Optical windows and lidar

Abstract

An embodiment of the present invention provides an optical window and a laser radar. The optical window includes: a first portion for transmitting a transmission light beam; and a second portion for transmitting an echo light beam. In the embodiment of the present invention, the transmission light beam is reflected by a target object to form an echo light beam. Most of the echo light beam is reflected by a reflective unit after passing through the second portion and is received by a receiving unit. Part of the echo light beam is reflected by the reflective unit to the optical window after passing through the second portion and is reflected again by the optical window to form a reflected light beam. Because the first portion and the second portion have an angle in the first direction, the angle between the reflected light beam and the second portion is different from the angle between the majority of the echo light beam and the second portion. As a result, the optical path of the reflected light beam after being reflected by the reflective unit to the receiving unit does not overlap with the optical path of the majority of the echo light beam after being reflected by the reflective unit. The reflected light beam will not be received by the receiving unit, thereby reducing the noise formed on the point cloud and improving the detection effect of the laser radar.

Description

Technical Field

[0001] The present invention relates to the field of laser radar, and in particular to an optical window and a laser radar. Background Art

[0002] LiDAR is a radar system that emits laser beams to detect the position, speed and other characteristic quantities of a target. In autonomous driving, it undertakes important tasks such as curb detection, obstacle recognition, and real-time localization and mapping (SLAM).

[0003] Its working principle is to transmit a detection signal (laser beam) toward a target, then compare the received echo signal reflected from the target with the transmitted signal. After appropriate processing, relevant information about the target, such as target distance, direction, altitude, speed, attitude, and even shape, can be obtained, thereby detecting, tracking, and identifying targets such as cars and pedestrians. It consists of a laser transmitter, an optical receiver, a turntable, and an information processing system. The laser converts electrical pulses into light pulses and transmits them. The optical receiver then converts the light pulses reflected from the target back into electrical pulses.

[0004] The light beam emitted by the laser will produce transmission and reflection effects when passing through the surface of the optical device. At this time, if the reflectivity of the window is high, multiple reflections will occur inside the radar system, forming noise on the point cloud, resulting in poor detection effect of the lidar. Summary of the Invention

[0005] The problem solved by the present invention is to provide an optical window and a laser radar, which can reduce noise formed on a point cloud and improve the detection effect of the laser radar.

[0006] The technical solution of the present invention provides an optical window for a laser radar, which includes: a transmitting unit for providing a transmitting light beam; a reflecting unit for reflecting the transmitting light beam to the optical window, the transmitting light beam is reflected by the target object to form an echo light beam, and the reflecting unit is also used to reflect the echo light beam from the optical window, part of the echo light beam is reflected to the optical window by the reflecting unit, and is reflected again by the optical window to form a reflected light beam; a receiving unit for detecting the echo light beam; the optical window includes: a first part for transmitting the transmitting light beam; a second part for transmitting the echo light beam, the second part is connected to the first part, the arrangement direction from the transmitting unit to the receiving unit is a first direction, the first part and the second part have an angle in the first direction, which is used to separate the reflected light beam from the echo light beam.

[0007] Optionally, the surface of the first part is one or more planes, and the surface of the second part is one or more planes.

[0008] Optionally, the first part is a curved surface, and the second part is a curved surface. The curved surface of the first part protrudes toward the outside of the laser radar, and the curved surface of the second part protrudes toward the inside of the laser radar.

[0009] Optionally, the surface of the first part is a curved surface, the surface of the second part is a curved surface, and the curvature radii of the first part and the second part are different.

[0010] Optionally, the first part is a plane, the second part is a curved surface, and the curved surface of the second part protrudes toward the inside of the laser radar; or, the second part is a plane, the first part is a curved surface, and the curved surface of the first part protrudes toward the outside of the laser radar.

[0011] Optionally, the first part is a plane; or, the first part as a whole is bent toward the outside of the laser radar, including: a plurality of first sub-planes connected in sequence.

[0012] Optionally, the second part is a plane; or, the second part as a whole is bent toward the inside of the laser radar, including: a plurality of second sub-planes connected in sequence.

[0013] Optionally, a projection size of the second part on a vertical plane is larger than a projection size of the first part on a vertical plane, and the vertical plane is perpendicular to the direction of the emitted light beam.

[0014] Optionally, the material of the optical window includes glass or polycarbonate.

[0015] Optionally, the angle between the first portion and the second portion is in the range of 0.1°-10°.

[0016] Optionally, the optical window includes: a blind spot structure for offsetting the emitted light beam in the vertical direction, located at an end of the first part away from the second part, and arranged on the surface of the optical window away from the interior of the laser radar.

[0017] Optionally, the blind spot filling structure is a protrusion formed on the surface of the optical window or a recessed portion formed in the optical window.

[0018] Optionally, the second portion is biased toward the reflecting unit relative to the first portion.

[0019] Correspondingly, the technical solution of the present invention also provides a laser radar, including: a transmitting unit for providing a transmitting light beam; the aforementioned optical window; a reflecting unit for reflecting the transmitting light beam to the optical window, the transmitting light beam is reflected by the target object to form an echo light beam, the reflecting unit is also used to reflect the echo light beam from the optical window, part of the echo light beam is reflected to the optical window through the reflecting unit, and is reflected again by the optical window to form a reflected light beam; a receiving unit for detecting the echo light beam.

