WO2021147520A1 - 激光雷达的发射单元、激光雷达以及测距方法 - Google Patents

激光雷达的发射单元、激光雷达以及测距方法 Download PDF

Info

Publication number
WO2021147520A1
WO2021147520A1 PCT/CN2020/133185 CN2020133185W WO2021147520A1 WO 2021147520 A1 WO2021147520 A1 WO 2021147520A1 CN 2020133185 W CN2020133185 W CN 2020133185W WO 2021147520 A1 WO2021147520 A1 WO 2021147520A1
Authority
WO
WIPO (PCT)
Prior art keywords
mode
lasers
laser
laser array
lidar
Prior art date
Application number
PCT/CN2020/133185
Other languages
English (en)
French (fr)
Inventor
梁峰
王瑞
向少卿
Original Assignee
上海禾赛科技股份有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 上海禾赛科技股份有限公司 filed Critical 上海禾赛科技股份有限公司
Priority to EP20914833.7A priority Critical patent/EP3995851A4/en
Publication of WO2021147520A1 publication Critical patent/WO2021147520A1/zh
Priority to US17/563,263 priority patent/US20220120867A1/en

Links

Images

Classifications

    • 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
    • G01S7/4814—Constructional features, e.g. arrangements of optical elements of transmitters alone
    • G01S7/4815—Constructional features, e.g. arrangements of optical elements of transmitters alone using multiple transmitters
    • 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
    • G01S17/10—Systems determining position data of a target for measuring distance only using transmission of interrupted, pulse-modulated waves
    • 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
    • G01S17/42—Simultaneous measurement of distance and other co-ordinates
    • 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
    • G01S7/483—Details of pulse systems
    • G01S7/484—Transmitters

