Object conveyance system, control method and control program

Abstract

To provide an object conveyance system that is reduced in an installation cost although being excellent in object storage efficiency.SOLUTION: An object conveyance system comprises: a fixed shelf fixed at a predetermined position; a moving shelf moving by trackless first moving means; a conveyance robot moving by trackless second moving means along a path including a passage defined with the fixed shelf and / or the moving shelf to convey an object to the fixed shelf or the moving shelf, or from the fixed shelf or the moving shelf; a movement control unit which controls the movement of the moving shelf; and a conveyance robot control unit which controls the movement of the conveyance robot.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an object transport system, and more particularly to an object transport system that can be used in facilities such as warehouses. [Background technology]

[0002] In recent years, there has been an increase in the use of object transport systems in which shelves are provided inside a warehouse or the like, goods and other objects are stored on the shelves, and, as needed, a robot ships the objects from the shelves or replenishes the objects on the shelves.

[0003] Incidentally, in this type of system, a movable shelf is sometimes used from the viewpoint of improving the storage efficiency (or volumetric efficiency) of objects (Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2023-045436 A [Patent Document 2] JP 2003-081410 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, conventional conveying systems equipped with this type of movable shelf required the introduction of equipment for moving the movable shelf within a facility such as a warehouse, such as rails and large shelf moving mechanisms, resulting in high installation costs.

[0006] The present invention has been made in view of the above-mentioned technical background, and has an object to provide an object transport system that has good object storage efficiency while reducing installation costs. [Means for solving the problem]

[0007] The above-mentioned technical problems can be solved by an object transport system, a control method thereof, a program, etc. having the following configuration.

[0008] In other words, the object transport system of the present disclosure comprises a fixed shelf fixed at a predetermined position, a mobile shelf that moves by a first trackless moving means, a transport robot that moves along a path defined by the fixed shelf and / or the mobile shelf by a second trackless moving means and transports objects to or from the fixed shelf or the mobile shelf, a mobile shelf control unit that controls the movement of the mobile shelf, and a transport robot control unit that controls the movement of the transport robot.

[0009] According to this configuration, more shelves that can be accessed by the transport robot can be arranged in the target space, and the storage efficiency of objects in the facility can be improved. In addition, since not only movable shelves but also fixed shelves are included, the cost of the transport system can be reduced and the control process can be prevented from becoming complicated. Furthermore, since the movable shelves are equipped with trackless moving means, equipment required for moving the movable shelves, such as rails, steps, or grooves, is not required in the facility. Therefore, the installation cost of the object transport system can be reduced, and the transport efficiency can be improved because there is no equipment that can hinder the movement of the transport robot. In other words, it is possible to provide an object transport system that has good storage efficiency and transport efficiency for objects and reduced installation costs. Effect of the Invention

[0010] According to the present invention, it is possible to provide an object transport system that has good object storage efficiency and transport efficiency while reducing installation costs. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a plan view showing an example of the overall configuration of an object transport system. [Diagram 2] FIG. 2 is an explanatory diagram showing an example of a network configuration of an object transport system. [Diagram 3] FIG. 3 is a perspective view showing the overall configuration of the mobile manipulator. [Figure 4] FIG. 4 is an enlarged perspective view of the external appearance of the object manipulation unit. [Diagram 5] FIG. 5 is a functional block diagram of the WCS server. [Figure 6] FIG. 6 is a functional block diagram of the mobile manipulator. [Figure 7] FIG. 7 is a functional block diagram of the movable shelf. [Figure 8] FIG. 8 shows an example of the configuration of the movement mechanism. [Figure 9] FIG. 9 is a general flow chart of the operation of shipping an object on a shelf. [Figure 10] FIG. 10 is a detailed flowchart of a path planning process related to an object shipping operation. [Figure 11] FIG. 11 is an explanatory diagram of an area according to this embodiment. [Figure 12] FIG. 12 is an explanatory diagram of another example of setting areas. [Figure 13] FIG. 13 is an explanatory diagram regarding the accessible passages. [Figure 14] FIG. 14 is an explanatory diagram regarding the movement of the movable shelf. [Figure 15] FIG. 15 is a general flowchart of the operation of replenishing objects on a shelf. [Figure 16] FIG. 16 is a detailed flowchart of the path planning process related to the object replenishment operation. [Figure 17] FIG. 17 is an explanatory diagram according to a modified example in which self-position estimation is performed using a marker. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0013] 1. First Embodiment As a first embodiment, an example in which the present invention is applied to an object transport system installed in a warehouse will be described. Note that the facilities to which the object transport system is applied are not limited to warehouses, but include any facilities where the same type of function is required.

[0014] (1.1 Configuration of object transport system) FIG. 1 is a plan view showing an example of the overall configuration of an object transport system 900 installed in a warehouse 600 according to this embodiment. As is clear from the figure, a plurality of fixed shelves 610 and a plurality of movable shelves 630 are aligned parallel to each other in the warehouse 600. In this embodiment, each shelf is configured by connecting a plurality of shelves in a row. In addition, a plurality of caged carts 650 are lined up in a row along the wall of the warehouse 600. Furthermore, a plurality of mobile manipulators 100, which are mobile transport robots having an object manipulation function, are arranged between the shelves or between the shelves and the caged carts 650.

