CN115113171A - A multi-line lidar and its data point cloud processing method - Google Patents

Abstract

The invention relates to a multi-line laser radar and a data point cloud processing method thereof. The multi-line laser radar comprises a rotatable rotating base and a plurality of laser transmitting and receiving modules arranged on the rotating base along the circumferential direction. The laser emission and reception module includes: a laser emission array, which includes a plurality of laser transmitters arranged in an array, the laser transmitters are used to emit outgoing laser light, and the outgoing laser light is reflected by the detection target to generate reflected laser light; and laser detection an array, which includes a plurality of laser detectors arranged in an array, the laser detectors are used for receiving reflected laser light, wherein, between the plurality of laser emission arrays included in the plurality of laser emission and receiving modules, along the circumferential direction The plurality of laser emitters arranged correspondingly have different emission angles, respectively. The multi-line laser radar and the data point cloud processing method of the invention can improve the detection accuracy of the multi-line laser radar.

Description

A multi-line lidar and its data point cloud processing method

technical field

The present invention generally relates to the field of laser technology. More specifically, the present invention relates to a multi-line laser radar and a data point cloud processing method thereof.

Background technique

With the continuous development of laser technology, laser technology has been continuously used in all aspects of life, such as laser measurement. The basic principle of lidar is to emit a laser beam to the target detection object, and then receive the reflected beam, and determine the distance from the lidar to the target detection object by calculating the round-trip time of the laser. Multi-line LiDAR obtains information such as the distance, height, speed, shape and size of the target detection object by emitting multiple laser beams and comparing the received reflected beams.

At present, multi-line lidar is widely used to detect target detection objects. For multi-line lidar, the detection accuracy is related to the number of laser beams of lidar, but the number of laser beams of lidar will be affected by the volume of lidar. limits. Therefore, the traditional multi-line lidar generally has the problem of low accuracy or large volume. In addition, the point cloud data of the traditional multi-line lidar is modeled for each laser emitting light source as the center, so the accuracy of the point cloud data obtained by modeling is low.

Therefore, it is necessary to develop a multi-line laser radar with high precision and small volume to improve the problems of low precision and large volume in traditional multi-line laser radar; and make the obtained point cloud information of the detected object data. High precision.

SUMMARY OF THE INVENTION

In order to solve one or more technical problems mentioned above, the present invention provides a multi-line laser radar and a data point cloud processing method thereof, so as to improve the problems of poor detection accuracy and large volume of traditional multi-line laser radar.

In a first aspect, an exemplary embodiment of the present invention provides a multi-line laser radar, which may include a rotatable rotating base and a plurality of laser transmitting and receiving modules circumferentially disposed on the rotating base , the laser emitting and receiving module may include: a laser emitting array, which includes a plurality of laser emitters arranged in an array, the laser emitters are used to emit outgoing laser light, and the outgoing laser light is reflected by the detection target to generate reflected laser light; and laser light A detection array, which includes a plurality of laser detectors arranged in an array, the laser detectors are used to receive reflected laser light, wherein, between the plurality of laser emission arrays included in the plurality of laser emission and reception modules, along the circumferential direction The plurality of laser emitters arranged in corresponding directions may respectively have different emission angles.

In an exemplary embodiment, among the plurality of laser emitting arrays included in the plurality of laser emitting and receiving modules, the plurality of laser emitters correspondingly arranged along the circumferential direction may have different heights, respectively.

In an exemplary embodiment, the number of the laser detectors may be the same as the number of the laser emitters, and the plurality of laser detectors may respectively have a one-to-one correspondence with the plurality of laser emitters angle and height.

In an exemplary embodiment, all of the laser emitters may have different firing angles.

In an exemplary embodiment, the laser transmitting and receiving module may further include: an optical receiving structure including a receiving lens, the receiving lens is used to collect the reflected laser light and make the collected reflected laser light incident on the corresponding laser detector and/or an optical exit structure comprising a transmitting lens arranged around the receiving lens and for collecting exit laser light emitted by the laser transmitter.

In an exemplary embodiment, the optical exit structure may include at least four transmitting lenses, and the optical receiving structure may include at least one receiving lens, wherein the at least four transmitting lenses may be arranged on the receiving lens side.

In an exemplary embodiment, the plurality of laser transmitting and receiving modules may include: a first laser transmitting and receiving module, a second laser transmitting and receiving module, a third laser transmitting and receiving module, and a fourth laser transmitting and receiving module The module, wherein the first laser transmitting and receiving module and the third laser transmitting and receiving module are in a center-symmetric structure, the second laser transmitting and receiving module and the fourth laser transmitting and receiving module are in a center-symmetric structure, and the first laser transmitting and receiving module is in a center-symmetric structure. The module and the second laser transmitting and receiving module are in an axisymmetric structure, and the third laser transmitting and receiving module and the fourth laser transmitting and receiving module are in an axisymmetric structure.

In an exemplary embodiment, the laser emitting array may further include a emitting plate on which a plurality of laser emitters arranged in an array are arranged, and the laser detection array may further include a receiving plate, which is arranged in an array. A plurality of laser detectors are arranged on the receiving board.

In an exemplary embodiment, the laser emission array may further include a light source driving device and at least four laser emitters electrically connected to the light source driving device; the laser detection array may further include a signal processing device and a The signal processing device is electrically connected to at least four laser detectors; and the laser detectors may correspond to the laser transmitters in one-to-one correspondence.

In an exemplary embodiment, the multi-line laser radar may further include a motor, a top plate and a light blocking plate, the motor is connected with the rotating base, so that the rotating base is driven by the motor to rotate; the top plate is provided with above the laser transmitting and receiving modules; and the light blocking plate is arranged between the plurality of laser transmitting and receiving modules to separate the plurality of laser transmitting and receiving modules.

In an exemplary embodiment, the multi-line lidar may further include a control device connected with the motor to control the rotation of the rotating base through the motor.

