Hand for robot, picking robot and picking device

Abstract

To provide a hand for a robot that is configured to deform following a shape of an object to be picked to pick various objects, which is suppressed from becoming too heavy in weight.SOLUTION: A hand for a robot is provided with: a bag body with flexibility that has a hollow part therein and can deform following a shape of an object to be picked; at least one adsorption pad installed at the position where the bag body contacts the object to be picked; an intake pipe, connected continuously to the adsorption pad, which sucks in air from the adsorption pad; MR fluid that is enclosed into the hollow part of the bad body; and an electromagnet for applying a magnetic field to the MR fluid.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a robot hand, a picking robot, and a picking device that are capable of picking various objects by deforming to conform to the object to be picked, while not being too heavy. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there exists a type of hand portion of a picking robot that uses MR fluid (Magneto Rheological Fluid, also called magnetic fluid).

[0003] A hand using MR fluid has already been proposed, for example, in Patent Document 1. Patent Document 1 discloses a gripping mechanism that grips a small object by applying a magnetic field to the MR fluid in a state where the small object is wrapped in a bag containing the MR fluid, thereby increasing the shear stress of the MR fluid. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-162981 A Summary of the Invention [Problem to be solved by the invention]

[0005] According to the gripping mechanism described in Patent Document 1, an object smaller than the obi is wrapped in the obi, and can be gripped by increasing the shear stress of the MR fluid when electricity is applied, but an object larger than the obi cannot be wrapped and gripped. If the bag is made large enough to wrap an object with a large shape, the weight of the hand part becomes large and there is a high possibility that the robot's carrying capacity will be exceeded, so making the bag large is problematic in terms of the load on the robot. Therefore, there has been a demand for a mechanism for the hand part that can pick various objects by deforming to imitate the object to be picked, while not becoming too heavy.

[0006] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a robot hand, a picking robot, and a picking device that can pick various objects by deforming to imitate the object to be picked, while not being too heavy. [Means for solving the problem]

[0007] The robot hand of the present invention is a robot hand for use in connection with a picking robot for picking an object to be picked, and is characterized in that it comprises a bag body having a hollow space therein and flexible enough to deform to conform to the object to be picked, at least one suction pad installed at a location on the bag body that contacts the object to be picked, an air intake pipe connected continuously to the suction pads for sucking air from the suction pads, an MR fluid sealed in the hollow space of the bag body, and an electromagnet for applying a magnetic field to the MR fluid.

[0008] Furthermore, in the robot hand of the present invention, the bag body is further characterized in that it is roughly cylindrical in shape, has the suction pad on the surface that corresponds to the bottom surface of the cylinder, and the cylindrical bottom surface equipped with the suction pad is capable of deforming to conform to the object to be picked.

[0009] A picking robot according to the present invention is characterized by including any one of the robot hands described above.

[0010] The picking device according to the present invention is a picking device including a picking robot having a hand unit for picking an object to be picked, a position specifying means for specifying the position of the object to be picked, and a control unit for controlling the picking operation of the picking robot, the hand unit including a bag body having a hollow portion therein and having flexibility so as to be deformable in accordance with the object to be picked, at least one suction pad installed at a position of the bag body that contacts the object to be picked, an intake pipe connected continuously to the suction pad and for sucking air from the suction pad, and the bag body having a hollow portion and a flexible portion that can be deformed in accordance with the object to be picked. The picking device is equipped with an MR fluid sealed in a hollow space and an electromagnet for applying a magnetic field to the MR fluid, and the control unit has the functions of executing a position identification procedure for identifying the position of the object to be picked based on the position identification means, a pressing procedure for pressing the installation surface of the suction pad of the hand unit against the identified object to be picked, a hardening procedure for applying a magnetic field to the MR fluid using the electromagnet to harden it, an adsorption procedure for sucking air from the suction pad to adsorb the object to be picked, and a movement procedure for moving the object to be picked to a desired position. Effect of the Invention

