Unmanned transport vehicle

Abstract

This unmanned transport vehicle travels along a prescribed travel path, loads an article thereonto by using an arm (15-1), and transports the article. A claw part (21) is provided to an arm surface (15-1a) situated on the leading end portion of the arm (15-1) and facing an accommodation section, and the claw part (21) supports the article when loading the article. The claw part (21) is provided with: a substantially plate-shaped claw member (31) that is disposed so as to be capable of turning about a turn axis and within a prescribed angle range; and an elastic member (32) that biases the claw member (31) such that the claw member (31) projects from the arm surface (15-1a).

Description

Automated guided vehicle

[0001] The present invention relates to an automated guided vehicle.

[0002] A certain automated guided vehicle includes two arms each having a claw portion that can be extended and retracted at each tip, and (a) travels parallel to the conveyance direction of the article being conveyed by a conveyor at a speed higher than the conveyance speed of the article, (b) extends the arm on the upstream side of the travel route, and extends the arm on the downstream side when the upstream arm has moved to the position of the article, (c) when there is an article between the two arms, electrically controls to project the claw portion, and (d) retracts the two arms while bringing the claw portion into contact with the article, thereby pulling the article into the automated guided vehicle (see, for example, Patent Document 1).

[0003] Patent No. 7448894

[0004] However, in the above-described automated guided vehicle, since the claw portion is extended and retracted by electrical control, a driving device such as a motor for electrically driving the claw portion is required.

[0005] The present invention has been made in view of the above problems, and an object thereof is to obtain an automated guided vehicle that does not require an electrical driving device for the claw portion provided on the arm.

[0006] The automated guided vehicle according to the present invention is an automated guided vehicle that travels along a predetermined travel route and accommodates and conveys articles, and includes a storage portion in which the articles are accommodated, an arm, an arm drive system that moves the arm in a predetermined direction from the automated guided vehicle and returns the arm to the automated guided vehicle in order to accommodate the articles, and a claw portion provided on an arm surface facing the storage portion at a tip portion of the arm and supporting the articles when the articles are accommodated. The claw portion includes a substantially plate-shaped claw member that is rotatably arranged within a predetermined angular range about a rotation axis, and an elastic member that biases the claw member to project from the arm surface.

[0007] According to the present invention, an automated guided vehicle that does not require an electrical driving device for the claw portion provided on the arm can be obtained.

[0008] The above or other objects, features, and advantages of the present invention will become even more apparent from the following detailed description in conjunction with the accompanying drawings.

[0009] Figure 1 is a diagram illustrating the configuration of an automated guided vehicle (AGV) system according to an embodiment of the present invention. Figure 2 is a perspective view showing an example of the AGV 1 in Figure 1. Figure 3 is a diagram illustrating the operation of the arm of the AGV 1 shown in Figure 2. Figure 4 is a top view showing an example of the configuration of the claw portion 21 in Figures 2 and 3. Figure 5 is a diagram illustrating the operation of the claw portion 21 when the arm 15-1 moves (1 / 2). Figure 6 is a diagram illustrating the operation of the claw portion 21 when the arm 15-1 moves (2 / 2). Figure 7 is a block diagram illustrating the electrical configuration of the AGV 1 shown in Figure 2. Figure 8 is a diagram illustrating the operation of the AGV 1 in Embodiment 1 (1 / 2). Figure 9 is a diagram illustrating the operation of the AGV 1 in Embodiment 1 (2 / 2).

[0010] Embodiments of the present invention will be described below with reference to the figures.

[0011] Embodiment 1.

[0012] Figure 1 is a diagram showing the configuration of an automated guided vehicle (AGV) system according to an embodiment of the present invention. The AGV system shown in Figure 1 comprises an AGV 1, a conveyor 2, and a storage rack 3. The AGV 1 travels along a predetermined travel path, picks up and transports articles 101 being transported along the predetermined transport path, and delivers the articles 101 to the storage rack 3, which is the destination. The conveyor 2 is a roller conveyor or the like, laid along the transport path of the articles 101, and transports the articles 101 at a constant transport speed along the transport path. The travel path may be set virtually by the AGV 1 or a server (not shown) (i.e., by floor patterns unique to each position without placing members such as markers), or it may be set physically by members such as markers. The above-mentioned travel path and the above-mentioned transport path are partially parallel, and the articles 101 are picked up by the AGV 1 in the parallel portion.

