3D Camera Galvanometer Module Motion Nonlinear Error Calibration Method and System

Abstract

The present application relates to a method for calibrating the non-linear error of the motion of a 3D camera galvanometer module. The method includes: determining a target galvanometer delay parameter for aligning the central positions of the reciprocating motion of the galvanometer motor under a preset initial camera exposure time and initial galvanometer motion time, adjusting the step to modify the camera exposure time and the galvanometer motion time to obtain the corresponding relationship between the camera exposure time and the galvanometer delay parameter, and taking the minimum non-linear error of the reciprocating motion of the galvanometer motor as the target to determine the lighting time of the laser at different positions under different camera exposure times and galvanometer motion times. According to the lighting time, the laser compensation parameters when the galvanometer motor runs to different positions at different galvanometer motion speeds are obtained. Through the present application, the problem that the forward and reverse motions of the galvanometer structured light projection in the related art have non-linear errors, resulting in inaccurate imaging, is solved. The non-linear errors existing in the forward and reverse motions are eliminated through the galvanometer delay parameter and the laser compensation parameter.

Description

Technical Field

[0001] This application relates to the field of camera calibration, and particularly to a method and system for calibrating the motion non-linear error of a 3D camera galvanometer module. Background Art

[0002] With the development of science and technology, the vision industry has developed rapidly, and the market demand for 3D cameras is increasing. 3D cameras can be divided into structured light cameras and line scan cameras according to the imaging principle. Among them, structured light cameras can be divided into laser galvanometer modules, DLP modules, MEMS laser modules, speckle projectors, etc. according to different projection modules.

[0003] In previous projection modules, the laser galvanometer module usually projects only in one direction, resulting in a large time loss for each projection and low overall point cloud acquisition efficiency. If structured light sequences are directly projected during the round-trip motion of the galvanometer, when performing point cloud operations, due to certain non-linear errors in the forward and reverse motions, there will be a large number of holes in the image caused by calculation failures.

[0004] Currently, for the problem of inaccurate imaging caused by non-linear errors in the forward and reverse motions of the galvanometer structured light projection in the related art, no effective solution has been proposed. Summary of the Invention

[0005] Embodiments of this application provide a method, system, electronic device, and storage medium for calibrating the motion non-linear error of a 3D camera galvanometer module, so as to at least solve the problem of inaccurate imaging caused by non-linear errors in the forward and reverse motions of the galvanometer structured light projection in the related art.

[0006] In a first aspect, embodiments of this application provide a method for calibrating the motion non-linear error of a 3D camera galvanometer module, the method including:

[0007] Determine a target galvanometer delay parameter for aligning the center positions of the round-trip motion of the galvanometer motor under a preset initial camera exposure time and a preset initial galvanometer motion time;

[0008] Adjust the step to modify the camera exposure time and the galvanometer motion time to obtain the corresponding relationship between the camera exposure time and the galvanometer delay parameter, where the camera exposure time needs to cover the motion cycle of the galvanometer motor;

[0009] Under different camera exposure times and galvanometer motion times, with the goal of minimizing the non-linear error of the round-trip motion of the galvanometer motor, determine the lighting times of the laser at different positions;

[0010] According to the lighting times, obtain the laser compensation parameters when the galvanometer motor runs to different positions at different galvanometer motion speeds.

[0011] In some of these embodiments, the determining of the target galvanometer delay parameter for aligning the central position of the reciprocating movement of the galvanometer motor includes:

[0012] Obtain a first forward and reverse error corresponding to a first galvanometer delay parameter and a second forward and reverse error corresponding to a second galvanometer delay parameter, where the first galvanometer delay parameter is 0, and the second galvanometer delay parameter needs to be adjusted according to the actual situation so that the product of the first forward and reverse error and the second forward and reverse error is less than 0;

[0013] Between the first galvanometer delay parameter and the second galvanometer delay parameter, determine the target galvanometer delay parameter that minimizes the forward and reverse error through the bisection method.

