JPS63250506A - Position control means for sensor for machining - Google Patents

Abstract

PURPOSE:To measure a proper point on a work automatically by grasping the surface shape of the work according to an attitude such as working line coordinates and changing the position of a sensor for machining automatically according to the moving direction of a working head. CONSTITUTION:The surface shape of the work W is decided according to the coordinates of working lines K(K1-K3) and the attitude of the working head, and the sensor 20 for machining is moved according to the moving directions A, B, and C of the head 1 and the surface shape of the work W to measure a 1st point on the work W in the front in the moving direction or measure a 2nd point on the work W sideways in the moving direction. Consequently, when it is decided that the working lines K1 and K2 are displaced at right angles to the moving directions A and B of the head 1, the position of the sensor 20 is so controlled to in front of the head 1 in the moving directions A and B and when it is decided that the working line K3 is displayed at right angles to the moving direction C of the head 1, the position of the sensor 20 is controlled to by the head 1 in the moving direction C.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for controlling the position of a processing sensor used in a processing device u that performs cutting or welding along a processing line of a workpiece, and particularly to The present invention relates to a method for controlling the position of a processing sensor that can automatically switch the position of the sensor depending on the traveling direction and the surface shape of a workpiece.

[Prior Art] Devices for cutting or welding workpieces using laser light or the like have been well known, and generally there are devices in which the machining line on the workpiece is taught in advance and the workpiece is machined in accordance with the teaching. The Chingupreibatsu evening ceremony is used.

In addition, in this type of equipment, it is necessary to maintain an appropriate distance between the processing head and the workpiece during processing, so an optical processing device is installed near the processing head to measure the height from the processing head to the workpiece. A sensor is provided.

In this case, the output of the laser beam for processing is strong, and the surface of the workpiece after processing is unstable, so in order to measure the height with high precision, it is necessary to point the workpiece at a point slightly distant from the point being processed. For example, if the light spot of the machining sensor is located at the rear in the direction of movement, the height to the workpiece may not be measured correctly during actual machining due to the influence of the machining laser light. Therefore, machining sensors usually measure points on the workpiece in front of the machining head in the direction of movement.

However, depending on the surface shape of the workpiece, it may be difficult to place the machining sensor in front of the machining head in the forward direction. It is necessary to measure a point on the workpiece that is slightly distant from the direction of travel and is less affected by the laser beam.

In order to control the position of the machining sensor as described above, conventionally, while driving the machining head along the machining line under manual control by an operator, the position of the machining sensor relative to the machining head is also taught.

The taught machining sensor position control information is stored in a data memory, and the position of the machining sensor is appropriately controlled during workpiece machining.

[Problems to be Solved by the Invention] As described above, the conventional method of controlling the position of a machining sensor requires manual work by an operator along the machining line, which requires a lot of time and effort. was there.

This invention was made to solve the above problems, and it grasps the surface shape of the workpiece based on the machining line coordinates and the attitude of the machining head, and automatically performs machining according to the direction of movement of the machining head. The present invention aims to provide a position control method for processing sensors that can automatically measure appropriate points on a workpiece by changing the position of the processing sensors.

[Means for Solving the Problems] In the processing sensor position control method according to the present invention, the processing sensor is positioned on the workpiece in front of the processing head in accordance with the traveling direction of the processing head and the surface shape of the workpiece. It is designed to measure the first point of the workpiece or the second point of the workpiece in the horizontal direction.

[Operation] In this invention, when it is determined that the processing line is not displaced perpendicularly to the direction of movement of the processing head, the position of the processing sensor is controlled so that it is in front of the processing head with respect to the direction of movement, If it is determined that the machining sensor is displaced vertically, the position of the machining sensor is controlled so that it is in the lateral direction of the machining head with respect to the traveling direction.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. 1st
The figure is a schematic perspective view showing the axis ellipse of a conventional processing apparatus (10) to which the present invention is applied, and FIG. 2 is a schematic sectional view showing an enlarged processing head portion in FIG. 1.

In the figure, (10m) is an arm that becomes the drive part of the processing device (10), and the β axis (11) located at the drive end,
The α axis (12) connected to the β axis (11) and the α axis (12
) connected to the Z axis (13).

(1) is a processing head to which a β-axis (11) is attached, which moves along a processing line K on a workpiece W and emits processing laser light from its tip. (2)
is a β bearing for rotating the β axis (11) in the direction of arrow β via the motor (M5), and (3) is a bearing for rotating the α axis (12) in the direction of arrow α via the motor (M4). It is an α bearing.

(4) is a Z bearing for moving the processing head (1) in the two directions of arrows via the motor (M3), and (5) is the motor (
M2) is the Y bearing for moving the processing head (1) in the direction of arrow Y, and (6) is the X bearing for moving the processing head (1) in the direction of arrow X via the motor (old). be.

