current position is referred to as "cumulative travel distance CMD."

[0052] Figure 2 is a block diagram showing the mobile communication terminal device 11. As already explained, the mobile communication terminal device 11 is mounted on a mobile body and its position changes as the mobile body moves.

[0053] For the sake of simplicity, the moving body in the first embodiment is assumed to start from the starting position shown in Figure 1 and move linearly away from the communication terminal device 12 (moving in one dimension and without reversing direction; however, it may stop at an intermediate point).

[0054] The mobile communication terminal device 11 includes a CPU 110, a storage device 111, an operation unit 112, a display unit 113, and a wireless communication unit 115.

[0055] The acquired information 170 is a general term for the information acquired by the mobile communication terminal device 11. The acquired information 170 includes information obtained from external devices via the wireless communication unit 115 and information input by operating the operation unit 112. The acquired information 170 may also include pre-stored information, such as setting information.

[0056] Furthermore, output information 171 is a general term for information transmitted to an external device via the wireless communication unit 115, and information output by being displayed on the display unit 113. If the mobile communication terminal device 11 is equipped with a speaker, output information 171 may also be related to voice information.

[0057] The CPU 110 reads and executes the program 811 stored in the memory device 111, performing calculations on various data and generating control signals. Thus, the CPU 110 controls the various components of the mobile communication terminal device 11 and has the function of calculating and creating various data. In other words, the mobile communication terminal device 11 is configured as a general-purpose computer.

[0058] The storage device 111 provides a function for storing various types of data in the mobile communication terminal device 11. In other words, the storage device 111 stores electronically fixed information in the mobile communication terminal device 11.

[0059] The storage device 111 can include RAM or buffers used as a temporary working area for the CPU 110, read-only ROM, non-volatile memory (such as NAND memory), hard disks for storing relatively large amounts of data, and portable storage media mounted on dedicated reading devices (such as CD-ROMs, DVD-ROMs, PC cards, SD cards, and USB memory). In Figure 2, the storage device 111 is illustrated as if it were a single structure. However, typically, the storage device 111 is composed of multiple types of devices (or media) as exemplified above, selected as needed. In other words, the storage device 111 is a general term for a group of devices that have the function of storing data.

[0060] Furthermore, the actual CPU 110 is an electronic circuit that has high-speed access RAM built into it. However, for the sake of explanation, the memory device of such a CPU 110 will also be included in the memory device 111. In other words, data that the CPU 110 itself temporarily stores will also be explained as being stored by the memory device 111. As shown in Figure 2, the memory device 111 is used to store the program 811, acquired information 170, output information 171, etc.

[0061] The operation unit 112 is hardware that an operator or other person operates to input instructions to the mobile communication terminal device 11. The information input in this way is stored in the storage device 111 as acquired information 170. Examples of the operation unit 112 include various keys and buttons, switches, touch panels, pointing devices, or jog dials.

[0062] The display unit 113 is hardware that has the function of outputting various data (for example, output information 171) to operators, etc. Examples of the display unit 113 include lamps, LEDs, CRTs, liquid crystal displays, and liquid crystal panels.

[0063] The wireless communication unit 115 provides the function for the mobile communication terminal device 11 to communicate wirelessly with an external device (communication terminal device 12). As a result, in the first embodiment, the mobile communication terminal device 11 performs wireless communication with the communication terminal device 12 in accordance with the Wi-Fi HaLow standard.

[0064] Information received by the wireless communication unit 115 is transmitted to the CPU 110 and stored in the storage device 111 as acquired information 170. Information to be transmitted by the wireless communication unit 115 (for example, output information 171) is transmitted from the CPU 110.

[0065] The configuration of the mobile communication terminal device 11 is not limited to the configuration shown in Figure 2. For example, the mobile communication terminal device 11 may include a sensor that takes observed information as acquired information 170, a timer for measuring time, a speaker that outputs information related to voice, and so on.

[0066] Figure 3 is a block diagram showing the communication terminal device 12 in the first embodiment. In the first embodiment, the communication terminal device 12 is positioned in the immediate vicinity of the starting point, to the extent that it can be considered the starting point. That is, the cumulative travel distance CMD = terminal distance CD is assumed to hold true. However, the communication terminal device 12 is not mounted on a moving object, and its position does not move.

[0067] The communication terminal device 12 includes a CPU 120, a storage device 121, an operation unit 122, a display unit 123, and a wireless communication unit 125.

[0068] As shown in Figure 3, the history information 175 includes time information 176, radio wave strength information 177, predicted radio wave strength information 178, corrected radio wave strength information 179, and location information 180.

[0069] As will be explained in more detail later, the history information 175 is a database with a table structure in which one record is created each time the radio wave strength is measured. Each record in the history information 175 stores time information 176 indicating the time the radio wave strength was measured, radio wave strength information 177 indicating the radio wave strength measured at that time, predicted radio wave strength information 178 indicating the radio wave strength expected at the next measurement time, corrected radio wave strength information 179 indicating the corrected radio wave strength after correcting the radio wave strength measured at that time, and location information 180 indicating the position of the mobile device (mobile communication terminal device 11) at that time, and these are all related to each other.

[0070] Furthermore, acquired information 181 is a general term for the information acquired by the communication terminal device 12. Acquired information 181 includes information obtained from external devices via the wireless communication unit 125 and information input by operating the operation unit 122. Acquired information 181 may also include pre-stored information, such as setting information.

[0071] Furthermore, output information 182 is a general term for information transmitted to an external device via the wireless communication unit 125, and information output by being displayed on the display unit 123. If the communication terminal device 12 is equipped with a speaker, output information 182 may also be related to voice information.

[0072] The CPU 120 reads and executes the program 812 stored in the memory device 121, performing calculations on various data and generating control signals. Thus, the CPU 120 controls the various components of the communication terminal device 12 and has the function of calculating and creating various data. In other words, the communication terminal device 12 is configured as a general-purpose computer.

[0073] The storage device 121 provides the function of storing various data in the communication terminal device 12. In other words, the storage device 121 stores electronically fixed information in the communication terminal device 12. As shown in Figure 3, the storage device 121 is used to store the program 812, history information 175, acquired information 181, and output information 182, etc. Note that the storage device 121 has the same configuration as the storage device 111, except that it is accessed by the CPU 120. Therefore, a detailed explanation is omitted here.

[0074] The operation unit 122 is hardware that an operator or other person operates to input instructions to the communication terminal device 12. The information input in this way is transmitted to the CPU 120 and stored in the storage device 121 as acquired information 181. Examples of the operation unit 122 include various keys and buttons, switches, touch panels, pointing devices, or jog dials.

[0075] The display unit 123 is hardware that has the function of outputting various data (for example, output information 182) to operators, etc. Examples of the display unit 123 include lamps, LEDs, CRTs, liquid crystal displays, and liquid crystal panels.

[0076] The wireless communication unit 125 provides the function for the communication terminal device 12 to communicate wirelessly with an external device (mobile communication terminal device 11). As a result, in the first embodiment, the communication terminal device 12 performs wireless communication with the mobile communication terminal device 11 in accordance with the Wi-Fi HaLow standard.

[0077] The data received by the wireless communication unit 125 from the mobile communication terminal device 11 is transmitted to the CPU 120. The information thus acquired is stored in the storage device 121 as acquired information 181. On the other hand, the information transmitted by the wireless communication unit 125 (for example, output information 182) is transmitted from the CPU 120.

[0078] Furthermore, the wireless communication unit 125 also has the function of measuring the strength of radio waves transmitted from the mobile communication terminal device 11 and transmitting it to the CPU 120. In other words, the wireless communication unit 125 constitutes a strength acquisition unit that acquires the radio wave strength between the mobile communication terminal device 11 and the communication terminal device 12. The radio wave strength acquired in this way is stored in the storage device 121 as radio wave strength information 177. The wireless communication unit 125 measures the radio wave strength at predetermined time intervals and transmits it to the CPU 120. In the following description, the time interval at which the wireless communication unit 125 measures the radio wave strength will be referred to as "time i". In other words, unless otherwise specified, the communication terminal device 12 creates radio wave strength information 177 each time time i has elapsed.

[0079] Although not shown in Figure 3, the communication terminal device 12 is equipped with a timer for measuring time. Furthermore, the configuration of the communication terminal device 12 is not limited to that shown in Figure 3. For example, the communication terminal device 12 may be equipped with a sensor that takes observed information as acquired information 181, or a speaker that outputs information related to voice.

[0080] Figure 4 is a diagram showing the functional blocks of the communication terminal device 12 in the first embodiment, along with the data flow. The data acquisition unit 150, data output unit 151, history acquisition unit 152, intensity prediction unit 153, intensity correction unit 154, and location identification unit 155 shown in Figure 4 are functional blocks realized by the CPU 120 operating according to the program 812.

[0081] The data acquisition unit 150 has the function of creating acquired information 181 based on the information transmitted from the operation unit 122 and the wireless communication unit 125. The acquired information 181 created by the data acquisition unit 150 is stored in the storage device 121.

[0082] The data output unit 151 has the function of selecting and transmitting the output information 182 from among the display unit 123 and the wireless communication unit 125 according to the output information 182. For example, for output information 182 that should be output (displayed) toward the display unit 123, the display unit 123 is selected as the output destination and the display unit 123 is controlled to display the output information 182. Also, for output information 182 that should be output (transmitted) toward the mobile communication terminal device 11, the wireless communication unit 125 is selected as the output destination and the wireless communication unit 125 is controlled to transmit the output information 182 toward the mobile communication terminal device 11.

[0083] Furthermore, the data output unit 151 also has the function of editing the output information 182 by referring to the history information 175 as needed. For example, when displaying location information 180 included in the history information 175 on the display unit 123, the location information 180 is obtained from the history information 175 and used as output information 182. Although not shown in the figures, the data output unit 151 may also have the function of editing the output information 182 according to the acquired information 181.

[0084] The history acquisition unit 152 creates a new record in the history information 175 each time the radio wave strength is acquired by the wireless communication unit 125 (strength acquisition unit) (i.e., every time time i elapses). The newly created record stores the time (time information 176) when the radio wave strength was acquired by the wireless communication unit 125 and the radio wave strength (radio wave strength information 177). In this way, the history acquisition unit 152 has the function of acquiring history information 175 by creating history information 175. For convenience, in this explanation, the creation of a new record in history information 175 may be simply referred to as "creating history information 175".

[0085] The intensity prediction unit 153 has the function of obtaining predicted radio wave intensity information 178 by predicting the radio wave intensity to be acquired next based on the history information 175, and storing it in the history information 175. The method by which the intensity prediction unit 153 creates the predicted radio wave intensity information 178 will be described later.

[0086] The intensity correction unit 154 has the function of obtaining corrected radio wave strength by correcting the radio wave strength included in the history information 175 according to the predicted radio wave strength, and storing it in the history information 175 as corrected radio wave strength information 179. The method by which the intensity correction unit 154 creates the corrected radio wave strength information 179 will be described later.

[0087] The position identification unit 155 has the function of identifying the position of a moving object and creating position information 180 based on the corrected radio wave intensity information 179 included in the history information 175. In Figure 4, the position identification unit 155 is shown as being included in the intensity prediction unit 153. However, the position identification unit 155 may be provided independently of the intensity prediction unit 153. The method by which the position identification unit 155 identifies the position of a moving object and creates position information 180 will be described later.

[0088] The above describes the configuration and functions of the radio wave intensity correction system 10 in the first embodiment. Next, a method for correcting radio wave intensity using the radio wave intensity correction system 10 will be described.

[0089] Figure 5 is a flowchart showing the radio wave correction method in the first embodiment. It is assumed that before each step shown in Figure 5 is started, program 811 is stored in the mobile communication terminal device 11 and program 812 is stored in the communication terminal device 12. It is also assumed that radio wave transmission from the mobile communication terminal device 11 has already started. Furthermore, the mobile object is positioned at the starting point and begins moving after the process shown in Figure 5 has started.

[0090] The radio wave intensity correction system 10 (communication terminal device 12) constantly monitors whether it is the measurement timing (step S1) and whether history information 175 has been created (step S4) when it is in operation.

[0091] In the operation state of the radio wave intensity correction system 10, when time i has elapsed since the last measurement and the measurement timing has arrived, the CPU 120 determines Yes in step S1. More specifically, in the communication terminal device 12, a timer (not shown) is constantly measuring time i and is configured to transmit an interrupt signal to the CPU 120 each time that time i has elapsed. The CPU 120 is constantly monitoring the interrupt signal from the timer and determines Yes in step S1 each time that interrupt signal is transmitted.

[0092] If the answer is Yes in step S1, the CPU 120 obtains the current time (time T in the measurement period) and the radio wave strength (step S2).

[0093] In step S2, first, the wireless communication unit 125 measures the radio wave strength in response to the control of the CPU 120, acquires radio wave strength information 177, and transmits it to the CPU 120 (history acquisition unit 152). Next, the history acquisition unit 152 records the time when the radio wave strength information 177 was transmitted as time information 176.

[0094] When step S2 is executed and time information 176 and radio wave strength information 177 are acquired, the history acquisition unit 152 creates a new record in the history information 175 (step S3) and stores the time information 176 and radio wave strength information 177 acquired in step S2 in that record.

[0095] Once the processing in step S3 is complete, the radio wave intensity correction system 10 (communication terminal device 12) returns to the operational state. That is, it returns to the state of monitoring the measurement timing (step S1) and whether or not the history information 175 has been created (step S4).

[0096] In the operational state, when a new record of history information 175 is created, the radio wave strength correction system 10 (CPU 120) determines Yes in step S4. The newly created record contains time information 176 and radio wave strength information 177, but does not contain predicted radio wave strength information 178 or corrected radio wave strength information 179. Therefore, the processing in step S4 can be determined, for example, by whether or not there is a record in the history information 175 that does not contain predicted radio wave strength information 178.

[0097] In the following explanation of steps S5 and S6, the record of history information 175 that was determined to be a newly created record in step S4 may be referred to as the "record to be processed." Also, after the record to be processed is created in step S3, it is generally identified immediately in step S4, and the processing in steps S5 and S6 is then executed. Therefore, the time information 176 stored in the record to be processed can be considered as the current time (time T) in steps S5 and S6.

[0098] If the result in step S4 is determined to be Yes, the intensity correction unit 154 performs radio wave intensity correction processing (step S5).

[0099] Figure 6 is a flowchart showing the radio wave intensity correction process in the first embodiment.

[0100] Generally, the intensity of radio waves used in wireless communication is affected by the path (conduction path) along which the radio waves travel before being received (measured). Various factors can affect radio wave intensity, such as temperature, humidity, reflection, and absorption along the conduction path, but for example, the distance of the conduction path (conduction distance TD) has a significant impact.

[0101] Therefore, if the conducted distance TD can be considered as the terminal distance CD, the reliability of the correlation between the measured radio wave intensity and the terminal distance CD improves, which is ideal. On the other hand, the conducted distance TD can change significantly due to reflections, the presence of shielding, etc. In such cases, the conducted distance TD cannot be considered as the terminal distance CD, and the reliability of the correlation between the measured radio wave intensity and the terminal distance CD decreases.

[0102] As will be explained in more detail later, the radio wave intensity correction process shown in Figure 6 is a process that determines the reliability of the measured radio wave intensity and corrects it to a more reliable intensity if the reliability is low. Here, "reliability" refers to the reliability of the correlation between the measured radio wave intensity and the terminal distance CD, and not, for example, measurement accuracy.

[0103] When the radio wave intensity correction process is started, the intensity correction unit 154 acquires the radio wave intensity information 177 stored in the record to be processed as the radio wave intensity to be corrected (step S11).

[0104] Next, the intensity correction unit 154 determines whether the record to be processed is the first record (step S12). The process in step S12 can be determined, for example, by checking whether multiple records of the history information 175 have already been created. Alternatively, the unit may refer to the time information 176 stored in the record to be processed and determine whether there is a record that stores time information 176 earlier than the said time information 176.

[0105] At the time the first record is created, the mobile object has not yet started moving and is presumably stationary at its starting position. The communication terminal device 12 is installed in the immediate vicinity of the starting position. In other words, because the distance between the mobile object and the communication terminal device 12 is short, the impact of conditions such as multipath interference on the radio wave intensity correction system 10 is considered to be negligibly low at the time the first record is created. Therefore, the reliability of the measured radio wave intensity is considered high.

[0106] In other words, if the record to be processed is the first record (Yes in step S12), the intensity correction unit 154 assumes that it does not need to correct the acquired radio wave intensity to be corrected. Therefore, the intensity correction unit 154 acquires the corrected radio wave intensity information 179 as the radio wave intensity to be corrected as is (step S13).

[0107] When step S13 is executed and the corrected radio wave intensity information 179 is acquired, the intensity correction unit 154 stores the acquired corrected radio wave intensity information 179 in the processing target record of the history information 175 (step S19).

[0108] When step S19 is executed, the radio wave intensity correction system 10 in the first embodiment finishes the radio wave intensity correction process (step S5) and returns to the process shown in Figure 5.

[0109] On the other hand, if step S12 determines No (i.e., the record to be processed is not the first record), the intensity correction unit 154 refers to the history information 175 and obtains the predicted radio wave intensity information 178 and radio wave intensity information 177 stored in the record immediately preceding the record to be processed (hereinafter referred to as the "comparison record") (step S14). If the time information 176 of the record to be processed is "time T", then the time information 176 of the comparison record, which is the immediately preceding record, is "time (Ti)".

[0110] As will be explained in more detail later, the predicted radio wave strength information 178 stored in the comparison record is information that predicted the radio wave strength to be measured this time at the time of the previous measurement. In other words, the predicted radio wave strength information 178 obtained in step S14 is information that predicts the radio wave strength information 177 of the record to be processed.

[0111] When the processing in step S14 is completed, the intensity correction unit 154 calculates the amount of change in radio wave intensity during time i based on the corrected radio wave intensity information 179 of the comparison record (a value obtained by correcting the radio wave intensity measured at time (Ti)) and the radio wave intensity information 177 of the processing record (a radio wave intensity measured at time T) (step S15).

[0112] Next, the intensity correction unit 154 determines whether the radio wave intensity has increased based on the amount of change obtained in step S15 (step S16). In the first embodiment, the moving object does not approach the communication terminal device 12, and therefore the radio wave intensity does not increase. In other words, if the radio wave intensity has increased, the radio wave intensity measured this time (radio wave intensity information 177 of the record to be processed) can be considered unreliable and inappropriate.

[0113] Therefore, if the result in step S16 is Yes, the intensity correction unit 154 discards the radio wave intensity information 177 of the record to be processed and obtains the corrected radio wave intensity information 179 as the predicted radio wave intensity of the record to be compared (step S18).

[0114] When step S18 is executed and the corrected radio wave intensity information 179 is acquired, the intensity correction unit 154 stores the acquired corrected radio wave intensity information 179 in the processing target record of the history information 175, just as when step S13 was executed (step S19).

[0115] As already explained, when step S19 is executed, the radio wave intensity correction system 10 in the first embodiment terminates the radio wave intensity correction process (step S5) and returns to the process shown in Figure 5.

[0116] Returning to the process in step S16, if the result in step S16 is determined to be No, then it is determined whether the radio wave strength information 177 of the record to be processed is within the range, according to the predicted radio wave strength information 178 of the comparison record obtained in step S14 (step S17).

[0117] In step S17, the intensity correction unit 154 first calculates the prediction error Q (absolute value) between the predicted radio wave intensity information 178 (the radio wave intensity predicted immediately before (time (Ti))) acquired in step S14 and the radio wave intensity information 177 (the radio wave intensity actually measured this time (time T)) acquired in step S11. Next, if the prediction error Q is within the allowable error R, the unit determines Yes in step S17. On the other hand, if the prediction error Q is greater than the allowable error R, the unit determines No in step S17.

[0118] The tolerance error R is a threshold used to determine whether the error (prediction error Q) between the predicted radio wave strength (predicted radio wave strength information 178) and the actually measured radio wave strength (radio wave strength information 177) is within an acceptable range. If the prediction error Q is within the tolerance error R, the radio wave strength information 177 is close to the predicted radio wave strength information 178 and can be judged as a reliable value. However, if the prediction error Q is greater than the tolerance error R, the radio wave strength information 177 has a large error compared to the predicted radio wave strength information 178 and can be judged as an unreliable value.

[0119] Generally, radio waves attenuate significantly near the source (mobile communication terminal device 11) depending on the terminal distance CD, and attenuate less at greater distances. That is, when the distance between the mobile communication terminal device 11 and the communication terminal device 12 is short, it is preferable that the allowable error R be a relatively large value, and when the distance is long, it is preferable that the allowable error R be a relatively small value.

[0120] Therefore, the intensity correction unit 154 calculates the difference between the corrected radio wave intensity information 179 and the predicted radio wave intensity information 178 stored in the comparison record, and sets the absolute value of the calculated value as the allowable error R. Note that the allowable error R is not limited to such a value. For example, it may be a predetermined percentage of the above value, or a constant value may be used.

[0121] If the result in step S17 is "Yes", the intensity correction unit 154 determines that the radio wave intensity information 177 of the record to be processed is reliable and executes step S13. That is, as already explained, the corrected radio wave intensity information 179 is obtained using the radio wave intensity (radio wave intensity information 177 of the record to be processed) obtained in step S11 as the corrected radio wave intensity.

[0122] However, if step S17 determines that the result is No, the intensity correction unit 154 determines that the radio wave intensity information 177 of the record to be processed is unreliable and executes step S18. That is, as already explained, the radio wave intensity obtained in step S11 is discarded, and the corrected radio wave intensity information 179 is obtained using the predicted radio wave intensity information 178 of the comparison record obtained in step S14 as the corrected radio wave intensity.

[0123] In the radio wave intensity correction system 10 of the first embodiment, the execution of step S18 corresponds to a correction being performed in which the unreliable radio wave intensity (measured value) is rewritten with the predicted radio wave intensity (predicted value). However, the correction method is not limited to this. For example, a correction value may be calculated by weighting according to the value of the deviation from the predicted radio wave intensity (prediction error Q), and the correction may be performed by adding this correction value to the radio wave intensity.

[0124] Thus, in the first embodiment, the intensity correction unit 154 corrects the radio wave intensity information 177 included in the history information 175 according to the predicted radio wave intensity information 178 to obtain corrected radio wave intensity information 179, and stores it in the history information 175. Therefore, for example, by creating predicted radio wave intensity information 178 that suppresses the influence of events other than the terminal distance CD between the mobile communication terminal device 11 and the communication terminal device 12, the influence of events other than the terminal distance CD between the mobile communication terminal device 11 and the communication terminal device 12 on the radio wave intensity information 177 can be suppressed.

[0125] Once step S13 or step S18 is executed and the corrected radio wave intensity information 179 is acquired, the intensity correction unit 154 stores the acquired corrected radio wave intensity information 179 in the record to be processed (step S19), as previously described. Also, as previously described, once step S19 is executed, the radio wave intensity correction system 10 in the first embodiment terminates the radio wave intensity correction process (step S5) and returns to the process shown in Figure 5.

[0126] Once the process in step S5 shown in Figure 5 is completed, the radio wave intensity correction system 10 (CPU 120) performs radio wave intensity prediction processing (step S6).

[0127] Figure 7 is a flowchart showing the radio wave intensity prediction process in the first embodiment. When the radio wave intensity prediction process is started, the intensity prediction unit 153 acquires the corrected radio wave intensity information 179 stored in the newly created record (processing target record) identified in step S4 (step S20).

[0128] In the radio wave intensity correction system 10 of the first embodiment, when the radio wave intensity prediction process (step S6) is executed, step S5 (step S19) has already been executed. Therefore, the corrected radio wave intensity information 179 is already stored in the record to be processed. Accordingly, the intensity prediction unit 153 can execute step S20 to obtain the corrected radio wave intensity information 179 stored in the record to be processed. When executing step S20, the intensity prediction unit 153 may refer to the acquired information 181 to obtain the information necessary for the radio wave intensity prediction process.

