KR101457998B1 - Working Robot having Sensor using Optical fiber - Google Patents

Abstract

A working robot, which is placed in a workplace to work, includes a work member for performing a predetermined work and a sensor coupled to the work member. The sensor includes an optical fiber coupled to the work member to refract when a shape of the work member is varied by an external force; and a plurality of grids arranged in the optical fiber in the longitudinal direction of the optical fiber, wherein incident light entered the optical entrance of the optical fiber is interfered and reflected by the grids and outputted as reflected light through the optical entrance, and whether the external force is in affect is detectable by detecting the variation of a wave spectrum of the reflected light, which is generated from the variation of an interval of the grid by the refraction of the optical fiber.

Description

Technical Field [0001] The present invention relates to a working robot having a sensor using an optical fiber,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work robot having a sensor using an optical fiber, and more particularly, to a work robot having a sensor capable of detecting an external force and a refracting state, .

As a working robot for performing a predetermined operation by inserting a long hollow body into a narrow space, there is a typical insertion robot for minimally invasive surgery.

Various types of insertion-type robots used for endoscopic surgery are in the spotlight because they can minimize the injuries caused by invasion. However, it is difficult for the user to visually confirm the refracting state of the implantable robot in the body, which is frequently refracted in the human body, or the precise state of the end effector located at the end of the device, by using the implantable robot in the body.

Therefore, in order to perform safe operation, it is necessary to provide a method of detecting the refractive state of the robot body and the external force applied to the end effector to inform the user.

BACKGROUND ART [0002] Conventionally, a body-insertable type robot has various mechanical sensors for detecting a refracted state of a robot body and an external force applied to an end effector.

Therefore, the insertion type robot according to the prior art has a problem in that the configuration is complicated and it is difficult to miniaturize.

Korean Patent Publication No. 10-2008-0047318

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to provide a method and apparatus for detecting an external force acting on a work robot using a sensor composed of an optical fiber and a grating formed inside the optical fiber, The present invention relates to a robot that can be used as a robot.

In order to accomplish the above object, a work robot inserted into a work space according to an aspect of the present invention includes a worker for performing a predetermined job and a sensor coupled to the worker . The sensor includes a plurality of gratings arranged in the longitudinal direction of the optical fiber inside the optical fiber, the optical fiber being coupled to the optical fiber and corresponding to the shape of the optical fiber when the shape of the optical fiber is changed by an external force, The incident light incident on the light entrance of the optical fiber is interfered with and reflected by the plurality of gratings and is output as reflected light through the light entrance, and the interference caused by the change in the interval of the grating due to the refraction of the optical fiber It is possible to detect whether the external force acts or not by detecting a change in the wavelength spectrum of the reflected light.

The work robot may further include a body extended from a rear end of the worker. At this time, the optical fiber passes through the inside of the body and extends to the worker, and the optical fiber located inside the body is refracted when the body is refracted, and is generated due to a change in the interval of the grating positioned on the worker Detecting a change in the wavelength spectrum of the reflected light caused by a change in the interval of the lattice located inside the body and detecting a change in the refraction state of the body by detecting a change in the wavelength spectrum of the reflected light, .

According to an embodiment of the present invention, the gratings of the grating are formed by paired gratings of n (n > = 2, natural numbers) in the optical fiber, n gratings are arranged at equal intervals in one grating, The spacing between the gratings of each grating portion is different from each other in each grating portion.

In addition, a plurality of sensors may be provided, and the optical fibers of each of the plurality of sensors may be disposed at different positions with respect to the vendor so as not to overlap each other while being separated from the longitudinal center axis of the body, have.

According to another embodiment, the plurality of gratings are arranged at mutually different intervals, and the reflected light output to the light inlet of the optical fiber includes first reflected light and second reflected light polarized in different directions, The reflected light and the second reflected light form different wavelength spectrums.

Further, the interval between the plurality of gratings may be increased or decreased as a function of the distance from the light entrance.

According to another embodiment, the worker has an elastically deformable skin, and the optical fiber may be inserted into the skin or attached to the skin.

According to another embodiment of the present invention, the working robot is an insertion-type robot inserted into a body to perform a minimally invasive procedure.

