JPH087618B2 - How to determine the vehicle travel route - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for determining a travel route of a vehicle, and in particular,
The present invention relates to a method for determining a travel route of a vehicle suitable for determining a travel route of an unmanned vehicle that conveys various articles in a factory or the like.

[Prior Art] A general unmanned vehicle used for transporting goods in a factory is guided and travels on a predetermined road by electromagnetic induction or the like. The route of the unmanned vehicle is usually determined and controlled by a central guidance management device. Also, some unmanned vehicles themselves determine the route. In any case, when guiding an unmanned vehicle from one station (hereinafter, a predetermined parking position of the unmanned vehicle is referred to as a station) to another station, the route is determined so that the traveling route becomes the shortest. Has become.

[Problems to be Solved by the Invention] However, in the conventional travel route determination method, only the route connecting from a certain point on the road to another point on the road is obtained in the shortest direction, and the station does not move in the traveling direction. No consideration was given to the left or right side of the road. As a result, for example, the luggage loading port may be on the right side of the unmanned vehicle, but the left side opposite may arrive at the station facing the station, and the subsequent work may be very inconvenient.

The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to provide a travel route determination method capable of selecting a shortest route such that a predetermined side of a vehicle faces a parking position and becomes an arrival state. To provide.

[Means for Solving the Problem] Therefore, in the present invention, a plurality of vehicles are arranged in a traveling path of a vehicle that can move forward and backward, and the vehicle travels between a plurality of stations that are parking positions of the vehicle.
A traveling route determination method of a vehicle for determining a traveling route of the vehicle in which the vehicle has a predetermined orientation with respect to a target point station and has the shortest traveling distance,
At least the location information about the intersection of the roads constituting the travel route and the plurality of stations on the road is stored in the database, and the distance between each of the intersections and the plurality of stations. And distance information about each of the plurality of stations, and position information about which of the left and right sides of the road with respect to a predetermined direction is stored,
By referring to the arrangement information of the start point station where the vehicle is currently parked and the arrangement information of the target point station of the vehicle, the start intersection adjacent to the start point station and the target Obtaining a target intersection adjacent to the point station, and referring to the position information of the station that is the starting point where the vehicle is currently parked and the position information of the station that is the target point of the vehicle, When the vehicle arrives at a target point station from among a plurality of traveling routes of the vehicle connecting the start intersection and the target intersection, the vehicle is oriented in a predetermined direction with respect to the target point station. Driving when the vehicle travels on the selected travel route by selecting the travel route of the vehicle and referring to the distance information Seeking away, out of the travel distance obtained said, the travel route exhibiting the minimum travel distance was determined as the travel path of the vehicle.

[Operation] First, location information about where road intersections and a plurality of stations that form a travel route are located on the road, and distance information about distances between the intersections and a plurality of stations. , A starting point at which the vehicle is currently parked from a database that stores position information about whether each of the plurality of stations is located on the left or right side of the road with respect to a predetermined direction. By referring to the arrangement information of the station and the arrangement information of the station that is the target point of the vehicle, a start intersection that is adjacent to the station that is the start point and a target intersection that is adjacent to the station that is the target point are obtained. .

Further, referring to the position information of the station which is the start point where the vehicle is currently parked and the position information of the station which is the target point of the vehicle from the database, the start intersection and the target intersection are identified. When the vehicle arrives at a target point station from among a plurality of connected vehicle travel routes, the vehicle travel route in which the vehicle is oriented in a predetermined direction with respect to the target point station is selected. . A plurality of this travel route is usually selected.

Further, referring to the distance information from the database, a traveling distance when the vehicle travels on the selected traveling route is obtained, and a traveling route exhibiting the shortest traveling distance among the obtained traveling distances is determined. It is determined as the travel route of the vehicle.

The travel route determined in this way is one of the travel routes of a plurality of vehicles connecting the start intersection and the target intersection, and when the vehicle arrives at the target point station, Select the traveling route of the vehicle in which the vehicle is in a predetermined direction,
From the selected travel routes, the travel route having the shortest travel distance is determined as the travel route of the vehicle. Therefore, if the vehicle is traveled according to the present invention, when the vehicle arrives at the target point station, the vehicle is oriented in a predetermined direction with respect to the target point station, and the shortest traveling distance is achieved. The vehicle travels on a travel route that presents. Therefore, for example, when there is a luggage loading port in a predetermined direction of the vehicle, when the vehicle arrives at the target station, the luggage loading port always faces the station side. The convenience of loading work is significantly improved.

