JP5092128B2 - Robot hand and gear system - Google Patents

Description

  The present invention relates to a robot hand.

  In recent years, the working environment of robots has been expanding from indoors to outdoors, but not only performance but also cost has become a serious problem, and research on costs is increasing at international conferences on robotics and the like. In particular, the agricultural field is characterized by an emphasis on cost.

  As a conventional technique related to a robot, particularly a robot hand, for example, the following Non-Patent Document 1 discloses a robot hand having a mechanism for picking and placing using a pneumatic actuator that generates a vacuum state and a gripper having a simple shape at low cost. Techniques related to this are disclosed. Non-Patent Document 2 below discloses a technique related to a robot hand having a mechanism for performing picking without using an actuator and a mechanism for performing placing using a hydraulic cylinder. Non-Patent Document 3 below discloses a technique related to a robot hand having a mechanism for performing picking without using an actuator and a mechanism for performing placing using a wire and a small DC motor.

Setiawan et al., “A Low Cost Gripper for an Apple Picking Robot”, Proceedings of the 2004 IEEE ICRA, pages 4448-4453. Iida et al., “Development of Waterhaven harvesting robot (ii) watermelon harvesting gripper,” Proceedings of the Symposium on Automation and Robotic. 2, pages 17-24 Sakai et al., “Watermellon Harvesting Exploration of A Heavy Material Handling Agricultural Robot with LQ Control,” Proceedings of the 2002, pages IEEE7777.

  However, in the technologies described in Non-Patent Document 1, Non-Patent Document 2 and Non-Patent Document 3, the actuator is used in Placing, which is expensive, wiring becomes complicated, and durability is low. There is a problem that advanced knowledge is also required for maintenance.

  Therefore, an object of the present invention is to solve the above-described problems and provide a robot hand that does not use an actuator for Picking and Placing.

  As one means for solving the above-described invention, the robot hand includes a cylinder body in which a cylindrical space is formed, and a housing gear, a gravity gear, a housing gear, and a gravity arranged in the cylindrical space of the cylinder body. A state gear combined with the gear, an output bar having a shaft and a plate fixed to the shaft and connected to the state gear, a plurality of arms rotatably coupled to the cylinder body, a plurality of arms and a rotation And a passively restrained hand that can be coupled.

  In this means, it is also desirable that at least one of the plurality of arms controls the open / closed state of the passive restraint hand according to the position of the plate of the output bar, and the state gear includes the shaft and the periphery of the shaft. A plurality of teeth arranged in a direction, the housing gear has an axis formed with a deep groove and a shallow groove combined with the plurality of teeth in the state gear, and the gravity gear has a plurality of teeth in the state gear. It is also desirable to have an axis on which irregularities combined with are formed.

  As another means for solving the above-described invention, a cylinder body in which a cylindrical space is formed, and a housing gear, a gravity gear, a housing gear, and a gravity gear arranged in the cylindrical space of the cylinder body are provided. A gear system having a state gear to be combined, a shaft and a plate fixed to the shaft, and an output bar connected to the state gear.

  In this means, although not limited, the state gear has a shaft and a plurality of teeth arranged in the circumferential direction of the shaft, and the housing gear is combined with the plurality of teeth in the state gear. It is also preferred to have an axis on which deep and shallow grooves are formed and the gravity gear has an axis on which irregularities combined with a plurality of teeth in the state gear are formed.

  As described above, the present invention can provide a robot hand that does not use an actuator for picking and placing.

  Embodiments of the present invention will be described below with reference to the drawings. However, the present invention can be implemented in many different modes and is not limited to the embodiments shown below. Note that in this specification, portions having the same or similar functions are denoted by the same reference numerals, and repeated description thereof is omitted.

  FIG. 1 is an overall view of a robot hand according to the present embodiment (hereinafter referred to as “the present robot hand”). As shown in FIG. 1, the robot hand 1 includes a cylinder body 2, a housing gear 3, a gravity gear 4, a state gear 5, an output bar 6, and a plurality of cylinder bodies 2 connected to the cylinder body 2. And a passive restraining hand 8 coupled to the plurality of arms 7 (note that the cylinder body 2 and the housing gear 3, the gravity gear 4, and the state gear incorporated therein) 5 and the output bar 6 are called a gear system).

  The cylinder body 2 is a part of a main configuration for storing the plurality of gears and forming a robot hand. The cylinder body 2 is provided with a cylindrical space (hereinafter simply referred to as “cylinder portion”) having both ends serving as cylinders, and the cylinder gear 3, the gravity gear 4, the state gear 5, and the like are provided in the cylinder portion. The output bar is stored.

