JP2008309572A - Information exchange system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the optimum route guide information further adapted to an actual road state based on information acquired from another vehicle, in an information exchange system for exchanging information by radio communication between each vehicle. <P>SOLUTION: In a first on-vehicle unit, a clocking means clocks a time required for passing a prescribed section on a passing road, a first storage means stores the first road passing information on the clocked time required for passing the prescribed section on the road, a searching means searches for a communicable second on-vehicle unit, a transmission means transmits by radio the first road passing information to the second on-vehicle unit, a reception means receives the second road passing information transmitted by radio from the second on-vehicle unit, the second storage means stores the second road passing information, and a route searching means retrieves a guide route through which a required time to a destination becomes shortest by using the time required for passing the prescribed section on the road included in the second road passing information stored by the second storage means. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an information exchange system.

  2. Description of the Related Art Conventionally, a system that exchanges information by radio communication between traveling vehicles is known.

For example, Patent Document 1 proposes a device that transmits and receives information content only when a vehicle holding a specific type of information content and a vehicle requesting the information content are found. ing.
Further, for example, in Patent Document 2, when the route search center is requested to search for a route to the destination where the vehicle travels, the introduction of another vehicle requesting the route search to the same destination is received. A system is disclosed in which necessary and useful information can be exchanged between vehicles sharing the destination even when the vehicle is moving to the destination by contacting the vehicle that has received the request.
JP 2006-281850 A JP 2003-317189 A

  By the way, when searching for a route that reaches the destination in the shortest time, the route is conventionally searched based on an average required time required for passing through the road. However, since the actual time required for passing the road may be different due to traffic jams or the like, there is a problem that the optimum route is not always searched according to the road conditions at that time.

  An object of the present invention is to provide optimal route guidance information in accordance with actual road conditions based on information acquired from other vehicles in an information exchange system for exchanging information by wireless communication between vehicles. It is to provide an information exchange system that can.

In order to solve the above-mentioned problem, the invention according to claim 1 is an information exchange system for exchanging information between on-vehicle devices respectively mounted on a plurality of vehicles.
The first vehicle-mounted device
A time measuring means for measuring the time required for the passage of a predetermined section on the passing road;
First storage means for storing first road passage information relating to a time required to pass through a predetermined section of the road timed by the time measuring means;
Search means for searching for a second on-vehicle device capable of communication;
Transmitting means for wirelessly transmitting the first road passage information stored by the first storage means to a second vehicle-mounted device searched by the search means;
Receiving means for receiving second road passage information wirelessly transmitted from the second vehicle-mounted device;
Second storage means for storing the second road passage information received by the receiving means;
Current position detecting means for detecting the current position;
Using the time required to pass through a predetermined section of the road included in the second road passage information stored in the second storage means, the current position detected by the current position detection means to the destination Route search means for searching for a guide route with the shortest required time;
Providing means for providing route guidance information related to the guidance route searched by the route search means;
It is characterized by providing.

  According to a second aspect of the present invention, in the information exchange system according to the first aspect, each time the route search means stores the second road passage information by the second storage means, The guide route with the shortest required time is re-searched.

The invention according to claim 3 is an information exchange system for exchanging information between vehicle-mounted devices each mounted on a plurality of vehicles.
The first vehicle-mounted device
A time measuring means for measuring the time required for the passage of a predetermined section on the passing road;
First storage means for storing road passage information relating to the time required for the passage of the predetermined section of the road timed by the time measuring means;
First search means for searching for a second on-vehicle device capable of communicating with the first on-vehicle device;
First transmission means for wirelessly transmitting the road passage information stored by the first storage means to the second vehicle-mounted device searched by the first search means;
The second vehicle-mounted device is:
First receiving means for receiving road passage information wirelessly transmitted from the first vehicle-mounted device;
Second storage means for storing the road passage information received by the first receiving means;
Second search means for searching for a third on-vehicle device capable of communicating with the second on-vehicle device;
A second transmission means for wirelessly transmitting the road passage information stored by the second storage means to the third vehicle-mounted device searched by the second search means;
The third vehicle-mounted device is:
Mounted on a vehicle heading in the same direction as the vehicle on which the first vehicle-mounted device is mounted;
Second receiving means for receiving the road passage information wirelessly transmitted from the second vehicle-mounted device;
Third storage means for storing the road passage information received by the second receiving means;
Current position detecting means for detecting the current position;
The required time from the current position detected by the current position detecting means to the destination is calculated using the time required for the passage of a predetermined section of the road included in the road passing information stored in the third storage means. Route search means for searching for the shortest guide route;
Providing means for providing route guidance information related to the guidance route searched by the route search means;
With
The route search means includes
Each time the road passing information is stored by the third storage means, the guide route that takes the shortest time to the destination is searched again.

According to the present invention, in the first vehicle-mounted device, the time required for passing the predetermined section on the passing road is timed by the time measuring means, and the predetermined section of the road timed by the time measuring means is measured by the first storage means. The first road passage information relating to the time required for passing the vehicle is stored, the searchable second vehicle-mounted device is searched for by the searching means, and the communicable second vehicle-mounted information searched for by the searching means is transmitted by the transmitting means. The first road passage information stored in the first storage means is wirelessly transmitted to the device, and the second road passage information wirelessly transmitted from the second vehicle-mounted device is received by the reception means. The second storage means stores the second road passage information received by the receiving means, detects the current position by the current position detecting means, and stores the second road information stored by the second storing means by the route search means. road The time required to pass through the predetermined section of the road included in the passing information is used, and a guide route that takes the shortest time from the current position detected by the current position detecting means to the destination is searched and provided by the providing means Route guidance information related to the guidance route searched by the route search means is provided.
That is, in the first vehicle-mounted device, the first road passing information related to the time required for the passage of the predetermined section on the road that has passed in the past is transmitted to the second vehicle-mounted device and transmitted from the second vehicle-mounted device. Second road passage information is received. Then, based on the time required for the passage of the predetermined section on the road included in the received second road passage information, the guide route with the shortest required time to the destination is searched. Therefore, in an information exchange system for exchanging information by wireless communication between vehicles, it is possible to provide optimal route guidance information that is more suitable for actual road conditions based on information acquired from other vehicles.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram illustrating an overall configuration of an information exchange system 100 according to the present embodiment.

