A Smoke Concentration Detection Method and System for Laser Cutting

Abstract

The present invention relates to the technical field of smoke concentration detection, and discloses a smoke concentration detection method and system for laser cutting. The method includes: obtaining an imaging image of a workpiece, and determining a focus passing path according to the imaging image of the workpiece; analyzing the number and angles of inflection points in the passing path to determine a target cutting speed; obtaining the thickness of the machined workpiece to determine an initial power, and determining the number of cutting times according to the initial power; detecting the smoke generated in the first cutting stage and the second cutting stage to obtain a smoke concentration, and classifying the detection method into an average smoke concentration detection method for laser cutting and a spatial average smoke concentration detection method according to the smoke concentration; obtaining a smoke coverage range and an average smoke concentration coverage range for laser cutting to determine a safe area. The present invention reduces the impact of the smoke concentration in the safe area on the health of operators by adjusting the parameters during the laser cutting process and the smoke concentration in the safe area.

Description

Technical Field

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

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

[0003] Chinese Patent Publication No.: CN118010576A, discloses a method for detecting the particle size and concentration of smoke, including the following steps: S1. Smoke passes through the filter screens (5) arranged on both sides of the sample cell (4) for filtering along with the smoke particles, and as the smoke particle target (6) passes through the filter screen (5) and enters the interior of the sample cell (4); S2. An infrared ray (101) is emitted from the output end of the infrared laser emitter (1), and a blue ray (201) is emitted from the output end of the blue laser emitter (2). At this time, the infrared ray (101) and the blue ray (201) are alternately emitted at a high frequency towards the smoke particle target (6) entering the interior of the transparent sample cell (4); S3. The infrared ray (101) and the blue ray (201) are scattered towards the linear array CCD sensor (3) along with the smoke particle target (6). Different particles in the smoke particle target (6) cause the infrared ray (101) and the blue ray (201) to emit light beams at different angles inside the linear array CCD sensor (3); S4. As the smoke particle concentration increases, the scattering intensity of the infrared ray (101) and the blue ray (201) increases synchronously, making the sensitivity of the corresponding effective pixel area of the linear array CCD sensor (3) larger. The conversion of the optical signal sensed in the effective pixel area into an electrical signal outputs the corresponding position information. Technicians judge the concentration of a certain kind of particle in the sample cell (4) according to the magnitude of the signal response value, and then estimate the degree of current battery thermal runaway to take corresponding control measures.

[0004] It can be seen from this that the existing technology has the following problems: Due to the lack of adjusting the parameters during the laser cutting process and the smoke concentration in the safe area, the smoke concentration is too high, which affects the physical health of the operators. Summary of the Invention

[0005] Therefore, the present invention provides a method and system for detecting smoke concentration for laser cutting to overcome the problem in the existing technology that due to the lack of adjusting the parameters during the laser cutting process and the smoke concentration in the safe area, the smoke concentration is too high, which affects the physical health of the operators.

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

[0007] The imaging device is used to image the workpiece to be processed to obtain the workpiece imaging image, and the positioning module determines the focus passing path according to the workpiece imaging image;

[0008] Analyze the number of inflection points and the inflection angles within the focus passing path, and determine the target cutting speed according to the number of inflection points and the inflection angles;

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

[0010] The smoke concentration detection device is used to detect the concentration of the smoke generated in the first cutting stage and the second cutting stage respectively to obtain the smoke concentration, and classify the detection methods into the laser cutting average smoke concentration detection method and the spatial average smoke concentration detection method according to the smoke concentration;

[0011] The infrared imaging device is used to obtain the smoke coverage range, determine the safe area according to the smoke coverage range and the laser cutting average smoke coverage range concentration, and adjust the cutting power of the laser cutting device according to the spatial average smoke concentration within the safe area;

[0012] The imaging device is used to locate the marking points on the surface of the workpiece to be processed, and the laser cutting device determines the focus passing path according to the focus position collected by the positioning module;

[0013] Adjust the initial cutting speed of the laser cutting device through the number of inflection points within the focus passing path to obtain the first cutting speed;

[0014] Based on the first cutting speed, adjust the first cutting speed of the laser cutting device according to the inflection angle to obtain the target cutting speed;

[0015] Collect the smoke temperature data to generate the smoke coverage range, obtain the laser cutting average smoke concentration coverage range according to the laser cutting average smoke concentration, and the overlapping range of the smoke coverage range and the laser cutting average smoke concentration coverage range is the safe area;

[0016] The smoke detection device is used to measure the spatial average smoke concentration of the smoke in the first safe area, and adjust the power of the laser cutting device according to the comparison result between the measurement result and the set spatial average smoke concentration safety value.

