Lidar

Abstract

The application relates to a laser radar and belongs to the technical field of sensors. The laser radar comprises a first rotating seat, a laser transmitter, a laser receiver and a processor. The first rotating seat comprises a first rotating part and a first fixed part, and the first rotating part is installed on the first fixed part. The laser transmitter and the laser receiver are installed on the first rotating part, and the laser transmitter and the laser receiver rotate synchronously with the first rotating part. A first rotating axis of the first rotating part passes through the laser receiver, and a part of the first rotating axis is located in a detection range of the laser receiver. The detection range of the laser radar is circular in projection on a plane perpendicular to the first rotating axis. The first rotating seat, the laser transmitter, the laser receiver and the processor are electrically connected respectively. The laser radar provided by the application can effectively reduce the production cost of the laser radar.

Description

Technical Field

[0001] This application relates to the field of sensor technology, specifically to a lidar. Background Technology

[0002] LiDAR is a sensor capable of accurately detecting the distribution of objects in three-dimensional space. It features strong resistance to active interference, small size, and light weight. Currently, LiDAR is widely used in intelligent transportation, security monitoring, urban planning, agricultural development, water conservancy projects, and environmental monitoring, providing crucial raw data for social development and scientific research, achieving significant economic benefits, and demonstrating promising application prospects.

[0003] A lidar system typically consists of a laser emitter and a laser receiver, and its detection range is primarily influenced by the detection range of the laser receiver. The laser receiver comprises multiple point detectors. A common application of lidar is to continuously detect a specified area within a defined direction. Because the detection range of each point detector is small, a sufficient number of point detectors need to be arranged within the lidar system to meet the required detection range in the specified direction.

[0004] The aforementioned lidar requires a very large number of single-point detectors to achieve detection within a certain range, which greatly increases the number of optoelectronic components used in the entire lidar, resulting in persistently high production costs. Summary of the Invention

[0005] This application provides a lidar that can solve the technical problems existing in related technologies. The technical solution of the lidar is as follows: This application provides a lidar system, which includes a first rotating base, a laser emitter, a laser receiver, and a processor. The first rotating base includes a first rotating component and a first fixed component, with the first rotating component mounted on the first fixed component. The laser emitter and laser receiver are mounted on the first rotating component and rotate synchronously with the first rotating component. A first rotation axis of the first rotating component passes through the laser receiver, and a portion of the first rotation axis lies within the detection range of the laser receiver. The projection of the lidar's detection range onto a plane perpendicular to the first rotation axis is circular. The first rotating base, laser emitter, and laser receiver are electrically connected to the processor.

[0006] In one possible implementation, the laser receiver comprises a plurality of single-point detectors distributed in a planar array, and the laser emitter comprises a plurality of single-point lasers distributed in a planar array.

[0007] In one possible implementation, the laser receiver includes a plurality of point detectors equally spaced along a straight line, and the laser emitter includes a plurality of point lasers equally spaced along a straight line.

[0008] In one possible implementation, the line containing multiple equally spaced point detectors is perpendicular to the first rotation axis.

[0009] In one possible implementation, the first rotation axis of the first rotating member is parallel to the central axis of the detection range of the laser receiver, and the distance between the first rotation axis and the central axis of the detection range of the laser receiver is not equal to n. d / 2, where d is the distance between adjacent single-point detectors and n is a positive integer.

[0010] In one possible implementation, the first rotation axis of the first rotating element is parallel to the central axis of the detection range of the laser receiver and the distance between them is equal to d / 4.

[0011] In one possible implementation, the first rotation axis of the first rotating component coincides with the central axis of the detection range of the laser receiver.

[0012] In one possible implementation, the angle between the first rotation axis of the first rotating member and the detection direction of the laser receiver is equal to half of the detection field of view of the laser receiver.

[0013] In one possible implementation, the aforementioned lidar further includes a second rotating base. The second rotating base includes a second rotating component and a second fixing component, with the second rotating component mounted on the second fixing component. The first fixing component of the first rotating base is fixed to the second rotating component, and the first fixing component rotates with the second rotating component.

[0014] In one possible implementation, the second rotation axis of the second rotating member is perpendicular to the first rotation axis of the first rotating member.

[0015] In one possible implementation, the laser receiver of the lidar is a direction-adjustable laser receiver.

[0016] This application provides a lidar whose processor sends a laser emission command to a laser emitter and receives backlight angle information from a laser receiver. The processor acquires the first rotation angle information of a first rotating component in a first rotating base relative to a reference position when the backlight information is received. Based on the backlight angle information, rotation angle information, emission time point, and backlight time point, the spatial position of the object point corresponding to the backlight information is determined, wherein the emission time point is the time when the laser emission command is sent, and the backlight time point is the time when the backlight angle information is received.

[0017] The technical solutions provided by the embodiments of this application have at least the following beneficial effects: This application provides a lidar, including a first rotating base, a laser emitter, a laser receiver, and a processor. The first rotation axis of a first rotating component of the first rotating base passes through the laser receiver, and a portion of the first rotation axis lies within the detection range of the laser receiver. The lidar rotates 360° around the first rotation axis, expanding the detection range of each point detector from a small area to an annular area formed by one revolution of this small area. The projection of the entire lidar's detection range onto a plane perpendicular to the first rotation axis of the first rotating component is circular, effectively increasing the lidar's detection range. When detecting larger target areas, a smaller number of point detectors is sufficient. Therefore, the number of point detectors within the laser receiver can be effectively controlled, thereby significantly reducing the production cost of the lidar.

