JPH10300500A - Route searching device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a route searching device capable of accurately and quickly retrieving an optimum route. SOLUTION: In a route searching device in which a plurality of route searching means work in collaboration to search a route, the leading route searching means 301 transmits the result of searching in progress to the following route searching means 305, which in turn outputs an optimum route on the basis of the result. The leading route searching means 301 interrupts the process during searching and transmits the result of searching in progress to the following route searching means 305, which in turn outputs the optimum route on the basis of the result of searching in progress.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a route search device such as a car navigation system, and more particularly, to a device capable of searching for an optimum route accurately and quickly.

[0002]

2. Description of the Related Art Conventionally, as a route search system of a car navigation system, a local system in which an in-vehicle device searches for a route, and a departure place and a destination are notified from an in-vehicle device to a center device, and the route search is calculated in a center. It is known that the center system transmits the calculation result to the on-vehicle device. In addition, by combining these, the center searches for a road network (hereinafter referred to as an infrastructure link network) supported by the center, There is also known a route search method in which the in-vehicle device uses the map data on the in-vehicle device to search the link network. In this combination method, the speed of the route search process can be increased by placing the route calculation means at the center faster than the vehicle-mounted device. Also, if traffic congestion information is grasped at the center, a route search that takes this into account becomes possible.

As shown in FIG. 9, a conventional route search device that implements this combination method includes a navigation terminal 801 mounted on a car and an infrastructure route providing means (that is, an infrastructure link providing means for providing route information on an infrastructure link network). ,Center)
The navigation terminal 801 includes map data recorded on a recording medium, in-vehicle search means for searching for a route using the map data, and display means for displaying the route.

In this apparatus, when searching for a route to a destination, first, the navigation terminal 801 requests the provision of a route to an infrastructure link around the destination, and sends an infrastructure route provision request 803 to the infrastructure route provision means 802. put out. At this time, the navigation terminal 801 selects the destination infrastructure link closest to the destination, and notifies the identifier to the infrastructure route providing means 802 by the infrastructure route provision request 803.

[0005] The infrastructure link referred to here is a link for providing traffic congestion information by a traffic manager or the like. Upon receiving the infrastructure route provision request 803, the infrastructure route providing means 802 takes the traffic congestion state into consideration to reach the destination infrastructure link. , And notifies the navigation terminal 801 of the route result 804 indicating the guide route data indicating the route to the destination infrastructure link and the required time (cost).

When the navigation terminal 801 receives the route from the destination infrastructure link to the destination infrastructure link, the navigation terminal 801 calculates the route from the destination infrastructure link to the destination by the on-vehicle search means. Also displayed.

[0007] In the navigation terminal 801, in order to select a destination infrastructure link, the onboard search means selects the departure point.
A method of once searching between destinations to find a point where the obtained route and the infrastructure link network are connected, and a method of searching for the nearest infrastructure link around the destination are being performed.

[0008]

However, in the conventional route search device, the navigation terminal 801 requests the infrastructure route providing means 802 to provide a route by limiting the infrastructure link near the destination to one. Therefore, a route result that is not always optimal may be provided.

The situation will be described with reference to the road network shown in FIG. In FIG. 8, a road 701 having a width indicates an infrastructure link network, and a road 704 represented by a thin line indicates a non-infralink network. Reference numeral 705 denotes the position of the vehicle on which the navigation terminal is mounted, and reference numeral 707 denotes a road device as an infrastructure route providing means. 706 is a destination, and 702 is a nearest infrastructure link from the destination. Now, it is assumed that traffic congestion 708 has occurred on the infrastructure link between the nearest infrastructure link 702 and the vehicle position 705.

As described above, the navigation terminal 801
Designates the infrastructure link 702 closest to the destination as the destination infrastructure link, and issues an infrastructure route providing request to the infrastructure route providing means 802. Since the infrastructure route providing means 802 receiving this request does not know the position of the destination 706,
The search for the infrastructure route is performed with the infrastructure link 702 as the destination, and the route via the traffic congestion point 708 is guided.

