WO2023207009A1 - 激光雷达 - Google Patents

激光雷达 Download PDF

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Publication number
WO2023207009A1
WO2023207009A1 PCT/CN2022/128702 CN2022128702W WO2023207009A1 WO 2023207009 A1 WO2023207009 A1 WO 2023207009A1 CN 2022128702 W CN2022128702 W CN 2022128702W WO 2023207009 A1 WO2023207009 A1 WO 2023207009A1
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WIPO (PCT)
Prior art keywords
scanning
view
lidar
transceiver module
beams
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PCT/CN2022/128702
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English (en)
French (fr)
Inventor
张辰琛
吴世祥
向少卿
Original Assignee
上海禾赛科技有限公司
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Priority claimed from CN202220973614.8U external-priority patent/CN217543379U/zh
Priority claimed from CN202210434431.3A external-priority patent/CN116973886A/zh
Application filed by 上海禾赛科技有限公司 filed Critical 上海禾赛科技有限公司
Publication of WO2023207009A1 publication Critical patent/WO2023207009A1/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

  • the invention relates to the field of laser detection, and in particular to a laser radar.
  • Lidar is a radar system that emits laser beams to detect characteristics such as the position and speed of targets. Its working principle is to emit a detection signal (laser beam) to the target, and then compare the received signal (echo) reflected from the target with the transmitted signal. After appropriate processing, the relevant information of the target can be obtained, such as the target Parameters such as distance, orientation, altitude, speed, attitude, and even shape can be used to detect, track, and identify targets.
  • laser beam laser beam
  • echo received signal
  • the relevant information of the target can be obtained, such as the target Parameters such as distance, orientation, altitude, speed, attitude, and even shape can be used to detect, track, and identify targets.
  • Flash lidar is a non-scanning lidar. Its transmitting component and receiving component adopt an array arrangement structure. It has the problem of small field of view. The lidar detection field of view is only expanded through the optical system. Moreover, the luminous power of its emitting component is limited, and each pixel in the receiving component receives less energy on average, making it suitable for close-range detection.
  • the invention provides a laser radar to improve the point frequency and long-distance detection capabilities of the laser radar and increase the field of view range of the laser radar.
  • the present invention provides a laser radar, which includes: a transceiver module configured to emit multiple emission beams to form a local field of view; and a scanning device configured to utilize the multiple emission beams to perform Scan to form a plurality of partial fields of view, and the plurality of partial fields of view are configured to be spliced to form a sub-scanning field of view; and the plurality of sub-scanning fields of view are configured to be spliced to form a total scanning field of view of the lidar.
  • the transceiver module is configured to simultaneously emit the plurality of emission beams to form the partial field of view.
  • the scanning device is configured to scan using multiple emission beams of the transceiver module to form a sub-scanning field of view corresponding to the transceiver module.
  • the scanning device is configured to scan according to a scanning curve, so that multiple partial fields of view are spliced according to the scanning curve to form the sub-scanning field of view.
  • the plurality of transceiver modules include: a first transceiver module that detects the first area, and a second transceiver module that detects the second area.
  • the detection resolution corresponding to the first area is higher than that of the second area. Corresponding detection resolution.
  • the scanning device uses multiple emission beams of the first transceiver module to scan according to the first scanning curve, and uses multiple emission beams of the second transceiver module to scan according to the second scanning curve, so The scanning frequency of the first scanning curve is greater than the scanning frequency of the second scanning curve.
  • a plurality of the transceiver modules are arranged in sequence along the horizontal direction, the transceiver module located in the central area is the first transceiver module, and the transceiver module located in the end area is the second transceiver module.
  • the plurality of emitted beams form a scanning beam after passing through a scanning device; the scanning device is configured to cause the scanning beam to traverse the sub-scanning field of view through scanning.
  • the scanning device is further configured to cause scanning beams corresponding to multiple transceiver modules to traverse the total scanning field of view through scanning.
  • the scanning device is configured to use the plurality of emission beams to perform one or more of isochronous trigger scanning, iso-angular trigger scanning, and iso-phase trigger scanning.
  • the plurality of emission beams are projected to the target object through the scanning device to form an echo beam; the transceiver module is further configured to detect the echo beam.
  • the transceiver module includes: a transmitting device that emits multiple transmitting beams, and a receiving device that detects the echo beam; the multiple transmitting beams emitted by the transmitting device are configured to form linear light, and the receiving device It includes a plurality of detection units arranged in one dimension; alternatively, the multiple beams emitted by the transmitting device are configured to form planar light, and the receiving device includes a plurality of detection units arranged in a two-dimensional arrangement.
  • the scanning device is configured to perform two-dimensional scanning using the multiple emission beams, and the two-dimensional scanning includes: a slow-axis scanning direction and a fast-axis scanning direction.
  • the fast-axis scanning direction is a horizontal direction
  • the slow-axis scanning direction is a vertical direction
  • the multiple emission beams emitted by the emission device are configured to form linear light; the linear light extends along the slow axis scanning direction.
  • the scanning device uses the linear light to scan according to the scanning curve, so that the linear light traverses the sub-scanning field of view and/or the total scanning field of view.
  • the emitting device includes: a emitting unit and a uniform light element located on the light path of the emitting unit.
  • multiple transceiver modules are configured to emit light in a time-sharing manner.
  • the lidar uses multiple emitted beams for detection in a local field of view, ensuring that the lidar has high point frequency and long-distance detection capabilities; on the other hand, it scans through a scanning device to form multiple local fields of view, and multiple The partial fields of view are spliced into sub-scanning fields of view, and multiple sub-scanning fields of view can be further spliced to obtain a larger total scanning field of view, thereby expanding the field of view of the lidar.
  • Figure 1 is a schematic diagram of a laser radar according to the first embodiment of the present invention
  • FIG. 2 is a schematic structural diagram of the lidar shown in Figure 1;
  • Figure 3 is a schematic diagram of the partial field of view obtained by the lidar in Figure 2;
  • Figure 4 is an enlarged view of the partial field of view in Figure 3;
  • Figure 5 is a schematic diagram of the sub-scanning field of view and the total scanning field of view obtained by the lidar in Figure 3;
  • Figure 6 is a partial schematic diagram of the neutron scanning field of view in Figure 5;
  • FIGS 7 to 9 are schematic diagrams of the three scanning modes of the scanning device in Figure 1;
  • Figure 10 is a schematic diagram of the partial field of view of the laser radar according to the second embodiment of the present invention.
  • Figure 11 is a schematic diagram of the sub-scanning field of view of the laser radar according to the second embodiment of the present invention.
  • Figure 12 is a schematic diagram of the sub-scanning field of view of the lidar according to the third embodiment of the present invention.
  • the present invention provides a lidar, which includes: a transceiver module configured to emit multiple transmit beams to form a local Field of view; a scanning device configured to scan using the plurality of emitted beams to form a plurality of partial fields of view, and the plurality of partial fields of view are configured to be spliced to form a sub-scanning field of view; a plurality of the sub-scanning fields of view; The fields are configured to be stitched together to form the total scanning field of view of the lidar.
  • the lidar of the present invention uses multiple emitted beams for detection in a local field of view, ensuring that the lidar has high point frequency and long-distance detection capabilities; on the other hand, the scanning device uses emitted beams for scanning to form multiple local fields of view. field, a plurality of the partial fields of view are spliced into sub-scanning fields of view, and the plurality of sub-scanning fields of view can be further spliced to obtain a larger total scanning field of view, thereby expanding the field of view of the laser radar.