[Example] A layout (map) in a factory where an unmanned vehicle is run will be described as shown in FIG.

In FIG. 1, two main lines are bidirectional roads, and one main line is a one-way road. The scale on the road is a distance scale. The letters a to m shown in lowercase letters (except for the lowercase letter l) are intersections (including bends). Capital letters A, B, B ′, C, D,
D'is a station, B and B ', D and D'
Are stations at the same location on both sides of the road.

Corresponding to this road map, a database (map data) shown in FIG. 2 is preliminarily provided, and based on this database, processing for determining a traveling route is performed by a computer as described later.

First, the structure of map data stored in the database will be described with reference to FIG.

Each road 1 to 8 is defined by the list in []. For example, the road 1 is a road connecting the intersections m, h, and c, and m → h →
The direction of c is the forward direction, and the opposite direction of c → h → m is the reverse direction. The 0 of m (0) in the list indicates that the intersection m is the origin of the road 1. Further, 4 in h (4) indicates the distance from the left adjacent position in the list (that is, the intersection m) to the intersection h. Similarly, 6 in c (6) indicates the distance from the intersection h to the intersection c.

The rightmost item in the list has a binary value of 1 or 0
Is a tag, 1 indicates that the road is bidirectional,
0 indicates that the road is one-way.

Further, the list of roads 4 indicates that the road 4 runs from the intersection h to the intersection i and the station A to the intersection j. And the distance of h → i is 2.5, i →
The distance A is 1, which is indicated by A (1), and the distance A → j is 1.5.
Is. Further, 1 on the right side of (A (1); 1) in the item of station A is a tag (denoted as "TAG") indicating the position of the station.

This TAG indicates whether the station is on the left or right side with respect to the road direction stored in advance in the database. TAG = 1 indicates that the station is on the left side of the road, assuming that the unmanned vehicle has traveled along the road in the forward direction (direction stored in the database).
= 0 indicates that the station is on the right side of the road, assuming it has proceeded in the forward direction.

The list of roads 5 shows that there are stations B'and B at a distance of 2 from the intersection c, B'to the right and B to the left.

The map data defining the roads 1 to 8 is prepared in advance as a database.

In addition, information on the direction of travel of the unmanned vehicle in the forward direction of the road
It is defined by the notation REC (α, β).

REC (α, β) indicates whether the direction from the intersection or station α to the intersection or station β is positive or negative with respect to the predetermined forward direction of the road. REC (α, β) ) = 0 positive direction, REC (α,
When β) = 1, it is in the negative direction.

For example, road 4 [h (0); i (2.5), (A (1);
1), j (1,5); 1], REC (h, A) = 0 and REC (A, h) = 1.

Next, the method of determining the traveling route will be described in detail with reference to the flowchart of FIG. 3, taking as an example the case of guiding from station A to station B '.

<Step 1> First, the start station A and the target station B ′ are designated.

<Step 2> Next, the road name and station information including the start station A and the road name and station information including the target station B ′ are obtained. This can be done by searching the database in FIG. 2 by station name and bringing the road name including it. That is, the following two roads are extracted from the database.

Road 4 [(h (0); i (2.5), (A (1); 1), j (1.
5); 1] Road 5 [c (0), (B '(2); 0), (B (0);
1), d (1), e (2.5); 1] <Step 3> Let TAG indicating the position of the start station (TAG is the same as the above definition) be STAG, and let TAG indicating the position of the target station be ETAG. .

Start station A is now in the forward direction of road 4 (h
Since it is on the left side with respect to → i → j directions), STAG = 1. Since the target station B'is on the right side of the road 5 in the forward direction, ETAG = 0.

<Step 4> Determine the start intersection. This is done by choosing the two closest intersections (intersection x and intersection y) to the start station, and then selecting the start intersection S point1 (x, FLAG1),
Obtained in the form S point2 (y, FLAG1).

 Here, FLAG1 = STAG * REC (a1, b1), a1 is the start station, b1 is the next intersection x or intersection y, and ◎ is the exclusive OR.

For example, the intersection next to Start Station A is x
= I and y = j, and two points, S point1 (i, 0) and S point2 (j, 1), are obtained as the starting intersections.

Because station A is on road 4 [h, i, A, j; 1]
Since the intersection i is in the direction opposite to the forward direction of the road 4 when viewed from the station A, REC (A, i) = 1, STAG = 1, and as a result, FLAG1 = STAG ◎ REC = 0 Becomes

Further, since the intersection j is in the forward direction of the road 4 as viewed from the station A, REC (A, j) = 0 and STAG = 1, and as a result, FLAG1 = STAG⊚REC = 1.

