JP2003175484A - Man type robot arm - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a man type robot arm having 7 degrees of freedom of which the air cylinder is built in compactly inside an arm. <P>SOLUTION: In this robot arm having 7 degrees of flexibility constituted of a humeral joint 1, a brachial joint 2, an elbow joint 3, a forearm joint 4 and a wrist joint 5, and driven by air pressure, an air cylinder as joint driving actuator is used in common as an endoskeleton structural member for the brachial joint and the forearm joint. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a new mechanism in which an air cylinder is compactly built in an arm.
The present invention relates to a humanoid robot arm having a degree of freedom.

[0002]

2. Description of the Related Art Pneumatic pressure is easier and safer to handle than hydraulic pressure, and is therefore useful as a power source for a robot arm that cooperates with humans. However, since the air pressure is much lower than the oil pressure, an air cylinder having a large diameter and a large stroke is required to obtain a large output. However, it is difficult to incorporate such a large air cylinder in a humanoid robot arm whose size and range of motion are comparable to those of a human, and even if the large air cylinder is housed in an arm, it does not work. By occupying most of the inner space, there is a problem that bending and stretching movements of the arm and storage of electrical components are likely to be hindered.

[0003]

Therefore, in a conventional robot arm, a drive mechanism including an air cylinder is used.
A method has been used in which power is transmitted to the hand by means of a wire pull mechanism, which is provided outside the system. This method requires a large occupied space for the drive mechanism, increases the weight of the mechanism as a whole, and inevitably reduces movement accuracy and efficiency due to wire elongation and friction.

Therefore, in the present invention, the arrangement of actuators (air cylinders) for driving joints driven by air pressure and the mechanism for transmitting power to the joints to be driven are examined, and the air cylinders are compactly built in the arms. By providing a humanoid robot arm with 7 degrees of freedom,
The purpose is to solve the above problems.

According to the present invention, the air cylinder itself is made to have high strength, and the air cylinders are incorporated in the axes of the arm and forearm joints of the arm, and most of the structural members of the arm and forearm joints are made of the air cylinder. Adopts an internal skeleton structure that is also used. The compact feed screw mechanism that converts the linear motion of the air cylinder into the rotational motion around the axis is adopted, and only the mechanism corresponding to the rod-shaped endoskeleton allows the torsional movement of ± 90 degrees in the upper arm segment and the forearm segment. Realize the area. A link mechanism that efficiently transfers the output of the air cylinders to the joints is used for rotational movements of the wrist, elbow, and shoulder joints other than the twisting of the arm joints. Together, it realizes a large range of motion of those joints.

[0006]

Therefore, the solution adopted by the present invention is composed of a shoulder joint, an upper arm joint, an elbow joint, a forearm joint, and a wrist joint, and is driven by air pressure. In a humanoid robot arm having a degree of freedom, an air cylinder as an actuator for joint drive is commonly used as an endoskeletal structural member of an upper arm joint and a forearm joint. Further, a joint that realizes a twisting motion around the axis of each of the upper arm node and the forearm node is disposed at the center of the node and is driven by the expansion and contraction motion of the rod of the air cylinder that also serves as a part of the structural member of the node. A humanoid robot arm having a built-in screw mechanism. Further, the feed screw mechanism includes a cam member having a spiral cam groove on the inner wall of the cylindrical space, and the cam member is inserted into the cylindrical space of the cam member and fitted into the cam groove, and at the rod tip of the air cylinder. A humanoid robot arm characterized by being configured with a cam follower attached. Further, the rod of the air cylinder is configured to expand and contract in a state in which the rotation preventing guide that is housed in the cylindrical space of the cam member prevents the rotational movement around the axis of the air cylinder. It is a humanoid robot arm. Further, each of the upper arm joint and the forearm joint is composed of two joints connected by sandwiching the joint for torsional movement, the air cylinder is arranged at one joint, and the cam member is arranged at the other joint, A humanoid robot arm characterized in that an air cylinder is actuated to expand and contract a rod to rotate a cam member via a cam follower, and as a result, each of the brachial joint and the forearm joint is twisted about an axis. In addition, the bending motion in the shoulder joint and the elbow joint constructs a four-bar linkage mechanism between a driving-side node having a driving air cylinder and a driven-side node, through which a rod of the driving air cylinder moves. The humanoid robot arm is characterized in that the range of motion is expanded by transmitting the stretching motion. A part of the air cylinder also serves as a balance weight, which is a humanoid robot arm. In addition, the wrist joint makes a rotational movement with two degrees of freedom, and the two rotational axes and the three axes of the forearm joints are in one
A girder-shaped member that has a space for wiring and piping in the center is provided between the knotted joint and the forearm knot, and drives the rotational movement between the knotted joint and the girder-shaped member. The humanoid robot arm is characterized by being configured by an air cylinder that operates and a pneumatic cylinder that drives rotational movement between the cross beam member and the forearm joint.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of a humanoid robot hand as an embodiment according to the present invention will be described below with reference to the drawings.

