JPH089150B2 - Manipulator - Google Patents

Description

Description: [Object of the Invention] (Field of Industrial Application) The present invention relates to a manipulator having a plurality of hinges, and more particularly to a manipulator to which a hinge for absorbing vibration is added.

(Prior Art) In recent years, manipulators including industrial robots have dramatically spread and are used in various fields. Most of this type of manipulator has a cantilever structure,
Even a slight disturbance causes vibration of the arm, which affects the operation performance. That is, the work is often performed at the tip of the cantilever, and this portion is affected by the vibration of each arm and the error of the hinge angle accumulated, so that the operation performance is significantly deteriorated.

For this reason, in designing the manipulator, a method of increasing the rigidity of each part is often adopted, but this increases the weight of the manipulator. Moreover, weight reduction is a very important issue, especially considering the future application of manipulators to space development, and it is expected that weight reduction will be achieved even if elastic deformation is allowed. Therefore, it is necessary to fully consider the problem of vibration suppression.

By the way, in the conventional hinge arrangement method of the manipulator, the manipulator is regarded as a rigid body, and a hinge for deciding the position of the tip is arranged first, and then a hinge for deciding the posture of the tip is arranged in most cases. Therefore, if necessary, a redundant system was added so that the position and posture on the way could be changed arbitrarily.

This will be described with reference to FIG. FIG. 3 shows one arrangement example of each hinge of the rigid body manipulator. In the figure, 1 to 6 are hinges, 7 and 8 are arms, and 9 is a hand. The manipulator is a hand 9 attached to the tip.
In order to improve the workability of the manipulator, it is necessary to take the hand 9 to any point in space and take an arbitrary posture there.

At least three degrees of freedom are required to bring the tip of the manipulator to any position on the three-dimensional space, so the position is determined with the first three degrees of freedom counting from the root. At this time, in order to make the reachable area as wide as possible, the hinge 1 having the rotation axis is placed first in the longitudinal direction of the arm. After that, the hinges 2 and 3 having the rotation axis in the direction perpendicular to the plane of the drawing are arranged at the second and third positions so that arbitrary positioning can be performed within the plane including the hinge 1.

Now that the hand 9 has been positioned, it is necessary to determine the posture next, but three more degrees of freedom are required to arbitrarily take the posture. Therefore, by arranging the hinges 4, 5 and 6, it has 6 degrees of freedom as a whole, and the position and posture of the hand 9 can be determined.

However, this arrangement is effective only for the manipulator as a rigid body, and the manipulator as a flexible structure has the following problems. That is, in the manipulator as a flexible structure, the arm 7,
Bending vibration, torsional vibration, and the like are generated in the arm 8. For example, when the arm 7 is torsionally vibrated, the hand 9 vibrates with the axial direction of the arm 7 as a rotation axis. In this case, it is very difficult to determine the posture of the vibration with respect to the movement direction, and there is a problem that the positioning performance of the manipulator is deteriorated.

(Problems to be Solved by the Invention) As described above, in the conventional manipulator, when it is attempted to reduce the weight of the entire manipulator, bending vibration, torsional vibration, or the like occurs in the arm. Then, when these vibrations occur, it becomes difficult to control the position and orientation quickly and accurately, and the positioning performance deteriorates.

The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a manipulator capable of suppressing vibrations generated in an arm and improving positioning performance.

[Structure of the Invention] (Means for Solving Problems) The present invention relates to a manipulator in which a plurality of arms are connected by a hinge and which constitutes a space link mechanism as a whole, in a space at any point of the arms. In addition to a positioning hinge arranged to determine the position and orientation of the arm, a vibration absorbing hinge that is rotatable in the same direction as the vibration direction generated in the arm in order to absorb the vibration generated in the arm It is arranged on the base end side of the arm.

The method for arranging the hinge according to the present invention is as follows. First, the structure is considered to be a rigid body, and as many positioning hinges as necessary are arranged at necessary positions so that any point of the structure can have a desired position and posture. If attention is paid only to the position and posture determination of the tip of the structure, six positioning hinges are arranged, and if the posture of the entire structure is taken into consideration, the number of positioning hinges is increased by the required number.

After the hinge arrangement for the structure as a rigid body is completed, a vibration absorbing hinge that is movable in a direction in which each member of the structure is deformed by the vibration generated in the structure is arranged at an appropriate position of each member. By doing so, the position and orientation with respect to the tip of the structure or the entire space can be freely determined by the positioning hinge. Further, the vibration generated in the structure can be suppressed by providing the vibration absorbing hinge with a damper function. However, depending on the direction of vibration, it is possible to substitute the positioning hinge for suppressing the vibration.

(Operation) With the above configuration, the vibration generated in any arm can be suppressed by the vibration absorbing hinge corresponding to the vibration direction. Therefore, each arm can be positioned quickly and accurately. Furthermore, since the vibration absorbing hinge can serve as a redundant system when determining the posture, it is possible to improve the positioning function.

(Examples) The details of the present invention will be described below with reference to illustrated examples.

