Device for controlling emergent light steering and vertical direction of laser radar optical chip

Abstract

The utility model relates to the technical field of laser radar auxiliary materials, and solves the problems that in the prior art, a laser radar chip is vertically placed, so that the thickness of the whole laser radar is increased, the heat dissipation performance is reduced, and the size of the laser radar is increased due to limited internal space layout. The utility model relates to a laser radar optical chip, and discloses a device for emergent light steering and vertical control of the laser radar optical chip, which comprises a transmitting-receiving optical lens for collimating emitted laser, and one end of the transmitting-receiving optical lens is provided with a first plane mirror which is obliquely arranged. By adopting the device, the compactness of a laser radar structure can be improved, the thickness of the whole laser radar can be reduced, a driving plate of an optical chip can be completely attached to the inner surface of a laser radar shell, and heat dissipation of the optical chip is better facilitated.

Description

Technical Field

[0001] This application relates to the technical field of lidar auxiliary materials, and particularly to a device for light output steering and vertical control of a lidar optical chip. Background Art

[0002] A lidar is a device that can actively emit laser signals to obtain information such as the distance, speed, and position of a target object. Its principle is generally that the device first emits a signal light, and after the signal light is reflected by the target object, it is received by the device. By processing the emitted light and received light signals and comparing information such as the time and phase between the two signals, the distance, speed, position, etc. of the target object can be obtained.

[0003] Lidar can be classified into time-of-flight lidar, frequency-modulated continuous-wave lidar (Frequency Modulated Continuous Wave, FMCW), etc. according to its measurement principle. Among them, due to its unique ranging principle, FMCW lidar can effectively reduce the interference of ambient light on the lidar performance and improve the lidar ranging performance by means of balanced detection of the emitted light and received light at the receiving end. At the same time, in addition to providing traditional target object position and distance information, FMCW lidar can also provide the speed information of the target object. Therefore, FMCW lidar is recognized as the mainstream technology for the next generation of lidar.

[0004] A typical system of FMCW lidar uses an optical chip to transmit and receive optical signals, that is, the optical signal is emitted through an optical channel in the optical chip, and after the optical signal is reflected by the target object, it is received by the device and then enters the optical chip along the optical channel. The emitted light and received light are subjected to balanced detection in the optical chip, so that the combination of the transmitting end and the receiving end of the lidar can be realized, and the integration degree of the radar whole machine structure is higher.

[0005] To obtain the information of the target object in the detection space, lidar generally also uses scanning components such as a rotating mirror and a galvanometer. Among them, the rotating mirror is responsible for the scanning of the light beam in the horizontal direction x, and the galvanometer is responsible for the scanning in the vertical direction y. At the same time, the horizontal field of view range of lidar (usually 120°) is generally much larger than the vertical field of view range (usually 25°).

[0006] As Figure 2 shown, the shape of the rotating mirror 10 is generally a cube or a polyhedron, which rotates around the z-axis in the xy plane. Its surface 11 and its opposite surface are not reflective surfaces, and surface 12, surface 13 and their opposite surfaces are reflective surfaces. During the continuous rotation of the rotating mirror 10, the light beam can be reflected by the reflective surface of the rotating mirror to realize the large field of view scanning of the light beam in the horizontal direction.

[0007] A galvanometer mirror generally has an irregularly shaped reflective plane such as a rectangle, a circle, or an ellipse. Its rotation axis lies in the xy plane and it swings back and forth step by step around the rotation axis. During the swinging process, after the light beam is reflected by the reflective surface of the galvanometer mirror, the light beam can be scanned in a small vertical field of view.

[0008] Figure 3 It is a schematic diagram of an optical chip structure for an FMCW lidar. Among them, 21 is the drive board of the optical chip, which has the functions of supplying power and dissipating heat to the optical chip. 22 is the optical chip, 23 is the light output through-hole, and 24 is the third output light beam of the emitted laser light signal. The number of 4 light output through-holes of the chip is only for illustrative purposes and does not represent the actual number of through-holes of the chip. In space, the laser signal is emitted along the y direction, the x direction is the horizontal direction in space, and the z direction is the vertical direction in space.

