Energy distribution adjustable laser processing system based on free-form surface and application

Abstract

The energy distribution adjustable laser processing system based on the free-form surface comprises a processing lens, a laser generation array is arranged at the front end of a light inlet, and a homogenizing shaping assembly based on the free-form surface is arranged between the light inlet and a light outlet of the processing lens; an industrial camera on the front side of the machining lens collects surface information of the to-be-machined workpiece; a thermal imager on the workpiece side collects the surface temperature of the workpiece in the machining process; the controller is used for acquiring output light spot information and partition characteristics of the workpiece, matching light spots with partitions, controlling on-off of the laser generation array and adjusting output of the laser generation array based on feedback of the thermal imager; the method is applied to plane and / or workpiece machining with a free-form surface. The surface temperature uniformity of the complex component is ensured, the surface hardness of the workpiece and the uniformity of structure distribution are improved, and the method is suitable for various machining devices; the light spot energy of each unit is uniformly distributed, the light path is simplified, higher power can be borne, and the interference influence between light beams is reduced; and independent control of unit light spot energy is realized.

Description

Technical Field

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

[0002] Laser processing uses the energy of light to achieve a very high energy density on the processing plane through changes in the mirror group. It can achieve the purpose of processing a variety of metals and non-metals, and can also process materials with high hardness, high brittleness and high melting point.

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

[0004] A Chinese patent with publication number 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 flat-top spot; however, the structure of the device is relatively complex, and although the large-area flat-top spot produced can meet the processing requirements of large components, this type of spot cannot meet the requirement of uniform surface temperature during processing, which will make the performance of the processed part unstable.

[0005] There is also the "Research on Laser Cladding Rectangular Homogenized Spot Optical System" proposed by Huazhong University of Science and Technology, which can transform the circular Gaussian spot into a large flat-top rectangular spot, greatly improving the processing efficiency. However, this type of spot is prone to overheating or underheating when processing complex components, resulting in uneven structure of the strengthening layer and unstable mechanical properties. At the same time, it can only realize one laser processing technology and has poor compatibility.

[0006] As the above research theory shows, the conventional transmission-type homogenization and shaping method requires the setting of multiple lenses, and the optical path setting is complicated. It is also necessary to consider that there should be no interference between the optical paths, otherwise it will directly affect the forming effect of the laser spot. At the same time, the transmission-type homogenization and shaping method has high requirements for the output power control of the laser. 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 comprising:

[0009] 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;

[0010] An industrial camera, arranged in front of the processing lens, is used to collect surface information of the workpiece to be processed;

[0011] A thermal imager, arranged on the side of the workpiece, for collecting the surface temperature of the workpiece during the processing;

[0012] 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.

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

[0014] Preferably, the controller matches the light spot and the partition including the following steps:

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

[0016] S1.2 Obtain the partitions of the workpiece to be processed based on the industrial camera and record the area of ​​each partition ;

[0017] 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.

[0018] Preferably, adjusting the output of the laser generating array based on thermal imager feedback comprises the following steps:

[0019] 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 ;

[0020] S2.2 Based on T iWith the preset temperature threshold T0, if If it is greater than the preset value, proceed to the next step, otherwise repeat S2.1;

[0021] 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.

[0022] Preferably, the light input port is an array-type light input 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 input port and the homogenizing and shaping component.

[0023] Preferably, the homogenization and shaping component is a free-form surface optical component, which includes a plurality of reflective mirrors, all of which correspond to the laser generating array one by one, and the angle α between the normal of all of the reflective mirrors and the incident light satisfies 0<α<90°.

[0024] In the present invention, the free-form surface refers to that the mirror surface of the reflector 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 of the reflective mirror surfaces is obtained by processing and acquiring the surface distribution function after calculating the surface distribution function through the Gerchberg-Saxton phase retrieval algorithm according to the irradiance far-field data of the incident light of the corresponding laser generating array and the set output irradiance distribution.

