JPH0544073Y2 - - Google Patents

Description

[Detailed Description of the Invention] A. Field of Industrial Application The present invention relates to the structure of the shoulder joint of a master-slave manipulator.

B. Summary of the invention The invention provides a shoulder joint of a manipulator that connects the upper arm of an arm, which is equipped with a forearm that can freely bend in a horizontal plane when the upper arm is in a horizontal state, to the shoulder member. At the same time, the upper arm is attached to the connecting piece so as to be rotatable about the shoulder joint axis of the first shoulder joint, and the upper arm is rotatable about the second shoulder joint axis that is approximately perpendicular to the first shoulder joint axis, and the longitudinal axis of the upper arm is rotatable about the second shoulder joint axis. By attaching it at an angle with respect to the joint axis, it is possible to improve workability in the arm posture where the elbow is stretched, which is the most typical posture during work.

C. Prior Art One type of power manipulator device is a master-slave manipulator. The master-slave manipulator has a structure in which when a worker operates the master arm, the slave arm operates in response to the movement of the master arm. In this master-slave manipulator, the joints of the slave arms are often arranged in a positional relationship similar to that of human joints. By making the slave arm similar in shape to a human arm in this way, the operator can intuitively operate the manipulator as if the slave arm were his own arm.

D Problems to be solved by the invention By the way, when a person works, as shown in Fig. 2, the elbow 11 is stretched out to the side, that is, the upper arm
4 is in a horizontal state, most often takes a basic posture in which the forearm 13 is bent in the horizontal plane and the elbow 11 is stretched out to the side. In FIG. 2, 12 represents the hand, 15 represents the shoulder, and θ represents the bending angle of the elbow 11. Therefore, it is desirable to be able to easily move the hand 12 up and down and left and right around the shoulder joint by rotating the shoulder joint from this basic posture with the elbow 11 stretched out to the side.

However, in the shoulder joint of conventional manipulators, when the upper arm is bent and tilted with respect to the shoulder joint in a state corresponding to the elbow-to-side arm posture described above, when swinging the arm up and down, multiple joint axes must be controlled simultaneously. However, there was a problem in that the arm swayed in the lateral direction due to discrepancies in speed control of multiple axes. Therefore, it has been difficult to handle mechanisms that move straight in the vertical direction, which are often used in mechanical devices.

The present invention is intended to solve these problems, and is a manipulator that can move the arm up and down and in the left and right directions by controlling a single axis in the arm posture where the elbow is stretched, which is often used during work. The purpose is to provide shoulder joints.

E. Means for Solving the Problems The shoulder joint of the manipulator according to the present invention that solves the above-mentioned problems has a forearm that can be bent freely in a horizontal plane when the upper arm is in a horizontal state. , in the shoulder joint of the manipulator connected to the shoulder member, a connecting piece is attached to the shoulder member so as to be rotatable around the first shoulder joint axis, and the upper arm is attached to the connecting piece so as to be rotatable around the first shoulder joint axis. It is characterized in that it is mounted so as to be rotatable about a second shoulder joint axis forming a substantially right angle and with its longitudinal axis inclined with respect to the second shoulder joint axis.

F Action Directs the first shoulder joint axis in the vertical direction and
With the shoulder joint axis oriented in the left-right direction, an arm posture is taken in which the upper arm is tilted in the front-back direction and the elbow is stretched out to the side. In this state, if the connecting piece is driven around the first shoulder joint axis, the hand will be swung left and right, while if the upper arm is driven around the second shoulder joint axis, the hand will be swung up and down.

G. Example Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a partially cutaway plan view of a robot arm according to an embodiment of the present invention. As shown in FIG. 1, an upper arm 23 is connected to a shoulder member 21 corresponding to a human shoulder 15 via a shoulder joint 22.
A forearm 25 is connected to the tip of the arm 3 via an elbow joint 24, and a hand 26 is attached to the tip of the forearm 25. The forearm 25 can bend freely in a horizontal plane when the upper arm 23 is in a horizontal state, and the upper arm 23 and the forearm 25
The arms are made up of. At the shoulder joint 22,
A connecting piece 28 is connected to the shoulder member 21 by a first shoulder joint axis 27 extending in the vertical direction so as to be rotatable in a horizontal plane (in a plane parallel to the plane of the paper). It is designed to be rotationally driven by a drive motor 30 with a reduction gear via a gear 29. This connecting piece 28 also has a second
A shoulder joint shaft 31 is fixed, and the upper arm 23 is attached to the second shoulder joint shaft 31 so as to be rotatable about the second shoulder joint shaft 31. Here, the upper arm 23 is connected with its longitudinal axis inclined at an angle β of approximately 45 degrees with respect to the axis of the second shoulder joint shaft 29. A bevel gear 32 is fixed to the second shoulder joint shaft 31, and a drive bevel gear 34 of a drive motor 33 with a reduction gear provided in the upper arm 23 is meshed with this bevel gear 32. 33 causes the upper arm 23 to rotate around the second shoulder joint axis 31. Note that the drive system for the shoulder joint 22 is not limited to the above-mentioned gear mechanism, and other drive devices may be used.

