A femtosecond laser processing system, method and device with temperature monitoring function

Abstract

The present invention relates to the field of laser processing technology, and proposes a femtosecond laser processing system, method and equipment with temperature monitoring function, including: obtaining a laser temperature sequence and a laser power sequence; obtaining a temperature anomaly index according to the laser temperature sequence; obtaining an overall correlation index and a local correlation index according to the laser temperature sequence and the laser power sequence, and obtaining a correlation matching degree according to the local correlation index and the overall correlation index; obtaining a temperature deviation according to the temperature anomaly index and the correlation matching degree, obtaining a laser temperature credibility according to the temperature deviation, screening laser temperature data that needs to be corrected according to the laser temperature credibility and correcting it to obtain a laser temperature correction sequence; monitoring the femtosecond laser processing process according to the laser temperature correction sequence. The present invention improves the accuracy of femtosecond laser processing by accurately monitoring the laser temperature.

Description

Technical Field

[0001] The present invention relates to the field of laser processing technology, and in particular to a femtosecond laser processing system, method and equipment with a temperature monitoring function. Background Art

[0002] Femtosecond laser processing system is a device that uses femtosecond pulse laser for high-precision processing. Its characteristics are ultra-short pulse duration, extremely high peak power, and the ability to achieve fine processing of materials with extremely small heat-affected zone. Femtosecond laser processing system is widely used in microelectronics, biomedicine, precision manufacturing and other fields for high-demand processes such as cutting, drilling, etching and surface modification.

[0003] During femtosecond laser processing, although femtosecond laser processing has the characteristic of a small heat-affected zone, local heating and rapid cooling of the material may cause microstructural changes or thermal stress. Real-time temperature monitoring can help optimize processing parameters, ensure processing quality, avoid thermal damage or unnecessary material deformation, and thus improve processing accuracy and stability.

[0004] When using temperature sensors to monitor the temperature of femtosecond laser processing, the high energy density of the femtosecond laser and the electromagnetic radiation it generates may interfere with the normal operation of the temperature sensor, resulting in inaccurate temperature data. Summary of the invention

[0005] The present invention provides a femtosecond laser processing system, method and equipment with temperature monitoring function to solve the problem that the high energy density of the existing femtosecond laser and the electromagnetic radiation it generates lead to inaccurate temperature measurement and affect the laser processing accuracy. The technical solution adopted is as follows:

[0006] The present invention proposes a femtosecond laser processing method with a temperature monitoring function, the method comprising the following steps:

[0007] Obtain the laser temperature sequence of several historical times and the current femtosecond laser processing and the laser power sequence of each femtosecond laser processing;

[0008] The temperature anomaly index at each moment of the current time is obtained according to the difference in the laser temperature sequence between the current time and several historical femtosecond laser processing times;

[0009] According to the correlation between the laser temperature sequence and the corresponding laser power sequence of several historical femtosecond laser processings, the overall correlation index between power and temperature is obtained; in the current femtosecond laser processing process, according to the correlation between the laser temperature sequence and the corresponding laser power sequence at the adjacent moments of each moment, the local correlation index between power and temperature at each moment is obtained, and according to the difference between the local correlation index between power and temperature at each moment and the overall correlation index, the correlation matching degree at each moment is obtained;

[0010] In the current femtosecond laser processing process, the temperature deviation at each moment is obtained according to the temperature anomaly index and the relevant matching degree at each moment, and the laser temperature credibility at each moment is obtained according to the difference between the temperature deviation at each moment and the adjacent moments. The laser temperature data that needs to be corrected is screened and corrected according to the laser temperature credibility to obtain the laser temperature correction sequence;

[0011] The femtosecond laser machining process is monitored according to the laser temperature correction sequence.

[0012] Furthermore, the temperature anomaly index at each moment of the current time is obtained according to the change difference of the laser temperature sequence of the current time and several historical femtosecond laser processing, including the specific method of:

[0013] The least square method is used to perform curve fitting on all laser temperature values ​​in the laser temperature sequence of any femtosecond laser processing, and the time series consisting of the fitted laser temperature values ​​corresponding to each moment is recorded as the fitted temperature sequence of the femtosecond laser processing;

[0014] Record any moment of the femtosecond laser processing as the target moment, and record the difference between the fitting temperature value at the target moment and the previous fitting temperature value in the fitting temperature sequence of the femtosecond laser processing as the temperature change index at the target moment;

