JP5341490B2 - Coordinate position detection apparatus and coordinate position detection method - Google Patents

Description

  The present invention relates to a coordinate position detection apparatus and a coordinate position detection method for detecting a coordinate position of a target such as a laser welding point in teaching work performed prior to laser processing on a workpiece.

  Conventionally, prior to laser processing on a workpiece, a coordinate position of a target such as a laser welding point on the workpiece is calculated, and a teaching operation is performed using the calculated coordinate position of the target as teaching data. In machining, based on the teaching data, it is widely performed to perform predetermined laser machining by irradiating the workpiece with laser light from a machining head such as a remote laser irradiator.

  In Patent Document 1, a teaching device is attached after a machining head is removed from a robot arm during teaching work, and linear laser beams output from four laser irradiators in the sensing device are converted into four prisms. By crossing a point above the workpiece, the surface of the workpiece is irradiated with four laser beams intersecting the point as irradiation spots, and the surface of the workpiece including each irradiation spot is further irradiated with an imaging device. It has been proposed to take an image and display the image on a display.

  In this case, on the screen of the display, each irradiation spot, a cross line as a reference line and a reference circle centered on an intersection of the cross lines are displayed, and each irradiation spot is connected to the reference line. By irradiating the workpiece with a laser beam from the machining head so as to pass through the intersection point in the subsequent laser processing when the intersection with the reference circle is met, the optical axis of the laser beam for laser processing Is maintained properly.

Japanese Patent Laid-Open No. 63-259409

  However, in practice, it is difficult to specify a coordinate position of one point by intersecting a plurality of laser beams at one point. For example, when two linear laser beams intersect at one point, they do not intersect if they are at a twisted position.

  Therefore, (1) by obtaining the coordinates of two points through which one laser beam passes, or (2) by obtaining one point through which one laser beam passes and the angle formed by the one point and the laser beam. It is conceivable to specify the straight line itself indicated by the laser beam. However, in the case of (1), even if one point is fixed (specified), the coordinate component (three components) of the other point must be arbitrary, so one straight line (laser light) Requires 3 degrees of freedom. In the case of (2), even if one point is fixed, the angle needs to have a total of four degrees of freedom of two components.

  Therefore, when the four linear laser beams are crossed at one point above the workpiece as in Patent Document 1, it is difficult to specify the position of the one point as described above. Further, the configuration of the detection apparatus becomes complicated, for example, it is necessary to accurately control the irradiation of the laser beams so that the four linear laser beams intersect at one point.

  Furthermore, in the technique of Patent Document 1, during the teaching work, the processing head is detached from the arm attachment body and the detection device is attached, and the teaching operation is performed. After the teaching work, the detection device is removed and the arm attachment body is removed. Therefore, the burden on the operator increases.

  The present invention has been made in consideration of such problems, and detects the coordinate position of a target such as a laser welding point with a simpler configuration without removing the machining head from the arm attachment body during teaching work. It is an object of the present invention to provide a coordinate position detection apparatus and a coordinate position detection method that can be performed.

The coordinate position detection device according to the present invention is swingable, and at least three slit laser irradiators installed so that the planes of the respective slit laser beams are not parallel to each other, and the oscillation of each of the slit laser irradiators. possess the oscillation angle detecting means for detecting an angle, the one intersection by the plane of each slit laser beam to intersect with each other is formed by matching a target of the intersection and the surface of the workpiece, machining It is possible to perform laser processing on the workpiece that irradiates a laser beam to the intersection from a head .

In the coordinate position detection method according to the present invention, at least three slit laser irradiators are swung so that the planes of the slit laser beams are not parallel to each other, and the slit laser beams are respectively transmitted from the respective slit laser irradiators. by irradiating a first step of forming one of intersections the crossed planes of each slit laser beam to each other, a second step of detecting a swinging angle of each slit laser irradiator by rocking angle detecting means look including the door, by matching a target of the intersection and the surface of the workpiece, is characterized in that to enable laser processing for said workpiece is irradiated with a laser beam to the intersection from the machining head.

