Airborne optical scanning distance measuring device and laser radar

Abstract

The utility model provides an airborne optical scanning distance measuring device and a laser radar. The airborne optical scanning distance measuring device comprises a collimation optical assembly; a receiving optical component; a planar oscillating mirror; and rotating the mirror drum. Through a multi-line laser scanning mode, compared with a traditional single-line laser scanning technology, more point cloud data can be collected in the same scanning period, a finer scanning grid can be generated, three-dimensional space information with a higher resolution ratio can be provided, the spatial morphology of a target area can be presented in a finer and more abundant mode, and the target area can be displayed more accurately. Spatial perception and obstacle recognition capabilities of the equipment in a complex scene are remarkably improved, high-speed horizontal scanning of the rotary reflecting mirror drum and low-speed vertical scanning of the plane oscillating mirror are combined, large-range efficient coverage is realized, and in addition, through paraxial design and separation of transmitting and receiving light paths, the space sensing and obstacle recognition capabilities of the equipment in a complex scene are greatly improved. And in combination with the layout that the rotary reflecting mirror drum is arranged below the multi-path light beam emitting assembly, compact arrangement in the device is realized, the overall size is reduced, and the device is suitable for space limitation of airborne application.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of laser ranging, especially to an airborne optical scanning ranging device and laser radar. BACKGROUND

[0002] Laser radar is the main sensor for responding to obstacle identification and detection in poor visual environment, and is widely used in automatic driving, unmanned aerial vehicle navigation and other fields requiring high-precision environmental perception. By generating a real-time three-dimensional environmental model, static and dynamic obstacles can be identified, and basic obstacle avoidance functions can be provided. The traditional single-line laser radar can only collect data along one scanning line at a time during scanning, resulting in low data acquisition density and sparse point cloud images, which is insufficient in scenarios requiring high-resolution perception. At the same time, the scanning range of single-line laser radar is limited, making it difficult to fully cover the target area, and the real-time perception ability of the global environment in dynamic environments is weak. In addition, in low-visibility environments such as foggy and rainy days, the detection performance may be significantly affected, reducing the reliability of obstacle identification, and therefore an airborne optical scanning ranging device and laser radar are proposed to solve the above problems. SUMMARY

[0003] The main purpose of the utility model is to provide an airborne optical scanning ranging device and laser radar, which can generate high-density three-dimensional environmental point cloud images in a shorter time through multi-beam scanning ranging, and has reliable obstacle avoidance performance in low-visibility conditions.

[0004] To solve the above technical problems, the utility model adopts the following technical scheme: an airborne optical scanning ranging device, comprising:

[0005] A collimating optical assembly includes a multi-beam emitting assembly and an outgoing mirror arranged in sequence, the multi-beam emitting assembly is used for emitting multi-beam, and the outgoing mirror is inclined to change the outgoing angle;

[0006] A receiving optical assembly includes a light receiving assembly and a light reflecting mirror arranged in sequence, the light reflecting mirror is inclined to reflect light to the light receiving assembly, wherein the light reflecting mirror is provided with a through hole, the outgoing mirror is located directly above the through hole, and the multi-beam can pass through the light reflecting mirror through the through hole;

[0007] A plane swing mirror is arranged below the light reflecting mirror and the through hole, and is used for adjusting the vertical scanning direction;

[0008] A rotating mirror drum is arranged opposite to the reflecting surface of the plane swing mirror, and is used for adjusting the horizontal scanning direction.

[0009] In the preferred scheme, the multi-beam emitting assembly includes a fiber array and a collimating mirror arranged in sequence.

[0010] In the preferred embodiment, the light receiving assembly comprises a detector array, a filter and a condenser arranged in sequence.

[0011] In the preferred embodiment, the collimating optical assembly and the receiving optical assembly are arranged perpendicularly with the axis of the through hole as the reference.

[0012] In the preferred embodiment, the rotating mirror drum is arranged below the multi-beam emitting assembly.

[0013] In the preferred embodiment, the light emitting mirror and the light receiving mirror are both arranged at an angle of 45 degrees.

