JP3283148B2 - Car 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 an automobile navigation system.

[0002]

2. Description of the Related Art Navigation systems for automobiles have attracted attention as devices that greatly reduce the stress and anxiety of drivers and serve as the core of computerization of automobiles, and the functions provided by them are diverse. A car navigation device is a large-capacity storage device such as a CD-ROM that stores map data of a road network, place names, peripheral facilities, and the like at a multi-step scale;
A current position detection device for detecting the current position of a vehicle equipped with the vehicle navigation device (hereinafter referred to as “own vehicle”) using an S (global positioning system) or a gyro sensor, etc., and an optimal route to the destination And a display device for displaying various information.

[0003] The most basic functions provided by a car navigation system are three points: provision of road information, display of a current position, and guidance to a destination. As a function of providing road information, the navigation device for a car displays a map including a road network and place names on the display and provides information on surrounding facilities and shops. In addition, as a function of displaying the current position, when the driver indicates the current position of the own vehicle on the display, the automobile navigation device places a cursor indicating the current position at a fixed position on the display, and the traveling direction of the own vehicle is constantly changed. The surrounding road network and place names are displayed as a map with the cursor at the center while pointing directly upward. Then, the navigation apparatus for a vehicle causes the map to be scroll-displayed in accordance with the movement of the vehicle.

[0004] Finally, as a guidance function to a destination, when a driver inputs a destination of a movement destination, an automobile navigation device obtains a shortest route from a current position to a destination as a guidance route, and performs actual driving. Sometimes, the driver guides the driver so that the vehicle does not deviate from the guidance route by displaying the guidance route in a different color from other roads or displaying a guidance cursor in front of the vehicle cursor on the display. .

[0005] The guiding function will be described below. The navigation apparatus for automobiles has data for guidance route search called node link data in the CD-ROM. The node link data is data relating to a connection state of the road network, and includes a coordinate value of each node, a connection state between nodes, a distance between adjacent nodes, and a connection of a line connecting the adjacent nodes (hereinafter referred to as a link). And information on the type of road represented by each link (type of expressway, national road, prefectural road, private road, etc.). Here, a node refers to a point important for steering of an automobile in a road network, such as an intersection, a junction / junction of a highway, and a curve curved with a curvature equal to or greater than a predetermined value. The route creation device reads the node link data, performs a route search from the current position to the destination, and sets the shortest route between the two points as a guidance route. The navigation apparatus for a vehicle displays the guidance route on a display in accordance with the progress of the vehicle, and guides the driver.

[0006] In a conventional car navigation system, the destination is set by the following method or the like. : Select a destination from among a large number of public facilities, stores, place names, etc. listed in advance. : A map on which a destination is described is displayed on a display, and a cursor is moved to a destination on the map to set a destination. In the above method, the destination is set as a proper noun such as a building or a place name. In addition, in the above method, the driver rarely sets a destination while consciously specifying the destination on a road, so that the position is set as the destination while the cursor is placed in the middle of a building or a pond. It may be set. Further, even if the destination is designated on a road, the road may be so narrow that cars cannot pass, or it may be one-way or under construction. Furthermore, it is also conceivable that the road leading to the destination is recently created or very narrow and not described in the map data memory.

For this reason, the driver cannot actually drive the vehicle until the current position of the vehicle and the set destination completely match. Therefore, in the guidance function of the navigation apparatus for a vehicle, there is a problem that the point at which the vehicle approaches the destination is regarded as reaching the destination and the guidance is terminated. Therefore, in a conventional car navigation apparatus, a perpendicular is dropped from the destination to a nearby road (link) closest to the destination, and the foot of the perpendicular is used as a temporary destination to automatically reach the temporary destination. A method of guiding a car is used. Alternatively, a method may be used in which the node closest to the destination is regarded as a temporary destination, and the guidance is terminated when the vehicle reaches the temporary destination.

[0008]

By the way, when a conventional car navigation system obtains a temporary destination by the above-described method and ends route guidance without reaching the destination, the destination is located in an urban area. When the road to the destination is complicated, the vehicle often cannot proceed on the way despite the fact that the vehicle is near the destination. In such a case, the driver has to turn back while looking at the map to find a way. For this reason, the conventional automobile navigation apparatus has a drawback in that the driver intends to guide the driver to the vicinity of the destination, but conversely causes the driver to make a long circuit. The present invention has been made under such a background, and an object of the present invention is to provide a navigation apparatus for a vehicle that does not allow a driver to travel unnecessarily even when a road to a destination is complicated. .