[0129] Next, the intensity prediction unit 153 determines whether the record to be processed is the first record (step S21). The process in step S21 can be performed, for example, in the same way as the process in step S12.

[0130] At the time the first record is created, the moving object has not yet started moving and is considered to be stationary at its starting position. Therefore, if the record to be processed is the first record (Yes in step S21), the position identification unit 155 acquires position information 180 with the position of the moving object set to "0", and the intensity prediction unit 153 stores the position information 180 in the record to be processed in the history information 175 (step S22).

[0131] Furthermore, since the moving object is considered to be stationary when the first record is created, the intensity of the radio waves from the stationary mobile communication terminal device 11 is not expected to change. Therefore, the intensity prediction unit 153 predicts that the corrected radio wave intensity of the record to be processed that is being acquired will be the radio wave intensity to be measured next. In other words, the intensity prediction unit 153 acquires predicted radio wave intensity information 178 using the corrected radio wave intensity of the record to be processed as the predicted radio wave intensity (step S23).

[0132] When step S23 is executed and the predicted radio wave intensity information 178 is acquired, the intensity prediction unit 153 stores the acquired predicted radio wave intensity information 178 in the processing target record of the history information 175 (step S29).

[0133] Thus, in the first record, step S23 acquires the radio wave strength indicated in the corrected radio wave strength information 179 as the predicted radio wave strength information 178. Therefore, the predicted radio wave strength information 178 of the first record will have the same value as the radio wave strength information 177 stored in that record. Also, as already explained, in the first record, step S13 acquires the radio wave strength indicated in the radio wave strength information 177 as the corrected radio wave strength information 179. Therefore, the corrected radio wave strength information 179 of the first record will have the same value as the radio wave strength information 177 stored in that record. In other words, in the first embodiment, the first record of the history information 175 stores the same values ​​in the radio wave strength information 177, predicted radio wave strength information 178, and corrected radio wave strength information 179.

[0134] When step S29 is executed, the radio wave intensity correction system 10 in the first embodiment finishes the radio wave intensity prediction process (step S6) and returns to the process shown in Figure 5.

[0135] On the other hand, if step S21 determines No (i.e., the record to be processed is not the first record), the location identification unit 155 obtains the location PO(T) and stores it in the history information 175 as location information 180 (step S24).

[0136] The process in step S24 will be explained in detail. First, the positioning unit 155 determines the current conduction distance TD using equation 1 based on the acquired corrected radio wave intensity information 179.

[0137] Lb(T)=20·log(2π / λ)+10n·log(TD(T)) ···Equation 1

[0138] In Equation 1, "Lb(T)" is the radio wave intensity, "λ" is the wavelength of the radio wave, and "n" is the transfer coefficient. Equation 1 can be adapted to various situations depending on the transfer coefficient n. For example, if n < 2.0, it can be assumed that radio waves are transmitted while being reflected, such as in a waveguide. Also, if n > 2.0, it can represent the situation in which radio waves are absorbed and attenuated by obstacles as they propagate. However, in the first embodiment, the position identification unit 155 assumes an ideal space without obstacles, so n is set to "2.0".

[0139] Furthermore, although Lb(T) in Equation 1 represents the radio wave intensity, the positioning unit 155 does not use the current radio wave intensity information 177 as Lb(T), but rather uses the current corrected radio wave intensity information 179. In other words, the positioning unit 155 uses the corrected radio wave intensity, which has been corrected to improve the accuracy of the correlation with the terminal distance CD(T), rather than the radio wave intensity actually measured at the present time. As a result, the conducted distance TD(T) obtained from Equation 1 can suppress the effects of multipath and other factors. Therefore, the conducted distance TD(T) obtained from Equation 1 can be considered as the terminal distance CD(T).

[0140] In this way, the location identification unit 155 obtains the current terminal distance CD(T) using equation 1. As already explained, the current terminal distance CD(T) can be considered as the current location PO(T) of the moving object. Therefore, the location PO(T) obtained by the location identification unit 155 using equation 1 is stored as location information 180 in the processing target record by the intensity prediction unit 153. That is, in the radio wave intensity correction system 10 in the first embodiment, when step S24 is executed, the location of the moving object is identified, location information 180 is obtained, and it is stored in the history information 175.

[0141] Once the current position is determined in step S24, the intensity prediction unit 153 obtains the distance the moving object has traveled (along the path) during the period from the time the radio wave intensity was measured last time until the time the radio wave intensity is measured this time (from time (Ti) to time T) (hereinafter referred to as "recent travel distance md(T)") (step S25).

[0142] Here, since the moving object moves in a straight line and without reversing direction, the relationship between the most recent distance traveled md(T), the cumulative distance traveled up to the present (time T) CMD(T), and the cumulative distance traveled up to the previous time (time (Ti)) CMD(Ti) is expressed by the following equation 2.

[0143] md(T)=CMD(T)-CMD(Ti) ··· Formula 2

[0144] Furthermore, in the first embodiment, the cumulative travel distance CMD(T) = terminal distance CD(T). Since the terminal distance CD(T) is the relative distance between the mobile body and the communication terminal device 12, in the first embodiment, the terminal distance CD(T) = the position PO(T) of the mobile body. In other words, the cumulative travel distance CMD(T) is expressed by the position PO(T) of the mobile body.

[0145] Therefore, the intensity prediction unit 153 can obtain the cumulative distance traveled up to the previous time CMD(Ti) by acquiring position information 180 (position PO(Ti)) representing the position of the moving object in the previous instance from the previous record (record for time (Ti)).

[0146] The cumulative distance traveled to date, CMD(T), is the position PO(T) obtained in step S24. Therefore, the intensity prediction unit 153 can execute Equation 2 to determine the most recent distance traveled, md(T).

[0147] After step S25 is executed and the most recent travel distance md(T) is obtained, the intensity prediction unit 153 obtains the current velocity of the moving object (step S26).

[0148] In step S26, the intensity prediction unit 153 determines the current velocity of the moving object by dividing the most recent moving velocity md(T) by time i. Strictly speaking, the velocity obtained in this way is not the current velocity, but the average velocity of the moving object from time (Ti) to time T. However, if we assume that the time interval (time i) for measuring the radio wave intensity is sufficiently small, the velocity of the moving object can be considered constant.

[0149] Next, the intensity prediction unit 153 obtains the distance the moving object will travel until the next measurement (hereinafter referred to as "predicted travel distance fmd(T+i)") (step S27).

[0150] Here, since the measurement interval (time i) is constant, in the first embodiment, the predicted travel distance fmd(T+i) is ultimately the most recent travel distance md(T) obtained in step S25. Therefore, the next terminal distance CD(T+i) can be expressed by equation 3.

[0151] CD(T+i)=CD(T)+md(T) ··· Equation 3

[0152] By substituting the predicted next terminal distance CD(T+i) into Equation 1, treating it as the conducted distance TD(T+i), the predicted next radio wave intensity can be obtained as Lb(T+i), and the predicted radio wave intensity information 178 can be acquired (step S28).

[0153] When step S28 is executed and the predicted radio wave intensity information 178 is acquired, the intensity prediction unit 153 stores the acquired predicted radio wave intensity information 178 in the processing target record of the history information 175 (step S29).

[0154] As already explained, when step S29 is executed, the radio wave intensity correction system 10 in the first embodiment terminates the radio wave intensity prediction process (step S6) and returns to the process shown in Figure 5.

[0155] After completing step S6 and returning to Figure 5, the radio wave intensity correction system 10 returns to its operational state.

[0156] As described above, the radio wave strength correction system 10 in the first embodiment includes a mobile communication terminal device 11 mounted on a mobile body, a communication terminal device 12 that communicates wirelessly with the mobile communication terminal device 11, a strength acquisition unit (wireless communication unit 125) that acquires the wireless radio wave strength between the mobile communication terminal device 11 and the communication terminal device 12, a history acquisition unit 152 that acquires history information 175 that associates the time when the radio wave strength was acquired by the wireless communication unit 125 with the radio wave strength, a strength prediction unit 153 that acquires a predicted radio wave strength by predicting the radio wave strength to be acquired next based on the history information 175 and stores it in the history information 175, and a strength correction unit 154 that acquires a corrected radio wave strength by correcting the radio wave strength included in the history information 175 according to the predicted radio wave strength and stores it in the history information 175.Therefore, correction can be made according to the purpose of use of the radio wave strength.As a result, for example, the influence of events other than the distance between the mobile communication terminal device 11 and the communication terminal device 12 on the radio wave strength can be suppressed.

[0157] Furthermore, the system includes a position identification unit 155 that identifies the location of a moving object based on the corrected radio wave intensity included in the history information 175. This makes it possible to suppress the influence of events other than terminal distance on radio wave intensity, for example, and improves the accuracy of detecting the location of a moving object.

[0158] In the first embodiment of the radio wave intensity correction system 10, it was explained that the history acquisition unit 152, intensity prediction unit 153, intensity correction unit 154, and location identification unit 155 are all provided by the communication terminal device 12. However, some or all of these components may be provided by the mobile communication terminal device 11. In that case, the functional blocks provided in the mobile communication terminal device 11 can be realized by the CPU 110 operating according to the program 811, and the necessary information can be acquired as acquisition information 170 while the necessary information can be output as output information 171.

[0159] Furthermore, although details have been omitted, the position PO(T) identified by the position identification unit 155 in the first embodiment is strictly a relative position to the communication terminal device 12. In order to convert this into an absolute position that can be used by external devices other than the communication terminal device 12, for example, the communication terminal device 12 can be configured to acquire and store its own position as an absolute position.

[0160] <2. Second Embodiment> In the first embodiment, an example was described in which the radio wave strength correction system 10 is corrected by one communication terminal device 12. However, the number of communication terminal devices 12 is not limited to one.

[0161] Figure 8 is a configuration diagram of the radio wave intensity correction system 20 in the second embodiment. The radio wave intensity correction system 20 in the second embodiment differs from the radio wave intensity correction system 10 in the first embodiment in that it includes two communication terminal devices 22 and 23 instead of the communication terminal device 12, and it includes a server device 24 installed indoors, such as in a management center. In the following description, the same reference numerals are used for components of the radio wave intensity correction system 20 in the second embodiment as in the radio wave intensity correction system 10 in the first embodiment, and their descriptions are omitted as appropriate.

[0162] In the second embodiment shown in Figure 8, the network 92 is assumed to be a wired communication network, but it may also be a wireless communication network. The network 92 connects the communication terminal device 22, the communication terminal device 23, and the server device 24 in a manner that enables data communication between them.

[0163] Furthermore, for the sake of simplicity, in the second embodiment, the moving body is assumed to move linearly from the starting position shown in Figure 1 toward the ending position (without moving backward). Also, the communication terminal devices 22 and 23 are devices that are positioned at different locations from each other.

[0164] Figure 9 is a block diagram showing the communication terminal device 22 in the second embodiment. Since the communication terminal device 22 in the second embodiment has the same configuration as the communication terminal device 23, the configuration of the communication terminal device 23 will be omitted in the following description unless otherwise specified. However, the communication terminal device 22 and the communication terminal device 23 are not necessarily identical devices.

[0165] The communication terminal device 22 includes a CPU 220, a storage device 221, an operation unit 222, a display unit 223, a communication unit 224, and a wireless communication unit 225.

[0166] The time information 276 shown in Figure 9 corresponds to the time information 176 in the first embodiment, but the details will be described later.

[0167] Furthermore, the radio wave strength information 277 corresponds to the radio wave strength information 177 in the first embodiment, but the details will be described later.

[0168] Furthermore, acquired information 281 is a general term for the information acquired by the communication terminal device 22. Acquired information 281 includes information obtained from external devices via the communication unit 224 or the wireless communication unit 225, and information input by operating the operation unit 222. Acquired information 281 may also include pre-stored information, such as setting information.

[0169] Furthermore, output information 282 is a general term for information transmitted to an external device via the communication unit 224 or the wireless communication unit 225, or information output by being displayed on the display unit 223. If the communication terminal device 22 is equipped with a speaker, output information 282 may also be related to voice information.

[0170] The CPU 220 reads and executes the program 822 stored in the memory device 221, performing calculations on various data and generating control signals. Thus, the CPU 220 controls the various components of the communication terminal device 22 and has the function of calculating and creating various data. In other words, the communication terminal device 22 is configured as a general-purpose computer.

[0171] The storage device 221 provides a function for storing various data in the communication terminal device 22. In other words, the storage device 221 stores electronically fixed information in the communication terminal device 22. As shown in Figure 9, the storage device 221 is used to store the program 822, time information 276, radio wave strength information 277, acquired information 281, and output information 282, etc. Note that the storage device 221 can be configured as a device equivalent to the storage device 111 in the first embodiment, except that it is accessed by the CPU 220, so a detailed explanation is omitted here.

[0172] The operation unit 222 is hardware that an operator or other person operates to input instructions to the communication terminal device 22. The information input in this way is transmitted to the CPU 220 and stored in the storage device 221 as acquired information 281. Examples of the operation unit 222 include various keys and buttons, switches, touch panels, pointing devices, or jog dials.

[0173] The display unit 223 is hardware that has the function of outputting various data (for example, output information 282) to operators, etc. Examples of the display unit 223 include lamps, LEDs, CRTs, liquid crystal displays, and liquid crystal panels.

[0174] The communication unit 224 provides the function for the communication terminal device 22 to perform data communication with external devices (communication terminal device 23 and server device 24). As a result, in the second embodiment, the communication terminal device 22 performs data communication with the communication terminal device 23 and the server device 24 via the network 92.

[0175] Information received by the communication unit 224 is transmitted to the CPU 220 and stored in the memory device 221 as acquired information 281. Information to be transmitted by the communication unit 224 (for example, output information 282) is transmitted from the CPU 220.

[0176] The wireless communication unit 225 provides the communication terminal device 22 with the function to communicate wirelessly with an external device (mobile communication terminal device 11). As a result, in the second embodiment, the communication terminal device 22 communicates wirelessly with the mobile communication terminal device 11 in accordance with the Wi-Fi HaLow standard.

[0177] The data received by the wireless communication unit 225 from the mobile communication terminal device 11 is transmitted to the CPU 220. The information acquired in this way is stored in the storage device 221 as acquired information 281.

[0178] Furthermore, the wireless communication unit 225 also has the function of measuring the strength of radio waves transmitted from the mobile communication terminal device 11 and transmitting this information to the CPU 220. In other words, the wireless communication unit 225 constitutes a strength acquisition unit that acquires the radio wave strength between the mobile communication terminal device 11 and the communication terminal device 22. The radio wave strength acquired in this manner is stored in the storage device 221 as radio wave strength information 277. The wireless communication unit 225, like the wireless communication unit 125 in the first embodiment, measures the radio wave strength at predetermined time intervals i and transmits the information to the CPU 220.

[0179] Figure 10 is a diagram showing the functional blocks of the communication terminal device 22 in the second embodiment, along with the data flow. The data acquisition unit 250, data output unit 251, and device identification unit 252 shown in Figure 10 are functional blocks realized by the CPU 220 operating according to program 822.

[0180] The data acquisition unit 250 has the function of creating acquired information 281 based on information transmitted from the operation unit 222, the communication unit 224, and the wireless communication unit 225. The acquired information 281 created by the data acquisition unit 250 is stored in the storage device 221.

[0181] In particular, although not shown in Figure 9, the data acquisition unit 250 acquires the associated time information 276 and radio wave strength information 277 from the communication unit 224 to create acquired information 281. The time information 276 and radio wave strength information 277 included in the acquired information 281 are information transmitted from the communication terminal device 23 in the case of acquired information 281 of the communication terminal device 22, and information transmitted from the communication terminal device 22 in the case of acquired information 281 of the communication terminal device 23.

[0182] Thus, the communication terminal device 22 (communication terminal device 23) is configured to acquire radio wave strength information 277 measured by other communication terminal devices 23 (communication terminal device 22) in association with time information 276. It should be noted that the acquired information 281 does not necessarily include time information 276 and radio wave strength information 277; acquired information 281 that does not include these naturally exists.

[0183] Furthermore, the data acquisition unit 250 has the function of creating measurement information 283 by associating the radio wave strength information 277, which is measured and acquired every time i by the wireless communication unit 225, with time information 276 indicating the time of acquisition, and storing it in the storage device 221. Unlike the acquired information 281, the created measurement information 283 always includes the time information 276 and radio wave strength information 277 that are associated with each other.

[0184] The data output unit 251 has the function of selecting and transmitting the output destination of the output information 282 from among the display unit 223, communication unit 224, and wireless communication unit 225, according to the output information 282. For example, for output information 282 that should be output (displayed) to the display unit 223, the display unit 223 is selected as the output destination, and the display unit 223 is controlled to display the output information 282.

[0185] Furthermore, with respect to output information 282 to be output (transmitted) to the server device 24 (or communication terminal device 23), the communication unit 224 is selected as the output destination, and the communication unit 224 is controlled to transmit the output information 282 to the server device 24 (or communication terminal device 23). For example, output information 282 that should be transmitted to the server device 24 (or communication terminal device 23) may include measurement information 283.

[0186] Furthermore, the data output unit 251 selects the wireless communication unit 225 as the output destination for output information 282 to be output (transmitted) to the mobile communication terminal device 11, and controls the wireless communication unit 225 to transmit the output information 282 to the mobile communication terminal device 11.

[0187] The device identification unit 252 has the function of identifying a target communication terminal device from among the multiple communication terminal devices 22, 23 by comparing the radio wave strength between the multiple communication terminal devices 22, 23 and the mobile communication terminal device 11. Details of the device identification unit 252 will be described later, but the target communication terminal device is the device that provides the information (time information 176 and radio wave strength information 177) that forms the basis for creating the history information 175. In other words, the information acquired at the target communication terminal device is used as the information for creating the history information 175.

[0188] Figure 11 is a block diagram showing the server device 24 in the second embodiment. As already described, the server device 24 is a device mainly installed indoors.

[0189] The server device 24 includes a CPU 240, a storage device 241, an operation unit 242, a display unit 243, and a communication unit 244.

[0190] The acquired information 284 is a general term for the information acquired by the server device 24. The acquired information 284 includes information obtained from external devices via the communication unit 244 and information input by operating the operation unit 242. The acquired information 284 may also include pre-stored information, such as setting information.

[0191] Furthermore, output information 285 is a general term for information transmitted to external devices via the communication unit 244 and information output by being displayed on the display unit 243. If the server device 24 is equipped with a speaker, output information 285 may also be related to audio.

[0192] The CPU 240 reads and executes the program 824 stored in the memory device 241, performing calculations on various data and generating control signals. Thus, the CPU 240 controls the various components of the server device 24 and has the function of calculating and creating various data. In other words, the server device 24 is configured as a general-purpose computer.

[0193] The storage device 241 provides the function of storing various data in the server device 24. In other words, the storage device 241 stores electronically fixed information in the server device 24. As shown in Figure 11, the storage device 241 is used to store the program 824, history information 175, acquired information 284, and output information 285, etc. Note that the storage device 241 can be configured as a device equivalent to the storage device 111 in the first embodiment, except that it is accessed by the CPU 240, so a detailed explanation is omitted here.

[0194] Furthermore, although not shown in Figure 11, the storage device 241 is assumed to acquire and store the location (absolute position) of the communication terminal devices 22 and 23 as location information.

[0195] The operation unit 242 is hardware that operators or others use to input instructions to the server device 24. The information input in this way is stored in the storage device 241 as acquired information 284. Examples of the operation unit 242 include various keys and buttons, switches, touch panels, pointing devices, or jog dials.

[0196] The display unit 243 is hardware that has the function of outputting various data (for example, output information 285) to operators, etc. Examples of the display unit 243 include lamps, LEDs, CRTs, liquid crystal displays, and liquid crystal panels.

[0197] The communication unit 244 provides the server device 24 with the function to perform data communication with external devices (communication terminal devices 22, 23). As a result, in the second embodiment, the server device 24 can perform data communication with the communication terminal devices 22, 23 via the network 92.

[0198] The information received by the communication unit 244 is transmitted to the CPU 240 and stored in the storage device 241 as acquired information 284. However, as will be described in detail later, among the information received by the communication unit 244, information related to output information 285 may be stored in the storage device 241 as information that constitutes history information 175, rather than as acquired information 284.

[0199] Furthermore, the information transmitted by the communication unit 244 (for example, output information 285) is transmitted from the CPU 240.

[0200] Although not shown in Figure 11, the server device 24 is equipped with a timer for measuring time. Furthermore, the configuration of the server device 24 is not limited to that shown in Figure 11. For example, the server device 24 may be equipped with a sensor that takes observed information as acquired information 284, a speaker that outputs information related to sound, and so on.

[0201] Figure 12 is a diagram showing the functional blocks of the server device 24 in the second embodiment, along with the data flow. The data acquisition unit 253, data output unit 254, history acquisition unit 255, intensity prediction unit 256, intensity correction unit 257, location identification unit 258, and model acquisition unit 259 shown in Figure 12 are functional blocks realized by the CPU 240 operating according to program 824.

[0202] The data acquisition unit 253 has the function of creating acquired information 284 based on the information transmitted from the operation unit 242 and the communication unit 244. The acquired information 284 created by the data acquisition unit 253 is stored in the storage device 241.

[0203] The acquired information 284 shown in Figure 12 includes route information 286, environmental condition information 287, model information 288, and model database 289. However, this information is not related to each other in the acquired information 284, and unless otherwise specified, it generally exists as separate pieces of information.

[0204] Route information 286 is information indicating the path of a moving object. In the second embodiment, route information 286 is information indicating the absolute position of the starting point and the absolute position of the ending point. However, route information 286 is not limited to this information and may also be information indicating the detailed position of the path of the moving object. For example, it may be information indicating the movement trajectory of the moving object. By acquiring such route information 286 in the second embodiment, the data acquisition unit 253 corresponds to a route acquisition unit that acquires information indicating the path of a moving object.

[0205] Environmental condition information 287 is information indicating the environmental conditions when the radio wave intensity correction system 20 is in operation. Environmental condition information 287 includes at least one of the following: day of the week, time, weather, region, season, indoor / outdoor distinction, type of mobile object, surrounding environment of the mobile object, and path distinction. As will be described in detail later, environmental condition information 287 is used as a search key for searching the model database 289.

[0206] Model information 288 is information that shows the relationship between the distance between the communication terminal device 22 and the mobile communication terminal device 11 (terminal distance CD) and the radio wave intensity. By acquiring such model information 288, the data acquisition unit 253 in the second embodiment also functions as a model acquisition unit.

[0207] Figure 13 shows the structure of the model database 289 in the second embodiment. The model database 289 is a database with a table structure in which one record is created for each environmental condition.

[0208] As shown in Figure 13, the model database 289 is configured to store a record number, environmental condition information 290, and model candidate information 291 in relation to each other within a single record.

[0209] Environmental condition information 290 is information that is compared with environmental condition information 287 when the model database 289 is searched.

[0210] Model candidate information 291 is candidate information for model information 288, and, like model information 288, it is information that shows the relationship between the distance between the communication terminal device 22 and the mobile communication terminal device 11 (terminal distance CD) and the radio wave strength. Model candidate information 291 is associated with environmental condition information 290, and is information that has been adjusted so that the accuracy of the correlation between terminal distance CD and radio wave strength is high when the environmental conditions shown in the associated environmental condition information 290 are met.

[0211] For example, model candidate information A (model candidate information 291), which is associated with "sunny" as environmental condition information 290, is adjusted so that the accuracy of the correlation between terminal distance CD and radio wave strength is higher when the weather is "sunny".

[0212] Model candidate information 291 is not necessarily associated with a single environmental condition. In other words, environmental condition information 290 does not necessarily contain only one environmental condition. For example, model candidate information D shown in Figure 13 is associated with "outdoors" and "vehicle".

