JP2018040744A - Navigation device and route setting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a navigation device and a route setting method that can set a route down to a destination in accordance with a level of travelling difficulty closer to reality.SOLUTION: A navigation device comprises: a travelling difficulty level judgement unit 102 that judges a travelling difficulty level of roads on the basis of rainfall information, and any one of gradient information and geological information; and a route setting unit 103 that sets routes down to a destination on the basis of the travelling difficulty level judged by the travelling difficulty level judgement unit 102. Accordingly, the travelling difficulty level to be judged is configured to be appropriate in consideration for an actual rainfall state, a gradient level of a road surface and geology of the road surface which greatly affect an actual road surface state, and the route down to the destination is set based on the appropriate travelling difficulty level in accordance with the actual road surface state.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a navigation device and a route setting method, and is particularly suitable for use in a navigation device and a route setting method configured to set a route to a destination on the basis of road travel difficulty.

  Conventionally, in a navigation device, heavy rain information is received by “VICS WIDE”, a service provided by VICS (registered trademark) (Vehicle Information and Communication System), and based on this heavy rain information, a region where heavy rain is falling is mapped Technologies that display on the screen or search for a route to a destination while avoiding an area where heavy rain falls are used. According to this technique, it is possible to provide a user with a route that is easier to travel.

  In addition, Patent Document 1 listed below includes a predetermined condition (required time, traffic volume (large, medium, small), intersection (left turn count, straight turn count, right turn count) according to the purpose of the practice as well as the departure point and arrival point. ) Etc.) is input as a search condition, and a technique for searching and displaying a driving practice course having a difficulty level that matches the search condition is disclosed. According to this technique, it is possible to obtain an optimal practice course that matches a user's physical strength and skill only by inputting a search condition.

JP 2003-114608 A

  However, the actual road may become muddy or slippery, and the road surface condition may change depending on the weather conditions at that time. Nevertheless, the conventional technique has a problem that the difficulty level of the route cannot be determined according to the change in the state of the road surface. For this reason, for example, when searching for a route to the destination, it is preferable to present the user with a route that is easy for the user to run, but actually presents the user with a route that is difficult to run due to poor road surface conditions. There is a risk that. In addition, in an off-road course, for users who are immature in driving skills, a course with a high degree of difficulty is actually presented due to bad road surface conditions, or for users who request a course with a high degree of difficulty, In reality, there is a possibility that a route whose degree of difficulty is increased to the level requested by the user may not be presented.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to be able to set a route to a destination according to a more realistic travel difficulty level. To do.

  In order to solve the above-described problems, in the present invention, the road travel difficulty level is determined based on rainfall information and at least one of slope information and geological information. Based on the travel difficulty determined in this way, a route to the destination is set.

  According to the present invention configured as described above, the actual rainfall situation, the slope of the road surface, and the geology of the road surface are considered in which the degree of travel difficulty to be determined has a great influence on the actual road surface condition. It will be appropriate. For this reason, the route to the destination is set based on the appropriate degree of travel difficulty according to the actual road surface condition. Therefore, according to the present invention, the route to the destination can be set according to the travel difficulty that is closer to reality.

It is a block diagram which shows the function structural example of the navigation apparatus which concerns on 1st Embodiment of this invention. It is a figure which shows an example of the determination conditions which the navigation apparatus concerning 1st Embodiment of this invention uses. It is a flowchart which shows an example of the process by the navigation apparatus concerning 1st Embodiment of this invention. It is a figure which shows the example of a route setting by the navigation apparatus which concerns on 1st Embodiment of this invention. It is a block diagram which shows the function structural example of the navigation apparatus which concerns on 2nd Embodiment of this invention. It is a flowchart which shows an example of the process by the navigation apparatus concerning 2nd Embodiment of this invention. It is a figure which shows the example of a route setting by the navigation apparatus which concerns on 2nd Embodiment of this invention.

[First Embodiment]
[Functional configuration example of navigation device]
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a first embodiment of the invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a functional configuration example of a navigation device 10 according to the first embodiment of the present invention. A navigation device 10 shown in FIG. 1 is a navigation device mounted on a vehicle such as an automobile. In addition, the navigation apparatus of this invention is not limited to what is mounted in the vehicle, For example, you may be implement | achieved by the portable terminal (a smart phone, a mobile telephone, a tablet terminal etc.) which the passenger | crew of a vehicle possesses.

