WO2018068363A1

WO2018068363A1 - Laser radar optical system

Info

Publication number: WO2018068363A1
Application number: PCT/CN2016/106372
Authority: WO
Inventors: 张正正; 屈志巍; 佟健; 李娟娟
Original assignee: 北京万集科技股份有限公司
Priority date: 2016-10-12
Filing date: 2016-11-18
Publication date: 2018-04-19
Also published as: CN106291509A; CN106291509B

Abstract

A laser radar optical system, comprising a laser transmitting device (100), a laser receiving device (200), and an adjusting unit. The laser transmitting device (100) comprises a first laser light source (110), a second laser light source (120), a first beam splitter (130), and a zoom collimator lens group (140). The laser receiving device (200) comprises a first detector (210), a second detector (220), a second beam splitter (230), and a zoom condenser lens group (240). The adjusting unit is used for adjusting focal lengths of the zoom collimator lens group (140) and the zoom condenser lens group (240). The laser radar optical system can implement switching between a near field of view and a far field of view by controlling the switching of the first laser light source (110) and the second laser light source (120), the switching of the first detection (210) and the second detector (220), and focal length conversions of the zoom collimator lens group (140) and the zoom condenser lens group (240), so that the optical system is switched to a near field mode when near-field scan needs to be performed, and is switched to a far field mode when far-field scan needs to be performed, in order to meet the requirements of different fields of view and resolutions.

Description

Lidar optical system

cross reference

The present application is hereby incorporated by reference in its entirety in its entirety in its entirety in its entirety in the the the the the the the the the

Technical field

The present invention relates to the field of laser radar technology, and in particular to a laser radar optical system.

Background technique

With the advancement of technology, people have higher requirements for vehicle safety, and laser radar technology has been widely used. The laser radar transmitting system projects the laser beam to the target, and the target surface is scattered back to a laser beam and is received by the laser radar receiving system. The distance between the laser radar and the target is calculated by the time difference between the laser beam and the transmission.

Prior known lidar systems detect targets within a predetermined range with a fixed field of view and resolution. Since the field of view and resolution of the lidar system are fixed, there is a contradiction between near-field scanning and far-field scanning. If the field of view and resolution of the lidar system meet the observation of the target in the far field range, the field of view of the laser radar system in the near-field range is narrowed, covering only a part of the target, and cannot be in the near-field range of the front of the detector. The object space is effectively detected. If the field of view and resolution of the lidar system meet the observation of the target in the near-field range, the scanning line field of the lidar system in the far field will be much larger than the target to be measured, and part of the field of view will be higher than the field to be tested. Target, the spatial information in this part of the field of view is not useful for the vehicle, and the field of view of the lidar cannot be fully utilized. At the same time, in the case where the near field satisfies the detection requirements, the resolution of the far-field lidar becomes low, and there is a large blind zone between adjacent scan paths, which causes the lidar system to detect the target within the specified range insufficiently. Give accurate information about the target to be tested.

For example, Figure 1 is a schematic diagram of the vertical field of view and resolution of an existing lidar in the near and far fields. The number of scanning lines of the laser radar in the vertical direction is N, the near field scanning field of the laser radar is α, the near field scanning resolution is α/(N-1), and the near field range of the laser radar is 0 to L1. The scanning field of the laser radar in the vertical direction at L1 is approximately H1=L1×tanα, and the scanning resolution in the vertical direction of the object is h1=H1/(N-1). At this time, in the range of the near field in front of the vehicle, the laser radar satisfies the appropriate scanning range, and also ensures the fineness of the near field scanning. In the case of this near-field mode, the scanning line field of the laser radar at the far field L2 is approximately H2 = L2 × tan α, and the object-side scanning resolution is h2 = H2 / (N - 1). Since L2 is 3 to 5 times or even 10 times that of L1, H2 is much larger than H1. At this time, the upper scanning field of the lidar is already above the vehicle in front, and the detection field of the lidar is beyond the actual available. The scope causes a large part of the field of view to be wasted. At the same time, h2 is much larger than h1, and h2 is 3 to 5 times or even 10 times that of h1. Since the laser radar does not have sufficient vertical scanning resolution, there is a large dead zone between adjacent two scans.