[0020] Optionally, the transmitting unit includes multiple lasers, and the receiving unit includes multiple detectors. The detectors correspond to the lasers one-to-one. When the lasers are turned on in sequence in a patrol manner, the corresponding detectors are also turned on in sequence in a patrol manner, and only the echo light beam is detected by the detector that is turned on.

[0021] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0022] The optical window provided in an embodiment of the present invention is such that when the laser radar is working, the transmitted light beam passes through the first part and is emitted toward the target object. The transmitted light beam is reflected by the target object to form an echo light beam. Most of the echo light beam passes through the second part and is reflected by the reflecting unit and then received by the receiving unit. Part of the echo light beam passes through the second part and is reflected by the reflecting unit to the optical window, and is reflected again by the optical window to form a reflected light beam. Because the first part and the second part have an angle in the first direction, the angle between the reflected light beam and the second part is different from the angle between most of the echo light beam and the second part. Therefore, the optical path of the reflected light beam that is reflected by the reflecting unit and is emitted to the receiving unit does not overlap with the optical path of most of the echo light beams that are reflected by the reflecting unit. Therefore, the propagation directions of the reflected light beam and the echo light beam are different. The echo light beam is received by the receiving unit, but the reflected light beam will not be received by the receiving unit, thereby reducing the noise formed on the point cloud and improving the detection effect of the laser radar. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the laser radar emission beam path;

[0024] Figure 2 This is a schematic diagram of the laser radar receiving optical path;

[0025] Figure 3 It is a schematic diagram illustrating only the propagation paths of stray light and stray echo beams;

[0026] Figure 4 1 is a schematic structural diagram of an optical window according to a first embodiment of the present invention;

[0027] Figure 5is a schematic diagram of the optical path of the return light beam of the present invention passing through the second portion of the optical window of the first embodiment;

[0028] Figure 6 2. Schematic diagram of the optical path of the offset emission light beam of the blind spot filling structure in the optical window of the first embodiment of the present invention;

[0029] Figure 7 2 is a schematic structural diagram of a blind spot filling structure in an optical window according to a second embodiment of the present invention;

[0030] Figure 8 1 is a schematic diagram showing the structure of an optical window and a laser radar transmitting unit and a receiving unit according to an embodiment of the present invention;

[0031] Figure 9 is a schematic structural diagram of an optical window according to a second embodiment of the present invention;

[0032] Figure 10 and Figure 11 is a schematic structural diagram of an optical window according to a third embodiment of the present invention;

[0033] Figure 12 is a schematic structural diagram of an optical window according to a fourth embodiment of the present invention;

[0034] Figure 13 is a schematic structural diagram of an optical window according to a fifth embodiment of the present invention;

[0035] Figure 14 2 is a schematic structural diagram of an optical window according to a sixth embodiment of the present invention. DETAILED DESCRIPTION

[0036] As mentioned in the background technology, the high reflectivity of the window will cause multiple reflections inside the lidar system, forming noise on the point cloud. Figures 1 to 3 , analyze the causes of noise on the point cloud.

[0037] like Figure 1 The figure shows a schematic diagram of the laser radar emission beam path.

[0038] The laser radar includes: a transmitting unit A, which is used to transmit a light beam (as shown by a thin solid line), which is used to transmit to a target object E. Specifically, when the transmitted light beam is reflected by a reflector C and transmitted to a window D, the reflected light is divided into a main light beam (as shown by a thin solid line) and stray light (as shown by a dashed line). The main light beam is emitted from the window D toward the target object E, and the stray light is reflected toward the reflector C, and then reflected by the reflector C and emitted from the window D toward the interference object F.

[0039] like Figure 2 The figure shows a schematic diagram of the laser radar receiving optical path.

[0040] The laser radar includes a receiving unit B for receiving a main echo beam formed by the emission beam being reflected by the target E. Specifically, the main echo beam formed after the main beam is emitted toward the target E passes through the window D, is reflected by the reflector C, and is received by the receiving unit B.

[0041] It should be noted that the stray light forms a stray echo beam after it hits the interference object F. The stray echo beam passes through the window D, and after being reflected by the reflector C, window D and reflector C, it follows the same path as the main echo beam and is also received by the receiving unit B.

[0042] Combine Figure 1 and Figure 2 ,refer to Figure 3 , only illustrates the propagation path of stray light and stray echo beam. Specifically, Figure 3 The optical path 1 is the propagation path of the stray light, and the optical path 2 is the propagation path of the stray echo beam.

[0043] Window D in the lidar is a plane window. When the emitted light beam passes through window D, a main beam and stray light are generated. The main beam is reflected by target object E to form a main echo beam, and the stray light is reflected by interference object F to form a stray echo beam. After the stray echo beam within a specific angle passes through window D, the path after reflection by reflector C, window D and reflector C is the same as the path of the main echo beam after reflection by reflector C after passing through window D. Therefore, the stray echo beam and the main echo beam will be received by the receiving unit B together, resulting in noise points on the point cloud.