  As shown in FIG. 1, the navigation device 10 includes a map data storage unit 11, a vehicle position detection device 12, a display 13, a speaker 14, and a determination condition storage unit 15. Moreover, the navigation apparatus 10 is provided with the information acquisition part 101, the travel difficulty determination part 102, the route setting part 103, and the route guidance part 104 as the function structure.

  Each of the functional blocks 101 to 104 can be configured by any of hardware, DSP (Digital Signal Processor), and software. For example, when configured by software, each of the functional blocks 101 to 104 is actually configured by including a CPU, RAM, ROM, etc. of a computer, and a program stored in a recording medium such as RAM, ROM, hard disk, or semiconductor memory. Is realized by operating.

  The map data storage unit 11 stores map data. The map data includes road data of a plurality of roads. Each road data includes information such as nodes and links. In addition to the link cost, each link includes slope information representing the slope of the road surface and geological information representing the geology of the road surface.

  The own vehicle position detection device 12 detects the current position of the vehicle on which the navigation device 10 is mounted. The own vehicle position detection device 12 includes, for example, a GPS (Global Positioning System) and an autonomous navigation unit.

  The display 13 displays various information (for example, a map screen, a route guidance screen, etc.). As the display 13, for example, a liquid crystal display, an organic EL display, or the like is used. The speaker 14 outputs various voices (for example, route guidance voice).

  The determination condition storage unit 15 stores various determination conditions for determining the road travel difficulty level. In the present embodiment, the determination condition storage unit 15 stores “cumulative precipitation”, “tilt”, “geology”, and “difficulty determination” as determination conditions for determining the road travel difficulty level. The details of the determination conditions stored in the determination condition storage unit 15 will be described later with reference to FIG.

  The information acquisition unit 101 includes a rainfall information acquisition unit 101a and a road surface information acquisition unit 101b. The rainfall information acquisition unit 101a acquires rainfall information. For example, the rainfall information acquisition unit 101a acquires heavy rain information provided by “VICS WIDE”, which is a VICS service, as rainfall information. The road surface information acquisition unit 101b acquires inclination information and geological information for each road. For example, the road surface information acquisition unit 101b acquires inclination information and geological information for each road from the map data stored in the map data storage unit 11. In the present embodiment, the road surface information acquisition unit 101b acquires the slope information and the geological information only when it is specified that there is rainfall by the rainfall information or when there is rainfall within a predetermined time until now. Yes.

  The travel difficulty level determination unit 102 determines the travel difficulty level of each road based on the rainfall information acquired by the rainfall information acquisition unit 101a and the slope information and geological information acquired by the road surface information acquisition unit 101b. Specifically, the travel difficulty level determination unit 102 determines the travel difficulty level for each road according to the following procedure. In the present embodiment, the travel difficulty level determination unit 102 determines the travel difficulty level of each road only when the rainfall information specifies that there is rainfall.

  First, the travel difficulty level determination unit 102 is based on the determination condition stored in the determination condition storage unit 15 (“cumulative precipitation” in FIG. 2A), and the accumulated precipitation (for example, The added point a to be added is determined according to the accumulated precipitation amount for a predetermined time until now.

  Further, the travel difficulty level determination unit 102 corresponds to the road surface inclination specified by the inclination information based on the determination condition ("inclination" in FIG. 2B) stored in the determination condition storage unit 15. A point b to be added is determined.

  In addition, the travel difficulty level determination unit 102 corresponds to the drainage degree of the road surface specified by the geological information based on the determination condition (“geology” in FIG. 2C) stored in the determination condition storage unit 15. A point c to be added is determined.

  Then, the travel difficulty level determination unit 102 obtains the total points by adding the added points a, b, and c, and determines the determination conditions stored in the determination condition storage unit 15 ("" in FIG. 2D). Based on the “difficulty level determination”), the travel difficulty level (for example, “low”, “medium”, or “high”) corresponding to the total score is determined as the travel difficulty level of the road.

