JP2004257829A - Navigation system for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To select and accumulate only traffic information required for a user, and to set a guidance route avoiding a road, where the occurrence of congestion is predicted according to the accumulated traffic information. <P>SOLUTION: Schedule information, such as a departure location, a destination, and a departure date/time for departing from the departure location, is registered in advance (step S100), and a plurality of candidate routes reaching the destination are calculated from the departing location (step S110). Then, only congestion information regarding the candidate route is collected and accumulated (steps S140-S160). As a result, the congestion information to be accumulated is restrained to only required information, and the congestion information of each candidate route is referred to, thus precisely setting a guidance route avoiding a road, where the occurrence of congestion is predicted. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vehicle navigation system for performing route guidance to a destination, and more particularly to a vehicle navigation system for setting a guidance route avoiding a congested road and performing route guidance according to the guidance route.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, traffic information related to congestion and regulation is provided by a system such as a VICS (Vehicle Information and Communication System). Therefore, a navigation device equipped with a VICS receiver receives the VICS information to display information such as traffic congestion and regulations of the surrounding area together with a road map, and to set a guide route to a destination. A route can be set so as to avoid a road.
[0003]
However, the traffic information that can be obtained by a system such as VICS relates to traffic congestion that has actually occurred. Therefore, even if the user starts traveling on a road where no congestion has occurred at the present time toward the desired destination, the user actually travels on the road, that is, congestion occurs at a future point in time. There was a case that I was caught in traffic.
[0004]
To solve such a problem, for example, Patent Literature 1 discloses a device that stores past road traffic information and predicts future road traffic information from the road traffic information. That is, when road traffic information such as traffic congestion information and regulation information is received, it is stored in a storage unit together with related information such as time, date, day of the week, and weather information. Then, based on conditions such as a road name, a time, a date, a day of the week, and weather, the stored data is searched for road traffic information substantially matching the conditions. When the conditions such as the road name, time, date, day of the week, and weather match, it is highly possible that the road traffic conditions are similar. Therefore, search results are displayed, which is useful for users in predicting future traffic conditions.
[0005]
[Patent Document 1]
JP 2001-118188 A
[Problems to be solved by the invention]
However, in the above-described conventional apparatus, when road congestion information and regulation information are received, all the road traffic information is stored together with the related information, so that the amount of information to be stored becomes enormous.
[0007]
In addition, in the above-described conventional apparatus, the information actually used by the user is only a part of information stored in the stored information that matches the search condition, and most of the information is used by the user. There is no. Therefore, the conventional device accumulates a large amount of useless information that is unlikely to be used.
[0008]
The present invention has been made in view of such a problem, and it is possible to select and accumulate only traffic information necessary for a user, and to set a guidance route avoiding a congested road by the accumulated traffic information. It is an object of the present invention to provide a simple vehicle navigation device.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a vehicle navigation system according to claim 1,
Map information storage means for storing road map information;
Registration means for pre-registering a departure place, a destination and a departure date departing from the departure place;
Candidate route searching means for searching for a plurality of candidate routes from the starting point to the destination based on the road map information stored in the map information storing means;
Prior to the departure date, congestion information storage means for collecting and accumulating traffic information on a plurality of candidate routes searched by the candidate route search means;
A guide route setting unit that sets a final guide route based on the traffic jam information of the plurality of candidate routes stored in the traffic jam information storage unit;
Route guidance means for performing route guidance in accordance with the guidance route set by the guidance route setting means.
[0010]
As described above, in the vehicle navigation system according to the first aspect, the departure place, the destination, and the departure date departure from the departure place are registered in advance, and the traffic congestion information on the plurality of candidate routes from the departure place to the destination is registered. Collect and accumulate only. Therefore, the accumulated traffic congestion information can be limited to only information necessary for setting a final guidance route. Then, by referring to the traffic jam information of each candidate route accumulated before the departure date, it is possible to accurately set a guidance route that avoids a road on which traffic jam is predicted to occur.
