CN114076929A

CN114076929A - Laser radar system, vehicle and laser radar detection method

Info

Publication number: CN114076929A
Application number: CN202010799054.4A
Authority: CN
Inventors: 杨佳; 王强
Original assignee: Ningbo Sunny Automotive Optech Co Ltd
Current assignee: Ningbo Sunny Automotive Optech Co Ltd
Priority date: 2020-08-11
Filing date: 2020-08-11
Publication date: 2022-02-22

Abstract

The invention discloses a laser radar system, a vehicle with the laser radar system and a laser radar detection method. The laser radar system comprises a transmitting module for transmitting a laser beam, a scanning module for performing two-dimensional scanning on the laser beam and a receiving module with a linear array APD, wherein light reflected by a target is converged on the linear array APD. The invention can effectively avoid stray light, simplify the installation and adjustment process and reduce the cost by using the linear array APD.

Description

Laser radar system, vehicle and laser radar detection method

Technical Field

The invention relates to the field of laser scanning detection, in particular to a laser radar system, a vehicle with the laser radar system and a laser radar detection method.

Background

Lidar systems are a combination of laser technology and radar technology. The laser radar uses laser as a medium and emits the laser to a target object, the target object generates diffuse reflection, and the reflected laser (including physical information such as amplitude, phase and the like) is received by a detector, so that the information such as the distance, the direction and the like of the target object is obtained, and the three-dimensional detection of the surrounding environment is realized. The laser radar has the advantages of active detection, strong anti-interference capability, high detection precision, full-time operation and the like, and is widely applied to the field of automatic driving.

At present, a plurality of transmitting lasers and a plurality of receiving detectors are utilized for realizing multi-line scanning of the common mechanical rotary laser radar, 360-degree scanning of a horizontal view field is realized through a rotary platform, but the scanning frame rate is low, the system structure is complex, the lasers and the detectors need to be debugged independently, the assembly period is long, the cost is high, and the development of the laser radar is limited. Therefore, in order to reduce the cost and volume of the lidar, MEMS lidar has received increasing attention as an innovator of the traditional mechanical lidar, especially in the field of autopilot. The current MEMS laser radar mostly adopts a common optical path optical system, the problem of stray light exists, and the caliber of an MEME micro-mirror is usually small, so that the distance measuring performance is influenced.

Disclosure of Invention

It is therefore an object of the present invention to provide a solution that avoids at least some of the disadvantages of the prior art.

A first aspect of the invention provides a lidar system comprising a transmit module, a first scanning module, a second scanning module, and a receive module. The emitting module is arranged for emitting a laser beam. The first scanning module is arranged for one-dimensional scanning of the laser beam. The second scanning module is arranged for carrying out one-dimensional scanning on the light beam emitted from the first scanning module and projecting the light beam onto a target object, and the scanning directions of the second scanning module and the first scanning module are vertical and combined to form two-dimensional scanning. The receiving module includes a linear array APD (avalanche photodiode), and the light beam reflected by the target is converged on the linear array APD to generate a detection signal.

Therefore, compared with a conventional mechanical laser radar formed by pairing and combining a plurality of lasers/single-point APDs, for example, a 16-line mechanical laser radar is taken as an example, 16 lasers and 16 APDs need to be installed and adjusted in a one-to-one correspondence mode, the process is complex, and the consumed time is long. That is, the present invention can solve the problems of difficult mechanical installation and adjustment and high cost by adopting the linear array APD.

Preferably, the lidar system has a non-common transmitting and receiving path, that is, the projection light of the lidar and the reflection light of the target are not on the same path. For example, in some embodiments of the invention, the second scanning module comprises a first working portion for directing the light beam exiting the first scanning module and a second working portion for receiving the light beam reflected back through the target. The non-common-path scheme formed by the second scanning module can effectively reduce the influence of stray light.

Further, in some embodiments of the present invention, the lidar system may further include a mirror configured to receive the light beam reflected back from the second scanning module, for example, receive the light beam reflected back from the second working portion of the second scanning module, and the light beam reflected back from the mirror may be focused onto the linear array APD. Therefore, compared with the conventional point scanning laser radar which limits the distance measurement capability due to the small aperture of the scanning device, in the embodiments, through the cooperation of the large-aperture second scanning module with the first working part and the second working part and the reflector, the large receiving aperture can be realized, the received echo energy is large, and the distance measurement is long. In addition, in these embodiments, the linear APD and the mirror are adopted to cooperate in the above manner, so that the cost can be greatly reduced compared with the conventional design adopting the area array APD.

