Laser cleaning method and laser cleaning device

Abstract

The invention belongs to the field of laser cleaning, and particularly relates to a laser cleaning method and a laser cleaning device. In order to clean a complex curved surface workpiece, the invention provides a laser cleaning method, a plurality of distance measuring sensors synchronously moving with a laser cleaning head are used for focusing, the distance measuring sensors are arranged on the same mounting plane in a non-collinear manner, and the distance between the distance measuring sensors and the focal plane of the laser cleaning head is L, the distance measuring sensor measures the distance l from the measuring points on the surface of the workpiece, all the measuring points are fitted in the same measuring plane, the average value l of the distance l and the included angle between the normal direction of the measuring plane and the main optical axis of the laser cleaning head are calculated, and the positions and postures of the laser cleaning head and the distance measuring sensor are adjusted in real time. And the difference value between the included angle between the measuring plane and the calibration plane and the set included angle is always less than 5 degrees, and l is greater than or equal to 0.95 L and less than or equal to 1.05 L. The included angle and the distance between the measuring plane and the focal plane are controlled to ensure that the laser cleaning head is at the optimal cleaning angle and the optimal cleaning focal length.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of laser cleaning, and particularly relates to a laser cleaning method and a laser cleaning device. BACKGROUND

[0002] For a planar workpiece, a fixed automatic device can be used to clean the surface of the workpiece, the fixed automatic device comprising a three-axis industrial robot and a laser cleaning head mounted on the three-axis industrial robot as an end effector, the three-axis industrial robot being capable of driving the laser cleaning head to move along x, y and z directions, so that the laser cleaning head can be controlled by a controller to move according to a preset path, and a single-point distance measuring sensor is further mounted on the three-axis industrial robot to measure the distance between the laser cleaning head and the surface of the workpiece, so that the distance between the laser cleaning head and the surface of the workpiece can be adjusted according to the data measured by the single-point distance measuring sensor, thereby realizing focusing and ensuring that the focal point of the laser cleaning head is located on the surface of the workpiece and the cleaning effect is ensured.

[0003] When the fixed automatic device is used, the controller drives the laser cleaning head to move along the preset path to clean the entire surface of the planar workpiece.

[0004] For a workpiece with a planar surface, only the inclination angle of the laser cleaning head needs to be preset, for a workpiece made of ordinary material (for example, iron), the reflectivity of the workpiece is low, at this time, the laser cleaning head is preferably perpendicular to the surface of the workpiece, and the cleaning effect is best, for a workpiece made of high-reflectivity material (for example, copper), the reflectivity of the workpiece is high, at this time, the laser cleaning head is preferably at an 80° angle with the surface of the workpiece, on the one hand, the cleaning effect can be ensured, and on the other hand, the damage of the laser cleaning head and other accessories caused by the perpendicular reflection of the laser can be effectively avoided.

[0005] However, for a complex curved surface workpiece (such as a wind power blade, a ship hull, an aircraft skin, etc.), the above-mentioned fixed automatic device lacks self-adaptive ability to the surface topography of the complex curved surface workpiece, resulting in insufficient control precision of the laser focal point position and affecting the cleaning efficiency and cleaning effect.

[0006] At present, the laser cleaning of the complex curved surface workpiece is mostly performed by manually holding a laser gun, and the cleaning effect is poor and the cleaning efficiency is low. SUMMARY

[0007] The present application aims to provide a laser cleaning method to solve the technical problem that the existing fixed automatic device cannot be used to clean a complex curved surface workpiece.

[0008] The present application also aims to provide a laser cleaning device to solve the technical problem that the existing fixed automatic device cannot be used to clean a complex curved surface workpiece.

[0009] To achieve the above object, the technical scheme of the laser cleaning method provided by the application is as follows: A laser cleaning method, which utilizes a basic ranging sensor moving synchronously with a laser cleaning head to focus, the basic ranging sensor is at least three and arranged non-collinearly on the same installation plane, the installation plane is perpendicular to the main optical axis of the laser cleaning head, the ranging direction of the basic ranging sensor is parallel to the main optical axis, the focal plane of the laser cleaning head is defined as a calibration plane, and the distance between the basic ranging sensor and the calibration plane is L ; During laser cleaning, each basic ranging sensor is used to measure the distance between different measuring points on the workpiece surface and the basic ranging sensor l , all the measuring points are fitted into the same measuring plane, and the average value of all the distances l l 均 is calculated, and the three-dimensional position and the inclination angle of the laser cleaning head and the basic ranging sensor are adjusted in real time, so that the included angle between the measuring plane and the calibration plane is always less than 5°, and 0.95 L ≤ l 均 ≤1.05 L , and the set included angle depends on the reflectivity of the workpiece.

[0010] Furthermore, the calibration plane has a calibration point corresponding to the basic ranging sensor, the distance between the calibration point and the corresponding basic ranging sensor is L , the included angle between the measuring plane and the calibration plane is calculated according to the coordinates of the calibration point and the coordinates of the measuring point, and during the adjustment, the inclination angle of the laser cleaning head and the basic ranging sensor is adjusted first, so that the included angle between the measuring plane and the calibration plane is always less than 5°, and then the laser cleaning head and the basic ranging sensor are translated, so that 0.95 L ≤ l 均 ≤1.05 L .

[0011] Furthermore, in the extension direction of the main optical axis, the distance between the light ray amplitude surface at the light outlet of the laser cleaning head and the center point of all the basic sensors is defined as H , if the light ray amplitude surface at the light outlet of the laser cleaning head is closer to the calibration plane than the center point of all the basic ranging sensors, then L = f + H , if the center point of all the basic ranging sensors is closer to the calibration plane than the light ray amplitude surface at the light outlet of the laser cleaning head, then L = f - H , and if the center point of all the basic ranging sensors is coplanar with the light ray amplitude surface at the light outlet of the laser cleaning head, then H =0,​L = f+H ; wherein, f is the focal length of the laser cleaning head.

[0012] Further, the basic ranging sensors are distributed at the vertices of the same polygon.

[0013] Further, the number of laser cleaning heads is one, and the center point of the polygon is located on the main optical axis of the laser cleaning head; or the number of laser cleaning heads is at least two, and the center point of the polygon is located on the central axis of the main optical axes of all the laser cleaning heads.

[0014] Further, the number of basic ranging sensors is three, and the three basic ranging sensors are located at the three vertices of an equilateral triangle.

