A galvanometer calibration device, system, laser marking device and galvanometer calibration method

Abstract

The present application discloses a galvanometer calibration device, system, laser marking device and galvanometer calibration method, the galvanometer device includes a calibrator, on which a plurality of acquisition units arranged in a matrix are installed; each acquisition unit includes a light-guiding medium and a photoelectric sensor arranged on one side of the light-guiding medium; a diffuse reflection area and a non-diffuse reflection area are arranged inside the light-guiding medium, the diffuse reflection area includes at least one diffuse reflection line, and the photoelectric sensor is arranged on the diffuse reflection line; when the incident laser passes through the diffuse reflection area, scattering occurs, and the scattered laser is conducted inside the light-guiding medium, and part of the scattered laser is received by the photoelectric sensor and converted into an electrical signal. The present invention utilizes the diffuse reflection characteristics of light and photoelectric sensors to collect signals, and effectively improves the calibration accuracy, efficiency and stability through the design of multiple acquisition units arranged in a matrix; the automated processing method reduces manual intervention, and reduces the cost and operation difficulty of galvanometer calibration.

Description

Technical Field

[0001] The present invention relates to the technical field of laser galvanometer calibration, and in particular to a galvanometer calibration device, a system, a laser marking device and a galvanometer calibration method. Background Art

[0002] Laser processing technology is a processing technology that uses the characteristics of the interaction between laser beams and materials to cut, weld, surface treat, punch holes and micro-process materials. With the continuous development of laser technology, laser processing technology has been widely used in various fields. The galvanometer acts as an actuator to make the laser focus move on the processing object according to the required trajectory. The processing accuracy of the galvanometer determines the accuracy of the entire laser processing system. Due to the influence of factors such as temperature, mechanical vibration, and the reliability of the system itself, the galvanometer system often suffers from distortion and needs to be calibrated regularly.

[0003] The traditional calibration is to mark matrix cross-crossing calibration points on the calibration test board, manually measure and calculate the deviation between theory and practice, and then generate a calibration file through compensation calculation software. When the number of measured coordinate points is large or multiple galvanometers are spliced, this method is not only very time-consuming, but also prone to cumulative errors, resulting in insufficient calibration accuracy.

[0004] Therefore, it is urgent to propose a galvanometer calibration device, system, laser marking device and galvanometer calibration method, which can improve the accuracy, efficiency and stability of galvanometer calibration, reduce the failure rate and operating cost of the calibration system, and improve production efficiency. Summary of the invention

[0005] The invention provides a galvanometer calibration device, a system, a laser marking device and a galvanometer calibration method, which are used to solve the technical problems of low calibration accuracy, low efficiency and poor stability of the existing galvanometer calibration system.

[0006] In order to solve the above problems, in a first aspect, the present invention provides a galvanometer calibration device, including a calibrator, on which a plurality of acquisition units arranged in a matrix are installed; each acquisition unit includes a light-guiding medium and a photoelectric sensor arranged on one side of the light-guiding medium;

[0007] The light-guiding medium is provided with a diffuse reflection area and a non-diffuse reflection area inside, the diffuse reflection area includes at least one diffuse reflection line, and the photoelectric sensor is arranged on the diffuse reflection line;

[0008] When the incident laser passes through the diffuse reflection area, scattering will occur, and the scattered laser light is transmitted inside the light-guiding medium. Part of the scattered laser light is received by the photoelectric sensor and converted into an electrical signal.

[0009] Furthermore, the light-guiding medium is any one of a cylinder, a cuboid, a cube, a cone, a sphere, and a triangular prism.

[0010] Furthermore, the diffuse reflection line of the diffuse reflection area is a line, a pattern or any geometric figure.

[0011] In a second aspect, the present invention provides a galvanometer calibration system, comprising a controller, wherein the controller is connected to a laser, a galvanometer, a calibration device and a processor; the processor is connected to the calibration device; wherein the calibration device adopts the galvanometer calibration device described in any one of the above technical solutions.

[0012] In a third aspect, the present invention provides a laser marking device, comprising a galvanometer calibration system as described in any one of the above technical solutions.

