Gripping method using multi-joint gripper and gripping device

Abstract

A gripping method according to an embodiment of the present invention relates to a gripping method that is performed by a control unit provided with a processor, and uses a multi-joint gripper including a multi-joint arm unit and a gripping unit having a plurality of fingers. The gripping method may comprise the steps of: determining an object to be gripped by analyzing an image acquired using an optical sensor; determining the trajectory of the multi-joint arm unit on the basis of the position of the object to be gripped; determining the gripping pose of the gripping unit on the basis of the object to be gripped; and performing gripper control on the basis of the trajectory and the gripping pose.

Description

Gripping method and gripping device using a multi-joint gripper

[0001] The present invention relates to a gripper gripping method and device, and is a technology related to a gripping method capable of picking a gripping target object using a multi-joint gripper and a gripping device that performs gripping based on the method.

[0002] Gripping algorithms using grippers play a crucial role in robotics. They can encompass a series of procedures and techniques that help robots stably grasp and manipulate objects. Typically, a grasping algorithm considers the object's shape, size, weight, and surface condition to find an appropriate gripping point, and then adjusts the gripper angle to secure contact area and friction. This process can utilize technologies such as object modeling, environmental perception, real-time processing of sensor data, and path planning.

[0003] Existing gripping algorithms using grippers have primarily been developed for grippers with simple structures and operating principles. While these algorithms are advantageous for reliably grasping objects with relatively regular and predictable shapes, they have limitations in handling complex or irregularly shaped objects. Furthermore, the limited degrees of freedom of existing grippers hinders their adaptability in diverse environments and the sophisticated manipulation required to grasp a variety of objects. This presents limitations in environments requiring more complex and precise manipulation.

[0004] The development of multi-joint grippers with human-like fingers opens up new possibilities for overcoming these limitations. These new grippers, with multiple joints and flexibility like the human hand, can grasp more complex and diverse objects, enabling even finer manipulations. Consequently, the development of new grasping algorithms, designed to efficiently control the complex movements of human-like multi-joint grippers and adapt to a variety of objects and situations, is needed, going beyond existing rule-based algorithms.

[0005] In order to solve the above-mentioned problem, the present invention provides a gripping method and device that can grip various objects using a multi-joint gripper.

[0006] A gripping method according to one embodiment of the present invention is performed by a control unit provided as a processor, and relates to a gripping method using a multi-joint gripper including a gripping unit having a multi-joint arm unit and a plurality of fingers, and may include a step of analyzing an image acquired using a sensor to determine a gripping target object, a step of determining a movement trajectory of the multi-joint arm unit based on a position of the gripping target object, a step of determining a gripping posture of the gripping unit based on the gripping target object, and a step of performing gripper control based on the movement trajectory and the gripping posture.

[0007] In one embodiment, the step of determining the grip posture may include the step of determining which finger to use among a plurality of fingers and the step of determining the position of the finger to use.

[0008] In one embodiment, the step of determining which finger to use may be characterized by calculating a total grip area required to grip the grip target object.

[0009] In one embodiment, the step of determining which finger to use may be characterized by calculating the total gripping area based on at least one selected from the width of the gripping object, the size of the gripping object, and whether there is a collision with another object according to the relative position of the gripping object and the gripper.

[0010] In one embodiment, the step of determining the position of the finger may be characterized by determining a grip surface of a grip target object that the finger can contact, and determining the position of the finger based on the grip surface.

[0011] In one embodiment, the step of determining the position of the finger may be characterized by setting a direction in which the finger moves toward the gripping target object based on the gripping surface.

[0012] In one embodiment, the moving direction may be characterized by reverse gripping.

[0013] In one embodiment, the step of determining the grip posture may further include the step of determining the grip force of each finger.

[0014] In one embodiment, the gripper further includes an intake hole capable of absorbing a gripping target object through negative pressure, and the step of determining the gripping posture may further include a step of determining whether to use the intake hole.

[0015] In one embodiment, the step of determining the gripping posture may further include a step of performing a positional accuracy correction operation for correcting the Z-axis and Y-axis direction accuracy of the gripping target object.

[0016] In one embodiment, the step of determining the gripping posture may be characterized by determining the gripping posture based on a gripping posture preset in response to the gripping target object.

[0017] In one embodiment, the step of determining a movement trajectory of the multi-joint arm may include the step of determining a position of the gripping part based on a position of a gripping target object, the step of calculating possible movement trajectory candidates for moving the gripping part to a position of the gripping part based on a length and a rotatable angle of each joint of the multi-joint arm, and the step of determining a final movement trajectory based on a preset criterion among the movement trajectory candidates.

[0018] In one embodiment, the step of determining the position of the gripping part may be characterized by determining the position of the gripping part based on interference with other objects or walls around the gripping target object.

[0019] In one embodiment, the step of calculating the movement trajectory candidates may be characterized by determining whether a collision occurs with the gripper during movement along the movement trajectory, and excluding a movement trajectory in which a collision exists from the movement trajectory candidates.