[0026] In the present invention, an infrared camera is used to capture the light spot projected on a light screen, and 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 calculated, and the light source modeling is completed. Then, according to the required splicing form and size of the light spot, the surface distribution of the free-form surface is obtained through an algorithm, and finally, surface engraving is achieved through micro-nano engraving.

[0027] Preferably, α is 45°.

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

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

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

[0031] 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;

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

[0033] 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;

[0034] 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.

[0035] The present invention relates to a laser processing system with adjustable energy distribution based on free-form surfaces and its application. The system comprises a processing lens, a laser generating array is arranged at the front end of a light inlet of the processing lens, and a homogenizing and shaping component based on the free-form surface is arranged between the light inlet and the light outlet of the processing lens; an industrial camera is arranged at the front side of the processing lens to collect surface information of a workpiece to be processed; a thermal imager is arranged at the workpiece side to collect the surface temperature of the workpiece during processing; a controller obtains the output light spot information of the homogenizing and shaping component based on the free-form surface 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; and the system is applied to the processing of planes and / or workpieces with free-form surfaces.

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

[0037] (1) The light spot is arrayed in two dimensions, and the power density of each unit light spot can be independently and steplessly adjusted, so that the energy distribution and shape of the light spot array can be precisely customized according to the shape of the complex curved surface. This can not only ensure the uniformity of the surface temperature of complex components, improve the surface hardness and uniformity of the structure distribution of the workpiece, but also be suitable for a variety of processing equipment;

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

[0039] (3) Independent control of the unit spot energy is achieved through an external controller. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0041] Figure 2 It is the working flow chart of the controller in the application of the present invention;

[0042] Figure 3 This is a schematic diagram of the structure of the lens in the present invention without the outer cover;

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

[0044] Figure 5 A schematic diagram of the effect of achieving light emission or non-light emission of a unit light spot in different areas in an embodiment of the present invention;

[0045] Figure 6 Schematic diagram of the effect of achieving unit spot power adjustment at different heights on the workpiece surface in an embodiment of the present invention, wherein (a) is the original workpiece, (b) is a top-down perspective of the original workpiece, (c) is a schematic diagram of light spots in different areas of the workpiece being processed, and (d) is a top-down perspective of (c). DETAILED DESCRIPTION

[0046] The present invention is further described in detail below 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 comprising:

[0048] A processing lens 11, a laser generating array 3 is provided at the front end of the light inlet 1 of the processing lens 11, and a homogenizing and shaping component 4 based on a free-form surface is provided between the light inlet 1 and the light outlet 2 of the processing lens 11;

[0049] An industrial camera 12, arranged in front of the processing lens 11, for collecting surface information of the workpiece 13 to be processed;

[0050] A thermal imager 14, arranged on the side of the workpiece 13, for collecting the surface temperature of the workpiece 13 during the processing;

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

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

[0053] First, the arrangement and size of the laser spot are obtained according to the laser generating array 3, and the unit size of the temperature acquisition area of ​​the thermal imager 14 is set. Here, the unit size is uniformly adjusted to be consistent with the unit spot size, and the area is ,At the same time, the temperature collection area of ​​the thermal imager 14 corresponds to the optical fiber output of the laser generating array 3, and both are numbered 1 to n;

[0054] The machining start coordinate (x0, 0) and the machining stroke x are set according to the size of the workpiece 13.

[0055] Then, the preparatory work is performed. When the workpiece 13 reaches the set starting coordinates, all optical fibers of the laser generating array 3 are turned on, and the image recognition system of the industrial camera 12 is turned on at the same time. The video taken by the industrial camera 12 is processed online, and the image of the workpiece to be processed in each unit area is gray-processed according to the set area division size and form, and the Canny algorithm is used to detect edges and extract their contours.

