Laser radar system and laser measurement method

Abstract

The invention discloses a laser radar system and a laser measurement method, which can be applied to an automatic driving vehicle and can maintain a large field angle while reducing the overall size of the system. The laser radar system may include: a light emitting module including at least one laser light source for generating emitted light; the first scanning part is provided with a first surface, and the first scanning part rotates or swings in the first direction, so that the first surface scans the emitted light from the laser light source in the first direction; the first optical transmission module is used for collimating and / or converging the emitted light reflected by the first scanning part; the second scanning component rotates or swings in a second direction so as to scan the emitted light from the first optical transmission module in the second direction, emit the light to a target scene and receive reflected light reflected by the target scene; and the light receiving module comprises at least one light receiving unit and is used for receiving the reflected light.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of radar technology, and in particular to a laser radar system and a laser measurement method. Background Art

[0002] In the field of autonomous driving, the LiDAR system is one of the most important sensors in autonomous vehicles. Today, the development direction of LiDAR is miniaturization and low cost. At the same time, the performance requirements of LiDAR have also been improved. While being able to achieve long-distance ranging, it is also required to have a large field of view.

[0003] However, the currently used automotive laser radars generally have the following shortcomings: the detection distance of existing automotive laser radars is usually 200m, the horizontal field of view is usually 120°, and the vertical field of view is usually only 25°. Increasing the vertical field of view often increases the size of the laser radar. The laser radar with the Flash solution has a short detection distance due to the large area of ​​the emitted light source and low energy density.

[0004] In addition, semiconductor lasers have the advantages of small size, low cost, and good durability, and are widely used in various fields. However, the divergence angle of semiconductor lasers is very large. In order to make the laser beam emitted by the semiconductor laser propagate far enough and maintain a high energy density, the emitted laser needs to be collimated. However, the cross-sectional area of ​​the collimated laser beam becomes larger, which is not conducive to the optimization of the optical transceiver system. Therefore, it is necessary to balance the collimation and beam area of ​​the laser beam. Summary of the invention

[0005] The technical solution provided by this application at least partially solves the above technical problems.

[0006] According to one aspect of the present application, a laser radar system is provided, which may include: a light emitting module, including at least one laser light source, for generating emitted light; a first scanning component, having a first surface, the first scanning component rotates or swings along a first direction so that the first surface scans the emitted light from the laser light source in a first direction; a first optical transmission module, collimating and / or converging the emitted light reflected by the first scanning component; a second scanning component, the second scanning component rotates or swings along a second direction to scan the emitted light from the first optical transmission module in a second direction and emit it to a target scene, and receive reflected light reflected back from the target scene; and a light receiving module, including at least one light receiving unit, for receiving reflected light.

[0007] In some embodiments, the laser radar system further includes a second optical transmission module, which is used to collimate and / or converge the emission light generated by the laser light source and then transmit it to the first scanning component.

[0008] In some embodiments, the second optical transmission module includes a lens or a reflector, a curved surface of the lens or the reflector has a first curvature in a third direction and a second curvature in a fourth direction, the first curvature and the second curvature are different, and the third direction and the fourth direction are different.

[0009] In some embodiments, the curved surface of the lens or reflector has rotational symmetry.

[0010] In some embodiments, the second optical transmission module includes a first cylindrical mirror and a second cylindrical mirror, the first cylindrical mirror is used to collimate or converge the emitted light generated by the laser light source in a first direction, so that the spot size of the emitted light in the first direction is less than or equal to the size of the first surface of the first scanning component in the first direction; the second cylindrical mirror is used to collimate or converge the emitted light in the second direction, so that the spot size of the emitted light in the second direction is less than or equal to the size of the first surface of the first scanning component in the second direction.

[0011] In some embodiments, the first optical transmission module includes a third cylindrical mirror, which is used to collimate and / or converge the emission light reflected by the first scanning component in the second direction, so that the divergence angle of the collimated and / or converged emission light in the second direction is less than a preset divergence angle.

[0012] In some embodiments, the third cylindrical mirror is an arc-shaped cylindrical mirror, which makes the emitted light converge in the second direction and makes the divergence angles of the emitted light emitted from different angles in the first direction tend to be consistent.

[0013] In some embodiments, the first optical transmission module further includes a prism, and the prism is used to deflect the emission light reflected by the first scanning component so that the light output height of the deflected emission light is within a preset height range.

[0014] In some embodiments, the ratio of the size of the first scanning component in the first direction to the size of the second scanning component in the second direction is smaller than the first size ratio; and / or, the ratio of the size of the first scanning component in the direction perpendicular to the first direction and the size of the second scanning component in the direction perpendicular to the second direction is smaller than the second size ratio; wherein the first size ratio and the second size ratio are in the range of 0 to 1.

[0015] In some embodiments, the first scanning component includes at least one micro-vibration mirror; the micro-vibration mirror includes at least one of a single-axis micro-vibration mirror and a multi-axis micro-vibration mirror; the dimensions of the reflective surface of the micro-vibration mirror in the first direction and the second direction are both in the range of 0.1mm-10mm.