Definitions

  • the present disclosure relates to the field of lidar, and in particular to a transmitting unit that can be used for lidar, a lidar including the transmitting unit, and a method for measuring distance using the lidar.
  • the optical axes of the receiving lens group and the transmitting lens group are generally not coincident.
  • This non-coaxial optical structure will cause the light emitted by the laser beam to be reflected by the target to reach the receiving lens group.
  • the detector When the detector is on the focal plane, the light spot will shift and diffuse on the detector according to the distance of the target. This shift and dispersion will affect the detection of the reflected light of the target by the detector. Spot shift and dispersion have a greater impact on high-beam lidar.
  • a high-beam lidar usually has multiple channels emitting and receiving at the same time during the detection process. Offset and dispersion will inevitably cause optical crosstalk between channels that emit at the same time. Especially for the measurement of nearby targets, it interferes with other channels that are sending and receiving at the same time. From the point cloud, it is the inaccurate range of the target and the poor channel consistency at close range.
  • Figure 1 shows an example of optical crosstalk between two channels of lidar due to spot offset.
  • a laser and a detector that match the field of view in the lidar setting to measure the distance constitute a channel, as shown in Figure 1.
  • the radar echo is close to the parallel light, and it will illuminate the detector D1 of channel A, as shown in the upper left of Figure 1, this is In an ideal situation.
  • the lidar When the lidar is used to detect objects in the vicinity of OB2, after the detection beam L0 emitted by the laser of channel A is reflected by the nearby objects, the radar echo cannot be approximated as parallel light, which occurs when it reaches the focal plane where the detector is located.
  • the spot offset and dispersion will illuminate the channel B detector D2 next to the channel A detector, as shown in the lower left in Figure 1. This spot offset and dispersion will cause optical crosstalk between the lidar channels.
  • the deviation and dispersion of the light spot become more obvious with the closer the distance, so the more lines used for the detection of near-distance targets, the more it affects the range accuracy and accuracy of the lidar.
  • the traditional method adopts the solution of combined distance and near-measuring radar, one of which is dedicated to measuring distant objects.
  • Another radar is dedicated to measuring nearby objects.
  • the present invention provides a laser radar transmitting unit, a laser radar including the transmitting unit, and a method of using the laser radar for distance measurement.
  • a laser radar transmitting unit includes:
  • the laser array is configured to emit a probe beam
  • the emission controller which is coupled to the laser array, is configured to control the laser array to emit the first probe beam in a first mode, and is configured to control the laser array to emit the first detection beam in the first mode. Before or after emitting the first probe beam in the second mode,
  • the first mode includes: controlling n lasers in the laser array to emit light, where n is less than or equal to N, and N is the total number of lasers in the laser array; the second mode includes controlling the lasers in the laser array k lasers emit light, wherein the k lasers are selected from the n lasers, and k is less than n.
  • the first mode is a distance measurement mode
  • the second mode is a near measurement mode
  • the first mode includes: controlling the n lasers in the laser array to emit light at each horizontal angular position of the lidar; and the second mode includes: At the same horizontal angular position as the first mode, the k lasers in the laser array are controlled to emit light.
  • the emission controller is configured to divide the laser array into m groups and emit light sequentially, where m is an integer and m>1, and the emission controller is configured to control each group of laser arrays to emit light sequentially.
  • a mode emits a first probe beam, and is configured to control each group of laser arrays to emit a second probe beam in a second mode before or after emitting the first probe beam in the first mode.
  • the k lasers emitting the second probe beam are different from each other, and the second mode is based on the lidar
  • the s horizontal angles of is a periodic cycle, where s is an integer greater than or equal to 2.
  • the first probe beam and the second probe beam have different pulse codes.
  • the laser array is a laser array formed by a single laser or a linear laser or an area laser, and the laser includes an edge emitting laser or a vertical cavity surface emitting laser.
  • the present invention also provides a laser radar, including:
  • the transmitting unit as described above;
  • a receiving unit includes a detector array configured to receive the echoes of the first and second probe beams reflected by the target, and convert the echoes into electrical signals;
  • the processing unit coupled to the detector array, is configured to read the electrical signal output by the detector array, calculate the distance between the target and the lidar based on the electrical signal, and determine that the electrical signal corresponds to The first detection beam or the second detection beam, and point cloud data is generated according to the distance and the judgment result.
  • the present invention also provides a distance measurement method using the lidar as described above, which includes:
  • S201 Control the laser array to emit a first detection beam in a first mode, where the first mode includes: controlling n lasers in the laser array to emit light, where n is less than or equal to N, and N is the laser in the laser array total;
  • S202 Control the laser array to emit a second probe beam in a second mode before or after emitting the first probe beam in the first mode, where the second mode includes controlling k lasers in the laser array Emitting light, wherein the k lasers are selected from the n lasers, and k is less than n;
  • S203 Receive the echo of the detection beam reflected by the target object and convert the echo into an electrical signal, and calculate the distance between the target object and the lidar according to the electrical signal;
  • S205 Generate point cloud data according to the distance and the judgment result.
  • the first mode is a distance measurement mode
