JP2009025178A - Navigation apparatus and program for navigation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve precision in specification processing of a driving road based on the grade information of the road. <P>SOLUTION: A navigation apparatus stores road information indicating grade information for each road and the setting information of a determent section in advance. The determent section is a section for preventing the actual grade of a driving road that becomes a criterion of the road from being detected, and for example, is set in a section less than a radius L1 from a junction. The CPU of the navigation apparatus determines whether a vehicle is running on the determent section based on drive distance from the junction, when detecting the passage of the junction by an access road. When the road runs off the determent section, the CPU detects the actual grade of the driving road and checks the grade information of specific target candidate roads (access roads and general roads) up with the detected, actual grade. Then, the CPU specifies a road having a smaller degree of correlation with the actual grade of the driving road from the candidate roads, and displays the position of an own vehicle on the corresponding road on a map, based on the specified result. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a navigation device and a navigation program, and, for example, relates to a technique for displaying a vehicle position on a map.

Navigation devices that search for a travel route to a destination and perform route guidance are widely used.
The navigation device has a function of performing map matching processing based on vehicle position information calculated using GPS (Global Positioning System) or the like and map data, and displaying the vehicle position on a road on the map. Is provided.
In such a navigation device, a technique for improving the matching accuracy between the actual current position of the vehicle and the vehicle position displayed on the map is proposed in the following patent document.
Japanese Patent Laid-Open No. 10-253373

In the technique described in Patent Document 1, the gradient of a road that is running is detected by a sensor provided in the vehicle, and based on the collation result between the detected road gradient and road gradient information stored in a map database. The vehicle position displayed on the map is corrected.
Fig.8 (a) is the figure which showed the example of arrangement | positioning of the attachment road.
For example, the determination as to whether or not the vehicle has entered a road (hereinafter referred to as an attachment road C) that connects roads with different elevations such as a general road A and a highway B as shown in FIG. Based on such road gradient information, the road on the map is identified based on the determination result.

By the way, if the gradient information for the attachment road C stored in the map database is stored as information for each subdivided section, it takes time to collect data and increases the amount of data. Therefore, some map databases store the same gradient information from a branch point to a merge point as rough gradient information in order to reduce the amount of data to be stored. For example, in the case of the attachment road C connecting the general road A and the highway B, “up” is set as gradient information from the branch point of the general road A to the junction of the highway B. The gradient information is defined in three stages of “upper / flat / lower”.
FIG. 8B is a diagram showing an example of the actual slope of the attachment road.
However, as shown in FIG. 8B, the actual attachment road C has a flat portion without a gradient immediately after the branch point (section a).
For this reason, even if the vehicle has entered the attachment road C with the gradient information “up”, the sensor of the vehicle traveling in the section a determines that the gradient of the section is “flat”.

In this way, when the gradient information “upper” of the attachment road C stored in the map database and the actual sensor detection result “flat” do not match, the navigation device selects the road corresponding to the sensor detection result “flat”. (In this case, the general road A) is identified as a traveling road, and the vehicle position is displayed on the road.
In other words, in the section “a” where the gradient does not actually appear, an incorrect own vehicle position is specified, which may reduce the matching accuracy between the own vehicle position displayed on the map and the actual current position of the vehicle. It was.

FIG.8 (c) is the figure which showed the other example of arrangement | positioning of the attachment road.
For example, even when actually entering the attachment road C from the expressway B shown in FIG. 8C, the same erroneous determination is made in the section where the slope does not actually appear on the attachment road C, In some cases, the vehicle position was specified.

In addition, when the vehicle position is erroneously identified as described above while traveling along the guidance route to the destination, the navigation device determines that the vehicle has deviated from the guidance route.
When the reroute function for resetting the guide route to the destination when the host vehicle deviates from the guide route is effective, the navigation apparatus resets the guide route from the wrong vehicle position to the destination. That is, the influence of the vehicle position specified by mistake extends to the guide route.

