JP2672953B2 - Boundary line automatic sensing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a boundary line automatic sensing method in which a boundary line between two sections on a work is used as a processing line of a processing machine and the boundary line is sensed by a boundary line sensor. It is a thing. “Prior art” Boundary line sensing methods include manually moving a boundary line sensor attached to the tool part of the robot or laser processing machine using a teaching box to sense the boundary line, or weaving the sensor along the boundary line. In addition to the method of sensing while performing the sensing, a method of automatically sensing the boundary line at equal intervals of sensing has already been developed and proposed. [Problems to be Solved by the Invention] However, a large amount of labor is required for the manual sensing work, which is an excessive burden on the worker. Also, in the weaving method, the amount of sensing points becomes enormous and it does not take much sensing time, and the automatic sensing method with equal sensing intervals may not be able to flexibly follow the shape change of the boundary line, that is, the machining line. When performing actual work at the sensing point, there are problems to be solved such as affecting the processing accuracy. "Means for Solving Problems" The present invention is intended to solve the above problems, and its specific means is to use a boundary line between two sections on a work as a processing line, and this processing line Based on the initial values of the sensing center point that is the center of sensing and the sensing start point that starts sensing, and the preset first sensing interval (d _i-1 ) Circularly moves from the sensing start point around the sensing center point, senses a sensing point (P _i-1 ) on the boundary line, and moves from the sensing start point around the sensing center point to the sensing point ( P _i-1) to move the arc angle (θ _i-1) and the sensing distance (d _i-1 based on) the mobile arc angle (θ _i-1) value is smaller as increases as a function F of θ _i-1, d
_i-1 ), a new sensing interval (d _i ) is calculated, and after the next sensing point (P _i ) the line segment (▲
From the sensing start point of the sensing interval (d _i ) on the extension of ▼), sensing is performed by a basic sensing operation of moving the boundary line sensor in an arc with the sensing point (P _i-1 ) as a sensing center, and the obtained sensing point movement arc angle of up to (P _i) (θ _i)
And a new sensing interval (d _{i +} ) by a function F (θ _i , d _i ) that decreases as the moving arc angle (θ _i ) increases based on the sensing interval (d _i ) of the basic sensing operation. ₁ ) Calculate the sensing center as (P _i )
As the moving arc angle (γ _i ) increases based on the moving arc angle (γ _i ) and the sensing interval (d _{i + 1} ) to a new sensing point obtained by moving to a point and performing the basic sensing operation. Function F which becomes small
When the value calculated by (γ _i , d _{i + 1} ) is greater than or equal to the sensing interval (d _{i + 1} ), the sensing point is set as the next sensing point (P _{i + 1} ), When it is smaller, the sensing point (P _i ) is returned to, and the value calculated by the function F (γ _i , d _{i + 1} ) is set as the sensing interval (d _{i + 1} ), and the basic sensing operation is repeated to determine the next position. The feature is that the sensing point (P _{i + 1} ) is obtained. [Operation] As has been clarified by the description of the specific means, the present invention provides a boundary from the sensing start point such that the preset sensing interval is centered on the sensing center point that is the sensing center on the machining line. After moving the line sensor S in an arc to sense the first sensing point, the function F (θ _i ,
The moving arc angle (γ _i ) to the new sensing point obtained by performing the basic sensing operation with the value calculated by d _i ) as the sensing interval (d _{i + 1} ) and the sensing interval (d _{i + 1} ) When the value calculated by the relationship F (γ _i , d _{i + 1} ) of is larger than or equal to the sensing interval (d _{i + 1} ), the sensing point is the next sensing point (P _{i + 1} )
