Water-guided laser automatic online measurement and compensation system and its accuracy compensation method

Abstract

This invention discloses a water-guided laser automatic online measurement and compensation system and its accuracy compensation method. The method includes: determining the planned detection route for the workpiece based on the required machining shape and basic machine tool parameters, and detecting the physical changes of the water jet near the workpiece to obtain initial position information; controlling the relative movement data between the machining unit and the workpiece through a control unit, and obtaining contact point position information based on the difference in the relative movement data; measuring target points with a preset density to obtain target point position information, and performing data fitting on the target point position information to obtain the actual machining shape; determining whether the error data between the actual machining shape and the required machining shape meets a preset accuracy requirement, and performing accuracy compensation based on the judgment result that the preset accuracy requirement is not met to obtain the optimal compensation amount. This invention can solve the problem of reduced machining efficiency and accuracy caused by removing the measurement unit and re-clamping the machine.

Description

Technical Field

[0001] This invention relates to the field of water-guided laser processing technology, and in particular to an automatic online measurement and compensation system for water-guided lasers and its accuracy compensation method. Background Technology

[0002] Water jet guided laser (VLS) is a special processing technology that combines water jet and laser. In VLS, the laser beam is first focused onto a micro-jet of water. Due to the difference in refractive index between water and air, the laser undergoes total internal reflection at the water-air interface, allowing it to propagate forward. The water jet guides the laser beam to the material surface for processing. VLS combines the advantages of conventional laser processing and water jet processing. On one hand, it inherits the advantages of laser cutting, such as no mechanical pressure, no tool wear, and narrow kerf width. On the other hand, it utilizes the excellent heat dissipation and scouring effect of the micro-jet to effectively reduce thermal effects near the cutting area, promptly remove molten slag to prevent contamination and remelting, greatly improving cutting quality and effectively solving the drawbacks of traditional machining and conventional laser processing.

[0003] However, current water-guided lasers lack online inspection methods for workpieces. Because the workpiece needs to be removed for measurement, it requires re-clamping and alignment, impacting processing efficiency. Furthermore, re-clamping inevitably introduces new errors. Summary of the Invention

[0004] The present invention aims to at least partially solve one of the technical problems in the related art.

[0005] Therefore, this invention proposes an automatic online measurement and compensation system for water-guided lasers. Through automatic online measurement and accuracy compensation, the system shortens processing steps, saves manpower and resources, and improves processing accuracy and efficiency.

[0006] Another objective of this invention is to provide an automatic online measurement and compensation method for water-guided lasers.

[0007] To achieve the above objectives, the present invention provides an automatic online measurement and compensation system for water-guided lasers, comprising:

[0008] The processing unit is used to generate a water jet that conducts laser light to provide energy for processing the workpiece.

[0009] Control unit, and control processing unit or workpiece to generate relative movement data;

[0010] The detection unit is used to detect the physical changes of the water jet to obtain position information, and to analyze and process the position information and the relative movement data through the CNC system to obtain the actual processed shape of the workpiece. The error is compared with the preset required processed shape to determine whether to perform accuracy compensation.

[0011] In addition, the water-guided laser automatic online measurement and compensation system according to the above embodiments of the present invention may also have the following additional technical features:

[0012] Furthermore, in one embodiment of the present invention, the control unit is also used to collect information generated by the detection unit.

[0013] Furthermore, in one embodiment of the present invention, the physical changes in the water jet detected by the detection unit include acoustic and optical changes.

[0014] Furthermore, in one embodiment of the present invention, the detection unit is also used to detect the electrical signal between the processing unit and the workpiece.

[0015] To achieve the above objectives, another aspect of the present invention proposes an automatic online measurement and compensation method for water-guided lasers, comprising:

[0016] The planned inspection route for the workpiece is determined based on the required processing shape and basic machine tool parameters, and the initial position information is obtained by detecting the physical changes of the water jet near the workpiece through the detection unit.

[0017] The relative movement data between the processing unit and the workpiece is controlled by the control unit, and the contact point position information is obtained based on the difference information of the relative movement data.