The far field range of the laser radar is L1～L2. When the laser radar is in the far field mode, the vertical field of the laser radar far field scans the field of view as β, and the scanning resolution is β/(N 1). The line field of view scanned at L2 is H3=L2×tanβ, and the object side scanning resolution is h3=H3/(N-1). The laser radar detects the far-field target in front of the vehicle, satisfies the fineness of the far-field scanning of the laser radar, and also ensures sufficient vertical scanning of the field of view. However, in the case of far-field mode, the scanning line field of the lidar at near-field L1 is H4=L1×tanβ, and the object-side scanning resolution is h4=H4/(N-1), since L2 is L1 of L1. 5 times, even 10 times, so H4 is much smaller than H3. In the case that H3 satisfies the scanning field of view, H4 is much smaller than the actual scanning range. Only a small part of the vehicle in front of the detector can be detected. Sufficient object space information can not meet the needs of the field of view in the near field.

It can be seen that the laser radar that satisfies the requirements of the near field of view is not suitable for the far field of view scanning, and the laser radar that satisfies the requirements of the far field is not suitable for the near field scanning, so a need is needed. The laser radar optical system that switches the field of view to meet the requirements for different fields of view and resolution.

Summary of the invention

In view of the above drawbacks, the present invention provides a laser radar optical system that can switch between a near field of view and a far field of view to meet different fields of view and resolution requirements.

The laser radar optical system provided by the invention comprises a laser emitting device, a laser receiving device and an adjusting unit, wherein:

The laser emitting device includes a first laser light source, a second laser light source, a first beam splitting device, and a zoom collimating lens set, wherein the first beam splitting device is disposed at a position suitable for causing the laser light emitted by the first laser source to be After being reflected on the first beam splitting device, entering the zoom collimating mirror group and causing the laser light emitted by the second laser source to be transmitted on the first beam splitting device to enter the zoom collimating mirror group, the zooming standard The straight lens group is configured to collimate the received laser light and project it into a field of view corresponding to a current focal length of the zoom collimating lens group;

The laser receiving device includes a first detector, a second detector, a second beam splitting device, and a zooming convergence lens group, the zooming condenser lens group is configured to view a field of view corresponding to a current focal length of the zooming convergence lens group The laser light scattered back in the range is concentrated, and the second light splitting device is disposed at a position suitable for the laser light concentrated by the zooming convergence lens group to be reflected on the second light splitting device to enter the first detector and The laser concentrated by the zooming convergence lens group is transmitted on the second beam splitting device and then enters the second detector;

The adjusting unit is configured to adjust a focal length of the zoom collimating mirror group and the zoom converging mirror group.

Optionally, the system further includes:

a first filter disposed between the first detector and the second beam splitting device for suppressing interference of external stray light to the first detector; and/or

And a second filter disposed between the second detector and the second beam splitting device for suppressing interference of external stray light to the second detector.

Optionally, the first laser and the second laser are adapted to emit the same wavelength The laser, the first beam splitting device and the second beam splitting device are neutral beamsplitters.

Optionally, the central beam splitter has a split ratio of 0.5 to 0.9.

Optionally, the first laser and the second laser are adapted to emit laser light of different wavelengths, and the first light splitting device and the second light splitting device are two-color spectroscopes.

Optionally, the zoom collimating mirror group and/or the zoom converging mirror group comprises a liquid lens, a positive lens and a negative lens.

Optionally, the first laser source and/or the second laser source comprise a plurality of semiconductor lasers or an array laser arranged in an array.

Optionally, the first detector and/or the second detector comprise a plurality of avalanche diodes arranged in an array or an array of avalanche diodes.

Optionally, the light emitting surface of the first laser light source matches the size of the photosensitive receiving surface of the first detector, and/or the light emitting surface of the second laser light source and the second detector The size of the photosensitive receiving surface matches.

Optionally, the laser emitting device and the laser receiving device are distributed on both sides of a central axis of the optical system.

The optical system provided by the invention can control the switching between the first laser source and the second laser source, the switching of the first detector and the second detector, and the focal length conversion of the zoom collimating mirror group and the zoom converging mirror group. Switching between the near field of view and the far field of view enables the optical system to switch to near-field mode when near-field scanning is required, and to far-field mode when far-field scanning is required to meet different fields of view and resolution Claim.

DRAWINGS

In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the drawings to be used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description are only It is some embodiments of the present disclosure, and other drawings may be obtained from those of ordinary skill in the art without any inventive effort.

