Method, system and device for determining scanning mirror surface type

Abstract

The invention discloses a method, a system and a device for determining a scanning mirror surface type, and relates to the technical field of space laser communication. When a scanning mirror moves at a high speed, laser emitted by a laser source is received, and the laser is reflected to a light sensing surface of a camera; in the exposure duration of the camera, recording each movement track of the laser reflected to the light-sensitive surface of the camera, and determining a light spot shape corresponding to each movement track in the high-speed movement process of the scanning mirror; and determining a surface type value corresponding to the scanning mirror based on a preset corresponding relationship between the standard light spot shape and the surface type value and the light spot shape corresponding to each movement track. According to the method, the light spot shapes corresponding to the motion trails of the lasers reflected at different positions of the scanning mirror when the scanning mirror moves at a high speed are recorded, then the surface type value corresponding to the scanning mirror is accurately obtained according to the corresponding relation between the standard light spot shape and the surface type value, and the measurement accuracy of the surface type of the scanning mirror is effectively improved.

Description

Technical Field

[0001] The present application relates to the field of space laser communication technology, and in particular to a method, system and device for determining a scanning mirror type. Background Art

[0002] With the development of satellite Internet technology, scanning mirrors are used in satellite laser communications to reflect light beams to achieve the purpose of imaging.

[0003] However, when the scanning mirror is used in different environments, the surface shape of the scanning mirror will change due to the influence of ambient temperature and solar radiation, affecting the imaging quality. Therefore, it is necessary to measure the surface shape of the scanning mirror to detect whether the surface shape of the scanning mirror has changed.

[0004] In the related art, the measurement of scanning mirror type currently adopts the interference method. The traditional interference method uses phase shift to collect time series images for interference measurement, which has poor real-time performance and is difficult to perform dynamic measurement. The interference measurement method adopts a dedicated optical mechanism design and uses interference fringes for measurement. The shape of the measured surface is measured by the three-dimensional Fourier transform relationship between the frequency of the light wave and the distance. The principle of the two-dimensional cross-section of the three-dimensional Fourier transform of the light field on the detection plane relative to the object is used to measure the light spot using a CCD (Charge Coupled Device), and the single frames are added together to form a three-dimensional data. A three-dimensional Fourier transform is applied to this data to obtain a three-dimensional shape of the measured surface.

[0005] Therefore, the traditional scanning mirror interferometric measurement method uses a large number of devices and a complex structure of the measurement system, so that the measurement accuracy of the scanning mirror type is affected by the accuracy of multiple devices, resulting in low measurement accuracy. Summary of the Invention

[0006] The present application provides a method, system and device for determining a scanning mirror profile, which are used to solve the problem of low measurement accuracy when measuring the scanning mirror profile using traditional interferometric measurement methods.

[0007] In a first aspect, an embodiment of the present application provides a method for determining a scanning mirror type, the method comprising:

[0008] When the scanning mirror moves at high speed, it receives the laser emitted by the laser source;

[0009] reflecting the laser light onto a photosensitive surface of a camera;

[0010] During the exposure time of the camera, the motion trajectories of the laser reflected onto the photosensitive surface of the camera are recorded, and the light spot shapes corresponding to the motion trajectories during the high-speed motion of the scanning mirror are determined;

[0011] The surface shape value corresponding to the scanning mirror is determined based on the correspondence between the preset standard spot shape and the surface shape value, and the spot shape corresponding to each motion trajectory.

[0012] In one or more embodiments, recording the motion trajectories of the laser reflected onto the photosensitive surface of the camera during the exposure time of the camera includes:

[0013] If the laser emitted by the laser source is a pulsed laser, then within the first exposure time of the camera, each movement trajectory of the pulsed laser reflected onto the photosensitive surface of the camera is recorded;

[0014] If the laser light emitted by the laser source is a continuous laser light, then within a plurality of consecutive second exposure times of the camera, each movement trajectory of the continuous laser light reflected onto the photosensitive surface of the camera is recorded;

[0015] The first exposure duration is greater than the second exposure duration.

[0016] In one or more embodiments, determining the surface shape value corresponding to the scanning mirror based on the correspondence between the preset standard spot shape and the surface shape value, and the spot shape corresponding to each motion trajectory, includes:

[0017] If there is only one motion trajectory, the surface shape value corresponding to the spot shape corresponding to the motion trajectory is determined based on the pre-set correspondence between the standard spot shape and the surface shape value; and the surface shape value corresponding to the spot shape corresponding to the motion trajectory is used as the surface shape value corresponding to the scanning mirror;

[0018] If there are multiple motion trajectories, the surface shape values ​​corresponding to the spot shapes corresponding to each motion trajectory are determined based on the pre-set correspondence between the standard spot shape and the surface shape value; the average of the surface shape values ​​corresponding to the spot shapes corresponding to each motion trajectory is used as the surface shape value corresponding to the scanning mirror.

[0019] In one or more embodiments, determining the spot shape corresponding to each motion trajectory during the high-speed motion of the scanning mirror includes:

[0020] For each motion track, perform the following operations:

[0021] Acquire a first light spot shape corresponding to the motion trajectory of the laser reflected onto the photosensitive surface of the camera;

[0022] Performing circle fitting on the first light spot shape using the least squares method to determine the spot radius of the first light spot shape;

[0023] Based on a preset correspondence between a spot radius and a standard spot shape, the standard spot shape corresponding to the spot radius of the first spot shape is used as the spot shape corresponding to the motion trajectory.