  The route setting unit 103 determines the purpose based on the travel difficulty level determined by the travel difficulty level determination unit 102 when the rainfall information identifies that there is rainfall, or when there is rainfall within a predetermined time until the present time. Set up a guide route to the ground. Specifically, the route setting unit 103 uses the vehicle position detection device 12 based on the map data stored in the map data storage unit 11 and the travel difficulty level determined by the travel difficulty level determination unit 102. A route from the detected current position of the vehicle to the destination is searched, and a guidance route searched by this is set.

  In the present embodiment, the route setting unit 103 determines the travel difficulty level when it is specified that there is rainfall by the rainfall information acquired by the rainfall information acquisition unit 101a, or when there is rainfall within a predetermined time until now. The guide route searched based on the search condition weighted by the travel difficulty determined by the unit 102 is set. In particular, in the present embodiment, the route setting unit 103 sets a guide route with the lowest travel difficulty determined by the travel difficulty determination unit 102.

  For example, the route setting unit 103 weights the cost for each link by using a weight value corresponding to the travel difficulty determined by the travel difficulty determination unit 102 for each road. Thereby, the search cost of each route is calculated. At this time, the route setting unit 103 weights each link only with a weight value corresponding to the travel difficulty level. In this way, the route setting unit 103 searches for a route having the lowest search cost, and sets the searched route thus searched.

  When the rain information acquired by the rain information acquisition unit 101a specifies that there is no rain, the route setting unit 103 selects a route based on normal search conditions (for example, distance priority, time priority, etc.). A search is performed, and the searched guidance route is set.

  The route guidance unit 104 is a guide route set by the route setting unit 103 based on the map data stored in the map data storage unit 11 and the current position of the vehicle detected by the host vehicle position detection device 12 as needed. To guide you. For example, the route guidance unit 104 displays a route guidance screen on the display 13 or outputs a route guidance voice from the speaker 14.

[Example of judgment conditions]
FIG. 2 is a diagram illustrating an example of determination conditions used by the navigation device 10 according to the first embodiment of the present invention. As shown in FIG. 2, the determination condition storage unit 15 stores “cumulative precipitation”, “tilt”, “geology”, and “difficulty determination” as determination conditions for determining the road travel difficulty level. ing.

  In the determination condition “cumulative precipitation” shown in FIG. 2A, a determination condition is set such that the greater the amount of accumulated precipitation specified by the rainfall information, the larger the added points, that is, the higher the difficulty of travel. ing. In addition, in the determination condition “inclination” shown in FIG. 2B, a determination condition is set such that the higher the degree of inclination of the road surface specified by the inclination information, the larger the added points, that is, the higher the difficulty of traveling. Has been. In addition, in the determination condition “geology” shown in FIG. 2 (c), a determination condition is set such that as the degree of drainage of the road surface specified by the geological information is worse, the added points are larger, that is, the traveling difficulty is higher. Has been. Further, in the determination condition “difficulty level determination” shown in FIG. 2D, a determination condition is set such that the higher the total score of the above three points, the higher the traveling difficulty level.

  Based on these determination conditions “cumulative precipitation”, “inclination”, and “geology”, the travel difficulty level determination unit 102 is specified by the added point a to be added according to the accumulated precipitation specified by the rainfall information and the inclination information. The added point b to be added according to the slope of the road surface to be added and the added point c to be added according to the degree of drainage of the road surface specified by the geological information are respectively determined. Then, the traveling difficulty level determination unit 102 calculates the total points by adding the determined added points a, b, and c, and based on the determination condition “difficulty level determination” shown in FIG. A travel difficulty level corresponding to the total score is determined.

[Example of processing by navigation device 10]
FIG. 3 is a flowchart showing an example of processing by the navigation device 10 according to the first embodiment of the present invention. The process illustrated in FIG. 3 is executed, for example, at a timing when the user performs a request operation for a route to the destination (for example, an operation for selecting a route search button) on the navigation device 10.

  First, the rainfall information acquisition unit 101a acquires rainfall information (step S302). Next, based on the rainfall information acquired in step S302, the travel difficulty level determination unit 102 determines whether there is rainfall or whether there has been rainfall within a predetermined time until now (step S304). .