FIG. 1 is a view showing the entire right arm of a humanoid robot arm, and FIG. 2 is a humanoid robot having a humanoid robot arm connected to a humanoid robot body and a humanoid robot hand and having both arms and both hands. FIG. 3 is a diagram showing the overall image of FIG. 3, FIG. 3 is a diagram showing the arrangement and nominal names of seven joints in the humanoid robot arm, and FIG. 4 is a diagram showing the range of motion of each joint of the humanoid robot arm. Hereinafter, the overall configuration of the humanoid robot arm and its operation will be described, and then the detailed configuration of each member will be described with reference to the detailed diagrams corresponding to the respective components.

In FIG. 1, a humanoid robot arm is connected to a shoulder joint 1, an upper arm joint 2 connected to the shoulder joint 1, an elbow joint 3 connected to the upper arm joint 2, and an elbow joint 3. The robot arm is composed of a forearm joint 4 and a wrist joint 5 connected to the forearm joint 4, and the robot arm is connected to a torso D of a humanoid robot and a humanoid robot hand H as shown in FIG. Configured as a humanoid robot with arms and hands. The humanoid robot arm has a structure in which, in the shoulder joint 1, as shown in FIG. 3, the upper arm joint 2 can be swung up, down, left and right by the joints J ₁ and J _{2 in the} figure. _The upper arm joint 2 can be rotated about its axis by ₃ .

The humanoid robot arm has a structure in which, in the elbow joint 3, the forearm joint 4 can be swung up and down in the figure with respect to the upper arm joint 2 by a joint J ₄ , as shown in FIG. Within the joint 4, the joint J ₅ allows the forearm joint 4 to rotate about its axis. Further, the humanoid robot arm is configured such that the joint J ₆ can swing up and down in the figure at the wrist joint 5, and the joint J ₇ can swing the humanoid robot hand left and right. As shown in FIG. 1, one end of two air cylinders A1 and A2 for operating the upper arm joint 2 vertically and horizontally centering on the joint J ₁ and the joint J ₂ from the shoulder to the rear of the humanoid robot arm. Side is support member 2
It is arranged in a state of being supported by 0.

The upper arm joint 2 and the forearm joint 4 are respectively connected to the joint J _{3 in} the upper arm joint 2 and the forearm joint 4, respectively.
And joint J ₅ air cylinder A3, A5 is built for rotating about an axis centered on, by actuating the respective air cylinders A3, A5, upper arm section 2 or forearm clause 4 joint J _3, joint J
It can be rotated around the axis in ₅ parts.

All air cylinders used in this robot arm must be capable of producing the same output in any direction during the reciprocating motion of the rod, and therefore the double-acting type is adopted. In addition, the sliding resistance in the reciprocating motion of the rod is as small as possible in order to enable smooth and delicate adjustment of the output and to realize a back drivability function that can move the arm by applying an external force. To adopt. FIG. 4 shows joints J ₁ , J ₂ , J ₄ , and J arranged in the shoulder joint, elbow joint, and wrist joint.
₆ and J ₇ and the movable ranges of the joints J ₃ and J ₅ assembled in the upper arm joint and the forearm joint are shown.