[0213] Returning to Figure 12, the data output unit 254 has the function of selecting and transmitting the output destination of the output information 285 from among the display unit 243 and the communication unit 244, according to the output information 285. For example, for output information 285 that should be output (displayed) toward the display unit 243, the display unit 243 is selected as the output destination, and the display unit 243 is controlled to display the output information 285. Also, for output information 285 that should be output (transmitted) toward the communication terminal devices 22 and 23, the communication unit 244 is selected as the output destination, and the communication unit 244 is controlled to transmit the output information 285 toward the communication terminal devices 22 and 23.

[0214] Furthermore, the data output unit 254 also has the function of editing the output information 285 by referring to the history information 175 as needed. For example, when displaying location information 180 included in the history information 175 on the display unit 243, the location information 180 is obtained from the history information 175 and used as output information 285. Although not shown in the figures, the data output unit 254 may also have the function of editing the output information 285 according to the acquired information 284.

[0215] The history acquisition unit 255 creates a new record in the history information 175 each time the communication unit 244 receives measurement information 283 from the communication terminal device 22 (or communication terminal device 23). The unit then stores the time information 276 and the radio wave strength information 277 contained in the measurement information 283 in the newly created record, associating them as time information 176 and radio wave strength information 177, respectively. In this way, the history acquisition unit 255 has the function of acquiring history information 175 by creating history information 175.

[0216] The intensity prediction unit 256 has the function of obtaining predicted radio wave intensity information 178 by predicting the radio wave intensity to be acquired next based on the history information 175, and storing it in the history information 175. The method by which the intensity prediction unit 256 creates the predicted radio wave intensity information 178 will be described later.

[0217] The intensity correction unit 257 has the function of obtaining corrected radio wave strength by correcting the radio wave strength included in the history information 175 according to the predicted radio wave strength, and storing it in the history information 175 as corrected radio wave strength information 179. The method by which the intensity correction unit 257 creates the corrected radio wave strength information 179 will be described later.

[0218] The position identification unit 258 has the function of identifying the position of a moving object and creating position information 180 based on the corrected radio wave intensity information 179 included in the history information 175 and the model information 288.

[0219] In Figure 12, the position identification unit 258 is shown as being included in the intensity prediction unit 256. However, the position identification unit 258 may be provided independently of the intensity prediction unit 256. The method by which the position identification unit 258 identifies the position of the moving object will be described later.

[0220] The model acquisition unit 259 has the function of searching the model database 289 using the environmental condition information 287 as a search key, extracting model candidate information 291 associated with the environmental condition information 287 from the model database 289, and acquiring it as model information 288. In other words, the model information 288 in the second embodiment is not acquired directly by the data acquisition unit 253, but is acquired by the model acquisition unit 259 extracting it from the model database 289 acquired by the data acquisition unit 253.

[0221] The above describes the configuration and functions of the radio wave intensity correction system 20 in the second embodiment. Next, a method for correcting radio wave intensity using the radio wave intensity correction system 20 will be described.

[0222] Figures 14 and 15 are flowcharts illustrating the radio wave intensity correction method in the second embodiment. However, Figures 14 and 15 are flowcharts illustrating the operation of the communication terminal devices 22 and 23 in the radio wave intensity correction method.

[0223] It should be assumed that by the time the processes shown in Figures 14 and 15 begin, the mobile object is positioned at the starting point and the mobile communication terminal device 11 has begun emitting radio waves. Unless otherwise specified, the processes shown in Figures 14 and 15 will be explained using the communication terminal device 22 as an example.

[0224] When the radio wave intensity correction system 20 is put into operation and the power to the communication terminal device 22 is turned on, the communication terminal device 22 sets the measurement continuation flag to "ON" and the target winning flag to "OFF" (step S31).

[0225] The measurement continuation flag is a flag in the communication terminal device 22 that indicates whether or not to continue measuring the radio wave strength by the wireless communication unit 225. When the measurement continuation flag is "ON", the wireless communication unit 225 continues the measurement, and when it is "OFF", the measurement stops. As will be described in detail later, in the radio wave strength correction system 20 of the second embodiment, once the measurement continuation flag is switched to "OFF", the measurement will not be resumed until it is completed.

[0226] Furthermore, the target winning flag is a flag that indicates whether or not the communication terminal device 22 has been identified as a target communication terminal device. When the target winning flag is "ON", it indicates that the communication terminal device 22 has been identified as a target communication terminal device at some point, and when it is "OFF", it indicates that the communication terminal device 22 has not yet been identified as a target communication terminal device. As will be described in detail later, in the radio wave intensity correction system 20 of the second embodiment, once the communication terminal device 22 has been identified as a target communication terminal device, the target winning flag will not be switched to "OFF". Therefore, the target winning flag does not indicate whether or not it is currently a target communication terminal device.

[0227] When the process in step S31 is completed, the CPU 220 determines whether the measurement continuation flag is "ON" or not (step S32).

[0228] In the second embodiment of the radio wave intensity correction system 20, in response to the movement of the moving object, multiple communication terminal devices 22 and 23 sequentially become the target communication terminal device and are responsible for measuring the radio wave intensity. In other words, the target communication terminal device is changed sequentially through a baton pass. Once a communication terminal device 22 has been identified as the target communication terminal device, it will never become the target terminal device again after handing over the role to another communication terminal device 23.

[0229] This is because, in the second embodiment, the path of the moving object is linear and irreversible (it does not move in reverse), so there is no need to assume that the radio wave conditions will improve again after it has ceased to be a target communication terminal device. On the other hand, this also has the effect of preventing the load from increasing if the target communication terminal device is frequently switched in a location where the radio wave conditions are unstable. Therefore, since the communication terminal device 22 that has lost the qualification to be a target communication terminal device no longer needs to continue measuring the radio wave strength, the measurement continuation flag is turned "OFF" and the measurement is stopped thereafter.

[0230] This also reduces the load on the communication terminal devices 22 and 23. The operation of the measurement continuation flag may be selected based on the mobile device's route. For example, it may be controlled by referring to the "route distinction" included in the environmental condition information 287 or the route information 286.

[0231] Therefore, if the measurement continuation flag is "OFF" (No in step S32), the CPU 220 skips other processes and determines whether to terminate all processes (Figure 15: step S47). Whether to terminate all processes can be determined, for example, by whether the moving object has moved to the endpoint position, whether the server device 24 has notified the system of this fact, and whether the notification has been stored as acquired information 281.

[0232] If all processing is to be terminated (Yes in step S47), the CPU 220 resets the measurement continuation flag to "ON" and the target winning flag to "OFF" (step S48). Then, after completing the processing in step S48, the CPU 220 terminates all processing.

[0233] If all processing is not completed in step S47 (No in step S47), the CPU 220 returns to step S32 in Figure 14 and repeats the processing.

[0234] On the other hand, if the measurement continuation flag is "ON" in step S32 (Yes in step S32), the CPU 220 determines whether or not the measurement timing has arrived (step S33).

[0235] If the result in step S33 is "Yes", first, the wireless communication unit 225 measures the radio wave strength in accordance with the control of the CPU 220, obtains the radio wave strength, and transmits it to the CPU 220 (data acquisition unit 250). Next, the data acquisition unit 250 takes the transmitted radio wave strength as radio wave strength information 277 and the time when the radio wave strength was transmitted as time information 276, and associates the two to create measurement information 283. Furthermore, the data acquisition unit 250 stores the created measurement information 283 in the storage device 221 (step S34).

[0236] When measurement information 283 is created, the device identification unit 252 creates output information 282 that includes the measurement information 283. Then, when output information 282 that includes the measurement information 283 is created, the data output unit 251 controls the communication unit 224 to transmit the output information 282 to another communication terminal device 23. As a result, the measurement information 283 stored in step S34 is transmitted as output information 282 to the other communication terminal device 23 (step S35).

[0237] In step S35, the data output unit 251 refers to the target winning flag, and if the target winning flag is "ON", it controls the communication unit 224 to also send the output information 282 to the server device 24. In other words, the measurement information 283 (output information 282) created when the target winning flag is "ON" is sent not only to other communication terminal devices 23 but also to the server device 24. To put it another way, when the target winning flag is switched to "ON", a signal (hereinafter referred to as the "additional notification signal") is transmitted to the data output unit 251 notifying it to add the server device 24 as a destination for sending the measurement information 283.

[0238] As will be explained in more detail later, the measurement information 283 created when the target winning flag is "ON" and sent to the other communication terminal device 23 is used to determine the timing of the handover to the communication terminal device 22. On the other hand, the measurement information 283 created when the target winning flag is "ON" and sent to the server device 24 is stored as history information 175.

[0239] As already explained, once the target winning flag is switched to "ON", it remains that way until the process ends. However, as will be explained in more detail later, the measurement continuation flag is turned "OFF" as appropriate, and the process transitions to a state where it is determined to be "No" in step S32, so step S35 is not executed thereafter.

[0240] If the measurement timing has not yet arrived in step S33 (No in step S33), the CPU 220 skips the processing in steps S34 and S35. Therefore, until the measurement timing arrives, the measurement information 283 is neither created nor transmitted.

[0241] If the result in step S33 is determined to be No, or if the processing in step S35 is completed, the CPU 220 (data acquisition unit 250) determines whether the communication unit 224 has received time information 276 and radio wave strength information 277 (output information 282) (step S36). The radio wave strength information 277 received by the communication unit 224 is information indicating the radio wave strength measured by another communication terminal device 23. Therefore, the processing in step S36 corresponds to the process of determining whether or not the radio wave strength measured by another communication terminal device 23 has been received.

[0242] If the result in step S36 is "Yes", the data acquisition unit 250 stores the time information 276 and the radio wave strength information 277 together as acquired information 281 in the storage device 221 (step S37).

[0243] If the CPU 220 determines No in step S36, it skips step S37. In this case, the acquired information 281, which includes time information 276 and radio wave strength information 277, is not created.

[0244] If the result in step S36 is determined to be No, or if the processing in step S37 is completed, the CPU 220 (device identification unit 252) determines whether both the radio wave strength information 277 included in the measurement information 283 and the radio wave strength information 277 included in the acquisition information 281 exist (Figure 15: step S41).

[0245] If neither is present (No in step S41), the CPU 220 repeats the process from step S47 to wait until both are present.

[0246] If both the radio wave strength information 277 included in the measurement information 283 and the radio wave strength information 277 included in the acquisition information 281 exist (Yes in step S41), the device identification unit 252 compares the radio wave strength information 277 in the measurement information 283 (radio wave strength measured by the own device) with the radio wave strength information 277 in the acquisition information 281 (radio wave strength measured by another device) (step S42).

[0247] The radio wave strength information 277 in the measurement information 283 indicates the radio wave strength measured by the device itself, while the radio wave strength information 277 in the acquired information 281 indicates the radio wave strength measured by another device. Therefore, step S42 corresponds to a process of comparing the radio wave strength measured by the device itself with the radio wave strength measured by another device. In other words, the device identification unit 252 can compare the radio wave strength measured by multiple communication terminal devices 22 and 23.

[0248] When step S42 is executed, the device identification unit 252 determines whether the radio wave intensity information 277 of the measurement information 283 is greater than or equal to (step S43).

[0249] If the radio wave strength information 277 included in the measurement information 283 is greater, it means that the radio wave strength measured by the device itself is greater. In other words, it can be determined that the device itself is a more suitable device to be the target communication terminal device (the communication terminal device that measures the radio wave strength stored in the history information 175) compared to other devices. Therefore, if the device identification unit 252 determines Yes in step S43, it switches the target winning flag to "ON" (step S44).

[0250] As a result, the device identification unit 252 identifies the communication terminal device 22 as the target communication terminal device. When the target winning flag is set to "ON" in step S44, an additional notification signal is transmitted to the data output unit 251, and when output information 282 including the measurement information 283 is created, it is also sent to the server device 24. After step S44 is executed, the CPU 220 repeats the processing from step S47, which has already been described.

[0251] If the result in step S43 is No, it means that another communication terminal device 23 has been identified as more suitable for the target communication terminal device. Therefore, the device identification unit 252 determines whether the target winning flag is "ON" or not (step S45).

[0252] If the target winning flag is "ON" and the user's own unit has already been identified as the target communication terminal device (Yes in step S45), the device identification unit 252 determines that the user's own unit has relinquished the target communication terminal device to another unit and switches the measurement continuation flag to "OFF" (step S46).

[0253] As a result, the device switches to a state where it no longer measures radio wave strength. When step S46 is executed, the CPU 220 repeats the process from step S47, which was previously explained.

[0254] On the other hand, if the target winning flag is still "OFF" in step S45 (No in step S45), it is determined that the device is still waiting to be identified as the target communication terminal device (the device on the starting point side of the path is the target communication terminal device), and the process in step S46 is skipped, and the process from step S47, which has already been explained, is repeated.

[0255] To briefly explain the processes shown in Figures 14 and 15, immediately after the start, neither communication terminal device 22 nor 23 is identified as the target communication terminal device, and both perform radio wave strength measurements. In this state, the server device 24 cannot receive radio wave strength information 277 from either device. However, once the measured radio wave strengths are transmitted to each other and compared, one of the communication terminal devices 22 or 23 is identified as the target terminal device.

[0256] In the second embodiment of the radio wave intensity correction system 20, when the moving object is at the starting position (start), the radio wave intensity measured by the communication terminal device 22 that is closer to the moving object is greater. Therefore, the communication terminal device 22 is first identified as the target communication terminal device.

[0257] While this state continues, both communication terminal devices 22 and 23 perform radio wave strength measurement and transmission to other communication terminal devices, and in step S42, the radio wave strength information is compared.

[0258] Further, while the communication terminal device 22 is the target communication terminal device, step S44 continues to be executed in the communication terminal device 22, so that the measurement information 283 is also transmitted to the server device 24 in step S35. On the other hand, step S44 is never executed in the communication terminal device 23, so no additional notification signal is transmitted, and the measurement information 283 is not transmitted to the server device 24 in step S35.

[0259] When the moving body moves and the communication terminal device 23 becomes closer to the moving body, the radio field intensity measured by the communication terminal device 23 becomes larger, and a No determination is made in step S43 in the communication terminal device 22. As a result, steps S45 and S46 are executed in the communication terminal device 22, and the measurement continuation flag is set to "OFF". On the other hand, in the communication terminal device 23, a Yes determination is made for the first time in step S43. As a result, the target winning flag is switched to "ON", and the communication terminal device 23 is identified as the target communication terminal device.

[0260] When the communication terminal device 23 becomes the target communication terminal device, the communication terminal device 22 does not perform radio field intensity measurement. In the communication terminal device 22, the target winning flag remains "ON", but since the measurement information 283 is not generated, the radio field intensity information 277 is not transmitted from the communication terminal device 22 to the server device 24. In addition, since the radio field intensity information 277 is not measured in the communication terminal device 22, the radio field intensity is not compared between the two devices. Since the radio field intensity comparison is not performed, the target communication terminal device will not be switched thereafter.

[0261] The above is the description of the operations of the communication terminal devices 22 and 23 that implement the radio field intensity correction method according to the second embodiment. Next, the operation of the server device 24 in the radio field intensity correction method will be described.

[0262] Figure 16 is a flowchart showing the operation of the server device 24 according to the second embodiment. Note that Figure 16 shows the operation of the server device 24 up to the start of operation of the radio field intensity correction system 20.

[0263] When the process shown in Figure 16 begins, the server device 24 acquires the model database 289 (step S51). For example, the communication unit 244 of the server device 24 acquires the model database 289 by downloading it via the network 92. The communication unit 244 transmits the acquired model database 289 to the CPU 240 (data acquisition unit 253). The data acquisition unit 253 stores the model database 289 as acquired information 284 in the storage device 241.

[0264] Next, the server device 24 acquires route information 286 (step S52). For example, in step S52, the operator of the server device 24 operates the operation unit 242 to input route information 286. The operation unit 242 transmits the input route information 286 to the CPU 240 (data acquisition unit 253). The data acquisition unit 253 stores the route information 286 as acquired information 284 in the storage device 241.

[0265] As previously explained, the route information 286 in the second embodiment includes starting position information indicating the position of the mobile object at the time when wireless communication between the communication terminal devices 22, 23 and the mobile communication terminal device 11 is initiated (when movement is initiated), and ending position information indicating the position of the mobile object at the time when wireless communication between the communication terminal devices 22, 23 and the mobile communication terminal device 11 is terminated (when movement is terminated).

[0266] In the second embodiment, the data acquisition unit 253, if necessary, determines the positions (paths) that the moving object can take through movement based on the previously acquired path information 286, and sets these as new path information 286.

[0267] Figure 17 illustrates the positional relationship between the mobile body (mobile communication terminal device 11) and the communication terminal device 22 in the second embodiment. The closest position shown in Figure 17 is the position of the mobile body when the distance between the mobile body and the communication terminal device 22 (terminal distance CD) is the shortest. The terminal distance CD at that time is the shortest terminal distance.

[0268] In the second embodiment, the moving object moves linearly from the starting position to the ending position without reversing direction. Therefore, the position that the moving object can take through movement is the trajectory of the moving object when it reaches the ending position, which in the second embodiment is a straight line as shown by the thick line in Figure 17. In other words, when the positions of two points are given as path information 286, the data acquisition unit 253 estimates that the straight line connecting the two points is the path of the moving object.

[0269] Thus, the data acquisition unit 253 in the second embodiment has the function of acquiring route information 286. Therefore, the radio wave intensity correction system 20 in the second embodiment is more versatile because the route of the moving object is not limited.

[0270] Furthermore, the data acquisition unit 253 has the function of approximately determining a route based on the route information 286 acquired in step S52 and acquiring it as new route information 286. Therefore, the radio wave intensity correction system 20 in the second embodiment can appropriately correct the radio wave intensity even with simple route information 286. Note that if the route information 286 acquired in step S52 is already information indicating the movement trajectory of a moving object, the data acquisition unit 253 does not need to estimate the route information 286.

[0271] Figure 18 shows the relationship between the terminal distance and the route exemplified in Figure 17. Figure 18 shows that, along the route shown in Figure 17, the terminal distance CD decreases as the moving object moves from the starting point to the closest point, indicating that the moving object approaches the communication terminal device 22 during this section. Such a section is referred to as the "proximity section" on the route, as shown in Figure 17.

[0272] On the other hand, in the section from the closest point to the endpoint along the path shown in Figure 17, the terminal distance CD increases as the moving object moves, and it can be seen that the moving object moves away from the communication terminal device 22 in this section. Such a section is called a "separation section" on the path, as shown in Figure 17.

[0273] If route information 286 can be obtained, the correlation between the distance traveled along the route and the terminal distance CD can be obtained, as shown in Figure 18. In the second embodiment, a straight route is assumed, but even with a route that curves or bends, the relationship shown in Figure 18 can be obtained, as long as the approaching and separating sections are arranged in a complex manner.

[0274] Returning to Figure 16, once route information 286 is acquired, the server device 24 acquires environmental condition information 287 (step S53). For example, in step S53, the operator of the server device 24 operates the operation unit 242 to input environmental condition information 287. The operator assumes the environmental condition information 290 stored in the model database 289 and inputs the current environmental conditions of the route as environmental condition information 287. The operation unit 242 transmits the environmental condition information 287 input by the operator to the CPU 240 (data acquisition unit 253). The data acquisition unit 253 stores the environmental condition information 287 as acquired information 284 in the storage device 241.

[0275] Furthermore, if the environmental condition information 287 includes "distinction of route information 286", information identifying the route information 286 obtained in step S52 (for example, a route identifier) ​​may be stored in the environmental condition information 287 as "distinction of route information 286".

[0276] When the processing in step S53 is completed, the server device 24 acquires model information 288 (step S54). The model acquisition unit 259 searches the model database 289 according to the environmental condition information 287 and determines model information 288 from multiple model candidate information 291 stored in the model database 289.

[0277] For example, if the environmental condition information 287 obtained in step S53 is "sunny" as a weather classification, searching the model database 289 using the environmental condition information 287 as a search key will determine and obtain model candidate information A (model candidate information 291) which has "sunny" stored as environmental condition information 290, as model information 288.

[0278] Model information 288 (model candidate information 291) is information that shows the relationship between the distance between the communication terminal devices 22, 23 and the mobile communication terminal device 11 (terminal distance CD) and the radio wave strength. As will be described in detail later, the strength prediction unit 256 in the second embodiment acquires the predicted radio wave strength based on the model information 288.

[0279] In the first embodiment, the intensity prediction unit 153 was described as acquiring predicted radio wave intensity based on Equation 1. However, the actual environment when a moving object is in motion may include factors that cannot be fully expressed by Equation 1. On the other hand, by using model information 288 that reflects actual environmental conditions, the radio wave intensity correction system 20 in the second embodiment can respond to more appropriate environmental conditions and improve the accuracy of the correlation between terminal distance CD and radio wave intensity. Therefore, the radio wave intensity correction system 20 improves the accuracy of radio wave intensity prediction.

[0280] In particular, the radio wave intensity correction system 20 in the second embodiment acquires multiple model candidate information 291 and obtains more appropriate model information 288 based on environmental condition information 287. This further improves the accuracy of the predicted radio wave intensity by selecting appropriate environmental condition information 287.

[0281] When step S54 is executed, the server device 24 (radio wave intensity correction system 20) starts operation. Alternatively, after step S54 is completed, the system may be configured so that an operator can operate the control unit 242 to instruct the system to start operation. Furthermore, when operation starts, the server device 24 may transmit output information 285 indicating the start of operation to the communication terminal devices 22 and 23.

[0282] FIG. 19 is a flowchart showing the operation of the operational state of the server device 24 in the second embodiment. It is assumed that before the processing shown in FIG. 19 is started, a program 811 is stored in the mobile communication terminal device 11, and a program 822 is stored in the communication terminal devices 22 and 23. It is also assumed that a program 824 is stored in the server device 24, and the processing shown in FIG. 16 has been completed. It is further assumed that the transmission of radio waves from the mobile communication terminal device 11 has already been started. Furthermore, the mobile object is already arranged at the start point position, and starts moving after the processing shown in FIG. 19 is started.

[0283] When the radio wave intensity correction system 20 (server device 24) is in the operational state, it constantly monitors whether the communication unit 244 has received time information 276 and radio wave intensity information 277 (step S61), and whether history information 175 has been created (step S64).

[0284] In the operational state of the radio wave intensity correction system 20, when candidate communication terminal devices (communication terminal devices 22, 23) are specified, output information 285 including time information 276 and radio wave intensity information 277 is transmitted from the candidate communication terminal devices to the server device 24.

[0285] When the communication unit 244 receives such output information 282, the CPU 240 determines Yes in step S61.

[0286] When it is determined Yes in step S61, the CPU 240 (data acquisition unit 253) acquires the time information 276 and radio wave intensity information 277 included in the output information 282 (step S62).

[0287] When step S62 is executed and the time information 276 and radio wave intensity information 277 are acquired, the data acquisition unit 253 creates a new record in the history information 175 (step S63), and stores the time information 276 and radio wave intensity information 277 acquired in step S62 in the record as time information 176 and radio wave intensity information 177.

[0288] When the processing in step S63 is completed, the radio wave intensity correction system 20 (server device 24) returns to the operational state. That is, it returns to the state of monitoring whether the communication unit 244 has received the time information 276 and the radio wave intensity information 277 (step S61) and whether the history information 175 has been created (step S64).

[0289] In the operational state, when a new record of history information 175 is created, the radio wave intensity correction system 20 (CPU 240) determines Yes in step S64. The processing in step S64 can be performed, for example, in the same way as in step S4.

[0290] In the following description of steps S65 and S66, the record of history information 175 that was determined to be a newly created record in step S64 may be referred to as the "record to be processed," as in the first embodiment. Also, in steps S65 and S66, the time information 176 stored in the record to be processed is considered to be the current time (time T).

[0291] If the result in step S64 is determined to be Yes, the intensity correction unit 257 performs radio wave intensity correction processing (step S65).

[0292] Figure 20 is a flowchart showing the radio wave intensity correction process in the second embodiment.

[0293] When the radio wave intensity correction process is started, the intensity correction unit 257 acquires the radio wave intensity information 177 stored in the record to be processed as the radio wave intensity to be corrected (step S71).

