Three-dimensional reconstruction method, system and medium based on laser-polygonal reflective mirror

Abstract

Embodiments of the present invention disclose a three-dimensional reconstruction method, system, and medium based on a laser-polyhedron mirror. The method includes: acquiring a line laser; changing the offset angle of the line laser by synchronously controlling the laser power and the rotation angle of the polyhedron mirror to output a multimodal laser coding pattern; determining a signal compensation amount based on the nonlinear relationship between the imaging end spatial coordinates and the offset angle of the line laser, as well as the coordinate relationship between the initial reflection surface and the rotating reflection surface; compensating the multimodal laser coding image based on the signal compensation amount, and outputting a target multimodal laser coding image; and reconstructing three-dimensional coordinates based on the target multimodal laser coding pattern. The signal compensation amount is accurately determined based on the nonlinear relationship between the imaging end spatial coordinates and the offset angle of the line laser, as well as the coordinate relationship between the initial reflection surface and the rotating reflection surface, eliminating measurement deviations caused by system errors or environmental factors.

Description

Technical Field

[0001] The present invention relates to the field of three-dimensional sensing measurement technology, and in particular to a three-dimensional reconstruction method, system and medium based on laser-polyhedral reflecting mirror. Background Art

[0002] Currently, most structured light 3D sensors are based on DLP projection (Digital Light Processing), which can achieve good results for precision measurement under ideal working conditions. However, in complex, large-field-of-view applications, such as industrial robot sorting, welding, and gluing, DLP's brightness struggles, affecting 3D measurement results. Complex scenarios can include strong ambient light interference and the presence of complex materials such as black or highly reflective surfaces on the scanned object. Therefore, it is necessary to develop structured light 3D sensing measurement technology using lasers as the light source.

[0003] Existing sensing technologies primarily include laser + MEMS (Micro-Electro-Mechanical System) and laser + mechanical galvanometer. Laser + MEMS offers advantages such as small size and low cost, but suffers from lower laser intensity and poorer accuracy. Laser + mechanical galvanometer technology can increase laser intensity, further improving accuracy compared to MEMS, but is limited by the speed of the mechanical galvanometer, resulting in lower scanning speeds. Therefore, we propose a laser + high-speed mirror sensing technology to overcome the galvanometer scanning speed limitations. We also propose a multimodal 3D scanning technology to further improve measurement accuracy, robustness, and universality. Summary of the Invention

[0004] Based on this, it is necessary to address the above problems and propose a three-dimensional reconstruction method, system and medium based on laser-polygonal reflective rotating mirror. A three-dimensional reconstruction method based on laser-polygonal reflective rotating mirror, the method includes:

[0005] Collect line laser.

[0006] The offset angle of the line laser is changed by synchronously controlling the laser power and the rotation angle of the multi-faceted reflective mirror to output a multi-modal laser coding pattern.

[0007] The signal compensation amount is determined according to the nonlinear relationship between the imaging end space coordinates and the offset angle of the line laser and the coordinate relationship between the initial reflection surface and the rotating reflection surface.

[0008] The multimodal laser coding pattern is compensated according to the signal compensation amount, and a target multimodal laser coding pattern is output.

[0009] The three-dimensional coordinates are reconstructed according to the target multimodal laser coding pattern.

[0010] The signal compensation amount is determined according to the nonlinear relationship between the imaging end space coordinates and the offset angle of the line laser and the coordinate relationship between the initial reflection surface and the rotating reflection surface, specifically including:

[0011] The nonlinear relationship between the spatial coordinates of the imaging end and the offset angle of the line laser is determined.

[0012] An expression for a multi-modal laser coding pattern output by the imaging end is determined according to the nonlinear relationship.

[0013] An input end signal compensation expression is determined according to the relationship between the multimodal laser coding pattern expression and the imaging end target output.

[0014] Determine the coordinate relationship between the initial reflection surface and the rotating reflection surface.

[0015] Based on the coordinate relationship between the initial reflection surface and the rotation reflection surface, the rotation reflection surface coordinate model is determined according to the input end signal compensation expression.

[0016] The spatial offset is determined according to the rotating reflective surface coordinate model.

[0017] Based on the nonlinear relationship, the line laser offset is determined according to the spatial offset.

[0018] The line laser offset is substituted into the input end signal compensation expression to determine the signal compensation amount.

[0019] The step of determining the input end signal compensation expression based on the relationship between the multimodal laser coding pattern expression and the imaging end target output specifically includes:

[0020] according to Determine the input signal compensation expression, where is the signal compensation amount, is the target output of the imaging end, is the nonlinear relationship between the spatial coordinates of the imaging end and the offset angle of the line laser, w is the rotation speed of the mirror, is the rotation angle.

[0021] The line laser offset is substituted into the input end signal compensation expression to determine the signal compensation amount, specifically including:

[0022] The signal compensation amount is based on Determine, among which, is the signal compensation amount, is the target output of the imaging end, is the rotation angle, a is the intercept of the initial reflection surface in the plane rectangular coordinate system, d is the vertical distance from the laser light source to the center of the reflection mirror, and D is the projection distance of the line laser moving along the positive direction of the longitudinal axis after being deflected by the initial reflection surface.

[0023] The reconstructing of three-dimensional coordinates according to the target multimodal laser coding pattern specifically includes:

[0024] The target multimodal laser coding pattern includes a single line of laser light.

[0025] An image processing algorithm is used to extract the center of the light stripe of the single-line laser, and to determine the sub-pixel precision coordinates of the single-line laser in an image coordinate system.

[0026] The sub-pixel precision coordinates are converted to an image plane in a camera coordinate system using camera intrinsic parameters.

[0027] For any image point on the image plane, a ray from the origin of the image plane to the image point is determined.

[0028] The three-dimensional coordinates of the current image point are reconstructed by determining the spatial intersection point of the ray and the single-line laser light plane.

[0029] The reconstructing of three-dimensional coordinates according to the target multimodal laser coding pattern specifically includes:

[0030] The target multi-modal laser coding pattern includes multi-line laser and Gray code.

[0031] The multi-line laser is encoded using the Gray code to determine the light plane parameters of the multi-line laser.

[0032] The light plane equation of the multi-line laser is determined according to the light plane parameters of the multi-line laser.

[0033] An image processing algorithm is used to extract the center of each line of laser light in the multi-line laser, and to determine the sub-pixel precision coordinates of the multi-line laser in an image coordinate system.

[0034] The sub-pixel precision coordinates are converted to an image plane in a camera coordinate system using camera intrinsic parameters.