[0013] Next, in the above joint J _3, J ₅ of the upper arm section 2 and the forearm section 4 air cylinder A3, the internal skeletal mechanism compact to achieve a twisting motion of the axis by an air cylinder A5 will be described. Figure 5 shows forearm segment 4
FIG. 6 is a perspective view illustrating a skeleton structure in the forearm joint including the joint J ₅ for rotating the wrist-side knot forming the joint around the axis, and FIG. 6 is an exploded view illustrating the skeleton structure in the forearm joint. 7 is an exploded explanatory view of the feed screw mechanism arranged in the forearm joint, FIG. 8 is a plan view of the forearm joint and a sectional view taken along line AA in FIG. 8, and FIG. 9 is an enlarged sectional view taken along line BB in FIG. , FIG. 10 is FIG.
It is a C section enlarged view in the inside. In addition, the joint of the upper arm J ₃
Although the skeleton structure including is slightly different in the shape of the endoskeleton mechanism, the basic skeleton structure is similar to that of the forearm segment, and hence the endoskeletal mechanism of the forearm segment will be described as a representative example.

[Air cylinder A that also serves as the internal skeleton of the forearm joint
Arrangement of 5] In FIG. 6, the forearm segment 4 is divided into two segments, a shoulder segment 6 and a wrist segment 7, in order to realize a twisting motion about an axis, and these segments 6, 7 It is connected via an air cylinder A5 operating the joint J ₅ about the axis as described above. Specifically, the rod is expanded and contracted by the operation of the air cylinder A5, and the joint 7 on the wrist side can rotate around the axis at the joint J _{5 with} respect to the joint 6 on the shoulder side. 13 and a cylinder tube 16. A gear 8 is fixed to the joint 7 on the wrist side, and an encoder 9 having a gear 9a that meshes with the gear 8 is arranged on the joint 6 on the shoulder side. The rotation angle can be detected.

As shown in FIG. 6, the shoulder side joint 6 is a cylindrical outer member 10 capable of accommodating the joint J ₅ and a cylindrical cam member (FIG. 7) fitted and fixed inside the outer member 10.
11), an encoder 9 fixed to the outer member 10 and a gear 9a. Further, as shown in FIG. 7, the wrist 7 on the wrist side is a rotation prevention guide 12 fitted inside the cam member 11, and a cam follower 14 assembled in the rotation prevention guide 12 (see FIG. 7, details will be described later). ), The gear 8 attached to the rotation prevention guide 12, and the rod 13 fixed to the cam follower 14.
And a cylinder tube 16 that moves the rod 13 back and forth. The wrist side joint 7 having the above-described structure is provided with two bearings 15 as shown in FIG.
Is rotatably assembled in the outer member 10 forming the shoulder side joint 6.

The joint J ₅ is attached to one of the shoulder side joint 6 and the wrist side joint 7 described above.
The cylinder tube 16 of the air cylinder A5 for driving the cylinder is used. Although the cylinder tube 16 of the air cylinder A5 is used as a constituent element of the joint 7 on the wrist side in this example, the air cylinder A is used as a constituent element of the joint 6 on the shoulder side.
It is also possible to use 5 cylinder tubes.

The cylinder tube 16 serves as an internal skeleton of the forearm joint, and the air cylinder A5 is selected in which not only the output is sufficient but also the size and strength of the cylinder tube 16 are sufficient. The cylinder tube 16 is arranged so as to be a part of the endoskeleton of the wrist side joint. That is, from the viewpoint of reducing the moment in the shoulder joint and elbow joint necessary to support the weight of the arm mechanism, the air cylinder has a lower density (weight) than the drive mechanism for driving the joint J _5. Therefore, it is desirable to dispose the cylinder tube of the air cylinder A5 as a constituent element of the node on the wrist side and arrange the drive mechanism to the node 6 on the shoulder side.

Further, blocks 17 and 18 for closing the tube and providing an air inlet / outlet are arranged at both ends of the cylinder tube 16 of the air cylinder A5, and the shapes of the blocks 17 and 18 are devised. Then, by also serving as the connecting portion of the drive mechanism and the attaching portion of the wrist mechanism to be described later, almost all of the joints 7 on the wrist side are cylinder tubes 16.
It is integrated with. Further, a gear 8 is fixed to the wrist side joint 7 coaxially with the wrist side joint, and by disposing an encoder 9 having a gear 9a that meshes with the wrist side joint on the shoulder side joint 6, the twist angle between both joints can be increased. Is designed to be measured.

