Unmanned conveyance vehicle system and unmanned conveyance vehicle

Abstract

To transfer an article from a conveyor to an unmanned conveyance vehicle while causing the unmanned conveyance vehicle to travel along the conveyor.SOLUTION: In an unmanned conveyance vehicle 10, a control unit 74 is configured to: control travel drive motors 33, 45, 55, 56 to cause the unmanned conveyance vehicle 10 to travel along a conveyor device 11A at a travel speed greater than a speed at which an article is conveyed; cause an arm 42 on the upstream side in the conveying direction to project into a space above the conveyor device 11A; upon the upstream-side arm 42 catching up with the article, cause an arm 42 on the downstream side in the conveying direction to project, thereby sandwiching the article between the arms 42; cause respective claw parts 51 to project from tip-end sides of the respective arms 42; cause the arms 42 to be drawn into the unmanned conveyance vehicle 10 so that the claw parts 51 hook on the article; and transfer the article to the unmanned conveyance vehicle 10.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to an automated guided vehicle system for running an automated guided vehicle and the automated guided vehicle, and particularly to a technique for transferring an article from a conveyor to the automated guided vehicle while running the automated guided vehicle along the conveyor.

Background Art

[0002] In recent years, various systems for transporting articles by an automated guided vehicle (AGV) have been proposed. For example, in the automated transportation system described in Patent Document 1, a conveyor is used to transport a load. When the load arrives at the end of the conveyor, a nearby automated guided vehicle is called, and a robot mounts the load on the automated guided vehicle. Then, the automated guided vehicle transports the load to a shelf and stores the load on the shelf.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when a load is transported by a conveyor as in Patent Document 1 and the load is mounted on an automated guided vehicle by a robot after the load arrives at the end of the conveyor, the time from the start of transporting the load by the conveyor to the mounting of the load on the automated guided vehicle becomes long, and the load is not efficiently moved.

[0005] In addition, as a robot for mounting a load on an automated guided vehicle, the application of an arm robot or the like is assumed. However, when such a robot is applied, the configuration of the system may become complicated and the cost of the system may increase.

[0006] The present invention has been made in view of the above circumstances, and an object thereof is to enable the transfer of an article from a conveyor to an unmanned transport vehicle while the unmanned transport vehicle travels along the conveyor with a simple configuration, and to efficiently move the article.

Means for Solving the Problems

[0007] An unmanned transport vehicle system according to an aspect of the present invention includes a conveyor for loading and transporting an article, and an unmanned transport vehicle that travels along the conveyor. The unmanned transport vehicle rotates drive wheels of the unmanned transport vehicle to travel the unmanned transport vehicle, and when the unmanned transport vehicle travels along the conveyor, is provided at respective positions on the unmanned transport vehicle that are downstream and upstream in the transport direction of the article by the conveyor, extends in a direction orthogonal to the transport direction of the article, and faces each other at a position spaced apart by a distance corresponding to the width of the article in the transport direction of the article by the conveyor. A pair of arms that reciprocate in the orthogonal direction to project outward from the unmanned transport vehicle and are drawn into the unmanned transport vehicle from the projected position, an arm drive unit that causes each arm to reciprocate in the orthogonal direction, and provided at the tip side of the pair of arms, protruding from the arm portion at the tip side into the space between the arms, and respectively retracting into the interior of the arm portion. First claw portions, a first claw drive unit that causes each first claw portion to perform the projecting and retracting operations, and controls the traveling drive unit, the arm drive unit, and the first claw drive unit to move the unmanned transport vehicle along the conveyor at a traveling speed higher than the transport speed of the article, and causes the arm provided on the upstream side to project above the conveyor from the unmanned transport vehicle. When the arm provided on the upstream side in the transport direction moves to the position of the article being transported by the conveyor, the arm provided on the downstream side is caused to project above the conveyor from the unmanned transport vehicle, and with the article present between the arms, after causing each first claw portion to project from the tip side of each arm into the space between the arms, a control unit that causes each arm to be drawn into the unmanned transport vehicle from above the conveyor.

[0008] Also, an unmanned transport vehicle according to an aspect of the present invention is an unmanned transport vehicle that travels along a conveyor for loading and transporting articles, and includes a traveling drive unit that rotates drive wheels of the unmanned transport vehicle to cause the unmanned transport vehicle to travel, and a pair of arms provided at respective positions on the unmanned transport vehicle that are on the downstream side and the upstream side in the transport direction of the articles by the conveyor when the unmanned transport vehicle travels along the conveyor, extending in a direction orthogonal to the transport direction of the articles, facing each other at a position corresponding to the width of the articles in the transport direction of the articles by the conveyor, reciprocating in the orthogonal direction to project outward from the unmanned transport vehicle, and being retracted into the unmanned transport vehicle from the projected position; an arm drive unit that causes the respective arms to reciprocate in the orthogonal direction; first claw portions provided at the tip ends of the pair of arms, projecting from the arm portions at the tip ends into the space between the respective arms, and retracting into the inside of the arm portions; a first claw drive unit that causes the respective first claw portions to perform the projecting and retracting operations; and a control unit that controls the traveling drive unit, the arm drive unit, and the first claw drive unit to cause the unmanned transport vehicle to travel along the conveyor at a traveling speed higher than the transport speed of the articles, project the arm provided on the upstream side from the unmanned transport vehicle above the conveyor, project the arm provided on the downstream side from the unmanned transport vehicle above the conveyor when the arm provided on the upstream side in the transport direction has moved to the position of the articles being transported by the conveyor, project the respective first claw portions from the tip ends of the respective arms into the space between the respective arms with the articles present between the respective arms, and then retract the respective arms from above the conveyor into the unmanned transport vehicle.

