Mobile robot, control method and control program

Abstract

To improve productivity (or throughput) while enabling safe movement of a mobile robot on a passage and the like.SOLUTION: A mobile robot includes: a movement mechanism section; an end effector to hold or release an object; an operation device for making the end effector perform translational movement and rotational movement; and a control section for controlling the movement mechanism section, the end effector and the operation device. While the mobile robot is moving to a target point via the movement mechanism section, the control section performs control so as to transition a reference point configured for the end effector to an intermediate position and an intermediate posture that are intermediate position and attitude between a target position and a target attitude of the reference point, and that prevent a portion of the mobile robot from deviating from the width or the turning diameter of the mobile robot. After movement to the target point, the control section performs control so as to transition the reference point to the target position and the target attitude.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a robot, and more particularly to a robot that transports objects in a warehouse or the like. [Background technology]

[0002] In recent years, robots have become known that transport objects within a warehouse, etc. For example, Patent Document 1 discloses a mobile robot that transports objects within a warehouse. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-227955 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, when a transport robot moves within a warehouse or the like, it needs to move between obstacles such as shelves, walls, etc. Conventional mobile robots, such as those shown in Patent Document 1, avoid collisions with the environment by detecting obstacles and taking avoidance actions in advance.

[0005] However, in conventional transport robots, attention has been focused only on the safety of movement, and there has been insufficient consideration given to productivity or throughput, where productivity or throughput refers to the efficiency of, for example, the number of objects picked, transported, or dropped per unit time.

[0006] The present invention has been made in view of the above-mentioned technical background, and its purpose is to improve productivity (or throughput) while enabling safe movement of a mobile robot in a passageway or the like. [Means for solving the problem]

[0007] The above-mentioned technical problems can be solved by a robot, a control method, a system, etc. having the following configurations.

[0008] In other words, the mobile robot of the present invention is a mobile robot comprising a moving mechanism, an end effector that holds or releases an object, an operating device that moves the end effector in a translational and rotational manner, and a control unit that controls the moving mechanism, the end effector, and the operating device, wherein while the mobile robot is moving to a target point by the moving mechanism, the control unit controls the transition of a reference point set on the end effector to an intermediate position and intermediate posture between the target position and target posture of the reference point and such that no part of the mobile robot deviates from the width or turning diameter of the mobile robot, and after movement to the target point, the control unit controls the transition of the reference point to the target position and target posture.

[0009] With this configuration, the reference point set on the end effector can be shifted to an intermediate position / posture in advance while the mobile robot is moving, so that the end effector can be shifted to the target position / posture immediately after the movement. At this time, the intermediate position / posture is determined so that no part of the mobile robot deviates from the width or turning diameter of the mobile robot. In other words, productivity (or throughput) can be improved while the mobile robot can move safely in a passageway, etc. [Effects of the Invention]

[0010] According to the present invention, it is possible to improve productivity (or throughput) while enabling safe movement of a mobile robot in a passageway or the like. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a perspective view showing the overall configuration of a mobile manipulator. [Figure 2] FIG. 2 is an enlarged perspective view of the object manipulation unit. [Figure 3] FIG. 3 is a plan view of the mobile manipulator. [Figure 4] FIG. 4 is a functional block diagram of the mobile manipulator. [Figure 5] FIG. 5 is a flowchart showing the operation of the moving mobile manipulator. [Figure 6] FIG. 6 is a perspective view of the exterior of the mobile manipulator with the TCP in the initial position and initial posture. [Figure 7] FIG. 7 is a perspective view of the exterior of the mobile manipulator when the TCP is in the target position and target posture. [Figure 8] FIG. 8 is a perspective view of the appearance of the mobile manipulator when the TCP is in an intermediate position and an intermediate posture. [Figure 9] FIG. 9 is an explanatory diagram showing an example of a method for determining an intermediate position and an intermediate posture. [Figure 10] FIG. 10 is an explanatory diagram of a series of operations of the mobile manipulator moving between shelves. [Figure 11] FIG. 11 is an explanatory diagram showing an example in which a part of the mobile manipulator deviates from the width. [Figure 12] FIG. 12 is a schematic plan view of a mobile manipulator moving through a passage that turns at a right angle. [Figure 13] FIG. 13 shows a modified example in which a predetermined margin is provided with respect to the standard. [Figure 14] FIG. 14 is a schematic plan view of a mobile manipulator employing differential two-wheel motion. DETAILED DESCRIPTION OF THE INVENTION

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0013] (1. First embodiment) As a first embodiment, an example will be described in which the present invention is applied to a mobile robot used in an object transportation system installed in a warehouse, that is, a mobile manipulator 100. Note that the facilities to which the object transportation system is applied are not limited to warehouses, but include any facilities where similar functions are required.