[0014] In some of these embodiments, the obtaining of the first forward and reverse error corresponding to the first galvanometer delay parameter includes:

[0015] Set the galvanometer delay of the galvanometer motor according to the first galvanometer delay parameter, and collect multiple forward movement images and reverse movement images;

[0016] Based on the forward movement images and the reverse movement images, obtain the first forward and reverse movement error.

[0017] In some of these embodiments, the obtaining of the first forward and reverse movement error based on the forward movement images and the reverse movement images includes:

[0018] Based on the forward movement images and the reverse movement images, determine the horizontal coordinate of the single fringe light at the center of the forward movement and the horizontal coordinate of the single fringe light at the center of the reverse movement;

[0019] Take the average value of the horizontal coordinates of the single fringe light at the center of the forward movement to obtain the forward movement coordinate;

[0020] Take the average value of the horizontal coordinates of the single fringe light at the center of the reverse movement to obtain the reverse movement coordinate;

[0021] Based on the forward movement coordinate and the reverse movement coordinate, obtain the first forward and reverse movement error.

[0022] In some of these embodiments, the determining of the lighting time of the laser at different positions with the goal of minimizing the non-linear error of the reciprocating movement of the galvanometer motor includes:

[0023] Based on a preset laser galvanometer controller sequence diagram, control the galvanometer motor to perform forward and reverse movement, obtain a first non-linear error between the actual position and the theoretical position of each laser scan line during the forward movement, and a second non-linear error between the actual position and the theoretical position of the laser scan line during the reverse movement, where the preset laser galvanometer controller sequence diagram annotates the theoretical positions of each of the laser scan lines;

[0024] Based on the piecewise linear interpolation method and non-linear piecewise linear fitting, with the goal of minimizing the first non-linear error and the first non-linear error, determine the lighting time of the laser at different positions.

[0025] In a second aspect, an embodiment of the present application provides a 3D camera galvanometer module motion non-linear error calibration system, which includes: a fixing device, a 2D camera, an embedded computing module, and a galvanometer motor to be calibrated.

[0026] The fixing device is used to fix the galvanometer motor to be calibrated in a detachable manner.

[0027] The 2D camera is used to collect the forward and reverse motion images of the galvanometer motor to be calibrated.

[0028] The embedded computing module is respectively communicatively connected to the 2D camera and the galvanometer motor to be calibrated, and is used to control the galvanometer motor to be calibrated and the 2D camera, and calibrate the delay parameters and laser compensation parameters of the galvanometer motor to be calibrated by the 3D camera galvanometer module motion non-linear error calibration method described in the first aspect.

[0029] In some embodiments, the system further includes a host computer, which is communicatively connected to the embedded computing module, and is used to receive the delay parameter calibration result and the laser compensation parameter calibration result uploaded by the embedded computing module, and associate the serial number of the galvanometer motor to be calibrated with the delay parameter calibration result and the laser compensation parameter calibration result.

[0030] In some embodiments, the system further includes a display module, which is used to display the forward and reverse motion images.

[0031] In a third aspect, an embodiment of the present application provides a computer device, which includes a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, it implements the 3D camera galvanometer module motion non-linear error calibration method described in the first aspect above.

[0032] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, it implements the 3D camera galvanometer module motion non-linear error calibration method described in the first aspect above.

[0033] Compared with the related art, the 3D camera galvanometer module motion nonlinear error calibration method provided by the embodiments of the present application determines the target galvanometer delay parameter that aligns the center positions of the reciprocating motion of the galvanometer motor under the preset initial camera exposure time and the preset initial galvanometer motion time, adjusts the step-by-step modified camera exposure time and the galvanometer motion time, and obtains the corresponding relationship between the camera exposure time and the galvanometer delay parameter. Among them, the camera exposure time needs to cover the motion cycle of the galvanometer motor. Under different camera exposure times and galvanometer motion times, with the goal of minimizing the nonlinear error of the reciprocating motion of the galvanometer motor, the lighting time of the laser at different positions is determined. According to the lighting time, the laser compensation parameters when the galvanometer motor runs to different positions at different galvanometer motion speeds are obtained, solving the problem in the related art that the forward and reverse motions of the galvanometer structured light projection have nonlinear errors, resulting in inaccurate imaging. The galvanometer delay parameter and the laser compensation parameter are obtained, and the reciprocating motion is roughly calibrated using the galvanometer delay parameter, and precise calibration is performed using the laser compensation parameter, thereby eliminating the nonlinear error existing in the forward and reverse motions. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation to the present application. In the drawings:

[0035] Figure 1 is a flowchart of the 3D camera galvanometer module motion nonlinear error calibration method according to the embodiments of the present application;

[0036] Figure 2 is a flowchart of a galvanometer delay parameter calibration according to the embodiments of the present application;

[0037] Figure 3 is a flowchart of a laser compensation parameter calibration according to the embodiments of the present application;

[0038] Figure 4 is a structural block diagram of the 3D camera galvanometer module motion nonlinear error calibration system according to the embodiments of the present application;

[0039] Figure 5 is a schematic diagram of the 3D camera galvanometer module motion nonlinear error calibration system according to the embodiments of the present application;

[0040] Figure 6 is an internal structural schematic diagram of an electronic device according to the embodiments of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0041] In order to make the objectives, technical solutions and advantages of the present application more clear and understandable, the present application will be described and explained below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments provided in the present application without creative efforts fall within the scope of protection of the present application.

[0042] Obviously, the accompanying drawings in the following description are only some examples or embodiments of the present application. For those of ordinary skill in the art, without creative efforts, the present application can also be applied to other similar scenarios based on these drawings. In addition, it can also be understood that although the efforts made in such a development process may be complex and lengthy, for those of ordinary skill in the art related to the content disclosed in the present application, some designs, manufacturing or production changes made based on the technical content disclosed in the present application are only conventional technical means and should not be understood as the content disclosed in the present application being insufficient.

[0043] Referring to "embodiments" in the present application means that the specific features, structures or characteristics described in connection with the embodiments may be included in at least one embodiment of the present application. The phrase appears in various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those of ordinary skill in the art explicitly and implicitly understand that the embodiments described in the present application can be combined with other embodiments without conflict.

[0044] Unless otherwise defined, the technical terms or scientific terms involved in this application shall have the ordinary meanings understood by those with ordinary skills in the technical field to which this application belongs. The words such as "a", "an", "one kind", "the" and the like involved in this application do not indicate a quantity limit and may represent a singular or plural number. The terms "including", "comprising", "having" and any variations thereof involved in this application are intended to cover non-exclusive inclusion; for example, a process, method, system, product or device including a series of steps or modules (units) is not limited to the listed steps or units, but may further include steps or units not listed, or may further include other steps or units inherent to these processes, methods, products or devices. The words such as "connected", "linked", "coupled" and the like involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The "multiple" involved in this application means two or more. "And / or" describes the association relationship of associated objects and indicates that three relationships may exist. For example, "A and / or B" may represent: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally represents an "or" relationship between the front and rear associated objects. The terms "first", "second", "third" and the like involved in this application are only used to distinguish similar objects and do not represent a specific sorting of the objects.

[0045] This embodiment provides a method for calibrating the motion non-linear error of a 3D camera galvanometer module. Figure 1 is a flowchart of the method for calibrating the motion non-linear error of a 3D camera galvanometer module according to an embodiment of the present application, as Figure 1 shown, and this process includes the following steps:

[0046] Step S101, at a preset initial camera exposure time and a preset initial galvanometer motion time, determine a target galvanometer delay parameter for aligning the center positions of the forward and backward motions of the galvanometer motor.

[0047] Before calibrating the galvanometer delay parameter, when the laser makes a forward and return motion through the galvanometer, due to the delay mismatch, the problem of non-coincidence of the picture centers will occur. In order to simplify the non-linear calibration, it is necessary to first align the picture centers.

[0048] Set the initial camera exposure time t cexp and the galvanometer motion time t mexp , where the camera exposure time should cover the galvanometer motion period. After the galvanometer control module outputs a center single stripe of light, calibrate the galvanometer delay parameter.

