WO2013145128A1

WO2013145128A1 - Route search device, control method, and program

Info

Publication number: WO2013145128A1
Application number: PCT/JP2012/057950
Authority: WO
Inventors: 賢二恒川; 詩紋居坂; 喬浩鎌田
Original assignee: パイオニア株式会社
Priority date: 2012-03-27
Filing date: 2012-03-27
Publication date: 2013-10-03

Abstract

The route search device of the present invention has a route setting means and an inter-vehicle distance information acquiring means. The route setting means sets a route from a departure point to an arrival point. The inter-vehicle distance information acquiring means acquires inter-vehicle distance information which is information relating to the distance between moving bodies headed in the same direction, in predetermined sections included in a route. The route setting means then sets the route described above on the basis of the inter-vehicle distance information.

Description

Route search apparatus, control method, and program

The present invention relates to route search technology.

Conventionally, when performing a route search, a technique for searching for an optimal route from the starting point to the destination using the Dijkstra method or an algorithm applied thereto is known. For example, Patent Document 1 adds a cost that is an index of difficulty of passing through a road (link) from a certain branch point (node) to the next branch point on the route, and adds up the cost. A technique for determining a route that minimizes the optimum route as an optimum route is disclosed.

JP 09-178500 A

As in the past, when searching for an optimal route using costs related to travel time, costs related to travel distance, costs related to tolls, etc., when actually traveling on the optimal route obtained by route search, the density of vehicles traveling is high. In some cases, it was crowded and difficult to travel.

The present invention has been made to solve the above problems, and provides a route search device, a control method, and a program capable of appropriately executing a route search in consideration of the density of a traveling vehicle. The main purpose.

In the first aspect of the present invention, the route setting means for setting the route from the departure point to the arrival point, and the inter-vehicle distance that is information on the distance between the moving bodies heading in the same direction in each predetermined section included in the route Vehicle distance information acquisition means for acquiring distance information, wherein the route setting means sets the route based on the vehicle distance information.

The invention according to claim 11 is a control method executed by the route search device, the route setting step for setting a route from the departure point to the arrival point, and the same direction in each predetermined section included in the route An inter-vehicle distance information acquisition step of acquiring inter-vehicle distance information, which is information relating to the distance between mobile bodies facing the vehicle, wherein the route setting step sets the route based on the inter-vehicle distance information. To do.

The invention according to claim 12 is a program executed by the route search device, wherein the route setting means for setting a route from the departure point to the arrival point and a predetermined section included in the route in the same direction Causing the route search device to function as an inter-vehicle distance information acquisition unit that acquires inter-vehicle distance information that is information related to a distance between mobile bodies that are headed, and the route setting unit sets the route based on the inter-vehicle distance information. Features.

1 shows a schematic configuration of a route search system. 1 shows a schematic configuration of a probe information providing apparatus. 1 shows a schematic configuration of a server device. 1 shows a schematic configuration of a client terminal. The data structure of the inter-vehicle distance statistical information is shown. It is a flowchart which shows the process sequence which the control part of a probe information provision apparatus performs. It is a flowchart which shows the procedure of the production | generation process of the inter-vehicle distance statistical information which the control part of a server apparatus performs. It is an example of the flowchart which shows the procedure of the route search process which the control part of a server apparatus performs. It is a flowchart which shows the process sequence which a client terminal performs. A graph is shown in which node S is the departure point, node G is the destination, and nodes A and B are intermediate points. The data structure of the inter-vehicle distance statistical information which concerns on a modification is shown. It is a flowchart which shows the process sequence which the control part of a client terminal performs in a modification. It is a table which shows the relationship between the average inter-vehicle distance and the display form of a link.

In one preferred embodiment of the present invention, the route search device includes route setting means for setting a route from a departure point to an arrival point, and mobiles heading in the same direction in each predetermined section included in the route. Inter-vehicle distance information acquisition means for acquiring inter-vehicle distance information, which is information relating to the distance, and the route setting means sets the route based on the inter-vehicle distance information.

The route search device includes route setting means and inter-vehicle distance information acquisition means. The route setting means sets a route from the departure point to the arrival point. The inter-vehicle distance information acquisition means acquires inter-vehicle distance information, which is information related to the distance between moving bodies heading in the same direction in each predetermined section included in the route. The route setting means sets the above-described route based on the inter-vehicle distance information. By doing in this way, the route search device can search and set an optimal route in consideration of the density of the traveling vehicle.

In one aspect of the route search device, the inter-vehicle distance information is information related to a distance in the front-rear direction between moving bodies that are traveling in the same lane and are positioned in the front-rear direction. By doing in this way, the route search device can search and set an optimum route in consideration of the density of the traveling vehicle in the same lane.

In another aspect of the route search device, the inter-vehicle distance information is an average value of the distances between the moving bodies. By doing in this way, the route search device can set a route with a longer distance between vehicles and less risk of collision or contact than past statistics.

In another aspect of the route search device, the route setting means selects a route having a minimum combined value of the passing difficulty index in each section of the route from the departure point to the arrival point. The indicator is weighted with a coefficient having a negative correlation with the value indicated by the inter-vehicle distance information in the corresponding section. By doing in this way, the route search device can set a route that is easy to drive with a longer inter-vehicle distance by increasing the difficulty index as the section having a shorter inter-vehicle distance.

