JP4973982B2 - Galvano scanner system and control method - Google Patents

Description

  The present invention relates to a galvano scanner system that performs laser processing using a galvanometer and a control method thereof.

A galvanometer scanner system consisting of a galvanometer, a galvanometer controller that drives the galvanometer, and a laser driving device is used for creating barcodes, processing minute wires, etc., and processing by heating and sublimating an object with a laser It is. As bar code and wiring processing have become more accurate, it has been potentially desired to produce a uniform line width. For this reason, the operation command to the galvanometer is performed by the motion controller analyzing the motion program input to the controller and outputting the operation speed of the mirror. In order for the mirror to actually start operation from the timing when the command is output from the motion controller to the galvanometer, a certain delay operation occurs due to a command delay from the controller to the servo driver. The controller can set a delay time for correcting this delay, and this delay time is set in accordance with the actual operation delay time of the galvanometer. In order to implement such a method, three methods have been proposed as conventional galvanometer controllers. The first is a method of delaying the irradiation start time by setting a laser off delay parameter (see, for example, Patent Document 1). The second is a method of irradiating a laser only during a constant speed driving period of an operation command to the galvanometer (see, for example, Patent Document 2). Third, as a laser processing apparatus, a controller that generates a movement command for controlling the laser irradiation position and a laser drive command for controlling the output of the laser is used (for example, a patent). Reference 3).
A first conventional galvanometer controller will be described with reference to FIG. 201 indicates a command speed from the controller to the servo driver. 202 indicates the speed of the galvanometer operating after a certain delay time. Reference numeral 203 denotes a laser output. 204 is a laser-on-delay parameter for setting how much the laser irradiation start is delayed in consideration of a delay such as a command from the controller to the servo driver. Reference numeral 205 denotes a laser off delay parameter for setting how much the laser irradiation end is delayed with respect to the controller command.
Next, the operation will be described. The laser on delay parameter 205 is set to suppress laser irradiation when the mirror is stopped. On the other hand, at the end of marking, the controller command is completed, but the mirror completes its operation with a delay. The laser irradiation is continued until the mirror operation is actually stopped by adjusting the off-delay parameter 205. For this reason, in the acceleration / deceleration region of the mirror speed, by irradiating more laser, the width of the processing mark becomes thicker in the acceleration / deceleration region, and the width can be uneven.
In addition, as a second conventional example, the galvanometer is controlled so that the galvanometer starts to operate before the marking line drawing start point, and the galvanometer operates even when the marking line drawing end point is exceeded. .
Thus, the conventional controller is designed to adjust the laser output start timing and the actual operation start timing of the galvanometer by setting the delay time from the operation command until the actual operation of the galvanometer starts. ing. The laser output at this time is output with the intensity specified by the motion program. For example, the specified laser intensity is always output even in the acceleration interval until the command speed is reached and also in the deceleration interval when positioning to the specified position. The setting of the laser intensity at this time is controlled by the output voltage value in the case of an analog command laser, and is determined by the PWM output width with respect to the PWM cycle in the case of a laser with PWM irradiation.
As a third embodiment, FIG. 10 shows a laser processing apparatus using a galvanometer.
Laser processing technology using a galvanometer is used for processing high-density wiring circuit boards, etc., and irradiates laser light reflected by a galvanometer mirror attached to the galvanometer onto the irradiation surface of the workpiece. Alternatively, it is processed by evaporation.
In the figure, 11 is a galvanometer mirror, and 12 is a galvanometer that rotates the galvanometer mirror. The galvanometer 12 is connected to an encoder 13 that is a position detector and a drive device 14. The galvanometer mirror 11 is rotated according to the drive current from the drive device 14, and the rotation angle is detected by the encoder 13. It is given to the drive device 14. Reference numeral 15 denotes a controller which gives an irradiation position command to the driving device 14, and the driving device 14 outputs a driving current to the galvanometer based on the irradiation position command and position information from the encoder 13. A laser oscillator 16 outputs a laser beam to the galvanometer mirror 12. A central processing unit 21 of the controller 15 generates an irradiation position command at regular intervals using the controller software 22 in response to the processing command, and commands the driving device 14. Also, a laser output command (laser power command) is generated and commanded to the laser signal generation circuit 23. The laser output command is adjusted at an interval of the irradiation position command cycle of the controller so as to make the degree of processing uniform. The laser signal generation circuit 23 generates a laser drive signal based on the laser output command from the central processing unit 21 and outputs it to the laser oscillator.
In this way, by adjusting the laser output command in the cycle of the irradiation position command from the controller to the galvanometer mirror, there is a method for making the irradiation energy per unit time of the laser as uniform as possible in the change in the moving speed of the laser irradiation point. Proposed. (For example, refer to Patent Document 1).
JP-A-2-299786 (page 5-7, FIG. 1) JP-A-7-290257 (FIGS. 2 and 3) Japanese Patent Laid-Open No. 9-285882 (page 8, FIG. 1)

