JP7436346B2 - Navigation device, navigation method and computer program - Google Patents

Description

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

In recent years, navigation technology that assumes autonomously moving robots and self-driving vehicles traveling outdoors has been studied. For example, Patent Document 1 describes a navigation data generation system that acquires navigation data based on a navigation route and the node type of an intermediate node (an operation to be performed by a vehicle at a node) when automatically transporting an object. ing.

Special table 2019-537730 publication

When remotely monitoring a robot or self-driving vehicle that autonomously moves outdoors via wireless communication, it is preferable that the robot or self-driving vehicle move along a route that does not interrupt wireless communication. However, with the conventional navigation technology described above, it is not possible to navigate a route in which wireless communication is not interrupted.

The present invention has been made in consideration of such circumstances, and its purpose is to realize stable wireless communication when remotely monitoring a mobile body using wireless communication.

(1) One aspect of the present invention is a navigation device that provides route information indicating a route from a departure point to a destination to a moving object whose remote monitoring is performed via a wireless communication line, a location wireless quality base station information storage unit that stores location wireless quality base station information in which wireless communication quality at the location and base station identification information for identifying a base station that provides wireless communication connection at the location are recorded in association with each other; Then, based on the location wireless quality base station information stored in the location wireless quality base station information storage unit, the route candidate is given a low evaluation if the wireless communication quality at a position on the route is poor. a cost calculation unit that weights the route; a route search unit that searches for the route based on the weighting from among the weighted route candidates; and a location stored in the location wireless quality base station information storage unit. a wireless quality old and new comparison unit that compares the wireless communication quality of the wireless quality base station information with the wireless communication quality at the timing when the mobile object moves toward the destination; and a comparison between the wireless quality new and old comparison unit. a wireless quality deterioration amount correction unit that corrects the wireless communication quality deterioration amount with respect to the wireless communication quality of the location wireless quality base station information stored in the location wireless quality base station information storage unit, based on the result; It is a navigation device equipped with.
(2) In one aspect of the present invention, the route search unit is configured to determine whether wireless communication is likely to be disconnected on the route of the previous search result as a result of the correction of the amount of wireless communication quality deterioration. This is the navigation device described in (1) above, which performs a re-search.
(3) In one aspect of the present invention, the wireless quality deterioration amount correction unit connects the mobile object for wireless communication at a position where it is determined that the wireless communication quality has deteriorated as a result of the comparison by the wireless quality old and new comparison unit. The navigation device according to any one of (1) and (2) above, which corrects the amount of wireless communication quality deterioration limited to a wireless communication connection range provided by a base station.
(4) One aspect of the present invention is that the wireless communication quality deterioration amount correction unit corrects the wireless communication quality deterioration amount when the wireless communication quality deterioration amount continues for a certain period of time and exceeds a certain value. The navigation device is any one of 1) to (3).
(5) In one aspect of the present invention, the wireless quality deterioration amount correction unit is configured to select at least one of a wireless frequency band, a wireless environment classification, and a distance from a wireless communication quality measurement point and a worst value point to a base station. The navigation device according to any one of (1) to (4) above, wherein the correction amount of the wireless communication quality deterioration amount is changed based on either of the above.
(6) In one aspect of the present invention, the location wireless quality base station information storage unit stores, as a result of the correction of the wireless communication quality deterioration amount, the wireless communication quality is worse than a threshold value at which it is determined that wireless communication disconnection occurs. The navigation device according to any one of (1) to (5) above, stores the base station identification information of another base station and the location wireless quality base station information whose wireless communication quality has been changed for the location where the navigation device has changed. .
(7) One aspect of the present invention is the navigation system according to any one of (1) to (6) above, wherein the mobile body is a mobile body that performs delivery, and the route is a route that the mobile body delivers. It is a device.

(8) One aspect of the present invention is a navigation method that provides route information indicating a route from a departure point to a destination to a moving object whose remote monitoring is performed via a wireless communication line, and in which the location and Storing location wireless quality base station information in which wireless communication quality at the location and base station identification information for identifying a base station that provides wireless communication connection at the location are recorded in association with each other in the location wireless quality base station information storage unit. a step of storing location wireless quality base station information, and determining wireless communication at a location on the route for the route candidate based on the location wireless quality base station information stored in the location wireless quality base station information storage unit; a cost calculation step of performing weighting so that poor quality results in a low evaluation; a route searching step of searching for the route based on the weighting from among the weighted route candidates; and the location wireless quality base station. a wireless quality old and new comparison step of comparing the wireless communication quality of the location wireless quality base station information stored in the information storage unit with the wireless communication quality at the timing when the mobile object moves toward the destination; , based on the comparison result of the wireless quality old and new comparison step, correct the wireless communication quality deterioration amount with respect to the wireless communication quality of the location wireless quality base station information stored in the location wireless quality base station information storage unit. This navigation method includes a step of correcting the amount of wireless quality deterioration.

(9) One aspect of the present invention is to provide a computer of a navigation device with route information indicating a route from a departure point to a destination for a mobile object whose remote monitoring is performed via a wireless communication line. , the location wireless quality base station information in which the wireless communication quality at the location and the base station identification information identifying the base station that provides the wireless communication connection at the location are recorded in association with each other is stored in the location wireless quality base station information storage unit. Based on the step of storing location wireless quality base station information and the location wireless quality base station information stored in the location wireless quality base station information storage unit, the route candidate a cost calculation step of performing weighting so that poor communication quality results in a low evaluation; a route searching step of searching for the route based on the weighting from among the weighted route candidates; and the location wireless quality base. a wireless quality old and new comparison step of comparing the wireless communication quality of the location wireless quality base station information stored in the station information storage unit with the wireless communication quality at the timing when the mobile object moves toward the destination; and, based on the comparison result of the old and new wireless quality comparison step, correct the amount of wireless communication quality deterioration for the wireless communication quality of the location wireless quality base station information stored in the location wireless quality base station information storage unit. This is a computer program for executing a radio quality deterioration amount correction step.

According to the present invention, it is possible to realize stable wireless communication when remotely monitoring a mobile object using wireless communication.

