JP3517364B2 - Navigation system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a navigation system capable of performing appropriate guidance even at a guidance point with poor visibility during route guidance.

[0002]

2. Description of the Related Art In a navigation system for guiding the traveling of a vehicle, a traveling route between a vehicle's current position and an input destination is searched under predetermined conditions, and an intersection or the like (guidance point) where the traveling direction changes. In, travel guidance is provided as appropriate. In addition to the two-dimensional map display (planar map display) on the liquid crystal display element for driving guidance, the guide point is displayed in a three-dimensional map (three-dimensional map display) at an appropriate timing (point) before the guide point. Alternatively, there is a device that displays a bird's-eye view map and provides voice guidance such as right turn and left turn.

[0003]

In the conventional navigation system, if a guide point with poor visibility is displayed in a three-dimensional map, it is difficult to see the roads to be driven due to the surrounding buildings and the like displayed three-dimensionally. There is a problem.

Further, when the bird's-eye view map is displayed, there is also a problem that the view angle of the road is difficult to see due to an inappropriate view angle and a building or the like.

Further, at such a guide point with poor visibility, there is a problem that the driver's recognition is delayed and the driver is rushed to the guide point even if the guide is given by display or voice.

It is an object of the present invention to provide a navigation system capable of providing guidance output at appropriate timing even at a guidance point with poor visibility and displaying the guidance point appropriately. Moreover, it aims at providing the map recording medium for providing the said navigation system.

[0007]

In order to achieve the above object, the present invention provides a navigation system having route guidance means for outputting guidance information before a guidance point on a preset route. Is characterized in that the area type to which the guide point belongs is specified based on the map data storage means, and the timing for outputting the guide information is set according to the area type.

Further, in the navigation system having route guidance means for outputting guidance information before the guidance point on the preset route, the route guidance means determines the area type to which the guidance point belongs based on the map data storage means. It is characterized by further comprising display switching means for switching the display of the guidance point between the three-dimensional display and the two-dimensional display according to the area type.

Further, in a navigation system having route guidance means for outputting guidance information before a guidance point on a preset route, the route guidance means determines the area type to which the guidance point belongs based on the map data storage means. It is characterized in that it is provided with a display switching means for switching the looking-down angle for bird's-eye view display of the guide point, which is specified.

Further, it is characterized in that the vehicle is provided with a returning means for returning to the original display state when the vehicle passes through the guide point.

Further, when the first guide point to be guided and the second guide point next to the first guide point are close to each other within a predetermined distance, the vehicle passes through the first guide point. It is characterized by further comprising a return prohibiting means for prohibiting the return of the original display state by the returning means even after the above.

[0012]

[0013]

[0014]

[0015]

[0016]

[0017]

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

1 is a block diagram showing the configuration of a navigation system according to a first embodiment of the present invention. Hereinafter, description will be given with reference to the drawings.

Reference numeral 11 is a GP for receiving radio waves from artificial satellites.
It is an S receiver. Reference numeral 12 is a direction sensor such as a gyro sensor for detecting the traveling direction of the vehicle. Reference numeral 13 is a distance sensor for detecting the traveling distance of the vehicle. 14 is a CD-ROM or a DVD (Digital V) on which map information is recorded.
It is a map database consisting of a video disk and its reading device. Reference numeral 2 denotes a current position detection unit 21 that performs a process of identifying the own vehicle position based on the radio wave received by the GPS receiver 11 and the map database 14, a route search unit 22 that searches for a travel route to an input destination, and a search. The control unit is configured by a microcomputer or the like including a route guide unit 23 that guides the vehicle along the determined route. The control unit 2 has display means for displaying map information on the display unit 41 based on the map database 14 for two-dimensional map display (planar map display) or three-dimensional map display (three-dimensional map display). . An input unit 31 is composed of operation switches and the like for setting a destination and the like. Reference numeral 41 is a display unit configured by a liquid crystal display panel or the like for displaying map information based on a signal from the control unit 2. Reference numeral 42 is a voice output unit for synthesizing voice for guidance based on an instruction from the control unit 2 and for performing voice guidance using a speaker or the like.

FIG. 2 is a diagram for explaining the visibility,
(A) is a figure which shows the relationship between a road condition and visibility, (b) is a figure which shows the relationship between an area (area) condition and visibility.
FIG. 3 is a diagram for explaining a road condition, FIG. 3A is a diagram showing a road network, and FIG. 3B is a diagram showing a layout of buildings at intersections. FIG. 4 is a diagram showing an example of various data recorded in the map database, (a) is node data, and (b) is
Is link data, (c) is building data, and (d) is area data. FIG. 5 is a diagram for explaining a method of calculating the visibility from building data, (a) is a building layout diagram,
(B) is a method of predicting the visibility from the number of buildings, (c)
Is a method of predicting visibility based on a combination of multiple conditions. Hereinafter, description will be given with reference to the drawings.

