JPS61205831A - Matrix tactile sensation sensor - Google Patents

Abstract

PURPOSE:To make it possible to accurately detect the pressure distribution of a two-dimensional plane, by a sensor having high strength and a simple and inexpensive structure constituted so as to detect a brightness state in such a state that a plurality of semispherical elastomers are contacted with a transparent plate. CONSTITUTION:An elastomer film 1, semispherical elastomers 2, optical fibers 4, a camera or two-dimensional light receiving element 6 and a calculation circuit 7 are provided. When matter is grasped and load is acted on the elastic film 1 in the direction shown by an arrow 8, the elastomers 2 are pressed to a transparent plate 3 with the deformation of the elastic film 1. When the transparent plate 3 is looked from below at this time, only the parts contacted with the elastomers 2 look dark. An area is calculated from the area ratio of bright parts and dark parts, detected by the element, by the circuit 7. Further, the circuit 7 calculates an inertia secondary moment from the distribution positions of dark parts to detect the offset of load. Therefore, the strength of the sensor is high and the pressure distribution of a two-dimensional plane can be accurately detected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a matrix tactile sensor used for rounding to detect the distribution of pressure observed on a two-dimensional plane.

[Prior Art] Conventionally, this type of device measures the amount of contact deformation using conductive rubber, electrostrictive elements, strain gauges, etc., and has a bare matrix of light-emitting elements and light-receiving elements on a silicone rubber substrate. A structure is proposed in which the displacement of silicone rubber is detected as a change in the amount of light.

[Problems to be solved by the invention] By the way, when conductive rubber is used, the contact state is ON-OFF! It is a simple structure if only to detect l, but if you try to detect the pressure distribution on a two-dimensional plane, not only will the electrode structure become complicated, but it will be difficult to obtain conductivity with uniform characteristics, making it impractical. Become something. Further, when an electrostrictive element is used, there are structural restrictions to prevent brittle destruction, and K is not suitable for incorporating into robot fingers that require flexibility. Further (, when using a strain gauge, 2
Dimensional Ffi&C high-density array is difficult to avoid mutual interference (511: 0 point compensation at the time of contact is difficult due to the influence of external disturbances), and a light emitting element and a light receiving element are paired on a silicone rubber substrate. In the case of a sensor with a structure that detects the displacement of silicone rubber as a change in light intensity, the q# characteristic changes due to changes in the light reception characteristics due to heat generation in the light emitting part, changes in reflectance due to dust and dew, etc. In addition, it is difficult to install the senna on an arbitrary curved surface, and it becomes an expensive senna.

The problem of the present invention is how to realize a senna that eliminates the drawbacks of the conventional devices.

c. Means for Solving Problems] The matrix tactile sensor of the present invention includes an elastic film to which a load pressure is applied, a transparent plate disposed along the elastic film, and a flat portion formed by the elastic film. a plurality of hemispherical elastic bodies that are in contact with or fixed to one surface of the transparent plate, and whose spherical portions are in contact with one side of the transparent plate; A book optical fiber, a light source that irradiates light to the transparent plate side through a part of the plurality of optical fibers, and a camera that observes the transparent plate side through another part of the plurality of optical fibers. Alternatively, it is characterized by comprising a two-dimensional light-receiving element and a calculation circuit that calculates the distribution shape and straightness of the nine bright and dark areas observed by the camera or the two-dimensional light-receiving element.

[Effect]

In the present invention, when a load pressure is applied to the elastic membrane, the hemispherical elastic body located in the area where the load pressure is applied is deformed, and the bright and dark areas on the transparent plate change. Observed with a dimensional photodetector. Here, based on the above observation results, the distribution shape of the clear culvert part,
The area is calculated.

C! ! ! Plum example IEI! ! FIGS. 1 to 3 are diagrams showing one embodiment of the present invention. The embodiment described here is an embodiment in which the present invention is applied to a gripping section of an intelligent robot that grips an object.

In the first package, l is an elastic film, 2 is a hemispherical elastic body, 3 transparent plates 1 and 4 are optical fibers, 5 is a light source, 6 is a camera or two-dimensional light receiving element, and 7 company calculation circuits. Dechiru. 8 is the direction of load action.

Pressure is applied to the upper surface of the elastic body [1 in the direction of arrow 8 when an object is gripped. Below this elastic membrane l, this! A transparent plate body 3 is arranged along the 111 body IIK. Elastic body! ! A plurality of hemispherical elastic bodies 3, 3, . . . are arranged between the &1 and the transparent plate body 3. As shown in the ttgz diagram, the hemispherical elastic body 3 has a flat portion 2
a is fixed to the lower surface of the elastic membrane 1, and the spherical portion 2b is brought into contact with the upper surface of the transparent plate 3.