[0049] In some embodiments, step S101 specifically includes:

[0050] Step S1011: Obtain the first forward and reverse process errors corresponding to the first galvanometer delay parameter and the second forward and reverse process errors corresponding to the second galvanometer delay parameter. The first galvanometer delay parameter is 0, and the second galvanometer delay parameter needs to be adjusted according to the actual situation so that the product of the first forward and reverse process errors and the second forward and reverse process errors is less than 0.

[0051] Set the first galvanometer delay parameter t1 to 0, and obtain the forward and reverse process errors of the galvanometer movement when t1 = 0, that is, the first forward and reverse process errors.

[0052] In some embodiments, obtaining the first forward and reverse process errors corresponding to the first galvanometer delay parameter in step S1011 includes:

[0053] Step S201: Set the galvanometer delay of the galvanometer motor according to the first galvanometer delay parameter, and collect multiple forward process motion images and reverse process motion images.

[0054] Step S202: Based on the forward process motion images and the reverse process motion images, obtain the first forward and reverse process motion errors.

[0055] In some embodiments, step S202 specifically includes:

[0056] Step S2021: Based on the forward process motion images and the reverse process motion images, determine the horizontal coordinates of the single fringe light at the center of the forward process motion and the horizontal coordinates of the single fringe light at the center of the reverse process motion.

[0057] Step S2022: Take the average value of the horizontal coordinates of the single fringe light at the center of the forward process motion to obtain the forward process motion coordinates.

[0058] Step S2023: Take the average value of the horizontal coordinates of the single fringe light at the center of the reverse process motion to obtain the reverse process motion coordinates.

[0059] Step S2024: Based on the forward process motion coordinates and the reverse process motion coordinates, obtain the first forward and reverse process motion errors.

[0060] Collect M forward and reverse process motion images each, calculate the horizontal coordinates of the single fringe light at the center of the forward and reverse process motions and take the average value. The first forward and reverse process motion error e1 = X p - X n , where X p is the forward process motion coordinate, and X n is the reverse process motion coordinate.

[0061] According to the above method of obtaining the first forward and reverse process motion errors, measure the second forward and reverse process motion error e2 corresponding to the second galvanometer delay parameter t2. The value of the second galvanometer delay parameter t2 needs to be adjusted according to the actual test to satisfy e1×e2 < 0.

[0062] Step S1012, between the first galvanometer delay parameter and the second galvanometer delay parameter, determine the target galvanometer delay parameter that minimizes the forward and reverse travel errors through the bisection method.

[0063] Between (t1, e1) and (t2, e2), there is a monotonic relationship between the galvanometer delay parameter and the motion error. Use the bisection method to find the appropriate galvanometer delay parameter t c , such that the galvanometer delay t = t c When, the forward and reverse travel motion error e = 0 or e is minimized. At this time, t c Is the optimal delay under the galvanometer motion time t mexp , that is, the target galvanometer delay parameter.

[0064] Continue to refer to Figure 1 , after determining the target galvanometer delay parameter under the preset initial camera exposure time and the preset initial galvanometer motion time, execute step S102.

[0065] Step S102, adjust the camera exposure time and the galvanometer motion time step by step to obtain the corresponding relationship between the camera exposure time and the galvanometer delay parameter, where the camera exposure time needs to cover the motion cycle of the galvanometer motor.

[0066] By adjusting the step, modify the camera exposure time and the galvanometer motion time, repeat the above operations, determine the target galvanometer delay parameter under each camera exposure time and galvanometer motion time, complete the calibration of the delay parameter within the entire exposure range, and obtain the corresponding relationship (T sequence) between the camera exposure time and the galvanometer delay parameter. Figure 2 Is a flowchart of calibrating the galvanometer delay parameter according to an embodiment of the present application.

[0067] Step S103, at different camera exposure times and galvanometer motion times, with the goal of minimizing the non-linear error of the reciprocating motion of the galvanometer motor, determine the lighting time of the laser at different positions.

[0068] Through the above calibration of the galvanometer delay parameter, after aligning the central positions of the reciprocating motion of the galvanometer motor, use the piecewise linear fitting method for fitting compensation, calibrate the laser compensation parameter, and further calibrate the error. It is found during the experiment that the lighting delay of the laser is relatively stable relative to the motion of the galvanometer motor. Therefore, in this embodiment, by adjusting the lighting time of the laser at different positions, the non-linearity of the motor is compensated.