Next, a drive mechanism for rotating the joint 7 on the wrist side about the axis with respect to the joint 6 on the shoulder side by the joint J ₅ . [Driving Mechanism] The driving mechanism of the joint J ₅ is a feed screw mechanism. The feed screw mechanism is intended for driving the joint J ₅ of the above to convert the linear motion to the twisting motion of the air cylinder A5 of the rod 13, the shoulder side section in which the rod-like because the structure is simple and cylindrical It is installed in 6. That is, the cam member 11 in which the spiral cam groove 11a shown in FIG. 7 is formed is fixed in the outer member 10 forming the shoulder side node 6. This cam member 1
As shown in FIG. 7, a rotation prevention guide 12 that constitutes a wrist side node 7 is fitted in the rotation prevention guide 12, and a rod 13 of an air cylinder A5 is arranged in the rotation prevention guide 12 and is attached to the tip of the rod 13. The fixed cam follower 14 is configured to engage with the cam groove 11a of the cam member 11 through the elongated hole 12a formed in the rotation prevention guide 12 (details will be described later). With this configuration, the rod 13 having the cam follower 14 fixed thereto by the air supplied to the air cylinder A5.
When is moved linearly back and forth in the axial direction, the cylinder tube 16 forming a wrist side node rotates around the axis with the rod 13 via the cam follower by the action of the cam groove 11a of the cam member. In this way, the torsional movement between the joints is realized.

By the way, it is desirable that the air cylinder A5 used in the present robot arm is lightweight and has a small sliding resistance of the rod 13, so that a structure having such performance is easy to manufacture, that is, a cylindrical cylinder tube. Cylindrical piston 13a that fits into the cylinder 16 and the cylinder 16
(See FIG. 8) and the rod 13 fixed to the piston 13a. In this case, the rod 13 is not only linearly moved on the axis of the air cylinder A5, but also freely twisted about the axis. However, in order for the feed screw mechanism to function,
Since the cam follower fixed to the tip of the rod 13 must not make a twisting motion around the axis with respect to the wrist side node 7, the following guide mechanism is provided to prevent the twisting rotation.

In FIG. 7, a rotation preventing guide 12 having a cylindrical shape is arranged inside the cam member 11 with a slight clearance therebetween so as not to come into contact with the cam member 11. Specifically, as shown in FIG. 7, the rotation preventing guide 12 is inserted into the cam member 11 in which the spiral cam groove 11 a is formed so as not to come into contact with the cam member 11, and the rotation preventing guide 12 is attached to the end of the cylinder tube 16. The rotation prevention guide 12 is formed with a long hole 12a through which the cam follower 14 fixed to the rod 13 of the air cylinder A5 protrudes. The elongated hole 12a is formed parallel to the axial direction of the rotation prevention guide 12.

The cam follower 14 is a rotation prevention guide 1
The cam member 1 is further penetrated through the elongated hole 12a
It is configured to fit into the cam groove 11a formed in No. 1. The cam follower 14 is configured as a double cam follower having the same shaft and freely rotating in order to reduce the sliding resistance between the rotation preventing guide 12 and the cam member 11. More specifically, as shown in FIG. 9, two bearings 14a and 14b are provided on the shaft of the cam follower 14.
Is attached, and the cam follower 14 can move smoothly with respect to the rotation prevention guide 12 and the cam member 11.

With the above construction, when the air cylinder A5 is operated, the elongated hole 12a formed in the rotation preventing guide 12 serves as a linear motion guide, and the torsional rotation of the rod 13 is prevented without applying a load to the rod 13 of the air cylinder. be able to. Therefore, in order to increase the rigidity of the cylinder forming the rotation prevention guide 12 as much as possible, the space between the inner wall of the cam member 11 and the outer wall of the rod 13 is almost filled. With the above structure, high rigidity, also high efficiency small sliding resistance of the rod, the drive mechanism of the compact joint J ₅ is obtained (see FIGS. 7 to 10).

