JP2024038773A - automated guided vehicle - Google Patents

Abstract

[Problem] To provide an automated guided vehicle with improved reliability in connection between the automated guided vehicle and the towed object by stabilizing the recognition of the marker of the towed object by the camera of the automated guided vehicle. [Solution] An automated guided vehicle (10) tows a towed object (12) having a connectable connectable part (17) and a marker (19) for position recognition. An automated guided vehicle body (21) of the automated guided vehicle (10) runs on a running surface (11). A coupling unit (22) protrudes outward from the automated guided vehicle body (21) and is detachably connected to the connectable part (17) of the towed object (12). A camera (23) has a central axis (56) of a field of view in the horizontal direction and is disposed at a height where the marker (19) is located on the central axis (56) of the field of view, and recognizes the marker (19). A marker processing unit estimates the relative positional relationship between the automated guided vehicle body (21) and the towed object (12) from the marker (19) recognized by the camera (23). [Selected Figure] FIG.

Description

The present invention relates to an automatic guided vehicle that pulls a towed object.

BACKGROUND ART Conventionally, as described in Patent Document 1 below, for example, an automatic guided vehicle has been known that connects with the towed object to tow the towed object.

In such an automatic guided vehicle, for example, as described in Patent Document 2 below, a camera installed on the automatic guided vehicle recognizes a marker that a towed object has, and the automatic guided vehicle acquires a marker from the recognized marker. By using the relative positional relationship information between the vehicle and the towed object, it becomes possible to connect the automatic guided vehicle and the towed object.

Patent No. 6629436 Japanese Patent Application Publication No. 2020-17170

In this type of automatic guided vehicle, it is required that the camera of the automatic guided vehicle stably recognize the marker when performing the connection.

An object of the present invention is to provide an automatic guided vehicle in which the reliability of the connection between the automatic guided vehicle and the towed object is improved by stabilizing the recognition of the marker of the towed object by the camera of the automatic guided vehicle.

The automatic guided vehicle of the present invention is an automatic guided vehicle that pulls a towed object having a connectable connected part and a marker for position recognition, and includes an automatic guided vehicle main body that runs on a running surface, and a a connecting unit that projects outward from the vehicle body and is removably connected to the connected portion of the towed object; a central axis of the visual field is set in a horizontal direction, and the marker is positioned on the central axis of the visual field; a camera disposed at a height that recognizes the marker, and a marker processing unit that estimates a relative positional relationship between the automatic guided vehicle main body and the towed object from the marker recognized by the camera. Be prepared.

According to the automatic guided vehicle of the present invention, the reliability of the connection between the automatic guided vehicle and the towed object can be improved by stabilizing the recognition of the marker of the towed object by the camera of the automatic guided vehicle.

1 is a diagram illustrating an automatic guided vehicle according to an embodiment of the present invention and a towed object before being connected, FIG. 1A being a plan view and FIG. The same automatic guided vehicle and the towed object are shown in the middle of connection, (a) is a plan view, and (b) is a side view. It shows the automatic guided vehicle and the towed object after the connection is completed, and (a) is a plan view and (b) is a side view. It is a perspective view of the connection unit and camera of the automatic guided vehicle same as the above. It is a perspective view of a towed object towed by the same automatic guided vehicle.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

An automatic guided vehicle 10 is shown in FIGS. 1 to 3. The automatic guided vehicle 10 is a vehicle that automatically travels (autonomously) on a running surface 11 such as a floor, moves to a transport source where a towed object 12 is placed, and automatically moves the towed object 12 to be transported. The towed object 12 is connected to the towed object 12 and transported to the destination. Note that FIGS. 1 to 3 show only a part of the connection points of the towed object 12, and the overall structure of the towed object 12 is shown in FIG.

First, the towed object 12 will be explained. As shown in FIG. 5, the towed object 12 is, for example, a car truck or a trolley that can run on the running surface 11. The towed object 12 includes an elongated loading platform 14, a plurality of frame sections 15 disposed at each longitudinal end and center position on the lower surface side of the loading platform 14, and the lower surface of these frame sections 15. It is equipped with a plurality of wheels 16 arranged on the side. The frame portion 15 is formed into a rectangular cylindrical shape that is long in the width direction of the towed object 12 that intersects with the longitudinal direction of the loading platform portion 14 .

