JP2022147405A - Transport device - Google Patents

Abstract

To provide a transport device capable of allowing an AGV to approach a position correctly connectable with respect to an object to be transported even in a narrow passage.SOLUTION: A transport device 1 includes: a body 2 having a driving wheel 3; a pair of forks 6 extending in a predetermined position from the body 2, and for lifting an object to be transported; driven wheels 5 provided at tips of the pair of forks 6; a lifting device 7 for moving up/down the pair of forks 6; a movement part for maintaining grounding of the driven wheel 5 by changing the relative distance between the driven wheel 5 and the fork 6 according to the moving up/down of the fork 6 by the lifting device 7; and a plurality of sensors 11 provided at the body part 2, and capable of detecting the position of the object to be transported.SELECTED DRAWING: Figure 1

Description

The present invention relates to a transport device.

In factories and distribution warehouses, it is common to use pallets, trolleys, and the like to transport goods. When automating the transportation in the above-described transportation mode with an AGV (Automatic Guided Vehicle), which is an example of a transportation device, it is necessary to accurately recognize the position where the object to be transported is placed and connect it reliably. Important for safety. In addition, there are many cases where pallets and carts are mixed in factories and distribution warehouses. In addition, there are various types of trucks, such as basket trucks and six-wheeled trucks. When automating the transportation process in such factories and distribution warehouses with AGVs, a forklift type AGV for transporting pallets, a hand pallet type AGV, and a traction type AGV for towing carts are required.

However, conventionally, when recognizing the position of an object to be transported, only one sensor is used that faces the connection part (for example, fork) with the object to be transported. In that case, the position of the object to be transported cannot be accurately recognized unless the connecting portion of the AGV is directed toward the object to be transported. In addition, even if a sensor with a detection area of 180° or more is used and can detect in the lateral direction, it is necessary to devise an arrangement in which a single sensor can detect 180° or more without blind spots.

In actual factories and distribution warehouses, it is sometimes difficult to secure a wide passageway for the AGV to travel. Width may not be secured.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a conveying apparatus capable of approaching an AGV to a position where it can be correctly connected to an object to be conveyed even in a narrow passage.

In order to solve the above-mentioned problems and achieve the object, the present invention provides a main body having driving wheels, a pair of forks extending in a predetermined direction from the main body for lifting an object to be transported, and the pair of a driven wheel provided at each tip of the forks; a lifting device for lifting and lowering the pair of forks; A moving part that keeps the driven wheel grounded, and a plurality of sensors that are provided on the main body and are capable of detecting the position of the object to be transported.

According to the present invention, it is possible to approach the AGV to a position where it can be correctly connected to an object to be transported even in a narrow passage.

FIG. 1 is a perspective view of a carrier according to this embodiment. FIG. 2 is a side view of the transport device according to this embodiment. FIG. 3 is a schematic side view of the link mechanism of the transport device according to this embodiment. FIG. 4 is a perspective view showing an example of the form of a pallet, which is an example of an object to be transported by the transporting device according to the present embodiment. FIG. 5 is a perspective view of a cage truck as an example of a truck that is an example of an object to be transported by the transporter according to the present embodiment. FIG. 6A is a plan view when the transport device according to the present embodiment recognizes the position of a pallet, which is an example of the object to be transported. FIG. 6B is a plan view when the transport device according to the present embodiment recognizes the position of a pallet, which is an example of the object to be transported. FIG. 7 is a flowchart showing an example of the flow of the pallet position detection operation by the transport device according to the present embodiment. FIG. 8A is a plan view when the transport device according to the present embodiment recognizes the position of the carriage of the object to be transported. FIG. 8B is a plan view when the transport device according to the present embodiment recognizes the position of the carriage of the object to be transported. FIG. 9 is a flow chart showing an example of the flow of the carriage position detection operation by the carrier device according to the present embodiment. FIG. 10A is a diagram for explaining an example of a trajectory when the transportation device according to the present embodiment recognizes the position of the object to be transported and then approaches the object to be transported to a position where the fork can be inserted. be. FIG. 10B is a diagram for explaining an example of a trajectory when the transportation device according to the present embodiment recognizes the position of the object to be transported and then approaches the object to be transported to a position where the fork can be inserted. be. FIG. 10C is a diagram for explaining an example of a trajectory when the transportation device according to the present embodiment recognizes the position of the object to be transported and then approaches the object to be transported to a position where the fork can be inserted. be. FIG. 10D is a diagram for explaining an example of a trajectory when the transportation device according to the present embodiment recognizes the position of the object to be transported and then approaches the object to be transported to a position where the fork can be inserted. be. FIG. 11 is a diagram showing an obstacle detection range of a range sensor included in the transportation device according to the present embodiment.