[Elbow and Shoulder Joint Drive Mechanism] A compact drive mechanism that realizes rotational movements of the elbow joint and the shoulder joint will be described. This drive mechanism is composed of shoulder joints J ₁ , J
_2, used in elbow joint J _4, although the shape of each mechanism slightly different, since there is no difference that must be changed particularly large description, the first elbow joint joint J ₄
The drive mechanism will be described as a representative.

In FIG. 11, a general mechanism for driving a joint with a direct-acting actuator, regardless of whether it is an air cylinder or a hydraulic cylinder, is a joint provided on each of two joints connected by the joint. Is a direct-acting actuator
The structure is such that the joint is rotated and the distance between both joints is increased or decreased by the output of the linear motion actuator to rotate the joint. However, in this mechanism type, in order to realize a large rotation angle, an actuator with a long expansion / contraction stroke is required, and when a certain rotation torque is generated, the rotation angle of the joint changes. On the other hand, the problem is that the generated force that the linear motion actuator should exert varies greatly. When driven by a hydraulic cylinder that can generate a very small force even if it is small, it can be incorporated by reducing the entire mechanism in a similar manner, instead of allowing the force to be generated to be large. However, if it is necessary to drive with an air cylinder that generates a small amount of force for its size, this mechanism type is inappropriate. Therefore, the following four-bar linkage mechanism is provided to convert the stroke and generated force of the air cylinder into the driving work of the elbow joint as efficiently as possible.

FIG. 12 shows the joint J of the elbow joint._FourCentered around
It is explanatory drawing of a drive mechanism for rotating the elbow joint.
The air cylinder A4, the length of the contour line when the elbow joint bends
Is arranged on the side where the
Joint P at the end on the wrist side that constitutes the upper arm joint_4,1so
Link. Joint P at the tip of the rod_4,2And before
Joint P on the arm joint_4,3Between the link L_4,2Insert
Enter and link L_4,2Connect with. Also, link L
_4,1Is a joint P with the upper arm node side at one end_4,4Connect with
The other end and the rod tip and joint P_4,2Connect with. here
And link L_4,1, L _4,2The length of the
INT P_4,3, P_4,4When the elbow joint bends
Link to L_4,2Moves around the outside of the elbow joint
(See FIG. 12). With this mechanism,
Link L is the movement of rod of A4_4,2Through the joint
The forearm is transformed to be closer to the movement in the direction of rotation
The stroke of the air cylinder A4 is transmitted to the node.
Efficiently converted into rotary motion, and the generated force is efficient
Will be converted into rotational force.

Next, the driving mechanism for the joints J ₁ and J ₂ of the shoulder joint will be briefly described. FIG. 13 is an explanatory diagram of a drive mechanism for rotating the shoulder joint about the joints J ₁ and J ₂ . This drive mechanism is similar to the drive mechanism by the air cylinder A4 for bending the elbow joint described above, and one ends of the two air cylinders A1 and A2 are fixed to a support member 20 which is arranged to extend rearward from the shoulder of the robot. The other end is connected to a link mechanism having the same structure as the elbow joint.

Specifically, the joint P _{2,2 at} the tip of the rod of the air cylinder A 1 and the joint P _2,3 on the upper arm joint are used.
A link L _2,2 is inserted between and, and they are connected by the link L _2,2 . The link L _2,1 has one end connected to the shoulder joint side by a joint P _2,4 and the other end connected to the rod tip and a joint P.
_Connect with _2,2 . Here, the lengths of the links L _2,1 and L _2,2 and the fixed positions of the joints P _2,3 and P _2,4 in each node are set so that the link L _2,2 is a shoulder joint when the elbow joint bends. Decide to move around the outside. While connected similarly to the upper arm section via the air cylinder A2 also link mechanism, a description of details because the configuration is the same as the joint J ₂ is omitted. However, in the shoulder joint, the two joints are orthogonal to each other, and the driving mechanism thereof is concentrated, so that the structure becomes slightly complicated.

