JP2009237739A - Road surface freeze forecasting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a road surface freeze forecasting system that accurately forecasts whether road surface in frozen in a specific location predicted to be frozen from relationships between meteorological conditions and freeze stored for the specific location. <P>SOLUTION: An in-vehicle apparatus 12 mounted on a vehicle 11 and an information center 13 store weather information and freeze information for a specific location predicted to freeze in association with each other. Specifically, past weather changes to road surface freeze are stored as freeze management data. A freeze forecasting part of the information center 13 collates current weather information for the specific location with the stored freeze management data to forecast whether the road surface is frozen in the specific location in consideration of the past weather changes. The information center 13 then sends the forecast to the in-vehicle apparatus 12 mounted on the vehicle. The freeze of the specific location can be forecasted on the vehicle 11. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a road surface freezing prediction device that predicts freezing at a specific position on a road.

Conventionally, it has been proposed to predict a phenomenon that adversely affects the running of a vehicle, such as freezing of a road surface. For example, in the case of Patent Literature 1, road surface freezing is predicted using the correlation between outside air temperature and freezing at a point indicating a specific attribute such as a bridge.
Japanese Patent Laid-Open No. 2001-165679

However, the possibility of road surface freezing varies greatly depending on individual structures and individual environments, even for structures that show the same attributes. In addition, whether or not freezing occurs, such as changes in temperature and weather from a few days ago, depends on the weather conditions up to that point. Therefore, as in Patent Document 1, there is a problem that the accuracy is not sufficient even if the presence / absence of freezing is predicted using the contribution level determined for each attribute.
Therefore, the present invention has been made in view of the above-described problems, and the purpose of the present invention is to freeze the road surface at a specific position from the relationship between the weather conditions accumulated at the specific position where the road surface is expected to freeze and the freezing. An object of the present invention is to provide a road surface freezing prediction device that predicts presence or absence with high accuracy.

  In the invention described in claim 1, weather information and freezing information at a specific position where road surface freezing is predicted are stored in association with the information storage means. Therefore, past changes in weather until the road surface freezes are accumulated as freeze management data. Thereby, a prediction means predicts the presence or absence of freezing by collating with the freezing management data accumulate | stored from the present weather information in a specific position. Therefore, not only the current weather and the attribute of the specific position but also the past weather change until freezing can be taken into consideration, and the presence or absence of freezing of the road surface can be predicted with high accuracy.

In the invention according to claim 2, in addition to notifying that the specific position is frozen, the notifying means searches for and notifies a route that bypasses the specific position. Therefore, the user can predict the presence or absence of freezing at a specific position and can select a detour that avoids the specific position where freezing is predicted. Therefore, danger can be avoided in advance, and safety in operation of the vehicle can be improved.
In the invention according to claim 3, the prediction means predicts the presence or absence of freezing by comparing with the freezing management data based on the current outside air temperature at the specific point. Therefore, the presence or absence of freezing at a specific position is predicted based on the freezing management data accumulated in the past and the current outside air temperature. Therefore, the presence or absence of freezing at a specific position can be predicted with higher accuracy.

  In the invention according to claim 4, the freezing detection means detects the freezing of the road surface based on the behavior of the vehicle. That is, when freezing is detected by the behavior of the vehicle, the position information at the frozen position and the frozen position weather information are added as new specific positions, and these pieces of information are accumulated. For this reason, information is newly accumulated as a specific position at a point where freezing management data has not been accumulated in the past as a specific position, triggered by the detection of freezing. Therefore, road surface freezing at a new specific position can be predicted.

Hereinafter, an embodiment of a road surface freezing prediction apparatus according to the present invention will be described with reference to the drawings.
A road surface freezing prediction device according to an embodiment of the present invention is shown in FIG. A road surface freezing prediction device 10 shown in FIG. 1 includes a navigation device (hereinafter referred to as “on-vehicle device”) 12 and an information center 13 mounted on a vehicle 11.
(In-vehicle device)
First, the in-vehicle device 12 shown in FIG. 2 will be described. The in-vehicle device 12 is mounted on the vehicle 11. The in-vehicle device 12 includes a control unit 14, a position detection unit 15, a map data input unit 16, an operation switch unit 17, an external memory 18, a display unit 19, a voice controller 21, a remote control sensor 22, and an outside air temperature sensor 23. The control unit 14 is mainly configured by a microcomputer having a CPU, a ROM, and a RAM (not shown).