Exemplary embodiments of the carrier will be described in detail below with reference to the accompanying drawings. In order to facilitate understanding of the description, the same constituent elements in each drawing are denoted by the same reference numerals as much as possible, and overlapping descriptions are omitted.

In the following description, x-direction, y-direction, and z-direction are directions perpendicular to each other. The x and y directions are typically horizontal and the z direction is typically vertical. The x direction is the longitudinal direction of the pair of forks 6 . The y direction is the direction in which the pair of forks 6 are arranged and the direction in which the pair of forks 6 are opened and closed. In the following description, for convenience of explanation, the x negative direction side is the front side, the x positive direction side is the rear side, the y positive direction side is the right side, the y negative direction side is the left side, the z positive direction side is the upper side, and the z negative direction is The side may also be expressed as the bottom side.

The transport device 1 according to the present embodiment can hold a pallet 31 (see FIG. 4) and a carriage 41 (see FIG. 5, etc.) such as a car carriage, a six-wheeled carriage, and a dolly. By autonomously moving while being held, the pallet 31 and the carriage 41 as an object to be transported (object to be transported) can be transported to a desired position. It should be noted that the object to be transported by the transport device 1 includes an object having wheels other than the carriage 41 .

An example of the configuration of a carrier device 1 according to the present embodiment will be described with reference to FIGS. 1 to 3. FIG. FIG. 1 is a perspective view of a carrier according to this embodiment. FIG. 2 is a side view of the transport device according to this embodiment. FIG. 3 is a schematic side view of the link mechanism of the transport device according to this embodiment. As shown in FIG. 1, the transport device 1 includes a main body 2, a drive wheel 3, a drive motor 4, a pair of driven wheels 5, a pair of forks 6, an elevating device 7, an elevating motor 8, an opening and closing A device 9 and a ranging sensor 11 are provided.

As for the drive wheels 3, for example, a pair of drive wheels 3 are arranged at the center of the main body 2 in the y direction. The drive wheels 3 are variable in their traveling direction. A drive motor 4 drives the drive wheels 3 . For example, as shown in FIG. 1, the drive motors 4 are installed individually for each of the pair of drive wheels 3 . Incidentally, one drive wheel 3 and one drive motor 4 may be provided.

The pair of forks 6 are long members extending from the main body 2 in the positive x direction (rear side), which is an example of a predetermined direction. Each of the pair of forks 6 is arranged in parallel with a predetermined interval. A pair of forks 6 are provided behind the driving wheels 3 . A pair of forks 6 are for lifting a pallet 31 as an object to be transported.

A pair of driven wheels 5 are provided at respective ends of the pair of forks 6 . That is, a pair of driven wheels 5 are also provided behind the driving wheels 3 . The driven wheel 5 has a rotation axis along the y-axis direction.

The lifting device 7 lifts and lowers the pair of forks 6 along the z direction. The lifting motor 8 drives the lifting device 7 . For the lifting device 7, for example, a mechanism is conceivable in which a ball screw is rotated by a lifting motor 8 and the lifting device 7 fixed by fastening with a nut of the ball screw is moved up and down. It is not limited to this.

The distance measuring sensor 11 is an example of a sensor such as a depth camera, range sensor, 3D-LiDAR, etc., which is provided in the main body 2 and capable of detecting the position of the object to be transported. This distance measuring sensor 11 is installed on the fork 6 and may be movable along with the fork 6 in the y and z directions. The distance measuring sensor 11 is provided on the fork 6 and its height is variable in synchronism with the fork 6 . Moreover, the distance measuring sensor 11 may be installed in multiple numbers. For example, at least one may be installed on the right side (right side) of the body 2 and at least one may be installed on the left side (left side) of the body 2, or at least one may be installed in the center of the body 2 in the y direction. There is also Further, if the distance measuring sensor 11 has a detection position of the object to be transported within the recognition (detection) range, the position in each of the x, y, and z directions does not matter. Further, the transporting device 1 recognizes the length of the object to be transported in the y direction (width direction) by the distance measuring sensor 11, and changes the interval between the pair of forks 6 by the opening/closing device 9 according to the length. do. At least one of the plurality of distance measuring sensors 11 is preferably a sensor that detects obstacles, and the sensor preferably detects obstacles in the direction in which the pair of forks 6 extend. .

