JPH08313285A - On-vehicle apparatus for recommending route - Google Patents

Abstract

PURPOSE: To provide a recommended route reflecting an actual traffic condition even when an unassigned link is present. CONSTITUTION: In an on-vehicle navigation apparatus, when a congestion degree associated with an external link is received from a road beacon, the congestion degree is related to an internal link corresponding to the external link. A weighting coefficient corresponding to a congestion degree is weighted to a link cost of the internal link having the congestion degree related thereto, thereby to change the link cost (S12-S17). In the meantime, an expected value of the weighting coefficient is weighted to a link cost of an internal link (unassigned link) to which the congestion degree is not related because of the absence of a corresponding external link or some other reason, thereby to change the link cost (S18). As a result of this, the link cost of the unassigned link can reflect an actual traffic condition. The changed link cost is utilized to obtain a recommended route.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to, for example, a vehicle-mounted navigation device, receives road traffic information transmitted from an external communication device, obtains a route in which the road traffic information is taken into account, and provides the driver with the route. The present invention relates to an in-vehicle route providing device provided.

[0002]

2. Description of the Related Art Conventionally, in-vehicle navigation devices that display the current location of a vehicle together with a road map around the vehicle have been used in order to support the traveling of the vehicle on an unfamiliar land. In such an in-vehicle navigation device, a driver or a passenger (hereinafter collectively referred to as "driver") can set a destination, and a computer automatically recommends a recommended route between the present location and the set destination. (See Japanese Patent Laid-Open No. 5-53504).

In a vehicle-mounted navigation device to which the route providing function is added, when a destination is set, a link connecting road intersections and the like prepared in the vehicle-mounted navigation device (hereinafter referred to as "internal link"). The road map data of which is a structural unit is read out, and the tree of the internal link of the area including the present location and the destination is searched. At this time,
The link cost of each internal link included in the road map data is sequentially added, and the route that reaches the destination at the minimum link cost is set as the recommended route.

By the way, the link cost required to acquire the recommended route actually changes from moment to moment depending on traffic conditions such as traffic congestion on the road and traffic restrictions due to road construction and accidents. On the other hand, it is impossible for the vehicle side to prepare in advance a link cost that reflects a traffic condition that changes from moment to moment.
Therefore, the vehicle-mounted navigation device can acquire only the recommended route that does not reflect the actual traffic situation which changes from moment to moment.

Therefore, in recent years, a system for transmitting the latest road traffic information from an external communication device to a vehicle has been studied for practical use. For example, as a concrete example of a system currently under consideration, a road traffic information communication system (VICS: Vehicle Info) that transmits road traffic information to a vehicle by using a radio wave beacon, an optical beacon or FM multiplex broadcasting.
rmation and Communication System), and cars /
A traffic information service (ATIS: Advanced Traffic Inf) that transmits road traffic information to vehicles using a mobile phone network.
ormation Service).

In such a system, road traffic information is transmitted in association with each link (hereinafter referred to as "external link") that constitutes a route network created on the system side. Specifically, for example, when traffic congestion information is considered as road traffic information, the traffic congestion degree according to the vehicle speed actually measured on the system side is transmitted. The congestion level is, for example, on a general national road, when the vehicle speed is 10 (Km / h) or more and 20 (Km / h).
If it is less than h), it is "1", and if the speed of the vehicle is less than 10 (Km / h), it is "2".

On the other hand, on the vehicle side, when the congestion degree is received, the link cost is changed based on the congestion degree.
Specifically, first, the correspondence table prepared in the in-vehicle navigation device is referred to, and the congestion degree is associated with the internal link corresponding to the external link with which the congestion degree is associated. As a result, each internal link is given a weighting coefficient according to the degree of congestion. Then, the link cost of the internal link is weighted with the weighting factor. For example,
In an internal link with an average speed of 60 (Km / h) that constitutes a general national highway, the degree of congestion is such that the average speed of the vehicle is 10 (Km / h) or more and 20 (Km / h)
If it is "1" that indicates less than, the weighting factor is set to "4" based on the calculation of 60 ÷ 15 = 4 (15 is an intermediate value between 10 and 20), and the normal link cost when there is no traffic congestion is 4 Double. Then, the recommended route is acquired using the changed link cost.

[0008]

However, in a vehicle-mounted navigation device using the above system, a route network having an external link created on the system side as a unit is an internal link provided on the vehicle side as a unit. Since it is made coarser than the route network, there are internal links that have no corresponding external links.
Therefore, the congestion level cannot be associated with the internal link. Here, the reason why the route network having the external link as a structural unit becomes coarse is that there are restrictions on communication capacity, communication time, processing time, and the like.

Further, even when the system side cannot determine the degree of congestion due to a failure of the vehicle detector or the like, the degree of congestion cannot be associated with the internal link.
Therefore, in the above case, it is not possible to change the link cost of the internal link (hereinafter referred to as “non-allocation link”) that is not associated with the congestion degree. Therefore, the unallocated link is excluded from the links for which the recommended route is calculated, or the recommended route is acquired by assuming that there is no congestion (weighting factor = 1). As a result, it was not always possible to completely reflect the actual traffic conditions on the recommended route.

On the other hand, in the vehicle-mounted navigation device, as described above, the link costs of the internal links having weighting factors other than "1" must be weighted. In this case, since there are generally many internal links to be weighted, the time required for the weighting process is inevitably long. Therefore, it takes extra time to acquire the recommended route, and it has been desired to reduce the time required for the weighting process.

Therefore, an object of the present invention is to solve the above-mentioned technical problems and to provide an in-vehicle route providing device capable of obtaining a route in which an actual traffic situation is reflected even when there is an unassigned link. It is to be. Another object of the present invention is to provide an in-vehicle route providing device that can shorten the time required for the weighting process and can quickly obtain the route.

