Automatic conveyance system and mobile robot

Abstract

The present invention provides a mobile robot and an automatic conveyance system capable of conveying a conveyed body without increasing the ground load of the mobile robot or providing the mobile robot with a lifting mechanism. The present invention provides an automatic conveyance system having a mobile robot and a conveyed body, wherein: the mobile robot has a main body and drive wheels; the main body has a first engagement part configured so as to be capable of engaging the conveyed body; the drive wheels are rotatably supported by the main body; the conveyed body has a frame part and wheels; the frame part has a second engagement part configured so as to be capable of engaging the first engagement part of the mobile robot; and some of the weight of the conveyed body is supported by the mobile robot in an engaged state in which the first engagement part and the second engagement part have engaged each other.

Description

Automated Transport System and Mobile Robot

[0001] The present invention relates to a mobile robot for transporting a conveyed object having wheels, and an automated transport system having the mobile robot and the conveyed object.

[0002] Conventionally, for example, in order to solve the shortage of manpower in article transportation in stores and logistics warehouses and in-process transportation in factories, the introduction of autonomous mobile robots (AMRs: Autonomous Mobile Robots) and the like has been progressing.

[0003] Patent Document 1 discloses a technique of using an autonomous mobile robot as a transport vehicle for towing a cage cart. The transport vehicle as an autonomous mobile robot is said to be capable of autonomously traveling on the floor while towing a cage cart in a factory, warehouse, logistics center, etc.

[0004] Japanese Unexamined Patent Application Publication No. 特開2024-111399 (这里原文中“特開2024-111399号公報”直接保留日文,因为没有明确要求翻译专利号的中文内容,如果需要翻译可以进一步说明)

[0005] However, in order for a mobile robot to tow a cart, it is necessary to increase the ground contact load by increasing the weight of the mobile robot or the like. On the other hand, although there is also a conventional technique in which a mobile robot lifts a cart to increase the ground contact load, in such a conventional technique, it is necessary to provide a lifting mechanism or the like for raising and lowering the cart on the mobile robot.

[0006] An object of the present invention is to provide a mobile robot and an automated transport system capable of transporting a conveyed object without increasing the ground contact load of the mobile robot or providing a lifting mechanism on the mobile robot.

[0007] The present invention provides the following inventions: [1] An automatic transport system comprising a mobile robot and a transported object, wherein the mobile robot comprises a body and drive wheels, the body comprises a first engagement portion configured to engage with the transported object, the drive wheels are rotatably supported on the body, the transported object comprises a frame portion and wheels, the frame portion comprises a second engagement portion configured to engage with the first engagement portion of the mobile robot, and the mobile robot is configured to support a portion of the weight of the transported object in an engaged state in which the first engagement portion and the second engagement portion are engaged. [2] The automatic transport system according to [1], wherein the wheels of the transported object comprises a front wheel and a rear wheel, and the front wheel or the rear wheel is configured to be lifted off the ground in an engaged state in which the first engagement portion and the second engagement portion are engaged. [3] An automatic transport system according to [2], wherein the first engaging portion of the main body has a guide portion inclined toward the side facing the second engaging portion, the second engaging portion of the base portion has a guided portion that is guided by the guide portion, and when the first engaging portion and the second engaging portion are engaged, the guided portion is guided by the guide portion so that one of the front wheels or the rear wheels is lifted off the ground. [4] An automatic transport system according to any one of [1] to [3], wherein the main body of the mobile robot has an upper body, a middle body, and a lower body, the upper body and the lower body are each configured to be rotatable relative to the middle body, the drive wheels are provided on the lower body, the first engaging portion is provided on the middle body, and the middle body is configured to support a portion of the weight of the transported object.[5] A mobile robot for transporting a wheeled object, wherein the mobile robot has a main body and drive wheels, the main body has an upper body, a middle body and a lower body, the upper body and the lower body are each configured to rotate relative to the middle body, the drive wheels are provided on the lower body, the middle body is provided with a first engagement portion configured to engage with the transported object, the first engagement portion has an inclined surface that is inclined toward the side facing the transported object, and when the first engagement portion and the transported object are engaged, the transported object is guided by the inclined surface so that the wheels on the engagement side of the transported object are lifted off the ground, and in the state in which the first engagement portion and the transported object are engaged, the middle body is configured to support a portion of the weight of the transported object.

