JP2542615B2 - Machining line teaching method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a machining line teaching method for detecting a measurement point while scanning a singular line by a weaving operation,
Particularly, the present invention relates to a machining line teaching method in which the posture of the sensor head can follow the copying surface.

[Prior Art] Conventionally, a device for cutting or welding a work by using a laser beam or the like is well known, and generally, teaching for processing a work line on a work in advance and processing the work line as it is. The playback method is used.

In order to perform this teaching, conventionally, the position and the posture of the machining head are input point by point while the machining head is driven along the machining line under the manual control of the operator. Depending on the situation, it usually takes several hours.

[Problems to be Solved by the Invention] As described above, since the conventional machining line teaching method is performed manually by the operator, there is a problem that it takes a lot of time and labor.

The present invention has been made to solve the above problems, and an object thereof is to provide a machining line teaching method capable of automatically and reliably teaching machining lines.

[Means for Solving Problems] In the machining line teaching method according to the present invention, a weaving operation of a sensor head is performed to trace a singular line, and a normal line at a measurement point detected on the singular line is calculated.
Steps, a second step of calculating the deviation angle between the normal line and the optical axis of the sensor head, a third step of comparing the deviation angle with the latitude angle of the sensor head, and the deviation angle within the tolerance angle. In the case of, the posture of the sensor head is not changed, and when the deviation angle is larger than the latitude angle, the posture of the sensor head is changed to the fourth step of changing the posture of the sensor head so that the optical axis follows the normal line. Based on this, a fifth step of calculating the position and orientation of the sensor head with respect to the next weaving point, and a sixth step of generating a singular line position and orientation signal including position and orientation data of the measurement point are provided.

[Operation] In the present invention, when the singular line is scanned and measured by the weaving operation, the posture of the sensor head with respect to the next weaving point is determined according to the normal line at the detected measurement point, and the singular line position including this posture data is determined. Generate an attitude signal.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a processing apparatus to which an embodiment of the present invention is applied.

In the figure, (10) is a processing machine body that can move three-dimensionally, and is provided with a plurality of motors (for example, five corresponding to the five axes X to Z, α and β) (not shown), and Arm tip (10a) of processing machine body (10) based on rotational position
The position detection signal L indicating the position and the posture of is output.

T is a singular line provided along the working line of the work, and is made of, for example, a 0.4 mm wide non-reflective black tape attached on the working line.

(20) is a sensor head attached to the arm tip portion (10a), a semiconductor laser that emits infrared laser light (see broken line), a light receiving element that receives the laser light diffusely reflected on the surface of the work, A signal processing unit (all not shown) that outputs a height detection signal H and a singular line detection signal D based on the signal obtained by this light receiving element is incorporated.

The signal processing unit in the sensor head (20) inputs a control signal for keeping the amount of received light constant to a semiconductor laser drive circuit (not shown), and a sharp rise of this control signal A non-reflective singular line T, for example, a singular line detection signal D indicating the presence of a black tape is output.

Reference numeral (30) is an NC control unit for driving the processing machine body (10), and based on the position detection signal L, the arm tip (10
A drive signal M for positioning a) is output.

Reference numeral (40) is a scanning measurement calculation unit, which is based on the position detection signal L, the height detection signal H, and the singular line detection signal D In addition to outputting C, the weaving coordinate signal W used for the weaving operation that follows the singular line T is output to the NC control unit (30).

A data processing unit (50) generates a machining program R based on the singular line position and orientation signal C and outputs the machining program R to the NC control unit (30).

(60) is an operation panel connected to the NC control section (30),
An initial setting command, an operation command and the like for driving the processing machine body (10) are input to the NC control unit (30).

Reference numeral (70) is a teaching box connected to the NC control unit (30), and driving commands for the processing machine body (10) can be manually input to the NC control unit (30).

Next, an embodiment of the present invention will be described with reference to FIG. 1, an explanatory view of FIG. 2 showing a weaving operation, an explanatory view of FIG. 3 showing a measuring point detection operation, and a flow chart of FIG. To do.

First, a singular line T is formed on the machining line of the work, the sensor head (20) is provided at the arm tip (10a), and the operation panel (6
Set the NC control unit (30) to the teaching mode via 0).