[0024] In one or more embodiments, the triggering time of the laser source emitting laser light, the triggering time of the scanning mirror performing high-speed movement, and the triggering time recorded by the camera within the exposure time are the same.

[0025] In one or more embodiments, the method further comprises:

[0026] Before receiving the laser light emitted by the laser source, the laser light emitted by the laser source is converted into planar light.

[0027] In a second aspect, an embodiment of the present application provides a system for determining a scanning mirror type, the system comprising a laser source, a scanning mirror, and a camera, wherein:

[0028] The laser source is used to emit laser light toward the scanning mirror when the scanning mirror moves at high speed;

[0029] The scanning mirror is used to receive the laser light emitted by the laser source when performing high-speed movement, and reflect the laser light to the photosensitive surface of the camera;

[0030] The camera is used to record the various motion trajectories of the laser reflected onto the photosensitive surface of the camera during the exposure time, and determine the spot shape corresponding to each motion trajectory during the high-speed movement of the scanning mirror; based on the correspondence between the pre-set standard spot shape and the surface shape value, and the spot shape corresponding to each motion trajectory, determine the surface shape value corresponding to the scanning mirror.

[0031] In one or more embodiments, if the laser emitted by the laser source is a pulsed laser, the camera is specifically configured to: record, during a first exposure time of the camera, each movement trajectory of the pulsed laser reflected onto the photosensitive surface of the camera;

[0032] If the laser light emitted by the laser source is a continuous laser light, the camera is specifically configured to: record, during a plurality of consecutive second exposure times of the camera, each movement trajectory of the continuous laser light reflected onto the photosensitive surface of the camera;

[0033] The first exposure duration is greater than the second exposure duration.

[0034] In one or more embodiments, the camera is specifically configured to:

[0035] If there is only one motion trajectory, the surface shape value corresponding to the spot shape corresponding to the motion trajectory is determined based on the pre-set correspondence between the standard spot shape and the surface shape value; and the surface shape value corresponding to the spot shape corresponding to the motion trajectory is used as the surface shape value corresponding to the scanning mirror;

[0036] If there are multiple motion trajectories, the surface shape values ​​corresponding to the spot shapes corresponding to each motion trajectory are determined based on the pre-set correspondence between the standard spot shape and the surface shape value; the average of the surface shape values ​​corresponding to the spot shapes corresponding to each motion trajectory is used as the surface shape value corresponding to the scanning mirror.

[0037] In one or more embodiments, the camera is specifically configured to:

[0038] For each motion track, perform the following operations:

[0039] Acquire a first light spot shape corresponding to the motion trajectory of the laser reflected onto the photosensitive surface of the camera;

[0040] Performing circle fitting on the first light spot shape using the least squares method to determine the spot radius of the first light spot shape;

[0041] Based on a preset correspondence between a spot radius and a standard spot shape, the standard spot shape corresponding to the spot radius of the first spot shape is used as the spot shape corresponding to the motion trajectory.

[0042] In one or more embodiments, the system further comprises a synchronization control device;

[0043] The synchronization control device is used to adjust the trigger time of the laser source emitting laser light, the trigger time of the scanning mirror moving at high speed, and the trigger time recorded by the camera within the exposure time to the same time.

[0044] In one or more embodiments, the system further comprises a collimator;

[0045] The collimator is used to convert the laser light emitted by the laser source into plane light after the laser source emits the laser light and before the scanning mirror receives the laser light emitted by the laser source, and to make the plane light incident on the scanning mirror.

[0046] In a third aspect, an embodiment of the present application provides a device for determining a scanning mirror type, the device comprising:

[0047] The reflection module is used to receive the laser light emitted by the laser source when the scanning mirror moves at high speed, and reflect the laser light to the photosensitive surface of the camera;

[0048] A recording module, configured to record, during the exposure time of the camera, the various motion trajectories of the laser reflected onto the photosensitive surface of the camera, and determine the light spot shape corresponding to each motion trajectory during the high-speed motion of the scanning mirror;

[0049] The surface shape determination module is used to determine the surface shape value corresponding to the scanning mirror based on the corresponding relationship between the preset standard spot shape and the surface shape value, and the spot shape corresponding to each motion trajectory.

[0050] In a fourth aspect, an embodiment of the present invention further provides an electronic device, including:

[0051] Memory and processor;

[0052] The memory is used to store program instructions;

[0053] The processor is configured to call the program instructions stored in the memory and execute the method for determining the scanning mirror type described in the first aspect according to the obtained program.

[0054] In a fifth aspect, an embodiment of the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions. When the computer instructions are executed on a computer, the computer executes the method for determining the scanning mirror type described in the first aspect above.

[0055] The beneficial effects of the embodiments of the present application are as follows: in the embodiments of the present application, when the scanning mirror moves at high speed, it receives the laser emitted by the laser source and reflects the laser to the photosensitive surface of the camera; during the exposure time of the camera, the various motion trajectories of the laser reflected to the photosensitive surface of the camera are recorded, and the light spot shape corresponding to each motion trajectory during the high-speed movement of the scanning mirror is determined; based on the correspondence between the pre-set standard light spot shape and the surface shape value, as well as the light spot shape corresponding to each motion trajectory, the surface shape value corresponding to the scanning mirror is determined.

