Speckle projection device and binocular speckle stereo-camera

Abstract

A speckle projection device (10) and a binocular speckle stereo-camera. The speckle projection device (10) comprises: a speckle projector (1), a reflective mirror (2), and one or more electromagnetic control units (3). The reflective mirror (2) is arranged on a projection optical path of the speckle projector (1) and is used for reflecting a speckle image projected by the speckle projector (1) to a photographing region of the binocular speckle stereo-camera. Each electromagnetic control unit (3) comprises a first magnet (31) fixedly mounted at the edge of the reflective mirror (2) and a second magnet (32) spaced apart from the reflective mirror (2); and one of the first magnet (31) and the second magnet (32) is a permanent magnet, and the other one is an electromagnet, so that upon energization, the electromagnet generates an attractive or repulsive force with the permanent magnet to drive the reflective mirror (2) to generate a pose change, such that speckle patterns projected under different poses are dynamically changed, ensuring speckle pattern coverage at different positions in the photographing region, thus increasing a speckle pattern coverage region.

Description

Speckle projection device and binocular speckle stereo camera

[0001] This application claims priority to Chinese patent application No. 202410190073.5 filed with the Patent Office of China on February 20, 2024, entitled “A Speckle Projection Device and Binocular Speckle Stereo Camera,” the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present application relates to the technical field of binocular stereo cameras, and in particular to a speckle projection device and a binocular speckle stereo camera. Background Art

[0003] A binocular speckle stereo camera is a stereo camera improved based on binocular matching technology. It solves the problem that binocular matching cannot match textureless or textureless surfaces by actively projecting speckle patterns. It is also called an active binocular stereo camera.

[0004] As shown in Figure 1, a binocular speckle stereo camera in related art includes a first imaging unit 101, a second imaging unit 102, and a speckle projection device 103. The speckle projection device 103 is used to project discrete light beams onto a captured area, forming multiple discrete spots within the captured area. The first imaging unit 101 and the second imaging unit 102 capture one or more sets of two-dimensional images. These sets of two-dimensional images are then matched to identify the corresponding pixel of each image in an image from another perspective, calculate a disparity image, and estimate a depth map.

[0005] In order to further improve the depth map acquisition accuracy of binocular speckle stereo cameras, a multi-frame fusion solution is usually adopted, which requires the speckle texture projected by the camera to change so that texture coverage can be achieved at different positions.

[0006] However, in the related art, the speckle texture projected by the speckle projection device is usually static, which results in a limited area covered by the speckle texture in the shooting area and low depth map acquisition accuracy of the binocular speckle stereo camera. Summary of the Invention

[0007] The purpose of the embodiments of the present application is to provide a speckle projection device and a binocular speckle stereo camera, so that the speckle projection device can dynamically project speckle textures, increase the speckle texture coverage area, and improve the depth map acquisition accuracy. The specific technical solutions are as follows:

[0008] The present application provides a speckle projection device, which is applied to a binocular speckle stereo camera; the device comprises: a speckle projector, a reflective lens, and one or more electromagnetic control units;

[0009] Wherein, the reflective lens is arranged on the projection light path of the speckle projector, and is used to reflect the speckle image projected by the speckle projector to the shooting area of ​​the binocular speckle stereo camera;

[0010] Each of the electromagnetic control units includes a first magnet fixedly mounted on the edge of the reflective lens and a second magnet spaced apart from the reflective lens; wherein, one of the first magnet and the second magnet is a permanent magnet and the other is an electromagnet; so that when the electromagnet is energized, it generates an attractive force or a repulsive force with the permanent magnet, thereby driving the reflective lens to change its posture.

[0011] In some embodiments, the first magnet is a permanent magnet, and the second magnet is an electromagnet; the polarity of the permanent magnet is distributed along the reflective lens from the inside to the outside, and a single magnetic pole extends out of the reflective lens and is opposite to the electromagnet; the electromagnet is a U-shaped electromagnet, and the two poles of the U-shaped electromagnet are respectively spaced apart from the single magnetic pole of the permanent magnet, and their positions are symmetrical; or, there are two electromagnets, which are respectively spaced apart from the single magnetic pole of the permanent magnet, and their positions are symmetrical.

[0012] In some embodiments, the first magnet is a permanent magnet, and the second magnet includes two electromagnets; the polarity of the permanent magnet is perpendicular to the reflective lens; the polarity directions of the two electromagnets are distributed vertically along the reflective lens, and the two electromagnets are respectively spaced apart from the two poles of the permanent magnet and are symmetrically positioned; when the two electromagnets are energized, the same polarity faces the permanent magnet.

[0013] In some embodiments, the first magnet is an electromagnet, and the second magnet includes two permanent magnets; the polarity of the electromagnet is perpendicular to the reflective lens; the polarity directions of the two permanent magnets are distributed vertically along the reflective lens, and the polarities are opposite; the two permanent magnets are respectively spaced apart from the two poles of the electromagnet, and their positions are symmetrical.

[0014] In some embodiments, when there are multiple electromagnetic control units, the multiple electromagnetic control units are arranged along the circumference of the reflective lens.

[0015] In some embodiments, the device further comprises: a first mounting plate, a second mounting plate, and a third mounting plate; wherein the first mounting plate and the second mounting plate are parallel to each other and spaced apart; the third mounting plate is disposed between the first mounting plate and the second mounting plate, and the distance between the third mounting plate and the first mounting plate and the second mounting plate is adjustable;

[0016] The reflective lens is installed in the first hollow area in the middle of the third mounting plate; the first magnet is installed in the magnet mounting hole at the edge of the third mounting plate;

[0017] There are two second magnets, which are respectively installed in two magnet installation grooves on the edges of the first installation plate and the second installation plate; the two magnet installation grooves open toward the magnet installation holes and are positioned correspondingly.

