Automated guided vehicle and method for controlling the automated guided vehicle

Abstract

To provide an unmanned transport vehicle capable of properly slipping under a basket cart. [Solution] The AMR 1 slides under a basket cart and lifts or pulls the basket cart for transport. It is equipped with a camera 31 that captures the surroundings of the AMR 1, a marker reader 36 that detects an AR marker attached to the basket cart from the camera 31 image captured by the camera 31 and reads the detected AR marker, and a movement controller 37 that controls the movement of the AMR 1, and the movement controller 37 is configured to set a first target in front of the basket cart based on the position of the AR marker, control the AMR 1 to move to the position of the first target, read the AR marker again when the AMR 1 arrives at the position of the first target, set a second target under the basket cart based on the position of the AR marker, and control the AMR 1 to move to the position of the second target.

Description

[Technical field]

[0001] The present invention relates to an automated guided vehicle that moves underneath an object to lift or tow the object and transport it, and a method for controlling the same. [Background technology]

[0002] Conventionally, unmanned guided vehicles that transport objects such as basket carts have been known. Patent Document 1 discloses a guided vehicle that transports a roll box by slipping between the cage of the roll box and the running surface. Patent Document 2 discloses an unmanned guided vehicle that is configured to slip under the cart and lift a lifter bar to tow the cart. Patent Document 3 discloses an unmanned vehicle that slips under a wagon cart, lifts it up, and transports the wagon cart to a destination specified from outside. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2018-34932 [Patent Document 2] Patent Publication No. 2017-47996 [Patent Document 3] JP 9-185413 Summary of the Invention [Problem to be solved by the invention]

[0004] As described above, there are documents that disclose automated guided vehicles that can get under an object to transport it, but they do not disclose any specific control method for getting the automated guided vehicle under the object.

[0005] If the route along which the automated guided vehicle will travel and the location where the transported object will be placed are predetermined, the automated guided vehicle can be made to slip under the transported object simply by traveling along the planned route.

[0006] However, pre-determining the route that an automated guided vehicle will travel is inflexible. Also, in actual work sites such as warehouses, it cannot be expected that the transported objects, such as carts, will always be placed in the same position and facing the same direction, and the transported objects are often placed out of place. It is not easy to get an automated guided vehicle to slip under the transported objects placed in the appropriate place.

[0007] In view of the above, an object of the present invention is to provide an automated guided vehicle that can properly slip under an object to be carried. [Means for solving the problem]

[0008] The unmanned guided vehicle of the present invention is an unmanned guided vehicle that slips under a transported object and lifts or tows the object to transport it, and is equipped with an optical reading device that photographs the area around the unmanned guided vehicle, a marker reading unit that detects a marker attached to the transported object from the image photographed by the optical reading device and reads the detected marker, and a movement control unit that controls the movement of the unmanned guided vehicle, wherein the movement control unit is configured to set a target in front of the transported object based on the position of the marker, control the movement of the unmanned guided vehicle to the position of the target, read the marker again when the unmanned guided vehicle arrives at the target position, and control the movement of the unmanned guided vehicle under the transported object based on the information read from the marker.

[0009] In this way, the automated guided vehicle is moved to a target position set in front of the transported object based on the information read from the marker, and once it has reached the target position, the marker is read again to control the movement of the automated guided vehicle, thereby enabling the automated guided vehicle to slip under the transported object while reducing the computational load.

[0010] In the unmanned guided vehicle of the present invention, the movement control unit may read the marker again when the unmanned guided vehicle arrives at the position of the target, set a second target under the transported object based on the position of the marker, and control the unmanned guided vehicle to move to the position of the second target.

[0011] In the automated guided vehicle of the present invention, the marker includes data indicating the position where the marker is attached relative to the transported object, and the movement control unit may identify the position and orientation of the transported object based on the position of the marker detected from the image and the data indicating the position where the marker is affixed, and set the target in front of the transported object.

