Smoke concentration detection method and system for laser cutting

Abstract

The invention relates to the technical field of smoke concentration detection, and discloses a smoke concentration detection method and system for laser cutting, and the method comprises the steps: obtaining a workpiece imaging image, and determining a focus passing path according to the workpiece imaging image; analyzing the number and angle of inflection points in the passing path to determine a target cutting speed; obtaining the thickness of a machined workpiece to determine initial power, and determining the number of cutting times according to the initial power; detecting smoke generated in the first cutting stage and the second cutting stage to obtain smoke concentrations, and dividing detection modes into a laser cutting average smoke concentration detection mode and a space average smoke concentration detection mode according to the smoke concentrations; and the smoke coverage range and the laser cutting average smoke concentration coverage range are obtained to determine a safe area. By adjusting parameters in the laser cutting process and the smoke concentration in the safe area, the influence of the smoke concentration in the safe area on the body of an operator is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of smoke concentration detection, and in particular to a smoke concentration detection method and system for laser cutting. Background Art

[0002] The smoke generated during laser cutting may cause pneumoconiosis if inhaled for a long time. Pneumoconiosis is a diffuse pulmonary fibrosis disease caused by long-term inhalation of mineral dust. The main symptoms include coughing, sputum and shortness of breath.

[0003] Chinese patent publication number: CN118010576A discloses a method for detecting smoke particle size and concentration, comprising the following steps: S1. Smoke passes through the filter screens (5) arranged on both sides of the sample pool (4) and is filtered along with the smoke particles, and the smoke particles and target objects (6) pass through the filter screens (5) and enter the sample pool (4); S2. Infrared rays (101) are emitted from the output end of the infrared laser emitting tube (1), and blue rays (201) are emitted from the output end of the blue laser emitting tube (2), and at this time, the infrared rays (101) and the blue rays (201) are alternately emitted at high frequency to the smoke particles and target objects (6) entering the transparent sample pool (4); S3. The infrared rays (101) and the blue rays (201) are emitted along with the smoke particles. The particle target (6) is scattered toward the linear array CCD sensor (3), and the different particles in the smoke particle target (6) cause the infrared rays (101) and the blue rays (201) to emit light beams at different angles inside the linear array CCD sensor (3); S4. As the concentration of smoke particles increases, the scattering intensity of the infrared rays (101) and the blue rays (201) increases synchronously, making the sensitivity of the effective pixel area corresponding to the linear array CCD sensor (3) greater, and the conversion of the light signal sensed in the effective pixel area into an electrical signal, outputting the corresponding position information. The technician determines the concentration of a certain particle in the sample pool (4) based on the size of the signal response value, and then deduces the current degree of thermal runaway of the battery, so as to make corresponding control measures.

[0004] It can be seen that the prior art has the following problems: due to the lack of adjustment of parameters during laser cutting and smoke concentration in the safe area, the smoke concentration is too high, which affects the health of operators. Summary of the invention

[0005] To this end, the present invention provides a smoke concentration detection method and system for laser cutting, which is used to overcome the problem in the prior art that the smoke concentration is too high and affects the health of operators due to the lack of adjustment of parameters during laser cutting and the smoke concentration in a safe area.

[0006] To achieve the above object, the present invention provides a smoke concentration detection method for laser cutting, comprising the following steps:

[0007] The processing workpiece is imaged by an imaging device to obtain an image of the workpiece, and the positioning module determines a focal point passing path according to the image of the workpiece;

[0008] Analyzing the number of inflection points and the inflection point angles in the path through which the focus passes, and determining a target cutting speed according to the number of inflection points and the inflection point angles;

[0009] Obtaining the thickness of the workpiece to be processed, determining the initial power of the laser cutting device according to the thickness of the workpiece to be processed, and determining the number of cutting times of the laser cutting device according to the initial power of the laser cutting device;

[0010] The smoke generated in the first cutting stage and the second cutting stage are respectively detected by a smoke concentration detection device to obtain the smoke concentration. According to the smoke concentration, the detection method is divided into a laser cutting average smoke concentration detection method and a spatial average smoke concentration detection method;

[0011] The smoke coverage is obtained by an infrared imaging device, a safe area is determined according to the smoke coverage and the average smoke coverage density of laser cutting, and the cutting power of the laser cutting device is adjusted according to the average smoke density in the safety area.

[0012] Furthermore, the imaging device is used to image the workpiece to obtain an image of the workpiece, and the positioning module determines the focus path according to the image of the workpiece, including:

[0013] The marking points on the surface of the workpiece are positioned by an imaging device, and the laser cutting device determines the focal point passing path according to the focal point position collected by the positioning module.

[0014] Furthermore, the imaging device is used to image the workpiece to obtain an image of the workpiece, and the positioning module determines the focus path according to the image of the workpiece, including:

[0015] The initial cutting speed of the laser cutting device is adjusted by the number of inflection points in the focus passing path to obtain a first cutting speed.

[0016] Further, based on the first cutting speed, the first cutting speed of the laser cutting device is adjusted according to the inflection point angle to obtain a target cutting speed.

[0017] Furthermore, the smoke concentration detection device detects the smoke generated in the first cutting stage and the second cutting stage respectively to obtain the smoke concentration, and the process of dividing the detection method into a laser cutting average smoke concentration detection method and a spatial average smoke concentration detection method according to the smoke concentration includes:

[0018] The smoke concentration generated during each cutting is detected by a smoke concentration detection device, and the average smoke concentration of laser cutting is obtained based on the detection result and the cutting time of each laser cutting device.