Next, the singular line T is passed through the teaching box (70).
Enter the start point P _S , direction indicator P _D and end point P _E of
Initialize the weaving width WD (usually about 10 mm) and the pitch 1 (usually several mm) for the weaving operation. Then, activate the NC control unit (30) via the operation panel (60),
A copying measurement (weaving operation) for automatic teaching as shown in FIG. 2 is executed.

That is, the irradiation point of the laser light from the sensor head (20) is moved from the starting point P _{S in the} direction perpendicular to the direction indicating point P _D ,
An intersection with the singular line T, that is, a point moved by a predetermined amount after detecting the measurement point P ₁ is defined as a first weaving point Q ₁ . Then, it is folded back along a straight line connecting the starting point P _S and the first weaving point Q ₁ (in the drawing, the measurement points are shown separated from each other for convenience).
P ₁ ′ matches measurement point P ₁ ), a predetermined amount (weaving width)
The moved point (corresponding to WD) is the second weaving point Q ₂ . Subsequently, the light spot of the laser light is moved toward the third weaving point Q ₃ while inclining the light spot toward the direction indicating point P _D by a predetermined pitch l, and thereafter, the weaving points Q ₄ are sequentially folded back. In this way, the measurement points P _{1 to} Pn are detected while tracking the singular line T until reaching the vicinity of the end point P _E.

Since the singular line T does not reflect light, the measurement points P _{1 to} Pn
Although it is not possible to directly detect the coordinates of, the midpoint coordinates of both ends T _S and T _E of the singular line T measured between the pair of weaving points Qi to Qi ₊₁ are shown in FIG. Measured as Pi. At this time, since the reflected laser light is disturbed at the edge of the singular line T, a point on the work slightly separated from the edge of the singular line T is used as each coordinate of both ends T _S and T _E. .

At the same time, the copying measurement calculation section (40) constantly calculates the weaving posture of the sensor head (20) based on the program shown in FIG.

Here, assuming a case where the laser beam irradiation point from the sensor head (20) moves from the weaving point Qi to Qi _+1, orientation of the sensor head (20) between the weaving point Qi～Qi ₊₁ is , And is determined in advance based on the normal line at the previous measurement point Pi ₋₁ .

First, between the weaving points Qi and Qi _{+ 1} , the current measurement point Pi
When is measured, the normal line at this measurement point Pi is calculated (first step S1).

At this time, the local coordinate system (90) of the machined surface including the measurement point Pi is actually obtained. That is, the vector between the previous measurement point Pi _-1 and the current measurement point Pi is the X-axis direction, and the cross product of this X-axis direction vector and the vector between the ends T _S and T _E is the Z-axis direction. Further, the outer product of the vectors in the X-axis direction and the Z-axis direction is the Y-axis direction. In the local coordinate system (90) calculated in this way, the XY plane represents the processed surface at the measurement point Pi, and Z represents the normal line.

Next, a deviation angle θ between the optical axis A of the sensor head (20) at the weaving points Qi to Qi _{+ 1} and the normal line Z at the measurement point Pi is calculated (second step S2), and this deviation angle θ is calculated. A comparison is made with a predetermined latitude angle θ ₀ (an allowable angle of the sensor head with respect to the work, about 15 °) (third step S3).

Here, if the deviation angle θ is within the tolerance θ ₀ , the attitude of the sensor head (20) is not changed and the current attitude is used for the next weaving attitude (fourth step S4). If it is larger than the angle θ _0, the attitude of the sensor head (20) is changed so that the optical axis A follows the normal line Z (fourth step S4 ′).

Based on the attitude of the sensor head (20) thus determined, the scanning measurement calculation section (40) determines the next weaving point Qi.
The position and orientation of the sensor head (20) with respect to ₊₂ are calculated (fifth step S5).

That is, a point separated from the measurement point Pi by the pitch 1 in the X-axis direction and half the weaving width WD (free width) in the -Y-axis direction is set as the next weaving point Qi ₊₂ , and the weaving point is set.
The attitude of the sensor head (20) when moving between Qi _{+1 and} Qi ₊₂ is controlled so that the optical axis A substantially coincides with the normal line Z direction at the measurement point Pi.

