WO2020248336A1

WO2020248336A1 - Multi-line laser radar

Info

Publication number: WO2020248336A1
Application number: PCT/CN2019/097123
Authority: WO
Inventors: 胡小波; 白芳
Original assignee: 深圳市镭神智能系统有限公司
Priority date: 2019-06-11
Filing date: 2019-07-22
Publication date: 2020-12-17
Also published as: CN110208773A

Abstract

Provided is a multi-line laser radar, comprising: a transmitting plate integrating a plurality of transmitters and used for transmitting multiple laser beams; a rotating prism comprising a top face and a bottom face which are parallel to each other as well as multiple reflecting faces, wherein the multiple reflecting faces as well as the top face and the bottom face define a hollow shaft, and an included angle of each reflecting face with the top face is different; and an electric motor arranged in the hollow shaft of the rotating prism and used for driving the rotating prism to rotate. The plurality of transmitters are distributed in a plane in a vertical direction, and the multiple laser beams rotate by virtue of the rotating prism, so that number extension of the laser beams in the vertical direction and visual field scanning in a horizontal direction can be realized.

Description

Multi-line Lidar

Technical field

This application relates to the field of laser radar technology, and in particular to a multi-line laser radar.

Background technique

At present, Lidar has become a hot spot for everyone, and they are widely used in the field of autonomous driving. In some special applications, the standards for various performance parameters of lidar are quite high, such as detection range, detection accuracy, detection density, volume, and service life. However, if the number of lines of the existing multi-line lidar needs to be increased, the number of light sources needs to be increased accordingly, which not only increases the cost, but also affects the volume, and the debugging work becomes cumbersome.

Summary of the invention

Based on this, it is necessary to provide a multi-line lidar to solve the problems of high cost, large size, and heavy debugging work of the existing multi-line lidar.

A multi-line lidar, including:

Launch board, integrated with multiple emitters, used to emit multiple laser beams;

The rotating prism includes a top surface and a bottom surface that are parallel to each other and a plurality of mirror surfaces, the plurality of mirror surfaces and the top surface and the bottom surface enclose a hollow shaft, and the angle between each mirror surface and the top surface is not the same;

A motor, arranged in the hollow shaft of the rotating prism, for driving the rotating prism to rotate;

Wherein, the multiple emitters are distributed in a plane in the vertical direction, and the multiple laser beams can be rotated by the rotating prism to achieve the expansion of the number of laser beams in the vertical direction and the horizontal field of view scanning.

In one of the embodiments, the rotating prism includes at least four mirror surfaces, and for any mirror surface, the included angle with the top surface is simultaneously greater than the included angle between two adjacent mirror surfaces and the top surface. , Or at the same time smaller than the angle between the two adjacent mirror surfaces and the top surface.

In one of the embodiments, the maximum value of the angle between the reflecting surface and the top surface is α ₁ , and the minimum value of the angle between the reflecting surface and the top surface is α ₂ , 0°< |α ₁ -α ₂ |≤3°.

In one of the embodiments, the rotating prism includes four reflecting mirror surfaces; in a clockwise or counterclockwise direction, the angles between each reflecting surface and the top surface are 90 degrees, 89.5 degrees, 89.25 degrees, and 89.75 degrees, respectively.

In one of the embodiments, a photoelectric code disc is further included, the photoelectric code disc is arranged on the rotating prism and used to detect and output at least one of the angle information of the rotating prism and the speed information of the motor .

In one of the embodiments, it further includes a receiving board integrated with multiple receivers, the transmitting board and the receiving board are arranged on the same side of the rotating prism, and the multiple receivers and the multiple The transmitters have a one-to-one correspondence.

In one of the embodiments, the multi-line lidar includes two symmetrically arranged transmitting plates and two symmetrically arranged receiving plates, and each transmitting plate corresponds to a receiving plate on the same side of the rotating prism.

In one of the embodiments, it further includes an emission lens, an emission mirror, an emission conversion board and an emission support board;

The launching support board is provided with the launching board and the launching conversion board;

An emission driving circuit is provided on the emission conversion board for driving the transmitter to emit a laser beam;

The emission mirror is used to change the propagation path of the laser beam;

The emission lens includes one or more spherical lenses.