[0009] During the process of using the optical chip in combination with a rotating mirror and a galvanometer mirror, if the chip is placed horizontally, the output light beams of the four channels are also arranged horizontally. After being reflected by the rotating mirror, the scanning light beams of the 4 channels will overlap. To avoid this situation, the chip can only be placed vertically as shown in Figure 4 shown.

[0010] However, compared with the horizontal placement method, the vertical placement method has the following defects:

[0011] 1. The overall thickness of the machine increases. When the chip is placed vertically, its drive board also needs to be placed vertically accordingly. At this time, the overall thickness of the lidar increases. In application scenarios such as vehicles, the thickness of the lidar is very limited. If it is placed horizontally, it is beneficial to optimize the overall thickness of the machine;

[0012] 2. The heat dissipation performance deteriorates. When the chip is placed vertically, the back of its drive board is suspended, which is not conducive to heat dissipation. If it is placed horizontally, the drive board can be completely attached to the inner surface of the lidar housing, and this method helps to dissipate heat from the optical chip;

[0013] 3. Due to the relationship between the rotating mirror and the galvanometer mirror, the inside of the device often cannot be made very compact, resulting in limited device volume. Summary of the Invention

[0014] The purpose of this application is to overcome the problems in the prior art that when laser beams arranged vertically need to be emitted, the vertical placement of the lidar chip leads to an increase in the overall thickness of the lidar, a decrease in heat dissipation performance, and an increase in the volume of the lidar due to limited internal space layout. A device for light output steering and vertical control of a lidar optical chip is provided.

[0015] In a first aspect, a device for light output steering and vertical control of a lidar optical chip is provided, including a transceiver optical lens for collimating the emitted laser. One end of the transceiver optical lens is provided with a first planar mirror placed obliquely, and a second planar mirror that can swing freely is arranged above the first planar mirror.

[0016] In some possible implementation manners, the optical axis of the transceiver optical lens is parallel to the laser emitted by the lidar optical chip.

[0017] In some possible implementation manners, the included angle between the first planar mirror and the horizontal plane is 45°.

[0018] In some possible implementation manners, it further includes a housing. The first planar mirror and the transceiver optical lens are both fixed at the bottom of the housing. The second planar mirror is arranged inside the housing. An incident light channel is reserved on one side of the housing. One end of the transceiver optical lens away from the first planar mirror faces the incident light channel. An output light channel is reserved on one surface of the housing. The mirror surface of the second planar mirror faces the output light channel.

[0019] In some possible implementation manners, the second planar mirror is connected to a scanning motor that drives the second planar mirror to swing reciprocally. The scanning motor is fixed on one side of the housing.

[0020] In some possible implementation manners, the rotation axis of the scanning motor is parallel to the optical axis of the transceiver optical lens, and the extension line of the rotation axis of the scanning motor passes through the center point of the second planar mirror.

[0021] In some possible implementation manners, both the first planar mirror and the second planar mirror are rectangular, the transceiver optical lens is circular, the horizontal side b of the first planar mirror is greater than or equal to the diameter D of the transceiver optical lens, and the inclined side a of the first planar mirror is greater than or equal to times the diameter D of the transceiver optical lens.

[0022] In some possible implementation manners, the horizontal side d of the second planar mirror is greater than or equal to the diameter D of the transceiver optical lens, and the inclined side c of the second planar mirror satisfies the following condition:

[0023] c≥ D / sin(45°-θ / 4)

[0024] where D is the diameter of the transceiver optical lens, and θ is the vertical angle of the laser that needs to be controlled.

