A three-dimensional measuring device and a measuring method

Abstract

The application discloses a kind of three-dimensional measuring device and method, which includes at least one projection device for emitting structured light stripe;Rotary reflection module includes at least one first mirror and one second mirror;First mirror is used to reflect structured light stripe to the surface of object to be measured;Second mirror is used to reflect the deformed stripe reflected to the surface of object to be measured;First mirror and second mirror rotate along the rotation axis;At least one imaging device is used to receive the deformed stripe reflected by second mirror;The reflecting surface of at least one of first mirror and second mirror includes at least non-coplanar first reflecting surface and second reflecting surface;First reflecting surface is located on the side of second reflecting surface away from projection device;First reflecting surface is deflected towards the side away from reflecting surface, and second reflecting surface is deflected towards the side towards reflecting surface.The technical scheme of the application improves the accuracy of measuring convex object to be measured, and reduces the measurement cost.

Description

Technical Field

[0001] This invention relates to the field of three-dimensional measurement technology, and in particular to a three-dimensional measurement device and measurement method. Background Technology

[0002] Optical 3D imaging technology has extremely wide applications due to its advantages such as fast data acquisition speed and high measurement accuracy. For 3D measurement of convex parts such as hatches and panels, the main methods used are 3D photography based on mobile robot platforms or handheld 3D cameras with transfer stations. However, the former requires high-precision multi-axis robots, resulting in high costs, while the latter requires image stitching, which introduces cumulative errors.

[0003] Currently, there is a synchronous scanning 3D imaging device based on structured light projection, whose scanning trajectory is "concave cylindrical", which is exactly the opposite of the surface of convex parts. It cannot measure the surface geometry data of convex or elongated parts within the optimal effective field of view. Summary of the Invention

[0004] This invention provides a three-dimensional measuring device and method to overcome the shortcomings of the prior art, improve the accuracy of measuring convex objects, and reduce the measurement cost.

[0005] In a first aspect, the present invention provides a three-dimensional measuring device, comprising:

[0006] At least one projection device for emitting structured light stripes;

[0007] A rotating reflection module includes at least one first reflector and one second reflector; the first reflector is used to reflect the structured light stripes onto the surface of the object to be tested; the second reflector is used to reflect the deformed stripes reflected from the surface of the object to be tested; the first reflector and the second reflector rotate along a rotation axis that is parallel to the reflecting surfaces of both the first reflector and the second reflector.

[0008] At least one imaging device is used to receive the deformed fringes reflected by the second mirror;

[0009] The reflecting surface of at least one of the first reflector and the second reflector includes at least a first reflecting surface and a second reflecting surface that are not coplanar; the first reflecting surface is located on the side of the second reflecting surface away from the projection device; the first reflecting surface is deflected toward the side away from the reflecting surface, and the second reflecting surface is deflected toward the side of the reflecting surface.

[0010] Optionally, the first reflective surface and the second reflective surface are planar.

[0011] Optionally, the angle between the first reflective surface and the second reflective surface and the rotation axis is both in the range of 0 to 15°.

[0012] Optionally, the first reflective surface and the second reflective surface are arc-shaped.

[0013] Optionally, the structured light stripes emitted by the projection device include at least one of red, green, and blue-violet.

[0014] Optionally, the rotary reflection module further includes a motor and a motor driver;

[0015] The motor driver is used to drive the motor to rotate the first reflector and the second reflector along the rotation axis.

[0016] Optionally, the three-dimensional measuring device further includes: a synchronization signal driver;

[0017] The synchronization signal driver is electrically connected to both the projection device and the imaging device, and is used to control the projection device and the imaging device to work synchronously.

[0018] Optionally, the three-dimensional measuring device further includes a signal processing module for determining the surface shape of the object to be measured based on the structured light stripes emitted by the projection device and the deformed stripes received by the imaging device.

[0019] Secondly, the present invention provides a measurement method based on the three-dimensional measuring device described in any one of the above claims, comprising:

[0020] S10. When the reflective surface of the second reflector is at a preset deflection angle, the projection device projects the structured light stripes onto the surface of the object to be measured through the first reflector. At the same time, the imaging device receives the deformed stripes on the surface of the object to be measured through the second reflector. The preset deflection angle is 0 to 90°.

