Laser power stabilization device

Abstract

The present invention discloses a laser power stabilization device, which belongs to the field of laser processing technology. The device includes a fiber laser, a laser processing head, a laser power sampling module, a photoelectric conversion module, an optical power feedback control module, a data acquisition module, and a data processing module; the output end of the fiber laser is connected to the input end of the laser processing head; the output end of the laser processing head is connected to the input end of the laser power sampling module; the output end of the laser power sampling module is connected to the input end of the photoelectric conversion module; the output end of the photoelectric conversion module is connected to the input end of the optical power feedback control module; the output end of the optical power feedback control module is connected to the input end of the data acquisition module; the output end of the data acquisition module is connected to the input end of the data processing module; the output end of the data processing module is connected to the input end of the fiber laser; the present invention can greatly improve the stability of laser processing and ensure the process quality.

Description

Technical Field

[0001] The present invention relates to the technical field of laser processing, in particular to a laser power stabilizing device. Background Art

[0002] High-power fiber lasers are widely used in laser processing, particularly laser welding, a high-end welding technology characterized by high technology, high quality, high efficiency, and high precision. Its application in my country's industrial production is becoming increasingly widespread and popular. Laser welding is not only widely used in industrial production, but also in the welding of electronic products. When lasers are used in special applications such as precision machining, the stability of the laser power is crucial.

[0003] For high-power lasers, conventional cutting and welding speeds are below 10m / min, and the speed of surface modification is low. Under the premise that the laser power and mode can be guaranteed, the combination of high laser power and high cutting speed can achieve higher cutting efficiency and better cutting quality. This ultra-high-speed processing (cutting line speed > 50m / min) will be an inevitable trend in laser processing technology. However, a laser beam with macroscopically stable power will also have microscopic fluctuations in power under high time resolution sampling. This will not cause uneven processing quality during conventional speed processing, but the unevenness will be very obvious when used in ultra-high-speed laser processing. Therefore, we need the laser to have high power output and high power stability at the same time.

[0004] However, when a fiber laser is working, it is inevitable that its output power will change due to its own factors or changes in the external environment, such as aging of components in the laser optical system, attenuation of the pump source output power, changes in the heat dissipation of the laser, changes in the temperature and humidity of the external environment, and the amount of dust. These can easily cause the power of the laser output to fluctuate, which will directly lead to a decline in the quality of the processing technology. For example, during laser welding, fluctuations in laser power will cause changes in the front weld width, back weld width, back width ratio (the ratio of back width to front width), and weld surface burn. Changes in laser power will directly lead to changes in line energy and laser power density, thereby affecting the weld formation parameters through the thermal effect of temperature changes after the molten pool absorbs heat and the force effect after the keyhole appears. Summary of the Invention

[0005] The object of the present invention is to provide a laser power stabilization device to solve the problems raised in the above background technology.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a laser power stabilization device, characterized in that: the system includes a fiber laser, a laser processing head, a laser power sampling module, a photoelectric conversion module, an optical power feedback control module, a data acquisition module, and a data processing module;

[0007] The fiber laser is used to continuously output laser light;

[0008] The laser processing head is used to receive the laser and perform processing;

[0009] The laser power sampling module is used to sample the laser power when the laser processing head is working;

[0010] The photoelectric conversion module is used to convert the optical signal into an electrical signal and output the electrical signal;

[0011] The optical power feedback control module is used to receive and process the electrical signal to obtain a first actual power value;

[0012] The data acquisition module is used to collect the first actual power value, the aging degree of the laser power stabilization device, the operating temperature of the fiber laser, the temperature, humidity and dust content of the environment, and the attenuation rate during laser transmission to obtain an error power value;

[0013] The data processing module is used to obtain the collected information of the data collection module and process it to obtain the second actual power value required by the fiber laser when working;

[0014] In one embodiment, the laser processing head further comprises a laser output converter, a collimating cavity, and a focusing cavity; the laser output converter is used to bring the output laser light of the fiber laser into the laser processing head; the collimating cavity is used to collimate the divergent laser light transmitted by the laser output converter into parallel laser light; and the focusing cavity is used to focus the parallel light and output the focused laser light onto the processing surface. In one embodiment, the laser power sampling module further comprises an optical probe; a sampling point is provided at one end of the optical probe, and the sampling point is located on the laser transmission path and is used to sample the power of the parallel laser light.

[0015] In one embodiment, the photoelectric conversion module further includes a photodetector; the input end of the photodetector is connected to one end of the optical probe, and the output end is connected to the input end of the optical power feedback control module; the photodetector is used to convert the optical signal into an electrical signal, and the electrical signal is proportional to the power of the parallel laser.

