JP2003161628A - Car navigation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To search a route adapted to actual meteorological conditions without newly adding a sensor in order to detect the meteorological condition. <P>SOLUTION: The car navigation system is composed so that a GPS receiver 7, a position detector 8, a displaying device 9 and the like are connected to a main device 6 having a map data device 10. A wiper device 2, a car air- conditioner 3, an ABS device 4 and a fog lamp 5 are connected to the main device 6 through a vehicle inside communication system 11, and action information relative to the decision of the meteorological conditions is obtained from them. The main device 6 determines the degree of rainfall (heavy rain) based on the action information of the wiper device 2, judges the freezing state of a road based on the information of outside air temperature from the car air- conditioner 3, determines the snow coverage or the freezing of road based on the action information of the ABS device 4, determines the occurrence of fog based on the lighting information of the fog lamp 5, searches the route while adding the decision of the meteorological condition, and warns a driver in accordance with the decision. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a car navigation device having a location function, a route search function, and a guidance function.

[0002]

A car navigation device mounted on a vehicle (automobile) comprises a main body mainly composed of a microcomputer, a display device, a GPS receiver, a map data device and the like. Then, the current position of the vehicle is measured based on the reception of radio waves from GPS satellites, and the location function for displaying the current position of the vehicle on the screen of the display device and displaying it on the map, and the recommended route to the destination designated by the user. It has functions such as route search and guidance for searching and guiding.

Of these, the Dijkstra method is generally used for calculating the route by the route search function. In short, this route calculation is based on the cost of the road (link) from the departure point (current position) to the destination and the next reachable intersection (node) according to the specified priority conditions. The calculation is performed sequentially, and the route with the lowest cost to the destination is selected. The cost is calculated by a predetermined calculation formula from the road length, road type, road width, toll free charge, congestion degree, right / left turn, and the like.

However, in the route search by the cost calculation as described above, depending on the weather condition at that time, a route which is not preferable to the user (driver) in terms of safety may be guided. For example, a bridge or mountain road that may freeze the road surface in winter may be selected as a route, or a lowland road that may be inundated (flooded) during rain or a mountain road that may collapse may be selected as a route. In some cases, the driver will be guided to the route that he or she originally wants to avoid.

Therefore, in the prior art, Japanese Patent Laid-Open No. 8-21086
As disclosed in Japanese Patent Publication No. 5, a raindrop sensor and a temperature sensor are provided in the antenna part of the GPS receiver, and when raindrops are detected by the raindrop sensor, a route search is performed so as to avoid a road narrower than a predetermined width. When the outside temperature is low (0 ° C. or less) by the temperature sensor, it is considered to perform route search so as to avoid a steep road. According to this, it is possible to carry out the route search considering the actual weather conditions to some extent.

However, in this configuration, two types of sensors must be newly provided to detect the weather condition, which results in an increase in cost, and in order to incorporate these sensors in the GPS antenna, However, there is a problem that the size and the like are limited, and it becomes impossible to mount a sensor with high accuracy, for example.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to perform a route search adapted to an actual weather condition without adding a new sensor for detecting the weather condition. To provide a car navigation device.

[0008]

The present inventors have found that
Focusing on the fact that some devices that operate in relation to weather conditions are installed, and by acquiring the operation information of these in-vehicle devices, it is possible to determine the actual weather conditions without using a new sensor. I confirmed and achieved the present invention. According to the first aspect of the invention, the motion information of the vehicle-mounted device that operates in relation to the weather condition is acquired by the motion information acquisition unit, the weather condition determination unit determines the weather condition from the motion information, and the route search unit determines the weather condition. The route search is performed by adding the conditions.

Therefore, according to the first aspect of the invention, the route search adapted to the actual weather condition can be carried out, and at this time, based on the operation information of the vehicle-mounted device which the vehicle originally has. Since the weather condition can be determined, it is not necessary to add a new sensor for detecting the weather condition.

In this case, more specifically, as the operation information of the vehicle-mounted device which operates in relation to the weather condition, the following items or a combination thereof can be adopted. That is,
Since the wiper device is operated at the time of rainfall and the operation speed of the wiper device at that time is determined according to the amount of rainfall, it is possible to determine the presence or absence of rainfall or the degree of rainfall by acquiring the operation information of the wiper device. The determination can be made with certainty, and the route search can be performed accordingly (the invention of claim 2).

