Laser receiving module and laser radar

Abstract

The present invention relates to the field of laser radar detection technology, and more specifically, to a laser receiving module and a laser radar. The laser receiving module includes a housing, in which an optical channel and a first extinction structure are provided; the first extinction structure includes a first extinction channel and a first optical trap connected to the optical channel; the entrance opening size of the first extinction channel is smaller than the exit opening size, and the entrance opening portion gradually and smoothly transitions to the exit opening portion; the first optical trap is provided at the exit opening portion of the first extinction channel and is recessed in the channel wall of the first extinction channel. The laser receiving module and laser radar provided by the present invention can reduce stray light detected by the detector, so that the stray light is less likely to interfere with the detector's detection of the distance and shape of the detected object, thereby improving the detection accuracy.

Description

Technical Field

[0001] The present invention relates to the field of laser radar detection technology, and in particular to a laser receiving module and a laser radar. Background Art

[0002] Laser radar is widely used due to its advantages such as high resolution, strong anti-interference ability and small size. The main light source of laser radar is semiconductor laser. The laser it emits has a certain angle and the energy is relatively divergent. Generally, the light beam is adjusted through a lens to make the emitted light beam into a collimated state. At this time, the light beam energy is strong and the detector can detect the light returned from distant targets.

[0003] However, in existing lidars, while the detector receives the laser beam reflected by the target object, it also receives large-angle ambient stray light and stray light from the transmitting module. The presence of these stray lights will interfere with the lidar's detection of the distance and shape of the detected object, affecting the lidar's detection accuracy.

[0004] In summary, how to overcome the above-mentioned defects of existing lidar is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0005] The purpose of the present invention is to provide a laser receiving module and a laser radar to alleviate the technical problem of low detection accuracy existing in the laser radar in the prior art.

[0006] The laser receiving module provided by the present invention comprises a housing, wherein an optical channel and a first extinction structure are provided in the housing.

[0007] The first extinction structure has a first extinction channel and a first optical trap connected to the optical channel; the entrance opening size of the first extinction channel is smaller than the exit opening size, and gradually and smoothly transitions from the entrance opening to the exit opening; the first optical trap is arranged at the exit opening of the first extinction channel and is recessed in the channel wall of the first extinction channel.

[0008] Preferably, as an implementation method, the channel wall of the first extinction channel has a plurality of first inclined surfaces, and the first inclined surfaces gradually and smoothly transition from the entrance opening portion of the first extinction channel to the exit opening portion; the first optical trap is arranged on the first inclined surface and is recessed in the first inclined surface.

[0009] Preferably, as an implementable embodiment, the channel wall of the first extinction channel has two first inclined surfaces, which are arranged opposite to each other.

[0010] Preferably, as an implementation method, the entrance opening size of the first extinction channel is smaller than the opening size of the optical channel on the entrance side, and the entrance opening of the first extinction channel gradually and smoothly transitions to the channel wall of the optical channel on the entrance side to form a second optical trap.

[0011] Preferably, as an implementable embodiment, the first optical trap is coated with a light-absorbing material or affixed with a light-absorbing film;

[0012] And / or, the second optical trap is coated with a light-absorbing material or affixed with a light-absorbing film.

[0013] Preferably, as an implementable embodiment, a second extinction structure is further provided in the shell, and the second extinction structure has a second extinction channel connected to the optical channel, the inlet opening size of the second extinction channel is smaller than the outlet opening size, and the second extinction channel gradually and smoothly transitions from the inlet opening part to the outlet opening part.

[0014] Preferably, as an implementable embodiment, the channel wall of the second extinction channel has a plurality of second inclined surfaces, and the second inclined surfaces gradually and smoothly transition from the inlet opening portion to the outlet opening portion of the second extinction channel.

[0015] Preferably, as an implementable embodiment, the channel wall of the second extinction channel has two second inclined surfaces, which are arranged opposite to each other.

