JPH11259130A - Automatic guided vehicle route setting method and automatic guided vehicle control method - Google Patents

Abstract

(57) [Summary] [Problem] To provide an automatic guided vehicle route setting method capable of setting a transport route of an autonomous traveling type automatic guided vehicle without using a complicated method, and to provide an obstacle on a designated route. The present invention provides a method for controlling an automatic guided vehicle that can travel along the route as much as possible while avoiding an obstacle even if the vehicle exists. SOLUTION: A route setting system 10 is provided in a section for creating a traveling route at a position distant from a factory, and first sets a traveling lane by dividing a traveling area projected on a display screen into a grid pattern. By specifying an intersection of the travelable lanes, a turning point and a target point are set, and the set points are transmitted to the automatic guided vehicle in the traveling area, whereby the automatic guided vehicle is controlled. The traveling route is stored. The automatic guided vehicle inputs the coordinates of the direction change point and the target point in the memorized traveling area, travels to the target point while sequentially tracing these input points in a straight line, and travels between the two points. When an obstacle is encountered, the user changes the direction to a U-shape in a direction in which the obstacle can be avoided while watching the obstacle to avoid the obstacle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic guided vehicle route setting method capable of setting a transport route of a self-contained traveling automatic guided vehicle without using a complicated method, and an obstacle in a designated route. The present invention relates to a method for controlling an automatic guided vehicle that can travel along the route as much as possible while avoiding an obstacle even if the vehicle exists.

[0002]

2. Description of the Related Art In recent years, unmanned transport vehicles are frequently used to transport assembled parts of vehicles. In particular, recently, the use of an autonomous traveling type automatic guided vehicle capable of freely setting a traveling route has been increasing.

[0003] In this self-contained traveling type automatic guided vehicle, it is necessary to set a traveling route in advance. However, depending on how the traveling route is taken, the efficiency of the carrying operation is reduced. Various methods have been considered as a method for calculating the travel route.

One of the methods is a free space structuring method. This free space structuring method is roughly as follows.

First, a moving area (two-dimensional) is set, and an obstacle is set in the moving area. Next, the moving area is divided by connecting the boundary of the moving area from each vertex of the obstacle to the vertex of another obstacle or each vertex of the obstacle by a line segment (link). And connect the shortest vertices between obstacles and the shortest point between the vertex of the obstacle and the link,
The middle point of the line segment thus drawn is defined as a passing point.

According to this method, the automatic guided vehicle passes through an intermediate position between obstacles and also passes through an intermediate position between the obstacle and the moving area, and thus takes an ideal transport path. be able to.

[0007]

However, with such a conventional method, it is possible to create an ideal route, but the layout of the site is changed and the position of the obstacle is shifted. When such a situation occurs, not only must the environment of the traveling area be reset each time, but also the route must be re-created as a matter of course. In addition, since a large number of calculation processes are followed, it may be impossible to create a route (a solution cannot be found) depending on conditions.
In an automobile factory where layout changes are frequently made, it is difficult to create a route by applying this method.

Further, when an ideal route is set as in the prior art, the traveling route becomes very complicated, and the amount of data relating to the traveling route to be stored by the automatic guided vehicle becomes enormous. is there.

SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional problem, and has been developed in consideration of the conventional problem. It is an object of the present invention to provide a route setting method and a control method of an automatic guided vehicle that can travel along the route as much as possible while avoiding the obstacle even if an obstacle exists on the designated route. I do.

[0010]

The present invention for achieving the above object is constituted as follows. According to the first aspect of the present invention, the travel area projected on the display screen is divided into a grid pattern to set a travelable lane, and by specifying an intersection of the travelable lanes, a direction change point and a target point are set. By setting these points and transmitting the set points to the automatic guided vehicle in the traveling area, the traveling path is stored in the automatic guided vehicle, thereby setting the route of the automatic guided vehicle. Is the way.

