JP2007178219A - Traffic situation detecting method and navigation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a traffic situation detecting method and navigation device for providing guide information of a roundabout intersection. <P>SOLUTION: The navigation device 1 mounted on a vehicle comprises a geographic data storage section 16 storing route data or the like, a communication section 14 for receiving traffic relevant data from the outside, and a CPU 10 that acquires the traffic relevant data of an approach road and an exit road from the roundabout intersection, determines the approach road and exit road where traffic congestion or jam occurs, and updates the traffic congestion cost 11b between the approach road where the traffic congestion or jam occurs and the exit road where the traffic congestion or jam occurs. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a traffic condition detection method and a navigation device.

In recent years, intelligent transport systems have been developed in order to solve traffic problems such as traffic jams and to make vehicles run smoothly. As part of this system, VICS (registered trademark, Vehicle Information and Communication Systems) that distributes traffic-related information, navigation devices that acquire traffic-related information by inter-vehicle communication, etc., advanced information that provides traffic guidance based on pre-stored data A navigation device has been proposed. The navigation device provides guidance regarding a road where a traffic jam has occurred or a road where a traffic jam is likely to occur, or provides a route for avoiding the traffic jam.

As such an apparatus, Patent Document 1 describes an apparatus that determines the presence or absence of an intersection signal based on road data stored in advance and predicts the waiting time of a traffic light. Furthermore, this apparatus calculates a required time to the destination including the waiting time, and guides a route with a short required time.
JP 2001-165684 A

  However, the above-described navigation device can predict traffic jams due to waiting for traffic lights, but cannot predict traffic jams due to other factors. In addition, a navigation device that acquires traffic-related information by communication can acquire information on traffic jams over long distances on major roads such as expressways and national roads, but traffic jams in roundabouts (hereinafter referred to as roundabouts) Traffic related information on congestion cannot be obtained. For this reason, a route may be searched without taking into consideration the traffic jam in the rotary, and a route with a long required time may be guided. In addition, there is a problem that traffic information cannot be provided even if there is traffic in the rotary.

  The present invention has been made in view of the above problems, and an object thereof is to provide a traffic condition detection method and a navigation device for providing rotary guidance information.

  In order to solve the above-mentioned problems, the invention according to claim 1 is characterized in that traffic congestion or congestion at a roundabout is achieved by using road data storage means for storing road data and communication means for receiving traffic-related data from the outside. A traffic condition detection method for detecting a traffic situation, wherein traffic related data of an approach road and an exit road for a roundabout is acquired by the communication means, and an entrance road and an exit road where congestion or congestion occurs are detected. At the same time, based on the detected approach road and exit road, the gist is to determine the round road in the roundabout as a congested road or a congested road.

  The invention according to claim 2 is the traffic condition detection method according to claim 1, wherein the circuit road between the approach road and the exit road where congestion or congestion occurs is a congestion road or a congestion road. The gist is to judge that there is.

According to a third aspect of the present invention, in a navigation apparatus mounted on a vehicle, road data storage means for storing road data, communication means for receiving traffic-related data from the outside, an approach path and an exit path for a roundabout Obtaining the traffic-related data, and detecting the approach road and the exit road where congestion or congestion occurs, and based on the detected approach road and the exit road, the round road in the roundabout The gist is provided with a cost updating means for updating the cost.

  According to a fourth aspect of the present invention, in the navigation device according to the third aspect, the cost updating means updates the cost of the circuit road between the approaching road and the exiting road where congestion or congestion occurs. The gist is to do.

  According to a fifth aspect of the present invention, in the navigation device according to the fourth aspect, the cost update means is the most out of the approach road where congestion or congestion occurs among the exit paths where congestion or congestion occurs. The gist is to detect a distant exit road and update the cost of the circuit road between the exit road and the approach road.

  The invention according to claim 6 is the navigation device according to any one of claims 3 to 5, further comprising search means for searching for a guide route from the current position to the destination, wherein the search means is updated. The gist is to re-search the guide route based on the cost in the roundabout.

  According to a seventh aspect of the present invention, in the navigation device according to the sixth aspect, when the vehicle approaches the roundabout, the search means determines a guide route based on the updated cost in the roundabout. The gist is to search again.