[0018] In some embodiments, the first magnet is an electromagnet, and the second magnet is a permanent magnet;

[0019] The magnet mounting hole of the third mounting plate is a through hole, and the two poles of the electromagnet installed in the magnet mounting hole are one facing the permanent magnet installed on the first mounting plate, and the other facing the permanent magnet installed on the second mounting plate; the polarity directions of the permanent magnets of the first mounting plate and the second mounting plate are perpendicular to the distribution of the reflective lens, and the polarities are opposite.

[0020] In some embodiments, the first mounting plate, the third mounting plate and the second mounting plate are connected by mounting posts; wherein the first end of the mounting post is fixedly connected to the edge of the first mounting plate; the middle portion of the mounting post passes through a connecting through-hole at the edge of the third mounting plate; the second end of the mounting post is fixedly connected to the edge of the second mounting plate; and the diameter of the connecting through-hole is larger than the diameter of the mounting post, so that the third mounting plate can move relative to the mounting post to adjust the distance of the third mounting plate between the first mounting plate and the second mounting plate.

[0021] In some embodiments, the number of the first magnets is multiple; the number of the magnet mounting holes on the edge of the third mounting plate is the same as the number of the first magnets, and they are evenly arranged circumferentially around the first hollow area;

[0022] The number of the second magnets is multiple pairs, and the number of magnet mounting slots on the edges of the first mounting plate and the second mounting plate is the same as the number of the second magnets, and their positions correspond to the positions of the first magnets respectively.

[0023] In some embodiments, the first end of the mounting post is fixedly connected to the first mounting hole on the edge of the first mounting plate; the second end of the mounting post is fixedly connected to the second mounting hole on the edge of the second mounting plate;

[0024] The number of the connecting through holes of the third mounting plate is multiple; the number of the first mounting holes of the first mounting plate and the number of the second mounting holes of the second mounting plate are the same as the number of the connecting through holes;

[0025] The positions of the plurality of connecting through holes of the third mounting plate are staggered with the plurality of magnet mounting holes;

[0026] The first mounting holes of the first mounting plate and the second mounting holes of the second mounting plate are respectively arranged alternately with the magnet mounting slots.

[0027] In some embodiments, the first mounting plate, the third mounting plate, and the second mounting plate have the same appearance; wherein, the second mounting plate is installed toward the shooting area; the second mounting plate is provided with a second hollow area; the second hollow area corresponds to the position of the first hollow area, and the two have the same shape and size.

[0028] In some embodiments, the device further comprises: a driving module; the driving module comprises: a control circuit and a power supply circuit; the power supply circuit is electrically connected to the control circuit and the electromagnets in each of the electromagnetic control units;

[0029] The control circuit is used to send a coded instruction to the power supply circuit; the coded instruction is used to identify the direction of the current passing through each electromagnet; so that the power supply circuit provides forward or reverse current to each electromagnet according to the coded instruction;

[0030] Each electromagnet is driven by the forward or reverse current to generate an attractive force or a repulsive force with the permanent magnet.

[0031] In some embodiments, the device further includes: a housing; the housing is used to accommodate the various components; the bottom of the housing is provided with an opening facing a shooting area; the speckle image reflected by the reflective lens is reflected through the opening to a shooting area of ​​the binocular speckle stereo camera.

[0032] An embodiment of the present application further provides a binocular speckle stereo camera, comprising: any one of the above-mentioned speckle projection devices, a camera bracket, and two cameras; the two cameras are respectively arranged at two ends of the camera bracket, and their lens fields of view cover a target shooting area; the speckle projection device is arranged on the camera bracket and is capable of reflecting a speckle image projected by the speckle projector to the target shooting area.

[0033] Beneficial effects of the embodiments of the present application:

[0034] The speckle projection device and binocular speckle stereo camera provided in embodiments of the present application reflect the speckle image projected by the speckle projector onto the capture area of ​​the binocular speckle stereo camera via a reflective lens. An electromagnetic control unit achieves discrete positional changes in the reflective lens by engaging electromagnets, thereby achieving dynamic speckle projection. Specifically, the electromagnetic control unit includes a first magnet fixedly mounted on the edge of the reflective lens and a second magnet spaced apart from the reflective lens; one of the first and second magnets is a permanent magnet, and the other is an electromagnet. Thus, when the electromagnet is energized, it generates an attractive or repulsive force with the permanent magnet, thereby driving the reflective lens to change its position. This results in dynamic changes in the projected speckle texture at different positions, ensuring that the speckle texture covers different locations in the capture area. This increases the speckle texture coverage area, improves the image matching accuracy of the binocular speckle stereo camera, and thus improves the depth map acquisition accuracy of the binocular speckle stereo camera.

[0035] Of course, it is not necessary to achieve all the advantages described above at the same time when implementing any product or method of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings described herein are used to provide further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute improper limitations on the present application.

[0037] FIG1 is a schematic diagram of the principle of a binocular speckle stereo camera in the related art;

[0038] FIG2 is a schematic structural diagram of a first embodiment of a speckle projection device provided in an embodiment of the present application;

[0039] FIG3 is a schematic diagram of the working principle of the speckle projection device provided in an embodiment of the present application;

[0040] FIG4 a is a schematic diagram of a structure of an electromagnetic control unit in which a permanent magnet is bound to a reflective lens;

[0041] FIG4 b is another schematic diagram of the structure of an electromagnetic control unit in which a permanent magnet is bound to a reflective lens;

[0042] FIG5 is a schematic diagram of the structure of an electromagnetic control unit in which an electromagnet is bound to a reflective lens;

[0043] Figures 6a to 6c are schematic diagrams of three arrangements of electromagnetic control units;

[0044] FIG7 is a schematic structural diagram of a second embodiment of a speckle projection device provided in an embodiment of the present application;

[0045] FIG8a is a schematic diagram of a structure of the connection between the electromagnetic control unit and the reflective lens;

[0046] FIG8b is a structural diagram of the third mounting plate in the embodiment shown in FIG8a;

[0047] FIG8c is a structural diagram of the second mounting plate in the embodiment shown in FIG8a;

[0048] FIG9 is a schematic diagram of another structure of the connection between the electromagnetic control unit and the reflective lens;

[0049] FIG10 is a schematic structural diagram of a third embodiment of a speckle projection device provided in an embodiment of the present application;

[0050] FIG11 is a schematic diagram of the structure of a binocular speckle stereo camera provided in an embodiment of the present application.

