JP7597693B2 - Transport System - Google Patents

Description

The present invention relates to a transport system.

Paragraph 0009 of Patent Document 1 describes how, in response to an order, an inventory holder in which the inventory item is stored is moved to a workstation or other area by an unmanned robotic drive device.

Paragraphs 0012 and 0039 of Patent Document 1 describe transporting inventory items from a first inventory area or facility to a second inventory area or facility using an inter-area or inter-facility cargo transport device (such as a truck or other road-based vehicle).

Paragraph 0033 of the above-mentioned patent document 1 describes that the inventory holder includes a base portion and a storage portion, and that the storage portion can be separated from the base portion and lifted by a forklift.

Paragraphs 0044 and 0051 of the above-mentioned patent document 1 state that a human operator uses a forklift or other user-operated lift to remove the inventory holder from the load transport device and place the inventory holder on a loading dock adjacent to the load transport device.

Paragraphs 0053 and 0054 of the above-mentioned Patent Document 1 state that when the unmanned robot driving device is used to load an inventory holder onto the bed or into the cargo area of the cargo transport device, the reference marks on the mat are sensed by a positioning sensor.

Patent No. 6302075 (Special Publication No. 2016-533999)

The above-mentioned Patent Document 1 does not state that the unmanned robot drive device can be fine-tuned in the forward/backward/left/right directions and at the angle when in the stopped position.

Therefore, in the above-mentioned Patent Document 1, for example, if the inventory holder mounted on the stopped unmanned robot driving device is misaligned with respect to the forklift, the operator of the forklift must visually check the misalignment while operating the forklift to make detailed corrections.

As a result, there are concerns that this will be inefficient, as it will require time-consuming work to transfer the inventory holders mounted on the stopped unmanned robot driving device to another location using a forklift.

In light of these circumstances, the present invention aims to provide a transport system that, when an autonomous transport robot has reached a waiting location for an autonomous forklift, can accurately and quickly place pallets stacked on a platform on the autonomous transport robot in a position where they can be lifted by the autonomous forklift.

The transport system according to the present invention includes a plurality of pallets on which cargo is stored, a stand on which the plurality of pallets are stacked vertically, an autonomous transport robot that crawls into the space under the stand and moves while lifting up the stand, an autonomous forklift that is on standby near the destination to which the pallets are to be transported and that lifts up and transports the necessary pallet from the autonomous transport robot when it reaches the destination, a measuring device that measures the position of the pallet on the autonomous transport robot when it reaches the destination, and a management device that executes the following processes, and the bottom of the pallet is provided with a fork pocket into which the forks of the autonomous forklift are inserted, and the autonomous The traveling transport robot is equipped with a lifting table for raising and lowering the platform, and drive wheels for generating drive force for moving forward, backward, sideways, and rotating. The management device is characterized in that, when the autonomous traveling transport robot equipped with a platform on which the multiple pallets are stacked reaches the destination, it executes a process of having the measuring device measure the positions of the pallets and the forks on the autonomous traveling transport robot, and a process of determining whether or not there is a misalignment of the fork pocket relative to the fork based on the output of the measuring device, and, if it is determined that there is a misalignment, having the autonomous traveling transport robot correct the misalignment.

In this configuration, if it is determined based on the output of the measuring device that the fork pockets of the pallet are misaligned with respect to the forks of the self-driving forklift on the autonomous transport robot stopped at the destination, the autonomous transport robot corrects the misalignment.

This makes it possible to quickly and accurately insert the forks of the autonomous forklift into the fork pockets of any pallet on a platform mounted on the autonomous transport robot that has stopped at the destination.

This makes it possible to quickly perform the tasks from stopping the autonomous transport robot at the destination to lifting any pallet on the autonomous transport robot using the automatically operated forklift.

The self-driving forklift can be configured to lift and transport the required number of pallets from the platform of the autonomous transport robot that has reached the destination.