[0021] S20. Determine the three-dimensional coordinates of the spatial points of the object under test based on the structured light stripes emitted by the projection device and the deformed stripes received by the imaging device.

[0022] S30. Adjust the preset deflection angle, drive the first reflector and the second reflector to rotate to the adjusted preset deflection angle, and return to execute S10 to S20 until the preset deflection angle reaches the preset condition.

[0023] Optionally, the three-dimensional coordinates of the spatial points of the object under test are determined based on the structured light fringes emitted by the projection device and the deformed fringes received by the imaging device, including:

[0024] By establishing the correspondence between points on the center line of the deformed stripes in the two-dimensional image, and using triangulation, the three-dimensional coordinate values ​​of the mirror point of the spatial object point are obtained.

[0025] The three-dimensional coordinates of the spatial point are obtained by mirroring the object.

[0026] The technical solution of this invention involves projecting structured light stripes through a projection device. A first reflecting mirror reflects these stripes onto the surface of the object under test. The deformed stripes reflected from the surface of the object are then reflected by a second reflecting mirror and received by an imaging device, thereby achieving three-dimensional measurement of the object. Simultaneously, at least one of the first and second reflecting mirrors includes at least two non-coplanar reflecting surfaces. The first reflecting surface is located on the side of the second reflecting surface away from the projection device. The first reflecting surface is deflected towards the side away from the reflecting surface, while the second reflecting surface is deflected towards the reflecting surface. This alters the scanning trajectory of the rotating light path, making the scanning trajectory of the three-dimensional measurement device similar to the surface shape of the object under test. This allows for the measurement of the three-dimensional data of the object within the optimal effective field of view of the three-dimensional measurement device, improving the accuracy of measuring convex objects and reducing measurement costs.

[0027] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of a 3D scanning device in the prior art;

[0030] Figure 2 This is a schematic diagram of the simulation results of the three-dimensional scanning trajectory in the existing technology;

[0031] Figures 3-5 These are schematic diagrams of the structures of three three-dimensional scanning devices provided in embodiments of the present invention;

[0032] Figure 6 This is a schematic diagram of the simulated scanning trajectory of a three-dimensional measuring device provided in an embodiment of the present invention;

[0033] Figure 7 This is a schematic diagram of the three-dimensional measuring device when the deflection angle of the rotating reflection module is 30°.

[0034] Figure 8 This is a schematic diagram of the three-dimensional measuring device when the deflection angle of the rotating reflection module is 45°.

[0035] Figure 9 This is a schematic diagram of the three-dimensional measuring device when the deflection angle of the rotating reflection module is 60°.

[0036] Figures 10-12 Here are structural schematic diagrams of three other three-dimensional measuring devices provided in the embodiments of the present invention;

[0037] Figure 13 This is a schematic diagram of the simulated scanning trajectory of another measuring device provided in an embodiment of the present invention; Figure 14 This is a schematic diagram of the structure of another three-dimensional measuring device provided in an embodiment of the present invention;

[0038] Figure 15 A flowchart of a three-dimensional measurement method provided in an embodiment of the present invention. Detailed Implementation

[0039] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0040] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0041] Figure 1 This is a schematic diagram of a 3D scanning device in the prior art, for reference. Figure 1As shown, the three-dimensional scanning device includes a projection device 01, a rotating plane mirror 02, a motor 03, and an imaging device 04. The structured light stripes emitted by the projection device 01 are reflected by the rotating plane mirror 02 and projected onto a point P on the surface of the object to be measured. The deformed stripes reflected by point P on the surface of the object to be measured are reflected by the rotating plane mirror 02 and received by the imaging device 04. Then, the motor drives the rotating plane mirror to rotate to complete the measurement of the entire surface of the object to be measured. Figure 2 This is a schematic diagram of the simulation results of a three-dimensional scanning trajectory in the existing technology, combined with reference. Figure 1 and Figure 2 As shown, the scanning trajectory of existing 3D scanning devices is "concave cylindrical", which is exactly the opposite of the surface of convex parts. Therefore, it is impossible to measure the surface geometry data of convex or elongated parts within the optimal effective field of view.