Car air conditioners (for example, auto air conditioners)
In vehicles equipped with, the actual temperature outside the vehicle can be detected by the outside air temperature sensor of the car air conditioner. It is possible to make a determination in step (1), and a route search can be performed accordingly (invention of claim 3).

In a vehicle equipped with an ABS device, A
When the BS device operates frequently, it is considered that the road surface is likely to slip due to snow or freezing. Therefore, by acquiring the operation information, when the ABS device operates frequently, snow or the road surface freezes. Can be determined with sufficient certainty (claim 4
Invention).

In a vehicle having a fog lamp, the fog lamp is turned on when fog is generated. Therefore, it is possible to determine the fog occurrence with sufficient certainty by acquiring lighting information of the fog lamp. And the route search can be performed accordingly (invention of claim 5).

Then, the meteorological condition determining means causes rainfall,
When it is determined that the road surface is frozen, snow is accumulated, or fog is generated, it is possible to search for a safer route (the invention of claim 6). This will avoid areas (roads) where flooding or landslides may occur, such as when there is a large amount of rainfall, when the road surface is frozen or when there is snow, on bridges, mountain roads, narrow roads, steep slopes, etc. It is possible to select a route that is easier for the driver to drive according to the weather conditions, such as avoiding roads that have a high possibility of slipping, etc., and avoiding places (roads) that become dense fog such as mountain roads when fog occurs. .

Furthermore, the determined meteorological condition is not used only for the route search, but when the meteorological condition judging means judges any one of rainfall, freezing of the road surface, snow accumulation, and fog, Since the driver needs more attention than when driving in fine weather, the warning means can be configured to call the driver's attention when driving the vehicle (the invention of claim 7). As a result, the determined weather conditions are
It can be used more effectively, and the safety in running can be improved.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 schematically shows a system configuration in the present embodiment. This system is related to a car navigation device 1 according to the present embodiment mounted on a vehicle (automobile) and weather conditions mounted on the vehicle. A plurality of in-vehicle devices that operate in this manner, in this case, a wiper device 2, a car air conditioner (auto air conditioner) 3, an ABS device 4, and a fog lamp 5.

In the car navigation device 1, a navigation device body (navi ECU) 6 has a GPS receiver 7 for receiving a signal from a GPS satellite through a GPS antenna, for example, a position detecting sensor 8 including a gyro sensor and a vehicle speed sensor. For example, it is configured by connecting a display device 9 which is composed of a full color liquid crystal display and which displays a road map and the like. Although not shown, a touch panel functioning as an operation switch is provided on the surface of the display device 9, and the user inputs commands such as designation of a displayed map and designation (selection) of a destination for route search, etc. To be able to do.

A map data device 10 is built in the navigation device body 6. This map data device 10 is, for example, a DV that stores road map data.
It is composed of a map data source such as D or a hard disk and its drive device. The road map data reproduces (draws) the road shape, road width, road name, building, various facilities, their address, telephone number, place name, topography, etc., and the road map on the screen of the display device 9. And road data (link data) for route search (calculation).

Although not shown in detail, the navigation device body 6 is constituted by a microcomputer including a CPU, a ROM, a RAM, an input / output interface and a bus line connecting them, and its software configuration (program By executing), navigation processing such as a location function for knowing the current position of the vehicle, a route search for searching and guiding a route to a destination designated (searched) by the user, and a guidance function (route guidance function) are executed. ing. And this navigation device body 6
The wiper device 2, the car air conditioner 3, the ABS device 4, and the fog lamp 5 are connected to each other via a communication line or a radio wave via an in-vehicle communication system 11 as a communication means.
The operation information is input as will be described later.

FIG. 2 shows the navigation device body 6
However, the main part of the function realized by the software configuration (and the hardware configuration) is shown by a functional block. Of these, the GPS / gyro processing unit 12 uses the G
The GPS signal received by the PS receiver 7 and the detection signal of the position detection sensor 8 are processed, and the position calculation unit 13 calculates the current position (and traveling direction) of the vehicle with high accuracy based on these signals. It has become. Data of the current date and time can be obtained from the GPS signal, and part of the date data (seasonal data) is also used for the weather determination described later.

The calculated data such as the current position of the vehicle is
It is sent to the map drawing unit 14, and the map drawing unit 14 displays the road map around the current position of the vehicle on the display device 9 based on the road map data, and the current position of the own vehicle measured by superimposing it on the road map. Also, a pointer indicating the traveling direction is displayed. With this, the navigation device body 6, the GPS receiver 7, the position detection sensor 8 and the like constitute a position detection means, and the location function is realized.