In some embodiments of the invention, the emitting module may comprise a single laser or a plurality of lasers for emitting laser pulses or laser beams. For example, where frame rate requirements are low, a single laser may be used to reduce cost; in case of high frame rate requirement, the number of lasers may be increased appropriately to meet the frame rate requirement. Alternatively, the transmitting module may be a multi-channel laser.

In some embodiments of the present invention, the first scanning module and the second scanning module are configured to be rotatable. For example, the first scanning module is configured as a MEMS Micro-mirror (Micro-Electro-Mechanical System), a double-sided mirror, a polygon mirror, and a galvanometer mirror that can rotate about a first axis, for example, a horizontal axis, but the present invention is not limited thereto. Further, the second scanning module is configured to be rotatable about a second axis, e.g., a vertical axis, perpendicular to the first axis. Likewise, the second scanning module may be a MEMS micro-mirror or a double-sided mirror or a polygon mirror or a galvanometer, but the invention is not limited thereto.

In some embodiments of the present invention, the receiving module further includes a receiving mirror group, and the light beam reflected by the target is converged onto the linear array APD by the receiving mirror group to generate the detection signal. Further, when the laser radar system comprises the second scanning module with the first working part and the second working part and the reflector, the light beam emitted from the emitting module forms two-dimensional scanning through the first scanning module and the second scanning module, the light beam projected onto the target object is subjected to diffuse reflection, and as the light path is reversible, a part of the light beam is reflected to the reflector through the second working part of the second scanning module, and the light beam reflected by the reflector is converged onto the linear array APD through the receiving mirror group.

In some embodiments of the invention, the lidar system further comprises a laser shaping module arranged to collimate the laser beam into a parallel beam, the collimated parallel beam being incident on the first scanning module. At this time, the first scanning module performs one-dimensional scanning on the parallel light beams, light reflected by the first scanning module enters the second scanning module to perform one-dimensional scanning, and the first scanning module and the second scanning module are combined to realize two-dimensional scanning.

In some embodiments of the present invention, the lidar system further includes a control analysis module electrically connected to at least the linear array APD, and configured to analyze target information carried by the detection signal.

Further, the control and analysis module may also be electrically connected to the emission module, the first scanning module and the second scanning module to respectively control the emission module to emit the laser beam and control the actions (e.g., rotation) of the first scanning module and the second scanning module. For example, the laser emitting module, the scanning module, etc. may be controlled according to the target object information carried by the detection signal, and in particular, the operation and operating state of the laser emitting module and the scanning module may be automatically adjusted so as to adapt to the change of the target object itself or the change of the target object position and/or distance in real time. This is particularly important for the detection of moving objects.

A second aspect of the invention provides a vehicle comprising a vehicle body and a lidar system arranged in the vehicle body and arranged to scan a target to generate a detection signal. The laser radar system comprises a transmitting module, a first scanning module, a second scanning module and a receiving module. The emitting module is arranged for emitting a laser beam. The first scanning module is arranged for one-dimensional scanning of the laser beam. The second scanning module is arranged for carrying out one-dimensional scanning on the light beam emitted from the first scanning module and projecting the light beam onto a target object, and the scanning directions of the second scanning module and the first scanning module are vertical and combined to form two-dimensional scanning. The receiving module comprises a linear array APD, and light beams reflected by the target object are converged on the linear array APD particularly through a receiving mirror group to generate detection signals. Therefore, the laser radar system can detect external fixed or moving objects when the vehicle runs or parks, and the like, thereby providing corresponding notification or warning information for a vehicle driver and/or providing the vehicle auxiliary driving system or the automatic driving system for decision making.

The lidar system of the vehicle is the lidar system provided above according to the first aspect of the invention. The features and advantages of the lidar system provided in accordance with the first aspect of the invention are equally applicable to the vehicle provided in accordance with the second aspect of the invention.

A third aspect of the present invention provides a laser radar detection method, including:

step one, emitting a laser beam by an emitting module;

step two, the first scanning module carries out one-dimensional scanning on the laser beam;

thirdly, a second scanning module performs one-dimensional scanning on the light beam emitted from the first scanning module and projects the light beam onto a target object, and the second scanning module is vertical to the scanning direction of the first scanning module and is combined with the first scanning module to form two-dimensional scanning;

and step four, converging the light beam reflected by the target object onto the linear array APD to generate a detection signal.