In this robot hand, in order to give the air cylinders A1 and A2 a function of counterweight for compensating the weight of the mechanism existing from the shoulder to the wrist,
Both air cylinders are arranged so as to project to the opposite side of the arm. It should be noted that this is an example of the arrangement of the drive mechanism, and if necessary, changes such as arranging the air cylinder along the side surface of the body of the robot can be easily made.

[Wrist Mechanism] A compact drive mechanism that realizes the rotational movement of the wrist joint will be described. 14 is a perspective view and an exploded perspective view of the wrist joint drive mechanism.
5 is a top view, a side view, and a perspective view of the drive mechanism. This drive mechanism is devised to make the mechanism compact while making the axes of the two joints J _{6 and} J ₇ orthogonal to each other at one point on the central axis of the forearm joint.

In order to separate the movements of the joint J ₆ and the joint J ₇ , a wrist joint 5 as an intermediate joint is provided between the forearm joint and the humanoid robot hand, and the movement of the joint J ₆ is performed by the forearm joint and the wrist joint. 5 and the movement of the joint J ₇ is the rotation movement between the wrist joint 5 and the robot hand (see FIGS. 14 and 15). As shown in the figure, the shape of the wrist joint 5 is a cross shape when viewed in the axial direction of the forearm joint, and the joints ₆ and ₇ are jointed so that the axes of the joints J ₆ and J ₇ are orthogonal at one point on the central axis of the forearm joint The bearings 22 and 23 of 4 are arranged on the four sides of the cross girder, and the movement areas of the structural members are secured.

Further, a spare space is provided at the center of the cross-shaped wrist joint 5 so that a wire for connecting the humanoid robot arm and the humanoid robot hand can be passed through. However, in FIG. 14, among encoders for measuring each displacement of each joint, the encoder 24 of the joint J ₆ is arranged in the space. The range of motion of the wrist joint 5 need not be so large as compared with the shoulder joint and the elbow joint (see FIG. 4). Therefore, from the viewpoint of simplifying the mechanism, the drive mechanism is of the general type shown in FIG. 11 described above. That is, in each joint, a joint is provided on each of the two joints connected by the joint, they are connected by an air cylinder, and the distance between them is increased or decreased by the movement of the rod of the air cylinder to rotate the joint. .

As described above, in the above embodiment of the present invention, the air cylinder is built in the arm,
A compact humanoid robot arm with 7 degrees of freedom
Could be configured. It should be noted that the material forming the robot arm, the shape of the parts of each member, and the like can be appropriately changed in design within the scope of the present invention. Further, the present invention does not depart from the spirit or the main features thereof.
It can be implemented in any other form. Therefore, the above-described embodiments are merely examples in all respects and should not be limitedly interpreted.

[0034]

As described above in detail, according to the present invention, the air cylinder itself is made to have a high strength, and the air cylinders are incorporated in the axes of the upper arm joint and the forearm joint of the arm so that the upper arm joint and the forearm joint are integrated. A compact humanoid robot arm can be configured by adopting an endoskeletal structure in which most of the structural members of the node are also used by the air cylinder. Also,
By adopting the compact feed screw mechanism that converts the linear motion of the air cylinder into the rotational motion about the axis, it is possible to realize a twisting motion range of ± 90 degrees in the upper arm node and the forearm node. A link mechanism that efficiently transfers the output of the air cylinders to the joints is used for rotational movements of the wrist, elbow, and shoulder joints other than the twisting of the arm joints. With
It is possible to realize a large range of motion of those joints, and it is possible to achieve excellent effects such as.

[Brief description of drawings]

FIG. 1 is a perspective view showing an overall image of a robot arm.
This figure corresponds to the human right arm, and the arm corresponding to the left hand is symmetrical to this.

FIG. 2 is a general view of a doll robot having both arms and both hands, in which a robot arm is connected to a body of a humanoid robot and a humanoid robot hand.

FIG. 3 shows an arrangement of seven joints in a robot arm and a name.

FIG. 4 shows a range of motion of each joint of the robot arm.

FIG. 5 is a perspective view illustrating a skeleton structure in the forearm joint including the joint J ₅ for rotating the forearm joint about an axis.

FIG. 6 is an exploded view illustrating a skeletal structure in the forearm segment.