[0018] The contact point position information is measured at a preset density of target points to obtain target point position information, and the target point position information is fitted to obtain the actual processed shape.

[0019] Determine whether the error data between the actual processed shape and the required processed shape meets the preset accuracy requirements, and perform accuracy compensation based on the judgment result that the preset accuracy requirements are not met to obtain the optimal compensation amount.

[0020] The water-guided laser automatic online measurement and compensation system and its accuracy compensation method of this invention can shorten the processing flow, save manpower and material resources, and improve processing efficiency and accuracy through automatic online measurement and accuracy compensation.

[0021] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0022] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0023] Figure 1 This is a schematic diagram of a water-guided laser automatic online measurement and compensation system according to an embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of another water-guided laser automatic online measurement and compensation system according to an embodiment of the present invention;

[0025] Figure 3 This is a flowchart of an automatic online measurement and compensation method for water-guided lasers according to an embodiment of the present invention;

[0026] Figure 4 This is a flowchart illustrating the specific implementation of the water-guided laser automatic online measurement and compensation method according to an embodiment of the present invention. Detailed Implementation

[0027] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0028] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0029] The automatic online measurement and compensation system and method for water-guided lasers according to embodiments of the present invention are described below with reference to the accompanying drawings.

[0030] Figure 1 This is a schematic diagram of the structure of the water-guided laser automatic online measurement and compensation system according to an embodiment of the present invention.

[0031] like Figure 1 As shown, the water-guided laser automatic online measurement and compensation system includes:

[0032] The processing unit 100 is used to generate a water jet that conducts laser light to provide energy for processing the workpiece.

[0033] The control unit 200, and the control processing unit 100 or the workpiece generate relative movement data;

[0034] The detection unit 300 is used to detect the physical changes of the water jet to obtain position information, and to analyze and process the position information and relative movement data through the CNC system to obtain the actual processed shape of the workpiece. The error is compared with the preset required processed shape to determine whether to perform accuracy compensation.

[0035] Specifically, the processing unit 100 is used to generate a water jet that conducts laser light as a processing energy source; the workpiece is the object to be processed and inspected; the detection unit 300 can detect the acoustic, optical and / or electrical characteristics of the water jet; the moving unit causes relative movement between the processing unit 100 and the detection unit 300 during the processing; and the control unit 200 collects information from the detection unit and controls the movement of the moving unit.

[0036] Specifically, the physical changes in the water jet detected by the detection unit 300 include acoustic and optical changes.

[0037] Specifically, the workpiece is fixed, the control unit 200 controls the movement of the processing unit 100, and the detection unit 300 detects the electrical signal between the processing unit 100 and the workpiece.

[0038] In some embodiments of the present invention, such as Figure 2 As shown, the processing unit is fixed, and the control unit 200 controls the movement of the workpiece; the detection unit 300 detects the light signal reflected back to the processing unit 100 by the water jet.

[0039] In some embodiments of the present invention, the workpiece unit has an edge position after each processing step. Through system planning, the water jet can be brought close to the workpiece, and the state changes of the water jet are detected by a detection unit to obtain position information. The measurement principle of the detection unit includes, but is not limited to, detecting the acoustic, optical, and / or electrical characteristics of the water jet. This is because there are significant differences between the water jet in its undisturbed laminar flow state and its deflection, scattering, and / or interruption state caused by interference, such as sound volume, whether the water jet meets the total internal reflection condition, and the conductivity of the water jet. By controlling the relative movement of the processing unit and the workpiece through the control unit, and recording the specific locations where these differences occur during the movement, the position of the contact point can be determined. Next, multiple target point measurements of appropriate density are performed to obtain the position information of the target points, which are automatically recorded and labeled by the CNC system. After the measurement process is completed, the CNC system automatically obtains the set of measured position information points. The workpiece shape can be obtained through data fitting.

[0040] Furthermore, after the automatic online measurement is completed, the CNC system records the set of position information points obtained from the measurement. Next, the actual machining situation needs to be compared with the required dimensions and shape, the error needs to be calculated, and it needs to be checked whether the accuracy requirements are met. If the error meets the machining accuracy requirements, no further accuracy compensation is needed; if the error does not meet the machining accuracy requirements, accuracy compensation is required.