  According to these inventions, since the slit laser irradiator is swingable and the planes of the slit laser beams are not parallel to each other, the intersection of the planes of the slit laser beams is surely only one point. It is possible to easily match the intersection with a target such as a laser welding point. Therefore, the coordinate position of the target can be specified reliably by making the target coincide with the intersection.

  Thereby, compared with the technique of patent document 1, it becomes possible to detect the coordinate position of the target more easily without detaching the machining head from the arm attachment body during the teaching work, such as remote laser welding. These inventions can be easily applied to teaching operations for various laser processing.

  In addition, since the slit laser beam is used, when the slit laser beam is not orthogonal to the workpiece (not straight), a straight line formed on the surface of the workpiece by irradiation of each slit laser beam is used. The shape will appear distorted. Therefore, it is possible to easily determine visually whether each slit laser beam is perpendicular to the workpiece.

  According to the present invention, the slit laser irradiator is swingable and the planes of the slit laser beams are not parallel to each other. Can be easily matched with a target such as a laser welding point. Therefore, the coordinate position of the target can be specified reliably by making the target coincide with the intersection.

  Thereby, compared with the technique of patent document 1, it becomes possible to detect the coordinate position of the target more easily without detaching the machining head from the arm attachment body during the teaching work, such as remote laser welding. The present invention can be easily applied to teaching work for various laser processing.

  In addition, since the slit laser beam is used, when the slit laser beam is not orthogonal to the workpiece (not straight), a straight line formed on the surface of the workpiece by irradiation of each slit laser beam is used. The shape will appear distorted. Therefore, it is possible to easily determine visually whether each slit laser beam is perpendicular to the workpiece.

  Hereinafter, a preferred embodiment of the coordinate position detection apparatus according to the present invention in relation to a coordinate position detection method will be described with reference to FIGS.

FIG. 1 is a perspective view showing an arrangement of slit laser irradiators 20a to 20c constituting a coordinate position detection apparatus 40 (see FIG. 3 ) according to an embodiment of the present invention.

  As shown in FIG. 1, servo motors 14a to 14c are arranged on the bottom surface (front surface in FIG. 1) of a table 10 supported by a support member (not shown) via three fixing members 12a to 12c, respectively. ing. Slit laser irradiators 20a to 20c are attached to the tips of the rotation shafts 16a to 16c of the servo motors 14a to 14c, respectively, and the rotation shafts 16a to 16c are centered about the axial direction under the drive action of the servo motors 14a to 14c, respectively. By rotating, the slit laser irradiators 20a to 20c swing around the axial direction.

  Moreover, the slit laser irradiators 20a to 20c respectively irradiate line laser beams (slit laser beams having fan-shaped planes) 22a to 22c that expand in a fan shape around the optical axes 18a to 18c. In this case, each of the slit laser irradiators 20a to 20c is directed toward the lower side of the hole 24 formed in the table 10 so that the planes (normal lines) of the line laser beams 22a to 22c are not parallel to each other. When the light beams 22a to 22c are respectively irradiated, the line laser beams 22a to 22c intersect with each other to form one intersection point 26. That is, the intersection point 26 is a point formed by intersecting three planes (three planes in a substantially triangular shape that expands in a fan shape) formed by the line laser beams 22a to 22c, respectively.

  When a workpiece (not shown) is disposed below the table 10, straight lines 25a to 25c (shown by broken lines in FIG. 1) are formed on the surface of the workpiece by irradiation with line laser beams 22a to 22c. The intersection of the straight lines 25a to 25c is the intersection 26.

  Here, the fact that only one intersection point 26 is formed by the intersection of the line laser beams 22a to 22c and the coordinate position of the intersection point 26 can be specified will be described with reference to FIGS. 4A to 4C.

  In order to specify an arbitrary point (intersection point 26) in the three-dimensional space, it is necessary to fix the degrees of freedom of the three components x, y, and z in the three-dimensional space (to eliminate the degrees of freedom).

