JP2007040875A - Traffic information transmitter and traffic information transmitting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To transmit traffic information added with a plurality of informations to a navigation system. <P>SOLUTION: A transmission data forming part 303a forms traffic information added with a plurality of informations in a block or mesh unit on a map data. The data transmission part 303b transmits the traffic information formed in the transmission data forming part 303a to the navigation system 200. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a traffic information transmitting device and a traffic information transmitting method for transmitting traffic information to a navigation device mounted on a vehicle.

The following data block coding method for road traffic information is known from Patent Document 1. According to this method, the road traffic information created at the traffic information distribution center is blocked,
It is sent to the navigation device in packet format.

JP 2001-101580 A

  However, in the conventional traffic information transmission method, there is a problem that the current traffic jam information for traffic information display and the predicted traffic information for route search must be transmitted separately.

  The present invention relates to a traffic information transmitting apparatus and method for transmitting traffic information to a navigation apparatus mounted on a vehicle, and creates transmission information composed of a plurality of traffic information for each predetermined range on a map. The generated transmission information is transmitted to the navigation device.

  According to the present invention, transmission information composed of a plurality of traffic information is created and transmitted. As a result, a plurality of traffic information can be transmitted in a single transmission process.

  FIG. 1 is a block diagram showing a configuration of an embodiment of a navigation system according to the present embodiment. The navigation system 100 includes a navigation device 200 mounted on a vehicle, and an information center 300 as a traffic information transmission device that distributes traffic information to the navigation device 200.

  The navigation device 200 includes a vehicle speed sensor 201 that detects the vehicle speed of the host vehicle, a GPS unit 202 that receives a GPS signal from a GPS (Global Positioning System) satellite and detects the current position of the host vehicle, and a traveling direction of the host vehicle. A gyro sensor 203, an input switch 204 operated by a user, a disk reading device 205 for reading map data from the map disk 205a, a control device 206 including a CPU, a memory, and other peripheral circuits, A monitor 207 that displays various information such as a road map and estimated travel time to the destination, a speaker 208 that outputs voice such as guidance voice, and a communication device 209 that communicates with the information center 300 are provided.

  The map disk 205a stores map data of a plurality of scales (scale ratios), and the stored map data includes road data in which a road map is expressed by nodes and links. In road data, nodes correspond to intersections, and line segments connecting the nodes, that is, road sections correspond to links. In the present embodiment, a node ID is assigned as an identification number to each node, and a link ID is assigned to each link as an identification number.

  The map data of the present embodiment is managed by the concept of blocks and meshes, and the minimum unit obtained by dividing the map of each scale corresponds to the scale mesh, and there is a range where one or more meshes are gathered. Corresponds to the block. In this embodiment, an example in which a secondary mesh is used as a mesh will be described.

  For example, as shown in FIG. 2A, each region A1 to K10 obtained by dividing a map into a grid corresponds to a secondary mesh, and a unit in which two or more secondary meshes indicated by A1 to K10 are collected. For example, a unit in which two secondary meshes A1 and A2 are combined corresponds to a block. A mesh ID and a block ID for uniquely identifying each secondary mesh and block are added.

  The control device 206 includes a route search unit 206a, a traffic information acquisition unit 206b, and a congestion level display unit 206c. When the destination is set by the user and the route search to the destination is instructed, the route search unit 206a is preset by the user with the current position of the vehicle detected by the GPS unit 202 as the departure point. Based on the search conditions, the optimum route to the destination is searched.

  When the route search unit 206a searches for a route to the destination, the traffic information acquisition unit 206b requests the information center 300 to transmit traffic information, which will be described later, and acquires the traffic information. When requesting transmission of traffic information to the information center 300, information for identifying the current position of the host vehicle detected by the GPS unit 202 as the departure place and the destination set by the user, for example, departure The latitude / longitude information of the ground, the latitude / longitude information of the destination, and the mesh ID through which the route searched by the route search unit 206a passes are transmitted to the information center 300.

  Based on the traffic information received from the information center 300, the congestion level display unit 206c draws the current congestion level on the route searched by the route search unit 206a and displays it on the monitor 207. In addition, the estimated travel time to the destination is displayed. The congestion level is displayed in three levels, for example, “traffic jam”, “crowded”, and “smooth”, and “driving” is red, “crowded” is orange, and “smooth” is blue. It is drawn in different colors so that the person can easily see the traffic jam situation on the map. The traffic information received from the information center will be described later.

  The information center 300 acquires traffic information including traffic jam information distributed via FM multiplex broadcasting, optical beacons, radio beacons, etc. and time required to pass each link (link travel time). A traffic information database 302 that stores traffic information acquired by the traffic information acquisition device 301 and statistical information of the traffic information, a control device 303 including a CPU, a memory, and other peripheral circuits, and the navigation device 200 described above. And a communication device 304 that communicates with each other.

