JP7303166B2 - Navigation device, navigation method and computer program - Google Patents

Description

The present invention relates to a navigation device, navigation method and computer program.

In recent years, a remote monitoring system for remotely monitoring autonomously moving robots by wireless communication has been studied. For example, in Patent Document 1, a robot state monitoring terminal attached to a robot transmits state data of the robot to a monitoring server, and the monitoring server determines the state of the robot based on the state data received from the robot state monitoring terminal. A robot condition monitoring system is described.

JP 2019-209426 A

However, in the robot state monitoring system of Patent Document 1 described above, if wireless communication is cut off while the robot is moving, it becomes impossible to remotely monitor the currently moving robot, which is inconvenient.

SUMMARY OF THE INVENTION The present invention has been made in consideration of such circumstances, and an object of the present invention is to realize stable wireless communication when remotely monitoring a moving object by wireless communication.

(1) One aspect of the present invention indicates a route from a departure point to a destination for a mobile object that communicates with a remote monitoring device that remotely monitors the mobile object via a wireless communication line. A navigation device that provides route information, and for each wireless communication method and radio frequency band in which wireless communication services are provided in a target region, which is the target region for which the route information is provided, locations included in the target region and A location wireless quality storage unit that stores location wireless quality information recorded in association with wireless communication quality at the location; and a plurality of locations stored in the location wireless quality storage unit for each wireless communication system and wireless frequency band. Based on the location wireless quality information corresponding to the wireless communication method and wireless frequency band available to the mobile object among the wireless quality information, the wireless communication quality at the position on the route candidate is evaluated as low if the wireless communication quality is poor. and a route search unit that searches for the route based on the weighting from among the weighted route candidates.
(2) One aspect of the present invention further includes an outdoor population density estimation unit that estimates an outdoor population density, which is the number of people existing outdoors per unit area, for each area in the target area, and the cost The calculation unit is the navigation device according to (1) above, wherein the route candidate is weighted such that the larger the estimated value of the outdoor population density of the area containing the route candidate, the lower the evaluation.
(3) In one aspect of the present invention, the cost calculation unit calculates the route based on at least one of the type of the mobile object and the content of delivery by the mobile object, and the road conditions of the candidate route. The navigation device according to any one of (1) and (2) above, which weights the candidates.
(4) In one aspect of the present invention, when there is a location where wireless communication is likely to be disconnected in the route of the search result, the route search unit outputs wireless disconnection alert information indicating the location. The navigation device according to any one of (1) to (3) above.

(5) One aspect of the present invention indicates a route from a departure point to a destination for a mobile object that communicates via a wireless communication line with a remote monitoring device that remotely monitors the mobile object. A navigation method for providing route information, wherein positions included in the target area are determined for each wireless communication system and radio frequency band in which wireless communication services are provided in the target area for which the route information is provided. a location wireless quality storing step of storing location wireless quality information recorded in association with wireless communication quality at the location in a location wireless quality storage unit; and storing in the location wireless quality storage unit for each wireless communication method and wireless frequency band radio communication at a position on the route for the route candidate based on the position radio quality information corresponding to the radio communication system and radio frequency band available to the mobile object among the plurality of position radio quality information A navigation method comprising: a cost calculation step of weighting such that poor quality results in a low evaluation; and a route searching step of searching for the route based on the weighting from the weighted route candidates. .

(6) An aspect of the present invention indicates a route from a departure point to a destination for a mobile object that communicates with a remote monitoring device that remotely monitors the mobile object via a wireless communication line. Locations included in the target area for each wireless communication system and radio frequency band in which wireless communication services are provided in the target area, which is the target area for which the route information is provided, to the computer of the navigation device that provides the route information. a location wireless quality storage step of storing location wireless quality information recorded in association with the wireless communication quality at the location in a location wireless quality storage unit; Based on the location wireless quality information corresponding to the wireless communication system and the wireless frequency band that can be used by the mobile object among the plurality of stored location wireless quality information, wireless communication at a position on the route candidate for the route candidate is determined. for executing a cost calculation step of weighting such that poor communication quality results in a low evaluation, and a route searching step of searching for the route based on the weighting from among the weighted route candidates; A computer program.