Figure 1 is a schematic view showing the near and far field of view of the existing laser radar in the vertical direction;

2 is a schematic structural view of a laser radar optical system according to an embodiment of the present invention;

3 is a schematic view showing a laser emitting device in a near field mode according to an embodiment of the present invention;

4 is a schematic view showing a laser receiving apparatus in a near field mode according to an embodiment of the present invention;

FIG. 5 is a schematic view showing a laser radar optical system in a near field mode according to an embodiment of the present invention; FIG.

6 is a schematic view showing a laser radar optical system in a far field mode according to an embodiment of the present invention;

Description of the reference signs:

100-laser emitting device; 110-first laser source; 120-second laser source; 130-first beam splitting device; 140-zoom collimating mirror group; 141-lens collimating lens group liquid lens; 142-negative lens ;143-positive lens;

200-laser receiving device; 210-first detector; 220-second detector; 230-second beam splitting device; 240-zooming condenser lens group; 241-finishing lens group liquid lens; 242-zooming condenser lens group Negative lens; 243- positive lens of the zoom condenser lens; 251-first filter; 252-second filter;

300-the central axis of the laser radar optical system; 301 - the central axis of the laser emitting device; 302 - the central axis of the laser receiving device.

detailed description

The technical solutions in the embodiments of the present disclosure are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present disclosure. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present disclosure without departing from the inventive scope are the scope of the disclosure.

The present invention provides a laser radar optical system, as shown in FIG. 2, the system includes a laser emitting device 100, a laser receiving device 200, and an adjustment unit, wherein:

The laser emitting device 100 includes a first laser light source 110, a second laser light source 120, a first beam splitting device 130, and a zoom collimating lens group 140, and the first beam splitting device 130 is disposed at a position suitable for the first laser light. The laser light emitted by the light source 110 is reflected on the first beam splitting device 130, enters the zoom collimating lens group 140, and transmits the laser light emitted by the second laser light source 120 on the first beam splitting device 130. The zoom collimating lens group 140 is configured to collimate the received laser light and project it into a field of view corresponding to a current focal length of the zoom collimating lens group 140;

The laser receiving device 200 includes a first detector 210, a second detector 220, a second beam splitting device 230, and a zooming condenser group 240, and the zooming condenser group 240 is used to present the current of the zooming condenser group 240. The laser light scattered back in the field of view corresponding to the focal length is concentrated, and the second beam splitting device 230 is disposed at a position suitable for the laser light concentrated by the zooming condenser group 240 to be reflected on the second beam splitting device 230. The laser entering the first detector 210 and concentrating the zooming condenser group 240 is transmitted on the second beam splitting device 230 and enters the second detector 220;

The adjusting unit is configured to adjust a focal length of the zoom collimating mirror group 140 and the zoom converging mirror group 240.

It can be understood that the laser emitting device 100 in the optical system provided by the present invention emits a collimated laser beam to the front of the vehicle, and the laser beam is irradiated on an object or a road surface in a certain range in front of the vehicle, and then scattered by the surface of the object or the road surface. The returned laser beam is received by the laser receiving device 200, and spatial information within a specified range in front of the vehicle is obtained by calculating the time from the transmission to the reception of the laser beam.

It can be understood that the emission field of view of the transmitting device is determined by the overall size of the laser light source and the focal length of the zoom collimating lens group 140. The resolution is determined by the distance of the adjacent laser in the laser light source and the zoom collimating lens group 140. The length of the focus. Similarly, the receiving field of view of the receiving device is determined by the overall size of the detector and the focal length of the zooming condenser group 240. The size of the resolution is determined by the spacing of adjacent detecting units within the detector and the focal length of the zooming condenser group 240. . Therefore, the overall size of the laser source and the spacing between adjacent lasers within it are constant. In this case, the size and resolution of the emission field of view can be controlled by controlling the focal length of the zoom collimator group 140. Similarly, in the case where the overall size of the detector and the spacing between the internal detection units are constant, the size and resolution of the received field of view can be controlled by controlling the focal length of the zoom condenser group 240.