[0015] Each of the multiple mobile manipulators 100 transports an object between the fixed shelf 610 or the movable shelf 630 and the cage car 650. In this embodiment, when performing an object shipping task, the mobile manipulator 100 acquires (or picks up) an object from the fixed shelf 610 or the movable shelf 630 and places it on the cage car 650. On the other hand, when performing an object receiving (or object replenishment) task, the mobile manipulator 100 acquires an object from the cage car 650 and places it on an empty position on the fixed shelf 610 or the movable shelf 630.

[0016] According to such a configuration, more shelves that can be accessed by the mobile manipulator 100 can be arranged in the facility, and the storage efficiency of objects in the facility can be improved. In addition, since the system includes not only the movable shelf 630 but also the fixed shelf 610, it is possible to reduce the cost of the object transport system 900 and prevent the control process from becoming complicated.

[0017] In this embodiment, the cart 650 is exemplified as a target on which an object retrieved from a shelf is placed or an object that retrieves an object to be replenished to a shelf, but the present disclosure is not limited to such a configuration. Therefore, for example, a conveyor or the like may be disposed in place of the cart 650.

[0018] 2 is an explanatory diagram showing an example of a network configuration of an object transport system 900. As is clear from the figure, the object transport system 900 includes a WCS (Warehouse Control System) server 700, a WMS (Warehouse Management System) server 800, a plurality of mobile manipulators 100, and a movable shelf 630, which are connected to each other via a network such as the Internet.

[0019] The WMS server 800 is a server related to a host system of the WCS server 700 that manages information regarding the receipt and shipment of objects such as merchandise, and communicates with the WCS server 700 .

[0020] The WCS server 700 performs processes such as generating / managing batches, which are processing units for objects, generating / managing jobs (e.g., object shipping tasks or object replenishment tasks) for the mobile manipulator 100, managing objects (inventory) in the warehouse, managing vacant positions on the shelves, managing the positions of the mobile manipulator 100, and selecting entrance passages. The mobile manipulator 100 and the mobile shelf 630 each provide local position information to the WCS server 700.

[0021] As described below, the mobile manipulator 100 performs operations such as moving, picking up, and placing by communicating with the WCS server 700. Also, the movable shelf 630 moves by communicating with the WCS server 700, as described below.

[0022] For example, the WCS server 700 and the WMS server 800 may be integrated into one server.

[0023] 3 is an external perspective view showing the overall configuration of the mobile manipulator 100 according to this embodiment. A coordinate system consisting of three mutually orthogonal axes (x-axis, y-axis, z-axis) is displayed in the lower left of the figure, and hereinafter, the positive direction of the x-axis may be referred to as the forward direction, the negative direction as the backward direction, the positive direction of the y-axis as the leftward direction, the negative direction as the rightward direction, the positive direction of the z-axis as the upward direction, and the negative direction as the downward direction.

[0024] As is clear from the figure, the mobile manipulator 100 includes a main body 10 having an overall shape of a substantially rectangular parallelepiped with long sides in the vertical direction, a multi-joint robot arm unit 30 attached to the front end of the upper end of the main body 10, and an object manipulation unit 50 attached to the tip of the multi-joint robot arm unit 30. The left and right side surfaces of the main body 10 are parallel to the x-axis (xz plane), and the front and back surfaces are parallel to the y-axis (yz plane). In this embodiment, the multi-joint robot arm unit 30 and the object manipulation unit 50 are referred to separately, but they may be collectively referred to simply as a multi-joint robot arm.

[0025] As is clear from the figure, in this embodiment, the articulated robot arm unit 30 is disposed on the center line of the left-right width of the main body unit 10.

[0026] This configuration provides a good left-right weight balance for the mobile manipulator 100. Also, the left-right width of the mobile manipulator can be made smaller than when, for example, the articulated robot arm unit 30 is attached to the side surface.

[0027] On the front surface of the main body 10, object storage sections 15 each having seven rectangular parallelepiped spaces for storing objects are aligned vertically with their openings facing forward. Each space of the object storage section 15 has a size large enough to store at least one object.

[0028] According to this configuration, since the object storage unit 15 has multiple storage spaces, multiple objects can be transported simultaneously. In addition, since the spaces for storing objects are arranged vertically, the width of the mobile manipulator 100 can be reduced. This enables movement through narrow passages, etc.

[0029] The articulated robot arm unit 30 is attached above (vertically above) the object accommodation unit 15.

[0030] According to this configuration, the articulated robot arm unit 30 can be used to access the object storage unit 15 from above.

[0031] A LiDAR device 13 is installed on the top surface of the main body 10 via an upside-down U-shaped rod-like support member 12 in a position higher than the main body 10 in a manner that allows it to detect positions higher than each shelf. The LiDAR device 13 is, for example, a LiDAR unit, and can detect the distance, position, shape, etc., of an object.

[0032] According to such a configuration, sensing can be performed from a high position using the LiDAR device 13. This makes it possible to perform self-location estimation and the like more reliably even in the presence of a changing environment around the vehicle, such as a moving shelf.

