Automated Guided Vehicle (AGV) System and Automated Guided 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

Technical Field

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

Background Art

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

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] By the way, when luggage is transported by a conveyor as in the technique disclosed in Patent Document 1 and the luggage is loaded onto an automated guided vehicle by a robot after the luggage arrives at the end of the conveyor, the time from the start of transporting the luggage by the conveyor to the loading of the luggage onto the automated guided vehicle becomes long, and the luggage is not efficiently moved.

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

[0006] This invention has been made in view of the above circumstances, and aims to efficiently move goods by enabling the transfer of goods from a conveyor to an automated guided vehicle (AGV) while the AGV travels along the conveyor, using a simple configuration.

[0007] An automated guided vehicle (AGV) system according to one aspect of the present invention comprises a conveyor for carrying and transporting articles, and an AGV that travels along the conveyor, wherein the AGV includes a drive wheel, a drive unit that rotates the drive wheel to move the AGV, a pair of arms provided at positions on the AGV that are downstream and upstream of the article transport direction when the AGV travels along the conveyor, extending in a direction perpendicular to the article transport direction, facing each other at a distance corresponding to the width of the article in the article transport direction, and configured to reciprocate in a perpendicular direction, enabling them to protrude outward from the AGV and be retracted into the AGV from the protruding position, an arm drive unit that causes each of the pair of arms to reciprocate, a pair of first claws provided at the tip of each of the pair of arms, and configured to protrude from the tip into the space between the pair of arms and retract into the tip, and a pair of first The system includes a first claw drive unit that causes each claw to either protrude or retract, and a control unit that controls the travel drive unit, the arm drive unit, and the first claw drive unit to make the automated guided vehicle (AGV) travel at a predetermined first travel speed faster than the transport speed of the goods, and when one arm provided on the downstream side in the transport direction of the goods passes the position of the downstream end of the goods being transported by the conveyor, it causes one arm to protrude from the AGV above the conveyor, and with one arm protruding, the AGV travels at a predetermined second travel speed slower than the transport speed of the goods, and when one arm moves to the position of the end of the goods being transported by the conveyor, it causes the other arm provided on the upstream side to protrude from the AGV above the conveyor, and with the goods present between the pair of arms, it causes a pair of first claws to protrude from the tips of the pair of arms into the space between the pair of arms, and pulls the pair of arms into the AGV from above the conveyor.

[0008] An automated guided vehicle (AGV) according to another aspect of the present invention includes: a drive wheel; a drive unit that rotates the drive wheel to move the AGV; a pair of arms provided at positions on the AGV that are downstream and upstream of the conveying direction of the articles when the AGV travels along a conveyor carrying articles, extending in a direction perpendicular to the conveying direction of the articles, facing each other at a distance corresponding to the width of the articles in the conveying direction of the articles, and configured to reciprocate in a perpendicular direction, enabling them to protrude outward from the AGV and be retracted into the AGV from the protruding position; an arm drive unit that causes each of the pair of arms to reciprocate; a pair of first claws provided at the tips of each of the pair of arms, configured to protrude into the space between the pair of arms and retract into the tips; and the ability to protrude and retract each of the pair of first claws. The system includes a first claw drive unit that causes the system to perform one of the following actions, and a control unit that controls the travel drive unit, the arm drive unit, and the first claw drive unit to make the automated guided vehicle (AGV) travel at a predetermined first travel speed faster than the transport speed of the goods, and when one arm provided on the downstream side in the transport direction of the goods passes the position of the downstream end of the goods being transported by the conveyor, it causes one arm to protrude from the AGV above the conveyor, and with one arm protruding, the AGV travels at a predetermined second travel speed slower than the transport speed of the goods, and when one arm moves to the position of the end of the goods being transported by the conveyor, it causes the other arm provided on the upstream side to protrude from the AGV above the conveyor, and with the goods present between the pair of arms, it causes a pair of first claws to protrude from the tips of the pair of arms into the space between the pair of arms, and pulls the pair of arms into the AGV from above the conveyor. [Effects of the Invention]