A central region in the width direction of the frame portion 15 located at at least one end of the towed object 12 is used as a connected portion 17 to which the automatic guided vehicle 10 can be connected. This connected portion 17 is provided with a hole portion 18 which is a square connecting hole at the center of the lower surface of the frame portion 15 in the width direction (horizontal direction). In addition, on the outer end surface 15a of the frame portion 15 at at least one end portion corresponding to the longitudinal direction of the loading platform portion 14, a predetermined distance deviated to one side from the center of the width direction (horizontal direction) of the connected portion 17 is provided. A marker 19 is arranged at the position (offset position). When the automatic guided vehicle 10 is connected to the towed object 12, the marker 19 recognizes the positional relationship such as the relative distance and posture between the automatic guided vehicle 10 and the towed object 12 using a camera included in the automatic guided vehicle 10. A pattern design is drawn that makes it possible to use, for example, a so-called AR marker. The marker 19 is, for example, a sticker, and by pasting it on the end surface 15a of the frame portion 15, a recognition function can be easily added. Note that the marker 19 may include readable information such as identification information such as unique ID information of the towed object 12, and in addition to the marker 19, identification information of the towed object 12, etc. There may be an identification display displaying readable information.

Next, the automatic guided vehicle 10 will be explained. As shown in FIGS. 1 to 3, the automatic guided vehicle 10 connects an automatic guided vehicle main body 21 and a towed object 12 disposed on the rear side opposite to the forward direction of the automatic guided vehicle main body 21. A camera 23 that recognizes the connecting unit 22 and the marker 19, a control device that controls the automatic guided vehicle 10 mounted in the automatic guided vehicle body 21, a battery that supplies power, and the like are provided.

The automatic guided vehicle main body 21 is made movable by a pair of running wheels 25 arranged on both sides in the left-right direction, which is the width direction, and a plurality of rotatable casters 26 as a running part. Each running wheel 25 is a running wheel motor that can be rotated individually, and by controlling the rotational drive of each running wheel motor, various types of running such as forward movement, backward movement, curve movement, and spin movement are possible. Further, the automatic guided vehicle main body 21 includes a traction device rotatably disposed on the traveling section, and a connecting unit 22 and a camera 23 disposed on the rear side of the traction device. Further, in the case of the automatic guided vehicle main body 21 in which the traction device on the traveling section rotates 360 degrees, the automatic guided vehicle main body 21 may move forward instead of retreating when connecting the towed object 12.

As shown in FIGS. 1 to 4, the connection unit 22 is provided with an elevating section 28 that moves up and down relative to the automatic guided vehicle main body 21, and on this elevating section 28. When the main body 21 retreats (moves closer to the towed object 12), it enters below the frame portion 15 of the towed object 12, and as the elevating portion 28 rises, it enters the frame portion 15 (connected portion 17) of the towed object 12. It has a connecting part 29 that is connected from below, and a contact part 30 that can come into contact with the end surface 15a of the frame part 15 of the towed object 12 when the automatic guided vehicle main body 21 retreats during the connection.

The elevating section 28 has a vertically elongated elevating arm 32 disposed on the rear side of the automatic guided vehicle main body 21. The elevating arm 32 is supported so as to be vertically movable by an elevating mechanism using a cam, for example, provided on the automatic guided vehicle body 21. The lifting arm 32 has two positions: a raised position where the connecting portion 29 is connected to the frame portion 15 of the towed object 12 from below and a lowered position where the connecting portion 29 releases the frame portion 15 of the towed object 12 by the operation of the lifting mechanism. It is raised and lowered.

The connecting portion 29 has a connecting arm 34 that is attached to the lower end of the lifting arm 32 and projects horizontally from the rear surface of the automatic guided vehicle body 21 toward the rear. The connecting arm 34 has a substantially U-shaped cross section, and has an upper surface portion 35 and side portions 36 bent from both left and right sides of the upper surface portion 35 .

