JP4880048B2 - Navigation device, route search method, and computer program - Google Patents

Description

  The present invention relates to navigation technology for vehicles and the like.

  There are some accident zones (points) where traffic accidents occur frequently. In a technique related to a conventional car navigation system, when a route including an accident-prone area is presented, the route is displayed so that the user can recognize that the accident-prone area is included (for example, Patent Document 1). Furthermore, there is a car navigation device that informs the driver by screen display and voice guidance when approaching an accident-prone area during driving.

JP 2005-283395 A

  By the way, in many cases, a conventional car navigation device presents a route search request and presents it as “the earliest route” or “the shortest route”. However, the route that the user actually desires varies depending on the user, and even for the same user, the route varies from time to time. For example, some users want to avoid accident-prone areas to emphasize safety, while others want to choose the shortest route with some risk.

  None of the conventional car navigation devices sufficiently satisfy the various needs of such users.

  Accordingly, an object of the present invention is to provide a navigation technique for presenting a safe route to a user.

  Another object of the present invention is to provide a navigation technique for presenting a route to the user according to the safety level selected by the user.

  A navigation device according to one embodiment of the present invention includes a map storage unit storing map data including node data related to a node indicating an intersection and link data related to a road link connecting the nodes, and a road related to an accident occurrence point. One or more routes from the departure point to the destination point are received based on the map data by accepting a route search request specifying the departure point and the destination point, the accident link storage unit storing the accident occurrence link that is a link A route search unit for searching for a route having the shortest travel time, and the route search unit calculates an accident time at the accident occurrence link when calculating the travel time of the route including the accident occurrence link. The risk time converted from the risk of encountering to the link travel time is added to the link travel time of the accident occurrence link, Articles late occurrence links and calculates the travel time of the route to be included.

  In a preferred embodiment, in the route search request, when a safety priority designation indicating a degree of desirability of a highly secure route is received, the route search unit increases the risk as the received safety priority is higher. The travel time of the route including the accident occurrence link may be calculated by setting a longer time.

  In a preferred embodiment, the accident link storage unit further stores an accident frequency for each accident occurrence link, and the route search unit sets the risk time longer as the accident occurrence frequency is higher, and the accident The travel time of the route including the generated link may be calculated.

  In a preferred embodiment, when the accident data describing the accident occurrence point and the accident situation in text is received, the accident data is analyzed by text analysis, the accident occurrence link is identified, and stored in the accident link storage unit You may further provide the generation | occurrence | production link specific | specification means.

  In a preferred embodiment, the accident occurrence link identifying means identifies the node corresponding to the accident occurrence point, analyzes the text describing the accident situation, and determines the road link when the accident vehicle enters the node. The specified road link may be specified as the generated link.

  In a preferred embodiment, the accident occurrence link identifying means analyzes the text describing the accident situation, derives a vector indicating the approach direction of the accident vehicle, and determines the approach link from the road link vector connected to the node. You may specify.

It is a figure showing the whole route search system composition concerning one embodiment of the present invention. An example of the data structure of the accident occurrence link memory | storage part 15 is shown. An example of accident data 30 is shown. It is a figure explaining the situation of an accident. It is a flowchart which shows the process sequence of the route search process which the route search server 1 performs. It is a figure which shows typically the road map from the departure point to the destination point. FIG. 7 is a lookup table related to road links existing in the map of FIG. 6. FIG.

  Hereinafter, a route search system including a navigation device according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram showing an overall configuration of a route search system according to the present embodiment. In this system, as shown in the figure, a route search server 1, which is a navigation device, a user terminal device 3, and a road traffic information providing server 5 are connected to each other via a network 9. An input device 6 and a display device 7 are connected to the route search server 1.

  Each of the route search server 1 and the road traffic information providing server 5 is configured by, for example, a general-purpose computer system, and individual components or functions in the route search server 1 and the road traffic information providing server 5 described below are: For example, it is realized by executing a computer program. This computer program can be stored in a computer-readable recording medium.

