Calibration method of laser processing distance, computer storage medium and computer device

Abstract

The embodiment of the application discloses a laser processing distance calibration method, a computer storage medium and a computer device. The calibration method comprises the following steps: adjusting the distance between a cutting head and a metal plate to be processed to d, collecting the corresponding voltage V between the cutting head and the metal plate to be processed; obtaining the ratio K1 of (d i ‑d (i‑n1) ) / (V i ‑V (i‑n1) ) and the ratio K2 of (d (i+n2) ‑d i ) / (V (i+n2) ‑V i ), wherein i, n1, n2 and i-n1 are positive integers; establishing the voltage and distance relationship f(V, d) between the cutting head and the metal plate to be processed: when d (i‑n1) <d<=d i , d=K1*V; when d i <d<=d (i+n2) , d=K2*V.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of laser processing, and particularly relates to a laser processing distance calibration method, a computer storage medium and a computer device. BACKGROUND

[0002] In the laser processing process, the distance from the cutting head to the plate needs to be automatically controlled, and the cutting head is controlled to the required distance to ensure good processing effect. The commonly used method is to use a capacitive principle sensor, that is, a capacitive sensor. The cutting end of the cutting head is the anode, and the metal plate to be cut is the cathode, forming a capacitive sensing effect. According to the formula C = εS / 4πkd, the distance from the cutting head to the metal plate to be cut is obtained. The initial signal is a capacitive signal, but the capacitance value is very small, and direct use is easy to be disturbed. In actual use, the equipment manufacturer will generally pass through an analog circuit to convert the capacitive signal into a voltage signal. In this way, on the one hand, the problem of small capacitance value and easy disturbance can be solved, and on the other hand, after being converted into a voltage signal, it can better adapt to the use environment in the field, that is, it can be connected to any equipment manufacturer's analog module for use. In actual use, the initial voltage and distance relationship f0(v, d) between the laser cutting head and the metal plate to be processed is established by using the capacitive sensor calibration, and the distance from the cutting head to the metal plate to be cut is controlled by controlling the input voltage, so as to meet the actual use.

[0003] However, in the laser processing process, a large amount of laser energy is transmitted into the metal plate, causing the temperature of the metal plate to rise rapidly. At the same time, long-term processing also causes the overall ambient temperature to rise by 10-20℃, or even higher. With the rise in temperature of the metal plate, the cutting head, the capacitive sensor, and the environment, the value of ε / 4πk in the capacitive formula at this time is no longer the value at the temperature when the calibration is established. The value of ε / 4πk has changed, thereby changing the voltage-distance relationship. Therefore, when laser cutting, the distance value obtained by converting the voltage value is no longer accurate, thereby affecting the cutting height and the piercing height in the processing process, and ultimately leading to poor cutting effect.

[0004] At present, the common improvement method in the market is that when the laser processing reaches a certain setting time or a certain preset condition, the current processing task is manually or automatically interrupted, and a new voltage-distance relationship is re-established. Although this scheme can solve the above difficulties to a certain extent, the time required to re-establish the voltage-distance relationship is long, which will affect the processing efficiency. In addition, by setting the time or presetting the fixed condition, the real-time processing environment of the interface cannot be adapted, because the temperature is always changing during the process of stopping to establish a new voltage-distance relationship. After the new voltage-distance relationship is established, the temperature at the time of establishment is still different from the current temperature. Therefore, the distance value calculated according to the new voltage-distance relationship still has a large error, and it cannot always adapt to the needs of automatic production.

[0005] Therefore, how to improve the accuracy of the voltage-distance relationship in laser processing needs to be solved urgently. SUMMARY

[0006] The embodiment of the present application is a laser processing distance calibration method, computer storage medium and computer equipment, which can be used to automatically establish a new relationship f(V, d) between the voltage and the distance between the cutting head and the metal plate to be processed after triggering the calibration condition, so as to obtain a more accurate voltage-distance relationship in the new state and improve the accuracy of laser cutting.

[0007] The embodiment of the present application discloses a laser processing distance calibration method, which comprises:

[0008] The distance between the cutting head and the metal plate to be processed is adjusted to d, and the corresponding voltage V between the cutting head and the metal plate to be processed is collected. The ratio K1 of (di-d(i-n1)) / (Vi-V(i-n1)) and the ratio K2 of (d(i+n2)-di) / (V(i+n2)-Vi) are obtained, wherein i, n1, n2 and i-n1 are positive integers. The voltage and distance relationship f(V, d) between the cutting head and the metal plate to be processed is established: when d(i-n1)<d<=di, d=K1*V; when di<d<=d(i+n2), d=K2*V.