  The invention according to claim 8 is the navigation device according to any one of claims 3 to 7, further comprising guidance output control means for outputting guidance information regarding traffic jam or congestion in the roundabout. And

  According to the first aspect of the present invention, the approach road and the exit road where the traffic congestion has occurred are detected, and the round road between the approach road and the exit road in the roundabout is a congested road or a congested road. Judge that there is. For this reason, even when the traffic related data in the roundabout is not distributed, the traffic situation in the roundabout can be predicted.

  According to the second aspect of the present invention, it is determined that the circuit road between the approach road and the exit road where traffic congestion or congestion occurs is a traffic congestion road or a congestion road. For this reason, it is possible to detect a round road where there is a possibility of traffic congestion or congestion without leakage.

  According to the invention described in claim 3, when the traffic congestion or congestion of the approach road and the exit road of the roundabout is detected, and the approach road and the exit road that are congested or congested are detected, the detected approach road is detected. And the cost of the round road is updated based on the exit route. For this reason, the information regarding the traffic situation in the roundabout can be used, for example, when the data about the traffic situation in the roundabout cannot be acquired, and guidance according to the cost in the roundabout can be performed.

  According to the invention described in claim 4, the cost of the round road between the approach road and the exit road that are congested or congested is updated. For this reason, the cost of the road around which there is a possibility of congestion or congestion can be increased without omission.

  According to the fifth aspect of the present invention, the farthest exit route is detected from the traffic jam or the congested approach route, and the cost between the exit route and the approach route is updated. For this reason, since the cost of the road around which congestion or congestion is predicted is updated, it is possible to detect the road around the road without congestion.

According to the sixth aspect of the present invention, since the guide route is re-searched based on the cost in the roundabout, congestion or congestion in the roundabout can be avoided.
According to the seventh aspect of the present invention, since the guidance route that has been searched once is re-searched based on the updated cost, the route that avoids the round road where traffic congestion or congestion occurs in the roundabout is guided. Can do.

  According to the eighth aspect of the invention, since the guide information regarding the traffic jam or congestion in the roundabout is output, the driver can acquire information in the roundabout.

Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS.
As shown in FIG. 1, the navigation apparatus 1 mounted on the vehicle includes a CPU 10, RAM 11, ROM 12, a GPS receiving unit 13, and a communication unit 14 as a communication unit as situation detection means, cost update means and search means. Yes. The CPU 10 inputs a position detection signal indicating coordinates such as latitude and longitude received by the GPS receiver 13 from a GPS (Global Positioning System) satellite. In addition, vehicle speed pulses and angular velocities are respectively input from the vehicle speed sensor 30 and the gyro sensor 31 provided in the vehicle via the sensor side I / F unit 15. Based on these signals, the CPU 10 detects the vehicle position by combining radio navigation and autonomous navigation.

The communication unit 14 receives traffic-related data T from a beacon or a base station constituting VICS (registered trademark, Vehicle Information and Communication Systems). The traffic-related data T is updated every few minutes, and the surrounding traffic-related data T is transmitted from radio wave beacons or optical beacons, etc., and each prefectural unit is transmitted from the base station that transmits FM multiplex broadcasting. Traffic related data T is transmitted. This traffic-related data T includes a VICS link of a road on which a traffic jam or congestion has occurred and traffic jam data indicating the traffic jam or congestion. In the present embodiment, the traffic jam refers to a state in which the average speed of each automobile has decreased to a certain speed (for example, 20 km to 30 km per hour), or a state in which a row of low speed cars has reached a certain distance or more. The congestion is a state in which the degree of congestion (congestion level) is lower than the congestion.

  The navigation apparatus 1 also includes a geographic data storage unit 16 as road data storage means and an image processor 20 as guidance output control means. The geographic data storage unit 16 is an external storage medium such as a built-in hard disk or optical disk. In the geographic data storage unit 16, each route network data (hereinafter referred to as route data 17) as road data for searching for a route to the destination, and a map as guidance information on a display 25 as output means. Each map drawing data 18 for outputting the screen 25a is stored. As shown in FIG. 2, the route data 17 is data for each region that divides the whole country into areas, and includes a header 17a, node data 17b, link data 17c, link cost 17d, coordinate data 17e, road attribute data 17f. , Version 17g. The header 17 a has data for managing each path data 17. The node data 17b includes identification data such as numbers of nodes indicating intersections, road end points, and the like, identification data of adjacent nodes, and the like. The link data 17c includes a link ID, each link ID indicating a connection node, data indicating traffic regulation, and the like. The link cost 17d is a data group composed of a link length, an average travel time, and the like. The coordinate data 17e indicates the absolute coordinates of each node. The road attribute data 17f is data indicating a traffic direction, an expressway, a roundabout (hereinafter referred to as a roundabout), and the like. The version 17g indicates the version of the route data 17.

