JP2001022442A - Control method for automatic guided vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To speedily correct the deviation of a rotary center when it occurs owing to slip or the like when the travel direction of a car body is changed at a bend point,. SOLUTION: A car body is stopped at a bend point, is rotated and it is stopped when a guide line on a new travel direction is detected in the center of one guide sensor between front and back guide sensors (S1 to S5). It, is judged whether the other guide sensor detects the guide line or not (S6). When it is detected (Y), travel control on the next travel direction is executed (S7). When the rotary center of the car body is deviated owing to slip and the other guide sensor does not detect the guide line (S6; N), a virtual deflection point is set at the end part of a side where the guide line exists in the guide sensor (S8), and travel control is executed (S9). When the guide sensor detects the actual guide line (S10; Y), the virtual detection point is released (S11), and travel control is executed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling an automatic guided vehicle having a guide sensor for detecting a guide line laid on a traveling path, which is located before and after the bottom of a vehicle body in the traveling direction.

[0002]

FIG. 10 shows a system in which an unmanned transport vehicle (or a mobile robot having a robot arm mounted on an unmanned transport vehicle) performs various operations while traveling along a traveling path. As shown in the drawing, a guide line 2 made of, for example, a magnetic tape is laid along a traveling direction (direction of an arrow A) on a traveling path 1 and a stop marker 3 is laid at a required stop position. on the other hand,
Guide sensors 5 and 5 for detecting the guideline 2 are provided at the bottom of the body 4 of the automatic guided vehicle, respectively, in the front and rear directions of travel.
Is provided with a stop marker detection sensor 6 for detecting the stop marker.

[0003] In this case, although not shown, the vehicle body 4 has a traveling mechanism composed of, for example, two left and right driving wheels, two or four driven wheels (casters), etc., driven by separate driving motors. It is built in. Then, the travel controller composed of a microcomputer or the like controls the vehicle body 3 while steering the guide line 2 so as to pass through the center of the two guide sensors 5.
The traveling mechanism is controlled so as to stop at a required stop position based on the detection of the stop marker detection sensor 6. In addition, the steering of the vehicle body 4 is performed by the difference between the rotation speeds of two drive wheels, or there is a case where the direction of the wheels is changed by a steering motor.

By the way, the traveling path 1 (guideline 2) generally includes a number of branches and intersections or L
There are corners or the like that bend in a character shape, and at such a turning point, the traveling of the automatic guided vehicle while changing the direction of the vehicle body 4 is performed. Now, for example, as shown in FIG.
The direction (traveling direction) of the vehicle body 4 that has proceeded in the direction of arrow A along the guideline 2 is indicated by the arrow B at the turning point (intersection) P
When the direction is changed, the guideway 7 that crosses the guideline 2 at an angle and the rotation stop marker 8 are provided on the travel path 1.

When the traveling direction is changed, the vehicle body 4 of the automatic guided vehicle is moved in a state where the center of the vehicle body 4 coincides with the turning point P by detecting the stop marker 3 by the stop marker detecting sensor 6. It stops (rotates) in the direction of arrow C after that, and stops when the stop marker detection sensor 6 detects the rotation stop marker 8. The rotation (rotation) of the vehicle body 4 is performed by driving two driving wheels at the same speed in opposite directions. Further, as shown in FIG. 12, there is a method in which the rotation is stopped by the guide sensors 5 and 5 before and after detecting the guide line 7 without providing the rotation stop marker 8.

However, when the vehicle body 4 is rotated as described above, slipping or idling may occur between the road surface of the traveling path 1 and the driving wheels, and the slipping or the like may cause the rotation of the vehicle body 4. This causes a situation where the center deviates from the turning point P. If such a shift of the rotation center of the vehicle body 4 occurs, the stop marker detection sensor 6 cannot detect the rotation stop marker 8 in the rotation stop method shown in FIG.
Eventually, the automatic guided vehicle stops moving and stops.

