CN115922754A

CN115922754A - Panoramic solid-state laser radar and mobile robot navigation system

Info

Publication number: CN115922754A
Application number: CN202211524601.3A
Authority: CN
Inventors: 李安; 陈驰; 张莉萍; 鲁亚东
Original assignee: Ansijiang Technology Nanjing Co ltd
Current assignee: Ansijiang Technology Nanjing Co ltd
Priority date: 2022-11-30
Filing date: 2022-11-30
Publication date: 2023-04-07

Abstract

The embodiment of the invention discloses a panoramic solid-state laser radar and a mobile robot navigation system, wherein the laser radar comprises a plurality of dtof modules, the dtof modules are arranged on a first plane and are sequentially arranged along the circumference, the optical axes of the dtof modules face different radial directions respectively, the dtof modules comprise laser projectors and laser receivers, the laser projectors emit linear laser beams parallel to the first plane, and the view field ranges of two adjacent laser projectors on the first plane are at least mutually connected. According to the embodiment of the invention, a plurality of dtof modules are simultaneously used in the panoramic solid-state laser radar, the environment distance information of 360-degree full visual angle around the mobile robot can be generated in an image splicing mode, a mechanical rotating part is not required to be arranged, and a laser projector and a laser receiver are not required to be driven by the rotation of a motor, so that the production cost is reduced, the stability of the structure is improved, and the service life of the whole laser transceiving module is prolonged.

Description

Panoramic solid-state laser radar and mobile robot navigation system

Technical Field

The embodiment of the invention relates to the technical field of intelligent robots, in particular to a panoramic solid-state laser radar and a mobile robot navigation system.

Background

With the rapid development of machine intelligence, more and more mobile robots are applied to industrial production and daily life of people, such as automatic navigation intelligent transfer robots, floor sweeping robots, and the like, wherein navigation is an important subject of research in the field of mobile robots at present, and for better completion of tasks, a precise and rapid navigation system is required for generating an environment map of the mobile robots, determining position information of the mobile robots, planning an optimal working path according to understanding of the environment map, and improving working efficiency.

Currently, three types of navigation are mainly available in the market, which can be divided into inertial navigation, visual navigation and laser navigation, wherein laser navigation is a navigation technology adopted by most mobile robots in the current market. The laser navigation is generally implemented by arranging a raised laser transceiver module at the head of a mobile robot, driving a transmitting module to rotate at a high speed by 360 degrees through a mechanical rotating part, projecting a punctiform laser beam to the periphery, receiving an echo signal reflected by an object through a receiving module, and determining the distance between the mobile robot and the object in the surrounding environment by utilizing a triangular ranging principle, thereby generating an environment map to implement a navigation function. However, the distance measurement navigation method has the following problems:

1) The mechanical rotating part is easy to wear and has poor structural stability, so that the service life of the whole laser transceiving module is influenced;

2) The rotation of the laser transceiving module is realized by a corresponding rotating structure and a motor, the cost and the volume of the motor are large, the volume and the cost of the whole laser transceiving module are increased, the miniaturization and cost reduction design of a system are not facilitated, and the stability of a ranging system can be influenced by ranging in a rotating mode;

3) In practical use, due to the fact that the whole laser transceiver module has heavy rotating load and the inherent property of a motor, the scanning time is long, so that the frame rate is low, the output frequency of a depth map of the rotating 360-degree laser transceiver module can only reach 20hz to the maximum extent, navigation of a scene with a fast moving object is not facilitated, and the use scene is limited;

4) According to the distance measuring system based on the triangulation distance measuring principle, the larger the distance between the transmitting module and the receiving module is (the larger the base line distance is), the longer the distance which can be measured accurately is, but the larger the base line distance is, the larger the size corresponding to the whole distance measuring system is, the larger the base line distance is, the general measurement base line distance is limited, so that the accurate distance measuring range of the whole distance measuring system is limited, if the distance can only reach ten meters, the distance measuring system is not beneficial to navigation application of a long-distance scene.

Disclosure of Invention

The embodiment of the invention provides a panoramic solid-state laser radar and a mobile robot navigation system, which aim to solve the technical problem in the distance measurement navigation mode.

In a first aspect, an embodiment of the present invention provides a panoramic solid state laser radar, including multiple dtof modules;

the plurality of dtof modules are arranged on the first plane and are sequentially arranged along the circumference, and optical axes of the plurality of dtof modules face to different radial directions respectively;

the dtof module comprises a laser projector and a laser receiver, the laser projector emits a linear laser beam parallel to the first plane, and the view field ranges of two adjacent laser projectors on the first plane are at least connected with each other.

Optionally, the laser projector includes a laser light source, a collimating unit and a diffusing unit, and the collimating unit and the diffusing unit are respectively disposed on an optical path of an outgoing laser beam of the laser light source;

the collimating unit is used for collimating the emergent laser beam at least in a first direction, and the diffusing unit is used for diffusing the emergent laser beam in a second direction;

wherein the first direction is perpendicular to the first plane and the second direction is parallel to the first plane.

Optionally, the collimating unit comprises a cylindrical lens, an axial meridian of the cylindrical lens extending along the second direction, a direction of extension of a power meridian being perpendicular to the second direction; the laser light source is positioned on the focal plane of the cylindrical lens; the diffusion unit comprises a shaping diffusion sheet;

or, the collimating unit includes a collimating lens, and the collimating lens collimates the emergent laser beam in any direction perpendicular to the emergent laser beam; the diffusion unit includes any one of a wave mirror and a powell lens.

Optionally, the laser light source includes a laser chip, and the diffusion unit is attached to a light emitting surface of the laser chip.

Optionally, the laser projector comprises a laser light source and a first integrated beam shaping unit, the first integrated beam shaping unit being arranged on an optical path of an outgoing laser beam of the laser light source;

the first integrated beam shaping unit is used for collimating the emergent laser beam in a first direction and diffusing the emergent laser beam in a second direction;

Optionally, the first integrated beam shaping unit comprises a first surface and a second surface which are mutually deviated, and the second surface is positioned on one side of the first surface far away from the laser light source;

the first surface is for collimating the outgoing laser beam in the first direction, and the second surface is for diffusing the outgoing laser beam in the second direction; the first surface is one of a Fresnel micro-structure surface and a micro-lens array surface, and the second surface is a diffusion micro-structure surface;

or the first surface is used for collimating the emergent laser beam in any direction perpendicular to the emergent laser beam, and the second surface is used for diffusing the emergent laser beam in the second direction; the first surface is one of a Fresnel microstructure surface and a micro-lens array surface, and the second surface is one of a wavy surface and a ridge surface.

Optionally, the laser projector includes a laser light source, a collimating unit and a second integrated beam shaping unit, where the collimating unit and the second integrated beam shaping unit are respectively disposed on an optical path of an outgoing laser beam of the laser light source;

the collimating unit is used for collimating the emergent laser beam at least in a first direction, and the second integrated beam shaping unit is used for diffusing the emergent laser beam twice in a second direction;

Optionally, the second integrated beam shaping unit comprises a third surface and a fourth surface facing away from each other, the fourth surface being located on a side of the third surface away from the laser light source;

the third surface is used for diffusing the emergent laser beam in the second direction in a first stage, and the fourth surface is used for diffusing the emergent laser beam in the second direction in a second stage;

the collimation unit comprises a collimation lens, and the collimation lens collimates the emergent laser beam in any direction vertical to the emergent laser beam; the third surface is a wavy surface or a ridge surface, and the fourth surface is an inwards concave cylindrical surface;

or, the collimating unit includes a cylindrical lens, an axial meridian of the cylindrical lens extending in the second direction, an extending direction of a power meridian being perpendicular to the second direction; the laser light source is positioned on the focal plane of the cylindrical lens; the third surface is a diffusion microstructure surface, and the fourth surface is an inner concave cylindrical surface.

Optionally, the collimating unit is the collimating lens;

the laser projector also comprises a telescope unit which is arranged on the light path of the emergent light beam of the laser light source and behind the collimating lens;

the telescope unit is used for expanding the emergent laser beams in the second direction.

Optionally, the laser projector comprises a laser light source, and the laser light source comprises any one of a vertical cavity surface emitting laser, an edge emitting laser, and a horizontal cavity surface emitting laser.

Optionally, the laser light source is a vertical cavity surface emitting laser;

the laser projector comprises at least one linear array laser light source, the linear array laser light source comprises a plurality of laser light emitting points which are sequentially arranged along a first direction, and the at least one linear array laser light source is sequentially arranged along a second direction;

Optionally, the laser light source is a horizontal cavity surface emitting laser;

the laser projector comprises a plurality of horizontal cavity surface emitting lasers which are sequentially arranged along a second direction; wherein the second direction is parallel to the first plane.