The CPU 10 uses this route data 17 to search for a guide route that connects the destination and the current vehicle position. At this time, using the link length, average travel time, etc. of the link cost 17d,
A plurality of routes are searched for, such as a guide route with the shortest distance, a guide route with the shortest travel time, and a guide route with reduced expenses. Then, once searching for each guide route, the CPU 10 stores the search history data 11 a indicating the node / link representing the route data in the RAM 11.

  Further, the map drawing data 18 is stored for each area obtained by dividing the map of the whole country, and is divided for each layer from a wide area map to a narrow area map. As shown in FIG. 3, each map drawing data 18 includes a header 18a, road drawing data 18b, background data 18c, and version 18d. The header 18a indicates the hierarchy, area, and the like of the map drawing data 18, and is management purpose data. The road drawing data 18b is data indicating the shape of the road displayed on the map and the road surface condition. The background data 18c is drawing data for drawing roads, urban areas, rivers, and the like.

  Based on the CPU 10, the image processor 20 of the navigation device 1 reads map drawing data 18 corresponding to a predetermined distance from the vehicle position from the geographic data storage unit 16. Then, drawing data for drawing a road having a shape based on the road drawing data 18b and a city area based on the background data 18c is generated and temporarily stored in the built-in memory. And the video signal based on drawing data is output to the display 25 with the index data which shows the own vehicle position. As a result, as shown in FIG. 1, a map screen 25 a on which a current position index 25 b indicating the vehicle position is superimposed is displayed on the display 25.

  In addition, the navigation device 1 includes an audio processor 19 as shown in FIG. The audio processor 19 reads an audio file from an audio file database (not shown) under the control of the CPU 10 and outputs an audio signal to the speaker 26 serving as output means. Thereby, a guidance voice or the like for guiding the route is output.

  The navigation device 1 includes an external input I / F unit 21. The external input I / F unit 21 outputs an electrical signal corresponding to the input operation to the CPU 10 when an operation switch 27 or the like provided adjacent to the display 25 of the navigation device 1 is operated. The display 25 is a touch panel. When the touch panel is input, the external input I / F unit 21 outputs an electrical signal corresponding to the input operation to the CPU 10.

  Next, the processing procedure of this embodiment is demonstrated according to FIG.4 and FIG.5. First, after the navigation apparatus 1 is activated, the CPU 10 waits for the start of route guidance or guidance around the vehicle position (step S1-1). If it is determined that guidance has started (YES in step S1-1), it is determined whether or not the current mode is a mode for searching and guiding a route to the destination (step S1-2).

  If CPU 10 determines that it has searched for a route to the destination based on route data 17 (YES in step S1-2), there is a rotary within a predetermined distance (for example, 5 km) from the current vehicle position on the route. (Step S1-3). At this time, the CPU 10 determines the presence or absence of a rotary on the route based on the road attribute data 17f in the route data 17 or the link data 17c.

  If it is determined that there is no rotary on the route within the predetermined distance (NO in step S1-3), the process proceeds to step S1-8 to determine whether or not to end the guidance. At this time, the CPU 10 determines whether or not the guidance end input operation has been performed by the operation switch 27 or the like or the destination has been reached. If it is determined not to end the guidance (NO in step S1-8), the process returns to step S1-1.

  If it is determined that there is a roundabout on the route within a predetermined distance (YES in step S1-3), a congestion cost setting process is performed for the road connected to the detected roundabout (step S1-4).

