A false color laser radar system

Abstract

The present invention provides a false color laser radar system, comprising a broadband optical transceiver, a color separation prism combination, a data acquisition system and a control system connected in sequence; a control unit is used to control the broadband optical transceiver to transmit a radar beam to illuminate a target object; the broadband optical transceiver transmits the echo optical signal reflected by the target object to the color separation prism combination; the color separation prism combination divides the echo optical signal into multiple spectral channels according to wavelength; the control unit also processes and synthesizes the light beams of multiple spectral channels collected by the data acquisition unit to obtain false color point cloud data. The present invention uses a color separation prism combination to divide the echo optical signal into multiple spectral channels according to wavelength, and has a simple structure. At the same time, compared with a high-spectral spectroscopic method with a channel width of 10nm, the color separation filter of the present invention selects a channel width of not less than 100nm, can receive higher light pulse energy in the channel, and has a technical advantage of long-distance detection.

Description

Technical Field

[0001] The present invention relates to the technical field of laser radar, and in particular to a false color laser radar system. Background Art

[0002] As an active optoelectronic device used to obtain the spatial orientation information of the target and the observer, LiDAR has the advantages of narrow beam, good directivity, high spatial resolution, anti-interference, and all-day operation. It is currently widely used in terrain surveying and mapping, agriculture, forestry, three-dimensional modeling, unmanned driving and other fields. Among them, the ranging LiDAR obtains the target distance by emitting a single-wavelength laser pulse to the target, measuring the flight time information of the pulse between the radar and the target, and providing scanning angle information according to the field of view of the radar light emission and receiving system, calculating the three-dimensional space point cloud data distribution of the target in the spherical coordinate system, and combining the grayscale value provided by the echo signal intensity to analyze the characteristics of the target object. However, the target feature extraction capability of traditional ranging LiDAR is closely related to the density of the three-dimensional space point cloud data. For large objects, it will bring too much point cloud data, which requires post-processing algorithms to remove redundancy. For occluded objects or small objects, there is an incomplete detection problem, which makes it impossible to effectively identify the target.

[0003] In order to improve the detection and recognition capabilities of laser radar for targets, an effective solution is to fuse the spatial point cloud data with the target color or spectral information, and use the target color information or spectral information to improve the target classification and judgment capabilities. The patent with application number CN201310214136.8 discloses an integrated three-dimensional color laser radar data point cloud generation method and device, but its monocular color camera is a passive optoelectronic device, which depends on daytime sunlight and has the problem of not being able to work all day. The patent with application number CN201911165990.3 discloses a UAV power transmission line geological disaster warning system that combines laser radar and hyperspectral imager, but its hyperspectral imager is a passive imaging device and also has the problem of not being able to work all day. Selecting high-energy supercontinuum laser as a coherent illumination light source can provide wide-spectrum long-distance illumination with a spectrum covering visible light to near-infrared bands, and using it to replace the single-wavelength laser pulse of traditional laser radar, and then combined with a spectral detection device, it can actively obtain target azimuth information and spectral information at the same time. The patent with application number CN201810034753.2 discloses a hyperspectral lidar system with high spectral resolution and distance resolution. It uses fiber dispersion to separate the spectral frequency of supercontinuum laser pulses in time, and uses a spectral measurement unit to obtain the spectral characteristic data of the target visible light and near-infrared bands respectively. However, its continuous splitting process will lead to low energy in a single spectral channel, and the radar spectrum detection working distance cannot be guaranteed. The patent with application number CN201811598297.0 discloses a hyperspectral three-dimensional structure radar system based on near-infrared full waveform ranging. It obtains spectral data by splitting supercontinuum laser pulses into multiple visible light to near-infrared spectral channels, but it also has the problem of low energy in a single spectral channel. The patent with application number CN202010570326.3 discloses an airborne supercontinuum laser hyperspectral lidar system. The width of a single spectral channel is only 10nm. There is a problem of low energy in a single spectral channel and limiting the radar spectrum detection working distance. At the same time, it also has the problem of strong interference from solar radiation in the visible light band. The patent with application number CN 201811598297.0 discloses a hyperspectral three-dimensional lidar system based on near-infrared full-waveform ranging. The ranging and spectral detection contents of this patent are separated and the way of utilizing spectral information is different from that of the present invention. In addition, the related calculation method is complicated and the recognition effect is poor.