In an exemplary embodiment, the multi-line lidar may further include an azimuth detection device configured to determine the azimuth of the target, including: determining the round-trip time T of the laser light between the target and the lidar; determining a first included angle α between the laser and a predetermined plane in a predetermined coordinate system; determining a rotation angle β of the laser emitter with the rotating base; and according to the round-trip time T, the laser emitter is in the The position in the predetermined coordinate system, the first included angle α and the rotation angle β are used to determine the orientation of the target.

In a second aspect, an exemplary embodiment of the present invention provides a data point cloud processing method for the multi-line lidar described in the first aspect and various embodiments thereof, the method may include: determining where the laser is determine the round-trip time T between the target and the lidar; determine the first angle α between the laser and the predetermined plane under the predetermined coordinate system; determine the rotation angle β of the laser transmitter with the rotating base; and according to The round-trip time T, the position of the laser transmitter in the predetermined coordinate system, the first included angle α and the rotation angle β are used to determine the orientation of the target.

As described above, the laser radar according to the exemplary embodiment of the present invention may arrange a plurality of laser transmitting and receiving modules on the rotating base, and the plurality of laser transmitters included in these laser transmitting and receiving modules may have different emission angles , so the number of pixels on the detection target can be increased, so that the resolution of the lidar can be significantly improved.

In addition, the lidar of the exemplary embodiment of the present invention can increase the number of laser transmitters without increasing the laser transmitter and receiver modules by setting the plurality of laser transmitters included in the plurality of laser transmitter and receiver modules to have different heights. Therefore, the lidar of the present invention can improve the resolution of the lidar without increasing the overall height of the lidar, thereby reducing the volume of the lidar.

In addition, the multi-line laser radar and its data point cloud processing method of the present invention can use the rotation axis of the laser radar as the z-axis to establish a three-dimensional rectangular coordinate system, so that the pixel points generated by the multiple laser transmitting and receiving modules of the laser radar can be It is calculated in the same predetermined coordinate system, and the data point cloud of the detection target can be drawn in the same predetermined coordinate system. Therefore, the multi-line laser radar and the data point cloud processing method of the present invention can improve the detection accuracy of the laser radar.

Description of drawings

The above and other objects, features and advantages of exemplary embodiments of the present invention will become readily understood by reading the following detailed description with reference to the accompanying drawings. In the accompanying drawings, several embodiments of the present invention are shown by way of example and not limitation, and like or corresponding reference numerals refer to like or corresponding parts, wherein:

FIG. 1 is a schematic diagram illustrating a multi-line lidar according to an exemplary embodiment of the present invention;

2 is a schematic diagram illustrating a laser emission array of a multi-line lidar according to an exemplary embodiment of the present invention;

3 is a schematic diagram illustrating an equivalent layout of a laser transmitter of a multi-line lidar according to an exemplary embodiment of the present invention;

4 is a schematic diagram illustrating a laser emission array of a multi-line lidar according to another exemplary embodiment of the present invention;

5 is a schematic diagram illustrating a laser emission array of a multi-line lidar according to yet another exemplary embodiment of the present invention;

6 is a schematic diagram illustrating an optical output structure and an optical reception structure of a multi-line lidar according to an exemplary embodiment of the present invention;

FIG. 7 is a schematic diagram illustrating the measurement of a target detection object by a multi-line lidar according to an exemplary embodiment of the present invention; and

FIG. 8 is a flowchart illustrating a data point cloud processing method of a multi-line lidar according to an exemplary embodiment of the present invention.

Detailed ways

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. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present invention.

It should be understood that the terms "first", "second", "third" and "fourth" in the claims, description and drawings of the present invention are used to distinguish different objects, rather than to describe a specific order . The terms "comprising" and "comprising" used in the description and claims of the present invention indicate the presence of the described features, integers, steps, operations, elements and/or components, but do not exclude one or more other features, integers , step, operation, element, component and/or the presence or addition of a collection thereof.

It should also be understood that the terminology used in this specification of the present invention is for the purpose of describing particular embodiments only, and is not intended to limit the present invention. As used in the present specification and claims, the singular forms "a," "an," and "the" are intended to include the plural unless the context clearly dictates otherwise. It will be further understood that, as used in the present specification and claims, the term "and/or" refers to and including any and all possible combinations of one or more of the associated listed items.

As used in this specification and in the claims, the term "if" may be contextually interpreted as "when" or "once" or "in response to determining" or "in response to detecting". Similarly, the phrases "if it is determined" or "if the [described condition or event] is detected" may be interpreted, depending on the context, to mean "once it is determined" or "in response to the determination" or "once the [described condition or event] is detected. ]" or "in response to detection of the [described condition or event]".

Multi-line LiDAR is a kind of LiDAR. It uses multiple laser transmitters to emit laser light to detect the position, speed and other characteristics of the target. Its working principle is to first emit laser light to the target, and then receive the reflected light from the detection target Information about the target can be obtained by reflecting the laser light and comparing it with the outgoing laser light.

At present, the traditional multi-line lidar usually sets multiple laser transmitters and multiple laser detectors on the transmitting board and the receiving board respectively, and uses the outgoing lasers emitted by the multiple laser transmitters for detection, thereby realizing multi-line laser detection. . However, the number of lines of the multi-line lidar determines the detection accuracy of the lidar. The way to increase the number of lines is usually only to increase the number of laser transmitters on the emission board, and increasing the number of laser transmitters will increase the emission board and the corresponding optical The volume of the structure, thereby increasing the volume of the lidar.

In addition, increasing the number of laser emitters on the emission board will increase the density of laser emitters, thereby increasing the difficulty of debugging the laser emitters. Therefore, the method of simply increasing the number of laser transmitters to increase the number of lines will be limited by the volume of the entire lidar and the difficulty of debugging the angle of the lidar, which makes it difficult to improve the detection accuracy of the lidar.