[0009] According to the present invention, with a simple configuration, it is possible to transfer items from a conveyor to an automated guided vehicle (AGV) while the AGV travels along the conveyor, thereby efficiently moving items. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic plan view showing an automated guided vehicle system according to one embodiment of the present invention. [Figure 2] This is a schematic perspective view of an automated guided vehicle (AGV). [Figure 3] This is a perspective view showing the sliding state of each arm of an automated guided vehicle (AGV). [Figure 4] This diagram schematically shows the rack gear and pinion gear used to move the arm back and forth. [Figure 5A] This is a perspective view showing the mechanism for extending and retracting the first and second claw portions of each arm. [Figure 5B] This is a plan view showing the mechanism for extending and retracting the first and second claw portions of each arm. [Figure 6] This is a block diagram showing the control system for an automated guided vehicle (AGV). [Figure 7A] This is a flowchart showing the control procedure for item movement processing. [Figure 7B] This is a flowchart showing the control procedure following Figure 7A. [Figure 8A] This is a perspective view showing the cases being transported by the first conveyor belt. [Figure 8B] This is a perspective view showing one arm of an automated guided vehicle (AGV) in contact with a case being transported by the first conveyor belt. [Figure 9] This is a perspective view showing one arm of an automated guided vehicle (AGV) in contact with a case being transported by the first conveyor belt. [Figure 10A] This is a perspective view showing a case being transported by the first conveyor belt being held between the arms of an automated guided vehicle (AGV). [Figure 10B] This is a perspective view showing the process of transferring cases being transported by the first conveyor belt to an automated guided vehicle (AGV). [Figure 11]It is a perspective view showing a state in which a case being conveyed by a first conveyor is sandwiched between each arm and a first claw portion inside the tip of each arm protrudes. [Figure 12] It is a perspective view showing an automated guided vehicle on which a case transferred from the first conveyor is placed. [Figure 13] It is a perspective view showing a state in which the automated guided vehicle has stopped in front of the storage shelf. [Figure 14] It is a perspective view showing a state in which a case is sandwiched between each arm of the automated guided vehicle and a second claw portion inside the rear end of each arm protrudes. [Figure 15] It is a perspective view showing a process of transferring a case from the automated guided vehicle to the storage shelf. [Figure 16] It is a perspective view showing the automated guided vehicle with the case transferred to the storage shelf. [Figure 17] It is a perspective view showing a state in which the case has been transferred from the automated guided vehicle to the storage shelf.

Mode for Carrying Out the Invention

[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 Sy according to an embodiment of the present invention. The automated guided vehicle system Sy includes an automated guided vehicle 10 and a conveyor device 11 for loading and transporting articles. The automated guided vehicle system Sy is provided indoors, such as in a warehouse equipped with a storage shelf 12.

[0013] The automated guided vehicle 10 travels automatically along a travel line 15 laid on the floor surface. For example, the travel line 15 is a magnetic tape attached to the floor surface. The automated guided vehicle 10 includes a magnetic sensor for detecting 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 the information obtained from the magnetic sensor, and performs steering control according to the position of the travel line 15 to make the automated guided vehicle 10 travel along the travel line 15.

[0014] Alternatively, the travel line 15 is a colored tape that is attached to the floor surface and has a different color or reflectivity from the floor surface. The automated guided vehicle 10 is equipped with an optical sensor such as a CCD that detects the colored tape. In the automated guided vehicle 10, the 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 make the automated guided vehicle 10 travel along the travel line 15.

[0015] Both the method using magnetic tape and magnetic sensors, and the method using color tape and optical sensors, are known technologies.

[0016] The conveyor system 11 includes a first conveyor 11A and a second conveyor 11B connected to one end of the first conveyor 11A. Both the first conveyor 11A and the second conveyor 11B are equipped with a plurality of rollers 16 arranged in parallel along the transport direction of the case CS (an example of an article).

[0017] Each roller 16 is pivotally supported on the frame of the first conveyor 11A or the second conveyor 11B by an axis perpendicular to the transport direction of the case CS. Each roller 16 is rotationally driven in one direction to transport the case CS on each roller 16. Belt conveyors may be used as the first conveyor 11A and the second conveyor 11B.

[0018] The travel line 15 includes 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 straight. The first travel line 15A extends parallel to the direction in which the first conveyor 11A extends (the direction in which the case CS is transported). 3 The travel line 15C passes near the storage rack 12.

[0019] The automated guided vehicle (AGV) 10 starts moving from a waiting position HP located near the beginning of the first travel line 15A and travels parallel to the first conveyor 11A along the first travel line 15A. At the end of the first travel line 15A, the AGV 10 changes direction by 90 degrees and moves to travel along the second travel line 15B. At the end of the second travel line 15B, the AGV 10 changes direction by 90 degrees and moves to travel along the third travel line 15C. The AGV 10 travels along the third travel line 15C to the storage rack 12, and at the end of the third travel line 15C, it changes direction by 90 degrees and moves to travel along the fourth travel line 15D. The unmanned transport vehicle 10 changes direction by 90 degrees at the end of the fourth travel line 15D and moves to travel along the first travel line 15A, returning to the waiting position HP near the starting end of the first travel line 15A.