FIG. 1 is a block diagram illustrating a configuration example of a navigation system 10 according to an embodiment. It is a diagram showing an example of the configuration of a location/wireless quality/base station ID storage unit 403 according to an embodiment. 3 is a flowchart illustrating an example of a procedure of a route search method according to an embodiment. It is an explanatory diagram for explaining an example of the route search method concerning one embodiment. It is an explanatory diagram for explaining a route search method concerning one embodiment. It is an explanatory view for explaining an effect concerning one embodiment. 3 is a flowchart illustrating an example of a procedure of a navigation method according to an embodiment.

Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, a navigation system in a delivery service system that performs delivery using autonomously moving robots (hereinafter referred to as mobile robots) will be described as an example.

FIG. 1 is a block diagram illustrating a configuration example of a navigation system 10 according to an embodiment. In FIG. 1, a mobile robot 2 communicates with a navigation device 4 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 navigation device 4 according to this embodiment has a remote monitoring function in addition to the navigation function. Note that a device other than the navigation device 4 outside the mobile robot 2 may be provided with the remote monitoring function.

The navigation device 4 uses a remote monitoring function to remotely monitor the mobile robot 2 via wireless communication. For example, the navigation device 4 receives images captured by the mobile robot 2 and sounds captured by 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 status of the mobile robot 2 in real time. Therefore, in the delivery service system according to this embodiment, stable wireless communication in the mobile robot 2 is required. Therefore, in this embodiment, the navigation device 4 provides route information for realizing stable wireless communication in the mobile robot 2.

In addition, in the unlikely event that wireless communication in the mobile robot 2 becomes unstable and communication with the navigation device 4 is interrupted, the mobile robot 2 will autonomously return to a location where communication with the navigation device 4 is restored. It has become. However, such a situation is undesirable. Therefore, it would be better if the route of the mobile robot 2 could be changed to a route that provides stable wireless communication before the wireless communication in the mobile robot 2 becomes unstable and the communication with the navigation device 4 is interrupted. preferable. Therefore, in this embodiment, the navigation device 4 attempts to change such a route.

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 specifies the destination to which the 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 may be a stationary communication terminal device (for example, a stationary personal computer). good.

The user terminal 1 includes a product ordering section 101 and a destination information input section 102. The product ordering unit 101 selects a product and orders the selected product in response to 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 automatically replenishes the product when the remaining amount of the item falls below a preset threshold. You may place an order.

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

Further, the destination information input unit 102 may use a GPS (Global Positioning System) positioning function 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 scenery around the user terminal 1 taken by the camera of the user terminal 1 to the destination information as reference information for the destination.

[Mobile robot]
The mobile robot 2 is a robot that can run autonomously. The mobile robot 2, for example, travels around town and delivers packages to a destination designated by a delivery service user.

The mobile robot 2 includes a current position acquisition unit 201, a wireless quality acquisition unit 202, a base station identification information (base station ID) acquisition unit 203, a status acquisition unit 204, a wireless communication unit 205, and a route information storage unit 206. , an imaging section 207 , a motion determination section 208 , and a motion control section 209 .

The current position acquisition unit 201 acquires the current position (position information) using a positioning system such as GPS. The wireless quality acquisition unit 202 acquires wireless communication quality (wireless communication quality information) when the wireless communication unit 205 performs wireless communication with the navigation device 4 for each wireless communication method and radio frequency band supported by the wireless communication unit 205. ) to obtain.

The base station ID acquisition unit 203 acquires the base station ID of each base station with which the mobile robot 2 (wireless communication unit 205) can establish a wireless communication connection. The base station ID is identification information that individually identifies each base station. An example of the base station ID is what is called CID (Cell ID). By combining MCC (Mobile Country Code), MNC (Mobile Network Code), LAC (Location Area Code), and CID (Cell ID), each country and each A base station of a communication carrier can be uniquely identified.

The status acquisition unit 204 acquires status data (status information) such as remaining battery power, temperature, and movement speed from various sensors included in the mobile robot 2 .

The wireless communication unit 205 performs wireless communication with the navigation device 4. The wireless communication unit 205 supports wireless communication systems such as LTE (Long Term Evolution) and 5G (fifth generation mobile communication system), and performs wireless communication via a base station of the wireless communication system that it supports. Furthermore, the wireless communication unit 205 may be compatible with an unlicensed wireless communication method such as Wi-Fi (registered trademark), and may perform wireless communication using the unlicensed wireless communication method.

The wireless communication unit 205 transmits information obtained by the current position acquisition unit 201, the wireless quality acquisition unit 202, the base station ID acquisition unit 203, and the status acquisition unit 204 to the operation monitoring unit 401 of the navigation device 4. Additionally, the wireless communication unit 205 receives route information transmitted from the route distribution unit 412 of the navigation device 4 and stores it in the route information storage unit 206. The route information stored in the route information storage unit 206 is utilized for determining the motion of the mobile robot 2.

The imaging unit 207 images the moving direction of the mobile robot 2. The motion determining unit 208 determines the next motion of the mobile robot 2. The motion determining unit 208 uses the current position acquired by the current position acquisition unit 201, the captured image captured by the imaging unit 207, etc. when moving along the route indicated by the route information stored in the route information storage unit 206. Based on this, the mobile robot 2 determines its motion in accordance with the surrounding environment.

The motion control unit 209 causes the mobile robot 2 to execute the motion determined by the motion determination unit 208. The motion control unit 209 controls the type and speed of movement of the mobile robot 2, such as forward movement, backward movement, and right/left turns, as well as the type of movement other than movement, such as changing the imaging direction of the imaging unit 207.

[Mobile device]
The mobile terminal 3 is a mobile communication terminal device such as a smartphone 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. The mobile terminal 3 may be, for example, the mobile terminals of all subscribers who have subscribed to a particular wireless communication carrier and who have agreed with the wireless communication carrier to acquire location information.

The mobile terminal 3 periodically reports the current position (position information) and the wireless communication quality (wireless communication quality information) at the current position to the navigation device 4 for each wireless communication method and radio frequency band that it supports. .

[Navigation device]
The navigation device 4 performs navigation for one or more mobile robots 2 from a starting point to a destination. Furthermore, the navigation device 4 performs operational monitoring of one or more mobile robots 2.