Optionally, the laser receiver includes an imaging chip, a filtering unit and an imaging lens unit, and the filtering unit and the imaging lens unit are respectively disposed on a receiving optical path of the imaging chip;

the light filtering unit is used for filtering at least part of light rays with wavelengths not the light rays emitted by the laser projector, and the imaging lens unit is used for imaging reflected light formed by the externally reflected light rays emitted by the laser projector on the imaging chip;

the relative illuminance spatial distribution of the imaging lens unit is opposite to the light intensity spatial distribution trend of the laser projector.

In a second aspect, an embodiment of the present invention further provides a mobile robot navigation system, including the panoramic solid-state lidar according to any one of the first aspects.

The embodiment of the invention provides a panoramic solid-state laser radar and a mobile robot navigation system, wherein the panoramic solid-state laser radar comprises a plurality of dtof modules, the dtof modules are arranged on a first plane and are sequentially arranged along the circumference, the optical axes of the dtof modules face different radial directions respectively, the dtof modules comprise laser projectors and laser receivers, the laser projectors emit linear laser beams parallel to the first plane, and the view field ranges of two adjacent laser projectors on the first plane are at least mutually connected. The embodiment of the invention simultaneously uses a plurality of dtof modules in the panoramic solid-state laser radar, does not need to arrange a mechanical rotating part, improves the structural stability, prolongs the service life of the whole panoramic solid-state laser radar, does not need to increase an additional motor to drive the dtof modules to rotate, is favorable for the miniaturization design of the whole panoramic solid-state laser radar, reduces the production cost, improves the frame rate of the environmental depth image output by the panoramic solid-state laser radar, can generate the environmental distance information of 360 degrees of full field around the mobile robot in an image splicing mode, can be applied to the navigation scene with a fast moving object, adopts the ranging principle of direct flight time, enlarges the accurate measurement range of the panoramic solid-state laser radar, and can be applied to the navigation scene of remote measurement.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is an exploded view of a panoramic solid-state lidar according to an embodiment of the present invention;

FIG. 2 is a top view of a panoramic solid-state lidar according to an embodiment of the present invention;

fig. 3 is a schematic diagram of a working flow of a panoramic solid-state lidar according to an embodiment of the present invention;

FIGS. 4-5 are schematic diagrams of optical paths of a dtof module laser projector at different viewing angles according to an embodiment of the invention;

FIG. 6 is a schematic diagram of an optical path of another dtof module laser projector according to an embodiment of the invention;

FIG. 7 is a schematic diagram of an optical path of a dtof module laser projector according to an embodiment of the invention;

FIGS. 8-9 are schematic diagrams of optical paths of another dtof module laser projector at different viewing angles according to an embodiment of the invention;

FIG. 10 is a schematic diagram of an optical path of a dtof module laser projector according to an embodiment of the invention;

FIG. 11 is a schematic diagram of an optical path of another dtof module laser projector according to an embodiment of the invention;

FIG. 12 is a schematic diagram of an optical path of a dtof module laser projector according to an embodiment of the invention;

FIG. 13 is a schematic diagram of an optical path of another dtof module laser projector according to an embodiment of the invention;

FIG. 14 is a schematic diagram of an optical path of a dtof module laser projector according to an embodiment of the invention;

FIG. 15 is a schematic diagram of an optical path of a dtof module laser projector according to an embodiment of the invention;

FIG. 16 is a schematic diagram of an optical path of another dtof module laser projector according to an embodiment of the invention;

FIG. 17 is a schematic diagram of an optical path of a dtof module laser projector according to an embodiment of the invention;

FIG. 18 is a schematic diagram of an optical path of a dtof module laser projector according to an embodiment of the invention;

FIG. 19 is a schematic diagram of an optical path of a dtof module laser projector according to an embodiment of the invention;

FIG. 20 is a schematic diagram of an optical path of another dtof module laser projector according to an embodiment of the invention;

FIG. 21 is a schematic structural diagram of a laser source of a dtof module according to an embodiment of the present invention;

FIG. 22 is a schematic structural diagram of another dtof module laser source according to an embodiment of the invention;

FIG. 23 is a schematic view of the optical path corresponding to the laser source in the dtof module shown in FIG. 22;

FIG. 24 is a schematic structural diagram of a laser source of a dtof module according to an embodiment of the present invention;

FIG. 25 is a schematic diagram of an optical path corresponding to a further dtof module laser projector according to an embodiment of the present invention;

FIG. 26 is a schematic diagram of an optical path of a dtof module laser receiver according to an embodiment of the present invention;

FIG. 27 is a graph showing the luminance distribution of a linear laser beam emitted from a dtof module laser projector according to an embodiment of the present invention;

fig. 28 is a diagram illustrating a relative illuminance distribution curve of an imaging unit of a dtof module laser receiver according to an embodiment of the invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some structures related to the present invention are shown in the drawings, not all of them.

The terminology used in the embodiments of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. It should be noted that the terms "upper", "lower", "left", "right", and the like used in the description of the embodiments of the present invention are used in the angle shown in the drawings, and should not be construed as limiting the embodiments of the present invention. In addition, in this context, it is also to be understood that when an element is referred to as being "on" or "under" another element, it can be directly formed on "or" under "the other element or be indirectly formed on" or "under" the other element through an intermediate element. The terms "first," "second," and the like, are used for descriptive purposes only and are not intended to denote any order, quantity, or importance, but rather are used to distinguish one element from another. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The term "include" and variations thereof as used herein are intended to be open-ended, i.e., "including but not limited to". The term "based on" is "based, at least in part, on". The term "one embodiment" means "at least one embodiment".

It should be noted that the terms "first", "second", etc. mentioned in the present invention are only used for distinguishing the corresponding contents, and are not used for limiting the order or interdependence relationship.

It is noted that references to "a" or "an" or "the" modification(s) in the present invention are intended to be illustrative rather than limiting and that those skilled in the art will understand that reference to "one or more" unless the context clearly indicates otherwise.

Fig. 1 is an exploded view of a panoramic solid-state lidar according to an embodiment of the present invention, and fig. 2 is a top view of the panoramic solid-state lidar according to an embodiment of the present invention, as shown in fig. 1 and fig. 2, the panoramic solid-state lidar according to an embodiment of the present invention includes a plurality of dtof modules 130; the plurality of dtof modules 130 are arranged on the first plane and are sequentially arranged along the circumference, and the optical axes of the plurality of dtof modules 130 face different radial directions respectively; the dtof module 130 includes a laser projector 131 and a laser receiver 132, the laser projector 131 emits a line laser beam parallel to the first plane, and the field of view ranges of two adjacent laser projectors 131 on the first plane are at least connected to each other.

Specifically, dtof directly measures the flight time of an optical pulse when the optical pulse is sent to and received through a single photon detection technology, distance measurement can be achieved according to the principle that the light speed is not changed, the depth distance information of an object in the environment where the mobile robot is located is measured by adopting the direct flight time distance measuring principle of the dtof module 130, and compared with the triangular distance measuring principle, the direct flight time distance measuring principle cannot cause the worse precision and the longer measurable distance due to the longer distance of the object. The dtof module 130 includes a laser projector 131 and a laser receiver 132, the laser projector 131 and the laser receiver 132 are electrically connected to the circuit board of the dtof module 130, and the laser projector 131 is closely attached to the side of the laser receiver 132. The plurality of dtof modules 130 are arranged on a first plane and are arranged in sequence along the circumference, wherein the first plane is a horizontal plane on which the plurality of dtof modules 130 are placed, the horizontal heights of the plurality of dtof modules 130 are ensured to be consistent, the optical axes of the plurality of dtof modules 130 face different radial directions, and the plurality of dtof modules 130 are combined for use. The laser projectors 131 emit linear laser beams parallel to the first plane, and the field ranges of two adjacent laser projectors 131 on the first plane may be connected to each other exactly or overlapped with each other, so that the environmental distance information of a 360-degree full field of view is obtained by means of image stitching.

In addition, the panoramic solid-state lidar further includes a stationary housing 110, a system motherboard 120, and a system protective enclosure 140. The dtof module 130 is fixed on the fixed housing 110 by glue, and the dtof module 130 is connected to the system board 120 by the flexible board traces. The system motherboard 120 is a circuit motherboard of the whole panoramic solid-state laser radar system, and includes a control processing module, a data processing module, an interface module, and the like, and the system motherboard 120 is fixed on the fixed housing 110 by glue or a structure buckle. In the operation process of the panoramic solid-state laser radar, the fixed shell 110 and the system protection shell 140 are buckled or bonded together, so that the system main board 120 and the dtof module 130 can be protected from external environmental pollution. The system protective enclosure 140 is provided with windows transparent to the laser light source at the positions of the fields of view of the corresponding laser projector 131 and laser receiver 132. It should be noted that the shape of the fixed casing 110 and the system protection casing 140 may be square, circular, or other shapes, which is not limited in the embodiment of the present invention, and the circular shape of the fixed casing 110 and the system protection casing 140 shown in fig. 1 and fig. 2 is only an example.