[0014] In the preferred embodiment, the control and acquisition module comprises an AD conversion and data processing board, a pulsed laser and its circuit driver, and an analog detection and amplification circuit connected in sequence, wherein the pulsed laser and its circuit driver are used to generate laser light and emit the laser light through the collimating optical assembly, the analog detection and amplification circuit is used to convert the light signal received by the receiving optical assembly into an electric signal, amplify the pulsed signal, and transmit the pulsed signal to the AD conversion and data processing board, and the AD conversion and data processing board is used to receive power supply and radar control signals, and convert the received pulsed signal into a digital signal output.

[0015] In another technical solution, an airborne laser radar is provided, comprising the airborne optical scanning ranging device.

[0016] The utility model provides a kind of airborne optical scanning ranging device and laser radar, by multi-line laser scanning mode, compared with traditional single-line laser scanning technology, it can collect more point cloud data in the same scanning period, generate more fine scanning grid, provide higher resolution three-dimensional space information, can more delicate, richly present the spatial appearance of target area, make the spatial perception and obstacle identification ability of equipment in complex scene significantly improve, combine the high-speed horizontal scanning of rotating mirror drum and the low-speed vertical scanning of plane swing mirror, realize large-scale efficient coverage, in addition, by paraxial design, emission and receiving optical path are separated, and combine the layout of rotating mirror drum arranged below multi-beam emitting assembly, effectively reduce the use of optical path intersection and redundant optical element, realize the compact arrangement inside device, reduce overall size, suitable for the space limit of airborne application. BRIEF DESCRIPTION OF DRAWINGS

[0017] The utility model will be further described below in connection with drawings and examples:

[0018] Fig. 1 It is the principle structure diagram of the utility model;

[0019] Fig. 2 It is the module block diagram of the utility model;

[0020] In the figure: 1. Fiber optic array; 2. Collimating lens; 3. Detector array; 4. Filter; 5. Condenser lens; 6. Light-emitting mirror; 7. Light-returning mirror; 8. Through hole; 9. Planar oscillating mirror; 10. Rotating mirror drum. Detailed Implementation

[0021] like Figs. 1-2 As shown, an airborne optical scanning rangefinder device comprises a collimating optical component, a receiving optical component, a two-dimensional scanning structure, and a control and acquisition module. The two-dimensional scanning structure includes a planar pendulum mirror 9 and a rotating reflector drum 10.

[0022] The collimating optical component includes a multi-beam emitting component and a light-emitting reflector 6 arranged sequentially. The multi-beam emitting component is used to emit multiple beams, and the light-emitting reflector 6 is tilted to change the light emission angle. Specifically, the multi-beam emitting component includes a fiber array 1 and a collimating mirror 2 arranged sequentially. The laser forms multiple beams through the fiber array 1, which are then converged and collimated by the collimating mirror 2 to form a collimated beam with a certain divergence angle. The light-emitting reflector 6 changes the angle of the emitted light so that the multiple beams can be directed toward the two-dimensional scanning structure.

[0023] It should be noted that the number of lasers can be the same as the number of optical fibers in fiber array 1, and the array can be made using the output optical fiber of each laser. Alternatively, a single laser can be made into an array by using an optical fiber beam splitter. The choice can be made freely according to the required operating distance.

[0024] The receiving optical component includes a backlight receiving component and a backlight reflecting mirror 7 arranged sequentially. The backlight reflecting mirror 7 is tilted to reflect the backlight into the backlight receiving component. The backlight reflecting mirror 7 is provided with a through hole 8, and the light emitting mirror 6 is located directly above the through hole 8. Multiple light beams can pass through the through hole 8 and the backlight reflecting mirror 7. This design allows the paths of the emitted light beam and the echo signal to overlap and separate reasonably. By adopting a compact backlight path design, the echo signal directly enters the backlight receiving component after being reflected by the backlight reflecting mirror 7. This layout not only reduces the optical path length but also effectively saves internal space of the device.