The autonomous transport robot may also be configured to include a front driven wheel installed at the front of the vehicle body, a rear driven wheel installed at the rear of the vehicle body, a left drive wheel installed on the left side in the middle of the vehicle body in the fore-and-aft direction, a right drive wheel installed on the right side in the middle of the vehicle body in the fore-and-aft direction, a motor that drives the left drive wheel and the right drive wheel individually, an encoder that individually detects the direction of rotation, angle of rotation, and number of rotations of the left drive wheel and the right drive wheel, and a control device that controls the left drive wheel and the right drive wheel based on destination information, information on the pallet to be lifted, and the position deviation information input from the management device.

The present invention provides a transport system that allows an autonomous transport robot to reach a waiting area for an autonomous forklift and then accurately and quickly place pallets stacked on a platform on the autonomous transport robot in a position where they can be lifted by the autonomous forklift.

1 is a side view showing an embodiment of a transport system according to the present invention. FIG. 2 is a plan view showing the configuration and shape of the autonomous traveling transport robot. FIG. 2 is a plan view of an autonomous transport robot equipped with a pallet and a stand. FIG. 2 is a block diagram showing a schematic configuration of a transport system. FIG. 1 is a block diagram showing a schematic configuration of an autonomous transport robot. FIG. 1 is a side view showing the state when a pallet on an autonomous transport robot that has reached its destination is lifted and removed by an autonomous forklift. FIG. 7 is a side view showing the state when the pallet lifted by the autonomous forklift from the state shown in FIG. 6 is brought close to a stand on another autonomous traveling transport robot. FIG. 8 is a side view showing the state when the pallet lifted by the autonomous forklift from the state shown in FIG. 7 is placed on a stand on another autonomous traveling and transport robot.

The best mode for carrying out the present invention will now be described in detail with reference to the accompanying drawings.

Figures 1 to 8 show one embodiment of the present invention. In the figures, 1 is a travel path, 2 is an autonomous transport robot (AMR: abbreviation for Autonomous Mobile Robot), 3A to 3D are pallets, 4 is a stand, and 5 is an automatically operated forklift (AGF: abbreviation for Automated Guided Forklift).

The travel path 1 is a track for the autonomous transport robot 2 to travel on, and may be, for example, the floor of a warehouse or factory premises, or an outdoor road on private land.

Although not shown, guide markers (QR codes, etc.) are placed in a grid pattern on this moving path 1 to guide the moving path of the autonomous moving transport robot 2.

The autonomous transport robot 2, which will be described in detail later, is an unmanned transport vehicle that, as is well known, can transport pallets 3A-3D containing cargo (not shown) to a destination (a waiting location for the autonomous forklift 5) by autonomously traveling according to a predetermined program run by a computer without the need for tracks, guides, or human operation.

The cargo is items other than people, and is of a size and shape that can be stored within pallets 3A to 3D.

Pallets 3A to 3D are constructed by assembling a bottom wall and side walls (numbers omitted) between four vertical supports (numbers omitted), and are configured to store cargo (not shown) through an opening at the top in a manner that will not allow it to fall out.

These pallets 3A to 3D have legs 31 protruding downward at the four corners of the bottom wall, and fork pockets 32 are provided at the lower part (bottom) of the bottom wall.

The fork pocket 32 is a space provided at the lower part (bottom) of the bottom wall by the presence of each leg 31 of the pallets 3A to 3D, and is set to a size that allows the forks 51 of the autonomous forklift 5 to be inserted.

Such pallets 3A to 3D are configured such that, when stacked vertically, the lower ends of each leg 31 are engaged with the upper ends of each of the supports, so that the pallets are positioned in a non-separable manner horizontally (in the X-axis and Y-axis directions of pallets 3A to 3D).

However, to make it easier to stack pallets 3A to 3D vertically, a small amount of clearance is provided in each of the locking portions in the lateral direction.