This congestion cost setting process will be described with reference to FIG.
First, the CPU 10 initializes the reference road number n stored in the RAM 11 to “1” (step S2-1). The reference road number n is a number given to the connecting roads R1 to R4 that can enter or leave the rotary 100 when the rotary 100 as shown in FIG. 6 is detected in step S1-3. In the rotary 100, the vehicle C goes around in a certain direction (clockwise). Moreover, since the vehicle C in the rotary 100 has priority over the vehicle C in the connection roads R1 to R4, when the vehicle C in the connection roads R1 to R4 enters the rotary 100, the inside of the rotary 100 is congested or congested. If you do, you must wait in the approach path. In FIG. 6, four connecting roads R <b> 1 to R <b> 4 are connected to the rotary 100 in the rotary 100, but other numbers such as six may be used.

  Next, the CPU 10 sets a reference connection road Rn (step S2-2). At first, since the reference road number n is “1”, the connection road R1 on which the vehicle C on which the navigation device 1 is mounted travels is set.

  Further, the CPU 10 determines whether or not the approach road R1a of the connection road R1 is congested (or congested) (step S2-3). At this time, the CPU 10 determines whether the approach road R1a of the connection road R1 is congested or congested based on the VICS link, traffic jam data, and the like in the traffic related data T acquired by the communication unit 14.

  If it is determined that the approach road R1a of the connecting road R1 is not congested or congested (NO in step S2-3), "1" is added to the reference road number n and updated (step S2-4). Further, the CPU 10 sets the number of all roads connected to the rotary 100 based on the route data 17 as the number of connected roads Na. For example, in the rotary 100 illustrated in FIG. 6, the number of connected roads Na is “4”.

  Then, the CPU 10 determines whether or not the reference road number n updated in step S2-4 is larger than the number of connected roads Na (step S2-5). Here, since the reference road number n is “2”, it is determined that the number of connected roads Na is “4” or less, and the process returns to step S2-2. In step S2-2, since the reference road number n is “2”, the connection road R2 is set as the reference road. Then, the above-described processing is repeated until a traffic jam or a congested approach path is detected among the approach paths R1a to R4a of the connection roads R1 to R4. When it is determined that all the approach roads R1a to R4a are not congested or congested, the reference road number n is updated to “5” in step S2-4. In step S2-5, the CPU 10 determines that the reference road number n is larger than the number of connected roads Na “4”, and proceeds to step S1-5 (see FIG. 4).

  On the other hand, if it is determined that the approach road R1a of the connection road R1 is congested or congested (YES in step S2-3), the congested or congested condition of the exit paths R1b to R4b is acquired based on the congested data. (Step S2-6). Further, it is determined whether there is an exit path that is congested (or congested) based on the congested or congested condition (step S2-7). If it is determined that there is no traffic jam or a congested exit route (NO in step S2-7), the process proceeds to step S1-5 (see FIG. 4).

If it is determined that there is a traffic jam or a congested exit route (YES in step S2-7), the traffic jam exit route Jm farthest from the reference connection road R1 is detected among the exit routes (step S2-8). For example, in step S2-6, of the connecting roads R2 to R4, only the exit road R2b of the connection road R2, only the exit road R3b of the connection road R3, or only the exit road R4b of the connection road R4 is congested or congested. In this case, the exit routes R2b, R3b, and R4b are designated as traffic exit routes J2, J3, and J4, respectively. Further, when the exit roads R2b and R3b of the two connection roads R2 and R3 are both congested or congested, the exit road R3b of the connection road R3 farther away from the connection road R1 is referred to as the traffic jam exit path J3. To do. When all the three exit routes R2b to R4b are congested or congested, the exit route R4b farthest on the route is set as the traffic exit route J4.

  Next, the CPU 10 increases (cost increases) the traffic cost 11b (see FIG. 1) for the link Ln from the reference connection road R1 to the traffic exit route Jm (step S2-9). If the exit road R2b of the connection road R2 is set as the traffic jam exit road J2 in step S2-7, it is assumed that the entrance road R1a of the connection road R1 to the exit road R2b of the connection road R2 is congested or congested. The Therefore, the traffic congestion cost 11b of the link L1 from the connection road R1 to the connection road R2 (congestion exit path J2) is updated to a value indicating congestion or a value indicating congestion on the circumference road in the rotary 100 shown in FIG. . Then, the congestion cost 11b and the link L1 are associated with each other and stored in the RAM 11.

