WO2009113730A1

WO2009113730A1 - Traverse position correction control device and traverse position correction control method for automated guided vehicle

Info

Publication number: WO2009113730A1
Application number: PCT/JP2009/055379
Authority: WO
Inventors: 谷本理; 多米郁雄
Original assignee: 日産自動車株式会社; 愛知機械テクノシステム株式会社
Priority date: 2008-03-14
Filing date: 2009-03-12
Publication date: 2009-09-17
Also published as: JP2009223571A; JP5130086B2

Abstract

An automated guided vehicle (1) is provided with a traverse mode in which a drive unit (11-1) provided at the front side of a vehicle and a drive unit (11-2) provided at the rear side thereof move in different tracks. The automated guided vehicle is provided with a stop judging means (S10, S20) for causing the front drive unit (11-1) and the rear drive unit (11-2) to independently judge the presence or absence of a stop command at a stop position in the traverse mode, a unit stopping means (S11, S21) for stopping the corresponding front drive unit (11-1) or rear drive unit (11-2) according to the judgment of the stop command, and a stop maintaining means (S11, S21) for maintaining the stop state of the drive unit (11-1) traveling in front in the direction of movement of the vehicle out of the front drive unit (11-1) and the rear drive unit (11-2) from when the drive unit (11-1) traveling in front stops upon receiving the stop command until the drive unit (11-2) traveling behind stops upon receiving the stop command. Thus, the manufacturing cost can be kept low without complicating the device.

Description

Description Title of Invention

Technical field of a lateral attitude correction control device and a lateral attitude correction control method for an automated guided vehicle

The present invention relates to correction control of a transverse posture of an automatic guided vehicle. Background art

Various types of self-propelled automated guided vehicles (AGV) have been proposed for the purpose of automating logistics in factories and the like. For example, JPH04-59643B issued in 1992 by the Japan Patent Office discloses an unmanned transport vehicle that runs along a track that combines straight lines and curves.

In an automated guided vehicle that travels in a transverse mode in which multiple drive units move on different tracks, the drive speed of each drive unit may differ depending on the track conditions and motor performance variations. If traversing in such a state, the posture of the automatic guided vehicle will move obliquely. And when switching from traversing mode to forward / reverse mode, there is a possibility of getting out of orbit. Therefore, in the past, a sensing device such as a rotary encoder was installed on the rotation center axis of the drive unit to detect the angular relationship between the drive unit and the vehicle body, thereby detecting the vehicle body posture so that the vehicle body posture does not collapse. I was in control. Disclosure of the invention

Problems to be solved by the invention

However, such a sensing device is expensive, and the manufacturing cost of the automatic guided vehicle increases. Accordingly, an object of the present invention is to provide a traverse posture correction control device and a traverse posture correction control method for an automatic guided vehicle that can reduce the manufacturing cost without complicating the device.

In order to achieve this object, according to the present invention, a traverse posture capture of an automatic guided vehicle having a traverse mode in which a drive unit provided on the front side of the vehicle and a drive unit provided on the rear side move on different tracks. The main control unit has stop determination means for determining whether or not there is a stop command in the stop position independently in the front drive unit and the rear drive unit in the traverse mode, and the corresponding front drive in response to the stop command. The unit stop means that stops the unit or the rear drive unit, and the drive unit that precedes the moving direction of the vehicle among the front drive unit and the rear drive unit receives a stop command. And a stop maintaining means for maintaining the stop state of the preceding drive unit until the subsequent drive unit is stopped in response to the stop command after the stop. The invention's effect

In this way, the drive unit that precedes the moving direction of the vehicle in the front drive unit and the rear drive unit receives the stop command and stops, and the subsequent drive unit issues a stop command. The stopping state of the preceding drive unit is maintained until the stop is received, so that the lateral posture of the automatic guided vehicle can be corrected and controlled without using an expensive sensing device such as a rotary encoder. Brief Description of Drawings

FIGs. 1A and IB are diagrams showing an example of an automatic guided vehicle to which the present invention is applied.

