A Laser Processing System with Adjustable Energy Distribution Based on Free-Form Surfaces and Its Application

Abstract

The present invention relates to a laser processing system with adjustable energy distribution based on a free-form surface and its application, including a processing lens. A laser generation array is provided at the front end of the light input port. A homogenizing and shaping component based on a free-form surface is provided between the light input port and the light output port of the processing lens. An industrial camera on the front side of the processing lens collects the surface information of the workpiece to be processed. A thermal imager on the workpiece side collects the surface temperature of the workpiece during the processing. The controller obtains the output spot information and the partition characteristics of the workpiece, matches the spots and partitions, controls the opening and closing of the laser generation array, and adjusts the output of the laser generation array based on the feedback of the thermal imager. It is applied to the processing of workpieces with flat surfaces and / or free-form surfaces. The present invention ensures the uniformity of the surface temperature of complex components, improves the hardness of the workpiece surface and the uniformity of the tissue distribution, and is applicable to various processing equipment; the spot energy of each unit is evenly distributed, the optical path is simplified, it can withstand a greater power, and the influence of beam interference is reduced; independent control of the spot energy of each unit is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of brazing or desoldering; welding; cladding or plating by brazing or welding methods; local heating cutting, such as flame cutting; and laser beam processing, and particularly relates to a laser processing system with adjustable energy distribution based on a free-form surface and its applications. Background Art

[0002] Laser processing utilizes the energy of light, and through the change of a mirror group, a very high energy density can be achieved on the processing plane, which can achieve the purpose of various processing of a variety of metals and non-metals, and can also process materials with high hardness, high brittleness and high melting point.

[0003] During the laser processing process, the processing of a class of complex components is relatively difficult. These complex components include, but are not limited to, blades, tracks, bearings, etc., which have asymmetric heat transfer characteristics such as variable cross-sections, special-shaped surfaces, and variable curvatures. After being subjected to service conditions such as alternating heavy loads, frequent impacts, and fatigue wear, how to improve their surface performance and service life through laser processing has become an urgent problem to be solved. In this regard, the current main treatment method is laser surface strengthening.

[0004] Chinese Patent with Publication No. CN117464176A discloses "a laser optical path structure with uniform laser spot energy density", which includes a first shaping lens, a second shaping lens and a third shaping lens arranged coaxially; the incident Gaussian distribution circular spot laser passes through the three lenses in sequence, and can be shaped into a rectangular or strip-shaped flat-top spot; however, the structure of this device is relatively complex, and although the large-area flat-top spot generated can meet the processing requirements of large components, such spots cannot meet the requirements of surface temperature uniformity during the processing process, which will make the performance of the processed parts unstable.

[0005] Another research "Research on the Optical System of Laser Cladding Rectangular Homogenized Spot" proposed by Huazhong University of Science and Technology can transform a circular Gaussian spot into a flat-top rectangular large spot, greatly improving the processing efficiency. However, such spots are prone to overheating or underheating phenomena when processing complex components, resulting in non-uniformity of the strengthening layer structure and instability of mechanical properties. At the same time, it can only implement one laser processing technology and has poor compatibility.

[0006] As in the above research theory, the existing transmission-type homogenization and shaping methods require the setting of multiple lenses, the optical path setting is complex, and it is also necessary to consider that interference effects cannot occur between the optical paths, otherwise it will directly affect the shaping effect of the laser spot; at the same time, the transmission-type homogenization and shaping methods have high requirements for the control of the laser output power, and once the control is improper, it is easy to damage the lens. Summary of the Invention

[0007] The present invention solves the problems existing in the prior art and provides a laser processing system with adjustable energy distribution based on a free-form surface and its application.

[0008] The technical solution adopted by the present invention is a laser processing system with adjustable energy distribution based on a free-form surface. The laser processing system includes:

[0009] A processing lens, a laser generation array is provided at the front end of the light input port of the processing lens, and a homogenization and shaping component based on a free-form surface is provided between the light input port and the light output port of the processing lens;

[0010] An industrial camera is provided in cooperation with the front side of the processing lens for collecting the surface information of the workpiece to be processed;

[0011] An infrared thermal imager is provided in cooperation with the workpiece side for collecting the surface temperature of the workpiece during the processing;

[0012] A controller is provided in cooperation with the laser generation array, the industrial camera and the infrared thermal imager; the controller obtains the output spot information of the homogenization and shaping component based on the free-form surface and the partition characteristics of the workpiece, matches the spot and the partition, controls the opening and closing of the laser generation array, and adjusts the output of the laser generation array based on the feedback of the infrared thermal imager.