[0035] For any image point on the image plane, a ray from the origin of the image plane to the image point is determined.

[0036] The three-dimensional coordinates of the current image point are reconstructed by determining the spatial intersection point of the ray of the image point and the light plane equation of the corresponding line laser.

[0037] The reconstructing of three-dimensional coordinates according to the target multimodal laser coding pattern specifically includes:

[0038] The target multimodal laser coding pattern includes a unidirectional phase-shift fringe pattern sequence and a Gray code.

[0039] A phase-mapping three-dimensional lookup table is obtained during calibration.

[0040] The phase-shifted fringe pattern sequence is solved by using an N-step phase shift method, and then the Gray code is used for decoding to determine the order of the folded phase and obtain the absolute phase.

[0041] The mapping coefficient corresponding to each image point is searched from the phase-mapping three-dimensional lookup table.

[0042] The reconstructed three-dimensional coordinates of each image point are determined according to the absolute phase and the mapping coefficient.

[0043] The step of determining the reconstructed three-dimensional coordinates of each image point according to the absolute phase and the mapping coefficient specifically includes:

[0044] according to Determine the X-axis coordinate of the reconstructed 3D coordinates of each image point, where is the X-axis coordinate, N is the polynomial order, n is a certain order, is the polynomial mapping coefficient of the X-axis, For phase.

[0045] according to Determine the Y-axis coordinate of the reconstructed 3D coordinates of each image point, where is the Y-axis coordinate, is the polynomial mapping coefficient of the Y axis, N is the polynomial order, n is a certain order, For phase.

[0046] according to The Z-axis coordinate of the reconstructed 3D coordinates of each image point, where is the Z-axis coordinate, is the polynomial mapping coefficient of the Z axis, N is the polynomial order, n is a certain order, For phase.

[0047] A three-dimensional reconstruction system based on a laser-polygonal reflective mirror, the system comprising:

[0048] Line laser acquisition module, used to acquire line laser.

[0049] The multi-modal laser coding pattern output module is used to change the offset angle of the line laser by synchronously controlling the laser power and the rotation angle of the multi-faceted reflective mirror, and output a multi-modal laser coding pattern.

[0050] The signal compensation amount determination module is used to determine the signal compensation amount according to the nonlinear relationship between the imaging end space coordinates and the offset angle of the line laser and the coordinate relationship between the initial reflection surface and the rotating reflection surface.

[0051] The target multimodal laser coding pattern output module is configured to compensate the multimodal laser coding pattern according to the signal compensation amount and output a target multimodal laser coding pattern.

[0052] A three-dimensional coordinate reconstruction module is used to reconstruct three-dimensional coordinates according to the target multimodal laser coding pattern.

[0053] A computer-readable storage medium stores a computer program, which, when executed by a processor, causes the processor to perform the steps of the above method.

[0054] The embodiments of the present invention have the following beneficial effects:

[0055] By synchronously controlling the laser power and the rotation angle of the multi-faceted reflective mirror, the offset angle of the line laser can be flexibly adjusted, thereby generating different laser coding patterns to meet different measurement requirements. Furthermore, the continuous rotation of the multi-faceted reflective mirror rapidly generates multiple scan lines, improving the efficiency and speed of data acquisition. The generated multimodal laser coding pattern contains rich multidimensional information, facilitating more accurate reconstruction of three-dimensional coordinates. Furthermore, by considering the nonlinear relationship between the spatial coordinates of the imaging end and the offset angle of the line laser, as well as the coordinate relationship between the initial reflective surface and the rotating reflective surface, a signal compensation value can be precisely calculated to eliminate measurement deviations caused by system errors or environmental factors. The multimodal laser coding pattern is then compensated based on the signal compensation value, and the target multimodal laser coding pattern is output. Furthermore, by processing the target multimodal laser coding pattern, accurate three-dimensional coordinate data can be generated, enabling three-dimensional visualization of the measured object, improving measurement accuracy, and enhancing measurement robustness and universality. The reconstructed three-dimensional coordinate data has broad application prospects in a variety of fields, such as industrial automation, robotic navigation, 3D printing, and medical imaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0057] in:

[0058] Figure 1A schematic flow chart of an embodiment of a three-dimensional reconstruction method based on laser-polygonal reflecting mirror provided by the present invention;

[0059] Figure 2 A schematic structural diagram of an embodiment of a laser-polygonal reflective mirror module provided by the present invention;

[0060] Figure 3 A schematic diagram of an embodiment of laser reflection by a multi-faceted rotating mirror provided by the present invention;

[0061] Figure 4 A schematic diagram of another embodiment of the multi-faceted rotating mirror provided by the present invention for laser reflection;

[0062] Figure 5 A plane rectangular coordinate diagram of an embodiment of a four-sided reflective rotating mirror provided by the present invention located in a plane rectangular coordinate system;

[0063] Figure 6 A schematic flow chart of another embodiment of the laser-polygonal rotating mirror-based three-dimensional reconstruction method provided by the present invention;

[0064] Figure 7 A schematic diagram of an embodiment of a multi-modal laser coding pattern offset before compensation provided by the present invention;

[0065] Figure 8 A schematic diagram of an embodiment of the planar light intensity spatial distribution of a target multimodal laser coding pattern before and after compensation provided by the present invention;

[0066] Figure 9 A schematic diagram of another embodiment of the multimodal laser coding pattern offset before compensation provided by the present invention;

[0067] Figure 10 A schematic diagram of another embodiment of the planar light intensity spatial distribution of the target multimodal laser coding pattern before and after compensation provided by the present invention;

[0068] Figure 11 A schematic structural diagram of an embodiment of a laser-polygonal rotating mirror-based three-dimensional reconstruction system provided by the present invention;

[0069] Figure 12 This is a structural diagram of an embodiment of the storage medium provided by the present invention. DETAILED DESCRIPTION

[0070] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0071] like Figure 1 As shown, Figure 1 A schematic flow chart of an embodiment of a three-dimensional reconstruction method based on a laser-polygonal rotating mirror provided by the present invention. A three-dimensional reconstruction method based on a laser-polygonal rotating mirror, the method comprising:

[0072] S101: Collect line laser.

