JPH07303979A - Laser beam machine - Google Patents

Abstract

PURPOSE:To execute the operation equivalent to the relative speed operation of a work to a laser beam machining head by a farm ware in a control device which is the existing hardware so as to reduce the cost without using a relative speed computing element which is a separate hardware. CONSTITUTION:An interpolation part 6 outputs the interpolation signals H1-Hn to interpolate motors 31-3n under the moving command. A primary delay operation part 8 executes the operation of the primary delay to the interpolation signals H1-Hn to output the axial speed signals J1-Jn A reverse interpolation part 9 outputs the head speed signal based on the axial speed signals J1-Jn. The output adjusting signal is outputted from a laser beam control device 10 based on the head speed signal and the laser beam output command to be outputted by the reverse interpolation part 9, the size of the output to be oscillated by a laser beam oscillator 11 is changed according to this output adjusting signal, and the laser beam according to this oscillated output is outputted from a laser beam machining head 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing apparatus used for cutting a workpiece, and in particular, a laser processing head attached to the hand of an articulated robot or the like emits a laser beam to process the workpiece. The present invention relates to a laser processing device.

[0002]

2. Description of the Related Art Conventionally, cutting of a work (work) by a laser beam has been performed in a relationship as shown in FIG. That is, FIG. 3 shows the relationship between the relative speed of the workpiece and the laser light output with respect to the laser irradiation point when processing points A to B. This processing example is disclosed in, for example, Japanese Patent Laid-Open No. 60-231587, and the speed changes drastically in the acceleration / deceleration at the start of processing and in the deceleration area near the processing end point. The processing accuracy is improved by adjusting the output of laser light.

FIG. 4 is a block diagram illustrating a conventional laser processing apparatus. In this laser processing device, the laser light irradiation point is fixed and the workpiece is moved. In the figure, 21
Is a laser oscillating device, 22 is a laser beam, and 23 is a laser beam irradiation point, which irradiates a laser beam onto a workpiece 25 fixed on a workstation 24. The workstation 24 is an XY table, and includes motors 26 and 27 with rotation signal output devices. A control device 28 sends a movement command to the workstation 24 and a laser irradiation command to the laser oscillator 21. Reference numeral 29 is a relative speed calculator that calculates the relative speed of the workpiece 25 with respect to the laser light irradiation point 23 from the rotation output signals from the motors 26 and 27 of the workstation 24. Reference numeral 30 denotes a speed output control device that sets a laser output level for the result calculated by the relative speed calculator 29. The output of the laser beam 22 emitted from the laser oscillation device 21 by the speed output control device 30 is , Controlled according to relative speed.

This laser processing apparatus is an example of planarly processing a workpiece on an XY table. On the other hand, processing a deformed work piece such as a curve or a large work piece,
When processing a workpiece spatially, an articulated robot that can change its posture spatially is used, and a laser processing head that emits laser light is attached to the hand of this robot to process the workpiece. To be

[0005]

A relative velocity calculator is required to calculate the relative velocity between the workpiece and the laser processing head even when the workpiece is machined using an articulated robot or the like. Is. However, in this case, in order to obtain the speed of the hand of the robot, that is, the speed of the laser processing head from the rotation output signals for the number of axes of the robot in the relative speed calculator, since the mechanism of the robot is complicated, an XY table or the like is used. Differently, complicated operations are required. Therefore, in order to calculate this in real time at high speed, a high-speed CPU and a calculation IC are indispensable, the relative speed calculator becomes expensive, and the cost of the laser processing apparatus increases.

The present invention has been made in order to solve such a problem, and an object thereof is to perform a calculation corresponding to a relative speed calculation between a workpiece and a laser processing head.
It is an object of the present invention to provide a cheaper laser processing apparatus by operating the firmware in the control device, which is existing hardware, instead of using the relative speed calculator, which is hardware separately.

[0007]

In order to achieve such an object, a first invention (an invention according to claim 1) of the invention is to move a robot in response to a movement command which is a command to move the robot. Interpolation signal H for interpolating 1st to nth motors
_{1 to} H _n are output from the interpolating means, the interpolating signals H _{1 to} H _n output from the interpolating means are subjected to a first-order lag calculation process, and the axis velocity signals J _{1 to} J _n are output from the first-order lag calculating means. Based on the axis velocity signals J _{1 to} J _n output by the first-order delay calculation means, a head speed signal that is the speed of the laser processing head is output from the inverse interpolation means, and the head speed signal output by this inverse interpolation means and the laser are oscillated. An output control signal is output from the laser control means on the basis of a laser output command which is a command to change the magnitude of the output oscillated by the laser oscillating means according to the output control signal output from the laser control means. The corresponding laser beam is emitted from the laser processing head.