  Therefore, an object of the present invention is to further improve the accuracy of a road identification process based on road gradient information.

(1) In order to achieve the above object, according to the first aspect of the present invention, there is provided map data storage means for storing map data having road information in which roads are associated with gradient information of the roads; Branch passage detection means for detecting passage of a branch point with a gradient road in which the gradient information is stored, and, after detecting the passage of the branch point, traveling outside a predetermined deterrence zone determined based on the branch point The actual gradient detecting means for detecting the actual gradient of the traveling road, the road identifying means for identifying the road on the map on the basis of the detected actual gradient of the traveling road and the road information, and the identified And a vehicle position display means for displaying the current position of the vehicle on a road.
(2) The invention according to claim 2, further comprising distance measuring means for measuring a distance from the branch point, wherein the actual gradient detecting means is the predetermined inhibition set based on the distance from the branch point. The navigation device according to claim 1, wherein an actual slope of the traveling road is detected while traveling outside the area.
(3) In the invention according to claim 3, the predetermined deterrent area includes a section of a predetermined distance from at least one of the junction point and the junction with the other road on the gradient road. A navigation device according to claim 1 or 2 is provided.
(4) In the invention described in claim 4, the predetermined deterrence zone is set based on the gradient road for each branch point with the gradient road. A navigation device according to any one of claims 3 is provided.
(5) In the invention according to claim 5, the gradient road is an attachment road that connects roads having a difference in height, according to any one of claims 1 to 4. A navigation device is provided.
(6) The invention according to claim 6, further comprising altitude detecting means for detecting a traveling altitude based on the branch point, wherein the road specifying means further includes a map during traveling based on the detected traveling altitude. The navigation apparatus according to any one of claims 1 to 5, wherein an upper road is specified.
(7) In the invention described in claim 7, the computer detects a branch passage detection means for detecting passage of a branch point with a slope road in which gradient information is stored in the map data, and detects passage of the branch point. Thereafter, an actual gradient detecting means for detecting an actual gradient of the traveling road while traveling outside the predetermined deterrence area determined based on the branch point, a road stored in the map data storage means, and gradient information of the road, Based on the road information associated with the detected road and the actual gradient of the detected road, road specifying means for specifying the road on the map that is running, and the current position of the vehicle on the specified road are displayed. There is provided a navigation program characterized by functioning as a vehicle position display means.

  According to the present invention, by detecting the actual gradient of the traveling road outside the predetermined deterrent area, it is possible to perform a more accurate road identification process based on the detected actual gradient.

Hereinafter, a preferred embodiment of the navigation device of the present invention will be described in detail with reference to FIGS. 1 to 7.
(1) Outline of Embodiment The navigation device has a map matching function for identifying a road on which a vehicle exists based on vehicle position information, operation information, environmental information, and the like and map data.
In the present embodiment, a method for identifying a road on which a vehicle exists based on the actual slope of a road that is running and the slope information that the road information has will be described.
Here, a case will be described in which it is determined whether the vehicle has entered the attached road or is continuously running on the general road when passing through the branch point with the attached road while traveling on the general road.
The navigation device stores in advance road information indicating gradient information for each road and setting information for a suppression section.
The suppression section is a section in which the actual gradient of the traveling road that is the road determination criterion is not detected, and is set, for example, in an area less than the radius L1 from the branch point.

When the CPU of the navigation device detects the passage of the branch point with the attachment road, it determines whether or not the vehicle is traveling in the inhibition zone based on the travel distance from the branch point.
When the vehicle goes out of the suppression section, the CPU detects the actual gradient of the road that is running, and collates the gradient information of the candidate road (attached road, general road) to be identified with the detected actual gradient. Then, a road having a smaller degree of correlation with the actual gradient of the traveling road is identified from the candidate roads, and the vehicle position is displayed on the corresponding road on the map based on this identification result.
In the present embodiment, a section where an actual slope that does not match the slope information of the road information may be detected is set as a suppression section, and map matching processing based on the actual slope of the traveling road is performed while the vehicle is traveling in the suppression section. Not performed.