Advantages of the Invention

[0009] According to the present invention, with a simple configuration, it is possible to transfer articles from a conveyor to an unmanned transport vehicle while causing the unmanned transport vehicle to travel along the conveyor, and the articles can be efficiently moved.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

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Figure 6

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Figure 8

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Figure 10

Figure 11

Figure 12

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Figure 15

Figure 16

Figure 17

Mode for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0012] FIG. 1 is a schematic view showing an unmanned transport vehicle system according to an embodiment of the present invention. The unmanned transport vehicle system Sy shown in FIG. 1 includes an unmanned transport vehicle 10 and a conveyor device 11 for transporting articles. The unmanned transport vehicle system Sy is provided indoors in a warehouse or the like having a storage shelf 12.

[0013] The unmanned transport vehicle 10 travels automatically along a travel line 15 laid on the floor surface. For example, the travel line 15 is a magnetic tape attached to the floor surface, and the unmanned transport vehicle 10 is provided with a magnetic sensor for detecting the magnetic tape. In the unmanned transport vehicle 10, the position of the magnetic tape (travel line 15) is detected by the magnetic sensor, and steering control is performed according to the position of the travel line 15 to cause the unmanned transport vehicle 10 to travel along the travel line 15. Alternatively, the travel line 15 is a color tape having a color or reflectance different from that of the floor surface attached to the floor surface, and the unmanned transport vehicle 10 is provided with an optical sensor such as a CCD for detecting the color tape. Unmanned transport vehicle In 10, a control unit (described later) detects the position of the color tape (travel line 15) based on information obtained from an optical sensor, and performs steering control according to the position of the travel line 15 to cause the unmanned transport vehicle 10 to travel along the travel line 15. Both the method using such a magnetic tape and a magnetic sensor and the method using a color tape and an optical sensor are known technologies.

[0014] The conveyor device 11 includes a first conveyor 11A and a second conveyor 11B connected to one end of the first conveyor 11A. Both the first conveyor 11A and the second conveyor 11B are formed by arranging a plurality of rollers 16 in parallel in the conveying direction of the case CS (an example of an article). Each roller 16 is pivotally supported on the frames of the first conveyor 11A and the second conveyor 11B by respective axes orthogonal to the conveying direction of the case CS, and is rotationally driven in one direction to convey the case CS on each of these rollers 16. Note that a belt conveyor may be applied as the first conveyor 11A and the second conveyor 11B.

[0015] The travel line 15 is formed by connecting a first travel line 15A, a second travel line 15B, a third travel line 15C, and a fourth travel line 15D in a rectangular shape. Each of the travel lines 15A to 15D is linear. The first travel line 15A extends parallel to the extending direction of the first conveyor 11A (the direction in which the case CS is conveyed). The fourth travel line 15D passes near the storage shelf 12.

[0016] The automated guided vehicle 10 starts running from a standby position HP provided near the start end of the first running line 15A, runs parallel to the first conveyor 11A along the first running line 15A, and at the end of the first running line 15A, changes the traveling direction by 90 degrees and shifts to running along the second running line 15B. The automated guided vehicle 10 further changes the traveling direction by 90 degrees at the end of the second running line 15B and shifts to running along the third running line 15C. The automated guided vehicle 10 runs along the third running line 15C to reach the storage shelf 12, and then, at the end of the third running line 15C, changes the traveling direction by 90 degrees and shifts to running along the fourth running line 15D. The automated guided vehicle 10 further changes the traveling direction by 90 degrees at the end of the fourth running line 15D and shifts to running along the first running line 15A, and returns to the standby position HP near the start end of the first running line 15A.

[0017] FIG. 2 is a perspective view schematically showing the automated guided vehicle 10 in an enlarged manner. As shown in FIG. 2, the automated guided vehicle 10 is configured by providing a running part 22 on the lower side of the vehicle body and a working part 23 on the upper side of the vehicle body.

[0018] At the four corners of the bottom of the running part 22, respective casters 31 are provided, and a plurality of drive wheels 32 are provided at intervals inside the bottom of the running part 22. Each drive wheel 32 is rotationally driven by a respective running drive motor 33, the automated guided vehicle 10 runs, and the wheels of each caster 31 rotate passively. Also, for each drive wheel 32, the running drive motor 33 that rotationally drives the drive wheel 32 is controlled, the rotational speed of each drive wheel 32 is adjusted, and the traveling direction of the automated guided vehicle 10 is changed. In FIG. 2, the illustration of the mechanism including the drive source of each drive wheel 32 is omitted.