[0020] Figure 2 is an enlarged, schematic perspective view of the automated guided vehicle 10. As shown in Figure 2, the automated guided vehicle 10 comprises a driving section 22 located on the lower side of the vehicle body and a working section 23 located on the upper side of the vehicle body.

[0021] Casters 31 are provided at each of the four corners of the bottom of the running section 22. Multiple drive wheels 32 are spaced apart on the inside of the bottom of the running section 22. Each drive wheel 32 is rotated by its own drive motor 33, and as the automated guided vehicle 10 moves, the wheels of each caster 31 rotate in response. The drive motor 33 that rotates each drive wheel 32 is controlled separately, and the rotation speed of each drive wheel 32 is adjusted. This adjustment changes the direction of travel of the automated guided vehicle 10.

[0022] The work section 23 includes a pair of support walls 41 that are positioned opposite each other and protrude from the upper surface of the work section 23. Each support wall 41 supports an arm 42 at its upper and outer side walls. Each arm 42 is, for example, hollow and casing-shaped. Each arm 42 is supported by each support wall 41 so as to be slidable along each support wall 41 via a slide rail 43. The distance between each arm 42 is set to a predetermined distance that is slightly longer than the width of the case CS being transported by the conveyor device 11. Each arm 42 can insert and clamp a case CS between itself and the arms 42.

[0023] Figure 3 is a perspective view showing the sliding state of each arm 42. Each arm 42 is slidably supported relative to each support wall 41 by two horizontally extending slide rails 43. Each arm 42 is guided in the direction of movement by the slide rails 43 and is capable of reciprocating movement in the longitudinal direction of each arm 42. Each slide rail 43 has a configuration, for example, referred to as a three-stage extension. Each slide rail 43 has a configuration in which a portion of it protrudes outward toward the side of the work section 23 and is movable.

[0024] The slide rail 43 has a first rail provided on the side wall of the support wall 41, and a second rail that is locked to and supported by the first rail and moves outwards to the side of the work section 23, guided in the direction of movement by the first rail. The second rail is attached to the arm 42. As a result, each arm 42 is configured to reciprocate horizontally, allowing the entire arm 42 to protrude outwards from the automated guided vehicle 10, and to be retracted into the automated 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 its own arm drive motor 45 (shown in Figure 6). A 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, the pinion gear 46 rotates back and forth, and each rack gear 44 and each arm 42 moves back and forth guided in the direction of movement by the slide rail 43.

[0026] Furthermore, the outward movement of the arm 42 is restricted to a position where the arm 42 is not released from the locking and support of the support wall 41 and the slide rail 43, as shown in Figure 3, by the engagement of the first and second rails of the slide rail 43 and the rotation control of the arm drive motor 45.

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

[0028] As shown in Figures 5A and 5B, each first claw portion 51 is supported by a rotating shaft 53 inside a hollow, housing-shaped arm 42. Each second claw portion 52 is supported by a rotating shaft 54 ​​inside a hollow, housing-shaped arm 42. Each first claw portion 51 is reciprocated by a claw drive motor 55 (shown in Figure 6) connected to each rotating shaft 53 to protrude from the slit 42A into the space between the arms 42 and to move out of that space and retract into the arms 42. Each second claw portion 52 is reciprocated by a claw drive motor 56 (shown in Figure 6) connected to each rotating shaft 54 ​​to protrude from the slit 42B into the space between the arms 42 and to move out of that space and retract into the arms 42.

[0029] As shown in Figures 2 and 3, an imaging camera 71, such as a CCD, is provided on the work section 23. The orientation of the imaging camera 71 is set so that when the automated guided vehicle 10 travels parallel to the first conveyor 11A along the first travel line 15A, the imaging camera 71 faces the space above the first conveyor 11A. In this embodiment, the imaging camera 71 is located on the work section 23 in the central part of the area between the two support walls 41 in the direction of travel of the automated guided vehicle 10, and is positioned on the base end side of each arm 42.

[0030] The imaging camera 71 captures images of a two-dimensional code (e.g., QR code®) Q or mark attached to a case CS being transported on the first conveyor belt 11A. The imaging camera 71 may be positioned on the base end side of each arm 42, outside one support wall 41 on the work section 23 (outside the area between the two support walls 41) in the direction of travel of the automated guided vehicle 10, or on the upper part of one support wall 41, on the side wall facing the other support wall 41. The imaging camera 71 may also be positioned at any other location, even if it is not on the base end side of each arm 42, as long as it is in a position where it can capture images of the two-dimensional code Q or mark attached to the case CS being transported on the first conveyor belt 11A.