  If the travel difficulty level determination unit 102 determines that there is rain or rain (step S304: Yes), the road surface information acquisition unit 101b acquires slope information and geological information of each road (step S308). ). Then, the travel difficulty level determination unit 102 determines the road travel difficulty level based on the rainfall information acquired by the rainfall information acquisition unit 101a and the slope information and geological information acquired by the road surface information acquisition unit 101b ( Step S310). Further, the route setting unit 103 searches for and sets a route based on the search condition with priority on the travel difficulty based on the travel difficulty determined in step S310 (step S312). Then, the route setting unit 103 presents the route set in step S312 to the user by displaying the route on the display 13 (step S314). Thereafter, the navigation device 10 advances the processing to step S316.

  On the other hand, when it is determined in step S304 that there is no rain and the travel difficulty level determination unit 102 determines that there is no rain (step S304: No), the route setting unit 103 searches for and sets a route based on normal search conditions (step S306). ). Then, the route setting unit 103 presents the route set in step S306 to the user by displaying it on the display 13 (step S314). Thereafter, the navigation device 10 advances the processing to step S316.

  In step S316, the route guidance unit 104 determines whether or not the user has approved that the route presented to the user in step S314 is applied to route guidance to the destination. Here, when the route guidance unit 104 determines that the user approves the application of the route presented to the user to the route guidance to the destination (step S316: Yes), the route guidance unit 104 determines that the purpose of the route is Route guidance to the ground is performed (step S318). And the navigation apparatus 10 complete | finishes a series of processes shown in FIG. On the other hand, when the route guidance unit 104 determines that the user has not approved that the route presented to the user is applied to the route guidance to the destination (step S316: No), the navigation device 10 performs the series shown in FIG. Terminate the process.

  Note that the processing of FIG. 3 can be applied not only when the route is set for the first time but also when the route is searched again during route guidance. For example, the route may be re-searched automatically when the rainfall situation changes during route guidance. For example, during the route guidance by the route searched when there is no rain, the rainfall information is repeatedly acquired until the arrival at the destination, and the presence or absence of the rain is determined. If it is determined that there is rainfall based on the latest rainfall information, the route may be re-searched by executing the processing after step S308.

[Route setting example by the navigation device 10]
FIG. 4 is a diagram illustrating a route setting example by the navigation device 10 according to the first embodiment of the present invention. FIG. 4 shows an example in which the route setting unit 103 searches for a route from the current position S of the vehicle to the destination G and sets it as a guidance route. FIG. 4A shows an example of a route searched and set by the route setting unit 103 when there is no rain. FIG. 4B shows an example of a route searched and set by the route setting unit 103 when there is rain.

  As illustrated in FIG. 4A, when it is specified that there is no rain according to the rain information, the route setting unit 103 determines whether the vehicle is based on normal search conditions (for example, distance priority, time priority, etc.). A route from the current position S to the destination G is searched and set. In the example shown in FIG. 4A, the route setting unit 103 searches for and sets a route passing through the section R1 between the point P1 and the point P2 based on normal search conditions.

  On the other hand, as illustrated in FIG. 4B, when it is specified that there is rainfall by the rainfall information, the route setting unit 103 is based on the driving difficulty level of each road determined by the driving difficulty level determination unit 102. Thus, a route from the current position S of the vehicle to the destination G is searched and set. In particular, the route setting unit 103 searches and sets a route with the lowest travel difficulty. In the example shown in FIG. 4B, a route passing through the section R <b> 2 between the point P <b> 1 and the point P <b> 2 based on the driving difficulty level of each road determined by the route setting unit 103 by the route setting unit 103. Is searched and set.

  Here, the travel difficulty level determination unit 102 determines the travel difficulty level of each road based on the accumulated precipitation amount, the slope of the road surface, and the drainage degree of the road surface. In the example of FIG. 4B, it is assumed that the accumulated rainfall and the slope of the road surface do not change between the road of the section R1 and the road of the section R2, but the drainage of the road surface is different. The section R1 is a section that mainly passes through an area where the geology is red soil. The section R2 is a section that passes through a region where the geology is mainly gravel. The area where the geology is gravel has better drainage than the area where the geology is red soil, so it is hard to get muddy during rainfall. For this reason, the travel difficulty level determination unit 102 determines the travel difficulty level of the road in the section R2 that passes mainly on the area where the geology is gravel rather than the road of the section R1 that passes mainly on the area where the geology is red soil. Judge low. Therefore, in the example of FIG. 4B, the route setting unit 103 searches and sets the route passing through the section R2 on the region where the geology is gravel as the route having the lowest travel difficulty. .