[0056] Therefore, when the scanning mirror moves at high speed, the motion trajectory of the laser reflected from different positions of the scanning mirror to the camera's photosensitive surface can be recorded, thereby obtaining the corresponding spot shapes of the different positions. Then, based on the correspondence between the standard spot shape and the surface shape value, the corresponding surface shape value of the scanning mirror can be accurately obtained. The system for determining the surface shape of the scanning mirror in this application has a simple structure and simultaneously obtains the spot shapes corresponding to the motion trajectory of the laser reflected from multiple different positions of the scanning mirror, effectively improving the measurement accuracy of the scanning mirror surface shape.

[0057] Other features and advantages of the present application will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present application. The purposes and other advantages of the present application can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments of the present application. Obviously, the drawings introduced below are only some embodiments of the present application.

[0059] Figure 1 A schematic diagram of an interferometer system for full-field heterodyne dynamic interferometry provided in an embodiment of the present application;

[0060] Figure 2 A schematic diagram of a system for measuring the dynamic surface profile MFI using a high-frequency galvanometer provided in an embodiment of the present application;

[0061] Figure 3 A schematic diagram of a system for determining a scanning mirror type provided in an embodiment of the present application;

[0062] Figure 4 A schematic flow chart of a method for determining a scanning mirror type provided in an embodiment of the present application;

[0063] Figure 5 A schematic flow chart of a method for determining a light spot shape provided in an embodiment of the present application;

[0064] Figure 6 A schematic diagram of a first light spot shape provided in an embodiment of the present application;

[0065] Figure 7 A schematic diagram of a standard light spot shape provided in an embodiment of the present application;

[0066] Figure 8 A schematic structural diagram of a scanning mirror type determination device provided in an embodiment of the present application;

[0067] Figure 9 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0068] To make the purpose, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Among them, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0069] Moreover, in the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; “and / or” in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two.

[0070] With the development of satellite Internet technology, scanning mirrors are used in satellite laser communications to reflect light beams to achieve the purpose of imaging.

[0071] However, when the scanning mirror is used in different environments, the surface shape of the scanning mirror will change due to the influence of ambient temperature and solar radiation, affecting the imaging quality. Therefore, it is necessary to measure the surface shape of the scanning mirror to detect whether the surface shape of the scanning mirror has changed.

[0072] In the related art, the measurement of scanning mirror type currently adopts the interference method. The traditional interference method uses phase shift to collect time series images for interference measurement, which has poor real-time performance and is difficult to perform dynamic measurement. The interference measurement method adopts a dedicated optical mechanism design and uses interference fringes for measurement. The shape of the measured surface is measured by the three-dimensional Fourier transform relationship between the frequency of the light wave and the distance. The principle of the two-dimensional cross-section of the three-dimensional Fourier transform of the light field on the detection plane relative to the object is used to measure the light spot using a CCD (Charge Coupled Device), and the single frames are added together to form a three-dimensional data. A three-dimensional Fourier transform is applied to this data to obtain a three-dimensional shape of the measured surface.

[0073] Among them, interferometry methods include full-field heterodyne dynamic interferometry, high-speed dynamic three-dimensional surface measurement, and high-frequency galvanometer dynamic surface MFI (Michelson Fiber Interferomet) measurement.

[0074] like Figure 1 As shown in the figure, the interferometer system used in the full-field heterodyne dynamic interferometry method includes a dual-frequency heterodyne light source module and an interferometry module. The dual-frequency heterodyne light source module uses two low-difference-frequency acousto-optic modulators (AOMs) to provide the beat frequency signal, while the interferometry module uses a Twyman-Green optical path. The interferometric phase difference generated in the interferometric optical path is used to calculate the phase information of the measured surface, thereby measuring the surface shape of the scanning mirror.

[0075] The high-speed dynamic 3D surface measurement method utilizes a measurement system consisting of a digital projector (Samsung SP-P410M), a CCD camera (Daheng Mercury Series MER-050-560U3M), and a computer (Intel Core i5-4258U CPU, 4GB RAM). First, sinusoidal fringes are projected onto a reference plane, and a single frame of reference fringes is captured by the CCD camera. The fringes are then projected onto the rapidly changing object under test, and a series of deformed fringes are continuously captured by the CCD camera at a frame rate of 560 frames per second. Finally, the principal phase value method and phase unwrapping are used to obtain the actual phase distribution, thereby measuring the surface value of the scanning mirror.

[0076] like Figure 2 As shown in the figure, the dynamic surface profile measurement method using a high-frequency galvanometer (MFI) is a multi-field interferometry method that simultaneously captures at least three interference patterns within a single image. Scanning three interference patterns with different reference phase positions generates three corresponding light intensity distribution formulas, differing only in the phase of the reference wave. These calculations reveal the surface profile of the measured surface.

[0077] It can be seen that the traditional scanning mirror interferometric measurement method uses a lot of equipment and the structure of the measurement system is complex, so that the measurement accuracy of the scanning mirror type is affected by the accuracy of multiple devices, and the measurement accuracy is low.

