Robot hand

This application claims priority under 35 U.S.C. § 119(a) on Patent Application No. 2004-351481 filed in Japan on Dec. 3, 2004, the entire contents of which are hereby incorporated by reference.

The present invention relates to a robot hand that can perform manual procedures and the like by driving a plurality of fingers.

The device disclosed in, for example, JP 2001-287182A is an example of a conventional device of this type. Here, a drive-source motor is provided to joints of the fingers, a belt bridges an output shaft of the motor and a rotating shaft of the joint, and the rotation of the output shaft of the motor is transmitted to the rotating shaft of the joint via the belt, thereby rotating the joint. These motors and belts are provided to each joint in the finger, rotating each joint and thereby bending and extending the finger.

The degree of freedom of the fingers increases if each joint in the fingers is rotated independently. Complex operation of the robot hand is therefore possible, enabling not only grasping operations of objects, but also manipulation of grasped objects.

Furthermore, by providing touch sensors and/or force sensors to fingertips and other portions of the robot hand and detecting the grasping force, etc., of the robot hand, the functionality of the robot hand is improved.

However, while a wide variety of designs have been proposed other than the robot hand disclosed in JP 2001-287182A, the movement of robot hands has thus far failed to achieve that of human hands, which means that there exist many things which can be done with a human hand that cannot be done with a robot hand.

For example, in order to move an object 102 on the palm of a robot hand 101 in the direction of an arrow F while the robot hand 101 holds the object 102 as shown in FIG. 32 , the robot hand 101 must be made to perform an extremely complex movement, requiring a further increase in the degree of freedom, making it very difficult to realize such a movement. Additionally, an appropriate friction surface with the object 102 needs to be provided to the palm, which creates new problems in terms of the shape, material, and so on of the palm, rendering immediate realization impossible.

Further, while a method is conceivable in which a plurality of robot hands is prepared and the object on the palm of the robot hand is moved through the aid of another robot hand, further problems for consideration would arise, such as analysis of locations on the object for the other robot hand to come in contact with, recognition technology, technology for making a plurality of robot hands work in concord, and so on, rendering immediate realization impossible.

Accordingly, the present invention has been devised in light of these problems of the conventional art, and it is an object thereof to provide a technically viable robot hand capable of more complex handling of objects.

In order to resolve the problems described above, the robot hand of the present invention is such that a robot hand having a plurality of fingers is provided, at a location at which the robot hand touches the object, with a moving means for touching the object and moving the object.

With such a configuration, providing the moving means to a location such that it touches an object, when an object is grasped by the robot hand, makes it possible to move the object by the moving means while grasping the object, thereby enabling more complex handling of the object. Furthermore, as described below, a belt conveyor or the like may be used as the moving means, whereby viability is very high and control of which is easy.

The robot hand according to the present invention may be configured such that the moving means is provided to the palm side of the robot hand.

The robot hand according to the present invention may be configured such that the moving means is provided to the finger pad side of the robot hand.

With the above configurations, the object grasped by the robot hand can be moved within the hand.

The robot hand according to the present invention may be configured such that a plurality of moving means is provided, and moving speeds of the object by each moving means mutually differ.

The robot hand according to the present invention may be configured such that a plurality of moving means is provided, and moving directions of the object by each moving means mutually differ.

With the above configuration, the object cannot only be transported, but also rotated.

The robot hand according to the present invention may also be configured such that a plurality of moving means is provided, each moving means being provided to mutually non-parallel surfaces of the robot hand.

With this configuration, the object can be moved in a stable manner by each moving means because the moving means touch the object on mutually differing surfaces.

The robot hand according to the present invention may be such that the moving means is a belt conveyor.

The robot hand according to the present invention-may be configured such that the moving means is provided with elastic members which contain a plurality of pressure chambers, traveling waves being formed on the surface of the elastic members through sequential selective expansion of each pressure chamber, and an object, which touches the surfaces of the elastic members, being moved by the traveling waves on the surface of the elastic members.

The robot hand according to the present invention may be configured such that the moving means is provided with a plurality of polymer actuators and elastic members which are placed on the polymer actuators and latched together, traveling waves being formed on the surface of the elastic members through sequential selective extension of each polymer actuator, and an object, which touches the surfaces of the elastic members, being moved by the traveling waves on the surface of the elastic members.

The robot hand according to the present invention may be such that the moving means is a rotatingly driven roller.

FIG. 1 is a lateral view showing an embodiment of a robot hand according to the present invention.

FIG. 2 is a plan view showing the robot hand according to the embodiment shown in FIG. 1 from the palm side.

FIG. 3 is a rear view showing the robot hand according to the embodiment shown in FIG. 1 from the back of the hand side.

FIG. 4 is a figure showing a rotation operation of a thumb mechanism in the robot hand according to the present embodiment.

FIG. 5 is a partial cut-away view showing a location where a thumb sub base and main base are linked in the robot hand according to the present embodiment.

