Automated guided vehicle system and automated guided 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 in particular 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 technology]

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

[0003] [Patent Document 1] JP 2020-123196 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, when transporting luggage using a conveyor as in Patent Document 1, and then having a robot load the luggage onto an unmanned transport vehicle after the luggage arrives at the end of the conveyor, the time between when the conveyor starts transporting the luggage and when the luggage is loaded onto the unmanned transport vehicle becomes long, and the luggage is not moved efficiently.

[0005] In addition, it is anticipated that arm robots and the like will be used as robots to load luggage onto automated guided vehicles, but using such robots could complicate the system configuration and increase the system costs.

[0006] The present invention has been made in consideration of the above circumstances, and has an object to enable efficient movement of articles by using a simple configuration to transfer articles from a conveyor to an unmanned transport vehicle while the unmanned transport vehicle is traveling along the conveyor. [Means for solving the problem]

[0007] An automated guided vehicle system according to one aspect of the present invention includes a conveyor for carrying and transporting an article, and an automated guided vehicle that travels along the conveyor, the automated guided vehicle including a travel drive unit that rotates drive wheels of the automated guided vehicle to travel the automated guided vehicle, a pair of arms that are provided at respective positions on the automated guided vehicle that are downstream and upstream in a direction in which the article is transported by the conveyor when the automated guided 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 a distance equivalent to a width of the article in the direction in which the article is transported by the conveyor, reciprocate in the perpendicular direction to protrude outward from the automated guided vehicle and are retracted into the automated guided vehicle from the protruding position, an arm drive unit that causes each of the arms to reciprocate in the perpendicular direction, and a pair of arms that are provided at the tip sides of the pair of arms and drive each of the arms from an arm portion at the tip side. a first claw drive unit that causes each of the first claws to perform the protruding and retracting actions; 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 cause each of the first claws to protrude from the tip side of each arm into the space between the arms, and then to cause each of the arms to retract from above the conveyor into the unmanned transport vehicle.

[0008] Moreover, an unmanned guided vehicle according to one aspect of the present invention is an unmanned guided vehicle that travels along a conveyor that transports articles loaded thereon, the unmanned guided vehicle comprising: a travel drive unit that rotates drive wheels of the unmanned guided vehicle to travel the unmanned guided vehicle; a pair of arms that are provided at respective positions on the unmanned guided vehicle that are downstream and upstream in a direction in which the article is transported by the conveyor when the unmanned guided 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 a distance equivalent to a width of the article in the direction in which the article is transported by the conveyor, reciprocate in the perpendicular direction to protrude outward from the unmanned guided vehicle and are retracted into the unmanned guided vehicle from the protruding position; an arm drive unit that causes each of the arms to reciprocate in the perpendicular direction; and a pair of arms that are provided at the tip sides of the pair of arms and extend from the arm portions at the tip sides into a space between the arms. 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 causes 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, causes 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, causes each of the first claw portions to protrude from the tip side of each arm into the space between the arms, and then causes each of the arms to retract from above the conveyor into the unmanned transport vehicle. Effect 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 the unmanned transport vehicle is traveling along the conveyor, thereby enabling efficient movement of articles. [Brief description of the drawings]