[0016] In some embodiments, the second scanning component includes at least one reflective surface, and the same reflective surface of the second scanning component is used as the exit surface of the emitted light and the receiving surface of the reflected light, or different reflective surfaces of the second scanning component are used as the exit surface of the emitted light and the receiving surface of the reflected light respectively.

[0017] In some embodiments, the second scanning component includes a one-dimensional rotating mirror or a one-dimensional swinging mirror, and the reflecting surface includes a rectangular reflecting surface, and the length and width of the rectangular reflecting surface are both in the range of 10 mm-100 mm.

[0018] In some embodiments, the first optical transmission module further includes an optical path separation device for transmitting the emitted light received from the first scanning component to the second scanning component and reflecting the reflected light received from the second scanning component to the optical receiving module.

[0019] In some embodiments, the optical path separation device includes a reflector with a transmission hole, a mirror with a part of its area coated with a high-transmission film and a part of its area coated with a high-reflection film, or a polarization splitter.

[0020] In some embodiments, the laser radar system further includes an optical receiving component disposed on a receiving optical path of the optical receiving module, and the optical receiving component is used to collect and converge reflected light and transmit the reflected light to the optical receiving module.

[0021] According to another aspect of the present application, a laser measurement method is also provided, which includes: generating emission light through at least one laser light source; receiving the emission light through a first scanning component and scanning the emission in a first direction; collimating and / or converging the emission light reflected by the first scanning component through a first optical transmission module; scanning the emission light from the first optical transmission module in a second direction through a second scanning component, and emitting it to a target scene; and receiving reflected light reflected back from the target scene through the second scanning component, and transmitting the reflected light to a light receiving module directly or via the second scanning component; and converting the received reflected light into an electrical signal through the light receiving module, and sending the electrical signal to a data processing module for processing and calculation, so as to obtain information about the target object in the target scene.

[0022] The laser radar system and laser measurement method provided in the embodiments of the present application can have a large field of view while reducing the overall size of the system, while ensuring that the energy density of the emitted laser is high and the distance is far, while maintaining good optical performance.

[0023] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present application, nor is it intended to limit the scope of the present application. Other features of the present application will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Other features, purposes and advantages of the present application will become more apparent by reading the detailed description of the non-limiting embodiments made with reference to the following drawings. The drawings are used to better understand the present solution and do not constitute a limitation of the present application. In the drawings:

[0025] Figure 1 is a schematic block diagram of the composition of a laser radar system according to the first embodiment of the present application;

[0026] Figure 2 is a schematic block diagram of the composition of a laser radar system according to a second embodiment of the present application;

[0027] Figure 3 is a schematic block diagram of the composition of a laser radar system according to a third embodiment of the present application;

[0028] Figure 4 is a schematic structural diagram of a laser radar system according to Embodiment 1 of the present application;

[0029] Figure 5A is a schematic diagram of deflecting emitted light by a prism according to an embodiment of the present application;

[0030] Figure 5B is a schematic structural diagram of an arc-shaped cylindrical mirror according to an embodiment of the present application;

[0031] Figure 6 is a schematic structural diagram of a laser radar system according to Embodiment 2 of the present application;

[0032] Figure 7 is a schematic diagram of optical path separation of emitted light and reflected light in a coaxial optical path according to an embodiment of the present application;

[0033] Figure 8 It is a schematic flow chart of the laser measurement method according to the implementation mode of the present application.

[0034] Reference numerals:

[0035] 100, first laser radar system; 110, optical transmission module; 101, laser light source; 102, first cylindrical mirror; 103, second cylindrical mirror; 120, first scanning component; 130, first optical transmission module; 301, third cylindrical mirror; 302, prism; 140, second scanning component; 401a, first reflection surface; 401b, second reflection surface; 150, optical receiving module; 170, optical receiving component; 200, second laser radar system; 210, Light emitting module; 211, first laser light source; 212, second laser light source; 220, first scanning component; 230, first optical transmission module; 240, second scanning component; 250, light receiving module; 260, second optical transmission module; 270, optical receiving component; 310, light emitting module; 320, first scanning component; 330, first optical transmission module; 340, second scanning component; 350, light receiving module; 360, second optical transmission module. DETAILED DESCRIPTION

[0036] In order to better understand the present application, a more detailed description will be made of various aspects of the present application with reference to the accompanying drawings. It should be understood that these detailed descriptions are only descriptions of exemplary embodiments of the present application, and are not intended to limit the scope of the present application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0037] It should also be understood that expressions such as "include", "including", "have", "contain" and / or "comprising" are open rather than closed expressions in this specification, which indicate the presence of the stated features, elements and / or components, but do not exclude the presence of one or more other features, elements, components and / or combinations thereof. In addition, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features rather than just the individual elements in the list. In addition, when describing embodiments of the present application, "may" is used to mean "one or more embodiments of the present application". And, the term "exemplary" is intended to refer to an example or illustration.

[0038] In the description of the embodiments of the present application, the terms "first", "second", and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. In addition, the order in which the steps are described does not necessarily refer to the order in which the steps are performed, unless it can be determined from the context that the steps are performed sequentially.

[0039] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. Any one or more embodiments or elements thereof, or the arrangement or combination of some or all embodiments or elements thereof described herein are merely exemplary and are not intended to limit the scope of the present application.