[0044] In order to solve the above technical problems, an embodiment of the present invention proposes an optical window for a laser radar, which includes: a transmitting unit for providing a transmitting light beam; a reflecting unit for reflecting the transmitting light beam to the optical window, the transmitting light beam is reflected by the target object to form an echo light beam, and the reflecting unit is also used to reflect the echo light beam from the optical window, part of the echo light beam is reflected to the optical window by the reflecting unit, and is reflected again by the optical window to form a reflected light beam; a receiving unit for detecting the echo light beam; it is characterized in that the optical window includes: a first part for transmitting the transmitting light beam; a second part for transmitting the echo light beam, the second part is connected to the first part, the arrangement direction from the transmitting unit to the receiving unit is a first direction, the first part and the second part have an angle in the first direction, which is used to separate the reflected light beam from the echo light beam.

[0045] The optical window provided in an embodiment of the present invention is such that when the laser radar is working, the transmitted light beam passes through the first part and is emitted toward the target object. The transmitted light beam is reflected by the target object to form an echo light beam. Most of the echo light beam passes through the second part and is reflected by the reflecting unit and then received by the receiving unit. Part of the echo light beam passes through the second part and is reflected by the reflecting unit to the optical window, and is reflected again by the optical window to form a reflected light beam. Because the first part and the second part have an angle in the first direction, the angle between the reflected light beam and the second part is different from the angle between most of the echo light beam and the second part. Therefore, the optical path of the reflected light beam that is reflected by the reflecting unit and is emitted to the receiving unit does not overlap with the optical path of most of the echo light beams that are reflected by the reflecting unit. Therefore, the propagation directions of the reflected light beam and the echo light beam are different. The echo light beam is received by the receiving unit, but the reflected light beam will not be received by the receiving unit, thereby reducing the noise formed on the point cloud and improving the detection effect of the laser radar.

[0046] The embodiment of the present invention provides an optical window for laser radar, referring to Figure 4 and Figure 5 , Figure 4 FIG. 1 shows a schematic structural diagram of an optical window according to a first embodiment of the present invention. Figure 5 Schematic diagram showing the optical path of the return light beam passing through the second portion of the optical window of the first embodiment of the present invention.

[0047] The laser radar includes: a transmitting unit 100 (such as Figure 8 As shown in FIG5 , the optical window 500 is used to provide an emission light beam; the reflecting unit 200 is used to reflect the emission light beam to the optical window 500, and the emission light beam is reflected by the target object to form an echo light beam. The reflecting unit 200 is also used to reflect the echo light beam from the optical window 500, and part of the echo light beam is reflected by the reflecting unit 200 to the optical window 500, and is reflected again by the optical window 500 to form a reflected light beam; the receiving unit 300 is used to detect the echo light beam; the optical window is used to transmit the emission light beam provided by the transmitting unit 100 and the echo light beam formed by reflection from the target object.

[0048] The optical window 500 includes: a first part I, used to pass the emission light beam; a second part II, used to pass the echo light beam, the second part II is connected to the first part I, the arrangement direction from the emission unit 100 to the receiving unit 300 is a first direction, and the first part I and the second part II have an angle in the first direction, which is used to separate the reflected light beam from the echo light beam.

[0049] In this embodiment, the first direction is Figure 5As indicated by arrow Y, the arrangement direction from the transmitting unit 100 to the receiving unit 300 is a first direction, and the first portion I and the second portion II form an angle in the first direction. Specifically, the first portion I is configured to transmit the transmitted light beam and corresponds to the transmitting unit 100 ; the second portion II is configured to transmit the echo light beam and corresponds to the receiving unit 300 .

[0050] When the laser radar is working, the emission light beam passes through the first part I and is emitted toward the target object. The emission light beam is reflected by the target object to form an echo light beam. Most of the echo light beam passes through the second part II and is reflected by the reflection unit 200 and is received by the receiving unit 300; part of the echo light beam passes through the second part II and is reflected by the reflection unit 200 to the optical window 500, and is reflected again by the optical window 500 to form a reflected light beam. Because the first part I and the second part II have an angle in the first direction, the angle between the reflected light beam and the second part II is different from the angle between most of the echo light beam and the second part II, so that the optical path of the reflected light beam after being reflected by the reflection unit 200 and emitted to the receiving unit 300 (such as Figure 5 ), and the optical path of most of the echo light beam after being reflected by the reflection unit 200 (as shown in the dashed line Figure 5 The reflected light beam and the echo light beam do not overlap, and thus the propagation directions of the reflected light beam and the echo light beam are different. The echo light beam is received by the receiving unit 300, while the reflected light beam is not received by the receiving unit 300, thereby reducing the noise points formed on the point cloud and improving the detection effect of the lidar.

[0051] In this embodiment, the surfaces of the first portion I and the second portion II of the optical window 500 are both planar. Therefore, the first portion I and the second portion II are simple to manufacture, easy to form, and have wide applicability.