[0056] The on / off control of a single optical fiber in the laser generating array 3 comes from the matching of the light spot and the partition by the controller 15, and includes the following steps:

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

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

[0059] S1.3 If If it is less than a preset value, the output of the corresponding optical fiber of the laser generating array 3 is turned off when the corresponding output light spot coincides with the partition; otherwise, the corresponding optical fiber of the laser generating array 3 keeps outputting when the corresponding output light spot coincides with the partition.

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

[0061] The adjustment of a single optical fiber in the laser generating array 3 is achieved by adjusting the output of the laser generating array 3 through feedback from the thermal imager 14, including the following steps:

[0062] S2.1 When any output spot of the laser generating array 3 that is not turned off coincides with the corresponding partition, calculate the average temperature T of the partition. i ;

[0063] Here, the thermal imager 14 is used to monitor and collect the surface temperature of each laser heat treatment zone in real time, and the surface temperature of each laser heat treatment zone is measured according to the temperature transfer function. Calculate the temperature of the processing area. Generally, the temperature transfer function of laser processing is a first-order transfer function, satisfying

[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, and s is a complex variable, which represents the frequency response of the system;

[0066] The data collected by the thermal imager 14 was subjected to curve fitting by Newton interpolation method, and K=0.217, T=2.84 were obtained;

[0067] 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;

[0068] The preset value here is generally set to 2%, which means that fuzzy PID control is required;

[0069] 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 3.

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

[0071]

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

[0073] Fuzzy PID adds a fuzzy module to the traditional PID control system, taking the deviation e and the rate of change of the deviation ec as input, and using fuzzy control rules to output , and Adjustment amount , and , so as to adjust the PID parameters in real time online to meet the following requirements:

[0074]

[0075]

[0076]

[0077] When the area temperature T fed back by the thermal imager 14 i When the start-up requirements of the control system are met, the fuzzy PID control module starts working to control the laser power. At the same time, the thermal imager 14 monitors the temperature in real time and provides feedback, realizing the real-time input of the temperature deviation e and the rate of change of the deviation ec, thereby adjusting the PID parameters online in real time to achieve automatic temperature control.

[0078] Finally, when the workpiece reaches the coordinate (x0+x, 0), turn off the laser.

[0079] The lens of the processing head includes a light inlet 1 and a light outlet 2, a laser generating array 3 is provided at the front end of the light inlet 1, and a matching homogenization and shaping component 4 based on a free-form surface is provided in sequence between the light inlet 1 and the light outlet 2; a controller is provided in conjunction with the laser generating array 3;

[0080] The light beam 6 output by the laser processing head is shaped by the homogenization and shaping component 4 based on the free-form surface.

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

[0082] A collimator 7 corresponding to and coaxial with the laser generating array 3 is provided between the light inlet 1 and the homogenizing and shaping assembly 4 .

[0083] An output protection mirror is provided in conjunction with the light outlet 2 .

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

[0085] In the present invention, each laser beam 6 input at the light entrance 1 is collimated by the collimator 7, and a fixing plate with a water cooling pipe is provided in conjunction with the collimator 7, which fixes the collimator 7 and makes the collimator 7 parallel and the input and output are in the same plane.

[0086] In the present invention, each laser beam 6 is subjected to a process of regularizing the output spot by using a homogenizing and shaping component 4 based on a free-form surface.

[0087] In the present invention, an output protection mirror is provided at the light outlet 2 to ensure the cleanliness of the entire laser head cavity and prevent dust and splashing from affecting the overall optical path.

[0088] In the present invention, the controller is used to realize the surface temperature control of the workpiece 13 to be processed. In practical applications, an infrared thermal imager can be set up to monitor and transmit the surface temperature to the controller in real time, and then compared with the threshold set in the controller, so as to control each sub-controller to adjust the unit laser power. The sub-controllers are respectively set in a one-to-one correspondence with the laser generator.

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

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

[0091] Any of the reflective mirror surfaces 41 is obtained by processing and obtaining a surface distribution function by calculating the surface distribution function through the Gerchberg-Saxton phase recovery algorithm according to the irradiance far-field data of the incident light of the corresponding laser generating array 3 and the set output irradiance distribution.