[0031] Figure 6 is a block diagram showing the control system of the automated guided vehicle 10. As shown in Figure 6, the automated guided vehicle 10 includes each travel drive motor 33, each arm drive motor 45, each claw drive motor 55, each claw drive motor 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 each drive wheel 32 of the travel unit 22. Each arm drive motor 45 moves each arm 42 of the work unit 23 horizontally. Each claw drive motor 55 moves each arm 42 relative to each first claw unit 51. destination The mechanism allows the arm to protrude from the inner end slit 42A into the space between each arm 42 and to retract into the arm 42.

[0033] Each claw drive motor 56 controls each second claw portion 52 of each arm 42 rear The mechanism is designed to extend from the inner end slit 42B into the space between each arm 42 and to retract into the arm 42. The imaging camera 71 captures images 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 with 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, RAM (Random Access Memory), ROM (Read Only Memory), and dedicated hardware circuitry. 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 comprehensively controls the automated guided vehicle 10 through the operation of the processor in accordance with the 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 motor 33 of each drive wheel 32 according to the detected position of the travel line 15, thereby adjusting the rotational speed of the drive wheels 32. By adjusting the rotational speed, the control unit 74 changes the direction of travel of the automated guided vehicle 10 so that the automated guided vehicle 10 travels 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 move each arm 42 back and forth. The control unit 74 drives and controls each claw drive motor 55, 56 to make each claw portion 51, 52 protrude from the respective slits 42A, 42B formed at both ends of each arm 42, or to retract into the arm 42. The control unit 74 also acquires images captured by the imaging camera 71, analyzes the images, and identifies the two-dimensional code Q contained in the images.

[0038] The automated guided vehicle (AGV) 10, under the control of the control unit 74, stops and waits at the standby position HP. When the transport of cases CS by the first conveyor 11A begins, the AGV 10 travels parallel to the first conveyor 11A along the first travel line 15A, driving each arm 42 to transfer the cases CS being transported by the first conveyor 11A to the AGV 10. Under the control of the control unit 74, the AGV 10 travels in the order of first travel line 15A, second travel line 15B, and third travel line 15C, moving to the front of the storage rack 12 and stopping. Under the control of the control unit 74, the AGV 10 transfers the cases CS to the storage rack 12, and then travels in the order of third travel line 15C, fourth travel line 15D, and first travel line 15A, returning to the standby position HP.

[0039] Next, the control procedure for transferring the case CS being transported by the first conveyor 11A to the automated guided vehicle 10, and then moving the case CS using the automated guided vehicle 10, will be explained in detail with reference to the flowcharts shown in Figures 7A and 7B.

[0040] As shown in Figure 1, the second conveyor 11B begins transporting the case CS while the automated guided vehicle 10 is waiting at the waiting position HP on the first travel line 15A. The waiting position HP is located on the side of the end of the second conveyor 11B, where it connects to the first conveyor 11A (the starting end of the first conveyor 11A). The case CS on the second conveyor 11B is transported with the attached 2D code Q facing the waiting position HP. Once the case CS has been transported to the position shown by the dashed line in Figure 1, the first conveyor 11A then switches its transport direction in the direction of the arrow shown in Figure 1 and continues transporting it.

[0041] The automated guided vehicle (AGV) 10, located at the standby position HP, captures the 2D code Q of the case CS using its imaging camera 71 when the case CS has been transported to the position indicated by the dashed line in Figure 1. The imaging camera 71 of the AGV 10 at the standby position HP is positioned to face the 2D code Q on the side of the case CS. The 2D code Q contains identification information that indicates the unique ID of the case CS. In the AGV 10, the control unit 74 analyzes the 2D code Q captured by the imaging camera 71 and determines whether the ID indicated by the identification information contained in the 2D code Q is the same as the ID indicated by the 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 met, it starts the unmanned transport 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 its orientation. 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 travel line 15 based on the detection output of the travel line sensor 72, and controls the drive motors 33 of each drive wheel 32 according to the detected position of the travel line 15, so that the unmanned transport vehicle 10 moves along the first travel line 15A, parallel to the first conveyor 11A, and in close proximity to the first conveyor 11A, with the direction in which each arm 42 extends (the longitudinal direction of the arm 42) perpendicular to the travel line 15, as shown in Figure 8A.

[0044] At this time, the control unit 74 sets the travel speed V of the automated 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 automated guided vehicle 10 is set to a predetermined travel speed VA that is faster than the transport speed VS of the case CS by the first conveyor 11A, one arm 42 located further downstream in the transport direction of the case CS passes the position of the downstream end of the case CS being transported by the first conveyor 11A.

[0045] A predetermined mark (for example, a hole formed on the side of the case CS facing the automated guided vehicle 10, or a predetermined image printed on it; this may also be a 2D code Q) is provided on the side of the case CS. The imaging camera 71 is positioned so as one arm 42, located downstream in the transport direction, overtakes the case CS and can capture the side of the case CS. The imaging camera 71 captures the mark at the point when one arm 42 is overtaking the case CS.