In view of the above problems, an exemplary embodiment of the present invention provides a multi-line laser radar, the multi-line laser radar may include at least one rotating base and at least two laser transmitting and receiving modules arranged on the rotating base. The emission module may include: a laser emission array, a laser detection array, an optical output structure and an optical reception structure, wherein the laser emission array may include: a receiving plate, a laser transmitter and a collimating cylinder, and the laser detection array may include: a receiving plate and a laser detector.

The multi-line laser radar of the present invention can use a plurality of laser transmitters arranged at different angles and different positions in the vertical direction to emit outgoing laser light. Reflection occurs after encountering the detection target to generate reflected laser light. The reflected laser light is condensed by the receiving lens, and detected by the laser detectors arranged at different angles and positions in the vertical direction and corresponding to the laser emitters one-to-one.

Further, the multi-line laser radar of the present invention determines the laser beam information related to ranging through the timing unit and the azimuth detection device, so that the three-dimensional data point cloud information of the detection target relative to the rotation axis of the laser radar can be calculated. The multi-line laser radar of the present invention can not only effectively improve the resolution of the multi-line laser radar and have a smaller overall volume, but also can calculate and process the three-dimensional data point cloud information of the detection target more accurately.

The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a schematic diagram illustrating a lidar according to an exemplary embodiment of the present invention.

As shown in FIG. 1 , an exemplary embodiment of the present invention provides a lidar, which may include: a rotatable rotating base 100 and a plurality of laser transmitting and receiving lasers disposed on the rotating base 100 in a circumferential direction Module 200. Specifically, the laser emitting and receiving module 200 may include: laser emitting arrays 210a-210d, which include a plurality of laser emitters 211 arranged in an array, the laser emitters 211 are used to emit outgoing laser light, and the outgoing laser light is reflected by the detection target to generate reflected laser light ; and a laser detection array 220a-220d, which includes a plurality of laser detectors 221 arranged in an array, the laser detectors 221 for receiving reflected laser light.

Specifically, as shown in FIG. 1, the above-mentioned laser emission arrays 210a-210d may include a plurality of laser transmitters 211, and the plurality of laser transmitters 211 may emit outgoing laser light toward the outside of the lidar, and the outgoing laser light encounters a detection target The reflected laser light is generated by reflection, and the reflected laser light can be received by the laser detectors 221 on the laser detection arrays arranged in the vicinity of the laser emission arrays 210a-210d, whereby laser detection can be realized.

FIG. 2 is a schematic diagram illustrating a laser emission array of a multi-line lidar according to an exemplary embodiment of the present invention.

As further shown in FIG. 2, each of the plurality of laser emission arrays 210a-210d includes a plurality of laser transmitters 211 spaced apart along a first direction, the first direction being parallel to the axis of rotation of the lidar. In particular, in the embodiment shown in FIG. 2 , the first direction is the vertical direction in FIG. 2 .

In particular, as shown in FIG. 2 , among the multiple laser emitting arrays 210 a - 210 d included in the multiple laser emitting and receiving modules 200 , the multiple laser emitters 211 correspondingly arranged along the circumferential direction may have different launch angle. Here, the emission angle refers to the included angle between the outgoing laser light emitted by the laser transmitter 211 and the first plane, where the first plane is a plane perpendicular to the rotation axis of the lidar.

Specifically, in FIG. 2 , a plurality of laser emitting arrays 210a-210d included in the plurality of laser emitting and receiving modules 200 are shown side by side, wherein the plurality of laser emitting arrays 210a-210d correspond to each other along the circumferential direction The arranged plurality of laser emitters 211 is shown in FIG. 2 as four laser emitters 211 arranged correspondingly in the lateral direction. As shown in the figure, FIG. 2 shows a total of multiple laser emitters 211 arranged in four rows correspondingly, each row includes four laser emitters, and the four laser emitters in each row may have different emission angles respectively . It can be understood that, such an arrangement can make a plurality of laser emitters 211 correspondingly arranged in the circumferential direction generate one pixel on the detection target when the lidar rotates, thereby increasing the number of pixels generated on the detection target. number of points.

Therefore, it can be understood that the multi-line lidar of the present disclosure can be realized when the lidar rotates by setting the plurality of laser transmitters correspondingly arranged along the circumferential direction on the plurality of laser emission arrays to have different emission angles respectively. The scanning ranging under the 360° field of view can increase the number of pixels that are incident on the detection target, thereby improving the resolution of the lidar.

Further, with continued reference to FIG. 2 , in an exemplary embodiment, among the plurality of laser emitting arrays 210 a - 210 d included in the plurality of laser emitting and receiving modules 200 , a plurality of laser beams arranged correspondingly along the circumferential direction The transmitters 211 may have different heights, respectively.

Specifically, similar to the above-mentioned emission angles, as shown in FIG. 2 , a total of four laser emitters 211 are shown correspondingly arranged in four rows, and each row includes four laser emitters 211 . The four laser emitters 211 may have different heights, respectively. Here, it can be understood that the height is the height in the vertical direction in FIG. 2 , and the vertical direction is parallel to the rotation axis of the multi-line lidar.

Therefore, it can be understood that the above arrangement can make a plurality of laser emitters 211 correspondingly arranged in the circumferential direction generate one pixel on the detection target under the circumstance that the lidar rotates, so that the pixels generated on the detection target can be increased. number of points.

In addition, it can be understood that, although the embodiment shown in FIG. 2 includes a plurality of laser emitters 211 arranged in four rows correspondingly, and each row includes four laser emitters 211, this arrangement is only for this purpose. Disclosed preferred embodiments. Regarding the number of rows and the number of laser emitters included in each row, those skilled in the art can select different numbers of rows and the number of laser emitters included in each row according to application scenarios, which are not limited in the present disclosure.

