Laser ranging system and vehicle

Abstract

The present disclosure provides a laser ranging system, comprising: a transmitting device, configured to generate a transmitted detection beam that is to be transmitted to a detection region; a receiving device, configured to receive a reflected detection beam reflected by the detection region; and a beam separation device, configured to transmit the transmitted detection beam towards the detection region, and to transmit the reflected detection beam to the receiving device, wherein the beam separation device has a first portion for transmitting the transmitted detection beam and a second portion for transmitting the reflected detection beam, wherein the first portion has, along a first direction transverse to the optical axis of the transmitting device, a first asymmetric geometric shape that is asymmetric relative to a reference axis, wherein the beam separation device is inclined, about a first inclination axis transverse to the optical axis of the transmitting device, relative to the optical axis at a non-zero angle, and the reference axis is parallel to the first inclination axis and passes through the geometric centre of the first asymmetric geometric shape The present disclosure further provides a vehicle.

Description

[0001] 2024PF02934

[0002] Description

[0003] Laser Ranging System and Vehicle

[0004] Technical Field

[0005] The present disclosure relates to a laser ranging system and a vehicle comprising such a laser ranging system.

[0006] Background

[0007] The application of laser ranging systems (such as LiDAR) in vehicles has greatly promoted the development of intelligent driving and vehicle safety, and is mainly used for autonomous driving environment perception, adaptive cruise control, automatic emergency braking, parking assistance, anti-collision systems, etc. Laser ranging systems possess high-precision ranging capability, can detect obstacles around a vehicle in real time, improve driving safety, and assist autonomous driving vehicles in achieving precise positioning and path planning. In addition, laser ranging can also optimise vehicle distance control, improve traffic efficiency, and reduce energy consumption. With the development of information technology, laser ranging systems will become an important technology for intelligent vehicles.

[0008] A co-axial LiDAR system adopts a coaxial design of a transmitting optical path and a receiving optical path, that is, a laser transmitter and a receiver share the same optical channel. This design realises optical path coupling by means of a beam splitting device or a polarisation optical device, and has significant advantages such as high optical efficiency, strong anti-interference capability, compact structure, and high stability, and therefore can be applied in high-precision ranging and autonomous driving.

[0009] Usually, in a co-axial LiDAR system, a region having a symmetrical shape is used at the beam splitting device that realises optical path coupling to transmit the transmitted detection beam emitted by the light source. The larger the size of the region, the greater the optical loss in the receiving optical path, thereby causing 1

[0010] 1003

[0011] 96.7problems such as reducing the signal-to-noise ratio, decreasing the ranging range and precision, and affecting the anti-interference capability of the system. Under such circumstances, it may be necessary to use, in the transmitting optical path, a vertical-cavity surface-emitting laser (VCSEL, Vertical-Cavity Surface-Emitting Laser) having a small divergence angle as the light source, and to use, in the receiving optical path, a single-photon avalanche diode (SPAD, Single-Photon Avalanche Diode) having high sensitivity and fast response capability as the detector. However, vertical-cavity surface-emitting lasers have the problems of insufficient power and limited wavelength, and therefore cannot be applied to longdistance measurement; single-photon avalanche diodes have the problems of high cost and limited long-distance measurement.

[0012] Moreover, usually, in a co-axial LiDAR system, a common beam splitting device that realises optical path coupling may cause optical loss in the receiving optical path, which in turn leads to a reduction in the signal-to-noise ratio. In addition, stray light from the environment entering the receiving optical path also causes the noise in the signal to increase, further reducing the signal-to-noise ratio, and in turn affecting the ranging range and precision, affecting the anti-interference capability of the system. Generally speaking, a separate filter element may be provided in the optical system of the receiving optical path, but this leads to a larger system size and increases the cost.

[0013] Summary

[0014] Therefore, the purpose of the present disclosure is to provide a laser ranging system and a vehicle comprising such a laser ranging system, wherein the portion for transmitting the emitted transmitted detection beam of the beam separation device adopted in the laser ranging system has a shape adapted to the region on which the emitted transmitted detection beam is incident thereon, thereby reducing the optical loss caused to the received transmitted detection beam at the beam separation device, thereby improving the signal-to-noise ratio, increasing the ranging range and precision, enhancing anti-interference capability, improving the system response speed, and reducing dependence on high-sensitivity detectors.The above purpose is achieved by the laser ranging system described below and a vehicle comprising the laser ranging system.

[0015] In one aspect, the present disclosure provides a laser ranging system, comprising: a transmitting device, configured to generate a transmitted detection beam that is to be transmitted to a detection region; a receiving device, configured to receive a reflected detection beam reflected by the detection region; and a beam separation device, configured to transmit the transmitted detection beam towards the detection region, and to transmit the reflected detection beam to the receiving device, wherein the beam separation device has a first portion for transmitting the transmitted detection beam and a second portion for transmitting the reflected detection beam, wherein the first portion has, along a first direction transverse to the optical axis of the transmitting device, a first asymmetric geometric shape that is asymmetric relative to a reference axis, wherein the beam separation device is inclined, about a first inclination axis transverse to the optical axis of the transmitting device, relative to the optical axis at a non-zero angle, and the reference axis is parallel to the first inclination axis and passes through the geometric centre of the first asymmetric geometric shape.

[0016] The laser ranging system according to the present disclosure may further have, individually or in combination, one or more of the following features.

[0017] In one embodiment, the first asymmetric geometric shape of the first portion is adapted to the region on the beam separation device irradiated by the transmitted detection beam.

[0018] In one embodiment, the size of the first portion in a direction parallel to the first inclination axis increases as the distance from the transmitting device increases along a direction parallel to the optical axis.

[0019] In one embodiment, the first asymmetric geometric shape comprises a trapezoid.

[0020] In one embodiment, the first asymmetric geometric shape comprises a pear shape.

[0021] In one embodiment, the beam separation device has, as the first portion, a through hole through which the transmitted detection beam is able to pass, and, asthe second portion, a reflective coating capable of reflecting the reflected detection beam.

[0022] In one embodiment, the beam separation device has, as the first portion, a transparent portion through which the transmitted detection beam is able to be transmitted, and, as the second portion, a reflective coating capable of reflecting the reflected detection beam.

[0023] In one embodiment, the beam separation device has, as the first portion, a reflective coating capable of reflecting the transmitted detection beam, and, as the second portion, a transparent portion through which the reflected detection beam is able to be transmitted.

[0024] In one embodiment, the beam separation device has a filter coating, the filter coating allowing only the reflected detection beam to pass through to reach the receiving device.

[0025] In one embodiment, the laser ranging system further comprises a rotatable beam deflection device, which is configured to deflect the transmitted detection beam from the beam separation device towards the detection region, and to deflect the reflected detection beam from the detection region towards the beam separation device.

[0026] In one embodiment, the beam separation device has, along a first direction transverse to the optical axis of the transmitting device, a second geometric shape, the second geometric shape being adapted to the light trajectory of the reflected detection beam within the field-of-view range of the receiving device.

[0027] In one embodiment, the beam separation device adopted in the laser ranging system in the present disclosure has a filter element, such that there is no need to use a separate filter element in the receiving optical path, thereby achieving a high signal-to-noise ratio while reducing the system size and lowering the cost, thus increasing the ranging range and precision, enhancing anti-interference capability, improving the system response speed, and reducing dependence on high-sensitivity detectors.

[0028] The above purpose is achieved by the laser ranging system described below and a vehicle comprising the laser ranging system.In one aspect, the present disclosure provides a laser ranging system, comprising: a transmitting device, configured to generate a transmitted detection beam that is to be transmitted to a detection region; a receiving device, configured to receive a reflected detection beam reflected by the detection region; and a beam separation device, configured to transmit the transmitted detection beam towards the detection region, and to transmit the reflected detection beam to the receiving device, wherein the beam separation device has a filter element, the filter element allowing only light beams having wavelengths within a wavelength band corresponding to the reflected detection beam to pass through to reach the receiving device.

[0029] The laser ranging system according to the present disclosure may further have, individually or in combination, one or more of the following features.

[0030] In one embodiment, the filter element has a bandwidth smaller than the full width at half maximum of the transmitted detection beam or the reflected detection beam.

[0031] In one embodiment, the beam separation device comprises a single beam splitter, and the filter element is a filter coating provided on the beam splitter.