[0015] The target time is the last time of the window, and the construction length is Window, record all the moments in the window as the neighborhood moments of the target moment;

[0016] The average of the temperature change indexes corresponding to all neighboring moments of the target moment is recorded as the temperature change rate at the target moment;

[0017] The K-means algorithm is used to cluster all the moments of the femtosecond laser processing. The cluster distance measurement uses the difference in the temperature change rate between every two moments to obtain three-stage clusters. The cluster with the largest mean of the temperature change rate at all moments in each cluster is recorded as the temperature rising cluster; the cluster with the smallest mean of the temperature change rate at all moments in each cluster is recorded as the temperature cooling cluster; the clusters other than the temperature rising cluster and the temperature cooling cluster are recorded as the temperature steady-state cluster.

[0018] For any moment of the current femtosecond laser processing, the average of the temperature change rates of all moments of the same cluster as the stage at this moment in several historical femtosecond laser processings is recorded as the reference temperature rate at this moment;

[0019] The current femtosecond laser processing The calculation method of the temperature anomaly index at a moment is: In the formula, This is the first time that femtosecond laser processing Temperature anomaly index at a certain moment; This is the first time that femtosecond laser processing Temperature change index at each moment; This is the first time that femtosecond laser processing The reference temperature rate at a given moment; is the absolute value function.

[0020] Furthermore, the overall correlation index between power and temperature is obtained based on the correlation between the laser temperature sequence and the corresponding laser power sequence of several historical femtosecond laser processings, including the specific method of:

[0021] The inversely proportional normalized result of the DTW distance between the laser temperature sequence and the laser power sequence of each femtosecond laser processing in the history is recorded as the relevant contribution index of each femtosecond laser processing in the history;

[0022] The average of the relevant contribution indexes of several historical femtosecond laser processings is recorded as the overall correlation index between power and temperature.

[0023] Furthermore, in the current femtosecond laser processing process, according to the correlation between the laser temperature sequence and the corresponding laser power sequence at the adjacent moments of each moment, a local correlation index of power and temperature at each moment is obtained, and according to the difference between the local correlation index of power and temperature at each moment and the overall correlation index, a correlation matching degree at each moment is obtained, including the specific method of:

[0024] For any moment in the current femtosecond laser processing process, the inverse normalized result of the DTW distance between the laser temperature sequence and the laser power sequence corresponding to the time interval formed by the neighboring time of the moment is recorded as the local correlation index of power and temperature at the moment;

[0025] The inverse proportional normalization result of the absolute value of the difference between the local correlation index of power and temperature at the moment and the overall correlation index is recorded as the correlation matching degree at the moment.

[0026] Furthermore, the temperature deviation at each moment is obtained according to the temperature anomaly index and the relevant matching degree at each moment. The specific acquisition method is: In the formula, For the Temperature deviation at a certain moment; For the Temperature anomaly index at a certain moment; For the The relevant matching degree at each moment; is the mean value of the correlation matching degree at all moments in the current femtosecond laser processing process; is a hyperparameter; is the absolute value function; is the sigmoid function.

[0027] Furthermore, the laser temperature credibility at each moment is obtained according to the difference in temperature deviation between each moment and the adjacent moments, including the specific method of:

[0028] For any moment in the current femtosecond laser processing process, the mean of the temperature deviations of all neighboring moments of this moment is recorded as the standard deviation of this moment;

[0029] The result of normalizing the inverse proportion of the absolute value of the difference between the temperature deviation at that moment and the standard deviation is recorded as the laser temperature reliability at that moment.

[0030] Furthermore, the laser temperature data that needs to be corrected is screened according to the laser temperature credibility and corrected to obtain a laser temperature correction sequence, including the specific method of:

[0031] In the current femtosecond laser processing process, the moment when the laser temperature credibility is lower than the preset credibility threshold is recorded as the moment to be corrected; for any moment to be corrected, the average of the laser temperature values ​​of all neighboring moments of the moment to be corrected is recorded as the corrected temperature value of the moment to be corrected; in the laser temperature sequence of the current femtosecond laser processing, the laser temperature value of each moment to be corrected is replaced by the corresponding corrected temperature value to obtain the laser temperature correction sequence of the current femtosecond laser processing.