On the connecting arm 34, a front guide roller 37 and a rear guide roller 38 are arranged at a predetermined interval in the front-rear direction. The front guide roller 37 is rotatably attached to a support shaft 40 installed between front support members 39 attached to both left and right sides of the connecting arm 34 and left and right sides of the lifting arm 32, respectively. The axial direction of the support shaft 40 is arranged horizontally along the left-right direction of the connecting portion 29, and the front guide roller 37 is rotatable about the support shaft 40. Further, the rear guide roller 38 is rotatably attached to a support shaft 42 installed between rear support members 41 attached to both left and right sides of the connecting arm 34 . The axial direction of the support shaft 42 is arranged horizontally along the left-right direction of the connecting portion 29, and the rear guide roller 38 is rotatable about the support shaft 42.

The front guide roller 37 and the rear guide roller 38 each include four rollers, and two rollers each are arranged with an interval in the left-right direction. The interval between the two rollers is such that the front guide roller 37 is wider than the rear guide roller 38, and the front guide roller 37 is arranged at a position wider outward in the left-right direction than the rear guide roller 38. ing.

The front guide roller 37 and the rear guide roller 38 are arranged at the same height from the top surface of the connecting arm 34. The front guide roller 37 and the rear guide roller 38 are arranged at a position lower than the lower surface of the frame portion 15 of the towed object 12 when the elevating portion 28 is lowered to the lowered position.

The front guide roller 37 and the rear guide roller 38 move up and down the frame 15 of the towed object 12 as the elevating part 28 rises, thereby sandwiching and connecting the frame 15 from the front and back. That is, the connecting portion 29 guides the frame portion of the towed object 12, such as a car truck or a truck, by a guide portion including guide rollers 37 and 38, thereby leading to the connection. The circumferential surfaces of the guide rollers 37 and 38 are made of a flexible material such as rubber. Note that the shortest distance between the front guide roller 37 and the rear guide roller 38 can be made approximately the same as or slightly wider than the width of the frame portion 15 in the front-rear direction, and the guide rollers 37 and 38 The towed object 12 may be connected to the towed object 12 by sandwiching the part 15 or the frame portion of the towed object 12 such as a car truck or trolley, and the shortest distance between the front guide roller 37 and the rear guide roller 38 is The relationship may be a little narrower than the width of the frame portion 15 in the front-rear direction within the range of flexibility of the peripheral surface.

Further, on the connecting arm 34, a connecting protrusion 43 projects upward at a position between the front guide roller 37 and the rear guide roller 38. The connecting protrusion 43 has a width in the front-rear direction that is smaller than a width in the left-right direction, and the upper surface side is formed in a substantially triangular shape in the left-right direction. Note that the shape of the connecting protrusion 43 can be changed depending on the shape of the hole 18.

The upper end of the connecting protrusion 43 is located lower than the upper surfaces of the guide rollers 37, 38 and higher than the center of the guide rollers 37, 38. The connecting protrusion 43 is arranged at a position lower than the lower surface of the frame portion 15 of the towed object 12 when the elevating portion 28 is lowered to the lowered position. When the front guide roller 37 and the rear guide roller 38 move up and down the frame 15 of the towed object 12 to guide and position the frame 15 from the front and back, the connecting protrusion 43 is connected to the frame. 15 into the hole 18 from below.

Further, the contact portion 30 includes a contact roller 45 . The contact roller 45 is rotatably attached to a support shaft 46 installed between the upper ends of front support members 39 attached to both left and right sides of the connecting arm 34 and left and right sides of the lifting arm 32, respectively. The axial direction of the support shaft 46 is arranged horizontally along the left-right direction of the connecting portion 29, and the contact roller 45 can rotate around the support shaft 46.

The contact roller 45 is composed of four rollers, and two rollers each are spaced apart from each other in the left-right direction. The contact roller 45 has a smaller diameter than the guide rollers 37 and 38, and is arranged at a position closer to the inside of the guide rollers 37 and 38 in the left-right direction.