[0013] In a fourth aspect, a galvanometer calibration method is implemented by using the galvanometer calibration system in the above technical solution, comprising:

[0014] The processor sends a calibration start instruction to the controller;

[0015] The controller controls the laser to emit laser light through control instructions, and controls the galvanometer to deflect, so that the focus of the laser scans the plurality of acquisition units on the calibration instrument in sequence according to a predetermined trajectory;

[0016] When the laser scans the diffuse reflection area in the light-guiding medium in each acquisition unit, the laser undergoes diffuse reflection and is scattered inside the light-guiding medium. The scattered light is captured by a photoelectric sensor placed on one side of the light-guiding medium and converted into an electrical signal and sent to the calibration instrument.

[0017] The calibrator transmits the electrical signal to the processor;

[0018] The processor performs filtering and fitting calculation on the electrical signal to obtain the actual marking coordinates of the acquisition unit, compares the actual marking coordinates with the a priori coordinates sent by the controller, generates a calibration file and sends it back to the controller;

[0019] The controller performs a calibration operation on the galvanometer according to the correction.

[0020] Furthermore, the controller controls the laser to emit laser light through control instructions, and controls the galvanometer to deflect, so that the focus of the laser scans the plurality of acquisition units on the calibration instrument in sequence according to a predetermined trajectory, including:

[0021] The controller sends a gating instruction to the calibrator;

[0022] The calibrator gates the sensors of the acquisition units to be detected according to the gate instruction;

[0023] The controller controls the deflection of the galvanometer according to the prior data, so that the laser scans sequentially in the diffuse reflection area of ​​the light-guiding medium in each acquisition unit according to a preset track.

[0024] Furthermore, the method for obtaining the priori coordinates is:

[0025] Establish a reference coordinate system based on the calibration instrument;

[0026] Using a two-dimensional measuring device, measure multiple reference positions of each acquisition unit respectively, and record the center point position of the acquisition unit;

[0027] According to the reference position and the center point position, the prior coordinates of each reference line and the center point in each acquisition unit on the calibration instrument in the reference coordinate system are determined.

[0028] Furthermore, the processor performs filtering and fitting calculation on the electrical signal to obtain the actual marking coordinates of the acquisition unit, including:

[0029] The controller controls the galvanometer to deflect, so that the laser scans the collection unit along a preset direction, and the scanning trajectory of the laser intersects with the diffuse reflection area in the collection unit to obtain a plurality of intersection points;

[0030] The laser is received by the photoelectric sensor after being scattered at each intersection point, and is converted into an electrical signal and transmitted back to the processor;

[0031] The processor calculates the actual marking coordinates of the acquisition unit according to the return time of the electrical signals at the multiple intersection points and the priori size data of the acquisition unit.

[0032] Furthermore, the processor calculates the actual marking coordinates of the acquisition unit according to the return time of the electrical signals at the plurality of intersection points in combination with the priori size data of the acquisition unit, including:

[0033] Calculating the scattered light guiding speed of the scattered light in the collection unit according to the first receiving time difference of the first intersection point combination among the plurality of intersection points and the priori size data of the collection unit;

[0034] The actual coordinate value of the reference line in the acquisition unit is calculated according to a plurality of second receiving time difference values ​​of a plurality of pairs of second intersection point combinations among the plurality of intersection points and the scattered light guiding speed.

[0035] Furthermore, the actual marking coordinates are compared with the a priori coordinates sent by the controller to generate a calibration file, including:

[0036] Comparing the actual coordinate value of the reference line with the prior coordinate to obtain the trajectory coordinate error;

[0037] Position compensation and correction are performed according to the trajectory coordinates to generate a correction file.

[0038] Compared with the prior art, the beneficial effects of the present invention include:

[0039] (1) The diffuse reflection area in the light-guiding medium can effectively scatter the incident laser and generate multiple scattering paths. Through these scattered lasers, the photoelectric sensor can receive signals from different angles and positions. This multi-point acquisition and omnidirectional perception can greatly improve the calibration accuracy, making the motion trajectory and error compensation of the galvanometer more accurate.

[0040] (2) Multiple acquisition units are arranged in a matrix, and each acquisition unit can collect data independently. The matrix arrangement design of multiple acquisition units has redundancy, which can effectively reduce the impact of a single unit failure. If a unit fails, other units can still provide accurate data, ensuring that the calibration process is not affected.