[0033] The bottom surface of the main body 10 is provided with a differential pair of wheels (W1, W2) that are independently controlled and driven on the left and right sides and are configured with two wheels, as the moving mechanism 20. In addition, passive wheels W' that rotate passively are arranged on the four corners of the bottom surface.

[0034] According to this configuration, a low-cost movement mechanism can be realized by utilizing the differential two wheels.

[0035] In this embodiment, the articulated robot arm unit 30 has four rotationally driven joints (J1 to J4). One end (or base end) of a rod-shaped first link 31 is swingably connected to the upper and front end of the main body unit 10 via the first joint (J1). At this time, the central axis of rotation of the first joint (J1) is a horizontal axis (or pitch axis) extending in the left-right direction.

[0036] One end (or base end) of the rod-shaped second link 32 is swingably connected to the other end (or tip) of the first link 31 via a second joint (J2). At this time, the rotation center axis of the second joint (J2) is a horizontal axis (or pitch axis) extending in the left-right direction.

[0037] One end (base end) of the third link 33, which is bent shorter than the first link 31 and the second link 32, is swingably connected to the other end (or tip) of the second link 32 via a third joint (J3). At this time, the rotation center axis of the third joint (J3) is a horizontal axis (or pitch axis) extending in the left-right direction.

[0038] According to such a configuration, the hand position of the third link 33 can be freely positioned on a plane (xz plane) parallel to the side surface of the main body unit 10. This increases the degree of freedom in the positioning of the object manipulation unit 50.

[0039] The object manipulator 50 is rotatably attached via a fourth joint (J4) to the tip of the third link 33. The rotation center axis of the fourth joint (J4) is parallel to the normal to the top surface of the object manipulator 50, and is parallel to the vertical axis in the example shown in the figure.

[0040] An extension line of the rotation central axis of the fourth joint (J4) passes through a placement portion (described later) for an object formed on the base body 51. In the example shown in the figure, the extension line of the fourth joint (J4) is perpendicular to the plane formed by the placement portion.

[0041] According to this configuration, the radius of rotation when the base body 51 is rotated at the fourth joint (J4) can be made small. This makes it possible to perform work in a narrow space. In particular, when the rotation center axis of the fourth joint (J4) is perpendicular to the plane of the mounting part, the positional relationship can be simplified, which makes it easier to perform posture calculations, for example.

[0042] In this embodiment, the object manipulation unit 50 has four drive joints (J5 to J8).

[0043] 4 is an enlarged external perspective view of the object manipulator 50. In this embodiment, the object manipulator 50 has a substantially U-shaped base body 51 that is laid on its side in the figure. A first slide member 52 is slidably attached to one side of the bottom surface of the base body 51 via a first linear joint (JL1) (or a fifth joint (J5)).

[0044] A second slide member 53 is slidably attached to the top surface side of the first slide member 52 via a second translation joint (JL2) (or a sixth joint (J6)). The axes of the first translation joint (JL1) and the second translation joint (JL2) are parallel to each other.

[0045] At this time, the first prismatic joint (JL1) and the second prismatic joint (JL2) are controlled independently and are not interlocked.

[0046] According to such a configuration, the manner in which an object is gripped can be freely controlled, and the first slide member 52 can be prevented from interfering with the object to be gripped.

[0047] In this embodiment, the second slide member 53 is provided with a gripper as an end effector, which includes left and right claws (55L, 55R) and left and right drive units (551L, 551R) that linearly move the claws in the opening and closing directions. These drive units (551L, 551R) respectively constitute a third translation joint (JL3) (or a seventh joint (J7)) and a fourth translation joint (or an eighth joint (J8)). The left and right claws (55L, 55R) are provided with sensors (not shown) that detect contact or force.

[0048] A first camera 56 is provided at the upper end of the base 51 and oriented in an axial direction parallel to the first linear axis (JL1) or the second linear axis (JL2). The first camera 56 has, for example, a function as an RGB camera and a function as a ToF (Time of Flight) camera. As described later, the first camera 56 can be used to recognize markers, objects, and surrounding spaces (gaps) of objects.

[0049] The second slide member 53, particularly near the center of the gripper, is provided with a distance sensor 58 oriented in an axial direction parallel to the first linear axis (JL1) or the second linear axis (JL2). By using this distance sensor 58, it is possible to detect the relative distance between the object and the gripper. This makes it possible to detect whether or not slippage occurs between the object and the jaws 55 when gripping the object.

[0050] A second camera 57 is provided directly above the distance sensor 58 and is oriented in an axial direction parallel to the first linear axis (JL1) or the second linear axis (JL2). The second camera 57 is, for example, a monochrome camera, and captures an identifier such as a barcode attached to an object. Based on this captured image, for example, identification or recognition processing of the object or its contents is performed. Note that the second camera 57 may have a higher resolution and a narrower angle of view than the first camera 56.

[0051] It should be noted that the sensors attached to object manipulation unit 50 are not limited to these sensors (first camera 56, second camera 57, distance sensor 58). Therefore, various known sensors may also be employed.

[0052] 5 is a functional block diagram of the WCS server 700. As is clear from the diagram, the WCS server 700 includes a control unit 701, a storage unit 702, a communication unit 703, a display output unit 705, an audio output unit 706, and an input unit 708, which are connected to each other via a bus.