In another aspect of the route search device, the inter-vehicle distance information acquisition unit acquires, from the mobile body, information on the distance to the front mobile body measured by the mobile body traveling in each section. Generate inter-vehicle distance information. By doing in this way, the route search apparatus can receive the information on the distance from the moving body traveling in various sections to the moving body ahead, and can suitably generate the inter-vehicle distance information.

In another aspect of the route search device, the route setting unit measures a time zone in which the vehicle is expected to travel in the section when traveling according to the route, and a distance between the moving bodies in the section. The inter-vehicle distance information used for setting the route is determined based on the time zone. In general, the degree of congestion on each road may vary from time to time. Therefore, according to this aspect, the route search device can appropriately select the inter-vehicle distance information to be used based on the time zone, and can perform the route search reflecting the density of the traveling vehicle more accurately.

In another aspect of the route search device, the route setting unit is configured to set the route based on a moving direction or / and a traveling lane of the moving body when the distance between the moving bodies is measured. Determine distance information. According to this aspect, the route search device appropriately selects the inter-vehicle distance information to be used based on the moving direction or / and the traveling lane of the moving object at the time of measurement, and performs the route search that more accurately reflects the density of the traveling vehicle. It can be carried out.

In another aspect of the route search device, the inter-vehicle distance information acquisition unit, when there is a section in which the inter-vehicle distance information cannot be acquired, among the sections included in the route, The inter-vehicle distance information is estimated based on the inter-vehicle distance information of the section in which the inter-vehicle distance information continuous to the section where the inter-vehicle distance information cannot be acquired. According to this aspect, even when there is a section in which inter-vehicle distance information cannot be acquired, the route search device can preferably generate inter-vehicle distance information and set a route based on the inter-vehicle distance information.

In another aspect of the route search device, the inter-vehicle distance information acquisition means sets an upper limit value to a value indicated by the inter-vehicle distance information. In general, when the inter-vehicle distance is sufficiently long, the ease of driving does not change depending on the inter-vehicle distance. Therefore, according to this aspect, the route search device can suppress an excessive variation in the value of the inter-vehicle distance information, and can appropriately perform a route search according to the ease of actual driving.

In another aspect of the route search device, the inter-vehicle distance information acquisition means, when there is a section in which the inter-vehicle distance information cannot be acquired among the sections included in the route, Is set to the upper limit value. In general, it is presumed that the section where the inter-vehicle distance information cannot be acquired is a section where the vehicle does not pass so much and the density of the traveling vehicle is low. Therefore, according to this aspect, the route search device can appropriately generate the inter-vehicle distance information.

In another preferred embodiment of the present invention, there is provided a control method executed by the route search device, the route setting step for setting a route from the departure point to the arrival point, and in each predetermined section included in the route, An inter-vehicle distance information acquisition step of acquiring inter-vehicle distance information, which is information relating to the distance between moving bodies heading in the same direction, wherein the route setting step sets the route based on the inter-vehicle distance information. Features. By using this control method, the route search device can search and set an optimal route in consideration of the density of the traveling vehicle.

In another preferred embodiment of the present invention, a program executed by the route search device, the route setting means for setting a route from the departure point to the arrival point, and the same in each predetermined section included in the route The route search device is caused to function as an inter-vehicle distance information acquisition unit that acquires inter-vehicle distance information that is information relating to a distance between moving bodies that travel in a direction, and the route setting unit sets the route based on the inter-vehicle distance information. . By executing this program, the route search device can search and set an optimal route in consideration of the density of the traveling vehicle. Preferably, the program is stored in a storage medium.

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

[Schematic configuration]
FIG. 1 shows a schematic configuration of a route search system according to the present embodiment. The route search system according to the present embodiment is a system that performs route search in consideration of statistical information of the inter-vehicle distance. As shown in FIG. 1, the route search system includes a probe information providing device 100 including an inter-vehicle distance sensor 102, a server device 200 that performs route search, and a client terminal 300 that makes a route search processing request to the server device 200. And have. Hereinafter, a specific configuration for each component of the route search system will be described.

(1) Configuration of Probe Information Providing Device FIG. 2 shows a schematic configuration of the probe information providing device 100. The probe information providing apparatus 100 is, for example, an in-vehicle navigation apparatus, and includes an inter-vehicle distance sensor 102, a GPS receiver 103, a storage unit 104, a control unit 105, and a communication unit 106, as shown in FIG. Have. The inter-vehicle distance sensor 102, the GPS receiver 103, the storage unit 104, the control unit 105, and the communication unit 106 are connected to each other via the bus line 101.

The inter-vehicle distance sensor 102 is an inter-vehicle distance (also referred to as an “inter-vehicle distance Lb”) between a vehicle on which the probe information providing apparatus 100 is mounted and a vehicle traveling in the same lane as the vehicle and traveling in front of the vehicle. measure. The inter-vehicle distance sensor 102 may measure the inter-vehicle distance Lb using an ultrasonic wave or a laser, or may measure the inter-vehicle distance Lb by analyzing an image of a camera that captures the front of the vehicle.