  As shown in FIG. 1, the information exchange system 100 according to the present embodiment is a system that is used among a plurality of vehicles C. In FIG. 1, for example, the vehicle C1 and the vehicle C3 are traveling in the same direction with the lane A, and the vehicle C2 is traveling in the opposite lane B facing the lane A in the direction facing the vehicles C1 and C3. It is in. Each vehicle C1 to C3 is equipped with first to third vehicle-mounted devices M1 to M3, and according to the traveling of each vehicle C1 to C3, various information such as map information and route search / route guidance to the destination is obtained. , Provide to users.

  Moreover, as shown in FIG. 1, the radio | wireless communication network is constructed | assembled between the vehicles C1-C3 (1st-3rd vehicle equipment M1-M3). This wireless communication network is, for example, an ad hoc network that transmits data using another vehicle-mounted device M existing within a communication range as a relay station. In an ad hoc network, a network can be constructed without providing infrastructure such as a base station or an access point in a wireless local area network (LAN).

In the present embodiment, in the information exchange system 100 of FIG. 1, the first vehicle-mounted device M1 (transmission terminal) mounted on the vehicle C1 traveling on the lane A is mounted on the vehicle C2 traveling on the opposite lane B. In addition, by relaying the second vehicle-mounted device M2 (relay station), the vehicle is headed in the same direction as the vehicle C1 on which the first vehicle-mounted device M1 is mounted, and the first vehicle-mounted device M1 is not directly communicable. The case where information is transmitted to the third vehicle-mounted device M3 (receiving terminal) mounted on the vehicle C3 will be described.
In the following description, the first vehicle-mounted device M1 serves as a transmitting terminal, the second vehicle-mounted device M2 serves as a relay station, and the third vehicle-mounted device M3 serves as a receiving terminal. Only the configuration and processing when fulfilling will be described. However, in the actual information exchange system 100, each of the vehicle-mounted devices M includes a first vehicle-mounted device M1 as a transmitting terminal, a second vehicle-mounted device M2 as a relay station, and a third vehicle-mounted device M3 as a receiving terminal, The vehicle-mounted devices M1 to M3 transmit information to each other as a transmission terminal, a relay station, and a reception terminal.

(First on-board unit)
First, the principal part structure of the 1st onboard equipment M1 mounted in the vehicle C1 is demonstrated, referring FIG.
As shown in FIG. 2, the first vehicle-mounted device M1 includes, for example, a current position detection unit 11, a wireless communication unit 12 as a first transmission unit, a display unit 13, an input unit 14, and a control unit in the apparatus main body. 15 etc. are comprised.

The current position detection unit 11 includes, for example, a GPS positioning unit that detects the absolute coordinates of the first vehicle-mounted device M1, detects the current position information of the first vehicle-mounted device M1 itself, and detects the detected current position information. Based on the current position detection signal, the control unit 15 is output.
Specifically, the GPS positioning unit receives, for example, radio waves from a plurality of (for example, four) artificial satellites whose positions are known by a GPS antenna (not shown), and arrival of the radio waves received from each artificial satellite. From the time, the distance from each artificial satellite to the first vehicle-mounted device M1 is calculated, and the latitude / longitude data of the intersection of the distance from each artificial satellite is specified.
In addition, the current position of the first vehicle-mounted device M1 is detected by an azimuth sensor such as a gyro sensor that detects angular velocity, a travel distance detection unit that detects a travel distance by measuring a pulse according to travel, and the like. May be.

For example, the wireless communication unit 12 exchanges information with the vehicle-mounted device M mounted in another vehicle C existing in the communication range via the wireless communication network.
Further, the wireless communication unit 12 may be connected to an information providing apparatus (not shown) via a network, and may be configured to receive various information such as route guidance and map information transmitted from the information providing apparatus via the network. .

  The display unit 13 includes a display such as an LCD (Liquid Crystal Display), for example, and displays map information and various other information on the display in accordance with control from the control unit 15.

The input unit 14 includes, for example, a character / number key, various function keys, a touch panel integrally formed with the display unit 13, and the like, and the user inputs various information such as a destination point and a departure point.
Specifically, the input unit 14 outputs a key press signal based on the key press by the user to the control unit 15, and calculates the coordinates of the touch operation when the user performs a touch operation on the touch panel. A pressing signal based on the calculated coordinates is output to the control unit 15.
Further, the input unit 14 may be provided in, for example, a remote controller or the like and capable of remote operation.

  The control unit 15 includes a CPU (Central Processing Unit) 151, an RTC (Real Time Clock) 152 as a time measuring unit, a memory unit 153, a ROM (Read Only Memory) 154, and the like.

  The CPU 151 executes various programs stored in the ROM 154 according to input signals input from the respective units of the first vehicle-mounted device M1, and outputs output signals to the respective units based on the execution programs. The overall operation of the first vehicle-mounted device M1 is comprehensively controlled.

The RTC 152 counts the current time and outputs the counted current time to the CPU 151.
Specifically, the RTC 152 is required for the passage of a link (predetermined section) constituting the road on which the vehicle C1 is passing in the execution of the first storage program 154a (described later) executed in accordance with the traveling of the vehicle C1. Time is measured every time the link is crossed.

  The memory unit 153 includes a work area 1531 made of a volatile memory such as a RAM (Random Access Memory), for example, and the processing results generated when various programs are executed by the CPU 151, input data, and the like The work area 1531 is stored.

  The memory unit 153 includes a data area 1532 made of a nonvolatile memory such as an EPROM (Erasable Programmable ROM). The data area 1532 stores, for example, a map information DB 1532a, a first road passage information storage unit 1532b as a first storage unit, and the like.

  For example, the map information DB 1532a stores map information of different types and scales in a hierarchical structure. For example, in addition to roads displayed on high-speed automobile national roads and general national roads, roads displayed on wide-area maps, in addition to roads displayed on prefectural roads and municipal roads, roads displayed on medium-area maps Stores detailed maps with narrow streets. In addition to road information, this map information includes address information, information on buildings, facilities, stores, parks, railways, topographic information, and the like. Further, as needed, the wireless communication unit 12 updates the latest map information downloaded from the information providing device (not shown) via the network N.

The road information included in the map information DB 1532a is composed of node information and link information.
The node information defines link intersections (intersections), link end points (dead ends), and points at which link attributes change (for example, high-speed automobile national roads → prefectural roads). The node information includes, for example, a node ID unique to each node, node coordinates, intersection name, link ID of a link connected to the node, and the like.
The link information defines a link that is a line segment connecting nodes, and a road is constituted by one or a plurality of links. The link information includes, for example, a link ID unique to each link, the coordinates of the node that is the end point (start point / end point) of the link, the link length indicating the link length, the road name, road type, width, number of lanes, traffic regulation The link ID of the link connected to the node that is the end point of the link, the average transit time of the link, and the like are included.