[0008] According to the present invention, it is possible to realize a mobile robot and an automated transport system that can transport objects without increasing the ground load of the mobile robot or providing a lifting mechanism to the mobile robot.

[0009] Figure 1A shows an example of the configuration of the automatic transport system 1 in this embodiment, and Figure 1B shows an example of the configuration in which a trolley unit 30A is used as the functional unit 30. Figure 2A is a perspective view of the mobile robot 2 in this embodiment viewed from the front left, and Figure 2B is a perspective view of the mobile robot 2 viewed from the rear right. Figure 3A is a front view of the mobile robot 2, and Figure 3B is a right side view of the mobile robot 2. Figure 4A is a perspective view of the transported object 3 in this embodiment viewed from the rear right, and Figure 4B is a perspective view of the transported object 3 viewed from the upper front. Figure 5A shows the unengaged state before the mobile robot 2 and the transported object 3 are engaged, and Figure 5B shows the engaged state after the mobile robot 2 and the transported object 3 are engaged. Figure 6A shows the locked state in which the lock lever 35 of the transported object 3 is caught on the pin 25 of the mobile robot 2, and Figure 6B shows the operation of releasing the locked state by the release pedal 36. Figure 7A is an enlarged view of the vicinity of the rotation restricting guide 37 and the width restricting guide 38, and Figure 7B is a schematic diagram showing the functions of the rotation restricting guide 37 and the width restricting guide 38. Figure 8A shows the state in which the mobile robot 2 and the transported object 3 are moving forward, and Figure 8B shows the state in which the transported object 3 moves in parallel as the mobile robot 2 moves forward to the right.

[0010] Embodiments of the present invention will be described with reference to the attached drawings. In each drawing, components denoted by the same reference numerals have the same or similar configurations.

[0011] <Overview of Automated Transport System 1> As shown in Figure 1A, the automated transport system 1 comprises a mobile robot 2 and an object to be transported 3. The mobile robot 2 is a mobile body that moves (drives) autonomously without requiring user operation. In this embodiment, an example will be described in which an autonomous mobile robot is used as the mobile robot 2 to transport the object to be transported 3, for example, in a store or logistics warehouse.

[0012] The transported object 3 comprises a frame 31, wheels 32A to 32D, and a functional unit 30. The frame 31 has a frame structure configured to support the functional unit 30. The wheels 32A to 32D are attached to the bottom of the frame 31. In this embodiment, the transported object 3 has two wheels 32A and 32B as front wheels and two wheels 32C and 32D as rear wheels. However, the number of wheels provided on the frame 31 is not limited to this, and the number of wheels can be increased or decreased as appropriate depending on the operating environment, etc.

[0013] The functional unit 30 is configured to provide various functions to the transported object 3. An example of the functional unit 30 is the trolley unit 30A for transporting goods, as shown in Figure 1B. Other examples of the functional unit 30 include an imaging unit for imaging the condition of product shelves, a customer service unit for guiding shoppers, an information display unit for displaying information for sales promotion, a tray unit with multi-tiered trays, and a serving unit for transporting food, beverages, and tableware. Depending on the usage environment, the user can select one of the multiple types of transported objects 3 that has the desired function and connect it to the mobile robot 2. The method for connecting the transported object 3 to the mobile robot 2 will be described later.