[0016] In one embodiment, the optical power feedback control module includes an operational amplifier circuit, a hardware adjustment circuit, and a constant current power supply; the optical power feedback control module obtains an electrical signal from the photodetector and transmits the electrical signal to the operational amplifier circuit; after the electrical signal is amplified by the operational amplifier circuit, it is transmitted to the hardware adjustment circuit, and after being processed by the hardware adjustment circuit, it is transmitted to the constant current power supply; the constant current power supply is used to adjust the output current to obtain a first actual power value, recorded as p1, and send the first actual power value to the data acquisition module.

[0017] In one embodiment, the error power value is calculated as follows:

[0018] p0=a×h+b×t+c×m+d×s+e×v+f×g+L,

[0019] Among them, a, b, c, d, e, and f are the coefficient parameters of the linear regression model respectively, L is the compensation value of the linear regression model, h is the aging degree of the device, t is the operating temperature of the fiber laser, m is the temperature of the air environment, s is the humidity of the air environment, v is the amount of dust in the air environment, g is the attenuation rate during laser transmission, and p0 is the error power value.

[0020] In one embodiment, the data processing module further includes a data retrieval unit, a data analysis unit, a data storage unit and a timer; the data retrieval unit is used to retrieve the historical second actual power value of the data storage unit; the data analysis unit is used to analyze and process the obtained error power value and the first actual power value, and further obtain the second actual power value required for the operation of the fiber laser; the data storage unit is used to store the error power value, the first actual power value and the second actual power value; the timer is used to time the period from when the operator starts work to when the operator finishes work; the output end of the timer is connected to the input end of the data retrieval unit; the output end of the data retrieval unit is connected to the input end of the data analysis unit; the output end of the data analysis unit is connected to the input end of the data storage unit.

[0021] In one embodiment, the data analysis unit is further configured to obtain a calibration power value, denoted as p 校准 , the calibration power value p 校准 The steps to obtain are as follows:

[0022] Obtain the previous n error power values and the first actual power value with the current operation time as the node in the historical data. The previous n error power values are recorded as p 0i , the first actual power value of the first n times is recorded as p 1i , where i is the number of error power values and first actual power values;

[0023] According to the following formula, the calibration power value p is obtained 校准 :

[0024]

[0025] In one embodiment, the second actual power value is obtained by the following formula:

[0026] p=p0+p1+p 校准 ,

[0027] Among them, p is the second actual power value, p0 is the error power value, p1 is the first actual power value, p 校准 is the calibration power value;

[0028] In one embodiment, the laser power of the fiber laser is set, denoted as Q, and it is determined whether the second actual power value P falls within a threshold range [Q×G, Q / G], where G is the stability of the fiber laser;

[0029] If P falls within the threshold range, the fiber laser continues to operate according to the Q value;

[0030] If P does not fall within the threshold range, the fiber laser is operating abnormally, and the abnormal information is sent to the operator to adjust the parameters of the optical power feedback control module.

[0031] The beneficial effects achieved by the present invention are: the present invention can realize real-time monitoring of the output power of the laser when it is working. When the output power fluctuates, timely feedback is given on the circuit to adjust the laser power. At the same time, the influence of environmental changes and aging of internal components can also be taken into account, so that the stability of laser processing is greatly improved and the process quality is guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0033] Figure 1 1 is a schematic structural diagram of a laser power stabilization device according to an embodiment of the present invention;

[0034] Figure 2 1 is a schematic diagram of the working process of a laser power stabilization device according to an embodiment of the present invention;

[0035] Figure 3 This is a schematic structural diagram of a laser processing head of a laser power stabilization device according to an embodiment of the present invention;

[0036] In the figure: 1. Laser processing head, 2. Laser output converter, 3. Collimation cavity, 4. Focusing cavity, 5. Laser power sampling module, 6. Photoelectric conversion module, 7. Optical power feedback control module, 8. Data acquisition module, 9. Data processing module, 10. Fiber laser. DETAILED DESCRIPTION

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0038] See also Figure 1-Figure 3 In this embodiment, a laser power stabilization device is provided; the laser power stabilization system includes a fiber laser 10, a laser processing head 1, a laser power sampling module 5, a photoelectric conversion module 6, an optical power feedback control module 7, a data acquisition module 8, and a data processing module 9;