[0016] Preferably, as an implementation method, the laser receiving module further includes a first lens group and a second lens group, and the first lens group, the first extinction structure, the second lens group and the second extinction structure are arranged in sequence along the propagation direction of the light path.

[0017] Correspondingly, the present invention also provides a laser radar, which includes the above-mentioned laser receiving module.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The laser receiving module provided by the present invention has an optical channel in its shell. After the laser beam reflected by the detected object enters the optical channel in the shell, it can propagate along the optical channel until it is detected and received by the detector.

[0020] A first extinction structure is further provided in the shell. The first extinction channel in the first extinction structure is connected to the above-mentioned optical channel. Since the entrance opening size of the first extinction channel is smaller than the exit opening size, and the first extinction channel gradually and smoothly transitions from the entrance opening to the exit opening, the stray light entering the first extinction channel from the entrance of the first extinction channel will propagate along the channel wall of the first extinction channel toward the exit of the first extinction channel and enter the first optical trap which is located on the exit side of the first extinction channel and is recessed. The energy of the stray light entering the first optical trap can be absorbed by the first optical trap, so that this part of the stray light will not continue to propagate along the optical channel, thereby reducing the stray light propagating to the detector.

[0021] Therefore, the laser receiving module provided by the present invention can reduce the stray light detected by the detector, so that the stray light is less likely to interfere with the detector's detection of the distance and shape of the detected object, thereby improving the detection accuracy.

[0022] The laser radar provided by the present invention includes the above-mentioned laser receiving module, so it has all the advantages of the above-mentioned laser receiving module and has high detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0024] Figure 1 A schematic diagram of a partial structure of a laser radar provided in an embodiment of the present invention;

[0025] Figure 2 A schematic front view of the structure of a laser receiving module provided in an embodiment of the present invention;

[0026] Figure 3 A schematic front view of the structure of the first extinction structure in the laser receiving module provided by an embodiment of the present invention;

[0027] Figure 4 This is a schematic front view of the second extinction structure in the laser receiving module provided by an embodiment of the present invention.

[0028] Description of reference numerals:

[0029] 100-optical channel; 110-axis;

[0030] 200 - first extinction structure; 210 - first extinction channel; 211 - first inclined surface; 220 - first optical trap; 230 - second optical trap;

[0031] 300 - second extinction structure; 310 - second extinction channel; 311 - second inclined surface;

[0032] 400-first lens group; 410-first lens; 420-second lens;

[0033] 500-second lens group;

[0034] 600-reflector. DETAILED DESCRIPTION

[0035] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0036] The present invention will be further described in detail below through specific implementation examples in conjunction with the accompanying drawings.

[0037] See also Figure 1 and Figure 2 This embodiment provides a laser receiving module, which includes a shell, in which an optical channel 100 and a first extinction structure 200 are provided; the first extinction structure 200 has a first extinction channel 210 and a first optical trap 220 connected to the optical channel 100; the inlet opening size of the first extinction channel 210 is smaller than the outlet opening size, and the inlet opening portion gradually and smoothly transitions to the outlet opening portion; the first optical trap 220 is provided at the outlet opening portion of the first extinction channel 210 and is recessed in the channel wall of the first extinction channel 210. The inlet opening of the first extinction channel 210 is the opening of the first extinction channel 210 for laser incidence, and the outlet opening of the first extinction channel 210 is the opening of the first extinction channel 210 for laser emission; as shown in FIG. Figure 2 As shown, the direction indicated by the arrow is the direction of laser propagation.

[0038] After the laser beam reflected by the detected object enters the optical channel 100 in the housing, it can propagate along the optical channel 100 until it is detected and received by the detector. Since the entrance opening size of the first extinction channel 210 is smaller than the exit opening size, and the first extinction channel 210 gradually and smoothly transitions from the entrance opening to the exit opening, the stray light entering the first extinction channel 210 from the entrance of the first extinction channel 210 will propagate along the channel wall of the first extinction channel 210 toward the exit of the first extinction channel 210 and enter the first optical trap 220 that is recessed and located on the exit side of the first extinction channel 210. The energy of the stray light entering the first optical trap 220 can be absorbed by the first optical trap 220, so that this part of the stray light will not continue to propagate along the optical channel 100, thereby reducing the stray light propagating to the detector.