<Step 5> Next, the target intersection is determined. This is done by selecting the two intersections (intersection xx and intersection yy) that are closest to the target station and selecting the target intersections E point1 (xx, FLAG2), E point2 (y
y, FLAG2)

 FLAG2 = STAG * REC (a2, b2), where a2 is the next intersection xx or intersection yy, and b2 is the target station.

For example, the intersection next to the target station B'is xx =
c.yy = d, and two points E point1 (c, 0) and E point2 (d, 1) are obtained.

Because the station B'is in the middle of the road 5 and the station B'is in the forward direction of the road 5 as seen from the intersection c, REC (c, B ') = 0, ETAG = 0, and as a result, FLAG2 = ETAG ◎ REC = 0.

Since station B'is on the opposite side of road 5 as seen from intersection d, REC (d, B ') = 1, ETAG = 0, and as a result, FLAG2 = EATG * REC = 1.

<Step 6> As described above, the two start intersections S point1 (i, 0) and S point2 (j,
1) Two target intersections E point1 (c, 0), E point2 (d,
When 1) is obtained, next, a combination in which FLAG1 at the start intersection and FLAG2 at the target intersection are matched is created. That is, a combination of (start point, end point) is created.

In the above example, S point1 (i, 0) and E point1 (c, 0),
And, S point2 (j, 1) and E point2 (d, 1) are a combination of matching FLAG.

This means that if the intersection (i, 0) is used as the start intersection, and if (c, 0) is selected as the target intersection, the loading directions of the unmanned vehicle will match, and the intersection (j, 1) will also be started. Then, if (d, 1) is selected as the target intersection, it means that the loading directions of the unmanned vehicle are the same (see Fig. 4).

<Step 7> Start route search. Here, the shortest route is obtained by adding the distance data stored in the database.

Here, in the route search from the intersection i to the intersection c, if the entry from the intersection d to the station B ′ is allowed through the road 7, the loading direction is reversed. In order to prevent this, it is assumed that the route d-B 'does not exist separately from the beginning. Specifically, the road 5 [c (0), (B '
(2); 0), (B (0); 1), d (∞), e (2,5); 1], and run the shortest route search program with the distance of route d-B 'infinite. Good.

If the route from the intersection j to the intersection d is searched, the route c-B 'is assumed to be separated and does not exist, and the shortest route search program is executed. For example, road 5 [c (0), (B '(∞); 0), (B (0); 1), d
(1), e (2.5); 1] and execute the program.

As a result of executing the shortest distance search in this way, the route A-i-h-c-B 'and the route A-j-g-e-d-
Two solutions of B'are obtained. Here, route A-i-h
-C-B 'distance is L1, route A-j-g-e-d-
If the distance of B'is L2, then L1 = 1 + 2.5 + 6 + 2 = 11.5 L2 = 1.5 + 3 + 3 + 2.5 + 1 = 11 from the database in FIG. Therefore, a short route Aj-g-e-d-
B'is the solution.

Here, if FLAG1 = FLAG2 = 0, the route is not changed by the forward movement, and if FLAG1 = FLAG2 = 1, the route is changed by the backward movement, which means that the route needs to be changed. That is, as shown in FIG. 4, when an unmanned vehicle starting from station A follows a route (forward movement) from intersection i to station B ′ via intersection c,
The shipping directions are the same and no route change is required. On the other hand, on the route from the intersection j to the station B ′ via the intersection d (reverse movement), the shipping directions do not match unless the route is changed.

In this case, the unmanned vehicle allowed bidirectional travel, but if bidirectional travel is not possible, the shortest route is Aih-c-B 'determined by the forward route with FLAG1 = FLAG2 = 0. Become a route.

When the two-way traveling used in the above embodiment is possible, the FLAG of the obtained route combination is 1. Therefore, as shown in FIG. Is controlled so that it can be stored across the opposite route. And A-j-g-
The route ed-B 'realizes the shortest route.

As described above, according to the first embodiment described above, the TAG indicating whether the station is on the left or right side with respect to the road direction stored in advance in the database, and α for the road direction stored in the database. By matching or disagreeing with REC (α, β), which indicates whether or not the direction from to β is the same, at the start point and the end point, it is the shortest that switchback is not required by combining coincidence or disagreement It is possible to reliably obtain the route.

