JP3232970B2 - 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 search for a route when the vehicle deviates from a road.

[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, it is necessary to search again for a route to the destination (preferably, a route via the original guide route).

Therefore, a route search device for performing such a re-search is also known, and is disclosed in, for example, JP-A-4-313018.

[0005]

Here, in the deviation of the route, in addition to the mere mistake of the route selection, a part other than the road, such as entering the service area of the highway or entering the parking lot of the supermarket, is included. There is also a case to enter. Then, a re-search from the current location other than the road to the original route may be instructed.

[0006] When the current location is not on a road as described above,
To perform a route search, a search start point must first be set on a road. Therefore, conventionally, a search was made for a road close to the current location, and a search start point was set on the obtained road,
The search for the route returning to the original guide route was performed again.

However, according to this method, there is a case where the guidance start point is set on a general road passing near the service area even though the vehicle is parked in the service area of the expressway. The vehicle cannot enter this general road, and a completely useless re-search is performed. Further, when a parking lot entered from a general road is near a toll road, a search start point may be set on a toll road that cannot be entered.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has been made in consideration of the above circumstances. In a route search at a point departed from a road, a vehicle route that can set a search start point so that an appropriate search can be performed. It is an object to provide a guidance device.

[0009]

SUMMARY OF THE INVENTION The present invention relates to a vehicle route guidance device for searching for a route from a departure place to a destination and guiding the obtained route, wherein a current location detection means for detecting a current location of the vehicle. Road departure determination means for comparing the current position with the map data to determine departure from the road, road type storage means for storing the type of the road that was traveling immediately before the road departure, and a search instruction at the time of departure from the road And a search start point setting means for setting a search start point on a road of the road type stored in the road type storage means based on the information.

As described above, according to the present invention, when a search is instructed at a point where the vehicle has left the road, the search start point is set on a road of the same type as the type of the road that traveled last. Therefore, in the service area of the highway, when searching for a return road to the main line, if a search is made from a nearby general road that can not enter, or if a re-search is instructed at the supermarket parking lot of the general road, It is possible to prevent a route search from being performed on a nearby highway.

[0011]

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 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 map data for the whole country, 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 position 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 location at any time based on the current location, displays it on the display, and displays the current location on the map. This display is the same as the conventional one. 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. Then, when this re-search switch is touched, the route is searched again. This re-search is a search for a route returning to the original guide route, and a node close to the destination is selected as a merging node in a predetermined small area including the current position, and the merging node is set as a temporary destination and a route search is performed. Is performed. Here, the case where the search is performed again by the touch switch input has been described, but the search may be automatically performed again based on a certain condition.

In this embodiment, the CPU 14 performs a map matching process using the work area 18, and stores information on the road obtained as a result of the map matching in the memory 16 at this time. The data stored in the memory 16 includes roads (links).
Is included.

That is, as shown in FIG. 2, it is determined whether or not the vehicle is traveling (S11). If the vehicle is traveling, the type of link (toll road / general road guidance target road / non-guidance of general road) The target road is stored (S12). On the other hand, if you are not driving, the absolute coordinates (latitude, longitude) of the point
And the type of road that was last traveled (toll road / general road). As a result, the type of the road on which the vehicle ran last before stopping is stored in the memory 16.

When the re-search switch is depressed at the time of departure from the route, a route search to the merging node is performed. At this time, a search start point is determined according to the flowchart shown in FIG.

First, it is determined whether or not map matching has been departed (S21). As described above, the map matching is a process of matching the current position with a road on the map by comparing the road on the map with the current position. It is.

Here, the map data also has information on very small roads such as alleys and private roads. And
Since there is a possibility that such a small road may pass, these small roads are also subjected to matching in the map matching process. On the other hand, such a small road does not pass in normal running. It is better not to pass. Therefore, guidance target roads targeted for route search are limited to roads of a certain level or higher (national roads, prefectural roads, roads with a width of 5.5 m or more, etc.). Therefore, the number of roads subject to guidance is smaller than the roads targeted for map matching.

If NO in S21, that is, if map matching has been performed, it is determined whether or not the traveling road is a guide target road (S22). If the road is a guide target road, a route search (I) with the current location as a departure node is performed (S23).

(I) As shown in FIG. 4, the current location is set as the departure node, and the traveling direction is set only in the traveling direction, and a re-search is performed up to the junction node. However, if the link in the traveling direction is interrupted due to a dead end, it is permitted to pass in the opposite direction.