First, the visibility of the guidance point will be described. As shown in Fig. 2 (a), high buildings are densely located at the intersections, there is a road with a narrow road in the left rear direction, and the intersection A has poor visibility, and the roads are relatively wide and there are few buildings that obstruct the view. There is an intersection C with good visibility. In this way, an intersection with poor visibility is set to a visibility of 1, and an intersection with a good visibility is set to a visibility of 3, and the road is relatively wide, but there is a building that obstructs the field of view at the intersection. And rank it. Then, the visibility for each intersection along with the node data, link data, and building data is recorded on the CD.
-Record on a disc (map recording medium) such as ROM or DVD.

In the node data, as shown in FIG. 4A, the name of the intersection, the position of the intersection, the road starting from this intersection, the road ending at this intersection, and the visibility are recorded corresponding to the intersection numbers. . For example, at the intersection number 3, there is a tall building and the visibility is 1 (the visibility is poor). still,
In this case, the visibility is determined by the intersection number without considering the traveling direction of the vehicle, and the visibility is 1 regardless of the direction from which the intersection number is 3.

In the link data, as shown in FIG. 4B, the start node number, the end node number,
The road length, road type (national road, prefectural road, etc.) and end node visibility are recorded. For example, at the end node of the road number (intersection number 3), the visibility is 1 (the visibility is poor).
Is. In addition, the visibility in this case is determined in consideration of the traveling direction of the vehicle, and in the case of heading to the intersection from the left side with respect to the intersection of number 3 (going from intersection number 1 to intersection number 3 by road number) The degree of visibility.

In the building data, the building name, building center position, site data, height data, and related intersection number are recorded corresponding to the building number as shown in FIG. 4 (c). For example, in the building number (a), name XX building, position X01,
Y01, site 10x25m, height 20m, related intersection number 3. Intersection corresponding to the guidance point (relationship intersection)
The building in is extracted and the visibility is calculated based on the above data. The details of the calculation method will be described later with reference to FIG.

Regarding visibility of guidance point Instead of recording visibility data of each intersection on a map recording medium,
There is also a method in which the visibility that represents the entire region is determined and all the intersections that belong to that region have the same visibility. For example, as shown in Fig. 2 (b), in general, there are many high-rise buildings in a city area, and there are many intersections with poor visibility. In this area (city area), there are buildings that block the view in area 1 (area type 1) and in the suburbs. There are few intersections with good prospects, this area (suburbs) is in Area 3 (regional type 3), and there are many mid-rise buildings in the suburbs, and there are many prospects in this area (suburbs). Classify as area type 2). Then, the range to which each area belongs is recorded as area data on a disk (map recording medium) such as a CD-ROM or a DVD as shown in FIG. 4D. It should be noted that each area is a range surrounded by designated points, and is a polygon based on the usage type and topography such as administrative districts (ward names, town names, etc.), commercial areas, residential areas, and the like. Although this method slightly lowers the accuracy because the visibility is assumed from the area without obtaining the visibility of each guidance point, the visibility data is recorded because it is specified not in the individual intersection but in the area to which the intersection belongs. It's easy. Further, even if the visibility data is not recorded on the map recording medium, there is an advantage that the navigation system can estimate the visibility by associating the corresponding ward name, town name, etc. from the normal map data with the read area.

Next, instead of reading the visibility of the intersection directly from the map database as visibility data, there is a method of calculating the visibility from the building data of the map database. For example, in the building layout diagram at the intersection shown in FIG. 5A, the number of buildings within a predetermined area (the range of the rectangle indicated by the dotted line) from the related intersection is calculated. Based on the calculation result, the visibility is set corresponding to the number of buildings as shown in FIG. This is because the more buildings near the intersection, the worse the visibility. At the intersection shown in FIG. 5A, the number of buildings is 13 and the visibility is 1. In this method, the size and height of the building are not taken into consideration and the accuracy is low, but there is an advantage that the visibility can be easily calculated.

A method of accurately calculating the visibility from the building data is, for example, in the building layout diagram at the intersection shown in FIG. 5A, the individual buildings at the relevant intersections are located before the intersection in the traveling direction of the vehicle. Figure out the building
The relevant building data (building position, height, size) is read from the building data in (c), and road data (road connection angle, road width) is read from the map database, and the visibility is calculated based on the visibility calculation formula (1). Calculate the degree. In addition, (1)
In the equation, L is a coefficient according to the distance between the intersection and the position of the building, the closer the visibility is, the higher the coefficient is according to the height of the building, the poorer the visibility, and S is the size of the building. The larger the coefficient is, the poorer the visibility is. The K is a coefficient according to the connection angle of the advancing road, and the opposite is bad, and the W is the coefficient depending on the road width of the advancing road. Has been done.