[0042] Therefore, the present invention provides a three-dimensional measurement device that emits structured light stripes through a projection device, and a first reflecting mirror reflects the structured light stripes onto the surface of the object to be measured. The deformed stripes reflected from the surface of the object to be measured are then reflected by a second reflecting mirror and received by an imaging device. At least one of the first and second reflecting mirrors has a reflecting surface comprising at least a non-coplanar first reflecting surface and a second reflecting surface. The first reflecting surface is located on the side of the second reflecting surface away from the projection device, and the first reflecting surface is deflected toward the side opposite to the reflecting surface, while the second reflecting surface is deflected toward the reflecting surface. This corrects the scanning trajectory of the rotating light path, making the scanning trajectory of the three-dimensional measurement device similar to the surface shape of the object to be measured. This allows for the measurement of the three-dimensional data of the object to be measured within the optimal effective field of view of the three-dimensional measurement device, improving the accuracy of measuring convex objects and reducing measurement costs.

[0043] Figures 3-5 The following are schematic diagrams of the structures of three three-dimensional scanning devices provided in embodiments of the present invention, with reference to... Figure 3-5 As shown, the three-dimensional scanning device provided in this embodiment of the invention includes: at least one projection device 1, a rotating reflection module 2, and at least one imaging device 3; the projection device 1 is used to emit structured light stripes; the rotating reflection module 2 includes at least one first reflecting mirror 21 and one second reflecting mirror 22; the first reflecting mirror 21 is used to reflect the structured light stripes onto the surface of the object to be measured; the second reflecting mirror 22 is used to reflect the deformed stripes reflected from the surface of the object to be measured; the first reflecting mirror 21 and the second reflecting mirror 22 rotate along a rotation axis that is parallel to the reflecting surfaces of the first reflecting mirror 21 and the second reflecting mirror 22; the imaging device 3 is used to receive the deformed stripes reflected by the second reflecting mirror 22.

[0044] The reflecting surface of at least one of the first reflecting mirror 21 and the second reflecting mirror 22 includes at least a non-coplanar first reflecting surface 211 / 221 and a second reflecting surface 212 / 222; the first reflecting surface 211 / 221 is located on the side of the second reflecting surface 212 / 222 away from the projection device 1; the first reflecting surface 211 / 221 is deflected toward the side away from the reflecting surface, and the second reflecting surface 212 / 222 is deflected toward the side of the reflecting surface.

[0045] The projection device 1 may include, but is not limited to, a laser array or a projector. For example, when the projection device 1 includes a laser array, a 1mW point laser source can be used, with an average laser width of 2mm. The projection method can employ any existing two-dimensional structured light projection technology with encoded information, such as grating projection, Fourier projection, or color structured light projection. When using Fourier projection, phase and triangulation methods can be integrated simultaneously to calculate spatial three-dimensional data. The structured light stripes can be longitudinal structured light stripes. In this embodiment, a projection device 1 may be included, for example... Figure 3 and Figure 5 As shown; it may also include multiple projection devices 1, for example Figure 4 The embodiment shown includes two projection devices 1. Any device that can achieve the core inventive point of this embodiment is acceptable. The present invention does not impose a specific limit on the number of projection devices 1.

[0046] Imaging device 3 can employ any existing two-dimensional area array imaging technology, such as a two-dimensional CCD camera or other general imaging devices. In this embodiment, it may include one imaging device 3, for example... Figure 3 and Figure 4 As shown; multiple imaging devices 3 can also be set, for example Figure 5 The illustrated embodiment includes two imaging devices 3. The positions of the multiple imaging devices 3 can be set as needed, as long as the core inventive point of this embodiment can be achieved. This embodiment of the invention does not impose specific limitations on this.

[0047] The object under test is a convex object or a long strip-shaped object. Within the depth of field of the three-dimensional imaging, the structured light stripes emitted by the projection device 1 are reflected sequentially by the first reflecting mirror 21, the object under test, and the second reflecting mirror 22, covering the receiving light path of the imaging device 3.

[0048] Specifically, within the depth of field of 3D imaging, the structured light stripes emitted by the projection device 1 are reflected by the first reflecting mirror 21 and projected onto a point P on the surface of the object to be measured. After being reflected by point P on the surface of the object to be measured, the structured light stripes generate structured light deformation stripes. These structured light deformation stripes propagate to the second reflecting mirror 22 and are reflected by the second reflecting mirror 22 to the imaging device 3. Thus, the imaging device 3 can measure the surface of the object to be measured based on the structured light stripes and the deformation stripes.