ADVANTAGE OF THE INVENTION According to this invention, the effect that the realization of stable radio|wireless communication can be aimed at is acquired when monitoring a moving body remotely by radio|wireless communication.

1 is a block diagram showing a configuration example of a navigation system according to one embodiment; FIG. FIG. 4 is a diagram illustrating a configuration example of a position/wireless quality storage unit according to one embodiment; 4 is a flowchart illustrating an example procedure of a navigation method according to one embodiment; It is an explanatory view for explaining an example of a route search method. It is an explanatory view for explaining a route search method concerning one embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this embodiment, a navigation system in a delivery service system that performs delivery using a robot that moves autonomously (hereinafter referred to as a mobile robot) will be described as an example.

FIG. 1 is a block diagram showing a configuration example of a navigation system according to one embodiment. In FIG. 1, a mobile robot 2 communicates with a navigation device 4 and a remote monitoring device 20 via a wireless communication line. The mobile robot 2 is an example of a mobile object. The navigation device 4 provides the mobile robot 2 with route information indicating a route from a starting point to a destination.

The remote monitoring device 20 is a device for remotely monitoring the mobile robot 2 by wireless communication. For example, the remote monitoring device 20 receives images captured by the mobile robot 2 and sounds collected from the mobile robot 2 via a wireless communication line, and displays or reproduces the received images and sounds. By viewing the image and the sound, the observer can monitor the movement of the mobile robot 2 in real time. Therefore, in the remote monitoring system according to the present embodiment, realization of stable wireless communication between the mobile robot 2 and the remote monitoring device 20 is required. In this embodiment, the navigation device 4 provides route information for realizing stable wireless communication between the mobile robot 2 and the remote monitoring device 20 .

The configuration of a navigation system 10 according to this embodiment will be described below with reference to FIG.

[User terminal]
The user terminal 1 is a terminal used by a user of the delivery service system according to this embodiment (hereinafter referred to as a delivery service user). A delivery service user designates a destination to which a package is to be delivered and requests delivery. The user terminal 1 may be a mobile communication terminal device such as a smartphone or a tablet computer (tablet PC), or a stationary communication terminal device (for example, a stationary personal computer, etc.). good.

The user terminal 1 has a product ordering unit 101 and a destination information input unit 102 . The product ordering unit 101 selects a product and places an order for the selected product in accordance with an operation by a delivery service user.

The product ordering unit 101 manages the remaining amount of items owned by the delivery service user in real time, and when the remaining amount of items falls below a preset threshold value, the item for replenishment is automatically ordered. You can place an order.

The destination information input unit 102 inputs destination information indicating a destination such as an address when the product ordering unit 101 orders products. The destination information may be specified each time by the delivery service user, or the destination information input unit 102 may record the destination information specified by the delivery service user in the past and input the recorded destination information. It can be reused automatically.

Also, the destination information input unit 102 may use a positioning function based on a GPS (Global Positioning System) provided in the user terminal 1 to set the current position acquired by GPS as the destination. Further, the destination information input unit 102 may add an image of the surrounding scenery of the user terminal 1 captured by the camera of the user terminal 1 to the destination information as reference information of the destination.

[Mobile robot]
The mobile robot 2 is a robot capable of autonomous travel. The mobile robot 2, for example, runs in the city and delivers packages to destinations designated by delivery service users.

The mobile robot 2 includes a current position acquisition unit 201, a wireless quality acquisition unit 202, a state acquisition unit 203, a wireless communication unit 204, a route information storage unit 205, an imaging unit 206, a motion determination unit 207, and a motion determination unit 207. and a control unit 208 .

The current position acquisition unit 201 acquires the current position (position information) using a positioning system such as GPS. The radio quality acquisition unit 202 obtains radio communication quality (radio communication quality information ). The state acquisition unit 203 acquires state data (state information) such as remaining battery level, temperature, and movement speed from various sensors provided in the mobile robot 2 .

The wireless communication unit 204 performs wireless communication with the remote monitoring device 20 and the navigation device 4 . The wireless communication unit 204 supports wireless communication systems such as LTE (Long Term Evolution) and 5G (5th generation mobile communication system), and performs wireless communication via a base station of the wireless communication system that it supports. Further, the wireless communication unit 204 may be compatible with an unlicensed wireless communication method such as Wi-Fi (registered trademark), and perform wireless communication using the unlicensed wireless communication method.

