Laser radar

Abstract

The invention discloses a laser radar, and belongs to the technical field of laser radars. In the application, based on the detection laser emitted by the laser radar emission channel group, the window sheet arranged at the laser radar light outlet is adjusted, so that the optical axis of the detection laser is not perpendicular to the light outlet surface of the window sheet. After the design of the optical system of the laser radar is completed, the detection laser of each transmitting channel of the laser radar is determined, and the angle between the laser radar diaphragm and the optical axis of the detection laser is adjusted to be not 90 degrees, so that reflected light perpendicular to the light-emitting surface of the diaphragm is prevented from being generated as far as possible from the design end; therefore, the first detection laser passes through the first light-emitting surface of the diaphragm to complete the detection of the first detection area, and correspondingly, the first echo laser passes through the first light-emitting surface and is received by the first receiving channel group. And the angle between the optical axis of the first detection laser and the first light emitting surface is not 90 degrees, so that a laser radar leading phenomenon caused by the diaphragm is avoided.

Description

Technical Field

[0001] The present application relates to the technical field of laser radar, and in particular to a laser radar. Background Art

[0002] The preamble can characterize the receiving response caused by the internal stray light of the lidar, because the receiving response caused by the stray light can easily cover the waveform of the detection echo signal of the close-range target object, resulting in poor accuracy of the detection echo signal, thus affecting the close-range detection capability of the lidar. Summary of the invention

[0003] The main purpose of this application is to provide a laser radar, aiming to provide a laser radar that reduces the influence of the leader on the laser radar detection through the design optimization of the laser radar window piece and improves the detection capability of the laser radar.

[0004] To achieve the above-mentioned object, the present application provides a laser radar, which includes a window piece, a first transmitting channel group and a first receiving channel group;

[0005] The first emission channel group is used to emit a first detection laser;

[0006] The first receiving channel group is used to receive the first echo laser returned by the detected object by the first detection laser;

[0007] The window piece is arranged at the light outlet of the laser radar, the first detection laser passes through the first light outlet surface of the window piece to complete the detection of the first detection area, and the first echo laser passes through the first light outlet surface to be received by the first receiving channel group;

[0008] The angle between the optical axis of the first detection laser and the first light-emitting surface is not 90 degrees.

[0009] Exemplarily, the angle between the optical axis of the first detection laser and the first light emitting surface is determined according to the emission angle of the emission light of the first emission channel group, the emission power of the first emission channel group, and the channel density of the first emission channel group.

[0010] Exemplarily, the laser radar further includes a second transmitting channel group and a second receiving channel group;

[0011] The second emission channel group is used to emit a second detection laser;

[0012] The second receiving channel group is used to receive the second echo laser returned by the detected object from the second detection laser;

[0013] The second detection laser passes through the second light-emitting surface of the window piece to complete the detection of the second detection area, and the second echo laser passes through the second light-emitting surface to be received by the second receiving channel group;

[0014] The angle between the optical axis of the second detection laser and the second light-emitting surface is not 90 degrees; the angle between the first light-emitting surface and the second light-emitting surface is different.

[0015] Exemplarily, the inclination of the window piece is obtained by simulating and fitting the inclination of the first light emitting surface and the inclination of the second light emitting surface.

[0016] Exemplarily, an anti-reflection film is provided in a local area of ​​the window piece, and the local area is a region where the first light emitting surface and the second light emitting surface of the window piece are connected.

[0017] Exemplarily, a local area of ​​the window piece is a non-uniform curved surface, and the local area is an area where the first light emitting surface and the second light emitting surface of the window piece are connected.

[0018] Exemplarily, the laser radar includes a third transmitting channel group, wherein the third transmitting channel group is a transmitting channel group corresponding to the local area, wherein the third transmitting channel group first transmits a third detection laser, and uses the third detection laser to perform close detection;

[0019] After the near detection is completed, a fourth detection laser is emitted to perform far detection, wherein the duration of the far detection is greater than the leading recovery duration after the near detection, and the local area is the area where the first light emitting surface and the second light emitting surface of the window piece are connected.

[0020] Exemplarily, the emission area of ​​the emitted light corresponding to a local area of ​​the window piece of the laser radar is smaller than a preset area, wherein the local area is an area where the first light emitting surface and the second light emitting surface of the window piece are connected.

[0021] Exemplarily, on a local area of ​​the window piece of the laser radar, the transmission power or the receiving efficiency corresponding to the local area is adjusted, wherein the local area is the area where the first light emitting surface and the second light emitting surface of the window piece are connected.