When it is smaller, the sensing point (P _i ) is returned to, and the value calculated by the function F (γ _i , d _{i + 1} ) is set as the sensing interval (d _{i + 1} ), and the basic sensing operation is repeated to The sensing point (P _{i + 1} ) of the position. [Examples] Examples of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a configuration diagram showing the configuration of a laser processing machine according to a specific embodiment of the method of the present invention. The rail 12 is guided by the rails 10 and 11 and driven by a servo motor (not shown) to move in the uniaxial direction. The carrier 13 is slidably arranged on the rail 12, and the carrier screw 2 is rotated by the rotation of the servomotor M2 so that the carrier 2
Move in the axial direction. At the tip of the carrier 13, a wrist 15 that pivots around four axes, five axes, and six axes, respectively, is provided. The list 15 is provided with a processing tool T such as a laser torch that emits a laser beam and a boundary line sensor S. Reference numeral 1 denotes a laser oscillating device, and laser light oscillated by the laser oscillating device is guided to a carrier 13 by mirrors 2, 3, 4 and light guides 5, 6 and emitted from a working tool T to a workpiece W. . FIG. 2 shows the configuration of the boundary line sensor S,
A light irradiation unit 16 and a light receiving unit 17 that receives reflected light that is emitted from the irradiation unit and reflected by the work W are provided. As shown in FIGS. 3A and 3B, the boundary line sensor S uses the processing line on the work W as a boundary line K, and the dark zone L of the colored portion colored with the black spray on one side and the other side. Due to the difference in brightness from the bright zone M, the boundary line K can be detected mainly by the ON / OFF signal due to the amount of reflected light received by the light receiving section 17. Further, as shown in FIGS. 3 (c) and 3 (d), the boundary line sensor S is caused to perform a tilting motion by the combined motion on the 1st to 6th axes, and the detection output by the amount of light reflected from the work W is generated. In addition to obtaining the image straightness by seeking the peak of, the auto focus mechanism (not shown)
Thus, the height Z from the work W can be detected.
Each of the detection operations is performed by the control signal of the sensor controller SC. In addition to the above, the boundary line sensor does not matter as long as it can discriminate between two sections. FIG. 4 shows a configuration of an electric device of the laser processing machine according to the embodiment. In FIG. 3, reference numeral 20 is a central processing unit including a microcomputer and the like. The central processing unit 20 is connected with a memory 25, servo CPUs 22a to 22f for driving servo motors, an operation panel 26 for instructing jog operation, teaching a teaching point, and the like. Servo motors M1 to M6 for driving each axis 1 to 6 of the laser processing machine
Are driven by servo CPUs 22a to 22f, respectively. Each of the servo CPUs 22a to 22f is a central processing unit 2
The target rotation angle obtained by quadratic interpolation based on the rotation angle command data θ1 to θ6 output from 0 and the servo motor M1.
Calculates deviations from outputs α1 to α6 of encoders E1 to E6 connected to M6, and operates to rotate each servomotor M1 to M6 at a speed according to the magnitude of the calculated deviations. . The memory 25 is provided with a storage area PDA for storing the positioning point of the machining tool T, the data representing the orientation of the head and the steady movement speed, and the position data and the orientation data at a plurality of positioning points in the teaching mode. And the moving speed are stored. Further, a storage area PA for storing a program defining the operation of the present apparatus is provided. The boundary line sensor S is a central processing unit via a sensor controller SC.