[0013] Furthermore, item 101 is placed in packaging materials or cases such as cardboard boxes, and has a roughly rectangular parallelepiped shape in appearance.

[0014] Figure 2 is a perspective view showing an example of the automated guided vehicle (AGV) 1 in Figure 1. For example, as shown in Figure 2, the AGV 1 comprises a housing 11, the lower surface 11a of the housing 11 is equipped with a plurality of casters 12 (driven wheels) and a plurality of drive wheels 13 as a running system, and the upper surface 11b of the housing 11 is equipped with rails 14-1, 14-2 and arms 15-1, 15-2 as arm sections. Furthermore, the AGV 1 is equipped with an imaging device 16 on the upper surface 11b. The upper surface 11b is used as a storage section in which an article 101 is stored.

[0015] Each of the multiple drive wheels 13 is controlled independently, and the amount and direction of rotation of each wheel is used to move the unmanned transport vehicle 1 in a straight line or to turn.

[0016] Figure 3 is a diagram illustrating the operation of the arms of the automated guided vehicle 1 shown in Figure 2. For example, as shown in Figure 3, arms 15-1 and 15-2 are flat plate-shaped members arranged on rails 14-1 and 14-2. Rails 14-1 and 14-2 have a substantially flat shape and incorporate the arm drive system described later, which moves arms 15-1 and 15-2 in a straight line. In this embodiment, arms 15-1 and 15-2 move along a direction substantially perpendicular to the direction of travel. The arm drive system is, for example, a rack and pinion mechanism and motor, or a linear motor. Arm 15-1 is the upstream arm in the travel path of the automated guided vehicle 1 on the upper surface 11b which is the housing section, and arm 15-2 is the downstream arm in the travel path of the automated guided vehicle 1 on the upper surface 11b which is the housing section.

[0017] Furthermore, each arm 15-i (i=1,2) is equipped with a claw portion 21 at its tip and a claw portion 22 at its rear end.

[0018] The claw portion 21 is provided on the arm surface 15ia facing the storage portion (upper surface 11b) at the tip of the arm 15-i, and supports the article 101 when storing the article 101.

[0019] Figure 4 is a top view showing an example of the configuration of the claw portion 21 in Figures 2 and 3. For example, as shown in Figure 4, the claw portion 21 comprises a claw member 31 and an elastic member 32. The claw member 31 is a substantially plate-shaped member that is rotatable within a predetermined angular range around a pivot axis 31a. The elastic member 32 is a member that biases the claw member 31 to protrude from the arm surface 15-ia, and in this case, it is a torsion coil spring. When the article 101 is not in contact with the claw member 31, the elastic member 32 causes the claw member 31 to protrude to the limit angle of its angular range.

[0020] Figures 5 and 6 illustrate the operation of the claw portion 21 when the arm 15-1 moves. The claw member 31 has (a) a first surface 31b and a second surface 31c facing each other, as shown in Figure 4, for example; (b) when the arm 15-1 moves from the automated guided vehicle 1 in a predetermined direction (towards the transport path) by the arm drive system, the article 101 is housed inside the arm 15-1 against the elastic member 32 when it comes into contact with the first surface 31b, as shown in Figure 5, for example; (b) when the article 101 is not in contact with the first surface 31b of the claw member 31, it is rotated by the elastic member 32 to a predetermined angle (here, approximately perpendicular to the arm surface 15-1a), as shown in Figure 6, for example; and (c) when the arm 15-1 returns to the automated guided vehicle 1 (from the transport path) together with the article 101 by the arm drive system, the article 101 is supported by the second surface 31c.

[0021] Although Figures 4 to 6 show the claw portion 21 of arm 15-1, the claw portion 21 of arm 15-2 and the claw portions 22 of arms 15-1 and 15-2 have a similar configuration. However, the rotation direction of the claw member 31 from the arm surfaces 15-1a and 15-2a is set as shown in Figure 3, for example.