According to some embodiments of the invention, further in step three, the light beam emitted from the first scanning module is directed by the first working part of the second scanning module and projected onto the object; in the fourth step, the second working part of the second scanning module guides the light beam reflected by the target, and the light beam guided and reflected by the second working part of the second scanning module is converged on the linear array APD to generate a detection signal.

In step four, the light beam reflected by the second working portion of the second scanning module is guided by the reflector, and the light beam guided and reflected by the reflector is converged onto the linear array APD to generate a detection signal.

According to some embodiments of the present invention, further in step four, the light beam reflected by the target is focused onto the linear APDs by the receiver array to generate a detection signal.

In addition, the laser radar detection method may further include: and the laser beam is collimated into a parallel beam by the laser shaping module, and the collimated parallel beam enters the first scanning module.

Further, the laser radar detection method may further include: and analyzing the target object information carried by the detection signal by a control analysis module. In this regard, the lidar detection method may further include: and the control analysis module controls the emission module to emit the laser beam and controls the actions of the first scanning module and the second scanning module according to the target object information carried by the detection signal.

The lidar detection method described in the third aspect of the invention may be applied to the lidar system provided in the first aspect of the invention and/or the vehicle provided in the second aspect of the invention. The features and advantages of the lidar system provided according to the first aspect of the invention and of the vehicle provided according to the second aspect of the invention are equally applicable to the lidar detection method provided according to the third aspect of the invention.

Drawings

Embodiments of the invention will be described in more detail below with reference to the accompanying drawings, in which:

FIG. 1 is a schematic diagram of an optical structure of a laser radar with a common transmitting-receiving path in the prior art;

FIG. 2 is a schematic diagram of an optical structure of a laser radar with a non-common transmitting and receiving path in the prior art;

fig. 3 is a schematic view of an optical structure of a laser radar system imaging at a lower end of a linear array APD according to an embodiment of the present invention;

fig. 4 is a schematic view of an optical structure of a laser radar system imaging in the middle of a linear array APD according to an embodiment of the present invention;

fig. 5 is a schematic view of an optical structure of a laser radar system imaging on an upper end of a linear array APD according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram of a laser shaping module according to an embodiment of the present invention;

fig. 7 is a schematic structural diagram of another laser shaping module according to an embodiment of the present invention;

FIG. 8 is a schematic structural diagram of a vehicle according to an embodiment of the present invention;

fig. 9 is a schematic structural diagram of another vehicle according to an embodiment of the present invention.

Fig. 10-12 are schematic flow diagrams of different embodiments of a lidar detection method provided by the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only used for better understanding of the present invention, and are not used for limiting the present invention. All other embodiments, which can be obtained by a person skilled in the art without inventive effort based on the embodiments of the present invention, are within the scope of the present invention.

Throughout the specification, unless otherwise specifically noted, terms used herein should be understood as having meanings as commonly used in the art. Accordingly, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

It should be noted that, in the embodiments of the present invention, the terms "comprises", "comprising" or any other variation thereof are intended to cover a non-exclusive inclusion, so that a method or apparatus including a series of elements includes not only the explicitly recited elements but also other elements not explicitly listed or inherent to the method or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other related elements in a method or apparatus including the element (e.g., steps in a method or elements in an apparatus, such as a part of a circuit, a part of a processor, a part of a program or software, etc.).

It should be noted that the terms "first \ second \ third" related to the embodiments of the present invention only distinguish similar objects, and do not represent a specific ordering for the objects, and it should be understood that "first \ second \ third" may exchange a specific order or sequence when allowed. It should be understood that the terms first, second, and third, as used herein, are interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in other sequences than those illustrated or otherwise described herein. Thus, the first working part described below may also be the second working part, and the second working part may also be the first working part, without departing from the teachings of the present invention.

The existing laser radar is divided into a receiving-transmitting common optical path type and a receiving-transmitting non-common optical path type.