[0073] For example, referring to Figure 2 , Figure 2 This is a schematic structural diagram of an embodiment of the laser-polygonal reflective mirror module provided by the present invention. The laser-polygonal reflective mirror is composed of a laser emitter 1 (blue light, wavelength 450nm), a linear laser beam expansion lens group 2, a polygonal reflective mirror 3 and a control circuit 4. Among them, the linear laser beam expansion lens group 2 includes a Powell prism. The laser emitter 1 emits a point laser, which is expanded by a Powell prism and projected onto the polygonal reflective mirror 3. The polygonal reflective mirror 3 includes a mirror motor 31. The mirror motor 31 deflects at high speed according to the input timing analog voltage signal, and quickly reflects the line laser into the scene to form a coded pattern. By precisely controlling the input signal waveforms of the laser emitter 1 and the polygonal reflective mirror 3 through the control circuit 4, the projection of different coded patterns can be achieved. For each coded pattern, the control circuit 4 synchronously triggers the camera to capture the image, thereby realizing multi-modal high-speed synchronous projection and acquisition integration.

[0074] S102: The offset angle of the line laser is changed by synchronously controlling the laser power and the rotation angle of the multi-faceted reflective mirror to output a multi-modal laser coding pattern.

[0075] For example, the present invention designs a multi-faceted reflective mirror 3 with N-side coatings that can reflect. The mirror motor 31 rotates 360 degrees during operation, avoiding the back-and-forth vibration of the multi-faceted reflective mirror 3. It scans N times per revolution, and the scanning speed is increased by N times compared to the original speed. Figure 3 and Figure 4 As shown, Figure 3 This is a schematic diagram of an embodiment of laser reflection performed by a multi-faceted rotating mirror provided by the present invention. Figure 4This is a schematic diagram of another embodiment of the multi-faceted reflective mirror provided by the present invention for laser reflection. The multi-faceted reflective mirror 3 includes four reflective mirrors. The laser emitter 1 and the rotation axis of the multi-faceted reflective mirror 3 are at different horizontal positions. The multi-faceted reflective mirror 3 rotates counterclockwise at a certain speed. The laser emitter 1 emits a line laser, which is reflected by a certain surface of the multi-faceted reflective mirror 3. The emitted light sweeps across the surface to be measured as the reflector rotates. By synchronously controlling the laser power and the multi-faceted reflective mirror 3, the field of view angle is achieved. The actual effective scanning range. One rotation of the rotating mirror motor 31 can achieve four projections. Currently, small hollow cup brushless motors have a rated speed of up to 15,000 rpm (unit: rpm) while meeting the torque requirements, resulting in a final projection frame rate of 1,000 frames per second.

[0076] S103: Determine a signal compensation amount according to a nonlinear relationship between the imaging end space coordinates and the offset angle of the line laser and a coordinate relationship between the initial reflection surface and the rotating reflection surface.

[0077] For example, referring to Figure 5 , Figure 5 The four-sided reflective rotating mirror provided by the present invention is located in a plane rectangular coordinate system according to an embodiment of the present invention. The initial angle of the four-sided reflective mirror is , Axis Angle, and the intercept is a as the initial reflection surface. Laser light source Send out a line laser incident light along the negative direction of the x-axis , incident on one point of the initial reflection surface , the reflected light of the line laser Axis positive direction of travel , hit the work surface point;

[0078] Set rotation angle Counterclockwise rotation is positive, such as Figure 5 , four-sided reflective mirror Point counterclockwise The angle acts as a rotating reflective surface, and the intersection laser incident light is at point At this time, the reflection point occurs on the incident laser line Move, the reflected light of the line laser rotates with the reflecting mirror times Angle, intersecting with the working surface ,Pass do The parallel line intersects the working surface at , it can be seen that the light projected on the object plane also undergoes The offset of is called spatial offset error.

[0079] Furthermore, the nonlinear relationship between the spatial coordinates of the imaging end and the offset angle of the line laser is determined. First, the target laser coding pattern outputted from the imaging end is assumed to be , taking the output cosine change pattern as an example, when the cosine time series signal is input to the laser, that is , because the rotation angle is a function of time, it is recorded as , is a time series, w is the rotation speed of the mirror, then the line laser expression at the input end can be written as:

[0080] ;

[0081] in, is the input end line laser intensity, w is the rotating mirror speed, is the rotation angle, is the input signal of the line laser, A is the background intensity, and B is the modulation depth.

[0082] Furthermore, it is easy to obtain the spatial coordinates of the imaging end line laser and rotation angle The nonlinear relationship is as follows:

[0083] ;

[0084] in, is the spatial coordinate of the imaging end line laser, is the rotation angle, is the spatial offset, for The horizontal coordinate of the point in space coordinates, for The horizontal coordinate of the point in space coordinates, for The horizontal coordinate of the point in the spatial coordinate system, D is the projection distance of the line laser moving along the positive direction of the longitudinal axis after being deflected by the initial reflection surface.

[0085] Obviously and If it is a nonlinear relationship, the laser coding pattern formed at the imaging end by the cosine time series signal uniformly sampled at the input end will deviate from the cosine change relationship and be deformed. This deviation is called nonlinear error.

[0086] in, is a constant, a is the intercept of the initial reflection surface in the plane rectangular coordinate system, and d is the vertical distance from the laser light source to the center of the reflective mirror. For a multi-faceted reflective mirror, , , there are both nonlinear errors and spatial offset errors.

[0087] At this time, the expression of the multimodal laser coding pattern output at the imaging end can be expressed as:

[0088] ;

[0089] in, is the light intensity of the multimodal laser coding pattern at the input end, is the input signal of the line laser, is the nonlinear relationship between the spatial coordinates of the imaging end and the offset angle of the line laser, A is the background intensity, and B is the modulation depth.

[0090] Furthermore, based on the multimodal laser coding pattern expression, in order to make the multimodal laser coding pattern output on the imaging surface the imaging end target output , then the input signal compensation expression is as follows:

[0091] .

[0092] Furthermore, the coordinate relationship between the initial reflection surface and the rotating reflection surface is determined. When the reflection mirror rotates counterclockwise After the angle, the old coordinates and the new coordinates satisfy:

[0093] ;

[0094] Among them, (x, y) is the old coordinate of the initial reflection surface, is the new coordinate of the rotated reflection surface, and When the initial reflection surface is Up, that is , where a is the intercept of the initial reflection surface in the plane rectangular coordinate system.

[0095] Furthermore, the input signal compensation expression is substituted into the coordinate relationship between the initial reflection surface and the rotation reflection surface to obtain the rotation reflection surface coordinate model. The rotation reflection surface coordinate model is as follows:

[0096] .

[0097] Furthermore, the spatial offset is determined based on the rotating reflection surface coordinate model. , confirm the point , as shown below:

[0098] ;

[0099] Where d is the vertical distance from the laser light source to the center of the reflective mirror, a is the intercept of the initial reflection surface in the plane rectangular coordinate system, for The horizontal coordinate of the point in space coordinates, is the rotation angle.