[0052] Specifically, after the echo light beam passes through the second part II, most of the echo light beam is reflected by the reflecting unit 200 and reaches the receiving unit 300, and part of the echo light beam is reflected by the reflecting unit 200 to the second part II, and is reflected again by the second part II to form a reflected light beam. Because the first part I and the second part II have an angle in the first direction, the reflected light beam is separated from the echo light beam.

[0053] Specifically, in this embodiment, the surfaces of the first portion I and the second portion II are both planes. In other embodiments, the surfaces of the first portion I and the second portion II can also be multiple planes.

[0054] In this embodiment, the projection size of the second part II on the vertical plane is larger than the projection size of the first part I on the vertical plane, and the vertical plane is perpendicular to the direction of the emitted light beam.

[0055] In this embodiment, the first portion I of the optical window 500 is used to transmit the emitted light beam. The emitted light beam is a collimated beam, and therefore, the emitted light is more concentrated at the first portion I. Therefore, the projection size of the first portion I on the vertical plane is preferably small, as long as the emitted light can pass through. The second portion II is used to transmit the echo light beam for reception by the receiving unit 300. Because the echo light beam comes from all directions and the light beam diverges, in order to ensure high energy utilization and enable the receiving unit 300 to detect more information, the projection size of the second portion II on the vertical plane is preferably large, so that the echo light beam has a larger light aperture, allowing more echo light beams to pass through the second portion II and be received by the receiving unit 300.

[0056] In this embodiment, the optical window 500 is made of polycarbonate. Polycarbonate has excellent mechanical properties, strong plasticity, strong impact resistance, low density, and low cost. In other embodiments, the optical window can be made of glass, which is widely used in industrial products and has better reliability and lower reflectivity.

[0057] In this embodiment, the optical window 500 is made of polycarbonate and is integrally formed using injection molding. Injection molding is the most commonly used manufacturing process for plastic parts. It can form complex shapes and details, and can precisely adjust the angle between the first portion I and the second portion II to meet design requirements. The injection-molded optical window 500 has an excellent surface finish, which can reduce diffuse reflections from the transmitted light beam and the first portion I, and from the return light beam and the second portion II. This allows more of the transmitted light beam to pass through the first portion I and reach the target, while more of the return light beam passes through the second portion II and is detected by the receiving unit 300. Furthermore, injection molding offers high production efficiency, low cost, and is more economical.

[0058] It should be noted that, in the optical window 500, if the angle α between the first portion I and the second portion II (e.g. Figure 5As shown) is too large, it will affect the assembly space of the transmitting unit and is not conducive to installing the optical window 500 in the laser radar. If the angle α between the first part I and the second part II is too small, the difference between the angle between the reflected light beam and the second part II and the angle between most of the echo light beams and the second part II is small. Even if the optical path of the reflected light beam emitted to the receiving unit after being reflected by the reflecting unit 200 does not coincide with the optical path of most of the echo light beams after being reflected by the reflecting unit 200, the positional distance between the reflected light beam and the echo light beam on the receiving unit 300 is small, and the reflected light beam is received by the receiving unit 300, resulting in the formation of noise on the point cloud of the reflected light beam, thereby causing poor detection effect of the laser radar. In this embodiment, the angle α between the first part I and the second part II (as shown) is too small, the difference between the angle between the reflected light beam and the second part II is small. Figure 5 shown) in the range of 0.1° to 10°.

[0059] Specifically, the first part I is arranged parallel to the vertical plane, and the second part II forms an angle with the vertical plane.

[0060] As an example, the included angles between the second portion II and the vertical plane include 1° and 5°.

[0061] Combine Figure 4 and Figure 5 ,refer to Figure 6 , is a schematic diagram of the optical path of the offset emission light beam of the blind spot filling structure 400 in the optical window 500 of the first embodiment. The optical window 500 includes: the blind spot filling structure 400 (such as Figure 4 or Figure 5 As shown), it is used to offset the emitted light beam in the vertical direction, is located at one end of the first part I away from the second part II, and is arranged on the surface of the optical window 500 away from the inside of the laser radar.

[0062] The blind spot structure 400 is used to offset part of the emitted light beam passing through the first part I in the vertical direction, so that the part of the emitted light beam can detect objects in the blind area in the off-axis optical path, thereby increasing the range reached by the emitted light beam passing through the first part I, thereby reducing the close-range blind area.

[0063] Compared with the case where the blind spot filling structure is located in the first part I close to one end of the second part II, in this embodiment, the blind spot filling structure 400 (such as Figure 4 As shown), it is located at one end of the first part I away from the second part II, so that the emitted light beam can reach a larger range of close-range areas after being deflected by the blind spot filling structure 400, further reducing the close-range blind area.

[0064] Specifically, after the emitted light beam passes through the first portion I without the blind spot filling structure, the farthest point it can reach is n, and the first closest point m it can reach. The range between the farthest point n and the first closest point m is L1. After the emitted light beam passes through the first portion I with the blind spot filling structure 400, the farthest point it can reach is n, and the second closest point p it can reach. The range between the farthest point n and the second closest point p is L2. The farthest points of L2 and L1 are both n. Compared to range L1, range L2 increases the area between the first closest point m and the second closest point p, i.e., the blind spot filling range X. This blind spot filling range X is the area formed by the portion of the emitted light beam that passes through the first portion I and is deflected toward the second portion II by the blind spot filling structure 400, thereby reducing the blind spot at close ranges.

