A detection device, a laser radar system and a terminal

Abstract

The application provides a detection device, comprising: a transceiver component, configured to emit N emission sub-beams to a target scanning space at different emission angles, and to converge N reflection sub-beams into a reflection beam; wherein the wavelengths of the N emission sub-beams are different, the emission angles correspond to the wavelengths of the emission sub-beams, and the N reflection sub-beams are formed by reflection of the N emission sub-beams after detection of at least one probe; wherein N is a positive integer greater than 1; a wavelength division component, configured to obtain the N reflection sub-beams corresponding to different wavelengths according to the reflection beam; and a detector array, configured to output corresponding electrical signals according to the N reflection sub-beams from the wavelength division component; wherein the detector array comprises N detectors corresponding to the N reflection sub-beams. The application can effectively solve the crosstalk problem among detectors.

Description

Technical Field

[0001] This application relates to the field of lidar technology, and in particular to a detection device, lidar system and terminal. Background Technology

[0002] Laser detection devices, also known as lidar (Light Detection and Ranging), are devices that emit laser beams to detect the position, velocity, and other characteristics of targets. Used to perceive parameters of the surrounding environment, they are often referred to as the "eyes" of machines and have wide applications in surveying, exploration, and autonomous driving.

[0003] To improve scanning speed, existing lidar typically employs a multi-line structure, and its working principle is as follows: Figure 1a As shown, multiple photodetectors are arranged vertically to form a detector array. A focusing lens concentrates reflected light from different angles onto different photodetectors, achieving vertical scanning. A horizontally rotating transceiver mechanism then enables three-dimensional scanning. However, in this type of lidar system, due to factors such as the performance of the focusing lens and the beam performance, the light signal received by a particular photodetector may contain light signals outside its designed angle, affecting detection accuracy. For example... Figure 1b As shown, a highly reflective target not only causes a response on its corresponding photodetector, but also induces a weaker response in the detectors around its corresponding photodetector, thus causing crosstalk.

[0004] Therefore, there is an urgent need to develop a laser detection device that can effectively avoid crosstalk. Summary of the Invention

[0005] The embodiments of this application provide a detection device that effectively solves the crosstalk problem between detectors in existing detection devices by emitting multi-wavelength light beams so that different detectors receive light beams of different wavelengths.

[0006] To achieve the above objectives, the embodiments of this application adopt the following technical solutions: This application provides a laser detection device, comprising: a transceiver assembly for emitting N sub-beams at different emission angles toward a target scanning space, and converging N reflective sub-beams into a reflected beam; wherein each of the N emitting sub-beams has a different wavelength, the emission angle corresponds to the wavelength of the emitting sub-beam, and the N reflective sub-beams are beams formed by reflections after the N emitting sub-beams detect at least one detector object, where N is a positive integer greater than 1; a wavelength division multiplexing (WDM) assembly for acquiring the N reflective sub-beams corresponding to different wavelengths based on the reflected beam; and a detector array for outputting corresponding electrical signals based on the N reflective sub-beams from the WDM assembly; wherein the detector array comprises N detectors, and the N detectors correspond to the N reflective sub-beams.

[0007] The detection device in this application embodiment emits beams of different wavelengths at different emission angles into the target scanning space through a transceiver component, and converges them to a wavelength division multiplexing (WDM) component. The WDM component then distributes the beams of different wavelengths to different detectors, enabling different detectors to receive beams of different wavelengths, thereby fundamentally solving the crosstalk problem between detectors.

[0008] In another possible implementation, a laser generating component is also included, which generates a probe beam comprising the aforementioned N emitter sub-beams and emits it toward the transceiver component.

[0009] In another possible implementation, the wavelength division component includes at least a wavelength division multiplexer, which includes N wavelength channels, each corresponding to one of the wavelengths of the N reflector beams, and N detectors corresponding to the outputs of the N wavelength channels.

[0010] Wavelength division multiplexers achieve optical channel separation through wavelength division multiplexing, resulting in stable performance, extremely high isolation, and no influence from the transceiver component structure design. They overcome the problem of inter-channel crosstalk caused by the non-ideal characteristics of focusing devices, which is difficult to overcome in traditional solutions based on spatial dimension-based optical channel separation. Furthermore, they are cost-controllable and have high feasibility.

[0011] In another possible implementation, to further achieve optical channel separation, the wavelength division multiplexing (WDM) assembly also includes N filtering elements, the passing wavelengths of which correspond to the wavelengths of the N reflector beams. The N filtering elements are respectively disposed between the output ends of the N wavelength channels and the N detectors, so that different detectors receive beams of different wavelengths.

[0012] In another possible implementation, an optical circulator is also included, which includes at least a first port, a second port, and a third port, wherein the first port to the second port forms an optical channel, and the second port to the third port forms an optical channel; the first port is connected to the laser generating component, the second port is connected to the transceiver component, and the third port is connected to the wavelength division multiplexing (WDM) component.

