JP7724967B2 - Conveying device and conveying method - Google Patents

Description

This disclosure relates to a conveying device and a conveying method for transporting carts containing items.

Carts for storing items are equipped with a front frame, a rear frame facing the front frame, a center frame connecting the front and rear frames, and multiple casters attached to the bottom mechanism, and are used in a variety of situations. Recently, to save labor, the method of moving carts has evolved from manual to automatic.

Various technologies for automatically moving carts have been developed. For example, a technology has been disclosed in which a cart is moved while its center frame is clamped between holding arms (see, for example, Patent Document 1).

WO 2005/105620

The method of fixing the center frame with a holding arm, as disclosed in Patent Document 1, can transport the cart without any problems as long as the floor surface on which the transport device that transports the cart runs is horizontal.

On the other hand, there is a demand for automatic transport of carts in facilities with a mixture of horizontal floors and sloped floors that are inclined relative to the horizontal floors. In such cases, when a transport device for transporting a cart travels on a sloped floor that is inclined at an angle of less than 180 degrees from the horizontal floor, the casters on the front and rear of the cart come into contact with the floor, but the drive wheels of the transport device float above the floor, creating a problem in that the cart cannot be transported.

In addition, when the transport device that transports the cart travels on a sloped floor surface that has an inclination angle of more than 180 degrees with respect to the horizontal floor surface, the drive wheels of the transport device come into contact with the floor surface, but one or both of the casters on the front and rear of the cart may float off the floor surface, causing the cart to become unstable.

This disclosure has been made to solve such problems and aims to provide a transport device and transport method that can transport carts in facilities with a mixture of horizontal and sloping floor surfaces.

In order to solve the above problems, the transport device according to the present disclosure is a transport device for transporting a cart having a front frame, a rear frame facing the front frame, a center frame connecting the front frame and the rear frame, connecting fittings attached to the center frame so as to protrude in a direction different from the extending direction of the center frame, and a plurality of casters, and the transport device comprises a main body mechanism for supporting the entire transport device, a device drive unit attached to the main body mechanism for driving the transport device, a guide mechanism having a shape that can be fitted into a cart fitting unit formed by the center frame and the connecting fittings, and a drive unit for driving the guide mechanism in the height direction. The conveying device is provided with a guide mechanism drive unit that drives the conveying device, a group of sensors that detect the surrounding conditions of the conveying device, and a control unit that controls the device drive unit and the guide mechanism drive unit, and the control unit controls the device drive unit and the guide mechanism drive unit based on the detection results of the group of sensors so that the guide mechanism fits into the cart fitting portion, and when the guide mechanism fits into the cart fitting portion , a predetermined gap exists between the cart fitting portion and the guide mechanism, the cart fitting portion is configured with a center frame and a connecting fitting that are perpendicular to each other, and the guide mechanism is configured with a center frame groove that can fit into the center frame and a connecting fitting groove that can fit into the connecting fitting .

This disclosure makes it possible to transport carts in facilities with a mixture of horizontal and sloping floor surfaces.

The objects, features, aspects, and advantages of the present disclosure will become more apparent from the following detailed description and accompanying drawings.

1 is a block diagram showing an example of the configuration of a transport device according to a first embodiment; 1 is a block diagram showing an example of the configuration of a transport device according to a first embodiment; FIG. 2 is a diagram showing an example of the configuration of a cart according to the first embodiment. 1 is a diagram showing the appearance of a transport device according to a first embodiment; 4A and 4B are diagrams illustrating an example of a configuration of a cart fitting portion according to the first embodiment. 1 is a diagram showing the appearance of a cart fitting portion according to the first embodiment; FIG. 2 is a plan view showing an example of a guide mechanism according to the first embodiment. FIG. 8 is a front view of the guide mechanism shown in FIG. 7 . FIG. 8 is a side view of the guide mechanism shown in FIG. 7 . 8 is a cross-sectional view of the guide mechanism shown in FIG. 7 taken along the line A1-A1. 8 is a cross-sectional view of the guide mechanism shown in FIG. 7 taken along line A2-A2. 8 is a cross-sectional view of the guide mechanism shown in FIG. 7 taken along line A3-A3. 3A and 3B are diagrams illustrating a configuration of a guide mechanism according to the first embodiment. 10 is a plan view showing a state in which the cart fitting portion and the guide mechanism according to the first embodiment are fitted together; FIG. FIG. 15 is a front view of the cart fitting portion and the guide mechanism shown in FIG. 14 . 15 is a cross-sectional view of the cart fitting portion and the guide mechanism shown in FIG. 14 taken along line B2-B2. 15 is a cross-sectional view of the cart fitting portion and the guide mechanism shown in FIG. 14 taken along B1-B1. 10A and 10B are diagrams for explaining the allowable angle of elevation between the center frame and the center frame groove according to the first embodiment. FIG. 2 is a plan view showing an example of a main body mechanism according to the first embodiment. 1 is a side view showing an example of a conveying device in a normal height state according to embodiment 1. FIG. 1 is a side view showing an example of a conveying device in a low-floor state according to Embodiment 1. FIG. 4 is a flowchart showing an example of an operation of the transport device according to the first embodiment. 5A and 5B are diagrams for explaining the movement of the transport device according to the first embodiment. 5A and 5B are diagrams for explaining the movement of the transport device according to the first embodiment. 5A and 5B are diagrams for explaining the movement of the transport device according to the first embodiment. 5A and 5B are diagrams for explaining the movement of the transport device according to the first embodiment. 1A and 1B are diagrams for explaining problems with a conventional conveying device. 1A and 1B are diagrams for explaining problems with a conventional conveying device. 10A and 10B are diagrams for explaining the effect of the transport device according to the first embodiment. 10A and 10B are diagrams for explaining the effect of the transport device according to the first embodiment. 10A and 10B are plan views showing examples of guide mechanisms according to first and second modified examples of the first embodiment. FIG. 32 is a side view of the guide mechanism shown in FIG. 31 . 32A and 32B are cross-sectional views of the guide mechanism shown in FIG. 31 along C2-C2 and C3-C3. 32 is a cross-sectional view of the guide mechanism shown in FIG. 31 taken along C1-C1. FIG. 11 is a cross-sectional view showing an example of a guide mechanism according to a third modification of the first embodiment. FIG. 13 is a plan view showing an example of a guide mechanism according to a fourth modification of the first embodiment. FIG. 37 is a front view of the guide mechanism shown in FIG. 36 . 37 is a cross-sectional view of the guide mechanism shown in FIG. 36 taken along line D1-D1. FIG. 13 is a plan view showing an example of a guide mechanism according to a fifth modification of the first embodiment. FIG. 13 is a block diagram showing an example of the configuration of a transport device according to a seventh modification of the first embodiment. FIG. 13 is a cross-sectional view showing an example of a configuration in which a sensor is provided in a guide mechanism according to an eighth modification of the first embodiment. FIG. 13 is a cross-sectional view showing an example of a configuration in which a sensor is provided in a guide mechanism according to an eighth modification of the first embodiment. FIG. 10 is a block diagram showing an example of the configuration of a transport device according to a second embodiment. 10 is a flowchart showing an example of the operation of the transport device according to the second embodiment. 10 is a diagram showing a bumper mechanism in a stored state according to a second embodiment. FIG. 10 is a diagram showing a bumper mechanism in a protruding state according to a second embodiment. FIG. 10 is a diagram showing a bumper mechanism in a protruding state according to a second embodiment. FIG. FIG. 10 is a block diagram showing an example of the configuration of a transport device according to a first modification of the second embodiment. FIG. 10 is a diagram illustrating a contact sensor according to a first modification of the second embodiment. FIG. 10 is a block diagram showing an example of the configuration of a transport device according to a second modification of the second embodiment. FIG. 10 is a diagram illustrating a magnetic sensor according to a second modification of the second embodiment. FIG. 11 is a block diagram showing an example of the configuration of a transport device according to a third embodiment. 11 is a flowchart showing an example of the operation of the transport device according to the third embodiment. 10A and 10B are diagrams for explaining the storage status of a cart according to the third embodiment. FIG. 11 is a diagram for explaining the state of cart removal according to the third embodiment. FIG. 11 is a diagram for explaining the state of cart removal according to the third embodiment. FIG. 11 is a diagram for explaining the state of cart removal according to the third embodiment. FIG. 11 is a diagram for explaining the state of cart removal according to the third embodiment. FIG. 11 is a diagram for explaining the state of cart removal according to the third embodiment. FIG. 11 is a diagram for explaining the state of cart removal according to the third embodiment. FIG. 10 is a diagram for explaining the state of cart removal according to the first modification of the third embodiment. FIG. 13 is a block diagram showing an example of the configuration of a transport device according to a second modification of the third embodiment. 13A and 13B are diagrams showing a hook mechanism in a stored state according to a second modification of the third embodiment; FIG. 13 is a diagram showing a hook mechanism in an extended state according to a second modification of the third embodiment. FIG. 1 is a diagram illustrating an example of a hardware configuration of a transport device according to first to third embodiments. FIG. 1 is a diagram illustrating an example of a hardware configuration of a transport device according to first to third embodiments.