[0049] It is understood that the reflecting surface of at least one of the first reflecting mirror 21 and the second reflecting mirror 22 includes at least a first reflecting surface 211 / 221 and a second reflecting surface 212 / 222. The first reflecting surface 211 / 221 is located on the side of the second reflecting surface 212 / 222 away from the projection device 1, and the first reflecting surface 211 / 221 is deflected toward the side away from the reflecting surface, while the second reflecting surface 212 / 222 is deflected toward the reflecting surface. That is, at least one of the first reflecting mirror 21 and the second reflecting mirror 22 is a correction mirror. In an exemplary embodiment, reference is made to... Figure 3 As shown, when the first reflector is a correction mirror, when the first reflector 21 and the second reflector 22 rotate along the rotation axis, the structured light stripes emitted by the projection device 1 will be projected onto different positions of the first reflector 21. When the first reflector 21 and the second reflector 22 rotate along the rotation axis to a certain position, the structured light stripes can be projected onto the first reflecting surface 211 of the first reflector 21, and after being reflected by the first reflecting surface 211, they are projected onto the surface of the object to be measured. When the first reflector 21 and the second reflector 22 rotate along the rotation axis to another position, the structured light stripes can be projected onto the second reflecting surface 212 of the first reflector 21, and after being reflected by the second reflecting surface 212, they are projected onto the surface of the object to be measured. In this way, the scanning trajectory of the rotating light path can be changed, so that the scanning trajectory of the three-dimensional measuring device is similar to the surface shape of the object to be measured.

[0050] In this embodiment, structured light stripes are emitted by a projection device, and a first reflecting mirror reflects the structured light stripes onto the surface of the object to be measured. The deformed stripes reflected from the surface of the object to be measured are then reflected by a second reflecting mirror and received by an imaging device. At least one of the first and second reflecting mirrors has a reflecting surface that is not coplanar. The first reflecting surface is located on the side of the second reflecting surface away from the projection device. The first reflecting surface is deflected toward the side away from the reflecting surface, and the second reflecting surface is deflected toward the reflecting surface. This corrects the scanning trajectory of the rotating light path, making the scanning trajectory of the three-dimensional measuring device similar to the surface shape of the object to be measured. This allows the three-dimensional data of the object to be measured to be measured within the optimal effective field of view of the three-dimensional measuring device, improving the accuracy of measuring convex objects and reducing measurement costs.

[0051] In an alternative embodiment, Figure 6This is a schematic diagram of the simulated scanning trajectory of a three-dimensional measuring device provided in an embodiment of the present invention, in conjunction with reference. Figures 3-6 As shown, the first reflecting surface 211 / 221 and the second reflecting surface 212 / 222 are planar. The first or second reflecting mirror 21 may further include a third reflecting surface 213 / 223. The third reflecting surface 213 / 223 is coplanar with the rotation axis. The two ends of the third reflecting surface 213 / 223 are respectively connected to one end of the first reflecting surface 211 / 221 and one end of the second reflecting surface 212 / 222. The angle between the first reflecting surface 211 / 221 and the second reflecting surface 212 / 222 and the rotation axis is in the range of 0 to 15°. In this embodiment, the rotation axis is located in the plane containing the reflecting surface of the second reflecting mirror 22, and the first and second reflecting mirrors 21 and 22 rotate along the rotation axis. In an exemplary embodiment, the angle between the first reflecting surface 211 / 221 and the second reflecting surface 212 / 222 and the rotation axis is 10°. (Refer to...) Figure 6 It can be seen that when the angle between the first reflecting surface 211 / 221 and the second reflecting surface 212 / 222 and the rotation axis is 10°, the scanning trajectory of the three-dimensional measuring device is 3 segments of "convex cylindrical shape".

