JPH0352883B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement in a hole position detection device that automatically detects the position of a screw hole, liquid injection hole, etc. opened in an object to be detected. It is something.

(Prior Art) Conventionally, as this type of hole position detection device, as disclosed in Japanese Patent Application Laid-Open No. 58-211880, a detection body made by bundling the tips of a large number of optical fibers is mounted on a robot arm. After the detection object is roughly moved to the position of a hole opened in the object to be detected, such as a screw hole in an automobile instrument panel, by teaching the robot, in that state, the surface of the object to be detected near the hole is moved. The amount of reflected light is detected through each of the optical fibers, and based on the variation in the amount of reflection detected through each optical fiber, the object to be detected is shifted from the hole position of the object to the side where the amount of reflection is larger. Assuming that
A device is known in which the position of a hole in an object to be detected is detected by moving the detection object to the side where the amount of light reflected is small.

(Problems to be Solved by the Invention) However, in the conventional method described above, external light such as an indoor lighting lamp is used as a light source to generate reflected light on the surface of the object to be detected. The amount of reflected light that enters the optical fiber is greatly affected by the irradiation angle of the light source, and when the irradiation angle changes due to movement of the light source, for example, the amount of reflected light that enters the optical fiber changes accordingly. As a result, there was a problem that it was difficult to stably and always accurately detect the hole position.

The present invention has been made in view of the above, and its purpose is to divide the optical fibers constituting the above-mentioned detection body into two types, one for light emission and one for light reception, and to pass the light from the light source through the optical fiber for light emission. By irradiating the surface of the object to be detected and detecting the reflected light reflected from the surface of the object through the receiving optical fiber, the irradiation angle of the irradiated light to the surface of the object to be detected can be kept constant. The objective is to maintain the hole position so that the reflected light from the surface of the object to be detected stably enters the light-receiving optical fiber, thereby making it possible to always accurately detect the hole position.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a solution in which a large number of wafers are bundled in a shape that substantially corresponds to the opening of the hole opening into the object to be detected. A detection body made of a book optical fiber and movable along the surface of the object to be detected is provided. Among the optical fibers in the detection object, a part of the optical fibers whose tips are arranged concentrically with respect to the center of the detection object is used for light emission, and the surface of the detection object is irradiated through the optical fiber for light emission. Provide a light source to In addition, the remaining optical fiber whose tip is arranged concentrically with respect to the center of the detection object is used for light reception, and the reflected light from the irradiation light from the light source reflected on the surface of the detection object is transferred to the optical fiber for light reception. Reflected light detection means are provided for receiving and detecting reflected light through the reflector. Further, a moving direction calculation is performed to calculate a target direction in which the object to be detected should move based on output data output from the reflected light detection means, that is, data indicating variations in the amount of reflected light incident on each light-receiving optical fiber. and detection object moving means for moving the detection object in the target direction in response to the output of the movement direction calculation means.

(Function) With the above configuration, in the present invention, when the light source emits light while the detection object is roughly moved to the hole position of the detection object, the light from the light source passes through the light emitting optical fiber of the detection object. The irradiated light is irradiated onto the surface near the hole of the object to be detected, and the reflected light of this irradiated light on the surface of the object to be detected is sent to the reflected light detection means through each light receiving optical fiber of the object to be detected. Based on the output data from the reflected light detection means, the movement direction calculation means calculates the target direction in which the detection object should move.

In other words, the light irradiated from the tip of the light-emitting fiber of the object to be detected is reflected on the surface of the object to be detected, but is not reflected at the opening of the hole. The amount of reflected light that enters is smaller than that of the receiving optical fiber corresponding to the surface of the object to be detected, and the direction in which the receiving optical fiber on the side where the amount of reflected light is smaller is positioned relative to the center of the object to be detected. is calculated as the target direction in which the detection object should move.

Then, the detecting object moving means that receives the output from the moving direction calculating means moves the detecting object in the target direction, thereby positioning the detecting object at a position corresponding to the hole of the detected object.