[0022] Exemplarily, the first detection area is the central detection area of ​​the laser radar, and the second detection area is the edge detection area of ​​the laser radar.

[0023] A laser radar is proposed in an embodiment of the present application, and the laser radar includes a window piece, a first transmitting channel group and a first receiving channel group; the first transmitting channel group is used to transmit a first detection laser; the first receiving channel group is used to receive a first echo laser returned by the first detection laser from the detected object; the window piece is arranged at the light exit port of the laser radar, the first detection laser passes through the first light exit surface of the window piece to complete the detection of the first detection area, and the first echo laser passes through the first light exit surface to be received by the first receiving channel group; the angle between the optical axis of the first detection laser and the first light exit surface is not 90 degrees.

[0024] In the present application, based on the detection laser emitted by the laser radar transmitting channel group, the window piece arranged at the laser radar light outlet is adjusted so that the optical axis of the detection laser is not perpendicular to the light emitting surface of the window piece. After the optical system design of the laser radar is completed, the detection laser of each transmitting channel of the laser radar is determined, and the angle between the optical axis of the laser radar window piece and the detection laser is adjusted not to be 90 degrees, so as to avoid the generation of reflected light perpendicular to the light emitting surface of the window piece as much as possible from the design end, so that the first detection laser passes through the first light emitting surface of the window piece to complete the detection of the first detection area, and correspondingly, the first echo laser passes through the first light emitting surface and is received by the first receiving channel group, and the angle between the optical axis of the first detection laser and the first light emitting surface is not 90 degrees, thereby avoiding the laser radar leading phenomenon caused by the window piece. In this way, the design optimization of the laser radar window piece is realized to reduce the influence of the leading on the laser radar detection and improve the detection capability of the laser radar. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of the optical path of an embodiment of a leading optimization method for a laser radar window piece involved in an embodiment of the present application;

[0026] Figure 2 A schematic diagram of a laser radar housing according to an embodiment of a leading optimization method for a laser radar window according to an embodiment of the present application;

[0027] Figure 3 A schematic diagram of the angle of an embodiment of a leading optimization method for a laser radar window piece involved in an embodiment of the present application;

[0028] Figure 4 This is a schematic diagram of surface optimization of an embodiment of a leading optimization method for a laser radar window piece involved in an embodiment of the present application.

[0029]

[0030]

[0031] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0032] It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0033] In order to ensure sufficient detection capabilities, laser radar uses light-sensitive detectors to detect the weaker echo energy of distant target objects. In this case, inside the laser radar, stray light from the emitting light source outside the theoretical design will have a high probability of being received by the detector, thus forming a leading phenomenon: the detector will receive strong internal echo energy of the machine for a certain short period of time, causing the detector to saturate. During the process of detector saturation recovery, the laser radar is in an inoperable state, and the laser radar loses its detection capability within this time range, resulting in the generation of blind spots.

[0034] For the leading phenomenon caused by stray light between the light-transmitting and light-emitting path components and the stray light of the coaxial light path components, the stray light of such components can be improved through structural design or surface extinction treatment.

[0035] As for the leading phenomenon caused by the stray light reflected by the window between the light receiving and light transmission paths, it is impossible to adopt the leading optimization method similar to that caused by the above-mentioned structural parts. Instead, the whole window is often coated with an anti-reflection film on one or both sides, or a larger angle is formed between the surface of the whole window and the outgoing light as much as possible to reduce the overall reflected light of the window. However, these methods are all for overall adjustment of the window, and no precise and targeted leading optimization of the window is performed. Furthermore, even after the overall adjustment of the window, there will still be a local area of ​​the window perpendicular to the outgoing light, resulting in the leading phenomenon.

[0036] The embodiment of the present application provides a laser radar, which includes a window piece, a first transmitting channel group and a first receiving channel group;

[0037] The first emission channel group is used to emit a first detection laser;

[0038] The first receiving channel group is used to receive the first echo laser returned by the detected object by the first detection laser;

[0039] The window piece is arranged at the light outlet of the laser radar, the first detection laser passes through the first light outlet surface of the window piece to complete the detection of the first detection area, and the first echo laser passes through the first light outlet surface to be received by the first receiving channel group;

[0040] The angle between the optical axis of the first detection laser and the first light-emitting surface is not 90 degrees.