FIG. 6 is a figure showing a bending and extending operation of the thumb in the robot hand according to the present embodiment.

FIG. 7 is a view showing a partial cross-section of motors on the thumb sub base and the thumb mechanism in the robot hand according to the present embodiment.

FIG. 8 is a figure showing a rotation operation of an index finger mechanism in the robot hand according to the present embodiment.

FIG. 9 is a partial cut-away view showing a location where an index finger sub base and main base are linked in the robot hand according to the present embodiment.

FIG. 10 is a figure showing a bending and extending operation of an index finger in the robot hand according to the present embodiment.

FIG. 11 is a view showing a partial cross-section of motors on the index finger sub base and the index finger mechanism in the robot hand according to the present embodiment.

FIG. 12 is a figure showing a bending and extending operation of a middle finger mechanism in the robot hand according to the present embodiment.

FIG. 13 is a view showing a partial cross-section of motors on the main base and the middle finger mechanism in the robot hand according to the present embodiment.

FIG. 14 is a figure showing a bending and extending operation of a ring finger mechanism and a little finger mechanism in the robot hand according to the present embodiment.

FIG. 15 is a partial cut-away view showing a location where the ring finger mechanism and the little finger mechanism are linked to the main base in the robot hand according to the present embodiment.

FIG. 16 is a view showing a partial cross-section of motors on the main base, the ring finger mechanism, and the little finger mechanism in the robot hand according to the present embodiment.

FIG. 17 is a lateral view showing the robot hand according to the present embodiment with a moving mechanism revealed on the palm.

FIG. 18 is a plan view showing the robot hand according to the present embodiment with the moving mechanism revealed on the palm.

FIG. 19 is a perspective view showing the moving mechanism of FIG. 17 and FIG. 18 in an enlarged manner.

FIG. 20 is a view illustrating how the object moves on the palm of the robot hand by the moving mechanism shown in FIG. 17 and FIG. 18 .

FIG. 21 is a view showing a variation of the moving mechanism used in the present embodiment.

FIG. 22 is a view showing an example of how the object moves on the palm of the robot hand by the moving mechanism of FIG. 21 .

FIG. 23 is a view showing another example of how the object moves on the palm of the robot hand by the moving mechanism of FIG. 21 .

FIG. 24A is a view showing a different example of how the object moves on the palm of the robot hand by the moving mechanism of FIG. 21 , and FIG. 24B is similarly a view showing a different example of how the object moves on the palm of the robot hand by the moving mechanism of FIG. 21 .

FIG. 25 is a view showing another variation of the moving mechanism used in the present embodiment.

FIG. 26A is a lateral view showing a different variation of the moving mechanism used in the present embodiment, and FIG. 26B is similarly a plan view showing a different variation of the moving mechanism used in the present embodiment.

FIG. 27 is a perspective view showing another kind of moving mechanism used in the present embodiment.

FIG. 28 is a perspective view showing a different kind of moving mechanism used in the present embodiment.

FIG. 29A is a perspective view showing a structure of a polymer actuator used in the present embodiment, and FIG. 29B is a perspective view showing operation of the polymer actuator.

FIG. 30 is a perspective view showing expanding and contracting drive elements formed by rolling the polymer actuator shown in FIG. 29A into the shape of a rectangular bar.

FIG. 31 is a perspective view showing yet another kind of moving mechanism used in the present embodiment.

FIG. 32 is a view illustrating a grasping operation of the object by a conventional robot hand.

Below follows a detailed description of an embodiment of the present invention with reference to the drawings.

FIG. 1 is a lateral view showing an embodiment of a robot hand according to the present invention, FIG. 2 is a plan view showing the robot hand according to the present embodiment shown from the palm side, and FIG. 3 is a rear view showing the robot hand according to the present embodiment shown from the back of the hand side.

In the robot hand 10 , a main base 101 corresponds to the palm or the back of the hand, a thumb sub base 102 is pivotally supported on the main base 101 such that it rotates parallel to the palm, and a thumb mechanism AA is supported by the thumb sub base 102 . An index finger sub base 103 is pivotally supported on the main base 101 such that it rotates parallel to the palm of the hand, and an index finger mechanism BB is supported on the index finger sub base 103 . Further, a middle finger mechanism CC, a ring finger mechanism DD, and a little finger mechanism EE are directly supported at the main base 101 .

A thumb mechanism AA is described next. A motor A 11 and a direct-acting rotational transformer A 12 are mounted on the main base 101 , and rotation of an output shaft of the motor A 11 operates the direct-acting rotational transformer A 12 . The direct-acting rotational transformer A 12 rotates the thumb sub base 102 as shown in FIG. 4 parallel to the palm of the hand.

