WO2019021520A1

WO2019021520A1 - End effector, and object grasping system in which end effector is used

Info

Publication number: WO2019021520A1
Application number: PCT/JP2018/008834
Authority: WO
Inventors: 裕池田; 北野　誠; 有坂　寿洋; 青野　宇紀; 金丸　昌敏; 小田井　正樹
Original assignee: 株式会社日立製作所
Priority date: 2017-07-26
Filing date: 2018-03-07
Publication date: 2019-01-31
Also published as: JP2019025551A

Abstract

An end effector for grasping an object to be grasped, wherein it is possible to stably grasp the object to be grasped without making the structure of the end effector more complicated, and to grasp in a manner adapted to the object to be grasped irrespective of the shape of the object to be grasped. For this purpose, provided is an end effector for grasping an object to be grasped, said end effector comprising a force input connection member 101, a grasping member 102, a force transmission connection member 106, and a restriction connection member 107, wherein a rotation control device 210 is provided to at least one or more rotation shafts that respectively connect a support member 1, the force input connection member 101, the grasping member 102, the force transmission connection member 106, and the restriction connection member 107.

Description

End effector and object gripping system using end effector

The present invention relates to an end effector and an object gripping system using the end effector.

With the declining birth rate and the aging population, the working age population is decreasing. This decline in the working-age population is a cause of labor shortages, heavy labor, and reduced productivity in the manufacturing industry. Furthermore, the decline in the working-age population is a factor that causes labor shortages, labor in harsh environments, and deterioration of service quality in the medical services and welfare, life support, disaster prevention, and maintenance and other service fields. The use of robots is expected as one of the means to solve such social problems. A robot is a mechanical system having three elemental technologies: sensor technology, actuator technology, and control technology. In order for the robot to solve the social problem, it is essential that it be able to substitute the human-made (complex, precise, flexible) work. In particular, an end effector that is a contact point between a work object and a person is important.

As an example of the end effector, there is a hand mechanism described in Patent Document 1. The hand mechanism described in Patent Document 1 includes two articulated fingers and one single articulated finger for gripping an object, and applies a biasing force in a direction to close the hand mechanism on the single articulated finger side. By adopting, it has simplification of structure of a hand mechanism, and a comparatively high grasping function.

As another example of the end effector, there is a multi-fingered robot hand described in Patent Document 2. The multi-fingered robot hand described in Patent Document 2 includes a first palm portion in which three finger mechanisms are coupled via a root joint, and a second palm portion in which one finger mechanism is coupled via a root joint. And a palm joint connecting the first palm and the second palm, wherein the palm joint is configured to allow a change in the connection angle of the second palm to the first palm. By configuring as described above, various articles can be stably gripped while suppressing an increase in the number of joints of the finger mechanism.

JP, 2015-112651, A JP 2008-149448 A

The hand mechanism disclosed in Patent Document 1 includes a multi-fingered finger and a single-articulated finger, and applies a biasing force in a direction to close the hand mechanism on the single-articulated finger side. It is said that it can be gripped by force from both of the two and single articulated fingers. The articulated finger is configured by combining a plurality of four-bar linkages. Joints connecting respective joints (links) rotatably support between the links. The articulated finger grips the object to be grasped in the second mode in such a manner that the finger part rolls in the object to be grasped. In order for the finger to grip the object to be gripped in such a manner that the object to be gripped is gripped, the first finger abuts on the object to be gripped, and the first finger rotates around the rotation center on the root side of the first finger. It is necessary for the gripping object to apply a force to the first finger that is sufficient to prevent this. In order to effectively apply a force to the first finger, the object to be grasped must be limited, for example, as a certain weight or more, or the object to be grasped must be fixed. Furthermore, when the surface of the object to be grasped is flexible or when the bending rigidity of the object to be grasped is small, there is a possibility that the finger portion can not be grasped in a form of rolling in.

In the multi-fingered robot hand of Patent Document 2, a motor is incorporated in a bone member or a palm portion to drive a joint portion. A gear drive system, a wire drive system, a belt drive system, and a link drive system can be used as a method of transmitting the driving force of the motor to the joint. The multi-fingered robot hand is trying to realize an operation of reliably grasping the object to be grasped by controlling each finger by finely driving each joint. However, the frequent use of the motor may lead to an undesirable situation such as a complicated structure and a deterioration in maintainability. Furthermore, in order to incorporate a motor into a bone member or the like, the output of the motor must be increased depending on the gripping force to be generated. Generally, when the output of the motor is increased, the size of the motor is also increased, so that the size of the multi-fingered robot hand itself is increased, and hence the weight is increased. When the weight of the multi-fingered robot hand is increased, there is a possibility that it may be necessary to increase the portability of the arm on which the multi-fingered robot hand is mounted in order to realize the assumed gripping weight.

In view of the above problems, the present invention has, for example, the following features.

An end effector for gripping an object to be grasped, comprising: a force input coupling member, a grasping member, a force transmission coupling member, and a restraining coupling member, a support member, a force input coupling member, and a grasping member A rotation control device is provided on at least one or more of rotation shafts connecting the force transmission connecting member and the restraining connecting member.