[0039] Therefore, the laser receiving module provided in this embodiment can reduce the stray light detected by the detector, so that the stray light is less likely to interfere with the detector's detection of the distance and shape of the detection object, thereby improving the detection accuracy.

[0040] It should be noted that the cross-sectional shape of the first extinction channel 210 can be circular, rectangular or other shapes. When it is circular, the opening size of the first extinction channel 210 (including the inlet opening size and the outlet opening size) is the opening diameter; when it is rectangular, the opening size of the first extinction channel 210 (including the inlet opening size and the outlet opening size) is the opening length and width size; in fact, the first extinction channel 210 can form a trumpet-shaped structure or a trumpet-shaped structure.

[0041] Specifically, see Figure 2 and Figure 3 The channel wall of the first extinction channel 210 has a plurality of first inclined surfaces 211. The first inclined surfaces 211 gradually and smoothly transition from the entrance opening of the first extinction channel 210 to the exit opening. The first optical trap 220 is disposed on the first inclined surfaces 211 and is recessed in the first inclined surfaces 211. In this way, stray light entering the first extinction channel 210 from the entrance can propagate along the first inclined surfaces 211 toward the exit of the first extinction channel 210 and enter the first optical trap 220 recessed in the first inclined surfaces 211. As a result, the first optical trap 220 can absorb some of the stray light, reducing the amount of stray light that reaches the detector.

[0042] Preferably, the number of the first inclined surfaces 211 can be two, that is, the channel wall of the first matte channel 210 has two first inclined surfaces 211 , which are arranged opposite to each other. This not only achieves a better matte effect but also facilitates processing.

[0043] The two first inclined surfaces 211 can be opposite to each other Figure 2 The axis 110 in the middle is symmetrically arranged. In addition, the angle range of the two first inclined surfaces 211 can be set to 20° to 100°, and the specific angle value can be set according to actual needs.

[0044] The entrance opening size of the first extinction channel 210 is set to be smaller than the channel opening size of the optical channel 100 on the entrance side, and a second optical trap 230 is formed from the entrance opening of the first extinction channel 210 to the channel wall of the optical channel 100 on the entrance side. The second optical trap 230 is used to initially absorb stray light entering the optical channel 100, which can further reduce the stray light propagating to the detector.

[0045] The first extinction channel 210 can be configured as either of the following two structures:

[0046] First, a protruding structure protruding toward the inside of the optical channel 100 can be provided on the housing, and the protruding structure is used as the first extinction channel 210 . This can reduce the number of parts and improve assembly efficiency.

[0047] The second method is to open a slot on the shell and add a part with the above-mentioned first extinction channel 210, and plug the part into the slot. Since the part is an independent structure, the shape requirements of the first extinction channel 210 are relatively low, and the shape of the first extinction channel 210 can be freely selected according to actual needs.

[0048] In the specific structure of the first optical trap 220, a plurality of arc grooves are provided, the shape of the longitudinal section of the arc groove is set to an arc, and the arc grooves are made to correspond one-to-one with the first inclined surface 211. In this way, stray light will enter the arc groove corresponding to the first inclined surface 211 along the first inclined surface 211, and can be reflected back and forth in the arc groove to achieve the purpose of extinction.

[0049] Preferably, a light-absorbing material may be coated or a light-absorbing film may be applied inside the first optical trap 220 to improve the extinction effect of the first optical trap 220 .

[0050] Likewise, a light-absorbing material may be coated or a light-absorbing film may be applied inside the second optical trap 230 to enhance the extinction effect of the second optical trap 230 .

