JPH0129669B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an operating range limiting device that can preferably recognize the operating range during a teaching operation in a master robot.

In so-called master-slave type robots, if an operator uses the master robot to give a command to the slave robot that exceeds the slave robot's operating range, excessive force will be applied to the drive unit, so this can be prevented. To this end, the following measures have been taken in the past.

That is: (a) By providing a stopper on the master robot, the operating range of the master robot is mechanically limited to the operating range of the slave robot.

(b) The commands from the master robot are electrically controlled by a control device so that commands that exceed the operating range of the slave robots are not given to the slave robots.

However, in the former case, a sudden change in the command signal is given to the slave robot near the operating limit of the master robot, which disturbs the smooth operation of the slave robot. There exists a so-called dead area of the slave robot in which the operation of the slave robot does not correspond to signals from the slave robot, which hinders teaching work. Moreover, both have the disadvantage that it is difficult to predict the work since the operator cannot intuitively know the operating range of the slave robot.

SUMMARY OF THE INVENTION An object of the present invention is to provide an operating range limiting device that can eliminate the drawbacks of the conventional devices described above and that can preferably recognize the operating range during teaching operations in a master robot.

According to the present invention, when operating a teaching handle provided on an arm member of a master robot, the object is to control the respective operating ranges of the arm member and the support member mounted on the base and provided with the arm member. A small first operating resistance force that is zero or almost constant is generated from to near the operating limit, and is larger than the first operating resistance force from near the operating limit of each member to the operating limit. By means of a master robot operation range limiting device comprising an operation resistance force generating means provided between the members to generate a second operation resistance force that increases rapidly as the operating limit is approached. achieved.

This will be explained below based on a specific example.

In FIG. 1, a box 1 includes a bearing for receiving the horizontal rotation shaft 2 of the columns 8 and 9, a rotation angle detector for the rotation shaft 2, and a stopper for stopping the horizontal rotation of the columns 8 and 9 as support members. A rotating base 3 is attached to the box 1 via a rotating shaft 2.

The pivot base 3 has fixed shafts 4 and 5 for rotating the columns 8 and 9 back and forth, and two column springs 6 are provided on both sides of the column 9. This spring 6 is in the form of a compression spring, provided with an end turn, and has a flat tip. Pillars 8 and 9 are rotatably mounted on the shafts 4 and 5 of this swing base 3 via bearings, respectively, and the pillars are rotated by a gear fixed to the swing base 3 and a potentiometer fixed to the pillar 9. Angle detector 7
is formed.

An arm rotation angle detector 12 is attached to the columns 8 and 9 via shafts 10 and 11. This axis 10
is to move the pillars 8 and 9 back and forth, and the rotation angle detector 1
2 to allow the pillar 8 to rotate freely around it, while the shaft 11 is fixed to the arm 15.
It is fixed to the rotation angle detector 12 so that the column 9 and the arm 15 can be rotated freely around the rotation angle detector 12. Spring mounting plates 13, 13 are provided extending diagonally upward and downward from the rotation angle detector 12, and arms 15 are attached to these mounting plates 13, 13, respectively.
Spring 14, 14 for use is attached. This spring 14 is provided with an end turn at its tip and has a flat shape.

A gear wheel including the shafts 10, 11 and the mounting plate 13, and a potentiometer fixed to the arm 15 constitute an arm rotation angle detector.

The arm 15 freely rotates around the shaft 11 and has a wrist portion H at its tip. This wrist portion H rotates around a shaft 18 and moves up and down, and also freely rotates around a shaft 19 fixed to a handle 20 in the horizontal direction. The horizontal rotation angle of the wrist H is detected by a horizontal rotation angle detector 16 consisting of a gear fixed to a shaft 19 and a potentiometer fixed to the wrist H, and the vertical rotation angle is , a vertical rotation angle detector 1 consisting of a gear fixed to a shaft 18 and a potentiometer fixed to an arm 15.
7.

The above configuration is the same as the conventional configuration except that the springs 6 and 14 are provided, and the master slave robot rotates the column 9 in the horizontal direction by the five rotating shafts 2, 4, 11, 18 and 19. It has five degrees of freedom: the longitudinal rotation of the column, the vertical rotation of the arm 15, the vertical rotation of the wrist H, and the horizontal rotation of the wrist H, and each rotation angle is a rotation within box 1. Detection is performed by a total of five rotation angle detectors: an angle detector and rotation angle detectors 7, 12, 17, and 16. By means of the springs 6, 14 and the springs described below, the means for recognizing the operating limits of the slave robot, that is, when operating the teaching handle 20, the first zero value is zero from the operating range of each member to near the operating limits. Generates operational resistance,
An operating resistance that generates a second operating resistance force that is greater than the first operating resistance force from near the operating limit of each member to the operating limit, and increases rapidly from near the operating limit to the operating limit. It constitutes a force generating means.

As shown in detail in FIG. 2, the spring 6 is attached to the pivot base 3 as described above as a stopper for the front and rear of the column 9. As shown in FIG. 4, when the column 9 is at a position α far away from the limit α ₁ of the operating range, the spring 6 and the column 9 do not come into contact, and therefore the spring 6 exerts zero operation resistance. Only a predetermined operating force F ₀ is required to operate the column before and after the column 9 is generated, but the column 9 is near the limit of the operating range, that is, α in the figure.
When = α ₀ is reached, the spring 6 and the column 9 come into contact, and in order to get closer to the operating limit α = α ₁ , an additional operating force equal to the reaction force of the spring 6 is required, and the magnitude of this operating force is The operating limit is α = α ₁ maximum F ₁ .