Further, in the method shown in FIG. 12, if the rotation center of the vehicle body 4 is shifted, a situation occurs in which the two guide sensors 5 cannot simultaneously detect the guide line 7.
In this case, when one of the guide sensors 5 detects the guide line 7, the rotation can be stopped, but thereafter, the vehicle body 4 advances while searching for a course so that the other guide sensor 5 detects the guide line 7. It is necessary to perform the correction, and it takes a long time to perform the correction, and a problem such as an increase in meandering is caused.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to change the traveling direction of a vehicle body at a turning point on a traveling road even if the center of rotation is shifted due to factors such as slip. Another object of the present invention is to provide a method for controlling an automatic guided vehicle that can quickly perform the correction.

[0009]

According to a first aspect of the present invention, there is provided a method for controlling an automatic guided vehicle, wherein when a turning direction of a vehicle body is changed at a turning point on a traveling path, one of the guide sensors is newly provided at the turning point. The vehicle body is rotated until a guideline related to the traveling direction is detected, and when the other guide sensor does not detect the guideline in the state where the rotation is completed, the other guide until the guideline is actually detected. It is characterized in that the vehicle travels while imagining that the guideline is detected at the end of the left and right sides of the sensor where the actual guideline exists.

[0010] According to this, the vehicle body is rotated until one of the guide sensors detects a guideline relating to a new traveling direction at the turning point, and at this time, the displacement of the rotation center of the vehicle body due to wheel slip or the like is reduced. If not, the other guide sensor also detects the guide line, and the traveling direction is changed to the normal posture. On the other hand, if the rotation center of the vehicle body is shifted, the rotation may end in a state where the other guide sensor does not detect the guide line, but thereafter, the guide line is detected at the end of the other guide sensor. As a result, the vehicle body runs while being imagined, and the posture of the vehicle body is gradually corrected so that the other guide sensor approaches the guide line.

In this case, even if only one of the front and rear guide sensors detects the guide line, there is no problem that the vehicle body cannot move any more, and it is not necessary to search for a course. It does not take a long time or meandering. As a result, according to the first aspect of the present invention, when the traveling direction of the vehicle body is changed at the turning point on the traveling road, even if the center of rotation is shifted due to factors such as slippage, the correction is promptly performed. It has an excellent effect that it can be performed.

When a guide line is imagined at the end of the other guide sensor, the guide line relating to the new traveling direction exists on either side of the other guide sensor, that is, on the left and right sides of the guide sensor. Which end point the virtual point is set can be reliably determined based on the direction in which the vehicle body has rotated and whether the other guide sensor has crossed the guide line (the invention of claim 2).

According to a third aspect of the present invention, there is provided a method for controlling an automatic guided vehicle, wherein when a turning direction of a vehicle body is changed at a turning point on a traveling path, one of the guide sensors at the turning point relates to a new running direction. When the vehicle body is rotated until the rotation is detected, and the rotation is completed, and the other guide sensor does not detect the guide line, the position of one of the guide sensors is set to the rotation center, and the other guide sensor is set to the rotation center. The feature is that the car body is rotated again until the guideline is detected.

[0014] According to this, the vehicle body is rotated until one of the guide sensors detects a guideline relating to a new traveling direction at the turning point, and at this time, the deviation of the rotation center of the vehicle body due to wheel slip or the like occurs. If not, the other guide sensor also detects the guide line, and the traveling direction is changed to the normal posture. On the other hand, if the center of rotation of the vehicle body shifts, the rotation may end in a state where the other guide sensor does not detect the guide line. In this case, the position of one guide sensor is set to the center of rotation. Then, the vehicle body is rotated again until the other guide sensor detects the guideline.

Therefore, the vehicle body is brought into a normal posture in which both guide sensors detect the guide line. As a result, according to the first aspect of the present invention, when the traveling direction of the vehicle body is changed at the turning point on the traveling road, even if the center of rotation is shifted due to factors such as slippage, the correction is promptly performed. It has an excellent effect that it can be performed.