[0014] (1.1 Configuration of the mobile manipulator) 1 is an external perspective view showing the overall configuration of a mobile manipulator 100 according to this embodiment. A coordinate system consisting of three mutually orthogonal axes (x-axis, y-axis, and z-axis) is displayed in the lower right 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 right direction, the negative direction as the left direction, the positive direction of the z-axis as the upward direction, and the negative direction as the downward direction.

[0015] As is clear from the figure, the mobile manipulator 100 comprises a main body 10 having an overall shape of a roughly rectangular parallelepiped with long sides in the vertical direction, an articulated robot arm 30 attached to the top end (or top surface) of the main body 10, and an object manipulation unit 50 attached to the tip of the articulated robot arm 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 articulated robot arm 30 and the object manipulation unit 50 are referred to separately, but they may also be referred to collectively, for example, simply as an articulated robot arm or an operating device.

[0016] 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.

[0017] This configuration provides a good left-right weight balance for the mobile manipulator 100. Furthermore, the left-right width of the mobile manipulator 100 can be made smaller than when the articulated robot arm unit 30 is attached to the side.

[0018] On the front surface of the main body 10, object storage sections 15 (15-1, 15-2, ... 15-7 from the top), each having seven rectangular parallelepiped spaces for storing objects, are aligned vertically with their openings facing forward. Each space of the object storage sections 15 is large enough to store at least one object.

[0019] With this configuration, the object storage unit 15 has multiple storage spaces, so multiple objects can be transported simultaneously. In addition, the spaces for storing objects are arranged vertically, so the width of the mobile manipulator 100 can be reduced. This allows it to move through narrow passages, etc.

[0020] The articulated robot arm unit 30 is attached above (vertically above) the object storage unit 15.

[0021] According to this configuration, the articulated robot arm unit 30 can be used to access the object storage unit 15 from above.

[0022] 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 at a position higher than the main body 10 and in a manner that allows detection from a position higher than surrounding shelves, etc. The LiDAR device 13 is, for example, a LiDAR unit, etc., and can detect the distance, position, shape, etc. of an object.

[0023] With this configuration, sensing can be performed from a high position using the LiDAR device 13. This makes it possible to estimate the self-position even when various obstacles exist in the surroundings.

[0024] The bottom surface of the main body 10 is provided with a moving mechanism 20 consisting of two differential wheels (w1, w2) that are controlled and driven independently on the left and right sides. In addition, passive wheels w' that rotate passively are arranged at the four corners of the bottom surface.

[0025] With this configuration, a low-cost moving mechanism can be realized by utilizing the differential two wheels.

[0026] In this embodiment, the articulated robot arm unit 30 has four rotationally driven joints (J1 to J5). One end (or base end) of a rod-shaped first link 31 is rotatably and swingably connected to the upper end (or top surface) of the main body unit 10 via the first joint (J1). In this case, the rotation center axis of the first joint (J1) is perpendicular to the floor surface, and the rotation center axis of the second joint (J2) is a horizontal axis (or pitch axis) extending in the left-right direction.

[0027] 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 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.

[0028] One end (base end) of the third link 33, which is shorter and bent 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 fourth joint (J4). At this time, the rotation center axis of the fourth joint (J4) is a horizontal axis (or pitch axis) extending in the left-right direction.

[0029] With this configuration, the hand position of the third link 33 can be freely positioned, thereby increasing the degree of freedom in the positioning of the object manipulation unit 50.

[0030] The object manipulator 50 is rotatably attached via a fifth joint (J5) to the tip of the third link 33. The rotation center axis of the fifth joint (J5) is parallel to the normal to the top surface of the object manipulator 50, and in the example shown in the figure, is parallel to the vertical axis.

[0031] In this embodiment, the object manipulator 50 has two drive joints (J6 to J7).