  The position detection unit 15 detects the current position of the vehicle 11. The position detection unit 15 includes a geomagnetic sensor 24, a gyroscope 25, a distance sensor 26, and a GPS receiver 27. The geomagnetic sensor 24 detects the direction of the vehicle 11. The gyroscope 25 detects the rotation angle of the vehicle 11. The distance sensor 26 detects the travel distance of the vehicle 11. The GPS receiver 27 receives radio waves transmitted from GPS satellites in order to determine the current position of the vehicle 11 by GPS (Global Positioning System).

  The map data input unit 16 has a map data storage medium and a drive device (not shown). Map data storage media include road map data, landmark data, map matching data, destination data, table data for converting traffic information into road data, etc. formed by a plurality of nodes and links connecting the nodes. Various data are stored. The drive device reads out various data stored in the map data storage medium. The map data read from the map data input unit 16 is stored in a RAM (not shown) of the control unit 14. As the map data storage medium, for example, a large-capacity storage medium such as a DVD or CD, or a storage medium such as a memory card or a hard disk drive is used.

  The operation switch unit 17 includes a mechanical switch provided in the vicinity of the screen of the display unit 19 and a touch panel switch provided on the screen of the display unit 19. The user uses the switches of the operation switch unit 17 to switch the destination of the vehicle 11 and the screen and display mode of the display unit 19 (for example, change of map scale, selection of menu display, route search, route guidance). Input of various commands to start the operation, correct the current position and adjust the volume. Thereby, the vehicle-mounted apparatus 12 operate | moves according to a user's instruction | indication. The remote control sensor 22 transmits and receives commands and the like to and from the remote control 28. The remote controller 28 is provided with a plurality of operation switches. By operating the operation switch of the remote controller 28, various command signals are transmitted from the remote controller 28 via the remote controller sensor 22 to the control unit 14. The operation switch unit 17 and the remote controller 28 can cause the control unit 14 to execute the same function by any operation.

  The external memory 18 is configured by, for example, a removable flash memory card or a hard disk drive. The external memory 18 constitutes information storage means in the claims. The display unit 19 has a color liquid crystal display, for example. On the screen of the display unit 19, a map around the current position of the vehicle 11 is displayed at various scales, and a current location mark indicating the current position and the traveling direction of the vehicle 11 is displayed on the map display. When performing route guidance to the destination, a screen for route guidance is displayed on the screen of the display unit 19. The external memory 18 may be shared with, for example, a RAM or an EEPROM provided in the control unit 14 of the in-vehicle device 12.

  The voice controller 21 is connected to the in-vehicle speaker 29. The voice controller 21 outputs a voice recognition result to the control unit 14 via the microphone connection unit when a vehicle-mounted microphone (not shown) is connected. At the same time, the voice controller 21 outputs the recognized voice as a talkback via the in-vehicle speaker 29. The voice controller 21 outputs a voice output signal to the in-vehicle speaker 29 based on a voice output command from the control unit 14. The sound output from the vehicle-mounted speaker 29 is a sound related to guidance, a sound related to operation explanation, a sound notifying that the anti-theft function is operating, a talkback sound corresponding to a sound recognition result, and the like.

  The microcomputer constituting the control unit 14 stores map data for the navigation function in a memory composed of a RAM or EEPROM (not shown). The control unit 14 displays a road map around the current location on the screen of the display unit 19 so that the vehicle 11 can move along the travel route, and also displays a current location mark indicating the position and traveling direction of the vehicle 11 on the road map. Overlaid on the display. In this case, the display of the current location moves on the displayed map as the vehicle 11 travels, and the map is scroll-displayed according to the position of the vehicle 11. At this time, the control unit 14 performs map matching that matches the current location of the vehicle 11 on the road.