[0020] In one embodiment, the step of determining the movement trajectory may be characterized by determining the final movement trajectory based on the time taken to move.

[0021] In one embodiment, the step of determining a gripping target object may include the steps of identifying an object in an acquired image, determining whether the identified object exists in pre-stored object data, and determining a gripping priority among the identified objects.

[0022] According to one embodiment, the pre-stored object data includes a pick point corresponding to each object, and the step of determining the grab priority may include the step of determining grabbable pick points among the pick points of the identified object, the step of calculating priorities among grabbable pick points, and the step of determining the grab priority based on the priorities of the grabbable pick points.

[0023] In one embodiment, the step of calculating the priority of the pick points may be characterized in that it is determined based on the height order of the absolute positions of the pick points.

[0024] In one embodiment, the gripping method may further include a step of determining whether gripper control is performed normally.

[0025] A gripping device according to another embodiment of the present invention relates to a gripping device using a multi-joint gripper including a gripping device having a multi-joint arm and a plurality of fingers, and includes a control unit that controls the operation of the multi-joint arm and the gripping device, wherein the control unit analyzes an image acquired using a sensor to determine a gripping target object, determines a movement trajectory of the multi-joint arm based on a position of the gripping target object, determines a gripping posture of the gripping device based on the gripping target object, and performs gripper control based on the movement trajectory and the gripping posture.

[0026] The gripping method and gripping device of the present invention can precisely and efficiently perform gripping operations suitable for objects and environments of complex and diverse shapes by controlling a multi-joint gripper.

[0027] Figure 1 is a block diagram of a multi-joint gripper according to one embodiment.

[0028] Figure 2 is a perspective view of a multi-joint gripper according to one embodiment.

[0029] Figure 3 is a flowchart of a method of phage production according to one embodiment of the present invention.

[0030] Figure 4 is a flowchart of a step for determining a target object to be grasped according to one embodiment.

[0031] Figure 5 is a flowchart of a step for determining a phage priority according to one embodiment.

[0032] Fig. 6 is a flowchart of a step for determining a movement trajectory of a multi-joint arm according to one embodiment.

[0033] Fig. 7 is a flowchart of a step for determining a grip posture according to one embodiment.

[0034] Figure 8 is a schematic diagram showing the direction of movement of a finger according to one embodiment.

[0035] The advantages and features of the present invention, and the methods for achieving them, will become clearer with reference to the embodiments described below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided solely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined solely by the scope of the claims.

[0036] The terms used in this specification will be briefly explained, and the present invention will be described in detail.

[0037] The terms used in this invention have been selected from widely used, current terms, taking into account the functions of the invention. However, these terms may vary depending on the intentions of those skilled in the art, precedents, the emergence of new technologies, etc. Furthermore, in certain cases, terms may be arbitrarily selected by the applicant, in which case their meanings will be described in detail in the relevant description of the invention. Therefore, the terms used in this invention should not be defined simply as names, but rather based on their inherent meanings and the overall content of the invention.

[0038] When a part of the specification is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise specifically stated. Furthermore, terms such as "part" and "module" used in the specification may refer to a unit that processes at least one function or operation.

[0039] Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily practice the present invention. In addition, in order to clearly describe the present invention in the drawings, parts that are not related to the description are omitted. Terms including ordinal numbers such as “first”, “second”, etc. may be used to describe various components, but the components are not limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component. The term “and / or” includes a combination of a plurality of related items or any one of a plurality of related items.

[0040]

[0041] Hereinafter, a method of phasing according to various embodiments of the present invention will be described with reference to the drawings.

[0042] The gripping method of the present invention is a technique relating to a gripping method capable of gripping an object using a multi-joint gripper (1).

[0043] Fig. 1 is a block diagram of a multi-joint gripper (1) according to one embodiment of the present invention, and Fig. 2 is a perspective view of a part of a multi-joint gripper (1) according to one embodiment.

[0044] Referring to FIG. 1, the multi-joint gripper (1) of the present invention may be composed of a gripping portion (10), a multi-joint arm portion (20), and a control portion (30) that can control them. The multi-joint gripper (1) of the present invention may include a gripping portion (10) that performs a motion of grabbing an object, including a finger (110), a multi-joint arm portion that is connected to the gripping portion (10) and is composed of a plurality of joints and can move the gripping portion (10) to a position required for the gripping motion, and a control portion (30) that can control the gripping portion (10) and the multi-joint arm portion (20).

[0045] The joints of the multi-joint arm (20) may mean unit modules that have multiple degrees of freedom and can rotate at various angles.

[0046]

[0047] The gripping unit (10) includes a plurality of fingers (110) and can grasp or release an object to be gripped. Here, the fingers (110) may refer to a finger device provided in a shape similar to a human finger (110) for gripping. Each finger (110) can be moved individually, thereby enabling precise gripping. The fingers (110) can be independently controlled, thereby enabling gripping of objects at various positions and angles.