In an end effector for gripping a gripping object, the gripping object can be stably gripped without complicating the structure of the end effector, and regardless of the nature of the gripping object, the gripping object It can be gripped to follow. Problems, configurations, and effects other than those described above will be apparent from the description of the embodiments below.

Example of articulated finger Sectional view of articulated finger 100 Perspective view of articulated finger 100 An example of an end effector An example of the operation of the end effector 200 An example of the operation of the end effector 200 An example of the operation of the end effector 200 Example of rotation control device Example of rotation control device Example of rotation control device Example of rotation control device Example of rotation control device Example of rotation control device Example of rotation control device Example of rotation control device Example of rotation control device Example of rotation control device Example of rotation control device Example of rotation control device Example of rotation control device An explanatory view showing an object gripping system 500 using the end effector 530 Flow chart for explaining the operation of holding the object to be held by the object holding system 500

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following description shows specific examples of the content of the present invention, and the present invention is not limited to these descriptions, and various modifications by those skilled in the art can be made within the scope of the technical idea disclosed herein. Changes and modifications are possible.

FIG. 1 shows an example of an embodiment of the present invention.

FIG. 1 shows an example of an articulated finger. The articulated finger unit 100 is rotatably coupled to the force input coupling member 101 rotatably supported by a fixed portion (indicated by symbol G) (not shown) and the force input coupling member 101. The first force transmission connection member 106 is rotatably coupled to the first force transmission connection member 106 that transmits the force input to the first force transmission connection member 106, and is input to the force input connection member 101. And a second force transmission coupling member 108 rotatably coupled to the second force transmission coupling member 108 and input to the force input coupling member 101, and the first force transmission coupling member 106 And a third force transmission coupling member 110 for transmitting a force via the second force transmission coupling member 108. Furthermore, in the articulated finger unit 100, the first grip member 102 rotatably supported coaxially with the rotation shaft supported by the fixed portion (not shown) of the force input coupling member 101, the first grip member 102, and the rotation. The second gripping member 103 connected in a possible manner, the third gripping member 104 rotatably connected to the second gripping member 103, the third gripping member 104 and the third force transmission connecting member 110 , And a fourth gripping member 105 rotatably connected to the. Furthermore, the articulated finger unit 100 has a rotation shaft to which the first force transmission connection member 106 and the second force transmission connection member 108 are rotatably connected, the first holding member 102, and the second holding member. A first restraint coupling member 107 rotatably coupling the member 103 and a rotational shaft to which the member 103 is rotatably coupled; a second force transmission coupling member 108 and a third force transmission coupling member 110; Includes a second restraint coupling member 109 rotatably coupling a rotation shaft rotatably coupled and a rotation shaft disposed in the second gripping member 103.

The first gripping member 102, the second gripping member 103, the third gripping member 104, and the fourth gripping member 105 have surfaces facing each other in the direction described as the left in the figure, The first cushioning member 112, the second cushioning member 113, the third cushioning member 114, and the fourth cushioning member 115 are disposed on the opposite surfaces, respectively. Each buffer member may be, for example, a polymer material such as resin, rubber, or gel, or may be a structure having a spring element.

The force input connecting member 101 rotatably supported by the fixed portion (not shown) includes a rotation shaft rotatably supported by the fixed portion and a rotation shaft rotatably connecting the first force transmission connecting member 106. The rotary shaft receives a force from a power unit (not shown), and the rotary shaft receives a force in the arrow direction generally indicated by F. The force from the power unit acting in the direction of the arrow generally indicated by F may be, for example, an electric linear motor or an electric rotary motor having a mechanism for converting the rotation into a linear direction. A cylinder using air pressure may be used, or a cylinder using fluid (for example, water, oil, etc.) pressure may be used. The force applied from the power unit is transmitted by the force transmission coupling member, and further transmitted to the gripping member through the restraining coupling member, and rotated about the rotation axis connecting the members to change the coupling angle between the gripping members It is configured to be able to

FIG. 2 shows a cross-sectional view of the articulated finger unit 100 shown in FIG. The first constraining connection member 107 includes a first rotation shaft 123 and a second rotation shaft 124 as rotatable shafts. In addition, the second restraint coupling member 109 includes a third rotation shaft 125 and a fourth rotation shaft 126 as rotatable shafts. The first constraining connection member 107 causes the rotation shaft 124 to move on a locus having the rotation shaft 123 and the rotation 124 as a radius around the rotation shaft 123. In addition, the rotation shaft 126 moves on a locus whose rotation axis 125 and rotation 126 are the radius around the rotation axis 125 by the second restraint connecting member 109.

The perspective view of the articulated finger part 100 is shown in FIG. 3, and the rotation axis of the articulated finger part 100 is demonstrated. The rotating shaft 120 coaxially connects a fixed portion (not shown), the force input connecting member 101, and the first gripping member 102.
The rotation shaft 121 coaxially couples the force input coupling member 101 and the first force transmission coupling member 106.

The rotating shaft 122 is connected to a power unit (not shown).

