Unmanned transport vehicle system and unmanned transport vehicle

Abstract

A control unit (74) controls each of drive motors (33, 45, 55, 56) to: cause an unmanned transport vehicle (10) to travel along a conveyor device (11A) at a traveling speed faster than the transport speed of an article; cause an arm (42) on the downstream side in the transport direction to project toward a space above the conveyor device (11A) and cause the unmanned transport vehicle (10) to travel at a traveling speed slower than the transport speed of the article; cause, when the arm (42) on the downstream side in the transport direction is caught up by an article, an arm (42) on the upstream side in the transport direction to project outward to pinch the article between the arms (42); cause the arms (42) to be drawn in; and grab the article by claws (51) at the tips of the arms (42) to transfer the article to the unmanned transport vehicle (10).

Description

Automated guided vehicle system and automated guided vehicle

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

[0002] In recent years, various systems for transporting items using automatic guided vehicles (AGVs) have been proposed. For example, in an automatic guided vehicle system described in Patent Document 1, a package is transported by a conveyor, and when the package arrives at the end of the conveyor, a nearby automatic guided vehicle is called, a robot loads the package onto the automatic guided vehicle, and the automatic guided vehicle transports the package to a shelf where it is stored.

[0003] Japanese Patent Application Laid-Open No. 2020-123196

[0004] However, when using the technology disclosed in Patent Document 1, in which luggage is transported by a conveyor and then loaded onto an unmanned transport vehicle by a robot after the luggage arrives at the end of the conveyor, the time from when the conveyor starts transporting the luggage to when the luggage is loaded onto the unmanned transport vehicle becomes long, and the luggage is not moved efficiently.

[0005] Furthermore, it is anticipated that an arm robot or the like will be used as a robot for loading luggage onto an automated guided vehicle. However, when such a robot is used, the system configuration becomes complicated, which may increase the system cost.

[0006] The present invention has been made in consideration of the above circumstances, and aims to efficiently move articles by enabling articles to be transferred from a conveyor to an unmanned transport vehicle while the unmanned transport vehicle is traveling along the conveyor with a simple configuration.

[0007] an arm drive unit for causing each of the pair of arms to reciprocate; a pair of first claws provided at the distal ends of the pair of arms, each of the first claws being configured to protrude from the distal ends into a space between the pair of arms and to retract into the distal ends of the pair of arms; and a pair of first claws provided at the distal ends of the pair of arms, each of the first claws being configured to protrude from the distal ends into a space between the pair of arms and to retract into the distal ends of the pair of arms. and a control unit that controls the travel drive unit, arm drive unit, and first claw drive unit to travel the unmanned transport vehicle at a predetermined first travel speed that is faster than the transport speed of the article, and when one arm provided downstream in the article transport direction passes the position of the downstream end of the article being transported by the conveyor in the transport direction, causes the one arm to protrude from the unmanned transport vehicle above the conveyor, and with one arm protruded, causes the unmanned transport vehicle to travel at a predetermined second travel speed that is slower than the transport speed of the article, and when one arm moves to the position of the end of the article being transported by the conveyor, causes the other arm provided upstream to protrude from the unmanned transport vehicle above the conveyor, and when an article is present between the pair of arms, causes the pair of first claws to protrude from the tip ends of the pair of arms into the space between the pair of arms, and causes the pair of arms to retract from above the conveyor into the unmanned transport vehicle.

[0008] According to another aspect of the present invention, an automated guided vehicle includes a drive wheel, a travel drive unit that rotates the drive wheel to travel the automated guided vehicle, a pair of arms that are provided at positions on the automated guided vehicle that are downstream and upstream in the direction of article transport by the conveyor when the automated guided vehicle travels along the conveyor that transports articles loaded thereon, extending in a direction perpendicular to the direction of article transport, facing each other at positions spaced a distance equivalent to the width of the article in the direction of article transport, and configured to reciprocate in the perpendicular direction so as to be capable of protruding outward from the automated guided vehicle and being retracted into the automated guided vehicle from the protruding position, an arm drive unit that causes each of the pair of arms to reciprocate, a pair of first claws that are provided at the respective tips of the pair of arms and configured to be capable of protruding from the tips into the space between the pair of arms and retracting into the tips, and a pair of arms that are configured to protrude and retract relative to each of the pair of first claws. 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 at a predetermined first travel speed that is faster than the transport speed of the article, and when one arm provided downstream in the article transport direction passes the position of the downstream end of the article being transported by the conveyor in the transport direction, causes the one arm to protrude above the conveyor from the unmanned transport vehicle, and with one arm protruded, causes the unmanned transport vehicle to travel at a predetermined second travel speed that is slower than the transport speed of the article, and when one arm moves to the position of the end of the article being transported by the conveyor, causes the other arm provided upstream to protrude above the conveyor from the unmanned transport vehicle, and when an article is present between the pair of arms, causes the pair of first claw units to protrude from the tip ends of the pair of arms into the space between the pair of arms, and causes the pair of arms to retract from above the conveyor into the unmanned transport vehicle.

[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 the unmanned transport vehicle is traveling along the conveyor, thereby enabling efficient movement of articles.