[0051] Reference numerals:

[0052] Speckle projector 1; reflective lens 2; electromagnetic control unit 3, first magnet 31, second magnet 32;

[0053] First mounting plate 4, magnet mounting slot 41; second mounting plate 5, magnet mounting slot 51, second mounting hole 52, second hollow area 53;

[0054] The third mounting plate 6, the first hollow area 61, the magnet mounting hole 62, and the connecting through hole 63;

[0055] Mounting post 7, first end 71, middle portion 72, second end 73;

[0056] Drive module 8, control circuit 81, power supply circuit 82; housing 9, opening 91;

[0057] Speckle projection device 10 , camera bracket 11 , camera 12 , camera 13 . DETAILED DESCRIPTION

[0058] To make the objectives, technical solutions, and advantages of this application more clearly understood, the present application is further described below with reference to the accompanying drawings and examples. It is apparent that the described examples are only a portion of the embodiments of this application, and not all of them. All other embodiments derived by persons of ordinary skill in the art based on the examples in this application are intended to fall within the scope of protection of this application.

[0059] In order to enable a speckle projection device to dynamically project speckle textures, increase the speckle texture coverage area, and improve the depth map acquisition accuracy, the present application provides a speckle projection device and a binocular speckle stereo camera, which are described in detail below.

[0060] The speckle projection device provided in the embodiments of the present application is applied to a binocular speckle stereo camera. Referring to FIG2 , FIG2 is a schematic structural diagram of a first embodiment of the speckle projection device provided in the embodiments of the present application. The speckle projection device comprises: a speckle projector 1, a reflective lens 2, and one or more electromagnetic control units 3. The reflective lens 2 is disposed in the projection light path of the speckle projector 1 and is configured to reflect the speckle image projected by the speckle projector 1 to the capture area of ​​the binocular speckle stereo camera. Each electromagnetic control unit 3 comprises a first magnet 31 fixedly mounted on the edge of the reflective lens 2 and a second magnet 32 ​​spaced apart from the reflective lens 2. One of the first magnet 31 and the second magnet 32 ​​is a permanent magnet, and the other is an electromagnet. When energized, the electromagnet generates an attractive or repulsive force with the permanent magnet, driving the reflective lens 2 to change its position.

[0061] As can be seen from the embodiment shown in FIG2 , when the electromagnet in the electromagnetic control unit 3 is energized, it will generate an attractive or repulsive force with the permanent magnet, thereby driving the reflective lens 2 to change its posture. This causes the speckle texture projected at different postures to dynamically change, ensuring that the speckle texture covers different positions in the shooting area, increasing the speckle texture coverage area, improving the image matching accuracy of the binocular speckle stereo camera, and thus improving the depth map acquisition accuracy of the binocular speckle stereo camera.

[0062] Refer to Figure 3, which illustrates the operating principle of the speckle projection device provided by an embodiment of the present application. Reflector 2 is positioned in the projection light path of speckle projector 1. Thus, speckle projector 1 projects a speckle pattern onto the reflective surface of reflector 2. The projected light forms an angle θ with the normal to the reflective surface. The projected light is then deflected to the other side of the normal at an angle θ, continuing toward the capture area of ​​the binocular speckle stereo camera. When the reflective surface of reflector 2 deflects, the angle θ shifts by Δθ, and the reflected light shifts its projection direction by a factor of 2 Δθ. Consequently, the position of the projected speckle pattern changes, increasing the area covered by the speckle pattern.

[0063] There are at least two implementation methods of the electromagnetic control unit 3 in the embodiment of the present application:

[0064] The first type: the permanent magnet is bound to the reflective lens 2.

[0065] As shown in FIG2 and FIG4a, FIG4a is a structural diagram of an electromagnetic control unit in which a permanent magnet is bound to a reflective lens; the first magnet 31 of the electromagnetic control unit 3 is a permanent magnet, and the second magnet 32 ​​is an electromagnet.

[0066] The permanent magnet is fixed to the reflector 2, and its magnetization direction should be parallel to the reflector 2. That is, the polarity of the permanent magnet is distributed from the inside out of the reflector 2, with a single pole extending from the reflector to face the electromagnet. For example, as shown in Figure 4a, the permanent magnet can be a bar-shaped permanent magnet, and the electromagnet can be a U-shaped electromagnet with a coil located between its two poles. The anode and a portion of the cathode of the bar-shaped permanent magnet are mounted on the edge of the reflector 2 from the inside out, with the cathode extending from the reflector to face the U-shaped electromagnet. The poles of the U-shaped electromagnet are spaced symmetrically from the cathode of the permanent magnet. In this way, the cathode on the reflector 2 is controlled by the electromagnet. When a positive current flows through the electromagnet, the upper portion of the electromagnet coil becomes the anode, and the lower portion becomes the cathode. At this point, the cathode below the electromagnet generates a repulsive force with the cathode on the reflector 2, while the anode above the electromagnet generates an attractive force with the cathode on the reflector 2, thereby driving the reflector 2 to the first position shown in Figure 4a. When a reverse current passes through the electromagnet, the upper part of the electromagnet coil switches to the cathode and the lower part switches to the anode, thereby driving the reflective lens 2 to switch to the opposite second posture state.

[0067] In other embodiments of this method, the electromagnetic control unit 3 may not use a U-shaped electromagnet, but may use two rectangular electromagnets instead. The two rectangular electromagnets are respectively spaced apart from the cathode of the permanent magnet and are symmetrically positioned. The working principle is the same as above and will not be repeated here.