The stand 4 is configured with legs 42 extending downward from the four corners of a plate-like body 41 that is rectangular in plan view.

A lower marker (not shown) is attached to the center position on the underside of the body 41 of the platform 4, and serves as a guide for mounting the platform 4 on the lift table 22 of the autonomous mobile transport robot 2. On the other hand, an upper camera 7 (see FIG. 5) is provided at the center P position on the upper surface of the body 21 of the autonomous mobile transport robot 2 to recognize the lower marker.

When mounting the platform 4 on the autonomous mobile transport robot 2, the control device 28 of the autonomous mobile transport robot 2 causes the autonomous mobile transport robot 2 to slip under the platform 4 based on the detection output of the lower camera 6, and the control device 28 of the autonomous mobile transport robot 2 stops the autonomous mobile transport robot 2 at a position where it recognizes the lower marker (not shown) based on the detection output of the upper camera 7, and then lifts the lift table 22. This allows the platform 4 to be mounted on the lift table 22 in a well-balanced manner, that is, without tilting or shaking.

The autonomous forklift 5 is an unmanned device that lifts and transports the requested items from among the pallets 3A to 3D in accordance with input information from the management device 10, and is equipped with forks 51 that are inserted into the fork pockets 32 of the pallets 3A to 3D.

The fork 51 is designed to be raised and lowered along the support 52. The support 52 is installed on the base of the autonomous forklift 5 so that it can be displaced in the forward and backward directions.

The self-driving forklift 5 also has driven wheels (reference numbers omitted) on the front lower side of its chassis, and drive wheels (reference numbers omitted) on the rear lower side of the chassis, and is configured so that the drive wheels are steered by an automatic steering device (not shown).

Next, the autonomous transport robot 2 will be described in detail.

As shown in Figures 1 and 2, the autonomous transport robot 2 includes a vehicle body 21, a lift table 22, front driven wheels 23, rear driven wheels 24, a left driving wheel 25, a right driving wheel 26, LiDAR sensors 27a and 27b, a control device 28, and the like.

As shown in FIG. 2, the vehicle body 21 is generally rectangular in plan view with an arc shape at the front and rear.

A lower camera 6 (see FIG. 5) is installed at the center P position on the underside of the vehicle body 21. This lower camera 6 is provided to recognize the guide markers installed on the travel path 1.

As shown in Figures 2 and 3, the front-rear direction of the vehicle body 21 is the X axis, the left-right direction of the vehicle body 21 is the Y axis, and the swing angle (direction) from the center of the autonomous transport robot 2 (see P) is θ.

2, the lift table 22 is formed in a ring shape in a plan view, and is provided so as to be able to rise and fall on the vehicle body 21. The platform 4 is mounted on the lift table 22.

The front driven wheels 23 and rear driven wheels 24 each consist of a pair of wheels, one on the left and one on the right, and are supported in a state that allows them to rotate freely (forward and reverse).

The front driven wheels 23 are located at the front of the vehicle body 21, and the rear driven wheels 24 are located at the rear of the vehicle body 21.

The left drive wheel 25 is located on the left side of the vehicle body 21 in the middle of the fore-aft direction, and the right drive wheel 26 is located on the right side of the vehicle body 21 in the middle of the fore-aft direction.

The left drive wheel 25 and the right drive wheel 26 are each a single wheel, and are of a differential drive type that are independently driven by separate motors 25a, 26a (see Figure 5).

Encoders 25b, 26b are provided near the left driving wheel 25 and the right driving wheel 26 on the underside of the vehicle body 21.

These encoders 25b and 26b individually detect the direction of rotation, angle of rotation, and number of rotations of the left driving wheel 25 and the right driving wheel 26.

As is well known, the LiDAR sensors 27a and 27b use laser light to measure the shape and distance of objects at a distance, and are located midway between the front and rear of the vehicle body 21 in the left-right direction.

