MEMS structured light high-precision three-dimensional measurement method, device, equipment and medium
By establishing the correlation between phase, angle, and ray mapping model, the projection characteristics of MEMS structured light system are accurately characterized, solving the problem of low three-dimensional measurement accuracy of MEMS structured light system and realizing high-precision three-dimensional measurement.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-25
- Publication Date
- 2026-03-27
AI Technical Summary
When performing 3D measurements based on MEMS structured light systems, the accuracy is not high. This is mainly because the nonlinear angular response of the MEMS mirror and the fast and slow axis coupling effect lead to complex projection geometry, making it difficult to accurately characterize the projection characteristics.
By establishing the correlation between phase, angle, and ray mapping model, the projection characteristics of the projection device are accurately characterized. Orthogonal bidirectional fringe pattern projection and phase demodulation are adopted, combined with least squares fitting and iterative optimization, to achieve high-precision three-dimensional measurement.
It improves the global scale consistency and measurement accuracy of 3D measurement, and solves the problem of insufficient accuracy of MEMS structured light system in 3D measurement.
Smart Images
Figure CN121739922A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of optical three-dimensional digital imaging, and in particular to MEMS structured light high-precision three-dimensional measurement methods, devices, equipment and media. Background Technology
[0002] In applications such as industrial inspection, robot positioning, and precision manufacturing, 3D measurement of objects is required. Typically, the 3D shape is reconstructed based on structured fringe patterns projected onto the object's surface. The structured light projection device used is a 2D MEMS projection device based on laser scanning. This device achieves rapid angular scanning of the laser beam through a dual-axis galvanometer, thereby generating a programmable fringe pattern. Methods such as planar calibration or phase-height mapping are employed, which usually rely on high-precision, multi-pose calibration plates. The nonlinear angular response of the MEMS galvanometer and the fast-slow axis coupling effect complicate its projection geometry, making it difficult to accurately characterize the projection characteristics of the MEMS projection device. This leads to proportional errors and geometric distortions in the 3D measurement results. Therefore, existing technologies suffer from low accuracy in 3D measurement based on MEMS structured light systems. Summary of the Invention
[0003] This application provides a method, apparatus, device, and medium for high-precision three-dimensional measurement using MEMS structured light, which can solve the technical problem of low accuracy when performing three-dimensional measurements based on MEMS structured light systems.
[0004] In a first aspect, embodiments of this application provide a high-precision three-dimensional measurement method for MEMS structured light. This method is applied to a controller in a MEMS structured light high-precision three-dimensional measurement system. The MEMS structured light high-precision three-dimensional measurement system includes a projection device and an imaging device. The controller establishes a communication connection with both the projection device and the imaging device. First, the projection device is controlled to project a bi-directional orthogonal fringe pattern onto the surface of the target to be measured. Then, the imaging device is controlled to acquire a surface fringe image of the target to be measured. The MEMS structured light high-precision three-dimensional measurement method includes:
[0005] In response to a three-dimensional measurement command for the target under test, a first orthogonal phase distribution information about the target under test is determined based on a surface stripe image acquired from the imaging device.
[0006] Determine the equation of the first spatial line of the fitted projection ray under the preset projection phase in the coordinate system of the imaging device;
[0007] The first spatial line equation is transformed to obtain the second spatial line equation of the fitted projection ray in the projection device coordinate system. The projection device coordinate system is established based on mutually orthogonal unit vectors, which are extracted from the first spatial line equation.
[0008] Based on the correspondence between the second spatial straight line equation and the preset projection phase, a mapping model is determined that maps the offset angle to the projection phase. The offset angle refers to the angle by which the second spatial straight line equation deviates from the unit vector in the coordinate system of the projection device.
[0009] Based on the mapping model, the phase in the first orthogonal phase distribution information is mapped to obtain the first offset angle of the projected ray of the target under test in the coordinate system of the projection device.
[0010] Based on the first offset angle, the point cloud of the target under test involved on the projected ray is determined, and the three-dimensional coordinates of the target under test in space are obtained.
[0011] In some embodiments, determining the mapping model that maps the offset angle to the projection phase based on the correspondence between the second spatial straight line equation and the preset projection phase includes:
[0012] Determine the offset angle of the second spatial straight line equation relative to the unit vector in the coordinate system of the projection device;
[0013] Based on the correspondence between the offset angle and the preset projection phase, an initial mapping model is established that maps the offset angle to the projection phase.
[0014] Obtain the second orthogonal phase distribution information of the preset calibration material used for parameter optimization;
[0015] Based on the second orthogonal phase distribution information, the initial mapping model is iteratively optimized to obtain the mapping model with optimized parameters.
[0016] In some embodiments, the mapping model parameters are mapping parameters between the deflection angle and the projection phase. When iteratively optimizing the mapping model, the imaging parameters of the imaging device and the coordinate system of the projection device are also optimized. The imaging parameters include intrinsic parameters.
[0017] In some embodiments, the iterative optimization of the initial mapping model based on the second orthogonal phase distribution information to obtain a mapping model with optimized mapping model parameters includes:
[0018] The initial offset angle of the preset calibration object is obtained by mapping the phase in the second orthogonal phase distribution information through the initial mapping model.
[0019] Based on the initial offset angle, the preset calibration object is reconstructed in three dimensions to obtain a three-dimensional fitted point cloud of the preset calibration object;
[0020] Based on the 3D fitted point cloud of the preset calibration object, the mapping model parameters are iteratively optimized with the goal of minimizing the fitting error, and the optimized mapping model is obtained.
[0021] In some embodiments, the preset calibration objects include a standard sphere and a standard plane; correspondingly, the fitting error includes the fitting error of the distance between the sphere's center and the target surface. radius fitting error and the fitting error of the standard plane The fitting error is , as well as The sum of, among which,
[0022]
[0023] w1, w2, and w3 are the weights. For the first The coordinates of the center of each sphere With the The coordinates of the center of each sphere The distance between them For the first The standard ball and the first The true center-to-center distance between standard spheres To fit the standard sphere, the three-dimensional points on the surface of the fitted sphere are obtained. For the first The true radius of a standard sphere To fit the radius of the sphere, The first type of three-dimensional point is obtained by the intersection of the optical center ray of the imaging device and the standard plane. The second type of three-dimensional point is obtained by the intersection of the projected ray and the standard plane. This represents the distance between the first type of 3D point and the second type of 3D point.
[0024] In some embodiments, determining the point cloud of the target under test on the projected ray based on the first offset angle, and obtaining the three-dimensional coordinates of the target under test in space, includes:
[0025] Based on the first offset angle, the equation of the third spatial line of the projection ray when projecting onto the target is determined in the coordinate system of the projection device.