[0017] Further, the process of using the smoke concentration detection device to detect the concentration of the smoke generated in the first cutting stage and the second cutting stage respectively to obtain the smoke concentration, and classifying the detection methods into the laser cutting average smoke concentration detection method and the spatial average smoke concentration detection method 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 according to the detection result and the cutting time of the laser cutting device each time.

[0019] Further, the safety area includes;

[0020] The first safety area, the origin of the first safety area is centered on the workpiece to be processed, and the positive diffusion direction is the laser cutting direction, and the area determined by the auxiliary gas flow rate;

[0021] The second safety area, the origin of the second safety area is centered on the workpiece to be processed, and the positive diffusion direction is the reverse direction of laser cutting, and the area determined by the auxiliary gas flow rate.

[0022] Further, based on the situation that adjusting the power of the laser cutting device does not meet the smoke concentration in the first safety area, the auxiliary gas flow rate of the laser cutting device is adjusted.

[0023] The present invention also provides a smoke concentration detection system for laser cutting, which is applicable to a smoke concentration detection method for laser cutting, including,

[0024] An image processing module for image forming of the surface image of the workpiece to be processed;

[0025] A positioning module for focusing the laser cutting device;

[0026] A control module for controlling the image processing module and the positioning module;

[0027] A data processing module, which is connected to the image processing module, the positioning module, and the control module, and is used for processing the data collected by each module and controlling the operation process of each module through the control module.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows: the imaging and positioning device is used to obtain the focus passing path of the workpiece to be processed, the number of upper inflection points thereon is judged based on the focus passing 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 situation that the initial cutting speed of the laser cutting device is too fast due to too many inflection points on the processing path, affecting the processing accuracy and ensuring the quality of the workpiece to be processed. When there are no inflection points on the focus passing path, that is, the focus passing 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 body and causing environmental pollution. When the smoke concentration is low, the initial cutting speed of the laser cutting device is appropriately increased to ensure the processing efficiency and reduce the raw material loss.

[0029] Further, 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. Adjusting the first cutting speed in real time through the inflection point angle can avoid the situation that when the inflection point angle is too small, the first cutting speed of the laser cutting device is too fast, and the workpiece to be processed cannot be precisely processed, affecting the quality of the workpiece to be processed and ensuring the quality of the workpiece to be processed. 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 influence compensation parameter of the first inflection point angle on the cutting speed is selected as the influence compensation parameter of any inflection point angle on the target cutting speed of the laser cutting device passing through any inflection point angle, which can ensure that when any inflection point angle is large, a small decrease in the cutting speed of the laser cutting device passing through any inflection point angle can meet the requirement of improving the processing efficiency under the condition of ensuring the processing accuracy of the workpiece to be 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 and less than or equal to 180°, the influence compensation parameter of the third inflection point angle on the cutting speed is selected as the influence compensation parameter of any inflection point angle on the target cutting speed of the laser cutting device passing through any inflection point angle, avoiding the situation that when the absolute value of the inflection point angle is too large, cutting is performed according to the initial cutting speed of the laser cutting device after the first adjustment, resulting in insufficient processing accuracy of the workpiece to be processed; ensuring that the cutting speed of the cutting device at any inflection point can meet the processing accuracy requirements of the workpiece to be processed.

[0030] Further, the number of processing times of the laser cutting device is estimated by the processing thickness of the workpiece to be processed and the initial power of the cutting device, and the adjustment of the power of the laser cutting device and the smoke concentration can be estimated according to the estimation result. If the processing thickness of the workpiece to be processed is too thick, the number of processing times of the corresponding laser cutting device increases, resulting in an increase in the smoke concentration. If the initial power is too high, the smoke generated during the cutting of the workpiece to be processed will increase, so that the generated smoke concentration can be estimated.

[0031] Further, a smoke coverage range is generated from the data collected on the smoke temperature by an infrared imaging device. The smoke coverage range differentiates the smoke concentration based on the distances from different temperature zones to the center point. The closer to the center point, the higher the smoke concentration. The safe area is determined by the range delineated by the average smoke concentration cut by laser 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 flow rate of the auxiliary gas during the cutting process are adjusted according to the smoke concentration values within the safe area range, so as to control the smoke concentration to a safe concentration and protect the physical health of the operator.