In one of the embodiments, it further includes a receiving bracket plate, a receiving conversion plate, a receiving reflector, and a receiving lens;

The receiving lens includes one or more spherical lenses;

The receiving mirror is used to change the optical direction of the received laser beam;

The receiving support board is provided with the receiving board and the receiving conversion board;

An operational amplifier circuit is arranged on the receiving conversion board for realizing the amplification of the echo signal.

In one of the embodiments, the receiver includes an avalanche diode, a focal plane array detector, a single-point arrangement or an array arrangement of silicon photomultipliers.

In one of the embodiments, it further includes a main control board; the main control board is electrically connected to the transmitting board, the receiving board and the motor, respectively.

In one of the embodiments, the main control board includes a power supply, a field programmable gate array, a network port chip, and a digital-to-analog converter; the multi-line lidar also includes a microcontroller; the microcontroller and the The field programmable gate array controls the multi-line lidar together.

In one of the embodiments, the transmitter is a fiber laser, a laser diode, a gas laser or a solid laser.

In one of the embodiments, at least one reflecting mirror surface of the rotating prism has a layered structure, and the angle between each layer and the top surface is different, so that the laser beams emitted by the multiple emitters pass through the sub-layers. The layer structure is non-uniformly distributed in the vertical direction.

A multi-line lidar, including:

At least one emitting unit, each of the emitting units includes a emitting board, and the emitting board is integrated with multiple emitters for emitting multiple laser beams;

At least one receiving unit, each of the receiving units includes a receiving board integrated with multiple receivers; the receiving unit and the transmitting unit are arranged in pairs on the same side of the rotating prism, and are located The receiver of the receiving unit on the same side corresponds to the transmitter of the transmitting unit one to one;

The multiple emitters are distributed in a plane in the vertical direction, and the multiple laser beams can be rotated by the rotating prism to achieve the expansion of the number of laser beams in the vertical direction and the horizontal field of view scanning.

In one of the embodiments, the transmitting unit includes a first transmitting unit and a second transmitting unit; the receiving unit includes a first receiving unit and a second receiving unit; the first transmitting unit and the second transmitting unit Are arranged symmetrically with respect to the rotating prism; the first receiving unit and the second receiving unit are arranged symmetrically with respect to the rotating prism, and are arranged in a vertical direction with the corresponding transmitting units and arranged in one-to-one correspondence.

In one of the embodiments, a main control board is further included, and the main control board is electrically connected to the transmitting unit, the receiving unit, and the motor, respectively.

The details of one or more embodiments of the application are set forth in the following drawings and description. Other features and advantages of this application will become apparent from the description, drawings and claims.

Description of the drawings

In order to more clearly describe the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only These are 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 work.

FIG. 1 is a schematic diagram of a first view angle of a multi-line lidar in an embodiment.

Fig. 2 is a cross-sectional view of HH-HH in Fig. 1.

Figure 3 is a cross-sectional view of GG-GG in Figure 1.

Fig. 4 is a schematic cross-sectional view of a rotating prism in an embodiment.

Fig. 5 is a schematic diagram of the principle of a multi-line lidar in an embodiment.

Detailed ways

In order to make the purpose, technical solutions, and advantages of this application clearer, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the application, and are not used to limit the application.

It can be understood that the terms "first", "second", etc. used in this application can be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from another element.

The multi-line lidar provided by this application includes a launch plate, a rotating prism and a motor.

A plurality of emitters are integrated on the emitting board for emitting multiple laser beams; the rotating prism includes a top surface and a bottom surface parallel to each other, and a plurality of mirrored surfaces, and the plurality of emitting mirror surfaces are connected to the top surface. , The bottom surface encloses a hollow shaft, and the included angles between each mirror surface and the top surface are different; the motor is arranged in the hollow shaft of the rotating prism, and is used to drive the rotating prism to rotate; The multiple emitters are distributed in a plane in the vertical direction, and the multiple laser beams can be rotated by the rotating prism to realize the expansion of the number of laser beams in the vertical direction and realize the field of view scanning in the horizontal direction.