(2) Details of Embodiment FIG. 1 is a diagram showing a configuration of a navigation device according to this embodiment.
As shown in FIG. 1, the navigation apparatus includes a CPU (Central Processing Unit) 10 that controls the entire navigation apparatus according to various programs and data. The CPU 10 includes a current position detection unit 11, a gradient sensor 12, and a map DB. A (database) 13, a display device 14, an input device 15, a RAM 16, and a ROM 17 are connected.

The CPU 10 includes a register which is a small amount and a high-speed storage device in the inside thereof, and for example, information on an upper / lower road determination flag and a suppression section flag indicating a determination result of a condition in the map matching process is stored in this register.
The current position detection unit 11 includes a vehicle speed sensor 111, a gyro sensor 112, and a GPS receiver 113 for detecting the current position of the vehicle on which the navigation device is mounted.
The vehicle speed sensor 111 is a device that detects the vehicle speed based on the rotational speed of the wheels, for example. In the navigation device, the moving distance of the vehicle is measured based on the detection result of the vehicle speed sensor 111. That is, the vehicle speed sensor 111 functions as a distance measuring unit that measures the moving distance of the vehicle. In the present embodiment, the vehicle speed sensor 111 is also used when measuring the moving distance from the branch point.

The gyro sensor 112 is a device that detects a change in the traveling direction of the vehicle, and functions as an azimuth detecting unit that detects an angle that has changed relative to a reference angle (absolute azimuth).
The GPS receiver 113 is a device that receives information from a GPS (Global Positioning System) that measures a position using an artificial satellite.
The navigation device is configured to detect the vehicle position by using both the self-contained navigation using the vehicle speed sensor 111 and the gyro sensor 112 and the satellite navigation using the GPS receiver 113, but the self-contained navigation or the satellite navigation is used. The vehicle position may be detected using any one of the above.

The gradient sensor 12 is a sensor that detects the gradient (inclination angle) of the road. In the navigation device, the road inclination angle detected by the inclination sensor 12 is compared with a predetermined threshold value to determine the inclination state of the running road.
Specifically, when the detected inclination angle θ is less than the threshold value α, it is determined that the gradient is “downward” (“down”), and when the inclination angle θ is greater than or equal to the threshold value α and less than the threshold value β, it is determined as flat (“flat”). If the inclination angle θ is equal to or greater than the threshold value β, it is determined that the slope is “upward” (“up”). It should be noted that the threshold values α and β serving as the determination criteria for the gradient state can be set to arbitrary values.

The map DB 13 is a storage device that stores map data necessary for map display, node information used for route search to a destination, map matching processing, and the like, road information, suppression section information, and the like.
Here, information stored in the map DB 13 will be described.
FIG. 2A is a diagram for explaining node information and road information.
The node information is information related to a node indicating an intersection, a branch point, a merge point, an interpolation point for indicating a road shape, and the like indicated by black dots in FIG. In the node information, for example, node position information and map data correspondence information are shown for each node identification code (node No.).

The road information is information relating to a link in which a road section connecting two nodes indicated by an arrow in FIG.
FIG. 2B is a diagram showing an example of road information.
As shown in FIG. 2B, the road information includes, for example, a start node No, an end node No, a road type (highway, national road, prefectural road, municipal road, attachment road, etc.), gradient information (upper, Flat, lower) and the like are shown for each link identification code (link No.).
In addition, the attachment road shown by road classification shows the road which connects between roads with a height difference like a general road (national road, prefectural road, etc.) and a highway. In addition, this attachment road is a gradient road having gradient information.
In the present embodiment, two link vectors having different directions are separately set as link information between nodes, but the link information setting method is not limited to this. For example, a link between nodes may be represented by a single link vector, and the link vector with attributes of the forward direction and the reverse direction may be stored as road information.