  For example, as shown in FIG. 4A, an arbitrary plane 60a in the three-dimensional space (a plane simulating the line laser beam 22a) has two degrees of freedom, while the straight line 62 has one degree of freedom. Therefore, when the planes 60a and straight lines 62 that are not parallel to each other intersect to form an intersection point 64, the intersection point 64 can eliminate the degree of freedom. That is, the coordinate position of the intersection 64 can be specified.

  On the other hand, as shown in FIG. 4B, when two planes 60a and 60b (planes simulating the line laser beams 22a and 22b) that are not parallel to each other in the three-dimensional space are intersected, a straight line 66 is formed. The straight line 66 has one degree of freedom.

  Next, as shown in FIG. 4C, if three planes 60a to 60c (planes simulating the line laser beams 22a to 22c) that are not parallel to each other in the three-dimensional space are intersected, one intersection 68 is obtained at the intersected portion. Is formed. That is, the coordinate position of the intersection 68 having no degree of freedom can be specified.

  Therefore, as shown in FIG. 4C, one intersection 68 formed by the intersection of three planes 60a to 60c that are not parallel to each other has three line laser beams 22a to 22a that are not parallel to each other (normal lines thereof). 22c corresponds to one intersection 26 (see FIG. 1) formed by intersecting. Therefore, it is possible to perform a coordinate position calculation process in the processing unit 52 described later with respect to the intersection point 26 with a fixed degree of freedom.

  Returning to FIG. 1, the servo motors 14 a to 14 c are attached to the motors 28 a to 28 c that rotate the rotation shafts 16 a to 16 c around the axial direction, and the rotation amounts of the rotation shafts 16 a to 16 c. And rotary encoders 30a to 30c that output the swing angles of the corresponding slit laser irradiators 20a to 20c.

  As shown in FIG. 2, a processing head 34 is disposed on the upper surface of the table 10 via a support member 32. After the teaching work for forming the intersection point 26 by irradiation of the line laser beams 22a to 22c is completed, the processing head 34 performs laser processing on the workpiece by irradiating the intersection point 26 with the laser beam 38 through the hole 24. It is possible.

  FIG. 3 is a schematic block diagram of the coordinate position detection apparatus 40 according to this embodiment.

  The coordinate position detection device 40 is a device for detecting the coordinate position of a target (intersection point 26) such as a laser welding point in the teaching work performed prior to the laser processing. In addition to 14a to 14c and slit laser irradiators 20a to 20c (see FIG. 1), a teaching device 42 including a computer that performs teaching work is included.

  The teaching device 42 includes a control means 44 as a computer main body, an input means 46 such as a mouse and a keyboard, a storage means 48 as a storage device or an external storage device in the computer main body, and an output means 50 such as a display or a printer. Consists of In addition, the control unit 44 includes a processing unit (calculation processing unit) 52 that executes a calculation process of the coordinate position of the target (intersection 26).

  Next, the operation (coordinate position detection method) of the coordinate position detection device 40 will be described with reference to FIGS.

  Here, the direction from the intersection 26 in FIG. 1 toward the bottom surface of the table 10 is defined as the z axis, and the directions along the bottom surface of the table 10 are defined as the x axis and the y axis.

  The coordinate position detection device 40 performs the following first work or second work during the teaching work.

  First, the first work will be described.

  In the first work, first, the operator operates the input means 46 to set the coordinate position (i, j, k) of the target and the slit laser irradiators 20a to 20c (where the rotary shafts 16a to 16c are attached). Coordinate positions (x1, y1, z1) to (x3, y3, z3) are input.

  Next, the processing unit 52 determines the swing angles φ1 to φ1 of the slit laser irradiators 20a to 20c based on the coordinate positions (i, j, k), (x1, y1, z1) to (x3, y3, z3). Calculate φ3.

  5A and 5B are schematic explanatory views showing the positional relationship between the target (intersection point 26) and points 70a to 70c indicating the slit laser irradiators 20a to 20c (attachment portions of the rotating shafts 16a to 16c in the slit laser irradiators 20a to 20c). 5A and 5B, the center position of the workpiece processing area in laser processing such as remote laser welding is defined as an origin O.