[0032] Furthermore, the monitoring of the femtosecond laser processing process according to the laser temperature correction sequence includes the following specific methods:

[0033] Continuously appearing in the laser temperature correction sequence of the current femtosecond laser processing When an element with a temperature greater than the preset temperature threshold is detected, it indicates that the femtosecond laser processing has a temperature abnormality and adjusts the laser power; if the laser temperature correction sequence of the current femtosecond laser processing does not appear continuously The femtosecond laser processing process is continuously monitored if the temperature of the element is greater than the preset threshold value; is the preset continuous threshold.

[0034] The present invention also proposes a femtosecond laser processing system with a temperature monitoring function, which includes a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, the steps of the above method are implemented.

[0035] Another embodiment of the present invention provides a femtosecond laser processing device with a temperature monitoring function, including a femtosecond laser processing device body with a temperature monitoring function, and also includes a femtosecond laser processing system with a temperature monitoring function, wherein the femtosecond laser processing system with a temperature monitoring function includes a laser temperature power acquisition module, a temperature anomaly analysis module, a temperature power matching module, and a laser temperature monitoring module;

[0036] The laser temperature and power acquisition module is used to obtain the laser temperature sequence of several historical times and the current femtosecond laser processing and the laser power sequence of each femtosecond laser processing;

[0037] The temperature anomaly analysis module is used to obtain the temperature anomaly index at each moment of the current time according to the change difference of the laser temperature sequence of the current time and several historical femtosecond laser processing times;

[0038] The temperature power matching module is used to obtain the overall correlation index between power and temperature according to the correlation between the laser temperature sequence and the corresponding laser power sequence of several historical femtosecond laser processings; in the current femtosecond laser processing process, according to the correlation between the laser temperature sequence and the corresponding laser power sequence at the adjacent moments of each moment, obtain the local correlation index between power and temperature at each moment, and obtain the correlation matching degree at each moment according to the difference between the local correlation index between power and temperature at each moment and the overall correlation index; in the current femtosecond laser processing process, according to the temperature anomaly index and the correlation matching degree at each moment, obtain the temperature deviation at each moment, according to the difference between the temperature deviation at each moment and the adjacent moments, obtain the laser temperature credibility at each moment, and according to the laser temperature credibility, select the laser temperature data that needs to be corrected and correct it to obtain the laser temperature correction sequence;

[0039] The laser temperature monitoring module is used to monitor the femtosecond laser processing process according to the laser temperature correction sequence.

[0040] The beneficial effects of the present invention are as follows: in the process of femtosecond laser processing, for the problem of judging the abnormality of the laser temperature value in the laser temperature sequence, the present invention obtains the temperature abnormality index at each moment by the difference between the change of the laser temperature value at each moment of the current femtosecond laser processing and the change of the laser temperature value at several historical femtosecond laser processings, and makes a preliminary judgment on the abnormality of the laser temperature value; the judgment is made only according to the difference of the change of the laser temperature sequence at several historical times, without considering the change of the current laser power, because the processing environment, material characteristics or heat dissipation conditions and other factors may change in different femtosecond laser processing processes, thereby affecting the temperature change rate, which may cause inaccurate temperature monitoring results, the present invention combines the laser temperature sequence with the laser power sequence, judges the correlation between the laser temperature sequence and the laser power sequence, obtains the overall correlation index, and then obtains the local correlation index, and obtains the correlation matching degree according to the difference between the local correlation index and the overall correlation index; the laser temperature value disturbed by the high energy density of the femtosecond laser and the electromagnetic radiation generated by it needs to be corrected, the present invention obtains the temperature deviation by the temperature abnormality index and the correlation matching degree, screens and corrects the laser temperature value that needs to be corrected, and obtains the laser temperature correction sequence. Thus, the present invention monitors the laser temperature in the femtosecond laser processing process through the laser temperature correction sequence, thereby improving the accuracy of laser temperature monitoring and further improving the precision of femtosecond laser processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0042] Figure 1 A schematic flow chart of a femtosecond laser processing method with a temperature monitoring function provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work are within the scope of protection of the present invention.

[0044] See also Figure 1 , which shows a flow chart of a femtosecond laser processing method with temperature monitoring function provided by an embodiment of the present invention, the method comprising the following steps:

[0045] Step S001, obtaining laser temperature sequences of several historical femtosecond laser processings and the current femtosecond laser processing and laser power sequences of each femtosecond laser processing.

[0046] It should be noted that the purpose of this embodiment is to analyze the laser temperature data and laser power data, screen the temperature data disturbed by the high energy density of the femtosecond laser and the electromagnetic radiation it generates, and correct it to improve the accuracy of temperature monitoring. Therefore, the laser temperature data and laser power data are obtained.