The wireless communication unit 204 transmits the information obtained by the current location acquisition unit 201 , the wireless quality acquisition unit 202 and the state acquisition unit 203 to the operation monitoring unit 401 of the navigation device 4 . Also, the radio communication unit 204 receives the route information transmitted from the route distribution unit 412 of the navigation device 4 and stores it in the route information storage unit 205 . The route information stored in the route information storage unit 205 is used to determine the movement of the mobile robot 2. FIG.

The imaging unit 206 captures an image of the traveling direction of the mobile robot 2 . The motion determination unit 207 determines the next motion of the mobile robot 2 . The motion determination unit 207 uses the current position acquired by the current position acquisition unit 201, the captured image captured by the imaging unit 206, and the like when moving along the route indicated by the route information stored in the route information storage unit 205. Then, the mobile robot 2 determines an operation suitable for the surrounding environment.

The motion control unit 208 causes the mobile robot 2 to execute the motion determined by the motion determination unit 207 . The motion control unit 208 controls the running type and running speed of the mobile robot 2 such as forward movement, backward movement, and right/left turn, and the motion type other than running such as changing the image capturing direction of the image capturing unit 206 .

[mobile terminal]
The mobile terminal 3 is a mobile communication terminal device such as a smart phone or a tablet PC. The mobile terminal 3 may be used as the user terminal 1 or may be separate from the user terminal 1 . As the mobile terminals 3, for example, mobile terminals of all subscribers who have subscribed to a specific wireless communication carrier and who have agreed with the wireless communication carrier to acquire location information may be included.

The mobile terminal 3 periodically reports its current location (location information) and wireless communication quality (wireless communication quality information) at the current location to the navigation device 4 for each wireless communication system and wireless frequency band it supports. .

[Navigation device]
A navigation device 4 navigates one or more mobile robots 2 from a starting point to a destination. Also, the navigation device 4 performs operation monitoring for one or more mobile robots 2 .

The navigation device 4 includes an operation monitoring unit 401, an operation information storage unit 402, a location/wireless quality storage unit 403, a map information storage unit 404, a wireless quality movement cost conversion unit 405, and a mobile terminal location information storage unit 406. , an outdoor population density estimation unit 407 , a travel cost calculation unit 408 , an order information storage unit 409 , a destination acquisition unit 410 , a route search unit 411 , and a route distribution unit 412 . In this embodiment, the radio quality moving cost conversion unit 405 and the moving cost calculation unit 408 correspond to the cost calculation unit.

Each function of the navigation device 4 is realized by the navigation device 4 having computer hardware such as a CPU (Central Processing Unit) and memory, and the CPU executing a computer program stored in the memory. . The navigation device 4 may be configured using a general-purpose computer device, or may be configured as a dedicated hardware device. For example, the navigation device 4 may be configured using a server computer connected to a communication network such as the Internet. Also, each function of the navigation device 4 may be realized by cloud computing. Further, the navigation device 4 may be implemented by a single computer, or may be implemented by distributing the functions of the navigation device 4 to a plurality of computers. Also, the navigation device 4 may be configured to open a website using, for example, the WWW system.

The operation monitoring unit 401 performs operation monitoring for one or more mobile robots 2 . The operation monitoring unit 401 performs operation monitoring by associating position information, wireless communication quality information, and status information received from the mobile robot 2 in real time with information (mobile robot ID) for identifying the individual mobile robot 2 . The operation monitoring unit 401 periodically performs operation monitoring based on information (position information, wireless communication quality information, and state information) updated at intervals of, for example, one second. The operation monitoring unit 401 analyzes the position information, wireless communication quality information, and status information received from the mobile robot 2, and issues an alarm to a supervisor, for example, when a failure of the mobile robot 2 is detected. The operation information storage unit 402 stores the information (position information, wireless communication quality information, and status information) received from the mobile robot 2 by the operation monitoring unit 401 in order to investigate the cause of failure and consider future countermeasures.