[0052] Understandably, the smaller the angle between the first reflecting surface 211 and the second reflecting surface 212 and the second reflecting mirror 22, the closer the scanning trajectory of the three-dimensional measuring device is to the scanning trajectory of a three-dimensional measuring device using a rotating plane mirror. Conversely, the larger the angle between the first reflecting surface 211 and the second reflecting surface 212 and the reflecting surface, the farther the distance of the three-segment "convex cylindrical" scanning trajectory of the three-dimensional measuring device is, making it more suitable for measuring more convex objects. Therefore, the angle between the first reflecting surface 211 and the second reflecting surface 212 and the reflecting surface can be set according to the surface shape of the object to be measured, so that the scanning trajectory of the three-dimensional measuring device is closer to the surface shape of the object to be measured. When the angle between the first reflecting surface 211 and the second reflecting surface 212 and the reflecting surface is greater than or equal to 15°, the deformed fringes reflected from the surface of the object to be measured will not be received by the imaging device 3 after being reflected by the second reflecting mirror 22, thus making it impossible to achieve three-dimensional measurement of the object to be measured.

[0053] Figure 7 This is a schematic diagram of the three-dimensional measurement device when the deflection angle of the rotating reflection module is 30°. Figure 8 This is a schematic diagram of the three-dimensional measurement device when the deflection angle of the rotating reflection module is 45°. Figure 9 This is a schematic diagram of the 3D measurement device when the deflection angle of the rotating reflection module is 60°. For details, please refer to... Figures 7-9As shown, when the deflection angle of the rotating reflection module 2 is 30°, the structured light stripes emitted by the projection device 1 are reflected by the second reflecting surface 212; when the deflection angle of the rotating reflection module 2 is 45°, the structured light stripes emitted by the projection device 1 are reflected by the third reflecting surface 213; when the deflection angle of the rotating reflection module 2 is 60°, the structured light stripes emitted by the projection device 1 are reflected by the first reflecting surface 2111. Thus, during the rotation of the rotating reflection module 2 along the rotation axis, the structured light stripes emitted by the projection device 1 are reflected by different positions of the first reflecting mirror 21, changing the path of the light path. This changes the scanning trajectory of the rotating light path, making the scanning trajectory of the three-dimensional measuring device "convex cylindrical", thus improving the measurement accuracy of the three-dimensional measuring device for convex objects.

[0054] In another alternative embodiment, Figures 10-12 These are schematic diagrams of three other three-dimensional measuring devices provided in embodiments of the present invention. Figure 13 This is a schematic diagram of a simulated scanning trajectory of another measuring device provided in an embodiment of the present invention. (Refer to reference...) Figures 10-13 As shown, the first reflecting surface 211 / 221 and the second reflecting surface 212 / 222 are arc-shaped. When the first reflecting mirror 21 and the second reflecting mirror 22 rotate along the rotation axis, the scanning trajectory of the three-dimensional measuring device is a continuous "convex cylindrical" trajectory, which can more closely approximate the surface shape of the object to be measured. It can be understood that when the arc of the first reflecting surface 211 / 221 and the second reflecting surface 212 / 222 has different arcs, their scanning trajectories are different continuous "convex cylindrical" trajectories. Therefore, the arc of the first reflecting surface 211 / 221 and the second reflecting surface 212 / 222 can be designed according to the morphology of the surface of the object to be measured, so that the scanning trajectory of the three-dimensional measuring device is consistent with the morphology of the surface of the object to be measured, thereby further improving the measurement accuracy of the three-dimensional measuring device.

[0055] Optionally, the structured light stripes emitted by the projection device 1 include at least one of red, green, and blue.

[0056] Understandably, when the object under test is a large depth-of-field object, two or more structured light fringes emitted by the projection device 1 are projected onto different points on the surface of the object under test. After being reflected by the object under test, the resulting deformed fringes may overlap and become a single deformed fringe. In this case, it is impossible to determine the three-dimensional data of the surface of the object under test based on the structured light fringes emitted by the area array projection and the deformed fringes received by the imaging device 3. However, when the structured light fringes include any two or more of red, green, and blue, if two or more structured light fringes emitted by the projection device 1 are projected onto different points on the surface of the object under test and are reflected by the object under test, the resulting deformed fringes may overlap and become a single deformed fringe. In this case, the composition of the deformed fringes can be analyzed, and the three-dimensional data of the surface of the object under test can be determined through the structured light fringes and the deformed fringes. This improves the image recognition of the surface of the object under test and prevents the phenomenon of structured light overlap when measuring large depth-of-field objects, thereby improving the accuracy of measurement data acquisition.