If NO in S22, that is, if the vehicle is not on the guide target road, the guide target road is detected, and a route search (II) in which a search start point is set on the preceding guide target road is performed (II). S24).

(II) As shown in FIG. 5, a rectangular area having a length of L1 km and a width of L2 km is set with the current position as the center of the bottom, and a guide target road is searched for. However,
Highways, urban expressways, and toll road main lines are excluded. Also exclude links that cannot be entered structurally, such as overpasses and underground. In this way, a line segment is drawn from the candidate guidance target road to a point on the link closest to the current location, and this is treated as a vector. Then, as shown in the figure, the end point of the shortest vector among all vectors within a range of ± 60 ° with respect to the traveling direction is set as a starting node.

In this way, the search start point is set on the guidance target road existing in front of the small road currently running, and the search is performed again. Note that L1 is 500 m or more, and L2 is 1 km or more.

When the departure node cannot be determined by this processing, the departure node is determined in the processing of (III) described later.

Next, in S21, if YES, that is, if the vehicle does not exist on the road, it is determined whether or not the last road type stored as described above is a toll road (S25). . If the road is not a toll road, a route search (III) in which a search start point is set on the guidance target road excluding the toll road is performed (S26).

(III) As shown in FIG. 6, a search for a guide target road is performed within a range of Lkm square around the current position. At this time, highways, city expressways, and toll road main lines are excluded from the target. Also, links where vehicles cannot enter the links at any time due to their structure, such as overpasses and undergrounds, are excluded. In the above (II), the traveling direction of the vehicle is considered because the vehicle is on the road, but in this case, the traveling direction of the vehicle is not considered because there is no vehicle on the road.

A line segment is drawn from the candidate guide target road to a point on the link closest to the current location, and this is treated as a vector. Then, the shortest vector among the obtained vectors is set as a starting node. In addition, L is set to 5 km or more.

Under the above conditions, if the departure node cannot be selected, it is determined that the departure node acquisition has failed, and the re-search to the requested joining node is not performed.

Next, in S25, if the road is a toll road, a route search (IV) in which a search start point is set on the toll road is performed (S27).

(IV) As shown in FIG. 7, a search is made for a guide target road only for the main roads of expressways, city expressways, and toll roads within a range of Lkm square around the current position. A line segment is drawn from the candidate guidance target road to a point on the link closest to the current location, and this is treated as a vector. Then, the shortest vector among these vectors is set as a starting node.

In this case, L is also set to 5 km or more.
Also, when the starting node cannot be selected under these conditions,
Processed as acquisition failure of departure node.

As described above, in the present embodiment, when a re-search is instructed at a point where the vehicle has left the road, the search start point is set on a road of the same type as the type of the road that traveled last. Therefore, in the service area of the highway, when searching for a return road to the main line, if a search is made from a nearby general road that can not enter, or if a re-search is instructed at the supermarket parking lot of the general road, It is possible to prevent a route search from being performed on a nearby highway.

In this embodiment, the processing at the time of re-search has been described. However, depending on the system, even at the time of the first route search, the current position may be incorrectly recognized and the wrong route search may be performed. . Therefore, by applying the present invention, the search start point can be set to an appropriate point.

[Brief description of the drawings]

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

FIG. 2 is a flowchart illustrating a process of storing a road type;

FIG. 3 is a flowchart illustrating a process of determining a search start point in consideration of a road type;

FIG. 4 is a diagram illustrating a search start point when the vehicle is located on a guidance target road.

FIG. 5 is a diagram illustrating a search for a search start point when the vehicle is located on a road that is not a guidance target road.

FIG. 6 is a diagram showing a search for a search start point when the current location is not on a road and the final traveling road is a general road.

FIG. 7 is a diagram showing a search for a search start point when the current location is not on a road and the last traveling road is a toll road.

[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.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G01C 21/00 G08G 1/0969 G09B 29/10

Claims (1)

(57) [Claims] 1. Search for a route from a departure point to a destination,
A vehicle route guidance device that guides the obtained route, comprising: a current position detection unit that detects a current position of the vehicle; a road departure determination unit that compares the current position with map data to determine a departure from a road; Road type storage means for storing the type of the road that was traveling immediately before leaving, and a search start for setting a search start point on a road of the road type stored in the road type storage means based on a search instruction at the time of leaving the road. A vehicle route guidance device, comprising: point setting means.