  The in-vehicle device 12 includes a freezing information acquisition unit 31. The freeze information acquisition unit 31 is connected to a traction control unit 32 mounted on the vehicle 11. The traction control unit 32 detects a rotation speed difference between a driving wheel and a driven wheel (not shown) of the vehicle 11 or a steering angle by a steering sensor (not shown). The traction control unit 32 calculates a turning radius predicted for the vehicle 11 and a turning radius predicted from the difference in the number of rotations of the inner and outer wheels of the driving wheel and the driven wheel based on the difference in rotation speed or the steering angle. Calculate and detect slips such as idling and skidding of each wheel of the vehicle 11 from the difference between the turning radii. And the traction control part 32 commands increase / decrease in the output to the engine control apparatus which is not shown based on the detected slip of each wheel. The in-vehicle device 12 acquires slip information of each wheel from the traction control unit 32 via the freezing information acquisition unit 31. The freezing information acquisition part 31 acquires the freezing information which concerns on the presence or absence of road surface freezing based on the slip information of each wheel. Therefore, the freezing information acquisition unit 31 constitutes a freezing information acquisition unit and a freezing detection unit.

  The in-vehicle device 12 includes an outside air temperature sensor 23. The outside air temperature sensor 23 detects the outside air temperature of the vehicle 11 on which the in-vehicle device 12 is mounted. That is, the outside air temperature sensor 23 constitutes outside air temperature acquisition means in the scope of claims. The outside air temperature sensor 23 outputs the detected temperature to the control unit 14 as an electrical signal. The control unit 14 detects the temperature outside the vehicle 11, that is, the outside air temperature, based on the electrical signal output from the outside air temperature sensor 23. The in-vehicle device 12 includes a communication unit 33. The communication unit 33 communicates with the information center 13 via a wired or wireless communication line 34.

(Information Center)
Next, the information center 13 will be described. The information center 13 is composed of a facility that transmits road information such as VICS, or an information transmission facility that is operated by each vehicle manufacturer. The information center 13 includes a server 41 as information storage means for storing information. The server 41 includes a control unit 42 configured by a computer system such as a CPU, ROM, and RAM (not shown) and a large-capacity storage unit 43 that accumulates information. In addition to the server 41, the information center 13 includes a communication unit 44, a weather information acquisition unit 45, a freezing prediction unit 46, and a notification unit 47. The communication unit 44 communicates with the in-vehicle device 12 via a wired or wireless communication line 34.

  The weather information acquisition unit 45 acquires weather information at a specific position where road surface freezing is predicted. The weather information acquisition unit 45 acquires weather information from a weather station provided at a specific position. Moreover, the weather information acquisition part 45 may acquire weather information not only from a specific position but from the weather station provided in the vicinity of a specific position, or the weather station of the area containing a specific position. In this case, by accumulating the weather information acquired from the weather station provided near the specific location or the weather facility including the specific area, the weather information acquired at the weather facility and the presence or absence of freezing at the specific location The correlation is also accumulated. Moreover, the weather information acquisition part 45 may detect freezing of the road surface in a specific position.

  The storage unit 43 constitutes information storage means in the claims, and stores the weather information acquired by the weather information acquisition unit 45. Further, the control unit 42 of the information center 13 acquires the freeze information from the freeze information acquisition unit 31 of the vehicle 11 via the communication line 34. The control unit 42 creates freezing management data by associating the weather information acquired by the weather information acquisition unit 45 with the freezing information acquired from the freezing information acquisition unit 31 of the vehicle 11, and accumulates the generated freezing management data in the storage unit 43. To do. In this freezing management data, weather information at a specific position where the road surface is expected to freeze is associated with the presence or absence of road surface freezing at this specific position.