The driven wheel 5 has its rotating shaft attached to the forks 6 via a link mechanism 21 so that the relative position of the driven wheel 5 with respect to the pair of forks 6 lifted and lowered by the lifting device 7 can be changed. The link mechanism 21 is installed inside the main body 2 and the fork 6 and operates to change the relative height position between the built-in fork 6 and the driven wheel 5 attached to the fork 6 . The operation of the link mechanism 21 (see FIG. 3) allows the driven wheel 5 to be constantly grounded on the ground regardless of whether the fork 6 is raised or lowered. That is, the link mechanism 21 is an example of a moving part that maintains the installation of the driven wheels 5 by changing the relative distance between the driven wheels 5 and the forks 6 according to the elevation of the forks 6 by the lifting device 7 .

As shown in FIG. 3 , the link mechanism 21 has four link members 22 , 23 , 24 and 25 . The link member 22 has one end 22A connected to the main body 2 and the other end connected to the link member 23 . The link member 23 has one end connected to the link member 22 and the other end connected to the fork 6 and the link member 24 . The link member 24 has one end connected to the link member 23 and the other end connected to the link member 25 . The link member 25 has one end connected to the link member 24 and the fork 6 and the other end connected to the driven wheel 5 . When the fork 6 is lifted by the lifting device 7, the link member 23 and the link member 25 are rotated around the connection portions 26 and 27 with the fork 6, and the pair of forks 6 and the pair of driven wheels 5 are moved relative to each other. change position. Since one end 22A of the link member 22 is connected to the main body 2, it remains at the same height regardless of whether the fork 6 is raised or lowered. The height positions of the connecting portions 26 and 27 are changed according to the elevation of the fork 6 .

The transport device 1 also includes an opening/closing device 9 and an opening/closing motor 10 . The opening/closing device 9 makes the interval between the pair of forks 6 (and the driven wheels 5 provided on the forks 6) variable. The opening/closing motor 10 drives the opening/closing device 9 . The opening and closing device 9 shown in FIG. 1 has a fork 6 holding a pair of driven wheels 5 or a lifting device 7 for lifting the fork 6 holding the pair of driven wheels 5, and a structural member provided with a rack gear is attached. A mechanism that realizes opening and closing by rotating a gear meshed with a rack gear by an opening and closing motor 10 is conceivable. The form is not limited as long as it is a mechanism capable of

In the present embodiment, the carrying device 1 moves forward with the main body 2 forward, that is, in the negative x direction, and moves forward with the pair of forks 6 forward, that is, in the positive x direction. to move backward. That is, the main body 2 side of the carrying device 1 is the front side, and the pair of forks 6 side is the rear side.

In addition, the transportation device 1 preferably has an autonomous traveling function such as an AGV (Automatic Guided Vehicle) that can autonomously travel without an operation input from an operator. In addition, the autonomous traveling function and the automatic connection control function with the object to be transported enable the transporting device 1 to automatically transport the pallet 31 and the cart 41 without the help of the operator. can improve the convenience and versatility of The automatic connection control function and the autonomous travel function described above are performed by a control device such as a computer installed inside the main body 2 of the transport device 1 . The control device may be installed outside the transporting device 1 and may be connected to the transporting device 1 by wire or wirelessly so as to be communicable.

An object to be transported by the transporting apparatus 1 according to the present embodiment will be described with reference to FIGS. 4 and 5. FIG. FIG. 4 is a perspective view showing an example of the form of a pallet, which is an example of an object to be transported by the transporting device according to the present embodiment. The pallet 31 is composed of a deck board 32 on which cargo is placed, an under deck 33 grounded on the floor, and a girder 34 connecting the deck board 32 and the under deck 33. A side surface of the pallet 31 functions as an insertion opening 35 into which the fork 6 can be inserted through the gaps between the girders 34 . Depending on the type of pallet 31, the under deck 33 may not exist, or the deck board 32 and the under deck 33 may be hollowed out. Materials of the pallet 31 include wood, plastic, cardboard, and the like.