[0013] By setting up an optical circulator, the transceiver component can transmit a beam into the target scanning space and receive the transmitted beam and converge it to the wavelength division component to separate beams of different wavelengths.

[0014] In another possible implementation, the laser generating assembly includes at least a single-frequency laser and an optical resonator. The single-frequency laser is used to emit single-frequency laser light. The optical resonant cavity is disposed on the transmission path of the single-frequency laser light and is used to act on the single-frequency laser light to generate M sub-beams. The wavelengths of the M sub-beams are different, and M is a positive integer greater than or equal to N.

[0015] In another possible implementation, the laser generating component further includes a spectrum shaping component; The spectrum shaping component is used to obtain N sub-beams from the M sub-beams, wherein the wavelengths of any two sub-beams in the N sub-beams are different, and the power difference between any two sub-beams in the N sub-beams is less than or equal to a preset threshold.

[0016] In another possible implementation, the laser generating component further includes an optical amplifier; The optical amplifier is used to increase the power of each of the N sub-beams by a preset factor to form the N emission sub-beams.

[0017] In another possible implementation, the adjacent wavelengths of the N emitting sub-beams are equally spaced; The transceiver assembly includes at least a vertical transmitting assembly for transmitting the transmitting sub-beams of different wavelengths at different elevation angles into the target scanning space.

[0018] In another possible implementation, the laser generating component is also used to adjust the number of N emitting sub-beams in the probe beam and / or adjust the adjacent wavelength spacing of the N emitting sub-beams.

[0019] In another possible implementation, the vertical launching assembly includes at least a collimator and a convex lens; The collimator is positioned off-center from the focal point of the convex lens and on the focal plane of the convex lens, for collimating the probe beam onto the convex lens.

[0020] In another possible implementation, the vertical emission assembly includes at least a collimator and a diffraction grating; The collimator is used to collimate the probe beam and direct it onto the diffraction grating.

[0021] The vertical emission assembly of this application realizes solid-state scanning in the vertical direction, avoiding the problems of poor reliability, low accuracy and high cost of the mechanical rotating scanning mechanism of existing detection devices.

[0022] In another possible implementation, the laser generating component is also used to sequentially and holistically adjust the wavelengths of the N emitting sub-beams within a preset wavelength range; The transceiver assembly also includes at least a horizontal transmission assembly; The horizontal emitting component is positioned on the transmission path of the beam emitted by the vertical emitting component, and is used to emit the emitting sub-beams of different wavelengths at different azimuth angles to the target scanning space according to different wavelengths.

[0023] In another possible implementation, the horizontal emission assembly includes at least one dispersive optical element disposed on the transmission path of the beam emitted by the vertical emission assembly, thereby emitting the emission sub-beams of different wavelengths at different azimuth angles into the target scanning space.

[0024] In another possible implementation, the horizontal emission assembly further includes at least one convex mirror disposed on the transmission path of the reflected beam of the dispersive optical element.

[0025] In another possible implementation, the adjacent wavelength interval is greater than the preset wavelength range.

[0026] The horizontal launching component of this application realizes solid-state scanning in the horizontal direction, and combined with the vertical launching component, realizes three-dimensional scanning of the target detection space.

[0027] In another possible implementation, the transceiver component further includes at least a horizontal scanning component disposed on the transmission path of the light beam emitted by the vertical transmitting component. The horizontal scanning component includes a reflective surface that rotates about a vertical axis to reflect the light beam emitted by the vertical transmitting component at different times and at different angles into the target scanning space to achieve horizontal scanning.

[0028] Optionally, the horizontal scanning component includes at least a MEMS scanning component.

[0029] In another possible implementation, the laser generating component includes at least a broadband laser for emitting broadband laser light.

[0030] In another possible implementation, the laser generating component further includes a spectrum shaping component disposed on the transmission path of the laser generated by the broadband laser, for acquiring N sub-beams of different wavelengths.

[0031] In another possible implementation, the laser generating component further includes an optical amplifier for increasing the power of each of the N sub-beams by a preset factor.

[0032] Secondly, this application also provides a lidar system, which includes at least the detection device described in the first aspect.

[0033] Thirdly, this application also provides a terminal, which includes at least the detection device of the first aspect or the lidar system of the second aspect. Attached Figure Description

[0034] The accompanying drawings used in the description of the embodiments or prior art are briefly introduced below.