[0012] With this configuration, the target can be set at an appropriate position in front of the transported object, regardless of the position of the marker on the transported object.

[0013] In the automated guided vehicle of the present invention, the marker may include data indicating dimensions of the transported object, and the movement control unit may set the second target under the transported object based on the data indicating the dimensions of the transported object.

[0014] With this configuration, the second target can be set at an appropriate position below the transported object based on the dimensions of the transported object.

[0015] In the automated guided vehicle of the present invention, the marker may include data indicating a weight of the transported object, and the movement control unit may set a maximum speed based on the data indicating the weight. With this configuration, the transported object can be transported at a safe speed according to the weight of the transported object.

[0016] The unmanned guided vehicle of the present invention may be provided with object detection sensors at the front and rear ends of the unmanned guided vehicle for detecting an object above, and when the movement control unit moves the unmanned guided vehicle under the transported load, the movement control unit may stop the unmanned guided vehicle after confirming that the object detection sensors do not detect an object.

[0017] By making the front and rear of the automatic guided vehicle extend beyond the load, the automatic guided vehicle can be stopped at a position that makes it easy to transport the load.

[0018] In the automated guided vehicle of the present invention, the marker may include marker ID data for identifying the marker, and the marker reading unit may read the marker ID from the marker and store the read marker ID in a memory unit.

[0019] By recording the marker ID attached to the object transported by the automatic guided vehicle in this manner, the object transported by the automatic guided vehicle can be identified.

[0020] In the automated guided vehicle of the present invention, the marker may include data of a destination of the transported object to which the marker is attached, and the movement control unit may transport the transported object to a predetermined location based on the destination data.

[0021] By transporting the transported object to a location according to the destination in this manner, it becomes easy to load the object onto a truck or the like heading for the destination, for example.

[0022] In the automated guided vehicle of the present invention, all wheels may be drivable and steerable. With this configuration, even if there is an error in the arrival position at the target, the automated guided vehicle can be moved to the second target while correcting the error.

[0023] The control method for an unmanned guided vehicle of the present invention is a control method for an unmanned guided vehicle that slips under a transported object and lifts or tows the transported object to transport it, and includes the steps of photographing the area around the unmanned guided vehicle with an optical reading device, detecting a marker attached to the transported object from the image photographed by the optical reading device and reading the detected marker, setting a target in front of the transported object based on the position of the marker and moving the unmanned guided vehicle to the position of the target, and reading the marker again when the unmanned guided vehicle arrives at the target position, and moving the unmanned guided vehicle under the transported object based on the information read from the marker. Effect of the Invention

[0024] According to the present invention, it is possible to perform movement control so that an automated guided vehicle can get under a transported object while reducing the calculation load. [Brief description of the drawings]

[0025] [Figure 1] 1A is a diagram illustrating the configuration of an AMR, and FIG. 1B is a diagram illustrating the AMR in a state in which the AMR is lifting a workpiece W. [Diagram 2] FIG. 1 is a diagram showing an example of a basket cart transported by an AMR. [Diagram 3] FIG. 13 is a diagram showing an example of a cart having an AR marker attached to a back panel. [Figure 4] FIG. 2 is a block diagram for explaining the function of AMR. [Diagram 5] FIG. 1 is a diagram for explaining movement control of an AMR. [Figure 6] FIG. 1 is a diagram for explaining movement control of an AMR. [Figure 7] FIG. 1 is a diagram for explaining movement control of an AMR. [Figure 8] FIG. 1 is a diagram for explaining movement control of an AMR. [Figure 9] 13 is a flowchart showing the operation of movement control of an AMR. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Hereinafter, an automated guided vehicle according to the present embodiment will be described with reference to the drawings. Note that the following description is merely an example of a preferred embodiment, and is not intended to limit the invention described in the claims.

[0027] In this embodiment, an AMR (autonomous mobile robot) is used as an example of an automated guided vehicle, but the automated guided vehicle of the present invention is not limited to an AMR. Also, a cart is used as an example of a workpiece, but the AMR of this embodiment is not limited to a cart and can transport other cargo.