[0011]
As described in claim 2, the guide route setting means sets a tentative guide route based on the latest traffic jam information at the time of setting the final guide route, and stores the traffic jam information stored in the traffic jam information storage means. Based on the above, if it is predicted that a traffic jam will be encountered when traveling on the temporary guide route, the final guide route is set by modifying the temporary guide route so as to avoid the traffic jam encounter route Is preferred. When the final guide route is set in this way, it is possible to set a guide route that takes into account the current traffic jam situation and the traffic jam situation that is expected to occur in the future.
[0012]
As described in claim 3, the congestion information accumulating means divides each of the plurality of candidate routes into a plurality of constituent roads constituting the candidate route, and classifies the congestion information for each of the constituent roads and accumulates the classified information. Is preferred. As a result, it is easy to set a guide route that bypasses the traffic congestion location.
[0013]
Further, as described in claims 4 and 5, it is preferable that the traffic jam information accumulating means accumulates traffic jam information relating to a plurality of candidate routes by classifying them by time zone and day of the week. This is because depending on the road, there is a traffic jam only on a specific day of the week or a time zone when the traffic jam becomes severe.
[0014]
Further, as described in claim 6, the registration means also registers a departure time at which the vehicle departs from the departure place, and the congestion information storage means stores only the congestion information regarding a plurality of candidate routes in a time zone corresponding to the departure time. You may make it collect and accumulate. By doing so, the information to be stored can be further narrowed down, and the amount of information to be stored can be reduced.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a vehicle navigation system according to an embodiment of the present invention will be described with reference to the drawings.
[0016]
FIG. 1 is a block diagram showing a schematic configuration of a vehicle navigation system 20 according to the present embodiment. As shown in FIG. 1, a vehicle navigation system 20 according to the present embodiment includes a position detector 1, a map data input device 6, an operation switch group 7, a display device 9, a VICS receiver 10, a mobile phone connection device 11, an external device. A memory 12 and a navigation ECU 8 as a control circuit connected thereto are provided.
[0017]
The navigation ECU 8 is configured as a normal computer, and includes a well-known CPU, ROM, RAM, I / O, and a bus line connecting these components. A program to be executed by the navigation ECU 8 is written in the ROM, and the CPU and the like execute predetermined arithmetic processing according to the program.
[0018]
The position detector 1 includes a well-known geomagnetic sensor 2, a gyroscope 3, a distance sensor 4, and a GPS receiver 5 for a GPS (Global Positioning System) that detects the position of a vehicle based on radio waves from satellites. Have. These are configured to be used while being complemented by a plurality of sensors, since each has an error having a different property. Note that, depending on the accuracy of each sensor, the position detector 1 may be constituted by a part of the above.
[0019]
The map data input device 6 is a device that inputs map data necessary for drawing a map such as node data, link data, and landmark data such as place names to the navigation ECU 8. The map data input device 6 includes a storage medium for storing map data. As the storage medium, a CD-ROM, a DVD-ROM, or the like is generally used depending on the amount of data to be stored. A rewritable medium such as a hard disk may be used.
[0020]
Here, configurations of the node data and the link data will be described. The node data includes a node ID assigned with a unique number for each node where a plurality of roads intersect, merge, and branch, a node coordinate, a node name, and a connection link ID describing link IDs of all links connected to the node. It is composed of data such as an intersection type, the presence or absence of a traffic light, and regulation information.
[0021]
On the other hand, link data includes a link ID with a unique number for each road, a link length, node coordinates of a start point and an end point, road types such as expressways, toll roads, general roads, and urban / suburban roads, road widths, and lanes. It consists of data such as number, link running time and legal speed limit. That is, the link of the link data is such that each road on the map is divided into a plurality of nodes by nodes indicating intersections, branch points, and the like, and two nodes are defined as links. Note that the coordinates of the start and end of the link are described in the node coordinates of the start point and the end point.
[0022]
With these node data and link data, it is possible to draw a road on a map, or to calculate a guidance route from a departure place to a destination using a known technique such as the Dijkstra method.