[0040] The following is a description of the exemplary embodiments of the present application in conjunction with the accompanying drawings. Various details of the embodiments of the present application are included to facilitate understanding, and they should be considered as merely exemplary. Therefore, it should be appreciated by those of ordinary skill in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present application.

[0041] Reference Figures 1 to 3 According to the first aspect of the present application, a laser radar system (hereinafter referred to as the system) is provided, which can be used, for example, in assisted driving systems of autonomous vehicles or aircraft and other systems that need to sense the surrounding environment. It can ensure high energy density and long distance of the emitted laser, and can also meet the requirements of large vertical field of view while reducing the overall size of the system.

[0042] The current laser radar system usually mainly includes a light source system, a scanning device, a receiving system and a data processing module. The light source system is used to emit a detection laser beam; the scanning device is used to scan the laser beam emitted by the light source system, and emit the laser beam to different positions of the target object in the target scene at different times; the receiving system is used to receive the laser beam reflected from different positions of the target object in the target scene at different times, and convert it into an electrical signal, and then transmit it to the data processing module; the data processing module processes and calculates the electrical signal to obtain information such as the distance, spatial angle, and speed of the target object. The laser radar system generally also includes a control unit for controlling the timing and intensity of the laser beam emission, optical scanning, and optical reception. For the sake of clarity and conciseness, the description of some well-known functions and structures will be omitted in the following description.

[0043] Figure 1 A laser radar system according to a first embodiment of the present application is shown, and the laser radar system may include a light emitting module 110 , a first scanning component 120 , a first optical transmission module 130 , a second scanning component 140 and a light receiving module 150 .

[0044] The optical emission module 110 may include at least one laser light source for generating an initial laser beam (also referred to as emitted light); and a first scanning component 120 and a second scanning component 140. The first scanning component 120 may rotate or swing along a first direction to scan the emitted light in a first direction through its first surface or cause the emitted light to scan a target scene in a first direction. The first surface may be a reflective surface or an incident surface or an exit surface. The second scanning component 140 may rotate or swing along a second direction to scan the emitted light in a second direction or cause the emitted light to scan a target scene in a second direction and then emit to the target scene.

[0045] In an exemplary embodiment, a first optical transmission module 130 is further disposed on the optical path between the first scanning component 120 and the second scanning component 140 . The first optical transmission module 130 collimates and / or converges the emission light reflected by the first scanning component 120 and transmits the light to the second scanning component 140 .

[0046] In some exemplary embodiments, the first optical transmission module 130 further deflects the direction of the emitted light reflected by the first scanning component 120 .

[0047] In some exemplary embodiments, the laser radar system may further include a second optical transmission module (not shown in the figure), which is arranged in the optical path of the laser light source and is used to collimate and / or focus the emission light generated by the laser light source. The second optical transmission module may be arranged inside the light emitting module 110, or between the light emitting module 110 and the first scanning component 120. The specific content of the second optical transmission module will be described in detail below in conjunction with specific embodiments.

[0048] Exemplarily, the second scanning component 140 is also used to receive reflected light of at least a portion of the emitted light reflected back from the target scene, and then transmit it to the light receiving module 150. The light receiving module 150 receives the reflected light and can convert it into an electrical signal through a photodetector, etc., and then transmit it to a data processing module (not shown) for subsequent processing and calculation to obtain information of the target object in the target scene, for example, at least one of the following information of the target object in the target scene: distance, spatial angle, profile, and moving speed.

[0049] Figure 2 A laser radar system according to a second embodiment of the present application is shown, and the laser radar system may include a light emitting module 210, a first scanning component 220, a first optical transmission module 230, a second scanning component 240 and a light receiving module 250.

[0050] Referring to the description in the first embodiment, the emitted light generated by the light emitting module 210 sequentially passes through the first scanning component 220 to perform scanning in the first direction, the first optical transmission module 230 performs collimation and / or convergence, and the second scanning component 240 performs scanning in the second direction before emitting to the target scene. That is, the emission light path of the emitted light sequentially passes through the first scanning component 220, the first optical transmission module 230 and the second scanning component 240 to reach the target scene.

[0051] like Figure 2 As shown, the reflected light reflected from the target scene is reflected by the second scanning component 240, then passes through the first optical transmission module 230, and then is transmitted to the optical receiving module 250. Different from the aforementioned first embodiment, in this second embodiment, the outgoing optical path of the emitted light and the receiving optical path of the reflected light have a common optical path portion, which is called a "coaxial optical path". Relatively speaking, in the first embodiment, there is no common optical path portion between the outgoing optical path and the receiving optical path inside the laser radar system, which is called a "non-coaxial optical path". For the case of the "coaxial optical path", in this second embodiment, the first optical transmission module 230 can also reuse an optical path separation device (not shown), through which the emitted light received from the first scanning component 220 is transmitted to the second scanning component 240, and the reflected light received from the second scanning component 240 is transmitted to the optical receiving module 250.

[0052] Figure 3 A laser radar system according to a third embodiment of the present application is shown, and the laser radar system may include a light emitting module 310, a first scanning component 320, a first optical transmission module 330, a second scanning component 340, a light receiving module 350, and a second optical transmission module 360. For the sake of brevity, some descriptions similar to the previous embodiments will be omitted in the third embodiment.