In the conventional galvano controller, there is a certain delay between the time when the speed command is sent from the controller to the servo driver and the actual operation of the mirror, but this delay is ignored and the command from the controller is ignored. When laser irradiation is started synchronously, the laser is irradiated for the time required until the mirror actually operates, and there is a potential problem that the marking object is damaged at the start of marking. So far, measures have been taken to solve this problem. The conventional examples are also means for solving potential problems, but when issuing a movement command to the galvanometer, a laser output command is also issued at the same time, but at this time, the commanded speed is reached. The laser is always output at the specified intensity even in the acceleration interval up to and the deceleration interval when positioning to the specified position. In FIG. 2, 206 indicates the laser irradiation amount per unit time. As shown at 206, the acceleration and deceleration sections move at a speed slower than the commanded speed, and therefore the laser irradiation time in the acceleration / deceleration section is a constant speed at the commanded speed. Since the laser irradiation time becomes longer in the operation section, there is actually a problem that the marking start part and the end part swell as shown in 207 with respect to the ideal machining trace shown in 208. It was happening.
In addition, the galvanometer operation is started from a point before the marking line drawing start point, and even if the galvanometer is controlled to operate even when the marking line drawing end point is exceeded, the galvanometer is fixed during the acceleration / deceleration period. Since the irradiation is performed with the laser intensity in the fast period, there is a problem that the marking start portion and the end portion become a processing mark that swells.
FIGS. 11 and 12 are explanatory views of the operation of the laser processing apparatus of the third conventional example. 11A is a position command given from the controller 21 to the driving device 14, FIG. 11B is a moving speed of the laser on the irradiation surface, and FIG. 11C is a laser signal generated from the central processing unit of the controller 14. The laser output command given to the circuit 23, FIG. 11 (d), represents the laser power applied to the irradiation surface. Note that the software control period of the controller 14 is 250 μs. In the figure, it is assumed that there is a time lag of 250 μs between the timing at which the position command is given to the drive device and the actual movement, and the central processing unit issues the laser power command with a shift of one cycle from the position command. The magnitude of the laser power is adjusted by calculating every period from the ratio of the current command speed to the target speed. As a result, from FIG. 11 (b) and FIG. 11 (d), the laser power also fluctuates corresponding to the speed fluctuation.
However, the method of changing the output of the laser light in accordance with the speed change section such as the acceleration / deceleration section depends on the cycle in which the controller outputs the movement command to the galvano mirror. Therefore, if the command cycle from the controller is long As a result, the laser output adjustment interval also becomes long, and precise laser output adjustment cannot be performed. On the other hand, if the cycle of the irradiation position command from the controller to the galvanometer mirror is shortened, the laser output can be adjusted at a faster cycle, but in reality, the processing performance of the CPU is limited, and the cycle of the command is There was a problem that the speed could not be increased easily.
FIG. 12 shows a case where the time lag between the timing at which the position command is given to the driving device and the actual movement is 300 μs and is not proportional to the control cycle of the controller 14. Since the timing at which the central processing unit issues the laser power command is the control cycle of the controller software, as shown in FIG. 6 (d), the movement start timing and the laser irradiation timing are shifted, affecting the degree of processing. There was a problem that it would end up.
The present invention has been made in view of such problems, and a galvano control controller that does not cause laser irradiation unevenness at the laser processing start point and end point regardless of the acceleration / deceleration time and the responsiveness of the galvanometer. The purpose is to provide.