[0009] The application further discloses a laser processing distance calibration method, which comprises the following steps: establishing an initial relationship f0(V, d) between voltage and distance between a laser cutting head and a metal plate to be processed at a T0 temperature for initial laser processing; collecting the temperature T of the capacitive sensor, the light-on time t1 and the light-off time t2 of the cutting head in real time; determining whether the difference between T and T0 exceeds △T or whether the difference between T and Ta exceeds △T, wherein Ta is the temperature when the calibration is performed, a represents the number of times, for example, T1 is the temperature when the first calibration is performed, T2 is the temperature when the second calibration is performed, and so on, or whether the time difference between the current light-on time t1 of the cutting head and the previous light-off time t2 exceeds a preset threshold value △t; if yes, for the difference between T and T0 exceeding △T or the difference between T and Ta exceeding △T, after the current contour processing is completed according to the current voltage and distance relationship between the cutting head and the metal plate to be processed, the cutting head is moved to the metal plate to be processed at a distance d when the cutting head moves to the starting point of the next contour processing; and for the time difference between the current light-on time t1 of the cutting head and the previous light-off time t2 exceeding the preset threshold value △t, the cutting head is moved to the metal plate to be processed at a distance d at the light-on starting point; the cutting head is kept still for t milliseconds; the corresponding voltage V between the cutting head and the metal plate to be processed is collected; the ratio K1 of (di-d(i-n1)) / (Vi-V(i-n1)) and the ratio K2 of (d(i+n2)-di) / (V(i+n2)-Vi) are obtained, wherein i, n1, n2 and i-n1 are positive integers; it is determined whether K1 and K2 are located in the corresponding preset threshold value intervals; if yes, K1 and K2 are used as the coefficients of the voltage and distance relationship between the cutting head and the metal plate to be processed; if no, it is determined whether the coefficients K1 and / or K2 exceed the corresponding preset threshold value intervals but do not exceed the corresponding out-of-control intervals; if yes, the end value of the adjacent out-of-control interval is taken as the value of the corresponding coefficient, and a new relationship f(V, d) between the voltage and distance between the cutting head and the metal plate to be processed is established for subsequent laser processing; if no, neither of the coefficients K1 and K2 is used; it is determined whether the number of times that the continuously obtained coefficients K1 and / or K2 exceed the corresponding out-of-control intervals exceeds N times, wherein N is a positive integer; if yes, an automatic alarm is given and the current processing task is interrupted; if no, the current laser cutting head and the metal plate to be processed are used to complete the current contour processing according to the voltage and distance relationship therebetween, the cutting head is moved to the starting point of the next contour processing, and the effective coefficients K1 and K2 are continuously obtained until the new relationship f(V, d) between the voltage and distance between the cutting head and the metal plate to be processed is established for subsequent laser processing; when di-d(i-n1)

[0010] The application further discloses a computer storage medium, which stores a computer program. The computer program is executed by a processor to enable the processor to execute the calibration method.

[0011] The application further discloses a computer device, which comprises a memory and a processor. The memory stores a computer program. The computer program is executed by the processor to enable the processor to execute the calibration method.

[0012] The application can collect different (v, d) data under current processing conditions to establish a more accurate voltage-distance relationship between the cutting head and the metal plate to be processed under the current processing conditions. Whether the voltage-distance relationship is executed can be determined according to the actual processing conditions. In actual use, the voltage-distance relationship under the new condition can be automatically established by presetting the condition to trigger the cutting head and the metal plate to be processed, so that the corresponding high-precision voltage-distance relationship can be used under different conditions to calibrate the laser processing distance, thereby overcoming the problem that the actual required laser processing distance deviates greatly from the calculated laser processing distance due to the change of the processing environment and other conditions, and the voltage-distance relationship between the cutting head and the metal plate to be processed is always changing. The accuracy of the voltage-distance relationship in laser processing is improved, and the accuracy of laser cutting is improved. BRIEF DESCRIPTION OF DRAWINGS

[0013] The accompanying drawings included to provide a further understanding of the application and constitute a part of the specification, illustrate embodiments of the application and together with the text description serve to explain the principles of the application. Obviously, the drawings in the following description are only some embodiments of the application, and those skilled in the art can obtain other drawings according to these drawings without creative labor. In the drawings:

[0014] Figure 1 is a flowchart of a laser processing distance calibration method disclosed by the application;

[0015] Figure 2 is a flowchart of the step Sa after being detailed and expanded on the basis of Figure 1

[0016] Figure 3 is a flowchart for establishing a new voltage-distance relationship between the cutting head and the metal plate to be processed, with the temperature T0 of the capacitance sensor when the initial voltage-distance relationship f0(V, d) is established as the reference condition;

[0017] Figure 4 is​Figure 3 The flow chart after step S30 is detailed and expanded on this basis;

[0018] Figure 5 The flow chart is used to establish a new relationship between voltage and distance between the cutting head and the metal plate to be processed, with the temperature Ta after a calibration as a reference condition;

[0019] Figure 6 The flow chart after step S31 is detailed and expanded on this basis; Figure 5

[0020] Figure 7 The flow chart is used to establish a new relationship between voltage and distance between the cutting head and the metal plate to be processed, with the time difference between the light-on time t1 and the adjacent light-off time t2 being greater than the preset threshold value Δt as a reference condition;

[0021] Figure 8 The flow chart after step S34 is detailed and expanded on this basis; Figure 7

[0022] Figure 9 The flow chart is a detailed flow chart of steps Sb to Sd;

[0023] Figure 10 The flow chart is a complete calibration method of the laser processing distance disclosed by the embodiments of the present application;

[0024] Figure 11 The relationship between voltage and distance between the actual cutting head and the metal plate to be processed without calibration of the laser processing distance is compared with the ideal relationship in the schematic diagram;

[0025] Figure 12 The relationship between voltage and distance between the actual cutting head and the metal plate to be processed after calibration of the laser processing distance is compared with the ideal relationship in the schematic diagram. DETAILED DESCRIPTION

[0026] It should be understood that the terms used herein are merely for the purpose of describing specific embodiments and are representative, but the present application can be embodied in many alternative forms, and should not be interpreted as being limited to the embodiments set forth herein.

[0027] In the description of the present application, the term "comprising" and any variation thereof means non-exclusive inclusion, and one or more other features, integers, steps, operations, units, components and / or combinations thereof can exist or be added. The specific meaning of the above-mentioned term in the present application can be understood by the person skilled in the art according to the specific circumstances.