Specifically, the direct-acting rotational transformer A 12 is made up of a yoke A 32 , a screw A 33 , gears A 34 and A 35 , a direct-acting unit A 36 , and so on, as shown in FIG. 5 . The direct-acting rotational transformer A 12 transmits the rotation of the output shaft on the motor A 11 via the gears A 34 and A 35 to the screw A 33 , thereby rotating the screw A 33 . The thumb sub base 102 , which is connected to the yoke A 32 , is rotated by moving the directing-acting portion A 36 , which is screwed onto the screw A 33 , in a rectilinear fashion along the screw A 33 , thereby moving the yoke A 32 , which engages the direct-acting unit A 36 .

FIG. 6 is a figure showing a bending and extending operation of the thumb in the robot hand according to the present embodiment. Pulleys and wires which are shown in FIG. 7 are omitted from FIG. 6 .

As shown in FIG. 6 , three motors A 13 , A 14 , and A 15 are mounted on the thumb sub base 102 , and the thumb mechanism AA is bent and extended by rotating joints a 2 , a 3 , and a 4 by transmitting to joints a 2 , a 3 , and a 4 of the thumb mechanism AA the rotation of the output shafts of the motors A 13 , A 14 , and A 15 via their respective rotation transmission mechanisms.

FIG. 7 is a view showing a partial cross-section of the motors A 13 , A 14 , and A 15 on the thumb sub base 102 and the thumb mechanism AA.

The thumb mechanism AA is provided with finger barrel portions A 21 and A 22 and finger tip portion A 23 which are linked by the joints a 2 , a 3 , and a 4 (see FIG. 6 ).

A shaft A 25 , which corresponds to the joint a 2 , is rotatably supported on the thumb sub base 102 . The shaft A 25 supports in a fixed manner a driven pulley A 41 which rotates together with the shaft A 25 , and rotatably supports idler pulleys A 42 and A 43 with respect to the shaft A 25 and the driven pulley A 41 . Link portion A 44 on the finger barrel portion A 21 is connected in a fixed manner to the driven pulley A 41 .

When the output shaft of the motor A 13 rotates, a motor pulley A 51 rotates, and the rotation of the motor pulley A 51 is transmitted to the driven pulley A 41 via the wire A 52 . The driven pulley A 41 thereby rotates together with the shaft A 25 and the link portion A 44 , and the finger barrel portion A 21 rotates around the joint a 2 .

A shaft A 26 , which corresponds to the joint a 3 , is supported at the extremity of the finger barrel portion A 21 . The shaft A 26 supports in a fixed manner a driven pulley A 45 which rotates together with the shaft A 26 , and rotatably supports idler pulley A 46 with respect to the shaft A 26 and the driven pulley A 45 . Link portion A 47 on the finger barrel portion A 22 is connected in a fixed manner to the driven pulley A 45 .

When the output shaft of the motor A 14 rotates, a motor pulley A 53 rotates, the rotation of the motor pulley A 53 is transmitted to the idler pulley A 42 and the driven pulley A 45 via a wire A 54 , the idler pulley A 42 idles, the driven pulley A 45 rotates together with the shaft A 26 and the link portion A 47 , and the finger barrel portion A 22 rotates around the joint a 3 .

Further, a shaft A 27 , which corresponds to the joint a 4 , is supported at the extremity of the finger barrel portion A 22 . This shaft A 27 supports in a fixed manner a driven pulley A 48 which rotates together with the shaft A 27 . Link portion A 49 on the finger tip portion A 23 is connected in a fixed manner to the driven pulley A 48 .

When the output shaft of the motor A 15 rotates, a motor pulley A 55 rotates, the rotation of the motor pulley A 55 is transmitted to the idler pulley A 43 , the idler pulley A 46 , and the driven pulley A 48 via a wire A 56 , the idler pulleys A 43 and A 46 idles, the driven pulley A 48 rotates together with the shaft A 27 and the link portion A 49 , and the finger tip portion A 23 rotates around the joint a 4 .

Accordingly, the thumb mechanism AA individually rotates the four joints a 1 through a 4 by the four motors A 11 and A 13 through A 15 , and has a degree of freedom of 4 .

An index finger mechanism BB is described next. A motor B 11 and a direct-acting rotational transformer B 12 are mounted on the main base 101 , and rotation of an output shaft of the motor B 11 operates the direct-acting rotational transformer B 12 . The direct-acting rotational transformer B 12 rotates the index finger sub base 103 as shown in FIG. 8 parallel to the palm of the hand.

Specifically, the direct-acting rotational transformer B 12 is made up of a screw B 33 , a yoke B 32 , a direct-acting unit B 36 , and so on, as shown in FIG. 9 . The direct-acting rotational transformer B 12 rotates the screw B 33 by transmitting the rotation of an output shaft of the motor B 11 to the screw B 33 . The index finger sub base 103 , which is connected to the yoke B 32 , is rotated by moving the direct-acting unit B 36 , which is screwed onto the screw B 33 , in a rectilinear fashion along the screw B 33 , thereby moving the yoke B 32 , which engages the direct-acting unit B 36 .

FIG. 10 is a figure showing a bending and extending operation of an index finger in the robot hand according to the present embodiment.