FIG. 5 is a perspective view of a cage truck as an example of a truck that is an example of an object to be transported by the transporter according to the present embodiment. The carriage 41 includes a base plate 42 parallel to the floor, a base plate frame 43 holding the base plate 42 , and wheels 44 provided on the base plate frame 43 . The truck 41 may have a fence 45 provided on the base plate 42 depending on the type (for example, in the case of a car truck). A trolley 41, which is an object to be transported in the present embodiment, is a wheeled trolley commonly used in distribution warehouses and factories. The number of wheels and whether they are swivel wheels or fixed wheels does not matter. Examples of the truck 41 include a cage truck, a six-wheeled cart, a dolly, and the like. For example, in the case of a cage bogie, a four-wheel configuration is common, but two of the four wheels may be rotatable wheels and the remaining two wheels may be fixed wheels, or all four wheels may be rotatable wheels. Also, a six-wheeled bogie generally has six wheels, with two central wheels being fixed wheels and the remaining four wheels being rotatable wheels. As described above, the form of the wheel configuration differs depending on the type of truck, but the transportation device 1 according to the present embodiment can transport regardless of the form of the wheel configuration of the truck 41 . In some cases, such as a dolly, the base plate 42 and the base plate frame 43 are the same member.

6A and 6B are plan views when the transport device according to the present embodiment recognizes the position of a pallet, which is an example of an object to be transported. The transportation device 1 is provided with means for acquiring information on the object to be transported by the transportation device 1 from an external system such as a WMS (Warehouse Management System) having information on the object to be transported. Therefore, it is also possible to grasp information as to whether the object to be transported is on the left or right side of the travel path. For example, as shown in FIG. 6A, when the transport device 1 has a pallet 31 on the right side of the main body 2, the distance measuring sensor 11 attached to the right side of the main body 2 recognizes the position of the object to be transported. As shown in FIG. 6B, when the pallet 31 is located on the left side of the body 2, the transportation device 1 recognizes the position of the object to be transported by the distance measuring sensor 11 attached to the left side of the body 2. FIG. When the object to be transported is the pallet 31, the transportation device 1 detects the three girders 34 provided in front of the pallet 31 by the distance measuring sensor 11, and detects the center of the central girders 34 among the three. By calculating the position, the center of the pallet 31 is recognized and the position of the pallet 31 is specified. Further, the transport device 1 detects the three girders 34 provided in front of the pallet 31, and calculates the width of the center girder 34 among the three girders 34, thereby determining the inner width of the insertion port of the pallet 31. , and the inner width of the left and right (both ends) girders 34 is recognized as the outer width of the insertion port of the pallet 31 .

FIG. 7 is a flowchart showing an example of the flow of the pallet position detection operation by the transport device according to the present embodiment. Specifically, in FIG. 7, after the transportation device 1 acquires the approximate position information of the pallet 31 as an example of the object to be transported, the range sensor 11 detects the girders 34 of the pallet 31, and the pallet 31 4 is a flowchart of operations for recognizing the center;

First, the transportation device 1 receives information on the next object to be transported (step S201). The information received here includes information such as the type of object to be transported such as the pallet 31 and the cart 41, the positional coordinates of the object to be transported, and presence information indicating whether the object to be transported is on the left or right side of the travel path. be. Next, the transport device 1 moves and approaches the object to be transported based on the position coordinates of the object to be transported (step S202). If the object to be transported is not approaching (step S202: No), the transporting device 1 continues to determine whether the object to be transported is approaching. On the other hand, when approaching the object to be transported (step S202: Yes), based on the existence information, the transport device 1 uses the distance measuring sensor 11 in the direction indicated by the existence information to measure the surroundings of the object to be transported. Data is acquired (step S203). That is, the transportation device 1 can recognize in advance whether the object to be transported is in the left direction or the right direction of the travel path, and can detect the direction in which the object to be transported exists on the travel path (the recognized direction). A range sensor 11 is selected to acquire data around the object to be transported.

Next, the transport device 1 detects the three girders 34 in front of the pallet 31 based on the data around the object to be transported (step S204). Further, the transporting device 1 determines whether or not three girders 34 have been detected (step S205). If the three digits 34 are normally detected (step S205: Yes), the process proceeds to step S206. If the three digits 34 are not detected normally and determined to be abnormal (step S205: No), the process proceeds to step S208. The determination here is whether or not the three digits 34 have been determined normally. If the inner/outer width can be determined, it may be determined that the digit 34 has been successfully detected.

