JP7760892B2 - Self-propelled transport device and control system - Google Patents

Description

The present invention relates to a self-propelled transport device and a control system.

Self-propelled transport devices such as mobile robots lift carts and move about. Patent Document 1 discloses a mechanical technology for transporting cargo stably.

Japanese Patent Application Laid-Open No. 2006-123854

When cargo is placed on a cart, the center of gravity of the cart will vary depending on how the cargo is placed on the cart. If a self-propelled transport device lifts the cart without taking the center of gravity of the cart into consideration, vibrations may occur while the self-propelled transport device is moving, or the self-propelled transport device may tip over while moving.

The present invention was made in consideration of the above-mentioned circumstances, and its purpose is to provide technology that enables a self-propelled transport device to travel stably when lifting a carriage and traveling.

A self-propelled conveying device according to one aspect of the present invention is a self-propelled conveying device that can travel and includes: a plurality of pins each equipped with a sensor that measures a load; a lifting mechanism that can raise and lower the plurality of pins; a control unit that controls the lifting mechanism and acquires load data measured by the sensor when the plurality of pins are raised and in contact with the bottom surface of a dolly carrying at least one load, and the dolly is lifted; and a memory unit that stores the position of the center of gravity of the self-propelled conveying device, wherein the control unit calculates the position of the center of gravity of the dolly based on the load data, and controls the lifting mechanism to lift the dolly when the position of the center of gravity of the self-propelled conveying device and the position of the center of gravity of the dolly are in a predetermined positional relationship.

The control unit controls the lifting mechanism to lift the cart when the center of gravity of the self-propelled transport device and the center of gravity of the cart are in a predetermined positional relationship. This prevents vibrations and the cart from tipping over when the self-propelled transport device transports the cart, allowing the self-propelled transport device to transport the cart stably. This allows the self-propelled transport device to travel stably when it lifts the cart and travels.

The predetermined positional relationship may include a predetermined area including the center of gravity of the self-propelled transport device and the center of gravity of the carriage overlapping in the vertical direction. The predetermined positional relationship may include a predetermined area including the center of gravity of the self-propelled transport device and the center of gravity of the carriage overlapping in the vertical direction. The predetermined positional relationship may include a predetermined area including the center of gravity of the self-propelled transport device and the center of gravity of the carriage overlapping in the vertical direction.

The control unit may adjust at least one of the traveling speed and the turning radius of the self-propelled transport device when there is a change in the position of the center of gravity of the carriage while the self-propelled transport device is traveling. The control unit may move the self-propelled transport device so that the position of the center of gravity of the self-propelled transport device and the position of the center of gravity of the carriage are in the predetermined positional relationship. The self-propelled transport device may include a request unit that requests an operator to move the carriage so that the position of the center of gravity of the self-propelled transport device and the position of the center of gravity of the carriage are in the predetermined positional relationship.

The self-propelled transport device may include an imaging device that captures images of the dolly and the at least one piece of luggage, the imaging device generating image data of the dolly and the at least one piece of luggage, and the control unit acquiring the loading state of the luggage on the dolly from the image data and determining the position at which the self-propelled transport device will slide under the bottom surface of the dolly based on the loading state of the luggage. The number of pins may be three or more.

A control system according to one aspect of the present invention comprises a plurality of self-propelled transport devices capable of traveling; and a host device capable of communicating with the plurality of self-propelled transport devices. The plurality of self-propelled transport devices each have a plurality of pins equipped with sensors that measure loads, a lifting mechanism that can raise and lower the plurality of pins, and a control unit that controls the lifting mechanism and acquires load data measured by the sensors when the plurality of pins are raised and the dolly is lifted while in contact with the bottom surface of a dolly carrying at least one load. The host device has a memory unit that stores the dimensions of the plurality of self-propelled transport devices and the dimensions of the dolly. The control unit sends the load data to the host device, and the host device issues a transport instruction for the dolly to one of the plurality of self-propelled transport devices based on the load data, the dimensions of the plurality of self-propelled transport devices, and the dimensions of the dolly.

This invention provides technology that allows a self-propelled transport device to travel stably when lifting a carriage.

FIG. 1 is a block diagram showing the configuration of a mobile robot according to the first embodiment. FIG. 2 is a perspective view of a mobile robot. FIG. 3 is an explanatory diagram of lifting a cart by a mobile robot. 4A and 4B are diagrams illustrating lifting of a cart by a mobile robot. FIG. 5 is a top view of the mobile robot. FIG. 6 is a perspective view of the mobile robot and the cart. FIG. 7 is a perspective view of the mobile robot and the cart. FIG. 8 is a perspective view of the mobile robot and the cart. FIG. 9 is a perspective view of the carriage. FIG. 10 is a schematic diagram illustrating an example of a control system according to the first embodiment. FIG. 11 is a flowchart showing the processing flow in the mobile robot according to the first embodiment. FIG. 12 is a flowchart showing the flow of the process for checking the weight of the cart. FIG. 13 is a flowchart showing the flow of the process for checking the weight position of the carriage. FIG. 14 is a flowchart showing the flow of the process for determining whether or not movement is possible. FIG. 15 is a flowchart showing the flow of processing in the higher-level device according to the first embodiment. FIG. 16 is a schematic diagram illustrating an example of a control system according to the second embodiment. FIG. 17 is a block diagram showing the configuration of a mobile robot for load measurement according to the second embodiment. FIG. 18 is a perspective view of a mobile robot for load measurement. FIG. 19 is a flowchart showing the processing flow of the load measurement mobile robot according to the second embodiment. FIG. 20 is a flowchart showing the flow of processing in the higher-level device according to the second embodiment. FIG. 21 is a flowchart showing the processing flow in the mobile robot and the host device according to the third embodiment.

Hereinafter, embodiments will be described with reference to the drawings. The embodiment described below is one aspect of the present application and does not limit the scope of the present application.
<Application example>
An example of a situation in which the present invention is applied will be described.

First Embodiment
<Overall configuration of the mobile robot>
FIG. 1 is a block diagram showing the configuration of a mobile robot 1 according to a first embodiment. The mobile robot 1 functions as a self-propelled automated guided vehicle (self-propelled transport device). The mobile robot 1 includes an integrated control unit (controller) 11, a communication unit 12, a travel control unit 13, a lift control unit 14, a travel unit 15, a memory unit 16, a lift mechanism 17, multiple pins 18, an imaging device 19, and multiple load sensors 20. The host device 2 communicates with the mobile robot 1 and issues specific transport instructions to a specific mobile robot 1 in the transport system it manages. The host device 2 includes a memory device 201 and an input device 202. The memory device 201 stores various information and data. The input device 202 accepts input of various information and data. The host device 2 may be a server, workstation, personal computer, or other device.

The integrated control unit 11 performs integrated control of the mobile robot 1, including coordination with the running unit 15 and lifting mechanism 17 and management of communications with the host device 2. The communication unit 12 is a communications interface that communicates with the host device 2. The integrated control unit 11 receives instructions from the host device 2 via the communication unit 12 and controls the running unit 15 in accordance with the instructions to move (run) the mobile robot 1. The running control unit 13 controls the running unit 15 based on instructions from the integrated control unit 11. The running control unit 13 may be omitted and the integrated control unit 11 may control the running unit 15. Alternatively, the integrated control unit 11 and the running control unit 13 may be integrated. The lifting control unit 14 controls the lifting mechanism 17 based on instructions from the integrated control unit 11. The lifting control unit 14 may be omitted and the integrated control unit 11 may control the lifting mechanism 17. The integrated control unit 11 and the lifting control unit 14 may be integrated. Alternatively, the integrated control unit 11, the running control unit 13, and the lifting control unit 14 may be integrated.