[0032] 2 is an enlarged perspective view of the exterior of object manipulator 50. In this embodiment, object manipulator 50 has a roughly U-shaped base body 51 that is laid on its side in the figure. A slide member 52 is slidably attached to one side of the bottom surface of base body 51 via a first linear joint (JL1) (or sixth joint (J6)). An end effector 53 is attached to the top surface of slide member 52.

[0033] In this embodiment, the end effector 53 is a gripper equipped with 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) are interlocked and form a second linear joint (JL2) (or seventh joint (J7)). The left and right claws (55L, 55R) are equipped with sensors (not shown) that detect contact or force.

[0034] A first camera 56 is provided on the upper part of the base body 51 and is oriented in an axial direction parallel to the first linear axis (JL1). The first camera 56 has, for example, a function as an RGB camera and a function as a ToF (Time of Flight) camera. This first camera 56 can be used to recognize markers, objects, and the space (gaps) surrounding the objects.

[0035] A distance sensor 58 is provided near the center of the end effector 53, i.e., the gripper, and is oriented in the axial direction parallel to the first linear axis (JL1). By using this distance sensor 58, the relative distance between the object and the gripper can be detected. This makes it possible to detect whether slippage occurs between the object and the jaws 55 when gripping the object.

[0036] A second camera 57 is provided directly above the distance sensor 58 and oriented in an axial direction parallel to the first linear axis (JL1). The second camera 57 is, for example, a monochrome camera, and captures an image of an identifier such as a barcode attached to an object. Based on this captured image, for example, an identification or recognition process 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.

[0037] 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 other known sensors may also be employed.

[0038] 3 is a plan view of mobile manipulator 100 according to this embodiment. In this figure, mobile manipulator 100 has object manipulation unit 50 oriented such that its longitudinal axis is perpendicular to the direction of travel of mobile manipulator 100. As is clear from this figure, the longitudinal length L of object manipulation unit 50 is configured to be greater than the left-right width W of main body 10.

[0039] 4 is a functional block diagram of the mobile manipulator 100. As is clear from the diagram, the mobile manipulator 100 includes a control unit 101, a memory 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.

[0040] The control unit 101 is a computing device such as a CPU, and executes various processes described below according to programs read from the storage unit 102. The storage unit 102 is a storage device such as a ROM, RAM, or 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 external devices. The LiDAR device 13 is a sensor unit that acquires the distance, position, shape, etc. of the environment. The acquired information is stored in the storage unit 102, etc., and used by the control unit 101.

[0041] 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.

[0042] The moving mechanism unit 20 is a trackless moving mechanism that does not require rails or the like, and is equipped with a wheel drive unit, which is a drive circuit for driving the drive wheels (w1, w2), and a wheel sensor that detects the rotation state of the drive wheels (w1, w2). Information detected via the sensor is stored in the memory unit 102 or used by the control unit 101.

[0043] The object manipulator 50 is equipped with a claw driver to drive the joint (JL2) associated with the interlocking left and right claws (55L, 55R). It also has a linear axis driver as a drive circuit to drive the first linear joint (JL1). Additionally, the object manipulator 50 is equipped with a sensor to detect force or contact acting on the claws 55.

[0044] 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 through the sensors is stored in the memory unit 102 or used by the control unit 101.

[0045] The above configuration is an example, and various additions, changes, deletions, etc. may be made to the configuration. It may be modified to have the following configuration.

[0046] (1.2 Mobile Manipulator Operation) FIG. 5 is a flowchart showing the operation of the mobile manipulator 100 during movement.

[0047] As is clear from the figure, when the process starts, the control unit 101 performs a process of acquiring the target position and target posture of the movement of the mobile manipulator 100 from the memory unit 102 or from the outside via the communication unit 103 (S11).

[0048] After acquiring the target position and orientation for movement, the control unit 101 performs processing to acquire the target position and orientation of a control point defined for the object manipulator 50 or the articulated robot arm unit 30 (S12). In this embodiment, the control point is a tool center point (TCP), which is set at the tip of the object manipulator 50.