[0032] In one embodiment, the beam splitter has a substrate, a through hole through which the transmitted detection beam is able to pass is provided on the substrate, and the filter coating is provided on the side of the substrate facing the receiving device and / or on the side facing the transmitting device and covers the region of the substrate other than the through hole.

[0033] In one embodiment, the beam splitter has a substrate, the substrate has at least a portion through which the transmitted detection beam is able to be transmitted, and the filter coating is provided on the side of the substrate facing the receiving device and / or on the side facing the transmitting device, and covers the region of the substrate other than the portion.

[0034] In one embodiment, the beam splitter has a substrate through which the reflected detection beam is able to be transmitted and a reflective coating, which is provided on the side of the substrate facing the transmitting device and is capable of reflecting the transmitted detection beam, and the filter coating is provided onthe side of the substrate facing the receiving device, and / or is provided on the side facing the transmitting device and covers the region of the substrate other than the reflective coating.

[0035] In one embodiment, an anti-reflection coating is provided on the side of the beam splitter facing the transmitting device and / or on the side facing the receiving device.

[0036] In one embodiment, a light-absorbing coating is provided on the side of the substrate facing the transmitting device.

[0037] In one embodiment, the portion of the beam separation device for transmitting the transmitted detection beam has a geometric shape adapted to the projection region of the transmitted detection beam on the beam separation device.

[0038] In one embodiment, the laser ranging system further comprises a rotatable beam deflection device, which is configured to deflect the transmitted detection beam from the beam separation device towards the detection region, and to deflect the reflected detection beam from the detection region towards the beam separation device.

[0039] In another aspect, the present disclosure further provides a vehicle, which comprises the laser ranging system as described above.

[0040] Brief Description of the Drawings

[0041] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings of the embodiments of the present disclosure will be briefly introduced below. Note that the drawings are only used to show some embodiments of the present disclosure, rather than limiting all embodiments of the present disclosure. In the drawings:

[0042] Fig. la shows a schematic diagram of a laser ranging system according to one embodiment of the present disclosure.

[0043] Fig. lb shows a schematic cross-sectional view of a beam separation device of a laser ranging system according to one embodiment of the present disclosure.

[0044] Fig. 1c shows an enlarged schematic plan view of a beam separation device of a laser ranging system according to one embodiment of the present disclosure.Fig. Id shows an enlarged schematic plan view of a beam separation device of a laser ranging system according to one embodiment of the present disclosure.

[0045] Fig. 2a shows a schematic diagram of a laser ranging system according to one embodiment of the present disclosure and a beam separation device therein, wherein the drawing shown on the right side is an enlarged schematic plan view of the beam separation device.

[0046] Fig. 2b shows a schematic diagram of a laser ranging system according to one embodiment of the present disclosure and a beam separation device therein, wherein the drawing shown on the right side is an enlarged schematic plan view of the beam separation device.

[0047] Fig. 3a shows a schematic diagram of a laser ranging system according to one embodiment of the present disclosure.

[0048] Fig. 3b shows a schematic cross-sectional view of a beam separation device of a laser ranging system according to one embodiment of the present disclosure.

[0049] Fig. 3c shows an enlarged schematic plan view of a beam separation device of a laser ranging system according to one embodiment of the present disclosure.

[0050] Fig. 3d shows an enlarged schematic plan view of a beam separation device of a laser ranging system according to one embodiment of the present disclosure.

[0051] Fig. 4 shows a schematic diagram of a vehicle according to one embodiment of the present disclosure.

[0052] Fig. 5a shows a schematic diagram of a laser ranging system according to one embodiment of the present disclosure.

[0053] Fig. 5b shows an enlarged schematic cross-sectional view of a beam separation device of a laser ranging system according to one embodiment of the present disclosure, wherein the propagation of the reflected detection beam is schematically shown using straight lines with arrows.

[0054] Fig. 5c shows an enlarged schematic cross-sectional view of a beam separation device of a laser ranging system according to one embodiment of the present disclosure, wherein the propagation of the reflected detection beam is schematically shown using straight lines with arrows.

[0055] Fig. 5d shows an enlarged schematic cross-sectional view of a beamseparation device of a laser ranging system according to one embodiment of the present disclosure, wherein the propagation of the reflected detection beam is schematically shown using straight lines with arrows.

[0056] Fig. 6a shows a schematic diagram of a laser ranging system according to another embodiment of the present disclosure.

[0057] Fig. 6b shows an enlarged schematic cross-sectional view of a beam separation device of a laser ranging system according to another embodiment of the present disclosure, wherein the propagation of the reflected detection beam is schematically shown using straight lines with arrows.

[0058] Fig. 6c shows an enlarged schematic cross-sectional view of a beam separation device of a laser ranging system according to another embodiment of the present disclosure, wherein the propagation of the reflected detection beam is schematically shown using straight lines with arrows.

[0059] Fig. 6d shows an enlarged schematic cross-sectional view of a beam separation device of a laser ranging system according to another embodiment of the present disclosure, wherein the propagation of the reflected detection beam is schematically shown using straight lines with arrows.

[0060] Fig. 7a shows a schematic diagram of a laser ranging system according to yet another embodiment of the present disclosure.

[0061] Fig. 7b shows an enlarged schematic cross-sectional view of a beam separation device of a laser ranging system according to yet another embodiment of the present disclosure.

[0062] Fig. 7c shows an enlarged schematic cross-sectional view of a beam separation device of a laser ranging system according to yet another embodiment of the present disclosure.

[0063] Fig. 7d shows an enlarged schematic cross-sectional view of a beam separation device of a laser ranging system according to yet another embodiment of the present disclosure.

[0064] Detailed Embodiments

[0065] In order to make the purposes, technical solutions, and advantages of thetechnical solutions of the present disclosure clearer, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of the specific embodiments of the present disclosure. The same reference numerals in the drawings represent the same components. It should be noted that the described embodiments are some embodiments of the present disclosure, rather than all embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by those ordinarily skilled in the art without creative effort fall within the scope of protection of the present disclosure.

[0066] Unless otherwise defined, the technical terms or scientific terms used herein shall have the ordinary meanings understood by persons of ordinary skill in the art to which the present disclosure pertains. The words “first”, “second”, and similar words used in the description and claims of the patent application of the present disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Likewise, similar words such as “a” or “one” do not necessarily indicate a numerical limitation. Words such as “comprising”, “including”, or “having” and the like mean that the elements or objects appearing before that word encompass the elements or objects listed after that word and equivalents thereof, without excluding other elements or objects. Words such as “connected” or “communicated” and the like are not limited to the physical or mechanical connection or communication shown in the drawings, but may include equivalent connection or communication thereto, whether direct or indirect. “Upper”, “lower”, “left”, “right”, and the like are only used to indicate relative positional relationships, and when the absolute position of the described object changes, the relative positional relationship may also change correspondingly.

[0067] Various embodiments of the laser ranging system for a vehicle according to the embodiments of the present disclosure are described in detail below by referring to Figs. 1 to 4. Figs, la, 2a-2b, and 3a respectively show three different forms of laser ranging systems. According to some embodiments, the laser ranging system as described in the present disclosure may use the time-of-flight method (ToF) to carry out distance measurement. However, the present disclosure is notlimited to what is shown in the drawings and disclosed herein, and appropriate modifications or improvements made on the basis of the systems shown in the drawings and disclosed herein shall also be included within the scope of protection of the present disclosure.

[0068] As shown in Figs, la, 2a-2b, and 3a, the laser ranging system according to the present disclosure may comprise a transmitting device 1, a receiving device 2, and a beam separation device 3.

[0069] The transmitting device 1 is configured to generate a transmitted detection beam 5 that is to be transmitted to the detection region 4. As shown in Fig. la, the transmitting device 1 may comprise a light source 15 and a transmitting optical system 17. The light beam emitted from the light source 15 is collimated and shaped via the transmitting optical system 17, for example, reducing the beam divergence angle and producing a light beam of a special shape, thereby forming a suitable transmitted detection beam 5. For example, the light source 15 may be a laser diode (LD) or a fibre laser. The transmitting optical system 17 may also be referred to as a laser shaping optical system, which may comprise at least one lens, as shown in Fig. la, or may comprise at least one reflector, or a combination of a lens and a reflector. It should be noted that the light rays in the transmitting device 1 shown in Fig. la are merely schematic and do not represent the actual situation. The transmitted detection beam 5 generated by the transmitting device 1 may have a relatively small cross-sectional area, the cross-sectional area being the cross-sectional area on a plane perpendicular to the optical axis 20 of the transmitting device 1.