[0100] Therefore, combined Figure 3 , spatial offset As shown in the following formula:

[0101] ;

[0102] in, is the spatial offset, is the rotation angle, for The horizontal coordinate of the point in space coordinates, for The horizontal coordinate of the point in the spatial coordinate system, a is the intercept of the initial reflection surface in the plane rectangular coordinate system, and d is the vertical distance from the laser light source to the center of the reflecting mirror.

[0103] Furthermore, the spatial offset is substituted into the nonlinear relationship to determine the line laser offset, which is shown in the following formula:

[0104] ;

[0105] in, for The horizontal coordinate of the point in space coordinates, for The horizontal coordinate of the point in the spatial coordinate system, a is the intercept of the initial reflection surface in the plane rectangular coordinate system, d is the vertical distance from the laser light source to the center of the reflective mirror, and D is the projection distance of the line laser moving along the positive direction of the longitudinal axis after being deflected by the initial reflection surface. is the rotation angle.

[0106] Finally, the signal compensation amount can be obtained by substituting the line laser offset into the input signal compensation expression. The specific expression of the signal compensation amount is shown as follows:

[0107] ;

[0108] in, is the signal compensation amount, is the target output of the imaging end, is the rotation angle, a is the intercept of the initial reflection surface in the plane rectangular coordinate system, d is the vertical distance from the laser light source to the center of the reflection mirror, and D is the projection distance of the line laser moving along the positive direction of the longitudinal axis after being deflected by the initial reflection surface.

[0109] S104: Compensate the multimodal laser coding pattern according to the signal compensation amount, and output a target multimodal laser coding pattern.

[0110] Exemplarily, the multimodal laser coding pattern is compensated according to the signal compensation amount. At this time, the imaging end output is the preset target multimodal laser coding pattern. The target multimodal laser coding pattern is shown in the following formula:

[0111] ;

[0112] Where m is the number of fringe levels, is the left boundary of the laser-polygonal mirror at the imaging end, is the right boundary of the laser-polygonal mirror at the imaging end, is the coordinate of the line laser on the imaging surface, A is the background intensity, and B is the modulation depth.

[0113] It should be noted that since the signal compensation is based on the result, it has a compensation effect on both the coaxial mechanical galvanometer and the multi-faceted reflective mirror. The difference is that for the coaxial mechanical galvanometer, There is no spatial offset error in =0; for the multi-faceted mirror, Contains spatial offset error, .

[0114] S105: Reconstructing three-dimensional coordinates according to the target multimodal laser coding pattern.

[0115] Exemplarily, the laser-polyhedral reflective mirror module combines three measurement modes: line scanning of single-line laser, surface scanning of multi-line laser and Gray code, and surface scanning of phase-shifted stripes and Gray code. Therefore, the target multimodal laser coding pattern includes single-line laser, multi-line laser and Gray code, and phase-shifted stripe pattern sequence and Gray code.

[0116] Specifically, the main control module controls a laser-polygonal mirror to project a single laser line, rapidly scanning the object. The camera then captures the modulated light from the object's surface. An image processing algorithm extracts the center of the laser line captured by the camera, determining its sub-pixel coordinates in the image coordinate system. Using the intrinsic parameters obtained during camera calibration, the sub-pixel coordinates of the single laser line are converted to an image plane with a focal length of 1 in the camera coordinate system. For any image point, the image plane origin and a ray representing that image point are used to represent the image point. The spatial intersection of this ray and the single laser line plane is determined to reconstruct the 3D coordinates of that image point.

[0117] The main control module controls the laser-polyhedral reflective mirror to sequentially project multi-line lasers and Gray code target multimodal laser coding patterns to quickly scan objects. Since multiple laser lines exist simultaneously in the same plane, Gray code is used to encode the multiple laser lines, that is, each Gray code value corresponds to a line of laser. The parameters of the multi-line laser light plane are determined by the Gray code value, thereby converting the reconstruction of the multi-line laser into a single-line laser reconstruction.

[0118] The main control module controls a laser-polyhedron mirror to sequentially project a set of unidirectional phase-shifted fringe patterns and a target multimodal laser coding pattern in Gray code, rapidly scanning the object while the camera simultaneously captures the image. During calibration, a phase-mapping 3D lookup table is generated. The N-step phase shift method is used to solve the folded phase of the captured image. The folded phase level is then solved using Gray code to unfold the absolute phase. The mapping coefficient corresponding to each image point is retrieved from the calibrated lookup table. Substituting the phase and mapping coefficients into the 3D point calculation formula reconstructs the 3D coordinates.

[0119] As can be seen from the above description, the present invention, by synchronously controlling the laser power and the rotation angle of the multi-faceted reflective mirror, can flexibly adjust the offset angle of the line laser, thereby generating different laser coding patterns to meet different measurement requirements. Furthermore, the continuous rotation of the multi-faceted reflective mirror can rapidly generate multiple scan lines, improving the efficiency and speed of data acquisition. The generated multimodal laser coding pattern contains rich multidimensional information, facilitating more accurate reconstruction of three-dimensional coordinates. Furthermore, by considering the nonlinear relationship between the spatial coordinates of the imaging end and the offset angle of the line laser, as well as the coordinate relationship between the initial reflective surface and the rotating reflective surface, a signal compensation value can be accurately calculated, thereby eliminating measurement deviations caused by system errors or environmental factors. The multimodal laser coding pattern is then compensated based on the signal compensation value, and the target multimodal laser coding pattern is output. Furthermore, by processing the target multimodal laser coding pattern, accurate three-dimensional coordinate data can be generated, improving measurement accuracy, robustness, and universality. Three-dimensional visualization of the measured object is achieved, and the reconstructed three-dimensional coordinate data can be used in a variety of fields, such as industrial automation, robotic navigation, 3D printing, and medical imaging, with broad application prospects.

[0120] like Figure 6 As shown, Figure 6 A schematic flow chart of another embodiment of the laser-polygonal rotating mirror-based 3D reconstruction method provided by the present invention. A laser-polygonal rotating mirror-based 3D reconstruction method comprises:

[0121] S201: Collect line laser.

[0122] It should be noted that step S201 Figure 1 This has been discussed in detail in the implementation scenario shown and will not be repeated here.

[0123] S202: The offset angle of the line laser is changed by synchronously controlling the laser power and the rotation angle of the multi-faceted reflective mirror to output a multi-modal laser coding pattern.