The location/wireless quality storage unit 403 stores location/wireless quality information in which location information and wireless communication quality information are recorded in association with each other for each wireless communication method and wireless frequency band. The location wireless quality information may be provided for each date, day of the week, time zone, or event. For example, location wireless quality information for weekdays (Monday to Friday) and location wireless quality information for holidays (Saturdays, Sundays and public holidays) may be provided. For example, location wireless quality information for daytime hours and location wireless quality information for nighttime hours may be provided. For example, location wireless quality information for New Year's, Golden Week, or Obon may be provided.
FIG. 2 is a diagram showing a configuration example of the position/wireless quality storage unit 403 according to this embodiment. In the example of FIG. 2, the position/radio quality storage unit 403 stores position radio quality information 4031 of radio frequency band _LTE_a, position radio quality information 4032 of radio frequency band _LTE_b, etc. for the radio communication system "LTE". . Further, the location/wireless quality storage unit 403 stores location wireless quality information 4033 of wireless frequency band_5G_a, location wireless quality information 4034 of wireless frequency band_5G_b, and the like for the wireless communication system “5G”.

For example, Band 1 (2.1 GHz), Band 18 (800 MHz), etc. are used as radio frequency bands of LTE.

For example, the location radio quality information 4031 records each radio communication quality _LTE_a_a, radio communication quality _LTE_a_b, . . . at each position _a, position _b, . It is information that has been For example, the location wireless quality information 4033 is recorded in association with each wireless communication quality_5G_a_a, wireless communication quality_5G_a_b, . It is information that has been

In this embodiment, the location/wireless quality storage unit 403 stores at least location/wireless quality information for an area including the service area of the delivery service system. The service target area of this delivery service system is a target area (target area) to which the navigation device 4 provides route information. The position/wireless quality storage unit 403 according to the present embodiment stores the wireless communication system (LTE, 5G, etc.) and the wireless frequency band (wireless frequency (band_LTE_a, radio frequency band_LTE_b, radio frequency band_5G_a, radio frequency band_5G_b, etc.), position radio quality information recorded in association with the position included in the target area and the radio communication quality at the position is stored. .

The location information and the wireless communication quality information recorded in the location wireless quality information are information transmitted from the mobile robot 2 or the portable terminal 3 to the navigation device 4, for example. Note that position information and wireless communication quality information measured by a device other than the mobile robot 2 and the mobile terminal 3 may be recorded in the position wireless quality information.

Also, the position information is, for example, GPS coordinates. For indoor facilities where GPS coordinates cannot be obtained, absolute position information obtained by indoor positioning technology such as IMES (Indoor Messaging System) may be used as position information. Also, the wireless communication quality information is, for example, RSRP (Reference Signal Received Power) indicating the received power of LTE.

The map information storage unit 404 stores road map data of the whole country, and facility data such as various facilities and shops associated therewith. The road map data is given as link data in which, for example, a road on a map is divided into a plurality of parts using intersections and the like as nodes, and the parts between the nodes are defined as links. This link data includes data such as a link-specific identifier (link ID), link length, position information (longitude, latitude) of the start and end points (nodes) of the link, angle (direction) data, road width, and road type. consists of The road map data may include lane information indicating lanes through which the mobile robot 2 can pass. Moreover, the map information storage unit 404 may further store indoor map data.

Based on the location/wireless quality information stored for each wireless communication method and wireless frequency band in the location/wireless quality storage unit 403, the wireless quality movement cost conversion unit 405 converts each The wireless communication quality information recorded in association with the location information corresponding to the road is converted into a wireless quality link cost. The wireless quality link cost obtained by the wireless quality movement cost conversion unit 405 is stored in the map information storage unit 404 in association with the corresponding link data in the road map data of the map information storage unit 404 .

For example, the radio quality transfer cost conversion unit 405 divides the value of the radio quality link cost into three stages, and if the radio communication quality is sufficiently good, the radio quality link cost is "0", and if the radio communication quality is not cut off, the radio quality link cost is "0". If the radio communication quality is poor, the radio quality link cost is set to "high", and if there is a possibility that the radio communication will be disconnected, the radio quality link cost is set to "∞".
Note that if the wireless communication quality is above a certain level, the possibility of disconnection of the wireless communication is sufficiently low. From this, if a predetermined wireless communication quality is satisfied (for example, if the received power is equal to or higher than a predetermined value), the wireless quality link cost may be made small (eg, radio quality link cost '0'), otherwise the radio quality link cost may be made large (eg, radio quality link cost 'high' or '∞').