[0023]
The operation switch group 7 is configured as, for example, a touch switch or a mechanical switch integrated with a display device 9 described later, and is used for various inputs. The navigation device 20 of the present embodiment has a schedule management function in addition to a normal navigation function, and a departure place, a destination, and a departure date and time of departure from the departure place can be registered in advance by the operation switch group 7. It is possible. The registered schedule information is displayed on the display device 9 in units of month, week, day, and the like. The schedule information displayed on the display device 9 includes a departure place, a destination, a departure date and time, and an estimated arrival time.
[0024]
The display device 9 is configured by, for example, a liquid crystal display. In addition to the above-described schedule information, the screen of the display device 9 includes, for example, a vehicle position mark corresponding to the current position of the vehicle input from the position detector 1, A road map around the vehicle generated by the map data input from the map data input device 6 is displayed.
[0025]
Further, when a destination is input from the operation switch group 7, the navigation device 20 of the present embodiment automatically searches for an optimal route from the current position (or a departure point designated by the user) to the destination. It also has a so-called route guidance function for forming and displaying a guidance route. At the time of this route guidance, a road map in which the guidance route is highlighted is displayed on the screen of the display device 9.
[0026]
The VICS receiver 10 is a device that receives road traffic information distributed from a VICS center via beacons laid on roads and FM broadcast stations in various places. The received road traffic information is processed by the navigation ECU 8, and, for example, traffic congestion information and regulation information are displayed superimposed on a road map.
[0027]
The mobile phone connection device 11 is a device for connecting the mobile phone and the navigation ECU 8, and allows the mobile phone to access an external communication infrastructure such as the Internet. Thereby, the navigation ECU 8 can collect road traffic information such as traffic congestion information and regulation information provided on the Internet, for example. Instead of using a mobile phone, a communication module that can communicate with an external infrastructure may be provided.
[0028]
As will be described later in detail, when the VICS receiver 10 or the mobile phone connection device 11 acquires congestion information on a candidate route between the departure place and the destination registered as schedule information, the external memory 12 Is stored in
[0029]
The external memory 12 stores each schedule information registered by the operation switch group 7. Further, as described above, the external memory 12 stores the congestion information on each candidate route between the departure point and the destination in the schedule information.
[0030]
The guide route setting process using the schedule management function in the vehicle navigation system 20 having the above-described configuration will be described with reference to the flowchart of FIG.
[0031]
First, in step S100, a departure place, a destination, and a departure date and time departure from the departure place are input by the operation switch group 7. Thereby, the schedule information is registered in the navigation device 20. As for the input of the schedule information, the schedule information may be downloaded from an external information terminal such as a PDA (portable information terminal) equipped with schedule management software or a personal computer.
[0032]
When the schedule information is registered, in step S110, a plurality of candidate routes from the departure point to the destination in the schedule information are searched. For example, as in the example shown in FIG. 3, five candidate routes from the departure point (Start) to the destination (Goal) are calculated. Note that, among the candidate routes shown in FIG. 3, route 1 is a route that reaches the destination (Goal) from the starting point (Start) via the points B and D. The route 2 is a route from the departure point (Start) to the destination (Goal) via the points A, B, and D. Route 3 is a route from the starting point (Start) to the destination (Goal) via the points B and C. The route 4 is a route from the starting point (Start) to the destination (Goal) via the points A, C, and D. Finally, the route 5 is a route from the starting point (Start) to the destination (Goal) via the points A and C.
[0033]
Next, in step S120, by comparing the departure date and time of the registered schedule information with the current date and time, it is determined whether or not there is, for example, 24 hours or more before the reservation date and time. At this time, if it is determined to be “YES”, the process proceeds to step S130, where the navigation ECU 8 is in the idling state, that is, the route search and the communication with the outside are not performed, and the operation is in the low load state. Is determined. If the navigation ECU 8 is in the idling state, the navigation ECU 8 proceeds to step S140 and thereafter to perform processing such as acquisition of traffic congestion information on the candidate route since there is enough processing capacity. On the other hand, if it is determined that the vehicle is not in the idling state, the process returns to step S120.