The navigation device 4 includes an operation monitoring section 401, an operation information storage section 402, a location/wireless quality/base station ID storage section 403, a map information storage section 404, a wireless quality movement cost conversion section 405, and a mobile terminal position storage section 403. Information storage section 406, outdoor population density estimation section 407, movement cost calculation section 408, order information storage section 409, destination acquisition section 410, route search section 411, route distribution section 412, wireless quality old and new It includes a comparison section 413, a wireless quality deterioration amount correction section 414, and an alternative route search instruction section 415. In this embodiment, the wireless quality movement cost conversion unit 405 and the movement cost calculation unit 408 correspond to a cost calculation unit.

Each function of the navigation device 4 is realized by the navigation device 4 including computer hardware such as a CPU (Central Processing Unit) and a memory, and the CPU executing a computer program stored in the memory. . Note that 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. Moreover, each function of the navigation device 4 may be realized by cloud computing. Further, the navigation device 4 may be realized by a single computer, or the functions of the navigation device 4 may be realized by distributing the functions to a plurality of computers. Furthermore, the navigation device 4 may be configured to open a website using, for example, a WWW system.

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

The location/wireless quality/base station ID storage unit 403 stores location/wireless quality base station information in which location information, wireless communication quality information, and base station ID are recorded in association with each other for each wireless communication method and radio frequency band. .

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

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

Location wireless quality base station information may be provided for each date, day of the week, time zone, or event. For example, location radio quality base station information for weekdays (Monday to Friday) and location radio quality base station information for holidays (Saturday, Sunday, and public holidays) may be provided. For example, location radio quality base station information for daytime time slots and location radio quality base station information for night time slots may be provided, respectively. For example, location wireless quality base station information for New Year's Day, Golden Week, and Obon holidays may be provided.

FIG. 2 is a diagram showing an example of the configuration of the location/wireless quality/base station ID storage unit 403 according to this embodiment. In the example of FIG. 2, the location/wireless quality/base station ID storage unit 403 stores location/wireless quality base station information 4031 for the radio frequency band _LTE_a and location/wireless quality base station information for the radio frequency band _LTE_b for the wireless communication system "LTE". Information 4032 and the like are stored. In addition, the location/wireless quality/base station ID storage unit 403 stores location/wireless quality base station information 4033 for radio frequency band_5G_a, positional radio quality base station information 4034 for radio frequency band_5G_b, etc. regarding the wireless communication system "5G". It is stored.

Note that, for example, Band 1 (2.1 GHz), Band 18 (800 MHz), etc. are used as radio frequency bands of LTE. Furthermore, for example, a 28 GHz band is used as a 5G radio frequency band.

For example, the location wireless quality base station information 4031 is information in which the wireless communication quality and base station ID at each position_a, position_b, ... of the radio frequency band_LTE_a of the wireless communication system "LTE" are recorded in association with each other. . For example, the location wireless quality base station information 4033 is information in which the wireless communication quality and base station ID at each position _a, position _b, ... of the radio frequency band_5G_a of the wireless communication system "5G" are recorded in association with each other. .

Further, the location wireless quality base station information 4032 is information in which the wireless communication quality and base station ID at each position_a, position_b, ... of the radio frequency band_LTE_b of the wireless communication system "LTE" are recorded in association with each other. . In addition, in the location wireless quality base station information 4032, the same base station ID_LTE_b_ab is recorded in association with location_a and location_b. This is because in the radio frequency band _LTE_b of the wireless communication system "LTE", the base station with base station ID_LTE_b_ab was providing the wireless communication connection at the positions _a and _b at the time of measuring the wireless communication quality at the positions _a and _b. It is.

In the location wireless quality base station information, the base station ID is information that identifies a base station that provides wireless communication connection at the location associated with the base station ID. Furthermore, in the location wireless quality base station information, the base station ID identifies the base station that was providing wireless communication connection at the location associated with the base station ID at the time of measurement of the wireless communication quality at the location. It is information.

Note that in the location wireless quality base station information, the wireless communication quality and base station ID recorded in association with the position may be the base station ID of the base station that has obtained the best wireless communication quality at the position. Furthermore, in the location wireless quality base station information, the wireless communication quality and base station ID recorded in association with the location are the base station IDs and the wireless communication quality of all base stations from which wireless communication quality was obtained at the location. It may be.

In this embodiment, the location/wireless quality/base station ID storage unit 403 stores location/wireless quality base station information of an area including at least the service target area of this 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 location/wireless quality/base station ID storage unit 403 according to this embodiment stores the wireless communication system (LTE, 5G, etc.) and radio frequency in which wireless communication service is provided in the target area where the navigation device 4 provides route information. For each band (radio frequency band_LTE_a, radio frequency band_LTE_b, radio frequency band_5G_a, radio frequency band_5G_b, etc.), the location included in the target area and the wireless communication quality and base station ID at the location are recorded in association with each other. Stores location wireless quality base station information.

The map information storage unit 404 stores nationwide road map data and accompanying facility data such as various facilities and stores. Road map data is provided 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 each node 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 in which the mobile robot 2 can travel. Furthermore, the map information storage unit 404 may further store indoor map data.

The wireless quality mobile cost conversion unit 405 converts wireless communication systems and wireless For each frequency band, wireless communication quality information recorded in association with position information corresponding to each road is converted into a wireless quality link cost.

The wireless quality mobile cost conversion unit 405 executes a wireless quality link cost conversion process to convert wireless communication quality information into a wireless quality link cost at a predetermined timing. For example, the wireless quality movement cost conversion unit 405 periodically executes a wireless quality link cost conversion process. For example, when location wireless quality base station information is added or changed in the location/wireless quality/base station ID storage unit 403, the wireless quality movement cost conversion unit 405 converts the wireless quality link cost for the location wireless quality base station information into Execute the conversion process.

The wireless quality link cost determined 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 wireless quality movement cost conversion unit 405 divides the value of the wireless quality link cost into three levels, and when the wireless communication quality is sufficiently good, the wireless quality link cost is set to "0", and when the wireless communication quality is not so high that the wireless communication is disconnected. When the wireless communication quality is poor, the wireless quality link cost is set to "large", and when there is a possibility that the wireless communication may be disconnected, the wireless quality link cost is set to "∞".