FIG. 6 is a flowchart of the processing performed by the control unit of the navigation system according to the first embodiment of the present invention. Hereinafter, description will be given with reference to the drawings. In this example, the timing of outputting the necessary guide information is changed according to the visibility of the guide point. In detail, when a predetermined distance before the guide point is reached, the display form is changed from the planar route map displayed while driving to the (enlarged) stereoscopic view or bird's-eye view near the guide point, or the voice turns right or left. Guidance such as instructions is output, but near the guidance point with poor visibility (early)
The guide information is output by so that the driver does not panic at the guide point. In addition, this processing starts at the time when the destination is input by the navigation system.

In step S101, the destination is set and the process proceeds to step S102. That is, the destination input by the user is read. In step S102, a route search is performed and the process proceeds to step S103. That is, the current position detection unit 21 detects the current position of the vehicle based on the radio wave received by the GPS receiver 11 and the map database 14. When GPS radio waves cannot be received in a tunnel or the like, the position is detected by the azimuth sensor 12 and the distance sensor 13. Then, the traveling route is searched for according to a predetermined method (for example, a route having the shortest distance, a route passing through a predesignated point, etc.) based on the detected current position and the input destination.

In step S103, the guide point is extracted and the process proceeds to step S104. That is, the guide point closest to the current position on the searched travel route is obtained. The guidance point is an important point for route guidance, and is, for example, an intersection that makes a right turn or a left turn, a connection point with different road types (national roads, prefectural roads, etc.), or an intersection with complicated road connection angles. In step S104, the visibility is read out or calculated to calculate in step S1.
Move to 05. That is, the visibility of the corresponding guidance point (the visibility of the node data (a) of FIG. 4 and the end node visibility of the link data of (b) of FIG. 4) is read out from the map database 14 or is read from the map database 14. Based on the building information (building data (c) of FIG. 4) of the guide point and the road information, the visibility is calculated according to the visibility prediction method of FIG. 5B or 5C.

In step S105, it is determined whether the visibility is 3, and if the visibility is 3, step S1
07, if the visibility is not 3, step S106
Move on to. That is, it is determined whether the visibility of the guidance point read from the map database 14 or the visibility calculated based on the building data and the road data of the guidance point read from the map database 14 is the best 3.
In step S106, it is determined whether the visibility is 2, and if the visibility is 2, the process proceeds to step S108.
If the visibility is not 2 (that is, the visibility is 1), the process proceeds to step S109.

In step S107, guidance is output 300 m before and the process returns to step S103. That is, since the guidance point has good visibility (line-of-sight 3), the guidance information is output at a point closer to the guidance point. When the distance between the vehicle position detected by the navigation system and the guide point on the map database 14 reaches 300 m, the guide information is output. As the guidance output, for example, the map (planar map) displayed on the display unit 41 is switched to (enlarged) three-dimensional map display or bird's-eye view map display so that the shape of the guidance point can be easily understood.
Also, voice guidance such as right turn and left turn is given. Step S10
In step 8, guidance output is performed 350 m before step S10.
Return to 3. That is, since the guidance at the guidance point is normal (the visibility is 2), the guidance information is output to the guidance point at a point before the normal distance. In step S109, guidance is output 400 m before and the process returns to step S103. In other words, if the guidance point has poor visibility (line-of-sight 1) and the guidance information is output before the normal distance from the guidance point, it will take time for the driver to recognize and determine the travel route, so that the driver can make a judgment in a comfortable manner. The guidance information is output to the front of the usual guidance point.

As described above, in the present embodiment, the guide information is output earlier than usual at the guide point with poor visibility, so that the guide point is not confused.

FIG. 7 is a flow chart of processing performed by the control unit of the navigation system according to the second embodiment of the present invention. Hereinafter, description will be given with reference to the drawings. In this example, the timing of outputting the necessary guide information is changed according to the area (area) type to which the guide point is estimated to have a correlation with the visibility. In addition, this processing starts at the time when the destination is input by the navigation system.
The system configuration is the same as in the first embodiment.

In step S201, the destination is set and the process proceeds to step S202. That is, the destination input by the user is read. In step S202, a route search is performed and the process proceeds to step S203. That is, the current position detection unit 21 detects the current position of the vehicle based on the radio wave received by the GPS receiver 11 and the map database 14. When GPS radio waves cannot be received in a tunnel or the like, the position is detected by the azimuth sensor 12 and the distance sensor 13. Then, based on the detected current position and the input destination, the travel route is searched according to a predetermined method.