  The control device 303 includes a transmission data creation unit 303a and a data transmission unit 303b. When the transmission of traffic information is requested from the navigation device 200, the transmission data creation unit 303a receives the latitude / longitude information of the departure place, the latitude / longitude information of the destination received from the navigation device 200, and the route searched by the route search unit 206a. The transmission traffic information in a range including the set route is created in consideration of the mesh ID through which is passed.

  The transmission traffic information is the above-described block-unit traffic information in a range including the set route, and the transmission traffic information includes an estimated time (link travel) required to travel the link included in each block. Time), the degree of congestion at each link, and information on secondary meshes constituting each block.

  The link travel time included in the transmission traffic information is calculated by calculating the required time to the destination and the arrival time at the destination when re-searching the route to the destination by the route search unit 206a described above. This information is used as search information when presented on the screen. That is, the information used by the navigation device 200 to search for a route. In addition, the congestion level included in the transmission traffic information is information used when the congestion level display unit 206c displays the congestion level on the route as described above. That is, it is information used by the navigation device 200 to display traffic information.

  The transmission data creation unit 303a performs the following processing to create such transmission traffic information. First, the above-described congestion degree is calculated based on the congestion information included in the traffic information acquired by the traffic information acquisition device 301. That is, based on the traffic jam information, the current traffic jam level for each link is classified into three levels: “traffic jam”, “crowded”, and “smooth”.

  Next, the link travel time of each link included in the route is estimated. That is, on the route set by the navigation device 200, the road situation of each link at the time of passing each link is predicted based on the statistical information stored in the traffic information database 302, and each link is passed. The estimated value of the link travel time at the point of time is calculated. That is, the link travel time according to the distance from the host vehicle is estimated based on the statistical information of the traffic information.

  Then, adjacent meshes with the same estimated link travel time are grouped into blocks, and a set of current meshes (current conditions), link travel times, and secondary mesh information constituting the blocks for each block. Create as transmission traffic information.

  For example, when the route being searched is a route 2a as shown in FIG. 2, the traffic information for transmission is created as follows. First, as shown in FIG. 2A, the current congestion degree (current state) in the mesh in the vicinity of the route 2a is acquired and classified. Then, as shown in FIG. 2B, adjacent meshes having the same estimated link travel time are grouped, and the estimated link travel time for each block is set as information # 1 to information #n, respectively.

  When the current position of the host vehicle is in the secondary mesh B9, the link travel time is not estimated for the secondary mesh B9 and is included in the traffic information acquired by the traffic information acquisition device 301. Use current link travel time (current status). That is, since it is not necessary to estimate the link travel time at a point where the host vehicle is currently traveling, the link travel time acquired by the traffic information acquisition device 301 is used as it is.

  The data transmission unit 303b transmits the transmission traffic information created for each block in this way to the navigation device 200 in a data format as shown in FIG. 3, for example. According to the example shown in FIG. 3, the congestion degree of the block 1 composed of the secondary mesh B9 including the current position of the host vehicle is “present”, and the link travel time is also “present”. The block 2 closest to the current position of the host vehicle is composed of the secondary meshes A8, A9, A10, B8, B10, C8, C9, and C10, the congestion level is “present”, and the link travel time is “Information # 1”.

  Further, the block 3 includes secondary meshes B7, C6, and C7, the congestion degree is “present”, and the link travel time is “information # 2”. The block 4 is composed of secondary meshes D5, D6, E5, E6, and F6, the congestion degree is “present”, and the link travel time is “information # 3”.

  As described above, since the transmission traffic information includes the two traffic information of the congestion level and the link travel time for each block and is transmitted to the navigation device 200, the conventional traffic information that can transmit only one information at a time. Compared with this transmission method, information required by the navigation device 200 can be sent together in one transmission process, and the amount of communication can be reduced. In other words, the navigation device 200 can obtain transmission traffic information including a plurality of traffic information necessary for a single transmission request (information download), and can reduce the amount of communication.

  In addition, the current congestion degree is transmitted, and the link travel time is transmitted based on the statistical information based on the estimated value at the time when the vehicle actually travels each link. In this way, in general, the driver can display the degree of traffic congestion according to the driver's needs, taking into account that the current situation of traffic congestion is often desired. Moreover, the accuracy of the link travel time can be improved by calculating the link travel time according to the distance from the host vehicle based on the statistical information.

  FIG. 4 is a flowchart showing the processing of the navigation device 200 in the present embodiment. The processing shown in FIG. 4 is executed by the control device 206 as a program that starts when the navigation device 200 is powered on.