Assuming that the focal length of the zoom collimating lens group 140 is the first focal length, the current field size of the first laser light source 110 and the current distance between the lasers inside the first laser light source 110 are near field of view, The focal length of the zoom collimating lens group 140 is the second focal length, the current field size of the first laser light source 110 and the current distance between the lasers inside the first laser light source 110 are the far field of view, and the zoom is concentrated. The focal length of the mirror group 240 is the third focal length, the current overall size of the second detector 220, and the current field of view between the detecting units in the second detector 220 are the near field of view, and the zooming condenser lens group Where the focal length of 240 is the fourth focal length, the current overall size of the second detector 220, and the current field of view between the detection units within the second detector 220 correspond to the far field of view, the present invention provides Description of the optical system:

(1) controlling the first laser light source 110 and the first detector 210 to operate, the second laser light source 120 and the second detector 220 are inoperative, adjusting the focal length of the zoom collimating lens group 140 to the first focal length, and zooming The focal length of the convergence mirror group 240 is adjusted to a third focal length. At this time, the first laser light source 110 emits laser light, which enters the zoom collimating lens group 140 at the reflecting portion of the first beam splitting device 130, and is collimated by the zoom collimating lens group 140 to be projected. The laser emitting device 100 at this time corresponds to the near field of view, so the zoom collimating lens group 140 transmits the laser light to the near field of view. At the same time, the laser receiving device 200 at this time corresponds to the near field of view, so the laser light projected by the zoom collimating lens group 140 is scattered by the zooming condenser group 240 after being scattered on the target surface, and the received laser light is concentrated by the zooming condenser group 240. Thereafter, it is sent to the second beam splitting device 230, and the second beam splitting device 230 projects the reflected portion of the laser light onto the first detector 210, thereby completing laser emission and reception of the near field of view.

That is, when the adjustment unit adjusts the focal length of the zoom collimating lens group 140 to the first focal length and adjusts the focal length of the zoom convergent lens group 240 to the third focal length, the first focal length The zoom collimating lens group 140 is configured to project the received laser light into the near field of view, and the third focal length zoom converging lens group 240 is configured to converge the laser light scattered back in the near field of view and then transmit to the second optical splitting device. 230, can achieve target ranging of near field of view.

(2) controlling the first laser light source 110 and the first detector 210 to be inoperative, the second laser light source 120 and the second detector 220 operating, adjusting the focal length of the zoom collimating lens group 140 to the second focal length, and zooming The focal length of the convergence mirror group 240 is adjusted to a fourth focal length. At this time, the second laser light source 120 emits laser light, which enters the zoom collimating lens group 140 at the transmitting portion of the first beam splitting device 130, and is collimated by the zoom collimating lens group 140 to be projected. The laser emitting device 100 at this time corresponds to the far field, and thus the zoom collimating lens group 140 transmits the laser light to the far field. At the same time, the laser receiving device 200 at this time corresponds to the far field of view, so the laser light projected by the zoom collimating lens group 140 is scattered by the zooming condenser group 240 after being scattered on the target surface, and the received laser light is concentrated by the zooming condenser group 240. Thereafter, it is sent to the second beam splitting device 230, and the second beam splitting device 230 projects the transmitted portion of the laser light onto the second detector 220, thereby completing laser emission and reception of the far field.

That is, when the adjustment unit adjusts the focal length of the zoom collimator group 140 to the second focal length and adjusts the focal length of the zoom convergent lens group 240 to the fourth focal length, the second focal length zoom The collimating mirror group 140 is configured to project the received laser light into the far vision field, and the fourth focal length zoom converging lens group 240 is configured to converge the laser light scattered back in the far field of view and then transmit to the second beam splitting device 230. , the target range of the far field can be achieved.

As can be seen from the above, the optical system provided by the present invention controls the switching of the first laser source 110 and the second laser source 120, the switching of the first detector 210 and the second detector 220, and the zoom collimating lens group 140 and the zooming convergence. By switching the focal length of the mirror group 240, switching between the near field and the far field can be realized, so that the optical system switches to the near field mode when the near field scanning is required, and switches to the far field mode when the far field scanning is required. To meet the requirements of different fields of view and resolution.

In a specific implementation, as shown in FIG. 2, the laser emitting device 100 and the laser receiving device 200 may be disposed on both sides of the central axis 300 of the system. To ensure a match between transmission and reception, no In the near-field scene or the far-field scene, the field of view of the transmitting device is the same as that of the receiving device, and the resolution of the transmitting device is the same as the resolution of the receiving device. In addition, in order to ensure the matching of the transmission and the reception, the light emitting surface of the first laser light source 110 may be matched with the size of the photosensitive receiving surface of the first detector 210, and/or the second laser The light emitting surface of the light source 120 matches the size of the photosensitive receiving surface of the second detector 220.

