CN214161805U - Laser processing quality monitoring system - Google Patents
Laser processing quality monitoring system Download PDFInfo
- Publication number
- CN214161805U CN214161805U CN202022948188.6U CN202022948188U CN214161805U CN 214161805 U CN214161805 U CN 214161805U CN 202022948188 U CN202022948188 U CN 202022948188U CN 214161805 U CN214161805 U CN 214161805U
- Authority
- CN
- China
- Prior art keywords
- laser
- sound
- laser processing
- workpiece
- equipment
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Laser Beam Processing (AREA)
Abstract
The utility model provides a laser beam machining quality monitoring system can be used to realize the automatic check laser beam machining quality, reduces the loss. The system comprises: the system comprises laser processing equipment, sound acquisition equipment and an upper computer; the laser processing equipment at least comprises a laser, a nozzle and an air source; the laser is used for emitting light pulses, and the light pulses can pass through the nozzle to carry out laser cutting on a workpiece; the gas source is used for providing gas for blowing gas to a cutting seam formed by laser cutting of the workpiece by the nozzle; the sound collecting equipment is installed on the laser processing equipment and used for collecting sound signals aiming at the laser processing equipment; the upper computer is connected with the sound acquisition equipment and the laser processing equipment and is used for receiving the sound signals acquired by the sound acquisition equipment, and the sound signals are used for determining the processing quality of the laser processing equipment.
Description
Technical Field
The utility model relates to a laser beam machining technical field especially relates to a laser beam machining quality monitoring method, device and equipment, storage medium.
Background
Laser machining refers to a process of machining a material using a focused laser beam. During laser processing, the converged laser beams are required to be used so as to achieve the purpose of energy concentration and cutting, meanwhile, the nozzles in the laser processing equipment can assist gas to be rapidly sprayed out towards a cutting seam, so that sundries such as molten stains can be effectively prevented from rebounding upwards, and a focusing lens can be protected.
In some cases, a larger piece of work may be machined, requiring cutting to form multiple slots. However, in the course of machining, there may be some cases where machining defects occur, such as a case where a slit should be formed, a groove is formed instead of a full slit, or the cut end surface is not smooth. Therefore, it is necessary to make a judgment on the processing quality.
At present, usually come to observe the work piece through the naked eye and come to make the judgement to laser beam machining quality, because laser intensity is great in this kind of mode, the unable closely observation of naked eye, so can only wait that monoblock processing is accomplished the back, rethread eyes observe and judge the quality of processing quality, processing has been accomplished this moment, if there is the defective products, then monoblock work piece is all scrapped, causes great loss.
Disclosure of Invention
The utility model provides a laser beam machining quality monitoring system can be used to realize the automatic check laser beam machining quality, reduces the loss.
The first aspect of the utility model provides a laser beam machining quality monitoring system, include: the system comprises laser processing equipment, sound acquisition equipment and an upper computer;
the laser processing equipment at least comprises a laser, a nozzle and an air source; the laser is used for emitting light pulses, and the light pulses can pass through the nozzle to carry out laser cutting on a workpiece; the gas source is used for providing gas for blowing gas to a cutting seam formed by laser cutting of the workpiece by the nozzle;
the sound collecting equipment is installed on the laser processing equipment and used for collecting sound signals aiming at the laser processing equipment;
the upper computer is connected with the sound acquisition equipment and the laser processing equipment and is used for receiving the sound signals acquired by the sound acquisition equipment, and the sound signals are used for determining the processing quality of the laser processing equipment.
According to an embodiment of the present invention, the laser processing apparatus further comprises a laser cutting head, a laser inlet of the laser cutting head is connected to the laser, and a laser outlet of the laser cutting head is connected to the nozzle;
the sound collection device is mounted on the laser cutting head.
According to the utility model discloses an embodiment, sound collection equipment includes two at least microphones, two at least microphones with the air current outlet's of nozzle distance is the same, two at least microphones are the same with the laser outlet's of laser cutting head distance.
According to the utility model discloses an embodiment, sound collection equipment includes four microphones, four microphones for install laser cutting head's longitudinal axis central symmetry on the laser cutting head.
According to one embodiment of the present invention, a sound processor is disposed within the laser cutting head;
the sound processor is connected with all microphones contained in the sound collection equipment and used for receiving sound signals collected by all the microphones contained in the sound collection equipment and sending the sound signals to the upper computer.
According to an embodiment of the present invention, the microphone is a silicon microphone.
According to an embodiment of the utility model, the device also comprises an alarm, and the alarm is connected with the upper computer;
the upper computer is also used for controlling the alarm to give an alarm when the laser processing equipment is abnormal in processing.
According to an embodiment of the invention, the alarm comprises an acoustic and/or optical alarm.
According to an embodiment of the present invention, the gas source is a gas cylinder for oxygen, air and or nitrogen.