[0015] Further, a plurality of auxiliary extended ranging sensors are also installed on the mounting plane, the ranging direction of the auxiliary extended ranging sensors is parallel to the main optical axis, and the auxiliary extended ranging sensors are arranged around the closed figure connected by the basic ranging sensors, so as to predict the shape of the surface of the workpiece that needs to be cleaned next by the data measured by the auxiliary extended ranging sensors during laser cleaning.

[0016] Further, a plurality of auxiliary extended ranging sensors are also installed on the mounting plane, the ranging direction of the auxiliary extended ranging sensors is parallel to the main optical axis, and the auxiliary extended ranging sensors are located on at least two adjacent sides of the four sides of the figure surrounded by the basic ranging sensors, and on each side where the auxiliary extended ranging sensors are located, part of the auxiliary extended ranging sensors and part of the basic ranging sensors surround a polygon that is the same as the figure surrounded by all the basic ranging sensors and coincides with one side of the figure surrounded by all the basic ranging sensors.

[0017] Further, before laser cleaning, the laser cleaning head is moved along the x and z directions along the outer contour of the workpiece, and the outer contour of the workpiece is recorded, during cleaning, the laser cleaning head is controlled to perform S-shaped reciprocating motion along the x and z directions to clean the entire surface within the outer contour, and the y direction position and the inclination angle of the laser cleaning head are controlled to ensure that the included angle between the measurement plane and the calibration plane is always less than 5°, and 0.95L l 均 ≤1.05L.

[0018] The laser cleaning method provided by the application has the beneficial effect that the application is an improved invention. The main difference between the application and the prior art is that the prior art only relies on the distance measured by a single ranging sensor for focusing, while the application relies on at least three ranging sensors to determine the measurement plane, and focuses according to the included angle and distance between the measurement plane and the focal plane.

[0019] The measuring plane is determined by using at least three distance measuring sensors, and the actual surface of the workpiece is replaced by the measuring plane, the angle between the measuring plane and the calibration surface (the focal plane of the laser cleaning head) is always less than 5°, so that the measuring plane is basically parallel to the focal plane, and on this basis, the average value of the distances measured by all the distance measuring sensors l 均 The distance between the distance measuring sensor and the focal plane L is not more than 5%, so that the measuring plane is basically coincident with the focal plane, so that the focal point is basically located on the surface of the workpiece, and the laser cleaning head is in the best cleaning focal length and the best cleaning angle.

[0020] Wherein, the distance between the distance measuring sensor and the focal plane L is used as the reference value, instead of using the focal length of the laser cleaning head f as the reference value, because the laser cleaning head and the basic distance measuring sensor have a certain size, so the distance between the basic distance measuring sensor and the calibration surface is actually not equal to f , and introducing L can make the focusing more accurate.

[0021] Wherein, the reason for setting the angle to be always less than 5° is that when the angle is greater than 5°, the perpendicularity of the laser to the surface of the workpiece is poor, and the laser cleaning effect is poor; similarly, the reason for setting 0.95 L ≤ l 均 ≤1.05 L is that when the difference between l 均 and L is greater than 5%, the laser cannot be well focused on the surface of the workpiece, and the laser cleaning effect is poor.

[0022] To achieve the above purpose, the technical scheme of the laser cleaning device provided by the present application is: A laser cleaning device, comprising a multi-axis industrial robot and a laser cleaning head mounted on the multi-axis industrial robot and serving as an end effector, the laser cleaning head being provided with distance measuring sensors that move synchronously with the laser cleaning head and are used for focusing, the distance measuring sensors being at least three and being arranged in a same mounting plane of the multi-axis industrial robot in a non-collinear manner, the mounting plane being perpendicular to a main optical axis of the laser cleaning head, and the distance measuring direction of the distance measuring sensors being parallel to the main optical axis, the multi-axis industrial robot being used for synchronously adjusting the three-dimensional coordinates and the tilt angle of the laser cleaning head and the distance measuring sensors, so as to realize the following laser cleaning method: Focusing is achieved using base rangefinders that move synchronously with the laser cleaning head. At least three base rangefinders are arranged non-collinearly on the same mounting plane, which is perpendicular to the principal optical axis of the laser cleaning head. The ranging direction of the base rangefinders is parallel to the principal optical axis. The focal plane of the laser cleaning head is defined as the calibration plane, and the distance from the base rangefinders to the calibration plane is... L ; During laser cleaning, each base distance sensor is used to measure the distance from different measuring points on the workpiece surface to the base distance sensor. l Fit all measuring points to the same measuring plane and calculate all distances. l average l 均 The three-dimensional position and tilt angle of the laser cleaning head and the base ranging sensor are adjusted in real time to ensure that the difference between the angle between the measuring plane and the calibration plane and the set angle is always less than 5°, and 0.95 L ≤ l 均 ≤1.05 L The angle is set according to the reflectivity of the workpiece.

[0023] Furthermore, the calibration surface has calibration points corresponding to the base ranging sensor, and the distance from the calibration point to the corresponding base ranging sensor is... L The angle between the measuring plane and the calibration plane is calculated based on the coordinates of the calibration point and the measuring point. During adjustment, the tilt angles of the laser cleaning head and the base distance sensor are first adjusted to ensure that the difference between the angle between the measuring plane and the calibration plane and the set angle is always less than 5°. Then, the laser cleaning head and the base distance sensor are translated to make the angle 0.95°. L ≤ l 均 ≤1.05 L .

[0024] Furthermore, along the extension direction of the main optical axis, the distance from the light beam at the laser cleaning head's output port to the center point of all basic sensors is defined as... H If the beam width at the laser cleaning head's output port is closer to the calibration surface than the center point of all the basic ranging sensors, then L = f + H If the center point of all the basic ranging sensors is closer to the calibration surface than the light beam area at the laser cleaning head's output port, then L = f - H If the center point of all the basic ranging sensors is coplanar with the light beam area at the laser cleaning head's output port, then H =0, L = f+H In the formula, fThe focal length of the laser cleaning head.

[0025] Further, the basic ranging sensors are distributed at the vertices of the same polygon.

[0026] Further, the number of the laser cleaning heads is one, and the center point of the polygon is located on the main optical axis of the laser cleaning head; or the number of the laser cleaning heads is at least two, and the center point of the polygon is located on the central axis of the main optical axes of all the laser cleaning heads.

[0027] Further, the number of the basic ranging sensors is three, and the three basic ranging sensors are located at the three vertices of an equilateral triangle.

[0028] Further, a plurality of auxiliary extended ranging sensors are installed on the mounting plane, the ranging direction of the auxiliary extended ranging sensors is parallel to the main optical axis, and the auxiliary extended ranging sensors are arranged around the closed figure connected by the basic ranging sensors, so as to predict the shape of the surface of the workpiece to be cleaned next by the data measured by the auxiliary extended ranging sensors during the laser cleaning.