[0004] It can be seen that since the working distance of the lidar is closely related to the energy of the supercontinuum laser pulse, the existing invention that combines spectral detection technology with ranging lidar technology still has obvious technical defects. Although the high resolution of the spectral channel (spectral bandwidth ~ 10nm) can provide a fine spectrum, the energy of the light pulse in a single channel is too low, which greatly reduces the working distance of the radar and makes it difficult to have practical applications. Summary of the invention

[0005] In order to solve the technical problem that there are still technical defects in combining the spectrum detection technology with the ranging laser radar technology in the prior art, the present invention provides a false color laser radar system, including: a broadband light transceiver, a color separation prism combination, a data acquisition system and a control system connected in sequence, wherein the control unit is also connected to the broadband light transceiver;

[0006] The control unit is used to control the broadband optical transceiver to emit a laser radar beam to illuminate the target object;

[0007] The broadband optical transceiver transmits the received echo optical signal reflected by the target object to the dichroic prism assembly;

[0008] The color separation prism combination divides the echo light signal into multiple spectral channels according to wavelength;

[0009] The control unit is also used to process and synthesize the light beams of multiple spectral channels collected by the data collection unit to obtain false color point cloud data.

[0010] Preferably, the broadband optical transceiver comprises: a broadband optical transmitting and receiving system, a beam collimator and a high-energy supercontinuum laser;

[0011] The wide-spectrum light transmitting and receiving system comprises: a wide-spectrum light transmitting system and a wide-spectrum light receiving system which are quasi-coaxially arranged.

[0012] Preferably, the broadband light emitting system comprises: a beam expander, a first plane reflector arranged at 45° to the beam expander, and a second plane reflector arranged parallel to the first plane reflector.

[0013] Preferably, the high-energy supercontinuum laser is directly generated by a fiber amplifier, emitting fundamental mode supercontinuum laser pulses with a repetition frequency of 100kHz, a pulse width of 10ns, a pulse energy of 10μJ, a spectral range of 1000-2000nm, and a beam waist radius of 5μm, concentrated in the near-infrared 1-2μm, or 2-2.5μm.

[0014] Preferably, when the spectrum emitted by the high-energy supercontinuum laser is in the range of 1-2 μm, the optical fiber amplifier is a trivalent ytterbium-doped silica optical fiber amplifier with a double-cladding structure;

[0015] When the spectrum range is 2-2.5 μm, the optical fiber amplifier is a trivalent thulium ion-doped quartz optical fiber amplifier with a double-cladding structure.

[0016] Preferably, the broadband light receiving system comprises a reflector, a main reflector, a pinhole aperture and a short focal length collimating lens arranged in sequence;

[0017] The reflector is a convex mirror, and the convex surface of the reflector faces the main reflector;

[0018] The mirror surface of the main reflector has a certain curvature, and its concave surface faces the reflector;

[0019] The main reflector is provided with a light-transmitting hole;

[0020] The midpoint of the reflector, the light-transmitting hole of the main reflector, the light-transmitting hole of the pinhole diaphragm and the midpoint of the short-focal-length collimating lens are located on the same straight line.

[0021] Preferably, the color separation prism combination includes: an even number of prisms with the same structure.

[0022] Preferably, the prism is a right-angle prism;

[0023] The hypotenuses of every two right-angle prisms are pasted together to form a square, and the pasting point is an oblique boundary surface; multiple squares are pasted in pairs to form a non-linear structure.

[0024] Preferably, different optical films are plated on the light-emitting surface and the hypotenuse interface of the prism.

[0025] Preferably, there are six prisms, forming three squares;

[0026] When the first square and the second square are pasted together, their hypotenuse intersection surfaces are arranged in parallel;

[0027] The third square is pasted to the second square, and the vertices of the hypotenuse intersection interface thereof intersect to form a right angle; the surface (14) of the second square is arranged perpendicular to the echo optical signal transmitted by the wide-spectrum optical transmitting and receiving system.

[0028] Preferably, the optical film includes: a long-wave pass filter film, a two-color spectroscopic film and a short-wave pass filter film;

[0029] The surface (13) of the third square is coated with a long-wave pass filter film under 0° incidence condition;

[0030] The hypotenuse interface (9) of the second square, the hypotenuse interface (10) of the first square, and the surface (11) of the first square are respectively coated with two-color splitting films of different wavelengths of split light under an incident condition of 45 degrees;

[0031] The hypotenuse interface (12) of the third square is plated with a short-wave pass filter film under 0° incident conditions.