[0124] For example, referring to Figure 7 , Figure 7This is a schematic diagram of an embodiment of the multimodal laser coding pattern deviation before compensation provided by the present invention. Through simulation modeling, the deformation of the multimodal laser coding pattern at the imaging end caused by the off-axis deviation and nonlinear transformation of a four-sided reflective mirror with a side length of 6mm at a working distance of D=800mm and a field of view of 40° was tested, where NE is the nonlinear error and SE is the spatial deviation error. Figure 7 It can be seen that the nonlinear error has a greater impact on the ideal cosine curve, while the spatial offset error has a smaller impact on the ideal cosine curve.

[0125] S203: Determine the nonlinear relationship between the imaging end space coordinates and the offset angle of the line laser.

[0126] For example, referring to Figure 5 , assuming that the target laser coding pattern output from the imaging end is , taking the output cosine change pattern as an example, when the cosine time series signal is input to the laser, that is , because the rotation angle is a function of time, it is recorded as , is a time series, w is the rotation speed of the mirror, then the line laser expression at the input end can be written as:

[0127] ;

[0128] in, is the input end line laser intensity, w is the rotating mirror speed, is the rotation angle, is the input signal of the line laser, A is the background intensity, and B is the modulation depth.

[0129] Furthermore, it is easy to obtain the spatial coordinates of the imaging end line laser Offset angle from line laser The nonlinear relationship is as follows:

[0130] ;

[0131] in, is the spatial coordinate of the imaging end line laser, is the rotation angle, is the spatial offset, for The horizontal coordinate of the point in space coordinates, for The horizontal coordinate of the point in space coordinates, for The horizontal coordinate of the point in the spatial coordinate system, D is the projection distance of the line laser moving along the positive direction of the longitudinal axis after being deflected by the initial reflection surface.

[0132] S204: Determine the expression of the multi-modal laser coding pattern output by the imaging end according to the nonlinear relationship.

[0133] For example, the expression of the multimodal laser coding pattern output at the imaging end can be expressed as:

[0134] ;

[0135] in, is the light intensity of the multimodal laser coding pattern at the input end, is the input signal of the line laser, is the nonlinear relationship between the spatial coordinates of the imaging end and the offset angle of the line laser, A is the background intensity, and B is the modulation depth.

[0136] S205: Determine an input-end signal compensation expression based on a relationship between the multimodal laser coding pattern expression and the imaging-end target output.

[0137] For example, based on the multimodal laser coding pattern expression, the multimodal laser coding pattern outputted on the imaging surface is the imaging end target output , then the input signal compensation expression is as follows:

[0138] .

[0139] S206: Determine the coordinate relationship between the initial reflection surface and the rotating reflection surface.

[0140] For example, when the reflective mirror rotates counterclockwise After the angle, the old coordinates and the new coordinates satisfy:

[0141] ;

[0142] Among them, (x, y) is the old coordinate of the initial reflection surface, is the new coordinate of the rotated reflection surface, and When the initial reflection surface is Up, that is , where a is the intercept of the initial reflection surface in the plane rectangular coordinate system.

[0143] S207: Based on the coordinate relationship between the initial reflection surface and the rotation reflection surface, a coordinate model of the rotation reflection surface is determined according to an input end signal compensation expression.

[0144] For example, the input end signal compensation expression is substituted into the coordinate relationship between the initial reflection surface and the rotation reflection surface to obtain the rotation reflection surface coordinate model. The rotation reflection surface coordinate model is as follows:

[0145] .

[0146] S208: Determine the spatial offset according to the rotating reflection surface coordinate model.

[0147] For example, let the ordinate in the rotating reflection surface coordinate model be , confirm the point , as shown below:

[0148] ;

[0149] Where d is the vertical distance from the laser light source to the center of the reflective mirror, a is the intercept of the initial reflection surface in the plane rectangular coordinate system, for The horizontal coordinate of the point in space coordinates, is the rotation angle.

[0150] Therefore, combined Figure 3 , spatial offset As shown in the following formula:

[0151] ;

[0152] in, is the spatial offset, is the rotation angle, for The horizontal coordinate of the point in space coordinates, for The horizontal coordinate of the point in the spatial coordinate system, a is the intercept of the initial reflection surface in the plane rectangular coordinate system, and d is the vertical distance from the laser light source to the center of the reflecting mirror.

[0153] S209: Based on the nonlinear relationship, determine the line laser offset according to the spatial offset.

[0154] For example, the spatial offset is substituted into the nonlinear relationship to determine the line laser offset, which is shown in the following formula:

[0155] ;

[0156] in, for The horizontal coordinate of the point in space coordinates, for The horizontal coordinate of the point in the spatial coordinate system, a is the intercept of the initial reflection surface in the plane rectangular coordinate system, d is the vertical distance from the laser light source to the center of the reflective mirror, and D is the projection distance of the line laser moving along the positive direction of the longitudinal axis after being deflected by the initial reflection surface. is the rotation angle.

[0157] S210: Substitute the line laser offset into the input end signal compensation expression to determine the signal compensation amount.

[0158] For example, the signal compensation amount can be obtained by substituting the line laser offset into the input end signal compensation expression. The specific expression of the signal compensation amount is shown as follows:

[0159] ;

[0160] in, is the signal compensation amount, is the target output of the imaging end, is the rotation angle, a is the intercept of the initial reflection surface in the plane rectangular coordinate system, d is the vertical distance from the laser light source to the center of the reflection mirror, and D is the projection distance of the line laser moving along the positive direction of the longitudinal axis after being deflected by the initial reflection surface.

[0161] S211: Compensate the multimodal laser coding pattern according to the signal compensation amount, and output a target multimodal laser coding pattern.

[0162] For example, based on the compensation formula, the deformation of the laser-polygonal reflective mirror structure can be corrected. Taking a 4-sided reflector with a side length of 6mm as an example, the simulation is performed at a working distance of 800mm and a field of view of 40°. The compensation results are as follows: Figure 8 As shown, Figure 8 This is a schematic diagram of an embodiment of the planar light intensity spatial distribution of the target multimodal laser coding pattern before and after compensation provided by the present invention. Figure 8 It can be seen that the curve of the target multimodal laser coding pattern after compensation completely coincides with the ideal cosine curve.