The running unit 15 causes the mobile robot 1 to run. The running unit 15 has multiple rotating bodies 21 and can run by controlling the forward and reverse rotation of the multiple rotating bodies 21. The rotating bodies 21 have wheels and tires. The running unit 15 may also have multiple casters 22. The casters 22 assist the running of the mobile robot 1. The running unit 15 has a right motor drive unit 23, a left motor drive unit 24, a right motor 25, and a left motor 26.

The driving control unit 13 controls the right motor drive unit 23 and the left motor drive unit 24 based on driving command signals from the integrated control unit 11. The right motor drive unit 23 controls the drive of the right motor 25, thereby rotating the rotating body 21 located on the right side of the mobile robot 1. The left motor drive unit 24 controls the drive of the left motor 26, thereby rotating the rotating body 21 located on the left side of the mobile robot 1. The driving unit 15 is equipped with an encoder that acquires data regarding the number of rotations of the rotating body 21. The data regarding the number of rotations of the rotating body 21 is sent to the integrated control unit 11 or the driving control unit 13. The integrated control unit 11 or the driving control unit 13 calculates the traveling distance of the mobile robot 1 based on the data regarding the number of rotations of the rotating body 21.

The traveling unit 15 is also equipped with a monitoring sensor that monitors the direction ahead in which the mobile robot 1 is traveling, an acceleration sensor for detecting the traveling status and position of the mobile robot 1, and various other sensors. The monitoring sensor is a distance sensor such as LiDAR, and can acquire data (distance image) indicating the distance to objects within the monitoring sensor's monitoring range. The memory unit 16 stores calculation data resulting from calculations performed by the integrated control unit 11, as well as various information and data.

The lifting mechanism 17 is a device for raising or lowering multiple pins 18, and is capable of raising and lowering the multiple pins 18. The lifting mechanism 17 has a motor drive unit 31 and a motor 32. The lifting control unit 14 controls the motor drive unit 31 based on a lift command signal from the integrated control unit 11. The motor drive unit 31 controls the drive of the motor 32, causing the multiple pins 18 to move vertically upward or downward. The multiple pins 18 arranged on the top surface of the mobile robot 1 may be raised or lowered. The lifting mechanism 17 may move each of the multiple pins 18 independently. The multiple pins 18 may be raised or lowered at different times, or the multiple pins 18 may be raised or lowered at the same time.

Multiple pins 18 may be fixed to a single plate placed on the top surface of the mobile robot 1. The motor drive unit 31 controls the drive of the motor 32 to vertically move the plate to which the pins 18 are fixed, thereby raising or lowering all of the multiple pins 18 simultaneously.

Figure 2 is a perspective view of the mobile robot 1. In the example of the mobile robot 1 shown in Figure 2, pins 18A-18D and load sensors 20A-20D are arranged on the top surface of the mobile robot 1. The number of pins 18 and load sensors 20 is not limited to the example shown in Figure 2; three pins 18 and three load sensors 20 may be arranged on the top surface of the mobile robot 1, or five or more pins 18 and five or more load sensors 20 may be arranged on the top surface of the mobile robot 1. Load sensor 20A is arranged at the tip of pin 18A, and load sensor 20B is arranged at the tip of pin 18B. Furthermore, load sensor 20C is arranged at the tip of pin 18C, and load sensor 20D is arranged at the tip of pin 18D.

The mobile robot 1 can lift a dolly by crawling under the bottom of the dolly. Figures 3, 4(A), and 4(B) are explanatory diagrams of the mobile robot 1 lifting the dolly 3. Figure 3 is a perspective view of the mobile robot 1 and dolly 3 when the mobile robot 1 crawls under the bottom of the dolly 3. The dolly 3 is loaded with multiple pieces of luggage 4, but the dolly 3 may also carry only one piece of luggage 4. Casters 5 are provided on the bottom of the dolly 3. When the dolly 3 is placed on the floor, the bottom of the dolly 3 faces the floor. The mobile robot 1 crawls under the bottom of the dolly 3 and raises pins 18A-18D, pressing them against the bottom of the dolly 3. When the mobile robot 1 crawls under the bottom of the dolly 3, the top of the mobile robot 1 faces the bottom of the dolly 3. The mobile robot 1 lifts the cart 3 by raising the pins 18A-18D while they are in contact with the bottom surface of the cart 3. Figures 4(A) and 4(B) are side views of the mobile robot 1 when it is lifting the cart 3.

The load sensor 20A measures a load (F1) applied to the load sensor 20A. The load sensor 20B measures a load (F2) applied to the load sensor 20B. The load sensor 20C measures a load (F3) applied to the load sensor 20C. The load sensor 20D measures a load (F4) applied to the load sensor 20D.
The load (F4) applied to pins 18A to 18D is measured. The load data measured by load sensors 20A to 20D is sent to integrated control unit 11. In this manner, integrated control unit 11 acquires the load data measured by load sensors 20A to 20D when pins 18A to 18D lift cart 3.

The integrated control unit 11 measures the load weight based on the load data from the load sensors 20A-20D. When no luggage 4 is loaded on the dolly 3, the load weight is the weight of the dolly 3. In other words, when no luggage 4 is loaded on the dolly 3, the load weight includes only the weight of the dolly 3. When luggage 4 is loaded on the dolly 3, the load weight is the total weight of the dolly 3 and the weight of the luggage 4. In other words, the load weight includes the weight of the dolly 3 and the weight of the luggage 4. The integrated control unit 11 calculates (measures) the center of gravity position (load center of gravity position) of the dolly 3 based on the load data from the load sensors 20A-20D.

Load sensors 20A-20D may be installed in any position on the top surface of the mobile robot 1. Figure 5 is a top view of the mobile robot 1. In a plan view (top view), Figure 5 shows the center line CL1 in the front-to-rear direction of the mobile robot 1, the center line CL2 in the left-to-right direction of the mobile robot 1, and the intersection P1 between center lines CL1 and CL2. Load sensors 20A and 20D are installed on a line L1 that passes through intersection P1. Load sensors 20B and 20C are installed on a line L2 that passes through intersection P1. The installation positions of load sensors 20A-20D on the top surface of the mobile robot 1 are not limited to the positions shown in Figure 5. The origin of the coordinates [X1, Y1] of the installation position of load sensor 20A, the coordinates [X2, Y2] of the installation position of load sensor 20B, the coordinates [X3, Y3] of the installation position of load sensor 20C, and the coordinates [X4, Y4] of the installation position of load sensor 20D may be intersection point P1.

Figure 5 shows distance D1 from intersection P1 to the installation position of load sensor 20A, distance D2 from intersection P1 to the installation position of load sensor 20B, distance D3 from intersection P1 to the installation position of load sensor 20C, and distance D4 from intersection P1 to the installation position of load sensor 20D. Distances D1 to D4 may be the same, or distances D1 to D4 may be different. Two of distances D1 to D4 (e.g., distances D1 and D2) may be the same, and two other of distances D1 to D4 (e.g., distances D3 and D4) may be the same (in this case, distance D1 ≠ distance D3). Three of distances D1 to D4 (e.g., distances D1, D2, and D3) may be the same (in this case, distance D1 ≠ distance D4).

Load sensors 20A-20D may be installed near the outer periphery of the top surface of the mobile robot 1. When load sensors 20A-20D are installed near the outer periphery of the top surface of the mobile robot 1, pins 18A-18D are installed near the outer periphery of the top surface of the mobile robot 1, allowing the mobile robot 1 to stably lift the cart 3.

The following describes the operation of the mobile robot 1 when it transports a dolly 3. For example, when transporting the dolly 3 from a first predetermined location to a second predetermined location, the host device 2 sends an instruction to the mobile robot 1 to transport the dolly 3. The instruction to transport the dolly 3 includes an instruction to transport the dolly 3 from the first predetermined location to the second predetermined location. When the mobile robot 1 receives the instruction to transport the dolly 3 from the host device 2, it moves to the first predetermined location and crawls under the bottom of the dolly 3 placed in the first predetermined location.