  The freeze management data has a structure as shown in FIG. That is, the freeze management data includes date and time, direction, road surface freezing level, weather information at the time of detection, and past weather information. The freezing management data includes position information of a specific position in addition to the date / time, direction, road surface freezing level, weather information at the time of detection, and past weather information. Freezing management data is created for each specific position where freezing is expected, such as “specific position A”, “specific position B”. The “date and time” included in the freezing management data is the date and time when the direction, road surface freezing level, weather information, and the like are acquired at each specific position. The “direction” included in the freezing management data is the traveling direction when the vehicle 11 passes the specific position. As for the traveling direction, traveling from the starting point side to the ending point side set for each road is the forward direction, and conversely, traveling from the ending point side to the starting point side is the reverse direction. This is because even on the same road, there is a difference in the degree of road surface freezing or the position where road surface freezing occurs between the forward lane in the forward direction and the upstream lane in the reverse direction. Therefore, the freeze management data includes the traveling direction of the vehicle 11. The “road surface freezing level” included in the freezing management data is literally the level of road surface freezing at a specific position. The road surface freezing level is set at a plurality of stages such as high, medium, and low, for example, the slipperiness associated with road surface freezing. The road surface freezing level is determined from the slip state of the vehicle 11 acquired by the freezing information acquisition unit 31 of the in-vehicle device 12. The road surface freezing level is not limited to three stages, and can be set to any stage of two or more stages.

  The “weather information at the time of detection” included in the freeze management data is literally weather information at a specific position at the time of detection. Of the “weather information at the time of detection”, the latest weather information currently acquired corresponds to the current weather information. The weather information at the time of detection includes “weather”, “outside temperature”, “rainfall” and the like at a specific position. The “weather”, “outside temperature”, and “rainfall” were acquired from the weather facility at the specific location acquired by the weather information acquisition unit 45, the weather facility near the specific location, or the local weather facility that includes the specific location. Based on weather information. Here, as the “outside air temperature”, a value detected by the outside air temperature sensor 23 of the vehicle 11 traveling in a specific position may be used. “Past weather information” included in the freeze management data is past weather information accumulated as weather information at a specific position. “Past weather information” includes “weather”, “outside temperature”, “rainfall”, and the like, similarly to “weather information at the time of detection”. In the case of the freeze management data shown in FIG. 3, the “past weather information” includes the transition of the weather information at the specific position for the past five hours every hour. The structure of the above-mentioned freeze management data is only an example. Therefore, the past weather information to be accumulated and items included in the weather information can be arbitrarily changed, and items included in the freezing management data can be arbitrarily set.

  Based on the current weather information acquired by the weather information acquisition unit 45, the freezing prediction unit 46 predicts the presence or absence of road surface freezing at a specific position from the freezing management data stored in the storage unit 43. The possibility of road surface freezing at a specific position varies greatly depending not only on current weather information but also on past weather changes. For example, even if the current temperature is 0 ° C. or lower, road surface freezing does not always occur at a specific position when the temperature of the previous day or several hours ago is relatively high. The possibility of road surface freezing also changes depending on the weather at a specific position. For example, the temperature rises when it is sunny in the daytime, whereas the temperature drops greatly by so-called radiative cooling when it is sunny at night. Thus, the possibility of road surface freezing changes according to the weather up to now. Therefore, the freezing prediction unit 46 refers to the relationship between the past weather information stored in the storage unit 43 and the freezing information based on the current weather information acquired by the weather information acquisition unit 45, and the road surface at the specific position. Presence of freezing. In addition, when the vehicle includes the outside air temperature sensor 23, the freezing prediction unit 46 predicts the presence or absence of freezing at the specific position using the outside air temperature at the specific position acquired by the outside air temperature sensor 23.

  The notification unit 47 notifies the in-vehicle device 12 of the predicted result when the freeze prediction unit 46 predicts that there is freezing at the specific position. The notification unit 47 transmits the determination result of the freeze prediction unit 46 to the in-vehicle device 12 via the communication line 34. The in-vehicle device 12 that has received the determination result from the notification unit 47 of the information center 13 displays, for example, a mark indicating that freezing is predicted at a specific position on the map displayed on the screen of the display unit 19, or audio To inform.