[0018] Meanwhile, the lidar can rotate to different angles depending on the target being detected, increasing its flexibility. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of a lidar according to an embodiment of this application; Figure 2 This is a schematic diagram of the structure of a lidar according to an embodiment of this application; Figure 3 This is a schematic diagram of the structure of a lidar according to an embodiment of this application; Figure 4 This is a schematic diagram of the structure of a lidar according to an embodiment of this application; Figure 5 This is a schematic diagram of the structure of a lidar according to an embodiment of this application; Figure 6 This is a schematic diagram illustrating the detection range of a laser receiver according to an embodiment of this application; Figure 7 This is a schematic diagram of the structure of a lidar according to an embodiment of this application; Figure 8 This is a schematic diagram illustrating the detection range of a laser receiver according to an embodiment of this application; Figure 9 This is a schematic diagram of the structure of a lidar according to an embodiment of this application; Figure 10 This is a schematic diagram illustrating the detection range of a laser receiver according to an embodiment of this application; Figure 11 This is a schematic diagram of the structure of a lidar as shown in an embodiment of this application.

[0021] Legend 1. First rotating base; 11. First rotating component; 12. First fixing component; 13. Housing; 14. Bearing; 15. Direct drive motor; 16. Code disk reader; 17. Rotating code disk; 2. Laser emitter; 21. Single-point laser; 22. First optical component; 23. First bracket; 24. Third optical component; 25. Reflector; 26. Third bracket; 3. Laser receiver; 31. Single-point detector; 32. Second optical component; 33. Second bracket; 34. Fourth optical component; 4. Processor; 5. Second rotating base; 51. Second rotating component; 52. Second fixing component. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0023] This application provides a lidar, the corresponding structure of which is as follows: Figure 1 As shown, the lidar includes a first rotating base 1, a laser emitter 2, a laser receiver 3, and a processor 4. The first rotating base 1 includes a first rotating component 11 and a first fixing component 12, with the first rotating component 11 mounted on the first fixing component 12. The laser emitter 2 and laser receiver 3 are mounted on the first rotating component 11 and rotate synchronously with it. The first rotation axis of the first rotating component 11 passes through the laser receiver 3, and a portion of the first rotation axis lies within the detection range of the laser receiver 3. The projection of the lidar's detection range onto a plane perpendicular to the first rotation axis is circular. The first rotating base 1, laser emitter 2, and laser receiver 3 are electrically connected to the processor 4.

[0024] The first rotating base 1 may further include a first motor and a first angle sensor. The first motor drives the first rotating component 11 to rotate, and the first angle sensor measures the rotation angle of the first rotating component 11. The first motor can be directly fixed to the first fixing component 12 by welding, snap-fitting, or other methods. The first rotating component 11 can be mounted on the first shaft of the first motor. The first angle sensor can be mounted on the first rotating component 11. The first angle sensor can be a rotary code disk, which can be an absolute encoder, such as a contact encoder or an optical encoder, or an incremental encoder.

[0025] Among them, the single-point laser 21 of the laser emitter 2 is used to emit a laser beam, and can be either an edge emitter or a vertical cavity surface emitter.

[0026] In this design, the single-point detector 31 of the laser receiver 3 is used to receive the echo light signal and convert it into a laser trigger electrical signal. The photosensitive element in the single-point detector 31 used to convert the echo light signal into a laser trigger electrical signal can be a photodiode, such as an avalanche photodiode, a P-type semiconductor-dosage-N-type semiconductor photodiode, etc., or an integrated detector chip, such as a charge-coupled device image sensor, a complementary metal oxide semiconductor, an array avalanche photodiode, an array single-photon avalanche photodiode, etc.

[0027] The laser emitter 2 and laser receiver 3 are mounted on the first rotating component 11 of the first rotating base 1. The laser emitter 2 and laser receiver 3 can be directly connected to the first rotating component 11 by welding, threaded connection, snap-fit, or other methods, or they can be indirectly connected through an intermediate component, such as a connecting rod or a double-ended bolt. The connection methods between the laser emitter 2, laser receiver 3, and the first rotating component 11 can be the same or different. For example, the laser emitter 2 and laser receiver 3 can be directly connected to the first rotating component 11 by welding, or the laser emitter 2 can be directly connected to the first rotating component 11 by welding, while the laser receiver 3 can be indirectly connected to the first rotating component 11 through a double-ended bolt.

[0028] The processor 4 can be a general-purpose logic controller, such as a microcontroller, a digital signal processing controller, or a field-programmable gate array controller. Alternatively, the processor 4 can be a computing control system, such as a pre-embedded computing control system composed of application-specific integrated circuit devices and memory.