  As described above, according to the first embodiment of the present invention, an actual rainfall situation in which the travel difficulty level determined by the travel difficulty level determination unit 102 has a great influence on the actual road surface condition, It is appropriate considering the slope and the geology of the road surface. For this reason, when it rains, the route setting unit 103 searches for and sets a route to the destination based on an appropriate travel difficulty level according to the actual road surface condition. Therefore, according to the first embodiment of the present invention, a route to the destination can be set according to a travel difficulty that is closer to reality.

  In addition, according to the first embodiment, only the weight value based on the travel difficulty level is set as the link cost, and the route with the lowest search cost is searched and set. An optimal route can be presented to the user.

  In the first embodiment, at the time of rain, only the guidance route searched based on the search condition weighted by the travel difficulty is presented to the user, but the present invention is not limited to this. For example, when it is raining, the guide route searched based on the search condition weighted by the travel difficulty level and the guide route searched based on the normal search condition (for example, distance priority, time priority, etc.) are given to the user. It may be presented to allow the user to select which guidance route to apply to route guidance.

  Moreover, in 1st Embodiment, although the route setting part 103 weights only the weight value according to a travel difficulty level with respect to each link, this invention is not limited to this. For example, the route setting unit 103 weights each link with a weight value according to a travel difficulty level in addition to a weight value according to a normal search condition (for example, distance priority, time priority, etc.). Also good.

  In the first embodiment, for each of a plurality of routes, the travel difficulty level of the route may be determined as follows.

  First, the travel difficulty level determination unit 102 determines the travel range degree of each link on the basis of the determination condition of FIG. Then, the average value of the weight values is calculated by dividing the total value of the weight values calculated as described above by the number of links constituting the route, and based on the average value, the travel difficulty level of the route is calculated as follows: Any one of “low”, “medium”, and “high” may be determined. In this case, the average travel difficulty level of all sections in the route is reflected in the travel difficulty level of the route.

  In addition, based on the highest weight value among a plurality of weight values calculated for a plurality of links, one of “low”, “medium”, and “high” is determined as the travel difficulty of the route. Also good. In this case, the travel difficulty of the section with the worst road surface condition on the route is reflected in the travel difficulty of the route.

[Second Embodiment]
Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. In the second embodiment, an example will be described in which, on an off-road course, a travel difficulty level of each of a plurality of predetermined routes is determined, and a route to be set is selected from the plurality of routes. In particular, in the second embodiment, the elements used for determining the travel difficulty level are changed according to the presence or absence of rainfall.

[Functional Configuration Example of Navigation Device 10 ']
FIG. 5 is a block diagram showing a functional configuration example of the navigation device 10 ′ according to the second embodiment of the present invention. The navigation device 10 ′ shown in FIG. 5 includes a map data storage unit 11 ′ instead of the map data storage unit 11, a point including a travel difficulty level determination unit 102 ′ instead of the travel difficulty level determination unit 102, and It differs from the navigation device 10 of the first embodiment in that a route setting unit 103 ′ is provided instead of the route setting unit 103.

  The map data storage unit 11 'stores a plurality of predetermined routes in the off-road course. As shown in FIG. 7, the off-road course has an annular shape, and the start point S and the goal point G are the same point. In addition, the map data storage unit 11 ′ stores inclination information and geological information for each link of each route in such an off-road course.

  The travel difficulty level determination unit 102 'determines the travel difficulty level for a plurality of predetermined routes. At this time, the travel difficulty level determination unit 102 ′ changes an element used for determination of the travel difficulty level according to the presence or absence of rainfall specified by the rainfall information. Specifically, the travel difficulty level determination unit 102 ′ determines the travel difficulty level of each route based on the slope information when the rain information specifies that there is no rain. On the other hand, the travel difficulty level determination unit 102 ′ is based on the rainfall information, the inclination information, and the geological information when it is specified that there is rainfall by the rain information, or when there is rain within a predetermined time until now. The travel difficulty level of each route is determined.