[0019] In the working section 23, a pair of support walls 41 are oppositely arranged and protrude from the upper surface thereof. Each support wall 41 supports the arm 42 at its upper part and outer side wall. Each arm 42 is, for example, in the shape of a hollow housing, and is supported by each support wall 41 so as to be slidable along each support wall 41 via a slide rail 43. The separation distance between each pair of arms 42 is set to a predetermined distance slightly longer than the width of the case CS conveyed by the conveyor device 11, and the case CS can be inserted and sandwiched between each pair of arms 42.

[0020] FIG. 3 is a perspective view showing the sliding state of each arm 42. Each of the arms 42 is supported by two slide rails 43 extending in the horizontal direction so as to be slidable with respect to each support wall 41 and the moving direction is guided, and each arm 42 reciprocates in its longitudinal direction. Each slide rail 43 has a configuration called, for example, a three-stage draw, and a part thereof protrudes and moves outward toward the side of the working section 23. The slide rail 43 has a first rail forming a part thereof provided on the side wall of the support wall 41, and a second rail that is locked and supported by the first rail and whose moving direction is guided by the first rail to move to the outside on the side of the working section 23. This second rail is attached to the arm 42. Thereby, each arm 42 reciprocates in the horizontal direction, and the whole of each arm 42 can perform an operation of protruding outward from the automated guided vehicle 10 and being drawn into the automated guided vehicle 10 from the protruding position.

[0021] For each arm 42, as shown in FIG. 4, a rack gear 44 is provided at the lower end of the arm 42. Further, each support wall 41 is provided with a respective arm drive motor 45 (shown in FIG. 6), and a respective pinion gear 46 is fixed to the output shaft of each arm drive motor 45. When each arm drive motor 45 rotates back and forth, each pinion gear 46 rotates back and forth, and each rack gear 44 and each arm 42 are reciprocally moved while being guided in the moving direction by the slide rail 43. Note that the outward movement of the arm 42 in the moving direction is limited, as shown in FIG. 3, by the engagement of the first rail and the second rail of the slide rail 43 and the rotation control of the arm drive motor 45 to a position where the locking and support of the arm 42 by the support wall 41 and the slide rail 43 are not released.

[0022] Also, as shown in FIGS. 2 and 3, for each arm 42, a slit 42A is formed in the side surface portion on the inner side (the side facing the other arm 42) of the tip of the arm 42, and a first claw portion 51 protruding into the space between the arms 42 through the slit 42A is provided. Further, a slit 42B is formed in the side surface portion on the inner side (the side facing the other arm 42) of the rear end (base end) of the arm 42, and a second claw portion 52 protruding into the space between the arms 42 through the slit 42B is provided.

[0023] As shown in FIG. 5, each first claw portion 51 is supported by a rotation shaft 53 inside the hollow housing-shaped arm 42, and each second claw portion 52 is supported by a rotation shaft 54 inside the hollow housing-shaped arm 42. Each first claw portion 51 is reciprocally rotated by a claw drive motor 55 (shown in FIG. 6) connected to each rotation shaft 53 to perform an operation of protruding into the space between the arms 42 from the slit 42A and an operation of moving out of the space and retracting into the arm 42. Each second claw portion 52 is reciprocally rotated by a claw drive motor 56 (shown in FIG. 6) connected to each rotation shaft 54 to perform an operation of protruding into the space between the arms 42 from the slit 42B and an operation of moving out of the space and retracting into the arm 42.

[0024] As shown in FIGS. 2 and 3, an imaging camera 71 made of, for example, a CCD or the like is provided above the working unit 23. When the unmanned transport vehicle 10 travels along the first travel line 15A in parallel with the first conveyor 11A, the orientation of the imaging camera 71 is set so that the imaging camera 71 faces the space above the first conveyor 11A. In the present embodiment, this imaging camera 71 is disposed at the center in the traveling direction of the unmanned transport vehicle 10 in the region sandwiched between the two support walls 41 on the working unit 23 and on the base end side of each arm 42. The imaging camera 71 images a two-dimensional code (for example, a QR code (registered trademark)) Q or a mark attached to the case CS conveyed on the first conveyor 11A. Note that the imaging camera 71 may be disposed at a position outside one of the support walls 41 on the working unit 23 (outside the region sandwiched between the two support walls 41) in the traveling direction of the unmanned transport vehicle 10 on the base end side of each arm 42, or at a position on the upper part of one of the support walls 41 and on the side wall side facing the other support wall 41. Further, the imaging camera 71 may be disposed at other positions as long as it can image the two-dimensional code Q or the mark attached to the case CS conveyed on the first conveyor 11A even at a position that is not the base end side of each arm 42.