[0053] The control unit 701 is a calculation device such as a CPU, and executes various processes described below according to a program read from the storage unit 702. The storage unit 702 is a storage device such as a ROM, RAM, or flash memory, and stores programs and various data. The communication unit 703 is a communication unit for wireless communication, and transmits and receives information to and from an external device. The display output unit 705 performs a process of outputting an image to a display means such as a display according to the control of the control unit 701. The audio output unit 706 performs a process of outputting an audio signal to an audio output means such as a speaker according to the control of the control unit 701. The input unit 708 processes inputs through input means such as a keyboard or mouse, and provides the inputs to the control unit 701, etc.

[0054] Incidentally, the WMS server 800 has a similar configuration to that shown in FIG. 5, and therefore a detailed description thereof will be omitted.

[0055] 6 is a functional block diagram of the mobile manipulator 100. As is clear from the figure, the mobile manipulator 100 includes a control unit 101, a storage unit 102, a communication unit 103, a LiDAR device 13, a movement mechanism unit 20, an articulated robot arm unit 30, and an object manipulation unit 50, which are connected to each other via a bus.

[0056] The control unit 101 is a calculation device such as a CPU, and executes various processes described below according to a program read from the storage unit 102. The storage unit 102 is a storage device such as a ROM, a RAM, or a flash memory, and stores programs and various data. The communication unit 103 is a communication unit for wireless communication, and transmits and receives information to and from an external device. The LiDAR device 13 is a sensor unit, and acquires the distance, position, shape, and the like of the environment. The acquired information is stored in the storage unit 102, etc., and is used by the control unit 101.

[0057] The articulated robot arm unit 30 is provided with an arm drive unit including an actuator used to drive the joints, and an arm sensor that acquires the state of the articulated robot arm unit 30 such as the joint angles.

[0058] The moving mechanism unit 20 is a trackless moving mechanism that does not require rails or the like, and includes a wheel drive unit, which is a drive circuit for driving the driving wheels (W1, W2), and a wheel sensor that detects the rotation state of the driving wheels (W1, W2). Information detected via the sensor is stored in the memory unit 102 or used by the control unit 101.

[0059] The object manipulator 50 is equipped with a left claw drive unit and a right claw drive unit to independently drive each joint (JL3, JL4) of the left and right claws (55L, 55R). Also, to drive the first linear joint (JL1) and the second linear joint (JL2), the object manipulator 50 is equipped with a first linear shaft drive unit and a second linear shaft drive unit, which are circuits that drive the first linear joint (JL1) and the second linear joint (JL2), respectively. In addition to this, the object manipulator 50 is equipped with a sensor that detects force or contact acting on the claws 55.

[0060] In addition, the object manipulation unit 50 is equipped with various sensors, namely, a first camera 56, a second camera 57, and a distance sensor 58, and information obtained via the sensors is stored in the memory unit 102 or used by the control unit 101.

[0061] 7 is a functional block diagram of the movable shelf 630. As is clear from the figure, the movable shelf 630 includes a control unit 631, a storage unit 632, a communication unit 633, a LiDAR device 635, and a movement mechanism unit 636, which are connected to each other via a bus.

[0062] The control unit 631 is a calculation device such as a CPU, and executes various processes described below according to a program read from the storage unit 632. The storage unit 632 is a storage device such as a ROM, RAM, or flash memory, and stores programs and various data. The communication unit 633 is a communication unit for wireless communication, and transmits and receives information to and from an external device. The LiDAR device 635 is a sensor unit, and acquires the distance, position, shape, and the like of the environment. The acquired information is stored in the storage unit 632, etc., and is used by the control unit 631.

[0063] The moving mechanism 636 is a trackless moving means that does not require rails, etc. That is, the moving mechanism 636 includes a plurality of wheels that move the movable shelf 630, a plurality of motors that drive each wheel, and a plurality of motor drive circuits that drive each motor.

[0064] According to this configuration, there is no need for equipment required for moving the movable shelf 630, such as rails, steps, or grooves, within the warehouse 600. Therefore, the installation cost of the object transport system 900 can be reduced, and the transportation efficiency can be improved because there is no equipment that can hinder the movement of the mobile manipulator 100.

[0065] 8 is a configuration example of the movement mechanism unit 636. As is clear from the figure, the movement mechanism unit 636 includes three wheels (not shown), three motors 6362 for driving the wheels, and three motor drive circuits 6361 for driving the motors, and the motor drive circuits 6361 are connected in series to each other via communication lines. In this case, for example, EtherCAT or the like may be adopted as the communication standard.

[0066] The above configuration is merely an example, and the configuration may be modified in various ways, such as by adding, changing, or deleting elements.

[0067] (1.2 Operation of the object transport system) (Actions related to shipping objects from shelves) FIG. 9 is a general flow chart of the operation of shipping an object on a shelf.

[0068] As is clear from the figure, when processing starts, the WCS server 700 performs processing to identify the target object to be acquired from the shelf and its position on the shelf (S11). More specifically, the WCS server 700 acquires information related to the import and export of objects from the WMS server 800, and identifies the object to be acquired from the shelf and placed on the cart 650.