[0048] According to one embodiment, as shown in FIG. 2, the finger (110) is composed of a plurality of joints, and more precise position control can be achieved by controlling the position of each joint.

[0049] According to one embodiment, the gripping part (10) may include an intake hole (130) capable of sucking a gripping target object through negative pressure. As illustrated in FIG. 2, the gripping part (10) may include an intake hole (130) in a finger (110). However, the position of the intake hole (130) is not limited thereto, and may be provided in other positions of the gripping part (10), such as a palm. The area of ​​the intake hole (130) may be shaped in various ways for each finger (110), and the intake hole (130) pad may also be formed in various shapes and materials. For example, the pad of the intake hole (130) may be a flat, deep, bellows, oval, ball joint pad, conductive pad, film adsorption pad, nozzle-type pad, sponge pad, etc., and the material of the intake hole (130) may be NBR (nitrile rubber), conductive NBR, silicone rubber, conductive silicone rubber, urethane rubber, FKM (fluoro rubber), CR (chloroprene rubber), EPDM (ethylene propylene rubber), silicone sponge, conductive silicone sponge, sponge, conductive sponge, etc. The shape and material of the pad of the intake hole (130) are not limited to the examples described above.

[0050]

[0051] The multi-joint arm (20) is connected to a section opposite to the section where the finger (110) of the gripper (10) is positioned, and is composed of a plurality of joints so that the gripper (10) can be moved to a position required for a gripping motion. Here, the joints may refer to unit modules that have multiple degrees of freedom and can rotate at various angles. That is, the multi-joint arm (20) is connected to a plurality of unit modules that can rotate at various angles, and the gripper (10) is connected to the end, so that each unit module can rotate to move the gripper (10) to a required position.

[0052]

[0053] The multi-joint gripper (1) of the present invention may additionally include an optical sensor. The optical sensor can acquire an image of the environment surrounding the gripper through optical photography.

[0054]

[0055] The control unit (30) can control the gripper (10) and the multi-joint arm (20). Specifically, the control unit (30) is electrically connected to the driving unit (50) existing in each component of the multi-joint gripper (1) to control the movement of each component, and is electrically connected to the driving unit (50) existing separately from each component to control the movement of the driving unit (50), thereby indirectly controlling the gripper (10) and the multi-joint arm (20).

[0056] Controlling the motion of the grip part (10) and the multi-joint arm part (20) may mean controlling the motion of each unit joint module of the finger (110) and the suction hole (130) included in the grip part (10) and the multi-joint arm part (20).

[0057] The control unit (30) can control the operation of the grip unit (10) and the multi-joint arm unit (20) according to the following gripping method, including the processor.

[0058] A processor may include one or more of a central processing unit (CPU), a graphic processing unit (GPU), a microcontroller unit (MCU), an application processor (AP), an electronic control unit (ECU), a microprocessor (Micom), or at least one other electronic device capable of performing various calculations and control processing. These processing or control devices may be implemented using, for example, one or more semiconductor chips, circuits, or related components, alone or in combination.

[0059] In addition, the control unit (30) may further include a memory. The control unit (30) may store various data and commands necessary for controlling the multi-joint gripper (1) including the memory.

[0060] The memory may be implemented as at least one of a main memory and an auxiliary memory. The main memory may be implemented using a semiconductor storage medium such as ROM and / or RAM, for example, and the auxiliary memory may be implemented based on a device capable of permanently or semi-permanently storing data, such as a flash memory device (such as a solid state drive (SSD)), a Secure Digital (SD) card, a hard disk drive (HDD), a compact disc, a DVD, or a laser disc.

[0061]

[0062] In addition, referring again to FIG. 1, the multi-joint gripper (1) may additionally include a driving unit (50), a sensor unit (40), a negative pressure generating unit (60), etc.

[0063] The driving unit (50) can transmit driving power to the gripper (10) and the multi-joint arm (20) as described above. The driving unit (50) can be provided with various power transmission sources such as a motor, hydraulic pressure, or pneumatic system to transmit power to each component of the gripper. The driving unit (50) can be provided separately, including the components described above, or can be provided in a form included in each component.

[0064] The sensor unit (40) can detect a gripping target object and acquire information within the range in which the gripper operates, including various types of sensors. The sensor unit (40) can typically include an optical sensor, but can also include various sensors such as a tactile sensor, an infrared sensor, an ultrasonic sensor, and a Lidar sensor. In the case of an optical sensor, the position, size, shape, etc. of an object can be identified by acquiring image information.

[0065] The negative pressure generating unit (60) can generate negative pressure in the intake hole (130) of the gripper unit (10). The negative pressure generating unit (60) can be provided with a pump or a blower, etc., to form negative pressure inside the intake hole (130), thereby creating a vacuum state at the contact surface with the surface of the object.

[0066]

[0067] Hereinafter, a method of phasing according to various embodiments of the present invention will be described with reference to FIGS. 3 to 8.

