WO2019193994A1

WO2019193994A1 - Hand mechanism and picking robot

Info

Publication number: WO2019193994A1
Application number: PCT/JP2019/012019
Authority: WO
Inventors: 健児日高; 嘉将遠藤
Original assignee: Thk株式会社
Priority date: 2018-04-03
Filing date: 2019-03-22
Publication date: 2019-10-10
Also published as: JP7036303B2; DE112019001766T5; JP2019181585A

Abstract

A sensor provided to a finger part of this hand mechanism is easily exchanged. Provided is a hand mechanism having a plurality of finger parts, wherein: the finger parts are provided with first finger link parts that have sensors and are positioned at distal-end sides of the finger parts, second finger link parts that are positioned at proximal-end sides of the finger parts, and joint parts that connect the first finger link parts and the second finger link parts; and the first finger link parts are provided with detachable parts that include the sensors and can be detached, the detachable parts being provided closer to the distal-end sides of the finger parts than are the joint parts.

Description

Hand mechanism and picking robot

The present invention relates to a hand mechanism and a picking robot.

A hand mechanism, which is attached to a robot arm or the like and grips an object with a plurality of fingers, has been developed. For example, Patent Document 1 discloses a robot apparatus including a hand mechanism having a plurality of finger parts (multi-finger hand part) and a robot arm having the hand mechanism attached to the tip. In this Patent Document 1, a pressure sensor is provided at the fingertip of the finger portion, an actual contact position with respect to the object is detected based on the output of the pressure sensor, and position information of the object is detected based on the detected contact position information. It is described to correct.

Japanese Patent No. 5505138

The pressure sensor provided on the fingertip is less durable than other members in the hand mechanism and is easily damaged. Therefore, it may be necessary to replace the pressure sensor. However, if the relative position between the finger and the sensor is shifted when the pressure sensor is replaced, the position of the object is detected to be shifted, so that the position of the object may be misidentified. Therefore, when the user replaces only the pressure sensor, it is necessary to align the pressure sensor at the fingertip with high accuracy. Therefore, it is difficult for the user to replace only the pressure sensor. On the other hand, when the pressure sensor is replaced, if the entire finger portion or the entire hand mechanism is replaced, there is a risk of cost and labor. Also, it is possible to replace the pressure sensor with the fingertip part, but if you try to remove the fingertip part from the joint, it will be necessary to disassemble the joint, and it will take time, and if the joint can not be assembled correctly, It can be difficult to perform normal operation.

The present invention has been made in view of various circumstances as described above, and an object thereof is to easily replace a sensor provided on a finger portion of a hand mechanism.

One aspect of the present invention is a hand mechanism having a plurality of finger parts, wherein the finger parts have a sensor and a first finger link part located on a distal end side of the finger parts; A second finger link portion that is located on the proximal end side and is connected to the first finger link portion, and a connection portion between the first finger link portion and the second finger link portion with respect to the second finger link portion. A joint part that connects the first finger link part and the second finger link part so that the first finger link part is relatively movable, and the first finger link part is formed from the joint part. Is a hand mechanism that includes a detachable portion that is detachable on the tip side of the finger portion and includes the sensor.

One aspect of the present invention is a picking robot provided with the hand mechanism at the tip of an arm.

According to the present invention, the sensor provided on the finger portion of the hand mechanism can be easily replaced.

It is a figure which shows schematic structure of the picking robot which concerns on embodiment. It is a perspective view of the hand mechanism concerning an embodiment. It is a top view of the hand mechanism concerning an embodiment. It is a side view of a finger part of a hand mechanism concerning an embodiment. It is the figure which looked at the front-end | tip part side of the finger | toe part of the hand mechanism which concerns on embodiment from the direction of arrow A of FIG. It is a figure which shows the movable range of the 2nd joint part in the finger | toe part of the hand mechanism which concerns on embodiment. It is a figure which shows the internal structure of the 1st joint part in a finger part, and the 2nd finger link part of the hand mechanism which concerns on embodiment. It is a figure which shows the movable range of the 1st joint part in the finger | toe part of the hand mechanism which concerns on embodiment. It is a figure which shows arrangement | positioning of the pressure-sensitive sensor in the front end side of the 1st finger link part of the finger | toe part of the hand mechanism which concerns on embodiment. It is the figure which showed the structure of the 1st finger link part which concerns on embodiment. It is the figure which showed the structure of the 1st finger link part which concerns on embodiment. It is the figure which looked at the 1st finger link part from the wall surface side by the side of the extension direction of the 1st joint part in the state where the tip part and base end part concerning an embodiment were fitted. It is the figure which looked at the 1st finger link part from the wall surface side by the side of the direction of bending of the 1st joint part in the state where the tip part and base end part concerning an embodiment were fitted.