[0294] Next, the intensity correction unit 257 determines whether the record to be processed is the first record (step S72). The process in step S72 can be performed, for example, in the same way as in step S12.

[0295] In the second embodiment as well, at the time the first record is created, the moving object has not yet started moving and is considered to be stationary at the starting position. Therefore, even in the radio wave intensity correction system 20, at the time the first record is created, any conditions such as multipath are considered to have a negligible impact. Thus, the reliability of the measured radio wave intensity is considered high.

[0296] In other words, if the record to be processed is the first record (Yes in step S72), the intensity correction unit 257 assumes that it does not need to correct the acquired radio wave intensity to be corrected. Therefore, the intensity correction unit 257 acquires the corrected radio wave intensity information 179 as the radio wave intensity to be corrected as is (step S73).

[0297] It should be noted that the communication terminal device 23 is not necessarily able to observe the moving object at the starting point (mobile communication terminal device 11). In the second embodiment, as shown in Figure 8, the radio wave intensity correction system 20 has the communication terminal device 22 positioned at the starting point. Therefore, when the first record of history information 175 is created in the server device 24, the candidate communication terminal device is the communication terminal device 22, and the first record is always created based on the measurement information 283 received from the communication terminal device 22. When the communication terminal device 23 becomes a candidate communication terminal device, the first record has already been created in the server device 24. Therefore, it is not a problem that the communication terminal device 23 cannot observe the moving object at the starting point.

[0298] When step S73 is executed and the corrected radio wave intensity information 179 is acquired, the intensity correction unit 257 stores the acquired corrected radio wave intensity information 179 in the processing target record of the history information 175 (step S79).

[0299] When step S79 is executed, the radio wave intensity correction system 20 in the second embodiment finishes the radio wave intensity correction process (step S65) and returns to the process shown in Figure 19.

[0300] On the other hand, if step S72 determines No (i.e., the record to be processed is not the first record), the intensity correction unit 257 refers to the history information 175 and obtains the predicted radio wave intensity information 178 and radio wave intensity information 177 stored in the record immediately preceding the record to be processed (the comparison record) (step S74). Note that if the time information 176 of the record to be processed is "time T", then the time information 176 of the comparison record, which is the immediately preceding record, is "time (Ti)".

[0301] The predicted signal strength information 178 stored in the comparison record is information that predicted the signal strength to be measured this time at the time of the previous measurement. In other words, the predicted signal strength information 178 obtained in step S74 is information that predicts the signal strength information 177 of the record to be processed.

[0302] When the processing in step S74 is completed, the intensity correction unit 257 calculates the amount of change in radio wave intensity during time i based on the corrected radio wave intensity information 179 of the comparison record (a value obtained by correcting the radio wave intensity measured at time (Ti)) and the radio wave intensity information 177 of the processing record (a radio wave intensity measured at time T) (step S75).

[0303] Next, the intensity correction unit 257 determines whether the amount of change obtained in step S75 is appropriate (step S76). In the first embodiment, the path consisted only of separation sections (it was necessary to arrange the communication terminal device 12 so that it consisted only of separation sections). Therefore, it was possible to determine whether the measured radio wave intensity was appropriate simply by determining whether the radio wave intensity had increased compared to the past. However, as shown in Figures 17 and 18, in the second embodiment, the path includes not only separation sections but also approach sections. In other words, the radio wave intensity correction system 20 in the second embodiment is designed to handle paths in which separation sections and approach sections are mixed.

[0304] Therefore, in the second embodiment, the intensity correction unit 257 determines whether the radio wave intensity has increased further if the current position of the moving object is in a separated section of the path, and determines that it is inappropriate if the radio wave intensity has increased despite being in a separated section. In other words, the radio wave intensity measured this time (radio wave intensity information 177 of the record to be processed) is considered unreliable and inappropriate. In such cases, the intensity correction unit 257 determines No in step S76.

[0305] Furthermore, the intensity correction unit 257 determines whether the radio wave intensity has decreased further if the current position of the moving object is within the approach section of the path. If it has decreased despite being within the approach section, it determines that it is inappropriate. In other words, the radio wave intensity measured this time (radio wave intensity information 177 of the record to be processed) is considered unreliable and inappropriate. In such cases, the intensity correction unit 257 also determines No in step S76.

[0306] If the amount of change is inappropriate (No in step S76), the intensity correction unit 257 considers the radio wave intensity information 177 of the record to be processed to be unreliable and discards it, and obtains corrected radio wave intensity information 179 as the corrected radio wave intensity of the comparison record (step S78). In other words, the current radio wave intensity is corrected to the predicted radio wave intensity.

[0307] When step S78 is executed and the corrected radio wave intensity information 179 is acquired, the intensity correction unit 257 stores the acquired corrected radio wave intensity information 179 in the processing target record of the history information 175, just as when step S73 was executed (step S79).

[0308] As already explained, when step S79 is executed, the radio wave intensity correction system 20 in the second embodiment terminates the radio wave intensity correction process (step S65) and returns to the process shown in Figure 19.

[0309] Returning to the process in step S76, if the amount of change is appropriate (Yes in step S76), the intensity correction unit 257 determines whether the radio wave intensity information 177 of the record to be processed is within the range, according to the predicted radio wave intensity information 178 of the comparison record acquired in step S74 (step S77). Note that the process in step S77 can be performed in the same way as in step S17.

[0310] If the result in step S77 is "Yes", the intensity correction unit 257 determines that the radio wave intensity information 177 of the record to be processed is reliable and executes step S73. That is, as already explained, the corrected radio wave intensity information 179 is obtained using the radio wave intensity (radio wave intensity information 177 of the record to be processed) obtained in step S71 as the corrected radio wave intensity.

[0311] However, if step S77 determines No, the intensity correction unit 257 determines that the radio wave intensity information 177 of the record to be processed is unreliable and executes step S78, which has already been described.

[0312] In the second embodiment of the radio wave intensity correction system 20, the execution of step S78 corresponds to a correction being performed in which the unreliable radio wave intensity (measured value) is rewritten with the predicted radio wave intensity (predicted value). However, the correction method is not limited to this. For example, a correction value may be calculated by weighting according to the value of the deviation from the predicted radio wave intensity (prediction error Q), and the correction may be performed by adding this correction value to the radio wave intensity.

[0313] Thus, in the second embodiment, the intensity correction unit 257 corrects the radio wave intensity information 177 included in the history information 175 according to the predicted radio wave intensity information 178 to obtain corrected radio wave intensity information 179, and stores it in the history information 175. Therefore, for example, by creating predicted radio wave intensity information 178 that suppresses the influence of events other than the terminal distance CD between the mobile communication terminal device 11 and the communication terminal devices 22, 23, the influence of events other than the terminal distance CD between the mobile communication terminal device 11 and the communication terminal devices 22, 23 on the radio wave intensity information 177 can be suppressed.

[0314] Once step S73 or step S78 is executed, as already explained, step S79 is executed to terminate the radio wave intensity correction process (step S65) and return to the process shown in Figure 19.

[0315] Once the process in step S65 shown in Figure 19 is completed, the radio wave intensity correction system 20 (CPU 240) performs radio wave intensity prediction processing (step S66).

[0316] Figure 21 is a flowchart showing the radio wave intensity prediction process in the second embodiment. When the radio wave intensity prediction process is started, the intensity prediction unit 256 acquires the corrected radio wave intensity information 179 stored in the newly created record (processing target record) identified in step S64 (step S80).

[0317] In the radio wave intensity correction system 20 of the second embodiment, when the radio wave intensity prediction process (step S66) is executed, step S65 (step S79) has already been executed, and the corrected radio wave intensity information 179 has already been stored in the record to be processed. Therefore, at the time step S80 is executed, the intensity prediction unit 256 can acquire the corrected radio wave intensity information 179 stored in the record to be processed.

[0318] Next, the intensity prediction unit 256 determines whether the record to be processed is the first record (step S81). The process in step S81 can be performed, for example, in the same way as the process in step S72.

[0319] At the time the first record is created, the moving object has not yet started moving and is considered to be stationary at the starting point. Therefore, if the record to be processed is the first record (Yes in step S81), the position identification unit 258 obtains position information 180 using the starting point position information stored in the route information 286 as the position of the moving object. Then, the intensity prediction unit 256 stores the position information 180 in the record to be processed in the history information 175 (step S82).

[0320] Furthermore, in the second embodiment as well, the moving object is considered to be stationary when the first record is created. And it is predicted that the intensity of the radio waves from the stationary mobile communication terminal device 11 will not change. Therefore, the intensity prediction unit 256 predicts that the corrected radio wave intensity of the record to be processed (in this case, the first record) will be the radio wave intensity to be measured next. That is, the intensity prediction unit 256 acquires predicted radio wave intensity information 178 using the corrected radio wave intensity of the record to be processed as the predicted radio wave intensity (step S83).

[0321] When step S83 is executed and the predicted radio wave intensity information 178 is acquired, the intensity prediction unit 256 stores the acquired predicted radio wave intensity information 178 in the processing target record of the history information 175 (step S89).

[0322] As a result, in the second embodiment as well, the first record of the history information 175 stores the same value in the radio wave strength information 177, the predicted radio wave strength information 178, and the corrected radio wave strength information 179.

[0323] When step S89 is executed, the radio wave intensity correction system 20 in the second embodiment terminates the radio wave intensity prediction process (step S66) and returns to the process shown in Figure 19.

[0324] On the other hand, if it is determined to be No in step S81 (if the record to be processed is not the first record), the location identification unit 258 in the second embodiment acquires the location PO(T) and stores it in the history information 175 as location information 180 (step S84).

[0325] The process of step S84 will now be explained in detail. First, the positioning unit 258 determines the terminal distance CD using the model information 288 based on the acquired corrected radio wave strength information 179. In the second embodiment, the model information 288 is information that shows the relationship between the terminal distance CD and the radio wave strength. Therefore, in the second embodiment, the positioning unit 258 can determine the current terminal distance CD(T) using the model information 288 based on the corrected radio wave strength information 179 (which can be considered as the radio wave strength at time T). By using the model information 288 in this way, the terminal distance CD(T) can be determined with high accuracy while conforming to environmental conditions and suppressing the effects of multipath and other factors.

[0326] Once the terminal distance CD(T) is determined, the distance traveled along the path to date can be determined using the relationship between the terminal distance CD and the distance traveled along the path shown in Figure 18, and the position PO(T) can be determined. In this way, the position identification unit 258 can execute the process in step S84. In the second embodiment, there may be multiple points along the path with the same terminal distance CD (such a path is assumed; see Figure 18). However, although the details are omitted, it is possible to determine which of these locations is appropriate as the current position from the movement history of the moving object up to the present (for example, past position information 180).

[0327] Once the current position is stored in step S84, the intensity prediction unit 256 executes steps S85 to S87. Note that the processing in steps S85 to S87 can be performed in the same way as steps S25 to S27 shown in Figure 7.

[0328] In the second embodiment as well, the measurement interval (time i) is constant, so in the same way as in the first embodiment, the predicted travel distance fmd(T+i) in step S87 is obtained as the nearest travel distance md(T).

[0329] Once the predicted travel distance fmd(T+i) is determined, the position identification unit 258 identifies the predicted position PO(T+i) of the moving object as the position obtained by moving the object along the path by the predicted travel distance fmd(T+i) from the current position PO(T). Then, once the predicted position PO(T+i) of the moving object is determined, the distance between the two points (terminal distance CD(T+i)) is calculated based on the position of the target communication terminal device and the predicted position PO(T+i).

[0330] Based on the predicted next terminal distance CD(T+i) and model information 288, the intensity prediction unit 256 determines the predicted next radio wave intensity as Lb(T+i) and obtains predicted radio wave intensity information 178 (step S88).

[0331] When step S88 is executed and the predicted radio wave intensity information 178 is acquired, the intensity prediction unit 256 stores the acquired predicted radio wave intensity information 178 in the processing target record of the history information 175 (step S89).

[0332] As already explained, when step S89 is executed, the radio wave intensity correction system 20 in the second embodiment terminates the radio wave intensity prediction process (step S66) and returns to the process shown in Figure 19.

[0333] After completing step S66 and returning to Figure 19, the radio wave intensity correction system 20 determines whether to terminate (step S67). Step S67 can be achieved, for example, by determining whether the position information 180 stored in step S84 is the endpoint. Since the moving object does not move after arriving at the endpoint, the radio wave intensity correction system 20 can terminate its operation.

[0334] If the result in step S67 is No, the radio wave intensity correction system 20 returns to the operational state. On the other hand, if the result in step S67 is Yes, the radio wave intensity correction system 20 notifies the communication terminal devices 22 and 23 of this fact and then terminates the process.

[0335] As described above, the same effects as those of the radio wave intensity correction system 10 in the first embodiment can be obtained in the radio wave intensity correction system 20 in the second embodiment.

[0336] Furthermore, the system includes a data acquisition unit 253 (route acquisition unit) that acquires route information 286 indicating the path of a moving object, and the intensity prediction unit 256 acquires predicted radio wave intensity information 178 based on the route information 286. As a result, the route is not limited, thus improving versatility.

[0337] Furthermore, the route information 286 includes starting position information indicating the position of the mobile body when wireless communication between the communication terminal devices 22, 23 and the mobile communication terminal device 11 is initiated, and ending position information indicating the position of the mobile body when wireless communication between the communication terminal devices 22, 23 and the mobile communication terminal device 11 is terminated. The data acquisition unit 253 approximately determines the route of the mobile body based on the starting position information and the ending position information, and the intensity prediction unit 256 acquires predicted radio wave intensity information 178 based on the approximately determined route. This makes it possible to acquire route information even if detailed route information is not provided.

[0338] Furthermore, the system includes a model acquisition unit 259 that acquires model information 288 showing the relationship between the terminal distance CD between the communication terminal devices 22, 23 and the mobile communication terminal device 11 and the radio wave intensity. The intensity prediction unit 256 acquires predicted radio wave intensity information 178 based on the model information 288. This improves versatility because it does not limit environmental conditions.

[0339] Furthermore, the model acquisition unit 259 acquires multiple model candidate information 291 (model database 289) associated with the environmental condition information 290, and determines model information 288 from the multiple model candidate information 291 according to the environmental condition information 287. This allows the model information 288 to be switched by selecting the appropriate environmental conditions, thereby improving the accuracy of the predicted radio wave intensity.

[0340] Furthermore, the environmental conditions information 287 includes at least one of the following: day of the week, time, weather, region, season, indoor / outdoor distinction, type of mobile object, surrounding environment of the mobile object, and path distinction. This allows for correction of the radio wave strength by considering various factors that affect the correlation between terminal distance CD and radio wave strength, thereby improving accuracy.

[0341] Furthermore, the device identification unit 252 compares the radio wave strength between multiple communication terminal devices 22, 23 and the mobile communication terminal device 11 to identify the target communication terminal device from among the multiple communication terminal devices. The strength prediction unit 256 obtains the predicted radio wave strength between the target communication terminal device and the mobile communication terminal device 11, and the strength correction unit 257 obtains the corrected radio wave strength between the target communication terminal device and the mobile communication terminal device 11. This improves accuracy, for example, by selecting the communication terminal device with the strongest radio wave strength.

[0342] Furthermore, the system includes a server device 24 capable of data communication with the communication terminal devices 22 and 23, and the intensity correction unit 257 is located in the server device 24. This allows the server device 24, which has relatively high computing power, to perform computationally intensive tasks. Also, since only one server device 24 is needed within the radio wave intensity correction system 20, the overall cost can be reduced when installing a large number of communication terminal devices 22 and 23. However, the number of server devices 24 is not limited to one.

[0343] In the second embodiment, the communication terminal device 22 communicates with the communication terminal device 23 via the network 92. However, since both the communication terminal device 22 and the communication terminal device 23 are equipped with wireless communication capabilities, the communication terminal device 22 may communicate with the communication terminal device 23 wirelessly.

[0344] Furthermore, in the second embodiment, the communication terminal devices 22 and 23 were described as continuing to wait until step S41 was answered with Yes. This means that both communication terminal devices 22 and 23 must be able to communicate wirelessly with the mobile communication terminal device 11 at the starting position. For example, if a communication terminal device 23 that is far from the starting position cannot communicate wirelessly with the mobile communication terminal device 11 at the starting position, then no matter how long the communication terminal device 22 waits, the output information 282 from the communication terminal device 23 will not be received. Therefore, it is preferable that the communication terminal device 22 (device identification unit 252) measures the waiting time since the first measurement information 283 was created, and if time information 276 and radio wave strength information 277 from the communication terminal device 23 are not received even after a predetermined time has elapsed, it is forcibly determined to Yes in step S41 and executed in step S44.

[0345] <3. Third Embodiment> The method for estimating the position of a moving object is not limited to the methods shown in the first and second embodiments. For example, it is also possible to estimate the position of a moving object using a particle filter.

[0346] Figure 22 shows the radio wave intensity correction system 30 in the third embodiment. The radio wave intensity correction system 30 in the third embodiment differs from the radio wave intensity correction system 10 in the first embodiment in that it includes multiple communication terminal devices 32, 33 instead of the communication terminal device 12. In the following description, the same reference numerals are used for components of the radio wave intensity correction system 30 in the third embodiment as in the radio wave intensity correction system 10 in the first embodiment, and their descriptions are omitted as appropriate. Note that the number of communication terminal devices 32, 33 is not limited to two.

[0347] Furthermore, in the third embodiment, for the sake of simplicity, the path of the moving object will be described using the same simple path as in the first embodiment as an example. Therefore, the information corresponding to the path information 286 in the second embodiment will not be used and will be omitted. Similarly, the information corresponding to the environmental condition information 287, model information 288, and model database 289 in the second embodiment will also be described using an example where these are not used. However, the radio wave intensity correction system 30 in the third embodiment can also be designed to use these.

[0348] Furthermore, communication terminal devices 32 and 33 are devices located at different positions from each other. However, for the sake of simplicity, it is assumed that both communication terminal devices 32 and 33 are located near the path to such an extent that they can be considered to be on the path, and that their absolute positions are given. In particular, it is assumed that communication terminal device 32 is located at a position that can be considered the starting point.

[0349] Figure 23 is a block diagram showing the communication terminal device 32 in the third embodiment. Since the communication terminal device 32 in the third embodiment has the same configuration as the communication terminal device 33, the description of the communication terminal device 33 will be omitted in the following description unless otherwise specified. However, the communication terminal device 32 and the communication terminal device 33 are not necessarily limited to being completely identical devices.

[0350] The communication terminal device 32 comprises a CPU 120, a storage device 121, an operation unit 122, a display unit 123, and a wireless communication unit 125. In other words, the communication terminal device 32 has the same hardware configuration as the communication terminal device 12 in the first embodiment. Therefore, the description of the configuration of the communication terminal device 32 that is equivalent to that of the communication terminal device 12 in the first embodiment will be omitted as appropriate. However, the communication terminal device 32 and the communication terminal device 12 are not limited to being completely identical devices.

[0351] The CPU 120 in the third embodiment differs from the CPU 120 in the first embodiment in that it reads and executes the program 832 stored in the storage device 121.

[0352] The storage device 121 in the third embodiment stores history information 175, acquisition information 181, and output information 182, similar to the storage device 121 in the first embodiment. On the other hand, the storage device 121 in the third embodiment differs from the storage device 121 in the first embodiment in that it stores program 832, function database 370, operating condition information 371, initial distribution information 372, likelihood function information 373, first provisional position information 374, and second provisional position information 375.

[0353] The history information 175 shown in Figure 23 is equivalent to the history information 175 in the first embodiment. Therefore, although not shown in Figure 23, the history information 175 in the third embodiment includes time information 176, radio wave strength information 177, predicted radio wave strength information 178, corrected radio wave strength information 179, and location information 180. However, the history information 175 differs from the history information 175 in the first embodiment in that it includes not only location information 180 but also location information 380.

[0354] In the third embodiment, the location information 380 is the same as the location information 180 in the first embodiment, indicating the position of the moving object. However, the location information 380 in the third embodiment differs in that it is identified based on the first provisional location information 374 and the second provisional location information 375.

[0355] Figure 24 shows the structure of the function database 370 in the third embodiment. The function database 370 is a database with a table structure in which one record is created for each operating condition information 376.

[0356] As shown in Figure 24, the function database 370 is configured to store a record number, operating condition information 376, and likelihood function candidate information 377 in relation to each other in a single record.

[0357] Operating condition information 376 is information that is compared with operating condition information 371 when the function database 370 is searched.

[0358] The likelihood function candidate information 377 is candidate information for the likelihood function information 373, and it is information that shows the likelihood function for calculating the weight of each particle when determining the position of a moving object using a particle filter. The likelihood function candidate information 377 is associated with the operating condition information 376, and it is information that has been adjusted to improve the position estimation accuracy when the operating conditions shown in the associated operating condition information 376 are met.

[0359] For example, the likelihood function candidate information E (likelihood function candidate information 377), which is associated with "sunny" as the operating condition information 376, is adjusted so that the accuracy of position determination by the position determination unit 355 is higher when the weather is "sunny".

[0360] The likelihood function candidate information 377 is not necessarily associated with a single operating condition. In other words, the operating condition information 376 does not necessarily include only one environmental condition. For example, the likelihood function candidate information H shown in Figure 24 is associated with "outdoors" and "vehicle".

[0361] Returning to Figure 23, the operating conditions information 371 is information indicating the operating conditions when the radio wave intensity correction system 30 is in operation. The operating conditions information 371 includes at least one of the following: day of the week, time, weather, region, season, indoor / outdoor distinction, type of mobile object, surrounding environment of the mobile object, and path distinction. As will be described in detail later, the operating conditions information 371 is information used as a search key for searching the function database 370.

[0362] The initial distribution information 372 is information that indicates how each particle should be distributed in advance (in the initial state) across the state space when the position of a moving object is determined using a particle filter. In the third embodiment, the initial distribution information 372 is set to a distribution in which particles are biased towards the vicinity of the starting position of the moving object. As a result, the radio wave intensity correction system 30 can start calculations from predicted samples corresponding to the initial state of the moving object, thus improving accuracy compared to using a general uniform distribution.

[0363] Likelihood function information 373, similar to the likelihood function candidate information 377, is information that indicates the likelihood function used to calculate the weight of each particle when determining the position of a moving object using a particle filter. By acquiring such likelihood function information 373, the data acquisition unit 350 in the third embodiment also functions as a likelihood function acquisition unit.

[0364] The first provisional location information 374 is information calculated and created in the communication terminal device 32, and is information that associates time with the provisional location of the moving object at that time.

[0365] The second provisional location information 375 is information transmitted to the communication terminal device 32 and received by the wireless communication unit 125, and is calculated and created by another communication terminal device 33. Similar to the first provisional location information 374, the second provisional location information 375 is information that associates time with the provisional location of the moving object at that time.

[0366] As will be described in more detail later, the radio wave intensity correction system 30 identifies provisional locations (first provisional location information 374 and second provisional location information 375) for each of the communication terminal devices 32 and 33, and then compares the provisional locations identified for each to determine the location of the moving object (location information 380).

[0367] In the third embodiment, the operation unit 122 is hardware operated by an operator to input instructions to the communication terminal device 32, similar to the operation unit 122 in the first embodiment. The information input in this manner is transmitted to the CPU 120 and temporarily stored in the storage device 121 as acquired information 181. Such information may include a function database 370, operating condition information 371, initial distribution information 372, and likelihood function information 373. However, not all of this information must be input from the operation unit 122. Furthermore, the information input by the operation unit 122 in the communication terminal device 32 may be received by the communication terminal device 33 via the wireless communication unit 125. In other words, the information does not have to be acquired in the same way in the communication terminal device 32 and the communication terminal device 33.

[0368] The wireless communication unit 125 provides the communication terminal device 32 with the function of wirelessly communicating with external devices (mobile communication terminal device 11 and other communication terminal devices 33). As a result, in the third embodiment, the communication terminal device 32 performs wireless communication with the mobile communication terminal device 11 and other communication terminal devices 33 in accordance with the Wi-Fi HaLow standard.