Next, the flow of operation by the road surface freezing prediction apparatus 10 having the above configuration will be described.
(Accumulation of frozen information)
First, the flow of acquiring freeze information at a specific position using the vehicle 11 will be described with reference to FIG.
The in-vehicle device 12 detects the outside air temperature while the vehicle 11 is traveling (S101). The in-vehicle device 12 detects the outside air temperature constantly or at predetermined intervals while the vehicle 11 is traveling. That is, when the air conditioner is mounted on the vehicle 11, the air conditioner always detects the outside air temperature and the room temperature in order to maintain the interior of the vehicle at a comfortable temperature. The in-vehicle device 12 detects the current outside air temperature from the outside air temperature sensor 23 shared with the air conditioner.

  The in-vehicle device 12 acquires past weather information (S102). The in-vehicle device 12 periodically acquires weather information at the current traveling point. The acquired weather information is stored in the external memory 18 of the in-vehicle device 12 for each point where the vehicle is traveling. As described above, the weather information is acquired by the weather information acquisition unit 45 of the information center 13. This weather information is not limited to weather information at a specific position where freezing is expected, but is often weather information of a region including this specific position. In this case, the weather information is updated, for example, every hour or every few hours. Therefore, the in-vehicle device acquires weather information representative of each running point updated every hour to several hours from the information center 13 and accumulates it in the external memory 18. The in-vehicle device 12 acquires the weather information from the information center 13 via the communication line 34.

The in-vehicle device 12 detects the current position and the traveling direction of the vehicle 11 (S103). The in-vehicle device 12 detects the current position and traveling direction of the vehicle 11 by the position detection unit 15. The in-vehicle device 12 acquires the current position of the vehicle 11 detected by the position detection unit 15 as position information. Here, as the traveling direction, traveling from the starting point side to the ending point side set for each road is defined as the forward direction, and conversely, traveling from the ending point side to the starting point side is defined as the reverse direction.
When the detection of the outside air temperature in step S101, the acquisition of the past weather information in step S102, and the detection of the current position and traveling direction in step S103 are completed, the in-vehicle device 12 determines whether or not road surface freezing has been detected ( S104). The in-vehicle device detects road surface freezing based on the slip state of each wheel of the vehicle 11 acquired from the freezing information acquisition unit 31.

  When the road surface freezing is not detected in step S104, the in-vehicle device 12 detects whether or not a predetermined point has been passed (S105). Here, the preset point corresponds to a specific position where road surface freezing has been detected in the past. As shown in FIG. 5, it is assumed that the vehicle 11 travels on a route L1 from the current location P1 to the destination P2. A mountainous area M1 and a river M2 exist between the current location P1 and the destination P2. The route L1 includes a point (specific position) B that is expected to freeze in the mountainous area M1 and a point C that is expected to freeze in the bridge Br crossing the river M2. The point B of the mountainous area M1 where the freezing is expected and the point C of the bridge Br crossing the river M2 are points as specific positions where freezing is expected.

When detecting the road surface freezing in step S104, the in-vehicle device 12 stores the position information of the point where the road surface freezing is detected, the road surface freezing information, the traveling direction and the past weather information in the external memory 18 (S106). The in-vehicle device 12 detects the presence / absence of road surface freezing in step S104 and stores the road surface freezing state in the external memory 18 as road surface freezing information.
On the other hand, when the road surface freezing is not detected in step S104, the in-vehicle device 12 detects whether or not the points B and C set in advance as described above, that is, whether or not the specific position is passed. At a specific position, since road surface freezing has been detected in the past, there is a high possibility that road surface freezing will occur again depending on weather conditions. Therefore, the in-vehicle device 12 registers the points B and C at which road surface freezing is detected as specific positions. Further, when a slip accompanying freezing of the road surface is detected by the vehicle 11 equipped with the in-vehicle device 12 at a point other than the points B and C that have already been registered, the position where the slip has occurred is added as a specific position. When the in-vehicle device 12 detects a new freezing point, the detected point is added as a specific position, and the weather information acquisition unit 45 acquires the weather information at the detected new point. In this case, the control unit 14 also functions as a specific position adding unit in claims, and the weather information acquisition unit 45 also functions as a frozen position weather information acquisition unit in claims.