  The user terminal device 3 may be a terminal device having a communication function, and may be, for example, a mobile phone, a portable information terminal, or a general-purpose personal computer. The user terminal devices 3 and 3 include a display device such as a liquid crystal panel and an input device such as a push button or a pointing device. When the user terminal device 3 is a mobile phone or the like, wireless communication is performed with the wireless base station 8.

  The route search server 1 includes a map data storage unit 11, an accident occurrence link identification processing unit 13, an accident occurrence link storage unit 15, a standard link travel time storage unit 17, and a route search unit 19.

  The map data storage unit 11 stores map data including node data related to nodes indicating intersections and the like, and link data related to road links connecting the nodes.

  The standard link travel time storage unit 17 stores a standard link travel time predetermined for each road link.

  The accident occurrence link storage unit 15 stores an accident occurrence link that is a road link related to the accident occurrence point. An example of the data structure of the accident occurrence link storage unit 15 is shown in FIG. That is, the accident occurrence link storage unit 15 includes, as data items, an accident occurrence link No 151 and the number of monthly accidents 153 indicating the accident frequency. The accident occurrence link No 151 may be, for example, a road link at a point where an accident has occurred, or a road link connected to an intersection where an accident has occurred. The number of monthly accidents 153 indicates the number of accidents per month, but instead of the number of monthly accidents, other numerical values indicating accident frequency may be used. Registration of the accident occurrence link No 151 and the number of monthly accidents 153 in the accident occurrence link storage unit 15 may be performed by the operator from the input device 6, for example, or by the accident occurrence link identification processing unit 13 described below. Good.

  Upon receiving the accident data describing the accident occurrence point and the accident situation in text, the accident occurrence link identification processing unit 13 performs text analysis of the accident data. The accident occurrence link identification processing unit 13 identifies the accident occurrence link according to the result of the text analysis and stores it in the accident occurrence link storage unit 15.

  For example, when the accident occurrence link storage unit 15 has the data structure of FIG. 2, the accident occurrence link identification processing unit 13 identifies the accident occurrence link No 151 from the accident data and counts the number of monthly accidents 153 for each accident occurrence link. To do.

  FIG. 3 shows an example of the accident data 30. As shown in the figure, the accident data 30 includes an accident occurrence point 31 and an accident situation 33 as data items. The accident occurrence point 31 includes text indicating the address of the accident occurrence point. The accident situation 33 includes text describing the accident situation. The accident data 30 includes data relating to accidents that occurred during one month.

  The accident occurrence link identification processing unit 13 identifies the node corresponding to the accident occurrence point, analyzes the text describing the accident situation, identifies the road link when the accident vehicle has entered the node, and is identified. The road link is the accident occurrence link.

  For example, the accident occurrence link identification processing unit 13 first performs text analysis (for example, morphological analysis) of the accident occurrence point 31 to specify the address of the accident occurrence point, and based on this address, the latitude and Specify longitude. The accident occurrence link identification processing unit 13 refers to the map data storage unit 11 and identifies road links or nodes (intersections) existing at the latitude and longitude points of the accident occurrence point. When an accident occurrence point specified by latitude and longitude corresponds to one road link, the road link becomes an accident occurrence link. On the other hand, when the accident occurrence point specified by the latitude and longitude corresponds to the node, the accident occurrence link identification processing unit 13 identifies one of the road links connected to the node as the accident occurrence link. To do.

  Next, the method for identifying the accident occurrence link when the accident occurrence point corresponds to the node will be described in more detail.

  The accident occurrence link identification processing unit 13 analyzes the text describing the accident situation (accident situation 33), derives a vector indicating the approach direction of the accident vehicle, and uses the road link vector connected to the node of the accident occurrence point. Identify the incoming link.