[0041] In the present application, it is considered that the main reason for the leading phenomenon caused by the window piece is that: the angles of the outgoing light from different emission channels are different. Since the outgoing light at different angles and positions may form a vertical incidence with the local surface of the window piece, there is a relatively large amount of outgoing light that is not transmitted, so that the outgoing light corresponding to some channels forms a relatively large reflected light inside the laser radar, which leads to the leading phenomenon caused by the window piece.

[0042] Therefore, in this embodiment, the surface shape of the laser radar window piece is adjusted, the local surface shape of the original window piece is processed and modified, and the local area of ​​the window piece is adjusted so that the angle between the optical axis of each detection laser of the laser radar and the light-emitting surface of the window piece is not 90 degrees. In this way, the window piece is not adjusted as a whole, but the window piece is optimized in a targeted, precise and accurate local manner to optimize the leading phenomenon caused by the local parts of the window piece.

[0043] In one embodiment, referring to Figure 1 , Figure 1 Schematic diagram of a coaxial laser radar, which usually includes a transmitting device A, a receiving device B and a beam splitter D. The beam splitter D can achieve a semi-transparent and semi-reflective effect. The beam splitter D can be a glue layer, a coated glass or a hole-punched reflector, for example Figure 1 As shown in the figure, the laser emitted from the transmitting device A can be made to pass through the beam splitter D to reach the window C for emission, while the echo laser passes through the window C to reach the beam splitter D for reflection to the receiving device B.

[0044] In one embodiment, referring to Figure 2 The shell assembly of the laser radar 200 includes a base 202 and an upper shell 201. A window piece 203 may be formed on the side wall of the upper shell 201. At least one laser transceiver module is arranged in the shell assembly. The outgoing light signal passes through the window piece 203 to emit outward, and the reflected light signal passes through the window piece 203 to emit into the interior of the shell assembly.

[0045] In one embodiment, the window piece 203 can be tilted so that the emitted light signal is not perpendicular to the window piece 203. Since the window piece 203 itself has a certain mirror reflection, if the emitted light signal is perpendicular to the window piece 203, part of the emitted light signal reflected by the mirror is also perpendicular to the window piece 203 and returns; part of the emitted light signal becomes stray light, enters the laser transceiver module and is received by the laser transceiver module, causing a close-range blind spot, affecting the ranging capability and accuracy of the laser radar 200. Therefore, the window piece 203 is tilted so that the emitted light signal is not perpendicular to the window piece 203; part of the emitted light signal reflected by the window piece 203 is emitted in other directions, and will not return to the original path to be received and then enter the laser transceiver module.

[0046] In one embodiment, the window piece 203 is disposed obliquely downward; part of the outgoing light signal reflected by the window piece 203 is transmitted downward, and the possibility of being reflected or scattered by other structures in the housing assembly and entering the laser transceiver module is small.

[0047] It is worth noting that the shape of the window piece 203 can be a plane or a curved surface, as long as it can ensure that the outgoing light signal within the scanning range is not perpendicular to the window piece 203, and no specific limitation is made here. Preferably, the shape of the window piece 203 is a curved surface, which can minimize the width of the window piece 203 without blocking the outgoing light signal and the reflected light signal within the overall field of view of the laser radar 200, thereby providing a prerequisite for compressing the overall volume of the laser radar 200.

[0048] The transmitting channel group of the laser radar refers to a set of channels used to transmit laser beams in the laser radar, and each channel includes at least one laser transmitter. Generally, the transmitting channel group of the laser radar consists of multiple transmitting channels. Among them, the laser radar also includes a receiving channel, and the corresponding relationship between the transmitting channel and the receiving channel can be one-to-one, or one-to-many, and the present application does not limit the corresponding relationship between the transmitting channel and the receiving channel. In some optional embodiments, each channel usually has an optical element matched with it, such as a lens or a collimating fiber. In some optional embodiments, as a coaxial laser radar system, a beam splitter is also provided between the transmitting channel and the receiving channel, and the function of the beam splitter is to transmit the transmitting light path and reflect the echo light path, or the function of the beam splitter is to reflect the transmitting light path and transmit the echo light path. In some optional embodiments, the laser radar also includes a scanning part, and the scanning part can be a rotating mirror, a galvanometer or a rotating drive platform, etc., and the present application does not limit this. It can be understood that the laser radar achieves complete detection by having different vertical and horizontal detection field angles corresponding to different transmission channels in the transmission channel, or the laser radar can also achieve detection of the complete field of view through scanning.

