JP2003340770A - Robot - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology for regulating the rigidity of a robot joint. <P>SOLUTION: A robot comprises a body side member 42, a distal end side member 18 rotatably connected to the body side member 42, at least two wires (66a, 66b and 66c) with end parts thereof fitted to both sides across the center of rotation of the distal end side member 18, at least two actuators connected to the other end parts of the wires (66a, 66b and 66c) to extend/contract each wire, and a controller to control the actuator group. The controller inputs information on the tension exerted in the wires (66a, 66b and 66c), and outputs the working quantity of each actuator. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a robot. In particular, the present invention relates to a technique capable of adjusting the rigidity of a robot joint.

[0002]

2. Description of the Related Art Development of humanoid robots or animal robots having upper and lower limbs has been activated. Such a robot connects a body-side member with a terminal-side member through a joint and rotates the joint to walk, hold an object, or operate an object. Rotation of a joint is performed by rotation of a motor attached to the rotation shaft of the joint, or by pulling a wire connected to a pulley attached to the rotation shaft of the joint by an actuator. In addition,
Here, the "body side member and the terminal side member" means, for example, "body part and head part", "body part and upper arm part", "upper arm part and forearm part", "forearm part and palm part", ""Palm and fingers", "body and thighs", "thighs and crus", "crus and feet", etc. The foot portion means a member on the distal side of the ankle joint.

[0003]

However, the robot described above cannot adjust the rigidity of the joint.
Therefore, the end member cannot flexibly follow the outside. For example, when the foot touches the uneven ground, if the ankle joint is flexible, the foot can follow the unevenness of the ground, but if it is not flexible (high rigidity), the foot becomes uneven on the ground. Cannot imitate. If the foot cannot follow the unevenness of the ground, the robot loses balance and falls. However, if it is always flexible, it is not possible to perform agile motions, for example, and the posture is easily disturbed by external disturbance, and it is not appropriate to always be flexible.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a technique capable of adjusting the rigidity of a joint of a robot. In the present invention, two wires are connected to both sides sandwiching the center of rotation of the rotatable member, and one wire is pulled to rotate clockwise,
By adopting the so-called pull-pull method that rotates in the counterclockwise direction by pulling with the other wire, by inserting a non-linear spring (a spring that is not proportional to tension and elongation and becomes more difficult to stretch as tension increases) to the wire, The purpose is realized by utilizing the knowledge that the rigidity can be adjusted independently of the posture of the robot.

[0005]

According to a first aspect of the present invention, there is provided a robot, wherein a body side member, an end side member rotatably connected to the body side member, and a rotation of the end side member. At least two wires having ends attached to both sides of the center and at least two actuators connected to the other end of each wire to expand and contract each wire are provided. With this configuration, the distal member can be rotated by pulling one wire and loosening the other wire. This allows the joint angle to be changed. On the other hand, if both wires are pulled hard, the wire tension can be increased without changing the rotation angle of the joint. The rigidity of the joint can be increased by increasing the tension of both wires. In the robot according to the first aspect, the controller that controls the actuator group inputs the information about the rotation angle of the end member and the information about the tension applied to the wire, and outputs the operation amount of each actuator. When the controller outputs the operation amount to each actuator based on the information about the rotation angle of the distal end member and the information about the tension applied to the wire, the distal end member is rotated to the rotation angle input to the controller and the tension of the wire is Adjusted to the tension input to the controller. With this, both the rotation angle and the tension can be adjusted to the input values. Note that it is not necessary to input the information about the tension applied to the wires for all the wires. If you specify the tension of one wire, from the balance of forces to maintain the end member at the desired rotation angle,
This is because the tension of the other wire can be calculated.

In the robot according to the first aspect, the controller calculates the wire length from the information about the rotation angle of the distal end member, and the controller calculates the extension length of the wire from the information about the tension. 2 calculation part and 3rd part which calculates the actuator operation amount from the calculation results of both calculation parts
It is preferable to have a calculation part (Claim 2). When the operation amount thus calculated is output from the controller and each actuator is operated, both the rotation angle of the end member and the wire tension are adjusted to the intended values.

According to a third aspect of the present invention, there is provided a robot body-side member, an end-side member rotatably connected to the body-side member, and end portions attached to both sides of a rotation center of the end-side member. At least two wires, at least two actuators connected to the other end of each wire to expand and contract each wire, and a controller that controls this actuator group. Then, the controller of the present invention inputs the information regarding the rotation angle of the distal end member and the information regarding the rigidity for maintaining the distal end member at the rotational angle, and outputs the operation amount of each actuator. In addition, the rigidity here means the degree of easiness of rotation of the end member with respect to the force applied to the end member. If the rigidity is low, it will rotate easily, and if the rigidity is high, it will not rotate easily. When the controller outputs the operation amount to each actuator based on the information about the rotation angle of the distal member and the information about the rigidity to keep the distal member at that rotation angle, the distal member is rotated to the rotation angle input to the controller. In addition, the rigidity at that time is adjusted to the value input to the controller.

In the robot according to the third aspect, the controller calculates the wire length from the information about the rotation angle of the distal end member, and the controller calculates the extension length of the wire from the information about the rigidity. 2 calculation part and 3rd part which calculates the actuator operation amount from the calculation results of both calculation parts
It is preferable to have a calculation part (Claim 4). Generally, the higher the wire tension, the higher the rigidity of the joint. However, not only the tension but also the arm length of the moment measured from the center of rotation influences the rigidity. For example, assume that the wire tension is 1 kg in both cases. At this time, 1k from the center of rotation
The length to the point of application of the tension of g is 10 cm (case 1) and 20 cm (case 2). At this time, the case 2 has a longer moment arm and a larger moment.
The case 2 has the same tension, but the degree of maintaining the joint rotation angle against the external force is stronger. Stiffness is determined by tension and moment arm length. Second of the controller
When the rigidity is specified, the calculation unit calculates the tension required to adjust to the specified rigidity from the specified rigidity and the arm length of the moment at that time, and then adjusts to that tension. Calculating the length of wire elongation required for
The flexibility around the joint can be adjusted to the specified rigidity without depending on the posture of the robot. When each actuator operates according to the operation amount calculated in this way,
Both the angle of rotation of the distal member and the stiffness of the joint are adjusted to the intended values.

In the robot according to any one of claims 1 to 4, it is preferable that a non-linear spring is inserted in each wire (claim 5). By inserting a non-linear spring (a spring in which tension and elongation are not proportional to each other and becomes more difficult to stretch as the tension increases) into the wire, it is possible to increase the rigidity by increasing the tension.

In the robot according to any one of claims 1 to 5, it is preferable that the body side member is a lower leg and the end side member is a foot (claim 6). By adjusting the rotation angle and rigidity of the foot, the foot can follow the unevenness of the ground.

In the robot according to claim 6, it is preferable that the high rigidity is instructed when the foot portion should be in the air, and the low rigidity is instructed during the ground contact (claim 7). If high rigidity is instructed when the foot is in the air, the foot does not easily move due to external force such as moment of inertia, and the walking posture of the robot is stabilized. In addition, if the foot portion indicates low rigidity during contact with the ground, the foot portion can follow the unevenness of the ground.

[0012]

DETAILED DESCRIPTION OF THE INVENTION A first embodiment embodying the present invention will be described with reference to FIGS. In the present specification, the front-back direction of the foot (the robot moving direction) is the X axis, the left-right direction is the Y axis, and the direction in which the lower leg or the trunk extends is the Z axis. The axes are orthogonal to each other. The first embodiment is an application of the present invention to the lower limb of a robot. The shape of the lower limbs is mirror symmetric. 1 is a front view of both lower limbs of the robot of the present embodiment, FIG. 2 is a side view of the left lower limb, and FIG. 3 is a diagram for explaining the structure of the ankle joint.
FIG. 4 is a diagram for explaining the details of the ball screw, and FIGS.
4 is a diagram for explaining the movement of the foot.