[0369] In particular, the second provisional location information 375 received by the wireless communication unit 125 from another communication terminal device 33 in the third embodiment is transmitted to the CPU 120 and stored in the storage device 121. On the other hand, the first provisional location information 374 created by the communication terminal device 32 is transmitted from the CPU 120 to the wireless communication unit 125 in the third embodiment and transmitted to the other communication terminal device 33.

[0370] In this way, communication terminal devices 32 and 33 will send and receive information about their respective provisional locations.

[0371] Furthermore, the wireless communication unit 125 also has the function of measuring the strength of radio waves transmitted from the mobile communication terminal device 11 and transmitting this information to the CPU 120, similar to the first embodiment. The wireless communication unit 125 also measures the strength of radio waves at predetermined time intervals i and transmits this information to the CPU 120, similar to the wireless communication unit 125 in the first embodiment.

[0372] Figure 25 is a diagram showing the functional blocks of the communication terminal device 32 in the third embodiment, along with the data flow. The data acquisition unit 350, data output unit 351, history acquisition unit 152, intensity prediction unit 353, intensity correction unit 154, location identification unit 355, and likelihood function acquisition unit 356 shown in Figure 25 are functional blocks realized by the CPU 120 operating according to program 832.

[0373] The data acquisition unit 350, similar to the data acquisition unit 150 in the first embodiment, creates acquired information 181 based on information transmitted from the operation unit 122 and the wireless communication unit 125, and stores it in the storage device 121. However, the acquired information 181 in the third embodiment differs from the acquired information 181 in the first embodiment in that it may include a function database 370, operating condition information 371, initial distribution information 372, or likelihood function information 373.

[0374] Furthermore, the data acquisition unit 350 differs from the data acquisition unit 150 in the first embodiment in that it stores the second provisional position information 375 transmitted from the wireless communication unit 125 in the storage device 121.

[0375] The data output unit 351 differs from the data output unit 151 in the first embodiment in that it controls the wireless communication unit 125 to transmit the first provisional position information 374 to the communication terminal device 33.

[0376] Since the history acquisition unit 152 in the third embodiment is equivalent to the history acquisition unit 152 in the first embodiment, its description is omitted here.

[0377] In the third embodiment, the communication terminal device 33 is not necessarily able to observe the moving object (mobile communication terminal device 11) at the starting position. That is, when the first record of history information 175 is created in the communication terminal 33, the moving object may have already started moving. In that case, the communication terminal device 33 requests location information 380 from the communication terminal device 32 and obtains the current location information 380 of the moving object from the communication terminal device 32. The intensity correction unit 154 of the communication terminal device 33 creates corrected radio wave intensity information 179 using the location information 380 and stores it in the first record of history information 175.

[0378] The intensity prediction unit 353 has the function of obtaining predicted radio wave intensity information 178 by predicting the radio wave intensity to be acquired next based on the history information 175, and storing it in the history information 175. The method by which the intensity prediction unit 353 creates the predicted radio wave intensity information 178 will be described later.

[0379] Since the strength correction unit 154 in the third embodiment is equivalent to the strength correction unit 154 in the first embodiment, its description is omitted here.

[0380] The position identification unit 355 has the function of provisionally determining the position of the moving object using a particle filter while appropriately referring to the history information 175 and acquired information 181, and creating first provisional position information 374. The method by which the position identification unit 355 provisionally determines the position of the moving object and creates the first provisional position information 374 will be described later.

[0381] Furthermore, the location identification unit 355 has the function of identifying the location of the moving object by comparing the first provisional location information 374 and the second provisional location information 375, and storing it as location information 380 in the history information 175. The method by which the location identification unit 355 identifies the location of the moving object and creates the location information 380 will be described later.

[0382] The likelihood function acquisition unit 356, upon acquisition of operating condition information 371, searches the function database 370 using the operating condition information 371 as a search key and extracts likelihood function candidate information 377 associated with the operating condition information 371 from the function database 370. It then has the function of acquiring the extracted likelihood function candidate information 377 as likelihood function information 373. In other words, in the third embodiment, the likelihood function information 373 is not acquired directly by the data acquisition unit 350, but is acquired by the likelihood function acquisition unit 356 extracting it from the function database 370 acquired by the data acquisition unit 350.

[0383] The above describes the configuration and functions of the radio wave intensity correction system 30 in the third embodiment. Next, a method for correcting radio wave intensity using the radio wave intensity correction system 30 will be described.

[0384] Figure 26 is a flowchart showing the operation of the communication terminal devices 32 and 33 in the third embodiment. Figure 26 shows the operation of the communication terminal devices 32 and 33 until the radio wave intensity correction system 30 starts operation. In other words, Figure 26 is a flowchart showing the initial setup of the communication terminal devices 32 and 33.

[0385] When the process shown in Figure 26 is started, the communication terminal device 32 acquires the function database 370 (step S91). For example, the communication terminal device 32 acquires the function database 370 by installing it from a DVD-ROM. The data acquisition unit 350 stores the function database 370 in the storage device 121.

[0386] Next, the communication terminal device 32 acquires initial distribution information 372 (step S92). For example, in step S92, the operator of the communication terminal device 32 operates the operation unit 122 to input the initial distribution information 372. The operation unit 122 transmits the input initial distribution information 372 to the CPU 120 (data acquisition unit 350). The data acquisition unit 350 stores the initial distribution information 372 as acquired information 181 in the storage device 121.

[0387] Figure 27 illustrates the particle distribution in a typical initial state. Figure 28 illustrates the particle distribution in a third embodiment in its initial state.

[0388] In Figures 27 and 28, the rightmost point indicates the starting position, and the horizontal line indicates the path. The moving object moves from the starting position toward the left. The small circles on the horizontal line (path) represent particles. Communication terminal devices 32 and 33 are located on the path and are therefore not shown in the illustration, but they are located on the horizontal line. As previously explained, the placement positions of communication terminal devices 32 and 33 in the third embodiment are known.

[0389] In the initial state of the particle filter (at time 0), the distribution of particles is unknown. Therefore, as shown in Figure 27, it is common to distribute a predetermined number of particles uniformly throughout the path (the entire state space). Alternatively, although not shown here, particles can also be distributed randomly along the path.

[0390] However, in the third embodiment, before operation begins, the moving object is stationary at the starting point. That is, it can be predicted that even immediately after the start, the moving object is likely to be in the vicinity of the starting point.

[0391] Therefore, the radio wave intensity correction system 30 (position identification unit 355) in the third embodiment can generate particles such that the particle distribution in the initial state is, for example, as shown in Figure 28, by using initial distribution information 372 that biases particles toward the vicinity of the starting position of the moving object. In this way, calculations can be started from predicted samples corresponding to the initial state of the moving object, assuming the movement of the moving object, enabling efficient and highly accurate calculations.

[0392] Returning to Figure 26, once the initial distribution information 372 is acquired, the communication terminal device 32 acquires the operating condition information 371 (step S93). For example, in step S93, the operator of the communication terminal device 32 operates the operation unit 122 to input the operating condition information 371. The operator inputs the operating conditions for the current route as the operating condition information 371, while assuming the operating condition information 376 stored in the function database 370. The operation unit 122 transmits the operating condition information 371 input by the operator to the CPU 120 (data acquisition unit 350). The data acquisition unit 350 stores the operating condition information 371 as acquired information 181 in the storage device 121.

[0393] When the processing in step S93 is completed, the communication terminal device 32 acquires likelihood function information 373 (step S94). The likelihood function acquisition unit 356 searches the function database 370 according to the operating condition information 371 and determines the likelihood function information 373 from among the multiple likelihood function candidate information 377 stored in the function database 370.

[0394] For example, if the operating condition information 371 obtained in step S93 is "sunny" as a weather classification, searching the function database 370 using the operating condition information 371 as a search key will determine the likelihood function candidate information E (likelihood function candidate information 377), which stores "sunny" as the operating condition information 376, as the likelihood function information 373 and obtain it.

[0395] The likelihood function information 373 (likelihood function candidate information 377) is information that shows the likelihood function for calculating the weight of each particle when determining the position of a moving object using a particle filter. As will be described in detail later, in the third embodiment, the position determination unit 355 estimates the position of the moving object based on the likelihood function information 373 and obtains the first provisional position information 374.

[0396] In the first embodiment, the intensity prediction unit 153 was described as acquiring predicted radio wave intensity based on Equation 1. However, the real environment when a moving object is in motion may include factors that cannot be fully expressed by Equation 1. On the other hand, by using likelihood function information 373 that reflects the actual operating conditions, the radio wave intensity correction system 30 in the third embodiment can respond to more appropriate operating conditions and improve the estimation accuracy in the particle filter.

[0397] In particular, the radio wave intensity correction system 30 in the third embodiment acquires multiple likelihood function candidate information 377 and obtains more appropriate likelihood function information 373 based on the operating condition information 371. As a result, the accuracy of the corrected radio wave intensity is further improved by selecting the appropriate operating condition information 371. In addition, its versatility is improved as it can be adapted to various operating conditions.

[0398] When step S94 is executed, the communication terminal device 32 (radio wave intensity correction system 20) starts operation. Alternatively, after step S94 is completed, the system may be configured so that the operator can operate the control unit 122 to instruct the system to start operation.

[0399] Figure 29 is a flowchart showing the radio wave intensity correction method in the third embodiment.

[0400] The radio wave intensity correction system 30 (communication terminal device 32) constantly monitors whether it is the measurement timing (step S101) and whether history information 175 has been created (step S104) when it is in operation.

[0401] In the operation state of the radio wave intensity correction system 30, when time i has elapsed since the previous measurement and the measurement timing has arrived, the CPU 120 determines Yes in step S101.

[0402] If the result in step S101 is "Yes", the CPU 120 obtains the current time (time T in the measurement period) and the radio signal strength between the CPU and the mobile communication terminal device 11 (step S102). This process in step S102 corresponds to an observation performed with a period time i.

[0403] When step S102 is executed and time information 176 and radio wave strength information 177 are acquired, the history acquisition unit 152 creates a new record in the history information 175 (step S103) and stores the time information 176 and radio wave strength information 177 acquired in step S102 in that record.

[0404] Once the process in step S103 is completed, the radio wave intensity correction system 30 returns to its operational state. That is, it returns to a state where it monitors the measurement timing (step S101) and whether or not the history information 175 has been created (step S104).

[0405] In the operational state, when a new record of history information 175 is created, the radio wave strength correction system 30 determines Yes in step S104. The newly created record contains time information 176 and radio wave strength information 177, but does not contain predicted radio wave strength information 178, corrected radio wave strength information 179, location information 180, and location information 380. Therefore, the process in step S104 can be determined, for example, by whether or not there is a record in the history information 175 that does not contain predicted radio wave strength information 178.

[0406] In the following explanation of steps S105 to S107, the records of history information 175 that were determined to be newly created in step S104 may be referred to as "records to be processed."

[0407] Furthermore, after the record to be processed is created in step S103, it is, in principle, immediately identified in step S104, and the processing in steps S105 to S107 is then executed. Therefore, the time information 176 stored in the record to be processed can be considered as the current time (time T) in steps S105 to S107.

[0408] Furthermore, the process in step S103 is executed every time i, and a new record of history information 175 is created. In other words, the timing at which "Yes" is determined in step S104 also occurs every time i. Therefore, the processes in steps S105 through S107 can also be considered as processes that are executed periodically every time i.

[0409] If the result in step S104 is determined to be Yes, the intensity correction unit 154 performs radio wave intensity correction processing (step S105). Note that the radio wave intensity correction processing in the third embodiment (step S105) can be implemented in the same way as in step S5, so its explanation is omitted here.

[0410] Once the processing in step S105 is complete, the radio wave intensity correction system 30 (CPU 120) performs radio wave intensity prediction processing (step S106).

[0411] Figure 30 is a flowchart showing the radio wave intensity prediction process in the third embodiment. When the radio wave intensity prediction process is started, the intensity prediction unit 353 acquires the corrected radio wave intensity information 179 stored in the newly created record (processing target record) identified in step S104 (step S110).

[0412] In the radio wave intensity correction system 30 of the third embodiment, when the radio wave intensity prediction process (step S106) is executed, step S105 has already been executed. Therefore, the corrected radio wave intensity information 179 is already stored in the record to be processed. Consequently, when step S110 is executed, the intensity prediction unit 353 can acquire the corrected radio wave intensity information 179 stored in the record to be processed.

[0413] Next, the intensity prediction unit 353 determines whether the record to be processed is the first record (step S111). The process in step S111 can be performed, for example, in the same way as the process in step S12.

[0414] At the time the first record is created, the moving object has not yet started moving and is considered to be stationary at its starting position. Therefore, if the record to be processed is the first record (Yes in step S111), the position identification unit 355 acquires position information 180 with the position of the moving object set to "0" and stores the position information 180 in the record to be processed in the history information 175 (step S112).

[0415] Furthermore, in the third embodiment as well, since the moving object is considered to be stationary when the first record is created, the intensity of the radio waves from the stationary mobile communication terminal device 11 is expected not to change. Therefore, the intensity prediction unit 353 predicts that the corrected radio wave intensity of the record to be processed that is being acquired will be the radio wave intensity to be measured next. That is, the intensity prediction unit 353 acquires predicted radio wave intensity information 178 using the corrected radio wave intensity of the record to be processed as the predicted radio wave intensity (step S113).

[0416] When step S113 is executed and the predicted radio wave intensity information 178 is acquired, the intensity prediction unit 353 stores the acquired predicted radio wave intensity information 178 in the processing target record of the history information 175 (step S119).

[0417] Thus, in the first record, step S113, similar to the first embodiment, stores the same values ​​in the radio wave strength information 177, predicted radio wave strength information 178, and corrected radio wave strength information 179 in the first record of the history information 175.

[0418] When step S119 is executed, the radio wave intensity correction system 30 in the third embodiment terminates the radio wave intensity prediction process (step S106) and returns to the process shown in Figure 29.

[0419] On the other hand, if step S111 determines No (i.e., the record to be processed is not the first record), the intensity prediction unit 353 and the location identification unit 355 execute the processes in steps S114 to S119. Note that the processes in steps S114 to S119 can be executed in the same way as the processes in steps S24 to S29, so their explanation is omitted here.

[0420] As already explained, when step S119 is executed, the radio wave intensity correction system 30 in the third embodiment terminates the radio wave intensity prediction process (step S106) and returns to the process shown in Figure 29.

[0421] After completing step S106 and returning to Figure 29, the radio wave intensity correction system 30 performs particle filtering (step S107).

[0422] Figure 31 is a flowchart showing particle filtering in the third embodiment. Particle filtering is a process mainly performed by the position identification unit 355, which estimates the position of a moving object as first provisional position information 374 (second provisional position information 375 in other communication terminal devices 33).

[0423] When particle filtering is started, the positioning unit 355 determines whether the record to be processed is the first record (step S121). The process in step S121 can be performed, for example, in the same way as in step S12.

[0424] If the answer in step S121 is Yes, the positioning unit 355 uses the initial distribution information 372 to generate a predetermined number of particles within the path (state space) (step S122).

[0425] As already explained, the position identification unit 355 in the third embodiment uses initial distribution information 372 to distribute particles so that they are concentrated near the starting position. Therefore, the particle distribution immediately after the start will be, for example, as shown in Figure 28. When step S122 is completed, the radio wave intensity correction system 30 finishes the particle filtering process and returns to the process shown in Figure 29.

[0426] Note that when step S122 is executed, it means that preparations for particle filtering have been made, and the position of the moving object is not determined at this stage.

[0427] On the other hand, when No is determined in step S121 (when the record to be processed is not the first record), the position identification unit 355 determines the amount of change between the corrected radio wave intensity information 179 acquired at time T and the corrected radio wave intensity information 179 acquired at time (Ti) (step S123).

[0428] Then, the positioning unit 355 predicts the change in radio wave intensity between time T and time (T+i) based on the amount of change, and generates a predicted sample for time (T+i) (step S124).

[0429] As for methods of predicting the amount of change, for example, the velocity can be considered constant, and the amount of change can be assumed to be constant for each time interval i. Alternatively, the amount of change up to now can be determined from the historical information 175, and if the recent trend is increasing, it can be increased, and if the recent trend is decreasing, it can be decreased.

[0430] Figure 32 illustrates the distribution of predicted samples in the third embodiment. In the initial state, as shown in Figure 28, the particles were concentrated at the starting point, but as they move (or are predicted to move), the position where the particles are concentrated has shifted to the left.

[0431] Next, the positioning unit 355 acquires corrected radio wave intensity information 179 for time (T+i), and uses the corrected radio wave intensity information 179 and the predicted samples generated in step S124 to calculate a weight for each particle using a likelihood function (step S125).

[0432] Note that the actual processing using particle filters is divided into pre-observation processing and post-observation processing at time (T+i), and since the explanation (flowchart) becomes complicated when paralleled with the radio wave intensity correction processing, only a conceptual explanation will be given here. The specific algorithm for particle filters can be realized by appropriately applying conventional technologies. For example, technologies described in Japanese Patent Publication No. 2010-239331 (Patent No. 5240691) and Japanese Patent Publication No. 2018-169310 (Patent No. 6730953) can be applied.

[0433] In this case, the position identification unit 355 in the third embodiment determines the weight of each particle using the likelihood function information 373 selected by the operating condition information 371. Therefore, since the calculation can be performed using a likelihood function corresponding to the conditions when the moving object is operating, the accuracy is improved.

[0434] Figure 33 shows the size of each particle shown in Figure 32, with the weight values ​​reflected in the result. In Figure 33, the position of each particle in the prediction sample generated in step S124 is not moved, but only the size is changed according to the weight, and the weights are visualized.

[0435] When step S125 is executed, the positioning unit 355 estimates the position of the particle with the maximum weight as the provisional position of the moving object (step S126).

[0436] The position identification unit 355 acquires the provisional position determined in step S126 as first provisional position information 374 and stores it in the storage device 121.

[0437] As a result, the data output unit 351 transmits the first provisional location information 374 acquired in step S126 to another communication terminal device 33. The location identification unit 355 then acquires the location of the moving object based on the created first provisional location information 374 and second provisional location information 375 (step S127) and stores it in the history information 175 as non-provisional location information 380.

[0438] In the third embodiment, the position identification unit 355 identifies the position information 380 by assuming that the moving object is located at an intermediate point between the first provisional position information 374 and the second provisional position information 375 (that position is the position of the moving object). However, the method of identifying the position information 380 using the first provisional position information 374 and the second provisional position information 375 is not limited to this.

[0439] Thus, in the third embodiment, the positioning unit 355 uses a particle filter to determine the position of the moving object, thereby improving accuracy compared to determining the position solely from radio wave intensity.

[0440] Once the position of the moving object is determined, the positioning unit 355 resamples the particles according to the determined weights (step S128). Specifically, it increases the number of particles around the weighted particles and decreases the number of particles far from the weighted particles. At this time, the positioning unit 355 moves particles that are located behind the previous position of the moving object up to time T. This is because if the moving object were to move to a position behind the previous position of the moving object (towards the starting point), it would mean that it traveled in reverse along its path, which does not meet the preconditions, and such particles are considered unreliable.

[0441] Figure 34 shows an example of particle resampling shown in Figure 33. As shown in Figure 34, no particles are placed behind the position of the moving object at time T (around the position indicated by the arrow) (they are deleted). Note that in a particle filter, the number of particles must be kept constant, so if particles are deleted, the same number of particles must be repositioned at other locations. In other words, the process is equivalent to moving the particles. Specifically, in the third embodiment, after resampling, particles remaining behind the position at time T are moved to the position at time T. Note that the weight of the particles after resampling is constant and is performed after the position of the moving object has been determined, so it is not considered to affect the position determination. Furthermore, due to the characteristic that particles at distant positions are deleted each time the moving object moves, particles do not accumulate at the position at time T.

[0442] Once resampling is complete, the radio wave intensity correction system 30 terminates the particle filtering process and returns to the process shown in Figure 29.

[0443] When step S128 is completed and the process returns to Figure 29, the radio wave intensity correction system 30 returns to the operational state and enters a waiting state until time i has elapsed.

[0444] As described above, the radio wave intensity correction system 30 in the third embodiment also achieves the same effects as the radio wave intensity correction systems 10 and 20 in the other embodiments.

[0445] Furthermore, the positioning unit 355 improves accuracy compared to correcting solely by radio wave intensity by using a particle filter to determine the position.

[0446] Furthermore, the position identification unit 355 can perform calculations by excluding particles that are distributed behind the predicted position of the moving object prior to time (T+1) from the samples predicted at time (T+1), thereby excluding obviously inappropriate samples and improving accuracy.

[0447] Furthermore, the system includes a storage device 121 that stores multiple likelihood function candidate information 377, each associated with operating condition information 371, and a data acquisition unit 350 (operating condition acquisition unit) that acquires the operating condition information 371. The position identification unit 355 identifies one likelihood function candidate information 377 from among the multiple likelihood function candidate information 377 according to the operating condition information 371 acquired by the data acquisition unit 350, and calculates the weight of each particle using the identified likelihood function candidate information 377 as likelihood function information 373. This allows the system to select and calculate the optimal likelihood function information 373 from among the multiple likelihood function candidate information 377 according to the operating conditions. Therefore, the calculation accuracy is improved.

[0448] Furthermore, the operating conditions information 371 includes at least one of the following: day of the week, time, weather, region, season, indoor / outdoor distinction, type of moving object, surrounding environment of the moving object, and route distinction. This allows the calculation to be performed using likelihood function information 373 that is appropriate for these operating conditions, thus improving accuracy.

[0449] Furthermore, the positioning unit 355 uses initial distribution information in which particles are biased towards the vicinity of the starting position of the moving object. This improves accuracy by starting calculations from predicted samples corresponding to the initial state of the moving object.

[0450] Furthermore, by providing multiple communication terminal devices 32, 33, and determining location information 380 based on first provisional location information 374 determined by the location identification unit 355 of one communication terminal device 32 and second provisional location information 375 determined by the location identification unit 355 of the other communication terminal devices 33, the influence of irregular information is suppressed, thereby improving accuracy.

[0451] Furthermore, in the third embodiment, the communication terminal device 32 is described as transmitting and receiving first provisional location information 374 and second provisional location information 375 via wireless communication with the communication terminal device 33. However, the transmission and reception of the first provisional location information 374 and second provisional location information 375 may be performed via a server device.

[0452] Furthermore, since the calculation to determine the position of a moving object using a particle filter is a relatively computationally intensive process, a server device configured as a high-performance device may be provided, as in the second embodiment.

[0453] <4. Fourth Embodiment> Figure 35 is a diagram showing the configuration of the arrival time notification system 40 in the fourth embodiment. The arrival time notification system 40 comprises a wireless on-board device 41 mounted on the bus 9 as a mobile vehicle, a notification device 42 installed at the bus stop which is the destination of the bus 9, an observation device 43 installed on a building such as a utility pole, and a server device 44 installed at the office or management center of the bus company operating the bus 9.

[0454] As will be explained in more detail later, the arrival time notification system 40 is configured as a system that notifies the predicted arrival time, which indicates the time when a moving object traveling along a travel route is expected to arrive at its destination.

[0455] Furthermore, the notification device 42 and the observation device 43 communicate wirelessly with the wireless vehicle-mounted device 41. In addition, the notification device 42 and the observation device 43 communicate data with the server device 44 via the network 94. Moreover, the wireless communication between the wireless vehicle-mounted device 41 and the notification device 42 and the observation device 43 is low-power long-distance wireless communication, and in the fourth embodiment, it is Wi-Fi HaLow.

[0456] Network 94 is assumed to be a wired communication network. However, network 94 may also be a wireless communication network. Furthermore, the server device 44 may have the function of communicating wirelessly with the wireless vehicle-mounted device 41. Although only one notification device 42 and one observation device 43 are shown in Figure 35, the number of notification devices 42 and observation devices 43 in the arrival time notification system 40 is not limited to one each. Typically, the arrival time notification system 40 is equipped with multiple notification devices 42 and multiple observation devices 43.