  For example, the accident occurrence link identification processing unit 13 performs text analysis of the accident situation 33 and extracts words. And the accident occurrence link specific process part 13 extracts the word for specifying the road where the vehicle which caused the accident approached the intersection of an accident point from the cut out word. For example, the accident occurrence link identification processing unit 13 extracts a word including a place name, for example. Then, an approach direction vector indicating the direction in which the vehicle has entered is derived from the position of the intersection (node) and the extracted word such as a place name. Furthermore, the accident occurrence link identification processing unit 13 acquires, for example, a vector indicating the direction of the road link connected to the intersection node from the map data storage unit 11, and calculates the inner product of these and the approach direction vector. Then, the road link having the largest inner product may be estimated as the road link entering the intersection (node). The accident occurrence link identification processing unit 13 sets the road link estimated here as the accident occurrence link. When there are a plurality of accident vehicles, the accident occurrence link identification processing unit 13 performs the above processing for each accident vehicle. As a result, the accident occurrence link identification processing unit 13 sets only the road link when the accident vehicle enters the node as the accident occurrence link even if many road links are connected to the node at the accident point. Also good.

  For example, it is assumed that two vehicles M1 and M2 have a collision accident at an intersection C as shown in FIG. 4 as shown in FIG. At this time, L4 and L8 are specified as the approach links when the two vehicles M1 and M2 enter the node N by the text analysis process of the accident data 30 described above. As a result, the accident occurrence links are also L4 and L8. That is, even if connected to the node N, the other road links (L1 to L3, L5 to L7) are not treated as accident occurrence links. Because these other links are not directly related to the accident.

  Returning to FIG. 1 again, the route search unit 19 accepts a route search request specifying a departure point and a destination point, and travels among one or more routes from the departure point to the destination point based on the map data. Find the route with the shortest time. The route search unit 19 outputs the route with the shortest travel time as a response to the route search request. For example, when the traffic information includes traffic jam information or the like, the route search unit 19 calculates the travel time of the entire route by adding the link travel time according to the traffic jam information.

  When calculating the travel time of the route including the accident occurrence link, the route search unit 19 converts the risk time of encountering an accident at the accident occurrence link into the link travel time, and the link travel time of the accident occurrence link. And the travel time of the route including the accident occurrence link is calculated.

  For example, the route search unit 19 refers to the accident occurrence link storage unit 15 to determine whether or not an accident occurrence link exists in the route from the departure point to the destination point. When an accident occurrence link exists in the route, the route search unit 19 acquires the number of monthly accidents 153 of the accident occurrence link from the accident occurrence link storage unit 15. Then, the route search unit 19 weights the standard link travel time in the standard link travel time storage unit 17 according to the number of monthly accidents 153. For example, the number of monthly accidents 153 is considered to indicate the degree of risk of encountering an accident when passing through the road link. In other words, the risk of encountering an accident is high if the number of accidents is large, and the risk of encountering an accident is low if the number is small. Therefore, the route search unit 19 adds the risk time obtained by converting the risk of encountering an accident at the accident occurrence link to the link travel time to the standard link travel time. In addition, this process is good also considering only what is called accident frequent occurrence link whose number of monthly accidents 153 is more than predetermined number among accident occurrence links.

  For example, the route search unit 19 may calculate the travel time of the route including the accident occurrence link by setting the risk time longer as the accident occurrence frequency is higher.

  Moreover, the route search part 19 may weight according to safety priority, when converting the accident occurrence number into risk time as mentioned above. For example, when the route search unit 19 receives a safety priority designation indicating the degree of desirability of a highly secure route in the route search request, the higher the received safety priority, the longer the risk time of the accident occurrence link. Set to calculate the travel time of the route that includes the accident link.

  The safety priority may be, for example, three levels of “low”, “standard”, and “high”. The safety priority is specified when the user makes a route search request.

  Next, a processing procedure in the route search system having the above configuration will be described.

  FIG. 5 is a flowchart showing a processing procedure of route search processing performed by the route search server 1.

  When a user inputs a departure point and a destination point to his / her user terminal device 3, a route search request is sent from the user terminal device 3 to 1.