1 is a conceptual diagram of a work robot according to an embodiment of the present invention.
2 is a side view of a sensor according to a first embodiment of the present invention.
3 shows a wavelength spectrum of incident light and reflected light through the light entrance of the sensor according to the first embodiment.
4 to 6 are conceptual diagrams of a work robot provided with a sensor according to the first embodiment.
7 and 8 are a side view and a front view of a sensor according to a second embodiment of the present invention.
9 shows a wavelength spectrum of reflected light output through the light entrance of the sensor according to the second embodiment.
10 shows a state of use of the sensor according to the second embodiment.
11 and 12 are views for explaining the principle of detecting the refraction position of the sensor according to the second embodiment.
13 and 14 are diagrams for explaining the principle of detecting the degree of refraction of the sensor according to the second embodiment.
Fig. 15 is a view for explaining the principle of detecting the refraction direction and the angle of the sensor according to the embodiment of Fig. 7 and the second embodiment.
16 to 18 are conceptual diagrams of a work robot provided with a sensor according to the second embodiment.
19 is a side view of a sensor according to a third embodiment of the present invention.
20 shows a wavelength spectrum of reflected light output through the light entrance of the sensor according to the third embodiment.
FIG. 21 shows a state of use of the sensor according to the third embodiment.
22 to 24 are conceptual diagrams of a work robot provided with a sensor according to the third embodiment.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Although the present invention has been described with reference to the embodiments shown in the drawings, it is to be understood that the technical idea of the present invention and its essential structure and action are not limited by this embodiment.

1 schematically shows a work robot 1 according to an embodiment of the present invention.

As shown in FIG. 1, the work robot 1 includes a work shop 2 for performing a predetermined work and a flexible body 3 which is elongated at a rear end of the work shop 2.

The work robot 1 according to the present embodiment is an insertion-type robot inserted into a body to perform minimally invasive procedures. The work robot 2 is equipped with a grip capable of gripping an object at an insertion position.

The work robot 1 is provided with a sensor using an optical fiber and detects the state of the work robot 1 performing work in a state in which it can not be visually recognized.

Hereinafter, embodiments of the sensor will be described with reference to the drawings.

[First Embodiment]

2 schematically shows the structure of the sensor 10 according to the first embodiment.

The sensor 10 includes an optical fiber and a plurality of gratings 40 formed within the optical fiber.

The optical fiber includes a cladding 20 formed of a glass material and freely refractable and a core 30 formed along the longitudinal direction of the cladding 20 at the center of the cladding 20 . The refractive index of the cladding 20 is n _1, and the refractive index of the core 30 is n ₀ . At both ends of the optical fiber, a light inlet 50 through which light is incident from a light source 91 (see FIG. 4) and a light outlet 60 through which light is output through the core 30 are formed.

A plurality of gratings 40 are formed inside the core 30 and are arranged at the same interval A along the longitudinal direction of the core 30. [ Grating 40 has a portion which through the ultraviolet light in the manufacturing process of the optical fiber changes in the physical properties of the core (30) portion, have a refractive index (n ₀ + △ n).

The grating 40 interferes with the incident light passing through the core 30 and a part of the incident light is reflected by the plurality of gratings 40 and is output as reflected light through the light entrance 50.

3 (a) shows a wavelength spectrum of a wavelength vs. an incident light incident through the light entrance 50, and FIG. 3 (b) shows a wavelength spectrum of the reflected light output through the light entrance 50. FIG. FIG.

Even if incident light having a wide wavelength is incident on the core 30, only the reflected light of a specific wavelength? _B through the light entrance 50 due to interference by the plurality of gratings 40 located in the middle of the core 30 . Specifically, a part of the incident light incident through the light entrance 50 collides with the first grating positioned first, and the remaining part of the incident light advances through the first grating. A part of the light passing through the first grating collides with the second grating and the reflected light meets the first grating again and partly passes therethrough and is first combined with the light reflected by the first grating, Is again reflected by the first grating and directed to the second grating. The same phenomenon occurs repeatedly in the gratings positioned after the second grating, and the incident light incident on the optical fiber is reflected and passed by the plurality of gratings 40 and interferes with each other. After all, even if the incident light has the form of the wavelength spectrum shown in Figure 3 (a) is incident, reflected light of the wavelength other than the wavelength (λ _B), as shown in Figure 3 (b) are almost all the interference due to each other And only the reflected light having the wavelength? _B is outputted through the light entrance 50.

At this time, the wavelength (? _B ) of the reflected light can be expressed by the following equation (1).

[Equation 1]

λ _B = 2 · n _eff · Λ

Here, n _eff is an index indicating the effective refractive index of the core.

When a refraction occurs in a specific portion of the optical fiber having the above-described configuration, a change occurs in the wavelength spectrum while the lattice spacing of the refracted portion changes. That is, when a change in the wavelength spectrum of the reflected light is detected, it can be confirmed that the optical fiber is refracted.

According to the present embodiment, the sensor 10 having the above-described configuration is formed inside the work robot 1. [

Figs. 4 to 6 schematically show a work robot 1 provided with a sensor 10. Fig. 5 and 6 show only the core 30 and the lattice 40 of the sensor 10 for convenience of illustration.