According to a second aspect of the present invention, in the automatic guided vehicle route setting method according to the first aspect, an interval between the runnable lanes divided in a grid pattern is a minimum turning radius of the automatic guided vehicle. It is characterized by the above interval.

According to a third aspect of the present invention, in the automatic guided vehicle route setting method according to the first aspect, the turning point and the target point are specified in the order of passage.

According to a fourth aspect of the present invention, in the automatic guided vehicle route setting method according to the first aspect, the turning point and the target point are transmitted to the automatic guided vehicle as coordinates of a traveling area. It is characterized by.

According to a fifth aspect of the present invention, the coordinates of the direction change point and the target point in the travel area transmitted from the outside are input, and the input points are sequentially and linearly traced to the target point. It is a control method of an automatic guided vehicle characterized by running.

According to a sixth aspect of the present invention, in the control method of the automatic guided vehicle according to the fifth aspect, when an obstacle is encountered while traveling between the input two points, the obstacle is recognized. However, the obstacle is changed to a U-shape so as to avoid the obstacle so as to avoid the obstacle.

[0016]

The route setting method of the automatic guided vehicle according to the present invention configured as described above has the following effects. According to the invention described in any one of claims 1 to 4, by dividing the traveling area projected on the display screen into a grid pattern, a traveling lane is set, and an intersection of the traveling lane is designated. , Turning points and target points are set, and the set points are transmitted to the automatic guided vehicle in the traveling area, so that setting of turning points and target points can be easily created on the screen. And the travel route of the automatic guided vehicle can be created in a short time. Therefore, it is possible to quickly respond to changes in the environment of the traveling area. In addition, since the same turning point and target point can be transmitted to a plurality of automatic guided vehicles, the data at those points can be transmitted very efficiently.

According to the fifth aspect of the present invention, the coordinates of the direction change point and the target point in the travel area transmitted from the outside are inputted, and the inputted points are sequentially and linearly traced. Since the vehicle is driven to the target point, the automatic guided vehicle can travel only by storing the coordinates of the transmitted turning point and the coordinates of the target point, so that the vehicle can be driven with relatively simple control. .

According to the sixth aspect of the present invention, if there is an obstacle during traveling, the direction is changed to a U-shape so that the obstacle can be avoided while watching the obstacle. Since the obstacles were avoided, the turning points and target points to be stored in the automatic guided vehicle need not be accurate data, and they must be able to respond individually and quickly to changes in the on-site environment. Will be able to

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram of a control system that implements the method of the present invention. This control system includes an automatic guided vehicle route setting system 10 provided in a preparation section for creating a traveling route (a possible lane) of the automatic guided vehicle, and an automatic guided vehicle that controls the operation of the automatic guided vehicle traveling in a factory. The control system 50 is roughly divided into two. In other words, it is roughly classified into a global planner that globally creates a travel route and a local planner that creates an avoidance route while traveling when encountering an obstacle while traveling along the travel route. .

The route setting system 10 is provided in a section for creating a traveling route, which is usually located at a position distant from the factory. An operator of the creating section creates a traveling route of the automatic guided vehicle by operating a computer constituting the system 10. The system 10 includes a route setting unit 15 that divides the traveling area of the automatic guided vehicle in the factory displayed on the display screen into a grid pattern and sets a traveling route, and a path setting unit 15 for obstacles existing within the traveling area. A fixed obstacle setting unit 20 for setting the size and the shape is provided.

The travel route created by the system 10 is provided in the system 10 after the coordinates of the target factory are converted (the coordinates of the display screen are converted into the coordinates of the factory which is the travel area). Is transmitted to the automatic guided vehicle located in the factory by the route data transmitting unit 30. The method of creating the travel route will be described later in detail.

