JP3196648B2 - 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.

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]

However, in the above conventional example, when re-searching is performed, a route toward the destination with the current location at that time as a departure point, for example, a return route that returns to the original guide route is searched. .

[0006] Here, if the user accidentally leaves the route and conducts a re-search, the route obtained by the search is likely to increase in the reverse direction, and a route that turns right or left immediately from the current location may be selected. Is big. On the other hand, it is often the case that the driver instructs a re-search for a wrong route. Therefore, there is a case where it is impossible to make a sharp turn right or left, or the searched route has already passed the intersection where the turn is instructed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and provides a vehicle route guidance apparatus capable of effectively searching for a selectable road when performing a re-search. The purpose is to do.

[0008]

SUMMARY 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 a re-search for re-searching a route from a current location to a destination.
Means, and the re-search means includes a vehicle speed and a re-search
Based on the time required for the search,
Prohibit right and left turns and re-search for the route.
Is not zero when the vehicle speed is zero
A predetermined distance, wherein the predetermined distance is changed according to the number of lanes .

As described above, according to the present invention, a right or left turn at an intersection near the current position is prohibited, and a route search is performed.
Therefore, it is possible to prevent selection of a route that makes a right or left turn at an intersection that has gone too far or at an intersection that is too close to make a right or left turn. Further, since the determination as to whether or not it is difficult to make a right or left turn is based on the vehicle speed at that time, an appropriate route can be searched regardless of the vehicle speed at that time.

Further, according to the present invention, a left-right turn is performed from a re-search start point.
The specified distance to prohibit is necessary for the current vehicle speed and re-search
The predetermined distance is determined based on an appropriate time and is a non-zero predetermined distance when the vehicle speed is zero.

Therefore, it is possible to prevent the user from being instructed to make an excessive right or left turn even while the vehicle is stopped.

[0012] Then, the present invention is characterized in that to change in accordance with the right left turn length for the zero vehicle speed to the number of lanes.

Therefore, a sufficient preparation period can be maintained even if the number of lanes is large.

[0014] The present invention also relates to a method for moving from a departure point to a destination.
A route guidance device for a vehicle that guides a route,
Has a re-search means for searching again for a route from
And the re-searching means is a predetermined distance from the re-search starting point to the right.
When re-searching while prohibiting left turn and re-searching the route
In addition, the predetermined distance longer than the predetermined distance for prohibiting the right or left turn
A continuous travel distance is set, and within this continuous travel distance, it is determined whether or not a branch point exists farther than the predetermined distance prohibiting the right / left turn. It is characterized in that the prohibition of the right or left turn at the predetermined distance is released and the route is searched again.

In this way, if the next branch point is far away after the nearby branch point, a route using the branch point can be obtained near the branch point, thereby preventing the setting of a large-scale route. it can. In particular, when the vehicle travels on a route such as a mountain road where there are few turning points that can make a right or left turn, it is possible to effectively prevent a large turn due to prohibition of a right or left turn.

[0016]

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. Map data from the designated CD-ROM is transmitted to the communication I / O.
It is read out by communication with C20. However, external R
The OM is not limited to a CD-ROM changer.

Here, the current position of the vehicle can be known from the GPS data. However, the GPS data receives radio waves from artificial satellites, and in a situation where radio waves cannot be sufficiently received (in an urban area, in a tunnel, or the like), accurate information is obtained. 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. for 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, in this re-search, a route search is performed by prohibiting a right or left turn at a node within a predetermined distance from the current position. That is, as schematically shown in FIG. 2, the links (a to z, A to W) are arranged,
It is assumed that the vehicle is traveling with the link o facing upward. Although some links have vertical divisions in the vertical direction of the road, the link to be selected for the route search is usually one direction, and therefore, is shown as one link per section in the figure.

In this state, it is assumed that the re-search switch is pressed and the re-search is performed, and it is assumed that the node indicated by α in the figure is set as a temporary destination. As a result, the search start node (starting point) is set to β, and if no special consideration is given, the links t, p, and g should be selected as the route to the temporary destination α.
However, the vehicle is traveling on the link o, and it is often difficult to make a right turn to the link t immediately ahead.