As shown in Fig. 4, the sensor 10 is inserted from the rear end of the body 3 of the work robot 1 to extend to the worker 2. The work robot 1 is coupled with a light source 91 for making incident light incident on the sensor 10 and an optical analyzer 92 for analyzing the wavelength spectrum of the reflected light output from the sensor 10. An optical distributor 93 for transmitting the reflected light output from the sensor 10 to the optical analyzer 92 may be further provided.

As shown in Fig. 5, the work shop 2 of the work robot 1 includes a skin 4 of an elastically deformable material such as rubber, for example. According to the present embodiment, the optical fiber of the sensor 10 is formed so as to be able to pass through all the sides of the worker 2.

6, the shape of the skin 4 of the elastic material is deformed when an external force is applied for holding the object M or the like, and the optical fiber of the sensor 10 is deformed in the shape of the skin 4 A part thereof is refracted in response to the change. When the optical fiber is refracted, the interval of the grating 40 located at the refraction portion changes, and the change of the wavelength spectrum of the reflected light is detected by the optical analyzer 92. If a significant change in the wavelength spectrum is detected, it is possible to know that a predetermined external force has been applied to the manufacturer 2.

[Second Embodiment]

FIG. 7 is a side view of the sensor 100 according to the first embodiment of the present invention, and FIG. 8 is a front view of the sensor 100 of FIG.

The sensor 100 includes an optical fiber and a plurality of gratings formed inside the optical fiber.

The optical fiber includes a cladding 110 extending to a predetermined length and a core 120 extending along the longitudinal direction of the cladding 110 inside the cladding 110. A buffer for surrounding the cladding 110 and a jacket for enclosing the buffer may be formed on the outer periphery of the cladding 110, but are not shown in the present embodiment.

The optical fiber is mainly made of a glass material such as silica (SiO ₂ ). The cladding 110 is made of pure silica and the core 120 is made of silica doped with germanium (Ge doped SiO ₂ ), so that refractive indexes are different from each other. At both ends of the optical fiber, a light inlet 130 through which light is incident from a light source 91 (see FIG. 16) and a light outlet 140 through which light is output through the core 120 are formed.

As shown in FIG. 7, a plurality of gratings g ₁ , g ₂ ,... G _a ,..., G _n are formed in the core 120 along the longitudinal direction of the core 120. Differs from the refractive index of the core 120 of the plurality of gratings g ₁ , g ₂ , ... g _a , ... g _n . On the other hand, the refractive indices of the plurality of gratings g ₁ , g ₂ , ... g _a , ..., g _n are equal to each other.

The plurality of gratings g ₁ , g ₂ , ... g _a , ..., g _n are spaced apart by different distances Λ ₁ , Λ ₂ , Λ _a , ... Λ _n-1 do. According to this embodiment, the spacing (Λ ₁ , Λ ₂ , ..., Λ _a , ... Λ _n-1 ) between the gratings increases from the light inlet 130 to the light exit 140 as _a constant function. According to this embodiment, the spacing (Λ ₁ , Λ ₂ , ... Λ _a , ... Λ _n-1 ) between the gratings gradually increases at a constant rate. According to this embodiment, the spacing (Λ ₁ , Λ ₂ , ... Λ _a , ... Λ _n-1 ) between the gratings increases with a constant function, but the spacing (Λ ₁ , Λ ₂ , .. it will be understood that also a _{Λ a, ... Λ n-1} ) so as to decrease at a constant function.

On the other hand, the core 120 of the optical fiber has a density in the horizontal axis (x) direction larger than a density in the vertical axis (y) direction. The density difference between the horizontal axis and the vertical axis of the core 120 is achieved by the stress enhancing unit 160.

The stress enhancing unit 160 is formed by inserting a material having a thermal expansion coefficient different from that of the cladding 110 into the cladding 110. As shown in FIG. 8, according to the present embodiment, two stress-strengthening portions 160 are formed symmetrically on the horizontal axis of the optical fiber about the core 120.

A process of forming the stress enhancing unit 160 on the optical fiber will be described. First, a cylindrical base material for forming an optical fiber is drilled at a position where the stress-strengthening portion 160 is to be formed, and the material of the stress-strengthening portion 160 is inserted. When the base material manufacturing process of the optical fiber is completed at a high temperature and the base material is drawn and cooled, an optical fiber is formed. At this time, due to the difference in the coefficient of thermal expansion between the cladding 110 and the stress-strengthening portion 160, there occurs a difference in shrinkage in the horizontal direction and shrinkage in the vertical direction, so that tensile stress is generated only in one direction in the core 120.

According to this embodiment, the two stress-strengthening portions 160 are formed symmetrically on the horizontal axis of the optical fiber about the core 120, and the thermal expansion coefficient of the stress-strengthening portion 160 is equal to the thermal expansion coefficient of the cladding 110 Substance smaller than coefficient is used. In this case, the stress-strengthening portion 160 is contracted less than the cladding 110 at the time of contraction, and the stress-strengthening portion 160 compresses the core 120 in the horizontal axis direction of the optical fiber. With such a configuration, the core 120 of the optical fiber has a density in the horizontal axis (x) direction larger than a density in the vertical axis (y) direction.