[0068] In the above embodiment, the magnetization direction of the permanent magnet is parallel to the reflective lens 2 . In some embodiments, the magnetization direction of the permanent magnet may also be perpendicular to the reflective lens 2 .

[0069] Specifically, as shown in Figure 4b, Figure 4b is another structural schematic diagram of an electromagnetic control unit in which a permanent magnet is bound to a reflective lens. Among them, the first magnet 31 is a permanent magnet, which is bound to the reflective lens 2, and the polarity of the permanent magnet is perpendicular to the reflective lens 2. As shown in Figure 4b, the second magnet 32 ​​includes two electromagnets; the polarity directions of the two electromagnets are distributed vertically along the reflective lens, and the two electromagnets are respectively spaced apart from the two poles of the permanent magnet and symmetrically positioned; after the two electromagnets are energized, the same polarity faces the permanent magnet. Among them, the two electromagnets can pass opposite currents to ensure that the polarities of the two electromagnets are opposite, that is, the polarity of the electrodes facing the permanent magnet is the same.

[0070] The second type: the electromagnet is bound to the reflective lens 2.

[0071] As shown in Figure 5, it is a schematic diagram of the structure of an electromagnetic control unit with an electromagnet attached to a reflective lens. The first magnet 31 of the electromagnetic control unit 3 is an electromagnet, and the second magnet 32 ​​comprises two permanent magnets. The polarity of the electromagnet is perpendicular to the reflective lens 2; the polarity of the two permanent magnets is perpendicular to the reflective lens 2 and has opposite polarities. In this case, the same poles of the two permanent magnets are close to the electromagnet; the two permanent magnets are spaced apart and symmetrically positioned relative to the two poles of the electromagnet.

[0072] In this embodiment, as shown in Figure 5, the anodes of the two permanent magnets face the electromagnet. When a positive current flows through the electromagnet, as shown in Figure 5, the upper end of the electromagnet becomes the cathode and the lower end becomes the anode. The cathode of the electromagnet and the anode of the permanent magnet generate an attractive force, while the anode of the electromagnet and the anode of the permanent magnet generate a repulsive force. In other embodiments of this method, the cathodes of the two permanent magnets can also face the electromagnet, which is not a limitation here.

[0073] It can be seen from the above embodiments that in the first magnet 31 and the second magnet 32 ​​of the electromagnetic control unit 3 in this embodiment, only one of them needs to be a permanent magnet and the other an electromagnet. They can be flexibly set according to actual needs and have the advantages of simple structure, easy implementation and low cost.

[0074] The speckle projection device provided in the embodiment of the present application may include a plurality of electromagnetic control units 3. When there are multiple electromagnetic control units 3, the plurality of electromagnetic control units 3 are arranged along the circumference of the reflective lens 2. Specifically, the arrangement may be uniform or uneven. The shape of the reflective lens 2 of the speckle projection device provided in the embodiment of the present application can be set according to actual needs, for example, it can be circular or rectangular.

[0075] Taking the circular reflector 2 as an example, see Figures 6a to 6c, which are schematic diagrams of three electromagnetic control unit arrangements. As shown in Figure 6a, when there are two electromagnetic control units 3, the two electromagnetic control units 3 can be arranged symmetrically. In other embodiments, they can also be arranged asymmetrically. The only difference between the asymmetrical arrangement and the symmetrical arrangement is that the posture symmetry and control stability are slightly worse. When there are one or two electromagnetic control units 3, one-dimensional control of the reflector 2 can be achieved. Specifically, as mentioned above, when there is only one electromagnetic control unit 3, the reflector 2 can be controlled to switch between the first and second postures. When there are two electromagnetic control units 3, whether the two electromagnetic control units 3 are arranged symmetrically or asymmetrically, the reflector 2 achieves posture changes with the center vertical line connecting the two electromagnetic control units 3 as the axis.

[0076] Each electromagnetic control unit 3 can achieve two postures: posture 1 and posture 2. These can be represented using binary coding, with 0 and 1 representing posture 1 and posture 2, respectively, that can be achieved by one electromagnetic control unit 3. Bits 0 and 1 represent the postures that can be achieved by two electromagnetic control units 3, respectively. Therefore, the reflector 2 can achieve a total of four postures: 00, 01, 10, and 11. In postures 00 and 11, although the positions of the speckle textures may be the same, their sizes are different, resulting in two different postures.

[0077] As shown in Figure 6b, if there are three electromagnetic control units 3, they can be evenly arranged around the reflector lens 2. In this case, the reflector lens 2 can achieve eight posture control options: 000, 001, 010, 011, 100, 101, 110, and 111. Furthermore, these posture transitions no longer occur along a single axis, but rather along multiple axes, resulting in two-dimensional posture control.

[0078] As shown in Figure 6c, when there are four electromagnetic control units 3, they can be evenly and symmetrically arranged around the reflector lens 2. In this case, according to the binary code, there are a total of sixteen possible positions: 0000, 0001, ..., 1111. However, considering that the reflector is a rigid body, the two identical coding states of 0101 and 1010 are essentially unstable. When the control units are symmetrically distributed, ignoring the electromagnetic force differences of the electromagnetic control units 3, the four coding pairs of 1000 and 1101, 0100 and 1110, 0010 and 0111, and 0001 and 1011 have the same effect, resulting in a total of ten valid coding options.

[0079] In fact, the more electromagnetic control units 3 there are, the more possible postures there are, which will also increase the structural complexity of the speckle projection device. From the perspective of practical applications, considering factors such as structural stability and complexity, three electromagnetic control units 3 is a relatively better choice.

[0080] As can be seen from the above embodiments, the use of electromagnets to engage the reflector lens 2 can achieve discrete position changes. When there are one or two electromagnetic control units 3, one-dimensional adjustment of the reflector lens 2's position can be achieved; when there are three or more electromagnetic control units 3, two-dimensional adjustment of the reflector lens 2's position can be expanded.

