CN109176572B

CN109176572B - Sliding detection probe for fingertip of robot and working method

Info

Publication number: CN109176572B
Application number: CN201811229642.3A
Authority: CN
Inventors: 蒋奇; 冯建航
Original assignee: Shandong University
Current assignee: Shandong University
Priority date: 2018-10-22
Filing date: 2018-10-22
Publication date: 2020-10-30
Anticipated expiration: 2038-10-22
Also published as: CN109176572A

Abstract

The invention relates to a sliding detection probe for a robot fingertip and a working method thereof, wherein the sliding detection probe comprises a probe body made of a flexible material, one side end face of the probe body is a fixed end face fixedly connected with a robot finger, the other side of the fixed end face is a sliding end face and used for sliding relative to the surface of an object to be grabbed, an optical fiber grating extending out of the probe body is fixed inside the probe body, the probe body comprises a contact area and a sensitive area, the grating area of the optical fiber grating is positioned in the sensitive area, and a protruding structure is arranged at the position of the sliding end face where the contact area is positioned.

Description

Sliding detection probe for fingertip of robot and working method

Technical Field

The invention relates to the technical field of intelligent sensing of robots, in particular to a sliding detection probe for fingertips of a robot and a working method.

Background

The automatic grabbing and any manipulation of an object by a manipulator in an intelligent robot are always difficult problems. The key to realizing the function is to detect the sliding information and the roughness information of the object in the grabbing process. Therefore, it is necessary to attach a slip detection sensor to the robot finger. The slide detection sensor is required to be small in size, high in sensitivity, high in response speed, and to reduce the wiring complexity.

A slip sense sensor capable of measuring pressure and slip simultaneously is invented in a research office of the institute of Shenzhen, Chunhua and Berkeli. The mode of embedding electrodes and piezoresistive films in flexible upper and lower bosses is adopted, and the pressure and the sliding are measured simultaneously by utilizing the triboelectrification and piezoresistive effects. But the conditioning circuit itself is complex and susceptible to external interference. It has also designed a capacitanc and has touched smooth sense sensor device to close fertile industry university, utilizes the electric capacity change that slides and cause to slide and detect, and this sensor structure is comparatively complicated, and capacitive sensor receives electromagnetic interference easily and influences. Seiichi Teshigawara, university of electrical communication in japan, studies a sliding sensing device based on pressure conductive rubber, which has good flexibility and accuracy, but is difficult to distinguish between the effects of tangential force and normal force.

In order to make the sensor have better flexibility, simple structure, high sensitivity and precision and immune electromagnetic interference influence, the structure and sensing principle of the sensor need to be improved.

Disclosure of Invention

The invention aims to overcome the defects of the prior art, and provides a sliding detection probe for a fingertip of a robot, which has the advantages of simple structure, easiness in manufacturing, improvement on precision and electromagnetic interference resistance due to the fact that an optical fiber grating is used as a sensing element, simplicity in wiring, capability of detecting the sliding and the roughness of an object in a grabbing process by combining an information processing algorithm, and great significance in realizing a mechanical hand touch and slip perception function.

In order to achieve the purpose, the invention adopts the following technical scheme:

the utility model provides a slip test probe for robot fingertip, includes the probe body of being made by flexible material, a side end face of probe body be used for with the fixed terminal surface of robot finger fixed connection, the opposite side of fixed terminal surface is the slip terminal surface for with wait to snatch the object surface and produce the relative slip, probe body inside is fixed with stretches out to the outside fiber grating of probe body, the probe body includes contact zone and sensitive area, fiber grating's grating district is located sensitive area, the slip terminal surface position department at contact zone place is equipped with protruding structure.

Furthermore, the axis of the fiber bragg grating is parallel to the fixed end face and the sliding end face, and the axis direction of the fiber bragg grating is arranged along the direction in which the probe body and the surface of the object to be grabbed slide relatively.

Further, the probe body is made of flexible silica gel materials.

Further, the surface of the convex structure, which is used for being in contact with the object to be grabbed, is a concave-convex surface.

Furthermore, the convex part of the concave-convex surface adopts a convex trapezoid or arc shape.

Furthermore, the probe body is obtained by adopting a 3D printing corresponding mould and then molding through a silica gel filling method.

The invention also discloses a working method of the sliding detection probe for the fingertip of the robot, which comprises the following steps: the fiber bragg grating is connected with a demodulator, the probe body is pasted to the surface of a robot finger through a fixed end face, the probe body is in contact with the surface of an object to be grabbed, the protruding structure is in contact with the object to be grabbed, the sliding end face corresponding to the sensitive area is not in contact with the surface of the object to be grabbed, the finger tip of the robot drives the probe body to slide relative to the surface of the object to be grabbed, the probe body made of a flexible material generates tangential strain, the tangential strain is transmitted to the sensitive area through a contact area, the grating area of the fiber bragg grating in the sensitive area detects the tangential strain, and the wavelength signal is demodulated through the demodulator to obtain sliding information.

The invention has the beneficial effects that:

1. the sliding detection probe has simple structure and wiring and convenient manufacture, and uses the fiber bragg grating as a sensing element, thereby improving the precision and resisting electromagnetic interference.

2. According to the sliding detection probe, the sliding end face is provided with the convex structure, when the sliding detection probe slides relatively, only the sliding end face of the contact area is in contact with an object to be grabbed, and the sliding end face of the sensitive area is not in contact, so that the influence of the change of positive pressure on a grating signal is reduced, and the detection precision is improved.

3. According to the sliding detection probe, the surface of the convex structure is a concave-convex surface, so that the friction force is increased, and the sensitivity is improved.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the application and, together with the description, serve to explain the application and are not intended to limit the application.