[0069] In some of these embodiments, step S103 specifically includes:

[0070] Step S1031: Control the galvanometer motor to perform forward and reverse strokes based on the preset galvanometer controller sequence diagram, and obtain the first non-linear error between the actual position and the theoretical position of each laser scanning line during the forward stroke, and the second non-linear error between the actual position and the theoretical position of the laser scanning line during the reverse stroke. Among them, the preset galvanometer controller sequence diagram marks the theoretical position of each laser scanning line.

[0071] Step S1032: Based on the piecewise linear interpolation method and non-linear piecewise linear fitting, with the goal of minimizing the first non-linear error and the first non-linear error, determine the lighting time of the laser at different positions.

[0072] The galvanometer movement is divided into a preset number (n) of partitions, and the sequence diagram of the galvanometer controller is in the mode of n + 1 laser scanning lines (the laser scanning lines are located at the edges of each partition). Define the laser scanning lines as L0~L 16 , one forward movement is P, the reverse movement is N, and the nth laser scanning line during the forward stroke is L pn . Define X(L pn ) as the actual position of the laser scanning line L pn in the image, and X(n) as the theoretical position of the nth laser scanning line.

[0073] In the case where there is no non-linear error in the galvanometer, L pn and L n(16-n) should completely coincide. Due to the actual existence of non-linear errors, the non-linear error is defined as:

[0074] e pn = ABS(X(L pn ) - X(n))

[0075] e nn = ABS(X(L n(16-n) ) - X(n))

[0076] Among them, e pn is the non-linear error of the nth laser scanning line during the forward stroke, e nn is the non-linear error of the nth laser scanning line during the reverse stroke, X(L n(16-n) ) is the actual position of the (16 - n)th laser scanning line in the image during the reverse stroke, and ABS() represents the absolute value.

[0077] Obtain a set of lighting time sequences S p of the laser during the forward stroke of the galvanometer and the lighting time sequence S n during the reverse stroke of the galvanometer through a preset algorithm, so that E p = (e p0 , e p1 ,..., e p16 ) and En =(e n0 , e n1 ,..., e n16 ) are all 0 or reach the minimum value. Optionally, the preset algorithm is the bisection method or piecewise linear interpolation.

[0078] Calculate the laser lighting time within the entire motion range. Taking the nth interval of forward motion as an example:

[0079]

[0080] Among them, S p is the time after linear fitting when the galvanometer moves to the x p position; S pn is the time when the galvanometer moves to the nth laser scan line, S pn+1 is the time when the galvanometer moves to the (n + 1)th laser scan line, and S full is the total time of moving from left to right. Through n + 1 time points, the time points of the entire range are piecewise fitted.

[0081] Calculate the lighting time of the return motion by the same method, and perform non-linear piecewise linear fitting within the global range.

[0082] Step S104, according to the lighting time, obtain the laser compensation parameters when the galvanometer motor runs to different positions at different galvanometer motion speeds.

[0083] Calibrate under different exposures to obtain two sets of data Spmexp(exp, pn), Snmexp(exp, nn), where exp is the time for the galvanometer to move from left to right, pn is the nth laser scan line of forward motion, nn is the nth laser scan line of reverse motion, Spmexp(exp, pn) is the lighting time sequence of the forward motion under different exposures, and Snmexp(exp, nn) is the lighting time sequence of the reverse motion under different exposures. Thus, the laser compensation parameters when the galvanometer motor runs to different positions at different galvanometer motion speeds are obtained. Figure 3 is a flowchart of calibrating laser compensation parameters according to an embodiment of the present application.

[0084] When performing projection, linear interpolation can be performed according to the calibrated time parameters to obtain the corresponding real time; in engineering implementation, for the operation during the process, the combined values of all exposures and positions can be calculated according to Spmexp(exp, pn), Snmexp(exp, nn), and look-up table processing can be performed to achieve the purpose of calibrating the non-linear error of the 3D camera galvanometer module motion.