[0014] <Mobile Robot 2> As shown in Figures 2A and 2B, the mobile robot 2 has a main body 21 and drive wheels 22A and 22B. Also, as shown in Figures 3A and 3B, the main body 21 has an upper body 21A, a middle body 21B, and a lower body 21C, in order from top to bottom in the height direction. The upper body 21A and the lower body 21C are each configured to be rotatable relative to the middle body 21B. The upper body 21A and the lower body 21C are configured to be able to rotate by motor control or the like. The upper body 21A and the middle body 21B are also configured to be switchable between a coupled state in which they operate as a single unit and a separated state in which they operate independently of each other. The upper body 21A is provided with, for example, a camera for autonomous driving and lights for illumination. The middle body 21B is provided with a first engagement part 23 configured to be able to engage with the transported object 3. The middle body 21B is also provided with a pin 25 for locking the engagement state with the transported object 3. The lower body 21C is provided with drive wheels 22A, 22B and driven wheels 24A, 24B.

[0015] The drive wheels 22A and 22B are rotatably supported on the lower body 21C of the main body 21. Furthermore, the drive wheels 22A and 22B are driven independently on the left and right sides. For example, the mobile robot 2 can move forward when both drive wheels 22A and 22B rotate in the forward direction, move backward when both rotate in the reverse direction, and turn while stationary when they rotate in opposite directions. It is also possible to turn in a desired direction while moving forward by having the drive wheels 22A and 22B rotate in the forward direction at different rotational speeds. The driven wheels 24A and 24B are configured to change direction freely and can operate in accordance with the movement of the drive wheels 22A and 22B. In this embodiment, the mobile robot 2 is equipped with two drive wheels 22A and 22B and two driven wheels 24A and 24B, but the number of drive wheels and driven wheels can be increased or decreased as appropriate.

[0016] The aforementioned drive wheels 22A and 22B may be driven and controlled by, for example, a rotary drive unit (e.g., a motor) whose rotational speed can be freely adjusted, or a drive control unit (e.g., a motor driver) for controlling the rotary drive unit. Furthermore, a battery 26 (see Figure 2B) may be used to supply power to the rotary drive unit and the drive control unit.

[0017] Here, the first engaging portion 23 will be described using Figures 3A and 3B. The middle body 21B is configured to have a smaller cross-sectional area in plan view compared to the upper body 21A and the lower body 21C. For this reason, the outer circumferential surface of the middle body 21B is recessed compared to the outer circumferential surfaces of the upper body 21A and the lower body 21C. The first engaging portion 23 is provided along the outer circumferential surface of the middle body 21B at a position sandwiched between the upper body 21A and the lower body 21C. The first engaging portion 23 is provided on the right and left sides of the middle body 21B, respectively, and is configured to engage with the engaging portion on the transported object 3 side, which will be described later.

[0018] The engagement portion on the transported object 3 side will be explained using Figures 4A and 4B. For the sake of explanation, the functional unit 30 on the base portion 31 of the transported object 3 will not be shown. The base portion 31 of the transported object 3 is provided with a pair of second engagement portions 33. The second engagement portion 33 is an arm member whose base end is attached to the base portion 31 and whose tip is attached to a small rotating body 34. The second engagement portion 33 extends from the base portion 31 in the direction facing the mobile robot 2 when connected. The base portion 31 is also provided with a lock lever 35 that is sandwiched between the pair of second engagement portions 33. The lock lever 35 has a hook portion configured to catch on the pin 25 on the mobile robot 2 side. The lock lever 35 is normally in a locked state (closed state) due to the force from the elastic body, but it can be unlocked (opened state) by applying an external force that opposes the elastic force.

[0019] As shown in Figure 3B, the first engagement portion 23 on the mobile robot 2 side has a high, flat central portion in the front-to-back direction (left-to-right direction in Figure 3B) and inclined surfaces that slope forward and backward. Of these inclined surfaces, the inclined surface on the side into which the second engagement portion 33 of the transported object 3 is inserted (the right-hand inclined surface in Figure 3B) becomes the guide portion 23A for guiding the second engagement portion 33. In this embodiment, since the second engagement portion 33 of the transported object 3 is inserted into the first engagement portion 23 from the front of the mobile robot 2, the inclined surface on the front side becomes the guide portion 23A.