  In the present embodiment, each link constituting a road is described as a “predetermined section” on the road. In the following description, the time required for the passage of the link as the predetermined section is referred to as “link passage time”.

The first road passage information storage unit 1532b stores road passage information (first road passage information) relating to the link passage time of the link on the road on which the vehicle C1 is passing in the execution of the first storage program 154a described later. To do.
FIG. 3 is a diagram illustrating the first road passage information storage unit 1532b. As illustrated in FIG. 3, the first road passage information storage unit 1532b includes, for each history, a history ID, departure point information (departure point coordinate information / date / time information), destination information (destination coordinate information / date / time). Information), passing link information (link ID, passing direction of each link, link passing time of each link) related to the link that has passed from the departure point to the destination point is stored.
Further, the road passage information stored in the first road passage information storage unit is deleted when a predetermined period (for example, 3 hours) elapses after storage, and only the history of the predetermined period is retained.
For example, for the road passage information with the history ID “001” in the first road passage information storage unit shown in FIG. 3, the road starts from the start location Start1 and passes through the link a, link b, link c, link d, and link e, respectively Then, the fact that the destination Goal2 has been reached is stored. In addition, in association with the link IDs of the links a to e, the direction of passing through each link and the link passing time required to pass through each link are stored. For example, in the direction from the node n1 to the node n2 The fact that “5 minutes 30 seconds” was passed through the link a is stored.

  The ROM 154 has a program storage area composed of a non-volatile memory, and specifically includes a first storage program 154a, a first search program 154b, a first transmission program 154c, and the like.

The first storage program 154a counts, for example, the time required for the passage of the link on the passing road to the CPU 151 and the road passage information (the first passage time related to the time taken for the passage of the link of the time concerned) This is a program for realizing a function of storing (road passage information).
Specifically, when the vehicle C1 on which the first vehicle-mounted device M1 is mounted travels on the road, the CPU 151 passes through the link that the vehicle C1 has passed from the departure point to the destination. The link information (link ID, passage direction, link passage time) is stored in the first road passage information storage unit 1532b.
More specifically, the CPU 151 causes the RTC 152 to perform time measurement processing while the vehicle C1 is traveling, and the time at which the node n passes is counted by the RTC 152 every time the first vehicle-mounted device M1 passes through the node n. Remember. Then, when passing through two nodes n which are the end points of the link, it is determined that the link connecting these nodes has been passed, and the second node n is reached after leaving the first node n The time required to do this is calculated as the link passage time and stored in the first road passage information storage unit 1532b.

In addition, the CPU 151 deletes the road passage information in which a predetermined period (for example, 3 hours) has elapsed from the road passage information stored in the first road passage information storage unit 1532b, and only the history of the predetermined period is stored. Hold. Further, the CPU 151 stores only road passage information included in a predetermined range (for example, within a radius of 100 km) of the current position among the road passage information stored in the first road passage information storage unit 1532b. Road passage information not included in the predetermined range is deleted.
By executing the first storage program 154a, the CPU 151 functions as a timekeeping unit together with the RTC 152, and also functions as a first storage unit together with the first road passage information storage unit 1532b.

Here, with reference to FIG. 4, a description will be given of a road passing information storage process executed in the first vehicle-mounted device M1 when the vehicle C1 travels on a road.
In FIG. 4, it is assumed that the vehicle C1 is traveling on the lane A, starts from the node n1, travels on the links a to e, and arrives at the node n6. The opposite lane B is a lane facing the lane A.

For example, when the vehicle C1 departs from the node n1, the CPU 151 temporarily stores the time of departure from the node n1 measured by the RTC 152. When the vehicle C1 reaches the node n2, the CPU 151 temporarily stores the time when the vehicle C1 reaches the node n2 timed by the RTC 152, and determines that the link a between the node n1 and the node n2 has passed. The link passage time of link a is calculated, and the calculated link passage time is stored in the first road passage information storage unit 1532b together with the data such as the link ID and the passage direction.
Next, when the vehicle C1 reaches the node n3, the CPU 151 temporarily stores the time when the vehicle C1 reaches the node n3 measured by the RTC 152, and determines that the link b between the node n2 and the node n3 has passed. Then, the link passage time of the link b is calculated, and the calculated link passage time is stored in the first road passage information storage unit 1532b together with the data such as the link ID and the passage direction.
Furthermore, when the vehicle C1 reaches the node n4, the node n5, and the node n6, the CPU 151 determines that the links c to e have been passed at the points that have reached the nodes n4 to n5, and the link passing time of each link is determined. Calculate and store in the first road passage information storage unit 1532b.

The first search program 154b is a program for causing the CPU 151 to realize a function of searching for the second vehicle-mounted device M2 that can communicate with the first vehicle-mounted device M1, for example.
Specifically, the CPU 151 searches for a communicable second vehicle-mounted device M2 mounted on the vehicle C2 that is traveling in a direction opposite to the host vehicle C1. For example, when the second vehicle-mounted device M2 exists in the communication range, a process of establishing a wireless link with the second vehicle-mounted device M2 is performed.
The CPU 151 functions as first search means (search means) by executing the first search program 154b.

The first transmission program 154c is, for example, the road passing information stored in the CPU 151 by the execution of the first storage program 154a for the second vehicle-mounted device M2 searched for by the execution of the first search program 154b. This is a program for realizing a function of wirelessly transmitting (first road passage information).
Specifically, the CPU 151 wirelessly transmits the road passage information stored in the first road passage information storage unit 1532b to the second vehicle-mounted device M2 that exists within the communication range and has a wireless link established. Transmitted by the communication unit 12.
The CPU 151 functions as a first transmission unit (transmission unit) by executing the first transmission program 154c.

Here, with reference to FIG. 5, a description will be given of a transmission / reception process of road passage information executed between the first vehicle-mounted device M1 and the second vehicle-mounted device M2 when the vehicle C1 passes the vehicle C2.
In FIG. 5, the vehicle C1 is traveling on the lane A of the link e, for example. Further, the vehicle C1 has already passed the links a to d, and the link passage time required for the passage of each link a to d is stored in the first road passage information storage unit 1532b of the vehicle C1. Shall.