[0163] It should be noted that the target multimodal laser coding pattern proposed in the present invention can be a cosine, square wave or other function, and is not specifically limited here. Figure 9 and Figure 10 As shown, Figure 9 This is a schematic diagram of another embodiment of the multimodal laser coding pattern offset before compensation provided by the present invention. Figure 10 This is a schematic diagram of another embodiment of the planar light intensity spatial distribution of the target multimodal laser coding pattern before and after compensation provided by the present invention. Figure 9 and Figure 10The multimodal laser coding pattern in is a square wave distribution. When compensating, first determine the nonlinear relationship between the spatial coordinates of the imaging end and the offset angle of the line laser. Determine the expression of the multimodal laser coding pattern output by the imaging end based on the nonlinear relationship. Determine the input end signal compensation expression based on the relationship between the multimodal laser coding pattern expression and the target output of the imaging end. Determine the coordinate relationship between the initial reflection surface and the rotating reflection surface. Based on the coordinate relationship between the initial reflection surface and the rotating reflection surface, determine the rotating reflection surface coordinate model according to the input end signal compensation expression. Determine the spatial offset according to the rotating reflection surface coordinate model. Based on the nonlinear relationship, determine the line laser offset according to the spatial offset. Substitute the line laser offset into the input end signal compensation expression to determine the signal compensation. Further, compensate the multimodal laser coding pattern according to the signal compensation amount, and output the target multimodal laser coding pattern. The compensation result of the square wave distribution is as follows. Figure 10 As shown in FIG, the light intensity curve at the imaging end after compensation completely coincides with the ideal intensity curve.

[0164] When the working distance of the 4-mirror mirror with a side length of 6 mm is D=800 mm and the field of view is 40°, the maximum and standard deviation of the spatial offset error SE and the nonlinear error NE on the final image grayscale are shown in Table 1. Table 1 shows the influence of the spatial offset error and the nonlinear error on the final image grayscale:

[0165] Table 1 shows the influence of spatial offset error and nonlinear error on the final imaging grayscale

[0166]

[0167] S212: Reconstructing three-dimensional coordinates according to the target multimodal laser coding pattern.

[0168] Exemplarily, the laser-polyhedral reflective mirror module combines three measurement modes: line scanning of single-line laser, surface scanning of multi-line laser and Gray code, and surface scanning of phase-shifted stripes and Gray code. Therefore, the target multimodal laser coding pattern includes single-line laser, multi-line laser and Gray code, and phase-shifted stripe pattern sequence and Gray code.

[0169] Specifically, the target multimodal laser coding pattern includes a single-line laser; an image processing algorithm is used to extract the center of the light strip of the single-line laser, and determine the sub-pixel precision coordinates of the single-line laser in the image coordinate system; the camera intrinsic parameters are used to convert the sub-pixel precision coordinates to the image plane in the camera coordinate system; for any image point on the image plane, the ray from the origin of the image plane to the image point is determined; and the three-dimensional coordinates of the current image point are reconstructed by determining the spatial intersection of the ray and the single-line laser light plane.

[0170] The target multimodal laser coding pattern includes multi-line laser and Gray code; the multi-line laser is encoded using Gray code to determine the light plane parameters of the multi-line laser; the light plane equation of the multi-line laser is determined based on the light plane parameters of the multi-line laser; the image processing algorithm is used to extract the center of the light strip of each line laser in the multi-line laser, and the sub-pixel precision coordinates of the multi-line laser in the image coordinate system are determined; the camera intrinsic parameters are used to convert the sub-pixel precision coordinates to the image plane in the camera coordinate system; for any image point on the image plane, the ray from the image plane origin to the image point is determined; and the three-dimensional coordinates of the current image point are reconstructed by determining the spatial intersection of the ray of the image point and the light plane equation of the corresponding line laser.

[0171] The target multimodal laser coding pattern includes a unidirectional phase-shifted fringe pattern sequence and a Gray code. During calibration, a phase-mapping three-dimensional lookup table is obtained. The phase-shifted fringe pattern sequence is solved using the N-step phase shift method, and then decoded using the Gray code to determine the order of the folded phase and obtain the absolute phase. The mapping coefficient corresponding to each image point is queried from the phase-mapping three-dimensional lookup table. Based on the absolute phase and mapping coefficient, the reconstructed three-dimensional coordinates of each image point are determined. The X-axis coordinate of the reconstructed three-dimensional coordinates of each image point is determined according to the following formula:

[0172] ;

[0173] in, is the X-axis coordinate, N is the polynomial order, n is a certain order, is the polynomial mapping coefficient of the X-axis, For phase.

[0174] The Y-axis coordinate of the reconstructed 3D coordinates of each image point is determined according to the following formula:

[0175] ;

[0176] in, is the Y-axis coordinate, is the polynomial mapping coefficient of the Y axis, N is the polynomial order, n is a certain order, is the phase;

[0177] The Z-axis coordinate of the reconstructed 3D coordinates of each image point is determined according to the following formula:

[0178] ;

[0179] in, is the Z-axis coordinate, is the polynomial mapping coefficient of the Z axis, N is the polynomial order, n is a certain order, For phase.

[0180] From the above description, it can be seen that the present invention can accurately calculate the signal compensation amount by considering the nonlinear relationship between the spatial coordinates of the imaging end and the offset angle of the line laser, as well as the coordinate relationship between the initial reflection surface and the rotating reflection surface, thereby eliminating the measurement deviation caused by system errors or environmental factors. The multimodal laser coding pattern is compensated according to the signal compensation amount, and the target multimodal laser coding pattern is output. In addition, the determination of the signal compensation amount improves the accuracy of the measurement data and provides a reliable foundation for subsequent three-dimensional reconstruction. During the three-dimensional reconstruction process, for local reflective or black areas, surface scanning of the line laser or surface scanning can be used for supplementary scanning to further improve the measurement accuracy.

[0181] like Figure 11 As shown, Figure 11 A schematic diagram of the structure of an embodiment of a laser-polygonal rotating mirror-based 3D reconstruction system provided by the present invention. A laser-polygonal rotating mirror-based 3D reconstruction system 10 includes:

[0182] The line laser acquisition module 11 is used to acquire line lasers.

[0183] The multi-modal laser coding pattern output module 12 is used to change the offset angle of the line laser by synchronously controlling the laser power and the rotation angle of the multi-faceted reflective mirror, and output a multi-modal laser coding pattern.

[0184] The signal compensation amount determination module 13 is used to determine the signal compensation amount according to the nonlinear relationship between the imaging end space coordinates and the offset angle of the line laser and the coordinate relationship between the initial reflection surface and the rotating reflection surface.

[0185] The target multimodal laser coding pattern output module 14 is configured to compensate the multimodal laser coding pattern according to the signal compensation amount and output the target multimodal laser coding pattern.

[0186] The three-dimensional coordinate reconstruction module 15 is used to reconstruct the three-dimensional coordinates according to the target multi-modal laser coding pattern.