[0041] In some embodiments of the present invention, two methods can be used to calculate the error. The first method involves fitting the set of position information points recorded in the CNC system to obtain a fitted curve, which represents the actual machining size and shape. This curve is then compared with the required size and shape using image processing to obtain the overall image error. Based on the accuracy requirements, the optimal compensation amount is obtained using data processing methods such as the least squares method. The second method involves directly determining the key points of the original required size and shape based on the measured set of position information points. The error of the discrete corresponding key points is used as the discrete error, and the optimal compensation amount is obtained using data processing methods such as the least squares method. Of the two methods, the former, due to its overall data fitting process, can better reflect the actual overall machining situation, but the data processing process is complex and may introduce unnecessary errors. The latter, by utilizing the original measurement data points, simplifies the data processing steps and reduces unnecessary errors.

[0042] Furthermore, this error data is used as a new processing requirement, and combined with the relative position of the electrode wire and the workpiece, a new round of trajectory planning and parameter setting is carried out.

[0043] The water-guided laser automatic online measurement and compensation system according to embodiments of the present invention can shorten the processing flow, save manpower and material resources, and improve processing efficiency and accuracy through automatic online measurement and accuracy compensation.

[0044] To achieve the above embodiments, such as Figure 3 As shown, this embodiment also provides a method for automatic online measurement and compensation of water-guided lasers, including:

[0045] S1, determine the planned inspection route of the workpiece according to the required processing shape and basic machine tool parameters, and obtain the initial position information by detecting the physical change state of the water jet near the workpiece through the detection unit;

[0046] S2, by controlling the relative movement data between the processing unit and the workpiece through the control unit, the contact point position information is obtained based on the difference information of the relative movement data;

[0047] S3, measure the target points with a preset density to obtain the target point position information, and perform data fitting on the target point position information to obtain the actual processed shape;

[0048] S4, determine whether the error data between the actual processed shape and the required processed shape meets the preset accuracy requirements, and perform accuracy compensation based on the judgment result that the preset accuracy requirements are not met to obtain the optimal compensation amount.

[0049] Furthermore, after obtaining the target point location information, the method also includes: automatically obtaining a set of location information points containing the target point location information using a numerical control system.

[0050] Further, it is determined whether the error data between the actual processed shape and the required processed shape meets the preset accuracy requirements, so as to obtain the optimal compensation amount by performing accuracy compensation based on the judgment result that the preset accuracy requirements are not met, including:

[0051] The actual machining shape based on the fitted curve is obtained by fitting the set of position information points recorded in the CNC system.

[0052] The actual processed shape and the required processed shape are image processed to obtain overall image error data;

[0053] The optimal compensation amount is obtained by processing the overall error data of the image according to the preset accuracy requirements and the least squares method.

[0054] Further, the step of determining whether the error data between the actual processed shape and the required processed shape meets the preset accuracy requirements, and then performing accuracy compensation based on the determination result that the preset accuracy requirements are not met to obtain the optimal compensation amount, may include:

[0055] A key point set is obtained by determining key points based on the location information point set and the required processing shape;

[0056] The error of the discrete corresponding key points in the set of key points is taken as the discrete error quantity;

[0057] The least squares method is used to process the discrete error to obtain the optimal compensation amount.

[0058] Furthermore, after obtaining the optimal compensation amount, the method further includes using the error data as a new required machining shape for the workpiece to determine a new planned inspection route and basic machine tool parameters.

[0059] In some embodiments of the present invention, such as Figure 4 As shown, the process of implementing the method of the present invention includes:

[0060] The first step is manual clamping.

[0061] The second step involves automatically planning the trajectory and setting the parameters according to the required machining shape and the basic parameters of the machine tool through the CNC program, and then proceeding with the machining after the preparation work is completed.