[0025] In some possible implementations, the light-emitting and receiving optical lens includes a first housing, and a first concave lens, a second concave lens, a first convex lens, a second convex lens, a third convex lens, and a fourth convex lens that are sequentially arranged in the first housing along the end far from the first planar mirror towards the end close to the first planar mirror.

[0026] In some possible implementations, the light-emitting and receiving optical lens includes a second housing, and a fifth convex lens, a third concave lens, and a sixth convex lens that are sequentially arranged in the second housing along the end far from the first planar mirror towards the end close to the first planar mirror.

[0027] The present application has the following beneficial effects: The present application can convert the multi-channel horizontally arranged light beams into vertically arranged light beams, so that the optical chip can be kept horizontally placed unchanged. Compared with the vertical placement of the optical chip, the compactness of the lidar structure can be improved, the overall thickness of the lidar can be reduced, and the driving board of the optical chip can be completely attached to the inner surface of the lidar housing, which is more conducive to the heat dissipation of the optical chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The schematic embodiments and descriptions thereof of the present application are used to explain the present application and do not constitute an improper limitation to the present application.

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0030] Figure 1 It is a schematic structural diagram of the device for light output turning and vertical control of the lidar optical chip in the embodiment of the present application;

[0031] Figure 2 It is a schematic structural diagram of the rotating mirror;

[0032] Figure 3 It is a schematic structural diagram of the horizontal placement of the optical chip structure;

[0033] Figure 4 It is a schematic structural diagram of the vertical placement of the optical chip structure;

[0034] Figure 5 It is a perspective view of the device for light output turning and vertical control of the lidar optical chip in the embodiment of the present application with a housing;

[0035] Figure 6Schematic diagram of the placement positions of the light-emitting and light-receiving optical lens, the first plane mirror, and the second plane mirror of the device for controlling the light output direction and vertical direction of the lidar optical chip according to an embodiment of the present application;

[0036] Figure 7 Schematic diagram of the vertical beam control of the device for controlling the light output direction and vertical direction of the lidar optical chip according to an embodiment of the present application;

[0037] Figure 8 Schematic diagram of the dimensions of the light-emitting and light-receiving optical lens, the first plane mirror, and the second plane mirror of the device for controlling the light output direction and vertical direction of the lidar optical chip according to an embodiment of the present application;

[0038] Figure 9 Schematic diagram of the need to control the vertical angle FOV of the laser in the device for controlling the light output direction and vertical direction of the lidar optical chip according to an embodiment of the present application;

[0039] Figure 10 Schematic diagram of the dimensions of the second inclined edge of the second plane mirror of the device for controlling the light output direction and vertical direction of the lidar optical chip according to an embodiment of the present application;

[0040] Figure 11 Schematic diagram of the structure of the housing in the device for controlling the light output direction and vertical direction of the lidar optical chip according to an embodiment of the present application;

[0041] Figure 12 Schematic diagram of the overall operation of the device for controlling the light output direction and vertical direction of the lidar optical chip, the optical chip structure, and the rotating mirror according to an embodiment of the present application;

[0042] Figure 13 Schematic diagram of the structure of the light-emitting and light-receiving optical lens in the device for controlling the light output direction and vertical direction of the lidar optical chip according to an embodiment of the present application Figure 1 ;

[0043] Figure 14 Schematic diagram of the structure of the light-emitting and light-receiving optical lens in the device for controlling the light output direction and vertical direction of the lidar optical chip according to an embodiment of the present application Figure 2 。

[0044] Reference numerals:

[0045] 10. Rotating mirror; 11. Surface 1; 12. Surface 2; 13. Surface 3; 20. Optical chip structure; 21. Driving board; 22. Optical chip; 23. Light output through-hole; 24. Third output beam; 30. Transmitting and receiving optical lens; 40. First plane mirror; 50. Second plane mirror; 51. Scanning motor; 60. Housing; 61. Light input channel; 62. Light output channel; 70. First outer shell; 71. First concave lens; 72. Second concave lens; 73. First convex lens; 74. Second convex lens; 75. Third convex lens; 76. Fourth convex lens; 80. Second outer shell; 81. Fifth convex lens; 82. Third concave lens; 83. Sixth convex lens; 90. First inclined edge; 91. First horizontal edge; 92. Second inclined edge; 93. Second horizontal edge; 94. Incident beam; 95. First output beam; 96. Second output beam; 97. Axis of rotation; 98. Dashed arrow. Detailed implementation mode