According to the utility model discloses an embodiment, the sound signal includes laser processing equipment system internal noise, the laser that the laser instrument sent shine the produced sound on the work piece, and/or the produced sound when the air current of nozzle output flows through the work piece by the slot that laser cutting formed.
The utility model discloses following beneficial effect has:
the embodiment of the utility model provides an in, through set up sound collection equipment on laser processing equipment, can carry out sound collection to laser processing equipment, the sound signal of gathering can cover laser processing equipment in the laser irradiation produced sound on the work piece, the sound of the air current flow through work piece of nozzle output etc, sound collection equipment can send the sound signal of gathering to the host computer, so that whether the host computer can confirm laser processing equipment based on sound signal and process unusually, can inspect laser processing quality automatically, compare and can discover the bad problem of processing more in time in the naked eye observation, reduce the loss of work piece.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.
Fig. 1 is a block diagram of a laser processing quality monitoring system according to an embodiment of the present invention;
fig. 2 is a schematic flow chart of the laser processing quality monitoring method executed by the upper computer according to an embodiment of the present invention;
fig. 3 is a schematic view of normal processing according to an embodiment of the present invention;
FIG. 4 is a schematic view of a processing anomaly according to an embodiment of the present invention;
fig. 5 is a schematic flow chart illustrating the determination of a fourth eigenfrequency according to an embodiment of the present invention;
fig. 6 is a schematic diagram of the positional relationship between the four microphones and the nozzle according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.
The terms "first," "second," "third," "fourth," and the like in the description and in the claims, as well as in the drawings, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
The technical solution of the present invention will be described in detail with specific examples. The following several specific embodiments may be combined with each other, and details of the same or similar concepts or processes may not be repeated in some embodiments.
The utility model provides a laser beam machining quality monitoring system, refer to fig. 1, this system can include: laser processing equipment, sound collection equipment and host computer 106.
The laser processing equipment at least comprises a laser 101, a nozzle 103 and a gas source 104; the laser 101 is used for emitting light pulses which can pass through the nozzle 103 to perform laser cutting on a workpiece; the gas source 104 is used for supplying gas for blowing gas from the nozzle 103 to a slot formed by laser cutting of the workpiece.
The sound collection equipment is installed on the laser processing equipment and used for collecting sound signals aiming at the laser processing equipment. The sound signal may include system internal noise of the laser processing apparatus, sound generated when the laser of the laser 101 irradiates the workpiece, and/or sound generated when the air flow output from the nozzle 103 flows through a slit formed by laser cutting of the workpiece.
Optionally, the laser processing apparatus may further include a laser cutting head 102, the laser 101 may be connected to the laser cutting head 102, for example, the laser 101 may be connected to the laser cutting head 102 through an optical fiber, the laser 101 may emit a light pulse and then output the light pulse through the laser cutting head 102, and the laser cutting head 102 may be aligned with the workpiece to perform laser cutting.
Alternatively, the nozzle 103 may be installed at a laser outlet of the laser cutting head 102, that is, the laser outlet of the laser cutting head 102 is aligned with the jet group, and a light pulse output by the laser cutting head 102 may pass through the nozzle 103 to perform laser cutting on the workpiece.
The gas source 104 may supply gas to the nozzle 103, and the nozzle 103 may blow gas into a slit formed in the workpiece by laser cutting. Optionally, a gas source 104 interface is provided on the side wall of the laser cutting head 102, and the gas source 104 may be connected to the gas source 104 interface through a pipeline, so that the gas output from the gas source 104 may flow to the nozzle 103 through the laser cutting head 102. The gas source 10 is a gas cylinder for oxygen, air and/or nitrogen, such as an oxygen cylinder, and the gas may be oxygen, air and/or nitrogen, although not specifically limited, and may be specifically determined according to a processing material, such as a stainless steel processing material may use compressed air or nitrogen, which is relatively low in cost; the carbon steel processing material can use oxygen, can play a role in oxidation and reduction, and can release heat to facilitate cutting.
Alternatively, a sound collection device may be provided on the laser cutting head 102, so that the sound generated when the laser of the laser 101 is irradiated on the workpiece and the sound generated when the air flow output from the nozzle 103 flows through the slit formed by the laser cutting of the workpiece can be collected at a closer distance.
The upper computer 106 is connected with the sound acquisition equipment and the laser processing equipment and is used for receiving sound signals acquired by the sound acquisition equipment, and the sound signals are used for determining the processing quality of the laser processing equipment.
Since the sound signals in good or bad processing have different frequencies, the host computer 106 can determine the processing quality of the laser processing apparatus by identifying the frequencies of the sound signals, for example, when the frequency of the sound signal is different from the sound frequency in normal processing by more than a set range, it can determine that the processing of the laser processing apparatus is abnormal, i.e., the processing of the laser processing apparatus is bad, which is only an example here.