Next, the suppression section information will be described.
FIG. 3 is a diagram for explaining the suppression section.
In the navigation device, in order to determine whether or not the vehicle has entered the attachment road when passing through a branch point with the attachment road, an upper / lower road determination process for specifying a traveling road based on the actual gradient is performed.
In this up-and-down road determination process, the actual gradient of the traveling road detected by the gradient sensor 12 is checked against the gradient information of the road (link) of the traveling candidate, and the candidate road or the actual gradient whose gradient information matches the actual gradient The candidate road with the smallest correlation value is identified as the road that is running.
However, on an actual attachment road, there may be a section where no gradient appears in the vicinity of the branch point as shown in FIG. Therefore, it is necessary to travel a certain distance until an actual gradient that matches the gradient information actually recorded in the road information is detected.

Therefore, in this embodiment, in order to increase the accuracy of the upper / lower road determination process, a suppression section (a suppression section) in which an actual gradient is not detected is set.
In the present embodiment, as shown in FIG. 3, a section having a radius less than L1 from the branch point with the attachment road is set as the suppression section.
The value of L1 that is a determination criterion for the suppression section can be arbitrarily set, and this set value is common at all branch points with the attached roads.
The map DB 13 stores the above-described setting information of the suppression section as the suppression section information.

The display device 14 displays processing results of the CPU 10 such as a map screen around the current location (for example, a screen in which the vehicle position is marked), vehicle position information, route guidance information, a destination setting screen, various menu screens, and the like. Output device.
The input device 15 is a device for inputting data such as a destination, a passage point, and a search condition by a user.
In this embodiment, the display device 14 and the input device 15 are configured by a touch panel (touch screen) having both display and input functions. However, the input device 15 is configured by a remote controller such as a jog dial. May be.
Although not shown, a speaker for outputting route guidance by voice or a printer for printing out processing data may be provided separately as an output device.

The RAM 16 is a storage area that functions as a work area for the CPU 10.
The ROM 17 is a read-only memory in which basic programs and parameters for causing the navigation device to function are stored. The ROM 17 stores, for example, a map matching program 171 that specifies a road that is currently running and a position on the road, a route search program that searches for a route to a destination, and the like.
Note that the matching program 171 may load a program stored in a storage medium such as a CD-ROM, DVD-ROM, hard disk, or flash memory into the RAM 16 to be executed.

Next, an upper / lower road determination process executed when the passage of a branch point with an attachment road is detected in the navigation device configured as described above will be described.
In this embodiment, when the passage of a branch point with an attachment road is detected, matching between the actual vehicle travel position (travel road) and the vehicle position displayed on the road on the map is performed by an up-and-down road determination process. Do. A program for executing the upper / lower road determination process is included in a part of the map matching program 171.
Here, a case where a vehicle traveling on the general road A passes through a branch point between the general road A and the attachment road C connecting the highway B will be described as an example.
It should be noted that the branch point between the general road A and the attachment road C is the node number shown in FIG. Corresponding to aa0002, the junction of the attachment road C and the highway B is the node No. Corresponding to bb0002, the attachment road C entering from the branch point is a link number. Corresponds to C0001.

FIG. 4 is a flowchart showing the procedure of the upper / lower road determination process.
FIG. 5 is a diagram for explaining the up / down road determination process.
The CPU 10 reads the built-in register and determines whether or not the passage of the branch point with the attachment road has been detected based on the state of the up / down road determination flag (step 11). Specifically, the CPU 10 determines that the passage of the branch point has been detected when the up / down road determination flag is in the ON state (standing state), and the up / down road determination flag is in the OFF state (not standing). It is determined that the passage of the branch point has not been detected.
When the passage of the branch point is not detected (step 11; N), the CPU 10 determines whether or not the vehicle has passed the branch point with the attachment road (step 12).
Here, based on the position information of the vehicle detected by the current position detection unit 11 and the road information stored in the map DB 13, whether the vehicle has passed the node that is the starting point of the link corresponding to the attachment road Judge whether or not.