[0029] In this embodiment, the lidar may further include a housing 13, a bearing 14, a direct-drive motor 15, a code disk reader 16, and a rotating code disk 17. The housing 13 supports the first rotating base 1, the laser emitter 2, and the laser receiver 3. The bearing 14 supports the laser emitter 2 and the laser receiver 3 and ensures their rotational movement relative to the housing 13. The direct-drive motor 15 drives the synchronous rotation of the laser emitter 2 and the laser receiver 3. The code disk reader 16 and the rotating code disk 17 work together to detect the angle rotated by the first rotating component 11. The laser receiver 3 and the laser emitter 2 can be separate or integrated. Two possible structures are given below: Structure 1 One possible structure for the laser receiver 3 and the laser emitter 2 is as follows: Figure 2As shown, the laser emitter 2 and the laser receiver 3 are separate. The laser emitter 2 may include multiple point lasers 21, a first optical device 22, and a first support 23. The multiple point lasers 21 and the first optical device 22 are respectively mounted on the first support 23. The multiple point lasers 21 may be arranged on different straight lines or on the same straight line. The laser receiver 3 may include multiple point detectors 31, a second optical device 32, and a second support 33. The multiple point detectors 31 and the second optical device 32 are respectively mounted on the second support 33. The multiple point detectors 31 may be distributed on different straight lines or on the same straight line. The arrangement of the multiple point lasers 21 and the arrangement of the multiple point detectors 31 may be the same or different. For example, the multiple point lasers 21 and the multiple point detectors 31 may be arranged on the same straight line, or the multiple point lasers 21 may be arranged on the same straight line, and the multiple point detectors 31 may be arranged in the same plane.

[0030] The first rotating base 1 of the lidar is fixedly mounted on the housing 13. One end of the bearing 14 is fixedly mounted on the housing 13, and the other end is fixedly connected to the first bracket 23 and the second bracket 33 respectively. One end of the direct drive motor 15 is fixedly mounted on the housing 13, and the other end is fixedly connected to the first bracket 23 and the second bracket 33 respectively. The code disk reader 16 is fixedly mounted on the housing 13, and the rotating code disk 17 is mounted on the first bracket 23 and the second bracket 33.

[0031] Structure 2 One possible structure for the laser receiver 3 and the laser emitter 2 is as follows: Figure 3 As shown, the laser emitter 2 and laser receiver 3 are integrated and jointly mounted on the third bracket 26. The laser emitter 2 may include multiple point lasers 21, a third optical device 24, and a reflector 25. These point lasers 21, optics 24, and reflector 25 are respectively mounted on the third bracket 26. The point lasers 31 can be arranged on different straight lines or on the same straight line. The laser receiver 3 includes multiple point detectors 31 and a fourth optical device 34. These detectors 31 and optics 34 are respectively mounted on the third bracket 26. The point detectors 31 can be arranged on different straight lines or on the same straight line. The arrangement of the point lasers 21 and the point detectors 31 can be the same or different. For example, the point lasers 21 and detectors 31 can be arranged on the same straight line, or the point lasers 21 can be arranged on the same straight line, and the detectors 31 can be arranged in the same plane.

[0032] The first rotating base 1 and the first fixing component 11 of the lidar are fixedly mounted on the housing 13. One end of the bearing 14 is fixedly mounted on the housing 13, and the other end is fixedly connected to the third bracket 26. One end of the direct drive motor 15 is fixedly mounted on the housing 13, and the other end is fixedly connected to the third bracket 26. The code disk reader 16 is fixedly mounted on the housing 13, and the rotating code disk 17 is mounted on the third bracket 26.

[0033] In both of the above structures, the first optical device 22 and the third optical device 24 can be used to shape the laser beam, that is, to make the cross-section of the laser beam generated by the single-point laser 21 at the time of emission a preset shape, such as a straight line or a rectangle. The first optical device 22 and the fourth optical device 34 can be used to increase the diffusion angle of the laser beam, thereby expanding the detection range of the laser emitter 2. The second optical device 32 and the fourth optical device 34 are used to filter the echo light of non-signal wavelengths and focus the filtered echo light onto the multiple single-point detectors 31 of the laser receiver 3. The filtering effect of the second optical device 32 and the fourth optical device 34 can be achieved by spraying a filter coating on their surface or by setting a filter. The first optical device 22, the second optical device 32, the third optical device 24, and the fourth optical device 34 can be a single aspherical lens or a lens group composed of multiple aspherical lenses.

[0034] The single-point lasers 21 of the laser emitter 2 and the single-point detectors 31 of the laser receiver 3 can be arranged at equal intervals. For example, the single-point lasers 21 or single-point detectors 31 can be arranged at equal intervals on the same straight line, on the same circumference, or arrayed in the same plane. Alternatively, the single-point lasers 21 of the laser emitter 2 and the single-point detectors 31 of the laser receiver 3 can be arranged at non-equal intervals. For example, the single-point lasers 21 or single-point detectors 31 can be arranged at non-equal intervals on the same straight line, or on the same circumference. The arrangement of the single-point lasers 21 of the laser emitter 2 and the arrangement of the single-point detectors 31 of the laser receiver 3 can be the same or different. For example, multiple single-point lasers 21 and multiple single-point detectors 31 can be arranged at equal intervals on the same straight line, or multiple single-point lasers 21 can be arranged at equal intervals on the same straight line, while multiple single-point detectors 31 can be arranged at non-equal intervals on the same circumference.

[0035] The first bracket 23, the second bracket 33, and the third bracket 26 can be cylindrical components with one open end. The bottom surface of the cylindrical component is used to mount the single-point laser 11 or the single-point detector 31, and the open end of the cylindrical component is used to mount the first optical device 22, the second optical device 32, or the fourth optical device 34. The bottom surface of the cylindrical component can be any shape, such as circular or rectangular, and the opening shape of its open end can be any shape, such as circular or square. The shape of the bottom surface and the shape of the opening of the cylindrical component can be the same or different.