[0022] Furthermore, the imaging device 16 is equipped with an image sensor such as a CCD (Charge Coupled Device) and captures an image of the area in front of the housing section (upper surface 11b) (i.e., a predetermined range on the conveyor 2) to generate an image.

[0023] Figure 7 is a block diagram showing the electrical configuration of the automated guided vehicle 1 shown in Figure 2. For example, as shown in Figure 7, the automated guided vehicle 1 includes a travel sensor 41, a travel drive system 42, the aforementioned arm drive system 43, a communication device 44, and a controller 45.

[0024] The travel sensor 41 is a sensor that detects markers indicating the travel path. Existing markers indicating the travel path and the travel sensor 41 are used. The travel drive system 42 drives the drive wheels 13 with a motor or the like, and moves the unmanned transport vehicle 1 along the aforementioned travel path.

[0025] In Embodiment 1, the arm drive system 43 moves the arm 15-1 from the automated guided vehicle 1 in a predetermined direction (that is, extends the arm 15-1 onto the transport path of the conveyor 2), and returns the arm 15-1 (from the transport path) to the automated guided vehicle 1 in order to receive the article 101 (that is, stores the arm 15-1 in the automated guided vehicle 1).

[0026] The communication device 44 communicates with an external server (not shown) via wireless communication or other means.

[0027] The controller 45 is a computer or ASIC (Application Specific Integrated Circuit) that executes a control program, and controls the travel drive system 42 and the arm drive system 43 based on the output of the travel sensor 41 and the imaging device 16 to move the unmanned transport vehicle 1 and to pick up items 101 from the conveyor 2.

[0028] In particular, the controller 45 (a) moves the arm 15-1 from the automated guided vehicle 1 to the transport path using the arm drive system 43, and (b) increases the travel speed of the automated guided vehicle 1 to be higher than the transport speed of the article 101 (i.e., the transport speed of the conveyor 2) so that the arm 15-1 is in contact with the article 101, and while supporting the article 101 with the claw portion 21 (claw member 31) of the arm 15-1, the controller 45 moves the arm 15-1 from the transport path back to the automated guided vehicle 1 using the arm drive system 43, thereby moving the article 101 together with the arm 15-1 and storing the article 101 in the storage section (upper surface 11b).

[0029] In Embodiment 1, when the article 101 is placed in the storage section (upper surface 11b), the arms 15-1 and 15-2 are spaced apart from each other so that the article 101 does not come into contact with the claw portion 21 of the downstream arm 15-2. In Embodiment 1, the downstream arm 15-2 may not be provided with a claw portion 21.

[0030] Next, the operation of the automated guided vehicle 1 according to Embodiment 1 will be described. Figures 8 and 9 are diagrams illustrating the operation of the automated guided vehicle 1 in Embodiment 1.

[0031] The automated guided vehicle 1 is stationary and waiting at its home position (the position shown in Figure 1), and the controller 45 is monitoring the images captured by the imaging device 16. When an item 101 is transported on the conveyor belt 2, and the controller 45 detects the visible code 101a (in this case, a two-dimensional code) attached to the item 101, it decodes the visible code 101 to obtain the identification information of the item 101.

[0032] Furthermore, when the controller 45 detects the visible code 101a attached to the item 101, it controls the travel drive system 42 to start the movement of the automated guided vehicle 1. At this point, the item 101 is moving ahead of the automated guided vehicle 1. The controller 45 then accelerates the automated guided vehicle 1 until its travel speed reaches a predetermined speed that is higher than the transport speed.

[0033] Furthermore, while the automated guided vehicle 1 is in motion, the controller 45 controls the arm drive system 43, for example as shown in Figure 8, to move the upstream arm 15-1 along the rail 14-1 onto the conveyor 2. At this time, the controller 45 moves the arm 15-1 to a predetermined position where the position of the claw member 31 of the claw portion 21 exceeds the end of the article 101 (the end opposite to the automated guided vehicle 1) in the direction of movement of the arm 15-1 (i.e., a direction approximately perpendicular to the direction of travel and the direction of transport). When the claw member 31 of the claw portion 21 comes into contact with the article 101 while the arm 15-1 is moving, the claw member 31 is pushed into the arm 15-1 by the contact with the article 101, for example as shown in Figure 5. After that, when the claw member 31 of the claw portion 21 is no longer in contact with the article 101, the elastic member 32 rotates it to the limit angle of the movable angle range, for example as shown in Figure 6, and it protrudes from the arm surface 15-1a.