[0011] According to the present invention, before a magnetic field is applied to the MR fluid, the bag body flexibly deforms to conform to the object to be picked, thereby allowing the MR fluid to be in close contact with various objects. When a magnetic field is applied to the MR fluid in this state, the MR fluid hardens with the bag body in close contact with the object to be picked, maintaining the close contact state. By performing suction in this state, it becomes possible to generate a strong suction force. This makes it possible to pick the object to be picked without wrapping it in the bag body. As a result, it becomes possible to provide a robot hand that is not too heavy while being able to pick various objects by deforming to conform to the object to be picked. [Brief description of the drawings]

[0012] [Figure 1] 1 is an explanatory diagram for explaining an overall configuration of a picking device according to an embodiment of the present invention; [Diagram 2] 1 is a perspective view showing an example of the configuration of a hand unit of a picking robot according to an embodiment of the present invention; [Diagram 3] 1 is a perspective view showing a state in which a picking target is picked up by a hand portion of a picking robot corresponding to an embodiment of the present invention. FIG. [Figure 4] 10 is a flowchart showing a flow of a picking process executed in a control unit of a picking device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an example of a picking device according to an embodiment of the present invention will be described with reference to the drawings.

[0014] Fig. 1 is an explanatory diagram for explaining the overall configuration of a picking device corresponding to an embodiment of the present invention. As shown in Fig. 1, the picking device 100 includes a control unit 40 that controls each component, a picking robot 10, a hand unit (including cases where it is expressed as a robot hand) 20, a position specifying means 30, and the control unit 40. In addition, in this example, a situation is assumed in which a picking target 50 is picked by the picking robot 10.

[0015] The picking robot 10 is a robot equipped with a hand unit 20 that picks up a picking target 50. In this example, the picking robot 10 is described as equipped with a hand unit 20 that sucks up and holds the picking target 50 by suction while deforming to follow the shape of the picking target 50. The operation of this picking robot 10 is controlled by a control unit 40, which will be described later.

[0016] The position specifying means 30 is a configuration for specifying the position of the picking target 50. The position specifying means 30 may be any means capable of specifying the position of the picking target 50. When the purpose is to specify the position of the picking target 50 in a two-dimensional plane (the position in the plane on which the picking target 50 is placed), the position specifying means 30 may be, for example, a two-dimensional camera. Various proposals can be adopted for the installation location of the two-dimensional camera, and for example, it is possible to install the camera near the hand unit 20 of the picking robot 10. As long as the picking target can be photographed, various shooting angles can be set, but when the purpose is to specify the position in a two-dimensional plane, it is preferable to install the camera so that the picking target 50 is photographed from above. The execution of photography of this two-dimensional camera is controlled by a control unit 40 described later.

[0017] In addition, when the purpose of the position specifying means 30 is to specify the position including the distance information to each point of the picking target 50 (three-dimensional coordinate information of each point of the picking target 50), the position specifying means 30 may acquire distance information using, for example, a stereo camera. In addition, the position specifying means 30 may be configured to acquire distance information using a TOF camera (Time-of-Flight Camera) or LiDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging). The distance information is acquired as three-dimensional point cloud information. The acquisition of the distance information in this position specifying means 30 is controlled by a control unit 40 described later. The device for acquiring this distance information can be set to various shooting angles as long as it can capture the picking target 50, but it is preferable to install it so that the picking target 50 is captured from above. In addition, when a stereo camera is adopted as the position specifying means 30, it is possible to treat one piece of image data captured by the stereo camera as image data captured by a two-dimensional camera, and acquire distance information using two pieces of image data captured by the stereo camera.