Pulleys and wires which are shown in FIG. 11 are omitted from FIG. 10 .

As shown in FIG. 10 , three motors B 13 , B 14 , and B 15 are mounted on the index finger sub base 103 , and the index finger mechanism BB is bent and extended by rotating joints b 2 , b 3 , and b 4 on the index finger mechanism BB by transmitting to joints b 2 , b 3 , and b 4 of the index finger mechanism BB the rotation of the output shafts of the motors B 13 , B 14 , and B 15 via their respective rotation transmission mechanisms.

FIG. 11 is a view showing a partial cross-section of the motors B 13 , B 14 , and B 15 on the index finger sub base 103 and the index finger mechanism BB.

The index finger mechanism BB is provided with finger barrel portions B 21 and B 22 and a finger tip portion B 23 , which are linked by the joints b 2 , b 3 , and b 4 (see FIG. 10 ).

A shaft B 25 , which corresponds to the joint b 2 , is rotatably supported on the index finger sub base 103 . The shaft B 25 supports in a fixed manner a driven pulley B 41 which rotates together with the shaft B 25 , and rotatably supports idler pulleys B 42 and B 43 with respect to the shaft B 25 and the driven pulley B 41 . Link portion B 44 on the finger barrel portion B 21 is connected in a fixed manner to the driven pulley B 41 .

When the output shaft of the motor B 13 rotates, a motor pulley B 51 rotates, the rotation of the motor pulley B 51 is transmitted to the idler pulley B 40 and the driven pulley B 41 via a wire B 52 , the idler pulley B 40 idles, the driven pulley B 41 rotates together with the shaft B 25 and the link portion B 44 , and the finger barrel portion B 21 rotates around the joint b 2 .

A shaft B 26 , which corresponds to the joint b 3 , is supported at the extremity of the finger barrel portion B 21 . The shaft B 26 supports in a fixed manner the driven pulley B 45 which rotates together with the shaft B 26 , and rotatably supports an idler pulley B 46 with respect to the shaft B 26 and the driven pulley B 45 . Link portion B 47 on the finger barrel portion B 22 is connected in a fixed manner to the driven pulley B 45 .

When the output shaft of the motor B 14 rotates, a motor pulley B 53 rotates, the rotation of the motor pulley B 53 is transmitted to the idler pulley B 40 , the idler pulley B 42 , and the driven pulley B 45 via a wire B 54 , the idler pulleys B 40 and B 42 idle, the driven pulley B 45 rotates together with the shaft B 26 and the link portion B 47 , and the finger barrel portion B 22 rotates around the joint b 3 .

Further, a shaft B 27 , which corresponds to the joint b 4 , is supported at the extremity of the finger barrel portion B 22 . This shaft B 27 supports in a fixed manner a driven pulley B 48 which rotates together with the shaft B 27 . Link portion B 49 on the finger tip portion B 23 is connected in a fixed manner to the driven pully B 48 .

When the output shaft of the motor B 15 rotates, a motor pulley B 55 rotates, the rotation of the motor pulley B 55 is transmitted to the idler pulley B 43 , the idler pulley B 46 , and the driven pulley B 48 via the wire B 56 , the idler pulleys B 40 , B 43 , and B 46 idle, the driven pulley B 48 rotates together with the shaft B 27 and the link portion B 49 , and the finger tip portion B 23 rotates around the joint b 4 .

Accordingly, like the thumb mechanism AA, the index finger mechanism BB individually rotates the four joints b 1 through b 4 by the four motors B 1 and B 13 through B 15 , and has a degree of freedom of 4.

A middle finger mechanism CC is described next. FIG. 12 is a figure showing a bending and extending operation of the middle finger mechanism in the robot hand according to the present embodiment. Pulleys and wires which are shown in FIG. 13 are omitted from FIG. 12 .

Two motors C 1 and C 12 are mounted on the main base 101 , as shown in FIG. 12 , rotation of output shafts of the motors C 11 and C 12 is transmitted to joints c 1 and c 2 of the a middle finger mechanism CC via their respective rotation transmission mechanisms, thereby rotating the joints c 1 and c 2 , the rotation of the joint c 2 further being transmitted to a joint c 3 via a rotation transmission mechanism, thereby drivenly rotating the joint c 3 and bending and extending a middle finger C.

FIG. 13 is a view showing a partial cross-section of the motors C 11 and C 12 on the main base 101 and the middle finger mechanism CC.

The middle finger mechanism CC is provided with finger barrel portions C 21 and C 22 and a finger tip portion C 23 which are linked by the joints c 1 and c 2 .

A shaft C 24 , which corresponds to the joint c 1 , is rotatably supported on the main base 101 . The shaft C 24 supports in a fixed manner the driven pulley C 31 which rotates together with the shaft C 24 , and rotatably supports an idler pulley C 32 with respect to the shaft C 24 and the driven pulley C 31 . Link portion C 33 on the finger barrel portion C 21 is connected in a fixed manner to the driven pulley C 31 .