[0032] Further, the first safe area is the area where laser cutting operations are carried out. The area is an irregular fan shape extending from both sides with the processed workpiece as the center. The second safe area is the area opposite to the area where laser cutting operations are carried out. The requirement for the smoke concentration in the first safe area is higher than that in the second safe area. When the smoke concentration collected by the smoke detection device in the first safe area is relatively high, it indicates that the initial power of the cutting device is too high or the flow rate of the auxiliary gas is too fast, resulting in too high a smoke concentration in the first safe area. At this time, the initial power of the cutting device is adjusted to avoid too high a smoke concentration in the first safe area due to excessive initial power and ensure that the smoke concentration in the first safe area is within the set standard smoke concentration.

[0033] Further, spatial average smoke concentration measurement is performed on the smoke concentration in the first safe area. The power of the laser cutting device is adjusted by comparing whether the spatial average smoke concentration is within the safe value range of the spatial average smoke concentration in the first safe area. When the spatial average smoke concentration in the first safe area is less than the first safe value of the spatial average smoke concentration in the first safe 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 safe value of the spatial average smoke concentration in the first safe area and the spatial average smoke concentration in the first safe area, which can ensure the cutting efficiency of the processed workpiece and avoid too slow a cutting speed of the processed workpiece due to too low a power of the laser cutting device, affecting the cutting efficiency. When the spatial average smoke concentration in the first safe area is greater than or equal to less than the first safe value of the spatial average smoke concentration in the first safe area and less than or equal to less than the second safe value of the spatial average smoke concentration in the first safe area, the initial power of the laser cutting device is selected to process the processed workpiece, which can ensure the efficiency of the processed workpiece. When the spatial average smoke concentration in the first safe area is greater than the second safe value of the spatial average smoke concentration in the first safe area, the initial power of the laser cutting device is decreased to the second initial power of the laser cutting device according to the difference between the spatial average smoke concentration in the first safe area and the first safe value of the spatial average smoke concentration in the first safe area, which can avoid too high a spatial average smoke concentration in the first safe area from affecting the health of the operator and the operator's line of sight, and further affecting the processing accuracy of the processed workpiece. Description of the Drawings

[0034] Figure 1 It is a flowchart of the smoke concentration detection method for laser cutting in this embodiment;

[0035] Figure 2 It is a flowchart of the process of obtaining the target cutting speed of the smoke concentration detection method for laser cutting in this embodiment;

[0036] Figure 3 It is a system operation flowchart of the smoke concentration detection system for laser cutting applicable to the smoke concentration detection method for laser cutting in this embodiment;

[0037] Figure 4 It is a schematic diagram of the device structure applicable to the smoke concentration detection method and system for laser cutting in this embodiment.

[0038] Figure 4 in;

[0039] 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 Embodiment

[0040] In order to make the objectives and advantages of the present invention clearer and more understandable, the present invention will be 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.

[0041] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention and do not limit the protection scope of the present invention.

[0042] It should be noted that in the description of the present invention, the terms indicating directions or positional relationships such as "upper", "lower", "left", "right", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings. This is only for 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, and therefore should not be construed as a limitation of the present invention.

[0043] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" 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 an indirect connection through an intermediate medium, and it can be the communication inside 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.

[0044] Please refer to Figures 1-4 as shown in Figure 1 the flowchart of the smoke concentration detection method for laser cutting in this embodiment; Figure 2 the flowchart of the process of obtaining the target cutting speed of the smoke concentration detection method for laser cutting in this embodiment; Figure 3 the system operation flowchart of the smoke concentration detection system for laser cutting applicable to the smoke concentration detection method for laser cutting in this embodiment; Figure 4 the schematic diagram of the device structure applicable to the smoke concentration detection method and system for laser cutting in this embodiment.

[0045] This embodiment provides a smoke concentration detection method for laser cutting, including the following steps

[0046] Step S1: Image the workpiece to be processed through an imaging device to obtain a workpiece imaging image, and the positioning module determines the focus passing path according to the workpiece imaging image;

[0047] Step S2: Analyze the number of inflection points and the inflection angles within the focus passing path, and determine the target cutting speed according to the number of inflection points and the inflection angles;

[0048] Step S3: Obtain the thickness of the workpiece to be processed, determine the initial power of the laser cutting device according to the thickness of the workpiece to be processed, and determine the cutting times of the laser cutting device according to the initial power of the laser cutting device;

[0049] Step S4: Detect the concentrations of the smoke generated in the first cutting stage and the second cutting stage respectively through a smoke concentration detection device to obtain the smoke concentration, and classify the detection methods into the average smoke concentration detection method for laser cutting and the spatial average smoke concentration detection method according to the smoke concentration;

[0050] Step S5: Obtain the smoke coverage range through an infrared imaging device, determine the safe area according to the smoke coverage range and the average smoke concentration for laser cutting, and adjust the cutting power of the laser cutting device according to the spatial average smoke concentration within the safe area.