[0049] After the process of acquiring the target position and target posture of the TCP, the control unit 101 performs a process of generating an intermediate position and intermediate posture of the TCP based on the initial position and initial posture of the TCP and the target position and target posture of the TCP (S13). The intermediate position and intermediate posture are intermediate positions and postures between the initial position and initial posture of the TCP and the target position and target posture of the TCP. In addition, the intermediate position and intermediate posture are positions and postures such that a part of the mobile manipulator 100 does not deviate from the width of the mobile manipulator 100 in the left-right direction.

[0050] 6 is a perspective view of the exterior of the mobile manipulator 100 with the TCP in its initial position and initial posture. In this figure, point P1 indicates the initial position of the TCP. As is clear from this figure, the articulated robot arm unit 30 is folded, and the longitudinal axis of the first sliding member 52 is also parallel to the front-to-rear axis of the mobile manipulator 100. In other words, all of the components of the mobile manipulator 100, including the articulated robot arm unit 30, are contained within the width W of the mobile manipulator in the left-to-right direction.

[0051] 7 is a perspective view of the exterior of the mobile manipulator 100 when the TCP is in a target position and a target posture. Figure 7(a) is a perspective view of the exterior of the mobile manipulator 100 when the TCP is in a target position and a target posture, and Figure 7(b) is a plan view of the mobile manipulator 100 when the TCP is in a target position and a target posture.

[0052] In the figure, the current position (point P1) of the TCP coincides with the target position (point P3) and the target posture. At this time, the longitudinal axis of object manipulator 50 is perpendicular to the front-to-rear direction of mobile manipulator 100, and the length of object manipulator 50 is greater than the width W of mobile manipulator 100 in the left-to-right direction.

[0053] 8 is a perspective view of the exterior of the mobile manipulator 100 when the TCP is in an intermediate position and intermediate posture. Figure 8(a) is a perspective view of the exterior of the mobile manipulator 100 when the TCP is in an intermediate position and intermediate posture, and Figure 8(b) is a plan view of the mobile manipulator 100 when the TCP is in an intermediate position and intermediate posture.

[0054] As is clear from the figure, the current position (point P1) of the TCP coincides with the intermediate position (point P2) and the intermediate posture. At this time, the longitudinal axis of object manipulation unit 50 is parallel to the front-to-rear direction of mobile manipulator 100, and the entire configuration fits within the width W of mobile manipulator 100 in the left-to-right direction.

[0055] Here, an example of a method for determining the intermediate position and the intermediate posture will be described with reference to FIG.

[0056] 9 is an explanatory diagram showing an example of a method for determining an intermediate position and an intermediate posture. In this embodiment, the position x1 in the front-rear direction (x direction) of the intermediate position (point P2) is set to an appropriate position between the initial position and the target position so as not to cause self-collision with the articulated robot arm unit 30 (x1 in FIG. 9(a)).

[0057] According to this configuration, by devising the position of the transition target, it is possible to prevent self-interference in the mobile robot.

[0058] Furthermore, the position (y1) in the left-right direction of the intermediate position (point P2) is located at the center of the mobile manipulator 100 in the left-right direction (y1 in FIG. 1(b)).

[0059] With this configuration, the neutral position can be used as an intermediate position, making it easy to transition to the target position.

[0060] The height of the intermediate position (point P2) is basically set to the same height as the target position (point P3). However, if the height of the target position (point P3) is greater than the upper height limit (H1), the height of the intermediate position is set to the upper height limit (H1) (H1 in FIG. 1(a)). On the other hand, if the height of the target position (point P3) is less than the lower height limit (H2), the height of the intermediate position is set to the lower height limit (H2) (H2 in FIG. 1(a)). In this case, both the upper height limit (H1) and the lower height limit (H2) are set to heights that prevent the articulated robot arm unit 30 and / or the object manipulation unit 50 from interfering with the mobile manipulator 100.

[0061] With this configuration, while the intermediate position (point P2) is basically set to the same height as the target position (point P3), if the target position is higher or lower than a certain limit (a position far from the base of the articulated robot arm unit 30), self-interference can be prevented by limiting it to an upper limit value (H1) or a lower limit value (H2), respectively.

[0062] After the process of generating the intermediate positions and intermediate postures, the mobile manipulator 100 controls the movement mechanism unit 20 to perform a process of starting autonomous movement (S15). This autonomous movement is performed while estimating its own position using the LiDAR device 13.