[0010] [Figure 1] 1 is a plan view showing an automated guided vehicle system according to an embodiment of the present invention; [Diagram 2] 1 is a perspective view showing an automatic guided vehicle in an automatic guided vehicle system according to an embodiment of the present invention; [Diagram 3] FIG. 4 is a perspective view showing a sliding state of each arm of the automated guided vehicle. [Figure 4] FIG. 4 is a diagram illustrating a rack gear and a pinion gear for reciprocating the arm. [Diagram 5] 13(A) and 13(B) are a perspective view and a plan view showing a mechanism for extending and retracting the first and second claw portions of each arm. FIG. [Figure 6] FIG. 2 is a block diagram showing a control system of the automated guided vehicle. [Figure 7] 10 is a flowchart showing a control procedure for transferring a case being transported by a conveyor to an unmanned transport vehicle and moving the case by the unmanned transport vehicle. [Figure 8] FIG. 1A is a perspective view showing a state in which a case is being transported by a conveyor of an automated guided vehicle system, and FIG. 1B is a perspective view showing a state in which the automated guided vehicle has caught up with the case being transported by the conveyor. [Figure 9] 1 is a perspective view showing a state in which one arm of an automatic guided vehicle comes into contact with a case being transported by a conveyor. FIG. [Figure 10] FIG. 1A is a perspective view showing a state in which a case being transported by a conveyor of an automated guided vehicle system is sandwiched between each arm of the automated guided vehicle, and FIG. 1B is a perspective view showing the process of transferring the case being transported by the conveyor to the automated guided vehicle. [Figure 11] 11 is a perspective view showing a state in which a case being transported by a conveyor is sandwiched between the arms of an unmanned transport vehicle, with first claw portions on the inside of the tip of each arm protruding. FIG. [Figure 12]FIG. 13 is a perspective view showing an automated guided vehicle carrying a case transferred from a conveyor. [Figure 13] 1 is a perspective view showing a state in which an unmanned transport vehicle has stopped in front of a storage shelf. FIG. [Figure 14] 11 is a perspective view showing a state in which a case is sandwiched between the arms of an unmanned transport vehicle and second claw portions on the inside of the rear ends of the arms are protruded. FIG. [Figure 15] FIG. 11 is a perspective view showing a process in which a case is transferred from an automated guided vehicle to a storage shelf. [Figure 16] FIG. 11 is a perspective view showing the unmanned transport vehicle in which the case has been transferred to a storage shelf. [Figure 17] 11 is a perspective view showing a state in which the case has been transferred from the automated guided vehicle to a storage shelf. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

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

[0013] The unmanned guided vehicle 10 moves 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, and the unmanned guided vehicle 10 is provided with a magnetic sensor that detects the magnetic tape. In the unmanned guided 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 make the unmanned guided vehicle 10 travel along the travel line 15. Alternatively, the travel line 15 is a colored tape attached to the floor surface and has a different color or reflectance from the floor surface, and the unmanned guided vehicle 10 is provided with an optical sensor such as a CCD that detects the colored tape. In the unmanned guided vehicle 10, a control unit (described later) detects the position of the colored tape (travel line 15) based on information obtained from the optical sensor, and steering control is performed according to the position of the travel line 15 to make the unmanned guided vehicle 10 travel along the travel line 15. Both the method using the magnetic tape and the magnetic sensor and the method using the colored tape and the optical sensor are known technologies.

[0014] The conveyor device 11 is composed of 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 have a plurality of rollers 16 arranged in a direction in which cases CS (an example of an article) are transported. Each roller 16 is supported by a frame of the first conveyor 11A and the second conveyor 11B by a respective axis perpendicular to the transport direction of the cases CS, and is driven to rotate in one direction to transport the cases CS on each roller 16. Note that a belt conveyor may be used as the first conveyor 11A and the second conveyor 11B.

[0015] The traveling line 15 is formed by connecting a first traveling line 15A, a second traveling line 15B, a third traveling line 15C, and a fourth traveling line 15D in a rectangular shape. Each of the traveling lines 15A to 15D is linear. The first traveling 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 traveling line 15D passes near the storage shelf 12.

[0016] The unmanned transport vehicle 10 starts traveling from a waiting position HP provided near the start of the first travel line 15A, travels along the first travel line 15A in parallel with the first conveyor 11A, turns its traveling direction by 90 degrees at the end of the first travel line 15A, and moves to traveling along the second travel line 15B. The unmanned transport vehicle 10 further turns its traveling direction by 90 degrees at the end of the second travel line 15B, and moves to traveling along the third travel line 15C. The unmanned transport vehicle 10 travels along the third travel line 15C to reach the storage shelf 12, and then turns its traveling direction by 90 degrees at the end of the third travel line 15C, and moves to traveling along the fourth travel line 15D. The unmanned transport vehicle 10 further turns its traveling direction by 90 degrees at the end of the fourth travel line 15D, and moves to traveling along the first travel line 15A, and returns to the waiting position HP near the start of the first travel line 15A.

[0017] Fig. 2 is an enlarged perspective view showing the schematic configuration of the automated guided vehicle 10. As shown in Fig. 2, the automated guided vehicle 10 is configured with a running section 22 provided on the lower side of the vehicle body and a working section 23 provided on the upper side of the vehicle body.