First Embodiment
<Configuration>
FIG. 1 is a block diagram showing an example of the configuration of a conveyance device 1 according to the first embodiment.

The conveying device 1 comprises a main mechanism 2 and a guide mechanism 4. The main mechanism 2 comprises a device drive unit 3, a guide mechanism drive unit 5, a sensor group 6, and a control unit 7.

The guide mechanism 4 has a shape that can be fitted into the cart fitting portion consisting of the front frame 16 and connecting fitting 23 that make up the cart described below.

The main body mechanism 2 supports the entire conveying device 1. The device drive unit 3 drives the conveying device 1. The guide mechanism drive unit 5 drives the guide mechanism 4 in the vertical direction. The sensor group 6 detects the surrounding conditions of the conveying device 1. Based on the detection results of the sensor group 6, the control unit 7 controls the device drive unit 3 and the guide mechanism drive unit 5 so that the guide mechanism 4 fits into the cart fitting portion. When the guide mechanism 4 fits into the cart fitting portion, a predetermined gap exists between the cart fitting portion and the guide mechanism 4.

Next, we will explain other configurations of the transport device, including the transport device 1 shown in Figure 1, and the cart transported by the transport device. Figure 2 is a block diagram showing an example of the configuration of the transport device 8 relating to another configuration. Also, Figure 3 is a diagram showing an example of the configuration of the cart transported by the transport device 8. Below, we will first explain the configuration of the cart, and then explain the configuration of the transport device 8.

<Cart configuration>
As shown in FIG. 3, the cart includes a front frame 16 , a rear frame 17 , a center frame 18 , casters 19 , caster brakes 20 , a support frame 21 , and a tray 22 .

The front frame 16 is a frame provided at the front of the cart. The rear frame 17 is a frame provided at the rear of the cart opposite the front frame 16. The center frame 18 is a frame that connects the front frame 16 and the rear frame 17. The connecting fittings 23 are provided on the center frame 18 so as to protrude in a direction different from the extension direction of the center frame 18. Details of the connecting fittings 23 will be described later.

One caster 19 is provided on each of the left and right ends of the front frame 16, and one on each of the left and right ends of the rear frame 17. The caster brakes 20 are used to lock the casters 19 in place, and the user can operate the caster brakes 20 to lock the casters 19 and prevent the cart from moving.

The support frame 21 is mounted vertically on each of the front frame 16 and the rear frame 17. The tray 22 is placed on the support frame 21, and items can be placed on the tray 22.

In the example shown in Figure 3, two trays 22 are placed, but the number of trays 22 is not limited to this. Furthermore, the center frame 18 may be structured to protrude from both or either the front frame 16 and the rear frame 17.

<Configuration of the conveying device>
2 , the transport device 8 includes a guide mechanism 4, a main body mechanism 9, casters 13, and drive wheels 14. The main body mechanism 9 includes a device drive unit 3, a guide mechanism drive unit 5, a sensor group 6, a control unit 7, and a communication unit 12.

The sensor group 6 includes a lidar 10 and a depth camera 11. The sensor group 6 also detects each part that makes up the cart.

Lidar 10 detects obstacles in the space surrounding the conveying device 8 and detects its own position for SLAM (Simultaneous Localization and Mapping) driving.

