A method for determining a laser radar transmitting optical system and electronic equipment

Abstract

The present invention is applicable to the field of laser radar technology, and provides a method for determining a laser radar transmitting optical system and an electronic device, the method comprising: constructing a transmitting optical system, the transmitting optical system comprising a light source, a Behan prism and a plano-convex lens; obtaining a first refractive index and a second refractive index of the system; calculating a first length and a second length of the incident aperture of the Behan prism based on the constraint that the edge light can pass through the Behan prism and enter the plano-convex lens; calculating an ellipsoidal surface equation of the plano-convex lens based on the first refractive index, the second refractive index and the principle of equal optical path; calculating the thickness of the plano-convex lens at the optical axis based on the incident height of the edge light in the plano-convex lens; adjusting the above-mentioned transmitting optical system based on the first length, the second length, the ellipsoidal surface equation and the thickness. The method for determining a laser radar transmitting optical system provided by the present invention can reduce the size of the system under the premise of ensuring the transmitting power, and realize the miniaturization of the system.

Description

Technical Field

[0001] The present invention belongs to the technical field of laser radar, and in particular relates to a method for determining a laser radar transmitting optical system and electronic equipment. Background Art

[0002] Laser radar has excellent performances of high ranging accuracy, high angular resolution and high repetition frequency, and is widely used in intelligent robots, automatic tractors, assisted driving, security and other fields. In laser radar, the functions of the emission optical system include light source power output, beam collimation and shaping, etc. The performance of the emission optical system is directly related to the performance of laser radar in detecting, measuring and locating targets.

[0003] In the emitting optical system of the laser radar, the smaller the divergence angle of the output light beam, the higher its angular resolution, but the corresponding focal length of the emitting optical system becomes larger, which will cause the length and cost of the emitting optical system to increase, which is not conducive to the development trend of miniaturization and low cost of laser radar. Summary of the invention

[0004] In view of this, an embodiment of the present invention provides a method for determining a laser radar transmitting optical system and an electronic device, which can reduce the system size while ensuring that the transmitting optics provide transmitting power.

[0005] A first aspect of an embodiment of the present invention provides a method for determining a laser radar transmitting optical system, comprising:

[0006] Constructing an emission optical system, the emission optical system comprising a light source, a Behan prism and a plano-convex lens; the light source is arranged on the incident surface of the Behan prism and is located on the incident light axis of the Behan prism; the plane of the plano-convex lens is in contact with the exit surface of the Behan prism;

[0007] Acquire a first refractive index and a second refractive index of the emitting optical system; the first refractive index is the refractive index of the Behan prism, and the second refractive index is the refractive index of the plano-convex lens;

[0008] Based on the constraint that the edge light can pass through the Behan prism and enter the plano-convex lens, a first length and a second length of the incident aperture of the Behan prism are calculated; the first length is the length of the incident aperture on the main section; the second length is the length of the incident aperture perpendicular to the main section;

[0009] Calculating the ellipsoidal surface equation of the plano-convex lens based on the first refractive index, the second refractive index and the equal optical path principle;

[0010] Calculating the thickness of the plano-convex lens at the optical axis based on the incident height of the marginal light in the plano-convex lens;

[0011] The emission optical system is adjusted based on the first length, the second length, the ellipsoidal surface equation, and the thickness.

[0012] A second aspect of an embodiment of the present invention provides a laser radar transmitting optical system, comprising a light source, a Behan prism and a plano-convex lens; the light source is arranged on the incident surface of the Behan prism and is located on the incident optical axis of the Behan prism; the plane of the plano-convex lens is in contact with the exit surface of the Behan prism;

[0013] Among them, the ellipsoidal surface equation of the plano-convex lens, the thickness of the plano-convex lens at the optical axis, the first length and the second length are determined based on the method described above, the first length is the length of the incident aperture of the Byehan prism on the main cross-section of the Byehan prism, and the second length is the length of the incident aperture of the Byehan prism in a direction perpendicular to the main cross-section of the Byehan prism.

[0014] A third aspect of an embodiment of the present invention provides a laser radar, comprising the laser radar transmitting optical system as described above.

[0015] A fourth aspect of an embodiment of the present invention provides a device for determining a laser radar transmitting optical system, comprising:

[0016] An emission optical system construction module is used to construct an emission optical system, wherein the emission optical system includes a light source, a Behan prism and a plano-convex lens; the light source is arranged on the incident surface of the Behan prism and is located on the incident optical axis of the Behan prism; the plane of the plano-convex lens is in contact with the exit surface of the Behan prism;

[0017] An acquisition module, used to acquire a first refractive index and a second refractive index, a first half divergence angle, and a second half divergence angle of the emitting optical system; the first refractive index is the refractive index of the Behan prism, and the second refractive index is the refractive index of the plano-convex lens;