Specifically, fig. 3 is a schematic flowchart of a working process of a panoramic solid-state laser radar according to an embodiment of the present invention, as shown in fig. 3, the control processing module 20 may be an independent dedicated circuit, exemplarily, the control processing module 20 may be a dedicated SOC chip, an FPGA chip, an ASIC chip, or the like, and the control processing module 20 may also be a general processing circuit. As shown in fig. 3, four dtof modules 130 are illustrated, but not limited thereto, the number of dtof modules 130 is determined according to the actual operation effect, so as to ensure that the panoramic solid-state lidar generates environment distance information of 360 ° of full field of view, and exemplarily, the panoramic solid-state lidar may also employ three dtof modules 130. The four paths of synchronization signals output by the control processing module 20 are respectively sent to the four SPAD chips, so that clock synchronization is maintained between the four SPAD chips. Illustratively, when the SPAD chip 211 receives the clock signal, the SPAD pixels at the corresponding positions on the SPAD chip 211 are synchronously in the geiger mode state (working state), the TDCs on the SPAD chip 211 start timing, and synchronously output the trigger signals to the laser drivers 212 respectively corresponding to the SPAD chip 211. The laser driver 212 drives the laser projector 131 to emit a line laser pulse with a certain frequency, when the emitted line laser beam hits an object, the line laser beam is reflected to the laser receiver 132 to be received by the object, the SPAD pixels receive photons to generate an avalanche pulse signal in response, the avalanche pulse signal is output to the TDC on the SPAD chip 211, and the TDC stops timing. The control processing module 20 may calculate the environmental depth distance information of the object by calculating the time difference between the time when the laser is emitted and the time when the laser is reflected by the object and then is responded by the SPAD pixel.

When the panoramic solid-state lidar employs four dtof modules 130, the field angles of the line laser beams emitted by the laser projector 131 are all H-90 ° horizontal and V-1 ° vertical, the field angle in the horizontal direction may also be slightly larger than 90 °, and the field angle in the vertical direction is generally required to be smaller than 1.5 °. The smaller the angle of field angle in the vertical direction is, the more concentrated the laser energy is, and the longer-distance scene measurement is facilitated. The field angle area of the laser receiver 132 coincides with the area of the line laser beam projected by the laser projector 131, so that the horizontal field angle of the image formed by the laser receiver 132 is greater than or equal to 90 °, the four dtof modules 130 are used simultaneously, four environmental depth images can be obtained simultaneously when distance measurement is completed once, the distance information of the four environmental depth images can be synchronously output to the control processing module 20, and the environmental depth images are spliced through data processing to obtain the environmental depth distance information of 360-degree full field. In addition, when the panoramic solid-state laser radar adopts three dtof modules 130, the horizontal field angle of the image formed by the laser receiver 132 is ensured to be greater than or equal to 120 degrees, the three dtof modules 130 are used simultaneously, three environmental depth images can be obtained simultaneously every time distance measurement is completed, distance information of the three environmental depth images can be synchronously output to the control processing module 20, and the environmental depth images are spliced through data processing to obtain 360-degree full-field environmental depth distance information.

The embodiment of the invention provides a panoramic solid-state laser radar and a mobile robot navigation system, wherein the panoramic solid-state laser radar comprises a plurality of dtof modules, the dtof modules are arranged on a first plane and are sequentially arranged along the circumference, the optical axes of the dtof modules face different radial directions respectively, the dtof modules comprise laser projectors and laser receivers, the laser projectors emit linear laser beams parallel to the first plane, and the view field ranges of two adjacent laser projectors on the first plane are at least mutually connected. The embodiment of the invention simultaneously uses a plurality of dtof modules in the panoramic solid-state laser radar, does not need to arrange a mechanical rotating part, improves the stability of the structure, prolongs the service life of the whole panoramic solid-state laser radar, does not need to increase an additional motor to drive the dtof modules to rotate, is beneficial to the miniaturization design of the whole panoramic solid-state laser radar, reduces the production cost, improves the frame rate of an environment depth image output by the panoramic solid-state laser radar, can generate 360-degree full-view-field environment distance information around a mobile robot in an image splicing mode, can be applied to a navigation scene with a fast moving object, and adopts the direct flight time ranging principle, enlarges the accurate measurement range of the panoramic solid-state laser radar and can be applied to a navigation scene with long-distance measurement.

In the following embodiments, the detailed structure of the laser projector 131 of the dtof module 130 will be described in detail, and fig. 4-5 are schematic diagrams of the optical paths of the dtof module laser projector provided by the embodiments of the invention at different viewing angles, referring to fig. 4 and 5.

Alternatively, the laser projector 131 includes a laser light source 150, a collimating unit 160, and a diffusing unit 170, the collimating unit 160 and the diffusing unit 170 being respectively disposed on optical paths of outgoing laser beams of the laser light source 150; a collimating unit 160 for collimating the outgoing laser beam at least in the first direction X, and a diffusing unit 170 for diffusing the outgoing laser beam in the second direction Y; wherein the first direction X is perpendicular to a first plane (the plane shown by YOZ in fig. 4 and 5) and the second direction Y is parallel to the first plane.

Specifically, the wavelength of the laser beam emitted from the laser light source 150 is an infrared band, and illustratively, the wavelength may be 850nm, 905nm, 940nm, 1550nm, or the like. The collimating unit 160 may be composed of one or more cylindrical lenses, or may be composed of one or more collimating lenses, and the lenses may be made of glass, resin, or the like. The microstructure surface of the diffusion unit 170 may be manufactured by a direct etching, laser direct writing or plasma direct writing technique on a substrate, or may be manufactured by a nanoimprint technique after a photoresist is spin-coated on the substrate, or may be manufactured by a precision injection molding process, wherein the substrate corresponding to the microstructure surface of the diffusion unit 170 may be a glass material (such as quartz), a plastic material (such as PC, PMMA) or the like. The collimating unit 160 and the diffusing unit 170 are respectively disposed on the light path of the outgoing laser beam of the laser light source 150, the collimating unit 160 is configured to collimate the outgoing laser beam in at least a first direction X, the first direction X is perpendicular to a first plane, it is ensured that the laser receiver 132 can receive image distance information of the same horizontal plane, the diffusing unit 170 is configured to diffuse the outgoing laser beam in a second direction Y, the second direction Y is parallel to the first plane, and it is ensured that the distance information of the environmental depth image output by the plurality of dtof modules 130 can obtain environmental depth distance information of 360 ° full field after being spliced.

Alternatively, with continued reference to fig. 4 and 5, the collimating unit 160 comprises a cylindrical lens, an axial meridian 1601 of the cylindrical lens extending in the second direction Y, a direction of extension of the power meridian 1602 being perpendicular to the second direction Y; the laser light source 150 is located at the focal plane of the cylindrical lens; the diffusion unit 170 includes a shaping diffuser; alternatively, the collimating unit 160 includes a collimating lens that collimates the outgoing laser beam in any direction perpendicular to the outgoing laser beam; the diffusion unit 170 includes any one of a wave mirror and a powell lens.

Specifically, the collimating unit 160 may be a cylindrical lens, an axial meridian 1601 of the cylindrical lens extends along a second direction Y in the viewing angle of fig. 4, the second direction Y is parallel to the first plane, and an extending direction of a dioptric force meridian 1602 in the viewing angle of fig. 5 is perpendicular to the second direction Y, and the placing position of the collimating unit 160 may be defined such that the cylindrical lens collimates the laser beam emitted from the laser light source 150 in at least the first direction X, and the laser light source 150 is located at the focal plane of the cylindrical lens. Alternatively, the collimating unit 160 may be a collimating lens, and the collimating lens may collimate in any direction perpendicular to the laser beam emitted from the laser light source 150.

With continued reference to fig. 4 and 5, in one embodiment, the collimating unit 160 is a cylindrical lens and the diffusing unit 170 is a shaping diffuser 1701. The laser beam emitted by the laser light source 150 has a certain divergence angle, the laser beams are overlapped on the incident plane of the cylindrical lens to form a strip-shaped light spot, the long side direction of the strip-shaped light spot is parallel to the second direction Y, the short side direction of the strip-shaped light spot is parallel to the first direction X, the axial meridian 1601 of the cylindrical lens extends along the second direction Y, and the extension direction of the refractive power meridian 1602 is perpendicular to the second direction Y, so that the cylindrical lens can collimate the laser beam into parallel light in the first direction X, but the cylindrical lens cannot collimate the laser beam in the second direction Y, and the divergence angle of the laser beam in the second direction Y cannot be changed. When diffuser unit 170 is a shaping diffuser 1701, shaping diffuser 1701 does not process the laser beam in first direction X, the beam propagation direction and beam width of the laser beam in first direction X are kept unchanged, and the laser beam in first direction X is emitted in parallel, but shaping diffuser 1701 may perform light homogenizing and beam expanding processing on the laser beam in second direction Y, and finally a linear laser beam parallel to the first plane is emitted, the long side direction of the linear laser beam is parallel to second direction Y, and the short side direction of the linear laser beam is parallel to first direction X.