[0063] Furthermore, when the autonomous movement is started, the control unit 101 controls the articulated robot arm unit 30 to start a process of transitioning the TCP from the initial position and initial posture to an intermediate position and intermediate posture (S16). This transition process can be realized by various known methods. For example, the transition may be performed by calculating the amount of joint displacement using inverse kinematics. At this time, the object manipulation unit 50 may be controlled together with the articulated robot arm unit 30.

[0064] The mobile manipulator 100 continues to move until the position and posture of the mobile manipulator 100 reach the movement target position and posture (S17 NO). During this time, the TCP transition process to the intermediate position and intermediate posture is also being performed. In this embodiment, the transition process to the intermediate position and intermediate posture is completed before the movement is completed. When the mobile manipulator 100 reaches the movement target position and posture (S17 YES), the control unit 101 performs a process to stop the movement mechanism unit 20 (S18).

[0065] After the movement stop processing, the control unit 101 performs a stop processing of the articulated robot arm unit 30 (S19). Note that if the TCP reaches an intermediate position or intermediate posture before the movement of the mobile manipulator 100 stops, this processing may be omitted by performing the stop processing of the articulated robot arm unit 30 together with the arrival at the intermediate position or intermediate posture.

[0066] After stopping the articulated robot arm unit 30, the mobile manipulator 100 controls the articulated robot arm unit 30 to transition the TCP from the intermediate position and intermediate posture to the target position and target posture (S21). This transition process can be realized by various known methods. For example, the transition may be performed by calculating the joint displacement amount using inverse kinematics. At this time, the object manipulation unit 50 may be controlled together with the articulated robot arm unit 30. The process then ends.

[0067] Figure 10 is an explanatory diagram of a series of operations of the mobile manipulator 100 moving between shelves. Figure 10(a) is an explanatory diagram of the mobile manipulator 100 in its initial state immediately before movement. Figure 10(b) is an explanatory diagram of the mobile manipulator 100 in an intermediate posture immediately after movement is completed. Figure 10(c) is an explanatory diagram of the mobile manipulator 100 in a state where the TCP has transitioned to the target position and target posture.

[0068] Figure 6(a) shows the mobile manipulator 100 in its initial state immediately before the start of autonomous movement (S15). At this time, the mobile manipulator 100 is located between the foremost shelf 201 and the second shelf 202 from the front. The posture of the mobile manipulator 100 is the initial posture shown in Figure 6. Note that the foremost shelf 201 is shown with dashed lines, with the shelf boards and backboard omitted, so that the mobile manipulator 100 can be easily seen (the same applies to Figures 6(b) and (c)).

[0069] 10(b) shows the mobile manipulator 100 immediately after the articulated robot arm unit 30 has stopped (S19) after the mobile manipulator 100 has reached the target position and posture. At this time, the mobile manipulator 100 is in the intermediate posture shown in FIG.

[0070] 7(c) shows the mobile manipulator 100 immediately after the TCP has completed the transition (S21) to the target position and target posture. At this time, the mobile manipulator 100 is in the target posture shown in FIG.

[0071] With this configuration, the TCP can be transitioned to an intermediate position and intermediate posture in advance while the mobile manipulator 100 is moving, so that the end effector can be transitioned to the target position and target posture immediately after the movement. At this time, the intermediate position and intermediate posture are determined so that a part of the mobile manipulator 100 does not deviate from the width of the mobile robot. In other words, productivity (or throughput) can be improved while enabling the mobile robot to move safely in a passageway or the like.

[0072] (2. Modifications) The present invention can be implemented in various modifications.

[0073] In the above-described embodiment, no particular constraints are placed on the transition process of the TCP from the initial position / posture to an intermediate position / posture. However, during the transition process of the TCP, a part of the articulated robot arm unit 30 or the object manipulation unit 50 may deviate from the width of the mobile manipulator in the left-right direction.

[0074] 11A and 11B are explanatory diagrams showing examples in which a portion of the mobile manipulator 100 deviates from the width W. FIG. 11A is a plan view showing a first example, and FIG. 11B is a plan view showing a second example. In the example of FIG. 11A, a portion of the object manipulation unit 50 deviates from the width of the main body unit 10. In addition, in the example of FIG. 11B, the area around the second joint (J2) of the articulated robot arm unit 30 deviates from the width of the main body unit 10.