As shown in fig. 1, the laser radar system with a common transmitting-receiving path is that laser projected to a target by the laser radar and laser reflected by the target after diffuse reflection are on the same optical path. In general, a common-path laser radar system emits laser light from a laser light source 1 through an emission lens 2, transmits the laser light through a beam splitter 3, and reflects the laser light through a scanner 4 to project the laser light toward a target object 5 to be measured. After the light is projected to a measured target object 5, laser beams after diffuse reflection is generated on the surface of the target object 5 enter the light splitting device 3 through the same light path, the received reflected laser beams are reflected to the receiving lens 6 by the light splitting device 3, and finally the received reflected laser beams are converted into electric signals by the laser detector 7. The receiving and transmitting common-path laser radar has the problem of stray light, is generally limited by the caliber of a scanning device, has a small diameter of an entrance pupil of a receiving optical path, and can only receive a reflected light signal with a small caliber, so that the detection distance is short. In addition, the detection precision of the receiving and transmitting common-path laser radar system is limited by the angle resolution capability of a scanning device, the angle resolution is low, and the normal use requirement cannot be met.

As shown in fig. 2, 1 'denotes a laser, 2' denotes an emission lens, 4 'denotes a scanning device, 5' denotes an object, 6 'denotes a reception lens, and 7' denotes a detector. The system adopts a non-common optical path mode, so that an area array APD is required to be used as a detector, but the cost of the area array APD is high, and the subsequent development of the laser radar is influenced.

Accordingly, to address at least one of the problems of mechanical setup difficulty, high cost, small range distance, and stray light interference, the present invention provides an improved lidar system 100, as shown in fig. 3-5. Lidar system 100 includes a transmit module 111 (e.g., a laser), a first scanning module 113, and a second scanning module 114 at a transmit end 110. The emitting module 111 is configured to emit a laser beam, the first scanning module 113 is configured to perform one-dimensional scanning on the laser beam, and the second scanning module 114 is configured to perform one-dimensional scanning on the beam emitted from the first scanning module 113 and project the beam onto the target 200. The second scanning module 114 is perpendicular to the scanning direction of the first scanning module 113 and forms a two-dimensional scan in combination.

Lidar system 100 includes a receiving module at receiving end 120, which includes a photodetector 121, and a light beam reflected by target 200 is focused on photodetector 121 to generate a detection signal.

The photodetector 121 is preferably a linear APD121, so that the problems of difficulty in mechanical installation and adjustment and high cost can be solved.

In addition, lidar system 100 includes a laser shaping module 112, such as a collimating lens, at a transmitting end 110 configured to collimate the laser beam into a parallel beam. The laser shaping module 112 is disposed between the emitting module 111 and the first scanning module 113 along the propagation direction of the laser beam, the laser beam emitted from the emitting module 111 is changed into a parallel beam by the laser shaping module 112, the parallel beam is one-dimensionally scanned by the first scanning module 113 and projected to the second scanning module 114, and the second scanning module 114 performs one-dimensional scanning again after receiving the laser beam.

As shown in fig. 6, the laser shaping module 112 may include a single lens. Alternatively, as shown in fig. 7, the laser shaping module 112 may include two cylindrical lenses, a first cylindrical lens 1121 and a second cylindrical lens 1122, which are disposed perpendicular to each other.

Further, the lidar system 100 further includes a receiving mirror group 122 at the receiving end 120, and the light beam reflected by the target 200 is converged onto the linear array APD121 through the receiving mirror group 122 to generate a detection signal.

In the embodiment of the present invention, the first and

second scanning modules

113 and 114 are configured to be rotatable. As shown in fig. 3 to 5, the first scanning module 113 is configured to be rotatable about a horizontal axis H, and the second scanning module 114 is configured to be rotatable about a vertical axis V perpendicular to the horizontal axis H. For example, the first scanning module 113 is a rotatable MEMS micro-mirror, and the second scanning module 114 is a double-sided mirror.

Preferably, lidar system 100 has a transmit-receive non-common optical path. As shown in fig. 3 to 5, the second scanning module 114 includes a first working portion 1141 and a second working portion 1142. The first working portion 1141 is used as a part of the emitting end 110 to guide the light beam emitted from the first scanning module 113, and the second working portion 1142 is used as a part of the receiving end 120 to receive the light beam reflected by the target, so that the non-common path scheme can reduce the influence of stray light.