In this way, the normal line at each of the measurement points P _{1 to} Pn is sequentially obtained in accordance with the weaving operation of the sensor head (20). Therefore, if the initial local coordinate system at the start point P _S is set for start-up. After that, the next measurement point can be detected automatically following the machined surface.

Further, based on the weaving signal W from the scanning measurement calculation section (40) calculated in this way, the NC control section (40) maintains a constant height from the sensor head (20) to the work and the optical axis A.
Is always maintained substantially perpendicular to the singular line T (the copying surface), the optical sensor head (20) can reliably continue the weaving operation within the tolerance angle θ ₀ .

The above-mentioned weaving operation is repeatedly executed at steps S1 to S5, and ends when the final measurement point Pn is detected.

Finally, the copy measurement calculation unit (40) is configured to measure a series of measurement points P ₁ ~
Singular line position and orientation signal C including each coordinate of Pn and orientation data
Is generated and transmitted to the data processing unit (50) (sixth step S6).

At this time, since the normal line Z at each of the measurement points P _{1 to} Pn has already been obtained, this can be used as the posture data on the singular line T, that is, the processing line.

The data processing unit (50) calculates a machining program R for machining a workpiece based on each measurement point data in the singular line position / orientation signal C, and transmits this to the NC control unit (30).

Then, instead of the sensor head (20), a processing head (not shown) that emits a processing laser beam is used for the arm tip (10).
It is attached to a) and the specified processing is performed along the processing line.

Although the sensor head (20) is provided at the arm tip (10a) in the above embodiment, only the light receiving portion is arranged in the vicinity of the processing head to selectively emit the laser light for teaching from the processing head. You may do it.

[Effects of the Invention] As described above, according to the present invention, the first step of calculating the normal line at the measurement point detected on the singular line and the deviation angle between the normal line and the optical axis of the sensor head are calculated. And the third step of comparing the deviation angle with the latitude angle of the sensor head, and when the deviation angle is within the tolerance angle, the posture of the sensor head is not changed and the deviation angle is larger than the latitude angle. If it is larger, the fourth step of changing the attitude of the sensor head so that the optical axis follows the normal line, and the fifth step of calculating the sensor head position and attitude for the next weaving point based on the attitude of the sensor head. And a sixth step of generating a singular line position / orientation signal including position and orientation data of the measurement point, and when scanning and measuring the singular line by the weaving operation, the next weigh is performed according to the normal line at the detected measurement point. Determine the attitude of the sensor head with respect to the moving point,
Since the singular line position / orientation signal including this attitude data is generated, there is an effect that a machining line teaching method that is automatic, high speed, and reliable can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing a processing apparatus to which an embodiment of the present invention is applied, FIG. 2 is an explanatory view showing a weaving operation according to the present invention, and FIG. 3 is an explanatory view showing a measuring point detecting operation according to the present invention. , FIG. 4 is a flow chart for explaining the present invention. (10) …… Processing machine body, (10a) …… Arm tip (20) …… Sensor head, T …… Singular line Q _{1 to} Qn _{+ 1} …… Weaving point P _{1 to} Pn …… Measuring point, C …… Singular line position / attitude signal Z …… Normal line, A …… Optical axis θ …… Displacement angle, θ ₀ …… Margin angle S1 …… First step, S2 …… Second step S3 …… Third step , S4, S4 '... Fourth step S5 ... Fifth step, S6 ... Sixth step In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

(57) [Claims] 1. A sensor head provided at the tip of an arm of a processing machine body is weaved to trace a singular line provided along a machining line of a workpiece and at a measurement point detected on the singular line. A first step of calculating a normal line; a second step of calculating a deviation angle between the normal line and the optical axis of the sensor head; and a second step of comparing the deviation angle with a latitude angle of the sensor head. 3 steps: If the deviation angle is within the tolerance angle, the posture of the sensor head is not changed, and if the deviation angle is greater than the tolerance angle, the optical axis follows the normal line. A fourth step of changing the attitude of the sensor head, a fifth step of calculating the sensor head position and attitude with respect to the next weaving point based on the attitude of the sensor head, and a position of the measurement point. Processing line teaching method and a sixth step of generating a specific line position and orientation signals including fine orientation data.