Summary of the invention
Problems solved by the invention is to provide a kind of laser radar and its emission system, the emission system of laser radar is setMeter method, according to point of diffraction optical element described in the ratio setting between default detection range each on the vertical field of view directionLight ratio, so that the preferable allocation proportion of laser radar power is realized, to reduce cost, simplified structure, reduction installation difficulty, mentionHigh-energy distributes stability.
To solve the above problems, the present invention provides a kind of emission system of laser radar, comprising:
Light source, the light source include at least one laser, and the laser is for emitting the first detection light beam；Emit lightComponent is learned, the transmitting optical module is used to the first detection beam collimation be directional light；Diffraction optical element, it is described to spread outIt penetrates optical element and collimated is divided into N per a branch of first detection light beam on the vertical field of view direction of the laser radarBeam second detects light beam, and the light splitting ratio between each angle of diffraction of the diffraction optical element is arranged to, each diffractionThe ratio between each default detection range on the corresponding vertical field of view direction of angle.
Optionally, the diffraction optical element is grating.
Optionally, the diffraction optical element is Darman raster.
Optionally, the default detection range on the vertical field of view direction is arranged to:
When visual field deflection in vertical field of view is 0 degree, presetting detection range is D；
When visual field deflection in vertical field of view is greater than 0 degree, default detection range DH is arranged to:
Wherein, α is the visual field deflection in vertical field of view, and H is the visual field side in 0 degree of vertical field of view of the laser radarTo angle direction and the preset laser radar maximum probe height corresponding to vertical range between position；
When visual field deflection in vertical field of view is less than 0 degree, default detection range DL is arranged to:
Wherein, α is the visual field deflection in vertical field of view, and L is the transmitting of laser radar described in the direction along vertical field of view systemThe mounting height of system.
Optionally, the default detection range on the vertical field of view direction is arranged to:
When visual field deflection in vertical field of view is 0 degree, presetting farthest detecting location corresponding to detection range is d；
When visual field deflection in vertical field of view is the visual field direction angle alpha max in maximum perpendicular visual field, detection range is presetCorresponding farthest detecting location is dh, presets detection range DH ' are as follows:
Wherein, direction and the preset laser of the H for the visual field deflection in 0 degree of vertical field of view of the laser radarVertical range between position corresponding to the maximum probe height of radar；
When visual field deflection in vertical field of view is the visual field direction angle alpha min in minimum vertical visual field, detection range is presetCorresponding farthest detecting location is dl, and default detection range DL ' is arranged to:
Wherein, L is the mounting height of laser radar emission system described in the direction along vertical field of view；
The envelope of farthest detecting location corresponding to default detection range on the vertical field of view direction be by d,The parabola of dh and dl.
Optionally, the light source includes an at least column laser, and an at least column laser is along the laser radarThe arrangement of vertical field of view direction, the optical axis of each laser and the visual field direction in 0 degree of vertical field of view of the laser radarAngular direction is in different default angles, and visual field deflection of the laser in 0 degree of vertical field of view of the laser radarDirection is axisymmetricly distributed.
Optionally, the angle difference between the default angle of adjacent laser is fixed value.
Optionally, the angle difference is any fixed value more than or equal to 0.1 degree and less than or equal to 5 degree.
Optionally, the angle difference between the default angle of adjacent laser is changing value.
Optionally, the angle difference increases with the increase of the default angle.
Correspondingly, the present invention also provides a kind of laser radars, comprising: emission system, the emission system are of the inventionEmission system；Reception system, the reception system receive the reflected light of the second detection light beam in three-dimensional space.
In addition, the present invention also provides a kind of forming method of the emission system of laser radar, the transmitting of the laser radarSystem includes: light source, and the light source includes at least one laser, and the laser is for emitting the first detection light beam；TransmittingOptical module, the transmitting optical module are used to the first detection beam collimation be directional light；Diffraction optical element, it is describedDiffraction optical element is on the vertical field of view direction of the laser radar by collimated per a branch of first detection light beam pointLight beam is detected at N beam second；The design method includes: the light splitting ratio between each angle of diffraction of the diffraction optical elementThe ratio being set as between each default detection range on the corresponding vertical field of view direction of each angle of diffraction.
Optionally, the default detection range setting on the vertical field of view direction are as follows:
When visual field deflection in vertical field of view is 0 degree, presetting detection range is D；
When visual field deflection in vertical field of view is greater than 0 degree, default detection range DH is arranged to
Wherein, α is the visual field deflection in vertical field of view, and H is the visual field side in 0 degree of vertical field of view of the laser radarTo angle direction and the preset laser radar maximum probe height corresponding to vertical range between position；
When visual field deflection in vertical field of view is less than 0 degree, default detection range DL is arranged to
Wherein, α is the visual field deflection in vertical field of view, and L is the transmitting of laser radar described in the direction along vertical field of view systemThe mounting height of system.
