JP3550809B2 - Vehicle navigation system - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vehicle navigation device that detects a current position of a vehicle and displays a name of a point near the current position.
[0002]
[Prior art]
Conventionally, as this type of device, there is a "simple navigation device" disclosed in Japanese Patent Application Laid-Open No. 3-92714. In this apparatus, the current position of a vehicle is detected using a GPS receiver, the nearest point is specified from a plurality of predetermined display target points, and the name of the point is displayed.
[0003]
[Problems to be solved by the invention]
However, in the above, since the name is displayed for the point closest to the current position, as long as the point at which the vehicle has passed is the closest point, the name display for the point is continued, and it is appropriate. There is a problem that the name is not displayed.
[0004]
SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to prevent name display at a point where a vehicle has passed, and to perform name display in a form in accordance with the traveling direction of the vehicle.
[0005]
Summary of the Invention
According to the first aspect of the present invention, a point in proximity to the current position is specified among points within a predetermined angle range with respect to the traveling direction of the vehicle, and the name of the specified nearby point is displayed. It is characterized by the following points.
Therefore, points that are not within a predetermined angle range from the traveling direction of the vehicle, such as points that the vehicle has passed, are excluded from the display target points, and the name display can be performed for a nearby point that is in line with the traveling direction of the vehicle. .
[0006]
Further, in the invention described in claim 1 , the distance between the point and the current position is changed to a value corresponding to the declination between the traveling direction of the vehicle and the direction of the point, and the proximity point is determined based on the changed distance. The feature is that it is specified. Therefore, since the distance between the point and the current position for specifying the proximity point is changed by the declination, it is easy to specify the point in the traveling direction of the vehicle as the proximity point, and thus the traveling direction is more improved. Can be displayed.
[0007]
The invention according to claim 2 is characterized in that an area in the traveling direction is specified, and a point close to a point in the area is specified. Therefore, by specifying the area, it is possible to simplify the processing required for specifying the proximity point.

[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention shown in the drawings will be described.
(1st Embodiment)
FIG. 1 shows the overall configuration of a vehicle navigation device.
In FIG. 1, a GPS receiver 1 includes a GPS antenna 1a, an amplifier 1b, and a GPS reception processing unit 1c, receives a radio wave from an artificial satellite, performs positioning processing, and obtains current position coordinate data of latitude and longitude indicating the current position of the vehicle. And so on.
[0009]
The key input unit 2 is operated by an occupant of the vehicle and outputs various operation signals necessary for navigation.
The control device 3 includes a CPU 3a, a ROM 3b, a RAM 3c, and the like. The control device 3 captures current location coordinate data from the GPS receiver 1 and a key input signal from the key input unit 2, and displays a current location name to be described later. Perform arithmetic processing. When a destination is set using the key input unit 2, a direction to the destination and a distance to the destination are obtained, and a calculation process for displaying the distance is also executed.
[0010]
As shown in FIG. 2, the ROM 3b stores point coordinates and place names or name data of the place names for each of the plurality of points. Data in the ROM 3b is searched.
The display device 4 is installed in the passenger compartment and displays information such as a current location name, a direction to a destination, and a distance. As the display device 4, a liquid crystal display device can be used.
[0011]
FIG. 3 shows a specific configuration of the display device 4 and the key input unit 2.
As shown in the figure, on the display surface of the display device 4, the current location name is displayed on the display unit 4a, the direction of the destination is indicated by an arrow on the display unit 4b, the distance to the destination is displayed on the display unit 4c, and the GPS The number of satellites that can be received by the receiver 1 is displayed on the display unit 4d. The key input unit 2 is provided outside the display frame of the display device 4.
[0012]
FIG. 4 shows a display example on the display device 4. FIG. 4A is an example in which the name of the area including the current location is displayed as the current location name, and FIG. 4B is an example in which the location name near the current location is displayed as the current location name. In addition, the number of artificial satellites that can be received in a small square display on the display unit 4d is shown.