[0065] Compared with the case where the blind spot structure is located on the surface of the optical window close to the interior of the laser radar, in this embodiment, the blind spot structure 400 is arranged on the surface of the optical window 500 away from the interior of the laser radar, which can reduce the proportion of stray light reflected by the blind spot structure 400 into the interior of the laser radar by the transmitted light beam, and also allows more transmitted light beams to pass through the first part I and then directly reach a larger range of close-range areas through the blind spot structure 400.

[0066] It should be noted that the blind spot filling structure 400 can be set according to the energy ratio of the deflected beam to the transmitted beam, for example, it can be set so that the energy of the deflected beam is less than 5% of the energy of the transmitted beam.

[0067] As an example, Figure 6 As shown, the blind spot filling structure 400 is a protrusion formed on the surface of the optical window 500 .

[0068] As another example, Figure 7 5 is a schematic structural diagram of a blind spot filling structure 400 in an optical window according to a second embodiment of the present invention. The blind spot filling structure 400 may also be a recessed portion formed in the optical window 500 .

[0069] refer to Figure 8 , shows a schematic structural diagram of an optical window 500 and a laser radar transmitting unit 100 and a receiving unit 300 according to an embodiment of the present invention.

[0070] In this embodiment, the transmitting unit 100 includes: a plurality of lasers 10, and the plurality of lasers 10 are arranged in two rows in a staggered manner in the vertical direction.

[0071] The transmitting unit 100 is applied to a laser radar and is used to provide a transmitting light beam that is transmitted toward a target object to detect the target object. The transmitting light beam forms an echo light beam after passing through the target object.

[0072] The reflecting unit 200 is used to reflect the emission light beam provided by the emitting unit 100 through the first part I and project it toward the target object, and is also used to reflect the echo light beam through the second part II to facilitate detection by the receiving unit 300.

[0073] In this embodiment, the reflection unit 200 includes a reflection mirror.

[0074] In this embodiment, an angle exists between the surface of the reflector and the emitted light beam. This angle is sufficient to allow the emitted light beam to pass through the first portion I of the optical window 500. The specific angle can be set according to actual application requirements and is not limited to this embodiment. Correspondingly, an angle exists between the surface of the reflector 200 and the echo light beam. This angle is sufficient to allow the echo light beam to pass through the second portion II of the optical window 500, be reflected by the reflector 200, and be detected by the receiving unit 300. The specific angle can be set according to actual application requirements and is not limited to this embodiment.

[0075] Continue to refer Figure 8 In this embodiment, the receiving unit 300 includes a plurality of detectors 30 , which are arranged in two rows in an alternating manner in the vertical direction, and the detectors 30 in the receiving unit 300 correspond one-to-one to the lasers 10 in the transmitting unit 100 .

[0076] When the laser radar is working, the multiple lasers 10 in the transmitting unit 100 are turned on in turn in a patrol manner, and the multiple detectors 30 in the receiving unit 300 are turned on in turn in a patrol manner.

[0077] Specifically, the two columns of lasers 10 in the transmitting unit 100 are arranged in sequence from top to bottom as the first laser, the second laser, and the third laser, and the two columns of detectors 30 in the receiving unit 300 are arranged in sequence from top to bottom as the first detector, the second detector, and the third detector. The first detector corresponds to the first laser, the second detector corresponds to the second laser, and the third detector corresponds to the third laser. When the laser radar is working, the detectors 30 in the receiving unit 300 and the lasers 10 in the transmitting unit 100 work in a patrol coordination manner. Specifically, when the first laser and the first detector are turned on, the second laser and the third laser in the transmitting unit 100 are turned off, and the second detector and the third detector in the detection unit are turned off. When the first laser in the transmitting unit 100 provides an emission beam, it is reflected by the reflector 200, passes through the first part I and is projected toward the target object. The emission beam projected toward the target object generates an echo beam. Since the second part II forms a certain angle with the first part I, when receiving, most of the echo beam passes through the second part II, is reflected by the reflector, and is received by the first detector in the receiving unit 300. The reflected beam formed after the second reflection of the second part II does not coincide with the optical path of most of the echo beam after reflection by the reflector, and thus the propagation directions of the reflected beam and the echo beam are different. The echo beam is received by the receiving unit 300, and the reflected beam will not be received by the receiving unit 300. That is to say, only the echo beam is detected by the first detector that is turned on, reducing the noise formed on the point cloud and improving the detection effect of the lidar.

[0078] refer to Figure 9 , which shows a schematic structural diagram of the optical window according to the second embodiment of the present invention.

[0079] The similarities between this embodiment and the first embodiment are not repeated here. The difference between this embodiment and the first embodiment is that: the first part I is bent toward the outside of the laser radar as a whole, and includes: a plurality of first sub-planes a connected in sequence.

[0080] In an embodiment of the present invention, a plurality of first sub-planes a connected in sequence cause the first part I as a whole to be bent toward the outside of the laser radar, so that after the emission light beam provided by the transmitting unit 100 is reflected by the reflector 200, when passing through the first part I, compared with the case where the first part I is a plane, the noise points formed on the point cloud are reduced, thereby improving the ranging capability.