Optionally, the default detection range setting on the vertical field of view direction are as follows:
When visual field deflection in vertical field of view is 0 degree, presetting farthest detecting location corresponding to detection range is d；
When visual field deflection in vertical field of view is the visual field direction angle alpha max in maximum perpendicular visual field, detection range is presetCorresponding farthest detecting location is dh, presets detection range DH ' are as follows:
Wherein, direction and the preset laser of the H for the visual field deflection in 0 degree of vertical field of view of the laser radarVertical range between position corresponding to the maximum probe height of radar；
When visual field deflection in vertical field of view is the visual field direction angle alpha min in minimum vertical visual field, detection range is presetCorresponding farthest detecting location is dl, and default detection range DL ' is arranged to:
Wherein, L is the mounting height of laser radar emission system described in the direction along vertical field of view；
The envelope of farthest detecting location corresponding to default detection range on the vertical field of view direction be by d,The parabola of dh and dl.
Compared with prior art, technical solution of the present invention has the advantage that
In technical solution of the present invention, the light splitting ratio between each angle of diffraction of the diffraction optical element is arranged to,The ratio between each default detection range on the corresponding vertical field of view direction of each angle of diffraction.The diffraction opticsThe use of element can form multiple second detection light beams, by a laser so as to effectively reduce in laser radarThe quantity of laser achievees the purpose that reduce cost, simplifies structure, reduces installation difficulty；And the diffraction optical elementLight splitting ratio is arranged to, between each default detection range on the corresponding vertical field of view direction of each angle of diffractionRatio, that is to say, that the light splitting ratio of the diffraction optical element is arranged according to the detection demand of the laser radar, so as toIt is enough effectively to control the transmission power of the laser radar under the premise of guaranteeing default detection range, be conducive to optimize laser thunderThe resource allocation reached, be advantageously implemented detection range and energy consumption control take into account.
In optinal plan of the present invention, the diffraction optical element is Darman raster.Using Darman raster as the diffractionOptical element can be effectively reduced design difficulty, simplify design under the premise of meeting diffraction optical element light splitting proportion requirementProcess, to reduce the formation difficulty of the light-dividing device.
Specific embodiment
It can be seen from background technology that multi-line laser radar in the prior art has that with high costs, energy consumption is excessive.
Existing multi-line laser radar is to be arranged using multiple lasers and corresponding detector in vertical direction, withIncrease the investigative range and vertical field of view angular resolution in vertical direction.But swash since each detection channels requires oneLight device, therefore the higher cost of this laser radar；Moreover, because a detection channels include a laser, i.e., it is describedThe number of lasers for including in laser radar is quite a lot of, therefore also results in the problem that internal structure is complicated, installation difficulty is larger.
To solve the technical problem, the present invention provides a kind of emission system of laser radar, comprising: light source, the lightSource includes at least one laser, and the laser is for emitting the first detection light beam；Emit optical module, the transmitting opticsComponent is used to the first detection beam collimation be directional light；Diffraction optical element, the diffraction optical element swash describedCollimated is divided into the detection light beam of N beam second, institute per a branch of first detection light beam on the vertical field of view direction of optical radarThe light splitting ratio stated between each angle of diffraction of diffraction optical element is arranged to, and each angle of diffraction is corresponding described verticalThe ratio between each default detection range on visual field direction.
The use of the diffraction optical element can form multiple second detection light beams by a laser, so as toThe quantity for enough effectively reducing laser in laser radar achievees the purpose that reduce cost, simplifies structure, reduces installation difficulty；AndAnd the light splitting ratio of the diffraction optical element is arranged to, on the corresponding vertical field of view direction of each angle of diffractionRatio between each default detection range, that is to say, that the light splitting ratio of the diffraction optical element is according to the laser radarThe setting of detection demand, so as to effectively control the transmitting of the laser radar under the premise of guaranteeing default detection rangePower, be conducive to optimize laser radar resource allocation, be advantageously implemented detection range and energy consumption control take into account.
To make the above purposes, features and advantages of the invention more obvious and understandable, with reference to the accompanying drawing to the present inventionSpecific embodiment be described in detail.
With reference to Fig. 1, the light channel structure schematic diagram of one embodiment of emission system of laser radar of the present invention is shown.
The emission system of the laser radar includes:
Light source 110, the light source 110 include at least one laser 111, and the laser 111 is visited for emitting firstSurvey light beam 112；Emit optical module 120, the transmitting optical module 120, which is used to collimate the first detection light beam 112, isDirectional light；Diffraction optical element 130, the diffraction optical element 130 will be through on the vertical field of view direction of the laser radarCollimation is divided into the detection light beam 131 of N beam second per a branch of first detection light beam 112.
The use of the diffraction optical element 130 can form multiple second detection light beams 131 by a laser,So as to effectively reduce the quantity of laser 111 in laser radar, reaching reduces cost, simplifies structure, reduces installation difficultyPurpose.
The light source 110 is used to generate the laser to be detected.
The light source 110 includes multiple lasers 111, and the laser 111 is pulse laser；Therefore, described to swashThe emission system of optical radar be multiline transmission system, i.e., the described laser radar be multi-line laser radar, and the light source 110 toThree-dimensional space transmitting is a series of pulse lasers.Specifically, the multiple laser 111 can be semiconductor laser, exampleSuch as edge-emission semiconductor laser or vertical-cavity-face emitting semiconductor laser.
Transmitting optical module 120 is for collimating laser caused by the light source 110.