  • FIGS. 1 to 6 the functional block diagram, structural schematic diagram, local field of view diagram and its enlarged diagram and total scanning field of view diagram of the lidar according to an embodiment of the present invention are respectively shown.
  • Figure 2 takes a laser radar with three transceiver modules as an example. In other embodiments, the number of transceiver modules of the laser radar can also be two or three. More than one.
  • the lidar 10 includes: a transceiver module 100 and a scanning device 200 .
  • the lidar 10 includes a transceiver module 100, which can expand the scanning range of the lidar, thereby expanding the field of view of the lidar.
  • the transceiver module 100 is configured to emit multiple emission beams to form a local field of view 300.
  • the multiple emission beams are projected to the target object to form an echo beam.
  • the transceiver module 100 is also configured to detect the echo beam to achieve Lidar detects targets.
  • the transceiver module 100 includes: a transmitting device 101 configured to emit multiple transmit beams, and a receiving device 102 configured to detect the echo beams.
  • the lidar includes three transceiver modules 100 . More specifically, each transceiver module 100 includes a transmitting device 101 and a corresponding receiving device 102 .
  • the transceiver module 100 is configured to emit the plurality of transmitting beams.
  • Figure 3 which is a schematic optical path diagram of a transceiver module in Figure 2
  • the transmitting device 101 in the transceiver module 100 includes a plurality of transmitting units 1011, wherein each transmitting unit 1011 emits one of the plurality of transmitting beams.
  • Emitting light beams can improve the detection coverage of lidar, thereby helping to improve the detection performance of lidar.
  • multiple emission units 1011 are used to emit the multiple emission beams at the same time, that is, each emission unit 1011 emits the emission beam at the same time to form the multiple emission beams.
  • multiple emission units 1011 can also emit multiple emission beams in a time-sharing manner. For example, multiple emission units 1011 are turned on sequentially in a polling manner, thereby emitting emission beams in a time-sharing manner.
  • the emission unit 1011 in this embodiment is a vertical-cavity surface-emitting laser (VCSEL for short).
  • the emission unit 1011 may also be an edge emitting laser (Edge Emitting Laser, EEL for short).
  • the emitting device 101 is configured to emit one-dimensionally arranged point light.
  • the plurality of emitting units 1011 in the emitting device 101 can be arranged in a one-dimensional array.
  • the multiple transmitting units 1011 in the transmitting device 101 may also be arranged in a two-dimensional array.
  • multiple point lights are arranged in a one-dimensional array along the vertical direction.
  • the plurality of point lights may also be arranged in a one-dimensional array along other directions (for example, at an angle with the vertical direction).
  • the emitting device 101 further includes a uniform light element 1012 for uniformly distributing the multiple emitted beams of the emitting device 101 .
  • the uniform light element 1012 is configured to expand the field of view formed by the emitting device 101 to form a partial field of view 300 .
  • the uniform light element 1012 is a uniform light plate or a diffraction element (Diffractive Optical Element, DOE), which can uniformly emit multiple point-like lights from multiple emission units 1011 to form linear light (or strip-shaped light). ), forming a local field of view 300.
  • DOE diffractive Optical Element
  • the shape of the light beam obtained after homogenization can also be other shapes, such as circles, squares, ellipses, vertical stripes, rhombuses, and other polygons.
  • the shape of the beam can be changed by changing the shape of the laser's light emitting area and/or constraining the beam by a uniform light element.
  • the lidar 10 adopts a coaxial receiving and receiving optical system, and the transmitting device 101 and the receiving device 102 are located on the same side of the scanning device 200 , which can improve the compactness of the lidar 10 .
  • the lidar 10 also includes a plurality of optical elements for changing the propagation direction of the emitted beam (or echo beam), or changing the shape of the emitted beam (or echo beam).
  • the laser radar 10 also includes: a spectroscopic element 103 for reflecting the emitted beam and transmitting the echo beam.
  • the light splitting element 103 may be a polarizing beam splitter (PBS).
  • the light splitting element may also be a polarizing light splitter. In other embodiments, light splitting can also be achieved through multiple partially reflective mirrors.
  • the lens group 104 is used to collimate the emitted beam, and is also used to converge the echo beam so that the echo beam can be projected to the receiving device 102 for detection.
  • the lens group 104 may include a combination of convex lenses and concave lenses.
  • the wave plate 105 is used to change the polarization state of the emitted beam and the echoed beam to facilitate light splitting through the spectroscopic element 103.
  • the wave plate 105 is a quarter wave plate.
  • the reflector 106 is used to change the propagation direction of the emitted beam so that the emitted beam is projected to the scanning device 200; it is also used to change the propagation direction of the echo beam so that the echo beam is projected to the wave plate 105.
  • the concave lens 107 further narrows the echo beam and increases the focal length of the optical system, which is beneficial to improving the signal-to-noise ratio of the received signal.
  • the transmitting device 101 emits multiple emission beams at the same time.
  • the multiple emission beams are uniformized by the light uniforming element 1012 and then projected to the spectroscopic element 103.
  • the emission beams are reflected by the spectroscopic element 103 and then transmitted to the bottom reflector (Fig. (not marked in ), and then reflect the emitted beam to the lens group 104 through the bottom reflector for collimation, then pass through the wave plate 105 to obtain the emitted beam in the first polarization state, and the reflector 106 reflects the emitted beam in the first polarization state to the scanning device 200.
  • the scanning beam is obtained through the scanning device 200, and the scanning beam passes through the target object to obtain an echo beam.
  • the echo beam passes through the scanning device 200 and the reflector 106 in sequence and reaches the wave plate 105. After passing through the wave plate 105, the echo beam of the second polarization state is obtained; the lens group 104 converges the echo beam of the second polarization state and projects it to The spectroscopic element 103 can transmit the echo beam of the second polarization state, and the transmitted echo beam is reflected to the receiving device 102 for detection through the concave lens 107 and the top reflector (not labeled in the figure).
  • the receiving device 102 is configured to detect the echo beam.
  • the detection area of the receiving device 102 is set to be able to detect at least the echo beam corresponding to the furthest detection distance of the lidar, that is, the light spot formed by the echo beam can be located within the detection area. It should be noted that during the actual use of lidar, the transmitting beam emitted by the transmitting device 101 and the echo beam received by the receiving device 102 are prone to position deviation, resulting in a deviation in the position of each beam. Therefore, the receiving device 102 The detection area can also be appropriately increased to increase the margin during detection and prevent the receiving device from being unable to receive the echo beam due to beam position deviation.
  • the receiving device 102 includes multiple detection units 1021.
  • Each detection unit 1021 has a photosensitive surface.
  • the photosensitive surfaces of the multiple detection units 1021 constitute the detection area.
  • the shape and number of the detection units can be configured. , arrangement mode and gating mode, so that the detection area of the receiving device 102 meets the detection requirements.
  • multiple transmitting units 1011 emit multiple point-shaped lights to obtain linear light.
  • the detection units 1021 in the receiving device 102 are rectangular, and the multiple detection units 1021 are along the line.
  • the extending direction of the linear light is arranged in a one-dimensional array, thereby forming a detection area that matches the shape of the linear light.
  • the number of detection units 1021 arranged in the one-dimensional array is also set to: the entire photosensitive area can detect the scanning beam of the farthest detection distance of the lidar, and on this basis, more detection units 1021 can be arranged at both ends of the one-dimensional array Several detection units 1021 are provided to increase the margin when detecting the margin and prevent the receiving device from being unable to receive the echo beam due to beam position deviation.