In the above configuration, among the arithmetic processes performed by the CPU 3a, an arithmetic process for displaying the current location name will be described with reference to a flowchart shown in FIG.
[0013]
First, it is determined whether or not the GPS receiver 1 can receive signals from three or more satellites based on a signal from the GPS receiver 1 (step 101). This is because the current location can be specified by receiving from three or more satellites.
Then, when the GPS receiver 1 can receive signals from three or more satellites, the traveling direction θv of the vehicle is calculated from the signal from the GPS receiver 1 (step 102). The traveling direction θv can be obtained from the velocity on the plane of the GPS antenna 1a obtained using the Doppler shift.
[0014]
Next, point coordinates and name data of a point within a predetermined mesh area are read from the current position coordinates of the vehicle and the traveling direction θv based on the signal from the GPS receiver 1 (step 103).
More specifically, a mesh obtained by dividing an area represented by a longitude-latitude coordinate system into mesh-like small sections into equal shapes or equal areas (for example, as shown in FIG. 6, an area of about 1 square kilometer per mesh). ), The longitude and latitude coordinates defining the mesh area, the current position coordinates of the vehicle, and the traveling direction θv of the vehicle are used to specify the mesh area where the current location of the vehicle is located and the mesh area in the traveling direction. Then, the point coordinates and name data of points (indicated by black dots in the figure) in these mesh areas are sequentially read.
[0015]
The mesh area is specified by, for example, specifying that the current position is within the (2, B) mesh area based on the current position coordinates and the longitude / latitude coordinates defining the mesh area in FIG. In the case of (1), the (2, C) mesh area on the right) is specified, and the (1, C) and (3, C) mesh areas that are orthogonal to each other in the traveling direction of the vehicle are specified. When there is no point in these mesh areas, the vehicle further extends in the traveling direction of the vehicle and specifies the (1, D), (2, D), and (3, D) mesh areas.
[0016]
Thereafter, a process of specifying a nearby point in the traveling direction of the vehicle is executed for the extracted points. That is, when the number of the extracted points is n, the processing after step 104 is repeated n times.
First, from the coordinates of the i-th point, a declination θi in the direction of the point from the current position with respect to the traveling direction θv of the vehicle is calculated (step 104). The declination angle θi indicates an absolute value of an angle (a positive value when the point direction is on the right and a negative value when the point direction is on the left) with respect to the traveling direction θv with respect to the traveling direction θv of the vehicle. is there.
[0017]
Next, it is determined whether the declination θi is equal to or smaller than a predetermined angle, that is, whether the point is within a predetermined angle range with respect to the traveling direction θv (step 105). If the declination θi is equal to or smaller than the predetermined angle, the distance is calculated according to Equation 1 (Step 106).
[0018]
(Equation 1)
Di = di + k · θi
Here, di is a linear distance between the current position coordinates and the coordinates of the i-th point, and is obtained by calculation using the respective coordinates. K is a weighting coefficient for converting the argument θi into a distance. Therefore, the distance data Di obtained by Expression 1 is obtained by changing the linear distance between the current position and the destination to a value corresponding to the argument. It should be noted that distance data Di with a weight placed on either the linear distance or the declination can be obtained depending on the magnitude of the weighting coefficient k.
[0019]
Next, the distance data Di is updated (step 107). More specifically, every time the distance data Di is calculated, the distance data Di is compared with the previous minimum value, and when the calculated distance data Di is smaller, the process of updating and storing the distance data Di as the minimum value is performed. .
By repeating the above process n times, the point i having the minimum distance data Di is specified.
[0020]
When it is determined that n processes have been completed (step 108), the current location name is displayed on the display device 4 based on the name data of the point i having the minimum distance data Di (step 109).
If the declination θi is larger than the above-mentioned predetermined angle in the processing of step 105, it is determined that the point is not in the traveling direction of the vehicle, and the distance calculation according to the formula 1 is not performed.