[0012]

According to a first aspect of the present invention, there is provided a vehicle-mounted route providing device which includes a link cost associated with an internal link which is a constituent unit of a first route network. Road map data storage means for storing data, data holding means for reading and temporarily holding the road map data stored in the road map data storage means, and roads held by the data holding means An in-vehicle route providing device including a route obtaining unit that obtains a route based on map data, which is associated with an external link, which is a constituent unit of the second route network, transmitted from an external communication device, and Receiving means for receiving road traffic information classified into a plurality of stages, and when the road traffic information is received by this receiving means, the road traffic information is temporarily stored. And an information holding means held in the information holding means, an assigning means for associating the road traffic information held in the information holding means with an internal link corresponding to an external link associated with the road traffic information, and held in the data holding means. According to the rank of the road traffic information associated with the internal link, the link cost of the internal link associated with the road traffic information by the allocating means among the link costs included in the road map data The weighting coefficient is changed to change the link cost of the internal link, and the internal link is not associated with the road traffic information by the allocating means (hereinafter referred to as "non-allocated link").
To the link cost of the non-allocated link by uniformly weighting the expected value of the weighting coefficient to the link cost of the link changing means, and the route acquiring means changes the link changed by the cost changing means. The feature is that the recommended route is acquired using the cost.

A vehicle-mounted route providing apparatus according to a second aspect is the vehicle-mounted route providing apparatus according to the first aspect,
Reference is made to a parallel link table storage means in which a table representing a correspondence relationship between an internal link and a link parallel to the internal link (hereinafter referred to as “parallel link”) is stored, and a table stored in the parallel link table storage means. Then, a parallel link discriminating means for discriminating whether or not there is a parallel link corresponding to the non-allocation link, and the parallel link discriminating means, if the non-allocation link has a parallel link, Includes allocation determination means for determining whether or not road traffic information is associated with the cost change means, and the cost change means is determined by the allocation determination means to be associated with the parallel traffic information. If the link cost of the non-allocated link is the same as the weighting coefficient to be applied to the link cost of the parallel link, And weighting coefficients, and characterized in that to change the link costs of the non-allocated link.

Further, the on-vehicle route providing device according to the present invention is a road map data storage means for storing road map data including a link cost associated with an internal link which is a constituent unit of the first route network. And a data holding means for reading and temporarily holding the road map data stored in the road map data storage means, and a route acquisition for obtaining a route based on the road map data held in the data holding means. An on-vehicle route providing device including means, the road traffic information transmitted from an external communication device, associated with an external link that is a constituent unit of the second route network, and ranked into a plurality of stages. Receiving means for receiving the road traffic information, the information holding means for temporarily holding the road traffic information when the road traffic information is received by the receiving means, and the information holding means for holding the road traffic information. The assigning means for associating the road traffic information held in the holding means with the internal link corresponding to the external link associated with the road traffic information, and the internal link associated with the road traffic information by the assigning means In the case where a weighting factor corresponding to the rank of road traffic information is given and a constant weighting factor is given to the internal link to which the road traffic information is not associated by the allocating means, the same weighting factor among these weighting factors to be given. The weighting coefficient is specified by specifying the weighting coefficient with the largest number of internal links (hereinafter referred to as "maximum multiplexing coefficient") and dividing by the specified maximum multiplexing coefficient other than the maximum multiplexing coefficient. And a weighting coefficient standardized by the weighting coefficient in the internal link other than the internal link to which the maximum multiplexing coefficient is given. By weighting the link of the link cost, and a cost changing means for changing the link cost of the internal links,
The route acquisition means acquires the route in consideration of the change of the link cost in the cost change means.

Further, the on-vehicle route providing device according to the present invention is a road map data storage means for storing road map data including a link cost associated with an internal link which is a constituent unit of the first route network. And a data holding means for reading and temporarily holding the road map data stored in the road map data storage means, and a route acquisition for obtaining a route based on the road map data held in the data holding means. An on-vehicle route providing device including means, the road traffic information transmitted from an external communication device, associated with an external link that is a constituent unit of the second route network, and ranked into a plurality of stages. Receiving means for receiving the road traffic information, the information holding means for temporarily holding the road traffic information when the road traffic information is received by the receiving means, and the information holding means for holding the road traffic information. The assigning means for associating the road traffic information held in the holding means with the internal link corresponding to the external link associated with the road traffic information, and the internal link associated with the road traffic information by the assigning means In the case where a weighting factor according to the rank of road traffic information is given and a constant weighting factor is given to an internal link (hereinafter referred to as “non-allocation link”) to which the road traffic information is not associated by the allocating means, A standardizing means for obtaining a standardized weighting coefficient by dividing a weighting coefficient other than the constant weighting coefficient by a constant weighting coefficient, and a weighting coefficient standardized by the standardizing means for the internal parts other than the non-allocated link. Cost changing means for changing the link cost of the internal link by weighting the link cost of the link. , Taking into account the change in the link cost in the cost changing means, characterized in that for obtaining path.

[0016]

In the structure of the above claim 1, when the road traffic information is received by the receiving means, the road traffic information is associated with the internal link corresponding to the external link with which the road traffic information is associated. . After that, the link cost of the internal link associated with the road traffic information is weighted with a weighting coefficient according to the rank of the road traffic information.
As a result, the link cost can reflect the actual traffic situation.

Since the first route network is created more finely than the second route network, there may be an internal link that does not have a corresponding external link. In addition, although there is a corresponding external link, there are cases where the ranked road traffic information cannot be received from an external communication device due to a failure of a vehicle detector or the like. In such a case, there is an internal link (non-allocation link) to which the road traffic information cannot be associated.

Therefore, in this configuration, when there is a non-allocation link, the expected value of the weighting coefficient is weighted to the link cost of the non-allocation link. Thereby, the link cost of the non-allocation link can be made close to the actual traffic situation. And to get the route,
The changed link cost is used. In this way, according to this configuration, the link cost of the non-allocated link can be changed to a value close to the actual traffic condition, so even if there is a non-allocated link, the route that reflects the actual traffic condition can be changed. Can be obtained.