[0036] In this embodiment, the first rotation axis of the first rotating component 11 of the lidar passes through the laser receiver 3, and a portion of the first rotation axis lies within the detection range of the laser receiver 3. By adjusting the positional relationship between the first rotation axis of the first rotating component 11 and the central axis of the detection range of the laser receiver 3, lidars with different detection effects can be obtained, such as high resolution, high frame rate, and large field of view. Several possible structures are given below: Structure 1 The first rotation axis of the first rotating member 11 is parallel to the central axis of the detection range of the laser receiver 3. When the first rotation axis of the first rotating member 11 is parallel to the central axis of the detection range of the laser receiver 3, the laser receiver 3 rotates 360° around the first rotation axis, and the resulting circular detection field of view has a high resolution effect.

[0037] The single-point detectors 31 can be distributed along a straight line, and the corresponding structure can be as follows: multiple single-point detectors 31 on the laser receiver 3 of the lidar are equally spaced along the same straight line, and this straight line is perpendicular to the first rotation axis of the first rotating component 11 of the first rotating seat 1, and the corresponding structure is as follows. Figure 4 The first rotation axis is parallel to the central axis of the detection range of the laser receiver 3, and the distance between the first rotation axis and the central axis of the detection range of the laser receiver 3 is not equal to n. d / 2, where d is the distance between adjacent single-point detectors 31, and n is a positive integer.

[0038] One possible implementation, such as Figure 5 As shown, the first rotation axis is parallel to the central axis of the detection range of the laser receiver 3, and there is a distance of d / 4, where d is the spacing between adjacent single-point detectors 31. Figure 6The detection range shown is such that when the laser receiver 3 of the lidar rotates 360° around the first rotation axis of the first rotating member 11, a complete circular field of view composed of multiple concentric rings can be formed. In this complete circular field of view, the number of concentric rings is equal to the number of single-point detectors 31 of the laser receiver 3. Each concentric ring corresponds to one single-point detector 31, and each concentric ring represents the detection trajectory of the corresponding single-point detector 31. For example, when the laser receiver 3 includes 10 single-point detectors 31, the circular field of view includes 10 concentric rings. However, if the first rotation axis is aligned with the central axis of the detection range of the laser receiver 3, and the laser receiver 3 rotates 360° around the first rotation axis, a circular field of view of similar size but composed of only 5 concentric rings can be formed. Therefore, it can be seen that when the first rotation axis is parallel to the central axis of the detection range of the laser receiver 3 and there is a distance of d / 4, compared to when the first rotation axis is aligned with the central axis of the detection range of the laser receiver 3, the change in detection range is very small, and the number of concentric rings is doubled. Therefore, the resolution of the lidar is also doubled.

[0039] In one possible implementation, the central axis of the detection range of the laser receiver 3 may also have a distance between it and the first rotation axis that is not equal to d / 4 and not equal to n. Any spacing of d / 2, for example, d / 8, d / 3, 5 When the laser receiver 3 rotates 360° around the first rotation axis, it can also form a circular detection field of view with a high-resolution detection area, where d is the distance between adjacent single-point detectors 31 and n is a positive integer. However, when the distance between the central axis of the detection range of the laser receiver 3 and the first rotation axis is d / 4, the detection range of the high-resolution detection area formed by the laser receiver 3 is larger, and the detection trajectory distribution of each single-point detector 31 on the laser receiver 3 is more uniform.

[0040] The single-point detectors can be distributed in a rectangle, and the corresponding structure can be as follows: multiple single-point detectors 31 on the laser receiver 3 of the lidar are distributed in the same rectangular plane, and the central axis of the detection range of the laser receiver 3 passes through the center point of the rectangular plane and is perpendicular to the rectangular plane.

[0041] In one possible implementation, the single-point detectors 31 are evenly distributed within the same rectangular plane, meaning the distance between a single-point detector 31 and its adjacent single-point detectors 31 in the same row and column is equal. When the first rotation axis of the first rotating member 11 is parallel to the central axis of the detection range of the laser receiver 3, and there exists a value not equal to n... When the spacing is d / 2, the laser receiver 3 rotates 360° around the first rotation axis to form a complete circular detection field of view with a high-resolution detection area, where d is the spacing between adjacent single-point detectors 31 and n is a positive integer.

[0042] In one possible implementation, the point detectors 31 are distributed non-equidistantly within the same rectangular plane. The first rotation axis is parallel to the central axis of the detection range of the laser receiver 3, and the distance from each point detector 31 to the first rotation axis within the rectangular plane is unequal. Similarly, rotating the laser receiver 3 360° around the first rotation axis can form a complete circular detection field of view with a high-resolution detection area.

[0043] Structure 2 The first rotation axis of the first rotating component 11 coincides with the central axis of the detection range of the laser receiver 3. When the first rotation axis of the first rotating component 11 coincides with the central axis of the detection range of the laser receiver 3, the laser receiver 3 rotates 360° around the first rotation axis, forming a complete circular detection field of view with a high frame rate effect.