The refractive index of the core 120 of the optical fiber in the direction of the horizontal axis x becomes larger than the refractive index of the direction of the vertical axis y because the density in the horizontal axis x direction is larger than the density in the vertical axis y direction. In addition, the refractive index in the horizontal axis (x) direction of the plurality of gratings formed by changing the physical properties of the core 120 is larger than the refractive index in the vertical axis (y) direction.

Therefore, when light incident through the light entrance of the core 120 and having undergone interference by a plurality of gratings is again emitted through the light entrance, reflected light polarized in the horizontal axis (x) direction and reflected light polarized in the vertical axis (y) Have a wavelength difference DELTA lambda.

Hereinafter, the reflected light characteristic of the sensor 100 according to the present embodiment will be described in more detail with reference to FIG.

The reflected light R reflected by the plurality of gratings g ₁ , g ₂ , ... g _a , ..., g _n is incident on the light entrance 130 when the incident light enters through the light entrance 130 of the optical fiber. .

As described above, since the interval between the plurality of gratings g ₁ , g ₂ , ... g _a , ..., g _n increases at a constant rate, the wavelength spectrum of the reflected light R (C _x , C _y ) having a wide spectrum of wavelengths.

The peaks of the curves C _x and C _y correspond to the peaks of the reflected light of each of the plurality of gratings g ₁ , g ₂ , ... g _a , ..., g _n , respectively, (? ₁ ,? ₂ , ...? _A , ...? _N ).

As described above, the wavelength difference? Is generated between the first reflected light polarized in the direction of the horizontal axis (x) and the second reflected light polarized in the vertical axis (y) direction output through the light entrance of the core 120 . 9, the first reflected light polarized in the horizontal axis (x) direction and the second reflected light polarized in the vertical axis (y) have two curved lines C _x and C _y , which are different in band from each other Is displayed. The two curves C _x and C _y independently represent the wavelength of the reflected light by each of the plurality of gratings g ₁ , g ₂ , ... g _a , ..., g _n . For example, in the curves (C _x , C _y ), the wavelength (λ _x1 ) and the wavelength (λ _y1 ) both represent the wavelength of the reflected light reflected by the grating (g ₁ ). The wavelength (λ _x1 ) and the wavelength (λ _y1 ) have wavelength differences of Δλ.

The optical fiber 100 according to the present embodiment is configured such that the distance between the plurality of gratings g ₁ , g ₂ , ... g _a , ..., g _n increases or decreases, .

When the center of the optical fiber is the same as the center of refraction of the entire optical fiber, the lattice spacing based on the center of the optical fiber has an average degree of change of 0 (the distance between two adjacent lattices , Whereas on the opposite side, the spacing of the two gratings is reduced, so that the change in mean spacing is virtually zero), and the exact state of refraction can not be calculated.

Accordingly, as shown in FIG. 10, according to the present embodiment, the center of the core 120 is spaced apart from the center of refraction of the entire sensor 100. 10, the center of the sensor 100 is positioned at the center of the body 3 (i.e., the center of refraction) of the work robot 1 so that the center of the sensor 100 is spaced apart from the actual center of refraction, And so on.

 Hereinafter, a process of detecting the position where the optical fiber of the sensor 100 is refracted will be described with reference to FIGS. 11 and 12. FIG.

As described above, the optical fiber of the sensor 100 according to the present embodiment uses both the first reflected light polarized in the horizontal axis (x) direction and the second reflected light polarized in the vertical axis (y) direction in order to grasp the refracted state , Only the wavelength spectrum of the second reflected light polarized in the direction of the horizontal axis (x) is shown in FIG. 12 for convenience of explanation. 12 shows a curve C _{before before the} refraction occurs and a curve C _after after the refraction occurs.

Assuming that the optical fiber is refracted at the refracting portion 1 (Fig. 11), the distance between the grating located at the refracting portion 1 and the adjacent grating is changed (Fig. 12 shows that the grating interval at the refracting portion 1 increases As shown in Fig. Accordingly, the wavelength of the reflected light due to the grating located at the refracting portion 1 also changes. As a result, as shown in Fig. 12, the magnitude R of the reflected light at the wavelength? ₁ decreases and the wavelength (? ₁ ) near the wavelength? ₁ due to the wavelength change of the reflected light due to the grating located at the refracting portion 1 The wavelength of the reflected light) is increased and the peak P ₁ is generated.

When the optical fiber is further refracted at the refraction portion 2, as shown in Fig. 12, the wavelength? ₂ of the reflected light due to the grating located at the refraction portion 2 moves sideways and a peak P ₂ is generated .