[0085] The method of piecewise linear interpolation and the application of the look-up table method enable calibration of not all positions and exposure values during the calibration process, reducing the calibration time and improving the efficiency of error elimination.

[0086] Through the above steps, at the preset initial camera exposure time and the preset initial galvanometer movement time, determine the target galvanometer delay parameter that aligns the center position of the reciprocating movement of the galvanometer motor, adjust the step to modify the camera exposure time and the galvanometer movement time, and obtain the corresponding relationship between the camera exposure time and the galvanometer delay parameter. Among them, the camera exposure time needs to cover the movement cycle of the galvanometer motor. At different camera exposure times and galvanometer movement times, with the goal of minimizing the non-linear error of the reciprocating movement of the galvanometer motor, determine the lighting time of the laser at different positions. According to the lighting time, obtain the laser compensation parameter when the galvanometer motor runs to different positions at different galvanometer movement speeds, solving the problem in the related technology that the forward and reverse movements of the galvanometer structured light projection have non-linear errors resulting in inaccurate imaging. Obtain the galvanometer delay parameter and the laser compensation parameter, use the galvanometer delay parameter to perform rough calibration on the reciprocating movement, and use the laser compensation parameter to perform precise calibration, thereby eliminating the non-linear error existing in the forward and reverse movements.

[0087] Improve the galvanometer movement efficiency and the maximum frame rate through reciprocating movement; perform rough positioning on the reciprocating movement based on the calibration of the galvanometer delay parameter; based on the laser compensation parameter, control the lighting duration of the laser for non-linear calibration, improve the structured light accuracy, eliminate the matching problem caused by non-linearity in the reciprocating movement, and improve the point cloud quality generated by the galvanometer motor.

[0088] It should be noted that the steps shown in the above process or the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. And although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0089] This embodiment also provides a 3D camera galvanometer module motion non-linear error calibration system, which is used to implement the above embodiment and the preferred implementation manner, and those that have been described will not be repeated. As used below, terms such as "module", "unit", "sub-unit", etc. can be a combination of software and / or hardware that can achieve a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, implementation in hardware, or a combination of software and hardware is also possible and contemplated.

[0090] Figure 4 is a structural block diagram of a 3D camera galvanometer module motion non-linear error calibration system according to an embodiment of the present application, as Figure 4 shown, the system includes: a fixing device 41, a 2D camera 42, an embedded computing module 43, and a galvanometer motor 44 to be calibrated.

[0091] The fixing device 41 is used to fix the galvanometer motor 44 to be calibrated in a detachable manner.

[0092] The platform of the galvanometer motor laser module to be calibrated is fixed by the fixing device 41, and the calibration module can be quickly switched.

[0093] The 2D camera 42 is used to collect the forward and reverse movement images of the galvanometer motor 44 to be calibrated.

[0094] During the calibration process, the forward and reverse movement images of the galvanometer motor to be calibrated are captured by the 2D camera.

[0095] The embedded computing module 43 is communicatively connected to the 2D camera 42 and the galvanometer motor 44 to be calibrated respectively, and is used to control the galvanometer motor 44 to be calibrated and the 2D camera 42, and perform delay parameter calibration and laser compensator parameter calibration on the galvanometer motor to be calibrated through the above-mentioned 3D camera galvanometer module motion non-linear error calibration method.

[0096] The galvanometer motor 44 to be calibrated includes an FPGA-based laser and a galvanometer control module, and the galvanometer control module includes a galvanometer controller and a laser controller.

[0097] In some embodiments, the system further includes a host computer 45, which is communicatively connected to the embedded computing module 43, and is used to receive the delay parameter calibration result and the laser compensator parameter calibration result uploaded by the embedded computing module 43, and associate the serial number of the galvanometer motor to be calibrated with the delay parameter calibration result and the laser compensator parameter calibration result.

[0098] The host computer 45 is used to count and backup the calibration results, and store the calibration data according to the serial number of the corresponding galvanometer motor. The parameter sequences T, Spmexp(exp, pn), Snmexp(exp, nn) are saved on the host computer for subsequent assembly production.

[0099] Optionally, a calibration program is set on the host computer. After the galvanometer motor to be calibrated is installed on the fixing device, the calibration process is controlled through the calibration program on the host computer.