The position at which the mobile robot 1 slides under the bottom surface of the dolly 3 is arbitrary. The mobile robot 1 may move so that a predetermined position on the bottom surface of the dolly 3 and a predetermined position on the top surface of the mobile robot 1 overlap in the vertical direction. The mobile robot 1 may move so that a predetermined range on the bottom surface of the dolly 3 and a predetermined position on the top surface of the mobile robot 1 overlap in the vertical direction.
The mobile robot 1 may move so that the predetermined area on the top surface of the mobile robot 1 overlaps with the predetermined area on the top surface of the mobile robot 1 in the vertical direction.

The higher-level device 2 may notify the mobile robot 1 of a predetermined position or predetermined range on the bottom surface of the cart 3. The predetermined position or predetermined range on the bottom surface of the cart 3 may be stored in advance in the mobile robot 1. The predetermined position on the bottom surface of the cart 3 may be the center position of the bottom surface of the cart 3, or a position near the center position of the bottom surface of the cart 3. The predetermined range on the bottom surface of the cart 3 may include the center position of the bottom surface of the cart 3 and a position near the center position of the bottom surface of the cart 3.

The predetermined position on the top surface of the mobile robot 1 may be the intersection point P1 between the center lines CL1 and CL2 of the mobile robot 1. The predetermined position on the top surface of the mobile robot 1 may be a position near the intersection point P1. The predetermined range on the top surface of the mobile robot 1 may include the intersection point P1 and a position near the intersection point P1.

The mobile robot 1 lifts the dolly 3 while crawling under the bottom of the dolly 3 and measures the load weight. Specifically, the integrated control unit 11 measures the load weight based on the load data from the load sensors 20A-20D. The integrated control unit 11 determines whether the measured load weight exceeds the load capacity (transportable weight) of the mobile robot 1. If the measured load weight exceeds the load capacity of the mobile robot 1, the integrated control unit 11 notifies the host device 2 that the dolly 3 cannot be transported. If the measured load weight does not exceed the load capacity of the mobile robot 1, the integrated control unit 11 calculates the position of the center of gravity of the dolly 3. Specifically, the integrated control unit 11 calculates the position of the center of gravity of the dolly 3 based on the load data from the load sensors 20A-20D.

The integrated control unit 11 may calculate the center of gravity position (coordinates of the center of gravity) of the cart 3 using an XY coordinate system with the origin at the intersection P1 of the center lines CL1 and CL2 of the mobile robot 1. The integrated control unit 11 calculates the center of gravity position (Xg) of the cart 3 in the X-axis direction based on the following (Equation 1), and calculates the center of gravity (Yg) of the cart 3 in the Y-axis direction based on the following (Equation 2), thereby calculating the center of gravity position (Xg, Yg) of the cart 3.
Center of gravity position (Xg) of the carriage 3 = (F1 x X1 + F2 x X2 + F3 x X3 + F4 x X4) / (F1 + F2 + F3 + F4) (Equation 1)
Center of gravity position (Yg) of the carriage 3=(F1×Y1+F2×Y2+F3×Y3+F4×Y4)/(F1+F2+F3+F4) (Equation 2)
F1 to F4: Loads applied to the load sensors 20A to 20D X1, Y1: Coordinates of the installation position of the load sensor 20A X2, Y2: Coordinates of the installation position of the load sensor 20B X3, Y3: Coordinates of the installation position of the load sensor 20C X4, Y4: Coordinates of the installation position of the load sensor 20B

The integrated control unit 11 acquires the center of gravity of the mobile robot 1. The center of gravity (X, Y) of the mobile robot 1 may be, for example, the intersection point P1 of the center lines CL1 and CL2 of the mobile robot 1.
The center of gravity (X, Y) of the mobile robot 1 can be calculated using the following equations (3) and (4).
Center of gravity (X) of mobile robot 1 = (X1 + X2 + X3 + X4)/4 (Equation 3)
Center of gravity position (Y) of mobile robot 1 = (Y1 + Y2 + Y3 + Y4) / 4 (Equation 4)

When the distances D1 to D4 are the same, the center of gravity position (X, Y) of the mobile robot 1 can be calculated using the following (Equation 5) and (Equation 6).
Center of gravity position of mobile robot 1 (X) = (X1 + X2)/2 (Equation 5)
Center of gravity position of mobile robot 1 (Y) = (Y1 + Y3)/2 (Equation 6)

The memory unit 16 stores the position of the center of gravity of the mobile robot 1. The position of the center of gravity of the mobile robot 1 may be determined in advance by a worker such as a user, or may be determined during design. The integrated control unit 11 may read the position of the center of gravity of the mobile robot 1 from the memory unit 16. The memory unit 16 may also store the installation positions of the load sensors 20A-20D. The installation positions of the load sensors 20A-20D may be determined in advance by a worker, or may be determined during design. The integrated control unit 11 may read the installation positions of the load sensors 20A-20D from the memory unit 16 and calculate the position of the center of gravity of the mobile robot 1 based on the installation positions of the load sensors 20A-20D.

The integrated control unit 11 determines whether the mobile robot 1 can physically move to a position corresponding to the center of gravity of the cart 3 based on layout information related to the dimensions of the mobile robot 1 and the cart 3. That is, the integrated control unit 11 determines whether the mobile robot 1 can lift the cart 3 at a position corresponding to the center of gravity of the cart 3 without coming into contact with the cart 3. If the mobile robot 1 comes into contact with the cart 3 when it moves to a position corresponding to the center of gravity of the cart 3, it may be determined that the mobile robot 1 cannot physically move to a position corresponding to the center of gravity of the cart 3. The layout information may be stored in the memory unit 16. The integrated control unit 11 may receive the layout information from the higher-level device 2.

The integrated control unit 11 may determine a position corresponding to the center of gravity of the cart 3 based on the positions of the center of gravity of the mobile robot 1 and the cart 3. The position corresponding to the center of gravity of the cart 3 may be a position where the positions of the center of gravity of the mobile robot 1 and the cart 3 overlap in the vertical direction. The position corresponding to the center of gravity of the cart 3 may be a position where a predetermined area including the position of the center of gravity of the cart 3 and the position of the center of gravity of the mobile robot 1 overlap in the vertical direction. The position corresponding to the center of gravity of the cart 3 may be a position where the positions of the center of gravity of the cart 3 and the position of the center of gravity of the mobile robot 1 overlap in the vertical direction.

If the mobile robot 1 cannot physically move to a position corresponding to the center of gravity of the cart 3, the mobile robot 1 notifies the host device 2 that the cart 3 cannot be transported. If the mobile robot 1 can physically move to a position corresponding to the center of gravity of the cart 3, the mobile robot 1 moves to that position. Figure 6 is a perspective view of the mobile robot 1 and cart 3 when the mobile robot 1 has moved to a position corresponding to the center of gravity of the cart 3. In Figure 6, the centers of gravity of the mobile robot 1 and cart 3 are located on a vertical line passing through point P2.

After the mobile robot 1 moves to a position corresponding to the center of gravity of the cart 3, the integrated control unit 11 determines whether the center of gravity of the mobile robot 1 and the center of gravity of the cart 3 are in a predetermined positional relationship. If the center of gravity of the mobile robot 1 and the center of gravity of the cart 3 are in the predetermined positional relationship, the integrated control unit 11 controls the lifting mechanism 17 to lift the cart 3. The predetermined positional relationship may include a predetermined area including the center of gravity of the mobile robot 1 overlapping the center of gravity of the cart 3 in the vertical direction. The predetermined positional relationship may include a predetermined area including the center of gravity of the mobile robot 1 overlapping the center of gravity of the cart 3 in the vertical direction. With the cart 3 lifted, the mobile robot 1 transports the cart 3 to a specified location (e.g., a second specified location) in accordance with a transport command for the cart 3 from the host device 2.