[0069] Once the object has been identified, the WCS server 700 performs a process of selecting one mobile manipulator 100 from among the multiple mobile manipulators 100 in the warehouse 600 (S12). This selection may be performed based on any criteria, but may be selected arbitrarily from among the mobile manipulators 100 that have not been assigned any work (or job), for example.

[0070] After the selection process of the mobile manipulator 100, the WCS server 700 performs a process of planning a movement path of the mobile manipulator 100 from the current position to in front of a target object on a shelf (S13). The details of the path planning process will be described later.

[0071] After the path planning process, the WCS server 700 issues a movement command to the selected mobile manipulator 700 based on the generated movement path (S15). The mobile manipulator 100 performs movement processing according to the commanded movement path (S16). Various methods can be applied as a movement processing method, but in this embodiment, a movement method in which the LiDAR device 13 is used to estimate the self-position and move autonomously is adopted. When the mobile manipulator 100 moves to the target position, it transmits a signal indicating the completion of movement to the WCS server 700 (S16).

[0072] Upon receiving the movement completion signal, the WCS server 700 generates a command to pick up (or obtain) the object in front of the mobile manipulator 100 and performs a process of transmitting the command to the mobile manipulator 100 (S17). Upon receiving this picking command, the mobile manipulator 100 performs a process of picking up the target object using the articulated robot arm unit 30 and the object manipulation unit 50 and storing it in the object storage unit 15 of the mobile manipulator 100 (S18). This completes preparation for transporting the object. Upon completing the picking, the mobile manipulator 100 performs a process of transmitting a signal indicating completion of picking to the WCS server 700 (S18).

[0073] Upon receiving the picking completion signal, the WCS server 700 generates a signal commanding the mobile manipulator 100 to move from in front of the shelf to the cart 650, and transmits this signal to the mobile manipulator 100 (S19). In response to this movement command, the mobile manipulator 100 moves toward the cart 650 (S20). Once this movement is complete and the mobile manipulator 100 has moved in front of the cart 650, the mobile manipulator 100 transmits a movement completion signal to the WCS server 700 (S20).

[0074] Upon receiving the movement completion signal, the WCS server 700 generates a command to remove the stored object and place it on the cart 650, i.e., a drop-off command, and transmits it to the mobile manipulator 100 (S21). Upon receiving the drop-off command, the mobile manipulator 100 uses the articulated robot arm unit 30 and the object manipulation unit 50 to remove the object stored in the object storage unit 15 and place it on the cart 650 (S22). Upon completion of this drop-off process, the mobile manipulator 100 transmits a signal indicating the completion of drop-off to the WCS server 70 (S22), and goes into standby state again (S23).

[0075] 10 is a detailed flowchart of a route planning process for an object shipping operation. As is clear from the figure, when the process starts, a process is performed to select one area from a plurality of virtual areas set in advance in the warehouse 600 (S131). Each area includes one or more fixed shelves 610 or movable shelves 630, and a passage defined by the fixed shelves 610 or movable shelves 630 is formed.

[0076] 11 is an explanatory diagram of an area according to this embodiment. In the figure, an area surrounded by a dashed line represents one area 680. Fixed shelves 610 are arranged at the left and right ends of the area 680, and multiple movable shelves 630 are arranged between the fixed shelves 610. Furthermore, four free passages (reference numerals 1 to 4 in the figure) through which the mobile manipulator 100 can physically enter are formed between the movable shelves 630. That is, in the example of the figure, multiple passages are formed within one area 680.

[0077] In this manner, with the configuration in which the fixed shelf 610 is provided at the end of the area 680, the fixed shelf 610 can be used as a reference, thereby preventing the control process from becoming unnecessarily complicated. The area can be set in various ways.

[0078] 12 is an explanatory diagram of another example of setting areas. In this figure, three areas (690a, 690b, 690c) are set so as to straddle adjacent fixed shelves 610. In the example of this figure, each area 690 includes two movable shelves 630 and one empty aisle.

[0079] According to such a configuration in which one path is provided for each area 680, the process for selecting the path can be simplified, and high-speed processing and the like become possible.

[0080] Returning to FIG. 9, when the area selection process is completed, the WCS server 700 searches for objects on shelves in the selected reference area and determines whether or not a target object exists in the area (S132). If the target object does not exist (S132 NO), the WCS server 700 performs a process to change the reference area (S133) and performs a determination process (S132) for the new reference area. On the other hand, if a target object exists in the area, the WCS server 700 performs a process to confirm an accessible passage (S135). Here, in this embodiment, an accessible passage is a passage that is not reserved (and not occupied) by another mobile manipulator 100.

[0081] According to this configuration, when performing an object pickup task, the presence or absence of an object can be determined on an area-by-area basis, making it possible to perform efficient path selection.

[0082] 13 is an explanatory diagram of an enterable passage. In the figure, of the four vacant passages, the first passage from the left is reserved (and occupied) by another mobile manipulator 100. In this state, since the first vacant passage from the left is reserved by the other mobile manipulator 100, it is confirmed that the passage is not enterable, and only the other passages are confirmed as enterable.