  The route setting unit 103 ′ sets a route in which the travel difficulty level determined by the travel difficulty level determination unit 102 matches the travel difficulty level desired by the user among a plurality of routes. For example, it is assumed that there are predetermined routes A, B, and C, and the “difficulty”, “intermediate”, and “advanced” are determined as the travel difficulty by the travel difficulty determination unit 102 ′, respectively. Further, it is assumed that “intermediate” is set in advance as a travel difficulty level desired by the user and stored in the memory. In this case, the route setting unit 103 ′ selects and sets the route B that matches the travel difficulty desired by the user.

  Here, for example, the route setting unit 103 ′ determines the travel difficulty level (any one of “Beginner”, “Intermediate”, and “Advanced”) for each of a plurality of routes as follows.

  First, the route setting unit 103 ′ calculates a weight value corresponding to the travel difficulty level determined by the travel difficulty level determination unit 102 for each of a plurality of links constituting the route. Then, the route setting unit 103 ′ calculates the total value of the weight values of a plurality of links constituting the route. Then, the route setting unit 103 ′ determines any one of “Beginner”, “Intermediate”, and “Advanced” as the travel difficulty level of the route based on the calculated total value of the weight values.

  Note that the method for determining the travel difficulty of each route is not limited to this. For example, the average value of the weight values is calculated by dividing the total weight value calculated as described above by the number of links constituting the route, and the travel difficulty level of the route is calculated based on the average value. As an alternative, one of “beginner”, “intermediate”, and “advanced” may be determined. In this case, the average travel difficulty level of all sections in the route is reflected in the travel difficulty level of the route.

  Also, based on the highest weight value among a plurality of weight values calculated for a plurality of links, one of “beginner”, “intermediate”, and “advanced” is determined as the travel difficulty level of the route. May be. In this case, the travel difficulty of the section with the worst road surface condition on the route is reflected in the travel difficulty of the route.

[Example of processing by the navigation device 10 ']
FIG. 6 is a flowchart showing an example of processing by the navigation device 10 ′ according to the second embodiment of the present invention. The process shown in FIG. 6 is executed, for example, at the timing when the user performs a request operation (for example, an operation for selecting a route selection button) of a desired difficulty level on the off-road course to the navigation device 10 ′. . In executing the following processing, the difficulty level desired by the user is set in advance by the user and stored in the memory.

  First, the rainfall information acquisition unit 101a acquires rainfall information (step S602). Next, the travel difficulty level determination unit 102 ′ determines whether there is rainfall or whether there has been rainfall within a predetermined time until now based on the rainfall information acquired in step S602 (step S604). ).

  Here, when the travel difficulty level determination unit 102 'determines that there is rain (step S604: Yes), the road surface information acquisition unit 101b acquires inclination information and geological information of each route (step S610). Then, the travel difficulty level determination unit 102 'determines the travel difficulty level of each route based on the rainfall information acquired in step S602 and the slope information and geological information acquired in step S610 (step S612). Further, the route setting unit 103 ′ sets a route in which the travel difficulty determined in step S 612 matches the travel difficulty desired by the user among the plurality of routes (step S 614). Then, the route setting unit 103 ′ presents the route set in step S 614 to the user by displaying it on the display 13 (step S 616). Thereafter, the navigation device 10 ′ advances the process to step S <b> 618.

  On the other hand, when the driving difficulty level determination unit 102 'determines that there is no rain in step S604 (step S604: No), the road surface information acquisition unit 101b acquires inclination information of each route (step S606). Then, the travel difficulty level determination unit 102 'determines the travel difficulty level of each route based on the inclination information acquired in step S606 (step S608). Further, the route setting unit 103 ′ sets a route in which the travel difficulty level determined in step S <b> 608 matches the travel difficulty level desired by the user among a plurality of routes (step S <b> 614). Then, the route setting unit 103 ′ presents the route set in step S 614 to the user by displaying it on the display 13 (step S 616). Thereafter, the navigation device 10 ′ advances the process to step S <b> 618.