[0051] See also Figure 1 and Figure 2A second extinction structure 300 may also be provided within the housing. The second extinction structure 300 includes a second extinction channel 310 connected to the optical channel 100. The entrance opening of the second extinction channel 310 is set to be smaller than the exit opening, and the second extinction channel 310 is smoothly transitioned from the entrance opening to the exit opening. Therefore, stray light entering the second extinction channel 310 from the entrance will propagate along the channel wall of the first extinction channel 210 toward the exit. That is, the propagation direction of the stray light will deviate from the main propagation direction of the laser beam. This reduces the stray light that reaches the detector. The entrance opening of the second extinction channel 310 is the opening for the laser beam to enter the second extinction channel 310, and the exit opening of the second extinction channel 310 is the opening for the laser beam to exit the second extinction channel 310.

[0052] In fact, part of the stray light entering the second extinction channel 310 will be reflected by the channel wall of the second extinction channel 310 to the surrounding structure and reflected by the surrounding structure, and another part will directly hit the surrounding structure and be reflected by the surrounding structure to the channel wall of the second extinction channel 310. After several reflections, this part of the stray light will disappear. Therefore, the extinction effect of the second extinction channel 310 can be improved, and the stray light propagating to the detector can be further reduced.

[0053] Specifically, see Figure 2 and Figure 4 The channel wall of the second extinction channel 310 has a plurality of second inclined surfaces 311, which gradually and smoothly transition from the entrance opening of the second extinction channel 310 to the exit opening. In this way, the stray light entering the second extinction channel 310 can propagate along the second inclined surfaces 311 in a direction deviating from the main propagation direction of the laser beam.

[0054] Preferably, the second inclined surfaces 311 can be two, that is, the channel wall of the second matte channel 310 has two second inclined surfaces 311 , and the two second inclined surfaces 311 are arranged opposite to each other. In this way, not only a better matte effect can be achieved, but also processing is facilitated.

[0055] Specifically, the included angle between the two second inclined surfaces 311 can be set to range from 30° to 80°, and the specific included angle value can be set according to actual needs.

[0056] The second extinction channel 310 can be configured as either of the following two structures:

[0057] First, a protruding structure protruding toward the inside of the optical channel 100 can be provided on the housing, and the protruding structure can be used as the second extinction channel 310 . This can reduce the number of parts and improve assembly efficiency.

[0058] The second method is to open a slot on the shell and add a part with the above-mentioned second extinction channel 310, and plug the part into the slot. Since the part is an independent structure, the shape requirements of the second extinction channel 310 are relatively low, and the shape of the second extinction channel 310 can be freely selected according to actual needs.

[0059] The number of the above-mentioned first matt structure 200 and the second matt structure 300 can be set as needed, that is, the first matt structure 200 can be set to one or more, and the second matt structure 300 can also be set to one or more. Several first matt structures 200 and several second matt structures 300 are arranged in sequence along the propagation direction of the light path, and the arrangement order can be set as needed.

[0060] In the laser receiving module, several lens groups can also be provided to use the lens groups to converge the laser. The number of lens groups can be optionally set to two groups, namely the first lens group 400 and the second lens group 500. The first lens group 400, the first extinction structure 200, the second lens group 500 and the second extinction structure 300 are arranged in sequence along the propagation direction of the optical path. In this way, the laser beam reflected back by the detected object can pass through the first lens group 400, the first extinction structure 200, the second lens group 500 and the second extinction structure 300 in sequence along the optical channel 100, and finally be received by the detector.

[0061] The first lens group 400 may include two lenses, which are sequentially spaced apart along the light propagation direction. Figure 2 As shown, along the direction of light propagation, the two lenses are respectively a first lens 410 and a second lens 420, and the two lenses are set at an angle, for example, vertically (other angles are also possible), and a reflector 600 is set between the first lens 410 and the second lens 420. In this way, the laser passing through the first lens 410 is incident on the reflector 600 and then changes direction and is incident on the second lens 420, so as to effectively change the direction of laser propagation, thereby shortening the geometric length of the laser receiving module, facilitating the compact design of the laser receiving module and even the entire lidar system. Of course, in addition to this, the first lens group 400 can also be set into other structural forms, for example, the first lens group 400 includes a plurality of first lenses 410 or second lenses 420. When there is more than one lens, they can be set in parallel, which is not limited here.