[0081] Specifically, in this embodiment, the first portion I includes three sequentially connected first sub-planes a. In other embodiments, the number of sequentially connected first sub-planes a may be two or more than three.

[0082] refer to Figure 10 and Figure 11, shows a schematic structural diagram of the optical window according to the third embodiment of the present invention.

[0083] The similarities between this embodiment and the first embodiment are not repeated here. The difference between this embodiment and the first embodiment is that the second part II is bent toward the inside of the laser radar as a whole, and includes: a plurality of second sub-planes b connected in sequence.

[0084] In an embodiment of the present invention, a plurality of sequentially connected second sub-planes b cause the second part II as a whole to bend toward the interior of the laser radar. When the echo light beam passes through the second part II, the noise formed on the point cloud is reduced compared to the case where the second part II is a plane. After being reflected by the reflector 200, it is detected by the receiving unit 300, thereby improving the ranging capability.

[0085] Specifically, as an example, Figure 11 As shown, the second portion II includes two second sub-planes b connected sequentially.

[0086] As another example, Figure 12 As shown, the second portion II includes three second sub-planes b connected in sequence.

[0087] In other embodiments, the number of the second sub-planes b connected sequentially may be more than 3.

[0088] refer to Figure 12 , shows a schematic structural diagram of the optical window according to the fourth embodiment of the present invention.

[0089] The similarities between this embodiment and the first embodiment are not repeated here. The difference between this embodiment and the first embodiment is that the first part I is a curved surface, the second part II is a curved surface, the curved surface of the first part I protrudes to the outside of the laser radar, and the curved surface of the second part II protrudes to the inside of the laser radar.

[0090] The curved surface of the first part I protrudes toward the outside of the laser radar, so that the emission light beam provided by the emitting unit 100, after being reflected by the reflector 200, has a converging effect on the emission light beam when passing through the first part I, so that more emission light beams converge on the target object, so that the target object can generate a stronger echo light beam based on the converged emission light beam, which can improve the ranging capability.

[0091] The curved surface of the second part II protrudes toward the inside of the laser radar. When the echo beam passes through the second part II, it has a converging effect on the echo beam, so that more echo beams are reflected by the reflector 200 and detected by the receiving unit 300, which can improve the distance measurement capability.

[0092] In this embodiment, the first portion I and the second portion II have different curvature radii.

[0093] Most of the echo light beams pass through the second part II and are reflected by the reflector and then received by the receiving unit; part of the echo light beams pass through the second part II and are reflected by the reflector to the optical window in succession, and are reflected again by the optical window 500 to form a reflected light beam. Because the curvature radii of the first part I and the second part II are different, the optical path of the reflected light beam after converging through the second part II is different from the optical path of most of the echo light beams after converging through the second part II. Therefore, the optical path of the reflected light beam after being reflected by the reflector and emitted to the receiving unit 300 does not coincide with the optical path of most of the echo light beams after being reflected by the reflector, and thus the propagation directions of the reflected light beam and the echo light beam are different. The echo light beam is received by the receiving unit 300, and the reflected light beam is not received by the receiving unit 300, thereby reducing the noise formed on the point cloud and improving the detection effect of the lidar.

[0094] refer to Figure 13 , shows a schematic structural diagram of the optical window according to the fifth embodiment of the present invention.

[0095] The similarities between this embodiment and the first embodiment are not repeated here. The difference between this embodiment and the first embodiment is that the first part I is a plane, the second part II is a curved surface, and the curved surface of the second part II protrudes toward the inside of the laser radar.

[0096] The curved surface of the second part II protrudes toward the inside of the laser radar. When the echo beam passes through the second part II, it has a converging effect on the echo beam, so that more echo beams are reflected by the reflector 200 and detected by the receiving unit 300, which can improve the distance measurement capability.

[0097] refer to Figure 14 , shows a schematic structural diagram of the optical window according to the sixth embodiment of the present invention.

[0098] The similarities between this embodiment and the first embodiment are not repeated here. The difference between this embodiment and the first embodiment is that the second part II is a plane, the first part I is a curved surface, and the curved surface of the first part I protrudes toward the outside of the laser radar.

[0099] The curved surface of the first part I protrudes toward the outside of the laser radar, so that the emission light beam provided by the emitting unit 100, after being reflected by the reflector 200, has a converging effect on the emission light beam when passing through the first part I, so that more emission light beams converge on the target object, so that the target object can generate a stronger echo light beam based on the converged emission light beam, which can improve the ranging capability.

[0100] In order to solve the problem of noise points on the point cloud, an embodiment of the present invention further provides a laser radar, including:

[0101] The transmitting unit 100 is used to provide a transmitting light beam; the aforementioned optical window 500, the relevant description of the optical window 500 refers to the aforementioned embodiment and is not repeated here; the reflector 200 is used to reflect the transmitting light beam to the optical window 500, the transmitting light beam is reflected by the target object to form an echo light beam, and the reflector 200 is also used to reflect the echo light beam from the optical window 500, part of the echo light beam is reflected by the reflector 200 to the optical window 500, and is reflected again by the optical window 500 to form a reflected light beam; the receiving unit 300 is used to detect the echo light beam.