In this case, the light emitting optical fiber and the light receiving optical fiber are arranged concentrically with respect to the center of the detecting object and are integrated into the detecting object, so the light emitting optical fiber is passed from the light source to the detecting object. As a result, the irradiation angle of the light irradiated onto the surface of the object to be detected is always kept constant, and the reflected light from the surface of the object to be detected is stably incident on each receiving optical fiber. Therefore, the hole position of the object to be detected can always be accurately detected.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 1 schematically shows the overall configuration of a hole position detection device according to an embodiment of the present invention, W is a detected object which is an object of the hole position detection device, and the detected object W has a screw hole. A circular hole _W1 such as a liquid inlet hole or the like is opened.

Reference numeral 1 denotes a detection body (sensor) attached to the tip of an arm of a robot (not shown), and each tip of the detection body 1 is connected to the detected object W as shown in enlarged detail in FIG. A large number (seven) of optical fibers 2 are bundled into a circular shape approximately corresponding to the opening of the hole W ₁ and fixedly supported as one body by a cylindrical support portion 4.
3, 3, . . . and are provided movably along a two-dimensional X-Y coordinate plane parallel to the surface of the object W to be detected.

Optical fibers 2, 3, 3, in the detection object 1,
As shown by the shaded area in FIG. One of the optical fibers 2 is set as a light-emitting optical fiber, and its tip is arranged around the light-emitting optical fiber 2 at a constant angular interval (60°) with respect to the center Os of the detection object 1. The remaining six optical fibers 3, 3, . . . arranged concentrically are set as optical fibers for light reception. The light-emitting optical fiber 2 is connected to a light-emitting diode 5 as a light source, and is configured to irradiate the light emitted from the light-emitting diode 5 onto the surface of the object W through the light-emitting optical fiber 2. There is. On the other hand, the light-receiving optical fibers 3, 3, . . . are connected to phototransistors 6, 6, . A reflected light detection means 7 is configured to receive and detect reflected light that is received and reflected on the surface of the object W to be detected through light receiving optical fibers 3, 3, . . .

The output signal of each phototransistor 6 in the reflected light detection means 7 is inputted to an amplifier 8 and amplified, and then inputted to an A/D converter 9 and converted from an analog signal to a digital signal. The output of the A/D converter 9 is input to a microcomputer 10 (CPU), and this microcomputer 10 detects the positional deviation of the detection object 1 with respect to the detection object W hole _W1 position.
In response to the detected positional deviation, the system calculates the target direction in which the object 1 should move and outputs control data to the robot to move the object 1 in the calculated target direction. ing.

Here, furthermore, the microcomputer 1
Regarding the signal processing procedure performed in 0.
This will be explained in detail using the flowchart shown in the figure.
First, in step _S1 , the robot is taught to count the rough position of the hole _W1 of the detected object W as data, and then in step _S2 , the robot operates to set the detecting object 1 (sensor) at the tip of its arm in advance. It is moved to a reference hole set to correspond to hole W ₁ of the object W to be detected and positioned there. After that, in step _S3 , the light emitting diode 5 is made to emit light and the light is irradiated to the reference hole through the light emitting optical fiber 2, and the reflected light of the irradiated light near the reference hole is reflected through each light receiving fiber 3. Detection is performed by each phototransistor 6 of the photodetection means 7, and each phototransistor 6
A/D conversion value by the A/D converter 9 of the output of
CHn (n=1 to 6) is stored as a coefficient value Kn=1/CHn.

After that, proceed to step _S4 and repeat the above steps.
Operate the robot while teaching and playing back based on the data input in _S1 .
The detection object 1 is moved near the hole W ₁ of the object W to be detected.
In the next step _S5 , the same process as in step _S3 is performed to determine the A/D converted value of the output signal of each phototransistor 6 for the hole _W1 of the object W.
In addition to detecting CHn, each A/D of the actual measurement
Multiply the converted value CHn by each coefficient Kn for the reference hole stored in step _S3 above to get the vector An=
Set Kn×CHn (n=1 to 6). As shown in FIGS. 4a and 4b, this vector An is located at the center of the detecting object 1 on the
It is displayed to extend from Os in the direction in which each light receiving optical fiber 3 is located, and the position chart (Xn, Yn) of its tip is Xn=sin {60° (n-1)}×An, Yn=
It is expressed as cos {60°(n-1)}×An.