[0457] Figure 36 is a block diagram showing the wireless in-vehicle device 41 in the fourth embodiment. As already explained, the wireless in-vehicle device 41 is mounted on a mobile bus 9 and its position changes as the bus 9 moves. In other words, the wireless in-vehicle device 41 corresponds to a mobile communication terminal device.

[0458] The wireless in-vehicle device 41 includes a CPU 410, a storage device 411, an operation unit 412, a display unit 413, and a wireless communication unit 415.

[0459] The acquired information 470 is a general term for the information acquired by the wireless in-vehicle device 41. The acquired information 470 includes information obtained from external devices via the wireless communication unit 415 and information input by operating the operation unit 412. The acquired information 470 may also include pre-stored information, such as setting information.

[0460] Furthermore, output information 471 is a general term for information transmitted to external devices via the wireless communication unit 415 and information output by being displayed on the display unit 413. If the wireless in-vehicle device 41 is equipped with a speaker, output information 471 may also be related to voice information.

[0461] The CPU 410 reads and executes the program 841 stored in the memory device 411, performing calculations on various data and generating control signals. Thus, the CPU 410 controls the various components of the wireless in-vehicle device 41 and has the function of calculating and creating various data. In other words, the wireless in-vehicle device 41 is configured as a general-purpose computer.

[0462] The storage device 411 provides a function for storing various types of data in the wireless in-vehicle device 41. In other words, the storage device 411 stores electronically fixed information in the wireless in-vehicle device 41.

[0463] The storage device 411 can include RAM or buffers used as a temporary working area for the CPU 410, read-only ROM, non-volatile memory (such as NAND memory), hard disks for storing relatively large amounts of data, and portable storage media mounted on dedicated reading devices (such as CD-ROMs, DVD-ROMs, PC cards, SD cards, and USB memory). In Figure 36, the storage device 411 is illustrated as if it were a single structure. However, typically, the storage device 411 consists of multiple types of devices (or media) as exemplified above, selected as needed. In other words, the storage device 411 is a general term for a group of devices that have the function of storing data.

[0464] Furthermore, the actual CPU 410 is an electronic circuit that has high-speed accessible RAM built into it. However, for the sake of explanation, the memory device of such a CPU 410 will also be included in the description of the memory device 411. In other words, data that the CPU 410 itself temporarily stores will also be described as being stored by the memory device 411. As shown in Figure 36, the memory device 411 is used to store the program 841, acquired information 470, output information 471, and so on.

[0465] The operation unit 412 is hardware that an operator or other person operates to input instructions to the wireless in-vehicle device 41. The information input in this way is stored in the storage device 411 as acquired information 470. Examples of the operation unit 412 include various keys and buttons, switches, touch panels, pointing devices, or jog dials.

[0466] The display unit 413 is hardware that has the function of outputting various data (for example, output information 471) to operators, etc. Examples of the display unit 413 include lamps, LEDs, CRTs, liquid crystal displays, and liquid crystal panels.

[0467] The wireless communication unit 415 provides the function for the wireless vehicle-mounted device 41 to communicate wirelessly with external devices (notification device 42 and observation device 43). As a result, in the fourth embodiment, the wireless vehicle-mounted device 41 performs wireless communication with the notification device 42 and observation device 43 in accordance with the Wi-Fi HaLow standard.

[0468] Information received by the wireless communication unit 415 is transmitted to the CPU 410 and stored in the storage device 411 as acquired information 470. Information to be transmitted by the wireless communication unit 415 (for example, output information 471) is transmitted from the CPU 410.

[0469] The configuration of the wireless in-vehicle device 41 is not limited to the configuration shown in Figure 36. For example, the wireless in-vehicle device 41 may include a sensor that takes observed information as acquired information 470, a timer for measuring time, a speaker that outputs information related to voice, and so on.

[0470] Figure 37 is a block diagram showing the notification device 42 in the fourth embodiment. The notification device 42 comprises a CPU 420, a storage device 421, an operation unit 422, a display unit 423, a communication unit 424, and a wireless communication unit 425. The notification device 42 is installed near the destination of the bus 9 and communicates wirelessly with the wireless onboard device 41.

[0471] As shown in Figure 37, the acquired information 472 is a general term for the information acquired by the notification device 42. The acquired information 472 includes information obtained from external devices via the communication unit 424 or the wireless communication unit 425, and information input by operating the operation unit 422. The acquired information 472 may include predicted arrival time information 473, but details will be described later. In addition, the acquired information 472 may include pre-stored information such as setting information.

[0472] Furthermore, output information 474 is a general term for information transmitted to external devices via the communication unit 424 or the wireless communication unit 425, and information output by being displayed on the display unit 423.

[0473] Furthermore, measurement information 475, time information 176, and radio wave intensity information 177 will be described later.

[0474] The CPU 420 reads and executes the program 842 stored in the memory device 421, performing calculations on various data and generating control signals. Thus, the CPU 420 controls each component of the notification device 42 and has the function of calculating and creating various data. In other words, the notification device 42 is configured as a general-purpose computer.

[0475] The storage device 421 provides the function of storing various data in the notification device 42. In other words, the storage device 421 stores electronically fixed information in the notification device 42. As shown in Figure 37, the storage device 421 is used to store the program 842, acquired information 472, output information 474, and measurement information 475, etc. Note that the storage device 421 can be configured as a device equivalent to the storage device 411, except that it is accessed by the CPU 420, so a detailed explanation is omitted here.

[0476] The operation unit 422 is hardware that an operator or other person operates to input instructions to the notification device 42. The information input in this way is transmitted to the CPU 420 and stored in the storage device 421 as acquired information 472. Examples of the operation unit 422 include various keys and buttons, switches, touch panels, pointing devices, or jog dials.

[0477] The display unit 423 is hardware that has the function of outputting various data (for example, output information 474) to operators, etc. Examples of the display unit 423 include lamps, LEDs, CRTs, liquid crystal displays, and liquid crystal panels.

[0478] As already explained, the notification device 42 is intended to be installed at a bus stop. Therefore, the display unit 423 of the notification device 42 constitutes a device that outputs information to passengers waiting for the bus 9. The arrival time notification system 40 displays the predicted arrival time information 473 on the display unit 423. In this way, the display unit 423 is a device that notifies passengers by outputting the predicted arrival time information 473.

[0479] The communication unit 424 provides the notification device 42 with the function of performing data communication with external devices (observation device 43 and server device 44). As a result, in the fourth embodiment, the notification device 42 performs data communication with the observation device 43 and the server device 44 via the network 94.

[0480] Information received by the communication unit 424 is transmitted to the CPU 420 and stored in the storage device 421 as acquired information 472. Information to be transmitted by the communication unit 424 is transmitted from the CPU 420.

[0481] The wireless communication unit 425 provides the notification device 42 with the function of wirelessly communicating with an external device (wireless in-vehicle device 41). As a result, in the fourth embodiment, the notification device 42 performs wireless communication with the wireless in-vehicle device 41 in accordance with the Wi-Fi HaLow standard.

[0482] Therefore, the notification device 42 corresponds to a communication terminal device.

[0483] The data received by the wireless communication unit 425 from the wireless in-vehicle device 41 is transmitted to the CPU 420. The information acquired in this way is stored in the storage device 421 as acquired information 472.

[0484] Furthermore, the wireless communication unit 425 also has the function of measuring the strength of radio waves transmitted from the wireless vehicle-mounted device 41 and transmitting this information to the CPU 420. In other words, the wireless communication unit 425 constitutes a strength acquisition unit that acquires the strength of the radio waves between the wireless vehicle-mounted device 41 and the notification device 42. To put it another way, the notification device 42 is configured by the wireless communication unit 425 as a device that observes the strength of the radio waves between it and the wireless vehicle-mounted device 41. The wireless communication unit 425 is configured to measure the strength of the radio waves at predetermined time intervals i and transmit the results to the CPU 420.

[0485] Figure 38 is a diagram showing the functional blocks of the notification device 42 in the fourth embodiment, along with the data flow. The data acquisition unit 450 and the data output unit 451 shown in Figure 38 are functional blocks realized by the CPU 420 operating according to the program 842.

[0486] The data acquisition unit 450 has the function of creating acquired information 472 based on information transmitted from the operation unit 422, the communication unit 424, and the wireless communication unit 425. The acquired information 472 created by the data acquisition unit 450 is stored in the storage device 421.

[0487] In particular, the data acquisition unit 450 acquires the predicted arrival time information 473 received by the communication unit 424 from the communication unit 424 and creates acquired information 472. As will be described in detail later, the predicted arrival time information 473 included in the acquired information 472 is information transmitted from the server device 44. Note that acquired information 472 does not necessarily include the predicted arrival time information 473, and there are naturally acquired information 472 that do not include these.

[0488] On the other hand, the data acquisition unit 450 has the function of creating measurement information 475 by associating the radio wave strength information 177, which is measured and acquired by the wireless communication unit 425 at time intervals i, with time information 176 indicating the time of acquisition, and storing it in the storage device 421. Unlike the acquired information 472, the created measurement information 475 always includes the time information 176 and radio wave strength information 177 that are associated with each other.

[0489] The data output unit 451 has the function of selecting and transmitting the output information 474 to one of the display unit 423, communication unit 424, and wireless communication unit 425, depending on the output information 474. For example, for output information 474 that should be output (displayed) to the display unit 423, the display unit 423 is selected as the output destination, and the display unit 423 is controlled to display the output information 474.

[0490] Furthermore, in the fourth embodiment, the data output unit 451 also has a function to retrieve the predicted arrival time information 473 from the acquired information 472 and include it in the output information 474 once the acquired information 472 containing the predicted arrival time information 473 is stored. As a result, the predicted arrival time information 473 is transmitted to the display unit 423 and displayed.

[0491] Furthermore, the data output unit 451 selects the communication unit 424 as the output destination for output information 474 to be output (transmitted) to the server device 44 (or observation device 43), and controls the communication unit 424 to transmit said output information 474 to the server device 44 (or observation device 43). For example, output information 474 that should be transmitted to the server device 44 (or observation device 43) may include measurement information 475.

[0492] Furthermore, in the fourth embodiment, the data output unit 451 also has the function of acquiring measurement information 475 when it is created and including it in the output information 474. As a result, the measurement information 475 is transmitted to the server device 44 via the communication unit 424.

[0493] Furthermore, the data output unit 451 selects the wireless communication unit 425 as the output destination for output information 474 to be output (transmitted) to the wireless in-vehicle device 41, and controls the wireless communication unit 425 to transmit the output information 474 to the wireless in-vehicle device 41.

[0494] As will be described in more detail later, with this configuration, the notification device 42 acquires measurement information 475 at every time i and transmits it to the server device 44. When it receives predicted arrival time information 473 from the server device 44, it outputs the predicted arrival time information 473 to the display unit 423 to provide notification.

[0495] Figure 39 is a block diagram showing the observation device 43 in the fourth embodiment. The observation device 43 comprises a CPU 430, a storage device 431, an operation unit 432, a display unit 433, a communication unit 434, and a wireless communication unit 435. As already described, the observation device 43 is a device that is mounted on a utility pole.

[0496] As shown in Figure 39, the acquired information 476 is a general term for the information acquired by the observation device 43.

[0497] The CPU 430 reads and executes the program 843 stored in the memory device 431, performing calculations on various data and generating control signals. Thus, the CPU 430 controls each component of the observation device 43 and has the function of calculating and creating various data. In other words, the observation device 43 is configured as a general-purpose computer.

[0498] The memory device 431 provides the function of storing various data in the observation device 43. In other words, the memory device 431 stores electronically fixed information in the observation device 43. As shown in Figure 39, the memory device 431 is used to store the program 843, measurement information 475, acquisition information 476, and output information 477, etc. Note that the memory device 431 can be configured as a device equivalent to the memory device 421, except that it is accessed by the CPU 430, so a detailed explanation is omitted here.

[0499] The control unit 432 is hardware that an operator or other person uses to input instructions to the observation device 43. The information input in this way is transmitted to the CPU 430 and stored in the storage device 431 as acquired information 476. Examples of the control unit 432 include various keys and buttons, switches, touch panels, pointing devices, or jog dials.

[0500] The display unit 433 is hardware that has the function of outputting various data (for example, output information 477) to operators, etc. Examples of the display unit 433 include lamps, LEDs, CRTs, liquid crystal displays, and liquid crystal panels.

[0501] As already explained, in the arrival time notification system 40, the observation device 43 is envisioned as a device installed on a utility pole laid along the route of the bus 9. Therefore, unlike the display device 423 of the notification device 42, the display unit 433 of the observation device 43 is not normally a device that outputs information to passengers.

[0502] The communication unit 434 provides the function for the observation device 43 to communicate data with external devices (notification device 42 and server device 44). As a result, in the fourth embodiment, the observation device 43 communicates data with the notification device 42 and the server device 44 via the network 94.

[0503] Information received by the communication unit 434 is transmitted to the CPU 430 and stored in the storage device 431 as acquired information 476. Information to be transmitted by the communication unit 434 is transmitted from the CPU 430.

[0504] The wireless communication unit 435 provides the observation device 43 with the function to communicate wirelessly with an external device (wireless vehicle-mounted device 41). As a result, in the fourth embodiment, the observation device 43 communicates wirelessly with the wireless vehicle-mounted device 41 in accordance with the Wi-Fi HaLow standard. Therefore, the observation device 43 corresponds to a communication terminal device.

[0505] Furthermore, data received by the wireless communication unit 435 from the wireless in-vehicle device 41 is transmitted to the CPU 430. The information acquired in this manner is stored in the storage device 431 as acquired information 476.

[0506] Furthermore, the wireless communication unit 435 also has the function of measuring the strength of radio waves transmitted from the wireless vehicle-mounted device 41 and transmitting it to the CPU 430. In other words, the wireless communication unit 435 constitutes a strength acquisition unit that acquires the radio wave strength between the wireless vehicle-mounted device 41 and the observation device 43. To put it another way, the observation device 43 is configured as a device that observes the radio wave strength between the wireless vehicle-mounted device 41 and the wireless communication unit 425. The wireless communication unit 435, like the wireless communication unit 425, measures the radio wave strength at predetermined time intervals i and transmits it to the CPU 430.

[0507] Figure 40 is a diagram showing the functional blocks of the observation device 43 in the fourth embodiment, along with the data flow. The data acquisition unit 452 and the data output unit 453 shown in Figure 40 are functional blocks realized by the CPU 430 operating according to the program 843.

[0508] The data acquisition unit 452 has the function of creating acquired information 476 based on information transmitted from the operation unit 432, the communication unit 434, and the wireless communication unit 435. The acquired information 476 created by the data acquisition unit 452 is stored in the storage device 431.

[0509] On the other hand, the data acquisition unit 452 has the function of creating measurement information 475 by associating the radio wave strength information 177, which is measured and acquired by the wireless communication unit 435 at time intervals i, with time information 176 indicating the time of acquisition, and storing it in the storage device 431. Unlike the acquired information 476, the created measurement information 475 always includes the time information 176 and radio wave strength information 177 that are associated with each other.

[0510] The data output unit 453 has the function of selecting and transmitting the output information 477 from among the display unit 433, communication unit 434, and wireless communication unit 435, according to the output information 477.

[0511] Furthermore, the data output unit 453 selects the communication unit 434 as the output destination for output information 477 to be output (transmitted) to the server device 44 (or notification device 42), and controls the communication unit 434 to transmit said output information 477 to the server device 44 (or notification device 42). For example, output information 477 that includes measurement information 475 may be included as output information 477 to be transmitted to the server device 44 (or notification device 42).

[0512] Furthermore, in the fourth embodiment, the data output unit 453 also has the function of acquiring measurement information 475 when it is created and including it in the output information 477. As a result, the measurement information 475 is transmitted to the server device 44 via the communication unit 434.

[0513] Furthermore, the data output unit 453 selects the wireless communication unit 435 as the output destination for output information 477 to be output (transmitted) to the wireless in-vehicle device 41, and controls the wireless communication unit 435 to transmit the output information 477 to the wireless in-vehicle device 41.

[0514] As will be explained in more detail later, with this configuration, the observation device 43 is configured to acquire measurement information 475 at time intervals i and transmit it to the server device 44. On the other hand, unlike the notification device 42, the observation device 43 does not receive predicted arrival time information 473 from the server device 44, nor does it output the predicted arrival time information 473 to the display unit 433.

[0515] Figure 41 is a block diagram showing the server device 44 in the fourth embodiment. As already described, the server device 44 is a device mainly installed in a business office (indoors).

[0516] The server device 44 includes a CPU 440, a storage device 441, an operation unit 442, a display unit 443, and a communication unit 444.

[0517] The history information 175 is a table-structured information in which time information 176, radio wave strength information 177, predicted radio wave strength information 178, corrected radio wave strength information 179, and location information 180 are stored in a single record.

[0518] The predicted arrival time information 473 shown in Figure 41 will be discussed later.

[0519] Furthermore, acquired information 478 is a general term for the information acquired by the server device 44. Acquired information 478 includes information obtained from external devices via the communication unit 444 and information input by operating the operation unit 442.

[0520] Furthermore, the output information 479 is a general term for information transmitted to an external device via the communication unit 444 and information output by being displayed on the display unit 443. For example, in the fourth embodiment, the server device 44 includes the predicted arrival time information 473 in the output information 479 and transmits it to the notification device 42. If the server device 44 is equipped with a speaker, the output information 479 may be related to voice information.

[0521] Furthermore, configuration information 480 is a general term for information that is stored in the server device 44 in advance before operation begins.

[0522] Figure 42 is a diagram illustrating the information included in the setting information 480 in the fourth embodiment. However, Figure 42 does not illustrate all the information included in the setting information 480.

[0523] The configuration information 480 contains route information 481, terminal location information 482, initial distribution information 483, model database 484, and function database 485.

[0524] Route information 481 is information indicating the route of the bus 9 (mobile entity). In the fourth embodiment, route information 481 is information indicating the location of each bus stop that is the destination of the bus 9 (including the location of the starting stop and the location of the ending stop).

[0525] However, the route information 481 is not limited to this type of information. Furthermore, a database may be configured to store multiple route information entries 481, each with a different route, and allow for selection.

[0526] The terminal location information 482 is information that stores the location of each notification device 42 and each observation device 43. In the fourth embodiment, the location of each notification device 42 corresponds to the location of each stop included in the route information 481.

[0527] The initial distribution information 483 indicates how each particle should be distributed in advance (in its initial state) across the state space when determining the position of the moving object using the particle filter described later. In the fourth embodiment, the initial distribution information 483 is set to a distribution in which particles are biased towards the vicinity of the starting position of the moving object. As a result, the arrival time notification system 40 can start calculations from predicted samples corresponding to the initial state of the moving object, thus improving accuracy compared to using a general uniform distribution.

[0528] Model Database 484 is a database with a table structure that associates environmental condition information and model candidate information into a single record. Model Database 484 can retrieve corresponding model candidate information using environmental condition information 287 (see Figure 43) as the search key. The model candidate information extracted through such a search becomes model information 288 (see Figure 43). However, environmental condition information 287 and model information 288 will be described later.

[0529] The function database 485 is a database with a table structure that associates operating condition information and likelihood function candidate information into a single record. The function database 485 can retrieve the corresponding likelihood function candidate information using the operating condition information 371 (see Figure 43) as the search key. The likelihood function information extracted by such a search becomes the likelihood function information 373 (see Figure 43). However, the operating condition information 371 and likelihood function information 373 will be described later.

[0530] Returning to Figure 41, the CPU 440 reads and executes the program 844 stored in the memory device 441, performing calculations on various data and generating control signals. Thus, the CPU 440 controls the various components of the server device 44 and has the function of calculating and creating various data. In other words, the server device 44 is configured as a general-purpose computer.

[0531] The storage device 441 provides the function of storing various data in the server device 44. In other words, the storage device 441 stores electronically fixed information in the server device 44. As shown in Figure 41, the storage device 441 is used to store programs 844, history information 175, predicted arrival time information 473, acquired information 478, output information 479, and setting information 480, etc. Note that the storage device 441 can be configured as a device equivalent to storage devices 421 and 431, except that it is accessed by the CPU 440, so a detailed explanation is omitted here.

[0532] The operation unit 442 is hardware that an operator or other person uses to input instructions to the server device 44. The information input in this way is stored in the storage device 441 as acquired information 478. Examples of the operation unit 442 include various keys and buttons, switches, touch panels, pointing devices, or jog dials.

[0533] The display unit 443 is hardware that has the function of outputting various data (for example, output information 479) to operators, etc. Examples of the display unit 443 include lamps, LEDs, CRTs, liquid crystal displays, and liquid crystal panels.

[0534] The communication unit 444 provides the server device 44 with the function to perform data communication with external devices (notification device 42 and observation device 43). As a result, the server device 44 in the fourth embodiment can perform data communication with the notification device 42 and observation device 43 via the network 94.

[0535] The information received by the communication unit 444 is transmitted to the CPU 440 and stored in the storage device 441 as acquired information 478. However, as will be described in detail later, among the information received by the communication unit 444, the information related to the measurement information 475 is stored in the storage device 441 as information that constitutes history information 175, rather than as acquired information 478.

[0536] Furthermore, information transmitted by the communication unit 444 (for example, output information 479) is received from the CPU 440.

[0537] Although not shown in Figure 41, the server device 44 is equipped with a timer for measuring time. Furthermore, the configuration of the server device 44 is not limited to that shown in Figure 41. For example, the server device 44 may be equipped with a sensor that takes observed information as acquired information 478, a speaker that outputs information related to sound, and so on.

[0538] Figure 43 is a diagram showing the functional blocks of the server device 44 in the fourth embodiment, along with the data flow. The data acquisition unit 454, data output unit 455, history acquisition unit 456, device identification unit 457, intensity prediction unit 458, intensity correction unit 459, location identification unit 460, and time prediction unit 461 shown in Figure 43 are functional blocks realized by the CPU 440 operating according to program 844.

[0539] The data acquisition unit 454 has the function of creating acquired information 478 based on the information transmitted from the operation unit 442 and the communication unit 444. The acquired information 478 created by the data acquisition unit 454 is stored in the storage device 441.

[0540] Furthermore, the data acquisition unit 454 has the function of searching the model database 484 and the function database 485 to obtain the necessary information.

[0541] For example, when environmental condition information 287 is acquired, the data acquisition unit 454 searches the model database 484 using the environmental condition information 287 as a search key, extracts model candidate information associated with the environmental condition information 287, and converts it into model information 288. The model information 288 thus acquired is stored in the storage device 441. In other words, Figure 43 shows the state after the data acquisition unit 454 has finished searching the model database 484 and storing the model information 288.

[0542] The environmental condition information 287 is information indicating the environmental conditions when the arrival time notification system 40 is in operation. In the fourth embodiment, the environmental condition information 287 includes at least one of the following: day of the week, time, weather, region, season, distinction between indoors and outdoors, type of moving object, surrounding environment of the moving object, and distinction between route.

[0543] Furthermore, the model information 288 is information that shows the relationship between the distance between the notification device 42 and the wireless in-vehicle device 41 (terminal distance CD) and the radio wave intensity. By acquiring such model information 288, the data acquisition unit 454 in the fourth embodiment also functions as a model acquisition unit.

[0544] Furthermore, once the operating condition information 371 is acquired, the data acquisition unit 454 uses the operating condition information 371 as a search key to search the function database 485 and extracts the likelihood function candidate information associated with the operating condition information 371, which is then converted into likelihood function information 373. The likelihood function information 373 thus acquired is stored in the storage device 441. In other words, Figure 43 shows the state after the data acquisition unit 454 has finished searching the function database 485 and storing the likelihood function information 373.

[0545] The likelihood function information 373 is information that shows the likelihood function used to calculate the weight of each particle when determining the position of a moving object using the particle filter described later. By acquiring such likelihood function information 373, the data acquisition unit 454 in the fourth embodiment also functions as a likelihood function acquisition unit.