[0034]
In step S140, for example, time information and day information are acquired from calendar information of the navigation device 20. Next, in step S150, the VICS receiver 10 and the mobile phone connection device 11 acquire road traffic information. If the traffic information acquired at this time also includes traffic information on roads other than the candidate route, only the traffic information on the candidate route is extracted. Then, in step S160, the database that stores the traffic jam information of each candidate route is updated using the above-described time information, day of the week information, and traffic information.
[0035]
Specifically, for example, when five candidate routes as shown in FIG. 3 are calculated, each candidate route is configured using the passing points A, B, C, and D, which are branch points of the candidate routes. To be divided into a plurality of constituent roads (SA to DG). Then, the database is updated by classifying and accumulating the acquired traffic congestion information on each of the candidate routes for each of the constituent roads (SA to DG).
[0036]
FIG. 4 shows an example of this database. As shown in FIG. 4, a numerical value as an index indicating the degree of congestion is stored for each of the constituent roads (SA to DG) divided using the passing points A, B, C, and D. The degree of congestion is represented by, for example, five levels. The lower the numerical value, the more the road is free, and the higher the numerical value, the more congestion. In addition, the database stores the degree of congestion of each of the constituent roads (SA to DG) classified by time zone. This is because the degree of congestion on each of the constituent roads (SA to DG) changes depending on the time zone. Further, the database shown in FIG. 4 is accumulated for each day of the week. This is because the degree of congestion on each of the constituent roads (SA to DG) changes depending on the day of the week.
[0037]
The database may store only the traffic congestion information in the time zone corresponding to the departure time at the departure place and the estimated time of arrival at the destination. That is, for each of the calculated candidate routes, the estimated arrival time at the destination is calculated by integrating the link travel time of the link data. Then, the traffic congestion information from the time zone including the departure time to the time zone including the latest arrival time is acquired and accumulated. In this way, it is possible to accurately predict future traffic congestion from traffic congestion information in the same time zone, and to suppress the data amount of traffic congestion information to be accumulated.
[0038]
A database is created by such processing. If the difference from the departure date and time in the schedule information is less than the predetermined value, the process from step S170 is performed to set the final guidance route.
[0039]
In step S170, the latest road traffic information is acquired by the VICS receiver 10 or the mobile phone connection device 11. Then, in step S180, a provisional guidance route is calculated based on the acquired latest road traffic information. As a method of calculating the provisional guidance route based on the road traffic information, a cost corresponding to each route is calculated by multiplying the running time of each link by a coefficient corresponding to the obtained congestion degree, and the route having the smallest cost is calculated. A temporary guidance route is assumed.
[0040]
In step S190, it is determined whether the guidance route calculated in step S180 needs to be corrected. In other words, a database for each guide route has been created, and if there is a possibility of encountering congestion when traveling on a temporary guide route based on past traffic congestion information stored in that database, route correction is required Judge. If the degree of traffic congestion is stored in a database for a plurality of days, a future traffic congestion is predicted with reference to the database of the day of the week under conditions that are as close as possible. That is, if there is a database of the same day of the week, the database is referred to. If there is no database, the database of the same classification is referred to by dividing into weekdays and holidays such as weekends and public holidays. If the route needs to be corrected, a corrected route is calculated in step S200, and this is set as the final guide route.
[0041]
For example, in the example illustrated in FIG. 3, it is assumed that when departing from the departure place at 9:00, the route 5 is set as a temporary guide route based on the latest road traffic information. In this case, if the time zone for driving on the AC that is the constituent road of the route 5 is from 10:00 to 12:00 and the time zone for driving on the constituent road CG is after 12:00, the database shown in FIG. , It can be predicted that there is a high possibility that the user will get caught in traffic on the constituent road AC and the constituent road CG. For this reason, the temporary guide route is corrected to, for example, the route 2 including the constituent roads SA, AB, BD, and DG so as to bypass the constituent roads AC and CG that may encounter traffic jam. Set as
[0042]
That is, by the above-described processing, a temporary guide route is set based on the latest traffic congestion information at the time when the final guide route is set, and the temporary guide route is traveled based on the traffic congestion information stored in the database. If it is predicted that a traffic jam will be encountered in such a case, the temporary guide route can be corrected so as to avoid the traffic jam encounter route, and the final guide route can be set. When the final guide route is set in this way, it is possible to set a guide route that takes into account both the current congestion situation and the congestion situation expected to occur in the future.
