JP2022147813A - Transport device, and transport method - Google Patents

Abstract

To provide a transport device capable of approaching a position correctly connectable with respect to an object to be transported even in a narrow passage, and to provide a transport method.SOLUTION: A transport device includes: a body having a driving wheel; a pair of forks extending in a predetermined position from the body, and for lifting an object to be transported; driven wheels provided at tips of the pair of forks respectively; a lifting device for moving up/down the pair of forks; a plurality of sensors provided at the body part, and capable of detecting the position of the object to be transported; and an arithmetic device for generating locus data of a circular arc approach for moving to a position in which the pair of forks can be inserted, based on the detection result of the object to be transported by the sensor. The arithmetic device determines an end point of the locus data, a starting point of the circular arc locus data movable to the end point, and a posture of the body on the starting point of the locus data.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a transporting device and a transporting method.

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 carts, such as basket carts and six-wheeled carts. 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 in which a connecting portion (for example, fork) with the object to be transported faces a certain direction. 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. Even if a sensor with a detection area of 180 degrees or more is used and detection in the lateral direction is possible, it is necessary to devise an arrangement in which a single sensor can detect 180 degrees 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 transporting device and a transporting method that enable an object to be transported to be approached to a position where it can be correctly connected even in a narrow passage. do.

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 plurality of sensors provided on the main body capable of detecting the position of an object to be transported; an arithmetic device for generating trajectory data of an arc approach that moves to a position where the pair of forks can be inserted, based on the detection result of , wherein the arithmetic device includes an end point of the trajectory data and an end point at the end point A starting point of trajectory data of the movable arc and a posture of the main body on the starting point of the trajectory data are determined.

ADVANTAGE OF THE INVENTION According to this invention, it is effective in making it possible to approach the position which can connect correctly with respect to a conveying target object even in a narrow passage.

FIG. 1 is a perspective view of a carrier according to this embodiment. FIG. 2A is a side view of the transport device according to this embodiment. FIG. 2B is a diagram for explaining an example of a circular arc approach to an object to be transported in the transporting device according to the present embodiment. FIG. 2C is a diagram for explaining an example of a circular arc approach to an object to be transported in the transporting device according to the present embodiment. FIG. 2D is a diagram for explaining an example of a circular arc approach to an object to be transported in the transporting device according to the present embodiment. FIG. 2E is a diagram for explaining an example of a circular arc approach to an object to be transported in the transporting device according to the present embodiment. FIG. 2F is a diagram for explaining an example of a circular arc approach to an object to be transported in the transporting device according to the present embodiment. FIG. 2G is a diagram for explaining an example of a circular arc approach to an object to be transported in the transporting device according to the present embodiment. FIG. 2H is a diagram for explaining an example of a circular arc approach to an object to be transported in the transporting device according to the present embodiment. FIG. 2I is a diagram for explaining an example of a circular arc approach to an object to be transported in the transporting apparatus according to the present embodiment. FIG. 3 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. 4 is a perspective view of a car carriage as an example of a carriage that is an example of an object to be transported by the transport device according to the present embodiment. FIG. 5 is a plan view for explaining the process of recognizing the position of a pallet, which is an example of an object to be transported, by the transporting apparatus according to the present embodiment. FIG. 6 is a plan view for explaining a process of recognizing the position of a truck, which is an example of a transport object, by the transport device according to the present embodiment. FIG. 7A 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. 7B 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. 7C 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. 7D 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.

Embodiments of a transporting device and a transporting method 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 transporting device 1 according to the present embodiment can hold a pallet 31 (see FIG. 4), a carriage 41 (see FIG. 5, etc.) such as a car carriage, a six-wheeled trolley, or a dolly. By autonomously moving in this state, the pallet 31 and the cart 41 as the object to be transported (object to be transported) can be transported to desired positions. 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 transporting device 1 according to this embodiment will be described with reference to FIGS. 1 and 2A. FIG. 1 is a perspective view of a carrier according to this embodiment. FIG. 2A is a side view 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 , an opening/closing motor 10 and a distance measuring sensor 11 are provided. The transportation device 1 also includes an arithmetic device 12 that generates trajectory data of an arc approach that moves to a position where the pair of forks 6 can be inserted, based on the recognition (detection) result of the object to be transported by the distance measuring sensor 11 . Prepare.