The contact roller 45 is located at a higher height from the top surface of the connecting arm 34 than the guide rollers 37 and 38, and the rear surface side of the contact roller 45 is in front of the rear surface side of the front guide roller 37, and the front side guide It is arranged at a position behind the center of the roller 37. The contact roller 45 is at the same height as the end surface 15a of the frame portion 15 of the towed object 12 when the elevating portion 28 is lowered to the lowered position, and is capable of contacting the end surface 15a of the frame portion 15. placed at a height.

The circumferential surface of the contact roller 45 is made of a flexible material such as rubber or urethane, and is made of a material that has a cushioning effect when it comes into contact with the end surface 15a of the frame portion 15. Therefore, the contact section 30 also serves as a buffer section that buffers the impact when it comes into contact with the end surface 15a of the frame section 15.

Note that, as shown in FIG. 4, the lifting arm 32 of the lifting section 28 is covered with a cover 48 provided on the automatic guided vehicle main body 21. The lifting arm 32 is arranged to be movable up and down within the cover 48, which has a constant height. The cover 48 is provided with a concave surface 50 recessed from the side surface of the automatic guided vehicle main body 21 and recessed forward from the rearmost position of the rear surface 49 of the automatic guided vehicle main body 21. An opening 51 is provided in which the connecting portion 29 protrudes rearward and allows the connecting portion 29 to be raised and lowered.

Further, the camera 23 includes a camera housing 53, a photographing section 54, and an infrared irradiating section 55 disposed in the camera housing 53. The photographing unit 54 includes, for example, an image sensor such as an RGB-IR sensor, a lens that focuses light on a subject on the image sensor, and the like. The infrared irradiation section 55 irradiates infrared rays to enable the photographing section 54 to take pictures even in a dark place.

The camera 23 is disposed on a concave surface 50 that is recessed forward from the rearmost position of the rear surface 49 of the automatic guided vehicle body 21. The camera 23 is disposed on one side in the left-right direction (horizontal direction) of the opening 51 of the concave surface 50 from which the connection unit 22 projects. The camera 23 is disposed on the automatic guided vehicle main body 21 with the camera housing 53 being vertically elongated, the photographing section 54 is disposed on the lower side, and the infrared ray irradiation section 55 is disposed on the upper side. The camera 23 is disposed at a constant height position of the automatic guided vehicle body 21 while the connection unit 22 moves up and down with respect to the automatic guided vehicle body 21.

The camera 23 is disposed on the rear surface of the automatic guided vehicle body 21 at a position shifted by a predetermined distance to one side from the center of the connection unit 22 in the left-right direction. A predetermined distance shifted to one side from the center of the connecting unit 22 in the left-right direction means that the marker 19 of the towed object 12 is shifted to one side from the center of the hole 18 of the frame part 15 (connected part 17). is the same as the predetermined distance. Therefore, when the horizontal center of the connecting unit 22 and the horizontal center of the hole 18 of the frame portion 15 (connected portion 17) match, the positions of the camera 23 and the marker 19 in the horizontal direction match. . That is, the central axis 56 of the field of view of the camera 23 is aligned with the center of the marker 19 in the left-right direction.

The camera 23 has a central axis of field of view 56 perpendicular to the center of the image sensor of the photographing section 54, and is capable of photographing within a predetermined viewing angle centered on this central axis of field of view 56. The central axis 56 of the field of view of the camera 23 is parallel to the protruding direction of the connecting unit 22 in both the horizontal and vertical directions, and is parallel to the running surface 11 in the horizontal direction toward the rear of the automatic guided vehicle body 21. This is the direction. The height of the center axis 56 of the field of view from the running surface 11 matches the height of the center of the marker 19 of the towed object 12 from the running surface 11, and the center of the marker 19 is located on the extension of the center axis 56 of the field of view. is located.

In other words, at a position of the automatic guided vehicle main body 21 where the central axis 56 of the field of view of the camera 23 is perpendicular to the marker 19, the horizontal center of the connecting portion 29 of the connecting unit 22 and the connected portion 17 of the towed object 12 and the center of the hole 18 in the left-right direction coincide with each other.