[0019] Furthermore, the process of obtaining the smoke coverage range through the infrared imaging device, determining the safe area according to the smoke coverage range and the average smoke coverage range concentration of the laser cutting, and adjusting the cutting power of the laser cutting device according to the spatial average smoke concentration in the safe area includes:

[0020] Smoke temperature data is collected to generate a smoke coverage range, and the average smoke concentration coverage range of laser cutting is obtained according to the average smoke concentration of laser cutting. The overlapping range of the smoke coverage range and the average smoke concentration coverage range of laser cutting is a safe area.

[0021] Furthermore, the safety area includes:

[0022] A first safety zone, wherein the origin of the first safety zone is centered on the workpiece, the laser cutting direction is the positive diffusion direction, and the zone is determined by the auxiliary gas flow rate;

[0023] The second safety zone, the origin of the second safety zone is centered on the workpiece, the positive diffusion direction is the opposite direction of laser cutting, and the area is determined by the auxiliary gas flow rate.

[0024] Furthermore, the smoke concentration in the first safety area is measured for a spatial average smoke concentration through a smoke detection device, and the power of the laser cutting device is adjusted according to a comparison result between the measurement result and a set spatial average smoke concentration safety value.

[0025] Furthermore, based on the situation that the power of the laser cutting device is adjusted to not satisfy the smoke density in the first safety area, the flow rate of the auxiliary gas of the laser cutting device is adjusted.

[0026] The present invention also provides a smoke concentration detection system for laser cutting applicable to the smoke concentration detection method for laser cutting, comprising:

[0027] An image processing module is used to perform image forming on the surface image of the processed workpiece;

[0028] Positioning module, used for focus positioning of laser cutting device;

[0029] A control module, used for controlling the image processing module and the positioning module;

[0030] The data processing module is connected to the image processing module, the positioning module and the control module, and is used to process the data collected by each module and control the operation process of each module through the control module.

[0031] Compared with the prior art, the beneficial effect of the present invention lies in that the focus path of the workpiece to be processed is acquired through the imaging positioning device, the number of inflection points on the focus path is judged based on the focus path, and the initial cutting speed of the laser cutting device is adjusted according to the number of inflection points of the processing path of the workpiece to obtain the first cutting speed, which can avoid the initial cutting speed of the laser cutting device being too fast due to too many inflection points on the processing path, affecting the processing accuracy, and ensuring the quality of the processed workpiece. When there is no inflection point on the focus path, that is, the focus path is a straight line, the initial cutting speed of the laser cutting device is adjusted according to the smoke concentration data collected by the smoke measuring device. When the smoke concentration is high, the initial cutting speed of the laser cutting device is slowed down to avoid the high smoke concentration affecting the operator's health and causing environmental pollution. When the smoke concentration is low, the initial cutting speed of the laser cutting device is appropriately accelerated to ensure processing efficiency and reduce raw material loss.

[0032] Furthermore, based on the first cutting speed of the laser cutting device, the first cutting speed of the laser cutting device is adjusted according to the inflection point angle to obtain the target cutting speed. By adjusting the inflection point angle in real time, it is possible to avoid the situation where the first cutting speed of the laser cutting device is too fast due to the inflection point angle being too small, and the workpiece cannot be precisely processed, thereby affecting the quality of the workpiece. To ensure the quality of the workpiece, when the absolute value of the inflection point angle is greater than zero and less than the absolute value of the first standard inflection point angle, the compensation parameter for the influence of the first inflection point angle on the cutting speed is selected as the compensation parameter for the influence of any inflection point angle on the target cutting speed of the laser cutting device passing through any inflection point angle. This can ensure that when any inflection point angle is large, A small reduction in the cutting speed of the laser cutting device passing through any inflection point angle can meet the requirement of improving the processing efficiency while ensuring the accuracy of the workpiece being processed; when the absolute value of the inflection point angle is greater than or equal to the absolute value of the second standard inflection point angle is less than or equal to 180°, the compensation parameter for the influence of the third inflection point angle on the cutting speed is selected as the compensation parameter for the influence of any inflection point angle on the target cutting speed of the laser cutting device passing through any inflection point angle, so as to avoid insufficient processing accuracy of the workpiece due to cutting according to the initial cutting speed of the laser cutting device after the first adjustment when the absolute value of the inflection point angle is too large; and ensure that the cutting speed of the cutting device at any inflection point can meet the processing accuracy requirements of the workpiece.

[0033] Furthermore, the number of processing times of the laser cutting device can be estimated by the processing thickness of the workpiece and the initial power of the cutting device. The power of the laser cutting device and the smoke concentration can be adjusted according to the estimated results. If the processing thickness of the workpiece is too thick, the corresponding processing times of the laser cutting device will increase, resulting in an increase in the smoke concentration. If the initial power is too high, the smoke generated when cutting the workpiece will increase, thereby being able to estimate the smoke concentration generated.