Further, the route calculation unit 15 designates a recommended traveling route from the starting point (current position) of the vehicle to the destination designated (searched) by the user by using, for example, the well-known Dijkstra method. It automatically calculates according to the conditions (for example, toll road priority, general road priority, distance priority, etc.) and functions as a route search means. The route guidance unit 16 guides the user to the travel route calculated by the route calculation unit 15, and gives an instruction to the map drawing unit 14 to display the route on the screen of the display device 9 or to show the intersection. It is designed to give voice guidance in the front. With this, the functions of route search and guidance are realized.

Here, regarding the Dijkstra method used for the route search (route calculation) by the route calculation unit 15,
I will briefly explain. As described above, the map data device 10
The road map data stored in contains road data for route search. This road data is divided into a plurality of parts by dividing roads on the map into nodes such as intersections.
It is given as link data that defines the portion between each node as a link. This link data is the link ID,
The link length, link start point and end point position data, angle (direction) data, road width, road type, and other data are included.

Then, the route search is carried out at the place of departure (current position).
From the destination to the destination, the next intersection (node)
Of road (link) up to and its cost (evaluation value)
Is sequentially performed, and the route (link sequence) that minimizes the cumulative cost to the destination is selected. The cost of each link is calculated by a predetermined calculation formula from the road length, road type, road width, toll free classification, congestion degree, turning left and right, crossing level, etc. In the case of, the value becomes large in proportion to the road length.

At this time, in the present embodiment, the road data includes characteristic data associated with the weather condition of each road (link). This characteristic data is, for example, in the lowlands near rivers and the like, and is easily flooded (flooded).
There is a risk of landslides during heavy rain, the road surface is easy to freeze on bridges and mountain slopes (freezing is difficult to remove), thick fog is likely to occur on mountain roads, steep slopes, It is information that there are many mountain roads.

As will be described in detail later in the description of the operation (flowchart description), in the present embodiment, the navigation device body 6 has a software configuration (and a hardware configuration), in addition to the above-mentioned functions, Functions such as the communication processing unit 17, the weather determination unit 18, the traveling information storage unit 19, and the traveling warning unit 20 illustrated in FIG. 2 are realized.

Among them, the communication processing unit 17 communicates with the wiper device 2, the car air conditioner 3, the ABS device 4, and the fog lamp 5 via the in-vehicle communication system 11 and is related to the determination of weather conditions described later. The operation information to be performed is acquired from the in-vehicle devices 2-5. Further, the acquired motion information is notified to the weather determination unit 18. Therefore, the communication processing unit 17 functions as an operation information acquisition unit.

In this case, as the operation information, the wiper device 2 is provided with information on the presence or absence of the operation of the wiper device 2 and the speed thereof, and the car air conditioner 3 is provided with information on the outside of the car air conditioner 3. The temperature information detected by the air temperature sensor is provided, the ABS device 4 is provided with information indicating that the ABS device 4 has been operated, and the fog lamp 5 indicates whether the fog lamp 5 has been turned on. Information about the presence or absence is provided.

The weather determination unit 18 is adapted to determine the weather condition from the operation information of the vehicle-mounted devices 2 to 5 notified from the communication processing unit 17, and notifies the route calculation unit 15 of the determination result. It is like this. More specifically, the degree of rainfall (whether or not it is heavy enough to cause flooding or landslide) is determined from the operation information of the wiper device 2, and the road surface freezing condition is determined from the outside air temperature information of the car air conditioner 3. It is determined from the operation information of the ABS device 4 that the road surface is slippery due to snowfall or freezing when the operation frequency is high, and the occurrence of fog is determined from the lighting information of the fog lamp 5. Has become. Therefore, the weather determination unit 18 functions as weather condition determination means.

When the weather determining unit 18 determines whether the rainfall, the freezing of the road surface, the accumulation of snow, or the occurrence of fog, the route calculating unit 15 determines the route to reach the destination. In consideration of the above, a route with higher safety is searched for. In this case, when calculating the cost of the route by the above-described method, the route calculation unit 15 determines the cost of the link (road) corresponding to the weather condition when each link includes the characteristic data associated with the weather condition. The cost is increased (normal cost is multiplied by a predetermined coefficient). If the determination result by the weather determination unit 18 is notified while the route search is already performed and the route guidance is being executed, and if there is a road including the characteristic data in the route, the route is recalculated. It is supposed to be done.