[0026] The third spatial line equation is transformed to obtain the fourth spatial line equation of the projection ray when the target is projected in the coordinate system of the imaging device. The fourth spatial line equation represents the projection ray when the target is projected in the view of the imaging device.
[0027] The optical center ray of the imaging device is obtained by calculation based on the fourth spatial linear equation and the imaging parameters of the imaging device.
[0028] The surface point cloud of the target is determined based on the intersection point between the optical center ray of the imaging device and the projected ray when the target is projected.
[0029] The three-dimensional coordinates of the surface point cloud of the target to be tested are used as the three-dimensional coordinates of the target to be tested in space.
[0030] In some embodiments, before performing coordinate transformation on the first spatial line equation to obtain the second spatial line equation of the fitted projection ray in the projection device coordinate system, the following steps are included:
[0031] The center of the galvanometer of the projection device is obtained by fitting the intersection points of multiple first spatial line equations using the least squares method.
[0032] The scanning direction is extracted from the equation of the first spatial line to obtain a first unit vector and a second unit vector that are orthogonal to each other.
[0033] Perform a cross product operation on the first unit vector and the second unit vector to obtain a third unit vector that is orthogonal to both the first unit vector and the second unit vector;
[0034] A spatial three-dimensional coordinate system is established with the center of the galvanometer as the center of the coordinate system, and the first unit vector, the second unit vector, and the third unit vector as the coordinate axes, thus obtaining the coordinate system of the projection device.
[0035] Secondly, embodiments of this application also provide a high-precision three-dimensional measurement device for MEMS structured light. The high-precision three-dimensional measurement device is configured in the controller of a MEMS structured light high-precision three-dimensional measurement system. The MEMS structured light high-precision three-dimensional measurement system includes a projection device and an imaging device. The controller establishes a communication connection with the projection device and the imaging device. First, the projection device is controlled to project a bi-directional orthogonal fringe pattern onto the surface of the target to be measured. Then, the imaging device is controlled to acquire a surface fringe image of the target to be measured. The high-precision three-dimensional measurement device for MEMS structured light includes:
[0036] The first determining unit is configured to, in response to a three-dimensional measurement command for the target under test, determine first orthogonal phase distribution information about the target under test based on a surface stripe image acquired from the imaging device.
[0037] The second determining unit is used to determine the first spatial straight line equation of the fitted projection ray under the preset projection phase in the coordinate system of the imaging device.
[0038] The coordinate transformation unit is used to perform coordinate transformation on the first spatial line equation to obtain the second spatial line equation of the fitted projection ray in the projection device coordinate system, wherein the projection device coordinate system is established based on mutually orthogonal unit vectors, which are extracted from the first spatial line equation.
[0039] The third determining unit is used to determine a mapping model in which the offset angle and the projection phase are mapped to each other based on the correspondence between the second spatial straight line equation and the preset projection phase, wherein the offset angle refers to the angle by which the second spatial straight line equation deviates from the unit vector in the coordinate system of the projection device.
[0040] The mapping unit is used to map the phase in the first orthogonal phase distribution information based on the mapping model to obtain the first offset angle of the corresponding projection ray of the target under test in the coordinate system of the projection device.
[0041] The fourth determining unit is used to determine the point cloud of the target under test on the projected ray based on the first offset angle, and to obtain the three-dimensional coordinates of the target under test in space.
[0042] Thirdly, embodiments of this application also provide a MEMS structured light high-precision three-dimensional measurement device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the above-mentioned method.
[0043] Fourthly, embodiments of this application also provide a computer-readable medium storing a computer program, the computer program including program instructions that, when executed by a processor, can implement the above-described method.
[0044] This application provides a method, apparatus, device, and medium for high-precision three-dimensional measurement of MEMS structured light. The method includes: responding to a three-dimensional measurement command for a target under test, determining first orthogonal phase distribution information of the target under test based on a surface stripe image acquired from the imaging device; determining a first spatial straight line equation of a fitted projection ray under a preset projection phase in the coordinate system of the imaging device; performing coordinate transformation on the first spatial straight line equation to obtain a second spatial straight line equation of the fitted projection ray in the coordinate system of the projection device, wherein the coordinate system of the projection device is established based on mutually orthogonal unit vectors, which are extracted from the first spatial straight line equation; determining a mapping model that maps the offset angle to the projection phase based on the correspondence between the second spatial straight line equation and the preset projection phase, wherein the offset angle refers to the angle by which the second spatial straight line equation deviates from the unit vector in the coordinate system of the projection device; mapping the phase in the first orthogonal phase distribution information based on the mapping model to obtain a first offset angle of the corresponding projection ray of the target under test in the coordinate system of the projection device; and determining the point cloud of the target under test involved on the projection ray based on the first offset angle to obtain the three-dimensional coordinates of the target under test in space. In this application, without relying on a high-precision calibration plate, the correlation between phase and angle and ray mapping model is established, accurately characterizing the projection characteristics of the projection device, and solving the technical problem of low accuracy when performing three-dimensional measurements based on MEMS structured light systems. Attached Figure Description
[0045] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0046] Figure 1 A flowchart illustrating the high-precision three-dimensional measurement method for MEMS structured light provided in this application embodiment;
[0047] Figure 2 A schematic block diagram of a MEMS structured light high-precision three-dimensional measurement system provided in the embodiments of this application;
[0048] Figure 3 A schematic block diagram of a MEMS structured light high-precision three-dimensional measurement device provided in the embodiments of this application;
[0049] Figure 4 A schematic block diagram of the device provided in the embodiments of this application. Detailed Implementation
[0050] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0051] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.
[0052] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.
[0053] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.
[0054] Fringe projection profilometry is widely used due to its non-contact, high-resolution, and high-speed three-dimensional measurement characteristics.
[0055] Structured light systems are used in industrial inspection, robot positioning, and precision manufacturing. Traditional structured light systems typically consist of a camera and a projector, reconstructing the three-dimensional shape by projecting structured stripe patterns onto the surface of an object and analyzing their deformation. Most of these systems use digital micromirrors as the projection component, but are limited by their large size, limited response speed, and insufficient projection depth of field, making it difficult to achieve high-precision measurements in compact spaces or scenes with large depth of field.
[0056] With the development of Micro-Electro-Mechanical Systems (MEMS) technology, laser-scanning-based two-dimensional MEMS projection devices have become the next generation of structured light projection devices. This device achieves rapid angular scanning of the laser beam through dual-axis galvanometers, thereby generating programmable stripe patterns. Compared to traditional projection technologies, MEMS projection devices offer advantages such as compact structure, low power consumption, no focal length limitations, and high projection speed.