[0013] In the present invention, although the shape of the spot cannot be adjusted, the change of the array spot can be realized by adjusting the laser power.

[0014] Preferably, the controller matching the spot and the partition includes the following steps:

[0015] S1.1 Adjust each output spot of the corresponding laser generation array so that its area is ;

[0016] S1.2 Based on the industrial camera, obtain the partition of the workpiece to be processed and record the area of each partition ;

[0017] S1.3 If is less than the preset value, then when the corresponding output spot coincides with the partition, turn off the output of the corresponding optical fiber of the laser generation array, otherwise when the corresponding output spot coincides with the partition, the corresponding optical fiber of the laser generation array remains output.

[0018] Preferably, adjusting the output of the laser generation array based on the feedback of the infrared thermal imager includes the following steps:

[0019] S2.1 When any output spot of the unclosed laser generation array coincides with the corresponding partition, calculate the average temperature T of the partition i ;

[0020] S2.2 Based on T iWith a preset temperature threshold T 0 , if is greater than the preset value, proceed to the next step; otherwise, repeat S2.1;

[0021] S2.3 Use fuzzy PID to adjust the PID parameters online in real time and feedback them to the corresponding optical fibers of the laser generation array.

[0022] Preferably, the light inlet is an array - type light inlet channel corresponding one - to - one with the laser generation array; a collimating mirror corresponding one - to - one with the laser generation array and coaxial is provided between the light inlet and the homogenizing and shaping component.

[0023] Preferably, the homogenizing and shaping component is a free - form optical element, and the free - form optical element includes a plurality of reflecting mirrors. All the reflecting mirrors correspond one - to - one with the laser generation array, and the angle α between the normal of all the reflecting mirrors and the incident light satisfies 0 < α < 90°.

[0024] In the present invention, the free - form surface means that the mirror surface of the reflecting mirror is a free - form surface. Since the light field irradiation information of each optical fiber is different, the free - form surface corresponding to each optical fiber is different.

[0025] Preferably, any one of the reflecting mirrors is obtained by processing after calculating the surface distribution function through the Gerchberg - Saxton phase retrieval algorithm according to the far - field irradiance data of the incident light of the corresponding laser generation array and the set output irradiance distribution.

[0026] In the present invention, the light spot projected on the light screen is captured by an infrared camera. The distances between the light screen and the light outlet are 300, 500, and 1000 mm respectively. The far - field energy distribution of the optical fiber is measured to complete the light source modeling. Then, according to the required light spot splicing form and size, the surface distribution of the free - form surface is obtained through an algorithm, and finally, the surface engraving is realized through micro - nano engraving.

[0027] Preferably, α is 45°.

[0028] Preferably, an output protection mirror is provided in cooperation with the light outlet.

[0029] An application of the laser processing system with adjustable energy distribution based on free - form surface is applied to the processing of planar and / or curved workpieces.

[0030] Preferably, the application includes the following steps:

[0031] S3.1 Clean the surface of any workpiece to be processed and place it on the processing platform; partition the area to be processed and set the arrangement of the laser generation array according to the partition situation;

[0032] S3.2 All the laser beams generated by the laser generation array are arranged in an array and form an array of collimated parallel beams;

[0033] S3.3 The array of collimated parallel beams is adjusted by a homogenizing and shaping component based on a free-form surface, so that the Gaussian-distributed light spot is discretized into a light spot with a uniform energy distribution. After finally forming an array beam with each unit light spot being of a specific shape, it is reflected by the homogenizing and shaping component based on a free-form surface and output through the light outlet, forming an array of light spots arranged in a set shape in the area to be processed;

[0034] S3.4 According to the change of the area to be processed during the processing, the controller independently controls each laser beam of the laser generation array, and then obtains the corresponding array of light spots on each area to be processed.

