CN114515795A - Laser auxiliary correction method and device based on visual error compensation - Google Patents

Abstract

The invention discloses a laser auxiliary correction device based on visual error compensation. The laser module is used for emitting laser beams and radiating laser tracks on the surface of a material to be processed; the visual detection module is used for detecting laser track position data, visual measurement mark point position data and material boundary position data, and is arranged right above the material and coaxially mounted with the laser module; the signal transmission module is used for transmitting the detected position data to the central processing module. The invention also discloses the laser auxiliary correction method. The device and the method can ensure continuous production and position correction without stopping the machine, and improve the practical significance of laser assistance in the processing and application of metal materials.

Description

A laser-assisted correction method and device based on visual error compensation

technical field

The invention belongs to the field of metal forming, and in particular relates to a laser-assisted correction method and device based on visual error compensation.

Background technique

Based on the rapid changes in the market, the demand for high-performance and high-value-added components has grown exponentially; lightweight has become the top priority of major industrial fields. As a result, a large number of new metal processing techniques have been proposed and studied. As one of the core technologies, thermal assisted forming adopts a variety of modes for processing, and the laser assisted forming technology using laser as the energy source has the advantages of fast response, accurate forming, and low degree of equipment modification, which ensures the manufacturing process. The parts can have good mechanical properties and surface finish, and at the same time reduce material consumption and hardware upgrade costs during the manufacturing process, without affecting the productivity at all. These advantages are difficult to achieve by many traditional processes and additional processes.

However, in the laser-assisted forming process, there is a problem that is difficult to overcome, that is, the cooperative work problem of laser, metal materials and machining systems in a complex processing environment. Taking the metal stamping process as an example, the huge impact force displaces the material, which makes it difficult for the laser profile of the preheated radiation to be processed perfectly, resulting in deviations, surface defects of parts, reduced quality, and even complete laser-assisted effects. disappear, this problem can greatly affect the practicality of the laser-assisted forming process.

At present, to solve the above problems, only a very passive part-based analysis and compensation process can be used: after the parts are produced, the completed parts are used as the standard to judge the deviation between the laser heating traces on the parts and the actual processing traces, and then Manually adjusting the laser/material position is an extremely inefficient and ineffective process for the following reasons:

1. The metal forming process is a continuous process, the actual lag of the parts obtained is too large, and an average of 4-8 stations or more has been consumed, resulting in a huge waste of working hours;

2. The continuous process results in that the quality of all subsequent parts cannot be guaranteed before the reference parts are obtained, which greatly wastes raw materials;

3. The errors in the material and processing process are accumulated and superimposed, and the existing reference parts can no longer represent the current material state, resulting in little correction;

4. Repeated shutdown and correction, which consumes a lot of production time, increases the manufacturing cost, which is of no practical significance.

In summary, how to solve or monitor the position status of materials in real time is the basis of the laser-assisted forming process. If this core problem is not solved, the economic benefits and good performance effects of laser-assisted forming will be greatly reduced.

SUMMARY OF THE INVENTION

Aiming at the problem of material deviation caused by vibration, equipment interference and environmental influence in the current laser-assisted forming process in the field of metal processing, the present invention provides a laser-assisted correction method and device based on visual error compensation.

Laser-assisted process, for laser heating, marking, etching, polishing, etc., a certain laser-assisted forming process that needs to be carried out on a specific position of the material; it can also be a certain pre-treatment process, for subsequent stamping, drawing, milling and other metal processing technology. Metal forming methods, in addition to metal stamping methods, also include all metal processing methods such as metal drawing, complete, machining, polishing, and milling that use laser assistance as the pre-process. The forming equipment can be various types of punching machines, machine tools, CNC and other metal forming equipment. The core work of the present invention lies in the process of coordinating laser and metal processing, and is applicable to various processing technologies.

