Automatic guided vehicle, conveyance system and conveyance method

Abstract

To provide an automatic guided vehicle, a conveyance system, and a conveyance method which are capable of suppressing deviation of a position of a conveyed article conveyed to a destination.SOLUTION: A conveyance system 1 includes: a conveyed article 3 having wheels on a bottom surface part and a space S formed between the bottom surface part and a floor surface FL; an automatic guided vehicle 5; and a guide device 7 installed in the vicinity of a destination. The automatic guided vehicle 5 has: a conveyance vehicle body 19; a lift table 21 that can be raised and lowered relative to the conveyance vehicle body 19; and a lift control part (control part 33) that switches the lift table between a lower limit state, an upper limit state, and an intermediate state. The intermediate state is a height at which the wheels 15 contact the floor surface FL when inserted into the space S of the conveyed article 3, and a height at which the side surface 21A of the lifting table 21 can contact a contacted part 17 provided on the conveyed article 3. When the automatic guided vehicle 5 pushes and moves the contacted part 17 in the intermediate state, the guide device 7 comes into contact with the conveyed article 3 and guides the conveyed article 3 to a destination DE.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an automated guided vehicle, a conveyance system, and a conveyance method.

Background Art

[0002] There is a technology related to an automated guided vehicle (AGV: Automatic Guided Vehicle) that conveys an object to be conveyed, such as a shelf or a cart, to a destination (Patent Document 1 and Patent Document 2). The automated guided vehicle has a lifting table that can be lifted with respect to the vehicle body.

[0003] After moving to below the object to be conveyed, the automated guided vehicle raises the lifting table to lift the object to be conveyed and conveys the object to be conveyed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Since the automated guided vehicle does not have a means for regulating the travel route, due to deviations caused by the automated guided vehicle such as the limit of the accuracy of the self-position estimated by the automated guided vehicle, or deviations caused by the surrounding environment such as floor inclination and steps, it is inevitable to allow a deviation of about ±10 to 20 [mm] with respect to the planned travel route. Therefore, the position of the object to be conveyed that has been conveyed to the destination also has a deviation of the same degree.

[0006] However, depending on the object to be transported, a high level of accuracy in the position at the destination (for example, about ±5 [mm]) may be required. For example, when pushing and delivering the luggage inside the object to be transported into the luggage receiving device installed at the destination, if there is a gap due to misalignment between the receiving device and the object to be transported, the luggage may fall into the gap and it may not be possible to deliver the luggage.

[0007] It was difficult to ensure the accuracy of the traveling accuracy of the automated guided vehicle. Therefore, conventionally, transportation was performed using a conveyor without using an automated guided vehicle, and the position of the object to be transported on the conveyor was regulated by a guide or a stopper.

[0008] An object of the present invention is to provide an automated guided vehicle, a transportation system, and a transportation method capable of suppressing displacement of the position of an object to be transported to a destination.

Means for Solving the Problems

[0009] In order to achieve the above object, the automated guided vehicle of the present invention includes a vehicle body, a lifting table provided on the vehicle body and capable of lifting with respect to the vehicle body, a lower limit state in which the height of the lifting table with respect to the vehicle body is the lower limit, and an upper limit state in which the height of the lifting table with respect to the vehicle body is the upper limit. An automated guided vehicle provided with a lifting control unit that controls the lifting of the lifting table by switching between them, wherein the lifting control unit can switch the height of the lifting table with respect to the vehicle body to an intermediate state that is a height between the upper limit and the lower limit.

[0010] Further, the conveying system of the present invention includes an object to be conveyed having wheels on the bottom surface and a space formed between the object and the floor surface, an automated guided vehicle that enters the space of the object to be conveyed and conveys the object to be conveyed, and a guiding device installed around the destination of the object to be conveyed to guide the object to be conveyed to the destination. The automated guided vehicle includes a vehicle body, a lifting table provided on the vehicle body and capable of lifting with respect to the vehicle body, a lower limit state in which the height of the lifting table with respect to the vehicle body is at a lower limit, an upper limit state in which the height of the lifting table with respect to the vehicle body is at an upper limit, and a height of the lifting table with respect to the vehicle body is between the upper limit and the lower limit. The lifting control unit that controls the lifting of the lifting table by switching between the intermediate states, and the intermediate state is a height at which the wheels are in contact with the floor surface when the lifting table enters the space of the object to be conveyed, and the side surface of the lifting table can contact an abutting portion provided on the object to be conveyed. The guiding device contacts the object to be conveyed when the automated guided vehicle pushes and moves the abutting portion in the intermediate state, and guides the object to be conveyed to the destination.