As shown in FIG. 1, the robot 1 of the present embodiment.
The left and right lower limbs 12 of 0 are composed of a thigh 14, a lower thigh (shin) 16 and a foot 18, and the thigh 14 and the body 20 are connected by a hip joint 22. Thigh 1
6 is connected by a knee joint 24, and the lower leg portion 16 and the foot portion 18 are connected by an ankle joint 26.

First, the hip joint 22 will be described. As shown in FIG. 2, a disc 36 that rotates about the Z axis is attached to the pelvic portion 28 that extends in a substantially horizontal direction by bearings 34. A pair of discs 36 are provided on the left and right sides in FIG. At the center of each disc 36, extends from the pelvis 28 side to the thigh 14 side (extends in the Z-axis direction).
The shaft 30 is fixed. The shaft 30 rotates about the Z axis with respect to the pelvis 28. The upper end of the thigh 14 is universal joint 3 with respect to the lower end of the shaft 30.
Connected by two. Universal joint 3
2 shows that the thigh 14 is rotated around the X axis and Y with respect to the shaft 30.
Allows rotation around an axis. The hip joint 22 includes a shaft 30 that can rotate about the Z axis with respect to the pelvis 28,
A universal joint 32 that allows the thigh 14 to rotate with respect to the shaft 30 about the X axis and the Y axis.
And is a triaxial joint that allows rotation around each of the X, Y, and Z axes.

Next, the knee joint 24 will be described. Each thigh 14
Two flanges 40 arranged in parallel with each other in the Y-axis direction extend downward at the lower end of each of the shafts 4 constituting each leg portion 16.
At the upper end of 2, two flanges 44 are arranged in parallel with the Y-axis direction.
Is provided facing upward. The knee joint 24 includes a shaft 46 that extends through the flanges 40 and 44 in the Y-axis direction. The knee joint 24 has the lower leg 16 with respect to the thigh 14.
Is allowed to rotate around the Y axis.

Next, the ankle joint 26 will be described. FIG. 3 is a simplified and deformed view for explaining the structure of the ankle joint 26, and does not necessarily match the actual shape and size. Two flanges 58, which are arranged in parallel with each other in the X-axis direction, extend downward in the lower portion of the shaft 42 of the lower leg 16. Further, on the upper surface of the foot portion 18, two flanges 60 aligned in parallel with the Y-axis direction extend upward. The flange 58 of the lower leg 16 and the flange 60 of the foot 18 are connected by a cross type universal joint 62 to form a universal joint. The ankle joint 26 is used for the lower leg 24 and the foot 1
8 is allowed to rotate about the X axis and the Y axis.
That is, the ankle joint 26 is a biaxial joint having degrees of freedom in each of the X and Y axes.

Each joint is driven by a wire (excluding rotation of the hip joint about the Z axis; only this rotation is directly rotated by a motor without using the wire). One end of each wire is attached to the end member, and the other end is connected to an actuator composed of a ball screw and a motor. The motor rotates the feed screw (extends in the Z direction) of the ball screw, and the nut screwed to the feed screw is fed in the feed screw direction, and the tip of the wire connected to the nut moves in the Z axis direction. Go back and forth. By moving the tip of the wire forward and backward in the Z-axis direction, the distal member can be pulled or loosened by the wire.

First, the wire group for rotating the ankle joint will be described with reference to FIG. The foot 18 is attached to the wire end guides 70a, 70b, 70c by a mounting plate (not shown).
Is fixed. Each wire end guide 70a, 70
b and 70c are arcuate shapes, the center axis of each arc extends in the Y-axis direction, and the arcuate surface has a predetermined width (distance extending along the Y-axis). Wire end guide 70
“A” is located in front of the Y-axis of the ankle joint 26 and is arranged on the X-axis. The arc surface faces the front of the X axis. The wire end guides 70b and 70c are located posterior to the Y axis of the ankle joint 26. The wire end guide 70b is located outside the X axis of the ankle joint 26, and the wire end guide 70c is located inside the X axis of the ankle joint 26. The arcuate surfaces of the wire end guides 70b and 70c face the rear side of the X axis. Three wires 66a, 66b, 66c
The lower ends of the wire end guides 70a, 70b, 70c are respectively the wire connecting points 72a, 72b, 72c at the lower ends.
The other ends of the respective wires 66a, 66b, 66c extend toward the knee joint 24 side. The wire end guides 70a, 70b, 70c are curved along the arcuate surface. The wire end guides 70a, 70b, 70c inhibit the wires 66a, 66b, 66c from sharply bending with a small radius of curvature.

The wire connection point 72a is located in front of the Y-axis of the ankle joint 26, and the wire 66a is connected to the knee joint 24.
When pulled to the side, the foot portion 18 rotates around the Y axis of the ankle joint 26 and lifts the toe. The wire connection point 72a is arranged on the X axis of the ankle joint 26, and even if the wire 66a is pulled toward the knee joint 24 side, it does not affect the rotation angle of the foot 18 around the X axis. The wire connection point 72b is located outside the X axis of the ankle joint 26, and the wire 66b is connected to the knee joint 24.
When pulled to the side, the foot portion 18 rotates around the X axis of the ankle joint 26 and lifts the outside of the foot portion 18. Wire connection point 72
c is located inside the X axis of the ankle joint 26, and when the wire 66c is pulled toward the knee joint 24 side, the foot portion 18 rotates about the X axis of the ankle joint 26 and lifts the inside of the foot portion 18. . When lifting the inside of the foot 18, the wire 6
At the same time as pulling 6c, the wire 66b is loosened to allow the outside of the foot 18 to lower. Similarly, when lifting the outside of the foot 18, the wire 66b is pulled and at the same time the wire 66c is loosened to allow the inside of the foot 18 to lower. When rotating the foot portion 18 around the X axis of the ankle joint 26, it is not necessary to operate the wire 66a. Wire 66
When both b and 66c are pulled at the same time, the foot part 18 is Y of the ankle joint 26.
Rotate around the axis and lift the heel. In this case,
Loosen the wire 66a to allow the toe to fall. When pulling the wire 66a and lifting the toe,
Loosen 6b and 66c to allow the heel to fall. Three
The rotation angles of the ankle joint 26 about the X axis and the Y axis can be independently adjusted by the wires 66a, 66b, 66c of the book.

The wire connection points may be arranged on both sides of the X axis in front of the Y axis of the ankle joint 26 and on the X axis behind the Y axis. Even if the wire connection points are arranged in this way, the rotation angle of the ankle joint 26 around the X axis and the rotation angle around the Y axis can be independently adjusted by the wire.

5 to 10 are schematic diagrams for explaining the movement of the foot portion 18, and FIGS. 5 and 6 are diagrams for explaining the rotation around the X axis. FIG. 5 is a plan view of the foot portion 18,
FIG. 6 is a rear view of the foot portion 18. Each wire 66a, 66
At the ends of b and 66c, wire end guides 70a and 70
Illustrations of b and 70c are omitted, and wire connection points 72a and 72a
Only b and 72c are shown.