The invention according to claim 1 is a two-axis galvano scanner orthogonal to each other and driven by a servo driver, a laser device for irradiating the galvano scanner with laser light, and the servo driver and the laser device synchronized with each other. a galvanometer scanner system comprising a controller for controlling, said controller includes a controller software, a central processing unit, and a laser signal generating circuit for generating a laser drive signal for driving the laser device The central processing unit gives a position command to the servo driver and increments a laser power command and an increment to the laser signal generation circuit in a software control cycle that is a control cycle of the controller software so as to synchronize with the position command. Value command, and the controller software The control signal is a control cycle of the laser signal generation circuit that is shorter than the software control cycle as a value obtained by dividing the difference value between the current laser power command and the target laser power command by the software control cycle. A value obtained by multiplying a hardware control cycle is calculated, and the laser signal generation circuit generates the laser drive signal by adding the increment value command to the laser power command for each hardware control cycle, and the laser device it is shall be output to.
The invention described in 請 Motomeko 2 synchronizes the galvanometer scanner biaxial driven by respective servo driver perpendicular to each other, and a laser device for irradiating a laser beam to the galvano scanner, the laser device and the servo driver And a controller that controls the galvano scanner system, wherein the controller includes controller software, a central processing unit, and a laser signal generation circuit that generates a laser drive signal for driving the laser device. The central processing unit supplies a position command to the servo driver and a laser is supplied to the laser signal generation circuit at a software control cycle that is a control cycle of the controller software so as to synchronize with the position command. A power command and an increment value command. La software, as the incremental value command is the control cycle of the current laser power command and a target short the laser signal generating circuit from the software control cycle the differential value of the laser power command to a value obtained by dividing by the software control period calculates the value obtained by multiplying the hardware control cycle, the laser signal generating circuit, said increment command by adding to the laser power command to generate the laser drive signal to the hardware control for each cycle, the laser device those you output to.

According to the invention described in claim 1 Contact and 2, it is possible to update the laser drive signal in a period shorter than the control cycle of the software controller for speed variations, higher precision processing can be realized. The resolution of the laser signal generating circuit, Ru required der the command cycle equal or greater resolution of the drive apparatus for performing final command to the galvanometer mirror.

  Hereinafter, specific examples of the method of the present invention will be described with reference to the drawings.

  FIG. 1 shows the configuration of a galvano scanner device that implements the method of the present invention. In the figure, reference numeral 101 denotes a galvanometer, which is composed of two axes for the X axis and the Y axis. Reference numeral 105 denotes a laser device that actually emits a laser, and performs laser irradiation in response to a command from the controller 103. A servo driver 102 controls the operation of the galvanometer 101 and controls the galvanometer 101 in response to an instruction from the controller 103. Reference numeral 103 denotes a controller that gives instructions to the two servo drivers to draw a specified shape. The controller 103 controls a command to the servo driver 102 and ON / OFF of laser irradiation to the laser device 105. Since the command to the servo driver 102 and the command to the laser device 105 are issued using the sampling period of the CPU (not shown) of the controller 103, the servo driver 102 and the laser device 105 can be controlled synchronously. Reference numeral 104 denotes a host PC for performing operation commands to the controller 103, reading / writing parameters, acquisition of controller status, and the like. A user can operate the controller 103 from the host PC 104.

FIG. 3 shows a block diagram of a controller for realizing the present invention. Reference numeral 301 denotes a motion program for describing laser irradiation and a movement command of the laser irradiation destination. A program analysis unit 302 analyzes the motion program, and converts the motion program into intermediate data so that it can be easily processed. Reference numeral 303 denotes a command creation unit that calculates operation command data for each command cycle to the galvanometer based on the intermediate data analyzed by the program. Reference numeral 304 denotes a result calculated by the command creation unit. Reference numeral 306 denotes a laser output delay processing unit that manages the output delay of the laser. Reference numeral 305 denotes a laser output command to the laser device. Reference numeral 307 denotes a laser output delay time in which the operation command timing to the galvanometer and the actual operation timing of the galvanometer are set as the delay time. 309 is a movement amount until the start of laser output, and 310 is a remaining movement amount until the end of laser output. Reference numeral 308 denotes a laser output determination unit that determines the laser output timing to the laser output delay processing unit based on 309 and 310.
The laser on / off control command described in the motion program, the laser intensity and the operation command to the galvanometer are converted into intermediate data that the program analysis unit 302 can easily process in the operation command generation unit, and the command generation unit 303 performs the processing. Ask.