[0044] One possible implementation, such as Figure 7 As shown, multiple point detectors 31 on the laser receiver 3 of the lidar can be evenly distributed on the same straight line, which is perpendicular to the first rotation axis of the first rotating component 11 of the first rotating base 1. The laser receiver 3 includes multiple pairs of point detectors 31 symmetrical about the first rotation axis. The laser receiver 3 rotates 180° around the first rotation axis, and two point detectors 31 symmetrical about the first rotation axis respectively form corresponding semi-circular detection fields of view. These two semi-circular detection fields of view can constitute a complete circular detection field of view. Thus, the lidar can form a complete circular detection field of view composed of multiple concentric rings, and the detection effect is as follows. Figure 8 As shown. When the number of point detectors 31 is even, a complete circular detection field of view can be formed, consisting of m / 2 concentric annular fields of view, where m is the number of point detectors 31. For example, when there are 10 point detectors 31, the circular detection field of view consists of 5 concentric annular fields of view. When the number of point detectors 31 is odd, a complete circular detection field of view can be formed, consisting of one central circular field of view and m / 2 annular fields of view concentric with the central circular field of view, where m is the number of point detectors 31. For example, when there are 11 point detectors 31, the circular detection field of view consists of one central circular field of view and 5 annular fields of view concentric with the central circular field of view. The laser receiver 3 rotates 360° around the first rotation axis. Two point detectors 31 symmetrical about the first rotation axis form corresponding annular detection fields of view. These two annular detection fields of view overlap. By performing two detections on the annular region, two frames of detection data of the complete annular detection field of view can be obtained. Therefore, the laser receiver 3 rotates 360° around the first rotation axis, and the lidar can acquire two frames of detection data consisting of a complete circular detection field of view composed of multiple concentric rings.

[0045] In one possible implementation, multiple point detectors 31 on the laser receiver 3 of the lidar are distributed within the same rectangular plane, with equal spacing between adjacent point detectors 31. The central axis of the detection range of the laser receiver 3 passes through the center point of the rectangular plane and is perpendicular to the rectangular plane, and the central axis of the detection range of the laser receiver 3 coincides with the first rotation axis. Within the rectangular plane, at least one pair of point detectors 31 are equidistant from the first rotation axis, and each pair of point detectors 31 is symmetrical about the first rotation axis. As described above, when the laser receiver 3 rotates 180° around the first rotation axis, each pair of point detectors 31 symmetrical about the first rotation axis can form a complete circular detection field of view. When the laser receiver 3 rotates 360° around the first rotation axis, each pair of point detectors 31 can form a complete circular detection field of view, and each pair of point detectors 31 can acquire two frames of detection data for the complete circular detection field of view. Therefore, when the laser receiver 3 rotates 360° around the first rotation axis, the lidar can acquire at least two frames of detection data for the complete circular detection field of view.

[0046] Structure 3 There is an angle between the first rotation axis of the first rotating component 11 and the detection direction of the laser receiver 3, where the detection direction can be considered as the central axis of the detection range. When the first rotation axis of the first rotating component 11 and the central axis of the detection range of the laser receiver 3 form a certain angle, that is, the angle between the first rotation axis and the central axis is greater than 0°, the laser receiver 3 rotates 360° around the first rotation axis, and the resulting complete circular detection field of view can obtain a larger detection field of view angle, thereby expanding the detection range. When the aforementioned angle is equal to half of the detection field of view angle of the laser receiver 3, the laser receiver 3 rotates 360° around the first rotation axis, and the resulting detection field of view angle is the largest, which is twice the detection field of view angle of the laser receiver 3 before rotation.

[0047] The corresponding structure could be: the first rotation axis coincides with the boundary of the detection range of the laser receiver 3.

[0048] One possible implementation, such as Figure 9As shown, the laser emitter 2 and laser receiver 3 of the lidar are tilted and mounted on the first rotating component 11, thereby adjusting the detection direction of the detection range. Multiple point detectors 31 on the laser receiver 3 are distributed on the same straight line, which is perpendicular to the central axis of the detection range of the laser receiver 3 but not perpendicular to the first rotation axis. The detection field of view of the laser receiver 3 does not shift, and the central axis of the detection range passes through the midpoint of the line segment formed by the multiple point detectors 31. When the first rotation axis coincides with one boundary of the detection range of the laser receiver 3, the angle between the first rotation axis and the other boundary is equal to the field of view of the detection range of the laser receiver 3, and the angle between the first rotation axis and the central axis is equal to half of the detection field of view of the detection range of the laser receiver 3. The laser receiver 3 rotates 360° around the first rotation axis, and each point detector 31 forms a complete circular detection field of view. The complete circular detection field of view corresponding to each point detector 31 is concentric, and the first rotation axis passes through this center. At this point, the annular detection field of view formed by the boundary of the laser receiver 3 that does not coincide with the first rotation axis is the largest, and the field angle of the annular detection field of view formed by this boundary is twice the field angle of the detection range when the laser receiver 3 is not rotated. The detection effect is as follows: Figure 10 As shown.

[0049] Taking a detection field of view of 40° for the laser receiver 3 as an example, when the first rotation axis coincides with the lower boundary of the laser receiver 3's detection range, the angle between the first rotation axis and the laser center axis is 20°, and the angle with the upper boundary is 40°. Rotating the laser receiver 3 360° around the first rotation axis forms a complete circular detection field of view composed of multiple concentric rings with a detection field of view of 80°. The first rotation axis passes through the center of this circular detection field of view. Therefore, when the first rotation axis coincides with the boundary of the laser receiver 3's detection range, rotating the laser receiver 3 360° around the first rotation axis increases the field of view of the laser receiver 3's detection range, thus expanding the detection range of the laser receiver 3.

