Structured light three-dimensional modeling equipment

Abstract

The utility model provides structured light three-dimensional modeling equipment, which comprises a projection module used for projecting a grating pattern formed based on a DeBruijin coding mode to the surface of an object to be measured, the projection module comprises a transmitting unit and a grating sheet, the grating sheet is provided with a grating stripe sequence formed based on the DeBruijin coding mode, and the transmitting unit is used for transmitting the grating stripe sequence to the surface of the object to be measured. Light emitted by the emitting unit passes through the grating stripe sequence of the grating sheet to form a preset grating pattern; the camera module is used for acquiring a projection image after the projection module projects the grating pattern to the to-be-measured object; and the control module is connected with and controls the projection module and the camera module, and is used for establishing a three-dimensional model of the to-be-measured object according to the projection image acquired by the camera module. According to the technical scheme, the structure is simple, cost is low, precision is high, small-batch production can be achieved, and application in the wide fields of industrial manufacturing, medical cosmetology, cultural relic protection and the like is completely met.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of three-dimensional modeling, in particular to a structured light three-dimensional modeling device. BACKGROUND

[0002] The structured light three-dimensional modeling technology refers to a technology of using active projection structured light to realize three-dimensional modeling. It is a high-speed and high-precision three-dimensional modeling method, which is widely used in industrial manufacturing, medical beauty, cultural relic protection and other fields.

[0003] The current three-dimensional modeling technology on the market mainly falls into three categories: 1. Passive three-dimensional modeling technology, based on ambient light three-dimensional modeling technology, such as binocular three-dimensional modeling, which is cheap and easy to implement, but has low modeling accuracy in places lacking of characteristic points, and even cannot model, such as facing a white wall. 2. Tof flight time modeling technology, which is cheap and fast, but has poor accuracy, centimeter-level accuracy. 3. Active structured light three-dimensional modeling technology, active projection structured light, structured light can be coded speckle, phase diagram, debruijn stripe code, etc., the modeling accuracy is very high, which can reach micrometer level, and the price varies greatly according to the implementation method.

[0004] The active structured light three-dimensional modeling technology on the current market, also known as structured light modeling technology, has three main implementation approaches:

[0005] 1. Coded speckle structured light, which projects coded speckle, decodes and generates point cloud after camera acquisition. It is cheap, but the point cloud is sparse, resulting in low accuracy. In addition, the initial production cost is high, and for small batches of products, chips and modules produced by other large companies are used, which is subject to suppliers.

[0006] 2. DLP (“Digital Light Processing”, digital light processing) structured light, which projects different frequency phase shift patterns for modeling, has high accuracy and many point clouds, but is limited by foreign DMD chips, and the price is very high.

[0007] 3. MEMS mirror (“Micro-Electro-Mechanical Systems”, micro-electromechanical systems mirror) structured light, which has a similar principle to DLP structured light, but uses a micro motor instead of a chip, which projects a column of data each time, but because of its high speed, it can project a picture within the exposure period of the camera. Its price is much cheaper than the DLP scheme, but it is not cheap, and for small batches of products, chips and modules produced by other large companies are used, which is subject to suppliers.

[0008] The foregoing three implementation approaches have disadvantages, the low-precision one is cheap (the coded speckle technology), the high-precision one is relatively expensive (such as the DLP technology and the MEMS mirror technology), and all of them are subject to the corresponding chip providers (the coded speckle technology, the DLP technology and the MEMS mirror technology all need professional chips or modules), which are not conducive to long-term delivery and small-batch production. Practical new type content

[0009] The utility model discloses a structure light three-dimensional modeling device, which is cheap, high-precision and can realize small-batch production, and fully meets the application in the fields of industrial manufacturing, medical cosmetology and cultural relic protection.

[0010] According to the embodiment of the utility model discloses a structure light three-dimensional modeling device, include: projection module is used to project the grating pattern formed based on DeBruijin coding mode to the surface of the object to be measured, it includes: emitting unit and grating sheet, grating sheet is equipped with the grating fringe sequence formed based on DeBruijin coding mode, and the light emitted by emitting unit passes through the grating fringe sequence of grating sheet and forms the grating pattern of preset; Camera module is used to obtain the projection image after the grating pattern of projection module is projected to the object to be measured;Control module is connected and controls projection module and camera module, and it is used to establish the three-dimensional model of the object to be measured according to the projection image of camera module acquisition.