The present invention provides a laser auxiliary correction device based on visual error compensation, which includes a laser module, a visual detection module, a signal transmission module and a central processing module, wherein,

The laser module is used to emit a laser beam and radiate a laser trajectory on the surface of the material to be processed;

The visual detection module is used to detect laser trajectory position data, visual measurement marker position data and material boundary position data;

The signal transmission module is used to transmit the detected position data to the central processing module;

The central processing module is used to calculate the material offset angle and the XY axis offset under the reference frame according to the laser track position data, the visual measurement marker position data and the material boundary position data, and the reference frame is based on the visual measurement The parallel sides of the marked points are established by reference. Compensation calculation is performed according to the offset angle and the offset amount to obtain the rotation angle and distance that the laser trajectory should move in coordination with the material position. Adjust the laser module to make the laser radiation To the compensated position, a laser trajectory corrected for the material is generated, or an alarm is issued when the offset angle and/or the offset amount exceeds a threshold.

In the embodiment of the present invention, one visual measurement mark point is attached to the upper and lower directions of the work station in the visual inspection area, and the visual measurement mark point has a different color and reflectivity from the material.

The adjusting the laser module includes adjusting the angle of the galvanometer and the reflection structure.

The visual inspection module includes an optical camera and can emit inspection light. The visual inspection module can be arranged just above the material. The visual inspection module can be installed coaxially with the laser module.

The laser module also includes a laser protection device.

When the offset angle and/or the offset amount exceeds a threshold, the central processing module may also perform a predetermined action, and the predetermined action includes shutting down.

The specific calculation process for calculating the material offset angle and XY-axis offset under the reference frame according to the laser track position data, the visual measurement mark position data and the material boundary position data is as follows: using the parallel sides of the visual measurement mark as the Reference, get the offset angle of the material, use the position of the laser track to calculate the offset about the Y-axis, and calculate the X-axis offset again through the Y-axis offset and the corresponding angle.

The present invention also provides a laser-assisted correction method for visual error compensation, comprising the following steps:

Step 1, at the workstation of the visual inspection area, paste a visual measurement mark point up and down;

Step 2, the laser module emits a laser beam, and radiates a laser track on the surface of the material to be processed;

Step 3, the visual detection module detects laser trajectory position data, material boundary position data and visual measurement marker position data;

Step 4, take the parallel edge of the visual measurement mark as the reference system, calculate the XY axis offset and the angle offset data of the material according to the laser trajectory position data, the material boundary position data and the visual measurement mark position data, and carry out The corresponding compensation calculation is used to obtain the rotation angle and distance data that the laser trajectory should move in coordination with the material position;

Step 5: Adjust the laser module according to the rotation angle and distance data calculated by the compensation, so that the laser is radiated to the position after compensation, and the laser trajectory corrected for the material is generated, or the XY axis is offset and/or the angle is offset. Alarm when the shift data exceeds the threshold.

Repeat the above steps, and complete the fine-tuning of the laser radiation position before each metal processing to achieve the most perfect processing effect.

Further, the method can be applied to metal stamping processing, and the visual measurement mark point has a different color and reflectivity from the material. Adjusting the laser module in step 5 includes adjusting the angle of the galvanometer and the reflective structure.

Further, the visual inspection module is arranged just above the material, and is installed coaxially with the laser module, and the laser module includes a laser protection device.

Further, when the offset angle and/or the offset amount exceeds the threshold value, an alarm is issued, and the machine is stopped at the same time.

Further, the specific calculation process for calculating the offset angle of the material and the offset of the XY axis in step 4 is as follows: using the parallel edge of the visual measurement mark point as a reference, the offset angle of the material is obtained, and the position of the laser track is used to calculate The offset about the Y axis is calculated, and the X axis offset is calculated again through the Y axis offset and the corresponding angle.

The laser-assisted correction method and device based on visual error compensation proposed by the present invention can be applied to metal stamping processing. The core parts of the device are a visual detection module, a signal transmission module, a central processing module, etc.; the device is installed in the laser-assisted area for real-time Monitor the displacement of the material, make corresponding analysis and compensation calculations, transmit the signal to the laser emission system, and make the laser adjust the corresponding angle and position to match the existing metal material position. Finally, the metal forming equipment will process the raw material whose laser radiation position is adjusted to form the corresponding parts more accurately.

Description of drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the disclosure and together with the description serve to explain the principles of the disclosure.

1 is a schematic structural diagram of a laser-assisted correction method and device based on visual error compensation of the present invention;

Fig. 2 is a schematic diagram of laser radiation position deviation based on material deviation;

FIG. 3 is a schematic diagram of a visual capture and correction process.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

Laser-assisted process, for laser heating, marking, etching, polishing, etc., a certain laser-assisted forming process that needs to be carried out on a specific position of the material; it can also be a certain pre-treatment process, for subsequent stamping, drawing, milling and other metal processing processes; the forming equipment can be various types of punches, machine tools, CNC and other metal forming equipment.