Before the mobile robot 1 transports the cart 3, the mobile robot 1 moves to a position corresponding to the center of gravity of the cart 3, and then lifts the cart 3 at the new position. Specifically, the integrated control unit 11 controls the travel unit 15 to move the mobile robot 1 so that the center of gravity of the mobile robot 1 and the center of gravity of the cart 3 are aligned in a predetermined positional relationship. Then, once the center of gravity of the mobile robot 1 and the center of gravity of the cart 3 are aligned in a predetermined positional relationship, the integrated control unit 11 controls the lifting mechanism 17 to lift the cart 3. This prevents vibrations and tipping of the cart 3 when the mobile robot 1 transports the cart 3, allowing the mobile robot 1 to transport the cart 3 stably. This allows the mobile robot 1 to travel stably while lifting the cart 3. Alternatively, the mobile robot 1 may move to a position corresponding to the center of gravity of the cart 3 so that the centers of gravity of the mobile robot 1 and the cart 3 overlap vertically, and then lift the cart 3 at the new position. In other words, when the center of gravity of the mobile robot 1 and the center of gravity of the cart 3 are vertically overlapping, the integrated control unit 11 controls the lifting mechanism 17 to lift the cart 3. This prevents the tires on one side from being burdened while the mobile robot 1 is moving, allowing the mobile robot 1 to transport the cart 3 stably and preventing uneven wear on the mobile robot 1's tires.

In the above example, four pins 18 and four load sensors 20 are placed on the top surface of the mobile robot 1, but by placing three or more pins 18 and three or more load sensors 20 on the top surface of the mobile robot 1, it is possible to calculate the center of gravity position of the cart 3.

The integrated control unit 11 may acquire load data from the load sensors 20A-20D while the mobile robot 1 is moving. While the mobile robot 1 is moving, the integrated control unit 11 may calculate the center of gravity of the cart 3 based on the load data from the load sensors 20A-20D. The integrated control unit 11 may compare the center of gravity of the cart 3 calculated before the mobile robot 1 starts moving with the center of gravity of the cart 3 calculated while the mobile robot 1 is moving. If the center of gravity of the cart 3 changes, the mobile robot 1 may notify the host device 2 of the change. If the center of gravity of the cart 3 changes while the mobile robot 1 is moving, the integrated control unit 11 may control the traveling unit 15 to adjust at least one of the traveling speed and turning radius of the mobile robot 1. Adjusting the traveling speed and turning radius of the mobile robot 1 can prevent vibrations and tipping of the cart 3 during transport.

The imaging device 19 is a camera that captures images of the dolly 3 and at least one piece of luggage 4 to generate captured images. The imaging device 19 captures images of the dolly 3 and luggage 4 at a predetermined frame rate and sequentially generates image data. The image data generated by the imaging device 19 is sent to the integrated control unit 11. The imaging device 19 has an optical system such as a lens, and an imaging element such as a CMOS (Complementary Metal Oxide Semiconductor) or a CCD (Charge Coupled Device).

The mobile robot 1 may crawl under the bottom of the dolly 3 after checking the load status of the luggage 4 on the dolly 3. As shown in FIG. 7 , the mobile robot 1 may check the load status of the luggage 4 on the dolly 3 before crawling under the bottom of the dolly 3. The mobile robot 1 may capture images of the dolly 3 and luggage 4 from multiple directions as it travels around the dolly 3. The integrated control unit 11 obtains the load status of the luggage 4 on the dolly 3 from image data of the dolly 3 and luggage 4, and determines the position at which to crawl under the bottom of the dolly 3 based on the load status of the luggage 4 on the dolly 3. When multiple luggage 4 are arranged close together, the integrated control unit 11 may determine the position at which to crawl under the bottom of the dolly 3 depending on the arrangement of the multiple luggage 4.

In Figure 8, the position where the mobile robot 1 should crawl under the bottom of the cart 3 is determined based on the arrangement of multiple pieces of luggage 4, and the mobile robot 1 crawls under the bottom of the cart 3 based on the determined position. As shown in Figure 8, when the mobile robot 1 crawls under the bottom of the cart 3, the mobile robot 1 and one or more pieces of luggage 4 overlap vertically. By determining the position where the mobile robot 1 should crawl under the bottom of the cart 3 based on the arrangement of multiple pieces of luggage 4, the integrated control unit 11 can stably lift the cart 3.

The integrated control unit 11 may check the loading status of the dolly 3 based on image data of the dolly 3 and the luggage 4, and may transmit information regarding the loading status of the dolly 3 to the higher-level device 2. For example, as shown in FIG. 9, if the luggage 4 is protruding from the dolly 3, there is a possibility that the luggage 4 will fall from the dolly 3 while the mobile robot 1 is moving. The integrated control unit 11 may determine whether there is a possibility that the luggage 4 will fall from the dolly 3 while the mobile robot 1 is moving, based on the arrangement of one or more pieces of luggage 4.

The integrated control unit 11 may transmit to the higher-level device 2 a message indicating that there is a possibility that the cargo 4 may fall from the cart 3 while the mobile robot 1 is moving. Alternatively, an alarm mechanism may be provided in the mobile robot 1, and the integrated control unit 11 may control the alarm mechanism. The alarm mechanism may sound an alarm around the mobile robot 1, thereby informing the operator that there is a possibility that the cargo 4 may fall from the cart 3 while the mobile robot 1 is moving.

<Overall configuration of the control system>
FIG. 10 is a schematic diagram showing an example of a control system according to the first embodiment. In FIG. 10, a host device 2 manages multiple mobile robots 1 (1A-1D). The host device 2 can communicate with the mobile robots 1A-1D. The host device 2 selects one of the mobile robots 1 and sends a command to the selected mobile robot 1 to transport the cart 3. The host device 2 may also select one of the mobile robots 1 according to a predetermined criterion. For example, the host device 2 may select the mobile robot 1 closest to the cart 3 to be transported.

In the example control system shown in Figure 10, mobile robot 1A and mobile robot 1B are the same size, mobile robot 1C is larger than mobile robots 1A and 1B, and mobile robot 1D is larger than mobile robots 1A, 1B, and 1C. The area of the top surface of mobile robot 1A is the same as the area of the top surface of mobile robot 1B. The area of the top surface of mobile robot 1C is larger than the area of the top surface of mobile robot 1A. The area of the top surface of mobile robot 1D is larger than the area of the top surface of mobile robot 1C.

Figure 11 is a flowchart showing the processing flow of the mobile robot 1 according to the first embodiment. The processing of the flowchart shown in Figure 11 begins when the host device 2 sends an instruction to the mobile robot 1 to transport the cart 3. The mobile robot 1 moves to a position near the cart 3 (S1) and slides under the bottom surface of the cart 3 (S2).

Before crawling under the bottom of the cart 3, the mobile robot 1 may travel around the cart 3, taking images of the cart 3 and the cargo 4, and confirm the loading status of the cart 3. If there is a possibility that the cargo 4 may fall from the cart 3 while the mobile robot 1 is moving, the integrated control unit 11 notifies the host device 2 that the cart 3 cannot be transported. The mobile robot 1 then enters a standby state and waits for instructions from the host device 2.

The mobile robot 1 lifts the dolly 3 (S3). The integrated control unit 11 measures the load distribution on the dolly 3 and calculates the center of gravity of the dolly 3 (S4). The integrated control unit 11 also measures the load weight. The mobile robot 1 lowers the dolly 3 (S5). The mobile robot 1 checks the weight of the dolly 3 (S6).