[0051] This embodiment provides a process for obtaining the target cutting speed in a method for detecting the smoke concentration for laser cutting, including:

[0052] Step S210: Obtain the focus passing path and the number of inflection points within the passing path;

[0053] Step S220: Adjust the initial cutting speed of the laser cutting device according to the number of inflection points to obtain the first cutting speed;

[0054] Step S230: Based on the first cutting speed, obtain the inflection point angle;

[0055] Step S240: Adjust the first cutting speed according to the inflection point angle to obtain the target cutting speed.

[0056] Specifically, the process of imaging the workpiece to be processed by the imaging device to obtain the workpiece imaging image, and the positioning module determining the focus passing path according to the workpiece imaging image includes:

[0057] Locate the marked points on the surface of the workpiece to be processed by the imaging device, and the laser cutting device determines the focus passing path according to the focus position collected by the positioning module.

[0058] The imaging device is arranged inside the processing component, above the workpiece to be processed. By collecting the image data of the workpiece to be processed, a processing pattern on the surface of the workpiece to be processed is generated, and the focus passing path of the processing pattern on the surface of the workpiece to be processed is determined by the positioning module.

[0059] Specifically, the process of imaging the workpiece to be processed by the imaging device to obtain the workpiece imaging image, and the positioning module determining the focus passing path according to the workpiece imaging image includes:

[0060] Adjust the initial cutting speed of the laser cutting device according to the number of inflection points within the focus passing path to obtain the first cutting speed.

[0061] Obtain the initial cutting speed according to the historical processing data,

[0062] Determine the first cutting speed in different cases according to the number of inflection points of the focus passing path and the initial cutting speed,

[0063] For the case where the number of inflection points of the focus passing path is equal to zero, determine the first cutting speed according to the initial cutting speed. The first cutting speed is positively correlated with the initial cutting speed, and the first cutting speed is positively correlated with the initial cutting speed;

[0064] Among them, the positive correlation ratio between the first cutting speed and the initial cutting speed is determined by a preset ratio influence compensation parameter;

[0065] The number of inflection points of the focus passing path is measured by the imaging device;

[0066] Set the number of inflection points of the first standard focus passing path and the number of inflection points of the second standard focus passing path, where the number of inflection points of the first standard focus passing path and the number of inflection points of the second standard focus passing path are obtained based on the historical data of the number of inflection points of the focus passing path;

[0067] For the case where the number of inflection points of the focus passing path is greater than zero and less than the number of inflection points of the first standard focus passing path, it is determined according to the product of the ratio of (1 plus 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 and the initial cutting speed,

[0068] Among them, the first cutting speed is positively correlated with the initial cutting speed and 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;

[0069] For 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;

[0070] For the case where the number of inflection points of the focus passing path is greater than the number of inflection points of the second standard focus passing path, it is determined according to the product of the ratio of (1 minus the difference between the number of inflection points of the second standard focus passing path and the number of inflection points of the focus passing path) to the number of inflection points of the second standard focus passing path and the initial cutting speed,

[0071] 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;

[0072] For example:

[0073] The initial cutting speed is 10 cm / s, the number of inflection points of the first standard focus passing path is set to 5, and the number of inflection points of the second standard focus passing path is set to 10;

[0074] The ratio influence 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,

[0075] The number of inflection points of the focus passing path is measured by the imaging device;

[0076] Case 1: The number of inflection points of the focus passing path is 0,

[0077] The first cutting speed 10 cm / s × (1 + 0.2) = 12 cm / s.

[0078] Case 2: The number of inflection points of the focus passing path is 3, and the first cutting speed is 10 cm / s × [1 + (5 - 3) / 5] = 14 cm / s.

[0079] Case 3: The number of inflection points of the focus passing 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.

[0080] Case 4: The number of inflection points of the focus passing path is 12, and the first cutting speed is 10 cm / s × [1 - (12 - 10) / 12] = 8.3 cm / s.