  • the second mode is a near measurement mode
  • the first mode includes: controlling the n lasers in the laser array to emit light at each horizontal angular position of the lidar; and the second mode includes: At the same horizontal angular position as the first mode, the k lasers in the laser array are controlled to emit light.
  • the laser arrays are divided into m groups to emit light sequentially, m is an integer and m>1, each group of laser arrays is controlled to emit the first detection beam in a first mode, and each group of laser arrays is controlled The second probe beam is emitted in the second mode before or after the first probe beam is emitted in the first mode.
  • the k lasers emitting the second probe beam are different from each other, and the second mode is based on the lidar
  • the s horizontal angles of is a periodic cycle, where s is an integer greater than or equal to 2.
  • the first probe beam and the second probe beam have different pulse codes.
  • the step S204 includes: judging that the electrical signal corresponds to the first probe beam or the second probe beam through a time window during which the echo is received.
  • the embodiment of the present invention proposes a scheme of independently and alternately performing the distance measurement and the near measurement of the lidar.
  • all channels or most of the channels
  • the embodiment of the present invention proposes a scheme of independently and alternately performing the distance measurement and the near measurement of the lidar.
  • the lidar has a high beam and high horizontal angular resolution when measuring medium and long distances, and a low beam and low horizontal angular resolution when measuring short distances. But this will not significantly reduce the resolution ability of nearby targets, because the detection and recognition of nearby targets requires low wire harness and horizontal resolution. Too high wire harness and too high angular resolution are in the near future. There may even form a stack of light spots, resulting in redundancy.
  • Figure 1 shows a schematic diagram of spot drift occurring during close-range detection of lidar
  • Fig. 2 shows a schematic diagram of a transmitting unit of a lidar according to an embodiment of the present invention
  • Fig. 3 shows a schematic diagram of a laser array according to an embodiment of the present invention
  • Figure 4A shows the trajectory scanned by each laser beam of the lidar on a distant target
  • FIG. 4B shows a schematic diagram of stacking and redundancy of laser radar spots on nearby targets
  • Fig. 5 shows the logical arrangement (light-emitting timing) of multiple lasers of the laser array according to an embodiment of the present invention
  • FIG. 6 shows the lighting timing of the first mode and the second mode according to an embodiment of the present invention
  • FIG. 7 shows the lighting timing of the first mode and the second mode according to another embodiment of the present invention.
  • Figure 8 shows the logical arrangement (light-emitting timing) of the laser array at adjacent horizontal angular positions according to an embodiment of the present invention
  • Figure 9 shows a schematic diagram of a lidar according to an embodiment of the present invention.
  • Fig. 10 shows a schematic diagram of a method for distance measurement using lidar according to an embodiment of the present invention.
  • first and second are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined with “first” and “second” may explicitly or implicitly include one or more of the features. In the description of the present invention, “plurality” means two or more than two, unless otherwise specifically defined.
  • the terms “installation”, “connected”, and “connected” should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection.
  • Connected or integrally connected It can be mechanically connected, or electrically connected or can communicate with each other; it can be directly connected or indirectly connected through an intermediate medium, which can be the internal communication of two components or the interaction of two components relation.
  • an intermediate medium which can be the internal communication of two components or the interaction of two components relation.
  • the "on” or “under” of the first feature of the second feature may include the first and second features in direct contact, or may include the first and second features Not in direct contact but through other features between them.
  • the "above”, “above”, and “above” of the first feature on the second feature include the first feature directly above and diagonally above the second feature, or it simply means that the first feature is higher in level than the second feature.
  • the “below”, “below” and “below” of the first feature of the second feature include the first feature directly above and diagonally above the second feature, or it simply means that the level of the first feature is smaller than the second feature.
  • the first aspect of the present invention relates to a laser emitting unit, for example, it can be used as a laser radar emitting unit, which will be described in detail below with reference to the accompanying drawings.
  • the transmitting unit 100 includes: a laser array 101 and a transmitting controller 102.
  • the laser array 101 includes a plurality of lasers, which are arranged on one or more substrates, and each laser can be individually driven and controlled to emit light.
  • FIG. 2 schematically shows a schematic diagram in which a plurality of lasers included in the laser array 101 are arranged on a substrate (for example, a circuit board).
  • the laser array 101 includes, for example, four columns of lasers, and a total of 30 lasers. Those skilled in the art can easily understand that the present invention is not limited to this.
  • the laser array 101 can include more or fewer lasers, and the physical arrangement of the lasers can be set arbitrarily as required.
  • the transmitting unit 100 further includes a transmitting lens (not shown) for modulating (collimating) each laser beam emitted by the laser into parallel light and emitting it to the environmental space around the lidar
  • each laser in the laser array 101 is preferably located at a different height on the focal plane of the emitting lens, and corresponds to a different vertical field of view after being emitted by the emitting lens.
  • Fig. 3 shows a laser array 101 according to another embodiment of the present invention.