In FIG. 5, the wire (not shown) connected to the wire connecting point 72a contracts the effective length of the wire 66b connected to the wire connecting point 72b while maintaining the neutral state, and the wire connecting point 72c It is shown that the effective length of the wire 66c connected to is extended. At this time, the foot portion 18 rotates about the X axis in the direction of the arrow as shown by the broken line in FIG. Also, increase the effective length of the wire
When the contraction is reversed, the foot 18 rotates in the direction opposite to the arrow. That is, by adjusting the extension / contraction of the effective length of the wire in this manner, the foot portion 18 can be freely rotated around the X axis.

7 and 8 are views for explaining the rotation around the Y axis. FIG. 7 is a plan view of the foot portion 18, and FIG. 8 is a side view of the foot portion 18. Each wire 66a, 66b, 6
At the end of 6c, wire end guides 70a, 70b, 70
Illustration of c is omitted, and wire connection points 72a, 72b, 72
Only c is shown. FIG. 7 shows that the effective length of the wire 66a connected to the wire connection point 72a is contracted, and the wires 66b and 6 connected to the wire connection points 72b and 72c are contracted.
It shows a case where the effective length of 6c is extended together. At this time, the foot portion 18 rotates about the Y axis in the direction of the arrow, as shown by the broken line in FIG. Also, increase the effective length of the wire
When the contraction is reversed, the foot 18 rotates in the direction opposite to the arrow. By adjusting the extension / contraction of the effective length of the wire in this manner, the foot 18 can be freely rotated around the Y axis. The tension of the wire required to lift the rear side of the foot 18 is larger than the tension of the wire required to lift the front side of the foot 18. Therefore, 3
It is preferable that one of the wire connection points 72a, 72b, 72c is set to the front side and two points are set to the rear side, and the heel is lifted by two wires and two actuators. In this case, the capabilities of each actuator can be made equal.

Although not shown in the drawing, the foot 18 is simultaneously moved to the X position.
It can be rotated both around the axis and around the Y axis. For example, the effective length of the wire 66b is contracted at a speed ab, and the effective length of the wire 66c is elongated at a speed a + b (that is, -a).
-B) and the effective length of the wire 66a is contracted by b, the foot portion 18 rotates around the X axis at a speed a and rises outward, and rotates around the Y axis at a speed b. The front side goes up. By simultaneously adjusting the effective lengths of the three wires in this manner, the foot portion 18 can be freely rotated around the X axis and the Y axis at the same time. Also, the rotation speed around the X axis and the rotation speed around the Y axis can be freely adjusted. From these facts, it is possible to adjust the X and Y axes independently of each other by using three wires for the two X and Y axes, that is, the number of wires plus one wire.

As shown in FIG. 3, on the upper portion of the shaft 42 of the lower leg 16, three pulleys 64a, 64 which are freely rotatable around a Y-axis direction axis 46 passing through the flange 44 are provided.
b and 64c are arranged alternately with the two flanges 44. Wires 66a, 66b and 66c are wound around the pulleys 64a, 64b and 64c, respectively. The wires 66a, 66b, 66c are connected to the pulleys 64a, 64.
It is separated from the pulley on the front side of b and 64c. Wire 6
6a, 66b, 66c apply a tensile force to the foot 18 from the front position of the knee joint. For this, three wires 6
When 6a, 66b, and 66c are simultaneously contracted at the same speed, the rotation angle of the foot 18 with respect to the lower leg 16 is not changed (the ankle joint 26 is not rotated), and the lower leg 16 is moved around the knee joint 24. It can be rotated forward.

Next, the movement of the wire associated with such movement of the foot will be described. 9 to 10 are schematic diagrams for explaining the movement of the wire accompanying the rotation of the foot portion 18, and do not necessarily match the actual shape and dimensions. 9 is a rear view of the foot portion 18 when it is rotated about the X axis, and FIG. 10 is a left side view of the foot portion 18 when it is rotated about the Y axis.
Note that the wire can be approximately extended in the vertical direction.

FIG. 9 is a view showing a state in which the foot portion 18 is rotated about the X axis of the ankle joint 26 in the arrow direction to the maximum extent (15 ° in this embodiment). A state where the foot portion 18 is perpendicular to the shaft 42 of the lower leg portion 16 is shown by a solid line, and the position 18-1 of the foot portion 18 at this time is a normal position. The foot portion 18-1 and the wires 66b1 and 66c1 in the normal position, and wire end guides 70b1 and 70c for guiding them, respectively.
1 is indicated by a solid line (the last subscript 1 indicates that it is at the reference position). The foot 18 rotated around the X axis is shown by a broken line 18-2, and the wires 66b2 and 66c2 at that time are shown.
And the wire end guides 70b2 and 70c2 are indicated by broken lines (the last subscript 2 indicates the rotational position). Lower end connection points 72b1 and 72c of the wires 66b1 and 66c1
1 is at the center in the Y-axis direction of the lower ends of the wire end guides 70b1 and 70c1. In the normal position, the wires 66b1 and 66c1 are connected to the wire end guides 70b1 and 70c.
It is guided along the center line of the arc surface of c1 in the Y-axis direction. When the foot portion 18 rotates around the X axis and moves to the position of the foot portion 18-2, the wires 66b and 66c are guided by the wire end guides 70b and 70c, and the wires 66b2 and 66b2.
Move to position 66c2. At this time, the wire end guides 70b2 and 70c2 are inclined with respect to the wires 66b2 and 66c2. The line on the arc surface of the wire end guides 70b2, 70c2 for guiding the wires 66b2, 66c2 moves to the line connecting the wire connecting portions 72b2, 72c2 and the wire end guides 70b2, 70c2 to the upper right end in the figure. Although not shown, the wires 66b2 and 66c are also similarly rotated in the case where the wires 66b2 and 66c are fully rotated in the direction opposite to the arrow in FIG.
2 moves to the line connecting the upper left ends of the wire connecting portions 72b2, 72c2 and the wire end guides 70b2, 70c2 in the figure.

The width of the wire end guide 70 in the Y-axis direction is
Since the foot portion 18 rotates about the X axis, the distance between the X axis and the wire connection point 72 is set to be greater than or equal to the changing distance. Therefore, the foot portion 18 rotates about the X axis to the maximum extent. However, the wire 66 does not come off the wire end guide 70. As described above, according to the wire end guide 70 of the present embodiment, it is possible to continue guiding the wire 66 regardless of any posture change of the distal end member 18 around the X axis. In addition, in the present specification, an event described by omitting the subscript indicates that the event is common to members divided by the subscript.

FIG. 10 is a side view of the ankle joint 26 of this embodiment when it rotates around the Y axis. In order to compare with the movement of the wire in the present embodiment, the movement of the wire when the wire termination guide 70 is not provided will be described first with reference to FIG. 11.

In the absence of a wire end guide, the ankle joint 226 consists of a wire 266 attached to the front (left side of the figure) of the universal joint Y-axis 262 and a wire attached to the rear (not shown) of the Y-axis 262.
Is rotated around. The lower end of each wire is the foot 218
Is fixed to the wire connection portion 272 (the connection point of the rear wire is not shown) on the upper surface of the above, and the upper end is connected to an actuator (not shown). The actuator extends and contracts the effective length of each wire, causing the foot 218 to rotate about the Y-axis 262. Note that the wire can be approximately extended in the vertical direction.