The GPS receiver 103 receives radio waves carrying downlink data including positioning data from a plurality of GPS satellites. The positioning data is used to detect the absolute position (current position) of the vehicle from latitude and longitude information.

The storage unit 104 is configured by, for example, an HDD or the like, and based on the control of the control unit 105, information on the inter-vehicle distance Lb measured by the inter-vehicle distance sensor 102, time information at the time of measurement, and position information at the time of measurement ( These are collectively referred to as “sensor information Is”).

The control unit 105 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, and performs overall control of the probe information providing apparatus 100. Specific control will be described in detail in the [Control Method] section with reference to FIG.

The communication unit 106 transmits a probe traffic information signal including the sensor information Is (also referred to as “probe information signal S1”) to the server device 200 based on the control of the control unit 105. Here, the communication unit 106 is, for example, a mobile phone or a dedicated communication card.

(2) Configuration of Server Device FIG. 3 shows a schematic configuration of the server device 200. As illustrated in FIG. 3, the server device 200 includes a storage unit 204, a control unit 205, and a communication unit 206. The storage unit 204, the control unit 205, and the communication unit 206 are connected to each other via the bus line 201.

The storage unit 204 is configured by, for example, an HDD and stores various data used for route search processing such as map data. The map data includes road data represented by links corresponding to roads and nodes corresponding to road connecting portions (intersections), facility information about each facility, and the like. Furthermore, the storage unit 204 stores sensor information Is included in the probe information signal S1 based on the control of the control unit 205. In addition, the storage unit 204 is based on the control of the control unit 205, and the link identification information (also referred to as “link ID”) and the average value for each link ID of the inter-vehicle distance Lb included in the sensor information Is (“average inter-vehicle distance”). A database (also referred to as “inter-vehicle distance statistical information Isdb”) associated with “distance ALb” is stored. The average inter-vehicle distance ALb is an example of “inter-vehicle distance information” in the present invention, and is used for weighting a link cost, which is an index of difficulty of passing through a road corresponding to each link.

FIG. 5 shows the data structure of the inter-vehicle distance statistical information Isdb. As shown in FIG. 5, the inter-vehicle distance statistical information Isdb is associated with an average inter-vehicle distance ALb for each link ID. For example, according to the inter-vehicle distance statistical information Isdb shown in FIG. 5, the average inter-vehicle distance ALb on the road corresponding to the link ID “2245” is “1 m” and the average inter-vehicle distance on the road corresponding to the link ID “2246”. The distance ALb is “15 m”, and the average inter-vehicle distance ALb on the road corresponding to the link ID “2247” is “100 m”. Thus, in the inter-vehicle distance statistical information Isdb, the average inter-vehicle distance ALb is associated with each link ID.

Preferably, an upper limit “LimLb” (for example, 100 m) is provided in advance for the average inter-vehicle distance ALb. The above-described upper limit value LimLb is set to the inter-vehicle distance Lb that does not hinder the presence of the forward vehicle in driving, and is set in advance based on, for example, experiments. Further, the corresponding average inter-vehicle distance ALb is set to the upper limit value LimLb even for a link ID that does not have information on the inter-vehicle distance Lb that is a sample for calculating the average inter-vehicle distance ALb.

The control unit 205 includes memories such as a CPU, a ROM, and a RAM, and performs overall control of the server device 200 by executing a program stored in the memory. The control unit 205 generates or updates the inter-vehicle distance statistical information Isdb based on the sensor information Is of the received probe information signal S1 at predetermined time intervals. This specific control will be described in detail with reference to FIG. 7 in the [Control Method] section.

Further, the control unit 205 searches for an optimum route having a minimum link cost among routes from the departure point to the destination. At this time, when calculating the link cost of each link, the control unit 205 has a coefficient having a negative correlation with the average inter-vehicle distance ALb (“inter-vehicle distance coefficient Cb”) with respect to the link cost calculated in consideration of the passage time and the like. Also weighted by multiplying. This specific control will be described in detail with reference to FIG. 8 in the [Control Method] section.

The communication unit 206 transmits and receives various data based on the control of the control unit 205. For example, the communication unit 206 receives the probe information signal S1 from the probe information providing apparatus 100. In addition, the communication unit 206 receives from the client terminal 300 a signal (also referred to as “route search request signal S2”) to execute a route search specifying a departure place and a destination. Further, the communication unit 206 transmits a signal (also referred to as “route search result signal S <b> 3”) indicating a route search execution result such as optimal route information and required time to the client terminal 300.

The server device 200 is an example of a “route search device” in the present invention, and the control unit 205 is an example of a “route setting unit” and an “inter-vehicle distance information acquisition unit” in the present invention.

(3) Configuration of Client Terminal FIG. 4 shows a schematic configuration of the client terminal 300. The client terminal 300 is, for example, an in-vehicle navigation device, a portable terminal, or a personal computer. As shown in FIG. 4, the input unit 303, the storage unit 304, the control unit 305, the communication unit 306, and the display unit. 307. The input unit 303, the storage unit 304, the control unit 305, the communication unit 306, and the display unit 307 are connected to each other via the bus line 301.