[0047] It should be further explained that the fiber Bragg grating sensor can perform real-time temperature detection by monitoring the tiny strain and temperature changes of the optical fiber material, so the fiber Bragg grating sensor is used to measure the laser temperature.

[0048] Specifically, a fiber Bragg grating sensor is installed in the processing area near the laser action point; the relevant parameters of the femtosecond laser are set according to the requirements, the femtosecond laser is started, and the fiber Bragg grating sensor is used to The laser temperature value is collected once every second as a collection moment, and the time series consisting of the laser temperature values ​​collected at all moments of this femtosecond laser processing is recorded as the laser temperature sequence of this femtosecond laser processing;

[0049] The laser power value at each moment of this femtosecond laser processing is obtained, and the time series consisting of the laser power values ​​at all moments is recorded as the laser power sequence of this femtosecond laser processing.

[0050] According to the above-mentioned method for obtaining the laser temperature sequence and the laser power sequence, the most recent historical The laser temperature sequence of the femtosecond laser processing and the laser power sequence of each femtosecond laser processing; wherein, To preset the historical reference times, this embodiment uses Let's take this as an example.

[0051] Step S002: obtaining the temperature anomaly index at each moment of the current time according to the difference in the laser temperature sequence between the current time and several historical times of femtosecond laser processing.

[0052] It should be noted that during the femtosecond laser processing, the temperature change is rapid and nonlinear. Since the femtosecond laser pulse time is extremely short and the energy is concentrated, high temperature is generated instantly, and the local material heats up rapidly. However, since the pulse duration is very short, after the laser action ends, the heat diffuses rapidly and the temperature drops rapidly. During the entire processing process, the temperature usually goes through three stages: rapid rise, reaching a steady state, and then gradually cooling. The temperature change rates in these three stages are significantly different, so the three stages are distinguished according to the rate of temperature change.

[0053] Specifically, the least square method is used to perform curve fitting on all laser temperature values ​​in the laser temperature sequence of any femtosecond laser processing, and the time series consisting of the fitted laser temperature values ​​corresponding to each moment is recorded as the fitted temperature sequence of the femtosecond laser processing; wherein the least square method is a well-known technology, and the specific method is not introduced here;

[0054] Any moment of the femtosecond laser processing is recorded as the target moment, and the difference between the fitting temperature value at the target moment and the previous fitting temperature value in the fitting temperature sequence of the femtosecond laser processing is recorded as the temperature change index at the target moment. It is particularly noted that the temperature change index at the first moment is set to 0;

[0055] It should be noted that during the femtosecond laser processing, the laser temperature value obtained will be affected by the high energy density of the femtosecond laser and the electromagnetic radiation it generates, causing it to temporarily deviate from the normal value. In order to divide the three stages more accurately, the temperature change index is smoothed according to the temperature change index at adjacent moments.

[0056] Specifically, the target time is the last time of the window, and the construction length is , and record all the moments in the window as the neighboring moments of the target moment; To preset the neighborhood size, this embodiment uses As an example, it should be noted that if the time in the window is not enough If there are only moments in the window, only the moments in the window are taken as the neighboring moments of the target moment;

[0057] The average of the temperature change indexes corresponding to all neighboring moments of the target moment is recorded as the temperature change rate at the target moment;

[0058] use The K-means algorithm is used to cluster all the moments of the femtosecond laser processing. The cluster distance measurement adopts the difference of the temperature change rate between every two moments to obtain three-stage clusters; the cluster with the largest mean of the temperature change rate at all moments in each cluster is recorded as the temperature rising cluster; the cluster with the smallest mean of the temperature change rate at all moments in each cluster is recorded as the temperature cooling cluster; the clusters other than the temperature rising cluster and the temperature cooling cluster are recorded as the temperature steady-state cluster;

[0059] For any moment of the current femtosecond laser processing, the most recent The average of the temperature change rates at all times of the same cluster type as the stage at that moment in the sub-femtosecond laser processing is recorded as the reference temperature rate at that moment;

[0060] The current femtosecond laser processing The calculation method of the temperature anomaly index at a moment is: In the formula, This is the first time that femtosecond laser processing Temperature anomaly index at a certain moment; This is the first time that femtosecond laser processing Temperature change index at each moment; This is the first time that femtosecond laser processing The reference temperature rate at a given moment; is the absolute value function.