[0020] <Method for connecting the transported object 3 to the mobile robot 2> Figure 5A shows the unengaged state before the mobile robot 2 and the transported object 3 are engaged. When engaging the mobile robot 2 and the transported object 3, the user first applies the brakes to prevent the mobile robot 2 from moving, and then places the transported object 3 in front of the mobile robot 2 while it is braked. The user gradually moves the transported object 3 closer to the mobile robot 2 and aligns the transported object 3 so that the pair of second engaging parts 33 each fit properly into the pair of first engaging parts 23.

[0021] Once the object to be transported 3 is aligned, the user pushes the object to be transported 3 further toward the mobile robot 2, inserting the pair of second engaging parts 33 into the pair of first engaging parts 23. The rotating body 34 of the second engaging part 33 is guided by the guide part 23A as it ascends the inclined surface and reaches the center of the first engaging part 23. When the rotating body 34 of the second engaging part 33 reaches the center of the first engaging part 23, the first engaging part 23 and the second engaging part 33 become engaged, as shown in Figure 5B, and the mobile robot 2 and the object to be transported 3 are connected. In this embodiment, the rotating body 34 corresponds to the guided part of the present invention. However, the guided part can be any member that can move smoothly along the guide part 23A, and it is also possible to configure the guided part with a low-friction tip instead of the rotating body 34.

[0022] When the first engaging portion 23 and the second engaging portion 33 are engaged, the pin 25 on the mobile robot 2 side comes into contact with the tapered tip of the lock lever 35, temporarily releasing the lock lever 35. After the hook portion of the lock lever 35 catches on the pin 25, the lock lever 35 returns to the locked state. Therefore, as soon as the first engaging portion 23 and the second engaging portion 33 become engaged, this engaged state is locked by the lock lever 35 and the pin 25.

[0023] Figure 6A shows the locked state in which the hook portion of the lock lever 35 of the transported object 3 is caught on the pin 25 of the mobile robot 2. In the locked state, the mobile robot 2 and the transported object 3 are firmly connected, preventing the transported object 3 from detaching from the mobile robot 2 during automatic transport. As shown in Figure 7A, the second engaging portion 33 is provided with a width restricting guide 38 facing the outer circumferential surface of the central body 21B. In the engaged state of the first engaging portion 23 and the second engaging portion 33, the pair of width restricting guides 38 abut against the central body 21B from both sides. Therefore, as shown in Figure 7B, the relative widthwise (left-right) movement of the mobile robot 2 and the transported object 3 is restricted. Furthermore, a rotation restricting guide 37 is provided below the lock lever 35. The rotation restricting guide 37 is fork-shaped and, in the engaged state of the first engaging portion 23 and the second engaging portion 33, clamps the pin 25 of the mobile robot 2 from both sides. Therefore, the rotational movement between the mobile robot 2 and the transported object 3 is restricted by the rotation restricting guide 37 and the width restricting guide 38 mentioned above.

[0024] Furthermore, when the first engaging portion 23 and the second engaging portion 33 are engaged, the rotating body 34 is guided by the guide portion 23A, causing the front wheels (wheels 32A, 32B) to lift off the ground. In other words, the weight of the transported object 3 is supported and transported by the rear wheels (wheels 32C, 32D) that are in contact with the ground on the transported object 3 side, and by the drive wheels 22A, 22B and driven wheels 24A, 24B of the mobile robot 2. As a result, in the engaged state where the first engaging portion 23 and the second engaging portion 33 are engaged, a portion of the weight of the transported object 3 is supported by the mobile robot 2.

[0025] The percentage of the weight of the transported object 3 that is supported by the mobile robot 2 can be adjusted by designing the relevant parts as appropriate. For example, the weight supported by the mobile robot 2 can be adjusted by appropriately designing the distance between the rear wheels (wheels 32C, 32D) of the transported object 3 and the drive wheels 22A, 22B of the mobile robot 2, and the position on the mobile robot 2 that supports the weight of the transported object 3 (pressure application point). For example, when a 100 kg load is placed on the trolley unit 30A shown in Figure 1B, the pressure application point can be appropriately set to adjust the load so that a desired weight between 20 and 80 kg is applied to the mobile robot 2. In this embodiment, when a 100 kg load is placed on the trolley unit 30A, the design is such that approximately 40 kg of weight is applied to the mobile robot 2, but it is not limited to this.

