JP3443246B2 - Car navigation system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-vehicle navigation device that searches for an optimum guide route to a destination and guides a user along the guide route, and particularly, it transmits from the outside via radio waves or light. Received the traffic information,
The present invention relates to a vehicle-mounted navigation device that searches for a guidance route to a destination using this traffic information.

[0002]

2. Description of the Related Art A vehicle-mounted navigation device includes a map data storage device such as a CD-ROM or an IC card storing map data, a display device, a gyro, and a GPS.
(Global Positioning System) and a vehicle movement detection device such as a vehicle speed sensor that detects the current position and current azimuth of the vehicle, and reads the map data including the current position of the vehicle from the map data storage device, and based on the map data. Draws a map image around the vehicle position on the display device, displays the vehicle position mark (location) on the display screen, and scrolls the map image according to the movement of the vehicle, or displays the map image. By fixing it on the screen and moving the vehicle position mark, it is possible to see at a glance where the vehicle is currently traveling.

Further, a vehicle-mounted navigation device is usually equipped with a route guidance function that allows a driver to easily travel to a desired destination without making a mistake on the road. According to this route guidance function, the route with the lowest cost connecting the starting point to the destination is automatically searched by using the map data by performing a simulation calculation such as horizontal search method or Dijkstra method, and the searched route is guided. It is stored as a route, and while driving, the guide route is drawn in a different color from the other roads on the map image and displayed thickly on the screen, or at a certain distance to the intersection where the vehicle should change the route on the guide route. When approaching inside, the driver can easily understand the optimum route to the destination by drawing an arrow indicating the route at the intersection where the route should be changed on the map image and displaying it on the screen. I have to.

The cost is a value obtained by multiplying a road width, a road type (whether it is a general road or a highway, etc.), a constant according to a right turn, a left turn, etc., or a predicted travel time of a vehicle based on the distance. , Is a numerical representation of the degree of suitability as a guide route. Even if there are two routes with the same distance, the cost will be different depending on whether or not the user uses the toll road, whether the distance is prioritized or the time is prioritized.

A map stored in a map data storage device such as a CD-ROM has a longitude width of an appropriate size according to the scale level such as 1/12500, 1/25000, 1/50000 and 1/100000. It is divided into latitude widths, and roads and the like are stored as a coordinate set of vertices (nodes) represented by longitude and latitude. A road is formed by connecting two or more nodes, and a part connecting two nodes is called a link. Further, the map data includes (1) a road layer including a road list, a node table, an intersection configuration node list, and the like, (2) a background layer for displaying roads, buildings, facilities, parks, rivers, etc. on the map screen, (3) Administrative division names such as municipalities,
It is composed of characters such as road names, intersection names and building names, and a character / symbol layer for displaying map symbols.

[0006] In recent years, traffic information (congestion information, accident information, traffic closure information, traffic regulation information, etc.) sent from outside the vehicle has been received, and the traffic information is used to identify the roads on which a traffic jam or accident has occurred. Navigation devices have also been developed that allow users to search for guidance routes while avoiding closed roads. According to this type of navigation device, it is possible to reach the destination in a short time without passing through a road in which a traffic jam or an accident has occurred.

[0007]

However, even if the user travels along the guide route searched based on the traffic information, when the vehicle arrives at a point where there was no traffic congestion at the time when the traffic information was received, the traffic congestion will occur. It has occurred, and since it has traveled along the guide route, it may take some time instead. For example, as shown in FIG. 7, there is no traffic congestion at the B point when passing through the A point on the expressway, and the vehicle travels along the guide route (thick line in the figure) searched using the traffic information at the A point. However, when the vehicle reached the point B, there was congestion at the confluence surrounded by the broken line in the figure, and as a result, it was possible to reach the destination D in a shorter time by traveling on the route indicated by C in the figure. There is a thing.

In view of the above, an object of the present invention is to provide a vehicle-mounted navigation device that can more accurately calculate the time to reach a destination during route search and searches for a guide route that can reach the destination in the shortest time. Is to provide.

[0009]

[Means for Solving the Problem] The above-mentioned problem is solved by the traffic information receiving means for receiving the traffic information in a vehicle-mounted navigation device for searching a guide route to a destination based on traffic information sent from the outside. And past data storage means for storing past traffic information separately for each time, and the past traffic information stored in the past data storage means and the latest traffic information acquired via the traffic information receiving means. And a guide route search means for searching for the guide route by utilizing the vehicle navigation device.