The depth camera 11 photographs the area around the transport device 8 to obtain a distance image, and performs image processing on the obtained distance image to determine the distance to obstacles present around the transport device 8. The range of the depth camera 11 is approximately 10 cm. The depth cameras 11 are installed, for example, one at each of the four corners of the transport device 8 (four in total), one facing downward at the front and rear of the transport device 8 (two in total), and one facing upward at the front and rear of the transport device 8 (two in total). The depth cameras 11 installed at the four corners of the transport device 8 are used to detect obstacles present diagonally as viewed from the transport device 8. The depth cameras 11 installed one at the front and one at the rear of the transport device 8 facing downward are used for precise guidance of the transport device 8, for detecting obstacles present in front of the transport device 8, and for detecting obstacles present on the floor surface on which the transport device 8 travels. The depth cameras 11, one facing upward and installed at the front and one at the rear of the transport device 8, are used to detect obstacles in front of the transport device 8 and obstacles above the transport device 8. The depth cameras 11 are preferably installed in positions that are symmetrical in the front, back, left, and right directions of the transport device 8. By installing the depth cameras 11 in symmetrical positions, obstacles present around the transport device 8 can be detected by performing the same image processing, eliminating the need to develop multiple software detection logics. Convolutional Neural Networks (CNNs) may be used to detect obstacles present around the transport device 8.

The guide mechanism drive unit 5 drives the guide mechanism 4 to change the height of the guide mechanism 4 from the floor. Details of the guide mechanism 4 will be described later.

The control unit 7 controls the entire conveying device 8, including the device drive unit 3 and the guide mechanism drive unit 5.

The communication unit 12 communicates with an instruction center 15 located outside the transport device 8. The instruction center 15 monitors the transport device 8 and instructs the transport device 8 to transport the cart.

Figure 4 shows the external appearance of the conveying device 8. Casters 13 are provided at the four corners of the main body mechanism 9.

The device drive unit 3 is a motor that rotates and drives the drive wheels 14 in accordance with instructions from the control unit 7. One drive wheel 14 is provided on each side of the main mechanism 9. A device drive unit 3 may also be provided for each drive wheel 14. In the example shown in Figure 3, the drive wheels 14 are wheels, but they may also be other forms of movement such as caterpillar tracks. In addition, the drive wheels 14 are not limited to being provided in pairs on the left and right sides of the main mechanism 9, and may be provided in any configuration, such as multiple pairs.

<Configuration of Cart Fitting Portion>
Fig. 5 is a diagram showing an example of the configuration of the cart fitting section 24. Fig. 6 is a diagram showing the external appearance of the cart fitting section 24.

As shown in Figure 5, the cart fitting portion 24 has a cross-shaped configuration in which the center frame 18 and the connecting fitting 23 are perpendicular to each other.

As shown in Figure 6, the connecting fittings 23 are attached to both sides of the center frame 18 using mounting brackets. By using the mounting brackets, it is possible to firmly secure the connecting fittings 23 to the center frame 18 without modifying the cart. Alternatively, holes may be drilled in the center frame 18 and the connecting fittings 23 may be screwed to the center frame 18.

<Configuration of guide mechanism>
Fig. 7 is a plan view showing an example of the guide mechanism 4. Fig. 8 is a front view of the guide mechanism 4 shown in Fig. 7 (as seen from the right side of Fig. 7), Fig. 9 is a side view of the guide mechanism 4 shown in Fig. 7, Fig. 10 is a cross-sectional view of the guide mechanism shown in Fig. 7 taken along A1-A1, Fig. 11 is a cross-sectional view of the guide mechanism shown in Fig. 7 taken along A2-A2, and Fig. 12 is a cross-sectional view of the guide mechanism shown in Fig. 7 taken along A3-A3. Fig. 13 is a diagram showing the configuration of the guide mechanism 4. The guide mechanism 4 is provided on top of the main body mechanism 9.

As shown in Figures 7 to 13, the guide mechanism 4 has a concave center frame groove 25 in the longitudinal direction that can mate with the cart's center frame 18, and a concave connecting fitting groove 26 in the lateral direction that can mate with the cart's connecting fitting 23. Thus, the guide mechanism 4 has a cross shape in which the center frame groove 25 and the connecting fitting groove 26 are perpendicular to each other, allowing it to mate with the cart fitting portion 24.

<Engagement of cart fitting portion and guide mechanism>
Fig. 14 is a plan view showing a state in which the cart fitting portion 24 is fitted into the guide mechanism 4. Fig. 15 is a front view (viewed from the right side of Fig. 14) of the cart fitting portion 24 and the guide mechanism 4 shown in Fig. 14, Fig. 16 is a B2-B2 cross-sectional view of the cart fitting portion 24 and the guide mechanism 4 shown in Fig. 14, and Fig. 17 is a B1-B1 cross-sectional view of the cart fitting portion 24 and the guide mechanism 4 shown in Fig. 14.

As described above, the cart fitting portion 24 is composed of the center frame 18 and the connecting fitting 23. As shown in Figures 14 to 17, the guide mechanism 4 fits into the cart fitting portion 24 of the cart.

Figure 18 is a diagram illustrating the allowable elevation angle α between the center frame 18 and the center frame groove 25. For example, wheelchair ramps are installed so that the gradient is less than 5%, so if the transport device 8 needs to transport a cart along a wheelchair ramp, the elevation angle α is designed to match the gradient of 5%. Furthermore, if the transport device 8 transporting the cart needs to travel a steeper slope, the allowable elevation angle α is designed to be larger accordingly.

As an example, the cart fitting portion 24 and the guide mechanism 4 may be gently fitted together to allow for a gradient of 5%. In this case, if the cart's longitudinal dimension is 1 m, then at a gradient of 5%, the vertical (height) gap between the cart fitting portion 24 and the guide mechanism 4 may be approximately 2.5 cm. In other words, the depth of each of the center frame grooves 25 and the connecting fitting grooves 26 that make up the guide mechanism 4 may be designed so that the vertical (height) gap between the cart fitting portion 24 and the guide mechanism 4 is approximately 2.5 cm.

<Lifting mechanism>
Fig. 19 is a diagram for explaining the lifting mechanism. Fig. 20 is a side view showing an example of a conveying device in a normal height state. Fig. 21 is a side view showing an example of a conveying device in a low-floor state. Note that although the guide mechanism 4 is not shown in Fig. 19, it is assumed that the guide mechanism 4 is provided integrally with the main body mechanism 9.

The parts surrounded by dashed lines in Figure 19 are lifting motors for raising and lowering the main mechanism 9. This lifting motor corresponds to the guide mechanism drive unit 5. The guide mechanism drive unit 5 presses the drive wheels 14 down from the main mechanism 9 or stores the drive wheels 14 in the main mechanism 9 in accordance with instructions from the control unit 7.

When the guide mechanism drive unit 5 pushes the drive wheel 14 down from the main mechanism 9, the main mechanism 9 is accordingly pushed up from the floor surface to its normal height. At this time, the position of the guide mechanism 4, which is configured integrally with the main mechanism 9, also rises to its normal height.