Hereinafter, an embodiment for carrying out the present invention will be described with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified.

According to the hand mechanism according to the present invention, since the detachable part including the sensor is configured to be detachable from the finger part, the sensor can be replaced together with the detachable part when replacing the sensor. At this time, since it is not necessary to disassemble the joint portion, it is possible to reduce the labor required for replacement. Further, since the sensor can be exchanged together with the detachable part, the alignment becomes easy. Further, it is possible to suppress replacement of unnecessary parts.

Further, the finger portion may include an electric wire through which a signal from the sensor passes, and the attachment / detachment portion may include a connection portion capable of separating and connecting the electric wire. Thereby, when exchanging a detachable part, it becomes possible to separate and connect the electric wire which leads to a sensor easily. A connector can be used for a connection part, for example.

The first finger link part may further include a base end part that detachably supports the attachment / detachment part and includes the joint part. Since the joint portion is included in the base end portion, it is not necessary to disassemble the joint portion when attaching / detaching the attachment / detachment portion from the base end portion.

The first finger link portion includes a cover that covers a fitting portion between the base end portion and the detachable portion in a state where the base end portion supports the detachable portion, and the base end portion is the detachable portion. And a second fastening member for fixing the cover to the base end portion or the attaching / detaching portion. The first fastening member for fixing the attaching / detaching portion to the base end portion. By fixing the detachable portion to the base end portion using the first fastening member, it is possible to suppress the detachable portion from being detached from the base end portion. Moreover, the fitting part of an attachment / detachment part and a base end part can be protected by providing a cover. This cover may further cover the connection part or the electric wire. If it does so, a connection part or an electric wire can be protected. Moreover, attaching and detaching the cover is facilitated by fixing the cover to the base end part or the attaching / detaching part using the second fastening member.

<Embodiment>
Here, a gripping system in which the hand mechanism according to the present invention is applied to a picking robot will be described. The gripping system is a system for gripping an object to be gripped using the hand mechanism 2 provided at the tip of the picking robot 1. FIG. 1 is a diagram showing a schematic configuration of a picking robot 1 according to the present embodiment. The picking robot 1 includes a hand mechanism 2, an arm mechanism 3, and a pedestal portion 4. A hand mechanism 2 is attached to one end of the arm mechanism 3. The other end of the arm mechanism 3 is attached to the pedestal portion 4. The hand mechanism 2 includes a base portion 20 connected to the arm mechanism 3 and four finger portions 21 provided on the base portion 20. The detailed configuration of the hand mechanism 2 will be described later.

<Arm mechanism>
The arm mechanism 3 includes a first arm link portion 31, a second arm link portion 32, a third arm link portion 33, a fourth arm link portion 34, a fifth arm link portion 35, and a connection member 36. Each arm link portion is provided with a motor (not shown) for rotating around the axis. With the arm mechanism 3 having such a configuration, for example, the arm mechanism 3 can be a mechanism having six degrees of freedom.

<Pedestal part>
The pedestal portion 4 incorporates a control device (not shown) for controlling the hand mechanism 2 and the arm mechanism 3. The control device includes a plurality of drivers that generate drive signals for driving the motors provided in the hand mechanism 2 and the arm mechanism 3 so that the drive signals from the drivers are supplied to the corresponding motors. Composed. In addition, a signal from a pressure sensor 70 described later is input to the control device. The control device includes a computer having an arithmetic processing device and a memory. The control device stores a predetermined control program, and controls the hand mechanism 2 and the arm mechanism 3 by executing this program.