[0028] 1(a) and 1(b) are diagrams showing the configuration of the AMR 1 according to the present embodiment. The AMR 1 according to the present embodiment slips under a cart 20 and lifts up the cart 20 for transport. In the present embodiment, the AMR 1 appropriately slips under a cart 20 placed in any location.

[0029] 2 is a diagram showing an example of a basket cart 20 transported by the AMR 1. The basket cart 20 has a bottom plate 21 on which luggage is placed, a back panel 22, and two side panels 23. The basket cart 20 has casters 24, and the bottom plate 21 is raised above the floor surface. The AMR 1 slips between the bottom plate 21 and the floor surface, and lifts up the basket cart 20 for transport.

[0030] The front of the cart 20 is equipped with a safety bar 25 that spans two side panels 23. A name plate 26 is attached to the right side panel 23 of the cart 20 in FIG. 2. An AR marker M is attached to the center of the safety bar 25. The AR marker M is surrounded by a black frame, so it can be easily detected. The marker is not limited to an AR marker, and other markers such as a QR code (registered trademark) may be used.

[0031] The AMR 1 of this embodiment detects the AR marker M from an image of the surroundings captured by the camera 31, and controls the movement of the AMR 1 so that the AMR 1 slips under the cart 20 based on the information on the position of the AR marker M.

[0032] Various information may be encoded in the AR marker M. For example, ID data for identifying the AR marker M, data on the position where the AR marker M is attached on the cart 20, data on the dimensions of the cart 20, etc.

[0033] When ID data identifying the AR marker M is encoded, the AMR 1 becomes able to manage which basket cart 20 has been transported. The data on the position of the AR marker M is effective when the position at which the AR marker M is attached varies depending on the basket cart 20. For example, FIG. 3 shows an example in which the AR marker M is attached to the back panel 22. Note that when the AR marker M is attached, it is attached facing outward from the basket cart 20, so the back of the AR marker M is visible in FIG. 3. FIG. 3 shows the attachment position of the marker M.

[0034] When the AR marker M is attached to the back panel 22 of the cage cart 20, data indicating the relative position of the AR marker M as viewed from the center of the front of the cage cart 20 is encoded. This allows the AMR1 to determine where the center of the front of the cage cart 20 is, and to move appropriately under the cage cart 20. In addition, when the data on the dimensions of the cage cart 20 is encoded, the depth of the cage cart 20 is known, and therefore it is possible to determine how far forward the AMR1 should move when slipping under the cage cart 20.

[0035] Returning to Fig. 1(a) and Fig. 1(b), the configuration of the AMR1 will be described. Fig. 1(a) is a diagram showing the configuration of the AMR1. Fig. 1(b) is a diagram showing the AMR1 in a state in which the basket cart 20 is being lifted. The AMR1 has a roughly rectangular parallelepiped main body 11 that is long from front to back. In Fig. 1(a), the left side will be described as the front and the right side as the rear. In this embodiment, an AMR1 that lifts and transports a transported object will be described as an example, but the present invention can also be applied to an AMR1 that tows a transported object.

[0036] As shown in Fig. 1(b), the AMR 1 has two bars 12 extending in the front-rear direction on the top surface. Fig. 1(a) shows the two bars 12 in a lowered state, and Fig. 1(b) shows the two bars 12 in a raised state. Note that Fig. 1 shows an example of the AMR 1 having two bars 12 for lifting the cart 20, but the configuration for lifting the cart 20 is not limited to two bars 12, and for example, a single plate that can move up and down may be provided on the top surface of the AMR 1.

[0037] The AMR 1 gets under the cart 20 and raises the bar 12 upward as shown in FIG. 1(b), thereby lifting the cart 20 from the floor surface. The AMR 1 transports the cart 20 in a lifted state. The weight of the cart 20 that the AMR 1 can lift is, for example, 300 to 500 kg.