When the laser processing equipment is used for processing normally, the processed workpiece is cut completely and has a smooth section. The poor processing conditions may include the following:
1. the workpiece is directly cut out;
2. after cutting completely, adhering slag at the bottom;
3. after cutting through, the melted metal is re-solidified due to insufficient blowing and is accumulated inside the cross section of the workpiece;
4. the light path is not perpendicular to the material, so that the light path can be cut through or not cut through in different directions.
Of course, there may be other situations where the laser processing equipment does not process well, and they are not listed here.
In any case, the sound signals are different from each other in comparison with the normal condition, mainly because the sound wave resonant frequencies are different when the airflow flows through the slots with different depths, widths and side wall shapes.
The embodiment of the utility model provides an in, through set up sound collection equipment on laser processing equipment, can carry out sound collection to laser processing equipment, the sound signal of gathering can cover laser processing equipment in laser instrument 101's laser irradiation produced sound on the work piece, the sound of the air current flow work piece of nozzle 103 output etc, sound collection equipment can send the sound signal of gathering to host computer 106, so that host computer 106 can confirm whether laser processing equipment processes unusually based on sound signal, can inspect laser processing quality automatically, compare in the visual observation can more in time discover the bad problem of processing, reduce the loss of work piece.
Preferably, the upper computer 106 may execute the laser processing quality monitoring method shown in fig. 2, so as to better monitor the laser processing quality. The method comprises the following steps:
s100: in the process that laser processing equipment processes a first workpiece, sound acquisition equipment is controlled to acquire sound signals aiming at the laser processing equipment, and first sound signals formed by processing and acquired by the sound acquisition equipment in each monitoring period are acquired;
s200: extracting a first set of characteristic frequencies of the first sound signal from the first sound signal;
s300: obtaining a third characteristic frequency from the first characteristic frequency set based on the determined first characteristic frequency and the second characteristic frequency; the first characteristic frequency is a characteristic frequency of system internal noise of the laser processing equipment, the second characteristic frequency is a frequency of light pulses emitted by a laser in the laser processing equipment, and the third characteristic frequency is used for representing a characteristic frequency of sound generated when air flow output by a nozzle in the laser processing equipment flows through a cutting seam formed by laser cutting of the first workpiece in a monitoring period when the first sound signal is collected;
s400: and determining whether the current machining of the first workpiece by the laser machining equipment is abnormal or not according to the third characteristic frequency and a determined fourth characteristic frequency, wherein the fourth characteristic frequency is the characteristic frequency of sound generated when the airflow output by the nozzle flows through a slot formed by laser cutting of the second workpiece when the laser machining equipment machines the second workpiece normally.
With reference to fig. 1, the main execution body of the laser processing quality monitoring method according to the embodiment of the present invention is the upper computer 106, and further may be a processor of the upper computer 106, where the processor may be one or more, and the processor may be a general processor or a special processor.
In step S100, in the process of processing the first workpiece 10 by the laser processing apparatus, the sound collection apparatus is controlled to collect sound signals for the laser processing apparatus, and first sound signals formed by processing collected by the sound collection apparatus in each monitoring period are obtained.
The first workpiece 10 may be any workpiece to be machined, and a series of sounds are usually emitted during the machining of the first workpiece 10 by the laser machining apparatus, including system internal noise of the laser machining apparatus, sounds emitted by the laser 101 when light pulses irradiate the first workpiece 10, and sounds generated when the air flow output from the nozzle 103 flows through a slot formed by cutting the first workpiece 10.
The sound signal is collected by controlling the sound collecting device to the laser processing device in the process, so that the series of sounds can be collected, and the upper computer 106 can obtain the sound signals. In other words, the first sound signal contains the series of sounds described above.
The machining here is laser cutting of the first workpiece 10 by the light pulse emitted from the laser 101, and blowing of the slit cut out of the first workpiece 10 by the air flow output from the nozzle 103. The upper computer 106 can control the laser 101 to emit light pulses and control the air source 104 to supply air for processing. Generally, the laser 101 and the gas source 104 are started and stopped simultaneously.
The process of the laser processing apparatus processing the first workpiece 10 may refer to a period of time from when the laser 101 starts emitting the light pulse to when the laser 101 stops emitting the light pulse; alternatively, the period of time from when the gas source 104 begins supplying gas to when the gas source 104 stops supplying gas.
The duration of the process of processing the first workpiece 10 by the laser processing apparatus is relatively long, for example, several seconds, several tens of seconds, etc., in order to find out the abnormal processing condition in time, in this embodiment, the whole process is divided into a plurality of monitoring periods, and the duration of the monitoring period may be, for example, on the order of milliseconds, for example, 10 milliseconds. In each monitoring period, the first sound signal acquired by the sound acquisition equipment is sent to the upper computer 106 so as to perform subsequent steps
In step S200, a first characteristic frequency set of the first sound signal is extracted from the first sound signal.
The first sound signal is a time domain signal, and the first characteristic frequency set can be obtained by means of time-frequency domain conversion. Preferably, since the duration of the monitoring period is short, the first sound signal may be converted into a frequency domain signal by using a Short Time Fourier Transform (STFT) to obtain the first characteristic frequency set.