FIG. 1 is a schematic configuration diagram showing a manipulator according to an embodiment of the present invention. 1, 1 to 6 are positioning hinges, 7 and 8 are arms, 9 is a hand, and 10 to 13 are vibration absorbing hinges.

In order to make an accurate hinge arrangement for the manipulator as a flexible structure, the hinge arrangement as a rigid manipulator is first performed. Since the manipulator works with the hand 9 attached to the tip, it is necessary to take the hand 9 to any point in space and take an arbitrary posture there in order to improve the workability of the manipulator. Therefore, the positioning hinges 1 to 6 are arranged to determine the position and orientation of the hand 9 of the manipulator. Of these, the hinges 1 to 3 are for position determination, and the hinges 4 to 6 are for attitude determination at that point.

Now that the hinge arrangement as a rigid manipulator has been completed, the hinges necessary for vibration suppression are next arranged.
Here, the vibration generated in the arms 7 and 8 will be considered. The components of the generated vibration direction are bending vibration in a plane parallel to the paper surface and perpendicular to the paper surface, and torsional vibration of the arm. Of these, the bending vibrations in the paper can be suppressed by the positioning hinges 2 and 3, so that the vibration absorbing hinges 10 and 12 are newly arranged for other bending vibrations (bending vibrations in a plane perpendicular to the paper). . Further, for torsional vibration, vibration absorbing hinges 11 and 13 are arranged.

The vibration absorbing hinges 10 and 11 are arranged on the base end side of the arm 7, and the vibration absorbing hinges 12 and 13 are arranged on the base end side of the arm 8. Also, these hinges 10, ~, 13
A drive control system is connected to each hinge, and each hinge is driven by an actuator or the like according to the amount of vibration to be canceled.

Here, the drive control system of the hinge 11 is composed of displacement gauges 21a and 21b, a vibration detector 22, an amplifier 23, an actuator 24, etc., as shown in FIG. 2, for example. Displacement meter 21a, 21
b is disposed on the base end side and the tip end side of the arm 7, and detects the displacement amount of the arm 7 around the axis. Displacement meter 21a, 21
Each detection output of b is supplied to the vibration detector 22. The vibration detector 22 detects the torsional vibration of the arm 7 by taking the difference between the detection outputs. A signal corresponding to the detected torsional vibration is amplified by the amplifier 23 and then supplied to the actuator 24. Then, the hinge 24 is driven by the actuator 24. That is, according to the torsional vibration of the arm 7, the hinge 11 is driven so as to cancel it, whereby the torsional vibration is suppressed. In addition, the drive control system for other hinges also has a displacement gauge,
It is composed of a vibration detector and an actuator.

With such a configuration, the arms 7 and 8 can be moved in arbitrary directions by the actions of the positioning hinges 1 to 6, and the hand 9 can be positioned at a predetermined position and the posture of the hand 9 is determined. be able to. Then, when bending vibration, torsional vibration, or the like occurs in the arms 7 and 8, the deformation of the arms due to this vibration can be canceled by the action of the vibration absorbing hinges 10 to 13. For this reason, even a manipulator as a flexible structure that is light in weight can suppress the vibration generated in the arm, and can improve the positioning performance. Further, since the hinge for absorbing vibration can be a redundant system when determining the posture, it is also possible to improve the positioning function of the manipulator.

It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be carried out without departing from the scope of the invention. For example, an arrangement example of the positioning and vibration absorbing hinges is It is not limited in any way to FIG. 1 and can be appropriately changed according to the specifications. Further, the vibration absorbing hinge is not limited to the one provided with a drive system such as an actuator, but may be a mechanical hinge having a damper function.

[Effects of the Invention] As described in detail above, according to the present invention, by arranging a hinge for vibration absorption in addition to a hinge for positioning, it is possible to suppress the vibration generated in the arm,
The positioning performance can be improved.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a manipulator according to an embodiment of the present invention, and FIG. 2 is a block diagram showing an example of a drive control system of a vibration absorbing hinge in the manipulator.
FIG. 3 is a schematic configuration diagram showing a conventional manipulator. 1, ~, 6 ... Positioning hinges, 7, 8 ... Arms, 9 ... Hands, 10, ..., 13 ... Vibration absorption hinges, 21a, 21b ... Displacement gauges, 2
2 ... Vibration detector, 23 ... Amplifier, 24 ... Actuator.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Mr. Komatsu, No. 1, Komukai Toshiba-cho, Sachi-ku, Kawasaki City, Kanagawa Prefecture, Toshiba Research Institute Co., Ltd. (56) References JP-A-52-101569 (JP, A) Kai 61-136792 (JP, A)

Claims (2)

[Claims] 1. A manipulator which comprises a plurality of arms connected by a hinge and constitutes a space link mechanism as a whole, and a positioning hinge arranged to determine the position and posture of any point of the arm in space. In addition, in order to absorb the vibration generated in the arm, a vibration absorbing hinge rotatable in the same direction as the vibration direction generated in the arm is arranged on the base end side of the arm. And manipulator. 2. The manipulator according to claim 1, wherein the vibration absorbing hinge is driven according to a detection output of a vibration detector that detects a vibration of an arm in which the hinge is arranged. .