[0041] (3) The working principle and structural design of the equipment enable the calibration process to be highly automated, reducing the need for human intervention. Through automated acquisition and signal processing, the errors caused by human operation can be reduced, ensuring the efficiency and accuracy of the calibration process.

[0042] (4) Since the calibration equipment design introduces redundancy mechanisms and highly reliable sensor systems, it can reduce maintenance costs caused by single-point failures, and the large-scale matrix also reduces the overall production cost. The efficient and reliable calibration system greatly reduces the overall operating cost of the equipment.

[0043] In summary, the present invention effectively improves the calibration accuracy, efficiency and stability through the multiple acquisition units arranged in a matrix and the diffuse reflection design in the light-guiding medium. The system reliability is enhanced through the redundant design, the automation and intelligent processing reduce the manual intervention, and it has flexible adaptability and scalability, which is suitable for laser processing systems of different environments and scales. In addition, the design of the equipment can also reduce the system failure rate and operating costs, and improve production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A schematic diagram of the structure of the galvanometer calibration device provided by the present invention;

[0045] Figure 2 A structural diagram of a collection unit provided by the present invention;

[0046] Figure 3A top view of the structure of the collection unit provided by the present invention;

[0047] Figure 4 A schematic diagram of the structure of the galvanometer calibration system provided by the present invention;

[0048] Figure 5 A schematic diagram of the change of the voltage signal collected by the sensor provided by the present invention;

[0049] Figure 6 A schematic diagram of the measurement process of the a priori coordinates provided by the present invention;

[0050] Figure 7 A schematic diagram of the galvanometer calibration process provided by the present invention;

[0051] In the figure, 1-processor, 2-controller, 3-signal transmission line, 4-laser, 5-galvanometer, 6-calibrator, 7-acquisition unit, 8-data acquisition line, 12-light-transmitting glass, 13-incident laser, 16-photoelectric sensor, 25-diffuse reflection area, 39-non-diffuse reflection area. DETAILED DESCRIPTION

[0052] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0053] Example 1

[0054] like Figure 1 As shown, this embodiment provides a galvanometer calibration device, including a calibration instrument 6, on which a plurality of acquisition units 7 arranged in a matrix are installed; each acquisition unit 7 includes a light-guiding medium and a photoelectric sensor 16 arranged on one side of the light-guiding medium, such as Figure 2 As shown;

[0055] The light-guiding medium is a light-transmitting glass 12, and a diffuse reflection area 25 and a non-diffuse reflection area are arranged inside the light-transmitting glass 12. The diffuse reflection area 25 includes at least one diffuse reflection line, and the photoelectric sensor 16 is arranged on the diffuse reflection line;

[0056] When the incident laser light 13 passes through the diffuse reflection area 25 , scattering will occur. The scattered laser light is transmitted inside the light-guiding medium, and part of the scattered laser light is received by the photoelectric sensor 16 and converted into an electrical signal.

[0057] The diffuse reflection area 25 refers to an area that can be made on the light-guiding medium in any way and can cause light to be diffusely reflected and scattered. The photoelectric sensor is arranged on the diffuse reflection line, which means that the photoelectric sensor is arranged on the line of diffuse reflection light transmitted by the light-guiding medium, and the light here can be visible light or laser of any wavelength.

[0058] The galvanometer calibration device provided in this embodiment sets a diffuse reflection area inside the light-transmitting glass. When the laser passes through this area, it will be scattered and transmitted in the light-guiding medium, and the scattered light signal is received by the photoelectric sensor. This device ensures that the scattered light when the laser passes through the diffuse reflection area can be effectively received and converted into an electrical signal by the photoelectric sensor, so that the actual position of the laser can be accurately measured. When this device is used in a galvanometer calibration system, by measuring the electrical signal received by the photoelectric sensor when the laser passes through the diffuse reflection area, these signals are compared with the theoretical position, and the error between the actual position of the laser and the expected position can be calculated. The system can automatically compensate and correct according to the error, thereby improving the measurement accuracy, efficiency and stability during the calibration process.