Further, in an exemplary embodiment, all the laser emitters may have different emission angles. In other words, each of all the laser transmitters included in the multi-line lidar of the present disclosure may have different emission angles. This arrangement enables each laser emitter 211 to generate one pixel on the detection target, thereby further increasing the number of pixels generated on the detection target.

In an exemplary embodiment, as shown in FIG. 1 , the multi-line laser radar of the present invention may exemplarily include four laser transmitting and receiving modules 200, and the above four laser transmitting and receiving modules 200 may include: a first The laser transmitting and receiving module 200a, the second laser transmitting and receiving module 200b, the third laser transmitting and receiving module 200c and the fourth laser transmitting and receiving module 200d. Specifically, the first laser transmitting and receiving module 200a and the third laser transmitting and receiving module 200c have a center-symmetric structure, the second laser transmitting and receiving module 200b and the fourth laser transmitting and receiving module 200d have a center-symmetric structure, and the first laser transmitting and receiving module 200d has a center-symmetric structure. The transmitting and receiving module 200a and the second laser transmitting and receiving module 200b have an axisymmetric structure, and the third laser transmitting and receiving module 200c and the fourth laser transmitting and receiving module 200d have an axisymmetric structure.

Here, it can be understood that the above-mentioned first laser transmitting and receiving module 200a and the third laser transmitting and receiving module 200c have a center-symmetric structure, which means that the first laser transmitting and receiving module 200a and the third laser transmitting and receiving module 200c have a centrally symmetric structure. The symmetry of the overall layout direction does not mean that the shapes, positions and directions of various components arranged inside the first laser transmitting and receiving module 200a and the third laser transmitting and receiving module 200c are also symmetrical to each other.

Similarly, the second laser transmitting and receiving module 200b and the fourth laser transmitting and receiving module 200d have a center-symmetric structure, the first laser transmitting and receiving module 200a and the second laser transmitting and receiving module 200b have an axisymmetric structure, and the third laser transmitting and receiving module 200b has an axisymmetric structure. The axisymmetric structure of the laser transmitting and receiving module 200c and the fourth laser transmitting and receiving module 200d also refers to the symmetry of the overall layout direction of the laser transmitting and receiving module 200, and is not intended to represent various components arranged inside the laser transmitting and receiving module. The shapes, positions, and orientations are also symmetrical to each other.

Therefore, it can be understood that the four laser transmitting and receiving modules 200a-200d arranged as above can be detected in the four directions of the laser radar respectively, as shown in FIG. On the rotating rotating base 100, therefore, when the lidar rotates, each laser transmitting and receiving module can achieve scanning and ranging under a 360° field of view, thereby increasing the number of laser transmitting and receiving modules used to detect targets. The number of groups, thereby improving the resolution of the lidar.

In addition, the exemplary embodiment of the present disclosure is preferably provided with 4 laser transmitting and receiving modules. Compared with arranging other numbers of laser transmitting and receiving modules, this arrangement can not only improve the space utilization rate of the lidar, but also simplify the layout. Therefore, the lidar of the present disclosure can not only reduce the volume and improve the resolution, but also have the advantages of being easy to assemble and debug.

Further, as shown in FIG. 1 , the above-mentioned laser transmitting and receiving modules 200a-200d may include: laser transmitting arrays 210a-210d, which include a plurality of laser transmitters 211 arranged in an array, and the laser transmitters 211 are used for transmitting out laser light, the outgoing laser light is reflected by the detection target to generate reflected laser light; and laser detection arrays 220a-220d, which include a plurality of laser detectors 221 arranged in an array, and the laser detectors 221 are used to receive the reflected laser light, wherein, after the plurality of laser light emission Among the plurality of laser transmitters 211 included in the receiving module 200 , at least two laser transmitters 211 have different emission angles.

In an exemplary embodiment, as shown in FIG. 2 , at least two laser emitters 211 of the multiple laser emitters 211 arranged on the same laser emitter array may have different emission angles; Each of the laser transmitters 211 may have different emission angles.

Specifically, as shown in FIG. 2, the above-mentioned laser emission arrays 210a-210d may include a plurality of laser transmitters 211, and the laser transmitters 211 may emit outgoing laser light toward the outside of the lidar, and the outgoing laser light will be reflected when encountering a detection target Reflected laser light is generated, and the reflected laser light can be received by the laser detectors 221 arranged on the laser detection arrays near the laser emission arrays 210a-210d, whereby a single laser detection can be realized.

As further shown in FIG. 2 , each of the four laser emitting arrays 210a-210d includes four laser emitters 211 spaced apart in the vertical direction, so the lidar according to the present exemplary embodiment may have a total of The sixteen laser transmitters 211 have different emission angles.

Further, as shown in FIG. 2 , the above-mentioned four laser emission arrays 210a-210d can be respectively arranged in the first laser emission and reception module 200a, the second laser emission and reception module 200b, the third laser emission and reception module 200c and the In the fourth laser transmitting and receiving module 200d, the sixteen laser transmitters 211 do not have to be arranged in the same vertical direction, so the overall height of the laser radar can be reduced, thereby reducing the volume of the laser radar.

FIG. 3 is a schematic diagram illustrating an equivalent layout of a laser transmitter 211 of a multi-line lidar according to an exemplary embodiment of the present invention.

When the rotating base 100 of the lidar rotates, the sixteen laser transmitters 211 will emit outgoing lasers with different exit angles to the 360° field of view while rotating, and the equivalent layout of the sixteen laser transmitters 211 is the same as The equivalent distribution shape of the outgoing laser is shown in Figure 3. It can be seen that, compared with the traditional laser radar with only one laser transmitting and receiving module, the multi-line laser radar of the present invention can generate 16 pixels on the detection target, so the multi-line laser radar of the present invention can significantly Improve lidar resolution.