[0053] like Figure 3 As shown, the laser radar system of the third embodiment is provided with a second optical transmission module 360 ​​between the light emitting module 310 and the first scanning component 320 for collimating and / or focusing the emission light generated by the laser light source and then transmitting it to the first scanning component 310 .

[0054] In the third embodiment, the outgoing optical path of the emitted light and the receiving optical path of the reflected light have a common optical path portion. In view of this situation, the first optical transmission module 330 multiplexes an optical path separation device (not shown) to achieve optical path separation of the emitted light and the reflected light. The specific content of the optical path separation device will be described in detail below in conjunction with specific embodiments.

[0055] According to the laser radar system of the exemplary embodiment of the present application, the ratio of the size of the first scanning component in the first direction to the size of the second scanning component in the second direction is smaller than the first size ratio; and / or, the ratio of the size of the first scanning component in the vertical direction of the first direction to the size of the second scanning component in the vertical direction of the second direction is smaller than the second size ratio. The first size ratio and the second size ratio can be in the range of 0 to 1, for example, 0.01, 0.1, 0.25, or 0.5, etc.

[0056] The features, principles and other aspects of the present application will be described in more detail below with reference to the accompanying drawings and in combination with specific embodiments.

[0057] Embodiment 1

[0058] Combination Figure 1 and Figure 4 As shown, the first laser radar system 100 provided in the first embodiment of the present application mainly includes a light transmitting module 110, a first scanning component 120, a first optical transmission module 130, a second scanning component 140, a light receiving module 150 and an optical receiving component 170, and also includes a second optical transmission module, which may include a first cylindrical mirror 102 and a second cylindrical mirror 103.

[0059] The first scanning component 120 may include a micro-vibration mirror, wherein the micro-vibration mirror may include at least one of a uniaxial micro-vibration mirror and a multi-axis micro-vibration mirror. For example, the micro-vibration mirror may be a one-dimensional MEMS (Micro Electro-Mechanical System) micro-vibration mirror or a Galvano vibration mirror, which has at least one reflective surface. The first scanning component 120 may rotate or swing along a first direction, for example, it may make a reciprocating or rotational motion in the first direction, and reflect the emitted light to different angles through its reflective surface to perform scanning in the first direction. The second scanning component 140 may include a one-dimensional rotating mirror or a one-dimensional swinging mirror, which has at least one reflective surface. The second scanning component 140 may rotate or swing along a second direction to scan the received emitted light in a second direction. The first direction and the second direction intersect with each other, and the intersection angle is not greater than 90°. As an exemplary embodiment, the first direction and the second direction may be perpendicular to each other, for example, the first direction may be a vertical direction, and the second direction may be a horizontal direction.

[0060] refer to Figure 4As shown, as an exemplary embodiment, the first scanning component 120 is a one-dimensional MEMS micro-vibration mirror. The second scanning component 140 is a one-dimensional rotating mirror, which can be a multi-prism structure, such as a triangular prism, a quadrangular prism, a pentagonal prism, a hexagonal prism, etc. The one-dimensional rotating mirror may include a plurality of reflecting surfaces, such as a first reflecting surface 401a and a second reflecting surface 401b, and the shape of the reflecting surface may be a rectangle. Exemplarily, the length and width of the rectangular reflecting surface are both in the range of 10 mm-100 mm.

[0061] Exemplarily, the light emitting module 110 generates emission light, which is scanned in a first direction through the reflective surface of the first scanning component 120, and multiple light beams are formed in the first direction, which is equivalent to forming multiple groups of laser light beams from the emission light generated by the laser light source 101 in the first direction, and then incident on the second scanning component 140 after passing through the first optical transmission module 130, and after being scanned in a second direction through the first reflective surface 401a of the second scanning component 140, it is emitted to the target scene. The reflected light reflected from the target scene is reflected by the second reflective surface 401b of the second scanning component 140, and then collected and converged by the optical receiving component 170 and incident on the light receiving module 150. Exemplarily, the optical receiving component 170 may include but is not limited to a plano-convex lens. The light receiving module 150 may include a plurality of light receiving units arranged linearly in one dimension or two dimensions, and the light receiving units may include but are not limited to photoelectric detectors such as avalanche diodes or single photon detectors (APD, SiPM, SPAD).

[0062] In an exemplary embodiment, the optical receiving module 150 may further include an aperture and a narrowband filter, wherein the aperture may be used to reduce the field of view of the receiving system, and the narrowband filter may be used to reduce the transmission of stray light.

[0063] In this embodiment, the outgoing optical path and the receiving optical path of the laser radar system 100 are non-coaxial optical paths, and the number of light receiving units in the light receiving module 150 is greater than or equal to the number of laser light sources 101 in the light transmitting module 110 .

[0064] In an exemplary embodiment, the laser radar system 100 further includes a data processing module and a control module. The light receiving unit converts the received reflected light into an electrical signal and outputs it to the data processing module; the data processing module processes and calculates the electrical signal to obtain at least one of the distance, spatial angle, profile and moving speed of the target object in the target scene. The control unit can be used to control the timing and intensity of emitting the laser beam, optical scanning, optical reception and other operations.