[0081] Refer to Figure 7, which is a schematic diagram of the structure of a second embodiment of a speckle projection device provided by the present application. In this embodiment, there are two electromagnetic control units 3, symmetrically arranged horizontally along the reflector lens 2. The first magnet 31 of each electromagnetic control unit 3 is an electromagnet, and the second magnet 32 ​​is a permanent magnet. There are two permanent magnets, each spaced apart from the reflector lens 2 and symmetrically positioned vertically relative to the edge of the reflector lens 2. The specific structure of each electromagnetic control unit 3 in this embodiment can be the same as the electromagnetic control unit 3 shown in Figure 5 and will not be repeated here.

[0082] As mentioned above, it is relatively better to have three electromagnetic control units 3. Hereinafter, the specific structure of the electromagnetic control unit 3 will be described in detail by taking the case where there are three electromagnetic control units 3 and the reflective lens 2 is circular as an example.

[0083] Referring to Figures 8a to 8c, Figure 8a is a schematic diagram of the structure of the connection between the electromagnetic control unit and the reflective lens; Figure 8b is a structural diagram of the third mounting plate in the embodiment shown in Figure 8a; and Figure 8c is a structural diagram of the second mounting plate in the embodiment shown in Figure 8a. Figure 8c shows the internal structure of the second mounting plate in Figure 8a, flipped horizontally 180°.

[0084] In this embodiment, the electromagnet is bound to the reflective lens 2 .

[0085] Specifically, as shown in FIG8a to FIG8c , the first magnet 31 fixedly mounted on the edge of the reflective lens 2 is an electromagnet (illustrated as a coil in the figure), and the second magnet 32 ​​is a permanent magnet, and there are two permanent magnets.

[0086] In this embodiment, a three-layer structure is formed using three mounting plates to connect the electromagnetic control unit to the reflective lens. As shown in Figure 8a, the speckle projection device of this embodiment further includes a first mounting plate 4, a second mounting plate 5, and a third mounting plate 6. The first and second mounting plates 4, 5 are parallel to each other and spaced apart. The third mounting plate 6 is positioned between the first and second mounting plates 4, 5, and the distance between the third mounting plate 6 and the first and second mounting plates 4, 5 is adjustable.

[0087] As shown in Figures 8a to 8c, the reflective lens 2 is mounted in the first hollowed-out area 61 in the middle of the third mounting plate 6; the first magnet 31, or electromagnet, is mounted in the magnet mounting hole 62 on the edge of the third mounting plate 6; each electromagnetic control unit 3 has two second magnets 32 (or permanent magnets), which are mounted in two magnet mounting slots on the edges of the first mounting plate 4 and the second mounting plate 5, respectively. As shown in Figure 8a, one permanent magnet of the second magnet 32 ​​is mounted in the magnet mounting slot 41 of the first mounting plate 4; as shown in Figure 8c, the other permanent magnet is mounted in the magnet mounting slot 51 of the second mounting plate 5. The openings of the magnet mounting slots 41 and 51 face the magnet mounting hole 62 and are positioned correspondingly.

[0088] In other embodiments, the two second magnets 32 can be installed on the edges of the first mounting plate 4 and the second mounting plate 5 in other ways, for example, by setting through holes on the edges of the first mounting plate 4 and the second mounting plate 5, or by fitting installation, etc., which is not limited in this application.

[0089] In this embodiment, the magnet mounting hole 62 of the third mounting plate 6 can be a circular through-hole, and the electromagnet mounted in the magnet mounting hole 62 can be a circular electromagnet, with one of its two magnetic poles facing the permanent magnet mounted on the first mounting plate 4 and the other facing the permanent magnet mounted on the second mounting plate 5. The permanent magnets on the first mounting plate 4 and the second mounting plate 5 are circular permanent magnets, and the polarity of the two circular permanent magnets is perpendicular to the reflective lens 2 and opposite, that is, the same magnetic pole is close to the electromagnet. For example, the permanent magnet mounted in the magnet mounting slot 41 of the first mounting plate 4 has its anode facing the electromagnet mounted on the third mounting plate 6 and its cathode facing away from the electromagnet mounted on the third mounting plate 6. Simultaneously, the permanent magnet mounted in the magnet mounting slot 51 of the second mounting plate 5 also has its anode facing the electromagnet mounted on the third mounting plate 6 and its cathode facing away from the electromagnet mounted on the third mounting plate 6.

[0090] In other embodiments, the shape and size of the magnet mounting hole 62 of the third mounting plate 6 can be designed according to the actual shape of the electromagnet, for example, it can be a rectangular hole, etc. It only needs to be ensured that after installation, one pole of the electromagnet faces the permanent magnet of the first mounting plate 4, and the other pole faces the permanent magnet of the second mounting plate 5.

[0091] As shown in Figures 8a to 8c, the first mounting plate 4, the third mounting plate 6, and the second mounting plate 5 are connected by mounting posts 7. The first end 71 of the mounting post 7 is fixedly connected to the edge of the first mounting plate 4. The middle portion 72 of the mounting post 7 extends through the connecting hole 63 on the edge of the third mounting plate 6. The second end 73 of the mounting post 7 is fixedly connected to the edge of the second mounting plate 5. The diameter of the connecting hole 63 is larger than the diameter of the mounting post 7, allowing the third mounting plate 6 to move relative to the mounting post 7 to adjust the distance between the third mounting plate 6 and the first mounting plate 4 and the second mounting plate 5. As shown in Figures 8a and 8c, the first end 71 of the mounting post 7 is fixedly connected to the first mounting hole on the edge of the first mounting plate 4. The second end 73 of the mounting post 7 is fixedly connected to the second mounting hole 52 on the edge of the second mounting plate 5.

[0092] In this embodiment, mounting post 7 can be implemented as a bolt with external threads at both ends and no threads in the middle. Thus, internal threads can be provided in the first and second mounting holes on the edges of first and second mounting plates 4, 5. These threaded holes mate with the external threads at both ends of mounting post 7 to securely connect first and second mounting plates 4, 5. This results in a simple structure and is easy to implement.