Therefore, it can be understood that although the above-mentioned exemplary embodiment describes a lidar including four laser transmitting and receiving modules 200a-200d, four laser transmitting arrays 210a-210d and sixteen laser transmitters 211, this The invention is not intended to limit the number of laser radars. Those skilled in the art can select the number of laser transmitting and receiving modules and laser transmitting arrays as required according to the inventive concept disclosed in the present invention, and can also select the number of laser transmitting arrays included in each laser transmitting array as required. the number of laser emitters.

In another exemplary embodiment, among the plurality of laser transmitters 211 included in the plurality of laser transmitting and receiving modules 200, at least two laser transmitters 211 may have different heights; preferably, they are arranged in the same At least two laser emitters 211 of the plurality of laser emitters 211 on the laser emitting array may have different heights; more preferably, each laser emitter 211 may have different heights.

It can be understood that in the multi-line lidar according to the present exemplary embodiment, since the laser transmitters 211 can be arranged in a vertical direction, and by arranging the laser transmitters 211 in a staggered manner, the number of the laser transmitters 211 can be increased, thereby The resolution of the lidar can be increased without increasing the overall height of the lidar, thus reducing the volume of the lidar.

In an exemplary embodiment, the number of laser detectors 221 may be the same as the number of laser transmitters 211 , and the plurality of laser detectors 221 may have angles and heights corresponding to the plurality of laser transmitters 211 one-to-one, respectively. Specifically, the multiple laser detectors 221 may correspond one-to-one with the outgoing lasers emitted by the multiple laser transmitters 211 , and the reflected laser formed by each outgoing laser encountering the detection target will be received by a corresponding laser detector 221 . This arrangement enables the outgoing laser light emitted by each laser transmitter 211 to be received by a corresponding laser detector, thereby improving the detection accuracy of the lidar.

In an exemplary embodiment, as shown in FIG. 2 , the laser emitting array may further include a emitting plate 212 , and the plurality of laser emitters 211 arranged in the array may be arranged on the emitting plate 212 at intervals along the vertical direction. In addition, the laser detection array may further include a receiving plate 222, and the plurality of laser detectors 221 arranged in the array may be arranged on the receiving plate 222 at intervals along the vertical direction. In this way, a plurality of laser transmitters 211 can be arranged in the vertical direction, thereby increasing the number of laser transmitters 211, thereby improving the detection accuracy of the lidar.

In an exemplary embodiment, as shown in FIG. 2 , the above-mentioned laser emitting array may further include a light source driving device and at least four laser emitters 211 electrically connected to the light source driving device. The above-mentioned laser detection array may further include a signal processing device and at least four laser detectors 221 electrically connected to the signal processing device, and the laser detectors 221 may correspond to the laser emitters respectively.

In an exemplary embodiment, the lidar may further include: a light emission control device, which is connected to the light source driving device for controlling the light emission of the laser transmitter 211 .

FIG. 4 is a schematic diagram illustrating a laser emission array of a multi-line lidar according to another exemplary embodiment of the present invention. Further as shown in FIG. 4 , in this exemplary embodiment, the outgoing laser light may be generated by a pulse transmitter, or may be generated by a laser fiber in the form of a split line and transmitted to the laser transmitter 211 .

FIG. 5 is a schematic diagram illustrating a laser emission array of a multi-line lidar according to yet another exemplary embodiment of the present invention. As further shown in FIG. 5 , in this exemplary embodiment, the outgoing laser light may also be generated by a pulse transmitter, or may be generated by a laser fiber in the form of multiple lines and transmitted to the laser transmitter 211 .

In an exemplary embodiment, as shown in FIG. 1 , the laser transmitting and receiving modules 200a-200d may further include: an optical receiving structure, which includes receiving lenses 230a-230d, and the receiving lenses 230a-230d are used for collecting reflected laser light and The collected reflected laser light is made incident on the corresponding laser detector 221 . Specifically, the above-mentioned receiving lenses 230 a - 230 d can collect the reflected laser light and condense the reflected laser light to the laser detector 221 .

In an exemplary embodiment, as shown in FIG. 1 , the laser transmitting and receiving modules 200a-200d may further include: an optical exit structure, which includes transmitting lenses 240a-240d, and the transmitting lenses 240a-240d are arranged on the receiving lenses 230a-240d. 230d and is used to collect the outgoing laser light emitted by the laser transmitter 211 . In one application scenario, as shown in FIG. 1 , each of the plurality of laser transmitting and receiving modules 200a-200d may include at least four transmitting lenses 240a-240d and at least one receiving lens 230a-230d. The above at least four transmitting lenses 240a-230d The lenses 240a-240d may be disposed at upper right, lower right, upper left and lower left of the receiving lenses 230a-230d, respectively.

6 is a schematic diagram illustrating an optical output structure and an optical reception structure of a multi-line lidar according to an exemplary embodiment of the present invention.

In an exemplary embodiment, as shown in FIG. 6 , the optical outgoing structure may include at least four transmitting lenses 240a-240d, and the optical receiving structure may include at least one receiving lens 230a-230d, wherein the at least four transmitting lenses 240a The -240d can be arranged on one side of the receiving lenses 230a-230d, and correspond to the laser transmitters 211 one-to-one. The outgoing laser light emitted by the laser transmitter 211 can be collimated by the collimating cylinder 213 and then exit through the transmitting lenses 240a-240d. Such an arrangement can reduce the difficulty of debugging the transmitting lenses 240a-240d.

In an exemplary embodiment, the multi-line lidar may further include a motor, a top plate, and a light barrier 300 . Specifically, the above-mentioned motor can be connected with the rotating base 100 of the lidar, so that the rotating base 100 can be rotated under the driving of the motor. Further, the above-mentioned top plate can be arranged above the laser transmitting and receiving module 200 to form a space for accommodating the laser transmitting and receiving module 200 between the top plate and the rotating base 100 . Further, the above-mentioned light blocking plate 300 can be arranged between a plurality of laser emission and reception modules 200 to separate the plurality of laser emission and reception modules 200, and the outgoing laser light path of each laser emission and reception module 200 and The reflected laser light path is isolated from the outgoing laser light paths and the reflected laser light paths of other laser transmitting and receiving modules 200 .