[0068] The gripping method of the present invention relates to a gripping method using a multi-joint gripper (1) including a gripping part (10) having a multi-joint arm part (20) and a plurality of fingers (110), and can be performed by a control part (30).

[0069] Figure 3 is a flowchart of a method of phasing according to one embodiment of the present invention.

[0070] Referring to FIG. 3, the gripping method of the present invention may include a step (S310) of analyzing an image acquired using a sensor to determine a gripping target object, a step (S320) of determining a movement trajectory of a multi-joint arm part (20) based on the position of the gripping target object, a step (S330) of determining a gripping posture of a gripping part (10) based on the gripping target object, and a step (S340) of performing gripper control based on the movement trajectory and gripping posture.

[0071]

[0072] <Determining the target object to be phaged>

[0073] Figure 4 is a flowchart of a step for determining a target object to be grasped according to one embodiment.

[0074] Referring to FIG. 4, a step (S310) of determining a grip target object according to one embodiment may include a step (S410) of identifying an object in an acquired image, a step (S420) of determining whether the identified object exists in pre-stored object data, and a step (S430) of determining a grip priority among the identified objects.

[0075] The step of determining the target object (S310) may include a step of identifying the object in the acquired image (S410). The step of identifying the object is a step of identifying the object in the image acquired through the sensor unit (40), and can identify the shape, size, and location of the object.

[0076] In one embodiment, the step of identifying an object (S410) may extract a point cloud from the acquired image. A point cloud is data that represents the shape and surface of an object in three-dimensional space as a collection of points, and can be useful for identifying the precise structure and location of an object in an image. The step of identifying an object may convert the 3D shape of the object acquired through an optical sensor or Lidar sensor into a point cloud, thereby precisely reproducing the size, shape, surface texture, etc. of the object.

[0077] In addition, the step of determining the object to be grasped (S310) may include a step of determining whether an identified object exists in the pre-stored object data (S420). The step of determining whether an identified object exists (S420) may determine whether data regarding an object identical to the object identified in the object identification step exists in the pre-stored object data. The step of determining the object to be grasped may perform grasping of the identified object if the identified object exists in the pre-stored object data.

[0078] In one embodiment, the step (S310) of determining a target object for grasping may repeatedly perform sensing if no identified object exists. The step of determining a target object for grasping may repeatedly perform sensing to continuously acquire images and compare the objects contained therein with information in pre-stored object data, but if no matching object exists, an alarm may be generated.

[0079] In one embodiment, the pre-stored object data may include a pick point corresponding to each object. Here, the pick point refers to a pre-stored gripping point of each object, and may refer to the most suitable location for the gripper to grasp the object. The pick point of an object may be determined based on the shape, center of gravity, mass, material, size, etc. of the object. For example, in the case of a square object with a center of gravity that is biased to a certain point, one of the four corners may be the pick point, and in the case of a circular object with an evenly distributed mass, the center may be the pick point. Furthermore, it is possible for a single object to have multiple pick points.

[0080] Figure 5 is a flowchart of a step for determining a phage priority according to one embodiment.

[0081] Referring to FIG. 5, a step (S430) for determining a grip priority according to one embodiment may include a step (S510) for determining a grippable pick point among each pick point of an identified object, a step (S520) for calculating a priority between grippable pick points, and a step (S530) for determining a grip priority based on the priority of the grippable pick points.

[0082] The step of determining the gripping priority (S430) may include the step of determining a grippable pick point among each pick point of the identified object (S510). The step of determining a grippable pick point may determine whether gripping is possible based on whether the gripper finger (110) collides or interferes during a gripping operation to grip the object based on the pick point of the object. For example, if the pick point of the identified object is located under another object, making it impossible to grip it, it may be determined that it is impossible to grip it.

[0083] Additionally, the step of determining the grip priority (S430) may include a step of calculating the priority between grippable pick points (S520). That is, if there are two or more determined grippable pick points, the priority may be determined between each pick point. The step of calculating the priority may determine the priority based on the degree of gripper accessibility of each pick point, the stability of the grip, the importance of the object, etc., and the priority may be determined based on various criteria, not limited to the examples described above.

[0084] In one embodiment, the priority of a pick point may be determined based on the order of the absolute height of the pick point. Here, the absolute height may refer to the height from the ground to the pick point. That is, among multiple pick points, the pick point located farthest from the ground may be determined as the first pick point.

[0085] The step of determining the grab priority (S530) can determine the grab priority based on the pick point priority. The step of determining the grab priority can determine the grab priority by first grabbing the target object of the pick point with the first priority based on the previously determined pick point priorities.

[0086]

[0087] <Determining the movement trajectory of the dark part>

[0088] Fig. 6 is a flowchart regarding a step of determining a movement trajectory of a multi-joint arm (20) according to one embodiment.