The input unit 303 is a button, a remote controller, a mouse, a keyboard, or the like, and accepts an input for designating a starting point and a destination used for route search. When the client terminal 300 is a navigation device having a GPS receiver, the input unit 303 may accept only an input for designating a destination. In this case, the departure place is set to the current position measured by the GPS receiver.

The storage unit 304 is configured by, for example, an HDD. When the client terminal 300 is a navigation device, various data used for navigation processing such as map data are stored.

The control unit 305 has a memory such as a CPU, a ROM, and a RAM, and performs overall control of the client terminal 300 by executing a program stored in the memory. Specific control will be described in detail in the [Control Method] section with reference to FIG.

The communication unit 306 transmits a route search request signal S2 designating a departure place and a destination to the server device 200 under the control of the control unit 305. Further, the communication unit 306 receives the route search result signal S3 from the server device 200.

The display unit 307 displays various display data on a display or the like under the control of the control unit 305. For example, when the communication unit 306 receives the route search result signal S3, the display unit 307 displays the optimum route indicated by the route search result signal S3 on the map or the necessity of the optimum route based on the control of the control unit 305. Or display time.

[Control method]
Next, processing executed by the probe information providing apparatus 100, the server apparatus 200, and the client terminal 300 will be specifically described with reference to flowcharts shown in FIGS.

(1) Process Performed by Probe Information Providing Apparatus FIG. 6 is an example of a flowchart showing a process procedure performed by the control unit 105 of the probe information providing apparatus 100.

First, the control unit 105 determines whether there is a power-off request (step S101). And when there exists a power-off request | requirement (step S101: Yes), the control part 105 complete | finishes the process of a flowchart. On the other hand, when there is no power-off request (step S101: No), the control unit 105 advances the process to step S102.

Next, the control unit 105 determines whether or not the present time is the acquisition timing of the sensor information Is (step S102). For example, when acquiring the sensor information Is for each predetermined time width, the control unit 105 determines whether or not the above-described time width has elapsed since the last time sensor information Is was acquired. If it is determined that the present time is the acquisition timing of the sensor information Is (step S102: Yes), the control unit 105 acquires the sensor information Is and stores it in the storage unit 104 (step S103). Specifically, the control unit 105 generates, as sensor information Is, the inter-vehicle distance Lb acquired by the inter-vehicle distance sensor 102, the position information acquired by the GPS receiver 103, and time information indicating the measurement date and time of the inter-vehicle distance Lb. And stored in the storage unit 104. On the other hand, when it is determined that the present time is not the acquisition timing of the sensor information Is (step S102: No), the control unit 105 returns the process to step S101.

Next, the control unit 105 determines whether or not the present time is the transmission timing of the sensor information Is (step S104). For example, when the sensor information Is is transmitted to the server device 200 every predetermined time width, the control unit 105 determines whether or not the above-described time width has elapsed since the last transmission of the sensor information Is. If it is determined that the present time is the transmission timing of the sensor information Is (step S104: Yes), the control unit 105 extracts the sensor information Is that has not been transmitted to the server device 200 from the storage unit 104, and sets it as the probe information signal S1 It transmits to the server apparatus 200 (step S105). And the control part 105 returns a process to step S101. On the other hand, when the present time is not the transmission timing of the sensor information Is (step S104: No), the control unit 105 returns the process to step S101.

As described above, when the control unit 105 executes the process of the flowchart illustrated in FIG. 6, the server apparatus 200 suitably receives the sensor information Is including the inter-vehicle distance Ls from each of the plurality of probe information providing apparatuses 100. Can be acquired.

(2) Processing executed by server device The control unit 205 of the server device 200 individually performs the generation processing of the inter-vehicle distance statistical information Isdb and the route search processing based on the route search request signal S2. Hereinafter, each of these processes will be described.

(2-1) Generation Processing of Inter-vehicle Distance Statistical Information FIG. 7 is an example of a flowchart illustrating a procedure of generation processing of inter-vehicle distance statistical information Isdb executed by the control unit 205 of the server device 200.

First, the control unit 205 determines whether or not a power-off request has been made (step S201). And when there exists a power-off request | requirement (step S201: Yes), the control part 205 complete | finishes the process of a flowchart. On the other hand, when there is no power-off request (step S201: No), the control unit 205 advances the process to step S202.

Next, the control unit 205 determines whether or not the probe information signal S1 has been received from the probe information providing apparatus 100 (step S202). When the control unit 205 receives the probe information signal S1 from the probe information providing apparatus 100 (step S202: Yes), the control unit 205 stores the sensor information Is included in the received probe information signal S1 in the storage unit 204 (step S203). ). On the other hand, the control part 205 returns a process to step S201, when the probe information signal S1 is not received from the probe information provision apparatus 100 (step S202: No).

Next, the control unit 205 determines whether or not the present time is the timing for creating the database of the sensor information Is (step S204). For example, when updating the average inter-vehicle distance ALb of the inter-vehicle distance statistical information Isdb for each predetermined time width, the control unit 205 determines whether or not the above-described time width has elapsed since the previous update. If the present time is the timing for creating the database of the sensor information Is (step S204: Yes), the control unit 205 advances the process to step S205. On the other hand, when the present time is not the timing for creating the database of the sensor information Is (step S204: No), the control unit 205 returns the process to step S201.