[0025] FIG. 6 is a block diagram showing a control system of the unmanned transport vehicle 10. As shown in FIG. 6, the unmanned transport vehicle 10 includes respective traveling drive motors 33 that rotationally drive the drive wheels 32 of the traveling unit 22, respective arm drive motors 45 that horizontally move the arms 42 of the working unit 23, respective claw drive motors 55 that cause each first claw portion 51 to perform an operation of protruding from the slits 42A inside both ends of each arm 42 into the space between the arms 42 and an operation of retracting into the arm 42, respective claw drive motors 56 that cause each second claw portion 52 to perform an operation of protruding from the slits 42B inside both ends of each arm 42 into the space between the arms 42 and an operation of retracting into the arm 42, an imaging camera 71 that images the two-dimensional code Q attached to the case CS on the first conveyor 11A, a traveling line sensor 72 that detects the traveling line 15, a communication unit 73, and a control unit 74.

[0026] The communication unit 73 is a communication interface including a communication module such as a LAN chip (not shown), and is connected to the terminal device 81 through a wired or wireless LAN to transmit and receive data with the terminal device 81. The terminal device 81 is, for example, a PC (Personal Computer) and is operated by a user.

[0027] The control unit 74 is configured to include a processor, a RAM (Random Access Memory), a ROM (Read Only Memory), and a dedicated hardware circuit. The processor is, for example, a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), or an MPU (Micro Processing Unit), etc. The control unit 74 comprehensively controls the unmanned transport vehicle 10 by the operation of the processor according to the control program stored in the above ROM.

[0028] For example, the control unit 74 detects the position of the travel line 15 based on the detection output of the travel line sensor 72, and according to the detected position of the travel line 15, for each drive wheel 32, drives and controls the travel drive motor 33 of the drive wheel 32 to adjust the rotation speed of the drive wheel 32, changes the traveling direction of the unmanned transport vehicle 10, and performs operation control to make the unmanned transport vehicle 10 travel along the travel line 15 with the longitudinal direction of each arm 42 orthogonal to the travel line 15. In addition, the control unit 74 adjusts the traveling speed V of the unmanned transport vehicle 10.

[0029] In addition, the control unit 74 drives and controls each arm drive motor 45 to reciprocate each arm 42, and drives and controls each claw drive motor 55, 56 to cause each claw portion 51, 52 to protrude from or retract into the respective slits 42A, 42B formed at both ends of each arm 42.

[0030] Furthermore, the control unit 74 acquires the image captured by the imaging camera 71, analyzes the image, and identifies the two-dimensional code Q included in the image.

[0031] The automated guided vehicle 10 configured as described above stops and waits at the standby position HP under the control of the control unit 74. When the conveyance of the case CS is started by the first conveyor 11A, the vehicle travels parallel to the first conveyor 11A along the first travel line 15A while driving each arm 42 to transfer the case CS being conveyed by the first conveyor 11A to the automated guided vehicle 10. Further, under the control of the control unit 74, the automated guided vehicle 10 travels along the route of the first travel line 15A → the second travel line 15B → the third travel line 15C, moves to the front of the storage shelf 12, stops, transfers the case CS to the storage shelf 12, and then travels along the route of the third travel line 15C → the fourth travel line 15D → the first travel line 15A to return to the standby position HP.

[0032] Next, a control procedure for transferring the case CS being conveyed by the first conveyor 11A to the automated guided vehicle 10 as described above and moving the case CS by the automated guided vehicle 10 will be described in detail with reference to the flowchart shown in FIG. 7 and the like.

[0033] As shown in FIG. 1, with the automated guided vehicle 10 waiting at the standby position HP on the first travel line 15A, the conveyance of the case CS is started by the second conveyor 11B. The standby position HP is set at the side of the end of the second conveyor 11B and the position connecting to the first conveyor 11A (the start end of the first conveyor 11A). The case CS on the second conveyor 11B is conveyed in a posture where the attached two-dimensional code Q faces the standby position HP. The case CS conveyed to the position indicated by the dashed line in FIG. 1 is subsequently conveyed by the first conveyor 11A while switching the conveyance direction in the direction of the arrow shown in FIG. 1.

[0034] When the unmanned transport vehicle 10 is in the standby position HP and the case CS has been transported to the position indicated by the dashed line in FIG. 1, the imaging camera 71 captures the two-dimensional code Q on the case CS. The imaging camera 71 of the unmanned transport vehicle 10 in the standby position HP is provided at a position facing the two-dimensional code Q on the side surface of the case CS. The two-dimensional code Q contains identification information indicating the ID unique to the case CS. In the unmanned transport vehicle 10, the control unit 74 analyzes the two-dimensional code Q captured by the imaging camera 71 and determines whether the ID indicated by the identification information is the same as the ID indicated by the identification information received in advance from the terminal device 81 via the communication unit 73.

[0035] In the unmanned transport vehicle 10, when the control unit 74 determines that they are the same, it starts the unmanned transport vehicle 10 to travel in the direction of the arrow shown in FIG. 1 (S101). At this time, it is assumed that the case CS has already passed through the position indicated by the dashed line in FIG. 1, that is, the standby position HP, without changing its posture, and the conveyance by the first conveyor 11A has started.