[0057] It should be noted that when the measurement accuracy requirement of the 3D measuring device is low, such as when real-time detection of whether the surface shape of the object to be measured meets the requirements in a production line, the structured light emitted by the projection device 1 can be one of red structured light stripes, green structured light stripes, or blue-violet structured light stripes to save costs. When the measurement accuracy requirement of the 3D measuring device is high, or when the surface color of the object to be measured is dark, the structured light emitted by the projection device 1 can include any two or three of red structured light stripes, green structured light stripes, and blue structured light stripes, thus improving the accuracy of measurement data acquisition.

[0058] Optional, Figure 14 This is a schematic diagram of the structure of another three-dimensional measuring device provided in an embodiment of the present invention, with reference to... Figure 14 As shown, the rotating reflection module 2 also includes a motor 4 and a motor driver 5; the motor driver 5 is used to drive the motor 4 to rotate the first reflector 21 and the second reflector 22 along the rotation axis to change the projection light path and the receiving light path, thereby realizing the scanning of each point on the surface of the object to be measured.

[0059] In an exemplary embodiment, the three-dimensional measuring device may further include a motor control circuit (not shown in the figure), which can be designed using an ATM89C2051 microcontroller. The signal emitted by the motor control circuit drives the motor 4 to rotate the first reflector 21 and the second reflector 22 via the motor driver 5. The motor driver 5 can be a stepper motor driver with microstepping control, which can control the motor's speed, number of steps, and direction. Specifically, it can be an SH-20503 stepper motor driver. The motor 4 can be a stepper motor. For example, the stepper motor can be a 2-phase hybrid magnetic stepper motor of model PH266L-03-A4 from ORIENTAL MOTOR Corporation of Japan, with a step angle of 1.80° and a reduction ratio of 1:50 from its built-in gearbox.

[0060] It is understandable that when the motor driver 5 drives the motor 4 to rotate the first reflector 21 and the second reflector 22 along the rotation axis, the change in the angle of the first reflector 21 and the second reflector 22 causes the structured light stripes emitted by the projection device 1 to be projected onto different positions of the reflective surface of the first reflector 21, such as onto the first reflective surface 211 or the second reflective surface 212, thereby changing the projection trajectory of the three-dimensional measurement device.

[0061] Optional, continue to refer to Figure 14 As shown, the three-dimensional measuring device provided in this embodiment also includes: a synchronization signal driver 6; the synchronization signal driver 6 is electrically connected to the projection device 1 and the imaging device 3 respectively, and is used to control the projection device 1 and the imaging device 3 to work synchronously.

[0062] Among them, the synchronization signal driver 6 sends out external synchronization information to control the projection device 1 and the imaging device 3 to work synchronously, so that the structured light stripes emitted by the projection device 1 and the deformed stripes received by the imaging device 3 can be identified and calculated to realize the three-dimensional measurement of the three-dimensional measuring device.

[0063] Optional, continue to refer to Figure 14 As shown, the three-dimensional measurement device provided in this embodiment also includes a signal processing module 7, which is used to determine the surface shape of the object to be measured based on the structured light stripes emitted by the projection device 1 and the deformed stripes received by the imaging device 3.

[0064] The signal processing module 7 may include, but is not limited to, a computer. For example, based on the structured light stripes emitted by the projection device 1 and the deformed stripes received by the imaging device 3, the surface shape of the object under test can be determined. A two-dimensional image can be established based on the structured light stripes emitted by the projection device 1 and the deformed stripes received by the imaging device 3. Using the correspondence between points on the center line of the deformed stripes in the two-dimensional image, triangulation is performed to obtain the three-dimensional coordinates of the mirror point P' of point P on the surface of the object under test in the first reflecting mirror 21. Thus, the three-dimensional coordinates of point P on the surface of the object under test are determined through the mirror relationship.

[0065] Based on the same concept, this embodiment of the invention also provides a three-dimensional measurement method, which is based on the three-dimensional measurement device provided in this embodiment. Figure 15 A flowchart of the three-dimensional measurement method provided in the embodiments of the present invention is shown below. Figure 15 As shown, the three-dimensional measurement method includes:

[0066] S10. When the reflective surface of the second reflector is at a preset deflection angle, the projection device projects structured light stripes onto the surface of the object to be measured through the first reflector. At the same time, the imaging device receives the deformed stripes on the surface of the object to be measured through the second reflector. The preset deflection angle ranges from 0 to 90°.