[0034] Furthermore, the smoke coverage range is generated by collecting data on smoke temperature through an infrared imaging device. The smoke coverage range distinguishes the smoke concentration through the distance between different temperature zones and the center point. The closer to the center point, the higher the smoke concentration. The safe area is determined by the range circled by the average smoke concentration of laser cutting in the smoke coverage range. The working range of the operator can be determined based on the affected range near the center point. The power of the laser cutting device and the auxiliary gas flow rate during the cutting process are adjusted by the smoke concentration value within the safe area to achieve the purpose of controlling the smoke concentration to a safe concentration and protect the health of the operator.

[0035] Furthermore, the first safety area is an area for performing laser cutting operations, and the area is an irregular sector-shaped area with the workpiece as the center and extending to both sides. The second safety area is an opposite area for performing laser cutting operations. The smoke concentration requirement in the first safety area is higher than that in the second safety area. When the smoke concentration collected by the smoke detection device in the first safety area is high, it means that the initial power of the cutting device is too large or the auxiliary gas flow rate is too fast, which leads to excessive smoke concentration in the first safety area. At this time, the initial power of the cutting device is adjusted to avoid excessive smoke concentration in the first safety area due to excessive initial power, so as to ensure that the smoke concentration in the first safety area is within the set standard smoke concentration.

[0036] Furthermore, the spatial average smoke concentration of the smoke concentration in the first safety area is measured, and the power of the laser cutting device is adjusted by comparing whether the spatial average smoke concentration is within the safety value range of the spatial average smoke concentration in the first safety area. When the spatial average smoke concentration in the first safety area is less than the first safety value of the spatial average smoke concentration in the first safety area, the initial power of the laser cutting device is increased to the first initial power of the laser cutting device according to the difference between the first safety value of the spatial average smoke concentration in the first safety area and the spatial average smoke concentration in the first safety area, so as to ensure the cutting efficiency of the workpiece to be processed and avoid the laser cutting device power being too low, resulting in too slow cutting speed of the workpiece to affect the cutting efficiency; when the spatial average smoke concentration in the first safety area is less than the first safety value of the spatial average smoke concentration in the first safety area, the initial power of the laser cutting device is increased to the first initial power of the laser cutting device according to the difference between the first safety value of the spatial average smoke concentration in the first safety area and the spatial average smoke concentration in the first safety area. When the degree is greater than, equal to or less than the first safety value of the spatial average smoke concentration in the first safety area and is less than, equal to or less than the second safety value of the spatial average smoke concentration in the first safety area, the initial power of the laser cutting device is selected to process the workpiece, which can ensure the efficiency of processing the workpiece; when the spatial average smoke concentration in the first safety area is greater than the second safety value of the spatial average smoke concentration in the first safety area, the initial power of the laser cutting device is reduced to the second initial power of the laser cutting device according to the difference between the spatial average smoke concentration in the first safety area and the first safety value of the spatial average smoke concentration in the first safety area, which can avoid the impact of excessive spatial average smoke concentration in the first safety area on the health of the operator, the sight of the operator, and the processing accuracy of the workpiece. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a flow chart of the smoke concentration detection method for laser cutting in this embodiment;

[0038] Figure 2 This is a process flow chart of obtaining a target cutting speed of the smoke concentration detection method for laser cutting in this embodiment;

[0039] Figure 3 is a system operation flow chart of a smoke concentration detection system for laser cutting that is applicable to a smoke concentration detection method for laser cutting in this embodiment;

[0040] Figure 4 Schematic diagram of the device structure of the smoke concentration detection method and system suitable for laser cutting in this embodiment.

[0041] Figure 4 middle;

[0042] 1-first transmission rod; 2-second transmission rod; 3-first rotating shaft; 4-second rotating shaft; 5-smoke concentration detection device; 6-imaging device; 7-jet device; 8-cutting placement table; 9-sliding rod; 10-first fixed valve; 11-second fixed valve; 12-support column. DETAILED DESCRIPTION

[0043] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0044] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0045] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is merely for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0046] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0047] See also Figure 1-Figure 4 As shown, Figure 1 This is a flow chart of the smoke concentration detection method for laser cutting in this embodiment; Figure 2 This is a process flow chart of obtaining a target cutting speed of the smoke concentration detection method for laser cutting in this embodiment; Figure 3 is a system operation flow chart of a smoke concentration detection system for laser cutting that is applicable to a smoke concentration detection method for laser cutting in this embodiment; Figure 4 Schematic diagram of the device structure of the smoke concentration detection method and system suitable for laser cutting in this embodiment.

[0048] This embodiment provides a smoke concentration detection method for laser cutting, comprising the following steps:

[0049] Step S1, imaging a workpiece by an imaging device to obtain an imaging image of the workpiece, and a positioning module determines a focal point passing path according to the imaging image of the workpiece;

[0050] Step S2, analyzing the number of inflection points and the inflection point angles in the path through which the focus passes, and determining a target cutting speed according to the number of inflection points and the inflection point angles;

[0051] Step S3, obtaining the thickness of the workpiece to be processed, determining the initial power of the laser cutting device according to the thickness of the workpiece to be processed, and determining the number of cutting times of the laser cutting device according to the initial power of the laser cutting device;

[0052] Step S4, using a smoke concentration detection device to detect the concentration of smoke generated in the first cutting stage and the second cutting stage respectively to obtain smoke concentration, and according to the smoke concentration, the detection method is divided into a laser cutting average smoke concentration detection method and a space average smoke concentration detection method;

[0053] Step S5, obtaining the smoke coverage range through the infrared imaging device, determining the safe area according to the smoke coverage range and the average smoke concentration of the laser cutting, and adjusting the cutting power of the laser cutting device according to the average smoke concentration of the space in the safe area.