Connected to 20. Next, the boundary line K which is performed according to the processing of the central processing unit 20
The basic procedure for sensing the will be described with reference to the flowcharts in FIGS. 5 and 6. In step 200, the variable n for designating the sensing point is set to 1. In step 201, the sensing origin P ₀ of the boundary line sensor (hereinafter referred to as sensor) S is taught. Step 202
Then, the sensor S is positioned at the sensing start point A _n ,
Since n = 1 here, it is actually positioned at A ₁ (see FIG. 5). Thus, in order to sense the first sensing point, the sensing origin P ₀ is given as an initial value by teaching, and the sensing start point A ₁ is given a preset position as an initial value. In step 203 P _n
A point sensing operation is performed. The details will be described later. Then, in step 204, the verticality is determined, and details thereof are shown in FIG. In step 205, the height Z _n between the sensor S and the work W is obtained, and the direction is designated to perform positioning. In step 206, each position data X _n , Y _n , Z _n is read, and in step 207, the sensing point P _n = (X _n , Y _n , Z
_n ) is stored in the storage device, but since n = 1, P
₁ = (X ₁ , Y ₁ , Z ₁ ) is stored. In step 208, P _n is
It is determined whether P ₀ is exceeded. That is, it is judged whether or not the sensing is performed over the entire circumference of the processing line. If it does not exceed the value, 1 is added to the variable n for specifying the sensing point in step 209, the process returns to step 202, and the sensor S is positioned at the sensing start point A _{n + 1 in} the specified direction. Specifically, the designated direction is a straight line connecting the sensing points P _n-1 and P _n . The sensing interval is determined by the procedure described later, but the initial sensing interval is the lower limit value dmin. Therefore, the sensing origin P _{0 in} FIG.
And the sensing start point A _{1 has} an interval of dmin. Thereafter, steps 202 to 209 are sequentially repeated until P _n exceeds P ₀ . The above is the basic sensing operation of the sensor S. FIG. 7 is a flowchart showing the operation of determining the perpendicularity. That is, in step 300, the X-axis and Y-axis position data is read, and in step 301, the sensor S is positioned at P (S) = (X _n + x, Y _n + y). In step 302, the in-plane straightness is obtained by the tilting motion of the tilting angle θ described with reference to FIGS. Position P in step 301
In reality, (S) is a position moved by a certain distance (for example, 1 mm) in an arc from the position (X _n , Y _n ) _where the boundary line is sensed to the bright zone side. Next, details of the boundary line sensing operation of the boundary line sensor S will be described with reference to the flowchart of FIG. 8 and FIG. In step 400, the PRE-CHECK processing subroutine is called. This subroutine will be described later in detail. Sensing interval by step 401 step 400 d _{i + 1} and then line ▲ ▼ direction to linearly move the d _{i + 1} by the sensor S and is positioned to a sensing start point A _{i + 1.} In step 401, when sensing the first sensing point P ₀ shown in FIG. 5, the boundary line sensor S is positioned at the sensing start point A ₁ where the sensing interval is dmin. In step 402, the sensing start point A _{i + 1} is
Determine if it is inside or outside the boundary. In this case, the inner side is the dark zone L and the outer side is the bright zone M. If it is inside, the sensing direction is determined in step 403 toward the outside, and if it is outside, in step 404, the sensing direction is determined so as to cross the boundary line K inward. Steps
In 405, the sensing operation is started from the sensing start point A _{i + 1} in the moving direction determined in step 403 or 404 on the arc with the point P _i as the sensing center in the radius d _{i + 1} , and the sensor S is the boundary line. Stop at the point where is detected. Then, in step 406, the POST-CHECK processing subroutine is called. This subroutine will be described later in detail. Steps
At 407, it is determined whether or not a new sensing point P _{i + 1} can be confirmed, and if it cannot be confirmed, the sensor S is returned to the P _i point in order to redo the sensing operation at step 408.
Return to step 401. If you can confirm, P in step 409
Register _{i + 1} points as new sensing points. FIG. 10 is a flowchart showing details of the PRE-CHECK processing subroutine. This subroutine determines the sensing interval for performing the sensing operation. Regarding the determination of the first sensing interval, the lower limit value dmi of the sensing interval set in advance as described above is used.