The broken line in FIG. 11 indicates that the foot 218 is the ankle joint 2.
26 around the Y-axis 262, which has been rotated to the maximum in the directions of arrows III and IV. The normal position in which the angle formed by the foot 218 and the shaft 242 of the lower leg 216 is a right angle is indicated by a solid line (subscript 1 indicates the normal position). At this time, the angle α formed by the foot portion 218-1 and the wire 266-1 is also a right angle. The foot portion 218-3, the wire 266-3, and the wire connecting portion 272-3 after being rotated in the direction of the arrow III (clockwise in the drawing) are indicated by broken lines and the subscript 3 is attached. The foot portion 218-4, the wire 266-4, and the wire connecting portion 272- which are rotated in the direction of arrow IV (counterclockwise in the drawing).
4 is shown by a broken line, and the subscript 4 is attached. The angle β formed by the foot 218-3 rotated in the direction of the arrow III and the wire 266-3 is larger than α at the normal position, and the angle IV
The angle γ formed by the foot 218-4 rotated in the direction and the wire 266-4 is smaller than α at the normal position. That is,
The angle formed by the foot 218 and the wire 266 changes as the foot 218 rotates. In the method without the wire guide of FIG. 11, the wire 266 bends sharply at the connection point 272, so that the wire 266 is easily broken at the connection point 272.

When the foot 218 rotates about the Y-axis, the wire connecting portion 272 on the upper surface of the foot 218 also rotates accordingly. Y-axis 26 when rotated in the direction of arrow III
The horizontal distance La between the wire connection point 272-3 and the wire connection point 272-3 is larger than the normal position, and the horizontal distance L between the Y axis 262 and the wire connection point 272-4 when rotated in the direction of arrow IV.
b is smaller than the normal position. This distance La and Lb
Is the arm length that directly connects to the magnitude of the moment that rotates the foot portion 218 around the Y-axis 262. If the tension applied to the wire is the same, the longer the arm length, the greater the moment. In the method without the wire guide of FIG. 11,
The arm length greatly changes depending on the posture of the foot 218, and the magnitude of the moment that rotates the foot 218 greatly changes.

On the other hand, FIG. 10 shows the ankle joint 26 of this embodiment.
And the wire end guide 70 and the like. It is shown that the foot portion 18 is rotated about the Y axis 62 of the ankle joint 26 in the directions of arrows III and IV to the maximum extent (30 ° in the present embodiment). The angle formed by the foot 18 and the shaft 42 of the lower leg 16 in the standard position is a right angle, and the position of the foot 18-1 at this time is the normal position (subscript 1 indicates the normal position). ). Foot 18-1 and wire 66a in normal position
1 and a wire end guide 70a1 for guiding the wire 1 are shown by solid lines. The foot portion 18-3, the wire 66a3, and the wire end guide 70a3 after rotating in the direction of arrow III (clockwise in the drawing)
And connection point 72a3 and arrow IV direction (counterclockwise in the figure)
After the rotation, the foot 18-4, the wire 66a4, the wire end guide 70a4, and the connection point 72a4 are shown by broken lines.

As described above, the lower end of the wire 66a attached to the foot portion 18 is fixed to the wire connecting portion 72a at the lower end of the wire end guide 70a. The wire end guide 70a is attached such that the center of its arc is always closer to the lower leg 16 than the wire connecting portion 72a. That is, the vicinity of the lower end of the wire 66a is always guided along the arc surface of the wire end guide 70a. For this reason, the wire 66a does not locally and sharply bend due to the change in the posture of the foot, and the wire is hard to break.

When the foot portion 18 rotates about the Y axis 62, the guide portion of the wire end guide 70a of the wire 66a by the arc surface changes as follows. In the normal position, the wire 66a1 is guided from the lower end of the arc surface of the wire end guide 70a1 to a position having a center angle of 90 °.
When rotated in the direction of arrow III, the wire 66a3 is guided to a position about one third from the lower end of the arc surface of the wire end guide 70a3. When rotated in the direction of arrow IV, the wire 66a4 is guided from the lower end of the arc surface of the wire end guide 70a4 to the vicinity of the upper end. That is, even if the foot portion 18 rotates, the length of the wire 66a guided by the wire end guide 70a changes, so that the wire 66a is changed.
The horizontal distance from the wire guide 70a to the Y-axis 62 is kept substantially constant. As a result, in the system having the wire end guide 70 of FIG. 10, even if the posture of the foot portion 18 changes, the change in the arm length is small, and the change in the moment for rotating the foot portion 18 is also small.

Without the wire termination guide, the wire locally bends at the wire connecting portion every time the distal member such as the foot moves, so that it is not easy to maintain the durability of the wire connecting portion. In the present embodiment, since the wire end guide is provided, even if the foot rotates about the Y axis, the vicinity of the lower end of the wire is always guided by the arc surface of the wire end guide. There is no local bending, and the durability of the wire connection portion is improved. Also,
Without the wire end guide, the distance between the wire and the Y axis, that is, the arm length of the moment, changes greatly every time the distal member such as the foot moves. In the present embodiment, since the wire end guide is provided, even if the foot rotates about the Y axis, the wire end guide can suppress the change in the arm length of the moment. In addition, the wire end guide of this embodiment is Y
It has a width in the axial direction, and the wire does not come off the wire end guide even when the foot portion 18 rotates around the X axis.

In the present embodiment, by utilizing the wire end guide, it is possible to maintain the durability of the wire connecting portion with respect to the posture change of the distal side member around the X axis and the Y axis. Further, it is possible to suppress the change in the arm length of the moment with respect to the change in the posture of the terminal side member around the X axis and the Y axis. Furthermore, because the wire end guide is wide,
The wire can always be guided near the wire connection point without departing from the wire termination guide. Even if the wire is guided by forming a groove in the wire end guide, the wire can be prevented from deviating from the wire end guide, but the wire may locally and sharply bend when the wire separates from the groove. Since the wire end guide of this embodiment has no groove, the wire is free to move in the axial direction along the arc surface of the wire end guide, and is widened so as not to deviate from the wire end guide. It has succeeded in always guiding while avoiding sharp bends.

The three wires 6 shown clearly in FIG.
Ball screws 68a, 68 are provided at the upper ends of 6a, 66b, 66c.
b, 68c (see FIGS. 1 and 2). In FIGS. 1 and 2, the ball screw is simplified and shown for the sake of clarity. FIG. 4 schematically shows the details of the ball screw 68 (all ball screws have the same structure, and therefore will be described in common with the suffix omitted), and the pair of flanges 102 and 106 are three. They are connected by guide rods 108, 110 and 112. A feed screw 120 is rotatably disposed between the pair of flanges and is immovable in the axial direction. The lead screw 120 is the motor 1
It is rotated by 14, gear 116 and gear 118. The movable plate 104 is screwed onto the feed screw 120. The movable plate 104 is a guide rod 108, 11.
Guided by 0 and 112, it is movable in the axial direction and cannot rotate. The tip of the wire 66 is fixed to the movable plate 104. When the motor 114 rotates, the feed screw 120 rotates, the movable plate 104 slides along the guide rod, and the wire 66 is pulled in or loosened. The motor of the ball screw 68 is fixed to 114, and the pair of flanges 102 and 106 are fixed to the thigh portion 14.
The guide rods 108, 110, 112 extend in the longitudinal direction of the thigh 14, and the motor 114 rotates the ball screw 68 so that the wire 66 is pulled or loosened in the longitudinal direction of the thigh 14. Or Wires 66a, 66
b, 66c pulleys 64a, 64b, 64c and connection point 7
Assuming that the distance between 2a, 72b and 72c is the effective length of the wire, the effective length of the wires 66a, 66b and 66c is the motor 1
It is extended by 14. Wires 66a, 66b,
An actuator group (composed of a motor group and ball screw groups 68a, 68b, 68c) for extending the effective length of 66c is arranged in the thigh portion 14 near the hip joint 22.