In step S203, the guide point is extracted and the process proceeds to step S204. That is, the guide point closest to the current position on the searched travel route is obtained. Step S2
In 04, the area type is read and the process proceeds to step S205. That is, the area type (which area of the area data in (d) of FIG. 4) the corresponding guidance point (position X, Y) belongs to is read from the map database 14.

In step S205, it is determined whether or not the area is 3, and if the area is 3, it is determined in step S207.
If the area is not 3, the process proceeds to step S206. That is, it is determined whether the guide point read from the area data of the map database 14 belongs to the area 3. In step S206, it is determined whether the area is 2, and if the area is 2, the process proceeds to step S208, and if the area is not 2 (that is, area 1), the process proceeds to step S209. That is, it is determined whether the guidance point read from the area data of the map database 14 belongs to the area 2.

In step S207, guidance is output 300 m before and the process returns to step S203. That is, since the guide point is the area 3 with good visibility, the guide information is output at a point closer to the guide point. When the distance between the vehicle position detected by the navigation system and the guide point on the map database 14 reaches 300 m, the guide information is output. In step S208, guidance is output 350 m before and the process returns to step S203. That is, since the guide point is the area 2 where the line of sight is normal, the guide information is output to the guide point before the normal distance. In step S209, guidance is output 400 m before and the process returns to step S203. In other words, since the guidance point is the area 1 with poor visibility, if the guidance information is output before the normal distance from the guidance point, it takes time for the driver to recognize and determine the traveling route, so that the driver can make a judgment in a comfortable manner. The guidance information is output to the front of the usual guidance point.

As described above, in the present embodiment, the guide information is output earlier than usual at the guide point belonging to the area where the visibility is assumed to be poor, so that the guide point will not be confused.

FIG. 8 is a flowchart of the processing performed by the control unit of the navigation system according to the third embodiment of the present invention. Hereinafter, description will be given with reference to the drawings. In this example, the driver changes the plan map displayed while driving according to the visibility of the guide point to a three-dimensional map display or a plan map display near the guide point so that the driver can accurately understand the situation at the guide point. It makes it possible to grasp. Then, when the vehicle passes through the guide point, the original display state is restored. In addition, this processing starts at the time when the destination is input by the navigation system.

In step S301, the destination is set and the process proceeds to step S302. That is, the destination input by the user is read. In step S302, a route search is performed and the process proceeds to step S303. That is, the current position detection unit 21 detects the current position of the vehicle based on the radio wave received by the GPS receiver 11 and the map database 14. When GPS radio waves cannot be received in a tunnel or the like, the position is detected by the azimuth sensor 12 and the distance sensor 13. Then, based on the detected current position and the input destination, the travel route is searched according to a predetermined method.

In step S303, the guide point is extracted and the process proceeds to step S304. That is, the guide point closest to the current position on the searched travel route is obtained. The guidance point is an important point for route guidance, and is, for example, an intersection that makes a right turn or a left turn, a connection point with different road types (national roads, prefectural roads, etc.), or an intersection with complicated road connection angles. In step S304, the visibility is read out or calculated to calculate in step S3.
Move to 05. That is, the visibility of the corresponding guidance point (the visibility of the node data (a) of FIG. 4 and the visibility of the end node of the link data of (b) of FIG. 4) is read from the map database 14, or Based on the building information (building data (c) of FIG. 4) of the guide point and the road information, the visibility is calculated according to the visibility prediction method of FIG. 5B or 5C.

In step S305, it is determined whether the visibility is 2 or more (the visibility 2 or 3). If the visibility is 2 or more, the process proceeds to step S306, and the visibility is not 2 or more (that is, the visibility is 2 or more). , Visibility 1) Step S30
Go to 7. That is, the determination is made based on the visibility of the guide point read from the map database 14, or the visibility calculated based on the building data and road data of the guide point read from the map database 14.

In step S306, three-dimensional (three-dimensional) guidance display is performed and the process returns to step S303. That is, the visibility of the guidance point is good (the visibility is 3 or 2), so that the traveling route is not blocked by a building or the like, and therefore the vicinity of the guidance point is displayed in a three-dimensional map so that the driver can easily recognize it. In step S307, two-dimensional (planar) guidance display is performed and the process returns to step S303. That is, since the traveling route of the guide point is blocked by a building or the like and visibility is poor (line-of-sight 1), a two-dimensional map is displayed so that the driver does not easily display the building near the guide point so that the driver can easily recognize the traveling route. .

In step S308, it is judged whether or not the vehicle has passed the guide point, and if the vehicle has passed the guide point, step S3.
It moves to 09 and waits if it has not passed the guidance point yet. This determination is made by comparing the present location of the vehicle with the guidance point by the navigation system. In step S309, the original dimension is switched to, and the process returns to step S303. That is, since the vehicle has passed the guide point to be guided, the display of the guide point is returned to the previous display state.

As described above, in the present embodiment, the two-dimensional map display and the guidance with good visibility such that the building is not displayed at the guidance point with poor visibility so that the traveling route at the guidance point, especially the state of the road, can be easily recognized. By displaying a three-dimensional map showing a building at a point, it becomes easier to recognize the travel route. Further, the switched display state can be automatically returned to the original display state when passing the guide point.

In this example, the situation near the guide point is displayed in the three-dimensional map or the two-dimensional map according to the visibility, but instead of the visibility, the guidance is provided as in the second embodiment. The display dimensions may be switched depending on the area to which the point belongs. For example, instead of determining whether the visibility is 2 or more in step S305, it may be determined whether the area is 2 or more.

FIG. 9 is a flowchart of the processing performed by the control unit of the navigation system according to the fourth embodiment of the present invention. Hereinafter, description will be given with reference to the drawings. In this example, the driver changes the plan map displayed while driving according to the visibility of the guide point to a three-dimensional map display or a plan map display near the guide point so that the driver can accurately understand the situation of the guide point. It makes it possible to grasp. Then, when a predetermined time elapses after the display is switched, the original display state is restored. In addition, this processing starts at the time when the destination is input by the navigation system.

In step S401, the destination is set and the process proceeds to step S402. That is, the destination input by the user is read. In step S402, a route search is performed and the process proceeds to step S403. That is, the current position detection unit 21 detects the current position of the vehicle based on the radio wave received by the GPS receiver 11 and the map database 14. When GPS radio waves cannot be received in a tunnel or the like, the position is detected by the azimuth sensor 12 and the distance sensor 13. Then, based on the detected current position and the input destination, the travel route is searched according to a predetermined method.

In step S403, the guide point is extracted and the process proceeds to step S404. That is, the guide point closest to the current position on the searched travel route is obtained. The guidance point is an important point for route guidance, and is, for example, an intersection that makes a right turn or a left turn, a connection point with different road types (national roads, prefectural roads, etc.), or an intersection with complicated road connection angles. In step S404, the visibility is read out or calculated to calculate in step S4.
Move to 05. That is, the visibility of the corresponding guidance point (the visibility of the node data (a) of FIG. 4 and the visibility of the end node of the link data of (b) of FIG. 4) is read from the map database 14, or Based on the building information (building data (c) of FIG. 4) of the guide point and the road information, the visibility is calculated according to the visibility prediction method of FIG. 5B or 5C.

In step S405, it is determined whether the visibility is 2 or more (the visibility 2 or 3). If the visibility is 2 or more, the process proceeds to step S406.
If the visibility is not 2 or more (that is, the visibility is 1), the process proceeds to step S407. That is, the determination is made based on the visibility of the guide point read from the map database 14, or the visibility calculated based on the building data and road data of the guide point read from the map database 14.

In step S406, three-dimensional (three-dimensional) guide display is performed, and the process returns to step S403. That is, the visibility of the guidance point is good (the visibility is 3 or 2), so that the traveling route is not blocked by a building or the like, and therefore the vicinity of the guidance point is displayed in a three-dimensional map so that the driver can easily recognize it. In step S407, two-dimensional (planar) guidance display is performed and the process returns to step S403. That is, since the traveling route of the guide point is blocked by a building or the like and visibility is poor (line-of-sight 1), a two-dimensional map is displayed so that the driver does not easily display the building near the guide point so that the driver can easily recognize the traveling route. .

In step S408, the time counting by the timer is started, and the process proceeds to step S409. That is, it is for determining whether or not the predetermined time T has elapsed. Step S40
In 9, it is determined whether or not a predetermined operation is performed, and if the predetermined operation is performed, the process returns to step S503, and if the predetermined operation is not performed, the process proceeds to step S410. The predetermined operation is an operation for continuing the switched display state even after a predetermined time T has elapsed, and it is determined whether or not any key is operated.

In step S410, it is determined whether or not the predetermined time T has elapsed. If the predetermined time T has elapsed, the process proceeds to step S411, and if the predetermined time T has not elapsed, the process returns to step S409. That is, it corresponds to whether or not the current display is continued even if the predetermined time T has elapsed. In step S411, the original dimension is switched to step S40.
Return to 3. That is, since the predetermined time T has passed since the display was switched, the display of the guide point is returned to the previous display state.

