CN216748071U - A linear lidar - Google Patents

Abstract

An embodiment of the present utility model provides a linear laser radar, which includes a laser emission module and a laser receiving module corresponding to the laser emission module; the laser emission module includes a laser light source and a shaping lens, and the laser light source is used for The laser beam is emitted, and the shaping lens is used to shape the laser beam into a linear beam and output it to the target object; the laser receiving module includes a gated light channel and a detector array, and the detector array includes a linear beam along the line. A plurality of laser detectors are arranged, and the gated light channel is used to selectively irradiate the reflected beam of the target object to the plurality of laser detectors in the detector array. In the technical solution of the present utility model, the laser emitting module converts the point light source into a line light source through a shaping lens to realize linear emission, and the laser receiving module makes the received signal gated and projected onto the laser detector by gating the optical channel, so as to realize Detection with high angular resolution.

Description

A linear lidar

technical field

The utility model relates to the technical field of radar, in particular to a linear laser radar.

Background technique

Lidar is a radar system that detects the distance, azimuth and other characteristic quantities of target objects by emitting laser beams. Because it can obtain the three-dimensional information of the target object, it has the advantages of strong anti-interference ability and high resolution, so it occupies an important position in the field of automatic driving and robotics.

Existing lidars have two ways to achieve large field of view and multi-line detection. One is to use light sources, which usually requires multiple light sources to be arranged, which is not only limited by the size of the light source, but also increases the cost; the other is to use the detection method. The angular resolution of the device is limited by the characteristics of the detection device itself, and high resolution cannot be achieved.

Utility model content

The embodiment of the present utility model provides a linear laser radar, which aims to realize the detection of a large field of view and high resolution of the laser radar by using a simple device.

The utility model provides a linear laser radar, comprising a laser emitting module and a laser receiving module corresponding to the laser emitting module;

The laser emission module includes a laser light source and a shaping lens, the laser light source is used for emitting a laser beam, and the shaping lens is used for shaping the laser beam into a linear beam and outputting it to the target object;

The laser receiving module includes a gated light channel and a detector array, the detector array includes a plurality of laser detectors arranged along the linear beam, and the gated light channel is used to select the reflected light beam of the target object irradiates randomly onto a plurality of laser detectors in the detector array.

In a specific embodiment, the shaping lens is a Powell lens or a one-line mirror.

In a specific embodiment, the laser emitting module further includes a collimating lens, the collimating lens is located between the laser light source and the shaping lens, and the collimating lens is used for collimating the laser beam.

In a specific embodiment, the collimating lens is a lens for collimating the laser beam into a beam with a divergence angle of less than 10 mrad.

In a specific embodiment, the laser light source is a laser diode.

In a specific embodiment, the gated optical channel includes a liquid crystal switch array, the liquid crystal switch array includes a plurality of independently controllable liquid crystal switches, and the plurality of the liquid crystal switches are arranged corresponding to the plurality of the laser detectors, When any one of the liquid crystal switches is turned on, the reflected light beam of the target object can pass through the opening of any one of the liquid crystal switches, and irradiate the laser detector corresponding to any one of the liquid crystal switches.

In a specific embodiment, the gated light channel includes a diaphragm and a driving unit, the light-transmitting hole of the diaphragm is opposite to the detector array in the direction of the optical axis of the laser detector, and the driving unit The unit is coupled and connected to the diaphragm for driving the diaphragm to move along the linear beam.

In a specific embodiment, the laser receiving module further includes a receiving mirror group, the receiving mirror group is located on the side of the gated light channel away from the detector array, and the receiving mirror group is used to detect the target object. The reflected beams are converged.

In a specific embodiment, the laser detector is an avalanche photodiode.

In a specific embodiment, the linear laser radar further includes a radar housing, and both the laser transmitting module and the laser receiving module are arranged in the radar housing.

In the technical solution of the present utility model, the laser emitting module converts the point light source into a line light source through a shaping lens to realize linear emission, and the laser receiving module makes the received signal gated and projected onto the laser detector by gating the optical channel, so as to realize Detection of high angular resolution, so the linear lidar uses simple devices to achieve high-resolution detection in a large field of view.

Description of drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are just some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

1 is a schematic structural diagram of a linear laser radar according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of the detector array in FIG. 1;

Description of reference numerals: linear laser radar 100, laser emission module 1, laser light source 11, shaping lens 12, collimating lens 13, laser receiving module 2, gated optical channel 21, liquid crystal switch array 211, liquid crystal switch 212, detection The device array 22 , the laser detector 221 , the receiving circuit board 222 , and the receiving mirror group 23 .