The automatic guided vehicle control system 50 is a system mounted on the automatic guided vehicle, and includes a route data receiving unit 40 that receives data on a traveling route transmitted via the route data transmitting unit 30 of the route setting system 10. A current position / posture detecting unit 42 for detecting the current position and posture of the automatic guided vehicle, an obstacle detecting unit 44 for detecting obstacles existing in the traveling direction (front, left front, right front), An obstacle avoiding operation determining unit for determining whether to change the travel route and a travel control unit;
Controls the traveling of the automatic guided vehicle 50 based on information from these parts (40, 42, 46). The drive unit 49 is for driving the drive wheels provided on the automatic guided vehicle.

Next, the operation of the above control system will be described in detail with reference to a flowchart. The flowchart shown in FIG. 2 shows the operation procedure of the route setting system 10 and shows the operation of the global planner that creates a global route.

First, an operator uses a computer constituting the route setting system 10 to develop a map of a traveling area to be created on a display based on CAD data (S1). The operator sets a travel route in block units while taking into consideration places on the map that cannot pass (fixed obstacles such as columns and equipment). That is, the travel region is divided into a grid pattern to set a travelable lane.
When dividing the traveling route, the interval between the traveling routes is
Keep a distance greater than the minimum turning radius of the automatic guided vehicle. For example, as shown in FIG. 4, a map of a traveling area is developed, obstacles (fixed obstacles) are set in the map, and the distance between pillars standing in the traveling area is considered. A grid-like running area is set (S2). Next, the worker sets the positions of the direction change point (subgoal) and the target point (goal) in the running order (passing order). These points are, of course, intersections between the lanes (S
3).

When the above input processing is completed by the operator, the route setting system 10 calculates the coordinates of the input turning point and the target point in the travel area (S4), and the order in which the coordinates are traveled (passing order). ) To the route data transmission unit 3
0 sends to the factory, i.e. to the guided vehicle (specific or all) traveling in the travel area.
Therefore, only the coordinates of the turning point and the coordinates of the target point on the traveling route are sent to the automatic guided vehicle.
The transmission may be performed using a local area network, or may be performed by another method if the distance to the factory is long (S5).

The traveling route transmitted in this manner is input to an automatic guided vehicle in a factory. An unmanned guided vehicle usually returns to its original position after completing work,
A device is provided for writing data indicating the destination of the automatic guided vehicle into the automatic guided vehicle. Therefore, the traveling route transmitted by using this device can be written in a specific automatic guided vehicle.

The operation of the automatic guided vehicle is controlled as shown in the flowchart of FIG. 3 on the basis of the travel route written in this way. Note that this automatic guided vehicle is provided with a function of creating an avoidance route while traveling when encountering an obstacle during traveling along the traveling route. The creation of the avoidance route will be described with reference to FIGS.

The automatic guided vehicle calculates a straight line formula connecting the current position value and the next subgoal (next direction change point) based on the transmitted data, that is, the coordinates of the direction change point and the target point. calculate. Note that the current position value is detected by the current position / posture calculation unit 42 (S11).

The automatic guided vehicle travels straight toward the next subgoal along the calculated straight line formula. When the vehicle reaches the subgoal, the vehicle turns 90 degrees toward the next subgoal. For example, in the case of FIG.
Go straight from the coordinates of 1) to the coordinates of (4,1),
The vehicle turns 90 degrees in front of the coordinates of (4, 1) (just before the turning radius), and then goes straight from the coordinates of (4, 1) to the coordinates of (4, 8). The traveling state of the automatic guided vehicle is determined based on the current position / posture detection unit 42 so that the traveling position does not deviate from the calculated straight line connecting (1, 1) and (4, 1). Controlled. Since this control is a commonly performed control, a detailed description of the control content is omitted (S12 to S14).