The invention provides a laser-assisted correction method and device based on visual error compensation. The device and method are aimed at the current laser-assisted forming process in the field of metal processing to solve the problem of material deviation caused by vibration, equipment interference and environmental influence. move the problem. The device and method can be used in many fields, because different machining and metal material forming methods require a positioning correction method to improve productivity and quality, and the device and method can be used universally. In order to clearly show the whole process, the present invention uses the metal stamping process as an example to illustrate the process.

Figure 1 shows the structure of a punch press with a visual inspection module installed, as well as the corresponding mold and laser equipment. Since only the visual inspection module is required to be installed in the working area of the entire system, others such as signal transmission modules and central processing modules can be installed through cables. The signal is transmitted and thus installed in a space far away from the mechanical equipment, so it is not represented in FIG. 1 . The core of the visual inspection module is an optical camera or other similar functional system, which can quickly capture the structural target of the preset value; the visual inspection module is small in size and is installed just above the metal material, and can be installed coaxially with the laser head to ensure the space. The system will be equipped with a laser protection device and a built-in light source to make the visual capture process more convenient; the visual measurement marking points are reflective materials suitable for optical detection, which can reflect light stably and provide input data for the visual system.

As shown in FIG. 1 , upper and lower dies, an upper die 7 and a lower die 8 are installed in the punch press 1 to perform metal forming work. The punch press 1 is provided with a laser-assisted processing station in the feeding direction, in which a laser module 2 is provided. At the same time, the core working part of the present invention, the visual detection module 3, is installed near the laser module 2. In order to better obtain the visual content, the two can be installed coaxially, so that the visual detection module 3 is as close to the laser as possible. Auxiliary radiation area. In the following work, the laser module 2 will emit the laser beam 4 according to the auxiliary instructions, radiate on the material 5, and complete the designed laser trajectory. After that, the material will move under the drive of the feeder 6 and enter the punch processing area; 7 Moves down, the stamping passes through the area of laser radiation. At this time, whether the stamping position and the laser position are carried out according to the preset relationship is the key point of the entire forming process.

Figure 2 is a schematic diagram of laser radiation position deviation based on material offset; the figure shows the top view of the material, and three steps are used in the figure to illustrate the process relationship of the material offset and the processing error.

As shown in Figure 2.1 in Figure 2, the laser processing area is represented by a square dashed box 2.1.3, and the metal forming area is represented by a square dashed box 2.1.4. The laser scans the required geometric contour 2.1.2 on the surface of the material according to the system preset (circular example is used in the present invention). Then, the material is driven by the feeder to move, and in a completely ideal case, the material will be conveyed straight and without offset to the corresponding position of the punching punch shown in 2.1.5.

Ideally, the position of the material is shown in Figure 2.2 in Figure 2. The two circle trajectories have corresponding positions on the material to be processed, which is a standard concentric geometry.

However, in the actual processing situation, due to a large number of engineering equipment problems, such as old punching machines, inaccurate feeders, large environmental vibrations, friction during transportation, etc., the material will be driven by the feeder. Azimuth fluctuation, if this azimuth fluctuation is in the traditional processing technology, it will not show a significant impact; but in the process of multi-process coordination such as laser assistance, it will cause deviations such as the inability of the front and rear processes to be unified, as shown in Figure 2 As shown in Figure 2.3: It can be seen that when the metal moves at a slight angle (for the convenience of expression, it is assumed that the material is rotated by 1°), the original laser trajectory 2.1.2 has produced a large amount of deviation from the stamping trajectory circle 2.1.5, and the laser trajectory will be completely It is not possible to provide functional assistance for the original product manufacturing. On the contrary, useless laser traces remain on the product, which will reduce the value of the product.

Figure 3 shows how the system monitors and corrects in real time: Figure 3.1 shows the same situation as Figure 2.3, assuming that this is the first time the laser track 3.1.6 enters the stamping area, then the laser track 3.1. 6 has deviated from punching position 3.1.7. At this time, the visual detection module will start to work in the visual detection area 3.1.2 (indicated by a circular wireframe), and the visual detection module will emit a detection red light (or other suitable monochromatic light source for detection), and the light will be reflected by the laser trace after being reflected. Accept, since the punch, die and visual inspection module are all rigid installations, the position of the upper die will not change, so the visual inspection module can simulate the punching position at this time.