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 . It should be noted that 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. Moreover, the distance measuring sensor 11 may be installed in multiple numbers. For example, at least one may be installed on the right side of the main body 2 and at least one may be installed on the left side of the main body 2, or at least one may be installed on the center of the main body 2 in the y direction. Further, if the distance measuring sensor 11 has a detection position of an object to be transported within its recognition range, it does not matter where it is in the x, y, and z directions. 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.

The arithmetic unit 12 is an example of an arithmetic unit that generates trajectory data of an arc approach that moves to a position where the pair of forks 6 can be inserted, based on the recognition (detection) result of the object to be transported by the distance measuring sensor 11 . . When generating trajectory data for the circular arc approach, the computing device 12 determines the end point of the trajectory data for the circular approach so that the center of the pair of forks 6 coincides with the center of the object to be transported, and reaches the end point. Determine the starting point of the trajectory data for the possible arc approach. The computing device 12 also determines the attitude of the transport device 1 on the starting point of the trajectory data. By providing a plurality of distance measuring sensors 11 for recognizing the position of the object to be transported, the detection area of the distance measuring sensor 11 mainly in the lateral direction is widened, and even when the object to be transported is placed in the lateral direction of the transport device 1, It becomes possible to recognize the position of the object to be transported. And since it is possible to make an arc approach in which the center of the pair of forks 6 coincides with the center of the object to be transported, it is possible to approach the object to a position where it can be correctly connected even in a narrow passage. becomes.

When the lateral direction of the transporting device 1 cannot be recognized by the distance measuring sensor 11 for recognizing the position of the object to be transported, the transporting device 1 makes an arc approach to the object to be transported, and then moves a pair of forks toward the object to be transported. It is necessary to insert the fork 6 into the object to be transported while proceeding in the direction of inserting the fork 6. If the passage is narrow, the distance that the conveying device 1 advances in the direction in which the forks 6 are inserted into the object to be conveyed after the arc approach is shortened, making it difficult to align the forks 6 with the object to be conveyed. .

Therefore, the transportation device 1 according to the present embodiment is provided with a plurality of distance measurement sensors 11 for recognizing the position of the object to be transported, thereby widening the detection area of the distance measurement sensors 11 mainly in the horizontal direction and performing the arc approach. Make it possible to recognize the position of the object to be transported before moving it. When the horizontal direction can be recognized, the position of the object to be transported can be recognized before the arc approach. That is, by specifying the position where the pair of forks 6 can be inserted into the object to be transported and calculating the position to which the circular approach can be made, a pair of It becomes unnecessary to adjust the position while proceeding in the direction of inserting the fork 6.例文帳に追加Therefore, the pair of forks 6 can be correctly inserted into the object to be transported as long as the passage width allows for the arc approach.

2B to 2I are diagrams for explaining an example of a circular arc approach to an object to be transported in the transporting apparatus according to the present embodiment. As shown in FIG. 2B, after the conveying device 1 has approached the object to be conveyed in an arc such as a narrow passage, the distance between the conveying device 1 and the object to be conveyed is short, and the pair of the conveying objects is aligned while being aligned with the object to be conveyed. It may be difficult to insert the fork 6 of the In this case, as shown in FIGS. 2C and 2D, it is necessary to approach the transporting device 1 to the object to be transported so that the pair of forks 6 can be inserted while approaching the object to be transported. .

However, when the transportation device 1 makes an arc approach as shown in FIG. 2E, the distance between the object to be transported and the pair of forks 6 is short, and the positional relationship is such that the pair of forks 6 can be inserted while approaching the object to be transported. It can be difficult to move around. In this case, as shown in FIGS. 2F and 2G, the transporting device 1 moves away from the object to be transported once, and then moves to a position where the pair of forks 6 can be inserted into the object to be transported. It is necessary to have a relationship, and an extra passage width is required for the distance.

Therefore, in the present embodiment, as described above, the transporting device 1 specifies the position where the pair of forks 6 can be inserted into the object to be transported, and determines the position where the circular approach can be made toward that position. By calculating, it becomes unnecessary to align the position while moving in the direction of inserting the pair of forks 6 into the object to be transported after the arc approach. Therefore, the pair of forks 6 can be correctly inserted into the object to be transported as long as the passage width allows for the arc approach.