Further, the above one guide sensor and the other guide sensor may be fixed, for example, one on the front side in the traveling direction and the other on the rear side in the traveling direction. The guide sensor that has detected the guide line first may be used as one of the guide sensors (the invention of claim 4). According to this, the rotation is stopped in a shorter time, and efficient rotation control is performed. Can be performed.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS <First Embodiment> A first embodiment of the present invention will be described below with reference to FIGS. First, although not shown in detail, a brief description will be given of, for example, an article transfer system in a factory where the automatic guided vehicle 11 according to the present embodiment is used. The article transport system includes a plurality of facilities (not shown) along a traveling path 12 (partially shown in FIGS. 2 and 4) on which the automatic guided vehicle 11 travels. The unmanned guided vehicle 11 has a traveling path 12
To stop at a predetermined stop position in front of the facility, and work such as transfer (transfer) of a work (for example, a pallet on which parts are placed) is performed with the facility. .

In this case, guide lines 13 for guiding the automatic guided vehicle 11 are laid on the traveling path 12. The guideline 13 has a predetermined width (for example, 5c
m) Magnetic guide tape. At this time, the traveling path 12 has many branches and intersections or corners bent in an L-shape. For example, when the intersections cross each other in a cross shape, as shown in FIG.
The guide line 14 is laid so as to intersect with the guide line 3. At such a turning point P,
The traveling direction of the automatic guided vehicle 11 is changed. Although not shown, a stop marker made of a magnetic marker is provided on the traveling path 12 corresponding to a required stop position such as in front of each facility or a turning point.

Here, the configuration of the automatic guided vehicle 11 according to the present embodiment will be described with reference to FIGS. As shown in FIG. 2, the vehicle body 15 of the automatic guided vehicle 11 is formed in a substantially rectangular box shape that is slightly longer in the front-rear direction, and a loading platform on which a work is placed is provided on an upper surface thereof. Also, body 1
A travel mechanism 16 is provided at the bottom of the apparatus 5, and a travel controller 17 (shown only in FIG. 3) serving as control means for controlling the travel mechanism 16 is provided inside.

In the present embodiment, the traveling mechanism 16 is provided with the structure shown in FIG.
As shown in the figure, a left front portion and a right rear portion of the bottom portion of the vehicle body 15, that is, two driving wheels 18 and 19 are provided at a pair of diagonals, and symmetrically, that is, at the other diagonal. And two casters (driven wheels) 20, 20. As shown in FIG. 3, the front left and right rear drive wheels 18 and 19 are connected to drive motors 21 and 22 via reduction gears, respectively, and are freely (individually controlled in speed and speed) by these drive motors 21 and 22. The rotation direction can be controlled).

Then, as shown in FIG.
At the bottom of the vehicle body 15, front and rear guide sensors 23 and 24 for detecting the guide lines 13 and 14 are provided at front and rear central portions. The guide sensors 23 and 24 are formed by arranging a plurality of magnetic sensor elements in the horizontal direction.
(For example, 5 cm), the detection width is sufficiently wide (for example, 20 cm). At this time, the guide sensor 2
3 and 24 are guidelines 13 and 14 from the center.
Can be detected also in the left-right direction.

The detection signals of the front and rear guide sensors 23 and 24 are input to the travel controller 17 as shown in FIG. Further, the vehicle body 15
Is provided with a stop marker sensor 25 for detecting the stop marker. The stop marker sensor 25 is composed of a magnetic sensor that detects the stop marker at a point. As shown in FIG. 3, the detection signal of the stop marker sensor 25 is also input to the travel controller 17.

The travel controller 17 is controlled by the CP
The travel controller 17 mainly stores a microcomputer including a U, a ROM, a RAM, and the like. The travel controller 17 stores map data indicating the travel path 12 and each facility (stop position). Program is input. As shown in FIG. 3, the travel controller 17 controls the respective drive motors 21 and 22 via the motor drive circuit 26 to travel and stop the automatic guided vehicle 11 in accordance with them.

In this case, when the vehicle body 15 is traveling, the traveling controller 17
The vehicle body 15 travels on the upper and lower sides 3 and 14 while correcting the lateral displacement so that the centers of the front and rear guide sensors 23 and 24 are located. In this embodiment, the left and right steering of the vehicle body 15 is performed by making the rotational speeds of the drive motors 21 and 22 different, that is, by giving a speed difference to the left and right drive wheels 18 and 19. Also,
The travel controller 17 stops the vehicle body 15 at a predetermined stop position based on the detection of the stop marker by the stop marker sensor 25.