[0011] The purpose of the navigation terminal 801 is to arrive at the final destination 706 as quickly as possible, not to pass through the infrastructure link 702. In this case, the infrastructure route providing means 802 should perform route guidance with another infrastructure link that does not pass through the congestion point 708 as a destination.

To do so, a method of notifying the location information of the destination 706 to the infrastructure route providing means 802 and leaving the selection of another infrastructure link to be the destination to the infrastructure route providing means 802 can be considered.

However, in order to execute this method, it is necessary for the infrastructure route providing means 802 to further have route map data of a non-infrared link network, so that the processing involved in the search becomes heavy and the amount of route data to be held increases. There is a problem that. Also, the numbering method of the non-infrared link network depends on the map format of the navigation terminal 801 and is arbitrarily performed by each manufacturer.
There is also a problem that the route data on the non-infrared link network cannot be communicated between the 801 and the infrastructure route providing means 802 in general.

On the other hand, since the navigation terminal 801 cannot grasp the congestion situation in advance, it is difficult for the navigation terminal itself to select a destination infrastructure link that avoids the congestion.

An object of the present invention is to solve such a problem, and an object of the present invention is to provide a route search device capable of searching for an optimum route accurately and quickly.

[0016]

Therefore, the route search device of the present invention enables the navigation terminal to specify a plurality of candidates as destination infrastructure links. At this time, the navigation terminal is required to provide additional costs (such as required time) from the links listed as candidates to the true destination.
Is calculated, and is notified to the infrastructure route providing means together with the link candidate. The infrastructure route providing means, by this,
Advantageous routes can be quickly calculated by taking into account the costs of the infrastructure link network and the non-infralink network in a comprehensive manner.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS According to a first aspect of the present invention, in a route search device in which a plurality of route search means cooperate to perform a route search, a preceding route search means follows an intermediate result of the search. The route is transmitted to the route searching means, and the subsequent route searching means outputs the optimum route based on the result. The preceding route searching means interrupts the processing in the middle of the search, and outputs the intermediate result to the subsequent route searching means. And the subsequent route searching means outputs an optimum route based on the intermediate result.

According to a second aspect of the present invention, in the route search device of the first aspect, the plurality of route search means search on different route map networks.
The route search result of the map network provided by the preceding search means is used for searching the map network provided by the subsequent search means.

According to a third aspect of the present invention, the preceding route searching means searches on the non-infrastructure link network and determines a plurality of contacts where the non-infrastructure route contacts the infrastructure link network and the cost of the non-infrastructure route. The route is transmitted to the subsequent route searching means, and the subsequent route searching means searches the infrastructure link network, and among the infrastructure routes connected to the contact point, an infrastructure in which the sum of the costs and the arrival cost is minimized. The route is selected and output, and even if the subsequent route searching means has only the infrastructure link network, it includes the non-infrastructure route based on the information given from the preceding route searching means. In addition, it becomes possible to select an infrastructure route that minimizes the arrival cost of the entire route.

According to a fourth aspect of the present invention, the route searching means for searching on the infrastructure link network holds the cost of the infrastructure route through a prior search, and the cost is transmitted from the preceding route searching means. In this case, the total of the arrival costs is obtained by adding the costs, so that the calculation of the arrival costs in the route searching means is simplified, and a quick route search process becomes possible.

According to a fifth aspect of the present invention, the route search means for searching on the infrastructure link network performs the search processing of the route search means for searching on the non-infralink network for the infrastructure route search on the infrastructure link network. Without having to wastefully increase the computational complexity of the route search.
The optimum route can be efficiently searched.

According to a sixth aspect of the present invention, the route search means for searching on a non-infralink network is constituted by a navigation system mounted on a vehicle, and the route search means for searching on the infrastructure link network is provided by a navigation system. And a center device that provides route information to a car navigation system that performs distributed processing in cooperation with a navigation terminal and a center.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First Embodiment) As shown in FIG. 1, a route search device according to a first embodiment includes a navigation terminal 301 that requests a plurality of infrastructure link candidates 306 to provide infrastructure route information. , Route data 307 representing the optimum route to each infrastructure link candidate is stored in the navigation terminal 3
The navigation terminal 301 includes recorded map data 302,
The vehicle includes an in-vehicle search means 303 for searching for a route using the map data 302 and a route display means 304 for displaying the searched route.

