JP3301282B2 - Vehicle route guidance device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle route guidance apparatus for guiding a route from a departure place to a destination, and more particularly to a route re-search.

[0002]

2. Description of the Related Art Conventionally, a route guidance device (navigation device) for searching for a route from a departure point to a destination and displaying the route on a map and constantly displaying the current location while the vehicle is running to provide route guidance is known. Have been.

[0003] The route guide device guides the vehicle so that the vehicle can travel along the set route. However, the route guide device may accidentally deviate from the route or deviate from the route set by the driver. In such a case, if there is no change in the destination, the route to the destination needs to be searched again. In this case, it is easy for the driver to return to the originally set guide route (original route) and continue driving, and the time required for the re-search is reduced because the area required for the re-search is small. There are also benefits. Therefore,
A route search device that performs such a re-search is also known.

Here, when performing a route search, it is necessary to set a destination for re-searching different from the initially set destination. Therefore, in the case of this re-search, the route search is performed using the point on the original route closest to the current location as the temporary destination. As a result, the vehicle can return to the original route with the shortest route, and can continue traveling to the destination as originally planned.

[0005]

However, in the conventional return route, a large-scale route is sometimes selected. That is, as shown in FIG. 10, it is assumed that the current position is out of the guidance route, and a re-search is performed at this time. In this case, a route a toward the node A on the original route is obtained as the shortest route to the original route as a search result.

However, since the original route is curved,
In practice, it is preferable to select the route b that goes straight from the current location to the node B on the original route as the route to the destination. Therefore, even in such a case, a device that can search for an optimal route is desired.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has as its object to provide a route search device capable of obtaining an optimum route by re-searching.

An apparatus for re-searching a route is described in Japanese Patent Application Laid-Open No. 4-313018.

[0009]

The present invention SUMMARY OF THE INVENTION comprises a new route searching means for searching a new route to a predetermined point closest to the destination in the small area set even on draft path as temporary destination , Is provided.

As described above, since the re-search is performed in the small area, the time required for the re-search may be short. The temporary destination is an intersection closest to the destination in the small area. Therefore, the temporary destination can be easily detected, and a route that returns to the original guide route in a direction approaching the destination is searched, and the probability of searching for a large-scale route is reduced.

Further, the present invention has a departure judging means for judging a departure from the relationship between the current position and the guide route, and when the departure from the route, the new route searching means returns to the original guide route originally set. It is characterized by searching for a route.

That is, the re-search instruction is often issued when the vehicle goes off the route. In this case, it is possible to effectively search for a route that returns to the original guidance route in a direction approaching the destination.

Further, the present invention is characterized in that when the guide route is a toll road, the small area is expanded to the destination side so as to include the entrance on the destination side.

In the case of a toll road, the number of intersections is smaller than that of a general road because there are few entrances. By expanding the small area to the destination side, the probability of being able to be guided to the entrance on the destination side can be increased.

Further, the present invention is characterized in that the small area is an area including the current position and having a wide destination side.
Since a small area is set in consideration of the current location, an intersection close to the destination can be reliably detected, and this can be set as a temporary destination.

Further, the present invention is characterized in that the small area is an area including a current position and a wide traveling direction side of the vehicle. Since the traveling direction is taken into consideration, the temporary destination is determined according to the traveling direction, and the route can be selected according to the traveling direction at that time.

Further, according to the present invention, the small area is preliminarily divided on a map, and adjacent small areas are set so as to partially overlap each other. And selecting a small area on the destination side.

Since the small areas are set in advance, the map reading of the small areas can be easily performed, and the frequency of the reading is reduced. Furthermore, since there is an overlapping portion, an area for the overlapping portion always exists on the destination side of the current location, and it is possible to reliably search for a temporary destination on the destination side.

[0019]

[0020]

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the device according to the present embodiment, which comprises an ECU 100 for performing various processes and an external ROM 200 for storing map data and the like. Actually, there are various devices such as a display for displaying a route and the like on a map, a switch for performing various inputs (including a touch switch using the display), and a voice output means for providing voice guidance for the route. However, the description is omitted here.

The ECU 100 includes therein a sensor processing unit 12, a CPU 14, a memory 16, a work area 18,
It has a communication IC 20 and a buffer 22.