[0036] The control unit 74 detects the position of the travel line 15 based on the detection output of the travel line sensor 72, and in accordance with the detected position of the travel line 15, drives and controls the travel drive motors 33 of the respective drive wheels 32, so that, as shown in FIG. 8(A), the unmanned transport vehicle 10 is in a posture where the extending direction (longitudinal direction of the arm 42) of each arm 42 is orthogonal to the travel line 15, and the unmanned transport vehicle 10 travels along the first travel line 15A in a position close to and parallel to the first conveyor 11A (S102). At this time, the control unit 74 sets the travel speed V of the unmanned transport vehicle 10 to a predetermined travel speed VA that is faster than the conveyance speed VC of the case CS by the first conveyor 11A (S102).

[0037] Also, the control unit 74 drives and controls one of the respective arm drive motors 45 to project one of the arms 42 on the upstream side in the conveyance direction of the case CS into the space above the first conveyor 11A, as shown in FIG. 8(B) (S103).

[0038] At this time, since the control unit 74 sets the traveling speed V of the driverless transport vehicle 10 to the above-mentioned traveling speed VA that is faster than the transport speed VC of the case CS by the first conveyor 11A, as shown in FIGS. 8(B) and 9, one of the arms 42 on the upstream side in the transport direction of the case CS, which protrudes into the space above the first conveyor 11A, catches up with and contacts the case CS.

[0039] In addition, on the side surface of the case CS facing the driverless transport vehicle 10, a predetermined mark (such as a hole formed on the side surface, or a predetermined printed image, etc. A two-dimensional code Q may also be used) is provided. Since the imaging camera 71 is provided at a position where it can image the side surface of the case CS when the one arm 42 catches up with and contacts the case CS, when the one arm 42 catches up with and contacts the case CS, the mark is imaged by the imaging camera 71.

[0040] The control unit 74 acquires the image captured by the imaging camera 71, analyzes this image, and when identifying the image indicating the mark in the image (S104), assuming that the one arm 42 has caught up with and contacted the case CS, it drives and controls the arm drive motor 45 for the other arm 42, and as shown in FIG. 10(A), the other arm 42 on the downstream side in the transport direction of the case CS is made to protrude into the space above the first conveyor 11A (S105). The separation distance between the respective arms 42 is set to a distance corresponding to the width of the case CS, which is slightly longer than the width of the case CS. Therefore, due to the protrusion of the other arm 42, the case CS is inserted and sandwiched between the respective arms 42. In addition, each arm 42 protruded by the control of the control unit 74 has a length such that its tip reaches a position beyond the rear end of the case CS in the direction orthogonal to the transport direction of the case CS due to this protrusion. The control unit 74 protrudes each arm 42 until the tip of each arm 42 reaches a position beyond the rear end of the case CS in this way (FIGS. 10(A) and 11). Subsequently, the control unit 74 drives and controls each claw drive motor 55 to protrude the first claw portions 51 inside the tips of the respective arms 42 as shown in FIGS. 10(B) and 11 (S106).

[0041] The two-dimensional code Q identified in S104 includes information indicating the weight of the contents contained in the case CS. This information may indicate the weight itself, or for example, may indicate the weight of each individual content and the number of contents. The control unit 74 determines the weight of the contents based on the information, and adds the known weight of the case CS to the weight of the contents to calculate the weight of the article (S107). Note that the above information may indicate the weight of the article itself obtained by adding the known weight of the case CS to the weight of the contents. In this case, the control unit 74 directly obtains the weight of the article from the information. At this point, the control unit 74 drives and controls the traveling drive motors 33 of the respective drive wheels 32 to cause the unmanned transport vehicle 10 to travel at the traveling speed VA set in S102. After S107, the control unit 74 compares the weight of the article calculated in S107 with a preset threshold value. If it is determined that the weight of the article is less than the threshold value, the control unit 74 maintains the traveling speed V of the unmanned transport vehicle 10 at the traveling speed VA.

[0042] Further, if the weight of the article is equal to or greater than the above threshold value, the control unit 74 reduces the traveling speed V of the unmanned transport vehicle 10 to a predetermined traveling speed VD that is equal to or greater than the transport speed VC of the case CS by the first conveyor 11A and slower than the traveling speed VA up to that point set in S102 (S108). Thereby, when the weight of the article contained in the case CS is equal to or greater than the threshold value and is heavy, the traveling speed V of the unmanned transport vehicle 10 is reduced while being maintained at or higher than the transport speed VC of the case CS. For this reason, when the unmanned transport vehicle 10 is traveling while pushing the case CS with the one arm 42 that has been projected, the load applied to each traveling drive motor 33 can be reduced, and the load from the case CS applied to the one arm 42 can also be reduced, so that the unmanned transport vehicle 10 can travel stably.

[0043] Furthermore, the control unit 74 sets the rotational speed of each arm drive motor 45 according to the weight of the article calculated in S107 (S109). For example, the control unit 74 sets the rotational speed of each arm drive motor 45 to be slower as the weight of the article increases. For example, a data table showing the weight of the article and the rotational speed of each corresponding arm drive motor 45 for each weight of the article is stored in a ROM built into the control unit 74. The control unit 74 reads out the rotational speed of each arm drive motor 45 corresponding to the weight of the article calculated in S107 from the data table, and sets the read rotational speed as the rotational speed of each arm drive motor 45 according to the weight of the article calculated in S107.