[0043]
The preferred embodiment of the present invention has been described above. However, the vehicle navigation system according to the present invention is not limited to the above-described embodiment, and may be variously modified and implemented without departing from the gist of the present invention. be able to.
[0044]
For example, regarding the correction of the provisional guide route, the cost of each candidate route calculated based on the current traffic information is corrected in consideration of the degree of congestion of each constituent road accumulated in the database, and the correction cost is calculated. The route having the lowest cost may be set as the final guidance route.
[0045]
Further, in the above-described embodiment, since it is predicted that traffic congestion will be encountered on the constituent roads AC and CG, the current and future traffic congestion will be performed only on the routes 1 and 2 that do not include the constituent roads AC and CG. It is also possible to perform a cost comparison taking into account the degree and set the route with the lower cost as the final guidance route.
[0046]
Further, in the above-described embodiment, an example has been described in which the navigation system is configured as an in-vehicle device mounted on a vehicle, but a part of the functions may be executed by an external information center. For example, the on-board unit transmits schedule information such as the departure place, destination and departure time to an external information center, and the information center calculates a candidate route from the departure place to the destination, and collects congestion information on the candidate route. , And a final guidance route may be set. In this case, information on the final guidance route is transmitted from the information center to the vehicle-mounted device, and the vehicle-mounted device performs route guidance according to the guidance route.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a schematic configuration of a vehicle navigation system according to an embodiment of the present invention.
FIG. 2 is a flowchart illustrating a guide route setting process using a schedule management function.
FIG. 3 is an explanatory diagram showing an example of calculating a plurality of candidate routes from a departure point (Start) to a destination (Goal).
FIG. 4 is an explanatory diagram illustrating an example of a database when congestion information regarding each candidate route is compiled into a database.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Position detector 6 ... Map data input device 7 ... Operation switch group 8 ... Navigation ECU
9 display device 10 VICS receiver 11 mobile phone connection device 12 external memory 20 vehicle navigation system

Claims (6)

Map information storage means for storing road map information;
Registration means for pre-registering a departure place, a destination and a departure date departing from the departure place;
Candidate route searching means for searching a plurality of candidate routes from the departure place to the destination based on the road map information stored in the map information storage means;
Prior to the departure date, congestion information accumulating means for collecting and accumulating congestion information on a plurality of candidate routes searched by the candidate route searching means,
Guide route setting means for setting a final guide route based on the traffic congestion information of the plurality of candidate routes stored in the traffic congestion information storage means,
A navigation system for a vehicle, comprising: route guidance means for performing route guidance according to the guidance route set by the guidance route setting means. The guide route setting means sets a tentative guide route based on the latest traffic information at the time of setting the final guide route, and based on the temporary traffic information stored in the traffic information storage means, When it is predicted that a traffic jam will occur when traveling along the guide route, a final guide route is set by modifying the temporary guide route so as to avoid the traffic jam encounter route. Item 4. The vehicle navigation system according to item 1. The congestion information accumulating means divides each of the plurality of candidate routes into a plurality of constituent roads constituting the candidate route, and classifies and stores the congestion information for each of the constituent roads. The vehicle navigation system according to claim 1 or 2. The vehicular navigation system according to any one of claims 1 to 3, wherein the congestion information accumulating means classifies and accumulates the congestion information on the plurality of candidate routes according to a time zone. The vehicular navigation system according to any one of claims 1 to 4, wherein the congestion information accumulating means classifies and accumulates the congestion information on the plurality of candidate routes according to a day of the week. The registration unit also registers a departure time at which the departure point departs, and the congestion information accumulation unit collects and accumulates only the congestion information regarding the plurality of candidate routes in a time zone corresponding to the departure time. The vehicle navigation system according to any one of claims 1 to 5, wherein

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