[0187] Exemplarily, in the line laser acquisition module 11, a line laser is acquired. Furthermore, in the multimodal laser coding pattern output module 12, the offset angle of the line laser is changed by synchronously controlling the laser power and the rotation angle of the multi-faceted reflective mirror to output a multimodal laser coding pattern. Furthermore, in the signal compensation determination module 13, a nonlinear relationship between the spatial coordinates of the imaging end and the offset angle of the line laser is determined; an expression for the multimodal laser coding pattern output by the imaging end is determined based on the nonlinear relationship; an input-end signal compensation expression is determined based on the relationship between the multimodal laser coding pattern expression and the target output of the imaging end; a coordinate relationship between the initial reflective surface and the rotating reflective surface is determined; a rotating reflective surface coordinate model is determined based on the coordinate relationship between the initial reflective surface and the rotating reflective surface based on the input-end signal compensation expression; a spatial offset is determined based on the rotating reflective surface coordinate model; a line laser offset is determined based on the nonlinear relationship and the spatial offset; and the line laser offset is substituted into the input-end signal compensation expression to determine the signal compensation. Furthermore, in the target multimodal laser coding pattern output module 14, the multimodal laser coding pattern is compensated based on the signal compensation amount, and the target multimodal laser coding pattern is output. Finally, the three-dimensional coordinates are reconstructed in the three-dimensional coordinate reconstruction module 15. Specifically, the target multimodal laser coding pattern includes a single-line laser; an image processing algorithm is used to extract the center of the light strip of the single-line laser, and the sub-pixel precision coordinates of the single-line laser in the image coordinate system are determined; the camera intrinsic parameters are used to convert the sub-pixel precision coordinates to the image plane in the camera coordinate system; for any image point on the image plane, the ray from the image plane origin to the image point is determined; and the three-dimensional coordinates of the current image point are reconstructed by determining the spatial intersection of the ray and the single-line laser light plane.

[0188] The target multimodal laser coding pattern includes multi-line laser and Gray code; the multi-line laser is encoded using Gray code to determine the light plane parameters of the multi-line laser; the light plane equation of the multi-line laser is determined based on the light plane parameters of the multi-line laser; the image processing algorithm is used to extract the center of the light strip of each line laser in the multi-line laser, and the sub-pixel precision coordinates of the multi-line laser in the image coordinate system are determined; the camera intrinsic parameters are used to convert the sub-pixel precision coordinates to the image plane in the camera coordinate system; for any image point on the image plane, the ray from the image plane origin to the image point is determined; and the three-dimensional coordinates of the current image point are reconstructed by determining the spatial intersection of the ray of the image point and the light plane equation of the corresponding line laser.

[0189] The target multimodal laser coding pattern includes a unidirectional phase-shifted fringe pattern sequence and a Gray code. A phase-mapping three-dimensional lookup table is obtained during calibration. The phase-shifted fringe pattern sequence is solved using an N-step phase shift method, and then decoded using Gray code to determine the order of the folded phase and obtain the absolute phase. The mapping coefficient corresponding to each image point is queried from the phase-mapping three-dimensional lookup table. The reconstructed three-dimensional coordinates of each image point are determined based on the absolute phase and mapping coefficient.

[0190] like Figure 12 As shown, Figure 12 The storage medium 20 stores at least one computer program 21, which is executed by a processor to implement the following. Figure 1 and Figure 6 In one embodiment, the storage medium 30 may be a memory chip, a hard disk, a mobile hard disk, a USB flash drive, an optical disk, or other readable and writable storage tools, or a server.

[0191] The foregoing description of specific embodiments of the present disclosure is intended to illustrate a method for performing a multi-tasking process. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in an order different from that described in the embodiments and still achieve the desired results. Furthermore, the processes depicted in the accompanying drawings do not necessarily require the specific order shown or the sequential order shown to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0192] The various embodiments in this specification are described in a progressive manner. Similar portions between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from the other embodiments. In particular, the device, apparatus, and non-volatile computer-readable storage medium embodiments are generally similar to the method embodiments, so their descriptions are relatively simplified. For relevant details, refer to the descriptions of the method embodiments.

[0193] The apparatus, device, non-volatile computer-readable storage medium and method provided in the embodiments of this specification correspond to each other. Therefore, the apparatus, device, and non-volatile computer storage medium also have similar beneficial technical effects as the corresponding method. Since the beneficial technical effects of the method have been described in detail above, the beneficial technical effects of the corresponding apparatus, device, and non-volatile computer storage medium will not be repeated here.

[0194] The systems, devices, modules, or units described in the above embodiments may be implemented by computer chips or entities, or by products having certain functions. A typical implementation device is a computer. Specifically, the computer may be, for example, a personal computer, a laptop computer, a cellular phone, a camera phone, a smartphone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or a combination of any of these devices.

[0195] For the convenience of description, when describing the above device, various units are divided into functions and described separately. Of course, when implementing this specification, the functions of each unit can be implemented in the same one or more software and / or hardware. It should be understood by those skilled in the art that this specification embodiment can be provided as a method, system, or computer program product. Therefore, this specification embodiment can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, this specification embodiment can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0196] This specification is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of this specification. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0197] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0198] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0199] In a typical configuration, a computing device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory.

[0200] Memory may include non-permanent storage in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. Memory is an example of a computer-readable medium.

[0201] Computer-readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. The information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include transitory media such as modulated data signals and carrier waves.

[0202] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0203] This specification may be described in the general context of computer-executable instructions, such as program modules, executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, and the like that perform specific tasks or implement specific abstract data types. This specification may also be practiced in distributed computing environments where tasks are performed by remote processing devices connected through a communications network. In a distributed computing environment, program modules may be located in both local and remote computer storage media, including storage devices.

[0204] The various embodiments in this specification are described in a progressive manner. Similar parts between the various embodiments can be referred to in conjunction with each other. Each embodiment focuses on the differences between the other embodiments. In particular, the system embodiments are generally similar to the method embodiments, so the description is relatively simple. For relevant parts, refer to the description of the method embodiments.

[0205] The above disclosure is merely a preferred embodiment of the present invention and certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A three-dimensional reconstruction method based on laser-polygonal reflective mirror, characterized in that: The method comprises: Acquisition line laser; The offset angle of the line laser is changed by synchronously controlling the laser power and the rotation angle of the multi-faceted reflective mirror to output a multi-modal laser coding pattern; The signal compensation amount is determined according to the nonlinear relationship between the imaging end space coordinates and the offset angle of the line laser and the coordinate relationship between the initial reflection surface and the rotating reflection surface. The signal compensation amount is determined according to Determine, among which, is the signal compensation amount, is the target output of the imaging end, is the rotation angle, a is the intercept of the initial reflection surface in the plane rectangular coordinate system, d is the vertical distance from the laser light source to the center of the reflection mirror, and D is the projection distance of the line laser moving along the positive direction of the longitudinal axis after being deflected by the initial reflection surface; Compensating the multimodal laser coding pattern according to the signal compensation amount, and outputting a target multimodal laser coding pattern; The three-dimensional coordinates are reconstructed according to the target multimodal laser coding pattern.