As shown in FIG. 4, the ball screw 6
The controller 200 is connected to 8. The controller 200 includes a first calculation unit 200a and a second calculation unit 200.
b, the third calculation unit 200c. Controller 2
A signal indicating the rotation angle of the ankle joint 26 and the tension of each wire (66a, 66b, 66c) is input to 00 from another controller (not shown) that controls the entire movement of the robot 10. The first calculation unit 200a of the controller 200 calculates the effective length of each wire (66a, 66b, 66c) having the input value of the rotation angle of the ankle joint 26. The second calculator 200b calculates the extension length of each wire (66a, 66b, 66c) so that the tension becomes the input value. The third calculator 200c is the first calculator 20.
0a and the calculation result of the second calculation unit 200b, the ball screw 6
The operation amount of the movable plate 104 of 8 is calculated. The calculated operation amount of the movable plate 104 is output to the ball screw 68, and the ball screw 68 operates according to this output.

As shown in FIG. 2, one end of a wire 66d for rotating the crus 42 backward around the knee joint 24 is connected to the crus 42. The wire 66d passes behind the pulley 64d (see FIG. 1) rotatably arranged in the knee joint and moves the movable plate 1 of the ball screw 68d.
It is connected to 04. The movable plate 104 of the ball screw 68d moves back and forth by a motor. Movable plate 10
When the wire 4 advances or retracts, the wire 66d is pulled in or loosened.

By the above, the following attitude changes are realized. (1) The ball screw 68a is shortened by retracting the ball screw 68a.
Loosen 8c to raise the toe. By loosening the ball screw 68a and contracting the ball screws 68b and 68c, the toes are lowered. (2) The outside of the foot is raised by contracting the ball screw 68b and loosening the ball screw 68c. The inner side rises by loosening the ball screw 68b and contracting the ball screw 68c. (3) The lower leg 16 rotates forward by contracting the ball screws 68a, 68b, 68c and loosening the ball screw 68d. The lower leg 16 rotates backward by loosening the ball screws 68a, 68b, 68c and contracting the ball screw 68d. With the four actuators and the four wires, the rotation angle of the ankle joint 26 around the X axis (the rotation of 2), the rotation angle of the ankle joint 26 around the Y axis (the rotation of 1), and the knee joint 2
The rotation angle around 4 (the rotation of 3) can be adjusted independently.
The actuators appear to be redundant because the four actuators adjust the angle of rotation about the three axes. However, this redundancy can be used to adjust the rigidity related to the rotation angle. This point will be described later.

Not only the knee joint 24 but also the actuator for adjusting the rotation angle of the ankle joint 26 is provided in the thigh portion 14.
Since it is placed at the tip, the tip of this artificial leg is light and the moment of inertia around the hip joint is small. Therefore, a lower limb that can be rotated around the hip joint 22 at high speed with a small torque is obtained.

Next, a wire and an actuator for adjusting the rotation angle around the hip joint 22 will be described. As shown in FIGS. 1 and 2, three arc-shaped wire end guides 48a, 48b, 48c are attached to three positions at predetermined positions on the upper part of the thigh 14, and the wires 50a, 50b, 50c are respectively attached thereto.
Are hung one by one. Each wire 50a,
The lower ends of 50b and 50c are wire end guides 48, respectively.
It is fixed to the lower ends 49a, 49b, 49c of a, 48b, 48c. A pulley 54 is arranged in the middle of the wire 50c attached to the rear side, and the pulley 54 is located rearward of the Y axis of the hip joint 22. Wires 50a, 50
The upper ends of b and 50c are ball screws 52a and 52a, respectively.
It is connected to the movable plates b and 52c. Since each feed screw of the ball screws 52a and 52b is rotated by a motor (not shown), the movable plate screwed onto the feed screw is moved forward and backward by the rotation of the motor. As a result, the effective length of the wires 50a, 50b, 50c expands / contracts. The ball screws 52a, 52b,
52c and the motor 56 and the like for that are arranged in the body, and do not increase the moment of inertia of the lower limbs rotating around the hip joint 22 at all.

The ball screws 52a and 52b are attached to the hip joint 22.
Is located anterior to the Y-axis of the
Rotate 4 forward around the Y-axis of hip joint 22. The pulley 54 that guides the wire 50c is located rearward of the Y axis of the hip joint 22, and when the ball screw 52c contracts, the thigh 14 is rotated rearward around the Y axis of the hip joint 22. It should be noted that the rotatable disc 36 on the pelvis 28 is the motor 3
It is rotated about the Z axis by 8. The motor 38 is fixed to the pelvis portion 28.

The wire connection point 49c is located rearward of the Y axis of the hip joint 22, and when the wire 50c is pulled, the thigh portion 14 rotates rearward about the Y axis of the hip joint 22. The wire connection point 49c is arranged on the X axis of the hip joint 22, and even if the wire 50c is pulled, it does not affect the rotation of the thigh 14 around the X axis. The wire connection point 49a is the hip joint 22.
Is located outside the X axis, and when the wire 50a is pulled, the thigh portion 14 rotates around the X axis of the hip joint 22 to open the thigh portion 14. The wire connection point 49b is located inside the X axis of the hip joint 22, and when the wire 50b is pulled, the thigh portion 14 rotates around the X axis of the hip joint 22 to close the thigh portion 14. When closing the thigh 14, the wire 50b is pulled and at the same time the wire 50a is loosened.
Allows to close. Similarly, when the thigh 14 is opened, the wire 50a is pulled and at the same time the wire 50b is loosened to allow the thigh 14 to open. When rotating the thigh 14 around the X axis of the hip joint 22, the wire 50 is used.
It is not necessary to operate c. When the wires 50a and 50b are pulled at the same time, the thigh portion 14 rotates forward around the Y axis of the hip joint 22 and lifts the thigh portion 14. In this case, the wire 50c is loosened to allow the thigh 14 to rotate forward. When pulling the wire 50c and rotating the thigh 14 backward, at the same time, the wires 50a and 50b are loosened to allow the thigh to descend.

With the above, the hip joint 22 is adjusted as follows. (1) The ball screws 52a, 5
By loosening 2b, the thigh 14 rotates backward. The thigh 14 rotates forward by loosening the ball screw 52c and contracting the ball screws 52a and 52b. A large torque is required to lift the thigh 14 forward, but a large torque is not required to lower it backward. Two actuators and two wires are used on the side where large torque is required, and one actuator and one wire are used on the side where only small force is required. (2) The thigh 14 is lifted outward by contracting the ball screw 52a and loosening the ball screw 52b. The thigh 14 is closed by loosening the ball screw 52a and contracting the ball screw 52b. With three actuators and three wires, the rotation angle of the hip joint 22 about the X axis (the rotation of 2) and the rotation angle of the hip joint 22 about the Y axis (the rotation of 1) can be adjusted independently.

Since the actuator for moving the thigh 14 around the hip joint 22 is arranged on the body side,
When moving the thigh 14, it is not necessary to move each actuator. The moment of inertia around the hip joint 22 is small. Therefore, the lower limbs can be rotated at high speed around the hip joint 22 with a small torque.

The three wires 6 shown clearly in FIG.
A non-linear spring 140 shown in FIGS. 12 and 13 is inserted in an intermediate portion of 6a, 66b and 66c. The spring 140 is made of spring steel, and has a flat plate portion 122, a pair of flanges 126 and 126, and another pair of flanges 130 and 13.
It has 0. A shaft 128 is provided between the flange pairs 126 and 126, and a shaft 132 is provided between the flange pairs 130 and 130. Flat plate portion 122
The ridge 12 extending parallel to the shafts 128 and 132.
4 are formed. The wire 66 bends while bending below the shaft 128, above the ridge portion 124, and above the shaft 13.
It passes under 2. As shown in FIG. 14, when the wire 66 is strongly pulled, the flat plate portion 122 made of spring steel is bent and the wire 66 is stretched.