[0018] Casters 31 are provided at the four corners of the bottom of the running part 22, and 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, causing the unmanned guided vehicle 10 to travel, and the wheels of each caster 31 are rotated accordingly. In addition, the travel drive motor 33 that rotates the drive wheel 32 is controlled separately for each drive wheel 32, adjusting the rotation speed of each drive wheel 32, and changing the traveling direction of the unmanned guided vehicle 10. In FIG. 2, the mechanism including the drive source of each drive wheel 32 is omitted from the illustration.

[0019] A pair of support walls 41 are disposed opposite each other and protrude from 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, and is supported by each support wall 41 via slide rails 43 so as to be slidable along the support wall 41. The distance between each arm 42 is set to a predetermined distance that is slightly longer than the width of the case CS transported by the conveyor device 11, making it possible to insert and clamp the case CS between the arms 42.

[0020] FIG. 3 is a perspective view showing the sliding state of each arm 42. Each arm 42 is slidably supported by two horizontally extending slide rails 43 relative to each support wall 41, and the movement direction is guided, and each arm 42 moves back and forth in its longitudinal direction. Each slide rail 43 has a configuration called a three-stage pull, for example, and has a configuration in which a part of it protrudes toward the outside, which is the side of the working unit 23, and moves. The slide rail 43 has a first rail, which is a part of it, 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 is guided in the movement direction by the first rail and moves to the outside, which is the side of the working unit 23. The second rail is attached to the arm 42. As a result, each arm 42 moves back and forth in the horizontal direction, and the entire arm 42 can perform an operation of protruding outward from the automatic guided vehicle 10 and being retracted into the automatic guided vehicle 10 from the protruding position.

[0021] As shown in Fig. 4, a rack gear 44 is provided at the lower end of each arm 42. Also, 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 guided in the moving direction by the slide rail 43 and moved back and forth. Note that the outward movement of the arm 42 in the moving direction is limited to a position where the arm 42 is not released from the lock and support by the support wall 41 and the slide rail 43, 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.

[0022] 2 and 3, a slit 42A is formed in a side surface portion on the inside (side facing the other opposing arm 42) of the tip of each arm 42, and a first claw portion 51 is provided that protrudes through the slit 42A into the space between each arm 42. A slit 42B is formed in a side surface portion on the inside (side facing the other opposing arm 42) of the rear end (base end) of each arm 42, and a second claw portion 52 is provided that protrudes through the slit 42B into the space between each arm 42.

[0023] As shown in Fig. 5, each first claw 51 is supported by a rotating shaft 53 inside the hollow housing-like arm 42, and each second claw 52 is supported by a rotating 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 Fig. 6) connected to each rotating shaft 53, and performs an action of protruding from slit 42A into the space between each arm 42 and an action of moving from the space to retract into arm 42. Each second claw 52 is rotated back and forth by a claw drive motor 56 (shown in Fig. 6) connected to each rotating shaft 54, and performs an action of protruding from slit 42B into the space between each arm 42 and an action of moving from the space to retract into arm 42.

[0024] As shown in Fig. 2 and Fig. 3, an imaging camera 71, such as a CCD, is provided on the working section 23. The imaging camera 71 is oriented so as to face the space above the first conveyor 11A when the unmanned guided vehicle 10 travels parallel to the first conveyor 11A along the first travel line 15A. In this embodiment, the imaging camera 71 is disposed on the base end side of each arm 42 at the center in the traveling direction of the unmanned guided vehicle 10 in the area sandwiched between the two support walls 41 on the working section 23. 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 transported on the first conveyor 11A. The imaging camera 71 may be disposed at a position on the base end side of each arm 42, on the outer side of one of the support walls 41 on the working unit 23 in the traveling direction of the automatic guided vehicle 10 (outside the area between the two support walls 41), or on an upper portion of one of the support walls 41, on the side wall side facing the other support wall 41. Furthermore, the imaging camera 71 may be disposed at another 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 the case CS transported on the first conveyor 11A.

[0025] 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 each travel drive motor 33 that rotates and drives each drive wheel 32 of the travel unit 22, each arm drive motor 45 that moves each arm 42 of the working unit 23 in the horizontal direction, each claw drive motor 55 that causes each first claw portion 51 to perform an operation of protruding from a slit 42A on the inner side of both ends of each arm 42 into the space between the arms 42 and an operation of retracting into the arm 42, each claw drive motor 56 that causes each second claw portion 52 to perform an operation of protruding from a slit 42B on the inner side of 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 a two-dimensional code Q attached to a case CS on the first conveyor 11A, a travel line sensor 72 that detects the travel line 15, a communication unit 73, and a control unit 74.