[0075] To avoid these situations, certain constraints may be imposed on joint angles and the like in the calculation of inverse kinematics during the transition process.

[0076] According to this configuration, safety can be improved even during the transition of the position and posture of the TCP, and the safety of movement can be further improved.

[0077] In the above-described embodiment, the deviation from the width is used as the criterion, but the present invention is not limited to such a configuration. For example, the deviation from the width may be used as the criterion.

[0078] 12 is a schematic plan view of mobile manipulator 100 moving through a passage formed by walls, shelves, or the like, that bends at right angles. As shown in the figure, when mobile manipulator 100 needs to turn because the passage is not linear or the like, it is necessary to operate drive units such as object manipulation unit 50 and articulated robot arm unit 30 within a range that does not exceed the turning diameter. Therefore, intermediate positions and intermediate postures may be set based on the turning diameter so that no part of mobile manipulator 100 deviates. The same applies to the operating range during transitions.

[0079] In the above embodiment, it has been explained that in the initial state, all parts constituting the mobile manipulator 100, including the articulated robot arm unit 30, fit within the width W in the left-right direction of the mobile manipulator (FIG. 6). However, it is not always the case that all parts constituting the mobile manipulator 100 fit within the width W in the left-right direction of the mobile manipulator.

[0080] Therefore, for example, before the process of starting autonomous movement (S15), the control unit 101 determines whether all parts constituting the mobile manipulator 100 fit within the width W in the left-right direction of the mobile manipulator, and if all parts fit within the width (or turning diameter) of the mobile manipulator 100, autonomous movement can be started as is, while if not, the articulated robot arm unit 30 and / or object manipulation unit 50 can be controlled so that all parts fit within the width (or turning diameter) of the mobile manipulator 100 before autonomous movement can be started.

[0081] With this configuration, it is possible to move only after ensuring safety.

[0082] In the above-described embodiment, the width (or turning diameter) of the mobile manipulator 100 is used as a reference for the intermediate positions and postures or the process leading to them, but the present invention is not limited to such a configuration. Therefore, a certain margin may be provided in the width.

[0083] Figure 13 shows modified examples in which a predetermined margin is provided relative to the reference. Figure 13(a) shows an example in which a certain margin ((W-W1) / 2) is provided on the left and right sides of the width of the mobile manipulator 100. Figure 13(b) shows an example in which a certain margin (D-D1) is provided relative to the turning diameter.

[0084] Such a configuration can further improve safety.

[0085] In the above-described embodiment, a differential two-wheel system is used as the movement mechanism 20. When a differential two-wheel system is used, there is a risk that the translation direction may deviate slightly left and right due to a deviation in the self-position estimation. Therefore, the reference region for controlling the articulated robot arm 30 and / or the object manipulation unit 50 may be set taking this deviation into consideration.

[0086] 14 is a schematic plan view of a mobile manipulator 100 that employs two differential wheels. As is clear from the figure, when considering translational vibration, the area (area T) enclosed by a triangle in the plan view of the figure (particularly an isosceles triangle in the example shown) can be set as an area with a low probability of collision with the environment. Therefore, the articulated robot arm unit 30 and / or the object manipulation unit 50 may be controlled so as not to deviate from this area T.

[0087] With this configuration, safe movement is possible even when there is a translational shake or the like caused by a deviation in self-position estimation or the like.

[0088] In the above-described embodiment, the process of generating an intermediate position and an intermediate posture (S13) is performed uniformly regardless of the position of the mobile manipulator 100, but the present invention is not limited to such a configuration. Therefore, for example, the process of generating an intermediate position and an intermediate posture may be performed only when it is determined that the current position of the mobile manipulator 100 is in a predetermined passage surrounded by shelves or the like.

[0089] With this configuration, processing can be executed only when necessary, such as when moving within a relatively small area.