[0011] The conveying method of the present invention also includes a conveyed object having wheels on the bottom surface and a space formed between the floor surface, an automated guided vehicle that enters the space of the conveyed object to convey the conveyed object, and a guiding device installed around the destination of the conveyed object to guide the conveyed object to the destination. The automated guided vehicle includes a vehicle body, a lifting table provided on the vehicle body and capable of lifting with respect to the vehicle body, a lower limit state in which the height of the lifting table with respect to the vehicle body is the lower limit, an upper limit state in which the height of the lifting table with respect to the vehicle body is the upper limit, and a middle state in which the height of the lifting table with respect to the vehicle body is between the upper limit and the lower limit. The automated guided vehicle has a lifting control unit that controls the lifting of the lifting table by switching between these states. The middle state is a height at which the wheels contact the floor surface when the automated guided vehicle enters the space of the conveyed object, and is a height at which the side surface of the lifting table can contact a contacted portion provided on the conveyed object. The method includes steps of: conveying the conveyed object to around the destination by the automated guided vehicle; switching the height of the lifting table to the middle state; pushing the contacted portion provided on the conveyed object by the automated guided vehicle with the lifting table in the middle state to move the conveyed object to the destination; and guiding the conveyed object to the destination by the guiding device when the automated guided vehicle pushes the contacted portion in the middle state to move the conveyed object.

Effect of the Invention

[0012] According to the automated guided vehicle, the conveying system, and the conveying method of the present invention, it is possible to suppress displacement of the position of the conveyed object conveyed to the destination.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3A

Figure 3B

Figure 4A

Figure 4B

Figure 5

Figure 6A

Figure 6B

Figure 6C

Figure 6D

Figure 6E

Figure 6F

Figure 6G

Figure 6H

Figure 6I

Embodiments for Carrying Out the Invention

[0014] Hereinafter, embodiments of the automated guided vehicle, conveying system, and conveying method according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic plan view showing an example of a conveying system including an automated guided vehicle, FIG. 2 is a block diagram of the conveying system including the automated guided vehicle, FIG. 3A is a perspective view of an object to be conveyed, FIG. 3B is an enlarged view of the object to be conveyed in area B shown in FIG. 3A, FIG. 4A is a perspective view of the automated guided vehicle, and FIG. 4B is a bottom view of the automated guided vehicle.

[0015] In the present embodiment, as shown in FIG. 1, for the conveying system 1, a front-rear direction L and a width direction W are defined. Further, as shown in FIGS. 3 and 4, for the object to be conveyed 3 and the automated guided vehicle 5, a front-rear direction X, a left-right direction Y, and an up-down direction Z are defined.

[0016] <Conveying system> As shown in FIGS. 1 and 2, the conveying system 1 includes an object to be conveyed 3, an automated guided vehicle 5, a guiding device 7, and a management computer 9. The conveying system 1 transports the object to be conveyed 3 to a destination DE by the automated guided vehicle 5, and delivers the load LD held by the object to be conveyed 3 to a load receiving device LRD installed adjacent to the destination DE.

[0017] [Object to be conveyed] In the present embodiment, as shown in FIGS. 3A and 3B, the object to be conveyed 3 is a cart capable of loading the load LD, and has a load loading section 11, legs 13, and wheels 15. The load loading section 11 is composed of a frame assembled in a rectangular parallelepiped shape, has a plurality of partitions inside, and is in a shelf shape capable of loading the load LD (in FIG. 3A, an example of the loaded load LD is illustrated by a virtual line). The legs 13 are four legs 13A to 13D extending downward from the corners of the bottom surface portion 11A of the load loading section 11. The wheels 15 are attached one by one to the ends of the four legs 13A to 13D and are the portions in contact with the floor surface FL. In FIG. 3B, the legs 13B and 13D, and the wheels 15B and 15D hidden on the opposite side are shown in parentheses.

[0018] On the legs 13A and 13B located in front of the object 3 to be conveyed in the X direction, there are attached swivel casters 15A and 15B that can swivel around a swivel axis extending in the Z direction and can move in the XY plane direction. Further, on the legs 13C and 13D located behind the object 3 to be conveyed in the X direction, there are attached non-swivel casters 15C and 15D that cannot swivel and can only move in the X direction.

[0019] In addition, when the caster located behind in the X direction is a swivel caster, when the object 3 to be conveyed is advanced in the forward X direction, the rear of the object 3 to be conveyed will meander, and the force required to advance the object 3 forward will increase. Therefore, it is desirable that the caster located in the forward X direction is a swivel caster and the caster located in the rear X direction is a non-swivel caster.