[0046] The control unit 74 acquires the image captured by the imaging camera 71, analyzes the image, and identifies the image containing the mark (step S103). The control unit 74 starts timing the elapsed time from the time the mark was identified, and when the elapsed time reaches a certain period, it determines that one of the arms 42 located on the downstream side has moved beyond the position of the downstream end in the transport direction of the case CS being transported by the first conveyor 11A (step S104).

[0047] The control unit 74 drives one of the two arm drive motors 45 to make one of the arms 42 located downstream in the transport direction of the case CS protrude into the space above the first conveyor 11A, as shown in Figures 8B and 9 (step S105). The control unit 74 drives the travel drive motor 33 of the drive wheel 32 to set the travel speed V of the automated guided vehicle 10 to a predetermined travel 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 automated guided vehicle 10 is set to a travel speed VB that is slower than the transport speed VS of the case CS by the first conveyor 11A, one arm 42 located further downstream in the transport direction catches up to the case CS and makes contact with it. That is, the one arm 42 located downstream 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 the second speed control described below. The two-dimensional code Q identified in step S103 includes weight information indicating the weight of the contents contained in case CS. The weight information may indicate the weight itself, or it may indicate, for example, the weight of an individual item and the number of items. After processing in step S103 and before processing in step S106, the control unit 74 determines the weight of the contents based on the weight information and calculates the weight of the items by adding the known weight of case CS to the weight of the contents. Note that the weight information may indicate the weight of the items themselves, which is the weight of the items plus the known weight of case CS. In this case, the control unit 74 obtains the weight of the items directly from the weight information.

[0050] At the time step S105 is completed, the control unit 74 controls the drive motors 33 of each drive wheel 32 to move the automated guided vehicle 10 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 predetermined threshold, it sets the travel speed V of the automated guided vehicle 10 to the above travel speed VB (step S106).

[0051] If the weight of the items is above the threshold, the control unit 74 sets the travel speed V of the automated guided vehicle 10 to a predetermined adjusted travel speed VD that is faster than the travel speed VB and less than or equal to the transport speed VS of the case CS (step S106). In this way, by setting the travel speed V of the automated guided vehicle 10 to the adjusted travel speed VD, when the weight of the items contained in the case CS is above the threshold and heavy, the travel speed V of the automated guided vehicle 10 will be slower than the transport speed VS of the case CS, but the speed difference with the transport speed VS will be small.

[0052] As a result, when the automated guided vehicle 10 is traveling with one of its downstream arms 42 being pushed by the case CS, the load on each travel drive motor 33 can be reduced, and the load from the case CS on the downstream arm 42 can also be reduced. Therefore, the automated guided vehicle 10 can be operated stably.

[0053] After step S106, when the automated guided 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 identifies the two-dimensional code Q contained in the image again (step S107).

[0054] When the case CS is identified again, the control unit 74 assumes that one arm 42 located on the downstream side has moved to the position of the end of the case CS being transported by the first conveyor 11A, and controls the arm drive motor 45 for driving the other arm 42 located on the upstream side in the transport direction of the case CS, causing the other arm 42 located on the upstream side 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 spacing between each arm 42 is set to a distance slightly longer than the width of the case CS, and equivalent to the width of the case CS. Therefore, the case CS is inserted and sandwiched between the arms 42 due to the protrusion of the other arm 42. Each arm 42 has a length such that, due to the protrusion controlled by the control unit 74, the tip of each arm 42 reaches a position beyond the rear end of the case CS in a direction perpendicular to the transport direction of the case CS. The control unit 74 causes each arm 42 to protrude until the tip of each arm 42 reaches a position beyond the aforementioned rear end of the case CS (Figures 10A and 11).

[0056] Furthermore, after the processing in step S108, the control unit 74 may drive the drive motors 33 of each drive wheel 32 to make the unmanned transport vehicle 10 travel at the same speed VB (or adjusted travel speed VD) as the transport speed VS of the case CS by the first conveyor 11A.

[0057] Next, the control unit 74 drives and controls each claw drive motor 55 to make the first claw portion 51 on the inside of the tip of each arm 42 protrude, as shown in Figures 10B and 11 (step S109). At this point, 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 between the processing in step S103 and the processing in step S112 (step S110).

[0058] Furthermore, after step S110, the control unit 74 may set the travel speed V of the automated 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 item (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 item increases. For example, the control unit 74 stores in its built-in ROM a data table that shows the weight of the item and the rotation speed of each arm drive motor 45 corresponding to the weight of the item for each item. The control unit 74 reads the rotation speed of each arm drive motor 45 corresponding to the calculated weight of the item from the data table and sets the read rotation speed as the rotation speed of each arm drive motor 45 according to the calculated weight of the item.