[0065] In an exemplary embodiment, the optical transmission module 110 includes at least one laser light source 101, which can be an EEL (Edge-Emitting Semiconductor Lasers) or a vertical cavity surface emitting semiconductor laser (VCSEL), or a solid laser, or a fiber laser. The laser light source 101 can be configured to emit one or more short pulses of a few nanoseconds. The laser light source 101 can also be configured to emit a continuous modulated or coded laser pulse light of tens of nanoseconds to a few microseconds.

[0066] As an example, the laser light source 101 is described below as an edge-emitting semiconductor laser EEL. Semiconductor lasers have the advantages of high photoelectric conversion efficiency and miniaturization. However, the divergence angles of semiconductor lasers in two directions parallel and perpendicular to the junction plane are asymmetric. Therefore, the laser beam generated by the semiconductor laser has different divergence angles in the fast axis direction and the slow axis direction, resulting in uneven light intensity distribution, a narrow and long elliptical spot in the far field, poor beam quality, and limited propagation distance.

[0067] In view of the above-mentioned defects of semiconductor lasers, the laser radar system 100 may further include a second optical transmission module. As an exemplary embodiment, the second optical transmission module may include a first cylindrical mirror 102 and a second cylindrical mirror 103. It should be noted that the second optical transmission module may be arranged inside the optical transmission module 110 or on the optical path between the optical transmission module 110 and the first scanning component 120.

[0068] The first cylindrical mirror 102 is used to collimate the emitted light generated by the laser light source 101 in a first direction (for example, the EEL fast axis direction), so that the spot size of the collimated emitted light in the first direction matches the size of the reflective surface of the first scanning component 120 in the first direction. The meaning of the spot size can refer to the full width at half maximum (FWHM) diameter, that is, the diameter at the 1 / 2 position of the peak value is used as the beam diameter; it can also refer to the 86% surrounding power diameter, that is, the diameter accounting for 86% of the total power is used as the beam diameter, etc., and this application does not impose any restrictions on this. By using the first cylindrical mirror 102 to collimate the emitted light in the fast axis direction, on the one hand, the output spot size of the emitted light can be matched with the size of the MEMS micro-vibration mirror, thereby improving the light extraction efficiency and avoiding energy loss; on the other hand, the divergence angle in the fast axis direction can also be reduced.

[0069] The second cylindrical mirror 103 is used to converge the emitted light in the second direction (for example, the EEL slow axis direction), so that the spot size of the converged emitted light in the second direction is less than or equal to the size of the reflective surface of the first scanning component 120 in the second direction. Exemplarily, the size of the reflective surface of the one-dimensional MEMS micro-mirror of the present application in the first direction and the second direction are both within the range of 0.1mm-10mm. By using the second cylindrical mirror 103 to converge the slow axis, the propagation distance of the emitted light can be made longer, and the optical performance of the slow axis can be improved.

[0070] As described above, after the emitted light passes through the first cylindrical mirror 102 and the second cylindrical mirror 103 and reaches the first scanning component 120, the divergence angle in the slow axis direction will be greater than that in the fast axis direction. In order to further balance the differences in the emitted light at different angles, as an exemplary embodiment, the first optical transmission module 130 may include a third cylindrical mirror 301. The third cylindrical mirror 301 is used to collimate and / or converge the emitted light reflected by the first scanning component 120 in the second direction (i.e., the EEL slow axis direction), so that the collimated and / or converged emitted light has a higher collimation in the second direction, maintains a better energy density, and also makes the divergence angle of the emitted light in the second direction less than the preset divergence angle, and the preset divergence angle can range from 0.01° to 10°, so that the size and divergence angle of the emitted light incident on the second scanning component 140 in each direction are more uniform, the beam quality is better, and it has a higher energy density.

[0071] In addition, in some other exemplary embodiments, in addition to the above-mentioned method including two cylindrical mirrors, the second optical transmission module may also use other lenses or reflectors such as spherical mirrors. A curved surface of the lens or reflector may have a first curvature in the third direction and a second curvature in the fourth direction, the first curvature and the second curvature are different, and the third direction and the fourth direction are different. For example, by setting the first curvature and the second curvature to corresponding curvatures, the collimation of the emitted light in the third direction and the convergence in the fourth direction can be achieved. As an exemplary embodiment, the above-mentioned curved surface of the lens or reflector may also have rotational symmetry to achieve consistency of light beams in different directions.

[0072] In an exemplary embodiment, in order to further realize a system miniaturization design, the first optical transmission module 130 may further include a prism 302. For example, the prism 302 may be a triangular prism. Figure 5A As shown, the emitted light reflected by the first scanning component 120 is relatively divergent, and the initial light emission height of the laser radar system is H1. The emitted light reflected by the first scanning component 120 can be deflected by the prism 302, so that the light emission height of the deflected emitted light is reduced, for example, it can be controlled within a preset height H2 range, and the preset height H2 is less than the initial light emission height H1.