Since the spring 140 is inserted in the wire, the wire tension can be adjusted by the ball screw. In FIG. 1, the retracted amount of the ball screw 68b and the retracted amount of the ball screw 68c are equal,
8 is adjusted around the X axis at a right angle to the shaft 42 of the lower leg 16. From this state, the ball screw 68b and the ball screw 68c are further drawn at the same speed.
In this case, since the wire 66b and the wire 66c are pulled in at the same speed, the foot portion 18 does not rotate around the X axis. However, as the wires 66b and 66c are retracted, as shown in FIG.
Is deformed, and the tension of the wires 66b and 66c increases. That is, this robot is a system in which one of the two wires is pulled to rotate clockwise and the other wire is pulled to rotate counterclockwise. Therefore, by pulling both wires at the same time, the rotation angle is changed. It is possible to increase only the wire tension without changing the. Similarly, by loosening both wires simultaneously, only the wire tension can be reduced without changing the angle of rotation.

The wire tension determines the rigidity of the rotation angle around the joint. For example, when the foot 18 of FIG. 1 is grounded to the ground, if the tension of both wires is low and the rigidity is low, the grounded ground is high on the left side of the foot and low on the right side of the foot 18
The wire pulling up the right side of the foot 18 extends and the foot portion 18 tilts in accordance with the tilt of the ground, and the foot portion 18 is entirely grounded. If the rigidity is low, it flexibly follows external events. On the other hand, when the foot 18 on one side is in the air, if the tension of both wires for adjusting to the aerial posture is weak and the rigidity is low, a slight external force acts on the robot to extend the wire, and thus the aerial posture is changed. Becomes unstable. In order to stabilize the posture, it is preferable that the rigidity is high. The higher the rigidity,
The movement of the ball screw and the rotation angle around the joint match well, and it is possible to rotate or operate at high speed around the joint.

In the robot of this embodiment, one of the two wires is pulled to rotate it clockwise, and the other wire is pulled to rotate it counterclockwise (pull-pull method).
Moreover, since the non-linear spring is inserted in the middle part of the wire, the rigidity can be adjusted independently of the robot posture. When it is necessary to flexibly follow, sometimes the rigidity is low,
When it is necessary to stabilize the posture, it can be adjusted to a high rigidity.

The reason why the rigidity around the joint can be adjusted by the pull-pull method and the non-linear spring will be described with reference to FIGS. In this description, a simple example in which the foot is rotated around the Y axis by two wires will be described. FIG. 21 schematically shows such a configuration. As shown in FIG. 21, the foot 302 is integrated with a cylindrical pulley 303. The pulley 303 is rotatably supported around the Y axis 303c. The front wire 304 and the rear wire 306 are wound around a pulley 303, and one end of each is connected to the pulley 303 at wire connection points 303a and 303b. The other ends of the front wire 304 and the rear wire 306 are connected to the front actuator 312 and the rear actuator 314, respectively. The front actuator 312 and the rear actuator 314 are fixed members 322, 324.
It is fixed to. The actuators 312 and 314 are
The wires 304 and 306 are pulled in or loosened.
In the middle of the wires 304 and 306, the front nonlinear spring 30
5 and a rear non-linear spring 307 are attached.

FIG. 22 is a graph showing the spring characteristics of the front nonlinear spring 305 and the rear nonlinear spring 307. The vertical axis (y axis) represents the spring force, and the horizontal axis (x axis) represents the amount of spring extension. The curve on the right side of the y-axis is the backward nonlinear spring 3.
07 represents the spring characteristic, and the left side of the y-axis is the front nonlinear spring 3
The spring characteristics of No. 05 are shown. As is clear from FIG. 22, the spring characteristics of the front non-linear spring 305 and the rear non-linear spring 307 have a non-linearity in which the spring force suddenly increases (the inclination of the curve becomes steep) as the expansion increases. . That is, it does not follow Hooke's law. The manner in which the rigidity of the foot 302 around the rotary shaft 303c is adjusted will be specifically described with reference to FIG. For example, springs 305, 30
It is assumed that the actuators 312 and 314 are further retracted by A (mm) from the operation amounts of the actuators 312 and 314 when the extension amount of No. 7 is zero and the angle of the foot portion 302 is adjusted to a predetermined position. Then, the springs 305 and 307 expand and a spring force of B (kg) is generated (see points D and F). The wire tension is adjusted to B (kg). Since the tension on the front wire 304 and the rear wire 306 are equal, the foot 302 does not rotate and maintains the adjusted position. In this state, apply a clockwise moment to the foot 302 to rotate it,
It is assumed that the rear spring 307 extends C (mm) (point D → point E). On the other hand, when the rear spring 307 extends C (mm), the front spring 305 contracts by an amount equal to this (C (mm)) (point F → point G). Therefore, the foot 302 is rotated and the spring (3
05, 307) to expand and contract by C (mm), the force of H (kg), which is the difference in spring force between points E and G, is applied to the pulley 303.
Need to add to.

It is assumed that the actuators 312 and 314 are further retracted by J (mm) (point L, point M). The spring force generated by the springs 305 and 307 at this time is K (kg). Even in this case, the wires 304, 3
Since the tension of 06 is the same, the foot 302 keeps its position without rotating. In this state, it is assumed that a clockwise moment is applied to the foot portion 302 and the rear spring 307 extends C (mm) (point L → point N). The front spring 305 is C (m
m) Shrink (point M → point P). Therefore, in order to rotate the foot portion 302 and expand and contract the springs 307 and 305 by C (mm), it is necessary to apply a force Q (kg), which is the difference between the spring forces at the points N and P, to the pulley 303. .

The actuators 312 and 314 have A (m
m) The spring 30 is pulled from the state of the tension B realized by being pulled in.
The force required to expand and contract 7, 305 C (mm) is H
(Kg). Actuators 312 and 314 are J
The force required to expand and contract the springs 307 and 305 by C (mm) from the state of the tension K that is drawn in (mm) is Q (kg). Obviously Q (kg) is H
Larger than (kg). That is, the actuator 31
2 and 314 are pulled in greatly and a large tension is applied to the wire 3
The foot 302 is generated when it is generated in 04 and 306.
Rigidity (rotational moment around the Y-axis required to rotate the foot 302 by a predetermined angle) is increased. Actuator 31
The rigidity of the foot 302 can be adjusted by changing the amount by which the wires 314 pull in the wires 304 and 306. When the pull-pull method and the non-linear spring are used in combination, the rigidity can be adjusted independently of the rotation angle of the joint.

The inclination angle of the spring characteristic graph of FIG. 22 is proportional to the rigidity. Therefore, it is possible to adjust to the intended rigidity by obtaining the elongation amount of the spring whose inclination angle corresponds to the intended rigidity and giving the elongation amount. Regardless of the posture of the robot, if the length of the perpendicular line drawn from the center of rotation to the wire, that is, the length of the arm for the moment is almost constant, the tension or extension amount can be determined from the rigidity. However, the length of the perpendicular from the center of rotation to the wire,
That is, when the length of the moment arm changes, the length of the moment arm must be taken into consideration before the tension is determined from the rigidity. For example, both have wire tension of 1
It is assumed to be kg. At this time, 1kg from the center of rotation
The length to the point of application of tension is 10 cm (Case 1) and 2
0 cm (case 2). At this time, the case 2 has a longer moment arm and a larger moment. In case 2, the tension is the same, but the degree of maintaining the joint rotation angle at a predetermined value against the external force is stronger. Stiffness is determined by tension and moment arm length. When the rigidity is specified, the second calculation unit of the controller calculates the tension required to adjust the rigidity to the specified rigidity from the specified rigidity and the arm length of the moment at that time, and then calculates the tension. By calculating the length of wire extension required to adjust to the tension, the flexibility around the joint can be adjusted to the specified rigidity without depending on the posture of the robot.