[0054] This embodiment provides a process of obtaining a target cutting speed of a smoke concentration detection method for laser cutting, including:

[0055] Step S210, obtaining the focus passing path and the number of inflection points in the passing path;

[0056] Step S220, adjusting the initial cutting speed of the laser cutting device according to the number of inflection points to obtain a first cutting speed;

[0057] Step S230, obtaining an inflection point angle based on the first cutting speed;

[0058] Step S240, adjusting the first cutting speed according to the inflection point angle to obtain a target cutting speed.

[0059] Specifically, the imaging device is used to image the workpiece to obtain an image of the workpiece, and the positioning module determines the focus path according to the image of the workpiece, including:

[0060] The marking points on the surface of the workpiece are positioned by an imaging device, and the laser cutting device determines the focal point passing path according to the focal point position collected by the positioning module.

[0061] The imaging device is arranged in the processing assembly, located above the processing workpiece, and generates a processing pattern on the surface of the processing workpiece by collecting image data of the processing workpiece. The focus of the processing pattern on the surface of the processing workpiece is determined by the positioning module through the path.

[0062] Specifically, the imaging device is used to image the workpiece to obtain an image of the workpiece, and the positioning module determines the focus path according to the image of the workpiece, including:

[0063] The initial cutting speed of the laser cutting device is adjusted by the number of inflection points in the focus passing path to obtain a first cutting speed.

[0064] Get the initial cutting speed based on historical processing data,

[0065] Determine the first cutting speed in different situations according to the number of inflection points of the focus path and the initial cutting speed.

[0066] When the number of inflection points of the focus through the path is equal to zero, the first cutting speed is determined according to the initial cutting speed, and the first cutting speed is positively correlated with the initial cutting speed.

[0067] Wherein, the positive correlation ratio of the first cutting speed to the initial cutting speed is determined by a preset proportional influence compensation parameter;

[0068] The number of inflection points of the focus path is measured by an imaging device;

[0069] Setting a first standard number of inflection points of a focus path and a second standard number of inflection points of a focus path, wherein the first standard number of inflection points of a focus path and the second standard number of inflection points of a focus path are obtained based on historical data of the number of inflection points of a focus path;

[0070] For the case where the number of inflection points of the focus path is greater than zero and less than the number of inflection points of the first standard focus path, the ratio of 1 plus the difference between the number of inflection points of the first standard focus path and the number of inflection points of the focus path to the number of inflection points of the first standard focus path is multiplied by the initial cutting speed.

[0071] The first cutting speed is positively correlated with the initial cutting speed, and is positively correlated with the ratio of the difference between the number of inflection points of the first standard focus passing path and the number of inflection points of the focus passing path to the number of inflection points of the first standard focus passing path;

[0072] In the case where the number of inflection points of the focus passing path is greater than the number of inflection points of the first standard focus passing path and less than the number of inflection points of the second standard focus passing path, the initial cutting speed is selected as the first cutting speed of the laser cutting device;

[0073] For the case where the number of inflection points of the focus path is greater than the number of inflection points of the second standard focus path, the ratio of the difference between the number of inflection points of the second standard focus path and the number of inflection points of the focus path to the number of inflection points of the second standard focus path is multiplied by the initial cutting speed to determine the initial cutting speed.

[0074] Among them, the first cutting speed is positively correlated with the initial cutting speed, and negatively correlated with the ratio of the difference between the number of inflection points of the first standard focus passing path and the number of inflection points of the focus passing path to the number of inflection points of the first standard focus passing path;

[0075] For example:

[0076] The initial cutting speed is 10 cm / s, the number of inflection points of the first standard focus through the path is set to 5, and the number of inflection points of the second standard focus through the path is set to 10;

[0077] The proportional effect compensation parameter is set to 0.2, which is used to determine the positive correlation ratio between the first cutting speed and the initial cutting speed.

[0078] The number of inflection points of the focus path is measured by an imaging device;

[0079] Case 1: The number of inflection points along the focus path is 0.

[0080] The first cutting speed is 10 cm / s×(1+0.2)=12 cm / s.

[0081] Case 2: The number of inflection points along the focus path is 3, and the first cutting speed is 10 cm / s×[1+(5-3) / 5]=14 cm / s.

[0082] Case 3: The number of inflection points along the focus path is between 5 and 10. As long as this condition is met, the first cutting speed is equal to the initial cutting speed of 10 cm / s.

[0083] Case 4: The number of inflection points along the focus path is 12, and the first cutting speed is 10 cm / s×[1-(12-10) / 12]=8.3 cm / s.

[0084] The focus path of the workpiece to be processed is acquired through the imaging positioning device, and the number of inflection points on the focus path is judged based on the focus path. The initial cutting speed of the laser cutting device is adjusted according to the number of inflection points of the processing path of the workpiece to obtain a first cutting speed. This can avoid the initial cutting speed of the laser cutting device being too fast due to too many inflection points on the processing path, thereby affecting the processing accuracy and ensuring the quality of the processed workpiece. When there is no inflection point on the focus path, that is, the focus path is a straight line, the initial cutting speed of the laser cutting device is adjusted according to the smoke concentration data collected by the smoke measuring device. When the smoke concentration is high, the initial cutting speed of the laser cutting device is slowed down to avoid excessive smoke concentration affecting the operator's health and causing environmental pollution. When the smoke concentration is low, the initial cutting speed of the laser cutting device is appropriately accelerated to ensure processing efficiency and reduce raw material loss.