According to this embodiment, since the wavelength of the reflected light by each of the plurality of gratings in the state where the optical fiber is not refracted is known, a wavelength in which the size of the reflected light decreases in the wavelength spectrum of the reflected light is detected using the above- The position of the grating corresponding to the reflected light of the wavelength can be detected. That is, when the optical fiber is refracted, it is possible to detect the occurrence of the refraction at the portion where the lattice is located through the change of the wavelength spectrum.

Hereinafter, the principle of detecting the degree of refraction of the optical fiber will be described with reference to Figs. 13 and 14. Fig.

13 shows only the wavelength spectrum of the first reflected light polarized in the horizontal axis (x) direction for convenience of explanation. 14 shows the wavelength spectrum curve R1 corresponding to the case of FIG. 13 (a) and the wavelength spectrum curve R2 corresponding to the case of FIG. 13 (b).

13 (a) and 13 (b) show a case where the optical fiber 100 is refracted at the same point, but the degree of refraction is different. Figure 13 (a) shows a state of being more refracted compared to Figure 13 (b) (i.e., r1 < r2). In both cases, as shown in Fig. 14, it is confirmed that the curves R1 and R2 generate peaks at almost the same wavelength, but the peaks R are formed to be different from each other. Therefore, the degree of refraction of the optical fiber can be detected by analyzing the magnitude of the peak caused by the refraction.

Hereinafter, the principle of detecting the direction in which the optical fiber is refracted and the angle thereof will be described with reference to Figs. 7, 10, and 15. Fig.

According to this embodiment, in order to more accurately detect the refraction direction of the optical fiber, a change in refractive index due to refraction is considered together.

Lattice of the optical fiber Fig. 7 (g _a) in a position, when the refraction in the direction A in Figure 10, the grating (g _a) and the x-axis direction interval (Λ _x) and y-axis direction interval between the grid and the adjacent its (Λ _y are all reduced to substantially the same degree. On the other hand, as the optical fiber is substantially refracted in the x-axis direction, the optical fiber is elongated in the x-axis direction and the refractive index ( _x ) in the x-axis direction at the refraction position decreases as the density increases, (n _y ) is substantially maintained.

Therefore, the wavelength? _Ax of the reflected light in the x-axis direction by the grating g _a is entirely decreased, and as shown in Fig. 15 (a), the light having the wavelength? _Ax in the wavelength spectrum curve is the wavelength of the peak (P _1x) in the value R is reduced from (λ _ax), and the wavelength of the wavelength (λ _ax + △ λ _x) on the left side than (λ _ax) generated by size reduction.

Further, the light having a grating (g _a), the wavelength (λ _ay) at a wavelength spectrum curve as shown in Fig been reduced as a whole, Fig. 15 (b) the wavelength (λ _ay) in the y axis direction of reflected light by the It causes a decrease in the R value in the wavelength (λ _ay) by the size decreases, the peak wavelength (P _1y) in the wavelength (λ _ay + △ λ _y) on the left side than (λ _ay).

However, the left compared to the Equation 1 in accordance with the relationship, (λ _ax) the wavelength of the x-axis direction, the reflected light is the refractive index (n _x) (λ _ay) The reduction is reflected wave of the y-axis direction, the reflected light And has a characteristic of being further shifted. That is, | Δλ _x |> | Δλ _y |

On the other hand, when the optical fiber 100 is bent in the direction B in Fig. 10, the x-axis direction spacing Λ _x and the y-axis direction spacing Λ _{y of the} grating g _a and adjacent gratings ) Are all reduced to substantially the same degree, but the refractive index ( _x ) in the x-axis direction is substantially maintained and the refractive index ( _y ) in the y-axis direction is decreased. Accordingly, the wavelength (? _Ax ) of the reflected light in the x-axis direction and the wavelength (? _Ay ) of the reflected light in the y-axis direction by the grating (g _a ) have a relationship of | Δλ _x | <| Δλ _y | The phenomenon of shifting can be observed. With this difference, it is possible to distinguish the direction of refraction from direction A and direction B.

Light when the fiber is to be refracted in the direction C in Figure 10, the grating (g _a) and the x-axis spacing of the lattice (Λ _x) and y-axis direction interval (Λ _y) adjacent to that is that both increased substantially to the same extent . However, while the optical fiber is substantially As the refraction in the x-axis direction, the optical fiber is further extended in the x axis direction is increased to the x-axis direction refractive index (n _x) of the refractive position, y-axis direction refractive index (n _y) Is substantially maintained.

Therefore, although the wavelength? _Ax of the reflected light in the x-axis direction by the grating g _a and the wavelength? _Ay of the reflected light in the y-axis direction are all shifted to the right, the wavelength? _Ax of the reflected light in the x- Axis is further shifted to the right compared to the wavelength (λ _ay ) of the reflected light in the y-axis direction by reflecting the increase amount of the refractive index (n _x ).