The sensor processing unit 12 receives GPS (global positioning system) data as current position information, a vehicle speed pulse SPD for vehicle speed, and a gyro output as azimuth information for vehicle traveling direction.
This is supplied to the CPU 14 as predetermined digital data. The memory 16 stores various state data for the CPU 14 to perform desired processing, such as state data for performing a route search. The work area 18 includes the CPU 1
Reference numeral 4 denotes an area for temporarily storing data and performing calculations when performing various processes. The communication IC 20 includes a CPU 14
A predetermined communication is performed with the external ROM 200 in response to an instruction from the external ROM 200, and predetermined map data is read from the external ROM 200. The data read from the external ROM 200 is temporarily stored in the buffer 22, and the CPU 14 uses the data in the buffer 22 when necessary.

The external ROM 200 is provided with a plurality of CD-ROMs containing nationwide map data, and the map data from the designated CD-ROM is transmitted to the communication I / O.
It is read out by communication with C20.

Here, the current location of the vehicle can be known from the GPS data. However, the GPS data receives radio waves from artificial satellites. In a situation where radio waves cannot be sufficiently received (in an urban area, inside a tunnel, or the like), the current position of the vehicle is accurate. Current location cannot be detected. Therefore, the CPU 14 detects which direction and how far the vehicle has traveled from the vehicle speed and the gyro output, and keeps track of the current position.

Further, the current position data obtained in this way has some errors. On the other hand, since the vehicle normally travels on a road, the current position can be corrected by collation with the map data. For example, when the vehicle turns right at an intersection, it can be recognized from the movement of the vehicle that the current position is an intersection, and the current position can be corrected. Therefore, in the detection of the current location, such correction by map matching is also performed.

When the destination is set by inputting predetermined information (input of a name, a place name, an address, etc. specifying the destination) and a route search is instructed, the ECU 100 makes a search from the current position to the destination. Perform a route search. This route search is performed by an optimization plan of a desired algorithm such as the Dijkstra method. For this purpose, the CPU 14 reads necessary map data from the external ROM 200 and
Work area 18 based on the state data stored in
To search for the optimal route. Then, the obtained optimum route is stored in a predetermined area of the memory 16.

When the vehicle starts traveling along the route, the CPU 14 reads out the map data including the current position at any time based on the current position, displays it on the display, and displays the current position on the map. This display is the same as the conventional example shown in FIG. In addition, the route to the set destination is displayed in a color that can be distinguished from other roads so as to be easily understood.

If the vehicle deviates from the route during traveling along such a route, the apparatus recognizes this from the difference between the route and the current location. In the case of a deviation from this route, a re-search switch is displayed on a display functioning as a touch switch. When the re-search switch is touched, a re-search is performed. Further, an automatic mode for automatically performing a re-search under a predetermined condition (for example, when the vehicle has traveled a predetermined distance after the route departure or when a predetermined time has elapsed after the route departure) may be set.

Then, in the present embodiment, in this re-search, a search is performed using the confluence node in the small area as a temporary destination. Here, the small area is, for example, an area of 5 km square or more around the current location, and the merge node is a node closest to the destination in the small area. Nodes are mainly used in route search.
It is an intersection where the roads of the predetermined rank or more (national roads, prefectural roads, widths of 5.5 m or more, etc.) intersect, and this node divides the road and connects straight lines (generally, roads ) Is called a link, and this aggregate of nodes and links is called a route network. A route search is performed using this route network.

For example, in the example of FIG. 2, an area of D'.times.D is set as a small area with the current position substantially at the center, and a node in this small area which is closest to the destination is determined as a merge node.

The detection of the merging node may be performed when the re-search is performed, but the shorter the time from when the re-search switch is pressed until the result of the re-search is displayed, the better.
Therefore, in the present embodiment, the merging node is detected at the time of updating the small area. In addition, the small area may be constantly updated as an area of a predetermined size centering on the current location. However, in this case, the number of times of reading the data becomes too large, and thus the small area of the predetermined size is displayed on the map data. Is set in advance, a small area is determined according to the current location,
The calculation is performed only when the small area where the current location is located changes. In the present embodiment, the small areas are determined to some extent based on administrative divisions such as "... City".