  In step S10, it is determined whether a destination is set by the user and a route search is instructed. If it is determined that the route search is instructed, the process proceeds to step S20. In step S20, the route search unit 206a searches for the optimum route to the destination based on the search conditions set in advance by the user, using the current position of the host vehicle detected by the GPS unit 202 as the departure point. Then, it progresses to step S30.

  In step S30, as described above, the traffic information acquisition unit 206b requests the information center 300 to transmit traffic information, and proceeds to step S40. In step S40, it is determined whether traffic information is received from the information center 300 or not. If it is determined that the traffic information has been received, the process proceeds to step S50. In step S50, the congestion level display unit 206c draws the above-described congestion level on the route based on the congestion level included in the received traffic information. Further, based on the link travel time included in the received traffic information, the estimated arrival time at the destination is calculated and displayed on the monitor 207.

  Thereafter, the process proceeds to step S60, where it is determined whether or not the user has instructed a route re-search. If it is determined that the route re-search is not instructed, the process proceeds to step S80 described later. On the other hand, if it is determined that the route re-search is instructed, the process proceeds to step S70. In step S70, the route to the destination is re-searched so as to preferentially select, for example, a road that is not congested in consideration of the traffic information received from the information center 300. Thereafter, the process proceeds to step S80.

  In step S80, it is determined whether or not the navigation apparatus 200 is powered off. If it is determined that the power is not turned off, the process returns to step S10 and the process is repeated. On the other hand, if it is determined that the power is turned off, the process is terminated.

  FIG. 5 is a flowchart showing processing of the information center 300 in the present embodiment. The process shown in FIG. 5 is executed by the control device 303 as a program that is activated when a traffic information transmission request is received from the navigation device 200.

  In step S110, the transmission data creation unit 303a, based on the traffic jam information included in the traffic information acquired by the traffic information acquisition device 301, includes a block unit in a range including the route set by the navigation device 200 as described above. Calculate the degree of traffic congestion. Thereafter, the process proceeds to step S120, and the link travel time of each link included in the route is estimated as described above. Thereafter, the process proceeds to step S130.

  In step S130, as shown in FIG. 3, transmission traffic information including a set of link travel time for each block, congestion degree, and information of the secondary mesh constituting each block is created, and the process proceeds to step S140. move on. In step S140, the transmission data creation unit 303a transmits the traffic information for transmission created by the transmission data creation unit 303a to the navigation device via the communication device 304, and ends the process.

According to the present embodiment described above, the following operational effects can be obtained.
(1) The transmission traffic information includes two pieces of information, ie, the degree of congestion for each block and the link travel time, and is transmitted to the navigation device 200. As a result, compared with the conventional traffic information transmission method in which only one information can be transmitted at a time, the information required by the navigation device 200 can be sent together in one transmission process, and the amount of communication can be reduced. Can be reduced.

(2) The congestion level included in the transmission traffic information is the current congestion level, that is, the current status, and the link travel time is estimated based on the traffic information and statistical information. The navigation device draws and displays the current congestion level on the route based on the received congestion level, and displays the estimated arrival time at the destination based on the link travel time. In this way, in general, the driver can display the degree of traffic congestion according to the driver's needs, taking into account that the current situation of traffic congestion is often desired. In addition, the accuracy of the estimated arrival time at the destination can be improved.

-Modification-
In addition, the navigation system of embodiment mentioned above can also be deform | transformed as follows.
(1) In the above-described embodiment, the example in which the transmission traffic information is created in units of blocks as shown in FIG. 3 has been described. However, the present invention is not limited to this. For example, as shown in FIG. 6, transmission traffic information may be created in units of secondary meshes. For example, FIG. 6 shows that the congestion degree of the secondary mesh 1 configured by the secondary mesh B9 including the current position of the host vehicle is “present” and the link travel time is also “present”.

(2) In the example shown in FIG. 6, an example in which each secondary mesh includes one link is shown, but the present invention is not limited to this. For example, as shown in FIG. A plurality of links may be included. That is, in the example shown in FIG. 7, the secondary mesh 1 composed of the secondary mesh B9 including the current position of the host vehicle includes the link 1 on which the host vehicle is currently traveling and the link 2 connected to the destination. It is. The congestion level of link 1 is “present”, the link travel time is also “present”, and the congestion level of link 2 is “present” and the link travel time is “information # 1”. Thereby, even when the traffic information in each link included in the same secondary mesh is different, it is not necessary to transmit the traffic information to the navigation device 200 for each link, and the data amount can be reduced.