[0026] The communication unit 73 is a communication interface equipped with a communication module such as a LAN chip (not shown), and is connected to the terminal device 81 via a wired or wireless LAN to transmit and receive 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.

[0027] The control unit 74 includes 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). 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.

[0028] For example, the control unit 74 detects the position of the traveling line 15 based on the detection output of the traveling line sensor 72, and performs operation control such that, for each driving wheel 32, the control unit 74 drives and controls the traveling drive motor 33 of the driving wheel 32 to adjust the rotation speed of the driving wheel 32, thereby changing the traveling direction of the automated guided vehicle 10, and causes the automated guided vehicle 10 to travel along the traveling line 15 with the longitudinal direction of each arm 42 perpendicular to the traveling line 15. In addition, the control unit 74 adjusts the traveling speed V of the automated guided vehicle 10.

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

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

[0031] The unmanned transport vehicle 10 having such a configuration stops and waits at the standby position HP under the control of the control unit 74, and when the first conveyor 11A starts transporting the case CS, it travels parallel to the first conveyor 11A along the first traveling line 15A, while driving each arm 42, and transfers the case CS being transported by the first conveyor 11A to the unmanned transport vehicle 10. Furthermore, under the control of the control unit 74, the unmanned transport vehicle 10 travels along the first traveling line 15A → the second traveling line 15B → the third traveling line 15C, moves to the front of the storage shelf 12 and stops, transfers the case CS to the storage shelf 12, and travels along the third traveling line 15C → the fourth traveling line 15D → the first traveling line 15A, and returns to the standby position HP.

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

[0033] As shown in Fig. 1, while the automated guided vehicle 10 is waiting at the waiting position HP on the first travel line 15A, the second conveyor 11B starts to transport the case CS. The waiting position HP is set at the end of the second conveyor 11B, on 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 waiting position HP. The case CS that has been transported to the position shown by the dashed line in Fig. 1 is then transported by the first conveyor 11A, with the transport direction switched to the direction of the arrow shown in Fig. 1.

[0034] The unmanned guided vehicle 10 at the waiting position HP captures an image of the two-dimensional code Q of the case CS with the imaging camera 71 when the case CS is transported to the position indicated by the dashed line in Fig. 1. The imaging camera 71 of the unmanned guided vehicle 10 at the waiting position HP is provided in a position facing the two-dimensional code Q on the side of the case CS. The two-dimensional code Q includes identification information indicating an ID unique to the case CS. In the unmanned 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 is the same as the ID indicated by the identification information previously received from the terminal device 81 via the communication unit 73.

[0035] When the control unit 74 of the automated guided vehicle 10 determines that the above is the same, it starts the automated guided vehicle 10 traveling in the direction of the arrow shown in Fig. 1 (S101). At this point, the case CS has not changed its position and has started to be transported by the first conveyor 11A, and has already passed the position shown by the dashed line in Fig. 1, i.e., the standby position HP.

[0036] 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 the drive wheels 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 in parallel with the first conveyor 11A at a position close to the first conveyor 11A with the direction in which each arm 42 extends (the longitudinal direction of the arm 42) perpendicular to the traveling line 15, as shown in Fig. 8(A) (S102). At this time, the control unit 74 sets the traveling speed V of the unmanned guided vehicle 10 to a predetermined traveling speed VA that is faster than the transport speed VC of the case CS by the first conveyor 11A (S102).

[0037] In addition, the control unit 74 drives and controls one of the arm drive motors 45 to protrude one of the arms 42 located upstream in the transport direction of the case CS into the space above the first conveyor 11A as shown in Figure 8 (B) (S103).

[0038] At this time, the control unit 74 sets the running speed V of the unmanned guided vehicle 10 to the running speed VA that is faster than the transporting speed VC of the case CS by the first conveyor 11A, so that, as shown in Figures 8(B) and 9, one of the arms 42 located upstream in the transport direction of the case CS, which protrudes into the space above the first conveyor 11A, catches up with and comes into contact with the case CS.