[0026] As described above, the mobile robot 2 can lift the transported object 3 without the need to install a lifting mechanism or the like. Furthermore, since it is possible to increase the ground load by utilizing a portion of the weight of the transported object 3, there is no need to increase the weight of the mobile robot 2 itself, and it is possible to suitably tow a transported object 3 that weighs several times its own weight. In addition, since it does not support the entire weight of the transported object 3, excessive robustness is not required of the mobile robot 2. For this reason, the mobile robot 2 can be designed to be lightweight and compact, achieving high versatility that can be used in a variety of situations.

[0027] Regarding the drive wheels 22A and 22B of the mobile robot 2, it is preferable that they be made of a material and have a shape that increases friction with the road surface, from the viewpoint of improving propulsion. On the other hand, regarding the rear wheels (wheels 32C and 32D) of the transported object 3, it is preferable that they be made of a material and have a shape that reduces friction with the floor surface, from the viewpoint of facilitating towing. For example, it is preferable to use a hard material with low friction with the floor surface, such as nylon or urethane, for the rear wheels (wheels 32C and 32D).

[0028] When replacing the transported object 3 connected to the mobile robot 2 with a transported object 3 having a different function, an unlocking operation is performed to remove the lock lever 35 that is hooked onto the pin 25 of the mobile robot 2. The unlocking operation is simple and can be performed by the user pressing the release pedal 36, as shown in Figure 6B. The lower part of the release pedal 36 is provided with an inclined surface, and when the release pedal 36 is lowered, a force (horizontal force) is applied to the lock lever 35 in the direction of opening against the elastic force via the inclined surface. Therefore, with the brakes applied to the mobile robot 2, the transported object 3 can be easily disengaged and the connection released by pressing the release pedal 36 and moving the transported object 3 away from the mobile robot 2.

[0029] Considering the convenience of the mobile robot 2 towing the transported object 3, it is preferable that at least the rear wheels (wheels 32C, 32D) of the transported object 3 are swivel wheels (so-called 360-degree rotatable casters) configured to change direction freely. Figure 8A shows the mobile robot 2 and the transported object 3 moving forward. From this state, the case in which the mobile robot 2 moves to the right and forward, as shown in Figure 8B, will be described. As described above, the upper body 21A and the lower body 21C are each configured to rotate relative to the middle body 21B, and when moving to the right and forward, the lower body 21C rotates to the right while the middle body 21B remains facing forward. If the direction of the rear wheels (wheels 32C, 32D) can be freely changed, it becomes possible to move the transported object 3 in parallel in accordance with the movement of the mobile robot 2 to the right. As a result, for example, it becomes possible to move the transported object 3 to the side in a narrow aisle in a store with minimal space.

[0030] In Figure 8B, the upper body 21A remains facing forward and does not rotate. This corresponds to the fact that the rear wheels (wheels 32C, 32D) of the transported object 3 are swivel wheels. When the rear wheels (wheels 32C, 32D) of the transported object 3 are swivel wheels, it is preferable that the upper body 21A and the middle body 21B are coupled. This is because the rotational behavior of the transported object 3 is controlled by the motor of the mobile robot 2. On the other hand, when the rear wheels (wheels 32C, 32D) of the transported object 3 are not swivel wheels but fixed wheels with a fixed orientation, it is preferable that the upper body 21A and the middle body 21B are separated. If the rear wheels (wheels 32C, 32D) are fixed wheels, the rotation of the transported object 3 is restricted by the rear wheels (wheels 32C, 32D), so there is no need for control on the mobile robot 2 side. In this case, it is preferable to separate the upper body 21A and the middle body 21B, allowing both the upper body 21A and the lower body 21C to rotate independently. In the mobile robot 2, the upper body 21A can rotate freely even when towing the object to be transported 3. This is because the middle body 21B supports part of the weight of the object to be transported 3, so the weight of the object to be transported 3 does not rest on the upper body 21A. In this way, by supporting the weight of the object to be transported 3 with the middle body 21B, and by allowing the upper body 21A and the lower body 21C to rotate relative to the middle body 21B, the mobile robot 2 can perform various operations even while towing the object to be transported 3. Thus, the mobile robot 2 has the versatility to change the transport configuration in various ways depending on the type of object to be transported 3.