The following describes a multi-line lidar realized by a rotating prism with four reflecting mirrors as an example with 2 launching boards, each of which integrates 16 emitters.

Please refer to Figures 1 to 3. Figure 1 is a first view schematic diagram of a multi-line lidar in an embodiment, Figure 2 is a cross-sectional view of HH-HH in Figure 1, and Figure 3 is a cross-sectional view of GG-GG in Figure 1 Figure. The multi-line lidar includes: a first transmitting unit 110, a second transmitting unit 120, a rotating prism 130, a first receiving unit 140, a second receiving unit 150, and a motor 160, wherein the first transmitting unit 110 and the second transmitting unit 120 The first receiving unit 140 and the second receiving unit 150 are also symmetrical with respect to the rotating prism 130.

The first emission unit 110 includes an emission support plate 112, an emission plate 113, an emission conversion plate 114, an emission mirror 115, and an emission lens 116.

The launching support board 112 is provided with a launching board 113 and a launching conversion board 114. Among them, 16 transmitters are integrated on the transmitter board 113 for emitting multiple laser beams (hereinafter referred to as detection signals). It can be understood that in other embodiments, the number of integrated transmitters on the transmitter board 113 can be set according to implementation needs, and there is no limitation here. The transmitters can be, for example, fiber lasers, laser diodes (LD), gas lasers or solid state Lasers, etc. Multiple transmitters are integrated on the launching board 113, so that unified debugging can be achieved, which simplifies the difficulty of debugging.

An emission driving circuit is provided on the emission conversion board 114 for driving the transmitter to emit a laser beam. The emission mirror 115 includes two mirrors for changing the optical direction of the emitted laser beam, so that the structure of the entire first emission unit is more compact. The emission lens 116 includes one or more spherical lenses, and the emitted laser beam passes through the emission lens 116 to reach the target object.

The first receiving unit 140 and the first transmitting unit 110 are arranged on the same side of the rotating prism 130. The first receiving unit 140 includes a receiving support plate 412, a receiving plate 413, a receiving conversion plate 414, a receiving mirror 415, and a receiving lens 416.

The receiving support plate 412 is provided with a receiving plate 413 and a receiving conversion plate 414. Wherein, 16 receivers are correspondingly integrated on the receiving board 413 for receiving multiple laser beams (hereinafter referred to as echo signals). It can be understood that, in other embodiments, the number of integrated receivers on the receiving board 413 can be set according to implementation needs, and there is no limitation here. For example, the receivers can use multiple avalanche diodes (Avalanche PhotoDiodes, arranged in an array). APD), it can also be a single large panel APD, a focal plane array detector, a single-point or array-mounted silicon photomultiplier tube (multi-pixel photon counter, MPPC) detector, or other types known to those skilled in the art Array detector.

An operational amplifier circuit is arranged on the receiving and converting board 414 to realize the amplification of the echo signal. The receiving mirror 415 includes two mirrors for changing the optical direction of the received laser beam, so that the structure of the entire first receiving unit is more compact. The receiving lens 416 includes one or more spherical lenses, and the echo signal reflected by the target object passes through the receiving lens 416 to reach the receiver.

The rotating prism 130 is a tetrahedral structure, including a top surface and a bottom surface parallel to each other, and four reflecting mirror surfaces. The four reflecting mirror surfaces and the top surface and the bottom surface form a hollow axis, and each reflecting mirror surface is connected to the top surface. The angles of the faces are not the same. It can be understood that, in other embodiments, the number of reflecting mirror surfaces of the rotating prism 130 can be set according to actual needs, which is not strictly limited here.

The second transmitting unit 120 has the same structure as the first transmitting unit 110, and the second receiving unit 150 has the same structure as the first receiving unit 140. Therefore, the second transmitting unit 120 and the second receiving unit 150 can refer to the first transmitting unit 110 and the first transmitting unit 110. The description of the receiving unit 140 will not be repeated here.

The motor 160 is arranged in the hollow shaft of the rotating prism 130, as shown in FIG. 4, so that the space can be fully utilized and the volume can be reduced.

