JPH07270118A - Position detection apparatus - Google Patents

Abstract

PURPOSE:To detect the arbitrary position of an object while a laser light source and a camera are kept fixed. CONSTITUTION:Slit light sources 3, 4 which radiate crossed beams of slit light LS1, LS2 are installed, the beams of light are irradiated so as to stride end edges in different positions of an iron plate A1, and a camera 5 which images a position in which the beams of slit light are interrupted by the end edges is installed. A position detection unit 6 in which an interrupted position by the imaging of the camera 5 is compared with a preset regularly interrupted position and which detects a dislocation with reference to the regular position of the iron plate A1 is installed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position detecting device for detecting a three-dimensional position for detecting an edge position of an object, and more particularly, to stacking plate members on each other to form an edge of an upper plate member. The present invention relates to a welding device effective for detecting the position of a welding line that is an edge of an upper plate-shaped member in a welding device that welds along a wire.

[0002]

2. Description of the Related Art Conventionally, as a device for detecting a welding line, there is known one used in a laser welding device disclosed in Japanese Patent Laid-Open No. 3-258473. This conventional apparatus, as shown in FIG. 14, has a laser beam irradiating means 01 for irradiating a fan-shaped light, a camera 02 for photographing an irradiated portion of the fan-shaped light, and an image picked up by the camera 02 to process a welded portion 03.
And a data processing device 04 for detecting the position of the laser light irradiation means 01 for controlling the output of the laser light irradiation means 01 by comparing the brightness of the welded portion 03 with a reference value. It is characterized in that a section is provided. Reference numeral 05 in the figure is a welding torch.

[0003]

However, the above-mentioned conventional apparatus can detect the welding portion 03 corresponding to the position where the workpieces are butted, but the welding starting point and the welding ending point on the welding portion 03 are tertiary. There is a problem that it cannot be originally detected.

Incidentally, as an apparatus capable of three-dimensionally detecting the shape of an object, for example, Japanese Patent Laid-Open No. 4-12 is available.
A device described in Japanese Patent No. 7006 is known, and this device scans while irradiating a slit light of a laser from a side surface and an upper surface, and photographs it by a camera to read a three-dimensional shape. Therefore, it is necessary to scan the slit light, time is required for detection, and a means for moving the laser light source and the camera is required, resulting in an increase in size and cost of the device.

The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to make it possible to detect an arbitrary position of an object with a laser light source and a camera fixed. There is.

[0006]

In order to achieve the above-mentioned object, the position detecting device of the present invention is provided with a light irradiating means for irradiating a plurality of slit lights, and the light irradiating means comprises at least two light irradiating means. A slit light is configured to be radiated on the work whose position is to be detected in a direction in which the slit light itself or an extension line of the slit light intersects, and a camera for imaging the state of the slit light radiated on the work is provided. In the imaging of the camera when each slit light is radiated so as to straddle the edge of the work, the position where each slit light is interrupted at the edge of the work is the position when the work is arranged at the preset regular position. Positional deviation detection means is provided for detecting a positional deviation of the workpiece from the regular position by comparing a certain regular position with an imaging pointed position which is a position on imaging. It has a configuration that is.

It is preferable that the light irradiating means irradiates at least two slit lights in a direction orthogonal to the + or L shape on the work (claim 2). In that case, the positional deviation detection means, when one of the orthogonal directions is the y direction and the other is the x direction, the positional deviation Δy in the y direction with respect to the normal position of the work is calculated in the first slit light parallel to the y direction. It is calculated by subtracting the y-coordinate value y ₀₁ of the regular interruption position from the y-coordinate value y _p1 of the imaging interruption position, and the positional deviation Δx in the x direction with respect to the regular position of the workpiece is imaged in the second slit light parallel to the x direction. The value is calculated by subtracting the value x ₀₂ of the x coordinate of the regular interruption position from the value x _p2 of the x coordinate of the interruption position, and the positional deviation of the work is detected by this (claim 3).