[0059] In order to more clearly show the structure of the light-guiding medium in the collection unit 7, as shown in FIG. Figure 3 As shown, Figure 3 The schematic diagram of the top view of the light-transmitting glass 12 is shown. As a specific embodiment, a diffuse reflection area 25 and a non-diffuse reflection area 39 are provided inside the light-transmitting glass 12 .

[0060] As a specific embodiment, there may be one or more diffuse reflection areas. Figure 2 The dashed arrow in the middle represents the light path when diffuse reflection occurs, indicating that when diffuse reflection occurs, the laser light will be transmitted inside the glass body and thus be collected by the sensor. On the contrary, when the laser does not pass through the diffuse reflection area on the glass but passes through the non-diffuse reflection area, the laser light irradiated on the glass will directly pass through the glass instead of being transmitted inside the glass body. At this time, the sensor will not collect the light signal.

[0061] It should be noted that the light-guiding medium in the collection unit 7 can be any object or medium that can conduct light and cause the laser to reflect, scatter or diffusely reflect, such as transparent glass, optical fiber, ceramic, metal, coating, etc.

[0062] As a preferred embodiment, the shape of the light-transmitting glass 12 can be any other three-dimensional geometric shape such as a cylinder, a cuboid, a cube, a triangular prism, etc.

[0063] As a preferred embodiment, the diffuse reflection line of the diffuse reflection area is a line, a pattern or any geometric figure.

[0064] As a preferred embodiment, the photoelectric sensor is placed on one side of the light-guiding medium to collect the laser light signal. The placement position of the photoelectric sensor is not limited to the four sides of the light-guiding medium, but also includes the top, bottom or any other orientation thereof. The photoelectric sensor is arranged on the diffuse reflection circuit to receive the light after diffuse reflection.

[0065] In some embodiments, the photoelectric sensor may also be a photoelectric conversion element such as a photodiode, a photosensitive diode, or a phototransistor that can be used as a sensor to collect laser signals. The incident laser may be a laser of any wavelength. The device supports the collection of lasers of all wavelengths.

[0066] It should be noted that there are matrix holes on the top of the calibrator that correspond one-to-one to the acquisition units. The number of holes and the hole spacing can be flexibly adjusted according to actual needs. While improving the positioning accuracy, the cost of the acquisition units arranged in the matrix can be minimized.

[0067] Example 2

[0068] like Figure 4 As shown, this embodiment provides a galvanometer calibration system, including a controller 2, wherein the controller 2 is connected to a laser 4, a galvanometer 5, a calibration device and a processor 1 via a signal transmission line 3; the processor 1 is connected to the calibration device via a data acquisition line 8; wherein the calibration device adopts any galvanometer calibration device described in Example 1.

[0069] As a preferred embodiment, in the galvanometer calibration system, the number of galvanometers can be single or multiple. When the system contains multiple galvanometers that need to be calibrated, the scanning range of the multiple galvanometers after splicing needs to be close to the size of the calibration instrument in the calibration device, or the size of the calibration instrument in the calibration device is made to be equivalent to the size of the scanning area after the multiple galvanometers are spliced.

[0070] At this time, the scanning area of ​​each galvanometer is included in the range that can be collected by multiple acquisition units arranged in a matrix on the calibrator. The scanning area of ​​each galvanometer on the calibrator is specified separately through the host computer software, so that multiple galvanometers can scan on the calibrator in sequence or simultaneously. After the scanning is completed, the system automatically generates a calibration file for each galvanometer. According to the above process, single or multiple galvanometers can be calibrated on this calibrator. Therefore, this system can be used for splicing and calibration of any number of galvanometers.

[0071] As a preferred embodiment, in the calibration device, the photoelectric sensors and the light-guiding medium are arranged in a matrix on the calibrator. It should be noted that, in general, the light signal collected by the photoelectric sensor is very weak, and the converted electrical signal is also very weak. In order to reduce the impact of environmental noise and other interferences and improve the quality and reliability of the signal, it is necessary to amplify the electrical signal converted by the photoelectric sensor. The photoelectric sensor is connected to an amplifying circuit board, and all photoelectric sensors are installed on the amplifying circuit board. The amplifying circuit board is arranged inside the calibrator. The amplifying circuit board also has a communication circuit, which is used to connect the data collected by the photoelectric sensor to the processor through type-c, Bluetooth, wifi and other communication methods and transmit data.