[0018] An incident aperture calculation module, used to calculate a first length and a second length of the incident aperture of the Behan prism based on the constraint that the edge light can pass through the Behan prism and enter the plano-convex lens; the first length is the length of the incident aperture on the main section, and the second length is the length of the incident aperture perpendicular to the main section;

[0019] An ellipsoidal surface equation calculation module, used for calculating the ellipsoidal surface equation of the plano-convex lens based on the first refractive index, the second refractive index and the equal optical path principle;

[0020] A thickness calculation module, used to calculate the thickness of the plano-convex lens at the optical axis based on the incident height of the edge light in the plano-convex lens;

[0021] An adjustment module, for adjusting the emission optical system based on the first length, the second length, the ellipsoidal surface equation and the thickness

[0022] A fifth aspect of an embodiment of the present invention provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above method when executing the computer program.

[0023] A sixth aspect of an embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method described above are implemented.

[0024] A seventh aspect of an embodiment of the present invention provides a computer program product. When the computer program product is run on an electronic device, the electronic device executes the steps of any one of the methods described in the first aspect.

[0025] Compared with the prior art, the embodiments of the present invention have the following beneficial effects: the method for determining the laser radar transmitting optical system provided by the embodiments of the present invention includes constructing a transmitting optical system, the transmitting optical system includes a light source, a Behan prism and a plano-convex lens; obtaining a first refractive index and a second refractive index of the transmitting optical system; calculating a first length and a second length of the incident aperture of the Behan prism based on the constraint that the edge light can pass through the Behan prism and enter the plano-convex lens; calculating the ellipsoidal surface equation of the plano-convex lens based on the first refractive index, the second refractive index and the principle of equal optical path; calculating the thickness of the plano-convex lens at the optical axis based on the incident height of the edge light in the plano-convex lens; adjusting the above-mentioned transmitting optical system based on the first length, the second length, the ellipsoidal surface equation and the thickness. The method for determining the laser radar transmitting optical system provided by the embodiments of the present invention can reduce the size of the system under the premise of ensuring the transmitting power, thereby realizing the miniaturization of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0027] Figure 1a is a schematic diagram of the three-dimensional structure of a laser radar transmitting optical system provided by an embodiment of the present invention;

[0028] Figure 1b yes Figure 1a A cross-sectional view of the laser radar transmitting optical system in the direction of the main cross-section of the Behan prism;

[0029] Figure 2 It is a schematic diagram of the implementation flow of the method for determining the laser radar transmitting optical system provided by an embodiment of the present invention;

[0030] Figure 3a It is a schematic diagram of light beam transmission in the main cross-section direction of the Behan prism in the method for determining the laser radar transmitting optical system provided by an embodiment of the present invention;

[0031] Figure 3b It is the expanded diagram of the light beam propagation in the main cross-section direction of the Bihan prism.

[0032] Figure 4 It is another schematic diagram of the light beam transmission principle in the method for determining the laser radar transmitting optical system provided by an embodiment of the present invention;

[0033] Figure 5 is an equivalent optical path diagram in the method for determining the laser radar transmitting optical system provided in an embodiment of the present invention;

[0034] Figure 6 It is a schematic diagram of the effect of the method for determining the laser radar transmitting optical system provided by an embodiment of the present invention;

[0035] Figure 7a is the light intensity distribution of the light beam at the exit surface of the Bihan prism in the method for determining the laser radar transmitting optical system provided by an embodiment of the present invention;

[0036] Figure 7b is the light intensity distribution of the light beam at 100 meters after being collimated and output by a plano-convex lens in the method for determining the laser radar transmitting optical system provided in an embodiment of the present invention;

[0037] Figure 8 is a schematic diagram of the structure of a device for determining a laser radar transmitting optical system provided by an embodiment of the present invention;

[0038] Fig. 9 It is a schematic diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0039] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0040] In order to illustrate the technical solution of the present invention, a specific embodiment is provided below for illustration.

[0041] The transmitting optical system of LiDAR usually uses a convex lens system to achieve laser power output and beam collimation. The light source needs to be placed at the focal plane of the convex lens. In order to ensure efficient power output, the divergence angle of the light source and the semi-aperture size and focal length of the lens system need to meet Among them, α is the divergence angle of the light source, r is the semi-aperture size of the convex lens, and f is the focal length of the convex lens. The divergence angle of the collimated laser output beam depends on the half-height of the light source and the focal length of the convex lens, which can be expressed as: Among them, θ is the output beam divergence angle, y is the half height of the light source, and f is the focal length of the convex lens. In order to reduce the output beam divergence angle, the focal length of the convex lens needs to be increased, which will increase the length of the transmitting optical system, which is not conducive to the miniaturization of the lidar.

[0042] Figure 1a and Figure 1b The schematic diagram of the structure of the laser radar transmitting optical system provided by the embodiment of the present invention is shown. Figure 1a This is a schematic diagram of the three-dimensional structure of the laser radar transmitting optical system. Figure 1b The sectional view of the transmitting optical system in the main section direction of the Behan prism. The above-mentioned laser radar transmitting optical system includes a light source, a Behan prism and a plano-convex lens. The light source is arranged on the incident surface of the Behan prism and is located on the incident light axis of the Behan prism, and the plane of the plano-convex lens is in contact with the exit surface of the Behan prism.

[0043] exist Figure 1a and Figure 1b Middle, side E 1 E 2 A 2 A 1 is the incident plane of the Bihan prism, surface D 1 D 2 C 2 'C 1 ' is the exit plane of the Behan prism. The length of the incident plane in the direction of the main section is a, and the length in the direction perpendicular to the main section is b; the length of the exit plane in the direction of the main section is e, and the length in the direction perpendicular to the main section is b. The Behan prism is composed of a Schmidt prism and a pentagonal prism. In this embodiment, the incident plane E 1 E 2 A 2 A 1 Prism E 1 A 1 B 1 C 1 -E 2 A 2 B 2 C 2 For Schmidt prism, the exit plane D 1 D 2 C 2 'C1 'The prism D 1 C 1 'E 1 '-D 2 C 2 'E 2 ' is a pentagonal prism.

[0044] Figure 2 FIG. 1 is a schematic diagram showing the implementation flow of the method for determining the laser radar transmitting optical system provided by an embodiment of the present invention. Figure 2 The laser radar transmitting optical system determination method provided by an embodiment of the present invention may include steps S101 to S106.

[0045] S101: constructing an emission optical system, the emission optical system comprising a light source, a Behan prism and a plano-convex lens. The light source is arranged on the incident surface of the Behan prism and is located on the incident optical axis of the Behan prism, and the plane of the plano-convex lens is in contact with the exit surface of the Behan prism.

[0046] In some embodiments, the structure of the transmitting optical system is as follows Figure 1a and Figure 1b As shown, in Figure 1a and Figure 1b In the figure, the light source S is located at the center point O' of the incident surface of the Bihan prism.

[0047] Specifically, the light source is close to the incident surface of the Bihan prism, and the plane of the plano-convex lens is close to the exit surface of the Bihan prism.

[0048] Optionally, the light source is a laser diode.

[0049] Laser diodes have an astigmatism characteristic, that is, the emitted light beam is distributed in an asymmetric elliptical shape relative to the chip junction, with a larger divergence angle in the fast axis direction and a smaller divergence angle in the slow axis direction.

[0050] In a specific example, the slow axis direction of the laser diode is the y-axis direction, and the fast axis direction is the x-axis direction.

[0051] In some embodiments, the exit aperture plane of the Bihan prism is bonded to the plane of the plano-convex lens.

[0052] In a specific example, the thickness of the adhesive bonded to the plano-convex lens is 50 to 100 microns, and the adhesive is applied on the surface D 1 D 2 B 2 B 1 At the edge of the coating, the coating width is 0.5 to 1 mm.

[0053] Optionally, the fixing method between the Bihan prism and the plano-convex lens includes pressing, tightening, etc.

[0054] In some embodiments, before S101, the method for designing a laser radar transmitting optical system further includes:

[0055] Based on the total reflection condition of the Bihan prism in the main section direction, the first constraint condition between the first half divergence angle and the first refractive index is calculated, where the first half divergence angle α h is the half divergence angle of the light source parallel to the main section of the Bihan prism.

[0056] Figure 3a and Figure 3b The schematic diagram of the light beam transmission principle in the main cross-section direction of the Behan prism in the method for determining the laser radar transmission optical system provided by the embodiment of the present invention is shown. Figure 3a Schematic diagram of beam transmission in the main cross-section direction of the Bihan prism. Figure 3b This is the expanded view of the main cross-section direction of the Bihan prism.

[0057] See also Figure 3a and Figure 3b , in the main section direction, the half divergence angle of the light source S is α h The transmission process of the light beam in the emitting optical system includes: it is incident from the incident surface EA to the Schmidt prism, is totally reflected at the EC surface, is reflected again at the AB surface, enters the pentagonal prism through the EC and E'C' surfaces; it is totally reflected at the DC' surface, is reflected again at the E'D surface and E'C' surface in turn, and finally is emitted through the DC' surface and is collimated by the plano-convex lens.

[0058] In this embodiment, the Bihan prism can realize optical path folding, greatly increasing the focal length of the system in a limited space.

[0059] Specifically, the AB surface and the E'D surface can be coated with a high-reflection film specific to the wavelength of the light source.

[0060] See also Figure 3a and Figure 3b In the direction of the main section, the total reflection condition is reflected in the fact that the edge light can be totally reflected at the EC surface and the DC' surface.

[0061] According to the geometric properties of the Bihan prism, the first constraint can include: Among them, n 1 is the first refractive index, i.e. the refractive index of the Bihan prism; α h is the first half divergence angle, that is, the half divergence angle of the light source parallel to the main cross section of the Bihan prism.

[0062] Based on the total reflection condition of the Behan prism in the direction perpendicular to the main section, the second constraint condition between the second half divergence angle and the first refractive index is calculated, where the second half divergence angle α v is the half divergence angle of the light source perpendicular to the main section of the Bihan prism.

[0063] Figure 4 The diagram shows the principle diagram of light beam transmission perpendicular to the main cross-section direction of the Bihan prism in the method for determining the laser radar transmission optical system provided by an embodiment of the present invention.

[0064] See also Figure 4 In the direction perpendicular to the main section of the Bihan prism, the total reflection condition is reflected in the fact that the edge light can be totally reflected at the EC surface and the DC' surface.

[0065] According to the geometric properties of the Bihan prism, the second constraint can include: Among them, n 1 is the first refractive index, i.e. the refractive index of the Bihan prism; α v is the second half divergence angle, that is, the half divergence angle of the light source perpendicular to the main cross section of the Bihan prism.

[0066] Determine a light source and a Bihan prism that satisfy the first constraint and the second constraint.

[0067] In some embodiments, before S101, the method for determining the laser radar transmitting optical system further includes:

[0068] Based on the geometric properties of the Pechan prism, a third constraint between the first half divergence angle and the first refractive index is calculated.

[0069] See also Figure 3a and Figure 3b , based on the geometric properties of the Behan prism, in the direction of the main section of the Behan prism, in order to ensure that both the central light and the edge light can pass through the Behan prism and enter the plano-convex lens, the third constraint condition includes: Among them, n 1 is the first refractive index, i.e. the refractive index of the Bihan prism; α h is the first half divergence angle, that is, the half divergence angle of the light source parallel to the main cross section of the Bihan prism.

[0070] Determine the light source and the Bihan prism that satisfy the third constraint.

[0071] It can be seen from the third constraint that, based on the fixed geometric properties of the Behan prism, the angle at which it receives edge light is only related to the first refractive index of the Behan prism. The larger the first refractive index, the larger the allowed divergence angle.

[0072] S102: Obtaining the first refractive index n of the emitting optical system 1 and the second refractive index n 2 The first refractive index n 1 is the refractive index of the Bihan prism, the second refractive index n 2 is the refractive index of the plano-convex lens.

[0073] S103: Based on the constraint that the edge light can pass through the Bihan prism into the plano-convex lens, calculate the first length a and the second length b of the Bihan prism incident aperture; the first length a is the length of the incident aperture on the main section; the second length b is the length of the incident aperture perpendicular to the main section.

[0074] In some embodiments, S103 may include:

[0075] The length limit of the exit aperture of the Behan prism on the main cross section is obtained, and the value range of the first length is determined according to the geometric properties of the Behan prism and the length limit of the exit aperture on the main cross section.

[0076] according to Calculate the minimum value of the second length; where α v is the second half divergence angle, b is the second length, L is the distance of the light beam along the optical axis in the Bihan prism, n 1 The minimum value of the second length is taken as the second length.

[0077] The embodiment of the present invention can determine the incident aperture of the Pehan prism according to the astigmatism characteristics of the laser diode, match the incident aperture with the beam distribution characteristics of the laser diode, and optimize the size of the emission optical system.

[0078] S104: Calculate the ellipsoidal surface equation of the plano-convex lens based on the first refractive index, the second refractive index and the equal optical path principle.

[0079] Figure 5 The equivalent optical path diagram of the light beam transmission in the main cross-section direction of the Bihan prism of the emitting optical system provided by the embodiment of the present invention is shown.

[0080] Based on Fermat's equal-path principle and the law of refraction, the upper half divergence angle of the main section is α h The process of the light beam passing through the Bihan prism and then collimated by the plano-convex lens needs to satisfy the following relationship:

[0081]

[0082] Among them, Δ 1 is the distance from the light source to the incident surface of the Behan prism, Δ is the distance between the two bonding surfaces inside the Behan prism, and Δ 2 is the distance from the exit surface of the Bihan prism to the plane of the plano-convex lens, α h is the first half divergence angle, α′ h is the refraction angle of the marginal ray incident on the Bihan prism, β′ h is the refraction angle of the marginal ray incident on the plano-convex lens, n 1 is the first refractive index, n 2is the second refractive index, d is the thickness of the plano-convex lens at the optical axis, x is the distance along the optical axis that the edge light is incident on the plano-convex lens, and L is the distance along the optical axis that the light beam is in the Bihan prism.

[0083] In this embodiment, the smaller the distance from the light source to the incident surface of the Behan prism, the distance between the two bonding surfaces inside the Behan prism, and the distance from the exit surface of the Behan prism to the plane of the plano-convex lens, the smaller the size of the emission optical system. Figure 1a Medium Schmidt Prism E 1 A 1 B 1 C 1 -E 2 A 2 B 2 C 2 The exit surface E 1 C 1 C 2 E 2 and Penta Prism D 1 C 1 'E 1 '-D 2 C 2 'E 2 'The incident surface E 1 'C 1 'C 2 'E 2 '.

[0084] In a specific example, when the light source is close to the incident surface of the Behan prism, the pentaprism inside the Behan prism is closely fitted with the Schmidt prism, and the exit surface of the Behan prism is bonded to the plano-convex lens, the above three distances are regarded as zero.

[0085] At this time, the equivalent distance of the light beam along the optical axis in the Bihan prism is Where a is the length of the incident aperture of the Bihan prism on the main cross section.

[0086] Based on the geometric properties of the Behan prism, the actual length of the Behan prism is Where a is the length of the entrance aperture of the Bihan prism on the main section. Figure 1a , the actual length c of the Behan prism is the incident surface E of the Behan prism 1 E 2 A 2 A 1 and the exit surface D 1 D 2 C 2 'C 1 'The distance between.

[0087] In some embodiments, the first refractive index is equal to the second refractive index, and the ellipsoidal surface equation comprises:

[0088]

[0089] Wherein, x′ and y′ are the coordinate values ​​of the ellipsoidal surface in the direction of the main cross section of the Behan prism, n is the first refractive index and the second refractive index, L is the distance of the light beam in the Behan prism along the optical axis, and d is the thickness of the plano-convex lens at the optical axis.

[0090] Furthermore, when the first refractive index is equal to the second refractive index, the equivalent focal length of the emitting optical system is:

[0091] Actual length of the launch optics Where, f′ is the equivalent focal length of the emitting optical system, n is the refractive index of the emitting optical system; a is the first length, that is, the length of the incident aperture on the main section; d is the thickness of the plano-convex lens at the optical axis; L is the distance of the light beam along the optical axis in the Bihan prism, L s is the actual length of the transmitting optical system, and c is the actual length of the Bihan prism.

[0092] In some embodiments, in order to achieve miniaturization of the transmitting optical system, it is necessary to reduce the ratio of the system length to the equivalent focal length.

[0093] Specifically, the ratio of the system length to the equivalent focal length is: It can be seen that in order to reduce the ratio, it is necessary to reduce the refractive index and the thickness of the plano-convex lens.

[0094] S105: Calculate the thickness of the plano-convex lens at the optical axis based on the incident height of the marginal light in the plano-convex lens.

[0095] In some embodiments, S105 may include:

[0096] Calculate a first lower limit value of the thickness based on the thickness constraint condition in the main cross-section direction;

[0097] Calculate a second lower limit value of the thickness based on a thickness constraint condition in a direction perpendicular to the main section;

[0098] The larger value between the first lower limit value and the second lower limit value is taken as the thickness of the plano-convex lens at the optical axis.

[0099] Specifically, the above constraint condition is that the thickness of the plano-convex lens at the optical axis is limited by the incident height of the marginal light, that is, in the ellipsoidal surface equation, when x′=0, the value of y′ is greater than the exit aperture height of the Bihan prism.

[0100] Among them, when x′=0,

[0101] In the main cross-section direction, the exit aperture height of the Bihan prism is In the direction perpendicular to the main section, the exit aperture height of the Bihan prism is

[0102] In some embodiments, the thickness constraints in the main cross-sectional direction include:

[0103]

[0104] Thickness constraints in the direction perpendicular to the main section include:

[0105]

[0106] Wherein, d is the thickness of the plano-convex lens at the optical axis, n is the first refractive index and the second refractive index, L is the distance of the light beam in the Bihan prism along the optical axis, a is the first length, and b is the second length.

[0107] S106: Adjust the emission optical system based on the first length, the second length, the ellipsoidal surface equation and the thickness.

[0108] The method for determining the laser radar transmitting optical system provided by the embodiment of the present invention can reduce the size of the system while ensuring the transmitting power, thereby realizing the miniaturization of the system. Based on the optical path folding principle of the Pehan prism and the collimation effect of the plano-convex lens on the light beam, the transmitting optical system can obtain a larger equivalent focal length under a certain system length, while effectively reducing the light beam divergence angle, making the system structure more compact, smaller in size, and lower in cost. On the other hand, the aperture size that matches the edge light is designed according to the astigmatism characteristics of the laser diode, so as to further improve the space utilization of the transmitting optical system.

[0109] In a specific example, a laser diode with a laser wavelength of 905 nanometers is selected as the light source, the luminous power is 75 watts, the active area is three-section luminescence, and the size is 235×20μm; 235 The peak half-intensity divergence angle of its fast axis is 20°, and the peak half-divergence angle of its slow axis is 10°.

[0110] The slow axis direction of the laser diode is set to be parallel to the main section of the Behan prism, and the fast axis direction is set to be perpendicular to the main section of the Behan prism, then the first half divergence angle is α h =16.98°, the second half divergence angle is α v =8.49°.

[0111] Based on the first constraint, the second constraint and the third constraint, the D-ZPK1A material is selected to make the emission optical system. For the above laser wavelength, the refractive index of the material is 1.612.

[0112] In this embodiment, the divergence angle of the outgoing light beam can be expressed as: Among them, θ is the divergence angle of the emitted light beam, y is the half-height of the light source, n is the refractive index of the emitting optical system, d is the thickness of the plano-convex lens at the optical axis, and L is the distance of the light beam along the optical axis in the Bihan prism.

[0113] Based on the above steps, the incident aperture of the Bihan prism is calculated, and the first length a=10.00 mm, the second length b=20.38 mm, the exit aperture e=16.23 mm, and b=20.38 mm are obtained.

[0114] Further calculations show that the ellipsoidal cone coefficient of the plano-convex lens is: The radius of curvature is: R = 19.98 mm, and the thickness at the optical axis is d = 6 mm.

[0115] Figure 6 FIG. 1 is a schematic diagram showing the effect of the method for determining the laser radar transmitting optical system provided by an embodiment of the present invention, see Figure 6 , this example shows that the emission optical system can achieve collimated output of the laser beam.

[0116] Figure 7a and Figure 7b Another effect schematic diagram of the method for determining the laser radar transmitting optical system provided by an embodiment of the present invention is shown, wherein Figure 7a The intensity distribution of the light beam at the exit surface of the Bihan prism is shown. Figure 7b The figure shows the light intensity distribution of the light beam at 100 meters after being collimated by a plano-convex lens.

[0117] Depend on Figure 7a and Figure 7b It can be seen that the exit aperture of the Bihan prism matches the beam distribution of the laser diode, which can improve the space utilization of the system. The optical power received by the detector at 100 meters is 73 watts, and the transmission efficiency is 97%. It can be seen that the determination method provided by the embodiment of the present invention can achieve efficient output by utilizing the total reflection characteristics and the matching of the incident aperture and the beam; the square distribution shows that the laser light source has three sections, and the spot size is 378mm×32mm.

[0118] The system length finally obtained by the embodiment of the present invention is The equivalent focal length is The size of the transmitting optical system can be effectively reduced.

[0119] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0120] An embodiment of the present invention provides a laser radar transmitting optical system, including a light source, a Behan prism and a plano-convex lens; the light source is arranged on the incident surface of the Behan prism and is located on the incident optical axis of the Behan prism, and the plane of the plano-convex lens is in contact with the exit surface of the Behan prism. Among them, the ellipsoidal surface equation of the plano-convex lens, the thickness of the plano-convex lens at the optical axis, the first length and the second length are determined based on the determination method of the laser radar transmitting optical system as described above. The first length is the length of the incident aperture of the Behan prism on the main cross section of the Behan prism, and the second length is the length of the incident aperture of the Behan prism in a direction perpendicular to the main cross section of the Behan prism.

[0121] Optionally, the plano-convex lens may also be replaced by a double convex lens, a meniscus convex lens, an aspherical convex lens, etc. that meet the equal optical path condition.

[0122] An embodiment of the present invention provides a laser radar, which includes the above-mentioned laser radar transmitting optical system.

[0123] Optionally, the transmitting optical system in the laser radar can be used in a laser radar optical path parallel to the transmitting and receiving axes to form a non-coaxial laser radar.

[0124] Optionally, the transmitting optical system in the laser radar can be used in the laser radar optical path where the transmitting and receiving axes coincide with each other to form a coaxial laser radar.

[0125] Figure 8 FIG. 2 shows a schematic diagram of the structure of a device for determining a laser radar transmitting optical system provided by an embodiment of the present invention. Figure 8 The laser radar transmitting optical system determination device 80 provided in an embodiment of the present invention may include a transmitting optical system construction module 810, an acquisition module 820, an incident aperture calculation module 830, an ellipsoid equation calculation module 840, a thickness calculation module 850, and an adjustment module 860.

[0126] The transmitting optical system construction module 810 is used to construct the transmitting optical system, which includes a light source, a Behan prism and a plano-convex lens; the light source is arranged on the incident surface of the Behan prism and is located on the incident light axis of the Behan prism; the plane of the plano-convex lens is in contact with the exit surface of the Behan prism.

[0127] The acquisition module 820 is used to acquire the first refractive index and the second refractive index of the emitting optical system; the first refractive index is the refractive index of the Pechan prism, and the second refractive index is the refractive index of the plano-convex lens.

[0128] The incident aperture calculation module 830 is used to calculate the first length and the second length of the incident aperture of the Behan prism based on the constraint that the edge light can pass through the Behan prism into the plano-convex lens; the first length is the length of the incident aperture on the main section, and the second length is the length of the incident aperture perpendicular to the main section.

[0129] The ellipsoidal surface equation calculation module 840 is used to calculate the ellipsoidal surface equation of the plano-convex lens based on the first refractive index, the second refractive index and the equal optical path principle.

[0130] The thickness calculation module 850 is used to calculate the thickness of the plano-convex lens at the optical axis based on the incident height of the edge light in the plano-convex lens.

[0131] The adjustment module 860 is used to adjust the emission optical system based on the first length, the second length, the ellipsoidal surface equation and the thickness.

[0132] The device for determining the laser radar transmitting optical system provided by the embodiment of the present invention can reduce the size of the system while ensuring the transmitting power, thereby achieving miniaturization of the system.

[0133] In some embodiments, the determination device 80 of the laser radar transmitting optical system also includes a first constraint module, which is used to calculate the first constraint between the first half divergence angle and the first refractive index based on the total reflection condition of the Behan prism in the main cross-section direction. Based on the total reflection condition of the Behan prism in the direction perpendicular to the main cross-section, the second constraint between the second half divergence angle and the first refractive index is calculated. Among them, the first half divergence angle is the half divergence angle of the light source parallel to the main interface of the Behan prism, and the second half divergence angle is the half divergence angle of the light source perpendicular to the main cross-section of the Behan prism to determine the light source and the Behan prism that meet the first constraint and the second constraint.

[0134] In some embodiments, the laser radar transmitting optical system determining device 80 further includes a second constraint module for calculating a third constraint condition between the first half divergence angle and the first refractive index based on the geometric properties of the Behan prism, and determining a light source and a Behan prism that satisfy the third constraint condition.

[0135] In some embodiments, the incident aperture calculation module 830 is specifically used to: Calculate the minimum value of the second length; where α v is the second half divergence angle, b is the second length, L is the distance of the light beam along the optical axis in the Bihan prism, n 1 The minimum value of the second length is taken as the second length.

[0136] In some embodiments, the ellipsoid equation includes: Wherein, x′ and y′ are the coordinate values ​​of the ellipsoidal surface in the direction of the main cross section of the Behan prism, n is the first refractive index and the second refractive index, L is the distance of the light beam in the Behan prism along the optical axis, and d is the thickness of the plano-convex lens at the optical axis.

[0137] In some embodiments, the thickness calculation module 850 is specifically used to: calculate a first lower limit value of the thickness based on the thickness constraint condition in the main cross-section direction. Calculate a second lower limit value of the thickness based on the thickness constraint condition perpendicular to the main cross-section direction. The larger value of the first lower limit value and the second lower limit value is used as the thickness of the plano-convex lens at the optical axis.

[0138] Thickness constraints in the main section direction include:

[0139] Thickness constraints in the direction perpendicular to the main section include:

[0140] Wherein, d is the thickness of the plano-convex lens at the optical axis, n is the first refractive index and the second refractive index, L is the distance of the light beam in the Bihan prism along the optical axis, a is the first length, and b is the second length.

[0141] Fig. 9 FIG. 1 is a schematic diagram of an electronic device provided by an embodiment of the present invention. Fig. 9 As shown, the electronic device 90 of this embodiment includes: a processor 900, a memory 910, and a computer program 920 stored in the memory 910 and executable on the processor 900, such as a design program for a laser radar transmitting optical system. When the processor 90 executes the computer program 920, the steps in the above-mentioned various laser radar transmitting optical system determination method embodiments are implemented, such as Figure 2 Alternatively, when the processor 900 executes the computer program 920, the functions of each module / unit in the above-mentioned device embodiments are implemented, for example Figure 8 Functions of modules 810 to 860 are shown.

[0142] Exemplarily, the computer program 920 may be divided into one or more modules / units, which are stored in the memory 910 and executed by the processor 900 to complete the present invention. The one or more modules / units may be a series of computer program instruction segments capable of completing specific functions, which are used to describe the execution process of the computer program 920 in the electronic device 90. For example, the computer program 920 may be divided into an emission optical system building module, an acquisition module, an incident aperture calculation module, an ellipsoid equation calculation module, a thickness calculation module, and an adjustment module.

[0143] The electronic device 90 may be a computing device such as a desktop computer, a notebook, a PDA, or a cloud server. The electronic device may include, but is not limited to, a processor 900 and a memory 910. Those skilled in the art will appreciate that Fig. 9It is only an example of the electronic device 90 and does not constitute a limitation of the electronic device 90. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the electronic device may also include input and output devices, network access devices, buses, etc.

[0144] The processor 900 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0145] The memory 910 may be an internal storage unit of the electronic device 90, such as a hard disk or memory of the electronic device 90. The memory 910 may also be an external storage device of the electronic device 90, such as a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. equipped on the electronic device 90. Further, the memory 910 may also include both an internal storage unit of the electronic device 90 and an external storage device. The memory 910 is used to store the computer program and other programs and data required by the electronic device. The memory 910 may also be used to temporarily store data that has been output or is to be output.