On the other hand, when the drive wheels 14 are stored in the main body mechanism 9 by the guide mechanism drive unit 5, the main body mechanism 9 is accordingly placed in a low-floor state lower than its normal height. At this time, the position of the guide mechanism 4, which is configured integrally with the main body mechanism 9, is also lowered, placing it in a low-floor state.

In the example of Figure 19, lifting motors located on the left and right sides of the transport device 8 are used to lift and lower components other than the drive wheels 14 and casters 13. The posture is maintained by the holding force of the electromagnetic brakes (non-excitation type) that make up the lifting motors and the worm gears used for lifting drive. Note that the lifting mechanism is not limited to the example of Figure 19, and may be realized using hydraulic or other mechanisms.

Furthermore, if the height of the Lidar 10 is higher than the center frame 18 of the cart when the transport device 8 is in a low-floor state, there is a possibility that the Lidar 10 will collide with the center frame 18. To address this, the transport device 8 is provided with a Lidar lifting mechanism (the area surrounded by dashed lines in Figures 20 and 21) that lowers the Lidar 10 in conjunction with the low-floor state. In embodiment 1, the Lidar 10 is installed in two locations, one on the left and one on the right side of the transport device 8, and used at a high position to cover a 360-degree detection range; however, if the Lidar is configured to be used at a low position, a mechanism to lower the Lidar that is in a high position is not required.

<Operation>
Below, we will explain how the conveying device 8 waits at a predetermined waiting position Prest inside the building, and when it receives an instruction from the instruction center 15, it detects a cart stopped at point Pa and transports the cart to destination Pb.

The control unit 7 is equipped with a SoC (System On a Chip) and has a built-in program that causes the entire conveying device 8 to operate autonomously.

Figure 22 is a flowchart showing an example of the operation of the conveying device 8.

In step S101, the control unit 7 receives a movement command transmitted from the instruction center 15 via the communication unit 12. The movement command is a command indicating that a cart stopped at point Pa should be transported to destination Pb. The movement command includes position information of the cart (position information of point Pa) and position information of the cart's destination (position information of destination Pb).

In step S102, the control unit 7 calculates a route from the waiting position Prest of the transport device 8 to point Pa where the cart is located, based on map information within the building (not shown). Then, based on the surrounding conditions detected by the sensor group 6 including the Lidar 10 and the depth camera 11, the control unit 7 controls the device driving unit 3 to autonomously travel to point Pa while avoiding moving objects or obstacles present around the transport device 8. When the control unit 7 discovers a cart near point Pa, it controls the device driving unit 3 to stop the transport device 8. The transport device 8 travels from the waiting position Prest to point Pa at a normal height (see Figure 20).

Here, we have described the case where the control unit 7 calculates the route from the standby position Prest to point Pa, but this is not limited to this. The instruction center 15 may also calculate the route from the standby position Prest to point Pa and notify the conveying device 8.

Map information within the building may be stored by the control unit 7, or may be obtained from an external source such as the instruction center 15 if necessary.

In step S103, the control unit 7 formulates a movement plan for moving the transport device 8 into the cart. Then, based on the formulated movement plan and the surrounding conditions detected by the Lidar 10 and the depth camera 11, the control unit 7 controls the device driving unit 3 so that the transport device 8 moves into the cart. Figures 23 and 24 show the transport device 8 moving into the cart. At this time, the transport device 8 moves into the cart after reaching a low-floor state (see Figure 21).

In step S104, the control unit 7 controls the device driving unit 3 so that the shape of the guide mechanism 4 matches the shape of the cart fitting portion 24 based on the position of the cart fitting portion 24 detected by the Lidar 10 and the depth camera 11. Figure 25 shows the state after the conveying device 8 has rotated so that the shape of the guide mechanism 4 matches the shape of the cart fitting portion 24.

In step S105, the control unit 7 controls the guide mechanism drive unit 5 so that the conveying device 8 is at its normal height. When the conveying device 8 is at its normal height, the cart fitting portion 24 and the guide mechanism 4 are loosely fitted together.

In step S106, the control unit 7 calculates a route from point Pa to destination Pb based on map information inside the building (not shown). Then, based on the surrounding conditions detected by the Lidar 10 and the depth camera 11, the control unit 7 controls the device drive unit 3 to autonomously travel to destination Pb while avoiding moving objects or obstacles present around the transport device 8. As a result, the cart is transported from point Pa to destination Pb. Figure 26 shows how the transport device 8 transports the cart.

Here, we have described the case where the control unit 7 calculates the route from point Pa to destination Pb, but this is not limited to this. The instruction center 15 may also calculate the route from point Pa to destination Pb and notify the conveying device 8.

When the cart arrives at destination Pb, staff inside the building collect the items placed on the cart's tray 22. The control unit 7 of the conveying device 8 then receives a command from the instruction center 15 via the communication unit 12 to return to the standby position Prest, and controls the device drive unit 3 to autonomously travel from destination Pb to standby position Pret. Alternatively, the movement command received by the control unit 7 from the instruction center 15 in step S101 may include a command to autonomously travel to standby position Pret after the conveying device 8 arrives at destination Pb.

Uses of the conveying device 8 include, for example, delivering medicine or food within a hospital, delivering food in a school, delivering food or goods in an office, or transporting parts within a manufacturing plant.

<Effects>
In conventional transport devices, the cart and the transport device are firmly fixed together, which can lead to situations where the drive wheels of the transport device float up on an upslope, making it impossible to transport the cart, as shown in Figure 27, or where the casters of the cart float up on a downslope, making the cart unstable, as shown in Figure 28.

In contrast, in the transport device 8 according to embodiment 1, the guide mechanism 4 and the cart fitting 24 are configured to fit loosely, allowing for variations in the height gap between the guide mechanism 4 and the cart's connecting fitting 23 and for differences in the elevation angle between the guide mechanism 4's center frame groove 25 and the cart's center frame 18. Therefore, on an upward slope, as shown in FIG. 29, the height gap between the guide mechanism 4 and the cart's connecting fitting 23 is longer, allowing for differences in the elevation angle, so the drive wheels 14 of the transport device 8 do not float. On a downward slope, as shown in FIG. 30, the height gap between the guide mechanism 4 and the cart's connecting fitting 23 is shorter, allowing for differences in the elevation angle, so the cart's casters 19 do not float. In this way, the transport device 8 according to embodiment 1 enables stable transport of carts in facilities with a mixture of horizontal and sloping floors.