In an exemplary embodiment, the multi-line lidar may further include a control device, which may be connected with a motor to control the rotation of the rotating base 100 through the motor. Specifically, the above-mentioned control device can change the rotational speed of the motor by changing the frequency of the current, and when the frequency of the current applied to the motor is increased, the rotational speed of the motor can be increased; and when the frequency of the current applied to the motor is decreased, The speed of the motor can be reduced.

Therefore, it can be understood that since the rotation speed of the motor can be controlled by the control device, the rotation speed of the rotating base 100 can be obtained through the control device, and the rotation angle of the laser transmitter 211 of the lidar can be calculated according to the rotation speed, for example, it can be The rotational angle through which the laser emitter 211 is turned is calculated using the angular velocity of the motor multiplied by the time.

In an exemplary embodiment, the multi-line lidar according to an exemplary embodiment of the present invention may further include an azimuth detection device configured to determine the azimuth of the target, including: determining a laser beam between the target and the lidar The round-trip time T; determine the first angle α between the laser and the first plane in the predetermined coordinate system; determine the rotation angle β of the laser transmitter 211 with the rotating base 100; The position in the coordinate system, the first angle α and the rotation angle β are used to determine the orientation of the target.

FIG. 7 is a schematic diagram illustrating the measurement of a target detection object by a lidar according to an exemplary embodiment of the present invention.

Specifically, as shown in FIG. 7 , the above-mentioned round-trip time T may refer to the time from when the laser transmitter 211 of the lidar emits the outgoing laser light until the laser detector 221 receives the reflected laser light. As further shown in FIG. 7 , the above-mentioned predetermined coordinate system can be a three-dimensional rectangular coordinate system with the rotation axis of the lidar as the z-axis, and the origin O of the three-dimensional rectangular coordinate system can be selected by those skilled in the art as required. Specifically, when the rotation axis of the lidar is used as the z-axis of the three-dimensional rectangular coordinate system, the position of the xOy plane of the three-dimensional rectangular coordinate system can be set according to the time application scenario.

Exemplarily, in an application scenario, when the lidar is vertically arranged on the roof of the vehicle, the rotation axis of the lidar extends in the vertical direction, so the z-axis of the above-mentioned three-dimensional Cartesian coordinate system is also in the vertical direction. In this way, the xOy plane of the three-dimensional rectangular coordinate system can be selected on the upper surface of the rotating base 100 of the lidar, or can be selected on the road surface on which the vehicle travels, which can be set according to actual needs.

Further, as shown in FIG. 7 , the above-mentioned first angle α may refer to the emission angle of the laser transmitter 211 of the lidar, that is, the outgoing laser emitted by the laser transmitter 211 of the lidar and the xOy plane of the three-dimensional rectangular coordinate system. the angle between. Further, as shown in FIG. 7 , the above-mentioned rotation angle β may refer to the angle that the laser transmitter 211 of the lidar rotates along with the rotating base 100 of the lidar when the laser transmitter 211 of the lidar emits laser light, which is equal to the angle of the laser beam of the lidar. The included angle between the projection of the outgoing laser light emitted by the transmitter 211 on the xOy plane and the x-axis.

In an exemplary embodiment, the round-trip time T may be determined by a timing unit connected to the laser detector 221 . Specifically, the above timing unit can record the time when the laser transmitter 211 of the lidar emits the outgoing laser and the time when the laser detector 221 receives the reflected laser, and calculates the time when the laser detector 221 receives the reflected laser and the laser of the lidar. The difference between the times when the transmitter 211 emits the outgoing laser light, so that the round-trip time T can be obtained.

Further, in an exemplary embodiment, the emission angle of each laser transmitter 211 can be obtained through the configuration of the laser transmitters 211 of the lidar, so as to obtain the first clip between the laser and the first plane in the predetermined coordinate system angle α. It can be understood that, since the emission angle of the laser transmitter 211 can be adjusted as required, the first included angle α between the laser and the first plane in the predetermined coordinate system can also be adjustable or fixed.

Further, in an exemplary embodiment, the rotation angle β of the laser transmitter 211 with the rotating base 100 can be obtained based on the rotation speed of the rotating base of the lidar, for example, the rotation angle β can be calculated using the following formula:

β=w×t

Wherein, w is the angular velocity of the rotating base 100, and t is the running time.

Further, in an exemplary embodiment, the following formula can be used to calculate the three-dimensional coordinates (x, y, z) of each pixel on the detection target in the above-mentioned predetermined coordinate system:

Wherein, h is the distance between the laser transmitter 211 and the xOy plane; lx is the distance between the laser transmitter 211 and the _xOz plane; ly is the distance between the laser transmitter 211 and the _yOz plane; c is the speed of the laser.

Further, in an exemplary embodiment, the three-dimensional coordinates (x, y, z) of each pixel of the lidar in the above-mentioned predetermined coordinate system can be calculated separately, and each pixel can be drawn in the three-dimensional coordinates. , so that the data point cloud of the detection target can be obtained.

It can be understood that in this exemplary embodiment, the pixel points generated by the multiple laser transmitting and receiving modules 200 of the lidar can be calculated in the same predetermined coordinate system, and the detection can be drawn in the same predetermined coordinate system The target's data point cloud. Therefore, compared with the traditional multi-line laser radar model in which each laser emitting light source is used as the center, the laser radar of the present invention can significantly improve the detection accuracy of the laser radar.

FIG. 8 is a flowchart illustrating a data point cloud processing method of a multi-line lidar according to an exemplary embodiment of the present invention.