  • the laser array 101 includes a plurality of substrates 1012 and lasers 1011 arranged on each substrate 1012, wherein each laser 1011 at a different height of the focal plane of the emitting lens corresponds to a different vertical field of view of the lidar.
  • the emission controller 102 is coupled to the laser array 101 and is configured to control the lasers in the laser array 101 to emit light.
  • the emission controller 102 may include a high-voltage unit and a logic control unit.
  • the high-voltage unit is used to generate the high voltage required to drive the laser to emit light
  • the logic control unit is used to control the light-emitting timing and logic of the laser array 101. This will be described in detail below.
  • the lidar of the present invention is angularly triggered, and at each horizontal angular position of the lidar, the lidar completes a complete ranging process.
  • the horizontal angle resolution of the lidar is 0.2°
  • each horizontal angle of the lidar is every 0.2°, starting from 0°, and triggering the angle at 0°, 0.2°, 0.4°... to complete a complete ranging process.
  • the laser beam When detecting a nearby target, the laser beam radiates a short divergence distance, so the trajectories scanned by each laser beam on the target are dense, so there is serious spot stacking and redundancy, while considering the drift and drift of the short-range spot Dispersion, that is, the waste of the laser beam will affect the measurement accuracy of the lidar.
  • the emission controller 102 is configured to use more lasers to emit light in the first mode to improve the resolution of distant targets; at the same time, in the second mode, use more lasers.
  • the first mode includes: controlling n lasers in the laser array 101 to emit light, where n is less than or equal to N, and N is the total number of lasers in the laser array; the second mode includes controlling the lasers
  • the k lasers in the array emit light, wherein the k lasers are selected from the n lasers, and k is less than n.
  • the n is equal to the total number N of lasers in the laser array, and the second mode is preferably single-channel emission.
  • the n lasers emit light at the same time, and the k lasers also emit light at the same time.
  • Luminous further reducing channel crosstalk.
  • the first mode includes: at each horizontal angular position of the lidar, controlling the n lasers in the laser array to emit light; the second mode includes : Control the k lasers in the laser array to emit light at the same horizontal angular position as the first mode.
  • the horizontal angle resolution of the lidar mentioned above is 0.2°, and each horizontal angle of the lidar is every 0.2°, starting from 0°, and triggering at 0°, 0.2°, 0.4°... That is, at each angle of 0°, 0.2°, 0.4°...
  • the laser array 101 performs the first mode and the second mode of luminous ranging.
  • the horizontal angular resolution of the lidar can also be 0.1° or other angles, depending on the detection requirements. Make settings.
  • the high-beam lidar can usually reach 40, 64, 128 and higher line numbers, due to the detection distance and horizontal angle resolution. Constrained by the rate, high-beam lidar usually needs to be divided into multiple groups to emit light in sequence, and each group of laser arrays is called sub-laser arrays.
  • the laser array is divided into m groups to emit light sequentially, m is an integer and m>1, and the emission controller is configured to control each group of laser arrays to emit the first detection in the first mode. And configured to control each group of laser arrays to emit a second detection beam in a second mode before or after emitting the first detection beam in the first mode.
  • the m sub-laser arrays all emit light in a pattern.
  • the sequence of the first mode and the second mode of the m sub-arrays is the same. For example, for the m sub-laser arrays, the first mode is performed first, and then the second mode is performed.
  • Sequential lighting of m groups means that in chronological order, the next group of operations can be performed after one group is completed.
  • the lasers emitting light in each mode may emit light simultaneously, and the lasers emitting light in the second mode may emit light simultaneously.
  • part of the lasers emitting in the second mode of the sub-laser array may be equal to zero.
  • FIG. 5 shows the logical arrangement (light emitting timing) of multiple lasers of the laser array 101, where the laser array 101 includes 128 lasers as an example for description.
  • the laser array 101 includes 128 lasers as an example for description.
  • multiple lasers need to emit light in parallel when controlling the light-emitting timing.
  • 128 lasers can be divided into 16 groups, each group of 8 lasers emit light at the same time, a total of 16 shots, which can complete the emission of 128 lasers.
  • the horizontal direction is the sequence of the light-emitting moments, and the lasers are divided into 16 groups, each with 8 lasers.
  • the 8 lasers that emit light at the first moment are numbered 1-1, 1-2,..., 1-7, 1-8, and the 8 lasers that emit light at the 16th moment are numbered 16-1, 16-2,..., 16-7, 16-8, the lasers that emit light at other times are numbered similarly, so I won't repeat them here.
  • the 128 lasers are triggered by the same horizontal angle.
  • the laser array 101 is a laser array formed by a single laser or a linear laser or an area laser, and the laser includes an edge emitting laser or a vertical cavity surface emitting laser or a combination of the two.
  • the lasers are numbered and arranged according to the logical sequence of light emission in FIG. 5, which may be consistent with the physical arrangement of the lasers shown in FIGS. 2 and 3, or may be inconsistent.
  • two lasers located in the same column in FIG. 2 may be at different light-emitting moments in FIG. 5, and these are all within the protection scope of the present invention.
  • the first mode and the second mode are relative concepts, wherein the number of lasers used in the first mode is more than the number of lasers used in the second mode.
  • the first mode is the telemetry mode, using all lasers in the laser array 101 to emit light alternately for detection;
  • the second mode is the proximity mode, using some of the lasers in the laser array 101 Illumination alternately for detection. It is easy for those skilled in the art to understand that even in the first mode, instead of using all lasers to emit light alternately, part of the lasers can be used to emit light (that is, n is less than N), as long as the number of emitting lasers in the first mode is more than that in the second mode. The number of emitting lasers is sufficient. For convenience and clarity, the following description will take the first mode of using all lasers as an example for description.