[0046] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model. Embodiment

[0047] A device for light output steering and vertical control of the optical chip 22 of a lidar involved in the embodiments of the present application, as Figure 1 shown, from left to right are the transmitting and receiving optical lens 30 and the first plane mirror 40 in sequence. Above the first plane mirror 40 is the second plane mirror 50. Among them, the optical axis of the transmitting and receiving optical lens 30 is parallel to the laser emitted by the optical chip 22 of the lidar.

[0048] As Figure 5 and Figure 6 shown, the optical axis of the transmitting and receiving optical lens 30 is along the x-axis direction; the first horizontal edge 91 of the first plane mirror 40 is along the y-direction, and the first inclined edge 90 of the first plane mirror 40 forms a 45° angle with both the positive x and z directions; the second horizontal edge 93 of the second plane mirror 50 is along the x-direction, and the second inclined edge 92 of the second plane mirror 50 forms a 45° angle with the reflection surface and the yz plane; Figure 6 The dashed arrow 98 in

[0049] As Figure 1 shown, it is a schematic diagram of the steering of the light output beam of the optical chip structure 20 within the structure for steering and vertical control. Figure 1The incident light beam 94 is the light-emitting beam of the two light-emitting through holes 23 of the optical chip structure 20. After the incident light beam 94 enters the optical transceiver lens 30 of this embodiment along the positive x-axis direction, the optical transceiver lens 30 first collimates the incident light beam 94. Then, the two light beams are parallelly incident on the first planar mirror 40, and then the direction of the light beam is turned and reflected along the z direction to the second planar mirror 50. After being reflected by the second planar mirror 50, it exits along the y-axis direction. It can be seen that at this time, the light-emitting beam changes from a horizontal distribution to a vertical distribution. Among them, at this time, the angle between the second planar mirror 50 and the horizontal plane is 45°.

[0050] As Figure 7 shown, it is a schematic diagram of the vertical control of the light beam. When the second planar mirror 50 rotates clockwise and counterclockwise alternately along the rotation axis 97, the exit angles of the two vertically emitted light beams will change with the movement of the mirror of the galvanometer as Figure 7 the first exit light beam 95 and the second exit light beam 96 in.

[0051] As Figure 8 shown, it is a schematic diagram of the dimensions of the optical transceiver lens 30, the first planar mirror 40, and the second planar mirror 50. Its minimum size is determined by the diameter D of the optical transceiver lens 30 and the vertical angle FOV to be controlled. The first planar mirror 40 and the second planar mirror 50 need to ensure that they can cover the lens projection. The minimum size of the first horizontal side 91 of the first planar mirror 40 is D, and the minimum size of the first inclined side 90 of the first planar mirror 40 is . The minimum size of the second horizontal side 93 of the second planar mirror 50 is D, and the minimum size of the second inclined side 92 of the second planar mirror 50 is c0: As Figure 9 shown, c is the long side of the second planar mirror. c is in the initial state of 45°. n1 is the normal line in the initial state of c. l is the incident light and L is vertically incident on the second planar mirror 50 upward. f is the exit light; the vertical angle FOV to be controlled = θ, that is, when the incident light is vertically upward, the maximum angle swept by the exit light during the reciprocating swing of the second planar mirror 50 is θ. When c rotates counterclockwise by θ / 4, it is in the c0 position. At this time, the exit light deflects upward by θ / 2 from the f position, that is, at the f0 position of the exit light; when c rotates clockwise by θ / 4, it is in the c1 position. At this time, the light deflects downward by θ / 2 from the f position, that is, at the f1 position of the exit light; since we are looking for the minimum length (i.e., the maximum value here) required for the c side to not leak light, we only need to find the length of the c side when it rotates counterclockwise by θ / 4 angle, that is, the length of c0. According to the fact that the exterior angle of a triangle is equal to the sum of the two non-adjacent interior angles, as Figure 10 shown, n1 is the normal line of the second planar mirror in the c position, and n2 is the normal line of the second planar mirror in the c0 position. It can be obtained that:

[0052] c0 = D / sin(45° - θ / 4)

[0053] Wherein, D is the diameter of the light-emitting and light-receiving optical lens 30, and θ is the vertical angle of the laser to be controlled.

[0054] As Figure 5 , Figure 11 and Figure 12 shown, it further includes a housing 60. The first planar mirror 40 and the light-emitting and light-receiving optical lens 30 are both fixed at the bottom of the housing 60. The second planar mirror 50 is disposed inside the housing 60. An incident light channel 61 is reserved on one side of the housing 60. One end of the light-emitting and light-receiving optical lens away from the first planar mirror 40 faces the incident light channel 61. An outgoing light channel 62 is reserved on one surface of the housing 60. The mirror surface of the second planar mirror 50 faces the outgoing light channel 62. As Figure 12 shown, the light beam emitted by the optical chip mechanism 20 passes through the incident light channel 61 and enters the light-emitting and light-receiving optical lens 30. After being collimated by the light-emitting and light-receiving optical lens 30, it is incident on the reflecting surface of the first planar mirror 40. Subsequently, the light beam is reflected to the reflecting surface of the second planar mirror 50 and exits the housing 60 through the outgoing light channel 62. The light beam exiting the housing 60 is arranged in the vertical direction and is incident on the reflecting surface of the rotating mirror 10. The rotating mirror 10 controls the angle in the horizontal direction. By controlling the angle of the second planar mirror 50, the vertical angle of the outgoing light beam can be adjusted. The second planar mirror 50 functions as a galvanometer mirror. Therefore, after adopting the device for outgoing light steering and vertical control in this embodiment, no additional galvanometer mirror is required.

[0055] As Figure 7 shown, in order to drive the second planar mirror 50 to swing reciprocally, the second planar mirror 50 is connected to a scanning motor 51 that drives the second planar mirror 50 to swing reciprocally. The scanning motor 51 is fixed on one side of the housing 60. Preferably, the rotation axis of the scanning motor 51 is parallel to the optical axis of the light-emitting and light-receiving optical lens 30, and the extension line of the rotation axis of the scanning motor 51 passes through the center point of the second planar mirror 50, which is beneficial to the rotational balance of the second planar mirror 50.

[0056] It should be noted that generally, the light-emitting and light-receiving optical lens 30 uses a compound lens, which is composed of a convex lens and a concave lens. The convex lens has the function of converging light, and the concave lens has the function of diverging light. Generally, the mirror surface of the light-emitting and light-receiving optical lens 30 is usually spherical. This kind of lens is called a spherical lens. The side surface of an aspherical lens changes continuously from the center of the lens to the periphery. Using an aspherical lens can effectively overcome "spherical aberration".

[0057] In a possible embodiment, as Figure 13As shown, the transmitting and receiving optical lens 30 includes a first housing 70, and a first concave lens 71, a second concave lens 72, a first convex lens 73, a second convex lens 74, a third convex lens 75, and a fourth convex lens 76 that are sequentially arranged in the first housing 70 from the end far from the first plane mirror 40 to the end close to the first plane mirror 40. It is mainly used to test a target object with a certain field of view at infinity. It can be seen that multiple light-emitting points are collimated and emitted by the lens. According to the object-image relationship, different light-emitting points can be irradiated to different fields of view. Therefore, these two types of lenses can be used for testing target objects with a certain field of view compared to the first lens.