[0081] The imaging positioning device is used to obtain the focus passing path of the workpiece to be processed, judge the number of inflection points on it based on the focus passing path, and adjust the initial cutting speed of the laser cutting device 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 ensure the quality of the workpiece to be processed. When there are no inflection points on the focus passing path, that is, the focus passing 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 body and causing environmental pollution. When the smoke concentration is low, the initial cutting speed of the laser cutting device is appropriately increased to ensure the processing efficiency and reduce the raw material loss.

[0082] 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 the target cutting speed.

[0083] The data processing module obtains the inflection point angles on the focus path through the processing graphics on the surface of the workpiece to be processed, 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, where i = 1, 2, 3,..., n.

[0084] According to the initial cutting speed and any inflection point angle, the target cutting speed of the laser cutting device passing through any inflection point angle is determined. Among them, 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 the preset proportional influence compensation parameter.

[0085] Set the absolute value of the first standard inflection point angle and the absolute value of the second standard inflection point angle according to the historical inflection point angle data.

[0086] For any case where the absolute value of an inflection point angle is greater than zero and less than the absolute value of the second standard inflection point angle, adjust the influence compensation parameter of the absolute value of any inflection point on the target cutting speed of the laser cutting device passing through any inflection point according to the difference between the absolute value of any inflection point angle and the absolute values of the first standard inflection point angle and the second standard inflection point angle;

[0087] For example:

[0088] 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 influence compensation parameter of the absolute value of any inflection point on the target cutting speed of the laser cutting device passing through any inflection point is 0.5, where the influence compensation parameter of the absolute value of any inflection point on the target cutting speed of the laser cutting device passing through any inflection point before adjustment is 1;

[0089] 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 influence compensation parameter of the absolute value of any inflection point on the target cutting speed of the laser cutting device passing through any inflection point is 0.7;

[0090] When the absolute value of any inflection point angle is greater than the absolute value of the second standard inflection point angle, the influence compensation parameter of the absolute value of any inflection point on the target cutting speed of the laser cutting device passing through any inflection point is 0.9.

[0091] Based on the first cutting speed of the laser cutting device, adjust the first cutting speed of the laser cutting device according to the inflection point angle to obtain the target cutting speed. By adjusting the first cutting speed in real time through the inflection point angle, it can be avoided that when the inflection point angle is too small, the first cutting speed of the laser cutting device is too fast, and it is impossible to perform precision machining on the workpiece to be processed, affecting the quality of the workpiece to be processed, and ensuring the quality of the workpiece to be processed. 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, select the influence compensation parameter of the first inflection point angle on the cutting speed as the influence compensation parameter of any inflection point on the target cutting speed of the laser cutting device passing through any inflection point, which 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 can meet the requirement of improving the processing efficiency under the condition of ensuring the machining accuracy of the workpiece to be 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 and less than or equal to 180°, select the influence compensation parameter of the third inflection point angle on the cutting speed as the influence compensation parameter of any inflection point on the target cutting speed of the laser cutting device passing through any inflection point, to avoid insufficient machining accuracy of the workpiece to be processed due to cutting at 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; ensure that the cutting speed of the cutting device at any inflection point can meet the machining accuracy requirements of the workpiece to be processed.

[0092] Specifically, the process of detecting the concentration of the smoke generated in the first cutting stage and the second cutting stage respectively by the smoke concentration detection device to obtain the smoke concentration, and classifying the detection methods into the laser cutting average smoke concentration detection method and the spatial average smoke concentration detection method according to the smoke concentration includes:

[0093] The smoke concentration detection device detects the smoke concentration generated during each cutting, and obtains the laser cutting average smoke concentration according to the detection result and the cutting time of the laser cutting device each time.

[0094] Determine the number of processing times of the laser cutting device according to the processing thickness of the workpiece to be processed and the initial power of the laser cutting device. Among them, the number of processing times of the laser cutting device is positively correlated with the processing thickness of the workpiece to be processed and the initial power of the laser cutting device respectively. The positive correlation ratio between the number of processing times of the laser cutting device and the processing thickness of the workpiece to be processed is determined by a preset ratio 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 ratio influence compensation parameter.

[0095] The smoke concentration detection device detects the smoke concentration generated during the cutting of the workpiece to be processed. The smoke concentration generated during the first cutting is Yn1, the smoke concentration generated during the second cutting is Yn2,..., and the smoke concentration generated during the nth cutting is Ynn.

[0096] The smoke concentration detection device records the cutting time each time. The first cutting time is Ta1, the second cutting time is Ta2,..., and the nth cutting time is Tan.