[0546] The operating conditions information 371 is information indicating the operating conditions when the arrival time notification system 40 is in operation. In the fourth embodiment, the operating conditions information 371 includes at least one of the following: day of the week, time, weather, region, season, distinction between indoor and outdoor, type of mobile object, surrounding environment of mobile object, and distinction between route.

[0547] Figure 43 shows that the acquired information 478 includes operating condition information 371, likelihood function information 373, environmental condition information 287, and model information 288. However, this information is not related to each other in the acquired information 478, and unless otherwise specified, it generally exists as separate pieces of information.

[0548] The data output unit 455 has the function of selecting and transmitting the output destination of the output information 479 from among the display unit 443 and the communication unit 444, according to the output information 479. For example, for output information 479 that should be output (displayed) toward the display unit 443, the display unit 443 is selected as the output destination, and the display unit 443 is controlled to display the output information 479. Also, for output information 479 that should be output (transmitted) toward the notification device 42 or the observation device 43, the communication unit 444 is selected as the output destination, and the communication unit 444 is controlled to transmit the output information 479 toward the notification device 42 or the observation device 43.

[0549] Furthermore, the data output unit 455 also has the function of editing the output information 479 by referring to the history information 175 as needed. For example, when displaying location information 180 included in the history information 175 on the display unit 443, the location information 180 is obtained from the history information 175 and used as output information 479. Although not shown in the figures, the data output unit 455 may also have the function of editing the output information 479 according to the acquired information 478.

[0550] The history acquisition unit 456 creates a new record of history information 175 corresponding to the transmission destination each time the communication unit 444 receives measurement information 475 from the notification device 42 or observation device 43. The unit then stores the time information 176 and radio wave intensity information 177 contained in the measurement information 475 in the newly created record.

[0551] Thus, the history acquisition unit 456 has the function of acquiring history information 175 by creating history information 175. In the fourth embodiment, measurement information 475 is transmitted from all notification devices 42 and all observation devices 43. Therefore, as shown in Figure 43, the server device 44 creates history information 175 for each source. Although not shown in the figure, each history information 175 is associated with identification information (terminal identifier) ​​indicating the source (observation source) by the history acquisition unit 456.

[0552] The device identification unit 457 has the function of identifying a target communication terminal device from among multiple communication terminal devices (notification device 42 and observation device 43) by comparing the radio wave strength between the multiple communication terminal devices and the wireless vehicle-mounted device 41. The target communication terminal device is the device that provides the information (time information 176 and radio wave strength information 177) that forms the basis for creating the history information 175. In other words, the information acquired at the target communication terminal device is used as the information for creating the history information 175.

[0553] In the fourth embodiment, the device identification unit 457 will be described using an example where it identifies one target communication terminal device from among multiple communication terminal devices, for the sake of simplicity. However, for example, several communication terminal devices may be identified as target communication terminal devices from among a large number of communication terminal devices. In that case, the provisional position of the bus 9 will be determined by the measurement information 475 measured by the multiple target communication terminal devices. Then, as shown in the third embodiment, the position can be determined by performing a statistical or averaging process on the multiple provisional positions. The method by which the device identification unit 457 identifies the target device will be described later.

[0554] The intensity prediction unit 458 has the function of acquiring predicted radio wave intensity information 178 by predicting the next radio wave intensity to be acquired (radio wave intensity information 177) based on the history information 175, and storing it in the history information 175. The method by which the intensity prediction unit 458 creates the predicted radio wave intensity information 178 will be described later.

[0555] The intensity correction unit 459 has the function of obtaining corrected radio wave strength by correcting the radio wave strength (radio wave strength information 177) included in the history information 175 according to the predicted radio wave strength information 178, and storing it in the history information 175 as corrected radio wave strength information 179. The method by which the intensity correction unit 459 creates the predicted radio wave strength information 178 will be described later.

[0556] The positioning unit 460 has the function of determining the position of a moving object and creating position information 180 based on the corrected radio wave intensity information 179 included in the history information 175 and the model information 288. The positioning unit 460 determines the position of the bus 9 using a particle filter, but the details will be described later.

[0557] The time prediction unit 461 obtains predicted arrival times for the bus 9 to arrive at each bus stop (the location of each notification device 42) by predicting the predicted arrival time based on the location of the moving object (location information 180) identified by the location identification unit 460, the route information 481 (travel route information), and the terminal location information 482, and creates predicted arrival time information 473.

[0558] There is no need to announce the estimated arrival time at bus stops where bus 9 has already arrived. Similarly, there is no need to announce the estimated arrival time at the observation device 43. Therefore, the time prediction unit 461 creates predicted arrival time information 473 only for bus stops where bus 9 has not yet arrived, and transmits it only to the notification device 42 located at those bus stops. In other words, the predicted arrival time information 473 is created as individually different information only for the bus stops where it is necessary.

[0559] The above describes the configuration and functions of the arrival time notification system 40 in the fourth embodiment. Next, the arrival time notification method using the arrival time notification system 40 will be described.

[0560] Figure 44 is a flowchart showing the operation of the notification device 42 in the arrival time notification method.

[0561] When the notification device 42 is started up and begins operation, it enters an operational state that monitors whether or not it is the measurement timing (step S130), whether or not it has received the predicted arrival time information 473 (step S136), and whether or not it has finished (step S139).

[0562] When the notification device 42 is in operation, and time i has elapsed since the last measurement, and the measurement timing has arrived, the CPU 420 determines Yes in step S130. As a result, the wireless communication unit 425 measures the radio wave strength between itself and the wireless in-vehicle device 41 and transmits it to the CPU 420 (data acquisition unit 450). As a result, the data acquisition unit 450 acquires the measured time (time information 176) and radio wave strength (radio wave strength information 177) (step S131).

[0563] Next, the data acquisition unit 450 determines whether the acquired radio wave intensity is reliable by comparing it with a threshold to determine whether it is at a level that can be used for the position estimation process (step S132). For example, even with radio waves used in Wi-Fi HaLow, the amount of change in response to changes in distance becomes small at long distances, and there is a problem that the distance traveled cannot be estimated even if measurements are taken before and after movement. In other words, even if the radio wave intensity is correct, if it is at a level that cannot be used for distance estimation, there is no point in creating measurement information 475. Therefore, if the data acquisition unit 450 determines No in step S132, it skips the processing in steps S133 to S135 and returns to the operational state without creating measurement information 475.

[0564] On the other hand, if the result in step S132 is "Yes", the data acquisition unit 450 creates measurement information 475 based on the acquired time information 176 and radio wave intensity information 177 (step S133) and stores it in the storage device 421. As a result, the data output unit 451 creates output information 474 including the created measurement information 475 (step S134).

[0565] When output information 474 is created, the data output unit 451 controls the communication unit 424 to transmit the output information 474 to the server device 44. As a result, the communication unit 424 transmits the output information 474, including the measurement information 475, to the server device 44 (step S135). Therefore, when the notification device 42 is in operation, radio wave intensity is measured every time i, and the measurement information 475 is transmitted to the server device 44. After step S135 is executed, the notification device 42 returns to operation.

[0566] When the notification device 42 is in operation and receives the predicted arrival time information 473, the CPU 420 determines Yes in step S136. As a result, the communication unit 424 transmits the predicted arrival time information 473 to the CPU 420 (data acquisition unit 450). The data acquisition unit 450, having received the predicted arrival time information 473, stores the transmitted predicted arrival time information 473 as acquired information 472 in the storage device 421.

[0567] Next, the data output unit 451 creates output information 474 that includes the stored predicted arrival time information 473 (step S137). At this time, the data output unit 451 creates the output information 474 so that the notification corresponds to the display capability of the display unit 423. For example, the output information 474 may be a video based on the predicted arrival time information 473.

[0568] When output information 474 is created, the data output unit 451 controls the display unit 423 to display the output information 474. As a result, the display unit 423 displays the predicted arrival time information 473, thereby providing notification (step S138).

[0569] In this way, the arrival time notification system 40 can notify passengers waiting for the bus 9 at the bus stop of the predicted arrival time information 473. Once the notification to the passengers is complete, the notification device 42 returns to the operational state.

[0570] When the notification device 42 determines that the process is complete while in operation, the CPU 420 determines "Yes" in step S139. As a result, the notification device 42 terminates all processing and exits. The decision of whether or not to exit is made based on whether or not a notification of termination has been received from the server device 44.

[0571] Figure 45 is a flowchart showing the operation of the observation device 43 in the arrival time notification method.

[0572] When the observation device 43 is started up and begins operation, it enters a state (operational state) where it monitors whether or not it is time to measure (step S140) and whether or not to terminate (step S146).

[0573] When the observation device 43 is in operation and time i has elapsed since the last measurement, and the measurement timing has arrived, the CPU 430 determines Yes in step S140. As a result, the wireless communication unit 435 measures the radio wave strength between itself and the wireless vehicle-mounted device 41 and transmits it to the CPU 430 (data acquisition unit 452). As a result, the data acquisition unit 452 acquires the measured time (time information 176) and radio wave strength (radio wave strength information 177) (step S141).

[0574] Next, the data acquisition unit 452 determines whether the acquired radio wave intensity is reliable by comparing it with a threshold to determine whether it is at a level that can be used for the position estimation process (step S142).

[0575] Then, if the data acquisition unit 450 determines No in step S142, it skips the processing in steps S143 to S145 and returns to the operational state without creating the measurement information 475.

[0576] On the other hand, if the result in step S142 is "Yes", the data acquisition unit 452 creates measurement information 475 based on the acquired time information 176 and radio wave intensity information 177 (step S143) and stores it in the storage device 431. As a result, the data output unit 453 creates output information 477 including the created measurement information 475 (step S144).

[0577] When output information 477 is created, the data output unit 453 controls the communication unit 434 to transmit the output information 477 to the server device 44. As a result, the communication unit 434 transmits the output information 477, including the measurement information 475, to the server device 44 (step S145). Therefore, when the observation device 43 is in operation, radio wave intensity measurements are performed every time i, and the measurement information 475 is transmitted to the server device 44. After step S145 is executed, the notification device 42 returns to operation.

[0578] When the observation device 43 determines that it has finished operating, the CPU 430 determines "Yes" in step S146. As a result, the observation device 43 terminates all processing and shuts down. The decision of whether or not to terminate is made based on whether or not a notification to terminate has been received from the server device 44.

[0579] Figures 46 and 47 show the operation of the server device 44 in the arrival time notification method. It is assumed that the necessary setting information 480 has been stored in the storage device 441 of the server device 44 before the processing shown in Figures 46 and 47 begins. In other words, it is assumed that the process by which the data acquisition unit 454 acquires the setting information 480 has been completed.

[0580] When the processing shown in Figures 46 and 47 is started, the server device 44 enters a state (hereinafter referred to as the "monitoring state") where it monitors whether or not it has received measurement information 475 (step S151) and whether or not to terminate the process (step S157).

[0581] In the monitoring state, when the communication unit 444 receives the measurement information 475, the server device 44 (CPU 440) determines Yes in step S151. Then, the communication unit 444 transmits the received measurement information 475 to the history acquisition unit 456.

[0582] When measurement information 475 is transmitted, the history acquisition unit 456 refers to the transmitted measurement information 475 and identifies the source of the measurement information 475, thereby identifying the history information 175 corresponding to that source (step S152).

[0583] When the history information 175 is identified, the history acquisition unit 456 creates a new record of the identified history information 175 (i.e., the history information 175 of the device that transmitted the received measurement information 475) (step S153).

[0584] Next, the history acquisition unit 456 stores the time information 176 and radio wave intensity information 177 contained in the measurement information 475 in the record newly created in step S153 (step S154). In this way, the radio wave intensity measured by the notification device 42 and the observation device 43, and the time at which the radio wave intensity was measured, are recorded in the history information 175.

[0585] Furthermore, the processing in steps S152 to S154 is performed for all received measurement information 475. This allows the server device 44 to record all radio wave intensity measured by the arrival time notification system 40 and the time at which the radio wave intensity was measured.

[0586] In the following explanation, until step S156 is completed, the device that transmits the measurement information 475 will be referred to as the "device to be processed," and the new record created in step S153 will be referred to as the "record to be processed." Furthermore, the record immediately preceding the record to be processed by the device to be processed will be referred to as the "comparison record." That is, if the record to be processed is the record at time T, then the record at time (Ti) will be referred to as the "comparison record."

[0587] When the processing in step S154 is completed, the server device 44 performs radio wave intensity correction processing (step S155). In the fourth embodiment, the radio wave intensity correction processing is a process in which the intensity correction unit 459 stores the corrected radio wave intensity information 179 in the processing target record of the processing target device.

[0588] Figure 48 is a flowchart showing the radio wave intensity correction process in the fourth embodiment.

[0589] When the radio wave intensity correction process is started, the intensity correction unit 459 acquires the radio wave intensity information 177 stored in the record to be processed as the radio wave intensity to be corrected (step S170).

[0590] Next, the intensity correction unit 459 determines whether the record to be processed is the first record (step S171). The process in step S171 can be performed, for example, in the same way as in step S12.

[0591] The case where step S171 is determined to be Yes will be explained. In step S171, it is determined to be Yes when the record to be processed is the first record. In this case, the server device 44 obtains the predicted radio wave intensity by having the intensity prediction unit 458 calculate the predicted radio wave intensity based on the position of the bus 9 (step S172).

[0592] The calculation performed by the intensity prediction unit 458 will be described later, but at this time, the intensity prediction unit 458 obtains the position of the bus 9 by obtaining position information 180 from history information 175 other than the processing target device.

[0593] When step S172 is completed, step S176 determines whether the radio wave strength information 177 of the record to be processed is within the range, based on the predicted radio wave strength information 178 obtained in step S172. Note that the processing in step S176 can be performed in the same way as in step S17.

[0594] On the other hand, if step S171 determines No (i.e., the record to be processed is not the first record), the intensity correction unit 459 obtains the predicted radio wave intensity information 178 and radio wave intensity information 177 stored in the comparison record (step S173). Note that if the time information 176 of the record to be processed is "time T", then the time information 176 of the comparison record, which is the immediately preceding record, is "time (Ti)".

[0595] The predicted radio wave strength information 178 stored in the comparison record is information that predicted the radio wave strength to be measured this time at the time of the previous measurement. In other words, the predicted radio wave strength information 178 obtained in step S173 is information that predicts the radio wave strength information 177 of the record to be processed.

[0596] When the processing in step S173 is completed, the intensity correction unit 459 calculates the change in radio wave intensity during time i based on the corrected radio wave intensity information 179 of the comparison record (a value obtained by correcting the radio wave intensity measured at time (Ti)) and the radio wave intensity information 177 of the processing record (a radio wave intensity measured at time T) (step S174).

[0597] Next, the intensity correction unit 459 determines whether the amount of change obtained in step S174 is appropriate (step S175). In the fourth embodiment, it is assumed that the travel path of the bus 9 includes not only separation sections but also approach sections. In other words, the arrival time notification system 40 in the fourth embodiment is designed to handle routes in which separation sections and approach sections are mixed.

[0598] Therefore, in the fourth embodiment, the intensity correction unit 459 determines whether the radio wave strength has increased further if the current position of the bus 9 is in a separated section of the path, and determines that it is inappropriate if the radio wave strength has increased despite being in a separated section. In other words, the radio wave strength measured this time (radio wave strength information 177 of the record to be processed) is considered unreliable and inappropriate. In such cases, the intensity correction unit 459 determines No in step S175.

[0599] Furthermore, the intensity correction unit 459 determines whether the radio wave strength has decreased further if the current location of bus 9 is in an approach section of the route, and if it has decreased despite being in an approach section, it determines that it is inappropriate. In other words, the radio wave strength measured this time (radio wave strength information 177 of the record to be processed) is considered unreliable and inappropriate. In such cases as well, the intensity correction unit 459 determines No in step S175.

[0600] If the amount of change is inappropriate (No in step S175), the intensity correction unit 459 considers the radio wave intensity information 177 of the record to be processed to be unreliable and discards it, and acquires corrected radio wave intensity information 179 as the corrected radio wave intensity using the acquired predicted radio wave intensity (step S178). In other words, the current radio wave intensity is corrected to the predicted radio wave intensity.

[0601] When step S178 is executed and the corrected radio wave intensity information 179 is acquired, the intensity correction unit 459 stores the acquired corrected radio wave intensity information 179 in the processing target record of the history information 175 (step S179).

[0602] When step S179 is executed, the arrival time notification system 40 in the fourth embodiment finishes the radio wave intensity correction process (step S155) and returns to the process shown in Figure 46.

[0603] Returning to the process in step S175, if the amount of change is appropriate (Yes in step S175), the intensity correction unit 459 determines whether the radio wave intensity information 177 of the record to be processed is within the range according to the predicted radio wave intensity information 178 acquired in step S173 (step S176). Note that the process in step S176 can be performed in the same way as in step S17, so a detailed explanation is omitted.

[0604] If the result in step S176 is "Yes", the intensity correction unit 459 determines that the radio wave intensity information 177 of the record to be processed is reliable. In this case, the corrected radio wave intensity information 179 is obtained using the radio wave intensity obtained in step S170 (the radio wave intensity information 177 of the record to be processed) as the corrected radio wave intensity (step S177).

[0605] However, if step S176 determines No, the intensity correction unit 459 determines that the radio wave intensity information 177 of the record to be processed is unreliable and executes step S178, which has already been described.

[0606] In the arrival time notification system 40 of the fourth embodiment, the execution of step S178 corresponds to a correction being performed to replace the unreliable radio wave strength (measured value) with the predicted radio wave strength (predicted value). However, the correction method is not limited to this. For example, a correction value may be calculated by weighting it according to the value of the deviation from the predicted radio wave strength (prediction error Q), and the correction may be made by adding this correction value to the radio wave strength.

[0607] Thus, in the fourth embodiment, the intensity correction unit 459 corrects the radio wave intensity information 177 included in the history information 175 according to the predicted radio wave intensity information 178 to obtain corrected radio wave intensity information 179, and stores it in the history information 175. Therefore, for example, by creating predicted radio wave intensity information 178 that suppresses the influence of events other than the terminal distance CD between the wireless vehicle-mounted device 41 and the communication terminal device (notification device 42 or observation device 43), the influence of events other than the terminal distance CD between the wireless vehicle-mounted device 41 and the communication terminal device on the radio wave intensity information 177 can be suppressed.

[0608] Once step S177 or step S178 is executed, as already described, the intensity correction unit 459 executes step S179, terminates the radio wave intensity correction process (step S155), and returns to the process shown in Figure 46.

[0609] When the process in step S155 is completed and the system returns to Figure 46, the arrival time notification system 40 performs radio wave intensity prediction processing (step S156).

[0610] Figure 49 is a flowchart showing the radio wave intensity prediction process in the fourth embodiment. When the radio wave intensity prediction process is started, the intensity prediction unit 458 acquires the corrected radio wave intensity information 179 stored in the record to be processed (step S181).

[0611] In the arrival time notification system 40 of the fourth embodiment, when the radio wave intensity prediction process (step S156) is executed, step S155 (step S179) has already been executed, and the corrected radio wave intensity information 179 has already been stored in the record to be processed. Therefore, at the time step S181 is executed, the intensity prediction unit 458 can acquire the corrected radio wave intensity information 179 stored in the record to be processed.

[0612] Next, the intensity prediction unit 458 determines whether the record to be processed is the first record (step S182). The process in step S182 can be performed, for example, in the same way as the process in step S171.

[0613] When the first record is created, the location information 180 is not stored in the history information 175 of the device to be processed. Therefore, if the record to be processed is the first record (Yes in step S182), the location identification unit 460 obtains the location information 180 at time T and the location information 180 at time (Ti) from the history information 175 of a device other than the device to be processed (any device that stores the location information 180 is acceptable, but more preferably a candidate communication terminal device). Then, the location identification unit 460 stores the location information 180 at time T in the record to be processed in the history information 175 of the device to be processed (step S183). As a result, the current location of bus 9 is stored in the record to be processed.

[0614] On the other hand, if step S182 determines No (if the record to be processed is not the first record), the location identification unit 460 obtains the location PO(T) and stores it as location information 180 in the record to be processed (history information 175) (step S184).

[0615] The process of step S184 will now be explained in detail. First, the location identification unit 460 determines the terminal distance CD using the model information 288 based on the acquired corrected radio wave strength information 179. In the fourth embodiment, the model information 288 is information that shows the relationship between the terminal distance CD and the radio wave strength. Therefore, the location identification unit 460 can determine the current terminal distance CD(T) using the model information 288 based on the corrected radio wave strength information 179 (which can be considered as the radio wave strength at time T). By using the model information 288 in this way, the terminal distance CD(T) can be determined with high accuracy while conforming to environmental conditions and suppressing the effects of multipath and other factors.

[0616] Once the terminal distance CD(T) is determined, the distance traveled along the path up to the present can be determined using the relationship between the terminal distance CD and the distance traveled along the path, as shown in Figure 18, and the position PO(T) can be determined. In this way, the position identification unit 460 can execute the process of step S184. Note that there may be multiple points along the path with the same terminal distance CD (such a path is assumed; see Figure 18). However, although the details are omitted, it is possible to determine which of these locations is appropriate as the current position from the movement history of the moving object up to the present (for example, past position information 180).

[0617] When the processing in step S183 or step S184 is completed, the position identification unit 460 determines the travel distance along the path from position PO(Ti) to position PO(T) based on the path information 481 (step S185). The travel distance determined in step S185 is the travel distance of the bus 9 from time (Ti) to time T.

[0618] Furthermore, if step S183 is executed before step S185, the location identification unit 460 has already obtained the location PO(Ti) from a record other than the device to be processed in step S183. Also, if step S184 is executed before step S185, the location identification unit 460 obtains the location PO(T+i) from the comparison record of the device to be processed in step S185.

[0619] Next, the positioning unit 460 calculates the average speed of the bus 9 from time (Ti) to time T by dividing the distance traveled in step S185 by time i (step S186). Strictly speaking, the speed calculated here is the average speed of the bus 9 from time (Ti) to time T, but if time i is considered to be sufficiently short, the speed can be considered constant.

[0620] The positioning unit 460 calculates the distance the bus 9 will travel (predicted distance traveled) from the velocity obtained in step S186 to time (T+i) (product of velocity and time i) (step S187).

[0621] Once the predicted travel distance is determined by the process in step S187, the position determination unit 460 predicts the position PO(T+i) of bus 9 at time (T+i) by moving along the path by the determined predicted travel distance based on the path information 481.

[0622] Then, once the position PO(T+i) is determined, the intensity prediction unit 458 uses the position PO(T+i) and the model information 288 to determine the radio wave intensity at time (T+i) (i.e., the predicted radio wave intensity) and obtains the predicted radio wave intensity information 178 (step S188).

[0623] When step S188 is executed and the predicted radio wave intensity information 178 is acquired, the intensity prediction unit 458 stores the acquired predicted radio wave intensity information 178 in the processing target record of the history information 175 (step S189).

[0624] Furthermore, when step S189 is executed, the arrival time notification system 40 terminates the radio wave intensity prediction process (step S156) and returns to the process shown in Figure 46.

[0625] When step S156 is completed and the system returns to Figure 46, the server device 44 determines whether the measurement is complete or not (Figure 47: step S161).

[0626] Step S161 can be determined, for example, by whether or not measurement information 475 at time T has been received from all notification devices 42 and all observation devices 43. However, it is not practical to wait for reports from all communication terminal devices. For example, step S161 may be determined as Yes when measurement information 475 has been received from all target communication terminal devices. Alternatively, the server device 44 may keep track of the notification devices 42 and observation devices 43 with valid radio wave intensity levels at position PO(Ti), and determine as Yes in step S161 when it receives measurement information 475 from those devices.

[0627] Once all measurement information 475 has been received from the devices that are supposed to receive measurement information 475 (Yes in step S161), the device identification unit 457 compares the corrected radio wave intensity information 179 of all devices that were able to receive measurement information 475 at time T and identifies the device with the largest value (step S162).