After this, in step _S6 , the target direction in which the detection object 1 should move is determined by the coordinate components (Xn, Yn) of each vector An set above, that is, each vector
Based on the direction from the origin Os (O, O) of the center of gravity C that synthesizes A ₁ to A ₆ , the target point P (X, Y) (tap) is symmetrical on the opposite side to the origin Os of the center of gravity C. X
= ₆ 〓 ⁱ⁼¹ (-Xi), Y= ₆ 〓 ⁱ⁼¹ (-Yi)).

Next, in step _S7 , it is determined whether the magnitude of the vector in the direction calculated above is within the experimental value ε.
In other words, the coordinate components X, Y of the target point P(X, Y) are X ²
It is determined whether the formula +Y ² ≦ε ² is satisfied, and if this determination is NO, the detection object 1 is located in the hole of the detected object W.
Assuming that the state has not yet corresponded to the _W1 position, the process proceeds to step _S8 , and the target point P(X,
Multiply each coordinate component X, Y of Y) by the experimental value k to set a new target point P (kX, kY), and then
A signal indicating the moving direction of the detection object 1 is sent to the robot so that it is directed toward (kX, kY), and then the process returns to step _S5 and repeats steps _S6 , _S7 , and so on.

On the other hand, the determination in step _S7 above is X ² +Y ² ≦ε ²
When YES, the detection object 1 is in the hole of the detection object W.
Assuming that the position corresponds to W ₁ , step
Proceed to _S9 , and the sensing of the hole _W1 by the detection object 1 is completed.

Therefore, in this embodiment, in steps S ₁ to S ₆ in the above flowchart, the moving direction calculating means 11 calculates the target direction in which the detection object 1 should move based on the output data of the reflected light detecting means 7. configured. Further, the robot supporting the detection object 1 constitutes a detection object moving means that receives the output of the movement direction calculation means 11 and moves the detection object 1 in the target direction.

Therefore, in the above embodiment, the detection object 1 is positioned in the reference hole by the operation of the robot,
In this state, the light emitting diode 5 is supplied with power, and the light from the light emitting diode 5 passes through the light emitting optical fiber 2 and is irradiated onto the reference hole, and the reflected light near the reference hole of the irradiated light is transmitted to each light receiving light. The light is detected by the phototransistor 6 through the fiber 3, and data of the reference hole is stored based on the amount of light received by each phototransistor 6.

Thereafter, the detection object 1 is moved to the vicinity of the target hole W ₁ of the object W to be detected, and in that state, the light emitting diode 5 irradiates the hole W ₁ with light and the irradiation process is performed in the same manner as above. Detection processing of the reflected light from the corresponding hole _W1 portion is performed by each phototransistor 6, and the data on the variation in the amount of light received by each phototransistor 6 is compared with the stored data of the reference hole. Based on this comparison, the target direction in which the detection object 1 should move is calculated, and a data signal regarding the target direction is input to the robot, and the detection object 1 is moved in the target direction by the operation of the robot. By repeating this, the detection object 1 is positioned at a position corresponding to the hole W ₁ of the object W to be detected, and the position of the hole W ₁ is detected. still,
After such detection, the robot inserts a fastening bolt, liquid injection pipe, etc. into the detected hole _W1 , and performs fastening work, liquid injection work, etc.

In this case, the detection object 1 includes the tip of the light emitting optical fiber 2 and the light receiving optical fibers 3, 3, . . .
are arranged concentrically with respect to the center Os of the detection object 1 and are integrally bundled, and the light from the light emitting diode 5 is irradiated into the hole W ₁ of the detection object W through the light emitting fiber 2. At the same time, the reflected light from the hole _W1 of the irradiated light is transmitted to the receiving optical fiber 3,
3,... through phototransistors 6, 6,...
... is detected, and the phototransistor 6, 6,
Since the hole W ₁ position is detected due to variations in the amount of reflected light incident on ..., the light from the light-emitting optical fiber 2 is always irradiated onto the hole W ₁ portion of the object W at a constant irradiation angle. As a result, stable reflected light that is less affected by external light whose irradiation angle changes is incident on each light-receiving optical fiber 3, so that the hole _W1 position of the object W to be detected is always kept stable. Can be detected accurately.