The flow of the process for confirming the weight of the dolly 3 (confirmation flow A) will be explained with reference to the flowchart in Figure 12. The integrated control unit 11 acquires luggage information from the higher-level device 2 (S21). The luggage information includes information regarding the weight of the luggage 4. The integrated control unit 11 determines whether the measured load weight is equal to or less than the loadable weight (allowable weight) (S22). If the measured load weight is equal to or less than the loadable weight (S22; YES), the process proceeds to S23.

The integrated control unit 11 calculates the weight of the luggage 4 (S23). Specifically, the integrated control unit 11 calculates the weight of the luggage 4 by subtracting the weight of the dolly 3 from the measured load weight. The weight of the dolly 3 is stored in the memory unit 16. The luggage information acquired from the higher-level device 2 may include information regarding the weight of the dolly 3. When information regarding the weight of the dolly 3 is sent from the higher-level device 2 to the mobile robot 1, the integrated control unit 11 may store the weight of the dolly 3 in the memory unit 16. The integrated control unit 11 determines whether the calculated weight of the luggage 4 is the same as the weight of the luggage 4 included in the luggage information (S24). If the calculated weight of the luggage 4 is the same as the weight of the luggage 4 included in the luggage information (S24; YES), the process proceeds to S7 in FIG. 11. Furthermore, if the process of S24 is disabled, the process proceeds to S7 in FIG. 11. In other words, the process of S24 may be omitted and the process may proceed to S7 in FIG. 11. For example, if the mobile robot 1 does not receive package information from the host device 2, it may skip step S24 and proceed to step S7 in Figure 11.

If the measured load weight exceeds the loadable weight (S22; NO), proceed to processing S13 in FIG. 11. Also, if the calculated weight of the luggage 4 differs from the weight of the luggage 4 included in the luggage information (S24; NO), proceed to processing S13 in FIG. 11. If the calculated weight of the luggage 4 differs from the weight of the luggage 4 included in the luggage information and processing S24 is enabled, proceed to processing S13 in FIG. 11.

Returning to the explanation of the flowchart in Figure 11, the mobile robot 1 confirms the position of the center of gravity of the cart 3 (S7). The flow of the process for confirming the weight position of the cart 3 (Confirmation Flow B) will be explained with reference to the flowchart in Figure 13. The integrated control unit 11 calculates the position of the center of gravity of the mobile robot 1 (S31). Based on the positions of the center of gravity of the mobile robot 1 and the cart 3, the integrated control unit 11 determines whether or not it is necessary to move the mobile robot 1 (S32).

The integrated control unit 11 may determine that the mobile robot 1 needs to be moved if the center of gravity of the mobile robot 1 and the center of gravity of the cart 3 do not overlap in the vertical direction. The integrated control unit 11 may determine that the mobile robot 1 needs to be moved if the difference between the center of gravity of the mobile robot 1 and the center of gravity of the cart 3 is equal to or greater than a predetermined value. The integrated control unit 11 may determine that the mobile robot 1 needs to be moved if a predetermined area including the center of gravity of the mobile robot 1 and the center of gravity of the cart 3 do not overlap in the vertical direction. The integrated control unit 11 may determine that the mobile robot 1 needs to be moved if the center of gravity of the mobile robot 1 and the predetermined area including the center of gravity of the cart 3 do not overlap in the vertical direction.

The predetermined area including the center of gravity of the mobile robot 1 may be, for example, a predetermined range in a planar direction from the center of gravity of the mobile robot 1. The predetermined area including the center of gravity of the carriage 3 may be a predetermined range in a planar direction from the center of gravity of the carriage 3. The predetermined value is stored in the memory unit 16. The predetermined value is, for example, 5 cm, but the operator can set any value as the predetermined value. The operator can also rewrite the predetermined value stored in the memory unit 16 to any value by issuing an instruction to the mobile robot 1 using an external device. The predetermined value stored in the memory unit 16 may also be rewritten to any value by issuing an instruction from the host device 2 to the mobile robot 1. The predetermined value stored in the memory unit 16 may also be rewritten to any value in response to a command from the host device 2 to the mobile robot 1 to transport the carriage 3.

If the mobile robot 1 needs to be moved (S32; YES), proceed to processing S8 in Figure 11. If the mobile robot 1 does not need to be moved (S32; NO), proceed to processing S10 in Figure 11.

Returning to the explanation of the flowchart in Figure 11, the mobile robot 1 determines whether it is capable of moving (S8). The flow of the process for determining whether it is capable of moving (determination flow) will be explained with reference to the flowchart in Figure 14. The integrated control unit 11 determines whether it is physically possible to move the mobile robot 1 to a position corresponding to the center of gravity of the cart 3 based on the layout information (S41). The layout information includes information on the dimensions of the mobile robot 1, the dimensions of the cart 3, etc. The layout information may also include information on the dimensions of multiple mobile robots 1, the dimensions of multiple carts 3, etc.

If the mobile robot 1 can be physically moved to a position corresponding to the center of gravity of the cart 3 (S41; YES), proceed to processing S9 in Figure 11. If the mobile robot 1 cannot be physically moved to a position corresponding to the center of gravity of the cart 3 (S41; NO), proceed to processing S13 in Figure 11.

Returning to the explanation of the flowchart in Figure 11, the mobile robot 1 moves to a position corresponding to the center of gravity of the cart 3 (S9). After the mobile robot 1 moves to a position corresponding to the center of gravity of the cart 3, the process proceeds to S3 in Figure 11.

The mobile robot 1 lifts the cart 3 (S10). The mobile robot 1 begins transporting the cart 3 (S11). That is, the mobile robot 1 starts moving with the cart 3 lifted, and begins transporting the cart 3 in accordance with the instructions for transporting the cart 3 from the higher-level device 2.

While the mobile robot 1 is moving, the integrated control unit 11 measures the load distribution on the cart 3 and calculates the position of the center of gravity of the cart 3 (S12). That is, while the mobile robot 1 is moving, the integrated control unit 11 acquires load data from the load sensors 20A-20D and calculates the position of the center of gravity of the cart 3 based on the load data from the load sensors 20A-20D.

The integrated control unit 11 compares the position of the center of gravity of the mobile robot 1 calculated before the mobile robot 1 starts moving with the position of the center of gravity of the mobile robot 1 calculated while the mobile robot 1 is moving. If the position of the center of gravity of the mobile robot 1 changes, the mobile robot 1 may notify the host device 2 of the change. If the position of the center of gravity of the cart 3 changes while the mobile robot 1 is moving, the integrated control unit 11 may control the traveling unit 15 to adjust at least one of the traveling speed and turning radius of the mobile robot 1. Adjusting the traveling speed and turning radius of the mobile robot 1 can prevent vibrations and tipping of the cart 3 while it is being transported. When the mobile robot 1 has transported the cart 3 to the designated location, it notifies the host device 2 that the transport is complete.

The integrated control unit 11 notifies the host device 2 that the carriage 3 cannot be transported (S13) and waits for instructions from the host device 2 (S14). The integrated control unit 11 also notifies the host device 2 of information regarding the reason why the carriage 3 cannot be transported. If the measured load weight exceeds the load capacity, the integrated control unit 11 notifies the host device 2 that the measured load weight exceeds the load capacity. If the calculated weight of the luggage 4 differs from the weight of the luggage 4 included in the luggage information, the integrated control unit 11 notifies the host device 2 that the calculated weight of the luggage 4 differs from the weight of the luggage 4 included in the luggage information. If the mobile robot 1 cannot be physically moved to a position corresponding to the center of gravity of the carriage 3, the integrated control unit 11 notifies the host device 2 that the mobile robot 1 cannot be physically moved to a position corresponding to the center of gravity of the carriage 3.