For example, the wireless quality movement cost conversion unit 405 selects a value near the lowest value of the wireless communication quality information considering the lowest value of the wireless communication quality information and an outlier from the wireless communication quality information group corresponding to each link data. It may be subject to conversion of the radio quality link cost. This is to calculate the possibility of disconnection of wireless communication as a risk when the mobile robot 2 travels on the road of the link data.

The route search unit 411, which will be described later, sequentially calculates (integrates) the costs of roads (links) from the departure point to the destination to the next reachable intersection (node). Select the route with the lowest cost to the ground. Therefore, setting a small radio quality link cost value for a road makes the road more likely to be selected as a route.

The mobile terminal position information storage unit 406 stores the history of the position information of each mobile terminal 3 . For example, the GPS coordinates of each mobile terminal 3 are stored in association with the time.

The outdoor population density estimation unit 407 determines whether each mobile terminal 3 was indoors or outdoors based on the history of location information stored in the mobile terminal location information storage unit 406. Based on this, the outdoor population density is estimated for each preset area. Outdoor population density is the number of people present outdoors per unit area. The outdoor population density calculated by the outdoor population density estimation unit 407 is stored in the map information storage unit 404 in association with the corresponding link data in the road map data of the map information storage unit 404 .

For example, the outdoor population density estimation unit 407 determines that a certain mobile terminal 3 was indoors when it is determined that the change in location information is less than a certain amount and there is almost no change, and the change in the location information is If it is determined that the value is equal to or greater than a certain value and has changed to some extent, it is determined that the person was outdoors.

In addition, the outdoor population density estimation unit 407 performs map matching by comparing the position information of each mobile terminal 3 with the road map data stored in the map information storage unit 404, and determines whether the mobile terminal 3 uses the road. It can be presumed that Map matching is a process of correcting position information obtained by GPS, which may contain errors, so that it is on the road using map information. Map matching is used, for example, in car navigation systems.

Moreover, the outdoor population density estimation unit 407 may determine whether the means of transportation of the mobile terminal 3 is walking or driving, based on the moving speed of the mobile terminal 3 .

The outdoor population density estimation unit 407 may estimate the outdoor population density for each month, day of the week, or time period. This is because even in the same area, the outdoor population density may vary greatly depending on the month, day of the week, time of day, and the like.

Moreover, the outdoor population density estimation unit 407 may estimate the outdoor population density by a method different from the method using the position information of the mobile terminal 3 . The outdoor population density estimation unit 407 may estimate the outdoor population density, for example, by using the video captured by the mobile robot 2 and based on the human image recognition result for the captured video.

The movement cost calculation unit 408 periodically uses the information stored in the map information storage unit 404 to calculate the total link cost for each link of each road for each wireless communication method and wireless frequency band. do. Movement cost calculator 408 calculates the total link cost using at least the radio quality link cost. The total link cost calculated by the movement cost calculation unit 408 is stored in the map information storage unit 404 in association with the corresponding link data in the road map data of the map information storage unit 404 .

Based on the wireless quality link cost, the movement cost calculation unit 408 weights each link of each road so that poor wireless communication quality results in a low evaluation. For example, based on the radio quality link cost, the movement cost calculation unit 408 weights road links for which radio communication is likely to be disconnected so that the total link cost becomes the largest. may Thereby, stable wireless communication between the mobile robot 2 and the remote monitoring device 20 is realized.

Also, the movement cost calculation unit 408 may calculate the total link cost based on the outdoor population density. The movement cost calculation unit 408 may weight links of roads having an outdoor population density equal to or higher than a threshold so that the total link cost increases. This allows the mobile robot 2 to travel on roads with few people.

Further, the movement cost calculation unit 408 may calculate the total link cost based on at least one of the type of the mobile robot 2 and the content of the delivery by the mobile robot 2, and the road condition of each link of each road. good. The types of mobile robots 2 are classified according to the size, structure, and the like of the mobile robots 2 . Also, the types of mobile robots 2 are classified according to the wireless communication method and wireless frequency band that can be used by the mobile robot 2 . The contents of the delivery by the mobile robot 2 include, for example, the type of package to be delivered by the mobile robot 2 and the expected loading amount.