The detection outputs of the encoders 25b, 26b and the LiDAR sensors 27a, 27b are used to autonomously drive the autonomous transport robot 2 and to correct positional deviations of the pallets 3A to 3D at the destination.

The control device 28 is a computer that controls various operations of the autonomous transport robot 2, and is capable of communicating with, for example, a management device 10 located externally.

As shown in FIG. 4, the management device 10 is a computer that controls the operation of the autonomous transport robot 2 and the autonomous forklift 5.

This management device 10 executes at least the following processes: inputting information about the destination (waiting location of the autonomous forklift 5) to which the pallets 3A-3D containing cargo (inventory items) are to be transported, as well as the positional deviation information described below, to the control device 28 of the autonomous transport robot 2; inputting information about the pallets (3A-3D) to be lifted by the autonomous forklift 5 at the destination to the control device (not shown) of the autonomous forklift 5; and updating and storing the locations of the pallets 3A-3D one by one.

In addition, the management device 10 executes a process to have the measuring device 20 measure the positions of the fork pockets 32 of the pallets 3A to 3D on the autonomous transport robot 2 and the positions of the forks 51 of the autonomous forklift 5 when the autonomous transport robot 2 reaches the destination.

The measuring device 20 includes, for example, a surveillance camera and various measurement sensors, and outputs a measurement signal to the management device 10.

1, the monitoring camera of the measuring device 20 is installed in the space above the path 1 and captures images of the pallets 3A-3D that have reached the destination and the forks 51 of the autonomous forklift 5. Although not shown, a plurality of measurement sensors of the measuring device 20 are installed around the autonomous forklift 5 and around the arrival position of the autonomous transport robot 2.

Then, in order to insert the forks 51 of the autonomous forklift 5 into the fork pockets 32 of the pallets 3A to 3D that have reached the destination, the management device 10 determines whether or not there is any misalignment of the fork pockets 32 relative to the forks 51 based on the output of the measuring device 20, and if it determines that there is a misalignment, executes a process to correct the misalignment using the autonomous transport robot 2.

The control device 28 of the autonomous transport robot 2 executes a process to control the left drive wheel 25 and the right drive wheel 26 to correct the positional deviation in accordance with the positional deviation information input from the management device 10.

For example, the management device 10 recognizes the coordinates of predetermined positions on the outer periphery of the pallets 3A-3D (see, for example, measurement points X1-X6 in FIG. 3) based on the output of the monitoring camera of the measuring device 20 and a measurement sensor (not shown), and recognizes the coordinates of predetermined positions on the outer periphery of the forks 51 of the autonomous forklift 5, and by comparing the position and orientation of the forks 51 with the position and orientation of the fork pockets 32, determines whether or not the fork pockets 32 are misaligned relative to the forks 51.

Next, the procedure for transferring pallets 3A to 3D from an autonomous mobile transport robot 2 to another autonomous mobile transport robot 2n will be described with reference to Figures 6 to 8. Note that Figures 6 to 8 show simplified configurations and shapes of each part.

In this embodiment, although not shown, a platform 4 on which four pallets 3A-3D, each containing cargo, are stacked vertically is placed at a predetermined position on the moving path 1.

The management device 10 inputs information such as the pick-up location for picking up the platform 4 on which the four pallets 3A-3D are stacked, and the destination (waiting location for the autonomous forklift 5) to which the four pallets 3A-3D are transported to, to the control device 28 of the autonomous transport robot 2, while inputting information such as the pallets to be lifted by the autonomous forklift 5 at the destination (the three pallets 3B-3D above the second tier from the bottom out of the four pallets 3A-3D) to the control device (not shown) of the autonomous forklift 5.

First, the control device 28 of the autonomous mobile transport robot 2 controls the autonomous mobile transport robot 2 to arrive at the location of the platform 4 on which the four pallets 3A to 3D are stacked vertically, based on the information on the pick-up location.