[0093] In this embodiment, the first mounting plate 4, the third mounting plate 6, and the second mounting plate 5 are connected by a central, unthreaded mounting post 7. In other embodiments, the connection may be via elastic members. For example, the first mounting plate 4 and the third mounting plate 6 may be connected by a first spring; the second mounting plate 5 and the third mounting plate 6 may be connected by a second spring, and so on. It is sufficient to ensure that the distance between the third mounting plate 6 and the first mounting plate 4 and the second mounting plate 5 is adjustable.

[0094] In some embodiments, there may be multiple first magnets 31 and multiple pairs of second magnets 32. As shown in Figures 8a to 8c, in this embodiment, there are three first magnets 31; the number of magnet mounting holes 62 on the edge of the third mounting plate 6 is the same as the number of first magnets 31, also three, and the magnet mounting holes 62 are evenly distributed circumferentially around the first hollow area 61.

[0095] As shown in Figures 8a to 8c, in this embodiment, the number of second magnets 32 is three pairs, and the number of magnet mounting grooves 41 and magnet mounting grooves 51 on the edges of the first mounting plate 4 and the second mounting plate 5 is the same as the number of second magnets 32, and their positions correspond to the positions of the first magnets 31 respectively.

[0096] As shown in Figures 8a to 8c, in this embodiment, the third mounting plate 6 has three connecting through-holes 63; the first mounting holes 42 of the first mounting plate 4 and the second mounting holes 52 of the second mounting plate 5 are the same number and positioned in a corresponding manner. Furthermore, as shown in Figures 8a to 8c, in this embodiment, the three connecting through-holes 63 of the third mounting plate 6 are positioned in an interlaced manner with the plurality of magnet mounting holes 62; and each first mounting hole 42 of the first mounting plate 4 and each second mounting hole 52 of the second mounting plate 5 are interlaced with each magnet mounting slot 41 and magnet mounting slot 51, respectively.

[0097] In this embodiment, the first mounting plate 4, the third mounting plate 6, and the second mounting plate 5 have the same outer shape. As shown in Figures 8a to 8c, the three mounting plates can have a hexagonal shape, with the corners of the hexagonal shape being used to provide the aforementioned magnet mounting holes, magnet mounting slots, connecting through holes, and mounting holes.

[0098] Furthermore, as shown in FIG8c , since the second mounting plate 5 is mounted toward the shooting area, a second hollow area 53 is provided on the second mounting plate 5. This second hollow area 53 corresponds to the first hollow area 61 in the middle of the third mounting plate 6 and has the same shape and size. This prevents the speckle image reflected by the reflective lens 2 from being blocked by the second mounting plate 5. The portion of the first mounting plate 4 corresponding to the first hollow area 61 of the third mounting plate 6 need not have a hollow area.

[0099] Refer to FIG9 , which is another structural diagram of the connection between the electromagnetic control unit and the reflective lens.

[0100] In this embodiment, a method of binding the permanent magnet and the reflective lens 2 is adopted.

[0101] Specifically, the first magnet 31 fixedly mounted on the edge of the reflective lens 2 is a permanent magnet, and the second magnet 32 ​​is an electromagnet, with two electromagnets. In this embodiment, three mounting plates, similar to the embodiment shown in Figures 8a to 8c, are used to form a three-layer structure to achieve the connection between the electromagnetic control unit and the reflective lens.

[0102] As shown in Figure 9, the only difference between this embodiment and the embodiment shown in Figures 8a to 8c is that the first magnet 31 installed in the magnet mounting hole 62 on the edge of the third mounting plate 6 is a permanent magnet; the second magnet 32 ​​installed in the magnet mounting slot 41 of the first mounting plate 4 and the magnet mounting slot of the second mounting plate 5 (because the magnet mounting slot of the second mounting plate 5 is facing the third mounting plate 6, it is not shown in Figure 9) is an electromagnet (illustrated as a coil in the figure). In actual applications, the installation method of the embodiment shown in Figures 8a to 8c or the installation method of the embodiment shown in Figure 9 can be selected according to actual conditions.

[0103] In this embodiment, the permanent magnet can be a long strip of permanent magnet, and the polarity of the permanent magnet is distributed along the direction from the inside to the outside of the reflective lens 2. In the case where the reflective lens is circular, the polarity of the permanent magnet is distributed along the diameter direction of the reflective lens 2. The magnet mounting hole 62 on the edge of the third mounting plate 6 only exposes one pole of the permanent magnet, and the other pole can be embedded inside the third mounting plate 6. For example: the cathode is exposed in the magnet mounting hole 62, and the anode is embedded inside the third mounting plate 6. One pole of the electromagnet mounted on the first mounting plate 4 faces the pole of the permanent magnet on the third mounting plate 6; one pole of the electromagnet mounted on the second mounting plate 5 faces the pole of the permanent magnet on the third mounting plate 6. When power is supplied to the two electromagnets, it is necessary to ensure that the polarity of the two poles of the permanent magnet facing the third mounting plate 6 is the same.

[0104] It should be noted that the aforementioned structure connecting the electromagnetic control unit and the reflective lens via three mounting plates is only one specific implementation. Based on the above-disclosed embodiments, those skilled in the art will be able to conceive of other implementations. For example, a frame with two opposing side walls can be provided; a mounting plate with an adjustable distance can be provided between the two side walls; the reflective lens and the first magnet can be mounted on the mounting plate, and the second magnet can be mounted on the two side walls; and a hole can be opened in the side wall facing the capture area so that the speckle image projected by the speckle projector can be illuminated by the reflective lens through the side wall opening and reflected by the reflective lens to the capture area of ​​the binocular speckle stereo camera.