FIGS. 2A and 2B are diagrams showing the state of the drive unit when the automated guided vehicle travels.

FIG. 3 is a flowchart of the transverse posture correction control. FIGS. 4A-4D are diagrams for explaining the traveling state of the automated guided vehicle (drive unit) when the transverse posture correction control is executed, in the case where a temporary stop marker is detected.

FIGs. 5A-5D are diagrams for explaining the running state of the automated guided vehicle (drive unit) when the transverse posture correction control is executed, in the case where a stop marker is detected. BEST MODE FOR CARRYING OUT THE INVENTION

The best mode for carrying out the present invention will be described below with reference to the drawings.

FIGS. 1A and 1B are diagrams showing an example of an automatic guided vehicle to which the present invention is applied. FIG. 1 A is a side view and FIG. I B is a perspective view of a drive unit from above.

Two drive units (first drive unit 1 1 1 1, second drive unit 1 1-2) and four casters 12 are arranged at the lower part of the vehicle body 10. The first drive unit 1 1-1 and the second drive unit 1 1-2 basically have the same structure. Therefore, when there is no need to distinguish between them, it will be explained as the drive unit 11.

The drive unit 11 includes a drive wheel 1 1 a, a trajectory detection sensor l i b, and a marker detection sensor 1 1 c.

Each drive wheel 1 1 a is connected to an individual drive motor. If the two left and right drive wheels 1 1 a rotate in the same direction, they move forward or backward. If there is a difference in the rotation speed, the car will run on a curve. If the two drive wheels 1 1 a rotate in opposite directions, they can turn around the support shaft l i d and change direction.

The track detection sensor 1 1 b detects a track laid on the floor surface. The orbit detection sensor 1 1 b is, for example, a magnetic sensor. In this embodiment, three orbit detection sensors 1 1 b are arranged on the front side and the rear side of the drive unit 11. The drive unit 1 1 travels so that the track is always detected by the track detection sensor 1 lb.

The marker detection sensor 1 1 c detects the force laid near the track. The force detection sensor 1 1 c is, for example, a magnetic sensor. First drive unit on the forward direction side 1 The marker detection sensor 1 1 c-1 provided in 1-1 is disposed behind the first drive unit 1 1-1 and outside the orbit detection sensor 1 1 b. Marker detection sensor 1 1 c 1 1 detects the force in the normal forward / reverse mode and transverse mode. Marker detection sensor 1

1 c 1 1 can detect a marker for commands such as speed switching and driving mode switching, and a command marker for stopping Z pause. The marker detection sensor 1 1 c 1 2 provided in the second drive unit 1 1-2 on the rear side is located in front of the second drive unit 1 1 1 2 and outside the trajectory detection sensor 1 1 b. Has been. Marker detection sensor 1 1 c 1 2 detects the marker in the transverse mode and does not detect the marker in the normal forward / reverse mode. The force detection sensor 1 1 c-2 can detect a command marker such as stop / pause, but does not detect commands such as speed switching or driving mode switching.

The casters 1 and 2 support the weight of the vehicle and change direction following the moving direction of the vehicle.

FIGS. 2A and 2B are diagrams showing the driving modes of the automatic guided vehicle, FIG. 2A is a forward / reverse mode, and FIG. 2B is a transverse mode.

In the forward / reverse mode, the drive wheels 1 1 a of the first drive unit 11-1 and the second drive unit 11-1 are parallel to the vehicle body 10. In the forward / reverse mode, the vehicle travels along one track 20 of the first drive unit 1 1 1 1 and the second drive unit 1 1 1 2 force. The trajectory detection sensor 1 1 b in the forward direction detects the trajectory 20 laid on the floor. In FIGs. 2A and 2B, the active sensor is painted black.