  • the plurality of detection units 1021 may also be arranged in a two-dimensional array, and by strobing some of the detection units 1021, the gated detection area can match the linear light shape.
  • the corresponding detection unit can also be selected according to the distance of the detection target; for example, if the target distance is farther and the spot of the echo beam is smaller, a smaller number of detection units 1021 can be selected; when the target distance is closer, The echo beam has a larger spot, and a larger number of detection units 1021 can be gated.
  • the corresponding detection unit 1021 can be gated according to the angle of the scanning device 200 to obtain a detection area that matches the angle of the scanning device 200 .
  • the detection unit 1021 is a SIPM detector (Silicon photomultiplier). In other embodiments, the detection unit may also include an Avalanche Photo Diode (APD) or a single photon detector. Avalanche Diode (SPAD).
  • SIPM detector Silicon photomultiplier
  • Avalanche Photo Diode Avalanche Diode
  • SPAD Avalanche Diode
  • LiDAR 10 extends the radar's local field of view 300 by scanning the device 200 . In the local field of view, multiple beams are emitted simultaneously for detection, so that the lidar has high point frequency and long-distance detection capabilities.
  • the lidar 10 further includes: a scanning device 200 configured to scan using the plurality of emitted beams to form a plurality of local fields of view, and the plurality of local fields of view are configured as The sub-scanning fields of view are spliced to form a plurality of sub-scanning fields of view and configured to be spliced to form a total scanning field of view of the laser radar.
  • a scanning device 200 configured to scan using the plurality of emitted beams to form a plurality of local fields of view, and the plurality of local fields of view are configured as The sub-scanning fields of view are spliced to form a plurality of sub-scanning fields of view and configured to be spliced to form a total scanning field of view of the laser radar.
  • the multiple emission beams emitted by the transceiver module 100 are configured to form a local field of view 300, and then the multiple emission beams are projected to the scanning device 200, and a scanning beam is formed via the scanning device 200.
  • the scanning device 200 forms a plurality of partial fields of view 300 by changing the positions of multiple emission beams emitted by a transceiver module 100.
  • the splicing of the plurality of partial fields of view 300 forms a sub-scanning field of view 400.
  • the scanning device 200 can further change the positions of multiple emission beams emitted by other transceiver modules 100, thereby obtaining a larger total scanning field of view 500.
  • the splicing of fields of view here refers to the splicing of multiple partial fields of view 300 formed when the scanning device 200 is at different scanning positions at different times, and the splicing of multiple partial fields of view 300 of the same transceiver module 100 to form a sub-scan.
  • Field of view 400, sub-scanning fields of view 400 corresponding to multiple transceiver modules 100 are spliced into a total scanning field of view 500.
  • three sub-scanning fields of view 400 are spliced into a total scanning field of view 500 .
  • the multiple transceiver modules 100 are configured to emit light in a time-sharing manner, that is, multiple transmitting units 1011 in the same transceiver module 100 emit light in a time-sharing manner, and the transmitting units 1011 of different transceiver modules 100 emit light in a time-sharing manner.
  • the scanning device 200 scanning multiple transceiver modules in 100-minute intervals can reduce the interference of light beams between transceiver modules, thereby reducing crosstalk problems.
  • the scanning device 200 is configured to scan within a certain angle range to obtain a scanning beam.
  • the scanning device 200 can periodically oscillate or rotate back and forth within a range of 15 degrees, and accordingly, the resulting scanning beam can scan within a range of 30 degrees.
  • three transceiver modules 100 are scanned by one scanning device 200. Specifically, the emission beams emitted by the three transceiver modules 100 are all reflected by the center position of the scanning device 200, but the three The emitted beams from the transceiver module 100 are incident on the center of the scanning device from different angles and are reflected by the scanning device.
  • the scanning device 200 uses the emitted beams emitted by the three transceiver modules 100 to scan through periodic oscillation or rotation. In the working state, the scanning The device 200 can use the emitted beams of the three transceiver modules 100 for scanning according to actual application scenarios.
  • the middle transceiver module 100 emits multiple emission beams, and the scanning device 200 periodically oscillates or rotates to scan using the emission beams of the middle transceiver module 100 to obtain the corresponding sub-scanning field of view 400; then the transceiver module 100 at one end Multiple emission beams are emitted, and the scanning device 200 uses the emission beams of the end transceiver module 100 to scan again through periodic oscillation or rotation to obtain the corresponding sub-scanning field of view 400; similarly, the other end transceiver module 100 can also be obtained The sub-scanning field of view 400 is obtained, and the total scanning field of view 500 is obtained. In other embodiments, the scanning device 200 can also only use the emitted beams of one or two transceiver modules 100 for scanning.
  • the plurality of emitted beams form a scanning beam after passing through the scanning device 200 , and the scanning device 200 is configured to cause the scanning beam to traverse the sub-scanning field of view 400 through scanning.
  • the meaning of traversal here means that the scanning beam can cover the entire sub-scanning field of view 400 through scanning, thereby improving the detection coverage.
  • the scanning device 200 is also configured to cause the scanning beams corresponding to the plurality of transceiver modules 100 to traverse the total scanning field of view 50 through scanning.
  • the meaning of traversal here means that the scanning beam can make multiple sub-scanning fields of view 400 cover the entire total scanning field of view 500 after scanning, thereby improving the detection coverage.
  • three transceiver modules 100 correspond to three sub-scanning fields of view 400 , and adjacent sub-scanning fields of view 400 are in contact (or partially overlapped), so that the scanning beam can traverse the total scanning field of view 500 .
  • the scanning device 200 in the embodiment of the present invention includes one or more scanning mirrors among a galvanometer, a swing mirror, and a rotating mirror.
  • the scanning device 20 may include one or more scanning mirrors. Specifically, the scanning mirror is configured to rotate, oscillate, tilt, pivot or move at a specific angle around one or more axes, obtained by reflecting multiple emitted beams. Scanning beam.
  • the scanning device 20 can realize two-dimensional scanning. Specifically, the scanning device 20 can use a single scanning mirror and be driven to rotate around two scanning axes. In the scanning device 20 shown in Figure 2, the scanning mirror is circular. In other embodiments, the scanning mirror can also be in an elliptical, square or other geometric shape.
  • the scanning device 20 also includes a scanning actuator connected with the scanning mirror.
  • the scanning actuator changes the direction of the scanning beam by changing the angle of the scanning mirror, thereby achieving scanning.
  • the scanning actuator can drive the scanning mirror for fast scanning along one axis and slow scanning along the other axis, where the fast axis and the slow axis can be perpendicular to each other.
  • the scan actuator may be configured to drive a single scan mirror with a resonant response at one or more frequencies of the drive signal to produce a desired periodic motion.
  • the scanning actuator may be by any suitable actuation mechanism.
  • the scanning actuator controls the vibrating scanning mirror electromagnetically.
  • the scanning device 20 further includes a control unit for outputting a driving signal to drive the scanning actuator to drive the scanning mirror to control the scanning beam in a desired direction or configured scanning curve.
  • the scanning device 200 is configured to scan according to the scanning curve 201 so that the partial field of view 300 is scanned according to the scanning curve 201 to splice into the sub-scanning field of view 400.