[0035] Figure 1a This is a schematic diagram of the working principle of an existing lidar system. Figure 1b A schematic diagram illustrating crosstalk generated in an existing lidar system; Figure 2a A schematic diagram of the pixel array structure of the single-photon avalanche detector provided for the first scheme; Figure 2b A schematic diagram of the transceiver system provided for the second scheme; Figure 2c A schematic diagram illustrating the working principle of the detection device provided for the third scheme; Figure 3 This is a schematic diagram of the detection device provided in the embodiments of this application; Figure 4 This is a schematic diagram of the structure of the laser generating component provided in Embodiment 1 of this application; Figure 5 This is a schematic diagram of the transceiver component provided in Embodiment 1 of this application; Figure 6 The wavelength distribution during detection scanning by the detection device provided in Embodiment 1 of this application; Figure 7 This is a schematic diagram showing the correspondence between the reflective component and the detector array provided in Embodiment 1 of this application; Figure 8 This is a schematic diagram of the transceiver component provided in Embodiment 2 of this application; Figure 9 The wavelength distribution during detection scanning by the detection device provided in Embodiment 2 of this application; Figure 10This is a schematic diagram of the structure of the laser generating component provided in Embodiment 2 of this application. Detailed Implementation

[0036] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0037] In the description of this application, the terms “center,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0038] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation", "connection" and "joining" should be interpreted broadly, for example, they can be fixed connections, detachable connections, mating connections or integral connections; those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0039] The working principle of a laser detection device (i.e., LiDAR, lidar) is to emit a laser beam toward the target and then receive the reflected laser beam back from the target. Different detectors determine parameters such as the distance, speed, orientation, height, attitude, and shape of the target based on the reflected laser beam back from different targets.

[0040] Different detectors have different optical channels, and different optical channels correspond to different reflected laser beams from different targets. If a reflected laser beam from a target enters another optical channel and causes a response from another detector, crosstalk will occur, which will seriously affect the accuracy of the laser detection device in detecting the target.

[0041] To address the crosstalk problem in existing laser detection devices, algorithmic threshold filtering is generally used to eliminate crosstalk effects. However, algorithmic threshold filtering inevitably leads to the loss of information from the reflected laser beam, affecting the performance of the laser detection device.

[0042] The first approach is to design the detector array as a single-photon avalanche detector (SPAD) pixel array with an interleaved arrangement to receive optical signals in order to reduce crosstalk.

[0043] Figure 2a This is a schematic diagram of the pixel array structure of a single-photon avalanche detector. Figure 2aAs shown, the single-photon avalanche detector pixel array 210 includes an array of pixels 211, each pixel 211 being composed of multiple single-photon avalanche detectors (SPADs) 2110. Each pixel 211 is equivalent to an independent photodetector. After a light pulse is focused onto a pixel 211 by a lens, different SPADs within the pixel independently respond to the light signal, reporting the detected photon data and the corresponding time delay. Subsequently, using the pixel as the smallest unit, the responses of each SPAD within the pixel are accumulated to obtain the final detection structure of that pixel, which is then output.

[0044] The first approach involves modifying the pixel arrangement, changing the rectangular arrangement in the mainstream framework to a parallelogram arrangement, thereby increasing the distance between pixels without reducing pixel density. Therefore, in the case of large, distant light spots, this approach can effectively alleviate the crosstalk problem caused by a single light spot covering multiple pixels.

[0045] However, this scheme increases pixel distance through staggered pixel arrangement, but the rate of increase is not significant. Assuming equal horizontal and vertical pixel distances, the increase in lateral distance is unlikely to exceed 11.8%, resulting in poor crosstalk suppression. Furthermore, this scheme is only suitable for scenarios requiring increased lateral distance and cannot be applied to single-row detector arrays.

[0046] The second approach is to modify the transceiver system to emit a laser beam with high collimation performance to suppress crosstalk between different detector channels.

[0047] Figure 2b This is a schematic diagram of the transceiver system for the second scheme. (Example:) Figure 2b As shown, the transceiver system includes a lens 221 and a micro-optical layer consisting of an aperture layer 222, a collimating lens layer, a filter layer 224, and a photodetector layer. The aperture layer 222 is an aperture array composed of multiple apertures 2220; the collimating lens layer is a collimating lens array composed of multiple collimating lenses 223; the filter layer 224 is a filter array composed of multiple filters; and the photodetector layer is a photodetector array composed of multiple photodetectors 225. Each aperture in the aperture array, each collimating lens in the collimating lens array, each filter in the filter array, and each photodetector in the photodetector array are arranged in a one-to-one correspondence, with each aperture and its corresponding collimating lens, filter, and photodetector forming the optical path for that photodetector.

[0048] The light reflected from the target at different angles is converged at different positions on the surface of the micro-optical layer by lens 221. The aperture layer 222 in the micro-optics layer has corresponding openings for the optical channels of different photodetectors to achieve light reception, and physically filters out light from other positions to reduce crosstalk between channels. After passing through the aperture layer, the divergent beams are re-converged into collimated beams by the corresponding collimating lens 223, and after passing through a filter to further eliminate external ambient light interference, they are received by the photodetector corresponding to the channel. This scheme optimizes the performance of the receiving optical system using the micro-optical layer.

[0049] However, this approach requires the fabrication of the micro-optical layer and precise alignment between the micro-optical layer and the lens system, which places high demands on the manufacturing process, resulting in excessive costs and complex procedures. Furthermore, this approach still achieves channel isolation in the spatial dimension, limiting its crosstalk resistance in specific situations (such as near-range, high-intensity point reflection targets).