[0044] Then, the control unit 74 drives and controls each arm drive motor 45 to rotate each arm drive motor 45 at the rotation speed set in S108. As shown in FIG. 12, each arm 42 is retracted from the space above the first conveyor 11A and drawn into the area within the working portion 23 of the automated guided vehicle 10 from the protruding position as described above. When each arm 42 is being drawn in, each first claw portion 51 catches on the end of the case CS, and each arm 42 draws the case CS from the first conveyor 11A into the working portion 23 of the automated guided vehicle 10 (S110). That is, by the above-described drawing-in of each arm 42, the case CS moves from the position on the first conveyor 11A to the working portion 23 of the automated guided vehicle 10. As a result, as the weight of the article increases, the moving speed of each arm 42 is slowed down, and the case CS is transferred from the first conveyor 11A to the working portion 23 of the automated guided vehicle 10 at a slow speed. Therefore, when each arm 42 draws the case CS into the working portion 23 of the automated guided vehicle 10, the load applied to each arm drive motor 45 can be reduced. Further, the movement of the case CS from the position on the first conveyor 11A to the working portion 23 of the automated guided vehicle 10 is performed while the conveyance by the first conveyor 11A and the travel of the automated guided vehicle 10 continue. However, since the movement is performed at a low speed, the case CS can be stably and reliably moved from the position on the first conveyor 11A to the working portion 23 of the automated guided vehicle 10. After this, the control unit 74 drives and controls each claw drive motor 55 to retract each first claw portion 51 and store it in the arm 42.

[0045] In this way, while the automated guided vehicle 10 travels parallel to the first conveyor 11A along the first travel line 15A, the case CS being conveyed by the first conveyor 11A is transferred from the first conveyor 11A to the automated guided vehicle 10.

[0046] Furthermore, the control unit 74 detects the position of the travel line 15 based on the detection output of the travel line sensor 72, and drives and controls the travel drive motors 33 of the respective drive wheels 32 according to the detected position of the travel line 15, so that the automated guided vehicle 10 travels along a path of the first travel line 15A → the second travel line 15B → the third travel line 15C (S111).

[0047] When the automated guided vehicle 10 travels to the position of the storage shelf 12, at the storage shelf 12, the two-dimensional code Q2 attached to each different position in the traveling direction of the automated guided vehicle 10 is imaged by the imaging camera 71. The control unit 74 analyzes the imaged two-dimensional code Q2 and detects the location information of the storage shelf 12 included in the two-dimensional code Q2. The control unit 74 has received in advance the location information of the storage shelf 12 associated with the above ID via the communication unit 73. When the two-dimensional code Q2 including the location information that matches the location information of the storage shelf 12 associated with the above ID is imaged, the control unit 74 stops the automated guided vehicle 10 at this position, as shown in the example of FIG. 13 (S112). At this time, the automated guided vehicle 10 has a posture in which the tip of the arm 42 provided with each first claw portion 51 faces the storage shelf 12 side due to the direction change at each path change of the first travel line 15A → the second travel line 15B → the third travel line 15C.

[0048] Here, the control unit 74 drives and controls each claw drive motor 56 to project the second claw portion 52 inside the rear end of each arm 42 as shown in FIGS. 13 and 14 (S113). At this time, the second claw portion 52 inside the rear end of each arm 42 is located on the end side of the case CS on the side opposite to the storage shelf 12.

[0049] Subsequently, the control unit 74 drives and controls each arm drive motor 45 to project each arm 42 toward the storage shelf 12 as shown in FIGS. 15 and 16 (S114). The protruding amount at this time is set such that the second claw portion 52 inside the rear end of each arm 42 can enter at least above the storage shelf 12. The slide rail 43 is configured to move in the external direction toward the storage shelf 12 (the direction opposite to the external side toward the first conveyor 11A shown in FIG. 3) in which the moving direction is guided by the first rail due to the locking and support of the second rail by the first rail.

[0050] By protruding each arm 42 toward the storage shelf 12, each second claw portion 52 is hooked on the case CS, and the case CS is pushed into the storage shelf 12 from above the working portion 23 of the driverless transport vehicle 10 by each arm 42 and the second claw portion 52, and the case CS is moved from above the working portion 23 of the driverless transport vehicle 10 to the storage shelf 12. After that, the control unit 74 drives and controls each claw drive motor 56 to retract each second claw portion 52 and store it in the arm 42.

[0051] The control unit 74 detects the position of the travel line 15 based on the detection output of the travel line sensor 72, and in accordance with the detected position of the travel line 15, drives and controls the travel drive motors 33 of the drive wheels 32 to make the driverless transport vehicle 10 travel along the path of the third travel line 15C → the fourth travel line 15D → the first travel line 15A, and after changing the traveling direction by 90 degrees between the fourth travel line 15D and the first travel line 15A, stops the travel drive motors 33 of the drive wheels 32 after a certain time and stops the driverless transport vehicle 10 at the standby position HP (S115).