[0073] like Figure 5B As shown, in an exemplary embodiment, the third cylindrical mirror 301 is an arc-shaped cylindrical mirror. As mentioned above, the light spot expanded in the second direction needs to be collimated, but because the scanning angle of a single-axis micro-vibration mirror such as a MEMS micro-vibration mirror is large, the third cylindrical mirror 301 used for collimation in the second direction needs to have different focal lengths at different scanning angles (light output angles). If the distance between the MEMS micro-vibration mirror and the third cylindrical mirror 301 is greater than the focal length, the collimation effect of the light beam is not good. The use of an arc-shaped cylindrical mirror can make the emitted light converge in the second direction, and the arc-shaped cylindrical mirror has no convergence or diffusion effect in the first direction, so that the divergence angles of the emitted light emitted from different angles in the first direction can be consistent. Exemplarily, the arc-shaped cylindrical mirror can be integrally formed.

[0074] In an exemplary embodiment, the third cylindrical lens 301 and the prism 302 may be integrally formed, that is, the third cylindrical lens 301 and the prism 302 are an integral lens.

[0075] The laser radar system in the related art usually adopts a beam expander, which can change the beam radius and divergence angle. However, if the direction of the beam expansion is consistent with the direction of the MEMS micro-vibration mirror scanning, the light output angle of the MEMS micro-vibration mirror scanning will be lowered. According to the laser radar system provided in the embodiment of the present application, the first scanning component receives the emitted light for scanning in the first direction, and reflects the emitted light to different angles to obtain a wider scanning angle or range (equivalent to beam expansion in the second direction); then the emitted light is collimated and / or converged in the second direction through the first optical transmission module, so that the beam expansion of the emitted light and the scanning of the MEMS micro-vibration mirror are in different directions. In this way, it not only achieves the effect of beam expansion, but also improves the collimation of the emitted light without affecting the scanning result of the MEMS micro-vibration mirror.

[0076] Embodiment 2

[0077] Combination Figure 2 and Figure 6 As shown, the second laser radar system 200 provided in the second embodiment of the present application mainly includes a light transmitting module 210, a first scanning component 220, a first optical transmission module 230, a second scanning component 240, a light receiving module 250, an optical receiving component 270 and a second optical transmission module 260. In this second embodiment, for the sake of brevity, some descriptions similar to those in the first embodiment are omitted.

[0078] Combination Figure 6, the light emitting module 210 may include a plurality of laser light sources 211 and 212, for example, may be EEL. The light emitting module 210 may also include a second optical transmission module 260. The first scanning component 220 may be a micro-vibration mirror, wherein the micro-vibration mirror may include at least one of a single-axis micro-vibration mirror and a multi-axis micro-vibration mirror. The second scanning component 240 may be a one-dimensional rotating mirror. Exemplarily, the reflective surface of the one-dimensional rotating mirror may be square.

[0079] Exemplarily, the second optical transmission module 260 may include a spherical mirror, which may be configured to have a first curvature in the third direction and a second curvature in the fourth direction, respectively for collimating the emitted light in the third direction and converging the emitted light in the fourth direction.

[0080] In some embodiments, the second optical transmission module 260 may further include a collimating lens. Figure 6 As shown, the two emission light beams generated by the two laser light sources 211 and 212 can be emitted along different emission light paths after passing through the collimating lens, and the different emission light paths basically intersect at the same position of the first scanning component 220.

[0081] In some other embodiments, the second optical transmission module 260 may further include a polarization beam combiner, such as a PBC (Polarization Beam Combiner), through which the two emission light beams generated by the two laser light sources 211 and 212 may be emitted along the same emission light path.

[0082] Combination Figure 6 and Figure 7 As shown, different from the aforementioned embodiment 1, in this embodiment, the emission surface of the emitted light and the receiving surface of the reflected light reflected from the target scene can be located on the same reflection surface of the second scanning component 240. After the emitted light is emitted from the reflection surface of the second scanning component 240 to the target scene, the reflected light reflected from the target scene is received and reflected by the same reflection surface of the second scanning component 240 to reach the first optical transmission module 230. Therefore, the emission light path and the receiving light path of the laser radar system 200 have a common light path portion, and the emission light path and the receiving light path are coaxial light paths.

[0083] For the coaxial optical path method, for example, when the same reflective surface of the second scanning component 240 is used as the exit surface of the emitted light and the receiving surface of the reflected light, the first optical transmission module 230 also includes an optical path separation device, which is used to transmit the emitted light received from the first scanning component 220 to the second scanning component 240; and transmit the reflected light received from the second scanning component 240 to the receiving optical path of the optical receiving module 250.

[0084] In some embodiments, the optical path separation device can be a reflector with a transmission hole. For example, the collimated and / or converged output light (the light beam is relatively concentrated) can be transmitted from the transmission hole of the reflector to the second scanning component 240, and the received reflected light (the light beam is relatively divergent) can be reflected through the reflector to the optical receiving component 270 disposed on the receiving light path of the optical receiving module 250, and then transmitted to the optical receiving module 250 after being collected and converged by the optical receiving component 270.

[0085] In some other embodiments, the optical path separation device can also be an optical element such as a mirror with a high-transmittance film coated on part of its area and a high-reflection film coated on part of its area, or it can also be a polarization splitter device, which can transmit light in a certain polarization direction and reflect light with a polarization perpendicular to this direction.