[0083] After the process of checking the available entry passage, the WCS server 700 judges whether or not an available entry passage exists (S136). If an available entry passage does not exist, the WCS server 700 performs a process of changing the reference area (S133) and performs a process of judging the target object again for that area (S132). On the other hand, if an available entry passage exists, the WCS server 700 performs a process of acquiring the current position of the movable shelf 630 (S137).

[0084] After the acquisition process, it is determined whether or not the target object can be picked up in the currently accessible empty passage based on the current position of the movable shelf 630 (S138).

[0085] If the result of the determination process indicates that the target object can be picked up in an empty passage that is currently available for entry (S138 YES), a process is performed to select the passage closest to the mobile manipulator 100 from among the passages that satisfy the condition (S141). After this passage selection process, the WCS server 700 reserves the passage to prohibit other mobile manipulators 100 from entering (S142). After the reservation process, the WCS server 700 performs a process to generate a route for moving from the current position of the mobile manipulator 100 through the reserved passage to the front of the target object on the shelf (S143). Then, the process ends.

[0086] On the other hand, if the result of the judgment process is that the target object cannot be picked up in the currently accessible empty passage (S138 NO), a process is performed to select the passage closest to the mobile manipulator 100 among the passages occupied by the mobile rack 630 but capable of picking up the target object (S145). After this passage selection process, the WCS server 700 reserves the passage to prohibit other mobile manipulators 100 from entering (S146). After the reservation process, the WCS server 700 issues a movement command to the mobile rack 630 to make the reserved passage an empty passage (S147). In response to this movement command, the mobile rack 630 performs a process to move the reserved passage to make it an empty passage (S14 in FIG. 9). When the movement is completed, the mobile rack 630 transmits a movement completion signal to the WCS server 700 (S14).

[0087] FIG. 14 is an explanatory diagram regarding the movement of the movable shelf 630. FIG. 14(A) shows the state before the movable shelf 630 moves, and FIG. 14(B) shows the state after the movable shelf 630 moves. In the example of FIG. 14, the sixth shelf from the left (movable shelf 630a) moves in parallel one row to the right, thereby forming an empty passage to the left of the movable shelf 630a. Note that this empty passage is already in a reserved state. This allows the mobile manipulator 100 to access an object on the fifth shelf from the left (movable shelf 630).

[0088] 10, when the WCS server 700, which has been in a standby state (S148 NO) until the movement of the movable shelf 630 is completed, receives a movement completion signal (S148 YES), it performs processing to generate a path for moving the mobile manipulator 100 from the current position to the front of the target object on the shelf through the reserved passage (S143). Then, the processing ends.

[0089] According to the above configuration, it is possible to provide an object transport system 900 that has good object storage efficiency and transport efficiency while reducing installation costs.

[0090] (Actions related to replenishing objects on shelves) FIG. 15 is a general flowchart of the operation of replenishing objects on a shelf.

[0091] As is clear from the figure, when processing starts, the WCS server 700 performs processing to identify objects to be replenished on the shelves and vacant positions on the shelves (S31). More specifically, the WCS server 700 acquires information on the receipt and shipment of objects from the WMS server 800, and identifies the objects acquired from the cart 650 to be placed on the shelves and the vacant positions on the shelves.

[0092] When the identification process is completed, the WCS server 700 performs a process of selecting one mobile manipulator 100 from among the multiple mobile manipulators 100 in the warehouse 600 (S32). This selection may be performed based on any criteria, but may be arbitrarily selected from mobile manipulators 100 that have not been assigned any work (or job), for example.

[0093] After the selection process of the mobile manipulator 100, the WCS server 700 generates a command for the mobile manipulator 100 to move from its current position to in front of a predetermined cart 650, and transmits the command to the mobile manipulator 100 (S33). The mobile manipulator 100 performs a movement process according to the commanded movement path (S35). Various methods can be applied as a movement process method, but in this embodiment, a movement method is adopted in which the LiDAR device 13 is used to estimate the self-position and move autonomously. When the mobile manipulator 100 moves to the target position, it transmits a signal indicating the completion of movement to the WCS server 700 (S35).

[0094] Upon receiving the movement completion signal, the WCS server 700 generates a command to pick up (or obtain) the object in front of the mobile manipulator 100 and performs a process of transmitting the command to the mobile manipulator 100 (S36). Upon receiving this picking command, the mobile manipulator 100 performs a process of picking up the target object using the articulated robot arm unit 30 and the object manipulation unit 50 and storing it in the object storage unit 15 of the mobile manipulator 100 (S37). This completes preparation for transporting the object. Upon completing the picking, the mobile manipulator 100 performs a process of transmitting a signal indicating completion of picking to the WCS server 700 (S37).

[0095] When the picking completion signal is received, the WCS server 700 performs processing to plan a movement path for the mobile manipulator 100 from the current position to the target vacant position on the shelf (S38). The details of the path planning processing will be described later.

[0096] After the path planning process, the WCS server 700 issues a movement command to the selected mobile manipulator 700 based on the generated movement path (S42). The mobile manipulator 100 performs movement processing according to the commanded movement path (S43). When the mobile manipulator 100 moves to the target position, it transmits a signal indicating the completion of movement to the WCS server 700 (S43).