[0020] The object 3 to be conveyed has a space S formed between it and the floor surface FL by the bottom surface portion 11A, the legs 13 (legs 13A to 13D), and the wheels 15 (swivel casters 15A and 15B, non-swivel casters 15C and 15D). On the bottom surface portion 11A of the object 3 to be conveyed, there is provided a contact portion 17 that comes into contact with a lifting table described later at a position in front in the X direction within the space S (that is, a position closer to the legs 13A and 13B). The contact portion 17 is a rod-shaped member extending in the Y direction.

[0021] [Automated Guided Vehicle] The automated guided vehicle 5, also called an AGV (Automatic Guided Vehicle), is a rectangular parallelepiped-shaped transport vehicle controlled by a management computer 9 as shown in FIGS. 4A and 4B. The automated guided vehicle 5 has a transport vehicle body 19, a lifting table 21, a left wheel 23, a right wheel 25, and an auxiliary wheel 27.

[0022] As shown in FIG. 2, the transport vehicle body 19 has a communication unit 29, a battery 31, a control unit 33, a left wheel drive unit 35, a right wheel drive unit 37, a lifting table drive unit 39, and a two-dimensional code scanner 41.

[0023] The communication unit 29 communicates with the management computer 9 when receiving an instruction from the management computer 9 or reporting the state of the automated guided vehicle 5. The communication method of the communication unit 29 may be wireless communication or wired communication. However, in this embodiment, wireless communication is used to avoid interfering with the movement of the automated guided vehicle 5.

[0024] The battery 31 is a power supply for driving the automated guided vehicle 5. In this embodiment, the battery 31 is a rechargeable secondary battery, which may be a secondary battery such as a lead-acid battery, a lithium-ion battery, or a nickel-metal hydride battery, or a high-capacity capacitor such as a lithium-ion capacitor.

[0025] The control unit 33 receives an instruction from the management computer 9 and controls the operation of the automated guided vehicle 5, including the left wheel drive unit 35, the right wheel drive unit 37, and the lift table drive unit 39.

[0026] The left wheel drive unit 35 is controlled by the control unit 33 to rotate the left wheel 23 (see FIG. 4B) in one direction and the opposite direction. The right wheel drive unit 37 is controlled by the control unit 33 to rotate the right wheel 25 (see FIG. 4B) in one direction and the opposite direction. When the left wheel drive unit 35 and the right wheel drive unit 37 rotate in the same direction, the automated guided vehicle 5 moves forward or backward. When the left wheel drive unit 35 and the right wheel drive unit 37 rotate in different directions, the automated guided vehicle 5 turns on the spot.

[0027] The lift table drive unit 39 is controlled by the control unit 33 to raise and lower the lift table 21. By the lift table drive unit 39, the lift table 21 can be switched between a lower limit state where the height of the lift table 21 with respect to the carrier body 19 is the lower limit and an upper limit state where the height of the lift table 21 with respect to the carrier body 19 is the upper limit. Further, in this embodiment, by the lift table drive unit 39, the lift table 21 can be switched to an intermediate state where the height of the lift table 21 with respect to the carrier body 19 is between the upper limit and the lower limit.

[0028] Here, the "lower limit state" is a state where the lifting table 21 has descended to the lower limit. That is, the AGV 5 can enter the space S provided in the object 3 to be transported, and the lifting table 21 does not contact the bottom surface portion 11A of the object 3 to be transported. Further, the "upper limit state" is a state where the lifting table 21 has ascended to the upper limit. That is, in a state where the AGV 5 has entered the space S provided in the object 3 to be transported, when the lifting table 21 reaches the upper limit state, the object 3 to be transported is lifted, the wheels 15 (swivel casters 15A, 15B, non-swivel casters 15C, 15D) are separated from the floor surface FL, and the object 3 to be transported can be transported by the AGV 5. Furthermore, the "intermediate state" is a state where the lifting table 21 is at a height between the upper limit and the lower limit. That is, in a state where the AGV 5 has entered the space S provided in the object 3 to be transported, when the lifting table 21 reaches the intermediate state, the wheels 15 (swivel casters 15A, 15B, non-swivel casters 15C, 15D) are at a height where they are in contact with the floor surface FL, and the side surface 21A of the lifting table 21 can contact the contact portion 17.

[0029] Note that hereinafter, controlling the lifting table 21 to the lower limit state may be expressed as "switching to the lower limit mode", controlling it to the upper limit state may be expressed as "switching to the upper limit mode", and controlling it to the intermediate state may be expressed as "switching to the intermediate mode".