FIG. 5 shows a processing flowchart that operates in a cycle (interpolation cycle) for issuing a command to the servo driver. First, the command creation unit is activated, and the command creation unit ST501 creates a command position for the servo driver, and creates a movement amount that has already moved and a remaining movement amount to the target position. Next, the laser output determination unit ST502 operates to determine whether or not laser output is performed based on the already moved movement amount created by the command creation unit ST501 and the remaining movement amount to the target position. Finally, the laser output delay processing unit ST503 performs laser output according to the presence / absence of the laser output determined by the laser output determination unit.
The part where the present invention differs from Patent Document 1 is a part having a function of determining the laser output section based on the movement amount from the start of movement in the laser irradiation section and the remaining movement amount to the target position.

Next, a procedure when the user actually irradiates and processes the laser will be described.
First, the user creates a machining program on the host PC so as to irradiate the designated location with laser.
Next, the movement distance until the start of laser irradiation and the remaining movement distance until the end of laser irradiation, which are parameters of the controller, are set. Finally, the machining program created on the host PC is sent to the controller for execution.
The controller performs laser irradiation according to the parameters set by the host PC.
FIG. 4 shows the relationship between laser irradiation, command, and actual drive pattern in the present invention. 201, 202, 203, and 204 are the same as those in FIG. When starting a command from the controller to the servo driver, the laser is not irradiated until the value set as the movement amount 309 until the start of laser irradiation is reached. Here, the distance obtained from the acceleration time to reach the command speed 201 is set. Laser irradiation is performed with a delay of the time required for movement by the movement amount 309 set by the parameter and the time of the laser on delay parameter 204 set by the controller.
On the other hand, the laser-off timing is compared with a laser-off delay parameter set in advance in the controller when the command remaining movement amount 310 is reached in a constant speed region. Here, the command remaining movement amount 310 is set to a distance necessary for deceleration. The deceleration time obtained from the remaining movement amount 310 and the command speed 201 is compared with the laser off delay parameter 205 to determine the laser off delay parameter. When 205 becomes the deceleration time or less, the laser irradiation is stopped.
Thus, by setting the distance for the acceleration / deceleration section as a parameter of the controller, it becomes possible to perform laser irradiation only in the constant speed section.

FIG. 6 shows a flowchart for performing laser irradiation section control in the laser output determination unit of the controller.
The laser output determination unit compares the movement amount already moved by the command generation unit with the movement amount until the laser output set by the parameter is started (ST601). If it is not operating for the specified amount of movement, the laser output request to the laser output delay processing unit is turned off (ST603). If it is already operating for the specified amount of movement, the laser output request to the laser output delay processing unit is Is turned on (ST602). Also, in ST604, the remaining movement amount at the end of laser output is compared with the current remaining movement amount, and when the remaining movement amount is equal to or less than the set remaining movement amount at the end of laser output, the laser output delay unit is connected. The laser output request is turned off (ST605). The laser output delay processing unit starts and stops laser output after the time set as the laser output delay time has elapsed.

  In this way, it is possible to set which section of the laser beam is irradiated with respect to the total amount of movement with parameters, and the controller performs on / off control of the laser in comparison with the amount of movement and the remaining amount of movement during operation. By adjusting the parameters, it is possible to perform laser control only in a constant speed section regardless of the acceleration / deceleration time and the galvanometer response, and laser irradiation unevenness at the start and end points of laser irradiation is eliminated.