If there is an obstacle while traveling toward the next subgoal (S15), a process of traveling while avoiding this obstacle is performed. In other words, when the direction of successive subgoals (the next next subgoal) is right, if there is no obstacle in the right direction, it is possible to return to the original route even if the obstacle is avoided, The unmanned guided vehicle turns 90 degrees and travels along obstacles (S16 to S18, S21, S2
2) On the other hand, if there is an obstacle in the right direction, it is in an occupied state that cannot be reached in either direction, so it is stopped and an alarm is issued. The detection of an obstacle is performed by the obstacle detection unit 44. Obstacle avoidance operation judgment unit 4
6 instructs the travel control unit 48 to perform an avoidance operation (travel along an obstacle) based on the detection information of the obstacle detection unit 44. Since this avoidance operation is also a control that is generally performed, detailed description of the control content is omitted (S25).

When the direction of successive subgoals is left, if there is no obstacle in the left direction, there is a possibility of returning to the original route even if the obstacle is avoided.
Turn 0 degrees and run along the obstacle (S16, S1
(9, S20 to S22) On the other hand, if there is an obstacle in the left direction, the vehicle is stopped and an alarm is issued (S25) because the vehicle is in an occupied occupation in which the vehicle cannot go in either direction.

If the vehicle can return to the original straight line after traveling while avoiding the obstacle, the vehicle returns to the original straight line after avoiding the obstacle and travels straight while correcting for the next subgoal. If it is not possible to return to the original straight line even immediately before, it is stopped and an alarm is issued (S23 to S25).

That is, in the processing from S15 to S25,
If an obstacle is detected in the traveling direction, it is determined whether the block in the left-right direction can proceed (the direction opposite to the subgoal is given priority next). . On the other hand, if the vehicle cannot proceed, it stops and issues an alarm. Then, during obstacle avoidance traveling, it is determined whether the vehicle can return to the original straight line. If it can return, it returns, and if it cannot return, it continues to travel along the edge of the obstacle. During obstacle avoidance traveling, it is determined whether the vehicle has reached a position where it cannot return to the original straight line unless it makes a detour, and if it cannot return, it stops immediately and issues an alarm. The determination as to whether or not it is possible to return to the straight line is made by one block before the traveling direction, that is, at the limit position before the subgoal, and by determining whether it is possible to turn in the next subgoal direction.

Further, the movement of the automatic guided vehicle avoiding obstacles will be specifically described with reference to FIGS. In addition,
It is assumed that the following rules are set as the basic operation rules of the automatic guided vehicle.

(1) Position Correction The reduction ratio of the left and right wheels is output according to the amount of deviation from the current position based on the calculated straight line. If it deviates from the standard to some extent, it is considered abnormal.

(2) When reaching the end of the traveling block according to the edge of the obstacle, it is detected whether or not the vehicle can turn in the direction returning to the original straight line (whether there is no obstacle).
If not, proceed to the next block end.

(3) Judgment of Returning to the Original Straight Line Whether or not it is possible to turn so as to face the original straight line one block before the original straight line.

(4) When the vehicle is traveling avoiding the obstacle at the limit position judgment before the subgoal, the vehicle does not go too far in the original traveling direction. If the current position is on the subgoal side after the next subgoal one after another, is it possible to turn to the subgoal side in the line one block before the subgoal? If the current position is on the opposite side of the next subgoal, can you turn to the subgoal in the subgoal line?

(5) FIG.
It is assumed that a route like the following is set. That is, (4,
1) Turn left, (4,8) Turn right, (10, 8) Turn left, (1
It is assumed that (0,12) right turn and (12,12) stop are set.

As a premise, since the route as shown in FIG. 4 is set, as shown in FIG. 5A, if an obstacle exists on the straight line of the traveling route, the current position is (4, 4). ), The subgoals (10, 8) are located one after the other on the right side of the current position. Therefore, the vehicle travels along the obstacle from the left along the edge of the obstacle and follows the subgoal (10, 8). Drive on the straight line toward the subgoal one after another. Further, as shown in FIG. 5B, if the current position value is (4, 2), the subgoals (1
(0, 8) is located on the right side of the current position value, and therefore, the vehicle should normally turn with priority on the left side. However, in this case, it is impossible to turn, so that the vehicle follows the obstacle from the right side. Travel along the edge of the obstacle, return to the straight line to the subgoal (4, 8), and head toward the subgoal.