[0034] At this time, the controller 45 does not move the downstream arm 15-2 onto the conveyor 2.

[0035] Subsequently, if the controller 45 determines, for example, that the arm 15-1 is in contact with the item 101 based on the position of the visible code 101a in the captured image, it controls the arm drive system 43 to move the upstream arm 15-1 along the rail 14-1 to the automated guided vehicle 1, as shown in Figure 9. At this time, since the item 101 is in contact with the arm 15-1 and the claw portion 21, it moves together with the arm 15-1 to the storage section (upper surface 11b) of the automated guided vehicle 1. For example, when the item 101 comes into contact with the arm 15-1 and the item 101 moves at the same speed as the automated guided vehicle 1, and the position of the visible code 101a in the captured image no longer changes substantially, it is determined that the arm 15-1 is in contact with the item 101.

[0036] After storing the item 101 in this manner, the automated guided vehicle 1 travels along its route to the destination (in this case, a predetermined location on the storage shelf 3). The destination is identified, for example, by a database or server based on the identification information of the item 101.

[0037] When the automated guided vehicle 1 arrives at its destination, the controller 45 uses the arm drive system 43 to move arm 15-1 forward (to a predetermined position on the storage shelf 3) without using arm 15-2, pushing the item 101 into contact with the item 101 using the claw portion 22, and moving the item 101 to the predetermined position on the storage shelf 3. After placing the item 101 on the storage shelf 3, the controller 45 controls the travel drive system 42 to move the automated guided vehicle 1 to a position where the claw portion 21 does not come into contact with the item 101. After that, the controller 45 returns arm 15-1 to its original position on the automated guided vehicle 1 and controls the travel drive system 42 to move the automated guided vehicle 1 along the travel path to the home position.

[0038] As described above, according to Embodiment 1, the automated guided vehicle 1 travels along a predetermined travel path and uses the arm 15-1 to pick up and transport the article 101. The claw portion 21 is provided on the arm surface 15-1a facing the storage portion at the tip of the arm 15-1 and supports the article 101 when it is picked up. The claw portion 21 comprises a substantially plate-shaped claw member 31 that is rotatable within a predetermined angular range about a pivot axis, and an elastic member 32 that biases the claw member 31 to protrude from the arm surface 15-1a.

[0039] This eliminates the need for an electrical drive device for the claw portion 21 provided on the arm 15-1, thereby lowering the cost of the automated guided vehicle 1.

[0040] Embodiment 2.

[0041] In Embodiment 2, the automated guided vehicle 1 uses the downstream arm 15-2 to receive the article 101 without using the upstream arm 15-1.

[0042] In Embodiment 2, the controller 45: (a) uses the arm drive system 43 to move the arm 15-2 from the unmanned transport vehicle 1 onto the transport path of the article 101; (b) when the unmanned transport vehicle 1 is traveling parallel to the article 101, while reducing the traveling speed of the unmanned transport vehicle 1 to be lower than the transport speed of the article 101 and bringing the arm 15-2 into contact with the article 101, supports the article 101 with the claw portion 21 (claw member 31) of the arm 15-2, and uses the arm drive system 43 to move the arm 15-2 from the transport path onto the unmanned transport vehicle 1, thereby moving the article 101 together with the arm 15-2 and accommodating the article 101 in the accommodating portion (upper surface 11b).

[0043] In Embodiment 2, when accommodating the article 101 in the accommodating portion (upper surface 11b), the arm 15-1 and the arm 15-2 are separated from each other so that the article 101 does not contact the claw portion 21 of the upstream arm 15-1. Further, in Embodiment 2, the upstream arm 15-1 may be provided without the claw portion 21.

[0044] Next, the operation of the unmanned transport vehicle 1 according to Embodiment 2 will be described.

[0045] The unmanned transport vehicle 1 is stationary and waiting at the home position. When the article 101 is conveyed by the conveyor 2, as in Embodiment 1, when the controller 45 detects the visible code 101a attached to the article 101, it decodes the visible code 101 to obtain the identification information of the article 101.