FIG. 7 is a configuration example of a laser processing apparatus for performing the method of the present invention. The difference from the first embodiment is the laser output command that the central processing unit 21 of the controller 14 gives to the laser signal generation circuit 23, and there are three types of laser power command, (laser power) increment value command, and power delay. is there.
8A is a position command given from the controller 21 to the driving device 14, FIG. 8B is a moving speed of the laser on the irradiation surface, and FIG. 8C is a central processing unit of the controller 14. The laser output command given from 21 to the laser signal generation circuit 23, FIG. 8D, is the laser power applied to the irradiated surface.
The operation will be described with reference to FIGS. The central processing unit 21 of the controller 14 gives a laser power command, an increment value command, and a power delay to the laser signal generation circuit 23 in a software control cycle. The laser power command is a laser power command value, and is “0” at the initial time (250 μs). The increment value command is a laser power increment value added to the laser power command in units of control periods of the laser signal generation circuit. The controller software calculates the laser power increment based on Equation (1).

Laser power increment value =
(Target laser power-current laser power) / (position command cycle / laser signal generation circuit control cycle) Equation 1

The laser power increment value is obtained by dividing the difference value between the current laser power command and the target value of the laser power in accordance with the resolution (hardware control cycle) of the laser signal generation circuit 23 with respect to the position command cycle. Become.
For example, when the current laser power is “0”, the target value of the laser power is “100”, the position command cycle is 250 μs, and the hardware control cycle of the laser signal generation circuit 23 is “10 μs”, the incremental value command is “100/25 = 4”.
The power delay is a delay when the laser signal generation circuit 23 outputs a laser drive signal to the laser oscillator 16 and is “0” in FIG.
The laser signal generation circuit 23 adds the increment value “4” to the laser power command “0” for each control period of the laser signal generation circuit, generates a laser drive signal, and outputs the laser drive signal to the laser oscillator 25. After 25 additions, the final value continues to be output. When a new command is received in the next controller software control cycle, similarly, a laser drive signal is generated for each control cycle of the laser signal generation circuit.
Thus, when commanding the laser output command to the laser signal generation circuit of the controller, the difference value between the current laser power command and the current laser power command is divided according to the resolution of the laser signal generation circuit, and the divided value Is supplied to the laser signal generation circuit as a power increment value, so that the laser signal generation circuit adds the power increment value for each control period of the laser signal generation circuit to generate a laser power signal and outputs it to the laser oscillator. Therefore, since the laser drive signal can be updated at a cycle shorter than the control cycle of the software of the controller, higher-accuracy machining can be realized with respect to speed fluctuations.

FIG. 9 is a diagram showing the operation of the embodiment of claim 2 of the present invention. Like FIG. 8, FIG. 9 (a) shows the position command given from the controller 21 to the drive device 14, and FIG. 9 (b). Is the moving speed of the laser on the irradiated surface, FIG. 9C is a laser output command given from the central processing unit 21 of the controller 14 to the laser signal generating circuit 23, and FIG. 9D is irradiated to the irradiated surface. Laser power.
Next, an operation when a time lag is inserted will be described with reference to FIGS. In FIG. 9, in addition to the conditions in FIG. 8, it is assumed that there is a time lag of 280 μs between the timing at which the position command is given to the driving device and the actual movement. In this case, as in the case of FIG. 8, the laser power command is “0” and the increment value command is “4” as in the case of FIG. On the other hand, the power delay value is set to “30” to match the time lag between the position command and the actual movement.
In consideration of power delay, the laser signal generation circuit 23 adds the increment value “4” to the laser power command “0” every control cycle of the laser signal generation circuit 30 μs after the input from the central processing unit. A laser drive signal is generated by addition and output to the laser oscillator 16.
In addition, when the galvanometer starts to move from the stop state, if the laser power command “0” is output, the laser power at the start of the movement becomes 0, which is an unprocessed part. Therefore, the movement set on the controller side The laser power value at the start is output at the moment when the galvanometer starts moving from the stopped state and the moment when the galvanometer enters the stopped state from the moving state. The controller software calculates the laser power increment value at the start and end of movement based on equations (2) and (3).