(20) is a processing sensor rotatably mounted on the β axis, and is composed of a well-known optical sensor equipped with a light emitting part having a semiconductor laser and a light receiving part having a semiconductor position detector (PSD). ing. Then, the measurement laser beam L1 emitted from the light projecting unit is irradiated near the processing position on the processing line,
The reflected measurement laser beam L2 is received by the light receiving section.

(2X) is connected to the processing sensor (20
) is a γ bearing for rotating in the direction of arrow γ.

In addition, each motor (Ml) to (H5) in the processing device (10)
is driven by the machine program command from the NC control unit (not shown), and the spot of the machining laser light emitted from the machining head (1) follows the machining line K, and the attitude of the machining head (1) is adjusted. It is controlled to be substantially perpendicular to the surface of the workpiece W. The cannibal program is obtained by a data processing unit (not shown) based on the teaching coordinates of the machining line, and is stored in advance in the memory in the NCυ control unit.

Next, the flowchart diagram in Figure 3 and Figures 4 and 5 will be explained.
An embodiment of the present invention will be described with reference to explanatory diagrams of the figures.

First, the number of the external storage device, the original program name, the program name after setting, the range of coordinate points on the machining line to be calculated, and the second coordinate point on the workpiece W away from the machining line K in the 4HH direction Input whether the point is on the right or left and perform initial settings (step-5t).

Next, it is determined whether or not the input calculation target is all the coordinate points (step S2). If all the coordinate points are the target, new data for driving the motor (H6) of the processing sensor (20) is inputted. Create (step S3).

Also, it is determined whether or not a range of coordinate points is specified (step S4), and if the range is specified, the numbers of the starting Fi gauge point and the final coordinate point are input (step S5), and within this range, the motor (H6 ) Create new data for IS [K operation (
Step S6), and then it is determined whether or not to continue the H1 calculation (step S7), and if it is continued, the snip S5
Return to

On the other hand, if the data creation (step S3) is completed or it is determined that calculation is not to be continued (step S7), the calculation program is ended and the process returns to the main program. or,
If the range of coordinate points to be calculated is not specified (step S4), it is determined whether the process is finished or not (step S8).
, if it is not finished, the process returns to step S2, and if it is finished, the process returns to the main program.

The calculation of new data for driving and operating the motor M6 in steps S3 and S6 is performed as follows.

First, as shown in Fig. 4, each coordinate point on the machining line is
i, Pi++, .
11) The direction unit vector indicating the direction is η(α,β)
Then, the component of the directional unit vector ξ(α) of the α axis (12) is ξ(a)==(cosa, -5ina, 0)β
The components of the directional unit vector η (α, β) of the axis (11) are:
η(α,β)−(sinαsinβ,cosαsinβ
, -eO9β). Here, unit vectors ξ(α) and η(α
, β) correspond to the attitude of the processing head (1).

Coordinate points P i, P i++ with coordinate numbers i and i+1
Each coordinate component of is (xi, yi, zi), (X; +I
, yi++, zi++), the processing head (1
) is expressed as follows: ei= P iP i+1/ l P iP i+
, l=[1/((×i+l)2 in ()'!+1>2+(
ZI+1)2M"]×(×effect bixi, yi+1yi, z
It is expressed as i+bizi)=(el, e2・eko).

Now, as shown in Fig. 5, a machining line K is placed on the curved workpiece W.
1. Let us consider the case where cutting is performed while proceeding in the directions of arrows A, B, and C.

Processed wire K1. 2 along arrows A and B, the machining sensor (20) is aligned with the machining head (
1) must be placed in front of. At this time (L7), since 1 and H2 are not displaced in the direction perpendicular to the direction of movement on the machining line on the workpiece W, even if β1111 (II) rotates, the direction of the α axis (12) is in the direction of movement. remains parallel and constant.

When cutting 3 along the machining line along arrow C, the machining sensor (20) must be arranged in the lateral direction of the machining head (1) with respect to the advancing direction. Since line 3 is displaced in a direction perpendicular to the direction of travel, the direction of the α-axis (12) is approximately perpendicular to the direction of travel, thereby controlling the rotation of the β-axis (11).

Here, if we consider the angle ψi between the directional unit vector ξ(α) of the α-axis (12) and the directional unit vector ei of the traveling direction, the angle ψi is ψ1=cos-'(ξ(a Le i ).

When processing the processing line Kl or 2, the angle ψ
The absolute value of i is 1ψil''=, 0° ... ■ When processing 3 on the processing line, 1ψilζ90
° ... ■ Actually, depending on the shape of the workpiece W, it may not be possible to take the posture shown by the formulas ■ and (■), but here, the description will be made assuming that the formulas (2) and (2) are satisfied.

Therefore, the absolute value of the angle ψi is set to the predetermined value ψ. (For example, 15
degree) compared to the predetermined value ψ. Below, 0≦1ψ11≦
ψ. ... If (2), it is determined that the formula (2) is satisfied, and the machining sensor (20) is driven and controlled so as to be located in front of the machining head (1) in the traveling direction. Therefore, the processing sensor (20) detects a point (first
Measure the height of the point).