[0029] Further, a plurality of auxiliary extended ranging sensors are installed on the mounting plane, the ranging direction of the auxiliary extended ranging sensors is parallel to the main optical axis, and the auxiliary extended ranging sensors are located on at least two adjacent sides of the four sides of the figure surrounded by the basic ranging sensors, and on each side where the auxiliary extended ranging sensors are located, part of the auxiliary extended ranging sensors and part of the basic ranging sensors surround a polygon which is the same as the figure surrounded by all the basic ranging sensors and coincides with one side of the figure surrounded by all the basic ranging sensors.

[0030] Further, before the laser cleaning, the laser cleaning head is moved along the x and z directions along the outer contour of the workpiece, and the outer contour of the workpiece is recorded, during the cleaning, the laser cleaning head is controlled to perform S-shaped reciprocating motion along the x and z directions to clean the entire surface in the outer contour, and the y direction position and the inclination angle of the laser cleaning head are controlled to ensure that the included angle between the measurement plane and the calibration plane is always less than 5°, and 0.95L≤ l 均 ≤1.05L.

[0031] The laser cleaning device provided by the application has the following beneficial effects: the application is an improved invention. The main difference between the application and the prior art is that the prior art only relies on the distance measured by a single ranging sensor for focusing, while the application relies on at least three ranging sensors to determine the measurement plane, and the focusing is performed according to the included angle and the distance between the measurement plane and the focal plane.

[0032] At least three distance sensors are used to determine the measurement plane, which is then used to replace the actual surface of the workpiece. The angle between the measurement plane and the calibration plane (the focal plane of the laser cleaning head) is always kept less than 5° to ensure that the measurement plane is essentially parallel to the focal plane. Based on this, the average distance measured by all distance sensors is calculated... l 均 Distance from the ranging sensor to the focal plane L The difference is no more than 5%, which can ensure that the measuring plane and the focal plane are basically coincident, thereby ensuring that the focal point is basically located on the surface of the workpiece, and ensuring that the laser cleaning head is at the optimal cleaning focal length and the optimal cleaning angle.

[0033] Among them, utilizing L Used as a reference value, rather than utilizing the focal length of the laser cleaning head. f The reason for using this as a benchmark value is that, due to the certain dimensions of the laser cleaning head and the base ranging sensor, the actual distance from the base ranging sensor to the calibration surface is not equal to... f , Introduction L It can make focusing more precise.

[0034] The reason for setting the included angle to always be less than 5° is that when the included angle is greater than 5°, the perpendicularity between the laser and the workpiece surface is poor, resulting in a poor laser cleaning effect; similarly, setting it to 0.95... L ≤ l 均 ≤1.05 L The reason is: l 均 and L When the difference is greater than 5%, the laser cannot be well focused on the workpiece surface, resulting in poor laser cleaning effect. Attached Figure Description

[0035] Figure 1 A schematic diagram of the laser cleaning device from one angle (air and water pipes omitted); Figure 2 This is a schematic diagram of the laser cleaning device from another angle; Figure 3 for Figure 1 A schematic diagram of the structure of the laser cleaning head and the basic ranging sensor (the auxiliary extended ranging sensor is not shown). Figure 4 A schematic diagram for determining the outer contour of a workpiece; Figure 5 This is a path diagram of the laser cleaning head performing S-shaped reciprocating motion along the x and z directions during laser cleaning. Figure 6 A schematic diagram of focusing using a basic rangefinder sensor (sensor reference plane not shown). Figure 7The schematic diagram for laser cleaning by using the basic distance measuring sensor and the auxiliary extended distance measuring sensor; Figure 8 The schematic diagram for laser cleaning by using the basic distance measuring sensor and the auxiliary extended distance measuring sensor; Figure 9 The schematic diagram for laser cleaning by using the basic distance measuring sensor and the auxiliary extended distance measuring sensor; Figure 10 The schematic diagram for laser cleaning by using the basic distance measuring sensor and the auxiliary extended distance measuring sensor.

[0036] Mark explanation: 1, foot; 2, linear guide; 3, rack; 4, gear; 5, x-axis servo motor; 6, moving table; 7, motor driver; 8, buffer rubber block; 9, laser control box; 10, tank chain; 11, support frame; 12, column; 13, water cooling machine; 14, water cooling machine control box; 15, three-color lamp; 16, z-axis servo motor; 17, cantilever assembly; 18, y-axis servo motor; 19, laser; 20, base extension connecting block; 21, first safety switch; 22, water pipe; 23, air pipe; 24, display screen; 25, second safety switch; 26, compressed air pump; 27, v-axis servo motor; 281, first rotary table; 282, second rotary table; 29, u-axis servo motor; 30, laser cleaning head; 31, mounting plane; 32, basic distance measuring sensor. DETAILED DESCRIPTION

[0037] To solve the problems in the background art, the core inventive concept of the present application is: using at least three distance measuring sensors to determine a measurement plane, and using the measurement plane to replace the actual surface of the workpiece, by making the included angle between the measurement plane and the calibration plane (the focal plane of the laser cleaning head) always less than 5°, ensuring that the measurement plane is basically parallel to the focal plane (or the main optical axis of the laser cleaning head is basically parallel to the normal line of the measurement plane, or the main optical axis of the laser cleaning head is basically parallel to the normal line of the actual surface of the workpiece), on this basis, by making the average value of the distances measured by all distance measuring sensors l 均 The distance between the distance measuring sensor and the focal plane L The difference is not more than 5%, which can ensure that the measurement plane and the focal plane are basically coincident, thereby ensuring that the focal point is basically located on the surface of the workpiece, and ensuring that the laser cleaning head is at the best cleaning focal length and the best cleaning angle.

[0038] Among them, the L is used as the reference value, rather than using the focal length of the laser cleaning head f as the reference value, because the laser cleaning head and the basic distance measuring sensor have a certain size, so the distance between the basic distance measuring sensor and the calibration plane is actually not equal to f, Introduction L It can make focusing more precise.

[0039] The reason for setting the included angle to always be less than 5° is that when the included angle is greater than 5°, the perpendicularity between the laser and the workpiece surface is poor, resulting in a poor laser cleaning effect; similarly, setting it to 0.95... L ≤ l 均 ≤1.05 L The reason is: l 均 and L When the difference is greater than 5%, the laser cannot be well focused on the workpiece surface, resulting in poor laser cleaning effect.

