JPH01191002A - Multi-sensor for automatic working machine - Google Patents

Abstract

PURPOSE:To improve a border recognizing function and a surface perpendicularity detecting function by providing a 1st laser light source and a 2nd laser light source and switching and controlling them, and detecting the peak values of the quantities of laser light beams incident on a photodetection part. CONSTITUTION:A laser diode 17 is turned on to perform sensing movement on an X-Y plane along a constant sensing path, and the photodetection part 19 detects the difference in the quantity of reflected light on the border line of a bright zone and a dark zone. Swinging and tilting operation in a direction perpendicular to the plane where laser diodes 17 and 18 and photodetection part 19 are matched and arranged is performed by the arcuate operation of a sensor head 16 about a measurement point as the center and the peak value of the quantity of the laser light detected by the photodetection part 19 is detected to find the surface perpendicularity in the direction of the swinging and tilting operation. The laser diode 17 is turned off and the laser diode 19 is turned off to find the surface perpendicularity similarly.

Description

[Detailed description of the invention] "Industrial application field" The present invention relates to a multi-sensor for automatic processing machines.

"Conventional technology" In order for an automatic processing machine such as a laser processing machine to trace the processing line and perform a specified processing operation, the processing line must be taught in advance.We aim to improve the efficiency of this teaching work. Therefore, various automatic teaching methods have been developed.

During automatic teaching, in addition to detecting the processing line, it is necessary to detect the distance to the workpiece and the surface squareness of the workpiece. Sensors for this purpose include touch type, He
There is a method using a triangulation method using a Ne laser diode. Of these, the one using a laser diode is most suitable from the standpoint of practicality, but one that fully satisfies all of the distance characteristics, boundary recognition function, and surface squareness detection ability required for a sensor used for teaching is available. The reality is that this is not the case.

``Problem to be solved by the invention'' When detecting the surface straightness of a workpiece by receiving the reflected light of the laser beam irradiated onto the workpiece from a laser diode and detecting the peak value of the light intensity by the tilting operation of the senna. , as shown in Fig. 7(a), when the direction of irradiation of the laser beam is vertically downward and the viewing angle on the receiving side is set to α°, the tilting operation is performed at a tilt angle of ±β°. The peak value of the amount of light reflected by the specularly reflected light is detected at a position shifted by °/2 (see figure (b)), but as shown in figure (c), the tilt plane is perpendicular to the tilt plane of the tilt movement described above. When performing the same tilting operation, the glare angle α0 on the light receiving side is
It is possible to correctly detect the surface squareness at the peak value of the amount of reflected light due to specular reflection without being affected by (see figure (d)
)) Also, since the sensor must detect not only the surface squareness but also the distance (height) to the workpiece and the machining line, it is better to fix the laser beam in a vertically downward direction. is advantageous in terms of teaching workability.

Furthermore, it can be seen that in order to avoid the influence of specularly reflected light, it is necessary to arrange another light source symmetrically with the light receiving side so as to utilize specularly reflected light (Figures 8 (a) and (b)). .

The present invention has been made in view of the above points, and has the distance characteristics necessary for a sensor used in teaching work,
The problem to be solved is to provide a multi-sensor for automatic processing machines with improved boundary recognition function and especially surface squareness detection function.

"Means to solve problems" A specific means for solving the above problem is as follows.

A first laser light source that irradiates laser light in the Z-axis direction to a sensor head that can move in the Y and Z axes, rotate around the three axes, and move by combining the above movements; a second laser light source that irradiates a laser beam at a point on the optical axis at an incident angle θ; and a second laser light source that irradiates the laser beam at a point on the optical axis of the first laser beam at a reflection angle θ. a light receiving section that receives light, which are aligned and arranged in parallel in the same plane, and detecting means for detecting a peak value of the amount of light incident on the light receiving section; The present invention is characterized in that a switching control means for alternately switching the second laser light source is provided.

"Operation" The present invention has the configuration clarified in the explanation of the specific means described above, and first, the first laser light source is turned on for a workpiece whose processing line is a boundary line divided into a bright zone and a dark zone. Then, the second laser light source is turned off, and the sensing movement is performed on the X-Y plane along a fixed sensing path, and the difference in the amount of reflected laser light at the boundary between the bright zone and the dark zone is detected and processed. After determining the line, the first. A tilting operation in a direction perpendicular to the plane in which the second laser light source and the light receiving element are aligned and arranged is performed by moving the sensor head in an arc centered on the measurement point, and the amount of reflected light of the first laser beam received by the light receiving element is reduced. Detect the peak value and find the surface squareness in the direction of the tilting operation.
Further, the first laser light source is turned off, the second laser light source is turned on, and the tilting operation in the direction perpendicular to the tilting plane of the tilting operation is performed by moving the sensor head in an arc centered on the measurement point as described above, and the light is received. The peak value of the amount of reflected light of the second laser beam received by the element is detected to determine the surface squareness in the direction of the tilting operation, and then using the first laser light source, the Z
Find the distance to the workpiece by moving in the axial direction.