[0031] <Other Embodiments> - The mobile robot of the present invention includes not only the form of mobile robot 2 shown in the embodiment, but also autonomous vehicles with a vehicle-like appearance, etc. - The coupling operation between the mobile robot 2 and the transported object 3 may be performed manually by the user or automatically. Alternatively, the mobile robot 2 may approach the transported object 3 with the transported object 3 braked. - In the above embodiment, an example was described in which the front wheels (wheels 32A, 32B) are the engaging wheels and are lifted off the floor (ground), but the rear wheels (wheels 32C, 32D) may be the engaging wheels and be lifted off the floor (ground).

[0032] Furthermore, the embodiments described above are merely examples of how the present invention may be implemented, and the technical scope of the present invention should not be interpreted as being limited by these embodiments. In other words, the present invention can be implemented in various forms without departing from its gist or its main features.

[0033] 1: Automatic transport system, 2: Mobile robot, 3: Transported object, 21: Main body, 21A: Upper body, 21B: Middle body, 21C: Lower body, 22A: Drive wheel, 22B: Drive wheel, 23: First engagement part, 23A: Guide part, 24A: Driven wheel, 24B: Driven wheel, 25: Pin, 26: Battery, 30: Functional unit, 30A: Trolley unit, 31: Stand part, 32A: Wheel, 32B: Wheel, 32C: Wheel, 32D: Wheel, 33: Second engagement part, 34: Rotating body, 35: Lock lever, 36: Release pedal, 37: Rotation restricting guide, 38: Width restricting guide

Claims

1. An automated transport system comprising a mobile robot and a transported object, wherein the mobile robot has a body and drive wheels, the body has a first engaging portion configured to engage with the transported object, the drive wheels are rotatably supported on the body, the transported object has a frame and wheels, the frame has a second engaging portion configured to engage with the first engaging portion of the mobile robot, and the mobile robot is configured to support a portion of the weight of the transported object in an engaged state where the first engaging portion and the second engaging portion are engaged.

2. An automated transport system according to claim 1, wherein the wheels of the transported body have a front wheel and a rear wheel, and in an engaged state in which the first engaging portion and the second engaging portion are engaged, one of the front wheel or the rear wheel is lifted off the ground.

3. An automatic transport system according to claim 2, wherein the first engaging portion of the main body has a guide portion inclined toward the side facing the second engaging portion, the second engaging portion of the frame has a guided portion that is guided by the guide portion, and when the first engaging portion and the second engaging portion are engaged, the guided portion is guided by the guide portion, causing one of the front wheels or the rear wheels to be lifted off the ground.

4. An automated transport system according to any one of claims 1 to 3, wherein the main body of the mobile robot has an upper body, a middle body, and a lower body, the upper body and the lower body are each configured to be rotatable relative to the middle body, the lower body is provided with the drive wheels, the middle body is provided with the first engagement portion, and the middle body is configured to support a portion of the weight of the object to be transported.

5. A mobile robot for transporting a wheeled object, wherein the mobile robot has a main body and drive wheels, the main body has an upper body, a middle body and a lower body, the upper body and the lower body are each configured to rotate relative to the middle body, the drive wheels are provided on the lower body, the middle body is provided with a first engagement portion configured to engage with the transported object, the first engagement portion has an inclined surface that slopes toward the side facing the transported object, when the first engagement portion and the transported object are engaged, the transported object is guided by the inclined surface so that the wheels on the engagement side of the transported object are lifted off the ground, and in the state where the first engagement portion and the transported object are engaged, the middle body is configured to support a portion of the weight of the transported object.

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