[0040] The present invention will be further described in detail below with reference to the embodiments.

[0041] Examples of laser cleaning methods are as follows.

[0042] Reference Figures 1-9 As shown, in a basic embodiment, the laser cleaning method is as follows: focusing is performed using a base ranging sensor 32 that moves synchronously with the laser cleaning head 30. Simultaneously, the base ranging sensor 32 has at least three ( Figures 6-8 Specifically, there are three sensors, namely range sensor a, range sensor b, and range sensor c, all mounted on the same plane 31 (i.e., Figure 6 The sensors are arranged non-collinearly on the reference plane of the laser cleaning head 30. The mounting plane 31 is perpendicular to the principal optical axis of the laser cleaning head 30, and the ranging direction of the basic ranging sensor 32 is parallel to the principal optical axis. The focal plane of the laser cleaning head 30 is defined as the calibration plane (i.e., the reference plane of the laser cleaning head 30). Figure 6 The distance between the calibration surface (set in the calibration plane) and the base ranging sensor 32 is... L ; During laser cleaning, each base distance sensor 32 is used to measure the distance from different measuring points on the workpiece surface to the base distance sensor 32. l Fit all measuring points to the same measuring plane (i.e. Figure 6 Within the actual measurement surface (in the diagram), calculate all distances. l average l 均 The three-dimensional position and tilt angle of the laser cleaning head 30 and the base ranging sensor 32 are adjusted in real time to ensure that the difference between the angle between the measuring plane and the calibration plane and the set angle is always less than 5° and 0.95. L ≤ l 均 ≤1.05 L .

[0043] The main optical axis refers to a straight line where two focal points are located, the focal plane is perpendicular to the main optical axis, and the focal point is located on the focal plane; the set angle depends on the reflectivity of the workpiece. For a workpiece made of ordinary material (for example, iron), the reflectivity of the workpiece is low, at this time, the laser cleaning head 30 is preferably perpendicular to the surface of the workpiece (the corresponding set angle is 90°), and the cleaning effect is best. For a workpiece made of high-reflectivity material (for example, copper), the reflectivity of the workpiece is high, at this time, the laser cleaning head 30 is preferably at an angle of 80° with the surface of the workpiece (the corresponding set angle is 80°), on the one hand, the cleaning effect can be ensured, and on the other hand, laser damage to the laser cleaning head 30 and other accessories caused by perpendicular reflection of laser can be effectively avoided. Of course, according to the actual reflectivity of the workpiece (mainly determined by the material), the skilled in the art can also set the set angle to 85° or other angles according to the actual situation.

[0044] As shown in Figures 6-7 , when the angle between the measurement plane (i.e. the actual measurement plane in Figure 6 ) and the calibration plane (i.e. the set calibration plane in Figure 6 ) is always less than 5°, it can be considered that the measurement plane and the calibration plane are basically parallel, at this time, as shown in Figures 7-8 , the angle between the main optical axis of the laser and the normal line of the measurement plane is less than 5°, it can be considered that the main optical axis of the laser and the normal line of the measurement plane are basically parallel, and it can be considered that the laser is basically vertically hit on the measurement plane to ensure that the laser cleaning head 30 is at the best cleaning angle. The reason why the set angle is always less than 5° is that when the angle is greater than 5°, the perpendicularity of the laser to the surface of the workpiece is poor, and the laser cleaning effect is poor.

[0045] As shown in Figure 6 , under the premise that the angle between the measurement plane and the calibration plane is always less than 5°, when 0.95 L ≤ l 均 ≤1.05 L , it can be considered that the measurement plane (i.e. the actual measurement plane in Figure 6 ) and the calibration plane (i.e. the set calibration plane in Figure 6 ) are basically coincident, at this time, it can be considered that the focal point of the laser (with a certain focal depth) falls on the measurement plane to ensure that the laser cleaning head 30 is at the best cleaning focal length.

[0046] Wherein L is used as a reference value, rather than using the focal length f of the laser cleaning head 30 as a reference value. The reason is that because the laser cleaning head 30 and the basic distance sensor 32 have a certain size, the distance between the basic distance sensor 32 and the calibration plane is actually not equal to f , introducing L can make the focusing accuracy more accurate.

[0047] like Figure 3 and Figure 10 As shown, in the direction of extension of the main optical axis, the beam width at the output port of the laser cleaning head 30 (i.e., Figure 10 The laser cleaning head beam area is compared to the center point of all the basic ranging sensors 32 (i.e., Figure 10 The center point of the basic ranging sensor group (all basic ranging sensors 32 together constitute the basic ranging sensor group) is closer to the calibration surface. The distance from the light beam at the output port of the laser cleaning head 30 to the center point of all basic sensors 32 is... H ,but L = f + H In other embodiments, if the center point of all the base ranging sensors 32 is closer to the calibration surface than the light beam area at the light outlet of the laser cleaning head 30, then L = f - H If the center point of all the basic ranging sensors 32 is coplanar with the light beam area at the light outlet of the laser cleaning head 30, then H =0, L = f+H By introducing an H value for adjustment, the center point of all the base range sensors 32 and the light beam at the light outlet of the laser cleaning head 30 can be considered to be on the same plane, thereby eliminating the influence of the installation position and size of the base range sensors 32 and the laser cleaning head 30, and better ensuring that the laser cleaning head 30 is at the optimal cleaning focal length.

[0048] Among them, 0.95 is set. L ≤ l 均 ≤1.05 L The reason is: when l 均 and L When the difference is greater than 5%, the laser cannot be well focused on the workpiece surface, resulting in poor laser cleaning effect.

[0049] Therefore, by adjusting the angle between the measuring plane and the calibration plane to always be less than 5°, and 0.95 L ≤ l 均 ≤1.05 L This effectively ensures that the laser cleaning head 30 is at the optimal cleaning angle and focal length, adapting to complex curved workpieces (e.g., Figures 7-8 The workpiece shown in the image.

[0050] The three non-collinear points determine a plane, so the number of the basic distance sensors 32 can be three, four or more, and the basic distance sensors 32 can be arranged as long as they are not all arranged on the same straight line, and the positions of the basic distance sensors 32 can be arranged according to actual needs by those skilled in the art.