[0078] In view of this, the present application provides a method, system and device for determining the scanning mirror type, which are used to solve the problem of low measurement accuracy when measuring the scanning mirror type using traditional interferometric measurement methods.

[0079] The inventive concept of this application is as follows: when the scanning mirror is moving at high speed, it receives the laser light emitted by the laser source and reflects the laser light to the photosensitive surface of the camera; during the exposure time of the camera, the various motion trajectories of the laser light reflected to the photosensitive surface of the camera are recorded, and the spot shape corresponding to each motion trajectory during the high-speed motion of the scanning mirror is determined; based on the correspondence between the pre-set standard spot shape and the surface shape value, and the spot shape corresponding to each motion trajectory, the surface shape value corresponding to the scanning mirror is determined. When the scanning mirror is moving at high speed, the spot shape corresponding to the motion trajectory of the laser light reflected at multiple different positions of the scanning mirror is recorded, and then according to the correspondence between the standard spot shape and the surface shape value, the surface shape value corresponding to the scanning mirror is accurately obtained, thereby effectively improving the measurement accuracy of the scanning mirror surface shape.

[0080] In order to facilitate understanding of the technical solution provided by the present application, the following first describes the system for determining the scanning mirror type provided by the embodiment of the present application. Figure 3 As shown, the system for determining the scanning mirror type includes a synchronous control device, a laser source, a collimator, a scanning mirror, and a camera, wherein:

[0081] When the scanning mirror is moving at high speed, the laser source emits laser light, which passes through a collimator and converts the laser light (fiber light) emitted by the laser source into plane light covering the surface of the scanning mirror. The plane light is then incident on the scanning mirror in high-speed motion at a preset angle. When the scanning mirror reciprocates, the plane light is reflected by the scanning mirror and incident on the photosensitive surface of the camera. The photosensitive surface of the camera detects at least one motion trajectory of the plane light and obtains the spot shape corresponding to the at least one motion trajectory. Then, based on the pre-set correspondence between the standard spot shape and the surface shape value, and the spot shape corresponding to the at least one motion trajectory, the surface shape value corresponding to the scanning mirror is determined. At the same time, the synchronous control device controls the triggering time of the laser source emitting laser light, the triggering time of the scanning mirror performing high-speed motion, and the triggering time recorded by the camera during the exposure time.

[0082] If the laser emitted by the laser source is a pulsed laser, then during the first exposure time of the camera, each movement trajectory of the pulsed laser reflected onto the photosensitive surface of the camera is recorded;

[0083] If the laser emitted by the laser source is a continuous laser, then during multiple consecutive second exposure times of the camera, the movement trajectories of the continuous laser reflected to the photosensitive surface of the camera are recorded; wherein the first exposure time is greater than the second exposure time.

[0084] If there is only one motion trajectory, the camera determines the surface value corresponding to the spot shape corresponding to the motion trajectory based on the pre-set correspondence between the standard spot shape and the surface value; and uses the surface value corresponding to the spot shape corresponding to the motion trajectory as the surface value corresponding to the scanning mirror;

[0085] If there are multiple motion trajectories, the camera determines the surface shape values ​​corresponding to the spot shapes corresponding to each motion trajectory based on the pre-set correspondence between the standard spot shapes and surface shape values; and takes the average of the surface shape values ​​corresponding to the spot shapes corresponding to each motion trajectory as the surface shape value corresponding to the scanning mirror.

[0086] The camera is also used to obtain a first spot shape corresponding to the motion trajectory of the laser reflected to the photosensitive surface of the camera; use the least squares method to fit a circle to the first spot shape to determine the spot radius of the first spot shape; based on the correspondence between the pre-set spot radius and the standard spot shape, use the standard spot shape corresponding to the spot radius of the first spot shape as the spot shape corresponding to the motion trajectory.

[0087] To further illustrate the technical solutions provided by the embodiments of the present application, the following is a detailed description of the technical solutions in conjunction with the accompanying drawings and specific implementation methods. Although the embodiments of the present application provide the method operation steps as shown in the following embodiments or drawings, more or fewer operation steps may be included in the method based on routine or no creative work. In steps where there is no necessary causal relationship logically, the execution order of these steps is not limited to the execution order provided in the embodiments of the present application.

[0088] See also Figure 4 , is a flow chart of a method for determining a scanning mirror type provided in an embodiment of the present application. The method for determining a scanning mirror type provided in an embodiment of the present application is applied to Figure 3 The scanning mirror type determination system shown in FIG. Figure 4 As shown, the method includes the following steps:

[0089] In step 401, when the scanning mirror moves at high speed, it receives the laser light emitted by the laser source and reflects the laser light to the photosensitive surface of the camera.

[0090] In one or more embodiments, the method further includes: before receiving the laser light emitted by the laser source, converting the laser light emitted by the laser source into planar light.

[0091] In specific implementation, a collimator is set between the laser source and the scanning mirror. The laser emitted by the laser source is collimated by the collimator and converted into plane light covering the surface of the scanning mirror. The plane light is then incident on the scanning mirror at a certain angle. When the scanning mirror moves at high speed, it continuously receives and reflects the plane light converted from the laser.