Next, the control unit 205 generates inter-vehicle distance statistical information Isdb (step S205). In this case, the control unit 205 first extracts the sensor information Is to be calculated from the storage unit 204, then refers to the road data, and each sensor information Is is generated from the position information included in the sensor information Is. A link ID corresponding to a road is recognized. Next, the control unit 205 calculates an average inter-vehicle distance ALb that is an average value of the inter-vehicle distance Lb included in the corresponding sensor information Is for each link ID.

At this time, the control unit 205 sets the value of the average inter-vehicle distance ALb exceeding the upper limit value LimLb to the upper limit value LimLb. In general, when the inter-vehicle distance is sufficiently long, the ease of driving does not change depending on the inter-vehicle distance. Therefore, the control unit 205 can suppress unnecessary variation of the average inter-vehicle distance ALb by providing the upper limit value LimLb for the average inter-vehicle distance ALb.

Further, the control unit 205 sets the average inter-vehicle distance ALb of the link ID having no information of the inter-vehicle distance Lb as a sample for calculating the average inter-vehicle distance ALb to the upper limit value LimLb. In general, it is presumed that the road where the sensor information IS cannot be acquired is a section where the vehicle does not pass so much and the density of the traveling vehicle is low. Accordingly, this enables the control unit 205 to appropriately set the average inter-vehicle distance ALb for all link IDs. And the control part 205 returns a process to step S201 after execution of step S205.

(2-2) Route Search Processing FIG. 8 is an example of a flowchart showing the procedure of route search processing executed by the control unit 205 of the server apparatus 200.

First, the control unit 205 determines whether or not there is a power-off request (step S301). And when there exists a power-off request | requirement (step S301: Yes), the control part 205 complete | finishes the process of a flowchart. On the other hand, when there is no power-off request (step S301: No), the control unit 205 advances the process to step S302.

Next, the control unit 205 determines whether or not the route search request signal S2 designating the departure place and the destination is received (step S302). When the route search request signal S2 is received (step S302: Yes), the control unit 205 starts route search processing using the Dijkstra method or the like (step S303). Specifically, the control unit 205 executes processing from step S304 to step S307 described later. On the other hand, the control part 205 returns a process to step S301, when not receiving route search request signal S2 (step S302: No).

Next, in step S304, the control unit 205 calculates a link cost for the link of the candidate route (step S304). For example, the control unit 205 determines, for each target link, a cost related to the time for passing the link, a cost related to the distance of the link, a cost related to a toll such as a toll road, a cost related to a road type such as a main road and a vehicle width A link cost is calculated by multiplying each cost by a predetermined ratio. At this time, when route search conditions such as time priority and distance priority are defined in the route search request signal S2, the control unit 205 sets a large ratio to multiply the cost for which priority is specified. Above, link cost is calculated. Note that the average inter-vehicle distance ALb is not taken into account in the link cost calculated in step S304.

Next, the control unit 205 weights the link cost by the inter-vehicle distance coefficient Cb (step S305). Specifically, first, the control unit 205 calculates an inter-vehicle distance coefficient Cb having a negative correlation with the average inter-vehicle distance ALb associated with the target link with reference to a predetermined formula or the like. For example, the inter-vehicle distance coefficient Cb may be a reciprocal of the average inter-vehicle distance ALb. Next, the control unit 205 multiplies the link cost calculated in step S304 by the inter-vehicle distance coefficient Cb.

In general, the smaller the inter-vehicle distance Lb, the more the driver needs to drive while paying attention to the vehicle ahead, and the driver is stressed. In addition, the smaller the inter-vehicle distance Lb, the higher the possibility of contact with the preceding vehicle. In consideration of the above, in step S306, the control unit 205 increases the link cost for a link having a smaller average inter-vehicle distance ALb. Thereby, the control part 205 can set link cost appropriately according to a driver | operator's sense.

Then, the control unit 205 searches for a route that minimizes the weighted link cost (step S306). As a result, the control unit 205 recognizes the sum of the optimum route from the departure point to the target node and the link cost. Next, the control unit 205 determines whether or not the route search is completed (step S307). In other words, the control unit 205 determines whether the optimum route from the departure point to the destination has been identified. When the route search is completed (step S307: Yes), the control unit 205 transmits a route search result signal S3 to the client terminal 300 (step S308). Specifically, the control unit 205 transmits information on the optimum route from the specified departure place to the destination, information on the time required for the optimum route, and the like as the route search result signal S3 to the client terminal 300. Then, the control unit 205 returns the process to step S301. On the other hand, when the route search is not completed (step S307: No), that is, when the destination does not exist in the vicinity of the identified optimum route, the control unit 205 adds a node to be searched for the optimum route. Then, the process of step S304 is performed again.

(3) Process Performed by Client Terminal FIG. 9 is a flowchart showing a process procedure performed by the client terminal 300.

First, the control unit 305 determines whether or not there is a power-off request (step S401). And when there exists a power-off request | requirement (step S401: Yes), the control part 305 complete | finishes the process of a flowchart. On the other hand, when there is no power-off request (step S401: No), the control unit 305 advances the process to step S402.