When the mobile robot 1 receives an evacuation command (evacuation request) from the host device 2, it moves to a position away from the carriage 3. The evacuation command is an instruction to evacuate from the carriage 3. When the mobile robot 1 receives an evacuation command from the host device 2, it may move to a predetermined position. Furthermore, each of the processes described above may be considered as a control method for the mobile robot 1.

Figure 15 is a flowchart showing the processing flow in the host device 2 according to the first embodiment. The host device 2 sends a transport instruction to the mobile robot 1 to transport the cart 3 (S51). The host device 2 receives a notification from the mobile robot 1 that transport of the cart 3 is complete or that transport of the cart 3 is not possible (S52). When the host device 2 receives a notification from the mobile robot 1 that transport of the cart 3 is complete, the processing of the flowchart shown in Figure 15 ends. When the host device 2 receives a notification that transport of the cart 3 is not possible, it sends an evacuation instruction to the mobile robot 1 that is unable to transport the cart 3 (S53). That is, the host device 2 sends an evacuation instruction to the mobile robot 1 that sent the transport instruction to the cart 3. Upon receiving the evacuation instruction, the mobile robot 1 evacuates. For example, the mobile robot 1 moves away from the cart 3 or to a predetermined position.

The host device 2 determines whether multiple mobile robots 1 are operating (S54). If multiple mobile robots 1 are operating (S54; YES), it acquires load data from the load sensors 20A-20D from the mobile robots 1 that are unable to transport the cart 3 (S55). The integrated control unit 11 may send the load data from the load sensors 20A-20D to the host device 2. The host device 2 measures the payload and calculates the center of gravity of the cart 3 based on the load data from the load sensors 20A-20D. The host device 2 may acquire the payload and center of gravity of the cart 3 from the mobile robots 1 that are unable to transport the cart 3.

The host device 2 searches for a mobile robot 1 that can respond based on the load weight, the center of gravity of the cart 3, and the layout information (S56). That is, the host device 2 selects a mobile robot 1 that can respond from among the multiple mobile robots 1 based on the load data from the load sensors 20A-120 and the layout information. The layout information is stored in the storage device 201 of the host device 2. The worker may send the layout information to the host device 2 using a terminal device that can communicate with the host device 2. The worker may input the layout information into the host device 2 using the input device 202 of the host device 2. The host device 2 may also select a mobile robot 1 that can respond from among the multiple mobile robots 1 based on the load data from the load sensors 120A-120D and the layout information.

The host device 2 may determine a position corresponding to the center of gravity of the cart 3 based on the center of gravity of the mobile robot 1 and the center of gravity of the cart 3. The host device 2 searches for a mobile robot 1 that can respond, provided that the following conditions (1) and (2) are met:
(1) The payload is less than the maximum payload capacity of the mobile robot 1.
(2) The mobile robot 1 can physically move to a position corresponding to the center of gravity of the cart 3.

The host device 2 determines whether a mobile robot 1 capable of handling the request is currently operating (S57). If a mobile robot 1 capable of handling the request is currently operating (S57; YES), the host device 2 sends a command to the mobile robot 1 capable of handling the request to transport the cart 3 (S58). After S58 is completed, the process proceeds to S52. When a mobile robot 1 capable of handling the request receives the command to transport the cart 3, the process shown in the flowchart of FIG. 11 begins.

If only one mobile robot 1 is operating (S54; NO), proceed to processing S59. If no mobile robot 1 is operating that can handle the situation (S57; NO), proceed to processing S59. The host device 2 instructs the worker to reload the luggage 4 onto the cart 3 (S59). The display device of the host device 2 may display information (e.g., a message) related to the instruction to reload the luggage 4 onto the cart 3. The audio output device of the host device 2 may output audio related to the instruction to reload the luggage 4 onto the cart 3. The host device 2 may transmit information (e.g., a message) related to the instruction to reload the luggage 4 onto the cart 3 to a terminal device that can communicate with the host device 2, and the terminal device may display information related to the instruction to reload the luggage 4 onto the cart 3.

The worker reloads the luggage 4 onto the cart 3. When the reloading of the luggage 4 onto the cart 3 is complete, the worker uses a terminal device that can communicate with the host device 2 to send a notification of the completion of the reloading of the luggage 4 onto the cart 3 to the host device 2. The worker may also use the input device 202 of the host device 2 to input a notification of the completion of the reloading of the luggage 4 onto the cart 3 to the host device 2. The host device 2 receives the notification of the completion of the reloading of the luggage 4 onto the cart 3 (S60). After the processing of S60 is performed, the process proceeds to S51.

Second Embodiment
A second embodiment will now be described. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and the description thereof will be omitted. The control systems according to the first and second embodiments may be combined as appropriate.

<Overall configuration of the control system>
FIG. 16 is a schematic diagram showing an example of a control system according to the second embodiment. In FIG. 16, a host device 2 manages one mobile robot 101 and multiple mobile robots 1 (1E to 1G). The mobile robot 101 is a mobile robot for load measurement.

In the example control system shown in Figure 16, the mobile robot 101 and the mobile robot 1E are the same size, the mobile robot 1F is larger than the mobile robots 101 and 1E, and the mobile robot G is larger than the mobile robots 101, 1E, and 1F. The area of the top surface of the mobile robot 101 is the same as the area of the top surface of the mobile robot 1E. The area of the top surface of the mobile robot 1F is larger than the area of the top surface of the mobile robot 101. The area of the top surface of the mobile robot 1G is larger than the area of the top surface of the mobile robot 1F.

Figure 17 is a block diagram showing the configuration of a mobile robot 101 according to the second embodiment. The mobile robot 101 is a device (self-propelled transport device) that functions as a self-propelled automated guided vehicle. The mobile robot 101 includes an integrated control unit (control device) 111, a communication unit 112, a travel control unit 113, a lift control unit 114, a travel unit 115, a memory unit 116, a lift mechanism 117, multiple pins 118, an imaging device 119, and multiple load sensors 120.

The running unit 115 has multiple rotating bodies 121. The running unit 115 may also have multiple casters 122. The running unit 115 has a right motor drive unit 123, a left motor drive unit 124, a right motor 125, and a left motor 126. The lifting mechanism 117 has a motor drive unit 131 and a motor 132. The configuration of the mobile robot 101 is similar to that of the mobile robot 1, so a detailed description of the configuration of the mobile robot 101 will be omitted.

Figure 18 is a perspective view of the mobile robot 101. In the example of the mobile robot 101 shown in Figure 18, pins 118A-118D and load sensors 120A-120D are arranged on the top surface of the mobile robot 101. The number of pins 118 and load sensors 120 is not limited to the example shown in Figure 18; three pins 118 and three load sensors 120 may be arranged on the top surface of the mobile robot 101, or five or more pins 118 and five or more load sensors 120 may be arranged on the top surface of the mobile robot 101.

Load sensor 120A is provided at the tip of pin 118A, and load sensor 120B is provided at the tip of pin 118B. Load sensor 120C is provided at the tip of pin 118C, and load sensor 120D is provided at the tip of pin 118D. Load sensor 120A measures the load applied to load sensor 120A. Load sensor 120B measures the load applied to load sensor 120B. Load sensor 120C measures the load applied to load sensor 120C. Load sensor 120D measures the load applied to load sensor 120D. The load data measured by load sensors 120A to 120D is sent to the integrated control unit 111. The integrated control unit 111 acquires the load data measured by load sensors 120A to 120D when pins 118A to 118D lift the trolley 3.