[0052] As described above, in this embodiment, when the conveyance of the case CS is started by the first conveyor 11A, the unmanned carrier vehicle 10 travels parallel to the first conveyor 11A along the first travel line 15A, and one arm 42 on the upstream side in the conveyance direction protrudes. At this time, the travel speed V of the unmanned carrier vehicle 10 is set to a travel speed VA that is faster than the conveyance speed VS of the case CS. When one arm 42 moves to the position of the case CS, the other arm 42 on the downstream side in the conveyance direction protrudes. Then, the case CS is sandwiched between the arms 42. In this state, the first claw portions 51 inside the tips of the arms 42 protrude, and the arms 42 are pulled back into the unmanned carrier vehicle 10. At this time, each first claw portion 51 catches on the case CS, and the case CS is pushed from the first conveyor 11A into the working portion 23 of the unmanned carrier vehicle 10 by the arms 42 and the first claw portions 51 and moves onto the working portion 23 of the unmanned carrier vehicle 10. Thus, according to this embodiment, while the unmanned carrier vehicle 10 is traveling, the case CS being conveyed by the first conveyor 11A can be transferred to the unmanned carrier vehicle 10, and the case CS can be efficiently moved. <Modification Example 1> In Modification Example 1, the working portion 23 of the unmanned carrier vehicle 10 moves up and down in the vertical direction. For example, a plurality of columns are projected from the traveling portion 22 of the unmanned carrier vehicle 10, and the working portion 23 is supported by each column so as to be movable in the vertical direction, and the working portion 23 is moved up and down by a plurality of ball screws (known mechanisms). The ball screw includes a screw shaft that is projected from the traveling portion 22 and rotatably supported, and a nut that is fixed to the working portion 23 and screwed onto the screw shaft. Each lifting motor for rotating each screw shaft is provided on the traveling portion 22, and under the control of the control unit 74, each lifting motor rotates each screw shaft in one direction to lift each nut and the working portion 23, and each lifting motor rotates each screw shaft in the reverse direction to lower each nut and the working portion 23. Thereby, even if the heights of the conveyor device 11 and the storage shelf 12 change, the working portion 23 can be moved up and down according to this height, and the case CS can be transferred between the working portion 23 and the conveyor device 11 or the storage shelf 12. <Modification Example 2> In the second modification, the distance between the arms 42 is changed. For example, one of the support walls 41 of the working section 23 is supported so as to be slidable in a direction orthogonal to the longitudinal direction of each arm 42. A rack gear extending in the orthogonal direction is provided at the lower end of one support wall 41, a pinion gear meshing with this rack gear is provided, and a motor for reciprocally rotating the pinion gear is provided in the working section 23. Under the control of the control section 74, the motor reciprocally rotates the pinion gear to reciprocally move the rack gear, and moves one support wall 41 and the arm 42 closer to and away from the other support wall 41 and the arm 42, thereby changing the distance between the arms 42. As a result, even if the width of the case CS changes, the case CS can be sandwiched between the arms 42 and transferred between the working section 23 and the conveyor device 11 or the storage shelf 12.

[0053] Note that the configurations and processes of the above-described embodiments described with reference to FIGS. 1 to 17 are merely one embodiment of the present invention, and the present invention is not intended to be limited to such configurations and processes. For example, in the above-described embodiment, an embodiment has been described in which the unmanned transport vehicle 10 takes in the case CS conveyed by the conveyor device 11 and stores it in the storage shelf 12. However, the control section 74 drives and controls the traveling drive motor 33, the arm drive motor 45, and the claw drive motors 55 and 56 to operate the arm 42, the first claw portion 51, the second claw portion 52, and the imaging camera 71, so that the unmanned transport vehicle 10 takes in the case CS stored in the storage shelf 12 onto the unmanned transport vehicle 10, conveys the case CS to the position of the conveyor device 11, and transfers the case CS from the unmanned transport vehicle 10 to the conveyor device 11.

Explanation of Reference Numerals

[0054] 10 Unmanned transport vehicle 11 Conveyor device 12 Storage shelf 15 Traveling line 22 Traveling section 23 Working section 31 Caster 32 Driving wheel 41 Support wall 42 Arm 43 Slide Rail 51 First Claw Portion 52 Second Claw Portion 33 Each Travel Drive Motor 45 Each Arm Drive Motor 55 Each Claw Drive Motor 56 Each Claw Drive Motor 71 Imaging Camera 72 Travel Line Sensor 73 Communication Unit 74 Control Unit Sy Automated Guided Vehicle System