The detection of the merging node will be described with reference to FIG. First, map data of a small area is read (S11). Next, nodes on the route are recognized in the read map data, and a node (merging node) closest to the destination is searched for (S12). Then, it is determined whether or not the merging node exists (S13). If the merging node exists, the node number is stored (S1).
4). On the other hand, if there is no merging node in S13, a flag indicating no node is set (S1).
5). Then, it is determined whether or not the small area to which the current location belongs has changed (S16).
Then, a search for a merging node for the next small area is performed.

In this way, the device detects the joining node when updating the small area. In particular, in the present embodiment,
This merge node is also detected when the vehicle is traveling on the route. Then, since the re-search switch is always displayed on the screen displaying the current position, by touching the re-search switch, a route search with the junction as a temporary destination is performed. Here, in this re-search, a route search is performed by making it difficult to pass the next link on the route side on the destination side. Therefore, the detour route is automatically searched, and the detour route can be searched by a simple operation at the time of traffic congestion, accident, closing of traffic, and the like.

Next, the re-search performed when the re-search switch is pressed will be described with reference to FIG. When the re-search switch is pressed, first, it is determined whether or not there is a merge node in the small area based on whether a flag indicating that there is no merge node is set (S21). If there is a confluence node in the small area, a search in which the confluence node is set as a destination is started in the small area (S22). Then, at this time, a switch for "all route search" is displayed on the display (S23), and it is determined whether the "all route search" switch is pressed (S24).

If the "all route search" switch is not pressed, it is determined whether the small area search has been completed (S2).
5) If not finished, return to S24. Unless the "search all routes" switch is pressed, this loop is repeated until the end of the small area search. When the small area search ends, it is determined whether or not the calculation has failed (S26). Based on the result of the small area search, a route return to the original route is started via the junction node to start route guidance to the destination (S27).

On the other hand, if there is no merging node in S21, and if the "search for all routes" switch is pressed in S24, an entire route search from the current position to the destination is performed (S28). A guide to the destination is provided based on the information (S29).

In this way, when the re-search switch is pressed, the re-search is performed up to the merge node in the small area. Since the search is for a small area, the search is completed in a relatively short time with a small amount of target data. Therefore, the time from when the re-search switch is pressed until the route is displayed is short. When the re-search switch is pressed, it is often desired to know the direction to proceed at that time, and it is preferable that the search be completed in such a short time. Also, as mentioned above,
The merging node has been aware before the re-search switch is pressed, and the search time is shortened even from this point.

"If the Toll Road is a Route" If the guidance route is a toll road, the merging node becomes the entrance of the toll road. A regular road has a considerable number of nodes, while a toll road has a very small number of nodes. Therefore, in a normal small area, there is a high probability that there is no merging node in that area, or even if there is, only nodes that are far from the destination are present. Therefore, in the present embodiment, if the toll road is a guidance route, the small area is expanded in the direction of the destination. Here, adjacent small areas are set so as to overlap as shown in FIG.

That is, as shown in FIG. 5, the small area is enlarged in the direction of the destination. This can be achieved by increasing the amount of map data to be taken in the following conditions when the map data is taken in S11 of the flowchart in FIG.

Condition) The guide route is a toll road, and the link of the guide route in the overlap between the small area where the current location is located and the small area on the destination side is a toll road, and there is an adjacent small area including the link. In the case where the entrance of the toll road does not exist even if the area is enlarged, the small area may be further enlarged.

As a result, the small area is expanded, the probability of the existence of the entrance of the toll road increases, and the merging node can be made closer to the destination. The expansion of the small area may be performed by any method, and the adjacent area may be entirely taken in, or may be cut off to some extent (for example, about 1.5 times expansion).

"Small Area Setting 1" In the above-described embodiment, a small area based on the administrative division is included in the map data. However, in the case of holding such a small area, the area in front of the current location often becomes small. Therefore, it is preferable to set adjacent small areas so as to partially overlap each other. That is, as shown in FIG. 6, overlapping areas are provided at the boundaries between the small areas. And
If the current location is in the overlapping area, a small area on the destination side is selected. As a result, at least the overlapping area exists on the destination side from the current location, and the probability that the joining node will be on the destination side increases.

"Small area setting 2" Further, the small area may be set according to the current location. That is, FIG.
As shown in the figure, a predetermined range (for example, 10 km square) from the current location to the destination may be set as a small area. Thus, the small area can be set closer to the destination than the current location.

The small area may be set in consideration of the traveling direction of the vehicle. That is, as shown in FIG. 8, a predetermined range on the traveling direction side from the current position may be set as the small area. Thereby, a suitable small area setting can be performed in consideration of the current traveling direction.