The first set of characteristic frequencies may be presented in a spectral manner or may be presented in a frequency set manner.
The first characteristic frequency set includes frequencies of sounds collected by the sound collection device during the laser processing, including a characteristic frequency of system internal noise of the laser processing device, a frequency of sound emitted by the laser 101 and irradiated onto the first workpiece 10 by a light pulse, and a characteristic frequency of sound generated when an air flow output from the nozzle 103 of the laser processing device flows through a slit formed by laser cutting of the first workpiece 10 during a monitoring period of the first sound signal.
In step S300, a third characteristic frequency is obtained from the first characteristic frequency set based on the determined first characteristic frequency and the second characteristic frequency; the first characteristic frequency is the characteristic frequency of the system internal noise of the laser processing equipment, the second characteristic frequency is the frequency of the light pulse emitted by the laser 101 in the laser processing equipment, and the third characteristic frequency is used for representing the characteristic frequency of the sound generated when the airflow output by the nozzle 103 in the laser processing equipment flows through the slot formed by the laser cutting of the first workpiece 10 in the monitoring period of acquiring the first sound signal.
The system internal noise of the laser processing apparatus may include sound of the driver operation, electrical noise (including electrical noise of various lines or devices), and the like. The system internal noise of the laser processing apparatus is generally constant regardless of whether the workpiece is processed or not, and accordingly, the characteristic frequency of the system internal noise of the laser processing apparatus is also constant. Therefore, the characteristic frequency of the system internal noise of the laser processing apparatus, i.e., the first characteristic frequency, can be determined in advance.
Optionally, the first characteristic frequency is determined by:
when the laser processing equipment runs but does not carry out processing operation, controlling sound acquisition equipment to acquire sound signals aiming at the laser processing equipment and acquiring a second sound signal, acquired by the sound acquisition equipment within a set time length, formed by the running of the laser processing equipment;
and extracting the characteristic frequency of the second sound signal from the second sound signal to obtain a first characteristic frequency.
The laser processing apparatus operating but not performing the processing operation means that the laser processing apparatus is in an operating state but the laser 101 and the gas source 104 are not operated. In this case, system internal noise of the laser processing apparatus may be collected, and the second acoustic signal may characterize the system internal noise of the laser processing apparatus.
The second sound signal is a time domain signal, and the second sound signal can be converted into a frequency domain signal by adopting a fourier transform mode to obtain the first characteristic frequency.
It is understood that the frequencies of different noises may be different, and therefore, the first characteristic frequency may be composed of a plurality of different frequencies, as long as the frequencies of the system internal noise of the laser processing apparatus can be covered, which is not limited specifically.
The frequency of the sound radiated onto the first workpiece 10 by the light pulse emitted from the laser 101 is the same as the frequency of the light pulse emitted from the laser 101. Because the laser 101 emits light not continuously but individually, and the frequency of the light pulse emitted by the laser 101 is controlled by the upper computer 106, for example, the laser 101 can be controlled by the upper computer 106 to emit laser with a frequency of 5000Hz, at this time, 5000 light pulses are emitted every second, and the laser can emit sound with the same frequency, that is, sound with a frequency of 5000Hz when striking on the workpiece. The frequency of the pulses of light emitted by the laser 101 is also generally constant, and predictable, if at all, whether the workpiece is being machined good or bad. Therefore, the frequency of the sound of the light pulse emitted by the laser 101 impinging on the first workpiece 10, that is, the frequency of the light pulse emitted by the laser 101, that is, the second characteristic frequency, can be determined in advance.
However, the sound of the ejected air flow passing through the slit of the first workpiece 10 during the machining process varies depending on the quality of the machining.
As shown in fig. 3, when the machining is normal, since the height of the nozzle 103 (the distance from the nozzle 103 to the machined part) is almost constant, the blowing air pressure is almost constant, and the slit width is almost constant throughout the process, the frequency of sound generated by the air flow passing through the slit is almost constant (varies within a small range).
When the processing is poor, the nozzle 103 shakes up and down, the gas pressure of the gas passing through the slit changes, the slit width changes, and even if the gas is cut tight (the gas cannot pass through the slit) seriously, the frequency of the sound signal changes sharply. Since there are many kinds of defects, the frequency of the sound signal is not a very constant value when the processing is defective. As shown in fig. 4, the air flow passes through the nozzle 103, but due to poor machining and no cutting through the slit, the air flow returns upward, and the sound frequency at this time is greatly different from that at the time of normal machining.
Therefore, the processing quality can be determined based on the characteristic frequency of the sound generated when the air flow output from the nozzle 103 flows through the slit formed by the laser cutting of the first workpiece 10.