[0085] Specifically, based on the first cutting speed, the first cutting speed of the laser cutting device is adjusted according to the inflection point angle to obtain a target cutting speed.

[0086] The data processing module obtains the inflection point angle on the focus path by processing the workpiece surface processing graphics, the first inflection point angle G1 of the processing path, the second inflection point angle G2 of the processing path, ..., the nth inflection point angle Gn of the processing path, and selects any inflection point angle Gi, i = 1, 2, 3, ..., n,

[0087] Determine a target cutting speed of the laser cutting device passing through any inflection point angle according to the initial cutting speed and any inflection point angle, wherein the target cutting speed of the laser cutting device passing through any inflection point angle is positively correlated with the initial cutting speed; the target cutting speed of the laser cutting device passing through any inflection point angle is negatively correlated with the inflection point angle, and the negative correlation ratio between the target cutting speed of the laser cutting device passing through any inflection point angle and the inflection point angle is determined by a preset ratio influence compensation parameter;

[0088] According to the historical inflection point angle data, set the first standard inflection point angle absolute value and the second standard inflection point angle absolute value.

[0089] For a case where the absolute value of any inflection point angle is greater than zero and less than the absolute value of the second standard inflection point angle, a compensation parameter for the influence of the absolute value of any inflection point angle on the target cutting speed of the laser cutting device passing through any inflection point angle is reduced according to the difference between the absolute value of any inflection point angle and the absolute value of the first standard inflection point angle and the absolute value of the second standard inflection point angle;

[0090] For example:

[0091] When the absolute value of any inflection point angle is greater than zero and less than the absolute value of the first standard inflection point angle, the compensation parameter of the influence of the absolute value of any inflection point angle on the target cutting speed of the laser cutting device passing through any inflection point angle is 0.5, wherein the compensation parameter of the influence of the absolute value of any inflection point angle on the target cutting speed of the laser cutting device passing through any inflection point angle before adjustment is 1;

[0092] When the absolute value of any inflection point angle is greater than or equal to the absolute value of the first standard inflection point angle and less than or equal to the absolute value of the first standard inflection point angle, the compensation parameter for the influence of the absolute value of any inflection point angle on the target cutting speed of the laser cutting device passing through any inflection point angle is 0.7;

[0093] When the absolute value of any inflection point angle is greater than the absolute value of the second standard inflection point angle, the compensation parameter for the influence of the absolute value of any inflection point angle on the target cutting speed of the laser cutting device passing through any inflection point angle is 0.9.

[0094] Based on the first cutting speed of the laser cutting device, the first cutting speed of the laser cutting device is adjusted according to the inflection point angle to obtain the target cutting speed. By adjusting the inflection point angle in real time, the first cutting speed can be adjusted to avoid the inflection point angle being too small, the first cutting speed of the laser cutting device is too fast, and the workpiece cannot be precisely processed, which affects the quality of the workpiece. To ensure the quality of the workpiece, when the absolute value of the inflection point angle is greater than zero and less than the absolute value of the first standard inflection point angle, the compensation parameter of the influence of the first inflection point angle on the cutting speed is selected as the compensation parameter of the influence of any inflection point angle on the target cutting speed of the laser cutting device through any inflection point angle. It can be ensured that when any inflection point angle is large, through any inflection point angle A small reduction in the cutting speed of a laser cutting device with an inflection point angle can improve the processing efficiency while ensuring the accuracy of the workpiece being processed; when the absolute value of the inflection point angle is greater than or equal to the absolute value of the second standard inflection point angle is less than or equal to 180°, the compensation parameter for the influence of the third inflection point angle on the cutting speed is selected as the compensation parameter for the influence of any inflection point angle on the target cutting speed of the laser cutting device at any inflection point angle, to avoid cutting according to the initial cutting speed of the laser cutting device after the first adjustment when the absolute value of the inflection point angle is too large, resulting in insufficient processing accuracy of the workpiece; to ensure that the cutting speed of the cutting device at any inflection point can meet the processing accuracy requirements of the workpiece.

[0095] Specifically, the smoke concentration detection device detects the smoke generated in the first cutting stage and the second cutting stage respectively to obtain the smoke concentration, and the process of dividing the detection method into a laser cutting average smoke concentration detection method and a spatial average smoke concentration detection method according to the smoke concentration includes:

[0096] The smoke concentration generated during each cutting is detected by a smoke concentration detection device, and the average smoke concentration of laser cutting is obtained based on the detection result and the cutting time of each laser cutting device.

[0097] The number of processing times of the laser cutting device is determined according to the processing thickness of the workpiece and the initial power of the laser cutting device, wherein the number of processing times of the laser cutting device is positively correlated with the processing thickness of the workpiece and the initial power of the laser cutting device, respectively, and the positive correlation ratio between the number of processing times of the laser cutting device and the processing thickness of the workpiece is determined by a preset proportional influence compensation parameter; the positive correlation ratio between the number of processing times of the laser cutting device and the initial power of the laser cutting device is determined by a preset proportional influence compensation parameter.