[0072] like Figure 5 As shown, Figure 5 It shows the change in voltage signal collected by the sensor when the laser passes through the diffuse reflection area.

[0073] Example 3

[0074] This embodiment provides a laser marking device, including any galvanometer calibration system described in Embodiment 2.

[0075] The galvanometer calibration system is an indispensable part of laser marking equipment. It is mainly used to eliminate or compensate for the errors caused by the galvanometer to ensure the accuracy and stability of laser marking. Through this system, laser marking equipment can adapt to various working environments, continuously output high-quality marking results, and meet the needs of industrial production and personalized customization.

[0076] Example 4

[0077] This embodiment provides a galvanometer calibration method, which is performed by using any galvanometer calibration system described in Embodiment 2, and includes:

[0078] The processor 1 sends a calibration start instruction to the controller 2;

[0079] The controller 2 controls the laser 4 to emit laser light through control instructions, and controls the galvanometer 5 to deflect, so that the focus of the laser light sequentially scans the plurality of acquisition units 7 on the calibration instrument 6 according to a predetermined trajectory;

[0080] When the laser scans the diffuse reflection area 25 of the light-transmitting glass 12 in the light-guiding medium of each collection unit 7, the laser undergoes diffuse reflection and is scattered inside the light-transmitting glass 12. The scattered light is captured by the photoelectric sensor 16 placed on one side of the light-transmitting glass 12 and converted into an electrical signal and sent to the calibrator 6.

[0081] The calibrator 6 transmits the electrical signal to the processor 1;

[0082] The processor 1 performs filtering and fitting calculation according to the electrical signal to obtain the actual marking coordinates of the acquisition unit, compares the actual marking coordinates with the a priori coordinates sent by the controller, generates a calibration file and sends it back to the controller 2;

[0083] The controller 2 performs calibration operations on the galvanometer 5 according to the correction.

[0084] It should be noted that when the laser scans the non-diffuse reflection area 39 on the surface of the transparent glass 12, the laser passes through the transparent glass 12 and is emitted from the bottom of the transparent glass 12. At this time, the photoelectric sensor 16 will not receive any light signal.

[0085] The method of this embodiment has the following advantages:

[0086] 1. High calibration accuracy: The laser scans each acquisition unit in turn through the precise control of the galvanometer, accurately tracking the position of the laser focus. When the laser irradiates the diffuse reflection area of ​​the transparent glass, the scattered light signal is collected by the photoelectric sensor, and the processor performs filtering and fitting calculations based on the signal. This method can effectively obtain the actual deviation of the galvanometer, and generate a high-precision calibration file by comparing the prior coordinates with the actual marking coordinates.

[0087] 2. High degree of automation: The entire calibration process is automated. The system automatically adjusts the actions of the laser and galvanometer through the controller, reducing human intervention and effectively avoiding human errors. Especially in traditional manual calibration, the calibration accuracy is often unstable due to differences or errors in operators. Compared with traditional galvanometer calibration methods, automated laser scanning and data processing greatly shorten the calibration time. When the laser scans the translucent glass, real-time signal acquisition and data analysis are performed, which can quickly complete the calibration calculation and generate a correction file.

[0088] 3. Low maintenance cost: The calibration process is completely completed by the calibration instrument automatically collecting data and completing the calibration process, without the need for human intervention, which greatly reduces the calibration process and improves the calibration efficiency. In addition, the data of this process is completely collected by the calibration instrument, avoiding errors caused by manual measurement, thereby greatly improving the accuracy of galvanometer calibration.

[0089] In order to simplify the structure of the amplification circuit connecting the signal to the photoelectric sensor, in some embodiments, the matrix is ​​scanned and operated in a row-column gating manner, and only one sensor works at a time.