Further, the light irradiating means and the camera are installed such that the irradiating direction of each slit light and the image pickup direction have a predetermined inclination angle α, and the position deviation detecting means is A distance a in the slit orthogonal direction between the regular interruption position and the imaging interruption position is obtained, and a value obtained by dividing the distance a by a tangent value (tan α) of the inclination angle α is orthogonal to the xy plane with respect to the regular position of the work. Alternatively, it may be detected as a positional deviation Δz in the z direction (claim 4).

In such a configuration, the positional deviation detecting means sets the coordinates of the image interruption position of the first slit light to (x _R1 , y _R1 , z _R1 ) and determines the image interruption position of the second slit light. When the coordinates are (x _R2 , y _R2 , z _R2 ), the turning angle θ _y of the workpiece about the y axis is θ _y = tan ⁻¹ [(z _R2 −z _R1 ) / (x _R1 −x _R2 )] may be calculated.

Further, the light irradiating means is configured such that one of the intersecting slit lights has a width d of a predetermined dimension, and the positional deviation detecting means is arranged on one side edge of the slit light having the width d. The coordinates of the break position are (x _R1 , y _R1 ,
z _R1 ), and the coordinates of the discontinuity position on the other side edge of the slit light are (x _R11 , y _R11 , z _R11 ), the turning angle θ _z of the workpiece about the z axis is θ _z = tan ^{− 1} [(y _R1 −y _R11 ) / d] may be calculated. Alternatively,
The light irradiating means configures one of the intersecting slit lights by two parallel slit lights having a predetermined distance d, and the positional deviation detecting means discontinues in one of the slit light having the distance d. The coordinates of the position are (x _R1 , y _R1 ,
z _R1 ), the coordinates of the interruption position in the other slit light may be (x _R11 , y _R11 , z _R11 ), and the rotation angle θ _z of the workpiece about the z axis may be obtained.

[0011]

In the position detecting device of the present invention, when the position of the work is detected, the two light beams from the light irradiating means are applied so as to straddle the two different edges of the work. In that case, each slit light is interrupted at the edge of the work.

The camera takes an image of the irradiation state of the slit light with respect to such a work, and the position shift detecting means detects the position where the slit light on the image is interrupted at the edge of the work and the preset normal interruption position and the imaging position. The position shift of the workpiece with respect to the normal position is detected by comparing with the image pickup interrupted position.

This position detection will be described more specifically. It is preferable that the two intersecting slit lights are orthogonal to each other (Claim 2). Let x be the x direction and y be the respective directions, and the coordinates of the regular interruption position for the first slit light parallel to the y direction be (x ₀₁ , y ₀₁ ), and the coordinates of the imaging interruption position be (x _P1 , y _P1 ), x The coordinates of the regular interruption position for the second slit light parallel to the direction are (x ₀₂ , y ₀₂ )
And the coordinates of the imaging interruption position are (x _P2 , y _P2 )
Then, the positional deviation Δx in the x direction with respect to the normal position of the work and the positional deviation Δy in the y direction with respect to the normal position.
Can be respectively calculated by the following arithmetic expressions (claim 3). Δx = x _P2 −x ₀₂ , Δy = y _P1 −y _{01 It is} preferable that each slit light and the camera are installed so that the irradiation direction and the imaging direction have a predetermined inclination angle α (claims 4). That is, below the outside of the edge of the surface of the workpiece that irradiates each slit light, if there is no member capable of reflecting the slit light,
The slit light irradiated to the outside of the edge is not imaged by the camera, each slit light will be interrupted at the edge of the work, and even when imaged by the camera from the same direction as the irradiation direction of the slit light, The position of interruption can be detected from the captured image. On the other hand, when there is a member that reflects the slit light below the outside of the edge of the workpiece, when the image is taken by the camera from the irradiation direction of the slit light, the slit light reflected by the workpiece and the outside It is difficult for a member to distinguish reflected light, and it is difficult to detect a break position. However, when an image is picked up by a camera from an oblique direction having an inclination angle α with respect to the irradiation direction of the slit light, the reflection position of the slit light on the surface of the work and the reflection position of the member outside thereof are different by sin α. Therefore, the discontinuity position can be determined.