[0011] Preferably, the grating sheet is a black substrate, and the grating fringe sequence includes a plurality of parallel vertical and equidistantly arranged fringes on the black substrate, and the fringes are arranged in a DeBruijin coding manner, wherein the fringes have the same line width and are at least one of green, blue and cyan in color.

[0012] Preferably, the grating fringe sequence further includes a calibration fringe transversely arranged on the grating sheet, and the calibration fringe is at least one of green, blue and cyan in color.

[0013] Preferably, the camera module includes a monocular camera or a binocular camera.

[0014] Preferably, the emitting unit comprises a shell, a heat sink, a control board, a cover plate, an LED array, a condenser lens, a collimating lens, a right-angle prism and a projection lens; the LED array is arranged on one side of the control board, the heat sink is arranged on the other side of the control board, and the condenser lens, the collimating lens, the right-angle prism and the projection lens are sequentially arranged on one side of the light-emitting direction of the LED array.

[0015] Preferably, the structured light three-dimensional modeling device further comprises a bracket for fixing the projection module and the camera module.

[0016] Preferably, the structured light three-dimensional modeling device further comprises a heat dissipation module connected to the projection module and the camera module.

[0017] Preferably, the control board comprises a power module, an MCU control module and an LED interface and switch module, the power module is connected to the MCU control module and the LED interface and switch module, the MCU control module is connected to the LED interface and switch module, and the LED interface and switch module is connected to the LED array.

[0018] Preferably, the LED array comprises a white light LED lamp or three infrared LED lamps arranged in a triangular shape.

[0019] Preferably, the camera module is a 200W camera module.

[0020] The additional aspects and advantages of the present application will be partially given in the following description, and some will become apparent from the following description, or will be understood by those skilled in the art through practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0021] The above and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

[0022] Figure 1 is a top view of the structured light three-dimensional modeling device of the present application;

[0023] Figure 2 is Figure 1 a front view of the structured light three-dimensional modeling device of the present application;

[0024] Figure 3 is Figure 1 a bottom view of the structured light three-dimensional modeling device of the present application;

[0025] Figure 4 is a grating stripe sequence of the present application;

[0026] Figure 5 is a grating stripe sequence of another embodiment of the present application

[0027] Figure 6It is the structure explosion map of the projection module in the application;

[0028] Figure 7 It is the top view of the structured light three-dimensional modeling device of another embodiment of the application.

[0029] Explanation of reference numerals: projection module 1 shell 11 heat dissipation fin 12 control panel 13 power module, MCU control module LED interface switch module cover plate 14 LED array 15 condensing lens 16 collimating lens 17 right-angle prism 18 projection lens 19 grating sheet 10 camera module 2 control module 3 support 4 heat sink 5. DETAILED DESCRIPTION

[0030] The embodiments of the application are described in detail below, and examples of the embodiments are shown in the drawings, wherein the same or similar numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the application, and cannot be understood as a limitation of the application.

[0031] In the description of the application, it should be understood that, in relation to the orientation description, for example, the orientation or position relationship indicated by up, down, front, back, left, right, etc. is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the application and simplifying the description, and therefore cannot be understood as a limitation of the application. In the description of the application, it should be noted that the terms "first", "second", etc. are only used for description purposes, and cannot be understood as indicating or implying relative importance.

[0032] In the description of the application, unless otherwise explicitly limited, the words such as setting, installing, connecting, etc. should be understood in a broad sense, and the person skilled in the art can reasonably determine the specific meaning of the above words in the application in combination with the specific content of the technical solution.