[0018] The control unit 40 is configured to control the position identification of the picking target 50 by the position identification means 30 and the picking operation by the picking robot 10. The control unit 40 may be configured by any means capable of executing the control described below, and may be realized by, for example, a computer, a microcomputer, a PLC (Programmable Logic Controller), or a combination of these. Among these, the computer may be configured to have a CPU (Central Processing Unit), which would normally be provided in a general computer, a memory, and a storage such as a hard disk drive or SSD, and also to have an input device such as a mouse or keyboard, an output device such as a display or a printer, and a communication device for connecting to a communication network, and these may be connected via a bus. The processing in each part of the control unit 40 is realized by reading a program for executing the processing in each part from the memory and executing it in a CPU, GPU, or FPGA (Field Programmable Gate Array) that functions as a control circuit (processing circuitry). In other words, the processor (processing circuit) is configured to be able to execute each processing of each device by executing the program. Also, a configuration is conceivable in which the processing up to obtaining the information on the recommended picking position of the picking target object 50 is executed by a computer, and the operation control of the picking robot 10 using the information on the recommended picking position is realized by a PLC. Also, it goes without saying that various data used by the control unit 40 and various data obtained as a result of the processing by the control unit 40 are appropriately stored in a storage unit.

[0019] In addition, in Figure 1, the control unit 40 is shown to be provided outside the picking robot 10, but this is not limited to this, and the picking robot 10 may be configured to have a control unit equivalent to the control unit 40 inside the picking robot 10.

[0020] FIG. 2 is a perspective view showing an example of the configuration of a hand unit of a picking robot corresponding to an embodiment of the present invention. As shown in FIG. 2, the hand unit 20 attached to the picking robot 10 in this example includes a bag body 21. The bag body 21 has a hollow portion inside and is flexible enough to be deformed to conform to the picking target 50. As long as the bag body 21 can be deformed to conform to the picking target 50, various materials can be used for the bag body 21, and examples of such materials include silicone rubber, resin sheets, and rubber sheets. At least one suction pad 22 is installed on the tip surface of the bag body 21. In the example of FIG. 2, four suction pads 22 are installed. In addition, an intake pipe 23 for sucking air is connected to each of the suction pads 22. The opposite end of the intake pipe 23 is connected to an air compressor (not shown), and the air compressor sucks air, making it possible to suck and lift the picking target 50 with the suction pad 22.

[0021] In addition, MR fluid is enclosed in the hollow parts inside the bag body 21 except for the part through which the intake pipe 23 passes. The gap between the bag body 21 and the part through which the intake pipe 23 passes is also completely sealed so that the MR fluid does not leak. The MR fluid may be of any type as long as it can achieve a predetermined hardness that allows it to retain a shape following the shape of the picking target 50 when a magnetic field is applied, and it is not required to have a specific composition. The hand unit 20 is provided with an electromagnet (not shown) for applying a magnetic field to the MR fluid.

[0022] The bag body 21 may have various shapes as long as it can deform to conform to the object to be picked. For example, it may be roughly cylindrical in shape, with an suction pad 22 provided on the surface that corresponds to the bottom of the cylinder, and the cylindrical bottom surface provided with the suction pad 22 may be deformed to conform to the object 50 to be picked.

[0023] 2 shows a state before the installation surface of the suction pad 22 of the hand unit 20 is pressed against the picking target 50. In this state, since no magnetic field is applied to the MR fluid inside the bag body 21, the MR fluid acts as a fluid, and the bag body 21 can flexibly deform.

[0024] FIG. 3 is a perspective view showing a state where a picking target is picked by a hand unit of a picking robot corresponding to an embodiment of the present invention. This FIG. 3 shows a state after the installation surface of the suction pad 22 of the hand unit 20 is pressed against the picking target 50. When the installation surface of the suction pad 22 of the hand unit is pressed against the picking target 50, the bag body 21 flexibly deforms following the shape of the picking target 50, forming a state in which the bag body 21 is in close contact with the surface of the picking target 50. When a magnetic field is applied to the MR fluid inside the bag body 21 in a state in which the bag body 21 is in close contact with the surface of the picking target 50, the MR fluid hardens in a state in which the bag body 21 is in close contact with the surface of the picking target 50, so that the bag body 21 maintains its shape at the time of close contact while the electromagnet is continuously energized. When suction is started by the air compressor in this state, suction is started in a state in which the bag body 21 is in close contact with the surface of the picking target 50, so a strong suction force is generated. This makes it possible to strongly suction the picking target 50 and pick it.