The rotation shaft 123 coaxially connects the first holding member 102, the second holding member 103, and the first restraint connecting member 107.

The rotation shaft 124 coaxially connects the first force transmission connection member 106, the second force transmission connection member 108, and the first restraint connection member 107.

The rotation shaft 125 coaxially connects the second gripping member 103 and the second restraint connecting member 109.

The rotation shaft 126 coaxially connects the second force transmission connection member 108, the third force transmission connection member 110, and the second restraint connection member 109.

The rotation shaft 127 coaxially connects the second gripping member 103 and the third gripping member 104.

The rotating shaft 128 coaxially connects the third gripping member 104 and the fourth gripping member 105.

The rotating shaft 129 coaxially connects the third force transmission connecting member 110 and the fourth gripping member 105.

The rotating shaft 120 is supported by a fixed portion (indicated by a symbol G) not shown. When a force is input in a direction orthogonal to the rotation shaft 122, the force input connecting member 101 rotates around the rotation shaft 120. When the force input coupling member 101 rotates around the rotation shaft 120, the first force transmission coupling member 106 connected to the rotation shaft 121 can be moved.

By constraining the rotation between each rotation axis and the member, the form of the articulated finger 100 can be changed. Moreover, each member connected by each rotating shaft is made into a U-shape, and it is set as the structure which makes the opening part of each member cross over a rotating shaft. Therefore, the articulated finger portion is configured in a substantially rectangular shape, and has an effect of increasing the strength.

FIG. 4 shows an example of the end effector. The end effector 200 includes a first support member 1, a second support member 2, a fixed gripping member 3, a force input connecting member 6, and a rotating shaft 7 and a rotating shaft 8 disposed on the force input connecting member 6. , The rotation shaft 9, the rotation shaft 9 and the first force transmission connection member 12 coaxial with one end of the rotation shaft 9, and the first force transmission connection member 12 disposed at the other end different from the rotation shaft 9 A rotary shaft 13, a second force transmission coupling member 18 having the rotary shaft 13 at one end, and a rotary shaft 19 disposed at the other end of the second force transmission coupling member 18 different from the rotary shaft 13; In addition to the rotation shaft 24 disposed at the other end of the third force transmission connection member 23 whose end is the rotation shaft 19 and the other end of the third force transmission connection member 23 different from the rotation shaft 19, and the rotation shaft 24. And a fourth grip member 25 on which the rotation shaft 22 is disposed. Furthermore, the end effector 200 includes a first gripping member 10 having the rotating shaft 7 at one end, a rotating shaft 11 located at the other end of the first gripping member 10 different from the rotating shaft 7, and a rotating shaft 11 A second holding member 15 having one end, a rotation shaft 16 disposed at the other end of the second holding member 15 different from the rotation shaft 11, and a rotation shaft disposed at the second holding member 15 11 and the rotary shaft 16, the first constraining connection member 14 connecting the rotary shaft 13 and the rotary shaft 19 respectively, the second constraining connection member 20, and the second gripping member 15 the rotary shaft 11 and the rotary shaft A third holding member 21 having a rotation shaft 17 disposed apart from a plane including the first and the second rotation members 16 and a rotation shaft 22 disposed at the other end of the rotation shaft 17 at the other end and the fourth holding member 25 at the other end. And an articulated finger portion. Furthermore, a third support member 5 sharing the rotary shaft 7 disposed in the force input coupling member 6 and a fourth support member connected to the third support member 5 and fixed to the second support member 2 4 and having an articulated finger portion. Although one articulated finger part is arrange | positioned in FIG. 4, several articulated finger parts may be arranged in parallel. The rotation shaft 7, the rotation shaft 11, the rotation shaft 17, the rotation shaft 13, and the rotation shaft 19 are provided with a rotation control device described later, and in the rotation control device, the members that share the rotation shaft and the members are the rotation shafts Control is performed by commands from the host device so as to be fixed or rotate around.

FIG. 5 is a view for explaining an example of the operation of the end effector 200. When a force is applied to the rotating shaft 8 of the force input connecting member 6, the force input connecting member 6 rotates counterclockwise around the rotating shaft 7. At this time, the rotation control device described later (not shown) suppresses the rotation of the first holding member 10 about the rotation axis 7 and further suppresses the rotation of the second holding member 15 about the rotation axis 11; Furthermore, the rotation of the third gripping member 21 about the rotation axis 17 is suppressed. When the force input coupling member 6 rotates around the rotation shaft 7, the first force transmission coupling member 12 connected to the rotation shaft 9 moves. When the first force transmission connection member further moves, the second force transmission connection member 18 and the first restraint connection member 14 connected by the rotation shaft 13 also move. When the second force transmission connection member 18 moves, the third force transmission connection member 23 connected by the rotation shaft 19 moves. When the third force transmission coupling member 23 moves, the rotation shaft 24 is rotated around the rotation shaft 22. In this manner, a force is applied to the rotation shaft 8 of the force input connecting member 6 to rotate the force input connecting member 6 and a predetermined operation of the rotation control device (not shown) is performed, thereby the fourth holding member 25 can be rotated about the rotation axis 22.