Next, the control unit 305 determines whether or not a departure place and a destination are set (step S402). Specifically, the control unit 305 determines whether or not there is an input from the input unit 303 specifying a departure place, a destination, and the like. When the client terminal 300 has a GPS receiver, the control unit 305 may set the departure point to the current location measured by the GPS receiver regardless of the input of the input unit 303. Further, the control unit 305 may accept input regarding route search conditions such as charge priority and distance priority from the input unit 303 in addition to the departure point and destination. And when a departure place, a destination, etc. are set (step S402: Yes), the control part 305 advances a process to step S403. On the other hand, when the departure place or the destination is not set (step S402: No), the control unit 305 returns the process to step S401.

Next, the control unit 305 transmits a route search request signal S2 designating a departure place and a destination to the server device 200 (step S403). Then, the control unit 305 determines whether or not the route search result signal S3 is received from the server device 200 (step S404). And control part 305 displays a route search result based on route search result signal S3, when route search result signal S3 is received from server apparatus 200 (Step S404: Yes) (Step S405). For example, based on the route search result signal S3, the control unit 305 displays the optimum route together with the map on the display unit 307, or displays the time required for the optimum route or / and information on the waypoints passing through the display unit 307. To do. And after execution of step S405, or when the control part 305 has not received route search result signal S3 (step S404: No), the control part 305 returns a process to step S401.

[effect]
Next, the effect of the present embodiment will be supplementarily described with reference to FIG. FIG. 10 shows a graph in which the node S is a departure point, the node G is a destination, and the nodes A and B are intermediate points. In FIG. 10, the link cost “LCbef” before weighting by the inter-vehicle distance coefficient Cb and the inter-vehicle distance coefficient Cb are set for the links connecting the nodes.

In this case, when searching for a route that minimizes the sum of the link costs LCbef before weighting, the sum of the link weights LCbef before weighting of the routes passing through the nodes S, A, and G is 7 (= 3 + 4). , The total value of the link weight LCbef before weighting of the route passing through the node S, the node B, and the node G is 6 (= 4 + 2). Therefore, in this case, the path with the minimum sum of the link costs LCbef is a path that passes through the node S, the node B, and the node G. However, this route includes links ending with node B and node G having a relatively large inter-vehicle distance coefficient Cb of “3.0”. Therefore, in this case, when the vehicle actually travels along this route, a situation occurs in which the amount of traffic is large and it is difficult to drive.

On the other hand, when searching for a route that minimizes the sum of the link costs after weighting by the inter-vehicle distance coefficient Cb, the sum of the link costs of the routes passing through the nodes S, A, and G is 7.0 (= 3 × 1.0 + 4 × 1.0), and the total value of the link cost of the route passing through the nodes S, B, and G is 10.0 (= 4 × 1.0 + 2 × 3.0). Therefore, in this case, the route having the minimum sum of the weighted link costs LCaft is a route passing through the node S, the node A, and the node G. As described above, according to the present embodiment, the control unit 205 can select a route having a statistically long inter-vehicle distance Lb and a small risk of rear-end collision or contact as the optimum route.

[Modification]
Hereinafter, modified examples suitable for the above-described embodiments will be described. The following modifications may be applied in any combination to the above-described embodiments.

(Modification 1)
The data structure of the inter-vehicle distance statistical information Isdb is not limited to that shown in FIG. Instead, the inter-vehicle distance statistical information Isdb may further define the relationship between the link ID and the average inter-vehicle distance ALb based on other items.

FIG. 11A shows inter-vehicle distance statistical information Isdb that defines the relationship between the link ID and the average inter-vehicle distance ALb for each time zone. In FIG. 11A, the average inter-vehicle distance ALb is determined for each link ID every four time zones, that is, every six hours. In this case, the control unit 205 recognizes the time zone in which the inter-vehicle distance Lb indicated by each sensor information Is is calculated based on the time information included in the sensor information Is, so that the average inter-vehicle distance ALb in each time zone is obtained. calculate. In this case, for example, the route search request signal S2 includes information specifying a scheduled time zone, and the server device 200 calculates the inter-vehicle distance coefficient Cb based on the specified time zone during the route search process. The average inter-vehicle distance ALb used for calculation is selected. The inter-vehicle distance statistical information Isdb may define the relationship between the link ID and the average inter-vehicle distance ALb for each day of the week instead of or in addition to the time zone.

FIG. 11B shows inter-vehicle distance statistical information Isdb that defines the relationship between the link ID and the average inter-vehicle distance ALb for each traveling direction. In FIG. 11 (B), the average inter-vehicle distance ALb is determined for each link ID depending on whether it is an up lane or a down lane. In this case, the probe information providing apparatus 100 further adds information on the traveling direction to the probe information signal S1, and the control unit 205 recognizes the traveling direction on the target link based on the information, thereby An average inter-vehicle distance ALb in the traveling direction is calculated. In this case, the control unit 205 of the server device 200 selects the average inter-vehicle distance ALb used for calculating the inter-vehicle distance coefficient Cb based on the moving direction when passing through each link during the route search process.