<First Modification of First Embodiment>
The shape of the guide mechanism 4 is not limited to the shape shown in Figures 7 to 12, and may be any shape as long as it functionally has a center frame groove 25 and a connecting fitting groove 26.

For example, as shown in Figures 31 to 34, the guide mechanism 4 may be composed of four protruding mechanisms 27 to 30 provided on the top of the main mechanism 9. Note that Figure 32 is a side view of the guide mechanism 4 shown in Figure 31, Figure 33 is a C2-C2 and C3-C3 cross-sectional view of the guide mechanism 4 shown in Figure 31, and Figure 34 is a C1-C1 cross-sectional view of the guide mechanism 4 shown in Figure 31.

As shown in Figures 31 and 34, the groove sandwiched between convex mechanisms 27 and 29, and the groove sandwiched between convex mechanisms 28 and 30, form center frame groove 25. Also, as shown in Figures 31 and 32, the groove sandwiched between convex mechanisms 27 and 28, and the groove sandwiched between convex mechanisms 29 and 30, form connecting fitting groove 26.

<Second Modification of First Embodiment>
31 to 34, the distance d between the convex mechanism 27 and the convex mechanism 29 and the distance d between the convex mechanism 28 and the convex mechanism 30 may be configured to change by a specific mechanism drive unit (not shown). In this case, either the convex mechanisms 27 and 28 or the convex mechanisms 29 and 30 may move, or all of the convex mechanisms 27 to 30 may move.

This allows carts with different widths (thicknesses) of the center frame 18 to be transported by the conveying device 8.

<Third Modification of First Embodiment>
The convex mechanisms 27 to 30 shown in Figures 31 to 34 may have a tapered shape as shown in Figure 35. In Figure 35, the convex mechanisms 28 and 30 are shown to have a tapered shape, but the convex mechanisms 27 and 29 also have a similar tapered shape.

Note that Figure 35 shows a case where the convex mechanisms 27-30 that make up the center frame groove 25 have a tapered shape, but the convex mechanisms 27-30 that make up the connecting fitting groove 26 may also have a tapered shape. Furthermore, the center frame groove 25 and the connecting fitting groove 26 shown in Figures 7-12 may also have a tapered shape.

<Fourth Modification of First Embodiment>
There are various types of cart undercarriage structures (front frame 16, rear frame 17, and center frame 18). In the example of Fig. 3, the front frame 16 and rear frame 17 form the short axis, and the center of the front frame 16 and the center of the rear frame 17 are fixed by the long axis of the center frame 18, but other structures are also possible.

For example, as shown in Figures 36 to 38, two center frame grooves 25 may be provided. In this case, even a cart having two center frames 18 can be transported.

Note that Figure 37 is a front view of the guide mechanism 4 shown in Figure 36 (viewed from the right side of Figure 36), and Figure 38 is a D1-D1 cross-sectional view of the guide mechanism 4 shown in Figure 36.

<Fifth Modification of First Embodiment>
To transport a cart having two center frames 18 as described in Modification 4, as shown in Figure 39, protruding mechanisms 27-30 as in Modification 1 may be provided to make the lateral distance D variable. In this case, the distance D may be changed so that the center frame groove 25 fits into one of the center frames 18 after the transport device 8 slides into the cart.

The distance D may be changed by moving either the convex mechanisms 27, 28 or the convex mechanisms 29, 30, or by moving all of the convex mechanisms 27 to 30.

<Sixth Modification of First Embodiment>
In the first embodiment, the cart fitting portion 24 is described as having a cross shape in which the center frame 18 and the connecting fitting 23 intersect at a 90-degree angle, but the shape of the cart fitting portion 24 is not limited to this. For example, the shape of the connecting fitting 23 may be any shape, such as a curved shape, a shape in which the cart fitting portion 24 is X-shaped, or a shape in which the cart fitting portion 24 is V-shaped.

Furthermore, the shape of the guide mechanism 4 may be any shape that can be fitted into the cart fitting portion 24.

<Seventh Modification of First Embodiment>
In the first embodiment, the main body mechanism 9 and the guide mechanism 4 are configured as a single unit as shown in FIG. 2, and the drive wheels 14 are pushed down from the main body mechanism 9 to raise the main body mechanism 9 and the guide mechanism 4 from the floor surface. However, the configuration for adjusting the height of the guide mechanism 4 is not limited to this.

For example, as shown in Figure 40, the conveying device 31 may be provided with a separate guide mechanism 4 and a main body mechanism 32, and the height of the guide mechanism 4 may be adjusted by the guide mechanism drive unit 5 driving the guide mechanism 4 to lift it from the main body mechanism 32.

Eighth Modification of First Embodiment
A sensor for checking the presence or absence of the center frame 18 may be provided on the lower surface (bottom surface of the recess) of the center frame groove 25 that constitutes the guide mechanism 4.

Figures 41 and 42 show an example of a configuration in which a sensor 33 is provided in the center frame groove 25. Figure 41 shows a state in which the center frame groove 25 is not engaged with the center frame 18. Figure 42 shows a state in which the center frame groove 25 is engaged with the center frame 18.

The sensor 33 detects whether the center frame 18 is present above the guide mechanism 4 and whether the center frame groove 25 is properly fitted into the center frame 18. Examples of the sensor 33 include a set of an infrared laser and a light-receiving element, or a magnetic sensor.

<Ninth Modification of First Embodiment>
In the first embodiment, the description is given assuming that the transport device 8 transports a cart in a place on the same floor of a building where there is no door, etc. However, the transport device 8 can also transport a cart in a place where there is a door, or transport a cart to another floor using an elevator.

For example, the command center 15 is configured to have the function of controlling the opening and closing of elevators and doors installed within the building and monitoring the status of the conveying device 8. The command center 15 may then control the opening and closing of doors, the opening and closing of elevators, or the raising and lowering of elevators in accordance with the movement of the conveying device 8, allowing the conveying device 8 to travel autonomously to the destination. Alternatively, the control unit 7 of the conveying device 8 may communicate with the elevator control unit and door opening and closing control unit via the communication unit 12, allowing the conveying device 8 to travel autonomously to the destination.

<Second Embodiment>
<Configuration>
FIG. 43 is a block diagram showing an example of the configuration of the transport device 34 according to the second embodiment.