Detailed ways

The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, but not all of them. Example. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

It should be noted that if there are directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention, the directional indications are only used to explain a certain posture (such as the accompanying drawings). When the relative positional relationship, movement situation, etc. between the various components shown below), if the specific posture changes, the directional indication also changes accordingly.

In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for the purpose of description, and should not be construed as instructions or Implicit their relative importance or implicitly indicate the number of technical features indicated. Thus, a feature delimited with "first", "second" may expressly or implicitly include at least one of that feature. In addition, the meaning of "and/or" in the whole text includes three parallel schemes. Taking "A and/or B" as an example, it includes scheme A, scheme B, or scheme satisfying both of A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but must be based on the realization by those of ordinary skill in the art. When the combination of technical solutions is contradictory or cannot be realized, it should be considered that the combination of technical solutions does not exist. , is not within the scope of protection required by the present utility model.

Existing lidars have two ways to achieve large field of view and multi-line detection. One is to use light sources, which usually requires multiple light sources to be arranged, which is not only limited by the size of the light source, but also increases the cost; the other is to use the detection method. The angular resolution of the device is limited by the characteristics of the detection device itself, and high resolution cannot be achieved.

In view of this, the present invention provides a linear laser radar, and FIG. 1 and FIG. 2 are an embodiment of the linear laser radar provided by the present invention.

Referring to FIG. 1 and FIG. 2 , in this embodiment, the linear laser radar 100 includes a laser emitting module 1 and a laser receiving module 2 corresponding to the laser emitting module 1 ; the laser emitting module 1 includes a laser light source 11 and a shaper The lens 12, the laser light source 11 is used to emit the laser beam, and the shaping lens 12 is used to shape the laser beam into a linear beam and output to the target object; the laser receiving module 2 includes a gated light channel 21 and a detector array 22, the detector array 22 includes a plurality of laser detectors 221 arranged along the linear beam, and the gated light channel 21 is used for selectively irradiating the reflected beam of the target object to the plurality of laser detectors 221 in the detector array 22 .

Specifically, the linear lidar 100 can send a laser detection signal through the laser emission module 1. After the laser detection signal encounters the target object, it is diffusely reflected and returned to the laser receiving module 2. The linear lidar 100 can transmit and receive The time interval of the signal is multiplied by the speed of light, and then divided by 2 to calculate the distance between the linear lidar 100 and the target object. The laser transmitting module 1 and the laser receiving module 2 are set correspondingly, which means that the laser detection signal sent by the laser transmitting module 1 can be received by the laser receiving module 2 after being reflected by the target object.

The laser emitting module 1 emits a laser beam to the target object through a laser light source 11, which is a point light source, and the outgoing laser beam from the laser light source 11 needs to be shaped by a shaping lens 12 before it emits a linear laser radar 100 to the target object. The outgoing laser beam from the laser light source 11 passes through the shaping lens 12, and can be shaped into a “one” beam with uniform energy, that is, a linear beam. Large FOV of LiDAR 100.

The plurality of laser detectors 221 in the detector array 22 form the photosensitive surface of the detector array 22, and the plurality of laser detectors 221 in the detector array 22 are arranged along the linear beam, that is, along the linear beam. Arranged along the extension direction of the line beam, and the extension direction of the line beam is the extension direction of the projection of the line beam on the reference plane, wherein the reference plane is a plane perpendicular to the optical axis of the laser light source 11 . The linear beam of the laser emitting module 1 is directed to the target object, and is reflected by the target object to form a linear reflected beam. The linear reflected beam can return along the original path. The gating optical channel 21 can make the linear reflected beam selective. The ground part passes through to form a light spot (ie, receives a signal), and the light spot is projected onto the photosensitive surface of the detector array 22 to hit the corresponding laser detector 221 . In the process of selectively projecting the linear reflected light beams at different positions of the photosensitive surface of the detector array 22 , detection with high angular resolution of the linear laser radar 100 can be realized. For example, the gated light channel 21 can make the light spot project on the plurality of laser detectors 221 in a rolling shutter manner, that is, the gated light channel 21 can make the light spot project to the plurality of laser detectors 221 in turn along the arrangement direction of the plurality of laser detectors 221 . On the laser detector 221 , the following description will be given by taking as an example that the gating optical channel 21 can allow the linear reflected light beams to be sequentially projected to different positions of the photosensitive surface of the detector array 22 in a rolling shutter manner.

In the technical solution of the present invention, the laser emitting module 1 converts the point light source into a line light source through the shaping lens 12 to realize linear emission, and the laser receiving module 2 makes the received signal be gated and projected to the laser detection by gating the optical channel 21 On the device 221, detection with high angular resolution is realized. In this way, the linear lidar 100 realizes detection with a large field of view and high resolution by using simple devices.

Optionally, in this embodiment, the linear lidar 100 further includes a control module (not shown in the figure), and the control module is electrically connected to the laser transmitter module 1 and the laser receiver module 2 for controlling the laser transmitter module 1 and the laser receiver module 2. Laser receiver module 2.

Specifically, the control module is electrically connected to the laser light source 11 for controlling the laser light source 11 to emit a laser beam, the control module is electrically connected to the detector array 22 for controlling the detector array 22 to receive the reflected beam, and the control module can transmit and receive the reflected beam according to the signal to calculate the distance between the linear lidar 100 and the target object. At the same time, the control module is electrically connected to the gated light channel 21 for controlling the gated light channel 21 so that the linear reflected light beams can be projected to different positions of the photosensitive surface of the detector array 22 in a rolling shutter manner. The control module realizes high-speed rolling shutter gating by controlling the detector array 22, so as to achieve the purpose of high-frequency scanning detection. Wherein, the control module is usually a Field Programmable Gate Array (Field Programmable Gate Array, FPGA).

The laser light source 11 is used for emitting a laser beam, and the laser light source 11 can be a laser diode LD or a vertical cavity surface emitting laser VCSEL, etc. The laser light source 11 can be a free space output or output through a fiber coupling; the laser light source 11 can also be a fiber laser, a gas Lasers or solid-state lasers, etc. The laser wavelength of the laser beam of the laser light source 11 may be 905 nm or 1550 nm. The light-emitting end of the laser light source 11 faces the light-incident surface of the shaping lens 12 . Optionally, in this embodiment, the laser light source is a laser diode light source with a wavelength of 11905nm or 1550um.

Optionally, referring to FIG. 1 , in this embodiment, the laser emitting module 1 further includes a collimating lens 13 , the collimating lens 13 is located between the laser light source 11 and the shaping lens 12 , and the collimating lens 13 is used for aligning the laser beam collimated. The collimating lens 13 can collimate the laser light source 11 , so that the laser beam of the laser light source 11 is collimated by the collimating lens 13 , and then directed to the light incident surface of the shaping lens 12 . The collimating lens 13 and the laser light source 11 are usually arranged coaxially, and there may be one collimating lens 13 , or a plurality of collimating lenses 13 may be arranged along the optical axis direction of the laser light source 11 according to the actual situation.

Specifically, referring to FIG. 1 , in this embodiment, the collimating lens 13 is a lens for collimating the laser beam into a beam with a divergence angle less than 10 mrad, and the collimating lens 13 can collimate the laser beam of the laser light source 11 It is a beam with a divergence angle less than 10mrad. For example, the collimating lens 13 may be a plano-convex lens with a focal length of 12 mm and a diameter of 6 mm.

The shaping lens 12 can shape the laser beam of the laser light source 11 into a linear beam. Optionally, please refer to FIG. 1 . In this embodiment, the shaping lens 12 may be a diffractive optical element DOE, a Powell lens, or a one-word mirror.

The line-type lidar 100 may include one or more laser emitting modules 1, and when the line-type lidar 100 includes multiple laser emitting modules 1, the multiple laser emitting modules 1 may be along the first direction and/or the second direction Arrange.

Specifically, the first direction is the extending direction of the linear beam, and the second direction is the direction perpendicular to the first direction and the optical axis of the laser light source 11 . The plurality of laser emission modules 1 may be arranged in a one-dimensional matrix along the first direction or the second direction, and the plurality of laser emission modules 1 may also be arranged in a two-dimensional matrix along the first direction and the second direction.

The laser receiving module 2 receives the reflected beam through the detector array 22. When the reflected beam is projected on the laser detector 221 in the detector array 22, the laser detector 221 can convert the optical signal into an electrical signal, and the response of the laser detector 221 The wavelength range is consistent with the laser light source 11, wherein the laser detector 221 can be an avalanche photodiode (Avalanche Photon Diode, APD), a single photon avalanche diode (Single Photon Avalanche Diode, SPAD), a silicon photomultiplier tube (multi-pixel photon counter, Silicon photomultiplier, SiPM) and so on.

Optionally, please refer to FIG. 1 and FIG. 2, in this embodiment, the detector array 22 further includes a receiving circuit board 222, a plurality of laser detectors 221 are arranged on the same board surface of the receiving circuit board 222, and a plurality of laser detectors The detectors 221 are all facing the gated light channel 21 .

Optionally, please refer to FIG. 1, in this embodiment, the laser receiving module 2 further includes a receiving mirror group 23, the receiving mirror group 23 is located on the side of the gated optical channel 21 away from the detector array 22, and the receiving mirror group 23 uses Focusing on the reflected beam of the target object. The receiving mirror group 23 can focus the reflected light beam of the target object into a line shape, and then shoot toward the gated light channel 21 . The receiving lens group 23 includes at least one optical lens. For example, please refer to FIG. 1 . The receiving lens group 23 is a four-piece structure, which can meet the receiving requirements of a large field of view and a small curvature of field, and focus the signal beam into a linear shape.

The gated light channel 21 can make the linear reflected beams project onto the multiple laser detectors 221 in turn in a rolling shutter mode. The gate size of the gated light channel 21 can be adjusted according to the actual situation, so as to limit the scanning resolution and select The gating range of the light-passing channel 21 may be less than or equal to the detection range of the detector array 22 . There are many ways to set the gated light channel 21. For example, please refer to FIG. 1 and FIG. 2. In this embodiment, the gated light channel 21 includes a liquid crystal switch array 211, and the liquid crystal switch array 211 includes a plurality of independently controllable The liquid crystal switch 212, a plurality of liquid crystal switches 212 are correspondingly arranged with a plurality of laser detectors 221, for when any one of the liquid crystal switches 212 is turned on, the reflected light beam of the target object can pass through from the opening of any one of the liquid crystal switches 212, and the light beam is irradiated. to the laser detector 221 corresponding to any one of the liquid crystal switches 212 .

Specifically, the plurality of liquid crystal switches 212 are correspondingly arranged with the plurality of laser detectors 221. If any one of the liquid crystal switches 212 is turned on, the reflected light beam can pass through the gated light channel 21 from the any one of the liquid crystal switches 212, and be projected onto the corresponding light beam. On the laser detector 221 corresponding to any one of the liquid crystal switches 212 ; if any one of the liquid crystal switches 212 is closed, the reflected light beam cannot be projected onto the laser detector 221 corresponding to any one of the liquid crystal switches 212 .

The plurality of liquid crystal switches 212 are arranged corresponding to the plurality of laser detectors 221 . One laser detector 221 may correspond to one liquid crystal switch 212 , or a plurality of adjacent laser detectors 221 may correspond to one liquid crystal switch 212 . The switch 212 corresponding to a laser detector 221 is described as an example. The number of the liquid crystal switches 212 is the same as the number of the laser detectors 221 , and the positions of the plurality of liquid crystal switches 212 correspond one-to-one with the positions of the plurality of laser detectors 221 respectively. The liquid crystal switch 212 acts as a switch or a diaphragm, that is, when the liquid crystal switch 212 is turned on, the light beam from the receiving mirror group 23 and incident on the turned on liquid crystal switch 212 is allowed to pass through and irradiate to a corresponding one of the laser detectors 221. . The liquid crystal switch 212 may be a normally closed switch, that is, the liquid crystal switch 212 is in a closed state in a normal state, and the light beam incident thereon is not allowed to pass through.

The plurality of liquid crystal switches 212 are all electrically connected to the control module, and the control module can independently control the opening or closing of each liquid crystal switch 212 . The control module may have a built-in preset sequence logic for sequentially controlling the opening and closing of the plurality of liquid crystal switches 212 in the liquid crystal switch array 211 according to the sequence, so as to achieve the purpose of high-frequency scanning detection. The size and switching frequency of the liquid crystal switch 212 can be set according to actual conditions to limit the scanning resolution.

In addition to the above-mentioned use of the liquid crystal switch array 211 as the gated light channel 21, there are other ways of setting the gated light channel 21. For another example, in other embodiments, the gated light channel 21 includes a diaphragm and a driver. unit, the light-transmitting hole of the diaphragm is opposite to the detector array 22 in the direction of the optical axis of the laser detector 221, and the driving unit is coupled and connected to the diaphragm for driving the diaphragm to move along the linear beam, and the driving unit can drive The diaphragm moves back and forth along the arrangement direction of the plurality of laser detectors 221. When the light-transmitting hole of the diaphragm moves to a position opposite to any one of the laser detectors 221, the linear reflected beam can pass through the light-transmitting hole. Through the diaphragm, it is projected onto any one of the laser detectors 221. During the reciprocating movement of the diaphragm, the linear reflected beams can be projected onto the plurality of laser detectors 221 in turn in a rolling shutter manner. The frequency with which the diaphragm moves back and forth can limit the scan resolution. Wherein, the driving unit may be a micro-electromechanical system (Micro-Electro-Mechanical System, MEMS), a driving member made of piezoelectric material, etc., which is beneficial to achieve the purpose of high-frequency scanning detection.

For another example, in other embodiments, the gated light channel 21 includes a turntable and the turntable faces the liquid crystal switch array 211, the motor is used to drive the turntable to rotate, and the turntable corresponds to the plurality of liquid crystal switches 212 in the liquid crystal switch array 211 and is provided with a plurality of pass-through switches throughout. holes, and the plurality of through holes are arranged at intervals and staggered in the rotation direction of the turntable. When any through hole of the turntable rotates to a position opposite to the corresponding laser detector 221, the linear reflected light beam can pass through the turntable from the any through hole and be projected onto the corresponding laser detector 221. The staggered spacing of the plurality of through holes in the rotation direction of the turntable ensures that only one through hole is opposite to the corresponding laser detector 221 at a time, so that during the rotation of the turntable, the linear reflected light beams can be projected in turn in a rolling shutter manner onto the plurality of laser detectors 221 .

Optionally, referring to FIG. 1 , in this embodiment, the linear lidar 100 further includes a radar housing (not shown in the figure), and both the laser transmitting module 1 and the laser receiving module 2 are arranged in the radar housing. The laser transmitting module 1, the laser receiving module 2 and the control module are arranged in the radar cover. The radar cover usually includes a filter cover. The laser transmitting module 1 and the laser receiving module 2 are set corresponding to the filter cover. After passing through the filter mask, the laser beam exits the linear laser radar 100 to detect the target object, and the reflected beam of the target object also passes through the filter mask and enters the linear laser radar 100 to be received by the laser receiving module 2 .

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. Under the conception of the present invention, the equivalent structure transformation made by using the contents of the description and drawings of the present invention, or directly / Indirect applications in other related technical fields are included in the scope of patent protection of the present utility model.

Claims (10)

1. A linear laser radar, characterized in that it comprises a laser emission module and a laser receiving module corresponding to the laser emission module; The laser emission module includes a laser light source and a shaping lens, the laser light source is used for emitting a laser beam, and the shaping lens is used for shaping the laser beam into a linear beam and outputting it to the target object; The laser receiving module includes a gated light channel and a detector array, the detector array includes a plurality of laser detectors arranged along the linear beam, and the gated light channel is used to select the reflected light beam of the target object irradiates randomly onto a plurality of laser detectors in the detector array. 2 . The linear laser radar according to claim 1 , wherein the shaping lens is a Powell lens or a one-line mirror. 3 . 3 . The linear laser radar according to claim 1 , wherein the laser emission module further comprises a collimating lens, the collimating lens is located between the laser light source and the shaping lens, and the collimating lens is located between the laser light source and the shaping lens. 4 . Straight lenses are used to collimate the laser beam. 4 . The linear laser radar according to claim 3 , wherein the collimating lens is a lens for collimating the laser beam into a beam with a divergence angle less than 10 mrad. 5 . 5 . The linear laser radar of claim 1 , wherein the laser light source is a laser diode. 6 . 6. The linear laser radar according to any one of claims 1-5, wherein the gated optical channel comprises a liquid crystal switch array, and the liquid crystal switch array comprises a plurality of independently controllable liquid crystal switches. Each of the liquid crystal switches is correspondingly arranged with a plurality of the laser detectors, and is used to enable the reflected light beam of the target object to pass through the opening of any one of the liquid crystal switches when any one of the liquid crystal switches is turned on, and irradiate the light beam to the target object. on the laser detector corresponding to any one of the liquid crystal switches. 7. The linear lidar according to any one of claims 1-5, wherein the gated light channel comprises a diaphragm and a driving unit, and the light-transmitting hole of the diaphragm is connected to the detector array. Opposite in the direction of the optical axis of the laser detector, the driving unit is coupled and connected to the diaphragm for driving the diaphragm to move along the linear beam. 8. The linear laser radar according to any one of claims 1-5, wherein the laser receiving module further comprises a receiving mirror group, and the receiving mirror group is located in the gated optical channel away from the detection On one side of the receiver array, the receiving mirror group is used for converging the reflected light beam of the target object. 9 . The linear laser radar according to claim 1 , wherein the laser detector is an avalanche photodiode. 10 . 10. The linear laser radar according to any one of claims 1-5, wherein the linear laser radar further comprises a radar cover, and the laser transmitting module and the laser receiving module are both arranged on the inside the radar cover.

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