Note that if the quality of wireless communication is good above a certain level, the possibility that wireless communication will be disconnected becomes sufficiently low. From this, if a predetermined wireless communication quality is satisfied that can be determined to have a sufficiently low possibility of wireless communication being disconnected (for example, if the received power is above a predetermined value), the wireless quality link cost may be made small (for example, the radio quality link cost is set to "0"), and if that is not the case, the radio quality link cost may be made large (for example, the radio quality link cost is set to "large" or "∞").

For example, the wireless quality movement cost conversion unit 405 converts a value near the lowest value of the wireless communication quality information in consideration of the lowest value of the wireless communication quality information and outliers from the wireless communication quality information group corresponding to each link data. The wireless quality link cost may be converted. This is to calculate the possibility that wireless communication will be disconnected when the mobile robot 2 travels on the road of the link data as a risk.

Note that the route search unit 411, which will be described later, sequentially calculates (integrates) the cost of the road (link) from the departure point to the destination to the next intersection (node) that can be reached. Select the route with the lowest cost to reach the destination. Therefore, if a small wireless quality link cost value is set for a road, that road will be more likely to be selected as a route.

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

The outdoor population density estimation unit 407 determines whether each mobile terminal 3 was indoors or outdoors based on the history of the position information stored in the mobile terminal position information storage unit 406, and based on this determination result. Based on this, the outdoor population density is estimated for each preset area. Outdoor population density is the number of people per unit area outdoors. The outdoor population density determined 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 estimating unit 407 determines that the mobile terminal 3 is indoors when the change in location information is less than a certain value and is determined to be almost no change. If the value is above a certain level and it is determined that there has been a certain degree of change, it is determined that the person was outdoors.

In addition, the outdoor population density estimation unit 407 performs map matching by comparing the location information of each mobile terminal 3 with the road map data stored in the map information storage unit 404, and performs map matching to determine whether the mobile terminal 3 uses the road. It can be assumed that he did. Map matching is a process that uses map information to correct position information obtained by GPS, which may include errors, so that the position information is on the road. Map matching is used, for example, in car navigation systems.

Furthermore, the outdoor population density estimating unit 407 may determine, based on the moving speed of the mobile terminal 3, whether the means of transportation of the mobile terminal 3 is walking or a vehicle.

Note that the outdoor population density estimating unit 407 may estimate the outdoor population density for each month, day of the week, and time of day. 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, etc.

Furthermore, the outdoor population density estimating unit 407 may estimate the outdoor population density using a method different from the method using the position information of the mobile terminal 3. The outdoor population density estimating unit 407 may estimate the outdoor population density, for example, using a video shot by the mobile robot 2 and based on a human image recognition result for the shot 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 on each road for each wireless communication method and radio frequency band. do. The movement cost calculation unit 408 calculates the total link cost using at least the wireless 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.

The movement cost calculation unit 408 weights each link of each road based on the wireless quality link cost so that poor wireless communication quality is evaluated low. For example, based on the wireless quality link cost, the movement cost calculation unit 408 weights road links for which it is determined that there is a high possibility that wireless communication will be disconnected so that the total link cost is the largest. It's okay. This aims to realize stable wireless communication in the mobile robot 2.

Furthermore, 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 on roads where the outdoor population density is greater than or equal to a threshold value so that the total link cost becomes larger. This allows the mobile robot 2 to travel on roads with fewer people.

Furthermore, the movement cost calculation unit 408 may calculate the total link cost based on at least one of the type of mobile robot 2 and the content of delivery by the mobile robot 2, and the road condition of each link on each road. good. The types of mobile robots 2 are classified according to the size, structure, etc. of the mobile robots 2. Further, the types of mobile robots 2 are classified according to the wireless communication method and radio frequency band that can be used by the mobile robots 2. The contents of the delivery by the mobile robot 2 include, for example, the type of cargo 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 link on a road with a road width less than a threshold, but a large mobile robot In case 2, the total link cost is increased. In addition, the movement cost calculation unit 408 assumes that depending on the structure of the mobile robot 2, it may be difficult to overcome a step on the road, so the mobile robot 2 of the corresponding type is provided with a link on the road where there is a step. , increase the total link cost. Furthermore, when the type of cargo to be delivered by the mobile robot 2 is fragile, it is preferable to travel on a road with few unevenness, so the movement cost calculation unit 408 reduces the total link cost of links on roads with few unevenness. On the other hand, the total link cost of links on roads with many unevenness is increased.

Furthermore, the movement cost calculation unit 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 include, for example, the required distance of a link, the time required for travel, weighting based on road conditions and road width, weighting based on signal frequency, weighting based on 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 purchasing processing in cooperation with a purchasing system (not shown) and formulates a product delivery plan. The order information storage unit 409 stores scheduled delivery information such as the departure point, destination, and time zone in which the mobile robot 2 will deliver the product according to the formulated product delivery plan. The destination acquisition unit 410 acquires destination information from the order information or scheduled delivery information stored in the order information storage unit 409.

The route search unit 411 searches for a route from the starting point of the mobile robot 2 to the destination as a route along which the mobile robot 2 is scheduled to travel, based on the total link cost calculated by the movement cost calculation unit 408. The destination of the mobile robot 2 is the location indicated by the destination information acquired by the destination acquisition unit 410. The starting point of the mobile robot 2 is set in advance. For example, a product delivery base (for example, a distribution warehouse where the product is stored, a delivery handling store closest to the destination, etc.) is set in advance as the departure point of the mobile robot 2. Further, when the mobile robot 2 is transported by a vehicle to the vicinity of the destination, the location of the transportation destination of the mobile robot 2 is set in advance as the departure point of the mobile robot 2.

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

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

Here, the route search method according to this embodiment will be explained with reference to FIG. FIG. 3 is a flowchart illustrating an example of the procedure of the route search method according to the present embodiment.

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

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

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

(Step S4) The route search unit 411 specifies the search range including the departure point and destination of the mobile robot 2 obtained in step S1 and the link cost calculation conditions to the movement cost calculation unit 408, and performs the search. Instructs to calculate the total link cost for each link of each road within the range. The link cost calculation conditions include the type of mobile robot 2 and the content of delivery. The link cost calculation conditions include at least information indicating a wireless communication method and a wireless frequency band that the mobile robot 2 can use.