Specifically, the transmitting optical module 120 includes at least one optical lens to realize the function of collimation.This implementationIn example, the transmitting optical module 120 includes at least one collimation lens.
Diffraction optical element 130 will be for that will be divided into multi beam second along vertical field of view direction per a branch of first detection light beam 112Detect light beam 131.
It should be noted that the emission system of the laser radar has shaft (not shown), institute in the present embodimentLight source 110, the transmitting optical module 120 and the diffraction optical element 130 is stated to rotate around the shaft 130.Specifically, packetIt includes the light source 110 of at least one laser 111, the transmitting optical module 120 including at least one optical lens and described spreads out130 entirety of optical element is penetrated around the shaft 130 in 360 ° of rotations.
In the present embodiment, the laser radar includes rotor (not shown), and the rotor is driven by bearing by motorIt is dynamic to be rotated around the shaft in 360 °.The light source 110, the transmitting optical module 120 and the diffraction optical element 130 are solidDue to (not shown) on one or more supporting bodies；The multiple supporting body fixing assembling is in the rotor.
The laser radar has the vertical field of view of the parallel shaft, and vertical field of view direction just refers to parallel described verticalThe direction of visual field, i.e. vertical field of view direction refer to along shaft extending direction.So the diffraction optical element 130 will be per a branch ofThe first detection light beam 112 is divided into multi beam second along shaft extending direction and detects light beam 131.
It should also be noted that, as shown in Figure 1, the light source 110 include an at least column laser 111, described at least oneColumn laser 111 is arranged along the vertical field of view direction of the laser radar, the optical axis and the laser of each laser 111Visual field direction angular direction in 0 degree of vertical field of view of radar is in different default angle, and the laser is along the laser thunderThe visual field direction angular direction in 0 degree of vertical field of view reached is axisymmetricly distributed.Wherein, 0 degree of vertical field of view of the laser radarInterior visual field direction angular direction is, in vertical field of view, the direction of the vertical shaft extension.
Make laser 111 along vertical field of view direction arrangement in column, and adjusts the light of each laser with predetermined angleAxis can make after the diffraction optical element 130 is divided, and various lasers 111 are formed by the column laser 111Second detection light beam 131 is separated from each other along vertical field of view direction, to expand vertical field of view range, is increased vertical field of view angle, is realizedThe purpose of field stitching.
Specifically, the angle difference between the default angle of adjacent laser is fixed value, to reduce the lightThe assembly difficulty in source 110.In the present embodiment, the angle difference is any fixation more than or equal to 0.1 degree and less than or equal to 5 degreeValue.In the reasonable scope by the difference control between the default angle, can not only make to be formed by the second detection light beam 131It is separated from each other along vertical field of view direction, but also the visual field after being divided between different angle of diffraction degree can be made adjacent, thus realThe purpose of existing field stitching.
In other embodiments of the invention, the angle difference between the default angle of adjacent laser is changing value,To cooperate different vertical field angle requirement.Specifically, being divided principle according to diffraction optical element, the angle difference is with describedIt presets the increase of angle and increases, to obtain the field angle of suitable size, and then achieve the effect that field stitching.
Diffraction optical element 130 is used as light-dividing device, and a laser 111 can be made to form multiple second detection light beams131；Therefore the use of the diffraction optical element 130 can have under the premise of guaranteeing the second detection 131 quantity of light beamEffect reduces the quantity of laser 111 in laser radar, achievees the purpose that reduce cost, simplifies structure, reduces installation difficulty.
In conjunction with reference Fig. 2, the signal of the vertical field of view of the embodiment of the emission system of laser radar shown in Fig. 1 is shownFigure.
Light splitting ratio between each angle of diffraction of the diffraction optical element 130 is arranged to, each angle of diffractionThe ratio between each default detection range on the corresponding vertical field of view direction.
The detection range of laser and the transmission power of laser are related, so that the energy consumption to laser radar is related；Therefore describedThe light splitting ratio of diffraction optical element 130 is arranged according to the detection demand of the laser radar, can guarantee default detection away fromFrom under the premise of, the transmission power of the laser radar is effectively controlled, is conducive to the resource allocation for optimizing laser radar, is conducive toWhat realization detection range and energy consumption controlled takes into account.
As shown in Fig. 2, the light splitting ratio between each angle of diffraction based on the diffraction optical element 130 is formed byDefault detection range of the two detection light beams on the vertical field of view direction is arranged to:
When visual field deflection in vertical field of view is 0 degree, presetting detection range is D；
When visual field deflection in vertical field of view is greater than 0 degree, default detection range DH is arranged to:
Wherein, α is the visual field deflection in vertical field of view, and H is the visual field side in 0 degree of vertical field of view of the laser radarTo angle direction and the preset laser radar maximum probe height corresponding to vertical range between position；
When visual field deflection in vertical field of view is less than 0 degree, default detection range DL is arranged to:
Wherein, α is the visual field deflection in vertical field of view, and L is the transmitting of laser radar described in the direction along vertical field of view systemThe mounting height of system.