  The vehicle C1 searches for a communicable second vehicle-mounted device M2 mounted on the vehicle C2 that is traveling in a direction opposite to the host vehicle C2. For example, as shown in FIG. 5, when it is determined that a second vehicle-mounted device M <b> 2 that can communicate with the vehicle C <b> 2 that travels on the opposite lane B while searching for the link e is searched for, the second vehicle-mounted device 2. A wireless link is established with the device M2. Then, the wireless communication unit 12 wirelessly transmits the road passage information stored in the first road passage information storage unit 1532b to the second vehicle-mounted device M2 that has established the wireless link. That is, the second vehicle-mounted device M2 acquires road passage information including the link passage time of the links (links a to d) that the vehicle C1 has passed in the past.

(Second on-board unit)
Next, the configuration of the main part of the second vehicle-mounted device M2 mounted on the vehicle C2 will be described with reference to FIG. In the configuration of the second vehicle-mounted device M2, the detailed description of the configuration of the same part as the first vehicle-mounted device M1 is omitted.
As shown in FIG. 6, the second vehicle-mounted device M2 includes, for example, a current position detection unit 21, a first reception unit, a wireless communication unit 22 as a second transmission unit, a display unit 23, An input unit 24, a control unit 25, and the like are provided.

  The control unit 25 includes a CPU 251, an RTC 252, a memory unit 253, a ROM 254, and the like.

  The CPU 251 executes various programs stored in the ROM 254 according to input signals input from the respective units of the second vehicle-mounted device M2, and outputs output signals to the respective units based on the execution programs. The overall operation of the second vehicle-mounted device M2 is comprehensively controlled.

  The memory unit 253 includes, for example, a work area 2531 composed of a volatile memory such as a RAM and a data area 2532 composed of a nonvolatile memory such as an EPROM. The data area 2532 stores, for example, a map information DB 2532a, a second road passage information storage unit 2532b as a second storage unit, and the like.

  The second road passage information storage unit 2532b stores road passage information related to the link passage time of the link through which the vehicle C2 has passed, and is received from the first vehicle-mounted device M1 in the execution of the second storage program 254b described later. Updated based on the road passing information.

  The ROM 254 has a program storage area composed of a non-volatile memory. Specifically, the first reception program 254a, the second storage program 254b, the second search program 254c, the second transmission program 254d, and the like. It has.

The first reception program 254a is, for example, a program for causing the CPU 251 to realize a function of receiving road passage information wirelessly transmitted from the first vehicle-mounted device M1.
Specifically, the CPU 251 wirelessly transmits road passage information including a link passage time of a link through which the vehicle C1 has passed in the past from the first vehicle-mounted device M1 mounted on the vehicle C1 existing within the communication range. Then, the wireless communication unit 22 receives the road passage information.
The CPU 251 functions as a first receiving unit together with the wireless communication unit 22 by executing the first receiving program 254a.

For example, the second storage program 254b is a program for causing the CPU 251 to realize a function of storing road passage information received by the execution of the first reception program 254a.
Specifically, the CPU 251 updates the road passage information stored in the second road passage information storage unit 2532b based on the road passage information received by the wireless communication unit 22. In other words, if the road passage information received from the first vehicle-mounted device M1 includes the link passage time of a link that is not stored in the second road passage information storage unit 2532b, the CPU 251 converts this information into the first. 2 in the road passage information storage unit 2532b. Further, when the road passage information received from the first vehicle-mounted device M1 includes the link passage time of the link stored in the second road passage information storage unit 2532b, based on the latest data. Update.

In addition, the CPU 251 deletes road passage information in which a predetermined period (for example, 3 hours) has elapsed from the road passage information stored in the second road passage information storage unit 2532b, and records only the history of the predetermined period. Hold. Further, the CPU 251 stores only the road passage information included in the predetermined range (for example, within a radius of 100 km) of the current position among the road passage information stored in the second road passage information storage unit 2532b. Road passage information not included in the predetermined range is deleted.
The CPU 251 functions as a second storage unit together with the second road passage information storage unit 2532b by executing the second storage program 254b.

The second search program 254c is, for example, a program for causing the CPU 251 to realize a function of searching for the third vehicle-mounted device M3 that can communicate with the second vehicle-mounted device M2.
Specifically, the CPU 251 is traveling in the same direction as the vehicle C1 on which the first vehicle-mounted device M1 is mounted, and the communicable third mounted on the vehicle C3 traveling behind the vehicle C1. The on-vehicle device M3 is searched. And if the 3rd onboard equipment M3 exists in a communication range, the process which establishes a radio link with the said 3rd onboard equipment M3 will be performed.
The CPU 251 functions as a second search unit by executing the second search program 254c.

The second transmission program 254d is, for example, the road passing information stored in the CPU 251 by the execution of the second storage program 254b for the third vehicle-mounted device M3 searched for by the execution of the second search program 254c. Is a program for realizing the function of wirelessly transmitting a message.
Specifically, the CPU 251 wirelessly transmits the road passage information stored in the second road passage information storage unit 2532b to the third vehicle-mounted device M3 that exists within the communication range and has a wireless link established. Transmitted by the communication unit 22.
The CPU 251 functions as a second transmission unit together with the wireless communication unit 22 by executing the second transmission program 254d.

Here, referring to FIG. 7, when the vehicle C2 passes by the vehicle C3 traveling in the same direction as the vehicle C1 that has passed in the past, it is executed between the second vehicle-mounted device M2 and the third vehicle-mounted device M3. The transmission / reception processing of road passage information to be performed will be described.
In FIG. 7, the vehicle C2 is traveling on the opposite lane B of the link a, for example. As described above, when the second vehicle-mounted device M2 mounted on the vehicle C2 passes the vehicle C1 while traveling on the opposite lane B of the link e, the first vehicle-mounted device M1 mounted on the vehicle C1. The second road passage information storage unit 2532b has been updated based on the road passage information transmitted from. That is, the second road passage information storage unit 2532b stores the link passage time required for the passage of the links (links a to d) through which the vehicle C1 mounted with the first vehicle-mounted device M1 has passed in the past. .

The vehicle C2 has a communicable third vehicle-mounted device M3 mounted on the vehicle C3 traveling in the same direction as the vehicle C1 on which the first vehicle-mounted device M1 serving as a transmission terminal is mounted during traveling. Explore. For example, as shown in FIG. 7, when it is determined that a third vehicle-mounted device M <b> 3 that can communicate with the vehicle C <b> 3 that travels on the lane A while traveling on the link a has been searched, the third vehicle-mounted device is connected. A wireless link is established with M3. Then, the wireless communication unit 22 wirelessly transmits the road passage information stored in the second road passage information storage unit 2532b to the third vehicle-mounted device M3 that has established the wireless link.
Therefore, the third vehicle-mounted device M3 uses the road passage information including the link passage time required for the passage of the links (links a to d) that the vehicle C1 as the transmission terminal has passed in the past, as the second relay station. It will be acquired via the vehicle-mounted device M2.