In the visual inspection area, there are two visual measurement markers 3.1.3 with strong reflection effect. Since the surface of the metal material is smooth, it is easy to cause light reflection, and it is difficult to directly identify the material position accurately. Therefore, this system adopts a new design concept, adopts visual identification mark points, and uses lines formed by material edges and external spaces for visual identification and analysis, which can greatly improve the identification efficiency and accuracy.

Figure 3.2 shows the recognition process. When the visual inspection module recognizes the two boundaries of the offset material, it will re-identify the two visual measurement markers in the system 3.1.3. When the position data of the four elements are all read, the data will be transmitted to the central processing module for analysis. During this analysis, using the parallel edge of the visual measurement mark point as a reference, the offset angle 3.2.3 of the material can be obtained, and using the position of the laser track, the offset L1\L2 about the Y axis can be calculated as data 3.2.1 and 3.2.2, and through the Y-axis offset and the corresponding angle, the X-axis offset can be calculated again. As a result, the material position data can be obtained completely and accurately for the material offset in this station.

After that, as shown in Figure 3.3, the data is fed back to the laser system, and the laser system adjusts the angle of the galvanometer and the reflective structure, and can instantly perform a new laser scan at the new offset correction position 3.3.1, resulting in a correction for the material. Laser trace simulation position, this new position 3.3.2 will not remain at the original material position, but it can be concentrically matched to the stamping trace 3.1.7, thereby greatly reducing production errors. In addition, the system can also set the alarm function of excessive error. If the measurement finds that the error is too large, the system will directly give an alarm and make actions such as shutdown according to the preset command. This is because the excessive error may mean a mistake in the mold design or The old wear of the feeder has exceeded the normal acceptable range.

In an exemplary embodiment, the laser-assisted correction method for visual error compensation includes the following steps:

Step 1, at the workstation of the visual inspection area, paste a visual measurement mark point up and down;

Step 2, emit a laser beam, and radiate a laser track on the surface of the material to be processed;

Step 3, the visual detection module detects laser trajectory position data, material boundary position data and visual measurement marker position data;

Step 4, with the parallel edge of the visual measurement mark as the reference system, calculate the XY axis offset and the angle offset data of the material according to the laser trajectory position data, the material boundary position data and the visual measurement mark position data, and carry out. The corresponding compensation calculation is used to obtain the rotation angle and distance data that the laser trajectory should move in coordination with the material position;

Step 5: Adjust the laser module according to the rotation angle and distance data calculated by the compensation, so that the laser is radiated to the position after compensation, and the laser trajectory corrected for the material is generated, or the XY axis is offset and/or the angle is offset. Alarm when the shift data exceeds the threshold.

Repeat the above steps, and complete the fine-tuning of the laser radiation position before each metal processing to achieve the most perfect processing effect.

Further, the method can be applied to metal stamping processing, and the visual measurement mark point has a different color and reflectivity from the material. Adjusting the laser module in step 5 includes adjusting the angle of the galvanometer and the reflective structure.

Further, the visual inspection module is arranged just above the material, and is installed coaxially with the laser module, and the laser module includes a laser protection device.

Further, when the offset angle and/or the offset amount exceeds the threshold value, an alarm is issued, and the machine is stopped at the same time.

Further, the specific calculation process for calculating the offset angle of the material and the offset of the XY axis in step 4 is as follows: using the parallel edge of the visual measurement mark point as a reference, the offset angle of the material is obtained, and the position of the laser track is used to calculate The offset about the Y axis is calculated, and the X axis offset is calculated again through the Y axis offset and the corresponding angle.

Therefore, without stopping the machine, the laser-assisted correction method and device based on visual error compensation can ensure continuous production and position correction in the whole process. The process directly eliminates the superimposed motion of the material, and at the same time, there is no need to wait for manual correction after the stamping is completed. The method and device improve the practical significance of laser assistance in the processing and application of metal materials.

The above-mentioned embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or transformations made by those skilled in the art on the basis of the present invention are all within the protection scope of the present invention. The protection scope of the present invention is subject to the claims.