Therefore, in the present embodiment, the right and left turn prohibition length L is set according to the following equation, and right and left turns in this section are prohibited, thereby avoiding the above-mentioned problem.

L = V × T + L0 Here, L is a left / right turn prohibition length, V is a vehicle speed, T is a search time required for a route search, and L0 is a right / left turn prohibition length when the vehicle is stopped.
Here, T may be variable based on the size of the search area or the amount of data to be searched that changes depending on the density of the road.

If the right-left turn prohibition length L is the length shown in the figure, right-left turns at the first and second nodes from the current location are prohibited. Therefore, the links o,
A route through x, G, L, H, y, p, g should be set.

In particular, the right-left turn prohibition length L is calculated by the vehicle speed V × the search time T to calculate the distance traveled until a search result is obtained. Therefore, it is possible to prevent an intersection that should be turned right or left when the search result is output. In addition, since the left / right turn prohibition length L0 when the vehicle is stopped is set, it is possible to prevent the selection of a path that makes an unreasonable right / left turn even when the vehicle is stopped.

Here, the left / right turn prohibition length L0 when the vehicle is stopped
Is preferably changed according to the number of lanes of the road on which the vehicle is traveling. In other words, while driving in the left lane of a three-lane road, a certain distance is required to make a right turn. The length L0 should be set large.

FIG. 3 is a flowchart of a process for changing the stop right / left turn prohibition length L0 according to the number of lanes. First,
It is determined whether the lane of the current road (link) is one lane (S11). If it is one lane, L0
Is a one-lane distance L1 (e.g., 5
0m) (S12). If it is not one lane in S11, it is determined whether or not it is two lanes (S13). If the vehicle has two lanes, L0 is set to a distance L2 (for example, 100 m) larger than L1 (S1).
4). If it is not two lanes in S12, it is determined whether or not it is three lanes (S15). In the case of three lanes, L0 is a distance L3 (for example, 200 m) larger than L2.
(S16). If it is not three lanes in S15, it is four lanes or more, and L0 is set to a distance L4 (for example, 300 m) larger than L3 (S17).

In this way, the left / right turn prohibition length L0 when the vehicle is stopped can be changed according to the lane. Therefore, a sufficient preparation period for turning right and left can be provided according to the number of lanes.

Next, the operation of the processing for prohibiting such a right or left turn within the distance L will be described with reference to FIG.

First, the vehicle speed V, the search time T, and the right / left turn prohibition length L0 when the vehicle is stopped are taken in, and the right / left turn prohibition length L is calculated (S21). Next, based on the right-left turn prohibition length L, a link that should not make a right turn or left turn and enter should be obtained (S22). Since this example is based on FIG. 2, o, s, t, B, and C are detected as links that should not enter. Here, the link o is the link of the present location, which is set as prohibiting the back.

Then, a search is performed by setting the calculated cost of the entry-prohibited link to a large value close to infinity (S23). Here, the cost is a value of the non-aptitude (distance, required time, and the like) assigned to each link in the optimal plan for the route search. Therefore, if the cost is set to a large value close to infinity, the route through this link is
Since the cost becomes a large value close to infinity and becomes an inappropriate route compared to other routes, the route is not selected. For this reason, in this embodiment, the passage of this link is automatically excluded by assigning a large value close to infinity as a cost value to a link that is prohibited from entering.

Then, a search is performed under these conditions, and it is determined whether the search has been successful (S24). Here, a successful search means that all links are connected between the current location and the destination (passing point), and the total link length is a fixed value times the linear distance L between the current location and the destination (passing point). It is within. If the search is not successful in S24, the costs of the relatively distant links B and C are returned to the original values, and the search is performed (S25). Then, it is determined whether the search was successful (S26). If the search is not successful in S26, the cost of the next distant link s, t is returned to the original value, and the search is performed (S27). Then, it is determined whether the search was successful (S28). If the search is not successful in S28, the cost of the back link o is returned to the original value, and the search is performed (S29).

