JPS6156891A - Sliding sense sensor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a small and inexpensive slip sensor.

[Prior art]

There are various problems in order to make robots perform the same sophisticated tasks as humans, and one of them is the development of sensory sensors similar to those possessed by humans.

For example, consider a case where a human holds an egg with his or her fingertips. In this case, pressure sensation and veri-sensation at the fingertips play an important role.

In other words, humans use pressure and slip sensations to grasp eggs while making judgments to prevent the egg from falling from their fingertips and to avoid crushing the egg.

Sensory sensors for robots use pressure-sensitive rubber,
There are various kinds of sensors that use strain gauges, and they are actually used, but there are few practical slip sensors. It is sandwiched between the wooden fingers 2 and 3. Inside the finger part 2, there is a roller 5 supported at both ends by leaf springs 4, and the roller 5 is rotatable around an axis 6 and protrudes from a window 7 provided in the finger part 2. is configured to do so. The finger portion 3 also has a similar configuration.

When the fingers 2 and 3 are open, a portion of the roller 5 is attached so as to protrude from the gripping surface, and when the fingers 2 and 3 are closed to grip the object 1, the leaf spring 4 is bent and the roller 5 is 5 retreats to the gripping surface of finger parts 2 and 3, so that finger parts 2 and 3
The object 1 is held between the entire gripping surfaces of the rollers 5 and the rollers 5 are pressed against the object 1.

As shown in FIG. 2, inside the roller 5, a shaft 6 supported by a leaf spring 4 supports an intermediate shaft 8, and the roller 5 is placed on the intermediate shaft 8 via a bearing 9. A slit disk 10 is provided on the inner wall of the roller 5, and a light emitting element] 1 and a light receiving element 12 are supported by an intermediate shaft 8 so as to sandwich the slit disk 10. The slit disk 10 has a large number of slunts on its circumference, and when the roller 5 rotates with respect to the intermediate shaft 8, the output of the light receiving element 12 changes, and the rotation angle can be detected.

With the slip sensor configured in this manner, the finger portion 2,
3, it is possible to grip the object 1 with the minimum force that will prevent it from slipping. However, such conventional slip sensors are complicated, large in size, and expensive.

,! , [Summary of the Invention] This invention was made in view of the above points, and includes a tuning fork built into the finger so that vibration is generated in the tuning fork when a gap occurs between the finger and the object to be grasped. The purpose is to realize a small and inexpensive slip sensor. The present invention will be explained below with reference to the drawings.

[Embodiments of the invention]

FIG. 3 shows an embodiment of the present invention.

In FIG. 3, the structure of the finger parts 2 and 3 is the same as that in FIG. 1, which shows the conventional example. Inside of finger part 2 (Koha roller 5
Instead, one side of the base 14 of the tuning fork-shaped vibrating piece 13 is elastically supported by a rubber-like elastic body 15 on the inner surface of the finger portion 2 by appropriate means such as adhesive. Furthermore, a guide piece 16.1 is provided on the inner surface of the finger portion 2 so as to sandwich the top and bottom of the base 14.
7 is fixed, and in the state shown in FIG. 3, the vibrating piece 13 can be slightly rotated only in the horizontal plane using the base 14 as a fulcrum. A piezoelectric element 18 is pasted on the surface of the vibrating piece 13.
□The vibration of the vibrating piece 13 is transferred to the piezoelectric element 18.
□It can be detected as a voltage change. Note that the finger portion 3 side is also configured in the same manner.

FIG. 4 is an enlarged view of the vibrating element 13, and the state shown in FIG.
It is shown rotated by °. A plate 20 having numerous needle-like protrusions 19 is fixed to the surface that contacts the object 1. When the finger parts 2 and 3 are open, the tips of the needle-like protrusions 19 are set to slightly protrude from the gripping surface.
When the object 1 is grasped by closing the fingers 2 and 3, the tip of the needle-like protrusion 19 retreats to the grasping surface due to the bending of the rubber-like elastic body 15. The tip of one of the protrusions is pressed against the object 1. In this state, when the object 1 slides against the fingers 2 and 3, the tip of the needle-like protrusion 19 similarly slides on the surface of the object 1, causing the tuning fork-shaped vibrating piece 12 to vibrate. If the voltage generated in the piezoelectric element 18 due to this vibration is extracted through the signal line 21 and observed, it can be determined that slippage has occurred.

The needle-like protrusions 19 are a device to make it easier to cause the tuning-fork-shaped vibrating piece 13 to vibrate, and here an example is shown in which a plate 20 having the needle-like protrusions 19 on its surface is attached by etching. The present invention is not limited to this, but the surface of the tuning fork-shaped vibrating piece 13 may be etched directly, or particles of tungsten, carbide, or the like may be sprayed to provide protrusions.

Additionally, small pieces of sandpaper or sand cloth may be attached. The number of needle-like protrusions 19 is not limited to an infinite number;
As shown in the figure, even one vibrating element 13 for each vibrating element 13 can sufficiently perform its function.

Furthermore, the elastic body that supports the tuning fork-shaped vibrating piece 13 is not limited to the rubber-like elastic body 15, and may be a metal leaf spring or a coil spring. In addition, when the tuning fork-shaped vibrating piece 13 is made of metal, the piezoelectric element 18 is fixed to a part of the vibrating piece 13 in order to detect vibration as shown here, but the tuning fork-shaped vibrating piece 13 itself If it is manufactured using the piezoelectric element 18, this is not necessary.

FIG. 6 shows an example in which the vibrating piece 13 is manufactured using a bimorph type piezoelectric element. Two bimorph-shaped piezoelectric elements 22 are placed back to back with gold ff,! It is fixed to the block 23 by bolting or the like, and the signal line 21 is taken out from the surface of the piezoelectric element 22 and the metal block 23.

〔Effect of the invention〕

As explained above, in the slip sensor of the present invention, needle-like protrusions are provided on the surface of a tuning fork-shaped vibrating piece, and when a slip occurs between the vibration piece and the object to be gripped, the slip sensor vibrates through the needle-like protrusions. Since the structure is such that the pieces are vibrated and the vibrations are detected, the structure is extremely simple, and it has the advantage of being able to be miniaturized and manufactured at low cost.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of a conventional slip sensor, FIG. 2 is a sectional view of the main part of FIG. 1, and FIG. 3 is a partially cutaway view showing an example of the slip sensor of the present invention. FIG. 4 is an enlarged view of a main part of the embodiment shown in FIG. 3, and FIGS. 5 and 6 are perspective views of main parts showing other embodiments of the present invention. In the figure, 1 is the object to be grasped, 2 and 3 are fingers, 'l
13 is a vibrating piece, 14 is a base, 15 is a rubber-like elastic body, 1
6. 17 is a guide plate, 18 is a piezoelectric element, 19 is a needle-like projection, 20 is a plate having needle-like projections on its surface, 21 is a signal line, 2
2 is a bimorph piezoelectric element, and 23 is a metal block. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] In a gripping mechanism that grips an object with two fingers that open and close, a tuning fork-shaped vibrating piece is supported by an elastic body on a part of the fingers, and a protrusion is provided on a surface of the tuning fork-shaped vibrating piece that comes into contact with the object. A slip sensor characterized in that a tip of the protrusion is slightly protruded from a gripping surface of the finger.