[0098] The smoke concentration detection device detects the smoke concentration of smoke generated when the workpiece is cut. The smoke concentration generated by the first cutting is Yn1, the smoke concentration generated by the second cutting is Yn2, ..., the smoke concentration generated by the nth cutting is Ynn,

[0099] The smoke concentration detection device records each cutting time, the first cutting time is Ta1, the second cutting time is Ta2, ..., the nth cutting time is Tan,

[0100] The average smoke density of laser cutting is determined based on the average smoke density of n cutting times.

[0101] The number of processing times of the laser cutting device can be estimated by the processing thickness of the workpiece and the initial power of the cutting device. The power of the laser cutting device and the smoke concentration can be adjusted according to the estimated results. If the processing thickness of the workpiece is too thick, the corresponding processing times of the laser cutting device will increase, resulting in an increase in the smoke concentration. If the initial power is too high, the smoke generated when cutting the workpiece will increase, so the smoke concentration can be estimated.

[0102] Specifically, the process of obtaining the smoke coverage range through the infrared imaging device, determining the safe area according to the smoke coverage range and the average smoke coverage range concentration of the laser cutting, and adjusting the cutting power of the laser cutting device according to the spatial average smoke concentration in the safe area includes:

[0103] Smoke temperature data is collected to generate a smoke coverage range, and the average smoke concentration coverage range of laser cutting is obtained according to the average smoke concentration of laser cutting. The overlapping range of the smoke coverage range and the average smoke concentration coverage range of laser cutting is a safe area.

[0104] The smoke coverage range is generated by collecting smoke temperature data through an infrared imaging device. The smoke coverage range is centered on the workpiece and spreads to the surrounding areas. The temperature at the center is the highest, and the temperature decreases as it moves toward the surrounding areas. The center temperature is the highest due to the high-concentration smoke generated when cutting the workpiece. The smoke temperature data is collected to generate the smoke coverage range. The average smoke concentration coverage range of laser cutting is obtained based on the average smoke concentration of laser cutting. The overlapping range of the smoke coverage range and the average smoke concentration coverage range of laser cutting is the safe area.

[0105] The smoke temperature is determined according to the average smoke concentration of laser cutting, wherein the average smoke concentration of laser cutting is positively correlated with the smoke concentration, and the positive correlation ratio between the average smoke concentration of laser cutting and the smoke concentration is determined by a preset proportional influence compensation parameter.

[0106] The smoke coverage range is generated by collecting smoke temperature data through infrared imaging devices. The smoke coverage range distinguishes the smoke concentration by the distance between different temperature zones and the center point. The closer to the center point, the higher the smoke concentration. The safe area is determined by the range circled by the average smoke concentration of laser cutting in the smoke coverage range. The working range of the operator can be determined according to the affected range near the center point. The power of the laser cutting device and the auxiliary gas flow rate are adjusted during the cutting process through the smoke concentration value within the safe area to achieve the purpose of controlling the smoke concentration to a safe concentration and protect the health of the operator.

[0107] Specifically, the security area includes:

[0108] A first safety zone, wherein the origin of the first safety zone is centered on the workpiece, the laser cutting direction is the positive diffusion direction, and the zone is determined by the auxiliary gas flow rate;

[0109] The second safety zone, the origin of the second safety zone is centered on the workpiece, the positive diffusion direction is the opposite direction of laser cutting, and the area is determined by the auxiliary gas flow rate.

[0110] The first safety area is the area where laser cutting operations are performed, and the area is an irregular sector-shaped area with the workpiece as the center and extending to both sides. The second safety area is the opposite area where laser cutting operations are performed. The smoke concentration requirement in the first safety area is higher than that in the second safety area. When the smoke concentration collected by the smoke detection device in the first safety area is high, it means that the initial power of the cutting device is too large or the auxiliary gas flow rate is too fast, which leads to excessive smoke concentration in the first safety area. At this time, the initial power of the cutting device is adjusted to avoid excessive smoke concentration in the first safety area due to excessive initial power, so as to ensure that the smoke concentration in the first safety area is within the set standard smoke concentration.

[0111] Specifically, the smoke detection device is used to measure the spatial average smoke concentration of the smoke concentration in the first safety area, and the power of the laser cutting device is adjusted according to the comparison result between the measurement result and the set spatial average smoke concentration safety value.

[0112] The smoke detection device measures the spatial average smoke concentration of the first safety area by dividing the first safety area into a first spatial safety area Ka1, a second spatial safety area Ka2, a third spatial safety area Ka3, ..., an nth spatial safety area Kan,

[0113] The smoke detection device measures the spatial average smoke concentration of the smoke concentration in the first spatial safety area Ka1, and the measurement result is Dk1. The smoke concentration in the second spatial safety area Ka2 is measured by the spatial average smoke concentration, and the measurement result is Dk2. The smoke concentration in the third spatial safety area Ka3 is measured by the spatial average smoke concentration, and the measurement result is Dk3,..., the smoke concentration in the first spatial safety area Ka1 is measured by the spatial average smoke concentration, and the measurement result is Dkn,

[0114] Determine the average smoke density of the first safety area according to the average smoke density of n safety areas, set the first safety value of the first safety area's average smoke density and the second safety value of the first safety area's average smoke density.

[0115] When the average smoke density in the first safety area is less than the first safety value of the average smoke density in the first safety area, the first initial power is determined according to the initial power and the difference between the first safety value of the average smoke density in the first safety area and the average smoke density in the first safety area.