In the second aspect, as shown in FIG. 8 , an exemplary embodiment of the present invention further provides a data point cloud processing method for a multi-line lidar, which can be used as described in the first aspect and various embodiments thereof. For a multi-line laser radar, the method may include: determining the round-trip time T of the laser light between the target and the laser radar (S100); determining the first angle α between the laser light and a predetermined plane in a predetermined coordinate system (S200); determining the laser light the rotation angle β of the transmitter along with the rotating base (S300); and determine the orientation of the target according to the round-trip time T, the position of the laser transmitter in the predetermined coordinate system, the first included angle α and the rotation angle β (S400) .

The method of this exemplary embodiment is further described below in conjunction with the three-dimensional coordinate system shown in FIG. 7 and FIG. 8 .

Specifically, the above-mentioned round-trip time T may refer to the time from when the laser transmitter of the multi-line laser radar emits the outgoing laser light until the laser detector receives the reflected laser light. As further shown in FIG. 7 , the above-mentioned predetermined coordinate system can be a three-dimensional rectangular coordinate system with the rotation axis of the lidar as the z-axis, and the origin O of the three-dimensional rectangular coordinate system can be selected by those skilled in the art as required. Specifically, when the rotation axis of the multi-line lidar is used as the z-axis of the three-dimensional rectangular coordinate system, the position of the xOy plane of the three-dimensional rectangular coordinate system can be set according to the time application scenario.

Exemplarily, in an application scenario, when the multi-line lidar is vertically arranged on the roof of the vehicle, the rotation axis of the multi-line lidar extends in the vertical direction, so the z-axis of the above three-dimensional Cartesian coordinate system is also Extend in the vertical direction, so that the xOy plane of the three-dimensional rectangular coordinate system can be selected on the upper surface of the rotating base of the lidar, or can be selected on the road surface that the vehicle travels, which can be set according to actual needs.

Further, as shown in FIG. 7 , the above-mentioned first angle α may refer to: the emission angle of the laser transmitter of the multi-line lidar, that is, the difference between the outgoing laser emitted by the laser transmitter of the multi-line lidar and the three-dimensional rectangular coordinate system. The angle between the xOy planes. Further, as shown in FIG. 7 , the above-mentioned rotation angle β may refer to: when the laser transmitter of the multi-line lidar emits the outgoing laser, the angle that the rotating base of the lidar rotates is equal to the laser beam of the lidar. The angle between the projection of the outgoing laser emitted by the transmitter on the xOy plane and the x-axis.

In a practical application scenario, the round-trip time T can be determined by a timing unit connected to the laser detector. Specifically, the above timing unit can record the time when the laser transmitter of the lidar emits the outgoing laser and the time when the laser detector receives the reflected laser, and calculate the time when the laser detector receives the reflected laser and the laser transmitter of the lidar emits the laser. The difference between the times when the laser light is emitted, so that the round-trip time T can be obtained.

Further, in an exemplary embodiment, the emission angle of each laser transmitter can be obtained through the configuration of the laser transmitters of the lidar, so as to obtain the first included angle α between the laser and the first plane in the predetermined coordinate system . It can be understood that, since the emission angle of the laser transmitter can be adjusted as required, the first included angle α between the laser and the first plane in the predetermined coordinate system can also be adjustable or fixed.

Further, in an exemplary embodiment, the rotation angle β of the laser transmitter along with the rotating base can be obtained based on the rotation speed of the rotating base of the lidar. For example, the rotation angle β can be calculated using the following formula: β= w×t, where w is the angular velocity of the rotating base and t is the running time.

Further, in an exemplary embodiment, the following formula can be used to calculate the three-dimensional coordinates (x, y, z) of each pixel on the detection target in the above-mentioned predetermined coordinate system:

Among them, h is the distance between the laser transmitter and the xOy plane; lx is the distance between the laser transmitter and the _xOz plane; ly is the distance between the laser transmitter and the _yOz plane; c is the speed of the laser.

Further, in an exemplary embodiment, the three-dimensional coordinates (x, y, z) of each pixel of the lidar in the above-mentioned predetermined coordinate system can be calculated separately, and each pixel can be drawn in the three-dimensional coordinates. , so that the data point cloud of the detection target can be obtained.

It can be understood that in this exemplary embodiment, the pixel points generated by the multiple laser transmitting and receiving modules of the lidar can be calculated in the same predetermined coordinate system, and the detection target can be drawn in the same predetermined coordinate system data point cloud. Therefore, compared with the traditional multi-line laser radar model in which each laser emitting light source is used as the center, the laser radar of the present invention can significantly improve the detection accuracy of the laser radar.

In an exemplary embodiment, the round-trip time may be the time difference between when the laser transmitter emits the outgoing laser light and the laser detector receives the reflected laser light from the detection target.

With reference to the various exemplary embodiments described above, those skilled in the art can understand that the present invention has at least the following beneficial effects.

On the one hand, the laser radar according to the exemplary embodiment of the present invention is provided with a plurality of laser transmission and reception modules, and the plurality of laser transmitters included in the plurality of laser transmission and reception modules are arranged to have different emission angles. Detect the number of pixels on the target, which can significantly improve the resolution of lidar. In addition, the multi-line lidar of the exemplary embodiment of the present invention can increase the number of laser transmitters by arranging a plurality of laser transmitters to have different heights, so that the overall height of the lidar can be improved without increasing the overall height of the lidar. The resolution of lidar can reduce the volume of lidar.

On the other hand, the multi-line laser radar and its data point cloud processing method of the present invention establish a three-dimensional Cartesian coordinate system with the rotation axis of the laser radar as the z-axis, so that the multi-line laser radar can be calculated under the same predetermined coordinate system. The pixel points generated by each laser transmitting and receiving module can draw the data point cloud of the detection target in the same predetermined coordinate system. Therefore, the laser radar and the method for determining the orientation of the target by the laser radar of the present invention can further improve the detection accuracy of the laser radar.