On the other hand, when the optical fiber 100 to be refracted in the direction D of Figure 10, the grating (g _a) equal to the direction A and the x-axis spacing of the grating adjacent to the (Λ _x) and y-axis direction interval (Λ _y The refractive index n _{x in the} x-axis direction is substantially maintained and the refractive index n _y in the y-axis direction is increased. Therefore, it is possible to observe a phenomenon that the wavelength (lambda _ay ) of the reflected light in the y-axis direction by the grating (g _a ) shifts further to the right compared to the wavelength (lambda _ax ) of the reflected light in the x-axis direction. Using this difference, the directions of refraction in directions C and D can also be distinguished.

As described above, according to this embodiment it is the center of the core 120 is separated from the whole refractive heart sensor (100), x-axis spacing of the grid in accordance with the refraction of the optical fiber (100), (Λ _x) and axis direction spacing? _y is increased or decreased to substantially the same degree. Therefore, if the wavelength of the reflected light in the x-axis direction and the rate of change in the wavelength of the reflected light in the y-axis direction are analyzed, It will be understood that the direction can be distinguished and detected.

Furthermore, the angle at which the optical fiber is refracted can also be calculated.

For example, when the optical fiber is refracted in the direction A, the refractive index in the y direction is substantially maintained. Therefore, when Δλ _y is substituted in the equation (1) in the curve C _y in FIG. 15, _It is possible to calculate how far _a ) has moved from its original position. Thus, it is possible to know the displacement of lattice spacing by refraction of the optical fiber, the grating (g _a) is rotated can be calculated the angle.

The optical fiber 100 according to the present embodiment can measure not only the refracted position but also the refracted direction and the angle using the single fiber.

According to the present embodiment, the sensor 100 having the above-described configuration is formed inside the work robot 1. [

Figs. 16 to 18 schematically show the work robot 1 provided with the sensor 100. Fig. 17 and 18 show only the core 120 and the gratings of the sensor 100 for convenience of illustration.

16, the sensor 100 is inserted from the rear end of the body 3 of the work robot 1 to extend to the worker 2.

As described above, inside the body 3, the optical fiber is disposed so as to pass through the other portion of the center of the body 3, so that the center of the sensor 100 is spaced apart from the center of refraction.

The optical fiber of the sensor 100 may be inserted into the skin 4 (see FIG. 17) or adhered closely to the surface of the skin 4 on the manufacturer 2 so that the center of the sensor 100 is refracted (In the case of the skin (4), the center of the skin (4) will be the center of refraction).

The work robot 1 is coupled with a light source 91 for making incident light incident on the sensor 100 and an optical analyzer 92 for analyzing the wavelength spectrum of the reflected light output from the sensor 100. An optical distributor 93 for transmitting the reflected light output from the sensor 100 to the optical analyzer 92 may be further provided.

As shown in Fig. 17, the work shop 2 of the work robot 1 includes a skin 4 of elastically deformable material. The optical fiber of the sensor 100 is formed so as to pass through all the surfaces of the worker 2.

According to the present embodiment, the first grid g ₁ to the a-th grid g _a are located inside the body 3 and then the a + 1-th grid g _{a +1} to the n-th grid g _{a +} Th grid (g _n ).

As described above, since the corresponding wavelength values of the reflected light for each grating are known, the wavelengths due to the gratings located inside the body 3 and the wavelengths due to the gratings located inside the maker 2 in the wavelength spectrum of the reflected light .

According to the present embodiment, it is detected from the change of the wavelength spectrum of the reflected light generated due to the change in the interval of the grid located inside the work shop 2 whether or not an external force acts on the small business 2, And detects the refraction state of the body 3 by detecting a change in the wavelength spectrum of the reflected light caused by the change in the interval of the grating located at

18, the elastic skin 4 deforms when an external force is applied to the object M for holding the object M or the like, and the sensor 100 Is partially refracted in correspondence with the shape change of the skin 4. When the optical fiber is refracted, the interval of the gratings located at the corresponding refraction portion changes, and a change that can be distinguished in the wavelength spectrum of the reflected light is detected.

Through the change of the wavelength spectrum, it is possible to detect whether the external force acts on the manufacturer 2 and the external force acting position. Further, it will be understood that the magnitude of the external force acting by using the refractive direction and the deflection angle of the optical fiber, the elastic deformation coefficient of the skin 4, and the like will also be detected.

On the other hand, when the elongated body 2 is bent as shown in Fig. 1, the optical fiber located inside the body 2 is refracted accordingly. Thus, the grids (g ₁ g _a ), it is possible to measure not only the refracted position of the body 2 but also the refracted direction and the angle thereof.