  When the exit road R3b of the connection road R3 is a traffic jam exit road J3, it is assumed that the route is congested or congested from the approach road R1a of the connection road R1 to the exit road R3b of the connection road R3. Therefore, the congestion cost 11b of the link L1 and the link L2 from the connection road R1 to the connection road R3 (congestion exit path J3) is updated to a value indicating congestion or a value indicating congestion. That is, the circuit road in the rotary 100 from the approach road R1a where the traffic jam or congestion occurs to the farthest traffic jam exit road Jm among the exit road where the traffic jam or congestion occurs is highly likely to be a traffic jam road or a congestion road. . For this reason, the traffic congestion cost 11b of the link Ln corresponding to the circuit road is increased, and the time required for passing the circuit road is set longer.

  Then, when the cost of the traffic jam 11b is increased, the CPU 10 determines whether or not the setting of the traffic jam cost 11b is finished for the road around the rotary 100 related to the guidance route (step S2-10). Here, it is determined that the traffic congestion cost 11b for one round of the rotary 100 is not calculated. Then, the value of the congestion road number m is input to the reference road number n stored in the RAM 11 (that is, n = m), the reference road number n is updated (step S2-11), and the process returns to step S2-2. .

  Returning to step S2-2, a reference connection road Rn is set based on the updated reference road number n. If the reference road number n is “3”, for example, the newly established reference road Rn is set as the connection road R3. Further, the CPU 10 determines whether or not the approach road R3a of the connecting road R3 is congested or congested (step S2-3), and when it is congested or congested (YES in step S2-3), the traffic Based on the related data T, the traffic congestion or congestion status of all exit routes is acquired (step S2-6).

  Furthermore, the CPU 10 determines whether or not there is a congested exit path (step S2-7), and when it is determined that there is a congested or congested exit path (YES in step S2-7). The exit path (for example, exit path R2b) farthest from the connection road R3 that is the current reference is defined as a traffic jam exit path Jm.

Then, the CPU 10 increases the traffic congestion cost 11b for the links L3, L4, and L1 from the reference connection road R3 to the traffic congestion exit road J2 (connection road R2) (step S2-9). The traffic congestion cost 11b once increased in cost does not increase any more. If there is an overlap of the congestion cost 11b that increases the cost, the CPU 10 determines that the congestion cost 11b for one round has been calculated, determines that the calculation is to be ended (YES in step S2-10), and step S1-5. Proceed to

  In step S1-5 shown in FIG. 4, the CPU 10 re-searches the guidance route to the destination based on the congestion cost 11b. For example, the guidance route is re-searched by adding the congestion cost 11b to the link cost 17d of the route data 17 in consideration of the congestion cost 11b. Then, it is determined whether or not there is a change between the previously searched route based on the search history data 11a stored in the RAM 11 and the newly searched guide route (step S1-6). If it is determined that there is no change (NO in step S1-6), the process proceeds to step S1-8 to determine whether or not to end the guidance. If it is determined not to end the guidance (NO in step S1-8), the process returns to step S1-1.

  If it is determined that there is a change (YES in step S1-6), route change guidance is provided (step S1-7). Specifically, the CPU 10 controls the image processor 20 to read out the map drawing data 18 indicating the newly searched route from the geographic data storage unit 16. The map drawing data 18, index data indicating the current position of the vehicle C, route index data indicating the route, and guidance display data are output to the display 25. As a result, the map screen 25a shown in FIG. On the map screen 25a, a current position index 25b indicating the vehicle position is superimposed on the map around the vehicle position and displayed. Further, a route index 25c indicating a route to avoid the rotary 100 and a change notification display 25d as guidance information for notifying the route change are displayed. Further, the CPU 10 controls the voice processor 19 to output from the speaker 26 a change notification voice 26a as guide information for notifying the change of the guide route. When the map screen 25a, the change notification sound 26a, etc. are output, the CPU 10 determines whether or not the guidance is finished (step S1-8). If the guidance is not finished (NO in step S1-8), step S1-1 is performed. Return to.