FIG. 6 is a diagram for explaining an example of the operation of the end effector 200. An example of gripping the gripping target 50 is shown. As shown in FIG. 5, when a force is applied to the rotation shaft 8 of the force input connecting member 6, the force input connecting member 6 rotates counterclockwise around the rotation shaft 7. At this time, the rotation control device described later (not shown) suppresses the rotation of the first holding member 10 around the rotation shaft 7, and further the second force transmission connecting member 18 around the rotation shaft 13 and the first The rotation of the restraint coupling member 14 is restrained, and furthermore, the rotation of the third force transmission coupling member 23 and the second restraint coupling member 20 about the rotation axis 19 is restrained. When the force input coupling member 6 rotates, the first force transmission coupling member 12 moves. Furthermore, when the first force transmission connection member 12 moves, the rotationally constrained second force transmission connection member 18 and the first restraint connection member 14 rotate around the rotation shaft 11. Furthermore, with the rotation of the second force transmission connecting member 18, the opposing second gripping member 15 rotates around the rotation shaft 11, contacts the gripping target 50, and stops. When the second force transmission connection member 18 further moves, the rotationally constrained third force transmission connection member 23 and the second restraint connection member 20 rotate around the rotation axis 16. The third gripping member 21 which is opposite to the third force transmission connecting member 23 rotates around the rotation shaft 17 and comes into contact with the gripping object 50 to stop. When the third force transmission connecting member 23 further moves, the third force transmission connecting member 23 rotates around the rotation axis 22 and contacts the gripping target 50 to stop. Thus, the end effector 200 grips the gripping target 50. Holding the object to be grasped 50 by arranging the sensors (not shown) for detecting force on the first to fourth buffer members attached to the first to fourth grasping members described in FIG. 1 It is also possible to control the force of Further, by detecting a force (sliding force) in a direction orthogonal to the direction of the gripping force acting on the gripping object 50, it can be determined whether the gripping object 50 is stably (stationarily) gripped. It is possible. If it is determined that the object is not grasped, it is possible to input a force to the force input connecting member 6 from a power unit (not shown) to increase the grasping force and stably grasp the grasped object 50 It is.

FIG. 7 is a view for explaining an example of the operation of the end effector 200. An example of gripping the gripping target 51 is shown. Description will be made except for the parts overlapping with FIG. At a timing when the force input coupling member 6 starts to rotate around the rotation shaft 7, the first gripping member 10 is caused to rotate around the rotation shaft 7 by a rotation control device (not shown) described later (not shown). When the gripping member 10 reaches a predetermined rotation angle, rotation control knowledge prevents the first gripping member 10 from rotating around the rotation axis 7. By operating each part as described above and in FIG. 6, it is possible to grip the object to be grasped 51.

8 to 14 show an example of an embodiment for realizing the rotation control device. The end effector of the present invention includes a rotation control device on a rotation shaft that connects the force transmission connection member, the gripping member, and the restraint connection member, and regulates the rotation angle of each member around the rotation shaft at an arbitrary timing. It is possible. Further, by arranging the rotation control device, it is possible to bend the articulated finger without contacting the object to be grasped, to grasp the object to be grasped, and to simplify the structure of the end effector. A combination of the rotation control devices described in FIGS. 8 to 14 may be used as a new rotation control device.

8A and 8B are explanatory diagrams showing an example of the rotation control device. The rotation control device 210 shown in FIG. 8A is not shown with a force input coupling member, a force transmitting coupling member or a magnet 213 disposed on the gripping member 214, and a movable iron core 212 having a surface that contacts the magnet 213 in a relative manner. It is comprised from the coil 211 which consists of a bobbin and a lead wire, and a copper wire. As shown in FIG. 8A, the magnet 213 and the movable iron core 212 disposed on the force input coupling member, the force transmission coupling member or the holding member 214 generate an attracting force in the vertical direction on the surface where both are in contact by the magnetic force of the magnet 213 . Therefore, assuming that the maximum static friction coefficient of the surface where the magnet 213 and the movable iron core 212 abut is represented by μ and the adsorption force is represented by N, the maximum static friction force F can be represented as F = μN. The force input connecting member, the force transmitting connecting member or the holding member 214, and the movable iron core 212, in which the force input connecting member or the movable iron core 212 tries to move relative to each other in the contact surface, restrains rotation. FIG. 8B shows a state in which a magnetic field is generated in the direction of repulsion with the magnet 213 by supplying electricity to the coil 211, and the magnet 213 and the movable core 212 are separated. Since the magnet 213 and the movable core 212 are separated, the above-mentioned maximum static friction does not act and rotation is not restrained. When the current supply is stopped, the movable core 212 is attracted by the magnetic field of the magnet 213 and abuts again. As described above, by providing the rotation control device 210 for suppressing the rotation, it is possible to control the relative movement between the two members having the same rotation axis depending on whether or not the coil 211 is energized.

When no current is applied, even if an external force exceeding the stationary maximum frictional force acts on the members, the members can be prevented from being damaged only by sliding the contact surface. In the case of energization, the suppression force can be increased by changing the direction in which the current flows so that the direction of the magnetic field generated by the coil 211 is the direction in which the attractive force increases.