[0030] The two-dimensional code scanner 41 is a reading device provided on the bottom surface portion 19A of the carrier body 19. The two-dimensional code scanner 41 reads the two-dimensional codes CD arranged on the floor surface FL at various locations, acquires the current position of the AGV 5, and transmits information regarding the current position to the control unit 33. In FIG. 1, the two-dimensional codes CD1 to CD4 are arranged along the travel route DR.

[0031] [Induction device] The induction device 7 is installed around the destination DE, contacts the object 3 to be transported, and guides the object 3 to be transported to the destination DE. In the present embodiment, as shown in FIGS. 1 and 2, the induction device 7 has a first guide portion 43 and a second guide portion 45.

[0032] The first guide portion 43 extends along the front - rear direction L along which the travel route DR of the automated guided vehicle 5 extends, and includes a pair of guide walls 47, 47' that are installed facing each other in the width direction W intersecting the front - rear direction L with the travel route DR therebetween. In the present embodiment, the guide wall 47 on the right side in the traveling direction of the travel route DR is a movable guide wall that is movable in the width direction W. As shown in FIG. 2, the guide wall (movable guide wall) 47 has a communication unit 49 and a movable guide wall driving unit 51, and is movable in the width direction W according to an instruction from the management computer 9. The pair of guide walls 47, 47' come into contact with the object 3 to be transported that is moved by the automated guided vehicle 5, and correct the deviation of the object 3 in the width direction W.

[0033] Note that a plurality of rollers 48 having a rotation axis extending in a direction orthogonal to the front - rear direction L are provided along the travel route DR on the wall portion including the pair of guide walls 47, 47', so that the friction due to contact is reduced.

[0034] The second guide portion 45 includes a pair of stopper portions (front stopper and rear stopper) 53, 53' that are installed facing each other in the front - rear direction L with the destination DE therebetween along the travel route DR. As shown in FIGS. 1 and 2, the pair of stopper portions 53, 53' have a communication unit 55, a front stopper driving unit 57, and a rear stopper driving unit 59, and operate according to an instruction from the management computer 9 to move in the width direction W. Further, the pair of stopper portions (front stopper and rear stopper) 53, 53' have a pair of pushers 54, 54' that move in the front - rear direction L at their tip portions. The pair of stopper portions 53, 53' are in a standby state at a position that does not hinder the movement of the object 3 to be transported that is moved by the automated guided vehicle 5 before receiving an instruction from the management computer 9. The pair of stopper portions 53, 53' receive an instruction from the management computer 9, position themselves so as to sandwich the front and rear of the object 3 that has been moved to the destination DE by the automated guided vehicle 5, and then the pair of pushers 54, 54' perform an operation of pushing the object 3 in the front - rear direction L (see FIG. 6F). Thereby, the deviation of the object 3 in the front - rear direction L at the destination DE is corrected.

[0035] [Management computer] The management computer 9 is a computer that manages and controls the automated guided vehicle 5, the guide wall 47, and the pair of stopper portions 53, 53'. It has a control unit 61, a communication unit 63, a display unit 65, and an input unit 67. The control unit 61 includes an automated guided vehicle control unit 61A, a movable guide wall control unit 61B, and a stopper control unit 61C. The administrator of the transport system 1 uses the input unit 67 to instruct the automated guided vehicle 5 to transport the object to be transported 3, and the automated guided vehicle control unit 61A instructs the automated guided vehicle 5 via the communication unit 63. When the automated guided vehicle 5 reaches the vicinity of the destination DE, the management computer 9 controls the automated guided vehicle 5, the guide wall 47, and the pair of stopper portions 53, 53' as described below to move the automated guided vehicle 5 and the object to be transported 3 to the destination DE. Although not shown, in this embodiment, the management computer 9 can also control a load pushing device LPD that pushes the load LD in the load loading portion 11 against the load receiving device LRD.

[0036] [Guidance to the destination] Referring to the sequence diagram of FIG. 5 and FIGS. 6A to 6I, a transport method for transporting the object to be transported 3 to the destination DE while suppressing the displacement of the position of the object to be transported 3 using the transport system 1 will be described. FIGS. 6A to 6I are a plan view of the transport system and side views of the object to be transported 3 and the automated guided vehicle 5 at that time. For convenience of explanation, in FIGS. 6A to 6I, some members are shown in a perspective view. Also, in FIGS. 6A to 6I, the load pushing device LPD and the load receiving device LRD are not shown.