"Example" Embodiments of the present invention will be described below based on the accompanying drawings.

Fig. 1 shows the configuration of a multi-sensor S for an automatic processing machine, in which a sensor head 16 installed on a wrist 15 (described later) to enable composite movement on 1 to 6 axes is attached to a sensor head 16 that is arranged vertically downward in the Z-axis direction a laser diode 17 that is a first laser light source that irradiates laser light to a point on the second laser optical axis; a laser diode 18 that is a second laser light source that irradiates a laser light at an incident angle θ to a point on the second laser optical axis; A light receiving section 19 is placed on the optical axis of the reflected light reflected at a reflection angle θ from a single point on the second laser light source.
Align and arrange in parallel within the same plane. The light receiving section 19 changes the output voltage depending on the amount of light received.

When using this multi-sensor S as a boundary line sensor for detecting the processing line of the workpiece W, the laser diode 17 that is the first laser light source is turned on, the laser diode 18 that is the second laser light source is turned off, and the 211(a)
), as shown in (b), with the machining line on the workpiece W as the boundary line, the light-receiving area is By changing the amount of reflected light received at step 19, the ON10FF signal can be output and the boundary line K can be detected. Further, as shown in FIGS. 2(c) and 2(d), the multi-sensor S is caused to tilt at a tilt angle β by the composite motion on the 1st to 6th axes, and a detection output is generated based on the amount of light reflected from the workpiece W. The peak of the angle is determined to determine the surface squareness in the direction of the tilting motion, and the laser diode 17 is turned off and the laser diode 18 is turned on to generate a tilting motion in a direction perpendicular to the tilting plane of the tilting motion. The surface squareness in this direction can be determined in the same manner as described above, and the height Z from the workpiece W can be detected by an autofocus mechanism (not shown) using the laser diode 17. Each of the detection operations described above is performed by a control signal from a sensor controller SC, which will be described later, but switching control of the laser diodes 17 and 18 can also be performed by a switch provided on an operation panel 26, which will be described later.

FIG. 3 is a configuration diagram showing the configuration of a laser processing machine equipped with the multi-sensor S for automatic processing machines of the present invention.

The rail 12 is guided by rails 10.11 and is driven by a servo motor shown in the figure to move in one axis (X) direction. The carrier 13 is slidably disposed on the rail 12, and is moved in two axes (Y) directions by a feed screw 14 rotated by rotation of a servo motor M2. At the tip of the carrier 13, wrists 15 that rotate about four axes, five axes, and six axes, respectively, are arranged. The list 15
There is a processing tool T such as a laser torch that irradiates laser light.
and a multi-sensor S are provided. 1 is a laser oscillation device, and the laser beam oscillated thereby is guided to a carrier 13 through light guide paths 5 and 6, and is emitted from a processing tool T to a workpiece W. The light guide path 5 is extendable and retractable, and the rail 11.1 is attached to the side of the laser oscillation device.
A slider 4 that slides within a guide 3 formed parallel to the light guide path 6 is connected to the light guide path 6 .

FIG. 4 shows the configuration of the electrical device of the laser processing machine. In FIG. 4, 20 is a central processing unit consisting of a microcomputer or the like. The central processing unit 20 is connected to a memory 25, servo CPUs 22a to 22f for driving the servo motors, and an operation panel 26 for issuing commands for jog operation, teaching of teaching points, and the like. Servo motors M1 to M6 for driving axes 1 to 6 of the laser processing machine are each driven by a servo CPU 22. a~22f
driven by.

Each of the servo CPUs 22a to 224 receives rotation angle command data θ1 to θ output from the central processing unit 20.
6 and the encoders E1 to E6 connected to the servo motors M1 to M6.
The deviation between the outputs α1 to α6 of the servo motors M1 to M is calculated, and each servo motor M1 to M
It operates to rotate 6.

The memory 25 is provided with a storage area PDA that stores data representing the positioning points of the machining tool T, the orientation of the head, and steady movement speed, and in the teaching mode, position data and orientation data at a plurality of positioning points are stored. and movement speed are memorized.

Further, a storage area PA is provided for storing a program that defines the operation of the device. Multi-sensor S is connected to central processing unit 20 via sensor controller SC.

Next, the sensing operation of the multi-sensor S of the present invention will be explained.

FIG. 5 is a flowchart showing the processing of the central processing unit 20 when sensing a closed circular processing line.

In step 200, a variable n for teaching point designation is set to 1.

In step 201, the sensing origin P0 of the boundary line sensor (hereinafter referred to as sensor) S, the sensing direction, and the conditions regulating the sensing operation are input. Step 202
After the sensor S is positioned according to the conditions in step 201, the machining line is determined, and subsequently, in step 203, the surface squareness is determined. The details are shown in FIG. 6 and will be explained later. In step 204, the height Zh between the sensor S and the workpiece W is determined, and the direction is specified to perform positioning. In step 205, each position data x, ..., y11... z, , is included in m and stored and taught in the storage device as p,=(x,l,y,,zll) in step 206, but when n=1, from Luke to P+=
(X+, Y+, Z l) is taught. Step 2
At step 07, it is determined whether Pl exceeds Po.