The transmitters set on each transmitter board are distributed in a plane in the vertical direction, and the angle between each transmitter's laser emission direction and the horizontal direction is different. The transmitters on different transmitter boards are arranged in a staggered manner. There are 64 lines on the side, and the stacking after the misalignment setting can achieve 128 lines scanning in the vertical direction. The laser beam emitted by each transmitter hits each mirror surface of the rotating prism in turn. Since the angle between each mirror surface and the top surface of the rotating prism 130 is different, in the vertical direction, each laser beam The beams are all expanded into four laser beams; in the horizontal direction, the direction of each laser beam reflected from the rotating prism 130 is different, which also realizes horizontal scanning. The positions and angles of the receivers on each receiving board are in one-to-one correspondence with the transmitters, and detection signals of different angles can only be received by the corresponding receivers. In this way, the number of lines of the laser beam is expanded without increasing the laser light source, and the cost is reduced.

For example, the first emitting unit 110 and the second emitting unit 120 respectively emit 16 laser beams (32 channels in total) with different angles in the vertical direction, and each laser beam passes through the rotating prism to become 4 laser beams in the vertical direction. Therefore, the 32 laser beams become 128 vertical laser beams, and the laser beams emitted by each emitting unit can be scanned horizontally at 150 degrees through the rotating prism. The two emitting units have an overlap area of 90 degrees in the horizontal direction, so In the horizontal direction, the 128-line scan overlap area can reach 90 degrees, and the 64-line scan area on both sides can reach 30 degrees. The two transmitting units and the two receiving units are symmetrically distributed with respect to the rotating prism 130, so that the mass distribution of the entire system structure is uniform and the rotation is more stable.

In one embodiment, the rotating prism 130 includes at least four reflecting mirror surfaces. For any mirror surface, the included angle with the top surface is both greater than the included angle between its two adjacent mirror surfaces and the top surface, or at the same time smaller than the angle between its two adjacent mirror surfaces and the top surface angle.

For example, the clockwise angles of the four reflecting mirror surfaces of the rotating prism 130 with the top surface are marked as ∠1, ∠2, ∠3, and ∠4, where ∠1=90°, ∠2=92°, ∠3 =89°, ∠4=91°. ∠2 is larger than ∠1 and ∠3 at the same time, and ∠3 is smaller than ∠2 and ∠4 at the same time. This setting can make the rotating prism more stable during the rotation process. In other embodiments, the four reflecting mirror surfaces of the rotating prism 130 are clockwise or counterclockwise, and the angles between each reflecting surface and the top surface are 90 degrees, 89.5 degrees, 89.25 degrees, and 89.75 degrees, respectively.

In an embodiment, the maximum value of the included angle between the reflective surface and the bottom surface of the rotating prism 130 is α ₁ and the minimum value is α ₂ , and 0°<|α ₁ -α ₂ |≤3°.

Further, at least one mirror surface of the rotating prism can also be arranged in a layered structure, and the angle between each layer and the top surface is different, so that the laser beams emitted by the multiple emitters can pass through the layered structure. The structure is non-uniformly distributed in the vertical direction, for example, the vertical laser beam is densely distributed in the middle and sparsely distributed up and down.

In an embodiment, the multi-line lidar further includes a photoelectric code disc 170, which is arranged on the rotating prism 130 and used to detect and output angle information of the rotating prism 130 and/or speed information of the motor 160. For example, the photoelectric encoder 170 can output the angle information of the rotating prism 130 and feedback the speed information of the motor 160 in real time to control the speed of the motor 160.

Please refer to FIG. 5, which is a schematic diagram of the principle of a multi-line lidar in an embodiment. The multi-line lidar includes: a first transmitting unit 510, a first receiving unit 520, a rotating prism (not shown in the figure), and a second The transmitting unit 530, the second receiving unit 540, the motor, the photoelectric encoder, and the main control board 180 (the position of the main control board is also shown in Figs. 2 and 3). The main control board 180 is connected to the first transmitting unit 510 and the first transmission unit 510, respectively. A receiving unit 520, a second transmitting unit 530, a second receiving unit 540, a motor, and an optical encoder are electrically connected. Among them, the main control board 180 includes a power supply, a field programmable gate array (Field Programmable Gate Array, FPGA), a network port chip, and an analog-to-digital converter (ADC).