In addition, the hole W ₁ of the detection object 1 is determined based on the variation in the amount of reflected light incident on each light-receiving optical fiber 3.
In order to detect a positional deviation from the position and move the detection object 1 directly in the target direction with the direction opposite to the positional deviation as the target direction, a proximity sensor etc.
Unlike when detecting the _W1 position, there is no need to move the sensor vertically and horizontally, and the detection speed of the hole _W1 position can be increased to shorten the detection time. Moreover, since the target direction in which the object 1 should move is calculated based on the data on the variation in the amount of reflected light detected by each phototransistor 6, data can only be sent and received in one direction from each phototransistor 6 to the computer 10. Thus, the interface to the computer 10 can be simplified.

Furthermore, the data of the reference hole is once stored as a coefficient by the detection object 1, and when the actual hole _W1 position is detected, the count value of each phototransistor 6 is multiplied by each of the above coefficients for correction. Even if the tip of the hole 3 is dirty, the hole position can be detected with high accuracy.

In the above embodiment, as shown in FIG.
Place the light-emitting optical fiber 2 of the book at the center Os of the detection object 1,
Six light-receiving optical fibers 3, 3, ... are arranged around the light-emitting optical fiber 2, but for example, as shown in FIG. ... are arranged in a ring shape concentrically with the center Os of the detection body 1', and the ten light emitting optical fibers 2, 2, ... connected to the same light emitting diode are connected to the light receiving optical fibers 3, 3, ... ... The optical fibers 2 and 3 for light emission and light reception may be arranged in a concentric ring shape with respect to the detection body center Os on the outer periphery of the detection body, and the arrangement of the optical fibers 2 and 3 for light emission and light reception may be reversed from that in the above embodiment. In addition, as shown in Fig. 6, six light-emitting optical fibers 2, 2, ... connected to the same light-emitting diode are connected to the center of the detection object 1''.
The light emitting optical fibers 2, 2, . . .
6 groups of 4 fibers in one group, that is, 24 light-receiving optical fibers 3, 3, . . . are arranged in a ring around the It may be connected to the same phototransistor, and the target hole W ₁
It can be changed as appropriate depending on the size, shape, etc.

(Effects of the Invention) As described above, according to the hole position detection device of the present invention, a detection body is provided in which the tips of the optical fibers for light emission and light reception are arranged concentrically and bundled together, While the light from the light source is irradiated onto the surface of the object to be detected through the optical fiber for light emission, the reflected light of the irradiated light on the surface of the object to be detected is detected through the optical fiber for light reception. By determining the deviation of the detection object from the hole position and moving the detection object to the hole position,
Since the irradiation angle of the irradiation light from the light emitting optical fiber can always be kept constant, the hole position of the object to be detected can be detected stably and accurately.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is a schematic diagram showing the overall configuration, FIG. 2 is an explanatory diagram showing the arrangement of optical fibers at the tip of the detection object, and FIG. 3 is a processing procedure in the control system. Flowchart diagram showing the 4th
The figure is a characteristic diagram for calculating the target direction in which the detection object should move. FIGS. 5 and 6 are views corresponding to FIG. 2, respectively, showing modified examples of the arrangement of the optical fibers at the tip of the detection body. 1, 1', 1''... Detection body, 2... Optical fiber for light emission, 3... Optical fiber for light reception, 5... Light emitting diode, 6... Phototransistor, 7... Reflected light detection means, 11... ...Movement direction calculation means, W...
Object to be detected, W ₁ ...hole.

Claims (1)

[Claims] 1. A detecting body, which is made up of a large number of optical fibers bundled in a shape that each tip portion approximately corresponds to the opening of a hole opening in the detected object, and is movable along the surface of the detected object; and the detecting body. A light source that irradiates light onto the surface of an object to be detected through some of the optical fibers whose tips are arranged concentrically with respect to the center of the object to be detected; a reflected light detection means that receives and detects the reflected light reflected on the object surface through the remaining optical fiber whose tip end is arranged concentrically with respect to the center of the detection object; and based on the output data of the reflected light detection means. A hole characterized in that it is equipped with a moving direction calculation means for calculating a target direction in which the detected object should move, and a detected object moving means for receiving the output of the calculating means and moving the detected object in the target direction. Position sensing device.