By the way, when traffic congestion information is considered as road traffic information, for example, it is natural to consider that the congestion level of a certain road is almost the same as the congestion level of a road parallel to the road. Therefore, for example, when the road traffic information is associated with the parallel link corresponding to the non-allocation link as in the configuration according to claim 2, the link cost of the non-allocation link is expected as a weighting coefficient to be weighted. Instead of the value, the same weighting factor as the weighting factor for weighting the link cost of the parallel link may be used. According to this configuration, the link cost of the non-allocated link can be brought closer to the actual traffic situation more accurately.

According to the third aspect of the invention, the internal link associated with the road traffic information received from the external communication device is given a weighting factor according to the rank of the road traffic information. On the other hand, a constant weighting factor is given to the internal links that are not associated with the road traffic information.
In such a case, a standardized weighting coefficient is obtained by dividing the other weighting coefficient by the most multiplexed coefficient having the largest number among the above weighting coefficients. Then, the standardized weighting factors are weighted to the link costs of the internal links other than the internal link to which the maximum multiplexing coefficient should be given. Conversely speaking, the link cost of the internal link to which the maximum multiplexing coefficient should be given is not weighted.

Here, since the standardized weighting coefficients are all obtained by using the most multiplexed coefficient as a divisor, the magnitude relationship between them is similar to the magnitude relationship between the weighting coefficients before calculation. Therefore, when obtaining a route, it is possible to obtain a route tree having the same pattern as in the case where the weighting factor before normalization is weighted to the link cost. Therefore, the same route as when weighting the weighting factor before normalization to the link cost is obtained. Can be obtained.

As described above, according to this configuration, since it is not necessary to execute the weighting process by the maximum multiplexing coefficient for the link cost of the most number of internal links, the time required for the weighting process can be shortened. You can It should be noted that the internal link to which the maximum multiplexing coefficient should be given is generally a non-allocated link in many cases. Therefore, on the premise of such a case, as in the configuration according to claim 4, for example, a standardized weighting coefficient is obtained by dividing another weighting coefficient by a certain weighting coefficient to be given to the non-allocated link, and this standard is calculated. The converted weighting factor may be weighted to the link costs of the internal links other than the non-allocated link. Also with this configuration, since it is not necessary to perform the weighting process using the most multiplexed coefficient for the most number of internal links, the time required for the weighting process can be shortened.

[0023]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. <First Embodiment> FIG. 1 is a schematic diagram of a system for providing road traffic information to a vehicle-mounted navigation device to which the vehicle-mounted route providing device of the present invention is applied. The road traffic information providing system includes a road beacon A installed on the road and an information center C connected to the road beacon A via a communication line (public line or dedicated line) B.

Instead of the above-mentioned road beacon A, a communication device used in, for example, an automobile / cellular phone network or an FM multiplex broadcasting network may be applied. In the above information center C,
In a relatively coarse route network having links (hereinafter referred to as “external links”) L _K that connect major intersections as constituent units, traffic congestion information associated with each external link L _K within a predetermined service area is road traffic information. It is stored as information. Congestion information includes, for each respective external link L _K, corresponding external links L _K link number for identifying, and a degree of congestion degree of congestion J _n include (n = 1 to 3 in this example) There is.

The congestion degree J _n is, in this embodiment, the congestion degree J _n.
1 : No congestion, congestion degree J ₂ : Congestion, congestion degree J ₃ : Congestion,
It is divided into several ranks. This ranking is determined based on, for example, the actually measured speed of the vehicle. For general national roads, the congestion degree J ₁ is a vehicle speed of 40 (Km / h) or more, and the congestion degree J ₂ is a vehicle speed. The speed of 20 is less than 20 (Km / h) and less than 40 (Km / h), and the congestion degree J ₃ corresponds to the case where the speed of the vehicle is less than 20 (Km / h).

The traffic congestion information is given to the on-road beacon A via the communication line B at regular intervals. On the other hand, when the traffic jam information is given via the communication line B, the road beacon A transmits the traffic jam information to the vehicle. FIG. 2 is a block diagram showing an electrical configuration example of a vehicle-mounted navigation device mounted on a vehicle. This on-vehicle navigation device 1
Is provided with a direction sensor 5 for detecting the amount of change in the direction of the vehicle and a distance sensor 6 for detecting the amount of movement of the vehicle. As the direction sensor 5, for example, a gyro such as an optical fiber gyro, a vibration gyro, a gas rate gyro,
Alternatively, a geomagnetic sensor can be applied. Further, as the distance sensor 6, for example, a rotation speed sensor that detects the rotation speed of the tire wheel or the rotor can be applied. The outputs of the azimuth sensor 5 and the distance sensor 6 are given to the vehicle position detection unit 14 in the vehicle-mounted navigation device body 1.

In the vehicle position detector 14, the traveling direction of the vehicle is obtained based on the output of the direction sensor 5, and
The traveling distance of the vehicle is obtained based on the output of the distance sensor 6. Accurate initial position data of the vehicle is given to the vehicle position detecting unit 14 by the driver, for example, before the vehicle starts. In the vehicle position detecting unit 14, the given initial position data and the above-mentioned vehicle are given. The current position of the vehicle is detected based on the traveling direction and the traveling distance of the vehicle. The current location of this vehicle is detected at regular intervals (for example, 0.1 seconds)
It is done every time.

Incidentally, instead of the direction sensor 5, the distance sensor 6 and the vehicle position detecting section 14, or together with the direction sensor 5, the distance sensor 6 and the vehicle position detecting section 14,
GPS (Global Positioning) navigating the orbit of the earth
(System) A GPS receiver for detecting the current position of the vehicle based on the propagation delay time of GPS radio waves transmitted from a satellite may be employed (see, for example, Japanese Patent Laid-Open No. 62-142216).

The vehicle position detector 14 also corrects the detected current position of the vehicle by so-called map matching processing (see, for example, Japanese Patent Laid-Open No. 63-148115). That is, the traveling locus of the vehicle detected based on the outputs of the azimuth sensor 5 and the distance sensor 6 is collated with the road pattern stored in the map-dedicated disk D,
According to the result, the traveling locus of the vehicle is corrected on the road pattern.