<Hand mechanism>
Next, the configuration of the hand mechanism 2 will be described with reference to FIGS. FIG. 2 is a perspective view of the hand mechanism 2. FIG. 3 is a top view of the hand mechanism 2. In FIG. 3, the arrows indicate the rotation movable ranges of the finger portions 21. As shown in FIGS. 2 and 3, in the hand mechanism 2, the four fingers 21 on the base portion 20 are centered on the axis in the longitudinal direction of the hand mechanism 2 (direction perpendicular to the paper surface in FIG. 3). On the circumference, they are arranged at equiangular intervals (ie, 90 deg intervals). The four finger portions 21 all have the same structure and the same length. However, the operation of each finger 21 is controlled independently.

4 to 9 are diagrams for explaining the configuration of the finger portion 21 of the hand mechanism 2 and its driving mechanism. FIG. 4 is a side view of the finger part 21. In FIG. 4, the base portion 20 and a part of a second finger link portion 212 of the finger portion 21 to be described later are shown in a transparent state, and the internal structure thereof is also shown. FIG. 5 is a view of the distal end side of the finger portion 21 as viewed from the direction of arrow A in FIG.

2 and 4, each finger portion 21 has a first finger link portion 211, a second finger link portion 212, and a base end portion 213. The base end portion 213 of the finger portion 21 is connected to the base portion 20. Here, the base end portion 213 is connected to the base portion 20 so as to be rotatable about the longitudinal axis of the finger portion 21 (direction perpendicular to the paper surface in FIG. 3) with respect to the base portion 20, as indicated by an arrow in FIG. Yes. In the finger part 21, one end of the second finger link part 212 is connected to the base end part 213. A second joint portion 23 is formed at a connection portion between the second finger link portion 212 and the base end portion 213. As shown in FIGS. 4 and 5, in the finger portion 21, one end of the first finger link portion 211 is connected to the other end of the second finger link portion 212. A first joint portion 22 is formed at a connection portion between the first finger link portion 211 and the second finger link portion 212.

Further, as shown in FIG. 4, a second motor 52 and a third motor 53 are provided inside the base portion 20. The third motor 53 is a motor for rotating the base end portion 213 around its axis. The rotational force of the third motor 53 is transmitted to the rotation shaft of the base end portion 213 via the gear, so that the base end portion 213 is rotationally driven, and accordingly, the finger portion 21 is within the range indicated by the arrow in FIG. The whole is rotationally driven. The second motor 52 is a motor for driving the second finger link part 212 to rotate relative to the base end part 213 in the second joint part 23. The rotational force of the second motor 52 is transmitted to the rotation shaft of the second finger link unit 212. As a result, the second finger link portion 212 is rotationally driven relative to the base end portion 213 within the range indicated by the arrow in FIG. As shown in FIG. 6, the second joint portion 23 is formed to be able to bend and extend. The driving force by the second motor 52 and the driving force by the third motor 53 are configured to be transmitted independently to the operation target.

Next, the drive mechanism of the first joint portion 22 will be described with reference to FIG. FIG. 7 is a diagram illustrating an internal structure of the first joint portion 22 and the second finger link portion 212 in the finger portion 21. Two

bevel gears

61 and 62 that are fitted to each other are provided inside the first joint portion 22. One bevel gear 61 is connected to the rotation shaft of the first finger link portion 211 in the first joint portion 22. Further, a first motor 51 is provided inside the second finger link portion 212, and the other bevel gear 62 is connected to the rotation shaft of the first motor 51. With such a configuration, when the first motor 51 is rotationally driven, the rotational force is transmitted to the rotation shaft of the first finger link portion 211 by the two

bevel gears

61 and 62, and the first finger link portion 211 is It is driven to rotate relative to the finger link unit 212. FIG. 8 is a diagram illustrating a movable range of the first joint portion 22 in the finger portion 21 realized by the driving force of the first motor 51. As shown in FIG. 8, the first joint portion 22 is formed to be able to bend and extend. That is, the first finger link portion 211 is formed to be movable relative to the second finger link portion 212.