[0061] Step S003, according to the correlation between the laser temperature sequence and the corresponding laser power sequence of several historical femtosecond laser processings, the overall correlation index between power and temperature is obtained; in the current femtosecond laser processing process, according to the correlation between the laser temperature sequence and the corresponding laser power sequence at the adjacent moments of each moment, the local correlation index between power and temperature at each moment is obtained, and according to the difference between the local correlation index between power and temperature at each moment and the overall correlation index, the correlation matching degree at each moment is obtained.

[0062] It should be noted that the temperature anomaly index at each moment is preliminarily obtained based on the temperature change rate of the current femtosecond laser processing. However, if the judgment is made only based on the change differences of several historical laser temperature sequences without considering the change of the current laser power, the processing environment, material properties or heat dissipation conditions may change during different femtosecond laser processing processes, thereby affecting the temperature change rate, which may lead to inaccurate temperature monitoring results.

[0063] It should be further explained that when the laser power is high, the temperature rises faster; when the power is low, the temperature rises slower.

[0064] Specifically, the recent history The inversely proportional normalized result of the DTW distance between the laser temperature sequence and the laser power sequence of each femtosecond laser processing in the past is recorded as the relevant contribution index of each femtosecond laser processing in the past several times; wherein, the method for obtaining the DTW distance is a well-known technology, and the specific method is not introduced here;

[0065] The most recent history The average value of the relevant contribution index of sub-femtosecond laser processing is recorded as the overall correlation index of power and temperature.

[0066] It should be noted that when the laser power is high, the temperature rises faster, and when the power is low, the temperature rises slower. Regardless of the overall or local situation, the laser temperature and the laser power should satisfy this correlation. Therefore, according to the correlation between the laser temperature sequence and the corresponding laser power sequence at each adjacent moment, the local correlation index of power and temperature at each moment is obtained. According to the difference between the local correlation index of power and temperature at each moment and the overall correlation index, the correlation matching degree at each moment is obtained.

[0067] Specifically, for any moment in the current femtosecond laser processing process, the inverse proportional normalization result of the DTW distance between the two sequences corresponding to the time interval formed by the laser temperature sequence and the laser power sequence at the neighboring time of the moment is recorded as the local correlation index of the power and temperature at the moment; wherein, the method for obtaining the DTW distance is a well-known technology, and the specific method is not introduced here;

[0068] The inverse proportional normalization result of the absolute value of the difference between the local correlation index of power and temperature at the moment and the overall correlation index is recorded as the correlation matching degree at the moment.

[0069] Step S004: In the current femtosecond laser processing process, the temperature deviation at each moment is obtained according to the temperature anomaly index and the related matching degree at each moment, and the laser temperature credibility at each moment is obtained according to the difference between the temperature deviation at each moment and the adjacent moments. The laser temperature data that needs to be corrected is screened and corrected according to the laser temperature credibility to obtain the laser temperature correction sequence.

[0070] It should be noted that the deviation of the laser temperature data from the normal situation is obtained based on the difference in temperature changes between the current and several previous femtosecond laser processing processes, combined with the difference in the effect of laser power changes on temperature. If the temperature anomaly index of the current laser temperature change compared to the temperature change at the same stage in history is higher, and the difference between the correlation matching degree at the current moment and the overall correlation matching degree at all moments in the current femtosecond laser processing is greater, the deviation of the laser temperature data during the processing is greater.

[0071] Specifically, in the current femtosecond laser processing process, the The calculation method of temperature deviation at a moment is: In the formula, For the Temperature deviation at a certain moment; For the Temperature anomaly index at a certain moment; For the The relevant matching degree at each moment; is the mean value of the correlation matching degree at all moments in the current femtosecond laser processing process; To prevent the hyperparameter from having a denominator of 0, this embodiment uses to give a narrative; is the absolute value function; is a sigmoid function. This embodiment uses the sigmoid function to perform normalization processing.

[0072] It should be noted that the deviation of temperature reading from normal conditions may be due to the interference of the high energy density of the femtosecond laser and the electromagnetic radiation it generates. The temperature change is manifested as chaotic jumps in the temperature reading. It may also be due to problems in the actual processing process. The temperature change caused by the high energy density of the femtosecond laser and the interference of the electromagnetic radiation it generates is a short process, which is manifested as a high short-term temperature deviation. In order to prevent the unreal changes in the collected temperature from causing inaccurate temperature monitoring results, the laser temperature credibility at each moment is obtained based on the difference between the temperature deviation at each moment and its neighboring moments. The greater the difference between the temperature deviation at any moment in the current femtosecond laser processing process and its neighboring moments, the smaller the laser temperature credibility at that moment is, and the more correction is needed.