[0089] Referring to FIG. 6, a step (S320) of determining a movement trajectory of a multi-joint arm (20) according to one embodiment may include a step (S610) of determining a position of a gripping unit (10) based on a position of a gripping target object, a step (S620) of calculating possible movement trajectory candidates for moving the gripping unit (10) to the determined position of the gripping unit (10) based on the length and rotatable angle of each joint of the multi-joint arm (20), and a step (S630) of determining a final movement trajectory based on a preset criterion among the movement trajectory candidates.

[0090] The step (S320) of determining the movement trajectory of the multi-joint arm (20) may include the step (S610) of determining the position of the gripping unit (10) based on the position of the gripping target object. The step of determining the position of the gripping unit (10) is based on the position of the gripping target object to be gripped according to the gripping priority described above, and may be to set the position of the gripping unit (10) near the gripping target object so that the gripping unit (10) of the gripper can grab the gripping target object. The step of determining the position of the gripping unit (10) may determine the position of the gripping unit (10) based on the pick point position of the gripping target object, the size of the gripping target object, the length of the finger (110), the movable distance of the arm, the surrounding environment of the gripping target object, etc.

[0091] According to one embodiment, the step (S610) of determining the position of the gripping unit (10) may determine the position of the gripping unit (10) based on interference with other objects or walls around the gripping target object. In the step of determining the position of the gripping unit (10), when the gripping target object is positioned in contact with another wall and / or object, the position of the gripping unit (10) may be set as a position where the gripping unit (10) does not collide with or come into contact with the wall and / or other object during the gripping operation of the gripping target object.

[0092] The step (S320) of determining the movement trajectory of the multi-joint arm (20) may include a step (S620) of calculating possible movement trajectory candidates. The step of calculating the movement trajectory candidates may calculate movement trajectory candidates for moving the gripper (10) to the previously determined position of the gripper (10) based on the length and the rotatable angle of each joint of the multi-joint arm (20). Each joint constituting the multi-joint arm (20) of the gripper has a physical length and a range of rotatable angles, so that the multi-joint arm (20) formed by gathering a plurality of these joints may also have a maximum physical distance that it can move. If the previously determined position of the gripper (10) exists within the physical distance that the multi-joint arm (20) can move to the maximum, the multi-joint arm (20) may move through the rotation of each joint so that the gripper (10) can be positioned at the position of the corresponding gripper (10). Since various movement paths may be possible depending on the rotation range and length adjustment of each joint, the step of calculating movement trajectory candidates may calculate possible movement paths of the multi-joint arm (20) as movement trajectory candidates.

[0093] In one embodiment, the step of calculating candidate movement trajectories (S620) may determine whether a collision occurs with the gripper during movement along the movement trajectory, and may exclude a movement trajectory in which a collision exists from the candidate movement trajectories. The step of calculating candidate movement trajectories may exclude a movement trajectory from the candidates for possible movement trajectories if, while calculating possible movement trajectories, it is determined that the gripper may collide with another object and / or a wall.

[0094] The step (S320) of determining the movement trajectory of the multi-joint arm (20) may include a step (S630) of determining the final movement trajectory among the movement trajectory candidates based on preset criteria. Here, the preset criteria may include, but are not limited to, movement time, energy efficiency, ease of trajectory, etc.

[0095] In one embodiment, the step of determining the final movement trajectory (S630) may determine the final movement trajectory based on the time taken to move. That is, the step of determining the final movement trajectory may determine the movement trajectory that takes the shortest time to complete the movement of the multi-joint arm (20) among the possible movement trajectory candidates as the final movement trajectory.

[0096]

[0097] <Determining the position of the phage>

[0098] Fig. 7 is a flowchart of a step for determining a grip posture according to one embodiment.

[0099] Referring to FIG. 7, a step (S330) of determining a grip posture according to one embodiment may include a step (S710) of determining a finger (110) to be used among a plurality of fingers (110) and a step (S720) of determining the position of the finger (110) to be used.

[0100] According to one embodiment, the step (S710) of determining the finger (110) to be used may calculate the total gripping area required to grip the gripping target object. Here, the gripping area may refer to a two-dimensional plane area required to grasp the gripping target object depending on the position of the gripping unit (10) and the range of motion of the fingers (110) of the gripper. The gripping area is an area required to stably grip the object, and if a sufficient gripping area is not secured, the object cannot be stably gripped. The gripping area required for gripping may be determined by various criteria, such as the range of motion of the fingers (110) and the size of the gripping target object.

[0101] In one embodiment, the step (S710) of determining the finger (110) to be used may calculate a gripping area based on the width of the gripping target object according to the relative positions of the gripper and the gripping target object. Since the gripping target object may have various sizes and shapes, the width of the gripping target object may vary depending on the relative position of the gripping unit (10) with respect to the gripping target object, and thus the required gripping area of ​​the gripping unit (10) may vary.

[0102] In one embodiment, the step (S710) of determining the finger (110) to be used may calculate a grip area based on the size of the gripping target object. The larger the size of the gripping target object, the larger the gripping area required to grasp the object may be.