[0097] Upon receiving the movement completion signal, the WCS server 700 generates a command to place the stored object in a target vacant position on the shelf, i.e., a drop-off command, and transmits it to the mobile manipulator 100 (S45). Upon receiving the drop-off command, the mobile manipulator 100 uses the articulated robot arm unit 30 and the object manipulation unit 50 to take out the object stored in the object storage unit 15 and place it in the target vacant position (S46). Upon completion of this drop-off process, the mobile manipulator 100 transmits a signal indicating the drop-off completion to the WCS server 70 (S46), and goes into standby state again (S47).

[0098] 16 is a detailed flowchart of a path planning process for an object replenishment operation. As is clear from the figure, when the process starts, a process is performed to select one area from a plurality of virtual areas previously set in the warehouse 600 (S381). Each area includes one or more fixed shelves 610 or movable shelves 630, and a passage defined by the fixed shelves 610 or movable shelves 630 is formed.

[0099] When the area selection process is completed, the WCS server 700 searches the selected reference area and judges whether or not a target vacant position exists within the area (S382). If the target vacant position does not exist (S382 NO), the WCS server 700 performs a process to change the reference area (S383) and performs a judgment process (S382) for the new reference area. On the other hand, if the target vacant position exists within the area, the WCS server 700 performs a process to confirm an accessible passage (S385). Here, in this embodiment, an accessible passage is a passage that is not reserved (and not occupied) by another mobile manipulator 100.

[0100] According to such a configuration, when performing an object replenishment task, the presence or absence of an empty position can be determined for each area, so that an efficient path selection can be performed.

[0101] After the process of checking the available entrance passage, the WCS server 700 judges whether or not an available entrance passage exists (S386). If an available entrance passage does not exist, the WCS server 700 performs a process of changing the reference area (S383) and performs a process of judging the target vacant position again for that area (S382). On the other hand, if an available entrance passage exists, the WCS server 700 performs a process of acquiring the current position of the movable shelf 630 (S387).

[0102] After the acquisition process, it is determined whether or not the target vacant position can be accessed through the currently accessible vacant aisle based on the current position of the movable shelf 630 (S388).

[0103] If the result of the judgment process shows that the target vacant position can be accessed through the currently accessible vacant passage (S388 YES), a process is performed to select the passage closest to the mobile manipulator 100 from among the passages that satisfy the condition (S391). After this passage selection process, the WCS server 700 reserves the passage so as to prohibit the entry of other mobile manipulators 100 (S392). After the reservation process, the WCS server 700 performs a process to generate a route that moves from the current position of the mobile manipulator 100 through the reserved passage to the front of the target vacant position on the shelf (S393). Then, the process ends.

[0104] On the other hand, if the result of the judgment process is that the target vacant position cannot be accessed through the currently accessible vacant passage (S388 NO), a process is performed to select a passage that is closest to the mobile manipulator 100 among the passages that are occupied by the mobile rack 630 but can access the target vacant position (S395). After this passage selection process, the WCS server 700 reserves the passage to prohibit other mobile manipulators 100 from entering (S396). After the reservation process, the WCS server 700 issues a movement command to the mobile rack 630 to make the reserved passage a vacant passage (S397). In response to this movement command, the mobile rack 630 performs a process to move the reserved passage to make it a vacant passage (S41 in FIG. 15). When the movement is completed, the mobile rack 630 transmits a movement completion signal to the WCS server 700 (S41).

[0105] The WCS server 700, which has been in a standby state (S398 NO) until the movement of the movable shelf 630 is completed, performs a process of generating a movement path for moving the mobile manipulator 100 from the current position to the front of the target vacant position on the shelf through the reserved passage when it receives the movement completion signal (S398 YES) (S393). Then, the process ends.

[0106] According to the above configuration, it is possible to provide an object transport system 900 that has good object storage efficiency and transport efficiency while reducing installation costs.

[0107] (2. Modifications) In the above embodiment, the mobile manipulator 100 and the movable shelf 630 perform self-localization using the LiDAR device (13, 635), but the present disclosure is not limited to such a configuration. Therefore, various known methods can be adopted.

[0108] 17 is an explanatory diagram of a modified example in which self-location estimation is performed using a marker 6301. In the example of the figure, markers 6301 are placed at regular intervals on the floor surface of an area other than the area where the fixed shelf 610 is placed. The mobile manipulator 100 or the movable shelf 630 may perform self-location estimation by detecting the marker 6301 with a sensor (e.g., a camera, etc.). In this case, the marker 6301 is placed at least on the floor surface of all aisles that can become empty by the movement of the movable shelf 630.

[0109] According to such a configuration, the marker 6301 can be detected no matter how the movable shelf 630 moves.