Further, as shown in FIGS. 2, 4, 5, and 9, in this embodiment, a pressure-sensitive sensor 70 is provided on the distal end side of the first finger link portion 211 of the finger portion 21. The pressure sensor 70 is a sensor that detects an external force (pressure) acting on the distal end side of the first finger link portion 211. Further, as shown in FIG. 4, the pressure-sensitive sensors 70 are provided on both surfaces of the wall surface 215 on the bending direction side and the wall surface 216 on the extension direction side of the first joint portion 22 on the distal end side of the first finger link portion 211. ing. Here, in the present embodiment, the wall surface 215 on the bending direction side of the first joint portion 22 on the distal end side of the first finger link portion 211 is formed in a curved surface shape. Therefore, as shown in FIG. 9, a plurality of pressure-sensitive sensors 70 are arranged side by side along the curved surface shape on the wall surface 215 on the bending direction side of the first joint portion 22 at the distal end side of the first finger link portion 211. May be.

<First finger link part>
The first finger link portion 211 is configured to be divided into a distal end portion 2111 located on the distal end side and a proximal end portion 2112 located on the proximal end side. 10 and 11 are diagrams showing the structure of the first finger link portion 211. FIG. FIG. 10 is a view of the first finger link portion 211 as viewed from the wall surface 216 side of the first joint portion 22 on the extending direction side, and is a view in a state where the distal end portion 2111 and the proximal end portion 2112 are divided. FIG. 11 is a view of the first finger link portion 211 as viewed from the side of the wall surface 215 on the bending direction side of the first joint portion 22, and shows a state in which the distal end portion 2111 and the proximal end portion 2112 are divided. FIG. 12 is a view of the first finger link portion 211 as viewed from the wall surface 216 side on the extending direction side of the first joint portion 22 in a state where the distal end portion 2111 and the proximal end portion 2112 are fitted. FIG. 13 is a view of the first finger link portion 211 viewed from the side of the wall surface 215 on the bending direction side of the first joint portion 22 in a state where the distal end portion 2111 and the proximal end portion 2112 are fitted. In the first finger link portion 211, the first joint portion 22 is provided on the proximal end portion 2112 side, and the pressure sensor 70 is included in the distal end portion 2111. In addition, the front-end | tip part 2111 in this embodiment corresponds to the attachment / detachment part in this invention, and the pressure-sensitive sensor 70 in this embodiment corresponds to the sensor in this invention.

On the wall surface 216 side of the distal end portion 2111 on the extending direction side, a convex portion 80 that protrudes toward the proximal end portion 2112 side is provided. Further, on the wall surface 216 side of the proximal end portion 2112 on the extending direction side, a recessed portion 81 that is recessed from the distal end portion 2111 side toward the first joint portion 22 side so that the convex portion 80 of the distal end portion 2111 is fitted. Is provided. In addition, in the front-end | tip part 2111, the location where the convex part 80 and the recessed part 81 fit is called the fitting part 800. FIG. Therefore, the distal end portion 2111 can be attached to the proximal end portion 2112 by moving the distal end portion 2111 from the distal end side of the first finger link portion 211 toward the proximal end side, and the distal end portion 2111 is attached to the first finger link portion 2112. By moving the link portion 211 from the proximal end side toward the distal end side, the distal end portion 2111 can be detached from the proximal end portion 2112. Therefore, the distal end portion 2111 is detachable on the distal end side of the finger portion 21 relative to the first joint portion 22.

The distal end portion 2111 is fixed to the proximal end portion 2112 using two male screws 90 in a state where the convex portion 80 is fitted to the concave portion 81 in the fitting portion 800. The base end portion 2112 is provided with two through holes 91 penetrating from the wall surface 215 on the bending direction side to the wall surface 216 side on the extending direction side. The through hole 91 opens in the recess 81. Male screws 90 are inserted into the through holes 91 from the wall surface 215 side on the bending direction side. A screw hole 82 is formed in the convex portion 80 of the tip portion 2111 at a position corresponding to the through hole 91 in a state where the convex portion 80 is fitted in the concave portion 81. A female screw corresponding to the male screw 90 is formed in the screw hole 82. The male screw 90 that has passed through the through hole 91 of the base end portion 2112 is fastened to the screw hole 82 of the front end portion 2111, whereby the front end portion 2111 is fixed to the base end portion 2112. In the present embodiment, the male screw 90 corresponds to the first fastening member in the present invention.