Since n is used, the processing of the flowchart shown in FIG. 10 is not performed and the sensing interval is determined as dmin, and the process returns to step 402 shown in FIG. In step 500, an extension line and a line segment ▲ ▼ connecting the sensing points P _i-2 and P _i-1 , P _i-1 and P _i
The angle θ _i formed by ▼ is calculated. This angle θ _i is a moving arc angle from the sensing start point A _i to the sensing point P _i where the sensor S senses the boundary line. When sensing the second sensing point P ₂ shown in FIG. 5,
Calculating the angle theta ₁ of a line connecting the segments and sensing the origin P ₀ and the sensing point P ₁ connecting the sensing origin P ₀ and the sensing start point A _1. In step 501, the function F (θ _i , d _i ) of the sensing interval d _i of the immediately preceding sensing operation and the angle θ _i
The sensing interval d _{i + 1} is calculated by Therefore, when sensing the sensing point P ₂ shown in FIG. 5, a function F (θ ₁ , dmin) of the initial sensing interval dmin and the angle θ ₁
The sensing interval d ₂ is calculated by The lower limit value dmin and d _{i + 1} of step 502 preset sensing interval compared to determine the sensing distance as d _{i + 1} = dmin in step 503 if d _{i + 1} <dmin. If d _{i + 1} <dmin is not satisfied, the upper limit value dmax preset in step 504 is compared, and d
_{If i + 1} ≤ dmax, d _{i + 1} is the sensing interval, and d _{i + 1} >
In the case of dmax, in step 505, the sensing interval is determined as d _{i + 1} = dmax. That is, the sensing interval d _{i + 1} is a value between the lower limit value and the upper limit value. Function F (θ _i , d _i ) for calculating the sensing interval d _{i + 1}
The specific contents of are as follows. Where a and b are constants, but the value of a is FIG. 11 is a flowchart showing details of the POST-CHECK processing subroutine. This subroutine shows a procedure of correcting the sensing interval d _{i + 1} for confirming the newly obtained sensing point P _{i + 1} . Figures 11 and 12
This will be described with reference to the drawings. At step 600, the angle γ formed by the line segments ▲ ▼ and ▲ ▼ connecting the sensing points P _{i + 1} and P _i and P _i and P _{i + 1}
Calculate _i . The point P ′ _{i + 1} is a point on the boundary line sensed by the sensing operation with the sensing interval of d _{i + 1} (see FIG. 12). Then, in step 601, the function F is
A new sensing interval d ′ _{i + 1} is calculated from (γ _i , d _{i + 1} ). In step 602, d ′ _{i + 1} and d _{i + 1} are compared,
If d ′ _{i + 1} <d _{i + 1} , then in step 603 d _{i + 1} = d ′ _{i + 1} is set, and in step 604, the P _{i + 1} point confirmation defect flag is set. If d' _{i + 1} <d _{i + 1} is not established, the P _{i + 1} point confirmation good flag is set in step 605 and the process returns to the main routine (Fig. 8) to detect the P'i _{+ 1} point as the next sensing point. Confirm and register as point P _{i + 1} . If P _{i + 1} point confirmation failure flag is set at step 604, at step 407 of the flowchart of FIG. 8, returned to the sensor S in step 408 it is determined that P _{i + 1} point confirmation defective P _i points, corrected Sensing interval d _{i + 1} =
The basic sensing operation is performed at d ′ _{i + 1} , and the boundary line sensing point of the sensor S where d ′ _{i + 1} ≦ d _{i + 1} is determined by the POST-CHECK processing routine is confirmed as the next sensing point P _{i + 1.} And register. "Effects of the Invention" As has been made clear by the description of the concrete means and actions described above, the present invention detects the function of the function F (θ _i ,
After performing the basic sensing operation with the value calculated by d _i ) as the sensing interval (d _{i + 1} ), the function F (γ _i ,
When the value calculated by d _{i + 1} ) is greater than or equal to the sensing interval, the sensing point is set as the next sensing point (P _{i + 1} ), and when it is smaller, the sensing point (P _i ) is returned to. , The value calculated by the function F (γ _i , d _{i + 1} ) is set as the sensing interval, and the basic sensing operation is repeated to obtain the next sensing point.
Even in the case of a complicated boundary line where the part with a large curvature is continuous, it is possible to follow the boundary line of a complicated shape well by the sensing operation that corrects the sensing interval automatically. There is an effect that the working accuracy of work can be maintained with high accuracy. If the calculated sensing interval is less than the preset lower limit value, the sensing interval is set as the lower limit value. Has the effect of being significantly shortened.