2. The three-dimensional reconstruction method based on laser-polygonal mirror according to claim 1, characterized in that: The signal compensation amount is determined according to the nonlinear relationship between the imaging end space coordinates and the offset angle of the line laser and the coordinate relationship between the initial reflection surface and the rotating reflection surface, specifically including: Determining a nonlinear relationship between the spatial coordinates of the imaging end and the offset angle of the line laser; Determine the multi-modal laser coding pattern expression output by the imaging end according to the nonlinear relationship; Determining an input-end signal compensation expression based on a relationship between the multimodal laser coding pattern expression and the imaging-end target output; Determine the coordinate relationship between the initial reflection surface and the rotating reflection surface; Based on the coordinate relationship between the initial reflection surface and the rotation reflection surface, determining the rotation reflection surface coordinate model according to the input end signal compensation expression; determining a spatial offset according to the rotating reflective surface coordinate model; Based on the nonlinear relationship, determining the line laser offset according to the spatial offset; The line laser offset is substituted into the input end signal compensation expression to determine the signal compensation amount.

3. The three-dimensional reconstruction method based on laser-polygonal mirror according to claim 2, characterized in that: The step of determining the input end signal compensation expression based on the relationship between the multimodal laser coding pattern expression and the imaging end target output specifically includes: according to Determine the input signal compensation expression, where is the signal compensation amount, is the target output of the imaging end, is the nonlinear relationship between the spatial coordinates of the imaging end and the offset angle of the line laser, w is the rotation speed of the mirror, is the rotation angle.

4. The three-dimensional reconstruction method based on laser-polygonal mirror according to claim 2, characterized in that: The reconstructing of three-dimensional coordinates according to the target multimodal laser coding pattern specifically includes: The target multimodal laser coding pattern includes a single line of laser; An image processing algorithm is used to extract the center of the light stripe of the single-line laser and determine the sub-pixel precision coordinates of the single-line laser in an image coordinate system; The sub-pixel precision coordinates are converted to an image plane in a camera coordinate system using camera intrinsic parameters; For any image point on the image plane, determining a ray from the image plane origin to the image point; The three-dimensional coordinates of the current image point are reconstructed by determining the spatial intersection point of the ray and the single-line laser light plane.

5. The three-dimensional reconstruction method based on laser-polygonal mirror according to claim 2, characterized in that: The reconstructing of three-dimensional coordinates according to the target multimodal laser coding pattern specifically includes: The target multimodal laser coding pattern includes multi-line laser and Gray code; Encoding the multi-line laser using the Gray code to determine light plane parameters of the multi-line laser; determining a light plane equation of the multi-line laser according to light plane parameters of the multi-line laser; Using an image processing algorithm to extract the center of each line of laser light in the multi-line laser, and determining the sub-pixel precision coordinates of the multi-line laser in an image coordinate system; The sub-pixel precision coordinates are converted to an image plane in a camera coordinate system using camera intrinsic parameters; For any image point on the image plane, determining a ray from the image plane origin to the image point; The three-dimensional coordinates of the current image point are reconstructed by determining the spatial intersection point of the ray of the image point and the light plane equation of the corresponding line laser.

6. The three-dimensional reconstruction method based on laser-polygonal mirror according to claim 2, characterized in that: The reconstructing of three-dimensional coordinates according to the target multimodal laser coding pattern specifically includes: The target multimodal laser coding pattern includes a unidirectional phase-shifted fringe pattern sequence and a Gray code; A phase-mapping three-dimensional lookup table is obtained during calibration; Using an N-step phase shift method to solve the folding phase of the phase-shifted fringe pattern sequence, and then decoding it using the Gray code to determine the order of the folding phase and obtain the absolute phase; Querying the mapping coefficient corresponding to each image point from the phase-mapping three-dimensional lookup table; The reconstructed three-dimensional coordinates of each image point are determined according to the absolute phase and the mapping coefficient.

7. The three-dimensional reconstruction method based on laser-polygonal mirror according to claim 6, characterized in that: The determining of the reconstructed three-dimensional coordinates of each image point according to the absolute phase and the mapping coefficient specifically includes: according to Determine the X-axis coordinate of the reconstructed 3D coordinates of each image point, where is the X-axis coordinate, N is the polynomial order, n is a certain order, is the polynomial mapping coefficient of the X-axis, is the phase; according to Determine the Y-axis coordinate of the reconstructed 3D coordinates of each image point, where is the Y-axis coordinate, is the polynomial mapping coefficient of the Y axis, N is the polynomial order, n is a certain order, is the phase; according to The Z-axis coordinate of the reconstructed 3D coordinates of each image point, where is the Z-axis coordinate, is the polynomial mapping coefficient of the Z axis, N is the polynomial order, n is a certain order, For phase.

8. A three-dimensional reconstruction system based on laser-polygonal reflective mirror, characterized in that: The system comprises: Line laser acquisition module, used to acquire line laser; A multi-modal laser coding pattern output module is used to change the offset angle of the line laser by synchronously controlling the laser power and the rotation angle of the multi-faceted reflective mirror to output a multi-modal laser coding pattern; The signal compensation amount determination module is used to determine the signal compensation amount according to the nonlinear relationship between the imaging end space coordinates and the offset angle of the line laser and the coordinate relationship between the initial reflection surface and the rotating reflection surface. Determine, among which, is the signal compensation amount, is the target output of the imaging end, is the rotation angle, a is the intercept of the initial reflection surface in the plane rectangular coordinate system, d is the vertical distance from the laser light source to the center of the reflection mirror, and D is the projection distance of the line laser moving along the positive direction of the longitudinal axis after being deflected by the initial reflection surface; a target multimodal laser coding pattern output module, configured to compensate the multimodal laser coding pattern according to the signal compensation amount and output a target multimodal laser coding pattern; A three-dimensional coordinate reconstruction module is used to reconstruct three-dimensional coordinates according to the target multi-modal laser coding pattern.

9. A computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the processor is caused to perform the steps of the method according to any one of claims 1 to 7.

Images