[0050] The third approach is to use a liquid crystal panel to realize an optical phased array. By modulating the liquid crystal panel to form a liquid crystal phased array, the emission angle of the light beam reflected by the liquid crystal phased array is controlled to achieve scanning.

[0051] Figure 2c This is a schematic diagram illustrating the working principle of the detection device in the third scheme. Figure 2c As shown, the laser emitting module 231 generates a laser beam and emits it towards the lens 233, which then collimates the laser beam onto the liquid crystal phased array 232. By applying different voltages to different positions of the liquid crystal phased array 232, the phase difference between the emitted light at different positions can be controlled. By appropriately adjusting the phase of each position of the phased array 232 using the liquid crystal, a beam with a controllable emission angle can be obtained through the interference between the beams, thereby achieving target scanning. This avoids the effects of crosstalk from a system architecture perspective.

[0052] However, this technical solution has two main problems. First, the liquid crystal electronic control frequency is low, the phase switching speed is slow, and the phase control accuracy is poor, resulting in a slow scanning speed, low emission angle control accuracy, and severe sidelobe effects. Second, since the components related to phased array technology are still under research at this stage, there is no mature solution that can be mass-produced, resulting in low technical feasibility.

[0053] Taking the above factors into consideration, this application provides a detection device that separates different detector channels along the wavelength dimension to suppress channel crosstalk. By utilizing a focal bias structure or rationally deploying diffractive optics to construct a laser transceiver assembly, light with different wavelengths emitted from the same position can be emitted at different emission angles after entering the transceiver assembly, and a relatively linear correlation exists between wavelength and emission angle. At the receiving end, optical signals with different emission angles and corresponding wavelengths are uniformly received, and the different wavelength beams are separated by an optical fiber wavelength division multiplexer, allowing each channel to receive them individually. Thanks to the excellent wavelength selectivity of optical fiber devices, the channel isolation of the detection device is significantly increased, effectively suppressing crosstalk between channels.

[0054] The detection device provided in the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0055] Figure 3 This is a schematic diagram of the detection device provided in an embodiment of this application. Figure 3 As shown, the detection device provided in this application embodiment includes, but is not limited to, at least one of a laser generating component 31, a transceiver component 32, a wavelength division multiplexing (WDM) component 33, and a detector array 34. The laser generating component 31 generates a detection beam with multiple wavelength components. The transceiver component 32 is deployed along the transmission path of the detection beam generated by the laser generating component 31, emitting sub-beams of different wavelength components of the detection beam at different emission angles according to different wavelengths towards the target detection space. When the sub-beams of different wavelengths encounter the detection target (such as...),... Figure 3 In the process of detecting target 1, target 2, target 3, ..., target N, the detected targets reflect light, forming reflective sub-beams of different wavelengths. The transceiver assembly converges these reflective sub-beams into a single reflected beam and sends it to the wavelength division multiplexing (WDM) component 33. The WDM component then decomposes the reflected beam into reflective sub-beams of different wavelengths and distributes these sub-beams to different detectors in the detector array 34. The detectors output corresponding electrical signals based on the different reflective sub-beams. This achieves isolation between different detector channels in the wavelength dimension, fundamentally solving the crosstalk problem between different detector channels.

[0056] Example 1

[0057] Figure 4 This is a schematic diagram of the structure of the laser generating component provided in Embodiment 1 of this application. Figure 4 As shown, the laser generating assembly includes a single-frequency laser 311, an optical resonant cavity 312, a spectrum shaping component 313, and an optical amplifier 314 disposed on the transmission path of the laser beam emitted by the single-frequency laser. The optical resonant cavity, the spectrum shaping component, and the optical amplifier can be arranged sequentially.

[0058] A single-frequency laser 311 emits a single-frequency laser beam, which, due to strong nonlinear effects in the optical resonant cavity 312, generates a multi-wavelength laser beam with M wavelength components (M being a positive integer greater than or equal to N). The multi-wavelength laser beam enters the spectrum shaping component 313 for spectrum shaping, filtering out redundant wavelength components to obtain a laser beam with N wavelength components (N being a positive integer greater than 1) and making the power of each wavelength component flat. Finally, it is amplified by the optical amplifier 314 to improve the detection signal-to-noise ratio and measurement distance, and sent to the transceiver component to emit the N wavelength components of the laser beam (i.e., N emitted sub-beams) into the detection space at different emission angles according to different wavelengths for detection scanning.

[0059] Optionally, the optical resonator 312 is an optical microring resonator, which can be used to generate hundreds of wavelength components with adjacent wavelength intervals of 1-2 nm by a single-frequency laser. The number of wavelength components and the intervals between adjacent wavelengths can be adjusted by regulating the state of the optical microring resonator. Considering the subsequent scanning and detection effects, a laser beam with multiple wavelength components and equal or similar adjacent wavelength intervals can be generated by adjusting the optical microring resonator.

[0060] Optionally, the spectrum shaping component 313 may include an optical spectrum shaper or filter, etc., as long as it is an optical component that can select a specific wavelength component and flatten the power of the wavelength component. This application does not limit it.