[0070] The detection region 4 is an object or living creature in the surrounding environment of the vehicle, and the transmitted detection beam irradiated thereon undergoes diffuse reflection, a portion of the reflected transmitted detection beam returning to the laser ranging system along the path of the transmitted detection beam 5, and is referred to herein as the reflected detection beam, or may also be referred to for short as the reflected beam.

[0071] The receiving device 2 is configured to receive the reflected detection beam 6 reflected by the detection region 4. As shown in Fig. la, the receiving device 2may comprise a detector 16 and a receiving optical system 18. For example, the detector 16 may be a photodiode, an avalanche photodiode, a single-photon avalanche diode, a photomultiplier tube, or the like. In some cases, it may also be a complementary metal oxide semiconductor (CMOS) image sensor, a charge-coupled device (CCD) image sensor, or the like. The receiving optical system 18 may be an optical lens having a large aperture and a high transmission rate, and may comprise at least one lens, as shown in Fig. la, or may comprise at least one reflector, or a combination of a lens and a reflector. It should be noted that the light rays in the receiving device 2 shown in Fig. la are merely schematic and do not represent the actual situation. It can be seen from Fig. la that, compared with the transmitted detection beam 5, the reflected detection beam 6 has a larger cross-sectional area, which is usually determined by the beam separation device 3. This ensures that a sufficient amount of light can be detected.

[0072] The beam separation device 3 is configured to transmit the transmitted detection beam 5 towards the detection region 4, and to transmit the reflected detection beam 6 to the receiving device 2. As used herein, “transmit” includes transmission and reflection, as the case may be.

[0073] As can be seen in conjunction with Figs, lb, 2a-2b, and 3b, the beam separation device 3 has a first portion 7 for transmitting the transmitted detection beam 5 and a second portion 8 for transmitting the reflected detection beam 6.

[0074] A cross-sectional view of the beam separation device 3 is shown in Fig. lb, wherein a straight line with an arrow indicates the direction Z parallel to the optical axis 20 of the transmitting device 1 (or coincident therewith), which may also be referred to as the propagation direction of the transmitted beam. A planar view of the beam separation device 3 may be as shown in Fig. 1c, in which a first direction X transverse to (for example, perpendicular to) the optical axis 20 is schematically shown.

[0075] The first portion 7 of the beam separation device 3 for transmitting the transmitted detection beam 5 has a first asymmetric geometric shape in a first direction transverse to the optical axis of the transmitting device 1 , for example, the first asymmetric geometric shape of the first portion 7 shown in Fig. 1c in thefirst direction X transverse to the optical axis 20.

[0076] The beam separation device 3 is inclined relative to the optical axis 20 at a non-zero angle a about a first inclination axis transverse to (for example, perpendicular to) the optical axis 20 of the transmitting device 1. For example, the non-zero angle a may be 45°. In this case, the optical axis 20 of the transmitting device 1 and the optical axis of the receiving device 2 are perpendicular to each other. Of course, other angles are also possible, it being only necessary to correspondingly modify the optical axis of the receiving device 2 so as to match that angle. In the case where the beam separation device 3 is inclined relative to the optical axis 20 at a non-zero angle a , the beam separation device 3 may have a central axis that forms a non-zero angle a relative to the optical axis 20. Fig. 1c shows this central axis as 7c, which passes through the geometric centre of the first asymmetric geometric shape of the first portion 7.

[0077] According to some embodiments, the first asymmetric geometric shape is asymmetric relative to a reference axis, wherein the reference axis is perpendicular to the first inclination axis and passes through the geometric centre of the first asymmetric geometric shape. For example, the reference axis 7b shown in Fig. 1c is parallel to the first inclination axis (and may also coincide with the first inclination axis) and passes through the geometric centre 7a of the first asymmetric geometric shape, and is also perpendicular to the central axis 7c, wherein the first portion 7 may have, for example, the trapezoid shape shown in Fig. 1c, and is asymmetric relative to the reference axis 7b. According to some embodiments, the first asymmetric geometric shape being asymmetric relative to the reference axis means that the two parts of the first asymmetric geometric shape divided by the reference axis have different geometric shapes, for example, in the first portion 7 shown in Fig. 1c, the part of the first portion 7 below the reference axis 7b is wider than the part of the first portion 7 above the reference axis 7b.

[0078] It should be understood that the first portion 7 for transmitting the transmitted detection beam 5 of the beam separation device 3 shown in Fig. 1c is merely schematic, and the shape of the first portion 7 may be other shapes that are asymmetric relative to the above reference axis.For example, in Fig. Id, the reference axis 7b shown in Fig. 1c is parallel to the first inclination axis (and may also coincide with the first inclination axis) and passes through the geometric centre 7a of the first asymmetric geometric shape, and is also perpendicular to the central axis 7c, wherein the first portion 7 may have, for example, the pear shape shown in Fig. 1c, and is asymmetric relative to the reference axis 7b. The “pear shape” described herein is a contour similar to that of a pear fruit, the features thereof including, for example: the contour line from top to bottom is a continuous curve, and the curvature of the curve gradually changes from top to bottom (for example, the curvature of the contour line gradually increases from top to bottom, or the curvature of the contour line gradually decreases from top to bottom).

[0079] Through the asymmetric design of the first portion of the beam separation device for transmitting the transmitted detection beam, the optical loss of the reflected detection beam can be reduced, so that, compared with the conventional design of a symmetrical shape, more reflected detection beams can enter the receiving device, and in turn the signal-to-noise ratio of the entire system can be improved, the ranging range and precision can be increased, the anti-interference capability can be enhanced, the system response speed can be improved, and dependence on high-sensitivity detectors can be reduced. For example, the system of the present disclosure can provide sufficient optical signals for a single-photon avalanche diode, such that it can be applied to long-distance measurement.

[0080] Specifically, in a laser ranging system, the beam separation device is usually inclined relative to the optical axis of the transmitting device, causing the region where the transmitted detection beam actually irradiates on the beam separation device to be asymmetric (for example, the size of the first portion in the direction parallel to the first inclination axis increases as the distance from the transmitting device increases along the direction parallel to the optical axis). However, for a beam separation device having a first portion of a traditional symmetrical design, this will cause the geometric shape of the first portion not to match the region where the transmitted detection beam irradiates on the beam separation device, thereby causing the region of the second portion on the beam separation device fortransmitting the reflected detection beam to correspondingly decrease, and further causing an optical loss of the reflected detection beam.

[0081] As shown in Figs. Ic-ld, 2a-2b, and 3c-3d, the geometric shape of the first portion 7 is adapted to the region where the transmitted detection beam 5 irradiates on the beam separation device 3. The “adapted” herein includes the cases of complete correspondence and approximate correspondence. According to some embodiments, the geometric shape of the first portion 7 being adapted to the region which the transmitted detection beam 5 irradiates on the beam separation device 3 means that the geometric shape of the first portion 7 highly matches the contour of the irradiation region formed by the transmitted detection beam 5 on the beam separation device 3, so as to make the geometric shape of the first portion 7 as close as possible to the irradiation region formed by the transmitted detection beam 5 on the beam separation device 3. According to some embodiments, the geometric shape of the first portion 7 may be determined based on the irradiation region formed by the transmitted detection beam 5 on the beam separation device 3.

[0082] For example, when the cross section of the transmitted detection beam 5 perpendicular to the optical axis 20 of the transmitting device 1 is circular, the geometric shape of the first portion 7 may be a pear shape along the direction perpendicular to the light propagation direction (that is, the optical axis), which may be similar to an elongated deformed circle. For example, when the cross section of the transmitted detection beam 5 perpendicular to the optical axis 20 of the transmitting device 1 is square, the geometric shape of the first portion 7 may be the trapezoid shown in the figure. When the cross section of the transmitted detection beam 5 is circular, the geometric shape of the first portion 7 may also be a trapezoid, which is a case of approximate correspondence, reducing optical loss as much as possible.

[0083] As shown in Figs, la, lb, 1c, and Id, the beam separation device 3 has, as the first portion 7, a through hole 9 through which the transmitted detection beam 5 is able to pass, and, as the second portion 8, a reflective coating 10 capable of reflecting the reflected detection beam 6. For example, the beam separation device 3 is a single coated beam splitter, as shown in Fig. lb, and the beam splitter has asubstrate 30 and a reflective coating 10 coated on the substrate 30, and the through hole 9 is formed through the substrate 30 and the reflective coating 10.

