JPH03250683A - Laser device control system - Google Patents

Abstract

PURPOSE:To prevent electrical discharge of a laser device and an output from the same from becoming unstable and from being lowered, respectively, by connecting to a laser device a monitor/measurement part for monitoring and measuring the operation state of the laser device and outputting an optimum control function in a calculation part in response to an output from the monitor/ measurement part, and further controlling the operation state of the laser device based upon the resulting optimum control function. CONSTITUTION:In a monitor/measurement part 22, the electrical discharge state, gas state, or cooling state of a laser device 21 are monitored and measured, and outputted as a state function. The state function thus outputted is subjected to a signal processing such as impedance conversion, etc., in a first conversion part 23 and is fed to a calculation part 24. An optimum control function generated by the calculation part 24 is subjected to a signal processing such as impedance conversion, etc., in a second conversion part 24, and is fed to a control part 26. In the control part 26 electrical discharge conditions, gas conditions, or cooling conditions are determined following the optimum control function, and the laser device 21 is controlled on the basis of the operation state thereof such that its operation state is optimum.

Description

[Detailed Description of the Invention] [-I Features of the Invention] (Industrial Application Field) The present invention relates to a high-output laser device, and in particular, the invention relates to a high-output laser device, and in particular, to The present invention relates to a control system for a laser device that controls the operating state of the laser device.

(Prior art) Generally, in a human-powered laser device, a blower circulates the laser medium gas to the discharge excitation part at high speed.
This laser medium gas is excited by a glow discharge between the anodes, and an optical resonator arranged with an optical axis in a direction perpendicular to the gas flow direction of the laser medium gas generates an L nozzle output. I'm taking it out. An example of this type of L-furnace apparatus is shown in FIG.

That is, inside the laser wind tunnel 1, a discharge excitation section 2, a cooling device 3, and a blower 4 are installed. The discharge excitation unit 2 includes a bottle-shaped cathode 5 divided into a plurality of pieces, a rod-shaped anode 6 disposed opposite to the cathode 5, and an optical axis extending in a direction perpendicular to the direction of a gas flow 7 of a laser medium gas circulated between these electrodes. A stabilizing impedance 9 is provided between one end of the power source 10 and the bottle-shaped cathode 5 for stably igniting the glow discharge in parallel.
are connected to each other. 1. Furthermore, in 1, a mixed gas containing, for example, CO2, N2, and He gas is used as the laser medium gas, and is sealed in the laser wind tunnel 1 at a pressure of about 30 to 100 Torr.

Further, the velocity of the gas flow 7 of the laser medium gas circulated within the discharge excitation section 2 is approximately several tens of m/s to several hundreds of m/s. During operation, a high voltage of several thousand volts or more is applied from the power supply 10 between the bottle-shaped cathode 5 and the anode 6 to generate a glow discharge 11, and the laser medium gas is excited by this discharge energy. At this time, the optical resonator 8a,
Laser oscillation occurs due to the action of 8b, and a laser output of 12 is generated in the 7 directions of the gas flow of the laser medium gas and in the direction perpendicular to the discharge direction.
is obtained.

(Problems to be Solved by the Invention) However, in the conventional laser device as described above, there were problems to be solved as described below. That is,
Laser oscillation is greatly affected by discharge conditions, gas conditions, cooling conditions, etc. For example, if the operating conditions of glow discharge are inappropriate, the laser gas will deteriorate due to discharge.
This results in unstable discharge and an increase in glow voltage, which in turn leads to the generation of arcs due to contraction of the glow discharge plasma.

Furthermore, if the circulating laser gas is insufficiently cooled, the temperature of the laser gas may rise, resulting in a decrease in laser output and, in turn, occurrence of arcing or oscillation stoppage. Furthermore, even if arcing does not occur, 02 is generated due to decomposition of the laser gas, resulting in a change in the glow discharge voltage (mainly a voltage increase) and a change in laser output due to fluctuations in the injected power. This is a major problem for high-output laser devices used for various processing purposes, and stabilization of laser output has been desired.

The present invention has been made to solve the above-mentioned problems, and its purpose is to provide a highly accurate control system for a laser device that can avoid unstable discharge and a decrease in output of the laser device. It is about providing.