By the way, in order to approximate the shoulder joint of a person, it is preferable that the first shoulder joint axis 27 and the second shoulder joint axis 31 intersect, but in that case, the gear mechanism becomes complicated and it becomes troublesome to remove the backlash. . On the other hand, in this embodiment, the axes 27 and 31 do not intersect, but by setting the distance E between the axes 27 and 31 as small as possible, the axes 27 and 31 do not intersect. Not only does it not cause any major problems as a shoulder joint, but it also has the advantage of simplifying the structure. However, in the present invention, both axes 27 and 31 may be configured to intersect. Furthermore, in order to enable spherical bearing motion similar to the human shoulder joint, it is necessary to
What is necessary is to add a joint whose operating axis is the axis.

With this configuration, in the arm posture with the elbow stretched out to the side as shown in Fig. 1, the upper arm 23 is
When the angle formed by the longitudinal axis of the The joint axis 31 forms a right angle. In this state, if the connecting piece 28 is driven around the first shoulder joint axis 27, the hand 26 is swung left and right, while
When the upper arm 23 is driven around the second shoulder joint axis 31, the hand 26 is swung up and down, and these movements in the left-right and up-down directions can be performed independently by controlling each axis. Therefore, when the hand 26 moves up and down due to the operation of the second shoulder joint shaft 31, no lateral wobbling occurs.

The angle α between the Y-Y axis and the longitudinal axis of the upper arm 23,
The angle β between the longitudinal axis of the upper arm 23 and the second shoulder joint axis 31 is appropriately determined to be around 45 degrees (approximately ±50%) depending on the type of manipulator and the typical arm posture. It is something that Here, α+
If β is not 90 degrees, the hand 26 will swing sideways due to the operation of the second shoulder joint axis 31, but as in the conventional case, the upper arm 23
Compared to those mounted perpendicularly to the axis corresponding to (β = 90 degrees), lateral vibration is extremely reduced and can be kept within a practically allowable range.

In the illustrated example, the arm posture was described with the elbow stretched out to the side, but as mentioned above, by providing a joint with the Y-Y axis as the operating axis, the shoulder member can be moved around the Y-Y axis from the state shown in Figure 1. If you rotate 21 by ±90 degrees, the arm posture will be the same as when the elbow is up or down,
In these cases, it is also possible to swing the hand 26 vertically and horizontally by controlling a single axis.

H. Effects of the Device As specifically explained above with reference to one embodiment, according to the present invention, the longitudinal axis of the upper arm is inclined with respect to the second shoulder joint axis, which is the axis of rotation of the upper arm. , in the arm posture often used during work, where the upper arm is tilted and the elbow is stretched out to the side, the vertical and horizontal movements of the arm can be performed by controlling each axis independently, simplifying the control and improving the work. Accuracy can be improved.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway plan view of a robot arm according to an embodiment of the present invention, and FIG. 2 is a plan view of a human arm showing a typical arm posture during work. In the drawings, 21 is a shoulder member, 22 is a shoulder joint, 23 is an upper arm, 27 is a first shoulder joint axis, and 31 is a second shoulder joint axis.

Claims (1)

[Scope of utility model registration request] In a shoulder joint of a manipulator that connects the upper arm of an arm having a forearm that can freely bend in a horizontal plane when the upper arm is in a horizontal state to a shoulder member, a connecting piece to the shoulder member is arranged around a first shoulder joint axis. The upper arm is rotatably attached to the connecting piece about a second shoulder joint axis that is substantially perpendicular to the first shoulder joint axis, and the longitudinal axis of the upper arm is rotatably attached to the second shoulder joint axis. A shoulder joint of a manipulator, characterized in that it is mounted in an inclined state with respect to a joint axis.