[0084] The term “pass” herein includes the situation where, after the light beam interacts with an object, the light beam can continue to propagate, that is, it includes both transmission of the light beam through the object and reflection of the light beam on the object, wherein, whether by transmission or reflection, the light beam energy continues to propagate in some manner, rather than being completely absorbed or scattered by the object. Therefore, the light beam “passing” through an object may be understood as meaning that, after the light beam interacts with the object, at least part of the light beam energy is still emitted from the object.

[0085] A cross-sectional view of the beam separation device 3 is shown in Fig. lb, wherein a straight line with an arrow indicates the direction Z parallel to the optical axis 20 of the transmitting device 1 (or coincident therewith), which may also be referred to as the propagation direction of the transmitted beam. A planar view of the beam separation device 3 may be as shown in Fig. 1c, in which a first direction X transverse to (for example, perpendicular to) the optical axis 20 is schematically shown. More precisely, Fig. 1c shows the side on which the reflected detection beam 6 reflected by the beam splitter in Figs, la and lb is incident. In Fig. la, the first direction X is perpendicular to the plane of the paper and directed inwards.

[0086] The size of the through hole 9 as the first portion 7 in the direction X parallel to the first inclination axis increases as the distance from the transmitting device 1 increases along the direction of light propagation parallel to the optical axis 20 (that is, along the direction Z).

[0087] For example, the through hole 9 as the first portion 7 may have a trapezoid shape. In Fig. 1c, the upper side of the trapezoid is shorter than the lower side of the trapezoid. Along the optical path, the transmitted detection beam 5 first irradiates the upper side, and then irradiates the lower side. Compared with the square through hole in the prior art having a side length equal to the length of the lower side in Fig. 1c, the trapezoid through hole of the present disclosure has a smaller area, and therefore the proportion of the reflective coating 10 in the beam separation device is higher, so that more reflected detection beams 6 are reflectedinto the receiving device 2.

[0088] As another example, the through hole 9 as the first portion 7 may have a pear shape. In Fig. Id, the upper part of the pear shape is narrower than the lower part of the pear shape. Along the optical path, the transmitted detection beam 5 first irradiates the upper part, and then irradiates the lower part. Compared with the circular through hole in the prior art, the pear-shaped through hole of the present disclosure has a smaller area, and therefore the proportion of the reflective coating 10 in the beam separation device is higher, so that more reflected detection beams 6 are reflected into the receiving device 2.

[0089] Therefore, the laser ranging system shown in Fig. la has a higher signal-to-noise ratio, a larger ranging range, higher precision, stronger anti-interference capability, and a higher response speed.

[0090] As shown in Figs. 2a-2b, in another example, the receiving device 2 may be arranged on the lower side, opposite to that shown in Fig. la. In addition, in Figs.

[0091] 2a-2b, the beam separation device 3 has, as the first portion 7, a transparent portion 11 through which the transmitted detection beam 5 is able to be transmitted, and, as the second portion 8, a reflective coating 12 capable of reflecting the reflected detection beam 6. For example, the beam separation device 3 may also be a single coated beam splitter, as shown in Figs. 2A-2b, and the beam splitter has a substrate 30 and a reflective coating 12 coated on the substrate 30, the reflective coating 12 has an opening, and the transparent portion 11 of the substrate 30 corresponding or aligned with the opening forming the first portion 7.

[0092] The beam separation device 3 is likewise arranged relative to the optical axis 20 at a non-zero angle of 45° about a first inclination axis transverse to (for example, perpendicular to) the optical axis 20 of the transmitting device 1. The size of the transparent portion 11 as the first portion 7 in the direction X parallel to the first inclination axis increases as the distance from the transmitting device 1 increases along the direction parallel to the optical axis 20. The direction parallel to the optical axis is the horizontal direction in the left-hand drawing in Figs. 2a-2b, and the first direction X transverse to (for example, perpendicular to) the optical axis is directed perpendicularly into the plane of the paper in the left-hand drawingin Figs. 2a-2b, and vertically upwards in the right-hand drawing in Figs. 2a-2b. For example, the transparent portion 11 as the first portion 7 may have a trapezoid shape. In Fig. 2a, the upper side of the trapezoid is longer than the lower side of the trapezoid. Referring to the dashed line in Fig. 2a, along the optical path, the transmitted detection beam 5 first irradiates the lower side, and then irradiates the upper side. Compared with the square transparent portion in the prior art having a side length equal to the length of the upper side of the trapezoid shown in Fig. 2a, the trapezoid transparent portion of the present disclosure has a smaller area, and therefore the proportion of the reflective coating is higher, so that more reflected detection beams 6 are reflected into the receiving device 2.

[0093] For example, the transparent portion 11 as the first portion 7 may have a pear shape. In Fig. 2b, the upper part of the pear shape is wider than the lower part of the pear shape. Referring to the dashed line in Fig. 2b, along the optical path, the transmitted detection beam 5 first irradiates the lower part, and then irradiates the upper part. Compared with the circular transparent portion in the prior art, the pear-shaped transparent portion of the present disclosure has a smaller area, and therefore the proportion of the reflective coating is higher, so that more reflected detection beams 6 are reflected into the receiving device 2.

[0094] Therefore, the laser ranging system shown in Figs. 2a-2b has a higher signal-to-noise ratio, a larger ranging range, higher precision, stronger anti-interference capability, and a higher response speed.

[0095] As shown in Fig. 3a, in another example, the positions of the transmitting device 1 and the receiving device 2 are interchanged, that is, the transmitted detection beam 5 emitted by the transmitting device 1 is reflected by the beam separation device 3 towards the detection region, and the reflected detection beam 6 reflected by the detection region is transmitted through the beam separation device 3 and then received by the receiving device 2. The beam separation device 3 has, as the first portion 7, a reflective coating 13 capable of reflecting the detection beam 5 and, as the second portion 8, a transparent portion 14 through which the reflected detection beam 6 is able to be transmitted. For example, the beam separation device 3 may also be a single coated beam splitter, as shown inFig. 3a, the beam splitter having a transparent substrate 30 and a reflective coating 13 coated on a portion of the substrate 30. The reflective coating 13 may be applied by means of a conventional coating process. The transparent portion 14 is the part of the substrate 30 other than the region covered by the reflective coating 13.

[0096] The beam separation device 3 is likewise arranged relative to the optical axis 20 at a non-zero angle of 45° about a first inclination axis transverse to (for example, perpendicular to) the optical axis 20 of the transmitting device 1. The size of the reflective coating 13 as the first portion 7 in the direction X parallel to the first inclination axis increases as the distance from the transmitting device 1 increases along the direction Z parallel to the optical axis 20. The direction Z parallel to the optical axis is the vertically downward direction shown in Figs. 3a and 3b, and the first direction X transverse to (for example, perpendicular to) the optical axis is directed perpendicularly into the plane of the paper in Fig. 3a.

[0097] For example, the reflective coating 13 as the first portion 7 may have a trapezoid shape. In Fig. 3c, the upper side of the trapezoid is shorter than the lower side of the trapezoid. Along the optical path, the transmitted detection beam 5 first irradiates the upper side, and then irradiates the lower side. The trapezoid reflective coating 13 of the present disclosure has a smaller area, and therefore it causes less blocking of the reflected transmitted detection beam 6, such that more of the reflected transmitted detection beam 6 can be transmitted through the substrate 30 to reach the receiving device 2. Therefore, the laser ranging system shown in Fig.

[0098] 3a has a higher signal-to-noise ratio, a larger ranging range, higher precision, stronger anti-interference capability, and a higher response speed.

[0099] For example, the reflective coating 13 as the first portion 7 may have a pear shape. In Fig. 3d, the upper part of the pear shape is narrower than the lower part of the pear shape. Along the optical path, the transmitted detection beam 5 first irradiates the upper part, and then irradiates the lower part. The pear-shaped reflective coating 13 of the present disclosure has a smaller area, and therefore it causes less blocking of the reflected transmitted detection beam 6, such that more of the reflected transmitted detection beam 6 can be transmitted through the substrate 30 to reach the receiving device 2. Therefore, the laser ranging systemshown in Fig. 3a has a higher signal-to-noise ratio, a larger ranging range, higher precision, stronger anti-interference capability, and a higher response speed.