Further, based on this, the distance a in the slit orthogonal direction between the regular interruption position and the imaging interruption position is detected in an arbitrary slit light, and is orthogonal to the xy direction of the work by the following formula. The positional deviation Δz in the z direction, which is the direction of movement, can be detected. Δz = a / tanα
The coordinates of the image interruption position of the first slit light are (x _R1 ,
y _R1 , z _R1 ) and the coordinates of the imaging interruption position of the second slit light are (x _R2 , y _R2 , z _R2 ),
The y-axis of the rotation angle theta _y of the workpiece can be detected by theta _y = tan ^-1 calculation formula of _{[(z R2 -z R1) /} (x R1 -x R2)].

Further, in the apparatus according to the sixth or seventh aspect, both side edges in the width direction of the slit light having the width d or the parallel slit lights having the interval d are different from each other, and the respective interruptions are different. The coordinates of the position are (x _R1 , y _R1 ,
z _R1 ) (x _R11 , y _R11 , z _R11 ), when the workpiece deviates from the normal position about the z axis, the direction of the value of d is the x axis direction. If there is y _R1 and y _R11
If the values of d are different and the direction of the value of d is the y-axis direction,
The values of x _R1 and x _R11 will be different.

Therefore, based on this difference, the turning angle θ _z of the workpiece about the z-axis is θ _z = tan ^-1 [(y _R1- y _R11 ) / d] or θ _z = tan ^-1 [( x _R1 −x _R11 ) / d].

[0017]

Embodiments of the present invention will be described with reference to the drawings. In the description of the embodiments, a case where the welding apparatus for irradiating a welding portion with laser light to perform welding is applied to an apparatus for detecting a welding line which is a welding portion of a work and its starting point will be described.

FIG. 1 is a diagram showing the entire position detecting apparatus of the first embodiment of the present invention. The apparatus of the first embodiment is a robot arm 1 provided at the tip of a welding robot (not shown).
Is attached to. That is, the welding robot is configured so that the robot arm 1 can be moved to an arbitrary position by a driving device (not shown). A welding torch 2 for irradiating a laser beam for welding is fixed to the tip of the robot arm 1. In this embodiment, the welding robot stacks two iron plates (workpieces) A1 and A2 on top of each other, and as shown in FIG. 2, the edge of one side of the upper iron plate A1 and the surface of the lower iron plate A2. This welding line RL is referred to as a welding line RL in the present specification, one end of this welding line RL is called a start point S, and the other end is called an end point F.

Returning to FIG. 1, the robot arm 1 includes
A first slit light source 3 and a second slit light source (light irradiating means) constituting the device of the first embodiment, and a camera (CCD camera) 5 using a charge coupled device are provided, and these are positions formed by a microcomputer. It is connected to a detection unit (positional deviation detection means) 6.

Each of the slit light sources 3 and 4 emits a long and narrow slit-shaped laser beam, and as shown in FIG.
The first slit light LS1 and the second slit light LS2 from the respective light sources 3 and 4 are installed so as to be orthogonal to each other in a substantially L-shape. Then, in this embodiment, the first slit light L
The longitudinal direction of S1 is the y direction, the longitudinal direction of the second slit light LS2 is the x direction, and the direction orthogonal to the x and y directions is the z direction. As will be described later, since the slit lights LS1 and LS2 are applied to the iron plates A1 and A2 in an oblique direction, the slit lights LS1 and LS2 are applied to the upper iron plate A1 and the lower iron plate A2. The position of the existing portion means that the position of the iron plate A1 is displaced in parallel due to the thickness of the iron plate A1, and a discontinuous portion occurs at the edge of the iron plate A1, and this position is referred to as a discontinuous position.