  In step S618, the route guidance unit 104 determines whether or not the user has approved that the route presented to the user in step S616 is applied to the route guidance. Here, when the route guidance unit 104 determines that the user has approved the application of the route presented to the user in step S616 to the route guidance (step S618: Yes), the route guidance unit 104 performs route guidance based on this route. (Step S620). Then, the navigation device 10 'ends the series of processes shown in FIG. On the other hand, when the route guidance unit 104 determines that the user has not approved that the route presented to the user in step S616 is applied to the route guidance (step S618: No), the navigation device 10 ′ performs the series shown in FIG. Terminate the process.

  Note that the process of FIG. 6 can be applied not only when the route is initially set, but also when the route is reselected during route guidance. For example, the route may be automatically reselected when the rainfall situation changes during the route guidance. For example, during the route guidance according to the route selected when there is no rain, the rainfall information is repeatedly acquired to determine whether there is rain. Then, when it is determined that there is rainfall based on the latest rainfall information, the route may be reselected by executing the processing after step S610.

[Route setting example by the navigation device 10 ']
FIG. 7 is a diagram showing a route setting example by the navigation device 10 ′ according to the second embodiment of the present invention. FIG. 7 shows an example in which the route from the start point S to the goal point G on the off-road course is selected and set by the route setting unit 103 ′. FIG. 7A shows an example of a route selected and set by the route setting unit 103 ′ when there is no rain. FIG. 7B shows an example of a route selected and set by the route setting unit 103 when there is rain. Here, it is assumed that “intermediate” as the degree of difficulty desired by the user is preset by the user and stored in the memory.

  As shown in FIG. 7, a plurality of routes R1 to R7 exist in the off-road course, and the plurality of routes R1 to R7 are stored in the map data storage unit 11 '. For example, two routes R1 and R2 exist between the start point S and the point P1. Further, there are four routes R3, R4, R5, R6 and a point P2 between the point P1 and the point P3. The route R3 is a route from the point P1 to the point P3. Routes R4 and R5 are routes from point P1 to point P2. The route R6 is a route from the point P2 to the point P3. Further, a route R7 exists between the point P3 and the goal point G.

  As illustrated in FIG. 7A, when it is specified that there is no rain according to the rain information, the travel difficulty level determination unit 102 ′ determines each route R1 to R7 based on the inclination information of each route R1 to R7. The travel difficulty level (“Beginner”, “Intermediate”, or “Advanced”) is determined. Then, the route setting unit 103 ′ sets a route in which the travel difficulty level determined by the travel difficulty level determination unit 102 ′ matches the travel difficulty level desired by the user from among the plurality of routes R <b> 1 to R <b> 7. For example, as described above, when the travel difficulty level desired by the user is “intermediate”, the route setting unit 103 ′ determines that the travel difficulty level is determined as “intermediate” by the travel difficulty level determination unit 102 ′. A route passing through R2, R5, R6 and R7 is set.

  On the other hand, as illustrated in FIG. 7B, when the rain information specifies that there is rain or that rain has occurred within a predetermined time until now, the travel difficulty level determination unit 102 ′ Based on the information and the inclination information and geological information of each of the routes R1 to R7, the travel difficulty level (“Beginner”, “Intermediate”, or “Advanced”) of each of the routes R1 to R7 is determined. Then, the route setting unit 103 ′ sets a route in which the travel difficulty level determined by the travel difficulty level determination unit 102 ′ matches the travel difficulty level desired by the user from among the plurality of routes R <b> 1 to R <b> 7. For example, as described above, when the travel difficulty level desired by the user is “intermediate”, the route setting unit 103 ′ determines that the travel difficulty level is determined as “intermediate” by the travel difficulty level determination unit 102 ′. A route passing through R2, R5, R6, and R7 and a route passing through routes R2, R3, and R7 are selected. When a plurality of routes are selected in this way, for example, the user may be allowed to select which route is actually set.

  Here, the driving difficulty of route R3 is “Beginner” when there is no rain, but it changes to “Intermediate” when there is rain because of the geology (red soil) with poor drainage. This is because it is easy to get muddy when it rains. On the other hand, the driving difficulty of the route R4 is “beginner” when there is no rain, whereas it remains “beginner” when there is rain because of the geology (gravel) with good drainage. This is because it is difficult to get muddy when it rains.