In the present invention, the past data storage means stores past traffic information. Therefore, based on the past traffic information, it is possible to know the road on which the vehicle will pass from now on and the condition of the road at the time when the vehicle passes. it can. For example, it is assumed that the traffic information for every 10 minutes is recorded for one week in the past data storage means. In general, road congestion is greatly related to the day of the week and the time of day. Therefore, by using the traffic information of the same day in the past stored in the past data storage means, the traffic congestion and the traffic congestion that will occur To some extent, you can know the congestion that will be resolved.

According to the present invention, the past traffic information is stored in the past data storage means in this way, and the cost of the road at the time when the vehicle passes is calculated using the past traffic information. It will be possible to calculate the cost taking into account road conditions such as traffic congestion and the traffic that will be solved in the future. As a result, the time required to reach the destination can be grasped more accurately, and the guide route that can reach the destination in the shortest time can be obtained.

The guide route in a range relatively close to the departure place (for example, a range reachable within a preset fixed time) uses the latest traffic information acquired via the traffic information receiving means. It is preferable. On the other hand, when the traveling time from the departure place to the destination is long, the road condition acquired from the traffic information receiving means is likely to change on the way, so the past traffic information stored in the past data storage means is used. Preferably. Therefore, the time required to reach the destination is calculated by using the latest traffic information acquired through the traffic information receiving means, and if the time required exceeds a certain time, a guide route that travels within the certain time Is searched based on the latest traffic information, and a guidance route for the time exceeding the predetermined time is searched using the past traffic information recorded in the past data storage means.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram showing the configuration of a vehicle-mounted navigation device according to an embodiment of the present invention. Reference numeral 1 is a navigation device body composed of a microcomputer. Reference numeral 2 denotes a liquid crystal monitor (display device), and the navigation device main body 1 displays a map near the current position of the vehicle on the liquid crystal monitor 2, a guide route from a departure place to a destination, a vehicle position mark, and others. Display the guidance information of.

3 is a CD-ROM storing map data composed of road layers, background layers, character / symbol layers, etc., according to scale, and 4 is satellite navigation information such as the current position of the vehicle, the vehicle direction and the vehicle speed. It is a GPS receiver for detecting. 5 is a beacon receiver, and this beacon receiver 5
Receives an optical beacon or a radio beacon output from a transmitter provided along the road. An FM multiplex reception unit 6 receives traffic information multiplexed in FM broadcasting. Optical beacons and radio beacons are used to supply traffic information in a narrow area, but relatively detailed traffic information is supplied. On the other hand, the communication range of FM multiplex broadcasting is extremely wide (for example, the entire Kanto region), but the density of information is relatively low.

Reference numeral 7 denotes a gyro for detecting the rotation angle of the vehicle,
8 is a vehicle speed pulse detection unit that detects a vehicle speed pulse generated as the vehicle moves, 9 is a traffic information data memory that stores traffic information obtained via the beacon receiver 5 or the FM multiplex reception unit 6, Past traffic information is stored in the traffic information data memory 9. The navigation device body 1 detects the current position, azimuth, speed, etc. of the vehicle with high accuracy based on the information obtained from the GPS receiver 4, the gyro 7, and the vehicle speed pulse detector 8. In addition, the navigation device body 1 is based on the map data stored in the CD-ROM 3 and the traffic information acquired via the beacon receiver 5 or the FM multiplex reception unit 6 from the departure place to the destination designated by the user. The route with the lowest cost is searched as a guide route, and a map image near the current position of the vehicle is displayed on the monitor 2 using the map data stored in the CD-ROM 3, and the vehicle position mark and the guide route are displayed. Is displayed according to the map image, and further various kinds of guidance information are provided to the user according to the movement of the vehicle.

FIG. 2 is a schematic diagram showing a link. The link corresponds to a road between two adjacent intersections, and the road is represented as a set of a plurality of continuous links. Also,
As shown in FIG. 2, each link is provided with an individual link number (for example, L1 to L8). The traffic information sent via an optical beacon, a radio wave beacon, or FM multiplex broadcasting includes a time required for each link from the start point to the end point (hereinafter referred to as travel time).