Further, as shown in FIG. 3, the camera 5 is arranged such that when the iron plate A1 is placed at a preset regular position, which will be described later, the camera 5 becomes horizontal with respect to the iron plate A1. It is fixed to. And in FIG.
As shown in FIG. 3, the light sources 3 and 4 and the camera 5 are installed such that the irradiation direction of the first slit light LS1 by the first slit light source 3 and the shooting direction C of the camera 5 are inclined by an inclination angle α _1. In addition, the irradiation direction of the second slit light LS2 from the second slit light source 4 and the shooting direction C of the camera 5 are inclined by an inclination angle α ₂ .

Next, the position detection control in the position detection unit 6 will be described.

In the apparatus of the first embodiment, both iron plates A1 and A2 are placed on a predetermined support and the lower iron plate A2 is placed.
Since one side is brought into contact with an abutting piece (not shown) to regulate the position, the positional deviation of the welding line RL, the start point S, and the end point F may occur only on the xy plane. It has become. Therefore, the position detection unit 6 of the first embodiment device
Are configured to detect only displacements on the xy plane.

First, the normal position will be described.
When the iron plate A1 is arranged at the regular position, the starting point S is
The point (0, 0) on the x, y coordinates, and the welding line RL is
It is a line of distance L on a straight line of y = 0, and the end point F is x,
It is a point (L, 0) on the y coordinate. Moreover, each slit light LS1 and LS2 is irradiated so as to straddle two different edges of the iron plate A1 at the time of position detection, and at the interruption position of the first slit light LS1 in the case of such irradiation. The coordinates of a certain first regular interruption position T1 are (x
₁ , 0), and the coordinates of the second regular interruption position T2 of the second slit light LS2 are (0, y ₂ ).

Next, the control flow of the position detecting unit 6 will be described with reference to the flowchart of FIG. 4. In step S1, the slit light sources 3 and 4 output the slit lights LS1 and L.
Irradiate S2.

In step S2, an image is taken by the camera 5, and in the subsequent step S3, the slit lights LS1 and LS are generated.
Discontinuity position on the image of the camera 5 of S2, that is, the first imaging discontinuity position P1, the second imaging discontinuity position P2
The coordinates (x _P1 , y _P1 ) (x _P2 , y _P2 ) are read.

In step S4, the coordinates of the starting point S are set to (x
_P2 , y _P1 ). That is, in the welding line RL of the iron plates A1 and A2 placed on the support table in the state shown in FIG. 5, the deviation Δx in the x direction from the regular position is the second regular interruption position T2 (0, y ₂ ) and 2 Imaging interruption position P2 (x
_P2 , y _P2 ) and the distance in the x direction is x _P2 −0, and therefore Δx = x _P2 . On the other hand, the deviation Δy in the y direction is the first regular interruption position T1 (x ₁ , 0)
Corresponds to the distance in the y direction between the first imaging interruption position P1 (x _P1 , y _P1 ) and this distance is y _P1 −0, so Δy = y _P1 . Therefore, the coordinates of the starting point S are (x
_P2 , y _P1 ). By the way, when the coordinates of the first and second regular interruption positions are respectively (x ₀₁ , y ₀₁ ) (x ₀₂ , y ₀₂ ), Δx = x _P2- x ₀₂ , Δy = y _P1- y ₀₁ Become.

In step S5, the starting point S has coordinates (x _P2 , y _P1 ) and the ending point F is a distance L from the starting point S in the x direction (that is, on the line of y = y _P1 ). Advanced position, ie, coordinates (x _P2 + L, y _P1 )
Is output to the welding robot, and the flow of the position detection control of the position detection unit 6 is completed.

The welding robot receiving this output,
The welding torch 2 coordinates (x _P2, y _P1) of the start point coordinates from _{S (x P2 + L, y} P1) is moved while projecting a laser beam for welding in the x direction to the end point F of the.

Therefore, the operation during welding will be described.
The iron plate A2 is placed on a support table (not shown), and the iron plate A1 is overlaid on the iron plate A2. After that, the robot arm 1 is moved onto both the iron plates A1 and A2, and the respective slit lights LS1 and LS2 move the edges of two different sides (in this embodiment, the two sides are orthogonal) of the iron plate A1. The slit light sources LS1 and LS2 are emitted from the slit light sources 3 and 4 so as to straddle them, and the camera 5 captures an image of the state from above.