[0010] 7A is a plan view schematically showing an automated guided vehicle system according to an embodiment of the present invention; FIG. 7B is a perspective view schematically showing an automated guided vehicle; FIG. 7C is a perspective view showing a sliding state of each arm of the automated guided vehicle; FIG. 7D is a schematic view of a rack gear and a pinion gear for reciprocating the arms; FIG. 7E is a perspective view showing a mechanism for extending and retracting the first claw portion and the second claw portion of each arm; FIG. 7F is a plan view showing a mechanism for extending and retracting the first claw portion and the second claw portion of each arm; FIG. 7G is a block diagram showing a control system of the automated guided vehicle; FIG. 7H is a flowchart showing a control procedure for an article movement process; FIG. 7H is a flowchart showing a control procedure subsequent to FIG. 7A; 1 is a perspective view showing a state in which a case being transported by a first conveyor is sandwiched between the arms, with first claw portions on the inside of the tip end of each arm protruding; FIG. 2 is a perspective view showing an automated guided vehicle carrying a case that has been transferred from the first conveyor; FIG. 3 is a perspective view showing a state in which an automated guided vehicle is stopped in front of a storage shelf; FIG. 4 is a perspective view showing a state in which a case is sandwiched between the arms of the automated guided vehicle, with second claw portions on the inside of the rear end of each arm protruding; FIG. 5 is a perspective view showing a process in which a case is being transferred from an automated guided vehicle to a storage shelf; FIG. 6 is a perspective view showing an automated guided vehicle that has transferred a case to a storage shelf;

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

[0012] 1 is a schematic diagram showing an automated guided vehicle system Sy according to one embodiment of the present invention. The automated guided vehicle system Sy includes an automated guided vehicle 10 and a conveyor device 11 for transporting articles. The automated guided vehicle system Sy is installed indoors, such as in a warehouse, that includes storage shelves 12.

[0013] The automated guided vehicle 10 travels by itself 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. The automated guided vehicle 10 is equipped with a magnetic sensor that detects the magnetic tape. In the automated guided vehicle 10, a control unit 74 (described later) detects the position of the magnetic tape (travel line 15) based on information obtained from the magnetic sensor, and performs steering control according to the position of the travel line 15 to cause the automated guided vehicle 10 to travel along the travel line 15.

[0014] Alternatively, the travel line 15 is a colored tape attached to the floor, the color or reflectivity of which is different from that of the floor surface. The AGV 10 is equipped with an optical sensor such as a CCD that detects the colored tape. In the AGV 10, a control unit 74 (described later) detects the position of the colored tape (travel line 15) based on information obtained from the optical sensor, and performs steering control according to the position of the travel line 15 to cause the AGV 10 to travel along the travel line 15.

[0015] Both the above-mentioned method using a magnetic tape and a magnetic sensor and the method using a color tape and an optical sensor are known technologies.

[0016] 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 include a plurality of rollers 16 arranged in parallel along the conveying direction of the cases CS (an example of an article).

[0017] Each roller 16 is supported on the frame of the first conveyor 11A or the second conveyor 11B by its own axis perpendicular to the transport direction of the cases CS. Each roller 16 is driven to rotate in one direction to transport the cases CS on each roller 16. Note that belt conveyors may also be used as the first conveyor 11A and the second conveyor 11B.

[0018] The travel lines 15 include a first travel line 15A, a second travel line 15B, a third travel line 15C, and a fourth travel line 15D, which are connected to form a rectangle. Each of the travel lines 15A to 15D is linear. The first travel line 15A extends parallel to the direction in which the first conveyor 11A extends (the direction in which the cases CS are transported). The fourth travel line 15C passes near the storage shelf 12.

[0019] The automated guided vehicle 10 starts traveling from a standby position HP located near the start of the first traveling line 15A, and travels along the first traveling line 15A parallel to the first conveyor 11A. The automated guided vehicle 10 turns its traveling direction by 90 degrees at the end of the first traveling line 15A and starts traveling along the second traveling line 15B. The automated guided vehicle 10 turns its traveling direction by 90 degrees at the end of the second traveling line 15B and starts traveling along the third traveling line 15C. The automated guided vehicle 10 travels along the third traveling line 15C to reach the storage shelf 12, and then turns its traveling direction by 90 degrees at the end of the third traveling line 15C and starts traveling along the fourth traveling line 15D. The automated guided vehicle 10 changes direction by 90 degrees at the end of the fourth traveling line 15D, starts traveling along the first traveling line 15A, and returns to the standby position HP near the start of the first traveling line 15A.

[0020] Fig. 2 is an enlarged perspective view showing a schematic view of the automated guided vehicle 10. As shown in Fig. 2, the automated guided vehicle 10 includes a running unit 22 provided on the underside of the vehicle body, and a working unit 23 provided on the upper side of the vehicle body.

[0021] Casters 31 are provided at the four corners of the bottom of the running part 22. A plurality of drive wheels 32 are provided at a distance from each other on the inside of the bottom of the running part 22. Each drive wheel 32 is rotated by a corresponding travel drive motor 33, and as the automated guided vehicle 10 moves, the wheels of each caster 31 are rotated accordingly. The travel drive motors 33 that rotate the drive wheels 32 are controlled for each drive wheel 32, adjusting the rotation speed of each drive wheel 32. This adjustment allows the automated guided vehicle 10 to change its traveling direction.

[0022] The working unit 23 includes a pair of support walls 41 that protrude from and face each other on the upper surface of the working unit 23. Each support wall 41 supports an arm 42 at its upper portion and outer side wall. Each arm 42 is, for example, in the form of a hollow housing. Each arm 42 is supported on each support wall 41 via slide rails 43 so as to be slidable along the support wall 41. The distance between the arms 42 is set to a predetermined distance that is slightly longer than the width of the case CS transported by the conveyor device 11. The arms 42 can insert and clamp the case CS between them.

[0023] 3 is a perspective view showing the sliding state of each arm 42. Each arm 42 is slidably supported on each support wall 41 by two slide rails 43 extending horizontally. Each arm 42 is guided in its movement direction by the slide rails 43 and can move back and forth in the longitudinal direction of each arm 42. Each slide rail 43 has, for example, a configuration known as a three-stage pull-out. Each slide rail 43 has a configuration in which a portion thereof protrudes outward, toward the side of the working unit 23, and can move.

[0024] The slide rails 43 have a first rail provided on the side wall of the support wall 41, and a second rail that is engaged with and supported by the first rail and whose movement direction is guided by the first rail to move to the outside, to the side of the working unit 23. The second rail is attached to the arms 42. As a result, each arm 42 is configured to move back and forth in the horizontal direction, allowing the entire arm 42 to protrude outward from the automatic guided vehicle 10 and to be retracted into the automatic guided vehicle 10 from the protruding position.

[0025] As shown in Figure 4, a rack gear 44 is provided at the lower end of each arm 42. Each support wall 41 is provided with a respective arm drive motor 45 (shown in Figure 6). 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 moves back and forth while being guided in the movement direction by the slide rail 43.

[0026] The outward movement of the arm 42 is limited to a position where the arm 42 is not released from the engagement and support by the support wall 41 and the slide rail 43, as shown in Figure 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.

[0027] 2 and 3 , a slit 42A is formed in the side surface on the inside of the tip end of each arm 42 (the side facing the other opposing arm 42). Each slit 42A is provided with a first claw 51 that protrudes into the space between the arms 42. A slit 42B is formed in the side surface on the inside of the rear end (base end) of each arm 42 (the side facing the other opposing arm 42). Each slit 42B is provided with a second claw 52 that protrudes into the space between the arms 42.

[0028] As shown in Figures 5A and 5B, each first claw 51 is supported by a rotary shaft 53 inside the hollow, housing-like arm 42. Each second claw 52 is supported by a rotary shaft 54 ​​inside the hollow, housing-like arm 42. Each first claw 51 is rotated back and forth by a claw drive motor 55 (shown in Figure 6) connected to each rotary shaft 53, and performs an action of protruding from the slit 42A into the space between the arms 42 and moving from the space to retract into the arm 42. Each second claw 52 is rotated back and forth by a claw drive motor 56 (shown in Figure 6) connected to each rotary shaft 54, and performs an action of protruding from the slit 42B into the space between the arms 42 and moving from the space to retract into the arm 42.

[0029] 2 and 3 , an imaging camera 71, such as a CCD, is provided above the working unit 23. The imaging camera 71 is oriented so as to face the space above the first conveyor 11A when the automated guided vehicle 10 travels along the first traveling line 15A parallel to the first conveyor 11A. In this embodiment, the imaging camera 71 is disposed on the base end side of each arm 42, in the center of the area between the two support walls 41 on the working unit 23 in the traveling direction of the automated guided vehicle 10.

[0030] The imaging camera 71 captures an image of a two-dimensional code (e.g., a QR code (registered trademark)) Q or a mark attached to a case CS being transported on the first conveyor 11A. The imaging camera 71 may be located on the base end side of each arm 42, in the traveling direction of the automated guided vehicle 10, outside one of the support walls 41 on the working unit 23 (outside the area sandwiched between the two support walls 41), or on an upper part of one of the support walls 41, on the side wall facing the other support wall 41. The imaging camera 71 may also be located at a position other than the base end side of each arm 42, as long as it is a position where it can capture an image of the two-dimensional code Q or a mark attached to a case CS being transported on the first conveyor 11A.

[0031] Fig. 6 is a block diagram showing a control system of the automated guided vehicle 10. As shown in Fig. 6, the automated guided vehicle 10 includes travel drive motors 33, arm drive motors 45, claw drive motors 55, claw drive motors 56, an imaging camera 71, a travel line sensor 72, a communication unit 73, and a control unit 74.

[0032] Each travel drive motor 33 rotates and drives each drive wheel 32 of the travel unit 22. Each arm drive motor 45 horizontally moves each arm 42 of the working unit 23. Each claw drive motor 55 causes each first claw 51 to protrude from the slits 42A on the inside of both ends of each arm 42 into the space between the arms 42 and to retract into the arm 42.

[0033] Each claw drive motor 56 causes each second claw 52 to protrude from the slits 42B on the inside of both ends of each arm 42 into the space between the arms 42 and to retract into the arm 42. The imaging camera 71 captures an image of the two-dimensional code Q attached to the case CS on the first conveyor 11A. The travel line sensor 72 detects the travel line 15.

[0034] The communication unit 73 is a communication interface equipped with a communication module such as a LAN chip. The communication unit 73 is connected to the terminal device 81 via a wired or wireless LAN, and transmits and receives data to and from the terminal device 81. The terminal device 81 is, for example, a PC (personal computer), and is operated by a user.

[0035] The control unit 74 includes a processor, a random access memory (RAM), a read-only memory (ROM), and a dedicated hardware circuit. The processor is, for example, a central processing unit (CPU), an application specific integrated circuit (ASIC), or a micro processing unit (MPU). The control unit 74 performs overall control of the automated guided vehicle 10 by the operation of the processor in accordance with a control program stored in the ROM.