[0073] Specifically, for any moment in the current femtosecond laser processing process, the average of the temperature deviations of all neighboring moments of the moment is recorded as the standard deviation of the moment;

[0074] The result of normalizing the inverse proportion of the absolute value of the difference between the temperature deviation at that moment and the standard deviation is recorded as the laser temperature reliability at that moment.

[0075] It should be noted that the smaller the laser temperature credibility is, the more likely the laser temperature value corresponding to that moment is to be interfered by the high energy density of the femtosecond laser and the electromagnetic radiation it generates, and the more it needs to be corrected. Since the temperature change caused by the interference of the high energy density of the femtosecond laser and the electromagnetic radiation it generates is a short process, it can be corrected according to the laser temperature value at the neighboring moment.

[0076] Specifically, during the current femtosecond laser processing, the laser temperature reliability is lower than the preset reliability threshold. The moment to be corrected is recorded as the moment to be corrected; for any moment to be corrected, the average of the laser temperature values ​​of all neighboring moments of the moment to be corrected is recorded as the corrected temperature value of the moment to be corrected; in the laser temperature sequence of the current femtosecond laser processing, the laser temperature value of each moment to be corrected is replaced by the corresponding corrected temperature value to obtain the laser temperature correction sequence of the current femtosecond laser processing; this embodiment is based on Let's take this as an example.

[0077] Step S005: monitor the femtosecond laser processing process according to the laser temperature correction sequence.

[0078] It should be noted that the laser temperature correction sequence describes the actual temperature change of the laser in the current femtosecond laser processing. During the femtosecond laser processing, the femtosecond laser processing process needs to be monitored according to the laser temperature correction sequence.

[0079] Specifically, the laser temperature correction sequence of the current femtosecond laser processing appears continuously is greater than the preset temperature threshold When an element is present, it indicates that temperature abnormality has occurred in femtosecond laser processing and the laser power is adjusted; if the laser temperature correction sequence of the current femtosecond laser processing does not appear continuously is greater than the preset temperature threshold elements, and continue to monitor the femtosecond laser processing process; among them, To preset the continuous threshold, this embodiment uses , Let's take this as an example.

[0080] It should be noted that this embodiment adopts Model to present inverse proportional relationship and normalization, As the input of the model, the implementer can set the inverse proportional function and normalization function according to the actual situation.

[0081] Another embodiment of the present invention provides a femtosecond laser processing system with a temperature monitoring function, the system comprising a memory, a processor, and a computer program stored in the memory and running on the processor, and when the processor executes the computer program, the above method steps S001 to S005 are implemented.

[0082] Another embodiment of the present invention provides a femtosecond laser processing device with a temperature monitoring function, including a femtosecond laser processing device body with a temperature monitoring function, and also including a femtosecond laser processing system with a temperature monitoring function, wherein the femtosecond laser processing system with a temperature monitoring function includes a laser temperature power acquisition module, a temperature anomaly analysis module, a temperature power matching module, and a laser temperature monitoring module;

[0083] The laser temperature and power acquisition module is used to obtain the laser temperature sequence of several historical times and the current femtosecond laser processing and the laser power sequence of each femtosecond laser processing;

[0084] The temperature anomaly analysis module is used to obtain the temperature anomaly index at each moment of the current time according to the change difference of the laser temperature sequence of the current time and several historical femtosecond laser processing times;

[0085] The temperature power matching module is used to obtain the overall correlation index between power and temperature according to the correlation between the laser temperature sequence and the corresponding laser power sequence of several historical femtosecond laser processings; in the current femtosecond laser processing process, according to the correlation between the laser temperature sequence and the corresponding laser power sequence at the adjacent moments of each moment, obtain the local correlation index between power and temperature at each moment, and obtain the correlation matching degree at each moment according to the difference between the local correlation index between power and temperature at each moment and the overall correlation index; in the current femtosecond laser processing process, according to the temperature anomaly index and the correlation matching degree at each moment, obtain the temperature deviation at each moment, according to the difference between the temperature deviation at each moment and the adjacent moments, obtain the laser temperature credibility at each moment, and according to the laser temperature credibility, select the laser temperature data that needs to be corrected and correct it to obtain the laser temperature correction sequence;

[0086] The laser temperature monitoring module is used to monitor the femtosecond laser processing process according to the laser temperature correction sequence.

