JP2002206936A - Method of calculating route, and device for executing the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a route information providing device capable of calculating exactly a recommended route to be exhibited, even in significant meteorology. SOLUTION: This device is provided with a receiving means 11 for traffic information, a weather determination means 23 for determining meteorological classification in every link based on a reception data of meteorological information, tables 20, 21, 22 described with data for calculating a value of a link cost in every meteorological classification, a dynamic link cost generating means 13 for generating a dynamic link cost based on the received traffic information, a static link cost generating means 14 for generating a static link cost based on the meteorological classification and the data on the tables, and a route calculating means 17 for calculating the recommended route using the respective link costs generated by the dynamic link cost generating means and the static link cost generating means. The recommended route is exactly calculated irrespective of weathers, since the recommended route is calculated using the link costs in response to the weather.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for calculating a recommended route to be followed by a vehicle in a car navigation system and the like, and an apparatus for presenting a recommended route obtained by the calculation method. The recommended route is calculated and presented.

[0002]

2. Description of the Related Art Conventionally, a road traffic information communication system (VI)
CS) provides information on traffic congestion, section travel time, and event information such as accidents / constructions / regulations to traveling vehicles through FM multiplex broadcasting, radio beacons, and optical beacons. A VICS-compatible navigation device mounted on a vehicle has a function of receiving traffic information and using the information to automatically search for a route that can reach a destination faster.

[0003] Some privately operated car navigation media (information providing service for automobiles) use a dynamic route that provides a vehicle with a route that can reach a destination in the shortest time at the present time based on traffic information and the like. We have an information service.

[0004] The recommended route is calculated using the link cost set for each road. In the road network, node numbers are defined for nodes such as intersections, and link numbers are defined for links representing roads between nodes. Each link has a required time (travel time) for passing through the link. Is set as the link cost.

FIG. 10 schematically shows a road network.
For each link, a static link cost is set based on past statistical information and observation information. FIG. 9 exemplifies a link cost table for obtaining a static link cost of a certain link. Each link cost is defined based on past statistical information by dividing into day types and time zones in which traffic volume fluctuates. I have. Also, the link 23 where the vehicle detector is installed,
In steps 25, 56 and 58, the dynamic link cost corresponding to the current traffic condition is calculated based on the measurement result of the vehicle sensor.

At the present time, nodes 1 to 9
When a recommended route to the vehicle is determined, for a link without a vehicle sensor, the static link cost corresponding to the current date and time is calculated from the link cost table, and for a link with a vehicle sensor, The link costs are obtained, and the route that minimizes the sum of the link costs is calculated.

[0007] The setting of the link cost also takes into account the point of view of transportation policy. The cost is set higher and the link cost of the main road is set lower.

[0008]

However, traffic conditions vary considerably depending on the weather, and when rain or snow falls, the vehicle traveling speed decreases, and the time required for passing through the link increases, but conventionally, the weather conditions change. The setting of the considered static link cost is not performed. On the other hand, the dynamic link cost reflects the actual traffic condition, and the link cost increases on rainy or snowy days.

As a result, when the recommended route is calculated, there is a problem that a route via a link for which a static link cost is set is selected while avoiding the main road where the vehicle sensor is installed as much as possible. appear.

SUMMARY OF THE INVENTION The present invention solves such a conventional problem, and provides a route calculation method capable of accurately calculating a recommended route even in bad weather. It is an object of the present invention to provide a device that can present a recommended route based on the information.

[0011]

Therefore, according to the present invention, in a route calculation method for setting a link cost of each link and calculating a recommended route based on the link cost, a link cost for each weather type is obtained in a table. The basic cost is described, the value of the link cost corresponding to the weather type is obtained from the basic data of the table, and the value is used for calculating the recommended route.

A route information providing apparatus that calculates a recommended route based on the link cost of each link and provides information on the calculated recommended route includes traffic congestion information, link travel time information, accidents, construction, regulations, and the like. Receiving means for receiving traffic information including event information, weather determining means for determining a weather type for each link or area from received data of weather information, and data for calculating a link cost value for each weather type. A description table, a dynamic link cost generating means for generating a dynamic link cost from the traffic information received by the receiving means, and a static link cost using the weather type determined by the weather determining means and the data of the table. And a link cost generated by the dynamic link cost generating means and the static link cost generating means. It is provided with route calculation means for calculating a route.

Therefore, by calculating a recommended route using a link cost according to the weather, an accurate recommended route can be calculated without being influenced by the weather, and accurate route information can be presented. .

[0014]

FIG. 1 shows a route information providing apparatus according to an embodiment of the present invention. This device 10 has a VIC
Information on traffic congestion, link travel time, accidents / construction /
Traffic information including event information such as regulation is received, and data for determining the weather such as temperature measurement data is received, and route information considering the weather is provided.