[0105] In addition, the speckle projection device provided in the embodiments of the present application may further include a drive module 8 and a housing 9. Referring to Figure 10 , which is a schematic structural diagram of a third embodiment of the speckle projection device provided in the embodiments of the present application, the drive module 8 includes a control circuit 81 and a power supply circuit 82. The power supply circuit 82 is electrically connected to the electromagnets in each electromagnetic control unit 3. The control circuit 81 is configured to send coded instructions to the power supply circuit 82; the coded instructions are used to identify the direction of current passing through each electromagnet, so that the power supply circuit 82 provides forward or reverse current to each electromagnet according to the coded instructions.

[0106] As previously described, the electromagnets of each electromagnetic control unit 3 of the speckle projection device are driven by the forward or reverse current, generating an attractive or repulsive force with the permanent magnet. Thus, the two positions that each electromagnetic control unit 3 can achieve: Position 1 and Position 2, can be represented using binary coding, with 0 and 1 representing Position 1 and Position 2, respectively, that each electromagnetic control unit 3 can achieve. In this embodiment, the two positions that each electromagnetic control unit 3 can achieve are controlled by the forward and reverse currents emitted by the power supply circuit 82. For example, if there are three electromagnetic control units 3, the control circuit 81 can send a total of eight coded instructions, including 000, 001, 010, 011, 100, 101, 110, and 111, to the power supply circuit 82 to achieve eight position control options.

[0107] In this embodiment, the speckle projection device also includes a control circuit 81 and a power supply circuit 82. Simple coded instructions can be used to control each electromagnetic control unit 3, causing the reflective lens 2 to undergo corresponding positional changes. This not only ensures that speckle texture coverage is achieved at various locations within the capture area, thus increasing the coverage area, but also maintains a simple structure and is easy to implement.

[0108] In some embodiments, a housing can be added to the speckle projection device to prevent dust. As shown in Figure 10, the speckle projection device of this embodiment also includes a housing 9. The housing 9 is used to accommodate the various components described above. The bottom of the housing 9 is provided with an opening 91 facing the imaging area. The speckle image reflected by the reflective lens 2 is reflected through the opening 91 to the imaging area of ​​the binocular speckle stereo camera.

[0109] Furthermore, in related art, improvements to the speckle projector are often made to achieve dynamic speckle projection. There are two main approaches: 1. Using multiple speckle projectors, switching or combining them for projection. This approach makes the structure of the binocular speckle stereo camera overly complex and expensive. 2. Using a servo to swing the speckle projector to achieve dynamic speckle projection also results in overly complex and expensive binocular speckle stereo cameras. The speckle projection device provided in the embodiments of the present application utilizes electromagnets to achieve discrete position changes in the reflector. Compared to the aforementioned related art, it also has the advantages of simple structure, ease of implementation, and low cost.

[0110] The present invention also provides a binocular speckle stereo camera, as shown in Figure 11 , which is a schematic structural diagram of the binocular speckle stereo camera provided in the present invention. The binocular speckle stereo camera includes the aforementioned speckle projection device 10 , a camera bracket 11 , and two cameras: camera 12 and camera 13 .

[0111] In this embodiment, cameras 12 and 13 are respectively mounted at opposite ends of a camera support 11, with their fields of view covering the target capture area. A speckle projection device 10 is mounted on the camera support 11 and is capable of reflecting the speckle image projected by the speckle projector 1 toward the target capture area. As shown in FIG11 , the speckle projection device 10 in this embodiment can employ the speckle projection device shown in FIG10 . The detailed structure is described above and will not be repeated here.

[0112] As can be seen from the above embodiments, when the electromagnet in the speckle projection device 10 of the binocular speckle stereo camera is energized, it will generate an attractive force or a repulsive force with the permanent magnet, thereby driving the reflective lens 2 to change its posture. This causes the speckle texture projected at different postures to dynamically change, ensuring that the speckle texture covers different positions in the shooting area, increasing the speckle texture coverage area, improving the image matching accuracy of the binocular speckle stereo camera, and thus improving the depth map acquisition accuracy of the binocular speckle stereo camera.

[0113] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0114] Each embodiment in this specification is described in a related manner. The same or similar parts between the embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments.

[0115] The above description is only a preferred embodiment of the present application and is not intended to limit the scope of protection of the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application are included in the scope of protection of the present application.

Claims

1. A speckle projection device, characterized in that: Applicable to a binocular speckle stereo camera; the device comprises: a speckle projector (1), a reflective lens (2) and one or more electromagnetic control units (3); The reflective lens (2) is arranged on the projection light path of the speckle projector (1) and is used to reflect the speckle image projected by the speckle projector (1) to the shooting area of ​​the binocular speckle stereo camera; Each electromagnetic control unit (3) comprises a first magnet (31) fixedly mounted on the edge of the reflective lens (2) and a second magnet (32) spaced apart from the reflective lens (2); wherein one of the first magnet (31) and the second magnet (32) is a permanent magnet and the other is an electromagnet; so that when the electromagnet is energized, an attractive force or a repulsive force is generated with the permanent magnet, thereby driving the reflective lens (2) to change its posture.

2. The speckle projection device according to claim 1, wherein: The first magnet (31) is a permanent magnet, and the second magnet (32) is an electromagnet; The polarity of the permanent magnet is distributed along the reflective lens (2) from the inside to the outside, and a single magnetic pole extends out of the reflective lens (2) and faces the electromagnet; The electromagnet is a U-shaped electromagnet, and the two poles of the U-shaped electromagnet are respectively spaced apart from the single magnetic pole of the permanent magnet and are symmetrically positioned; or, there are two electromagnets, which are respectively spaced apart from the single magnetic pole of the permanent magnet and are symmetrically positioned.

3. The speckle projection device according to claim 1, wherein: The first magnet (31) is a permanent magnet, and the second magnet (32) includes two electromagnets; the polarity of the permanent magnet is perpendicular to the reflective lens (2); the polarity directions of the two electromagnets are vertically distributed along the reflective lens (2), and the two electromagnets are respectively spaced apart from the two poles of the permanent magnet and are symmetrically positioned; when the two electromagnets are energized, the same polarity faces the permanent magnet.