[0087] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A femtosecond laser processing method with temperature monitoring function, characterized in that: The method comprises the following steps: Obtain the laser temperature sequence of several historical times and the current femtosecond laser processing and the laser power sequence of each femtosecond laser processing; The temperature anomaly index at each moment of the current time is obtained according to the difference in the laser temperature sequence between the current time and several historical femtosecond laser processing times; According to the correlation between the laser temperature sequence and the corresponding laser power sequence of several historical femtosecond laser processings, the overall correlation index between power and temperature is obtained; in the current femtosecond laser processing process, according to the correlation between the laser temperature sequence and the corresponding laser power sequence at the adjacent moments of each moment, the local correlation index between power and temperature at each moment is obtained, and according to the difference between the local correlation index between power and temperature at each moment and the overall correlation index, the correlation matching degree at each moment is obtained; In the current femtosecond laser processing process, the temperature deviation at each moment is obtained according to the temperature anomaly index and the relevant matching degree at each moment, and the laser temperature credibility at each moment is obtained according to the difference between the temperature deviation at each moment and the adjacent moments. The laser temperature data that needs to be corrected is screened and corrected according to the laser temperature credibility to obtain the laser temperature correction sequence; The femtosecond laser machining process is monitored according to the laser temperature correction sequence.

2. A femtosecond laser processing method with temperature monitoring function according to claim 1, characterized in that: The specific method of obtaining the temperature anomaly index at each moment of the current time according to the change difference of the laser temperature sequence of the current time and several historical femtosecond laser processings includes: The least square method is used to perform curve fitting on all laser temperature values ​​in the laser temperature sequence of any femtosecond laser processing, and the time series consisting of the fitted laser temperature values ​​corresponding to each moment is recorded as the fitted temperature sequence of the femtosecond laser processing; Record any moment of the femtosecond laser processing as the target moment, and record the difference between the fitting temperature value at the target moment and the previous fitting temperature value in the fitting temperature sequence of the femtosecond laser processing as the temperature change index at the target moment; The target time is the last time of the window, and the construction length is Window, record all the moments in the window as the neighborhood moments of the target moment; The average of the temperature change indexes corresponding to all neighboring moments of the target moment is recorded as the temperature change rate at the target moment; The K-means algorithm is used to cluster all the moments of the femtosecond laser processing. The cluster distance measurement uses the difference in the temperature change rate between every two moments to obtain three-stage clusters. The cluster with the largest mean of the temperature change rate at all moments in each cluster is recorded as the temperature rising cluster; the cluster with the smallest mean of the temperature change rate at all moments in each cluster is recorded as the temperature cooling cluster; the clusters other than the temperature rising cluster and the temperature cooling cluster are recorded as the temperature steady-state cluster. For any moment of the current femtosecond laser processing, the average of the temperature change rates of all moments of the same cluster as the stage at this moment in several historical femtosecond laser processings is recorded as the reference temperature rate at this moment; The current femtosecond laser processing The calculation method of the temperature anomaly index at a moment is: In the formula, This is the first time that femtosecond laser processing Temperature anomaly index at a certain moment; This is the first time that femtosecond laser processing Temperature change index at each moment; This is the first time that femtosecond laser processing The reference temperature rate at a given moment; is the absolute value function.

3. The femtosecond laser processing method with temperature monitoring function according to claim 1, characterized in that: The overall correlation index between power and temperature is obtained based on the correlation between the laser temperature sequence and the corresponding laser power sequence of several historical femtosecond laser processings, including the specific method of: The inversely proportional normalized result of the DTW distance between the laser temperature sequence and the laser power sequence of each femtosecond laser processing in the history is recorded as the relevant contribution index of each femtosecond laser processing in the history; The average of the relevant contribution indexes of several historical femtosecond laser processings is recorded as the overall correlation index of power and temperature.

4. The femtosecond laser processing method with temperature monitoring function according to claim 2, characterized in that: In the current femtosecond laser processing process, according to the correlation between the laser temperature sequence and the corresponding laser power sequence at the adjacent moments of each moment, the local correlation index of power and temperature at each moment is obtained, and according to the difference between the local correlation index of power and temperature at each moment and the overall correlation index, the correlation matching degree at each moment is obtained, including the specific method of: For any moment in the current femtosecond laser processing process, the inverse normalized result of the DTW distance between the laser temperature sequence and the laser power sequence corresponding to the time interval formed by the neighboring time of the moment is recorded as the local correlation index of power and temperature at the moment; The inverse proportional normalization result of the absolute value of the difference between the local correlation index of power and temperature at the moment and the overall correlation index is recorded as the correlation matching degree at the moment.