[0102] When the laser radar is working, the emission light beam passes through the first part I and is emitted toward the target object. The emission light beam is reflected by the target object to form an echo light beam. Most of the echo light beam passes through the second part II and is reflected by the reflector 200 and is received by the receiving unit 300; part of the echo light beam passes through the second part II and is reflected by the reflector 200 to the optical window 500, and is reflected again by the optical window 500 to form a reflected light beam. Because the first part I and the second part II have an angle in the first direction, the angle between the reflected light beam and the second part II is different from the angle between most of the echo light beam and the second part II, so that the optical path of the reflected light beam to the receiving unit 300 after being reflected by the reflector 200 (such as Figure 5 The light path of the return beam after being reflected by the reflector 200 (shown as the dotted line in the middle) Figure 5 The reflected light beam and the echo light beam do not overlap, and thus the propagation directions of the reflected light beam and the echo light beam are different. The echo light beam is received by the receiving unit 300, and the reflected light beam is not received by the receiving unit 300, thereby reducing the noise points formed on the point cloud and improving the detection effect of the lidar.

[0103] The transmitting unit 100 is applied to a laser radar and is used to provide a transmitting light beam that is transmitted toward a target object to detect the target object. The transmitting light beam forms an echo light beam after passing through the target object.

[0104] In this embodiment, the transmitting unit 100 includes: a plurality of lasers 10 (such as Figure 8 As shown, the multiple lasers 10 are arranged in two rows in a staggered manner in the vertical direction. In other embodiments, the lasers in the emitting unit can also be arranged in a matrix to ensure the uniformity of the emitted light beam. The lasers in the emitting unit can be arranged in a row with multiple columns or multiple rows with multiple columns according to actual functional requirements.

[0105] In this embodiment, the laser 10 is a semiconductor laser, including a vertical cavity surface emitting laser (VCSEL) or an edge emitting laser (EEL).

[0106] The laser 10 can emit laser light at wavelengths of 850 nm, 905 nm, 940 nm, and so on. These wavelengths are outside the visible light range, thus preventing visible light from interfering with target detection. The reflector 200 is used to reflect the transmitted light beam provided by the transmitting unit 100 through the first portion I toward the target, and also to reflect the return light beam that passes through the second portion II for detection by the receiving unit 300.

[0107] In this embodiment, the receiving unit 300 includes a plurality of detectors 30, which are arranged in two columns in a staggered manner in the vertical direction, and the detectors 30 in the receiving unit 300 correspond one-to-one to the lasers 10 in the transmitting unit 100. In other embodiments, the detectors in the receiving unit can also be arranged in a matrix, or the detectors in the receiving unit can be arranged in a row of multiple columns or multiple rows and multiple columns according to actual functional requirements.

[0108] In this embodiment, the detector 30 includes an APD (Avalanche Photo Diode), a silicon photomultiplier (SiPM), or a single photon avalanche diode (SPAD).

[0109] It should be noted that when the lasers 10 are turned on in sequence in a patrol manner, the corresponding detectors 30 are also turned on in sequence in a patrol manner. Only the echo beam is detected by the turned-on detector 30, and the reflected beam does not fall on the detector or falls on the unturned detector 30, so that the reflected beam is not detected.

[0110] In addition, in this embodiment, the lasers 10 in the transmitting unit 100 are in two rows and are arranged in an alternating manner in the vertical direction; the detectors 30 in the receiving unit 300 are in two rows and are arranged in an alternating manner in the vertical direction. When the laser radar is working, one laser in each row of lasers 10 emits a light beam, and the optical paths of the emission light beams emitted by the two lasers 10 are different, so that the two emission light beams are transmitted to the target at different angles. Compared with the case where the lasers in the transmitting unit are in one row and the detectors in the receiving unit are in one row, the two echo light beams formed by reflection from the target can provide more information than one echo light beam, which is beneficial to improving the point cloud density and the detection effect; at the same time, it can improve the resolution in the vertical direction.

[0111] When the laser radar is working, the reflected light beam is reflected by the reflecting unit 200 and then directed to the optical path of the receiving unit 300 (such as Figure 5 The light path of the return beam after being reflected by the reflection unit 200 (shown as the dotted line in the middle) Figure 5The reflected light beam and the echo light beam do not overlap, and thus the propagation directions of the reflected light beam and the echo light beam are different. This is because the laser 10 and the detector 30 are turned on in turn in a patrol manner, and only the echo light beam is detected by the turned-on detector 30, while the reflected light beam does not fall on the detector 30 or falls on the unturned detector 30, so that the reflected light beam is not detected. In other words, the reflected light beam is not received by the detector 30, which reduces the noise formed on the point cloud and can improve the detection effect of the lidar.