The upper device 2 instructs the mobile robot 101 to move to a position near the dolly 3 and also instructs the mobile robot 101 to lift the dolly 3. When the mobile robot 101 receives the move and lift instructions, it moves to a position near the dolly 3 and crawls under the bottom of the dolly 3. Once crawled under the bottom of the dolly 3, the mobile robot 101 lifts the dolly 3 and measures the load weight. In detail, the integrated control unit 111 measures the load weight based on the load data from the load sensors 120A-120D. If no luggage 4 is loaded on the dolly 3, the load weight is the weight of the dolly 3. If luggage 4 is loaded on the dolly 3, the load weight is the total weight of the dolly 3 and the luggage 4.

The integrated control unit 111 calculates the center of gravity of the cart 3 based on the load data from the load sensors 120A-120D. The integrated control unit 111 sends the load weight and center of gravity of the cart 3 to the host device 2. The host device 2 selects a mobile robot 1 that can handle the task from among multiple mobile robots 1 based on the load weight, center of gravity of the cart 3, and layout information. The host device 2 sends a transport instruction for the cart 3 to the mobile robot 1 that can handle the task. When a mobile robot 1 that can handle the task receives the transport instruction for the cart 3, the process shown in the flowchart in Figure 11 begins.

The integrated control unit 111 may also send load data from the load sensors 120A-120D to the host device 2. The host device 2 may measure the load weight based on the load data from the load sensors 120A-120D. The host device 2 may also calculate the position of the center of gravity of the cart 3 based on the load data from the load sensors 120A-120D. The host device 2 selects a mobile robot 1 that can respond from among multiple mobile robots 1 based on the load data from the load sensors 120A-120D and layout information.

For example, the host device 2 may randomly select one of multiple mobile robots 1 and send it an instruction to transport the cart 3. If the selected mobile robot 1 is unable to transport the cart 3, the time it takes for the selected mobile robot 1 to move to a position near the cart 3 is wasted, increasing the travel time of the mobile robot 1. According to the second embodiment, the host device 2 can select a mobile robot 1 that can handle the task from multiple mobile robots 1 using the payload weight and center of gravity of the cart 3 obtained from the mobile robot 101. This prevents the mobile robot 1 from increasing its travel time.

Figure 19 is a flowchart showing the processing flow of the mobile robot 101 according to the second embodiment. The host device 2 sends an instruction to the mobile robot 101 to lift the cart 3, and the mobile robot 101 receives the instruction to lift the cart 3, which starts the processing of the flowchart shown in Figure 19. The mobile robot 101 moves to a position near the cart 3 (S61) and slides under the bottom surface of the cart 3 (S62).

The mobile robot 101 lifts the dolly 3 (S63). The integrated control unit 111 measures the load distribution on the dolly 3 and calculates the position of the center of gravity of the dolly 3 (S64). The integrated control unit 111 also measures the load weight. The integrated control unit 111 sends the load weight and the position of the center of gravity of the dolly 3 to the host device 2 (S65). The integrated control unit 111 may also send load data from the load sensors 120A to 120D to the host device 2. The mobile robot 101 lowers the lifted dolly 3 (S66). The mobile robot 101 performs evacuation upon receiving an evacuation command (evacuation request) from the host device 2 (S67). The evacuation command is an instruction to evacuate from the dolly 3. For example, the mobile robot 101 moves to a position away from the dolly 3 or to a predetermined position. The mobile robot 101 transitions to a standby state and waits for instructions from the host device 2 (S68). Additionally, each of the processes described above may be considered as a method for controlling the mobile robot 101.

Figure 20 is a flowchart showing the processing flow in the host device 2 according to the second embodiment. The host device 2 sends an instruction to the mobile robot 101 to lift the cart 3 (S71). The host device 2 receives the payload weight and the center of gravity position of the cart 3 from the mobile robot 101 (S72). The host device 2 sends an evacuation instruction to the mobile robot 101 (S73).

The host device 2 searches for a mobile robot 1 that can respond based on the load weight, the center of gravity of the cart 3, and the layout information (S74). That is, the host device 2 selects a mobile robot 1 that can respond from multiple mobile robots 1. The layout information may be stored in the storage device 201 of the host device 2. The worker may send the layout information to the host device 2 using a terminal device that can communicate with the host device 2. The worker may input the layout information to the host device 2 using the input device 202 of the host device 2.

The host device 2 may determine a position corresponding to the center of gravity of the cart 3 based on the center of gravity of the mobile robot 1 and the center of gravity of the cart 3. The host device 2 searches for a mobile robot 1 that can respond, provided that the following conditions (1) and (2) are met:
(1) The payload is less than the maximum payload capacity of the mobile robot 1.
(2) The mobile robot 1 can physically move to a position corresponding to the center of gravity of the cart 3.

The host device 2 determines whether a capable mobile robot 1 is operating (S75). If a capable mobile robot 1 is operating (S75; YES), the host device 2 sends a transport instruction for the carriage 3 to the capable mobile robot 1 (S76). The host device 2 may also send movement information to the capable mobile robot 1. The movement information includes information regarding a position corresponding to the center of gravity of the carriage 3. When the capable mobile robot 1 receives the transport instruction for the carriage 3, the process of the flowchart shown in FIG. 11 is initiated. The capable mobile robot 1 may use the position corresponding to the center of gravity of the carriage 3 as the position for slipping under the bottom surface of the carriage 3.

If a compatible mobile robot 1 is not operating (S75; NO), the host device 2 instructs the worker to reload the luggage 4 onto the cart 3 (S77). The display device of the host device 2 may display information (e.g., a message) related to the instruction to reload the luggage 4 onto the cart 3. The audio output device of the host device 2 may output audio related to the instruction to reload the luggage 4 onto the cart 3. The host device 2 may transmit information (e.g., a message) related to the instruction to reload the luggage 4 onto the cart 3 to a terminal device that can communicate with the host device 2, and the terminal device may display the information related to the instruction to reload the luggage 4 onto the cart 3.

The worker reloads the luggage 4 onto the cart 3. When the reloading of the luggage 4 onto the cart 3 is complete, the worker uses a terminal device that can communicate with the host device 2 to send a notification of the completion of the reloading of the luggage 4 onto the cart 3 to the host device 2. The worker may also use the input device 202 of the host device 2 to input the notification of the completion of the reloading of the luggage 4 onto the cart 3 to the host device 2. The host device 2 receives the notification of the completion of the reloading of the luggage 4 onto the cart 3 (S78). After processing S78 is performed, the process proceeds to processing S71. Because the luggage 4 has been reloaded onto the cart 3, the host device 2 again sends an instruction to the mobile robot 101 to lift the cart 3.

Third Embodiment
A third embodiment will now be described. In the third embodiment, the same components as those in the first and second embodiments are assigned the same reference numerals as those in the first and second embodiments, and their description will be omitted. Furthermore, since the configuration of the control system according to the third embodiment is similar to that of the control system according to the first embodiment, a detailed description of the configuration of the control system according to the third embodiment will be omitted. The flowchart showing the processing flow in the higher-level device 2 shown in FIG. 15 is applied to the third embodiment. The control systems according to the first to third embodiments may be combined as appropriate.

Figure 21 is a flowchart showing the processing flow in the mobile robot 1 and the host device 2 according to the third embodiment. The processing steps S81 to S84 in the flowchart shown in Figure 21 are the same as the processing steps S1 to S4 in the flowchart shown in Figure 11. The processing steps S85 to S87 in the flowchart shown in Figure 21 are the same as the processing steps S6 to S8 in the flowchart shown in Figure 11. The processing steps S91 to S94 in the flowchart shown in Figure 21 are the same as the processing steps S11 to S14 in the flowchart shown in Figure 11.