The navigation terminal 301 is, for example, an on-vehicle car navigation system, and the infrastructure route providing means (center) 305 is used, for example, to provide the navigation terminal 301 with optimal route information in an infrastructure link network. It has on-road equipment installed alongside the road.

FIG. 2 shows a road network used for explaining the operation of the route search apparatus. In FIG. 2, a road 101 having a width indicates an infrastructure link network, and a road 1 represented by a thin line.
08 indicates a non-infrastructure link network. Numeral 105 indicates the position of the own vehicle on which the navigation terminal 301 is mounted. 107 is an optical beacon road machine of the infrastructure route providing means 305,
It communicates with the vehicle and provides route information in the infrastructure link network. Reference numeral 106 denotes a destination on the non-infrared link network. 102a and 102b are infrastructure link candidates closest to the destination 106, and are links serving as points at which the infrastructure link network shifts to a non-infrastructure link network. Now, it is assumed that traffic congestion occurs on the infrastructure link connecting the infrastructure link candidate 102a and the vehicle position 105.

The infrastructure route providing means 305 prepares guidance route data to be guided and required time (cost) in the form of route data 307 for each infrastructure link ID. In this route data, a route search from the position of the road machine 107, which is the departure point, to each infrastructure link is performed in advance, and the search result is held.
When there is a request for providing an infrastructure route from 301, instead of performing a route search calculation each time, the route data of the corresponding infrastructure link is transmitted from the stored route data to the navigation terminal through the road unit 107. You.

The purpose of the route search is to guide a route that can move from the vehicle position 105 to the destination 106 in the shortest time. In this route search, as shown in FIG. 3, the route on the non-infrared link network near the departure point or the destination is searched by the vehicle-mounted search means 303 of the navigation terminal 301, and the route on the infra link network is provided by the infrastructure route provision. The means 305 searches and provides the search result to the navigation terminal 301. Navigation terminal 301
Is displayed on the route display means 304 by connecting these two routes, and the route guidance is completed.

At this time, the in-vehicle search means 303 obtains a plurality of non-infrastructure routes up to contact with the infrastructure link network and the cost thereof. Calculate each infrastructure route from the departure point side contact point to the destination side contact point with the infrastructure link network and its cost, and optimize the infrastructure route that minimizes the total cost, including the non-infrastructure route, among those infrastructure routes Select as a route.

In the case of the road network shown in FIG. 2, since only the destination 106 is on the non-infralink network, the on-vehicle search means 303 of the navigation terminal 301 first starts from the destination 106 to the infrastructure link near the destination. The route and cost on the non-infrared link network up to 102a and 102b are obtained. These can be obtained in the course of the route search from the destination to the departure point in the course of the bidirectional Dijkstra method, and the cost 103a from the infrastructure link 102a to the destination 106, its route, and the infrastructure link The cost 103b from the destination 102b to the destination 106 and the route thereof can be obtained.

The in-vehicle search means 303 selects the infrastructure links 102a and 102b near the destination obtained as described above as candidates for the infrastructure link on the destination side, interrupts the route search, and determines the destination infrastructure link candidates and their costs. , In the form of an infrastructure link candidate 306.

Due to the nature of the search algorithm based on the Dijkstra method, it is important that a route from each infrastructure link candidate to the destination has been obtained at this point.

The infrastructure route providing means 305 adds the notified infrastructure link candidate 306 to the cost of the route data 306.
And notifies the navigation terminal 301 of the infrastructure link candidate with the lowest total cost and the route data to reach the infrastructure link candidate. Here, it is assumed that the infrastructure link 102b with less traffic congestion is selected and notified.