The movement cost calculation unit 408 calculates the total link cost for each link of each road within the search range for each wireless communication system and radio frequency band in response to the total link cost calculation instruction from the route search unit 411. . In calculating this total link cost, each link on 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. Note that if there are multiple wireless communication systems and wireless frequency bands that can be used by the mobile robot 2, the movement cost calculation unit 408 calculates the wireless communication method that provides the best wireless communication quality for each link on each road. The total link cost for the system 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 that the calculation of the total link cost has been completed.

(Step S5) The route search unit 411 searches the starting point and the destination of the mobile robot 2 obtained in step S1 based on the total link cost calculated by the movement cost calculating unit 408 in step S4. Search for a route to reach the ground. In this route search, a search is performed for a route that minimizes the total link cost of each link passed from the starting point to the destination.

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

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 searching method according to this embodiment. In FIGS. 4 and 5, circles indicate nodes, and lines connecting nodes indicate links. Further, the starting point node is S, and the destination node is G. Further, 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 taken into consideration. Further, here, it is assumed that the link L2 has poor wireless communication quality and there is a high possibility that the wireless communication will be disconnected.

In the case of the link costs in FIG. 4, as a result of the route search, the route from the departure point "Node S" to the destination "Node G" is "L1 → L2 → L3", which is the route with the minimum total link cost. is selected. Since the link cost in FIG. 4 does not take wireless communication quality into consideration, link L2 with a high possibility of wireless communication being disconnected is selected as the route. As a result, if the wireless communication between the mobile robot 2 and the navigation device 4 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, a total link cost "4+∞" is set for the link L2 by adding the radio quality link cost "∞" to the link cost "4" in FIG. As a result, according to the total link cost shown in FIG. 5, link L2, which has a high possibility of wireless communication being disconnected, 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 departure point "Node S" to the destination "Node G" is "L4→L5", which is the route with the minimum total link cost. is selected. According to this selected route "L4→L5", it is possible to realize stable wireless communication in the mobile robot 2. Thereby, the mobile robot 2 can be stably monitored remotely through wireless communication.

The explanation returns to FIG. 1.
The wireless quality old and new comparison unit 413 compares the current wireless communication quality at the current position of the mobile robot 2 monitored by the operation monitoring unit 401 and the position wireless quality stored in the position/wireless quality/base station ID storage unit 403. Compare the wireless communication quality at a location corresponding to the current location in the base station information. The timing of this comparison is the timing when the mobile robot 2 moves toward the destination. The timing at which the mobile robot 2 moves toward the destination is the timing at which the mobile robot 2 starts delivery, the timing at which the mobile robot 2 is moving for delivery, or the like. In other words, the wireless quality old and new comparison unit 413 compares the past wireless communication quality recorded in the location wireless quality base station information in the area where the mobile robot 2 makes deliveries and the wireless quality at the timing when the mobile robot 2 actually makes deliveries. Compare communication quality. Thereby, it can be determined whether or not the wireless communication quality at the timing when the mobile robot 2 actually makes a delivery has deteriorated compared to the past wireless communication quality.

The wireless quality deterioration amount correction unit 414 adjusts the wireless communication quality of the location wireless quality base station information stored in the location/wireless quality/base station ID storage unit 403 based on the comparison result of the wireless quality old and new comparison unit 413. Then, the amount of deterioration in wireless communication quality is corrected. The wireless communication quality deterioration amount is the amount by which the wireless communication quality at the timing when the mobile robot 2 actually delivers is worse than the past wireless communication quality recorded in the location wireless quality base station information.

The wireless quality deterioration amount correction unit 414 executes the wireless communication quality deterioration amount correction process when it is determined that the wireless communication quality has deteriorated as a result of the comparison by the wireless quality old and new comparison unit 413. For example, as a result of the comparison by the wireless quality old and new comparison unit 413, if the wireless communication quality deterioration amount exceeds a certain value for a certain period of time at a certain position, the wireless communication quality deterioration amount correction unit 414 performs a wireless communication quality deterioration amount correction process. may be executed.

The target for performing the wireless communication quality deterioration amount correction process will be explained. As a result of the comparison by the wireless quality old and new comparison unit 413, a position where it is determined that the amount of wireless communication quality deterioration has deteriorated is referred to as a deterioration position. The deterioration position is, for example, a position where the amount of deterioration in wireless communication quality continues to exceed a certain value for a certain period of time as a result of comparison by the old and new wireless quality comparison unit 413.

On the route that the mobile robot 2 travels to the destination, the base stations to which the mobile robot 2 connects for wireless communication may be handed over between a plurality of base stations that are installed at different locations. At this time, since each base station is installed at a different location, deterioration in wireless communication quality is likely to be limited to an area where wireless communication is connected to the same base station.

Therefore, it is preferable to correct the amount of wireless communication quality deterioration by limiting it to the wireless communication connection range provided by the base station to which the mobile robot 2 connects for wireless communication at the deteriorated position. Therefore, the wireless quality deterioration amount correction unit 414 sets the base station ID associated with the deterioration position as the correction target base station ID in the positional wireless quality base station information. The wireless quality deterioration amount correction unit 414 sets the wireless communication quality associated with the correction target base station ID in the location wireless quality base station information as the correction target wireless communication quality.

The wireless communication quality deterioration amount correction process will be explained. Here, RSRP will be described as an example of wireless communication quality.
If the current RSRP reported from the mobile robot 2 is Rc (dBm) and the RSRP of the location wireless quality base station information is Rp (dBm) at the deterioration position, the wireless quality deterioration amount correction unit 414 corrects the correction target. Correction is performed to update the worst value Rw (dBm) of the RSRP of wireless communication quality to "Rw-(Rp-Rc)".

Note that the worst value Rw (dBm) is not simply corrected by using "-(Rp - Rc)" as the correction amount for the amount of wireless communication quality deterioration, but by adjusting the wireless frequency band and wireless environment classification. The amount of correction for the amount of deterioration of the wireless communication quality may be changed based on at least one of the measurement point of the wireless communication quality and the distance from the worst value point to the base station.

For example, the amount of correction for the amount of wireless communication quality deterioration may be different between a high frequency band with strong straightness such as the 28 GHz band used as the radio frequency band of 5G and the 800 MHz band used as the radio frequency band of LTE. It's okay.