Whether the machining is good or bad, the system internal noise of the laser machining apparatus, the sound of the light pulse emitted from the laser 101 impinging on the workpiece are always present, and the frequency is always constant or substantially constant, so that it can be determined in advance that the first characteristic frequency and the second characteristic frequency obtain the third characteristic frequency from the first characteristic frequency set based on the first characteristic frequency and the second characteristic frequency.
Optionally, obtaining a third eigenfrequency from the first eigenfrequency set based on the determined first eigenfrequency and the second eigenfrequency may include the following steps:
filtering out a first characteristic frequency and a second characteristic frequency from the first characteristic frequency set;
and determining the frequency component with the largest proportion in the filtered characteristic frequencies as a third characteristic frequency.
After the first characteristic frequency and the second characteristic frequency are filtered from the first characteristic frequency set, more characteristic frequencies may exist, and the frequency component with the largest ratio is determined as the third characteristic frequency.
The frequency component with the maximum ratio is explained by the angle of the frequency spectrum, the abscissa of the frequency spectrum represents the frequency, the ordinate of the frequency spectrum represents the density, and the third characteristic frequency is the frequency component with the maximum density in the frequency spectrum formed by filtering the obtained characteristic frequency.
In step S400, it is determined whether the current machining of the first workpiece 10 by the laser machining apparatus is abnormal according to the third characteristic frequency and a determined fourth characteristic frequency, where the fourth characteristic frequency is a characteristic frequency of a sound generated when the airflow output by the nozzle 103 flows through a slot formed by laser cutting of the second workpiece when the machining of the second workpiece by the laser machining apparatus is normal.
Alternatively, referring to fig. 5, the fourth characteristic frequency is determined by:
t100: in the process that the laser processing equipment processes a second workpiece, controlling sound collection equipment to collect sound signals aiming at the laser processing equipment, and acquiring third sound signals collected by the sound collection equipment in the process;
t200: when the laser processing equipment is determined to be processing the second workpiece normally, extracting a second characteristic frequency set of the third sound signal from the third sound signal;
t300: filtering the first and second characteristic frequencies from the second set of characteristic frequencies;
t400: and determining the frequency component with the largest proportion in the filtered characteristic frequencies as the fourth characteristic frequency.
The above-described steps T100-T400 may be performed before step S100.
Since there may be multiple machining locations on one workpiece, the first workpiece 10 and the second workpiece may be the same workpiece but the two machining locations are different, or the first workpiece 10 and the second workpiece may be different workpieces. When the second workpiece and the first workpiece 10 are different workpieces, the second workpiece and the first workpiece 10 have the same material and thickness.
When the fourth characteristic frequency is determined, the requirement of real-time performance is not required, so that the processing process does not need to be divided into a plurality of monitoring periods, and the sound signal acquired by the sound acquisition device in the whole process of processing the second workpiece by the laser processing device can be used as the third sound signal.
When the processing is completed, if the laser processing device processes the second workpiece normally, the third sound signal at this time is in line with expectation, and the second characteristic frequency set of the third sound signal can be extracted from the third sound signal.
The third sound signal is a time domain signal, and the fourier transform may be used to convert the third sound signal into a frequency domain signal to obtain a second characteristic frequency set.
The second characteristic frequency set includes a characteristic frequency of system internal noise of the laser processing apparatus (i.e., the first characteristic frequency), a frequency of a sound of the laser 101 emitting the optical pulse impinging on the second workpiece (since the frequency of the optical pulse is not changed, the frequency here is also the second characteristic frequency), and a characteristic frequency of a sound generated when the air flow output from the nozzle 103 flows through a slit formed by laser cutting of the second workpiece during processing of the second workpiece by the laser processing apparatus.
After the first characteristic frequency and the second characteristic frequency are filtered from the second characteristic frequency set, the characteristic frequency of the sound generated when the airflow output by the nozzle 103 flows through the slot formed by the laser cutting of the second workpiece in the process of processing the second workpiece by the laser processing equipment can be obtained, and of course, there may be more characteristic frequencies, and the frequency component with the largest ratio among the characteristic frequencies is determined as the fourth characteristic frequency.
Knowing the frequency of sound when the air flow outputted from the nozzle 103 flows through the slit of the workpiece when the machining is normal, i.e., the fourth characteristic frequency, it is possible to determine whether the laser machining is abnormal based on the fourth characteristic frequency.
In one embodiment, the step S400 of determining whether the current machining of the first workpiece 10 by the laser machining apparatus is abnormal according to the third characteristic frequency and the determined fourth characteristic frequency includes:
checking whether the third characteristic frequency meets a first condition, wherein the first condition is as follows: the third characteristic frequency is less than or equal to a fifth characteristic frequency or more than or equal to a sixth characteristic frequency, wherein the fifth characteristic frequency is a product of a first coefficient and a fourth characteristic frequency, the sixth characteristic frequency is a product of a second coefficient and a fourth characteristic frequency, the first coefficient is less than 1, and the second coefficient is more than 1;
if yes, the current processing abnormity of the first workpiece 10 by the laser processing equipment is determined.