When receiving the route data from the infrastructure route providing means 305, the navigation terminal 301 determines the destination infrastructure link as 102b. Since the non-infrastructure route from the infrastructure link 102b to the destination 106 has already been obtained when the search by the vehicle-mounted search unit 303 is stopped, the infrastructure provided by the non-infrastructure route and the infrastructure route provision unit 305 is provided. The combination of the route and the route is displayed on the route display means 304. Thus, the optimum route 104 shown in FIG. 2 is displayed.

As described above, this route search apparatus can perform flexible route guidance in which costs of the non-infralink network and the infrastructure link network are comprehensively calculated without performing useless search processing.

As a method of selecting an infrastructure link candidate, for example, only an infrastructure link whose cost from a destination is equal to or less than a certain value is selected as a candidate. It is possible to take such a method that only a few infrastructure links are candidates.

Further, in this embodiment, a case has been described in which a narrow road between the infrastructure link networks becomes a non-infralink network as shown in FIG. 2, but as shown in FIG. Even when the vehicle is located outside the network maintenance area range 602, the optimum route can be searched in the same procedure. At this time, the end point link 601 on the destination side that reaches the outer periphery of the maintenance area range 602 of the infrastructure link network is an infrastructure link candidate.

(Second Embodiment) In a second embodiment, a description will be given of a route search when the departure place and the destination are both on a non-infralink network.

As shown in FIG. 5, a route search device that performs this route search includes a navigation terminal 405 that requests information provision of an infrastructure route by citing an infrastructure link candidate 401 as a starting point and an infrastructure link candidate 402 as an end point. And an infrastructure route providing means 403 for providing a response route 404 responding to the request to the navigation terminal 404. Other components are the same as those in FIG.

In the first embodiment, the point on the infrastructure link where the road unit 107 is installed is determined as the departure point. However, in the second embodiment, when the own vehicle is not located on the infrastructure link network. Is assumed. At this time, the navigation terminal 405 communicates with the infrastructure route search unit 403 using a communication unit such as a mobile phone, and receives the provision of the route data.

In the case of the second embodiment, the same problem as that of the destination of the first embodiment occurs on the departure side. Therefore, the navigation terminal 405 first performs a route search halfway to find a route and cost on each of the departure place and the destination on the non-infralink network from the departure place or the infrastructure link near the destination, The plurality of infrastructure link candidates 401 on the departure side and the plurality of infrastructure link candidates 402 on the destination side are combined with the infrastructure route searching means 403.
To request information on the infrastructure route. It is important at this stage that the route search processing from the departure place or the destination to the infrastructure link candidate has been completed on each of the departure place side and the destination side.

The infrastructure route search means 403 includes a departure-side infrastructure link candidate 401 and a destination-side infrastructure link candidate 4
When 02 is received, a route with the shortest cost is searched between both candidates. Here, if there are n departure-side link candidates and m destination-destination link candidates, there are n × m possible combinations of routes.
It is not necessary to perform a route search for all the combinations, and by taking over the route search performed by the navigation terminal 405 on the infrastructure link network, an optimum route can be efficiently searched.

This will be described with reference to FIG. In FIG. 6, S represents a departure place, G represents a destination, A1 to A3 represent start ends of origin link candidates, and B1 to B3 represent end ends of end link candidates. The navigation terminal 405 includes a route between S (departure point) and A1, a path between S and A2, a path between S and A3 and their costs, and a route between B1 and G (destination), between B2 and G, and between B3 and B3.
The route between -G and its cost have already been obtained, and the result is notified to the infrastructure route searching means 403.

The infrastructure route search means 403 is a node (for example, A1) reachable from a certain node (for example, A1).
The total arrival cost up to 2) is obtained, and the node (A
Only when the node 2 cannot reach from another node (S or A3) at a lower cost, the process of registering the own node number (A1) and the arrival cost is continued.

Through this processing, the infrastructure route searching means 403 obtains an infrastructure route between the originating link and the end link which realizes the minimum cost, and returns the result to the answering route 404.
To the navigation terminal 405.