In this manner, the operator operating the master robot senses the operating limit due to the reaction force of the spring 6, and can prevent a sudden change in the operation of the master robot at the operating limit point. spring 14
is used to recognize the operating limit range of the arm 15, and its operation is the same as that of the spring 6.

Shown in FIG. 3 are springs 27, 27 that allow recognition of the range of operating rotation angles of the pivot base 3, which essentially constitutes the strut member. That is, spring mounting plates 26, 26 are provided protruding from the box 1 on both sides of the swing base 3, and a spring 27 is attached to the spring mounting plates 26.

This spring 27 also acts in the same manner as the spring 6, and allows the user to recognize the operating limit of rotation of the swing base 3.

If a similar configuration is used to limit the operating range of other degrees of freedom, the operating limits of the five degrees of freedom of the master robot can be fully recognized as changes in the resistance force.

In this case, the operating range can be easily changed by changing the contact height of the stopper spring, and the strength of the reaction force can also be easily changed by changing the spring constant.

5 to 7 show another means for recognizing the operating limit, that is, when operating the teaching handle 20, a small first operating resistance force is generated that is almost constant from the operating range of each member to near the operating limit, An operating resistance that generates a second operating resistance force that is greater than the first operating resistance force from near the operating limit of each member to the operating limit, and increases rapidly from near the operating limit to the operating limit. This is an example of force generating means. That is, a groove-shaped spring receiving plate 22 is fixed to the column 9, and one end of the spring 21 having the shaft 28 at the center is attached to the column 9, and the other end to the pivot base 25. The same applies to the spring receiving plate 23, shaft 29, and spring 24 provided on the arm 15. One end of the spring 24 is fixed to the arm 15, and the other end is fixed to the rotation angle detector 12, respectively. The rest of the configuration is the same as the previous example. For example, when the column 9 moves back and forth, the positional relationship between the spring 21 and the column 9 changes, so by restraining this change with the spring receiving plate 22 attached to the column 9, the reaction force by the spring 21 increases as the rotation angle increases. A relationship similar to that shown in FIG. 4 is obtained in which the resistance of the master robot increases. In other words, when the positional change between the spring 21 and the column 9 is not restrained by the spring receiving plate 22, the spring 21 generates a small, almost constant operating resistance force, and the positional change is restrained by the spring receiving plate 22. When this happens, a rapidly increasing resistance force is generated. At this time, the operating range can be changed by changing the mounting position of the spring receiving plate 22 or the width B shown in FIG. 6.

According to this specific example, (i) sudden changes in commands are not applied to the slave robot, and smooth operation of the slave robot is possible.

(ii) The operator can sense the operating range of the slave robot based on the spring reaction force, that is, the resistance force.

(iii) The operating range can be easily changed by replacing the spring with another spring having a different spring constant or length.

(iv) Objectives can be achieved more cheaply than electrical control, etc.

(v) When applied to a master robot, during the operation of the teaching handle within the operating range of each member, only a small first operating resistance force of zero or a constant value is received from the operating resistance force generating means; It is possible to reduce situations in which the force applied to the teaching handle must be adjusted in various ways when setting each teaching position, it is possible to perform teaching at a predetermined position smoothly, and the teaching work can be performed in a short time without difficulty. Therefore, it is possible to prevent sudden changes in commands from being applied to the slave robot, and to enable smooth operation of the slave robot.

From the above, according to the master robot operating range limiting device of the present invention, since the operating resistance force generating means configured as described above is provided between each member, teaching near the operating limit between each member is prevented. In this operation, the second operating resistance force is greater than the first operating resistance force and increases rapidly as the operating limit approaches the operating limit.
A worker can reliably intuitively recognize the operating range of an industrial robot. In addition, by adjusting the second actuation resistance, i.e. when using a spring to obtain the second actuation resistance as in the above embodiment, another spring having a different spring constant or length can be used. The operating range can be easily changed by replacing it with .

[Brief explanation of drawings]

Figure 1 is a front view of the master robot, Figure 2 is a detailed view of the main parts, Figure 3 is a plan view of the means for recognizing operating limits in other parts, and Figure 4 is the correlation between operating range and resistance force. 5 is a front view of a master robot provided with another means for recognizing the operating limit, FIG. 6 is a diagram of the operating state of the main part, and FIG. 7 is a front view of the main part. 3, 25...Swivel base, 7, 8...Column, 15...Arm, 6, 14, 21, 24, 27...Spring.

Claims (1)

[Claims] 1. When operating the teaching handle provided on the arm member of the master robot, the operating range of the arm member and the support member attached to the base and provided with the arm member is zero or almost zero from the operating range to the vicinity of the operating limit. A constant small first operating resistance force is generated, and is larger than the first operating resistance force from near the operating limit of each member to the operating limit, and as it approaches the operating limit from near the operating limit. An operation range limiting device for a master robot, comprising operation resistance force generating means provided between the members to generate a second operation resistance force that rapidly increases.