[0037] First, the management computer 9 instructs the automated guided vehicle 5 to transport the object 3 to the position of the two-dimensional code CD1 (around the destination DE) (step ST1). Upon receiving the instruction, the automated guided vehicle 5 enters the space S of the object 3 in the lower limit mode, switches to the upper limit mode, lifts the object 3, and moves to the position of the instructed two-dimensional code CD1. When the automated guided vehicle 5 reads the two-dimensional code CD1, it reports its status to the management computer 9 (step ST2 · Fig. 6A). When the automated guided vehicle 5 moves to the position of the two-dimensional code CD1, as shown in Fig. 6A, the front part of the automated guided vehicle 5 and the object 3 comes to a position sandwiched between a pair of guide walls 47, 47'.

[0038] When the management computer 9 confirms that the automated guided vehicle 5 has moved to the position of the two-dimensional code CD1, it instructs the automated guided vehicle 5 to switch the lifting table 21 to the intermediate mode (step ST3). When the switching to the intermediate mode is completed, the automated guided vehicle 5 reports its status to the management computer 9 (step ST4 · Fig. 6B). The mode switching at this time may be directly switched from the upper limit mode to the intermediate mode, or may be performed step by step by switching from the upper limit mode to the lower limit mode and then to the intermediate mode.

[0039] When the management computer 9 confirms that the lifting table 21 has entered the intermediate mode, it instructs the guide wall 47 to move towards the guide wall 47' (i.e., to push the object 3) (step ST5). When the guide wall 47 starts moving, it reports its status to the management computer 9 (step ST6 · Fig. 6C).

[0040] When the management computer 9 confirms the movement of the guide wall 47, it instructs the automated guided vehicle 5 to move to the position of the two-dimensional code CD2 (step ST7). When the automated guided vehicle 5 moves forward, the side surface 21A of the lifting table 21 comes into contact with the contact portion 17 of the object to be conveyed 3, and due to the forward force of the automated guided vehicle 5, the wheels 15 (swivel casters 15A, 15B, non-swivel casters 15C, 15D) roll, and the object to be conveyed 3 also moves forward. At this time, the side surface of the object to be conveyed 3 is pushed by the guide wall 47, so that the object to be conveyed 3 moves forward while being pressed against the guide wall 47', and while the deviation in the width direction W of the object to be conveyed 3 is corrected, it reaches the position of the two-dimensional code CD2. When the automated guided vehicle 5 reads the two-dimensional code CD2, it reports its status to the management computer 9 (step ST8 · Fig. 6D).

[0041] In addition, at the start of the movement, the management computer 9 can also instruct the automated guided vehicle 5 to move after turning several times (for example, 3° to 4°) so that the front part slightly faces the guide wall 47'. In this way, the deviation in the width direction W can be corrected more smoothly.

[0042] When the management computer 9 can confirm that the automated guided vehicle 5 has moved to the position of the two-dimensional code CD2, it instructs the automated guided vehicle 5 to move to the position of the two-dimensional code CD3 (destination DE) (step ST9). The automated guided vehicle 5 moves forward to the position of the two-dimensional code CD3 while pushing the object to be conveyed 3, and when it reads the two-dimensional code CD3, it reports its status to the management computer 9 (step ST10 · Fig. 6E).

[0043] When the management computer 9 can confirm that the automated guided vehicle 5 has moved to the position of the two-dimensional code CD3, it instructs the guide wall 47 to return to its original position (step ST11), and further instructs the pair of stopper parts 53, 53' to operate (step ST12). When the guide wall 47 returns to its original position, it reports its state to the management computer 9 (step ST13). The pair of stopper parts 53, 53' that have received the instruction move to sandwich the front and rear of the object to be conveyed 3, and then, the pair of pushers 54, 54' of the pair of stopper parts 53, 53' push the object to be conveyed 3 in the front-rear direction. Since the object to be conveyed 3 has wheels 15 (swivel casters 15A, 15B, non-swivel casters 15C, 15D), the deviation in the front-rear direction L is corrected by the force of the pair of pushers 54, 54'. Thereby, the object to be conveyed 3 can reach the destination DE in a state where the deviations in the width direction W and the front-rear direction L are corrected (step ST14 · FIG. 6F). In this state, when the management computer 9 can confirm the completion of the movement of the stopper parts 53, 53', it requests the luggage extrusion device LPD that extrudes the luggage LD in the luggage loading part 11 to start the operation of delivering the luggage LD to the luggage receiving device LRD (step ST15). The instructed luggage extrusion device LPD extrudes the luggage LD in the luggage loading part 11, delivers it to the luggage receiving device LRD, and when the delivery is completed, reports its state to the management computer 9 (step ST16).