[0060] The control unit 74 drives and controls each arm drive motor 45 to rotate each arm drive motor 45 at the rotational speed set in step S112, and as shown in Figure 12, moves each arm 42 out of the space above the first conveyor 11A and pulls it into the area within the work section 23 of the automated guided vehicle 10 from the position where it was protruding as described above. When each arm 42 is pulled in, each first claw portion 51 catches on the end of the case CS, and each arm 42 pulls the case CS from the first conveyor 11A into the work section 23 of the automated guided vehicle 10 (step S113).

[0061] In other words, the retraction of each arm 42 moves the case CS from its position on the first conveyor 11A to the work section 23 of the automated guided vehicle 10. Thus, the heavier the item, the slower the movement speed of each arm 42 is made, and the case CS is transferred from the first conveyor 11A to the work section 23 of the automated guided vehicle 10 at a slow speed. As a result, the load on each arm drive motor 45 can be reduced when each arm 42 retracts the case CS into the work section 23 of the automated guided vehicle 10.

[0062] Furthermore, the movement of case CS from its position on the first conveyor 11A to the work section 23 of the automated guided vehicle 10 is performed while the first conveyor 11A and the automated guided vehicle 10 continue to move. However, since this movement is performed at a low speed, case CS can be moved stably and reliably from its position on the first conveyor 11A to the work section 23 of the automated guided vehicle 10.

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

[0064] 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 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 the first travel line 15A, the second travel line 15B, and the third travel line 15C in that order (step S114).

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

[0066] When the control unit 74 captures a 2D code containing location information that matches the location information of the storage shelf 12 linked to the above ID, it stops the automated guided vehicle 10 at that position, as shown in Figure 13 (step S115). At this time, the automated guided vehicle 10 is in a position where the tips of the arms 42, each equipped with a first claw portion 51, are facing toward the storage shelf 12 due to the change in direction when changing the route of the first travel line 15A, the second travel line 15B, and the third travel line 15C.

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

[0068] The control unit 74 drives and controls each arm drive motor 45 to make each arm 42 protrude toward the storage shelf 12, as shown in Figures 15 and 16 (step S117). The amount of protrusion at this time is such that the second claw portion 52 on the inside of the rear end of each arm 42 can enter at least above the storage shelf 12. The slide rail 43 is configured such that the second rail moves outward toward the storage shelf 12 (opposite to the outward toward the first conveyor 11A shown in Figure 3) guided by the first rail by the locking and support of the first rail.

[0069] The control unit 74 uses the projection of each arm 42 toward the storage shelf 12 to hook each second claw portion 52 onto the case CS, and the arms 42 and second claw portions 52 push the case CS into the storage shelf 12 from above the work section 23 of the automated guided vehicle 10, thereby moving the case CS from above the work section 23 of the automated 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 portion 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 controls the 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 the third travel line 15C, the fourth travel line 15D, and the first travel line 15A in that order. The control unit 74 changes the direction of travel by 90 degrees between the fourth travel line 15D and the first travel line 15A, and after a certain period of time, stops the drive motors 33 of each drive wheel 32, causing the automated guided vehicle 10 to stop at the standby position HP (step S118).

[0071] Thus, in this embodiment, when the first conveyor 11A starts transporting the case CS, the automated guided vehicle 10 travels parallel to the first conveyor 11A along the first travel line 15A, and the travel speed V of the automated 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 subsequently the travel speed V of the automated 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 makes contact with the end of case CS, the other arm 42 on the upstream side in the conveying direction protrudes, and case CS is sandwiched between the arms 42. In this state, the first claw portion 51 on the inside of the tip of each arm 42 protrudes, and each arm 42 is pulled back towards the automated guided vehicle 10. At this time, each first claw portion 51 catches on case CS, and the arms 42 and the first claw portions 51 push case CS from the first conveyor 11A to the work section 23 of the automated guided vehicle 10, and it moves onto the work section 23 of the automated guided vehicle 10.

[0073] According to this embodiment, while the automated guided vehicle 10 is in motion, the cases CS being transported by the first conveyor 11A can be transferred to the automated guided vehicle 10, thereby efficiently moving the cases CS.

[0074] <First variation> In the first modified example, the work section 23 of the automated guided vehicle 10 moves up and down vertically. For example, multiple support columns are provided protruding from the running section 22 of the automated guided vehicle 10, and the work section 23 is supported by each support column so as to be movable in the vertical direction, and the work section 23 is moved up and down by multiple ball screws, which is a known mechanism. The ball screw comprises a screw shaft that is provided protruding from the running section 22 and is supported so as to be rotatable, and a nut that is fixed to the work section 23 and screwed onto the screw shaft.