[0039] wherein the fiber laser 10 acts as a seed light source, and laser control is used to ensure that the laser of the fiber laser 10 continuously outputs, and the output laser is sent to the laser processing head 1; the laser processing head 1 is used to receive the laser from the fiber laser 10 and perform processing; a laser power sampling module 5 is used to sample the laser power of the laser processing head 1 when it is working; a photoelectric conversion module 6 is used to convert the optical signal into an electrical signal and send the electrical signal to the optical power feedback control module 7; the optical power feedback control module 7 is used to receive the electrical signal from the photoelectric conversion module 6 and perform processing to obtain a first actual power value; a data acquisition module 8 is used to collect the aging degree of the components in the laser power stabilization system, the operating temperature of the fiber laser 10, the temperature of the air environment, the humidity of the air environment, the amount of dust in the air environment, and the attenuation rate during the laser transmission process to obtain an error power value, and the data acquisition module 8 is also used to collect the first actual power value of the optical power feedback control module 7; a data processing module 9 is used to obtain the collected information of the data acquisition module 8 and process it to obtain the second actual power value required when the fiber laser 10 is working;

[0040] The output end of the fiber laser 10 is connected to the input end of the laser processing head 1; the output end of the laser processing head 1 is connected to the input end of the laser power sampling module 5; the output end of the laser power sampling module 5 is connected to the input end of the photoelectric conversion module 6; the output end of the photoelectric conversion module 6 is connected to the input end of the optical power feedback control module 7; the output end of the optical power feedback control module 7 is connected to the input end of the data acquisition module 8; the output end of the data acquisition module 8 is connected to the input end of the data processing module 9; and the output end of the data processing module 9 is connected to the input end of the fiber laser 10.

[0041] Furthermore, the laser processing head 1 further includes a laser output converter 2, a collimating cavity 3, and a focusing cavity 4. In this embodiment, the input end of the laser output converter 2 is connected to the output end of the fiber laser 10, the output end of the laser output converter 2 is connected to the input end of the collimating cavity 3, and the output end of the collimating cavity 3 is connected to the input end of the focusing cavity 4.

[0042] The laser output converter 2 is used to bring the output laser of the fiber laser 10 into the laser processing head 1; the collimating cavity 3 is used to collimate the divergent laser transmitted by the laser output converter 2 into parallel laser; the focusing cavity 4 is used to focus the parallel light, and the focused laser is output to the processing surface.

[0043] Furthermore, the laser power sampling module 5 also includes a sampling hole, and the sampling hole has a built-in optical probe; a sampling point is set at one end of the optical probe, and the sampling point is on the laser transmission path, which is used to sample the power of the parallel laser. In this embodiment, the sampling power is small enough not to affect the normal transmission of the laser; the other end of the optical probe is connected to the input end of the photoelectric conversion module 6; the laser power sampling module 5 is arranged in the collimating cavity 3.

[0044] Furthermore, the photoelectric conversion module 6 further includes a photodetector; the input end of the photodetector is connected to the other end of the optical probe, and the output end of the photodetector is connected to the input end of the optical power feedback control module 7;

[0045] In this embodiment, the photodetector is used to convert the optical signal into an electrical signal, and the electrical signal is proportional to the power of the parallel laser.

[0046] Furthermore, the optical power feedback control module 7 includes an operational amplifier circuit, a hardware adjustment circuit, and a constant current power supply; wherein the optical power feedback control module 7 obtains the electrical signal of the photodetector and transmits the electrical signal to the operational amplifier circuit; after the electrical signal is amplified by the operational amplifier circuit, it is transmitted to the hardware adjustment circuit, and after being processed by the hardware adjustment circuit, it is transmitted to the constant current power supply;

[0047] The constant current power supply is used to adjust the output current to obtain a first actual power value, which is recorded as p1, and send the first actual power value to the data acquisition module 8.

[0048] Furthermore, the data acquisition module 8 uses Matlab simulation software to analyze the collected data on the aging degree of the device, the operating temperature of the fiber laser 10, the temperature of the air environment, the humidity of the air environment, the amount of dust in the air environment, and the attenuation rate during laser transmission to obtain a linear regression model of the error power value and the aging degree of the device, the operating temperature of the fiber laser 10, the temperature of the air environment, the humidity of the air environment, the amount of dust in the air environment, and the attenuation rate during laser transmission, as follows:

[0049] p0=a×h+b×t+c×m+d×s+e×v+f×g+L,

[0050] Wherein, a, b, c, d, e, and f are coefficient parameters of the linear regression model, L is the compensation value of the linear regression model, h is the aging degree of the device, t is the operating temperature of the fiber laser 10, m is the temperature of the air environment, s is the humidity of the air environment, v is the amount of dust in the air environment, g is the attenuation rate during laser transmission, and p0 is the error power value;

[0051] In this embodiment, the aging degree of the device is evaluated and predicted based on the service life of the equipment and the number of maintenance and replacement times; the operating temperature of the fiber laser 10 and the temperature of the air environment are collected and obtained by temperature sensors; the amount of dust in the air environment is collected and obtained by dust sensors; and the attenuation rate during laser transmission is simulated and obtained by Matlab simulation software.