[0061] In some implementations, the laser generating component may consist only of a single-frequency laser 311 and an optical resonant cavity 312 disposed on the transmission path of the laser beam emitted by the single-frequency laser. The optical resonant cavity 312 directly acts on the single-frequency laser beam to generate a laser beam with M wavelength components, and directly sends the laser beam with M wavelength components into the transceiver component to complete the detection and scanning.

[0062] In other implementations, the laser generating assembly may consist only of a single-frequency laser 311, an optical resonator 312 positioned along the transmission path of the laser beam emitted by the single-frequency laser, and a spectrum shaping assembly 313. The spectrum shaping assembly 313 filters out redundant wavelength components from the M wavelength components of the laser beam generated by the optical resonator, obtaining a laser beam with N wavelength components and flattening the power of each wavelength component. The N wavelength components of the laser beam are then sent to the transceiver assembly to complete the detection scan.

[0063] Figure 5 This is a schematic diagram of the transceiver component provided in Embodiment 1 of this application. Figure 5As shown, the transceiver assembly 32 includes a vertical transmitting assembly 322 and a horizontal transmitting assembly 323. The transceiver assembly 32 is coupled to the laser generating assembly 31 and the wavelength division multiplexing (WDM) assembly 33 via an optical circulator 35. It is connected via optical fibers to the first port of the laser generating assembly 31 and the first port of the optical circulator 35, the second port of the transceiver assembly 32 and the second port of the optical circulator 35, and the third port of the WDM assembly 33 and the optical circulator 35. This allows the probe beam generated by the laser generating assembly 31 to enter the optical circulator 35 through the first port and exit from the second port to the transceiver assembly. The reflected beam received by the transceiver assembly 32 enters the optical circulator 35 through the second port and exits from the third port to the WDM assembly 33. This interoperability between the transceiver assemblies simplifies the system structure and improves transmission efficiency.

[0064] Of course, this application does not limit the optical transmission medium between the laser generating component, the optical circulator, the transceiver component and the wavelength division component to optical fiber, and other optical transmission media, such as air, may also be used.

[0065] In one design, the vertical emission assembly 322 includes a collimator 3221 and a convex lens 3222. The collimator 3221 is positioned off-center from the focal point of the convex lens 3222 on the focal plane of the convex lens 3222, thereby collimating the laser beam with N wavelength components in the probe beam to different positions on the convex lens. In this way, there is an optical path difference between the N wavelength components of the laser beam. This optical path difference will cause interference after the incident light reaches the surface of the convex lens, and only light at a specific angle can be emitted. This specific angle is related to the wavelength of the light, realizing the transformation of the incident light wavelength to the emission angle, that is, realizing the emission of the laser beam with N wavelength components at different elevation angles according to different wavelengths into the target scanning space.

[0066] It also achieves solid-state scanning in the vertical direction, avoiding the problems of poor reliability, low accuracy and high cost of the mechanical rotating structure in traditional lidar.

[0067] Of course, the vertical emission component 322 is not limited to the collimator and convex lens structure. As long as it can achieve the function of emitting at different emission angles according to different wavelengths, it is acceptable. For example, the convex lens can also be replaced with a diffraction grating. The collimator will incident the probe beam onto the surface of the diffraction grating, and interference will occur, so as to realize the emission of laser beams with N wavelength components at different elevation angles according to different wavelengths into the target scanning space.

[0068] The horizontal emitting component 323 is deployed along the transmission path of the beam emitted by the vertical emitting component. It includes at least one optical dispersive element, emitting laser beams of different wavelengths at different azimuth angles into the target scanning space. The laser generating component sequentially adjusts the wavelengths of N wavelength components of the laser beam within a preset wavelength range. For example, by sequentially emitting single-frequency lasers with different center wavelengths from a single-frequency laser, a small-range overall adjustment of the N wavelength components of the laser beam is achieved, thereby realizing three-dimensional solid-state scanning of the target space. It should be explained here that sequentially adjusting the wavelengths of the N wavelength components of the laser beam means that the laser generating component adjusts the wavelengths of the N wavelength components of the laser beam at different times. For example, at the first moment, the wavelengths of the N wavelength components of the laser beam generated by the laser generating component are λ1, λ2, ..., λ... n At the second moment, the wavelengths of the N wavelength components of the laser beam generated by the laser generating component are adjusted as follows: λ1 + Δλ, λ2 + Δλ, ... λ n +△λ, at the third moment, the wavelengths of the N wavelength components of the laser beam are adjusted as follows: λ1+2△λ, λ2+2△λ, ..., λ n +2△λ, and so on, the overall wavelength adjustment of the laser beam of N wavelength components at time k is: λ1+(k-1)△λ, λ2+(k-1)△λ, ... λ n +(k-1)△λ. It's understandable that in practical applications, electromagnetic waves with only a single wavelength cannot be generated. Even the purest laser has a certain wavelength distribution range. For example, if a laser with a wavelength of 1550nm is needed, the actual generated laser might have wavelengths between 1549-1551nm, with the 1550nm wavelength having the highest energy, which is the center wavelength. In other words, the center wavelength is the wavelength of the component with the highest energy within the wavelength range.