Note that matching here does not necessarily require exact matching, but may include a position where the marker 19 is within a range that does not hinder recognition near the center of the field of view of the camera 23.

The angle of view of the camera 23 is, for example, a rectangle with a ratio of 16:9, and is arranged so that the longitudinal direction of the angle of view is in the vertical direction. (the range of the horizontal viewing angle is indicated by y) is larger than the horizontal viewing angle (the range of the horizontal viewing angle is indicated by x in FIGS. 1 to 3).

The control device of the automatic guided vehicle 10 also includes a marker processing unit that estimates the relative positional relationship between the automatic guided vehicle 10 and the towed object 12 based on recognition of the marker 19 of the towed object 12 by the camera 23. , a travel control unit that controls the drive of the running wheels 25 to automatically travel the automatic guided vehicle 10 on the travel surface 11 including between the transport source and the transport destination of the towed object 12; and controls the operation of the connecting unit 29. The automatic guided vehicle 10 has the function of a connection control section that controls the connection of the automatic guided vehicle 10 with the towed object 12.

Next, the operation of the automatic guided vehicle 10 will be explained.

FIG. 1 shows a state in which the automatic guided vehicle 10 is before the towed object 12 is connected to the towed object 12 or after the automatic guided vehicle 10 is disconnected from the towed object 12.

In this state, the elevating portion 28 of the connecting unit 22 is lowered to the lowered position, and the guide rollers 37 and 38 and the connecting protrusion 43 of the connecting portion 29 are at a position lower than the frame portion 15 of the towed object 12. Further, the height of the central axis 56 of the field of view of the camera 23 is located at a position that matches the height of the marker 19 of the towed object 12.

Then, as shown in FIG. 1, the automatic guided vehicle 10 moves to a position facing the end surface 15a of the frame 15 on the connected portion 17 side of the towed object 12 at the location where the towed object 12 is transported. , the rear side of the automatic guided vehicle 10 is made to face the towed object 12. As a result, the marker 19 of the towed object 12 comes into the field of view of the camera 23, and the camera 23 recognizes the marker 19, thereby estimating the relative positional relationship between the automatic guided vehicle 10 and the towed object 12.

While retreating to approach the towed object 12 , the automatic guided vehicle 10 aligns the central axis 56 of the field of view of the camera 23 with the marker 19 based on the positional relationship with the towed object 12 and moves toward the marker 19 . Correct the position and direction of the retreat so that it is vertical.

As the automatic guided vehicle 10 moves backward, the connecting portion 29 of the connecting unit 22 enters below the frame portion 15 of the towed object 12, as shown in FIG. Even while the automatic guided vehicle 10 is retreating, the camera 23 continues to recognize the marker 19.

Based on the recognition of the marker 19 by the camera 23, when the distance between the automatic guided vehicle 10 and the towed object 12 reaches a predetermined distance, the backward movement of the automatic guided vehicle 10 is stopped. At this time, the position where the automatic guided vehicle 10 stops retreating is a position between the guide rollers 37 and 38 before and after the connecting part 29 is below the frame part 15 of the towed object 12, and the connecting part 29 is raised. This is the position where it can be connected to the frame portion 15 of the towed object 12.

If the automatic guided vehicle 10 moves backward too much when stopping, the contact roller 45 of the contact portion 30 may come into contact with the end surface 15a of the frame portion 15 of the towed object 12, as shown in FIG. . Due to this contact, the connecting portion 29 is positioned so as not to come out of the position where it can be connected to the frame portion 15 of the towed object 12. Since the contact roller 45 of the contact portion 30 has a buffering effect, it prevents the towed object 12 from moving largely away from the automatic guided vehicle 10 due to the reaction of the collision with the contact roller 45 and being displaced from the connection position. It can be prevented. In addition, in the backward movement in which the automatic guided vehicle 10 approaches the towed object 12, the towed object may be brought closer until it constantly contacts the contact roller 45.