[0033] Please refer to Figures 1 to 7 The application provides a structured light three-dimensional modeling device, which comprises a projection module 1, a camera module 2 and a control module 3. The projection module 1 is used for projecting a grating pattern formed based on a DeBruijin coding mode to the surface of a to-be-measured object, and comprises an emitting unit and a grating sheet 10. The grating sheet 10 is provided with a grating fringe sequence formed based on the DeBruijin coding mode. The emitting unit emits light rays, and after the light rays pass through the grating fringe sequence of the grating sheet 10, a preset grating pattern is formed. The camera module 2 is used for acquiring a projection image after the projection module 1 projects the grating pattern to the to-be-measured object. The control module 3 is connected and controls the projection module 1 and the camera module 2, and is used for establishing a three-dimensional model of the to-be-measured object according to the projection image acquired by the camera module 2.

[0034] In this embodiment, the grating sheet 10 is a black substrate, and the grating fringe sequence includes a plurality of fringes vertically and equally spaced on the black substrate, and the fringes are arranged in a DeBruijin coding manner, wherein the line widths of the fringes are the same, and the color is at least one of green, blue and cyan.

[0035] In this embodiment, the grating fringe sequence on the black substrate of the grating sheet 10 is encoded by using 3 colors (green, blue and cyan) for 5 bits, and a total of 3^5 lines, i.e. 243 lines, can be encoded. According to the Debruijn characteristics, the continuous 5 lines have uniqueness in the entire coding space, so at least 5 continuous points are found in the three-dimensional modeling calculation point cloud to locate its position in the entire sequence, and the normal point cloud can be decoded. The characteristics and sequence generation method of Debruijn are not described here. In terms of grating fringe sequence manufacturing process, the width and spacing of the fringes are controlled by photolithography process, and the fringes can be produced by coloring or wavelength coating. When the emission unit emits white light, different coloring or different coating transmits light of different colors of the fringes, thereby projecting a colored Debruijn sequence.

[0036] Please refer to Figure 4 , Figure 4 It is a common grating sheet, and the coding forms 92 lines. The grating fringe sequence formed by the Debruijn coding manner can locate its position in the entire sequence when the three-dimensional modeling calculation point cloud is calculated. As can be seen from left to right, the first fringe is green, the second fringe is cyan, the third fringe is blue, the fourth fringe is cyan, and the fifth fringe is green. With the continuous 5 fringes as a group, the positioning of the point cloud in the region can be realized. Figure 2 The grating without projection correction function can be used in occasions with low edge accuracy requirements.

[0037] In other embodiments, an infrared grating scheme is also proposed for an infrared camera. Unlike color, infrared imaging on a camera has only one color. To produce theoretical color, different wavelengths of light must be used instead of different colors. Therefore, we coat the grating with different films. At the same time, we need two different wavelengths of infrared LED to light alternately, and after the camera captures two images, the 850nm infrared image is marked as green, the 940nm infrared image is marked as blue, and the line marked as cyan is the line that 850nm and 940nm are imaged at the same time. In this way, the coding is completed.

[0038] In order to meet the requirement of high accuracy, in another embodiment, a high-precision grating scheme is also designed, such as Figure 5As shown, the grating stripe sequence also includes: horizontally arranged calibration stripes on the grating plate 10, the color of which is at least one of green, blue, and cyan. The high-precision grating uses 125 lines. This high-precision grating scheme has a projection correction function and can be used in applications requiring high precision. In addition to the normal Debruijn coded stripes, it adds horizontal cyan lines, which can extract the intersection points of the horizontal and vertical lines to calibrate the intrinsic parameters of the projection module 1 and the lens distortion of the camera module 2.

[0039] Please see Figure 6 The transmitting unit includes a housing 11, a heat sink 12, a control board 13, a cover plate 14, an LED array 15, a focusing lens 16, a collimating lens 17, a right-angle prism 18, and a projection lens 19.

[0040] The LED array 15 is located on one side of the control board 13, the heat sink 12 is located on the other side of the control board 13, and the focusing lens 16, collimating lens 17, right-angle prism 18, and projection lens 19 are fixedly located inside the housing 11 and are arranged sequentially on one side of the light emission direction of the LED array 15.

[0041] In this embodiment, since the projection requires high-power LED lights, a heat sink 12 is required.

[0042] In this embodiment, the control board 13 is made of copper, which can accelerate heat dissipation.