(Third onboard equipment)
Next, the configuration of the main part of the third vehicle-mounted device M3 mounted on the vehicle C3 will be described with reference to FIG. In the configuration of the third vehicle-mounted device M3, detailed description of the configuration of the same part as the first vehicle-mounted device M1 or the second vehicle-mounted device M2 is omitted.
As shown in FIG. 8, the third vehicle-mounted device M3 includes, for example, a current position detection unit 31, a wireless communication unit 32 as a second receiving unit, a display unit 33, an input unit 34, and a control unit in the apparatus main body. 35 etc. are comprised.

  The control unit 35 includes a CPU 351, an RTC 352, a memory unit 353, a ROM 354, and the like.

  The CPU 351 executes various programs stored in the ROM 354 in accordance with input signals input from the respective units of the third vehicle-mounted device M3, and outputs output signals to the respective units based on the execution programs. The overall operation of the third vehicle-mounted device M3 is comprehensively controlled.

  The memory unit 353 includes, for example, a work area 3531 made of a volatile memory such as a RAM and a data area 3532 made of a nonvolatile memory such as an EPROM. The data area 3532 stores, for example, a map information DB 3532a, a third road passage information storage unit 3532b serving as a third storage unit, and the like.

  The third road passage information storage unit 3532b stores road passage information related to the link passage time of the link through which the vehicle C3 has passed, and is received from the second vehicle-mounted device M2 in the execution of the third storage program 354b described later. Updated based on the road passing information.

  The ROM 354 has a program storage area composed of a non-volatile memory. Specifically, the second reception program 354a, the third storage program 354b, the current position detection program 354c, the route search program 354d, and the provision program 354e. Etc.

For example, the second reception program 354a is a program for causing the CPU 351 to realize a function of receiving road passage information (second road passage information) wirelessly transmitted from the second vehicle-mounted device M2.
Specifically, the CPU 351 starts from the second vehicle-mounted device M2 mounted on the vehicle C2 existing within the communication range, the link passage time of the link that the vehicle C2 has passed in the past, and the first vehicle-mounted device M1. When the road passage information updated based on the link passage time included in the transmitted road passage information is wirelessly transmitted, the wireless communication unit 32 receives the road passage information.
The CPU 351 functions as a second receiving unit (receiving unit) together with the wireless communication unit 32 by executing the second receiving program 354a.

The third storage program 354b is a program for causing the CPU 351 to realize a function of storing road passage information (second road passage information) received by the execution of the second reception program 354a, for example.
Specifically, the CPU 351 updates the road passage information stored in the third road passage information storage unit 3532b based on the road passage information received by the wireless communication unit 32. That is, when the road passage information received from the second vehicle-mounted device M2 includes the link passage time of a link that is not stored in the third road passage information storage unit 3532b, the CPU 351 converts the road passage information into the first information. 3 in the road passage information storage unit 3532b. Further, when the road passage information received from the second vehicle-mounted device M2 includes the link passage time of the link stored in the third road passage information storage unit 3532b, based on the latest data. Update.
The road passing information received from the second vehicle-mounted device M2 is transmitted by the wireless communication network when the vehicle C1 equipped with the second vehicle-mounted device M2 passes the vehicle C1 equipped with the first vehicle-mounted device M1. Updated based on the road passing information. The vehicle C3 is a vehicle that travels in the same direction after the vehicle C1. Therefore, the latest link passage time data relating to a link that is likely to travel after the vehicle C3 is stored in the road passage information storage unit.

In addition, the CPU 351 deletes road passage information in which a predetermined period (for example, 3 hours) has elapsed from the road passage information stored in the third road passage information storage unit 3532b, and only records the history of the predetermined period. Hold. Furthermore, the CPU 351 stores only road passage information included in a predetermined range (for example, within a radius of 100 km) of the current position among the road passage information stored in the third road passage information storage unit 3532b. Road passage information not included in the predetermined range is deleted. As a result, only useful road passage information is held in the third road passage information storage unit 3532b.
The CPU 351 functions as a third storage unit (second storage unit) together with the third road passage information storage unit 3532b by executing the third storage program 354b.

The current position detection program 354c is a program for causing the CPU 351 to realize a function of detecting the current position, for example.
Specifically, the CPU 351 causes the current position detection unit 31 configured by a GPS positioning unit or the like to acquire the current position information of the third vehicle-mounted device M3 itself, and the current position output from the current position detection unit 31 Based on the detection signal, the coordinates (latitude / longitude) as the current position of the third vehicle-mounted device M3 are specified. Further, map matching processing is performed based on the specified current position, and the road where the vehicle on which the third vehicle-mounted device M3 is mounted is located is stored in a predetermined area such as the data area 3532 or the like. Specify based on data (not shown). The map matching process includes, for example, pattern matching that obtains a road that is a candidate for matching according to the traveling locus of the vehicle, identifies the road with the highest correlation from the matching candidate, and matches the current position on the road. Use.
The CPU 351 functions as a current position detection unit together with the current position detection unit 31 by executing the current position detection program 354c.

  The route search program 354d executes the current position detection program 354c using, for example, the time required for the passage of a predetermined section of the road included in the road passage information stored in the CPU 351 by the execution of the third storage program 354b. This is a program for realizing a function of searching for a guide route that requires the shortest time required from the current position detected to the destination. Further, the route search program 354d re-searches for a guide route that takes the shortest time to the destination every time road passage information is stored by executing the third storage program 354b.

Specifically, the CPU 351 calculates the time required for all routes from the current position (departure point) detected by the current position detection unit 31 to the destination. As the required time, the link passage time of the link included in the road passage information stored in the third road passage information storage unit 3532b is preferentially used, and the link passage time is stored in the third road passage information storage unit 3532b. About the link which is not memorize | stored, it calculates by using the average passage time contained in the link information of map information DB3532a. Then, among the candidate routes, the route that takes the shortest time to the calculated destination is determined as the guidance route to be provided to the user.
The CPU 351 executes such route search processing every time the third road passage information storage unit 3532b is updated based on the road passage information received from the second vehicle-mounted device M2. That is, every time the CPU 351 receives the road passing information stored in the vehicle C1 traveling ahead of the host vehicle C3 via the vehicle C2 as a relay station, the time required from the current position to the destination is the shortest. Search the guide route again.
Therefore, in the vehicle C3, the road condition of the destination can be grasped in real time and more accurately, and based on the actual time required when another vehicle C1 actually passes the destination road. Thus, the guide route is searched. Therefore, it becomes possible to reach the destination more reliably in the shortest time.
The CPU 351 functions as a route search unit by executing the route search program 354d.