FIG. 11C shows inter-vehicle distance statistical information Isdb that defines the relationship between the link ID and the average inter-vehicle distance ALb for each lane. In FIG. 11B, the average inter-vehicle distance ALb is determined for each link ID depending on whether the vehicle is a traveling lane or an overtaking lane. In this case, the control unit 205 calculates the average inter-vehicle distance ALb for each recognized lane, for example, by recognizing which of the driving lane or the overtaking lane was traveling based on the position information included in the sensor information Is. In this case, for example, the route search request signal S2 includes information designating which of the driving lane and the overtaking lane is preferentially traveled, and the server device 200 adds the specified lane in the route searching process. Based on this, the average inter-vehicle distance ALb used for calculating the inter-vehicle distance coefficient Cb is selected.

As described above, the server device 200 has the inter-vehicle distance statistical information Isdb in which the relationship between the link ID and the average inter-vehicle distance ALb is defined in detail by other items, so that the inter-vehicle distance in accordance with the inter-vehicle distance Lb during actual travel. A distance coefficient Cb can be set.

(Modification 2)
Instead of the server device 200 executing the route search process, the client terminal 300 may perform the route search process. For example, in this case, the client terminal 300 has map data necessary for performing route search processing in the storage unit 303, and downloads the inter-vehicle distance statistical information Isdb from the server device 200 at a predetermined timing.

FIG. 12 is a flowchart showing a processing procedure executed by the control unit 305 of the client terminal 300 in the modification.

First, the control unit 305 determines whether or not there is a power-off request (step S501). When there is a power-off request (step S501: Yes), the control unit 305 ends the process of the flowchart. On the other hand, when there is no power-off request (step S501: No), the control unit 305 advances the process to step S502.

Next, the control unit 305 determines whether or not a departure place and a destination are set (step S502). At this time, the control unit 305 may accept input regarding route search conditions such as charge priority and distance priority from the input unit 303 in addition to the departure point and destination. When the departure place and the destination are set (step S502: Yes), the control unit 305 starts route search processing (step S503). Specifically, the control unit 305 executes the same processing as Step S304 to Step S307 in FIG. 8 in Step S504 to Step S507. At this time, in step S505, the control unit 305 calculates the inter-vehicle distance coefficient Cb based on the inter-vehicle distance statistical information Isdb downloaded from the server device 200, and weights the link cost calculated in step S504.

If the control unit 305 determines in step S507 that the route search has been completed (step S507: Yes), the control unit 305 displays the route search result (step S508). For example, based on the route search result, the control unit 305 displays the optimum route together with the map on the display unit 307, or displays the required time of the optimum route or / and the passing intermediate point on the display unit 307.

As described above, even when the client terminal 300 performs the route search process, it is possible to search for the optimum route in consideration of the inter-vehicle distance Lb. In this case, the client terminal 300 functions as a “route search device” in the present invention, and the control unit 305 functions as a “route setting unit” and an “inter-vehicle distance information acquisition unit” in the present invention.

(Modification 3)
The configuration of the route search system shown in FIG. 1 is an example, and the configuration to which the present invention can be applied is not limited to this. Instead of this, the route search system may not include the server device 200.

In this case, the client terminal 300 receives the probe information signal S1 from the probe information providing apparatus 100, and generates the inter-vehicle distance statistical information Isdb by executing the flowchart shown in FIG. 7 based on the received probe information signal S1. . Then, the client terminal 300 executes the flowchart of FIG. 12 described in Modification 2 and performs route search processing.

In addition, the client terminal 300 has an inter-vehicle distance sensor instead of receiving the probe information signal S1 from another device, and executes the flowchart shown in FIG. 7 on the basis of the inter-vehicle distance Lb measured by itself. The statistical information Isdb may be generated. In this case, the route search system includes only the client terminal 300.

In this modification, the client terminal 300 functions as a “route search device” in the present invention, and the control unit 305 functions as a “route setting unit” and an “inter-vehicle distance information acquisition unit” in the present invention.

(Modification 4)
In the description of FIG. 8, the control unit 205 weights the link cost calculated in step S304 with the inter-vehicle distance coefficient Cb in step S305. However, the method to which the present invention is applicable is not limited to this. Instead of this, the control unit 205 regards the inter-vehicle distance coefficient Cb as the cost related to the inter-vehicle distance Lb, and calculates the link cost in step S304, like the other costs, multiplied by a predetermined ratio. The distance coefficient Cb may be added to the link cost. Even in this case, the control unit 205 can preferably execute the route search in consideration of the inter-vehicle distance Lb.

(Modification 5)
When the control unit 205 generates the inter-vehicle distance statistical information Isdb in step S205 of FIG. 7, instead of setting the average inter-vehicle distance ALb of the link ID without the inter-vehicle distance Lb to the upper limit value LimLb, another link ID It may be estimated based on the average inter-vehicle distance ALb.

For example, the control unit 205 sets the average inter-vehicle distance ALb of the link ID having no information of the inter-vehicle distance Lb to the same value as the average inter-vehicle distance ALb of the link ID existing in the vicinity of the link. In another example, the control unit 205 calculates the average inter-vehicle distance ALb of the link ID of the road with the link ID that does not have the information of the inter-vehicle distance Lb and the link ID of another road that matches or approximates the traveling condition such as the vehicle speed limit and the information of the road width. Alternatively, the average inter-vehicle distance ALb of the link ID without the information on the inter-vehicle distance Lb may be set.