  The route search unit 19 receives a route search request in which a departure point and a destination point are set (S11).

  The route search unit 19 determines whether or not a safety priority is set for this route search request (S13). When the safety priority is not set (S13: No), the user terminal device 3 is notified to prompt the user to set the safety priority, and the safety priority is set (S15).

  The route search unit 19 extracts one route from the departure point to the destination point according to the route search request in which the safety priority is set (S17). The route search unit 19 refers to the standard link travel time storage unit 17 and specifies the standard link travel time of each road link included in the extracted route (S19). The route search unit 19 determines whether or not the extracted route includes accident-prone links whose number of monthly accidents 153 is equal to or greater than a predetermined number (S21). When an accident-prone link is included, the route search unit 19 determines a risk time for the accident-occurring link according to the safety priority (S23). For example, when the safety priority is “low”, the risk time may be set to zero. When the safety priority is “standard”, the risk time may be the same as the standard link travel time of the road link. That is, in this case, the link travel time of the accident occurrence link is twice the standard link travel time. When the safety priority is “high”, the risk time may be twice as long as the standard link travel time of the road link. That is, in this case, the link travel time of the accident occurrence link is three times the standard link travel time.

  The route search unit 19 calculates the travel time of the target route (S25). At this time, the travel time of the target route may be calculated after adjusting the link travel time of each link according to the traffic jam information included in the road traffic information acquired from the road traffic information providing server 5.

  Steps S17 and subsequent steps are repeated until a predetermined number of routes are extracted for one route search request (S27).

  The route search unit 19 compares the travel times of the predetermined number of routes and selects the route with the shortest travel time (S29).

  Thereby, route selection in consideration of safety can be performed.

  Next, a specific example of route search according to the present embodiment will be described.

  FIG. 6 is a diagram schematically showing a road map from the departure point to the destination point when the departure point and the destination point are set. FIG. 7 is a lookup table relating to road links existing in the map of FIG.

  In the example of FIG. 6, road link # 7 is an accident occurrence link including many accident occurrence points. Therefore, the route search unit 19 may calculate the travel time of each route after creating a lookup table (hereinafter referred to as LUT) as shown in FIG.

  The LUT 100 illustrated in FIG. 7 includes road link No 110, standard link travel time 120, standard risk time 130, safety priority 140, and safe link travel time 150 as data items.

  The route search unit 19 acquires the standard link travel time corresponding to the road link No 110 from the standard link travel time storage unit 17 and sets it as the standard link travel time 120. The standard risk time 130 is a time obtained by converting the risk of encountering an accident into travel time (cost). Here, the standard risk time 130 is a travel time to be added when the safety priority is “standard”, and is set at the same time as the standard link travel time 120. The safety priority 140 is set corresponding to the safety priority designated by the user. Here, “0” is set when the safety priority designated by the user is “low”, “1” is set when “standard”, and “2” is set when “high”.

  The safety link travel time 150 is a link travel time when the safety of each link is considered. Here, it is assumed that the product of the standard risk time 130 and the safety priority 140 is added to the standard link travel time 120. Therefore, the link # 7 is 100 + 100 × 1 = 200, and the safety link travel time 150 is 200 seconds.

  The route search unit 19 may calculate the travel time of each route with reference to the LUT 100 when performing processing according to the flowchart of FIG. As a result, in the example of FIGS. 6 and 7, when safety is not considered, the travel time of route A of # 1- # 4- # 7- # 8- # 11- # 14 is the shortest at 360 seconds. . On the other hand, when safety is considered (safety priority “standard”), the travel time of route A is 460 seconds, and # 1- # 2- # 3- # 6- # 11- # 14 Route B travel time is longer than 400 seconds. Therefore, the route B is selected when safety is taken into consideration.

  According to this embodiment, when a user attaches importance to safety, a route with less accident risk can be presented according to the degree.