[0057] However, the nonlinear angular response and fast-slow axis coupling effect of MEMS galvanometers complicate their projection geometry, making it difficult for traditional models to accurately characterize the projection characteristics of MEMS projection devices, resulting in scaling errors and geometric distortions in the 3D reconstruction results. Existing MEMS structured light systems mostly employ methods such as planar calibration or phase-height mapping. These methods typically rely on high-precision, multi-pose calibration plates and lack accurate modeling of the MEMS scanning geometry, making it difficult to accurately characterize the projection characteristics of MEMS projection devices, thus affecting the system's calibration accuracy and 3D reconstruction accuracy. Therefore, existing technologies suffer from low accuracy when performing 3D measurements based on MEMS structured light systems.
[0058] To address the issue of low accuracy in 3D measurements using MEMS structured light systems, this application provides a method, apparatus, device, and medium for high-precision 3D measurement using MEMS structured light. The method is applied to a controller within a MEMS structured light high-precision 3D measurement system. This system includes a projection device and an imaging device. The controller establishes a communication connection with both the projection and imaging devices. First, the projection device projects a bidirectional orthogonal fringe pattern onto the surface of the target object. Then, the imaging device acquires the surface fringe image of the target object.
[0059] Figure 1 This is a schematic diagram of the process for high-precision three-dimensional measurement of MEMS structured light provided in an embodiment of this application. Figure 1 As shown, the method includes the following steps S110-S160:
[0060] S110. In response to a three-dimensional measurement command for the target under test, determine first orthogonal phase distribution information about the target under test based on the surface stripe image acquired from the imaging device.
[0061] As an example, a high-precision 3D measurement device for MEMS structured light is configured within the controller of a MEMS structured light high-precision 3D measurement system. For example... Figure 2 The diagram shows a high-precision three-dimensional measurement system for MEMS structured light, in which the controller, projection device, and imaging device are all connected by communication.
[0062] A planar target is placed in the measurement space, a projection device projects a fringe pattern in two orthogonal directions, an imaging device acquires the fringe pattern in two orthogonal directions and obtains the orthogonal phase distribution through phase demodulation by a controller.
[0063] A planar target is a calibration tool with known geometric dimensions. It establishes a unified world coordinate system for high-precision 3D measurement systems of MEMS structured light and accurately calibrates the spatial positional relationships (extrinsic parameters) between components and internal parameters such as lens distortion (intrinsic parameters). Lens distortion corresponds to the internal parameters of the imaging device. Common patterns printed on the surface of planar targets include checkerboard targets, dot array targets, and coded targets.
[0064] Placing a target at a location in the measured space defines a world coordinate plane on its surface. Imaging devices can be calibrated based on this planar target, such as by repeatedly photographing a target with a clear pattern from different orientations and angles. By detecting the correspondence between feature points on the planar target pattern, such as checkerboard corners, in their two-dimensional image coordinates and known three-dimensional world coordinates, the internal and external parameters of the imaging device can be calculated. The internal parameters are called camera intrinsic parameters, including focal length, principal point coordinates, and lens distortion coefficients. The external parameters are called camera extrinsic parameters, which refer to the rotation and translation matrices of the camera relative to the target's position.
[0065] As an example, by using Zhang's calibration method to calibrate the imaging device, the initial intrinsic parameters of the imaging device can be obtained in advance. Initial distortion coefficient and initial external parameters .
[0066] When the controller receives a three-dimensional measurement command for the target, it responds by controlling the projection device to project a bidirectional orthogonal fringe pattern onto the target surface, and then controls the imaging device to acquire the surface fringe image of the target. After acquiring the surface fringe image of the target, the controller performs phase demodulation based on the principle of orthogonal phase consistency to obtain the orthogonal phase distribution of the surface fringe image of the target.
[0067] The orthogonal phase distribution constitutes a unique camera coordinate for the target under test in the coordinate system of the projection device. The controller obtains the orthogonal phase distribution by performing phase demodulation based on the surface fringe image of the target under test as follows: After obtaining four fringe images with different projection phases, the first step is to use multiple phase-shifted images to eliminate environmental influences and obtain the principal value phase of each pixel, also known as the wrapping phase; the second step is to unwrap the phase, as the wrapping phase is discontinuous due to jumps, to obtain a continuous absolute phase corresponding to the object height; the third step is to detect the phase jumps between adjacent pixels and add a period to unwrap the wrapped phase into a continuous, monotonically changing absolute phase field; the fourth step is to continue the above processing on the vertical fringe after unwrapping the phase in the horizontal direction to obtain a continuous absolute phase field in the other direction. Finally, after obtaining the continuous absolute phase fields in two directions, the absolute phase distribution is calculated from the continuous absolute phase field in the horizontal direction and from the continuous absolute phase field in the vertical direction to obtain the orthogonal phase distribution. The orthogonal phase distribution obtained by performing phase demodulation on the surface stripe image of the target under test is denoted as the first orthogonal phase distribution, thus obtaining the first orthogonal phase distribution information about the target under test.
[0068] Unlike previous planar calibration or phase-height mapping methods, which typically rely on high-precision, multi-pose calibration boards, this application establishes the correlation between phase, angle, and ray mapping models, achieving unified and accurate modeling of the calibration space and effectively improving global scale consistency and measurement accuracy.
[0069] After obtaining the first orthogonal phase distribution of the target under test through phase demodulation, the three-dimensional coordinates are accurately matched based on the obtained first orthogonal phase distribution in subsequent steps to achieve three-dimensional reconstruction of the target under test.
[0070] Having obtained the first orthogonal phase distribution of the target object, it is necessary to establish the correlation between phase, angle, and ray mapping model. This correlation accurately characterizes the projection characteristics of the projection device. The process of constructing the correlation between phase, angle, and ray mapping model will be described in detail below.
[0071] S120. Determine the equation of the first spatial line of the fitted projection ray under the preset projection phase in the coordinate system of the imaging device.
[0072] A pre-prepared projection phase, called the preset projection phase, is used as a reference. Matching points corresponding to the same phase are found in the phase distribution of different planar targets. The spatial coordinates of these corresponding points are used to fit the projection ray. The direction of the fitted projection ray is represented by the first spatial straight line equation in the coordinate system of the imaging device.
[0073] As an example, the technicians prepare the data in advance, and the controller acquires the preset projection phase and the first spatial line equation, where the first spatial line equation is the direction vector of the projected light rays that is fitted in advance under the preset projection phase.