[0038] The AMR1 has two drive wheels 13R, 13L in the center in the front-to-rear direction (only the right drive wheel 13R is visible in the figure), and two swivel casters at the front and two at the rear. The number of swivel casters is not limited, and for example, there may be one at the front and one at the rear. The AMR1 also has a wireless LAN communication unit 14 at the front and an optical communication unit 15 on the side. The wireless LAN communication unit 14 and the optical communication unit 15 have a communication function, and can communicate, for example, with a vertical conveyor that conveys the AMR1 between upper and lower floors.

[0039] The AMR1 has a receiving head for wireless charging in the center of its bottom surface. The AMR1 can be charged by placing the receiving head close to and facing the wireless charging power supply unit.

[0040] Fig. 4 is a block diagram for explaining the functions of the AMR 1. Fig. 4 describes functions related to control for causing the AMR 1 to slip under the cart 20, but the AMR 1 has functions other than those shown in Fig. 4.

[0041] The AMR 1 includes a left driving wheel 13L, a right driving wheel 13R, a left wheel motor 43L, and a right wheel motor 43R as hardware for the drive system 42. By changing the rotational speed of the left and right driving wheels 13L, 13R, the AMR 1 can turn left and right and rotate.

[0042] The AMR1 is equipped with sensors 30 including a camera 31, a photoelectric sensor 32, and a wheel speed sensor 33. The camera 31 has a function of capturing images of the periphery of the AMR1. In this embodiment, the camera 31 is taken as an example of an optical reading device, but the AMR1 may be equipped with an optical reading device other than a camera (e.g., LiDAR, etc.). The photoelectric sensor 32 is provided at the front end and rear end of the AMR1 and has a function of detecting an object above. The wheel speed sensor 33 has a function of detecting the wheel speed from the rotation speed of the left and right drive wheels 13L, 13R. Note that, in this embodiment, an example has been described in which the photoelectric sensor 32 is used to detect an object above the AMR1, but a laser sensor, an ultrasonic sensor, etc. may also be used as an object detection sensor.

[0043] The AMR 1 has an image processing unit 34 that processes images captured by the camera 31, and a movement control unit 37 that controls the movement of the AMR 1. The image processing unit 34 and the movement control unit 37 are realized by reading an image processing program and a movement control program and executing them on a CPU. As hardware, the image processing unit 34 and the movement control unit 37 may be a single CPU, or may each have a CPU that performs its own processing.

[0044] The image processing unit 34 has a marker detection unit 35 and a marker reading unit 36. The marker detection unit 35 has a function of detecting an AR marker M from a camera image. In addition, the marker detection unit 35 has a function of analyzing the position and orientation of the camera 31 relative to the AR marker M from the position, orientation, and size of the marker captured in the image. By knowing the position and orientation of the camera 31 relative to the AR marker M, it is possible to identify the position and orientation of the AMR1 relative to the AR marker M. The marker reading unit 36 ​​has a function of reading data encoded in the AR marker M.

[0045] The movement control unit 37 has a target setting unit 38 , a route calculation unit 39 , a movement amount estimation unit 40 , and a control signal generation unit 41 .

[0046] The target setting unit 38 has a function of setting a first target and a second target based on the position of the AR marker M detected by the marker detection unit 35. The first target is a target for guiding the AMR1 to the front of the cart 20, and is set in front of the cart 20. The second target is a target for allowing the AMR1 to slip under the cart 20, and is set under the cart 20.

[0047] Here, a specific example will be described in which the AR marker M is attached to the center of the safety bar 25 of the cart 20 as shown in Fig. 2. The target setting unit 38 sets a first target at a position 1 m in front of the AR marker M based on the position of the AR marker M. The target setting unit 38 also sets a second target at a position 0.5 m behind the AR marker M.

[0048] Movement control of the AMR 1 using the first target and the second target will be described with reference to Fig. 5 to Fig. 8. Fig. 5 to Fig. 8 are diagrams showing the positional relationship between the cart 20 and the AMR 1 as viewed from above. An AR marker M is attached to the front of the cart 20.