[0025] The backlight receiving component includes a detector array 3, a filter 4, and a condenser lens 5 arranged in sequence. In use, the condenser lens 5 focuses the echo signals from different fields of view onto the photosensitive surface of the detector array 3. The filter 4 performs spectral filtering on the echo signals to eliminate stray light interference and enhance signal quality. The detector array 3 converts the optical signal into an electrical signal.

[0026] Meanwhile, the design of the collimating optical assembly and the receiving optical assembly makes the transmitting path and the receiving path share part of the optical path, reduces the overall size of the device through the off-axis design, reduces the interference of stray light, and synchronizes the scanning and collecting processes. Specifically, the transmitting path and the receiving path are separated in space but share the position of the light returning mirror 7, and part of the optical path is overlapped in space through the through hole. This arrangement reduces the reuse of optical elements, optimizes the internal structure layout of the device, and reduces the overall size. In addition, after the transmitting path and the receiving path are separated, non-target light signals from the light source to the receiver, such as scattering or surface reflection of the light source itself, will not directly enter the receiving optical assembly, thereby effectively reducing the interference of stray light on signal quality and improving the signal-to-noise ratio.

[0027] The plane swing mirror 9 is arranged below the light returning mirror 7 and the through hole 8, and is used to adjust the vertical scanning direction. The rotating mirror drum 10 is arranged opposite to the reflecting surface of the plane swing mirror 9, and is used to adjust the horizontal scanning direction.

[0028] In use, the rotating mirror drum 10 realizes horizontal fast scanning through high-speed rotation, and the swing mirror realizes vertical slow scanning through low-speed back-and-forth swinging. That is, one frame of point cloud is obtained every half cycle of the swing mirror. In addition, the horizontal scanning field angle is 720 / N, and N is the number of mirror drum surfaces. The vertical scanning field angle is 2θ, and θ is the maximum angular amplitude of the swing mirror.

[0029] It should be noted that the plane swing mirror 9 and the rotating mirror drum 10 are commercially available products, and thus will not be described in detail here.

[0030] The control and collection module includes an AD conversion and data processing board, a pulsed laser and its circuit driving, and an analog detection and amplification circuit connected in sequence. The pulsed laser and its circuit driving are used to generate laser and emit it through the collimating optical assembly. The analog detection and amplification circuit is used to convert the light signal received by the receiving optical assembly into an electrical signal, amplify the pulsed signal, and transmit it to the AD conversion and data processing board. The AD conversion and data processing board is used to receive power supply and radar control signals, convert the received pulsed signal into a digital signal output, and calculate the distance of the target point by capturing the time difference of the laser flight.

[0031] In the preferred scheme, the collimating optical assembly and the receiving optical assembly are arranged vertically with the axis of the through hole 8 as the reference, which simplifies the optical path design and, in combination with the inclination design and size difference of the light returning mirror 7 and the light emitting mirror 6, can maximize the reduction of the height difference between the collimating optical assembly and the receiving optical assembly.

[0032] In the preferred scheme, the rotating mirror drum 10 is arranged below the multi-path light beam emitting assembly, which makes the internal structure of the device more compact.

[0033] In the preferred scheme, the light-out mirror 6 and the light-back mirror 7 are both arranged at an angle of 45 degrees, which ensures efficient alignment of the light path.

[0034] It should be noted that the optical system of the device adopts an aspheric lens design to reduce off-axis aberration and improve optical performance, and further reduces the complexity and volume of the light path, improves the portability and adaptability of the device, and the device is installed in the corresponding shell through the above position relationship, which is a common technical means in the art, and therefore will not be described in detail here.

[0035] In use, the laser generates multiple light beams, which are transmitted to the collimating mirror 2 through the optical fiber array 1 to form parallel light beams with a certain included angle. The light beams are reflected obliquely by the light-out mirror 6, pass through the through hole 8 of the light-back mirror 7, and are incident into the two-dimensional scanning structure; the light beams are subjected to high-speed horizontal scanning by the rotating mirror drum 10 in the two-dimensional scanning structure, and slow-speed vertical scanning is realized by the swinging of the plane swing mirror 9; the scanned light beams irradiate the target object surface, and the echo signals are formed by the diffuse reflection of the target object surface, return through the same light path, and are reflected into the receiving optical assembly by the light-back mirror 7; the condenser lens 5 in the receiving optical assembly focuses the echo signals of different fields of view onto the light-sensitive surface of the detector array 3; the filter 4 performs spectral filtering on the echo signals to eliminate stray light interference and enhance signal quality; the detector array 3 converts the optical signals into electrical signals and transmits them to the analog detection and amplification circuit for amplification; the amplified electrical signals are converted into digital signals by the AD conversion and data processing board, and point cloud data of the target is generated; the processed point cloud data can be transmitted to external equipment in real time for generating a three-dimensional environment model.