[Structure of the Invention] (Means for Solving the Problems) A control system for a laser device according to the present invention connects a monitoring and measuring section that monitors and measures the operating state of the laser device, and controls the control system according to the output from the monitoring and measuring section. The present invention is characterized in that the arithmetic processing section outputs an optimal control function, and the operating state of the laser device is controlled based on this optimal control function.

(Function) According to the control system for a laser device of the present invention having the above configuration, the operating state of the discharge section is constantly monitored and measured.
Based on this monitoring data, the arithmetic processing unit outputs a performance function P, a reliability function S, and a cost function C, which are combined with an externally given interrupt function W to output an optimal control function, and the laser device is controlled based on this. Since the laser is operated, a highly reliable laser device with good overall efficiency can be obtained.

(Example) Hereinafter, an example of the present invention will be specifically described based on FIG.

In this embodiment, as shown in FIG.
1, based on information from various sensors (not shown) provided corresponding to predetermined monitoring items, the discharge state,
A monitoring and measuring section 22 is connected to monitor and measure the operating state of the laser device 21, such as the gas state or cooling state. Further, the output of this monitoring measurement section 22 is sent to the first conversion section 23, and after being subjected to signal processing such as impedance conversion,
The data is configured to be sent to the arithmetic processing section 24.

In this arithmetic processing section 24, the first conversion section 23
A performance function P, a reliability function S, or a cost function C is generated based on the signal, and an interrupt function W from the outside is added to this data for arithmetic processing. The control function processed and output by the arithmetic processing unit 24 is sent to the second converter 25, where it is subjected to signal processing such as impedance conversion, and then output to the control unit 26.

Then, in the control section 26, discharge conditions, gas conditions, cooling conditions, etc. are determined by the control function, and the laser device 21 is controlled based on them.

The laser device control system of this embodiment configured in this manner operates as described below. That is, the monitoring measurement section 22
, the discharge state fd (function giving the discharge state), gas state fg (gas state function), cooling state fc (cooling state function), and other fa (other state functions) of the laser device 21 are monitored and measured. , state function fd,
The state function shifted by 1 and outputted as 3, . 24(,! is sent. Then, this arithmetic processing unit 24-
tT is output as a performance function C or a reliability function S from the state quantities g, 3fd, fg, fe, and fa as follows.

1' = P (f d, f g, f c) ・
−= (1) C=C(f cl, f g, f
c) --(2) S = S (f 6. f g,
f c, f a) - (3) 1. There is a general formula 2'C for L, but specifically, for example, the performance function 11 is 1. , /-the value may be represented by the output of the meter itself at measurement j, 2. Also, Kono, To, Function C
The received power amount may be expressed as E, and the gas supply amount may be expressed as G (where, C=C]・E×C2φG (CI, C2 are conversion coefficients)...(l) in (4)). Furthermore, the reliability function S is, for example,
- discharge human power) 1'1], te, S; E 12+≦J
(1-≦E], b-, -,,,,, (5) (El, a;
Maximum allowable manpower, E, 1. b, Maximum allowable human power) Good luck, TeIj・EC is also good.

Further, the arithmetic processing section 2.1 generates these functions and outputs them as data to the section (7) and outputs them, for example, as a quality index and 1. , and the function FG is FG = T'/' C・・・・・・・・・・・・
...Defined in (6)5, if there is no interrupt function W, the reliability function S is tied to the selected allowable node (formula (5)), and the function FG is maximized. Optimal control function FCC
'J avoid occurrence. If there is an interrupt function W, the optimal control function FCC is created in the same way under the instructions of the interrupt function W.
is generated, and the j-st function is set as a control function that performs control such as maximizing the performance function I) within the range allowed by the state function S, even if it is large.

In this way, the arithmetic processing unit 24 generates! The optimal control function FCC, which has been converted to 1, is subjected to signal processing such as impedance conversion in the second conversion section 25, and is sent to the control section 26. Control part 2
6, according to this optimal control function FCC, L shown in FIG.
5, the discharge conditions, gas conditions, cooling conditions, etc. are determined, and based on the result W in A, the ray device 21 is controlled so that its operating state is optimal.

