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WO2023040377A1 - Radar laser - Google Patents

Radar laser Download PDF

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Publication number
WO2023040377A1
WO2023040377A1 PCT/CN2022/098405 CN2022098405W WO2023040377A1 WO 2023040377 A1 WO2023040377 A1 WO 2023040377A1 CN 2022098405 W CN2022098405 W CN 2022098405W WO 2023040377 A1 WO2023040377 A1 WO 2023040377A1
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Prior art keywords
unit
light
optical system
echo
array
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PCT/CN2022/098405
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English (en)
Chinese (zh)
Inventor
吴世祥
向少卿
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Hesai Technology Co Ltd
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Hesai Technology Co Ltd
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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
    • G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
    • G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
    • G01S17/06—Systems determining position data of a target
    • G01S17/08—Systems determining position data of a target for measuring distance only
    • 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

  • the invention relates to the field of optical ranging, in particular to laser radar.
  • Lidar is a detection device that calculates the distance of an object by emitting a laser and detecting the echo signal reflected after the laser reaches the surface of the object.
  • Ranging performance is an important technical indicator of lidar, which mainly depends on the signal-to-noise ratio level of the lidar system, and ambient light is an important source of noise that affects the level of lidar signal-to-noise ratio, so reducing ambient light has always been a An important link in the design of the optical system of the laser radar.
  • the focal length of the optical system at the receiving end needs to match the focal length of the transmitting end, the effective size of the laser, and the photodetector.
  • the focal length of the optical system will have a greater impact on the overall volume of the lidar. Therefore, whether it is a mechanical radar or a solid-state radar, the focal length of most optical systems at the receiving end is within 100mm.
  • SiPMs silicon photomultipliers
  • SiPMs silicon photomultipliers
  • the optical system at the receiving end if a large-sized detector is used and compressed to a small field of view, an optical system with a long focal length is required; however, the use of a long focal length optical system is not conducive to the realization of a compact and small laser radar.
  • the height of the detector 101 shown in FIG. 1 is L
  • f is the focal length of the receiving lens 102 (equivalently shown as a convex lens)
  • ⁇ is the field of view angle.
  • the field of view here is an instantaneous field of view (Instantaneous Field Of View, IFOV), which refers to a light receiving angle or an observation field of view of a single photodetector.
  • IFOV Instantaneous Field Of View
  • the formula for calculating the field of view angle can be obtained as It can be seen from this formula that if a detector 101 with a large photosensitive surface is used (such as when SiPM is used), the height L will be larger, and in order to limit the field of view angle ⁇ of the detector 101 to avoid receiving more ambient light and make the detection If the filter 101 is saturated, it is necessary to increase the focal length f of the optical system at the receiving end.
  • an aperture stop 203 is added to the optical system at the receiving end to suppress ambient light. Specifically, as shown in the figure, by setting an aperture stop 203 between the receiving lens 202 and the detector 201, the aperture stop 203 is located at the focus position of the receiving lens 202, and the light passing through the aperture stop 203 covers the detector 201 The entire effective area (the coverage height L is taken as an example in the figure).
  • the aperture diaphragm is an additional optical component, which increases the cost on the one hand, and increases the installation and debugging work on the other hand.
  • the bandwidth of the filter is affected by factors such as the bandwidth of the laser and the temperature of the working environment.
  • the space for further compression of the filter bandwidth is relatively limited, and the ambient light cannot be controlled to an ideal level.
  • the present invention provides a laser radar, which can suppress the influence of ambient light on the detector, improve the dynamic range of the laser radar during detection, and improve the ranging capability of the laser radar.
  • the first aspect of the present invention provides a laser radar, including: a light emitting unit for transmitting a detection light signal; a light receiving unit for receiving the echo light generated by the detection light signal signal; the main optical system, configured between the light emitting unit and the light receiving unit, is used to receive the detection light signal and transmit it to the outside; and is used to receive the echo light signal and transmit it to the light receiving unit; the expansion A beam unit, arranged between the main optical system and the light receiving unit, is used to receive the echo optical signal passing through the main optical system and transmit it to the light receiving unit after beam expansion; wherein, the main optical system and the beam expander
  • the equivalent focal length of the unit combination is greater than the focal length of the main optical system, so as to compress the viewing angle of the light receiving unit.
  • the transmission path of the detection optical signal is partly the same as the transmission path of the echo optical signal.
  • the main optical system includes: a positive lens unit and a spectroscopic unit; the positive lens unit is used to receive the detection light signal from the spectroscopic unit and transmit it outward; and is used to receive the the echo optical signal and transmit it to the spectroscopic unit; the spectroscopic unit is used to receive the detection optical signal and transmit it to the positive lens unit; and is used to receive the echo optical signal from the positive lens unit and transmit it to the positive lens unit.
  • the light receiving unit transmits.
  • the distance between the beam expander unit and the positive lens unit is smaller than the focal length of the positive lens unit.
  • the photosensitive surface of the light receiving unit is located at the focal plane of the combination of the main optical system and the beam expander unit.
  • the equivalent focal length is further greater than the distance between the main plane of the main optical system and the light-sensing surface of the light-receiving unit.
  • the spectroscopic unit includes: a reflective unit, including a reflective part, for reflecting one of the echo optical signal and the detection optical signal; the reflective unit further includes a transmissive part or the reflective unit An external gap is fitted for passing the other of the probe light signal and the echo light signal.
  • the main optical system further includes: a polarizing unit, which is arranged on the side of the positive lens unit facing away from the beam splitting unit, and is used to change the polarization of the detection light signal and the return light signal. Polarization state, so that the output detection optical signal is in the first polarization state, and the output echo optical signal is in the second polarization state, the first polarization state is different from the second polarization state; the light splitting unit is set Between the positive lens unit and the beam expander, it is configured to allow the echo light signal of the second polarization state to pass through.
  • the lidar further includes: a scanning unit, which can be rotated in one or two dimensions, and is used to rotate to a predetermined posture so that the detection light signal is outward at a corresponding scanning angle transmission, and the echo optical signal corresponding to the detection optical signal is transmitted to the primary optical system.
  • a scanning unit which can be rotated in one or two dimensions, and is used to rotate to a predetermined posture so that the detection light signal is outward at a corresponding scanning angle transmission, and the echo optical signal corresponding to the detection optical signal is transmitted to the primary optical system.
  • the light receiving unit includes: a photodetector array; the beam expanding unit includes an array of sub-beam expanding units, wherein each sub-beam expanding unit corresponds to one or more photodetectors.
  • the photodetectors corresponding to the first sub-beam expanders in the middle region of the sub-beam expander array correspond to the central field of view angle of the field of view of the lidar
  • each of the first sub-beam expanders A sub-beam expander unit includes a non-eccentric lens
  • the photodetectors corresponding to the second sub-beam expander units in the peripheral area other than the central area of the sub-beam expander unit array correspond to the edge outside the central field of view angle of the lidar
  • each of the second sub-beam expanders includes a decentered lens.
  • the sub-beam expander array is a microlens array for packaging a photodetector array.
  • the photodetector array includes: a circuit substrate having a first surface on which the photodetector array is disposed; an optical carrier having a second surface on which the microlens array is disposed, and The circuit substrate is packaged in one body and the second surface is opposite to the first surface, so that each of the microlenses is arranged corresponding to each of the photodetectors.
  • the light receiving unit includes: the light receiving unit includes: a plurality of photodetector arrays, and each photodetector array is arranged in a linear array; the beam expanding unit includes at least one A cylindrical negative lens, the cylindrical negative lens is arranged corresponding to part or all of the light detector array in the light receiving unit, and the extension direction of the cylindrical negative lens is the length direction of the light detection array.
  • the long focal length optical system is realized through the combination of the main optical system and the beam expander unit, which is applied to the laser radar, and can realize the longer focal length of the light receiving unit in a relatively compact volume.
  • the long focal length optical system can greatly reduce the influence of ambient light on the detector when using a detector with a larger photosensitive surface size (such as SiPM), and still keep the lidar compact.
  • a detector with a larger photosensitive surface size (such as SiPM) can be used to have more photosensitive units, thereby improving the dynamic range of the detection system. Therefore, whether the optical system in the embodiment of the present invention reduces the influence of ambient light or improves the dynamic range, it plays a crucial role in the ranging performance of the lidar.
  • FIG. 1 shows a schematic diagram of the relationship among detector size, field of view and focal length in an example.
  • FIG. 2 shows a schematic diagram of the principle of a lidar using an aperture stop to suppress ambient light in an example.
  • FIG. 3 shows a schematic structural diagram of the optical system of the laser radar in an embodiment of the present invention.
  • FIG. 4 shows a schematic diagram of the principle of an optical system in an embodiment of the present invention.
  • FIG. 5A and FIG. 5B respectively show the structural schematic diagrams of the optical system of the two-dimensional scanning laser radar for realizing light splitting based on the polarization splitting unit in different embodiments of the present invention.
  • FIG. 6 and FIG. 7 respectively show the structural schematic diagrams of the optical system of the two-dimensional scanning laser radar based on the reflection unit to realize light splitting in different embodiments of the present invention.
  • FIG. 8A shows a schematic structural diagram of realizing positive-negative lens combination in another embodiment of the present invention.
  • FIG. 8B shows a schematic diagram of the three-dimensional structure of the positive-negative lens combination in FIG. 8A .
  • FIG. 9A shows a schematic structural diagram of an arrangement of photodetector arrays in an embodiment of the present invention.
  • FIG. 9B shows a schematic structural diagram of another arrangement of photodetector arrays in an embodiment of the present invention.
  • FIG. 10 shows a schematic diagram of the arrangement structure between the negative lens array and the photodetector array in the embodiment of the present invention.
  • FIG. 11A and FIG. 11B respectively show structural schematic diagrams of optical systems using negative lens arrays as beam expanders in different embodiments of the present invention.
  • FIG. 12A and FIG. 12B respectively show the structural diagrams of the arrangement of the negative lens array adapted to the photodetector array in different embodiments of the present invention.
  • FIG. 13 shows a schematic structural diagram of the photodetector array and the microlens array package in an embodiment of the present invention.
  • Embodiments of the present invention are described below through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.
  • the present invention can also be implemented or applied in different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applied systems without departing from the spirit of the present invention. It should be noted that, in the case of no conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.
  • first, second, etc. are used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, the first interface and the second interface are described. Furthermore, as used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context indicates otherwise. It should be further understood that the terms “comprising”, “comprising” indicate the presence of stated features, steps, operations, elements, components, items, species, and/or groups, but do not exclude one or more other features, steps, operations, The existence, occurrence or addition of an element, component, item, species, and/or group.
  • Relative spatial terms denoting "below”, “upper”, etc. may be used in order to more easily explain the relationship of one device relative to another device illustrated in the drawings. Such terms mean not only the meaning indicated in the drawings but also other meanings or operations of the device in use. For example, if the device in the figures is turned over, elements described as “under” other elements would then be oriented “above” the other elements. Therefore, the exemplary term “under” includes all above and below. The device may be rotated by 90° or at other angles, and relative spatial terms are to be construed accordingly.
  • the optical system of the lidar has the problem of ambient light interference, especially in the case of the distance measurement capability based on the lidar, a larger photodetector (such as SiPM) will be selected, and the corresponding field of view will be larger. It means that there are more angles that can receive interfering ambient light. For this reason, in the current lidar, the improvement of the above two aspects of suppressing ambient light has been carried out, but the volume of the lidar product will be limited, making it difficult to set a suitable focal length, and it is necessary to add optical devices such as aperture diaphragms to achieve this.
  • the focal length of the optical system is extended. The other is to compress the field of view angle of the photodetector by compressing the bandwidth of the filter, but there is a problem of being limited by the physical configuration parameters of the lidar.
  • an improved lidar structure is provided in an embodiment of the present invention.
  • FIG. 3 it shows a schematic structural diagram of an optical system of a lidar in an embodiment of the present invention.
  • the lidar 300 includes: a light emitting unit 301 , a light receiving unit 302 , a main optical system 303 and a beam expanding unit 304 .
  • the light transmitting unit 301 is configured to transmit a detection light signal, and may also be referred to as a transmitting end.
  • the light emitting unit 301 may include a light emitter array, which includes a plurality of light emitters arranged in a two-dimensional planar array or a one-dimensional linear array.
  • Each optical transmitter can be an edge-emitting semiconductor laser (Edge-Emitting semiconductor Lasers, EEL) or a vertical-cavity surface-emitting laser (Vertical-Cavity Surface-Emitting Laser, VCSEL).
  • the light receiving unit 302 is configured to receive the echo light signal generated by the detection light signal, and the detection light signal can be irradiated on the surface of the obstacle and reflected to form the echo light signal; the light receiving unit 302 can also called the receiver.
  • the light receiving unit 302 may include a photodetector array, which includes a plurality of photodetectors arranged in a two-dimensional planar array or a one-dimensional linear array. Each photodetector can be a silicon photomultiplier (SiPM) or a single photon avalanche diode (SPAD) or the like.
  • the main optical system 303 is configured between the light emitting unit 301 and the light receiving unit 302, and is used to receive the detection light signal and transmit it to the outside; and is used to receive the echo light signal and transmit it to the light receiving unit 302 transmission.
  • the first transmission path J of the detection optical signal is partly the same as the second transmission path K of the echo optical signal, that is, the main optical system 303 is an optical system with coaxial transmission and reception.
  • the main optical system 303 includes a positive lens unit 331 and a beam splitting unit 332 .
  • the light beam transmission path between the positive lens unit 331 and the light splitting unit 332 is shared by the first transmission path J and the second transmission path K, wherein J is indicated by the arrow along the thinner black solid line, and K is indicated by the thicker shaded arrow as instructed.
  • the positive lens unit 331 is used to receive the detection light signal from the light splitting unit 332 and transmit it to the direction outside the lidar 300 , and to receive the echo light signal and transmit it to the light splitting unit 332 .
  • the positive lens unit 331 can converge the received detection light signal to be collimated and then transmitted outward, specifically, it can be output to the scanning unit 305 as shown in the figure and transmitted to the outside of the laser radar 300 through the scanning unit 305;
  • the positive lens unit 331 can also converge the echo light signal and then transmit it to the light receiving unit 302 , specifically, it can receive the echo light signal from the scanning unit 305 as shown in the figure.
  • the scanning unit 305 can be rotated one-dimensionally or two-dimensionally, and is used to rotate to a predetermined posture so that the detection light signal is transmitted outward at a corresponding scanning angle, and is used to correspond to the detection light signal.
  • the echo optical signal is transmitted to the main optical system 303 .
  • the scanning unit 305 may include any one of a vibrating mirror, a MEMS mirror, and a rotating mirror.
  • the light splitting unit 332 transmits the detection light signal and the return light signal between the light emitting unit 301 , the light receiving unit 302 and the positive lens unit 331 .
  • the detection light signal is transmitted along the direction of the first transmission path J indicated by the thin black solid arrow
  • the light splitting unit 332 receives the detection light signal of the light emitting unit 301 and transmits it to the positive lens unit 331
  • the echo light signal is transmitted along the direction of the second transmission path K indicated by the thicker shaded arrow
  • the light splitting unit 332 receives the echo light signal from the positive lens unit 331 and transmits it to the light receiving unit 302 .
  • the light splitting unit 332 can split the detection light signal and the echo light signal by deflection or transmission.
  • the light splitting unit 332 transmits the echo light signal, and deflects (eg reflects) the detection light signal before transmission.
  • the optical system may also be configured with the light splitting unit 332 deflecting the received echo light signal before transmitting it, and transmitting the received detection light signal.
  • the beam expanding unit 304 is arranged between the main optical system 303 and the light receiving unit 302 , and is used for receiving the echo light signal passing through the main optical system 303 and transmitting it to the light receiving unit 302 after beam expansion.
  • the beam expander unit 304 corresponds to the negative lens unit in the embodiment of FIG. 3 , and may be realized by a negative lens or a negative lens group. Through the combination of the positive lens unit 331 and the negative lens unit, the focal length of the receiving end optical system in the lidar 300 is elongated.
  • the light splitting unit 332 may be an optical component that passes optical signals of a specific polarization state, and does not pass optical signals of other polarization states. In a specific example, by making the detection light signal and the echo light signal have different polarization states, the light splitting unit 332 allows the echo light signal of a specific polarization state to pass, while preventing the detection light signal of other polarization states from passing.
  • the main optical system 303 further includes a polarization unit, which is arranged on the side of the positive lens unit 331 facing away from the light splitting unit 332, for for changing the polarization states of the probe optical signal and the echo optical signal, so that the output probe optical signal is in a first polarization state, and the output echo optical signal is in a second polarization state, the first polarization state is different from in the second polarization state; correspondingly, the light splitting unit 332 is disposed between the positive lens unit 331 and the beam expander unit 304 and is configured to allow the echo light signal of the second polarization state to pass through.
  • a polarization unit which is arranged on the side of the positive lens unit 331 facing away from the light splitting unit 332, for for changing the polarization states of the probe optical signal and the echo optical signal, so that the output probe optical signal is in a first polarization state, and the output echo optical signal is in a second polarization state, the first polarization state is different from in the second polarization state
  • the spectroscopic unit 332 can also be implemented by a reflective unit, which can include a reflective part for reflecting one of the echo optical signal and the detection optical signal, and the reflective unit also includes a transmissive part (Refer to the embodiment in FIG. 7 for details) or the reflective unit is equipped with an external gap (refer to the embodiment in FIG. 6 for details), so as to allow the other of the detection optical signal and the echo optical signal to pass through, for example transmission.
  • a reflective unit which can include a reflective part for reflecting one of the echo optical signal and the detection optical signal, and the reflective unit also includes a transmissive part (Refer to the embodiment in FIG. 7 for details) or the reflective unit is equipped with an external gap (refer to the embodiment in FIG. 6 for details), so as to allow the other of the detection optical signal and the echo optical signal to pass through, for example transmission.
  • FIG. 4 a schematic structural diagram of an optical system in an embodiment of the present invention is shown.
  • the optical system in Figure 4 can be applied to the receiving end of lidar.
  • the optical system includes a combination of a positive lens 401 and a negative lens 402 .
  • the focal length of the positive lens 401 is f1
  • the field angle is ⁇
  • the focal point is A.
  • the viewing angle of the negative lens 402 is ⁇ .
  • the light through the positive lens 401 should converge at point A, but after the negative lens 402 is set between the main plane of the positive lens 401 and the focal point A of the positive lens 401, due to the dilation effect of the negative lens 402 on the light, the convergent point of the light is Move far away from point A to point B, and the field of view becomes ⁇ , ⁇ is smaller than ⁇ .
  • the positive lens 401 and the negative lens 402 are combined to form an equivalent lens, the distance between the main plane and the converging point B is f, that is, the focal length of the equivalent lens is f.
  • f is extended compared to f1.
  • the distance between the positive lens 401 and the negative lens 402 is constant (for example, the distance between the principal planes of the two is smaller than the focal length of the positive lens 401)
  • the combination of the positive lens 401 and the negative lens 402 can increase the focal length of the optical system.
  • the distance L between the main plane of the positive lens 401 and the focal plane where the B point is is the physical length of this optical system, and f is greater than L, which shows that The equivalent focal length f of the equivalent lens also exceeds the limitation of the physical size of the optical system.
  • positive lens 401 and the negative lens 402 in the illustration are only simplified representations, and may be equivalent representations of lens groups in practical applications, and are not limited by the illustration.
  • this optical system can not only effectively extend the focal length and obtain a focal length beyond the physical size limit, but also keep the structure of the laser radar compact, thereby effectively solving the problems in the prior art and eliminating the need for an aperture stop.
  • the original optical system on the receiving end side of the laser radar includes a lens group for converging echo light signals, which corresponds to the positive lens 401 in FIG. 4 . Therefore, it is only necessary to arrange a negative lens 402 between this lens group and the photodetector or a lens group that realizes the negative lens 402, and the focal length of the receiving end can be greatly extended.
  • the photosensitive surface of SiPM is more than twice as large), according to f can be increased with the increase of L to limit the field of view ⁇ to suppress the interference of ambient light, thereby avoiding the saturation of the photodetector.
  • FIG. 5A and FIG. 5B schematic structural diagrams of the optical system of the two-dimensional scanning laser radar for splitting light based on the polarization beam splitting unit in different examples of the present invention are respectively shown.
  • the laser radar includes: an optical emitter array 501, an optical detector array 502, a positive lens 503 (equivalent representation, which can be realized by a lens group), a negative lens 504 (equivalent representation, which can be realized by a lens group), a polarization splitter, Quarter wave plate 506 , mirror 507 and scanner 508 .
  • 5A and 5B are specific implementation examples based on the embodiment in FIG. 4
  • the light emitter array 501 and the light detector array 502 respectively correspond to the example implementations of the light emitting unit and the light receiving unit in the embodiment in FIG. 4
  • the positive lens 503 and the negative lens 504 respectively correspond to the example realization of the positive lens 503 unit and the negative lens 504 unit in FIG.
  • the polarization splitting device corresponds to an example implementation of the splitting unit in the embodiment of FIG. 4, and the quarter-wave plate 506 corresponds to the polarization unit in the embodiment of FIG. 4, and the quarter-wave plate 506 can be used to change the passing optical signal polarization state.
  • Scanner 508 corresponds to an example implementation of the scanning unit in FIG. 4 .
  • FIG. 5A The main difference between FIG. 5A and FIG. 5B is that the polarization beam splitting device in FIG. 5A is implemented as a polarization beam splitting prism 505A, and the polarization beam splitting device in FIG. 5B is implemented as a polarization beam splitting plate 505B.
  • the light emitter array 501 emits a laser beam, and part of the polarized light is reflected by the polarization beam splitting device, collimated by the positive lens 503, and passes through the quarter-wave plate 506 Change to the first polarization state, reflected by the mirror 507, and then scanned by the scanner 508 to irradiate the target in the corresponding field of view, the target reflects the laser beam to form an echo optical signal; the echo optical signal returns to the laser radar, and is Reflected by scanner 508 and reflector 507, the polarization state of the laser beam will be changed to the second polarization state again through the quarter-wave plate 506.
  • the reflector 507 is used to fold the optical path to make the overall optical path structure more compact, but it is not a necessary device.
  • the beam is scanned directly by the scanner 508 .
  • the negative lens may be single, or multiple negative lenses arranged one after the other along the optical path, so as to further extend the focal length.
  • the focal length range of the optical system combined by the positive-negative lens at the receiving end can reach, for example, 100mm-300mm.
  • the transmitting end and the receiving end of the laser radar can share the positive lens, and the polarization beam splitter is located between the positive and negative lenses, and the negative lens is located at the receiving end alone and corresponding to the photodetector array, so as to realize the optical system of the receiving end with a long focal length.
  • the transmitting end can choose an optical system with a relatively short focal length to ensure that the laser light can be emitted effectively; while the receiving end can choose an optical system with a relatively long focal length; thus, a photodetector with a larger photosensitive surface can be used (eg SiPM detector) to receive.
  • SiPM with a smaller field of view, it can receive less ambient light.
  • using a larger photosensitive surface size can have more photosensitive units, thereby improving the dynamic range of the lidar.
  • LiDAR can optionally employ an array of light emitters and an array of light detectors.
  • the photodetector array can be arranged on the focal plane of the optical system, that is, the photosensitive surface of the photodetector array is located at the focal plane of the combination of the main optical system and the beam expander unit.
  • the light emitter array and photodetector array can be one-dimensional line array or two-dimensional area array, the two-dimensional area array can be arranged in matrix or multi-column staggered arrangement, one or more light emitters and corresponding One or more photodetectors constitute a detection channel, and the phototransmitters and photodetectors in the same detection channel correspondingly send the detection light signal and receive the echo light signal generated.
  • the light emitter array and the light detector array can emit light for each column and each detection channel.
  • each column may be patrolled to emit light one by one, that is, after one column is finished emitting light, it is the turn of the light emitters of each detection channel in the next column to emit light one by one.
  • all column arrays can also emit light at the same time, that is, the first channel of each column array emits light at the same time, and then the other detection channels of each column sequentially emit light at the same time in sequence.
  • the corresponding detection channels of multiple linear arrays on the same column can also emit light at the same time, for example, the first detection channels of multiple linear arrays on the same column emit light at the same time, and then similarly, multiple The other detection channels of the line array emit light at the same time in sequence according to the order of the arrangement of the columns.
  • the multiple line arrays in the same column After the multiple line arrays in the same column complete the light emission, they will patrol the light column by column, that is, multiple line arrays in one column complete the light emission, and it is the turn of multiple line arrays in the next column to emit light.
  • the line array emits light according to the above process.
  • Each photodetector in the photodetector array also cooperates with the phototransmitter of the same detection channel to work in order to receive the corresponding echo light signal according to any of the above methods.
  • the light emitting unit may also be implemented as a single laser, and the light receiving unit may also be implemented as a single photodetector, etc., and the above is not limited thereto.
  • the splitting unit in addition to the above-mentioned splitting based on the polarization splitting unit, can also be implemented by a reflecting unit, and the reflecting unit has a reflector for reflecting one of the detection optical signal and the echo optical signal. part, and may have a transmissive part or cooperate with an external gap to realize the transmission of the other of the reflected detection light signal and the echo light signal, thereby realizing light splitting.
  • the above positive-negative lens combination can also be applied to extend the focal length of the receiving end.
  • FIG. 6 and FIG. 7 schematic structural diagrams of the optical system of the two-dimensional scanning laser radar for realizing light splitting based on the reflection unit in different examples of the present invention are respectively shown.
  • the lidar includes: a light emitter array 601 , a light detector array 602 , a positive lens 603 , a negative lens 604 , a reflection unit, a mirror 606 and a scanner 607 .
  • the positive lens 603 and the negative lens 604 are still equivalent representations.
  • the difference between the embodiments shown in FIG. 6 and FIG. 7 lies in that there are differences in the realization of the reflection unit, and the corresponding changes in the positions of the sending end and the receiving end.
  • the reflection unit in FIG. 6 is implemented as a mirror 605A smaller in size than the positive lens 603
  • the reflection unit in FIG. 7 is implemented as a small hole mirror 605B.
  • the detection light signal output by the light emitter array 601 in FIG. 6 is reflected by the mirror 605A to the positive lens 603, collimated by the positive lens 603, reflected to the scanner 607 by the mirror 606, and emitted to the laser radar after being reflected by the scanner 607;
  • the corresponding echo light signal enters the laser radar, is reflected by the scanner 607 and the reflector 606 to the positive lens 603, the positive lens 603 converges the echo light signal, and the echo light signal is transmitted to the negative through the gap around the reflector 605A.
  • the lens 604 is incident to the photodetector array 602 through the negative lens 604 .
  • the detection optical signal output by the optical transmitter array 601 in Fig. 7 passes through the small hole in the middle of the aperture reflector 605B, and exits through the positive lens 603, the reflector 606, and the scanner 607; the corresponding echo optical signal enters the laser radar, passes through The scanner 607 , mirror 606 , positive lens 603 and pinhole mirror 605B are reflected to the negative lens 604 through the pinhole mirror 605B, and transmitted to the photodetector array 602 .
  • the transmissive portion of the reflector in the embodiment of FIG. 7 is a small hole for passing light; in other embodiments, the transmissive portion can also be of other shapes, not limited by the small hole; or the transmissive portion It can also be implemented in other forms, such as glass made of transparent material.
  • the implementation of the positive and negative lenses in the positive-negative lens combination can be selected.
  • the positive lens can be implemented as a biconvex lens
  • the negative lens can be implemented as a biconcave lens
  • the positive lens may be a biconvex lens, and the type of negative lens may be a cylindrical negative lens.
  • the cylindrical negative lens combined with the positive lens 801 may be a plano-concave cylindrical lens 802 .
  • FIG. 8B is a perspective view of FIG. 8A to facilitate understanding of its structure.
  • the positive-negative lens combination can maintain a short focal length in one direction (such as shown in the Y direction in Figure 8B, that is, the extension direction of the cylindrical negative lens), while achieving a long focal length in the other direction ( For example, in the Z direction in FIG. 8B, the concave surface of the cylindrical negative lens in the Z direction is used to achieve a long focal length).
  • the cylindrical negative lens may also be a biconcave negative cylindrical lens, which is not limited to this embodiment.
  • the arrangement pattern of the light-receiving unit such as the photodetector array
  • the cylindrical negative lens solution can be used.
  • a plurality of photodetectors 901 such as SiPMs are arranged at intervals along the length direction of the photodetector array.
  • the photodetector array may include: a plurality of strip-shaped photodetector linear arrays arranged along a width direction perpendicular to the length direction (refer to the Z direction in FIG.
  • the arrangement can refer to the multiple rows of photodetectors 1001 in FIG. 10 . It can be understood that in FIG. 9B , since the distance between adjacent photodetectors 901 in the length direction may be very small, if the focal length is increased in the length direction, it is easy to cause a gap between photodetectors 901 in the line array. Therefore, it is not suitable to use a long focal length system for the length direction, but for the width direction, the spacing between multiple line arrays may be large, even if the focal length is lengthened, crosstalk is relatively less likely to occur. Therefore, for example, the cylindrical negative lens solution in FIG. 8A and FIG. 8B can be used to maintain the focal length in the length direction and achieve a long focal length in the width direction, suppress ambient light, and improve the signal-to-noise ratio.
  • FIG. 10 it shows a schematic diagram of the arrangement structure between the negative lens array and the photodetector array in the embodiment of the present invention.
  • the photodetector 1001 is shown as a square, and each negative lens 1002 in the negative lens array corresponds to a photodetector 1001.
  • the circle covering each photodetector 1001 in the figure is a simple representation of the light spot 1003 of the echo optical signal.
  • the negative lens 1002 can be implemented as a concave microlens.
  • the concave microlens can be an aspheric mirror, specifically a cylindrical negative lens or a general concave lens, or a plano-concave lens or a biconcave lens.
  • each negative lens can be set corresponding to each photodetector (such as SiPM), and each negative lens 1002 can be separately set separately from each other, such as represented by a dotted line box in the figure; or, A plurality of negative lenses 1002 can also be integrally formed, that is, all (or part) of the negative lenses in the negative lens array are connected to form an optical device, etc., as shown in box 1004 in the figure, the optical device of the integrated negative lens array can be Realize a large field of view (for example, 10° to 20°).
  • aberrations at different viewing angles can be corrected by setting the type of each concave microlens in the negative lens array.
  • each concave microlens in the central area of the negative lens array (corresponding to the central field of view angle of the lidar) can be set as a non-decentralized lens, and the central area
  • Each concave microlens in the surrounding area (corresponding to the edge field angle of the lidar) is set as an eccentric lens.
  • the eccentric lens can deflect the light beam, even if the light beam at the edge position is deflected toward the middle area.
  • this structure contributes to reducing the spacing and size between photodetectors.
  • the beam expanding unit may include an array of sub-beam expanding units, wherein each sub-beam expanding unit corresponds to one or more photodetectors.
  • the beam expander unit may be a negative lens array, and each sub-beam expander unit therein is a negative lens.
  • FIG. 11A and FIG. 11B there are schematic structural diagrams of an optical system using a negative lens array 1102 as a beam expander in different examples of the present invention.
  • the Z-axis and X-axis directions in FIG. 11A and FIG. 11B may be consistent with those in FIG. 8B .
  • each negative lens 1121 may correspond to one or more photodetectors 1131 to transmit the echo optical signal of the corresponding detection channel.
  • the optical system includes: a positive lens 1101, a negative lens array 1102, and a scanner 1104.
  • the negative lens array 1102 is set corresponding to the photodetector array 1103; the scanner 1104 can be rotated in one or two dimensions to select the optical signal corresponding to the detection channel transmission.
  • the optical system of this embodiment can be applied to, for example, the embodiments shown in FIG. 5A , FIG. 5B , FIG. 6 , and FIG. 7 .
  • the optical system of the positive-negative lens combination in the embodiment of the present invention can be flexibly applied to different types of lidars, so as to extend the focal length of the receiving end to compress the field of view, thereby suppressing the environment light interference. Therefore, through this optical system, the anti-interference performance of different types of laser radar products can be improved, so as to achieve the purpose of improving the ranging performance of different types of laser radar products.
  • the arrangement of the negative lens array can also be adapted to the photodetector array.
  • FIG. 12A shows the structure of a negative lens array in an embodiment.
  • the negative lens array 1200A can be adapted to include a plurality of strip-shaped concave microlenses 1201A (such as cylindrical concave lenses) along a specific direction.
  • each concave microlens 1201A can correspond to cover a row of photodetectors, a row of photodetector arrays composed of several photodetectors, or a row of photodetectors composed of photodetectors and the photodetector array arranged at intervals,
  • the photodetector array is, for example, the photodetector array shown in FIG. 9B
  • the distance between each photodetector, each photodetector array, or each photodetector and photodetector array in each row can be as small as possible.
  • FIG. 12B it shows the structure of the negative lens array in another embodiment.
  • the negative lens array 1200B includes a plurality of concave microlenses 1201B arranged at intervals, and each concave microlens 1201B can correspond to cover a photodetector or A photodetector array composed of several photodetectors is, for example, presented as a photodetector array in FIG. 9B .
  • the structure of the negative lens array of Fig. 12A and Fig. 12B can be selectively used according to the spacing of photodetectors.
  • the negative lens array is also readily packaged with the photodetector array for alignment with each photodetector. Since its precision reaches the millimeter level, it is not easy to affect the effect of elongating the focal length.
  • FIG. 13 shows a schematic structural diagram of the package of a photodetector array and a microlens array (ie, an array composed of a plurality of concave microlenses) in an embodiment of the present invention.
  • the figure shows a circuit substrate 1301 and an optical carrier 1302 .
  • the circuit substrate 130 such as a printed circuit board (PCB)
  • PCB printed circuit board
  • the figure exemplarily shows two columns or two rows of photodetectors 1303 in the photodetector array, but the number is not limited thereto.
  • the Z, X directions in FIG. 13 may be referred to in contrast to the X, Y, Z directions in FIGS. 8 , 11A, and 11B.
  • the optical carrier 1302 has a second surface on which the microlens array is disposed.
  • the optical carrier is packaged integrally with the circuit substrate and the second surface is opposite to the first surface, so that each of the microlenses 1305 (i.e. micro-concave lenses) is arranged corresponding to each of the photodetectors 1303, For example, the position correspondences in FIG. 11 , FIG. 12A , and FIG. 12B .
  • the circuit substrate may include a side wall 1306 protruding from the circuit substrate 1301 to surround the photodetector array, and the optical carrier 1302 is connected to the side wall 1306 to form an accommodating cavities for the photodetector array.
  • the circuit substrate 1301 and the side wall 1306 can be integrally formed, or can be independent parts.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Electromagnetism (AREA)
  • Optical Radar Systems And Details Thereof (AREA)

Abstract

L'invention concerne un radar laser (300), comprenant : une unité électroluminescente (301), qui est utilisée pour émettre un signal de détection lumineux ; une unité de réception de lumière (302), qui est utilisée pour recevoir un signal d'écho lumineux généré à partir du signal de détection lumineux ; un système optique principal (303), qui est disposé entre l'unité électroluminescente (301) et l'unité de réception de lumière (302), et qui est utilisé pour recevoir le signal de détection lumineux et le transmettre vers l'extérieur, et qui est utilisé pour recevoir le signal d'écho lumineux et transmettre le signal d'écho lumineux à l'unité de réception de lumière (302) ; et une unité de dilatation de faisceau (304), qui est disposée entre le système optique principal (303) et l'unité de réception de lumière (302), et qui est utilisée pour recevoir le signal de lumière d'écho traversant le système optique principal (303), effectuant une dilatation de faisceau sur le signal de lumière d'écho, et transmettant ensuite le signal lumineux d'écho à l'unité de réception de lumière (302), une longueur focale équivalente d'une combinaison du système optique principal (303) et de l'unité de dilatation de faisceau (304) étant supérieure à la longueur focale du système optique principal (303), de façon à comprimer le champ de vue de l'unité de réception de lumière (302). Le radar laser (300) permet, au moyen d'un système optique, d'étendre la distance focale d'une extrémité de réception, de manière à comprimer le champ de vue de l'extrémité de réception, ne nécessite aucun dispositif tel qu'un diaphragme, et interagit également avec un système optique effectuant une émission-réception coaxiale de manière à rendre la structure plus compacte.
PCT/CN2022/098405 2021-09-15 2022-06-13 Radar laser Ceased WO2023040377A1 (fr)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116660929A (zh) * 2023-05-26 2023-08-29 华域汽车系统股份有限公司 固态激光雷达
CN117554927A (zh) * 2024-01-11 2024-02-13 中国航天三江集团有限公司 随动式球形防护系统

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117826185B (zh) * 2023-12-30 2025-05-16 深圳阜时科技有限公司 光源芯片的开关电路、发射模组、检测装置及电子设备
CN119986603A (zh) * 2025-04-14 2025-05-13 深圳市威睿晶科电子有限公司 一种mini同轴机芯

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1967285A (zh) * 2006-09-14 2007-05-23 中国科学院安徽光学精密机械研究所 激光雷达透射式共焦距收发光学系统
CN102235625A (zh) * 2010-04-30 2011-11-09 精工爱普生株式会社 照明装置以及电子设备
US20160223671A1 (en) * 2011-06-30 2016-08-04 The Regents Of The University Of Colorado Remote measurement of shallow depths in semi-transparent media
WO2017204459A1 (fr) * 2016-05-26 2017-11-30 (주) 정상라이다 Appareil optique lidar ayant une structure améliorée
CN109870699A (zh) * 2019-04-03 2019-06-11 深圳市镭神智能系统有限公司 一种激光雷达
CN110806568A (zh) * 2018-08-01 2020-02-18 西克股份公司 用于检测对象的光电传感器和方法
CN211014630U (zh) * 2016-12-13 2020-07-14 森斯尔科技有限公司 激光雷达设备及机动车系统
CN113391295A (zh) * 2021-06-29 2021-09-14 昂纳信息技术（深圳）有限公司 一种激光雷达扫描系统和装置
CN215932142U (zh) * 2021-09-15 2022-03-01 上海禾赛科技有限公司 激光雷达

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1967285A (zh) * 2006-09-14 2007-05-23 中国科学院安徽光学精密机械研究所 激光雷达透射式共焦距收发光学系统
CN102235625A (zh) * 2010-04-30 2011-11-09 精工爱普生株式会社 照明装置以及电子设备
US20160223671A1 (en) * 2011-06-30 2016-08-04 The Regents Of The University Of Colorado Remote measurement of shallow depths in semi-transparent media
WO2017204459A1 (fr) * 2016-05-26 2017-11-30 (주) 정상라이다 Appareil optique lidar ayant une structure améliorée
CN211014630U (zh) * 2016-12-13 2020-07-14 森斯尔科技有限公司 激光雷达设备及机动车系统
CN110806568A (zh) * 2018-08-01 2020-02-18 西克股份公司 用于检测对象的光电传感器和方法
CN109870699A (zh) * 2019-04-03 2019-06-11 深圳市镭神智能系统有限公司 一种激光雷达
CN113391295A (zh) * 2021-06-29 2021-09-14 昂纳信息技术（深圳）有限公司 一种激光雷达扫描系统和装置
CN215932142U (zh) * 2021-09-15 2022-03-01 上海禾赛科技有限公司 激光雷达

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116660929A (zh) * 2023-05-26 2023-08-29 华域汽车系统股份有限公司 固态激光雷达
CN117554927A (zh) * 2024-01-11 2024-02-13 中国航天三江集团有限公司 随动式球形防护系统
CN117554927B (zh) * 2024-01-11 2024-04-09 中国航天三江集团有限公司 随动式球形防护系统

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