[0062] The third step is to perform automatic online measurement. Using the position information obtained from the automatic online measurement, the actual workpiece shape is fitted, and the error is compared with the required machining shape to obtain error data. If the error meets the machining accuracy requirements, subsequent processing steps such as cutting are directly performed, the workpiece is removed, and machining is complete. If the error does not meet the machining accuracy requirements, accuracy compensation is performed. This error data is used as a new machining requirement, and combined with the relative position of the electrode wire and the workpiece, a new round of trajectory planning and machining parameter selection is performed.

[0063] It is important to note that during the finishing process, in order to ensure machining accuracy, it is necessary to minimize the number of machining operations. This reduces additional errors caused by factors such as the equipment's repetitive positioning accuracy, thereby increasing machining speed while ensuring machining accuracy.

[0064] The water-guided laser automatic online measurement and compensation method according to embodiments of the present invention can shorten the processing flow, save manpower and material resources, and improve processing efficiency and accuracy through automatic online measurement and accuracy compensation.

[0065] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0066] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

Claims

1. A water-guided laser automatic online measurement and compensation system, characterized in that, include: The processing unit is used to generate a water jet that conducts laser light to process the workpiece; A control unit is used to control the relative movement of a processing unit or a workpiece. The detection unit is used to move the water jet along a planned detection route determined according to the required processing shape under the control of the control unit, and to detect the physical change signal caused by the change of water jet state when the water jet comes into contact with the workpiece during the movement, so as to obtain the position information of the contact point; as well as The CNC system is used to fit the actual machining shape of the workpiece based on position information and relative movement data, and compare the actual machining shape with the preset required machining shape. If the error does not meet the preset accuracy requirements, accuracy compensation is performed to obtain the optimal compensation amount.

2. The system according to claim 1, characterized in that, The control unit is also used to collect information generated by the detection unit.

3. The system according to claim 1, characterized in that, The detection unit detects the physical changes in the water jet, including acoustic and optical changes.

4. The system according to claim 1, characterized in that, The detection unit is also used to detect the electrical signal between the processing unit and the workpiece.

5. A precision compensation method applied to the water-guided laser automatic online measurement and compensation system according to any one of claims 1-4, characterized in that, The method includes the following steps: The planned inspection route for the machined parts is determined based on the required machining shape and the basic parameters of the machine tool; The control unit moves relative to the workpiece, causing the water jet to move along the planned detection route. During the movement, the detection unit detects the physical change signal caused by the change in the state of the water jet when it comes into contact with the workpiece, so as to obtain the position information of the contact point. The target point location information is obtained by measuring the target points at a preset density based on the contact point location information; The actual processed shape is obtained by fitting the target point location information with data. The error data is obtained by comparing the actual processed shape with the required processed shape. Determine whether the error data meets the preset accuracy requirements. If not, perform accuracy compensation to obtain the optimal compensation amount.

6. The method according to claim 5, characterized in that, After obtaining the target point location information, the method further includes: automatically obtaining a set of location information points containing the target point location information using a numerical control system.

7. The method according to claim 6, characterized in that, The step of determining whether the error data between the actual processed shape and the required processed shape meets the preset accuracy requirements, and then performing accuracy compensation based on the determination result that the preset accuracy requirements are not met to obtain the optimal compensation amount, includes: The actual machining shape based on the fitted curve is obtained by fitting the set of position information points recorded in the CNC system. The actual processed shape and the required processed shape are image processed to obtain overall image error data; The optimal compensation amount is obtained by processing the overall error data of the image according to the preset accuracy requirements and the least squares method.

8. The method according to claim 7, characterized in that, The step of determining whether the error data between the actual processed shape and the required processed shape meets the preset accuracy requirements, and then performing accuracy compensation based on the determination result that the preset accuracy requirements are not met to obtain the optimal compensation amount, may include: A key point set is obtained by determining key points based on the location information point set and the required processing shape; The error of the discrete corresponding key points in the set of key points is taken as the discrete error quantity; The least squares method is used to process the discrete error to obtain the optimal compensation amount.

9. The method according to claim 5, characterized in that, After obtaining the optimal compensation amount, the method further includes using the error data as a new required machining shape for the workpiece to determine a new planned inspection route and basic machine tool parameters.

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