  FIG. 2 is a view of the vicinity of the cylinder portion and the housing gear 3 in the cylinder body 2 (FIG. 2A is a top view, FIG. 2B is a side view, and FIG. 2C is a bottom view). The housing gear 3 is a gear combined with a state gear 5 to be described later, has a space hollowed out in a cylindrical shape, and has deep grooves 31 and shallow grooves 32 periodically formed in the circumferential direction. . The housing gear 3 is fixed to the cylinder portion of the cylinder body 2 and moves the position of the output bar 6 vertically according to the position of the teeth of the state gear 5. The housing gear 3 also has a function of restraining the gravity gear. The material of the gear is not particularly limited as long as it does not cause a large deformation due to stress. For example, a metal or an alloy such as iron or aluminum can be used.

  The gravity gear 4 is a gear combined with the state gear 5 like the housing gear 3. More specifically, the state gear 5 meshes with the state gear 5 immediately after the combination with the housing gear 3 is released, and the state gear 5 is rotated in the circumferential direction. Therefore, as shown in FIG. 3 (FIG. 3A is a top view, FIG. 3B is a side view, and FIG. 3C is a bottom view), the gravity gear 4 has a mountain-shaped unevenness at the lower end. Since the gravity gear 4 needs to be aligned with the state gear 5 in the axial direction, there is a space near the center of the gear shaft 41 to be combined with a part of the state gear shaft. Is formed. The gravity gear 4 is disposed in the space of the housing gear 3 of the cylinder portion 2 in the cylinder body 2 and is fixed by, for example, fitting with the housing gear 3 using, for example, a key 43 formed on the shaft 41. A top plate 42 is disposed outside the cylinder body 2 on the axis of the gravity gear 4 according to the present embodiment. The material of the gravity gear 4 is not particularly limited as long as it does not cause a large deformation due to stress, as in the case of the housing gear 3. For example, a metal or alloy such as iron or aluminum can be used.

  The state gear 5 rotates and vertically vibrates while meshing with the housing gear and the gravity gear alternately, and determines the state of Picking or Placing according to the rotation angle. The structure of the state gear 5 according to this embodiment is shown in FIG. 4A is a top view, FIG. 4B is a side view, and FIG. 4C is a bottom view. As shown in FIG. 4, the state gear 5 includes a disk 51, a shaft 52 disposed on the disk 51, and a plurality of teeth 53 with inclined tips disposed in the circumferential direction of the shaft. It is configured. The plurality of teeth are preferably arranged at equal intervals in the circumferential direction, and the number of teeth is preferably 3 from the viewpoint of stability, but is not limited thereto. In addition, as with the above, there is no particular limitation on this material as long as it does not cause large deformation due to stress. For example, a metal or an alloy such as iron or aluminum can be used.

  The output bar 6 is fixed to the state gear 5 and is displaced up and down according to the rotation and vibration of the state gear 5, and the opening and closing of the passive restraint hand is determined by the amount of the displacement. The output bar 6 includes a shaft 61 and a plate 62 fixed below the shaft 6. By moving the output bar 62 up and down, the lower arm 72 of the coupling link 7 can be pushed down or released to open and close the passive restraint hand 8.

  The plurality of arms 71 and 72 are coupled to the cylinder body 2 via, for example, screws 73 so as to be rotatable to the cylinder body 2 via screws 73, and the passive restraint hand 8 is also connected via screws 74. Coupled to be rotatable. As a result, the passive restraint hand 8, the plurality of arms 71 and 72, and the cylinder body form a coupling link so that picking and placing can be performed smoothly (see FIG. 1 again).

  In addition, one arm 72 of the plurality of arms is disposed such that a tip portion 721 thereof is in contact with the plate 62 of the output bar 6, and can move up and down as the output bar 6 moves up and down. FIG. 5 shows a state where the output bar is lowered, and FIG. 6 shows a state where the output bar is raised. As a result, the displacement of the output bar can be converted into the opening / closing amount of the force-constrained hand. As is clear from the above, the passive restraint hand 8 is for directly picking and placing a Pickik object, and a plurality of arms are connected to one passive restraint hand 8. Yes. Further, the number of fingers of the passive restraint hand is not particularly limited, but it is desirable to provide a plurality of fingers so as not to drop the picking object, specifically, 3 or more, more desirably 4 or more. Of course, it is desirable that a plurality of arms be connected to each passive restraint hand, and it is desirable that one end of at least one arm can be moved up and down in accordance with the up and down of the output bar. There are no particular restrictions on the material of the plurality of arms and the passive restraint hand, as in the case of the above configuration. For example, a metal or an alloy such as iron or aluminum can be used.