[0092] Exemplarily, the scanning mirror is set to repeatedly move at a high speed of 200° / s within a preset range of ±10°, the distance between the scanning mirror and the photosensitive surface of the camera is 2m, and the scanning mirror reflects the laser onto the photosensitive surface of the camera.

[0093] In step 402, during the exposure time of the camera, each movement trajectory of the laser reflected to the photosensitive surface of the camera is recorded, and the spot shape corresponding to each movement trajectory during the high-speed movement of the scanning mirror is determined.

[0094] The camera is equipped with a CCD detector, and the parameter information of the CCD detector, such as the response band, resolution, pixel, exposure time, and image storage frequency, is configured. Then, after the trigger time recorded within the exposure time is reached, the camera records the motion trajectory of the plane light after laser conversion reflected to the camera's photosensitive surface according to the configured parameter information.

[0095] For example, using a Xenics XEVA-1614 CCD camera, the camera's response band is set to 0.9μm to 1.7μm, the resolution is 320*256, and the pixel size is 30μm*30μm (30μm×30μm / pix). The exposure time is 1000us, and the image storage frequency is 20Hz. The trajectory of the light beam (plane light) on the photosensitive surface of the CCD camera is then recorded based on the above parameters.

[0096] In the embodiment of the present application, there are two types of lasers emitted by the laser source: one is a pulsed laser and the other is a continuous laser. Therefore, during the exposure time of the camera, recording the motion trajectories of the laser reflected onto the photosensitive surface of the camera can also be implemented in the following two ways:

[0097] Embodiment 1: If the laser emitted by the laser source is a pulsed laser, then during the first exposure time of the camera, each movement trajectory of the pulsed laser reflected to the photosensitive surface of the camera is recorded.

[0098] In a specific implementation, if the laser source emits pulsed laser light, the camera exposure duration is set to a longer exposure duration, i.e., the first exposure duration. During the longer exposure duration, the laser source emits pulsed laser light onto the scanning mirror moving at high speed within a preset range, and the camera continuously receives the pulsed laser light reflected by the scanning mirror moving at high speed within the preset range.

[0099] The scanning mirror moves at high speed within a preset range. Therefore, when pulsed lasers are continuously emitted to the scanning mirror at the same angle, the position where the scanning mirror receives the pulsed lasers is different. If the mirror surface of the scanning mirror is uneven, the movement trajectory of the light beam when reflected on the photosensitive surface of the camera will be different. As a result, within the first exposure time, the camera will record multiple movement trajectories, and each movement trajectory will correspond to a light spot shape.

[0100] However, if the surface of the scanning mirror is completely flat, the movement trajectory of the light beam when reflected onto the photosensitive surface of the camera at different positions will be exactly the same, so that within the first exposure time, the camera will only record one movement trajectory and obtain one spot shape.

[0101] For example, if the scanning mirror is set to move repeatedly at a speed of 200° / s within a preset range of ±10°, the distance between the scanning mirror and the photosensitive surface of the camera is 2m, and the angle of the reflected pulsed laser passing through the photosensitive surface of the camera is 0.25°, and the time is 1.3ms. The laser source emits pulsed laser at a frequency of 100us / time, and the first exposure time of the camera is 1000us. Therefore, if the mirror surface of the scanning mirror is not flat, 10 movement trajectories of the light beam when reflected on the photosensitive surface of the camera will be recorded within 1000us, and 10 spot shapes will be obtained. If the mirror surface of the scanning mirror is completely flat, 10 identical movement trajectories will be recorded within 1000us, and 1 spot shape will be obtained.

[0102] Embodiment 2: If the laser light emitted by the laser source is a continuous laser light, then during a plurality of consecutive second exposure times of the camera, the movement trajectories of the continuous laser light reflected onto the photosensitive surface of the camera are recorded.

[0103] In a specific implementation, if the laser source emits continuous laser light, the camera exposure time is set to a shorter exposure time, i.e., the second exposure time. When the laser source emits continuous laser light onto the scanning mirror moving at high speed within a preset range, the camera then receives the laser light reflected by the scanning mirror moving at high speed within the preset range during multiple consecutive second exposure times.

[0104] The scanning mirror moves at high speed within a preset range. Therefore, when continuous lasers are continuously emitted to the scanning mirror at the same angle, the position where the scanning mirror receives the continuous lasers is different. If the mirror surface of the scanning mirror is uneven, the movement trajectory of the light beam when reflected on the photosensitive surface of the camera will be different. As a result, during the second exposure time, the camera will record multiple movement trajectories, and each movement trajectory will correspond to a light spot shape.

[0105] However, if the surface of the scanning mirror is completely flat, the movement trajectory of the light beam when reflected onto the photosensitive surface of the camera at different positions will be exactly the same, so that within the first exposure time, the camera will only record one movement trajectory and obtain one spot shape.

[0106] For example, if the scanning mirror is set to move repeatedly at a speed of 200° / s within a preset range of ±10°, the distance between the scanning mirror and the camera's photosensitive surface is 2m, and the angle of the reflected continuous laser light passing through the camera's photosensitive surface is 0.25°, the time it takes is 1.3ms. The laser source continuously emits continuous laser light, and the camera's second exposure time is 200us.