Specifically, for example, when rainfall (heavy rain) is determined, the cost of roads having characteristic data such that water is easily inundated and there is a risk of landslides is increased, and those roads are prevented from passing as much as possible. , When the road surface is frozen or snow is determined, the cost of the road is increased as much as possible, and the cost of the road is increased as much as possible so that the road surface has a characteristic data that the road surface is easily frozen due to a bridge or hillside and the road surface is a steep slope. Do not pass, and when it is determined that fog has occurred, increase the cost of roads that have characteristic data such as dense fog on mountain roads, mountain roads with many curves, and prevent them from passing as much as possible, , It chooses the safest route (easy to drive for the driver).

Further, the judgment result of the weather judging unit 18 is notified to the running information storage unit 19, and information necessary for warning by the running warning unit 20 described below (heavy rain, freezing of the road surface, occurrence of fog, etc.). Information) is stored. Driving warning unit 20
Is based on the current position information from the position calculation unit 13 and the weather condition information stored in the travel information storage unit 19 when the vehicle passes a road requiring attention, A warning is given by a display or a synthesized voice to call the driver's attention on running. Therefore, the traveling warning unit 20 functions as a warning means.

Concretely, for example, when rainfall (heavy rain) is determined, "please be careful of flooding" when passing through a road that is prone to flooding or a road that may be landslide,
A warning such as "Be careful of landslides" is issued, and when a road is determined to be frozen, a warning such as "Be careful of freezing" when passing through a road that tends to freeze or a steep slope When it is determined that fog has occurred, a warning such as "There is a curve ahead" is issued when passing through a curved road. The warning by the traveling warning unit 20 is issued not only when the route guidance is being provided but also when the vehicle is normally running (when the location function is being performed) when the route guidance is not being provided.

Next, the operation of the above configuration will be described with reference to FIGS. The flowcharts of FIGS. 3 to 6 show the outline of the processing procedures executed by the weather determination unit 18, the route calculation unit 15, the traveling information storage unit 19, and the traveling warning unit 20 in the navigation device body 6, respectively. In addition, here, in order to avoid complication of the description, only a part of the processing (a portion related to rainfall and snowfall or road freezing in FIGS. 3 and 4, and a portion related to snowfall or road freezing in FIGS. 5 and 6) is performed. It is shown, and the rest of the drawing is omitted.

When the car navigation system 1 is powered on, as shown in FIG. 2, the current position and traveling direction of the vehicle are detected by the position calculator 13 and the map drawing unit 14 is detected.
In addition to the above, a location function is executed to display the current position and the traveling direction on the screen of the display device 9 by superimposing the road map around the current position of the vehicle. At the same time, the communication processing unit 17 constantly monitors the operation information of the wiper device 2, the car air conditioner 3, the ABS device 4, and the fog lamp 5, and the operation information of any one of them is transmitted via the in-vehicle communication system 11. If received (acquired),
The weather determination unit 18 executes the process of the procedure shown in the flowchart of FIG.

That is, when the operation information is received (Yes in step S1), it is determined in the next step S2 whether or not the operation information is the operation information of the wiper apparatus 2. If the operation information is the operation information of the wiper apparatus 2, (Yes in step S2
s), in step S3, it is determined whether the operating speed of the wiper device 2 is a medium speed or higher. If it is medium speed or higher (Yes in step S3), it is determined to be rain (heavy rain), and 1 is set to the variable Fwiper indicating the degree of rainfall (step S4). When the speed is not medium speed or higher (No in step S3), it is determined that the amount of rain is small, and the variable Fwi
0 is set in per (step S5). The value of the variable Fwiper is normally 0.

On the other hand, when the received operation information is not the operation information of the wiper device 2 (N in step S2)
o) In step S6, it is determined whether or not it is the operation information of the ABS device 4. If it is the operation information of the ABS device 4 (Yes in step S6), the variable Fabs indicating the operation frequency of the ABS device 4 is incremented (step S7). If the received operation information is not the operation information of the ABS device 4 (No in step S6), another process is performed in step S8. Although detailed description is omitted, in step S8, the generation of fog or the like is determined from the lighting information of the fog lamp 5 as described above.