(3) In the example illustrated in FIG. 7, the case where a plurality of links are included in one secondary mesh has been described. In this case, the degree of congestion and the links are continuous links included in one secondary mesh. If the travel times coincide with each other, the data on either one of the congestion levels and the link travel time may be omitted. For example, as shown in FIG. 8, in the secondary mesh 1 composed of the secondary mesh B9 including the current position of the host vehicle, the degree of congestion between the link 1 on which the host vehicle is currently traveling and the link 2 connected to the link 1 ahead. When the link travel times are equal, the traffic level for link 2 and the data of the link travel time are omitted and the transmission traffic information is created. As a result, it is possible to delete duplicate data and reduce the amount of data transmitted to the navigation device 200.

(4) In the above-described embodiment, the navigation apparatus 200 has described an example in which the information center 300 is requested to transmit a set of congestion degree and link travel time for each block as traffic information on the searched route. . However, the present invention is not limited to this, and it is possible to request at least one of the congestion degree and the link travel time for each block or secondary mesh. You may make it produce the traffic information for transmission containing at least any one of a degree and link travel time. For example, as shown in FIG. 9, the secondary mesh 1 composed of the secondary mesh B9 includes only the traffic congestion degree, and the secondary mesh 2 composed of the secondary mesh A8 includes only the link travel time. The secondary mesh 6 composed of the mesh B10 may create traffic information for transmission including a congestion degree and a link travel time. As a result, the navigation device 200 can request only the necessary information and receive traffic information including only the requested information, delete unnecessary data from the transmission data, and reduce the traffic. Can be reduced.

(5) In the embodiment and the modification described above, the example in which the transmission traffic information is generated for each block or secondary mesh using the block or the secondary mesh as the transmission traffic information generation unit has been described. However, the present invention is not limited to this, and a predetermined range that can be identified on map data may be used as a unit for creating transmission traffic information.

  Note that the present invention is not limited to the configurations in the above-described embodiments as long as the characteristic functions of the present invention are not impaired.

  The correspondence between the constituent elements of the claims and the embodiment will be described. The transmission data creation unit 303a corresponds to traffic information creation means, and the data transmission unit 303b corresponds to transmission means. The above description is merely an example, and when interpreting the invention, there is no limitation or restriction on the correspondence between the items described in the above embodiment and the items described in the claims.

It is a block diagram which shows the structure of one Embodiment of a navigation system. It is a figure which shows the acquisition example of the traffic information in the searched path | route. It is a figure which shows the specific example of the traffic information for transmission. 6 is a flowchart showing processing of the navigation device 200. FIG. 6 is a flowchart showing processing of the information center 300. FIG. It is a 1st figure which shows the modification of the traffic information for transmission. It is a 2nd figure which shows the modification of the traffic information for transmission. It is a 3rd figure which shows the modification of the traffic information for transmission. It is a 4th figure which shows the modification of the traffic information for transmission.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Navigation system 200 Navigation apparatus 201 Vehicle speed sensor 202 GPS unit 203 Gyro sensor 204 Input switch 205 Disk reader 205a Map disk 206, 303 Controller 206a Route search part 206b Traffic information acquisition part 206c Congestion degree display part 207 Monitor 208 Speaker 209 304 Communication Device 300 Information Center 301 Traffic Information Acquisition Device 302 Traffic Information Database 303a Transmission Data Creation Unit 303b Data Transmission Unit

Claims (7)

A traffic information transmitting device for transmitting traffic information to a navigation device mounted on a vehicle,
Traffic information creating means for creating transmission information composed of a plurality of traffic information for each predetermined range on the map;
A traffic information transmitting apparatus comprising: a transmitting means for transmitting the transmission information created by the traffic information creating means to the navigation device. The traffic information transmitting device according to claim 1,
The plurality of traffic information includes display information used by the navigation device to display traffic information and search information used by the navigation device to search for a route. Transmitter device. In the traffic information transmitter according to claim 2,
The display information is information indicating a current traffic jam degree,
The information for search is a travel time estimated for each link according to the distance from the host vehicle. In the traffic information transmitting device according to claim 3,
The search information is a travel time estimated for each link when the host vehicle passes through each link. In the traffic information transmitting device according to any one of claims 1 to 4,
The traffic information transmitting apparatus, wherein the predetermined range on the map is a block identified on the map data. In the traffic information transmitting device according to any one of claims 1 to 4,
The traffic information transmitting apparatus, wherein the predetermined range on the map is a mesh identified on the map data. A traffic information transmission method for transmitting traffic information to a navigation device mounted on a vehicle,
For each predetermined range on the map, create transmission information consisting of multiple traffic information,
A traffic information transmission method comprising transmitting the created transmission information to the navigation device.

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