JP4220626B2 - Vehicle navigation device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle navigation apparatus that can automatically make a determination when the current position of a vehicle deviates from a recommended route.
[0002]
[Prior art]
When a vehicle deviates from a recommended route to a destination while traveling, a navigation device is known that can calculate a return route that returns from the deviated position to the first recommended route (Japanese Patent Laid-Open No. 63-163210). JP-A-7-272194 and JP-A-8-278156).
[0003]
In the navigation device described in each of the above publications, as a reference whether or not the vehicle has deviated from the route, it is determined whether or not the distance between the recommended route and the current position of the vehicle exceeds a certain threshold value.
[0004]
[Problems to be solved by the invention]
By the way, if the threshold value used as the reference | standard whether it deviated from the path | route is set to a fixed value, there exist the following difficulties.
[0005]
When traveling on a road with a short intersection distance such as a narrow street, the distance between the intersections may be smaller than a threshold value. For this reason, even if it deviates from the recommended route, the departure determination may not be in time, and the vehicle may pass through the intersection that should be bent along the return route. Also, when traveling on a road with a long intersection interval such as a mountain road, the distance between the intersections is sufficiently long, so that the departure determination may be performed slowly, but the departure determination is made with a short threshold. For this reason, it may be erroneously determined that the vehicle has deviated with a slight position detection error even though it has not deviated from the route.
[0006]
In addition, if a vehicle enters a service area or a parking area for a break or enters a gas station for refueling, it is determined as a departure. For this reason, it does not deviate, but it displays and guides that it deviates, and a driver is lost. In addition, when there are a plurality of areas or facility exits, a return route that makes a detour may be calculated.
[0007]
When a vehicle is guided using GPS (Global Positioning System), even if a temporary error correction occurs due to a GPS error, it is determined that the vehicle has deviated from the recommended route. Will be lost.
[0008]
Therefore, the present invention provides a vehicle navigation device that can accurately perform departure determination when traveling off the recommended route, thereby reducing the departure error determination rate and not causing unnecessary anxiety to the driver. It aims to be realized.
[0009]
[Means for Solving the Problems]
According to the vehicle navigation device of the first aspect of the present invention, the departure determining means for determining whether or not the vehicle deviates from the recommended route determines the road type of the road on which the vehicle is traveling, and determines the road type. According to the result, the deviation determination distance, which is a threshold value for determining whether or not the vehicle deviates from the recommended route, is changed.
[0010]
The “road type” may be determined for each road section according to the long or short distance between intersections, or a conventional administrative road type may be used. Specific examples of administrative road types include high-speed automobile national roads, automobile-only roads, national roads, prefectural roads, government-designated city roads, municipal roads, and narrow streets such as residential roads. Also, it may be divided into urban roads, rural roads, mountain roads, and the like.
[0011]
In addition, “change the deviation determination distance, which is a threshold value for determining whether the vehicle deviates from the recommended route according to the determination result of the road type”, specifically, the distance between the intersections is short. It is to shorten the deviation determination distance as the road type road is recognized, and to increase the deviation determination distance as the road type road is recognized as having a long distance between intersections.
[0012]
With the vehicle navigation device of this configuration, when driving on a short road between intersections such as urban roads and narrow streets, and distance between intersections such as highways and mountain roads Since the departure determination distance is changed depending on whether the vehicle is traveling on a long road, departure determination can always be performed using an appropriate threshold value. Therefore, the departure determination is not too late, and erroneous determination is not caused by a temporary decrease in position detection accuracy.
[0015]
According to the vehicle navigation device of the second aspect of the present invention, the departure determination unit evaluates the position detection accuracy of the position detection unit, and the vehicle deviates from the recommended route when the position detection accuracy is lowered. It is a thing which does not judge whether it is. An example of the position detecting means is GPS.
[0016]
If the position detection accuracy is low, it is easy to make a deviation error determination. In such a case, if it is erroneously determined that the vehicle has deviated, the driver will be confused. Therefore, it is not determined whether the vehicle has deviated from the recommended route.
[0017]
When the departure determination means determines that the vehicle deviates from the recommended route, the vehicle guidance means may give a constant display or voice guidance to the driver (claim 4 ). The means may calculate a return route to either the destination or the recommended route (Claim 5 ).
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0019]
FIG. 1 is a block diagram showing a configuration of a vehicle navigation device. This vehicle navigation apparatus includes a GPS receiver 1 for position detection, a vehicle speed sensor 2 for detecting a travel distance, and a direction sensor 3 such as a gyro, and these detection signals are used to detect the position of the vehicle navigation apparatus. Given to part 4.