The current position data of the vehicle corrected by the map matching process is given to the controller 16. The controller 16 is a control center of the vehicle-mounted navigation device body 1, and includes a CPU 161, an SRAM 162, and a DRAM 163. Controller 1
When the current position data of the vehicle is given from the vehicle position detection unit 14, 6 reads the display road map data around the current position from the map dedicated disk D via the memory control unit 11 and the CD drive 2. The read road map data for display and the present position data thus read are given to the display control unit 12. When the display road map data and the current position data are given, the display control unit 12 superimposes a car mark indicating the current position of the vehicle on the road map and displays it on the display 3 composed of a liquid crystal display device, a plasma display device or a CRT. Display it.

The map-dedicated disk D stores route calculation road map data in addition to the display road map data. Road map data for route calculation divides a road map (including highway national roads, motorways, other national roads, prefectural roads, city roads of ordinance-designated cities, and other important living roads) into a mesh, A relatively fine route network consisting of a combination of links (hereinafter referred to as "internal links") L _N that connect nodes corresponding to road intersections in each mesh unit is a highway / national road map and general road map And a detailed map, which is divided into three layers and includes a link cost, which will be described later.

In addition to the road map data described above, the map-dedicated disk D also includes the congestion degree J _n and the weighting factor included in the congestion information received from the on-road beacon A necessary for the link cost changing process described later. A weighting coefficient table showing a correspondence relationship with K _n , and an external link L _K and an internal link L _N
A correspondence relationship table indicating a correspondence relationship with is stored.

The correspondence between the external link L _K and the internal link L _N is basically 1 as shown in FIG. 3 (a).
Corresponds to-one, but since external link L _K is a structural unit of the general rough route network than internal link L _N, as shown in FIG. 3 (b), a plurality of internal links to external links L _K L _N Is included, or as shown in FIG. 3C, there is an internal link L _N without a corresponding external link L _K. The above correspondence table shows the correspondence relationship in the case of FIGS. 3 (a) and 3 (b), and a concrete example thereof is shown in FIG. 3 (d).

Returning to FIG. 2, the controller 16 has various calculation conditions such as a destination (whether toll roads are prioritized, ferry use is prioritized, or transit points are used). A remote controller key (hereinafter, simply referred to as a “remote control key”) 4 for inputting (for example) is connected via the input control unit 13. On the remote control key 4,
For example, when you want to get the recommended route between the current location and the destination, you can input a route calculation instruction signal with one touch, such as "route key", "destination setting", "route setting". , Etc. (not shown).

When the driver inputs various calculation conditions such as a destination through the remote control key 4 by the driver, the controller 16 stores the input destination data and the like in the SRAM 162.
In addition to being stored in, the road map data for route calculation of the range including the starting point and the destination is read out from the map-dedicated disk D and held in the SRAM 162. At this time, the route calculation road map data is held in the form of a link table as shown in Table 1 below. In this link table, the identification number (link number) of each internal link L _N , the link length (link distance), the road type such as a highway and a general road, the coordinates of the start point and the end point of the internal link L _N , and the inside thereof The link cost, which is the traveling time when passing through the link L _N , the connection cost of the exit link, the pointer to the exit link, and the like are included. Further, when the traffic jam information is received from the road beacon A, a space is provided for writing the traffic jam degree J _n included in the traffic jam information.

[0036]

[Table 1]

The link cost is usually the cost for traveling at the legal speed, but when the traffic jam information is received from the road beacon A, a change is made in consideration of the traffic jam information. This changing process will be described later. Here, leaving the definition of the word, the next link in the case of looking at the next internal link L _N from the end point of the internal link L _N are connected to the internal links L _N of "exit links". The “connection cost” means the cost of turning left or right or going straight from the internal link L _N to the exit link. For example, in the case of no entry, the connection cost becomes infinite, and when there is a signal, the cost takes into consideration the average signal waiting time when turning right or left or going straight.

The route calculation road map data is SRAM16.
When held in 2, the CPU 161 determines the internal links L _N close to the destination and the current position detected by the vehicle position detection unit 14 based on the route calculation road map data.
The recommended route between them is obtained using, for example, the Dijkstra method or the potential method. The acquired recommended route is superimposed and displayed on the road map displayed on the display 3 by, for example, a broken line, and is acoustically output from the microphone M via the voice control unit 18.

Here, the potential method is the following method. In other words, internal links L _N close to the departure point (or the destination) to the calculated start links, the nearest internal links L _N to the destination (or a departure point) and the calculation end link, internal links starting from the calculation start link Search all L _N. At this time, the process of sequentially adding the link costs of the respective internal links L _N included in the route calculation road map data, discarding the route that is not the shortest route, and leaving only the route that realizes the shortest route is repeated. as a result,
Finally, since the route tree consisting of only the shortest route is obtained, the recommended route can be obtained by tracing the route from the calculation end link to the calculation start link in reverse.

The beacon receiver 7 is also connected to the controller 16. The CPU 161 receives the traffic jam information in the service area (which is often a narrow area of several km square, so it is generally narrower than the range including the starting point and the destination) transmitted from the road beacon A. When received by the beacon receiver 7, the traffic jam information is given to the SRAM 162 to be temporarily held. C
When the PU 161 acquires the recommended route by the above method and the congestion information is held in the SRAM 162, the PU 161 selects the service area among the internal links L _N of the constituent units of the route calculation road map data held in the SRAM 162. The link cost of the internal link L _N is changed based on the traffic jam information, and the recommended route is acquired using the changed link cost.