[0032] Preferably, there are four light emitting surfaces.

[0033] Preferably, the data acquisition system comprises: a four-channel data acquisition card and four channel units;

[0034] Each of the channel units comprises a photodetector, a signal amplifier and an analog-to-digital converter connected in sequence;

[0035] The four-channel data acquisition card is used to receive light intensity information of each channel.

[0036] Preferably, the control system comprises: a control computer, a time interval measuring unit, a scanning mechanism, a data processing unit and a data storage unit;

[0037] The time interval measuring unit is used to: compare the time delay between the trigger signal provided by the control computer and the echo light signal;

[0038] The scanning mechanism is used to: record the azimuth information of a single laser radar beam;

[0039] The data processing unit is used to: perform calculations based on the time delay of the trigger signal and the echo light signal obtained by the time interval measurement unit, the azimuth information determined by the scanning mechanism, and the four-channel light intensity information obtained by the four-channel data acquisition card to obtain single-point radar data;

[0040] The data storage unit is used to store the single-point radar data calculated by the data processing unit.

[0041] Preferably, the data processing unit is also used to integrate a large amount of single-point radar data stored in the data storage unit to form multi-channel radar point cloud data; and obtain a false color radar point cloud map with multiple colors corresponding to the target object based on the multi-channel radar point cloud data combined with a false color synthesis method.

[0042] Preferably, the radar point data includes: radar point spatial coordinates and multi-channel light intensity information corresponding to the target object.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] 1. The present invention provides a false color laser radar system, comprising a broadband optical transceiver, a color separation prism combination, a data acquisition system and a control system connected in sequence, wherein the control unit is also connected to the broadband optical transceiver; the control unit is used to control the broadband optical transceiver to emit a laser radar beam to illuminate the target object; the broadband optical transceiver transmits the received echo light signal reflected by the target object to the color separation prism combination; the color separation prism combination divides the echo light signal into multiple spectral channels according to wavelength; the control unit is also used to process and synthesize the light beams of multiple spectral channels collected by the data acquisition unit to obtain false color point cloud data. The present invention utilizes a color separation prism combination to divide the echo light signal into multiple spectral channels according to wavelength, and has the characteristics of simple structure. At the same time, compared with the high-spectral spectroscopic method with a channel width of 10nm, the color separation filter of the present invention selects a channel width of not less than 100nm, which can provide higher light pulse energy in the channel and has the technical advantage of long-distance detection distance;

[0045] 2. At the same time, compared with the point cloud data of monochrome laser radar, the technical means provided by the present invention forms false color laser radar data based on multiple spectral channels, which reflects the color information of the target object and makes the information richer;

[0046] 3. The technical means provided by the present invention can provide two-color synthesis, three-color synthesis and four-color synthesis of the target in the near-infrared band, and support the identification of the target category by using the color difference between channels; the calculation method is simple and flexible;

[0047] 4. The present invention uses a high-energy supercontinuum laser as the illumination light source, which is directly generated by a near-infrared fiber amplifier solution to obtain a supercontinuum laser pulse energy of more than 10 μJ; the spectral energy of the present invention is more concentrated in the characteristic spectrum of the target, and the energy utilization rate is higher;

[0048] 5 The present invention uses a high-energy supercontinuum laser whose spectral range is larger than the sum of the ranges of the four spectral channels finally filtered out by the color separation prism combination. The selection of a single channel width will maximize the utilization of the total energy of the supercontinuum laser and have a higher detection efficiency;

[0049] 6. The false color radar point cloud data provided by the present invention can be used to identify targets using target color features, especially in the case of single-point detection or sparse detection, the target category can also be identified based on the target's rich color information. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is a structural schematic diagram of a false color laser radar system of the present invention;

[0051] Figure 2 It is a general principle block diagram of the present invention;

[0052] Figure 3 is a comparison diagram of the average radiation flux of supercontinuum laser and sunlight used in an embodiment of the present invention;

[0053] Figure 4 is a schematic diagram of a wide-spectrum optical transmission and reception system in an embodiment of the present invention;

[0054] Figure 5 is a schematic diagram of the structure of a color separation prism group in an embodiment of the present invention;

[0055] Figure 6 Schematic diagram of the reflection spectrum of the two-color beam splitting film at the interface of the dichroic prism group in the embodiment of the present invention;

[0056] Figure 7 Schematic diagram of the transmittance spectrum of the filter film on the surface of the dichroic prism group in the embodiment of the present invention;

[0057] Figure 8 Schematic diagram of the shape of four-channel spectral channels in an embodiment of the present invention. DETAILED DESCRIPTION

[0058] In order to better understand the present invention, the content of the present invention is further described below in conjunction with the accompanying drawings and examples.