A second embodiment in which the present invention is embodied in a neck joint will be described with reference to FIGS. FIG. 15 is a diagram for explaining the structure of the neck joint of the robot.
FIG. 20 is a diagram for explaining the movement of the head.

FIG. 15 is a deformed view for explaining the structure of the neck joint 80, and does not necessarily match the actual shape and size. The neck joint 80 includes a head portion 82 and a body portion 20.
Is connected to the clavicle portion 84. A cylindrical flange 86 extends downward at the lower part of the head portion 82, and the flange 86 has a shaft hole 86a extending in the Z-axis direction. A short shaft 88 is located below the head 82, and a shaft 90 extends upward above the shaft 88. Flange 8 on head 82
The shaft 90 of the shaft 88 is inserted into the shaft hole 86a of 6,
The head 82 can be rotated about the Z axis by a shaft 88.

At the lower part of the shaft 88, two flanges 92 arranged in parallel in the X-axis direction extend downward. Further, on the upper surface of the clavicle portion 84, two flanges 94 arranged in parallel in the Y-axis direction extend upward. These shafts 8
The flange 92 of No. 8 and the flange 94 of the clavicle portion 84 are connected by a cross type universal joint 96 to form a universal joint, and the shaft 88 mutually reciprocates around the X-axis and the Y-axis with respect to the clavicle portion 84. Independently rotatably connected. That is, the neck joint 80 is rotatably connected to each other independently about the X axis, the Y axis, and the Z axis.
It has degrees of freedom for each of the X, Y, and Z axes.

Between the head portion 82 and the body portion 84, the head portion 82
Four wires 96a, 96b, 96c, 96d are stretched in order to rotate the X-axis around three axes of X, Y, and Z axes. The upper ends of the four wires 96a, 96b, 96c, 96d are guided by four wire end guides (not shown) attached to the lower portion of the head 82, and fixed at the wire connection points 98a, 98b, 98c, 98d. ing.
Elongated holes 84a and 84b are provided on both outer sides of the flange 94 of the clavicle portion 84 in parallel with the flange 94. Clavicle 8
Below the number 4, four pulleys (not shown) are arranged. The wires 96a and 96b pass through the elongated hole 84a and pass downward of the clavicle portion 84, and each of them is wound around another pulley. The wires 96c and 96d pass through the elongated holes 84b and pass out below the clavicle portion 84, and are wound around different pulleys. These wires 96a,
The lower ends of 96b, 96c and 96d are connected to an actuator (not shown), and the effective length of the wire is expanded / contracted by the same mechanism as in the first embodiment. The effective length of the wire may be increased or decreased by rotating the pulley with a motor and winding the wire around the pulley. Wire connection points 98a, 98
Of b, 98c and 98d, 98a and 98b are on the right side of the X axis, and 98c and 98d are on the left side of the X axis. 98
b and 98c are behind the Y axis, and 98a and 98d are on the front side of the Y axis. Wire connection points 98a, 98b, 98c,
98d is distributed on both sides of the X axis and the Y axis.

Next, the movement of the head 82 due to the extension / contraction of the effective length of the wire will be described. 16 to 20 show the head 8
It is a schematic diagram for demonstrating the movement of FIG.
FIG. 18 is a diagram for explaining the rotation around the X axis, and FIG.
19 is a diagram for explaining the rotation around the Y axis, and FIG.
0 is a diagram for explaining the rotation around the Z axis. Figure 1
6, 18 and 20 are plan views of the head 82, FIG. 17 is a rear view of the head 82, and FIG. 19 is a left side view of the head 82. At the ends of the wires 96a, 96b, 96c, 96d, the wire end guide is not shown, and the wire connection point 98
Only a, 98b, 98c and 98d are shown. FIG.
Obviously, the connection points 98 are turned clockwise around the Z-axis.
When looking at a, 98b, 98c and 98d, the wire group applies a clockwise moment at the connection point 98a, a counterclockwise moment at the connection point 98b and a clockwise moment at the connection point 98c. , Connection point 98d
Now add a counterclockwise moment. That is, the wire groups 96a, 96b, 96c, 96d are pulled in a direction in which the moment about the Z axis is alternately inverted.

16 and 17 show wire connection points 98a and 9a.
The case where the effective lengths of the wires 96a and 96b connected to 8b are contracted equally and the effective lengths of the wires 96c and 96d connected to the wire connection points 98c and 98d are equally expanded are shown. At this time, the head 82 rotates in the direction of the arrow around the X axis as shown by the broken line in FIG.
When the extension / contraction of the effective length of the wire is reversed, the head 82 rotates in the direction opposite to the arrow. That is, by adjusting the extension / contraction of the effective wire length in this manner, the head 82 can be freely rotated around the X axis.

18 and 19 show wire connection points 98a and 9a.
It shows a case where the effective lengths of the wires 96a and 96d connected to 8d are equally extended and the effective lengths of the wires 96b and 96c connected to the wire connection points 98b and 98c are equally contracted. At this time, the head 82 rotates in the direction of the arrow around the Y axis as shown by the broken line in FIG.
When the extension / contraction of the effective length of the wire is reversed, the head 82 rotates in the direction opposite to the arrow. That is, by adjusting the extension / contraction of the effective wire length in this manner, the head 82 can be freely rotated around the Y axis.

FIG. 20 shows a wire 96b that extends the effective lengths of the wires 96a and 96c connected to the wire connection points 98a and 98c equally and provides a counterclockwise moment to the wire connection points 98b and 98d. , 96
It shows a case where the effective length of d is contracted equally. At this time, the head 82 rotates counterclockwise around the Z axis as shown by the broken line in FIG. When the extension / contraction of the effective length of the wire is reversed, the head 82 rotates clockwise. That is, by adjusting the extension / contraction of the wire effective length in this manner, the head 82 can be freely rotated around the Z axis.

Although not shown, the head 82 can be moved as follows. As shown in FIG. 20, the effective lengths of the wires 96a and 96c are extended to change the wires 96b and 9c.
When the effective length of 6d is contracted, the extension amount of the wire 96a and the contraction amount of the wire 96d are reduced by the same amount.
increase the amount of expansion of c and the amount of contraction of the wire 96b,
If the amount of increase / decrease in the amount of extension / contraction is equal, the head rotates leftward around the Z axis in the direction of the arrow, and
As shown in FIG. 17, the left side is raised by rotating in the direction of the arrow around the X axis. Further, the amount of extension of the wire 96a and the amount of contraction of the wire 96b are equally increased, and the amount of extension of the wire 96c and the amount of contraction of the wire 96d are equally reduced.
When the contraction amount increases / decreases by the same amount, as shown in FIG. 19, the front side also rises by rotating in the direction of the arrow around the Y axis. That is, when the extension / contraction of the effective wire length is adjusted in this manner, the head 8
2 can be freely rotated about the X axis, the Y axis, and the Z axis. By using four wires for the three axes of X, Y, and Z, that is, the number of wires plus one wire, it is possible to adjust the rotation angle independently of each other for the X, Y, and Z axes.