[0043] In this embodiment, if it is as follows Figure 4 or Figure 5 The colored stripe scheme uses one 10W white LED light, while the infrared scheme uses one 3W 850nm and two 3W 940nm infrared LED lights arranged in a triangular pattern.

[0044] In this embodiment, the right-angle prism 18 can turn the path of light by 90°, which makes the entire optomechanical structure more compact.

[0045] The control board 13 includes a power module, an MCU control module, and an LED interface and switch module. The power module is connected to the MCU control module and the LED interface and switch module. The MCU control module is connected to the LED interface and switch module. The LED interface and switch module is connected to the LED array 15.

[0046] Please see Figures 1 to 3 , Figure 7 In one embodiment, camera module 2 includes a single camera, and is referred to as a monocular device. In another embodiment, camera module 2 includes two cameras, and is referred to as a binocular device, with projection module 1 positioned between the two cameras.

[0047] The camera can use any camera, the higher the resolution of the camera, the higher the accuracy, the lower the resolution of the camera, the lower the accuracy. The camera used by the device is a 400W GC4053 and a 200W GC2053 camera module 2.

[0048] In other embodiments, the structured light three-dimensional modeling device further comprises a bracket for fixing the projection module 1 and the camera module 2, which is designed with metal material to prevent deformation during use and cause accuracy errors.

[0049] In other embodiments, the structured light three-dimensional modeling device further comprises a heat dissipation module connected to the projection module 1 and the camera module 2. This can synchronize the heat dissipation of the projection module 1 and the camera module 2.

[0050] It should be particularly pointed out that the structured light three-dimensional modeling device must be accurately calibrated before leaving the factory. This is because there are significant differences in the production process, including but not limited to chip errors, structural errors, and assembly errors. These errors, if not corrected, will directly affect the measurement accuracy and modeling effect of the device, and may lead to error accumulation and performance degradation in subsequent applications. Therefore, the calibration process is particularly important, which adjusts and optimizes various parameters of the device to ensure that each device meets the preset performance standards.

[0051] Device calibration mainly in the following aspects:

[0052] 1. Monocular device parameter calibration, mainly calibrating the parameter relationship between the device's intrinsic parameters, distortion coefficients and depth, to obtain the change parameters from pixel coordinates to point cloud model.

[0053] 2. Projection module 1 calibration, the projection module 1 also meets the imaging principle, so it also has intrinsic parameters and distortion coefficients that need to be calibrated.

[0054] 3. Grating sheet 10 calibration, the grating sheet 10 requires that the distance between all debruijn line centers must be the same when designed, but due to the limitations of photolithography and other processes, the accuracy error is about ±2um, after projection magnification, the error is ±50um (at 40cm magnification 25 times), which is already very large, so it needs to be corrected.

[0055] 4. Binocular device calibration, binocular calibration is relatively simple, without considering the distortion of the projection module 1, the debruijn sequence points are directly decoded as feature points, and then binocular calibration is performed.

[0056] The working principle of the present application will be described below.

[0057] First, the grating piece 10 based on the debruijn coding mode is assembled to form a grating fringe sequence. The control module 3 outputs a projection control signal to control the projection module 1 to project. The MCU control module on the control board 13 of the projection module 1 controls the LED array 15 on the projection module 1 to work according to the LED control signal output by the LED interface. If it is a color fringe grating scheme, one white LED lamp is used. If it is an infrared grating scheme, one 3W 850nm infrared LED lamp and two 3W 940nm infrared LED lamps are used, and the infrared LED lamps are arranged in a character shape. Then, the light output by the LED lamps can project a grating pattern with a DeBruijin sequence on the object to be measured after passing through the grating piece 10.

[0058] The control module 3 outputs a shooting control signal to control the camera module 2 to shoot the current image, and acquires a point cloud image according to the image, and then models according to the point cloud image. Different gratings, monocular devices or binocular devices have different methods for acquiring point cloud images. The process of forming a point cloud image for a monocular device is as follows:

[0059] 1. For a color grating, two images (a grating projection image (white LED is on) and a natural light image (LED is off)) are collected (for an object with a single color, only one image needs to be collected, such as face modeling). The debruijn sequence image is obtained by subtracting the natural light image from the grating image. The debruijn sequence image is corrected using the camera intrinsic parameters, the center points of the lines are extracted using the Steger algorithm, the feature points are matched by color calculation, and the ideal sequence positions corresponding to the feature points are determined. Then, using the eight calibration parameters, the grating process error is compensated, and the projection light machine distortion is compensated, and finally the world coordinates of the pixel coordinates are calculated to obtain the object point cloud image.