The electric wire extending from each pressure sensor 70 is connected to the connector 85 via the flexible cable 71. The flexible cable 71 is an electric wire in which flat conductors are arranged in parallel and covered with an insulator, and has flexibility. The connector 85 is fixed to the substrate 86, and the substrate 86 is fixed to the wall surface 216 of the distal end portion 2111 on the extending direction side by a male screw 87. A connector 92 that is paired with the connector 85 is connected to one end of a flexible cable 93 wired inside the second finger link portion 212. The flexible cable 93 is wired from the second finger link part 212 to the pedestal part 4 inside the finger part 21, and the other end of the flexible cable 93 is connected to the control device. Therefore, by connecting the connector 92 on the second finger link part 212 side to the connector 85 on the first finger link part 211 side, the output signal from each pressure sensor 70 can be sent to the control device. In the present embodiment, the connector 85 corresponds to the connection portion in the present invention.

The first finger link portion 211 has a flexible cable 71 wired to the distal end portion 2111 and a flexible wire wired to the first finger link portion 211 with the distal end portion 2111 fixed to the proximal end portion 2112. A cover 2113 that covers the cable 93, the connector 85, the connector 92, and the substrate 86 is attached. The cover 2113 is fixed to the tip portion 2111 using a male screw 88. A screw hole 89 corresponding to the male screw 88 is provided on the wall surface 216 side of the distal end portion 2111 on the extending direction side. The cover 2113 is fixed by inserting the male screw 88 from the outside of the cover 2113 into the screw hole 89 and tightening it. Note that the cover 2113 is not always necessary. In the present embodiment, the male screw 88 corresponds to the second fastening member in the present invention.

In the first finger link portion 211 configured as described above, the distal end portion 2111 can be attached to and detached from the proximal end portion 2112. That is, the distal end portion 2111 can be removed from the finger portion 21 by removing the cover 2113 and the two male screws 90 and further removing the connector 92 on the second finger link portion 212 side from the connector 92 on the distal end portion 2111 side. . In addition, the cover 2113 and the two male screws 90 are attached with the distal end portion 2111 fitted to the proximal end portion 2112, and the connector 92 on the second finger link portion 212 side is connected to the connector 92 on the distal end portion 2111 side. By doing so, the distal end portion 2111 can be attached to the finger portion 21. Therefore, when it is necessary to replace the pressure sensor 70, it is only necessary to replace the tip 2111. Here, in the hand mechanism having a structure in which the first finger link portion 211 cannot be divided into the tip end portion 2111 and the base end portion 2112, when the pressure sensor 70 needs to be replaced, only the pressure sensor 70 is replaced. If it tries to do it, it will be necessary to position the pressure-sensitive sensor 70 with high precision, and it will be troublesome. Moreover, when the pressure-sensitive sensor 70 is attached in a shifted state, there is a possibility of misidentifying the position of the object. Further, for example, it is conceivable to replace the pressure sensor 70 with the first finger link portion 211. However, when exchanging the first finger link portion 211, it is necessary to disassemble the first joint portion 22, which is troublesome. In addition, for example, it is conceivable to replace the pressure-sensitive sensor 70 with the finger part 21, but in this case, it is necessary to disassemble the second joint part 23, which is also troublesome. Further, for example, the pressure sensor 70 may be replaced with the hand mechanism 2, but many parts other than the pressure sensor 70 are replaced, which increases costs. On the other hand, since the tip part 2111 is detachably provided, the pressure-sensitive sensor 70 can be exchanged by exchanging only the tip part 2111. Therefore, a part having a complicated structure such as the first joint part 22 is disassembled. This is unnecessary, and the pressure sensor 70 can be exchanged with a simple operation. And the convex part 80 and the recessed part 81 fit, and the front-end | tip part 2111 is fixed to the base end part 2112 with the two male screws 90, and alignment of the pressure sensor 70 is performed without a user being conscious. Is called. Further, since only the tip portion 2111 needs to be replaced, fewer parts need to be replaced than necessary. Thus, by providing the tip portion 2111 so as to be detachable, the pressure-sensitive sensor 70 can be replaced more easily and at a lower cost. Further, by providing the connector 85, it is not necessary to replace all the wiring inside the finger portion 21, so that it is possible to suppress labor.