[0107] Therefore, if the scanning mirror's surface is uneven, the laser light reflected by the scanning mirror during high-speed motion within a preset range will be received over multiple consecutive 200us periods. For example, in the first 200us, the motion trajectory of the light beam reflected on the camera's photosensitive surface may be recorded, resulting in a single spot shape. In the second 200us, the motion trajectory of the light beam reflected on the camera's photosensitive surface may be recorded, resulting in a single spot shape. Similarly, over multiple consecutive 200us periods, multiple motion trajectories, i.e., multiple corresponding spot shapes, will be obtained. If the scanning mirror's surface is completely flat, multiple identical motion trajectories will be obtained over multiple consecutive 200us periods, resulting in a single spot shape.

[0108] It should be noted that in the above two embodiments, the first exposure time is greater than the second exposure time. Therefore, in the first embodiment, the laser emitted by the laser source is a pulsed laser, and the exposure time of the camera is a long exposure time, while in the second embodiment, the laser emitted by the laser source is a continuous laser, and the exposure time of the camera is a short exposure time.

[0109] In one or more embodiments, whether within the first exposure time of the camera or within multiple consecutive second exposure times, after recording the motion trajectories of the laser reflected to the photosensitive surface of the camera, determining the spot shape corresponding to each motion trajectory during the high-speed motion of the scanning mirror can be specifically performed as follows: Figure 5 Steps shown:

[0110] In step 501, a first spot shape corresponding to a motion trajectory of a laser reflected onto a photosensitive surface of a camera is obtained;

[0111] In step 502, a circle is fitted to the first light spot shape using the least square method to determine the light spot radius of the first light spot shape;

[0112] In step 503 , based on a preset correspondence between a spot radius and a standard spot shape, the standard spot shape corresponding to the spot radius of the first spot shape is used as the spot shape corresponding to the motion trajectory.

[0113] When implementing it specifically, Figure 6 As shown in FIG, when the exposure time of the camera is 1000 us, the motion trajectory of the laser reflected to the photosensitive surface of the camera corresponds to the first spot shape. After the least squares method is used to fit the first spot shape to a circle, the spot radius of the first spot shape is obtained to be 264.777 μm. Therefore, based on the correspondence between the preset spot radius and the standard spot shape, the standard spot shape corresponding to the spot radius of 264.777 μm is obtained, as shown in FIG. Figure 7 As shown in FIG. , the light spot shape corresponding to the motion trajectory is shown in FIG.

[0114] It should be noted that, whether in the first exposure time of the camera or in multiple consecutive second exposure times, if multiple motion trajectories of the laser reflected to the photosensitive surface of the camera are recorded and multiple spot shapes during the high-speed movement of the scanning mirror are obtained, it is necessary to use Figure 5 In the steps shown, a circle is fitted to the first light spot shape corresponding to each motion trajectory using the least squares method, and finally a standard light spot shape corresponding to each motion trajectory is obtained.

[0115] The preset correspondence between the spot radius and the standard spot shape is obtained in advance based on multiple experiments. Any correspondence between the spot radius and the standard spot shape can be used, and this application does not impose any restrictions on this.

[0116] In step 403, the surface shape value corresponding to the scanning mirror is determined based on the preset correspondence between the standard spot shape and the surface shape value, and the spot shape corresponding to each motion trajectory.

[0117] In one or more embodiments, determining the surface shape value corresponding to the scanning mirror based on the correspondence between the preset standard spot shape and the surface shape value, and the spot shape corresponding to each motion trajectory, includes:

[0118] If there is only one motion trajectory, the surface shape value corresponding to the spot shape corresponding to the motion trajectory is determined based on the pre-set correspondence between the standard spot shape and the surface shape value; the surface shape value corresponding to the spot shape corresponding to the motion trajectory is used as the surface shape value corresponding to the scanning mirror;

[0119] If there are multiple motion trajectories, the surface shape values ​​corresponding to the spot shapes corresponding to each motion trajectory are determined based on the pre-set correspondence between the standard spot shape and the surface shape value; the average of the surface shape values ​​corresponding to the spot shapes corresponding to each motion trajectory is used as the surface shape value corresponding to the scanning mirror.

[0120] For example, if the scanning mirror moves repeatedly at a speed of 200° / s within a preset range of ±10°, the laser source emits laser light at a frequency of 100us / time, and the first exposure time of the camera is 1000us, then within the first exposure time of 1000us, 10 movement trajectories of the light beam when reflected on the photosensitive surface of the camera will be recorded, and 10 spot shapes will be obtained. Then, it is necessary to perform circular fitting on these 10 spot shapes, and finally obtain the standard spot shapes corresponding to these 10 spot shapes. Then, according to the pre-set correspondence between the standard spot shapes and the surface shape values, determine the surface shape values ​​corresponding to these 10 spot shapes; the average of the surface shape values ​​corresponding to these 10 spot shapes is used as the final surface shape value of the scanning mirror, that is, the measurement result of the dynamic surface shape of the scanning mirror is obtained.

[0121] In one or more embodiments, in order to ensure the accuracy of the measurement results of the dynamic surface shape of the scanning mirror, the embodiments of the present application also need to set the trigger time of the laser source emitting laser, the trigger time of the scanning mirror performing high-speed movement, and the trigger time recorded by the camera within the exposure time to be the same.