In the above description of this specification, unless otherwise expressly specified and limited, terms such as "fixed", "installed", "connected" or "connected" should be construed in a broad sense. For example, with regard to the term "connection", it may be a fixed connection, a detachable connection, or an integrated; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediate medium , or it can be a communication within two elements or an interaction relationship between two elements. Therefore, unless otherwise clearly defined in this specification, those skilled in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

From the above description of this specification, those skilled in the art can also understand the following terms such as "upper", "lower", "front", "rear", "left", "right", "length", "width" ", "thickness", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", "center", Terms indicating an orientation or a positional relationship such as "longitudinal", "horizontal", "clockwise" or "counterclockwise" are based on the orientation or positional relationship shown in the drawings of this specification, which are only for the convenience of explaining the present invention The purpose of the scheme and simplified description is not to express or imply that the involved devices or elements must have a particular orientation, be constructed and operate in a particular orientation, so the above-mentioned orientation or positional relationship terms should not be understood or construed as Limitations of Invention Schemes.

In addition, the terms "first" or "second" used in this specification to refer to the terms of numbers or ordinal numbers are only for the purpose of description, and should not be construed as expressing or implying relative importance or implicitly indicating the indicated the number of technical characteristics. Thus, a feature defined as "first" or "second" may expressly or implicitly include at least one of that feature. In the description of this specification, "plurality" means at least two, such as two, three or more, etc., unless expressly and specifically defined otherwise.

While this specification has shown and described various embodiments of the present invention, it will be obvious to those skilled in the art that such embodiments have been provided by way of example only. Numerous modifications, changes and substitutions will occur to those skilled in the art without departing from the spirit and spirit of the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. The appended claims are intended to define the scope of the invention, and therefore to cover modular compositions, equivalents, or alternatives within the scope of these claims.

Claims (11)

1. A multi-line laser radar, comprising a rotatable rotating base and a plurality of laser transmitting and receiving modules arranged on the rotating base along the circumferential direction, the laser transmitting and receiving modules comprising: a laser emission array, which includes a plurality of laser emitters arranged in an array, the laser emitters are used to emit outgoing laser light, and the outgoing laser light is reflected by a detection target to generate reflected laser light; and a laser detection array comprising a plurality of laser detectors arranged in an array, the laser detectors being configured to receive reflected laser light, Wherein, among the plurality of laser emitting arrays included in the plurality of laser emitting and receiving modules, the plurality of laser transmitters correspondingly arranged along the circumferential direction have different emission angles respectively. 2 . The multi-line laser radar according to claim 1 , wherein between the plurality of laser emitting arrays included in the plurality of laser emitting and receiving modules, the plurality of laser emitters correspondingly arranged along the circumferential direction are respectively 2 . with different heights. 3 . The multi-line lidar of claim 1 , wherein the number of the laser detectors is the same as the number of the laser emitters, and the plurality of laser detectors respectively have the same number as the plurality of laser emitters. 4 . One-to-one corresponding angle and height. 4. The multi-line lidar of claim 1, wherein all the laser transmitters have different emission angles. 5. The multi-line laser radar according to claim 1, the laser transmitting and receiving module further comprises: an optical receiving structure, comprising a receiving lens for collecting reflected laser light and making the collected reflected laser light incident on a corresponding laser detector; and/or An optical exit structure including a transmitting lens arranged around the receiving lens and used to collect exit laser light emitted by the laser transmitter. 6. The multi-line lidar of claim 5, wherein the optical exit structure comprises at least four transmit lenses, and the optical receive structure comprises at least one receive lens, wherein the at least four transmit lenses are arranged on one side of the receiving lens. 7 . The multi-line laser radar according to claim 1 , wherein the plurality of laser transmitting and receiving modules comprises: a first laser transmitting and receiving module, a second laser transmitting and receiving module, and a third laser transmitting and receiving module. 8 . and the fourth laser transmitting and receiving module, Among them, the first laser transmitting and receiving module and the third laser transmitting and receiving module are in a center-symmetric structure, the second laser transmitting and receiving module and the fourth laser transmitting and receiving module are in a center-symmetric structure, and the first laser transmitting and receiving module is in a center-symmetric structure. The second laser transmitting and receiving module has an axisymmetric structure, and the third laser transmitting and receiving module and the fourth laser transmitting and receiving module have an axisymmetric structure. 8. The multi-line lidar of claim 1, wherein, The laser emitting array further includes a emitting plate on which a plurality of laser emitters arranged in an array are arranged, and The laser detection array further includes a receiving plate, and a plurality of laser detectors arranged in the array are arranged on the receiving plate. 9. The multi-line lidar of claim 1, wherein, The laser emission array further includes a light source driving device and at least four laser emitters electrically connected to the light source driving device; The laser detection array further includes a signal processing device and at least four laser detectors electrically connected to the signal processing device; and The laser detectors and the laser emitters are in one-to-one correspondence. 10. The multi-line lidar of claim 1, wherein the lidar further comprises a motor, a top plate and a light barrier, The motor is connected with the rotating base, so that the rotating base rotates under the driving of the motor; The top plate is arranged above the laser transmitting and receiving module; and The light blocking plate is arranged between the plurality of laser transmitting and receiving modules to separate the plurality of laser transmitting and receiving modules. 11. A data point cloud processing method for the multi-line laser radar according to any one of claims 1-10, the method comprising: determining the round-trip time T of the laser light between the target and the lidar; Determine the first angle α between the laser and the predetermined plane in the predetermined coordinate system; determining the rotation angle β of the laser emitter with the rotating base; and The orientation of the target is determined according to the round-trip time T, the position of the laser transmitter in the predetermined coordinate system, the first included angle α and the rotation angle β.

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