[0075] The travel unit 22 is equipped with a lifting motor that rotates each screw shaft. The control unit 74 rotates each screw shaft in one direction relative to each lifting motor to raise each nut and work unit 23. The control unit 74 also rotates each screw shaft in the opposite direction relative to each lifting motor to lower each nut and work unit 23. According to the first modified example, even if the height of the conveyor device 11 and the storage shelf 12 changes, the work unit 23 can be raised and lowered to match the height of the conveyor device 11 and the storage shelf 12, making it possible to transfer the case CS between the work unit 23 and the conveyor device 11 or the storage shelf 12.

[0076] <Second variation> In the second modification, the spacing between each arm 42 is changed. For example, in the work section 23, one of the support walls 41 is slidably supported in a direction perpendicular to the longitudinal direction of each arm 42, and a rack gear extending in the perpendicular direction is provided at the lower end of one of the support walls 41. Furthermore, a pinion gear that meshes with the rack gear and a motor that reciprocates the pinion gear are provided in the work section 23.

[0077] The control unit 74 controls the motor to reciprocate the pinion gear, thereby moving the rack gear back and forth. This causes one support wall 41 and arm 42 to move closer to and further away from the other support wall 41 and arm 42, changing the distance between each arm 42. According to the second modified example, even if the width of the case CS changes, the case CS can be sandwiched between each arm 42, making it possible to move the case CS between the work section 23 and the conveyor device 11 or storage rack 12.

[0078] The configuration and processing of the above embodiment described with reference to Figures 1 to 17 are merely one embodiment of the present invention, and the present invention is not intended to be limited to such configuration and processing. For example, in the above embodiment, the automated guided vehicle 10 takes in the cases CS being transported by the conveyor device 11 and stores them in the storage rack 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, arm drive motor 45, claw drive motor 55, and claw drive motor 56 to operate the arm 42, first claw portion 51, second claw portion 52, and imaging camera 71, so that the automated guided vehicle 10 can pick up the cases CS stored in the storage rack 12 onto the automated guided vehicle 10, transport the cases CS to the position of the conveyor device 11, and perform the operation of moving the cases CS from the automated guided vehicle 10 onto the conveyor device 11.

Claims

1. A conveyor belt that carries and transports goods, The system includes an automated guided vehicle that travels along the aforementioned conveyor, The aforementioned unmanned transport vehicle is Drive wheels and A drive unit that rotates the drive wheels to move the automated guided vehicle, A pair of arms are provided on the automated guided vehicle (AGV) at positions on the downstream and upstream sides of the conveying direction of the article when the AGV travels along the conveyor, extending in a direction perpendicular to the conveying direction of the article, facing each other at a distance corresponding to the width of the article in the conveying direction of the article, and configured to reciprocate in the perpendicular direction, enabling them to project outward from the AGV and be retracted into the AGV from the projected position, An arm drive unit that causes each of the pair of arms to perform the reciprocating movement, A pair of first claws are provided at the tip of each of the pair of arms and are configured to be able to protrude from the tip into the space between the pair of arms and to retract into the tip, A first claw drive unit that causes each of the pair of first claw portions to perform either the protruding action or the retracting action, The travel drive unit, the arm drive unit, and the first claw drive unit are controlled, The automated guided vehicle is driven at a predetermined first travel speed that is faster than the transport speed of the article, and when one arm provided on the downstream side in the transport direction of the article passes the position of the downstream end of the article being transported by the conveyor, the one arm is made to protrude from the automated guided vehicle upwards from the conveyor. With one of the arms extended, the automated guided vehicle is driven at a predetermined second travel speed that is slower than the transport speed of the item. When one of the arms moves to the position of the end of the article being transported by the conveyor, the other arm provided on the upstream side is made to protrude from the automated guided vehicle upwards above the conveyor. An automated guided vehicle system comprising: a control unit that, with the article present between the pair of arms, causes the pair of first claws to protrude from the tips of the pair of arms into the space between the pair of arms, and causes the pair of arms to be retracted into the automated guided vehicle from above the conveyor.

2. The automated guided vehicle system according to claim 1, wherein the control unit extends the other arm and then causes the automated guided vehicle to travel at the same speed as the conveying speed of the articles by the conveyor.

3. A predetermined mark is attached to a predetermined position on the aforementioned article. The aforementioned unmanned transport vehicle further comprises an imaging unit that images the space above the conveyor, The automated guided vehicle system according to claim 1, wherein the control unit analyzes an image captured by the imaging unit when the automated guided vehicle is traveling at a first travel speed, and determines that one of the arms has moved to a position beyond the end of the article being transported by the conveyor when a predetermined period of time has elapsed since the control unit determined that the image contains an image showing the mark based on the analysis.