[0049] As shown in Fig. 5, initially, the cart 20 and the AMR1 are placed in arbitrary positions. The AMR1 detects an AR marker M from the surrounding image, and sets a first target T1 at a position 1 m in front of the AR marker M. Next, the AMR1 moves to the position of the first target T1, as shown in Fig. 6. The AMR1 stops when its center reaches the first target T1. Next, the AMR1 detects an AR marker M from the surrounding image, and sets a second target T2 at a position 1 m behind the AR marker M.

[0050] The AMR1 rotates so as to face the second target T2 as shown in Fig. 7, and moves to the position of the second target T2 as shown in Fig. 8. The AMR1 stops when its center reaches the second target T2. By the above movement control, the AMR1 can slip under the cart 20.

[0051] The route calculation unit 39 has a function of calculating a route from the current position of the AMR1 to the destination, with the first target and the second target as the destination. As an example, as shown in Figs. 6 and 8, a linear route moving toward the first target T1 and the second target T2 is calculated. If there is an obstacle on the way, the route calculation unit 39 may calculate a route that avoids the obstacle. In Fig. 6, the AMR1 does not face the direction of the cart 20 when the AMR1 arrives at the first target, but a route may be calculated in which the AMR1 moves while changing its direction so that the AMR1 faces the cart 20 when the AMR1 arrives at the first target (i.e., the state shown in Fig. 7).

[0052] The movement amount estimation unit 40 has a function of estimating in which direction and how far the AMR 1 has moved when it moves. The movement amount estimation unit 40 calculates the movement direction and movement amount of the AMR 1 based on the left and right wheel speeds acquired by the wheel speed sensor 33. This enables the AMR 1 to estimate its own position and to move along the calculated route without obtaining the position of the AR marker M during movement.

[0053] The control signal generation unit 41 has the function of generating control signals instructing the wheel speeds of the left driving wheel 13L and the right driving wheel 13R for moving the AMR 1 along a route, and transmitting the control signals to the left wheel motor 43L and the right wheel motor 43R.

[0054] FIG. 9 is a flowchart showing the movement control operation of the AMR1. The AMR1 first captures the surroundings with the camera 31, acquires a camera image, and detects the AR marker M from the camera image (S10). The AMR1 sets a first target at a position 1 m ahead of the AR marker M (S11), and calculates a route from the current position to the position of the first target (S12). The AMR1 performs movement control according to the route obtained by the calculation (S13). It is determined whether the AMR1 has arrived at the first target (S14). Specifically, the AMR1 estimates the current position by the movement amount estimation unit 40, and determines whether the current position coincides with the first target. If the AMR1 has not arrived at the first target (NO in S14), it continues movement control until it arrives (S13).

[0055] When the AMR1 arrives at the first target (YES in S14), the AMR1 photographs the surroundings with the camera 31, acquires a camera image, and detects the AR marker M from the camera image (S15). The AMR1 sets a second target at a position 0.5 m behind the AR marker M (S16), and calculates a route from the current position to the position of the second target (S17). The AMR1 performs movement control according to the route obtained by the calculation (S18). It is determined whether the AMR1 has arrived at the second target (S19). Specifically, the AMR1 estimates the current position using the movement amount estimation unit 40, and determines whether the current position coincides with the second target.

[0056] 8, when the AMR 1 is large enough to protrude from the front and rear of the cart 20, photoelectric sensors 32 provided at the front and rear ends of the AMR 1 may be used to confirm that there is no object above. This can ensure that the AMR 1 has slipped under the cart 20.

[0057] If the AMR1 has not arrived at the second target (NO in S19), movement control is continued until it arrives (S18). If the AMR1 has arrived at the second target (YES in S19), movement control is ended.