When the output shaft of the motor C 11 rotates, a motor pulley C 41 rotates, the rotation of the motor pulley C 41 is transmitted to the driven pulley C 31 via a wire C 42 , the driven pulley C 31 rotates together with the shaft C 24 and the link portion C 33 , and the finger barrel portion C 21 rotates around the joint c 1 .

A shaft C 25 , which corresponds to the joint c 2 , is supported at the extremity of the finger barrel portion C 21 . This shaft C 25 supports in a fixed manner a driven pulley C 34 , which rotates together with the shaft C 25 , and a driving force transmission pulley C 35 . Link portion C 36 on the finger barrel portion C 22 is connected in a fixed manner to the driven pulley C 34 .

When the output shaft of the motor C 12 rotates, a motor pulley C 43 rotates, the rotation of the motor pulley C 43 is transmitted to the idler pulley C 32 and the driven pulley C 34 via a wire C 44 , the idler pulley C 32 idles, the driven pulley C 34 rotates together with the shaft C 25 and the link portion C 36 , and the finger barrel portion C 22 rotates around the joint c 2 .

Further, a shaft C 26 , which corresponds to the joint c 3 , is supported at the extremity of the finger barrel portion C 22 . A driven pulley C 37 , which rotates together with the shaft C 26 , is connected in a fixed manner to this shaft C 26 . Link portion C 38 on the finger tip portion C 23 is connected in a fixed manner to the driven pulley portion C 37 .

When the driving force transmission pulley C 35 rotates together with the driven pulley C 34 of the joint c 2 , the rotation of the driving force transmission pulley C 35 is transmitted to the driven pulley C 37 via the wire C 45 . The driven pulley C 37 rotates together with the shaft C 26 and the link portion C 38 , and the finger tip portion C 23 rotates around the joint c 2 . In other words, the joint c 3 drivenly rotates with respect to the joint c 2 .

Accordingly, the middle finger C individually rotates the two joints c 1 and c 2 by the two motors C 11 and C 12 , and has a degree of freedom of 2.

A ring finger mechanism DD and a little finger mechanism EE are described next. FIG. 14 is a figure showing a bending and extending operation of the ring finger mechanism and the little finger mechanism in the robot hand according to the present embodiment. Pulleys and wires which are shown in FIG. 15 are omitted from FIG. 14 .

A motor DE 11 is mounted on the main base 101 as shown in FIG. 14 , rotation of an output shaft of the motor DE 11 is transmitted to joints d 1 and d 2 of the ring finger mechanism DD and joints e 1 and e 2 of the little finger mechanism EE via their respective rotation transmission mechanisms, thereby rotating the joints d 1 and d 2 of the ring finger mechanism DD and the joints e 1 and e 2 of the little finger mechanism EE and bending and extending the ring finger mechanism DD and the little finger mechanism EE.

FIG. 15 is a cross-section view showing a partial cut-away of the area around the motor DE 11 on the main base 101 .

A shaft DE 24 , which corresponds to the joints d 1 and e 2 (see FIG. 14 ), is rotatably supported on the main base 101 . A gear DE 31 is supported in a fixed manner on the shaft DE 24 , and a pair of pulleys D 32 and E 32 are rotatably passed therethrough. These pulleys D 32 and E 32 are fixed to respective supporting portions 101 c. A gear box DE 32 intermeshes a gear DE 33 , bevel gears DE 34 , a gear DE 35 , and so on. By connecting the gear DE 35 to the output shaft of the motor DE 11 , the rotation of the output shaft is transmitted to the gear DE 33 via the gear DE 35 and the bevel gears DE 34 , and the gear DE 31 , which intermeshes with the gear DE 33 , thereby rotates.

FIG. 16 is a view showing a partial cross-section of the shaft DE 24 , the ring finger mechanism DD and the little finger mechanism EE on the main base 101 .

The ring finger mechanism DD is provided with finger barrel portions D 21 and D 22 and a finger tip portion D 23 , which are linked by the joints d 1 and d 2 (see FIG. 14 ). The little finger mechanism EE is provided with finger barrel portions E 21 and E 22 and a finger tip portion E 23 , which are linked by the joints e 1 and e 2 .

Link portions D 33 and E 33 of the finger barrel portions D 21 and E 21 are connected in a fixed manner to the gear DE 31 of the shaft DE 24 .

A shaft D 25 , which corresponds to the joint d 2 , is supported at the extremity of the finger barrel portion D 21 . A driven pulley D 34 , which rotates together with the shaft D 25 , is connected in a fixed manner to this shaft C 25 . Link portion D 35 on the finger barrel portion D 22 is connected in a fixed manner to the driven pulley D 34 .

Similarly, a shaft E 25 , which corresponds to the joint e 2 , is supported at the extremity of the finger barrel portion E 21 . A driven pulley E 34 , which rotates together with the shaft E 25 , is connected in a fixed manner to this shaft E 25 . Link portion E 35 of the finger barrel portion E 22 is connected in a fixed manner to the driven pulley E 34 .