[0049] The receiving channel group of the laser radar corresponding to the transmitting channel group of the laser radar refers to a set of channels used to receive the laser signal reflected from the target, and each receiving channel includes at least one photodetector and related electronic components. Usually, the receiving channel group of the laser radar consists of multiple receiving channels, each of which usually has a separate photodetector, as well as matching amplifiers, filters and other electronic components. These channels can simultaneously receive laser signals reflected from different directions and convert them into electrical signals for subsequent processing.

[0050] The laser radar's transmitting channel group and receiving channel group work closely together to complete the laser measurement and data acquisition of the target. First, the transmitting channel group is responsible for emitting the laser beam, that is, the first transmitting channel group emits the first detection laser. And adjust the emitted laser beam through appropriate optical elements. These laser beams cover the field of view of the laser radar, so as to illuminate the target in the area to be measured. Then, when the laser beam is irradiated on the target and reflected back, the receiving channel group starts to work, that is, the first receiving channel group receives the first echo laser returned by the detected object of the first detection laser. Each channel in the receiving channel group receives the laser signal returned from different directions, and the photoelectric detector converts the laser signal into an electrical signal, and outputs it after amplification, filtering and other processing.

[0051] The first detection laser passes through the first light emitting surface of the window piece to complete the detection of the first detection area, and correspondingly, the first echo laser passes through the first light emitting surface and is received by the first receiving channel group, and the angle between the optical axis of the first detection laser and the first light emitting surface is not 90 degrees.

[0052] In one embodiment, referring to Figure 3 First, determine the intersection of the first detection laser S emitted by the first emission channel group of the laser radar and the first light emitting surface P of the laser radar window. In this embodiment, the specific determination method and process are not limited or repeated.

[0053] Secondly, at the first light-emitting surface P of the window piece at the intersection point, determine the normal vector N along the emission direction of the first detection laser S, that is, the vector along the emission direction of the first detection laser S that is perpendicular to the first light-emitting surface P of the window piece at the intersection point. Next, determine the angle a between the first detection laser S and the normal vector N.

[0054] Reference Figure 4 Finally, the surface shape of the window piece is adjusted so that the angle a is greater than the preset fixed angle corresponding to the laser radar, so that the angle between the optical axis of the first detection laser S and the first light-emitting surface P is not 90 degrees, thereby performing targeted, precise and accurate leading optimization on the window piece, and optimizing the leading phenomenon caused by the window piece. Among them, the preset fixed angle refers to the angle that can avoid the leading phenomenon caused by the window piece, and the preset fixed angle of each local area of ​​the window piece can be pre-calibrated. In this embodiment, the calibration method is not limited.

[0055] In this embodiment, based on the detection laser emitted by the laser radar transmitting channel group, the window piece arranged at the laser radar light outlet is adjusted so that the optical axis of the detection laser is not perpendicular to the light exit surface of the window piece. After the optical system design of the laser radar is completed, the detection laser of each transmitting channel of the laser radar is determined, and the angle between the optical axis of the laser radar window piece and the detection laser is adjusted not to be 90 degrees, so as to avoid the generation of reflected light perpendicular to the light exit surface of the window piece as much as possible from the design end, so that the first detection laser passes through the first light exit surface of the window piece to complete the detection of the first detection area, and correspondingly, the first echo laser passes through the first light exit surface and is received by the first receiving channel group, and the angle between the optical axis of the first detection laser and the first light exit surface is not 90 degrees, thereby avoiding the laser radar leading phenomenon caused by the window piece. In this way, the design optimization of the laser radar window piece is realized to reduce the influence of the leading on the laser radar detection and improve the detection capability of the laser radar.

[0056] Exemplarily, the angle between the optical axis of the first detection laser and the first light emitting surface is determined according to the emission angle of the emission light of the first emission channel group, the emission power of the first emission channel group, and the channel density of the first emission channel group.

[0057] The angle between the optical axis of the first detection laser and the first light emitting surface depends on the emission angle of the emission light of the first emission channel group, the emission power of the first emission channel group and the channel density of the first emission channel group. These factors together determine the spatial distribution and angular characteristics of the laser beam when it is emitted from the emission channel group.