  On the other hand, as shown in FIG. 4, if it is determined in step S1-2 that the navigation device 1 does not search for a route and is a mode for guiding around the current position of the vehicle C (NO in step S1-2), the CPU 10 Determines whether or not there is a rotary 100 within a predetermined distance range from the vehicle C based on the route data 17 (step S1-9). This predetermined distance is a distance range centered on the vehicle C and is, for example, a range of 5 km to 10 km. If it is determined that there is a rotary 100 subject to the traffic jam cost setting process (YES in step S1-9), the link Ln in the rotary 100 is linked to the link Ln based on the traffic-related data T as in the traffic jam cost setting process described above. The congestion cost 11b is set (step S1-10).

  When the congestion cost setting process is completed, the CPU 10 determines whether or not the inside of the rotary 100 is congested or congested based on the congestion cost 11b (step S1-11). If it is determined that there is no traffic jam or congestion in the rotary 100 based on the traffic jam cost 11b of the rotary 100 (NO in step S1-11), the process proceeds to step S1-8.

If it is determined that the inside of the rotary 100 is congested or congested (YES in step S1-11), the CPU 10 notifies the congested or congested (step S1-12). For example, the CPU 10 displays a map screen 25a as shown in FIG. 8, and displays a traffic jam indicator 25e indicating traffic jam at a position where traffic jam or congestion occurs. Further, a traffic jam guidance display 25f as guidance information such as “the front rotary is crowded” is superimposed on the map screen 25a. Further, the CPU 10 controls the voice processor 19 to output a guidance voice 26 b as guidance information such as “the front rotary is crowded” from the speaker 26. Thus, when traffic jam or congestion is notified, it progresses to step S1-8 and it is judged whether guidance was complete | finished. When arrival at the destination or input operation of the operation switch 27 or the like is performed, it is determined that the guidance is finished (YES in step S1-8), and the process is finished.

According to the above embodiment, the following effects can be obtained.
(1) In the above embodiment, the navigation device 1 receives the traffic-related data T related to the approach road and the exit path with respect to the rotary 100 by the communication unit 14 and determines the approach path or the exit path where the traffic jam or congestion occurs. It was made to detect. When the traffic cost 11b between the approach road where the traffic jam or congestion occurs and the exit road where the traffic jam or congestion occurs is increased and the vehicle passes between the entrance road and the exit road. The cost (time) is set to be large. For this reason, the traffic cost 11b in the rotary 100 can be set even when data relating to the traffic situation in the rotary 100 cannot be acquired. Therefore, route guidance according to the congestion cost 11b can be performed.

  (2) In the embodiment described above, the exit path farthest from the approach path to the rotary 100 on which the navigation device 1 is running is set as the congestion exit path Jm among the exit paths in which congestion or congestion is detected. did. Then, the traffic congestion cost 11b for the link Ln between the reference connecting road Rn and the traffic exit route Jm is increased. For this reason, it is possible to increase the traffic cost 11b for the round road in the rotary 100 where the traffic jam or congestion occurs, or the round road where the possibility of the occurrence of traffic jam or congestion is high.

  (3) In the above embodiment, when the navigation device 1 provides route guidance to the destination, the route to the destination is re-searched in consideration of the newly set congestion cost 11b. . Further, when the guidance route is changed by re-searching, the change is notified on the map screen 25a and the change notification voice 26a. For this reason, when a portion related to the guide route in the rotary 100 is congested or congested, the driver can avoid the congested or congested by following the changed guide route.

  (4) In the above embodiment, when the navigation device 1 does not perform a route search and simply guides around the vehicle position, all the connecting roads that detect the rotary 100 in front of the vehicle C and are connected to the rotary 100 are detected. R1 to R4 are targeted for the traffic jam cost setting process. And when traffic jam or congestion has arisen in the rotary 100, the map screen 25a and the guidance audio | voice 26b which show the traffic jam or congestion situation in the rotary 100 were output to the map screen 25a. For this reason, since the traffic jam or the congestion situation of the whole area | region in the rotary 100 can be grasped | ascertained, a traffic jam or congestion can be avoided smoothly.

In addition, you may change this embodiment as follows.
-Although the navigation apparatus 1 of the said embodiment uses VICS, another communication system can be used. For example, when the navigation apparatus 1 is mounted on a vehicle C traveling in Europe, RDS / TMC (Radio Data System / Traffic Message Channel) using FM multiplex broadcasting can be used.