[0044] When the delivery of the luggage LD is completed, the management computer 9 instructs the pair of stopper parts 53, 53' to return to their original positions (step ST17). When they return to their original positions, the pair of stopper parts 53, 53' report their state to the management computer 9 (step ST18 · FIG. 6G).

[0045] When the pair of stopper parts 53, 53' return to their original positions, the management computer 9 instructs the automated guided vehicle 5 to move to the position of the two-dimensional code CD4 (step ST19). When the automated guided vehicle 5 reads the two-dimensional code CD4, it reports its state to the management computer 9 (step ST20 · FIG. 6H).

[0046] When it is confirmed that the driverless transport vehicle 5 has moved to the position of the two-dimensional code CD4, the management computer 9 instructs the driverless transport vehicle 5 to switch the lifting table 21 to the upper limit mode (step ST21). When the switching to the upper limit mode is completed, the driverless transport vehicle 5 reports its status to the management computer 9 (step ST22 · Fig. 6I).

[0047] When it is confirmed that the lifting table 21 has entered the upper limit mode, the management computer 9 instructs the driverless transport vehicle 5 to move to the next destination (step ST23). When the driverless transport vehicle 5 reads the two-dimensional code of the next destination, it reports its status to the management computer 9 and the operation is completed (step ST24).

[0048] <Function> The functions of the driverless transport vehicle, the transport system, and the transport method will be described below.

[0049] The driverless transport vehicle 5 includes a transport vehicle main body 19, a lifting table 21 provided on the transport vehicle main body 19 and capable of lifting with respect to the transport vehicle main body 19, a lower limit state in which the height of the lifting table 21 with respect to the transport vehicle main body 19 is the lower limit, and an upper limit state in which the height of the lifting table 21 with respect to the transport vehicle main body 19 is the upper limit, and a lifting control unit (control unit 33) that controls the lifting of the lifting table 21 by switching between them. Moreover, the lifting control unit (control unit 33) of the driverless transport vehicle 5 can switch the height of the lifting table 21 with respect to the transport vehicle main body 19 to an intermediate state where the height is between the upper limit and the lower limit.

[0050] Therefore, the driverless transport vehicle 5 of the present embodiment can not only lift and transport the object to be transported 3 by the driverless transport vehicle 5, but also push and move the object to be transported 3, and can finely adjust the position of the object to be transported at the destination. Therefore, with the driverless transport vehicle of the present invention, it is possible to suppress the deviation of the position of the object to be transported that has been transported to the destination.

[0051] The intermediate state is the height at which the wheels 15 touch the floor surface FL when the wheels 15 of the object to be conveyed 3 having the wheels 15 on the bottom surface portion 11A enter the space S of the object to be conveyed 3 in which the space S is formed between the floor surface FL, and is the height at which the side surface 21A of the lifting table 21 can contact the contact portion 17 provided on the object to be conveyed 3. In this way, the automated guided vehicle 5 can enter the space S and push the contact portion 17 with the side surface 21A of the lifting table 21 to move the object to be conveyed 3.

[0052] The conveying system 1 includes the above-described object to be conveyed 3, the above-described automated guided vehicle 5, and a guiding device 7 installed around the destination DE of the object to be conveyed 3 for guiding the object to be conveyed 3 to the destination DE. Then, when the automated guided vehicle 5 pushes and moves the contact portion 17 in the intermediate state, the guiding device 7 contacts the object to be conveyed 3 and guides the object to be conveyed 3 to the destination DE. Therefore, it is possible to suppress the displacement of the position of the object to be conveyed guided by the guiding device 7 and conveyed to the destination.

[0053] As described above, the guiding device 7 contacts the object to be conveyed 3 when the automated guided vehicle 5 pushes and moves the contact portion 17 in the intermediate state, and does not contact the object to be conveyed 3 being conveyed by the automated guided vehicle 5 in the upper limit state. In the upper limit state, the wheels 15 of the object to be conveyed 3 are separated from the floor surface FL. If the guiding device 7 contacts the object to be conveyed 3 being conveyed by the automated guided vehicle 5 in the upper limit state, a load is applied to the automated guided vehicle 5 via the object to be conveyed 3, which may prevent the automated guided vehicle 5 from traveling or damage the automated guided vehicle 5 or the object to be conveyed 3. On the other hand, in the intermediate state, the wheels 15 of the object to be conveyed 3 are in contact with the floor surface FL, and the automated guided vehicle 5 pushes the contact portion 17 to move the object to be conveyed 3. Even if the guiding device 7 contacts the object to be conveyed 3, no load is applied to the automated guided vehicle 5, and it is possible to correct the deviation of the orientation and position of the object to be conveyed 3.