[0039] Furthermore, a predetermined mark (such as a hole formed in the side surface or a predetermined image printed on the side surface; it may be a two-dimensional code Q) is provided on the side surface of the case CS facing the automatic guided vehicle 10. 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 comes into contact with the case CS, and therefore, when the one arm 42 catches up with and comes into contact with the case CS, the imaging camera 71 images the mark.

[0040] The control unit 74 acquires an image captured by the imaging camera 71, analyzes the image, and identifies an image showing the mark in the image (S104). Assuming that the one arm 42 has caught up with and contacted the case CS, the control unit 74 controls the driving of the arm driving motor 45 for driving the other arm 42 to protrude the other arm 42 located downstream in the conveying direction of the case CS into the space above the first conveyor 11A (S105), as shown in FIG. 10(A). The separation distance between the arms 42 is set to a distance slightly longer than the width of the case CS, which is equivalent to the width of the case CS, so that the protrusion of the other arm 42 causes the case CS to be sandwiched between the arms 42. In addition, each arm 42 protruded under the control of the control unit 74 has a length such that the tip of the arm 42 reaches a position beyond the rear end of the case CS in the direction perpendicular to the conveying direction of the case CS. 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 (FIGS. 10(A) and 11). Next, the control unit 74 controls the drive of each claw drive motor 55 to protrude the first claw portion 51 on the inside of the tip of each arm 42 (S106), as shown in FIG. 10(B) and FIG. 11.

[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 may indicate, for example, the weight of each of the contents and the number of the contents. The control unit 74 determines the weight of the contents based on the information, and calculates the weight of the item by adding the known weight of the case CS to the weight of the contents (S107). The information may indicate the weight of the item itself, which is the weight of the contents plus the known weight of the case CS. In this case, the control unit 74 obtains the weight of the item directly from the information. At this point, the control unit 74 drives and controls the travel drive motors 33 of the drive wheels 32 to travel the unmanned guided vehicle 10 at the travel speed VA set in S102. After S107, the control unit 74 compares the weight of the item calculated in S107 with a preset threshold value, and if it is determined that the weight of the item is less than the threshold value, it maintains the travel speed V of the unmanned guided vehicle 10 at the travel speed VA.

[0042] Furthermore, if the weight of the article is equal to or greater than the threshold value, the control unit 74 reduces the travel speed V of the automated guided vehicle 10 to a predetermined travel speed VD that is equal to or greater than the conveying speed VC of the case CS by the first conveyor 11A and is slower than the previous travel speed VA set in S102 (S108). As a result, if the weight of the article contained in the case CS is equal to or greater than the threshold value and is heavy, the travel speed V of the automated guided vehicle 10 is reduced while being maintained at or greater than the conveying speed VC of the case CS. Therefore, when the automated guided vehicle 10 is traveling while pushing the case CS with the protruding one arm 42, the load applied to each travel 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 automated guided vehicle 10 can travel stably.

[0043] Furthermore, the control unit 74 sets the rotation 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 rotation 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 corresponding rotation speed of each 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 rotation 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 rotation speed as the rotation 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, and as shown in FIG. 12, each arm 42 is withdrawn from the space above the first conveyor 11A and retracted from the protruding position as described above into the area within the working unit 23 of the unmanned guided vehicle 10. When each arm 42 is retracted, each first claw portion 51 hooks onto the end of the case CS, and each arm 42 retracts the case CS from the first conveyor 11A to the working unit 23 of the unmanned guided vehicle 10 (S110). That is, the retraction of each arm 42 moves the case CS from the position on the first conveyor 11A to the working unit 23 of the unmanned guided vehicle 10. As a result, the heavier the article, the slower the movement speed of each arm 42 is, and the case CS is transferred from the first conveyor 11A to the working unit 23 of the unmanned guided vehicle 10 at a slower speed. Therefore, it is possible to reduce the load on each arm drive motor 45 when each arm 42 pulls the case CS into the working section 23 of the unmanned guided vehicle 10. Furthermore, the movement of the case CS from its position on the first conveyor 11A to the working section 23 of the unmanned guided vehicle 10 is performed while the transportation by the first conveyor 11A and the running of the unmanned guided vehicle 10 are continuing, but since this movement is performed at a low speed, it is possible to stably and reliably move the case CS from its position on the first conveyor 11A to the working section 23 of the unmanned guided vehicle 10. Thereafter, the control unit 74 drives and controls each claw drive motor 55 to retract each first claw 51 and store it inside the arm 42.

[0045] In this manner, while the unmanned transport vehicle 10 travels parallel to the first conveyor 11A along the first travel line 15A, the case CS being transported by the first conveyor 11A is transferred from the first conveyor 11A to the unmanned transport vehicle 10.

[0046] Furthermore, the control unit 74 detects the position of the driving line 15 based on the detection output of the driving line sensor 72, and drives and controls the driving motors 33 of each drive wheel 32 according to the detected position of the driving line 15, so as to cause the unmanned guided vehicle 10 to travel along the route from the first driving line 15A to the second driving line 15B to the third driving line 15C (S111).

[0047] When the unmanned transport vehicle 10 travels to the position of the storage shelf 12, the two-dimensional code Q2 attached to each different position in the traveling direction of the unmanned transport vehicle 10 is captured by the imaging camera 71 on the storage shelf 12. The control unit 74 analyzes the captured two-dimensional code Q2 to detect the location information of the storage shelf 12 contained in the two-dimensional code Q2. The control unit 74 receives the location information of the storage shelf 12 linked to the ID in advance via the communication unit 73. When the two-dimensional code Q2 containing the location information matching the location information of the storage shelf 12 linked to the ID is captured, the control unit 74 stops the unmanned transport vehicle 10 at the position at this time, as shown in the example of FIG. 13 (S112). At this time, the unmanned transport vehicle 10 is in a position in which the tip of the arm 42 to which each first claw portion 51 is provided faces the storage shelf 12 side due to the direction change at each route change from the first traveling line 15A to the second traveling line 15B to the third traveling line 15C.

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

[0049] Next, the control unit 74 drives and controls each arm drive motor 45 to project each arm 42 towards the storage shelf 12 as shown in Figures 15 and 16 (S114). 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 such that the second rail is engaged and supported by the first rail, and the direction of movement is guided by the first rail, so that the second rail also moves in the outward direction toward the storage shelf 12 (the opposite direction to the outward direction toward the first conveyor 11A side shown in Figure 3).

[0050] As the arms 42 protrude towards the storage shelf 12, the second claws 52 hook onto the case CS, and the arms 42 and the second claws 52 push the case CS from above the working unit 23 of the automated guided vehicle 10 into the storage shelf 12, moving the case CS from above the working unit 23 of the automated guided vehicle 10 to the storage shelf 12. Thereafter, the control unit 74 drives and controls the claw drive motors 56 to retract the second claws 52 and store them inside the arms 42.

[0051] The control unit 74 detects the position of the driving line 15 based on the detection output of the driving line sensor 72, and drives and controls the driving motors 33 of each drive wheel 32 according to the detected position of the driving line 15 to make the unmanned guided vehicle 10 travel along the route from the third driving line 15C to the fourth driving line 15D to the first driving line 15A, and stops the driving motors 33 of each drive wheel 32 a certain time after the unmanned guided vehicle 10 changes its direction of travel by 90 degrees between the fourth driving line 15D and the first driving line 15A, thereby stopping the unmanned guided vehicle 10 at the waiting position HP (S115).