Subsequently, as shown in FIG. 3, the automatic guided vehicle 10 raises the connecting part 29 together with the lifting part 28 of the connecting unit 22 to the raised position. As the connecting portion 29 rises, the front guide roller 37 and the rear guide roller 38 move upwardly toward the front and rear of the frame portion 15 of the towed object 12 to guide and connect the frame portion 15 from the front and rear. At this time, the front and rear guide rollers 37 and 38 contact from the front and rear lower end sides of the frame part 15 and sandwich the frame part 15 from the front and back while rotating, so the front and rear guide rollers 37 and 38 and the front and rear positions of the frame part 15 Even if they are slightly shifted in the front-back direction, they can be stably connected.

As shown in FIG. 2, when the connecting portion 29 is raised in a state where the contact roller 45 of the contact portion 30 is in contact with the end surface 15a of the frame portion 15 of the towed object 12, the contact roller 45 is It rises while rotating relative to the end surface 15a of the portion 15, and furthermore, the circumferential surface of the front guide roller 37 comes into contact with the lower end portion of the frame portion 15 on the end surface 15a side. At this time, since the rear side of the contact roller 45 is arranged in a position that is forward of the rear side of the front guide roller 37 and behind the center of the front guide roller 37, the front guide roller 37 rises. When the circumferential surface of the frame 15 comes into contact with the lower end of the end surface 15a side of the frame 15, the towed object 12 is pushed while the front guide roller 37 rotates and pushes the frame 15 toward the rear guide roller 38. The frame portion 15 can be guided and connected by the front and rear guide rollers 37 and 38 that are moved and raised.

When the connecting portion 29 rises, the front and rear guide rollers 37 and 38 move upwardly in the front and back of the frame portion 15, whereby the positions of the connecting protrusion 43 and the hole portion 18 of the frame portion 15 in the front-rear direction are determined. Furthermore, when the automatic guided vehicle 10 is retreating for connection, the horizontal position of the connecting unit 22 of the automatic guided vehicle 10 and the connected portion 17 of the towed object 12 is determined based on the recognition of the marker 19 by the camera 23. Because of the positioning, the positions of the connecting protrusion 43 and the hole 18 of the frame portion 15 in the left-right direction are determined. Therefore, as the connecting portion 29 rises, the connecting protrusion 43 is inserted into the hole 18 of the frame portion 15 from below and connected to the frame portion 15. At this time, since the upper end side of the connecting protrusion 43 is formed in a substantially triangular shape in the left-right direction, if the top of the connecting protrusion 43 is inserted into the hole 18 of the frame 15, the connecting protrusion 43 and the hole of the frame 15 Even if the connecting protrusions 43 and 18 are slightly shifted in the left-right direction, the connecting protrusions 43 are inserted into the holes 18 of the frame 15. By inserting the connecting protrusion 43 into the hole 18 of the frame 15, the positions of the automatic guided vehicle 10 and the towed object 12 in the left-right direction are maintained.

Then, the automatic guided vehicle 10 to which the towed object 12 is connected moves forward, pulls the towed object 12, and moves to the destination.

Further, after the automatic guided vehicle 10 transports the towed object 12 to the destination, the automatic guided vehicle 10 releases the connection with the towed object 12.

The automatic guided vehicle 10 lowers the connecting part 29 to the lowered position together with the lifting part 28 of the connecting unit 22. As the connecting portion 29 descends, the front and rear guide rollers 37 and 38 smoothly descend while rotating relative to the frame portion 15, and are removed from the frame portion 15 to release the connection. Further, the connecting protrusion 43 comes off downward from the hole 18 of the frame 15 to release the connection.

After the connection is released, the automatic guided vehicle 10 moves forward (moves away from the towed object 12), and the connecting portion 29 of the connecting unit 22 comes off from below the frame portion 15 of the towed object 12.

In this way, in the automatic guided vehicle 10 of the present embodiment, the connected object 12 having the marker 19 at a position shifted to one side of the connected part 17 is targeted, and the camera 23 is mounted on the rear surface of the automatic guided vehicle main body 21. , is arranged at a position shifted to one side from the center of the connecting unit 22 in the left-right direction, and furthermore, the central axis 56 of the field of view of the camera 23 is in the horizontal direction toward the rear of the automatic guided vehicle body 21, and the field of view is Since the center of the marker 19 of the towed object 12 is located on the central axis 56, it is easy to recognize the displacement of the marker 19 of the towed object 12 near the center of the field of view of the camera 23, and the towed object 12 can be reliably connected.