Claims (10)

1. A laser-assisted correction device based on visual error compensation, characterized in that: the device comprises a laser module, a visual detection module, a signal transmission module and a central processing module, wherein, The laser module is used to emit a laser beam and radiate a laser trajectory on the surface of the material to be processed; a visual detection module for detecting laser track position data, visual measurement mark position data and material boundary position data; the visual detection module is arranged just above the material and is installed coaxially with the laser module; The signal transmission module is used to transmit the detected position data to the central processing module; The central processing module is used to calculate the material offset angle and the XY axis offset under the reference frame according to the laser track position data, the visual measurement marker position data and the material boundary position data, and the reference frame is based on the visual measurement The parallel sides of the marked points are established by reference. Compensation calculation is performed according to the offset angle and the offset amount to obtain the rotation angle and distance that the laser trajectory should move in coordination with the material position. Adjust the laser module to make the laser radiation To the compensated position, a laser trajectory corrected for the material is generated, or an alarm is issued when the offset angle and/or the offset amount exceeds a threshold. 2. A laser-assisted correction device based on visual error compensation according to claim 1, characterized in that: a visual measurement mark point is respectively attached to the upper and lower directions of the workstation in the visual inspection area, and the visual measurement mark point has Unlike materials with different colors and reflectances, the adjusting the laser module includes adjusting the angle of the galvanometer and the reflective structure. 3 . The laser-assisted correction device based on visual error compensation according to claim 1 , wherein the laser module comprises a laser protection device. 4 . 4. A laser-assisted correction device based on visual error compensation according to claim 1, wherein the central processing module issues an alarm when the offset angle and/or the offset amount exceeds a threshold, stop at the same time. 5 . A laser-assisted correction device based on visual error compensation according to claim 1 , wherein the reference frame is calculated according to the laser trajectory position data, the visual measurement mark position data and the material boundary position data. 6 . The specific calculation process of the material offset angle and XY axis offset below is: use the parallel edge of the visual measurement mark as a reference to obtain the offset angle of the material, and use the position of the laser track to calculate the offset about the Y axis. Offset, and calculate the X-axis offset again through the Y-axis offset and the corresponding angle. 6. A laser-assisted correction method based on visual error compensation, characterized in that the method comprises the steps: Step 1, at the workstation of the visual inspection area, paste a visual measurement mark point up and down; Step 2, the laser module emits a laser beam, and radiates a laser track on the surface of the material to be processed; Step 3, the visual detection module detects the laser track position data, the material boundary position data and the visual measurement mark position data, wherein the visual detection module is arranged just above the material and is installed coaxially with the laser module; Step 4, with the parallel edge of the visual measurement mark as the reference system, calculate the XY axis offset and the angle offset data of the material according to the laser trajectory position data, the material boundary position data and the visual measurement mark position data, and carry out. The corresponding compensation calculation is used to obtain the rotation angle and distance data that the laser trajectory should move in coordination with the material position; Step 5: Adjust the laser module according to the rotation angle and distance data calculated by the compensation, so that the laser is radiated to the position after compensation, and the laser trajectory corrected for the material is generated, or the XY axis is offset and/or the angle is offset. Alarm when the shift data exceeds the threshold. 7. A laser-assisted correction method based on visual error compensation according to claim 6, characterized in that: the method can be applied to metal stamping processing, and the visual measurement mark point has a different color and reflection from the material rate, and adjusting the laser module in step 5 includes adjusting the angle of the galvanometer and the reflective structure. 8 . The laser-assisted correction method based on visual error compensation according to claim 6 , wherein the laser module comprises a laser protection device. 9 . 9 . The laser-assisted correction method based on visual error compensation according to claim 6 , characterized in that: when the offset angle and/or the offset amount exceeds a threshold, an alarm is issued, and the machine is stopped at the same time. 10 . 10. A laser-assisted correction method based on visual error compensation according to claim 6, wherein the specific calculation process for calculating the material offset angle and the XY axis offset in the step 4 is: using visual Measure the parallel side of the marked point as a reference to obtain the offset angle of the material, use the position of the laser track to calculate the offset about the Y-axis, and calculate the X-axis offset again through the Y-axis offset and the corresponding angle .

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