In a specific implementation, the first laser source 110 and/or the second laser source 120 may include a plurality of semiconductor lasers arranged in an array. Since the emission field of view is determined by the overall size of the laser source and the focal length of the zoom collimator group 140, the resolution of the emitter is determined by the spacing between adjacent lasers within the laser source and the focal length of the zoom collimator group 140. It is decided that, therefore, in order to control the field of view size and the resolution size only according to the focal length of the zoom collimating mirror group 140, the first laser light source 110 and the second laser light source 120 may adopt the same type of laser light source of the same type and arrangement. Of course, in other embodiments, the first laser source 110 and the second laser source 120 may also adopt different laser sources of different types and arrangements. Of course, in other embodiments, the first laser source 110 and/or the second laser source 120 may also employ an array laser to simultaneously realize the emission of multiple lasers using one laser.

In a specific implementation, the first laser source 110 and the second laser source 120 can emit the same laser light, and the response ranges of the first detector 210 and the second detector 220 include a center wavelength corresponding to the laser light emitted by the laser source, and At this time, a neutral beam splitter can be used as the first beam splitting device 130, and the neutral beam splitter can reflect a part of the incident light and transmit a part of the incident light. Similarly, the second beam splitting device 230 can also adopt a neutral beam splitter. The splitting ratio of the neutral beam splitter may be 0.5 to 0.9, for example 0.7, and of course other values.

In a specific implementation, the first laser source 110 and the second laser source 120 can emit lasers of different wavelengths, for example, the first laser source 110 emits a laser having a wavelength of λ ₁ , and the second laser source 120 emits a laser with a wavelength of λ ₂ . At this time, the response range of the first detector 210 matches the center wavelength of the first laser source 110, and the response range of the second detector 220 matches the center wavelength of the second laser source 120. Moreover, a two-color spectroscope can be used as the first spectroscopic device 130, and the two-color spectroscope reflects the laser light of the wavelength λ ₁ emitted by the first laser light source 110, and the wavelength of the second laser light source 120 is λ ₂ . The laser is transmitted. Similarly, the second beam splitting device 230 can also adopt a two-color beam splitter.

In a specific implementation, the second laser source can be disposed on the central axis 301 of the zoom collimator group. Similarly, the second detector can be disposed on the central axis 302 of the zoom convergent lens group.

In a specific implementation, the zoom collimating lens group 140 may include a liquid lens 141, a positive lens 143, and a negative lens 142, wherein the positive lens 143 and the negative lens 142 are conventional lenses whose focal length does not change. The liquid lens 141 can change the curvature of the intermediate interface by applying a voltage between the two liquids before and after, and the diopter of the collimating liquid lens 141 changes accordingly, thereby changing the focal length of the entire zoom collimating lens group 140. In practical applications, the number of liquid lenses and conventional lenses can be selected as needed, and the invention is not limited thereto.

In a specific implementation, the first detector 210 and/or the second detector 220 comprise a plurality of avalanche diodes arranged in an array. Since the size of the received field of view is determined by the overall size of the detector and the focal length of the zoom condenser group 240, the resolution of the receiving device is determined by the spacing between adjacent detector units within the detector and the focal length of the zoom condenser group 240. Therefore, in order to control the field of view size and resolution according to the focal length of the zoom condenser group 240 only, it is possible to use the same type of avalanche diodes of the same type and arrangement. Of course, in other embodiments, the first detector 210 and the second detector 220 may also be avalanche diodes of different types and different arrangements. Of course, in other embodiments, an array of avalanche diodes can be used to simultaneously receive multiple lasers using an array of avalanche diodes.

In a specific implementation, the zoom convergent lens group 240 may include a liquid lens 241, a positive lens 242, and a negative lens 243, wherein the positive lens 242 and the negative lens 243 are conventional lenses whose focal length does not change. The liquid lens 241 can be applied between the two liquids before and after Pressing to change the curvature of the intermediate interface, the diopter of the liquid lens changes accordingly, thereby changing the focal length of the entire zoom condenser group 240. In practical applications, the number of liquid lenses and conventional lenses can be selected as needed, and the invention is not limited thereto.

In a specific implementation, the zoom collimating mirror group 140 and the zoom converging mirror group 240 may adopt the same form of the mirror group, or may adopt different forms of the mirror group.