[0028] The present application will be described in detail below with reference to the accompanying drawings and optional embodiments. ​​

[0029] As Figure 1 and Figure 12 The embodiment of the present application discloses a laser processing distance calibration method, comprising the steps of:

[0030] Sa, adjust the distance between the cutting head and the metal plate to be processed to d, and collect the corresponding voltage V between the cutting head and the metal plate to be processed;

[0031] Sb, obtain the ratio K1 of (di-d(i-n1)) / (Vi-V(i-n1)) and the ratio K2 of (d(i+n2)-di) / (V(i+n2)-Vi), wherein i, n1, n2 and i-n1 are positive integers; and

[0032] Sd, establish the voltage and distance relationship f(V, d) between the cutting head and the metal plate to be processed: when d(i-n1)<d<=di, d=K1*V; when di<d<=d(i+n2), d=K2*V.

[0033] The embodiment of the present application collects different (v, d) data under the current processing condition to establish a more accurate voltage and distance relationship between the cutting head and the metal plate to be processed suitable for the current processing condition, which can be determined according to the actual processing conditions affecting the voltage and distance relationship. For example, in the process of laser processing, as the processing proceeds, the temperature of the capacitive sensor continuously rises, which changes the voltage-distance relationship. In order to ensure that the voltage-distance relationship used in subsequent processing is more accurate and suitable for the new temperature environment, the temperature can be used as a trigger condition, that is, when the temperature changes more than a certain value, the numerical control machine tool automatically establishes a new voltage and distance relationship between the cutting head and the metal plate to be processed, that is, a new voltage and distance relationship f(V, d) between the cutting head and the metal plate to be processed is established according to steps Sa, Sb and Sc, and is used for subsequent processing. Of course, if a more accurate voltage and distance relationship is required, the embodiment of the present application can also establish a corresponding new voltage and distance relationship for the current contour processing before each contour processing.

[0034] Step Sa is to collect the different distances d between the cutting head and the metal plate to be processed and the corresponding voltages V of the capacitive sensor under the condition that the trigger condition is met, that is, (di, Vi), (d(i-n1), V(i-n1)) and (d(i+n2), V(i+n2)) and other data, and then under the new condition, when d(i-n1)<d<=di, the voltage and distance relationship between the cutting head and the metal plate to be processed is established by K1; when di<d<=d(i+n2), the voltage and distance relationship between the cutting head and the metal plate to be processed is established by K2. Of course, the distance between the cutting head and the metal plate to be processed can be any value, as long as the mechanical mechanism meets the requirements, but the perception of the capacitive sensor has a range, so the distance between the cutting head and the metal plate to be processed in the embodiment of the application is within a certain range, that is, 0<d<=H, where H is the maximum perceivable distance between the cutting head and the metal plate to be processed during the processing of the metal plate to be processed.

[0035] In actual use, the preset temperature and / or time and other conditions can be used to trigger the automatic establishment of the voltage and distance relationship between the cutting head and the metal plate to be processed under the new condition, so that the corresponding high-precision voltage-distance relationship can be used to calibrate the laser processing distance under different conditions. The entire calibration process can be automatically executed by the numerical control machine tool and the execution time is in milliseconds. The change in processing conditions in this process can be ignored, while the existing technical means of interrupting the processing task and re-establishing a new voltage-distance relationship requires tens of seconds. The application can save tens to hundreds of times of time compared with the prior art, and the new voltage-distance relationship established by the application can be more accurately applicable to the current processing. Further, the problem of large deviation between the actual required laser processing distance and the calculated laser processing distance caused by the change of the voltage-distance relationship between the cutting head and the metal plate to be processed due to changes in processing environment and other conditions is overcome. The accuracy of the voltage-distance relationship in laser processing is improved, thereby improving the accuracy of laser cutting.

[0036] As shown in Figure 2 , wherein the Sa step includes the following sub-steps:

[0037] Sa1, moving the cutting head to a distance d from the metal plate to be processed;

[0038] Sa2, the cutting head is stationary for t milliseconds; and

[0039] Sa3, collecting the voltage V between the cutting head and the metal plate to be processed.

[0040] The embodiment of the application adjusts the distance d between the cutting head and the metal plate to be processed by controlling the movement of the cutting head through the control system. The existing numerical control machine tool can

[0041] The cutting head is moved to a position and then is kept still for t milliseconds, so that the error caused by the shaking of the cutting head is eliminated, and the precision of the cutting head in the subsequent machining is improved. Then, the voltage V fed back when the distance d between the cutting head and the metal plate to be machined under the current state is recorded, and the (v, d) data set is obtained.

[0042] As shown in Figure 3 Further, the calibration method can further include the following steps:

[0043] S10, establishing an initial relationship f0(V, d) between the voltage and the distance between the cutting head and the metal plate to be machined at the temperature T0 of the capacitive sensor for initial laser machining;

[0044] S20, collecting the temperature T of the capacitive sensor in real time; and

[0045] S30, if T-T0>△T, establishing a new relationship f(V, d) between the voltage and the distance between the cutting head and the metal plate to be machined and used for subsequent laser machining.

[0046] Before the laser machining is performed, the initial relationship f0(V, d) between the voltage and the distance is established according to the machining environment before the laser machining for the initial stage of the laser machining, that is, the steps S10, S20 and S30 are sequentially performed before the step Sa1. The temperature T of the capacitive sensor is collected in real time by the numerical control machine during the laser machining, and the temperature of the machining environment can also be collected, but the temperature T of the capacitive sensor is mainly used as the reference. Then, it is determined in real time whether the difference T-T0 is greater than the preset temperature difference△T. The parameter△T is obtained according to the actual laser machining experience, that is, if T-T0>△T, the initial relationship f0(V, d) between the voltage and the distance is no longer accurate for the current machining, and a new relationship f(V, d) between the voltage and the distance between the cutting head and the metal plate to be machined needs to be established and used for the subsequent laser machining, that is, the steps Sa1, Sa2, Sa3, Sb and Sd are sequentially performed. If T-T0<=△T, the initial relationship f0(V, d) between the voltage and the distance is still accurate for the current machining.