[0036] 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 controls the drive of the travel drive motor 33 of each drive wheel 32 separately for each drive wheel 32 according to the detected position of the travel line 15, thereby adjusting the rotation speed of the drive wheel 32. By adjusting the rotation speed, the control unit 74 changes the traveling direction of the automated guided vehicle 10, and causes the automated guided vehicle 10 to travel along the travel line 15 with the longitudinal direction of each arm 42 perpendicular to the travel line 15. The control unit 74 also adjusts the travel speed V of the automated guided vehicle 10.

[0037] The control unit 74 drives and controls each arm drive motor 45 to reciprocate each arm 42. The control unit 74 drives and controls each claw drive motor 55, 56 to protrude each claw 51, 52 from the respective slits 42A, 42B formed at both ends of each arm 42, or to retract each claw 51, 52 into the arm 42. The control unit 74 also acquires an image captured by the imaging camera 71, analyzes the image, and identifies the two-dimensional code Q included in the image.

[0038] Under the control of the control unit 74, the automated guided vehicle 10 stops and waits at the standby position HP, and when the first conveyor 11A starts transporting a case CS, the automated guided vehicle 10 travels along the first traveling line 15A parallel to the first conveyor 11A while driving each arm 42 to transfer the case CS being transported by the first conveyor 11A to the automated guided vehicle 10. Under the control of the control unit 74, the automated guided vehicle 10 travels along the first traveling line 15A, the second traveling line 15B, and the third traveling line 15C in this order, and moves to and stops in front of the storage shelf 12. Under the control of the control unit 74, the automated guided vehicle 10 transfers the case CS to the storage shelf 12, and travels along the third traveling line 15C, the fourth traveling line 15D, and the first traveling line 15A in this order, before returning to the standby position HP.

[0039] Next, the control procedure for the item movement process to transfer the case CS being transported by the first conveyor 11A to the unmanned transport vehicle 10 and move the case CS by the unmanned transport vehicle 10 will be explained in detail with reference to the flowcharts shown in Figures 7A and 7B.

[0040] As shown in Figure 1, while the automated guided vehicle 10 is waiting at a standby position HP on the first travel line 15A, the second conveyor 11B begins transporting a case CS. The standby position HP is located at the end of the second conveyor 11B, to the side of the position where it connects to the first conveyor 11A (the starting point of the first conveyor 11A). The case CS on the second conveyor 11B is transported with the attached two-dimensional code Q facing the standby position HP. After the case CS has been transported to the position indicated by the dashed line in Figure 1, the first conveyor 11A switches its transport direction to the direction of the arrow shown in Figure 1 and continues transporting the case.

[0041] The automated guided vehicle 10, which is at the standby position HP, captures an image of the two-dimensional code Q on the case CS with the imaging camera 71 when the case CS is transported to the position indicated by the dashed line in Figure 1. The imaging camera 71 of the automated guided vehicle 10, which is at the standby position HP, is located opposite the two-dimensional code Q on the side of the case CS. The two-dimensional code Q contains identification information that indicates an ID unique to the case CS. In the automated guided 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 included in the two-dimensional code Q is the same as the ID indicated by identification information previously received from the terminal device 81 via the communication unit 73.

[0042] When the control unit 74 determines that the above conditions are the same, it starts the automatic guided vehicle 10 traveling in the direction of the arrow shown in Figure 1 (step S101). At this point, the first conveyor 11A has started transporting the case CS without changing the position of the case CS. Therefore, the case CS has already passed the position shown by the dashed line in Figure 1, i.e., the standby position HP.

[0043] The control unit 74 detects the position of the traveling line 15 based on the detection output of the traveling line sensor 72, and drives and controls the traveling drive motors 33 of each drive wheel 32 according to the detected position of the traveling line 15, so that the unmanned guided vehicle 10 travels along the first traveling line 15A, parallel to the first conveyor 11A, and in a position close to the first conveyor 11A, with the extension direction of each arm 42 (the longitudinal direction of the arm 42) perpendicular to the traveling line 15, as shown in Figure 8A.

[0044] At this time, the control unit 74 sets the travel speed V of the automatic guided vehicle 10 to a predetermined travel speed VA that is faster than the transport speed VS of the case CS by the first conveyor 11A (step S102). When the travel speed V of the automatic guided vehicle 10 is set to the predetermined travel speed VA that is faster than the transport speed VS of the case CS by the first conveyor 11A, one arm 42 provided on the more downstream side in the transport direction of the case CS passes over the position of the downstream end of the case CS being transported by the first conveyor 11A in the transport direction.

[0045] A predetermined mark (for example, a hole formed in the side surface or a predetermined image printed on the side surface, or a two-dimensional code Q) is provided on the side surface of the case CS facing the automated guided vehicle 10. The imaging camera 71 is provided in a position where it can capture an image of the side surface of the case CS while one of the arms 42 on the downstream side in the conveying direction is passing the case CS. The imaging camera 71 captures an image of the mark when one of the arms 42 is passing the case CS.

[0046] The control unit 74 acquires the image captured by the imaging camera 71, analyzes the image, and identifies an image showing the mark included in the image (step S103). The control unit 74 starts measuring the elapsed time from the point in time when the mark is identified, and when the elapsed time reaches a certain time, determines that the one arm 42 provided on the downstream side has moved to a position beyond the downstream end of the case CS being transported by the first conveyor 11A in the transport direction (step S104).