[0069] In order to ensure that the small-scale overall adjustment of the laser beam with N wavelength components only affects the horizontal scanning component and has as little impact on the vertical emitting component as possible, the horizontal scanning component needs to be more sensitive to the wavelength of light than the vertical emitting component.

[0070] In one example, to improve the wavelength sensitivity of the horizontal emission component, the optical dispersion element of the horizontal emission component 323 includes multiple reflection gratings 3231, one of which receives the light beam emitted by the vertical emission component, and the other emission beams are sequentially deployed on the reflection path of the previous reflection grating to further increase the different reflection angles of the light beams of different wavelengths, thereby improving the wavelength sensitivity of the horizontal emission component.

[0071] In another example, to further enhance the sensitivity of the horizontal emission component to wavelength, a convex reflector 3232 is also provided in the horizontal emission component 323. The convex reflector 3232 is located on the reflection path of the last reflective grating, so that the reflected beam can be directed at the target scanning space at different angles, so that even if the wavelength of the beam changes slightly, it can be emitted at different exit angles.

[0072] like Figure 6 As shown, if the scanning emission angle matrix size of the detection device is n If k is the wavelength of light emitted by the laser generating component, then k different wavelength detection beams are emitted by the transceiver component at k different elevation angles to achieve vertical scanning. Simultaneously, the center wavelength of the single-frequency laser emitted by the single-frequency laser is adjusted sequentially, causing a small-range overall frequency shift across the spectrum for each of the k different wavelengths. This results in a consistent change in the horizontal emission angle of each of the k wavelength components, thereby achieving three-dimensional scanning of the target space.

[0073] To ensure that a change in wavelength does not significantly affect vertical scanning, the following conditions must be met for any wavelength: This means that the wavelength change range during horizontal scanning should be less than the interval between adjacent wavelengths. It can be understood that adjacent wavelengths refer to the two wavelengths with the smallest wavelength difference in the probe beams of different wavelengths. For example... Figure 6 As shown, This indicates the wavelength interval between adjacent wavelengths of the probe beams emitted during vertical scanning. This indicates the wavelength adjustment range of any sub-beam of any wavelength among the different wavelengths of the probe beam emitted during horizontal scanning.

[0074] like Figure 7 As shown, the output ports of each wavelength channel of the wavelength division component 33 are set one-to-one with each detector of the detector array 34, so that the wavelength division component can separate the reflected beam into reflected sub-beams of different wavelengths and then incident them on each detector in the detector array 34 to achieve the purpose of isolating each detector channel.

[0075] To further increase the isolation of each detector channel, a filter element array 36 is set between the output port of each wavelength channel of the wavelength division component 33 and the detector array. See also... Figure 7 Each filter element in the filter element array 36 is configured in a one-to-one correspondence with each detector in the detector array 34, that is, each filter element in the filter element array 36 is configured in a one-to-one correspondence with the output port of each wavelength channel of the wavelength division component 33. It can be understood that the transmission wavelength of each filter element in the filter element array 36 corresponds to the transmission wavelength of each wavelength channel of the wavelength division component 33.

[0076] Wavelength division multiplexing (WDM) technology refers to separating components with different center wavelengths in a beam of light based on wavelength, forming distinct beams.

[0077] The wavelength division multiplexing (WDM) component is designed to receive optical signals from the transceiver unit, split the received optical signals into beams according to their wavelengths, and send the split beams of each wavelength to a photodetector array to complete the detection function.

[0078] Optionally, the wavelength division multiplexing (WDM) component can be a dense wavelength division multiplexer (DWDM), which is widely used in optical fiber communication systems. DWDM is widely used in optical fiber communication for wavelength division multiplexing / demultiplexing and can meet the functional requirements of the above-mentioned WDM component.

[0079] Optionally, the filtering element is a narrowband filter, and the dense wavelength division multiplexer can provide isolation of up to 40 dB, while the filter can further provide isolation of more than 20 dB, further improving channel isolation.

[0080] Of course, the filtering element is not limited to narrowband filters; any optical filtering element that can achieve the filtering effect of this application is acceptable, such as a fiber Bragg grating.

[0081] Considering the problem that traditional lidar cannot avoid the influence of the optical characteristics of the focusing device when using space to achieve channel isolation, Embodiment 1 of this application innovatively proposes to achieve channel isolation using the wavelength dimension. First, a multi-wavelength light source is used instead of the traditional single-wavelength light source, opening up a new wavelength dimension for the subsequent system. Then, each wavelength of the multi-wavelength light source is configured with a corresponding wavelength window. Through a specially designed optical transceiver component, different wavelength windows can correspond to different vertical channels, achieving a one-to-one mapping from wavelength windows to vertical channels. Subsequently, after receiving the multi-wavelength reflected light signals, a wavelength division multiplexing (WDM) component is used to separate the reflected light signals in the wavelength dimension, achieving high separation degree, stable separation performance, and insensitivity to the optical characteristics of the focusing device. Finally, at the receiving end, a narrowband filter is used for further filtering, achieving a vertical channel isolation degree far higher than that of current lidar, eliminating the adverse effects of channel crosstalk.