As described above, in the present embodiment, the two-dimensional map display and the guidance with good visibility such that the building is not displayed at the guidance point with poor visibility so that the traveling route at the guidance point, particularly the state of the road, can be easily recognized. By displaying a three-dimensional map showing a building at a point, it becomes easier to recognize the travel route. Further, it is possible to select whether or not to continue the switched display state.

In this example, the situation around the guide point is displayed as a three-dimensional map or a two-dimensional map according to the visibility, but instead of the visibility, guidance is provided as in the second embodiment. The display dimensions may be switched depending on the area to which the point belongs. For example, instead of determining whether the visibility is 2 or more in step S405, it may be determined whether the area is 2 or more.

FIG. 10 is a flow chart of processing performed by the control unit of the navigation system according to the fifth embodiment of the present invention. FIG. 11 is a diagram showing a display example of the navigation system according to the fifth embodiment of the present invention. (A) is a 30-degree bird's-eye view display, (b) is a 60-degree bird's-eye view display, and (c) is a 90-degree bird's-eye view display. It is a figure. Hereinafter, description will be given with reference to the drawings. In this example, the plane map displayed while driving according to the visibility of the guide point is changed to a bird's-eye view map with a different looking down angle near the guide point so that the driver can see the situation of the guide point accurately. It makes it possible to grasp. Then, when the vehicle passes through the guide point, the original display state is restored. In addition, this processing starts at the time when the destination is input by the navigation system.

In step S501, the destination is set and the process proceeds to step S502. That is, the destination input by the user is read. In step S502, a route search is performed and the process proceeds to step S503. That is, the current position detection unit 21 detects the current position of the vehicle based on the radio wave received by the GPS receiver 11 and the map database 14. When GPS radio waves cannot be received in a tunnel or the like, the position is detected by the azimuth sensor 12 and the distance sensor 13. Then, based on the detected current position and the input destination, the travel route is searched according to a predetermined method.

In step S503, the guide point is extracted and the process proceeds to step S504. That is, the guide point closest to the current position on the searched travel route is obtained. The guidance point is an important point for route guidance, and is, for example, an intersection that makes a right turn or a left turn, a connection point with different road types (national roads, prefectural roads, etc.), or an intersection with complicated road connection angles. In step S504, the visibility is read out or calculated to calculate in step S5.
Move to 05. That is, the visibility of the corresponding guidance point (the visibility of the node data (a) of FIG. 4 and the visibility of the end node of the link data of (b) of FIG. 4) is read from the map database 14, or Based on the building information (building data (c) of FIG. 4) of the guide point and the road information, the visibility is calculated according to the visibility prediction method of FIG. 5B or 5C.

In step S505, it is determined whether the visibility is 3, and if the visibility is 3, step S5
Moving to 07, if the visibility is not 3, step S506
Move on to. That is, it is determined whether the visibility of the guidance point read from the map database 14 or the visibility calculated based on the building data and the road data of the guidance point read from the map database 14 is the best 3.
In step S506, it is determined whether or not the visibility is 2, and if the visibility is 2, the process proceeds to step S508,
If the visibility is not 2 (that is, the visibility is 1), the process proceeds to step S509.

In step S507, the looking-down angle 30
A bird's-eye view map is displayed every time and the process returns to step S503. In other words, the visibility of the guidance point is good (line-of-sight 3), so the driving route is not blocked by buildings, etc., so that the driver can easily recognize the bird's-eye view map with a downward angle of 30 degrees (see the figure). 11 (a)). Step S50
In 8, the bird's-eye view map is displayed with a look-down angle of 60 degrees, and the process returns to step S503. In other words, since the guidance point has a medium visibility (line-of-sight 2), the travel route is slightly obstructed by buildings and the like, and the bird's-eye view map is displayed with the angle of 60 degrees looking down so that the driver can easily recognize it (( Figure 11
(See (b)). In step S509, the looking-down angle 9
A bird's-eye view map is displayed at 0 degree and the process returns to step S503. In other words, since the travel route at the guide point is blocked by a building or the like and visibility is poor (line-of-sight 1), a bird's-eye view with a 90-degree angle is looked down so that the driver cannot easily recognize the drive route and the building is not displayed near the guide point. Display the map (Fig. 11 (c))
reference).

In step S510, it is determined whether the vehicle has passed the guide point, and if the vehicle passes the guide point, step S5.
It moves to 11 and waits if it has not passed the guidance point yet. This determination is made by comparing the present location of the vehicle with the guidance point by the navigation system. In step S511, the original dimension is switched to, and the process returns to step S503. That is, since the vehicle has passed the guide point to be guided, the display of the guide point is returned to the previous display state.

As described above, in the present embodiment, a bird's-eye view map display and a line-of-sight view with a large looking-down angle such that a building is not displayed at a guide point with poor visibility so that it is easy to recognize the travel route, especially the state of the road At a good guide point, a bird's-eye view map with a small view angle for displaying a building is displayed to make it easier to recognize the travel route. Further, the switched display state can be automatically returned to the original display state when passing the guide point.

In this example, the bird's-eye view map with different angles is looked down in the vicinity of the guidance point according to the visibility, but instead of the visibility, the bird's-eye view map is displayed as in the second embodiment. The display state may be switched depending on the area to which it belongs. For example, step S505, step S
In 506, instead of the determination of the visibility of 3 or 2, the determination of the area of 3 or 2 may be performed. Further, in this example, after the bird's-eye view map display with a different angle is looked down near the guide point, the original display is restored when passing through the guide point. However, as in the fourth embodiment, the predetermined time is displayed. The display may be returned to the original display after a lapse of time.

FIG. 12 is a flowchart of the processing performed by the control unit of the navigation system according to the sixth embodiment of the present invention. FIG. 13 is an explanatory diagram of the approach guidance point. Hereinafter, description will be given with reference to the drawings. In this example, the plane map displayed while driving according to the visibility of the guide point is changed to a bird's-eye view map with a different looking down angle near the guide point so that the driver can see the situation of the guide point accurately. It makes it possible to grasp. Furthermore, when the two guide points are close to each other, the timing of passing through the guide points and returning to the original display state is taken into consideration. In addition, this processing starts at the time when the destination is input by the navigation system.

In step S601, the destination is set and the process proceeds to step S602. That is, the destination input by the user is read. In step S602, a route search is performed and the process proceeds to step S603. That is, the current position detection unit 21 detects the current position of the vehicle based on the radio wave received by the GPS receiver 11 and the map database 14. When GPS radio waves cannot be received in a tunnel or the like, the position is detected by the azimuth sensor 12 and the distance sensor 13. Then, based on the detected current position and the input destination, the travel route is searched according to a predetermined method.

In step S603, the guide point is extracted and the process proceeds to step S604. That is, the guide point closest to the current position on the searched travel route is obtained. The guidance point is an important point for route guidance, and is, for example, an intersection that makes a right turn or a left turn, a connection point with different road types (national roads, prefectural roads, etc.), or an intersection with complicated road connection angles.

In step S604, it is determined whether or not the two guide points are close to each other. If they are close to each other, the process proceeds to step S606. If they are not close to each other, the process proceeds to step S605. As shown in FIG. 13, when the guide point A on the front side and the guide point B on the next side are approaching (below a predetermined distance) as shown in FIG. 13, the display state is returned to the original display state after passing the guide point A, and the next guide point immediately after. This is because when the display is switched close to B, the display is frequently switched and the driver is confused. This is to prevent this. Whether or not the two guide points are close to each other is determined by the positions (distances) of the two guide points on the navigation system.

In step S606, the guide point A in front is
Read out or calculate the visibility of step S60
Go to 7. That is, the visibility of the corresponding guidance point (the visibility of the node data (a) of FIG. 4 and the visibility of the end node of the link data of (b) of FIG. 4) is read from the map database 14, or Based on the building information (building data (c) of FIG. 4) of the guide point and the road information, the visibility is calculated according to the visibility prediction method of FIG. 5B or 5C.

In step S607, it is determined whether the visibility is 3, and if the visibility is 3, then step S6.
09, and if the visibility is not 3, step S608
Move on to. That is, it is determined whether the visibility of the guidance point read from the map database 14 or the visibility calculated based on the building data and the road data of the guidance point read from the map database 14 is the best 3.
In step S609, it is determined whether or not the visibility is 2, and if the visibility is 2, the process proceeds to step S610.
If the visibility is not 2 (that is, the visibility is 1), the process proceeds to step S611.

In step S609, the looking-down angle 30
The bird's-eye view map is displayed every time and the process returns to step S603. That is, the visibility of the guidance point is good (line-of-sight 3), so that the traveling route is not obstructed by buildings or the like, and the bird's-eye view map is displayed with the angle of 30 degrees looking down around the guidance point so that the driver can easily recognize it. In step S610, the looking-down angle 6
The bird's-eye view map is displayed at 0 degrees, and the process returns to step S603. In other words, the visibility of the guidance point is medium (line-of-sight 2), and the traveling route is slightly obstructed by buildings and the like, and the bird's-eye view map with the angle of 60 degrees is looked down so that the driver can easily recognize it. In step S611, a bird's-eye view map with a view angle of 90 degrees is displayed, and the process returns to step S503. In other words, the driving route of the guide point is blocked by a building or the like and visibility is poor (line-of-sight 1), and a bird's-eye view map with a 90-degree angle looking down so that the building is not displayed near the guide point so that the driver can easily recognize the traveling route. Display.

In step S612, it is determined whether or not the next guidance point B has been passed. If the next guidance point B has been passed, the process proceeds to step S613, and if it has not yet passed, the procedure waits. This determination is made by comparing the present position of the vehicle with the guide point B by the navigation system. Step S
At 613, the display is switched back to the original display and the process returns to step S603. That is, since the vehicle has passed the guide point to be guided, the display of the guide point is returned to the previous display state.

In step S605, the same processing as step S504 of the fifth embodiment is performed. In other words, since the two guide points are not close to each other, it is the same as the fifth embodiment when it is determined that the guide points are different. Therefore, step S5
After performing the processing from 04 to step S512, the process returns to step S603 of this embodiment.

As described above, in the present embodiment, a bird's-eye view map display and a line-of-sight view with a large looking-down angle such that a building is not displayed at a guidance point where the visibility is poor so that the traveling route, particularly the state of the road, can be easily recognized. At a good guide point, a bird's-eye view map with a small view angle for displaying a building is displayed to make it easier to recognize the travel route. Also, 2
It is possible to prevent the display from switching frequently even when two guide points are close to each other.

In this example, the bird's-eye view map with different angles is looked down in the vicinity of the guide point according to the visibility, but instead of the visibility, the bird's-eye view map is displayed as in the second embodiment. The display state may be switched depending on the area to which it belongs.

[0081]

As described above, according to the present invention, there is provided a navigation system capable of providing guidance at an appropriate timing even at a guide point with poor visibility and displaying the guide point on an easily recognizable screen according to the visibility. Can be provided.
Further, a map recording medium for providing the above navigation system can be provided.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a navigation system according to a first embodiment of the present invention.

FIG. 2 is a diagram for explaining visibility.

FIG. 3 is a diagram for explaining a road condition.

FIG. 4 is a diagram showing an example of various data recorded in a map database.

FIG. 5 is a diagram for explaining a method of calculating a visibility from building data.

FIG. 6 is a flowchart of processing performed by a control unit of the navigation system according to the first embodiment of this invention.

FIG. 7 is a flowchart of a process performed by a control unit of the navigation system according to the second embodiment of the present invention.

FIG. 8 is a flowchart of processing performed by a control unit of the navigation system according to the third embodiment of this invention.

FIG. 9 is a flowchart of a process performed by a control unit of the navigation system according to the fourth embodiment of the present invention.

FIG. 10 is a flowchart of a process performed by a control unit of the navigation system according to the fifth embodiment of the present invention.

FIG. 11 is a diagram showing a display example of the navigation system according to the fifth embodiment of the present invention.

FIG. 12 is a flowchart of a process performed by a control unit of the navigation system according to the sixth embodiment of the present invention.

FIG. 13 is an explanatory diagram of an approach guidance point.

[Explanation of symbols]

11 ... ・ GPS receiver 22 ... Route search unit 14 ... Map database 23
.... Route guidance unit, 12 ... Direction sensor,
31 ... ・ Input unit, 14 ... ・ Vehicle speed sensor,
41 ... ・ Display unit, 2 ... Control unit, 42 ... Sound output unit, 21 ...
... Current position detector.

─────────────────────────────────────────────────── ─── Continued Front Page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01C 21/00-21/36 G09B 23/00-29/14 G08G 1/00-9/02

Claims (5)

(57) [Claims] 1. A navigation system having route guidance means for outputting guidance information before a guidance point on a preset route, wherein the route guidance means determines an area type to which the guidance point belongs based on a map data storage means. A navigation system characterized by specifying and setting timing for outputting guidance information according to the area type. 2. A navigation system having route guidance means for outputting guidance information before a guidance point on a preset route, wherein the route guidance means determines an area type to which the guidance point belongs based on a map data storage means. Specified, according to the area type,
A navigation system comprising display switching means for switching between three-dimensional display and two-dimensional display of a guide point. 3. A navigation system having route guidance means for outputting guidance information before a guidance point on a preset route, wherein the route guidance means determines the area type to which the guidance point belongs based on a map data storage means. Specified, according to the area type,
A navigation system comprising display switching means for switching a viewing angle for displaying a bird's-eye view of a guidance point. 4. The navigation system according to claim 2, further comprising return means for returning to the original display state when the vehicle passes through the guide point. 5. The vehicle passes through the first guide point when the first guide point to be guided and the second guide point next to the first guide point are close to each other within a predetermined distance. 5. The navigation system according to claim 4, further comprising a return prohibiting unit that prohibits the return unit from returning to the original display state even after the return.