In the position detection unit 6, the slit light LS1, LS2 is discontinued from the image picked up by the camera 5 at the edge of the iron plate A1 (that is, the first image pick-up discontinuous position P).
1, the second imaging interruption position P2) is obtained, and the starting point S is detected from this position. After that, the welding robot moves the welding torch 2 to a position above the starting point S, and further moves the welding torch 2 by a distance L in the x direction while irradiating the welding laser beam. As a result, the welding line R from the start point S to the end point F
Welding can be performed accurately along L.

As described above, in the first embodiment, the first and second slit light beams LS1 and LS2 are
The effect that the starting point S of the welding line RL can be detected simply by irradiating so as to straddle the edge of the upper iron plate A1 without scanning.

Next, another embodiment will be described, but the description of the same structure and operation as those of the first embodiment will be omitted, and only the differences will be described.

The second embodiment is an example in which the vertical shift (z direction) of both iron plates A1 and A2 is also detected. That is, in this second embodiment, both iron plates A1 and A2 are placed on a support base during welding, for example, when the iron plates A1 and A2 flow through the line while being held by a holding device (not shown). In the example of the case where it is not placed, in FIG.
1 and A2 are arranged below the regular position indicated by the imaginary line by Δz. In addition, FIG.
FIG. 6B shows, in a dotted line, the imaging state of both slit lights LS1 and LS2 by the camera 5 when the iron plates A1 and A2 are arranged downward by Δz as shown in FIG. Both slit light LS1, LS at the position
The imaging state of No. 2 is shown by a solid line. At this time, the coordinates of the first interruption position Q1 on the imaging are (x _Q1 , y _Q1 ) and the coordinates of the second interruption position Q2 are (x _Q2 , y _Q2 ). Has become.

In the second embodiment, the flow between step S3 and step S5 of the flow chart shown in FIG. 4 is different, and as shown in the flow chart of FIG. 7, in step S11 following step S3, The first imaging interruption position Q1 (x _Q1 , y _Q1 ) and the first regular interruption position T1 (x
The distance a ₁ in the x direction with respect to ( ₁ , 0) is calculated, and this distance a ₁ is obtained by the arithmetic expression of a ₁ = x _Q1 −x ₁ .
By the way, as shown in FIG. 6A, when the iron plates A1 and A2 are arranged below the normal position by Δz, as shown in FIG. 6B, the slit lights LS1 and LS2.
Is a ₁ , in the x and y directions, respectively, compared to the normal position.
It will be shifted by a ₂ .

In step S12, Δz is calculated by calculating Δz = a ₁ / tan α ₁ based on the distance a ₁ .

That is, as shown in FIG. 6A, the angle between the imaging direction C of the camera 5 and the irradiation direction of the first slit light LS1 is α ₁ , and the first imaging interruption position Q1 and the first regular interruption are provided. Since the distance from the position T1 is a ₁ , tan α
The relational expression of ₁ = a ₁ / Δz holds, and the above expression holds.

In step S13, the coordinates of the start point S are processed as (x _Q2 , y _Q1 , -Δz), and the flow advances to step S5.

As described above, in the second embodiment, the deviations of the welding line in the x, y and z directions, Δx, Δy and Δ.
The start point S can be accurately detected by detecting z.

By the way, the first and second regular interruption positions T
The coordinates of T1 and T2 are (x ₀₁ , y ₀₁ ) (x ₀₂ ,
y ₀₂ ), the coordinates of the starting point S are (x _Q2 −
x ₀₂ , y _Q1 −y ₀₁ , −Δz).

Next, a third embodiment will be described. In the third embodiment, the welding line RL is used even when the iron plates A1 and A2 are displaced about the x-axis and the y-axis.
The purpose is to accurately detect. However, in the present embodiment, even if the positions of the iron plates A1 and A2 are deviated about the x axis, the position of the welding line RL can be detected by detecting the positional deviation Δz in the z direction of the second embodiment. Therefore, in the position detection unit 6, a step of detecting the positional deviation θ _y about the y axis is added between step S12 and step S5 of the second embodiment in the control flow.