Here, the route search process executed in the third vehicle-mounted device M3 will be described with reference to FIG.
In FIG. 7, the third vehicle-mounted device M3 mounted on the vehicle C3 travels along the guide route that is searched in advance and arrives at the shortest distance to the destination. This guide route is, for example, a route passing through link a → link b → link c → link d → link e with the node n6 as the destination. The required time to the node n6 as the destination is calculated as “20 minutes 30 seconds” based on the average passing time of the link information included in the map information, for example.

As shown in FIG. 7, when the vehicle C3 passes the vehicle C2 traveling on the opposite lane B while traveling on the link a, and the wireless link is established between the vehicle C3 and the vehicle C2, as described above, The third vehicle-mounted device M3 receives the road passing information transmitted from the second vehicle-mounted device M2 via the wireless communication network. The road passing information is road passing information transmitted from a passing vehicle C1 while the vehicle C2 is traveling on the link e (see FIG. 5), and the link on which the vehicle C3 is scheduled to travel (link b, link c, It includes the link transit time of link d). The CPU 351 of the third vehicle-mounted device M3 updates the third road passage information storage unit 3532b based on the road passage information received from the second vehicle-mounted device M2.
Further, when the third road passage information storage unit 3532b is updated, the CPU 351 has the shortest time required to reach the destination based on the updated road passage information in the third road passage information storage unit 3532b. Re-search the guidance route. For example, the link (for example, link c) included in the guide route searched in advance is congested, and the route including the congested link (link a → link b → link c → link d → link e) is passed. Route) is calculated as “51 minutes 05 seconds”, and on the other hand, a route not including a congested link (for example, a route passing through link a → link b → link j → link k → link e) Is calculated as “20 minutes 10 seconds”. Then, the CPU 351 changes the guide route provided to the user to a route with a shorter required time (a route passing through link a → link b → link j → link k → link e).
Therefore, as described above, even if the roads included in the guide route that have been searched in advance and reach the destination in the shortest time are congested and cannot reach the destination in the shortest time. Because the guide route that arrives at the destination in the shortest time according to the current road conditions is searched again, it is possible to bypass the congested road and reach the destination more reliably in the shortest time .

The provided program 354e is a program for causing the CPU 351 to realize a function of providing route guidance information related to the guidance route searched by executing the route search program 354d, for example.
Specifically, when the guide route is searched by executing the above-described route search program 354d, the CPU 351 reads out map information including the current position and the searched guide route from the map information DB 3532a. Then, a mark is displayed at the current position of the vehicle C3 on the map, and an arrow or the like is displayed on the searched guidance route, and this map information is displayed as route guidance information together with data such as required time to the destination. 33, the user is notified of the route to travel and the required time. Further, when providing the route guidance information related to the guidance route, the CPU 351 displays the required time to the destination on the guidance route on the display unit 33 to notify the user. Further, route guidance information by voice guidance may be provided along with the traveling of the vehicle.
In addition, when the route search program 354d executes the route search program 354d and a new guide route that takes the shortest time to the destination is newly searched again, the CPU 351 displays map information including the current position and the searched route again as map information. Read from the information DB 3532a. Then, as shown in FIG. 9, the display unit 33 is displayed to notify the user that the guidance route has been changed. In addition, a mark is displayed at the current position of the vehicle C3 on the map, and an arrow or the like is displayed on the changed guidance route. This map information is displayed as route guidance information together with data such as a required time to the destination. 33, the user is notified of the changed guide route and the required time.
Further, even when the guide route is not changed, the CPU 351 updates the third road passage information storage unit 3532b based on the road passage information received from the other vehicle-mounted device M, and the required route to the destination. When the time is changed, the changed required time is displayed on the display unit 33 to notify the user.
The CPU 351 functions as a providing unit by executing the providing program 354e.

  Next, a transmission / reception process of road passage information performed between the first vehicle-mounted device M1 and the second vehicle-mounted device M2 will be described with reference to the flowchart of FIG.

  First, in step S1, the CPU 151 of the first vehicle-mounted device M1 causes the RTC 152 to measure the link passage time each time the first vehicle-mounted device M1 passes through the link, and the measured link passage time is used as the road passage information. Is stored in the first road passage information storage unit 1532b. In step S <b> 2, the CPU 151 includes the road passage information stored in the first road passage information storage unit 1532 b, the road passage information that has passed a predetermined period after storage, and the current position detected by the current position detection unit 11. The road passing information outside the predetermined range is deleted. In step S3, it is determined whether or not there is a second vehicle-mounted device M2 that is traveling on the opposite lane B and can communicate. When CPU 151 determines in step S3 that there is no communicable second vehicle-mounted device M2 (step S3; No), it returns to step S1 and repeats the above processing. On the other hand, if CPU151 judges that the 2nd onboard equipment M2 which can communicate exists (step S2; Yes), a wireless link will be established between the 2nd onboard equipment M2 in step S4. In step S5, the road passage information stored in the first road passage information storage unit 1532b is transmitted to the second vehicle-mounted device M2 via the wireless communication network, and this process is terminated.

  On the other hand, in step 6, the CPU 251 of the second vehicle-mounted device M2 updates the second road passage information storage unit 2532b based on the road passage information received from the first vehicle-mounted device M1. In step S7, among the road passage information stored in the second road passage information storage unit 2532b, the road passage information that has passed a predetermined period after storage and the predetermined current position detected by the current position detection unit 21 are stored. The road passing information outside the range is deleted, and this process is terminated.

  Next, a transmission / reception process of road passage information performed between the second vehicle-mounted device M2 and the third vehicle-mounted device M3 will be described with reference to the flowchart of FIG.

  First, in step S11, the CPU 251 of the second vehicle-mounted device M2 is traveling in the lane A, and there is a third vehicle-mounted device M3 that can communicate in the same direction as the first vehicle-mounted device M1. Judging. When CPU 251 determines in step S11 that there is no communicable third vehicle-mounted device M3 (step S11; No), it returns to step S11 and repeats the above processing. On the other hand, when the CPU 251 determines that there is a communicable third vehicle-mounted device M3 (step S11; Yes), in step S12, the CPU 251 establishes a wireless link with the third vehicle-mounted device M3. In step S13, the road passage information stored in the second road passage information storage unit 2532b is transmitted to the third vehicle-mounted device M3 via the wireless communication network, and this process is terminated.