Thus, from the operation information of the wiper device 2, the car air conditioner 3, the ABS device 4, and the fog lamp 5, which are in-vehicle devices that operate in relation to the weather conditions, the weather determination unit 18
The weather conditions can be determined with sufficient certainty. In this case, the vehicle-mounted device 2 originally provided in the vehicle
Since the weather condition can be determined based on the operation information of 5 to 5, it is not necessary to add a new sensor for detecting the weather condition. As shown in FIG. 2, the weather condition determined by the weather determination unit 18 is notified to the route calculation unit 15 and the traveling information storage unit 19.

Here, when the user (driver) wants to calculate and guide the optimum traveling route from the current position to the destination by using the route searching and guiding functions of the car navigation system 1, Operate the operation switch,
Specify the route search command and also enter the destination and priority conditions. Then, the route calculation unit 15 of the navigation device body 6 executes the process of the procedure shown in the flowchart of FIG. 4 to search (calculate) the recommended route.

That is, in the route search, from the starting point (current position) to the destination (step S11), appropriate roads are sequentially searched from the road data and candidate roads to the destination are selected (step S11). S12), the route having the minimum cost by the cost calculation is selected as the recommended route (step S20). At this time, when the road data of the candidate road includes characteristic data, the cost of the road is changed as follows based on the above-mentioned weather conditions (variable Fwiper and variable Fabs).

First, in step S13, it is determined whether or not the road data has characteristic data such that water is likely to be flooded or there is a possibility of landslide. If yes (Yes), the variable Fwiper is determined in step S14. Is determined to be 1. If the variable Fwiper is 1, (Y
es), in the next step S15, the cost of the road is increased. If there is no characteristic data (No in step S13) and if the variable Fwiper is 0 (No in step S14), step S16 is performed as it is.
Proceed to.

In step S16, it is determined whether or not the road data has characteristic data of freezing caution (such as freezing or steep slopes), and if it exists (Yes), the season data is determined in step S17. Is determined to be winter, and if it is determined to be winter (Yes), it is determined in step S18 whether the variable Fabs is equal to or greater than a predetermined value, for example, 10. If the variable Fabs is 10 or more (Yes), the cost of the road is increased in the next step S19. If there is no characteristic data (step S1)
No in 6) and if there is no winter (No in step S17), the variable Fabs is 9 even in winter.
In the following cases (No in step S18), the process directly proceeds to step S20.

As a result, when the wiper device 2 is operated at a medium speed or higher and rainfall (heavy rain) is determined, the cost of the road having characteristic data such as easy inundation and risk of landslide is increased, Routes with higher safety will be selected without passing through those roads as much as possible. Also, AB
When the operation frequency of the S device 4 is high and it is determined that the road surface is frozen or is covered with snow, the cost of the road that has characteristic data such as a steep slope or a slope on a bridge or a mountain slope increases. Therefore, routes with higher safety are selected without passing through those roads as much as possible.

Although the cost is increased in steps S15 and S19, it goes without saying that in some cases the road must be selected. Although not shown in the figure, when the weather determination unit 18 determines that fog is generated, the cost of the road having characteristic data such that the fog tends to be thick and the road is a mountain road with many curves is increased. The route with the highest safety is selected without passing through the road as much as possible.
Then, after this route search, route guidance by the route guidance unit 16 is executed.

Next, the flow chart of FIG. 5 shows a part of the processing executed by the running information storage section 19 (only the section related to snowfall or road surface freezing). As described above, the traveling information storage unit 19 stores the information necessary for the warning by the traveling warning unit 20 based on the determination of the weather determination unit 18. That is, in step S21, it is determined whether or not the variable Fabs is greater than or equal to the predetermined value (10), and when the variable Fabs is 10 or more (Yes), it is determined in the next step S22 whether or not it is winter. If it is winter (Yes), the data of the current position and the code of freezing caution are stored in step S23. Although illustration is omitted, similarly, information on the occurrence of rainfall (heavy rain) and fog is also stored.

The traveling warning unit 20 warns the driver according to the procedure shown in the flowchart of FIG. That is, first, in step S31, it is determined whether or not there is freezing caution characteristic data on the road on which the vehicle is traveling, and if it is present (Yes), step S32.
At, it is determined whether the freeze caution code is stored. If the freeze caution code is present (Yes in step S32), a warning such as "please be careful of freeze" is issued in step S33.

Although not shown in the drawing, similarly, even when heavy rain or fog occurs, as described above, "please be careful of flooding", "be careful of landslides",
A warning such as "There is a curve ahead" is given.
As a result, it is possible to call the driver's attention while driving, and it is possible to enhance the driving safety. in this case,
The weather condition determined by the weather determination unit 18 can be effectively used not only for route search but also for such warning.

