Laser radar housing construction method, laser radar, device and computer equipment

Abstract

The present application relates to a method for constructing a laser radar housing, a laser radar, a device, and a computer device. The method comprises: determining, under paraxial conditions, a functional relationship between the horizontal divergence angle of a detection beam emitted by the laser radar and laser radar parameters, wherein the laser radar parameters include the refractive index, center thickness, and inner surface radius of the laser radar housing; determining the refractive index, center thickness, and inner surface radius of the laser radar housing based on the functional relationship and a target value for the horizontal divergence angle; determining a cross-sectional curve function of the outer surface of the laser radar housing based on the refractive index, center thickness, and inner surface radius; and constructing the laser radar housing based on the inner surface radius and the cross-sectional curve function. This method can improve the detection accuracy of the laser radar.

Description

Technical Field

[0001] The present application relates to the field of laser radar technology, and in particular to a laser radar housing construction method, a laser radar, a device and a computer equipment. Background Art

[0002] With the rapid development of artificial intelligence and autonomous driving, LiDAR (LiDAR) has attracted significant attention due to its superior performance, including high ranging accuracy, high angular resolution, and high repetition rate. As a key component of LiDAR, the housing not only supports and protects the radar but also significantly impacts its overall performance and measurement reliability.

[0003] In traditional lidar, the lidar shell adopts a rotationally symmetrical structure such as a cylindrical or hemispherical shell. Since the refractive index of the lidar shell is different from that of air, when the laser beam passes through the lidar shell and emits outward, the lidar shell refracts the laser beam, causing the laser beam to diverge in the horizontal direction, while the laser beam will simultaneously deflect and diverge in the vertical direction. The divergence and deflection of the laser beam will affect the performance of the lidar and reduce the detection accuracy of the lidar. Summary of the Invention

[0004] Based on this, it is necessary to provide a laser radar shell construction method, laser radar, device, computer equipment, computer-readable storage medium and computer program product that can reduce the divergence of the laser beam and eliminate the deflection of the laser beam to address the above technical problems.

[0005] In a first aspect, the present application provides a method for constructing a lidar housing. The method comprises:

[0006] Under paraxial conditions, determining a functional relationship between a horizontal divergence angle of a detection beam emitted by the laser radar and laser radar parameters, wherein the laser radar parameters include a refractive index of a laser radar housing, a center thickness of the laser radar housing, and an inner surface radius of the laser radar housing;

[0007] Determining a refractive index value, a center thickness value, and an inner surface radius value of the laser radar housing according to the functional relationship and the target value of the horizontal divergence angle;

[0008] Determine a cross-sectional curve function of the outer surface of the laser radar housing according to the refractive index value, the center thickness value, and the inner surface radius value, where a curve formed by the intersection of a plane passing through the central axis of the laser radar housing and the outer surface is the cross-sectional curve, and the central axis passes through the center of the inner surface and is perpendicular to the horizontal direction;

[0009] The laser radar shell is constructed according to the inner surface radius value and the cross-sectional curve function.

[0010] In one embodiment, the method further comprises:

[0011] Determining a value range of the horizontal divergence angle according to a preset width and a preset proportional coefficient of the detection beam;

[0012] A target value of the horizontal divergence angle is determined according to a value range of the horizontal divergence angle.

[0013] In one embodiment, determining the cross-sectional curve function of the outer surface of the laser radar housing according to the refractive index value, the center thickness value, and the inner surface radius value includes:

[0014] determining a first optical path according to the refractive index value, the center thickness value, and the inner surface radius value, where the first optical path is an optical path of a first laser beam from the center of the inner surface sphere to a target plane, and the first laser beam is a laser beam emitted from the center of the inner surface sphere in a horizontal direction;

[0015] Determining a second optical path according to the inclination angle, the refractive index value, the center thickness value, and the inner surface radius value, where the second optical path is an optical path of a second laser beam from the central axis to the target plane, the second laser beam is a laser beam emitted from the central axis in a horizontal direction, the target plane is perpendicular to the first laser beam and the second laser beam, respectively, the second laser beam intersects with the inner surface to form an intersection point, a line connecting the intersection point and the center of the inner surface forms a first radius, and an angle between the first radius and the second laser beam is the inclination angle;

[0016] A cross-sectional curve function of the outer surface of the laser radar housing is determined based on the first optical path and the second optical path.

[0017] In one embodiment, determining a cross-sectional curve function of an outer surface of the lidar housing according to the first optical path and the second optical path includes:

[0018] Determining an optical path equation based on the first optical path and the second optical path;

[0019] According to the optical path equation, a plurality of discrete points on the cross-sectional curve are obtained;

[0020] Each of the discrete points is fitted to obtain the cross-sectional curve function.

[0021] In one embodiment, performing fitting processing on each of the discrete points to obtain the cross-sectional curve function includes:

[0022] The least square method is combined with an even-order aspheric curve equation to fit each of the discrete points to obtain the cross-sectional curve function.

[0023] In one embodiment, constructing the laser radar housing according to the inner surface radius value and the cross-sectional curve function includes:

[0024] Determine the inner surface according to the inner surface center and the inner surface radius;

[0025] determining the cross-sectional curve according to the cross-sectional curve function;

[0026] The cross-sectional curve is rotated with the central axis as the rotation axis to obtain the outer surface;

[0027] The laser radar housing is constructed according to the inner surface and the outer surface.

[0028] In a second aspect, the present application further provides a laser radar. The laser radar housing of the laser radar includes an inner surface and an outer surface; wherein,

[0029] The inner surface radius value of the inner surface is a numerical value determined by a functional relationship and a target value of the horizontal divergence angle, wherein the functional relationship is a functional relationship between the horizontal divergence angle of the detection light beam emitted by the laser radar and laser radar parameters determined under a paraxial condition, and the laser radar parameters include the refractive index of the laser radar housing, the center thickness of the laser radar housing, and the inner surface radius;

[0030] The cross-sectional curve function of the outer surface is a function determined by the refractive index value, the center thickness value, and the inner surface radius value.

[0031] In one embodiment, the laser radar further includes: a plane reflector, a transmitting lens and a laser light source; wherein,

[0032] The laser light source is used to emit a laser beam, and the laser beam passes through the emitting lens and the plane reflector in sequence and then emerges in a horizontal direction;

[0033] The laser light source is located at the focal plane of the emitting lens, the long side of the emitting lens is located in the fast axis direction of the laser beam, the short side of the emitting lens is located in the slow axis direction of the laser beam, and the long side direction of the emitting lens is perpendicular to the front detection direction of the laser radar;

[0034] The distance from the intersection of the plane reflector and the central axis to the center of the inner surface is the sum of the distance from the laser light source to the central axis, 1 / 2 of the short side of the emitting lens, and the assembly margin.

[0035] In a third aspect, the present application also provides a device for constructing a lidar housing. The device comprises:

[0036] A first determination module is configured to determine, under a paraxial condition, a functional relationship between a horizontal divergence angle of a detection beam emitted by the laser radar and laser radar parameters, wherein the laser radar parameters include a refractive index of a laser radar housing, a center thickness of the laser radar housing, and an inner surface radius of the laser radar housing;

[0037] A second determination module is configured to determine a refractive index value, a center thickness value, and an inner surface radius value of the laser radar housing according to the functional relationship and the target value of the horizontal divergence angle;

[0038] a third determining module, configured to determine a cross-sectional curve function of the outer surface of the laser radar housing according to the refractive index value, the center thickness value, and the inner surface radius value, wherein a curve formed by the intersection of a plane passing through a central axis of the laser radar housing and the outer surface is the cross-sectional curve, and the central axis passes through the center of the inner surface and is perpendicular to the horizontal direction;

[0039] A construction module is used to construct the laser radar shell according to the inner surface radius value and the cross-sectional curve function.

[0040] In one embodiment, the apparatus further comprises:

[0041] a fourth determining module, configured to determine a value range of the horizontal divergence angle according to a preset width and a preset proportional coefficient of the detection beam;

[0042] The fifth determining module is configured to determine a target value of the horizontal divergence angle according to a value range of the horizontal divergence angle.

[0043] In one embodiment, the third determining module is further configured to:

[0044] determining a first optical path according to the refractive index value, the center thickness value, and the inner surface radius value, where the first optical path is an optical path of a first laser beam from the center of the inner surface sphere to a target plane, and the first laser beam is a laser beam emitted from the center of the inner surface sphere in a horizontal direction;

[0045] Determining a second optical path according to the inclination angle, the refractive index value, the center thickness value, and the inner surface radius value, where the second optical path is an optical path of a second laser beam from the central axis to the target plane, the second laser beam is a laser beam emitted from the central axis in a horizontal direction, the target plane is perpendicular to the first laser beam and the second laser beam, respectively, the second laser beam intersects with the inner surface to form an intersection point, a line connecting the intersection point and the center of the inner surface forms a first radius, and an angle between the first radius and the second laser beam is the inclination angle;

[0046] A cross-sectional curve function of the outer surface of the laser radar housing is determined based on the first optical path and the second optical path.

[0047] In one embodiment, the third determining module is further configured to:

[0048] Determining an optical path equation based on the first optical path and the second optical path;

[0049] According to the optical path equation, a plurality of discrete points on the cross-sectional curve are obtained;

[0050] Each of the discrete points is fitted to obtain the cross-sectional curve function.

[0051] In one embodiment, the third determining module is further configured to:

[0052] The least square method is combined with an even-order aspheric curve equation to fit each of the discrete points to obtain the cross-sectional curve function.

[0053] In one embodiment, the building block is further configured to:

[0054] Determine the inner surface according to the inner surface center and the inner surface radius;

[0055] determining the cross-sectional curve according to the cross-sectional curve function;

[0056] The cross-sectional curve is rotated with the central axis as the rotation axis to obtain the outer surface;

[0057] The laser radar housing is constructed according to the inner surface and the outer surface.

[0058] In a fourth aspect, the present application further provides a computer device. The computer device includes a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the following steps are implemented:

[0059] Under paraxial conditions, determining a functional relationship between a horizontal divergence angle of a detection beam emitted by the laser radar and laser radar parameters, wherein the laser radar parameters include a refractive index of a laser radar housing, a center thickness of the laser radar housing, and an inner surface radius of the laser radar housing;

[0060] Determining a refractive index value, a center thickness value, and an inner surface radius value of the laser radar housing according to the functional relationship and the target value of the horizontal divergence angle;

[0061] Determine a cross-sectional curve function of the outer surface of the laser radar housing according to the refractive index value, the center thickness value, and the inner surface radius value, where a curve formed by the intersection of a plane passing through the central axis of the laser radar housing and the outer surface is the cross-sectional curve, and the central axis passes through the center of the inner surface and is perpendicular to the horizontal direction;

[0062] The laser radar shell is constructed according to the inner surface radius value and the cross-sectional curve function.

[0063] In a fifth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the following steps:

[0064] Under paraxial conditions, determining a functional relationship between a horizontal divergence angle of a detection beam emitted by the laser radar and laser radar parameters, wherein the laser radar parameters include a refractive index of a laser radar housing, a center thickness of the laser radar housing, and an inner surface radius of the laser radar housing;

[0065] Determining a refractive index value, a center thickness value, and an inner surface radius value of the laser radar housing according to the functional relationship and the target value of the horizontal divergence angle;

[0066] Determine a cross-sectional curve function of the outer surface of the laser radar housing according to the refractive index value, the center thickness value, and the inner surface radius value, where a curve formed by the intersection of a plane passing through the central axis of the laser radar housing and the outer surface is the cross-sectional curve, and the central axis passes through the center of the inner surface and is perpendicular to the horizontal direction;

[0067] The laser radar shell is constructed according to the inner surface radius value and the cross-sectional curve function.

[0068] In a sixth aspect, the present application further provides a computer program product. The computer program product includes a computer program that, when executed by a processor, implements the following steps:

[0069] Under paraxial conditions, determining a functional relationship between a horizontal divergence angle of a detection beam emitted by the laser radar and laser radar parameters, wherein the laser radar parameters include a refractive index of a laser radar housing, a center thickness of the laser radar housing, and an inner surface radius of the laser radar housing;

[0070] Determining a refractive index value, a center thickness value, and an inner surface radius value of the laser radar housing according to the functional relationship and the target value of the horizontal divergence angle;

[0071] Determine a cross-sectional curve function of the outer surface of the laser radar housing according to the refractive index value, the center thickness value, and the inner surface radius value, where a curve formed by the intersection of a plane passing through the central axis of the laser radar housing and the outer surface is the cross-sectional curve, and the central axis passes through the center of the inner surface and is perpendicular to the horizontal direction;

[0072] The laser radar shell is constructed according to the inner surface radius value and the cross-sectional curve function.

[0073] The above-mentioned laser radar shell construction method, laser radar, device, computer equipment, storage medium and computer program product can determine the functional relationship between the horizontal divergence angle of the detection light beam emitted by the laser radar and the laser radar parameters under paraxial conditions, wherein the laser radar parameters include the refractive index of the laser radar shell, the center thickness of the laser radar shell and the inner surface radius of the laser radar shell, and determine the refractive index value, center thickness value and inner surface radius value of the laser radar shell based on the functional relationship and the target value of the horizontal divergence angle. The method can also determine the cross-sectional curve function of the outer surface of the laser radar shell based on the refractive index value, center thickness value and inner surface radius value, wherein the curve formed by the intersection of the plane passing through the central axis of the laser radar shell and the outer surface is the cross-sectional curve, the central axis passes through the center of the inner surface and is perpendicular to the horizontal direction, and the laser radar shell is constructed based on the inner surface radius value and the cross-sectional curve function. Based on the above-mentioned laser radar shell construction method, laser radar, device, computer equipment, storage medium and computer program product, the paraxial ray tracing method can be used to determine the functional relationship between the horizontal divergence angle of the detection light beam and the laser radar parameters, and the refractive index value, center thickness value and inner surface radius value in the laser radar parameters can be determined through the functional relationship and the horizontal divergence angle target value, so as to control the horizontal divergence angle within a certain range to reduce the divergence of the detection light beam. The cross-sectional curve function of the outer surface of the laser radar shell can also be determined through the refractive index value, center thickness value and inner surface radius value. By changing the shape of the outer surface, the deflection caused by the refraction of the detection light beam through the laser radar shell can be eliminated, thereby ultimately achieving the purpose of improving the detection accuracy and performance of the laser radar. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] Figure 11 is a flow chart of a method for constructing a lidar housing according to one embodiment;

[0075] Figure 2a and Figure 2b Schematic diagram of the optical path of a detection beam emitted by a laser radar in the prior art;

[0076] Figure 3a 、 Figure 3b and Figure 3c Schematic diagram of the optical path of a detection beam emitted by a laser radar in one embodiment;

[0077] Figure 4 A schematic flow chart of a method for constructing a lidar housing according to another embodiment;

[0078] Figure 5 A schematic flow chart of a method for constructing a lidar housing according to another embodiment;

[0079] Figure 6 A schematic diagram of the optical path of a laser beam inside a laser radar in another embodiment;

[0080] Figure 7 A schematic flow chart of a method for constructing a lidar housing according to another embodiment;

[0081] Figure 8 A schematic flow chart of a method for constructing a lidar housing according to another embodiment;

[0082] Figure 9 Schematic diagram of the structure of a laser radar in one embodiment;

[0083] Figure 10 A schematic diagram of simulation experiment results in one embodiment;

[0084] Figure 11 Schematic diagram of the structure of a laser light source and an emission lens in one embodiment;

[0085] Figure 12 A schematic diagram of the structure of a laser radar housing construction device in one embodiment;

[0086] Figure 13 FIG. 1 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0087] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0088] In one embodiment, Figure 1As shown, a method for constructing a lidar housing is provided. This embodiment uses the method applied to a terminal as an example for illustration. It is understandable that the method can also be applied to a server, or to a system including a terminal and a server, and implemented through the interaction between the terminal and the server. In this embodiment, the method includes the following steps:

[0089] Step 102, under paraxial conditions, determine the functional relationship between the horizontal divergence angle of the detection light beam emitted by the laser radar and the laser radar parameters, wherein the laser radar parameters include the refractive index of the laser radar shell, the center thickness of the laser radar shell and the inner surface radius of the laser radar shell.

[0090] In the embodiment of the present application, the interior of the laser radar contains a laser emission optical path. The laser light source in the laser emission optical path generates and emits a laser beam. The laser beam is transmitted in the laser emission optical path and eventually passes through the laser radar housing in a horizontal direction (parallel to the horizon) into the air to detect the surrounding environment of the laser radar. Among them, the laser beam that enters the air through the laser radar housing is the detection beam emitted by the laser radar, and the transmission direction of the detection beam is horizontal. The laser radar housing is a shell with a certain thickness, including an inner surface and an outer surface, wherein the inner surface is spherical and the outer surface is a rotationally symmetrical curved surface, and its rotational symmetry axis passes through the center of the inner surface.

[0091] In the prior art, referring to Figure 2a As shown in the figure, since the refractive index of the laser radar shell is different from that of the air, the laser beam will be refracted at the inner and outer surfaces of the laser radar shell when it passes through the laser radar shell and enters the air, which will eventually cause the detection beam to diverge in the horizontal direction and deflect and diverge in the vertical direction.

[0092] In the embodiments of this application, under paraxial conditions, light can be considered to propagate in the paraxial region, and the propagation of light can be calculated or derived using the ray propagation formula in paraxial optics, thereby simplifying the complex propagation of light. In this embodiment, under paraxial conditions, the propagation process of the laser beam through the lidar housing is derived to approximately calculate the functional relationship between the horizontal divergence angle of the detection beam emitted by the lidar and the lidar parameters.

[0093] The derivation process of the functional relationship is as follows, refer to Figure 3a As shown, after the laser beam emitted by the laser light source E in the laser radar passes through the emitting lens 302, the short side width of the laser beam is S x , the long side width of the laser beam is S y , and then the laser beam will be reflected by the plane reflector 304 and illuminate the laser radar housing in the horizontal direction. Figure 3bAs shown, the lidar housing can be regarded as a lens with a thickness of d and a width of S. y The laser beam is irradiated on a lens with a thickness of d. The sign rule in geometric optics stipulates that the radius from left to right is positive and from right to left is negative, and the radius is from the vertex of the sphere to the center of the sphere. In this lens, the direction from the vertex of the lens to the center of the sphere is from right to left. Then, in geometric optics, the front surface radius of the lens can be expressed as -R2, and the back surface radius can be expressed as -(R2+d). According to the focal length formula of the thick lens, the focal length of the lens can be obtained as Among them, the focal length F h If it is a negative value, it means that the lens is a concave lens, which will cause the laser beam to diverge. Secondly, the width is S y The laser beam is irradiated to the focal length F h On the lens, it can be regarded as a parallel to the lens with a height of The light is irradiated onto the lens. The angle at which the light diverges after passing through the lens is the horizontal divergence angle of the laser beam. According to geometric optics: light parallel to the optical axis of the lens is incident on the lens, and the reverse extension line of the outgoing light intersects the focus of the lens. The horizontal divergence angle of the laser beam can be expressed as

[0094] In the embodiment of the present application, the process of determining the functional relationship between the horizontal divergence angle of the detection beam emitted by the laser radar and the laser radar parameters can refer to the following formula (1):

[0095]

[0096] Among them, S y represents the long side width of the laser beam, n represents the refractive index of the lidar housing, d represents the center thickness of the lidar housing, and R2 represents the inner radius of the lidar housing. Lidar parameters include the refractive index, center thickness, and inner radius of the lidar housing.

[0097] It should be noted that the above-mentioned process of determining the functional relationship between the horizontal divergence angle of the detection beam emitted by the laser radar and the laser radar parameters is only an example in the embodiment of the present application. The embodiment of the present application does not specifically limit the process of determining the functional relationship between the horizontal divergence angle of the detection beam emitted by the laser radar and the laser radar parameters.

[0098] In the embodiment of the present application, the center thickness of the laser radar housing is the thickness of the upper edge of the laser radar housing, such as Figure 3cAs shown, the intersection of the X-axis and the laser radar shell is the upper edge of the laser radar shell. The thickness of the upper edge of the laser radar shell is approximately regarded as the thickness of the laser radar shell. The laser beam is an elliptical beam, so the laser beam has a long side width and a short side width. The laser radar parameters can also include the long side width of the laser beam.

[0099] Step 104: Determine the refractive index value, center thickness value, and inner surface radius value of the laser radar housing based on the functional relationship and the target value of the horizontal divergence angle.

[0100] In the embodiment of the present application, the above-mentioned functional relationship represents: the relationship between the horizontal divergence angle and the refractive index, center thickness, inner surface radius, and long side width of the laser radar shell, wherein the long side width of the laser beam is determined according to the laser light source and the transmitting lens, and is a known parameter of the laser radar. Therefore, a target value of the horizontal divergence angle can be preset according to the actual detection accuracy requirements of the laser radar, and the specific values of the refractive index, center thickness and inner surface radius can be determined based on the functional relationship and the target value of the horizontal divergence angle, that is, the refractive index value, center thickness value and inner surface radius value of the laser radar shell are determined.

[0101] For example, the functional relationship is The target value of the horizontal divergence angle is 0.5°, and the long side width value of the laser beam is known. First, because the refractive index value is determined by the material of the laser radar shell, a corresponding refractive index value can be selected from the commonly used materials of the laser radar shell in actual applications. In addition, the laser radar shell is affected by the manufacturing process during the remanufacturing process. The laser radar shell has several commonly used center thickness values, from which a center thickness value is selected. Secondly, the target value of the horizontal divergence angle of 0.5°, the long side width value, the refractive index value, and the center thickness value can be substituted into the function relationship to calculate the inner surface radius value.

[0102] Step 106, determine the cross-sectional curve function of the outer surface of the laser radar housing based on the refractive index value, the center thickness value and the inner surface radius value. The curve formed by the intersection of the plane passing through the center axis of the laser radar housing and the outer surface is the cross-sectional curve. The center axis passes through the center of the inner surface and is perpendicular to the horizontal direction.

[0103] like Figure 2b As shown, in the prior art, because the refractive index of the laser radar housing is different from that of air, the detection beam formed by the laser beam passing through the laser radar housing will produce a vertical deflection, affecting the detection accuracy of the laser radar.

[0104] In an embodiment of the present application, the Fermat principle can be used, and based on known laser radar parameters, the surface equation of the outer surface of the laser radar housing can be determined. The outer surface of the laser radar housing obtained according to the above method is compared with the spherical outer surface of the existing laser radar housing. The detection light beam emitted from the laser radar housing in the embodiment of the present application to the outside world will not be deflected or diverged in the vertical direction.

[0105] In an embodiment of the present application, the inner surface radius value has been determined in the above steps, that is, the inner surface of the laser radar shell has been determined, and the refractive index and center thickness have also been determined. Then, the refractive index value, center thickness value and inner surface radius value can be processed using the principles of geometric optics to determine the cross-sectional curve function of the outer surface of the laser radar shell. When the outer surface of the laser radar shell conforms to the cross-sectional curve function, the transmission direction of the detection beam formed by the laser beam passing through the laser radar shell is still horizontal, eliminating the vertical deflection of the detection beam.

[0106] Among them, the straight line passing through the center of the inner surface and perpendicular to the horizontal direction is the straight line where the central axis is located. The center of the inner surface is on the central axis. The central axis is the rotational symmetry axis of the inner and outer surfaces of the laser radar shell. The curve where the plane where the central axis is located intersects with the outer surface of the laser radar shell is the cross-sectional curve. The outer surface of the laser radar shell can be obtained by rotating the cross-sectional curve around the central axis.

[0107] Step 108: construct the laser radar shell according to the inner surface radius value and the cross-sectional curve function.

[0108] In an embodiment of the present application, the shape of the inner surface of the laser radar housing can be determined based on the inner surface radius, and a cross-sectional curve can be determined based on the cross-sectional curve function. By rotating the cross-sectional curve around the central axis, the shape of the outer surface of the laser radar housing can be determined. The laser radar housing can be constructed through the inner surface shape and the outer surface shape.

[0109] In the above-mentioned method for constructing a laser radar shell, the functional relationship between the horizontal divergence angle of the detection light beam and the laser radar parameters can be determined under near-axis conditions, and the refractive index value, center thickness value and inner surface radius value in the laser radar parameters can be determined through the functional relationship and the target value of the horizontal divergence angle, so as to control the horizontal divergence angle within a certain range to reduce the divergence of the detection light beam. The cross-sectional curve function of the outer surface of the laser radar shell can also be determined through the refractive index value, center thickness value and inner surface radius value. By changing the shape of the outer surface, the deflection caused by the refraction of the detection light beam through the laser radar shell can be eliminated, thereby ultimately achieving the purpose of improving the detection accuracy and performance of the laser radar.

[0110] In one embodiment, Figure 4 As shown, the method further includes:

[0111] Step 402: Determine the range of the horizontal divergence angle according to the preset width and the preset proportional coefficient of the detection light beam.

[0112] In the embodiment of the present application, the detection beam emitted from the laser radar housing has a certain width. The width of the detection beam is related to the horizontal divergence angle of the laser beam. The larger the horizontal divergence angle, the larger the width of the detection beam. Therefore, according to the detection accuracy requirements of the laser radar in the actual application process, a preset width of the detection beam can be generated, and a preset proportional coefficient can be generated to determine the value range of the horizontal divergence angle. For example, if the preset width of the detection beam is 5 and the preset proportional coefficient is 1 / 10, the value range of the horizontal divergence angle can be obtained as follows:

[0113] Step 404: Determine a target value of the horizontal divergence angle according to the value range of the horizontal divergence angle.

[0114] In the embodiment of the present application, the maximum value in the value range of the horizontal divergence angle is used as the target value of the horizontal divergence angle. In actual applications, any value that satisfies the value range of the horizontal divergence angle can also be taken as the target value of the horizontal divergence angle. In the embodiment of the present application, there is no specific limitation on how to determine the target value of the horizontal divergence angle. The target value of the horizontal divergence angle only needs to satisfy the value range of the horizontal divergence angle.

[0115] In this embodiment, the preset width and preset proportional coefficient of the detection beam can be flexibly adjusted according to the detection accuracy requirements of the laser radar. The value range of the horizontal divergence angle is determined by the preset width and preset proportional coefficient, and the target value of the horizontal divergence angle is determined based on the value range of the horizontal divergence angle. This can ensure that the horizontal divergence angle of the detection beam is controlled within a certain range, thereby reducing the impact of the divergence of the detection beam on the detection accuracy of the laser radar.

[0116] In one embodiment, Figure 5 As shown, step 106 includes:

[0117] Step 502, determine the first optical path based on the refractive index value, the center thickness value and the inner surface radius value. The first optical path is the optical path of the first laser beam from the inner surface center to the target plane. The first laser beam is a laser beam emitted from the inner surface center in a horizontal direction.

[0118] In the present application, refer to Figure 6As shown, the first laser beam is emitted horizontally from the center O of the inner surface sphere. The first laser beam passes through the line segments OA and AB from the center O of the inner surface sphere to the point C of the target plane. The first optical path is the optical path of the first laser beam from the center of the inner surface sphere to the target plane. The first optical path is: R2+nd, where R2 represents the inner surface radius, n represents the refractive index, and d represents the center thickness. Therefore, the first optical path can be determined based on the refractive index value, the center thickness value, and the inner surface radius value.

[0119] Step 504: Determine a second optical path based on the tilt angle, refractive index, center thickness, and inner surface radius. The second optical path is the optical path of the second laser beam from the central axis to the target plane. The second laser beam is a laser beam emitted from the central axis in a horizontal direction. The target plane is perpendicular to the first laser beam and the second laser beam, respectively. The second laser beam intersects with the inner surface to form an intersection point. The line connecting the intersection point and the center of the inner surface forms a first radius. The angle between the first radius and the second laser beam is the tilt angle.

[0120] In the embodiment of this application, Figure 6 As shown in the figure, the second laser beam is emitted horizontally from point Oˊ on the central axis. The second laser beam passes through the line segments OˊAˊ, AˊBˊ, and BˊCˊ from the central axis to point Cˊ on the target plane. The second optical path is the optical path of the second laser beam from the central axis to the target plane. The second optical path can be expressed as: R2cosθ+n L(θ)+R2+d-R2cosθ-L(θ)cos(θ-θ′), where θ represents the tilt angle. The second laser beam intersects the inner surface at point Aˊ. The angle between the straight line OˊAˊ and the straight line OAˊ is the tilt angle θ. L(θ) is the distance the second laser beam travels in the laser radar housing, and θ′ is the emission angle of the second laser beam on the inner surface of the laser radar.

[0121] Step 506: Determine a cross-sectional curve function of the outer surface of the laser radar housing based on the first optical path and the second optical path.

[0122] In an embodiment of the present application, according to the principle of equal optical paths, the first optical path and the second optical path are made equal, and an equation can be obtained. According to the law of refraction of light nsinθ′=sinθ, the above equation is simplified and calculated to obtain the cross-sectional curve function of the outer surface of the laser radar housing.

[0123] In an embodiment of the present application, the cross-sectional curve function of the outer surface of the laser radar housing is determined based on the refractive index value, the center thickness value and the inner surface radius value. That is, by changing the shape of the outer surface, the deflection caused by the refraction of the detection light beam through the laser radar housing is eliminated, thereby ultimately achieving the purpose of improving the detection accuracy and performance of the laser radar.

[0124] In one embodiment, Figure 7As shown, step 506 includes:

[0125] Step 702: Determine an optical path equation based on the first optical path and the second optical path.

[0126] In the embodiment of the present application, the first optical path is made equal to the second optical path, and the optical path equation can be determined. That is, according to the first optical path obtained in the previous steps: R2+nd, and the second optical path: R2cosθ+n L(θ)+R2+d-R2cosθ-L(θ)cos(θ-θ′), the optical path equation R2+nd=R2cosθ+n L(θ)+R2+d-R2cosθ-L(θ)cos(θ-θ′) can be obtained.

[0127] Among them, such as Figure 6 As shown, let the first optical path be equal to the second optical path, that is, the distance transmitted by the first laser beam from point O to point Cˊ is equal to the distance transmitted by the second laser beam from point Oˊ to point Cˊ. At this time, the detection beam is still emitted in the horizontal direction, eliminating the vertical deflection of the detection beam.

[0128] Step 704: Obtain multiple discrete points on the cross-sectional curve according to the optical path equation.

[0129] In the embodiment of the present application, the law of refraction of light nsinθ′=sinθ can be substituted into the optical path equation obtained above, and the optical path equation can be simplified and calculated to obtain the initial function of the cross-sectional curve. The above process of determining the initial function of the cross-sectional curve can be expressed by the following formula (II):

[0130]

[0131] Where x(θ) represents the x-coordinate of a point on the cross-sectional curve, and z(θ) represents the z-coordinate of a point on the cross-sectional curve.

[0132] It should be noted that the above process of determining the initial function of the cross-sectional curve is only an example in the embodiment of the present application, and the process of determining the initial function of the cross-sectional curve is not specifically limited in the embodiment of the present application.

[0133] In the embodiment of the present application, multiple discrete points on the cross-sectional curve can be determined based on the initial function of the cross-sectional curve (Formula (II)). For example, three inclination angles are first determined: 15°, 30°, and 45°. The inner surface radius R2, refractive index n, and center thickness d in Formula (II) are all known. Substituting the inclination angles into Formula (II) respectively, discrete points (x(15°), z(15°)), (x(30°), z(30°)), and (x(45°), z(45°)) are obtained respectively.

[0134] Step 706: Fit each discrete point to obtain a cross-sectional curve function.

[0135] In the embodiment of the present application, each discrete point is fitted according to its coordinates to obtain a fitting curve function, which is the cross-sectional curve function.

[0136] In one embodiment, step 706 includes:

[0137] The least square method combined with the even-order aspheric curve equation is used to fit each discrete point to obtain the cross-sectional curve function.

[0138] In the embodiment of the present application, when fitting each discrete point to obtain the cross-sectional curve function, the even-order aspheric curve function (Formula (3)) of the following standard equation can be used:

[0139]

[0140] The above formula (3) is Taylor expanded, and the coefficients of the standard equation after Taylor expansion are compared with the coefficients of the fitting relationship. Then, the parameters of the even-order aspheric equation are obtained by linear least squares fitting of each discrete point, thereby determining the cross-sectional curve function.

[0141] For example, still taking the above example, Formula (3) is Taylor expanded, and the coefficients of the standard equation after Taylor expansion and the fitting relationship (i.e., a4, a6, a8...) are compared. Then, the parameters of the even-order aspheric equation are obtained by linear least squares fitting of each discrete point (x(15°), z(15°)), (x(30°), z(30°)), (x(45°), z(45°)), thereby determining the cross-sectional shape curve of the light-transmitting shell.

[0142] In an embodiment of the present application, the paraxial ray tracing method can be used to determine the functional relationship between the horizontal divergence angle of the detection light beam and the laser radar parameters, and the refractive index value, center thickness value and inner surface radius value in the laser radar parameters can be determined through the functional relationship and the target value of the horizontal divergence angle, so as to control the horizontal divergence angle within a certain range to reduce the divergence of the detection light beam. The cross-sectional curve function of the outer surface of the laser radar housing can also be determined through the refractive index value, center thickness value and inner surface radius value. By changing the shape of the outer surface, the deflection caused by the refraction of the detection light beam through the laser radar housing can be eliminated, thereby ultimately achieving the purpose of improving the detection accuracy and performance of the laser radar.

[0143] In one embodiment, Figure 8 As shown, step 108 includes:

[0144] Step 802: Determine the inner surface according to the inner surface center and the inner surface radius.

[0145] In an embodiment of the present application, the position of the center of the inner surface is first determined, and the center of the inner surface is used as the center of the sphere, and the inner surface radius value is used as the radius, so as to determine the spherical shape of the inner surface. Secondly, according to the known size parameters of the laser radar, the spherical shape of the inner surface is intercepted to obtain the inner surface of the laser radar shell.

[0146] Step 804: Determine the cross-sectional curve according to the cross-sectional curve function.

[0147] In an embodiment of the present application, modeling software can be used to determine the curve shape of the cross-sectional curve based on the cross-sectional curve function, wherein the coordinate axis where the cross-sectional curve function is located is determined to be the coordinate axis with the center axis as the z-axis and the straight line perpendicular to the z-axis as the x-axis.

[0148] Step 806 , rotating the cross-sectional curve with the central axis as the rotation axis to obtain the outer surface.

[0149] In the embodiment of the present application, the central axis is used as the rotation axis, and the cross-sectional curve is rotated around the central axis once (i.e., 360°) to obtain the curved surface shape of the outer surface.

[0150] Step 808: construct a lidar housing based on the inner surface and the outer surface.

[0151] In an embodiment of the present application, the inner surface and the outer surface are combined to construct a laser radar housing. During the assembly process, the center of the inner surface is placed on the central axis, and the center of the inner surface coincides with the origin of the coordinate axis of the interface curve function of the outer surface.

[0152] In an embodiment of the present application, a paraxial ray tracing method is used to determine the functional relationship between the horizontal divergence angle of the detection light beam and the laser radar parameters, and the refractive index value, center thickness value and inner surface radius value in the laser radar parameters are determined through the functional relationship and the target value of the horizontal divergence angle, so as to control the horizontal divergence angle within a certain range to reduce the divergence of the detection light beam. The cross-sectional curve function of the outer surface of the laser radar housing can also be determined through the refractive index value, center thickness value and inner surface radius value. By changing the shape of the outer surface, the deflection caused by the refraction of the detection light beam through the laser radar housing can be eliminated, thereby ultimately achieving the purpose of improving the detection accuracy and performance of the laser radar.

[0153] In an exemplary embodiment, the structure of the laser radar is as follows Figure 9 As shown, first, under the paraxial condition, the functional relationship between the horizontal divergence angle of the detection beam emitted by the lidar and the lidar parameters can be determined. According to the detection needs of the laser radar, the preset width of the detection beam is 5 and the preset proportional coefficient is 1 / 10, then the range of the horizontal divergence angle can be obtained as follows: The maximum value 0.5 in the value range of the horizontal divergence angle is used as the target value of the horizontal divergence angle.

[0154] Secondly, according to the functional relationship and the target value of the horizontal divergence angle, the process of determining the refractive index value, center thickness value and inner surface radius value of the laser radar shell is as follows: the long side width S of the laser beam y The value of is known. We can select a corresponding refractive index value from the commonly used materials of the lidar shell in actual applications, and select a center thickness value from the commonly used center thickness values. Substitute the target value of the horizontal divergence angle 0.5°, the long side width value, the refractive index value, and the center thickness value into the function relationship to calculate the inner surface radius value.

[0155] Afterwards, the first optical path can be determined based on the refractive index value, the center thickness value, and the inner surface radius value. The second optical path can be determined based on the inclination angle, the refractive index value, the center thickness value, and the inner surface radius value. Based on the first optical path and the second optical path, the optical path equation is determined: R2+nd=R2cosθ+nL(θ)+R2+d-R2cosθ-L(θ)cos(θ-θ′). Substituting the law of refraction of light nsinθ′=sinθ into the optical path equation and simplifying the optical path equation, the initial function of the cross-sectional curve can be obtained:

[0156]

[0157] To simplify the calculation process, the optical laws in paraxial optics can be substituted into the initial function of the above cross-sectional curve, where in the paraxial region θ satisfies: The relationship of the curvature radius near the paraxial direction can be obtained:

[0158]

[0159] According to the above curvature radius relationship function, the curvature radius at the vertex B of the cross-section curve can be obtained as From the perspective of paraxial optics, in order to prevent the light incident parallel to the optical axis from being deflected after passing through a meniscus lens with an inner diameter of R2, a center thickness of d, and an outer diameter of R1, the focal length of the meniscus lens must be infinite. According to the formula for the focal length of a thick lens, Available This result is consistent with the curvature radius result at the vertex B obtained according to the above principle of equal optical path, which verifies the correctness of the initial function of the cross-sectional curve obtained according to the above principle of equal optical path.

[0160] Determine three tilt angles: 15°, 30°, and 45°, and determine the coordinates of the discrete points corresponding to the three tilt angles (x(15°), z(15°)), (x(30°), z(30°)), and (x(45°), z(45°)). Use the even aspheric curve function to calculate the coordinates of the discrete points. The fitting process for the above three discrete points is as follows:

[0161] The even-order aspheric curve function is Taylor expanded, and the coefficients of the standard equation after Taylor expansion are compared with the fitting relationship (i.e., a4, a6, a8...). Then, the parameters of the even-order aspheric equation are obtained by linear least squares fitting of the discrete points (x(15°), z(15°)), (x(30°), z(30°)), and (x(45°), z(45°)), thereby determining the cross-sectional shape curve of the light-transmitting shell.

[0162] Finally, determine the position of the inner surface center, and use the inner surface center as the center of the sphere and the inner surface radius as the radius to determine the spherical shape of the inner surface. Based on the known size parameters of the laser radar, the spherical shape of the inner surface is intercepted to obtain the inner surface of the laser radar shell. Using modeling software, determine the curve shape of the cross-sectional curve based on the cross-sectional curve function. Using the central axis as the rotation axis, rotate the cross-sectional curve around the central axis once (i.e., 360°) to obtain the curved surface shape of the outer surface. Let the inner surface center be on the central axis, and let the inner surface center coincide with the origin of the coordinate axis of the outer surface interface curve function. Combine the inner and outer surfaces to construct the laser radar shell.

[0163] Based on the above-mentioned laser radar shell design method, the influence of the above-mentioned laser radar shell on the laser beam characteristics is simulated and verified by light simulation software modeling. Among them, the light source adopts a laser diode, the laser diode light emitting area is three-segment light emitting, the central wavelength is 905nm, the Gaussian width angle of the fast axis divergence angle is 16.9°, the corresponding half-peak width angle is 20.0°, the Gaussian width angle of the slow axis divergence angle is 8.5°, the corresponding half-peak width angle is 10.0°, and the curvature radius of the center of the front surface of the emitting lens is R E =5.58mm, center thickness d b The aperture is 1.2 mm, and the aperture is square, where a = 2.4 mm and b = 2.6 mm. The distance x between the emission axis and the rotation center axis is E The assembly distance margin Δ is 1.8 mm, so the distance z between the center of the reflector and the origin is r=8mm. The inner diameter R2 of the spherical surface of the transparent shell is 35mm, the material is PMMA, the corresponding refractive index n is 1.486, and the center thickness d is 2mm. According to formula (2), the initial function of the intercept curve of the outer surface of the laser radar shell is obtained, and N = 6000 discrete values θ are taken from 0° to 15° i The parameters of the even-order aspheric equation obtained by linear least squares fitting are:

[0164] r=35.65mm,k=-1,a4=2.73×10 -6 mm -3 ,a6=1.06×10 -9 mm -5 ,a8=5.15×10 -13 mm -7 ,a 10 =2.86×10 -16 mm -9 ,a 12 =9.88×10 -20 mm -11 ,a 14 =4.24×10 -22 mm -13 The curvature radius r obtained by fitting is consistent with the result obtained by the paraxial formula.

[0165] By using optical simulation software to compare and simulate the light spot patterns at a target of 10m without a shell, a spherical shell, and the laser radar shell described in this application, and calculating the height change dz of the center of mass of the light spot, the vertical pointing offset angle dσ=dz / L is obtained, as shown in FIG. Figure 10As shown in the figure, the simulation results show that in the absence of a housing, the laser diode achieves better collimated output through the emitting lens, and exhibits a clear three-section distribution at scanning angles of 0°, 45°, 90°, and 135°. After the introduction of the commonly used spherical shell housing, except for the 0° scanning angle, other scanning angles cannot show a three-section distribution, indicating that the spherical shell housing has a divergent effect on the collimated light beam. However, the introduction of the light-transmitting housing of the present invention shows a three-section distribution at all scanning angles, indicating that the light beam still maintains good collimation characteristics. When the spherical shell housing is at scanning angles of 0°, 45°, 90°, and 135°, the height change dz of the center of mass of the light spot is -43.0mm, -51.9mm, -77.3mm, and -108.5mm, respectively, and the corresponding vertical pointing offset angles dσ are -4.3mrad, -5.19mrad, -7.73mrad, and -10.85mrad, respectively. At scanning angles of 0°, 45°, 90°, and 135°, the housing of the present invention achieves a spot centroid height variation dz of -0.1mm, -0.5mm, -1.3mm, and -1.5mm, respectively. The corresponding vertical pointing offset angles dσ are -0.01mrad, -0.05mrad, -0.13mrad, and -0.15mrad, respectively. These values are essentially negligible relative to the beam divergence angle. Compared to a spherical shell, the transparent housing of the present invention eliminates its vertical deflection effect on the LiDAR's outgoing beam and significantly reduces its divergence.

[0166] It should be understood that, although the various steps in the flowcharts involved in the various embodiments described above are displayed in sequence according to the instructions of the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the flowcharts involved in the various embodiments described above can include multiple steps or multiple stages, and these steps or stages are not necessarily executed and completed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of steps or stages in other steps.

[0167] In one embodiment, a laser radar is provided, wherein a laser radar housing of the laser radar includes an inner surface and an outer surface; wherein,

[0168] The inner surface radius value of the inner surface is a value determined by a functional relationship and a target value of the horizontal divergence angle, wherein the functional relationship is a functional relationship between the horizontal divergence angle of the detection beam emitted by the laser radar and the laser radar parameters determined under the paraxial condition, and the laser radar parameters include the refractive index of the laser radar housing, the center thickness of the laser radar housing, and the inner surface radius;

[0169] The cross-sectional curve function of the outer surface is a function determined by the refractive index value, the center thickness value, and the inner surface radius value.

[0170] In an embodiment of the present application, the laser radar includes a laser radar shell, which is a shell with a certain thickness. The laser radar shell includes an inner surface and an outer surface. The inner surface radius value of the inner surface is determined by a functional relationship and a target value of the horizontal divergence angle, wherein, under paraxial conditions, the functional relationship between the horizontal divergence angle of the detection light beam emitted by the laser radar and the laser radar parameters is determined. The laser radar parameters include the refractive index of the laser radar shell, the center thickness of the laser radar shell and the inner surface radius.

[0171] The outer surface is a curved surface obtained by rotating a cross-sectional curve 360° around the central axis, where the cross-sectional curve is the intersection of the plane where the central axis is located and the outer surface of the lidar shell. The interface curve function is a function determined by the refractive index value, the central thickness value and the inner surface radius value.

[0172] In an embodiment of the present application, a paraxial ray tracing method is used to determine the functional relationship between the horizontal divergence angle of the detection light beam and the laser radar parameters, and the refractive index value, center thickness value and inner surface radius value in the laser radar parameters are determined through the functional relationship and the target value of the horizontal divergence angle, so as to control the horizontal divergence angle within a certain range to reduce the divergence of the detection light beam. The cross-sectional curve function of the outer surface of the laser radar housing can also be determined through the refractive index value, center thickness value and inner surface radius value. By changing the shape of the outer surface, the deflection caused by the refraction of the detection light beam through the laser radar housing can be eliminated, thereby ultimately achieving the purpose of improving the detection accuracy and performance of the laser radar.

[0173] In the embodiment of the present application, the method for constructing the laser radar housing can refer to the relevant description of the aforementioned embodiment, and the embodiment of the present application will not be repeated here.

[0174] In one embodiment, Figure 3a As shown, the laser radar further includes: a plane reflector, a transmitting lens and a laser light source; wherein,

[0175] The laser light source is used to emit a laser beam, which passes through an emitting lens and a plane reflector in sequence and then is emitted in a horizontal direction;

[0176] The laser light source is located at the focal plane of the emitting lens, the long side of the emitting lens is located in the fast axis direction of the laser beam, the short side of the emitting lens is located in the slow axis direction of the laser beam, and the long side direction of the emitting lens is perpendicular to the front detection direction of the laser radar;

[0177] The distance from the intersection of the plane reflector and the central axis to the center of the inner surface is the sum of the distance from the laser light source to the central axis, 1 / 2 of the short side of the emitting lens, and the assembly allowance.

[0178] In the embodiment of this application, Figure 11 As shown, the laser light source is located at the focal plane of the emitting lens. The laser beam emitted by the laser light source becomes a short side with a width of S after passing through the emitting lens. x , the long side width is S y beam, where S y Corresponding to the fast axis direction of the laser beam, S x Corresponding to the slow axis direction of the laser beam, the long side b of the emitting lens is located in the fast axis direction of the laser beam, the short side a of the emitting lens corresponds to the slow axis direction of the laser beam, and the long side b of the emitting lens is perpendicular to the detection direction in front of the laser radar, that is, the long side b is perpendicular to Figure 3a The x-axis is used to improve the angular resolution of the LiDAR directly in front of the sensor.

[0179] In the embodiment of the present application, the distance X from the laser light source to the central axis is E , 1 / 2 of the short side of the emitting lens: a / 2 and the assembly allowance are accumulated to determine the distance Z from the intersection of the plane reflector and the central axis to the center of the inner surface r In the laser radar, the larger the curvature radius of the laser radar shell irradiated by the laser beam, the smaller the divergence angle of the detection beam emitted by the laser radar. Therefore, in order to make the curvature radius of the laser radar shell irradiated by the laser beam as large as possible, the distance from the laser light source to the central axis is X E , 1 / 2 of the short side of the emitting lens: a / 2 and the sum of the assembly allowance, as the distance Z from the intersection of the plane reflector and the central axis to the center of the inner surface r .

[0180] In an embodiment of the present application, the long side direction of the emitting lens is perpendicular to the detection direction directly in front of the laser radar, which can improve the angular resolution directly in front of the laser radar, and the sum of the distance from the laser light source to the central axis, 1 / 2 of the short side of the emitting lens, and the assembly allowance is used as the distance from the intersection of the plane reflector and the central axis to the center of the sphere on the inner surface, so as to reduce the horizontal divergence angle of the detection light beam emitted by the laser radar and improve the detection accuracy and performance of the laser radar.

[0181] Based on the same inventive concept, the present application also provides a laser radar housing construction device for implementing the aforementioned laser radar housing construction method. The solution provided by this device is similar to the solution described in the aforementioned method. Therefore, the specific limitations of one or more laser radar housing construction device embodiments provided below can be found in the above-mentioned limitations of the laser radar housing construction method and will not be repeated here.

[0182] In one embodiment, Figure 12 As shown, a laser radar housing construction device is provided, including: a first determination module 1202, a second determination module 1204, a second determination module 1206 and a construction module 1208, wherein:

[0183] A first determining module 1202 is configured to determine, under a paraxial condition, a functional relationship between a horizontal divergence angle of a detection beam emitted by the laser radar and laser radar parameters, wherein the laser radar parameters include a refractive index of a laser radar housing, a center thickness of the laser radar housing, and an inner surface radius of the laser radar housing;

[0184] A second determining module 1204 is configured to determine a refractive index value, a center thickness value, and an inner surface radius value of the laser radar housing according to the functional relationship and a target value of the horizontal divergence angle;

[0185] A third determining module 1206 is configured to determine a cross-sectional curve function of the outer surface of the lidar housing based on the refractive index value, the center thickness value, and the inner surface radius value, where the cross-sectional curve is formed by the intersection of a plane passing through the central axis of the lidar housing and the outer surface, and the central axis passes through the center of the inner surface and is perpendicular to the horizontal direction.

[0186] The construction module 1208 is used to construct the laser radar shell according to the inner surface radius value and the cross-sectional curve function.

[0187] In an embodiment of the present application, under paraxial conditions, the functional relationship between the horizontal divergence angle of the detection light beam and the laser radar parameters is determined, and the refractive index value, center thickness value and inner surface radius value in the laser radar parameters are determined through the functional relationship and the target value of the horizontal divergence angle, so as to control the horizontal divergence angle within a certain range to reduce the divergence of the detection light beam. The cross-sectional curve function of the outer surface of the laser radar shell can also be determined through the refractive index value, center thickness value and inner surface radius value. By changing the shape of the outer surface, the deflection caused by the refraction of the detection light beam through the laser radar shell can be eliminated, thereby ultimately achieving the purpose of improving the detection accuracy and performance of the laser radar.

[0188] In one embodiment, the apparatus further comprises:

[0189] a fourth determining module, configured to determine a value range of a horizontal divergence angle according to a preset width and a preset proportional coefficient of the detection beam;

[0190] The fifth determining module is configured to determine a target value of the horizontal divergence angle according to a value range of the horizontal divergence angle.

[0191] In one embodiment, the third determining module 1206 is further configured to:

[0192] Determine a first optical path according to the refractive index value, the center thickness value, and the inner surface radius value. The first optical path is the distance of the first laser beam from the inner surface center to the target plane. The first laser beam is a laser beam emitted from the inner surface center in a horizontal direction.

[0193] Determine a second optical path according to the tilt angle, the refractive index value, the center thickness value, and the inner surface radius value. The second optical path is the distance the second laser beam travels from the central axis to the target plane. The second laser beam is a laser beam emitted from the central axis in a horizontal direction. The target plane is perpendicular to the first laser beam and the second laser beam, respectively. The second laser beam intersects with the inner surface to form an intersection point. The line connecting the intersection point and the center of the inner surface forms a first radius. The angle between the first radius and the second laser beam is the tilt angle.

[0194] A cross-sectional curve function of the outer surface of the laser radar housing is determined according to the first optical path and the second optical path.

[0195] In one embodiment, the third determining module 1206 is further configured to:

[0196] Determine an optical path equation based on the first optical path and the second optical path;

[0197] According to the optical path equation, multiple discrete points on the cross-sectional curve are obtained;

[0198] Each discrete point is fitted to obtain the cross-sectional curve function.

[0199] In one embodiment, the third determining module 1206 is further configured to:

[0200] The least square method is combined with an even-order aspheric curve equation to fit each of the discrete points to obtain the cross-sectional curve function.

[0201] In one embodiment, the building module 1208 is further configured to:

[0202] Determine the inner surface according to the inner surface center and inner surface radius;

[0203] Determine the cross-sectional curve according to the cross-sectional curve function;

[0204] Taking the central axis as the rotation axis, the cross-section curve is rotated to obtain the outer surface;

[0205] Construct the lidar housing based on the inner and outer surfaces.

[0206] Each module in the aforementioned LiDAR housing construction device can be implemented in whole or in part through software, hardware, or a combination thereof. Each module can be embedded in or independent of a processor in a computer device in hardware form, or stored in a computer device memory in software form, so that the processor can call and execute the corresponding operations of each module.

[0207] In one embodiment, a computer device is provided. The computer device may be a terminal, and its internal structure diagram may be as follows: Figure 13 As shown. The computer device includes a processor, memory, communication interface, display screen and input device connected via a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be achieved through WIFI, mobile cellular network, NFC (near field communication) or other technologies. When the computer program is executed by the processor, a method for constructing a lidar housing is implemented. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covering the display screen, or a button, trackball or touchpad provided on the computer device housing, or an external keyboard, touchpad or mouse.

[0208] Those skilled in the art will understand that Figure 13 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0209] In one embodiment, a computer device is further provided, including a memory and a processor. The memory stores a computer program, and the processor implements the steps in the above method embodiments when executing the computer program.

[0210] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0211] In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above method embodiments when executed by a processor.

[0212] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties.

[0213] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiment methods can be implemented by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, database or other media used in the embodiments provided in this application may include at least one of non-volatile and volatile memory. Non-volatile memory may include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory may include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, distributed databases based on blockchains. The processor involved in the various embodiments provided herein may be, but are not limited to, a general-purpose processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic unit, a data processing logic unit based on quantum computing, and the like.

[0214] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0215] The above embodiments merely represent several implementation methods of the present application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present application. It should be noted that those skilled in the art may make various modifications and improvements without departing from the concept of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be based on the appended claims.

Claims

1. A method for constructing a laser radar housing, characterized in that: The method comprises: Under paraxial conditions, determining a functional relationship between a horizontal divergence angle of a detection beam emitted by the laser radar and laser radar parameters, wherein the laser radar parameters include a refractive index of a laser radar housing, a center thickness of the laser radar housing, and an inner surface radius of the laser radar housing; Determining a refractive index value, a center thickness value, and an inner surface radius value of the laser radar housing according to the functional relationship and the target value of the horizontal divergence angle; Determine a cross-sectional curve function of the outer surface of the laser radar housing according to the refractive index value, the center thickness value, and the inner surface radius value, where a curve formed by the intersection of a plane passing through the central axis of the laser radar housing and the outer surface is the cross-sectional curve, and the central axis passes through the center of the inner surface and is perpendicular to the horizontal direction; Taking the center of the inner surface as the center of the sphere and the inner surface radius as the radius, the spherical shape of the inner surface is determined, and according to the known size parameters of the laser radar, the spherical shape of the inner surface is intercepted to obtain the inner surface of the laser radar shell; the curve shape of the cross-sectional curve is determined according to the cross-sectional curve function, and the central axis is used as the rotation axis, and the cross-sectional curve is rotated 360° around the central axis to obtain the curved surface shape of the outer surface; the center of the inner surface is made on the central axis, and the center of the inner surface coincides with the origin of the coordinate axis where the cross-sectional curve function of the outer surface is located, and the inner surface and the outer surface are combined to construct the laser radar shell.

2. The method according to claim 1, characterized in that The method further comprises: Determining a value range of the horizontal divergence angle according to a preset width and a preset proportional coefficient of the detection beam; A target value of the horizontal divergence angle is determined according to a value range of the horizontal divergence angle.

3. The method according to claim 1 or 2, characterized in that Determining a cross-sectional curve function of the outer surface of the laser radar housing according to the refractive index value, the center thickness value, and the inner surface radius value includes: determining a first optical path according to the refractive index value, the center thickness value, and the inner surface radius value, where the first optical path is an optical path of a first laser beam from the center of the inner surface sphere to a target plane, and the first laser beam is a laser beam emitted from the center of the inner surface sphere in a horizontal direction; Determining a second optical path according to the inclination angle, the refractive index value, the center thickness value, and the inner surface radius value, where the second optical path is an optical path of a second laser beam from the central axis to the target plane, the second laser beam is a laser beam emitted from the central axis in a horizontal direction, the target plane is perpendicular to the first laser beam and the second laser beam, respectively, the second laser beam intersects with the inner surface to form an intersection point, a line connecting the intersection point and the center of the inner surface forms a first radius, and an angle between the first radius and the second laser beam is the inclination angle; A cross-sectional curve function of the outer surface of the laser radar housing is determined based on the first optical path and the second optical path.

4. The method according to claim 3, characterized in that Determining a cross-sectional curve function of an outer surface of the laser radar housing according to the first optical path and the second optical path includes: Determining an optical path equation based on the first optical path and the second optical path; According to the optical path equation, a plurality of discrete points on the cross-sectional curve are obtained; Each of the discrete points is fitted to obtain the cross-sectional curve function.

5. The method according to claim 4, characterized in that The step of fitting the discrete points to obtain the cross-sectional curve function includes: The least square method is combined with an even-order aspheric curve equation to fit each of the discrete points to obtain the cross-sectional curve function.

6. A laser radar, characterized in that: The laser radar housing of the laser radar is constructed by combining an inner surface and an outer surface; wherein the inner surface and the outer surface are both determined based on the method described in any one of claims 1 to 5 above.

7. The laser radar according to claim 6, characterized in that The laser radar further includes: a plane reflector, a transmitting lens and a laser light source; wherein, The laser light source is used to emit a laser beam, and the laser beam passes through the emitting lens and the plane reflector in sequence and then emerges in a horizontal direction; The laser light source is located at the focal plane of the emitting lens, the long side of the emitting lens is located in the fast axis direction of the laser beam, the short side of the emitting lens is located in the slow axis direction of the laser beam, and the long side direction of the emitting lens is perpendicular to the front detection direction of the laser radar; The distance from the intersection of the plane reflector and the central axis to the center of the inner surface is the sum of the distance from the laser light source to the central axis, 1 / 2 of the short side of the emitting lens, and the assembly margin.

8. A laser radar housing construction device, characterized in that: The device comprises: A first determination module is configured to determine, under a paraxial condition, a functional relationship between a horizontal divergence angle of a detection beam emitted by the laser radar and laser radar parameters, wherein the laser radar parameters include a refractive index of a laser radar housing, a center thickness of the laser radar housing, and an inner surface radius of the laser radar housing; A second determination module is configured to determine a refractive index value, a center thickness value, and an inner surface radius value of the laser radar housing according to the functional relationship and the target value of the horizontal divergence angle; a third determining module, configured to determine a cross-sectional curve function of the outer surface of the laser radar housing according to the refractive index value, the center thickness value, and the inner surface radius value, wherein a curve formed by the intersection of a plane passing through a central axis of the laser radar housing and the outer surface is the cross-sectional curve, and the central axis passes through the center of the inner surface and is perpendicular to the horizontal direction; A construction module is used to determine the spherical shape of the inner surface with the center of the inner surface as the center and the inner surface radius as the radius, and to intercept the spherical shape of the inner surface according to the known size parameters of the laser radar to obtain the inner surface of the laser radar shell; to determine the curve shape of the cross-sectional curve according to the cross-sectional curve function, to rotate the cross-sectional curve 360° around the central axis with the central axis as the rotation axis to obtain the curved surface shape of the outer surface; to make the center of the inner surface on the central axis, and the center of the inner surface coincide with the origin of the coordinate axis where the cross-sectional curve function of the outer surface is located, and to combine the inner surface and the outer surface to construct the laser radar shell.

9. The device according to claim 8, characterized in that The device further comprises: a fourth determining module, configured to determine a value range of a horizontal divergence angle according to a preset width and a preset proportional coefficient of the detection beam; The fifth determining module is configured to determine a target value of the horizontal divergence angle according to a value range of the horizontal divergence angle.

10. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 5 are implemented.

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