Also, the predetermined value ψ. Greater than ψ. ku1ψ11≦90” ... If ■, ■
It is determined that the processing sensor (20) satisfies the formula, and the processing sensor (20) is
The drive is controlled to be in the lateral (perpendicular) direction of the processing head (1) with respect to the direction of movement. Therefore, the machining sensor (2
0) is a point (second
Measure the height of the point).

At this time, the machining sensor (
20) The rotation angle θ is calculated within the range of −150”≦(1≦150V), but the range of this rotation angle θ is predetermined by the limitations of the rotation mechanism of the processing sensor (20). .

When determining the rotation angle θ of the machining sensor (2o) when formula 0 (formula ■) is satisfied, first find the rotation angle θ with respect to the direction of travel. (-90° × θ.<90°), θo= ja
n-'[((e+sinα+e2cosα)cosβ÷
e3sinβ)/(e2sinα−e+eO3α)]
Find from. At this time, the rotation angle θ. The sine and cosine of are 5ineo=-[(e1sinα+e2cosa)c
osβ+e, sinβ]/kcosθo= (e+co
sα−ezsinα)/, where k= [(e2cos
βtoe cosa sinβ)2+ (e3sinα
sinβ +e, cosβ) 2 <e+cosa
sinβ−e2sinαsinβ)2]1/2. Therefore, the actual rotation angle θ with respect to the β axis is: (i) cos θo = O, and if sin θ, > 0, then θ, = 90', sin θ. <
C11) If cos θ > 0, then θ1=θ. (iii) If cos θ is 0 and sin θ.>, then θ ,=θ.+1800, however,
If θ, > tSOo, θ, = 150", sin θ. If 0, θ1-θ. -1800,53L, θ, <-
If it is 150°, then 6) + = 150''.

On the other hand, the rotation angle θ2 when the equation 0 (formula 2) is satisfied is obtained by adding ±90° to the rotation angle θ obtained as described above. In other words, if the right side is specified in the initial settings, add 90°, and if the left side is specified, add -90''.f!l
! If L, 1θ2+>150°, then 1θ21=150°.

In this way, the NC control unit (not shown) determines the coordinates of each coordinate point pi, Pi++, ... on the processing line and the processing head (1).
1-1 The position of the processing sensor (20) is controlled so as to always measure an appropriate point on the workpiece W.

[Effects of the Invention] As described above, according to the present invention, the surface shape of the workpiece is determined based on the coordinates of the processing line and the attitude of the processing head, and the progress is determined according to the traveling direction of the processing head and the surface shape of the workpiece. Measure a point on the workpiece in front of the direction, or
Since the point 6 on the workpiece in the lateral direction is measured, there is an effect that a method for controlling the position of the machining sensor that can automatically measure an appropriate point on the workpiece can be obtained.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view showing the shaft configuration of a general processing device to which the present invention is applied, FIG. 2 is a schematic cross-sectional view showing an enlarged view of the processing head in FIG. 1, and FIG. Flowchart 1 for explaining an embodiment of the invention, FIG. 4 is an explanatory diagram showing the direction unit vector used in an embodiment of the invention, and FIG. It is an explanatory diagram showing an example. (1)...Processing head (10a)...Arm (11)...β axis (12)...α axis (2
0)... Processing sensor W... Workpiece K... Processing line Pi... Coordinate point ξ (α), ei...
- Directional unit vector ψi...An angular direction formed by each directional unit vector. In the figure, the same reference numerals indicate the same or equivalent parts. 1 Figure 1 10a: 7-4 11 + β axis] 2, axis 20 η0 machining "Se, -" W, determine the force loe on the workpiece.

Claims (2)

[Claims] (1) In a position control method for an optical processing sensor that is movably provided near a processing head that advances along a processing line of a workpiece and measures a height from the processing head to the workpiece, the processing The surface shape of the workpiece is determined based on the coordinates of the line and the attitude of the processing head, and the processing sensor is moved according to the traveling direction of the processing head and the surface shape of the workpiece. Position control of a processing sensor, characterized in that a first point on the workpiece in front is measured or a second point on the workpiece in a direction transverse to the traveling direction is measured. Method. (2) A machining sensor is rotatably provided on the β axis for adjusting the angle of the machining head with respect to the workpiece surface, and the direction of the α axis for rotating the machining head in a plane parallel to the workpiece surface is adjusted. If the angle between the direction unit vector indicating the direction of movement of the processing head and the direction unit vector indicating the traveling direction of the processing head is less than a predetermined value, the first point on the workpiece is measured; if it is larger than the predetermined value, the first point on the workpiece is 2. The method for controlling the position of a machining sensor according to claim 1, wherein the machining sensor is appropriately rotated so as to measure the second point.