[Third Embodiment]

19 is a side view of an optical fiber 200 according to a third embodiment of the present invention.

The sensor 200 includes an optical fiber and a plurality of gratings formed inside the optical fiber.

The optical fiber includes a cladding 220 and a core 230. The refractive indices of the cladding 220 and the core 230 are different from each other.

The core 230 is formed with a plurality of lattice portions T ₁ to T _n each having a plurality of lattices. The gratings forming the grating portions are arranged at equal intervals from each other. The spacing (Λ ₁ to Λ _n ) of the three grids forming each grating (T ₁ to T _n ) has a gradually increasing relationship (ie, Λ ₁ <... <Λ _a < _n ). The spacing between each lattice is significantly greater than the spacing of the lattices forming the lattice (Λ ₁ , ... Λ _a , ... Λ _n ).

According to the above configuration, the incident light incident on the light inlet 250 of the optical fiber is interfered by the grating portions, and the reflected light output to the light inlet 250 has a wavelength spectrum as shown in FIG.

The wavelengths appearing in the wavelength spectrum in Fig. _{20 (λ 1, ... λ a} , ..., λ g) is the interval _{(Λ 1, ... Λ a,} ... Λ n) of the respective grid part a grid Which corresponds to the value obtained by substituting in Equation (1). In other words, the wavelengths (? ₁ , ...,? _A , ...,? _G ) indicate the wavelengths of the reflected light reflected by one of the grating portions.

When the optical fiber is refracted at the portion where the first grating portion (T ₁ T _n ) is located, the interval (L ₁ ) of the gratings constituting the first grating portion (T ₁ T _n ) will change, It is possible to observe that the curve for the wavelength? ₁ among the wavelength curves of FIG. 20 shifts to the left and right by the relationship of the formula ( ₁ ). It can be seen that the optical fiber is refracted at the first lattice position if it is observed that the curve for wavelength lambda ₁ shifts to the left and right.

On the other hand, by forming a plurality of sensors having the same configuration as that of the sensor 200 and using the wavelength spectrum change of the reflected light for each sensor, it is possible to detect the refraction direction and the angle of the object on which the sensor 200 is formed.

The refraction direction and angle detection principle will be described below with reference to Fig.

21, in order to make the center of the two sensors 200 ', 200 "be spaced apart from the center of refraction of the entire sensor, the body 3 of the work robot 1 The two sensors 200 'and 200' 'are the same sensors as the sensor 200. In order to distinguish the two sensors 200' and 200 'from each other, Prime (') and double prime (") are displayed.

In FIG. 21, when the body 3 is refracted in the E direction, the lattice spacing of the lattice portion located at the refracting portion of the sensor 200 'decreases. Therefore, the curve of the wavelength spectrum of the reflected light shown in FIG. The phenomenon of moving to the left side can be detected. On the other hand, when the body 3 is refracted in the direction F, the movement of the wavelength spectrum curve will be opposite to the above.

On the other hand, when the body 3 is refracted in the G direction, the lattice spacing of the lattice portion located at the refraction portion of the sensor 200 " decreases, and thus the curve of the corresponding wavelength in the wavelength spectrum curve of the reflected light is shifted to the left In the case of refraction in the H direction, the shift of the wavelength spectrum curve will be opposite to the above.

By using this principle, it is possible to know the refracted direction by analyzing the wavelength change of the reflected light output from each of the plurality of sensors.

Also, by analyzing the changes in the reflected light wavelengths of the two sensors 200 'and 200 ", it is possible to detect the refraction direction even when the body 3 is refracted in any direction between the directions E and G, for example .

Further, as described in the foregoing embodiment, by substituting the wavelength change value?? For each optical fiber into the above-mentioned expression (1), the displacement of the lattice portion of the optical fiber can be calculated, Can be calculated.

According to the present embodiment, the two sensors 200 ', 200 "are formed inside the work robot 1.

22 to 24 schematically show the work robot 1 equipped with the sensor 200. [ 23 and 24 show only the core 220 and the gratings of the sensor 200 for convenience of illustration.

22, each of the two sensors 200 ', 200 "is inserted from the rear end of the body 3 of the work robot 1 and extends to the worker 2.

The work robot 1 is provided with a light source 91 for inputting incident light to the sensors 200 'and 200 "and an optical analyzer 92 for analyzing the wavelength spectrum of the reflected light output from the sensors 200' and 200" do. An optical splitter 94 for splitting the same light emitted from the same light source 91 and sending the same light to the two sensors 200 'and 200 ", respectively; and a reflected light output from each of the sensors 200' and 200" The optical distributor 93 may be further provided.