5. The femtosecond laser processing method with temperature monitoring function according to claim 1, characterized in that: The temperature deviation at each moment is obtained according to the temperature anomaly index and the relevant matching degree at each moment. The specific acquisition method is as follows: In the formula, For the Temperature deviation at a certain moment; For the Temperature anomaly index at a certain moment; For the The relevant matching degree at each moment; is the mean value of the correlation matching degree at all moments in the current femtosecond laser processing process; is a hyperparameter; is the absolute value function; is the sigmoid function.

6. The femtosecond laser processing method with temperature monitoring function according to claim 2, characterized in that: The specific method of obtaining the laser temperature credibility at each moment according to the difference in temperature deviation between each moment and the adjacent moments is as follows: For any moment in the current femtosecond laser processing process, the mean of the temperature deviations of all neighboring moments of this moment is recorded as the standard deviation of this moment; The result of normalizing the inverse proportion of the absolute value of the difference between the temperature deviation at that moment and the standard deviation is recorded as the laser temperature reliability at that moment.

7. The femtosecond laser processing method with temperature monitoring function according to claim 2, characterized in that: The laser temperature data to be corrected is selected according to the laser temperature credibility and corrected to obtain the laser temperature correction sequence, including the specific method of: In the current femtosecond laser processing process, the moment when the laser temperature credibility is lower than the preset credibility threshold is recorded as the time to be corrected; for any time to be corrected, the average of the laser temperature values ​​of all neighboring moments of the time to be corrected is recorded as the corrected temperature value of the time to be corrected; In the laser temperature sequence of the current femtosecond laser processing, the laser temperature value at each time to be corrected is replaced by the corresponding correction temperature value to obtain the laser temperature correction sequence of the current femtosecond laser processing.

8. The femtosecond laser processing method with temperature monitoring function according to claim 1, characterized in that: The specific method of monitoring the femtosecond laser processing process according to the laser temperature correction sequence includes: Continuously appearing in the laser temperature correction sequence of the current femtosecond laser processing When an element with a temperature greater than the preset temperature threshold is detected, it indicates that the femtosecond laser processing has a temperature abnormality and adjusts the laser power; if the laser temperature correction sequence of the current femtosecond laser processing does not appear continuously The femtosecond laser processing process is continuously monitored if the temperature of the element is greater than the preset threshold value; is the preset continuous threshold.

9. A femtosecond laser processing system with a temperature monitoring function, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the steps of a femtosecond laser processing method with a temperature monitoring function as described in any one of claims 1 to 8 are implemented.

10. A femtosecond laser processing device with a temperature monitoring function, comprising a femtosecond laser processing device body with a temperature monitoring function, characterized in that: It also includes a femtosecond laser processing system with a temperature monitoring function, wherein the femtosecond laser processing system with a temperature monitoring function includes a laser temperature power acquisition module, a temperature anomaly analysis module, a temperature power matching module, and a laser temperature monitoring module; The laser temperature and power acquisition module is used to obtain the laser temperature sequence of several historical times and the current femtosecond laser processing and the laser power sequence of each femtosecond laser processing; The temperature anomaly analysis module is used to obtain the temperature anomaly index at each moment of the current time according to the change difference of the laser temperature sequence of the current time and several historical femtosecond laser processing times; The temperature power matching module is used to obtain the overall correlation index between power and temperature according to the correlation between the laser temperature sequence and the corresponding laser power sequence of several historical femtosecond laser processings; in the current femtosecond laser processing process, according to the correlation between the laser temperature sequence and the corresponding laser power sequence at the adjacent moments of each moment, obtain the local correlation index between power and temperature at each moment, and obtain the correlation matching degree at each moment according to the difference between the local correlation index between power and temperature at each moment and the overall correlation index; in the current femtosecond laser processing process, according to the temperature anomaly index and the correlation matching degree at each moment, obtain the temperature deviation at each moment, according to the difference between the temperature deviation at each moment and the adjacent moments, obtain the laser temperature credibility at each moment, and according to the laser temperature credibility, select the laser temperature data that needs to be corrected and correct it to obtain the laser temperature correction sequence; The laser temperature monitoring module is used to monitor the femtosecond laser processing process according to the laser temperature correction sequence.

Images