  As shown in FIGS. 1 and 5A, the slit laser irradiators 20a and 20b rotate (oscillate) around rotation axes 16a and 16b parallel to the x axis, respectively. Accordingly, the swing angles φ1 and φ2 of the slit laser irradiators 20a and 20b are respectively set so that the slit laser irradiators 20a and 20b rotate (swing) around the rotation axes 16a and 16b when the positive direction of the y-axis is 0 °. The angle when moving.

  As shown in FIGS. 1 and 5B, the slit laser irradiator 20c rotates (oscillates) about a rotation axis 16c parallel to the y-axis. Therefore, the swing angle φ3 of the slit laser irradiator 20c is an angle when the slit laser irradiator 20c rotates (swings) about the rotation axis 16c when the positive direction of the x axis is 0 °.

  Furthermore, the angles formed by the straight line connecting the origin O and the points 70a and 70b and the y-axis are θ1 and θ2, respectively, while the straight line connecting the origin O and the point 70c and the x-axis and the point 70c are The formed angle is θ3.

Here, the processing unit 52 uses the following equations (1) to (6) to slit from the coordinate positions (i, j, k), (x1, y1, z1) to (x3, y3, z3). The oscillation angles φ1 to φ3 and the angles θ1 to θ3 of the laser irradiators 20a to 20c are calculated.
θ1 = cos ⁻¹ {y1 / (y1 ² + z1 ² ) ^1/2 } (1)
θ2 = cos ⁻¹ {y2 / (y2 ² + z2 ² ) ^1/2 } (2)
θ3 = cos ⁻¹ {y3 / (x3 ² + z3 ² ) ^1/2 } (3)
cos (φ1-θ1) = {y1 × (y1-j) + z1 × (z1-k)}
/ [(Y1 ² + z1 ² ) × {(y1−j) ²
+ (Z1-k) ² }] ^1/2 (4)
cos (φ2−θ2) = {y2 × (y2−j) + z2 × (z2−k)}
/ [(Y2 ² + z2 ² ) × {(y2−j) ²
+ (Z2-k) ² }] ^1/2 (5)
cos (φ3-θ3) = {x3 × (x3-i) + z3 × (z3-k)}
/ [(X3 ² + z3 ² ) × {(x3−i) ²
+ (Z3-k) ² }] ^1/2 (6)

  The control unit 44 generates a control signal based on the swing angles φ1 to φ3 calculated by the processing unit 52 and outputs the control signal to the motors 28a to 28c, and an instruction signal for instructing the irradiation of the line laser beams 22a to 22c. It produces | generates and outputs to the slit laser irradiation devices 20a-20c.

  As a result, the motors 28a to 28c are driven based on the control signal. As a result, the rotation shafts 16a to 16c rotate by the swing angles φ1 to φ3 around the axial direction, so that the slit laser irradiators 20a to 20c. 20c swings by a swing angle φ1 to φ3. On the other hand, the slit laser irradiators 20a to 20c respectively irradiate line laser beams 22a to 22c that expand in a fan shape and are not parallel to each other around the optical axes 18a to 18c on the basis of the instruction signals. 22a-22c cross | intersect below the hole 24, and form the one intersection 26 on the surface of a workpiece | work (1st process). Therefore, the operator can confirm whether or not the intersection point 26 formed by the intersection of the line laser beams 22a to 22c and the target on the surface of the workpiece match. Further, the rotary encoders 30a to 30c detect the rotation amount (swing angle) of the rotary shafts 16a to 16c and output it to the control means 44 (second step).

  The output unit 50 calculates the coordinate positions (i, j, k), (x1, y1, z1) to (x3, y3, z3) output from the input unit 46 to the control unit 44, and the processing unit 52 calculates. The swing angles φ1 to φ3 and the angles θ1 to θ3 are displayed on a screen by a display or printed out by a printer.