[0054] The guiding device 7 extends along the longitudinal direction L in which the traveling path DR of the automated guided vehicle 5 extends, and includes a pair of guide walls 47, 47' that are installed opposite to each other in the width direction W intersecting the longitudinal direction L with the traveling path DR therebetween. The pair of guide walls 47, 47' may contact the object 3 to be conveyed that is moved by the automated guided vehicle 5 to correct the deviation of the object 3 in the width direction W. Further, at least one of the pair of guide walls may be a movable guide wall movable in the width direction W. According to such a pair of guide walls 47, 47', in cooperation with the automated guided vehicle 5, the deviation of the object 3 in the width direction W can be easily corrected.

[0055] Further, the guiding device 7 includes a pair of stopper portions 53, 53' that are installed opposite to each other in the longitudinal direction L with the destination DE therebetween along the traveling path DR. The pair of stopper portions 53, 53' may push the object 3 moved to the destination DE by the automated guided vehicle 5 in the longitudinal direction L to correct the deviation in the longitudinal direction L. According to such a pair of stopper portions 53, 53', by using the wheels 15 of the object 3, the deviation of the object 3 in the longitudinal direction L can be easily corrected.

[0056] The conveying method of the present embodiment is performed by the above-described conveying system 1, and includes a step of conveying the object 3 to the vicinity of the destination DE by the automated guided vehicle 5, a step of switching the height of the lifting table 21 to an intermediate state, a step of pushing the contacted portion 17 provided on the object 3 by the automated guided vehicle 5 with the lifting table 21 in the intermediate state to move the object 3 to the destination DE, and a step of guiding the object 3 to the destination DE by the guiding device 7 when the automated guided vehicle 5 pushes the contacted portion 17 in the intermediate state to move the object 3. According to this conveying method, the deviation of the position of the object conveyed to the destination by being guided by the guiding device 7 can be suppressed.

[0057] As described above, the guiding device 7 can include a pair of guide walls 47, 47' and a pair of stopper portions 53, 53'. In this case, the step of guiding the object to be conveyed 3 to the destination DE can include the step of correcting the deviation in the width direction W of the object to be conveyed 3 by the pair of guide walls 47, 47', and the step of pushing the object to be conveyed 3 moved to the destination DE by the driverless transport vehicle 5 in the front-rear direction L by the pair of stopper portions 53, 53' to correct the deviation in the front-rear direction L. In this way, the deviation in the position of the object to be conveyed 3 conveyed to the destination DE can be suppressed by a simple method.

[0058] As described above, the embodiments of the present invention have been specifically described. However, the present invention is not limited to these embodiments, and it goes without saying that modifications are possible within the scope of the technical idea of the present invention.

[0059] For example, in this embodiment, a type of driverless transport vehicle that grasps its current position using a two-dimensional code is used. However, of course, other types of driverless transport vehicles can be used, such as a type that pastes a magnetic tape on the travel route and follows the travel route by reading the magnetic tape, or a type that estimates its own position with a laser reflector and travels.

Explanation of Reference Numerals

[0060] 1 Conveying system 3 Object to be conveyed 5 Driverless transport vehicle 7 Guiding device 9 Management computer 11 Cargo loading section 11A Bottom surface portion 13 Leg portion 15 Wheel 17 Contact portion 19 Transport vehicle body 21 Lifting table 23 Left wheel 25 Right wheel 27 Auxiliary wheel 29 Communication section 31 Battery 33 Control section 35 Left wheel drive section 37 Right wheel drive unit 39 Lifting table drive unit 41 Two-dimensional code scanner 43 First guide part 45 Second guide part 47, 47´ Pair of guide walls 49 Communication part 51 Movable guide wall drive unit 53, 53´ Pair of stopper parts 55 Communication part 57 Front stopper drive unit 59 Rear stopper drive unit 61 Control part 63 Communication part 65 Display part 67 Input part

Claims

1. A transport vehicle body, a lifting table provided on the transport vehicle body and capable of lifting with respect to the transport vehicle body, a lifting control unit that switches between a lower limit state where the height of the lifting table with respect to the transport vehicle body is at a lower limit and an upper limit state where the height of the lifting table with respect to the transport vehicle body is at an upper limit, and controls the lifting of the lifting table, and is an automated guided vehicle comprising: the lifting control unit can switch the height of the lifting table with respect to the transport vehicle body to an intermediate state where the height is between the upper limit and the lower limit An automated guided vehicle characterized by this.