FIG. 4 and FIG. 5 are flowcharts for specifically explaining the process of acquiring the recommended route when the traffic information is received from the road beacon A in the vehicle-mounted navigation device 1. While the vehicle is running, FIG.
As shown in, when the traffic jam information transmitted from the road beacon A is received (step S1), the traffic jam information is temporarily held in the SRAM 162. At this time, CP
The U 161 reads the correspondence table and the weighting coefficient table from the map-dedicated disk D and stores them in the SRAM 162. After that, a process of associating the congestion degree J _n included in the congestion information with the internal link L _N is executed (steps S2 to S10).

More specifically, first, all congestion degrees J _n to be associated with the internal link L _N are initialized (step S2). As a result, the initial value j is written in the space in the SRAM 162 in which the congestion degree of the link table should be written. Next, an arbitrary external link L _K is set as a congestion degree assignment target, and the external link L _K is linked to the external link L _K based on the link number included in the congestion information and the correspondence table held in the SRAM 162. Internal link L _N corresponding to link L _K
Is specified, and the congestion degree J _n is associated with the internal link L _N (steps S3 to S8). For example, congestion degree J
If it is ₁ , J ₁ is written in the congestion degree space of the above link table.

Here, in this congestion degree assignment processing, an internal link L _N without a corresponding external link L _K as shown in FIG. 3 (c), or as shown in FIG. 3 (a) or FIG. 3 (b). Although there is a corresponding external link L _K, the internal link L in which the congestion degree J _n is not transmitted due to a failure of the vehicle detector or the like
_The congestion degree J _n cannot be associated with _N (hereinafter collectively referred to as “non-allocation link L _W ”). Therefore, in the first embodiment, the congestion degree to be associated with the non-allocation link L _W is left as the initial value j (step S9).

After that, the above process is repeated using another external link L _K as a congestion degree allocation target link (step S1).
0, S11). Then, when the allocation process for all the external links L _K is completed (YES in step S10),
Next, a process for changing the link cost by weighting the link cost of each internal link L _N with a weighting coefficient K _n according to the associated congestion degree J _n is executed (step S12-). S20).

Here, the link cost is changed by the congestion degree J associated by the congestion degree assignment processing as described above.
_Since it is achieved by weighting the weighting factor K _n according to _n , it is necessary to determine the weighting factor k of the unassigned link L _W with which the congestion degree J _n is not associated. Therefore, as shown in FIG. 5, the CPU 161 causes the congestion degree distribution in the service area of the road beacon A and each congestion degree J.
_The expected value E is obtained based on the weighting coefficient K _n corresponding to _n (step S12), and the expected value E is given as the weighting coefficient k of the internal link L _N (non-allocation link L _W ) of the congestion degree j.

More detailed description of the process of obtaining the expected value E
In other words, the traffic congestion distribution is the service
Congestion degree J in the rear_nAll internal phosphorus associated with
Black L _NCongestion degree J for the number of_nInternal link L_NNumber of
Can be obtained by obtaining the ratio of Above traffic jam
As a result of calculating the degree distribution, for example, the congestion degree J₁: M₁(%),
Congestion degree J₂: M₂(%), Congestion degree J₃: M₃(%), Congestion
When the degree distribution is obtained, this congestion degree distribution and SRA
Each congestion in the weighting coefficient table held in M162
Degree J_nWeighting coefficient K according to_nBased on
As shown, the expected value E is obtained.

[0047]

[Equation 1]

Here, for example, m₁= 80, m₂= 17.5,
m₃= 2.5, and K₁= 1, K ₂= 2, K₃= 6
Then, the expected value E becomes E = 1.3. Expected value E
Upon request, the CPU 161 determines that the internal link L_NStrange
The link to be updated is the internal link L_NAssociated with
Congestion degree J_nIs determined (steps S13, S1
5, S17).

As a result, if the congestion degree is J ₁ (YES in step S13), the weighting coefficient table held in the SRAM 162 is referred to, and the weighting coefficient K ₁ corresponding to the congestion degree J ₁ is changed to the internal link. Multiply the link cost of L _N. (Step S14). Similarly, the congestion levels J ₂ , J ₃
If (YES in step S15, YES in step S17), referring to the weighting coefficient table, the weighting factor K _2, K ₃ corresponding to the degree of congestion J _2, J _3, the link cost of the internal link L _N (Step S16,
S18).

On the other hand, if none of the congestion degrees J _n is applicable, the CPU 161 determines that the internal link L _N is the non-allocation link L _W having the congestion degree of the initial value j.
The link cost of the non-allocated link L _W is multiplied by the expected value E obtained in step S12 (step S1).
9). The above processing is executed for all the internal links L _N (steps S20 and S21). As a result, the current congestion situation can be added to the link cost of the internal link L _N. Therefore, the link cost can reflect the actual traffic situation.

When the link cost changing process is completed, the recommended route is acquired by the above method using the changed link cost (step S22). Then, the vehicle is guided according to the recommended route (step S23). As described above, the vehicle-mounted navigation device 1 according to the first embodiment
According to the above, since the link cost of the non-allocated link L _W is weighted by the expected value E of the weighting coefficient K _n , even if there is the non-allocated link L _W , the link costs of all the internal links L _N are actually calculated. It can be one that reflects traffic conditions. Therefore, it is possible to obtain the recommended route that reflects the actual traffic conditions. Therefore, it is possible to obtain a more preferable recommended route such that the destination can be reached in the shortest time. <Second Embodiment> In the vehicle-mounted navigation device 1 according to the second embodiment, unlike the first embodiment in which the expected value E is adopted as the weighting coefficient k of the non-allocation link L _W , the non-allocation link L is used.
_It is characterized in that the weight coefficient K _n is the same as the weight coefficient K _{n of} the external link L _K or the internal link L _N (hereinafter referred to as “parallel link L _H ”) parallel to _W. This means that, for example, when a road is congested, it is natural to think that the roads parallel to the road are also congested to the same degree.
It is based on the viewpoint.