[0052] In this embodiment, when the first conveyor 11A starts transporting the case CS, the unmanned transport 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 transport direction is extended. At this time, the travel speed V of the unmanned transport vehicle 10 is set to a travel speed VA faster than the transport speed VS of the case CS, and when one arm 42 moves to the position of the case CS, the other arm 42 on the downstream side in the transport direction is extended. Then, the case CS is sandwiched between the arms 42. In this state, the first claw portion 51 on the inner tip of each arm 42 is extended, and each arm 42 is pulled back to the unmanned transport vehicle 10. At this time, each first claw portion 51 is caught by the case CS, and the case CS is pushed from the first conveyor 11A to the working unit 23 of the unmanned transport vehicle 10 by the arm 42 and the first claw portion 51, and moves onto the working unit 23 of the unmanned transport vehicle 10. As a result, according to this embodiment, while the unmanned guided vehicle 10 is traveling, the case CS being transported by the first conveyor 11A can be transferred to the unmanned guided vehicle 10, and the case CS can be moved efficiently. <Variation 1> In the first modification, the working unit 23 of the unmanned transport vehicle 10 moves up and down in the vertical direction. For example, a plurality of support pillars are provided protruding from the travelling unit 22 of the unmanned transport vehicle 10, and the working unit 23 is supported by the support pillars so as to be movable in the vertical direction, and the working unit 23 is lifted and lowered by a plurality of ball screws (known mechanisms). The ball screws include a screw shaft that is provided protruding from the travelling unit 22 and supported rotatably, and a nut that is fixed to the working unit 23 and screwed onto the screw shaft. The travelling unit 22 is provided with respective lifting motors that rotate the respective screw shafts, and under the control of the control unit 74, the respective lifting motors rotate the respective screw shafts in one direction to lift the respective nuts and the working unit 23, and the respective lifting motors rotate the respective screw shafts in the opposite direction to lower the respective nuts and the working unit 23. As a result, even if the heights of the conveyor device 11 and the storage shelves 12 change, the working section 23 can be raised and lowered to match this height, and the case CS can be transferred between the working section 23 and the conveyor device 11 or the storage shelves 12. <Variation 2> In the second modification, the separation distance between the arms 42 is changed. For example, one of the support walls 41 of the working unit 23 is supported so as to be slidable in a direction perpendicular to the longitudinal direction of the arms 42, a rack gear extending in the direction perpendicular to the lower end of one of the support walls 41 is provided, a pinion gear meshing with the rack gear is provided, and a motor for reciprocatingly rotating the pinion gear is provided in the working unit 23. Under the control of the control unit 74, the pinion gear is reciprocally rotated by the motor to reciprocate the rack gear, and one of the support walls 41 and the arm 42 is moved toward and away from the other support wall 41 and the arm 42, thereby changing the separation 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 unit 23 and the conveyor device 11 or the storage shelf 12.

[0053] 1 to 17 are merely one embodiment of the present invention, and the present invention is not limited to the configuration and processing. For example, in the above embodiment, the unmanned transport vehicle 10 takes in the case CS transported on the conveyor device 11 and stores it in the storage shelf 12, but 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 transport vehicle 10 takes in the case CS stored in the storage shelf 12 onto the unmanned transport vehicle 10, transports the case CS to the position of the conveyor device 11, and moves the case CS from the unmanned transport vehicle 10 onto the conveyor device 11. [Explanation of symbols]

[0054] 10. Automated Guided Vehicles 11 Conveyor equipment 12 Storage Shelves 15 Driving Line 22 Running part 23 Working Section 31 Caster 32 Drive wheels 41 Supporting wall 42 Arm 43 Slide rail 51 1st claw part 52 2nd claw part 33 Each driving motor 45 Arm drive motors 55 Each jaw drive motor 56 Each jaw drive motor 71 Imaging camera 72 Driving line sensor 73 Communications Department 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 that are provided at respective positions on the automated guided vehicle that are downstream and upstream in a conveying direction of the article by the conveyor when the automated guided vehicle travels along the conveyor, and that reciprocate in a direction perpendicular to the conveying direction of the article to protrude outward from the automated guided vehicle and are retracted into the automated guided vehicle from the protruding positions; an arm driving unit that causes each of the arms to reciprocate in the orthogonal direction; and a control unit that controls the travel drive unit and the arm drive unit to travel the unmanned transport vehicle along the conveyor at a travel speed faster than a transport speed of the article, and causes 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, causes the arm provided on the downstream side to protrude above the conveyor from the unmanned transport vehicle and retracts each arm 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 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 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. 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 that are provided at respective positions on the automated guided vehicle that are downstream and upstream in a conveying direction of the article by the conveyor when the automated guided vehicle travels along the conveyor, and that reciprocate in a direction perpendicular to the conveying direction of the article to protrude outward from the automated guided vehicle and are retracted into the automated guided vehicle from the protruding positions; an arm driving unit that causes each of the arms to reciprocate in the orthogonal direction; and a control unit that controls the travel drive unit and the arm drive unit to travel the unmanned transport vehicle along the conveyor at a travel speed faster than a transport speed of the item, and causes 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 item being transported by the conveyor, causes the arm provided on the downstream side to protrude above the conveyor from the unmanned transport vehicle and retracts each arm from above the conveyor into the unmanned transport vehicle.

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