FIG. 7 is an exploded explanatory view of a feed screw mechanism arranged in a forearm joint.

FIG. 8 is a plan view of a forearm segment and a cross-sectional view taken along line AA in FIG.

9 is an enlarged cross-sectional view taken along the line BB in FIG.

10 is an enlarged view of portion C in FIG.

FIG. 11 is an explanatory diagram of the format of a general drive mechanism.

FIG. 12 is an explanatory diagram of a drive mechanism for rotating the elbow joint about a joint J ₄ .

FIG. 13 is an explanatory diagram of a drive mechanism for rotating the shoulder joint about joints J ₁ and J ₂ .

FIG. 14 is a perspective view and an exploded perspective view of a wrist joint drive mechanism.

FIG. 15 is a plan view, front view, and perspective view of the drive mechanism.

[Explanation of symbols]

1 shoulder joint 2 upper arm joint 3 elbow joint 4 forearm joint 5 wrist joint 6 shoulder joint 7 wrist joint 8 gear 9 encoder 9a gear 10 outer member 11 cam member 12 rotation prevention guide 13 rod 14 cam follower 15 bearing 16 cylinder tube 17, 18 block 20 supporting member J ₁ through J ₇ joint

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Sei Hoshino             Okinawa Prefecture Ginowan City Shimashi 1-10-1-203 (72) Inventor Ichiro Kawabuchi             3-1-9 Shin Kamata Green, Ota-ku, Tokyo             Copy 203 F term (reference) 3C007 BS27 CU05 CV09 CW08 CW10                       CX01 CY36 HS14 HT21 HT33                       KV01 KX10

Claims (8)

[Claims] 1. An air cylinder as a joint drive actuator in a 7-DOF humanoid robot arm which is composed of a shoulder joint, a brachial joint, an elbow joint, a forearm joint, and a wrist joint and is driven by air pressure. A humanoid robot arm characterized in that is used as an internal skeletal structural member of the upper arm joint and the forearm joint. 2. A joint that realizes a twisting movement around the axis of each of the upper arm joint and the forearm joint is arranged at the center of the joint and is driven by the expansion and contraction movement of a rod of an air cylinder that also serves as a structural member of the joint. The humanoid robot arm according to claim 1, further comprising a built-in feed screw mechanism. 3. The feed screw mechanism has a cam member having a spiral cam groove on an inner wall of a cylindrical space, and the cam member is inserted into the cylindrical space of the cam member to be fitted into the cam groove, and the feed screw mechanism of the air cylinder. The humanoid robot arm according to claim 2, comprising a cam follower attached to the tip of the rod. 4. A rod of the air cylinder is configured to expand and contract in a state in which a rotation preventing guide that is housed in a cylindrical space of the cam member prevents rotation of the air cylinder about its axis. The humanoid robot arm according to claim 3, wherein. 5. The upper arm joint and the forearm joint are each composed of two joints connected with each other with the joint for twisting motion sandwiched therebetween, one of the joints being the air cylinder and the other joint being the cam member. 5. The cam member is arranged, and the cam member is rotated via the cam follower by operating the air cylinder to expand and contract the rod, and as a result, the brachial joint and the forearm joint are twisted about their axes.
The humanoid robot arm described in. 6. The bending motion in the shoulder joint and the elbow joint constructs a four-bar linkage mechanism between a driving-side node having a driving air cylinder and a driven-side node through which a driving air cylinder is driven. The humanoid robot arm according to any one of claims 1 to 5, wherein the range of motion is expanded by transmitting the expansion and contraction movement of the rod. 7. The humanoid robot arm according to claim 6, wherein a part of the air cylinder also serves as a balance weight. 8. The wrist joint is rotationally moved in two degrees of freedom, and the two rotational axes and three of the axes of the forearm joints are set to one with respect to each other.
A girder-shaped member that has a space for wiring and piping in the center is provided between the knotted joint and the forearm knot, and drives the rotational movement between the knotted joint and the girder-shaped member. The humanoid robot arm according to any one of claims 1 to 7, wherein the humanoid robot arm is configured by an air cylinder that operates and a rotational movement between the cross beam member and the forearm joint.