As shown in Figure 43, the conveying device 34 is characterized by having a bumper mechanism 36 and a bumper mechanism drive unit 37. The bumper mechanism drive unit 37 is provided in the main body mechanism 35. The other configurations are the same as those of the conveying device 8 described in embodiment 1, so detailed explanations will be omitted here.

The bumper mechanism 36 is an extendable mechanism that protrudes outward at least beyond the front frame 16 and the rear frame 17. If a situation arises in which the transport device 34 comes into contact with an obstacle while transporting the cart, the bumper mechanism 36 will come into contact with the obstacle before the cart.

The bumper mechanism drive unit 37 drives the bumper mechanism 36 to slide so that the bumper mechanism 36 extends to a position that protrudes outward at least beyond the front frame 16 and the rear frame 17.

As in embodiment 1, the depth cameras 11 are installed, for example, one at each of the four corners of the conveying device 34 (four in total), one facing downward at the front and rear of the conveying device 34 (two in total), and one facing upward at the front and rear of the conveying device 34 (two in total).

<Operation>
Fig. 44 is a flowchart showing an example of the operation of the transport device 34. Steps S201 to S205 and step S207 in Fig. 44 are similar to steps S101 to S105 and step S106 in Fig. 22 described in embodiment 1, and therefore will not be described here. Step S206 will be described below.

In step S206, the control unit 7 controls the bumper mechanism drive unit 37 so that the bumper mechanism 36 protrudes from the front frame 16 and rear frame 17 of the cart.

Figure 45 shows the bumper mechanism in a stored state. Figures 46 and 47 show the bumper mechanism in a protruding state. The part surrounded by a dashed line in Figure 47 is the bumper drive motor, which corresponds to the bumper mechanism drive unit 37. The bumper mechanism 36 protrudes outward, for example, by approximately 170 mm, from the initial position of the bumper mechanism 36 shown in Figure 45, as shown in Figures 46 and 47.

In step S207, if the transport device 34 comes into contact with an obstacle while transporting the cart, the bumper mechanism 36 absorbs the impact at the time of contact, thereby reducing the impact on the cart.

<First Modification of Second Embodiment>
FIG. 48 is a block diagram showing an example of the configuration of the transport device 34 according to the first modification of the second embodiment.

As shown in Figure 48, the conveying device 34 according to variant example 1 is characterized by the provision of a contact sensor 38 on the bumper mechanism 36. The rest of the configuration is the same as that of the conveying device 34 described in embodiment 2, so detailed description will be omitted here.

As shown in Figure 49, the contact sensor 38 is provided at the tip of the bumper mechanism 36. The contact sensor 38 is also called a pressure-sensitive sensor or tape switch.

In step S207 of Figure 44, while the transport device 34 is transporting the cart, the control unit 7 detects that the bumper mechanism 36 has come into contact with an obstacle based on the detection result of the contact sensor 38, and stops the transport device 34. At this time, the control unit 7 may transmit a notification that the transport device 34 has been stopped to a predetermined device (e.g., the instruction center 15) via the communication unit 12, may activate an alert notification device (not shown) provided in the transport device 34, or may plan an alternative route that avoids the obstacle and transport the cart along that route.

By providing a contact sensor 38, the conveying device 34 can be effectively operated against obstacles that cannot be detected by the Lidar 10 and depth camera 11.

<Second Modification of Second Embodiment>
FIG. 50 is a block diagram showing an example of the configuration of the transport device 34 according to the second modification of the second embodiment.

As shown in Figure 50, the conveying device 34 according to variant example 2 is characterized by the provision of a magnetic sensor 39 on the bumper mechanism 36. The rest of the configuration is the same as that of the conveying device 34 described in embodiment 2, so detailed description will be omitted here.

As shown in Figure 51, the magnetic sensor 39 is located near the tip of the bumper mechanism. The magnetic sensor 39 is a non-contact peripheral detection sensor that detects the presence of magnetic tape.

For example, magnetic tape may be attached in front of a no-entry area (no-entry marker) where the transport device 34 is prohibited from entering, and when the magnetic sensor 39 (no-entry area detection sensor) detects the magnetic tape, an emergency stop safety system is activated, halting the movement of the transport device 34. At this time, the control unit 7 may transmit a notification that the transport device 34 has stopped to a predetermined device (e.g., the instruction center 15) via the communication unit 12, or may activate an alert notification device (not shown) provided in the transport device 34, or may plan an alternative route that avoids the obstacle and transport the cart along that route.

When a magnetic sensor is provided in the conveying device 8 described in embodiment 1, it may be provided at an appropriate position in front of or behind the main mechanism 9. Furthermore, the magnetic tape need not be positioned just in front of the no-entry area, but may be stretched to define the no-entry area.

<Third Embodiment>
<Configuration>
FIG. 52 is a block diagram showing an example of the configuration of the transport device 40 according to the third embodiment.

As shown in Figure 52, the transport device 40 is characterized by having a hook mechanism drive unit 42 and a hook mechanism 43. The hook mechanism drive unit 42 is provided in the main body mechanism 41. The other configurations are the same as those of the transport device 34 described in embodiment 2, so detailed description will be omitted here.

In addition, the conveying device 40 may be configured to include both or either the contact sensor 38 described in variant example 1 of embodiment 2 and the magnetic sensor 39 described in variant example 2 of embodiment 2.

The hook mechanism drive unit 42 and hook mechanism 43 can also be applied to the conveying device 8 described in embodiment 1.

The hook mechanism 43 is an extendable mechanism that hooks onto the frame (component frame) that constitutes the cart, including the front frame 16, rear frame 17, and center frame 18, in order to pull out the stored cart.

The hook mechanism drive unit 42 drives the hook mechanism 43, causing the hook mechanism 43 to extend and retract between the stored state and the extended state.

<Operation>
Figure 53 is a flowchart showing an example of the operation of the transport device 40. Steps S301, S302, and S308 to S311 in Figure 53 are similar to steps S201, S202, and S204 to S207 in Figure 44 described in embodiment 2, and therefore will not be described here. Steps S303 to S307 will be described below. Note that in Figures 54 to 60 described below, the connecting fittings 23 provided on the cart are not shown.

Figure 54 is a diagram showing an example of the storage status of a cart. As shown in Figure 54, when a transport device transports a stored cart, the transport device cannot rotate or move forward or backward, so the cart cannot be removed. Embodiment 3 is intended to solve this problem. Figure 55 is a diagram showing the positional relationship between the cart and transport device 40 in step S302 of Figure 53.