[0062] It should be noted that, in this embodiment, the second lens group 500 is set up with one lens as an example. In addition, it can also be set up in other structural forms, for example, multiple lenses are set at intervals, multiple lenses are set at an angle, in which case a reflector can be set between adjacent lenses. Of course, multiple lenses can also be set in parallel, which is not limited here.

[0063] See also Figure 1, this embodiment also provides a laser radar, which includes the above-mentioned laser receiving module.

[0064] The laser radar provided in this embodiment includes the above-mentioned laser receiving module, so it has all the advantages of the above-mentioned laser receiving module and has high detection accuracy.

[0065] In summary, embodiments of the present invention disclose a laser receiving module and laser radar that overcome many technical drawbacks of conventional laser radars. These embodiments can reduce stray light detected by the detector, thereby minimizing the amount of stray light that interferes with the detector's ability to detect the distance and shape of an object, resulting in higher detection accuracy.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A laser receiving module, characterized in that: It comprises a housing, in which an optical channel (100) and a first extinction structure (200) are arranged; The first extinction structure (200) comprises a first extinction channel (210) and a first optical trap (220) connected to the optical channel; the inlet opening size of the first extinction channel (210) is smaller than the outlet opening size, and the inlet opening portion gradually and smoothly transitions to the outlet opening portion; the first optical trap (220) is arranged at the outlet opening portion of the first extinction channel (210) and is recessed in the channel wall of the first extinction channel (210); The channel wall of the first extinction channel (210) has a plurality of first inclined surfaces (211), and the first inclined surfaces (211) gradually and smoothly transition from an entrance opening portion of the first extinction channel (210) to an exit opening portion; the first optical trap (220) is arranged on the first inclined surface (211) and is recessed in the first inclined surface (211); The channel wall of the first extinction channel (210) has two first inclined surfaces (211) which are arranged opposite to each other; The entrance opening size of the first extinction channel (210) is smaller than the entrance size of the optical channel (100) on the entrance side, and a smooth transition is gradually formed from the entrance opening of the first extinction channel (210) to the channel wall of the optical channel (100) on the entrance side, forming a second optical trap (230).

2. The laser receiving module according to claim 1, characterized in that: The first optical trap (220) is coated with a light-absorbing material or affixed with a light-absorbing film; And / or, the second optical trap (230) is coated with a light-absorbing material or affixed with a light-absorbing film.

3. The laser receiving module according to claim 1 or 2, characterized in that: A second extinction structure (300) is further provided in the housing. The second extinction structure (300) has a second extinction channel (310) connected to the optical channel (100). The inlet opening size of the second extinction channel (310) is smaller than the outlet opening size, and the second extinction channel (310) gradually and smoothly transitions from the inlet opening to the outlet opening.

4. The laser receiving module according to claim 3, characterized in that: The channel wall of the second light extinction channel (310) has a plurality of second inclined surfaces (311), and the second inclined surfaces (311) gradually and smoothly transition from the inlet opening portion of the second light extinction channel (310) to the outlet opening portion.

5. The laser receiving module according to claim 4, characterized in that: The channel wall of the second extinction channel (310) has two second inclined surfaces (311) which are arranged opposite to each other.

6. The laser receiving module according to claim 3, characterized in that: The laser receiving module further comprises a first lens group (400) and a second lens group (500), wherein the first lens group (400), the first extinction structure (200), the second lens group (500) and the second extinction structure (300) are arranged in sequence along the propagation direction of the light path.

7. A laser radar, characterized in that: A laser receiving module comprising the laser receiving module according to any one of claims 1 to 6.

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