It should be noted that, a cylindrical lens is adopted as the collimating unit 160 to collimate the outgoing laser beam in the first direction X, the image height of the outgoing laser beam in the first direction X is small, the collimation difficulty is low, and the outgoing laser beam does not need to be collimated in the second direction Y, so that the design difficulty of the collimating unit 160 can be reduced. The dodging and beam expanding processing of the laser beam is realized by using the shaping and diffusing sheet 1701 as the diffusing unit 170, the beam width of the laser beam is not changed in the first direction X, the dodging and beam expanding processing of the laser beam is performed in the second direction Y, and the line laser beam with a larger angle of view is obtained.

Fig. 6 is a schematic diagram of an optical path of another dtof module laser projector according to an embodiment of the invention, as shown in fig. 6, in another embodiment, the collimating unit 160 is a collimating lens, and the diffusing unit 170 is a wave mirror 1702. The wave mirror 1702 can be understood as a plurality of cylindrical lenses connected together, the surface shape of the cylindrical lenses can be a spherical surface, a sine/cosine surface, an ellipsoid or other curved shapes, and the corrugation direction of the wave mirror 1702 is perpendicular to the extending direction of the cylindrical surface. The laser beam emitted by the laser light source 150 has a certain divergence angle, the laser beams are overlapped on the incident plane of the collimating lens to form a strip-shaped light spot, the long side direction of the strip-shaped light spot is parallel to the second direction Y, the short side direction of the strip-shaped light spot is parallel to the first direction X, and the ripple direction of the wave mirror 1702 needs to be parallel to the second direction Y, so that the diffusion and the propagation of the laser beam are ensured. The collimator lens serves as a collimating unit 160 collimating the laser beam into parallel light in both the first direction X and the second direction Y. The wave mirror 1702, as the diffusing unit 170, does not change the width of the laser beam in the first direction X, and performs dodging and beam expanding processing on the laser beam in the second direction Y, so as to finally obtain a linear laser beam with a larger field angle for emission.

It should be noted that the ripple direction of the wave mirror 1702 needs to be parallel to the second direction Y, and when the laser beam parallel to the ripple direction of the wave mirror 1702 is incident on the surface of the wave mirror 1702, the surface curvature of the cylindrical lens incident on the wave mirror 1702 is the same for the parallel light beams incident at different positions, and the refraction directions of the parallel light beams incident at different positions are the same, so that the wave mirror 1702 does not change the beam width of the laser beam emitted by the laser light source 150 in the first direction X. When the laser beam perpendicular to the corrugation direction of the wave mirror 1702 is incident on the surface of the wave mirror 1702, because the surface type of the cylindrical lens in the wave mirror 1702 is a curved surface, the refraction directions of the incident parallel beams at different positions are different, and the laser beam diverges in the second direction Y, so that a linear laser beam with better uniformity is formed for emission. Compared with the shaping and diffusing sheet 1701 which is used as the diffusing unit 170 to realize the uniform light beam expanding processing of the laser beam, the wave mirror 1702 utilizes the refraction principle of light to uniformly expand the parallel light beams entering the wave mirror 1702, the light loss generated to light rays is less, and the light spot brightness of the output linear laser beam is higher. In addition, the collimating unit 160 is a collimating lens, which can collimate the outgoing laser beam in both the first direction X and the second direction Y, and the collimating unit 160 is more difficult to design than the collimating unit 160 in the above embodiment that is a cylindrical lens.

Fig. 7 is a schematic diagram of an optical path of another dtof module laser projector according to an embodiment of the invention, as shown in fig. 7, in another embodiment, the collimating unit 160 is a collimating lens, and the diffusing unit 170 is a powell lens 1703. The Bawell lens 1703 is placed on the side of the roof facing the laser source 150, and the top of the roof is generally aspheric, so that the collimated beam can be fanned out and converted into a uniformly distributed linear laser beam. The laser beams emitted by the laser light source 150 have a certain divergence angle, the laser beams are mutually overlapped on the incident plane of the collimating lens to form a strip-shaped light spot, the long side direction of the strip-shaped light spot is parallel to the second direction Y, the short side direction of the strip-shaped light spot is parallel to the first direction X, and the roof surface of the Baville lens 1703 needs to be parallel to the second direction Y, so that the diffusion and the propagation of the laser beams are ensured. The collimator lens serves as a collimating unit 160 collimating the laser beam into parallel light in both the first direction X and the second direction Y. The powell lens 1703 serves as the diffusion unit 170, the width of the laser beam is not changed in the first direction X, the laser beam is subjected to dodging and beam expanding processing in the second direction Y, and finally the linear laser beam with a larger field angle and uniform distribution is obtained and emitted.

Compared with the wave mirror 1702 used as the diffusion unit 170 to implement the uniform beam expansion processing of the laser beam, the wave mirror 1702 is affected by the gaussian distribution of the laser source 150 during use, and the generated linear laser beam has bright middle and dark sides, which affects the uniformity of the linear laser beam. The curved arc top of the Bawell lens 1703 is a complex aspheric curve, and a large amount of spherical aberration can be generated, so that light is redistributed along the linear direction, light rays in the central area are reduced, meanwhile, the light ray intensity at the tail end of the linear direction is increased, and the uniformity of linear laser beams is effectively improved. In addition, the collimating unit 160 is made of a collimating lens, which can collimate the outgoing laser beam in both the first direction X and the second direction Y, and the design difficulty of the collimating unit 160 is greater than that of the collimating unit 160 made of a cylindrical lens in the above embodiments.

Fig. 4-7 are schematic optical path diagrams of three dtof module laser projectors according to an embodiment of the present invention, in which the laser projector 131 includes a laser light source 150, a collimating unit 160, and a diffusing unit 170. The collimating unit 160 may be a cylindrical lens, and the cylindrical lens may collimate the laser beam emitted from the laser light source 150 in the first direction X, in this case, the diffusing unit 170 may be a shaping diffusing sheet 1701, and may perform light homogenizing and beam expanding processing on the laser beam in the second direction Y. Or, the collimating unit 160 may also be a collimating lens, and the collimating lens may collimate the outgoing laser beam in any direction perpendicular to the outgoing laser beam, where the collimating lens may collimate the laser beam emitted by the laser light source 150 in the first direction X and the second direction Y, at this time, the diffusing unit 170 may be a wave mirror 1702, and uniformly expands the parallel light beam incident to the wave mirror 1702, so that the light loss generated to the light ray is less, so that the light spot brightness of the output linear laser beam is higher, and the diffusing unit 170 may also be a powell lens 1703, which may reduce the light ray in the central area, increase the light ray intensity at the end of the linear line, and effectively improve the uniformity of the linear laser beam. It should be noted that when the cylindrical lens is used as the collimating unit 160, the diffusing unit 170 may be a shaping diffusing sheet 1701, and when the diffusing unit 170 is the wave mirror 1702 and/or the powell lens 1703, it is necessary to ensure that the laser beam incident on the wave mirror 1702 and/or the powell lens 1703 is collimated into parallel light in both the first direction X and the second direction Y, and a collimating lens is used as the collimating unit 160, and a cylindrical lens that can only collimate the outgoing laser beam in the first direction X cannot be used as the collimating unit 160. However, since the inner space of the laser projector 131 is limited and a plurality of optical elements exist, the assembly difficulty of the laser projector 131 is increased, which is not favorable for the integration and miniaturization design of the panoramic solid-state lidar system. The following are several constituent structures provided by the embodiments of the present invention to effectively compress the volume of the laser projector 131 and to improve the integration of the laser projector 131.

Fig. 8-9 are schematic diagrams of optical paths of another dtof module laser projector at different viewing angles according to an embodiment of the present invention, as shown in fig. 8 and 9, alternatively, the laser light source 150 includes a laser chip 1501, and the diffusion unit 170 is attached on the light emitting surface of the laser chip 1501.

Specifically, the laser beam emitted from the laser source 150 has a certain divergence angle, and may be a circular spot (e.g., 90 ° by 90 °), or a square spot (e.g., 90 ° by 45 °,90 ° by 30 °). For example, when the laser beam emitted from the laser light source 150 is a circular spot, the laser light source 150 may be a light emitting diode; when the laser beam emitted by the laser light source 150 is a square spot, the laser light source 150 may be composed of a laser chip 1501 and a diffusion unit 170, the diffusion unit 170 may be integrated on the light exit surface of the laser chip 1501 by using a mounting process, the diffusion unit 170 performs light homogenizing and beam expanding processing on the laser beam emitted by the laser chip 1501, the laser chip 1501 and the diffusion unit 170 are used for emitting the square spot as a whole, in addition, the divergence angle of the laser beam emitted by the laser light source 150 in the second direction Y is large, the divergence angle of the laser beam emitted in the first direction X is small, exemplarily, the square spot emitted by the laser light source 150 is 90 ° by 45 °, at this time, the direction of 90 ° is the second direction Y, and the direction of 45 ° is the first direction X. The laser chip 1501 and the diffusion unit 170 are incident to the collimation unit 160 as a square spot emitted by an integrally packaged body, a laser beam is perpendicularly incident to the collimation unit 160 in the first direction X, is collimated by the collimation unit 160 to be a parallel beam to be emitted, and is perpendicularly incident to the collimation unit 160 in the second direction Y, and after passing through the collimation unit 160, the beam propagation direction of the laser beam cannot be changed. The laser chip 1501 and the diffusion unit 170 are used as a whole package, the laser beam emitted by the laser chip 1501 is homogenized and expanded, and then passes through the collimation unit 160, and finally the linear laser beam with a large field angle and uniform distribution is obtained.

Fig. 10 is a schematic optical path diagram of a dtof module laser projector according to an embodiment of the invention, as shown in fig. 10, optionally, the laser projector 131 includes a laser light source 150 and a first integrated beam shaping unit 180, and the first integrated beam shaping unit 180 is disposed on an optical path of an outgoing laser beam of the laser light source 150; the first integrated beam shaping unit 180 is configured to collimate the outgoing laser beam in the first direction X and diffuse the outgoing laser beam in the second direction Y; the first direction X is perpendicular to the first plane, and the second direction Y is parallel to the first plane.

Specifically, the first integrated beam shaping unit 180 is disposed on an optical path of an outgoing laser beam of the laser light source 150, the first integrated beam shaping unit 180 is configured to collimate the outgoing laser beam in a first direction X, the first direction X is perpendicular to a first plane, and it is ensured that the laser receiver 132 can receive image distance information of the same horizontal plane, the first integrated beam shaping unit 180 is further configured to diffuse the outgoing laser beam in a second direction Y, the second direction Y is parallel to the first plane, and it is ensured that distance information of the environment depth image output by the plurality of dtof modules 130 can obtain environment depth distance information of a full field of view of 360 degrees after being spliced.

Optionally, with continued reference to fig. 10, the first integrated beam shaping unit 180 includes a first surface 1801 and a second surface 1802 facing away from each other, the second surface 1802 being located on a side of the first surface 1801 away from the laser light source 150; the first surface 1801 is used for collimating the outgoing laser beam in the first direction X, and the second surface 1802 is used for diffusing the outgoing laser beam in the second direction Y; the first surface 1801 is one of a fresnel microstructure surface and a microlens array surface, and the second surface 1802 is a diffusion microstructure surface; alternatively, the first surface 1801 is used to collimate the outgoing laser beam in an arbitrary direction perpendicular to the outgoing laser beam, and the second surface 1802 is used to diffuse the outgoing laser beam in the second direction Y; the first surface 1801 is one of a fresnel microstructure surface and a microlens array surface, and the second surface 1802 is one of a wavy surface and a ridge surface.

Specifically, the first integrated beam shaping unit 180 includes a first surface 1801 and a second surface 1802 facing away from each other, the second surface 1802 is located on a side of the first surface 1801 away from the laser light source 150, the laser beam emitted from the laser light source 150 is incident on the first surface 1801 of the first integrated beam shaping unit 180, the first surface 1801 may collimate the laser beam in at least a first direction X, the collimated laser beam is emitted through the second surface 1802 of the first integrated beam shaping unit 180, and the second surface 1802 may diffuse the emitted laser beam in a second direction Y. The first integrated beam shaping unit 180 can collimate and diffuse the laser beam emitted from the laser source 150, and integrate the functions of collimation and diffusion into one optical element, thereby effectively reducing the number of optical elements in the laser projector 131, effectively compressing the volume, saving the space, and reducing the production cost of the laser projector 131.

In an embodiment, fig. 11 is a schematic optical path diagram of a dtof module laser projector according to an embodiment of the present invention, and as shown in fig. 11, a first surface 1801 of the first integrated beam shaping unit 180 is a fresnel microstructure surface, and a second surface 1802 of the first integrated beam shaping unit 180 is a diffusion microstructure surface. The first surface 1801 is a fresnel microstructure surface and can collimate laser beams in a first direction X, the fresnel microstructure surface is a cylindrical surface, unlike a conventional fresnel microstructure surface, the fresnel microstructure surface is parallel to the first direction X and extends along a second direction Y, the surface parameters of the fresnel microstructure surface in the second direction Y are not changed, the fresnel microstructure surface only needs to collimate laser beams in the first direction X, and compared with the first surface 1801 which needs to collimate laser beams in the first direction X and the second direction Y, the design difficulty of the fresnel microstructure surface is small. The second surface 1802 is a diffusion microstructure surface and can diffuse and emit laser beams in the second direction Y, the laser beams are subjected to light homogenizing and beam expanding treatment in the second direction Y, linear laser beams parallel to the first plane are finally obtained and emitted, the long side direction of the linear laser beams is parallel to the second direction Y, and the short side direction of the linear laser beams is parallel to the first direction X. In addition, fig. 12 is a schematic optical path diagram of another dtof module laser projector according to an embodiment of the present invention, and as shown in fig. 12, the first surface 1801 of the first integrated beam shaping unit 180 may also be a microlens array surface, which can collimate a laser beam in the first direction X, and the surface of the microlens array surface may be a spherical surface, an aspheric surface, or a free-form surface. The micro lens array surface is connected together by a plurality of cylindrical lenses, an axial meridian of the micro lens array surface extends along a second direction Y, the extending direction of a refractive power meridian is perpendicular to the second direction Y, surface type parameters of the micro lens array surface in the second direction Y are unchanged, the micro lens array surface only needs to collimate laser beams in a first direction X, and compared with a first surface 1801 which needs to collimate the laser beams in the first direction X and the second direction Y, the design difficulty of the micro lens array surface is small.

In another embodiment, fig. 13 is a schematic optical path diagram of a dtof module laser projector according to an embodiment of the present invention, and as shown in fig. 13, a first surface 1801 of the first integrated beam shaping unit 180 is a fresnel microstructure surface, and a second surface 1802 of the first integrated beam shaping unit 180 is a wave surface. In addition, fig. 14 is a schematic optical path diagram of another dtof module laser projector according to an embodiment of the present invention, and as shown in fig. 14, a first surface 1801 of the first integrated beam shaping unit 180 is a microlens array surface, and a second surface 1802 of the first integrated beam shaping unit 180 is a wavy surface. It should be noted that, in both the fresnel microstructure surface and/or the microlens array surface, the laser beam emitted from the laser light source 150 needs to be collimated into parallel beams in the first direction X and the second direction Y, the laser beam collimated by the first surface 1801 of the first integrated beam shaping unit 180 is incident to the second surface 1802 in a wavy shape, the beam width of the laser beam is not changed in the first direction X, and the laser beam is subjected to the light homogenizing and beam expanding treatment in the second direction Y, so that the linear laser beam with a larger field angle and uniform distribution is finally obtained and emitted.

In another embodiment, fig. 15 is a schematic optical path diagram of a dtof module laser projector according to an embodiment of the present invention, and as shown in fig. 15, a first surface 1801 of the first integrated beam shaping unit 180 is a fresnel microstructure surface, and a second surface 1802 of the first integrated beam shaping unit 180 is a roof ridge surface. In addition, fig. 16 is a schematic optical path diagram of another dtof module laser projector according to the embodiment of the invention, and as shown in fig. 16, a first surface 1801 of the first integrated beam shaping unit 180 is a microlens array surface, and a second surface 1802 of the first integrated beam shaping unit 180 is a roof surface. The fresnel microstructure surface and/or the microlens array surface need to collimate the laser beam emitted from the laser light source 150 into parallel beams in the first direction X and the second direction Y, the laser beam collimated by the first surface 1801 of the first integrated beam shaping unit 180 is incident to the second surface 1802 in the shape of a roof, the beam width of the laser beam is not changed in the first direction X, and the laser beam is subjected to light-homogenizing and beam-expanding processing in the second direction Y, so that the linear laser beam with a larger field angle and uniform distribution is finally obtained and emitted.

It should be noted that when the second surface 1802 of the first integrated beam shaping unit 180 is a diffusing microstructure surface, the first surface 1801 of the first integrated beam shaping unit 180 may be one of a fresnel microstructure surface and a microlens array surface, and only the outgoing laser beam needs to be collimated in the first direction X, and when the second surface 1802 of the first integrated beam shaping unit 180 is one of a wave surface and a ridge surface, the first surface 1801 of the first integrated beam shaping unit 180 may still be one of a fresnel microstructure surface and a microlens array surface, but the outgoing laser beam needs to be collimated in any direction perpendicular to the outgoing laser beam, and it is ensured that the outgoing laser beam is collimated in the first direction X and the second direction Y as parallel light.

The diffusion unit 170 shown in fig. 8-9 is attached to the light-emitting surface of the laser chip 1501, so as to effectively compress the volume of the laser projector 131 and save the internal space. The laser projector 131 shown in fig. 10-16 includes a laser light source 150 and a first integrated beam shaping unit 180, and the first surface 1801 and the second surface 1802 of the first integrated beam shaping unit 180 are different structures, so that the number of optical elements used can be reduced, the integration level of the panoramic solid-state lidar system can be improved, the volume of the laser projector 131 can be effectively reduced, and the internal space can be saved.

Fig. 17 is a schematic optical path diagram of a further dtof module laser projector according to an embodiment of the present invention, and as shown in fig. 17, optionally, the laser projector 131 includes a laser source 150, a collimating unit 160 and a second integrated beam shaping unit 190, and the collimating unit 160 and the second integrated beam shaping unit 190 are respectively disposed on the optical path of the outgoing laser beam of the laser source 150; the collimating unit 160 is configured to collimate the outgoing laser beam in at least the first direction X, and the second integrated beam shaping unit 190 is configured to twice diffuse the outgoing laser beam in the second direction Y; the first direction X is perpendicular to the first plane, and the second direction Y is parallel to the first plane.

Specifically, the collimating unit 160 and the second integrated beam shaping unit 190 are respectively disposed on the light path of the outgoing laser beam of the laser light source 150, the collimating unit 160 is configured to collimate the outgoing laser beam in at least a first direction X, the first direction X is perpendicular to the first plane, and it is ensured that the laser receiver 132 can receive image distance information of the same horizontal plane, the second integrated beam shaping unit 190 is configured to diffuse the outgoing laser beam twice in a second direction Y, the second direction Y is parallel to the first plane, and it is ensured that the distance information of the environmental depth image output by the plurality of dtof modules 130 can obtain 360 ° environmental depth distance information of the full field of view after being spliced.

With continued reference to fig. 17, optionally, the second integrated beam-shaping unit 190 includes a third surface 1901 and a fourth surface 1902 facing away from each other, the fourth surface 1902 being located on a side of the third surface 1901 away from the laser light source 150; the third surface 1901 is used for primary diffusion of the outgoing laser beam in the second direction Y, and the fourth surface 1902 is used for secondary diffusion of the outgoing laser beam in the second direction Y; the collimating unit 160 includes a collimating lens that collimates the outgoing laser beam in an arbitrary direction perpendicular to the outgoing laser beam; the third surface 1901 is a wavy surface or a roof surface, and the fourth surface 1902 is an inwardly concave cylindrical surface; alternatively, with continued reference to fig. 19, the optional collimating unit 160 includes a cylindrical lens, an axial meridian 1601 of the cylindrical lens extends along the second direction Y, and an extending direction of a power meridian 1602 is perpendicular to the second direction Y; the laser light source 150 is located at the focal plane of the cylindrical lens; the third surface 1901 is a diffusion microstructure surface and the fourth surface 1902 is an inwardly concave cylindrical surface.

Specifically, the collimating unit 160 may be a collimating lens, the collimating lens may collimate the outgoing laser beam in any direction perpendicular to the outgoing laser beam, and further, the collimating lens may collimate the outgoing laser beam in the first direction X and the second direction Y into parallel light. Alternatively, the collimating unit 160 may be a cylindrical lens, the cylindrical lens may collimate the emitted laser beam into parallel light only in the first direction X, the axial meridian 1601 of the cylindrical lens extends along the second direction Y, the second direction Y is parallel to the first plane, the extending direction of the refractive power meridian 1602 is perpendicular to the second direction Y, and the placing position of the collimating unit 160 may be defined such that the cylindrical lens collimates the laser beam emitted by the laser light source 150 in the first direction X, and the laser light source 150 is located at the focal plane of the cylindrical lens. The second integrated beam shaping unit 190 includes a third surface 1901 and a fourth surface 1902, which are away from each other, the fourth surface 1902 is located on a side of the third surface 1901 away from the laser source 150, the laser beam emitted from the laser source 150 enters the collimating unit 160, and then is emitted from the collimating unit 160 to the third surface 1901 of the second integrated beam shaping unit 190, the third surface 1901 can primarily diffuse and emit the laser beam in the second direction Y, the laser beam that has undergone the primary diffusion exits through the fourth surface 1902 of the second integrated beam shaping unit 190, and the fourth surface 1902 can secondarily diffuse and emit the laser beam in the second direction Y. The laser beam emitted from the laser light source 150 can be first-order diffused and second-order diffused by the second integrated beam shaping unit 190, and the emission of the line laser beam with a larger field angle can be obtained under the condition that the number of optical elements in the laser projector 131 is the same.

In one embodiment, as shown in fig. 17, a collimating lens is used as the collimating unit 160, the third surface 1901 of the second integrated beam-shaping unit 190 is a wavy surface, and the fourth surface 1902 of the second integrated beam-shaping unit 190 is a concave cylindrical surface. The collimating lens can collimate the outgoing laser beam in any direction perpendicular to the outgoing laser beam, the collimated parallel light enters the third surface 1901 of the second integrated beam shaping unit 190, the beam width of the laser beam is not changed by the third surface 1901 in the first direction X, the laser beam can be primarily diffused by the third surface 1901 in the second direction Y and then emitted to the fourth surface 1902, the beam width of the laser beam is not changed by the fourth surface 1902 in the first direction X, the laser beam can be secondarily diffused by the fourth surface 1902 in the second direction Y and then emitted, and the linear laser beam with a larger field angle can be finally emitted through twice diffusion of the third surface 1901 and the fourth surface 1902 of the second integrated beam shaping unit 190. It should be noted that, the wave surface utilizes the refraction principle of light to uniformly expand the parallel light beams incident to the wave surface, so that the light loss generated by the light is less, and the light spot brightness of the output linear laser beam is higher. The concave cylindrical surface utilizes the divergence principle of the concave mirror to carry out dodging and beam expanding treatment on the laser beam incident to the concave cylindrical surface, so that the divergence angle of the laser beam is increased.

In another embodiment, fig. 18 is a schematic optical path diagram of a dtof module laser projector according to an embodiment of the present invention, as shown in fig. 18, a collimating lens is used as the collimating unit 160, a third surface 1901 of the second integrated beam shaping unit 190 is a roof-ridge surface, and a fourth surface 1902 of the second integrated beam shaping unit 190 is a concave cylindrical surface. The collimating lens can collimate the outgoing laser beam in any direction perpendicular to the outgoing laser beam, the collimated parallel light enters the third surface 1901 of the second integrated beam shaping unit 190, the beam width of the laser beam is not changed by the third surface 1901 in the first direction X, the laser beam can be primarily diffused by the third surface 1901 in the second direction Y and then emitted to the fourth surface 1902, the beam width of the laser beam is not changed by the fourth surface 1902 in the first direction X, the laser beam can be secondarily diffused by the fourth surface 1902 in the second direction Y and then emitted, and the linear laser beam with a larger field angle can be finally emitted through twice diffusion of the third surface 1901 and the fourth surface 1902 of the second integrated beam shaping unit 190. It should be noted that the curved arc top of the ridge surface is a complex aspheric curve, which can generate a large amount of spherical aberration, thereby redistributing light along the linear direction, reducing light rays in the central area, increasing light ray intensity at the end of the linear direction, and improving uniformity of linear laser. The concave cylindrical surface utilizes the divergence principle of the concave mirror to carry out dodging and beam expanding treatment on the laser beam incident to the concave cylindrical surface, so that the divergence angle of the laser beam is increased.

In another embodiment, fig. 19 is a schematic optical path diagram of a dtof module laser projector according to another embodiment of the present invention, as shown in fig. 19, a cylindrical lens is used as the collimating unit 160, a third surface 1901 of the second integrated beam shaping unit 190 is a diffusing microstructure surface, and a fourth surface 1902 of the second integrated beam shaping unit 190 is a concave cylindrical surface. The cylindrical lens can collimate the outgoing laser beam in the first direction X, the collimated parallel light enters the third surface 1901 of the second integrated beam shaping unit 190, the beam width of the laser beam is not changed by the third surface 1901 in the first direction X, the laser beam can be primarily diffused by the third surface 1901 in the second direction Y and then exits to the fourth surface 1902, the beam width of the laser beam is not changed by the fourth surface 1902 in the first direction X, the laser beam can be secondarily diffused by the fourth surface 1902 in the second direction Y and exits, and the outgoing linear laser beam with a larger field angle is finally obtained by twice diffusion of the third surface 1901 and the fourth surface 1902 of the second integrated beam shaping unit 190. It should be noted that, a diffusion microstructure surface is used as the third surface 1901 of the second integrated beam shaping unit 190, the requirement of the diffusion microstructure surface on the incident laser beam is low, and only the emergent laser beam needs to be collimated in the first direction X to be parallel light, so the collimating unit 160 may adopt a cylindrical lens, the cylindrical lens may collimate the laser beam emitted from the laser light source 150 in the first direction X, the collimating unit 160 may also adopt a collimating lens, and the collimating lens may collimate the emergent laser beam in any direction perpendicular to the laser beam emitted from the laser light source 150.

The laser projector 131 shown in fig. 17-19 includes a laser light source 150, a collimating unit 160, and a second integrated beam shaping unit 190, wherein a third surface 1901 and a fourth surface 1902 of the second integrated beam shaping unit 190 have different structures, and the second integrated beam shaping unit 190 can diffuse the emitted laser beam twice, so as to increase the divergence angle of the linear laser beam, and improve the integration level of the panoramic solid-state lidar without changing the number of used optical elements.

Fig. 20 is a schematic optical path diagram of a dtof module laser projector according to an embodiment of the present invention, as shown in fig. 20, optionally, the collimating unit 160 is a collimating lens, the laser projector 131 further includes a telescope unit 200, the telescope unit 200 is disposed on the optical path of the outgoing beam of the laser light source 150 and behind the collimating lens; the telescope unit 200 is used to expand the outgoing laser beam in the second direction Y.

Specifically, the laser projector 131 further includes a telescope unit 200, the telescope unit 200 is disposed on the optical path of the outgoing beam of the laser light source 150, the telescope unit 200 can make the incoming parallel beam still outgoing in parallel, and the telescope unit 200 can expand the outgoing laser beam in the second direction Y, increasing the divergence angle of the laser beam in the second direction Y. Illustratively, the laser projector 131 includes a laser light source 150, a collimating unit 160, a diffusing unit 170, and a telescope unit 200, and the telescope unit 200 may be located between the laser light source 150 and the collimating unit 160, or between the collimating unit 160 and the diffusing unit 170, and fig. 18 is merely an example, and is not limited thereto. It should be noted that the incident laser beam of the telescope unit 200 should be a laser beam incident in parallel in any direction, and therefore, a collimating lens is used as the collimating unit 160, and a wave mirror 1702 or a powell lens 1703 is used as the diffusing unit 170.

Alternatively, with continued reference to fig. 20, the telescope unit 200 includes a concave cylindrical lens 2001 and a convex cylindrical lens 2002, the concave cylindrical lens 2001 and the convex cylindrical lens 2002 being sequentially arranged on the optical path of the outgoing laser beam after the collimator lens; the axial meridians of the concave cylindrical lens 2001 and the convex cylindrical lens 2002 both extend in the first direction X, and the extending direction of the refractive power meridian is perpendicular to the first direction X; the object focal line of the concave cylindrical lens 2001 coincides with the object focal line of the convex cylindrical lens 2002.

Specifically, the laser beam emitted from the laser light source 150 sequentially enters the collimating unit 160, the telescope unit 200, and the diffusing unit 170, and finally the linear laser beam with a larger field angle is emitted. In which a collimating lens is used as the collimating unit 160 and a waved mirror 1702 is used as the diffusing unit 170. Illustratively, the telescope unit 200 may employ a galilean telescope structure, that is, it is composed of a concave cylindrical lens 2001 and a convex cylindrical lens 2002, the concave cylindrical lens 2001 and the convex cylindrical lens 2002 are sequentially arranged on the optical path of the outgoing laser beam after the collimator lens, axial meridians of the concave cylindrical lens 2001 and the convex cylindrical lens 2002 both extend in a first direction X, the extending direction of the refractive power meridian is perpendicular to the first direction X, and the direction in which the curvature of the curved surface of the concave cylindrical lens 2001 and the convex cylindrical lens 2002 continuously changes is parallel to the first direction X. The laser beam emitted from the laser source 150 is collimated into a parallel beam by the collimating unit 160, the parallel beam enters the telescope unit 200, the beam width of the laser beam is not changed in the first direction X, and the laser beam is subjected to beam-homogenizing and beam-expanding treatment in the second direction Y, so that the beam aperture of the laser beam emitted from the telescope unit 200 in the second direction Y is increased. Further, if a wave mirror 1702 of a larger aperture is employed as the diffusing unit 170, a line laser beam of a larger angle of view can be obtained as compared with the above-described embodiment.

The laser projector 131 shown in fig. 20 includes a laser light source 150, a collimating unit 160, a diffusing unit 170, and a telescope unit 200. The telescope unit 200 is located between the collimating unit 160 and the diffusing unit 170, and can perform uniform beam expanding processing on the laser beam emitted by the collimating unit 160, compared with the case that the emitted laser beam of the telescope unit 200 is not added, the beam aperture of the laser beam emitted by the telescope unit 200 to the diffusing unit 170 in the second direction Y is increased, and the divergence angle of the linear laser beam is effectively increased.

With continued reference to fig. 4-20, optionally, the laser projector 131 includes a laser light source 150, the laser light source 150 including any one of a vertical cavity surface emitting laser, an edge emitting laser, a horizontal cavity surface emitting laser.

Specifically, the edge-emitting laser is a horizontal resonant cavity, and has the advantages of long cavity length, large gain, small light-emitting aperture, high power density and the like, but the packaging process is complex. The vertical cavity surface emitting laser is a vertical resonant cavity, can realize wafer level manufacturing and testing, has the advantages of low volume production cost, simple patch form and the like, but has short cavity, small gain and small light emitting power. The horizontal cavity surface emitting laser is a horizontal resonant cavity, and can emit laser beams in the vertical direction by connecting a reflector or a diffractive optical element in the horizontal resonant cavity, the horizontal cavity surface emitting laser has the advantages of an edge emitting laser and a vertical cavity surface emitting laser at the same time, a high-order grating, such as a binary grating, a linear grating, a non-uniform grating and the like, can be arranged in the horizontal cavity surface emitting laser, and the output laser beams are uniform strip-shaped light spots after the laser beams are coupled by the high-order grating. The long side direction of the stripe-shaped light spot is parallel to the second direction Y (Y direction shown in fig. 4), and the short side direction of the stripe-shaped light spot is parallel to the first direction X (X direction shown in fig. 4).

Fig. 21 is a schematic structural diagram of a dtof module laser source according to an embodiment of the invention, and as shown in fig. 21, optionally, the laser source 150 is a vertical cavity surface emitting laser; the laser projector 131 includes a line laser light source 150, and the line laser light source 150 includes a plurality of laser light emitting points arranged in sequence along the second direction Y; wherein the second direction Y is parallel to the first plane.

Specifically, when the laser light source 150 is a vertical cavity surface emitting laser, the laser projector 131 includes a line laser light source 150, and the line laser light source 150 is composed of a plurality of laser light emitting points arranged in sequence in the second direction Y. The laser beam emitted by the linear array laser light source 150 has a certain divergence angle, the laser emitted by different laser light emitting points are overlapped on an incident plane to form a strip-shaped light spot, the long side direction of the strip-shaped light spot is parallel to the second direction Y, and the short side direction of the strip-shaped light spot is parallel to the first direction X.

FIG. 22 is a schematic structural diagram of another dtof module laser source according to an embodiment of the invention, where as shown in FIG. 22, optionally the laser source 150 is a horizontal-cavity surface-emitting laser; the laser projector 131 includes a plurality of horizontal cavity surface emitting lasers, which are sequentially arranged in the second direction Y; wherein the second direction Y is parallel to the first plane.

Specifically, as shown in fig. 22, when the laser light source 150 is a horizontal cavity surface emitting laser, the laser projector 131 includes one horizontal cavity surface emitting laser. Fig. 23 is a schematic diagram of an optical path corresponding to the laser light source in the dtof module shown in fig. 22, as shown in fig. 23, a horizontal cavity surface emitting laser is used as the laser light source 150, the laser beam emitted by the laser light source 150 has a small included angle between the

light rays

2 and 3 or the

light rays

1 and 4, that is, the laser beam output by the horizontal cavity surface emitting laser in the short side direction is a collimated laser beam, the divergence angle of the laser beam in the short side direction is generally less than 0.5 °, the laser beam emitted in the long side direction is not collimated, the divergence angle of the laser beam in the long side direction is large, and exemplarily, the included angle between the

light rays

1 and 2 or the

light rays

3 and 4 is generally 10 ° to 30 °.

Further, fig. 24 is a schematic structural diagram of another dtof module laser light source provided in the embodiment of the present invention, as shown in fig. 24, when the laser light source 150 is a horizontal cavity surface emitting laser, the laser projector 131 includes three horizontal cavity surface emitting lasers, the three horizontal cavity surface emitting lasers are sequentially arranged along the second direction Y, and an interval between adjacent horizontal cavity surface emitting lasers is generally 100-500 μm, exemplarily, the energy of one horizontal cavity surface emitting laser cannot meet the requirement of remote measurement, a plurality of horizontal cavity surface emitting lasers may be simultaneously used, and the energies of a plurality of horizontal cavity surface emitting lasers are superimposed in the laser projector 131, so that the requirement of remote measurement can be met, wherein the number of horizontal cavity surface emitting lasers depends on the requirement of distance measurement, which is only by way of example and is not limited. Fig. 25 is a schematic optical path diagram corresponding to a dtof module laser projector according to an embodiment of the invention, and as shown in fig. 25, when the laser source 150 is a horizontal cavity surface emitting laser, a laser beam emitted from the laser source 150 enters the diffusing unit 170 along the optical path. Illustratively, laser beams emitted by three horizontal cavity surface emitting lasers are superposed and superposed with each other, after the laser beams pass through the collimating unit 160 and the diffusing unit 170, a linear laser beam with three times of the laser energy of a single horizontal cavity surface emitting laser can be obtained, the beam width of the finally obtained linear laser beam is consistent with the beam width of the linear laser beam of the single horizontal cavity surface emitting laser, the energy of the laser beam is increased on the basis of not changing the beam width of the linear laser beam, and the measurable distance of the panoramic solid-state laser radar is increased. In addition, the horizontal cavity surface emitting laser does not need to additionally add the collimating unit 160 to collimate the laser beam, the horizontal cavity surface emitting laser can directly enter the diffusing unit 170, the collimating unit 160 is not needed, the number of optical elements used is reduced, the structure of the laser projector 131 is simpler, the complexity and the production and assembly cost of the laser projector 131 are effectively reduced, and the linear laser beam with a larger field angle is finally obtained. In addition, when the laser light source 150 is an edge emitting laser, the laser beam emitted from the laser light source 150 is an elliptical laser beam, the fast axis of the edge emitting laser corresponds to the long axis of the elliptical laser beam, the long axis of the elliptical laser beam is parallel to the second direction Y, the slow axis of the edge emitting laser corresponds to the short axis of the elliptical laser beam, and the short axis of the elliptical laser beam is parallel to the first direction X.