Further, the lidar system 100 further includes, at the receiving end 120, a mirror 123 disposed between the second working portion 1142 of the second scanning module 114 and the receiving mirror group 122, and the mirror is configured to receive the light beam reflected by the second scanning module 114, for example, the light beam reflected by the second working portion 1142 of the second scanning module 114, and the laser light beam reflected by the mirror is guided to converge on the linear array APD through the receiving mirror group 122. Therefore, by using a non-common optical path scheme consisting of the linear array APD, the double scanning module and the reflecting mirror, the aperture of the light can be effectively improved, the distance measurement distance can be increased, and meanwhile, the influence of stray light is reduced.

In one specific example, the emitting module 111 is configured as a four-channel laser, and the four channels can emit laser light independently in sequence and be collimated by a single shaping lens 112, and the shaping form is as shown in fig. 6. The collimated beam is incident on a first scanning module 113, and the first scanning module 113 rotates about a horizontal axis H and provides a 16 ° field of view scan in the vertical axis direction. The light beam reflected by the first scanning module 113 is incident on the second scanning module 114, which is divided into an upper working area and a lower working area, i.e., a first working portion 1141 and a second working portion 1142. The upper working area 1141 is used to reflect the light beam emitted from the first scanning module 113, and the lower working area 1142 is used to receive the echo light beam, i.e. the light beam reflected by the target 200. The second scanning module 114 rotates about a vertical axis V and provides a field scan of 70 ° in the horizontal direction with a horizontal angular resolution of 0.2 °. After the scanning light beam emitted from the upper working area 1141 is diffusely reflected by the target 200, part of the light beam returns along the original path, and after the scanning light beam is reflected by the lower working area 1142 of the second scanning module 114, the reflected light beam is incident to the reflective mirror 123, and the light beam reflected by the reflective mirror 123 is converged on the linear array APD through the receiving lens 122. In this example, the number of pixels of the linear array APD is 16, so the vertical axis view angle resolution is 1 °, the frame rate of the whole laser radar is 15Hz, and the amount of point cloud data per second is 70/0.2 × 16 × 15 — 84K, which can meet the repetition frequency requirement of the laser.

In another specific example, the emitting module 112 is also composed of a four-channel laser, and the single channel can emit laser light independently to perform beam collimation through two cylindrical lenses vertically arranged with each other, and the collimation form is as shown in fig. 7. The collimated beam is incident on a first scanning module 113, and the first scanning module 113 rotates about a horizontal axis H and provides a 20 ° field of view scan in the vertical axis direction. The light beam reflected by the first scanning module 113 is incident on the second scanning module 114, which is divided into an upper working area and a lower working area, i.e., a first working portion 1141 and a second working portion 1142. The upper working area 1141 is used to reflect the light beam emitted from the first scanning module 113, and the lower working area 1142 is used to receive the echo light beam, i.e. the light beam reflected by the target 200. The second scanning module 114 rotates about a vertical axis V and provides a field scan in a horizontal direction of 50 ° with a horizontal angular resolution of 0.1 °. After the scanning light beam emitted from the upper working area 1141 is diffusely reflected by the target 200, part of the light beam returns along the original path, and after the scanning light beam is reflected by the lower working area 1142 of the second scanning module 114, the reflected light beam is incident to the reflective mirror 123, and the light beam reflected by the reflective mirror 123 is converged on the linear array APD through the receiving lens 122. In this example, the number of pixels of the linear array APD is 8, so the vertical axis view angle resolution is 2.5 °, the frame rate of the whole laser radar is 20Hz, and the amount of point cloud data per second is 50/0.1 × 8 × 20 — 80K, which can meet the re-frequency requirement of the laser.

In fig. 3, 4 and 5, θ is an angle between the light ray and the horizontal line, and represents the exit direction of the light ray. If the emergent ray is above the horizontal line, the image is formed at the lower end of the linear array APD, as shown in FIG. 3; if the emergent ray is parallel to the horizontal line, the image is formed in the middle of the linear array APD, as shown in FIG. 4; if the emergent ray is below the horizontal line, the image is formed at the upper end of the linear array APD, as shown in FIG. 5.

In addition, lidar system 100 includes a control analysis module that is not shown in the figures. The control analysis module may be electrically connected to the transmission module 111, the first scanning module 113, the second scanning module 114, and the line APD 121. The control and analysis module may be configured to control the transmitting module 111 to transmit the laser beam, control the rotation of the first scanning module 113 and the second scanning module 114, acquire the detection signal from the linear array APD, and then analyze the target information carried by the detection signal. For example, the linear array APD converts an optical signal into an electrical signal, and the control analysis module may analyze and process target information carried by the electrical signal and control the laser emitting end, the scanning module, and the like according to information content.