In the transverse mode, the drive wheels 1 1 a of the first drive unit 11-1 and the second drive unit 11-1 are orthogonal to the vehicle body 10. In traverse mode, the first drive unit 1 1 1 1 and the second drive unit 1 1–2 travel along different tracks. That is, the first drive unit 1 1 1 1 travels along the track 2 0-1. Second drive unit 1 1− 2 travels along track 2 0 -2.

Here, the points will be described so that the present embodiment can be easily understood. In the conventional system, the automated guided vehicle travels in the transverse mode in which multiple drive units move on different tracks. When driving, the driving speed of each drive unit may differ depending on the track conditions and motor performance variations. If traversing in such a state, the vehicle body of the automated guided vehicle will move while tilting. And when switching from traversing mode to forward / reverse mode, there is a possibility of getting out of orbit. Therefore, conventionally, by detecting the angular relationship between the drive unit and the vehicle body using a rotary encoder provided on the rotation center shaft of the drive unit, each vehicle body posture is detected so that the vehicle body posture does not collapse. The speed of the drive unit was controlled. However, such a method is costly because a rotary encoder is required.

Therefore, the inventors of the present invention laid a pause / stop marker in the middle of the traverse track at a position that is simultaneously detected by each drive unit if the vehicle body posture has not collapsed. Then, only the drive unit that read this force was stopped, and the stop state of the stopped drive unit was maintained until all the drive units stopped. The inventors of the present invention have conceived of correcting the transverse posture of the automatic guided vehicle by such a simple method. In the following, a specific device Z method for realizing such a technical idea will be described.

'FIG. 3 is a flowchart of the transverse posture correction control.

The controller repeatedly executes the following processing every minute time (for example, 10 milliseconds) during the traversing mode.

In step S 10, the controller determines whether or not the marker detection sensor 1 1 c-1 of the first driving unit has detected a command marker such as stop Z-stop. Until the detection, the controller shifts the processing to step S 20. If detected, the controller proceeds to step S 1 1.

In step S 1 1, the controller stops the first drive unit 1 1 — 1. In step S12, the controller increments the first drive unit stop timer t1. In step SI3, the controller determines whether or not the first drive unit stop timer t1 has passed a predetermined time t0. Until that time, the controller

2 Moves the process to 0. When the time has elapsed, the controller shifts the processing to step S40.

In step S 20, the controller determines whether or not the marker detection sensor 1 1 c-2 of the second drive unit has detected a command force such as stop Z-time stop. Until the detection, the controller shifts the processing to step S 30. If detected, the controller proceeds to step S 21.

In step S 21, the controller stops the second drive unit 1 1− 2. In step S 22, the controller increments the second drive unit stop timer t 2.

In step S 23, the controller determines whether or not the second drive unit stop timer t 2 has passed a predetermined time t 0. Until that time, the controller

3 Moves the process to 0. When the time has elapsed, the controller shifts the processing to step S40.

In step S 30, the controller determines whether or not all the drive units (first drive unit 1 1 1 1 and second drive unit 1 1-2) have stopped. Until it stops, the controller once exits the process. When stopped, the controller proceeds to step S 3 1.

In step S 31, the controller determines that the traverse posture correction has been completed. In response to this determination, the drive unit executes the next command.

In step S40, the controller determines an error. Upon receiving this determination, the drive unit executes error processing.

FIGS. 4A-4D are diagrams for explaining the traveling state of the automated guided vehicle (drive unit) when the transverse posture correction control is executed, in the case where a temporary stop marker is detected. In the following, To make it easy to understand the correspondence with the above flow chart, add a S to the step number in the flowchart.

During traversing mode, as shown in FIG. 4A, the first drive unit 1 1- 1 and the second drive unit 1 1- 2 are always connected to the track 20-1 and 20-2 by the track detection sensor lib. While detecting, traverse to the right in the figure. At this time, in the flowchart of FIG. 3, steps S 1 0 → S 2 0 → S 3 0 are repeatedly processed. In Fig.4A, there is a difference in the traveling speed between the 1st drive cue 1 1 1 1 and the 2nd drive unit 1 1− 2 for some reason. Has moved.