When the autonomous transport robot 2 reaches the pick-up location, the autonomous transport robot 2 slides under the platform 4, and then the lift table 22 of the autonomous transport robot 2 is raised to lift the platform 4 and place it on the vehicle body 21.

Then, the control device 28 of the autonomous mobile transport robot 2 controls the autonomous mobile transport robot 2 to reach the destination based on the destination information.

The autonomous traveling of the autonomous traveling transport robot 2 is performed by the control device 28 recognizing a plurality of guide markers (not shown) installed on the moving path 1 one by one using the lower camera 6 installed on the autonomous traveling transport robot 2, and based on the recognition results, confirming that the actual moving path of the autonomous traveling transport robot 2 does not deviate from the moving path.

In this way, the control device 28 checks the travel path of the autonomous mobile transport robot 2 while it is autonomously traveling, thereby enabling it to accurately control the travel of the autonomous mobile transport robot 2.

In this way, when the autonomous transport robot 2 reaches the destination and stops, the lift table 22 of the autonomous transport robot 2 is lowered to bring the leg 42 of the platform 4 into contact with the travel path 1 and move the lift table 22 away from the platform 4.

Then, based on the information on the three pallets 3B-3D to be lifted, the control device (not shown) of the autonomous forklift 5 executes a process to transfer the three pallets 3B-3D on the autonomous transport robot 2 that has reached the destination onto a platform 4n on another autonomous transport robot 2n shown in FIG. 7.

Specifically, as shown in FIG. 6, the three pallets 3B to 3D to be lifted from the autonomous transport robot 2 that has reached the destination are lifted by an autonomous forklift 5, and then the autonomous forklift 5 is moved backwards to separate them from the platform 4.

After this, as shown in FIG. 7, the self-driving forklift 5 carrying the three pallets 3B to 3D is moved to a location where a platform 4n other than the platform 4 that has reached the destination is located.

Next, as shown in FIG. 8, the self-driving forklift 5 carrying the three pallets 3B-3D is moved forward to approach the platform 4n, and the support 52 of the self-driving forklift 5 is slid forward together with the forks 51 to place the three pallets 3B-3D on the forks 51 on the platform 4n, and then the forks 51 are lowered to load the three pallets 3B-3D onto the platform 4n.

In the process of lifting the three pallets 3B to 3D to be lifted from the autonomous transport robot 2 that has reached the destination with the forks 51 of the autonomous forklift 5, the management device 10 causes the measuring device 20 to measure the positional deviation of the fork pocket 32 of the second-lowest pallet 3B relative to the forks 51.

Incidentally, the platform 4 is mounted at the center P of the lift table 22 of the autonomous transport robot 2, and the control device 28 of the autonomous transport robot 2 detects guide markers (not shown) installed on the travel path 1 with the lower camera 6 to stop the autonomous transport robot 2 at the destination. Therefore, the autonomous transport robot 2 and the platform 4 are accurately positioned in the X-axis direction and the Y-axis direction at the destination. However, the control device 28 of the autonomous transport robot 2 is not configured to recognize the orientation θ of the autonomous transport robot 2 and the platform 4 relative to the forks 51 of the self-driving forklift 5 at the destination.

In addition, the control device 28 of the autonomous transport robot 2 is not configured to recognize the X-axis position, Y-axis position, and orientation θ of the pallets 3A to 3D on the stand 4.

Furthermore, the lower ends of the legs 31 of each of the four pallets 3A to 3D are positioned by engaging with the upper ends of the supports (reference numbers omitted), but a small amount of clearance is provided in the lateral direction (the X-axis and Y-axis directions of the pallets 3A to 3D) at each of the engaging portions.

Because of these factors, it is possible that the position of the fork pocket 32 of the second-lowest pallet 3B may shift relative to the forks 51 of the autonomous forklift 5 at the destination.