The control analysis module may include, for example, a processor and a memory. The processor may be a CPU, GPU or other chip with computing capabilities. The memory is loaded with various computer programs such as an operating system and an application program for execution by the processor, and data required for executing the computer programs, such as detection signals acquired from the linear array APD and target information obtained by analysis.

As shown in fig. 8 and 9, an embodiment of the present invention further provides a vehicle including a vehicle body 300 and the laser radar system 100 described above mounted on the vehicle body 300. The lidar system 100 is configured to detect a target 200 around a vehicle body 300, for example, to detect an obstacle (including a fixed or moving target, such as a pedestrian, a vehicle, or other traffic participant) in front of, to the side of, or to the rear of the vehicle body 300. The detection information detected by the lidar system 100 is transmitted to a vehicle control unit, which calculates the spatial or relative position of the target object 200 based on the detection information for further use by the vehicle, for example in reversing or for indicating the presence of an obstacle.

As shown in fig. 8, components of transmitting end 110 of laser radar system 100 are disposed at an upper portion of vehicle body 300, for example, a roof of a vehicle, so as to form a large scanning field of view. The components of transmitting end 120 of lidar system 100 are also disposed in the upper portion of vehicle body 300. It is to be understood that the installation location of lidar system 100 shown in fig. 8 is exemplary only, and not limiting. Therefore, lidar system 100 may also be mounted at other locations of vehicle body 300 to detect targets in other spaces in the vicinity of the vehicle. For example, laser radar system 100 may be mounted to the rear of vehicle body 300 to detect objects behind vehicle body 300 and provide vehicle occupants with an indication of the objects behind the vehicle. Alternatively, as shown in fig. 9, the laser radar system 100 may be mounted on the front portion of the vehicle body 300, and the detection field of view of the laser radar system 100 may be formed in front of the vehicle without affecting the normal running of the vehicle. Of course, it is also contemplated that lidar system 100 may be mounted to the side of vehicle body 300 as may be desired and practical, and the invention is not particularly limited in this regard.

As shown in fig. 10, an embodiment of the present invention further provides a laser radar detection method 1000, where the laser radar detection method includes:

step one S1100, a laser beam is emitted by an emitting module 111, wherein the emitting module 111 is a laser for example;

step two S1200, the first scanning module 113 performs one-dimensional scanning on the laser beam;

step three S1300, the second scanning module 114 performs one-dimensional scanning on the light beam emitted from the first scanning module 113 and projects the light beam onto the target object 200, wherein the second scanning module 114 is perpendicular to the scanning direction of the first scanning module 113 and is combined with the scanning direction of the first scanning module 113 to form two-dimensional scanning;

step four S1400, converging the light beam reflected by the target 200 onto the linear array APD121 to generate a detection signal.

As shown in fig. 11, step three S1300 may include, according to some embodiments of the invention: the light beam emitted from the first scanning module 113 is guided by the first working part 1141 of the second scanning module 114 and projected onto the target 200; accordingly, step four S1400 may include:

1410, the light beam reflected back from the target 200 is directed by the second working portion 1142 of the second scanning module 114,

s1420, the light beam guided and reflected by the second working portion 1142 of the second scanning module 114 is focused on the linear APD121 to generate a detection signal.

Further, as shown in fig. 12, regarding step four, the above-described step S1420 may include:

s1421, the light beam reflected by the second working portion 1142 of the second scanning module 114 is guided by the mirror 123,

s1422, the light beam reflected by the mirror 123 is focused on the linear APD121 to generate a detection signal.

Further specifically, step four S1400 may include: the light beam reflected by the target 200 is focused on the linear array APD121 by the receiving mirror group 122 to generate a detection signal.

Further specifically, regarding step four, particularly for the case where a set of receiving mirrors is provided, the above-mentioned step S1420/S1422 may include: the light beam guided and reflected by the reflecting mirror 123 is converged on the linear array APD121 through the receiving mirror group 122 to generate a detection signal.

In some embodiments, the method may further comprise the steps not shown: the laser beam is collimated into a parallel beam by the laser shaping module 112, and the collimated parallel beam is incident to the first scanning module 113.

In a further embodiment, the method may further comprise the steps not shown: and analyzing the target object information carried by the detection signal by the control analysis module. In this regard, the method may further include: and the control analysis module controls the emission module to emit the laser beam and controls the actions (such as rotation) of the first scanning module and the second scanning module according to the target object information carried by the detection signal.