[0047] The control unit 74 controls the driving of one of the two arm drive motors 45 to project one arm 42 located downstream in the conveying direction of the case CS into the space above the first conveyor 11A (step S105), as shown in Figures 8B and 9. The control unit 74 controls the driving of the travel drive motor 33 of the drive wheel 32 to set the traveling speed V of the automated guided vehicle 10 to a predetermined traveling speed VB that is slower than the transport speed VS of the case CS by the first conveyor 11A (step S106).

[0048] When the travel speed V of the automatic guided vehicle 10 is set to the travel speed VB, which is slower than the transport speed VS of the case CS by the first conveyor 11A, one arm 42 provided on the more downstream side in the transport direction catches up with and comes into contact with the case CS. In other words, the one arm 42 provided on the downstream side moves to the position of the end of the case CS being transported by the first conveyor 11A.

[0049] In step S106, the control unit 74 may perform a second speed control described below. The two-dimensional code Q identified in step S103 includes weight information indicating the weight of the items contained in the case CS. The weight information may indicate the weight itself, or, for example, the weight of each item and the number of items contained. After processing step S103 and before processing step S106, the control unit 74 determines the weight of the items based on the weight information and calculates the weight of the items by adding the known weight of the case CS to the weight of the items. Note that the weight information may indicate the weight of the items themselves, calculated by adding the known weight of the case CS to the weight of the items. In this case, the control unit 74 obtains the weight of the items directly from the weight information.

[0050] At the time when the processing of step S105 is performed, the control unit 74 is driving and controlling the travel drive motors 33 of each drive wheel 32 to cause the automatic guided vehicle 10 to travel at the travel speed VA set in step S102. The control unit 74 compares the calculated weight of the item with a preset threshold. If the control unit 74 determines that the weight of the item is less than the preset threshold, it sets the travel speed V of the automatic guided vehicle 10 to the above-mentioned travel speed VB (step S106).

[0051] If the weight of the item is equal to or greater than the threshold value, the control unit 74 sets the traveling speed V of the automated guided vehicle 10 to a predetermined adjusted traveling speed VD that is faster than the traveling speed VB and equal to or less than the conveying speed VS of the case CS (step S106). By setting the traveling speed V of the automated guided vehicle 10 to the adjusted traveling speed VD in this way, when the weight of the item contained in the case CS is equal to or greater than the threshold value and is heavy, the traveling speed V of the automated guided vehicle 10 is slower than the conveying speed VS of the case CS, but the speed difference between the traveling speed V and the conveying speed VS becomes small.

[0052] As a result, when the automated guided vehicle 10 is traveling with the protruding one of the downstream arms 42 being pushed by the case CS, it is possible to reduce the load on each travel drive motor 33 and also reduce the load from the case CS that is applied to the one of the downstream arms 42. Therefore, the automated guided vehicle 10 can travel stably.

[0053] After step S106, when the unmanned transport vehicle 10 approaches the position of the case CS being transported by the first conveyor 11A in the transport direction of the case CS and the two-dimensional code Q of the case CS is again positioned within the imaging range of the imaging camera 71, the control unit 74 acquires the image captured by the imaging camera 71, analyzes the image, and again identifies the two-dimensional code Q contained in the image (step S107).

[0054] When identifying again, the control unit 74 assumes that one of the arms 42 located on the downstream side has moved to the position of the above-mentioned end of the case CS being transported by the first conveyor 11A, and controls the drive of the arm drive motor 45 for driving the other arm 42 located upstream in the transport direction of the case CS, causing the other arm 42 located upstream in the transport direction of the case CS to protrude into the space above the first conveyor 11A, as shown in Figure 10A (step S108).

[0055] The distance between the arms 42 is set to a distance equivalent to the width of the case CS, which is slightly longer than the width of the case CS. Therefore, when the other arm 42 extends, the case CS is sandwiched between the arms 42. The arms 42 are extended under the control of the control unit 74, and have a length such that the tip of each arm 42 reaches a position beyond the rear end of the case CS in a direction perpendicular to the conveyance direction of the case CS. The control unit 74 extends each arm 42 until the tip of each arm 42 reaches a position beyond the rear end of the case CS ( FIGS. 10A and 11 ).

[0056] After processing step S108, the control unit 74 may drive and control the driving motors 33 of each driving wheel 32 so that the driving speed VB (or adjusted driving speed VD) of the unmanned guided vehicle 10 is the same as the conveying speed VS of the case CS by the first conveyor 11A.

[0057] Next, the control unit 74 controls the drive of each claw drive motor 55 to protrude the first claw 51 on the inside of the tip of each arm 42 (step S109), as shown in Figures 10B and 11. Here, even if the second speed control is not performed, the control unit 74 completes the process of calculating the weight of the item based on the two-dimensional code Q described above after the process of step S103 and before the process of step S112 (step S110).

[0058] After step S110, the control unit 74 may set the traveling speed V of the unmanned guided vehicle 10 according to the weight of the item calculated in step S110, in the same manner as the second speed control described above (step S111).

[0059] The control unit 74 sets the rotation speed of each arm drive motor 45 according to the weight of the article (step S112). For example, the control unit 74 sets the rotation speed of each arm drive motor 45 to be slower as the weight of the article increases. For example, the control unit 74 stores in advance in its built-in ROM a data table indicating the weight of the article and the rotation speed of each arm drive motor 45 corresponding to that weight for each weight of the article. The control unit 74 reads from the data table the rotation speed of each arm drive motor 45 corresponding to the calculated weight of the article, and sets the read rotation speed as the rotation speed of each arm drive motor 45 corresponding to the calculated weight of the article.