[0092] α is 45°.

[0093] In the present invention, specifically, each laser beam 6 in the array is emitted to the free-form surface optical component, and after passing through the corresponding reflective mirror surface 41 on the free-form surface optical component, it is reflected to the surface of the workpiece 13 under a slight difference in convexity and concavity. All laser beams 6 discretely form a rectangular light spot with uniform energy distribution through the corresponding reflective mirror surface 41. At the same time, in order to achieve specific splicing of the array, the reflective mirror surfaces 41 corresponding to each light beam 6 cooperate with each other to form a whole, so that each discrete flat-top light spot converges into an array light spot of a specific size and shape, thereby achieving the shaping and homogenization of the light 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 component is adjustable, and different application effects can be obtained by adjusting the position of the light outlet 2 accordingly; in conventional applications, selecting α as 45° can obtain the technical effect of horizontal incidence and vertical output.

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

[0096] The application is described below in conjunction with an embodiment. The application includes the following steps:

[0097] S3.1 Clean the surface of any workpiece 13 to be processed, ensure that its surface meets the processing requirements, and place it on the processing platform; divide the processing area into zones, and set the arrangement of the laser generating array 3 according to the zone conditions, ranging from 1×1 to 3×5;

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

[0099] S3.3 The array collimated parallel light beam 6 is adjusted by the homogenizing and shaping component 4 based on the free surface, so that the Gaussian distribution spot is discretized into a spot with uniform energy distribution, and finally the array light beam 6 with each unit spot being a specific shape is formed, and then it is reflected by the homogenizing and shaping component 4 based on the free surface, and output through the light outlet 2, so as to form an array light spot arranged in a set shape in the area to be processed;

[0100] S3.4 According to the changes of the area to be processed during the processing, the controller independently controls each laser beam 6 of the laser generating array 3, so as to obtain the corresponding array light spot 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, the free-form surface design is performed, that is, the light intensity distribution of the laser beam 6 used for the array is captured by an infrared camera, and a light source model is established. The corresponding free-form surface shape is obtained by calculation through the Gerchberg-Saxton phase retrieval algorithm, and then S3.2 is performed.

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

[0103] When the surface shape of the workpiece 13 entering the area covered by the array spot changes, the controller analyzes the temperature data of the thermal imager to change the arrangement and / or shape of the spot 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 that the surface temperature rises, 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 that the surface temperature decreases, 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 coverage area of ​​the array spot. In the embodiment, the array laser (including the laser generator and the lens) arranges the 10 divergent laser beams 6 emitted from the 2kW laser generator in a 2×5 rectangular array, and forms an array collimated parallel beam 6 after being transformed by the corresponding collimator 7, and then forms a 2×5 closely packed rectangular array beam 6 through the free surface homogenization and shaping module, which can realize 2×5 rectangular spots with a side length of 15mm in a closely packed array, and the energy of each unit spot is evenly distributed and the energy density is individually adjustable.

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

[0108] like Figure 6 As shown, still taking a rectangular spot with a side length of 15 mm as an example, the laser spot array is set to 2×5 according to the surface size of the workpiece 13 to be processed. As the workpiece 13 moves, the laser radiates to the concave surface, and the corresponding unit laser power is increased. As the laser irradiates to 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 a flat or curved workpiece 13 .

[0110] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which 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; 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: The homogenization and shaping component is a free-form surface optical component, which includes a plurality of reflective mirrors, all of which correspond to the laser generating array one by one, and the angle α between the normal of all of the reflective mirrors and the incident light satisfies 0<α<90°.

6. The laser processing system with adjustable energy distribution based on free-form surface according to claim 5, 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.

7. The laser processing system with adjustable energy distribution based on free-form surface according to claim 5, characterized in that: α is 45°.

8. 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.

9. 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 8, characterized in that: Applicable to the machining of flat and / or curved workpieces.

10. The use according to claim 9, 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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