[0059] Embodiment 1:

[0060] The purpose of the present invention is to provide a false color laser radar system, which adopts a high-energy supercontinuum laser with spectral energy in the near-infrared band as an illumination light source, and divides the echo light signal into four ultra-wideband (channel width 100-200nm) optical channels through a color separation prism combination, so as to realize four-channel false color image information of the target in the non-visible light band, and has the characteristics of false color synthesis, long distance, all-day, active operation, etc. The rich color information provided by the false color synthesis can support high-precision resolution and recognition of target categories, and is easy to be widely promoted and used in many fields such as terrain surveying and mapping, agriculture, forestry, three-dimensional modeling, and unmanned driving.

[0061] The technical solution adopted by the present invention is as follows Figure 1 As shown. It is specifically composed of a control system, a wide-spectrum optical transceiver, a color separation prism combination, and a data acquisition system;

[0062] Furthermore, the broadband optical transceiver comprises a broadband optical transmitting and receiving system, a beam collimator and a high-energy supercontinuum laser; the broadband optical transmitting and receiving system comprises: a broadband optical transmitting system and a broadband optical receiving system arranged quasi-coaxially; the broadband optical transmitting system comprises: a beam expander and two plane reflectors;

[0063] Further, the data acquisition system includes: a four-channel data acquisition card and a channel unit;

[0064] Further, the channel unit includes: a first photodetector, a first electrical signal amplifier, a first analog-to-digital converter, a second photodetector, a second electrical signal amplifier, a second analog-to-digital converter, a third photodetector, a third electrical signal amplifier, a third analog-to-digital converter, a fourth photodetector, a fourth electrical signal amplifier, and a fourth analog-to-digital converter;

[0065] Furthermore, the control system includes: a control computer, a time interval measuring unit, a data processing unit, a data storage unit and a scanning mechanism.

[0066] The control computer is composed of a field programmable gate array or a digital signal processor, and is used to generate a trigger signal to start the high-energy supercontinuum laser.

[0067] The high-energy supercontinuum laser is directly generated by a fiber amplifier, and its spectral energy output is continuously distributed in the optical frequency, concentrated in the near-infrared 1-2μm, or 2-2.5μm. When the spectrum is in the range of 1-2μm, the fiber amplifier is a trivalent ytterbium-doped silica fiber amplifier with a double-cladding structure. When the spectrum range is in the range of 2-2.5μm, the fiber amplifier is a trivalent thulium-doped silica fiber amplifier with a double-cladding structure.

[0068] Furthermore, the pulse width of the high-energy supercontinuum laser is greater than 1 ns and less than 20 ns, the repetition frequency is greater than 10 kHz, and the pulse energy is higher than 10 μJ.

[0069] Furthermore, the output beam of the high-energy supercontinuum laser is a fundamental mode, and the beam quality M2 factor is less than 1.3.

[0070] The pulsed laser output by the high-energy supercontinuum laser is collimated after passing through a beam collimator, and then illuminates a distant target through a wide-spectrum light transmitting and receiving system.

[0071] The wide-spectrum transmitting and receiving system adopts a telescope structure design, which can efficiently collect the echo light signal reflected from the target surface and transmit the echo light signal to the color separation prism combination.

[0072] The color separation prism combination adopts a structural design of a combination of multiple isosceles right-angle prisms, and a two-color spectroscopic film, a long-wave filter film, and a short-wave filter film are plated on the prism interface or the light-emitting surface to achieve spectral channel division.

[0073] Furthermore, the color separation prism combination filters the echo supercontinuum signal into four spectrally separated spectral component signals, and the width of a single spectral channel is not less than 100 nm.