[0097] Determine the laser cutting average smoke concentration according to the average value of the smoke concentration of n cuts.

[0098] By estimating the number of processing times of the laser cutting device based on the processing thickness of the workpiece to be processed and the initial power of the cutting device, it is possible to estimate the adjustment of the power of the laser cutting device and the smoke concentration according to the estimation result. If the processing thickness of the workpiece to be processed is too thick, the corresponding number of processing times of the laser cutting device increases, resulting in an increase in the smoke concentration. If the initial power is too high, the smoke generated during the cutting of the workpiece to be processed will increase, so that the generated smoke concentration can be estimated.

[0099] Specifically, the process of obtaining the smoke coverage range by the infrared imaging device, determining the safe area according to the smoke coverage range and the laser cutting average smoke coverage range concentration, and adjusting the cutting power of the laser cutting device according to the spatial average smoke concentration in the safe area includes:

[0100] Collect the smoke temperature data to generate the smoke coverage range, and obtain the laser cutting average smoke concentration coverage range according to the laser cutting average smoke concentration. The overlapping range of the smoke coverage range and the laser cutting average smoke concentration coverage range is the safe area.

[0101] Generate the smoke coverage range through the data collected by the infrared imaging device for the smoke temperature. The smoke coverage range spreads around the workpiece to be processed. The temperature at the center position is the highest, and the temperature decreases towards the periphery. The central temperature is the highest because the smoke with a higher concentration is generated during the cutting of the workpiece to be processed. Collect the smoke temperature data to generate the smoke coverage range, and obtain the laser cutting average smoke concentration coverage range according to the laser cutting average smoke concentration. The overlapping range of the smoke coverage range and the laser cutting average smoke concentration coverage range is the safe area.

[0102] Determine the smoke temperature according to the laser cutting average smoke concentration. Among them, the laser cutting average smoke concentration is positively correlated with the smoke concentration, and the positive correlation ratio between the laser cutting average smoke concentration and the smoke concentration is determined by a preset ratio influence compensation parameter.

[0103] Generate the smoke coverage range through the data collected by the infrared imaging device for the smoke temperature. The smoke coverage range differentiates 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. Determine the safe area by the range delineated by the laser cutting average smoke concentration in the smoke coverage range. It is possible to determine the working range of the operator according to the affected range near the center point. Adjust the power of the laser cutting device and the flow rate of the auxiliary gas during the cutting process by the smoke concentration value within the safe area range to achieve the purpose of controlling the smoke concentration to a safe concentration and protecting the physical health of the operator.

[0104] Specifically, the safe area includes

[0105] The first safe area, the origin of the first safe area is centered on the workpiece to be processed, and the positive diffusion direction is the laser cutting direction. The area is determined by the flow rate of the auxiliary gas;

[0106] The second safe area, the origin of the second safe area is centered on the workpiece to be processed, and the positive diffusion direction is the reverse direction of the laser cutting. The area is determined by the flow rate of the auxiliary gas.

[0107] The first safety area is the area where laser cutting operation is carried out. The area is an irregular fan shape extending from both sides with the processed workpiece as the center. The second safety area is the area opposite to the area where laser cutting operation is carried out. The requirement for the smoke concentration 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 relatively high, it indicates that the initial power of the cutting device is too large or the flow rate of the auxiliary gas is too fast, resulting in too high smoke concentration in the first safety area. At this time, the initial power of the cutting device is adjusted to avoid too high smoke concentration in the first safety area due to excessive initial power and ensure that the smoke concentration in the first safety area is within the set standard smoke concentration.

[0108] Specifically, the smoke detection device measures the spatial average smoke concentration in the first safety area, and adjusts the power of the laser cutting device according to the comparison result between the measurement result and the set spatial average smoke concentration safety value.

[0109] The smoke detection device measures the spatial average smoke concentration in the first safety area. The measurement method is to divide the first safety area into the first spatial safety area Ka1, the second spatial safety area Ka2, the third spatial safety area Ka3,..., the nth spatial safety area Kan.

[0110] The smoke detection device measures the spatial average smoke concentration in the first spatial safety area Ka1, and the measurement result is Dk1. It measures the spatial average smoke concentration in the second spatial safety area Ka2, and the measurement result is Dk2. It measures the spatial average smoke concentration in the third spatial safety area Ka3, and the measurement result is Dk3,..., and it measures the spatial average smoke concentration in the nth spatial safety area Kan, and the measurement result is Dkn.