[0100] In some embodiments, the system further includes a display module, which is used to display the forward and reverse movement images.

[0101] Figure 5 It is a schematic diagram of a 3D camera galvanometer module motion non-linear error calibration system according to an embodiment of the present application.

[0102] Through the above system, the galvanometer delay parameter and the laser compensation parameter are obtained. The reciprocating motion is roughly calibrated using the galvanometer delay parameter, and precise calibration is performed using the laser compensation parameter, thereby eliminating the non-linear error existing in the forward and reverse motions and solving the problem of inaccurate imaging caused by the non-linear error existing in the forward and reverse motions of the galvanometer structured light projection in the related art.

[0103] It should be noted that the above-mentioned various modules can be functional modules or program modules, and can be implemented either by software or by hardware. For the modules implemented by hardware, the above-mentioned various modules can be located in the same processor; or the above-mentioned various modules can also be located in different processors in any combined form.

[0104] This embodiment also provides an electronic device, including a memory and a processor. A computer program is stored in the memory, and the processor is configured to run the computer program to execute the steps in any one of the above method embodiments.

[0105] Optionally, the above-mentioned electronic device may further include a transmission device and an input / output device. Among them, the transmission device is connected to the above-mentioned processor, and the input / output device is connected to the above-mentioned processor.

[0106] Optionally, in this embodiment, the above-mentioned processor may be configured to execute the following steps through a computer program:

[0107] S1. Under the preset initial camera exposure time and the preset initial galvanometer movement time, determine the target galvanometer delay parameter that aligns the center positions of the reciprocating movement of the galvanometer motor.

[0108] S2. Adjust the step-by-step modified camera exposure time and galvanometer movement time to obtain the corresponding relationship between the camera exposure time and the galvanometer delay parameter, where the camera exposure time needs to cover the movement period of the galvanometer motor.

[0109] S3. Under different camera exposure times and galvanometer movement times, with the goal of minimizing the non-linear error of the reciprocating movement of the galvanometer motor, determine the lighting time of the laser at different positions.

[0110] S4. According to the lighting time, obtain the laser compensation parameters when the galvanometer motor runs to different positions at different galvanometer movement speeds.

[0111] It should be noted that the specific examples in this embodiment can refer to the examples described in the above embodiment and the optional implementation manners, and will not be repeated here.

[0112] In one embodiment, Figure 6 is a schematic internal structure diagram of an electronic device according to an embodiment of the present application, as Figure 6As shown, an electronic device is provided. The electronic device may be a server, and its internal structure diagram may be as shown in Figure 6 shown. The electronic device includes a processor, a memory, a network interface, and a database connected through a system bus. Among them, the processor of the electronic device is used to provide computing and control capabilities. The memory of the electronic device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the electronic device is used to store data. The network interface of the electronic device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, it implements a method for calibrating the non-linear error of the movement of a 3D camera galvanometer module.

[0113] Those skilled in the art can understand that Figure 4 the structure shown in is only a block diagram of some structures related to the solution of this application, and does not constitute a limitation on the electronic device to which the solution of this application is applied. The specific electronic device may include more or fewer components than those shown in the figure, or combine some components, or have different component arrangements.

[0114] Those of ordinary skill in the art can understand that all or part of the processes in the above method embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it may include the processes of the above method embodiments. Among them, any reference to the memory, storage, database, or other media used in the embodiments provided in this application may include non-volatile and / or volatile memories. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0115] Those skilled in the art should understand that the technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope described in this specification.

[0116] The above-described embodiments only express several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. A method for calibrating the nonlinear error of a 3D camera galvanometer module motion, characterized in that: The method comprises: Under a preset initial camera exposure time and a preset initial galvanometer movement time, determining a target galvanometer delay parameter that aligns the center position of the galvanometer motor's reciprocating motion; Adjust the stepping modification camera exposure time and the galvanometer movement time to obtain the corresponding relationship between the camera exposure time and the galvanometer delay parameter, wherein the camera exposure time needs to cover the movement period of the galvanometer motor; Under different camera exposure times and galvanometer movement times, the laser lighting time at different positions is determined with the goal of minimizing the nonlinear error of the galvanometer motor's reciprocating motion; According to the lighting time, laser compensation parameters are obtained when the galvanometer motor runs to different positions at different galvanometer movement speeds.