In the above embodiment, the route data 17 and the map drawing data 18 have the data structures shown in FIGS. 2 and 3, but other data structures may be used.
In the above embodiment, even when the navigation device 1 is not searching for a route, when a new destination is input by the user, the route is searched using the congestion cost 11b stored in the RAM 11. You may do it.

In the above embodiment, in step S2-3, the traffic congestion or congestion of the reference approach roads R1a to R4a is determined. If the traffic congestion or congestion is present (YES in step S2-3), the congestion cost is set. I went to. In addition to this, step S2-3 may be omitted, and traffic jams or congestion conditions may be sequentially determined for the exit routes R1b to R4b of the reference connecting roads R1 to R4. For example, when the exit route R2b is congested, the congestion cost 11b may be increased for the link L1 downstream of the exit route R2b. Then, the traffic jam or congestion state of the exit route R3b is determined. If the traffic jam or the traffic jam is present, the traffic jam cost 11b for the link L2 is increased. Further, for the exit routes R4b and R1b, the traffic congestion or the congestion state is determined, and it is determined whether or not the traffic congestion cost 11b for the links L3 and L4 can be increased.

  -In the said embodiment, you may make it deliver the calculated traffic congestion cost 11b to another vehicle by vehicle-to-vehicle communication. Or you may make it transmit to another vehicle by transmitting to a base station etc. and road-to-vehicle communication.

The block diagram of the navigation apparatus of this embodiment. Explanatory drawing of route data. Explanatory drawing of map drawing data. Explanatory drawing of the process sequence of this embodiment. Explanatory drawing of the process sequence of this embodiment. Explanatory drawing of a rotary. Explanatory diagram of traffic guidance screen and audio. Explanatory diagram of traffic guidance screen and audio.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Navigation apparatus, 10 ... CPU as situation detection means, cost update means, and search means, 11b ... Congestion cost as cost, 14 ... Communication part as communication means, 16 ... Geographic data storage part as road data storage means 17 ... Route data as road data, 20 ... Image processor as guidance output control means, 25a ... Map screen as guidance information, 25d ... Change notification display as guidance information, 25f ... Congestion guidance display as guidance information, 26a ... change notification voice as guidance information, 100 ... roundabout as a roundabout, C ... vehicle, R1a to R4a ... approach road, R1b to R4b ... exit road, T ... traffic related data.

Claims (8)

A traffic condition detection method for detecting traffic congestion or congestion at a roundabout using road data storage means for storing road data and communication means for receiving traffic-related data from the outside,
Traffic related data of the approach and exit routes for the roundabout is acquired by the communication means, and the approach and exit routes where congestion or congestion occurs are detected, and based on the detected approach and exit routes, A traffic condition detection method, wherein a round road in the roundabout is determined to be a congested road or a congested road. In the traffic condition detection method according to claim 1,
A traffic condition detection method, characterized in that a circuit road between the approach road and the exit road where congestion or congestion occurs is determined to be a congestion road or a congestion road. In a navigation device mounted on a vehicle,
Road data storage means for storing road data;
A communication means for receiving traffic-related data from the outside;
A situation detecting means for acquiring the traffic-related data of the approach road and the exit road with respect to the roundabout, and detecting the approach road and the exit road where congestion or congestion occurs;
A navigation apparatus comprising: cost updating means for updating the cost of a round road in the roundabout based on the detected approach road and exit road. The navigation device according to claim 3,
The cost update means includes
A navigation device that updates a cost of a circuit road between the approach road and the exit road where traffic congestion or congestion occurs. The navigation device according to claim 4, wherein
The cost update means includes
Detects the exit road farthest from the approach road where the congestion or congestion occurs among the exit roads where the congestion or congestion occurs, and updates the cost of the circuit road between the exit road and the approach road A navigation device characterized by that. The navigation device according to any one of claims 3 to 5,
A search means for searching a guide route from the current position to the destination is provided.
The navigation device according to claim 1, wherein the search means searches for a guide route based on the updated cost in the roundabout. The navigation device according to claim 6, wherein
The navigation device according to claim 1, wherein when the vehicle approaches the roundabout, the search means re-searches the guide route based on the updated cost in the roundabout. The navigation device according to any one of claims 3 to 7,
A navigation apparatus further comprising guidance output control means for outputting guidance information regarding traffic jam or congestion in a roundabout.

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