A second invention (the invention according to claim 2) decodes a machining program stored in a memory and decodes a movement command which is a command to move a robot and a laser output command which is a command to oscillate a laser. Output from the section,
Interpolation signals H ₁ to interpolate _first to nth motors for moving the robot in response to the movement command output from the decoding unit
H _n is output from the interpolating unit, and the interpolation signals H _{1 to} H _n output from the interpolating unit are subjected to a first-order lag calculation process and the axis velocity signal J
_{1 to} J _n are output from the primary delay calculation unit, and a head speed signal, which is the speed of the laser processing head, is output from the inverse interpolation unit based on the shaft speed signals J _{1 to} J _n output from the primary delay calculation unit, An output control signal is output from the laser control device based on the head speed signal output from the inverse interpolation unit and the laser output command output from the decoding unit, and the laser oscillator oscillates in accordance with the output control signal output from the laser control device. The magnitude of the output is changed so that the laser processing head emits laser light corresponding to the oscillation output.

A third invention (the invention according to claim 3) decodes a machining program stored in a memory and decodes a movement command which is a command to move a robot and a laser output command which is a command to oscillate a laser. Output from the section,
Interpolation signals H ₁ to interpolate _first to nth motors for moving the robot in response to the movement command output from the decoding unit
H _n is output from the interpolation unit, and the first to n- _th signals are output based on the interpolation signals H _{1 to} H _n output from the interpolation unit and the position signals P _{1 to} P _n indicating the rotation angles of the first to n-th motors. The control signals S _{1 to} S _n for servo-controlling the motor are output from the servo unit, and the interpolation signals H _{1 to} H _n output from the interpolation unit are subjected to a first-order lag calculation process to output the axis velocity signals J _{1 to} J _n to the primary order. Interpolation signals H _{1 to} H _n output from the delay calculation unit and output from this interpolation unit
First-order lag calculation processing is performed to output the shaft speed signals J _{1 to} J _n from the first-order lag calculation unit, and the speed of the laser processing head is calculated based on the shaft speed signals J _{1 to} J _n output from the first-order lag calculation unit. A certain head speed signal is output from the inverse interpolation unit, and an output adjustment signal is output from the laser control device based on the head speed signal output from this inverse interpolation unit and the laser output command output from the decoding unit. The size of the output oscillated by the laser oscillator is changed according to the output control signal to be output, and the laser beam corresponding to the oscillated output is emitted from the laser processing head.

[0010]

[Action] Therefore, according to the present invention, the interpolation signal H ₁ to H _n calculation of first-order lag to have done shaft speed signal J ₁ through J _n output receive movement command is made, the shaft speed signal A head speed signal is created based on J _{1 to} J _n , an output adjustment signal is created based on this head speed signal and a laser output command, and laser light is emitted from the laser processing head in accordance with this output adjustment signal.

[0011]

EXAMPLES The present invention will now be described in detail based on examples. FIG. 1 is a block diagram of a laser processing apparatus showing an embodiment of the present invention. In the figure, 1 is an articulated robot, 2 is a laser processing head attached to the hand of the robot 7, and 3 _{1 to} 3 _n are first to first robots for moving the robot 1.
The nth motor, 4 is a memory in which a machining program in which the operation of the robot or laser is described is stored, and 5 is a movement command which is a command for decoding the machining program in the memory 4 to move the robot 7 and oscillates a laser. A decoding unit 6 which outputs a laser output command which is a command to make the motor 6 receive the movement command output from the decoding unit 2 and an interpolation unit which outputs interpolation signals H _{1 to} H _n for interpolating the motors 3 _{1 to} 3 _n , 7 based on the position signal P ₁ to P _n which indicates the rotation angle of the interpolated signal H ₁ to H _n and the motor 3 ₁ to 3 _n outputs of the interpolation unit 6 motors 3 ₁ -
The 3 _n is a servo unit that outputs a control signal S ₁ to S _n to the servo control.