When an obstacle is present as shown in FIGS. 6A and 6B, it cannot be avoided from either the left side or the right side in any case. That is, it is not possible to return to the original straight line, that is, the straight line connecting (4, 1) and (4, 8). Although it is not possible to return to the original straight line in the case of FIG. 5A, it is possible to pass through the subgoal.

Further, in the case shown in FIG. 7, since it cannot be avoided anywhere, it cannot be avoided in this case. According to the control system having the above-described configuration, the traveling route of the automatic guided vehicle can be created by the preparation section, and the created traveling route can be created by sending the created traveling route to the automated guided vehicle in the factory. Therefore, the teaching operation of the traveling route to the automatic guided vehicle becomes very simple.

Further, the traveling route is created by dividing the traveling area into a grid pattern, and the automatic guided vehicle is basically made to travel in a straight line. Will be able to do it. Therefore, even when it is necessary to change the traveling route in a hurry, a quick response is possible.

Further, the automatic guided vehicle has a function of, when there is an obstacle in the received travel route, avoiding the obstacle by self-determination and automatically returning to the set travel route. Basically, it is only necessary to memorize the point to be changed and the target point. Therefore,
The amount of data to be stored is so small that it cannot be compared with the conventional one.

Therefore, it is possible to quickly create a traveling route as a whole. In addition, since this automatic guided vehicle basically only goes straight ahead except for avoiding obstacles and changing direction at a turning point, factory workers can also predict the movement of the automatic guided vehicle, It can be said that it is preferable in terms of safety.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an automatic guided vehicle control system that implements a method of the present invention.

FIG. 2 is a flowchart illustrating a procedure of an automatic guided vehicle route setting method.

FIG. 3 is a flowchart illustrating a control method of the automatic guided vehicle.

FIG. 4 is a diagram provided for describing a control method of the automatic guided vehicle.

FIG. 5 is a diagram provided for describing a control method of the automatic guided vehicle.

FIG. 6 is a diagram provided for describing a control method of the automatic guided vehicle.

FIG. 7 is a diagram provided for describing a control method of the automatic guided vehicle.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Route setting system, 15 ... Route setting part, 20 ... Fixed obstacle setting part, 30 ... Route data transmitting part, 40 ... Route data receiving part, 42 ... Current position / posture detecting part, 44 ... Obstacle detecting part , 46: an obstacle avoiding operation determining unit, 48: a traveling control unit, 49: a drive unit, 50: an automatic guided vehicle control system.

Claims (6)

[Claims] 1. A traveling area projected on a display screen is divided into a grid pattern to set a travelable lane, and a direction change point and a target point are set by designating an intersection of the travelable lanes. A route setting method for an automatic guided vehicle, wherein the set points are transmitted to the automatic guided vehicle in the traveling area so that the traveling path is stored in the automatic guided vehicle. 2. The route setting of the automatic guided vehicle according to claim 1, wherein an interval between the runnable lanes divided in a grid pattern is equal to or more than a minimum turning radius of the automatic guided vehicle. Method. 3. The method according to claim 1, wherein the turning point and the target point are specified in a passing order. 4. The method according to claim 1, wherein the turning point and the target point are transmitted to the automatic guided vehicle as coordinates of a traveling area. 5. The method according to claim 1, wherein coordinates of a direction change point and a target point in the travel area transmitted from the outside are inputted, and the vehicle travels to the target point while sequentially tracing these input points in a straight line. Control method of automatic guided vehicle. 6. When an obstacle is encountered while traveling between two input points, the obstacle is changed to a U-shape in a direction in which the obstacle can be avoided while watching the obstacle. The method of controlling an automatic guided vehicle according to claim 5, wherein the control is performed.