[0058] Among them, it can be understood that the closer the angle between the optical axis of the first detection laser and the first light-emitting surface is to 90 degrees, the greater the possibility of reflection back to the receiving channel. The more the angle between the optical axis of the first detection laser and the first light-emitting surface deviates from 90 degrees, the smaller the possibility of reflection back to the receiving channel. Among them, it can be understood that when the transmission power of the first emission channel group is greater, the energy emitted on the window piece is stronger. In order to reduce the influence of the leader on the receiving channel, it is necessary to make the angle between the optical axis of the emission light of the emission channel and the first light-emitting surface deviate from 90 degrees more. Among them, it can be understood that the higher the channel density of the first emission channel group, the higher the corresponding receiving channel density. Then the leader generated by the detection light emitted by the emission channel on the window piece is stronger for the crosstalk of the receiving channel. Therefore, in order to reduce the influence of the leader on the receiving channel, it is necessary to make the angle between the optical axis of the emission light of the emission channel and the first light-emitting surface deviate from 90 degrees more. It can be understood that the angle between the optical axis of the first detection laser and the first light-emitting surface is also related to the emission angle of the emission light corresponding to the first emission channel. It can be understood that the angle between the optical axis of the first detection laser and the first light-emitting surface is also related to the distance of the central field of view corresponding to the first transmitting channel group. When the first transmitting channel corresponds to the central field of view of the laser radar, in order to avoid the laser emitted by the transmitting channel from affecting the receiving channel, it is necessary to reduce the crosstalk effect of the leading edge on the receiving channel.

[0059] The emission angle of the emission channel group refers to the horizontal and vertical diffusion angle of the laser beam emitted from each emission channel. Different emission channels may have different emission angle settings to control the degree of laser beam broadening. A smaller emission angle can make the laser beam more concentrated, which is suitable for applications that require a longer range or higher measurement accuracy; while a larger emission angle can achieve a wider coverage range, which is suitable for wide-angle perception and fast scanning.

[0060] Among them, the transmission power of the transmission channel group affects the intensity and penetration of the laser beam. The greater the transmission power, the higher the energy of the laser beam, which can better penetrate interference factors such as the atmosphere, rain and fog, and help to obtain longer-distance measurements.

[0061] The channel density of the transmission channel group refers to the distribution of the number of channels in the transmission channel group and the unit length. A higher channel density can achieve a higher point cloud density and data sampling rate, thereby providing more detailed and accurate environment capture.

[0062] Exemplarily, the laser radar further includes a second transmitting channel group and a second receiving channel group;

[0063] The second emission channel group is used to emit a second detection laser;

[0064] The second receiving channel group is used to receive the second echo laser returned by the detected object from the second detection laser;

[0065] The second detection laser passes through the second light-emitting surface of the window piece to complete the detection of the second detection area, and the second echo laser passes through the second light-emitting surface to be received by the second receiving channel group;

[0066] The angle between the optical axis of the second detection laser and the second light-emitting surface is not 90 degrees; the angle between the first light-emitting surface and the second light-emitting surface is different.

[0067] In this embodiment, the laser radar includes, in addition to the first transmitting channel group and the corresponding first receiving channel group, a second transmitting channel group and a corresponding second receiving channel group. The second detection laser emitted by the second transmitting channel group passes through the second light emitting surface of the window piece to complete the detection of the second detection area, and the second receiving channel group receives the second detection laser returned by the detected object through the second light emitting surface of the window piece.

[0068] The angle between the optical axis of the second detection laser and the second light emitting surface of the window piece is also not 90 degrees, and the angle between the first light emitting surface and the second light emitting surface of the window piece is different.

[0069] The first detection laser is emitted through the first emission channel group and passes through the first light emitting surface of the window piece, thereby completing the detection of the first detection area in the central detection area of ​​the laser radar, and the first echo laser returned by the detection object in the first detection area from the first detection laser is received through the first light emitting surface by the first receiving channel group, thereby completing the detection of the central detection area of ​​the laser radar;

[0070] The second detection laser is emitted through the second transmitting channel group and passes through the second light emitting surface of the window piece, thereby completing the detection of the second detection area in the edge detection area of ​​the laser radar, and the second echo laser returned by the detection object in the second detection area is received by the second receiving channel group through the second light emitting surface, thereby completing the detection of the edge detection area of ​​the laser radar.

[0071] Considering that it is difficult to perform window lead optimization design for each transmitting channel and the corresponding receiving channel, the transmitting channel and the corresponding receiving channel of the lidar are grouped, and the window lead optimization design is performed on each group of transmitting channels and corresponding receiving channels after grouping, so as to reduce the calculation amount of the lead optimization design while ensuring the basic effect of the window lead optimization design.

[0072] The angle between the optical axis of the second detection laser and the second light emitting surface is determined according to the emission angle of the emission light of the second emission channel group, the emission power of the second emission channel group and the channel density of the second emission channel group.