  The above-described embodiments of the present invention are examples for explaining the present invention, and are not intended to limit the scope of the present invention only to those embodiments. Those skilled in the art can implement the present invention in various other modes without departing from the gist of the present invention.

  For example, part or all of the functions of the route search server 1 described above may be realized by the user terminal device 3. For example, at least the function of the route search unit 19 may be realized by the user terminal device 3.

DESCRIPTION OF SYMBOLS 1 Route search server 3 User terminal device 5 Road traffic information provision server 11 Map data memory | storage part 13 Accident occurrence link specific process part 15 Accident occurrence link memory | storage part 17 Standard link travel time memory | storage part 19 Route search part

Claims (7)

A map storage unit storing map data including node data relating to nodes indicating intersections and link data relating to road links connecting the nodes;
An accident link storage unit storing an accident occurrence link which is a road link related to the accident occurrence point;
Upon receiving the accident data describing the accident occurrence point and the accident situation in text, the accident data is analyzed by text analysis, the accident occurrence link is identified, and the accident occurrence link specifying means for storing in the accident link storage unit
A route search that accepts a route search request that specifies a departure point and a destination point, and searches for a route with the shortest travel time among one or more routes from the departure point to the destination point based on the map data. And comprising
When calculating the travel time of the route including the accident occurrence link, the route search unit calculates a risk time obtained by converting a risk of encountering an accident at the accident occurrence link into a link travel time, and the link of the accident occurrence link. A navigation device characterized in that a travel time of a route including the accident occurrence link is calculated by adding to a travel time.
In the route search request, when a safety priority designation indicating a degree of desiring a highly secure route is received,
The navigation device according to claim 1, wherein the route search unit sets a longer risk time as the received safety priority is higher, and calculates a travel time of a route including the accident occurrence link.
The accident link storage unit further stores the accident frequency for each accident occurrence link,
The navigation device according to claim 1 or 2, wherein the route search unit sets a longer risk time as the accident occurrence frequency is higher, and calculates a travel time of a route including the accident occurrence link.
The accident occurrence link identifying means identifies a node corresponding to the accident occurrence point, analyzes a text describing the accident situation, identifies a road link when an accident vehicle enters the node, and identifies the identification It has been a road link to the generated link, the navigation device according to claim 1.
Accident link identifying means analyzes the text describing the accident situation, and derives the vector indicating the approach direction of the accident vehicle, identifies the incoming link from the vector road link leading to the nodes, according to claim 4 The navigation device described in 1.
Map storage unit storing map data including node data relating to nodes indicating intersections and link data relating to road links connecting the nodes, and accident link storage storing accident occurrence links that are road links related to accident occurrence points A navigation device comprising a
Upon receiving the accident data describing the accident occurrence point and the accident situation in text, performing a text analysis of the accident data, identifying the accident occurrence link, and storing in the accident link storage unit,
Receiving a route search request specifying a starting point and a destination point;
A step of searching for a route having the shortest travel time among one or more routes from the departure point to the destination point based on the map data, and calculating a travel time of the route including the accident occurrence link The risk time of the accident occurring at the accident link is converted to a link travel time, and the link travel time of the accident link is added to the travel time of the route including the accident link. And a route search method for performing the calculating step.
Map storage unit storing map data including node data relating to nodes indicating intersections and link data relating to road links connecting the nodes, and accident link storage storing accident occurrence links that are road links related to accident occurrence points A computer program for a navigation device comprising a unit,
In the navigation device,
Upon receiving the accident data describing the accident occurrence point and the accident situation in text, performing a text analysis of the accident data, identifying the accident occurrence link, and storing in the accident link storage unit,
Receiving a route search request specifying a starting point and a destination point;
A step of searching for a route having the shortest travel time among one or more routes from the departure point to the destination point based on the map data, and calculating a travel time of the route including the accident occurrence link The risk time of the accident occurring at the accident link is converted to a link travel time, and the link travel time of the accident link is added to the travel time of the route including the accident link. A computer program for executing the calculating step.

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