By doing in this way, the control unit 205 appropriately sets the average inter-vehicle distance ALb for all link IDs even when there is a link ID without information on the inter-vehicle distance Lb, and the inter-vehicle distance Lb. It is possible to suitably execute a route search process considering the above.

(Modification 6)
When displaying the map, the client terminal 300 may determine the display mode of each link based on the inter-vehicle distance statistical information Isdb.

FIG. 13A shows the relationship between the average inter-vehicle distance ALb and the road display color displayed on the map when the display color of the road (link) displayed on the map is changed according to the average inter-vehicle distance ALb. It is a table. In this example, the client terminal 300 colors the road displayed on the map in a darker color as the average inter-vehicle distance ALb is shorter. Thereby, the client terminal 300 can make a user recognize suitably the density of the traveling vehicle in the said road based on the display color of the road displayed on the map.

FIG. 13B is a table showing the relationship between the average inter-vehicle distance ALb and the road display line when the road display line displayed on the map is changed according to the average inter-vehicle distance ALb. In this example, the client terminal 300 shortens the interval between the lines indicating the road displayed on the map as the average inter-vehicle distance ALb is shorter. Thereby, the client terminal 300 can make a user recognize suitably the density of the traveling vehicle in the said road based on the space | interval of the line which shows the road displayed on the map.

In yet another example, the client terminal 300 may display the value of the corresponding average inter-vehicle distance ALb for each road displayed on the map. In these examples, the client terminal 300 receives the inter-vehicle distance statistical information Isdb at regular time intervals, for example.

By doing in this way, the client terminal 300 can make a user grasp the congestion degree of each road based on the inter-vehicle distance Lb.

The present invention can be suitably applied to a device that performs route search.

DESCRIPTION OF SYMBOLS 100 Probe information provision apparatus 102 Inter-vehicle distance sensor 103 GPS receiver 105 Control part 200 Server apparatus 205 Control part 300 Client terminal 303 Input part 305 Control part 307 Display part

Claims

A route setting means for setting a route from the departure point to the arrival point;
Inter-vehicle distance information acquisition means for acquiring inter-vehicle distance information, which is information related to the distance between moving bodies heading in the same direction, in each predetermined section included in the route;
Have
The route search device, wherein the route setting means sets the route based on the inter-vehicle distance information.
The route search device according to claim 1, wherein the inter-vehicle distance information is information related to a distance in a front-rear direction between moving bodies that are traveling in the same lane and are positioned in the front-rear direction.
The route search device according to claim 1 or 2, wherein the inter-vehicle distance information is an average value of a distance between the moving bodies.
The route setting means sets a route having a minimum combined value of passing difficulty indexes in each section of the route from the departure point to the arrival point,
The route search device according to any one of claims 1 to 3, wherein the index is weighted by a coefficient having a negative correlation with a value indicated by the inter-vehicle distance information in a corresponding section.
The inter-vehicle distance information acquiring means generates the inter-vehicle distance information by acquiring information on the distance from the moving body ahead measured by the moving body traveling in each section from the moving body. The route search apparatus as described in any one of Claims 1 thru | or 4.
The route setting means is configured to set the route based on a time zone in which the vehicle is predicted to travel in the section when traveling according to the route and a time zone in which the distance between the moving bodies is measured for the section. The route search device according to any one of claims 1 to 5, wherein the inter-vehicle distance information used for a vehicle is determined.
The route setting means determines the inter-vehicle distance information used for setting the route based on a moving direction or / and a traveling lane of the moving bodies when the distance between the moving bodies is measured. Item 6. The route search device according to any one of Items 1 to 5.
The inter-vehicle distance information acquisition means, when there is a section where the inter-vehicle distance information cannot be acquired, among the sections included in the route, the inter-vehicle distance information of the section is continued to the section where the inter-vehicle distance information cannot be acquired. The route search device according to any one of claims 1 to 7, wherein the route information is estimated based on distance information of a section from which the distance information is acquired.
The route search device according to any one of claims 1 to 8, wherein the inter-vehicle distance information acquisition means sets an upper limit value to a value indicated by the inter-vehicle distance information.
The inter-vehicle distance information acquisition means sets a value of the inter-vehicle distance information of the section to the upper limit value when there is a section from which the inter-vehicle distance information cannot be acquired among the sections included in the route. The route search device according to claim 9.
A control method executed by a route search device,
A route setting process for setting a route from the departure point to the arrival point;
Inter-vehicle distance information acquisition step for acquiring inter-vehicle distance information, which is information relating to the distance between moving bodies heading in the same direction, in each predetermined section included in the route;
Have
The route setting step sets the route based on the inter-vehicle distance information.
A program executed by the route search device,
A route setting means for setting a route from the departure point to the arrival point;
In the predetermined sections included in the route, the route search device functions as an inter-vehicle distance information acquisition unit that acquires inter-vehicle distance information, which is information related to the distance between moving bodies heading in the same direction,
The route setting means sets the route based on the inter-vehicle distance information.