[0067] The preset deflection angle is the angle between the second reflector and the first direction, where the first direction is the direction in which the first reflector points to the object to be measured.

[0068] S20. Determine the three-dimensional coordinates of the spatial points of the object to be measured based on the structured light fringes emitted by the projection device and the deformed fringes received by the imaging device.

[0069] In one exemplary embodiment, the structured light stripes emitted by the projection device and the deformed stripes received by the imaging device can be compared, and the three-dimensional coordinates of the spatial points of the object under test can be determined by analyzing the differences between the structural information of the structured light stripes and the deformed stripes.

[0070] In one optional embodiment, determining the three-dimensional coordinates of a spatial point of the object under test based on the structured light stripes emitted by the projection device and the deformed stripes received by the imaging device may specifically include: establishing a correspondence between points on the center line of the deformed stripes on the two-dimensional image, and using triangulation to obtain the three-dimensional coordinates of the mirror point of the spatial point; and obtaining the three-dimensional coordinates of the spatial point through the mirror relationship.

[0071] For example, the surface shape of the object under test can be determined based on the structured light stripes emitted by the projection device and the deformed stripes received by the imaging device. Specifically, a two-dimensional image can be established based on the structured light stripes emitted by the projection device and the deformed stripes received by the imaging device. By utilizing the correspondence between points on the center line of the deformed stripes in the two-dimensional image, the three-dimensional coordinates of the mirror point P' of point P on the surface of the object under test in the first reflecting mirror can be obtained through triangulation. Thus, the three-dimensional coordinates of point P on the surface of the object under test can be determined through the mirror relationship.

[0072] S30. Adjust the preset deflection angle, drive the first and second reflectors to rotate to the adjusted preset deflection angle, and return to execute S10 to S20 until the preset deflection angle reaches the preset condition.

[0073] In one optional embodiment, the preset condition can be that the preset deflection angle is gradually adjusted from 0° to 90°, or gradually adjusted from 90° to 0°. In another optional embodiment, the preset condition can be that when the preset deflection angle is adjusted several times in a row, the imaging device 3 cannot receive the deformed stripes. For example, when the preset deflection angle is adjusted 5 times in a row and the imaging device 3 cannot receive the deformed stripes, the preset deflection angle is no longer adjusted.

[0074] Specifically, when the 3D measuring device performs measurements, the object to be measured is placed within the depth of field of the 3D measuring device. When the reflective surface of the second reflector is at a preset deflection angle, the structured light stripes emitted by the projection device are reflected by the first reflector and projected onto a point P on the surface of the object to be measured. After the structured light stripes are reflected by the surface of the object to be measured, structured light deformation stripes are generated. The second reflector reflects the structured light deformation stripes to the imaging device, and the imaging device receives the deformation stripes. The signal processing module obtains the structured light stripes emitted by the projection device and the deformation stripes received by the imaging device, and establishes a two-dimensional image based on the structured light stripes and deformation stripes. By using the correspondence between the points on the center line of the deformation stripes in the two-dimensional image, the three-dimensional coordinates of the mirror point P' of point P on the surface of the object to be measured in the first reflector are obtained through triangulation. Thus, the three-dimensional coordinates of point P on the surface of the object to be measured are determined through the mirror relationship. Then, the preset angle is adjusted. The motor driver drives the motor to rotate the first and second reflectors along the rotation axis to the adjusted preset angle. The signal processing module obtains the structured light stripes emitted by the projection device and the deformed stripes received by the imaging device after the preset angle is adjusted. Based on the structured light stripes and deformed stripes after the preset angle is adjusted, a two-dimensional image is established. Using the correspondence between the points on the center line of the deformed stripes in the two-dimensional image, the three-dimensional coordinates of the mirror point P' of the surface P of the object to be measured in the first reflector are obtained through triangulation. Thus, the three-dimensional coordinates of the surface P of the object to be measured are determined through the mirror relationship. The above steps are repeated until the preset deflection angle reaches the preset condition. In this way, the three-dimensional measurement of the object to be measured is completed.