[0086] As an exemplary embodiment, the optical receiving module 250 may include at least one receiving device array configured to correspond to a narrow and long receiving field of view. For example, an avalanche diode array or a single photon detector array. The bias voltage of the avalanche diode array or the single photon detector array varies with time, so that the gain of the photodetector can be controlled. For example, for a close object, the received signal is strong, and the signal detection can be completed using a low gain, which can reduce the noise generated by the stray light of the system.

[0087] In addition, in some embodiments, the laser radar system may further include at least two light receiving modules, including at least one located in a coaxial optical path and at least one located in a non-coaxial optical path, and may simultaneously receive reflected light from the coaxial optical path and the non-coaxial optical path. Furthermore, the relative orientation or angle between the reflective surface of the second scanning component and the first optical transmission module and the light receiving module may be set to meet the requirements of different optical paths, such as a more compact optical path, an increased reflection angle, etc.

[0088] According to the laser radar system provided in the above-mentioned embodiment of the present application, the cost can be reduced and the volume can be reduced by adopting an array arrangement of semiconductor lasers and light receiving modules. The uniformity and accuracy of the emitted light at different angles can be improved through the first optical transmission module and the second optical transmission module, and a higher energy density and a longer propagation distance can be ensured. Moreover, a scanning range with a large field of view angle can be achieved while ensuring a small volume of the system, for example, a vertical field of view angle can be achieved that is greater than half of the horizontal field of view angle.

[0089] Embodiment 3

[0090] like Figure 8 As shown, the present application also provides a laser measurement method 800 of the laser radar system based on the aforementioned embodiment, and the laser measurement method 800 includes:

[0091] S10, generating emission light by at least one laser light source;

[0092] S20, receiving the emitted light through a first scanning component, and scanning the emitted light in a first direction;

[0093] S30, collimating and / or converging the emission light reflected by the first scanning component through a first optical transmission module;

[0094] S40, scanning the received emission light in a second direction by a second scanning component, and emitting the received emission light to a target scene;

[0095] S50, receiving reflected light reflected from the target scene through the second scanning component, and transmitting the reflected light to the light receiving module directly or through the second scanning component;

[0096] S60: Convert the received reflected light into an electrical signal through the light receiving module, and send the electrical signal to the data processing module for processing and calculation to obtain information of the target object in the target scene.

[0097] According to some exemplary embodiments, step S10 further includes collimating and / or converging the emission light generated by the laser light source through a second optical transmission module and transmitting the collimated and / or converged light to the first scanning component.

[0098] According to some exemplary embodiments, in step S60 , the received reflected light may be converted into an electrical signal by a light receiving unit in the light receiving module.

[0099] According to some exemplary embodiments, in step S60, the electrical signal may be processed and calculated by a data processing module to obtain at least one of the following information of the target object in the target scene: distance, spatial angle, outline, and moving speed.

[0100] The above specific implementations do not constitute a limitation on the protection scope of this application. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of this application should be included in the protection scope of this application.

Claims

1. A laser radar system, characterized in that: include: The light emitting module comprises at least one laser light source for generating emitted light; A first scanning component having a first surface, wherein the first scanning component rotates or swings along a first direction so that the first surface scans the emitted light from the laser light source in a first direction; a first optical transmission module, for collimating and / or converging the emission light reflected by the first scanning component; a second scanning component, the second scanning component rotates or swings along a second direction to scan the emitted light from the first optical transmission module in a second direction and emit it to a target scene, and receive reflected light reflected back from the target scene; as well as The light receiving module includes at least one light receiving unit, which is used to receive the reflected light.

2. The laser radar system according to claim 1, wherein: The laser radar system also includes a second optical transmission module, The second optical transmission module is used for collimating and / or converging the emission light generated by the laser light source and transmitting the collimated light to the first scanning component.

3. The laser radar system according to claim 2, wherein: The second optical transmission module includes a lens or a reflector, a curved surface of the lens or the reflector has a first curvature in a third direction and a second curvature in a fourth direction, the first curvature is different from the second curvature, and the third direction is different from the fourth direction.

4. The laser radar system according to claim 3, wherein: The curved surface of the lens or reflector has rotational symmetry.

5. The laser radar system according to claim 2, wherein: The second optical transmission module includes a first cylindrical mirror and a second cylindrical mirror. The first cylindrical mirror is used to collimate or converge the emitted light generated by the laser light source in the first direction, so that the spot size of the emitted light in the first direction is smaller than or equal to the size of the first surface of the first scanning component in the first direction; The second cylindrical mirror is used to collimate or converge the emitted light in the second direction so that the spot size of the emitted light in the second direction is smaller than or equal to the size of the first surface of the first scanning component in the second direction.

6. The laser radar system according to any one of claims 1 to 5, wherein: The first optical transmission module includes a third cylindrical mirror, which is used to collimate and / or converge the emission light reflected by the first scanning component in the second direction, so that the divergence angle of the collimated and / or converged emission light in the second direction is smaller than a preset divergence angle.

7. The laser radar system according to claim 6, wherein: The third cylindrical mirror is an arc-shaped cylindrical mirror, which makes the emitted light converge in the second direction and makes the divergence angles of the emitted light emitted from different angles in the first direction tend to be consistent.