Claims

1. A conveyor for carrying and transporting articles; and an unmanned guided vehicle that travels along the conveyor; The automated guided vehicle includes: a travel drive unit that rotates drive wheels of the automated guided vehicle to cause the automated guided vehicle to travel; a pair of arms which are provided at respective positions on the unmanned transport vehicle which are downstream and upstream in a direction in which the conveyor transports the article when the unmanned transport vehicle travels along the conveyor, extend in a direction perpendicular to the direction in which the article is transported, face each other at positions spaced apart by a distance corresponding to a width of the article in the direction in which the conveyor transports the article, and reciprocate in the perpendicular direction to protrude outward from the unmanned transport vehicle and are retracted into the unmanned transport vehicle from the protruding position; an arm driving unit that causes each of the arms to reciprocate in the orthogonal direction; a first claw portion provided on a tip end side of each of the pair of arms, protruding from an arm portion on the tip end side into a space between the arms and retracting into the arm portion; a first claw drive unit that causes each of the first claw portions to perform the protruding and retracting operations; and a control unit that controls the travel drive unit, the arm drive unit, and the first claw drive unit to travel the unmanned transport vehicle along the conveyor at a travel speed faster than a transport speed of the article, and to cause the arm provided on the upstream side to protrude above the conveyor from the unmanned transport vehicle, and when the arm provided on the upstream side in the transport direction moves to a position of the article being transported by the conveyor, to cause the arm provided on the downstream side to protrude above the conveyor from the unmanned transport vehicle, and with the article present between the arms, to protrude each of the first claw units from the tip side of each arm into the space between the arms, and then to retract each of the arms from above the conveyor into the unmanned transport vehicle.

2. A predetermined mark is provided at a predetermined location on the article; The automated guided vehicles further include an imaging unit that images a space above the conveyor, 2. The automated guided vehicle system according to claim 1, wherein the control unit determines that the arm provided on the upstream side has moved to the position of the item being transported by the conveyor when the control unit determines, through analysis of an image captured by the imaging unit, that the image includes an image showing the mark.

3. The mark is a two-dimensional code including information indicating the weight of the item, 3. The automated guided vehicle system according to claim 2, wherein, when the weight of the item indicated by the information contained in the two-dimensional code is equal to or greater than a threshold value, the control unit controls the driving unit to reduce the driving speed of the automated guided vehicle to a predetermined driving speed that is equal to or greater than the conveying speed of the item and slower than the previous driving speed.

4. The mark is a two-dimensional code including information indicating the weight of the item, The automated guided vehicle system according to claim 2, wherein the control unit controls the travel drive unit to reduce the movement speed of each arm that retracts each arm from the space above the conveyor into the automated guided vehicle as the weight of the item indicated by the information contained in the two-dimensional code becomes heavier.

5. a second claw portion provided on a rear end side of the pair of arms, protruding from an arm portion on the rear end side into a space between the arms and retracting into the arm portion; A second claw drive unit that causes each of the second claw portions to perform the protruding and retracting operations, 2. The automated guided vehicle system according to claim 1, wherein the control unit controls the arm drive unit and the second claw drive unit to protrude each of the second claw portions from the arm portions on the rear end side of each of the arms into the space between each of the arms, thereby causing each of the arms to protrude outward from within the automated guided vehicle.

6. An unmanned transport vehicle that travels along a conveyor that carries and transports objects, a travel drive unit that rotates drive wheels of the automated guided vehicle to cause the automated guided vehicle to travel; a pair of arms which are provided at respective positions on the unmanned transport vehicle which are downstream and upstream in a direction in which the conveyor transports the article when the unmanned transport vehicle travels along the conveyor, extend in a direction perpendicular to the direction in which the article is transported, face each other at positions spaced apart by a distance corresponding to a width of the article in the direction in which the conveyor transports the article, and reciprocate in the perpendicular direction to protrude outward from the unmanned transport vehicle and are retracted into the unmanned transport vehicle from the protruding position; an arm driving unit that causes each of the arms to reciprocate in the orthogonal direction; a first claw portion provided on a tip end side of each of the pair of arms, protruding from an arm portion on the tip end side into a space between the arms and retracting into the arm portion; a first claw drive unit that causes each of the first claw portions to perform the protruding and retracting operations; a control unit that controls the travel drive unit, the arm drive unit, and the first claw drive unit to travel the unmanned transport vehicle along the conveyor at a travel speed faster than a transport speed of the article, and to cause the arm provided on the upstream side to protrude above the conveyor from the unmanned transport vehicle, and when the arm provided on the upstream side in the transport direction moves to a position of the article being transported by the conveyor, to cause the arm provided on the downstream side to protrude above the conveyor from the unmanned transport vehicle, and with the article present between the arms, to protrude each of the first claw units from the tip side of each arm into the space between the arms, and then to retract each of the arms from above the conveyor into the unmanned transport vehicle.

7. a second claw portion provided on a rear end side of the pair of arms, protruding from an arm portion on the rear end side into a space between the arms and retracting into the arm portion; A second claw drive unit that causes each of the second claw portions to perform the protruding and retracting operations, The unmanned transport vehicle according to claim 6, wherein the control unit controls the arm driving unit and the second claw driving unit to protrude each of the second claw portions from the arm portion on the rear end side of each of the arms into the space between each of the arms, thereby causing each of the arms to protrude outward from within the unmanned transport vehicle.

Images