[0082] Due to the inherent problems of poor reliability, low accuracy, and high cost in traditional LiDAR's mechanical rotating scanning mechanism, Embodiment 1 of this application innovatively proposes to establish wavelength-scanning angle correlation characteristics using an improved optical transceiver assembly, thereby achieving emission angle scanning by changing the light source wavelength. First, a multi-wavelength light source with tunable wavelengths is used as the detection light source to provide corresponding functions for coarse-grained wavelength division and fine-grained scanning. Second, this application proposes an optical transceiver assembly with wavelength-emission angle correlation, where the wavelength-vertical emission angle sensitivity is weak, while the wavelength-horizontal emission angle sensitivity is strong. Therefore, multiple wavelength components of the multi-wavelength light source can be used as coarse-grained wavelength division, projected onto different vertical emission angles through the optical transceiver assembly, enabling parallel measurement of multiple vertical channels. Simultaneously, tuning the multi-wavelength light source to achieve a small-range frequency shift in its spectrum can serve as fine-grained wavelength scanning, projected onto different horizontal emission angles through the optical transceiver assembly, achieving horizontal scanning.

[0083] Example 2

[0084] The difference between this embodiment and Embodiment 1 is that MEMS is used to replace the horizontal scanning component in the transceiver components of Embodiment 1. By combining the wavelength scanning mechanism with MEMS (Micro-ElectroMechanical System), solid-state scanning of the probe space is achieved through one-dimensional wavelength scanning and one-dimensional MEMS scanning.

[0085] like Figure 8 As shown, the transceiver assembly of Embodiment 2 includes a vertical transmitting assembly 322 and a micro-electromechanical system 324 deployed on the transmission path of the beam emitted by the vertical transmitting assembly 322. The micro-electromechanical system 324 galvanometer mirror enables rapid horizontal scanning.

[0086] Figure 9 The wavelength distribution during detection scanning by the detection device provided in Embodiment 2 of this application. For example... Figure 8 As shown, the laser generating component only needs to generate N beams of different wavelengths. Since horizontal scanning is achieved using MEMS, there is no need to adjust the laser generating component to achieve a small-range overall frequency shift across the spectrum for different wavelengths. This overcomes the drawbacks of the high design difficulty of the horizontal emission component in Embodiment 1 and the high difficulty of two-dimensional MEMS scanning control in traditional lidar, simplifying the system and reducing system cost and complexity.

[0087] Since the laser generating component does not require a small-scale overall frequency shift of different wavelengths across the spectrum, the laser generating component can be simplified, further simplifying the structure and reducing the structural complexity and cost of the detection device.

[0088] like Figure 9As shown, the laser generating assembly includes a broadband light source generator 315, a spectrum shaping assembly 313 and an optical amplifier 314 sequentially disposed on the transmission path of the laser beam emitted by the broadband light source generator 315.

[0089] The broadband light source generator 315 generates broadband laser light, which is directly fed into the spectrum shaping component 313 for spectrum shaping, filtering out redundant wavelength components and making the power of each wavelength component flat. Then, it is amplified by the optical amplifier 314 to improve the detection signal-to-noise ratio and measurement distance, and then sent to the transceiver component to complete scanning and ranging tasks.

[0090] In Embodiment 2, the laser generating component no longer requires characteristics such as small-range overall frequency shifts of different wavelengths in the spectrum, spacing between adjacent wavelengths, and wavelength tunability. It only needs to have multi-wavelength characteristics. Therefore, a broadband light source generator capable of generating a continuous spectrum can be selected as the light source, such as a supercontinuum light source generator or an ASE light source generator, or other optical devices that can achieve broadband output. The optical resonator in Embodiment 1 is not required, further simplifying the device.

[0091] This application also provides a lidar system including one or more of the above-mentioned detection devices, which obtains motion parameters of the target in multiple detection areas based on the electrical signals detected by the detection devices.

[0092] This application also provides a terminal that includes the aforementioned detection device or lidar system. This vehicle terminal is used in motor vehicles, surveying terminals, and other applications employing lidar systems.

[0093] Taking motor vehicles as an example, this paper explains the application of detection devices or lidar systems on motor vehicles. A lidar system is installed on the motor vehicle and communicates with the autonomous driving system on the motor vehicle. Detection devices are installed at multiple locations on the motor vehicle (ideally with detection points covering the entire panorama around the motor vehicle, but detection points can also be deployed according to actual needs). The detection device at each detection point completes a spatial scan and obtains spatial point cloud data for each detection point. The autonomous driving system of the motor vehicle merges the spatial point cloud data of each detection point together to form spatial point cloud information of the vehicle's surrounding environment, thereby perceiving the surrounding environment information.