The vehicle-mounted navigation device of the second embodiment
An internal link L is attached to the map-dedicated disk D in Table 1._NAnd the said
Internal link L_NParallel link L corresponding to_HCorrespondence with
A parallel link table representing is stored. This parallel
The link table is, for example, as shown in FIG.
External link L_K1, L_K2Internal link L connecting between₁Corresponding to
Parallel link L_HAs multiple internal links L₂,
L₃, L_FourIf there is, the format is as shown in Fig. 6 (b).
It Also, as shown in FIG. 6 (c), each external link L _K2,
L_K3Multiple internal links L connecting between₁, L₂, L₃, L
_Four, L_FiveParallel link L corresponding to_HAs one external resource
Link L_K1If there is only one, the parallel link table is shown in Fig. 6 (d).
The format is as shown in.

7 and 8 are flow charts for specifically explaining the recommended route acquisition processing when the traffic information is received from the road beacon A in the vehicle-mounted navigation device 1 according to the second embodiment. . The flowcharts shown in FIGS. 7 and 8 are different from the flowcharts shown in FIGS. 4 and 5 of the first embodiment in that the parallel link reference process (step P12) is added after the congestion degree assignment process is completed. And the expected value E in step S12 of the flowchart shown in FIG.
And the process of weighting the expected value E to the link cost in step S19 is deleted.
They differ in terms. Therefore, in the following, this difference will be mainly described with reference to the flowchart shown in FIG. 9 for explaining the parallel link reference processing. Note that step S in the flowchart shown in FIG.
The reason for deleting the processing of S12 and S19 will be described later.

When the traffic jam information is received from the road beacon A, the CPU 161 reads the parallel link table from the map-dedicated disk D and holds it in the SRAM 162.
After that, when the congestion degree assignment process ends (step P10).
YES), the CPU 161 extracts the unassigned link L _W of the congestion degree j, and then, as shown in FIG.
(Step P121), the parallel link table stored in the above is linked to any of the parallel links L _H corresponding to any non-allocation link L _W of the extracted non-allocation links L _W. It is determined whether or not the congestion degree J _n is associated with _H (step P122). As a result, if it is determined that the congestion degree J _n is not associated, the same process is repeated with another parallel link L _H as the determination target (step P123). The parallel link L when congestion degree J _n is determined that associated with _H, the parallel link L same congestion degree as congestion degree J _n of _H J _n
To the non-allocated link L _W (step P12)
4).

After that, the same processing is repeated with other non-allocation links L _W as congestion degree allocation targets (step P12).
5, P126). Then, when the above process is completed for all the non-allocated links L _W (YE in step P125).
S), and the process proceeds to step P13 in FIG. in this way,
In the above flowchart, the non-assigned link L _W, since the association of the same congestion degree J _n and congestion degree J _n associated with the parallel link L _H corresponding to the non-allocated link L _W, unallocated link The link cost of L _W will be weighted with the same weighting factor K _n as the corresponding parallel link L _H. Therefore, the processes of steps S12 and S19 shown in FIG. 5 of the first embodiment are unnecessary.

[0056] An in-vehicle navigation apparatus 1 of the second embodiment as described above, the link cost of the non-allocated link L _W, the non-assigned link L _W parallel link near L _H
Since it is changed in the same manner as the above, the link cost can be brought closer to the actual traffic situation more accurately than in the case of the first embodiment in which the link cost of the non-allocated link L _W is changed using the expected value E. You can Therefore, it is possible to acquire the recommended route that more accurately reflects the actual traffic situation.

In the parallel link reference process,
Appropriate parallel link L for the target unassigned link L _W
If _{the H} can not be associated with congestion degree J _n to the non-allocated link L _W in the absence of, for example link cost of the non-allocated link L _W by multiplying the expected value E described in the first embodiment May be changed. <Third Embodiment> The vehicle-mounted navigation device 1 according to the third embodiment assumes a case where it is known in advance that the number of unassigned links L _W is the largest among the internal links L _N. This assumption is usually established because the unallocated link L _W occupies about 60% of the internal link L _N.
The feature of the third embodiment is that the link costs of the internal links L _N other than the non-allocated link L _W are not weighted by the weighting factors K _n , but are weighted by standardized weighting factors described later. It is in.

In the vehicle-mounted navigation device 1 according to the third embodiment, the congestion degree assignment processing is exactly the same as the flow chart shown in FIG. 4 of the first embodiment, so the description thereof will be omitted. On the other hand, since the link cost changing process is different, the link cost changing process in the vehicle-mounted navigation device 1 according to the third embodiment will be described below with reference to the flowchart shown in FIG.

When the congestion degree assignment processing ends (step S
10 (YES in 10), the CPU 161 obtains the expected value E based on the congestion degree distribution in the service area of the road beacon A and the weighting coefficient K _n corresponding to each congestion degree J _n (step T1). Next, another weighting coefficient K _n is divided by the obtained expected value E (step T2). As a result, the standardized weighting factor I _n is obtained. That is, I ₁ = K ₁ /
E, I ₂ = K ₂ / E, I ₃ = K ₃ / E are obtained.

After that, the CPU 161 determines the congestion degree J _n (n = 1 to 3) of the target internal link L _N , and targets the standardized weighting factor I _n according to the determined congestion degree J _n. The link cost of the internal link L _N is weighted (steps T3 to T8). At this time, since the unassigned link L _W has the congestion degree j, the link cost of the unassigned link L _W is not weighted. And another internal link L
The same process is repeated with _N as the link cost change target link (steps T9 and T10).

The internal link L _N that should be the target of the above processing
Is executed for all of the
S), CPU 161 obtains a recommended route using the link costs, including link cost weighted by normalized weighting coefficients I _n (step T11). Here, since all the standardized weighting factors I _n are obtained by using the expected value E as a divisor, the magnitude relation between them is similar to the relation between the weighting factors K _n before calculation. Therefore, when acquiring the recommended route, the route tree having the same pattern as in the case where the weighting coefficient K _n is weighted to the link cost can be obtained. Then, the vehicle is guided according to the obtained recommended route (step T12).