When the traveling controller 17 changes the traveling direction of the automatic guided vehicle 11 at the turning point P on the traveling path 12, the traveling controller 17 stops after the center of the vehicle body 15 is aligned with the turning point P. , Traveling mechanism 16 (drive motor 2
1 and 22) to drive the left and right drive wheels 18 and 19 to rotate in opposite directions at the same speed so that the center of the vehicle body 15 (the center of the line connecting the drive wheels 18 and 19) is the center of rotation. O (see FIG. 4), the vehicle body 15 is rotated (rotated).
It is made to let.

At this time, as will be described later, the travel controller 17 executes the control method according to the present embodiment by its software configuration. That is, the vehicle body 15 is rotated until one of the guide sensors 23 and 24 (the one detected earlier) at the turning point P detects the guide line 14 relating to the new traveling direction, and in the state where the rotation is completed, the other body is rotated. Guide sensor 2
When the guides 4 and 23 detect the guideline 14, the travel mechanism 16 is controlled so as to travel along the guideline 14 relating to the new traveling direction.

On the other hand, when the other guide sensor 24, 23 does not detect the guide line 14 at the time of rotation stop, the other guide sensor 24, 23 does not detect the guide line 14 until the guide guide 14 is actually detected. The vehicle body 15 is caused to travel while imagining that the guide line 14 is detected at the end of the left and right sides where the actual guide line 14 exists. In addition, the guideline 14 relating to the new traveling direction is
Which one of the two sides 4 and 23 is present is determined based on the rotation direction of the vehicle body 15.

Next, the operation of the above configuration will be described with reference to FIGS. Here, as shown in FIG. 4, an arrow a is drawn along a guide line 13 extending in the left-right direction.
The vehicle body 15 traveling in the direction (to the right in the figure)
After stopping at, counterclockwise (counterclockwise) indicated by arrow c
A case where the vehicle body 15 is rotated in the direction, the traveling direction of the vehicle body 15 is changed by 90 degrees in a direction along the guideline 14, and then the vehicle body 15 travels in the direction of arrow b will be described as a specific example.

The flowchart of FIG.
3 shows a control procedure executed by the travel controller 17 when the traveling direction of the vehicle body 15 is changed. That is, first, in step S1, the automatic guided vehicle 11 (vehicle body 15) is stopped at the turning point P. The stop of the vehicle body 15 is performed based on detection of a stop marker (not shown) by the stop marker sensor 25. In the example of FIG. 4, as shown in FIG. 4A, the vehicle body 15 traveling in the direction of arrow a along the guideline 13 changes to the guideline 13 as shown in FIG.
Is stopped in a state where the center (rotation center O) of the turning point P, which is the intersection of the guide line 14 with the new traveling direction, coincides with the turning point P.

Next, in step S2, a flag for the rotation direction is set, and in step S3, rotation control for the traveling mechanism 16 is performed. In this case, as described above, the vehicle body 15 is rotated (rotated) about the rotation center O by rotating the left and right drive wheels 18 and 19 in the opposite directions at the same speed. In the example of FIG. 4B, the left front drive wheel 18 is rotated in the backward direction, and the right rear drive wheel is rotated in the forward direction.
5 is rotated in the direction of arrow c.

In the next step S4, any one (one)
It is determined whether or not the guideline 14 relating to the new traveling direction is detected at the center of the guide sensors 23 and 24, and when the guideline 14 is detected (Yes in step S4), the rotation of the vehicle body 15 is stopped (step S4). S5). And
In step S6, it is determined whether or not the other guide sensors 24 and 23 detect the guide line 14 relating to the new traveling direction while the vehicle body 15 is stopped.