  By the way, in a specific position where road surface freezing is expected, the possibility of road surface freezing changes depending on weather conditions. Therefore, when the in-vehicle device 12 detects the points B and C set in advance in step S105, that is, the passage of the specific position, the position information and road surface of each point in step S106 regardless of whether or not the road surface is frozen at points B and C. Freezing information, traveling direction, outside air temperature, and past weather information are stored in the external memory 18. As described above, by accumulating these pieces of information regardless of the presence or absence of road surface freezing, the accuracy of determining whether or not road surface freezing occurs at a specific position under what weather conditions is improved.

When the in-vehicle device 12 stores each information in the external memory 18 in step S106, the in-vehicle device 12 transmits the stored information to the information center 13 (S107). The information center 13 stores each information transmitted from the in-vehicle device 12 in the storage unit 43 (S108). As a result, various types of information acquired by the in-vehicle device 12 are stored not only in the in-vehicle device 12 but also in the information center 13. Therefore, the information accumulated in the information center 13 is provided not only to the specific vehicle 11 on which the in-vehicle device 12 is mounted, but also to other vehicles that pass through the specific position. For example, each data acquired at points B and C in FIG. 5 is accumulated in the external memory 18 and the storage unit 43 as the freeze management data shown in FIG.
Freezing information is accumulated by the above procedure.

(Prediction of road surface freezing)
Next, a flow for predicting road surface freezing will be described with reference to FIG.
When predicting road surface freezing, the in-vehicle device 12 detects the outside air temperature (S201). As described above, the in-vehicle device 12 acquires the outside air temperature constantly or periodically from the outside air temperature sensor 23 shared with the air conditioning equipment of the vehicle 11. At the same time, the in-vehicle device 12 acquires past weather information (S202). Past weather information is also acquired in the same manner as the above-described flow of freezing information accumulation. Further, the in-vehicle device 12 detects the current position and the traveling direction of the vehicle 11 (S203). The detection of the current position and the traveling direction of the vehicle 11 is also acquired in the same manner as the flow of freezing information accumulation described above.

  The in-vehicle device 12 determines whether or not there is route guidance when the acquisition of the outside air temperature, the weather information, the current position, and the traveling direction is completed (S204). That is, the in-vehicle device 12 determines whether or not to perform route guidance using its own navigation function. When it is determined in step S204 that the route guidance is “Yes”, that is, the route guidance is to be executed, the in-vehicle device 12 determines whether or not the route for executing the route guidance has a specific position for predicting road surface freezing (S205). ). For example, in the case of the example shown in FIG. 5, it is determined whether or not the points B and C that are specific positions are included in the route L1 on which the route guidance is executed. Further, the in-vehicle device 12 determines that the route guidance is “None” in step S204, that is, the route guidance is not executed, and in step S205, the route on which the route guidance is performed has no specific position for predicting road surface freezing. Then, it is determined whether or not there is a specific position for predicting road surface freezing near the current position where the vehicle 11 is traveling (S206).

  When the in-vehicle device 12 determines in step S205 that there is a specific position for predicting road surface freezing on the route on which the route guidance is executed, and the specific position for predicting road surface freezing is in the vicinity of the current position where the vehicle 11 is traveling. When it is determined that there is a road surface freezing prediction at the point, that is, a specific position, based on a predetermined algorithm (S207). The in-vehicle device 12 transmits the weather information acquired by the weather information acquisition unit 45 to the information center 13 sequentially or periodically. The freezing prediction unit 46 of the information center 13 is based on the weather information acquired from the weather information acquisition unit 45, the outside temperature acquired from the in-vehicle device 12 via the communication line 34, the current position, the traveling direction, and the like. Predicts road surface freezing in The prediction of road surface freezing uses an algorithm that takes into account the current outside air temperature at a specific location and accumulated past weather information. For example, even if the current outside air temperature detected by the outside air temperature sensor 23 of the in-vehicle device 12 is 0 ° C. or more, if the air temperature in the past several hours is 0 ° C. or less, the possibility of road surface freezing is high. Also, if there has been rainfall or snowfall in the past few hours, there is a high possibility of road surface freezing even if the current outside air temperature is relatively high. Therefore, the freeze prediction unit 46 predicts the presence or absence of road surface freezing at a specific position by adding past weather information to the current outside air temperature.