[0050] In one possible implementation, the detection direction of the detection range of the laser receiver 3 of the lidar is achieved by adjusting the positional relationship between the single-point detector 31 and the optical device. Multiple single-point detectors 31 on the laser receiver 3 can be distributed on the same straight line, which is not perpendicular to the central axis of the detection range of the laser receiver 3, but perpendicular to the first rotation axis. One boundary of the detection range of the laser receiver 3 is perpendicular to the straight line containing the multiple single-point detectors 31, and the first rotation axis coincides with this boundary. In this case, the angle between the first rotation axis and the other boundary of the detection range is equal to the field of view angle of the detection range of the laser receiver 3, and the angle between the first rotation axis and the central axis of the detection range is equal to half of the field of view angle of the detection range of the laser receiver 3. Similarly, when the laser receiver 3 rotates 360° around the first rotation axis, a complete circular detection field of view is formed, consisting of multiple concentric circular detection fields of view, and the field of view angle of this complete circular detection field of view is twice the field of view angle of the detection range when the laser receiver 3 is not rotated. For example, the detection field of view of the laser receiver 3 is 40°, and the laser receiver 3 rotates 360° around the first rotation axis, forming a complete circular detection field of view with a field of view of 80°.

[0051] The corresponding structure can also be such that the first rotation axis does not coincide with the boundary of the detection range of the laser receiver 3.

[0052] Multiple point detectors 31 on the laser receiver 3 of the lidar can be distributed on the same straight line. The first rotation axis can coincide with any detection ray within the detection range of the laser receiver 3 that is neither a boundary nor a central axis. In this case, the first rotation axis and the central axis of the detection range of the laser receiver 3 form an angle, which can be any value greater than 0° and less than half of the field of view of the detection range of the laser receiver 3. Taking a field of view of 40° for the detection range of the laser receiver 3 as an example, the angle between the first rotation axis and the central axis of the detection range of the laser receiver 3 can be any value greater than 0° and less than 20°, such as 5°, 10°, or 15°. Similarly, rotating the laser receiver 3 360° around the first rotation axis can form a complete circular detection field of view with a large field of view, and the increased field of view is twice the angle between the first rotation axis and the central axis of the detection range of the laser receiver 3. For example, taking a detection range field of view of 40° as an example, when the angle between the first rotation axis and the central axis of the detection range of the laser receiver 3 is 5°, 10° or 15°, the laser receiver 3 can form a complete circular detection field of view with a field of view of 50°, 60° or 70° respectively.

[0053] In this embodiment, the lidar further includes a second rotating base 5, which includes a second rotating component 51 and a second fixing component 52. The second rotating component 51 is electrically connected to the processor 4. The processor 4 can be mounted on either the first rotating base 1 or the second rotating base 5. The second rotating component 51 and the first fixing component 12 of the first rotating base 1 can be integral, i.e., the same component. Alternatively, the second rotating component 51 and the first fixing component 12 of the first rotating base 1 can be two separate components, with the first fixing component 12 fixedly mounted on the second rotating component 51 and rotating with it. The first fixing component 12 and the second rotating component 51 can be directly connected by welding, snap-fitting, bolting, etc., or indirectly connected by an intermediate component, such as a double-ended bolt. The first rotation axis of the first rotating component 11 and the second rotation axis of the second rotating component 51 of the lidar can have an angle of any value. For example, the first rotation axis of the first rotating component 11 is perpendicular to the second rotation axis of the second rotating component 51, with the corresponding structure as shown below. Figure 11 As shown, this lidar can rotate around the first rotation axis to complete the detection of a circular field of view in the vertical direction, and it can also rotate around the second rotation axis to complete the detection of 360° in the horizontal direction.

[0054] The second rotating base 5 may further include a second motor and a second angle sensor. The second motor drives the second rotating component 51 to rotate, and the second angle sensor measures the rotation angle of the second rotating component 51. The second motor can be directly fixed to the second fixing component 52 by welding, snap-fitting, or other methods. The second rotating component 51 can be mounted on the second shaft of the second motor. The second angle sensor can be mounted on the second rotating component 51. The second angle sensor can be a rotary code disk, which can be an absolute encoder, such as a contact encoder or an optical encoder, or an incremental encoder.

[0055] In this embodiment of the application, the detection range of the laser receiver 3 of the aforementioned lidar is adjustable.

[0056] One possible implementation is to adjust the detection range of the laser receiver 3 by adjusting the relative position between the laser receiver 3 and the first rotating member 11, as shown in the diagram. Figure 9As shown, the laser receiver 3 has multiple point detectors 31 distributed on the same straight line. The central axis of its detection range passes through the midpoint of the multiple point detectors 31 and the center point of the second optical device. The two boundaries of the detection range are symmetrical about the central axis. Adjusting the relative position between the laser receiver 3 and the first rotating member 11, that is, adjusting the relative position between the central axis of the detection range of the laser receiver 3 and the first rotation axis of the first rotating member 11, so that there is an angle between the central axis and the first rotation axis, thereby achieving the adjustment of the detection range of the laser receiver 3.

[0057] One possible implementation involves adjusting the relative position between the single-point detector 31 in the laser receiver 3 and the optical device to achieve a bias in the detection range, i.e., adjustment of the detection range. For example, multiple single-point detectors 31 of the laser receiver 3 are distributed on the same straight line. By moving the multiple single-point detectors 31 as a whole upward or downward, the lower or upper boundary of the detection range of the multiple laser receivers 3 passes through the center point of the optical device on the laser receiver 3. At this time, the detection range of the laser receiver 3 is maximally biased. The upward or downward movement of the single-point detector 31 can be achieved by setting a slider inside the laser receiver 3 and mounting the single-point detector 31 on the slider.