In a specific implementation, the system provided by the present invention may further include a first filter 251 and a second filter 252, wherein: the first filter 251 is disposed on the first detector 210 and the second splitter Between the devices 230, for suppressing interference of the external stray light to the first detector 210; and/or, the second filter 252 is disposed at the second detector 220 and the second beam splitting device 230 For suppressing interference of the external stray light to the second detector 220.

Here, the stray light is suppressed by the first filter 251 and/or the second filter 252, and the measurement accuracy is improved. In practical applications, in order to ensure the suppression effect of the filter, the center wavelength of the first filter 251 is made to coincide with the center wavelength of the first laser source 110 and the first detector 210, so that the center of the second filter 252 is The wavelength coincides with the center wavelength of the second laser source 120 and the second detector 220.

As shown in FIG. 3, when the first laser light source 110 is in operation, the second laser light source 120 does not operate, and the adjustment unit adjusts the focal length of the zoom collimating lens group 140 to a first focal length f1, and the first laser light source 110 emits The laser light enters the zoom collimating lens group 140 after being reflected by the first beam splitting device 130, and is collimated by the zoom collimating lens group 140 to be emitted. At this time, the size of the first laser light source 110, the spacing between adjacent lasers, and the focal length of the zoom collimating mirror group 140 determine the near-emissive field of view and the resolution in the vertical direction. As shown in FIG. 4, when the first laser light source 110 is not in operation, the second laser light source 120 operates, and the adjustment unit adjusts the focal length of the zoom collimating lens group 140 to a second focal length f2, and the second laser light source 120 emits The laser light is reflected by the first beam splitting device 130 and enters the zoom collimating mirror group 140, and is collimated by the zoom collimating mirror group 140 to be emitted. At this time, the size of the second laser light source 120, the spacing between adjacent lasers, and the focal length of the zoom collimating mirror group 140 determine the far-emitting field of view and the resolution in the vertical direction. For To satisfy the far and near emission fields of view and the corresponding resolution, the focal length f1 of the zoom collimating mirror group 140 is smaller than the focal length f2 of the zoom collimating mirror group 140.

As shown in FIG. 5, when the first detector 210 is in operation and the second detector 220 is not in operation, the adjustment unit adjusts the focal length of the zoom convergence lens group 240 to a third focal length f3, corresponding to the first detector 210. The laser light reflected from the receiving field of view is concentrated by the zooming condenser group 240 and then reflected by the second beam splitting device 230 to enter the first detector 210. The overall size of the first detector 210 and the first detector 210 are internally detected. The spacing between the cells and the focal length of the zoom convergent lens set 240 determine the near-receiving field of view at this time and the resolution in the vertical direction. As shown in FIG. 6, when the first detector 210 is inactive and the second detector 220 is in operation, the adjustment unit adjusts the focal length of the zooming condenser group 240 to a fourth focal length f4, in the second detector 220. The laser light reflected from the corresponding receiving field of view is concentrated by the zooming condenser group 240 and then transmitted through the second beam splitting device 230 to enter the second detector 220. The overall size of the second detector 220 and the interior of the second detector 220 are The spacing between the detection units and the focal length of the zoom condenser group 240 determine the resolution of the field of view and the vertical direction at this time. In order to satisfy the near and far receiving fields of view and the corresponding resolution, the focal length f3 of the zooming condenser group 240 is smaller than the focal length f4 of the zooming condenser group 240.

It can also be seen in FIG. 5 that when the laser radar observes the target in the near field of view, both the laser emitting device 100 and the laser receiving device 200 are in the near field mode, at this time, the liquid lens in the zoom collimating lens group 140 and The diopter of the liquid lens in the zoom condenser group 240 is Q1 and Q3, respectively, and the focal lengths of the zoom collimator group 140 and the zoom condenser group 240 are f1 and f3, respectively, and the first laser source 110 emits N lasers. A splitting device 130 is then collimated by the zoom collimating mirror group 140, and the scanning field of view of the N laser beam is α, and the scanning resolution between the adjacent two channels in the vertical direction is α/(N- 1). In the near field mode, the laser field receiving device 200 and the laser receiving device 200 respectively have the same field of view and resolution, and the laser beam reflected by the target in the near field is received by the zooming condenser group 240 and concentrated by the second beam splitting device 230. The reflection is finally received by the first detector 210.