4. The speckle projection device according to claim 1, wherein: The first magnet (31) is an electromagnet, and the second magnet (32) includes two permanent magnets; the polarity of the electromagnet is perpendicular to the reflective lens (2); the polarity directions of the two permanent magnets are vertically distributed along the reflective lens (2), and the polarities are opposite; the two permanent magnets are respectively spaced apart from the two poles of the electromagnet and are symmetrically positioned.

5. The speckle projection device according to claim 1, wherein: When there are multiple electromagnetic control units (3), the multiple electromagnetic control units (3) are arranged along the circumference of the reflective lens (2).

6. The speckle projection device according to claim 1, wherein: The device further comprises: a first mounting plate (4), a second mounting plate (5) and a third mounting plate (6); wherein the first mounting plate (4) and the second mounting plate (5) are parallel to each other and spaced apart; the third mounting plate (6) is arranged between the first mounting plate (4) and the second mounting plate (5), and the distance between the third mounting plate (6) and the first mounting plate (4) and the second mounting plate (5) is adjustable; The reflective lens (2) is mounted in a first hollow area (61) in the middle of the third mounting plate (6); the first magnet (31) is mounted in a magnet mounting hole (62) at the edge of the third mounting plate (6); There are two second magnets (32), which are respectively installed in two magnet installation slots (41, 51) on the edges of the first installation plate (4) and the second installation plate (5); the two magnet installation slots (41, 51) open toward the magnet installation hole (62) and are positioned correspondingly.

7. The speckle projection device according to claim 6, characterized in that: The first magnet (31) is an electromagnet, and the second magnet (32) is a permanent magnet; The magnet mounting hole (62) of the third mounting plate (6) is a through hole, and one of the two magnetic poles of the electromagnet mounted in the magnet mounting hole (62) faces the permanent magnet mounted on the first mounting plate (4), and the other magnetic pole faces the permanent magnet mounted on the second mounting plate (5); the polarity directions of the permanent magnets of the first mounting plate (4) and the second mounting plate (5) are perpendicular to the reflective lens (2), and the polarities are opposite.

8. The speckle projection device according to claim 6, wherein: The first mounting plate (4), the third mounting plate (6) and the second mounting plate (5) are connected via a mounting post (7); wherein the first end (71) of the mounting post (7) is fixedly connected to the edge of the first mounting plate (4); the middle portion (72) of the mounting post (7) passes through a connecting through hole (63) at the edge of the third mounting plate (6); the second end (73) of the mounting post (7) is fixedly connected to the edge of the second mounting plate (5); and the diameter of the connecting through hole (63) is larger than the diameter of the mounting post (7), so that the third mounting plate (6) can move relative to the mounting post (7) to adjust the distance of the third mounting plate (6) between the first mounting plate (4) and the second mounting plate (5).

9. The speckle projection device according to claim 8, characterized in that: The number of the first magnets (31) is plural; the number of the magnet mounting holes (62) on the edge of the third mounting plate (6) is the same as the number of the first magnets (31), and they are evenly arranged circumferentially around the first hollow area (61); The number of the second magnets (32) is a plurality of pairs, and the number of the magnet mounting slots (41, 51) on the edges of the first mounting plate (4) and the second mounting plate (5) is the same as the number of the second magnets (32), and their positions respectively correspond to the positions of the first magnets (31).

10. The speckle projection device according to claim 9, characterized in that: The first end (71) of the mounting post (7) is fixedly connected to the first mounting hole on the edge of the first mounting plate (4); the second end (73) of the mounting post (7) is fixedly connected to the second mounting hole (52) on the edge of the second mounting plate (5); The number of the connecting through holes (63) of the third mounting plate (6) is multiple; the number of the first mounting holes of the first mounting plate (4) and the number of the second mounting holes (52) of the second mounting plate (5) are both the same as the number of the connecting through holes (63); The positions of the plurality of connecting through holes (63) of the third mounting plate (6) and the plurality of magnet mounting holes (62) are staggered; The first mounting holes of the first mounting plate (4) and the second mounting holes (52) of the second mounting plate (5) are respectively arranged alternately with the magnet mounting slots (41, 51).

11. The speckle projection device according to claim 6, wherein: The first mounting plate (4), the third mounting plate (6) and the second mounting plate (5) have the same appearance; wherein the second mounting plate (5) is mounted toward the shooting area; the second mounting plate (5) is provided with a second hollow area (53); the second hollow area (53) corresponds to the first hollow area (61) in position, and the two have the same shape and size.

12. The speckle projection device according to any one of claims 1 to 11, characterized in that: The device further comprises: a driving module (8); The driving module (8) comprises: a control circuit (81) and a power supply circuit (82); the power supply circuit (82) is electrically connected to the control circuit (81) and the electromagnets in each of the electromagnetic control units (3); The control circuit (81) is used to send a coded instruction to the power supply circuit (82); the coded instruction is used to identify the direction of the current passing through each electromagnet; so that the power supply circuit (82) provides a forward or reverse current to each electromagnet according to the coded instruction; Each electromagnet is driven by the forward or reverse current to generate an attractive force or a repulsive force with the permanent magnet.

13. The speckle projection device according to claim 12, wherein: The device further comprises: a housing (9), wherein the housing (9) is used to accommodate the various components; The bottom of the housing (9) is provided with an opening (91) facing a shooting area; the speckle image reflected by the reflective lens (2) is reflected through the opening (91) to the shooting area of ​​the binocular speckle stereo camera.

14. A binocular speckle stereo camera, characterized in that: include: The speckle projection device (10), the camera bracket (11) and the two cameras (12, 13) according to any one of claims 1 to 13; The two cameras (12, 13) are respectively arranged at two ends of the camera bracket (11), and their lens fields of view cover the target shooting area; The speckle projection device (10) is arranged on the camera bracket (11) and is capable of reflecting the speckle image projected by the speckle projector (1) to the target shooting area.

Images