For example, when the vehicle is traveling on P1 before the branch point shown in FIG. 5A, passage of the branch point with the attachment road is not detected.
In the present embodiment, during traveling in a section where there is no branch point with the attachment road, the normal road gradient is not considered, and is performed based on the vehicle position information and map data detected by the current position detection unit 11. Based on the result of the map matching process, the vehicle position is displayed on the road on the map.
Therefore, when the vehicle is traveling in the position of P1, based on the position information of P1 detected by the current position detection unit 11, the position P1 ′ of the general road A on the map shown in FIG. The own vehicle position (own vehicle position mark) is displayed.

When the passage of the branch point with the attachment road is not detected (step 12; N), the CPU 10 maintains the OFF state of the upper / lower road determination flag of the register (step 13).
When the passage of the branch point with the attachment road is detected (step 12; Y), the CPU 10 switches the upper / lower road determination flag of the register to the ON state and further switches the suppression section flag to the ON state (step 14).
The inhibition zone flag is a flag indicating that the vehicle is traveling in the inhibition zone. Since the suppression section starts from a branch point, the suppression section flag is set to be turned on when the passage of the branch point is detected.

If it is determined in step 11 that the passage of the branch point with the attachment road has been detected (step 11; Y), the CPU 10 determines whether or not the vehicle is traveling in the suppression section (step 15). .
Here, the moving distance from the branch point is measured based on the detection result of the vehicle speed sensor 111, and it is determined based on the measurement result whether the vehicle is traveling in the inhibition zone.
When the vehicle is traveling in the inhibition zone (step 15; Y), the CPU 10 maintains the ON state of the inhibition zone flag in the register (step 16). Here, the ON / OFF state of the up / down road determination flag of the register is also maintained.
When the vehicle is not traveling in the inhibition zone (step 15; N), that is, when the vehicle is outside the inhibition zone, the CPU 10 switches the inhibition zone flag to the OFF state (step 17). Here, the ON / OFF state of the up / down road determination flag of the register is maintained.

For example, when the vehicle is traveling in P2 or P3 shown in FIG. 5A, it is determined that the vehicle is traveling in the inhibition zone.
In the present embodiment, while the vehicle is traveling in the suppression section, the vehicle position is displayed on the road (in this case, the general road A) that was traveling before passing through the branch point.
Accordingly, when the vehicle is traveling at the position P2 or P3, the host vehicle position is temporarily displayed on P3 ′ of the general road A on the map shown in FIG. 5B.
However, the navigation apparatus recognizes positions on the map corresponding to both P2 and P3 as matching candidates for the vehicle position.

Subsequently, the CPU 10 reads out a built-in register, and determines whether or not map matching processing by vertical path determination is necessary based on the state of the vertical path determination flag (step 18). The CPU 10 determines that the map matching process based on the vertical path determination is necessary when the vertical path determination flag is ON, and determines that the map matching process based on the vertical path determination is unnecessary when the vertical path determination flag is OFF. .
When the map matching process by the upper / lower road determination is necessary (step 18; Y), the CPU 10 determines whether or not the vehicle is traveling in the inhibition zone based on the state of the inhibition zone flag (step 19). When the inhibition zone flag is in the ON state, the CPU 10 determines that the vehicle is traveling in the inhibition zone, and when the inhibition zone flag is in the OFF state, the CPU 10 determines that the vehicle is traveling outside the inhibition zone.

When the vehicle is not traveling in the inhibition zone (step 19; N), the CPU 10 determines the actual slope state of the currently traveling road, and collates this determination result with the road information (step 20). Specifically, the CPU 10 determines the actual slope state of the currently traveling road based on the slope angle of the road detected by the slope sensor 12. Then, the actual gradient judgment result and the node No. The gradient information of the link branched from aa0002 is collated. Here, the actual slope determination result is displayed as a link number. A0003 (general road A) and link no. It collates with the gradient information of C0001 (attached road C).
CPU10 specifies the road on the map in progress based on the collation result with gradient information (step 21). Here, the link No. A0003 and Link No. Among C0001, the road corresponding to the link whose slope information matches the actual slope determination result ("up", "flat", or "down") is identified as the road on the running map.
Subsequently, the CPU 10 displays the vehicle position on the road on the map based on the road identification result and the travel distance from the branch point (step 22).