[0100] Referring again to Figs, la, 2a-2b, and 3a, the laser ranging system further comprises a rotatable beam deflection device 21, which is configured to deflect the transmitted detection beam 5 from the beam separation device 3 towards the detection region 4, and to deflect the reflected detection beam 6 from the detection region towards the beam separation device 3. The beam deflection device 21 may have a plurality of reflective surfaces, for example a polygon mirror. The beam deflection device 21 may be a single-sided reflector, a galvanometer mirror, a microelectromechanical rotating mirror, and the like. In this way, a larger detection region can be covered.

[0101] Although not shown, the beam separation device 3 in the laser ranging system of the present disclosure may also have a filter coating, the filter coating allowing only the reflected detection beam 6 to pass through to reach the receiving device 2. In this way, stray light from the external environment can be prevented from entering the receiving device along with the reflected detection beam to cause noise. Therefore, this arrangement can further improve the signal-to-noise ratio, and reduce the system cost, making the system more compact.

[0102] It should be understood that the first asymmetric geometric shape may be symmetrical, or may also be asymmetrical, relative to a central axis passing through the geometric centre of the first asymmetric geometric shape and perpendicular to the reference axis.

[0103] The beam separation device has a second geometric shape along a first direction transverse to the optical axis of the transmitting device. For example, as shown in Figs, la-ld, 2a-2b, and 3a-3d, the beam separation device 3 has, along a first direction transverse to the optical axis 20 of the transmitting device 1, a second geometric shape that is rectangular.

[0104] According to some embodiments, the second geometric shape is adapted to the light trajectory of the reflected detection beam within the field-of-view range of the receiving device, for example, the minimum size of the second geometric shape is determined according to the light trajectory of the reflected detection beamwithin the field-of-view range of the lens of the receiving device.

[0105] It should be understood that Figs, la-ld, 2a-2b, and 3a-3d are merely schematic, and the second geometric shape may be circular or another shape adapted to the light trajectory of the reflected detection beam within the field-of-view range of the receiving device.

[0106] It should be understood that the geometric centre of the first asymmetric geometric shape and the geometric centre of the second geometric shape may coincide, or may not coincide. Fig. 4 shows a schematic diagram of a vehicle 400 according to one embodiment of the present disclosure. The vehicle of the present disclosure (for example, the vehicle 400 in Fig. 4) may comprise the laser ranging system as described herein, and according to some embodiments, the vehicle 400 comprises, for example, the laser ranging system shown in at least one of Fig. la, Figs. 2a- 2b, Fig. 3a, Fig. 5a, Fig. 6a, and Fig. 7a. The distribution of the laser ranging system on the vehicle may be designed according to functional requirements. For example, the laser ranging system herein may be provided on the front bumper or roof of the vehicle (as shown by 401 in Fig. 4), for adaptive cruise and collision warning. For example, the laser ranging system herein may be provided on both sides of the vehicle body. For example, the laser ranging system herein may be provided on the rear bumper of the vehicle, for assisted parking. The vehicle of the present disclosure may be an electrified vehicle, for example a battery electric vehicle (BEV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), or a range extended electrified vehicle (REEV). The vehicle of the present disclosure may also be a hydrogen energy vehicle. The vehicle of the present disclosure may further be a motor vehicle. It should be understood that the vehicle of the present disclosure also has the advantages described herein with respect to the laser ranging system.

[0107] Various embodiments of the laser ranging system for a vehicle according to the embodiments of the present disclosure are described in detail below by referring to Figs. 5a to 7d. Figs. 5a, 6a, and 7a respectively show three different forms of laser ranging systems. According to some embodiments, the laser ranging system as described in the present disclosure may use the time-of-flight method(ToF) to carry out distance measurement. However, the present disclosure is not limited to what is shown in the drawings and disclosed herein, and appropriate modifications or improvements made on the basis of the systems shown in the drawings and disclosed herein shall also be included within the scope of protection of the present disclosure.

[0108] As shown in Figs. 5a, 6a, and 7a, the laser ranging system according to the present disclosure may comprise a transmitting device 1, a receiving device 2, and a beam separation device 3.

[0109] The transmitting device 1 is configured to generate a transmitted detection beam 5 that is to be transmitted to the detection region 4. As shown in Fig. 1, the transmitting device 1 may comprise a light source 15 and a transmitting optical system 17. The light beam emitted from the light source 15 is collimated and shaped via the transmitting optical system 17, for example, reducing the beam divergence angle and producing a light beam of a special shape, thereby forming a suitable transmitted detection beam 5. For example, the light source 15 may be a laser diode (LD) or a fibre laser. The transmitting optical system 17 may also be referred to as a laser shaping optical system, which may comprise at least one lens, as shown in Fig. 5a, or may comprise at least one reflector, or a combination of a lens and a reflector. It should be noted that the light rays in the transmitting device 1 shown in Fig. 5a are merely schematic and do not represent the actual situation. The transmitted detection beam 5 generated by the transmitting device 1 may have a relatively small cross-sectional area, the cross-sectional area being the cross-sectional area on a plane perpendicular to the optical axis 20 of the transmitting device 1.

[0110] The detection region 4 is an object or living creature in the surrounding environment of the vehicle, and the transmitted detection beam irradiated thereon undergoes diffuse reflection, and a portion of the reflected transmitted detection beam returns to the laser ranging system along the path of the transmitted detection beam 5 and is referred to herein as the reflected detection beam 6, or may also be abbreviated as the reflected beam.

[0111] The receiving device 2 is configured to receive the reflected detection beam6 reflected by the detection region 4. As shown in Fig. 5a, the receiving device 2 may comprise a detector 16 and a receiving optical system 18. For example, the detector 16 may be a photodiode, an avalanche photodiode, a single-photon avalanche diode, a photomultiplier tube, or the like. In some cases, it may also be a complementary metal oxide semiconductor (CMOS) image sensor, a charge-coupled device (CCD) image sensor, or the like. The receiving optical system 18 may be an optical lens having a large aperture and a high transmission rate, and may comprise at least one lens, as shown in Fig. 5a, or may comprise at least one reflector, or a combination of a lens and a reflector. It should be noted that the light rays in the receiving device 2 shown in Fig. 5a are merely schematic and do not represent the actual situation. It can be seen from Fig. 5a that, compared with the transmitted detection beam 5, the reflected detection beam 6 has a larger cross-sectional area, which is usually determined by the beam separation device 3. This ensures that a sufficient amount of light can be detected.

[0112] The beam separation device 3 is configured to transmit the transmitted detection beam 5 towards the detection region 4, and to transmit the reflected detection beam 6 to the receiving device 2. As used herein, “transmit” includes transmission and reflection, as the case may be. As shown in Figs. 5b to 5d, Figs.

[0113] 6b to 6d, and Figs. 7b to 7d, the beam separation device 3 has a filter element, the filter element allowing only light beams having wavelengths within a wavelength band corresponding to the reflected detection beam 6 to pass through to reach the receiving device 2. The filter element allows light beams corresponding to the wavelength band of the reflected detection beam 6 to pass through to reach the receiving device 2, while blocking light beams having wavelengths outside the wavelength band corresponding to the reflected detection beam 6.

[0114] According to some embodiments, the “wavelength band corresponding to the reflected detection beam 6” refers to a specific wavelength range matching the wavelength of the reflected detection beam 6, for example, a specific wavelength range containing the wavelength of the reflected detection beam 6 but not containing the wavelength of stray light.

[0115] By using the above filter element, for example by effectively filtering outambient light, stray light, and interference light of other wavelengths that may exist, the signal-to-noise ratio of the receiving device 2 receiving the reflected detection beam 6 can be improved, so as to further enhance the anti-interference capability of the system, and improve the precision and reliability of ranging. In addition, by integrating the filter element into the beam separation device 3, additional elements can be reduced, thereby simplifying the system structure and reducing system complexity and manufacturing cost.

[0116] The “passing” of a light beam described herein includes the situation where, after the light beam interacts with an object, the light beam can continue to propagate, that is, it includes both transmission of the light beam through the object and reflection of the light beam on the object, wherein, whether by transmission or reflection, the light beam energy continues to propagate in some manner, rather than being completely absorbed or scattered by the object. Therefore, the light beam “passing” through an object may be understood as meaning that, after the light beam interacts with the object, at least part of the light beam energy is still emitted from the object. For example, stray light having wavelengths outside the wavelength band corresponding to the reflected detection beam 6 is filtered out by the filter element and will not reach the receiving device 2 via the beam separation device 3.