FIG. 3 is a diagram schematically showing a data storage area of the traffic information data memory 9. The data storage area of the traffic information data memory 9 is divided for each day of the week from Sunday to Saturday, and the data storage area for each day of the week is a data storage area for every 10 minutes from 0:00 to 23:50. I know. The data storage area for each hour is divided into two unit data storage areas for each link, one for an up route and one for a down route, and each unit data storage area includes the past four weeks of link travel time. The average value can be stored. A value (weight) indicating the average travel time of weeks is also recorded in the memory 9 at the same time. For example, when the travel time of the first week to the fourth week has the values shown in Table 1 below, the average travel time is calculated as shown in the table and updated every week.

[0018]

[Table 1]

Thus, as shown in FIG. 3, in the memory 9, the average value of the link travel times is a kind of table (hereinafter,
This table is stored as a "link average travel time data table"). The operation of the vehicle-mounted navigation device according to this embodiment will be described below. The car navigation device of the present embodiment guides as follows depending on whether or not it is possible to receive traffic information from the outside, and whether or not the traveling time from the departure place to the destination is a preset time or less. Search for a route.

(1) When the traffic information can be received and the traveling time from the departure place to the destination is shorter than a preset fixed time (for example, within 1 hour), the navigation device uses the traffic information data. The shortest time route to the destination is searched using the latest traffic information data input via the optical beacon, the radio beacon or FM multiplex broadcasting without using the link average travel time data table in the memory 9. . In other words, if the travel time is within one hour, the degree of traffic congestion will not change significantly, so the guide route is searched using the latest traffic information.

(2) When the traffic information can be received and the traveling time from the departure place to the destination is longer than the fixed time, the navigation device arrives from the departure place to the destination at the fixed time. The guide route to the point to be visited is searched using the latest traffic information data, and subsequent guide routes are searched using the link average travel time data table in the memory 9.

(3) When the traffic information cannot be received, that is, where the beacon is not installed or the FM broadcast cannot be received, the guide route is searched using the link average travel time data table in the memory 9. To do.
Of the above, regarding the guide route search method according to (2),
This will be described below. FIG. 4 is a diagram showing a road between the departure point ST and the destination DS, and FIG. 5 is a diagram showing a part of the link average travel time data table.

First, the destination D at 8:00 am on Sunday
It is assumed that the departure place ST is departed for S. The navigation device receives the latest traffic information from the outside and uses the traffic information to search for a route. In this case, the departure place ST
From the starting point ST by starting the search from the starting point ST and the destination DS alternately by the Dijkstra method or starting the search from the starting point ST when the running time is one hour (preset time). Points PS1, PS reached in time
Find 2, PS3 and PS4. That is, when the departure place ST is departed at 8:00 am, these points PS1, P
We will arrive at S2, PS3 and PS4 at 9:00 am.

Next, a route from each point of PS1, PS2, PS3 and PS4 to the destination DS is searched. That is,
Find the estimated time the vehicle will reach the starting point of the link, then
Repeat the calculation of finding the time to reach the end point of the link from the link average travel time data table,
Find the expected time to reach the destination DS. For example, in FIG.
In, when calculating the route from PS1 to the destination DS, the estimated arrival time of PS1 is 9:00 am
The scheduled time to reach the end point of the link Li starting from PS1 is 9:20 am from the link average travel time data table (see FIG. 5). Similarly, the link Li + 1
The scheduled time to arrive at the end of the time is 9:50 am.
In this way, the time to reach the destination DS from PS1 is calculated. Similarly to this, PS2, PS3, PS4
The average travel time read from the link average travel time data table is added along each route from to destination DS to obtain the time to reach the destination DS for each route. Then, of these routes, the route with the shortest time is set as the guide route. Since the link average travel time data table has only 10-minute data, the average travel time at an intermediate time (for example, 9:07 am) uses the average travel time at the time closest to that time. To do.

FIG. 6 is a flow chart showing the operation of the vehicle-mounted navigation device of the present embodiment when searching for a guide route. First, in step S1, it is checked whether traffic information can be received from the outside. If the vehicle is out of the traffic information reception range (NO), step S
2, the data of the same day of the week is read from the link average travel time data table in the memory 9 to search for the route with the shortest required time. Then, this route is used as a guide route.

On the other hand, if YES in step S1, the process proceeds to step S3, and the received traffic information is used to search for the shortest route to the destination. Then, the process proceeds to step S4. In step S4, it is checked whether there is a route to reach the destination within one hour. If yes,
The process proceeds to step S5, and of the routes searched using the received traffic information, the route with the shortest time is set as the guide route.