  • the scanning device 200 controls the scanning path of the scanning beam through the sinusoidal scanning curve 201, so that the scanning beam can traverse the sub-scanning field of view 400. Specifically, during scanning, the scanning device 200 causes the scanning beam to reciprocate in the fast axis direction, and gradually moves along the slow axis direction during the reciprocating motion to obtain a sine wave scanning curve 201 as shown in FIG. 3 .
  • the scan curve may also be one or more of a triangle wave scan curve, a sawtooth wave scan curve, a Z-shaped scan curve, and a raster scan curve.
  • the multiple emission beams emitted by the transceiver module 100 are uniformly lightened to obtain linear light.
  • the scanning device uses the linear light to scan according to the scanning curve, so that the linear light is Light traverses the sub-scan field of view and/or the total scan field of view.
  • the scanning device 200 is configured to use the multiple emission beams to perform two-dimensional scanning.
  • the two-dimensional scanning includes: slow axis scanning direction (Y direction in Figure 3) and Fast axis scanning direction (X direction in Figure 3). With two-dimensional scanning, the field of view can be expanded in both directions.
  • the fast-axis scanning direction of the scanning device 200 is the horizontal direction
  • the slow-axis scanning direction is the vertical direction.
  • the fast axis scanning direction and the slow axis scanning direction can also be changed according to specific application scenarios.
  • FIG. 6 is a partial schematic diagram of the sub-scanning field of view shown in FIG. 5 .
  • the multiple emission beams emitted by the emission device 101 are configured to form linear light L, and the linear light L extends along the slow axis scanning direction (that is, the vertical direction), so that when the scanning device 200 When scanning back and forth in the axial scanning direction, the linear light L can cover a larger area, thereby obtaining a larger sub-scanning field of view 400.
  • the local fields of view 300 in the row direction or column direction are all connected or partially overlapped, which can increase the number of scanning points in this area, thereby improving the detection of the central area. Coverage.
  • the scanning device 200 is configured to perform isochronous trigger scanning using the multiple emission beams.
  • the scanning device 200 shown in Figure 2 can change the reflection angle of the emitted beam by changing the angle.
  • the scanning speed During scanning, it reciprocates along the fast axis scanning direction. The faster the scanning speed is near the middle area, the faster it is near the two ends. The scanning speed of the central area is slower.
  • the scanning intervals are the same.
  • the spacing between scanning points in the middle area is large, and the spacing between scanning points located at the two end areas is small (refer to Figure 7).
  • the scanning device can also use equal-angle trigger scanning (as shown in FIG. 8 ) to obtain a more uniform scanning point arrangement.
  • equal-phase trigger scanning (as shown in Figure 9) can also be used to obtain another scanning point arrangement.
  • the scanning field of view at the location of each scanning point is a partial field of view 300 as shown in Figure 3.
  • a larger sub-scanning field of view 400 can be obtained.
  • the larger local field of view 300 combined with the scanning device can enable the lidar to have high point frequency and long-distance detection capabilities.
  • the resolution in the middle area is relatively low. High, and in the scanning point arrangement shown in Figure 8, the resolution in the edge area is higher.
  • the sub-scanning fields of view 400 corresponding to the multiple transceiver modules 100 are spliced into a total scanning field of view 500.
  • the scanning device 200 can adopt the same scanning method for the emission beams emitted by the multiple transceiver modules 100 .
  • the scanning device 200 may also adopt different scanning methods for the emission beams emitted by the multiple transceiver modules 100 .
  • the three transceiver modules are arranged in sequence along the horizontal direction, including: the first transceiver module 111 located in the middle, configured to detect the central area; and the second transceiver module 111 located at both ends.
  • the transceiver module 112 is configured to detect the end area.
  • LiDAR should be configured in a general scenario of a vehicle.
  • the central area is the area of greater concern during driving. Therefore, the scanning device 200 can be set so that the detection resolution corresponding to the central area is higher than the detection resolution corresponding to the end areas. On the one hand, higher detection resolution can be obtained in the central area where more attention is paid during driving. On the other hand, the relatively low detection rate in the end areas can increase detection efficiency.
  • the scanning device 200 in the end area can also be set to have a higher detection resolution. For example, when parking sideways during driving, more attention will be paid to the end area compared to the central area. Detection information of the area. At this time, the scanning mode of the scanning device 200 can be switched so that the scanning device uses a scanning mode with high detection resolution when scanning the end area.
  • the three transceiver modules 100 use the same scanning device 200 to scan.
  • the scanning device 200 uses multiple emission beams of the first transceiver module 111 according to the first scanning curve. Scanning is performed, and the plurality of emission beams of the second transceiver module 112 are used to scan according to a second scanning curve, where the scanning frequency of the first scanning curve is greater than the scanning frequency of the second scanning curve.
  • the scanning device 200 uses an isochronous triggering method to scan, a first time interval is used when scanning using the emitted beam of the first transceiver module 111, and a second time interval is used when scanning using the emitted beam of the second transceiver module 112.
  • the second time interval is twice the first time interval, so that the scanning point density obtained by the first transceiver module 111 is much greater than that of the second transceiver module 112, so that the central area obtains a higher detection resolution.
  • other methods may be used to make the detection resolutions of the two areas different.
  • FIG. 10 and FIG. 11 a schematic diagram of a partial field of view and a schematic diagram of a sub-scanning field of view of the lidar according to the second embodiment of the present invention are shown.
  • the multiple emission beams emitted by the emission device are configured to form a planar light beam.
  • the receiving device includes a plurality of detection units arranged two-dimensionally.
  • the planar light P has a larger size in both directions, the local field of view can be increased. In addition, the coverage area of the planar light P is larger. For the same sub-scanning field of view, the scanning frequency of the scanning device can be reduced, thereby improving the scanning efficiency.
  • the shape of the emitted beam can be changed by using a laser or a diffuser in the emitting device to obtain planar light P.
  • the transmitting device can be a VCSEL array arranged in two dimensions
  • the receiving device can be a single photon detector array arranged in two dimensions.
  • other methods may be used to obtain the planar light P.
  • FIG. 12 shows a schematic diagram of a partial field of view of the laser radar according to the third embodiment of the present invention.
  • the scanning device uses a one-dimensional scanning method to scan.
  • the scanning beam is a linear light L and extends along the vertical direction. Through one-dimensional scanning in the horizontal direction, the linear light L can be scanned to obtain a rectangular sub-scanning view.
  • Field 403. Furthermore, by splicing multiple sub-scanning fields of view 403 to form a total scanning field of view, the purpose of increasing the total scanning field of view can be achieved.
  • the scanning device may be a rotating mirror or a swing mirror, and the one-dimensional scanning method of this embodiment is implemented by scanning in the horizontal direction.

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  • Computer Networks & Wireless Communication (AREA)
  • Physics & Mathematics (AREA)
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  • Optical Radar Systems And Details Thereof (AREA)

Abstract

提供一种激光雷达（10），包括：收发模块（100），收发模块（100）配置为发出多束发射光束，形成局部视场（300）；扫描器件（200），配置为利用多束发射光束进行扫描，形成多个局部视场（300），多个局部视场（300）配置为拼接形成子扫描视场（400）；多个子扫描视场（400）配置为拼接形成激光雷达（10）的总扫描视场（500）。由此扩大了激光雷达（10）的视场范围。

Description

激光雷达 技术领域
本发明涉及激光探测领域，尤其涉及一种激光雷达。
背景技术
随着无人驾驶技术的兴起，激光雷达作为重要的探测部件越来越受到重视。激光雷达顾名思义，是以发射激光束探测目标的位置、速度等特征量的雷达系统。其工作原理是向目标发射探测信号(激光束)，然后将接收到的从目标反射回来的信号(回波)与发射信号进行比较，作适当处理后，就可获得目标的有关信息，如目标距离、方位、高度、速度、姿态、甚至形状等参数，从而对目标进行探测、跟踪和识别。
Flash激光雷达(闪光激光雷达)为一种非扫描式的激光雷达，其发射部件和接收部件采用阵列排布结构，其存在视场较小的问题，仅通过光学系统扩展激光雷达探测视场，并且其发射部件的发光功率有限，接收部件中各个像素平均接收的能量较少，适合近距离探测。
发明内容
本发明提供一种激光雷达，以提高激光雷达的点频和远距离探测能力，并增大激光雷达的视场范围。
为了解决所述技术问题，本发明提供一种激光雷达，包括：收发模块，所述收发模块配置为发出多束发射光束，形成局部视场；扫描器件，配置为利用所述多束发射光束进行扫描，形成多个所述局部视场，多个所述局部视场配置为拼接形成子扫描视场；多个所述子扫描视场配置为拼接形成激光雷达的总扫描视场。
可选地，所述收发模块配置为同时发出所述多束发射光束，形成所述局部视场。
可选地，所述扫描器件配置为利用所述收发模块的多束发射光束进行扫 描，形成与所述收发模块对应的子扫描视场。
可选地，所述扫描器件配置为根据扫描曲线进行扫描，使多个所述局部视场按照所述扫描曲线拼接形成所述子扫描视场。
可选地，多个所述收发模块包括：探测第一区域的第一收发模块，和探测第二区域的第二收发模块，所述第一区域对应的探测分辨率高于所述第二区域对应的探测分辨率。
可选地，所述扫描器件根据第一扫描曲线利用所述第一收发模块的多束发射光束进行扫描，并根据第二扫描曲线利用所述第二收发模块的多束发射光束进行扫描，所述第一扫描曲线的扫描频率大于所述第二扫描曲线的扫描频率。
可选地，多个所述收发模块沿水平方向依次排布，位于中央区域的收发模块为所述第一收发模块，位于端部区域的收发模块为所述第二收发模块。
可选地，所述多束发射光束经由扫描器件后形成扫描光束；所述扫描器件配置为通过扫描使所述扫描光束遍历所述子扫描视场。
可选地，所述扫描器件还配置为使多个所述收发模块分别对应的扫描光束通过扫描遍历所述总扫描视场。
可选地，所述扫描器件，配置为利用所述多束发射光束进行等时触发扫描、等角度触发扫描以及等相位触发扫描中的一种或多种。
可选地，所述多束发射光束经由扫描器件后投射至目标物，形成回波光束；所述收发模块还配置为探测所述回波光束。
可选地，所述收发模块包括：发出多束发射光束的发射装置，和探测所述回波光束接收装置；所述发射装置发出的多束发射光束配置为形成线状光，所述接收装置包括一维排列的多个探测单元；或者，所述发射装置发出的多束光束配置为形成面状光，所述接收装置包括二维排列的多个探测单元。
可选地，所述扫描器件配置为利用所述多束发射光束进行二维扫描，所述二维扫描包括：慢轴扫描方向和快轴扫描方向。
可选地，所述快轴扫描方向为水平方向，所述慢轴扫描方向为竖直方向。
可选地，所述发射装置发出的多束发射光束配置为形成线状光；所述线状 光沿慢轴扫描方向延伸。
可选地，所述扫描器件根据扫描曲线利用所述线状光进行扫描，使所述线状光遍历所述子扫描视场和/或所述总扫描视场。
可选地，所述发射装置包括：发射单元以及位于发射单元发光光路上的匀光元件。
可选地，多个所述收发模块配置为分时发光。
与现有技术相比，本发明的技术方案具有以下优点：
激光雷达一方面在局部视场中采用多束发射光束进行探测，保证激光雷达具有高点频和远距离探测能力；另一方面通过扫描器件进行扫描，形成多个所述局部视场，多个所述局部视场拼接为子扫描视场，多个子扫描视场通过进一步拼接可以得到较大的总扫描视场，从而扩大了激光雷达的视场范围。
附图说明
图1是本发明第一实施例激光雷达的示意图；
图2是图1所示激光雷达的结构示意图；
图3是图2中激光雷达获得的局部视场的示意图；
图4是图3中局部视场的放大图；
图5是图3中激光雷达获得的子扫描视场和总扫描视场的示意图；
图6是图5中子扫描视场的局部示意图；
图7至图9是图1中扫描器件三种扫描方式的示意图；
图10是本发明第二实施例激光雷达的局部视场的示意图；
图11是本发明第二实施例激光雷达的子扫描视场的示意图；
图12是本发明第三实施例激光雷达的子扫描视场的示意图。
具体实施方式
针对背景技术提到的激光雷达具有较小视场以及远距离探测能力受限等问题，本发明提供一种激光雷达，包括：收发模块，所述收发模块配置为发出多束发射光束，形成局部视场；扫描器件，配置为利用所述多束发射光束进行扫描，形成多个所述局部视场，多个所述局部视场配置为拼接形成子扫描视场； 多个所述子扫描视场配置为拼接形成激光雷达的总扫描视场。
本发明激光雷达一方面在局部视场中采用多束发射光束进行探测，保证激光雷达具有高点频和远距离探测能力；另一方面扫描器件利用发射光束进行扫描，形成多个所述局部视场，多个所述局部视场拼接为子扫描视场，多个子扫描视场通过进一步拼接可以得到较大的总扫描视场，从而扩大了激光雷达的视场范围。
结合参考图1至图6，分别示出了本发明一实施例激光雷达的功能框图、结构示意图、局部视场图及其放大图和总扫描视场图。需要说明的是，为了使附图简洁、清楚，附图2以具有三个收发模块的激光雷达为例进行示意，在其他实施例中，激光雷达的收发模块的数量还可以是两个或者三个以上。
结合参考图1和图2，所述激光雷达10包括：收发模块100和扫描器件200。
激光雷达10包括收发模块100，能够扩大激光雷达的扫描范围，从而扩大激光雷达的视场范围。所述收发模块100配置为发出多束发射光束，形成局部视场300，所述多束发射光束投射至目标物形成回波光束，所述收发模块100还配置为探测所述回波光束，实现激光雷达探测目标物。
所述收发模块100包括：配置为发出多束发射光束的发射装置101，以及配置为探测所述回波光束的接收装置102。
如图2所示，激光雷达包括三个收发模块100，更具体的，每个收发模块100包括发射装置101以及相对应的接收装置102。