[0046] Further, when the controller 45 detects the visible code 101a attached to the article 101, it controls the traveling drive system 42 to start the traveling of the unmanned transport vehicle 1, and accelerates the unmanned transport vehicle 1 until the traveling speed of the unmanned transport vehicle 1 reaches a predetermined speed higher than the transport speed.

[0047] Then, based on, for example, the position of the visible code 101a in the captured image, when the controller 45 determines that the arm 15-2 (position) has overtaken the article 101 in the traveling direction and the conveying direction, the controller 45 controls the arm drive system 43 to move the downstream arm 15-2 onto the conveyor 2 along the rail 14-2. At this time, the controller 45 moves the arm 15-2 to a predetermined position where the position of the claw member 31 of the claw portion 21 exceeds the end portion of the article 101 (the end portion on the side opposite to the driverless transport vehicle 1) in the moving direction of the arm 15-2 (i.e., a direction substantially perpendicular to the traveling direction and the conveying direction). When the claw member 31 of the claw portion 21 contacts the article 101 while the arm 15-2 is moving, similar to the first embodiment, the claw member 31 is pushed into the arm 15-2 by the contact of the article 101, and then, when the claw member 31 of the claw portion 21 no longer contacts the article 101, the claw member 31 rotates to the limit angle within the movable angle range by the elastic member 32 and protrudes from the arm surface 15-2a.

[0048] The controller 45 does not move the upstream arm 15-1 onto the conveyor 2.

[0049] Also, when it is determined that the arm 15-2 (position) has overtaken the article 101, the controller 45 uses the traveling drive system 42 to reduce the traveling speed of the driverless transport vehicle 1 to a predetermined speed lower than the conveying speed of the conveyor 2. Then, based on, for example, the position of the visible code 101a in the captured image, when the controller 45 determines that the arm 15-2 is in contact with the article 101, the controller 45 controls the arm drive system 43 to return the upstream arm 15-2 to the driverless transport vehicle 1 along the rail 14-2. At this time, since the article 101 is in contact with the arm 15-2 and the claw portion 21, the article 101 moves to the storage portion (upper surface 11b) of the driverless transport vehicle 1 together with the arm 15-2. For example, when the article 101 contacts the arm 15-2 and the article 101 moves at the same speed as the driverless transport vehicle 1 and the position of the visible code 101a in the captured image hardly changes, it is determined that the arm 15-2 is in contact with the article 101.

[0050] After receiving the item 101 in this manner, the automated guided vehicle 1 travels along its route to the destination (in this case, a predetermined position on the storage shelf 3). When the automated guided vehicle 1 arrives at the destination, the controller 45 uses the arm drive system 43 to move arm 15-2 forward (to the predetermined position on the storage shelf 3) without using arm 15-1, pushing the item 101 into contact with the item 101 using the claw portion 22, thereby moving the item 101 to the predetermined position on the storage shelf 3. After placing the item 101 on the storage shelf 3, the controller 45 controls the travel drive system 42 to move the automated guided vehicle 1 to a position where the claw portion 21 does not contact the item 101. After that, the controller 45 returns arm 15-2 to its original position on the automated guided vehicle 1 and controls the travel drive system 42 to move the automated guided vehicle 1 along its route to the home position.

[0051] The other configurations and operations of the unmanned transport vehicle 1 according to Embodiment 2 are the same as those of Embodiment 1, so their description will be omitted.

[0052] Embodiment 3.

[0053] In Embodiment 3, the automated guided vehicle 1 uses both arms 15-1 and 15-2 to accommodate the article 101. In Embodiment 3, the distance between arms 15-1 and 15-2 is set such that the article 101 fits between them, and the claw portion 21 (claw member 31) of arm 15-1 and the claw portion 21 (claw member 31) of arm 15-2 contact the article 101.

[0054] In Embodiment 3, the arms 15-1 and 15-2 are movable in both directions, the storage shelf 3 is located on the opposite side of the travel path from Figure 1, and the claw portion 22 is not provided. The controller 45 moves the arms 15-1 and 15-2 onto the transport path until the claw members 31 of the arms 15-1 and 15-2 extend beyond the end of the article 101 when the automated guided vehicle 1 is located at the same position as the article 101 in the travel direction and the transport direction. Then, the controller 45 moves the arms 15-1 and 15-2 towards the automated guided vehicle 1, bringing the claw members 31 of the arms 15-1 and 15-2 into contact with the article 101 and placing it in the storage section (upper surface 11b).