Fig. 26 is a schematic optical path diagram of a dtof module laser receiver provided in an embodiment of the invention, and as shown in fig. 26, optionally, the laser receiver 132 includes an imaging chip 210, a filtering unit 220 and an imaging lens unit 230, where the filtering unit 220 and the imaging lens unit 230 are respectively disposed on a receiving optical path of the imaging chip 210; the filter unit 220 is used for filtering at least part of the light rays with wavelengths not emitted by the laser projector 131, and the imaging lens unit 230 is used for imaging reflected light formed by the externally reflected light rays emitted by the laser projector 131 on the imaging chip 210; the relative illuminance spatial distribution of the imaging lens unit 230 is opposite in tendency to the light intensity spatial distribution of the laser projector 131.

Specifically, the laser receiver 132 includes an imaging chip 210, a filter unit 220, and an imaging lens unit 230, and the filter unit 220 and the imaging lens unit 230 are respectively disposed on a receiving optical path of the imaging chip 210. The central wavelength of the filter unit 220 is the same as the wavelength of the laser beam emitted by the laser projector 131, and the filter unit 220 can filter at least part of the light rays with wavelengths other than the light rays emitted by the laser projector 131, that is, the filter unit 220 can filter the laser beams with different wavelengths, thereby improving the signal-to-noise ratio of the image formed by the imaging chip 210. The imaging lens unit 230 may be composed of one or more lenses, for example, a material of the lens may be resin or glass, and the imaging lens unit 230 may image reflected light formed by light emitted from the laser projector 131 reflected from the outside on the imaging chip 210. The imaging chip 210 generally comprises SPAD pixel array, TDC circuit, histogram circuit, etc., and the imaging chip 210 may be a linear array chip in order to cooperate with the linear laser beam emitted from the laser projector 131. When the TDC starts timing, a trigger signal is synchronously sent out to drive the laser projector 131 to emit a linear laser beam with a certain frequency, the linear laser beam is projected to the surface of an object and reflected to the laser receiver 132 by the object, when the SPAD pixels in the laser receiver 132 sense the reflected light, an avalanche pulse signal is generated and output to the TDC, so that the TDC stops counting, the TDC calculates the time interval from the time when photons send out light pulses from the laser projector 131 to the time when the laser receiver 132 receives the avalanche voltage signal, converts the time interval into a digital code, and transmits the digital code to the subsequent control processing module 20 to obtain the depth distance information of the object.

It should be noted that, during the design process, the imaging lens unit 230 of the laser receiver 132 may adjust the spatial distribution of the relative illuminance of the imaging lens unit 230 with reference to the light intensity distribution of the line laser beam emitted from the laser projector 131, or the light intensity distribution of the line laser beam emitted from the laser projector 131 may adjust the emitted line laser beam with reference to the spatial distribution of the relative illuminance of the imaging lens unit 230, so as to ensure that the luminance distribution of the line laser beam incident on the imaging lens unit 230 of the laser receiver 132 in different fields of view is uniform. Fig. 27 is a schematic diagram of a luminance distribution curve of a line laser beam emitted by a dtof module laser projector according to an embodiment of the present invention, and fig. 28 is a schematic diagram of a relative illuminance distribution curve of an imaging unit of a laser receiver according to a dtof module according to an embodiment of the present invention, as shown in fig. 27 and fig. 28, if the luminance distribution curve of the line laser beam emitted by the laser projector 131 is bright at four sides and dark at the middle, the corresponding imaging unit 230 can adjust the Relative Illuminance (RI) curve of the imaging unit 230 to be bright at the middle and dark at the four sides in the design process. In addition, the brightness distribution of the linear laser beam emitted by the laser projector 131 can be correspondingly adjusted according to the distribution of the Relative Illuminance (RI) curve of the imaging unit 230, so as to finally ensure that the linear laser beam emitted by the laser projector 131 is imaged on the imaging chip 210 as a linear laser beam with uniform brightness, which is beneficial to measuring the depth distance information of the image.

Based on the same inventive concept, the embodiment of the invention also provides a mobile robot navigation system. The mobile robot navigation system comprises the panoramic solid-state laser radar provided by any embodiment of the invention. Therefore, the mobile robot navigation system provided by the embodiment of the invention has the corresponding beneficial effects of the panoramic solid-state lidar provided by the embodiment of the invention, and the details are not repeated here.

It is to be noted that the foregoing description is only exemplary of the invention and that the principles of the technology may be employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious modifications, rearrangements, combinations and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A panoramic solid-state laser radar is characterized by comprising a plurality of dtof modules;

2. The panoramic solid state lidar of claim 1, wherein the laser projector comprises a laser light source, a collimating unit, and a diffusing unit, the collimating unit and the diffusing unit being disposed on an optical path of an outgoing laser beam of the laser light source, respectively;

3. The panoramic solid state lidar of claim 2, wherein the collimating unit comprises a cylindrical lens having an axial meridian extending in the second direction, and a power meridian extending perpendicular to the second direction; the laser light source is positioned on the focal plane of the cylindrical lens; the diffusion unit comprises a shaping diffusion sheet;

4. The panoramic solid state lidar of claim 2, wherein the laser source comprises a laser chip, and the diffuser is attached to a light emitting surface of the laser chip.

5. The panoramic solid state lidar of claim 1, wherein the laser projector comprises a laser light source and a first integrated beam shaping unit disposed on an optical path of an emitted laser beam of the laser light source;

6. The panoramic solid state lidar of claim 5, wherein the first integrated beam shaping unit comprises a first surface and a second surface facing away from each other, the second surface being located on a side of the first surface remote from the laser light source;

7. The panoramic solid state lidar of claim 1, wherein the laser projector comprises a laser light source, a collimating unit, and a second integrated beam shaping unit, the collimating unit and the second integrated beam shaping unit being disposed on an optical path of an outgoing laser beam of the laser light source, respectively;

the collimation unit is used for collimating the emergent laser beam at least in a first direction, and the second integrated beam shaping unit is used for diffusing the emergent laser beam twice in a second direction;

8. The panoramic solid state lidar of claim 7, wherein the second integrated beam shaping unit comprises a third surface and a fourth surface facing away from each other, the fourth surface being located on a side of the third surface remote from the laser light source;

the collimating unit comprises a collimating lens, and the collimating lens collimates the emergent laser beam in any direction vertical to the emergent laser beam; the third surface is a wavy surface or a ridge surface, and the fourth surface is an inner concave cylindrical surface; or, the collimating unit includes a cylindrical lens, an axial meridian of the cylindrical lens extending in the second direction, an extending direction of a power meridian being perpendicular to the second direction; the laser light source is positioned on the focal plane of the cylindrical lens; the third surface is a diffusion microstructure surface, and the fourth surface is an inner concave cylindrical surface.

9. The panoramic solid state lidar of claim 3 or 8, wherein the collimating unit is the collimating lens;

the telescope unit is used for expanding the emergent laser beam in the second direction.

10. The panoramic solid state lidar of claim 1, wherein the laser projector comprises a laser light source comprising any one of a vertical cavity surface emitting laser, an edge emitting laser, a horizontal cavity surface emitting laser.

11. The panoramic solid state lidar of claim 11, wherein the laser light source is a vertical-cavity surface-emitting laser;

the laser projector comprises a linear array laser light source, and the linear array laser light source comprises a plurality of laser light emitting points which are sequentially arranged along a second direction;

wherein the second direction is parallel to the first plane.

12. The panoramic solid state lidar of claim 11, wherein the laser light source is a horizontal cavity surface emitting laser;

13. The panoramic solid-state lidar of claim 1, wherein the laser receiver comprises an imaging chip, a filter unit, and an imaging lens unit, the filter unit and the imaging lens unit being disposed on a receiving optical path of the imaging chip, respectively;

14. A mobile robotic navigation system comprising a panoramic solid state lidar according to any of claims 1-13.