[0073] Exemplarily, the inclination of the window piece is obtained by simulating and fitting the inclination of the first light emitting surface and the inclination of the second light emitting surface.

[0074] The window piece at least includes a first light emitting surface corresponding to the central detection area of ​​the laser radar, and a second light emitting surface corresponding to the edge detection area of ​​the laser radar. The inclination of the window piece can be obtained by simulating and fitting the inclination of the first light emitting surface and the inclination of the second light emitting surface, thereby realizing the leading optimization design of the window piece in the central detection area and the edge detection area of ​​the laser radar.

[0075] Exemplarily, an anti-reflection film is provided in a local area of ​​the window piece, and the local area is a region where the first light emitting surface and the second light emitting surface of the window piece are connected.

[0076] The junction area between the first light emitting surface and the second light emitting surface of the window piece may not meet the leading optimization design requirements. Therefore, in this embodiment, the junction area between the first light emitting surface and the second light emitting surface of the window piece is first determined, and the surface reflectivity is reduced in the local junction area. The surface reflectivity of the local area can be reduced by coating an anti-reflection film, and the reflected light that causes the leading phenomenon can be absorbed by a light-absorbing plate arranged on the inner wall of the laser radar housing.

[0077] Thus, the situation that the leading optimization design requirements may not be met in the junction area of ​​the first light-emitting surface and the second light-emitting surface of the window piece can be avoided, and the optimization effect of the leading optimization design of the window piece is performed on each group of the grouped transmitting channels and the corresponding receiving channels after the laser radar is grouped, so that the leading optimization design requirements can also be met in the junction area of ​​the first light-emitting surface and the second light-emitting surface of the window piece. In addition, the area of ​​the anti-reflection film or the light-absorbing plate set on the window piece can be effectively reduced, and the anti-reflection film can be set only in the local area of ​​the window piece, thereby reducing the cost of coating or adding the light-absorbing plate, and reducing the failure risk of the specific setting in the process of reducing the surface reflectivity of the local area.

[0078] Exemplarily, a local area of ​​the window piece is a non-uniform curved surface, and the local area is an area where the first light emitting surface and the second light emitting surface of the window piece are connected.

[0079] There may be a situation where the requirements of the leading optimization design are not met in the junction area between the first light emitting surface and the second light emitting surface of the window piece. Therefore, in this embodiment, the junction area of ​​the first light emitting surface and the second light emitting surface of the window piece is first determined, and then the angle between the detection laser and the normal vector along the exit direction of the outgoing light in the local area of ​​the window piece is adjusted by a non-uniform curved surface in the local area of ​​the junction, so that the angle between the optical axis of the detection laser and the light emitting surface in the local area is not 90 degrees, thereby avoiding the situation where the requirements of the leading optimization design may not be met in the junction area between the first light emitting surface and the second light emitting surface of the window piece, ensuring that after the laser radar's transmitting channel and the corresponding receiving channel are grouped, the optimization effect of the leading optimization design of the window piece is performed on each group of transmitting channels and the corresponding receiving channels after grouping, so that the requirements of the leading optimization design are also met in the junction area between the first light emitting surface and the second light emitting surface of the window piece. In addition, the window piece is also subjected to targeted, precise and accurate leading optimization to achieve the leading optimization of the local area of ​​the laser radar window piece.

[0080] Exemplarily, the laser radar includes a third transmitting channel group, wherein the third transmitting channel group is a transmitting channel group corresponding to the local area, wherein the third transmitting channel group first transmits a third detection laser, and uses the third detection laser to perform close detection;

[0081] After the near detection is completed, a fourth detection laser is emitted to perform far detection, wherein the duration of the far detection is greater than the leading recovery duration after the near detection, and the local area is the area where the first light emitting surface and the second light emitting surface of the window piece are connected.

[0082] The junction area between the first light emitting surface and the second light emitting surface of the window piece may fail to meet the requirements of the leader optimization design. Therefore, in this embodiment, the junction area between the first light emitting surface and the second light emitting surface of the window piece is first determined, and then a third detection laser with a preset low-energy pulse is used to perform near-field detection in the local junction area. However, at this time, the preset low-energy pulse will produce a leader phenomenon based on the local area, and the leader caused by the lower energy is weak and can be quickly recovered in a short time, thereby performing near-field detection with a low-energy pulse.

[0083] Since the time for performing far detection is preset to be longer than the preamble recovery time after performing near detection, far detection of preset high-energy pulses can be started at any time after the near detection ends. Among them, although far detection cannot be performed within the shorter recovery time of near detection, for the longer time of far detection, by sacrificing the shorter far detection time, a control method with simple process and low complexity can be obtained, and the far detection result can also be obtained.