[0117] Through the above design, there is no need to provide a separate filter element (for example, a transmission-type filter) in the receiving optical path, reducing the system size and lowering the cost, while at the same time avoiding the influence of stray light on the signal-to-noise ratio of the system, improving the signal-to-noise ratio of the entire system, increasing the ranging range and precision, enhancing anti-interference capability, improving the system response speed, and reducing dependence on high-sensitivity detectors. For example, the system of the present disclosure can provide sufficient optical signals for a single-photon avalanche diode as the detector, such that it can be applied to long-distance measurement.

[0118] According to some embodiments, the filter element has a bandwidth smaller than the full width at half maximum (FWHM) of the transmitted detection beamor the reflected detection beam, for example, the filter element has a bandwidth smaller than 35 nm. According to some embodiments, “full width at half maximum” refers to the full width of the laser (for example, the transmitted detection beam or the reflected detection beam) pulse time intensity curve at half of the width.

[0119] Referring again to Figs. 5a, 6a, and 7a, the beam separation device 3 comprises a single beam splitter, and the filter element described above is a filter coating provided on the beam splitter 3.

[0120] According to some embodiments, the filter element may be a filter coating formed by coating. According to some embodiments, the beam separation device comprises at least one coating, wherein the filter element is, for example, a filter coating formed by coating.

[0121] According to some embodiments, the filter element is located on the side of the beam separation device facing the receiving device and / or on the side facing the transmitting device 1 , wherein the filter element comprises the portion of the side of the beam separation device on the side facing the receiving device and / or on the side facing the transmitting device 1 for transmitting the reflected detection beam to the receiving device. According to some embodiments, during the process of forming the filter coating as the filter element by coating, the non-filter-element portion of the beam separation device on the side facing the receiving device and / or on the side facing the transmitting device 1 is masked, so as to form the filter element in the desired region of the beam separation device on the side facing the receiving device and / or on the side facing the transmitting device 1.

[0122] According to some embodiments, the side of the beam separation device facing the receiving device further includes a portion for transmitting the transmitted detection beam to the detection region, wherein the portion for transmitting the transmitted detection beam to the detection region may be an antireflection element, and the anti-reflection element may be, for example, an antireflection coating formed by coating, so as to avoid possible reflection of the transmitted detection beam and reduce optical loss, which can further improve the signal-to-noise ratio of the system.

[0123] Figs. 5b to 5d show enlarged schematic cross-sectional views of a beamseparation device of a laser ranging system according to one embodiment of the present disclosure (for example, the beam separation device 3 of the laser ranging system in Fig. 5a).

[0124] As shown in Fig. 5b, the beam separation device 3, that is, the beam splitter, has a substrate 30, a through hole 9 through which the transmitted detection beam 5 is able to pass is provided on the substrate, and a filter coating 31 is provided on the side of the substrate 30 facing the receiving device 2, and covers the region of the substrate 30 other than the through hole 9. The transmitted detection beam 5 can pass through the beam splitter without obstruction, and the reflected detection beam 6 can be reflected to the receiving device 2 via the filter coating 31. The filter coating 31 may be a reflective band-pass filter coating, and the wavelength range of the light beams that it is capable of reflecting is identical with, or at least partially overlaps with, the wavelength range of the reflected detection beam 6. The transmitted detection beam 5 from the transmitting device 1 is transmitted to the detection region 4 through the through hole 9, and the reflected detection beam 6 reflected by the detection region 4 enters the receiving device 2 by reflection from the filter coating 31. In this process, only the reflected detection beam 6 can reach the receiving device 2, and stray light having wavelengths different from that of the reflected detection beam 6 will not be reflected to the receiving device 2, thereby avoiding the noise brought by such stray light and improving the signal-to-noise ratio of the system.

[0125] In Fig. 5b, an anti-reflection coating 50 may also be coated on the side of the substrate 30 facing the transmitting device 1, so as to avoid possible reflection of the transmitted detection beam. A cross-sectional view of the beam separation device 3 is shown in Fig. 5b, wherein a straight line with an arrow extending horizontally to the right indicates the direction Z parallel to the optical axis 20 of the transmitting device 1 (or coincident therewith), which may also be referred to as the propagation direction of the transmitted detection beam. The beam separation device 3 is inclined relative to the optical axis 20 at a non-zero angle a about an inclination axis transverse to (for example, perpendicular to) the optical axis 20 of the transmitting device 1. The inclination axis is, for example,perpendicular to the plane of Fig. 5a. For example, the non-zero angle a may be 45°. In this case, the optical axis 20 of the transmitting device 1 and the optical axis of the receiving device 2 are perpendicular to each other. Of course, other angles are also possible, it being only necessary to correspondingly modify the optical axis of the receiving device 2 so as to match that angle.

[0126] According to some examples, as shown in Fig. 5c, the filter coating 31 may be provided on the side of the substrate 30 facing the transmitting device 1, and cover the region of the substrate 30 other than the through hole 9. According to some embodiments, in this case, the substrate 30 is transparent to the reflected detection beam 6, and the filter coating 31 is a transmission-type band-pass filter coating. In addition, a reflective surface is provided on the side of the filter coating 31 facing the transmitting device 1 , which reflects the reflected detection beam 6 to the receiving device 2. In some examples, as shown in Fig. 5c, an anti-reflection coating 50 may also be provided on the side of the beam splitter, for example the substrate 30, facing the receiving device 2, and cover the region of the substrate 30 other than the through hole 9. The anti-reflection coating 50 may be used to reduce reflection of the reflected detection beam 6 at that location. In some examples, an anti-reflection coating 50 may additionally be provided on the side of the filter coating 31 in Fig. 5c facing the transmitting device 1.

[0127] In some examples, the anti-reflection coating 50 shown in Fig. 5c may be replaced with another filter coating, and the other filter coating also covers the region of the substrate 30 other than the through hole 9. In other words, filter coatings are provided on both the side of the substrate 30 facing the receiving device 2 and the side facing the transmitting device 1. It is also possible to provide another filter coating between the anti-reflection coating 50 shown in Fig. 5c and the side of the substrate 30 facing the receiving device 2.

[0128] In some examples, as shown in Fig. 5d, a light-absorbing coating 40 is provided on the side of the beam splitter, for example the substrate 30, facing the transmitting device 1, and covers the region of the substrate 30 other than the through hole 9, thereby making it possible to prevent light beams that are not the transmitted detection beam 5, or transmitted detection beams 5 not within therequired field of view or numerical aperture, from propagating from the through hole 9 to the detection region 4. This can improve the signal-to-noise ratio and detection precision. In the case shown in Fig. 5c, a light-absorbing coating 40 may also be provided on the side of the filter coating 31 facing the transmitting device I . The light-absorbing coating 40 may be part of a blackening treatment layer of the substrate.

[0129] As shown in Fig. 6a, in another example, the receiving device 2 may be arranged in the lower side, opposite to that shown in Fig. 5a. In addition, in Fig.

[0130] 6a, the beam separation device 3 may also be a single beam splitter.

[0131] Figs. 6b to 6d show enlarged schematic cross-sectional views of a beam separation device of a laser ranging system according to one embodiment of the present disclosure (for example, the beam separation device 3 of the laser ranging system in Fig. 6a).

[0132] Referring to Fig. 6b, the beam splitter has a substrate 30, the substrate has a portion 11 through which the transmitted detection beam 5 is able to be transmitted, and a filter coating 35 is provided on the side of the substrate 30 facing the receiving device 2 and covers the region of the substrate 30 other than the portion I I . For example, the substrate 30 may as a whole be made of a material transparent to the transmitted detection beam 5. The filter coating 35 may be a reflective bandpass filter coating, and the wavelength range of the light beams that it is capable of reflecting is identical with, or at least partially overlaps with, the wavelength range of the reflected detection beam 6. The transmitted detection beam 5 from the transmitting device 1 is transmitted to the detection region 4 by being transmitted through the portion 11 of the substrate 30, and the reflected detection beam 6 reflected by the detection region 4 enters the receiving device 2 by reflection from the filter coating 35. In this process, only the reflected detection beam 6 can reach the receiving device 2, and stray light having wavelengths different from that of the reflected detection beam 6 will not be reflected to the receiving device 2, thereby avoiding the noise brought by such stray light and improving the signal-to-noise ratio of the system.