[0058] In this embodiment, the processor 4 of the lidar can be used to control the working state of the lidar and process the corresponding detection data to obtain point cloud data. The processor 4 implements rotation control of the first rotating component 11, emission control of the laser emitter 2, and reception control of the laser receiver 3. The processor 4 obtains the emission time point when the laser emitter 2 emits laser light, receives the return angle information sent by the laser receiver 3, and obtains the first rotation angle information of the first rotating component 11 in the first rotating seat 1 relative to the first reference position when the return angle information is received. Based on the return angle information, the first rotation angle information, the emission time point, and the return time point, the processor 4 determines the spatial position of the object point corresponding to the return angle information.

[0059] The backlight angle information indicates the angle between the echo beam and the first rotation axis. This backlight angle information can be the identification information of the single-point detector 31 that receives the echo beam. This identification information is pre-stored in the processor 4, containing a unique corresponding angle between the echo beam and the first rotation axis. The first rotation angle information is the angle information of the first rotating component 11 relative to the first reference position. This first rotation angle information can be an angle value, which can be sent to the processor in real time by the first angle sensor. The emission time point is the time when the processor 4 sends a laser emission command to the laser emitter 2. The backlight time point is the time when the processor 4 receives the backlight angle information sent by the laser receiver 3.

[0060] Next, we will explain the process by which processor 4 determines the spatial location of the object point using a specific scenario: In laser receiver 3, the single-point detectors 31 are distributed along a straight line. The outer surface of laser receiver 3 is marked with installation positioning marks to indicate the position of the single-point detectors 31 along the straight line. The outer surface of the first rotating component 11 and the outer surface of the first fixing component 12 are also marked with installation positioning marks. These installation positioning marks can be either points or lines; the following explanation uses points as an example. The purpose of these three installation positioning marks is to serve as reference marks during installation.

[0061] The installation process of the internal components of the lidar is as follows: The first rotating component 11 is mounted on the first fixed component 12, with the mounting positioning mark of the first rotating component 11 corresponding to the mounting positioning mark of the first fixed component 12. The laser receiver 3 is mounted on the first rotating component 11, with the mounting positioning mark of the laser receiver 3 corresponding to the mounting positioning mark of the first rotating component 11. When installing the first angle sensor, the angle value output by the first angle sensor is guaranteed to be 0° when the mounting positioning marks of the first fixed component 12, the first rotating component 11, and the laser receiver 3 are in the corresponding positions. Based on the above installation process of the internal components of the lidar, when the positions of the mounting positioning marks correspond, the first rotating component 11 of the lidar is located at the first reference position, and the angle value output by the first angle sensor is 0°.

[0062] Based on the first reference position, the spatial coordinate system of the lidar can be defined as follows: the first rotation axis of the first rotating component 11 is defined as the X-axis; the straight line passing through the marked point of the first fixed component 12 and intersecting the first rotation axis perpendicularly is defined as the Z-axis; and the straight line intersecting both the X-axis and Z-axis perpendicularly is defined as the Y-axis. The positive directions of the X-axis, Y-axis, and Z-axis can be set according to actual detection needs. Lidar typically detects targets at relatively long distances; therefore, the lidar can be approximated as a point, which is the origin of the coordinate system. Any point within the lidar (e.g., each single-point detector 31) can be considered located at the origin.

[0063] After processor 4 acquires the backlight angle information, the first rotation angle information, the emission time point, and the backlight time point, the specific calculation steps are as follows: 101. Determine the angle between the echo ray and the first rotation axis based on the backlight angle information, that is, the angle between the line connecting the origin of the coordinate system and the object point and the X-axis.

[0064] 102. Based on the emission time and the return time, determine the propagation time of the laser beam from emission to reception. Using the propagation time and the propagation speed of the laser beam, calculate the distance between the object point and the single-point detector 31 that receives the echo beam, i.e., the distance between the coordinate origin and the object point.

[0065] 103. Based on the distance between the origin and the object point, and the angle between the line connecting the origin and the object point and the X-axis, the distance from the object point to the X-axis can be determined. The distance between the object point's projection point A on the X-axis and the origin can also be determined. The distance between projection point A and the origin is the X-axis coordinate of the object point, denoted as X1.

[0066] 104. Based on the first rotation angle information, determine the angle value through which the first rotating component 11 rotates relative to the first reference position, and denot it as α.

[0067] 105. Draw a straight line L parallel to the Z-axis through the projection point A. It can be seen that the straight line L and the object point are in the same plane, and the angle between the line connecting the object point and the projection point A and the straight line L is equal to α.

[0068] 106. Based on the distance from the object point to the X-axis and the angle between the line connecting the object point and the projection point A and the line L, the distance from the object point to the line L, and the distance between the projection point B and the projection point A on the line L, can be determined. The distance from the object point to the line L is the Y-axis coordinate of the object point, denoted as Y1, and the distance between the projection point B and the projection point A is the Z-axis coordinate of the object point, denoted as Z1.

[0069] 107. Obtain the spatial coordinates of the object point in the spatial coordinate system based on X1, Y1, and Z1, and denot them as (X1, Y1, Z1), thus determining the spatial position of the object point.

[0070] In the case where the lidar includes a second rotating base 5, the processor 4 can acquire the second rotation angle information of the second rotating component 51 in the second rotating base 5 relative to the second reference position when the backlight angle information is received. Based on the backlight angle information, the first rotation angle information, the emission time point, the backlight time point, and the second rotation angle information, the spatial position of the object point corresponding to the backlight angle information is determined.