[0051] In the present application, the calibration plane has calibration points [coordinates a3(x7, y7, z7), b3(x8, y8, z8), c3(x9, y9, z9)] corresponding to the basic distance sensors 32, and the distances between the calibration points and the corresponding basic distance sensors 32 [coordinates a1(x1, y1, z1), b1(x2, y2, z2), c1(x3, y3, z3)] are L , and the angle between the measurement plane and the calibration plane is calculated according to the coordinates of the calibration points and the coordinates of the measurement points [coordinates a2(x4, y4, z4), b2(x5, y5, z5), c2(x6, y6, z6)]; during adjustment, the tilt angles of the laser cleaning head 30 and the basic distance sensors 32 are first adjusted so that the difference between the angle between the measurement plane and the calibration plane and the set angle is always less than 5°, and then the laser cleaning head 30 and the basic distance sensors 32 are translated so that 0.95 L ≤ l 均 ≤1.05 L In this control method, the tilt angle and the focusing distance (the focusing distance is equal to l 均 The calculation amount during the two adjustments is small.

[0052] In other embodiments, the tilt angle and the focusing distance can also be adjusted at the same time to improve the adjustment rate.

[0053] In a preferred embodiment, the basic distance sensors 32 are arranged at the vertices of the same regular polygon, and at this time, the distances between the basic distance sensors 32 and the center point of the corresponding regular polygon are equal, so the weights of the data measured by the basic distance sensors 32 are equal, and therefore the average value l 均 The actual distance between the sensor reference plane (i.e. the mounting plane 31) and the workpiece surface (replaced by the measurement plane) is closer, so that the coincidence of the focal plane and the workpiece surface is better, and the cleaning effect is improved.

[0054] Referring to FIGS. 1, 2 and 3, Figure 3 and Figures 6-8 The regular polygon can be a regular triangle, of course, according to the number of the basic distance sensors 32, the regular polygon can also be a regular quadrilateral, a regular pentagon, etc. Of course, the basic distance sensors 32 can also be arranged at the vertices of other polygons that are not regular polygons.

[0055] After the focal plane is determined to coincide with the measurement plane, theoretically, the focal point of the laser cleaning head 30 falls on the measurement plane regardless of the relative position of the laser cleaning head 30 and the basic ranging sensor 32.

[0056] However, in the present application, since the workpiece surface is actually a complex curved surface, when the relative position of the laser cleaning head 30 and the basic ranging sensor 32 is different, the position of the laser emitted by the laser cleaning head 30 on the workpiece surface is different, and thus the curved surface actually hit by the laser is different.

[0057] In order to reduce the deviation of the curved surface hit by the laser from the measurement plane fitted according to the basic ranging sensor 32, the present application proposes the following two preferred embodiments.

[0058] One is that the number of the laser cleaning head 30 is one, and the center point of the regular polygon is located on the main optical axis of the laser cleaning head 30, that is, the distance from each basic ranging sensor 32 to the main optical axis is equal. At this time, the deviation of the curved surface hit by the laser from the measurement plane is the smallest.

[0059] The second is that the number of the laser cleaning head 30 is at least two, and the center point of the regular polygon is located on the central axis of the main optical axes of all the laser cleaning heads 30. In this embodiment, while ensuring that the deviation of the curved surface hit by the laser from the measurement plane is small, the number of the laser cleaning head 30 is larger, and the area of single cleaning is larger, which is conducive to improving the cleaning efficiency.

[0060] The number of the laser cleaning head 30 can be two, three or more, and those skilled in the art can balance the number of the laser cleaning head 30 and the number of the basic ranging sensor 32 to improve the cleaning efficiency while meeting the cleaning quality requirements.

[0061] Referring to FIG. 1, Figures 1-3 In a preferred embodiment, when the number of the basic ranging sensor 32 is three, the number of the laser cleaning head 30 is two, and the center point of the equilateral triangle is located on the central axis of the main optical axes of all the laser cleaning heads 30. At this time, on the one hand, the number of the laser cleaning head 30 is larger, and the area of single cleaning is larger, which is conducive to improving the cleaning efficiency; on the other hand, the number of the laser cleaning head 30 is not too large, and the deviation of the curved surface hit by the laser from the measurement plane is small, which meets the cleaning quality requirements.

[0062] In the above embodiment, referring to FIG. 1, Figures 1-7 As shown in FIG. 1, the focusing is completed only by the basic ranging sensor 32.

[0063] In other embodiments, referring to FIG. 2, Figures 7-8As shown, a plurality of auxiliary extended range-finding sensors are also installed on the mounting plane 31, which are arranged around the closed figure connected by the basic range-finding sensors 32, for pre-judging the shape of the surface of the workpiece that needs to be cleaned next by the data measured by the auxiliary extended range-finding sensors during laser cleaning.

[0064] In Figure 8 , the auxiliary extended range-finding sensors are seven, and are respectively range-finding sensor d, range-finding sensor e, range-finding sensor f, range-finding sensor g, range-finding sensor f, range-finding sensor g.

[0065] The relative position relationship between the laser cleaning head 30 and the surface of the workpiece can be preliminarily positioned by the auxiliary extended range-finding sensors, and the relative position relationship between the laser cleaning head 30 and the surface of the workpiece can be precisely positioned by the basic range-finding sensors 32, so as to realize efficient laser cleaning of a complex curved surface.

[0066] In this mode, the curved surface that needs to be cleaned is divided into a plurality of patches in real time, and each patch is spatially analyzed to obtain the normal direction of each patch, and the position and posture of the laser cleaning head 30 are adjusted according to the obtained results.

[0067] Referring to Figure 7 , the range-finding sensor a, the range-finding sensor b and the range-finding sensor c are all basic range-finding sensors 32, and the three sensors measure the spatial point coordinates A0.0, A0.1 and A0.2 of three corners of a patch, and the normal direction of the patch can be calculated by spatial analytic geometry calculation, and then the included angle between the main optical axis of the laser cleaning head 30 and the normal of the patch can be calculated. By adjusting the three-dimensional positions of the laser cleaning head 30 in x, y and z directions and the inclination angles in u and v directions, the laser can be made to hit the curved surface at a suitable angle.

[0068] The auxiliary extended range-finding sensors can measure the spatial point coordinates of A1.0, A1.1, A1.2, A2.0, A2.1 and A2.2, and calculate the normal directions of the patches corresponding to these coordinates, and through data analysis and stitching, the shape of the curved surface in the scanning range can be obtained, and the moving path can be automatically planned according to the known curved surface shape.

[0069] In other embodiments, referring to Figure 9 , the auxiliary extended range-finding sensors are located on at least two adjacent sides (for example, the right side and the lower side in Figure 9 ) of the figure surrounded by the basic range-finding sensors 32, and the moving path of the laser cleaning head 30 can be automatically planned according to the shape of the curved surface in the scanning range. Figure 9In the embodiment shown in FIG. 1, the auxiliary extended ranging sensors 32 are located on the right side and the lower side of the laser cleaning head 30, and the partial auxiliary extended ranging sensors and the partial basic ranging sensors 32 enclose a polygon, preferably a regular polygon, which is the same as the polygon enclosed by all the basic ranging sensors 32 and coincides with one side of the polygon enclosed by all the basic ranging sensors 32.