Since the robot of the present invention is wire-driven, it is not necessary to mount an actuator on each joint. Since the actuator can be mounted at a position away from the joint, the joint can be made smaller and lighter, and the degree of freedom in the mounting position of the actuator is increased. In the case of the present invention, the number of wires may be three for biaxial joints and four for triaxial joints, that is, the number of axes may be +1 for one joint. Since the number of wires and the number of actuators required are reduced, slimming and weight reduction of limbs can be achieved. Because of these, the required power can be reduced, the movement of the distal end member can be accelerated, and a robot similar in appearance and movement to humans and animals can be realized. It will be possible.

Specific examples of the present invention have been described above in detail, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. Further, the technical elements described in the present specification or the drawings are
The technical usefulness is exhibited alone or in various combinations, and is not limited to the combinations described in the claims at the time of filing. In addition, the technique illustrated in the present specification or the drawings achieves a plurality of purposes at the same time, and achieving the one purpose among them has technical utility.

Therefore, for example, it can be configured as described below. (1) The actuator group is not limited to being placed on the thigh. For example, a group of actuators may be arranged on the upper arm of the upper limb, and the individual actuators may be operated to rotate the forearm with respect to the upper arm or rotate the hand with respect to the forearm.

(2) Although the rotation angle and the tension of the joint are input to the controller of the ball screw described above, the rigidity of the joint may be input instead of the tension. In such a configuration, the controller calculates the moment arm between the center of rotation of the distal member (eg, foot) and the connection point of the wire from the angle of rotation of the joint, and from this moment arm, the joint obtains the desired stiffness. Calculate the wire tension. Then, the operation amount of the ball screw with the calculated tension of the wire is output to the ball screw. In the configuration in which the moment arm changes significantly with the rotation of the distal end member (the configuration in which there is no wire end guide), the stiffness is input to the controller instead of the tension as described above, and this is calculated. Thus, the rigidity of the joint can be controlled more accurately.

[Brief description of drawings]

FIG. 1 is a front view of both lower limbs of the robot of this embodiment.

FIG. 2 is a side view of the left lower limb of the robot.

FIG. 3 is a diagram for explaining a structure of an ankle joint of the robot.

FIG. 4 is a diagram illustrating details of a ball screw of the robot.

FIG. 5 is a diagram illustrating movement of a foot of the robot.

FIG. 6 is a diagram illustrating movement of a foot of the robot.

FIG. 7 is a diagram illustrating movement of a foot of the robot.

FIG. 8 is a diagram illustrating movement of a foot of the robot.

FIG. 9 is a diagram illustrating movement of a foot of the robot.

FIG. 10 is a diagram for explaining the movement of the foot of the robot.

FIG. 11 is a diagram for explaining the movement of the foot of a conventional wire-driven robot.

FIG. 12 is a diagram for explaining the movement of the legs of the robot of this embodiment.

FIG. 13 is a diagram for explaining the movement of the foot of the robot.

FIG. 14 is a diagram illustrating movement of a foot of the robot.

FIG. 15 is a view for explaining the structure of the neck joint of the robot of this embodiment.

FIG. 16 is a diagram illustrating the movement of the head of the robot.

FIG. 17 is a diagram illustrating the movement of the head of the robot.

FIG. 18 is a diagram for explaining the movement of the head of the robot.

FIG. 19 is a diagram illustrating the movement of the head of the robot.

FIG. 20 is a diagram illustrating the movement of the head of the robot.

FIG. 21 is a diagram illustrating rigidity of joints of the robot.

FIG. 22 is a graph for explaining the joint rigidity of the robot.

[Explanation of symbols]

10: Robot 12: Lower limb 14: Thigh 16: Lower thigh 18: Foot 20: Body 22: Hip joint 24: Knee joint 26: Ankle joint 28: Pelvis 30: Shaft 32: Universal joint 34: Bearing 36: Disc 38: Actuator 40: Flange 42: Shaft 44: Flange 46: Shafts 48a, 48b, 48c: Wire end guides 49a, 49b, 49c: Wire connection points 50a, 50b, 50c: Wires 52a, 52b, 52c: Ball screw 54: Pulley 56: Actuator 58: Flange 60: Flange 62: Cross type universal joint 64a, 64b, 64c, 64d: Pulley 66a, 66b, 66c, 66d: Wire 68a, 68b, 68c, 68d: Ball screw 70a, 70b, 70c: Wire end guides 72a, 72b, 72c: Wye Connection point 80: Neck joint 82: Head portion 84: Clavicle portion 84a, 84b: Elongated hole 86: Flange 86a: Shaft hole 88: Shaft 90: Shaft 92: Flange 94: Flange 96a, 96b, 96c, 96d: Wire 98a, 98b, 98c, 98d: Wire connection point 102: Flange 104: Movable plate 106: Flange 108: Guide rod 110: Guide rod 112: Guide rod 114: Motor 116: Gear 118: Gear 120: Feed screw 122: Flat plate portion 124: Peak 126: Flange 128: Shaft 130: Flange 132: Shaft 302: Foot 303: Pulley, 303a: Wire connection point, 303b:
Wire connection point, 303c: Y-axis 304: Front wire 305: Front spring 306: Rear wire 307: Rear spring 312: Front actuator 314: Rear actuator 322, 324: Fixing member

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hirochika Inoue             7-3-1, Hongo, Bunkyo-ku, Tokyo Tokyo University             On campus (72) Inventor Masao Kawase             1 Toyota Town, Toyota City, Aichi Prefecture Toyota Auto             Car Co., Ltd. (72) Inventor Yuji Tsusaka             Aichi Prefecture Nagachite Town Aichi District             Ground 1 Toyota Central Research Institute Co., Ltd. F-term (reference) 2C150 BA08 CA01 CA02 CA04 DA04                       DA05 DA24 DA26 DA27 DA28                       EB01 EC03 EC15 EC25 EC29                       ED10 ED39 ED42 ED52 EF07                       EF09 EF16 EF17 EF22 EF23                       EF33 EF36                 3C007 CU07 CX00 CY00 HS27 HT04                       HT20 HT21 HT36

Claims (7)

[Claims] 1. A body side member, a terminal side member rotatably connected to the body side member, and at least two end parts attached to both sides of the center of rotation of the terminal side member. A wire and at least two actuators connected to the other end of each wire to expand and contract each wire;
A controller for controlling this actuator group is provided, and the controller inputs the information about the rotation angle of the distal end member and the information about the tension applied to the wire, and outputs the operation amount of each actuator. robot. 2. The controller calculates a wire length from information on a rotation angle of the distal end member, and a second calculation unit calculates a wire extension length from information on tension.
The robot according to claim 1, further comprising: a calculation unit and a third calculation unit that calculates an actuation amount of the actuator from the calculation results of both calculation units. 3. A body side member, a terminal side member rotatably connected to the body side member, and at least two end parts attached to both sides of the center of rotation of the terminal side member. A wire and at least two actuators connected to the other end of each wire to expand and contract each wire;
A controller for controlling this actuator group is provided, and the controller inputs the information about the rotation angle of the distal side member and the information about the rigidity for maintaining the distal side member at the rotational angle, and operates the actuator operation amount. A robot characterized by outputting. 4. The controller calculates a wire length from information on a rotation angle of the distal end member, and a second calculation unit calculates a wire extension length from information on rigidity.
4. The robot according to claim 3, further comprising a calculation unit and a third calculation unit that calculates the actuation amount of the actuator from the calculation results of both calculation units. 5. The robot according to claim 1, wherein a non-linear spring is inserted in each wire. 6. The robot according to claim 1, wherein the body side member is a lower leg and the terminal side member is a foot. 7. The robot according to claim 6, wherein a high rigidity is instructed when the foot portion should be in the air, and a low rigidity is instructed during the ground contact.