  When the freezing prediction unit 46 determines that there is a possibility of road surface freezing at the specific position, the notification unit 47 of the information center 13 determines whether the prediction result notification by the freezing prediction unit 46 is necessary (S208). ). When the notification unit 47 determines that the notification of the prediction result is necessary, the notification unit 47 transmits the determination result of the freezing prediction unit 46 to the in-vehicle device 12 via the communication line 34. The in-vehicle device 12 that has received the determination result from the notification unit 47 of the information center 13 displays a mark indicating that road surface freezing is predicted, for example, superimposed on a specific position on the map displayed on the screen of the display unit 19. . When the road surface freeze at a specific position is predicted during the search for the guidance route, the notification unit 47 displays the specific position on the screen to call attention. In addition, when the road surface freeze at a specific position is predicted during the search for the guidance route, the notification unit 47 may set a detour route that bypasses the specific position. Furthermore, when road surface freezing at a specific position on the route is predicted while the vehicle 11 is traveling, attention may be urged by voice or an image when the vehicle 11 approaches the specific position. In addition, the search for the detour may be configured to search not by the notification unit 47 but by a route search unit (not shown) of the in-vehicle device 12 based on information provided from the notification unit 47.

  As described above, in one embodiment of the present invention, the external memory 18 of the in-vehicle device 12 and the storage unit 43 of the information center 13 store the weather information and the frozen information in a specific position in association with each other. Therefore, past changes in weather until the road surface freezes are accumulated as freeze management data. Thereby, the freezing prediction part 46 predicts the presence or absence of road surface freezing in a specific position by collating with the freezing management data accumulate | stored from the present weather information in a specific position. Therefore, not only the current weather and the attribute of the specific position, but also the past weather change until freezing can be taken into consideration, and the presence or absence of road surface freezing can be predicted with high accuracy.

In addition, the freezing prediction unit 46 predicts the presence or absence of freezing by collating with freezing management data based on the current outside air temperature at a specific point. Therefore, the presence or absence of freezing at a specific position is predicted based on the freezing management data accumulated in the past and the current outside air temperature. Therefore, the presence or absence of freezing at a specific position can be predicted with higher accuracy.
Moreover, in one Embodiment of this invention, the alerting | reporting part 47 alert | reports the detour route which bypasses a specific position in addition to the alert | report of the freezing of a specific position. Therefore, the user can select the detour route that avoids the specific position where freezing is predicted while predicting the presence or absence of freezing at the specific position. Therefore, danger can be avoided in advance and safety in operation of the vehicle 11 can be improved.

  In one embodiment of the present invention, the freezing information acquisition unit 31 of the in-vehicle device 12 detects the freezing of the road surface from the behavior of the vehicle 11 based on the slip state of each wheel of the vehicle 11 detected by the traction control unit 32. When the traction control unit 32 detects freezing based on the behavior of each wheel of the vehicle 11, the position information at the frozen position and the frozen position weather information are newly added as specific positions. For this reason, information is newly accumulated as a specific position even when the freezing management data has not been accumulated in the past as the specific position, triggered by the detection of freezing. Therefore, road surface freezing at a new specific position can be predicted.