[0111] Determine the spatial average smoke concentration of the first safety area according to the average value of the smoke concentrations in the n spatial safety areas, and set the first safety value and the second safety value of the spatial average smoke concentration of the first safety area.

[0112] For the case where the spatial average smoke concentration of the first safety area is less than the first safety value of the spatial average smoke concentration of the first safety area, determine the first initial power according to the initial power and the difference between the first safety value of the spatial average smoke concentration of the first safety area and the spatial average smoke concentration of the first safety area.

[0113] 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 of the spatially averaged smoke concentration in the first safety area and the spatially averaged smoke concentration in the first safety area; the positive correlation ratio between the first initial power and the difference between the first safety value of the spatially averaged smoke concentration in the first safety area and the spatially averaged smoke concentration in the first safety area is determined by a preset ratio influence compensation parameter;

[0114] For the case where the spatially averaged smoke concentration in the first safety area is greater than or equal to the first safety value of the spatially averaged smoke concentration in the first safety area and less than or equal to the second safety value of the spatially averaged smoke concentration in the first safety area, select the initial power of the laser cutting device to process the workpiece;

[0115] For the case where the spatially averaged smoke concentration in the first safety area is greater than the second safety value of the spatially averaged smoke concentration in the first safety area, determine the first initial power according to the initial power and the difference between the spatially averaged smoke concentration in the first safety area and the second safety value of the spatially averaged smoke concentration in the first safety area,

[0116] 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 spatially averaged smoke concentration in the first safety area and the second safety value of the spatially averaged smoke concentration in the first safety area; the negative correlation ratio between the first initial power and the difference between the spatially averaged smoke concentration in the first safety area and the second safety value of the spatially averaged smoke concentration in the first safety area is determined by a preset ratio influence compensation parameter.

[0117] Perform spatial average smoke concentration measurement on the smoke concentration in the first safety area, and adjust the power of the laser cutting device by comparing whether the spatial average smoke concentration is within the safe 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, which can ensure the cutting efficiency of the workpiece to be processed and avoid the power of the laser cutting device being too low, resulting in too slow cutting speed of the workpiece to be processed and affecting the cutting efficiency. When the spatial average smoke concentration in the first safety area is greater than or equal to less than the first safety value of the spatial average smoke concentration in the first safety area and less than or equal to less than the second safety value of the spatial average smoke concentration in the first safety area, select the initial power of the laser cutting device to process the workpiece to be processed, which can ensure the efficiency of the workpiece to be processed. 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 spatial average smoke concentration in the first safety area being too high, affecting the health of the operator and the operator's line of sight, and further affecting the processing accuracy of the workpiece to be processed.

[0118] Specifically, based on the situation that the power adjustment of the laser cutting device does not meet the smoke concentration in the first safety area, adjust the auxiliary gas flow rate of the laser cutting device.

[0119] Set the minimum power of the laser cutting device according to the type of workpiece to be processed, where the type of workpiece to be processed includes, but is not limited to, wood, metal materials, organic materials, and composite materials. In this embodiment, the specific type of workpiece material is not limited.

[0120] For the case where the minimum power of the laser cutting device is greater than the first initial power of the adjusted laser cutting device, select the minimum power of the laser cutting device as the cutting power of the laser cutting device for processing and adjust the auxiliary gas flow rate at the same time. The auxiliary gas blows away the smoke particles generated during the cutting process of the laser cutting device for processing the workpiece.

[0121] Since harmful gases are generated during cutting, set the initial auxiliary gas flow rate according to the initial cutting speed.

[0122] Determine the auxiliary gas flow rate after the first adjustment 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. Among them, 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;

[0123] This embodiment also provides a smoke concentration detection system for a laser cutting-oriented smoke concentration detection method, including,

[0124] An image processing module for image formation of the surface image of the workpiece to be processed;

[0125] A positioning module for focal point positioning of the laser cutting device;

[0126] A control module for controlling the image processing module and the positioning module;

[0127] A data processing module, which is connected to the image processing module, the positioning module, and the control module, and is used for processing the data collected by each module and controlling the operation process of each module through the control module.