The management device 10 then determines whether or not there is misalignment of the fork pocket 32 of the second pallet from the bottom 3B relative to the forks 51 based on the output of the measuring device 20, and if it determines that there is a misalignment, inputs information to correct the misalignment to the control device 28 of the autonomous mobile transport robot 2.

The control device 28 controls the left drive wheel 25 and the right drive wheel 26 of the autonomous transport robot 2 to correct the positional deviation. The correction work by the control device 28 uses the output of the measuring device 20 detected by the management device 10.

The left drive wheel 25 and the right drive wheel 26 are driven independently to generate drive force for moving the autonomous transport robot 2 forward, backward, sideways, and rotate, making it easy to control the orientation θ of the autonomous transport robot 2.

Therefore, correcting the positional deviation using the autonomous transport robot 2 can be done more easily and quickly than correcting the positional deviation using an autonomous forklift 5.

As described above, according to the embodiment of the present invention, it becomes possible to quickly and accurately insert the forks 51 of the autonomous forklift 5 into the fork pockets 32 of any of the pallets 3A-3D on the platform 4 mounted on the autonomous transport robot 2 that has stopped at the destination.

This makes it possible to quickly carry out the process from stopping the autonomous transport robot 2 at the destination to lifting any one of the pallets 3A-3D on the autonomous transport robot 2 with the automatically operated forklift 5.

Therefore, for example, when transferring pallets 3A-3D from an autonomous transport robot 2 to another autonomous transport robot 2n by an automatically operated forklift 5, this is advantageous in shortening the transfer work time.

The present invention is not limited to the configuration described in the above embodiment, but may be modified as appropriate within the scope of the claims and equivalents thereto.

(1) In the above embodiment, there are no particular limitations on the configuration of the autonomous transport robot 2 or the external shape of the vehicle body 21.

(2) In the above embodiment, an example is given in which the pallet 3A is not configured to be engaged and positioned on the stand 4, but the present invention is not limited to this. Although not shown, it is possible to configure the pallet 3A to be engaged and positioned on the stand 4.

The present invention can be suitably used in a transport system.

1. Travel path 2. Autonomous transport robot 2n. Other autonomous transport robots
21 Body
22 Lifting table
23 Front driven wheel
24 Rear driven wheel
25 Left drive wheel
25a Motor
25b Encoder
26 Right drive wheel
26a Motor
26b Encoder
27a, 27b LiDAR sensor
28 Control device
28a Interface 3A-3D Palette
31 Legs
32 Fork pocket 4 Stand
41 Torso
42 Legs 4n Other platforms 5 Automatic forklift
51 Fork
52 Support 6 Lower camera 7 Upper camera 10 Management device 20 Measuring device P Center of lift table X1 to X6 Measuring points

Claims (1)

The system includes a plurality of pallets on which cargo is stored, a stand on which the plurality of pallets are vertically stacked, an autonomous mobile transport robot that crawls into a space below the stand and travels while holding up the stand, an automatically operated forklift that is on standby in the vicinity of a destination to which the pallets are to be transported and that lifts up and carries the required pallet from the autonomous mobile transport robot when the autonomous mobile transport robot reaches the destination, a measuring device that measures the position of the pallet on the autonomous mobile transport robot when the autonomous mobile transport robot reaches the destination, and a management device that executes the following processes:
A fork pocket into which the forks of the autonomous forklift are inserted is provided at the bottom of the pallet,
The autonomous traveling transport robot includes a lift table for raising and lowering the platform, and drive wheels for generating a drive force for moving forward, backward, sideways, and rotating;
The management device performs a process of measuring the position of the pallet on the autonomous mobile transport robot and the position of the fork by the measuring device when the autonomous mobile transport robot equipped with a platform on which the plurality of pallets are stacked reaches the destination;
a process of determining whether or not there is misalignment of the fork pocket relative to the fork based on the output of the measuring device, and if it is determined that there is misalignment, correcting the misalignment using the autonomous mobile transport robot.

Images