9A and 9B are explanatory diagrams showing an example of the rotation control device. The rotation control device 220 of FIG. 9A includes a force input coupling member, a force transmission coupling member or a gripping member, that is, a movable iron core 222 having a surface that contacts the member 224, a bobbin, a lead wire and a copper wire not shown. And a spring 223 for urging the movable core 222 to abut against the member 224, and a fixing portion 225 for fixing one end of the spring 223. FIG. 9A shows a state in which the coil 221 is not energized, and the movable core 222 is brought into contact with the member 224 by the spring 223, so that the restraining force described in FIG. Do not move relatively, but prevent rotation. In FIG. 9B, when the coil 222 is energized, the movable core 222 moves in the direction opposite to the biasing force of the spring 223, and the member 224 and the movable core 222 are separated. Since the member 224 and the movable core 222 are separated, the above-mentioned maximum static friction does not act and rotation is not restrained. When energization is stopped, the movable core 222 abuts on the member 224 by the biasing force of the spring 223.

The rotation control device 220 suppresses the relative movement of the members by the frictional force, so that even if a force exceeding the stationary maximum frictional force acts on the members, each member is broken due to the sliding of the contact surface. You can prevent.

The rotation control device 220 can increase the restraining force by changing the direction of the current flowing through the coil 222 and making the moving direction of the movable core 222 the same as the direction of the biasing force by the spring 223. A combination of the rotation control device using the magnet shown in FIG. 8 and the rotation control device using the spring shown in FIG. 9 may be used as a new rotation control device.

FIG. 10 is an explanatory view showing an example of the rotation control device. The rotation control device 230 shown in FIG. 10 includes a force input coupling member, a force transmission coupling member or a gripping member 236, a contact plate 235 disposed on the member, and a coil (not shown) including a bobbin, a lead wire and a copper wire. 232, a movable core 231 rotatably supported coaxially with the coil 232, a magnetic body 234 filled between the movable core 231 and the contact plate 235, a magnetic body 234, and a contact plate 235 And a yoke 233 sealingly containing a part of the movable core 231. The magnetic body 234 may be, for example, magnetic fluid or magnetic powder. When the coil 232 is not energized, the rotation control device 230 does not generate a restraining force that prevents relative movement between the contact plate 235 and the movable iron core 231. When the coil 232 is energized, a magnetic circuit is formed between the movable core 231, the magnetic body 234, the contact plate 235, and the yoke 233, and the magnetic body 234 moves relative to the contact plate 235 and the movable core 231. Deter As described above, the rotation control device 230 can control the relative movement suppression of the contact plate 235 and the movable iron core 231 depending on whether or not the coil 232 is energized.

11A and 11B are explanatory diagrams showing an example of the rotation control device. The rotation control device 240 of FIG. 11A includes a force input coupling member, a force transmission coupling member or gripping member 243, a hole 244 provided in the member 243, a movable iron core 242 that can be fitted in the hole 244, and a movable It is provided coaxially with the iron core 242, and is comprised from the coil 241 which consists of a bobbin and a lead wire which are not shown in figure and a copper wire. FIG. 11B shows a state in which the movable core 242 is fitted in the hole 244. In this state, the member 243 and the movable core 242 can not move relative to each other in the direction perpendicular to the movable direction of the movable core 242, so that the rotation is suppressed. FIG. 11A shows a state in which the coil 241 is energized so as to move the movable core 242 away from the hole 244. Since the movable core 242 is not fitted in the hole 244 of the member 243, the rotation is not restrained. As described above, the rotation control device 240 can control the relative movement suppression of the member 244 and the movable iron core 242 by the presence or absence of the energization to the coil 241.

12A and 12B are explanatory diagrams showing an example of the rotation control device. The rotation control device 250 shown in FIG. 12A corresponds to a rotation shaft 257 shared by a force input coupling member, a force transmission coupling member or a gripping member (not shown), a projection 256 provided on the rotation shaft 257 and a projection 256 A movable core 252 having a movable projection 255 and a movable projection 255, a spring 253 for biasing the movable iron core 252 in the direction of the rotation shaft 257, a fixed portion 254 for fixing one end of the spring 253, and coaxial with the movable iron core 252 , And a coil 251 which is not shown and which is not shown and which comprises a lead wire and a copper wire. The movable core 252 is disposed so as to be movable in the direction orthogonal to the axial center direction of the rotation shaft 257. In the rotation control device 250 of FIG. 12A, the movable core 252 is urged in the direction of the rotation shaft 257 by the spring 253 so that the movable core 252 and the projection 256 come into contact with each other. It prevents movement to the side, that is, prevents the rotation shaft 257 from rotating. The rotation control device 250 of FIG. 12B shows a state in which the movable core 252 is moved in the direction opposite to the direction of the biasing force of the spring 253 by supplying a current to the coil 251. In this case, the projection 256 and the movable projection 255 do not abut each other, and the rotation shaft 257 can rotate in the arrow direction. As described above, the suppression of the rotation of the rotating shaft 257 can be controlled by the presence or absence of energization to the coil 251.