  Here, the tip of the arm will be described. For example, when the arm 72 is closed, picking is possible by making the tip 721 dig into the lower part of the object to be picked (and the object has a hook hole). If picked up, the picking operation is also possible by passing the arm 72 through the hook hole and hooking it.) Therefore, when it is assumed that an object to be used for picking has a gap in the lower part (for example, in the case of a spherical shape), special equipment is not necessary. For example, an object having no gap in the lower part (for example, In the case of a rectangular parallelepiped object), for example, it is useful to attach a gripping unit 73 shown in FIG. FIG. 7 is a schematic diagram of the robot hand when the gripping unit 73 is attached, and FIG. 8 is an explanatory diagram of the operation of the gripping unit 73.

  The gripping unit 73 includes a shaft 731 and a cam 732 that is attached to the shaft 731 and is rotatable about the shaft 731 at the tip (object side) of the arm. The gripping unit 73 is attached to each of the arms 72. The gripping unit 73 shown in FIGS. 7 and 8 also has a bearing 733 disposed between the cam 732 and the shaft 731 and a weight 734 disposed on the cam 732.

  The shaft 731 serves as the rotation center of the cam 732, and the material is not limited as long as this is the case. From the viewpoint of ease of manufacturing, it is preferable to select a material similar to that of the arm 72.

  A bearing 733 is disposed between the cam 732 and the shaft 731. This is preferable because the rotation becomes smoother. However, it is not limited as long as the cam 732 can be held and rotated, and may be omitted depending on circumstances.

  The cam 732 is pressed against the side surface of the object at the time of picking, and applies a force (friction force generated by a vertical drag between the cam and the object) to the side surface of the object, thereby enabling the picking of the object. . Although not limited thereto, the shape of the cam 732 shown in FIGS. 7 and 8 is such that the distance between the center of the shaft 731 and a point on the outer contour of the cam is not always constant in the circumferential direction, and is monotonous in the circumferential direction. It has a changing part. More specifically, for example, as shown in FIG. 8, when the distance between the center point of the shaft 731 and the contact point between the cam 732 and the object is d, the rotation angle θ (θ = θ = The cam 732 is formed so as to have a portion where the distance d increases monotonously as 0 ° increases (see FIG. 8A to FIG. 8C). It is also preferable to arrange a weight 734 on the cam 732 and adjust the inclination of the cam 732 so that the distance d is as small as possible when the cam 732 is not in contact with the cam 732. The long axis is horizontal.) In addition, since the cam 732 is attached to each of the arms 72 and the cams 732 of the plurality of arms 72 are similarly pressed against the side surface of the object, the cam 732 can be added isotropically to the object. As it rotates, the distance between the cams 732 and the force generated between them (force that presses the object from the side surface) can be adjusted, and even if the object does not have a gap at the bottom, picking and placing can be easily performed. Can do. The shape of the cam that exhibits the above effects is not limited. For example, an elliptical shape (see FIG. 8) focusing on the shaft 731 and an egg shape are suitable. The material of the cam 732 is not limited, but is preferably a material that has elasticity and can generate a large amount of friction. For example, rubber can be suitably used.

  With the above configuration, the robot arm having the gripping unit 73 can easily pick even an object that does not have a gap in the lower part.

  As described above, this robot hand can perform picking and placing without using an actuator due to the above configuration. More specifically, this hand robot realizes a mechanical system having a memory element by combining a plurality of gears, and in addition to this, a plurality of arms and a passive restraint hand are combined to use an actuator or a spring element. Picking and Placing can be performed smoothly without any problems. In particular, according to this robot hand, while picking objects through passive restraint hands and a plurality of arms, the top and bottom of the output bar and a plurality of arms are in contact with each other, so that each gear is picked. The effect of not transmitting the weight of the object, the weight of the arm or the passive restraint hand itself can be achieved, and the reliability can be further increased.

  When the smooth element may be sacrificed to some extent, the arm and the passive restraining hand may be integrally coupled to the cylinder body (hereinafter referred to as “integrated hand”) so as to be rotatable. In this case, the side that contacts the output bar and the tip side (the side that grips the object) of the integrated hand are arranged on the opposite side to the coupling point with the cylinder body, and when the output bar is lowered, the Placing is performed. When the output bar rises, it is possible to perform picking (for example, see the conceptual diagram of FIG. 9).

  The robot hand according to the present invention is, for example, an agricultural robot hand that picks and places a crop such as a watermelon or a pumpkin. -It can be used as an amusement robot hand and has industrial applicability.