[0047] As shown in Figure 4 The step S30 includes the following sub-steps:

[0048] S301, if T-T0>△T and the calibration has not been performed, the new relationship f(V, d) between the voltage and the distance between the cutting head and the metal plate to be machined is established when the cutting head moves to the starting point of the next contour machining after the current contour machining is completed, and is used for the current laser machining.

[0049] In the stage that the temperature of the capacitive sensor is first increased from T0 to T (T-T0=△T), f0(V, d) is always used for the current profile processing. When T-T0 is first greater than △T, if the cutting head is in the working state at this time, f0(V, d) is still used to complete the current profile processing, and then the cutting head moves to the starting point of the next profile processing, steps Sa1, Sa2, Sa3, Sb and Sd are executed to establish a new relationship f(V, d) between the cutting head and the metal plate to be processed and used for the laser processing of the next profile.

[0050] Of course, the embodiment of the present application can also immediately stop the current cutting head processing when T-T0 is first greater than △T, and immediately establish a new relationship f(V, d) between the cutting head and the metal plate to be processed and used for the subsequent processing of the next profile.

[0051] As shown in the figure, further, the calibration method can further include the steps of: Figure 5

[0052] S31, if T-Ta>△T, a new relationship f(V, d) between the cutting head and the metal plate to be processed is established and used for subsequent laser processing, wherein the temperature when the calibration is performed is Ta, and a represents the number of times, such as the temperature when the first calibration is T1, the temperature when the second calibration is T2, and so on.

[0053] The △T in step S31 can be equal to the △T in steps S30 and S301, or can not be equal. In the embodiment of the present application, the two △T are equal, that is, when the temperature of the capacitive sensor changes by △T, the current voltage and distance relationship is no longer accurate for the laser processing at the current temperature, and a new relationship f(V, d) between the cutting head and the metal plate to be processed needs to be established and used for subsequent laser processing. Therefore, the voltage and distance relationship f0(V, d) is applicable in the interval from T0 to T1, the voltage and distance relationship f1(V, d) is applicable in the interval from T1 to T2, the voltage and distance relationship f2(V, d) is applicable in the interval from T2 to T3, and so on.

[0054] As shown in the figure, wherein the S31 step includes the sub-steps of: Figure 6

[0055] S311, if T-Ta>△T after a has been executed for a number of times, a new relationship f(V, d) between the cutting head and the metal plate to be processed is established and used for the laser processing at the current profile after the current profile processing is completed, wherein a is a positive integer.

[0056] ​​If the calibration has been performed a times, i.e. Ta<T<=T(a+1), the fa(V, d) is used for the current contour processing, and if the temperature T-Ta>△T of the real-time collected capacitance sensor, the fa(V, d) is used for the current contour processing, and after the cutting head moves to the next contour processing starting point, a new relationship fa+1(V, d) between the cutting head and the metal plate to be processed is established and used for the laser processing in the stage of T(a+1)<T<=T(a+2) or T(a+1)<T.

[0057] Of course, the current cutting head processing can be stopped immediately when T-Ta is greater than △T, and a new relationship fa+1(V, d) between the cutting head and the metal plate to be processed is established immediately and used for the subsequent contour processing.

[0058] As shown in Figure 7 It can be understood that the calibration method can further include the steps of:

[0059] S32, collecting the light-on time t1 and the light-off time t2 of the cutting head;

[0060] S33, judging whether the time difference between the current light-on time t1 and the previous light-off time t2 is greater than a preset threshold △t; and

[0061] S34, yes, a new relationship f(V, d) between the cutting head and the metal plate to be processed is established and used for the subsequent laser processing.

[0062] The calibration method of the embodiment of the application collects the light-on time t1 and the light-off time t2 of the cutting head each time, and then takes the time difference between the light-on time t1 and the adjacent light-off time t2 as a judgment condition, and the threshold △t is an empirical value obtained by actual laser processing. When the time difference between the current light-on time t1 and the previous light-off time t2 is greater than the threshold △t, i.e. t2-t1>△t, the current light-on time and the previous light-off time are different for a long time, i.e. the laser light-off is for a long time, which can cause a large temperature difference, and further cause the relationship between the current cutting head and the metal plate to be processed to be unable to accurately apply to the subsequent processing. Therefore, a new relationship f(V, d) between the cutting head and the metal plate to be processed is established and used for the subsequent laser processing.

[0063] The execution of steps S32, S33 and S34 can be simultaneous with the execution of steps S20 and S30.

[0064] Of course, if the time difference between the current light-on time t1 and the previous light-off time t2 is less than or equal to the preset threshold △t, the current relationship between the cutting head and the metal plate to be processed is continued to be used for processing.

[0065] As shown in Figure 8 , wherein the S34 step comprises sub-steps:

[0066] S341, Yes, the cutting head is at the current open light point position, a new relationship f(V, d) between the voltage and distance between the cutting head and the metal plate to be processed is established and used for the current laser processing.