For example, when the vehicle is traveling on P4 (attachment road C) outside the inhibition section shown in FIG. 5A, the gradient “up” is determined based on the road inclination angle detected by the gradient sensor 12. The
Link No. The gradient information of A0003 (general road A) is “flat”, and the link No. The gradient information of C0001 (attachment road C) is “up”.
Therefore, the CPU 10 determines the link number. C0001 (attached road C) is identified as a road on the running map, and on the basis of this identification result, the vehicle position on the map is changed from P5 ′ (general road A) to P4 ′ (shown in FIG. 5B). Correct to attachment road C).
Further, for example, when the vehicle is traveling on P5 (general road A) outside the inhibition section shown in FIG. 5A, the gradient “flat” is determined based on the gradient sensor 12, and the link No. A0003 (general road A) is identified as the road on the traveling map. In this case, the display of the vehicle position on the general road A is continued.

The CPU 10 switches the state of the upper / lower road determination flag and the suppression section flag to OFF, that is, initializes the flag (step 23), and returns to the process of step 11.
Further, when it is determined that the map matching process based on the up / down road determination is unnecessary in the process of step 18 (step 18; N), and in the process of step 19, the vehicle is traveling in the suppression section. If it is determined (step 19; Y), the CPU 11 returns to the process of step 11.

Such a map matching process considering the road gradient is performed in parallel with the normal map matching process. Then, when the attachment road and other candidate roads are within the normal error range of the map matching process, that is, when the attachment road is close to other candidate roads, the map in consideration of the road gradient described above The vehicle position on the map based on the matching process is corrected.
For example, when it is difficult to determine an accurate driving road in normal map matching processing based on vehicle position information, such as when an expressway and an attachment road branching from the expressway are running side by side, the road described above Map matching processing considering the gradient is performed.

As described above, according to the present embodiment, by specifying the road on the map that is being traveled based on the actual slope and road information of the travel road that is detected while traveling outside the suppression section, it is possible to achieve higher accuracy. It is possible to perform a process for identifying the road that is running. Thereby, it can suppress that the own own vehicle position is displayed on a map.
Further, in this embodiment, when it is detected that the vehicle is out of the suppression section, the road specifying process for displaying the vehicle position based on the actual gradient is performed only once, and then the branch point with the attachment road is again displayed. The road identification process based on the actual gradient is not performed until the passage is detected.
Thereby, it can suppress that the own own vehicle position is specified while driving | running | working the flat area near the junction on an attachment road.

In the embodiment described above, the set distance (L1) of the suppression section is set so as to be common at the branch points with all the attachment roads.
However, since the length of the attachment road, the position where the gradient appears, and the like are different for each attachment road, the distance of the suppression section may be set for each branch point with the attachment road.
A plurality of setting patterns of the suppression section may be set, and the setting pattern may be assigned according to the length of the attachment road at each branch point with the attachment road. For example, the setting pattern A (100 m) is assigned when the attached road length is less than 500 m, and the setting pattern B (200 m) is assigned when the attached road length is 500 m or more and less than 1000 m.
You may make it set the setting distance of a suppression area by the ratio (ratio) with respect to the length of an attachment road. For example, you may make it set 20% of the length of an attachment road to the setting distance (L1) of a suppression area.
In addition, it is preferable to set the suppression area based on actual measurement data at the branch point with the attachment road where the actual measurement data of the distance from the branch point to the position where the gradient actually appears exists.