The apparatus 10 includes a traffic information receiving unit 11 for receiving traffic information, a latest received information storage buffer 12 for storing the latest received information, and a dynamic link for generating a dynamic link cost from the received traffic information. A cost generating unit 13, a default speed setting table 20 having data of assumed speed of the vehicle according to the weather, statistical information databases 21 to 22 in which link cost information for the past several years is accumulated according to the weather, and A weather determination unit 23 to be determined; a weather determination result table 24 in which the weather for each link or area is described separately for each elapsed time based on the determination result of the weather determination unit 23; a default speed setting table 20 and statistical information A static link cost generator 14 that generates link costs according to the weather using the information of the databases 21 to 22, and a dynamic link cost generator 13 and a static link cost generator 14 A route calculation link costs buffer 16 for storing the link cost that is, the route search network database which data of the road network is stored
15 and a route calculation unit 17 that calculates a recommended route using the link costs stored in the route calculation link cost buffer 16.
A route travel time calculator 18 that calculates the travel time of the route calculated by the route calculator 17; information on the recommended route calculated by the route calculator 17; information on the travel time calculated by the route travel time calculator 18; And a route information transmitting unit 19 for transmitting the information.

The weather judging unit 23 measures the temperature and rainfall of each place, the road surface reflectance of each road (the reflectance changes when the road surface gets wet with rain), and the data of the road surface sensor that detects the dryness / wetness of the road surface. , Obtain data indicating whether the wiper of the vehicle running on each road is operating, or
Commercially available weather forecast data (for example, after 3 hours, 6 hours, 12
The weather forecast data after time is acquired, the weather of each link or each area is determined, and the weather is described in the weather determination result table 24. The data of the weather forecast may be manually input.

The weather determined by the weather determination unit 23 is sunny, cloudy, light rain, heavy rain, snowfall, fog, and the like.

FIG. 2 shows that at each link, 5 minutes later, ‥, N
Weather judgment result table 24 describing the weather type at the time ahead
FIG. 3 shows an example of a weather determination result table 24 in which similar weather types are described in area units.

FIG. 4 shows an example of the default speed setting table 20. In this table, assumed speed data of vehicles for each road type in each weather is described separately for day types and time zones.

FIG. 5 shows the statistical information database 21 to
22 shows an example of the accumulated statistical information. This database shows the results of statistical processing of link cost data for several years for each link, and the average value of link costs during this period and the standard deviation indicating the variation of link costs are shown in It is described separately for weather type, day type and time zone. The weather types are fine, cloudy, light rain, heavy rain,
Snow, fog, etc.

The operation of this apparatus will be described with reference to the flowchart of FIG. Step 1: The traffic information receiving unit 11 receives traffic information including traffic jam information, link travel time information, and event information such as accidents / constructions / regulations, and the received traffic information is stored in the latest received information storage buffer 12. . Step 2: The weather judgment unit 23 receives various data for judging the weather in each place. Step 3: Creates a weather judgment result table 24 for each link (FIG. 2) or each area (FIG. 3). Step 4: The dynamic link cost generation unit 13 and the static link cost generation unit 14 calculate the link cost of each link that changes according to the elapsed time due to a change in weather or the like.

FIG. 7 shows a procedure for generating the link cost. Step 10: The static link cost generation unit 14 obtains, from the weather determination result table 24, the weather type data of each link 5 minutes later, ‥, and N hours later. When the weather determination result table 24 is in units of area, the relationship between each link and the area is obtained from the route search network database 15, and the weather type data that changes according to the elapsed time of each link is obtained based on the relationship. . Step 11: Next, the default speed setting table 20
From FIG. 4, an assumed speed having the same weather type, road type, day type, and time zone is selected. It is calculated and written into the link cost buffer 16 for route calculation. FIG. 8 shows link costs that change according to the elapsed time of each link written in the link cost buffer 16 for route calculation. Step 12: In addition, the static link cost generation unit 14 reads the link cost average value of the day type and time zone corresponding to each link from the statistical information databases 21 to 22 using the statistical information of the corresponding weather type. This is overwritten in the link cost buffer 16 for route calculation. Step 13: The dynamic link cost generation unit 13 reads the link travel time information from the traffic information stored in the latest received information storage buffer 12, converts the travel time information into link cost, and links the route calculation link cost buffer 15 Is overwritten as the current link cost of the corresponding link. Further, from this traffic information, congestion information and event information such as accidents / constructions / regulations are read out, these penalty items are converted into link costs in consideration of the weather, and the corresponding link cost in the link cost buffer 16 for route calculation. Overwrites the near future link cost of the link.

In this case, looking at the actual data preparation status, the area where the link cost needs to be set using the data of the default speed setting table 20 is the largest, and the data of the statistical information databases 21 to 22 are used. The area where the link cost can be set follows, and the range where the link cost can be set based on the measurement data provided from the traffic information is still narrow. However, as in this procedure, by overwriting in each step, the link cost of each link that changes depending on the weather and changes according to the elapsed time is set more accurately and without omission. Becomes possible.