That is, it is determined whether sensing has been performed all around the processing line. If not, 1 is added to the variable n for teaching point designation in step 208, and the process returns to step 202.

Thereafter, steps 202 to 2 are performed sequentially until P1 exceeds Po.
Automatic sensing is performed by repeating the basic mode up to 08, and teaching points PI to Po are sequentially taught.

A detailed explanation of the processing line determination operation in step 202 will be omitted since it is outside the scope of the present invention.

FIG. 6 is a flowchart showing the surface straightness determination operation.

In step 400, X-axis and Y-axis position data are read, and in step 401, P(S)=(X, +x).

y, +y). The position HP (S) in step 401 is a position retreated a certain distance toward the bright zone M on the movement route in the opposite direction to the movement direction from the position where the multi-sensor S sensed the boundary line and stopped moving. shall be. In step 402, as shown in FIG. 2(c),
The surface squareness is determined by the first tilting operation at the tilting angle β explained in (d).

Subsequently, in step 403, the light receiving section 19 detects the peak value of the amount of reflected light and detects and stores the tilt angle β' when the output is maximized. Further, in step 402, the first laser light source is switched to the second laser light source, and the laser diode 17 is switched to the second laser light source.
and turn on the laser diode 18, step 4
05, the second tilting operation is performed, and in step 406, the tilting angle β'' at the maximum output of the light receiving section 19 is detected and stored in the same manner as described above.The second tilting operation is performed as described above.
This is a tilting motion in a direction perpendicular to the tilting plane of the first tilting motion.

1st. Tilt angle β in two directions determined by the second tilt operation
′, β”, it is possible to accurately determine the surface squareness of the measurement point.6 In addition, the multi-sensor S of the present invention is capable of not only recognizing processing lines, but also recognizing boundaries based on the brightness of objects, measuring distances, and surface squareness. It can also be used to recognize and teach the shape of three-dimensional objects.

"Effects of the Invention" As clarified by the explanation of the above-mentioned specific means and operation, the multi-sensor for automatic processing machines of the present invention provides a first laser light source and a second laser light source, performs switching control, and controls the switching of the first laser light source. The combination of the laser light source and the light receiving section has the function of a boundary line sensor, and the combination of the second laser light source and the light receiving section allows the detection of the surface straightness in the direction perpendicular to the surface straightness detection direction to be performed by a predetermined tilting operation. This eliminates the inconvenience that the peak value of the amount of reflected light received by the light receiving section is affected by specularly reflected light and makes it impossible to detect the true surface straightness, thereby further improving the surface straightness detection characteristics. have Moreover, there is an effect that the multi-sensor can be miniaturized since there is only one light receiving section.

[Brief explanation of the drawing]

The accompanying drawings show embodiments of the present invention, and FIG. 1 is a configuration diagram of a multi-sensor S for automatic processing machines of the present invention, and FIGS.
b) is an explanatory diagram showing the boundary line detection principle, Fig. 2(C), (
d> is an explanatory diagram showing the principle of detecting surface squareness by tilting motion, Figure 3 is an overall configuration diagram of a laser processing machine equipped with multi-sensor S, and Figure 4 is a diagram of the electrical equipment configuration of the laser processing machine. , FIG. 5 is a flowchart showing the processing operation of the central processing unit 20, FIG. 6 is a flowchart showing the straightness determination operation, and FIGS. 7(a), (b), (c), and (d) are the tilting operations. An explanatory diagram comparing the direction of the direction and the output of the amount of reflected light, Fig. 8 (
Figures a) and (b) are explanatory diagrams of the case where the light receiving section and the laser light source are arranged symmetrically and the tilting operation is performed, and the output of the amount of reflected light. 17.18. ,,laser diode, 19,,,
Receiving Department, 20. , , central processing unit, S03. Multi-sensor, S C, Senna controller, P0
91, Sensing origin, P, , teaching point. Figure 1 (a) (C) / Figure (b) (d) Tilt angle change Figure 6 Figure 7 (a) (C) ノ (b) Ah/S angle (d) A L/S angle

Claims (1)

[Claims] a first laser light source that irradiates laser light in the Z-axis direction to a sensor head that can move in the X, Y, and Z-axis directions, rotate around the three axes, and move by combining the above movements; a second laser light source that irradiates a laser beam at a point on the optical axis of the light at an incident angle θ; and a second laser light source that irradiates a laser beam at an incident angle θ to a point on the optical axis of the first laser beam, and a reflected light beam that is reflected from a point on the optical axis of the first laser beam at a reflection angle θ. A light receiving section that receives the reflected light is aligned and arranged in parallel within the same plane, and a detection means that detects a peak value of the amount of light incident on the light receiving section and the first and second laser light sources are alternately arranged. A multi-sensor for an automatic processing machine, characterized in that it is provided with a switching control means for switching to.