[0035] The present invention relates to a laser processing system and application with adjustable energy distribution based on a free-form surface. The system includes a processing lens. A laser generation array is provided at the front end of the light inlet of the processing lens. A homogenizing and shaping component based on a free-form surface is provided between the light inlet and the light outlet of the processing lens; An industrial camera is arranged on the front side of the processing lens to collect the surface information of the workpiece to be processed; A thermal imager is provided on the workpiece side to collect the surface temperature of the workpiece during the processing; The controller obtains the output light spot information of the homogenizing and shaping component based on a free-form surface and the zoning characteristics of the workpiece, matches the light spot and the zoning, controls the opening and closing of the laser generation array, and adjusts the output of the laser generation array based on the feedback of the thermal imager; It is applied to the processing of flat and / or workpieces with free-form surfaces.

[0036] The beneficial effects of the present invention are as follows:

[0037] (1) Make the light spot two-dimensionally arrayed, and the power density of each unit light spot can be independently and steplessly adjusted, so that the energy distribution and the shape of the light spot array can be accurately customized according to the shape of the complex surface. It can not only ensure the uniformity of the surface temperature of the complex component, improve the uniformity of the surface hardness and tissue distribution of the workpiece, but also be applicable to a variety of processing equipment;

[0038] (2) For the homogenizing and shaping process of the laser light spot, a free-form surface homogenizing and shaping module is used to realize the customization of the unit light spot shape and the splicing shape, and the energy of each unit light spot is evenly distributed. The optical path is simplified, and the reflective homogenizing and shaping method can withstand a greater power and reduce the interference effect between the beams;

[0039] (3) Through an external controller, the independent control of the energy of the unit light spot is realized. Description of the Drawings

[0040] Figure 1 It is a schematic diagram of the laser processing system in the present invention;

[0041] Figure 2 The working flowchart of the controller in the application of the present invention;

[0042] Figure 3 The structural schematic diagram of removing the outer cover of the lens in the present invention;

[0043] Figure 4 The optical path schematic diagram of the lens in the present invention;

[0044] Figure 5 The effect schematic diagram of realizing the light output or non - light output of the unit light spot for different regions in the embodiment of the present invention;

[0045] Figure 6 The effect schematic diagram of realizing the adjustment of the unit light spot power for different heights on the surface of the workpiece in the embodiment of the present invention, where (a) is the original workpiece, (b) is the top - view perspective of the original workpiece, (c) is the schematic diagram of the light spots in different regions of the workpiece during processing, and (d) is the top - view perspective of (c). Detailed implementation manners

[0046] The following further describes the present invention in detail in conjunction with embodiments, but the protection scope of the present invention is not limited thereto.

[0047] The present invention relates to a laser processing system with adjustable energy distribution based on a free - form surface. The laser processing system includes:

[0048] A processing lens 11, a laser generation array 3 is provided at the front end of the light input port 1 that cooperates with the processing lens 11, and a homogenization and shaping component 4 based on a free - form surface is provided between the light input port 1 and the light output port 2 of the processing lens 11;

[0049] An industrial camera 12, which is cooperatively arranged on the front side of the processing lens 11 and is used to collect the surface information of the workpiece 13 to be processed;

[0050] An infrared thermal imager 14, which is cooperatively arranged on the side of the workpiece 13 and is used to collect the surface temperature of the workpiece 13 during the processing;

[0051] A controller 15 is provided in cooperation with the laser generation array 3, the industrial camera 12, and the infrared thermal imager 14; the controller 15 obtains the output light spot information of the homogenization and shaping component 4 based on a free - form surface and the zoning characteristics of the workpiece 13, matches the light spots and the zones, controls the opening and closing of the laser generation array 3, and adjusts the output of the laser generation array 3 based on the feedback of the infrared thermal imager 14.

[0052] Specifically, the controller 15 is realized by controlling the laser generation array 3, which includes the opening and closing of a single optical fiber in the laser generation array 3 and the adjustment (intermediate state) of a single optical fiber in the laser generation array 3.