Wherein, the first transmitting unit 510 and the second transmitting unit 530 both include a transmitting lens, an LD, and a transmitting drive circuit, and the first receiving unit 520 and the second receiving unit 540 both include a receiving lens, an APD, and an operational amplifier.

Specifically, the power supply is used to supply power to all modules in the multi-line lidar that require electricity, such as the transmission drive circuit, FPGA, and motor. The FPGA controls the emission drive circuit to drive the LDs on the first emission unit 510 and the second emission unit 530 to emit laser beams in a preset order. The laser beams pass through the emission lens as a detection signal to reach the target object, and the target object will be reflected back. The wave signal arrives on the APD through the receiving lens to achieve photoelectric conversion, and then through the operational amplifier to achieve primary and secondary amplification, and then through the ADC to achieve analog-to-digital conversion into the FPGA, the FPGA will perform operations on the processed echo signal. The result data (such as one or more parameters of the distance, azimuth, height, speed, posture, and shape of the target object) is obtained, and the result data is output in the form of point cloud data through the network port chip. At the same time, FPGA can also control the frequency and power of the laser beam emitted by the LD according to the information fed back from the photoelectric code disc.

Further, in an embodiment, the multi-line lidar may further include a microcontroller unit (MCU), and the MCU and FPGA together control each module of the multi-line lidar.

The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, All should be considered as the scope of this specification.

The above-mentioned embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the scope of the invention patent. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of this application, several modifications and improvements can be made, and these all fall within the protection scope of this application. Therefore, the scope of protection of the patent in this application shall be subject to the appended claims.

Claims

A multi-line lidar, including:

Launch board, integrated with multiple emitters, used to emit multiple laser beams;

The rotating prism includes a top surface and a bottom surface that are parallel to each other and a plurality of mirror surfaces, the plurality of mirror surfaces and the top surface and the bottom surface enclose a hollow shaft, and the angle between each mirror surface and the top surface is not the same;

A motor, arranged in the hollow shaft of the rotating prism, for driving the rotating prism to rotate;

Wherein, the multiple emitters are distributed in a plane in the vertical direction, and the multiple laser beams can be rotated by the rotating prism to achieve the expansion of the number of laser beams in the vertical direction and the horizontal field of view scanning.
The multi-line lidar according to claim 1, wherein the rotating prism includes at least four reflecting mirror surfaces, and for any reflecting mirror surface, the included angle with the top surface is larger than the two adjacent reflection mirror surfaces. The angle between the mirror surface and the top surface, or at the same time, is smaller than the angle between the two adjacent mirror surfaces and the top surface.
The multi-line lidar according to claim 1, wherein the maximum value of the angle between the reflecting surface and the top surface is α 1 , and the angle between the reflecting surface and the top surface is The minimum value is α 2 , 0°<|α 1 -α 2 |≤3°.
The multi-line lidar according to claim 3, wherein the rotating prism includes four reflecting mirror surfaces; in a clockwise or counterclockwise direction, the angles between each reflecting surface and the top surface are 90 degrees and 89.5 degrees, respectively , 89.25 degrees, 89.75 degrees.
The multi-line lidar according to claim 1, further comprising a photoelectric code disc, which is arranged on the rotating prism and used to detect and output the angle information of the rotating prism and the At least one of the speed information of the motor.
The multi-line lidar of claim 1, further comprising a receiving board integrated with multiple receivers, the transmitting board and the receiving board are arranged on the same side of the rotating prism, and the The plurality of receivers correspond to the plurality of transmitters one-to-one.
The multi-line lidar according to claim 6, wherein the multi-line lidar comprises two symmetrically arranged transmitting boards and two symmetrically arranged receiving boards, and each transmitting board corresponds to a receiving board. The same side of the rotating prism.
The multi-line lidar according to claim 6, characterized in that it further comprises a transmitting lens, a transmitting mirror, a transmitting conversion plate and a transmitting bracket plate;