Here, in the example of FIG. 4, the vehicle body 15 is rotated from the state of FIG. 4B, and if the rotation is ideally performed, the guide line 14 is detected at the center of the front guide sensor 23, for example. If the rotation is stopped at this point, the guideline 14 is detected at the center of the other, that is, the rear guide sensor 24 as shown in FIG. In this state, the change of the traveling direction has been correctly performed, and the vehicle body 15 can be continuously driven in the direction of the arrow b without any problem.

Although not shown, guidelines 14
Is slightly deviated from the center of the rear guide sensor 24, as long as it is within the detection range of the guide sensor 24.
The turning of the traveling direction of the vehicle is almost accurately performed.
In the direction of arrow b. Therefore, if the other guide sensors 24 and 23 have detected the guideline 14 relating to the new traveling direction (Y in step S6).
es) Then, the traveling control for the next traveling direction is executed as it is (step S7).

However, when the vehicle body 15 is rotated as described above, slip or idle rotation may occur between the road surface of the traveling path 12 and the drive wheels 18 and 19, and the slip or the like may cause the vehicle body 15 to rotate. This causes a situation in which the 15 rotation centers O deviate from the turning point P. When the deviation of the rotation center of the vehicle body 15 becomes large, one of the guide sensors 23,
Even if the rotation is stopped in a state where the guide line 14 is detected at the center of the guide line 24, the other guide sensors 24 and 23 may not detect the guide line 14 (step S6).
No).

In such a case, FIG.
The rotation center O of the vehicle body 15 is shifted leftward from the turning point P, and the guide line 14 is positioned at the center of the front guide sensor 23.
Is detected, but stopped in a state where the guide line 14 is out of the detection range of the rear guide sensor 24. FIG. 4E shows the rotation center O of the vehicle body 15.
Is shifted to the right from the turning point P, and the guideline 14 is detected at the center of the rear guide sensor 24, but the guideline 14 is detected from the detection range of the front guide sensor 23.
Shows an example of stopping in a state where is removed.

In such a case (step S
No. 6), in the next step S8, the guide sensors 24 and 23 on the other side (the side deviating from the guideline 14)
A virtual detection point V that is assumed to detect the guideline 14 (shown with hatching for convenience)
Is set. This virtual detection point V is set at the end of the left and right sides of the other guide sensors 24 and 23 on the side where the actual guideline 14 exists.
At this time, since the rotation direction of the vehicle body 15 was counterclockwise, as shown in FIG.
Is set at the right end, and as shown in FIG.
In the case of the front guide sensor 23, it is set at the left end.

After the virtual detection point V is set as described above, the traveling control of the vehicle body 15 in the next traveling direction (the direction of the arrow b) is executed (step S9).
In this case, since the control is performed while correcting the lateral displacement (the posture of the vehicle body 15) so that the guide line 14 comes to the center of the guide sensors 24 and 23, the rear guide sensor 24 as shown in FIG. If the virtual detection point V is set at the right end, lateral displacement correction is performed such that the rear side of the vehicle body 15 is shifted to the right (the guideline 14 is relatively shifted to the left). FIG. 4 (e)
If the virtual detection point V is set at the left end of the front guide sensor 23 as described above, lateral displacement correction such as moving the front side of the vehicle body 15 to the left (the guideline 14 relatively moves to the right) is performed. Will be done.

By performing the lateral displacement correction after setting the virtual detection point V as described above, the other guide sensors 24 and 23 finally come on the actual guide line 14 and the other guide sensor 24 , 23 detect the actual guideline 14 (Yes in step S10), the virtual detection point V is released (step S11). As a result, normal traveling control is performed (step S7), and both guide sensors 23 and 24 are controlled.
The vehicle body 15 can be caused to travel in the direction of the arrow b while performing the lateral displacement correction based on the detection of.

According to this embodiment, the traveling path 12
When the traveling direction of the vehicle body 15 is changed at the upper turning point P, even if the rotation center O is deviated due to a factor such as a slip, the posture of the vehicle body 15 is promptly thereafter based on the setting of the virtual detection point V. Is corrected. Therefore, even if only one of the front and rear guide sensors 23 and 24 detects the guideline 14, a problem that the vehicle body 15 cannot move any more does not occur, and it is not necessary to search for a course. The correction does not take a long time or cause a large meandering problem. As a result, according to the present embodiment, the vehicle body 15
This has an excellent effect that the posture can be corrected quickly.