As described above, according to the vehicle-mounted navigation device 1 of the third embodiment, it is not necessary to perform weighting processing on the link cost of the unassigned link L _W having the largest number among the internal links L _N. Therefore, the time required for the cost change process can be shortened. For example, if there are 2000 internal links L _N to be modified (which is determined by the service area of road beacon A),
If the number of unallocated links L _W is 1200, for example, the time required to change one link cost is 12 (msec).
In this case, it is not necessary to change the link cost of the non-allocated link L _W , so 1200 (lines) × 12 (ms
It is possible to shorten the time by ec) = 14.4 (msec).

[0063] Further, since the adopted expectation value E as the divisor for obtaining the weight coefficients I _n which is normalized, actual traffic conditions reflect the link costs weighted by normalized weighting coefficients I _n You can get closer to what was done.
In the third embodiment, the case where the expected value E is adopted as the weighting coefficient to be given to the non-allocation link L _W is explained, but a predetermined constant weighting coefficient may be adopted, for example. .

In the third embodiment, it is assumed that the number of non-allocated links L _W is the largest among the internal links L _N , but it is included in the traffic jam information received from the road beacon A, for example. the number of internal links L _W where either congestion degree J _n associated among the congestion degree J _n in which it is considered that the most frequently among the internal links L _n in the service area of the road beacon a. Therefore, it is conceivable to execute the processing described below.

First, after the congestion degree allocation processing is completed and the expected value E to be used as the weighting coefficient of the non-allocation link L _W is obtained, any congestion degree J _n (where the congestion degree is the initial value j is also included. )
Internal link L _N associated to determine highest among all internal links L _N that is a change target. as a result,
If it is determined that the weighting coefficient (maximum multiplexing coefficient) K _{n to} be given to the internal link L _N determined to be the most, for example, the internal link L _N associated with the congestion degree J ₃ is the most, the congestion is concerned. The weighting factors “K ₁ / K ₃ ”, “K ₂ / K ₃ ”, and “K ₂ / K ₃ ”, which are standardized by dividing the other weighting factors K ₁ , K ₂ , E by the weighting factor K ₃ according to the degree J _3. E /
K ₃ ”. Then, the standardized weighting factors “K ₁ / K ₃ ”, “K ₂ / K ₃ ”, and “E / K ₃ ” are assigned to internal links other than the internal link L _N associated with the congestion degree J _3. The link cost of L _N is weighted according to the congestion degree J _n .

According to this configuration, the weighting process can be omitted for the link cost for which the same weighting coefficient K _n must be weighted most.
The time required for the change process can be shortened. Further, in the third embodiment, as the weighting coefficient to be given to the non-allocation link L _W , the weighting coefficient K corresponding to each congestion degree J _n is used.
_Although the expected value E of _n is applied, another fixed value may be applied instead of the expected value E, for example. <Other Embodiments> The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments. For example, in the above-mentioned first, second and third embodiments, the internal link L _N within the service area of the road beacon A is adopted as the target internal link L _N of the congestion degree distribution required when obtaining the expected value E. However, the target internal link L _N of the congestion degree distribution may be, for example, the internal link L _N within a limited range within the service area, or only the exit link of each unallocated link L _W.

In the first, second and third embodiments, the expected value E is calculated every time the in-vehicle navigation device 1 receives the traffic congestion information. For example, the traffic congestion degree statistically acquired. The expected value E may be obtained in advance using the distribution, and the expected value E may be stored in advance in the map-dedicated disk D by the creator of the road map data. According to this configuration, it is not necessary to obtain the expected value E each time the traffic congestion information is received, so that the processing is simplified and the time required to acquire the recommended route can be shortened.

Various other design changes can be made within the scope of the present invention.

[0069]

As described above, according to the vehicle-mounted route providing device of the first aspect, the link cost of the non-allocated link to which the road traffic information is not associated is also weighted by the weighting coefficient to which the road traffic information is added. Therefore, as a result, the link cost can be considered to reflect the actual traffic situation. Therefore, it is possible to acquire a route that reflects the actual traffic situation. Therefore, as a route, for example, the number of times of selecting a congested route can be minimized. As a result, it is possible to obtain a more preferable route such that the destination can be reached in the shortest time.

According to the vehicle-mounted route providing apparatus of the present invention, the link cost of the non-allocation link is changed in the same manner as the parallel link in the vicinity of the non-allocation link. It is possible to bring the cost closer to the actual traffic situation compared to the case where the cost is changed using the expected value. Therefore, it is possible to acquire a route that more accurately reflects the actual traffic situation.

Further, according to the vehicle-mounted route providing apparatus of the third or fourth aspect, the weighting process by the most multiplexed coefficient does not have to be executed for the link cost of the most number of internal links. The time required for can be shortened. Particularly, according to the vehicle-mounted route providing device of the fourth aspect, it is premised that the maximum-multiplexing coefficient is a constant weighting coefficient to be given to the non-allocated link, so that the maximum-multiplexing coefficient is specified from the weighting coefficients. No need. Therefore, the processing can be simplified as compared with the configuration according to claim 3.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing a system for providing congestion information to an on-vehicle navigation device to which an on-vehicle route providing device of the present invention is applied.

FIG. 2 is a block diagram showing an electrical configuration example of the vehicle-mounted navigation device.

FIG. 3 shows a correspondence relationship between an external link, which is a constituent unit of a route network prepared on the road beacon side, and an internal link, which is a constituent unit of the route network prepared on the in-vehicle navigation device side, and a correspondence relationship table. It is a figure for explaining.

FIG. 4 is a flowchart for explaining a process of acquiring a recommended route when the traffic jam information is received in the vehicle-mounted navigation device according to the first embodiment of the present invention.

FIG. 5 is likewise a flow chart for explaining a process of acquiring a recommended route when the traffic jam information is received in the vehicle-mounted navigation device according to the first embodiment of the present invention.

FIG. 6 is a diagram for explaining a parallel link table held in the vehicle-mounted navigation device according to the second embodiment of the present invention.