[0036] The device can be used in an airborne environment, can realize three-dimensional target recognition of obstacles and landing field areas in the flight route, realize high-precision recognition of obstacle targets such as high-voltage lines, towers, and buildings, and can also be installed on both sides of the channel or the gate for fixed scanning, detect the contours and distances of ships within the range, and be used for bridge anti-collision and heading deviation warning.

[0037] The embodiment also provides an airborne laser radar comprising the airborne optical scanning ranging device, and thus the technical advantages and effects achieved by the airborne optical scanning ranging device also include the technical advantages and effects achieved by the scanning device, which will not be described here.

[0038] The above embodiment is only a preferred technical solution of the present application, and should not be regarded as a limitation of the present application. The protection scope of the present application should be based on the technical solution claimed in the claims, including equivalent replacement schemes of the technical features claimed in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present application.

Claims

1. An airborne optical scanning ranging device characterized by, It comprises: a collimating optical assembly, which comprises a multi-beam emitting assembly and a light-emitting mirror (6) arranged in sequence, the multi-beam emitting assembly is used for emitting multi-beam, and the light-emitting mirror (6) is arranged obliquely and used for changing the light-emitting angle; a receiving optical assembly, which comprises a light-receiving assembly and a light-receiving mirror (7) arranged in sequence, the light-receiving mirror (7) is arranged obliquely and used for reflecting light back to the light-receiving assembly, wherein a through hole (8) is arranged on the light-receiving mirror (7), the light-emitting mirror (6) is located directly above the through hole (8), and the multi-beam can pass through the light-receiving mirror (7) through the through hole (8); a plane swing mirror (9) arranged below the light-receiving mirror (7) and the through hole (8) and used for adjusting the vertical scanning direction; a rotating mirror drum (10) arranged opposite to the reflecting surface of the plane swing mirror (9) and used for adjusting the horizontal scanning direction.

2. An airborne optical scanning ranging device according to claim 1, wherein: The multi-beam emitting assembly comprises an optical fiber array (1) and a collimating mirror (2) arranged in sequence.

3. An airborne optical scanning ranging device according to claim 2, wherein: The light-receiving assembly comprises a detector array (3), a filter (4) and a condenser (5) arranged in sequence.

4. The airborne optical scanning ranging device according to any one of claims 1-3, characterized in that: The collimating optical assembly and the receiving optical assembly are arranged vertically with the axis of the through hole (8) as the reference.

5. An airborne optical scanning ranging device according to claim 4, wherein: The rotating mirror drum (10) is arranged below the multi-beam emitting assembly.

6. An airborne optical scanning ranging device according to claim 4, wherein: The light-emitting mirror (6) and the light-receiving mirror (7) are both arranged obliquely at an angle of 45 degrees.

7. The airborne optical scanning LIDAR device of claim 1, wherein: It also comprises a control and acquisition module, which comprises an AD conversion and data processing board, a pulsed laser and its circuit driving and an analog detection and amplification circuit connected in sequence, wherein the pulsed laser and its circuit driving are used for generating laser and emitting through the collimating optical assembly, the analog detection and amplification circuit is used for converting the optical signal received by the receiving optical assembly into an electrical signal, amplifying and processing the pulsed signal, and transmitting to the AD conversion and data processing board, the AD conversion and data processing board is used for receiving power supply and radar control signal, and converting the received pulsed signal into digital signal output.

8. A lidar, characterized by, It comprises an airborne optical scanning ranging device according to any one of claims 1-7.

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