The mobile robot 1 lowers the raised dolly 3 (S88). The mobile robot 1 also notifies the host device 2 that the dolly 3 has been lowered. The host device 2 requests the worker to move the dolly 3 (S89). The request to move the dolly 3 is a notification, voice, or the like requesting that the dolly 3 be moved. The display device of the host device 2 may display information (e.g., a message) related to the request to move the dolly 3. The audio output device of the host device 2 may output voice related to the request to move the dolly 3. The host device 2 may send information (e.g., a message) related to the request to move the dolly 3 to a terminal device that can communicate with the host device 2, and the terminal device may display the information related to the request to move the dolly 3.

The integrated control unit 11 may issue a request to the worker to move the cart 3. The integrated control unit 11 is an example of a request unit. The integrated control unit 11 may display information (e.g., a message) related to the request to move the cart 3 on a display device of the mobile robot 1. The integrated control unit 11 may output audio related to the request to move the cart 3 via an audio output device of the mobile robot 1. The integrated control unit 11 may send information (e.g., a message) related to the request to move the cart 3 to a terminal device that can communicate with the mobile robot 1, and the terminal device may display the information related to the request to move the cart 3.

The request to move the dolly 3 may include a request to move the dolly 3 so that the center of gravity of the mobile robot 1 and the center of gravity of the dolly 3 are in a predetermined positional relationship. The predetermined positional relationship may include a predetermined area including the center of gravity of the mobile robot 1 overlapping the center of gravity of the dolly 3 in the vertical direction. In this case, the worker moves the dolly 3 so that the predetermined area including the center of gravity of the dolly 3 and the center of gravity of the mobile robot 1 overlap in the vertical direction. The predetermined positional relationship may include a predetermined area including the center of gravity of the mobile robot 1 overlapping the center of gravity of the dolly 3 in the vertical direction. In this case, the worker moves the dolly 3 so that the center of gravity of the mobile robot 1 overlaps the predetermined area including the center of gravity of the dolly 3 in the vertical direction. The predetermined positional relationship may include a predetermined area including the center of gravity of the mobile robot 1 overlapping the center of gravity of the dolly 3 in the vertical direction. In this case, the worker moves the cart 3 so that the center of gravity of the mobile robot 1 and the center of gravity of the cart 3 overlap in the vertical direction.

The integrated control unit 11 may determine whether the center of gravity of the mobile robot 1 and the center of gravity of the cart 3 are in a predetermined positional relationship. If the center of gravity of the mobile robot 1 and the center of gravity of the cart 3 are not in a predetermined positional relationship, the integrated control unit 11 may request the worker to move the cart 3 again. The higher-level device 2 may also request the worker to move the cart 3 again.

The worker notifies the host device 2 that the movement of the cart 3 is complete (S90). The worker may use the input device 202 of the host device 2 to input a notification to the host device 2 indicating that the movement of the cart 3 is complete. The worker may use a terminal device that can communicate with the host device 2 to send a notification to the host device 2 indicating that the movement of the cart 3 is complete. The host device 2 sends a notification to the mobile robot 1 indicating that the movement of the cart 3 is complete.

The worker may also notify the mobile robot 1 that the movement of the cart 3 is complete. The worker may use an input device on the mobile robot 1 to input a notification to the mobile robot 1 indicating that the movement of the cart 3 is complete. The worker may also use a terminal device capable of communicating with the mobile robot 1 to send a notification to the mobile robot 1 indicating that the movement of the cart 3 is complete. After processing S90 is performed, the process proceeds to processing S83. The processes described above may also be considered as methods for controlling the mobile robot 1.

Before transporting the dolly 3, the dolly 3 is moved so that the center of gravity of the mobile robot 1 and the center of gravity of the dolly 3 are aligned in a predetermined positional relationship. Then, once the center of gravity of the mobile robot 1 and the center of gravity of the dolly 3 are aligned in a predetermined positional relationship, the integrated control unit 11 controls the lifting mechanism 17 to lift the dolly 3. This prevents vibrations and tipping of the dolly 3 when the mobile robot 1 transports the dolly 3, allowing the mobile robot 1 to transport the dolly 3 stably. The dolly 3 may also be moved so that the center of gravity of the mobile robot 1 and the center of gravity of the dolly 3 overlap vertically. Then, once the center of gravity of the mobile robot 1 and the center of gravity of the dolly 3 are aligned vertically, the integrated control unit 11 controls the lifting mechanism 17 to lift the dolly 3. This allows the mobile robot 1 to transport the dolly 3 stably and prevents tire wear on one side of the mobile robot 1's tires.

<Additional Notes>
A self-propelled transport device (1),
a traveling unit (15) that travels the self-propelled transport device (1);
a plurality of pins (18) provided with sensors (20) for measuring load;
a lifting mechanism (17) capable of lifting and lowering the plurality of pins (18);
a control unit (11) that controls the lifting mechanism (17) and acquires load data measured by the sensor (20) when the pins (18) rise and lift the cart (3) carrying at least one load (4) while contacting the bottom surface of the cart (3);
a memory unit (16) that stores the center of gravity position of the self-propelled transport device (1);
Equipped with
The control unit (11) calculates the center of gravity position of the carriage (3) based on the load data, and controls the lifting mechanism (17) to lift the carriage (3) in a state where the center of gravity position of the self-propelled transport device (1) and the center of gravity position of the carriage (3) are in a predetermined positional relationship.
Self-propelled transport device (1).

1, 101: Mobile robot 2; Host device 3; Cart 4; Luggage 11, 111; Integrated control unit 12, 112; Communication unit 13, 113; Travel control unit 14, 114; Lifting control unit 15, 115; Travel unit 16, 116; Memory unit 17, 117; Lifting mechanism 18, 118; Pin 19, 119; Imaging device 20, 120 Load sensor

Claims (8)

A self-propelled transport device that can travel,
a plurality of pins provided with sensors for measuring loads;
a lifting mechanism capable of raising and lowering the plurality of pins;
a control unit that controls the lifting mechanism and acquires load data measured by the sensor when the pins are raised and the dolly is lifted while contacting the bottom surface of the dolly on which at least one item is loaded;
a storage unit that stores a center of gravity position of the self-propelled transport device;
an imaging device that images the dolly and the at least one piece of luggage;
Equipped with
the imaging device generates image data of the dolly and the at least one piece of luggage;
the control unit acquires the load state of the luggage on the dolly from the image data, and determines a position where the self-propelled conveying device will slide under a bottom surface of the dolly based on the load state of the luggage;
the control unit calculates a center of gravity position of the carriage based on the load data, and controls the lifting mechanism to lift the carriage in a state where the center of gravity position of the self-propelled transport device and the center of gravity position of the carriage are in a predetermined positional relationship.
Self-propelled transport device. the predetermined positional relationship includes a predetermined region including a center of gravity of the self-propelled transport device and a center of gravity of the carriage overlapping in the vertical direction.
The self-propelled transport device according to claim 1. the predetermined positional relationship includes a position of a center of gravity of the self-propelled transport device and a predetermined region including a position of a center of gravity of the carriage overlapping in the vertical direction.
The self-propelled transport device according to claim 1. the predetermined positional relationship includes a state in which the center of gravity of the self-propelled transport device and the center of gravity of the carriage overlap in the vertical direction.
The self-propelled transport device according to claim 1. the control unit adjusts at least one of a traveling speed and a turning radius of the self-propelled transport device when there is a change in the position of the center of gravity of the carriage while the self-propelled transport device is traveling.
The self-propelled transport device according to any one of claims 1 to 4. the control unit moves the self-propelled transporting device so that the center of gravity of the self-propelled transporting device and the center of gravity of the carriage are in the predetermined positional relationship.
The self-propelled transport device according to any one of claims 1 to 5. a request unit that requests an operator to move the cart so that the center of gravity of the self-propelled transport device and the center of gravity of the cart are in the predetermined positional relationship;
The self-propelled transport device according to any one of claims 1 to 6. The plurality of pins is three or more.
The self-propelled transport device according to any one of claims 1 to 7 .