2. The intermediate state is a height at which the wheels contact the floor surface when the intermediate state enters the space of the object to be transported that has wheels on the bottom surface and a space is formed between the floor surface, and is a height at which the side surface of the lifting table can contact the contact portion provided on the object to be transported. The automated guided vehicle according to claim 1, characterized by this.

3. An object to be transported having wheels on the bottom surface and a space formed between the floor surface, an automated guided vehicle that enters the space of the object to be transported and transports the object to be transported, a transport system comprising a guiding device installed around the destination of the object to be transported and guiding the object to be transported to the destination, wherein the automated guided vehicle has a transport vehicle body, a lifting table provided on the transport vehicle body and capable of lifting with respect to the transport vehicle body, a lower limit state where the height of the lifting table with respect to the transport vehicle body is at a lower limit, an upper limit state where the height of the lifting table with respect to the transport vehicle body is at an upper limit, and an intermediate state where the height of the lifting table with respect to the transport vehicle body is between the upper limit and the lower limit, and has a lifting control unit that switches between them and controls the lifting of the lifting table, the intermediate state is a height at which the wheels contact the floor surface when entering the space of the object to be transported, and is a height at which the side surface of the lifting table can contact the contact portion provided on the object to be transported, the guiding device contacts the object to be transported and guides the object to be transported to the destination when the automated guided vehicle pushes and moves the contact portion in the intermediate state A transport system characterized by this.

4. The guiding device includes a pair of guide walls that extend along the front-rear direction in which the traveling path of the automated guided vehicle extends, and face each other in the width direction that intersects the front-rear direction with the traveling path therebetween. The pair of guide walls contact the object to be conveyed that is moved by the driverless transport vehicle, and correct the deviation of the object to be conveyed in the width direction. The transport system according to claim 3, characterized in that.

5. At least one of the pair of guide walls is a movable guide wall movable in the width direction. The transport system according to claim 4, characterized in that.

6. The guiding device includes a pair of stopper portions installed to face each other in the front-rear direction in which the travel route extends with the destination interposed therebetween along the travel route of the driverless transport vehicle. The pair of stopper portions push the object to be conveyed that has been moved to the destination by the driverless transport vehicle in the front-rear direction to correct the deviation in the front-rear direction. The transport system according to claim 3, characterized in that.

7. An object to be conveyed having wheels on the bottom surface and a space formed between the object and the floor surface, A driverless transport vehicle that enters the space of the object to be conveyed and conveys the object to be conveyed, A transport method performed by a transport system including a guiding device installed around the destination of the object to be conveyed and guiding the object to be conveyed to the destination. The driverless transport vehicle includes: The driverless transport vehicle includes: A transport vehicle main body, A lifting table provided on the transport vehicle main body and capable of lifting with respect to the transport vehicle main body, A lifting control unit that controls the lifting of the lifting table by switching between a lower limit state in which the height of the lifting table with respect to the transport vehicle main body is at a lower limit, an upper limit state in which the height of the lifting table with respect to the transport vehicle main body is at an upper limit, and an intermediate state in which the height of the lifting table with respect to the transport vehicle main body is between the upper limit and the lower limit. The intermediate state is a height at which the wheels contact the floor surface when the lifting table enters the space of the object to be conveyed, and is a height at which the side surface of the lifting table can contact a contact portion provided on the object to be conveyed. Conveying the object to be conveyed to the vicinity of the destination by the driverless transport vehicle; Switching the height of the lifting table to the intermediate state; Pushing a contact portion provided on the object to be conveyed by the driverless transport vehicle with the lifting table in the intermediate state to move the object to be conveyed to the destination; When the driverless transport vehicle pushes the contact portion in the intermediate state to move the object to be conveyed, guiding the object to be conveyed to the destination by the guiding device; A transport method characterized by including.

8. The guiding device includes A pair of guide walls that extend along the front-rear direction in which the travel route of the automated guided vehicle extends, and are installed to face each other in the width direction that intersects the front-rear direction with the travel route therebetween; including a pair of stopper portions installed to face each other in the front-rear direction with the destination therebetween along the travel route; The step of guiding the object to be conveyed to the destination includes: correcting the deviation of the object to be conveyed in the width direction by the pair of guide walls; pushing the object to be conveyed moved to the destination by the automated guided vehicle in the front-rear direction by the pair of stopper portions to correct the deviation in the front-rear direction; The conveying method according to claim 7, characterized by including the above.

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