[0060] The control unit 74 controls the drive of each arm drive motor 45 to rotate each arm drive motor 45 at the rotation speed set in step S112, and as shown in Fig. 12, each arm 42 is retracted from the space above the first conveyor 11A and retracted from the protruding position as described above into an area within the working unit 23 of the automatic guided vehicle 10. When each arm 42 is retracted, each first claw 51 catches on the end of the case CS, and each arm 42 retracts the case CS from the first conveyor 11A into the working unit 23 of the automatic guided vehicle 10 (step S113).

[0061] That is, by retracting each arm 42, the case CS moves from its position on the first conveyor 11A onto the working section 23 of the automatic guided vehicle 10. In this way, the heavier the item, the slower the movement speed of each arm 42 is, and the case CS is transferred at a slower speed from the first conveyor 11A to the working section 23 of the automatic guided vehicle 10. Therefore, when each arm 42 retracts the case CS into the working section 23 of the automatic guided vehicle 10, the load on each arm drive motor 45 can be reduced.

[0062] In addition, the movement of the case CS from its position on the first conveyor 11A to the working section 23 of the unmanned transport vehicle 10 is carried out while transport by the first conveyor 11A and the movement of the unmanned transport vehicle 10 continue, but since this movement is carried out at a low speed, the case CS can be moved stably and reliably from its position on the first conveyor 11A to the working section 23 of the unmanned transport vehicle 10.

[0063] After each arm 42 is retracted, the control unit 74 controls the drive of each claw drive motor 55 to retract each first claw 51 and store it inside the arm 42. In this way, the control unit 74 transfers the case CS being transported by the first conveyor 11A from the first conveyor 11A to the automatic guided vehicle 10 while causing the automatic guided vehicle 10 to travel along the first travel line 15A parallel to the first conveyor 11A.

[0064] The control unit 74 detects the position of the driving line 15 based on the detection output of the driving line sensor 72, and controls the driving of the driving drive motors 33 of each drive wheel 32 according to the detected position of the driving line 15, causing the unmanned guided vehicle 10 to travel along a route in the order of the first driving line 15A, the second driving line 15B, and the third driving line 15C (step S114).

[0065] When the automated guided vehicle 10 travels to the position of the storage shelf 12, the control unit 74 uses the imaging camera 71 to capture images of two-dimensional codes attached to different positions on the storage shelf 12 along the traveling direction of the automated guided vehicle 10. The control unit 74 analyzes the captured two-dimensional codes to detect location information of the storage shelf 12 contained in the two-dimensional codes. The control unit 74 has previously received, via the communication unit 73, the location information of the storage shelf 12 linked to the ID unique to the case CS.

[0066] When the control unit 74 captures an image of the two-dimensional code including location information that matches the location information of the storage shelf 12 linked to the ID, it stops the automated guided vehicle 10 at the position at that time, as shown in Fig. 13 (step S115). At this time, the automated guided vehicle 10 is in a position where the tip ends of the arms 42 to which the first claws 51 are attached are facing the storage shelf 12 due to the direction changes that occur when the automated guided vehicle 10 changes paths along the first traveling line 15A, the second traveling line 15B, and the third traveling line 15C.

[0067] The control unit 74 controls the drive of each claw drive motor 56 to protrude the second claw 52 on the inside of the rear end of each arm 42 (step S116), as shown in Figures 13 and 14. At this time, the second claw 52 on the inside of the rear end of each arm 42 is positioned on the end side of the case CS, opposite the storage shelf 12.

[0068] The control unit 74 controls the drive of each arm drive motor 45 to project each arm 42 toward the storage shelf 12, as shown in Figures 15 and 16 (step S117). The amount of projection at this time is set to an amount that allows the second claw portion 52 on the inside of the rear end of each arm 42 to enter at least to a position above the storage shelf 12. The slide rail 43 is configured so that the second rail is engaged and supported by the first rail, and the movement direction is guided by the first rail, so that the second rail can also move outward toward the storage shelf 12 (the opposite direction from the outward direction toward the first conveyor 11A shown in Figure 3).

[0069] The control unit 74 causes each second claw 52 to hook onto the case CS by causing each arm 42 to protrude toward the storage shelf 12, and each arm 42 and second claw 52 pushes the case CS from above the working unit 23 of the automatic guided vehicle 10 into the storage shelf 12, thereby moving the case CS from above the working unit 23 of the automatic guided vehicle 10 to the storage shelf 12. The control unit 74 drives and controls each claw drive motor 56 to retract each second claw 52 and store it inside the arm 42.

[0070] 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 each drive wheel 32 according to the detected position of the travel line 15, causing the automated guided vehicle 10 to travel along a route in the order of the third travel line 15C, the fourth travel line 15D, and the first travel line 15A. The control unit 74 stops the travel drive motors 33 of each drive wheel 32 a certain time after the automated guided vehicle 10 changes its direction of travel 90 degrees between the fourth travel line 15D and the first travel line 15A, and stops the automated guided vehicle 10 at the standby position HP (step S118).

[0071] Thus, in this embodiment, when the first conveyor 11A starts transporting the case CS, the automatic guided vehicle 10 travels along the first travel line 15A parallel to the first conveyor 11A, and the travel speed V of the automatic guided vehicle 10 is set to a travel speed VA that is faster than the transport speed VS of the case CS. When one arm 42 on the downstream side in the transport direction moves to a position beyond the case CS, the one arm 42 extends, and then the travel speed V of the automatic guided vehicle 10 is set to a travel speed VB that is slower than the transport speed VS of the case CS.