When the generation of the route search link cost is completed, step 5: The route calculation unit 17 uses the link cost stored in the route calculation link cost buffer 16 to store the road stored in the route search network database 15. The network is searched for a route that minimizes the added value of the link cost. At this time, the route calculation unit 17 calculates the route using the right / left turn cost according to the weather as the right / left turn cost. The right / left turn cost is the cost of the time required for the vehicle to make a right / left turn, and the right / left turn cost increases in bad weather.

Step 6: The route travel time calculator 18 calculates the travel time along the route searched by the route calculator 17 using the link travel time information included in the received information. Step 7: The route information transmission unit 19 uses the route information calculated by the route calculation unit 17 and the information on the required time calculated by the route travel time calculation unit 18 together with other additional information as dynamic route information. Send.

As described above, in this route information providing device,
Since the values that take the weather into consideration are set for the link cost, the right / left turn cost, the cost associated with traffic congestion, and the like, the recommended route can be accurately obtained under any weather. In addition, since the link cost of each link that changes depending on the weather and changes according to the elapsed time is set, a recommended route at a future time point can be predicted and provided.

The route information providing device of the present invention can be applied to a car navigation device, a device for providing a center type vehicle information providing service, and the like.

[0028]

As is clear from the above description, the route calculation method of the present invention and the route information providing device for presenting the route information obtained by the method provide an accurate recommended route regardless of the weather. Can be calculated, and accurate route information can be presented.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a route information providing device according to an embodiment of the present invention;

FIG. 2 is an exemplary view showing a data configuration of a link unit stored in a weather determination result table according to the embodiment;

FIG. 3 is a diagram showing a data configuration in area units stored in a weather determination result table according to the embodiment;

FIG. 4 is a diagram showing a data configuration stored in a default speed setting table according to the embodiment;

FIG. 5 is a diagram illustrating a data configuration of a weather-specific statistical information database according to the embodiment;

FIG. 6 is a flowchart showing the operation of the route information providing apparatus according to the embodiment;

FIG. 7 is a flowchart illustrating a risk cost generation procedure of the route information providing apparatus according to the embodiment;

FIG. 8 is a diagram showing data stored in a risk cost buffer of the route information providing device according to the embodiment;

FIG. 9 is a diagram showing a table of static link costs;

FIG. 10 is an explanatory diagram schematically showing a road network.

[Explanation of symbols]

 10 Route information providing device 11 Traffic information receiver 12 Latest received information storage buffer 13 Dynamic link cost generator 14 Static link cost generator 15 Route search network database 16 Link cost buffer for route calculation 17 Route calculator 18 Route travel time Calculation unit 19 Route information transmission unit 20 Default speed setting table 21-22 Statistical information database 23 Weather judgment unit 24 Weather judgment result table

Claims (10)

[Claims] In a route calculation method for setting a link cost of each link and calculating a route based on the link cost, basic data for acquiring a link cost for each weather type is described in a table; From the basic data of
A route calculation method, wherein a value of a link cost according to a weather type is obtained, and the value is used for calculating a route. 2. The information of the weather type is: weather forecast information;
The route calculation method according to claim 1, wherein the route is acquired based on at least one of weather measurement data, road surface sensor data, and wiper operation status data. 3. The route calculation method according to claim 1, wherein the weather type includes at least two types of fine weather, cloudy, heavy rain, light rain, snowfall, and fog. 4. The table describes, as the basic data, an assumed speed classified into a road type, a weather type, a day type, and a time zone, and calculates a value of the link cost according to the weather type from the assumed speed. The route calculation method according to claim 1, wherein: 5. The table describes, as the basic data, a link cost average value of each link by weather type, day type and time zone statistically obtained from past data, and the link cost average value 2. The value of the link cost according to the weather type is used as the link cost.
Path calculation method described in. 6. The route calculation method according to claim 1, wherein values of right / left turn costs and congestion costs used for calculating the route are changed according to the weather type. 7. A link cost value corresponding to the weather type is obtained from basic data of the table based on the predicted weather type, and a route at a future time is calculated using the value. The route calculation method according to claim 1. 8. A route information providing apparatus for calculating a route based on a link cost of each link and providing information on the calculated route, comprising: congestion information, link travel time information, and event information such as accidents, construction, and regulations. Receiving means for receiving traffic information including, weather determining means for determining a weather type for each link or area from received data of weather information, and data for calculating a link cost value for each weather type are described. A dynamic link cost generating means for generating a dynamic link cost from the traffic information received by the receiving means; a static link cost using the weather type determined by the weather determining means and the data of the table. Using the link cost generated by the dynamic link cost generating means and the static link cost generating means, A route information providing device comprising: a route calculation unit that calculates a route. 9. The table includes a road type, a weather type,
9. The route information providing apparatus according to claim 8, wherein the assumed speed is described for each of day type and time zone. 10. The link cost average value of each link for each weather type, day type and time zone statistically calculated from past data is described in the table. The route information providing device according to.