[0055] Furthermore, at the destination, the controller 45 moves the arms 15-1 and 15-2, bringing them into contact with the claw members 31 of the arms 15-1 and 15-2, and pushes the article 101 from the storage section (upper surface 11b) to the destination (that is, on the opposite side of the travel path from when it was stored).

[0056] In the third embodiment, the imaging device 16 is positioned so as not to come into contact with the article 101 when it is placed on the storage shelf 3.

[0057] The other configurations and operations of the unmanned transport vehicle 1 according to Embodiment 3 are the same as those of Embodiments 1 or 2, so their description will be omitted.

[0058] Furthermore, various changes and modifications to the embodiments described above will be obvious to those skilled in the art. Such changes and modifications may be made without deviating from the spirit and scope of the subject matter and without diminishing the intended advantages. In other words, such changes and modifications are intended to be included in the claims.

[0059] For example, in embodiments 1 to 3 described above, the automated guided vehicle 1 houses the items 101 being transported, but it may also be used to similarly house items that are stationary and placed on shelves or the like.

[0060] Furthermore, in embodiments 1 to 3 described above, the rotation surface of the claw member 31 is horizontal, but the claw portion 21 may be arranged so that the rotation surface of the claw member 31 is vertical. However, in that case, the limit angle of the rotational angle range described above is set to a predetermined angle less than perpendicular to the arm surface 15-ia, so that when the claw member 31 comes into contact with the article 101 during the movement of the automated guided vehicle 1, the claw member 31 is retracted into the arm 15-i by that contact.

[0061] The present invention can be applied, for example, to automated guided vehicles.

Claims

1. An automated guided vehicle (AGV) that travels along a predetermined route and transports goods, comprising: a storage section in which the goods are stored; an arm; an arm drive system that moves the arm from the AGV in a predetermined direction and returns the arm to the AGV to store the goods; and a claw portion provided on the arm surface facing the storage section at the tip of the arm to support the goods when storing them, wherein the claw portion comprises a substantially plate-shaped claw member rotatably arranged within a predetermined angular range about a pivot axis, and an elastic member that biases the claw member to protrude from the arm surface.

2. The unmanned transport vehicle according to claim 1, wherein the claw member (a) has a first surface and a second surface facing each other, (b) when the arm moves from the unmanned transport vehicle in the predetermined direction by the arm drive system, the article is housed in the arm against the elastic member when it comes into contact with the first surface, (b) when the article is not in contact with the first surface of the claw member, it is rotated to the predetermined angle by the elastic member, and (c) when the arm returns to the unmanned transport vehicle together with the article by the arm drive system, the article is supported by the second surface.

3. The automated guided vehicle according to claim 1, further comprising: a travel drive system for moving the automated guided vehicle along the travel path; and a controller for controlling the travel drive system and the arm drive system, wherein the arm is located upstream of the storage section in the travel path; and the controller (a) moves the arm from the automated guided vehicle to the article transport path using the arm drive system; and (b) moves the arm from the transport path to the automated guided vehicle using the arm drive system while supporting the article with the claw portion, with the travel speed of the automated guided vehicle being higher than the transport speed of the article and the arm in contact with the article, thereby moving the article together with the arm and storing the article in the storage section.

4. The automated guided vehicle according to claim 1, further comprising: a travel drive system for moving the automated guided vehicle along the travel path; and a controller for controlling the travel drive system and the arm drive system, wherein the arm is located downstream of the storage section in the travel path; and the controller (a) moves the arm from the automated guided vehicle to the transport path of the article using the arm drive system; and (b) while the automated guided vehicle is traveling parallel to the article, the travel speed of the automated guided vehicle is lower than the transport speed of the article, and the arm is in contact with the article, supporting the article with the claw portion, and moving the arm from the transport path to the automated guided vehicle using the arm drive system, thereby moving the article together with the arm and storing the article in the storage section.

Images