[0090] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and the technical scope of the present invention is not intended to be limited to the specific configurations of the above embodiments. Furthermore, the above embodiments can be combined as appropriate within the scope of not causing any contradiction. [Industrial Applicability]

[0091] The present invention can be used in industries that manufacture robots and the like. [Explanation of symbols]

[0092] 10 Main body 20 Transition Mechanism 30 Articulated robot arm 50 Object operation section 100 Mobile Manipulator

Claims

1. A moving mechanism unit; an end effector for holding or releasing an object; an operating device for translating and rotating the end effector; a control unit that controls the movement mechanism unit, the end effector, and the operating device; A mobile robot comprising: The control unit A mobile robot in which, while the mobile robot is moving to a target point by the movement mechanism, the reference point set on the end effector is controlled to transition to an intermediate position and intermediate posture between the target position and target posture of the reference point and such that no part of the mobile robot deviates from the width or turning diameter of the mobile robot, and after movement to the target point, the reference point is controlled to transition to the target position and target posture.

2. 2. The mobile robot according to claim 1, wherein the control unit further controls the mobile robot so that no part of the mobile robot extends beyond a width or turning diameter of the mobile robot during the transition to the intermediate position and intermediate posture.

3. 2. The mobile robot according to claim 1, wherein the intermediate position in the longitudinal direction of the mobile robot is set so as to prevent self-interference of the mobile robot.

4. The mobile robot according to claim 1 , wherein the intermediate position is a widthwise center of the mobile robot.

5. The height direction position of the mobile robot at the intermediate position is If the target position is greater than a first height, the target position is set to the first height; When the target position is smaller than a second height that is lower than the first height, the target position is set to the second height; The mobile robot according to claim 1 , wherein in other cases, the target position is set to the height.

6. 6. The mobile robot according to claim 5, wherein the first height and the second height are both set so that the end effector and / or the operating device do not interfere with the mobile robot.

7. 2. The mobile robot according to claim 1, wherein the control unit further controls the end effector or the operating device and the movement mechanism unit so that, if a portion of the end effector or the operating device deviates from a width or turning diameter of the mobile robot at the time of starting movement to the target point, the end effector or the operating device is brought into a state where a portion of the end effector or the operating device is inside the width or turning diameter before starting movement.

8. The mobile robot of claim 1 , wherein the reference point is a tool center point.

9. The operating device is an articulated robot arm; a table attached to a tip of the articulated robot arm, movable linearly, and capable of placing the object thereon; The mobile robot of claim 1 , wherein the end effector is attached to the table and moves linearly therewith.

10. The mobile robot of claim 9 , wherein the end effector is a gripper.

11. 2. The mobile robot according to claim 1, wherein the intermediate positions and the intermediate postures are determined within a range that is narrower by a predetermined margin than a range within which a part of the mobile robot does not deviate from the width or turning diameter of the mobile robot.

12. The moving mechanism unit includes two differential wheels, 2. The mobile robot according to claim 1, wherein the intermediate position and the intermediate posture are determined so that the end effector and the operating device are within a triangular range with the mobile body allowable angle as the apex angle and the front of the mobile robot in the translational direction as the base when the mobile robot is viewed from above.

13. Equipped with LiDAR, The mobile robot according to claim 1 , wherein the control unit performs a self-position estimation process based on information obtained from the LiDAR.

14. The mobile robot according to claim 1 , wherein the control unit executes the process of transitioning to the intermediate position and the intermediate posture only when the mobile robot moves in an area surrounded by a shelf or a wall.

15. A moving mechanism unit; an end effector for holding or releasing an object; an operating device for translating and rotating the end effector; a control unit that controls the movement mechanism unit, the end effector, and the operating device; A method for controlling a mobile robot, comprising: a step of controlling, while the mobile robot is moving to a target point by the movement mechanism unit, the reference point set on the end effector to transition to an intermediate position and intermediate posture between the target position and target posture of the reference point, such that a part of the mobile robot does not deviate from the width or turning diameter of the mobile robot; a step of controlling the reference point to transition to the target position and the target attitude after the movement to the target point; A control method comprising:

16. A moving mechanism unit; an end effector for holding or releasing an object; an operating device for translating and rotating the end effector; a control unit that controls the movement mechanism unit, the end effector, and the operating device; A control program for a mobile robot, comprising: a step of controlling, while the mobile robot is moving to a target point by the movement mechanism unit, the reference point set on the end effector to transition to an intermediate position and intermediate posture between the target position and target posture of the reference point, such that a part of the mobile robot does not deviate from the width or turning diameter of the mobile robot; a step of controlling the reference point to transition to the target position and the target attitude after the movement to the target point; A control program comprising:

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