[0058] The AMR1 of this embodiment can slip under the cage cart 20 placed at any position by setting a first target and a second target based on the AR marker M attached to the cage cart 20 and controlling the movement of the cage cart 20 to move to the first target and the second target. When the first target and the second target are set, the AR marker M is detected, but while the AMR1 is moving, the movement amount estimation unit 40 estimates the position of the AMR1 and controls the movement. In this way, the number of times of detection of the AR marker M and self-position estimation based on the detected AR marker M can be reduced, and the load of the calculation process can be reduced. Since the AMR1 of this embodiment can slip under the cage cart 20 placed at any position, it can be transported even if the cage cart 20 is not properly aligned. For example, the AMR1 can transport the cage cart 20 by simply placing the cage cart 20 in the station.

[0059] The AMR 1 and its movement control according to this embodiment have been described above, but the automated guided vehicle of the present invention is not limited to the above embodiment. In the above embodiment, an example was given in which the movement direction of the AMR 1 is calculated based on the left and right wheel speeds acquired by the left and right wheel speed sensors 33, but the AMR 1 may also be provided with a steering sensor and the movement direction may be detected based on the steering angle.

[0060] In the above embodiment, the cage cart 20 with the AR marker M attached at the front center has been described as an example, but the position at which the AR marker M is attached is not limited to the front center of the cage cart 20. For example, as shown in Fig. 3, the AR marker M may be attached to the side panel 23 of the cage cart 20, and in that case, the target setting unit 38 sets the first target in consideration of the position at which the AR marker M at which the first target is set is attached.

[0061] When the AR marker M is attached to a location other than the center of the cart 20, data indicating how much the location where the AR marker M is attached is shifted from the center is encoded into the AR marker M. The AMR 1 reads the data on the amount of shift encoded in the AR marker M with the marker reading unit 36, and sets the first target at a position shifted by the amount of the read data. For example, when data that "the attachment position of the AR marker is 50 cm to the left of the center of the cart 20" is read, the first target is set at a position 1 m in front of the AR marker M and shifted 50 cm to the right.

[0062] In the above embodiment, the second target is set at a position a certain distance behind the AR marker M, but the second target may be set according to the size of the cage cart 20. Specifically, depth data in the front-rear direction of the cage cart 20 is encoded in the AR marker M as data on the size of the cage cart 20. The AMR 1 reads the depth data encoded in the AR marker M with the marker reading unit 36, and sets the second target in the center of the cage cart 20 in the depth direction. For example, if the depth of the cage cart 20 is 120 cm, the second target is set at a position 60 cm behind the AR marker M. This configuration can be applied to cage carts 20 of various sizes.

[0063] In the above embodiment, an example has been described in which the AMR 1 sets a second target after arriving at a first target, and the AMR 1 is moved toward the second target, but it is optional to set a second target when performing movement control to make the AMR 1 slip under the cart 20. The AMR 1 may be moved under the cart 20 based on information read from the marker M without setting a second target.

[0064] Furthermore, data other than the data described in the above embodiment may be encoded in the AR marker M. For example, when the basket cart 20 is used at a logistics site, the location where the basket cart 20 is collected may differ depending on the transport destination. In such a case, data on the transport destination of the basket cart 20 to which the AR marker M is attached is included. The AMR 1 can read the transport destination data from the AR marker M and transport the basket cart 20 to the corresponding collection location depending on the destination.

[0065] Information regarding the load weight of the cage cart 20 may be encoded in the AR marker M. This allows the AMR 1 to transport the cage cart 20 safely at a speed according to the load weight. Furthermore, in a system having a plurality of different types of AMRs, control can be performed so that an appropriate AMR transports the cage cart 20 according to the load weight of the cage cart 20.

[0066] In the above embodiment, the AMR 1 is provided with two drive wheels 13 on the left and right and two swivel casters on the front and rear, but all the wheels of the AMR 1 may be drivable and steerable. This allows the AMR 1 to move laterally, so that the transport of the cart 20 can begin in the lateral direction of the direction in which the AMR 1 has entered. This also enables the AMR 1 to move around obstacles and is less susceptible to the effects of unevenness in the road surface.