[0021]
For example, when the predetermined angle is set to 90 °, as shown in FIG. 7A, a point within a 180 ° range (shaded area in the figure) immediately behind the vehicle is a mask, that is, the current point. Excluded from display target points for performing place name display. When the predetermined angle is set to 45 °, a point within a range of 270 ° (a hatched area in the figure) is outside the display target point as shown in FIG. 7B.
[0022]
Accordingly, by appropriately setting the predetermined angle, the display target point in the traveling direction of the vehicle can be appropriately extracted, and the display of the current location name at a point or the like where the vehicle has passed can be prohibited.
(2nd Embodiment)
In the second embodiment, the point closest to the current position is specified from the points within a predetermined angle range with respect to the traveling direction of the vehicle without weighting the distance based on the declination θi as described above. The place name is displayed.
[0023]
FIG. 8 shows a flowchart for performing the processing.
Steps 201 to 203 are provided instead of the processing of steps 104 to 108 in FIG. In step 201, a point closest to the current position is specified based on the current position coordinates and the point coordinates of each point. Next, the declination θ of the direction of the point with respect to the traveling direction θv of the vehicle is calculated (step 202), and it is determined whether or not the declination θ is equal to or smaller than a predetermined angle (step 203). The processing in steps 202 and 203 is the same as the processing in steps 104 and 105 in FIG.
[0024]
When the declination θ is equal to or less than the predetermined angle, the current position name is displayed based on the name data of the point, assuming that the point is within a predetermined angle range with respect to the traveling direction of the vehicle (step 109).
However, when the declination θ is larger than the predetermined angle, the process returns to step 201 to specify a point close to the current location among the points excluding that point, and to determine the angle using the declination θ in the same manner as described above. I do.
[0025]
In this way, the point closest to the current position is specified from the points within a predetermined angle range with respect to the traveling direction of the vehicle, and thereby the current position name is displayed.
In the first and second embodiments described above, the current position is detected using a GPS receiver. However, the present position is calculated using a direction sensor such as a gyro, a distance sensor, or the like. Is also good.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram showing a first embodiment of the present invention.
FIG. 2 is a diagram illustrating a storage configuration of point coordinates and name data.
FIG. 3 is a diagram showing a configuration of a display device 4 and a key input unit 4 in FIG.
FIG. 4 is a view showing a display example of the display device 4;
FIG. 5 is a flowchart showing a calculation process for displaying a current location name by a CPU 3a in FIG. 1;
FIG. 6 is a diagram for explaining point extraction in a mesh area.
FIG. 7 is a diagram for explaining a range outside a display target point.
FIG. 8 is a flowchart illustrating a current location name display calculation process according to the second embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... GPS receiver, 2 ... Key input part, 3 ... Control device, 4 ... Display device.

Claims (2)

Current position detecting means (1) for outputting current position coordinate data indicating the current position of the vehicle;
Storage means (3b) for each of the plurality of points, storing point coordinates and name data for the points;
Traveling direction detecting means (102) for detecting the traveling direction of the vehicle;
A point specifying means (103 to 108 ) for specifying, based on the point coordinates and the current position coordinates, a proximity point close to the current position among points within a predetermined angle range with respect to the detected traveling direction of the vehicle; ,
Display means (4) for displaying a name based on the name data of the specified proximity point,
The point identification means determines a deviation between the direction of the point with respect to the current position and the detected traveling direction of the vehicle (104), and determines whether the deviation is within a predetermined angle range . (105) and means (106) for calculating a distance between the point and the current location when the declination is within the predetermined angle range, and changing the distance to a value corresponding to the declination. A vehicle navigation device for identifying the proximity point based on the changed distance . The point specifying means has means (103) for specifying an area in the direction of travel based on the detected direction of travel, and specifying the proximity point to a point in the specified area. The vehicle navigation device according to claim 1 , wherein:

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