  On the other hand, the CPU 351 of the third vehicle-mounted device M3 updates the third road passage information storage unit 3532b based on the road passage information received from the second vehicle-mounted device M2 in step S14. In step S15, among the road passage information stored in the third road passage information storage unit 3532b, the road passage information after a predetermined period of time has passed and the current position detected by the current position detection unit 31 are determined. Delete road passage information that is out of range. Next, in step S16, the CPU 351 determines the required time from the current position to the destination based on the link passage time included in the updated third road passage information storage unit 3532b, link information included in the map information, and the like. Is searched for the shortest guide route (or re-search if a guide route has already been searched). In step S17, the CPU 351 provides route guidance information related to the guidance route searched (or re-searched) in step S16, and the process ends.

According to the information exchange system 100 in the present embodiment described above, in the first vehicle-mounted device M1, by executing the first storage program 154a, the time required for passing a predetermined section on the passing road is timed and timed. The road passage information relating to the time required for passing through the predetermined section of the road is stored, and by executing the first search program 154b, the second vehicle-mounted device M2 that can communicate with the first vehicle-mounted device M1 is searched. Then, by the execution of the first transmission program 154c, the road passage information stored by the execution of the first storage program 154a is stored in the second vehicle-mounted device M2 searched for by the execution of the first search program 154b. Wirelessly transmitted.
Further, in the second vehicle-mounted device M2, road passage information wirelessly transmitted from the first vehicle-mounted device M1 is received by the execution of the first reception program 254a, and the first search program 254b executes the first The road passage information received by the execution of the reception program 254a is stored, and the execution of the second search program 254c searches for the third vehicle-mounted device M3 that can communicate with the second vehicle-mounted device M2. By executing the transmission program 254d, the road passage information stored by the execution of the second storage program 254b is wirelessly transmitted to the third vehicle-mounted device M3 searched for by the execution of the second search program 254c. .
In addition, in the third vehicle-mounted device M3 mounted on the vehicle heading in the same direction as the vehicle on which the first vehicle-mounted device M1 is mounted, wireless transmission is performed from the second vehicle-mounted device M2 by executing the second reception program 354a. The received road passage information is received, the road passage information received by the execution of the second reception program 354a is stored by the execution of the third storage program 354b, and the current position is determined by the execution of the current position detection program 354c. Execution of the current position detection program 354c using the time required for the passage of a predetermined section of the road detected and executed by the route search program 354d and included in the road passage information stored by the execution of the third storage program 354b The guide route with the shortest required time from the current position detected to the destination to the destination is searched, and the providing program 35 The execution of e provides route guidance information related to the guidance route searched for by the execution of the route search program 354d, and the road storage information is stored by the execution of the third storage program 354b by the execution of the route search program 354d. In addition, the guide route that takes the shortest time to the destination is searched again.

Therefore, in the information exchange system 100 that exchanges information by wireless communication between vehicles, it is possible to provide optimal route guidance information that is more suitable for actual road conditions based on information acquired from other vehicles C. . That is, in the first vehicle-mounted device M1, the road-passing information related to the time required to pass through the predetermined section on the road that has passed in the past is relayed through the second vehicle-mounted device M2, and the first vehicle-mounted device M1 is mounted. It is transmitted to the third vehicle-mounted device M3 mounted on the vehicle C3 heading in the same direction as the vehicle C1. Then, every time the third vehicle-mounted device M3 is transmitted from the first vehicle-mounted device M1 through the second vehicle-mounted device M2, it is included in the road passing information transmitted from the first vehicle-mounted device M1. Based on the time required for passing through a predetermined section of the road, a guide route with the shortest required time to the destination is searched. Therefore, in the third vehicle-mounted device M3, the road condition of the destination can be grasped in real time and more accurately, and the vehicle C1 in which the other first on-vehicle device M1 is mounted on the road of the destination. The guide route is searched based on the actual time required when the vehicle actually passes.
For example, even if a pre-searched road that is included in the guide route that reaches the destination in the shortest time is congested and can no longer reach the destination in the shortest time, the road at that time The guide route that arrives at the destination in the shortest time according to the situation is searched again, and it is possible to travel around the congested road. Therefore, it becomes possible to reach the destination more reliably in the shortest time.

  The present invention is not limited to the above embodiment, and various improvements and design changes may be made without departing from the spirit of the present invention.

  For example, storage media such as a map information DB and a road passage information storage unit are optical, magnetic, semiconductor such as a hard disk (Hard Disc), a CD-ROM (Compact Disc Read Only Memory), a DVD (Digital Versatile Disc), etc. Any storage medium such as a memory may be used. Further, it may be fixed (for example, magnetic tape, hard disk, etc.) or detachably provided (for example, FD, MO, DVD, etc.).

Further, the vehicle-mounted device M as the relay station is not limited to the vehicle-mounted device M mounted on the vehicle C traveling in the lane facing the vehicle-mounted device M as the transmission terminal / reception terminal, and the vehicle-mounted device as the transmission terminal / reception terminal. The vehicle-mounted device M mounted on the vehicle C traveling in the same direction with the same lane as the device M may be used.
Information may be transmitted using a plurality of vehicle-mounted devices M as relay stations.
Further, when the first vehicle-mounted device M1 can communicate with the third vehicle-mounted device M3, the vehicle directly passes through the road with respect to the third vehicle-mounted device M3 without relaying the second vehicle-mounted device M2. Information may be sent.
The third vehicle-mounted device M3 as a receiving terminal is not limited to the vehicle-mounted device M mounted on a vehicle that is traveling in the same direction with the same lane as the first vehicle-mounted device M1 as a transmitting terminal. The first vehicle-mounted device M1 may be mounted on a vehicle that is traveling in a lane facing the first vehicle-mounted device M1.

The third vehicle-mounted device M3 may be configured to present a plurality of guide routes and allow the user to select a desired guide route.
Further, when a new guide route having a shorter required time to the destination than the already determined guide route is searched, the user may select whether to change the guide route.
In addition, when the required time to the destination in the already determined guide route is changed, the user is allowed to select whether or not to re-search the guide route, and the user re-searches the guide route. The configuration may be such that re-searching is performed only when selection is made.