[0116] Among them, the first initial power is positively correlated with the initial power; the first initial power is positively correlated with the difference between the first safety value and the average smoke density in the first safety area space and the average smoke density in the first safety area space; the positive correlation ratio between the first initial power and the first safety value and the average smoke density in the first safety area space and the average smoke density in the first safety area space is determined by a preset proportional impact compensation parameter;

[0117] When the average smoke concentration in the first safety zone is greater than or equal to the first safety value of the average smoke concentration in the first safety zone and less than or equal to the second safety value of the average smoke concentration in the first safety zone, the initial power of the laser cutting device is selected to process the workpiece;

[0118] When the average smoke density in the first safety area is greater than the second safety value of the average smoke density in the second safety area, the first initial power is determined according to the initial power and the difference between the average smoke density in the first safety area and the second safety value of the average smoke density in the first safety area.

[0119] Among them, the first initial power is positively correlated with the initial power; the first initial power is negatively correlated with the difference between the average smoke concentration in the first safety area space and the second safety value of the average smoke concentration in the first safety area space; the negative correlation ratio of the first initial power and the difference between the average smoke concentration in the first safety area space and the second safety value of the average smoke concentration in the first safety area space is determined by a preset proportional impact compensation parameter.

[0120] The spatial average smoke concentration of the smoke concentration in the first safety area is measured, and the power of the laser cutting device is adjusted by comparing whether the spatial average smoke concentration is within the safety value range of the spatial average smoke concentration in the first safety area. When the spatial average smoke concentration in the first safety area is less than the first safety value of the spatial average smoke concentration in the first safety area, the initial power of the laser cutting device is increased to the first initial power of the laser cutting device according to the difference between the first safety value of the spatial average smoke concentration in the first safety area and the spatial average smoke concentration in the first safety area, so as to ensure the cutting efficiency of the workpiece to be processed, and avoid the laser cutting device power being too low, resulting in too slow cutting speed of the workpiece to affect the cutting efficiency; when the spatial average smoke concentration in the first safety area is greater than When the first safety value is equal to or less than the average smoke concentration in the first safety area and is equal to or less than the second safety value of the average smoke concentration in the first safety area, the initial power of the laser cutting device is selected to process the workpiece, which can ensure the efficiency of processing the workpiece; when the average smoke concentration in the first safety area is greater than the second safety value of the average smoke concentration in the first safety area, the initial power of the laser cutting device is reduced to the second initial power of the laser cutting device according to the difference between the average smoke concentration in the first safety area and the first safety value of the average smoke concentration in the first safety area, which can avoid the average smoke concentration in the first safety area being too high, which affects the health of the operator, affects the operator's line of sight, and further affects the processing accuracy of the workpiece.

[0121] Specifically, based on the situation that the power of the laser cutting device is adjusted to not meet the smoke concentration in the first safety area, the auxiliary gas flow rate of the laser cutting device is adjusted.

[0122] Setting the minimum power of the laser cutting device according to the type of workpiece to be processed, wherein the types of workpieces to be processed include but are not limited to wood, metal materials, organic materials and composite materials. This embodiment does not limit the specific types of materials of the workpieces to be processed;

[0123] In the case where the minimum power of the laser cutting device is greater than the adjusted first initial power of the laser cutting device, the minimum power of the laser cutting device is selected as the cutting power of the laser cutting device for processing and the auxiliary gas flow rate is adjusted at the same time. The auxiliary gas is used to blow away the smoke particles generated during the laser cutting device cutting the workpiece.

[0124] Since harmful gases are generated during cutting, the initial auxiliary gas flow rate is set according to the initial cutting speed.

[0125] The auxiliary gas flow rate after the first adjustment is determined according to the initial auxiliary gas flow rate and the difference between the first initial power of the laser cutting device and the minimum power of the cutting device, wherein the auxiliary gas flow rate after the first adjustment is positively correlated with the initial auxiliary gas flow rate; the auxiliary gas flow rate after the first adjustment is positively correlated with the difference between the first initial power of the laser cutting device and the minimum power of the cutting device; the positive correlation ratio between the auxiliary gas flow rate after the first adjustment and the difference between the first initial power of the laser cutting device and the minimum power of the cutting device is determined by a preset proportional influence compensation parameter;

[0126] This embodiment also provides a smoke concentration detection system for laser cutting applicable to the smoke concentration detection method for laser cutting, comprising:

[0127] An image processing module is used to perform image forming on the surface image of the processed workpiece;

[0128] Positioning module, used for focus positioning of laser cutting device;

[0129] A control module, used for controlling the image processing module and the positioning module;

[0130] The data processing module is connected to the image processing module, the positioning module and the control module, and is used to process the data collected by each module and control the operation process of each module through the control module.

[0131] This embodiment also provides a smoke concentration detection device for laser cutting applicable to a smoke concentration detection method and system for laser cutting, including:

[0132] A first transmission rod 1, which is connected to the support column 12 and is used for horizontal movement and can be extended or retracted in length according to a preset position;

[0133] A second transmission rod 2, which is connected to the first transmission rod via a second rotating shaft 4 and is used for telescopic movement in a direction perpendicular to the cutting and placing table 8;

[0134] A first rotating shaft 3, which is located inside the first transmission rod 1 and is used for the first transmission rod to move in a horizontal direction;

[0135] A laser cutter 2, connected to the second transmission rod, for cutting and processing a workpiece;

[0136] The jet device 7 is connected to the support column and is used to blow away the smoke generated during the cutting process.