[0112] Specifically, the two columns of lasers 10 in the transmitting unit 100 are arranged in sequence from top to bottom as the first laser, the second laser, and the third laser, and the two columns of detectors 30 in the receiving unit 300 are arranged in sequence from top to bottom as the first detector, the second detector, and the third detector. The first detector corresponds to the first laser, the second detector corresponds to the second laser, and the third detector corresponds to the third laser. When the laser radar is working, the detectors 30 in the receiving unit 300 and the lasers 10 in the transmitting unit 100 work in a patrol coordination manner. Specifically, when the first laser and the first detector are turned on, the second laser and the third laser in the transmitting unit are turned off, and the second detector and the third detector in the detection unit are turned off. When the first laser in the transmitting unit 100 provides an emission beam, it is reflected by the reflector 200, passes through the first part I and is projected toward the target object. The emission beam projected toward the target object generates an echo beam. Since the second part II forms a certain angle with the first part I, when receiving, most of the echo beam passes through the second part II, is reflected by the reflector, and is received by the first detector in the receiving unit 300. The reflected beam formed after the second reflection of the second part II does not coincide with the optical path of most of the echo beam after reflection by the reflector, and thus the propagation directions of the reflected beam and the echo beam are different. The echo beam is received by the receiving unit 300, and the reflected beam will not be received by the receiving unit 300. That is to say, only the echo beam is detected by the first detector that is turned on, reducing the noise formed on the point cloud and improving the detection effect of the lidar.

[0113] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope defined by the claims. Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope defined by the claims.

Claims

1. An optical window for a laser radar, the laser radar comprising: A transmitting unit, configured to provide a transmitting light beam; a reflecting unit, configured to reflect the emitted light beam to the optical window, wherein the emitted light beam passes through the optical window and is reflected by a target object to form an echo light beam, and the echo light beam passes through the optical window. The reflecting unit is further configured to reflect the echo light beam that passes through the optical window, wherein a portion of the echo light beam is reflected by the reflecting unit to the optical window and is reflected again by the optical window to form a reflected light beam; a receiving unit, configured to detect the echo light beam; Characterized in that, the optical window comprises: A first portion, configured to transmit the emission light beam; The second part is used to pass through the echo light beam, the second part is connected to the first part, the arrangement direction from the transmitting unit to the receiving unit is the first direction, the first part and the second part have an angle in the first direction, which is used to separate the reflected light beam from the echo light beam, and the second part is biased toward the reflecting unit relative to the first part.

2. The optical window according to claim 1, wherein: The surface of the first portion is one or more planes, and the surface of the second portion is one or more planes.

3. The optical window according to claim 1, wherein: The first part is a curved surface, and the second part is a curved surface. The curved surface of the first part protrudes toward the outside of the laser radar, and the curved surface of the second part protrudes toward the inside of the laser radar.

4. The optical window according to claim 1, wherein: The surface of the first portion is a curved surface, the surface of the second portion is a curved surface, and the first portion and the second portion have different curvature radii.

5. The optical window according to claim 1, wherein: The first portion is a plane, the second portion is a curved surface, and the curved surface of the second portion protrudes toward the interior of the laser radar; Alternatively, the second part is a plane, the first part is a curved surface, and the curved surface of the first part protrudes toward the outside of the laser radar.

6. The optical window according to claim 1, wherein: The first portion is a plane; or, The first part is bent toward the outside of the laser radar as a whole, and includes: a plurality of first sub-planes connected in sequence.

7. The optical window according to claim 1, wherein: The second portion is a plane; or, The second part is bent toward the inside of the laser radar as a whole, and includes: a plurality of second sub-planes connected in sequence.

8. The optical window according to claim 1, wherein: A projection size of the second portion on a vertical plane is larger than a projection size of the first portion on a vertical plane, and the vertical plane is perpendicular to a direction of the emitted light beam.

9. The optical window according to claim 1, wherein: The optical window is made of glass or polycarbonate.

10. The optical window according to claim 1, wherein: An included angle between the first portion and the second portion is in the range of 0.1°-10°.

11. The optical window according to claim 1, wherein: The optical window includes: a blind spot filling structure for offsetting the emitted light beam in the vertical direction, located at an end of the first part away from the second part, and arranged on the surface of the optical window away from the interior of the laser radar.

12. The optical window according to claim 11, wherein: The blind spot filling structure is a protrusion formed on the surface of the optical window or a recessed portion formed in the optical window.

13. A laser radar, characterized in that: include: A transmitting unit, configured to provide a transmitting light beam; The optical window according to any one of claims 1 to 12; a reflecting unit, configured to reflect the emitted light beam to the optical window, wherein the emitted light beam passes through the optical window and is reflected by a target object to form an echo light beam, and the echo light beam passes through the optical window. The reflecting unit is further configured to reflect the echo light beam that passes through the optical window, wherein a portion of the echo light beam is reflected by the reflecting unit to the optical window and is reflected again by the optical window to form a reflected light beam; A receiving unit is used to detect the echo light beam.

14. The laser radar according to claim 13, wherein: The transmitting unit includes multiple lasers, and the receiving unit includes multiple detectors. The detectors correspond to the lasers one by one. When the lasers are turned on in sequence in a patrol manner, the corresponding detectors are also turned on in sequence in a patrol manner. Only the echo light beam is detected by the detector that is turned on.

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