FIG. 8 shows the irradiation state of the respective slit lights LS1 and LS2 in the third embodiment. FIG. 8A is a plan view and FIG. 8B is an arrow view of FIG. Then
A positional deviation occurs in a state in which the iron plate A1 is rotated by an angle θ _y about the y axis so that the iron plate A1 intersects with a regular position shown by an imaginary line on the xy plane, and as a result, the first imaging interruption position R1 is lowered by z _R1 and the second imaging interruption position is z _R2
An example of the state in which it is lifted up will be described. In addition,
In this example, the coordinates of the first imaging interruption position R1 are (x _R1 ,
y _R1 , z _R1 ) and the coordinates of the second imaging interruption position R2 are (x _R2 , y _R2 , z _R2 ).

Therefore, as shown in the flow chart of FIG. 9, in step S21 subsequent to step S12, the angle θ _y is calculated by the following arithmetic expression.

Θ _y = tan ⁻¹ [(z _R1 −z _R2 ) / (x _R1 −x _R2 )] That is, in FIG. 8B, tan θ _y = z _R1 / b Therefore, θ _y = tan ⁻¹ (z _R1 / b) _{where, b = (x R1 -x R2} ) · z R1 / (z R1 -z R2) is above equation holds because a.

In the subsequent step S5, a signal indicating the starting point S and the ending point F is output. In this embodiment, the coordinates of the starting point S are (x _R2 , y _R1 , z _R2 ) and The end point F is a position advanced from the start point S by a distance L in the x direction rotated by an angle θ _y about the y axis.

Next, a fourth embodiment will be described. The fourth embodiment is an example in which it is also possible to detect the occurrence of positional deviation in a state where the iron plate is rotated around the z axis with respect to the regular position.

Therefore, in the fourth embodiment, the first slit light source 3 is constructed so that the first slit light LS1 has a predetermined width d as shown in the plan view of FIG. That is, when the brightness characteristic of the first slit light LS1 is shown in FIG.
As shown in (a), the lightness in the range of the width d is high. By the way, the first slit light source LS having such a configuration
1 can be configured by arranging a plurality of conventional slit light sources having the characteristics shown in FIG. 11B so as to be arranged as shown in FIG.

Further, in the fourth embodiment, in the position detecting unit 6, a step described later is added between step S21 and step S5 of the flowchart of the third embodiment.

That is, in step S31 of the flowchart shown in FIG. 12, the turning angle θ _z about the z axis is calculated by the following equation.

Θ _z = tan ⁻¹ [(y _R1 −y _R11 ) / d] The above formula will be described. First as shown in FIG.
The slit light LS1 is interrupted with a width d at the welding line RL (the edge of the upper iron plate A1). Therefore, the fourth
In the embodiment, the position of two points at both ends in the width direction (x direction) of the first imaging interruption position R1 is detected, and in the present embodiment, one of these two points is set as the first coordinate ( x _R1 , y _R1 , z _R1 ) (this corresponds to the first imaging interruption position R1 in the above embodiment), and the other is the second coordinate (x _R11 , y _R11 , z _R11 ). Therefore, ta
Since nθ _z = (y _R1 −y _R11 ) / d, the above equation holds.

In the subsequent step S5, signals indicating the start point S and the end point F are output. In this case, the start point S
Has coordinates (x _R2 , y _R1 , z _R2 ), and the end point F is rotated from the start point S by an angle θ _y about the y axis and is rotated by an angle θ _Z about the z axis. It is a position advanced by a distance L in the direction.

Next, a fifth embodiment will be described. In this embodiment, the control content of the position detection unit 6 is the same as that of the fourth embodiment, but the first slit light LS1 of the first embodiment is used.
When obtaining the first coordinate and the second coordinate having the width d with respect to the imaging interruption position R1, two slit lights LS1 and LS11 having an interval of the width d are irradiated as shown in FIG. That is, the first slit light source 3 is configured to emit two parallel slit lights LS1 and LS11.