[0058] In the transmitting and receiving optical lens 30 in the above embodiment, the number of lenses is relatively large, with 6 pieces, which undoubtedly increases the production cost and assembly difficulty of the transmitting and receiving optical lens 30. For example, Figure 14 As shown, in order to reduce the production cost and assembly difficulty of the transmitting and receiving optical lens 30, the number of lenses is reduced to three. Specifically, the transmitting and receiving optical lens 30 includes a second housing 80, and a fifth convex lens 81, a third concave lens 82, and a sixth convex lens 83 that are sequentially arranged in the second housing 80 from the end far from the first plane mirror 40 to the end close to the first plane mirror 40.

[0059] The above is only a preferred specific embodiment of the present application; however, the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed in the present application, according to the technical solution and its improved concept of the present application, makes equivalent substitutions or changes, and should be covered by the protection scope of the present application.

Claims

1. A device for light steering and vertical control of a laser radar optical chip, characterized in that: The invention comprises a transceiver optical lens for collimating the emitted laser, wherein one end of the transceiver optical lens is provided with a first plane reflector placed obliquely, and a second plane reflector which can swing freely is provided above the first plane reflector.

2. The device for light steering and vertical control of a laser radar optical chip according to claim 1, characterized in that: The optical axis of the transceiver optical lens is parallel to the laser emitted by the laser radar optical chip.

3. The device for light steering and vertical control of a laser radar optical chip according to claim 1, characterized in that: The included angle between the first plane reflector and the horizontal plane is 45°.

4. The device for light steering and vertical control of a laser radar optical chip according to any one of claims 1 to 3, characterized in that: It also includes a shell, the first plane reflector and the transceiver optical lens are fixed at the bottom of the shell, the second plane reflector is arranged in the shell, a light input channel is reserved on one side of the shell, the end of the transceiver optical lens away from the first plane reflector faces the light input channel, and a light output channel is reserved on one side of the shell.

5. The device for light steering and vertical control of a laser radar optical chip according to claim 4, characterized in that: The second plane reflecting mirror is connected to a scanning motor for driving the second plane reflecting mirror to swing back and forth, and the scanning motor is fixed on one side of the housing.

6. The device for light steering and vertical control of a laser radar optical chip according to claim 5, characterized in that: The rotating shaft of the scanning motor is parallel to the optical axis of the transmitting and receiving optical lens, and the extended line of the rotating shaft of the scanning motor passes through the center point of the second plane reflector.

7. The device for light steering and vertical control of a laser radar optical chip according to claim 1, characterized in that: The first plane reflector and the second plane reflector are both rectangular, the transceiver optical lens is circular, the horizontal side b of the first plane reflector is greater than or equal to the diameter D of the transceiver optical lens, and the inclined side a of the first plane reflector is greater than or equal to times the diameter D of the transmitting and receiving optical lenses.

8. The device for light steering and vertical control of a laser radar optical chip according to claim 7, characterized in that: The horizontal side d of the second plane reflector is greater than or equal to the diameter D of the transmitting and receiving optical lens, and the inclined side c of the second plane reflector satisfies the following conditions: c≥ D / sin(45°-θ / 4) Where D is the diameter of the transmitting and receiving optical lens, and θ is the vertical angle of the laser that needs to be controlled.

9. The device for light steering and vertical control of a laser radar optical chip according to claim 1, characterized in that: The transmitting and receiving optical lens comprises a first shell, and a first concave lens, a second concave lens, a first convex lens, a second convex lens, a third convex lens and a fourth convex lens which are arranged in sequence in the first shell along an end away from the first plane reflector to an end close to the first plane reflector.

10. The device for light steering and vertical control of a laser radar optical chip according to claim 1, characterized in that: The transmitting and receiving optical lens comprises a second housing, and a fifth convex lens, a third concave lens and a sixth convex lens which are arranged in the second housing in sequence from an end away from the first plane reflector to an end close to the first plane reflector.

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