[0122] Therefore, in the embodiment of the present application, when the scanning mirror moves at high speed, it receives the laser emitted by the laser source and reflects the laser to the photosensitive surface of the camera; during the exposure time of the camera, the various motion trajectories of the laser reflected to the photosensitive surface of the camera are recorded, and the spot shape corresponding to each motion trajectory during the high-speed movement of the scanning mirror is determined; based on the correspondence between the pre-set standard spot shape and the surface shape value, as well as the spot shape corresponding to each motion trajectory, the surface shape value corresponding to the scanning mirror is determined.

[0123] When the scanning mirror moves at high speed, the present application can record the motion trajectory of the laser beam reflected from different positions of the scanning mirror to the camera's photosensitive surface, thereby obtaining the corresponding spot shapes at different positions. Then, based on the correspondence between the standard spot shape and the surface shape value, the surface shape value corresponding to the scanning mirror can be accurately obtained. The scanning mirror surface shape determination system in the present application has a simple structure and simultaneously obtains the spot shapes corresponding to the motion trajectory of the laser beam reflected from multiple different positions of the scanning mirror, effectively improving the measurement accuracy of the scanning mirror surface shape.

[0124] Based on the same inventive concept, the embodiment of the present application also provides a device for determining the scanning mirror type, such as Figure 8 As shown, the device includes:

[0125] The reflection module 801 is used to receive the laser light emitted by the laser source when the scanning mirror moves at high speed, and reflect the laser light to the photosensitive surface of the camera;

[0126] The recording module 802 is used to record the motion trajectories of the laser reflected onto the photosensitive surface of the camera during the exposure time of the camera, and determine the spot shape corresponding to each motion trajectory during the high-speed motion of the scanning mirror;

[0127] The surface shape determination module 803 is configured to determine the surface shape value corresponding to the scanning mirror based on the correspondence between the preset standard spot shape and the surface shape value, and the spot shape corresponding to each motion trajectory.

[0128] In one or more embodiments, the recording module 802 is specifically configured to:

[0129] If the laser emitted by the laser source is a pulsed laser, then within the first exposure time of the camera, each movement trajectory of the pulsed laser reflected onto the photosensitive surface of the camera is recorded;

[0130] If the laser light emitted by the laser source is a continuous laser light, then within a plurality of consecutive second exposure times of the camera, each movement trajectory of the continuous laser light reflected onto the photosensitive surface of the camera is recorded;

[0131] The first exposure duration is greater than the second exposure duration.

[0132] In one or more embodiments, the face shape determination module 803 is specifically configured to:

[0133] If there is only one motion trajectory, the surface shape value corresponding to the spot shape corresponding to the motion trajectory is determined based on the pre-set correspondence between the standard spot shape and the surface shape value; and the surface shape value corresponding to the spot shape corresponding to the motion trajectory is used as the surface shape value corresponding to the scanning mirror;

[0134] If there are multiple motion trajectories, the surface shape values ​​corresponding to the spot shapes corresponding to each motion trajectory are determined based on the pre-set correspondence between the standard spot shape and the surface shape value; the average of the surface shape values ​​corresponding to the spot shapes corresponding to each motion trajectory is used as the surface shape value corresponding to the scanning mirror.

[0135] In one or more embodiments, the recording module 802 is specifically configured to:

[0136] For each motion track, perform the following operations:

[0137] Acquire a first light spot shape corresponding to the motion trajectory of the laser reflected onto the photosensitive surface of the camera;

[0138] Performing circle fitting on the first light spot shape using the least squares method to determine the spot radius of the first light spot shape;

[0139] Based on a preset correspondence between a spot radius and a standard spot shape, the standard spot shape corresponding to the spot radius of the first spot shape is used as the spot shape corresponding to the motion trajectory.

[0140] In one or more embodiments, the device further includes a control module for controlling the triggering time of the laser source emitting laser light, the triggering time of the scanning mirror performing high-speed movement, and the triggering time recorded by the camera within the exposure time to be the same.

[0141] In one or more embodiments, the device further includes a conversion module configured to convert the laser light emitted by the laser source into planar light before receiving the laser light emitted by the laser source.

[0142] Based on the same inventive concept as the embodiment of the present application, the embodiment of the present application provides the following Figure 9 An electronic device as shown, Figure 9As shown, it includes: a processor 901, a communication interface 902, a memory 903 and a communication bus 904, wherein the processor 901, the communication interface 902, and the memory 903 communicate with each other through the communication bus 904;

[0143] The memory 903 stores a computer program. When the program is executed by the processor 901 , the processor 901 executes the method for determining the scanning mirror type provided in the present application.

[0144] The communication bus mentioned in the above-mentioned electronic device can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. The communication bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, only one thick line is used in the figure, but it does not mean that there is only one bus or one type of bus. The communication interface 902 is used for communication between the above-mentioned electronic device and other devices. The memory can include random access memory (RAM) or non-volatile memory (NVM), such as at least one disk storage. Optionally, the memory can also be at least one storage device located away from the aforementioned processor. The above-mentioned processor can be a general-purpose processor, including a central processing unit, a network processor (NP), etc.; it can also be a digital signal processing (DSP), an application-specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, etc.