When the output shaft of the motor DE 11 turns, the rotation of the output shaft is transmitted to the gear DE 31 via the gearbox DE 32 , the gear DE 31 turns, and the finger barrel portion D 21 also rotates around the joint d 1 .

Although the wire D 36 revolves around the shaft DE 24 as the finger barrel portion D 21 rotates around the joint d 1 , the pulley D 32 which is fixed to the supporting portions 101 c does not rotates, so the wire D 36 either is wound by the pulley D 32 or is released and the driven pulley D 34 rotates together with the shaft D 25 and the linking portion D 35 , whereby the finger barrel portion D 22 rotates around the joint d 2 . Accordingly, the finger barrel portions D 21 and D 22 rotate simultaneously. As regards the finger barrel portions E 21 and E 22 and the finger tip portion E 23 , similarly to the finger barrel portions D 21 and D 22 and the finger tip portion D 23 , wires E 36 stretch across the pulley E 32 on the shaft DE 24 and the driven pulley E 34 on the shaft E 25 , so when the output shaft of the motor DE 11 rotates, the finger barrel portion E 21 rotates around the joint e 1 , and the finger barrel portion E 22 rotates around the joint e 2 .

Accordingly, the ring finger mechanism DD and the little finger mechanism EE have a degree of freedom of 1, as the joints d 1 and d 2 in the ring finger mechanism DD and the joints e 1 and e 2 in the little finger mechanism EE are rotated by the one motor DE 11 .

With this type of the robot hand 10 , the thumb mechanism AA and the index finger mechanism BB have a degree of freedom of 4, the middle finger mechanism CC has a degree of freedom of 2, and the ring finger mechanism DD and the little finger mechanism EE have a degree of freedom of 1, so the degree of freedom of the robot hand 10 itself is 11.

Moreover, the plurality of motors which drive the finger mechanisms AA though EE are connected to a control circuit (not shown) via respective lines (not shown), and rotate by being controlled by this control circuit. The joints thereby rotate and the finger mechanisms AA through EE bend and extend.

Each joint in the finger mechanisms AA through EE is provided with a potentiometer for detecting the rotation angle of the joint. Each potentiometer is connected to the above-mentioned control circuit via the lines. The control circuit rotates each joint in the finger mechanisms AA through EE such that the rotation angle of the joint detected by the potentiometer achieves a target value, thereby operating the finger mechanisms AA through EE in a variety of manners.

The finger tip portion A 23 , the finger tip portion B 23 , the finger tip portion C 23 , the finger tip portion D 23 , the finger tip portion E 23 , and so on, of the finger mechanisms AA through EE are each provided with force sensors for detecting forces acting on the various finger tip portions as part of a gripping operation of an object by the robot hand 10 . Each force sensor is connected to the above-mentioned control circuit via the lines. The control circuit controls the gripping force and so on of the robot hand 10 by controlling the driving force of each motor, determining the gripping state of the object based on the forces detected by the force sensors. The force sensors may be provided to the finger barrel portions or other portions as well as to the finger tip portions.

Further, drive mechanisms for the fingers of the robot hand 10 may not be limited to combinations of pulleys and wires, but rather combinations of gears and many more combinations have already been proposed, which may be appropriately used as drive mechanisms.

Incidentally, the robot hand 10 according to the present embodiment has a degree of freedom of 11, but is nevertheless unable to perfectly imitate the complex movement of a human hand. Moving an object on the palm of the robot hand 10 with the robot hand 10 gripping the object is therefore an operation of great difficulty.

Accordingly, the palm of the robot hand 10 is provided with a moving mechanism 61 in the present embodiment as shown in FIG. 17 and FIG. 18 . The moving mechanism 61 is represented by a dashed double dotted line in FIG. 1 and FIG. 2 .

The moving mechanism 61 is a so-called belt conveyor, and, as shown expanded in FIG. 19 , a driving roller 62 and a driven roller 63 are arranged separated, an endless belt 64 is supported stretched across the driving roller 62 and the driven roller 63 , the driving roller 62 is rotated by the motor 65 , thereby rotatedly moving the endless belt 64 .

Transmission of the rotational force from the motor 65 to the driving roller 62 is done via a gear 66 on the output shaft of the motor 65 and a gear 67 on the shaft of the driving roller 62 , which mutually intermesh. Moreover, the motor 65 is connected to the control circuit (not shown) via a plurality of lines (not shown), and rotates by being controlled by this control circuit.

The motor 65 , a shaft bearing (not shown) of the driving roller 62 , and a shaft bearing (not shown) of the driven roller 63 may be directly affixed to an appropriate location on the palm of the robot hand 10 , and may be affixed to a frame (not shown) which is affixed to the palm of the robot hand 10 .