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a schematic diagram of a finite element simulation of the present invention;

the optical fiber grating optical fiber sensing device comprises a fixed end face 1, a sliding end face 2, an optical fiber grating 3, a grating area 3-1, a contact area 4, a sensitive area 5, a protruding structure 6 and a concave-convex surface 7.

Detailed Description

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

For convenience of description, the words "up", "down", "left" and "right" in the present invention, if any, merely indicate correspondence with up, down, left and right directions of the drawings themselves, and do not limit the structure, but merely facilitate the description of the invention and simplify the description, rather than indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the invention.

As described in the background art, the conventional sliding detection probe for a robot finger is complicated in structure and is easily subjected to electromagnetic interference, and in view of the above problems, the present application provides a sliding detection probe for a robot finger tip.

In a typical implementation of the present application, as shown in fig. 1, a slip test probe for robot fingertip includes the probe body made of flexible silica gel, the probe body adopts the cuboid structure, and its up end is used for fixing with the robot finger, for fixed terminal surface 1, the terminal surface of fixed terminal surface offside is used for producing the relative slip with waiting to snatch the object, for sliding end 2, this internal fixation of probe has both ends to stretch out to the outside fiber grating 3(FBG) of probe body, fiber grating's axis is parallel with fixed terminal surface and sliding end, and fiber grating's axis direction is the same with the probe body and the relative slip's direction of waiting to snatch the object surface, in this embodiment, fiber grating's axis is perpendicular to the probe body and goes up along the both sides terminal surface at relative slip direction place, the probe body divide into contact zone 4 and sensitive zone 5, the grating area 3-1 of the fiber grating is located in the sensitive area, a protruding structure 6 is arranged on the sliding end face of the position where the contact area is located, the end face of the protruding structure is a concave-convex face 7, and the protruding shape of the concave-convex face can be a protruding trapezoid or an arc.

When the whole probe body is processed, a corresponding die is processed by a 3D printing method, and then silica gel is used for pouring and forming, so that the probe is convenient to process and high in processing efficiency.

When the sliding detection probe for the fingertip of the robot is used, the probe body is small in size and can be directly adhered to the finger of the robot through the fixed end face, the optical fiber part of the optical fiber grating is connected with the demodulator, the protruding structure of the sliding end face is in contact with the surface of an object to be grabbed, the robot hand drives the protruding structure of the sliding end face to relatively slide along the surface of the object to be grabbed, the probe body generates tangential strain, the generated tangential strain is transmitted to the sensitive area through the contact area, the grating area in the sensitive area can detect the tangential strain, and the wavelength signal is demodulated through the demodulator to obtain sliding information.

According to the sliding detection probe, the sliding end face is provided with the convex structure, when the sliding detection probe slides relatively, only the sliding end face of the contact area is in contact with an object to be grabbed, and the sliding end face of the sensitive area is not in contact, so that the influence of the change of positive pressure on a grating signal is reduced, and the detection precision is improved.

According to the sliding detection probe, the surface of the convex structure is a concave-convex surface, so that the friction force is increased, and the sensitivity is improved.

The finite element simulation diagram of the sliding detection probe is shown in fig. 2, and as can be seen from fig. 2, the tangential strain of the contact area along the X direction can be effectively transmitted to the sensitive area, so that the sliding detection probe can effectively detect the relative sliding of the finger and the object to be grabbed through the tangential deformation.

Although the embodiments of the present invention have been described with reference to the accompanying drawings, it is not intended to limit the scope of the present invention, and it should be understood by those skilled in the art that various modifications and variations can be made without inventive efforts by those skilled in the art based on the technical solution of the present invention.

Claims

1. A sliding detection probe for a robot fingertip is characterized by comprising a probe body made of a flexible material, wherein one side end face of the probe body is used as a fixed end face fixedly connected with a robot finger, the other side of the fixed end face is a sliding end face and used for sliding relative to the surface of an object to be grabbed, a fiber grating extending out of the probe body is fixed inside the probe body, the probe body comprises a contact area and a sensitive area, the grating area of the fiber grating is located in the sensitive area, and a protruding structure is arranged at the position of the sliding end face where the contact area is located;

the surface of the protruding structure, which is used for being in contact with an object to be grabbed, is a concave-convex surface.

2. The sliding detection probe for the fingertip of the robot according to claim 1, wherein the axis of the fiber grating is parallel to the fixed end face and the sliding end face, and the direction of the axis of the fiber grating is arranged along the direction in which the probe body slides relative to the surface of the object to be grasped.

3. The sliding detection probe for a robot fingertip as claimed in claim 1, wherein said probe body is made of a flexible silicone material.

4. The sliding detection probe for a fingertip of a robot as claimed in claim 1, wherein a convex portion of the concave-convex surface is a convex trapezoid or an arc.

5. The sliding detection probe for the fingertips of the robot as claimed in claim 1, wherein the probe body is formed by 3D printing of a corresponding mold and then molding by a silicone infusion method.

6. A working method of the sliding detection probe for the fingertip of the robot according to any one of claims 1 to 5, characterized in that: the fiber bragg grating is connected with a demodulator, the probe body is pasted to the surface of a robot finger through a fixed end face, the probe body is in contact with the surface of an object to be grabbed, the protruding structure is in contact with the object to be grabbed, the sliding end face corresponding to the sensitive area is not in contact with the surface of the object to be grabbed, the finger tip of the robot drives the probe body to slide relative to the surface of the object to be grabbed, the probe body made of a flexible material generates tangential strain, the tangential strain is transmitted to the sensitive area through a contact area, the grating area of the fiber bragg grating in the sensitive area detects the tangential strain, and the wavelength signal is demodulated through the demodulator to obtain sliding information.