  Next, the second work will be described.

  In the second operation, first, the operator operates the input unit 46 to input the coordinate positions (x1, y1, z1) to (x3, y3, z3) of the slit laser irradiators 20a to 20c.

  Next, the control means 44 generates a control signal and outputs it to the motors 28a to 28c, and also generates an instruction signal and outputs it to the slit laser irradiators 20a to 20c. Accordingly, the motors 28a to 28c are driven based on the control signal, and the rotary shafts 16a to 16c rotate around the axial direction to swing the slit laser irradiators 20a to 20c. Then, the slit laser irradiators 20a to 20c start irradiating the line laser beams 22a to 22c based on the instruction signal (first step). On the other hand, the rotary encoders 30a to 30c detect the rotation amounts (swinging angles) of the rotary shafts 16a to 16c and output them to the control means 44 (second step).

  When the operator confirms that the intersection point 26 formed by the intersection of the line laser beams 22a to 22c caused by the oscillation of the slit laser irradiators 20a to 20c coincides with the target on the surface of the workpiece. The input unit 46 performs an input operation for stopping the oscillation of the slit laser irradiators 20a to 20c, and the control unit 44 stops outputting the control signal and the instruction signal based on the input operation. In addition, the swing angle currently input from the rotary encoders 30a to 30c is regarded as the swing angles φ1 to φ3 when the target and the intersection 26 coincide with each other, and is output to the processing unit 52.

The processing unit 52 substitutes the swing angles φ1 to φ3 and the coordinate positions (x1, y1, z1) to (x3, y3, z3) into the following formulas (7) to (9) to obtain the coordinate position of the intersection 26. (I, j, k) is calculated, and the calculated coordinate position (i, j, k) of the intersection 26 is stored in the storage means 48 as the target coordinate position, that is, teaching data.
j = (y2 × tan ² φ1-y2 × tan ² φ2)
−tan φ1 × tan φ2 × | y1-y2 | (7)
k = z− | j−y2 | × | tan φ2 | (8)
i = x3-{(z3-k) / tanφ3} (9)

  Even in the second operation, the output means 50 outputs the coordinate positions (x1, y1, z1) to (x3, y3, z3) output from the input means 46 to the control means 44, and the swing angles φ1 to φ3. Alternatively, the coordinate position (i, j, k) calculated by the processing unit 52 is displayed on the screen by a display or printed out by a printer.

  As described above, according to the coordinate position detection device 40 and the coordinate position detection method according to this embodiment, the slit laser irradiators 20a to 20c are swingable and the planes of the line laser beams 22a to 22c (methods thereof). Line) is not parallel to each other, the plane intersection 26 of each line laser beam 22a to 22c is surely only one point, and the intersection 26 is a target such as a laser welding point. Therefore, if the processing unit 52 calculates the coordinate position (i, j, k) of the intersection point 26 based on the swing angles φ1 to φ3, the coordinate position (i, j, k) of the intersection point 26 is the target position. Coordinate position.

  Thereby, compared with the technique of patent document 1, at the time of teaching work, the coordinate position of a target can be detected more easily, without removing a processing head from an arm attachment body. Therefore, this embodiment can be easily applied to teaching work for various laser processing such as remote laser welding.

  Further, since the line laser beams 22a to 22c are used, when the line laser beams 22a to 22c are not orthogonal to the workpiece (not straight), the workpiece is irradiated with each line laser beam 22a to 22c. The shape of the straight lines 25a to 25c formed on the surface of the film will appear distorted. Therefore, it is possible to easily determine visually whether each line laser beam 22a to 22c is straight with respect to the workpiece.

  Further, by performing the teaching work by the first work, it can be easily confirmed whether or not the intersection point 26 and the target coincide. On the other hand, if the teaching work by the second work is performed, the teaching work can be performed efficiently.