[0070] In the embodiment shown in FIG. 1, the auxiliary extended ranging sensors 32 are located on the right side and the lower side of the laser cleaning head 30, and the partial auxiliary extended ranging sensors and the partial basic ranging sensors 32 enclose a polygon, preferably a regular polygon, which is the same as the polygon enclosed by all the basic ranging sensors 32 and coincides with one side of the polygon enclosed by all the basic ranging sensors 32. Figure 9

[0071] In the embodiment shown in FIG. 1, the auxiliary extended ranging sensors 32 are located on the right side and the lower side of the laser cleaning head 30, and the partial auxiliary extended ranging sensors and the partial basic ranging sensors 32 enclose a polygon, preferably a regular polygon, which is the same as the polygon enclosed by all the basic ranging sensors 32 and coincides with one side of the polygon enclosed by all the basic ranging sensors 32. Figure 4 Figure 5 l 均

[0072] In other embodiments, the profile of the entire surface of the workpiece can also be determined by a vision sensor, and the data of the vision sensor can be used to control the laser cleaning head 30 to clean the entire surface of the workpiece. For reference, please refer to the Chinese patent application with the application publication number CN117619823A and the application publication date of March 1, 2024, or the Chinese patent application with the application publication number CN117443853A and the application publication date of January 26, 2024.

[0073] In other embodiments, if the specific three-dimensional model of the workpiece is known, the three-dimensional model can be directly imported into the control system (including CPU), and the control system can automatically calculate the cleaning path.

[0074] The embodiment of the laser cleaning device is as follows.

[0075] The laser cleaning device in the present application is used to implement the laser cleaning method in the present application.

[0076] As shown in FIG. 1, the laser cleaning device comprises a laser cleaning head 30, a workpiece 10, a control system (including CPU), a laser cleaning head driving system, a workpiece driving system, a ranging sensor system, a vision sensor system, and a laser cleaning head cleaning system. Figures 1-3 ​​​​As shown, as a basic embodiment, the laser cleaning device comprises a multi-axis industrial robot and a laser cleaning head 30 mounted on the multi-axis industrial robot and serving as an end effector, the laser cleaning head 30 is configured with a ranging sensor (at least including a basic ranging sensor 32, and can include an auxiliary extended ranging sensor) that moves synchronously with the laser cleaning head 30 and is used for focusing, the ranging sensor is at least three, and is arranged non-collinearly on the same mounting plane 31 of the multi-axis industrial robot, the mounting plane 31 is perpendicular to the main optical axis of the laser cleaning head 30, and the multi-axis industrial robot is used for synchronously adjusting the three-dimensional coordinates and tilt angles of the laser cleaning head 30 and the ranging sensor.

[0077] Among them, the multi-axis industrial robot can be a five-axis industrial robot including x-axis, y-axis, z-axis, u-axis and v-axis, or a six-axis industrial robot including w-axis, etc. As long as it can realize that the laser cleaning head 30 sweeps the entire surface of the object to be cleaned and can adjust the cleaning angle of the laser cleaning head 30. The multi-axis industrial robot can be purchased integrally.

[0078] In order to facilitate those skilled in the art to understand, a specific multi-axis industrial robot is provided below.

[0079] As shown in Figures 1-3 The multi-axis industrial robot comprises a base, the base is provided with a moving table 6 movable in cooperation with the base along the x direction, the moving table 6 is provided with a laser 19 for generating laser for the laser cleaning head 30 and a column 12 extending along the z direction, the column 12 is connected with a cantilever assembly 17 movable in cooperation with the column 12 along the z direction, the cantilever assembly 17 comprises a direct drive mechanism for movement along the y direction, the output end of the direct drive mechanism is connected with a first rotary table 281 rotating along the v direction, the first rotary table 281 is connected with a second rotary table 282 rotating along the u direction, the second rotary table 282 has the mounting plane 31, and the laser cleaning head 30 is also mounted on the mounting plane 31; the moving table 6, the cantilever assembly 17, the direct drive mechanism, the first rotary table 281 and the second rotary table 282 are all provided with corresponding servo motors.

[0080] The base comprises a linear guide rail 2 and a supporting leg 1, the linear guide rail 2 is provided with a rack 3 extending along the x direction, the moving table 6 is provided with a gear 4 engaged with the rack 3, and the moving table 6 is movable in cooperation with the linear guide rail 2 along the x direction, the moving table 6 is provided with an x-axis servo motor 5, the x-axis servo motor 5 drives the gear 4 to rotate to drive the moving table 6 to move along the x direction. The base is also provided with a baffle for preventing the moving table 6 from separating from the linear guide rail 2 along the x direction, and the baffle is provided with a buffer rubber block 8 for buffering the collision between the baffle and the moving table 6. At the same time, the base has a connecting block 20 for extending the base, so as to extend the x direction length of the base.

[0081] The mobile platform 6 is also equipped with a laser 19 for generating laser light, a laser control box 9, and a motor driver 7. The column 12 is equipped with a support frame 11 to strengthen the structure of the column 12. The laser control box 9 includes a first safety switch 21.

[0082] The cantilever assembly 17 is equipped with a z-axis servo motor 16 mounted on the column 12, which can drive the cantilever assembly 17 to rise and fall.

[0083] The direct drive mechanism is equipped with a y-axis servo motor 18, which is used to drive the y-axis slide in the direct drive mechanism to move along the y-axis.

[0084] A v-axis servo motor 27 is mounted on the y-axis slide, and the output end of the v-axis servo motor 27 is connected to the first turntable 281. A u-axis servo motor 29 is mounted on the first turntable 281, and the output end of the u-axis servo motor 29 is connected to the second turntable 282. The second turntable 282 has the aforementioned mounting plane 31, and the ranging sensor and the laser cleaning head 30 are both mounted on the mounting plane 31.

[0085] The laser 19 generates a lot of heat during operation and needs to be shut down for heat dissipation after a period of operation. To ensure that the laser 19 can operate continuously, it needs to be equipped with an air-cooled or water-cooled heat dissipation mechanism.