(Other embodiments)
In the embodiment of the present invention described above, the example in which the road surface freezing prediction device 10 is configured from the in-vehicle device 12 and the information center 13 has been described. In the embodiment of the present invention, an example in which road surface freezing is predicted by the information center 13 while detecting the presence or absence of road surface freezing or the outside air temperature at a specific position by the in-vehicle device 12 has been described. However, the road surface freezing prediction device 10 that is completed by the in-vehicle device 12 may be configured without providing the information center 13. For example, various types of information detected by the outside air temperature sensor 23 and the freeze information acquisition unit 31 of the in-vehicle device 12 and the weather information acquired for each specific position are stored in the external memory 18 of the in-vehicle device 12. And it is good also as a structure which provides the freezing prediction part in the vehicle equipment 12, and predicts road surface freezing in a specific position based on the various data which this freezing prediction part accumulate | stored in the external memory 18. FIG. Thereby, the vehicle-mounted device 12 itself can predict road surface freezing at a specific position without providing the information center 13. In addition, the freeze prediction unit 46 is provided not only in the information center 13 but also in the in-vehicle device 12, and the prediction of the road surface freezing is performed by combining the prediction of the road surface freezing by the information center 13 and the prediction of the road surface freezing by the in-vehicle device 12. Good.

Furthermore, the roles of the in-vehicle device 12 and the information center 13 are not limited to the above example, and may be arbitrarily shared. For example, the information center 13 may simply store and provide information, and the in-vehicle device 12 may perform prediction of road surface freezing.
The present invention described above is not limited to the above-described embodiment, and can be applied to various embodiments without departing from the gist thereof.

Schematic which shows the structure of the road surface freezing prediction apparatus by one Embodiment of this invention. The block diagram which shows the structure of the road surface freezing prediction apparatus by one Embodiment of this invention. The schematic diagram which shows the data structure of the freezing management data of the road surface freezing prediction apparatus by one Embodiment of this invention Schematic which shows the flow of accumulation | storage of freezing information in the road surface freezing prediction apparatus by one Embodiment of this invention. Schematic diagram showing an example of the route from the current location of the vehicle to the destination Schematic which shows the flow of the prediction of road surface freezing in the road surface freezing prediction apparatus by one Embodiment of this invention.

Explanation of symbols

  In the drawings, 10 is a road surface freezing prediction device, 11 is a vehicle, 13 is an information center, 15 is a position detection unit, 18 is an external memory (information storage means), 23 is an outside air temperature sensor (outside air temperature acquisition means), and 31 is freezing. Information acquisition unit (freezing information acquisition unit, freezing detection unit), 43 is a storage unit (information storage unit), 45 is a weather information acquisition unit (weather information acquisition unit, frozen position weather information acquisition unit), 46 is a freezing prediction unit ( (Predicting means) 47 is a notification unit.

Claims (4)

A road surface freezing prediction device for predicting road freezing on a road,
Weather information acquisition means for acquiring weather information at a specific position where road surface freezing is expected;
Freezing information acquisition means for acquiring, as freezing information, whether or not the road surface is frozen at the specific position when the vehicle passes through the specific position;
Information storage means for storing the weather information acquired by the weather information acquisition means and the freezing information acquired by the freezing information acquisition means in association as freezing management data;
Prediction means for predicting the presence or absence of freezing at the specific position based on the current weather information acquired by the weather information acquisition means and the freezing management data stored in the information storage means;
Informing means for informing the vehicle of freezing of the specific position by the predicting means when the predicting means predicts that there is freezing at the specific position;
A road surface freezing prediction device comprising:   The road surface freezing prediction apparatus according to claim 1, wherein the notification unit searches and notifies a route that bypasses the specific position in addition to the notification of freezing of the specific position. An outside air temperature acquisition means for acquiring the current outside air temperature at the specific position;
The prediction unit predicts the presence or absence of freezing at the specific position based on the freezing management data stored in the information storage unit and the outside air temperature acquired by the outside air temperature acquiring unit. The road surface freezing prediction apparatus as described. Freezing detection means for detecting freezing of the road surface from the behavior of the vehicle,
When detecting the freezing of the road surface by the freezing detection means, a position detection means for detecting the position of the frozen road surface as a freezing position;
Frozen position weather information acquisition means for acquiring weather information at the frozen position detected by the position detection means;
Specific position adding means for adding the frozen position detected by the position detecting means to the specific position;
The road surface freezing prediction apparatus according to claim 1, 2, or 3.

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