[0053] First, obtain the arrangement and size of the laser spots according to the laser generation array 3, and set the unit size of the temperature acquisition area of the thermal imager 14. Here, the unit size is uniformly adjusted to be the same as the unit spot size, and the area is , and at the same time, the temperature acquisition area of the thermal imager 14 corresponds one-to-one with the fiber output of the laser generation array 3, and both are numbered 1 to n;

[0054] Set the machining start coordinate (x 0 , 0) and the machining stroke x according to the size of the workpiece 13.

[0055] Subsequently, perform preparatory work. When the workpiece 13 reaches the set start coordinate, turn on all the fibers of the laser generation array 3, and at the same time turn on the image recognition system of the industrial camera 12. Process the video captured by the industrial camera 12 online, perform grayscale processing on the images of the workpieces to be processed in each unit area according to the set area division size and form, perform edge detection through the Canny algorithm, and extract its contour.

[0056] The on-off control of a single fiber in the laser generation array 3 comes from the matching of the controller 15 for the spots and partitions, including the following steps:

[0057] S1.1 Adjust each output spot of the corresponding laser generation array 3 so that its area is ;

[0058] S1.2 Based on the industrial camera 12, obtain the partitions of the workpiece 13 to be processed, and record the area of each partition ;

[0059] S1.3 If is less than the preset value, then turn off the output of the corresponding fiber of the laser generation array 3 when the corresponding output spot coincides with the partition, otherwise keep the output of the corresponding fiber of the laser generation array 3 when the corresponding output spot coincides with the partition.

[0060] In the present invention, generally for , set the preset threshold to 10%, that is, when , considering that the required laser processing area is too small, the laser output of the fiber corresponding to the corresponding processing partition is turned off, otherwise the corresponding fiber keeps the output.

[0061] The adjustment of a single fiber in the laser generation array 3 is achieved by the thermal imager 14 feeding back to adjust the output of the laser generation array 3, including the following steps:

[0062] S2.1 When any output spot of the unclosed laser generation array 3 coincides with the corresponding partition, calculate the average temperature T of the partition i ;

[0063] Here, the surface temperature of each zone during laser heat treatment is monitored and collected in real time by the thermal imager 14, and the temperature of the processing area is calculated according to the temperature transfer function The temperature transfer function for general laser processing is a first-order transfer function and satisfies

[0064]

[0065] In the formula, K is the system gain coefficient, that is, the output value after the system stabilizes; T is the time constant, that is, the time required for the system to rise to 0.623K; s is a complex variable representing the frequency response of the system;

[0066] The data collected by the thermal imager 14 is curve-fitted by the Newton interpolation method to obtain K = 0.217 and T = 2.84;

[0067] S2.2 Based on T i and the preset temperature threshold T 0 , if is greater than the preset value, then proceed to the next step; otherwise, repeat S2.1;

[0068] The preset value here is generally set to 2%, that is, fuzzy PID control needs to be adopted;

[0069] S2.3 Use fuzzy PID to adjust the PID parameters online in real time and feedback to the corresponding optical fibers of the laser generation array 3.

[0070] In the present invention, the system adopts the fuzzy PID control method, adding a fuzzy module on the basis of the traditional PID control to enhance the self-adaptability of the system, reduce the rise time and adjustment time of the system, and at the same time reduce the steady-state error; the control output of the PID controller satisfies

[0071]

[0072] In the formula, e(t) is the deviation between the set value and the measured value, , and are the proportional gain, integral coefficient and differential coefficient respectively;

[0073] The fuzzy PID adds a fuzzy module to the traditional PID control system, taking the deviation e and the change rate ec of the deviation as inputs, and using the fuzzy control rules to output , and adjustment amounts of , and , so as to adjust the PID parameters online in real time, respectively satisfying

[0074]

[0075]

[0076]

[0077] When the regional temperature T i fed back by the thermal imager 14 reaches the startup requirement of the control system, the fuzzy PID control module starts to work to control the laser power. At the same time, the thermal imager 14 monitors the temperature in real time and gives feedback, realizing the real-time input of the temperature deviation e and the change rate ec of the deviation, so as to adjust the PID parameters online in real time and realize the automatic control of the temperature.