4. A predetermined mark is attached to a predetermined position on the aforementioned article. The aforementioned unmanned transport vehicle further comprises an imaging unit that images the space above the conveyor, The automated guided vehicle system according to claim 1, wherein the control unit analyzes an image captured by the imaging unit when the automated guided vehicle is traveling at the second travel speed, and determines that the image contains an image showing the mark based on the analysis, and determines that one arm has moved to the position of the end of the article being transported by the conveyor.

5. The mark is a two-dimensional code containing weight information indicating the weight of the article. The control unit controls the travel drive unit to maintain the second travel speed as is, if the weight of the item indicated by the weight information is less than a threshold. The automated guided vehicle system according to claim 3, wherein if the weight of the article is greater than or equal to the threshold, the second travel speed is changed to a predetermined adjusted travel speed that is faster than the second travel speed but less than or equal to the transport speed of the article, and the automated guided vehicle is driven.

6. The mark is a two-dimensional code containing weight information indicating the weight of the article. The automated guided vehicle system according to claim 3, wherein the control unit controls the arm drive unit to reduce the speed at which the pair of arms move when they are pulled into the automated guided vehicle from the space above the conveyor, as the weight of the article indicated by the weight information increases.

7. A pair of second claws are provided at the rear ends of each of the pair of arms and are configured to be able to protrude from the rear end into the space between the pair of arms and to retract into the interior of the rear end, The device further comprises a second claw drive unit that causes each of the pair of second claw portions to perform either the protruding action or the retracting action, The unmanned transport 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 claws to protrude from the rear ends of the pair of arms into the space between the pair of arms, thereby causing the pair of arms to protrude outward from inside the unmanned transport vehicle.

8. A rack gear extending in the orthogonal direction supports one of the arms or the other arm so as to be slidable in a direction perpendicular to the longitudinal direction of the pair of arms, A pinion gear that meshes with the aforementioned rack gear, The system further comprises a motor that reciprocates the aforementioned pinion gear, The unmanned transport vehicle system according to claim 1, wherein the control unit reciprocates the pinion gear by using the motor to rotate the rack gear, thereby changing the distance between the pair of arms.

9. Drive wheels and A drive unit that rotates the drive wheels to move the unmanned transport vehicle, A pair of arms are provided on the automated guided vehicle (AGV) at positions on the downstream and upstream sides of the conveying direction of the AGV when the AGV travels along a conveyor that carries and transports an item, extending in a direction perpendicular to the conveying direction of the item, facing each other at a distance corresponding to the width of the item in the conveying direction of the item, and configured to reciprocate in the perpendicular direction, enabling them to project outward from the AGV and be retracted into the AGV from the projected position, An arm drive unit that causes each of the pair of arms to perform the reciprocating movement, A pair of first claws are provided at the tip of each of the pair of arms and are configured to be able to protrude from the tip into the space between the pair of arms and to retract into the tip, A first claw drive unit that causes each of the pair of first claw portions to perform either the protruding action or the retracting action, The travel drive unit, the arm drive unit, and the first claw drive unit are controlled, The automated guided vehicle is driven at a predetermined first travel speed that is faster than the transport speed of the article, and when one arm provided on the downstream side in the transport direction of the article passes the position of the downstream end of the article being transported by the conveyor, the one arm is made to protrude from the automated guided vehicle upwards from the conveyor. With one of the arms extended, the automated guided vehicle is driven at a predetermined second travel speed that is slower than the transport speed of the item. When one of the arms moves to the position of the end of the article being transported by the conveyor, the other arm provided on the upstream side is made to protrude from the automated guided vehicle upwards above the conveyor. An automated guided vehicle comprising: a control unit that, with the article present between the pair of arms, causes the pair of first claws to protrude from the tips of the pair of arms into the space between the pair of arms, and causes the pair of arms to be retracted into the automated guided vehicle from above the conveyor.

10. A pair of second claws are configured to be able to protrude from the rear end of each of the pair of arms into the space between the pair of arms and to retract into the rear end, The device further includes a second claw drive unit that causes each of the pair of second claw portions to perform either the protruding or retracting operation, The control unit, after transferring the article from the conveyor to the automated guided vehicle, 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 preset position, causes the pair of second claws to protrude from the rear ends of the pair of arms into the space between the pair of arms, pushes the pair of arms out of the automated guided vehicle to the preset position, hooks the pair of second claws onto the article, and transfers the article from the automated guided vehicle to the preset position, as described in claim 9.

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