[0020]
The position detection unit 4 determines the vehicle position based on the comparison between the travel distance information and the direction information by the vehicle speed sensor 2 and the direction sensor 3, the position information by the GPS receiver 1, and the road pattern stored in the map dedicated disk D. Is calculated. This calculation is performed every fixed period (for example, 1 second), and the position data of the vehicle is updated every period as the vehicle travels.
[0021]
The vehicle current position data detected by the position detection unit 4 is given to the map drawing unit 8 of the vehicle navigation device, where the road map, the vehicle current position mark on the map, and the recommended route (described later). ) Are generated and displayed on the monitor 10.
[0022]
The current position data of the vehicle detected by the position detection unit 4 is given to the route calculation unit 6. Based on the current position data, the destination data input from the operation keys 12 while looking at the map display, and the road map data given from the map dedicated disk D through the disk drive 5, the route calculation unit 6 The recommended route from the position to the destination (referred to as “initial route”) is calculated, and when it is determined that the vehicle has deviated from the initial route, the initial route is determined from the current position of the vehicle based on the current position data and the road map data. The recommended route (referred to as “return route”) to any of the points is calculated.
[0023]
The guidance control unit 9 interfaces with the speaker 11, the operation key 12, the monitor 10, etc., and guides the vehicle by issuing an instruction such as turning right or left at the intersection along the recommended route, and is detected by the position detection unit 4. It is determined whether or not the vehicle deviates from the initial route based on the current position data of the vehicle, and when it is determined that the vehicle deviates from the initial route, voice guidance is provided by the speaker 11 or the monitor 10 is A caution display is made or a return route calculation instruction is issued to the route calculation unit 6.
[0024]
The memory 14 attached to the guidance control unit 9 stores a distance integration table (described later), a link sequence that constitutes an initial route, a link sequence that constitutes a return route obtained as a result of return route calculation, and the like. .
[0025]
The road map data stored in the map dedicated disk D is a road map (high-speed automobile national roads, automobile exclusive roads, national roads, prefectural roads, ordinance-designated city roads, municipal roads, streets such as streets, facilities, etc. (Including roads in the area) is divided into meshes, and route data composed of combinations of nodes and links is stored for each mesh unit. In addition, various facilities and area data such as buildings, houses, gas stations, restaurants and parking lots, and various terrain data such as rivers, seas and lakes are also included.
[0026]
The mesh is divided into a Japanese road map with a longitude difference of 1 degree and a latitude difference of 40 minutes. The upper and lower meshes have a vertical and horizontal distance of about 80 km x about 80 km. It has a triple structure consisting of a medium mesh with a length of 10 km and a lower mesh with a size of about 1 km x about 1 km by dividing the medium mesh into 10 equal parts.
[0027]
A node is a coordinate point for specifying an intersection or a turning point on a road. A node representing an intersection is called an intersection node, and a node representing a bending point (excluding an intersection) is called an interpolation point node.
[0028]
A link connects a start point node and an end point node, and is a broken line with a direction along the shape of a road.
[0029]
By ignoring the shape of this broken line, the link cost information when passing through one or a plurality of linked links and the link in which information indicating the connection state with other compressed links is stored as data is referred to as “compressed link”. " This compressed link is used for route calculation.
[0030]
A link specified by the coordinates of nodes constituting a link in consideration of the degree of bending of the road is called a “shape link”. This shape link is used in the context of the present invention when determining whether or not the vehicle deviates from the recommended route.
[0031]
A data file storing compressed links is referred to as a link compressed file, and a data file storing the coordinates of nodes constituting a shape link for each one is referred to as a link shape file.
[0032]
The link compression file stores the road type, link cost, link length, pointer to other links connected to the link, connection cost, pointer to the shape link corresponding to the link, and the like.
[0033]
The link shape file has the coordinates of the start point node, the end point node, and the interpolation point node for each shape link, the pointer to the compressed link corresponding to the link, the road type of the link, and traffic regulation data. The “road type” includes, for example, (1) highways such as national highway roads, automobile roads, (2) national roads, prefectural roads, general roads such as government-designated city roads, and (3) living roads. Such narrow streets, and (4) road types for distinguishing roads in facilities such as service areas, parking areas, and parks.
[0034]
The initial route setting procedure will be described below.
[0035]
When the driver inputs a destination using the operation key 12, the route calculation unit 6 reads link shape data near the destination and near the current location and stores them in its own storage area.
[0036]
While acquiring these link shape data, the driver can set calculation conditions for requesting route calculation, such as whether to use a highway or set a waypoint. .