[0078] Finally, when the workpiece reaches the coordinate (x 0 +x, 0), the laser is turned off.

[0079] The lens of the processing head includes a light input port 1 and a light output port 2. A laser generating array 3 is provided at the front end of the light input port 1 in cooperation. A homogenizing and shaping component 4 based on a free-form surface is sequentially provided between the light input port 1 and the light output port 2; a controller is provided in cooperation with the laser generating array 3;

[0080] The homogenizing and shaping component 4 based on a free-form surface realizes the shaping of the light beam 6 output by the laser processing head.

[0081] The light input port 1 is an array-type light input channel corresponding one-to-one to the laser generating array 3.

[0082] A collimating mirror 7 corresponding one-to-one to the laser generating array 3 and coaxial is provided between the light input port 1 and the homogenizing and shaping component 4.

[0083] An output protection mirror is provided in cooperation with the light output port 2.

[0084] In the present invention, the laser generating array 3 is an array composed of more than 1 fiber laser generator. The light output end faces of all the laser generators are in a plane and are arranged in a set array. Generally speaking, the set array range of the laser generators is 1×1~3×5; the light input port 1 is connected to the optical fiber through a QBH connector 5 for accessing the corresponding light beam 6 one-to-one.

[0085] In the present invention, each light beam 6 input at the light input port 1 is collimated by the collimating mirror 7. At the same time, a fixing plate with a water cooling pipe is arranged in cooperation with the collimating mirror 7, which plays a role in fixing the collimating mirror 7, making the collimating mirror 7 parallel and the input and output in the same plane respectively.

[0086] In the present invention, each light beam 6 is processed by the homogenizing and shaping component 4 based on a free-form surface to regularize the output light spot.

[0087] In the present invention, by providing an output protection mirror at the light output port 2, the cleanliness inside the entire laser head cavity is ensured, preventing dust and splashes from affecting the overall optical path.

[0088] In the present invention, the controller is used to control the surface temperature of the workpiece 13 to be processed. In practical applications, an infrared thermal imager can be installed to monitor the surface temperature in real time and transmit it to the controller, which compares it with the threshold set in the controller, thereby controlling each sub-controller to adjust the unit laser power. The sub-controllers are respectively arranged in one-to-one correspondence with the laser generators.

[0089] During the implementation of the present invention, the laser generation array 3 is connected to the light input port 1 through a QBH connector 5. The emitted laser beam 6 is transformed into a parallel laser beam array with a circular cross-section through the array of collimating mirrors 7. After the parallel laser beam array is incident on the homogenizing and shaping component 4 based on a free-form surface, an array laser with a specific overlapping shape and spot shape is formed through the reflection of the free-form surface.

[0090] The homogenizing and shaping component 4 is a free-form surface optical element, which includes a plurality of reflecting mirrors 41. All the reflecting mirrors 41 correspond to the laser generation array 3 one by one, and the angle α between the normal of all the reflecting mirrors 41 and the incident light satisfies 0 < α < 90°.

[0091] Any one of the reflecting mirrors 41 is obtained by calculating through the Gerchberg-Saxton phase retrieval algorithm according to the far-field data of the irradiance of the incident light of the corresponding laser generation array 3 and the set output irradiance distribution, and then processing to obtain the surface distribution function.

[0092] α is 45°.

[0093] In the present invention, specifically, each laser beam 6 in the array is incident on the free-form surface optical element. After being reflected by the corresponding reflecting mirror 41 on the free-form surface optical element, it is reflected to the surface of the workpiece 13 under the tiny uneven differences. All the laser beams 6 form a rectangular spot with uniform energy distribution by dispersing energy through the corresponding reflecting mirrors 41. At the same time, to achieve the specific splicing of the array, the reflecting mirrors 41 corresponding to each beam 6 cooperate with each other as a whole, so that the discrete flat-top spots converge into an array spot with a specific size and shape, realizing the shaping and homogenization of the spot and the simplification of the lens structure.

[0094] In the present invention, considering the diversity of light output, the reflection angle of the free-form surface optical element here is adjustable. At the same time, by correspondingly adjusting the position of the light output port 2, different application effects can be obtained; in conventional applications, choosing α as 45° can obtain the technical effects of horizontal incidence and vertical output.