In step S303, the control unit 7 formulates a movement plan to have the transport device 40 move under the cart and move to a position where the cart can be pulled out. Based on the formulated movement plan and the surrounding conditions detected by the Lidar 10 and the depth camera 11, the control unit 7 controls the device drive unit 3 so that the transport device 40 moves to a position where the cart can be pulled out. Figure 56 shows the transport device 40 moving under the cart. At this time, the transport device 40 moves under the cart after reaching a low-floor state (see Figure 21).

In step S304, the control unit 7 controls the hook mechanism drive unit 42 so that the hook mechanism 43 is in an extended state. The control unit 7 then controls the guide mechanism drive unit 5 so that the conveying device 40 is in a normal height state. Figure 57 shows the hook mechanism 43 in an extended state.

In step S305, the control unit 7 controls the device drive unit 3 to pull out the cart with the hook mechanism 43 hooked onto the center frame 18 of the cart. Figure 58 shows the transport device 40 pulling out the cart.

In step S306, the control unit 7 controls the guide mechanism drive unit 5 so that the conveying device 40 is in a low-floor state. Then, the control unit 7 controls the hook mechanism drive unit 42 so that the hook mechanism 43 is in a stored state. Figure 59 shows the hook mechanism 43 in a stored state.

In step S307, the control unit 7 formulates a movement plan for moving the transport device 40 into the cart. Then, based on the formulated movement plan and the surrounding conditions detected by the Lidar 10 and the depth camera 11, the control unit 7 controls the device driving unit 3 so that the transport device 40 moves into the cart. Figure 60 shows the transport device 40 moving into the cart.

<Effects>
According to the transport device 40 of the third embodiment, even when the cart is stored in the storage space, it is possible to remove the cart and transport it.

<First Modification of Third Embodiment>
In the third embodiment, the hook mechanism 43 is hooked onto the center frame 18 of the cart to remove the item, but the present invention is not limited to this.

For example, when the cart is stored as shown in Figure 61, the hook mechanism 43 can be hooked onto the front frame 16 or rear frame 17 of the cart to remove it.

<Modification 2 of Embodiment 3>
FIG. 62 is a block diagram showing an example of the configuration of the transport device 44 according to the second modification of the third embodiment.

As shown in Figure 62, the transport device 44 is characterized in that a bumper mechanism drive unit 37 drives the bumper mechanism 36 and the hook mechanism 43. The bumper mechanism drive unit 37 is provided in the main body mechanism 45. The other configurations are the same as those of the transport device 40 described in embodiment 3, so detailed explanations will be omitted here.

The bumper mechanism drive unit 37 has the function of the hook mechanism drive unit 42 shown in Figure 52. This allows the number of drive units in the conveying device 44 to be reduced.

Figure 63 shows the hook mechanism in a stored state. Figure 64 shows the hook mechanism in an extended state. The hook mechanism 43 moves in conjunction with the movement of the bumper mechanism 36. The transport device 44 is equipped with a solenoid lock, and by controlling this solenoid lock, the hook mechanism 43 can only be moved when the cart is being pulled out.

<Hardware configuration>
2 are realized by a processing circuit. That is, the conveying device 8 includes a processing circuit for controlling the device driving unit 3 and the guide mechanism driving unit 5 so that the guide mechanism 4 fits into the cart fitting unit 24 based on the detection results of the sensor group 6, and for communicating with an instruction center 15 provided outside the conveying device 8. The processing circuit may be dedicated hardware, or may be a processor (also referred to as a CPU, central processing unit, processing device, arithmetic unit, microprocessor, microcomputer, or DSP (Digital Signal Processor)) that executes a program stored in a memory.

When the processing circuit is dedicated hardware, as shown in Figure 65, the processing circuit 46 may be, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination of these. Each function of the control unit 7 and the communication unit 12 may be realized by a processing circuit 46, or all functions may be realized together by a single processing circuit 46.

When the processing circuit 46 is the processor 47 shown in FIG. 66, the functions of the control unit 7 and communication unit 12 are realized by software, firmware, or a combination of software and firmware. The software or firmware is written as a program and stored in memory 48. The processor 47 realizes each function by reading and executing the program recorded in memory 48. That is, the conveying device 8 includes memory 48 for storing a program that ultimately executes the steps of controlling the device drive unit 3 and the guide mechanism drive unit 5 so that the guide mechanism 4 engages with the cart engagement unit 24 based on the detection results of the sensor group 6, and communicating with an instruction center 15 located outside the conveying device 8. Furthermore, these programs can also be said to cause a computer to execute the procedures or methods of the control unit 7 and communication unit 12. Here, the memory may be, for example, a non-volatile or volatile semiconductor memory such as RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable Read Only Memory), EEPROM (Electrically Erasable Programmable Read Only Memory), a magnetic disk, a flexible disk, an optical disk, a compact disk, a DVD (Digital Versatile Disc), or any storage medium that will be used in the future.

In addition, with regard to the functions of the control unit 7 and the communication unit 12, some functions may be realized by dedicated hardware, and other functions may be realized by software or firmware.

In this way, the processing circuitry can realize each of the above-mentioned functions through hardware, software, firmware, or a combination of these.

Note that while the above describes the hardware configuration of the conveying device 8 shown in Figure 2, the hardware configuration of the conveying device 31 shown in Figure 40, the conveying device 34 shown in Figures 43, 48, and 50, the conveying device 40 shown in Figure 52, and the conveying device 44 shown in Figure 62 is similar.

In addition, within the scope of this disclosure, it is possible to freely combine each embodiment, or to modify or omit each embodiment as appropriate.

Although the present disclosure has been described in detail, the above description is illustrative in all respects and is not limiting. It is understood that countless variations not illustrated can be envisioned.

REFERENCE SIGNS LIST 1 Conveying device, 2 Main body mechanism, 3 Device drive unit, 4 Guide mechanism, 5 Guide mechanism drive unit, 6 Sensor group, 7 Control unit, 8 Conveying device, 9 Main body mechanism, 10 Lidar, 11 Depth camera, 12 Communication unit, 13 Caster, 14 Drive wheel, 15 Indication center, 16 Front frame, 17 Rear frame, 18 Center frame, 19 Caster, 20 Caster brake, 21 Support frame, 22 Tray, 23 Connecting fitting, 24 Cart fitting, 25 Center frame groove, 26 Connecting fitting groove, 27 Convex mechanism, 28 Convex mechanism, 29 Convex mechanism, 30 Convex mechanism, 31 Convex device, 32 Main body mechanism, 33 Sensor, 34 Conveying device, 35 Main body mechanism, 36 Bumper mechanism, 37 Bumper mechanism drive unit, 38 Contact sensor, 39 Magnetic sensor, 40 Conveying device, 41 main body mechanism, 42 hook mechanism drive unit, 43 hook mechanism, 44 conveying device, 45 main body mechanism, 46 processing circuit, 47 processor, 48 memory.