When the marker detection sensor 1 1 c-1 in the first drive unit 1 1— 1 detects the pause marker 2 1-1 (Yes in S 1 0), the first drive unit 1 1 1 1 stops. (S 1 1) and the first drive unit stop timer tl is incremented (S 1 2). At this time, in the flowchart of FIG. G.3, steps S 1 0 → S 1 1 → S 1 2 → S 1 3—S 2 0 → S 3 0 are repeatedly processed. Note that the marker detection sensor 1 1 c 1 2 of the second drive unit 1 1-2 does not detect the pause marker 2 1-2, so the second drive unit 1 1-2 proceeds. As the 1st drive unit 1 1-1 stops and the 2nd drive unit 1 1 1 2 proceeds, the traverse posture is gradually corrected as shown in FIG. 4B. Although the exact illustration is omitted, there is room in the trajectory, and as the traverse posture is corrected, the 1st drive unit 1 1- 1 and the 2nd drive unit 1 1-2 are It gradually shifts to the outside. When the second drive unit 1 1 1 2 marker detection sensor 1 1 c-2 detects the pause marker 2 1-2 (Yes in S 2 0), the 2nd drive unit 1 1 1 2 stops (S 2 1). Then, the traverse posture is corrected as shown in FIG. 4C. At this time, in the broaching gear of FIG. 3, step S 1 0 → S 1 1 → S 1 2 → S 1 3 → S 20 ~ → S 2 1 → S 2 2 → S 2 3 → S 3 0 → S 3 1 And processed.

If the traversing posture correction is completed in the next step after receiving the traverse posture correction completion determination in step S31, the traversing posture can be traversed in the corrected posture as in FIG. 4D. FIGS. 5A-5D are diagrams for explaining the traveling state of the automated guided vehicle (drive unit) when the transverse posture correction control is executed, in the case where a stop marker is detected.

During traverse mode, as shown in FIG. 5A, the 1st drive unit 1 1 1 1 and the 2nd drive unit 1 1 1 2 use the orbit detection sensor 1 1 b to change the orbit 20—1, 20-2 While detecting constantly, traverse to the right in the figure. At this time, in the flowchart of FIG. 3, steps S 1 0 → S 2 0 → S 3 0 are repeatedly processed. In FIG. 5A, there is a difference in the traveling speed between the 1st drive unit 1 1 1 1 and the 2nd drive unit 1 1—2 for some reason. ing.

When the marker detection sensor 1 1 c-1 in the first drive unit 1 1— 1 detects the stopping force 2 2 1 1 (Yes in S 1 0), the first drive unit 1 1— 1 Stop (S 1 1 First drive unit stop timer t 1 is incremented (SI 2). At this time, in the flowchart of FIG. 3, step S 1 0 → S 1 1-→ S 1 2 → S 1 3 → S 20 → S 3 0 is repeatedly processed Note that the marker detection sensor 1 1 c 1 2 of the second drive unit 1 1-2 is not detecting the stop marker 2 2-2. Drive unit 1 1 1 2 advances 1st drive unit 1 1—1 stops and 2nd drive unit 1 1 1 2 advances, so the traverse posture gradually increases as shown in FIG. 5B It is corrected to.

Then, when the second drive unit 1 1−2's force detection sensor 1 1 c− 2 detects the stop marker 2 2 1 2 (Yes in S20), the 2nd drive unit 1 1 1 2 stops. (S 2 1). Then the traverse posture is corrected as shown in FIG. 5C. At this time, in the flow chart of FIG. 3, step S 1 0—S 1 1 → S 1 2 → S 1 3 → S 2 0—S 2 1 → S 2 2 → S 2 3 → S 3 0 → S 3 Processed as 1.

Then, in response to the traverse posture correction completion determination in step S 3 1, if the direction of the first drive unit 1 1-1 and the second drive unit 1 1 1 2 are changed in the following steps, the trajectory will be It is possible to switch to the forward / reverse mode without deviating from the above.