[0095] The present invention also relates to an application of the laser processing system with adjustable energy distribution based on a free-form surface, which is applied to the processing of workpieces 13 with flat surfaces and / or free-form surfaces.

[0096] The following describes the application in conjunction with embodiments. The application includes the following steps:

[0097] S3.1 Clean the surface of any workpiece 13 to be processed to ensure that its surface meets the processing requirements, and place it on the processing platform; divide the area to be processed, and set the arrangement of the laser generation array 3 according to the division situation, which varies from 1×1 to 3×5;

[0098] S3.2 All the laser beams 6 generated by the laser generation array 3 are arranged in an array to form an array of collimated parallel beams 6. Here, the cross-section of the laser beam 6 is generally circular;

[0099] S3.3 The array of collimated parallel beams 6 is adjusted by the homogenizing and shaping component 4 based on the free-form surface, so that the Gaussian-distributed light spot is dispersed into a light spot with a uniform energy distribution. After finally forming an array beam 6 with specific-shaped unit light spots, it is reflected by the homogenizing and shaping component 4 based on the free-form surface and output through the light outlet 2 to form an array of light spots arranged in a set shape in the area to be processed;

[0100] S3.4 According to the change of the area to be processed during the processing, the controller independently controls each laser beam 6 of the laser generation array 3, and then obtains the corresponding array of light spots on each area to be processed; the independent control here refers to adjusting and controlling the output power of each laser generator to better cope with complex working conditions.

[0101] In the present invention, after completing S3.1, free-form surface design is performed, that is, the light intensity distribution of the laser beam 6 for the array is captured by an infrared camera, a light source model is established, and the corresponding free-form surface shape is obtained through calculation using the Gerchberg-Saxton phase retrieval algorithm, and then S3.2 is executed.

[0102] In the present invention, specifically, in S3.4, the processing platform is controlled to move along a preset direction, the array of light spots maintains its spatial position, and at the same time, a thermal imager is turned on for global temperature monitoring. Generally, the thermal imager is set on the side of the workpiece 13;

[0103] When the surface shape of the workpiece 13 entering the coverage area of the array of light spots changes, the controller analyzes the temperature data of the thermal imager to change the arrangement and / or shape of the light spots output by one or more laser beams 6;

[0104] When there is a protrusion on the surface of the workpiece 13 and the thermal imager detects an increase in surface temperature, the power of the laser beam 6 corresponding to the current position is reduced;

[0105] When there is a depression on the surface of the workpiece 13 and the thermal imager detects a decrease in the surface temperature, the power of the laser beam 6 corresponding to the current position is increased;

[0106] Until the processing platform moves along the preset direction until the workpiece 13 to be processed completely leaves the area covered by the array of light spots. In the embodiment, the array laser (including the laser generator and the lens) arranges 10 divergent laser beams 6 emitted from a 2kW laser generator in a 2×5 rectangular array, and after being transformed by the corresponding collimating mirrors 7 respectively, forms an array of collimated parallel beams 6, and then forms a 2×5 densely arranged rectangular array beam 6 through the free-form surface homogenization and shaping module, which can realize the array dense arrangement of 2×5 rectangular light spots with a side length of 15mm. The energy of each unit light spot is evenly distributed and the energy density can be adjusted individually.

[0107] As Figure 5 shown, corresponding to different positions of the I-shaped workpiece 13, the controller 1 can achieve the effect of the unit light spot emitting light or not emitting light by opening and closing different units, and thus obtain a variety of different overall light spot shapes.

[0108] As Figure 6 shown, still taking the rectangular light spot with a side length of 15mm as an example, according to the surface size of the workpiece 13 to be processed, the laser light spot array is set to 2×5. As the workpiece 13 moves, the laser irradiates the concave surface, and the laser power of the corresponding unit is increased. As the laser irradiates the lower plane, the laser power is increased again to achieve uniform surface temperature of the workpiece 13;

[0109] This method can be applied to the processing of workpieces 13 with flat or curved surfaces.