[0052] Furthermore, the data processing module 9 also includes a data retrieval unit, a data analysis unit, a data storage unit and a timer; the data retrieval unit is used to retrieve the historical second actual power value of the data storage unit; the data analysis unit is used to analyze and process the obtained error power value and the first actual power value, and further obtain the second actual power value required for the fiber laser 10 to work; the data storage unit is used to store the error power value, the first actual power value and the second actual power value; the timer is used to time the period from when the operator starts working to when the operator finishes working;

[0053] The output end of the timer is connected to the input end of the data retrieval unit; the output end of the data retrieval unit is connected to the input end of the data analysis unit; and the output end of the data analysis unit is connected to the input end of the data storage unit.

[0054] In this embodiment, the data analysis unit is further configured to obtain a calibration power value, denoted as p 校准 , the calibration power value p 校准The steps to obtain are as follows:

[0055] Obtain the previous n error power values and the first actual power value with the current operation time as the node in the historical data. The previous n error power values are recorded as p 0i , the first actual power value of the first n times is recorded as p 1i , where i is the number of error power values and first actual power values;

[0056] According to the following formula, the calibration power value p is obtained 校准 :

[0057]

[0058] Furthermore, the second actual power value is obtained by the following formula:

[0059] p=p0+p1+p 校准 ,

[0060] Among them, p is the second actual power value, p0 is the error power value, p1 is the first actual power value, p 校准 is the calibration power value;

[0061] In this embodiment, the first actual power value is obtained and adjusted through the optical power feedback control module 7. However, in practice, considering the influence of the external environment and the aging problem of the internal components of the equipment, it is necessary to use the error power value to compensate for the influence of the external environment and the aging problem of the internal components of the equipment. In addition, considering that the operating environment may change each time, it is necessary to further adjust the calibration power value based on the historical error power value and the historical first actual power value. Finally, the laser power of the fiber laser 10 is further obtained based on the first actual power value, the error power value and the calibration power value, which is the second actual power value.

[0062] Furthermore, the laser power of the fiber laser 10 is set, denoted as Q, and it is determined whether the second actual power value P falls within a threshold range [Q×G, Q / G], where G is the stability of the fiber laser 10;

[0063] If P falls within the threshold range, the fiber laser 10 continues to operate according to the Q value;

[0064] If P does not fall within the threshold range, the fiber laser 10 operates abnormally, and the abnormal information is sent to the operator to adjust the parameters of the optical power feedback control module 7.

[0065] In this embodiment:

[0066] The aging degree of the device, the operating temperature of the fiber laser 10, the temperature of the air environment, the humidity of the air environment, the amount of dust in the air environment, and the attenuation rate during laser transmission are obtained from the historical data. The linear regression model of the error power value and the aging degree of the device, the operating temperature of the fiber laser 10, the temperature of the air environment, the humidity of the air environment, the amount of dust in the air environment, and the attenuation rate during laser transmission is obtained through analysis using Matlab simulation software, as follows

[0067] p0=40×h+0.02×t+0.05×m+0.06×s+0.04×v+20×g+3;

[0068] The current device aging degree is 50%, the operating temperature of the fiber laser 10 is 40, the temperature of the air environment is 20, the humidity of the air environment is 30, the amount of dust in the air environment is 100, and the attenuation rate during laser transmission is 2%. P0 = 5.9 is obtained by substituting these into the linear regression model formula.

[0069] Obtaining an electrical signal from the photodetector, and processing the electrical signal through the optical power feedback control module 7 to obtain a first actual power value p1=80;

[0070] Get the error power value and the first actual power value of the five times before the current time node, and get p 01 =5, p 02 =6, p 03 =8, p 04 =4, p 05 =7, p 11 =60, p 12 =70, p 13 =90, p 14 =100, p 15 110, substitute into the formula:

[0071] Get: p 校准 =19.2;

[0072] According to the formula: p=p0+p1+p 校准 , input the data, and obtain the second actual power value required for the fiber laser 10 to work as 105.1;

[0073] The laser power of the fiber laser 10 is set to Q=105, G=99.5%, and the formula: [Q×G, Q / G] is substituted to obtain the threshold range [104.45, 105.5]. It is judged that 105.1∈[104.45, 105.5], and the fiber laser 10 continues to work according to the set power Q.