[0025] FIG. 4 is a flowchart showing the flow of a picking process executed by a control unit in a picking device corresponding to an embodiment of the present invention. As shown in FIG. 4, the picking process is started by the control unit 40 identifying the position of the picking target 50 (step S101). Next, the control unit 40 controls the picking robot 10 to press the installation surface of the suction pad 22 of the hand unit 20 against the picking target 50 (step S102). Next, the control unit 40 applies a magnetic field to the MR fluid inside the bag body 21 to harden the MR fluid (step S103). Next, the control unit 40 uses an air compressor to suck from the suction pad 22 to adsorb the picking target 50 (step S104). Then, the control unit 40 controls the picking target 50 to move while the picking target 50 is being adsorbed (step S105), and ends the picking process. Note that this flowchart is merely an example of control, and is not limited to the process of FIG. 4.

[0026] As described above, the robot hand according to the present invention includes a bag body having a hollow portion therein and flexibility capable of deforming in accordance with the picking target, at least one suction pad installed at a portion of the bag body that contacts the picking target, an air intake pipe connected continuously to the suction pad for sucking air from the suction pad, an MR fluid sealed in the hollow portion of the bag body, and an electromagnet for applying a magnetic field to the MR fluid. Therefore, before the magnetic field is applied to the MR fluid, the bag body can flexibly deform in accordance with the picking target to create a state in which it is in close contact with various objects, and when a magnetic field is applied to the MR fluid in this state, the MR fluid hardens in a state in which the bag body is in close contact with the picking target, and the close contact state is maintained. By performing suction in this state, it is possible to generate a strong suction force. This makes it possible to pick the picking target without wrapping it in the bag body. As a result, it is possible to provide a robot hand that can pick various objects by deforming in accordance with the picking target, while not becoming too heavy. [Explanation of symbols]

[0027] 100 Picking device 10. Picking Robot 20 Hand section 30 Location identification means 40 Control Unit 50 Picking objects

Claims

1. A robot hand for use in connection with a picking robot for picking up a picking target, A bag body having a hollow portion therein and flexibility capable of being deformed to conform to the picking target; At least one suction pad is provided at a portion of the bag body that contacts the picking target; an intake pipe connected continuously to the suction pad for sucking air from the suction pad; an MR fluid enclosed within the hollow portion of the bag; an electromagnet for applying a magnetic field to the MR fluid; A robot hand comprising:

2. The bag body is generally cylindrical in shape, and the suction pad is provided on the surface that corresponds to the bottom surface of the cylinder, and the cylindrical bottom surface provided with the suction pad can be deformed to conform to the picking target. The robot hand according to claim 1.

3. A picking robot comprising the robot hand according to claim 1 or 2.

4. A picking device including a picking robot having a hand unit for picking up a picking target, a position specifying means for specifying a position of the picking target, and a control unit for controlling a picking operation of the picking robot, The hand unit includes: A bag body having a hollow portion therein and flexibility capable of being deformed to conform to the picking target; At least one suction pad is provided at a portion of the bag body that contacts the picking target; an intake pipe connected continuously to the suction pad for sucking air from the suction pad; an MR fluid enclosed within the hollow portion of the bag; an electromagnet for applying a magnetic field to the MR fluid; Equipped with The control unit a position identification step of identifying a position of the picking target based on the position identification means; a pressing step of pressing an installation surface of the suction pad of the hand unit against the identified picking target; a hardening step of hardening the MR fluid by applying a magnetic field to the MR fluid by the electromagnet; a suction step of sucking air from a suction pad to suck the picking target; a moving procedure for moving the picking target to a target position; Equipped with the function to execute A picking device comprising:

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