[0103] According to one embodiment, the step (S710) of determining the finger (110) to be used may calculate the gripping area based on whether there is a collision with another object. The step of determining the finger (110) to be used may determine the possibility of collision with other objects and / or walls around the gripping target object during the gripping motion. The step of determining the finger (110) to be used may simulate the possibility of collision and interference that may occur when the gripper moves to grasp the gripping target object based on the collected environmental information, and determine the possibility of collision accordingly. In addition, the step of determining the finger (110) to be used may adjust the gripping area required to minimize the possibility of collision. The smaller the gripping area, the lower the possibility of collision.

[0104] In one embodiment, the step (S710) of determining the fingers (110) to be used may select the number of fingers (110) to be used based on the grip area. The step of determining the fingers (110) to be used may determine the number of fingers (110) to be used based on various criteria based on the determined grip area.

[0105] According to one embodiment, the step (S710) of determining the fingers (110) to be used may set a reference section of the grip area and set a different number of fingers (110) required for each reference section. For example, the step of determining the fingers (110) to be used may use two fingers (110) when the grip area is 50x50 mm or less, and may use three fingers (110) when it exceeds 50x50 mm.

[0106] According to one embodiment, the step (S720) of determining the position of the finger (110) may include determining a grip surface of a gripping target object and determining the position of the finger (110) based on the grip surface. Here, the grip surface may refer to a surface of an object that the finger (110) contacts in order to stably grasp the gripping target object. This may vary depending on the shape and size of the object.

[0107] The step (S720) of determining the position of the finger (110) may determine the grip surface based on various criteria. The step of determining the position of the finger (110) may determine the grip surface by considering the structural characteristics of the object, surface friction, balance during gripping, etc. For example, among the surfaces of the object, a flat surface with high friction may be suitable as a grip surface.

[0108] The step (S720) of determining the position of the finger (110) can determine the position of the finger (110) based on the grip surface. The step of determining the position of the finger (110) can determine the arrangement of the finger (110) so that the finger (110) can make maximum contact with the grip surface to provide stable grip.

[0109] The step (S720) of determining the position of the fingers (110) may determine the arrangement of the fingers (110) based on the number of fingers (110) used. The step of determining the position of the fingers (110) may determine the arrangement of the fingers (110) by considering that each finger (110) can stably grip an object by distributing a balanced force. For example, the step of determining the position of the fingers (110) may be such that, in the case of an object having a size smaller than a preset standard, three fingers (110) are arranged in a triangular shape to maintain balance, and in the case of an object having a size larger than a preset standard, four or more fingers (110) may be arranged in a square or other suitable shape.

[0110] According to one embodiment, the step (S720) of determining the position of the finger (110) may set the direction in which the finger (110) moves toward the object to be gripped. The step of determining the position of the finger (110) may plan an approach path along which the finger (110) moves toward the object. The step of determining the position of the finger (110) may set the direction of movement by planning an optimized approach path by considering obstacle avoidance, an optimal approach angle, interference between fingers (110), etc. during this process.

[0111] Figure 8 is a schematic diagram showing the direction of movement of a finger (110) according to one embodiment.

[0112] Referring to FIG. 8, the direction in which the finger (110) moves according to one embodiment may be reverse grasping. Reverse grasping is a method of grasping an object from the inside out, and may be useful when grasping an object of a complex shape that is difficult to grasp using forward grasping or an object in a difficult-to-access location.

[0113] According to one embodiment, the step of determining the gripping posture (S330) may further include the step of determining the gripping force of each finger (110). The step of determining the gripping posture may calculate the exact force that each finger (110) must apply so that the gripping unit (10) can stably grip the object. The step of determining the gripping posture may determine the gripping force of each finger (110) based on characteristics of the object, such as size, shape, and weight, and friction with the object. The step of determining the gripping posture may determine the gripping force of each finger (110) to prevent a situation in which the finger (110) excessively presses or does not sufficiently fix the object, and to precisely adjust the force required to ensure safe gripping of the object.

[0114] According to one embodiment, the step (S330) of determining the gripping posture may further include a step of determining whether to use the suction hole (130). When the gripping part (10) further includes the suction hole (130), the step of determining the gripping posture may determine whether to use the suction hole (130). The step of determining the gripping posture may determine whether to use the suction hole (130) based on the surface characteristics, material, size, weight, and surrounding environment of the gripping target object. For example, whether to use the suction hole (130) may be determined based on whether the surface of the gripping target object is flat or round, made of glass or paper, heavy or light, and the number of surfaces that can be contacted by a finger (110).

[0115] In one embodiment, the step of determining whether to use the suction hole (130) may determine whether to use the suction hole (130) based on the grip area. For example, if the gripping target object is difficult to grip with two or three fingers (110) due to interference from surrounding objects and the environment, the contact of one finger (110) with the suction hole (130) may be used to cope with this. This may be to allow the gripping target object to escape from surrounding obstacles, and after it escapes, it may be possible to perform re-grabbing using multiple fingers (110).