FIG. 5 shows a second embodiment of the present invention. In this embodiment, the present invention is applied when an unmanned vehicle has a switchback function.

For example, when the station is configured as shown in FIG. 6 (A) and the shipping direction is to the right of the traveling direction, the shipping direction matches the station even if the station enters the station as it is. However, if the shipping direction is to the left of the traveling direction, the shipping direction does not match the station as it is. In such a case, if the vehicle travels such that it passes through once and then is stored in the back (traveling as → in the figure), the shipping directions are the same for the stations. Also, at an intersection as shown in FIG. 7B, the vehicle travels straight ahead and then immediately backs up to turn at the intersection (traveling as → in the figure).
The shipping direction can be changed by performing. In this way, the running like → shown in FIGS. 6A and 6B is called switchback.

When there is a switchback function, as shown in the flowchart of FIG. 5, when the shortest route search is first performed, the combination of the start intersection and the target intersection is not considered,
The normal route search shown in step 6 is executed.

When the combination of FLAG1 and FLAG2 of the start intersection S point and the target intersection E point obtained at that time is {0,1} or {1,0}, that is, when the FLAGs do not match,
It is possible to judge that it is necessary to enter the vehicle using the switchback function once while traveling. In this case, as a penalty function, the distance required to perform the switchback is added. Of course, when the combination of FLAG1 and FLAG2 is {0,0}, {1,1} as seen in the above example, no penalty is imposed and the answer is obtained.

In this way, the route A-if-d-B 'is obtained. If the distance is L3, then L3 = 1 + 3 + 3 + 1 = 8. However, since FLAG1 and FLAG2 are a combination of {0,1} in this route, the distance L is L = 8 + L penalty.

Here, if L penalty is 3 ≧ L penalty, L ≦ 11
Therefore, the route A-if-d-B 'is selected as the shortest route. However, in this case, a switchback must be performed at the target station B '.

On the other hand, when L penalty> 4, L> 12. Therefore, the above Aj-g-e-d-B '(the distance L2 =
11) can be treated as the shortest route.

In the above description, the loading and unloading directions of stations are expressed only by the road position, but it is clear that the loading and unloading directions of stations may be added as information in addition to the road position.

[Effects of the Invention] As described in detail above, according to the present invention, when a vehicle reaches a target point station, the vehicle is oriented in a predetermined direction with respect to the target point station, and When the vehicle arrives at the target point station, for example, when the vehicle travels on the travel route that exhibits the shortest travel distance, and therefore, for example, when there is a luggage loading port in a predetermined direction of the vehicle, The luggage loading port faces the station side, and as a result, the convenience in the loading operation of the luggage is significantly improved, which is a very excellent effect.

[Brief description of drawings]

FIG. 1 is a road map for explaining one embodiment of the present invention,
FIG. 2 is a conceptual diagram of map data (database) corresponding to the road map, FIG. 3 is a flow chart of route determination processing according to the first embodiment of the present invention, and FIG. 4 is an operation explanatory diagram of the first embodiment, FIG. 5 is a flowchart of the route determination processing according to the second embodiment, and FIG. 6 is an explanatory diagram of switchback.

Claims (1)

[Claims] 1. When traveling a vehicle between a plurality of stations, which are parking positions of the vehicle, a plurality of which are arranged in a traveling path of the vehicle which can move forward and backward, the station which is a target point is traveled to the station. A method for determining a travel route of a vehicle in which a vehicle is oriented in a predetermined direction and has the shortest travel distance, and at least an intersection of roads constituting the travel route and the above Placement information about where on the road the plurality of stations are placed, distance information about the distance between the intersection and each of the plurality of stations, and each of the plurality of stations are determined in advance. The position information about whether the vehicle is on the left or right side of the road with respect to the specified direction is stored, and the vehicle is currently parked. By referring to the arrangement information of the station serving as the start point and the arrangement information of the station serving as the target point of the vehicle, the start intersection adjacent to the station serving as the start point and the station serving as the target point are located adjacent to each other. The target intersection is calculated, and the start intersection and the target intersection are identified by referring to the position information of the station that is the starting point where the vehicle is currently parked and the position information of the station that is the target point of the vehicle. When the vehicle arrives at the target point station from among the plurality of connected travel routes of the vehicle, the vehicle travel route in which the vehicle is oriented in a predetermined direction with respect to the target point station is selected. , The travel distance when the vehicle travels on the selected travel route by referring to the distance information, Among the traveled distances, the traveled route determining method that determines the traveled route having the shortest traveled distance as the traveled route of the vehicle.