[0074] Furthermore, these spectral component signals are respectively converted into photoelectric by a photodetector, enhanced by an electrical signal amplifier, converted into analog-to-digital by an analog-to-digital converter, and the light intensity values ​​of the four channels are obtained by a four-channel data acquisition card.

[0075] The time interval measuring unit is used to compare the time delay between the trigger signal provided by the control computer and the echo light signal to obtain the flight time of the supercontinuum laser pulse.

[0076] The scanning mechanism is composed of a high-speed two-dimensional scanning galvanometer or a swing mirror, which can realize rapid surface scanning or line scanning of the target area and provide the azimuth information of the radar beam to the data processing unit.

[0077] The data processing unit processes the original information such as the time delay, the four-channel light intensity information, and the azimuth information provided by the scanning structure to obtain the four-channel radar data of the target in the near-infrared band, and then sends it to the data storage unit for storage. Therefore, the four spectral channels of the distance detection realized by the present invention can all provide ranging information, and the ranging accuracy can be improved through simple averaging processing.

[0078] Furthermore, after obtaining the four-channel light intensity information, the present invention can realize two-color, three-color and four-color false color synthesis methods by arbitrarily selecting two channels, three channels or all four channels of the four-channel light to obtain false color point cloud data with bright colors and prominent features.

[0079] The present invention directly utilizes a near-infrared supercontinuum laser and filters the supercontinuum signal into four spectrally separated spectral component signals (there are only four spectral channels) through a color separation prism combination, and the width of a single spectral channel is not less than 100nm (the channel range is extremely large, not a hyperspectral spectrum). The spectral detection band, number of channels, and spectral width are all different, so the information obtained is completely different. In particular, the light pulse energy in a single channel of the present invention is higher, which significantly increases the radar spectral detection distance and is closer to practical application.

[0080] Embodiment 2:

[0081] like Figure 2As shown, the false color laser radar system of the present invention generates a clock signal by a control computer composed of a programmable logic gate array, controls a high-energy supercontinuum laser composed of an ytterbium-doped fiber amplifier, and emits a fundamental mode supercontinuum laser pulse with a repetition frequency of 100kHz, a pulse width of 10ns, a pulse energy of 200μJ, a spectral range of 1000-2000nm, and a beam waist radius of 5μm. The emitted laser pulse becomes parallel light after passing through a beam collimator composed of a parabolic reflector with a focal length of 25mm, and is injected into the transmitting reflector of the wide-spectrum light transmitting and receiving system to achieve effective illumination of the target object within a distance of 200m. The back echo signal after loading the target spectrum is collected by the telescope receiving system of the wide-spectrum light transmitting and receiving system, and then injected into a color separation prism combination formed by pasting six right-angle prisms to filter out four channels with spectral separation and a bandwidth of not less than 200nm, and then converged to the photosensitive surfaces of four indium gallium arsenide photodetectors through focusing lenses respectively, completing the conversion of optical signals to electrical signals. The electrical signal is then amplified by an electrical signal amplifier, and then transmitted to an analog-to-digital converter to be converted into a quantized digital signal, which is then recorded by a four-channel data acquisition card to obtain the intensity information of the four channels. 1 ,I 2 ,I 3 ,I 4 The time interval measurement unit is used to compare the time delay between the trigger signal provided by the control computer and the echo light signal. After calibration, the flight time t of the supercontinuum laser pulse can be obtained. Therefore, combined with the light speed value, the target distance information L=c×t / 2 can be calculated.

[0082] In this embodiment, the scanning mechanism is composed of a high-speed two-dimensional scanning galvanometer, which can record the angle θ between a single laser radar beam and the x-axis direction and the angle φ between a single laser radar beam and the z-axis direction. To this end, taking the radar as the origin of the three-dimensional space coordinate 0, the spatial coordinates of the target point cloud can be obtained as {L×sinφ×cosθ, L×sinφ×sinθ, L×cosφ}.

[0083] The processing unit in this embodiment processes the original information such as the time delay, the four-channel light intensity information, and the azimuth information provided by the scanning structure, and calculates the obtained single-point radar data {L×sinφ×cosθ, L×sinφ×sinθ, L×cosφ, I 1 ,I 2 ,I 3 ,I 4}, and then sent to the data storage unit for storage.