Moreover, the motor 65 is exposed to the exterior, but a cover for protecting the motor 65 may be provided. Providing the cover makes the robot hand 10 thicker, so the cover may be omitted in order to ensure thinness.

On the robot hand 10 of this configuration, the moving mechanism 61 may be provided to the palm of the robot hand 10 , making it possible to move an object P by the moving mechanism 61 in the direction of an arrow G with the robot hand 10 gripping the object P as shown in FIG. 20 . The object P can thereby be manipulated in a more complex manner compared to a robot hand without the moving mechanism 61 . The moving mechanism 61 which is a belt conveyor need simply be added on, so technical feasibility is very high, and control is easy.

According to the present embodiment, the moving direction of the moving mechanism 61 is set as a vertical direction along the palm, but the moving direction may be set to cross the palm horizontally. In this case, the object P is moved in a horizontal direction by the moving mechanism 61 on the palm of the robot hand 10 . Alternately, the moving direction of the moving mechanism 61 may be set as a diagonal direction.

Two moving mechanisms 61 a and 61 b shown in FIG. 21 may also be provided to the palm. The moving mechanisms 61 a and 61 b are belt conveyors like the moving mechanism 61 . The moving direction by the moving mechanisms 61 a and 61 b is, however, set to a direction across the palm horizontally.

In the case in which these two moving mechanisms 61 a and 61 b are provided, manipulation of objects by the robot hand 10 becomes even more diverse. For example, if the moving direction and the moving speed by the moving mechanisms 61 a and 61 b match as shown in FIG. 22 , the object P can be moved in the direction of an arrow H by the moving mechanisms 61 a and 61 b , similarly to the single moving mechanism 61 .

If a moving direction I by the moving mechanisms 61 a and 61 b is matched while a moving speed by the moving mechanism 61 a is made faster than a moving speed by the moving mechanism 61 b , as shown in FIG. 23 , then object P can be moved in the direction of the arrow I while rotating in the direction of an arrow J on the palm, enabling tilting of the object P. Needless to say, adjusting moving speeds by the moving mechanisms 61 a and 61 b and reversing the moving direction by the moving mechanisms 61 a and 61 b makes it possible to change the transporting speed, the rotating speed, and so on of the object P.

Alternately, if the moving direction of the moving mechanism 61 a and the moving direction of the moving mechanism 61 b are made opposite, the object P can be rotated on the palm almost without changing the position on the palm of the object P, thereby tilting the object P.

For example, the gripping power of the robot hand 10 can be reduced to the point where the object P does not fall, with the robot hand 10 gripping the object P which is long, as shown in FIG. 24A . A gripping power sufficient for gently pushing the object against the moving mechanisms 61 a and 61 b is, however, maintained. Thereafter, the moving directions of the moving mechanisms 61 a and 61 b are matched, the moving speeds by the moving mechanisms 61 a and 61 b are made different, the object P is moved on the palm while being tilted, the object P is moved in the direction of an arrow K as shown in FIG. 24B , the extremity of the object P is moved to the palm of the hand, and the moving mechanisms 61 a and 61 b are stopped. With this, the gripping location of the object P on the palm of the robot hand 10 can be moved.

This kind of manipulation of the object P is required, for example, when operating a remote control device for an electrical appliance with the robot hand 10 . The remote control device has an oblong shape and buttons arranged over almost all of its top side. Therefore, in order to press all the buttons from one side to the other of the remote control device, the remote control device must be moved and the gripping location changed.

Aside from the above, in order to change to a more stable grip of the oblong object P, the object P need only be moved and rotated by the moving mechanisms 61 a and 61 b.

The moving direction by the moving mechanisms 61 a and 61 b may be set to a vertical direction as shown in FIG. 25 , and the object P moved in the vertical direction along the palm of the robot hand 10 . Alternately, the moving direction of the moving mechanisms 61 a and 61 b may be set as a diagonal direction.

Further, as shown in FIG. 26A and FIG. 26B , one moving mechanism 61 a may be arranged on the palm of the robot hand 10 , the other moving mechanism 61 b may be arranged near the base of the thumb finger mechanism AA of the robot hand 10 , and the moving surfaces of the moving mechanisms 61 a and 61 b may be made vertical. In this case, the touching of the moving mechanisms 61 a and 61 b on the respective vertical surfaces of the object increases the touching area between the object and the moving mechanisms 61 a and 61 b. If the object has a complex shape, touching between the object and the moving mechanisms 61 a and 61 b can be ensured, thereby ensuring stable moving of the object by the moving mechanisms 61 a and 61 b.

Further, the number of the moving mechanisms may be increased and the size, shape, and arranged location of each moving mechanism may be changed, thereby making possible more complex manipulation of objects of different shapes and sizes.