[0086] exist Figures 1-3 In the illustrated embodiment, the laser 19 is equipped with a water-cooling heat dissipation mechanism, which includes a water chiller 13. The water chiller 13 is equipped with water-cooling pipes for cooling the laser 19 and the laser cleaning head 30. The portion of the water-cooling pipe used to cool the laser 19 is located upstream of the portion used to cool the laser cleaning head 30. The water chiller 13 is equipped with a water chiller control box 14, which is equipped with a tri-color light 15 to facilitate operators in judging the working status of the laser cleaning device. The water-cooling pipes include water pipes 22, a portion of which is protected by a tank chain 10 to ensure that the water pipes 22 are not damaged when moving with the laser cleaning head 30. The water chiller control box 14 includes a display screen 24 and a second safety switch 25.

[0087] Dust removal is required during laser cleaning. Figures 1-3 In the illustrated embodiment, the laser cleaning apparatus further includes a gas compressor comprising a compressed air pump 26 and an air duct extending to the laser cleaning head 30 for gas dust removal during laser cleaning. At least a portion of the air duct is formed by an air pipe 23, which is also equipped with a tank chain 10 for protection.

[0088] In other embodiments, the laser cleaning device can also include a negative pressure suction dust removal device (or dust collector), and the air inlet of the negative pressure suction dust removal device is located at the laser cleaning head 30, and the air inlet is connected with a negative pressure generator through a pipeline to remove dust in a dust suction manner.

[0089] The following introduces the specific operation process of the laser cleaning method in the application by using the laser cleaning device in the application.

[0090] Step S1, before starting, pure water is added to the water tank of the water cooling machine 13 (a special anti-freezing liquid needs to be added in an environment below 0℃). The machine is powered on, the emergency stop switches of the two control boxes are turned on, and the water cooling machine 13 starts to work. The water flows through the water pipe 22 to pass through the tank chain 10 to deliver to the laser 19 and the cleaning head. The low-temperature water flow enters the laser machine to circulate and work to reduce the temperature. The normal-temperature water flow flows through the laser cleaning head 30 to maintain the normal working temperature. After the system is loaded, the I / O signal is output to the motor driver 7 after 3 seconds of delay, and the controller releases the motor magnetic brake after receiving the signal.

[0091] Step S2, the workpiece to be cleaned is placed in the cleaning effective range, which is 1-1.5 meters away from the laser cleaning head 30 side guide rail, and the length does not exceed the effective range of the guide rail stroke.

[0092] Step S3, after the system is ready, the configuration button on the wireless hand wheel is clicked to complete the pairing connection between the hand wheel and the wireless receiver in the system. The integrated system communicates with the motor controller through the EtherCAT network cable to synchronously control the forward and reverse rotation and the rotating speed of the five motors in the device. The motor uses an absolute value encoder to ensure that the position coordinates are not lost in the power-off state.

[0093] Step S4, after all the preconditions are prepared, the corresponding pulse signal is output by selecting the shaft number of the wireless hand wheel according to the size of the workpiece, and the wireless receiver transmits it to the control system after receiving it. After receiving the corresponding pulse signal, the control system specifies the corresponding motor to run according to the specified track (the X-axis motor drives the laser cleaning head 30 to move along the linear guide rail 2 through the gear 4 and the rack 3, the Y-axis motor controls the forward and backward movement of the laser cleaning head 30 through the motor control ball screw and the sliding block, and the Z-axis motor controls the lifting of the laser cleaning head 30 through the cooperation of the motor, the gear 4, the rack 3 and the linear guide rail 2).

[0094] Step S5, the system controls the scanning width by controlling the deflection amplitude of the galvanometer motor inside the laser cleaning head 30 through the XY2-100 protocol, and synchronously outputs two groups of signals to ensure the coordination and synchronization of the two laser cleaning heads 30. The output power of the laser 19 is controlled by an analog quantity, and the duty cycle and frequency of the laser output are controlled through a pwm interface.

[0095] Step S6, as Figure 4As shown, according to the workpiece size, the laser cleaning head 30 is moved to the upper left corner of the surface to be cleaned by the hand wheel control, the point coordinate A1 is recorded in the control system, and the profile contour line is moved along the upper edge of the workpiece, and the turning point coordinates A2, A3, A4…An are recorded synchronously. After reaching the lower right corner of the workpiece, the workpiece point coordinate B1 is recorded, and then the lower edge is moved, and the edge turning point coordinates B2, B3, B4…Bn are recorded synchronously. The system calculates the cleaning profile and boundary of the workpiece through the recorded coordinate points.

[0096] Step S7, as shown Figure 5 , the system automatically calculates the S-shaped cleaning filling path according to the known boundary and the cleaning area value, and controls the running speed of the axis coordinate according to the set running speed to control the cleaning effect.

[0097] Step S8, after all preparations are completed, the safety switches on the two control boxes are turned on, the program is run, and the laser cleaning head 30 starts to realize the movement of X\Z two axes according to the main path, while the sensor group starts to work.

[0098] Step S9, set the cleaning plane position parameters, plane angle and plane distance. Three infrared sensors (i.e. basic ranging sensors 32) are installed in an equilateral triangle arrangement on the same installation plane 31, and the plane is recorded as the coordinate reference plane S1, and the three sensor coordinates are a1(x1, y1, z1), b1(x2, y2, z2), c1(x3, y3, z3). The center points of a1, b1, and c1 are the origin coordinates O(0, 0, 0). Virtual points a3(x7, y7, z7), b3(x8, y8, z8), and c3(x9, y9, z9) are set, and the set calibration plane S2 is parallel to the sensor reference plane, and the distance between the two planes is the effective focal length of the cleaning head h (i.e. distance L ). In actual operation, the three sensors intersect with three points of the workpiece to determine the actual measurement plane S3, and the intersection points are coordinates a2(x4, y4, z4), b2(x5, y5, z5), and c2(x6, y6, z6). Given the fixed coordinates a1, b1, and c1 of the reference plane S1, the fixed coordinates a3, b3, and c3 of the calibration plane S2, and the follow-up coordinates a2, b2, and c2 of the measurement plane, the normal vector can be determined according to the plane fitting equation to determine the angle between the planes S2 and S3. According to the calculated angle, the motion compensation of the system is converted, and the angle between the reference plane S1 and the measurement plane S2 is adjusted through the mutual cooperation of the v-axis servo motor 27, the u-axis servo motor 29, and the y-axis servo motor 18, so that it always remains in a nearly parallel state (intersection angle <5°). The average value of the distance measurement values l 1, l 2, l 3 of the three basic ranging sensors 32 is calculated l 均According to the use requirement l 均 Need to meet l 均 = L ±5%, if not, according to l 均 The difference between L The system will control the v-axis servo motor 27, the u-axis servo motor 29 and the y-axis servo motor 18 to carry out displacement compensation according to the difference until the set condition is met. The above closed loop operation is real-time monitoring to ensure that the laser cleaning head 30 always maintains the optimal cleaning distance and cleaning angle during the cleaning process.