[0067] In the above embodiment, an example has been given in which the AR marker M is attached to the front of the cart 20, but the position of the AR marker M is not limited to the front, and may be on the side. Furthermore, the direction in which the AMR 1 slips under the cart 20 is not limited to the front, and may be from the side or rear. If the AMR 1 slips under the cart 20 from the side to which the AR marker M is attached, then it is sufficient to set a first target in front of the AR marker M, and the first target can be set with high accuracy. [Explanation of symbols]

[0068] 1 AMR 11 Main unit 12 Bar 13L,13R wheels 14 Wireless LAN communication section 15 Optical Communications Department 20 Basket Cart 21 Bottom plate 22 Back Panel 23 Side Panel 24 Caster 24 25 Safety Bar 26 name board 30 Sensors 31 Camera 32 Photoelectric Sensor 33 Wheel speed sensor 34 Image processing section 35 Marker detection unit 36 Marker reading unit 37 Movement control section 38 Target Setting Section 39 Route Calculation Unit 40 Movement amount estimator 41 Control signal generator 42 Drive system 43L, 43R Wheel motor MAR marker T1 First Target T2 Second Target

Claims

1. An automated guided vehicle that slides under an object to lift or tow the object and transport it, An optical reader that captures an image of the periphery of the automated guided vehicle; a marker reading unit that detects a marker attached to the transported object from the image captured by the optical reading device and reads the detected marker; A movement control unit that controls the movement of the automated guided vehicle; Equipped with the movement control unit sets a target in front of the transported object based on the position of the marker, and controls the automatic guided vehicle to move to the position of the target; The automated guided vehicle reads the marker again when it arrives at the target position, and controls the automated guided vehicle to move under the transported object based on the information read from the marker.

2. 2. The automated guided vehicle according to claim 1, wherein the movement control unit reads the marker again when the automated guided vehicle arrives at the position of the target, sets a second target under the transported object based on the position of the marker, and controls the automated guided vehicle to move to the position of the second target.

3. The marker includes data indicating a position where the marker is attached to the transported object, The automated guided vehicle according to claim 1 , wherein the movement control unit identifies a position and orientation of the transported object based on a position of the marker detected from the image and data indicating a position where the marker is affixed, and sets the target in front of the transported object.

4. the marker includes data indicating a dimension of the transported object; The automated guided vehicle according to claim 2 , wherein the movement control unit sets the second target below the transported object based on data indicating a size of the transported object.

5. the marker includes data indicating a weight of the transported object, The automated guided vehicle according to claim 1 , wherein the movement control unit sets a maximum speed based on the data indicating the weight.

6. an object detection sensor for detecting an object above is provided at a front end and a rear end of the automated guided vehicle; 2. The automated guided vehicle according to claim 1, wherein the movement control unit stops the automated guided vehicle after confirming that the object detection sensor does not detect an object when moving the automated guided vehicle under the transported object.

7. The marker includes marker ID data for identifying the marker, The automated guided vehicle according to claim 1 , wherein the marker reader reads a marker ID from the marker and stores the read marker ID in a storage unit.

8. The marker includes data of a destination of the transported object to which the marker is attached, The automated guided vehicle according to claim 1 , wherein the movement control unit transports the transported object to a predetermined location based on the data of the destination.

9. 2. The automated guided vehicle of claim 1, wherein all wheels of the automated guided vehicle are drivable and steerable.

10. A method for controlling an automated guided vehicle that moves under an object to lift or tow the object and transport it, comprising the steps of: Taking an image of the surroundings of the automated guided vehicle by an optical reader; detecting a marker attached to the transported object from the image captured by the optical reader and reading the detected marker; setting a target in front of the transported object based on the position of the marker, and moving the automated guided vehicle to the position of the target; reading the marker again when the automated guided vehicle arrives at the target position, and moving the automated guided vehicle under the transported object based on the information read from the marker; A method for controlling an automated guided vehicle comprising:

Images