For example, the third characteristic frequency satisfying the first condition may be represented in the following manner:
f≤0.9Fn2or 1.1Fn2≤f
Wherein F represents a first characteristic frequency, Fn2Representing the fourth eigenfrequency, the first coefficient is 0.9 and the second coefficient is 1.1. It is to be understood that the first condition is exemplary only, not limiting, and that certain modifications are possible within the scope of sound.
In this embodiment, if the third characteristic frequency meets the first condition, it is determined that the laser processing apparatus is currently abnormal in processing the first workpiece 10; if not, the laser processing device processes the first workpiece 10 normally.
In another embodiment, the step S400 of determining whether the current machining of the first workpiece 10 by the laser machining apparatus is abnormal according to the third characteristic frequency and the determined fourth characteristic frequency includes:
checking whether the third characteristic frequency meets a first condition, wherein the first condition is as follows: the third characteristic frequency is less than or equal to a fifth characteristic frequency or more than or equal to a sixth characteristic frequency, wherein the fifth characteristic frequency is a product of a first coefficient and a fourth characteristic frequency, the sixth characteristic frequency is a product of a second coefficient and a fourth characteristic frequency, the first coefficient is less than 1, and the second coefficient is more than 1;
if yes, when the third characteristic frequency in the N monitoring periods is continuously checked to meet the first condition, N is greater than 1, and it is determined that the laser processing equipment is abnormal in processing the first workpiece 10 currently.
In the above embodiment, only the case in one monitoring period is referred to, and there is a possibility that an error exists. Therefore, in this embodiment, if the third characteristic frequency meets the first condition, the current processing abnormality of the laser processing apparatus on the first workpiece 10 is not directly determined, but the condition of the N monitoring periods is referred to, and when the third characteristic frequency in the N monitoring periods has been continuously checked to meet the first condition, the current processing abnormality of the laser processing apparatus on the first workpiece 10 is determined, so that the monitoring result can be ensured to be more accurate.
N is greater than 1, such as 100, although this is merely an example and not a limitation.
In the above embodiment, the process of processing the first workpiece 10 by the laser processing apparatus is divided into a plurality of monitoring periods, the sound collection apparatus may collect the first sound signal from the laser processing apparatus in each monitoring period, and after the first characteristic frequency set is extracted from the first sound signal, the characteristic frequency (i.e., the third characteristic frequency) of the sound generated when the airflow output by the nozzle 103 of the laser processing apparatus flows through the slit formed by laser cutting of the first workpiece 10 in the monitoring period, where the airflow output by the nozzle 103 of the laser processing apparatus in the monitoring period where the first sound signal is collected, is collected from the first characteristic frequency set based on the condition that the system internal noise of the laser processing apparatus is not changed and the frequency of the light pulse emitted by the laser 101 of the laser processing apparatus is not changed, and the third characteristic frequency may be regarded as a real-time characteristic frequency, and is high in real-time performance, and based on the third characteristic frequency, And when the laser processing equipment is used for processing the second workpiece normally, the characteristic frequency (namely, the fourth characteristic frequency) of the sound generated when the airflow output by the nozzle 103 flows through the slot formed by laser cutting of the second workpiece determines whether the current processing of the laser processing equipment on the first workpiece 10 is abnormal or not, so that the abnormal processing condition of the laser processing equipment can be timely monitored, the first workpiece 10 does not need to be inspected by naked eyes after being completely processed, the whole workpiece can be prevented from being scrapped, and the loss is reduced.
In one embodiment, the laser processing quality monitoring system may further include an alarm (not shown), which is connected to the upper computer 106; the upper computer 106 is also used for controlling an alarm to give an alarm when the laser processing equipment is abnormal in processing.
Optionally, in the foregoing embodiment, after determining that the laser processing apparatus is currently abnormal in processing the first workpiece 10, the laser processing quality monitoring method further includes: and sending an alarm signal and controlling the laser processing equipment to stop processing.
The alarm signal of the upper computer 106 can be sent to an alarm, and the alarm can comprise an acoustic and/or optical alarm, and the acoustic and/or optical alarm is carried out through the alarm.
When the laser processing equipment is abnormal in processing, an alarm is given, and workers can be informed to timely overtake to check the processing condition; and the laser processing equipment is controlled to stop processing, so that the damage can be stopped in time, and the workpiece is prevented from being processed continuously.
In one embodiment, a sound collection apparatus includes: at least two microphones located above the nozzle 103 and at the same distance from the airflow outlet of the nozzle 103.
Alternatively, the microphone included in the sound collection device may be disposed in the laser cutting head 102.
Optionally, in the foregoing embodiment, the laser processing quality monitoring method further includes:
aiming at sound signals synchronously acquired by at least two microphones, filtering components with different frequencies in the sound signals, wherein the acquisition periods of the at least two microphones are smaller than the monitoring period;
the first sound signal of each monitoring period is a sound signal obtained by filtering out components with different frequencies from the sound signals collected by at least two microphones in the monitoring period.
The two steps are executed in each acquisition cycle, and after the microphone included in the sound acquisition equipment acquires the sound signal synchronously each time, components with different frequencies in the sound signal are filtered.
For example, the sound collection apparatus includes two microphones, a first microphone and a second microphone, wherein the first microphone collects sounds with frequencies F1 and F2, and the second microphone collects only sounds with frequency F1 during a collection period, so that the sounds with frequency F2 are filtered and only the sounds with frequency F1 are retained.
Preferably, as shown in fig. 6, the sound collection device comprises four microphones symmetrically disposed on the laser cutting head 102 above the nozzle 103. In particular, the four microphones are symmetrically arranged centered on the longitudinal axis of the laser cutting head 102. In this way, the four microphones are at the same distance from the longitudinal axis of the laser cutting head 102 and also at the same distance from the nozzle 103.
The sound collection equipment structurally collects sound signals by using four microphones which are arranged in central symmetry, the influence of environmental noise on monitoring results can be reduced, when external environment emits noise such as a person speaking, the time required for sound propagation is different when the sound reaches each microphone, so that the four microphones cannot receive the sound at the same time, and the sound collection equipment can be used as different frequency components to be filtered.
The laser cutting head 102 can be internally provided with a sound processor, the sound processor can only be responsible for collecting sound signals collected by a microphone included in the sound collecting equipment and sending the sound signals to the upper computer 106, and the rest processing can be realized by the upper computer 106.
The sound signals referred to in the foregoing embodiments may all be sound signals obtained by filtering different frequency components from sound signals collected by microphones included in the sound collection device in corresponding time periods.
Optionally, the microphone is a silicon microphone. The sound frequency range which can be collected by the silicon microphone is within 0-20KHz, the collection range is wider, the precision is higher, and the accuracy of the monitoring result is facilitated.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention.
Claims (10)
1. A laser processing quality monitoring system, comprising: the system comprises laser processing equipment, sound acquisition equipment and an upper computer;
the laser processing equipment at least comprises a laser, a nozzle and an air source; the laser is used for emitting light pulses, and the light pulses can pass through the nozzle to carry out laser cutting on a workpiece; the gas source is used for providing gas for blowing gas to a cutting seam formed by laser cutting of the workpiece by the nozzle;
the sound collecting equipment is installed on the laser processing equipment and used for collecting sound signals aiming at the laser processing equipment;
the upper computer is connected with the sound acquisition equipment and the laser processing equipment and is used for receiving the sound signals acquired by the sound acquisition equipment, and the sound signals are used for determining the processing quality of the laser processing equipment.
2. The laser machining quality monitoring system of claim 1, wherein the laser machining apparatus further comprises a laser cutting head, a laser inlet of the laser cutting head is connected to the laser, and a laser outlet of the laser cutting head is connected to the nozzle;
the sound collection device is mounted on the laser cutting head.
3. The laser machining quality monitoring system of claim 2 wherein the sound collection apparatus includes at least two microphones that are equidistant from the airflow outlet of the nozzle and equidistant from the laser outlet of the laser cutting head.
4. The laser machining quality monitoring system of claim 2 wherein the sound collection apparatus includes four microphones mounted on the laser cutting head symmetrically with respect to a longitudinal axis center of the laser cutting head.
5. The laser machining quality monitoring system of claim 2, wherein a sound processor is disposed within the laser cutting head;
the sound processor is connected with all microphones contained in the sound collection equipment and used for receiving sound signals collected by all the microphones contained in the sound collection equipment and sending the sound signals to the upper computer.
6. The laser processing quality monitoring system of any one of claims 3-5, wherein the microphone is a silicon microphone.
7. The laser processing quality monitoring system of claim 1, further comprising an alarm, wherein the alarm is connected with the upper computer;
the upper computer is also used for controlling the alarm to give an alarm when the laser processing equipment is abnormal in processing.
8. A laser machining quality monitoring system according to claim 7 wherein the alarm comprises an acoustic and/or optical alarm.
9. The laser process quality monitoring system of claim 1, wherein the gas source is a gas cylinder for oxygen, air, and or nitrogen.
10. The laser machining quality monitoring system of claim 1, wherein the sound signal includes noise inside the laser machining apparatus, sound generated by laser light emitted from a laser irradiating a workpiece, and/or sound generated by a gas flow output from the nozzle flowing through a slit formed by laser cutting of the workpiece.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202022948188.6U CN214161805U (en) | 2020-12-10 | 2020-12-10 | Laser processing quality monitoring system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202022948188.6U CN214161805U (en) | 2020-12-10 | 2020-12-10 | Laser processing quality monitoring system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN214161805U true CN214161805U (en) | 2021-09-10 |
Family
ID=77606045
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202022948188.6U Active CN214161805U (en) | 2020-12-10 | 2020-12-10 | Laser processing quality monitoring system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN214161805U (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112504714A (en) * | 2020-12-10 | 2021-03-16 | 上海柏楚数控科技有限公司 | Laser processing quality monitoring method, system, device and equipment and storage medium |
| CN113814586A (en) * | 2021-11-05 | 2021-12-21 | 泰尔重工股份有限公司 | Method for judging puncture state of laser cutting machine based on sound signal |
| CN114043073A (en) * | 2021-11-18 | 2022-02-15 | 哈尔滨工业大学 | A water-assisted laser processing system and method based on real-time monitoring of acoustic signals |
| CN115932044A (en) * | 2022-12-22 | 2023-04-07 | 江苏先进光源技术研究院有限公司 | Real-time detection method for workpiece defects in laser processing process |
| DE102023200082A1 (en) | 2023-01-05 | 2024-07-11 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung eingetragener Verein | Device and system for providing optical real-time information regarding a process by means of an optical neural network, and method for providing the device |
-
2020
- 2020-12-10 CN CN202022948188.6U patent/CN214161805U/en active Active
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112504714A (en) * | 2020-12-10 | 2021-03-16 | 上海柏楚数控科技有限公司 | Laser processing quality monitoring method, system, device and equipment and storage medium |
| CN113814586A (en) * | 2021-11-05 | 2021-12-21 | 泰尔重工股份有限公司 | Method for judging puncture state of laser cutting machine based on sound signal |
| CN113814586B (en) * | 2021-11-05 | 2024-04-09 | 泰尔重工股份有限公司 | Method for judging puncture state of laser cutting machine based on sound signal |
| CN114043073A (en) * | 2021-11-18 | 2022-02-15 | 哈尔滨工业大学 | A water-assisted laser processing system and method based on real-time monitoring of acoustic signals |
| CN115932044A (en) * | 2022-12-22 | 2023-04-07 | 江苏先进光源技术研究院有限公司 | Real-time detection method for workpiece defects in laser processing process |
| CN115932044B (en) * | 2022-12-22 | 2024-02-20 | 江苏先进光源技术研究院有限公司 | Workpiece defect real-time detection method in laser processing process |
| DE102023200082A1 (en) | 2023-01-05 | 2024-07-11 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung eingetragener Verein | Device and system for providing optical real-time information regarding a process by means of an optical neural network, and method for providing the device |
| WO2024146912A1 (en) | 2023-01-05 | 2024-07-11 | Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. | Device and system for providing optical real-time information relating to a process by means of an optical neural network, and method for providing the device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN214161805U (en) | Laser processing quality monitoring system | |
| JP5801564B2 (en) | Method for monitoring the quality of laser processing and systems corresponding thereto | |
| US5045669A (en) | Method and apparatus for optically/acoustically monitoring laser materials processing | |
| CN1188691C (en) | Method for analysing monitering and controlling laser impact cold-forging by using instantaneous plasma spectrographic | |
| CN112504714B (en) | Laser processing quality monitoring method, system, device and equipment and storage medium | |
| EP1081239A1 (en) | Method for setting up and controlling confinement media flow in laser shock peening | |
| JP5129475B2 (en) | Laser shock peening system using time-of-flight monitoring | |
| JPH07502932A (en) | Device and method for determining the operating effect of a work tool | |
| US6629464B2 (en) | Laser shock peening quality assurance by acoustic analysis | |
| CN111195783B (en) | Ultrafast Laser-Water Jet Assisted Mechanical Coupling Group Punching Equipment and Method for Composite Thick Plates | |
| CA2580102A1 (en) | System and method for monitoring drilling process parameters and controlling drilling operation | |
| US4960970A (en) | Method and apparatus for acoustic breakthrough detection | |
| CN109175733B (en) | Device and method for improving laser drilling quality based on online detection technology | |
| JP5649770B2 (en) | Mechanical sheet making equipment | |
| CN110715981B (en) | A method and device for on-line detection of laser shock strengthening based on acoustic emission signal | |
| GB2467296A (en) | Apparatus and method for perforating material | |
| JPWO2020152757A1 (en) | Machining state detector, laser machine and machine learning device | |
| CN109900809A (en) | For the bed die of ultrasonic bonding quality testing, detection system and method | |
| CN117245250B (en) | Acoustic monitoring device and method for water-guided laser processing | |
| US20230041893A1 (en) | Performing consumable diagnostics via spectral analysis | |
| CN112255191A (en) | Laser-induced breakdown spectroscopy and acoustic reflection combined online monitoring system and method | |
| TW202130445A (en) | Method for detecting the operating condition of an optical element arranged along a propagation path of a laser beam of a machine for processing a material, system for carrying out said method and a laser processing machine provided with said system | |
| JP2005305541A (en) | Method and apparatus for monitoring/controlling die machining | |
| JPS62114786A (en) | Machining status monitoring method | |
| CN102310265A (en) | Error detection method and device for laser cutting processing system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |