Parameter optimization method of light receiving and transmitting path system, light receiving and transmitting path system and laser radar

Abstract

This application provides a parameter optimization method for a light-receiving path system, a light-receiving path system, and a lidar. The parameter optimization method includes: determining power characteristic parameters to represent the detection capability of the light-receiving path system; determining the size parameters of a via based on the power characteristic parameters, according to a preset spatial distribution of the light source and the transmit / receive area constraints of the light-receiving path system; determining the geometry of the via based on preset stray light suppression conditions; determining whether to install a first extinction sleeve at the via; and, given that a first extinction sleeve is installed at the via, determining whether to install a second extinction sleeve at a rotating reflector. This application, by determining the power characteristic parameters and combining them with the spatial distribution of the light source and the transmit / receive area constraints, accurately calculates the optimal size of the via; by combining the stray light suppression conditions, it derives the geometry of the via and decides whether to install the first and second extinction sleeves, thereby improving the efficiency of the light-receiving path and enabling the lidar to achieve greater ranging capability.

Description

Technical Field

[0001] This application relates to the field of lidar technology, and in particular to a parameter optimization method for a light-receiving and light-emitting path system, the light-receiving and light-emitting path system, and lidar. Background Technology

[0002] LiDAR (Light Detection and Ranging) works by emitting a laser beam at a target and detecting and receiving the echo signal from the target. It processes and analyzes the transmitted and received signals to obtain characteristics such as the target's position and velocity. The transceiver optical system plays a crucial role in the operation of LiDAR. With the development of LiDAR technology, while performance indicators are constantly improving, product miniaturization has gradually become a hot topic and a challenge in the industry. How to improve the efficiency of the transceiver optical path within a limited volume to enable the radar to achieve greater ranging capabilities is a problem that urgently needs to be solved in the industry and has significant practical implications. In related LiDAR technologies, the transmitting optical path can obstruct the received echo signal, affecting the transceiver efficiency and thus the detection performance of the LiDAR. Summary of the Invention

[0003] This application provides an improved parameter optimization method for a light-emitting circuit system, a light-emitting circuit system, and a lidar.

[0004] This application provides a parameter optimization method for a light receiving and transmitting path system, the light receiving and transmitting path system including a through-hole reflector and a rotating reflector; wherein, the light receiving and transmitting path system is used to guide the emitted light beam through the through-hole and transmit it to the rotating reflector, so as to scan and emit the emitted light beam outward through the rotating reflector; and is used to guide the echo signal reflected from the target to be reflected by the rotating reflector and then by the reflective surface of the through-hole reflector in sequence before receiving it; The parameter optimization method includes: Determine the power characteristic parameters used to characterize the detection capability of the receiving and transmitting optical path system; Based on the preset spatial distribution of the light source and the transmit / receive area constraints of the light-receiving path system, the size parameters of the through hole are determined according to the power characteristic parameters. Based on the preset stray light suppression conditions, the geometry of the through hole is determined, and it is determined whether a first matting sleeve is to be installed at the through hole. If it is determined that the first matting sleeve is to be installed at the through hole, it is determined whether a second matting sleeve is to be installed at the rotating mirror.

[0005] In some embodiments, determining the power characteristic parameters used to characterize the detection capability of the receiving and transmitting optical path system includes: The power characteristic parameters are determined based on the correlation characteristics between the minimum detectable power and internal noise, background light noise, and receiving focal length; wherein, When the minimum detectable power is affected by the internal noise to a greater extent than by the background light and is not related to the receiving focal length, the determined power characteristic parameter is the product of the light source output power and the area of ​​the receiving region. When the minimum detectable power is affected by the background light to a greater extent than by the internal noise and is correlated with the receiving focal length, the determined power characteristic parameter is the product of the light source output power, the area of ​​the receiving region, and the receiving focal length.

[0006] In some embodiments, determining the size parameters of the via based on the power characteristic parameters, according to the preset spatial distribution of the light source and the transmit / receive area constraints of the light-receiving path system, includes: Obtain the distribution relationship between the power characteristic parameters and the size parameters of the through hole; Based on the preset spatial distribution of light sources, and with the constraint that the light source intensity per unit area corresponding to the first directional boundary and the second directional boundary of the through hole is the same, the size parameters of the through hole are calculated and determined based on the distribution relationship.

[0007] In some embodiments, the preset spatial distribution of the light source is a Gaussian distribution; the constraint that the unit area light source intensity corresponding to the first direction boundary and the second direction boundary of the through hole is the same includes: Given that the through hole is a rectangular through hole, constrain the lateral dimension of the rectangular through hole. With longitudinal dimension The following relationship must be satisfied: ;or Under the condition that the through hole is an elliptical through hole, constrain the lateral half-axis of the elliptical through hole. With longitudinal half axis The following relationship must be satisfied: ; in, and These are the focal lengths of the emitting lens in the horizontal and vertical directions, respectively. and These are the divergence angle parameters in the horizontal and vertical directions, respectively.

[0008] In some embodiments, the distribution relationship of the power characteristic parameters as a function of the size parameters satisfies: The through hole is a square through hole with a dimension parameter of half the side length. Under the following conditions: ;or The through hole is a circular through hole with a radius as its dimensional parameter. Under the following conditions: ; in, Used to represent the light source output power of the light-receiving circuit system; Used to represent the effective receiving area of ​​the echo signal of the optical path system; The total radius of the sending and receiving area. The length of half a side of the square through hole. The radius of the circular through hole; and These are the divergence angle parameters in the horizontal and vertical directions, respectively; Used to indicate the central light intensity.

[0009] In some embodiments, the preset spatial distribution of the light source includes a distribution in which the light source intensity monotonically decreases from the center angle toward the edge.

[0010] In some embodiments, the power characteristic parameters are positively correlated with the maximum detection distance of the light-emitting circuit system.

[0011] In some embodiments, the power characteristic parameters are based on the maximum detection range of the receiving and transmitting optical path system. Constrain the relational expression: ; in, Used to indicate the maximum detection range of the light-emitting circuit system; Used to represent the light source output power of the light-receiving circuit system; Used to represent the target reflectivity of the light-receiving and receiving circuit system; Used to represent the effective receiving area of ​​the echo signal of the optical path system; Used to represent the relative intensity distribution of the emission angle of the light-emitting path system; Used to indicate the receiving efficiency of the receiving lens of the receiving optical path system; Used to indicate the emission efficiency of the emitting lens of the receiving and receiving light path system; Used to indicate the angle between the beam normal of the light-receiving and light-emitting path system and the target surface normal; This is used to represent the minimum detectable power of the light-emitting circuit system.

[0012] In some embodiments, determining the geometry of the through-hole according to a preset stray light suppression condition, and determining whether to provide a first extinction sleeve at the through-hole reflector, includes: When the stray light suppression condition indicates that the stray light index is within a preset noise range, the geometry of the via is determined to be a polygon, a circle, or an ellipse. When the stray light suppression condition indicates that the stray light index exceeds the noise range, a first matting sleeve is provided at the through hole; and along the optical axis direction of the light receiving and receiving path system, the geometry of the through hole and the cross-sectional shape of the first matting sleeve are determined according to the relative positional relationship between the orthographic projection of the first matting sleeve and the through hole area of ​​the through hole.

[0013] In some embodiments, when the orthographic projection is located within the through-hole area, the geometry of the through-hole and the cross-sectional shape of the first matting sleeve are both determined to be a square or rectangle that are consistent with each other. When the orthographic projection exceeds the through-hole area and obstructs the reflective surface of the through-hole reflector, the corresponding cross-sectional shape is selected based on the obstruction area of ​​the candidate cross-sectional shape of the first matting sleeve on the reflective surface, and the geometry of the through-hole is determined to be consistent with the selected cross-sectional shape.

[0014] In some embodiments, determining whether to install a second matting sleeve at the rotating mirror, given that the first matting sleeve is installed, includes: After the first matting sleeve is installed at the through hole, and when the stray light suppression condition indicates that the stray light index still exceeds the noise range, it is determined that the second matting sleeve is installed at the rotating mirror; and the geometry of the through hole, the cross-sectional shape of the first matting sleeve, and the cross-sectional shape of the second matting sleeve are all determined to be circular.

[0015] In some embodiments, the parameter optimization method further includes: determining the cross-sectional radius of the second matting sleeve as a circular cross-section based on the geometry of the through hole.

[0016] In some embodiments, when the geometry of the through hole is circular, the radius of the second matte sleeve is the same as the radius of the through hole.

[0017] In some embodiments, when the geometry of the through hole is elliptical, the radius of the second matte sleeve is determined to be the length of the semi-major axis of the ellipse.

[0018] In some embodiments, when the geometry of the through hole is square or rectangular, the radius of the second matte sleeve is determined to be half the length of the diagonal of the square or rectangular shape.

[0019] This application also provides a light receiving and receiving path system, including a through-hole reflector and a rotating reflector; the light receiving and receiving path system is used to guide the emitted light beam through the through-hole and transmit it to the rotating reflector, so that the emitted light beam is scanned outward by the rotating reflector; and is used to guide the echo signal reflected from the target to be reflected by the rotating reflector and then by the reflective surface of the through-hole reflector for reception; The size parameters of the through hole, the setting state of whether the through hole reflector is equipped with the first matting sleeve, and the setting state of whether the rotating reflector is equipped with the second matting sleeve are all determined by the parameter optimization method as described in any of the above embodiments.

[0020] In some embodiments, the setting state of the first matte sleeve and the second matte sleeve is determined by the parameter optimization method; wherein, In the parameter optimization method, the preset stray light suppression condition indicates that when the stray light index exceeds the noise range, it is determined that the first extinction sleeve is set at the through hole. After the first matting sleeve is installed at the through hole, and if the stray light suppression condition indicates that the stray light index still exceeds the noise range, it is determined that the second matting sleeve is installed at the rotating mirror.

[0021] In some embodiments, the light-receiving path system further includes a light-absorbing element disposed on the inner wall of the second matting sleeve. The distribution position and size of the light-absorbing element are determined by the difference in receiving area corresponding to different angles of the rotating reflector during rotational scanning.

[0022] In some embodiments, the light-receiving and receiving path system further includes a light-transmitting housing; the center point of the intersection of the rotating reflector and the optical axis of the light-receiving and receiving path system coincides with the geometric center of the housing.

[0023] This application also provides a lidar, including: A transmitting module, used to generate and emit a light beam; A receiving module is used to detect echo signals; and The light-receiving path system as described in any of the above embodiments is disposed on the optical path between the transmitting module and the receiving module; wherein, the light-receiving path system is used to guide the light beam through the through hole and transmit it to the rotating reflector, so as to scan and emit the light beam outward through the rotating reflector; and guide the echo signal reflected from the target to be reflected by the rotating reflector and the reflecting surface of the through hole reflector in sequence before being transmitted to the receiving module.

[0024] This application provides a parameter optimization method for a light-receiving and receiving path system, the light-receiving and receiving path system, and a lidar. The light-receiving and receiving path system of this application adopts a coaxial light-receiving and receiving path structure where the emitted beam passes through a via and the echo signal is reflected by a mirror surface within the via. In this structure, the size parameters of the via determine the transmission efficiency of the emitted beam and the effective area for receiving the echo; within a limited volume, these two factors constrain each other in terms of space and energy distribution. Simultaneously, edge scattering generated during the emission beam passing through the via and the deflection scanning of the rotating mirror is the main source of stray light within the system. Therefore, the parameter optimization method of this application establishes an evaluation benchmark for overall energy balance using determined power characteristic parameters. Combining the spatial distribution of the light source and the constraints of the transmit and receive areas, it accurately calculates the optimal size of the via that balances the transmission efficiency of the emitted beam and the minimization of the receiving blind zone. Based on this, a stray light suppression condition is introduced as a noise criterion, and the geometry of the via is derived in reverse. This serves as a logic switch, allowing for the selective setting of the first and second extinction sleeves in a cascaded manner along the spatial optical path, achieving on-demand graded suppression of stray light of different levels. This configuration solves the problem of how to improve the efficiency of the light transmission and reception path within a limited volume space, enabling the lidar to achieve greater ranging capabilities. Attached Figure Description

[0025] Figure 1 The diagram shown is a structural schematic of one embodiment of the lidar of this application.

[0026] Figure 2 As shown Figure 1 The flowchart shows an embodiment of the parameter optimization method for the receiver-light path system.

[0027] Figure 3 As shown Figure 1 The diagram shows the signal transmission and reception area of ​​the optical transmission and reception circuit system.

[0028] Figure 4 As shown Figure 1 The diagram shows a circular transceiver area of ​​the optical transmission and reception system.

[0029] Figure 5 As shown Figure 1 The diagram shows a square transceiver area of ​​the transceiver circuit system.

[0030] Figure 6 As shown Figure 1 The diagram shows the relationship between the power characteristic parameters of the light-emitting circuit system and the size of the square aperture.

[0031] Figure 7 As shown Figure 1 The diagram shows the relationship between the power characteristic parameters of the light-emitting circuit system and the diameter of the circular aperture.

[0032] Figure 8As shown Figure 1 The diagram shows a circular transceiver system with a rectangular transmitting area.

[0033] Figure 9 As shown Figure 1 The diagram shows a circular transceiver system with an elliptical transmitting region.

[0034] Figure 10 As shown Figure 1 The diagram shows the contour plot of the power characteristic parameters of the receiver-light path system as a function of the rectangular aperture size.

[0035] Figure 11 As shown Figure 1 The light-emitting circuit system shown Contour plot showing how power characteristic parameters vary with the aperture size of the ellipse.

[0036] Figure 12 As shown Figure 1 The light-emitting circuit system shown The relationship between power characteristic parameters and the lateral dimension of the rectangle under the constraint of equal strength per unit area in both directions.

[0037] Figure 13 As shown Figure 1 The light-emitting circuit system shown The relationship between power characteristic parameters and the lateral dimension of the ellipse under the constraint of equal strength per unit area in both directions.

[0038] Figure 14 As shown Figure 1 The light-emitting circuit system shown Power characteristic parameters relative to the rectangle's lateral dimensions and receiver focal length contour plot.

[0039] Figure 15 As shown Figure 1 The light-emitting circuit system shown Power characteristic parameters with respect to the lateral dimensions of the ellipse and the receiving focal length contour plot.

[0040] Figure 16 As shown Figure 1 The diagram shows a three-dimensional structure, a top view, and a frontal projection of the first matting sleeve of the light-receiving and light-emitting path system being flush with the circular through hole.

[0041] Figure 17 As shown Figure 1 The diagram shows a three-dimensional structure, a top view, and a frontal projection of the first matting sleeve of the light-emitting circuit system being flush with the square through hole.

[0042] Figure 18 As shown Figure 1 The diagram shows a three-dimensional structure, a top view, and a frontal projection of the first matting sleeve of the light-receiving and light-receiving path system, which is flush with the lower part of the reflector through a circular through-hole.

[0043] Figure 19 As shown Figure 1 The diagram shows a three-dimensional structure, a top view, and a frontal projection of the first matting sleeve of the light-receiving and light-receiving path system, which is flush with the lower part of the reflector through a square through-hole.

[0044] Figure 20 As shown Figure 1 The diagram shows the transmitting and receiving areas of the rotating reflector with a sleeve in the case of a circular through-hole reflector in the light transmission and receiving path system.

[0045] Figure 21 As shown Figure 1 The diagram shows the transmitting and receiving areas of the rotating mirror with a sleeve in the case of a square through-hole reflector in the light transmission and receiving path system.

[0046] Figure 22 As shown Figure 1 The diagram shows the structure of the rotating reflector of the light-receiving and light-receiving path system with a second anti-glare sleeve.

[0047] Figure 23 As shown Figure 1 The diagram shows the structure of the rotating reflector of the light-receiving and light-absorbing system with a second light-absorbing sleeve.

[0048] Figure 24 As shown Figure 1 The diagram shows the structural schematic of the housing of the light-emitting circuit system. Detailed Implementation

[0049] The parameter optimization method, the light-emitting path system, and the lidar of this application will be described in detail below with reference to the accompanying drawings. Unless otherwise specified, the features in the following embodiments and implementations can be combined with each other.

[0050] like Figure 1As shown, the lidar 1 includes a transmitting module 11, a receiving module 12, and a light-emitting and receiving path system 20, which is located on the optical path between the transmitting module 11 and the receiving module 12. The transmitting module 11 includes a laser 111 and a transmitting lens 112. The receiving module 12 includes a receiving lens 121 and a detector 122. The light-emitting and receiving path system 20 includes a through-hole reflector 21 and a rotating reflector 22. The transmitting module 11 generates and emits a light beam. The receiving module 12 detects the echo signal. The light-emitting and receiving path system 20 guides the light beam through the through-hole 211 of the through-hole reflector 21 and transmits it to the rotating reflector 22, so that the light beam is scanned outward by the rotating reflector 22. The light-emitting and receiving path system 20 also guides the echo signal reflected from the target to be transmitted sequentially through the rotating reflector 22 and the reflecting surface of the through-hole reflector 21 to the receiving module 12.

[0051] exist Figure 1 In the illustrated embodiment, the through-hole reflector 21 and rotating reflector 22 of the light-receiving path system 20, in conjunction with the transmitting module 11 and the receiving module 12, form an omnidirectional scanning detection system for the lidar 1. In this scanning detection system, the through-hole reflector 21 and rotating reflector 22 improve the flexibility of assembly and adjustment, and the transmitting module 11 does not obstruct the receiving module 12, thus not affecting the echo signal. Due to the interaction between the beam and the edge of the through-hole reflector 21, stray light may be generated, affecting the received detection signal. Furthermore, the light-receiving path system 20 adopts a coaxial light-receiving path structure where the transmitted beam passes through the through-hole 211 and the echo signal is reflected by the reflective surface of the through-hole reflector 211. In this structure, the size parameters of the through-hole 211 determine the transmission efficiency of the transmitted beam and the effective area for receiving the echo; within a limited volume, the two are mutually constrained in terms of space and energy distribution. Simultaneously, the edge scattering generated when the transmitted beam passes through the through-hole 211 and the rotating reflector 22 during deflection scanning is the main source of stray light within the system.

[0052] Therefore, in order to improve the transmission and reception efficiency of the lidar 1 and suppress stray light to a certain extent, the light transmission and reception path system 20 of this application adjusts the size parameters and geometry of the through hole 211, and according to the stray light amplitude, selectively sets a first extinction sleeve 23 at the through hole 211 of the through hole reflector 21, and selectively sets a second extinction sleeve on the light incident side of the rotating reflector 22. Figure 1 (Not shown in the image). The arrangement of the first matting sleeve 23 and the second matting sleeve 24 was optimized. Both the first matting sleeve 23 and the second matting sleeve 24 are made of low-reflectivity and opaque materials to isolate and suppress stray light.

[0053] Based on this, the light-absorbing element 25 and the light-transmitting shell 26 can be selectively configured in the light-receiving path system 20. The trade-off between the transmission and reception efficiency and the degree of stray light suppression is considered. A trade-off mechanism based on the detection signal threshold and the stray light signal amplitude is established to take into account both the degree of stray light suppression and the efficiency of the transmission and reception cross section. This solves the problem of how to improve the efficiency of the light-receiving path within a limited volume space, so that the lidar can obtain a greater ranging capability.

[0054] In some embodiments, the dimensional parameters of the through hole 211, the setting state of whether the through hole reflector 21 is equipped with the first matting sleeve 23, and the setting state of whether the rotating reflector 22 is equipped with the second matting sleeve 24 are all determined by... Figure 2 The parameter optimization method shown in the embodiment is determined by: The dimensional parameters and geometry of the through hole 211, and the spatial configuration of the first matte sleeve 23 and the second matte sleeve 24, are determined by... Figure 2 The method of the embodiment is determined to maximize the effective receiving area of ​​the echo while ensuring low stray light, thereby improving the detection signal-to-noise ratio of the system.

[0055] In some embodiments, when the light-absorbing element 25 is provided in the light-receiving path system 20, the light-absorbing element 25 is disposed on the inner wall of the second matting sleeve 24. The distribution position and size of the light-absorbing element 25 are determined by the difference in receiving area corresponding to different angles of the rotating reflector 22 during rotational scanning. In this embodiment, the light-absorbing element 25 can be a black strip, disposed on the inner wall of the second matting sleeve 24 and arranged in the vertical direction. During omnidirectional scanning, different scanning angles may cause changes in the overlap area of ​​the upper and lower sleeve blocking areas. By setting the light-absorbing element 25 according to the area difference, the fluctuation of the received signal intensity during the scanning process can be compensated and suppressed.

[0056] In some embodiments, when the light-transmitting light path system 20 is provided with a light-transmitting housing 26, the intersection point of the rotating reflector 22 and the center of the optical axis of the light-transmitting light path system 20 is set to coincide with the geometric center of the housing 26. By setting the intersection point of the rotating reflector 22 and the optical axis on the center of the spherical housing 26 or on the axis of the cylindrical housing 26, it is ensured that the probe light rays at all angles are transmitted along the normal direction of the light-transmitting housing 26, reducing the beam path deflection and scanning path distortion caused by the refraction of the housing 26.

[0057] Please refer to the following text for specific parameter optimization methods. Figure 2 As shown, the parameter optimization method includes steps S1 to S3. Among them, Step S1: Determine the power characteristic parameters used to represent the detection capability of the light-emitting path system 20. Determine the power reference parameters characterizing the overall detection capability of the system, which will serve as the quantitative evaluation basis for subsequent aperture size calculation and stray light suppression decisions.

[0058] Step S2: Based on the preset spatial distribution of the light source and the transmit / receive area constraints of the light-receiving path system 20, determine the size parameters of the through-hole 211 according to the power characteristic parameters. Based on the spatial distribution of the light source intensity and the mutual exclusion constraint of the transmit / receive area of ​​the system, and using the power characteristic parameters determined above as the energy judgment basis, calculate and determine the geometric dimensions of the through-hole boundary that meet the system's detection requirements.

[0059] Step S3: Based on the preset stray light suppression conditions, determine the geometry of the through-hole 211, and determine whether to install the first extinction sleeve 23 at the through-hole 211. Given that the first extinction sleeve 23 is installed at the through-hole 211, determine whether to install the second extinction sleeve 24 at the rotating mirror 22. By introducing the stray light suppression conditions as a noise judgment benchmark, the cross-sectional geometric profile of the through-hole 211 is derived and determined in reverse. Using this as a trigger condition, it is sequentially determined whether to install the first extinction sleeve 23 at the through-hole 211 and whether to install the second extinction sleeve 24 at the rotating mirror 22. Through this decision, an adaptive spatial arrangement of extinction can be achieved.

[0060] The parameter optimization method of this application uses determined power characteristic parameters as an evaluation benchmark for overall energy balance. Combined with the spatial distribution of the light source and the constraints of the transmitting and receiving areas, it accurately calculates the optimal size of the aperture that balances the transmission efficiency of the emitted beam and the minimization of the receiving blind zone. Based on this, a stray light suppression condition is introduced as a noise criterion, and the geometry of the aperture is derived in reverse. This serves as a logic switch, cascading the decision-making of the setting of the first extinction sleeve 23 and the second extinction sleeve 24 in the spatial optical path, achieving on-demand graded suppression of different levels of scattered stray light. This configuration solves the problem of how to improve the efficiency of the receiving and receiving optical paths within a limited volume space, enabling the lidar 1 to achieve greater ranging capabilities.

[0061] In the application of lidar 1, due to the size and motor parameter constraints of lidar 1, its effective cross-section for transmitting and receiving signals is relatively small, equivalent to the vertical projected area of ​​the rotating reflector 22. According to the lidar 1 equation, the power characteristic parameters are based on the maximum detection range of the light-receiving and receiving path system 20. The maximum detection range is constrained by the relational formula. It can be represented as: (1) In the above formula (1), Used to indicate the maximum detection range of the light-emitting circuit system 20; Used to indicate the output power of the light source in the light-emitting circuit system 20; Used to represent the target reflectivity of the light-emitting circuit system 20; Used to represent the effective receiving area of ​​the echo signal of the receiving and receiving optical path system 20; Used to represent the relative intensity distribution of the emission angle of the light-emitting path system 20; Used to indicate the receiving efficiency of the receiving lens of the light-receiving path system 20; Used to indicate the emission efficiency of the emitting lens of the light receiving and receiving circuit system 20; Used to indicate the angle between the beam normal of the receiving and receiving light path system 20 and the target surface normal; This indicates the minimum detectable power of the light-emitting circuit system 20. The maximum detection distance is also indicated. In addition, variables such as optical efficiency, target reflectivity, and spatial angle of the entire link are introduced as boundary constraints to power characteristic parameters, realizing the mapping from component-level parameter optimization to the closed loop of overall ranging performance.

[0062] In some embodiments, step S1, determining the power characteristic parameters used to represent the detection capability of the light-receiving path system 20, includes: determining the power characteristic parameters based on the correlation characteristics of the minimum detectable power with internal noise, background light noise, and receiving focal length. Combining the above formula (1), it can be seen that if the light-receiving path system 20 of the lidar 1 is affected by internal noise, then the aforementioned minimum detectable power... With the receiving focal length Irrelevant. If the light-receiving path system 20 of lidar 1 is affected by background light noise, then the aforementioned minimum detectable power... With the receiving focal length Related. In this embodiment, the correlation between minimum detectable power and receiving focal length is used as a variable, and the corresponding optimization strategy is switched according to the change of the noise-dominant factor.

[0063] In some embodiments, when the minimum detectable power is more affected by internal noise than by background light and is not correlated with the receiving focal length, the determined power characteristic parameter is the product of the light source output power and the area of ​​the receiving region. In this embodiment, where the minimum detectable power is less correlated with the receiving focal length and is mainly affected by internal noise, the parameter is simplified to the product of the light source output power and the area of ​​the receiving region. This eliminates the interference of focal length changes on noise settings, thereby ensuring the transmission and reception efficiency in this application scenario.

[0064] In some embodiments, when the minimum detectable power is more affected by background light than by internal noise and is correlated with the receiving focal length, the determined power characteristic parameter is the product of the light source output power, the area of ​​the receiving region, and the receiving focal length. In this embodiment, in scenarios where the minimum detectable power is highly correlated with the receiving focal length and is mainly affected by background light noise, the parameter is simplified to the product of the light source output power, the area of ​​the receiving region, and the receiving focal length. This balances the constraint between increasing the back focal length and suppressing background light noise, ensuring the optimal detection size in this strong background light environment.

[0065] In some embodiments, the power characteristic parameters are positively correlated with the maximum detection distance of the light-receiving circuit system 20. In some embodiments, where the minimum detectable power is mainly affected by internal noise and has little correlation with the receiving focal length, the larger the product of the light source output power and the area of ​​the receiving region, the higher the transceiver efficiency and the longer the corresponding maximum detection distance. Conversely, in this scenario, the smaller the product of the light source output power and the area of ​​the receiving region, the lower the transceiver efficiency and the shorter the corresponding maximum detection distance. In other embodiments, where the minimum detectable power is mainly affected by background light noise and has a high correlation with the receiving focal length, the larger the product of the light source output power, the area of ​​the receiving region, and the receiving focal length, the higher the transceiver efficiency and the longer the corresponding maximum detection distance. Conversely, in this scenario, the smaller the product of the light source output power, the area of ​​the receiving region, and the receiving focal length, the lower the transceiver efficiency and the shorter the corresponding maximum detection distance.

[0066] Assuming the background light noise is uniformly distributed in angular space, due to the receiving focal length The larger the focal length, the smaller the field of view. Near a small field of view, the focal length and noise power can be considered inversely proportional. ,thereby Since the transmit and receive apertures share the same aperture, the effect of focal length on light emission needs to be considered. Increasing the focal length means that, for the same aperture size, the output power of the light source will increase with the increase in back focal length. It will vary depending on the receiving focal length The increase and decrease are related to the spatial distribution of the emitted beam angle, and the relationship is quite complex. If the aperture is constant and the intensity is uniform, it satisfies an inverse proportional relationship. The larger the characteristic parameter, the greater the maximum detection range. The larger.

[0067] With other parameters remaining constant, the optimized transmit / receive efficiency is calculated for the shared transmit / receive interface to maximize the ranging capability; that is, the result is... or The maximum detection distance corresponding to the maximum value This is also the maximum value, thus indicating that LiDAR 1 has the strongest ranging capability.

[0068] In some embodiments, in step S2, based on a preset spatial distribution of the light source and the transmit / receive area constraint of the light-receiving path system 20, the size parameters of the through-hole 211 are determined according to the power characteristic parameters. This includes: obtaining the distribution relationship between the power characteristic parameters and the size parameters of the through-hole 211. Based on the preset spatial distribution of the light source, and with the constraint that the light source intensity per unit area corresponding to the first directional boundary and the second directional boundary of the through-hole 211 is the same, the size parameters of the through-hole 211 are calculated and determined based on the distribution relationship.

[0069] In this embodiment, with a fixed total area of ​​the shared transceiver cross section, the output power of the light source increases with the increase of the size parameter of the through-hole 211. The receiving area of ​​the receiving region decreases with the increase of the size parameter of the through-hole 211. By constructing the distribution relationship between the transmission power and the receiving area within the shared transceiver cross section and the power characteristic parameter as a function of the aperture size, the theoretical aperture size for maximizing the transceiver efficiency can be accurately determined. This solves the problem of blind trial and error in traditional coaxial optical paths, and maximizes the maximum detection distance and R&D efficiency of the entire device within a limited volume space.

[0070] Furthermore, by setting the preset spatial distribution of the light source and setting constraints, the complex continuous non-uniform distribution of the light source in space is transformed into a binary linkage relationship of the aperture 211 boundary on different axes. Under the premise of ensuring the accuracy of integral calculation, the initial size parameters of the rectangular or elliptical aperture of the non-uniform radiation characteristics of the light source can be efficiently solved. This ensures that the high-energy region of the emitted beam is maximized while avoiding ineffective blocking of the received echo area, thus achieving the effect of multi-axis size collaborative optimization.

[0071] In some embodiments, combined with Figure 3 As shown, the transmitted beam is located in the center of the mirror, affecting the central region of the received echo cross-section. The transmitting area and receiving area need to be balanced to obtain suitable parameters. The transmitted projection aperture has both square and circular regions. When the total area of ​​the transmitting and receiving regions is... The area of ​​the launch zone is Then the receiving projection area is The optimized ranging dimensions, based on the ranging requirements, should meet the following requirements: ,or This is the maximum value.

[0072] Specifically, consider a circular transmit / receive area with a radius of 4.5 mm, where the emitting area can be square or circular. A light-emitting area is used. A laser diode with fast and slow axes diverging at 22° and 10°, and an emitting lens in the horizontal direction. The focal length is The emitting lens is in the vertical direction The focal length is The light intensity per unit angle follows a Gaussian distribution. Its output power It can be represented as: (2) In the above formula (2), , Angles between two axes and the center angle are represented as follows: , , , The parameter used to represent the divergence angle of two axes.

[0073] Combination Figures 3 to 5 As shown, receiving focal length It needs to be determined based on the field of view of the emitted beam and the photosensitive surface of the receiving detector 122. When the photosensitive surface is... For a square region, in order to achieve better field-of-view matching, it is usually necessary to satisfy the following conditions in a small-angle field of view: The corresponding receiving area is: (3) Combination Figures 6 to 7 As shown, it can be calculated according to the following formula. The curves showing the variation of power characteristic parameters.

[0074] In some embodiments, the distribution relationship between power characteristic parameters and size parameters satisfies: Combination Figure 4 and Figure 6 As shown, through hole 211 is a square through hole with a dimension parameter of half the side length. Under the following conditions: (4) Combination Figure 5 and Figure 7 As shown, through hole 211 is a circular through hole with a radius as its dimensional parameter. Under the following conditions: (5) In the above formulas (4) and (5), Used to indicate the output power of the light source in the light-emitting circuit system 20; Used to represent the effective receiving area of ​​the echo signal of the receiving and receiving optical path system 20; The total radius of the sending and receiving area. The length of half a side of the square through hole. The radius of the circular through hole; and These are the divergence angle parameters in the horizontal and vertical directions, respectively; Used to represent the central light intensity. This embodiment presents a double integral model relation, simplifying the complex three-dimensional spatial ray into deterministic two-dimensional geometric energy algebra operations, reducing the computational load and convergence time of parameter iterative solutions.

[0075] like Figures 6 to 7 As shown, the square through hole is in The maximum value of the power characteristic parameter in the vicinity is A circular through hole in The maximum value of the power characteristic parameter in the vicinity is The maximum values ​​of the two schemes are close, but the optimal aperture parameter values ​​are different for square and circular through holes.

[0076] Furthermore, considering that both the aforementioned square and circular through holes have variable diameters, and both deform in the same direction to form rectangular and elliptical through holes, such as... Figure 8 and Figure 9 As shown. Correspondingly, rectangular and elliptical through-holes are variables, and the power characteristic parameters are... Contour outline map, such as Figure 10 and Figure 11 As shown. Combined with Figures 8 to 11 As shown, the rectangular through hole is in , The maximum value of the corresponding power characteristic parameter is And the oval through hole in , The maximum value of the corresponding power characteristic parameter is .

[0077] In some embodiments, the preset spatial distribution of the light source includes a distribution in which the light source intensity monotonically decreases from the center angle toward the edge. When the light source intensity in the angular spatial distribution monotonically decreases from the center angle toward the edge, the equal intensity per unit area at the boundaries of the first direction (x-direction) and the second direction (y-direction) is the optimized integration condition.

[0078] In some embodiments, the preset spatial distribution of the light source is a Gaussian distribution. However, the spatial distribution of the light source in this application is not limited to a Gaussian distribution. In other embodiments, the spatial distribution of the light source includes distributions with continuously varying angular spatial distributions, such as super-Gaussian distribution, cosine distribution, and uniform distribution.

[0079] In this embodiment, the preset spatial distribution of the light source is a Gaussian distribution. The constraint that the unit area light source intensity corresponding to the first directional boundary and the second directional boundary of the through-hole 211 is the same includes: Given that through hole 211 is a rectangular through hole, constrain the lateral dimension of the rectangular through hole. With longitudinal dimension The following relationship must be satisfied: (6) Given that through hole 211 is an elliptical through hole, constrain the transverse half-axis of the elliptical through hole. With longitudinal half axis The following relationship must be satisfied: (7) In the above formulas (6) and (7), and These are the focal lengths of the emitting lens in the horizontal and vertical directions, respectively. and These are the divergence angle parameters in the horizontal and vertical directions, respectively.

[0080] The calculation results show that the rectangular through hole is in , The maximum value of the corresponding power characteristic parameter is And the oval through hole in , The maximum value of the corresponding power characteristic parameter is The calculation result is consistent with the contour line result calculated by setting both directions as variables.

[0081] For power characteristic parameters The optimization is based on the aforementioned constraints regarding the transmit / receive focal length ratio. , By combining numerical integration of the emitted beam, the relationship between its variation with aperture size and receiving focal length is obtained, such as... Figures 11 to 13 As shown.

[0082] Based on the calculated power characteristic parameters Two-dimensional contour plot of parameter changes, such as Figure 14 and Figure 15 As shown. According to the calculation results, for a rectangular through hole, in , , Under these conditions, the power characteristic parameters approach their extreme values. For an elliptical through-hole, in , , Under these conditions, the power characteristic parameters are close to their extreme values, thus determining the optimal parameter values ​​for the aperture of through-hole 211, such as... Figures 14 to 15 As shown.

[0083] In the above embodiments, the boundary constraints are refined into major and minor axis or horizontal and vertical dimension ratio constraint equations for rectangular and elliptical through holes, so that the geometry of the through holes matches the energy boundary of non-axisymmetric light spots such as Gaussian distribution, thereby compressing the dead area of ​​the receiving surface to the limit while ensuring high emission energy.

[0084] After determining the size parameters of the through hole 211 on the through hole reflector 21, a stray light suppression design process is set up to avoid interference from reflections from internal structural components or the housing 26.

[0085] In some embodiments, the setting states of the first extinction sleeve 23 and the second extinction sleeve 24 are determined by a parameter optimization method. Specifically, if the stray light suppression condition preset in the parameter optimization method indicates that the stray light index exceeds the noise range, it is determined that the first extinction sleeve 23 is set at the through-hole 211. After setting the first extinction sleeve 23 at the through-hole 211, and if the stray light suppression condition indicates that the stray light index still exceeds the noise range, it is determined that the second extinction sleeve 24 is set at the rotating reflector 22. In this embodiment, whether the stray light index exceeds the noise range is used as the criterion to achieve on-demand configuration of the extinction sleeves along the spatial path. When stray light initially exceeds the limit, the first extinction sleeve 23 at the through-hole 211 is precisely triggered to perform first-order suppression. If it still exceeds the limit, the second extinction sleeve 24 at the rotating reflector 22 is cascaded to perform higher-order extinction. This eliminates dynamic scanning stray light while avoiding ineffective obstruction of the effective receiving area by blindly stacking hardware, achieving an effective balance between the system signal-to-noise ratio and detection energy.

[0086] In some embodiments, step S3, determining the geometry of the through-hole 211 and whether to install a first extinction sleeve 23 at the through-hole reflector 21 based on preset stray light suppression conditions, includes: evaluating the amplitude of the stray light signal generated by the receiving and transmitting optical path system 20 based on optical simulation, theoretical calculation, or test verification. Based on the comparison result between the stray light signal amplitude and the detection signal threshold, the geometry of the through-hole 211 and whether to install a first extinction sleeve 23 at the through-hole 211 are determined. In this embodiment, a trade-off mechanism based on the detection signal threshold and the stray light signal amplitude is established, dynamically optimizing the arrangement of the first extinction sleeve 23 according to the actual severity of reflection, thus balancing the degree of stray light suppression and the efficiency of the receiving and transmitting cross-sections.

[0087] In some embodiments, when the stray light suppression condition indicates that the stray light index is within a preset noise range, the geometry of the via 211 is determined to be a polygon, a circle, or an ellipse. The stray light suppression condition can be a preset noise tolerance range used to assess whether the stray light energy leaking in will overwhelm the echo signal reflected from the target. The stray light index can be the stray light signal amplitude evaluated based on optical simulation, theoretical calculation, or test verification. When the stray light suppression condition indicates that the stray light index is within a preset noise range, it means that the stray light signal amplitude is not greater than the detection signal threshold, based on optical simulation, theoretical calculation, or test verification. In this case, the first extinction sleeve 23 is not provided at the via 211, and the geometry of the via 211 is determined to be a polygon, a circle, or an ellipse. In this embodiment, when the stray light signal amplitude does not exceed the detection signal threshold, the first extinction sleeve 23 can be omitted, maximizing the effective cross-section of the receiving lens 121 and accommodating various via 211 shapes such as polygons, circles, ellipses, or rectangles.

[0088] In some embodiments, when the stray light suppression condition indicates that the stray light index exceeds the noise range, a first extinction sleeve 23 is provided at the through-hole 211; and along the optical axis of the light receiving and receiving path system 20, the geometry of the through-hole 211 and the cross-sectional shape of the first extinction sleeve 23 are determined based on the relative positional relationship between the orthographic projection of the first extinction sleeve 23 and the through-hole 211 region of the through-hole 211. The stray light suppression condition indicating that the stray light index exceeds a preset noise range refers to the situation where the stray light signal amplitude is greater than the detection signal threshold, as evaluated based on optical simulation, theoretical calculation, or test verification. In this case, a first extinction sleeve 23 is provided at the through-hole 211. Along the optical axis of the light receiving and receiving path system 20, the geometry of the through-hole 211 and the cross-sectional shape of the first extinction sleeve 23 are determined based on the relative positional relationship between the orthographic projection of the first extinction sleeve 23 and the through-hole 211 region of the through-hole reflector 21. In this embodiment, when the stray light signal amplitude exceeds the detection signal threshold, a first extinction sleeve 23 is configured to isolate and suppress stray light generated by reflection from the edge or structure of the through hole 211, thereby preventing the detector 122 from deteriorating.

[0089] In some embodiments, when the orthographic projection is located within the area of ​​the through-hole 211, the geometry of the through-hole 211 and the cross-sectional shape of the first matting sleeve 23 are both determined to be a square or rectangle. In this embodiment, when the orthographic projection of the first matting sleeve 23 does not exceed the area of ​​the through-hole 211 of the through-hole reflector 21, the cross-sections of the through-hole 211 and the first matting sleeve 23 are uniformly determined to be square or rectangle, so that the wall of the first matting sleeve 23 coincides with the boundary of the through-hole 211, eliminating the projection obstruction area of ​​the first matting sleeve 23 on the received signal, resulting in high receiving efficiency.

[0090] In some embodiments, when the orthographic projection extends beyond the area of ​​the through-hole 211 and obstructs the reflective surface of the through-hole reflector 21, the corresponding cross-sectional shape is selected based on the obstruction area of ​​the candidate cross-sectional shape of the first matting sleeve 23 on the reflective surface, and the geometry of the through-hole 211 is determined to be consistent with the selected cross-sectional shape. When the orthographic projection extends beyond the area of ​​the through-hole 211 and obstructs the reflective surface of the through-hole reflector 21, the obstruction area on the reflective surface is obtained when the cross-sectional shape of the first matting sleeve 23 is circular, elliptical, square, or rectangular. Based on the comparison results of the obtained obstruction areas, the corresponding cross-sectional shape is selected from circular, elliptical, square, or rectangular, and the geometry of the through-hole 211 is determined to be consistent with the selected cross-sectional shape. In this embodiment, in scenarios where the sleeve inevitably obstructs the reflection surface, by comparing the specific obstruction areas generated by different geometric cross-sections, including circular, elliptical, square, and rectangular shapes, the shape with the smallest obstruction area is selected to reduce the cross-sectional loss of the echo signal.

[0091] In some embodiments, determining whether to install a second extinction sleeve 24 at the rotating mirror 22, given that a first extinction sleeve 23 has been installed, includes: after installing the first extinction sleeve 23 at the through-hole 211, and if the stray light suppression condition indicates that the stray light index still exceeds the noise range, determining to install a second extinction sleeve 24 at the rotating mirror 22; and determining that the geometry of the through-hole 211, the cross-sectional shape of the first extinction sleeve 23, and the cross-sectional shape of the second extinction sleeve 24 are all circular. After installing the first extinction sleeve 23 at the through-hole 211, based on optical simulation, theoretical calculation, or test verification evaluation, if the stray light signal amplitude is still greater than the detection signal threshold, installing a second extinction sleeve 24 on the incident light side of the rotating mirror 22. And determining that the cross-sectional shape of the second extinction sleeve 24 is circular. In this embodiment, when the stray light signal amplitude is still greater than the detection signal threshold, a circular second extinction sleeve 24 is added below the through-hole reflector 21 to achieve multi-level reflective shielding and suppress stray light in the system.

[0092] In some embodiments, the parameter optimization method further includes: determining the cross-sectional radius of the second matting sleeve 24, which has a circular cross-sectional shape, based on the geometry of the through hole 211. By aligning the first matting sleeve 23 and the second matting sleeve 24 in three-dimensional space with the active boundary, the gap and light leakage between the upper and lower sleeves are eliminated while ensuring the omnidirectional rotational symmetry of the circular sleeve. Furthermore, by utilizing the omnidirectional rotational symmetry of the circular cross-section, the ineffective gap area formed by the mismatch between the square, rectangular, or elliptical sleeves and the active space boundary during rotation is eliminated, thereby improving the utilization rate of the transceiver aperture during the rotational scanning process.

[0093] Furthermore, the radius of the lower circular rotating sleeve is quantitatively constrained based on the geometric boundary of the upper through-hole 211. In some embodiments, when the geometry of the through-hole 211 is circular, the radius of the second extinction sleeve 24 is the same as the radius of the through-hole 211. By setting the upper and lower parts in a consistent circular configuration, the inner diameter of the second extinction sleeve 24 is aligned with the boundary of the through-hole 211 in the entire circumference, which not only forms a smooth extinction channel but also eliminates the gap leakage area caused by shape mismatch, improving the utilization rate of the transceiver aperture. In some other embodiments, when the geometry of the through-hole 211 is elliptical, the radius of the second extinction sleeve 24 is determined to be the length of the semi-major axis of the ellipse. Setting the radius of the circular rotating sleeve to be equal to the semi-major axis of the ellipse ensures that the spatial envelope of the circular sleeve can enclose the maximum boundary of the elliptical through-hole 211 during dynamic rotation. Under the premise of ensuring no interference and light loss at all angles of the scanning beam, the gap between the circular sleeve and the elliptical boundary in the rotational tangential direction is reduced, improving the stray light shielding effect. In other embodiments, when the geometry of the through-hole 211 is square or rectangular, the radius of the second extinction sleeve 24 is determined to be half the length of the diagonal of the square or rectangular shape. Setting the radius of the circular rotating sleeve to half the length of its diagonal ensures that the inner wall of the circular sleeve forms the outer envelope of the smallest circumcircle of the square or rectangular aperture during rotation. This prevents interference with the beam emitted from the edge of the square or rectangular aperture during omnidirectional scanning and also tightens the radial dimension of the circular sleeve to prevent the outer echo receiving area from being blocked due to an excessively large radius.

[0094] In practical applications of lidar 1, based on noise and the signal amplitude of transmitted and received stray light... Determine the detection signal threshold ,in When the signal amplitude exceeds the signal threshold, the system determines it to be a valid signal. Stray light signals mainly originate from structural components, such as reflections from the inner wall of the sleeve and the outer shell 26. The degree of stray light suppression can be altered by installing sleeves at these two locations, thereby changing the transmission and reception efficiency. When the noise and stray light signal amplitude corresponding to the through-hole 211 of the through-hole reflector 21 do not exceed the threshold, the first extinction sleeve 23 is not required. The through-hole 211 can be square, rectangular, circular, or elliptical, as the transmission and reception efficiencies of these shapes are similar.

[0095] Combination Figure 16 and Figure 17 As shown, when the noise and stray light signal amplitude corresponding to the through-hole 211 of the through-hole reflector 21 exceeds the threshold, and the noise and stray light signal amplitude corresponding to the projection area of ​​the through-hole 211 on the receiving lens 121 by the first extinction sleeve 23 does not exceed the threshold, the circular or elliptical sleeve creates an obstruction area for the received signal, the area of ​​which is... ,or In contrast, square or rectangular sleeves do not create obstruction areas, so square or rectangular through holes 211 and sleeves are preferred in this case.

[0096] Combination Figures 18 to 19 As shown, when the sleeve blocks the projection area of ​​the through-hole 211 onto the receiving lens 121, the noise and stray light signal amplitudes exceed a threshold, while the sleeve completely blocks the lower part of the through-hole reflector 21, the noise and stray light signal amplitudes do not exceed the threshold. The circular or elliptical sleeve then creates an obstruction area for the received signal, the area of ​​which is... ,or A square or rectangular sleeve creates an area that blocks the received signal, the area of ​​which is... ,or In this case, the diameter and sleeve can be selected as circular, oval, square, or rectangular depending on the size of the obstructed area.

[0097] Combination Figures 20 to 21 As shown, when the noise and stray light signal amplitude corresponding to the lower part of the through-hole reflector 21, which is completely blocked by the sleeve, exceeds the threshold, and the first extinction sleeve 23 at the rotating reflector 22 reduces the reflection of the outer shell 26 so that the noise and stray light signal amplitude do not exceed the threshold, since the apertures of the upper reflector sleeve and the lower rotating reflector 22 sleeve need to be aligned and matched, a circular through-hole is preferred, as both sleeves have the same radius, resulting in higher utilization of the transmitting and receiving apertures. The radius of the lower rotating reflector 22 sleeve corresponding to an elliptical hole is the semi-major axis of the ellipse, while the radius of the lower rotating reflector 22 sleeve corresponding to a square or rectangular hole is half the length of its diagonal.

[0098] Combination Figure 22 and Figure 23 As shown, when the lidar 1 uses a circular sleeve, for omnidirectional 360° rotational scanning, due to different scanning angles... The corresponding receiving area areas are different, as shown in Figure 22 and... Figure 23 In the image, the vertical and diagonal shaded areas have different overlapping areas. The larger the overlapping area, the larger the receiving area and the stronger the signal. To optimize the signal intensity fluctuations at different scanning angles, a low-reflectivity black bar can be placed in the vertical direction of the second extinction sleeve 24 of the rotating reflector 22 to reduce the signal intensity variations at different scanning angles.

[0099] Combination Figure 24 As shown, the housing 26 of the lidar 1 not only provides support and protection for the system but is also crucial for the realization of the lidar's optical functions. For a 360° omnidirectional scanning lidar 1, a spherical or cylindrical housing 26 is typically used. When the center o of the reflected beam does not coincide with the center of the sphere of the housing 26 (deviation from h), the scanning angle along the vertical plane... The larger the angle, the greater the angle between the emitted light and the 26° normal of the outer shell. The larger the diameter, the greater the angle at which the scanning and detection light rays, refracted by the translucent outer shell 26, deviate from their original path. The larger the value, the better. In order to reduce the influence of the light-transmitting housing 26 on the optical path, the center point of the rotating reflector 22 of this application and the center of the emitted beam coincides with the center of the spherical light-transmitting housing 26 or is on the axis of the cylindrical housing 26, so that the deflection angle of the light transmitted through the housing 26 is minimized.

[0100] In other embodiments, the form of the reflector aperture 211 is not limited to circular or elliptical, square or rectangular, but includes other shapes formed by polygons and curves. The light source in this application is exemplary and includes edge-emitting lasers, surface-emitting lasers, distributed feedback lasers, and other lasers.

[0101] Based on the above power characteristic parameter analysis and sleeve setting method, the parameter optimization methods mainly include: if the background light noise has no or very little impact on the minimum detectable power of the receiving and transmitting light path system 20, then... As a power characteristic parameter, and as an optimization target for setting the mirror aperture size, if background light noise affects the minimum detectable power of the lidar 1 receiving system, then... The power characteristic parameter serves as the optimization objective for setting the aperture size of the reflector. Based on the spatial angular distribution of the light source, the aperture size relationship in the two directions is constrained by the condition that the intensity per unit area is the same in both the horizontal and vertical directions, and the optimal power characteristic parameter is calculated by integration.

[0102] After determining the dimensional parameters of the through-hole 211 on the through-hole reflector 21, a stray light suppression design process is established to avoid interference from reflections from internal structural components or the housing 26. When the noise and stray light signal amplitude corresponding to the through-hole 211 of the through-hole reflector 21 do not exceed a threshold, the first extinction sleeve 23 is not required. The through-hole 211 can be square, rectangular, circular, or elliptical, and its aperture size is determined based on step 2. When the noise and stray light signal amplitude corresponding to the through-hole 211 of the through-hole reflector 21 exceed a threshold, and the sleeve blocks the through-hole 211 in the projection area of ​​the receiving lens, and the noise and stray light signal amplitude do not exceed the threshold, a square or rectangular through-hole 211 and sleeve are used. When the noise and stray light signal amplitude corresponding to the projection area of ​​the through-hole 211 onto the receiving lens exceeds the threshold, but the noise and stray light signal amplitude corresponding to the lower part of the through-hole reflector 211 does not exceed the threshold, the aperture and sleeve shape are selected based on the size of the blocked area, with the aperture and sleeve shape determined to have the smallest blocked area. When the noise and stray light signal amplitude corresponding to the lower part of the through-hole reflector 211 exceeds the threshold, and a second extinction sleeve 24 is provided at the rotating reflector 22 to reduce the reflection of the outer shell 26, so that the noise and stray light signal amplitude do not exceed the threshold, a circular through-hole 211 and sleeve are selected.

[0103] This application quantifies and standardizes the parameters of the receiving and transmitting light paths, and sets up isolation schemes and light-transmitting shell schemes for the receiving and transmitting light paths. Based on the stray light amplitude, it optimizes the arrangement of the first and second extinction sleeves, and balances the transmission and reception efficiency with the degree of stray light suppression. Under the interdependence and coordination of the system's parameter indicators, it improves the overall ranging performance.

[0104] It should be understood that this application is not limited to the content already described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A method for optimizing parameters of a light receiving and transmitting optical system, characterized by, The light receiving and receiving path system includes a through-hole reflector and a rotating reflector; wherein, the light receiving and receiving path system is used to guide the emitted light beam through the through-hole and transmit it to the rotating reflector, so that the emitted light beam is scanned outward by the rotating reflector; and is used to guide the echo signal reflected from the target to be reflected by the rotating reflector and then by the reflective surface of the through-hole reflector for reception; The parameter optimization method includes: Determine the power characteristic parameters used to characterize the detection capability of the receiving and transmitting optical path system; Based on the preset spatial distribution of the light source and the transmit / receive area constraints of the light-receiving path system, the size parameters of the through hole are determined according to the power characteristic parameters. Based on the preset stray light suppression conditions, the geometry of the through hole is determined, and it is determined whether to install a first matting sleeve at the through hole. If it is determined that the first matting sleeve is installed at the through hole, it is determined whether to install a second matting sleeve at the rotating mirror.

2. The parameter optimization method according to claim 1, characterized in that, The determination of the power characteristic parameters used to characterize the detection capability of the receiving and transmitting optical path system includes: The power characteristic parameters are determined based on the correlation characteristics between the minimum detectable power and internal noise, background light noise, and receiving focal length; wherein, When the minimum detectable power is affected by the internal noise to a greater extent than by the background light and is not related to the receiving focal length, the determined power characteristic parameter is the product of the light source output power and the area of ​​the receiving region. When the minimum detectable power is affected by the background light to a greater extent than by the internal noise and is correlated with the receiving focal length, the determined power characteristic parameter is the product of the light source output power, the area of ​​the receiving region, and the receiving focal length.

3. The parameter optimization method according to claim 1, characterized in that, The determination of the via size parameters based on the preset spatial distribution of the light source and the transmit / receive area constraints of the light-receiving path system, according to the power characteristic parameters, includes: Obtain the distribution relationship between the power characteristic parameters and the size parameters of the through hole; Based on the preset spatial distribution of light sources, and with the constraint that the light source intensity per unit area corresponding to the first directional boundary and the second directional boundary of the through hole is the same, the size parameters of the through hole are calculated and determined based on the distribution relationship.

4. The parameter optimization method according to claim 3, characterized in that, The preset spatial distribution of the light source is a Gaussian distribution; the constraint that the unit area light source intensity corresponding to the first direction boundary and the second direction boundary of the through hole is the same includes: Given that the through hole is a rectangular through hole, constrain the lateral dimension of the rectangular through hole. With longitudinal dimension The following relationship must be satisfied: ;or Under the condition that the through hole is an elliptical through hole, constrain the lateral half-axis of the elliptical through hole. With longitudinal half axis The following relationship must be satisfied: ； in, and These are the focal lengths of the emitting lens in the horizontal and vertical directions, respectively. and These are the divergence angle parameters in the horizontal and vertical directions, respectively.

5. The parameter optimization method according to claim 3, characterized in that, The distribution relationship between the power characteristic parameters and the size parameters satisfies: The through hole is a square through hole with a dimension parameter of half the side length. Under the following conditions: ;or The through hole is a circular through hole with a radius as its dimensional parameter. Under the following conditions: ； in, Used to represent the light source output power of the light-receiving circuit system; Used to represent the effective receiving area of ​​the echo signal of the optical path system; The total radius of the sending and receiving area. The length of half the side of the square through hole. The radius of the circular through hole; and These are the divergence angle parameters in the horizontal and vertical directions, respectively; Used to indicate the central light intensity.

6. The parameter optimization method according to claim 1, characterized in that, The preset spatial distribution of the light source includes a distribution in which the light source intensity monotonically decreases from the center angle towards the edge; and / or The power characteristic parameters are positively correlated with the maximum detection distance of the light-emitting circuit system. and / or The power characteristic parameters are based on the maximum detection range of the optical path system. Constrain the relational expression: ； in, Used to indicate the maximum detection range of the light-emitting circuit system; Used to represent the light source output power of the light-receiving circuit system; Used to represent the target reflectivity of the light-receiving and receiving circuit system; Used to represent the effective receiving area of ​​the echo signal of the optical path system; Used to represent the relative intensity distribution of the emission angle of the light-emitting path system; Used to indicate the receiving efficiency of the receiving lens of the receiving optical path system; Used to indicate the emission efficiency of the emitting lens of the receiving and receiving light path system; Used to indicate the angle between the beam normal of the light-receiving and light-emitting path system and the target surface normal; This is used to represent the minimum detectable power of the light-emitting circuit system.

7. The parameter optimization method according to claim 1, characterized in that, The step of determining the geometry of the through-hole according to preset stray light suppression conditions, and determining whether to install a first extinction sleeve at the through-hole reflector, includes: When the stray light suppression condition indicates that the stray light index is within a preset noise range, the geometry of the via is determined to be a polygon, a circle, or an ellipse. When the stray light suppression condition indicates that the stray light index exceeds the noise range, a first matting sleeve is provided at the through hole; and along the optical axis direction of the light receiving and receiving path system, the geometry of the through hole and the cross-sectional shape of the first matting sleeve are determined according to the relative positional relationship between the orthographic projection of the first matting sleeve and the through hole area of ​​the through hole.

8. The parameter optimization method according to claim 7, characterized in that, When the orthographic projection is located within the through-hole area, the geometry of the through-hole and the cross-sectional shape of the first matting sleeve are both determined to be a square or rectangle that are consistent with each other; When the orthographic projection exceeds the through-hole area and obstructs the reflective surface of the through-hole reflector, the corresponding cross-sectional shape is selected based on the obstruction area of ​​the candidate cross-sectional shape of the first matting sleeve on the reflective surface, and the geometry of the through-hole is determined to be consistent with the selected cross-sectional shape.

9. The parameter optimization method according to claim 7, characterized in that, The step of determining whether to install a second matting sleeve at the rotating mirror, given that the first matting sleeve is already in place, includes: After the first matting sleeve is installed at the through hole, and when the stray light suppression condition indicates that the stray light index still exceeds the noise range, it is determined that the second matting sleeve is installed at the rotating mirror; and the geometry of the through hole, the cross-sectional shape of the first matting sleeve, and the cross-sectional shape of the second matting sleeve are all determined to be circular.

10. The parameter optimization method according to claim 9, characterized in that, The parameter optimization method further includes: determining the cross-sectional radius of the second matting sleeve as a circular cross-section based on the geometry of the through hole; When the geometry of the through hole is circular, the radius of the second matte sleeve is the same as the radius of the through hole; or When the geometry of the through hole is elliptical, the radius of the second matting sleeve is determined to be the length of the semi-major axis of the ellipse; or When the geometry of the through hole is square or rectangular, the radius of the second matting sleeve is determined to be half the length of the diagonal of the square or rectangular shape.

11. A light-emitting circuit system, characterized in that, It includes a through-hole reflector and a rotating reflector; the light receiving and receiving path system is used to guide the emitted light beam through the through-hole and transmit it to the rotating reflector, so that the emitted light beam is scanned outward by the rotating reflector; and is used to guide the echo signal reflected from the target to be reflected by the rotating reflector and then by the reflective surface of the through-hole reflector before being received; The size parameters of the through hole, the setting state of whether the through hole reflector is equipped with the first matting sleeve, and the setting state of whether the rotating reflector is equipped with the second matting sleeve are all determined by the parameter optimization method as described in any one of claims 1 to 10.

12. The light-emitting circuit system according to claim 11, characterized in that, The setting state of the first matte sleeve and the second matte sleeve is determined by the parameter optimization method; wherein, In the parameter optimization method, the preset stray light suppression condition indicates that when the stray light index exceeds the noise range, it is determined that the first extinction sleeve is set at the through hole. After the first matting sleeve is installed at the through hole, and if the stray light suppression condition indicates that the stray light index still exceeds the noise range, it is determined that the second matting sleeve is installed at the rotating mirror.

13. The light-emitting circuit system according to claim 11, characterized in that, The light-receiving path system further includes light-absorbing elements disposed on the inner wall of the second matting sleeve. The distribution position and size of the light-absorbing elements are determined by the difference in receiving area corresponding to different angles during the rotational scanning of the rotating reflector; and / or The light-receiving and light-absorbing path system also includes a light-transmitting outer shell; the center point of the intersection of the rotating reflector and the optical axis of the light-receiving and light-absorbing path system coincides with the geometric center of the outer shell.

14. A lidar, characterized in that, include: A transmitting module, used to generate and emit a light beam; The receiving module is used to detect echo signals; and The light-receiving path system as described in any one of claims 11 to 13 is disposed on the optical path between the transmitting module and the receiving module; wherein the light-receiving path system is used to guide the light beam through the through-hole of the through-hole transmitting mirror and transmit it to the rotating reflector, so as to scan and emit the light beam outward through the rotating reflector; and to guide the echo signal reflected from the target to be reflected sequentially by the rotating reflector and the reflecting surface of the through-hole reflector before being transmitted to the receiving module.

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