13A and 13B are explanatory diagrams showing an example of the rotation control device. The rotation control device 260 of FIG. 13A includes a coil spring 263 shared by a force input coupling member, a force transmission coupling member or a gripping member (not shown), a coil spring 263 coaxially arranged with the rotation shaft 264, and a coil spring 263. A fixed portion 265 for fixing one end of the coil, a movable iron core 262 supported at the other end different from the fixed portion 265 of the coil spring 263, and a bobbin, lead wire and copper wire arranged coaxially with the movable iron core 262 And the coil 261 which consists of. When the outer diameter of the rotating shaft 264 is D1 and the inner diameter of the coil spring 263 is D2, the relationship of D1> D2 is set. Since the outer diameter D1 of the rotary shaft 264 is larger than the inner diameter D2 of the coil spring 263, the coil spring 263 generates a clamping force against the rotary shaft 264 and generates a restraining force that prevents the rotation of the rotary shaft 264. ing. FIG. 13B shows a state in which the coil 261 is energized to move the movable core 262 in the axial direction. Since one end of the coil spring 263 is engaged with the movable core 262, the movable iron core 262 moves to push open both ends of the coil spring 263. When both ends of the coil spring 263 are pushed open, the inner diameter D2 of the coil spring 263 is increased, and the tightening force on the rotation shaft 264 is weakened. The weakening of the tightening force on the rotating shaft 264 allows the rotating shaft 264 to rotate. As described above, the rotation suppression of the rotating shaft 264 can be controlled by the presence or absence of energization to the coil 261.

14A and 14B are explanatory diagrams showing an example of the rotation control device. The rotation control device 270 of FIG. 14A includes a rotating shaft 274 shared by a force input connecting member, a force transmitting connecting member or a gripping member (not shown), and a split pin 273 having a bending R portion along the curvature of the rotating shaft 274. A fixed part 275 for fixing one end of the split pin 273, a movable core 272 supported by the other end different from the fixed part 275 of the split pin 273, a bobbin or lead arranged coaxially with the movable core 272 and not shown It is comprised from the coil 271 which consists of a wire | line and a copper wire. Assuming that the outer diameter of the rotating shaft 274 is D3 and the inner diameter of the split pin in the direction parallel to the axial direction of the movable core 272 at the bending R portion of the split pin 273 is D4, the relationship of D3> D4 is set. Since the outer diameter D3 of the rotating shaft 274 is larger than the inner dimension D4 of the split pin 273, the split pin 273 generates a tightening force on the rotating shaft 274, and generates a restraining force that prevents the rotation of the rotating shaft 274. doing. FIG. 14B shows a state in which the coil 271 is energized to move the movable core 272 in the axial direction. Since one end of the split pin 273 and the movable core 272 are engaged, the movable core 272 moves to push open both ends of the split pin 273. When both ends of the split pin 273 are pushed open, the inner dimension D4 of the split pin 273 becomes large, and the tightening force on the rotation shaft 274 becomes weak. The weakening of the tightening force on the rotating shaft 274 allows the rotating shaft 274 to rotate. As described above, the rotation suppression of the rotating shaft 274 can be controlled by the presence or absence of the energization to the coil 271.

As described above, the rotation control device is configured to suppress the rotation around the rotation axis when the coil is not energized. When the coil is energized, the force for suppressing the rotation around the rotation axis can be reduced, and each member can rotate around the rotation axis.

FIG. 15 is an explanatory view showing an object gripping system 500 using the end effector 530 described above. The object gripping system 500 includes an object gripping control unit 510, a gripping subject 518, an end effector 530 gripping the gripping subject 518, an arm unit 540 including the end effector 530, a gripping subject 518 and an end effector 530, And an imaging device 520 for observing the arm portion 540. The object gripping control unit 510 includes an image processing unit 513 that processes information of the imaging device 520, a gripping state detection unit 514 that processes information of a force sensor (not shown) mounted on the end effector 530, and an end effector 530. A power control unit 516 that controls a power unit 517 that provides an operating force to operate the object, a rotation control unit 515 that controls the end effector 530 to have a predetermined shape, an arm control unit 512 that controls an arm operation, The operation plan of the arm unit 540 or the end effector 530 to be connected to the processing unit 513, the grasping state detection unit 514, the power control unit 516, the rotation control unit 515, and the arm control unit 512 and hold the grasped object 518 Sending a command value to the arm unit 540 or the end effector 530 based on the operation plan, or Information from the arm portion 540 and the end effector 530 (e.g., position information and force information, such torque information) and the central control unit 511 to receive, and a. The imaging device 520 may be, for example, a video camera using a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) as an imaging element. In addition, at least two or more video cameras may be installed in the imaging device 520 so that stereo vision can be performed.