<Second Embodiment> Next, a second embodiment of the present invention will be described with reference to FIGS. In the second embodiment, the hardware configuration of the automatic guided vehicle 11 and the configuration of the traveling path 12 (guidelines 13 and 14) are the same as those in the first embodiment. , And reference numerals are used in common, new illustration and detailed description are omitted, and the following description will focus on differences.

This embodiment is different from the first embodiment in the software configuration of the travel controller 17.
The control method executed on the traveling mechanism 16 when the traveling direction of the vehicle body 15 is changed at the turning point P is different. That is, as described in the following flowchart description,
When the traveling direction is changed, first, as in the first embodiment, the vehicle body 15 is stopped with the center of the vehicle body 15 coincident with the turning point P, and the center of the vehicle body 15 is set as the rotation center O. , One of the guide sensors 2 (the one detected earlier)
The vehicle body 15 is rotated (rotated) until the guide lines 3 and 24 detect the guide line 14 relating to the new traveling direction.

When the other guide sensor 24, 23 does not detect the guide line 14 in the state where the rotation is completed, the center of rotation of the guide sensor 23, 24, that is, the rotation center O 'is placed on the guide line 14. After the setting, the vehicle body 15 is rotated again until the other guide sensors 24 and 23 detect the guide line 14.

The flowchart of FIG. 5 shows a control procedure executed by the traveling controller 17 when the traveling direction of the vehicle body 15 of the automatic guided vehicle 11 is changed. Also,
Here, as shown in FIG. 6, the vehicle body 15 traveling in the direction of arrow a along the guide line 13 extending in the left-right direction is also used.
Is stopped at the turning point P, and then rotated in the counterclockwise direction shown by the arrow c to change the traveling direction of the vehicle body 15 by 90 degrees in the direction along the guideline 14, and then in the direction of the arrow b A description will be given of a case in which the vehicle is run as a specific example.

In steps S1 to S5, the vehicle body 15 stopped at the turning point P is
Is rotated (rotated) about the rotation center O, and the rotation is stopped when a guideline 14 relating to a new traveling direction is detected at the center of one (one) of the guide sensors 23 and 24 ( 4 (a), (b) and (c). Then, while the vehicle body 15 is stopped, it is determined whether or not the other guide sensor 24, 23 has detected the guideline 14 relating to the new traveling direction (step S6). If it has been detected (Yes), The traveling control for the next traveling direction is executed as it is (step S7).

However, the rotation center O of the vehicle body 15 is deviated from the bending point P due to the occurrence of slippage of the drive wheels 18 and 19, and the guide sensor 14 is rotated at the center of one of the guide sensors 23 and 24 in a state where the guide line 14 is detected. Is stopped, the other guide sensors 24 and 23 may not detect the guide line 14. FIG. 6A shows an example in which the guide line 14 is stopped in a state where the guide line 14 deviates from the detection range of the rear guide sensor 24, and FIG. Shows an example of stopping in a state where is removed.

Therefore, in such a case (step S
No. 6), in the next step S21, one of the guide sensors 2 (the side detecting the guideline 14 at the center)
The rotation center O 'is set at the center position of the rotation center 3 or 24. At the same time, the rotation direction flag is set in step S22.
Is rotated (rotated) about the '. still,
The rotation direction in step S22 is the same as the rotation direction in step S3, that is, if the rotation direction in step S3 is counterclockwise, it is also set to counterclockwise.

In the example of FIG. 6, when the guide line 14 is out of the detection range of the rear guide sensor 24 as shown in FIG. 6A, as shown in FIG. Is set at the center position (on the guide line 14), and the vehicle body 15 is rotated in the direction of arrow d. Further, when the guide line 14 is out of the detection range of the front guide sensor 23 as shown in (c), the rotation center O is placed at the center position of the rear guide sensor 24 as shown in (d). Is set, and the vehicle body 15 is rotated in the direction of arrow e.