It can also be seen in Figure 6 that when the lidar observes the target in the far field, Both the laser emitting device 100 and the laser receiving device 200 are in a far field mode, in which the liquid lens in the zoom collimating lens group 140 and the liquid lens in the zoom convergent lens group 240 have diopter Q2 and Q4, respectively, and the zoom collimating lens group The focal lengths of the 140 and zoom convergence mirror groups 240 are f2 and f4, respectively, and the second laser light source 120 emits N lasers, passes through the second beam splitting device 230, and is then collimated by the zoom collimating mirror group 140, and then exits. The scanning field of view of the laser beam is β, and the scanning resolution between adjacent two channels in the vertical direction is β/(N-1). In the near field mode, the laser field receiving device 200 and the laser receiving device 200 respectively have the same field of view and resolution, and the laser beam reflected by the target in the far field is received by the zooming condenser group 240 and concentrated by the second beam splitting device 230. The reflection is finally received by the second detector 220.

In the description of the invention, numerous specific details are illustrated. However, it is understood that the embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques are not shown in detail so as not to obscure the understanding of the description.

The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to be limiting; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art will understand that The technical solutions are described as being modified, or equivalent to some of the technical features, and the modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Industrial applicability

The laser radar optical system provided by the present invention controls the switching between the first laser source and the second laser source, the switching of the first detector and the second detector, and the focal length conversion of the zoom collimating mirror group and the zoom converging mirror group, It is possible to switch between the near field of view and the far field of view, so that the optical system switches to the near field mode when it needs to perform near field of view scanning, and switches to the far field mode when it needs to perform far field scanning to meet different fields of view and resolution. The rate requirement has industrial applicability.

Claims

A laser radar optical system, comprising: a laser emitting device, a laser receiving device and an adjusting unit, wherein:

The laser emitting device includes a first laser light source, a second laser light source, a first beam splitting device, and a zoom collimating lens set, wherein the first beam splitting device is disposed at a position suitable for causing the laser light emitted by the first laser source to be After being reflected on the first beam splitting device, entering the zoom collimating mirror group and causing the laser light emitted by the second laser source to be transmitted on the first beam splitting device to enter the zoom collimating mirror group, the zooming standard The straight lens group is configured to collimate the received laser light and project it into a field of view corresponding to a current focal length of the zoom collimating lens group;

The laser receiving device includes a first detector, a second detector, a second beam splitting device, and a zooming convergence lens group, the zooming condenser lens group is configured to view a field of view corresponding to a current focal length of the zooming convergence lens group The laser light scattered back in the range is concentrated, and the second light splitting device is disposed at a position suitable for the laser light concentrated by the zooming convergence lens group to be reflected on the second light splitting device to enter the first detector and The laser concentrated by the zooming convergence lens group is transmitted on the second beam splitting device and then enters the second detector;

The adjusting unit is configured to adjust a focal length of the zoom collimating mirror group and the zoom converging mirror group.
The system of claim 1 wherein said laser receiving device further comprises:

a first filter disposed between the first detector and the second beam splitting device for suppressing interference of external stray light to the first detector; and/or

And a second filter disposed between the second detector and the second beam splitting device for suppressing interference of external stray light to the second detector.
The system of claim 1 wherein said first laser and said second laser are adapted to emit laser light of the same wavelength, said first beam splitting device and said second beam splitting device being neutral beam splitters .
The system according to claim 3, wherein said central beam splitter has a split ratio of 0.5 to 0.9.
The system of claim 1 wherein said first laser and said second laser are adapted to emit laser light of different wavelengths, said first beam splitting means and said second beam splitting means being a two-color beam splitter.
The system of claim 1 wherein said zoom collimating mirror set and/or said zoom converging mirror set comprises a liquid lens, a positive lens and a negative lens.
The system of claim 1 wherein said first laser source and/or said second laser source comprises a plurality of semiconductor lasers or an array of lasers arranged in an array.
The system of claim 1 wherein said first detector and/or said second detector comprises a plurality of avalanche diodes or an array of avalanche diodes arranged in an array.
The system of claim 1 wherein the light emitting surface of the first laser source matches the size of the photosensitive receiving surface of the first detector and/or the illumination of the second laser source The face matches the size of the photosensitive receiving face of the second detector.
The system of claim 1 wherein said laser emitting device and said laser receiving device are distributed on either side of a central axis of said optical system.