Next, the conveying device 1 sets the girder 34 closest to the position coordinates of the object to be transported as the center girder 34 , and inserts the center girder 34 from the center position of the center girder 34 to the center position of the pallet 31 and the width of the center girder 34 . The inner width of the hour is determined (step S206). Further, the transport device 1 determines the outer width at the time of insertion from the positions and widths of the left and right girders 34 (step S207). Furthermore, when the girder 34 is not detected normally, the transporting device 1 notifies the detection error of the position of the girder 34 by turning on an alarm light, issuing an alarm sound, etc. (e.g., notifying a host system such as a server ) and the like are executed (step S208).

8A and 8B are plan views when the transport device according to the present embodiment recognizes the position of the carriage of the object to be transported. Even if the object to be transported is the trolley 41, the transporting device 1 has means for acquiring information on the object to be transported by the transporting device 1 from an external system such as a WMS that has information on the object to be transported. Since it is provided, it is also possible to grasp information as to whether the object to be transported is on the left or right of the traveling path of the transporting device 1 .

For example, as shown in FIG. 8A, when the carriage 41 is on the right side of the body 2, the transportation device 1 recognizes the position of the object to be transported by the distance sensor 11 attached to the right side of the body 2. FIG. Further, as shown in FIG. 8B, when the carriage 41 is on the left side of the main body 2, the transporting device 1 recognizes the position of the object to be transported by the distance measuring sensor 11 attached to the left side of the main body 2. FIG. The transportation device 1 detects the two wheels 44 provided on the front of the carriage 41 by the distance measuring sensor 11, and calculates the position of the midpoint of the line connecting the center points of the two wheels 44. Thus, the center of the carriage 41 is recognized and the position of the object to be transported is specified. In addition, the transport device 1 detects two wheels 44 provided on the front of the truck 41, and calculates the length of the inner width of the truck 41 between the center points of the two wheels 44. Specify (recognize) the insertion width of the .

FIG. 9 is a flow chart showing an example of the flow of the carriage position detection operation by the carrier device according to the present embodiment. Specifically, in FIG. 9, after the transportation device 1 acquires approximate position information of a truck 41 as an example of an object to be transported, the distance measurement sensor 11 detects wheels 444 of the truck 41, 4 is a flowchart of operations for recognizing the center; In the following description, steps S401 to S403 shown in FIG. 9 are the same as steps S201 to S203 shown in FIG. 7, so description thereof will be omitted.

The transportation device 1 detects two wheels in front of the truck 41 (car) based on the data around the object to be transported (step S404). Here, if three or more wheels are detected, the two wheels closest to the position coordinates received in step S401 are detected as the wheels of the cart 41 (car car) that is the object to be transported. Next, the transporter 1 determines whether two wheels have been detected (step S405). If it is determined that the two wheels have been detected normally (step S405: Yes), the process proceeds to step S406. If the two wheels are not detected normally and determined to be abnormal (step S405: No), the process proceeds to step S407.

Next, the transport device 1 calculates (determines) the center position of the carriage 41 from the median value of the two wheels and the inner width at the time of insertion from the interval between the two wheels (step S406). In addition, when the two wheels are not detected and determined to be abnormal, the transporting device 1 issues a notification such as turning on an alarm light and issuing an alarm sound (for example, notifying a host system such as a server). Error processing is executed (step S407).

10A to 10D are for explaining an example of a trajectory when the transportation device according to the present embodiment recognizes the position of the object to be transported and then approaches the object to be transported to a position where the fork can be inserted. It is a diagram. In the present embodiment, the transporting device 1 retreats in an arc to approach the object to be transported to a position where the pair of forks 6 can be inserted. A point A is the center of the pair of driven wheels 5 when the transportation device 1 recognizes the position of the object to be transported (for example, the pallet 31). After the transport device 1 recognizes the position of the object to be transported, as shown in FIG. Calculate the trajectory data of the arc approach so that the center of the direction is the same.

Thereafter, as shown in FIG. 10A, the transporter 1 reaches the starting point of the arc by moving the center of the pair of driven wheels 5 from point A to point B. FIG. At this time, the transport device 1 may change the width of the pair of forks 6 by the opening/closing device 9 to a width suitable for inserting the object to be transported. Note that the timing of changing the width of the pair of forks 6 is not limited as long as the timing is between when the transportation device 1 recognizes the position and width of the object to be transported and when it is connected to the object to be transported. After the center of the pair of driven wheels 5 is moved to point B, which is the starting point of the arc, the center of the pair of forks 6 in the width direction is moved to the calculated arc approach as shown in FIGS. 10B to 10D. , the pair of forks 6 are retracted so as to face the object to be transported, and the center of the pair of driven wheels 5 is positioned at point D via point C.