[0084] Subsequently, the control computer controls the scanning mechanism to move to the next detection position, and controls the high-energy supercontinuum laser to emit the next laser pulse, recording the radar's single-point radar data for other spatial positions. Finally, a large number of these single-point radar data are collected to form four-channel radar point cloud data. By selecting two-color, three-color or four-color in the four-channel radar point cloud data, combined with the false color synthesis method, a colorful false color radar point cloud image can be obtained, which can support high-precision resolution and recognition of target categories.

[0085] Figure 3 The figure shows the average radiation flux value formed by the 1000-2000nm supercontinuum beam reaching the target surface in this embodiment. The average irradiation energy is 3W / m 2 / nm is still about 10 times higher than the average radiation flux of sunlight in the near-infrared band. Figure 3 The average radiation flux of another 2000-2500nm high-energy supercontinuum laser composed of a thulium-doped fiber amplifier is also given.

[0086] Figure 4 The figure shows a schematic diagram of the broadband light transmitting and receiving system in this embodiment, wherein the broadband light transmitting system is specifically composed of a beam expander 1, a first plane reflector 2, and a second plane reflector 3, and the two plane reflectors are arranged at 45° with the beam expander. The broadband light receiving system adopts a Cassegrain telescope structure, specifically composed of a secondary reflector 4, a primary reflector 5, a pinhole aperture 6, and a short focal length collimating lens 7. The optical structure of the transmitting system and the receiving system is characterized in that the supercontinuum laser beam is quasi-coaxial with the optical axis of the receiving telescope, and the blind area distance is relatively short.

[0087] Figure 5 The schematic diagram of the dichroic prism assembly structure of this embodiment is shown, which is composed of six right-angle triangular prisms pasted in order, wherein a long-wave filter film is plated at the surface 13 under the condition of 0° incidence, and the corresponding filter wavelength is λ 1 , the two-color spectroscopic film under the condition of 45° incidence is respectively coated on the bevel interface 9, the bevel interface 10, and the surface 11, and the corresponding color separation wavelength is λ 3 , 4 and λ 2 , the short-wave filter film is plated at the 12th position of the hypotenuse interface under 0° incidence condition, and the corresponding filtering wavelength is λ 5 Here λ 1 , 2 , 3 , 4 and λ 5 Set according to channel location requirements.

[0088] Figure 6 Shown is a schematic diagram of the reflection spectra of three types of two-color splitting films under the incident condition of 45° in this embodiment.

[0089] Figure 7 Shown is a schematic diagram of the transmittance spectra of the long-wave pass and short-wave pass filter films under 0° incident conditions in this embodiment.

[0090] According to the combination of the above prism group, long-wave pass filter film, two-color spectroscopic film and short-wave pass filter film, four channels of filtered return light signal output can be finally obtained.

[0091] Figure 8 The diagram shows the shapes of the four spectral channels in this embodiment. The first channel selects a spectral range of λ 1 -λ 2 , the second channel selects the spectral range as λ 2 -λ 3 , the third channel selects the spectral range as λ 3 -λ 4 , the fourth channel selects the spectral range as λ 4 -λ 5 By adjusting these wavelength values, the channel position and bandwidth can be adjusted. In this embodiment, the four channel selection spectrum ranges are 1000-1200nm, 1200-1400nm, 1400-1600nm, and 1600-2000nm respectively.

[0092] Obviously, the described embodiments are only some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0093] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0094] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0095] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0096] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0097] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are included in the scope of the claims of the present invention to be approved.

Claims

1. A false color laser radar system, characterized in that: include: A broadband light transceiver, a color separation prism assembly, a data acquisition system and a control system connected in sequence, wherein the control system is also connected to the broadband light transmitting and receiving system; The control system is used to control the wide-spectrum optical transceiver to emit a laser radar beam to illuminate the target object; The broadband optical transceiver transmits the received echo optical signal reflected by the target object to the dichroic prism assembly; The color separation prism combination divides the echo light signal into multiple spectral channels according to wavelength; The control system is also used to process and synthesize the light beams of multiple spectral channels collected by the data collection unit to obtain false color point cloud data; The color separation prism combination comprises: an even number of prisms with the same structure; The prism is a right-angle prism; The hypotenuses of every two right-angle prisms are pasted together to form a square, and the pasting point is a bevel boundary surface; multiple squares are pasted in pairs to form a non-linear structure; There are six prisms, forming three squares; When the first square and the second square are pasted together, their hypotenuse intersection surfaces are arranged in parallel; The third square is pasted to the second square, and the vertices of the hypotenuse intersection interface thereof intersect to form a right angle; the surface (14) of the second square is arranged perpendicular to the echo optical signal transmitted by the wide-spectrum optical transmitting and receiving system.