[0146] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0147] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0148] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0149] In the embodiments provided by the present invention, it should be understood that the disclosed devices / electronic devices and methods can be implemented in other ways. For example, the device / electronic device embodiments described above are only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0150] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0151] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0152] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. . Wherein, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0153] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A method for determining a laser radar transmitting optical system, characterized in that: include: Constructing an emission optical system, the emission optical system comprising a light source, a Behan prism and a plano-convex lens; the light source is arranged on the incident surface of the Behan prism and is located on the incident light axis of the Behan prism; the plane of the plano-convex lens is in contact with the exit surface of the Behan prism; Acquire a first refractive index and a second refractive index of the emitting optical system; the first refractive index is the refractive index of the Behan prism, and the second refractive index is the refractive index of the plano-convex lens; Based on the constraint that the edge light can pass through the Byehan prism and enter the plano-convex lens, the first length and the second length of the incident aperture of the Byehan prism are calculated; the first length is the length of the incident aperture on the main cross section of the Byehan prism; the second length is the length of the incident aperture perpendicular to the main cross section; Based on the first refractive index, the second refractive index and the principle of equal optical path, calculating the ellipsoidal surface equation of the plano-convex lens; Calculating the thickness of the plano-convex lens at the optical axis based on the incident height of the marginal light in the plano-convex lens; The emission optical system is adjusted based on the first length, the second length, the ellipsoidal surface equation, and the thickness.

2. The method for determining the laser radar transmitting optical system according to claim 1, characterized in that: Before constructing the emission optical system consisting of a light source, a Pehan prism and a plano-convex lens, the method comprises: Based on the total reflection condition of the Behan prism in the direction of the main cross section, a first constraint condition between a first half divergence angle and the first refractive index is calculated; the first half divergence angle is a half divergence angle of a light source parallel to the main cross section of the Behan prism; Based on the total reflection condition of the Behan prism in the direction perpendicular to the main cross-section, calculate the second constraint between the second half divergence angle and the first refractive index; the second half divergence angle is the half divergence angle of the light source perpendicular to the main cross-section of the Behan prism; determine the light source and the Behan prism that satisfy the first constraint and the second constraint.

3. The method for determining the laser radar transmitting optical system according to claim 2, characterized in that: Before constructing the emission optical system consisting of a light source, a Pehan prism and a plano-convex lens, the method comprises: Calculating a third constraint between the first half divergence angle and the first refractive index based on the geometric properties of the Behan prism; A light source and a Bihan prism satisfying the third constraint condition are determined.

4. The method for determining the laser radar transmitting optical system according to claim 2, characterized in that: The calculating the second length of the incident aperture of the Behan prism based on the constraint that the edge light can pass through the Behan prism and enter the plano-convex lens comprises: according to Calculate the minimum value of the second length; where α v is the second half divergence angle, b is the second length, L is the distance of the light beam along the optical axis in the Bihan prism, and n1 is the first refractive index; The minimum value of the second lengths is taken as the second length.

5. The method for determining the laser radar transmitting optical system according to claim 1, characterized in that: The first refractive index is equal to the second refractive index, and the ellipsoidal surface equation includes: Wherein, x′ and y′ are the coordinate values ​​of the ellipsoidal surface of the plano-convex lens in the direction of the main cross section of the Behan prism, n is the first refractive index, L is the distance of the light beam in the Behan prism along the optical axis, and d is the thickness of the plano-convex lens at the optical axis.

6. The method for determining the laser radar transmitting optical system according to claim 5, characterized in that: The step of calculating the thickness of the plano-convex lens at the optical axis based on the incident height of the edge light comprises: Calculate a first lower limit value of the thickness based on a thickness constraint condition in the main cross-sectional direction; Calculating a second lower limit value of the thickness based on a thickness constraint condition in a direction perpendicular to the main cross section; The larger value between the first lower limit value and the second lower limit value is used as the thickness of the plano-convex lens at the optical axis.

7. The method for determining the laser radar transmitting optical system according to claim 6, characterized in that: The thickness constraints in the main cross-section direction include: The thickness constraints in the direction perpendicular to the main section include: Wherein, d is the thickness of the plano-convex lens at the optical axis, n is the first refractive index, L is the distance of the light beam in the Bihan prism along the optical axis, a is the first length, and b is the second length.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 7 is implemented.

9. A laser radar transmitting optical system, characterized in that: It comprises a light source, a Behan prism and a plano-convex lens; the light source is arranged on the incident surface of the Behan prism and is located on the incident light axis of the Behan prism; the plane of the plano-convex lens is in contact with the exit surface of the Behan prism; The ellipsoidal equation of the plano-convex lens, the thickness of the plano-convex lens at the optical axis, the first length and the second length are determined based on the method described in any one of claims 1 to 7, the first length is the length of the incident aperture of the Byehan prism on the main cross-section of the Byehan prism, and the second length is the length of the incident aperture of the Byehan prism in a direction perpendicular to the main cross-section of the Byehan prism.

10. A laser radar, comprising the laser radar transmitting optical system as claimed in claim 9.

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