The launching support board is provided with the launching board and the launching conversion board;

An emission driving circuit is provided on the emission conversion board for driving the transmitter to emit a laser beam;

The emission mirror is used to change the propagation path of the laser beam;

The emission lens includes one or more spherical lenses.
The multi-line lidar according to claim 6, further comprising a receiving support plate, a receiving conversion plate, a receiving reflector and a receiving lens;

The receiving lens includes one or more spherical lenses;

The receiving mirror is used to change the optical direction of the received laser beam;

The receiving support board is provided with the receiving board and the receiving conversion board;

An operational amplifier circuit is arranged on the receiving conversion board for realizing the amplification of the echo signal.
The multi-line lidar according to claim 6, wherein the receiver comprises an avalanche diode, a focal plane array detector, a single-point arrangement or an array arrangement of silicon photomultipliers.
The multi-line lidar according to claim 6, further comprising a main control board; the main control board is electrically connected to the transmitting board, the receiving board and the motor, respectively.
The multi-line lidar of claim 11, wherein the main control board includes a power supply, a field programmable gate array, a network port chip, and a digital-to-analog converter; the multi-line lidar also includes a microcontroller ; The microcontroller and the field programmable gate array together control the multi-line lidar.
The multi-line lidar according to claim 1, wherein the transmitter is a fiber laser, a laser diode, a gas laser or a solid laser.
The multi-line lidar according to claim 1, wherein at least one reflecting mirror surface of the rotating prism has a layered structure, and the angle between each layer and the top surface is different, so that the plurality of emission The laser beam emitted by the detector is non-uniformly distributed in the vertical direction when passing through the layered structure.
A multi-line lidar, including:

At least one emitting unit, each of the emitting units includes a emitting board, and the emitting board is integrated with multiple emitters for emitting multiple laser beams;

The rotating prism includes a top surface and a bottom surface that are parallel to each other and a plurality of mirror surfaces, the plurality of mirror surfaces and the top surface and the bottom surface enclose a hollow shaft, and the angle between each mirror surface and the top surface is not the same;

A motor, arranged in the hollow shaft of the rotating prism, for driving the rotating prism to rotate;

At least one receiving unit, each of the receiving units includes a receiving board integrated with multiple receivers; the receiving unit and the transmitting unit are arranged in pairs on the same side of the rotating prism, and are located The receiver of the receiving unit on the same side corresponds to the transmitter of the transmitting unit one to one;

The multiple emitters are distributed in a plane in the vertical direction, and the multiple laser beams can be rotated by the rotating prism to achieve the expansion of the number of laser beams in the vertical direction and the horizontal field of view scanning.
The lidar according to claim 15, wherein the transmitting unit includes a first transmitting unit and a second transmitting unit; the receiving unit includes a first receiving unit and a second receiving unit; the first transmitting unit And the second transmitting unit are arranged symmetrically with respect to the rotating prism; the first receiving unit and the second receiving unit are arranged symmetrically with respect to the rotating prism, and are arranged in a vertical direction with the corresponding transmitting units one by one Corresponding settings.
15. The lidar according to claim 15, further comprising a main control board, and the main control board is electrically connected to the transmitting unit, the receiving unit, and the motor, respectively.
The multi-line lidar according to claim 15, wherein the rotating prism includes at least four reflecting mirror surfaces, and for any reflecting mirror surface, the angle between it and the top surface is larger than the two adjacent reflection mirror surfaces. The angle between the mirror surface and the top surface, or at the same time, is smaller than the angle between the two adjacent mirror surfaces and the top surface.
The multi-line lidar according to claim 18, wherein the rotating prism includes four reflecting mirror surfaces; in a clockwise or counterclockwise direction, the angles between each reflecting surface and the top surface are 90 degrees and 89.5 degrees, respectively , 89.25 degrees, 89.75 degrees.
The multi-line lidar according to claim 15, wherein the main control board includes a power supply, a field programmable gate array, a network port chip, and a digital-to-analog converter; the multi-line lidar also includes a microcontroller ; The microcontroller and the field programmable gate array together control the multi-line lidar.