In this manner, according to this embodiment, the operating state of the L-noser device 21 can be maintained within the allowable values determined by the design conditions of the device itself, while achieving the lowest level of 21 seconds).・And-
), it is possible to obtain a highly reliable control system for laser equipment that has 11 functions of high efficiency, high performance, and long life, and can control its operation to achieve the best performance. can.

Note that the present invention is not limited to the embodiments described above, but can be applied to multiple units as shown in Figure 7.
This method can also be applied when using a thermal device.

That is, the plurality of laser devices 21a, 21b-212 are operated simultaneously, and these are monitored and measured by the monitoring and measuring units 22a, 22b...22z attached to each, and each state function, that is, the discharge state , a gas state, a cooling state, etc. are generated, and the first conversion unit 2
3a, 23F)... 23z performs signal processing such as impedance conversion, and after these signals are integrated by the integrating unit 3(), they are processed by the arithmetic processing unit 24. The process is basically shown in Figure 1,
As in the embodiment described above, there is C, but since the control section uses a plurality of laser devices, the performance function P generated by the arithmetic processing section,
Among the cost function C and the reliability function S, there are at least as many reliability functions S as the number of devices in one device (2, Sa, Sb・
...SZ is generated. This function Sa, Sb...Sz
Table 1-2 shows the surface of the multidimensional space composed of the voltage, current, pressure, gas flow rate, etc. of the laser device. It becomes inside the three-dimensional area. Therefore, the 11 optimal solutions are the edges or vertices of 7 bodies, and by making full use of the so-called linear programming method, the optimal solution can be obtained relatively easily.

Also, if the interrupt function W is entered, the interrupt function W
also represents a plane in the multidimensional space, so the solid body indicating the motion permissible region is cut by this plane.

That is, the motion permissible solid is divided by the plane W, and the permissible solid is divided into one side. Therefore, it can be seen that the method for obtaining the optimal solution is the same as described above. When the optimal solution is obtained in this way, the arithmetic processing unit 24 generates a control function, the division unit 31 divides the control function for each laser device, and the second conversion unit 25a, 25b...25z
Signal processing such as impedance conversion is performed by the control unit 26a.

26b...26z. In addition, each control unit 2
6a, 26b, etc. are configured to determine discharge conditions, gas conditions, cooling conditions, etc. according to each control function, and control each laser device 21a, 21b, etc. Therefore, since the entire plurality of laser devices can be effectively controlled, a highly reliable laser device control system with good overall efficiency can be obtained.

[Effects of the Invention] As described above, according to the present invention, a monitoring and measuring section for monitoring and measuring the operating state of the laser device is connected to the laser device, and the arithmetic processing section determines the optimal A highly accurate control system for a laser device is provided, which can avoid unstable discharge and output reduction of the laser device by outputting a control function and controlling the operating state of the laser device based on this optimal control function. can be provided.

[Brief explanation of drawings]

FIG. 1 is a functional block diagram showing one embodiment of a control system for a laser device according to the present invention, FIG. 2 is a functional block diagram showing another embodiment of the present invention, and FIG. FIG. 2 is a perspective view showing the main body structure of the laser device. DESCRIPTION OF SYMBOLS 1...Laser wind tunnel, 2...Discharge excitation part, 3...Cooling device, 4...Blower, 5...Pin-shaped cathode, 6...
・Anode, 7... Gas flow, 8a, 8b... Optical resonator, 9... Stabilizing impedance, 10... Power supply, 1
1...Glow discharge, 12...Laser output, 21...
-Laser device, 22...monitoring measurement section, 23...first
Conversion unit, 24... Arithmetic processing unit, 25... Second conversion unit, 26... Control unit, 30... Integration unit, 31...
Split part.

Claims (1)

[Claims] A monitoring and measuring unit that monitors and measures the operating state of the laser device is connected, and an optimum control function is output in an arithmetic processing unit according to the output from the monitoring and measuring unit, and the laser device operates based on this optimum control function. A control system for a laser device, characterized in that the operating state of the laser device is controlled.