[0072] When one arm 42 comes into contact with the end of the case CS, the other arm 42 located upstream in the conveying direction projects, and the case CS is sandwiched between the arms 42. In this state, the first claws 51 on the inside of the tip of each arm 42 project, and each arm 42 is pulled back toward the automated guided vehicle 10. At this time, each first claw 51 catches on the case CS, and the arm 42 and the first claw 51 push the case CS from the first conveyor 11A into the working section 23 of the automated guided vehicle 10, and the case CS moves onto the working section 23 of the automated guided vehicle 10.

[0073] According to this embodiment, while the unmanned guided vehicle 10 is running, the case CS being transported by the first conveyor 11A can be transferred to the unmanned guided vehicle 10, thereby allowing the case CS to be moved efficiently.

[0074] <First Modification> In the first modification, the working unit 23 of the automated guided vehicle 10 moves up and down in the vertical direction. For example, a plurality of support pillars are provided to protrude from the travelling unit 22 of the automated guided vehicle 10, and the working unit 23 is supported by each support pillar so as to be freely movable in the vertical direction, and the working unit 23 is moved up and down by a plurality of ball screws, which are a known mechanism. The ball screws include a screw shaft that protrudes from and is rotatably supported by the travelling unit 22, and a nut that is fixed to the working unit 23 and is screwed onto the screw shaft.

[0075] The traveling unit 22 is equipped with a lifting motor that rotates each screw shaft. The control unit 74 causes each lifting motor to rotate each screw shaft in one direction, thereby raising each nut and the working unit 23. The control unit 74 also causes each lifting motor to rotate each screw shaft in the opposite direction, thereby lowering each nut and the working unit 23. According to the first modification, even if the heights of the conveyor device 11 and the storage shelf 12 change, the working unit 23 can be raised and lowered to match the heights of the conveyor device 11 and the storage shelf 12, making it possible to transfer the case CS between the working unit 23 and the conveyor device 11 or the storage shelf 12.

[0076] <Second Modification> In the second modification, the separation distance between the arms 42 is changed. For example, the working unit 23 is provided with a rack gear extending in the orthogonal direction at the lower end of one of the support walls 41, which supports one of the support walls 41 so as to be slidable in a direction perpendicular to the longitudinal direction of the arm 42. Furthermore, the working unit 23 is provided with a pinion gear that meshes with the rack gear and a motor that rotates the pinion gear back and forth.

[0077] Under the control of the control unit 74, the motor rotates the pinion gear back and forth, causing the rack gear to move back and forth. This moves one support wall 41 and arm 42 toward or away from the other support wall 41 and arm 42, changing the separation distance between the arms 42. According to the second modification, even if the width of the case CS changes, it is possible to sandwich the case CS between the arms 42 and transfer the case CS between the work unit 23 and the conveyor device 11 or the storage shelf 12.

[0078] 1 to 17 is merely one embodiment of the present invention, and is not intended to limit the present invention to such an embodiment. For example, in the above embodiment, the automated guided vehicle 10 takes in the case CS being transported by the conveyor device 11 and stores it in the storage shelf 12, but the present invention is not limited to such an embodiment.

[0079] For example, the control unit 74 may drive and control the travel drive motor 33, the arm drive motor 45, the claw drive motor 55, and the claw drive motor 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 guided vehicle 10 takes in a case CS stored on a storage shelf 12 onto the unmanned guided vehicle 10, transports the case CS to the position of the conveyor device 11, and transfers the case CS from the unmanned guided vehicle 10 onto the conveyor device 11.

Claims

1. A conveyor for carrying and transporting articles; an automated guided vehicle that travels along the conveyor; The automated guided vehicle is Drive wheels and a travel drive unit that rotates the drive wheels to cause the automatic guided vehicle to travel; a pair of arms that are provided at respective positions on the automated guided vehicle that are downstream and upstream in the direction in which the conveyor conveys the articles when the automated guided vehicle travels along the conveyor, extend in a direction perpendicular to the direction in which the articles are conveyed, face each other at positions spaced apart by a distance corresponding to the width of the articles in the direction in which the articles are conveyed, and move back and forth in the perpendicular direction so as to be able to protrude outward from the automated guided vehicle and be retracted into the automated guided vehicle from the protruding position; an arm driving unit that causes each of the pair of arms to perform the reciprocating movement; a pair of first claws provided at the tip ends of the pair of arms, each of which is configured to be able to protrude from the tip ends into a space between the pair of arms and to retract into the tip ends; a first claw drive unit that causes each of the pair of first claws to perform either the protruding operation or the retracting operation; Controlling the travel drive unit, the arm drive unit, and the first claw drive unit, the automated guided vehicle is caused to travel at a predetermined first travel speed that is faster than a conveying speed of the article, and when one arm provided downstream in the conveying direction of the article passes over the position of an end portion of the article being conveyed by the conveyor on the downstream side in the conveying direction, the one arm is caused to protrude from the automated guided vehicle above the conveyor; With the one arm extended, the automatic guided vehicle is caused to travel at a predetermined second travel speed that is slower than a transport speed of the article; when the one arm moves to the position of the end of the article being transported by the conveyor, the other arm provided on the upstream side is protruded above the conveyor from the automatic guided vehicle; a control unit that, when the article is present between the pair of arms, causes the pair of first claw portions to protrude from the tip ends of the pair of arms into the space between the pair of arms and retracts the pair of arms from above the conveyor into the unmanned guided vehicle.