As shown in Fig. 23, the work shop 2 of the work robot 1 includes a skin 4 of elastically deformable material. The optical fiber of the sensor 200 'is formed so as to pass through all the surfaces of the upper end of the workpiece 2 and the optical fiber of the sensor 200' 'is formed to pass through all the surfaces of the lower end of the workpiece 2'.

According to the present embodiment, the sensor 200 'includes a first grid portion T' ₁ to an a-th grid portion T ' _a positioned inside the body 3, and then a + 1 And the n-th lattice portion (T ' _n ) is located from the lattice portion (T' _{a + 1} ). Similarly, the sensor 200 '' has the first grid portion T '' ₁ to the a 'th grid portion T'' _a located in the body 3, and then the a + 1' (T " _{a + 1} ) to the nth lattice portion (T" _n ).

As described above, since the wavelength values of the reflected light to the respective grating portions are known, the wavelengths of the gratings located in the body 3 and the gratings located inside the body 2 of the body 3 in the wavelength spectrum of the reflected light, .

According to this embodiment, similarly to the second embodiment, it is detected from the change of the wavelength spectrum of the reflected light generated due to the change in the interval of the grating located inside the small company 2 whether or not the external force to the small company 2 acts And detects the refraction state of the body 3 by detecting a change in the wavelength spectrum of the reflected light generated due to the change in the interval of the gratings located inside the body 3.

24, when the external force is applied to the skin 4 for holding the object M or the like, the shape of the skin 4 is deformed. As a result, the sensor 200 ', 200''are partially refracted corresponding to the shape change of the skin 4. When a part of the optical fibers is refracted, the grating portions (T' _{n -1} , T ' _n , T " _n-1 , T" _n ) is changed, and a change that can be distinguished in the wavelength spectrum of the reflected light is detected.

Through the change of the wavelength spectrum, it is possible to detect whether the external force acts on the manufacturer 2 and the external force acting position. Further, it will be understood that the magnitude of the external force acting by using the refractive direction and the deflection angle of the optical fiber, the elastic deformation coefficient of the skin 4, and the like will also be detected.

On the other hand, when the elongated body 2 is bent as shown in Fig. 1, the optical fiber located inside the body 2 is refracted accordingly. Therefore, it is possible to measure not only the refracted position of the body 2 but also the refracted direction and the angle thereof through the wavelength change of the reflected light by the grid portions located inside the body 2, as described above.

Although two sensors 200 'and 200 "are described in the present embodiment, the number of sensors 200' and 200" may be increased as needed. At this time, the sensors 200 'and 200' 'can be arranged at 90 degrees from each other within the worker 2 to increase the efficiency. It is to be understood that the number of grids forming the grating portion may be two or more .

Claims (8)

1. A work robot inserted in a work space for performing work,
A manufacturer for performing a predetermined task;
A body extending from a rear end of the worker;
And a sensor coupled to the manufacturer and the body,
The sensor includes:
An optical fiber passing through the inside of the body and extending to the vendor,
And a plurality of gratings disposed in the optical fiber in the longitudinal direction of the optical fiber,
Wherein the optical fiber positioned on the workpiece is bent according to an external force when the shape of the workpiece is changed,
The optical fiber located inside the body refracts when the body is refracted,
Incident light incident on a light entrance of the optical fiber is interfered with and reflected by the plurality of gratings and is output as reflected light through the light entrance,
Detecting a change in the wavelength spectrum of the reflected light caused by a change in the interval of the grating caused by the refraction of the optical fiber positioned on the worker to detect whether an external force acts on the worker,
Wherein a refractive state of the body can be detected by detecting a change in a wavelength spectrum of reflected light caused by a change in the interval of the grating due to the refraction of the optical fiber located inside the body. delete The method according to claim 1,
(N &gt; = 2, natural numbers) are formed in the optical fiber to form a lattice portion of the strand,
In one lattice portion, n lattices are arranged at equal intervals,
And the intervals between the gratings of the grating portions are different from each other in the grating portion. The method of claim 3,
A plurality of sensors are provided,
The optical fibers of each of the plurality of sensors are arranged such that,
And a plurality of second protrusions, which are spaced apart from the longitudinal center axis of the body,
And are arranged at different positions with respect to the vendor so as not to overlap each other. The method according to claim 1,
Wherein the plurality of gratings are disposed at mutually different intervals,
Wherein the reflected light output to the light inlet of the optical fiber includes first and second reflected lights polarized in different directions, and the first reflected light and the second reflected light form different wavelength spectrums. robot. The method of claim 5, wherein
Wherein the distance between the plurality of gratings increases or decreases as a distance from the light entrance increases. The method according to claim 1,
Wherein the worker has an elastic deformable skin,
Wherein the optical fiber is inserted into the skin or attached to the skin. The method according to claim 1,
Wherein the work robot is an insertion-type robot inserted into the body and performing a minimally invasive procedure.

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