[0094] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0095] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A detection device, characterized in that, include: A transceiver assembly is used to transmit N transmitting sub-beams at different emission angles toward a target scanning space, and to converge N reflecting sub-beams into a reflected beam; wherein, the wavelengths of each of the N transmitting sub-beams are different, the emission angles correspond to the wavelengths of the transmitting sub-beams, and the N reflecting sub-beams are beams formed by reflections after the N transmitting sub-beams detect at least one object, where N is a positive integer greater than 1; A wavelength division multiplexing (WDM) component is used to acquire the N reflective sub-beams corresponding to different wavelengths based on the reflected beam; A detector array for outputting corresponding electrical signals based on the N reflector beams from the wavelength division component; The detector array comprises N detectors, and the N detectors correspond to the N reflector beams; The transceiver assembly includes at least a vertical transmitting assembly for transmitting the transmitting sub-beams of different wavelengths at different elevation angles into the target scanning space; The transceiver assembly further includes at least a horizontal transmitting assembly, which is disposed on the transmission path of the beam emitted by the vertical transmitting assembly and is used to transmit the transmitting sub-beams of different wavelengths at different azimuth angles to the target scanning space according to different wavelengths.

2. The detection device according to claim 1, characterized in that, Also includes: A laser generating component for generating a probe beam, the probe beam comprising the N emitting sub-beams.

3. The detection device according to claim 1, characterized in that, The wavelength division multiplexing (WDM) assembly includes at least a wavelength division multiplexer, which includes N wavelength channels, each corresponding to the wavelength of one of the N reflector beams, and the N detectors each corresponding to the output of one of the N wavelength channels.

4. The detection device according to claim 3, characterized in that, The wavelength division multiplexing (WDM) assembly also includes N filtering elements, the passing wavelengths of which correspond to the wavelengths of the N reflector beams, and the N filtering elements are respectively disposed between the output ends of the N wavelength channels and the N detectors.

5. The detection device according to claim 2, characterized in that, It also includes an optical circulator, which includes at least a first port, a second port and a third port, wherein the first port to the second port forms an optical channel and the second port to the third port forms an optical channel; The first port is connected to the laser generating component, the second port is connected to the transceiver component, and the third port is connected to the wavelength division multiplexing (WDM) component.

6. The detection device according to claim 2, characterized in that, The laser generating component includes at least a single-frequency laser and an optical resonant cavity; The single-frequency laser is used to emit single-frequency laser light. The optical resonant cavity is disposed on the transmission path of the single-frequency laser light and is used to act on the single-frequency laser light to generate M sub-beams. The wavelengths of the M sub-beams are different, and M is a positive integer greater than or equal to N.

7. The detection device according to claim 6, characterized in that, The laser generating component also includes a spectrum shaping component; The spectrum shaping component is used to obtain N sub-beams from the M sub-beams, wherein the wavelengths of any two sub-beams in the N sub-beams are different, and the power difference between any two sub-beams in the N sub-beams is less than or equal to a preset threshold.

8. The detection device according to claim 7, characterized in that, The laser generating component also includes an optical amplifier; The optical amplifier is used to increase the power of each of the N sub-beams by a preset factor to form the N emission sub-beams.

9. The detection device according to claim 2, characterized in that, The adjacent wavelengths of the N transmitting sub-beams are equally spaced.

10. The detection device according to claim 9, characterized in that, The laser generating component is also used to adjust the number of N emitting sub-beams in the probe beam and / or adjust the adjacent wavelength spacing of the N emitting sub-beams.

11. The detection device according to claim 2, characterized in that, The vertical launching assembly includes at least a collimator and a convex lens; The collimator is positioned off-center from the focal point of the convex lens and on the focal plane of the convex lens, for collimating the probe beam onto the convex lens.

12. The detection device according to claim 2, characterized in that, The vertical emission assembly includes at least a collimator and a diffraction grating; The collimator is used to collimate the probe beam and direct it onto the diffraction grating.

13. The detection device according to claim 2, characterized in that, The laser generating component is also used to sequentially and as a whole adjust the wavelengths of the N emitting sub-beams within a preset wavelength range.

14. The detection device according to claim 1, characterized in that, The horizontal emission component includes at least one dispersive optical element disposed on the transmission path of the beam emitted by the vertical emission component, and emits the emission sub-beams of different wavelengths to the target scanning space at different azimuth angles.

15. The detection device according to claim 14, characterized in that, The horizontal emission assembly further includes at least one convex reflector disposed on the transmission path of the reflected beam of the dispersive optical element.

16. The detection device according to any one of claims 1-15, characterized in that, The interval between adjacent wavelengths is greater than the preset wavelength range.

17. A lidar system, characterized in that, It includes at least the detection device as described in any one of claims 1-16.

18. A terminal, characterized in that, It includes at least the detection device as described in any one of claims 1-16, or the lidar system as described in claim 17.

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