[0037]
Next, if there is a route calculation request from the driver by the operation key 12, the shape link closest to the current position is specified, the corresponding compression link is set as the calculation start link, and the shape link closest to the destination is specified. The compression link corresponding to is a calculation end link. Then, a route tree starting from the calculation end link is obtained, and a route passing through the calculation start link is determined as an initial route.
[0038]
The initial route is obtained as described above and displayed on the monitor 10. When the vehicle travels along this route, a car mark is displayed in the map based on the position of the vehicle detected by the position detection unit 4 while traveling.
[0039]
Next, a procedure for calculating a return route from the departure position to the initial route when the vehicle deviates from the initial route will be described.
[0040]
FIG. 2 is a flowchart for explaining the procedure of return route calculation. From the start to the end of this flowchart, it corresponds to one vehicle position calculation cycle (for example, 1 second) of the route calculation unit 6.
[0041]
Guidance control unit 9 calculates a moving distance D _M to the position detected this time from the position previously detected (step S1). Next it is determined whether D _M is more than a certain distance (step S2). D _M is about 10 m when the vehicle is traveling normally, but when a GPS position detection error occurs, the detection position flies greatly, so step S2 determines whether or not this position has jumped. It is to do. If D _M is equal to or greater than a certain distance (YES in step S2), the GPS instability flag is turned on, and the distance accumulation table in the memory 14 is cleared in the sense of starting accumulation of a new distance (step S3).
[0042]
If _DM is less than a certain distance (NO in step S2), it is determined whether the GPS instability flag is on (step S4). If it is on, the current travel distance is added to the distance integration table (step S5). ). Then, it is determined whether or not the integrated distance is equal to or greater than a certain value (for example, 500 m) (step S6). When the integrated distance does not reach a certain value, the comparison with the road pattern is not sufficient, and it is considered that the accuracy of the detection position is not ensured, so the departure determination is not performed. If the integrated distance is greater than or equal to a certain value, the GPS instability flag is turned off (step S7).
[0043]
When the GPS instability flag is off, the process proceeds to step S8, and it is determined whether or not the road currently being driven is a link between the service area and the parking area (step S8).
[0044]
FIG. 3 is a map illustrating a service area link (SA link).
[0045]
If it is a link between the service area and the parking area, the process ends. This is because when the vehicle is in the service area or the parking area, the vehicle largely bypasses the travel route, so it is determined that the vehicle is not suitable for departure determination.
[0046]
Next, it is determined whether the current location is in a facility such as a gas station or a parking lot (step S9).
[0047]
FIG. 4 is a map showing a gas station GS as an example of a facility adjacent to a road.
[0048]
This determination is made based on whether or not the current position of the vehicle is within the contour lines (polygons) of various facilities included in the road map data (step S10; contour of facilities in the map data). It is known to include line data, for example, see Japanese Patent No. 2849577). If the current position of the vehicle is within the facility outline, the process ends. This is because when the vehicle is in the facility, the travel route of the vehicle detours, so it is determined that the vehicle is not suitable for departure determination.
[0049]
Next, it is determined whether the traveling road type is a narrow street, a highway or a general road (steps S10 and S11), and the deviation determination distance _DD is used for a narrow street (for example, 25 m) according to the road type. It is set to a value for road (for example, 150 m) and for general road (for example, 50 m) (steps S12 to S14). This is because the deviation judgment distance is changed between when driving on a road with a short distance between intersections such as narrow streets and when driving on a road with a long distance between intersections such as highways. This is because the departure determination is always performed using an appropriate threshold value.
[0050]
Then, it is determined whether the distance from the current position to the initial route deviation determination distance D _D above (step S15). For example, as shown in FIG. 5, the distance from the current location to the initial route is determined by vertical lines D1, D2, D3,... To a plurality of shape links L1, L2, L3,. Of these, the distance of the shortest vertical line D2 may be used.
[0051]
Instead of measuring the distance of the vertical lines D1, D2, D3,..., The distance from the current position to the start point of the shape links L1, L2, L3,.
[0052]
Deviation determination distance is less than D _D, clears the deviation counter (step S16). If deviation judgment distance D _D above with up deviation counter (step S17), determines whether the deviation counter is more than a predetermined value (step S18), and if the predetermined value or more, automatically calculate return path (Step S19). The reason why the deviation counter is equal to or greater than a certain value is to reliably determine that the departure from the initial route has occurred.
[0053]
Here, when the return route is automatically calculated, it is arbitrary which link is selected as the calculation end link. For example, the destination link when the initial route is calculated (Japanese Patent Laid-Open No. 2-141899) may be used, and if a waypoint link is set, it may be a waypoint link scheduled to pass through (Japanese Patent Laid-Open No. 6-66587). Issue gazette). Further, it may be the link closest to the destination in the map in the range read from the map-dedicated disk D and stored in the DRAM (Japanese Patent Laid-Open No. 8-278156).