BRIEF DESCRIPTION OF THE DRAWINGS The attached drawings show an embodiment of the present invention, and FIG. 1 is an overall configuration diagram of a laser processing machine showing an example of a processing machine for carrying out the present invention.
2 is a block diagram of the boundary line sensor S, FIG. 3 (a),
FIG. 3B is an explanatory diagram showing the boundary line sensing principle, FIG. 3C,
(D) is an explanatory view showing the principle of detecting the surface straightness by the tilting operation, and FIG. 4 is a block diagram of an electric device of the laser processing machine,
5 is an explanatory view showing a basic sensing operation, FIG. 6 is a flowchart showing a processing operation of the central processing unit 20, FIG. 7 is a flowchart showing a surface straightness determination operation, and FIG. 8 is a boundary of the boundary line sensor S. A flow chart showing the details of the line sensing operation, FIG. 9 is the same explanatory view, FIG. 10 is a flow chart showing the PRE-CHECK processing, FIG. 11 is a flow chart showing the POST-CHECK processing, and FIG. 12 is the sensing point P _{i +.} It is explanatory drawing which shows the confirmation procedure of ₁ . 20 ... Central processing unit, K ... boundary line, L ... dark zone, M ... bright zone, S ... boundary line sensor, SO ...
… Sensor controller, P ₀ …… Sensing origin, A _n ……
Sensing start point, P _n ... Sensing point.

Claims (1)

(57) [Claims] The boundary line between the two sections on the workpiece is the machining line, and the initial values of the sensing center point that is the center of sensing on this machining line and the sensing start point that starts sensing, and the preset first sensing interval (d _i- Based on ₁ ), the boundary line sensor for discriminating the two sections is circularly moved from the sensing start point centered on the sensing center point, and the sensing point (P _i-1 ) on the boundary line is sensed. Based on the moving arc angle (θ _i-1 ) from the sensing start point to the sensing point (P _i-1 ) around the sensing center point and the sensing interval (d _i-1 ), the moving arc angle (θ _{i -1} ) becomes smaller as the value becomes larger, a new sensing interval (d _i ) is calculated by the function F (θ _i-1 , d _i-1 ) and the next sensing point (P _i ) is calculated.
After that, the basic sensing operation of moving the boundary line sensor in an arc from the sensing start point of the sensing interval (d _i ) on the extension of the line segment (▲ ▼) with the sensing point (P _i-1 ) as the sensing center. Sensing point (P _i ) obtained by the operation
Function F (θ _i , d _i ) that decreases as the moving arc angle (θ _i ) increases based on the moving arc angle (θ _i ) and the sensing interval (d _i ) of the basic sensing operation. Then, a new sensing interval (d _{i + 1} ) is calculated, and the moving arc angle (γ _i ) to the new sensing point obtained by moving the sensing center to the (P _i ) point and performing the basic sensing operation is calculated. The sensing interval (d
_{i + 1} moving arc angle based on) (gamma _i) is the value calculated by the smaller becomes such a function F as increases _{(γ i, d i + 1} ), the sensing distance (d _{i + 1)} is greater than Alternatively, when they are equal, the sensing point is set as the next sensing point (P _{i + 1} ), and when it is smaller, the sensing point (P _i ) is returned to and calculated by the function F (γ _i , d _{i + 1} ). The above-mentioned basic sensing operation is repeated with the determined value as the sensing interval (d _{i + 1} ), and the next sensing point (P _{i + 1} ) is obtained. 2. When the calculated sensing interval is smaller than a preset lower limit value, the sensing interval is set as the lower limit value. The automatic boundary line sensing method according to claim 1. 3. The automatic boundary line sensing method according to claim _1, wherein the first sensing interval (d _i-1 ) is a lower limit value.