Other embodiments and advantages of the lidar detection method 1000 provided by the present invention can be referred to the related descriptions of the lidar system 100 and the vehicle provided by the embodiments of the present invention, and are not repeated herein.

The features or combinations of features mentioned above in the description, in the drawings and in the claims can be used in any combination with one another or alone, provided that they are meaningful and not mutually contradictory within the scope of the invention. The advantages and features explained for the lidar system provided by the embodiments of the invention apply in a corresponding manner to the vehicle and the lidar detection method provided by the embodiments of the invention, and vice versa.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by the contents of the present specification and the accompanying drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. A lidar system, comprising:

the emitting module is used for emitting laser beams;

the first scanning module is used for carrying out one-dimensional scanning on the laser beam;

the second scanning module is used for carrying out one-dimensional scanning on the light beam emitted from the first scanning module and projecting the light beam onto a target object, and the second scanning module is vertical to the scanning direction of the first scanning module and combined with the first scanning module to form two-dimensional scanning;

and the receiving module comprises a linear array APD, and the light beam reflected by the target is converged on the linear array APD to generate a detection signal.

2. The lidar system of claim 1, wherein the second scanning module comprises a first working portion configured to direct the beam exiting the first scanning module and a second working portion configured to receive the beam reflected off of the target.

3. The lidar system of claim 2, further comprising a mirror configured to receive the light beam reflected off the second working portion of the second scanning module, wherein the light beam reflected off the mirror is focused onto the linear array APDs.

4. Lidar system according to any of claims 1 to 3, wherein the transmitting module comprises a plurality of lasers or wherein the transmitting module is a multi-channel laser.

5. The lidar system according to any of claims 1 to 4, wherein the first scanning module and/or the second scanning module is configured as a rotatable MEMS micro-mirror or a double-sided mirror or a polygon mirror or a galvanometer.

6. The lidar system according to any of claims 1 to 5, wherein the receiving module further comprises a receiving mirror group, and light beams reflected by the target object are converged onto the linear array APDs by the receiving mirror group to generate detection signals.

7. The lidar system of any of claims 1 to 6, further comprising a laser shaping module configured to collimate the laser beam into a parallel beam, the collimated parallel beam being incident on the first scanning module.

8. The lidar system of any of claims 1 to 7, further comprising a control and analysis module electrically connected to the linear APDs and configured to analyze target information carried by the detection signals.

9. The lidar system of claim 8, wherein the control and analysis module is electrically connected to the transmitter module, the first scanning module, and the second scanning module to control the transmitter module to transmit the laser beam and to control the operation of the first scanning module and the second scanning module, respectively.

10. The lidar system of claim 9, wherein the control and analysis module controls the transmission module and the first and second scanning modules based on target information carried by the detection signal.

11. A vehicle, characterized in that the vehicle comprises: a vehicle body and a lidar system according to any of claims 1 to 10 arranged in the vehicle body and arranged for scanning a target to generate a detection signal.

12. A lidar detection method, comprising:

step one, emitting a laser beam by an emitting module;

13. The lidar detection method of claim 12,

in step three, the first working part of the second scanning module guides and projects the light beam emitted from the first scanning module onto a target object;

in the fourth step, the second working part of the second scanning module guides the light beam reflected by the target, and the light beam guided and reflected by the second working part of the second scanning module is converged on the linear array APD to generate a detection signal.

14. The lidar detection method of claim 13, wherein in step four, the light beam reflected from the second working portion of the second scanning module is guided by a mirror, and the light beam guided and reflected by the mirror is focused onto the linear APDs to generate the detection signal.

15. The lidar detection method according to any of claims 12 to 14, wherein in step four, the light beam reflected by the target is focused by a receiver group onto the linear array APDs to generate a detection signal.

16. The lidar detection method of any of claims 12 to 15, further comprising:

and the laser beam is collimated into a parallel beam by the laser shaping module, and the collimated parallel beam enters the first scanning module.

17. The lidar detection method of any of claims 12 to 16, further comprising:

and analyzing the target object information carried by the detection signal by a control analysis module.

18. The lidar detection method of claim 17, further comprising:

and the control analysis module controls the emission module to emit the laser beam and controls the actions of the first scanning module and the second scanning module according to the target object information carried by the detection signal.