[0116] According to one embodiment, the step of determining whether to use the intake hole (130) may include the step of determining the intake hole (130) to be used. The step of determining whether to use the intake hole (130) may determine the intake hole (130) to be used for gripping among the intake holes (130) present in each of the plurality of fingers (110). The step of determining whether to use the intake hole (130) may determine one or a plurality of intake holes (130) to be used for gripping. In addition, the step of determining whether to use the intake hole (130) may determine the intake hole (130) to be used so that the movement of each finger (110) can be minimized. In addition, the step of determining whether to use the intake hole (130) may determine the intake hole (130) to be used based on the pad shape of the intake hole (130).

[0117] In one embodiment, the step of determining whether to use the suction hole (130) may determine the location of the suction hole (130) on the object to be gripped. The step of determining whether to use the suction hole (130) may determine the location of the suction hole (130) based on the shear force and moment applied to the vacuum pad.

[0118] In one embodiment, the step of determining whether to use the intake hole (130) may include the step of determining the negative pressure of the intake hole (130). The step of determining whether to use the intake hole (130) may determine the negative pressure of the intake hole (130) to adjust the intake hole (130) to apply an appropriate pressure to the surface of the object, and may prevent a situation in which the object is not properly fixed or excessive pressure is applied. The step of determining whether to use the intake hole (130) may calculate the required pressure according to the suction force of the intake hole (130) and the size and material of the object, and determine the negative pressure in the intake hole (130) based on the calculated pressure.

[0119] In one embodiment, the step of determining the negative pressure of the intake hole (130) may determine the negative pressure of the intake hole (130) by the required lift force, the area of ​​the intake hole (130), and the safety factor. Here, the lift force is the force required to lift an object, the area of ​​the intake hole (130) is the area of ​​the intake hole (130) that comes into contact with the object to be gripped, and the safety factor may be a value set in advance to stably grip the object. For example, the step of determining the negative pressure of the intake hole (130) may determine the negative pressure of the intake hole (130) by the following mathematical expression 1.

[0120]

[0121] (W is the lifting force, P is the negative pressure of the intake hole (130), S is the area of ​​the intake hole (130), t is the safety factor)

[0122] In one embodiment, the step of determining the negative pressure of the suction hole (130) may determine the safety factor based on whether the gripping method is horizontal lifting or vertical lifting. Horizontal lifting refers to a gripping method in which the suction hole (130) is positioned at the top of the gripping target object to suck and lift the object, and vertical lifting refers to a gripping method in which the suction hole (130) is positioned at the side of the gripping target object to suck and lift the object. In general, since the gripping stability is lower in the case of vertical lifting than in the case of horizontal lifting, the preset safety factor may be set higher in the case of vertical lifting than in the case of horizontal lifting.

[0123] In one embodiment, the step of determining the gripping posture (S330) may further include a step of performing a positional accuracy correction operation. The step of determining the gripping posture may perform a positional accuracy correction operation to minimize positional errors by controlling the positions of each joint of the gripper and the gripping part (10) to increase the accuracy of the position at which the gripping target object is placed.

[0124] In one embodiment, the step of performing the position accuracy correction operation can correct the Z-axis and Y-axis precision of the gripping target object. The step of performing the position accuracy correction operation can correct the Z-axis and Y-axis precision of the gripping target object by calculating the relative position through the Z-axis and Y-axis information of each joint and gripping part (10) of the gripper.

[0125] According to one embodiment, the step of determining the gripping posture (S330) may determine the gripping posture based on a gripping posture preset for a gripping target object. The step of determining the gripping posture may determine the gripping posture based on a gripping posture preset by the user for each gripping target object. The preset gripping posture may refer to the number and arrangement of fingers (110) defined in advance by the user to perform optimal gripping for a specific gripping target object. The gripping method may be useful in a repetitive work environment by presetting the gripping posture.

[0126]

[0127] <Additional Steps>

[0128] In one embodiment, the gripping method may further include a step of determining whether the gripper control is performed normally. The step of determining whether the control is performed normally may determine, through various sensors, whether the gripping target object has been gripped along the planned movement trajectory and gripping posture.

[0129] In addition, the step of determining whether the gripper control is performed normally may include, if the gripper control is not performed normally, a process of releasing the gripping target object and then attempting to grip it again or re-setting the position and gripping posture of the gripping part (10).

[0130] Additionally, the step of determining whether gripper control is performed normally can generate an alarm and stop the gripping operation if an abnormal situation is detected.

[0131] By including a step for determining whether the gripper control is performed normally, the gripping method can increase the reliability and efficiency of the gripping operation and maintain stable gripping performance in various working environments.

[0132]

[0133] While the embodiments of the present invention have been described with reference to the attached drawings, those skilled in the art will appreciate that the present invention can be implemented in other specific forms without altering the technical spirit or essential characteristics thereof. Therefore, the embodiments described above should be understood to be illustrative in all respects and not restrictive.