For example, open land, suburbs, small and medium-sized cities, and large cities are set as the wireless environment classifications to which the base station installation locations belong, and depending on whether the base station ID to be corrected belongs to open land, suburbs, small and medium-sized cities, or large cities, The amount of correction for the amount of deterioration in wireless communication quality may be changed.

For example, in the location wireless quality base station information, the distance from the position (measurement point) associated with each correction target wireless communication quality to the base station with the correction target base station ID, and the distance from the worst value position (worst value point) to the base station The amount of correction for the amount of wireless communication quality deterioration may be changed depending on the relationship with the distance to the station (for example, the size ratio, etc.).

Furthermore, machine learning may be used as an example of a method for determining the amount of correction for the amount of deterioration in wireless communication quality. Specifically, when the wireless communication quality actually deteriorates at the measurement point, how the wireless communication quality at the worst value point changes is actually measured. Then, a machine learning model is generated by performing machine learning using the measured data, and a correction amount for the amount of wireless communication quality deterioration is determined using the machine learning model.

In addition, if the difference between the current wireless communication quality and the past wireless communication quality is larger than a certain level with respect to the correction target base station ID, the correction amount of the wireless communication quality deterioration amount is The amount may be set to be worse than a threshold value (cutting determination threshold value) at which it is determined that disconnection occurs. This means that in such cases, there may be major changes such as changes in the tilt angle of the base station that make it difficult to trust the past wireless communication quality performance or trends of the base station's communication area (coverage). This is because a change in the wireless environment may have occurred.

In addition, the wireless quality deterioration amount correction unit 414 adds the base station ID and the wireless The communication quality may be replaced with another base station ID and wireless communication quality. Thereby, the wireless quality deterioration amount correction unit 414 determines whether or not it is possible to avoid disconnection of wireless communication by connecting the mobile robot 2 to another base station for wireless communication at the position.

Note that the wireless quality deterioration amount correction unit 414 corrects the wireless communication quality deterioration amount by adding the base station ID and the wireless The communication quality may be replaced with another base station ID and radio communication quality that is better than the disconnection determination threshold and its base station ID.

The above is a description of the wireless communication quality deterioration amount correction process.

After executing the wireless communication quality deterioration amount correction process on the wireless communication quality to be corrected in the location wireless quality base station information, the wireless quality deterioration amount correction unit 414 corrects the wireless communication quality to be corrected after the wireless communication quality deterioration amount has been corrected. is determined based on the cutting determination threshold. In this determination, if the wireless communication quality to be corrected after correcting the amount of wireless communication quality deterioration is worse than the disconnection determination threshold, it is determined that the wireless communication will be disconnected at the position associated with the wireless communication quality to be corrected. . On the other hand, if the corrected wireless communication quality after correcting the amount of wireless communication quality deterioration is better than the disconnection determination threshold, it is determined that wireless communication will not be disconnected at the position associated with the corrected wireless communication quality. .

When it is determined that a disconnection of wireless communication will occur as a result of the correction of the amount of wireless communication quality deterioration by the wireless quality deterioration amount correction portion 414, the alternative route search instruction unit 415 controls the location of each position associated with the correction target base station ID. The wireless quality link cost is updated by the wireless quality movement cost conversion unit 405 to the wireless quality link cost converted from the correction target wireless communication quality after correcting the amount of wireless communication quality deterioration. Next, the alternative route search instructing unit 415 instructs the route searching unit 411 to re-search a route using the updated wireless quality link cost.

The route search unit 411 searches for a route to the destination of the mobile robot 2 again in response to a route re-search instruction from the alternative route search instruction unit 415. When re-searching for this route, if the mobile robot 2 has not yet departed for delivery, a route from the departure point to the destination for delivery is searched. On the other hand, when the route is re-searched, if the mobile robot 2 is already moving for delivery, the route from the current position of the mobile robot 2 to the destination is searched. The route search method for re-searching the route is the same as the method described above.

The route distribution unit 412 transmits route information indicating the route as a result of the re-search by the route search unit 411 to the mobile robot 2, and moves the mobile robot 2 so as to update the route information held by the mobile robot 2 to the route information as a result of the re-search. Instruct robot 2. The mobile robot 2 receives the route information of the re-search result transmitted from the route distribution unit 412 of the navigation device 4, and updates the route information in the route information storage unit 206 to the route information of the re-search result.

In this embodiment, the navigation device 4 predicts in advance whether or not wireless communication will be disconnected on the route that the mobile robot 2 will travel in the future, and if it is predicted that the wireless communication will be disconnected, it will take a different route. Explore. This can prevent the mobile robot 2 from retracing its route after disconnection of wireless communication occurs.

FIG. 6 is an explanatory diagram for explaining the effects of this embodiment. In FIG. 6, C1 and C1a are the communication areas of base station B1. The communication area C1 is the communication area recorded in the location wireless quality base station information at the time of the first route search of the mobile robot 2. On the other hand, the communication area C1a is a communication area at the timing when the mobile robot 2 actually moves toward the destination G. C2 is the communication area of base station B2. The communication area C2 is the same at the time of the first route search of the mobile robot 2 and at the timing when the mobile robot 2 actually moves toward the destination G.

As a result of the first route search of the mobile robot 2, a route consisting of route R1 (indicated by a solid line in the figure) and route R2 (indicated by a broken line in the figure) is a route from the starting point S to the destination G. It is determined. The route R1 is a portion where the mobile robot 2 connects to the base station B1 by wireless communication. The route R2 is a portion where the mobile robot 2 connects to the base station B2 for wireless communication.

At the time of the first route search of the mobile robot 2, the route R1 and the route R2 exist in the communication areas C1 and C2 of the base stations B1 and B2 in the location wireless quality base station information, so the mobile robot 2 searches the route from the starting point S. It was predicted that wireless communication would not be disconnected even if the vehicle traveled to destination G via route R1 and route R2. However, at the timing when the mobile robot 2 actually moves toward the destination G, the communication area of the base station B1 is reduced from the communication area C1 to the communication area C1a. It is outside the range of area C1a. Therefore, when the mobile robot 2 moves along the route R1, a situation may occur in which wireless communication is disconnected at a portion R1b of the route R1 and the mobile robot 2 returns back along the route R1.