This rotation is caused by the other guide sensors 24, 2
The process is performed until the guideline 14 is detected at the center of Step 3 (Step S24). The other guide sensor 24, 23
When the guideline 14 is detected at the center of the arrow (Yes in step S24), the rotation of the vehicle body 15 is stopped (step S25). In this state, both the guide sensors 23 and 24 move in the new traveling direction. Since the guideline 14 is detected, the traveling control for the next traveling direction is executed as it is (step S7).

According to the present embodiment, the traveling path 12
When the traveling direction of the vehicle body 15 is changed at the upper turning point P, the center position of the one of the guide sensors 23 and 24 is set as the rotation center O 'even if the rotation center O is shifted due to factors such as slip. After that, the vehicle body 15 is rotated again until the other guide sensor 24, 23 detects the guide line 14, so that the vehicle body 15 is eventually
Both the guide sensors 23 and 24 are set to the normal posture in which the guide line 14 is detected.

Therefore, when changing the traveling direction of the vehicle body 15 at the turning point P, the front and rear guide sensors 23, 2
Even when only one of the guide lines 14 detects the guideline 14, there is no problem that the vehicle body 15 cannot move any more, and it is not necessary to search for a course. There is no inconvenience such as meandering. As a result, according to the second embodiment as well, there is an excellent effect that the posture of the vehicle body 15 can be corrected quickly.

<Other Embodiments> In each of the above-described embodiments, when either one of the guide sensors 23, 24 detects the guide line 14 first during the rotation control of the vehicle body 15 (steps S3, S4), the I stopped the rotation,
For example, the guide sensor 23 on the front side in the traveling direction may be fixed to one of the guide sensors, and the rotation may be stopped in a state where the guide sensor 23 detects the guide line 14.

In this case, the case where the other guide sensor 24 deviates from the guide line 14
When the other is rotated, the other guide sensor 24
May be crossed to the opposite side. In this case, the setting position of the virtual detection point (step S
8) and the rotation direction (step S22) when rotating the vehicle body 15 again must be reversed. Therefore, when one guide sensor is fixed, it is detected whether or not the other guide sensor crosses the guide line 14 when the vehicle body 15 rotates, and a virtual detection point and a rotation direction are set based on the detection. Good.

In each of the above embodiments, the traveling mechanism 16
As a result, driving wheels 18 and 19 are provided at diagonal portions of the vehicle body 15,
Although the casters 20 and 20 are provided on the other diagonal, various configurations are possible for the configuration of the traveling mechanism. For example, as shown in FIG. 7, a pair of drive wheels 32 are provided on the left and right portions of the vehicle body 31 in the front-rear direction, and casters 33 are provided at four corners of the vehicle body 31, or as shown in FIG. , A steerable drive wheel 35 is provided at the front center, and casters 36 are provided at the left and right sides of the rear. The steering of the vehicle body 15 is controlled by the left and right drive wheels 18, 1.
Instead of using the speed difference of 9, the angle of the wheels themselves may be changed by a steering motor or the like.

Further, in the above embodiment, the intersection between the guideline 13 and the guideline 14 is defined as a turning point P.
Although the case where the traveling direction of the vehicle body 15 is changed by 90 degrees has been described as a specific example, as shown in FIG. 9, there are various modes of the turning point P. FIG. 9A shows an example in which a guide line (traveling path) 41 is bent in an L-shape and its corner is a turning point P. In this case, for control (detection by a guide sensor), For example, sensor compensation paths 42 and 43 (shown by broken lines for convenience) made of a magnetic tape are provided with a required length.

FIG. 9B shows the guideline 44.
, A guide line 45 is branched in a Y-shape, and the branch point is set as a turning point P. In this case as well, a sensor compensation path 46 is provided. FIG. 9C shows an example in which the guide line 47 and the guide line 48 are connected in a T-shape, and the connection point is a turning point P.
Also at this time, a sensor compensation path 49 is provided.