[0074] S130. Perform coordinate transformation on the first spatial line equation to obtain the second spatial line equation of the fitted projection ray in the projection device coordinate system, wherein the projection device coordinate system is established based on mutually orthogonal unit vectors, and the mutually orthogonal unit vectors are extracted from the first spatial line equation.
[0075] After the controller determines the first spatial line equation of the fitted projection ray under the preset projection phase in the imaging device coordinate system, it performs a coordinate transformation on the first spatial line equation to obtain the second spatial line equation. The direction vector of the fitted projection ray in the projection device coordinate system is called the second spatial line equation. The following section will introduce how to establish the projection device coordinate system based on the first spatial line equation.
[0076] Prior to S130, including A1-A4:
[0077] A1. By fitting the intersection points of multiple first-space linear equations using the least squares method, the center of the galvanometer of the projection device is obtained.
[0078] The controller fits the center of the galvanometer of the projection device based on the obtained fitted projection rays. As shown in the following equation, the intersection points of multiple first spatial line equations are fitted using the least squares method to obtain the center of the galvanometer of the projection device. .in, It is the total number of projected rays. It is the identity matrix. It is the equation of the first spatial line that fits the projected ray. These are the sampling points on the fitted projected light rays.
[0079]
[0080] A2. Extract the scanning direction from the equation of the first spatial line to obtain the first unit vector and the second unit vector that are orthogonal to each other;
[0081] Extracting the horizontal and vertical directions of the scan from the equation of the first spatial line yields a first orthogonal unit vector and a second unit vector, respectively. and .
[0082] A3. Perform a cross product operation on the first unit vector and the second unit vector to obtain a third unit vector that is orthogonal to both the first unit vector and the second unit vector;
[0083] right and Performing the cross product operation yields the equation of the third spatial line that is orthogonal to both the first and second unit vectors. .
[0084] A4. Establish a three-dimensional spatial coordinate system with the center of the galvanometer as the center of the coordinate system and the first unit vector, the second unit vector, and the third unit vector as the coordinate axes to obtain the projection device coordinate system.
[0085] With the center of the galvanometer Centered on the coordinate system, with the first unit vector Second unit vector and the third unit vector A three-dimensional spatial coordinate system is established for the directions of the coordinate axes to obtain the coordinate system of the projection device.
[0086] Based on this, the coordinate system of the projection device is established based on the equation of the first spatial line in the original imaging device coordinate system.
[0087] By performing coordinate transformation on the first spatial straight line equation, we obtain the second spatial straight line equation dM of the fitted projection ray in the coordinate system of the projection device.
[0088] ,,in, It is the equation of the first spatial line that fits the projected ray. .
[0089] The projection device coordinate system is established based on mutually orthogonal unit vectors, which are extracted from the equation of the first spatial line.
[0090] S140. Based on the correspondence between the second spatial straight line equation and the preset projection phase, determine the mapping model in which the offset angle and the projection phase are mapped to each other, wherein the offset angle refers to the angle by which the second spatial straight line equation deviates from the unit vector in the coordinate system of the projection device.
[0091] Since the second spatial line equation is obtained by coordinate system transformation based on the first spatial line equation, and the first spatial line equation corresponds to the preset projection phase, the first spatial line equation of the fitted projection ray corresponds to the preset projection phase. Therefore, the second spatial line equation also corresponds to the preset projection phase.
[0092] The angle by which the equation of the second spatial line deviates from the unit vector in the coordinate system of the projection device is called the offset angle. As an example, the angle by which the equation of the second spatial line deviates from the first unit vector and the angle by which it deviates from the second unit direction vector are both offset angles.
[0093] Based on the correspondence between the second spatial line equation and the preset projection phase, the mapping relationship between the offset angle of the second spatial line equation and the projection phase is determined, and the mapping model is determined based on this mapping relationship.
[0094] S140 includes S1401-S1404:
[0095] S1401. Determine the offset angle of the second spatial straight line equation relative to the unit vector in the coordinate system of the projection device;
[0096] As an example, the equation of the second spatial line fitted to the projected ray is decomposed into offset angles along two first unit vectors and a second unit vector. Wherein, This represents the deflection angle of the fitted projected light ray along the scanning direction of the first unit vector. This represents the deflection angle of the fitted projection ray along the scanning direction of the second unit vector.
[0097]
[0098] S1402. Based on the correspondence between the offset angle and the preset projection phase, establish an initial mapping model in which the offset angle and the projection phase are mutually mapped.
[0099] Based on the offset angle as well as With preset projection phase The correspondence between them is established, and an initial mapping model is established to map the offset angle and the projection phase to each other.
[0100] As an example, regarding the horizontal phase and vertical direction For the phase, a two-dimensional polynomial mapping model between the phase and the deflection angle is established, i.e.
[0101]
[0102] in, Let be the order of the polynomial. These are the polynomial coefficients, which are the parameters of the mapping model.
[0103] After establishing an initial mapping model that maps offset angles to projection phases, iterative optimization is generally required. The model is validated using pre-set verification data, and the mapping model parameters are then optimized based on feedback. Finally, a mapping model that meets the iteration cutoff condition is obtained. The mapping model parameters are optimized through multiple iterations, resulting in a more accurate mapping model.
[0104] S1403. Obtain the second orthogonal phase distribution information of the preset calibration object used for parameter optimization;
[0105] Set a preset calibration object, which is a type of validation data used to evaluate the current output results when optimizing the mapping model.
[0106] As an example, the preset calibration objects are selected as a standard sphere and a standard plane. The standard sphere and standard plane are placed in the measurement space, and a projection device projects orthogonal fringe patterns onto the surface of the standard sphere and the standard plane. The imaging device acquires the fringe image, and the controller demodulates the phase to obtain the orthogonal phase distribution of the standard sphere. The orthogonal distribution corresponding to the target being measured is called the first orthogonal distribution. For distinction, the orthogonal phase distribution corresponding to preset calibration objects such as the standard sphere is referred to as the second orthogonal phase distribution.
[0107] S1404. Based on the second orthogonal phase distribution information, the initial mapping model is iteratively optimized to obtain the mapping model with optimized mapping model parameters.
[0108] The controller iteratively optimizes the initial mapping model based on the second orthogonal phase distribution information of the standard sphere to obtain the optimized mapping model with parameters a and b.
[0109] S1404 includes B1-B3:
[0110] B1. The initial offset angle of the preset calibration object is obtained by mapping the phase in the second orthogonal phase distribution information through the initial mapping model.
[0111] The phase in the second orthogonal phase distribution information of the standard sphere is mapped using the established initial mapping model to obtain the initial offset angle for model verification.
[0112] B2. Based on the initial offset angle, perform three-dimensional reconstruction on the preset calibration object to obtain a three-dimensional fitted point cloud of the preset calibration object;
[0113] Based on the initial offset angle, the standard sphere and standard plane are reconstructed to obtain their three-dimensional point cloud distribution in the imaging device coordinate system. The difference between the three-dimensional fitted point cloud and the real standard sphere and standard plane is evaluated, and the model is optimized.
[0114] B3. Based on the 3D fitting point cloud of the preset calibration object, the mapping model parameters are iteratively optimized with the goal of minimizing the fitting error, and the optimized mapping model is obtained.
[0115] The goal is to iteratively optimize by minimizing the fitting error.
[0116] In some embodiments, the fitting error includes the sphere center distance fitting error. radius fitting error and the fitting error of the standard plane .
[0117] As an example, the fitting error is the sum of these three errors, where,
[0118]
[0119] w1, w2, and w3 are the weights. For the first The coordinates of the center of each sphere With the The coordinates of the center of each sphere The distance between them For the first The standard ball and the first The true center-to-center distance between standard spheres For the first The true radius of a standard sphere To fit the standard sphere, the three-dimensional points on the surface of the fitted sphere are obtained. To fit the radius of the sphere, The first type of three-dimensional point is obtained by the intersection of the optical center ray of the imaging device and the standard plane. The second type of three-dimensional point is obtained by the intersection of the projected ray and the standard plane. This represents the distance between the first type of 3D point and the second type of 3D point.
[0120] In some embodiments, the mapping model parameters are mapping parameters between the deflection angle and the projection phase. When iteratively optimizing the mapping model, the imaging parameters of the imaging device and the coordinate system of the projection device are also optimized. The imaging parameters include intrinsic parameters.
[0121] In addition to optimizing the mapping model parameters, the imaging parameters of the imaging device and the coordinate system of the projection device are used in the process of optimizing the mapping model. Therefore, these parameters are also optimized at the same time.
[0122] S150. Based on the mapping model, the phase in the first orthogonal phase distribution information is mapped to obtain the first offset angle of the corresponding projection ray of the target under test in the coordinate system of the projection device.
[0123] After model optimization, the optimized mapping model parameters, the intrinsic parameters of the imaging device, and the projection device coordinate system (e.g., first unit vector, second unit vector, and third unit vector) are obtained. Based on these optimized parameters, the phase in the first orthogonal phase distribution information of the target is mapped to find the corresponding offset angle. This offset angle is the first offset angle of the projected ray from the target in the projection device coordinate system. As an example, the first offset angle can be divided into an offset angle on the horizontal axis and an offset angle on the vertical axis.
[0124] S160. Based on the first offset angle, determine the point cloud of the target under test involved on the projected light ray, and obtain the three-dimensional coordinates of the target under test in space.
[0125] Based on the first offset angle, the point cloud of the target under test involved on the projected ray is obtained by fitting, and the three-dimensional coordinates of the target under test in space are determined.
[0126] S160, including S1601-S1605:
[0127] S1601. Based on the first offset angle, determine the equation of the third spatial line of the projection ray when projecting onto the target under test in the coordinate system of the projection device.
[0128] Based on the first offset angle, the equation of the third spatial line of the projection ray when projecting onto the target is determined in the coordinate system of the projection device.
[0129] In the above description, the first spatial straight line equation is determined based on the offset angle in the coordinate system of the projection device. Here, the third spatial straight line equation can also be determined in reverse based on the offset angle.
[0130] S1602. Perform coordinate transformation on the third spatial line equation to obtain the fourth spatial line equation of the projection ray when projecting onto the target under test in the coordinate system of the imaging device, wherein the fourth spatial line equation represents the projection ray when projecting onto the target under test from the perspective of the imaging device.
[0131] By performing a coordinate transformation on the third spatial line equation, a fourth spatial line equation in the imaging device coordinate system is obtained. This fourth spatial line equation represents the projected ray when projecting onto the target object from the imaging device's perspective.
[0132] S1603. Based on the fourth spatial linear equation and the imaging parameters of the imaging device, the optical center ray of the imaging device is calculated.
[0133] Based on the optimized imaging parameters of the imaging device, such as internal parameters, the equation of the fourth spatial line is calculated, the camera rays corresponding to each pixel are calculated, and the optical center ray of the imaging device is obtained. The optical center ray of the imaging device is also the camera ray.
[0134] S1604. Based on the intersection point between the optical center ray of the imaging device and the projection ray when projecting onto the target, determine the surface point cloud of the target.
[0135] The surface point cloud of the target is determined based on the intersection point between the camera ray and the projected ray when projecting onto the target.
[0136] S1605. The three-dimensional coordinates of the surface point cloud of the target to be measured are used as the three-dimensional coordinates of the target to be measured in space.
[0137] The three-dimensional coordinates of the surface point cloud of the target to be tested are used as the three-dimensional coordinates of the target to be tested in space.
[0138] This application provides a method, apparatus, device, and medium for high-precision three-dimensional measurement of MEMS structured light. The method includes: responding to a three-dimensional measurement command for a target under test, determining first orthogonal phase distribution information of the target under test based on a surface stripe image acquired from the imaging device; determining a first spatial straight line equation of a fitted projection ray under a preset projection phase in the coordinate system of the imaging device; performing coordinate transformation on the first spatial straight line equation to obtain a second spatial straight line equation of the fitted projection ray in the coordinate system of the projection device, wherein the coordinate system of the projection device is established based on mutually orthogonal unit vectors, which are extracted from the first spatial straight line equation; determining a mapping model that maps the offset angle to the projection phase based on the correspondence between the second spatial straight line equation and the preset projection phase, wherein the offset angle refers to the angle by which the second spatial straight line equation deviates from the unit vector in the coordinate system of the projection device; mapping the phase in the first orthogonal phase distribution information based on the mapping model to obtain a first offset angle of the corresponding projection ray of the target under test in the coordinate system of the projection device; and determining the point cloud of the target under test involved on the projection ray based on the first offset angle to obtain the three-dimensional coordinates of the target under test in space. In this application, without relying on a high-precision calibration plate, the correlation between phase and angle and ray mapping model is established, accurately characterizing the projection characteristics of the projection device, and solving the technical problem of low accuracy when performing three-dimensional measurements based on MEMS structured light systems.