[0074] In addition, if the electrical signal of the photodetector is obtained, after the electrical signal is processed by the optical power feedback control module 7, the first actual power value p1=90 is obtained, and the formula p=p0+p1+p 校准 , we get p = 115.1, and The fiber laser 10 is operating abnormally, and the abnormal information is sent to the operator to adjust the parameters of the optical power feedback control module 7.

[0075] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0076] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A laser power stabilization device, characterized in that: include: Fiber laser, laser processing head, laser power sampling module, photoelectric conversion module, optical power feedback control module, data acquisition module and data processing module; The fiber laser is used to continuously output laser light; The laser processing head is used to receive the laser and perform processing; The laser power sampling module is used to sample the laser power when the laser processing head is working; The photoelectric conversion module is used to convert the optical signal into an electrical signal and output the electrical signal; The optical power feedback control module is used to receive the electrical signal and process it to obtain a first actual power value, which is recorded as ; The data acquisition module is used to collect the first actual power value, the aging degree of the laser power stabilization device, the operating temperature of the fiber laser, the temperature, humidity and dust content of the environment, and the attenuation rate during laser transmission to obtain an error power value. The error power value is calculated as follows: ； in, 、 、 、 、 、 are the coefficient parameters of the linear regression model, is the compensation value of the linear regression model, The aging degree of the device, is the operating temperature of the fiber laser, is the temperature of the air environment, The humidity of the air environment, The amount of dust in the air environment, is the attenuation rate during laser transmission, is the error power value; Furthermore, the data processing module is used to obtain the collected information of the data collection module and process it to obtain the second actual power value required by the fiber laser when it is working; The data processing module also includes a data retrieval unit, a data analysis unit, a data storage unit and a timer; The data analysis unit is used to analyze and process the obtained error power value and the first actual power value, and further obtain the second actual power value required for the fiber laser to work; The data analysis unit is also used to obtain a calibration power value, denoted as , the calibration power value The steps to obtain are as follows: Get the previous time in the historical data with the current job time as the node The error power value and the first actual power value, any one of the first n error power values is recorded as , any one of the first actual power values of the previous n times is recorded as ,in Representative serial number; According to the following formula, the calibration power value is obtained : ； The formula for obtaining the second actual power value is as follows: ； in, is the second actual power value, is the error power value, is the first actual power value, is the calibration power value; Set the laser power of the fiber laser to be , determine the second actual power value Whether it falls within the threshold range ,in is the stability of the fiber laser; like belongs to the threshold range, the fiber laser is The value continues to work; like If it does not fall within the threshold range, the fiber laser is operating abnormally, and the abnormal information is sent to the operator to adjust the parameters of the optical power feedback control module.

2. A laser power stabilization device according to claim 1, characterized in that: The laser processing head also includes a laser output converter, a collimating cavity and a focusing cavity; The laser output converter is used to bring the output laser of the fiber laser into the laser processing head; the collimating cavity is used to collimate the divergent laser transmitted by the laser output converter into parallel laser; the focusing cavity is used to focus the parallel light, and the focused laser is output to the processing surface.

3. A laser power stabilization device according to claim 2, characterized in that: The laser power sampling module further includes an optical probe; a sampling point is provided at one end of the optical probe, and the sampling point is on the laser transmission path, for sampling the power of the parallel laser.

4. A laser power stabilization device according to claim 3, characterized in that: The photoelectric conversion module also includes a photodetector; the input end of the photodetector is connected to one end of the optical probe, and the output end is connected to the input end of the optical power feedback control module; the photodetector is used to convert the optical signal into an electrical signal, and the electrical signal is proportional to the power of the parallel laser.

5. The laser power stabilization device according to claim 4, characterized in that: The optical power feedback control module includes an operational amplifier circuit, a hardware adjustment circuit, and a constant current power supply; the optical power feedback control module obtains the electrical signal of the photodetector and transmits the electrical signal to the operational amplifier circuit; the electrical signal is amplified by the operational amplifier circuit and transmitted to the hardware adjustment circuit, and then transmitted to the constant current power supply after being processed by the hardware adjustment circuit; the constant current power supply is used to adjust the output current to obtain a first actual power value, which is recorded as and sending the first actual power value to the data acquisition module.

6. The laser power stabilization device according to claim 1, characterized in that: The data retrieval unit is used to retrieve the historical error power value, the first actual power value and the second actual power value of the data storage unit; the data storage unit is used to store the error power value, the first actual power value and the second actual power value; the timer is used to time the period from when the operator starts work to when he finishes work; the output end of the timer is connected to the input end of the data retrieval unit; the output end of the data retrieval unit is connected to the input end of the data analysis unit; the output end of the data analysis unit is connected to the input end of the data storage unit.

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