Further, in the above-described embodiment, while the vehicle is traveling in the suppression section, the vehicle position is displayed on the road that was traveling before passing the branch point. The display form during traveling is not limited to this.
For example, when the vehicle is traveling in the suppression section, the vehicle position is displayed on the starting point of the suppression section on the map, the branch point with the attachment road C, and the road identification result and the travel distance from the branch point in step 22 When the vehicle position is displayed on the road on the map based on the above, the vehicle position may be moved from the branch point.

(Modification)
In the present embodiment described above, at the time when it is detected that the vehicle is out of the suppression section, the road specifying process for displaying the vehicle position based on the actual gradient is performed only once. Once the road specifying process is performed, the road specifying process based on the actual gradient is not performed until the passage of the branch point with the attachment road is detected again.
However, the road identification method based on the actual slope outside the suppression section is not limited to this.
Therefore, in the modified example, a method for performing the road specifying process based on the actual slope not only once but continuously outside the suppression section during the traveling period will be described.

FIG. 6 is a diagram for explaining a suppression section in the modification.
In an actual attachment road, as shown in FIG. 6A, there is a section where a gradient does not appear not only near the branch point but also near the junction.
Therefore, in the modification, the suppression section in which the actual gradient is not detected is further set to an area including the vicinity of the merging point.
Specifically, as shown in FIG. 6, as the suppression section, a section having a radius less than L1 from the branch point with the attachment road and a section having a radius L2 to the attachment road length from the branch point are set.
In other words, the section from radius L1 to less than L2 from the branch point is set as the actual slope detection section that is the determination criterion for the up / down road determination processing.
The values of L1 and L2 that serve as determination criteria for the suppression section can be arbitrarily set, and all of the set values are common at the branch point with the attachment road. However, as in the above-described embodiment, the attachment road You may make it set the distance of a suppression area for every branch point.

In the modification, the CPU 10 measures the movement distance from the branch point based on the detection result of the vehicle speed sensor 111, and based on the measurement result, the section where the vehicle is at a radius L1 or more and less than L2 from the branch point (outside the suppression section). Detects the period of traveling.
The CPU 10 continuously performs a series of processes in steps 20 to 22 in FIG. 4 during a period of traveling outside the detected suppression section.
Specifically, during the period of traveling outside the suppression section, the actual slope determination process of the road that is running, the verification process of the determination result and the road information, the road identification process on the map based on the verification result, Display processing (correction processing) of the vehicle position on the map based on the specific result, and a series of these processing are performed a plurality of times.
When traveling in the second half of the suppression section, the map is not based on the normal map matching process based on the vehicle location information, but based on the road identification process result on the map during the period of traveling outside the suppression section. The vehicle position is displayed on the upper road.

Here, every time a road on the map being traveled is identified, the display processing (correction processing) of the vehicle position on the map based on this identification result is performed. The timing for performing the correction processing is not limited to this.
For example, a map that is determined to be the most probable based on the tabulation results when counting the specific results of roads that are running during the period outside the deterrent section and entering the latter half of the deterrent section The vehicle position may be displayed (corrected) on the upper road.
According to the modified example, by providing the second half of the suppression section, it is possible to appropriately set the detection section of the actual slope that is the reference for the road specifying process.

In the embodiment and the modification described above, the road on the map that is being traveled is identified based on the collation result between the actual slope of the travel road detected by the gradient sensor 12 while traveling outside the suppression section and the road information. It is configured. In order to increase the accuracy of identifying the road on the traveling map, the altitude information of the traveling vehicle may be further taken into consideration.
Specifically, the altitude sensor (altimeter) is used to detect the altitude based on the branch point of the traveling vehicle, and the gradient state of the road being traveled is determined based on the detected altitude information of the vehicle and the detection result of the gradient sensor 12. judge. Then, the road on the map that is running may be specified based on the collation result between the determination result of the gradient state and the road information.
The altitude based on the branch point of the traveling vehicle may be calculated based on the inclination angle θ detected by the gradient sensor 12 and the travel distance after the passage of the branch point with the attachment road is detected. Good.