Also, as shown in FIG. 2H, when recognizing that the object to be transported is placed obliquely with respect to the transporting device 1, the transporting device 1 moves toward the center of the object to be transported as shown in FIG. 2I. , the attitude at the position of the starting point is determined so that the arc approach can be made so that the centers of the pair of forks 6 coincide. As a result, the transportation device 1 can approach the object to be transported by drawing the same arc radius regardless of how the object to be transported is placed, by matching the attitude of the starting point.

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/closing device 9 shown in FIG. 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, but the interval between the pair of driven wheels 5 or the interval between the forks 6 that hold the pair of driven wheels 5 can be made variable. The form is not limited as long as it is a mechanism that can do so.

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. The movement to is regarded as backward movement. 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. 1 convenience and versatility can be improved. 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 example of an object to be transported by the transporting device according to the present embodiment will be described with reference to FIG. FIG. 3 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. The material of the pallet 31 includes wood, plastic, cardboard, and the like.

FIG. 4 is a perspective view of a car carriage as an example of a carriage that is an example of an object to be transported by the transport device 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.

FIG. 5 is a plan view for explaining the process of recognizing the position of a pallet, which is an example of an object to be transported, by the transporting apparatus according to the present embodiment. The conveying device 1 detects the three girders 34 provided in front of the pallet 31 by the distance measuring sensor 11, and calculates the center position of the central girders 34 among the three girders 34, thereby determining the position of the pallet 31. The center 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 central girders 34 among the three girders 34, thereby determining the inner width of the pallet 31. Also, the outer width of the pallet 31 is specified from the left and right girders 34 .

FIG. 6 is a plan view for explaining a process of recognizing the position of a truck, which is an example of a transport object, by the transport device according to the present embodiment. 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 truck 41 is recognized and the position of the truck 41 is specified. Further, the transport device 1 identifies the width of the truck 41 by detecting two wheels 44 provided in front of the truck 41 and calculating the length of the inner width of the two wheels 44 .

7A to 7D 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. 7B, the transport device 1 aligns the center of the pair of forks 6 in the width direction (point D shown in FIG. 7D) with the front width of the object to be transported. Calculate the trajectory data of the arc approach so that the center of the direction is the same.

After that, as shown in FIG. 7A, the center of the pair of driven wheels 5 moves from point A to point B, and the transporter 1 reaches the starting point of the arc approach. 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 has moved to the starting point of the arc approach, the transportation device 1 moves the center of the pair of forks 6 in the width direction to draw the calculated trajectory of the arc approach, as shown in FIGS. 7B to 7D. Then, 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 through point C.

As described above, according to the transporting apparatus 1 of the present embodiment, by providing a plurality of distance measuring sensors 11 for recognizing the position of an object to be transported, the detection area of the distance measuring sensors 11 mainly in the horizontal direction is 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 transporting device 1, it is possible to approach the position where the object to be transported can be correctly connected even in a narrow passage. Become.

1 transporting 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 10 opening and closing motor 11 distance measuring sensor 12 computing device 31 pallet 32 deck board 33 under deck 34 digit 35 insertion port 41 Carriage 42 Base plate 43 Base plate frame 44 Wheel

Japanese Patent No. 6469506

Claims (2)

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 plurality of sensors provided on the main body and capable of detecting the position of an object to be transported;
an arithmetic device that generates trajectory data of an arc approach that moves to a position where the pair of forks can be inserted based on the detection result of the object to be transported by the sensor;
The transportation device, wherein the computing device determines an end point of the trajectory data, a start point of the trajectory data that is movable to the end point, and an attitude of the main body on the start point of the trajectory data. A main body having drive wheels, a pair of forks extending in a predetermined direction from the main body for lifting an object to be transported, driven wheels provided at respective ends of the pair of forks, and lifting and lowering the pair of forks. and a plurality of sensors provided on the main body and capable of detecting the position of the object to be transported.
a step of generating trajectory data of an arc approach moving to a position where the pair of forks can be inserted based on the detection result of the object to be transported by the sensor;
determining an end point of the trajectory data, a start point of the trajectory data movable to the end point, and a posture of the main body on the start point of the trajectory data;
transportation methods, including;

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