Make splitting ratio such as this setting between each angle of diffraction of the diffraction optical element 130, can make through describedThe light splitting of diffraction optical element 130 is formed by front of the second detection light beam 131 in the vertical field of view with biggishDetection range, i.e., in vertical field of view, the second detection light beam 131 is in the region tool that visual field deflection is near 0 degree and 0 degreeThere is biggish detection range；Make it is described second detection light beam 131 in the vertical field of view above and below have it is lesserDetection range, i.e., in vertical field of view, the second detection light beam 131 has in the biggish region of vertical field of view deflection absolute valueHave relatively small detection range, so as to effectively control the laser radar in vertical field of view above and below distributeResource, avoid the laser radar wasting of resources.
In the present embodiment, the laser radar also has the horizontal field of view of the vertical vertical field of view.Specifically, described swashOptical radar has a shaft, the vertical field of view shaft in parallel, the vertical vertical field of view of the horizontal field of view, therefore describedThe vertical shaft extending direction of horizontal field of view；Moreover, the visual field direction angular direction in 0 degree of vertical field of view of the laser radarFor, in vertical field of view, the direction of the vertical shaft extension, it can be seen that, when the visual field deflection in vertical field of view is 0 degreeDefault detection range D is equal with the default detection range of the horizontal field of view.
In the present embodiment, the default detection range of the horizontal field of view is related to the visual field deflection in horizontal field of view, instituteWith, default detection range D when visual field deflection in the vertical field of view is 0 degree also with the visual field side in the horizontal field of viewTo angle correlation.
In default detection range D and horizontal field of view when making 0 degree of visual field deflection in the vertical field of viewVisual field deflection is related, so as to combine the detection demand of horizontal field of view to realize the further excellent of laser radar resource allocationChange, energy dissipation can be further decreased from the angle of three-dimensional space, be bonded the default detection range of the laser radar moreUnpiloted demand.
In addition, in the present embodiment, the light source 110, the transmitting optical module 120 and the diffraction optical element 130It is set in the rotor of laser radar and is rotated around the shaft, therefore the rotational angle of the rotor and the second detection light beamThe 131 visual field deflection in the horizontal field of view is related.
It should also be noted that, in the present embodiment, the laser radar emission system further include: code-disc (does not show in figureOut), the code-disc can obtain the rotational angle of the rotor, so the code-disc can also be used to obtain in horizontal field of viewVisual field deflection.
Specifically, in the horizontal field of view, the setting of the search coverage of the laser radar have front and back it is asymmetric, onUnder asymmetric feature；Therefore the default detection range in the horizontal field of view is arranged to: the visual field in the horizontal field of viewWhen deflection is 0 degree (front of laser radar, and load the front of the vehicle of laser radar), detection range is presetFor F；When visual field deflection in the horizontal field of view is 180 degree (dead astern of laser radar, and load laser radarThe dead astern of vehicle), presetting detection range is R；When visual field deflection in the horizontal field of view is θ, detection range D is presetAre as follows:
So when the visual field deflection in the horizontal field of view is 0 degree, a series of laser caused by the light source 110Farthest detecting location be f point；When visual field deflection in the horizontal field of view is 180 degree, one caused by the light source 110The farthest detecting location of series laser is r point；The center of the laser radar is o point；It is farthest in the horizontal field of viewDetecting location is formed by envelope to be a focus with o point, and by the ellipse of f point and r point, and wherein f point and r point are located atOn the elliptical long axis, and f point is greater than the distance of r point to o point to the distance of o point.
In addition, the default detection range DH in the horizontal field of view and the visual field deflection dynamic phase in the horizontal field of viewIt closes, therefore, the visual field deflection in default detection range D and horizontal field of view when the visual field deflection in vertical field of view is 0 degreeAlso dynamical correlation advanced optimizes laser radar so as to require reasonable distribution laser radar resource for different detectionsResource allocation, to achieve the purpose that take into account detection range and energy consumption control.
It should be noted that the visual field when the laser radar is applied to unmanned field, in the vertical field of viewDeflection is the direction of advance that 0 degree of direction is unmanned automobile, and it is to be directed toward day that the visual field deflection in vertical field of view, which is ± 90 degree,The direction in empty direction and direction ground, so making the light splitting ratio between each angle of diffraction of the diffraction optical element 130Above-mentioned setting enables to the search coverage of laser radar closer in the detection demand in unmanned field, realizes energy consumption and spySurvey demand is taken into account.
It should also be noted that, as shown in Fig. 2, the laser radar is applied to unmanned field, institute in the present embodimentThe mounting height for stating laser radar refers to, between the direction and ground that the visual field deflection in vertical field of view is 0 degree it is vertical away fromFrom.
It can be seen that as shown in Fig. 2, light splitting ratio between each angle of diffraction based on the diffraction optical element 130Default detection range of the second detection light beam on the vertical field of view direction is formed by be arranged to:
When visual field deflection in vertical field of view is 0 degree, presetting farthest detecting location corresponding to detection range is d；
When visual field deflection in vertical field of view is the visual field direction angle alpha max in maximum perpendicular visual field, detection range is presetCorresponding farthest detecting location is dh, presets detection range DH ' are as follows:
Wherein, direction and the preset laser of the H for the visual field deflection in 0 degree of vertical field of view of the laser radarVertical range between position corresponding to the maximum probe height of radar；
When visual field deflection in vertical field of view is the visual field direction angle alpha min in minimum vertical visual field, detection range is presetCorresponding farthest detecting location is dl, and default detection range DL ' is arranged to:
Wherein, L is the mounting height of laser radar emission system described in the direction along vertical field of view.
SoWhen in range, the pre-determined distance institute on vertical field of view direction is rightDefault detection range when the BURN-THROUGH RANGE answered and the visual field deflection in vertical field of view are 0 degree is equal；?WithWhen in range, the pre-determined distance institute on vertical field of view direction is rightThe BURN-THROUGH RANGE answered is related to the visual field deflection in the vertical field of view.
It should be noted that the default detection range institute on the vertical field of view direction is right in other embodiments of the inventionThe envelope of the farthest detecting location answered is the parabola by d, dh and dl, is set with reducing the emission system of laser radarDifficulty and control difficulty are counted, manufacturing cost is controlled.
It should also be noted that, the diffraction optical element 130 is set as grating in the present embodiment, guaranteeing light splitting effectUnder the premise of fruit, simplifies the structure of the diffraction optical element 130, reduce the complexity of the laser radar optical path.
Specifically, the diffraction optical element 130 is set as Darman raster.Using Darman raster as the diffraction opticsDesign difficulty can be effectively reduced, simplification is set under the premise of meeting the light splitting proportion requirement of diffraction optical element 130 in element 130Meter process, to reduce the manufacture difficulty of beam splitter.
So in the present embodiment, the direction of the visual field deflection in 0 degree of vertical field of view of the laser radar with it is presetVertical range H between position corresponding to the maximum probe height of the laser radar is 4 meters, described in the direction along vertical field of viewThe mounting height L of laser radar emission system is 4 meters, and when the visual field deflection in vertical field of view is 0 degree, default detection range is50m.In addition, the vertical field of view of the laser radar is distributed in the range of vertical field of view deflection ± 30 degree.The diffraction lightIt learns element 130 and is set as the binary Darman raster that light splitting angle is 8 °.
In conjunction with reference Fig. 3, diffraction optical element described in the emission system embodiment of laser radar shown in Fig. 1 is shown130 best light splitting ratio.
Wherein, horizontal axis indicates to form the angle of diffraction of the second detection light beam 131, and the longitudinal axis indicates light splitting ratio.As it can be seen thatAngle of diffraction is relatively small, i.e., on the direction that visual field deflection is 0 degree, is divided large percentage, forms the second detection light beam131 light intensity is larger, and forming the second detection light beam 131 has biggish default detection range；It is relatively large in angle of diffraction,I.e. on the direction that visual field deflection is ± 30 degree, light splitting ratio is smaller, and the light intensity for forming the second detection light beam 131 is smaller,Forming the second detection light beam 131 has lesser default detection range.
The design parameter reference table 1 of the diffraction optical element 130.
Table 1
It is formed by binary Darman raster based on above-mentioned design parameter, the light splitting of the diffraction optical element 130 can be madeRatio is arranged according to the detection demand of the laser radar, so as to effectively control under the premise of guaranteeing default detection rangeThe transmission power for making the laser radar is conducive to the resource allocation for optimizing laser radar, is advantageously implemented detection range and energyConsumption control takes into account.
Correspondingly, the present invention also provides a kind of laser radars.
The laser radar includes: emission system, and the emission system is
Emission system of the invention；Reception system, the reception system receive the second detection light beam in three-dimensional spaceInterior reflected light.
With reference to Fig. 1, the structural schematic diagram of one embodiment of laser radar of the present invention is shown.
The emission system of the laser radar is emission system of the invention.The emission system of the laser radar it is specificEmbodiment of the technical solution with reference to the emission system of aforementioned laser radar.Details are not described herein by the present invention.
In conjunction with reference Fig. 2, the schematic diagram of the vertical field of view of the embodiment of laser radar as shown in Figure 1 is shown.
As shown in Fig. 2, the diffraction optical element 130 is in the laser radar in the emission system of the laser radarVertical field of view direction on be divided into N beam second by collimated per a branch of first detection light beam 112 and detect light beam 131, instituteThe light splitting ratio stated between each angle of diffraction of diffraction optical element 130 is arranged to, and each angle of diffraction is corresponding describedThe ratio between each default detection range on vertical field of view direction.
It is realized and is divided by the diffraction optical element 130, multiple second can not only be formed by a laser 111Detect light beam 131, so as to effectively reduce the quantity of laser 111 in laser radar, reach reduce cost, simplify structure,Reduce the purpose of installation difficulty；And the light splitting ratio of the diffraction optical element 130 is needed according to the detection of the laser radarSetting is asked, so as to effectively control the transmission power of the laser radar, favorably under the premise of guaranteeing default detection rangeIn optimization laser radar resource allocation, be advantageously implemented detection range and energy consumption control take into account.
In addition, the laser radar further include: receive system (not shown), the reception system receives the transmittingA series of reflected light of laser in three-dimensional space caused by system.
In the present embodiment, the reception system includes: reception optical module, and the reception optical module is for receiving and convergingGather the reflected light；Detection device, the detection device include at least one detector, and the detector is used for received to instituteReflected light carries out photoelectric conversion.
It should be noted that the specific structure of the reception system of above-mentioned laser radar is only an example, other realities of the inventionIt applies in example, the laser radar can also include other elements, and the present invention does not limit this.
In addition, the present invention also provides a kind of design methods of the emission system of laser radar.
It with reference to Fig. 1, shows in one embodiment of control method of the emission system of laser radar of the present invention, the laser thunderThe structural schematic diagram of the emission system reached.
The emission system of the laser radar includes: light source 110, and the light source 110 includes at least one laser 111,The laser 111 is for emitting the first detection light beam 112；Emit optical module 120, the transmitting optical module 120 is used forThe first detection light beam 112 is collimated as directional light；Diffraction optical element 130, the diffraction optical element 130 swash describedCollimated is divided into the detection light beam of N beam second per a branch of first detection light beam 112 on the vertical field of view direction of optical radar131。
Wherein, the light source 110 is used to generate the laser to be detected.
The light source 110 includes multiple lasers 111, and the laser 111 is pulse laser；Therefore, described to swashThe emission system of optical radar be multiline transmission system, i.e., the described laser radar be multi-line laser radar, and the light source 110 toThree-dimensional space transmitting is a series of pulse lasers.Specifically, the multiple laser 111 can be semiconductor laser, exampleSuch as edge-emission semiconductor laser or vertical-cavity-face emitting semiconductor laser.
Transmitting optical module 120 is for collimating laser caused by the light source 110.
Specifically, the transmitting optical module 120 includes at least one optical lens to realize the function of collimation.This implementationIn example, the transmitting optical module 120 includes at least one collimation lens.
Diffraction optical element 130 will be for that will be divided into multi beam second along vertical field of view direction per a branch of first detection light beam 112Detect light beam 131.
It should be noted that the emission system of the laser radar has shaft (not shown), institute in the present embodimentLight source 110, the transmitting optical module 120 and the diffraction optical element 130 is stated to rotate around the shaft.Specifically, includingThe light source 110 of at least one laser 111, the transmitting optical module 120 including at least one optical lens and the diffractionOptical element 130 is whole to be rotated around the shaft in 360 °.
In the present embodiment, the laser radar includes rotor (not shown), and the rotor is driven by bearing by motorIt is dynamic to be rotated around the shaft in 360 °.The light source 110, the transmitting optical module 120 and the diffraction optical element 130 are solidDue to (not shown) on one or more supporting bodies；The multiple supporting body fixing assembling is in the rotor.
The laser radar has the vertical field of view of the parallel shaft, and vertical field of view direction just refers to parallel described verticalThe direction of visual field, i.e. vertical field of view direction refer to along shaft extending direction.So the diffraction optical element 130 will be per a branch ofThe first detection light beam 112 is divided into multi beam second along shaft extending direction and detects light beam 131.
It should also be noted that, as shown in Figure 1, the light source 110 includes at least during the light source 110 is arrangedOne column laser 111, an at least column laser 111 are arranged along the vertical field of view direction of the laser radar, each describedThe optical axis of laser 111 is in different default angles from the visual field direction angular direction in 0 degree of vertical field of view of the laser radar,And visual field direction angular direction of the laser in 0 degree of vertical field of view of the laser radar is axisymmetricly distributed.Wherein, instituteThe visual field direction angular direction stated in 0 degree of vertical field of view of laser radar is, in vertical field of view, the side of the vertical shaft extensionTo.
Make laser 111 along vertical field of view direction arrangement in column, and adjusts the light of each laser with predetermined angleAxis can make after the diffraction optical element 130 is divided, and various lasers 111 are formed by the column laser 111Second detection light beam 131 is separated from each other along vertical field of view direction, to expand vertical field of view range, is increased vertical field of view angle, is realizedThe purpose of field stitching.
Specifically, the angle difference between the default angle of adjacent laser is fixed value, to reduce the lightThe assembly difficulty in source 110.In the present embodiment, the angle difference is any fixation more than or equal to 0.1 degree and less than or equal to 5 degreeValue.In the reasonable scope by the difference control between the default angle, can not only make to be formed by the second detection light beam 131It is separated from each other along vertical field of view direction, but also the visual field after being divided between different angle of diffraction degree can be made adjacent, thus realThe purpose of existing field stitching.
In other embodiments of the invention, the angle difference between the default angle of adjacent laser is changing value,To cooperate different vertical field angle requirement.Specifically, according to diffraction optical element 130 be divided principle, the angle difference withThe increase of the default angle and increase, to obtain the field angle of suitable size, and then achieve the effect that field stitching.
The diffraction optical element 130 is set as light-dividing device, a laser 111 can be made to form multiple second and visitedSurvey light beam 131；Therefore the use of the diffraction optical element 130 can be before guaranteeing the second detection 131 quantity of light beamIt puts, effectively reduces the quantity of laser 111 in laser radar, reach the mesh for reducing cost, simplifying structure, reducing installation difficulty's.
The design method includes: that the light splitting ratio between each angle of diffraction of the diffraction optical element 130 is set asThe ratio between each default detection range on the corresponding vertical field of view direction of each angle of diffraction.
In conjunction with reference Fig. 2, the signal of the vertical field of view of the embodiment of the emission system of laser radar shown in Fig. 1 is shownFigure.
The detection range of laser and the transmission power of laser are related, so that the energy consumption to laser radar is related；Therefore describedThe light splitting ratio of diffraction optical element 130 is arranged according to the detection demand of the laser radar, can guarantee default detection away fromFrom under the premise of, the transmission power of the laser radar is effectively controlled, is conducive to the resource allocation for optimizing laser radar, is conducive toWhat realization detection range and energy consumption controlled takes into account.
As shown in Fig. 2, it includes: institute that the step of being divided ratio, which is arranged between each angle of diffraction of the diffraction optical element 130,State the default detection range setting on vertical field of view direction are as follows:
When visual field deflection in vertical field of view is 0 degree, presetting detection range is D；
When visual field deflection in vertical field of view is greater than 0 degree, detection range DH setting is preset are as follows:
Wherein, α is the visual field deflection in vertical field of view, and H is the visual field side in 0 degree of vertical field of view of the laser radarTo angle direction and the preset laser radar maximum probe height corresponding to vertical range between position；
When visual field deflection in vertical field of view is less than 0 degree, detection range DL setting is preset are as follows:
Wherein, α is the visual field deflection in vertical field of view, and L is the transmitting of laser radar described in the direction along vertical field of view systemThe mounting height of system.
The way of the above-mentioned setting light splitting ratio, can make to be divided through the diffraction optical element 130 and be formed by theTwo fronts of the detection light beams 131 in the vertical field of view have biggish detection range, i.e., in vertical field of view, described theTwo detection light beams 131 are that 0 degree and 0 degree neighbouring region has biggish detection range in visual field deflection；Described second is set to visitSurvey light beam 131 in the vertical field of view above and below there is lesser detection range, i.e., in vertical field of view, described theTwo detection light beams 131 have relatively small detection range in the biggish region of vertical field of view deflection absolute value, so as toEffectively control the laser radar in vertical field of view above and below the resource distributed, avoid the laser radar wasting of resources.
In the present embodiment, the laser radar also has the horizontal field of view of the vertical vertical field of view.Specifically, described swashOptical radar has a shaft, the vertical field of view shaft in parallel, the vertical vertical field of view of the horizontal field of view, therefore describedThe vertical shaft extending direction of horizontal field of view；Moreover, the visual field direction angular direction in 0 degree of vertical field of view of the laser radarFor, in vertical field of view, the direction of the vertical shaft extension, it can be seen that, when the visual field deflection in vertical field of view is 0 degreeDefault detection range D is equal with the default detection range of the horizontal field of view.
In the present embodiment, the default detection range of the horizontal field of view is related to the visual field deflection in horizontal field of view, instituteThe step of being divided ratio is arranged between each angle of diffraction of the diffraction optical element 130 further include: according in horizontal field of viewVisual field deflection adjusts a series of generated default detection range of laser in the horizontal field of view.
In default detection range D and horizontal field of view when making 0 degree of visual field deflection in the vertical field of viewVisual field deflection is related, so as to combine the detection demand of horizontal field of view to realize the further excellent of laser radar resource allocationChange, energy dissipation can be further decreased from the angle of three-dimensional space, be bonded the default detection range of the laser radar moreUnpiloted demand.
In addition, in the present embodiment, the light source 110, the transmitting optical module 120 and the diffraction optical element 130It is set in the rotor of laser radar and is rotated around the shaft, therefore the rotational angle of the rotor and the second detection light beamThe 131 visual field deflection in the horizontal field of view is related.
It should also be noted that, in the present embodiment, the laser radar emission system further include: code-disc (does not show in figureOut), the code-disc can obtain the rotational angle of the rotor, so the code-disc can also be used to obtain in horizontal field of viewVisual field deflection.
Specifically, in the horizontal field of view, the setting of the search coverage of the laser radar have front and back it is asymmetric, onUnder asymmetric feature；Therefore a series of generated laser are adjusted in the level according to the visual field deflection in horizontal field of viewDefault detection range setting in the step of default detection range in visual field, in the horizontal field of view are as follows: the horizontal field of viewWhen interior visual field deflection is 0 degree (front of laser radar, and load the front of the vehicle of laser radar), presetDetection range is F；When visual field deflection in the horizontal field of view is 180 degree (dead astern of laser radar, and load and swashThe dead astern of the vehicle of optical radar), presetting detection range is R；When visual field deflection in the horizontal field of view is θ, presets and visitRanging is from D are as follows:
So when the visual field deflection in the horizontal field of view is 0 degree, a series of laser caused by the light source 110Farthest detecting location be f point；When visual field deflection in the horizontal field of view is 180 degree, one caused by the light source 110The farthest detecting location of series laser is r point；The center of the laser radar is o point；It is farthest in the horizontal field of viewDetecting location is formed by envelope to be a focus with o point, and by the ellipse of f point and r point, and wherein f point and r point are located atOn the elliptical long axis, and f point is greater than the distance of r point to o point to the distance of o point.