[0139] Figure 3 This is a schematic block diagram of a MEMS structured light high-precision three-dimensional measurement device provided in an embodiment of this application. Figure 3As shown, corresponding to the above-described MEMS structured light high-precision three-dimensional measurement method, this application also provides a MEMS structured light high-precision three-dimensional measurement device 600. The MEMS structured light high-precision three-dimensional measurement device is configured in the controller of a MEMS structured light high-precision three-dimensional measurement system. The MEMS structured light high-precision three-dimensional measurement system includes a projection device and an imaging device. The controller establishes a communication connection with the projection device and the imaging device. First, the projection device is controlled to project a bi-directional orthogonal fringe pattern onto the surface of the target to be measured. Then, the imaging device is controlled to acquire the surface fringe image of the target to be measured. The MEMS structured light high-precision three-dimensional measurement device 600 includes a unit for performing the above-described MEMS structured light high-precision three-dimensional measurement. The MEMS structured light high-precision three-dimensional measurement device 600 can be configured in terminals such as desktop computers, tablet computers, and laptops. For details, please refer to... Figure 3 The MEMS structured light high-precision three-dimensional measurement device 600 includes a first determining unit 601, a first determining unit 602, a coordinate transformation unit 603, a third determining unit 604, a mapping unit 605, and a fourth determining unit 606, wherein:
[0140] The first determining unit 601 is configured to, in response to a three-dimensional measurement command for the target under test, determine first orthogonal phase distribution information about the target under test based on a surface stripe image acquired from the imaging device.
[0141] The second determining unit 602 is used to determine the first spatial straight line equation of the fitted projection ray under the preset projection phase in the coordinate system of the imaging device.
[0142] The coordinate transformation unit 603 is used to perform coordinate transformation on the first spatial straight line equation to obtain the second spatial straight line equation of the fitted projection ray in the projection device coordinate system, wherein the projection device coordinate system is established based on mutually orthogonal unit vectors, and the mutually orthogonal unit vectors are extracted from the first spatial straight line equation.
[0143] The third determining unit 604 is used to determine a mapping model in which the offset angle and the projection phase are mapped to each other based on the correspondence between the second spatial straight line equation and the preset projection phase, wherein the offset angle refers to the angle by which the second spatial straight line equation deviates from the unit vector in the coordinate system of the projection device.
[0144] Mapping unit 605 is used to map the phase in the first orthogonal phase distribution information based on the mapping model to obtain the first offset angle of the projection ray of the target under test in the coordinate system of the projection device.
[0145] The fourth determining unit 606 is used to determine the point cloud of the target under test involved on the projection ray based on the first offset angle, and obtain the three-dimensional coordinates of the target under test in space.
[0146] In some embodiments, the third determining unit 604, in executing the correspondence between the second spatial straight line equation and the preset projection phase, determines a mapping model that maps the offset angle to the projection phase, specifically for:
[0147] Determine the offset angle of the second spatial straight line equation relative to the unit vector in the coordinate system of the projection device;
[0148] Based on the correspondence between the offset angle and the preset projection phase, an initial mapping model is established that maps the offset angle to the projection phase.
[0149] Obtain the second orthogonal phase distribution information of the preset calibration material used for parameter optimization;
[0150] Based on the second orthogonal phase distribution information, the initial mapping model is iteratively optimized to obtain the mapping model with optimized parameters.
[0151] In some embodiments, the mapping model parameters are mapping parameters between the deflection angle and the projection phase. When iteratively optimizing the mapping model, the imaging parameters of the imaging device and the coordinate system of the projection device are also optimized. The imaging parameters include intrinsic parameters and distortion coefficients.
[0152] In some embodiments, the third determining unit 604 performs iterative optimization of the initial mapping model based on the second orthogonal phase distribution information to obtain a mapping model with optimized mapping model parameters, specifically for:
[0153] The initial offset angle of the preset calibration object is obtained by mapping the phase in the second orthogonal phase distribution information through the initial mapping model.
[0154] Based on the initial offset angle, the preset calibration object is reconstructed in three dimensions to obtain a three-dimensional fitted point cloud of the preset calibration object;
[0155] Based on the 3D fitted point cloud of the preset calibration object, the mapping model parameters are iteratively optimized with the goal of minimizing the fitting error, and the optimized mapping model is obtained.
[0156] In some embodiments, when the third determining unit 604 performs three-dimensional reconstruction of the preset calibration object based on the initial offset angle to obtain a three-dimensional fitted point cloud of the preset calibration object, the preset calibration object includes a standard sphere and a standard plane, and correspondingly, the fitting error includes the sphere center distance fitting error. radius fitting error and the fitting error of the standard plane The fitting error is , as well as The sum of, among which,
[0157]
[0158] w1, w2, and w3 are the weights. For the first The coordinates of the center of each sphere With the The coordinates of the center of each sphere The distance between them For the first The standard ball and the first The true center-to-center distance between standard spheres To fit the standard sphere, the three-dimensional points on the surface of the fitted sphere are obtained. For the first The true radius of a standard sphere To fit the radius of the sphere, The first type of three-dimensional point is obtained by the intersection of the optical center ray of the imaging device and the standard plane. The second type of three-dimensional point is obtained by the intersection of the projected ray and the standard plane. This represents the distance between the first type of 3D point and the second type of 3D point.
[0159] In some embodiments, the fourth determining unit 606, when performing the task of determining the point cloud of the target under test on the projection ray based on the first offset angle, and obtaining the three-dimensional coordinates of the target under test in space, is specifically used for:
[0160] Based on the first offset angle, the equation of the third spatial line of the projection ray when projecting onto the target is determined in the coordinate system of the projection device.
[0161] The third spatial line equation is transformed to obtain the fourth spatial line equation of the projection ray when the target is projected in the coordinate system of the imaging device. The fourth spatial line equation represents the projection ray when the target is projected in the view of the imaging device.
[0162] The imaging device is calculated based on the fourth spatial linear equation and the imaging parameters of the imaging device.
[0163] Optical center rays;
[0164] The surface point cloud of the target is determined based on the intersection point between the optical center ray of the imaging device and the projected ray when the target is projected.
[0165] The three-dimensional coordinates of the surface point cloud of the target to be tested are used as the three-dimensional coordinates of the target to be tested in space.
[0166] In some embodiments, before performing coordinate transformation on the first spatial straight line equation to obtain the second spatial straight line equation of the fitted projection ray in the coordinate system of the projection device, the coordinate transformation unit 603 is specifically used for:
[0167] The center of the galvanometer of the projection device is obtained by fitting the intersection points of multiple first spatial line equations using the least squares method.