That is, since the camera 23 can continue to recognize the marker 19 before, during, and after the connection is completed when the connection unit 22 is connected to the connected part 17 of the towed object 12, the automatic guided vehicle The positional relationship between the towed object 12 and the towed object 10 can be continuously estimated, the positional deviation can be corrected as necessary, and the towed object 12 can be reliably connected to the automatic guided vehicle 10.

Moreover, even if the connecting portion 29 that rises during connection fails to properly connect the frame portion 15 of the towed object 12 and lifts the frame portion 15 of the towed object 12, the connecting portion 29 that rises during connection will remain at a certain height from the running surface 11. A connection failure can be detected by recognizing that the marker 19 has moved upward with a camera 23 disposed at the top, and it is possible to take measures such as redoing the connection.

The central axis 56 of the field of view of the camera 23 is in the horizontal direction toward the rear of the automatic guided vehicle 10, and the height of the central axis 56 of the field of view from the running surface 11 is set to the marker 19 of the towed object 12 from the running surface 11. Even if the automatic guided vehicle 10 moves backward for connection, the marker 19 moves only in the horizontal direction within the field of view of the camera 23 and the amount of movement is small, making it difficult for the marker 19 to be recognized. This simplifies the correction process and makes it easier to recognize the marker 19.

Since the marker 19 is arranged on one side of the connected part 17 of the towed object 12 and the camera 23 is arranged on one side of the connection unit 22, the connected part 17 and the marker 19 are arranged close to each other. Therefore, as the connecting unit 22 and the connected part 17 approach, the marker 19 will be recognized larger near the center of the field of view of the camera 23, and the positional deviation with respect to the marker 19 will be easily found, and the connecting unit 22 will be more visible. The towed object 12 can be reliably connected to the position of the connected portion 17.

Therefore, in the automatic guided vehicle 10 of the present embodiment, the recognition of the marker 19 of the towed object 12 by the camera 23 is stabilized, thereby improving the reliability of the connection between the towed object 12 and the automatic guided vehicle 10 and the towed object 12. Objects 12 can be reliably connected.

In addition, since the abutment part 30 of the connecting unit 22 is arranged at the same height as the height on the straight line connecting the central axis 56 of the field of view of the camera 23 and the marker 19 at the lowered position of the elevating part 28, in other words, , because the central axis 56 of the field of view of the camera 23 is located at the same height as the contact part 30 that can contact the connected part 17 and at the same height as the marker 19. are located on the same axis, and the connected part 17 can be reliably brought into contact with the contact part 30 during the movement of the automatic guided vehicle 10 approaching the connected part 17 using the marker 19 as a reference.

Furthermore, since the camera 23 is provided on a concave surface 50 that is recessed forward from the rearmost position of the rear surface 49 of the automatic guided vehicle main body 21, when the automatic guided vehicle main body 21 approaches the towed object 12, It is possible to prevent the marker 19 from being removed from the field of view or the shortest photographing distance due to the camera 23 and the marker 19 coming too close to each other, thereby reducing the recognizability of the marker 19.

Further, since the camera 23 has a larger vertical viewing angle than the horizontal viewing angle, for example, the marker 19 may be placed on the frame 15 of the towed object 12 and at a position higher than the frame 15. In order to improve the recognition accuracy of the positional relationship, or to provide an identification display for identifying the towed object 12 at a higher position than the frame 15 in addition to the marker 19 provided on the frame 15 of the towed object 12, one camera can be used. It becomes possible to identify by 23.

Note that the connecting portion 29 of the connecting unit 22 can reliably connect the frame portion 15 of the towed object 12 by having the guide rollers 37, 38 and the connecting protrusion 43; Since the frame portion 15 of the retractable object 12 can be connected to either one of them, a configuration including only one of them may be used.