For example, the movement cost calculation unit 408 does not increase the total link cost because a small mobile robot 2 can safely travel on a road link with a road width less than the threshold, but does not increase the total link cost for a large mobile robot. In the case of 2, the total link cost is increased. In addition, since it is assumed that it may be difficult for the mobile robot 2 to climb over bumps in the road depending on the structure of the mobile robot 2 , the movement cost calculation unit 408 does not allow the mobile robot 2 of the corresponding type to link roads with bumps. , increase the total link cost. Further, when the type of parcel delivered by the mobile robot 2 is fragile, the movement cost calculation unit 408 preferably reduces the total link cost of the road link with less unevenness because it is preferable to travel on roads with less unevenness. On the other hand, the total link cost of the link of the road with many unevenness is increased.

In addition, the travel cost calculator 408 may use evaluation factors used in known navigation systems as information used to calculate the total link cost. Evaluation factors used in known navigation systems are, for example, required link distance, required travel time, weighting based on road conditions and road width, weighting based on traffic signal frequency, weighting based on traffic congestion tendency, and the like.

The order information storage unit 409 receives order information for ordering products from the user terminal 1 and stores the received order information. The order information storage unit 409 performs purchase processing in cooperation with a purchase system (not shown) and formulates a product delivery plan. The destination acquisition unit 410 acquires destination information from order information stored in the order information storage unit 409 .

Based on the total link cost calculated by the movement cost calculator 408, the route searcher 411 searches for a route from the starting point to the destination of the mobile robot 2 as the route along which the mobile robot 2 is scheduled to travel. The destination of the mobile robot 2 is the location indicated by the destination information obtained by the destination obtaining unit 410 from the order information. The starting point of the mobile robot 2 is set in advance. For example, a product delivery base (for example, a physical distribution warehouse where products are stored, a store that handles delivery closest to the destination, etc.) is set in advance as the starting point of the mobile robot 2 . Further, when the mobile robot 2 is transported to the vicinity of the destination by a vehicle, the location of the transport destination of the mobile robot 2 is set in advance as the starting point of the mobile robot 2 .

As a route search method used by the route search unit 411, for example, the Dijkstra method, A* algorithm, genetic algorithm, or the like can be used.

The route distribution unit 412 transmits to the mobile robot 2 route information indicating the route searched by the route search unit 411 .

Next, a navigation method according to this embodiment will be described with reference to FIG. FIG. 3 is a flow chart showing an example of the procedure of the navigation method according to this embodiment.

(Step S1) The route search unit 411 acquires a departure point where the mobile robot 2 starts traveling and a destination where the mobile robot 2 travels.

(Step S2) The route search unit 411 acquires the type of the mobile robot 2 and the content of the delivery.

(Step S3) The route search unit 411 recognizes the wireless communication method and wireless frequency band that can be used by the mobile robot 2 from the type of the mobile robot 2 acquired in step S2. Correspondence relationships between types of mobile robots 2 and available wireless communication systems and wireless frequency bands are set in navigation device 4 in advance.

(Step S4) The route search unit 411 designates the search range including the starting point and the destination of the mobile robot 2 acquired in step S1 and the link cost calculation conditions to the movement cost calculation unit 408, and performs the search. Instruct to calculate the total link cost for each link for each road in range. Link cost calculation conditions include the type of the mobile robot 2 and the details of delivery. The link cost calculation conditions include at least information indicating the wireless communication system and wireless frequency band that the mobile robot 2 can use.

The movement cost calculation unit 408 calculates the total link cost for each wireless communication method and radio frequency band for each link of each road within the search range in response to the total link cost calculation instruction from the route search unit 411. . In calculating the total link cost, each link of each road is weighted so that poor wireless communication quality results in a low evaluation. The movement cost calculation unit 408 stores the calculated total link cost in the map information storage unit 404 in association with the corresponding link data in the road map data in the map information storage unit 404 . When there are a plurality of radio communication systems and radio frequency bands that can be used by the mobile robot 2, the movement cost calculation unit 408 calculates a radio communication cost that can obtain the best radio communication quality for each link of each road. The total link cost for the method and radio frequency band may be stored in the map information storage unit 404 in association with the corresponding link data.