In addition, the present invention is not limited to the embodiments described above and shown in the drawings. For example, the guide system of the automatic guided vehicle is not limited to the magnetic guide system using a magnetic tape and a magnetic sensor. Optical guide system that detects the reflected light of the guide line consisting of reflective tape with a guide sensor consisting of an optical sensor, and electromagnetic induction system that detects the low-frequency current flowing through the guide line consisting of a guide wire with a guide sensor consisting of a pickup coil Alternatively, the present invention can be applied to a mobile robot having a robot arm mounted on an unmanned carrier, and the present invention can be appropriately modified and implemented without departing from the gist of the invention.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of the present invention, and is a flowchart showing a control procedure when changing the traveling direction of a vehicle body.

FIG. 2 is a plan view schematically showing the configuration of an automatic guided vehicle.

FIG. 3 is a block diagram schematically showing an electric configuration of the automatic guided vehicle.

FIG. 4 is a diagram schematically showing a state when the vehicle body is rotating.

FIG. 5 is a view corresponding to FIG. 1, showing a second embodiment of the present invention;

FIG. 6 is a diagram corresponding to FIG. 4;

FIG. 7 shows another embodiment of the present invention, and is a plan view showing a configuration of a traveling mechanism.

FIG. 8 is a diagram corresponding to FIG. 7, showing a configuration of a different traveling mechanism.

FIG. 9 is a plan view showing examples of different turning points;

FIG. 10 shows a conventional example, and is a plan view showing a relationship between a guide line and a guide sensor.

FIG. 11 is a diagram showing a state in which the traveling direction of the vehicle body is changed using a rotation stop marker.

FIG. 12 is a diagram showing a state in which the traveling direction of a vehicle body is changed using a guideline.

[Explanation of symbols]

In the drawing, 11 is an automatic guided vehicle, 12 is a traveling path, and 13,1
4,41,44,45,47,48 are guidelines, 1
5, 31, and 34 are vehicle bodies, 16 is a travel mechanism, 17 is a travel controller, 18, 19, 32, and 35 are drive wheels, 21,
22 is a drive motor, 23 and 24 are guide sensors, 42 and
43, 46, 49 are sensor compensation paths, P is a turning point, O,
O 'indicates the center of rotation, and V indicates the virtual detection point.

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Claims (4)

[Claims] 1. A guide line laid on a traveling path is detected by guide sensors provided before and after the bottom of the vehicle body in the traveling direction, and based on the detection, the traveling mechanism is controlled while correcting a lateral displacement, and the vehicle body is controlled. A method of controlling the traveling mechanism when the traveling direction of the vehicle body is changed at a turning point on the traveling path in the automatic guided vehicle that is caused to travel, wherein one of the guide sensors is provided at the turning point. The vehicle body is rotated until a guideline relating to a new traveling direction is detected. When the other guide sensor does not detect the guideline in a state where the rotation has been completed, the other guide sensor does not detect the guideline until the guideline is actually detected. It is assumed that the guideline is detected at the end of the left and right sides of the guide sensor where the actual guideline exists. Control method for an automated guided vehicle, characterized in that for running the vehicle body while. 2. The guidelines for the new heading are:
2. The automatic guided vehicle according to claim 1, wherein which one of the two sides of the other guide sensor is present is determined based on a rotation direction of the vehicle body and whether the guide sensor crosses the guide line. Control method. 3. A guide line laid on a traveling path is detected by guide sensors provided before and after the bottom of the vehicle body in the traveling direction, and based on the detection, the traveling mechanism is controlled while correcting a lateral shift, and the vehicle body is controlled. A method of controlling the traveling mechanism when the traveling direction of the vehicle body is changed at a turning point on the traveling path in the automatic guided vehicle that is caused to travel, wherein one of the guide sensors is provided at the turning point. The vehicle body is rotated until a guideline relating to a new traveling direction is detected. When the other guide sensor has not detected the guideline in a state where the rotation has been completed, the position of the one guide sensor is set to the rotation center. And then rotating the vehicle body again until the other guide sensor detects the guideline. Method of controlling the transport vehicle. 4. The automatic guided vehicle control method according to claim 1, wherein one of the guide sensors is a guide sensor that detects a guideline relating to a new traveling direction first.