[0075] In this embodiment, when the reflective surface of the second reflector is at a preset deflection angle, the projection device projects the structured light stripes onto the surface of the object under test through the first reflector. Simultaneously, the imaging device receives the deformed stripes on the surface of the object under test through the second reflector. Based on the structured light stripes emitted by the projection device and the deformed stripes received by the imaging device, the three-dimensional coordinates of the spatial points of the object under test are determined. By adjusting the preset deflection angle and repeating the above steps until the measurement of the object under test is completed at all preset deflection angles, the scanning trajectory of the rotating light path is corrected when the reflective surface of the first reflector includes both the first and second reflective surfaces. This makes the scanning trajectory of the three-dimensional measuring device similar to the surface shape of the object under test, thereby measuring the three-dimensional data of the object under test within the optimal effective field of view of the three-dimensional measuring device. This improves the accuracy of measuring convex objects under test and reduces the measurement cost.

[0076] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A three-dimensional measuring device, characterized in that, include: At least one projection device for emitting structured light stripes; A rotating reflective module includes at least one first reflector and one second reflector; The first reflector is used to reflect the structured light stripes onto the surface of the object under test; the second reflector is used to reflect the deformed stripes reflected from the surface of the object under test. The first reflector and the second reflector rotate along a rotation axis that is parallel to the reflecting surfaces of both the first reflector and the second reflector. At least one imaging device is used to receive the distorted fringes reflected by the second mirror; The reflecting surface of at least one of the first reflector and the second reflector includes at least a first reflecting surface and a second reflecting surface that are not coplanar; the first reflecting surface is located on the side of the second reflecting surface away from the projection device; the first reflecting surface is deflected toward the side away from the reflecting surface, and the second reflecting surface is deflected toward the side of the reflecting surface.

2. The three-dimensional measuring device according to claim 1, characterized in that, The first reflective surface and the second reflective surface are planar.

3. The three-dimensional measuring device according to claim 2, characterized in that, The angles between the first and second reflecting surfaces and the rotation axis are both in the range of 0 to 15°.

4. The three-dimensional measuring device according to claim 1, characterized in that, The first reflective surface and the second reflective surface are arc-shaped.

5. The three-dimensional measuring device according to claim 1, characterized in that, The structured light stripes emitted by the projection device include at least one of red, green, and blue.

6. The three-dimensional measuring device according to claim 1, characterized in that, The rotary reflection module also includes a motor and a motor driver; The motor driver is used to drive the motor to rotate the first reflector and the second reflector along the rotation axis.

7. The three-dimensional measuring device according to claim 1, characterized in that, Also includes: Synchronization signal driver; The synchronization signal driver is electrically connected to both the projection device and the imaging device, and is used to control the projection device and the imaging device to work synchronously.

8. The three-dimensional measuring device according to claim 1, characterized in that, Also includes: The signal processing module is used to determine the surface shape of the object under test based on the structured light stripes emitted by the projection device and the deformed stripes received by the imaging device.

9. A measurement method based on the three-dimensional measuring device according to any one of claims 1-8, characterized in that, include: S10. When the reflective surface of the second reflector is at a preset deflection angle, the projection device projects the structured light stripes onto the surface of the object to be measured through the first reflector. At the same time, the imaging device receives the deformed stripes on the surface of the object to be measured through the second reflector. The preset deflection angle ranges from 0 to 90°; S20. Determine the three-dimensional coordinates of the spatial points of the object under test based on the structured light stripes emitted by the projection device and the deformed stripes received by the imaging device. S30. Adjust the preset deflection angle, drive the first reflector and the second reflector to rotate to the adjusted preset deflection angle, and return to execute S10 to S20 until the preset deflection angle reaches the preset condition.

10. The measurement method according to claim 9, characterized in that, The three-dimensional coordinates of points on the surface of the object under test are determined based on the structured light fringes emitted by the projection device and the deformed fringes received by the imaging device, including: By establishing the correspondence between points on the center line of the deformed stripes in the two-dimensional image, and using triangulation, the three-dimensional coordinate values ​​of the mirror points of the points on the surface of the object under test are obtained. The three-dimensional coordinates of points on the surface of the object under test are obtained by mirroring the image.

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