[0067] When the time difference between the current open light time t1 and the last light-off time t2 is greater than the preset threshold value Δt, a new relationship f(V, d) between the voltage and distance between the cutting head and the metal plate to be processed is established before the light processing, and then used for the current laser processing. In the embodiment of the application, the current open light point position of the cutting head is the starting point of the open light processing. If the condition that the time difference between the current open light time t1 and the last light-off time t2 is greater than the preset threshold value Δt is met, the position of the current open light processing is the position of establishing the new relationship between the voltage and distance between the cutting head and the metal plate to be processed. The position can be the starting point of the current contour, or the starting point of the current contour for further processing after the partial processing is completed. As shown in Figure 9 , it can also be understood that the calibration method can further include a step executed between step Sb and step Sd:

[0068] Sc1, judge whether K1 and K2 are located in the corresponding preset threshold value interval respectively;

[0069] Sc2, Yes, use K1 and K2 as the coefficients of the voltage and distance relationship f(V, d) between the cutting head and the metal plate to be processed;

[0070] Sc3, No, judge whether the coefficients K1 and / or K2 exceed the corresponding preset threshold value interval but do not exceed the corresponding out-of-control interval;

[0071] Sc4, Yes, take the end value of the adjacent out-of-control interval as the value of the corresponding coefficient;

[0072] Sc5, No, the coefficients K1 and K2 are not used this time, and the current K1 and K2 are continued to be used;

[0073] Sc6, judge whether the number of times that the continuously acquired coefficients K1 and / or K2 exceed the corresponding out-of-control interval exceeds N times, wherein N is a positive integer;

[0074] Sc7, Yes, automatically alarm and interrupt the current processing task; and

[0075] Sc8, no, then the current laser cutting head and the distance between the relationship between the voltage and the metal plate to be processed is completed by the current profile processing, to the next profile processing starting point, continue to obtain until the determination of the effective coefficient K1 and K2.

[0076] The application embodiment is used to determine whether K1 and K2 obtained in step Sb meet the use condition, and the condition of whether to directly use K1 and K2 is determined by judging whether K1 and K2 are located in the corresponding preset threshold interval, wherein K1 and K2 can correspond to the same threshold interval, or can separately correspond to different threshold intervals, and the application embodiment takes K1 and K2 corresponding to the same threshold interval as an example. When K1 and K2 are located in the threshold interval, K1 and K2 are directly applied to establish the voltage and distance relationship between the cutting head and the metal plate to be processed.

[0077] When at least one of K1 and K2 exceeds the threshold interval, K1 and K2 cannot be directly applied to establish the voltage and distance relationship between the cutting head and the metal plate to be processed, but the judgment of whether K1 and / or K2 exceed the preset threshold interval is continued, but not the out-of-control interval. The out-of-control interval is used as a reference to determine whether K1 and K2 have value. The application embodiment takes K1 and K2 corresponding to the same out-of-control interval as an example. When at least one of K1 and K2 exceeds the threshold interval, but neither of them exceeds the out-of-control interval, K1 takes the end value of the out-of-control interval close to the value of K1, K2 takes the end value of the out-of-control interval close to the value of K2, and then is applied to establish the voltage and distance relationship between the cutting head and the metal plate to be processed.

[0078] When at least one of K1 and K2 exceeds the out-of-control interval, the distance d between the cutting head and the metal plate to be processed, the corresponding voltage V, K1 and K2 collected this time are all invalid, indicating that the (d, V) collected this time is abnormal, resulting in invalid calculation values, or the voltage and distance relationship between the cutting head and the metal plate to be processed established by using the calculated K1 and K2 deviates from the voltage and distance relationship in the last state too much, which is obviously inaccurate. The distance d between the cutting head and the metal plate to be processed and the corresponding voltage V collected by the application embodiment are completed at the starting point of one profile processing. If the finally obtained K1 and K2 are determined to be invalid, the voltage and distance relationship between the cutting head and the metal plate to be processed established by the last obtained K1 and K2 is used for the corresponding profile processing, and the distance d between the cutting head and the metal plate to be processed and the corresponding voltage V are collected at the starting point of the next profile for obtaining K1 and K2.

[0079] When the continuously acquired coefficients K1 and / or K2 exceed the out-of-control interval for more than N times, where N is a positive integer, it indicates that the current data acquisition may have a fault, etc., and the numerical control machine tool automatically alarms and interrupts the current processing task so as to intervene by personnel. If the continuously acquired coefficients K1 and / or K2 exceed the out-of-control interval for less than N times, the current contour processing is completed by using the voltage and distance relationship between the laser cutting head and the metal plate to be processed, and at the starting point of the next contour processing, the valid coefficients K1 and K2 are continuously acquired.

[0080] As shown in the specific embodiment, the calibration method comprises the following detailed steps: Figure 10

[0081] S1, establishing the initial relationship f0(V, d) between the voltage and distance between the laser cutting head and the metal plate to be processed at the temperature T0 of the capacitive sensor for initial laser processing;

[0082] S2, acquiring the temperature T of the capacitive sensor, the light-on time t1 of the cutting head and the light-off time t2 in real time;

[0083] S3, judging whether the difference T-T0 of the temperature that has not been calibrated is greater than △T, or the difference T-Ta of the temperature that has been calibrated a times is greater than △T, where Ta is the temperature at which the calibration is performed, a represents the number of times, T1 is the temperature at which the first calibration is performed, T2 is the temperature at which the second calibration is performed, and so on, or whether the time difference between the current light-on time t1 of the cutting head and the previous light-off time t2 is greater than the preset threshold value △t;

[0084] S4, yes, for the difference T-T0 of the temperature that has not been calibrated is greater than △T or the difference T-Ta of the temperature that has been calibrated a times is greater than △T, after the current contour processing is completed by using the voltage and distance relationship between the cutting head and the metal plate to be processed, the cutting head is moved to the metal plate to be processed at a distance d at the starting point of the next contour processing; and for the time difference between the current light-on time t1 of the cutting head and the previous light-off time t2 is greater than the preset threshold value △t, the cutting head is moved to the metal plate to be processed at a distance d at the light-on starting point;