The navigation terminal 405 determines the infrastructure route between the start link and the end link provided by the infrastructure route providing means 403 and the departure point and the end point link from the start link obtained by the search by the vehicle-mounted search means. The non-infrastructure route from the route to the destination is displayed together with the route display means.

As described above, in the route search device of the second embodiment, the amount of calculation for the route search is not unnecessarily increased by the cooperative operation of the route search means on the vehicle-mounted device side and the infrastructure route search means on the center side. , The optimal route can be calculated efficiently.

In this route search method, as shown in FIG. 7, a plurality of infrastructure link network maintenance areas 602a and 602 are provided.
b, and the exclusive use of the infrastructure link network in each area is provided with an exclusive infrastructure route searching means. The communication can be performed in one area using the arrival cost of the link connecting the two areas as a medium. By taking over the searched infrastructure route in the other area, it is possible to efficiently search for the optimal route.

[0049]

As is clear from the above description, in the route search device of the present invention, when the navigation terminal and the center side perform the route search processing in a distributed manner, the navigation terminal can reach the boundary of the search range. Is obtained and the arrival cost is transmitted as a parameter to the center side, whereby the optimum route can be efficiently and accurately calculated.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a route search device according to a first embodiment of the present invention;

FIG. 2 is a road network map for explaining the operation of the route search device according to the first embodiment of the present invention;

FIG. 3 is a schematic explanatory diagram of a route search method in the route search device according to the embodiment of the present invention;

FIG. 4 is an explanatory diagram showing an infrastructure link network maintenance area to which the search method of the route search device according to the first embodiment can be applied;

FIG. 5 is a configuration diagram of a route search device according to a second embodiment of the present invention;

FIG. 6 is an explanatory diagram showing a search method in the route search device according to the second embodiment of the present invention;

FIG. 7 is an explanatory diagram showing an infrastructure link network maintenance area to which the search method of the route search device according to the second embodiment can be applied;

FIG. 8 is a road network map for explaining the operation of the conventional route search device;

FIG. 9 is a configuration diagram of a conventional route search device.

[Explanation of symbols]

 101, 701 Infrastructure link network 102, 402 Destination-side infrastructure link candidate 103 Reaching cost 104 Optimal route 105, 705 Own vehicle position 106, 706 Destination 107, 707 Road machine 108, 704 Non-infrastructure link network 301, 405 Navigation terminal 302 Map data 303 In-vehicle search means 304 Route display means 305, 403 Infrastructure link route providing means 306, 601 Infrastructure link candidates 307 Route data 401 Departure side infrastructure link candidates 404 Answer route 602 Infrastructure link network boundary 702 Destination infrastructure link 703 Guidance route 708 Traffic jam

Claims (6)

[Claims] 1. A route search device in which a plurality of route search means perform a route search in cooperation with each other, wherein a preceding route search means transmits an intermediate result of the search to a subsequent route search means, and the subsequent route search means performs the search. A route search device for outputting an optimum route based on a result. 2. The route search device according to claim 1, wherein the plurality of route search means search on different route map networks. 3. The route searching means, wherein the preceding route searching means searches on a non-infrastructure link network, and a plurality of contacts where the non-infrastructure route contacts the infrastructure link network and the cost of the non-infrastructure route follow. The subsequent route search means searches on the infrastructure link network and selects an infrastructure route that minimizes the total arrival cost including the cost from among the infrastructure routes connected to the contact point. The route search device according to claim 1, wherein the route search device outputs the information. 4. A route searching means for searching on the infrastructure link network holds a cost of the infrastructure route through a prior search, and calculates the cost and the cost transmitted from the preceding route searching means. The route search device according to claim 3, wherein a sum of the arrival costs is obtained by adding. 5. A route search means for searching on the infrastructure link network, wherein the search processing of the route search means for searching on the non-infralink network is taken over on the infrastructure link network for the infrastructure route search. The route search device according to claim 3, wherein: 6. The route search means for searching on the non-infralink network comprises a navigation system mounted on a car, and the route search means for searching on the infralink network provides route information to the navigation system. The route search device according to claim 3, further comprising a center device that performs the search.