When the search is successful in S24, S26 and S28 and when the search is performed in S29, the route guidance may be performed using the search result, and the process is terminated. It should be noted that gradually releasing the entry ban in this way is
This is to make a right or left turn on the destination direction side of the left / right turn prohibition section L even a little, and if the costs of B, C, s, t, o are removed from 一度 at once, it may pass through o which is the most inappropriate. This is because it is considered that the number will increase.

As described above, according to the present embodiment, right and left turns at a node having a predetermined right / left turn prohibition length are prohibited, and
Perform a route search. Therefore, it is possible to prevent selection of a route that presupposes a right or left turn at an intersection that has gone too far or at an intersection that is too close to make a right or left turn. In addition, since it is determined whether or not it is difficult to make a right or left turn based on the vehicle speed at that time, an appropriate route can be searched regardless of the vehicle speed. Furthermore, even if the vehicle speed is 0, a predetermined distance according to the number of lanes is set as the right / left turn prohibition length. Occurrence can be prevented.

Next, the re-search operation in consideration of the continuation possible distance from the current position will be described with reference to FIG.
First, it is determined whether the re-search switch has been operated (S3).
1) In the case of NO, returning to the determination of S31 again detects that the re-search switch has been operated.
When the re-search switch is operated, the continuously travelable distance LT is fetched, and it is determined whether or not there is a branch point (node) that can branch from the current position to the distance LT (S3).
2). The distance LT is a distance determined according to the type of the road, the vehicle speed, and the like, and is obtained from a table stored in advance. This table will be described later. The distance LT is determined so as to satisfy L (= V × T + A) ≦ LT.

If there is a branchable node within the distance LT, the left / right turn prohibition length (straight ahead priority distance) is set to L.
= V × T + A (S33). Here, V is the vehicle speed, and T is the time required for the search, which is the same as the equation for calculating the left / right turn prohibition length L described above. On the other hand, the distance A is the minimum distance for prohibiting right and left turns determined according to the vehicle speed, the type of road, and the like, that is, the minimum value of the right and left turn prohibition length L. Slightly different. This is because it is considered better to make this distance A different depending on the speed, the type of road, and the like. In the above-described embodiment, it is also preferable to use this A instead of L0. The distance A will be described later. On the other hand, if there is no branchable node within the distance LT, the process of S38 described later is performed.

In S33, if the right-left turn prohibition length L has been set, the first branch is searched between L and LT (S35). Then, according to the result of the search, it is determined whether or not there is a branch between the distances L to LT (S36).

When there is a branch between the distances L to LT, a route search from the current position to the destination is performed as shown in FIG. 4 using the branch node between L and LT as the first branch. (S37). Therefore, a right or left turn within the right / left turn prohibition length L is prohibited, and a route search to the destination can be performed. On the other hand, S3
6, if NO, L = 0, LT = 0
The route search from the current position to the destination is performed as usual (S38).

As described above, if the route search in S37 or S38 has been performed, it is detected whether the route search has been completed (S39). If the route search has been completed, it is determined whether the route search has been successful (S40). ). If the search is successful, route guidance is started in accordance with the search result (S41). If the search is unsuccessful, processing such as display of search failure and a request for selection of the next process are performed (S42). .

As described above, in this embodiment, the distances L to L
If there is no branch between T, the guard of the left / right turn prohibition length L is removed, and a route search to the destination is performed. Therefore, a branch point very close to the current location is also targeted. This makes it possible to prevent an extremely long turn, such as when traveling on a mountain road and there is no long-distance branching point, and the route becomes extremely large. You can search.

That is, as shown in FIG. 6, four branches b, c, d, and e exist at the end of the current position, and the branches c and d exist between the distances L to LT. If
The search is performed with the branches c and d as the first branches. Therefore, it is possible to prohibit unreasonable right and left turns and perform an effective route search.

On the other hand, as shown in FIG. 7, when there is no branch between the distances L to LT, the search is performed ignoring the values of the distances L and LT. Therefore, all of the branches b, c, d, and e are to be searched. This, as described above,
It is possible to prevent a large-scale route from being set.