[0137] An imaging device 6, which is connected to the first transmission rod and is used to perform surface imaging on the workpiece, and whose front portion is a metal hose;

[0138] A smoke concentration detection device 5, which is connected to the support column and is used to detect the smoke concentration generated during the cutting process;

[0139] A sliding rod 9, which is connected to the cutting and placing table and is used to fix the valve and the workpiece for processing;

[0140] A first fixed valve 10, which is connected to the sliding rod and is used to fix one end of the workpiece;

[0141] The second fixed valve 11 is connected to the sliding rod and is used to fix the other end of the workpiece.

[0142] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

[0143] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A smoke concentration detection method for laser cutting, characterized in that: The following steps are included: The processing workpiece is imaged by an imaging device to obtain an image of the workpiece, and the positioning module determines a focal point passing path according to the image of the workpiece; Analyzing the number of inflection points and the inflection point angles in the path through which the focus passes, and determining a target cutting speed according to the number of inflection points and the inflection point angles; Obtaining the thickness of the workpiece to be processed, determining the initial power of the laser cutting device according to the thickness of the workpiece to be processed, and determining the number of cutting times of the laser cutting device according to the initial power of the laser cutting device; The smoke generated in the first cutting stage and the second cutting stage are respectively detected by a smoke concentration detection device to obtain the smoke concentration. According to the smoke concentration, the detection method is divided into a laser cutting average smoke concentration detection method and a spatial average smoke concentration detection method; The smoke coverage is obtained by an infrared imaging device, a safe area is determined according to the smoke coverage and the average smoke coverage density of laser cutting, and the cutting power of the laser cutting device is adjusted according to the average smoke density in the safety area.

2. The smoke concentration detection method for laser cutting according to claim 1, characterized in that: The imaging device is used to image the workpiece to obtain an image of the workpiece, and the positioning module determines the focus path according to the image of the workpiece, including: The marking points on the surface of the workpiece are positioned by an imaging device, and the laser cutting device determines the focal point passing path according to the focal point position collected by the positioning module.

3. The smoke concentration detection method for laser cutting according to claim 2, characterized in that: The imaging device is used to image the workpiece to obtain an image of the workpiece, and the positioning module determines the focus path according to the image of the workpiece, including: The initial cutting speed of the laser cutting device is adjusted by the number of inflection points in the focus passing path to obtain a first cutting speed.

4. The smoke concentration detection method for laser cutting according to claim 3 is characterized in that: Based on the first cutting speed, the first cutting speed of the laser cutting device is adjusted according to the inflection point angle to obtain a target cutting speed.

5. The smoke concentration detection method for laser cutting according to claim 4, characterized in that: The smoke concentration detection device is used to detect the smoke generated in the first cutting stage and the second cutting stage respectively to obtain the smoke concentration, and the detection method is divided into a laser cutting average smoke concentration detection method and a spatial average smoke concentration detection method according to the smoke concentration. The process includes: The smoke concentration generated during each cutting is detected by a smoke concentration detection device, and the average smoke concentration of laser cutting is obtained based on the detection result and the cutting time of each laser cutting device.

6. The smoke concentration detection method for laser cutting according to claim 5, characterized in that: The process of obtaining the smoke coverage range through the infrared imaging device, determining the safe area according to the smoke coverage range and the average smoke coverage range concentration of the laser cutting, and adjusting the cutting power of the laser cutting device according to the spatial average smoke concentration in the safe area includes: Smoke temperature data is collected to generate a smoke coverage range, and the average smoke concentration coverage range of laser cutting is obtained according to the average smoke concentration of laser cutting. The overlapping range of the smoke coverage range and the average smoke concentration coverage range of laser cutting is a safe area.

7. The smoke concentration detection method for laser cutting according to claim 6, characterized in that: The security area includes: A first safety zone, wherein the origin of the first safety zone is centered on the workpiece, the laser cutting direction is the positive diffusion direction, and the zone is determined by the auxiliary gas flow rate; The second safety zone, the origin of the second safety zone is centered on the workpiece, the positive diffusion direction is the opposite direction of laser cutting, and the area is determined by the auxiliary gas flow rate.

8. The smoke concentration detection method for laser cutting according to claim 7, characterized in that: The smoke concentration in the first safety area is measured by a smoke detection device for a spatial average smoke concentration, and the power of the laser cutting device is adjusted according to a comparison result between the measurement result and a set spatial average smoke concentration safety value.

9. The smoke concentration detection method for laser cutting according to claim 8, characterized in that: Based on the situation that the power of the laser cutting device is adjusted to not meet the smoke concentration in the first safety area, the auxiliary gas flow rate of the laser cutting device is adjusted.

10. A smoke concentration detection system for laser cutting, using the smoke concentration detection method for laser cutting according to any one of claims 1 to 9, characterized in that: include, An image processing module is used to perform image forming on the surface image of the processed workpiece; Positioning module, used for focus positioning of laser cutting device; A control module, used for controlling the image processing module and the positioning module; The data processing module is connected to the image processing module, the positioning module and the control module, and is used to process the data collected by each module and control the operation process of each module through the control module.

Images