[0009]

SUMMARY OF THE INVENTION The present invention provides a present position detecting means for detecting a current position of a vehicle, a road network storing means for storing a road network comprising at least node information and link information, and a destination for setting a destination. An automobile navigation system comprising: a setting unit; a route search unit that searches for a guide route from a current position to a destination based on the road network storage unit; and a guide unit that performs a predetermined guide along the searched guide route. In the device, a perpendicular line is dropped from the destination with respect to the link closest to the destination among the links constituting the guidance route, and the distance between the current position of the vehicle and the destination is calculated from the length of the perpendicular line. A destination arrival determining means for determining that the vehicle has arrived at the destination when the distance is equal to or shorter than the predetermined distance is provided.

[0010]

In the navigation apparatus for a vehicle according to the present invention, the destination arrival determining means drops a perpendicular from the destination to the link closest to the destination among the links constituting the guidance route, and determines the current position of the vehicle. When the distance between the destinations is less than a predetermined distance obtained from the length of the perpendicular,
It is determined that the vehicle has arrived at the destination. Thereby, the distance for determining that the vehicle has arrived at the destination can be changed according to the distance between the destination and the guidance route.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an automobile navigation device according to an embodiment of the present invention. Reference numeral 1 denotes a map data memory. In this embodiment, a CD-ROM drive and a CD-ROM are used as examples. The drawing data 1a and the node link data 1b are recorded on the CD-ROM. The drawing data 1a is map data corresponding to a multi-step scale map from an entire map of the Japanese archipelago to a detailed map of each municipality nationwide.

The node link data 1b is data relating to the connection state of the road, and is composed of the coordinate values of each node, the connection state between nodes, the distance between adjacent nodes, and the connection of links connecting adjacent nodes. And the type of road represented by each link (type of expressway, national road, prefectural road, private road, etc.). Reference numeral 2 denotes a current position locating unit, which is based on data sent from a gyro sensor 2a for detecting the direction of the own vehicle and a vehicle speed detector 2b for detecting the speed of the own vehicle based on the number of rotations of wheels in a predetermined time. Is continuously calculated to determine the current position of the own vehicle. Further, the current position locating unit 2 receives data from the GPS 2c and checks whether the current position obtained by the above method is an accurate value.

A current position memory 3 stores the current position obtained by the current position locating unit 2. Since the current position memory 3 is backed up by a battery (not shown), the current position can be maintained even when the vehicle engine is stopped and power is not supplied to the vehicle navigation apparatus. Reference numeral 4 denotes a destination setting unit, which is used for setting a destination for the vehicle navigation device. The destination setting unit is a scale key for selecting a map (not shown) as an input means for setting a destination.
It has an eight-way input key for moving the cursor and a decision key for determining the destination. The driver selects a map on which the destination is described with the scale key and displays the map on the display. Further, the driver moves the cursor to the destination on the displayed map using the eight-way input keys, and presses the enter key to set the destination.

Reference numeral 5 denotes a route creation unit which reads node link data 1b from the map data memory 1, searches for a route from the current position to the destination, and connects the two points by a link to provide a guidance route. Ask for. Reference numeral 6 denotes a guidance route memory which stores the guidance route obtained by the route creation unit 5. Reference numeral 7 denotes a map data forming unit which reads out the drawing data 1a from the map data memory 1 and writes image data corresponding to an arbitrary scale map centered on the current position read from the current position memory 3 into the V-RAM 8. At the same time, the map data forming unit 7 reads the guidance route data from the guidance route memory 6 and, if there is a guidance route on the road network on the currently displayed map, the V route is displayed so that the guidance route is displayed in red. -Update the image data in the RAM 8. V
-The RAM 8 stores image data for display on the display 9. The display 9 displays a map around the current position based on the image data in the V-RAM 8.

Reference numeral 10 denotes a destination arrival determination unit which, when a destination is set by a driver, selects a link closest to the destination from among individual links constituting a guidance route, and selects the link from the destination. A perpendicular is lowered to the link, and a value called a destination arrival determination distance GOIP is set according to the length of the perpendicular (hereinafter, referred to as a perpendicular distance DGO). Specifically, as shown in FIG. 2A, the destination arrival determination unit 10 determines the destination when the perpendicular distance DGO (the length of the perpendicular drawn from the destination 30 to the guidance route 20) is 100 m or less. The land arrival determination distance GOIP is set to 300 m. Similarly, the destination arrival determination unit 10 sets the destination arrival determination distance GOIP to 750 m when the perpendicular distance DGO is greater than 100 m and equal to or less than 700 m as shown in FIG.
Further, as shown in FIG.
If it is larger than 0 m, the destination arrival determination distance GOIP is set to the perpendicular distance DGO + 50 m. FIG. 3 is a graph showing the relationship between the perpendicular distance DGO and the destination arrival determination distance GOIP.

Further, the destination arrival determination unit 10 determines the distance between the current position and the destination (hereinafter, referred to as “the destination”) at regular intervals when the vehicle is traveling.
The remaining travel distance is calculated, and the remaining travel distance is compared with the destination arrival determination distance GOIP. When the remaining travel distance is equal to or less than the destination arrival determination distance GOIP, the destination arrival determination unit 10 determines that the vehicle has arrived at the destination,
A message notifying the driver is displayed on the display 9. Specifically, in each of FIGS. 2 (a) to 2 (c), the own vehicle moves to the destination determination distance GOIP.
When the vehicle reaches an intersection (hereinafter, referred to as a guidance end point 40) between a circle having a radius of and the guidance route 20, the destination arrival determination unit 1
0 determines that the vehicle has arrived at the destination.

Next, the operation of the navigation apparatus for a vehicle having the above configuration will be described with reference to FIG. When the driver turns on the car engine, the car navigation system is turned on, and at the same time, the contents of the V-RAM 8 are cleared by the map data forming unit 7. Since the stop position data when the vehicle was stopped last time is held in the current position memory 3 as the current position data, the vehicle navigation device uses the data in the current position memory 3 as the current position data at the time of engine start. It can be used as it is.

Next, the map data forming section 7 reads out the current position data from the current position memory 3, reads out the drawing data 1a from the map data memory 1, and converts the image data showing a map around the current position into a center. Write to V-RAM8. Thereby, the display 9 is connected to the V-RAM.
A peripheral map image is displayed on the basis of the image data written in 8. Next, when the driver sets destination data using the destination setting unit 4, the destination data is stored in the route creation unit 5.
And the destination arrival determination unit 10. When receiving the destination data, the route creating unit 5 reads the current position data from the current position memory 3 and then performs a route search based on the node link data 1b read from the map data memory 1 to determine the current position and the destination. Is created and stored in the guidance route memory 6.

The map data forming unit 7 refers to the current position memory 3 and the guidance route memory 6 at a fixed cycle, and the current position is always at a predetermined position on the display 9 and the guidance data of the road network around the current position is provided. The V-RA is set so that the road corresponding to the route is displayed in red on the display 9.
M8 is updated at regular intervals. Upon receiving the destination data, the destination arrival determination unit 10 draws a perpendicular from the destination indicated by the destination data to the link closest to the destination, and determines the length of the perpendicular (the perpendicular distance DGO). calculate. Further, the destination arrival determination unit 10 calculates the destination arrival determination distance G from the length of the perpendicular distance DGO according to the graph shown in FIG.
Ask for OIP.

Next, when the driver starts driving and the car starts running, each of the current position locating section 2, the map data forming section 7, and the destination arriving determining section 10 repeats the processing described below at regular intervals. The current position locating unit 2 calculates the current position data from the direction of the vehicle detected by the gyro sensor 2a and the speed of the vehicle detected by the vehicle speed detector 2b, and uses the GPS 2c to calculate the current position data. Is checked to see if it is an accurate value. When it is confirmed that the current position data is an accurate value, the current position locating unit 2 updates the value of the current position memory 3 to the current position. If the current position data does not match the reference value from the GPS 2c, the current position locating unit displays a warning message on the display 9 to notify the driver that an abnormality has occurred in the current position data.

The map data forming unit 7 refers to the current position memory 3 and the guidance route memory 6 at a fixed cycle, and the current position is always at a predetermined position on the display 9;
The V-RAM 8 is updated at regular intervals so that the guidance route is displayed in red on the display 9. The destination arrival determination unit 10 calculates the distance (remaining travel distance) between the current position and the destination, and compares the remaining travel distance with the destination arrival determination distance GOIP. If the remaining travel distance is equal to or less than the destination arrival determination distance GOIP, the destination arrival determination unit 10 determines that the vehicle has reached the destination, and displays a message indicating this on the display 9.

Next, a description will be given of the destination arrival determination processing of the automobile navigation apparatus according to the present invention, taking as an example a case where the own vehicle travels on the road network shown in FIG. It is assumed that the own vehicle is traveling at the point B on the guidance route 20 in the direction of the arrow. In order to reach the destination A, it is assumed that the vehicle has to turn left at the point C and enter a side path other than the search target route shown by the route CDA in FIG. A perpendicular foot (normal distance DGO) from the destination A to the guidance route is 1000
m, the destination arrival determination unit 10 sets the destination arrival determination distance GOIP to 1050 m from the graph shown in FIG.
Is calculated. In FIG. 4, if an arc having a radius of 1050 m is drawn around the destination A, the arc intersects the guidance route at the point E. Therefore, when the vehicle arrives at the point E, the destination arrival determination unit 10 displays “Route” on the display. The message "Guidance completed, 1050m to destination" is output. Thereafter, the driver searches for the route CDA while referring to a large-scale map or asking at a nearby police box, and reaches the destination A.

In the above-described road network, the conventional car navigation system guides the vehicle from the destination A to the point F (see FIG. 4) which is the foot of the perpendicular dropped down to the guidance route 20, and ends the route guidance. The car was on route C-F
Will go back and forth in vain. On the other hand, in the automobile navigation device according to the present invention, when the distance between the destination and the guidance route (the perpendicular distance DGO) is long, the guidance is terminated early according to the length of the perpendicular distance DGO. There is no useless driving of the vehicle.

The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and changes in design and the like can be made without departing from the gist of the present invention. Even if there is, it is included in the present invention. For example, in the above-described embodiment, the perpendicular distance DGO and the destination arrival determination distance GOIP have a relationship as shown in the graph of FIG. 3, but the relationship between these two values is not necessarily the same as the graph. It does not need to be the one shown in the above, and can be set freely.

[0025]

In the navigation apparatus for an automobile according to the present invention, the destination arrival determining means drops a perpendicular from the destination to the link closest to the destination among the links constituting the guidance route, and When the distance between the current location and the destination becomes equal to or less than a predetermined distance obtained from the length of the perpendicular, it is determined that the vehicle has arrived at the destination. Thereby, the distance for determining that the vehicle has arrived at the destination can be changed according to the distance between the destination and the guidance route. Therefore, when the perpendicular is short, it is determined that the destination is almost adjacent to the guidance route, and the vehicle is guided to a position close to the destination,
Conversely, if the perpendicular is long, it is determined that the destination is located far away from the guidance route, and the guidance is terminated early,
The driver can then select a subsequent traveling route. As a result, it is possible to prevent the driver from being guided to the vicinity of the destination and detoured.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an automobile navigation device according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a relationship between a perpendicular distance DGO and a destination arrival determination distance GOIP in the embodiment.

FIG. 3 is a graph showing a relationship between a perpendicular distance DGO and a destination arrival determination distance GOIP in the embodiment.

FIG. 4 is a schematic diagram showing a traveling route of an automobile equipped with an automobile navigation device in the embodiment.

[Explanation of symbols]

1 ... Map data memory 2 ... Current location unit
3 ... current position memory 4 ... destination setting section 5 ...
... route creation unit, 6 ... guidance route memory, 7 ... map data formation unit, 8 ... V-RAM, 9 ... display, 10 ... destination arrival determination unit

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-7-55488 (JP, A) JP-A-6-66576 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01C 21/00-21/36 G08G 1/0969 G09B 29/10

Claims (1)

(57) [Claims] 1. a current position detecting means for detecting a current position of a vehicle; a road network storing means for storing a road network comprising at least node information and link information; a destination setting means for setting a destination; A navigation device for searching for a guidance route from a current position to a destination based on the navigation device; and a guidance device for performing predetermined guidance along the searched guidance route. A perpendicular line is dropped from the destination with respect to the link closest to the destination among the links to be performed, and the distance between the current position of the vehicle and the destination is equal to or less than a predetermined distance obtained from the length of the perpendicular line. A vehicle navigation device comprising a destination arrival determining means for determining that the vehicle has arrived at a destination.