[0133] In addition, an anti-reflection coating 33 may be coated on the side of thesubstrate 30 facing the transmitting device 1, and cover the entire region of the substrate 30. Further, the region on the side of the substrate 30 facing the receiving device 2 that is not covered by the filter coating 35 may be coated with an antireflection coating 34, which is aligned with the portion 11 of the above substrate through which the transmitted detection beam 5 is able to be transmitted. That is, the anti-reflection coating 34 is provided on the surface of said portion facing the transmitting device 2. The provision of the anti-reflection layers at these two places makes it possible to avoid possible reflection of the transmitted detection beam and reduce optical loss, which can further improve the signal-to-noise ratio of the system.

[0134] Similarly to Fig. 5b, the beam separation device 3 shown in Fig. 6b is inclined relative to the optical axis 20 at, for example, a non-zero angle of 45° about an inclination axis transverse to (for example, perpendicular to) the optical axis 20 of the transmitting device 1. The inclination axis is, for example, perpendicular to the plane of Fig. 6a. In this case, the optical axis 20 of the transmitting device 1 and the optical axis of the receiving device 2 are perpendicular to each other. Of course, other angles are also possible, it being only necessary to correspondingly modify the optical axis of the receiving device 2 so as to match that angle.

[0135] In some examples, as shown in Fig. 6c, the filter coating 35 may be provided on the side of the substrate 30 facing the transmitting device 1, and covers the region of the substrate 30 other than the portion 11. In this case, the filter coating 35 is a transmission-type band-pass filter coating. In addition, a reflective surface is provided on the side of the filter coating 35 facing the transmitting device 1, which reflects the reflected detection beam 6 to the receiving device 2.

[0136] In some examples, as shown in Fig. 6c, an anti-reflection coating 50 may also be provided on the side of the beam splitter, for example the substrate 30, facing the receiving device 2, and cover the region of the substrate 30 other than the portion 11 (not shown in the figure). The anti-reflection coating 50 may be used to reduce reflection of the reflected detection beam 6 at that location. In some other examples, an anti-reflection coating 50 may additionally be provided on the side of the filter coating 35 in Fig. 6c facing the transmitting device 1.In some examples, the anti-reflection coating 33 shown in Fig. 6b may also be partially or wholly replaced with a light-absorbing coating 40, which covers the region of the substrate 30 other than the portion 11, thereby making it possible to prevent light beams that are not the transmitted detection beam 5, or transmitted detection beams 5 not within the required field of view or numerical aperture, from propagating from the portion 11 to the detection region 4. This can improve the signal-to-noise ratio and detection precision.

[0137] In some examples, as shown in Fig. 6d, another filter coating 35 is additionally provided on the side of the substrate 30 facing the receiving device 2, and the other filter coating also covers the region of the substrate 30 other than the portion 11 (although not shown in the figure). In other words, filter coatings are provided on both the side of the substrate 30 facing the receiving device 2 and the side facing the transmitting device 1.

[0138] As shown in Fig. 7a, in another example, the positions of the transmitting device 1 and the receiving device 2 are interchanged, that is, the transmitted detection beam 5 emitted by the transmitting device 1 is reflected by the beam separation device 3 towards the detection region 4, and the reflected detection beam 6 reflected by the detection region is transmitted through the beam separation device 3 and then received by the receiving device 2.

[0139] Figs. 7b to 7d show enlarged schematic cross-sectional views of a beam separation device of a laser ranging system according to one embodiment of the present disclosure (for example, the beam separation device 3 of the laser ranging system in Fig. 7a).

[0140] As shown in Fig. 7b, the beam separation device 3 has a substrate 30 through which the reflected detection beam 6 is able to be transmitted and a reflective coating 13 provided on one side of the substrate 30 and capable of reflecting the transmitted detection beam 5, and the filter coating 36 is provided on the other side of the substrate 30 away from the reflective coating 13. In other words, the reflective coating 13 is provided on the side of the substrate 30 facing the transmitting device 1, and the filter coating 36 is provided on the other side of the substrate 30 facing the receiving device 2. The filter coating 36 may be atransmission-type band-pass filter coating, and the wavelength range of the light beams that it is capable of transmitting is identical with, or at least partially overlaps with, the wavelength range of the reflected detection beam 6. The transmitted detection beam 5 from the transmitting device 1 is transmitted to the detection region 4 by reflection from the reflective coating 13, and the reflected detection beam 6 reflected by the detection region 4 is successively transmitted through the substrate 30 and the filter coating 36 and enters the receiving device 2. In this process, only the reflected detection beam 6 can reach the receiving device 2, and stray light having wavelengths different from that of the reflected detection beam 6 will not be transmitted through the filter coating 36, thereby avoiding the noise brought by such stray light and improving the signal-to-noise ratio of the system.

[0141] Similarly to Fig. 5b, the beam separation device 3 in Fig. 7b is arranged relative to the optical axis 20 at, for example, a non-zero angle of 45° about an inclination axis transverse to (for example, perpendicular to) the optical axis 20 of the transmitting device 1. The inclination axis is, for example, perpendicular to the plane of Fig. 7a. In this case, the optical axis 20 of the transmitting device 1 and the optical axis of the receiving device 2 are perpendicular to each other. Of course, other angles are also possible, it being only necessary to correspondingly modify the optical axis of the receiving device 2 so as to match that angle.

[0142] In addition, on the region of the substrate 30 on the side facing the transmitting device 1 that is not covered by the reflective coating 13, an antireflection coating 50 for the reflected detection beam may also be coated, as shown in Fig. 7c, and the anti-reflection coating makes it possible to avoid possible reflection of the reflected detection beam and reduce optical loss, which can further improve the signal-to-noise ratio of the system.

[0143] In some other examples, as shown in Fig. 7d, another filter coating 36 may also be coated on the region of the substrate 30 on the side facing the transmitting device 1 that is not covered by the reflective coating 13. In other words, in the embodiment shown in Fig. 7d, filter coatings are provided on both the side of the substrate 30 facing the receiving device 2 and the side facing the transmittingdevice 1.

[0144] In some other examples, in the example shown in Fig. 7d, the filter coating 36 on the side of the substrate 30 facing the receiving device 2 is replaced with an anti-reflection coating 50.

[0145] The filter element described above is in the form of a filter coating on a single beam splitter, but the present disclosure is not limited thereto. In other examples, the beam separation device may take the form of a cube beam splitter, and the filter element may be a coating applied thereon. In some other examples, the filter element may be a separate element, which is arranged adjacent to the beam splitter. It should be noted that the filter element of the present disclosure operates in a reflective or transmissive manner according to a specific design.

[0146] Referring again to Figs. 5a, 6a, and 7a, the laser ranging system further comprises a rotatable beam deflection device 21, which is configured to deflect the transmitted detection beam 5 from the beam separation device 3 towards the detection region 4, and to deflect the reflected detection beam 6 from the detection region towards the beam separation device 3. The beam deflection device 21 may have a plurality of reflective surfaces, for example a polygon mirror. The beam deflection device 21 may be a single-sided reflector, a galvanometer mirror, a microelectromechanical rotating mirror, and the like. In this way, a larger detection region can be covered.

[0147] According to some embodiments, the geometric shape of the portion of the beam separation device 3 for transmitting the transmitted detection beam 5 being adapted to the region on which the transmitted detection beam 5 irradiates on the beam separation device 3 means that the geometric shape of the portion highly matches the contour of the irradiation region formed by the transmitted detection beam 5 on the beam separation device 3, so that the geometric shape of the portion of the beam separation device 3 for transmitting the transmitted detection beam 5 is made as close as possible to the irradiation region formed by the transmitted detection beam 5 on the beam separation device 3. According to some embodiments, the geometric shape of the portion of the beam separation device 3 for transmitting the transmitted detection beam 5 may be determined based on theirradiation region formed by the transmitted detection beam 5 on the beam separation device 3.