[0090] As a preferred embodiment, the controller controls the laser to emit laser light through control instructions, and controls the galvanometer to deflect, so that the focus of the laser scans the multiple acquisition units on the correction instrument in sequence according to a predetermined trajectory, including:

[0091] The controller 2 sends a gating instruction to the calibrator 6;

[0092] The calibrator 2 gates the sensor 16 in the acquisition unit 7 that needs to be detected according to the gate instruction;

[0093] The controller 2 controls the deflection of the galvanometer 5 according to the prior data, so that the laser scans sequentially in the diffuse reflection area 25 of the light-transmitting glass 12 in each acquisition unit 7 according to a preset track.

[0094] As a specific embodiment, the controller first selects the photoelectric sensors in the acquisition units in the matrix that need to be turned on; according to the prior data, the controller controls the galvanometer deflection, and scans the diffuse reflection area in each acquisition unit back and forth within the positive and negative offset range of the prior X-axis and Y-axis. If the scan line intersects with the line of the diffuse reflection area, the photoelectric sensor receives the scattered laser and outputs an electrical signal to the processor for storage. Each scan line is stored as a data record. After the scan is completed, the processor calculates the actual coordinates of each reference point in each acquisition unit through mathematical algorithms such as filtering and fitting, and records them.

[0095] As a preferred embodiment, the method for obtaining the priori coordinates is:

[0096] Establish a reference coordinate system based on the calibration instrument;

[0097] Using a two-dimensional measuring device, measure multiple reference positions of each acquisition unit respectively, and record the center point position of the acquisition unit;

[0098] According to the reference position and the center point position, the prior coordinates of each reference line and the center point in each acquisition unit on the calibration instrument in the reference coordinate system are determined.

[0099] As a specific example, Figure 6 As shown, firstly, a plane coordinate system is established with the calibrator 6 as the main body, and the plane coordinate system is used as the reference coordinate system.

[0100] By using the two-dimensional measuring equipment, the positions of each matrix acquisition unit X, X1, X2, Y, Y1, Y2, and L1 are measured respectively, and the coordinates of the acquisition center point C in the calibrator coordinate system are measured, and the above-mentioned reference positions are recorded, so as to know the true and accurate position and coordinates of each line and center point of each acquisition unit on the calibrator.

[0101] As a preferred embodiment, the processor calculates the actual marking coordinates of the acquisition unit according to the return time of the electrical signals at the multiple intersection points and the prior size data of the acquisition unit, including:

[0102] Calculating the scattered light guiding speed of the scattered light in the collection unit according to the first receiving time difference of the first intersection point combination among the plurality of intersection points and the priori size data of the collection unit;

[0103] The actual coordinate value of the reference line in the acquisition unit is calculated according to a plurality of second receiving time difference values ​​of a plurality of pairs of second intersection point combinations among the plurality of intersection points and the scattered light guiding speed.

[0104] As a specific example, Figure 7As shown, the controller 2 controls the galvanometer 4 to make the laser scan along the X-axis direction, and the scanning tracks are X1, X2 and X3 (the scanning path is only used for illustration, and actually can include various forms of laser scanning paths). The above laser track lines intersect with the diffuse reflection area on the light guide glass respectively, and the intersection points are Figure 7 The intersection points of a1, b1, c1, a2, b2, c2, etc.

[0105] When the laser passes through the non-diffuse reflection area (i.e., non-diffuse reflection area 39) on the light-guiding glass, the laser will not be transmitted in the light-guiding glass body but will be directly emitted through the light-guiding glass, so the photoelectric sensor will not receive the light signal at this time. When the laser passes through the diffuse reflection area on the light-guiding glass, the laser will be scattered in the glass body due to the diffuse reflection phenomenon, and the scattered light will be transmitted through the light-guiding glass and received by the photoelectric sensor arranged next to the light-guiding glass.

[0106] When the laser trajectory line is X1, the laser trajectory line X1 intersects with the diffuse reflection area pattern on the acquisition unit. The sensor senses the light signal in the diffuse reflection areas at a1, b1, and c1 respectively, and converts the light signal into an electrical signal and sends it to the processor. After receiving the signal sent back by the sensor, the processor processes and records the time of receiving the signal.

[0107] Specifically, assuming that the total time from a1 to c1 is t, since the total length from a1 to c1 has been measured on the second dimension, the length s from a1 to c1 is a known quantity. From the formula v1=s / t, we can get the average speed v1 of the laser a1 moving to c1.