2. 2. The automated guided vehicle system according to claim 1, wherein the control unit, after extending the other arm, causes the automated guided vehicle to travel at a traveling speed equal to a transport speed of the article by the conveyor.

3. a predetermined mark is provided at a predetermined position on the article; the automated guided vehicle further includes an imaging unit that images a space above the conveyor; 2. The automated guided vehicle system according to claim 1, wherein the control unit analyzes an image captured by the imaging unit while the automated guided vehicle is traveling at the first traveling speed, and determines that the one arm has moved to a position beyond the end of the item being transported by the conveyor when a predetermined period of time has elapsed from the time when it is determined based on the analysis that the image includes an image showing the mark.

4. a predetermined mark is provided at a predetermined position on the article; the automated guided vehicle further includes an imaging unit that images a space above the conveyor; 2. The automated guided vehicle system according to claim 1, wherein the control unit analyzes an image captured by the imaging unit while the automated guided vehicle is traveling at the second traveling speed, and when it determines based on the analysis that the image includes an image showing the mark, determines that the one arm has moved to the position of the end of the item being transported by the conveyor.

5. the mark is a two-dimensional code including weight information indicating the weight of the item, When the weight of the item indicated by the weight information is less than a threshold value, the control unit controls the traveling drive unit to maintain the second traveling speed as it is, 4. The automated guided vehicle system according to claim 3, wherein, when the weight of the item is equal to or greater than the threshold value, the second traveling speed is changed to a predetermined adjusted traveling speed that is faster than the second traveling speed and equal to or less than the conveying speed of the item, and the automated guided vehicle is caused to travel at that speed.

6. the mark is a two-dimensional code including weight information indicating the weight of the item, 4. The automated guided vehicle system according to claim 3, wherein the control unit controls the arm drive unit to reduce the movement speed of the pair of arms when retracting the pair of arms from the space above the conveyor into the automated guided vehicle as the weight of the item indicated by the weight information increases.

7. a pair of second claws provided at rear end portions of the pair of arms, each of the second claws being configured to be able to protrude from the rear end portions into a space between the pair of arms and to retract into the rear end portions; a second claw drive unit that causes each of the pair of second claws to perform either the protruding operation or the retracting operation, 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 cause the pair of second claw units to protrude from rear ends of the pair of arms into a space between the pair of arms, thereby causing the pair of arms to protrude outward from within the automated guided vehicle.

8. a rack gear extending in a direction perpendicular to the longitudinal direction of the pair of arms and supporting the one arm or the other arm so as to be slidable in the direction perpendicular to the longitudinal direction of the pair of arms; a pinion gear that meshes with the rack gear; a motor that reciprocates the pinion gear, The automated guided vehicle system according to claim 1 , wherein the control unit causes the motor to reciprocally rotate the pinion gear, thereby causing the rack gear to reciprocate, thereby changing the distance between the pair of arms.

9. Drive wheels and a travel drive unit that rotates the drive wheels to travel the automatic guided vehicle; a pair of arms that are provided at respective positions on the automated guided vehicle that are downstream and upstream in the direction of transport of the articles by the conveyor when the automated guided vehicle travels along the conveyor on which the articles are loaded and transported, extend in a direction perpendicular to the direction of transport of the articles, face each other at positions spaced apart by a distance corresponding to the width of the articles in the direction of transport of the articles, and move back and forth in the perpendicular direction so as to be able to protrude outward from the automated guided vehicle and be retracted into the automated guided vehicle from the protruding position; an arm driving unit that causes each of the pair of arms to perform the reciprocating movement; a pair of first claws provided at the tip ends of the pair of arms, each of which is configured to be able to protrude from the tip ends into a space between the pair of arms and to retract into the tip ends; a first claw drive unit that causes each of the pair of first claws to perform either the protruding operation or the retracting operation; Controlling the travel drive unit, the arm drive unit, and the first claw drive unit, the automated guided vehicle is caused to travel at a predetermined first travel speed that is faster than a conveying speed of the article, and when one arm provided downstream in the conveying direction of the article passes over the position of an end portion of the article being conveyed by the conveyor on the downstream side in the conveying direction, the one arm is caused to protrude from the automated guided vehicle above the conveyor; With the one arm extended, the automatic guided vehicle is caused to travel at a predetermined second travel speed that is slower than a transport speed of the article; when the one arm moves to the position of the end of the article being transported by the conveyor, the other arm provided on the upstream side is protruded above the conveyor from the automatic guided vehicle; and a control unit that, when the article is present between the pair of arms, causes the pair of first claw portions to protrude from the tip ends of the pair of arms into the space between the pair of arms and retracts the pair of arms from above the conveyor into the unmanned transport vehicle.

10. a pair of second claws configured to be able to protrude from rear end portions of the pair of arms into a space between the pair of arms and to retract into the rear end portions; a second claw drive unit that causes each of the pair of second claws to perform either the protruding operation or the retracting operation, 10. The automated guided vehicle according to claim 9, wherein, after the control unit has transferred the item from the conveyor to the automated guided vehicle, the control unit controls the travel drive unit, the arm drive unit, and the second claw drive unit to move the automated guided vehicle from the conveyor to a predetermined position, cause the pair of second claw units to protrude from the rear ends of the pair of arms into the space between the pair of arms, push the pair of arms out of the automated guided vehicle to the set position, hook the pair of second claw units onto the item, and transfer the item from the automated guided vehicle to the set position.