Reference numeral 8 denotes the interpolation signals H _{1 to} H output by the interpolation unit 6.
_A first-order lag calculation unit that performs a first-order lag calculation process on _n and outputs axis speed signals J _{1 to} J _n , and 9 is a laser processing head 2 based on the shaft speed signals J _{1 to} J _n output from the first-order lag calculation unit 8. Inverse interpolation unit that outputs a head speed signal that is the speed of 1
Reference numeral 0 denotes a laser control device that outputs an output adjustment signal based on the head speed signal output from the inverse interpolation unit 9 and the laser output command output from the decoding unit 5, and 11 indicates the output adjustment signal output from the laser control device 10. A laser oscillator that oscillates by changing the magnitude of the output and causes the laser processing head 2 to emit a laser beam according to the oscillated output. The memory 4, the decoding unit 5, the interpolation unit 6, the servo unit 7, the first-order delay calculation unit. A control device 12 that controls the robot 1 and the laser control device 10 is configured by 8 and the inverse interpolation unit 9.

Next, the operation of this laser processing apparatus will be described with reference to FIG. In FIG. 1, the decoding unit 5 decodes the machining program in the memory 4 and outputs a movement command indicating the movement amount L and movement speed V of the hand of the robot 1 and a laser output command for oscillating a laser. Interpolator 6
Are motors 3 _{1 to} 3 _n for moving the robot 1 according to the movement command (movement amount L, movement speed V) received from the decoding unit 5.
Output interpolation signals H _{1 to} H _n for interpolating. That is,
Interpolation signals H _{1 to} H _n are obtained by the following procedure.

From the movement command (movement amount L, movement speed V), the rotation angle θi and rotation speed vi of each motor 3 of the robot 1
Ask for. θi = f1 (L) (1) vi = f2 (V) (2) where i = 1 to n, L = (X, Y, Z), V = (V
x, Vy, Vz), f1: a function for determining the rotation angle θi of each motor 3 of the robot 1 from the movement amount L, and a function determined by the mechanical structure of the robot 1, f2: rotation of each motor 3 of the robot 1 from the moving speed V It is a function that determines the velocity vi, and is a function determined by the mechanical structure of the robot 1. Figure 2
The relationship between θi and vi is shown in (a). Next, in order to alleviate shocks when the robot 1 is driven and stopped, the rising and falling portions of the speed vi are tilted and used as the interpolation signal Hi. FIG. 2B shows the interpolation signal Hi.

The interpolation signals H _{1 to} H _n are _given to the servo section 7 and the first-order delay calculating section 8. The servo unit 7, control receives the position signals P ₁ to P _n which indicates the rotation angle of the interpolated signal H ₁ to H _n and the motor thirty-one to three _n from the interpolation unit 6 signals S ₁ to S
_n is output to servo-control the motors 3 _{1 to} 3 _n . Further, as shown in FIG. 2, generally, if a first-order delay calculation is performed on the waveform of the interpolation signal Hi in FIG.
Since the waveform of the axis speed signal Ji, which is the speed of each motor 3 of the robot 1 as described above, is obtained, the first-order lag calculation unit 8 includes the interpolation unit 6
The interpolation signals H _{1 to} H _n , which are the outputs of the above, are input, the first-order lag calculation processing is performed, the axis speed signals J _{1 to} J _n , which are the speeds of the motors 3 of the robot 1, are converted, and the inverse interpolation unit 9 is supplied. Output.

The inverse interpolator 9 outputs the first-order lag calculator 8 and outputs the shaft speed signal J indicating the speed of each motor 3 of the robot 1.
_{Using 1 to} J _n , the moving speed of the hand of the robot 1, that is, the moving speed of the laser processing head 2, Vh, is obtained as follows. That is, Vh = If (vji) is calculated. Here, Vh: moving speed of the hand of the robot 1, that is, moving speed of the laser processing head 2, vji: robot 1
Shaft speed signals Ji (i = 1 to n) of each motor 3 of If, If:
A function that determines the moving speed Vh of the laser processing head 2 from vji and that is determined by the mechanical structure of the robot 1.

Further, the inverse interpolation unit 9 is provided with the laser processing head 2
Vh, which is the moving speed of the laser, is output to the laser control device 10 as a head speed signal. The laser control device 10 receives the laser output command output from the decoding unit 5 and the head speed signal output from the inverse interpolation unit 9, and adjusts the output level of the laser oscillator 11 according to the change in the head speed signal. Output the output control signal. The laser oscillator 11 receives an output control signal output from the laser control device 10 and oscillates by changing the magnitude of the output, and the laser processing head 2 held at the hand of the robot 1 oscillates the output of the laser oscillator 11. A laser beam corresponding to is emitted to cut the workpiece.