According to the present embodiment, at the timing when the mobile robot 2 moves toward the destination G, the route R1 is It is predicted that wireless communication will be disconnected. Then, the route for the mobile robot 2 to the destination G is searched again based on the current wireless communication quality. As a result of this re-search, another route to the destination G is searched, thereby preventing a situation in which the mobile robot 2 turns back along the route R1 after the wireless communication is cut off at the portion R1b of the route R1. Can be done.

Note that factors that cause the current wireless communication quality to be worse than the past wireless communication quality include the installation of radio wave propagation obstacles such as buildings and an increase in the load on base stations.

The navigation method according to this embodiment will be explained with reference to FIG. FIG. 7 is a flowchart illustrating an example of the procedure of the navigation method according to the present embodiment.

(Step S101) The wireless quality old and new comparison unit 413 compares the current wireless communication quality at the current position of the mobile robot 2 monitored by the operation monitoring unit 401 with the current wireless communication quality stored in the position/wireless quality/base station ID storage unit 403. Compare the radio communication quality of the location corresponding to the current location of the location radio quality base station information.

(Step S102) As a result of the comparison in step S101, it is determined whether the wireless communication quality has deteriorated. For example, if the amount of wireless communication quality deterioration exceeds a certain value for a certain period of time at a certain location, it is determined that the wireless communication quality has deteriorated, and if this is not the case, the deterioration is severe enough to cause the wireless communication to be disconnected. Since this is not the case, it is determined that the wireless communication quality has not deteriorated. Note that in the case of RSRP as an example of wireless communication quality, the fixed period is, for example, 30 seconds, and the fixed value is, for example, -20 dB.

As a result of the determination in step S102, if the wireless communication quality has deteriorated, the process advances to step S103. On the other hand, if the wireless communication quality has not deteriorated, the process in FIG. 7 ends.

(Step S103) The wireless quality deterioration amount correction unit 414 sets the base station ID associated with the deterioration position in the location wireless quality base station information as the correction target base station ID. Each position associated with the correction target base station ID in the location wireless quality base station information becomes information indicating the wireless communication connection range related to the correction target base station ID.

(Step S104) The wireless quality deterioration amount correction unit 414 adjusts the wireless communication quality for the wireless communication quality to be corrected in the wireless communication connection range related to the correction target base station ID extracted in step S103 in the location wireless quality base station information. Execute quality deterioration amount correction processing.

(Step S105) As a result of executing the wireless communication quality deterioration amount correction process in step S104, the wireless quality deterioration amount correction unit 414 determines that the worst value of the correction target wireless communication quality in the wireless communication connection range related to the correction target base station ID is disconnected. It is determined whether or not it is worse than a determination threshold. As a result of this determination, if it is worse than the cutting determination threshold, the process advances to step S106. On the other hand, if it is not worse than the cutting determination threshold, the process of FIG. 7 is ended.

(Step S106) The wireless quality deterioration amount correction unit 414 adjusts the base station information of the location wireless quality base station for the position where the wireless communication quality to be corrected in the wireless communication connection range related to the base station ID to be corrected is worse than the disconnection determination threshold. Replace the station ID and wireless communication quality with another base station ID and wireless communication quality. Next, the wireless quality deterioration amount correction unit 414 determines whether disconnection of wireless communication can be avoided by connecting the mobile robot 2 to the other base station for wireless communication at the position. As a result of this determination, if disconnection of wireless communication can be avoided, the process of FIG. 7 is ended. On the other hand, if the mobile robot 2 is unable to establish a wireless communication connection with the other base station, or even if the mobile robot 2 establishes a wireless communication connection with the other base station, the wireless communication quality is worse than the disconnection determination threshold and the wireless If disconnection of communication cannot be avoided, the process advances to step S107.

(Step S107) The alternative route search instruction unit 415 determines the correction target radio after the wireless communication quality deterioration amount has been corrected by the wireless quality movement cost conversion unit 405, regarding the wireless quality link cost of each position associated with the correction target base station ID. Update the communication quality to the converted wireless quality link cost. Next, the alternative route search instructing unit 415 instructs the route searching unit 411 to re-search a route using the updated wireless quality link cost. The route search unit 411 searches for a route to the destination of the mobile robot 2 again in response to a route re-search instruction from the alternative route search instruction unit 415.

(Step S108) The route distribution unit 412 transmits route information indicating the route as a result of the re-search by the route search unit 411 to the mobile robot 2, and uses the route information held by the mobile robot 2 as the route of the re-search result. Update information.

The process of FIG. 7 described above may be executed every time the wireless communication quality of the location wireless quality base station information is updated. This is to detect the possibility of wireless communication disconnection in the mobile robot 2 at an early stage.

Furthermore, even in the results of re-searching the route, if it is not possible to reach the destination from the departure point without passing through a link where wireless communication is likely to be disconnected, the link will be changed from the departure point to the destination. It may be selected as the route to reach. If there is a link in the search result route with a high possibility that wireless communication will be disconnected, the route search unit 411 outputs wireless disconnection alert information indicating the link. Based on the wireless disconnection alert information, a remotely monitoring person can recognize in advance a location where wireless communication between the mobile robot 2 and the navigation device 4 is likely to be disconnected.

According to the embodiment described above, it is possible to provide route information for realizing stable wireless communication in the mobile robot 2. Moreover, before the wireless communication in the mobile robot 2 becomes unstable and the communication with the navigation device 4 is interrupted, the route of the mobile robot 2 can be changed to a route that provides stable wireless communication. This provides the effect that stable wireless communication can be achieved when remotely monitoring the mobile robot 2 through wireless communication. Furthermore, it is possible to prevent the mobile robot 2 from retracing its route after disconnection of wireless communication occurs.

Although the embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like may be made without departing from the gist of the present invention.

In the embodiment described above, the navigation system is applied to the delivery service system, but it may be applied to other systems other than the delivery service system. For example, the navigation system according to the embodiment described above may be applied to a road inspection service system that inspects roads using a mobile robot.

Further, in the above-described embodiment, a mobile robot is used as an example of a moving body, but the present invention is not limited to this. As the moving object, a vehicle that performs self-driving (self-driving vehicle), a flying object that flies autonomously, or the like may be applied.