[0060] 2. For an infrared grating, two images are also collected, one is an 850nm image and the other is a 940nm image. The 850nm infrared image is marked as green, the 940nm infrared image is marked as blue, and the lines imaged by 850nm and 940nm are marked as cyan. The subsequent steps of forming a point cloud image are basically the same as the foregoing, which are not repeated here.

[0061] The method of forming a point cloud image by a binocular device is relatively simple, which directly decodes the debruijn sequence as the only feature point, and then uses binocular modeling.

[0062] The technical scheme of the present application has the following technical effects:

[0063] 1. The structure is simple, the price is cheap, and it is beneficial to small-batch three-dimensional modeling devices.

[0064] 2. Overcome the micro-motor motion of DLP and MEMS mirror and other small inconsistency problem, make the repeat accuracy is very high.

[0065] 3. Fully meet the application of industrial manufacturing, medical beauty, cultural relic protection and other fields.

[0066] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the exemplary description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0067] Although the embodiments of the present application have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and purposes of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. A structured light three-dimensional modeling device, comprising: The application relates to a structured light three-dimensional modeling device. The device comprises a projection module, a camera module and a control module. The projection module is used for projecting a grating pattern formed based on a DeBruijin coding mode to the surface of an object to be measured, and comprises an emitting unit and a grating sheet. The grating sheet is provided with a grating stripe sequence formed based on the DeBruijin coding mode.

2. The structured light three-dimensional modeling device of claim 1, wherein, The emitting unit emits light to form the preset grating pattern after the light passes through the grating stripe sequence of the grating sheet.

3. The structured light three-dimensional modeling device of claim 2, wherein, The camera module is used for acquiring a projection image after the grating pattern is projected to the object to be measured by the projection module.

4. The structured light three-dimensional modeling device of claim 1, wherein, The control module is connected to and controls the projection module and the camera module.

5. The structured light three-dimensional modeling device of claim 1, wherein, The control module is used for establishing a three-dimensional model of the object to be measured according to the projection image acquired by the camera module. The grating sheet is a black substrate.

6. The structured light three-dimensional modeling device of claim 1, wherein, The grating stripe sequence comprises a plurality of stripes vertically and equidistantly arranged on the black substrate.

7. The structured light three-dimensional modeling device of claim 1, wherein, The stripes are arranged in the DeBruijin coding mode.

8. The structured light three-dimensional modeling device of claim 5, wherein, The stripes have the same line width and are at least one of green, blue and cyan in color.

9. The structured light three-dimensional modeling device of claim 5, wherein, The grating stripe sequence further comprises a calibration stripe transversely arranged on the grating sheet.

10. The structured light three-dimensional modeling device of claim 1, wherein, The calibration stripe is at least one of green, blue and cyan in color. The camera module comprises a monocular camera or a binocular camera. The emitting unit comprises a shell, a heat sink, a control board, a cover plate, an LED array, a condenser lens, a collimating lens, a right-angle prism and a projection lens. The LED array is arranged on one side of the control board. The heat sink is arranged on the other side of the control board. The condenser lens, the collimating lens, the right-angle prism and the projection lens are fixed in the shell and are sequentially arranged on one side of the LED array in the light emission direction. The structured light three-dimensional modeling device further comprises a bracket for fixing the projection module and the camera module. The structured light three-dimensional modeling device further comprises a heat dissipation module connected to the projection module and the camera module. The control board comprises a power module, an MCU control module and an LED interface and switch module. The power module is connected to the MCU control module and the LED interface and switch module. The MCU control module is connected to the LED interface and switch module. The LED interface and switch module is connected to the LED array. The LED array comprises a white light LED lamp or three infrared LED lamps arranged in a triangular shape. The camera module is a 200W camera module.

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