[0110] Although the embodiments of the present invention have been described above, the above embodiments merely show some of the application examples of the present invention, and the technical scope of the present invention is not limited to the specific configurations of the above embodiments. Moreover, the above embodiments can be appropriately combined within a range where no contradiction occurs. [Industrial Applicability]

[0111] The present invention can be used in industries that manufacture robots and the like. [Explanation of symbols]

[0112] 100 Mobile manipulator (transport robot) 600 Warehouse 610 Fixed shelf 630 Mobile Shelf 650 Cage car 700 WCS Server 800 WMS Servers 900 Object Transport System

Claims

1. a fixed shelf fixed in place; A movable shelf that is moved by a first moving means of a trackless type; a transport robot that moves along a path including a passage defined by the fixed shelf and / or the movable shelf by a second moving means of a trackless type, and transports an object to or from the fixed shelf or the movable shelf; A movable shelf control unit that controls the movement of the movable shelf; A transport robot control unit that controls the movement of the transport robot; An object transport system comprising:

2. a path selection unit that selects a path into which the transport robot enters from paths defined by the fixed shelf and / or the movable shelf; A movement path generating unit that generates a movement path of the transport robot based on the selected passage, The object transport system according to claim 1 , wherein the transport robot control unit controls the movement of the transport robot based on the movement path.

3. The path selection unit further includes: an accessible passage determination unit that determines an accessible passage; an empty passage identification unit that identifies an empty passage in which the movable shelf does not exist among the accessible passages; an empty passage selection unit that selects the empty passage as the passage through which the transport robot enters when the transport robot can achieve a predetermined purpose in the empty passage; a movement command unit that, when the transport robot cannot achieve the objective in the empty passage, selects the passage to enter from the occupied passage in which the movable shelf exists so that the transport robot can achieve the objective, and issues a movement command to the movable shelf to vacate the occupied passage; The object transport system according to claim 2 , wherein the movable shelf control unit controls the movement of the movable shelf based on the movement command.

4. The object transport system according to claim 3 , wherein the accessible passage determination unit determines that a passage into which another transport robot has entered or is scheduled to enter is not accessible.

5. The purpose is that the transport robot picks up and transports a target object stored on the fixed shelf or the movable shelf, The path selection unit further includes: The object transport system according to claim 3 , further comprising a target object presence region selection unit that selects one region containing the target object from one or more regions set to contain one or more of the passages.

6. the purpose is that the transport robot replenishes articles to a target vacant position on the fixed shelf or the movable shelf, The path selection unit further includes: The object transport system according to claim 3 , further comprising a target vacant position existing area selection unit that selects one area including the target vacant position from one or more areas set to include one or more of the passages.

7. 3. The object transport system according to claim 2, wherein when the passage through which the transport robot enters is selected, the passage is reserved to prohibit other transport robots from entering the passage.

8. The transport robot control unit further an area selection unit that selects one area in which the transport robot can achieve a predetermined goal from one or more areas that are set to include one or more passages defined by the fixed shelf and / or the movable shelf; a passage selection unit that selects a passage into which the transport robot enters from the passages included in the area; a movement path generating unit that generates a movement path of the transport robot based on the selected path, The object transport system according to claim 1 , wherein the transport robot control unit controls the movement of the transport robot based on the movement path.

9. The object transport system of claim 8 , wherein each of said regions includes one of said passageways.

10. The object transport system of claim 8 , wherein each of the regions is defined by locating a fixed shelf at an end thereof.

11. The movable shelf further includes: A sensor for detecting a surrounding environment; A recognition unit that performs recognition processing based on an output of the sensor and generates a recognition result; A position estimation unit that estimates a self-position of the movable shelf based on the recognition result, The object transport system according to claim 1 , wherein the movable shelf control unit controls the movement of the movable shelf based on the estimated self-position.

12. The object transport system of claim 11 , wherein the sensor is a LiDAR device.

13. The movable shelf further includes: Multiple wheels and A plurality of motors for driving the wheels; a plurality of drive units for driving the respective motors; The object transport system according to claim 1 , wherein each of the drive units is connected in series by a communication line.

14. The transport robot further includes: An object manipulation unit that picks up or places an object; The object transport system according to claim 1 , further comprising: a displacement mechanism that displaces the object manipulation unit.

15. The transport robot further includes: A sensor for detecting a surrounding environment; A recognition unit that performs recognition processing based on an output of the sensor and generates a recognition result; a position estimation unit that estimates a self-position of the transport robot based on the recognition result, The object transport system according to claim 1 , wherein the transport robot control unit controls movement of the transport robot based on the self-position.

16. The object transport system according to claim 15 , wherein the sensor is a LiDAR device arranged on the transport robot so as to be capable of detecting a position higher than the height of the fixed shelf and the movable shelf.

17. the sensor is a camera; The object transport system according to claim 15 , wherein the recognition unit recognizes a marker placed on a floor surface in an area where the transport robot can enter, based on an image acquired from the camera.

18. a fixed shelf fixed in place; A movable shelf that is moved by a first moving means of a trackless type; a transport robot that moves along a route including a passage defined by the fixed shelf and / or the movable shelf by a trackless second moving means and transports an object to or from the fixed shelf or the movable shelf, A movable shelf control step of controlling the movement of the movable shelf; a transport robot control step of controlling movement of the transport robot; A control method comprising:

19. a fixed shelf fixed in place; A movable shelf that is moved by a first moving means of a trackless type; and a transport robot that moves along a route including a passage defined by the fixed shelf and / or the movable shelf by a trackless second moving means and transports an object to or from the fixed shelf or the movable shelf, the control program for the object transport system including the transport robot being programmed to a computer, A movable shelf control step of controlling the movement of the movable shelf; a transport robot control step of controlling movement of the transport robot; A control program that executes the above.

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