[0108] Assuming that the time from a1 to b1 is t1, and the time from b1 to c1 is t1', the length from a1 to b1 △d1=t1*v1 can be calculated by t1 and v1, and the length from b1 to c1 △d1'=t1'*v1 can be calculated by t1' and v1.

[0109] Since the diffuse reflection pattern of the light-transmitting glass on the acquisition unit has been measured on the second dimension and its relative positions X, X1, X2, L1 and the coordinates of the center point C are known, the position of the laser trajectory line X1 in the diffuse reflection pattern area can be inferred by the lengths of △d1 and △d1', thereby obtaining the actual position of the X-axis of the galvanometer to control the laser to scan the trajectory line X1 on the calibrator. After repeating the operation several times, the actual position of the laser scanning of X2 and X3 can be obtained. After fitting the above position values, the errors caused by other factors can be eliminated, thereby accurately obtaining the precise position of the galvanometer scanning along the X-axis to the acquisition unit. The same method can be used to obtain the actual scanning position of the Y-axis of the galvanometer to control the laser on the calibrator.

[0110] According to the above process, the coordinates of each acquisition unit on the calibrator scanned by the laser are recorded, the position where the galvanometer actually scans on the calibrator is obtained, and a data file is generated according to certain rules.

[0111] Since the motion trajectory of the laser is controlled by the position data sent by the controller, the controller can know the theoretical position of the laser scanning to each acquisition unit on the calibration instrument. Therefore, the controller compares the actual scanning position of the laser collected with the theoretical position of the sent data, and can obtain the error between the theoretical trajectory position and the actual trajectory position of the laser.

[0112] In some embodiments, when correcting and compensating for positions where the theoretical coordinates have large errors with the actual coordinates, modeling and algorithms can be used to compensate for the errors of the galvanometer and the optical system to ensure that the laser beam can accurately reach the predetermined position. Combined with polynomial fitting, interpolation methods, or machine learning techniques, the galvanometer calibration can be flexibly implemented in different application scenarios using any of the galvanometer calibration systems described in Example 2.

[0113] Example 5

[0114] Figure 4 The galvanometer calibration system shown can also be used to monitor laser power. Since the intensity of lasers of different powers is different, when laser spots of different powers scan the diffuse reflection area of ​​the light-guiding glass, the signal intensity received by the photoelectric sensor set near the light-guiding glass is different. When the laser power increases, the signal received by the photoelectric sensor becomes stronger, and the converted voltage value becomes higher. When the laser power decreases, the signal received by the photoelectric sensor becomes weaker, and the converted voltage value becomes lower. That is, the laser power is proportional to the laser light intensity, and the laser light intensity is proportional to the signal intensity collected by the photoelectric sensor. Using the above principle, the corresponding relationship between the laser power and the signal collected by the photoelectric sensor can be found.

[0115] Therefore, when testing the power of the laser, the laser to be tested can be placed directly below the galvanometer 5 in the system. Through the controller 2, the galvanometer 5 is used to make the laser spot pass through the diffuse reflection area 25 and the non-diffuse reflection area 39 of the light-guiding medium on the collection unit 7. When the laser passes through the diffuse reflection area 25, the laser will be scattered here. The scattered laser will be transmitted through the inside of the transparent glass 12 and then received by the photoelectric sensor 16 arranged near the transparent glass 12. The photoelectric sensor 16 will receive the voltage signal and compare it with the characteristic mapping table when the system is calibrated, so as to calculate the power of the laser of the current marking system. The characteristic mapping table calibrates the system by the standard power under different values, finds out the power signal characteristics collected by the laser power detection device under each power range, and generates a corresponding value table.

[0116] The controller 2 compares the received voltage signal with the value in the mapping table, and can analyze the laser power currently output by the laser to be tested.

[0117] 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 changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A galvanometer calibration device, characterized in that: It comprises a calibrator, on which a plurality of acquisition units arranged in a matrix are installed; each acquisition unit comprises a light-guiding medium and a photoelectric sensor arranged on one side of the light-guiding medium; The light-guiding medium is provided with a diffuse reflection area and a non-diffuse reflection area inside, the diffuse reflection area includes at least one diffuse reflection line, and the photoelectric sensor is arranged on the diffuse reflection line; When the incident laser passes through the diffuse reflection area, scattering will occur, and the scattered laser light is transmitted inside the light-guiding medium. Part of the scattered laser light is received by the photoelectric sensor and converted into an electrical signal.