In the present embodiment described above, the method of identifying the road where the vehicle exists based on the actual slope of the road that is running and the slope information of the road information is used, when the vehicle passes a branch point with the attachment road. Was described as an example. However, the location where the method for specifying the vehicle position in consideration of the suppression section as described above can be applied is not limited to the branch point with the attachment road.
FIG. 7 is a diagram showing another application location of the method for specifying the vehicle position according to the present embodiment.
For example, as shown in FIG. 7, even when passing through a branch point with the general road B having gradient information, a method for specifying the own vehicle position in consideration of the suppression section may be applied.
In the above-described embodiment and modification, the case where the general road and the highway connected by the attachment road are parallel to each other has been described as an example, but the arrangement environment of the attachment road is not limited to this. For example, it is possible to apply a method for specifying the position of the vehicle in consideration of the suppression section even if it is an attachment road that connects a general road that intersects with an expressway.

It is the figure which showed the structure of the navigation apparatus in this embodiment. (A) is a figure for demonstrating node information and road information, (b) is a figure which showed an example of road information. It is a figure for demonstrating the suppression area. It is the flowchart which showed the procedure of the up-and-down road determination process. It is a figure for demonstrating an up-and-down road determination process. It is a figure for demonstrating the suppression area in a modification. It is the figure which showed the other application location of the identification method of the own vehicle position which concerns on this Embodiment. (A) is the figure which showed the example of arrangement | positioning of an attachment road, (b) is the figure which showed an example of the actual gradient of an attachment road, (c) is the figure which showed the other arrangement example of the attachment road. is there.

Explanation of symbols

10 CPU
11 Current Position Detection Unit 12 Gradient Sensor 13 Map DB
14 Display device 15 Input device 16 RAM
17 ROM
111 Vehicle speed sensor 112 Gyro sensor 113 GPS receiver 171 Map matching program

Claims (7)

Map data storage means for storing map data having road information associating a road with gradient information of the road;
Branch passage detection means for detecting passage of a branch point with a gradient road in which gradient information is stored in the map data;
An actual gradient detecting means for detecting an actual gradient of the traveling road while traveling outside a predetermined deterrence area determined based on the branch point after detecting the passage of the branch point;
Road identifying means for identifying a road on a map on the basis of the detected actual gradient of the traveling road and the road information;
Own vehicle position display means for displaying the current position of the own vehicle on the identified road;
A navigation device comprising:
A distance measuring means for measuring a distance from the branch point;
2. The navigation apparatus according to claim 1, wherein the actual gradient detecting means detects an actual gradient of the traveling road while traveling outside the predetermined deterrence zone set based on a distance from the branch point.
The navigation device according to claim 1 or 2, wherein the predetermined deterrent area includes a section of a predetermined distance from at least one of the branch point and the junction with another road on the gradient road. .
The navigation according to any one of claims 1 to 3, wherein the predetermined deterrent area is set for each branch point with the gradient road based on the gradient road. apparatus.
The navigation apparatus according to any one of claims 1 to 4, wherein the slope road is an attachment road that connects roads with different heights.
Altitude detecting means for detecting a traveling altitude based on the branch point is provided,
The navigation device according to any one of claims 1 to 5, wherein the road specifying unit further specifies a road on a map that is being driven based on the detected driving altitude. .
Computer
Branch passage detection means for detecting passage of a branch point with a gradient road in which gradient information is stored in the map data;
An actual gradient detecting means for detecting an actual gradient of the traveling road while traveling outside a predetermined deterrence area determined based on the branch point after detecting the passage of the branch point;
Road specifying means for specifying a road on a map on the basis of road information associated with the road and gradient information of the road stored in the map data storage means and the detected actual gradient of the road When,
Own vehicle position display means for displaying the current position of the own vehicle on the identified road;
A navigation program characterized in that it functions as a function.

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