Although the embodiment has been described above, the specific structure is not limited to this embodiment, and the present invention includes a design change and the like without departing from the gist of the invention.

For example, in the embodiment, the example used for detecting the position of the welding robot has been shown, but the point is that it can be used for general applications for detecting an arbitrary point of a work.

Further, in the embodiment, the flat iron plates A1 and A2 are shown as the work, but any work having an edge may be applied as the work.

In the embodiment, each slit light LS1,
An angle α ₁ between the irradiation direction of LS2 and the imaging direction of the camera 5,
Although α ₂ is added, as described in the description of the embodiment, both directions can be made common when only the deviation on the xy plane is detected as in the first embodiment.

In the embodiment, the iron plate A1 has an example in which the edge for setting the first break position and the edge for setting the second break position form a right angle. The angle formed is not limited to a right angle. In this case, each slit light, when straddling each edge,
It is preferable that the slit light is orthogonal to the edge of the work while the work is arranged at the regular position, but the slit light may be used as it is as shown in the embodiment. In this case, it is necessary to correct the tangent value of the angle formed by the edge and the slit light.

[0058]

As described above, in the position detecting device of the present invention, the light irradiating means for irradiating a plurality of intersecting slit lights is provided, and the slit lights straddle the edge of the work at different positions. A camera that captures the position where slit light is interrupted by this edge is provided, and the position of the work relative to the normal position is compared by comparing the position of the break in the image captured by this camera with the preset normal position. Since the positional deviation detecting means for detecting is provided, an arbitrary position of the work can be detected by one irradiation without causing the slit light to be searched, and an effect that an arbitrary position can be detected by a simple structure can be obtained.

That is, according to the third aspect of the invention, an arbitrary position on the xy plane having two orthogonal axes can be detected, and in the fourth aspect of the invention, it is further orthogonal to the xy plane. The position [that is, (x,
[y, z) coordinate position] can be detected, and in the invention according to claim 5, a deviation θ _y in the rotation direction about the axis in the y direction is the center.
The position on the coordinate of (x, y, z) can be detected, and in the invention according to claim 6 or 7, the deviation θ _z in the rotation direction about the axis in the z direction is added ( x, y,
The position on the coordinate of z) can be detected.

[Brief description of drawings]

FIG. 1 is an overall view showing a position detection device according to a first embodiment of the present invention.

FIG. 2 is a plan view showing an irradiation state of slit light by the device of the first embodiment.

FIG. 3 is a side view showing an irradiation state of the first slit light and an image pickup state of the camera of the first embodiment device.

FIG. 4 is a flowchart showing a flow of position detection control of the position detection unit of the first embodiment device.

FIG. 5 is an explanatory diagram showing a position detecting operation of the device of the first embodiment.

FIG. 6 is an explanatory view showing the operation of the second embodiment device,
(A) is a side view and (B) is a plan view.

FIG. 7 is a flowchart showing a main part of the flow of position detection control of the position detection unit of the second embodiment device.

FIG. 8 is an explanatory view showing the operation of the third embodiment device,
(A) is a side view and (B) is a plan view.

FIG. 9 is a flowchart showing a main part of the flow of position detection control of the position detection unit of the third embodiment device.

FIG. 10 is a plan view showing slit light of a fourth example device.

FIG. 11 is a brightness characteristic diagram of slit light, in which (a) is the slit light of the fourth embodiment, and (b) is the conventional or first and second slit light.
The slit light of the second and third embodiments, (c) show how to make the slit light of the characteristic of the fourth embodiment using the slit light of the conventional characteristic.

FIG. 12 is a flowchart showing a main part of the flow of position detection control of the position detection unit of the fourth embodiment device.

FIG. 13 is a plan view showing slit light of a fifth example device.

FIG. 14 is a perspective view showing a conventional technique.