If NO in step S4, step S4
Go to 6. Then, the route from the point reached in 1 hour to the destination is searched for using the link average travel time data table stored in the memory 9 (see FIG. 4). After that, the process proceeds to step S7, and the link that is closed or restricted is extracted from the latest traffic information received by the optical beacon, the radio wave beacon, or the FM multiplex broadcast. Then, the process proceeds to step S8, and it is checked whether or not the closed route is included in the route searched in step S6. If the closed link is included (YES), the process proceeds to step S12, the cost of the closed link is replaced with infinity, and a new route is re-searched.
Return to.

If NO in step S8, step S8
It shifts to 9 and it is checked whether the selected route includes a link for traffic regulation. In the case of NO, the searched route is set as the guide route. If YES, step S1
The travel time of the link subject to traffic regulation is shifted to 0 and multiplied by a predetermined value to obtain the travel time of the link, and the time required to reach the destination is recalculated. Then, in step S11, the calculated required time is compared with the required times of other routes to check whether or not the route has the shortest time. If yes,
The route is defined as a guide route. If NO, step S
The process moves to 12 and a new route is searched again.

In the present embodiment, when the time required from the starting point to the destination is within one hour, the guidance is made using the latest link travel time acquired via the beacon receiver 5 or FM receiving unit 6. When the route is searched and the time required to reach the destination exceeds one hour, the guide route is searched using the past link travel time stored in the memory 9. Therefore, the congestion that will occur or the congestion that will be resolved from now on. The time required to reach the destination can be calculated by taking into consideration. As a result, a guide route that reaches the destination in the shortest time can be obtained.

In the above embodiment, the case where the average value of the link travel time for 4 weeks is stored in the memory 9 has been described, but the memory 9 may store the link travel time for 1 week. The average value of the link travel times of 5 weeks or more may be stored. Also,
In step 10 above, the link travel time of the restricted link may use the link travel time obtained from the latest traffic information data.

Further, the user may be allowed to appropriately select whether or not to use the link average travel time data table stored in the memory 9 when searching for the guide route.

[0032]

As described above, according to the present invention,
Since the past traffic information is stored in the past data storage means separately for each time, it becomes possible to calculate the cost in consideration of the traffic jam that will occur and the traffic jam that will be solved for each route.
The arrival time to the destination can be obtained more accurately. As a result, there is an effect that a guide route that can reach the destination in the shortest time can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a vehicle-mounted navigation device according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing links.

FIG. 3 is a diagram schematically showing a data storage area of a traffic information data memory that stores past traffic information.

FIG. 4 is a diagram showing a road between a departure place ST and a destination DS.

FIG. 5 is a diagram showing a part of a link average travel time data table.

FIG. 6 is a flowchart showing an operation of the vehicle-mounted navigation device of the present embodiment when searching for a guide route.

FIG. 7 is a diagram showing a conventional problem.

[Explanation of symbols]

1 Navigation device body 2 monitors 3 CD-ROM 4 GPS receiver 5 Beacon receiver 6 FM multiplex reception unit 7 Gyro 8 Vehicle speed pulse detector 9 memory

Claims (4)

(57) [Claims] 1. A vehicle-mounted navigation device that searches for a guide route to a destination based on traffic information sent from the outside, comprising: traffic information receiving means for receiving the traffic information; and receiving from the traffic information receiving means. Using past data storage means for storing the traffic information divided by time, and the latest traffic information acquired through the past traffic information stored in the past data storage means and the traffic information receiving means. An in-vehicle navigation device, comprising: a guide route searching means for searching the guide route. 2. The vehicle-mounted navigation device according to claim 1, wherein the past data storage unit stores the past traffic information for at least one week by dividing the traffic information for each day of the week. 3. The vehicle-mounted navigation device according to claim 1, wherein the past data storage means stores an average value of the past traffic information for two weeks or more by dividing the average value for each day of the week. 4. Based on traffic information sent from outside
In-vehicle navigation that searches for guide route to destination
In emission devices, past stores the a traffic information receiving means for receiving traffic information, past traffic information separately for each time data SL
Storage means and the past traffic information stored in the past data storage means
Information and the latest communication obtained through the traffic information receiving means.
Guided route search to search for the guided route using communication information
Means and the guide route searching means is provided via the traffic information receiving means.
To the destination based on the latest traffic information received by
Calculate the required time and drive within the preset time.
Based on the latest traffic information, the guide route for a certain time is searched for based on the past data.
Search using past traffic information stored in storage means
An in-vehicle navigation device characterized by searching.