2. The galvanometer calibration device according to claim 1, characterized in that: The light-guiding medium is any one of a cylinder, a cuboid, a cube, a cone, a sphere, and a triangular prism.

3. The galvanometer calibration device according to claim 1, characterized in that: The diffuse reflection line of the diffuse reflection area is one of a line, a pattern or an arbitrary geometric figure.

4. A galvanometer calibration system, characterized in that: It includes a controller, which is connected to a laser, a galvanometer, a calibration device and a processor; the processor is connected to the calibration device; wherein the calibration device adopts the galvanometer calibration device as described in any one of claims 1-3.

5. A laser marking device, characterized in that: Including the galvanometer calibration system as described in right 4.

6. A galvanometer calibration method, characterized in that: The method is performed by using the galvanometer calibration system according to claim 4, comprising: The processor sends a calibration start instruction to the controller; The controller controls the laser to emit laser light through control instructions, and controls the galvanometer to deflect, so that the focus of the laser scans the plurality of acquisition units on the calibration instrument in sequence according to a predetermined trajectory; When the laser scans the diffuse reflection area in the light-guiding medium in each acquisition unit, the laser undergoes diffuse reflection and is scattered inside the light-guiding medium. The scattered light is captured by a photoelectric sensor placed on one side of the light-guiding medium and converted into an electrical signal and sent to the calibration instrument. The calibrator transmits the electrical signal to the processor; The processor performs filtering and fitting calculation on the electrical signal to obtain the actual marking coordinates of the acquisition unit, compares the actual marking coordinates with the a priori coordinates sent by the controller, generates a calibration file and sends it back to the controller; The controller performs a calibration operation on the galvanometer according to the correction.

7. The galvanometer calibration method according to claim 6, characterized in that: The controller controls the laser to emit laser light through control instructions, and controls the galvanometer to deflect, so that the focus of the laser scans the plurality of acquisition units on the calibration instrument in sequence according to a predetermined trajectory, including: The controller sends a gating instruction to the calibrator; The calibrator gates the sensors of the acquisition units to be detected according to the gate instruction; The controller controls the deflection of the galvanometer according to the prior data, so that the laser scans sequentially in the diffuse reflection area of ​​the light-guiding medium in each acquisition unit according to a preset track.

8. The galvanometer calibration method according to claim 6, characterized in that: The method for obtaining the priori coordinates is: Establish a reference coordinate system based on the calibration instrument; Using a two-dimensional measuring device, measure multiple reference positions of each acquisition unit respectively, and record the center point position of the acquisition unit; According to the reference position and the center point position, the prior coordinates of each reference line and the center point in each acquisition unit on the calibration instrument in the reference coordinate system are determined.

9. The galvanometer calibration method according to claim 8, characterized in that: The processor performs filtering and fitting calculation on the electrical signal to obtain the actual marking coordinates of the acquisition unit, including: The controller controls the galvanometer to deflect, so that the laser scans the collection unit along a preset direction, and the scanning trajectory of the laser intersects with the diffuse reflection area in the collection unit to obtain a plurality of intersection points; The laser is received by the photoelectric sensor after being scattered at each intersection point, and is converted into an electrical signal and transmitted back to the processor; The processor calculates the actual marking coordinates of the acquisition unit according to the return time of the electrical signals at the multiple intersection points and the priori size data of the acquisition unit.

10. The galvanometer calibration method according to claim 9, characterized in that: The processor calculates the actual marking coordinates of the acquisition unit according to the return time of the electrical signals at the plurality of intersection points and the priori size data of the acquisition unit, including: Calculating the scattered light guiding speed of the scattered light in the collection unit according to the first receiving time difference of the first intersection point combination among the plurality of intersection points and the priori size data of the collection unit; The actual coordinate value of the reference line in the acquisition unit is calculated according to a plurality of second receiving time difference values ​​of a plurality of pairs of second intersection point combinations among the plurality of intersection points and the scattered light guiding speed.

Images