[Explanation of symbols]

 3 1st slit light source (light irradiation means) 4 2nd slit light source (light irradiation means) 5 Camera 6 Position detection unit (positional deviation detection means) LS1 1st slit light LS2 2nd slit light A1 Iron plate (work) A2 Iron plate ( Work) T1 First regular interruption position T2 Second regular interruption position P1 First imaging interruption position P2 Second imaging interruption position Q1 First imaging interruption position Q2 Second imaging interruption position R1 First imaging interruption position R2 Second imaging interruption position

Claims (7)

[Claims] 1. A light irradiating means for irradiating a plurality of slit lights is provided, and the light irradiating means applies at least two slit lights to the slit light itself or an extension line of the slit light on a work whose position is to be detected. Is provided so as to irradiate in a direction intersecting with each other, and a camera for imaging the state of the slit light applied to the work is provided, and the imaging of the camera when each slit light is applied so as to straddle the edge of the work. In, in regard to the position where each slit light is interrupted at the edge of the workpiece, the regular interrupted position which is the position when the workpiece is arranged at the preset regular position is compared with the imaging interrupted position which is the position on imaging, and the workpiece is The position detecting device is provided with position deviation detecting means for detecting a position deviation from the regular position. 2. The position detection according to claim 1, wherein the light irradiating means is configured to irradiate at least two slit lights in a direction orthogonal to a + or L shape on the work. apparatus. 3. The positional deviation detection means, when one of the orthogonal directions is the y direction and the other is the x direction, the positional deviation Δy in the y direction with respect to the normal position of the work is the first slit parallel to the y direction. The value is calculated by subtracting the y-coordinate value y ₀₁ of the regular interruption position from the y-coordinate value y _p1 of the imaging interruption position in light, and the positional deviation Δx in the x direction from the regular position of the workpiece.
_Is obtained by subtracting the x-coordinate value x ₀₂ of the normal interruption position from the x-coordinate value x _p2 of the imaging interruption position in the second slit light parallel to the x-direction, thereby detecting the work position deviation. 3. The method according to claim 2, wherein
The position detection device described. 4. The light irradiating means and the camera are installed such that the irradiating direction of each slit light and the image capturing direction have a predetermined inclination angle α, and the position shift detecting means, in any slit light,
A distance a in the slit orthogonal direction between the regular interruption position and the imaging interruption position is obtained, and a value obtained by dividing the distance a by a tangent value (tan α) of the inclination angle α is orthogonal to the xy plane with respect to the regular position of the work. 3. The position difference Δz in the z-direction is detected as follows.
Alternatively, the position detection device according to item 3. 5. The position detecting device according to claim 4, wherein the position deviation detecting means sets the coordinates of the imaging interruption position of the first slit light to (x _R1 , y _R1 , z _R1 ) and The coordinates of the position where the slit light is captured are (x _R2 ,
y _R2 , z _R2 ), the rotation angle θ _y of the workpiece about the y axis is calculated by θ _y = tan ⁻¹ [(z _R2 −z _R1 ) / (x _R1 −x _R2 )] A position detecting device characterized by being obtained. 6. The position detecting device according to claim 4 or 5, wherein the light irradiating means is configured such that one of the intersecting slit lights has a width d of a predetermined dimension, and the position shift detecting means includes: The coordinates of the break position at one side edge of the slit light having the width d are (x _R1 , y _R1 , z
_R1 ), the rotation angle θ _z of the workpiece around the z axis is θ _z = tan ⁻¹ , where the coordinates of the interruption position on the other side edge of the slit light are (x _R11 , y _R11 , z _R11 ). A position detecting device characterized by being configured to obtain by the calculation of [(y _R1- y _R11 ) / d] or θ _z = tan ^-1 [(x _R1- x _R11 ) / d]. 7. The light irradiating means is composed of two parallel slit light beams with one of the intersecting slit light beams having a predetermined distance d, and the positional deviation detecting device is a slit having the distance d. The coordinates of the interruption position on one side of the light are (x _R1 , y _R1 , z
_R1 ) and the coordinates of the interruption position in the other slit light are (x _R11 , y _R11 , z _R11 ), and the rotation angle θ _z of the workpiece about the z-axis is obtained. The position detection device described.