FIG. 16 is a flowchart 600 illustrating an operation of gripping the object to be gripped by the object gripping system 500.
(601)
First, a command to hold the object to be held is received.
(602)
Information is acquired from the imaging device (603), and imaging information is input to the object gripping control unit.
(604)
Based on the input imaging information, the image processing unit recognizes the shape of the object to be grasped.
(605)
The recognized shape information is sent to the gripping operation database (606), and it is determined whether it matches the shape already stored. If it is a known shape, the grasping operation plan attached to the shape is quoted. If the shape is not in the database, shape information is newly created, a similar shape is searched, and a gripping operation plan based on the similar shape is cited.
(607)
The drive unit is operated based on the grasping operation plan quoted.
(608)
While operating the drive unit, the gripping state is monitored. Specifically, the output of a force sensor mounted on the end effector is monitored.
(609)
As a result of monitoring the output of the force sensor, when a predetermined force sensor output is obtained, it is determined that the grasping of the object to be grasped is completed. On the other hand, when a predetermined force sensor output can not be obtained, it is determined that the gripping of the gripping target is not completed, and the drive unit operation and the gripping state monitoring are continued.
(610)
When the gripping operation is completed, the procedure of the driving unit operation is registered in the gripping operation database as a gripping operation plan, and is used for the subsequent gripping operations. When the gripping operation is completed, the arm part operates or the moving means mounted with the arm part moves to convey and position the object to be gripped to a predetermined place. Although details are omitted, environmental information of a predetermined place is observed by an imaging device, a placement operation is planned, a driving unit is operated based on the plan, and predetermined information is monitored while monitoring position information of a gripping object by the imaging device. The grip state may be released when it is determined that the positioning is performed.

DESCRIPTION OF SYMBOLS 1 ... 1st support member, 2 ... 2nd support member, 3 ... Fixed holding member, 4 ... 4th support member, 5 ... 3rd support member, 6, 101 ... Force input connection member, 7, 8 , 9, 11, 13, 16, 17, 19, 22, 24 ... rotating shaft, 10, 102 ... first gripping member, 12, 106 ... first force transmission connecting member, 14, 107 ... first restraint Connection member, 15, 103 ... second grip member, 18, 108 ... second force transmission connection member, 20, 109 ... second restraint connection member, 21, 104 ... third grip member, 23, 110 ... Third force transmission coupling member 25, 105: fourth gripping member 50, 51: gripping object 100: articulated finger portion 200: end effector 112: first buffer member 113: second Buffer member 114, third buffer member 115,

fourth buffer member

115, 20, 121, 122, 123, 124, 125, 126, 127, 128, 129 ... rotating shaft, 210, 220, 230, 240, 250, 260, 270 ... rotation control device, 211, 221, 232, 241, 251 261, 271: coil, 212, 222, 231, 242, 252, 262, 272: movable core, 213: magnet, 214: force input coupling member, force transmission coupling member or gripping member, 223, 253: spring, 224 ... Force input coupling member, force transmission coupling member or gripping member, 225, 254, 265, 275 ... Fixing portion, 233 ... Yoke, 234 ... Magnetic body, 235 ... Contact plate, 236, 243 ... Force input coupling member, force Transmission connection member or gripping member, 244: hole, 255: movable projection, 256: projection, 257, 264, 274: rotation shaft 263 ... coil spring, 273 ... split pin, 500 ... object gripping system, 510 ... object gripping control unit, 511 ... central control unit, 512 ... arm control unit, 513 ... image processing unit, 514 ... gripping state detecting unit, 515 ... Rotation control unit, 516 ... power control unit, 517 ... power unit, 518 ... gripping object, 520 ... imaging device, 530 ... end effector, 540 ... arm unit