[0099] Step S10, during the operation of the equipment, the three-color lamp 15 keeps green in standby state, and keeps yellow if the system reports an error or encounters an alarm, and keeps red and has an alarm sound for a long time, so as to facilitate the judgment of the working state of the machine. The laser cleaning head 30 is built-in temperature detection module, if it encounters abnormally high temperature, the system automatically stops to ensure the safety of the equipment and personnel, the laser cleaning head 30 keeps the cleaning of the light outlet through compressed air.

[0100] Finally, it should be noted that the above only for the preferred embodiments of the present application, and not for limiting the present application, although the present application is described in detail with reference to the foregoing embodiments, for those skilled in the art, it still can be modified without paying creative labor to the technical solutions recorded in the foregoing embodiments, or to replace the equivalent part of the technical features, or to combine the different embodiments organically, so as to combine the embodiments given in the drawings, of course, those skilled in the art can also combine the embodiments not given in the drawings of the remaining specification. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A laser cleaning method, which is characterized by, The basic ranging sensors are arranged non-collinearly in at least three and in the same installation plane, the installation plane is perpendicular to the main optical axis of the laser cleaning head, the ranging directions of the basic ranging sensors are parallel to the main optical axis, the focal plane of the laser cleaning head is defined as a calibration plane, and the distance between the basic ranging sensors and the calibration plane is L ; In laser cleaning, each base ranging sensor is used to measure the distance of a different measuring point on the workpiece surface from the base ranging sensor l , all measuring points are fitted into the same measuring plane, and the average of all distances is calculated l l 均 , the three-dimensional position and the tilt angle of the laser cleaning head and the base ranging sensor are adjusted in real time so that the angle between the measuring plane and the calibration plane is always less than 5° from the set angle, and 0.95 L ≤ l 均 ≤1.05 L , the set angle depends on the reflectivity of the workpiece.​ 2. The laser cleaning method of claim 1, wherein the laser beam has a wavelength of 400 nm or less. The calibration surface has a calibration point corresponding to the basic ranging sensor, and the distance between the calibration point and the corresponding basic ranging sensor is L The angle between the measurement plane and the calibration surface is calculated according to the coordinates of the calibration point and the coordinates of the measuring point; during adjustment, the inclination angle of the laser cleaning head and the basic ranging sensor is first adjusted, so that the difference between the angle between the measurement plane and the calibration surface and the set angle is always less than 5°, and then the laser cleaning head and the basic ranging sensor are translated, so that 0.95 L ≤ l 均 ≤1.05 L .

3. The laser cleaning method according to claim 1 or 2, wherein In the extension direction of the main optical axis, the distance from the light beam width at the light outlet of the laser cleaning head to the center point of all the basic sensors is defined as H , if the light beam width at the light outlet of the laser cleaning head is closer to the calibration plane than the center point of all the basic ranging sensors, then L = f + H , if the center point of all the basic ranging sensors is closer to the calibration plane than the light beam width at the light outlet of the laser cleaning head, then L = f - H , if the center point of all the basic ranging sensors is coplanar with the light beam width at the light outlet of the laser cleaning head, then H = 0, L = f ; in the formula, f is the focal length of the laser cleaning head.

4. The laser cleaning method according to claim 1 or 2, wherein The basic ranging sensors are distributed at the vertices of the same polygon.

5. The laser cleaning method of claim 4, wherein the laser beam is focused to a spot size of 0.1 to 100 microns. The number of laser cleaning heads is one, and the center point of the polygon is located on the main optical axis of the laser cleaning head; or the number of laser cleaning heads is at least two, and the center point of the polygon is located on the central axis of the main optical axes of all the laser cleaning heads.

6. The laser cleaning method of claim 4, wherein the laser beam has a wavelength of 1.06 μm. The number of basic ranging sensors is three, and the three basic ranging sensors are located at the three vertices of an equilateral triangle, respectively.

7. The laser cleaning method according to claim 1 or 2, wherein the laser beam is a pulsed laser beam. A plurality of auxiliary extended ranging sensors are also installed on the mounting plane, the ranging direction of the auxiliary extended ranging sensors is parallel to the main optical axis, and the auxiliary extended ranging sensors are arranged around the closed figure connected by the basic ranging sensors, so as to predict the shape of the surface of the workpiece that needs to be cleaned next by the data measured by the auxiliary extended ranging sensors during laser cleaning.

8. The laser cleaning method of claim 4, wherein the laser beam has a wavelength of 1.06 μm. A plurality of auxiliary extended ranging sensors are also installed on the mounting plane, the ranging direction of the auxiliary extended ranging sensors is parallel to the main optical axis, and the auxiliary extended ranging sensors are located on at least two adjacent sides of the four sides of the figure surrounded by the basic ranging sensors, on each side where the auxiliary extended ranging sensors are located, part of the auxiliary extended ranging sensors and part of the basic ranging sensors surround a polygon which is the same as the figure surrounded by all the basic ranging sensors and coincides with one side of the figure surrounded by all the basic ranging sensors.

9. The laser cleaning method according to claim 1 or 2, wherein Before laser cleaning, the laser cleaning head is moved along the outer contour of the workpiece in the x and z directions, and the outer contour of the workpiece is recorded. During cleaning, the laser cleaning head is controlled to perform S-shaped reciprocating motion in the x and z directions to clean the entire surface within the outer contour, and the y direction position and the tilt angle of the laser cleaning head are controlled to ensure that the included angle between the measurement plane and the calibration plane is always less than 5°, and 0.95L≤ l 均 ≤1.05L.

10. A laser cleaning apparatus comprising a multi-axis industrial robot and a laser cleaning head mounted on the multi-axis working robot and serving as an end effector, the laser cleaning head being provided with a distance measuring sensor which moves in synchronism with the laser cleaning head and serves for focusing, characterized in that The number of ranging sensors is at least three, and the ranging sensors are non-collinearly arranged on the same mounting plane of the multi-axis industrial robot, the mounting plane is perpendicular to the main optical axis of the laser cleaning head, the ranging direction of the ranging sensors is parallel to the main optical axis, and the multi-axis industrial robot is used for synchronously adjusting the three-dimensional coordinates and the inclination angles of the laser cleaning head and the ranging sensors, so as to realize the laser cleaning method of any one of claims 1-9.

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