In addition, although the connecting operation of the connecting unit 22 is raised and lowered, for example, the connecting unit 29 can be moved by installing a separately installed rotation axis and swinging the guide rollers 37 and 38 around this rotation axis. The connected portion 17 may be more firmly held between the guide roller 37 and the guide roller 38 by connecting it to the connecting portion 17 or by moving one or both of the guide rollers 37 and 38 toward and away from each other.

Furthermore, instead of the guide rollers 37 and 38, a vertical surface on the center side and a taper on the upper side that is diagonally upward outward from the upper end of this vertical surface to absorb positional deviation are formed. It is also possible to use a guide piece.

In addition, in the connection unit 22, the structure has been described in which the contact portion 30, the guide rollers 37, 38, and the connection protrusion 43 move up and down as a unit; however, for example, the position of the contact portion 30 may be fixed, or the guide roller 37 , 38 and the connecting protrusion 43 may be raised and lowered separately from the contact portion 30. Furthermore, the contact portion 30 may use a shock absorbing member such as rubber or an absorber as a damper instead of a roller.

Furthermore, the markers 19 may be attached to two or more locations, and the number of cameras 23 can be increased according to the number of markers 19 installed. The position of the marker 19 can be adjusted in a timely manner according to the position of the marker 19. The camera 23 may use different sensors depending on the purpose, such as measuring the distance with a distance sensor and acquiring only the posture with an image sensor.

In addition, the automated guided vehicle in this case is not limited to one in which all operations such as traveling operation and coupling operation are performed automatically, but can also include those in which some operations can be performed by an operator. Passengers such as operators and drivers may also be on board.

Although the embodiments of the present invention and their modifications have been described above, various combinations of configurations, partial omissions, replacements, and changes are also possible.

10 Automatic guided vehicle 11 Running surface 12 Towed object 17 Connected part 19 Marker 21 Automatic guided vehicle main body 22 Connection unit 23 Camera 28 Elevating part 29 Connecting part 30 Contact part 50 Concave surface 56 Central axis of field of view

Claims (6)

An automated guided vehicle that tows a towed object having a connectable connected part and a marker for position recognition,
An automatic guided vehicle body that runs on a running surface,
a connection unit that projects outward from the automatic guided vehicle main body and is detachably connected to the connected portion of the towed object;
a camera that recognizes the marker, the central axis of the field of view being in the horizontal direction, and the camera disposed at a height such that the marker is located on the central axis of the field of view;
An automatic guided vehicle comprising: a marker processing unit that estimates a relative positional relationship between the automatic guided vehicle main body and the towed object from the marker recognized by the camera. The camera continues to recognize the marker before, during, and after the connection is completed when the connection unit is connected to the connected portion of the towed object. Unmanned guided vehicle. The connection unit is
It is arranged at the same height as the center axis of the field of view of the camera, and when the automatic guided vehicle moves and the connecting unit approaches the towed object, the connecting unit comes into contact with the towed object and is moved against the connecting unit. a contact portion that positions the connected portion;
a connecting part that connects with the connected part by operating on the connected part positioned with respect to the connecting unit,
The field of view of the camera continues to recognize the marker from before the abutting part contacts the connected part until the connecting part connects to the connected part. Unmanned guided vehicle. The connection unit is provided with an elevating part that ascends and descends with respect to the automatic guided vehicle main body, and is provided in this elevating part, and the coupled part of the towed object is connected to the towed object by traveling of the automatic guided vehicle main body at a lowered position of the elevating part. a connecting portion that enters below the vehicle and is connected from below to the connected portion of the towed object as the elevating portion rises; and a connecting portion that comes into contact with the connected portion of the towed object when the automatic guided vehicle main body is traveling. It has a contact part that allows contact,
The contact portion is arranged at the same height as the height on a straight line connecting the central axis of the field of view of the camera and the marker at the lowered position of the elevating portion. Unmanned guided vehicle. The automatic guided vehicle according to claim 1, wherein the camera is provided on a concave surface recessed from a side surface of the automatic guided vehicle main body. The automatic guided vehicle according to claim 1, wherein the camera has a vertical viewing angle larger than a horizontal viewing angle.

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