[0054]
When the return route is obtained, it is displayed on the monitor 10 together with the road map, and a new vehicle guidance is performed.
[0055]
Although the embodiments of the present invention have been described above, the embodiments of the present invention are not limited to the above-described embodiments. In the above-described embodiment, the return route is automatically calculated at the time of departure determination. However, the departure route may be notified only by display on the monitor 10 or sound by the speaker 11 without performing automatic calculation. The return route may be calculated only when the driver operates the operation key 12.
[0056]
In the above embodiment, it is determined whether or not the link running in step S8 is a link in the service area or the parking area in order to determine whether or not the vehicle is in the service area or the parking area. Judgment can be made based on whether the current position is inside or outside the polygon coordinates that represent the outline of the service area and parking area, and whether the distance from the center coordinates of the service area and parking area to the current position of the vehicle is within a certain distance May be.
[0057]
In the above embodiment, whether or not the current position of the vehicle is in a polygon representing the outline of various facilities is determined in step S9 to determine whether the vehicle is in a facility such as a gas station or a parking lot. However, if the links of various facilities are defined, it may be determined whether or not the traveling link is the link of the facility. You may determine by the distance to a position being within a fixed distance.
[0058]
Further, in the above embodiment, the deviation determination distance _DD is changed depending on whether the type of road being traveled is a narrow street, a highway, or a general road. It is not limited to. The roads may be divided into national roads, prefectural roads, municipal roads, etc., and may be divided into urban roads, suburban roads, mountain roads, and the like. Further, in each section the section of the road, the operator may go to set the deviation determination distance D _D.
[0059]
In addition, various modifications can be made within the scope of the present invention.
[0060]
【The invention's effect】
As described above, according to the first aspect of the present invention, when driving on a road with a short distance between intersections such as urban roads and narrow streets, and like highways and mountain roads, Since the departure determination distance is changed depending on whether the vehicle is traveling on a road with a long distance between intersections, the departure determination can always be performed using an appropriate threshold value. Therefore, the departure determination is not too late or too fast, and an appropriate instruction can always be given to the driver.
[0062]
According to the second aspect of the present invention, if the position detection accuracy is lowered, it is not erroneously determined to be a deviation as in the conventional case, so that the driver can be given a sense of reliability.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a vehicle navigation apparatus.
FIG. 2 is a flowchart for explaining a procedure of return path calculation.
FIG. 3 is a map showing a service area near the highway.
FIG. 4 is a map showing a gas station GS as an example of a facility adjacent to a road.
FIG. 5 is a diagram for explaining how to measure the distance from the current location to a recommended route;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 GPS receiver 2 Vehicle speed sensor 3 Direction sensor 4 Position detection part 5 Disk drive 6 Path | route calculation part 8 Map drawing part 9 Control part 10 Monitor 11 Speaker 12 Operation key 14 Memory

Claims (5)

Position detection means for detecting the current position of the vehicle, display means for reading map information from the storage medium and displaying the map together with the current position of the vehicle, setting means for setting the destination, and a recommended route to the set destination A route calculating means for automatically calculating, a vehicle guiding means for guiding the vehicle to the destination along the calculated recommended route, and a deviation determining means for determining whether the vehicle deviates from the recommended route,
The deviation determining means, the road running along the recommended route, to determine the road type or the road type of administrative defined in accordance with the long short distances between intersections, the judgment result of the road type Accordingly, the vehicle navigation apparatus is characterized in that the deviation determination distance from the current location of the vehicle to the recommended route is changed as a threshold value for determining whether or not the vehicle deviates from the recommended route . Claim before Symbol deviation determining means evaluates the position detection accuracy of the position detection means, when the position detection accuracy is lowered, characterized in that no determination of whether the vehicle is deviating from the recommended route The vehicle navigation device according to claim 1. The vehicle navigation apparatus according to claim 2 , wherein the position detection means is position detection means using GPS (Global Positioning System). 4. The vehicle guidance device according to any one of claims 1 to 3 , wherein when the departure determination unit determines that the vehicle deviates from the recommended route, the vehicle guidance unit provides a constant display or voice guidance to the driver. The vehicle navigation device described in 1. When the departure determining means determines that the vehicle deviates from the recommended route, the route calculating means calculates a return route to reach either the destination or the recommended route. The vehicle navigation device according to any one of claims 1 to 4 .

Images