[0084] Therefore, next, after the near detection is completed, a fourth detection laser of a preset high-energy pulse is emitted to perform far detection, wherein the duration of the far detection is greater than the leading recovery duration after the near detection.

[0085] Thus, by reasonably controlling the pulse energy and emission timing in the local area, further optimization of the local area of ​​the laser radar window can be achieved. Moreover, compared with non-surface adjustment and direct application of pulse energy and emission timing control to the entire window, the consumption and limitation of hardware and software resources of all channels in the full field of view can be effectively reduced, and the pulse energy and emission timing can be controlled only in the local area.

[0086] Exemplarily, the emission area of ​​the emitted light corresponding to a local area of ​​the window piece of the laser radar is smaller than a preset area, wherein the local area is the area where the first light emitting surface and the second light emitting surface of the window piece are connected.

[0087] The junction area between the first light emitting surface and the second light emitting surface of the window piece may fail to meet the requirements of the leading optimization design. Therefore, in this embodiment, the junction area between the first light emitting surface and the second light emitting surface of the window piece is first determined, and then the emission area of ​​the outgoing light in the local area is reduced in the local junction area. Thus, while avoiding a large leading echo, the detection task of the laser radar such as identifying objects can be achieved through the detection of adjacent channels in adjacent fields of view, and the leading phenomenon is avoided by sacrificing part of the detection accuracy to ensure the detection capability. In this embodiment, the method of achieving the detection task through adjacent detection situations is not limited.

[0088] Exemplarily, on a local area of ​​the window piece of the laser radar, the transmission power or the receiving efficiency corresponding to the local area is adjusted, wherein the local area is the area where the first light emitting surface and the second light emitting surface of the window piece are connected.

[0089] The connecting area between the first light emitting surface and the second light emitting surface of the window piece may not meet the leading optimization design requirements. Therefore, in this embodiment, the connecting area between the first light emitting surface and the second light emitting surface of the window piece is first determined, and then the transmission power or receiving efficiency corresponding to the local connecting area is adjusted to achieve precise and targeted leading optimization of the laser radar window piece.

[0090] It is understandable that when the transmission power of the transmission channel group is greater, and when the receiving efficiency of the receiving channel group is greater, the reflected energy on the window piece is stronger, and the preamble influence is greater. In order to reduce the influence of the preamble generated in the local area on the receiving channel, it is necessary to adjust the transmission power of the transmission channel group corresponding to the local area or the receiving efficiency of the receiving channel group to reduce the influence of the preamble on the receiving channel.

[0091] Among them, by adjusting the transmission power of the local area of ​​the window, the brightness and penetration of the laser beam can be improved when the transmission power is increased, thereby increasing the measurement distance and signal strength of the area. Reducing the transmission power can reduce the impact range of the area, which is suitable for some scenarios with low requirements for measurement distance and signal-to-noise ratio.

[0092] Among them, by adjusting the receiving efficiency of the local area of ​​the window, the intensity of the laser reflection signal received in the area can be changed. Improving the receiving efficiency can increase the signal quality and measurement accuracy of the area, which is suitable for scenes requiring high-precision measurement. Reducing the receiving efficiency can reduce the signal strength received in the area, which is suitable for scenes with high signal strength to prevent saturation and other problems.

[0093] Adjusting the transmit power or receiving efficiency of a local area can be achieved through the control parameters of the LiDAR system. The specific implementation method may vary depending on the specific LiDAR model and manufacturer. In general, by controlling the relevant hardware circuits or software interfaces, the transmit power and receiving efficiency of the LiDAR system can be locally adjusted to optimize the performance of a specific area.

[0094] Exemplarily, the first detection area is the central detection area of ​​the laser radar, and the second detection area is the edge detection area of ​​the laser radar.

[0095] The center detection area of ​​the laser radar refers to the area on the central axis of the laser beam in the point cloud data measured by the laser radar. In the center detection area, since the alignment of the laser beam on the central axis is high, the point cloud data collection and processing of the laser beam in this area are more reliable, so the measurement accuracy of the laser beam is usually high, and it can provide relatively accurate distance, angle and reflection intensity information. The edge detection area of ​​the laser radar refers to the area on the edge of the laser beam in the point cloud data measured by the laser radar. In the edge detection area, since the alignment of the laser beam in the edge area may be low, such as deviations caused by factors such as the divergence of the laser or the refraction of the laser beam, the measurement accuracy of the laser beam may be relatively low, and errors may occur due to the influence of some factors.