需要说明的是，本发明实施例中，所述收发模块100配置为发出所述多束发射光束。如图3所示的图2中一收发模块的光路示意图，所述收发模块100中的发射装置101包括多个发射单元1011，其中各个发射单元1011发出所述多束发射光束其中一束所述发射光束，能提高激光雷达的探测覆盖率，从而有助于提高激光雷达的探测性能。
本实施例中，多个发射单元1011用于同时发出所述多束发射光束，即各个发射单元1011同时发出所述发射光束，形成所述多束发射光束。在其他实施例中，多个发射单元1011还可以分时发出多束发射光束，例如：多个发射 单元1011采用轮巡方式依次开启，从而分时发出发射光束。
具体地，本实施例中所述发射单元1011为垂直腔面发射激光器(Vertical-Cavity Surface-Emitting Laser，简称VCSEL)。或者，发射单元1011还可以是边缘发射激光器(Edge Emitting Laser，简称EEL)。
参考图3，本实施例中，发射装置101配置为发出一维排列的点状光，具体地，发射装置101中的多个发射单元1011可以呈一维阵列排布。在其他实施例中，发射装置101中的多个发射单元1011还可以呈二维阵列排布。
如图3所示，本实施例中，多个点状光沿竖直方向呈一维阵列排布。在其他实施例中，多个点状光还可以是沿其他方向(例如与竖直方向呈一夹角)的一维阵列排布方式。
继续参考图3，所述发射装置101还包括匀光元件1012，用于使发射装置101的多束发射光束均匀分布。
所述匀光元件1012配置为扩大发射装置101形成的视场，以形成局部视场300。具体地，所述匀光元件1012是匀光片或者衍射元件(Diffractive Optical Element,DOE)，可以将多个发射单元1011发出多个点状光匀光后形成线状光(或长条状光)，构成局部视场300。
如图4所示，一维排列的多个点状光经过匀光元件1012匀光后，基于衍射原理形成三列点状光(图4以3列*5行的阵列作为示意)，这三列点状光整体呈现为图3所示的线状光。
需要说明的是，在其他实施例中，匀光后得到光束的形状还可以是其他的形状，比如圆形、方形、椭圆形、竖条纹形、菱形以及其他多边形等。实际应用中，可以通过改变激光器发光区域的形状，和/或匀光元件约束光束的方式改变光束的形状。
继续参考图2，本实施例中激光雷达10采用同轴收发光学系统，发射装置101和接收装置102位于扫描器件200同一侧，可以提高激光雷达10的紧凑性。
所述激光雷达10还包括多个光学元件，用于改变发射光束(或回波光束)的传播方向，或者改变发射光束(或回波光束)的形状。具体的，激光雷 达10还包括：分光元件103，用于反射所述发射光束，还用于透射所述回波光束。具体地，所述分光元件103可以为偏振分光棱镜(polarizing Beam Splitter，PBS)。所述分光元件还可以为偏振分光片。在其他实施例中，还可以通过多片部分反射的反射镜实现分光。透镜组104，用于准直所述发射光束，还用于会聚回波光束，使回波光束能投射至接收装置102进行探测。所述透镜组104可以包括凸透镜和凹透镜的组合。
波片105，用于改变发射光束和回波光束的偏振态，便于通过分光元件103实现分光。本实施例中，波片105为四分之一波片。
反射镜106，用于改变发射光束的传播方向，使发射光束投射至扫描器件200；还用于改变回波光束的传播方向，使回波光束投射至波片105。
凹透镜107，对回波光束进一步收窄，并增大光学系统焦距，有利于提高接收信号的信噪比。
激光雷达工作时，发射装置101同时发出多束发射光束，所述多束发射光束经过匀光元件1012匀光后投射至分光元件103，发射光束经过分光元件103反射后传输至底部反射镜(图中未标注)，再经由底部反射镜将发射光束反射至透镜组104准直后，经过波片105得到第一偏振态的发射光束，反射镜106将第一偏振态的发射光束反射至扫描器件200，经扫描器件200得到扫描光束，扫描光束经过目标物得到回波光束。回波光束依次经过扫描器件200和反射镜106到达波片105，通过波片105后得到第二偏振态的回波光束；透镜组104会聚第二偏振态的回波光束，并使其投射至所述分光元件103，分光元件103可以透射第二偏振态的回波光束，透射后的回波光束经由凹透镜107和顶部反射镜(图中未标注)反射至接收装置102进行探测。
所述接收装置102，配置为探测回波光束。
具体地，所述接收装置102的探测区域设置为：至少能探测到激光雷达最远探测距离对应的回波光束，即，该回波光束形成的光斑能位于探测区域内。需要说明的是，激光雷达在实际使用过程中，发射装置101发出的发射光束和接收装置102接收的回波光束容易产生位置偏移，从而造成各光束位置的偏移，因此，接收装置102的探测区域还可以适当增大，以增加探测时的裕量，避免接收装置由于光束位置偏移无法接收到回波光束。
具体地，所述接收装置102包括多个探测单元1021，每个探测单元1021,均有一个感光面，多个探测单元1021的感光面构成所述探测区域，可以通过配置探测单元的形状、数量、排布方式以及选通方式中的一种或多种，使接收装置102的探测区域满足探测要求。
如图3所示，本实施例中，多个发射单元1011发出多个点状光匀光后得到的是线状光，接收装置102中的探测单元1021为长方形，且多个探测单元1021沿线状光延伸方向呈一维阵列排布，从而形成与线状光形状相匹配的探测区域。
此外，一维阵列排布的探测单元1021的数量也设置为：整体感光面积可以探测到激光雷达最远探测距离的扫描光束，并在此基础上，在一维阵列的两端可以多排布几个探测单元1021，以增加探测裕量时的裕量，避免接收装置由于光束位置偏移无法接收到回波光束。
在其他实施例中，所述多个探测单元1021还可以为二维阵列的排布方式，通过选通其中的部分探测单元1021，使选通后的探测区域与线状光形状相匹配。或者，还可以根据探测目标距离的远近，选通相应的探测单元；例如：目标距离较远，回波光束的光斑较小，可以选通较少数量的探测单元1021；目标距离较近时，回波光束的光斑较大，可以选通较多数量的探测单元1021。或者，还可以根据扫描器件200的角度，选通相对应的探测单元1021，获得匹配该扫描器件200角度的探测区域。
本实施例中，所述探测单元1021为SIPM探测器(硅光电倍增管，Silicon photomultiplier)，在其他实施例中，所述探测单元还可以包括雪崩光电二极管(Avalanche Photo Diode，APD)或单光子雪崩二极管(SPAD)。
所述激光雷达10在工作时，收发模块100中的所述发射装置101和接收装置102同时处于打开状态。激光雷达10通过扫描器件200扩展了雷达的局部视场300。在局部视场中采用同时发射的多束发射光束匀光的方式进行探测，使激光雷达具有高点频和远距离探测能力。
继续参考图2至图5，所述激光雷达10还包括：扫描器件200，配置为利用所述多束发射光束进行扫描，形成多个所述局部视场，多个所述局部视场配置为拼接形成子扫描视场，多个所述子扫描视场配置为拼接形成激光雷达的总 扫描视场。
本发明实施例的激光雷达10中，收发模块100发出的多束发射光束配置为构成局部视场300，之后多束发射光束投射至扫描器件200，经由扫描器件200形成扫描光束。扫描器件200通过改变一收发模块100发出的多束发射光束的位置，形成多个所述局部视场300，多个局部视场300的拼接形成子扫描视场400。所述扫描器件200还可以进一步改变其他收发模块100发出的多束发射光束的位置，进而获得较大的总扫描视场500。
需要说明的是，此处的视场拼接指的是不同时刻扫描器件200处于不同扫描位置时形成的多个局部视场300相拼接，同一收发模块100的多个局部视场300拼接形成子扫描视场400，多个收发模块100对应的子扫描视场400拼接为总扫描视场500。如图5所示的，本实施例中三个子扫描视场400拼接为总扫描视场500。可选的，所述多个收发模块100配置为分时发光，即同一收发模块100中的多个发射单元1011同时发光，不同收发模块100的发射单元1011分时发光，相应的，扫描器件200，对多个收发模块100分时进行扫描，可以减少收发模块之间光束的干扰，从而减小串扰问题。
具体地，扫描器件200用于配置为在一定角度范围内扫描，得到扫描光束。例如，扫描器件200可以在15度范围内周期性地来回振荡或旋转，相应地，得到的扫描光束可以在30度范围内扫描。
如图2所示，本发明实施例中，三个收发模块100由一个扫描器件200进行扫描，具体地，三个收发模块100发出的发射光束均由扫描器件200的中心位置反射，但三个收发模块100的发射光束从不同的角度入射到扫描器件的中心位置并被扫描器件反射，扫描器件200通过周期性振荡或旋转利用三个收发模块100发出的发射光束进行扫描，工作状态时，扫描器件200可以根据实际应用场景，利用三个收发模块100的发射光束进行扫描。具体地，中间的收发模块100发出多束发射光束，扫描器件200周期性振荡或旋转利用中间的收发模块100的发射光束进行扫描，得到对应的子扫描视场400；之后一端部的收发模块100发出多束发射光束，扫描器件200再次通过周期性振荡或旋转利用该端部收发模块100的发射光束进行扫描，获得对应的子扫描视场400；类似地，还可以得到另一端部收发模块100的子扫描视场400，进而得到总扫描视场500。其他实施例中，扫描器件200还可以仅利用其中的一个或两个收发模 块100的发射光束进行扫描。
需要说明的是，所述多束发射光束经由扫描器件200后形成扫描光束，所述扫描器件200配置为通过扫描使所述扫描光束遍历所述子扫描视场400。此处遍历的含义指的是：扫描光束通过扫描能够覆盖整个子扫描视场400，从而可以提高探测覆盖率。
还需要说明的是，所述扫描器件200还配置为使所述多个收发模块100分别对应的扫描光束通过扫描遍历所述总扫描视场50。此处遍历的含义指的是：扫描光束通过扫描能够使多个子扫描视场400拼接后覆盖整个总扫描视场500，从而可以提高探测覆盖率。
如图2和5所示，三个收发模块100对应三个子扫描视场400，相邻的子扫描视场400相接触(或者部分重叠)，可以实现扫描光束遍历所述总扫描视场500。
具体地，本发明实施例中所述扫描器件200包括振镜、摆镜以及转镜中的一种或多种扫描镜。
扫描器件20可以包括一个或多个扫描镜，具体地，扫描镜配置为围绕一个或多个轴以特定角度的方式旋转、振荡、倾斜、枢转或移动，通过对多束发射光束进行反射获得扫描光束。扫描器件20可以实现二维扫描，具体地，扫描器件20可以使用单个扫描镜，被驱动围绕两个扫描轴旋转。如2所示的扫描器件20中扫描镜为圆形，在其他实施例中，所述扫描镜还可以为椭圆形、方形等几何形状。
扫描器件20还包括扫描致动器，与扫描镜连接。扫描致动器通过改变扫描镜的角度改变扫描光束的方向，从而实现扫描。对于二维扫描，扫描致动器可以驱动扫描镜沿一个轴的快速扫描和沿另一轴的慢速扫描，其中，快轴和慢轴可以相互垂直。扫描致动器可以被设置为：驱动单个扫描镜在驱动信号的一个或多个频率处具有谐振响应以产生期望的周期运动。
具体地，所述扫描致动器可以通过任何合适的致动机构。本实施例中，扫描致动器通过电磁控制振动的扫描镜。
扫描器件20还包括控制单元，用于输出驱动信号，以驱动扫描致动器带动所述扫描镜以在期望的方向或配置的扫描曲线控制扫描光束。
本发明实施例中，扫描器件200配置为根据扫描曲线201进行扫描，使所述局部视场300按照所述扫描曲线201的方式扫描，以拼接成所述子扫描视场400。
本发明实施例中，扫描器件200通过正弦波的扫描曲线201控制扫描光束的扫描路径，从而使扫描光束可以遍历子扫描视场400。具体地，扫描时扫描器件200使扫描光束在快轴方向上往复运动，且在往复运动过程中沿慢轴方向逐渐移动，获得如图3所示的正弦波扫描曲线201。
需要说明的是，在其他实施例中，扫描曲线还可以是三角波扫描曲线、锯齿波扫描曲线、Z型扫描曲线以及光栅型扫描曲线中的一种或多种。
如图3所示，本实施例中，收发模块100发出的多束发射光束经过匀光后得到线状光，所述扫描器件根据扫描曲线利用所述线状光进行扫描，使所述线状光遍历所述子扫描视场和/或所述总扫描视场。
如图3所示，本发明实施例中，所述扫描器件200配置为利用所述多束发射光束进行二维扫描，所述二维扫描包括：慢轴扫描方向(图3的Y方向)和快轴扫描方向(图3的X方向)。通过二维扫描，可以在两个方向上实现视场范围的扩大。
需要说明的是，本发明实施例中，扫描器件200的快轴扫描方向为水平方向，所述慢轴扫描方向为竖直方向。在其他实施例中，还可以根据具体的应用场景，改变快轴扫描方向和慢轴扫描方向。
参考图6，为图5所示子扫描视场的局部示意图。本实施例中，所述发射装置101发出的多束发射光束配置为形成线状光L，所述线状光L沿慢轴扫描方向(即竖直方向)延伸，这样在扫描器件200在快轴扫描方向往复扫描时，可以使线状光L覆盖较大的区域，从而获得较大的子扫描视场400。
此外，如图6所示的中心区域(虚线框所示)，行方向或列方向的局部视场300均相接或者部分重叠，可以提高该区域的扫描点数量，从而提高了中心区域的探测覆盖率。
本发明实施例中，扫描器件200配置为利用所述多束发射光束进行等时触发扫描。以图2所示的扫描器件200为例，扫描器件200通过改变角度可以改变发射光束的反射角度，扫描时沿着快轴扫描方向往复运动，位于靠近中间区 域扫描速度越快，靠近两个端部区域扫描速度较慢，采用等时触发的方式扫描时，扫描间隔相同，相应地，位于中间区域的扫描点间隔大，位于两个端部区域的扫描点间隔小(参考图7)。
需要说明的是，在其他实施例中，扫描器件还可以采用等角度触发扫描(如图8所示)，获得较为均匀的扫描点排布。或者，还可以采用等相位触发扫描(如图9所示)，获得另一种扫描点排布。
本发明实施例中，每一个扫描点所在位置的扫描视场为如图3所示的局部视场300，通过扫描器件200扫描，可以得到较大的子扫描视场400。
此外，本发明实施例，较大的局部视场300结合扫描器件，可以使激光雷达具有高点频和远距离探测能力，如图7所示的扫描点排布，中间区域的分辨率相对较高，而图8所示的扫描点排布中，位于边缘区域的分辨率较高。
多个收发模块100对应的子扫描视场400拼接为总扫描视场500。扫描器件200可以对多个收发模块100发出的发射光束采用相同的扫描方式。或者，为了匹配不同的应用场景，扫描器件200还可以对多个收发模块100发出的发射光束采用不同的扫描方式。
请继续参考图2和图5，本发明实施例中所述三个收发模块沿水平方向依次排布，包括：位于中间的第一收发模块111，配置为探测中央区域；以及位于两端的第二收发模块112，配置为探测端部区域。
激光雷达应配置为车辆的一般场景下，中央区域为驾驶过程中更为关注的区域，因此，扫描器件200可以设置为中央区域对应的探测分辨率高于端部区域对应的探测分辨率，一方面可以在驾驶过程中更为关注的中央区域获得较高的探测分辨率，另一方面，端部区域探测率相对较低可以增加探测效率。
需要说明的是，在其他的应用场景中，还可以设置端部区域的扫描器件200具有较高的探测分辨率，例如，在驾驶过程中侧方停车时，相对于中央区域，更关注端部区域的探测信息，此时，可以切换扫描器件200的扫描方式，使扫描器件对端部区域扫描时采用高探测分辨率的扫描方式。
如图2所示，三个收发模块100采用同一扫描器件200进行扫描，为了获得不同的探测分辨率，所述扫描器件200根据第一扫描曲线利用所述第一收发模块111的多束发射光束进行扫描，并根据第二扫描曲线利用所述第二收发模 块112的多束发射光束进行扫描，所述第一扫描曲线的扫描频率大于所述第二扫描曲线的扫描频率。
例如：扫描器件200采用等时触发的方式进行扫描，利用第一收发模块111的发射光束进行扫描时采用第一时间间隔，利用第二收发模块112的发射光束进行扫描时采用第二时间间隔，第二时间间隔为第一时间间隔的两倍，从而可以使第一收发模块111获得的扫描点密度远大于第二收发模块112的扫描点密度，从而使中央区域获得较高的探测分辨率。在其他实施例中，还可以采用其他方式使两个区域的探测分辨率不同。
结合参考图10和图11，示出了本发明第二实施例激光雷达的局部视场示意图和子扫描视场示意图。
本发明实施例与第一实施例的相同之处不再赘述，与第一实施例的不同之处在于，本发明实施例中，所述发射装置发出的多束发射光束配置为形成面状光P，相应地，所述接收装置包括二维排列的多个探测单元。
因为面状光P在两个方向均具有较大的尺寸，可以增大局部视场。此外，面状光P的覆盖面积较大，对于相同的子扫描视场，可以减少扫描器件的扫描频率，从而提高扫描效率。
具体地，可以通过发射装置中的激光器或者匀光器改变发射光束的形状，获得面状光P。
例如：发射装置可以为二维排列的VCSEL阵列；接收装置可以采用二维排列的单光子探测器阵列。其他实施例中，还可以采用其他的方式获得所述面状光P。
请继续参考图12，示出了本发明第三实施例激光雷达的局部视场示意图。
本发明实施例与第一实施例的相同之处不再赘述，本发明实施例与第一实施例的相同之处不再赘述，与第一实施例的不同之处在于，本发明实施例中，扫描器件采用一维扫描方式进行扫描，所述扫描光束为线状光L，且沿竖直方向延伸，通过水平方向的一维扫描，可以使线状光L通过扫描获得长方形的子扫描视场403。进而通过多个子扫描视场403拼接形成总扫描视场，可以达到增大总扫描视场的目的。
具体地，扫描器件可以为转镜或摆镜，通过水平方向的扫描实现本实施例的一维扫描方式。
虽然本发明披露如上，但本发明并非限定于此。任何本领域技术人员，在不脱离本发明的精神和范围内，均可作各种更动与修改，因此本发明的保护范围应当以权利要求所限定的范围为准。

Claims (18)

  1. 一种激光雷达，其特征在于，包括：
    收发模块，所述收发模块配置为发出多束发射光束，形成局部视场；
    扫描器件，配置为利用所述多束发射光束进行扫描，形成多个所述局部视场，多个所述局部视场配置为拼接形成子扫描视场；
    多个所述子扫描视场配置为拼接形成激光雷达的总扫描视场。
  2. 如权利要求1所述的激光雷达，其特征在于，所述收发模块配置为同时发出所述多束发射光束，形成所述局部视场。
  3. 如权利要求1所述的激光雷达，其特征在于，所述扫描器件配置为利用所述收发模块的多束发射光束进行扫描，形成与所述收发模块对应的子扫描视场。
  4. 如权利要求1所述的激光雷达，其特征在于，所述扫描器件配置为根据扫描曲线进行扫描，使多个所述局部视场按照所述扫描曲线拼接形成所述子扫描视场。
  5. 如权利要求4所述的激光雷达，其特征在于，多个所述收发模块包括：探测第一区域的第一收发模块，和探测第二区域的第二收发模块，所述第一区域对应的探测分辨率高于所述第二区域对应的探测分辨率。
  6. 如权利要求5所述的激光雷达，其特征在于，所述扫描器件根据第一扫描曲线利用所述第一收发模块的多束发射光束进行扫描，并根据第二扫描曲线利用所述第二收发模块的多束发射光束进行扫描，所述第一扫描曲线的扫描频率大于所述第二扫描曲线的扫描频率。
  7. 如权利要求5或6所述的激光雷达，其特征在于，多个所述收发模块沿水平方向依次排布，位于中央区域的收发模块为所述第一收发模块，位于端部区域的收发模块为所述第二收发模块。
  8. 如权利要求1所述的激光雷达，其特征在于，所述多束发射光束经由扫描器件后形成扫描光束；所述扫描器件配置为通过扫描使所述扫描光束遍历所述子扫描视场。
  9. 如权利要求8所述的激光雷达，其特征在于，所述扫描器件还配置为使多个所述收发模块分别对应的扫描光束通过扫描遍历所述总扫描视场。
  10. 如权利要求1所述的激光雷达，其特征在于，所述扫描器件，配置为利用所述多束发射光束进行等时触发扫描、等角度触发扫描以及等相位触发扫描中的一种或多种。
  11. 如权利要求1所述的激光雷达，其特征在于，所述多束发射光束经由扫描器件后投射至目标物，形成回波光束；
    所述收发模块还配置为探测所述回波光束。
  12. 如权利要求11所述的激光雷达，其特征在于，所述收发模块包括：发出多束发射光束的发射装置，和探测所述回波光束接收装置；
    所述发射装置发出的多束发射光束配置为形成线状光，所述接收装置包括一维排列的多个探测单元；或者，
    所述发射装置发出的多束光束配置为形成面状光，所述接收装置包括二维排列的多个探测单元。
  13. 如权利要求12所述的激光雷达，其特征在于，所述扫描器件配置为利用所述多束发射光束进行二维扫描，所述二维扫描包括：慢轴扫描方向和快轴扫描方向。
  14. 如权利要求13所述的激光雷达，其特征在于，所述快轴扫描方向为水平方向，所述慢轴扫描方向为竖直方向。
  15. 如权利要求13所述的激光雷达，其特征在于，所述发射装置发出的多束发射光束配置为形成线状光；
    所述线状光沿慢轴扫描方向延伸。
  16. 如权利要求15所述的激光雷达，其特征在于，所述扫描器件根据扫描曲线利用所述线状光进行扫描，使所述线状光遍历所述子扫描视场和/或所述总扫描视场。
  17. 如权利要求12所述的激光雷达，其特征在于，所述发射装置包括：发 射单元以及位于发射单元发光光路上的匀光元件。
  18. 如权利要求1所述的激光雷达，其特征在于，多个所述收发模块配置为分时发光。
PCT/CN2022/128702 2022-04-24 2022-10-31 激光雷达 WO2023207009A1 (zh)

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CN109597050A (zh) * 2018-11-16 2019-04-09 上海禾赛光电科技有限公司 一种激光雷达
CN109814086A (zh) * 2019-01-07 2019-05-28 上海禾赛光电科技有限公司 一种激光雷达
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CN109814086A (zh) * 2019-01-07 2019-05-28 上海禾赛光电科技有限公司 一种激光雷达
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