Claims (13)

A transport device for transporting a cart having a front frame, a rear frame facing the front frame, a center frame connecting the front frame and the rear frame, connecting fittings attached to the center frame so as to protrude in a direction different from the extending direction of the center frame, and a plurality of casters,
a main body mechanism that supports the entire conveying device;
a device driving unit provided in the main body mechanism and configured to drive the conveying device;
a guide mechanism having a shape that can be fitted into a cart fitting portion formed by the center frame and the connecting fitting;
a guide mechanism driving unit that drives the guide mechanism in a height direction;
a group of sensors for detecting the surrounding conditions of the conveying device;
a control unit that controls the device drive unit and the guide mechanism drive unit;
Equipped with
the control unit controls the device driving unit and the guide mechanism driving unit based on the detection results of the sensors so that the guide mechanism fits into the cart fitting portion;
When the guide mechanism is fitted into the cart fitting portion, a predetermined gap exists between the cart fitting portion and the guide mechanism ,
The cart fitting portion is configured such that the center frame and the connecting fitting are perpendicular to each other,
The guide mechanism is a conveying device that is composed of a center frame groove that can be fitted onto the center frame and a connecting fitting groove that can be fitted onto the connecting fitting . the transport device further includes a drive wheel that is rotationally driven by the device drive unit;
the guide mechanism is configured integrally with the main body mechanism,
The conveying device described in claim 1, wherein the control unit controls the guide mechanism drive unit to place the main body mechanism and the guide mechanism in a normal height state by causing the drive wheels to protrude from the bottom surface of the main body mechanism, or to place the main body mechanism and the guide mechanism in a low-floor state by storing the drive wheels in the main body mechanism. The conveying device described in claim 1, wherein the control unit controls the guide mechanism drive unit so that the guide mechanism moves above the main body mechanism. a bumper mechanism extendable to a position protruding outward beyond at least the front frame and the rear frame;
a bumper mechanism drive unit that drives the bumper mechanism;
Furthermore,
The transport device according to claim 1 , wherein the control unit controls the bumper mechanism drive unit so that the bumper mechanism slides to a position where it protrudes outward beyond at least the front frame and the rear frame. the bumper mechanism has a contact sensor on the outwardly protruding side;
The transport device according to claim 4 , wherein the control unit controls the device drive unit to stop movement of the transport device when the contact sensor detects contact. the bumper mechanism has a magnetic sensor that detects a magnetic tape that defines a no-entry area of the transport device,
The transport device according to claim 4 , wherein the control unit controls the device drive unit based on a detection result of the magnetic sensor so that the transport device does not enter the no-entry area. the main body mechanism has a no-entry area detection sensor that detects the presence of a no-entry marker that defines a no-entry area of the transport device,
The transport device according to claim 1 , wherein the control unit controls the device drive unit based on a detection result of the no-entry area detection sensor so that the transport device does not enter the no-entry area. Further provided is at least one depth camera for photographing the periphery of the transport device;
The conveying device described in claim 1, wherein the control unit detects obstacles present in the vicinity of the conveying device based on images captured by the depth camera and controls the device drive unit so that the conveying device moves while avoiding the obstacles. A pair of Lidar sensors that detect the surrounding conditions of the transport device;
a lidar lifting mechanism that moves each of the lidars to a position where it protrudes above the main body mechanism when the main body mechanism is in the normal height state, and moves each of the lidars to a position where it does not protrude above the main body mechanism when the main body mechanism is in the low-floor state;
The transport device of claim 2 further comprising: an extendable hook mechanism that hooks onto a structural frame that constitutes the cart, including the front frame, the rear frame, and the center frame;
a hook mechanism drive unit that drives the hook mechanism;
Furthermore,
The conveying device according to claim 2, wherein the control unit controls the guide mechanism drive unit and the device drive unit so that the conveying device moves to the structural frame of the cart in the low-floor state, controls the guide mechanism drive unit and the hook mechanism drive unit so that the conveying device is in the normal height state and the hook mechanism hooks onto the structural frame , and controls the device drive unit so that the cart moves in the direction of being pulled out. a bumper mechanism extendable to a position protruding outward beyond at least the front frame and the rear frame;
an extendable hook mechanism that hooks onto a structural frame that constitutes the cart, including the front frame, the rear frame, and the center frame;
a bumper mechanism drive unit that drives the bumper mechanism and the hook mechanism so as to extend the hook mechanism in conjunction with extension of the bumper mechanism;
Furthermore,
The control unit controls the guide mechanism drive unit and the device drive unit so that the transport device moves to the structural frame of the cart in the low-floor state, controls the guide mechanism drive unit and the bumper mechanism drive unit so that the transport device is in the normal height state and the hook mechanism hooks onto the structural frame , and controls the device drive unit so that the transport device moves in the direction of pulling out the cart. a communication unit that communicates with an instruction center that instructs the transport device to transport the cart;
the communication unit receives, from the instruction center, a movement command including position information of the cart and position information of a destination of the cart;
The control unit controls the device driving unit to autonomously drive the conveying device to the position of the cart based on the movement command acquired by the communication unit, controls the device driving unit and the guide mechanism driving unit to engage the guide mechanism with the cart engaging unit, and controls the device driving unit to autonomously drive the conveying device to the destination of the cart with the cart engaging unit and the guide mechanism engaged. A transport method for transporting a cart using a transport device, the cart having a front frame, a rear frame facing the front frame, a center frame connecting the front frame and the rear frame, connecting fittings attached to the center frame so as to protrude in a direction different from the extending direction of the center frame, and a plurality of casters,
a guide mechanism provided in the transport device is fitted to a cart fitting portion formed by the center frame and the connecting fitting based on the detection results of a group of sensors provided in the transport device;
When the guide mechanism is fitted into the cart fitting portion, a predetermined gap exists between the cart fitting portion and the guide mechanism ,
The cart fitting portion is configured such that the center frame and the connecting fitting are perpendicular to each other,
The guide mechanism is composed of a center frame groove that can be fitted onto the center frame and a connecting fitting groove that can be fitted onto the connecting fitting .