[0085] S5, the cutting head is stationary for t milliseconds;

[0086] S6, the corresponding voltage V between the cutting head and the metal plate to be processed is acquired;

[0087] S7, the ratio K1 of (di-d(i-n1)) / (Vi-V(i-n1)) and the ratio K2 of (d(i+n2)-di) / (V(i+n2)-Vi) are acquired, where i, n1, n2 and i-n1 are positive integers; ​

[0088] S8, judging whether K1 and K2 are respectively located in corresponding preset threshold intervals;

[0089] S9, yes, then adopting K1 and K2 as the coefficients of the voltage and distance relationship between the cutting head and the metal plate to be processed;

[0090] S10, no, then judging whether the coefficients K1 and / or K2 are out of the corresponding preset threshold intervals but not out of the corresponding out-of-control intervals;

[0091] S101, yes, then taking the end value of the adjacent out-of-control interval as the value of the corresponding coefficient, and establishing a new voltage and distance relationship f(V, d) between the cutting head and the metal plate to be processed for subsequent laser processing;

[0092] S102, no, then neither of the coefficients K1 and K2 is adopted this time;

[0093] S103, judging whether the number of times that the continuously acquired coefficients K1 and / or K2 are out of the corresponding out-of-control intervals exceeds N times, wherein N is a positive integer;

[0094] S1031, yes, then automatically alarming and interrupting the current processing task;

[0095] S1032 (not shown in the figure), no, then executing step S4 until the valid coefficients K1 and K2 are determined;

[0096] S11, establishing a new voltage and distance relationship f(V, d) between the cutting head and the metal plate to be processed for subsequent laser processing: when d(i-n1)<d<=di, d=K1*V; when di<d<=d(i+n2), d=K2*V; and

[0097] S12, no, then continuing to use the current voltage and distance relationship between the laser cutting head and the metal plate to be processed.

[0098] In the embodiment of the present application, before laser processing, the voltage and distance initial relationship f0(V, d) between the laser cutting head and the metal plate to be processed at the current temperature T0 is established by the capacitive sensor for initial laser processing. As the processing proceeds, the temperature T of the capacitive sensor, the light-on time t1 of the cutting head, and the light-off time t2, and other variables affecting the voltage and distance relationship are collected in real time, and then the collected variables are judged, including but not limited to whether the difference between T and T0 that has not been calibrated is greater than △T, whether the difference between T and Ta that has been calibrated a times is greater than △T, wherein the temperature at which calibration is performed is Ta, and a represents the number of times, such as the temperature at the first calibration T1, the temperature at the second calibration T2, and so on, and whether the time difference between the current light-on time t1 of the cutting head and the previous light-off time t2 is greater than the preset threshold △t.

[0099] When one of the above conditions is met, a new voltage and distance relationship needs to be established, which is different. For the difference between T and T0 that has not been calibrated is greater than △T, or the difference between T and Ta that has been calibrated a times is greater than △T, after the current contour processing is completed with the voltage and distance relationship between the current cutting head and the metal plate to be processed, the cutting head is moved to the next contour processing starting point, and the cutting head is moved to the distance d from the metal plate to be processed to collect the voltage and distance calibration data set. For the time difference between the current light-on time t1 of the cutting head and the previous light-off time t2 is greater than the preset threshold △t, the cutting head is moved to the distance d from the metal plate to be processed at the light-on starting point to collect the voltage and distance calibration data set, wherein the light-on starting point of the cutting head can be the starting point of the contour to be processed, or the starting point of the remaining unprocessed part of the contour of the processed part.

[0100] When collecting the voltage and distance calibration data set, the cutting head is moved and then stationary for t milliseconds to dissipate the shock, and then the corresponding data set (v, d) is collected. The interval relationship between the different data obtained is established, that is, by obtaining the ratio K1 of (di-d(i-n1)) / (Vi-V(i-n1)) and the ratio K2 of (d(i+n2)-di) / (V(i+n2)-Vi), under the condition of d(i-n1)<d<=di, the relationship d=K1*V is adopted; under the condition of di<d<=d(i+n2), the relationship d=K2*V is adopted.

[0101] Of course, it is also necessary to determine whether K1 and K2 meet the use, that is, to determine whether K1 and K2 are located in the corresponding preset threshold interval, if yes, K1 and K2 are used as the coefficients of the voltage and distance relationship between the cutting head and the metal plate to be processed; if not, it is further determined whether the coefficients K1 and / or K2 exceed the corresponding preset threshold interval, but do not exceed the corresponding out-of-control interval, if one of K1 and K2 exceeds the corresponding preset threshold interval but does not exceed the corresponding out-of-control interval, and the other does not exceed the corresponding preset threshold interval, then the coefficient which does not exceed the corresponding preset threshold interval is directly applied, and the coefficient which exceeds the corresponding preset threshold interval but does not exceed the corresponding out-of-control interval takes the end value of the adjacent out-of-control interval; if K1 and K2 both exceed the corresponding preset threshold interval but do not exceed the corresponding out-of-control interval, then the corresponding end value of the out-of-control interval is taken respectively; if K1 and K2 both exceed the corresponding out-of-control interval, then the coefficients K1 and K2 are not used this time, and the step S4 is returned to continue execution. Of course, if the coefficients K1 and K2 are not used all the time, they will not go down indefinitely, and when the number of times that the continuously obtained coefficients K1 and / or K2 exceed the corresponding out-of-control interval exceeds N times, an automatic alarm will be given and the current processing task will be interrupted, that is, stopped, so that personnel can intervene; and when the number of times that the continuously obtained coefficients K1 and / or K2 exceed the corresponding out-of-control interval does not exceed N times, the execution continues until valid coefficients K1 and K2 are obtained, or until the current processing task is interrupted automatically.