8. The laser radar system according to claim 6, wherein: The first optical transmission module further includes a prism, The prism is used to deflect the emitted light reflected by the first scanning component so that the light output height of the deflected emitted light is within a preset height range.

9. The laser radar system according to claim 8, wherein: The third cylindrical mirror and the prism are an integrated mirror.

10. The laser radar system according to any one of claims 1 to 5, wherein: The ratio of the size of the first scanning component in the first direction to the size of the second scanning component in the second direction is smaller than the first size ratio; and / or the ratio of the size of the first scanning component in a direction perpendicular to the first direction to the size of the second scanning component in a direction perpendicular to the second direction is smaller than the second size ratio; The first size ratio and the second size ratio are in the range of 0 to 1.

11. The laser radar system according to any one of claims 1 to 5, wherein: The second scanning component includes at least one reflecting surface, and the same reflecting surface of the second scanning component is used as the exit surface of the emitted light and the receiving surface of the reflected light, or different reflecting surfaces of the second scanning component are used as the exit surface of the emitted light and the receiving surface of the reflected light respectively.

12. The laser radar system according to claim 11, wherein: The first scanning component includes at least one micro-vibration mirror, which includes at least one of a single-axis micro-vibration mirror and a multi-axis micro-vibration mirror, and the dimensions of the first surface of the micro-vibration mirror in the first direction and the second direction are both in the range of 0.1mm-10mm; the second scanning component includes a one-dimensional rotating mirror or a one-dimensional swinging mirror, and the reflecting surface includes a rectangular reflecting surface, and the length and width dimensions of the rectangular reflecting surface are both in the range of 10mm-100mm.

13. The laser radar system according to claim 11, wherein: The first optical transmission module also includes an optical path separation device, The optical path separation device is used to transmit the emitted light received from the first scanning component to the second scanning component, and transmit the reflected light received from the second scanning component to the light receiving module.

14. The laser radar system according to claim 13, wherein: The optical path separation device includes a reflector with a transmission hole, a mirror with a part of its area coated with a high transmission film and a part of its area coated with a high reflection film, or a polarization splitter.

15. The laser radar system according to any one of claims 1 to 5, wherein: The laser radar system also includes an optical receiving component arranged on the receiving light path of the optical receiving module, and the optical receiving component is used to collect and converge the reflected light and transmit it to the optical receiving module.

16. The laser radar system according to any one of claims 1 to 5, wherein: The first direction and the second direction intersect, and an intersection angle is no greater than 90°.

17. The laser radar system according to any one of claims 1 to 5, wherein: The laser light source includes an edge emitting semiconductor laser, a vertical cavity surface emitting semiconductor laser, a solid laser or a fiber laser.

18. The laser radar system according to any one of claims 1 to 5 or 17, wherein: The optical transmission module includes two laser light sources and a polarization beam combining device. The two beams of emitted light generated by the two laser light sources pass through the polarization beam combining device and are emitted along the same optical path.

19. The laser radar system according to any one of claims 1 to 5 or 17, wherein: The light emitting module comprises two laser light sources and a collimating lens. The two emission light beams generated by the two laser light sources are emitted along different emission light paths after passing through the collimating lens, and the different emission light paths substantially intersect at the same position of the first scanning component.

20. The laser radar system according to any one of claims 1 to 5, wherein: The light receiving module includes a plurality of light receiving units, the light receiving units are arranged linearly in one dimension or two dimensions, and the number of the light receiving units is greater than or equal to the number of the laser light sources.

21. The system according to claim 20, wherein: The optical receiving module comprises an aperture and a narrow-band filter. The aperture is used to reduce the field of view of the receiving system, and the narrow-band filter is used to reduce the transmission of stray light.

22. The laser radar system according to any one of claims 1 to 5 or 20, wherein: The light receiving unit includes an avalanche diode or a single photon detector.

23. The laser radar system according to any one of claims 1 to 5, wherein: The laser radar system also includes a data processing module, The light receiving unit converts the received reflected light into an electrical signal and outputs the electrical signal to the data processing module; The data processing module is used to process and calculate the electrical signal to obtain at least one of the following information of the target object in the target scene: distance, spatial angle, outline and moving speed.

24. A laser measurement method based on the laser radar system according to any one of claims 1 to 23, characterized in that: include: generating emission light by means of the at least one laser light source; receiving the emitted light by the first scanning component and scanning the emitted light in the first direction; collimating and / or converging the emission light reflected by the first scanning component through the first optical transmission module; Scanning the emitted light from the first optical transmission module in the second direction by the second scanning component, and emitting the light to the target scene; as well as receiving reflected light reflected from the target scene through the second scanning component, and transmitting the reflected light to the light receiving module directly or through the second scanning component; as well as The received reflected light is converted into an electrical signal by the light receiving module, and the electrical signal is sent to the data processing module for processing and calculation to obtain the information of the target object in the target scene.

25. The laser measurement method according to claim 24, wherein: The method further comprises: collimating and / or converging the emission light generated by the laser light source through a second optical transmission module, and then transmitting the collimated and / or converged light to the first scanning component.

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