[0148] The size of the portion for transmitting the transmitted detection beam 5 in the direction parallel to the inclination axis increases as the distance from the transmitting device 1 increases along the direction of light propagation parallel to the optical axis 20 (that is, along the direction Z). For example, the through hole 9 in Fig. 5b may have a trapezoid shape or pear shape that is narrow at the top and wide at the bottom. For example, the portion 11 of the substrate in Fig. 6b that transmits the transmitted detection beam 5 may have a trapezoid shape or pear shape that is wide at the top and narrow at the bottom, and correspondingly, the anti-reflection coating 34 on the surface of said portion facing the transmitting device 2 has a corresponding trapezoid shape or pear shape. For example, the reflective coating 13 in Fig. 7b may have a trapezoid shape or pear shape that is narrow at the top and wide at the bottom. It should be understood that other asymmetrical shapes that are wide at the top and narrow at the bottom or narrow at the top and wide at the bottom are also possible. The said shape adapted to the projection region enables more reflected detection beams 6 to be transmitted (for example, transmitted or reflected) into the receiving device 2, so that the system has a higher signal-to-noise ratio, a larger ranging range, higher precision, stronger anti-interference capability, and a higher response speed.

[0149] It should be understood that other shapes are also possible, for example, the size of the portion for transmitting the transmitted detection beam 5 in the direction perpendicular to the inclination axis remains almost unchanged with the distance from the transmitting device 1 along the direction of light propagation parallel to the optical axis 20 (that is, along the direction Z).

[0150] It may also be said that the portion of the beam separation device 3 for transmitting the transmitted detection beam 5 has a first asymmetrical geometric shape that is asymmetrical relative to the reference axis. The reference axis is parallel to the inclination axis described above and passes through the geometric centre of the first asymmetrical geometric shape.

[0151] The beam separation device has a second geometric shape along a directiontransverse to the optical axis of the transmitting device. For example, the beam separation device 3 has, along a direction transverse to the optical axis 20 of the transmitting device 1 , a second geometric shape that is rectangular.

[0152] According to some embodiments, the second geometric shape is adapted to the light trajectory of the reflected detection beam within the field-of-view range of the receiving device, for example, the minimum size of the second geometric shape is determined according to the light trajectory of the reflected detection beam within the field-of-view range of the lens of the receiving device.

[0153] It should be understood that what is shown in the figures is merely schematic, and the second geometric shape may be circular or another shape adapted to the light trajectory of the reflected detection beam within the field-of-view range of the receiving device.

[0154] The various technical features disclosed above are not limited to the combinations with other features that have been disclosed, and those skilled in the art may also make other combinations among the various technical features according to the purpose of the invention, provided that the purpose of the present disclosure is achieved.

Claims

2024PF02934Claims1. A laser ranging system, comprising:a transmitting device (1), configured to generate a transmitted detection beam (5) that is to be transmitted to a detection region (4);a receiving device (2), configured to receive a reflected detection beam (6) reflected by the detection region; anda beam separation device (3), configured to transmit the transmitted detection beam towards the detection region, and to transmit the reflected detection beam to the receiving device,wherein the beam separation device (3) has a first portion (7) for transmitting the transmitted detection beam (5) and a second portion (8) for transmitting the reflected detection beam (6),wherein the first portion has, along a first direction transverse to the optical axis (20) of the transmitting device (1), a first asymmetric geometric shape that is asymmetric relative to a reference axis,wherein the beam separation device (3) is inclined, about a first inclination axis transverse to the optical axis (20) of the transmitting device (1), relative to the optical axis (20) at a non-zero angle, and the reference axis is parallel to the first inclination axis and passes through a geometric centre of the first asymmetric geometric shape.

2. The laser ranging system according to claim 1, wherein the first asymmetric geometric shape of the first portion (7) is adapted to a region on the beam separation device (3) irradiated by the transmitted detection beam (5).

3. The laser ranging system according to claim 1 or 2, wherein the size of the first portion (7) in a direction parallel to the first inclination axis increases as the distance from the transmitting device (1) increases along a direction parallel to the optical axis (20).

4. The laser ranging system according to claim 1 or 2, wherein the first asymmetric geometric shape comprises a trapezoid.

5. The laser ranging system according to claim 1 or 2, wherein the first 1100296.7asymmetric geometric shape comprises a pear shape.

6. The laser ranging system according to claim 1 or 2, wherein the beam separation device (3) has a through hole (9), as the first portion (7), through which the transmitted detection beam (5) is able to pass, and a reflective coating, as the second portion (8), capable of reflecting the reflected detection beam (6).

7. The laser ranging system according to claim 1 or 2, wherein the beam separation device (3) has a transparent portion (11), as the first portion (7), through which the transmitted detection beam (5) is able to be transmitted, and a reflective coating, as the second portion (8), capable of reflecting the reflected detection beam (6).

8. The laser ranging system according to claim 1 or 2, wherein the beam separation device (3) has a reflective coating, as the first portion (7), capable of reflecting the transmitted detection beam (5), and a transparent portion, as the second portion (8), through which the reflected detection beam (6) is able to be transmitted.

9. The laser ranging system according to claim 1 or 2, wherein the beam separation device (3) has a filter coating, the filter coating allowing only the reflected detection beam (6) to pass through to reach the receiving device (2).

10. The laser ranging system according to claim 1 or 2, wherein the laser ranging system further comprises a rotatable beam deflection device (21), which is configured to deflect the transmitted detection beam (5) from the beam separation device (3) towards the detection region (4), and to deflect the reflected detection beam (6) from the detection region towards the beam separation device (3).

11. The laser ranging system according to claim 1 or 2, wherein the beam separation device (3) has, along a first direction transverse to the optical axis (20) of the transmitting device (1), a second geometric shape, the second geometric shape being adapted to a light trajectory of the reflected detection beam (6) within a field-of-view range of the receiving device (2).

12. A laser ranging system, comprising:a transmitting device (1), configured to generate a transmitted detection beam (5) that is to be transmitted to a detection region (4);a receiving device (2), configured to receive a reflected detection beam (6) reflected by the detection region; anda beam separation device (3), configured to transmit the transmitted detection beam (5) towards the detection region (4), and to transmit the reflected detection beam (6) to the receiving device (2),wherein the beam separation device (3) has a filter element, the filter element allowing only light beams having wavelengths within a wavelength band corresponding to the reflected detection beam (6) to pass through to reach the receiving device (2).

13. The laser ranging system according to claim 12, wherein the filter element has a bandwidth smaller than the full width at half maximum of the transmitted detection beam or the reflected detection beam.

14. The laser ranging system according to claim 12, wherein the beam separation device (3) comprises a single beam splitter, and the filter element is a filter coating provided on the beam splitter.

15. The laser ranging system according to claim 14, wherein the beam splitter has a substrate (30), the substrate is provided with a through hole (9) through which the transmitted detection beam (5) is able to pass, and the filter coating (31) is provided on a side of the substrate (30) facing the receiving device (2) and / or on a side facing the transmitting device (1), and covers a region of the substrate (30) other than the through hole (9).

16. The laser ranging system according to claim 14, wherein the beam splitter has a substrate (30), the substrate has at least a portion (11) through which the transmitted detection beam (5) is able to be transmitted, and the filter coating (35) is provided on a side of the substrate (30) facing the receiving device (2) and / or on a side facing the transmitting device (1), and covers a region of the substrate (30) other than the portion (11).

17. The laser ranging system according to claim 14, wherein the beam splitter has a substrate (30) through which the reflected detection beam (6) is able to be transmitted and a reflective coating (13), which is provided on a side of the substrate facing the transmitting device (1) and is capable of reflecting thetransmitted detection beam (5), and the filter coating (36) is provided on a side of the substrate (30) facing the receiving device (2), and / or is provided on a side facing the transmitting device (1) and covers a region of the substrate (30) other than the reflective coating (13).

18. The laser ranging system according to any one of claims 15 to 17, wherein anti-reflection coatings (33, 34, 50) are provided on a side of the beam splitter facing the transmitting device (1) and / or on a side facing the receiving device (2).

19. The laser ranging system according to claim 15 or 17, wherein a lightabsorbing coating (40) is provided on a side of the beam splitter facing the transmitting device (1).

20. The laser ranging system according to claim 12, wherein a portion of the beam separation device (3) for transmitting the transmitted detection beam has a geometric shape adapted to a projection region of the transmitted detection beam (5) on the beam separation device (3).

21. The laser ranging system according to claim 12, wherein the laser ranging system further comprises a rotatable beam deflection device (21), which is configured to deflect the transmitted detection beam (5) from the beam separation device (3) towards the detection region (4), and to deflect the reflected detection beam (6) from the detection region towards the beam separation device (3).

22. A vehicle, comprising the laser ranging system according to any one of claims 1 to 21.

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