[0628] Once the device with the highest corrected radio wave strength information 179 is identified, the device identification unit 457 determines whether the identified device is the current target communication terminal device (step S163). If the answer in step S163 is No, the target communication terminal device is switched to the device identified in step S162 (step S164). On the other hand, if the answer in step S163 is No, there is no need to switch the target communication terminal device, so the process in step S163 is skipped.

[0629] If the system determines Yes in step S163 or executes step S164, the arrival time notification system 40 performs particle filtering (step S165). The particle filtering process shown in step S165 is a process in which the position identification unit 460 uses a particle filter to determine the position of the bus 9.

[0630] Figure 50 is a flowchart showing the particle filtering process in the fourth embodiment.

[0631] When particle filtering is started, the positioning unit 460 determines whether the record to be processed is the first record (step S191). The process in step S191 can be performed, for example, in the same way as in step S12.

[0632] If the answer in step S191 is Yes, the positioning unit 460 uses the initial distribution information 483 to generate a predetermined number of particles within the path (state space) (step S192).

[0633] As already explained, the position identification unit 460 in the fourth embodiment uses initial distribution information 483 to distribute particles so that they are concentrated near the starting position. Therefore, the particle distribution immediately after the start will be, for example, as shown in Figure 28. When step S192 is completed, the arrival time notification system 40 finishes the particle filtering process and returns to the process shown in Figure 47.

[0634] Note that when step S192 is executed, it means that preparations for particle filtering have been made, and the position of the moving object is not determined at this stage.

[0635] On the other hand, if No is determined in step S191 (when the record to be processed is not the first record), the position identification unit 460 determines the amount of change between the corrected radio wave intensity information 179 acquired at time T and the corrected radio wave intensity information 179 acquired at time (Ti) (step S193).

[0636] Then, the positioning unit 460 predicts the amount of change in radio wave intensity between time T and time (T+i) based on the velocity, and generates a predicted sample at time (T+i) (step S194).

[0637] As for methods of predicting the amount of change, for example, the velocity can be considered constant, and the amount of change can be assumed to be constant for each time interval i. Alternatively, the amount of change up to now can be determined from the historical information 175, and if the recent trend is increasing, it can be increased, and if the recent trend is decreasing, it can be decreased.

[0638] Next, the positioning unit 460 acquires corrected radio wave intensity information 179 for time (T+i), and uses the corrected radio wave intensity information 179 and the predicted samples generated in step S194 to calculate a weight for each particle using a likelihood function (step S195).

[0639] Note that the actual processing using particle filters is divided into pre-observation processing and post-observation processing at time (T+i), and since the explanation (flowchart) becomes complicated when paralleled with the radio wave intensity correction processing, only a conceptual explanation will be given here. The specific algorithm for particle filters can be realized by appropriately applying conventional technologies. For example, technologies described in Japanese Patent Publication No. 2010-239331 (Patent No. 5240691) and Japanese Patent Publication No. 2018-169310 (Patent No. 6730953) can be applied.

[0640] In this case, the position identification unit 460 in the fourth embodiment determines the weight of each particle using the likelihood function information 373 selected by the operating condition information 371. Therefore, since the calculation can be performed using a likelihood function corresponding to the conditions when the moving object is operating, the accuracy is improved.

[0641] When step S195 is executed, the position determination unit 460 estimates the position of the particle with the maximum weight as the position of the moving object (step S196).

[0642] The location identification unit 460 acquires the location determined in step S196 as new location information 180 and stores it in the history information 175 (step S197).

[0643] Thus, in the fourth embodiment, the positioning unit 460 uses a particle filter to determine the position of the moving object, thereby improving accuracy compared to determining the position solely from radio wave intensity.

[0644] Once the position of the moving object is determined, the positioning unit 460 resamples the particles according to the determined weights (step S198). Specifically, it increases the number of particles around the weighted particles and decreases the number of particles far from the weighted particles. At this time, the positioning unit 355 moves particles that are located behind the previous position of the moving object to time T. This is because if the moving object were to move to a position behind the previous position of the moving object (towards the starting point), it would mean that it traveled in reverse along its path, which does not meet the preconditions, and therefore such particles are considered unreliable.

[0645] Furthermore, in a particle filter, the number of particles must be kept constant, so if particles are deleted, the same number of particles must be repositioned at other locations. In other words, the process is equivalent to moving the particles. Specifically, in the fourth embodiment, after resampling, particles remaining behind position T are moved to position T. Note that the weight of the particles after resampling is constant, and since this is done after the position of the moving object has been determined, it is considered that there is no effect on position determination. In addition, due to the characteristic that particles at distant positions are deleted each time the moving object moves, particles do not accumulate at position T.

[0646] Once resampling is complete, the arrival time notification system 40 terminates the particle filtering process shown in step S165 and returns to the process shown in Figure 47.

[0647] When the process shown in step S165 is completed and the process in Figure 47 is returned, the arrival time notification system 40 extracts the notification devices 42 that have not yet arrived (step S166).

[0648] An unarrived notification device 42 is a notification device 42 located at a bus stop where bus 9 has not yet arrived. This is because it is meaningful to inform passengers in the vicinity of these devices of the arrival time. In step S166, even if there are multiple unarrived notification devices 42, all of them will be listed (extracted) in step S166.

[0649] For one of the notification devices 42 extracted in step S166, the time prediction unit 461 predicts the arrival time (step S167).

[0650] In step S167, first, the speed of the bus 9 is determined based on position PO(Ti) and position PO(T), similar to step S186. Next, the remaining distance to the bus stop where the notification device 42 is located is determined based on position PO(T), and the time required to reach the bus stop is calculated by dividing this distance by the previously determined speed. Adding the time required to time T gives the predicted arrival time. Alternatively, the time required may be used as the predicted arrival time.

[0651] Once the predicted arrival time is determined, the time prediction unit 461 creates output information 479 that includes the predicted arrival time information 473. Then, the data output unit 455 controls the communication unit 444 to transmit the created output information 479 to the notification device 42. As a result, the output information 479 including the predicted arrival time information 473 is transmitted to the notification device 42 (step S168).

[0652] As already explained, the notification device 42, upon receiving output information 479 including predicted arrival time information 473, notifies passengers by displaying (outputting) the predicted arrival time information 473 on the display unit 423.

[0653] When step S168 is completed, the time prediction unit 461 determines whether or not the transmission of predicted arrival time information 473 has been completed for all of the notification devices 42 that were extracted in step S166 and for which the bus 9 has not yet arrived (step S169). If there are still notification devices 42 among the extracted notification devices 42 for which the processing in steps S167 and S168 has not been completed (No in step S169), the process returns to step S167 and is repeated in order to complete the processing in steps S167 and S168 for those devices. On the other hand, if the transmission of predicted arrival time information 473 has been completed for all of the extracted notification devices 42 (Yes in step S169), the arrival time notification system 40 returns to the monitoring state again (Figure 46: step S151).

[0654] In the monitoring state, if the system determines "Yes" in step S157, the arrival time notification system 40 sends a completion notification to the notification device 42 and the observation device 43 (step S158), and terminates the process.

[0655] As described above, the arrival time notification system 40, which notifies predicted arrival time information 473 indicating the time when a moving object moving along a travel path is expected to arrive at its destination, comprises a wireless vehicle-mounted device 41 (mobile communication terminal device) mounted on the moving object, notification devices 42 and observation devices 43 (communication terminal devices) installed near the destination and communicating wirelessly with the wireless vehicle-mounted device 41, a data acquisition unit 454 that acquires terminal location information 482 indicating the location of the notification devices 42 and observation devices 43, a data acquisition unit 454 that acquires route information 481 indicating the travel path, and notification The system includes wireless communication units 425 and 435 that acquire radio wave strength between the device 42 and observation device 43 and the wireless vehicle-mounted device 41; a position identification unit 460 that identifies the position of a moving object based on the radio wave strength acquired by the wireless communication units 425 and 435 and route information 481; a time prediction unit 461 that calculates predicted arrival time information 473 based on the position of the moving object identified by the position identification unit 460, route information 481 and terminal position information 482; and a display unit 423 that notifies by outputting the predicted arrival time information 473 predicted by the time prediction unit 461. This makes it possible to notify the predicted arrival time without using GPS.

[0656] Furthermore, wireless communication offers low-power, long-range communication. This allows it to accommodate typical movement routes of mobile objects.

[0657] Furthermore, the mobile entity is a bus that carries passengers, and the notification device 42 is installed at the bus stop. Since the bus stop is the destination of the bus, the notification device 42 can be effectively positioned.

[0658] Furthermore, the observation device 43 is installed on utility poles located along the travel route. Utility poles are highly likely to be located along the travel route. Therefore, the observation device 43 can be effectively positioned.

[0659] Furthermore, the arrival time notification system 40 further includes a history acquisition unit 456 that acquires history information 175 by associating time information 176 obtained by the wireless communication units 425 and 435 with the radio wave strength information 177; an intensity prediction unit 458 that acquires predicted radio wave strength information 178 by predicting the radio wave strength information 177 to be acquired next based on the history information 175; and an intensity correction unit 459 that acquires corrected radio wave strength information 179 by correcting the radio wave strength information 177 included in the history information 175 according to the predicted radio wave strength information 178. The position identification unit 460 identifies the position of the moving object based on the corrected radio wave strength information 179 acquired by the intensity correction unit 459 instead of the radio wave strength information 177 acquired by the wireless communication units 425 and 435. This makes it possible to suppress the influence of events other than the distance between the mobile communication terminal device and the communication terminal device on the radio wave strength.

[0660] <5. Variant> Although embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and various modifications are possible.

[0661] For example, the steps shown in the above embodiment are merely illustrative and are not limited to the order or content shown above. In other words, the order and content may be changed as appropriate if similar effects can be obtained. For example, in the server device 24 of the second embodiment, the step of acquiring the model database 289 (step S51) and the step of acquiring the route information 286 (step S52) may be swapped.

[0662] Furthermore, some or all of the functional blocks shown in the above embodiment may be configured with dedicated logic circuits. For example, although the intensity prediction unit 153 and the intensity correction unit 154 were described as being implemented in software by the CPU 120 operating according to the program 812, they may also be implemented in hardware. [Explanation of Symbols]

[0663] 10,20,30 Radio wave intensity correction system 11 Mobile communication terminal equipment 110,120,220,240,410,420,430,440 CPU 111,121,221,241,411,421,431,441 Storage device 112,122,222,242,412,422,432,442 Operation section 113,123,223,243,413,423,433,443 Display section 224,244,424,434,444 Communications Department 115, 125, 225, 415, 425, 435 Wireless Communication Section 12,22,23,32,33 Communication terminal equipment 150,250,253,350,450,452,454 Data acquisition unit 151,251,254,351,453,451,455 Data output section 152,255,456 History acquisition unit 153,256,353,458 Intensity prediction unit 154,257,459 Strength correction section 155,258,355,460, Location identification part 170,181,281,284,470,472,476,478 Acquisition information 171,182,282,285,471,474,477,479 Output Information 175 History Information 176,276 time information 177,277 Radio wave strength information 178 Predicted radio wave strength information 179 Corrected radio wave strength information 180,380 Location information 24,44 Server devices 252,457 Device identification part 259 Model Acquisition Section 283,475 measurement data 286,481 route information 287,290 Environmental condition information 288 Model Information 289,484 Model Databases 291 Model Candidate Information 356 Likelihood Function Acquisition Section 370,485 Funct...

Claims

1. A radio wave intensity correction system, A mobile communication terminal device mounted on a mobile vehicle, A communication terminal device that performs wireless communication with the aforementioned mobile communication terminal, A strength acquisition means for acquiring the radio wave strength between the mobile communication terminal device and the communication terminal device, A history acquisition means that acquires history information relating the time when the radio wave intensity was acquired by the intensity acquisition means and the radio wave intensity, An intensity prediction means for obtaining a predicted radio wave intensity by predicting the radio wave intensity to be acquired next time based on the aforementioned historical information, An intensity correction means for obtaining a corrected radio wave intensity by correcting the radio wave intensity included in the historical information according to the predicted radio wave intensity, A radio wave intensity correction system equipped with the following features.

2. A radio wave intensity correction system according to claim 1, The system further includes a route acquisition means for acquiring route information indicating the route of the moving object, The intensity prediction means is a radio wave intensity correction system that acquires the predicted radio wave intensity based on the path information.

3. A radio wave intensity correction system according to claim 2, The route information includes starting position information indicating the position of the mobile body when the wireless communication between the communication terminal device and the mobile communication terminal device is initiated, and ending position information indicating the position of the mobile body when the wireless communication between the communication terminal device and the mobile communication terminal device is terminated. The route acquisition means approximates the route of the moving object based on the starting point position information and the ending point position information. The intensity prediction means is a radio wave intensity correction system that acquires the predicted radio wave intensity based on the approximately determined path.

4. A radio wave intensity correction system according to claim 1, The system further includes a model acquisition means for acquiring model information showing the relationship between the distance between the communication terminal device and the mobile communication terminal device and the radio wave intensity of the wireless signal. The intensity prediction means is a radio wave intensity correction system that acquires the predicted radio wave intensity based on the model information.

5. A radio wave intensity correction system according to claim 4, The aforementioned model acquisition means is a radio wave intensity correction system that acquires a plurality of model candidate information associated with environmental conditions and determines the model information from the plurality of model candidate information according to the environmental conditions.

6. A radio wave intensity correction system according to claim 5, The aforementioned environmental conditions include at least one of the following: day of the week, time of day, weather, region, season, distinction between indoors and outdoors, type of the moving object, surrounding environment of the moving object, and distinction of route.

7. A radio wave intensity correction system according to claim 1, The device further comprises a device identification means for identifying a target communication terminal device from among the multiple communication terminal devices by comparing the radio wave intensity of the wireless signal between the multiple communication terminal devices and the mobile communication terminal device. The intensity prediction means acquires the predicted radio wave intensity between the target communication terminal device and the mobile communication terminal device. The intensity correction means is a radio wave intensity correction system that acquires the corrected radio wave intensity between the target communication terminal device and the mobile communication terminal device.

8. A radio wave intensity correction system according to claim 1, The system further comprises a server device capable of data communication with the aforementioned communication terminal device, The aforementioned intensity correction means is a radio wave intensity correction system provided in the server device.

9. A radio wave intensity correction system according to any one of claims 1 to 8, A radio wave intensity correction system further comprising positioning means for determining the position of the moving object based on the corrected radio wave intensity.

10. A radio wave intensity correction system according to claim 9, The aforementioned position determination means is a radio wave intensity correction system that determines the position using a particle filter.

11. A radio wave intensity correction system according to claim 10, A radio wave intensity correction system in which the radio wave intensity at time T and the change in radio wave intensity at time (T-i) are used as the likelihood of the particle filter.

12. A radio wave intensity correction system according to claim 10, The position determination means is a radio wave intensity correction system that moves particles that are distributed at a position behind the position of the moving object predicted before time (T+i) from a sample predicted at time (T+i).

13. A radio wave intensity correction system according to claim 10, A storage means that stores multiple candidate likelihood function information, each associated with operating condition information, The system includes an operating condition acquisition means for acquiring the aforementioned operating condition information, The position identification means is a radio wave intensity correction system that, in accordance with the operating condition information acquired by the operating condition acquisition means, identifies one likelihood function candidate information from among the plurality of likelihood function candidate information, and calculates the weight of each particle using the identified likelihood function candidate information as likelihood function information.

14. A radio wave intensity correction system according to claim 13, The aforementioned operating condition information includes at least one of the following: day of the week, time, weather, region, season, distinction between indoor and outdoor, type of mobile object, surrounding environment of the mobile object, and distinction of route.

15. A radio wave intensity correction system according to claim 10, The position determination means is a radio wave intensity correction system that uses initial distribution information in which particles are biased towards the vicinity of the starting position of the moving object.

16. A radio wave intensity correction system according to claim 9, The system comprises multiple communication terminal devices, The position of the moving body identified by the position identification means of the communication terminal device 1, A radio wave intensity correction system that determines the position of a moving object based on the position of the moving object determined by the position determination means of another communication terminal device.

17. A mobile communication terminal device mounted on the mobile body communicates wirelessly with a communication terminal device installed on the outside of the mobile body, Strength acquisition means for acquiring the radio wave strength of the wireless signal between the communication terminal device and the other party, A history acquisition means that acquires history information relating the time when the radio wave intensity was acquired by the intensity acquisition means and the radio wave intensity, An intensity prediction means for obtaining a predicted radio wave intensity by predicting the radio wave intensity to be acquired next time based on the aforementioned historical information, An intensity correction means for obtaining a corrected radio wave intensity by correcting the radio wave intensity included in the historical information according to the predicted radio wave intensity, A mobile communication terminal device equipped with the following features.

18. A communication terminal device that performs wireless communication with a mobile communication terminal device mounted on a mobile vehicle, Strength acquisition means for acquiring the radio wave strength of the wireless signal between the mobile communication terminal device and the other party, A history acquisition means that acquires history information relating the time when the radio wave intensity was acquired by the intensity acquisition means and the radio wave intensity, An intensity prediction means for obtaining a predicted radio wave intensity by predicting the radio wave intensity to be acquired next time based on the aforementioned historical information, An intensity correction means for obtaining a corrected radio wave intensity by correcting the radio wave intensity included in the historical information according to the predicted radio wave intensity, A communication terminal device equipped with the following features.

19. A computer-readable program for correcting the radio wave intensity using a mobile communication terminal device mounted on a mobile device and a communication terminal device that communicates wirelessly with the mobile communication terminal, wherein the execution of the program by the computer involves the computer, A strength acquisition means for acquiring the radio wave strength between the mobile communication terminal device and the communication terminal device, A history acquisition means that acquires history information relating the time when the radio wave intensity was acquired by the intensity acquisition means and the radio wave intensity, An intensity prediction means for obtaining a predicted radio wave intensity by predicting the radio wave intensity to be acquired next time based on the aforementioned historical information, An intensity correction means for obtaining a corrected radio wave intensity by correcting the radio wave intensity included in the historical information according to the predicted radio wave intensity, A program that makes a computer function as one equipped with [a certain feature].

20. A radio wave intensity correction method for correcting the radio wave intensity using a mobile communication terminal device mounted on a mobile device and a communication terminal device that communicates wirelessly with the mobile communication terminal, A step of acquiring the radio wave strength between the mobile communication terminal device and the communication terminal device using strength acquisition means, A step of acquiring historical information by a history acquisition means that associates the time at which the radio wave intensity was acquired by the intensity acquisition means with the radio wave intensity, A step of obtaining predicted radio wave intensity by intensity prediction means by predicting the radio wave intensity to be acquired next time based on the aforementioned history information, A step of obtaining corrected radio wave intensity by strength correction means by correcting the radio wave intensity included in the historical information according to the predicted radio wave intensity, A radio wave intensity correction method having the following characteristics.

21. An arrival time notification system that notifies the predicted arrival time, which indicates the time when a moving object traveling along a route is expected to arrive at its destination, A mobile communication terminal device mounted on the aforementioned mobile body, A communication terminal device installed near the aforementioned destination and performing wireless communication with the aforementioned mobile communication terminal device, A terminal location acquisition means for acquiring terminal location information indicating the location of the aforementioned communication terminal device, A means for acquiring movement path information that indicates the aforementioned movement path, A strength acquisition means for acquiring the radio wave strength between the communication terminal device and the mobile communication terminal device, A position determination means that determines the position of the moving object based on the radio wave intensity obtained by the intensity acquisition means and the movement path information, A time prediction means for determining the predicted arrival time based on the position of the moving body identified by the position identification means, the movement path information, and the terminal position information, An output means that notifies by outputting the predicted arrival time predicted by the time prediction means, An arrival time notification system equipped with [features / equipment].

22. The arrival time notification system according to claim 21, The aforementioned wireless communication is a low-power, long-distance communication system for notifying arrival times.

23. The arrival time notification system according to claim 21, The aforementioned mobile vehicle is a bus that operates carrying passengers. The aforementioned communication terminal device is an arrival time notification system installed at the bus stop.

24. The arrival time notification system according to claim 21, The aforementioned communication terminal device is an arrival time notification system installed on a utility pole along the aforementioned travel route.

25. An arrival time notification system according to any one of claims 21 to 24, A history acquisition means that acquires history information relating the time when the radio wave intensity was acquired by the intensity acquisition means and the radio wave intensity, An intensity prediction means for obtaining a predicted radio wave intensity by predicting the radio wave intensity to be acquired next time based on the aforementioned historical information, An intensity correction means for obtaining a corrected radio wave intensity by correcting the radio wave intensity included in the historical information according to the predicted radio wave intensity, Furthermore, The position determination means is an arrival time notification system that determines the position of the moving object based on the corrected radio wave intensity obtained by the intensity correction means, instead of the radio wave intensity obtained by the intensity acquisition means.

26. A mobile communication terminal device mounted on a moving object that moves along a travel path, Wireless communication means for wirelessly communicating with a communication terminal device installed near the destination of the aforementioned mobile object, A terminal location acquisition means for acquiring terminal location information indicating the location of the aforementioned communication terminal device, A means for acquiring movement path information that indicates the aforementioned movement path, A strength acquisition means for acquiring the radio wave strength between the communication terminal device and the mobile communication terminal device, A position determination means that determines the position of the moving object based on the radio wave intensity obtained by the intensity acquisition means and the movement path information, A time prediction means for determining the predicted arrival time based on the position of the moving body identified by the position identification means, the movement path information, and the terminal position information, The wireless communication means is a mobile communication terminal device that outputs the predicted arrival time obtained by the time prediction means to the communication terminal device.

27. A communication terminal device installed near the destination of a mobile object moving along a travel path, Wireless communication means for performing wireless communication with a mobile communication terminal device mounted on the aforementioned mobile body, A terminal location acquisition means for acquiring terminal location information indicating the location of the aforementioned communication terminal device, A means for acquiring movement path information that indicates the aforementioned movement path, A strength acquisition means for acquiring the radio wave strength between the communication terminal device and the mobile communication terminal device, A position determination means that determines the position of the moving object based on the radio wave intensity obtained by the intensity acquisition means and the movement path information, A time prediction means for determining the predicted arrival time based on the position of the moving body identified by the position identification means, the movement path information, and the terminal position information, An output means that notifies by outputting the predicted arrival time obtained by the time prediction means, A communication terminal device equipped with the following features.

28. A computer-readable program that notifies a predicted arrival time, which indicates the time when a moving object moving along a travel path is expected to arrive at its destination, wherein the execution of the program by the computer involves the computer, A mobile communication terminal device mounted on the mobile body, and a wireless communication means for communicating with a communication terminal device installed near the destination and communicating wirelessly with the mobile communication terminal device, A terminal location acquisition means for acquiring terminal location information indicating the location of the aforementioned communication terminal device, A means for acquiring movement path information that indicates the aforementioned movement path, A strength acquisition means for acquiring the radio wave strength between the communication terminal device and the mobile communication terminal device, A position determination means that determines the position of the moving object based on the radio wave intensity obtained by the intensity acquisition means and the movement path information, A time prediction means for determining the predicted arrival time based on the position of the moving body identified by the position identification means, the movement path information, and the terminal position information, An output means that notifies by outputting the predicted arrival time obtained by the time prediction means, A program that makes a computer function as one equipped with [a certain feature].

29. A mobile communication terminal device mounted on a moving object that moves along a travel path, A communication terminal device installed near the destination of the mobile body and communicating wirelessly with the mobile communication terminal device, An arrival time notification method for notifying an estimated arrival time, which indicates the time when the moving object is expected to arrive at its destination, A step of acquiring terminal location information indicating the location of the aforementioned communication terminal device, A step of acquiring travel path information indicating the aforementioned travel path, A step of acquiring the radio wave strength between the communication terminal device and the mobile communication terminal device, A step of determining the position of the moving object based on the acquired radio wave intensity and the movement path information, A step of determining the predicted arrival time based on the identified location of the moving object, the movement path information, and the terminal location information, The process involves providing notification by outputting the calculated predicted arrival time, A method for notifying arrival time, which includes the following:

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