[0096] In the present application, based on the detection laser emitted by the laser radar transmitting channel group, the window piece arranged at the laser radar light outlet is adjusted so that the optical axis of the detection laser is not perpendicular to the light emitting surface of the window piece. After the optical system design of the laser radar is completed, the detection laser of each transmitting channel of the laser radar is determined, and the angle between the optical axis of the laser radar window piece and the detection laser is adjusted not to be 90 degrees, so as to avoid the generation of reflected light perpendicular to the light emitting surface of the window piece as much as possible from the design end, so that the first detection laser passes through the first light emitting surface of the window piece to complete the detection of the first detection area, and correspondingly, the first echo laser passes through the first light emitting surface and is received by the first receiving channel group, and the angle between the optical axis of the first detection laser and the first light emitting surface is not 90 degrees, thereby avoiding the laser radar leading phenomenon caused by the window piece. In this way, the design optimization of the laser radar window piece is realized to reduce the influence of the leading on the laser radar detection and improve the detection capability of the laser radar.

[0097] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or system. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or system including the element.

[0098] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application is essentially or the part that contributes to conventional technology can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, including a number of instructions for a terminal device (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods described in each embodiment of the present application.

[0099] The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A laser radar, characterized in that: The laser radar includes a window piece, a first transmitting channel group and a first receiving channel group; The first emission channel group is used to emit a first detection laser; The first receiving channel group is used to receive the first echo laser returned by the detected object by the first detection laser; The window piece is arranged at the light outlet of the laser radar, the first detection laser passes through the first light outlet surface of the window piece to complete the detection of the first detection area, and the first echo laser passes through the first light outlet surface to be received by the first receiving channel group; The angle between the optical axis of the first detection laser and the first light-emitting surface is not 90 degrees.

2. The laser radar according to claim 1, characterized in that The angle between the optical axis of the first detection laser and the first light emitting surface is determined according to the emission angle of the emission light of the first emission channel group, the emission power of the first emission channel group, and the channel density of the first emission channel group.

3. The laser radar according to claim 1, characterized in that The laser radar also includes a second transmitting channel group and a second receiving channel group; The second emission channel group is used to emit a second detection laser; The second receiving channel group is used to receive the second echo laser returned by the detected object from the second detection laser; The second detection laser passes through the second light-emitting surface of the window piece to complete the detection of the second detection area, and the second echo laser passes through the second light-emitting surface to be received by the second receiving channel group; The angle between the optical axis of the second detection laser and the second light-emitting surface is not 90 degrees; the angle between the first light-emitting surface and the second light-emitting surface is different.

4. The laser radar according to claim 3, characterized in that: The inclination of the window piece is obtained by simulating and fitting the inclination of the first light emitting surface and the inclination of the second light emitting surface.

5. The laser radar according to claim 3, characterized in that: An anti-reflection film is disposed in a local area of ​​the window plate, and the local area is a region where the first light emitting surface and the second light emitting surface of the window plate are connected.

6. The laser radar according to claim 3, characterized in that: A local area of ​​the window piece is a non-uniform curved surface, and the local area is an area where the first light emitting surface and the second light emitting surface of the window piece are connected.

7. The laser radar according to claim 3, characterized in that: The laser radar includes a third transmitting channel group, wherein the third transmitting channel group is a transmitting channel group corresponding to the local area, wherein the third transmitting channel group first transmits a third detection laser, and uses the third detection laser to perform close detection; After the near detection is completed, a fourth detection laser is emitted to perform far detection, wherein the duration of the far detection is greater than the leading recovery duration after the near detection, and the local area is the area where the first light emitting surface and the second light emitting surface of the window piece are connected.

8. The laser radar according to claim 3, characterized in that: The emission area of ​​the emitted light corresponding to the local area of ​​the window piece of the laser radar is smaller than the preset area, wherein the local area is the area where the first light emitting surface and the second light emitting surface of the window piece are connected.

9. The laser radar according to claim 3, characterized in that: On a local area of ​​the window piece of the laser radar, the transmission power or the receiving efficiency corresponding to the local area is adjusted, wherein the local area is the area where the first light emitting surface and the second light emitting surface of the window piece are connected.

10. The laser radar according to claim 3, characterized in that: The first detection area is the central detection area of ​​the laser radar, and the second detection area is the edge detection area of ​​the laser radar.

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