It should be noted that the tip portion 2111 can be replaced not only when the pressure-sensitive sensor 70 is damaged or deteriorated. For example, the tip portion 2111 may be replaced when it is desired to replace with a pressure-sensitive sensor having different performance or when a sensor that detects a physical quantity other than pressure is desired. Also, a tip portion 2111 having a different shape may be prepared and replaced depending on the object. When a tip portion 2111 with higher performance is developed, the tip portion 2111 with higher performance is replaced. May be.

In this embodiment, the connector 85 is fixed to the distal end portion 2111 and the flexible cable 93 is extended from the second finger link portion 212 side to connect the connector 92. However, the method of connecting the wires is not limited to this. For example, the connector 92 on the second finger link portion 212 side may be fixed to the proximal end portion 2112 and the flexible cable 71 on the distal end portion 2111 side may be extended to connect the connector 85. Further, it is not always necessary to use the connector 85 for connecting the electric wires. For example, each of the convex portion 80 and the concave portion 81 may be provided with a contact leading to the flexible cable, and the electric wire may be connected so that the corresponding contact contacts when the convex portion 80 and the concave portion 81 are fitted. In this case, the contact provided on the convex portion 80 corresponds to the connecting portion in the present invention.

Further, the respective shapes at the places where the distal end portion 2111 and the proximal end portion 2112 are fitted are not limited to the shapes of the convex portion 80 and the concave portion 81 shown in FIG. Moreover, in this embodiment, although the front-end | tip part 2111 is being fixed to the base end part 2112 using the two male screws 90, the fixing method is not restricted to this. For example, it may be fixed using one screw or three or more screws, or may be fixed using a pin having no screw structure, or the convex portion 80 and the concave portion 81 are fitted. It may be fixed by having a structure that is automatically locked when it is done.

DESCRIPTION OF SYMBOLS 1 ... Picking robot, 2 ... Hand mechanism, 3 ... Arm mechanism, 21 ... Finger part, 22 ... 1st joint part, 211 ... 1st finger link part, 212 ... Second finger link part, 2111 ... distal end part (detachable part), 2112 ... proximal end part, 70 ... pressure-sensitive sensor, 85 ... connector (connecting part)

Claims

A hand mechanism having a plurality of fingers,
The fingers are
A first finger link portion that has a sensor and is located on a distal end side of the finger portion;
A second finger link portion located on the proximal end side of the finger portion and connected to the first finger link portion;
The first finger link portion and the second finger link portion are movable relative to the second finger link portion at a connection point between the first finger link portion and the second finger link portion. A joint part connecting the finger link part;
With
The first finger link portion includes a detachable portion that is detachable on the distal end side of the finger portion with respect to the joint portion and includes the sensor.
Hand mechanism.
The finger portion includes an electric wire through which a signal from the sensor passes,
The attaching / detaching portion includes a connecting portion capable of separating and connecting the electric wire,
The hand mechanism according to claim 1.
The first finger link part further includes a base end part that detachably supports the attachment / detachment part and includes the joint part,
The hand mechanism according to claim 1 or 2.
The first finger link part is
In a state where the base end portion supports the detachable portion, a cover that covers a fitting portion between the base end portion and the detachable portion;
A first fastening member that fixes the detachable portion to the base end portion in a state where the basal end portion supports the detachable portion;
A second fastening member for fixing the cover to the base end portion or the detachable portion;
Further comprising
The hand mechanism according to claim 3.
The hand mechanism according to any one of claims 1 to 4 is provided at a tip of an arm.
Picking robot.