[0102] If the calibration has not been performed, T-T0<=△T, or if the calibration has been performed a times, T-Ta<=△T, where the temperature at which the calibration is performed is Ta, where a represents the number of times, such as the temperature at the first calibration is T1, the temperature at the second calibration is T2, and so on, and if the time length difference between the light-on time t1 of the cutting head and the adjacent light-off time t2 is less than or equal to the preset threshold value △t, such that the new voltage-distance relationship is not triggered, the current voltage and distance relationship between the laser cutting head and the metal plate to be processed is continued to perform the processing task.

[0103] Step S12 is the negative result of step S3.

[0104] As Figure 11As shown in the figure, curve A represents the ideal voltage-distance relationship curve of the capacitive sensor under conditions free from external interference. Ideally, the voltage and distance of the capacitive sensor can be understood as being correlated in a fixed ratio. However, in reality, after the capacitive sensor heats up during laser processing, it will deviate upwards and / or downwards from the ideal curve. This deviation from the ideal curve is collectively referred to as degradation, as shown by the degradation curves B and C. Since both distance and voltage have maximum values, they will intersect at (Hmax, Vmax) on a coordinate system. However, this intersection is not specifically correlated; they are independent of each other and are only mathematically intersecting.

[0105] like Figure 12 As shown in the figure, curve A is still the ideal voltage-distance relationship curve of the capacitive sensor under the condition of no interference from external factors, while curve C is the calibration curve obtained after using the laser processing distance calibration method disclosed in the embodiments of this application. In the 0-di interval, the calibration coefficient K0 is used, the compensation coefficient K1 is used in the di-di+1 interval, and the compensation coefficient K2 is used in the di+1-dmax interval. This scheme is a fast and real-time calibration mechanism. To obtain better results, the number of measurement points can be increased, that is, K3, K4, K5... can be established. Among them, the 0-di segment is rarely used in actual processing, and when it is used, the corresponding voltage-distance relationship f0(v,d) degrades less. Therefore, K0 can be replaced by K1.

[0106] This application also discloses a computer storage medium that is readable and stores a computer program. When executed by a processor, the computer program causes the processor to perform the calibration method described above. The storage medium can be used to store the laser processing distance calibration method disclosed in this application.

[0107] This application also discloses a computer device, including a memory and a processor. The memory stores a computer program, which, when executed by the processor, causes the processor to perform the calibration method as described above.

[0108] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program. The program can be stored in a non-volatile computer readable storage medium, and when the program is executed, the processes of the above-mentioned embodiments of the methods can be included. Any reference to memory, storage, databases, or other media in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration but not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0109] It should be noted that the definition of each step involved in the present application does not limit the order of the steps without affecting the implementation of the specific scheme. The steps written in the front can be executed first, or executed later, or even executed at the same time, as long as the present application can be implemented. It should be considered as belonging to the protection scope of the present application.

[0110] The above-described embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it should not be understood as limiting the scope of the patent of the present application. It should be noted that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of protection of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A method of calibrating a laser processing distance, characterized by, The method comprises the following steps: establishing an initial relationship f0(V, d) between voltage and distance between the laser cutting head and the metal plate to be processed at a T0 temperature for initial laser processing; collecting the temperature T of the capacitive sensor in real time; if T-T0>△T, adjusting the distance between the cutting head and the metal plate to be processed to d, and collecting the corresponding voltage V between the cutting head and the metal plate to be processed; obtaining a ratio K1 of (di-d(i-n1)) / (Vi-V(i-n1)) and a ratio K2 of (d(i+n2)-di) / (V(i+n2)-Vi), wherein i, n1, n2 and i-n1 are positive integers; establishing a new relationship f(V, d) between voltage and distance between the cutting head and the metal plate to be processed: when d(i-n1)<d<=di, d=K1*V; when di<d<=d(i+n2), d=K2*V; and using the new relationship f(V, d) for subsequent laser processing; The calibration method further comprises: collecting the light-on time t1 and the light-off time t2 of the cutting head; determining whether the time difference between the current light-on time t1 and the previous light-off time t2 is greater than a preset threshold△t; and if yes, establishing a new relationship f(V, d) between voltage and distance between the cutting head and the metal plate to be processed and using the new relationship f(V, d) for subsequent laser processing.

2. The calibration method of claim 1, wherein, The "adjusting the distance between the cutting head and the metal plate to be processed to d, and collecting the corresponding voltage V between the cutting head and the metal plate to be processed" comprises: moving the cutting head to a distance d from the metal plate to be processed; stopping the cutting head for t milliseconds; and collecting the voltage V between the cutting head and the metal plate to be processed.

3. The method of calibrating of claim 1, wherein, The calibration method further comprises: if T-Ta>△T, establishing a new relationship f(V, d) between voltage and distance between the cutting head and the metal plate to be processed and using the new relationship f(V, d) for subsequent laser processing, wherein the temperature at which the calibration is performed is Ta, and a represents the number of times, the temperature at the first calibration is T1, the temperature at the second calibration is T2, and so on.

4. The method of calibrating of claim 1, wherein, The "if T-T0>△T, establishing a new relationship f(V, d) between voltage and distance between the cutting head and the metal plate to be processed and using the new relationship f(V, d) for subsequent laser processing" comprises: if T-T0>△T and no calibration has been performed, using f0(V, d) to establish a new relationship f(V, d) between voltage and distance between the cutting head and the metal plate to be processed when the cutting head moves to the starting point of the next contour processing after the current contour processing is completed, and using the new relationship f(V, d) for the current laser processing.