2. The method according to claim 1, characterized in that Determining the target galvanometer delay parameter that aligns the center position of the galvanometer motor's reciprocating motion comprises: Obtain a first forward and reverse error corresponding to a first galvanometer delay parameter and a second forward and reverse error corresponding to a second galvanometer delay parameter, wherein the first galvanometer delay parameter is 0, and the second galvanometer delay parameter needs to be adjusted according to actual conditions so that the product of the first forward and reverse error and the second forward and reverse error is less than 0; Between the first galvanometer delay parameter and the second galvanometer delay parameter, a target galvanometer delay parameter that minimizes the forward and reverse path errors is determined by dichotomy.

3. The method according to claim 2, characterized in that The step of obtaining the first forward and reverse error corresponding to the first galvanometer delay parameter comprises: Setting the galvanometer delay of the galvanometer motor according to the first galvanometer delay parameter, and collecting a plurality of forward motion images and reverse motion images; The first forward and reverse errors are obtained based on the forward motion image and the reverse motion image.

4. The method according to claim 3, characterized in that: The obtaining the first forward and reverse motion errors based on the forward motion image and the reverse motion image comprises: Based on the forward motion image and the reverse motion image, determining the horizontal coordinates of the single stripe light at the center of the forward motion and the horizontal coordinates of the single stripe light at the center of the reverse motion; Taking the average of the horizontal coordinates of the single stripe light at the center of the positive motion to obtain the positive motion coordinates; Taking an average of the horizontal coordinates of the single stripe light at the center of the reverse motion to obtain the reverse motion coordinates; The first forward and reverse motion errors are obtained according to the forward motion coordinates and the reverse motion coordinates.

5. The method according to claim 1, characterized in that The step of determining the lighting time of the laser at different positions with the goal of minimizing the nonlinear error of the reciprocating motion of the galvanometer motor comprises: Based on a preset laser galvanometer controller sequence diagram, the galvanometer motor is controlled to perform forward and reverse motion, and a first nonlinear error between the actual position and the theoretical position of each laser scanning line in the forward motion and a second nonlinear error between the actual position and the theoretical position of the laser scanning line in the reverse motion are obtained, wherein the preset laser galvanometer controller sequence diagram is marked with the theoretical position of each laser scanning line; Based on piecewise linear interpolation and nonlinear piecewise linear fitting, the lighting time of the laser at different positions is determined with the goal of minimizing the first nonlinear error and the first nonlinear error.

6. A 3D camera galvanometer module motion nonlinear error calibration system, characterized in that: The system includes: a fixing device, a 2D camera, an embedded computing module and a galvanometer motor to be calibrated. The fixing device is used to fix the galvanometer motor to be calibrated in a detachable manner; The 2D camera is used to collect forward and reverse motion images of the galvanometer motor to be calibrated; The embedded computing module is respectively connected to the 2D camera and the galvanometer motor to be calibrated for communication, and is used to control the galvanometer motor to be calibrated and the 2D camera, and performs delay parameter calibration and laser compensation parameter calibration on the galvanometer motor to be calibrated through the 3D camera galvanometer module motion nonlinear error calibration method described in any one of claims 1 to 5.

7. The system according to claim 6, characterized in that The system also includes a host computer, which is communicatively connected to the embedded computing module and is used to receive the delay parameter calibration results and laser compensation parameter calibration results uploaded by the embedded computing module, and associate the serial number of the galvanometer motor to be calibrated with the delay parameter calibration results and laser compensation parameter calibration results.

8. The system according to claim 6, characterized in that The system also includes a display module, which is used to display the forward and reverse motion images.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method for calibrating the motion nonlinear error of a 3D camera galvanometer module according to any one of claims 1 to 5 is implemented.

10. A storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method for calibrating the motion nonlinear error of a 3D camera galvanometer module as described in any one of claims 1 to 5 is implemented.

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