FIG. 11 is a diagram showing an obstacle detection range of a range sensor included in the transportation device according to the present embodiment. The distance measuring sensor 11 included in the transportation device 1 according to the present embodiment can also be used as means for detecting obstacles existing around the transportation device 1 . When objects to be transported are loaded on the pair of forks 6, it is difficult to detect obstacles behind the main body 2. - 特許庁However, by installing the distance measuring sensor 11 so that the detection surface of the distance measuring sensor 11 is located below the fork 6, the obstacle behind the main body 2 can be effectively detected regardless of whether or not the object to be transported is loaded. can be When trying to detect an obstacle from below the fork 6, there is a range where the pair of driven wheels 5 becomes a blind spot. Therefore, by installing a plurality of distance measuring sensors 11 , it is possible to eliminate the blind spots created by one distance measuring sensor 11 by using the other distance measuring sensors 11 .

As described above, according to the transporting apparatus 1 according to the present embodiment, by providing a plurality of distance measuring sensors 11 for recognizing the position of an object to be transported, mainly the horizontal detection area of the distance measuring sensors 11 can be widened. Since the position of the object to be transported can be recognized even when the object to be transported is placed in the lateral direction of the AGV, the AGV can be approached to a position where it can be correctly connected to the object to be transported even in a narrow passage. becomes possible.

Reference Signs List 1 transportation device 2 main body 3 driving wheel 4 driving motor 5 driven wheel 6 fork 7 lifting device 8 lifting motor 9 opening and closing device 11 range sensor 21 link mechanism 22, 23, 24, 25 link member 26, 27 connecting portion 31 pallet 32 deck Board 33 Underdeck 34 Girder 35 Insertion port 41 Truck 42 Base plate 43 Base plate frame 44 Wheel 45 Fence

Japanese Patent No. 4427360

Claims (12)

a body having drive wheels;
a pair of forks extending in a predetermined direction from the body for lifting an object to be transported;
a driven wheel provided at each tip of the pair of forks;
A lifting device for lifting and lowering the pair of forks;
a moving unit that changes the relative distance between the driven wheel and the fork according to the lifting and lowering of the fork by the lifting device and maintains the ground contact of the driven wheel;
a plurality of sensors provided on the main body and capable of detecting the position of an object to be transported;
A transporting device comprising a 2. The carrying device according to claim 1, comprising an opening/closing device for opening and closing said pair of forks. at least one of the plurality of sensors is provided on the right side of the main body;
3. The carrying device according to claim 1 or 2, wherein at least one of said plurality of sensors is provided on the left side of said main body. 4. The carrying device according to any one of claims 1 to 3, wherein at least one of said plurality of sensors is provided on said fork and is variable in height in synchronism with said fork. 5. The method according to any one of claims 1 to 4, having a function of recognizing in advance whether the object to be transported is in the left direction or the right direction of the traveling path, and selecting the sensor capable of detecting in the recognized direction. A transport device as described. 6. The sensor according to any one of claims 1 to 5, wherein when the object to be transported is a pallet, the sensor detects three girders on the front of the pallet and recognizes the center position of the girders in the center as the center of the pallet. 2. The transport device according to . When the object to be transported is a truck, the sensor detects two wheels on the front of the truck and recognizes the midpoint of a line connecting the center points of the two wheels as the center of the truck. Item 6. The transport device according to any one of items 1 to 5. When the object to be transported is the pallet, the sensor detects three girders on the front of the pallet, recognizes the width of the central girder as the inner width of the pallet insertion opening, and recognizes the width of the girders at both ends. 7. A carrier according to claim 6, wherein the inner width is recognized as the outer width of the pallet insertion opening. 8. The sensor according to claim 7, wherein when the object to be transported is the truck, the sensor detects two wheels of the truck and recognizes a distance between center points of the two wheels as an insertion width of the truck. transporter. 10. The carrying device according to any one of claims 1 to 9, wherein at least one of said plurality of sensors is a sensor for detecting obstacles. 10. The carrying device according to any one of claims 1 to 9, wherein at least one of said plurality of sensors detects an obstacle in the direction in which said pair of forks extend. 12. The carrier according to any one of claims 1 to 11, having an autonomous travel function.

Images