As described above, according to this embodiment, the wiper device 2, the car air conditioner 3 and the ABS originally mounted on the vehicle are installed.
When determining the weather condition based on the operation information of the in-vehicle device such as the device 4 and the fog lamp 5 and performing the route search, it is necessary to select the route as safe and easy for the driver as possible according to the weather condition. Since it is configured as described above, unlike a conventional GPS antenna part provided with a raindrop sensor and a temperature sensor to determine the weather,
It has an excellent effect that a route search adapted to actual weather conditions can be performed without adding a new sensor for detecting the weather conditions.

Further, particularly in the present embodiment, the determined weather condition is not used only for the route search, but the driver is warned based on the weather condition, so that the determination is made. It is possible to use the meteorological conditions more effectively and to obtain the merit that the driving safety can be improved.

Although the operation information is obtained from all of the wiper device 2, the car air conditioner 3, the ABS device 4, and the fog lamp 5 in the above embodiment, the weather condition is determined from some of the operation information. The present invention can be applied to a vehicle that is not equipped with all of them. In addition, the warning associated with the determination of the weather conditions may be performed as necessary, and may be omitted. The present invention is not limited to the above-described embodiment and does not depart from the scope of the invention. Can be appropriately changed and implemented.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention and schematically showing the overall configuration of a system.

FIG. 2 is a functional block diagram showing functions realized by the navigation device body.

FIG. 3 is a flowchart showing a processing procedure in a weather determination unit.

FIG. 4 is a flowchart showing a processing procedure in a route calculation unit.

FIG. 5 is a flowchart showing a processing procedure in a traveling information storage unit.

FIG. 6 is a flowchart showing a processing procedure in a traveling warning unit.

[Explanation of symbols]

In the drawings, 1 is a car navigation device, 2 is a wiper device, 3 is a car air conditioner, 4 is an ABS device, 5 is a fog lamp, 6 is a navigation device body, 9 is a display device, 1
1 is an in-vehicle communication system, 13 is a position calculation unit (position detection unit), 15 is a route calculation unit (route search unit), 17 is a communication processing unit (motion information acquisition unit), and 18 is a weather determination unit (weather condition determination unit). ), 20 is a traveling warning unit (warning means).

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2C032 HB22 HC08 HC13 HC31 HD03                       HD21 HD24                 2F029 AA02 AB01 AB07 AB13 AC02                       AC04 AC08 AC13 AC14                 5H180 AA01 BB13 BB15 EE12 FF04                       FF05 FF22 FF27 FF33

Claims (7)

[Claims] 1. A car navigation device mounted on a vehicle, comprising position detecting means for detecting the current position of the vehicle, and route searching means for searching for a recommended route to a destination based on road map data. And an operation information acquisition unit that acquires operation information of the in-vehicle device that operates in relation to the weather condition, and a weather condition determination unit that determines the weather condition from the operation information of the in-vehicle device acquired by the operation information acquisition unit. A car navigation device comprising: and a route search unit configured to perform a route search in consideration of the determination made by the weather condition determination unit. 2. The operation information of the vehicle-mounted device comprises operation information of a wiper device, and the weather condition determination means determines the presence or absence of rainfall or the degree of rainfall from the operation information. The car navigation device described. 3. The operation information of the vehicle-mounted device comprises outside air temperature information of a car air conditioner, and the weather condition determination means determines the freezing condition of the road surface from the outside air temperature information. Car navigation equipment. 4. The operation information of the in-vehicle device includes operation information of an ABS device, and the meteorological condition determination means sets the A
The car navigation system according to claim 1, wherein snowfall or freezing of a road surface is determined when the operation frequency of the BS system is high. 5. The car navigation system according to claim 1, wherein the operation information of the vehicle-mounted device includes lighting information of a fog lamp, and the meteorological condition determining unit determines whether fog is generated from the lighting information. . 6. The route search means searches for a safer route when the weather condition determination means determines any one of rainfall, road surface freezing, snow accumulation, and fog. The car navigation device according to any one of claims 1 to 5. 7. A warning means is provided for urging the driver to be careful when driving the vehicle when it is determined by the meteorological condition determination means that it is raining, freezing the road surface, snow, or fog. The car navigation device according to any one of claims 1 to 6.