Claims

An end effector for gripping a gripping object, comprising: a force input coupling member, a gripping member, a force transmission coupling member, and a restraint coupling member,
At least one or more of the rotation shafts connecting the support member, the force input connection member, the grip member, the force transmission connection member, and the restraint connection member may be provided with a rotation control device. Feature end effector.
In the end effector according to claim 1,
The support member, a fixed gripping member, an articulated finger, and a power unit,
The articulated finger unit includes a first holding member, a second holding member, a third holding member, a fourth holding member, a first force transmission connection member, and a second force transmission connection. A member, a third force transmission coupling member, a first restraint coupling member, and a second restraint coupling member;
The fixed gripping member is connected to the support member,
The force input coupling member is rotatably supported by the support member,
The first gripping member shares a rotational axis at which the force input coupling member is rotatably supported at the support member,
The first force transmission connection member is rotatably supported at one end of the force input connection member,
The second force transmission coupling member is configured to rotate a force transmitted to the first force transmission coupling member by rotating the force input coupling member about the rotation axis supported by the support member. Transmit to the force transmission connecting member,
The third force transmission coupling member transmits the force transmitted to the second force transmission coupling member to a fourth holding member,
The third gripping member is rotatably connected to the second gripping member,
In the first restraint connecting member, the rotation shaft shared by the first holding member and the second holding member, the first force transmission connecting member, and the second force transmission connecting member are shared. Connect the rotating shaft
The second restraint coupling member is provided on a rotation shaft shared by the second force transmission coupling member and the third force transmission coupling member, a second holding member, and both the first holding member Connect a rotating shaft that does not share any of the three gripping members,
The third force transmission connection member is provided on the fourth grip member, and is a rotation shaft shared with the second force transmission connection member and the second restraint connection member, which is not shared with the third grip member. Connect the axis and
The end effector characterized in that the power unit inputs a force to the force input connecting member.
In the end effector according to claim 1,
The rotation control device comprises a magnet, a movable core, and a coil,
The magnet is disposed on the force input coupling member, the force transmission coupling member, or the gripping member,
The movable core has a surface that contacts the magnet in a facing manner.
An end effector characterized in that the magnet and the movable core are in contact when the coil is not energized, and the magnet and the movable core are separated when the coil is energized.
In the end effector according to claim 1,
The rotation control device includes a movable iron core, a coil, a spring, and a fixing portion.
The movable core has a surface that comes into contact with the force input coupling member, the force transmission coupling member, or the gripping member,
The spring urges the movable iron core to abut the gripping member;
The fixing portion fixes one end of the spring,
When the coil is not energized, the movable iron core and the force input coupling member, the force transmission coupling member or the gripping member are in contact, and when the coil is energized, the movable iron core and the force input coupling member, the force transmission coupling member or An end effector characterized by being separated from a gripping member.
In the end effector according to claim 4,
The rotation control device comprises a magnet,
An end effector characterized in that the magnet and the movable core are in contact when the coil is not energized, and the magnet and the movable core are separated when the coil is energized.
In the end effector according to claim 1,
The rotation control device includes an abutment plate, a coil, a movable iron core, a magnetic body, and a yoke.
The contact plate is disposed on the force input coupling member, the force transmission coupling member, or the gripping member,
The movable core is rotatably supported coaxially with the coil.
The magnetic body is filled between the movable core and the contact plate,
The yoke includes and seals the magnetic body, the contact plate, and a part of the movable core.
When the coil is not energized, the magnetic body and the movable core slide relative to each other, and when the coil is energized, the magnetic body is magnetized to suppress relative slippage of the magnetic body and the movable core. An end effector characterized by
In the end effector according to claim 1,
The rotation control device includes a hole, a movable core, and a coil.
The hole is provided in the force input coupling member, the force transmission coupling member, or the holding member,
The movable core can be fitted in the hole,
The coil is provided coaxially with the movable core,
The end effector is characterized in that the movable core does not fit in the hole when the coil is not energized, and the movable core moves and fits in the hole when the coil is energized.
In the end effector according to claim 1,
The rotation control device includes a rotation shaft shared by the force input coupling member, the force transmission coupling member or the gripping member, a projection provided on the rotation shaft, and a movable projection abutting on the projection.
A movable iron core provided with the movable projection, and a spring biasing the movable iron core in the direction of the rotation axis;
A fixing part fixing one end of the spring, and a coil coaxially arranged with the movable core;
When the coil is not energized, the projection and the movable projection abut against each other to suppress the rotation of the rotating shaft, and when the coil is energized, the movable iron core moves and the projection does not contact the movable projection. An end effector that enables rotation of the rotation axis.
In the end effector according to claim 1,
The rotation control device fixes a rotating shaft shared by the force input connecting member, the force transmission connecting member or the gripping member, a coil spring coaxially arranged with the rotating shaft, and a fixed end of the coil spring. A movable iron core supported at the other end different from the fixed part of the coil spring;
An end having a relationship of D1> D2, provided that the coil is disposed coaxially with the movable core, and the outer diameter of the rotating shaft is D1, and the inner diameter of the coil spring is D2. Effector.
In the end effector according to claim 9,
An end effector characterized in that the movable iron core is moved so as to push and spread both ends of the coil spring when the coil is energized.
In the end effector according to claim 1,
The rotation control device includes a split pin having a rotation axis shared by the force input coupling member, the force transmission coupling member or the gripping member, a bending R portion along a curvature of the rotation axis, and one end of the split pin A fixed part to be fixed, a movable iron core supported by the other end different from the fixed part of the split pin, and a coil disposed coaxially with the movable iron core,
When the outer diameter of the rotating shaft is D3 and the inner dimension of the split pin in the direction parallel to the axial direction of the movable iron core is D4 at the bending R portion of the split pin, D3> D4. End effector.
In the end effector according to claim 11,
An end effector characterized in that the movable iron core is moved so as to push and spread both ends of the coil spring when the coil is energized.
An end effector according to any one of claims 1 to 12, an arm unit, an imaging device, a gripping state detection unit, and an object gripping control unit.
The arm unit is mounted on the end effector to position the end effector.
The imaging device captures an image of the end effector or an object to be grasped,
The grip state detection unit is disposed in the rotation control device, the arm unit, the imaging device, or the end effector, and when the end effector contacts the grip target object or grips the grip target object Detect the gripping force of the
The object gripping system, wherein the object gripping control unit controls the rotation control device, the arm unit, or the imaging device based on information of the gripping state detecting unit.
In the object gripping system according to claim 13,
The object gripping control unit inputs and outputs information from each unit: a rotation control unit that controls the rotation control device, an arm control unit that controls the arm unit, the gripping state detection unit that detects a gripping state, and And a central control unit.