[0128] This embodiment also provides a smoke concentration detection device for a laser cutting-oriented smoke concentration detection method and system, including,

[0129] A first transmission rod 1, which is connected to the support column 12 and is used for horizontal movement and can be extended and retracted in length according to a preset position;

[0130] A second transmission rod 2, which is connected to the first transmission rod through a second rotating shaft 4 and is used for telescopic movement perpendicular to the cutting placement table 8;

[0131] A first rotating shaft 3, which is located inside the first transmission rod 1 and is used for the horizontal movement of the first transmission rod;

[0132] A laser cutter 2, which is connected to the second transmission rod and is used for cutting the workpiece to be processed;

[0133] An air jet device 7, which is connected to the support column and is used for blowing away the smoke generated during the cutting process

[0134] An imaging device 6, which is connected to the first transmission rod and is used for surface imaging of the workpiece to be processed, and its front part is a metal hose;

[0135] The smoke concentration detection device 5 is connected to the support column and is used to detect the smoke concentration generated during the cutting process;

[0136] The sliding rod 9 is connected to the cutting placement table and is used to fix the valve to fix the workpiece;

[0137] The first fixing valve 10 is connected to the sliding rod and is used to fix one end of the workpiece;

[0138] The second fixing valve 11 is connected to the sliding rod and is used to fix the other end of the workpiece.

[0139] So far, the technical solution of the present invention has been described in conjunction with the preferred embodiments shown in the 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 all fall within the protection scope of the present invention.

[0140] The above are only the preferred embodiments of the present invention and are not used to limit the present invention; for those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent substitution, 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 method for detecting the smoke concentration for laser cutting, characterized in that including the following steps, imaging the workpiece to be processed by an imaging device to obtain an image of the workpiece, and a positioning module determining a focus passing path according to the workpiece image; analyzing the number of inflection points and the inflection angles within the focus passing path, and determining a target cutting speed according to the number of inflection points and the inflection 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; detecting the concentrations of the smoke generated in the first cutting stage and the second cutting stage respectively by a smoke concentration detection device to obtain the smoke concentration, and classifying the detection methods into a laser cutting average smoke concentration detection method and a spatial average smoke concentration detection method according to the smoke concentration; obtaining the smoke coverage range by an infrared imaging device, determining a safety area according to the smoke coverage range and the laser cutting average smoke coverage range concentration, and adjusting the cutting power of the laser cutting device according to the spatial average smoke concentration within the safety area; positioning the marking points on the surface of the workpiece to be processed by an imaging device, and the laser cutting device determining a focus passing path according to the focus position collected by the positioning module; adjusting the initial cutting speed of the laser cutting device by the number of inflection points within the focus passing path to obtain a first cutting speed; based on the first cutting speed, adjusting the first cutting speed of the laser cutting device according to the inflection angle to obtain a target cutting speed; collecting smoke temperature data to generate a smoke coverage range, obtaining a laser cutting average smoke concentration coverage range according to the laser cutting average smoke concentration, and the overlapping range of the smoke coverage range and the laser cutting average smoke concentration coverage range is the safety area; measuring the spatial average smoke concentration of the smoke concentration in the first safety area by a smoke detection device, and adjusting the power of the laser cutting device according to the comparison result between the measurement result and the set spatial average smoke concentration safety value.

2. The method for detecting the smoke concentration for laser cutting according to claim 1, wherein The process of detecting the concentrations of the smoke generated in the first cutting stage and the second cutting stage respectively by a smoke concentration detection device to obtain the smoke concentration, and classifying the detection methods into a laser cutting average smoke concentration detection method and a spatial average smoke concentration detection method includes: detecting the smoke concentration generated during each cutting by a smoke concentration detection device, and obtaining the laser cutting average smoke concentration according to the detection result and the cutting time of the laser cutting device each time.

3. The method for detecting the smoke concentration for laser cutting according to claim 2, wherein The safety area includes: a first safety area, the origin of the first safety area is centered on the workpiece to be processed, and the area determined by the auxiliary gas flow rate in the positive diffusion direction along the laser cutting direction; a second safety area, the origin of the second safety area is centered on the workpiece to be processed, and the area determined by the auxiliary gas flow rate in the positive diffusion direction along the reverse direction of laser cutting.

4. The method for detecting the smoke concentration for laser cutting according to claim 3, wherein Based on the situation that adjusting the power of the laser cutting device does not meet the smoke concentration in the first safety area, adjusting the auxiliary gas flow rate of the laser cutting device.

5. A smoke concentration detection system for laser cutting, which adopts the smoke concentration detection method for laser cutting according to any one of claims 1-4, characterized in that, including, an image processing module for image formation of the surface image of the workpiece to be processed; a positioning module for focus positioning of the laser cutting device; A control module for controlling the image processing module and the positioning module; A data processing module, which is connected to the image processing module, the positioning module, and the control module, for processing the data collected by each module and controlling the operation process of each module through the control module.

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