  Further, the table 10 and the machining head 34 are configured as an integral unit, and during the teaching operation, the unit is moved to the vicinity of the workpiece by the operation of the robot arm, and then the first operation or the second operation is performed. 2 enables the teaching work to be performed without moving the machining head 34. After the teaching work, the teaching data is used to immediately perform remote laser welding or the like on the workpiece. Laser processing can be performed. Of course, even if the table 10 and the machining head 34 are separated and the table 10 and the machining head 34 are moved to the vicinity of the workpiece by the operation of the robot arm during teaching work, the above-described effects can be obtained.

  This embodiment is not limited to the above description, and can be freely changed to the following configuration.

  Instead of the above-described configuration in which the coordinate position detection device 40 automatically swings the slit laser irradiators 20a to 20c and detects the swing angles φ1 to φ3, for example, the output means 50 swings by screen display on a display. The moving angles φ1 to φ3 are displayed, the operator sees the contents of the screen display, the slit laser irradiators 20a to 20c are manually oscillated by the oscillating angles φ1 to φ3, and the slit laser irradiator after the oscillation is oscillated. The swing angles φ1 to φ3 of 20a to 20c may be measured by a protractor, and the measured swing angles φ1 to φ3 may be input by operating the input means 46.

  In this embodiment, the servo motors 14a to 14b and the slit laser irradiators 20a to 20c are arranged on the bottom surface of the table 10. However, the planes (normal lines) of the line laser beams 22a to 22c are mutually different. As long as the line laser beams 22a to 22c can be irradiated so as not to be parallel, the slit laser irradiators 20a to 20c are not limited to being arranged on one table 10, and any arrangement method may be used.

  Further, the servo motors 14a to 14b are also swingable in the z direction, while the slit laser irradiators 20a to 20c are also swingable with respect to the rotary shafts 16a to 16c, so It is possible to easily perform teaching work on the target.

  Note that the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted without departing from the gist of the present invention.

It is a perspective view which shows arrangement | positioning of a slit laser irradiation device. It is a front view which shows arrangement | positioning of a slit laser irradiation device and a processing head. It is a schematic block diagram of the coordinate position detection apparatus which concerns on this embodiment. 4A is an explanatory diagram showing a case where one plane intersects with one straight line, FIG. 4B is an explanatory diagram showing a case where two planes intersect, and FIG. 4C is a diagram where three planes intersect. It is explanatory drawing which shows the case where it does. 5A and 5B are schematic explanatory views showing the positional relationship between a target (intersection point) and a point indicating a slit laser irradiator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Table 12a-12c ... Fixing member 14a-14c ... Servo motor 16a-16c ... Rotary shaft 18a-18c ... Optical axis 20a-20c ... Slit laser irradiator 22a-22c ... Line laser beam 24 ... Hole 25a-25c, 62, 66 ... straight lines 26, 64, 68 ... intersections 28a-28c ... motors 30a-30c ... rotary encoder 32 ... support member 34 ... machining head 38 ... laser beam 40 ... coordinate position detection device 42 ... teaching device 44 ... control means 46 ... Input means 48 ... Storage means 50 ... Output means 52 ... Processing units 60a-60c ... Plane 70a-70c ... Point

Claims (2)

At least three slit laser irradiators which are swingable and installed so that the planes of the respective slit laser beams are not parallel to each other;
A swing angle detecting means for detecting a swing angle of each slit laser irradiator;
I have a,
One intersection is formed by intersecting the planes of the slit laser beams with each other,
A coordinate position detection apparatus that enables laser processing on the workpiece that irradiates the intersection with a laser beam from a machining head by matching the intersection point with a target on the surface of the workpiece . The plane of the slit laser beam is swung at least three slits laser irradiator so as not to be parallel to each other, by irradiating respectively the slit laser light from respective slit laser irradiator, the plane of each slit laser beam Crossing each other to form one intersection ,
A second step of detecting a swinging angle of each slit laser irradiator by rocking angle detecting means,
Only including,
A coordinate position detection method characterized by enabling laser processing on the workpiece that is irradiated with laser light from a machining head by matching the intersection point with a target on the surface of the workpiece .

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