Next, FIG. 8 shows a setting table of the distance A used for setting the right and left turn prohibition length L and the continuous running distance LT.

First, as a condition, the type of the road where the vehicle is located is classified into a general road and a toll road. this is,
This is because toll roads can generally run at higher speeds.
Then, the road is classified based on whether the number of lanes on the road where the vehicle is located is one lane or two or more lanes. Next, the vehicle speed is classified into 8 km / h or more. Thus, there are eight cases. Then, distances A and LT are set according to each of the divisions.

As shown in the figure, the distance A is 100 m for a general road, one lane, 8 km / h or less, and 30 m for 8 km / h or more.
0 m, general road, 2 lanes or more, 300 km for 8 km / h or less
m, 500km above 8km / h, toll road, 1 lane, 8
100 m below km / h, 500 m above 8 km / h,
300m for toll road, 2 lanes or more, 8km / h or less, 8
It is set to 700 m above km / h. Therefore, the higher the vehicle speed and the greater the number of lanes, the greater the distance A on the toll road.
Becomes larger. Further, the distance LT is 1500 m when there are two or more lanes of a toll road, a toll road, one lane, 8 km /
h or over general roads, 2 lanes or more, 1 at 8 km / h or more
It is set to 200 m, and 1000 m in other cases.
This is often possible on toll roads at high speeds,
This is because it is considered that the driver does not care about the distance of about 1000 m even if the vehicle continues to run.

As described above, in this embodiment, the distances A and L
Since T is changed depending on the driving environment, a very effective re-search can be performed.

It is also preferable to change the distance LT depending on the vehicle speed. Further, in the above-described example, the determination of branchable nodes S32 and the like are provided. When no such node exists, the prohibition of right / left turn of the distance L may be canceled and the search may be performed.

[Brief description of the drawings]

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

FIG. 2 is an explanatory diagram showing right / left turn prohibition nodes;

FIG. 3 is a flowchart illustrating an operation of changing a left / right turn prohibition length according to the number of lanes.

FIG. 4 is a flowchart of a route search by setting a right / left turn prohibition length.

FIG. 5 is a flowchart of a route search including release of right / left turn prohibition.

FIG. 6 is an explanatory diagram when there is a branch between distances L to LT.

FIG. 7 is an explanatory diagram in a case where there is no branch between distances L to LT.

FIG. 8 is a diagram illustrating setting of distances A and LT.

[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 front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01C 21/00 G08G 1/0969

Claims (4)

(57) [Claims] 1. A vehicle route guidance device for guiding a route from a departure place to a destination, wherein the re-search means re-searches a route from the current location to the destination.
Has, the re-search means, based on the time required for the vehicle speed and the re-search at that time, together with the re-searches for a route prohibits the right or left turn at a predetermined distance from the re-search starting point, turning right or left based on the vehicle speed The prohibited length is zero when the vehicle speed is zero.
B) is a predetermined distance that is not
A route guidance device for a vehicle, wherein the route guidance device is changed in the same manner. 2. Guiding a route from a departure point to a destination
A route guidance device for a vehicle, wherein a re-searcher searches again for a route from a current location to a destination.
A step, wherein the re-searching means turns right or left a predetermined distance from the re-search starting point.
As well as re-search a route to prohibit, when re-search, length than the predetermined distance for prohibiting the, right turn
Set a predetermined continuous mileage, and within this
A branch point farther than the predetermined distance that prohibits turning
It is determined whether or not it exists, and the branch point
If there is no ban, it is prohibited to turn right or left over the specified distance.
A vehicle route guidance device for canceling and re-searching a route. 3. The apparatus according to claim 2, wherein the predetermined distance for prohibiting a right / left turn from the re-search start point is at that time.
Is determined based on the vehicle speed and the time required for re-searching, and
A route guidance device for a vehicle , wherein a predetermined distance is not zero when the vehicle speed is zero . 4. The apparatus according to claim 3 , wherein the right / left turn prohibition length when the vehicle speed is zero is changed according to the number of lanes.
A route guidance device for a vehicle, comprising: