WO2023225963A1 - 一种扫描装置、激光雷达和终端 - Google Patents

一种扫描装置、激光雷达和终端 Download PDF

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Publication number
WO2023225963A1
WO2023225963A1 PCT/CN2022/095360 CN2022095360W WO2023225963A1 WO 2023225963 A1 WO2023225963 A1 WO 2023225963A1 CN 2022095360 W CN2022095360 W CN 2022095360W WO 2023225963 A1 WO2023225963 A1 WO 2023225963A1
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Prior art keywords
optical signal
signal
plate layer
scanning device
wave plate
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PCT/CN2022/095360
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English (en)
French (fr)
Inventor
邱孙杰
安凯
郭家兴
韩伟
章浩亮
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华为技术有限公司
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Priority to PCT/CN2022/095360 priority Critical patent/WO2023225963A1/zh
Publication of WO2023225963A1 publication Critical patent/WO2023225963A1/zh

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/481—Constructional features, e.g. arrangements of optical elements

Definitions

  • This application relates to detection technology, and in particular to a scanning device, lidar and terminal.
  • Lidar is a detection device that combines laser technology with photoelectric conversion technology. It detects the position, shape, speed and other characteristic quantities of target objects by emitting laser signals.
  • lidar senses the surrounding environment, it will inevitably encounter high reflectivity or special reflectivity (referred to as angular reflection) targets.
  • high reflectivity referred to as high reflection
  • these high reflectivity (referred to as high reflection) targets or angular reflection targets will produce strong scattered light, and the strong scattered light may affect the real echo signal.
  • the detection device may mistakenly detect ghost images of highly reflected targets or corner-reflected targets.
  • the signal returned by a highly reflective target or an angularly reflective target may drown the echo signal of the real object.
  • Figures 1 and 2 show the working scenes of some detection devices.
  • the optical signal emitted by the transmitting module can reach the detection area through the scanner.
  • the optical signal normally reaches the detection area through the optical element, is reflected by the objects in the detection area, and is received by the receiving module through the scanner.
  • the emitted signal may be reflected by the optical elements, and the reflected signal may be reflected by the scanner and reach the detection area again.
  • a part of the optical signal (such as signal 1) will be reflected by the optical element.
  • the signal reflected by the optical element (such as signal 2) reaches the scanner, it is reflected again by the scanner. in the field of view (such as signal 3).
  • a strong reflected signal (signal 4) may be generated, and the reflected signal passes through the scanner (such as signal 5, signal 6 , shown in the optical path of signal 7) is received by the receiving module. Since the receiving module cannot distinguish these signals that have been reflected to the detection area by multiple scanners, it will mistakenly believe that there is an object in another area, thus forming a highly reflective target. (or corner anti-target) ghost image. As shown in part (c) of Figure 2, the signal returned by the highly reflective target may also reach the receiving module through the scanner, forming an interference signal.
  • Embodiments of the present application provide a scanning device, lidar and terminal, which can reduce the occurrence of ghost image problems and help improve the recognition accuracy of lidar.
  • embodiments of the present application provide a scanning device, including a scanner body, a polarizing plate layer, and a wave plate layer.
  • the scanner body has at least one reflective surface, and the reflective surface of the scanner body is adhered to There is a polarizing plate layer, and a wave plate layer is attached to the polarizing plate layer.
  • the wave plate layer includes one or more wave plates.
  • Wave plate also called phase retardation plate, is made of birefringent materials.
  • the wave plate can cause a phase shift in the two mutually orthogonal polarization components of the optical signal passing through the wave plate, and can be used to adjust the polarization state of the light beam.
  • the wave plate layer can cause an orthogonal component of the passing optical signal to generate a phase shift of (2k+1) ⁇ /2, where k is a natural number.
  • the wave plate layer may include a quarter-wave plate, and the quarter-wave plate can cause the orthogonal component of the passing optical signal to generate a phase shift of ⁇ /2.
  • the wave plate layer may include a quarter wave plate and a half wave plate, and a combination of a quarter wave plate and a half wave plate can generate orthogonal components of the passing optical signal. Phase shift of 3 ⁇ /2.
  • the polarizing plate layer has a polarizing plate or a polarizing beam splitter.
  • a polarizing plate is a kind of optical filter.
  • the transmittance of an optical signal when passing through a polarizing plate is related to the polarization direction of the optical signal.
  • linearly polarized light in a certain direction can pass through, while light with a polarization direction perpendicular to it is blocked (cannot ), light with a polarization direction perpendicular to it will be absorbed or reflected in other directions.
  • the scanning device moves as a whole to form reflective surfaces at various angles.
  • the overall activity includes activities such as swinging or turning.
  • the scanning device of the present application can eliminate the emission signal reflected by the optical element, prevent the signal reflected by the optical element from being reflected to the detection area by the scanning device again, and can reduce the generation of ghost images and help improve detection devices (such as laser radar, etc.) ) recognition accuracy.
  • the stability and accuracy of the optical path and optical axis can directly affect the use of polarizers, wave plates and other devices.
  • the wave plate layer and polarizing plate layer in this application are bonded to the reflective surface, which can reduce the impact of vibration on optical elements, improve the stability of the scanning device, and help improve the detection performance of the detection device.
  • the polarizing plate layer is bonded to the reflective surface of the scanner body by gluing. Pasting the polarizer layer on the reflective surface through gluing can enhance the connection stability between optical elements, reduce the impact of vibration on the optical elements, improve the stability of the scanning device, and help improve the detection performance of the detection device.
  • gluing also known as bonding, bonding, cementing
  • Adhesive is a natural or synthetic, organic or inorganic substance that can connect two or more parts or materials together through interface adhesion and cohesion. It is also called an adhesive. It is also referred to as glue in daily life.
  • the gluing method can be achieved through optically clear adhesive (optically clear adhesive, OCA).
  • optically clear adhesive optically clear adhesive, OCA
  • the gluing method includes the following method: applying pressure to make the surfaces of two optical parts adsorb together.
  • the surfaces of the two optical parts that fit together are usually clean, smooth, and consistent.
  • this method is also called photo glue.
  • Gluing with optical glue can make the plane between the polarizer layer and the reflective surface flatter, improve light transmittance and reduce energy consumption.
  • the wave plate layer is bonded to the polarizing plate layer by gluing. Pasting the wave plate on the polarizing plate layer through gluing can enhance the connection stability between optical elements, reduce the impact of vibration on the optical elements, improve the stability of the scanning device, and help improve the detection performance of lidar.
  • Optional gluing methods include connecting through adhesive, connecting through optical glue, etc.
  • the incident light signal is incident on the wave plate layer and the polarizing plate layer in sequence, and is reflected by the reflective surface and then emitted from the polarizing plate layer and the wave plate layer in sequence. , get the outgoing signal.
  • each reflective surface starting from the scanner body, from the inside to the outside are the scanner body, the polarizing plate layer, and the wave plate layer.
  • the polarizer layer is used to block a specularly reflected light signal corresponding to the outgoing signal, and the specularly reflected light signal is obtained after specular reflection of the outgoing signal. light signal.
  • the diffusely reflected light is natural light.
  • the specularly reflected light is polarized light. Since the polarizer layer can block optical signals whose polarization direction is perpendicular to the polarization direction of the polarizer, when the specular reflection signal of the outgoing signal passes through the wave plate layer, its polarization direction is perpendicular to the polarization direction of the polarizer layer, so the polarizer layer It can block the specular reflected light signal corresponding to the outgoing signal.
  • the scanning device of the present application can block the light signal reflected by the optical element, thereby preventing the signal returned by the optical element from being irradiated into the market again. Reduce the generation of ghost images and weaken the intensity of interference signals, which helps improve the recognition accuracy of detection devices (such as lidar, etc.).
  • the polarizer layer is used to block the first reflected light signal and transmit the second reflected light signal, wherein the first reflected light signal is reflected by the window.
  • the outgoing signal is obtained, and the second reflected light signal is obtained by reflecting the outgoing signal from an object within the field of view of the scanning device.
  • the outgoing signal is reflected by the window and reaches the scanning device again.
  • This application can block the signal returned from the window, thereby preventing the signal returned from the window from being irradiated into the detection area again, which can reduce the generation of ghost images, weaken the intensity of the interference signal, and help improve signal effectiveness.
  • the first optical signal from the laser emitter passes through the wave plate layer and the polarizing plate layer in sequence to obtain a second optical signal, and the second optical signal and the The polarization direction of the polarizer layer is parallel;
  • the second optical signal After the second optical signal is reflected by the at least one reflective surface, it passes through the polarizing layer to obtain a third optical signal.
  • the polarization direction of the third optical signal is parallel to the polarization direction of the polarizer layer;
  • the third optical signal passes through the wave plate layer to obtain a fourth optical signal, and the polarization direction of the fourth optical signal is circular polarization;
  • the return signal corresponding to the fourth optical signal includes a fifth optical signal and a sixth optical signal, wherein the fifth optical signal is an optical signal obtained by mirror reflection of the fourth optical signal, and the sixth optical signal is an optical signal obtained by diffuse reflection of the fourth optical signal, and the polarization direction of the fifth optical signal is circular polarization;
  • the fifth optical signal is incident on the wave plate layer and converted into a seventh optical signal by the wave plate layer.
  • the seventh optical signal is incident on the polarizing plate layer.
  • the seventh optical signal is converted by the polarizing plate. layer blocking, the polarization direction of the seventh optical signal is perpendicular to the polarization direction of the polarizer layer;
  • the sixth optical signal is incident on the wave plate layer and is incident on the polarizing plate layer through the wave plate layer.
  • the optical signal whose polarization direction is perpendicular to the polarizing direction of the polarizing plate layer in the sixth optical signal is The polarizing plate layer blocks the optical signal whose polarization direction is parallel to the polarizing direction of the polarizing plate layer in the sixth optical signal and passes through the polarizing plate layer to obtain an eighth optical signal;
  • the eighth optical signal is reflected by the at least one reflective surface, passes through the polarizing layer and the wave plate layer in sequence, and is provided to the receiver.
  • the fifth optical signal is obtained by reflecting the outgoing signal through a window
  • the sixth optical signal is obtained by reflecting the outgoing signal from an object within the field of view of the scanning device. get.
  • the scanner body includes a first part and a second part, the first part and the second part are arranged along the direction of the rotation axis or the pendulum axis, and the polarizing plate The layer is attached to the reflective surface of the first part of the scanner body, and the polarizer layer is not provided on the reflective surface of the second part of the scanner body.
  • the scanner body has multiple parts, a first part for transmitting signals and a second part for receiving signals. Since the polarizer layer is provided in the first part, the specular reflected light signal can be blocked. Since the second part does not have a polarizer layer, it can avoid weakening the energy of the returned signal in the detection area, thereby improving the light transmittance, reducing energy consumption, and helping to improve signal effectiveness.
  • the first optical signal from the laser emitter passes through the wave plate layer and the polarizing plate layer in sequence to obtain a second optical signal, and the second optical signal and the The polarization direction of the polarizer layer is parallel;
  • a third optical signal is obtained through the polarizing layer, and the polarization direction of the third optical signal is parallel to the polarization direction of the polarizer layer;
  • the third optical signal passes through the wave plate layer to obtain a fourth optical signal, and the polarization direction of the fourth optical signal is circular polarization;
  • the return signal corresponding to the fourth optical signal includes a ninth optical signal and a tenth optical signal, wherein the ninth optical signal is an optical signal obtained by mirror reflection of the fourth optical signal, and the tenth optical signal It is an optical signal obtained by diffuse reflection of the fourth optical signal, and the polarization direction of the ninth optical signal is circular polarization;
  • the ninth optical signal is incident on the wave plate layer and converted into an eleventh optical signal by the wave plate layer.
  • the eleventh optical signal is incident on the polarizing plate layer, and the eleventh optical signal is converted by the wave plate layer.
  • the polarizer layer blocks, and the polarization direction of the eleventh optical signal is perpendicular to the polarization direction of the polarizer layer;
  • the tenth optical signal irradiates the reflective surface of the second part of the scanner body and is reflected by the reflective surface of the second part of the scanner body to obtain a twelfth optical signal.
  • the twelfth optical signal is provided to the receiver.
  • the ninth optical signal is obtained by reflecting the outgoing signal through a window
  • the tenth optical signal is obtained by reflecting the outgoing signal from an object within the field of view of the scanning device.
  • the wave plate layer includes a quarter wave plate.
  • the wave plate layer includes a quarter wave plate and a half wave plate.
  • the combination of "1/2 wave plate + 1/4 wave plate” has an achromatic effect. Even under high and low temperature conditions and when the wavelength drifts, ghost images can be eliminated, which helps to improve detection. Recognition accuracy of devices (such as lidar, etc.).
  • the reflective surface includes a base, and the base is metal.
  • the reflective surface includes a substrate and a reflective coating, and the reflective coating is attached to the surface of the substrate.
  • the material of the substrate is glass or crystal.
  • the difference between the first angle and the second angle is less than or equal to the first threshold, and the first angle is the difference between the polarization direction of the polarizer layer and the wave plate.
  • the angle between the optical axis directions of the layers, and the second angle is 45°.
  • the wave plate has a fast axis and a slow axis, both are perpendicular to the surface and the direction of beam propagation, and the fast axis and slow axis are perpendicular to each other.
  • the incident light signal is linearly polarized light
  • the angle between the incident light signal and the optical axis of the wave plate layer is 45°.
  • the outgoing signal is circularly polarized light.
  • linearly polarized light can be obtained after circularly polarized light passes through the wave plate layer. If the angle between the incident light signal and the optical axis deviates from 45°, then the line sheet light will obtain elliptically polarized light after passing through the wave plate layer.
  • the blocking effect of the polarizer layer on specularly reflected light signals can be controlled, thereby better meeting the needs of users.
  • the polarizer layer can have a better blocking effect on specularly reflected light signals, and can reduce the generation of ghost images.
  • an anti-reflection film is present on the first surface of the wave plate layer, and the first surface is a surface away from the scanner body.
  • the transmittance of optical signals in the wave plate layer can be increased, energy consumption can be reduced, and signal effectiveness can be improved.
  • inventions of the present application provide a detection device.
  • the detection device includes a scanning module, a transmitting module and a receiving module.
  • the transmitting module is used to generate a transmitting signal.
  • the receiving module is used to detect an optical signal.
  • the scanning module includes the scanning device described in any one of the first aspects.
  • the detection device further includes a window, and the light signal reflected by the window is blocked by the polarizing plate layer in the scanning device, from within the field of view of the detection device.
  • the optical signal reflected back from the object is provided to the receiving module by the scanning device.
  • embodiments of the present application provide a terminal, which includes the scanning device described in any one of the first aspects, or the terminal includes the detection device described in any one of the second aspects.
  • the terminal is a vehicle, drone or robot.
  • Figure 1 is a schematic diagram of the working scene of a detection device
  • Figure 2 is a schematic diagram of the working scene of a detection device
  • Figure 3 is a schematic structural diagram of a detection device provided by an embodiment of the present application.
  • Figure 4 is a schematic structural diagram of a scanning device provided by an embodiment of the present application.
  • Figure 5 is a schematic diagram of an optical path through a scanning device provided by an embodiment of the present application.
  • Figure 6 is a schematic diagram of the optical path of a laser signal passing through a scanning device according to an embodiment of the present application
  • Figure 7 is a schematic diagram of an emission light path provided by an embodiment of the present application.
  • Figure 8 is a schematic diagram of a receiving optical path provided by an embodiment of the present application.
  • Figure 9 is a schematic diagram of another receiving light path provided by an embodiment of the present application.
  • Figure 10 is a schematic diagram of a usage scenario of a scanning device provided by an embodiment of the present application.
  • Figure 11 is a schematic structural diagram of another possible scanning device provided by an embodiment of the present application.
  • Figure 12 is a schematic diagram of a usage scenario of another scanning device provided by an embodiment of the present application.
  • Figure 13 is a schematic structural diagram of yet another scanning device provided by an embodiment of the present application.
  • Figure 14 is a schematic structural diagram of yet another scanning device provided by an embodiment of the present application.
  • Figure 15 is a schematic structural diagram of yet another scanning device provided by an embodiment of the present application.
  • Figure 16 is a schematic structural diagram of yet another scanning device provided by an embodiment of the present application.
  • Figure 17 is a schematic diagram of the layer connection method of a scanning device provided by an embodiment of the present application.
  • Figure 18 is a schematic diagram of another layer connection method of a scanning device provided by an embodiment of the present application.
  • Figure 19A is a schematic diagram of another layer connection method of a scanning device provided by an embodiment of the present application.
  • Figure 19B is a schematic diagram of another layer connection method of a scanning device provided by an embodiment of the present application.
  • Figure 20A is a schematic structural diagram of another scanning device provided by an embodiment of the present application.
  • Figure 20B is a schematic structural diagram of another scanning device provided by an embodiment of the present application.
  • Figure 21 is a schematic structural diagram of another scanning device provided by an embodiment of the present application.
  • Figure 22 is a schematic structural diagram of yet another scanning device provided by an embodiment of the present application.
  • Figure 23 is a schematic structural diagram of another scanning device provided by an embodiment of the present application.
  • Figure 24 is a schematic structural diagram of yet another scanning device provided by an embodiment of the present application.
  • Figure 25 is a schematic structural diagram of a terminal provided by an embodiment of the present application.
  • the detection device mentioned in the embodiments of the present application may be a lidar, or may be other light detection devices, such as a fusion detection device (for example, a detection device integrating a radar detector and an image sensor). Its working principle is to detect the corresponding detection area by emitting light signals and receiving returned light signals.
  • a fusion detection device for example, a detection device integrating a radar detector and an image sensor. Its working principle is to detect the corresponding detection area by emitting light signals and receiving returned light signals.
  • the detection device in the embodiment of the present application can be used in various fields such as intelligent driving, intelligent transportation, intelligent manufacturing, environmental detection, surveying and mapping, and drones, and can complete target detection, distance measurement, speed measurement, target tracking, imaging recognition, etc. one or more functions.
  • the detection device in the embodiment of the present application can be applied to vehicle-mounted detection devices (such as vehicle-mounted radar), roadside detection devices (such as intersection radar), etc., and can also be applied to other detection devices, such as those installed on drones, robots, tracks, etc. Detection devices on cars, bicycles, traffic lights, speed measuring devices or base stations, etc. This application does not limit the installation location of the detection device.
  • vehicle-mounted detection devices such as vehicle-mounted radar
  • roadside detection devices such as intersection radar
  • other detection devices such as those installed on drones, robots, tracks, etc. Detection devices on cars, bicycles, traffic lights, speed measuring devices or base stations, etc. This application does not limit the installation location of the detection device.
  • the scanning process relies on a scanning device, where the scanning device can be moved by rotation, swing, electrical control, etc.
  • mechanical scanning refers to scanning the field of view through an inertial scanning device.
  • 2D mechanical scanning can be achieved through a 2D scanning device, or through a combination of two 1D dimensional scans.
  • Wave plate also called phase retardation plate, is made of birefringent materials.
  • the wave plate can cause a phase shift in the two mutually orthogonal polarization components of the optical signal passing through the wave plate, and can be used to adjust the polarization state of the light beam.
  • the wave plate has a fast axis and a slow axis, both perpendicular to the surface and the direction of beam propagation, and the fast axis and slow axis are perpendicular to each other.
  • the incident light signal is linearly polarized light
  • the angle between the incident light signal and the optical axis of the wave plate layer is 45°.
  • the outgoing signal is circularly polarized light.
  • linearly polarized light can be obtained after circularly polarized light passes through the wave plate layer. If the angle between the incident light signal and the optical axis deviates from 45°, then the line sheet light will obtain elliptically polarized light after passing through the wave plate layer.
  • Polarization means that the vibration direction of the electric vector of light has certain rules. Polarization is an inherent property of light, and polarization state is a parameter of light. The polarization state can be divided into: linear polarization, elliptical polarization (including circular polarization).
  • non-polarized light such as natural light
  • a polarizing plate is a kind of optical filter.
  • the transmittance of an optical signal when passing through a polarizing plate is related to the polarization direction of the optical signal.
  • linearly polarized light in a certain direction can pass through, while light with a polarization direction perpendicular to it is blocked (cannot ), light with a polarization direction perpendicular to it will be absorbed or reflected in other directions.
  • P light P-polarized light
  • S light S-polarized light
  • Gluing also known as bonding, bonding, cementing refers to the technology of joining the surfaces of homogeneous or heterogeneous objects together with adhesives.
  • Adhesive is a natural or synthetic, organic or inorganic substance that can connect two or more parts or materials together through interface adhesion and cohesion. It is also called an adhesive. It is also referred to as glue in daily life.
  • gluing can be achieved using optically clear adhesive (OCA).
  • OCA optically clear adhesive
  • the gluing method includes the following method: applying pressure to make the surfaces of two optical parts adsorb together.
  • the surfaces of the two optical parts that fit together are usually clean, smooth, and consistent.
  • this method is also called optical glue.
  • the field of view refers to the range that can be detected by the detection device, also called the field of view.
  • LOS line of sight
  • This sight area can be understood as the field of view.
  • the physical world that can be detected by the detection device is called a detection area.
  • the physical world referred to by the detection area refers to the physical world located outside the detection device, where the outside may be outside the outermost component of the detection device, for example, outside the view window of the lidar.
  • the architecture of the detection device 30 provided by the embodiment of the present application is shown in Figure 3, including a transmitting module 301 and a scanning module 302. in:
  • the transmitting module 301 includes a light source, and the light source is used to generate optical signals.
  • the light source may include a light emitting element (such as a laser emitter, etc.) and may generate light signals of infrared light, ultraviolet light, visible light or other wavelengths.
  • the emission module 301 may include one or more of the following light-emitting elements: lasers such as semiconductor lasers, fiber lasers, or gas lasers.
  • semiconductor lasers can specifically include laser diodes (LDs), vertical cavity surface emitting lasers (VCSELs), edge-emitting lasers (edge-emitting lasers, EELs), distributed feedback lasers (distributed feedback LD, DFB-LD), distributed brag reflection laser (distributed brag reflection LD, DBR-LD), grating coupled sampling reflection laser (Grating coupled sampling reflection LD, GCSR-LD), micro optical electromechanical system laser (micro optical electromechanical system LD, MOEMS-LD) and other light-emitting components.
  • LDs laser diodes
  • VCSELs vertical cavity surface emitting lasers
  • EELs edge-emitting lasers
  • distributed feedback lasers distributed feedback LD, DFB-LD
  • distributed brag reflection laser distributed brag reflection LD, DBR-LD
  • grating coupled sampling reflection laser grating
  • the scanning module 302 is used to change the propagation direction of light.
  • the scanning module 302 can change the propagation direction of the optical signal from the light source, and/or the scanning module 302 can change the propagation direction of the optical signal from the object within the field of view.
  • the scanning module may include at least one reflective surface. By changing the angle of the reflective surface, the light signal from the light source can be irradiated to different positions in the field of view, thereby completing the detection of the detection area.
  • the detection device 30 may also include a receiving module 303.
  • the receiving module 303 is used to receive optical signals. Further, the receiving module can obtain the electrical signal based on the optical signal.
  • the electrical signal can be output as detection data, or the electrical signal can be processed to obtain detection data and then output.
  • the receiving module 303 may include one or more detection elements.
  • the receiving module may include one or more of the following detection elements: single-photon avalanche diode (SPAD), silicon photomultiplier (SiPM), semiconductor avalanche photodiode (avalanche photo detector) , APD), a multi-pixel photon counter (MPPC), or an electron multiplying charge-coupled device (EMCCD) and other detection elements.
  • detection elements single-photon avalanche diode (SPAD), silicon photomultiplier (SiPM), semiconductor avalanche photodiode (avalanche photo detector) , APD), a multi-pixel photon counter (MPPC), or an electron multiplying charge-coupled device (EMCCD) and other detection elements.
  • the multiple detection elements may be arranged in an array, for example, in the form of a line array or an area array (optional with an addressing and reading function).
  • the receiving module may include array detection elements with specifications such as 1 ⁇ 2 array, 2 ⁇ 3 array, or 3 ⁇ 3 array. This application does not limit the number of rows and columns of the array arrangement.
  • the detection device 30 may also include a control module 304, which is used to control one or more of the transmitting module 301, the scanning module 302, or the receiving module 303.
  • a control module 304 which is used to control one or more of the transmitting module 301, the scanning module 302, or the receiving module 303.
  • the detection device 30 may also include one or more optical elements, such as windows, shaping devices (such as collimation devices, or optical path shaping devices, etc.), reflectors, lenses, polarizers, filters, Or even light film, etc.
  • optical elements such as windows, shaping devices (such as collimation devices, or optical path shaping devices, etc.), reflectors, lenses, polarizers, filters, Or even light film, etc.
  • the number, placement position, placement order, size, etc. of the optical elements in the detection device there are no limitations on the number, placement position, placement order, size, etc. of the optical elements in the detection device. It should be understood that the number and installation positions of transmitting modules, receiving modules, optical elements, etc. in the embodiment of the present application are not limited.
  • Figure 3 is only a possible situation shown for convenience of description and is not used as a guide to the detection device 30. limited.
  • the optical signal returned by the window or optical element may be reflected twice by the scanning device, these secondary reflected signals are likely to illuminate the detection area.
  • the secondary reflected signal is detected
  • highly reflective targets or angular reflective targets in the area are reflected back to the detection device, they may affect the real echo signal.
  • the detection device may mistakenly detect ghost images of highly reflected targets or corner-reflected targets.
  • the signal returned by a highly reflective target or an angularly reflective target may drown the echo signal of the real object.
  • embodiments of the present application provide a scanning device, lidar and terminal, which can reduce the generation of ghost images, weaken the intensity of interference signals, and help improve the identification accuracy of detection devices (such as lidar, etc.).
  • the embodiments of the present application are particularly suitable for scanning laser radar.
  • the scanning device provided by the embodiment of the present application can be applied to the aforementioned detection device 30 .
  • the scanning device can replace the scanning module 302 , or the scanning device can be included in the scanning module 302 .
  • FIG. 4 is a schematic structural diagram of a scanning device 40 provided by an embodiment of the present application.
  • the scanning device 40 includes a scanner body, a polarizing plate layer, and a wave plate layer.
  • the scanner body has at least one reflective surface
  • a polarizing plate layer is attached to the reflecting surface of the scanner body
  • a wave plate layer is attached to the polarizing plate layer.
  • the incident optical signal reaches the scanning device, the optical signal is incident on the wave plate layer and the polarizing plate layer in sequence, is reflected by the reflective surface, and then emerges from the polarizing plate layer and the wave plate layer in sequence.
  • the emitted signal is circularly polarized light.
  • the wave plate layer can cause an orthogonal component of the passing optical signal to produce a phase shift of (2k+1) ⁇ /2, where k is a natural number.
  • the specular reflected light signal obtained after the outgoing signal undergoes specular reflection is also circularly polarized.
  • an optical signal whose polarization direction is perpendicular to the polarization direction of the polarizing plate layer is obtained. Since the light whose polarization direction is perpendicular to the polarization direction of the polarizer layer will be blocked (cannot pass through), the blocking here may be absorption or reflection in other directions.
  • the scanning device of the present application can eliminate the emission signal reflected by the optical element, prevent the signal reflected by the optical element from being reflected into the field of view by the scanning device again, reduce the generation of ghost images, weaken the intensity of the interference signal, and help Improve the recognition accuracy of lidar.
  • the wave plate layer and polarizing plate layer in this application are bonded to the reflective surface, which can reduce the impact of vibration on optical elements, improve the stability of the scanning device, and help improve the detection performance of the detection device.
  • Figure 6 shows a schematic diagram of a possible optical path of a laser signal passing through a scanning device according to an embodiment of the present application.
  • signal (1) is the optical signal from the light source. After signal (1) passes through the wave plate, signal (2) is obtained. Signal (2) is incident on the polarizing plate layer, and the signal emitted from the polarizing plate layer is signal (3). Since only optical signals with polarization directions parallel to the polarizer layer can pass through, the polarization direction of signal (3) is parallel to the polarization direction of the polarizer layer, that is, signal (3) is P light. In order to facilitate the distinction, signal (3) is recorded as P light_1. The signal (3) passes through the reflective surface of the scanner body and is reflected to obtain the signal (4), which is recorded as P light_2.
  • the signal (4) passes through the polarizer layer again to obtain the signal (5).
  • the polarization direction of the signal (5) is parallel to the polarization direction of the polarizer layer, which is recorded as P light_3.
  • Signal (5) is incident on the wave plate layer, and the outgoing signal is signal (6). Since the outgoing light after linearly polarized light is incident on the wave plate layer is circularly polarized (considering errors, it may also be elliptically polarized), so signal (6) is circularly polarized. .
  • the optical signal from the transmitting module After the optical signal from the transmitting module is emitted from the scanning device shown in Figure 5 (for convenience of description below, the optical signal from the transmitting module and emitted from the scanning device is referred to as the emitting signal), it can propagate into the field of view, but during propagation The process may pass through some optical components in the detection device, such as windows. When passing through the optical element, most of the light signal passes through the optical element and irradiates into the detection area, but part of the light signal may be reflected by the optical element.
  • Figure 7 shows a schematic diagram of a transmission light path provided by an embodiment of the present application. Part of the outgoing signal can illuminate objects in the detection area. Since the surfaces of objects in the real world are usually rough, diffuse reflection occurs when the light signal illuminates the object. Part of the outgoing signal may be reflected on the optical element (such as a window, etc.). Since the surface of the optical element is usually smooth, the reflection phenomenon on the surface of the optical element is specular reflection.
  • the polarization state of the reflected signal obtained in diffuse reflection and specular reflection phenomena is different.
  • the specific performance is as follows: when polarized light is reflected specularly, the reflected optical signal is still polarized light; when polarized light is diffusely reflected, the polarization direction of the reflected optical signal will change. In some scenes, when polarized light is reflected by specular surfaces, the reflected light signal is polarized light, and the polarization direction may not change (or may change slightly); when polarized light is diffusely reflected, it will become natural light.
  • the scanning device can block the outgoing signal reflected by the optical element.
  • the polarized light signal is still a polarized light signal after specular reflection. Therefore, when the outgoing signal is circularly polarized light, the specular reflected light signal of the outgoing signal is still circularly polarized light.
  • the wave plate layer can convert the circularly polarized light into linearly polarized light, and the polarization direction of the linearly polarized light is perpendicular to the polarization direction of the polarizing plate layer, that is, S light.
  • the scanning device provided by the embodiment of the present application can prevent the signal reflected by the optical element from being reflected into the field of view by the scanning device again, reducing the generation of ghost images, weakening the intensity of the interference signal, and helping to improve the recognition accuracy of the lidar. .
  • the optical signal that originally passed through the polarizer layer reaches the polarizer layer again after being reflected by the reflective surface, the polarization direction of the optical signal that originally passed through the polarizer layer may have changed, so part of the optical signal may be Polarizer layer blocks.
  • the above process can be expressed as: signal (5) and signal (4) are not exactly the same.
  • the signal (3) emerges from the polarizing plate layer at the first moment, and the polarization direction of the signal (3) is parallel to the polarizing plate; when the signal (4) reaches the polarizing plate layer at the second moment, its polarization direction may not be the same. Then completely parallel to the polarization direction of the polarizer layer. Therefore, the optical signal in signal (4) whose polarization direction is parallel to the polarizer layer passes through the polarizer layer to form signal (5); and part of the optical signal in signal (4) is blocked by the polarizer layer.
  • the polarizer layer also moves together. However, after the polarizer layer moves, part of the light signal originally parallel to the polarization direction of the polarizer layer may be blocked by the polarizer layer.
  • the polarization direction of the signal (4) may no longer be completely parallel to the polarization direction of the polarizer layer. Therefore, the optical signal in signal (4) whose polarization direction is parallel to the polarizer layer passes through the polarizer layer to form signal (5); and part of the optical signal in signal (4) is blocked by the polarizer layer.
  • the polarizing plate layer since the polarizing plate layer is attached to the main body of the scanner, the polarizing plate layer and the main body of the scanner move in unison, which can reduce the relative position difference between the polarizing plate layer and the reflective surface, and also shorten the length of the emitted light.
  • the propagation time for the signal to reach the polarizer layer for the second time can reduce the loss of the optical signal and improve the signal effectiveness.
  • the receiving light path includes both the optical signal reflected by the object in the detection area (hereinafter referred to as the echo signal of the real object) and the reflected signal from the optical element.
  • FIG 8 is a schematic diagram of a receiving optical path provided by an embodiment of the present application, in which the optical signal of the incident wave plate layer, that is, signal (7), is the specular reflection light of the outgoing optical signal (that is, signal (6)). signal, so the polarization direction of signal (7) is circular polarization (considering errors, it may also be elliptical polarization), which is the same as signal (6).
  • the emitted light signal is the signal (8)
  • the signal (8) is linearly polarized light
  • the polarization direction of the signal (8) is perpendicular to the polarizing plate layer.
  • the signal (8) Since the optical signal whose polarization direction is perpendicular to the polarization direction of the polarizer is blocked, the signal (8) is blocked by the polarizer layer. Therefore, the specular reflected light signal of the outgoing light signal cannot be re-reflected into the detection area and will not cause interference to the echo signal of the real object.
  • the echo signal of the real object can be provided to the receiving module through the scanning device.
  • the real echo signal also passes through the polarizing plate layer, the wave plate layer and the reflecting surface. After being reflected by the reflecting surface, it passes through the polarizing plate layer and the wave plate layer and is provided to the receiving module.
  • the diffuse reflection signal of the emitted light signal is natural light. Natural light is still natural light after passing through the wave plate layer, and natural light is still natural light after passing through the wave plate.
  • the emitted light signal is S light. The S light is reflected by the reflective surface of the scanner body, and then passes through the polarizing layer again to enter the wave plate layer.
  • the wave plate layer converts the S light into circularly polarized light. Furthermore, the circularly polarized light can continue to propagate in the direction of the receiving module.
  • Signal (9) is the optical signal obtained by reflecting the outgoing light signal from the object in the detection area, that is, the echo signal of the real object.
  • Signal (9) passes through the wave plate layer to obtain signal (10).
  • signal 10 After signal 10 is incident on the polarizing plate layer, the optical signal whose polarization direction is parallel to the polarizing plate layer is transmitted, and signal (11) is obtained.
  • the polarization direction of signal (11) is parallel to The polarization direction of the polarizer layer is marked as: P light_4 for easy identification.
  • Signal (11) is reflected on the reflective surface to obtain signal (12), which is recorded as: P light_5.
  • the signal (12) passes through the polarizer layer again, and the light signal whose polarization direction is parallel to the polarizer layer is transmitted, and the signal (13) is obtained, which is recorded as: P light_6. After the signal 13 passes through the wave plate layer, the signal (14) is obtained. Since the signal (13) is linearly polarized light, and the linearly polarized light becomes circularly polarized light after passing through the waveplate layer, the signal (14) is circularly polarized light. Signal (14) is provided to the receiving module.
  • the signal (11), the signal (12), and the signal (13) are P lights at different times, and their polarization directions or energy levels may be different or not exactly the same.
  • signal (4) and signal (5) are P lights at different times, and their polarization directions or energy levels may be different or not exactly the same.
  • Figure 10 shows a schematic diagram of a possible usage scenario of the scanning device, taking the optical element as a window as an example. It can be seen that the outgoing light signal reflected by the window is blocked when passing through the polarizing plate layer; the echo signal returned by the object in the detection area passes through the wave plate layer, polarizing plate layer, reflective surface, and polarization layer of the scanning device in sequence. After the plate layer and wave plate layer, they are provided to the receiving module.
  • the echo signal of the real object does not pass through the polarizer layer.
  • FIG. 11 shows a schematic structural diagram of yet another possible scanning device provided by an embodiment of the present application, in which the scanner body has a reflective surface.
  • the main body of the scanner includes a first part and a second part, the first part is provided with a polarizing film layer, and the second part is not provided with a polarizing film layer.
  • Figure 12 shows a schematic diagram of another possible usage scenario of a scanning device provided by an embodiment of the present application.
  • the transmitted signal reaches the detection area through the first part of reflection, and the return signal from the detection area is provided to the receiving module after being reflected by the second part.
  • the signal reflected back by the optical element can be irradiated into the wave plate layer and the polarizing plate layer provided on the first part and blocked by the polarizing plate layer.
  • the reflected back by the optical element can be irradiated into the wave plate layer and the polarizing plate layer provided on the first part and blocked by the polarizing plate layer.
  • FIG. 11 and FIG. 12 are described using an example in which the polarizing plate layer and the wave plate layer are not provided in the second part.
  • a wave plate layer may be provided in the part where the polarizing plate layer is not provided, or the wave plate layer may not be provided, or part of the wave plate layer may be provided.
  • Figure 13 shows a schematic structural diagram of yet another possible scanning device provided by an embodiment of the present application.
  • the scanner body includes a first part and a second part.
  • the first part is provided with a polarizing plate layer and a wave plate layer
  • the second part is not provided with a polarizing plate layer, but is provided with a wave plate layer.
  • the transmitted signal When transmitting a signal, the transmitted signal reaches the detection area through the first part of reflection (passing through the reflective surface, polarizing plate layer, and wave plate layer); when receiving the return signal, the return signal from the detection area passes through the second part of reflection (passing through the reflecting surface, polarizing plate layer, and wave plate layer).
  • Wave plate layer provided to the receiving module. Further, the signal reflected back by the optical element can be irradiated into the wave plate layer and the polarizing plate layer provided on the first part and blocked by the polarizing plate layer.
  • the movable axis may be called a rotating axis, a swing axis, etc.
  • the embodiments of the present application are collectively called the movable axis.
  • Figure 14 is a schematic structural diagram of yet another possible scanning device provided by an embodiment of the present application, in which the first part and the second part of the scanner body are distributed along the direction of the movable axis of the scanning device, where, The polarizing plate layer is disposed on the first part of the scanner body, and the polarizing plate layer is not disposed on the second part of the scanner body.
  • Embodiments of the present application also provide a scanning device including multiple reflective surfaces, such as 2 reflective surfaces, 3 reflective surfaces, 4 reflective surfaces or more.
  • Surface scanning device In scanning devices containing multiple reflective surfaces.
  • the structure on each reflective surface is the same as or similar to the hierarchical structure of one reflective surface described in the embodiments of this application.
  • Figure 15 is a schematic structural diagram of another possible scanning device provided by an embodiment of the present application.
  • the scanner body of the scanning device includes four reflective surfaces, and a polarizing layer is provided on each reflective surface.
  • a wave plate layer is provided above the plate layer.
  • the scanning device can perform activities as a whole, such as rotating, swinging, etc., to form different light signal emission angles (that is, the pointing angle of the light spot in space), and receive return signals at this angle, thereby realizing scanning of the detection area.
  • FIG. 16 shows a schematic structural diagram of another possible scanning device according to the embodiment of the present application.
  • the scanner body of the scanning device may include a first part and a second part, wherein the first part is provided on the reflective surface of the scanner body.
  • Polarizing plate layer and wave plate layer, the second part does not have a polarizing plate layer on the reflective surface of the scanner body.
  • Figure 16 also shows the scene of the scanning device in the process of sending and receiving light signals.
  • the transmitted signal is reflected by the first part and reaches the detection area (passing through the reflective surface, polarizing plate layer, and wave plate layer);
  • the return signal from the detection area is reflected by the second part of the reflective surface, providing to the receiving module.
  • a wave plate layer can be provided on the second part.
  • the signal reflected back by the optical element can be irradiated into the wave plate layer and the polarizing plate layer provided on the first part and blocked by the polarizing plate layer.
  • Figure 8, Figure 10, and Figure 12. which will not be described again here.
  • the scanning device includes multiple layers.
  • the connection methods between multiple layers are gluing, snapping, and fixing of connectors.
  • the following is an example of possible connections between several levels:
  • Gluing refers to the technique of joining the surfaces of homogeneous or heterogeneous objects together with adhesives.
  • Figure 17 shows a schematic diagram of the layer connection method of a possible scanning device provided by this application.
  • the polarizing plate layer is bonded to the reflective surface of the scanner body, and/or the wave plate layer is bonded to the polarizing plate layer.
  • the adhesive may include optically clear adhesive (optically clear adhesive, OCA), etc.
  • this method is also called photo glue.
  • Gluing with optical glue can make the plane between the polarizer layer and the reflective surface flatter, improve light transmittance and reduce energy consumption.
  • the two layers are bonded by intermolecular forces.
  • FIG. 18 is a schematic diagram of another possible layer connection method of a scanning device provided by an embodiment of the present application.
  • the surface of the wave plate layer close to the polarizing plate layer has an uneven area.
  • the surface of the polarizing plate layer close to the wave plate layer also has an uneven area.
  • These two uneven areas can form an interlocking area, so that they are stuck in contact with each other, and the wave plate layer is attached to the polarizing plate layer.
  • the polarizer layer and the layer below it can also be attached by snapping.
  • the adhesive in the transmitting and receiving light paths can be prevented from affecting the propagation direction and transmittance of the optical signal, reducing energy consumption and improving the stability of the scanning device, which helps to improve the detection performance of the detection device.
  • the bite area can be set in an area outside the transmitting light path and the receiving light path, thereby avoiding the energy loss of the optical signal caused by the concave and convex interface in the bite area, and helping to improve the recognition accuracy of the radar.
  • FIGS. 19A and 19B are schematic diagrams of some possible layer connection methods of the scanning device provided by embodiments of the present application.
  • Figure 19A by arranging a connector on the left side of the scanning device, the wave plate layer and the polarization layer can be connected through the connector.
  • the multiple layers can be hooped so that the wave plate layer and the polarizing plate layer are in contact with each other, and/or the polarizing plate layer and the reflective surface are in contact with each other.
  • the adhesive in the transmitting and receiving light paths can be prevented from affecting the propagation direction and transmittance of the optical signal, reducing energy consumption and improving the stability of the scanning device, which helps to improve the detection performance of the detection device.
  • the bite area can be set in an area outside the transmitting light path and the receiving light path, thereby further reducing the energy loss of the optical signal.
  • connection methods between different layers may be different.
  • the polarizing plate layer can be connected to the scanner body through a connector, and the wave plate layer and the polarizing plate layer are connected using glue.
  • the combined connection methods no examples are given here.
  • the above-mentioned polarizing plate layer includes a polarizing plate, and the number of polarizing plates may be one or more.
  • the functions or materials of the multiple polarizing plates may be the same or different.
  • the wave plate layer includes a wave plate, and the number of wave plates may be one or more.
  • the wave plate layer may contain a quarter wave plate.
  • the functions or materials of the multiple wave plates may be the same or different.
  • the above wave plate layer may include a quarter wave plate and a half wave plate.
  • the combination of "1/2 wave plate + 1/4 wave plate" has an achromatic effect, and ghost images can be eliminated even under high temperature (or low temperature) conditions and when the wavelength of the optical signal is shifted. are eliminated, helping to improve the recognition accuracy of lidar.
  • FIG. 20A and FIG. 20B are schematic structural diagrams of yet another possible scanning device provided by embodiments of the present application.
  • the wave plate layer may include a quarter wave plate
  • the polarizing plate layer may include a polarizing plate.
  • the wave plate layer may include a quarter wave plate and a half wave plate
  • the polarizing plate layer may include a polarizing plate.
  • the half-wave plate can be attached to the polarizing plate layer
  • the quarter-wave plate can be attached to the half-wave plate.
  • the arrangement sequence of the multiple wave plates in the wave plate layer can be designed in other ways.
  • the quarter-wave plate can be attached to the polarizing plate layer
  • the half-wave plate can be attached to the quarter-wave plate.
  • This application The various setting sequences are not listed one by one.
  • the difference between the first angle and the second angle is less than or equal to the first threshold, and the first angle is the angle between the polarization direction of the polarizer layer and the optical axis direction of the wave plate layer, and the The second angle is 45°.
  • the first threshold may be 0.2°, that is, the angle between the polarization direction of the polarizer layer and the optical axis direction of the 1/4 wave plate (or the equivalent optical axis direction of the 1/4 wave plate and the 1/2 wave plate). The angle is 45° ⁇ 0.2°.
  • the linearly polarized light incident on the wave plate after passing through the polarizer can be converted into circularly polarized light as much as possible, thereby improving the blocking effect of the polarizer layer on the light signal returned by the window, reducing the generation of ghost images, and weakening the intensity of the interference signal. Helps improve the recognition accuracy of lidar.
  • an anti-reflection coating is present on the first surface of the wave plate layer. In this way, the probability of the optical signal transmitting through the wave plate layer can be increased, the loss of the optical signal can be reduced, the signal effectiveness can be improved, and the identification accuracy of the detection device can be improved.
  • the first surface may be a surface away from the scanner body.
  • the reflective surface includes a substrate, and the material of the substrate is a reflective material.
  • the substrate can be a metal (hereinafter referred to as a metal substrate).
  • the following description takes a metal substrate as an example.
  • Figure 21 shows a schematic structural diagram of another possible scanning device provided by an embodiment of the present application.
  • the reflective surface of the scanning device is provided by a metal substrate.
  • the substrate may be disposed on the scanner body.
  • the substrate can also serve as the scanner body.
  • FIG. 22 is a schematic structural diagram of another possible scanning device provided by an embodiment of the present application.
  • the reflective surface of the scanning device and the scanner body are both provided by a metal substrate.
  • the reflective surface includes a substrate and a reflective coating, and the reflective coating is attached to the surface of the substrate.
  • the reflective coating can reflect light signals.
  • the reflective surface of the scanning device is provided by the reflective coating, and the substrate is used to carry the reflective coating.
  • the material of the substrate may include materials such as glass, crystal, inorganic minerals, or metals.
  • FIG. 23 shows a schematic structural diagram of another possible scanning device provided by an embodiment of the present application, in which the reflective coating carried on the substrate forms a reflective surface.
  • the substrate may be disposed on the scanner body. In some scenarios, the substrate can also serve as the scanner body.
  • FIG. 24 is a schematic structural diagram of another possible scanning device provided by an embodiment of the present application.
  • the reflective surface is provided by a reflective coating, and the substrate, in addition to carrying the reflective coating, can also serve as the main body of the scanner.
  • Embodiments of the present application also provide a lidar.
  • the lidar includes a scanner, a laser transmitter and a receiver.
  • the laser transmitter is used to generate a transmission signal.
  • the receiver is used to detect light signals.
  • the scanner includes the scanning method described in the previous embodiment.
  • Device such as shown in Figure 4, Figure 11, Figure 13, Figure 14, Figure 15, Figure 16, Figure 17, Figure 18, Figure 19A, Figure 19B, Figure 20A, Figure 20B, Figure 21, Figure 22, or Figure 23 Scanning device of an embodiment, or a possible design thereof.
  • the lidar further includes a window, the light signal reflected by the window is blocked by the polarizer layer in the scanning device, and the light signal reflected from objects in the field of view of the lidar is blocked by the The scanning device is provided to the receiver.
  • the above-mentioned window can be replaced with other optical components in the lidar.
  • the above-mentioned lidar can also be replaced by other light detection devices, such as fusion detection devices, etc.
  • An embodiment of the present application also provides a terminal, which includes the aforementioned detection device, such as the detection device 30, or the above-mentioned laser radar.
  • the terminal (or specifically the detection device in the terminal) includes the scanning device described in the previous embodiments, such as Figure 4, Figure 11, Figure 13, Figure 14, Figure 15, Figure 16, Figure 17, Figure 18, Figure 19A, The scanning device of the embodiment shown in Figure 19B, Figure 20A, Figure 20B, Figure 21, Figure 22, Figure 23, or Figure 24, or possible designs thereof.
  • Figure 25 is a schematic structural diagram of a possible terminal 250 provided by an embodiment of the present application.
  • the terminal 250 includes a processor 2501 and the aforementioned detection device 30.
  • the processor 2501 and the detection device 30 may be connected or communicated.
  • the embodiments of this application do not limit the specific implementation of the connection or communication.
  • the processor is used to obtain detection data about objects in the field of view based on the return signal received by the receiving module of the detection device 30 .
  • detection data can specifically be point cloud data corresponding to the field of view, or the detection data can include the distance, orientation, pixel area occupied by the target, height, speed, attitude or shape information of the target in the field of view, etc.
  • the processor 2501 is a module that performs arithmetic operations and/or logical operations, and may specifically include one or more of the following devices: central processing unit (central processing unit, CPU), application processor (application processor, AP), Time-to-Digital Converter (TDC), filter, graphics processing unit (GPU), microprocessor unit (MPU), Application Specific Integrated Circuit (Application Specific Integrated Circuit) , ASIC), image signal processor (image signal processor, ISP), digital signal processor (digital signal processor, DSP), field programmable logic gate array (Field Programmable Gate Array, FPGA), complex programmable logic device (Complex programmable logic device (CPLD), coprocessor (assist the central processor to complete corresponding processing and applications), microcontroller unit (Microcontroller Unit, MCU), and/or neural network processor (neural-network processing unit, NPU), etc.
  • CPU central processing unit
  • application processor application processor, AP
  • TDC Time-to-Digital Converter
  • filter filter
  • GPU graphics processing unit
  • MPU
  • the above-mentioned terminals may include mobile platforms or transportation vehicles such as vehicles, ships, airplanes, trains, spacecrafts, drones, and robots.
  • the embodiments of the present application can also be applied to the field of smart car technology, such as vehicle outreach (vehicle to everything, V2X), inter-vehicle communication long-term evolution technology (Long Term Evolution-vehicle, LTE ⁇ V), vehicle to vehicle (vehicle to vehicle, V2V) etc.
  • vehicle outreach vehicle to everything, V2X
  • inter-vehicle communication long-term evolution technology Long Term Evolution-vehicle, LTE ⁇ V
  • vehicle to vehicle vehicle to vehicle
  • V2V vehicle to vehicle
  • connection should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, a conflicting connection or an integral connection. connection; for those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood on a case-by-case basis.
  • At least one mentioned in the embodiments of this application means one or more, and “multiple” means two or more. “At least one of the following” or similar expressions thereof refers to any combination of these items, including any combination of a single item (items) or a plurality of items (items).
  • at least one of a, b, or c can represent: a, b, c, (a and b), (a and c), (b and c), or (a and b and c), where a, b, c can be single or multiple.
  • “And/or” describes the relationship between related objects, indicating that there can be three relationships.
  • a and/or B can mean: A alone exists, A and B exist simultaneously, and B exists alone, where A and B can be singular or plural.
  • the character "/" generally indicates that the related objects are in an "or” relationship.
  • first and second optical signal are only for convenience of description and do not represent the difference in the source, order, importance, etc. of the first optical signal and the second optical signal.
  • the third optical signal The first optical signal and the second optical signal may also be the same optical signal.

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Abstract

一种扫描装置（40）、激光雷达和终端，可以应用于探测、智能测绘、智能驾驶等领域。其中，扫描装置（40）包括扫描器主体、偏振片层、波片层，扫描器主体具有至少一个反射面，扫描器主体的反射面上贴合有偏振片层，偏振片层上贴合有波片层。通过在反射面上设置波片层和偏振片层，对于经过扫描器出射出去的光信号，在被光学元件反射回到扫描装置（40）时会被偏振片层阻挡。该方案能够减少鬼像的产生,减弱干扰信号的强度，有助于提升探测装置的识别精度。

Description

一种扫描装置、激光雷达和终端 技术领域
本申请涉及探测技术，尤其涉及一种扫描装置、激光雷达和终端。
背景技术
激光雷达是一种将激光技术与光电转换技术相结合的探测装置，通过发射激光信号探测目标物体的位置、形状、速度等特征量。激光雷达在感知周围的环境时，不可避免的会遇到高反射率或者特殊反射率(简称角反)目标。例如，公路上的指示牌、警示牌、路标牌，路边的安全柱、防护栏、转角的凸面镜以及车辆的车牌、车身上的高反涂层贴纸等。这些高反射率(简称高反)目标或者角反目标会产生较强的散射光，较强的散射光可能会对真实的回波信号产生影响。例如，探测装置可能会误检测到高反目标或者角反目标的鬼像。再如，高反目标或者角反目标返回的信号可能会淹没真实物体的回波信号。
例如，图1、图2所示为一些探测装置的工作场景，发射模块发射的光信号可以经过扫描器达到探测区域。如图1所示，一些情况下，光信号正常通过光学元件到达探测区域内，被探测区域中的物体反射后经过扫描器被接收模块接收。
但是，发射信号可能会被光学元件反射，反射的信号可能会经过扫描器反射再次到达探测区域内。如图2的(a)部分所示，一些情况下，一部分光信号(如信号1)会被光学元件反射，光学元件反射的信号(如信号2)达到扫描器后，再次被扫描器反射到视野中(如信号3)。如图2的(b)部分所示，若视野中存在高反目标(或角反目标)，可能会产生较强的反射信号(信号4)，反射信号经过扫描器(如信号5、信号6、信号7的光路所示)被接收模块接收，由于接收模块无法分辨这些经过多次扫描器反射到探测区域的信号，所以会误认为在另一区域存在某一物体，从而形成了高反目标(或角反目标)鬼像。如图2的(c)部分所示，高反目标返回的信号也可能通过扫描器到达接收模组，形成干扰信号。
鬼像和/或干扰信号的存在，都将会影响激光雷达对目标物体的识别，因此，如何提高激光雷达识别的准确度是本领域技术人员正在研究的问题。
发明内容
本申请实施例提供一种扫描装置、激光雷达和终端，能够减少鬼像问题的产生，有助于提升激光雷达的识别精度。
第一方面，本申请实施例提供了一种扫描装置，包括扫描器主体、偏振片层、波片层，所述扫描器主体具有至少一个反射面，所述扫描器主体的反射面上贴合有偏振片层，所述偏振片层上贴合有波片层。
其中，波片层包含一个或者多个波片。波片，又称为相位延迟片，它是由双折射的材料加工而成。波片能够使通过波片的光信号的两个互相正交的偏振分量产生相位偏移，可用来调整光束的偏振状态。
可选的，波片层能够使得通过的光信号的一个正交分量产生(2k+1)π/2的相位偏移，其中，k为自然数。示例性的，波片层可以包含四分之一波片，四分之一波片能够使得通过的光信号的正交分量产生π/2的相位偏移。示例性的，波片层可以包含四分之一波片和二分之 一波片，四分之一波片和二分之一波片的组合，能够使得通过的光信号的正交分量产生3π/2的相位偏移。
偏振片层具有偏振片，或者，偏振分光器件。偏振片是一种光滤波器，光信号经过偏振片时的透射率与光信号的偏振方向相关，通常是某一方向的线偏振光可以通过，而偏振方向与其垂直的光则被阻挡(不能通过)，偏振方向与其垂直的光会被吸收或者反射到其它的方向上。
可选的，扫描装置进行整体活动以形成多种角度的反射面。例如，整体活动包含摆动、或转动等活动。
偏振光在发生镜面反射时，反射回来的光线仍然是偏振光。因此，通过在反射面上设置波片层和偏振片层，对于经过扫描装置出射出去的光信号，在被光学元件反射回到扫描装置时会被偏振片层阻挡。因此，本申请的扫描装置能够消除被光学元件反射回来的发射信号，避免光学元件反射的信号再次被扫描装置反射到探测区域，能够减少鬼像的产生有助于提升探测装置(如激光雷达等)的识别精度。
另外，光路、光轴的稳定性和精确性能够直接偏振片、波片等器件的使用效果。本申请中的波片层、偏振片层使用贴合的方式结合在反射面上，能够降低振动对于光学元件的影响，提升扫描装置的稳定性，有助于提升探测装置的探测性能。
在第一方面的一种可能的实施方式中，所述偏振片层通过胶合方式贴合在所述扫描器主体的反射面上。通过胶合方式在反射面上粘贴偏振片层，能增强光学元件之间的连接稳定性，降低振动对于光学元件的影响，提升扫描装置的稳定性，有助于提升探测装置的探测性能。
其中，胶合(也称粘合、粘接、胶结)是指同质或异质物体表面用胶黏剂连接在一起的技术。胶黏剂通过界面的黏附和内聚等作用，能使两种或两种以上的制件或材料连接在一起的天然的或合成的、有机的或无机的一类物质，又叫黏合剂，日常生活中也简称为胶。
示例性的，胶合方式可以通过光学透明胶黏剂(optically clear adhesive，OCA)来实现。
一种可能的设计中，胶合方式包含如下方式：通过施加压力使两个光学零件表面吸附在一起。在这种情况下，贴合的两个光学零件的表面通常是清洁、光滑的，而且面形一致。在一些场景中，这种方式也称为光胶。通过光胶进行胶合，能使得偏振片层和反射面之间的平面更平整，提升光的透射率，减少能耗。
在第一方面的又一种可能的实施方式中，所述波片层通过胶合方式贴合在所述偏振片层上。通过胶合方式在偏振片层上粘贴波片，能增强光学元件之间的连接稳定性，降低振动对于光学元件的影响，提升扫描装置的稳定性，有助于提升激光雷达的探测性能。
可选的，胶合方式包含通过胶黏剂连接、通过光胶连接等。
在第一方面的又一种可能的实施方式中，入射光信号依次入射所述波片层、偏振片层，被所述反射面反射后依次从所述偏振片层和所述波片层出射，得到出射信号。
可选的，当反射器主题具有多个反射面时，在每个反射面中，从扫描器主体开始，从内到外分别为扫描器主体、偏振片层、波片层。
在第一方面的又一种可能的实施方式中，所述偏振片层用于阻挡所述出射信号对应的镜面反射光信号，所述镜面反射光信号为所述出射信号发生镜面反射后得到的光信号。
可理解的，当光信号在物体表面发生漫反射时，漫反射光为自然光。当光在物体表面发射镜面发射时，镜面反射光为偏振光。由于偏振片层能够阻挡偏振方向垂直于偏振片的偏振方向的光信号，因此，当出射信号的镜面反射信号经过波片层后，其偏振方向于偏振片层的偏振方向垂直，因此偏振片层能够阻挡出射信号对应的镜面反射光信号。
由于光学元件(例如视窗)本身反射的光信号通常为镜面反射光信号，因此，本申请的扫描装置能够阻挡光学元件反射的光信号，从而避免光学元件返回的信号再次被照射到市场中，能够减少鬼像的产生，减弱干扰信号的强度，有助于提升探测装置(如激光雷达等)的识别精度。
在第一方面的又一种可能的实施方式中，所述偏振片层用于阻挡第一反射光信号、以及透过第二反射光信号，其中，所述第一反射光信号由视窗反射所述出射信号得到，所述第二反射光信号由所述扫描装置的视野内的物体反射所述出射信号得到。
在上述实施方式中，出射信号被视窗反射，再次到达扫描装置。而本申请可以阻挡视窗返回的信号，从而避免视窗返回的信号再次被照射到探测区域，能够减少鬼像的产生，减弱干扰信号的强度，有助于提升信号有效性。
在第一方面的又一种可能的实施方式中，来自激光发射器的第一光信号依次经过所述波片层、偏振片层，得到第二光信号，所述第二光信号与所述偏振片层的偏振方向平行；
所述第二光信号由所述至少一个反射面反射后，经过所述偏振层得到第三光信号所述第三光信号的偏振方向与所述偏振片层的偏振方向平行；
所述第三光信号经过所述波片层得到第四光信号，所述第四光信号的偏振方向为圆偏振；
所述第四光信号对应的返回信号包含第五光信号和第六光信号，其中，所述第五光信号为所述第四光信号经过镜面反射得到的光信号，所述第六光信号为所述第四光信号经过漫反射得到的光信号，所述第五光信号的偏振方向为圆偏振；
所述第五光信号入射所述波片层、被所述波片层转换为第七光信号，所述第七光信号入射所述偏振片层，所述第七光信号被所述偏振片层阻挡，所述第七光信号的偏振方向与所述偏振片层的偏振方向垂直；
所述第六光信号入射所述波片层，透过所述波片层入射所述偏振片层，所述第六光信号中偏振方向与所述偏振片层的偏振方向垂直的光信号被所述偏振片层阻挡，所述第六光信号中偏振方向与所述偏振片层的偏振方向平行的光信号透过所述偏振片层，得到第八光信号；
所述第八光信号被所述至少一个反射面反射，并依次透过所述偏振层、所述波片层后被提供给接收器。
在第一方面的又一种可能的实施方式中，所述第五光信号由视窗反射所述出射信号得到，所述第六光信号由所述扫描装置的视野内的物体反射所述出射信号得到。
在第一方面的又一种可能的实施方式中，所述扫描器主体包含第一部分和第二部分，所述第一部分和所述第二部分沿转轴或摆轴方向排布，所述偏振片层贴合于所述扫描器主体的所述第一部分的反射面上，所述扫描器主体的所述第二部分的反射面上不设置所述偏振片层。
在上述实施方式中，扫描器主体具有多个部分，第一部分用于发射信号，第二部分用于接收信号。由于第一部分中设置有偏振片层，从而可以阻挡镜面反射光信号。由于第二部分不设置偏振片层，从而可以避免削弱对探测区域内返回的信号的能量，从而提升光的透射率，减少能耗，有助于提升信号有效性。
在第一方面的又一种可能的实施方式中，来自激光发射器的第一光信号依次经过所述波片层、偏振片层，得到第二光信号，所述第二光信号与所述偏振片层的偏振方向平行；
所述第二光信号由所述第一部分的反射面反射后，经过所述偏振层得到第三光信号所述第三光信号的偏振方向与所述偏振片层的偏振方向平行；
所述第三光信号经过所述波片层得到第四光信号，所述第四光信号的偏振方向为圆偏振；
所述第四光信号对应的返回信号包含第九光信号和第十光信号，其中，所述第九光信号 为所述第四光信号经过镜面反射得到的光信号，所述第十光信号为所述第四光信号经过漫反射得到的光信号，所述第九光信号的偏振方向为圆偏振；
所述第九光信号入射所述波片层、被所述波片层转换为第十一光信号，所述第十一光信号入射所述偏振片层，所述第十一光信号被所述偏振片层阻挡，所述第十一光信号的偏振方向与所述偏振片层的偏振方向垂直；
所述第十光信号照射到所述扫描器主体的第二部分的反射面，被所述扫描器主体的第二部分的反射面反射，得到第十二光信号，所述第十二光信号被提供给接收器。
在第一方面的又一种可能的实施方式中，所述第九光信号由视窗反射所述出射信号得到，所述第十光信号由所述扫描装置的视野内的物体反射所述出射信号得到
在第一方面的又一种可能的实施方式中，所述波片层包含四分之一波片。
在第一方面的又一种可能的实施方式中，所述波片层包含四分之一波片和二分之一波片。上述实施方式中，“1/2波片+1/4波片”的组合具有消色散的效果，即使在高低温情况下、在波长漂移时，鬼像也能够被消除，有助于提升探测装置(如激光雷达等)的识别精度。
在第一方面的又一种可能的实施方式中，所述反射面包含基底，所述基底为金属。
在第一方面的又一种可能的实施方式中，所述反射面包含基底和反射镀膜，所述反射镀膜贴合在所述基底的表面上。
在第一方面的又一种可能的实施方式中，所述基底的材料为玻璃或晶体。
在第一方面的又一种可能的实施方式中，第一角度与第二角度的差值小于或等于第一阈值，所述第一角度为所述偏振片层的偏振方向与所述波片层的光轴方向的夹角，所述第二角度为45°。
由于波片具有一个快轴和一个慢轴，都是垂直于表面和光束传播方向的，并且快轴和慢轴相互垂直。本申请实施例中，如果入射光信号为线偏光，且入射光信号与波片层的光轴之间夹角为45°。入射光信号通过波片层后，出射信号为圆偏振光。反之，圆偏振光通过波片层后可以得到线偏振光。若入射光信号于光轴之间的夹角偏离45°，那么线片光通过波片层后得到椭圆偏振光。
因此，通过设置偏振片层的偏振方向和波片层的光轴方向，能够控制偏振片层对于镜面反射光信号的阻挡效果，从而更满足用户的需求。当第一角度越接近45°，偏振片层可以对于镜面反射光信号的阻挡效果越好，越能够减少鬼像的产生。
在第一方面的又一种可能的实施方式中，所述波片层的第一表面上存在增透膜，所述第一表面为远离所述扫描器主体的表面。
通过设置增透膜，可以提升光信号在波片层的透过率，减少能耗，有助于提升信号有效性。
第二方面，本申请实施例提供一种探测装置，所述探测装置包含扫描模块、发射模块和接收模块，所述发射模块用于产生发射信号，所述接收模块用于探测光信号，所述扫描模块包含第一方面任一项所描述的扫描装置。
在第二方面的一种可能的实施方式中，所述探测装置还包括视窗，由所述视窗反射回来的光信号被所述扫描装置中的偏振片层阻挡，来自所述探测装置的视野内物体反射回来的光信号被所述扫描装置提供给所述接收模块。
第三方面，本申请实施例提供一种终端，所述终端包含第一方面任一项所描述的扫描装置，或者，所述终端包含第二方面任一项所描述的探测装置。
可选的，终端为车辆、无人机或者机器人。
附图说明
下面将对实施例描述中所需要使用的附图作简单的介绍。
图1是一种探测装置的工作场景示意图；
图2是一种探测装置的工作场景示意图；
图3是本申请实施例提供的一种探测装置的架构示意图；
图4是本申请实施例提供的一种扫描装置的架构示意图；
图5是本申请实施例提供的一种经过扫描装置的光路示意图；
图6是本申请实施例提供的一种激光信号经过扫描装置的光路示意图；
图7是本申请实施例提供的一种发射光路的示意图；
图8是本申请实施例提供的一种接收光路示意图；
图9是本申请实施例提供的又一种接收光路示意图；
图10是本申请实施例提供的一种扫描装置的使用场景示意图；
图11是本申请实施例提供的又一种可能的扫描装置的结构示意图；
图12是本申请实施例提供的又一种扫描装置的使用场景示意图；
图13是本申请实施例提供的又一种扫描装置的结构示意图；
图14是本申请实施例提供的又一种扫描装置的结构示意图；
图15是本申请实施例提供的又一种扫描装置的结构示意图；
图16是本申请实施例提供的又一种扫描装置的结构示意图；
图17是本申请实施例提供的一种扫描装置的层连接方式示意图；
图18是本申请实施例提供的又一种扫描装置的层连接方式示意图；
图19A是本申请实施例提供的又一种扫描装置的层连接方式示意图；
图19B是本申请实施例提供的又一种扫描装置的层连接方式示意图；
图20A是本申请实施例提供的又一种扫描装置的结构示意图；
图20B是本申请实施例提供的又一种扫描装置的结构示意图；
图21是本申请实施例提供的又一种扫描装置的结构示意图；
图22是本申请实施例提供的又一种扫描装置的结构示意图；
图23是本申请实施例提供的又一种扫描装置的结构示意图；
图24是本申请实施例提供的又一种扫描装置的结构示意图；
图25是本申请实施例提供的一种终端的结构示意图。
具体实施方式
为了使本申请实施例的目的、技术方案和优点更加清楚，下面将结合附图对本申请实施例作进一步地详细描述。
为了便于理解，以下示例地给出了部分与本申请实施例相关概念的说明以供参考。如下所述：
1.探测装置
本申请实施例中提到的探测装置可以是激光雷达，也可以是其它的光探测装置，例如融合探测装置(例如，集成雷达探测器和图像传感器的探测装置)。其工作原理是通过发射光信号，并接收返回的光信号来探测相应的探测区域。
本申请实施例中的探测装置能够使用在智能驾驶、智能运输、智能制造、环境探测、测绘、无人机等各种领域，能够完成目标探测、距离测量、速度测量、目标跟踪、成像识别等中的一项或者多项功能。
本申请实施例中的探测装置可以应用于车载探测装置(例如车载雷达)、路侧探测装置(例如路口雷达)等，也可以应用于其它的探测装置，例如安装在无人机、机器人、轨道车、自行车、信号灯、测速装置或基站等等装置上面的探测装置。本申请对探测装置安装的位置不做限定。
2.扫描
扫描的过程依赖扫描装置来实现，其中，扫描装置活动的方式可以是转动、摆动、电学控制等方式。
其中，机械式扫描是指通过惯性扫描器件实现对视场范围的扫描。例如，以2D扫描为例，2D机械扫描可以通过2D扫描器件实现，或者，通过两个1D维度扫描的组合实现。
3.波片
波片，又称为相位延迟片，它是由双折射的材料加工而成。波片能够使通过波片的光信号的两个互相正交的偏振分量产生相位偏移，可用来调整光束的偏振状态。
波片具有一个快轴和一个慢轴，都是垂直于表面和光束传播方向的，并且快轴和慢轴相互垂直。本申请实施例中，如果入射光信号为线偏光，且入射光信号与波片层的光轴之间夹角为45°。入射光信号通过波片层后，出射信号为圆偏振光。反之，圆偏振光通过波片层后可以得到线偏振光。若入射光信号于光轴之间的夹角偏离45°，那么线片光通过波片层后得到椭圆偏振光。
4.偏振(polarization)
偏振，是指光的电矢量的振动方向具有一定的规律。偏振是光的一种固有属性，偏振状态(polarization state)是光的一个参数。偏振状态可分为：线偏振，椭圆偏振(包含圆偏振)。
例如，对于线偏振光，它的电矢量沿着一个方向做往复振动。
而非偏振光，如自然光，它们的电矢量的振动是杂乱无章的，既不朝着某些相同的方向，振动时又不具有固定的时间对应关系(没有固定相位)，因此，它们的振动是随机的，没有固定规律的。
5.偏振片
偏振片是一种光滤波器，光信号经过偏振片时的透射率与光信号的偏振方向相关，通常是某一方向的线偏振光可以通过，而偏振方向与其垂直的光则被阻挡(不能通过)，偏振方向与其垂直的光会被吸收或者反射到其它的方向上。
为了方便光信号经过偏振片时产生的现象，我们通常用P偏振光(以下简称P光)和S偏振光(以下简称S光)来区分光信号。其中，P光表示振动方向与偏振片的偏振方向平行的线偏振光，S光表示振动方向与偏振片的偏振方向的线偏振光。
6.胶合
胶合(也称粘合、粘接、胶结)是指同质或异质物体表面用胶黏剂连接在一起的技术。胶黏剂通过界面的黏附和内聚等作用，能使两种或两种以上的制件或材料连接在一起的天然的或合成的、有机的或无机的一类物质，又叫黏合剂，日常生活中也简称为胶。
可选的，胶合方式可以通过光学透明胶黏剂(optically clear adhesive，OCA)来实现。
一种可能的设计中，胶合方式包含如下方式：通过施加压力使两个光学零件表面吸附在一起。在这种情况下，贴合的两个光学零件的表面通常是清洁、光滑的，而且面形一致。在 一些场景中，这种方式也称为光胶。
7.视野(field of view，FOV)
视野是指可以被探测装置探测到的范围，也称为视场。一些场景中，探测装置的发射端与目标物体之间，或者，探测装置的接收端与目标物体之间，需要具有信号(例如无线电波、激光)传输不中断的视线区域(line of sight，LOS)。该视线区域即可以理解为视野。
本申请实施例中将探测装置所能够探测的物理世界称为探测区域。在一些具体实施例中，探测区域所指的物理世界是指位于所述探测装置外部的物理世界，这里的外部可以是探测装置的最外层部件的外部，例如，激光雷达的视窗之外。
下面对本申请实施例应用的系统架构进行介绍。需要说明的是，本申请描述的系统架构和业务场景是为了更加清楚的说明本申请的技术方案，并不构成对于本申请提供的技术方案的限定。应理解，随着系统架构的演变和新业务场景的出现，本申请提供的技术方案对于类似的技术问题，同样适用。
本申请实施例提供的探测装置30的架构如图3所示，包含发射模块301和扫描模块302。其中：
(1)发射模块301包含光源，光源用于产生光信号。示例性的，光源可以包含发光元件(如激光发射器等)，可以产生红外光、紫外光、可见光或其他波长的光信号。
一些可能的实施方式中，发射模块301可以包含以下发光元件中的一项或者多项：半导体激光器、光纤激光器、或气体激光器等激光器。其中，半导体激光器具体可以包括激光二极管(laser diode，LD)、垂直腔面发射激光器(Vertical Cavity Surface Emitting Laser，VCSEL)、边缘发射激光器(edge-emitting laser，EEL)、分布式反馈激光器(distributed feedback LD，DFB-LD)、分布式布拉格反射激光器(distributed brag reflection LD，DBR-LD)、光栅耦合采样反射激光器(Grating coupled sampling reflection LD，GCSR-LD)、微光机电系统激光器(micro optical electromechanical system LD，MOEMS-LD)等发光元件。
(2)扫描模块302用于改变光的传播方向。例如，扫描模块302可以改变来自光源的光信号的传播方向，和/或，扫描模块302可以改变来自视野内物体的光信号的传播方向。
本申请实施例中，扫描模块可以包含至少一个反射面，通过改变反射面的角度，可以将来自光源的光信号照射到视野中的不同位置上，从而完成对探测区域的探测。
(3)可选的，探测装置30还可以包含接收模块303。接收模块303用于接收光信号。进一步的，接收模块可以基于光信号得到电信号。可选的，该电信号可以作为探测数据输出，或者电信号经过处理得到探测数据再进行输出。
可选的，接收模块303可以包含一个或者多个探测元件。例如，接收模块可以包含以下探测元件中的一项或者多项：单光子雪崩二极管(single-photon avalanche diode，SPAD)、硅光电倍增管(Silicon photomultiplier，SiPM)、半导体雪崩光电二极管(avalanche photo detector，APD)、多像素光子计数器(multi-pixel photon counter，MPPC)、或者电子倍增电荷耦合器(electron multiplying charge-coupled device，EMCCD)等探测元件中的至少一个。
在接收模块303包含多个探测元件的情况下，多个探测元件可以是阵列排布的，例如通过线阵或者面阵(可选具有寻址读取功能)形式排布。作为一种可能的方案，接收模块可以包含1×2阵列、2×3阵列、或3×3阵列等规格的阵列探测元件，本申请对于阵列排布的行数和列数不做限定。
(4)可选的，探测装置30还可以包含控制模块304，控制模块304用于控制发射模块 301、扫描模块302或接收模块303等中的一个或者多个。
(5)可选的，探测装置30还可以包含一个或者多个光学元件，例如视窗、整形器件(例如准直装置、或光路整形器件等)、反射镜、透镜、偏振镜、滤光镜、或匀光片等。本申请实施例中涉及的探测装置中，对于探测装置中的光学元件的数量、摆放位置、摆放顺序、大小等不做限定。应理解，本申请实施例中发射模块、接收模块、光学元件等的数量和安装位置不做限定，图3仅是为了便于描述而示出的一种可能的情况，不作为对探测装置30的限定。
在使用上述的探测装置进行探测时，由于视窗或者光学元件返回的光信号可能会被扫描装置二次反射，这些二次反射的信号很可能照射到探测区域中，当二次反射的信号被探测区域中的高反目标或者角反目标反射回到探测装置时，可能会对真实的回波信号产生影响。例如，探测装置可能会误检测到高反目标或者角反目标的鬼像。再如，高反目标或者角反目标返回的信号可能会淹没真实物体的回波信号。
有鉴于此，本申请实施例提供一种扫描装置、激光雷达和终端，能够减少鬼像的产生，减弱干扰信号的强度，有助于提升探测装置(如激光雷达等)的识别精度。
本申请实施例尤其适用于扫描式激光雷达中。示例性地，本申请实施例提供的扫描装置可以应用于前述的探测装置30中，例如，扫描装置可以替换扫描模块302，或者，扫描装置可以包含于扫描模块302中。
下面对本申请实施例的方案进行详细说明。
请参见图4，图4是本申请实施例提供的一种扫描装置40的结构示意图。扫描装置40包括扫描器主体、偏振片层、波片层。其中，扫描器主体具有至少一个反射面，扫描器主体的反射面上贴合有偏振片层，偏振片层上贴合有波片层。如图5所示，当入射光信号到达扫描装置时，光信号依次入射波片层、偏振片层，被反射面反射后依次从偏振片层和波片层出射。
本申请的扫描装置中，线偏光入射波片层后，出射信号为圆偏光。换句话说，波片层能够使得通过的光信号的一个正交分量产生(2k+1)π/2的相位偏移，其中，k为自然数。
偏振光在发生镜面反射时，反射回来的光线仍然是偏振光。因此，出射信号经过镜面反射后得到镜面反射光信号也为圆偏光。该圆偏光入射波片层以后，得到偏振方向垂直于偏振片层的偏振方向的光信号。由于偏振方向与偏振片层的偏振方向垂直的光会被阻挡(不能通过)，此处的阻挡可以是吸收，或者，反射到其它的方向上。
由于光学元件的表面通常是平滑的，光信号在光学元件上会产生镜面反射。经过扫描装置出射出去的光信号，在被光学元件反射回到扫描装置时会被偏振片层阻挡。因此，本申请的扫描装置能够消除被光学元件反射回来的发射信号，避免光学元件反射的信号再次被扫描装置反射到视场内，能够减少鬼像的产生，减弱干扰信号的强度，有助于提升激光雷达的识别精度。另外，本申请中的波片层、偏振片层使用贴合的方式结合在反射面上，能够降低振动对于光学元件的影响，提升扫描装置的稳定性，有助于提升探测装置的探测性能。
以上对扫描装置的结构进行了介绍，下面介绍一些本申请实施例的可能实施方式。需要说明的是，下面的多种实施方式可以单独实施，也可以进行组合，对于组合的情况本申请实施例不再赘述。
如图6所示为本申请实施例提供的一种可能的激光信号经过扫描装置的光路示意图。其中，信号(1)为来自光源的光信号，信号(1)经过波片后，得到信号(2)。信号(2)入射 偏振片层，从偏振片层出射的信号为信号(3)。由于偏振方向平行于偏振片层的光信号才能够通过，因此信号(3)的偏振方向平行于偏振片层的偏振方向，即：信号(3)为P光。为了便于区分，将信号(3)记为P光_1。信号(3)经过扫描器主体的反射面，产生反射，得到信号(4)，记为P光_2。信号(4)再次经过偏振片层，得到信号(5)，信号(5)的偏振方向与偏振片层的偏振方向平行，记为P光_3。信号(5)入射波片层，出射信号为信号(6)，由于线偏光入射波片层后的出射光为圆偏光(考虑误差，也可能为椭圆偏振)，因此信号(6)为圆偏光。
来自发射模块的光信号从图5所示的扫描装置出射(以下便于描述，以下将来自发射模块且从扫描装置出射的光信号称为出射信号)以后，可以向视野范围中传播，但是在传播过程中可能会经过一些探测装置中的光学元件，例如视窗等。经过光学元件时，大部分光信号透过光学元件照射到探测区域内，但是部分光信号可能会被光学元件反射。如图7所示为本申请实施例提供的一种发射光路的示意图。出射信号一部分可以照射到探测区域的物体上，由于现实世界中的物体的表面通常是粗糙的，因此光信号照射在物体上时产生漫反射现象。而一部分出射信号可能会在光学元件(例如视窗等)产生反射，由于光学元件通常表面是光滑的，因此在光学元件表面的反射现象为镜面反射。
当偏振光被反射时，在漫反射和镜面反射现象中得到的反射信号的偏振状态有所不同。具体表现为：偏振光在镜面反射时，反射回来的光信号仍然是偏振光；偏振光在漫反射时，反射回来的光信号的偏振方向会发生变化。一些场景中，偏振光在镜面反射时，反射回来的光信号为偏振光，且偏振方向可能不发生改变(或者发生较小的改变)；偏振光在漫反射时，会变成自然光。
本申请实施例中，扫描装置可以阻挡光学元件所反射的出射信号。具体地，由于偏振光信号在镜面反射后仍然为偏振光信号。因此，出射信号为圆偏振光时，出射信号的镜面反射光信号仍然为圆偏振光。而当圆偏振光再次入射波片时，波片层能够将圆偏振光转换为线偏振光，且该线偏振光的偏振方向与偏振片层的偏振方向垂直，即S光。由于S光入射偏振片层时被阻挡，使得出射光信号的镜面反射光信号无法到达扫描装置的反射面，因此也无法被重新反射到探测区域内。如此，通过本申请实施例提供的扫描装置，能够避免光学元件反射的信号再次被扫描装置反射到视场内，减少鬼像的产生，减弱干扰信号的强度，有助于提升激光雷达的识别精度。
需要说明的是，原本可以通过偏振片层的光信号，经过反射面反射再次到达偏振片层时，原本通过偏振片层的光信号，其偏振方向可能已经发生改变，因此部分光信号可能会被偏振片层阻挡。以图6所示的发射信号为例，上述过程可以表现为：信号(5)与信号(4)不完全相同。具体的，信号(3)在第一时刻从偏振片层出射，此时信号(3)的偏振方向于偏振片平行；信号(4)在第二时刻到达偏振片层时，其偏振方向可能不再完全平行于偏振片层的偏振方向。因此，信号(4)中偏振方向平行于偏振片层的光信号通过偏振片层，形成信号(5)；而信号(4)中部分光信号被偏振片层阻挡。
应理解，由于扫描装置进行活动，因此偏振片层也会一起活动。而原本平行于偏振片层的偏振方向的光信号，在偏振片层活动以后，部分光信号可能会被偏振片层阻挡。以图6为例，由于偏振片在第一时刻和第二时刻之间位置变化，可能导致信号(4)的偏振方向不再完全平行于偏振片层的偏振方向。因此，信号(4)中偏振方向平行于偏振片层的光信号通过偏振片层，形成信号(5)；而信号(4)中部分光信号被偏振片层阻挡。
本申请实施例中，由于偏振片层贴合与扫描器主体上，因此偏振片层和扫描器主体进行 一致活动，可以降低偏振片层和反射面之间的相对位置差异，也缩短了发射光信号第二次到达偏振片层的传播时间，可以降低光信号的损耗，提升信号有效性。
应理解，本申请实施例为了方面描述经过某一层的光信号的性质，一些图示中在不同的层之间示出了间隔，但这些图示不应理解为对扫描装置的限制。在实施过程中，不同层级之间可能具有间隔，也可能不具有间隔，其是否具有间隔以及间隔的距离取决于具体设计。
需要说明的是，接收光路中，既包含探测区域的物体反射的光信号(以下称为真实物体的回波信号)，也包含来自光学元件的反射信号。
以下先说明来自光学元件的反射信号的光路。如图8所示为本申请实施例提供的一种接收光路示意图，其中，入射波片层的光信号，即信号(7)，为出射光信号(即：信号(6))的镜面反射光信号，因此信号(7)的偏振方向为圆偏振(考虑误差，也可能为椭圆偏振)，与信号(6)相同。信号(7)入射波片层后，出射光信号为信号(8)，信号(8)为线偏振光，信号(8)的偏振方向垂直于偏振片层。由于偏振方向垂直于偏振片的偏振方向的光信号被阻挡，因此信号(8)被偏振片层阻挡。因此，出射光信号的镜面反射光信号无法被重新反射到探测区域内，不会对真实物体的回波信号造成干扰。
以下说明真实物体的回波信号的光路的可能设计。可选的，真实物体的回波信号可以经过扫描装置被提供给接收模块。
在一种设计中，真实回波信号也经过偏振片层、波片层和反射面，被反射面反射后经过偏振片层、波片层，被提供给接收模块。具体的，出射光信号的漫反射信号为自然光。自然光经过波片层仍然为自然光，自然光经过波片后仍然为自然光。当自然光经过偏振片层时，出射光信号为S光，S光经过扫描器主体的反射面反射，进一步再次通过偏振层入射波片层，波片层将S光转换为圆偏光。进一步的，该圆偏光可以向接收模块的方向继续传播。
请参见图9，图9是本申请实施例提供的又一种接收光路的示意图。信号(9)为探测区域中物体反射出射光信号得到的光信号，即真实物体的回波信号。信号(9)经过波片层得到信号(10)，信号10入射偏振片层后，偏振方向平行于偏振片层的光信号被透射，得到信号(11)，信号(11)的偏振方向平行于偏振片层的偏振方向，便于区分记为：P光_4。信号(11)在反射面上产生反射，得到信号(12)，记为：P光_5。信号(12)再次经过偏振片层，偏振方向平行于偏振片层的光信号被透射，得到信号(13)，记为：P光_6。信号13经过波片层后，得到信号(14)，由于信号(13)为线偏光，线偏光经过波片层后为圆偏光，因此信号(14)为圆偏光。信号(14)被提供给接收模块。
应理解，信号(11)、信号(12)、信号(13)是不同时刻的P光，其偏振方向或者能量大小可能不相同，或者不完全相同。相关描述可以参考前述对信号(4)和信号(5)不同的相关描述，此处不再赘述。
图10以光学元件是视窗为例，示出的一种可能的扫描装置的使用场景示意图。可以看出，视窗所反射的出射光信号，在经过偏振片层时被阻挡；探测区域的物体所返回的回波信号，在依次经过扫描装置的波片层、偏振片层、反射面、偏振片层、波片层后，被提供给接收模块。
在又一种设计中，真实物体的回波信号不经过偏振片层。
示例性的，偏振片层可以设置于一部分反射面上，一部分反射面上不设置偏振片层。示例性的，图11所示为本申请实施例提供的又一种可能的扫描装置的结构示意图，其中，扫描器主体上具有反射面。扫描器主体包含第一部分和第二部分，第一部分上设置偏振片层，而第二部分上不设置偏振片层。
如图12所示为本申请实施例提供的又一种可能的扫描装置的使用场景示意图。在发射信号时，发射信号经过第一部分反射到达探测区域，来自探测区域的返回信号经过第二部分反射，提供给接收模块。进一步的，被光学元件反射返回的信号可以照射到第一部分上设置的波片层和偏振片层中，被偏振片层阻挡，具体可以参考前述图8、图10所示的实施例，此处不再赘述。
应理解，图11和图12以第二部分不设置偏振片层和波片层为例进行了描述。在实际过程中，在不设置偏振片层的部分，可以设置波片层，或者，也可以不设置波片层，或者还可以设置部分波片层。示例性的，图13所示为本申请实施例提供的又一种可能的扫描装置的结构示意图，扫描器主体包含第一部分和第二部分，第一部分上设置偏振片层、波片层，而第二部分上不设置偏振片层，但设置波片层。在发射信号时，发射信号经过第一部分反射到达探测区域(经过反射面、偏振片层、波片层)；在接收返回信号时，来自探测区域的返回信号经过第二部分反射(经过反射面、波片层)，提供给接收模块。进一步的，被光学元件反射返回的信号可以照射到第一部分上设置的波片层和偏振片层中，被偏振片层阻挡，具体可以参考前述图8、图10所示的实施例，此处不再赘述。
下面提供对第一部分和第二部分的分布的可能设计。
前述的扫描装置在活动时，通过活动轴来传递运动、扭矩或弯矩。可选的，根据活动的情况，活动轴可以称为转轴、或摆轴等，为了便于描述，本申请实施例统一称为活动轴。
作为一种可能的方案，上述扫描器主体的第一部分和第二部分可以沿活动轴分布。示例性的，如图14所示为本申请实施例提供的又一种可能的扫描装置的结构示意图，其中，扫描器主体的第一部分和第二部分沿扫描装置的活动轴方向分布，其中，偏振片层设置于第一部分的扫描器主体上，第二部分的扫描器主体上不设置偏振片层。
上述例子均是以扫描装置包含一个反射面进行描述，本申请实施例还提供包含多个反射面的扫描装置，例如包含2个反射面、3个反射面、4个反射面或更多的反射面的扫描装置。在包含多个反射面的扫描装置中。在扫描装置包含多个反射面的情况下，每个反射面上的结构与本申请各实施例中描述的一个反射面的层级结构相同或类似。
下面对包含多个反射面的扫描装置进行示例性地介绍。请参见图15，图15是本申请实施例提供的又一种可能的扫描装置的结构示意图，该扫描装置的扫描器主体上包含4个反射面，每个反射面上设置有偏振层，偏振片层上方设置有波片层。扫描装置可以整体进行活动，例如转动、摆动等，形成不同的光信号出射角度(即光斑在空间中的指向角)、以及接收该角度的返回信号，从而实现对探测区域的扫描。
作为一种可能的方案，在扫描装置包含多个反射面的情况下，部分反射面上可以不设置偏振片层。图16所示为本申请实施例提的又一种可能的扫描装置的结构示意图，该扫描装置的扫描器主体可以包含第一部分和第二部分，其中，第一部分扫描器主体的反射面上设置偏振片层和波片层，第二部分扫描器主体的反射面上不设置偏振片层。
图16还展示了该扫描装置在收发光信号过程中的场景。在发射信号时，发射信号经过第一部分反射到达探测区域(经过反射面、偏振片层、波片层)；在接收返回信号时，来自探测区域的返回信号经过第二部分的反射面反射，提供给接收模块。可选的，在第二部分上可以设置波片层，具体可以参考图13，此处不再赘述。进一步的，被光学元件反射返回的信号可以照射到第一部分上设置的波片层和偏振片层中，被偏振片层阻挡，具体可以参考前述图8、图10、图12所示的实施例，此处不再赘述。
在上述实施例中，扫描装置包含多个层。多个层之间的连接方式是胶合、咬合、连接件固定等方式。下面示例性地列举几种层级之间的连接的可能情况：
情况一，扫描装置的不同层之间可以通过胶合方式来贴合。胶合是指同质或异质物体表面用胶黏剂连接在一起的技术。
如图17所示为本申请提供的一种可能的扫描装置的层连接方式示意图。其中，偏振片层通过胶合方式贴合在所述扫描器主体的反射面上，和/或，所述波片层通过胶合方式贴合在所述偏振片层上。
本申请对于胶黏剂的选择不做限定，例如，胶黏剂可以包含光学透明胶黏剂(optically clear adhesive，OCA)等。
情况二，通过施加压力使两个层级的表面吸附在一起。在一些场景中，这种方式也称为光胶。通过光胶进行胶合，能使得偏振片层和反射面之间的平面更平整，提升光的透射率，减少能耗。
可选的，这种情况下，两个层之间通过分子间作用力来贴合。
情况三，在两个层之间设置部分凹凸不同的区域，将凹凸不平的区域互相接触卡住。请参见图18，图18是本申请实施例提供的又一种可能的扫描装置的层连接方式示意图。波片层靠近偏振片层的表面具有一个凹凸不平的区域，相应的，偏振片层靠近波片层的表面也具有一个凹凸不平的区域。这两个凹凸不平的区域可以形成一个咬合区域，从而相互接触卡住，将波片层贴合与偏振片层之上。类似地，偏振片层与其下一层也可以通过咬合方式贴合。
如此，可以避免发射和接收光路中的胶黏剂影响光信号的传播方向和透射率，减少能耗且提升扫描装置的稳定性，有助于提升探测装置的探测性能。可选的，咬合区域可以设置于发射光路和接收光路以外的区域，从而避免咬合区域的凹凸界面造成光信号的能量损失，有助于提升雷达的识别精度。
情况四，使用连接件来固定多个层。具体地，连接件可以有多种可能的设计，例如可以通过位于边缘的连接件来固定多个层，或者使用包围多个层的连接件箍住多个层等。图19A和图19B是本申请实施例提供的又一些可能的扫描装置的层连接方式示意图，如图19A所示，通过在扫描装置左侧设置连接件，可以通过连接件连接波片层、偏振片层、扫描器主体等中的一项或者多项。如图19B所示，通过包围多个层的连接件，可以箍住多个层以使得波片层和偏振片层相贴，和/或，偏振片层和反射面相贴。
如此，可以避免发射和接收光路中的胶黏剂影响光信号的传播方向和透射率，减少能耗且提升扫描装置的稳定性，有助于提升探测装置的探测性能。可选的，咬合区域可以设置于发射光路和接收光路以外的区域，从而进一步降低光信号的能量损失。
应理解，具体实施过程中还可以有其他方式贴合扫描装置的不同层，本申请不再一一列举。上述多种情况在实际应用时可以进行组合，对于组合的情况此处不在赘述。
需要说明的是，在扫描装置中，不同的层与层之间的连接方式可以不同。例如，偏振片层可以通过连接件与扫描器主体连接，而波片层和偏振片层之间使用胶合方式连接。对于组合连接的方式，此处不再一一示例。
在一个具体实施例中，上述偏振片层包含偏振片，偏振片的数量可以是一个或者多个。可选的，当偏振片层包含多个偏振片时，多个偏振片的功能或者材料可以相同，也可以不同。
在一个具体实施例中，上述波片层包含波片，波片的数量可以是一个或者多个。例如， 波片层可以包含一个四分之一波片。
可选的，当波片层包含多个波片时，多个波片的功能或者材料可以相同，也可以不同。作为一种可能的实施方式，上述波片层可以包含四分之一波片和二分之一波片。上述实施方式中，“1/2波片+1/4波片”的组合具有消色散的效果，即使在高温(或低温)情况下、在光信号的波长产生偏移时，鬼像也能够被消除，有助于提升激光雷达的识别精度。
图20A和图20B所示是本申请实施例提供的又一种可能的扫描装置的结构示意图。如图20A所示，波片层可以包含一个四分之一波片，偏振片层可以包含一个偏振片。如图20B所示，波片层可以包含一个四分之一波片和一个二分之一波片，偏振片层可以包含一个偏振片。其中，二分之一波片可以贴合偏振片层，四分之一波片可以贴合二分之一波片。当然，波片层的多个波片的设置顺序可以有其他设计，例如四分之一波片可以贴合偏振片层，二分之一波片可以贴合四分之一波片，本申请对多种设置顺序不再一一列举。
在一个具体实施例中，第一角度与第二角度的差值小于或等于第一阈值，第一角度为所述偏振片层的偏振方向与波片层的光轴方向的夹角，所述第二角度为45°。例如，第一阈值可以为0.2°，即：偏振片层的偏振方向和1/4波片的光轴方向(或1/4波片和1/2波片的等效光轴方向)的夹角为45°±0.2°。如此，可以使得经过偏振片后入射波片的线偏光可以尽可能被转换为圆偏光，从而提高偏振片层对视窗返回的光信号的阻挡效果，减少鬼像的产生，减弱干扰信号的强度，有助于提升激光雷达的识别精度。
在一个具体实施例中，波片层的第一表面上存在增透膜。如此，可以提升光信号透过波片层的概率，减少光信号的损耗，提升信号有效性，有助于提升探测装置的识别精度。
可选的，第一表面可以为远离所述扫描器主体的表面。
在一个具体实施例中，反射面包含基底，基底的材料为反光材料，例如，基底可以为金属(以下称为金属基底)。以下以金属基底为例进行描述，图21所示是本申请实施例提供的又一种可能的扫描装置的结构示意图，扫描装置的反射面由金属基底来提供。
应理解，图21所示的实施例中，基底可以设置于扫描器主体之上。在一些场景中，基底也可以作为扫描器主体。例如，图22所示是本申请实施例提供的又一种可能的扫描装置的结构示意图，扫描装置的反射面和扫描器主体都通过金属基底来提供。
在一个具体实施例中，反射面包含基底和反射镀膜，所述反射镀膜贴合在所述基底的表面上。反射镀膜可以反射光信号，扫描装置反射面由反射镀膜来提供，而基底用于承载该反射镀膜。可选的，基底的材料可以包含玻璃、晶体、无机矿物质、或金属等材料。
图23所示是本申请实施例提供的又一种可能的扫描装置的结构示意图，其中，基底上承载的反射镀膜形成了反射面。应理解，图23所示的实施例中，基底可以设置于扫描器主体之上。在一些场景中，基底也可以作为扫描器主体。例如，图24所示是本申请实施例提供的又一种可能的扫描装置的结构示意图，反射面由反射镀膜来提供，而基底除了承载反射镀膜，还可以作为扫描器主体。
本申请实施例还提供一种激光雷达，该激光雷达包含扫描器、激光发射器和接收器，激光发射器用于产生发射信号，接收器用于探测光信号，扫描器包含前述实施例所描述的扫描装置，例如图4、图11、图13、图14、图15、图16、图17、图18、图19A、图19B、图20A、图20B、图21、图22、或图23所示实施例的扫描装置，或者其可能设计。
一种可能的实施方式中，该激光雷达还包括视窗，由所述视窗反射回来的光信号被扫描装置中的偏振片层阻挡，来自所述激光雷达的视野内物体反射回来的光信号被所述扫描装置 提供给所述接收器。
可替换的，上述视窗可以替换为激光雷达中的其他光学元件。
可替换的，上述激光雷达还可以替换为其他光探测装置，例如融合探测装置等。
本申请实施例还提供一种终端，终端包含前述的探测装置，例如探测装置30，或上述的激光雷达。该终端(或具体为终端中的探测装置)包含前述实施例所描述的扫描装置，例如图4、图11、图13、图14、图15、图16、图17、图18、图19A、图19B、图20A、图20B、图21、图22、图23、或图24所示实施例的扫描装置，或者其可能设计。
请参见图25，图25是本申请实施例提供的一种可能的终端250的结构示意图，终端250包含处理器2501和前述的探测装置30。处理器2501和探测装置30之间可以进行连接，或者进行通信，本申请实施例对于连接、通信的具体实施方式不做限制。
处理器用于根据探测装置30的接收模块所接收的返回信号，得到关于视场中物体的探测数据。这些探测数据具体可以为视场范围对应的点云数据，或者，探测数据可以包含视场范围中的目标的距离、方位、目标所占用的像素区域、高度、速度、姿态或形状信息等中的一项或者多项。
可选的，处理器2501是进行算术运算和/或逻辑运算的模块，具体可以包含以下装置中的一项或者多项：中央处理器(central processing unit，CPU)、应用处理器(application processor，AP)、时间数字转换器(Time-to-Digital Converter,TDC)、滤波器、图形处理器(graphics processing unit，GPU)、微处理器(microprocessor unit，MPU)、专用集成电路(Application Specific Integrated Circuit，ASIC)、图像信号处理器(image signal processor，ISP)、数字信号处理器(digital signal processor，DSP)、现场可编程逻辑门阵列(Field Programmable Gate Array，FPGA)、复杂可编程逻辑器件(Complex programmable logic device，CPLD)、协处理器(协助中央处理器完成相应处理和应用)、微控制单元(Microcontroller Unit，MCU)、和/或神经网络处理器(neural-network processing unit，NPU)等。
可选的，上述终端可以包含车辆、船舶、飞机、火车、航天器、无人机、机器人等移动平台或运输工具。
本申请实施例还可以应用于智能汽车技术领域，如车辆外联(vehicle to everything，V2X)、车间通信长期演进技术(Long Term Evolution-vehicle，LTE□V)、车辆□车辆(vehicle to vehicle，V2V)等。
在本申请的描述中，术语“中心”、“上”、“下”、“垂直”、“水平”、“内”、“外”等指示的方位或位置关系为基于附图所示的方位或位置关系，仅是为了便于描述本申请和简化描述，而不是指示或暗示所指的装置或元件必须具有特定的方位、以特定的方位构造和操作，因此不能理解为对本申请的限制。
在本申请的描述中，需要说明的是，除非另有明确的规定和限定，术语“连接”应做广义理解，例如可以是固定连接，也可以是可拆卸连接，还可以是抵触连接或一体的连接；对于本领域的普通技术人员而言，可以具体情况理解上述术语在本申请中的具体含义。
本申请实施例中，“示例性的”或者“例如”等词用于表示作例子、例证或说明。本申请中被描述为“示例性的”或者“例如”的任何实施例或设计方案不应被解释为比其他实施例或设计方案更优选或更具优势。确切而言，使用“示例性的”或者“例如”等词旨在以具体方式呈现相关概念。
本申请中实施例提到的“至少一个”是指一个或者多个，“多个”是指两个或两个以上。“以下至少一项(个)”或其类似表达，是指的这些项中的任意组合，包括单项(个)或复数 项(个)的任意组合。例如，a、b、或c中的至少一项(个)，可以表示：a、b、c、(a和b)、(a和c)、(b和c)、或(a和b和c)，其中a、b、c可以是单个，也可以是多个。“和/或”，描述关联对象的关联关系，表示可以存在三种关系，例如，A和/或B，可以表示：单独存在A、同时存在A和B、单独存在B这三种情况，其中A、B可以是单数或者复数。字符“/”一般表示前后关联对象是一种“或”的关系。
以及，除非有相反的说明，本申请实施例使用“第一”、“第二”等序数词是用于对多个对象进行区分，不用于限定多个对象的顺序、时序、优先级或者重要程度。例如，第一光信号和第二光信号，只是为了便于描述，而并不是表示这第一光信号和第二光信号的来源、顺序、重要程度等的不同，在某些实施例中，第一光信号和第二光信号还可以是同一个光信号。
上述实施例中所用，根据上下文，术语“当……时”可以被解释为意思是“如果……”或“在……后”或“响应于确定……”或“响应于检测到……”。以上所述仅为本申请的可选实施例，并不用以限制本申请，凡在本申请的构思和原则之内，所作的任何修改、等同替换、改进等，均应包含在本申请的保护范围之内。
本领域普通技术人员可以理解实现上述实施例的全部或部分步骤可以通过硬件来完成，也可以通过程序来指令相关的硬件完成，所述的程序可以存储于一种计算机可读存储介质中，上述提到的存储介质可以是只读存储器，磁盘或光盘等。

Claims (22)

  1. 一种扫描装置，其特征在于，
    所述扫描装置包括扫描器主体、偏振片层、波片层，所述扫描器主体具有至少一个反射面，所述扫描器主体的反射面上贴合有偏振片层，所述偏振片层上贴合有波片层。
  2. 根据权利要求1所述的扫描装置，其特征在于，所述偏振片层通过胶合方式贴合在所述扫描器主体的反射面上。
  3. 根据权利要求1或2所述的扫描装置，其特征在于，所述波片层通过胶合方式贴合在所述偏振片层上。
  4. 根据权利要求1-3任一项所述的扫描装置，其特征在于，
    入射光信号依次入射所述波片层、偏振片层，被所述反射面反射后依次从所述偏振片层和所述波片层出射，得到出射信号。
  5. 根据权利要求4所述的扫描装置，其特征在于，
    所述偏振片层用于阻挡所述出射信号对应的镜面反射光信号，所述镜面反射光信号为所述出射信号发生镜面反射后得到的光信号。
  6. 根据权利要求4所述的扫描装置，其特征在于，所述偏振片层用于阻挡第一反射光信号、以及透过第二反射光信号，其中，所述第一反射光信号由视窗反射所述出射信号得到，所述第二反射光信号由所述扫描装置的视野内的物体反射所述出射信号得到。
  7. 根据权利要求1-6任一项所述的扫描装置，其特征在于，
    来自激光发射器的第一光信号依次经过所述波片层、偏振片层，得到第二光信号，所述第二光信号与所述偏振片层的偏振方向平行；
    所述第二光信号由所述至少一个反射面反射后，经过所述偏振层得到第三光信号所述第三光信号的偏振方向与所述偏振片层的偏振方向平行；
    所述第三光信号经过所述波片层得到第四光信号，所述第四光信号的偏振方向为圆偏振；
    所述第四光信号对应的返回信号包含第五光信号和第六光信号，其中，所述第五光信号为所述第四光信号经过镜面反射得到的光信号，所述第六光信号为所述第四光信号经过漫反射得到的光信号，所述第五光信号的偏振方向为圆偏振；
    所述第五光信号入射所述波片层、被所述波片层转换为第七光信号，所述第七光信号入射所述偏振片层，所述第七光信号被所述偏振片层阻挡，所述第七光信号的偏振方向与所述偏振片层的偏振方向垂直；
    所述第六光信号入射所述波片层，透过所述波片层入射所述偏振片层，所述第六光信号中偏振方向与所述偏振片层的偏振方向垂直的光信号被所述偏振片层阻挡，所述第六光信号中偏振方向与所述偏振片层的偏振方向平行的光信号透过所述偏振片层，得到第八光信号；
    所述第八光信号被所述至少一个反射面反射，并依次透过所述偏振层、所述波片层后被提供给接收器。
  8. 根据权利要求7所述的扫描装置，其特征在于，所述第五光信号由视窗反射所述出射信号得到，所述第六光信号由所述扫描装置的视野内的物体反射所述出射信号得到。
  9. 根据权利要求1-6任一项所述的扫描装置，其特征在于，所述扫描器主体包含第一部分和第二部分，所述第一部分和所述第二部分沿活动轴排布，所述偏振片层贴合于所述扫描器主体的所述第一部分的反射面上，所述扫描器主体的所述第二部分的反射面上不设置所述偏振片层。
  10. 根据权利要求9所述的扫描装置，其特征在于，
    来自激光发射器的第一光信号依次经过所述波片层、偏振片层，得到第二光信号，所述第二光信号与所述偏振片层的偏振方向平行；
    所述第二光信号由所述第一部分的反射面反射后，经过所述偏振层得到第三光信号所述第三光信号的偏振方向与所述偏振片层的偏振方向平行；
    所述第三光信号经过所述波片层得到第四光信号，所述第四光信号的偏振方向为圆偏振；
    所述第四光信号对应的返回信号包含第九光信号和第十光信号，其中，所述第九光信号为所述第四光信号经过镜面反射得到的光信号，所述第十光信号为所述第四光信号经过漫反射得到的光信号，所述第九光信号的偏振方向为圆偏振；
    所述第九光信号入射所述波片层、被所述波片层转换为第十一光信号，所述第十一光信号入射所述偏振片层，所述第十一光信号被所述偏振片层阻挡，所述第十一光信号的偏振方向与所述偏振片层的偏振方向垂直；
    所述第十光信号照射到所述扫描器主体的第二部分的反射面，被所述扫描器主体的第二部分的反射面反射，得到第十二光信号，所述第十二光信号被提供给接收器。
  11. 根据权利要求10所述的扫描装置，其特征在于，所述第九光信号由视窗反射所述出射信号得到，所述第十光信号由所述扫描装置的视野内的物体反射所述出射信号得到。
  12. 根据权利要求1-11任一项所述的扫描装置，其特征在于，所述波片层包含四分之一波片。
  13. 根据权利要求1-12任一项所述的扫描装置，其特征在于，所述波片层包含四分之一波片和二分之一波片。
  14. 根据权利要求1-13任一项所述的扫描装置，其特征在于，所述反射面包含基底，所述基底的材料为金属。
  15. 根据权利要求1-14任一项所述的扫描装置，其特征在于，所述反射面包含基底和反射镀膜，所述反射镀膜贴合在所述基底的表面上。
  16. 根据权利要求15所述的方法，其特征在于，所述基底的材料为玻璃或晶体。
  17. 根据权利要求1-16任一项所述的扫描装置，其特征在于，第一角度与第二角度的差值小于或等于第一阈值，所述第一角度为所述偏振片层的偏振方向与所述波片层的光轴方向的夹角，所述第二角度为45°。
  18. 根据权利要求1-17任一项所述的扫描装置，其特征在于，所述波片层的第一表面上存在增透膜，所述第一表面为远离所述扫描器主体的表面。
  19. 一种激光雷达，其特征在于，所述激光雷达包含扫描器、激光发射器和接收器，所述激光发射器用于产生发射信号，所述接收器用于探测光信号，所述扫描器包含如权利要求1-18任一项所述的扫描装置。
  20. 根据权利要求19所述的激光雷达，其特征在于，所述激光雷达还包括视窗，由所述视窗反射回来的光信号被所述扫描装置中的偏振片层阻挡，来自所述激光雷达的视野内物体反射回来的光信号被所述扫描装置提供给所述接收器。
  21. 一种终端，其特征在于，所述终端包含权利要求1-17中任一项所述的扫描装置，或者，所述终端包含如权利要求19或20所示的激光雷达。
  22. 根据权利要求21所述的终端，其特征在于，所述终端为车辆、无人机或者机器人。
PCT/CN2022/095360 2022-05-26 2022-05-26 一种扫描装置、激光雷达和终端 WO2023225963A1 (zh)

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