One end of each of the plurality of optical fibers 4 is closely identified on the lower surface of the transparent plate 3. The other ends of the optical fibers 4, 4, . The light source 5 irradiates the transparent plate 3flI through the optical fiber 4. The camera t or the two-dimensional light receiving element 6 is used to observe the dark state of the transparent plate 3. The calculation circuit 7 calculates the distribution shape and area of the bright and dark portions on the transparent plate 3 side based on the output of the camera or the two-dimensional light receiving element 6.

In the above configuration, when an object is gripped and a load is applied to the curved body [1 in the direction of arrow 8], the hemispherical elastic body 2 is pressed against the transparent plate body 3 as the elastic body film l is deformed. .

When the transparent plate body 3f is viewed from below, only the portion where the hemispherical elastic body 2 is in contact appears dark. In Fig. 3, the small circle 9 indicated by the broken line in the figure #, which shows the pattern that appears when the cylinder is pressed, is the position of the hemispherical elastic body 2, and the large circle 10 indicated by the dashed-dotted line.
indicates the outline of the cylinder. The area where they touched is observed as a dark area 11. In order to clearly observe the contact pattern, an optical fiber 4.4 is placed in close contact with the transparent plate 3.
- A light source 5 is connected to a part of the contact surface to uniformly illuminate the entire contact surface. Other optical fibers 4.4, . The signal is supplied to the calculation circuit 7 to determine the area of the contact portion 11 and its distribution.
Although not illustrated, this information for calculating I is transmitted to the main controller of the intelligent robot and used as a control signal for the handling operation of the intelligent robot.

Elastic membrane: 11, the thickness is from several tens of μm to several tens of micrometers,
The material may be rubber or plastic. It is preferable that the hemispherical elastic body 2 be made by integral molding with the elastic body membrane 1, but it should be constructed separately from the elastic body membrane 1 so that its flat part 2a11r is brought into contact with the lower surface of the pseudo-elastic body membrane 1 ( The radius of the hemispherical elastic body 2 is in the range of several 100 μm to several U, and the radius of the hemispherical elastic body 2 is in the range of several 100 μm to several U. , can be selected depending on the deformation of the gripping part, etc.

Load load! If the radius R1 of the hemispherical elastic body is IP% and the total contact area S, then according to an experiment based on Hertzian theory, 3oc'p+
- It can be expressed by the relational expression R [α: constant]. The Minode circuit 7 calculates a direct product based on the area ratio of the bright and dark areas detected by the camera or the two-dimensional light receiving element 6. Further, the calculation circuit 7 calculates the second moment of inertia from the distribution position of the dark part, and detects the bias of the load.

In this invention, the expansion and relief cutting plate 3 is made into a spherical or arbitrarily curved surface, and the optical fiber 4 is closely attached along the curved surface, and the i31%
body, one fir with a hemispherical elastic body 2 attached on a 30 curved surface
Covering with the body membrane 1 can also be easily realized.

The number of optical fibers 4 constituting the optical fiber bundle may be such that the contact area can be determined, and the material thereof may be glass or plastic.

〔Effect of the invention〕

According to the present invention, since a plurality of hemispherical elastic bodies are in contact with a transparent plate body to detect brightness and darkness under good conditions, the sensor has high strength (and is simple and inexpensive). It is possible to accurately detect pressure distribution, etc. on a two-dimensional plane.
Since the contact force sensing part and the optical 2D light receiving element are connected by an optical fiber, the light source and the force, 2D light receiving element can be installed at any desired position. 6. Also, the material of the elastic membrane can be selected arbitrarily, so the material, surface roughness, etc., can be selected to suit the conditions of grasping and excavation. It has the advantage of being able to be designed with

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 4 is a schematic diagram of the matrix tactile sensor according to the present invention, the second factor is a sectional view of the main part of the sensor, and FIG. It is a figure which shows the contact state of a hemispherical elastic body and a transparent plate body when a cylinder is pressed against it. 1... Elastic body membrane, 2... Hemispherical elastic body, 21L... Flat part, 2b... Spherical part, 3... Transparent plate body, 4... optical fiber, 5... light source, 6... camera or 2
Dimensional light receiving element, 7... Calculation circuit. Figure 1

Claims (1)

[Claims] an elastic membrane to which a load pressure is applied; a transparent plate disposed along the elastic membrane; a flat portion contacts or is fixed to one surface of the elastic membrane, and a spherical portion is attached to the transparent plate; a plurality of hemispherical elastic bodies in contact with one surface of the transparent plate, and a plurality of optical fibers with one end tightly attached to the other surface of the transparent plate;
A light source that irradiates light to the transparent plate side through some of the plurality of optical fibers, and a camera or two-dimensional light receiving element that observes the transparent plate side through another part of the plurality of optical fibers. , and a calculation circuit that calculates the distribution shape and area of bright and dark areas observed by the camera or the two-dimensional light-receiving element.