[0168] The scanning direction is extracted from the equation of the first spatial line to obtain a first unit vector and a second unit vector that are orthogonal to each other.
[0169] Perform a cross product operation on the first unit vector and the second unit vector to obtain a third unit vector that is orthogonal to both the first unit vector and the second unit vector;
[0170] A spatial three-dimensional coordinate system is established with the center of the galvanometer as the center of the coordinate system, and the first unit vector, the second unit vector, and the third unit vector as the coordinate axes, thus obtaining the coordinate system of the projection device.
[0171] This application provides a high-precision MEMS structured light three-dimensional measurement device. In this application, without relying on a high-precision calibration plate, the correlation between phase and angle and ray mapping model is established to accurately characterize the projection characteristics of the projection device, thus solving the technical problem of low accuracy when performing three-dimensional measurements based on MEMS structured light systems.
[0172] It should be noted that those skilled in the art can clearly understand that the specific implementation process of the above-mentioned MEMS structured light high-precision three-dimensional measurement device and each unit can be referred to the corresponding description in the foregoing method embodiments. For the sake of convenience and brevity, it will not be repeated here.
[0173] The aforementioned MEMS structured light high-precision three-dimensional measurement device can be implemented as a computer program, which can be used in, for example... Figure 4 It runs on the device shown.
[0174] Please see Figure 4 , Figure 4 This is a schematic block diagram of a device provided in an embodiment of this application. The device 700 can be a terminal or a server. The terminal can be an electronic device with communication functions, such as a smartphone, tablet, laptop, desktop computer, personal digital assistant, or wearable device. The server can be a standalone server or a server cluster composed of multiple servers.
[0175] See Figure 4 The device 700 includes a processor 702, a memory, and a network interface 705 connected via a system bus 701, wherein the memory may include a non-volatile medium 703 and internal memory 704.
[0176] The non-volatile medium 703 can store an operating system 7031 and a computer program 7032. The computer program 7032 includes program instructions that, when executed, cause the processor 702 to perform a high-precision three-dimensional measurement using MEMS structured light.
[0177] The processor 702 provides computing and control capabilities to support the operation of the entire device 700.
[0178] The internal memory 704 provides an environment for the operation of the computer program 7032 in the non-volatile medium 703. When the computer program 7032 is executed by the processor 702, the processor 702 can perform a high-precision three-dimensional measurement of MEMS structured light.
[0179] This network interface 705 is used for network communication with other devices. Those skilled in the art will understand that... Figure 4 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the device 700 to which the present application is applied. The specific device 700 may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.
[0180] The processor 702 is used to run the computer program 7032 stored in the memory to perform the following steps:
[0181] The receiving terminal acquires a first signal from the sending terminal and a second signal fed back from the target drone. The second signal and the first signal are sent from the sending terminal at the same time, received by the target drone, and then fed back to the receiving terminal.
[0182] The time difference when the receiving terminal sequentially acquires the first signal and the second signal, and the angle of arrival when the second signal is fed back to the receiving terminal are determined.
[0183] The estimated position of the target UAV is obtained by jointly calculating the preset first functional relationship and the preset second functional relationship using the least squares method. The first functional relationship refers to the functional relationship between the time difference and the position of the target UAV and the first propagation error, and the second functional relationship refers to the functional relationship between the wave angle and the position of the target UAV and the second propagation error.
[0184] It should be understood that in the embodiments of this application, the processor 702 may be a central processing unit (CPU), or it may be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.
[0185] It will be understood by those skilled in the art that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program includes program instructions and can be stored in a medium, which is a computer-readable medium. The program instructions are executed by at least one processor in the computer system to implement the process steps of the embodiments of the above methods.
[0186] Therefore, this application also provides a medium. This medium can be a computer-readable medium. The medium stores a computer program, wherein the computer program includes program instructions. When executed by a processor, the program instructions cause the processor to perform the following steps:
[0187] The receiving terminal acquires a first signal from the sending terminal and a second signal fed back from the target drone. The second signal and the first signal are sent from the sending terminal at the same time, received by the target drone, and then fed back to the receiving terminal.
[0188] The time difference when the receiving terminal sequentially acquires the first signal and the second signal, and the angle of arrival when the second signal is fed back to the receiving terminal are determined.
[0189] The estimated position of the target UAV is obtained by jointly calculating the preset first functional relationship and the preset second functional relationship using the least squares method. The first functional relationship refers to the functional relationship between the time difference and the position of the target UAV and the first propagation error, and the second functional relationship refers to the functional relationship between the wave angle and the position of the target UAV and the second propagation error.
[0190] The medium can be any computer-readable medium that can store program code, such as a USB flash drive, external hard drive, read-only memory (ROM), magnetic disk, or optical disk.
[0191] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this application.
[0192] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For example, the division of each unit is merely a logical functional division, and there may be other division methods in actual implementation. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed.
[0193] The steps in the methods of this application embodiment can be adjusted, merged, or deleted according to actual needs. The units in the apparatus of this application embodiment can be merged, divided, or deleted according to actual needs. Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.
[0194] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a medium and includes several instructions to cause a device (which may be a personal computer, a terminal, or a network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application.
[0195] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. A high-precision three-dimensional measurement method for MEMS structured light, characterized in that, The MEMS structured light high-precision three-dimensional measurement method is applied to the controller of a MEMS structured light high-precision three-dimensional measurement system. The MEMS structured light high-precision three-dimensional measurement system includes a projection device and an imaging device. The controller establishes a communication connection with both the projection device and the imaging device. First, the projection device is controlled to project a bi-directional orthogonal fringe pattern onto the surface of the target to be measured. Then, the imaging device is controlled to acquire the surface fringe image of the target to be measured. The MEMS structured light high-precision three-dimensional measurement method includes: In response to a three-dimensional measurement command for the target under test, a first orthogonal phase distribution information about the target under test is determined based on a surface stripe image acquired from the imaging device. Determine the equation of the first spatial line of the fitted projection ray under the preset projection phase in the coordinate system of the imaging device; The first spatial line equation is transformed to obtain the second spatial line equation of the fitted projection ray in the projection device coordinate system. The projection device coordinate system is established based on mutually orthogonal unit vectors, which are extracted from the first spatial line equation. Based on the correspondence between the second spatial straight line equation and the preset projection phase, a mapping model is determined that maps the offset angle to the projection phase. The offset angle refers to the angle by which the second spatial straight line equation deviates from the unit vector in the coordinate system of the projection device. Based on the mapping model, the phase in the first orthogonal phase distribution information is mapped to obtain the first offset angle of the projected ray of the target under test in the coordinate system of the projection device. Based on the first offset angle, the point cloud of the target under test involved on the projected ray is determined, and the three-dimensional coordinates of the target under test in space are obtained.