5. The method of calibration of claim 3, wherein, The "if T-Ta>△T, establishing a new relationship f(V, d) between voltage and distance between the cutting head and the metal plate to be processed and using the new relationship f(V, d) for subsequent laser processing" comprises: if T-Ta>△T and a calibration has been performed a times, using fa(V, d) to establish a new relationship f(V, d) between voltage and distance between the cutting head and the metal plate to be processed when the cutting head moves to the starting point of the next contour processing after the current contour processing is completed, and using the new relationship f(V, d) for the current laser processing, wherein a is a positive integer.

6. The method of calibration of claim 4, wherein, The "if yes, establishing a new relationship f(V, d) between voltage and distance between the cutting head and the metal plate to be processed and using the new relationship f(V, d) for subsequent laser processing" comprises: Yes, the cutting head is at the current open light point position, and a new relationship f(V, d) between the voltage and distance between the cutting head and the metal plate to be processed is established and used for the current laser processing.

7. The method of calibrating of claim 1, wherein, The calibration method further comprises: determining whether K1 and K2 are respectively located in the corresponding preset threshold interval; and Yes, K1 and K2 are used as the coefficients of the voltage and distance relationship f(V, d) between the cutting head and the metal plate to be processed.

8. The method of calibrating of claim 1, wherein, The calibration method further comprises: determining whether the coefficients K1 and / or K2 are outside the corresponding preset threshold interval but not outside the corresponding out-of-control interval; and Yes, the end value of the adjacent out-of-control interval is taken as the value of the corresponding coefficient.

9. The method of calibrating of claim 1, wherein, The calibration method further comprises: determining whether the coefficients K1 and / or K2 are outside the corresponding out-of-control interval; and Yes, neither of the coefficients K1 and K2 is used this time.

10. The method of calibration of claim 9, wherein, The calibration method further comprises: determining whether the number of times that the continuously obtained coefficients K1 and / or K2 are outside the corresponding out-of-control interval exceeds N times, where N is a positive integer; Yes, an automatic alarm is given and the current processing task is interrupted; and No, the current voltage and distance relationship between the laser cutting head and the metal plate to be processed is continued to be used to complete the current contour processing, and at the start point of the next contour processing, the acquisition is continued until the effective coefficients K1 and K2 are determined.

11. A method of calibrating a laser processing distance, characterized by, It comprises: establishing an initial voltage and distance relationship f0(V, d) between the laser cutting head and the metal plate to be processed at the temperature T0 of the capacitive sensor for initial laser processing; real-time acquisition of the temperature T of the capacitive sensor, the open light time t1 of the cutting head, and the off light time t2; determining whether the difference T-T0 has not been executed calibration is greater than △T, or the difference T-Ta has been executed a times of calibration is greater than △T, where the temperature at the time of execution of calibration is Ta, where a represents the number of times, the temperature at the first time of calibration is T1, the temperature at the second time of calibration is T2, and so on, or whether the time difference between the current open light time t1 of the cutting head and the previous off light time t2 is greater than the preset threshold value △t; Yes, for the difference T-T0 that has not been executed calibration is greater than △T or the difference T-Ta that has been executed a times of calibration is greater than △T, after the current cutting head and the metal plate to be processed are completed, the cutting head is moved to the next contour processing start point, and the cutting head is moved to a distance d from the metal plate to be processed; and for the time difference between the current open light time t1 of the cutting head and the previous off light time t2 is greater than the preset threshold value △t, the cutting head is moved to a distance d from the metal plate to be processed at the open light start point. The cutting head is stationary for t milliseconds. The corresponding voltage V between the cutting head and the metal plate to be processed is acquired. The ratio K1 of (di-d(i-n1)) / (Vi-V(i-n1)) and the ratio K2 of (d(i+n2)-di) / (V(i+n2)-Vi) are obtained, where i, n1, n2, and i-n1 are positive integers. determining whether K1 and K2 are respectively located in the corresponding preset threshold interval; and Yes, K1 and K2 are used as the coefficients of the voltage and distance relationship f(V, d) between the cutting head and the metal plate to be processed. Yes, then K1 and K2 are used as the coefficients of the voltage and distance relationship between the cutting head and the metal plate to be processed. No, then determine whether the coefficients K1 and / or K2 exceed the corresponding preset threshold interval but do not exceed the corresponding out-of-control interval. Yes, then take the end value of the adjacent out-of-control interval as the value of the corresponding coefficient, and establish a new voltage and distance relationship f(V, d) between the cutting head and the metal plate to be processed for subsequent laser processing. No, then neither of the coefficients K1 and K2 is used. Determine whether the number of times that the continuously obtained coefficients K1 and / or K2 exceed the corresponding out-of-control interval exceeds N times, where N is a positive integer. Yes, then automatically alarm and interrupt the current processing task. No, then use the current voltage and distance relationship between the laser cutting head and the metal plate to be processed to complete the current contour processing, and when the cutting head moves to the starting point of the next contour processing, continue to obtain until the effective coefficients K1 and K2 are determined. Establish a new voltage and distance relationship f(V, d) between the cutting head and the metal plate to be processed for subsequent laser processing: when d(i-n1)<d<=di, d=K1*V; when di<d<=d(i+n2), d=K2*V; and No, then use the current voltage and distance relationship between the laser cutting head and the metal plate to be processed.

12. A computer storage medium, characterized in that, The computer program is stored in the memory and is executed by the processor to make the processor execute the calibration method according to any one of claims 1 to 11.

13. A computer device, comprising: The computer program is stored in the memory and is executed by the processor to make the processor execute the calibration method according to any one of claims 1 to 11.

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