FIG. 7 is a flowchart for explaining a process of acquiring a recommended route when receiving traffic congestion information in the vehicle-mounted navigation device according to the second embodiment of the present invention.

FIG. 8 is a flow chart for explaining a process of acquiring a recommended route when the traffic jam information is received in the vehicle-mounted navigation device according to the second embodiment of the present invention.

FIG. 9 is a flow chart for explaining a parallel link reference process which is a characteristic process of the second embodiment of the present invention.

FIG. 10 is a flowchart for explaining a process of acquiring a recommended route when receiving traffic congestion information in the vehicle-mounted navigation device according to the third embodiment of the present invention, which is a characteristic feature of the third embodiment. It is a flow chart for explaining processing mainly.

[Explanation of symbols]

1 vehicle navigation apparatus 7 beacon receiver 16 controller 161 CPU 162 SRAM A road beacon E expected value J _n, J ₁ ~J ₃ congestion degree K _n, K ₁ ~K ₃ weight coefficients I _n, I ₁ ~I ₃ standard Generalized weighting factor L _K external link L _N internal link L _W unassigned link L _H parallel link

Claims (4)

[Claims] 1. A road map data storage means for storing road map data including a link cost associated with an internal link which is a constituent unit of a first route network; and a road map data storage means for storing the road map data. An in-vehicle route providing device comprising: a data holding unit for reading and temporarily holding road map data stored therein; and a route acquiring unit for acquiring a route based on the road map data held in the data holding unit. A receiving means for receiving road traffic information transmitted from an external communication device, the road traffic information being associated with an external link which is a constituent unit of the second route network and classified into a plurality of stages; When the traffic information is received, the information holding means for temporarily holding the road traffic information and the road traffic information held in the information holding means are displayed. Of the link costs included in the road map data held in the data holding means, the allocating means that associates the internal links with the external links with which the road traffic information is associated, The link cost of the internal link associated with the information is weighted with a weighting coefficient according to the rank of the road traffic information associated with the internal link to change the link cost of the internal link, and the allocation means is also provided. Cost of changing the link cost of the non-allocation link by uniformly weighting the expected value of the weighting coefficient to the link cost of the internal link (hereinafter referred to as "non-allocation link") to which the road traffic information is not associated with Changing means, the route obtaining means obtains the recommended route using the link cost changed by the cost changing means. An on-vehicle route providing device characterized by being obtained. 2. A parallel link table storage means for storing a table showing a correspondence relationship between an internal link and a link parallel to the internal link (hereinafter referred to as "parallel link"), and the parallel link table storage means. A parallel link discriminating means for discriminating whether or not there is a parallel link corresponding to the non-allocated link, and the parallel link discriminating means discriminates that the non-allocated link has a parallel link. And the allocation determining means for determining whether or not the parallel link is associated with the road traffic information, wherein the cost changing means associates the parallel link with the road traffic information in the allocation determining means. When it is determined that the link cost of the non-allocated link is weighted, the link cost of the parallel link is weighted. By weighting the same weight coefficient as the coefficient, vehicle route providing apparatus according to claim 1, characterized in that to change the link costs of the non-allocated link. 3. A road map data storage means for storing road map data including link costs associated with an internal link which is a constituent unit of the first route network, and the road map data storage means for storing the road map data. An in-vehicle route providing device comprising: a data holding unit for reading and temporarily holding road map data stored therein; and a route acquiring unit for acquiring a route based on the road map data held in the data holding unit. A receiving means for receiving road traffic information transmitted from an external communication device, the road traffic information being associated with an external link which is a constituent unit of the second route network and classified into a plurality of stages; When the traffic information is received, the information holding means for temporarily holding the road traffic information and the road traffic information held in the information holding means are displayed. An assigning means for associating the internal link corresponding to the external link with which the road traffic information is associated, and a weighting coefficient according to the rank of the road traffic information is given to the internal link with which the road traffic information is associated by this assigning means. In the case where a constant weighting factor is given to the internal links to which the road traffic information is not associated by the assigning means, the number of internal links to which the same weighting factor is given is the largest among the weighting factors to be given. Standardizing means for specifying a weighting coefficient (hereinafter referred to as "maximum multiplexing coefficient") and dividing the weighting coefficient other than the maximum multiplexing coefficient by the specified maximum multiplexing coefficient to obtain a standardized weighting coefficient; Weighting the weighting coefficient standardized by the digitizing means to the link cost of the internal links other than the internal link to which the above-mentioned maximum multiplexing coefficient is given. And a cost changing unit that changes the link cost of the internal link, wherein the route acquiring unit acquires the route in consideration of the change of the link cost in the cost changing unit. In-vehicle route providing device. 4. A road map data storage means for storing road map data including link costs associated with internal links which are constituent units of the first route network, and stored in the road map data storage means. An in-vehicle route providing device comprising: a data holding unit for reading and temporarily holding road map data stored therein; and a route acquiring unit for acquiring a route based on the road map data held in the data holding unit. A receiving means for receiving road traffic information transmitted from an external communication device, the road traffic information being associated with an external link which is a constituent unit of the second route network and classified into a plurality of stages; When the traffic information is received, the information holding means for temporarily holding the road traffic information and the road traffic information held in the information holding means are displayed. An assigning means for associating the internal link corresponding to the external link with which the road traffic information is associated, and a weighting coefficient according to the rank of the road traffic information is given to the internal link with which the road traffic information is associated by this assigning means. In the case where a constant weighting factor is given to the internal link (hereinafter referred to as “non-allocation link”) to which the road traffic information is not associated by the allocating means, the constant weighting factor other than the constant weighting factor is used. Standardizing means for obtaining a standardized weighting coefficient by dividing the weighting coefficient; and weighting the weighting coefficient standardized by the standardizing means to the link costs of the internal links other than the non-allocated link, Cost changing means for changing the link cost of the link, wherein the route acquisition means is a link controller in the cost changing means. Taking into account the bets changes, vehicle route providing apparatus characterized in that for obtaining path.