2. The method according to claim 1, characterized in that, The mapping model that determines the mapping between the offset angle and the projection phase based on the correspondence between the second spatial straight line equation and the preset projection phase includes: Determine the offset angle of the second spatial straight line equation relative to the unit vector in the coordinate system of the projection device; Based on the correspondence between the offset angle and the preset projection phase, an initial mapping model is established that maps the offset angle to the projection phase. Obtain the second orthogonal phase distribution information of the preset calibration material used for parameter optimization; Based on the second orthogonal phase distribution information, the initial mapping model is iteratively optimized to obtain the mapping model with optimized parameters.
3. The method according to claim 2, characterized in that, The mapping model parameters are the mapping parameters between the deflection angle and the projection phase. When iteratively optimizing the mapping model, the imaging parameters of the imaging device and the coordinate system of the projection device are also optimized. The imaging parameters include intrinsic parameters and distortion coefficients.
4. The method according to claim 2, characterized in that, The iterative optimization of the initial mapping model based on the second orthogonal phase distribution information to obtain the optimized mapping model includes: The initial offset angle of the preset calibration object is obtained by mapping the phase in the second orthogonal phase distribution information through the initial mapping model. Based on the initial offset angle, the preset calibration object is reconstructed in three dimensions to obtain a three-dimensional fitted point cloud of the preset calibration object; Based on the 3D fitted point cloud of the preset calibration object, the mapping model parameters are iteratively optimized with the goal of minimizing the fitting error, and the optimized mapping model is obtained.
5. The method according to claim 4, characterized in that, The preset calibration objects include a standard sphere and a standard plane; correspondingly, the fitting error includes the fitting error of the distance between the sphere's center and the target surface. radius fitting error and the fitting error of the standard plane The fitting error is , as well as The sum of, among which, w1, w2, and w3 are the weights. For the first The coordinates of the center of each sphere With the The coordinates of the center of each sphere The distance between them For the first The standard ball and the first The true center-to-center distance between standard spheres To fit the standard sphere, the three-dimensional points on the surface of the fitted sphere are obtained. For the first The true radius of a standard sphere To fit the radius of the sphere, The first type of three-dimensional point is obtained by the intersection of the optical center ray of the imaging device and the standard plane. The second type of three-dimensional point is obtained by the intersection of the projected ray and the standard plane. This represents the distance between the first type of 3D point and the second type of 3D point.
6. The method according to claim 1, characterized in that, The step of determining the point cloud of the target under test on the projected ray based on the first offset angle, and obtaining the three-dimensional coordinates of the target under test in space, includes: Based on the first offset angle, the equation of the third spatial line of the projection ray when projecting onto the target is determined in the coordinate system of the projection device. The third spatial line equation is transformed to obtain the fourth spatial line equation of the projection ray when the target is projected in the coordinate system of the imaging device. The fourth spatial line equation represents the projection ray when the target is projected in the view of the imaging device. The imaging device is calculated based on the fourth spatial linear equation and the imaging parameters of the imaging device. Optical center rays; The surface point cloud of the target is determined based on the intersection point between the optical center ray of the imaging device and the projected ray when the target is projected. The three-dimensional coordinates of the surface point cloud of the target to be tested are used as the three-dimensional coordinates of the target to be tested in space.
7. The method according to claim 1, characterized in that, Before performing coordinate transformation on the first spatial straight line equation to obtain the second spatial straight line equation of the fitted projection ray in the projection device coordinate system, the process includes: The center of the galvanometer of the projection device is obtained by fitting the intersection points of multiple first spatial line equations using the least squares method. The scanning direction is extracted from the equation of the first spatial line to obtain a first unit vector and a second unit vector that are orthogonal to each other. Perform a cross product operation on the first unit vector and the second unit vector to obtain a third unit vector that is orthogonal to both the first unit vector and the second unit vector; A spatial three-dimensional coordinate system is established with the center of the galvanometer as the center of the coordinate system, and the first unit vector, the second unit vector, and the third unit vector as the coordinate axes, thus obtaining the coordinate system of the projection device.
8. A high-precision three-dimensional measurement device for MEMS structured light, characterized in that, The MEMS structured light high-precision three-dimensional measurement device is configured in the controller of the MEMS structured light high-precision three-dimensional measurement system. The MEMS structured light high-precision three-dimensional measurement system includes a projection device and an imaging device. The controller establishes a communication connection with the projection device and the imaging device. First, the controller controls the projection device to project a bi-directional orthogonal fringe pattern onto the surface of the target to be measured. Then, the controller controls the imaging device to acquire the surface fringe image of the target to be measured. The MEMS structured light high-precision three-dimensional measurement device includes: The first determining unit is configured to, in response to a three-dimensional measurement command for the target under test, determine first orthogonal phase distribution information about the target under test based on a surface stripe image acquired from the imaging device. The second determining unit is used to determine the first spatial straight line equation of the fitted projection ray under the preset projection phase in the coordinate system of the imaging device. The coordinate transformation unit is used to perform coordinate transformation on the first spatial line equation to obtain the second spatial line equation of the fitted projection ray in the projection device coordinate system, wherein the projection device coordinate system is established based on mutually orthogonal unit vectors, which are extracted from the first spatial line equation. The third determining unit is used to determine a mapping model in which the offset angle and the projection phase are mapped to each other based on the correspondence between the second spatial straight line equation and the preset projection phase, wherein the offset angle refers to the angle by which the second spatial straight line equation deviates from the unit vector in the coordinate system of the projection device. The mapping unit is used to map the phase in the first orthogonal phase distribution information based on the mapping model to obtain the first offset angle of the corresponding projection ray of the target under test in the coordinate system of the projection device. The fourth determining unit is used to determine the point cloud of the target under test on the projected ray based on the first offset angle, and to obtain the three-dimensional coordinates of the target under test in space.
9. A high-precision three-dimensional measurement device for MEMS structured light, characterized in that, The device includes a memory, a processor, and a MEMS structured light high-precision three-dimensional measurement program stored in the memory and executable on the processor. The processor executes the MEMS structured light high-precision three-dimensional measurement program to perform the steps of MEMS structured light high-precision three-dimensional measurement as described in any one of claims 1 to 7.
10. A medium, characterized in that, The medium stores a program for implementing high-precision three-dimensional measurement of MEMS structured light, which is executed by a processor to implement the steps of high-precision three-dimensional measurement of MEMS structured light as described in any one of claims 1 to 7.
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