  As described above, according to the second embodiment of the present invention, the elements used for the determination of the travel difficulty level are changed according to the presence or absence of rain, and particularly when there is rain for each of the routes R1 to R7. In addition to the slope, cumulative precipitation and road surface geology that has a significant effect on the actual road surface condition are added to the determination of the driving difficulty level. Therefore, the appropriate driving difficulty level is determined according to the actual road surface condition. be able to. Further, according to the second embodiment of the present invention, since a route that matches the travel difficulty level desired by the user is set, an optimal route suitable for the user's driving level can be presented to the user.

  In each of the above embodiments, the road travel difficulty level is determined based on slope information and geological information in addition to rainfall information, but the present invention is not limited to this. That is, the road travel difficulty level may be determined based on either slope information or geological information in addition to rainfall information.

  Moreover, in each said embodiment, although the road difficulty of a road is determined in three steps based on the accumulated precipitation specified by rainfall information, this invention is not limited to this. For example, the road travel difficulty level may be determined in five stages based on the presence or absence of rainfall specified by the rainfall information.

  In addition, each of the above-described embodiments is merely an example of implementation in carrying out the present invention, and the technical scope of the present invention should not be construed in a limited manner. That is, the present invention can be implemented in various forms without departing from the gist or the main features thereof.

DESCRIPTION OF SYMBOLS 10,10 'Navigation apparatus 11, 11' Map data memory | storage part 12 Own vehicle position detection apparatus 13 Display 14 Speaker 15 Judgment condition memory | storage part 101 Information acquisition part 102,102 'Traveling difficulty determination part 103,103' Route setting part 104 Route guide

Claims (10)

A travel difficulty level determination unit that determines a road travel difficulty level based on rainfall information and at least one of slope information and geological information;
A navigation device comprising: a route setting unit that sets a route to a destination based on the travel difficulty level determined by the travel difficulty level determination unit. The route setting unit
If the rain information specifies that there is no rain, set the route searched based on normal search conditions,
When it is specified by the rainfall information that there is rainfall or rain has occurred within a predetermined time until now, a search is performed based on the search condition weighted by the travel difficulty determined by the travel difficulty determination unit. The navigation device according to claim 1, wherein a navigation route is set. The route setting unit
The navigation apparatus according to claim 2, wherein a route having the lowest travel difficulty determined by the travel difficulty determination unit is set. The travel difficulty level determination unit
The element used for determination of the said travel difficulty is changed among the said rain information, the said inclination information, and the said geological information according to the presence or absence of the rain specified by the said rain information. Navigation device. The travel difficulty level determination unit
When it is specified that there is no rain according to the rain information, the travel difficulty level is determined based on the tilt information,
When it is specified by the rainfall information that there is rainfall or there has been rainfall within a predetermined time until now, the travel difficulty level is determined based on the rainfall information, the slope information, and the geological information. The navigation device according to claim 4. The travel difficulty level determination unit
Determining the travel difficulty for a plurality of predetermined routes;
The route setting unit
6. The route according to claim 4, wherein the travel difficulty level determined by the travel difficulty level determination unit is set to a route that matches a travel difficulty level desired by a user among the plurality of routes. Navigation device. The travel difficulty level determination unit performs the determination of the travel difficulty level using a determination condition in which the travel difficulty level increases as the slope of the road surface specified by the slope information increases. Item 7. The navigation device according to any one of Items 1 to 6. The travel difficulty level determination unit performs the determination of the travel difficulty level using a determination condition that the higher the travel difficulty level is, the worse the drainage of the road surface specified by the geological information is. Item 8. The navigation device according to any one of Items 1 to 7. The travel difficulty level determination unit performs the travel difficulty level determination using a determination condition in which the travel difficulty level increases as the amount of precipitation specified by the rainfall information increases. The navigation device according to any one of 1 to 8. A travel difficulty level determining step for determining a road travel difficulty level based on rainfall information and at least one of slope information and geological information;
A route setting method, wherein the route setting unit of the navigation device includes a route setting step of searching for a route to a destination based on the travel difficulty level determined by the travel difficulty level determination unit.