The first storage means, the second storage means, and the third storage means include a direction from the current position to the destination among the road passage information stored in the first to third road passage information storage units. The configuration may be such that road passage information of links existing in the opposite direction is deleted.
The first storage means, the second storage means, and the third storage means store link passage time data of each link for each predetermined time zone (for example, in units of two hours), and guide routes It may be configured to use road passage information according to the time zone at the time of the search.

  Moreover, you may comprise the 1st onboard equipment M1 used as a transmission terminal to transmit only the road passage information which the 3rd onboard equipment M3 used as a receiving terminal requires. That is, for example, first, information indicating necessary road passage information (for example, information on a destination, information on a guidance route, etc.) is transmitted from the third vehicle-mounted device M3 to the first vehicle-mounted device M1. And in the 1st onboard equipment M1, based on the information received from the 3rd onboard equipment M3, road passage information (for example, in the predetermined range of the destination) with high possibility of being used in the 3rd onboard equipment M3. You may comprise so that only the road passing information of the link included) may be transmitted with respect to the 3rd vehicle equipment M3.

  Further, the second on-vehicle device M2 as the relay station holds the second road passage information storage unit 2532b as it is without updating it based on the road passage information received from the first on-vehicle device M1 as the transmission terminal. And after transmitting the road passage information received from the said 1st onboard equipment M1 to the 3rd onboard equipment M3 as a receiving terminal, the structure which deletes the said road passage information may be sufficient.

  Further, the predetermined section on the road is not limited to the link between the nodes, and may be any unit for dividing the road. For example, it may be a national road, a general road, or the like, or a section between two exits on a national highway.

It is a figure which illustrates the whole structure of the information exchange system in this embodiment. It is a figure which illustrates the principal part structure of a 1st onboard equipment. It is a figure which illustrates the 1st road passage information storage part. It is a figure for demonstrating the memory | storage process of the road passage information performed in a 1st onboard equipment. It is a figure for demonstrating the transmission / reception process of the road passage information performed between a 1st onboard equipment and a 2nd onboard equipment. It is a figure which illustrates the principal part structure of a 2nd vehicle equipment. It is a figure for demonstrating the transmission / reception process of the road passage information performed between a 2nd onboard equipment and a 3rd onboard equipment. It is a figure which illustrates the principal part structure of a 3rd vehicle equipment. It is an example of the route guidance information regarding the re-searched guidance route displayed on the display unit. It is a flowchart which illustrates the transmission / reception process of the road passage information performed between a 1st onboard equipment and a 2nd onboard equipment. It is a flowchart which illustrates the transmission / reception process of the road passage information performed between a 2nd onboard equipment and a 3rd onboard equipment.

Explanation of symbols

100 Information exchange system M1 1st onboard equipment 12 Wireless communication part (1st transmission means, transmission means)
152 RTC (Timekeeping means)
1532b First road passage information storage unit (first storage means)
151 CPU (time measuring means, first storage means, first search means, search means, first transmission means, transmission means)
154a First storage program (time measuring means, first storage means)
154b First search program (first search means, search means)
154c First transmission program (first transmission means, transmission means)
M2 Second vehicle-mounted device 22 Wireless communication unit (first receiving means, second transmitting means)
2532b Second road passage information storage unit (second storage means)
251 CPU (first reception means, second storage means, second search means, second transmission means)
2532b Second road passage information storage unit (second storage means)
254a First receiving program (first receiving means)
254b Second storage program (second storage means)
254c Second search program (second search means)
254d Second transmission program (second transmission means)
M3 3rd onboard equipment (1st onboard equipment)
32 Wireless communication unit (second receiving means)
351 CPU (second receiving means, receiving means, third storing means)
3532b Third road passage information storage unit (third storage means, second storage means)
354a Second receiving program (second receiving means, receiving means)
354b Third storage program (third storage means, second storage means)
354c Current position detection program (current position detection means)
354d Route search program (route search means)
354e Provided program (providing means)

Claims (3)

In an information exchange system for exchanging information between in-vehicle devices mounted on multiple vehicles,
The first vehicle-mounted device
A time measuring means for measuring the time required for the passage of a predetermined section on the passing road;
First storage means for storing first road passage information relating to a time required to pass through a predetermined section of the road timed by the time measuring means;
Search means for searching for a second on-vehicle device capable of communication;
Transmitting means for wirelessly transmitting the first road passage information stored by the first storage means to a second vehicle-mounted device searched by the search means;
Receiving means for receiving second road passage information wirelessly transmitted from the second vehicle-mounted device;
Second storage means for storing the second road passage information received by the receiving means;
Current position detecting means for detecting the current position;
Using the time required to pass through a predetermined section of the road included in the second road passage information stored in the second storage means, the current position detected by the current position detection means to the destination Route search means for searching for a guide route with the shortest required time;
Providing means for providing route guidance information related to the guidance route searched by the route search means;
An information exchange system comprising:   The route search means re-searches for the guide route having the shortest required time to the destination each time the second road passage information is stored by the second storage means. Item 4. The information exchange system according to Item 1. In an information exchange system for exchanging information between in-vehicle devices mounted on multiple vehicles,
The first vehicle-mounted device
A time measuring means for measuring the time required for the passage of a predetermined section on the passing road;
First storage means for storing road passage information relating to the time required for the passage of the predetermined section of the road timed by the time measuring means;
First search means for searching for a second on-vehicle device capable of communicating with the first on-vehicle device;
First transmission means for wirelessly transmitting the road passage information stored by the first storage means to the second vehicle-mounted device searched by the first search means;
The second vehicle-mounted device is:
First receiving means for receiving road passage information wirelessly transmitted from the first vehicle-mounted device;
Second storage means for storing the road passage information received by the first receiving means;
Second search means for searching for a third on-vehicle device capable of communicating with the second on-vehicle device;
A second transmission means for wirelessly transmitting the road passage information stored by the second storage means to the third vehicle-mounted device searched by the second search means;
The third vehicle-mounted device is:
Mounted on a vehicle heading in the same direction as the vehicle on which the first vehicle-mounted device is mounted;
Second receiving means for receiving the road passage information wirelessly transmitted from the second vehicle-mounted device;
Third storage means for storing the road passage information received by the second receiving means;
Current position detecting means for detecting the current position;
The required time from the current position detected by the current position detecting means to the destination is calculated using the time required for the passage of a predetermined section of the road included in the road passing information stored in the third storage means. Route search means for searching for the shortest guide route;
Providing means for providing route guidance information related to the guidance route searched by the route search means;
With
The route search means includes
Each time the road passing information is stored in the third storage means, the information exchange system is searched again for the guide route that takes the shortest time to the destination.

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