It is a front view of the robot hand concerning this embodiment. It is a figure which shows the structure of the cylinder part vicinity and housing gear in the cylinder body which concerns on embodiment. It is a figure which shows the structure of the gravity gear which concerns on embodiment. It is a figure which shows the structure of the state gear which concerns on embodiment. It is a figure which shows the upper body in which the output bar of the robot hand which concerns on this embodiment fell. It is a figure showing the state where the output bar of the robot hand concerning this embodiment went up. It is a figure at the time of the holding unit being attached to the arm front-end | tip part of the robot hand which concerns on this embodiment. FIG. 8 is a more detailed explanatory diagram of the gripping unit shown in FIG. 7. It is a figure explaining the concept at the time of uniting an arm and a passive restraint hand.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Robot hand, 2 ... Cylinder body, 3 ... Body gear, 4 ... Gravity gear, 5 ... State gear, 6 ... Output bar, 7 ... Arm, 8 ... Passive restraint hand, 31 ... Deep groove, 32 ... Shallow groove, 41 ... axis, 42 ... top plate, 43 ... key, 51 ... disc, 52 ... axis, 53 ... tooth, 61 ... axis, 62 ... plate, 71, 72 ... arm, 73, 74 ... screw, 721 ... (arm Tip portion 73 ... gripping unit 731 ... shaft 732 ... cam 733 ... bearing 734 ... weight

Claims (2)

A cylinder body in which a cylindrical space is formed;
A housing gear that is fixedly disposed in the cylindrical space of the cylinder body, and has a deep groove and a shallow groove formed downward along the axial direction of the cylindrical space ; and
A shaft and a plurality of teeth arranged in a circumferential direction of the shaft, arranged in a cylindrical space of the cylinder body and restrained by the housing gear , wherein the plurality of teeth are the deep of the housing gear. A state gear which is movable in the vertical direction in the axial direction of the cylindrical space and rotatable in the circumferential direction in the cylindrical space of the cylinder body in combination with a groove and a shallow groove;
The lower end of the state gear of the state gear has a shaft formed with a mountain-shaped unevenness, is fixedly disposed in a cylindrical space of the cylinder body, and the unevenness is just after the combination with the housing gear is released. A gravity gear that meshes with a plurality of teeth and rotates the state gear in the circumferential direction of the axis of the cylindrical space ;
An output bar that has a shaft and a plate fixed to the shaft, is fixed to the lower side of the state gear, and is displaced up and down according to the rotation of the state gear ;
Is rotatably coupled through a screw to the cylinder body, the one of the tip portion the tip portion in association with the displacement of the output bar Rukoto arranged to contact with the lower side of the plate of the output bar is vertically The two arms and the two arms are rotatably joined via a screw to form a coupling link, and the tip of the arm is in a closed state when the plate of the output bar is on the top. , While the tip of the arm is open when the plate of the output bar is below, the tip is opened to release the object to be gripped. Have multiple sets of passive restraint hands,
The state gear rotates and moves up and down while meshing with the housing gear and the gravity gear,
The output bar moves up and down according to the vertical displacement of the state gear while meshing with the gravity gear ,
One tip of the two arms contacting the output bar moves up and down according to the vertical displacement of the output bar ,
A robot hand in which a passive restraint hand opens and closes corresponding to the upper and lower sides of the arm , and a gripping force for an object to be gripped is generated without power . A cylinder body in which a cylindrical space is formed;
A housing gear that is fixedly disposed in the cylindrical space of the cylinder body, and has a deep groove and a shallow groove formed downward along the axial direction of the cylindrical space ; and
A shaft and a plurality of teeth arranged in a circumferential direction of the shaft, arranged in a cylindrical space of the cylinder body, the plurality of teeth being combined with the deep groove and the shallow groove of the housing gear. A state gear capable of moving in the vertical direction in the axial direction of the cylindrical space and rotatable in the circumferential direction in the cylindrical space of the cylinder body ;
The lower end of the state gear of the state gear has a shaft formed with a mountain-shaped unevenness, is fixedly disposed in a cylindrical space of the cylinder body, and the unevenness is just after the combination with the housing gear is released. A gravity gear that meshes with a plurality of teeth and rotates the state gear in the circumferential direction of the axis of the cylindrical space ;
An output bar that has a shaft and a plate fixed to the shaft, is fixed to the lower side of the state gear, and is displaced up and down according to the rotation of the state gear ;
Is rotatably coupled through a screw to the cylinder body, the one of the tip portion the tip portion in association with the displacement of the output bar Rukoto arranged to contact with the lower side of the plate of the output bar is vertically The two arms and the two arms are rotatably joined via a screw to form a coupling link, and the tip of the arm is in a closed state when the plate of the output bar is on the top. , While the tip of the arm is open when the plate of the output bar is below, the tip is opened to release the object to be gripped. Have multiple sets of passive restraint hands,
The state gear rotates and moves up and down while meshing with the housing gear and the gravity gear,
The output bar moves up and down according to the vertical displacement of the state gear while meshing with the gravity gear ,
A gear system in which one tip of the two arms contacting the output bar moves up and down according to the vertical displacement of the output bar.

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