As described above, according to this embodiment, a pause Z stop marker is laid in the middle of a traverse trajectory. did. Then, only the drive unit that read this marker is stopped, and the stop state of the stopped drive unit is maintained until all the drive units stop. By correcting the traversing posture of the automated guided vehicle using such a simple method, expensive sensing equipment such as a rotary encoder is no longer necessary, and manufacturing costs can be reduced.

The present invention is not limited to the embodiments described above, and various modifications and changes can be made within the scope of the technical idea, and it is obvious that these are also included in the technical scope of the present invention.

Regarding the above explanation, Japanese patent application 2008-6667 in Japan, filed March 14, 2008

The contents of 4 are incorporated herein by reference.

Claims

Claim scope Claim 1

In the automatic guided vehicle (1) having a traverse mode in which the driving unit (11-1) provided on the front side of the vehicle and the driving unit (11-2) provided on the rear side move on different tracks. A transverse posture correction control device,

Stop determination means (S 1 0, S 1) that determines whether the front drive unit (1 1 1 1) and the rear drive unit (1 1-2) independently have a stop command at the stop position in traverse mode 2)) and the unit stop means (S11, S1) that stops the corresponding front drive unit (1 1-1) or rear drive unit (1 1 1 2) in response to the stop command. 2 1) and

Of the front drive unit (1 1 1 1) and the rear drive unit (1 1-2), the drive unit (1 1 1 1) that precedes the moving direction of the vehicle receives a stop command. The stop maintenance means (S 1 1) maintains the stop state of the preceding drive unit (1 1– 1) until the subsequent drive unit (1 1 1 2) receives a stop command and stops. , S 2 1) and

A traverse posture correction control device for an automatic guided vehicle having: Claim 2

In the automatic posture correction control device of the automatic guided vehicle described in claim 1,

It has correction completion judging means (S 3 1) for judging the completion of the correction of the traverse posture when the following drive unit (11-2) receives the stop command and stops. Claim 3

In the transverse posture correction control device of the automatic guided vehicle according to claim 2,

Stop time measuring means (S 1 2) for measuring the elapsed time from when the preceding drive unit (1 1 1 1) stopped in response to the stop command; And an error determination means (S 40) for determining an error when it is not possible to determine the correction of the traverse posture correction even if the elapsed time measured by the stop time measurement means (S 12) exceeds a predetermined time. Claim 4

In the transverse posture correction control device for an automatic guided vehicle according to any one of claims 1 to 3,

Stop determination means (S 1 0, S 2 0) are detected by magnetic sensors (1 lc 1, 1 1 c 1 2) installed in each drive unit (1 1 1 1, 1 1 1 2). Determine if there is a stop command. Claim 5

The automatic guided vehicle (1) having a traverse mode in which the driving unit (1 1-1) provided on the front side of the vehicle and the driving unit (1 1-2) provided on the rear side move on different tracks. A transverse posture correction control method,

Stop determination process (S 1 0) where the front drive unit (1 1–1) and the rear drive unit (1 1–2) independently determine the presence or absence of a stop command in the traverse mode. , S 2 0) and a stop command to stop the corresponding front drive unit (1 1 1 1) or rear drive unit (1 1 1 2) by determining the stop command (S 1 1 , S 2 1) and

Of the front drive unit (1 1 1 1) and the rear drive unit (1 1 1 1 2), the drive unit (1 1 1 1) that precedes the moving direction of the vehicle receives a stop command. The stop maintenance process (S 1 1) maintains the stop state of the preceding drive unit (1 1— 1) until the subsequent drive unit (1 1 1 2) receives a stop command and stops. , S 2 1),

A lateral posture correction control method for an automatic guided vehicle having Claim 6 6. A method of determining completion of correction of the transverse posture of the automatic guided vehicle according to claim 5, wherein when the following drive mute (11 1 2) receives a stop command and stops, the correction of the transverse posture is completed. (S 3 1).