In the case of setting such a small area considering the current position, map data must be acquired based on the current position. For this reason, the map data to be taken must be changed during traveling. Therefore, it is preferable to take in the next small area only when the current location reaches the center of the small area.

[Setting of Temporary Destination Based on Distance from Departure Point] Further, a temporary destination node may be set based on the distance from the departure point without setting a small area. That is, as shown in FIG. 9, data on the point at which the vehicle departed from the guide route is stored, and the traveling distance L after the departure is counted. When the re-search switch is pressed, 2L from the departure point is pressed. A node on the destination side by an appropriate distance larger than L is set as a temporary destination. Note that a node does not always exist at the location of 2L.
It may be a nearby node or a nearest node beyond 2L.

According to this method, the setting of the temporary destination is very easy, and the setting of the temporary destination close to the destination can be surely performed.

Further, a circle centering on the current position is set,
This is sequentially expanded, and after this circle touches the route, the radius of the circle is further expanded by a predetermined distance (for example, 5 km), and a node in the circle closest to the destination on the route may be set as the temporary destination. . Even with this method, a temporary destination close to the destination can be easily set.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an embodiment.

FIG. 2 is a diagram illustrating a merging node;

FIG. 3 is a flowchart for explaining the operation of merging node detection;

FIG. 4 is a flowchart illustrating a re-search operation.

FIG. 5 is a diagram showing setting of a small area in consideration of a toll road.

FIG. 6 is a diagram illustrating setting of a small area having an overlapping area.

FIG. 7 is a diagram illustrating setting of a small area in consideration of a current position and a destination.

FIG. 8 is a diagram showing setting of a small area in consideration of a current location and a current traveling direction.

FIG. 9 is a diagram illustrating setting of a temporary destination based on a distance from a leaving point.

FIG. 10 is a diagram showing a route by a conventional re-search.

[Explanation of symbols]

12 sensor processing unit, 14 CPU, 16 memory, 1
8 work areas, 20 communication ICs, 22 buffers,
100 ECU, 200 external ROM.

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G01C 21/00 G08G 1/0969 G09B 29/00-29/10

Claims (8)

(57) [Claims] 1. A vehicle route guidance device for guiding a route from a departure place to a destination, comprising: a current location detection means for detecting a current location of the vehicle; and a route search for searching for a new route from the current location to a guidance route. Means, setting means for setting a small area in consideration of the current location, and a new route for searching for a new route using a predetermined point on the guide route and closest to the destination in the set small area as a temporary destination A route guidance device for a vehicle, comprising: a search unit. 2. A vehicle route guidance device for guiding a route from a departure point to a destination, comprising: a current position detection means for detecting a current position of the vehicle; and a command for searching for a new route from the current position to the guidance route. Re-search instructing means; small area setting means for setting a re-search small area of a predetermined size based on the current location based on the re-search instruction; And a new route searching means for searching for a new route using a predetermined point near the destination as a temporary destination. 3. The apparatus according to claim 1, further comprising: a departure determination unit that determines a departure from the relationship between the current location and the guide route, wherein the new route search unit is originally set at the time of departure from the route. A route guidance device for a vehicle, which searches for a return route to the original guidance route. 4. The apparatus according to claim 1, wherein, when the guide route is a toll road, the small area is enlarged to include the entrance on the destination side. A route guidance device for a vehicle, comprising: 5. The vehicle route guidance device according to claim 1, wherein the small area is an area including a current location and having a wide destination side. 6. The vehicle route guidance device according to claim 1, wherein the small area includes a current location, and the traveling direction side of the vehicle is a wide area. . 7. The device according to claim 1, wherein the small area is pre-divided on a map,
The adjacent small areas are partially overlapped and set,
A route guidance device for a vehicle, wherein a small area on the destination side is selected when the current location is located in an overlapping portion. 8. A vehicle route guidance device for guiding a route from a departure point to a destination, comprising: a current position detection means for detecting a current position of the vehicle; and a route search for searching for a new route from the current position to a guidance route. Means, setting means for setting a small area for a search in consideration of the current location, and searching for a new route with a predetermined point closest to the destination in the set small area on the guide route as a temporary destination And a new route searching means, wherein the small area is an area that is changed by moving the current location.