[0018]

As is apparent from the above description, according to the present invention, the interpolation signal H output upon receiving a movement command is output.
_The first-order delay calculation processing is performed on _{1 to} H _n , and the axis speed signal J ₁
~ J _n are created, a head speed signal is created based on the axis speed signals J _{1 to} J _n , an output adjustment signal is created based on the head speed signal and the laser output command, and in response to the output adjustment signal Laser light is emitted from the laser processing head, and the calculation corresponding to the relative speed calculation between the workpiece and the laser processing head is controlled by the existing hardware, not by a separate hardware relative speed calculator. The firmware in the device can be used for the calculation, and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of a laser processing apparatus showing an embodiment of the present invention.

FIG. 2 is a diagram showing the waveform of each signal for explaining the operation of this laser processing apparatus.

FIG. 3 is a diagram illustrating a relationship between a relative speed of a workpiece and a laser light output.

FIG. 4 is a configuration diagram illustrating a conventional laser processing apparatus.

[Explanation of symbols]

1 ... robot, 2 ... laser processing head, 3 ₁ to 3 _n ... motor, 4 ... memory, 5 ... decoding unit, 6 ... interpolation unit, 7 ... servo unit, 8 ... primary delay arithmetic unit, 9 ... inverse interpolation unit, 10 ... Laser control device, 11 ... Laser oscillator, 12 ... Control device.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location G05B 19/18

Claims (3)

[Claims] 1. A laser processing apparatus for processing a workpiece by emitting a laser beam from a laser processing head attached to a hand of a robot, for moving a robot in response to a movement command which is a command for moving the robot. and interpolating means for outputting an interpolated signal H ₁ to H _n of interpolating 1 motor of the n, shaft speed signal J ₁ performs arithmetic processing of the output interpolated signal H ₁ to H _n the first-order lag of the interpolation means - First-order delay calculating means for outputting J _n, and axis speed signals J _{1 to} J _n output by the first-order delay calculating means.
An inverse interpolation means for outputting a head speed signal that is the speed of the laser processing head based on the above, and an output adjustment signal based on the head speed signal output by this inverse interpolation means and a laser output command that is a command to oscillate the laser. Laser control means for outputting, and laser oscillation means for oscillating by changing the magnitude of the output according to the output control signal output by the laser control means, and causing the laser processing head to emit laser light according to the oscillation output. A laser processing apparatus comprising: 2. In a laser processing apparatus for processing a workpiece by emitting a laser beam from a laser processing head attached to a hand of a robot, a memory for storing a processing program and a processing program stored in this memory are decoded. A decoding unit that outputs a movement command that is a command to move the robot and a laser output command that is a command to oscillate a laser, and first to nth n-th moving units that move the robot in response to the movement command output from the decoding unit. Interpolation signal H to interpolate the motor
₁ and interpolation unit for outputting to H _n, and an output interpolated signal H ₁ to H _n primary outputs a shaft speed signal J ₁ through J _n performs arithmetic processing of the first-order lag to the lag operation unit of the interpolation section, the An inverse interpolator that outputs a head velocity signal that is the velocity of the laser processing head based on the axis velocity signals J _{1 to} J _n output by the first-order lag calculator, and a head velocity signal output by the inverse interpolator and the decoding. A laser control device that outputs an output control signal based on a laser output command output by the laser control unit, and oscillates by changing the magnitude of the output according to the output control signal output by the laser control device A laser processing apparatus comprising: a laser oscillator that causes a laser beam to be emitted from the laser processing head. 3. A laser processing apparatus for processing a workpiece by emitting a laser beam from a laser processing head attached to a hand of a robot, and a memory for storing a processing program and a decoding of the processing program stored in this memory. A decoding unit that outputs a movement command that is a command to move the robot and a laser output command that is a command to oscillate a laser, and first to nth n-th moving units that move the robot in response to the movement command output from the decoding unit. Interpolation signal H to interpolate the motor
_{1 to} H _n, and interpolation signals H _{1 to} H _n output from this interpolation unit and position signals P _{1 to} P _n indicating rotation angles of the first to nth motors.
And a servo unit that outputs control signals S _{1 to} S _n that servo-control the first to n-th motors, and a first-order delay calculation process is performed on the interpolation signals H _{1 to} H _n output from the interpolation unit. a primary delay arithmetic unit for outputting a shaft speed signal J ₁ through J _n, and outputs a head speed signal is a speed of the laser processing head on the basis of the shaft speed signal J ₁ through J _n outputs of the first-order lag calculation unit An inverse interpolation unit, a laser control device that outputs an output adjustment signal based on a head speed signal output from the inverse interpolation unit and a laser output command output from the decoding unit, and an output adjustment signal output from the laser control device. A laser processing apparatus according to claim 1, further comprising: a laser oscillator that oscillates by changing the magnitude of its output and causes the laser processing head to emit laser light according to the oscillating output.