Further, a computer program for realizing the functions of each device described above may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read into a computer system and executed. Note that the "computer system" here may include hardware such as an OS and peripheral devices.
Furthermore, "computer-readable recording media" refers to flexible disks, magneto-optical disks, ROMs, writable non-volatile memories such as flash memory, portable media such as DVDs (Digital Versatile Discs), and media built into computer systems. A storage device such as a hard disk.

Furthermore, "computer-readable recording medium" refers to volatile memory (for example, DRAM (Dynamic It also includes those that retain programs for a certain period of time, such as Random Access Memory).
Further, the program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the "transmission medium" that transmits the program refers to a medium that has 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.
Moreover, the above-mentioned program may be for realizing a part of the above-mentioned functions. Furthermore, 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.

1... User terminal, 2... Mobile robot, 3... Mobile terminal, 4... Navigation device, 10... Navigation system, 401... Operation monitoring section, 402... Operation information storage section, 403... Location/wireless quality/base station ID storage Section, 404...Map information storage section, 405...Wireless quality movement cost conversion section, 406...Mobile terminal location information storage section, 407...Outdoor population density estimation section, 408...Movement cost calculation section, 409...Order information storage section, 410 ...Destination acquisition section, 411...Route search section, 412...Route distribution section, 413...Wireless quality old and new comparison section, 414...Wireless quality deterioration amount correction section, 415...Alternative route search instruction section

Claims (9)

A navigation device that provides route information indicating a route from a departure point to a destination for a moving object whose remote monitoring is performed via a wireless communication line,
A location wireless quality base station that stores location wireless quality base station information in which a location, wireless communication quality at the location, and base station identification information that identifies a base station that provides wireless communication connection at the location are recorded in association with each other. an information storage section;
Based on the location wireless quality base station information stored in the location wireless quality base station information storage unit, the route candidates are weighted so that if the wireless communication quality at a position on the route is poor, the evaluation is low. A cost calculation unit that performs
a route search unit that searches for the route from among the weighted route candidates based on the weighting;
Comparing the wireless communication quality of the location wireless quality base station information stored in the location wireless quality base station information storage unit with the wireless communication quality at the timing when the mobile object moves toward the destination. Wireless quality new and old comparison section,
Based on the comparison result of the old and new wireless quality comparison unit, correct the amount of wireless communication quality deterioration with respect to the wireless communication quality of the location wireless quality base station information stored in the location wireless quality base station information storage unit. a wireless quality deterioration amount correction unit;
A navigation device comprising: The route search unit re-searches the route when there is a possibility that wireless communication will be disconnected on the route of the previous search result as a result of the correction of the wireless communication quality deterioration amount.
The navigation device according to claim 1. The wireless quality deterioration amount correction unit adjusts the wireless communication connection range provided by the base station to which the mobile object connects for wireless communication at a position where it is determined that the wireless communication quality has deteriorated as a result of the comparison by the wireless quality old and new comparison unit. correcting the wireless communication quality deterioration amount in a limited manner;
The navigation device according to claim 1 or 2. The wireless communication quality deterioration amount correction unit corrects the wireless communication quality deterioration amount when the wireless communication quality deterioration amount exceeds a certain value for a certain period of time.
A navigation device according to any one of claims 1 to 3. The wireless quality deterioration amount correction unit adjusts the wireless communication quality based on at least one of a wireless frequency band, a wireless environment classification, and a distance from a wireless communication quality measurement point and a worst value point to a base station. Change the amount of correction for the amount of deterioration,
A navigation device according to any one of claims 1 to 4. The location wireless quality base station information storage unit is configured to store another base station for a position where the wireless communication quality has become worse than a threshold value for determining that wireless communication disconnection occurs as a result of the correction of the wireless communication quality deterioration amount. storing the base station identification information of the station and the location wireless quality base station information changed to the wireless communication quality;
A navigation device according to any one of claims 1 to 5. The mobile body is a mobile body that performs delivery,
The route is a route delivered by the mobile object,
A navigation device according to any one of claims 1 to 6. A navigation method that provides route information indicating a route from a departure point to a destination to a moving object whose remote monitoring is performed via a wireless communication line,
Stores location wireless quality base station information in which the location, wireless communication quality at the location, and base station identification information that identifies the base station that provides wireless communication connection at the location are recorded in association with each other. a step of storing location wireless quality base station information in the section;
Based on the location wireless quality base station information stored in the location wireless quality base station information storage unit, the route candidates are weighted so that if the wireless communication quality at a position on the route is poor, the evaluation is low. A cost calculation step for performing
a route searching step of searching for the route from among the weighted route candidates based on the weighting;
Comparing the wireless communication quality of the location wireless quality base station information stored in the location wireless quality base station information storage unit with the wireless communication quality at the timing when the mobile object moves toward the destination. Steps to compare old and new wireless quality,
Based on the comparison result of the wireless quality old and new comparison step, correcting the wireless communication quality deterioration amount with respect to the wireless communication quality of the location wireless quality base station information stored in the location wireless quality base station information storage unit. a wireless quality deterioration amount correction step;
Navigation methods including. a computer of a navigation device that provides route information indicating a route from a departure point to a destination for a mobile object whose remote monitoring is performed via a wireless communication line;
Stores location wireless quality base station information in which the location, wireless communication quality at the location, and base station identification information that identifies the base station that provides wireless communication connection at the location are recorded in association with each other. a step of storing location wireless quality base station information in the section;
Based on the location wireless quality base station information stored in the location wireless quality base station information storage unit, the route candidates are weighted so that if the wireless communication quality at a position on the route is poor, the evaluation is low. A cost calculation step for performing
a route searching step of searching for the route from among the weighted route candidates based on the weighting;
Comparing the wireless communication quality of the location wireless quality base station information stored in the location wireless quality base station information storage unit with the wireless communication quality at the timing when the mobile object moves toward the destination. Steps to compare old and new wireless quality,
Based on the comparison result of the wireless quality old and new comparison step, correcting the wireless communication quality deterioration amount with respect to the wireless communication quality of the location wireless quality base station information stored in the location wireless quality base station information storage unit. a wireless quality deterioration amount correction step;
A computer program for running.

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