[0134] <Explanation of symbols>

[0135] 1: Multi-joint gripper 10: Gripper 20: Multi-joint arm

[0136] 30: Control unit 40: Sensor unit 50: Drive unit

[0137] 60: negative pressure generator 110: finger 130: intake hole

[0138]

[0139] The gripping method and gripping device of the present invention can precisely and efficiently perform gripping operations suitable for objects and environments of complex and diverse shapes by controlling a multi-joint gripper, and thus have high industrial applicability.

Claims

1. A method of gripping using a multi-joint gripper including a gripping part having a multi-joint arm part and multiple fingers, which is performed by a control part, A step of analyzing an image acquired using a sensor to determine a target object to be grasped; A step of determining a movement trajectory of the multi-joint arm based on the position of the target object of the grip; A step of determining a gripping posture of a gripping part based on the gripping target object; and A step of performing gripper control based on the movement trajectory and the gripping posture; How to phage.

2. In paragraph 1, The step of determining the above-mentioned phage posture is: a step of determining which finger to use among the plurality of fingers; and a step of determining the position of the finger to be used; How to phage.

3. In paragraph 2, The step of deciding which finger to use is: Characterized in that it calculates the total gripping area required to grip the above gripping target object. How to phage.

4. In paragraph 3, The step of deciding which finger to use is: Characterized in that the total gripping area is calculated based on at least one selected from the width of the gripping target object, the size of the gripping target object, and whether there is a collision with another object according to the relative position of the gripping target object and the gripper. How to phage.

5. In paragraph 2, The step of determining the position of the above fingers is: It is characterized in that the grip surface of the grip target object that the finger can contact is determined, and the position of the finger is determined based on the grip surface. How to phage.

6. In paragraph 5, The step of determining the position of the above fingers is: Based on the grip surface, the direction in which the finger moves toward the grip target object is set. How to phage.

7. In paragraph 6, The above moving direction is, Featuring reverse gripping How to phage.

8. In paragraph 2, The steps to determine the position of the phage are: A step of determining the gripping force of each finger; further comprising: How to phage.

9. In paragraph 2, The above-mentioned part, It further includes an intake hole capable of absorbing the above target object through negative pressure, The step of determining the above-mentioned phage posture is: A step of determining whether to use the above intake hole; further comprising: How to phage.

10. In paragraph 2, The step of determining the above-mentioned phage posture is: A step of performing a position precision correction operation for correcting the Z-axis and Y-axis direction precision of the above-mentioned target object; further comprising; How to phage.

11. In paragraph 1, The step of determining the above-mentioned phage posture is: It is characterized in that the gripping posture is determined based on a preset gripping posture corresponding to the gripping target object. How to phage.

12. In paragraph 1, The step of determining the movement trajectory of the above multi-joint arm part is: A step of determining the position of the gripping part based on the position of the gripping target object; A step of calculating possible movement trajectory candidates for moving the gripping part to the position of the gripping part based on the length and rotatable angle of each joint of the multi-joint arm part; and A step of determining a final movement trajectory among the above movement trajectory candidates based on preset criteria; including; How to phage.

13. In paragraph 12, The step of determining the position of the above-mentioned part is: It is characterized in that the position of the gripping part is determined based on interference with other objects or walls around the gripping target object. How to phage.

14. In paragraph 13, The step of calculating the above movement trajectory candidates is: It is characterized in that it determines whether a collision occurs in the gripper while moving along the movement trajectory, and the movement trajectory in which the collision exists is excluded from the movement trajectory candidates. How to phage.

15. In paragraph 12, The step of determining the final movement trajectory is: Characterized in that the final movement trajectory is determined based on the time taken to move. How to phage.

16. In paragraph 1, The step of determining the above target object is: A step of identifying an object in the acquired image; A step of determining whether the identified object exists in the pre-stored object data; and a step of determining a phage priority among the identified objects; How to phage.

17. In paragraph 16, The above pre-saved object data is, Contains pick points corresponding to each object, The step of determining the above phage priority is: A step of determining a pick point that can be gripped among each pick point of the identified object; A step of calculating priorities among the above-mentioned pick points; and A step of determining the grip priority based on the priority of the grippable pick points; How to phage.

18. In paragraph 17, The step of calculating the priority of the above pick points is: Characterized in that it is determined based on the height order of the absolute position of the above pick point. How to phage.

19. In paragraph 1, A step of determining whether gripper control is performed normally; further comprising How to phage.

20. A gripping device using a multi-joint gripper including a multi-joint arm and a gripping part having multiple fingers, A control unit that controls the operation of the multi-joint arm and grip unit; The above control unit, Analyze the image acquired using the sensor to determine the target object to be grasped, Determine the movement trajectory of the multi-joint arm based on the position of the target object to be grasped, Determine the gripping posture of the gripping part based on the gripping target object, Perform gripper control based on the above movement trajectory and the above gripping posture. Phage device.

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