[0110] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution of the present invention and its inventive concept, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A laser processing system with adjustable energy distribution based on free-form surface, characterized in that: The laser processing system comprises: A processing lens, wherein a laser generating array is provided at the front end of the light inlet of the processing lens, and a homogenizing and shaping component based on a free-form surface is provided between the light inlet and the light outlet of the processing lens; the homogenizing and shaping component is a free-form surface optical component, and the free-form surface optical component includes a plurality of reflecting mirror surfaces, all of which correspond to the laser generating array one by one, and the angle α between the normal of all of the reflecting mirror surfaces and the incident light satisfies 0<α<90°; An industrial camera, arranged in front of the processing lens, is used to collect surface information of the workpiece to be processed; A thermal imager, arranged on the side of the workpiece, for collecting the surface temperature of the workpiece during the processing; A controller is provided in conjunction with the laser generating array, the industrial camera and the thermal imager; the controller obtains the output light spot information of the free-form surface-based homogenizing and shaping component and the partition characteristics of the workpiece, matches the light spot and the partition, controls the opening and closing of the laser generating array, and adjusts the output of the laser generating array based on the feedback of the thermal imager.

2. The laser processing system with adjustable energy distribution based on free-form surface according to claim 1, characterized in that: The controller matches the light spot and the partition including the following steps: S1.1 Adjust each output spot of the corresponding laser generating array so that its area is ; S1.2 Obtain the partitions of the workpiece to be processed based on the industrial camera and record the area of ​​each partition ; S1.3 If If it is less than a preset value, the output of the corresponding optical fiber of the laser generating array is turned off when the corresponding output light spot coincides with the partition; otherwise, the corresponding optical fiber of the laser generating array keeps outputting when the corresponding output light spot coincides with the partition.

3. The laser processing system with adjustable energy distribution based on free-form surface according to claim 2, characterized in that: Adjusting the output of the laser generating array based on thermal imager feedback includes the following steps: S2.1 When any output spot of the laser array that is not turned off coincides with the corresponding partition, calculate the average temperature T of the partition. i ; S2.2 Based on T i With the preset temperature threshold T0, if If it is greater than the preset value, proceed to the next step, otherwise repeat S2.1; S2.3 The PID parameters are adjusted in real time online using fuzzy PID and fed back to the corresponding optical fiber of the laser generating array.

4. According to the laser processing system with adjustable energy distribution based on free-form surface as described in claim 1, the light inlet is an array-type light inlet channel corresponding one-to-one to the laser generating array; a collimating mirror corresponding one-to-one to the laser generating array and coaxial is provided between the light inlet and the homogenizing and shaping component.

5. The laser processing system with adjustable energy distribution based on free-form surface according to claim 1, characterized in that: Any of the reflective mirror surfaces is obtained by processing and obtaining the surface distribution function through calculation using the Gerchberg-Saxton phase recovery algorithm based on the irradiance far-field data of the incident light of the corresponding laser generating array and the set output irradiance distribution.

6. The laser processing system with adjustable energy distribution based on free-form surface according to claim 1, characterized in that: α is 45°.

7. The laser processing system with adjustable energy distribution based on free-form surface according to claim 1, characterized in that: An output protection mirror is provided in conjunction with the light outlet.

8. An application of a laser processing system with adjustable energy distribution based on a free-form surface according to any one of claims 1 to 7, characterized in that: Applicable to the machining of flat and / or curved workpieces.

9. The use according to claim 8, characterized in that: The application comprises the following steps: S3.1 Clean the surface of any workpiece to be processed and place it on the processing platform; divide the processing area into zones and set the arrangement of the laser array according to the zone conditions; S3.2 All laser beams generated by the laser generating array are arranged in an array and form array collimated parallel beams; S3.3 The array collimated parallel beam is adjusted by the homogenizing and shaping component based on the free-form surface, so that the Gaussian distribution spot is discretized into a spot with uniform energy distribution, and finally an array beam with each unit spot of a specific shape is formed. After that, it is reflected by the homogenizing and shaping component based on the free-form surface, output through the light outlet, and forms an array spot arranged in a set shape in the area to be processed; S3.4 Based on the changes of the area to be processed during the processing, the controller independently controls each laser beam of the laser generating array, thereby obtaining the corresponding array light spot on each area to be processed.

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