2. The system according to claim 1, characterized in that The broadband optical transceiver comprises: a broadband optical transmitting and receiving system, a beam collimator and a high-energy supercontinuum laser; The wide-spectrum light transmitting and receiving system comprises: a wide-spectrum light transmitting system and a wide-spectrum light receiving system which are quasi-coaxially arranged.

3. The system according to claim 2, characterized in that The broadband light emission system comprises: a beam expander, a first plane reflector arranged at 45 degrees to the beam expander, and a second plane reflector arranged parallel to the first plane reflector.

4. The system according to claim 2, characterized in that The high-energy supercontinuum laser is directly generated by a fiber amplifier, emitting fundamental mode supercontinuum laser pulses with a repetition frequency of 100kHz, a pulse width of 10ns, a pulse energy of 10μJ, a spectral range of 1000-2000nm, and a beam waist radius of 5μm, concentrated in the near-infrared 1-2μm, or 2-2.5μm.

5. The system according to claim 4, characterized in that When the spectrum emitted by the high-energy supercontinuum laser is in the range of 1-2 μm, the optical fiber amplifier is a trivalent ytterbium-doped quartz optical fiber amplifier with a double-cladding structure; When the spectrum range is within the range of 2-2.5 μm, the optical fiber amplifier is a trivalent thulium ion-doped quartz optical fiber amplifier with a double-cladding structure.

6. The system according to claim 2, characterized in that The wide-spectrum light receiving system comprises a reflector, a main reflector, a pinhole diaphragm and a short focal length collimating lens arranged in sequence; The reflector is a convex mirror, and the convex surface of the reflector faces the main reflector; The mirror surface of the main reflector has a certain curvature, and its concave surface faces the reflector; The main reflector is provided with a light-transmitting hole; The midpoint of the reflector, the light-transmitting hole of the main reflector, the light-transmitting hole of the pinhole diaphragm and the midpoint of the short-focal-length collimating lens are located on the same straight line.

7. The system according to claim 1, characterized in that Different optical films are also coated on the light-emitting surface and hypotenuse interface of the prism.

8. The system according to claim 7, characterized in that The optical film includes: a long-wave filter film, a two-color spectroscopic film and a short-wave filter film; The surface (13) of the third square is coated with a long-wave pass filter film under 0° incidence condition; The hypotenuse interface (9) of the second square, the hypotenuse interface (10) of the first square, and the surface (11) of the first square are respectively coated with two-color splitting films of different wavelengths of split light under an incident condition of 45 degrees; The hypotenuse interface (12) of the third square is plated with a short-wave pass filter film under 0° incident conditions.

9. The system according to claim 7, characterized in that There are four light emitting surfaces.

10. The system according to claim 7, characterized in that The data acquisition system comprises: a four-channel data acquisition card and four channel units; Each channel unit includes a photodetector, a signal amplifier and an analog-to-digital converter connected in sequence; The four-channel data acquisition card is used to receive light intensity information of each channel.

11. The system according to claim 10, characterized in that The control system comprises: a control computer, a time interval measuring unit, a scanning mechanism, a data processing unit and a data storage unit; The time interval measuring unit is used to: compare the time delay between the trigger signal provided by the control computer and the echo light signal; The scanning mechanism is used to: record the azimuth information of a single laser radar beam; The data processing unit is used to: perform calculations based on the time delay of the trigger signal and the echo light signal obtained by the time interval measurement unit, the azimuth information determined by the scanning mechanism, and the four-channel light intensity information obtained by the four-channel data acquisition card to obtain single-point radar data; The data storage unit is used to store the single-point radar data calculated by the data processing unit.

12. The system according to claim 11, characterized in that The data processing unit is also used to integrate a large amount of single-point radar data stored in the data storage unit to form multi-channel radar point cloud data; and obtain a false color radar point cloud image with multiple colors corresponding to the target object based on the multi-channel radar point cloud data combined with a false color synthesis method.

13. The system according to claim 11, characterized in that The radar point data includes: the radar point spatial coordinates and multi-channel light intensity information corresponding to the target object.

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