[0071] The aforementioned lidar may further include a second rotating base 5, with installation positioning marks marked on the outer surface of the second rotating component 51 and the outer surface of the second fixing component 52. These installation positioning marks can be either points or lines; the following explanation uses points as an example. The purpose of these multiple installation positioning marks is to serve as reference markers during installation.

[0072] During installation, the first fixing component 12 of the aforementioned lidar can be mounted on the second rotating component 51 of the second rotating base 5, with the first rotation axis of the first rotating component 11 perpendicularly intersecting the second rotation axis of the second rotating component 51. The second rotating component 51 is then mounted on the second fixing component 52, ensuring that the mounting positioning mark of the second rotating component 51 corresponds to the mounting positioning mark of the second fixing component 52. When installing the second angle sensor, the angle value output by the second angle sensor is guaranteed to be 0° when the mounting positioning marks of the second fixing component 52, the second rotating component 51, and the laser receiver 3 are in a corresponding position. Based on the aforementioned lidar installation process, when the positions of the mounting positioning marks correspond, the second rotating component 51 of the lidar is located at the second reference position, and the angle values ​​output by the first and second angle sensors are 0°.

[0073] Based on the second reference position, the spatial coordinate system of the lidar can be defined as follows: the first rotation axis of the first rotating component 11 is defined as the X-axis, the second rotation axis of the second rotating component 51 is defined as the Z-axis, and the straight line that intersects both the X-axis and Z-axis perpendicularly is defined as the Y-axis. The positive directions of the X-axis, Y-axis, and Z-axis can be set according to actual detection needs. Similarly, the lidar can be approximated as a point, which is the origin of the coordinate system.

[0074] After acquiring the backlight angle information, the first rotation angle information, the emission time point, the backlight time point, and the second rotation angle information, processor 4 performs corresponding geometric calculations in the spatial coordinate system corresponding to the second reference position to obtain the spatial coordinates of the object point, thus determining the spatial position of the object point. The process of this geometric calculation is similar to the calculation process in the spatial coordinate system corresponding to the first reference position, and will not be described in detail here.

[0075] In addition to the fact that the second rotation axis is perpendicular to the first rotation axis, the angle between the second rotation axis and the first rotation axis can also be any value. In this case, the spatial coordinate system of the lidar can be set according to the actual detection situation. Under this coordinate system, the calculation process of the geometric relationship between the object point and the origin is similar to the above process, and will not be repeated here.

[0076] The above description is merely an optional embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A lidar, characterized in that, The lidar includes a first rotating base (1), a laser transmitter (2), a laser receiver (3), and a processor (4). The first rotating seat (1) includes a first rotating component (11) and a first fixing component (12), wherein the first rotating component (11) is mounted on the first fixing component (12); The laser emitter (2) and the laser receiver (3) are mounted on the first rotating member (11), and the laser emitter (2) and the laser receiver (3) rotate synchronously with the first rotating member (11); The first rotation axis of the first rotating member (11) passes through the laser receiver (3), and a portion of the first rotation axis is located within the detection range of the laser receiver (3); The laser receiver (3) includes multiple single-point detectors (31) that are equally spaced and distributed on the same straight line; The line containing the plurality of single-point detectors (31) is perpendicular to the first rotation axis; The central axis of the detection range of the laser receiver (3) passes through the midpoint of the line segment formed by the straight lines of the plurality of single-point detectors (31); The first rotation axis of the first rotating component (11) is parallel to the central axis of the detection range of the laser receiver (3). The distance between the first rotation axis of the first rotating component (11) and the central axis of the detection range of the laser receiver (3) is equal to d / 4, where d is the spacing between adjacent single-point detectors (31). The laser receiver (3) rotates 360° around the first rotation axis to form a circular field of view composed of multiple concentric rings. In the circular field of view, the number of concentric rings is equal to the number of single-point detectors (31) included in the laser receiver (3). Each concentric ring corresponds to one single-point detector (31), and each concentric ring is the detection trajectory of the corresponding single-point detector (31). The multiple concentric rings are evenly distributed in the radial direction. The first rotating base (1), the laser emitter (2), and the laser receiver (3) are electrically connected to the processor (4).

2. The lidar according to claim 1, characterized in that, The angle between the first rotation axis of the first rotating member (11) and the detection direction of the laser receiver (3) is equal to half of the detection field of view of the laser receiver (3).

3. The lidar according to claim 1 or 2, characterized in that, The lidar also includes a second rotating mount (5); The second rotating seat (5) includes a second rotating component (51) and a second fixing component (52), wherein the second rotating component (51) is mounted on the second fixing component (52); The first fixing member (12) is fixed on the second rotating member (51), and the first fixing member (12) rotates with the second rotating member (51).

4. The lidar according to claim 3, characterized in that, The second rotation axis of the second rotating member (51) is perpendicular to the first rotation axis of the first rotating member (11).

5. The lidar according to claim 1, characterized in that, The laser receiver (3) is a direction-adjustable laser receiver.

6. The lidar according to claim 1, characterized in that, The processor (4) is used for: Send a laser emission command to the laser emitter (2); Receive the return angle information sent by the laser receiver (3); Obtain the first rotation angle information of the first rotating component (11) in the first rotating seat (1) relative to the first reference position when the backlight angle information is received; Based on the backlight angle information, the rotation angle information, the emission time point, and the backlight time point, the spatial position of the object point corresponding to the backlight angle information is determined, wherein the emission time point is the time point at which the laser emission command is sent, and the backlight time point is the time point at which the backlight angle information is received.

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