In addition, the default detection range DH in the horizontal field of view and the visual field deflection dynamic phase in the horizontal field of viewIt closes, therefore, the visual field deflection in default detection range D and horizontal field of view when the visual field deflection in vertical field of view is 0 degreeAlso dynamical correlation advanced optimizes laser radar so as to require reasonable distribution laser radar resource for different detectionsResource allocation, to achieve the purpose that take into account detection range and energy consumption control.
It should be noted that the visual field when the laser radar is applied to unmanned field, in the vertical field of viewDeflection is the direction of advance that 0 degree of direction is unmanned automobile, and it is to be directed toward day that the visual field deflection in vertical field of view, which is ± 90 degree,The direction in empty direction and direction ground, so making the light splitting ratio between each angle of diffraction of the diffraction optical element 130Above-mentioned setting enables to the search coverage of laser radar closer in the detection demand in unmanned field, realizes energy consumption and spySurvey demand is taken into account.
With continued reference to Fig. 2, in the present embodiment, the laser radar is applied to unmanned field, the laser radarMounting height refers to, the vertical range between direction and ground that the visual field deflection in vertical field of view is 0 degree.
It can be seen that as shown in Fig. 2, the step for being divided ratio between each angle of diffraction of the diffraction optical element 130 is arrangedIn rapid, the light splitting ratio between each angle of diffraction based on the diffraction optical element 130 is formed by the second detection light beam and existsDefault detection range setting on the vertical field of view direction are as follows:
When visual field deflection in vertical field of view is 0 degree, presetting farthest detecting location corresponding to detection range is d；
When visual field deflection in vertical field of view is the visual field direction angle alpha max in maximum perpendicular visual field, detection range is presetCorresponding farthest detecting location is dh, presets detection range DH ' are as follows:
Wherein, direction and the preset laser of the H for the visual field deflection in 0 degree of vertical field of view of the laser radarVertical range between position corresponding to the maximum probe height of radar；
When visual field deflection in vertical field of view is the visual field direction angle alpha min in minimum vertical visual field, detection range is presetCorresponding farthest detecting location is dl, presets detection range DL ' setting are as follows:
Wherein, L is the mounting height of laser radar emission system described in the direction along vertical field of view.
SoWhen in range, the pre-determined distance institute on vertical field of view direction is rightDefault detection range when the BURN-THROUGH RANGE answered and the visual field deflection in vertical field of view are 0 degree is equal；?WithWhen in range, the pre-determined distance institute on vertical field of view direction is rightThe BURN-THROUGH RANGE answered is related to the visual field deflection in the vertical field of view.
It should be noted that being arranged between each angle of diffraction of the diffraction optical element 130 in other embodiments of the inventionIn the step of light splitting ratio, the envelope of farthest detecting location corresponding to the default detection range on the vertical field of view directionTo be made with reducing design difficulty and control difficulty, the control of the emission system of laser radar by the parabola of d, dh and dlCause this.
In the present embodiment, the step of light splitting ratio setting between each angle of diffraction of the diffraction optical element 130 in,Grating is set by the diffraction optical element 130, to simplify the diffraction optics member under the premise of guaranteeing spectrophotometric resultThe structure of part 130 reduces the complexity of the laser radar optical path.
Specifically, the step of setting grating for the diffraction optical element 130 includes: by the diffraction optical element130 are set as Darman raster, so the step of light splitting ratio setting between each angle of diffraction of the diffraction optical element 130It include: the light splitting ratio that the design principle based on Darman raster is arranged between each angle of diffraction of the diffraction optical element 130To reduce design difficulty, design processes simplified, to reduce the manufacture difficulty of beam splitter.
In the present embodiment, the direction of the visual field deflection in 0 degree of vertical field of view of the laser radar with it is preset describedVertical range H between position corresponding to the maximum probe height of laser radar is 4 meters, laser described in the direction along vertical field of viewThe mounting height L of radar emission system is 4 meters, and when the visual field deflection in vertical field of view is 0 degree, presetting detection range is 50m.In addition, the vertical field of view of the laser radar is distributed in the range of vertical field of view deflection ± 30 degree.The diffraction optics memberPart 130 is set as the binary Darman raster that light splitting angle is 8 °.
In conjunction with reference Fig. 3, diffraction optical element described in the emission system embodiment of laser radar shown in Fig. 1 is shown130 best light splitting ratio.
Wherein, horizontal axis indicates to form the angle of diffraction of the second detection light beam 131, and the longitudinal axis indicates light splitting ratio.As it can be seen thatAngle of diffraction is relatively small, i.e., on the direction that visual field deflection is 0 degree, is divided large percentage, forms the second detection light beam131 light intensity is larger, and forming the second detection light beam 131 has biggish default detection range；It is relatively large in angle of diffraction,I.e. on the direction that visual field deflection is ± 30 degree, light splitting ratio is smaller, and the light intensity for forming the second detection light beam 131 is smaller,Forming the second detection light beam 131 has lesser default detection range.
So in the present embodiment, the design parameter of the diffraction optical element 130 refers to aforementioned table 1, and the present invention is herein notIt repeats again.
Although present disclosure is as above, present invention is not limited to this.Anyone skilled in the art are not departing from thisIt in the spirit and scope of invention, can make various changes or modifications, therefore protection scope of the present invention should be with claim instituteSubject to the range of restriction.