Moreover, in the present embodiment, a belt conveyor is used as a moving mechanism, but other types of moving mechanisms may be applied. For example, there is an actuator 70 as shown in FIG. 27 . The actuator 70 is formed by lining up a plurality of pressure chambers 72 on a plate-shaped elastic member 71 , tubes 73 are connected to the pressure chambers 72 , and by feeding air to the pressure chambers 72 and releasing air from the pressure chambers 72 via the tubes 73 , the pressure chambers 72 are selectively sequentially expanded and contracted, thereby deforming the elastic member 71 , forming progressive waves on a rough surface 71 a of the elastic member 71 , and thereby transporting objects on the rough surface 71 a of the elastic member 71 in a progressing direction and a reverse direction of the progressive waves (see JP H9-79213A, etc.).

This kind of actuator 70 is ideal for mounting on the palm of the robot hand, as it can be made very thinly. Since the material of the actuator 70 is elastic, even if the surface on which it is installed is curved, the actuator 70 can be mounted onto the curved surface without gaps.

Further, as a moving mechanism, an actuator 80 as shown in FIG. 28 can be applied. With this actuator 80 , a flexible substrate 84 is overlaid and affixed to an actuator substrate 81 , a plurality of expanding and contracting drive elements 82 is arranged in a line on the flexible substrate 84 , a sheet-shaped elastic member 83 is mounted and engaged on a top end of the each expanding and contracting drive element 82 , and control drive portions 85 are connected to the expanding and contracting drive elements 82 via the flexible substrate 84 . The control drive portion 85 sequentially applies voltage to the expanding and contracting drive elements 82 via the flexible substrate 84 , sequentially expanding and contracting the expanding and contracting drive elements 82 in a direction Z, thereby deforming the elastic member 83 such that it undulates, and forming on the surface of the elastic member 83 progressive waves in the direction X, which is the progressing direction. When an object is placed on the elastic member 83 , the object is transported in a direction opposite the direction X by the progressive waves on the elastic member 83 .

The expanding and contracting drive elements 82 is formed, as shown in FIG. 30 , by rolling a polymer actuator in which a sheet-shaped polymer material 91 is sandwiched between a pair of electrodes 92 and 93 as shown in FIG. 29A into a rectangular bar. The polymer material 91 is also known as a dielectric elastomer, an electrostrictive polymer, and so on, and is formed by spin coating, dip coating, casting, or spraying. The electrodes 92 and 93 have flexibility and are formed through a manufacturing method similar to that of the polymer material 91 .

When voltage is applied to the electrodes 92 and 93 , an electrostatic force arises between the electrodes 92 and 93 , and this electrostatic force acts to broaden the polymer material 91 as shown in FIG. 29B , and the polymer material 91 and the electrodes 92 and 93 extend, the expanding and contracting drive elements thereby lengthening.

When the application of the voltage between the electrodes 92 and 93 stops, the electrostatic force between the electrodes 92 and 93 disappears, the polymer material 91 and the electrodes 92 and 93 return to their original state as shown in FIG. 29A , and the length of the expanding and contracting drive elements returns to as it was.

This type of polymer actuator is described in detail on pp. 32–38 of the January, 2001 issue of Erekutoronikusu Jisso Gijutsu published by Gicho Publishing & Advertising Co., Ltd. as well as on pp. 836–837 of vol. 287 of the April (February), 2000 issue of Science published by the Saiensu-Sha Co., Ltd.

This kind of actuator 80 has a simple configuration and can be made thin in its entirety, and can thereby be mounted even in small spaces. The speed of response of the polymer actuator is fast, so the speed of the progressive waves can be made faster, and the moving speed of objects can be increased.

Further, if the expanding and contracting drive elements 72 are arranged in rows or in a variety of arrangement patterns and the expansion and contraction order of the expanding and contracting drive elements 72 is set appropriately, the object can be moved vertically and horizontally and rotated.

There exist expanding and contracting drive elements in which take advantage of the fact that when electrodes are provided to the polymer material and voltage is applied, it intakes ions and expands, and these may be used. Alternately, as long as an actuator can be controlled electrically and has similar properties to those of the polymer actuator, any kind of drive elements may be used. There also exist expanding and contracting drive elements which create ultrasonic waves on the surface of the elastic member, thereby transporting objects.

Further, a plurality of rollers 95 arranged on the palm of the robot hand 10 as shown in FIG. 31 may be used as the moving mechanism. The rollers 95 are rotatedly driven by a motor (not shown), thereby moving the object on the palm by the rollers 95 . Not all of the rollers 95 need to rotatedly drive, and instead some of the rollers 95 may be driven.

Note that the present invention is no limited to the above embodiment, and may be varied in many ways. For example, the various types of moving mechanisms described above may be used in combination. The moving mechanisms may be provided to the cushions of the fingers and so on, and not just the palm.

In this way, the present invention may include numerous other embodiments without departing from its spirit or main characteristics. Therefore, the embodiments described are nothing more than simple examples, and must not be interpreted in a limiting manner. The scope of the invention is indicated by the appended claims rather than by the foregoing description. All variations and modifications falling within the equivalency range of the appended claims are intended to be embraced therein.