[0145] Based on the above embodiments, the present application further provides a computer-readable storage medium, such as a memory including instructions, wherein the instructions can be executed by a processor to perform the above method for determining the scanning mirror type. Optionally, the storage medium can be a non-transitory computer-readable storage medium, such as a ROM, random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device.

[0146] Since the principle of solving the problem provided by the computer-readable medium is similar to the method for determining the scanning mirror type, after the processor executes the computer program in the computer-readable medium, the steps implemented can refer to the above embodiment, and the repeated parts will not be repeated.

[0147] Based on the above embodiments, the present application further provides a computer program product, including a computer program, which, when executed by a processor, implements any of the methods for determining the scanning mirror type provided in the present application.

[0148] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0149] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0150] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0151] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0152] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. These modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents.

Claims

1. A method for determining a scanning mirror type, characterized in that: The method comprises: When the scanning mirror moves at high speed, it receives the laser emitted by the laser source; reflecting the laser light onto a photosensitive surface of a camera; During the exposure time of the camera, the motion trajectories of the laser reflected onto the photosensitive surface of the camera are recorded, and the light spot shapes corresponding to the motion trajectories during the high-speed motion of the scanning mirror are determined; The surface shape value corresponding to the scanning mirror is determined based on the correspondence between the preset standard spot shape and the surface shape value, and the spot shape corresponding to each motion trajectory.

2. The method according to claim 1, characterized in that The step of recording the movement trajectories of the laser reflected from the photosensitive surface of the camera during the exposure time of the camera includes: If the laser emitted by the laser source is a pulsed laser, then within the first exposure time of the camera, each movement trajectory of the pulsed laser reflected onto the photosensitive surface of the camera is recorded; If the laser light emitted by the laser source is a continuous laser light, then within a plurality of consecutive second exposure times of the camera, each movement trajectory of the continuous laser light reflected onto the photosensitive surface of the camera is recorded; The first exposure duration is greater than the second exposure duration.

3. The method according to any one of claims 1-2, characterized in that The determining of the surface shape value corresponding to the scanning mirror based on the correspondence between the preset standard spot shape and the surface shape value and the spot shape corresponding to each motion trajectory includes: If there is only one motion trajectory, the surface shape value corresponding to the spot shape corresponding to the motion trajectory is determined based on the pre-set correspondence between the standard spot shape and the surface shape value; and the surface shape value corresponding to the spot shape corresponding to the motion trajectory is used as the surface shape value corresponding to the scanning mirror; If there are multiple motion trajectories, the surface shape values ​​corresponding to the spot shapes corresponding to each motion trajectory are determined based on the pre-set correspondence between the standard spot shape and the surface shape value; the average of the surface shape values ​​corresponding to the spot shapes corresponding to each motion trajectory is used as the surface shape value corresponding to the scanning mirror.

4. The method according to any one of claims 1-2, characterized in that Determining the light spot shape corresponding to each motion trajectory during the high-speed motion of the scanning mirror includes: For each motion track, perform the following operations: Acquire a first light spot shape corresponding to the motion trajectory of the laser reflected onto the photosensitive surface of the camera; Performing circle fitting on the first light spot shape using the least squares method to determine the spot radius of the first light spot shape; Based on a preset correspondence between a spot radius and a standard spot shape, the standard spot shape corresponding to the spot radius of the first spot shape is used as the spot shape corresponding to the motion trajectory.

5. The method according to claim 1, wherein The triggering time of the laser source emitting laser light, the triggering time of the scanning mirror performing high-speed movement, and the triggering time recorded by the camera within the exposure time are the same.

6. The method according to claim 1, characterized in that The method further comprises: Before receiving the laser light emitted by the laser source, the laser light emitted by the laser source is converted into planar light.

7. A system for determining a scanning mirror type, characterized in that: The system includes a laser source, a scanning mirror, and a camera, wherein: The laser source is used to emit laser light toward the scanning mirror when the scanning mirror moves at high speed; The scanning mirror is used to receive the laser light emitted by the laser source when performing high-speed movement, and reflect the laser light to the photosensitive surface of the camera; The camera is used to record the various motion trajectories of the laser reflected onto the photosensitive surface of the camera during the exposure time, and determine the spot shape corresponding to each motion trajectory during the high-speed movement of the scanning mirror; based on the correspondence between the pre-set standard spot shape and the surface shape value, and the spot shape corresponding to each motion trajectory, determine the surface shape value corresponding to the scanning mirror.

8. The system according to claim 7, characterized in that If the laser light emitted by the laser source is a pulsed laser light, the camera is specifically configured to: record, during a first exposure time of the camera, each movement trajectory of the pulsed laser light reflected onto the photosensitive surface of the camera; If the laser light emitted by the laser source is a continuous laser light, the camera is specifically configured to: record, during a plurality of consecutive second exposure times of the camera, each movement trajectory of the continuous laser light reflected onto the photosensitive surface of the camera; The first exposure duration is greater than the second exposure duration.

9. An electronic device, characterized in that: include: Memory and processor; The memory is used to store program instructions; The processor is configured to call the program instructions stored in the memory and execute the method for determining the scanning mirror type according to any one of claims 1 to 6 according to the obtained program.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer instructions, and when the computer instructions are executed on a computer, the computer is caused to execute the method for determining the scanning mirror type according to any one of claims 1 to 6.

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