The movement cost calculation unit 408 responds to the route search unit 411 with the completion of calculation of the total link cost.

(Step S5) The route search unit 411 calculates the total link cost calculated by the movement cost calculation unit 408 in step S4 from the departure point and the destination of the mobile robot 2 acquired in step S1. Search for a route to reach the ground. In this route search, a route that minimizes the total link cost of each link that passes from the starting point to the destination is searched.

(Step S6) The route distribution unit 412 transmits to the mobile robot 2 route information indicating the route of the search result of step S5.

FIG. 4 is an explanatory diagram for explaining an example of a route search method. FIG. 5 is an explanatory diagram for explaining the route search method according to this embodiment. In FIGS. 4 and 5, circles indicate nodes, and lines connecting nodes indicate links. In addition, S is the node of the departure point, and G is the node of the destination. Also, the number written on the link indicates the link cost. FIG. 4 shows link costs when wireless communication quality is not considered. On the other hand, FIG. 5 shows the total link cost according to the present embodiment when wireless communication quality is considered. Also, here, it is assumed that the link L2 has poor wireless communication quality and is highly likely to be disconnected.

In the case of the link costs in FIG. 4, as a result of the route search, the route with the smallest total link cost is "L1→L2→L3" as the route from the starting point "node S" to the destination "node G". is selected. Since the link cost in FIG. 4 does not consider the wireless communication quality, the link L2, which has a high possibility of disconnection of the wireless communication, is selected as the route. As a result, if the wireless communication between the mobile robot 2 and the remote monitoring device 20 is cut off on the selected route, the mobile robot 2 may become unable to be remotely monitored.

On the other hand, in FIG. 5, for the link L2, the total link cost "4+∞" is set by adding the wireless quality link cost "∞" to the link cost "4" in FIG. As a result, according to the total link cost in FIG. 5, the link L2, which has a high possibility of disconnection of wireless communication, is not selected as a route. In the case of the link costs in FIG. 5, as a result of the route search, the route from the starting point "node S" to the destination "node G" has the smallest total link cost, which is "L4→L5." is selected. According to this selected route “L4→L5”, stable wireless communication between the mobile robot 2 and the remote monitoring device 20 can be realized.

If it is impossible to reach the destination from the departure point without passing through a link that is likely to disconnect wireless communication, the link may be selected as the route from the departure point to the destination. . If a link with a high possibility of disconnection of wireless communication exists in the route of the search result, the route search unit 411 outputs wireless disconnection alert information indicating the link. A remote supervisor can recognize in advance a location where wireless communication between the mobile robot 2 and the remote monitoring device 20 is likely to be disconnected from the wireless disconnection alert information.

According to the embodiment described above, it is possible to provide route information for achieving stable wireless communication between the mobile robot 2 and the remote monitoring device 20 . As a result, it is possible to realize stable wireless communication when remotely monitoring the mobile robot 2 by wireless communication.

Although the embodiments of the present invention have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments, and design changes and the like are also included within the scope of the present invention.

Although the navigation system is applied to the delivery service system in the above-described embodiments, it may be applied to systems other than the delivery service system. For example, the navigation system according to the above-described embodiments may be applied to a road inspection service system that inspects roads using mobile robots.

Also, in the above-described embodiments, a mobile robot is used as an example of a mobile body, but the mobile robot is not limited to this. As the moving object, a vehicle that automatically operates (automatic driving vehicle), an autonomous flying object, or the like may be applied.

Alternatively, a computer program for realizing the functions of the devices described above may be recorded in a computer-readable recording medium, and the program recorded in the recording medium may be read and executed by the computer system. Note that the “computer system” referred to here may include hardware such as an OS and peripheral devices.
In addition, "computer-readable recording medium" includes writable nonvolatile memories such as flexible discs, magneto-optical discs, ROMs and flash memories, portable media such as DVDs (Digital Versatile Discs), and computer system built-in media. A storage device such as a hard disk that

Furthermore, "computer-readable recording medium" means a volatile memory (e.g., DRAM (Dynamic Random Access Memory)), which holds the program for a certain period of time, is also included.
Further, the above program may be transmitted from a computer system storing this program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in a transmission medium. Here, the "transmission medium" for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line.
Further, the program may be for realizing part of the functions described above. Further, it may be a so-called difference file (difference program) that can realize the above-described functions in combination with a program already recorded in the computer system.