Laser power increment at the start of movement =
(Target laser power-laser power at the start of movement) / (position command cycle / laser signal generation circuit control cycle) Equation 2

Laser power increment at the end of movement =
(Laser power at end of movement-present laser power) / (position command cycle / laser signal generation circuit control cycle) Equation 3

As described above, when a laser output command is commanded to the laser signal generation circuit of the controller, a power delay time is commanded in addition to the laser power command and the increment value command, and the laser signal generation circuit receives the power delay from the time when the output command is received. Since a laser drive signal is output to the laser oscillator after a lapse of time, higher-accuracy machining can be realized even for a time lag that is shorter than the control period of the controller software.
When the speed changes from the acceleration time to a constant speed, the acceleration speed increases according to the increment value command. When the constant speed is detected from the encoder signal, the laser is irradiated with a constant intensity.
At the time of deceleration, if the off-delay parameter becomes equal to or less than the remaining movement amount, the laser intensity decreases according to the decrease value command. By doing in this way, a more highly accurate process is realizable with respect to a speed fluctuation.

The figure which shows the structure of the galvano scanner system of this invention Timing chart showing galvano operation command and laser output command in the conventional method Software block of controller in the present invention Timing chart showing galvano operation command and laser output command in the present invention Processing flowchart that operates at the command payout cycle to the servo driver Flow chart of laser output determination unit Configuration diagram of a galvano scanner system showing an embodiment of the present invention Operation explanatory diagram of the second embodiment of the present invention Operation explanatory diagram of the third embodiment of the present invention Configuration diagram of a conventional galvo scanner system Example of operation to adjust laser power according to conventional moving speed Example of operation when time delay is set for conventional laser irradiation

Explanation of symbols

11 Galvanometer mirror 12 Galvanometer 13 Encoder 14 Driving device 15 Controller 16 Laser oscillator 21 Central processing unit 22 Controller software 23 Laser output generation circuit 101 Galvanometer 102 Servo driver 103 Controller 104 Host PC
105 Laser Device 201 Command Speed 202 Mirror Speed 203 Laser Output 204 Laser On Delay Timer 205 Laser Off Delay Timer 206 Laser Irradiation Amount per Unit Time 207 Machining Trace 208 by Conventional Control Method Ideal Machining Trace 301 Motion Program 302 Program Analysis Unit 303 Command creation unit 304 Operation command to driver 305 Laser output line 306 Laser output delay processing unit 307 Laser output delay time 308 Laser output determination unit 309 Amount of movement until start of laser output 310 Amount of remaining movement until end of laser output 401 Processing marks in

Claims (2)

Galvanometer scanner with a galvanometer scanner biaxial driven by respective servo driver perpendicular to each other, and a laser device for irradiating a laser beam to the galvano scanner, and a controller for controlling in synchronism the laser device and the servo driver a system,
The controller is
Controller software,
A central processing unit;
A laser signal generation circuit for generating a laser drive signal for driving the laser device;
With
The central processing unit gives a position command to the servo driver and synchronizes with the position command with a software control cycle that is a control cycle of the controller software, and a laser power command and an increment value command to the laser signal generation circuit. And give
The controller software uses a control cycle of the laser signal generation circuit shorter than the software control cycle as a value obtained by dividing the difference value between the current laser power command and the target laser power command by the software control cycle as the increment value command. Calculate a value multiplied by a hardware control cycle,
Galvano scanner system the laser signal generating circuit, said increment command by adding to the laser power command to the hardware control for each cycle to generate the laser driving signal, characterized by also be output from the laser device . A galvano scanner comprising: a biaxial galvano scanner orthogonal to each other and driven by a servo driver; a laser device that irradiates the galvano scanner with laser light; and a controller that controls the servo driver and the laser device in synchronization. A system control method comprising:
The controller is
Controller software,
A central processing unit;
A laser signal generation circuit for generating a laser drive signal for driving the laser device;
With
The central processing unit gives a position command to the servo driver and synchronizes with the position command with a software control cycle that is a control cycle of the controller software, and a laser power command and an increment value command to the laser signal generation circuit. And give
The controller software uses a control cycle of the laser signal generation circuit shorter than the software control cycle as a value obtained by dividing the difference value between the current laser power command and the target laser power command by the software control cycle as the increment value command. Calculate a value multiplied by a hardware control cycle,
The laser signal generating circuit, the hard wear-the incremental value command to control each period and added to the laser power command to generate the laser drive signal, output to Turkey, features and be Ruga to said laser device Control method for the Lubano scanner system.

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