DESCRIPTION OF SYMBOLS 1... User terminal 2... Mobile robot 3... Portable terminal 4... Navigation device 10... Navigation system 20... Remote monitoring apparatus 401... Operation monitoring part 402... Operation information storage part 403... Position/wireless Quality storage unit 404 Map information storage unit 405 Wireless quality movement cost conversion unit 406 Portable terminal location information storage unit 407 Outdoor population density estimation unit 408 Movement cost calculation unit 409 Order information storage unit , 410... Destination acquisition unit, 411... Route search unit, 412... Route distribution unit

Claims (6)

A navigation device that provides route information indicating a route from a departure point to a destination to a mobile object that communicates with a remote monitoring device that remotely monitors the mobile object via a wireless communication line,
For each wireless communication system and wireless frequency band in which wireless communication services are provided in the target area, which is the target area for which the route information is provided, the location included in the target area and the wireless communication quality at that location are associated. a location wireless quality storage unit for storing recorded location wireless quality information;
location wireless quality information corresponding to a wireless communication method and a radio frequency band available to the mobile unit among a plurality of pieces of location wireless quality information stored for each wireless communication method and radio frequency band in the location wireless quality storage unit; a cost calculation unit that weights the route candidate so that a poor wireless communication quality at a position on the route results in a low evaluation,
a route search unit that searches for the route based on the weighting from among the weighted route candidates;
navigation device. Further comprising an outdoor population density estimation unit for estimating an outdoor population density, which is the number of people existing outdoors per unit area, for each area in the target area;
The cost calculation unit weights the route candidate so that the larger the estimated value of the outdoor population density in the area containing the route candidate, the lower the evaluation.
Navigation device according to claim 1. The cost calculation unit weights the candidate route based on at least one of the type of the mobile object and the content of delivery by the mobile object, and the road conditions of the candidate route.
3. A navigation device according to claim 1 or 2. The route searching unit outputs wireless disconnection alert information indicating the location when there is a location where wireless communication is likely to be disconnected in the route of the search result,
A navigation device according to any one of claims 1 to 3. A navigation method for providing route information indicating a route from a departure point to a destination to a mobile object that communicates with a remote monitoring device that remotely monitors the mobile object via a wireless communication line,
For each wireless communication system and wireless frequency band in which wireless communication services are provided in the target area, which is the target area for which the route information is provided, the location included in the target area and the wireless communication quality at that location are associated. a location wireless quality storing step of storing the recorded location wireless quality information in a location wireless quality storage unit;
location wireless quality information corresponding to a wireless communication method and a radio frequency band available to the mobile unit among a plurality of pieces of location wireless quality information stored for each wireless communication method and radio frequency band in the location wireless quality storage unit; a cost calculation step of weighting the route candidate so that a poor wireless communication quality at a position on the route results in a low evaluation,
a route searching step of searching for the route based on the weighting from among the weighted route candidates;
Navigation methods including . A computer of a navigation device that provides route information indicating a route from a departure point to a destination to a mobile object that communicates with a remote monitoring device that remotely monitors the mobile object via a wireless communication line. ,
For each wireless communication system and wireless frequency band in which wireless communication services are provided in the target area, which is the target area for which the route information is provided, the location included in the target area and the wireless communication quality at that location are associated. a location wireless quality storing step of storing the recorded location wireless quality information in a location wireless quality storage unit;
location wireless quality information corresponding to a wireless communication method and a radio frequency band available to the mobile unit among a plurality of pieces of location wireless quality information stored for each wireless communication method and radio frequency band in the location wireless quality storage unit; a cost calculation step of weighting the route candidate so that a poor wireless communication quality at a position on the route results in a low evaluation,
a route searching step of searching for the route based on the weighting from among the weighted route candidates;
A computer program for executing

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