  • the emission controller 102 may control the k lasers in the laser array so that the k lasers emit the first detection beam in the first mode before or after the first detection beam is emitted in the second mode.
  • the mode emits a second probe beam.
  • the emission controller 102 may preset the selection method to select or randomly select the k lasers to be emitted according to the second mode, and before or after the k lasers emit according to the first mode, perform one emission according to the second mode. .
  • Figure 5 shows the second mode of transmission after the first mode of transmission.
  • 8 lasers are selected, and their numbers are 1-1, 3-1, 4-2, 5-3, 7-4, 9-5, 10- 3. 12-1.
  • the 8 lasers will add another near-measuring emission (the second mode) after completing the distance measurement.
  • Figure 6 shows the measurement of one of the lasers.
  • the green block is the long-distance emission time window
  • the yellow block is the near-detection emission time window. Therefore, in the 128-channel alternate luminous distance measurement, 8 near-measuring shots were inserted.
  • each proximity measurement emission is preferably a single-channel emission, that is, only one laser emits according to the second mode at the same time.
  • the present invention is not limited to the number of selected partial lasers.
  • Figure 5 shows 8 lasers for emitting the second probe beam. The specific number can be more than 8 or less than 8, depending on the desired proximity measurement. The horizontal angle resolution is determined.
  • the part of the lasers emitted in the second mode may be preset or generated in real time. For example, for the 8 lasers at each light-emitting moment in Fig. 5, one laser can be randomly selected to implement the second mode of emission, and these are all within the protection scope of the present invention.
  • the emission of the second mode is located after the emission of the first mode.
  • the transmission in the second mode can also be performed before the transmission in the first mode, as shown in FIG. 7.
  • the k lasers are emitted according to the first mode, they are emitted according to the second mode to detect nearby targets. I won't repeat them here.
  • the distance measurement mode that is, the distance measurement result is used to provide the three-dimensional point cloud data of the radar distance measurement
  • the laser emitted by the distance measurement mode The number is large.
  • the distance between the target and the lidar is within 5m, it is in the proximity mode (that is, the ranging result is used to provide the three-dimensional point cloud data of the radar proximity measurement), and the number of lasers emitted by the proximity mode is small.
  • the present invention is not limited to the above specific values, but can also be modified and adjusted according to specific conditions.
  • the distance preset value can be determined according to the distance-varying spot offset and dispersion obtained by the lens parameters of the lidar and the system's ability to recognize the output signal of the detector. .
  • the setting of the distance preset value is used as a reference for outputting three-dimensional point cloud data of the lidar, which will be described in detail below.
  • the first probe beam and the second probe beam may have different pulse codes.
  • both the first probe beam and the second probe beam can use double pulses, but the double pulses of the two have different time intervals for encoding, so that the receiving end can distinguish that the echo corresponds to the first echo according to the interval of the echo pulse.
  • the first probe beam is still the second probe beam.
  • the first detection beam and the second detection beam can also be distinguished by the signals read by the different time windows reserved by the detectors corresponding to each channel.
  • the first mode If the first probe beam is used for long-distance measurement, the detector (after the channel laser emits light in the first mode) reserves a longer first time window for the echo reception of the first probe beam reflected from the target. After the mode completes the distance measurement, a shorter second time window is reserved for the echo reception of the second probe beam in the second mode near measurement. Therefore, the first time window and the second time window signal of the detectors of each channel are read. Distinguish between the first probe beam and the second probe beam.
  • Lidar usually has a rotation axis, which can rotate in a plane around the rotation axis.
  • the rotation axis is along the vertical direction
  • the lidar can rotate in the horizontal plane
  • the laser is driven to emit a detection beam.
  • Lidar has a certain angular resolution, such as 0.1° or 0.2°.
  • Each horizontal angular position of the lidar (for example, at the interval of the horizontal angular resolution of the lidar) emits a probe beam.
  • Figure 8 shows the laser radar's
  • the angular resolution is 0.1°, that is, a detection is performed every 0.1°.
  • the first mode includes: at each horizontal angular position of the lidar, controlling the n lasers in the laser array to emit light; the second mode includes: At the same horizontal angular position as the first mode, control part of the lasers in the laser array to emit light.
  • the k lasers also perform the second mode of luminescence detection.
  • 128 lasers are divided into 16 groups to emit light, and each group of laser arrays (ie, sub-laser arrays) includes 8 lasers.
  • control n lasers in each group of laser arrays to emit light where the maximum value of n is the total number of lasers in each group of laser arrays (sub-laser arrays), for example, control the group of 8 lasers in the first mode
  • the lasers all emit light
  • the second mode controls only a few of each group of laser arrays to emit light, such as one, in chronological order, and the next group of operations is performed after one group is completed.
  • the laser numbers of the second mode are 1-1, 3-1, 4-2, 5-3, 7-4, 9-5, 10-3, 12-1 (refer to Figure 5), where the lasers of the second mode are all selected from different groups, thereby further reducing the possibility of optical crosstalk.
  • the 128 lasers are uniformly grouped, of course, they can also be non-uniformly grouped according to actual conditions, that is, the number of lasers in each group of laser arrays can be different.
  • the part of the lasers emitting the second probe beam are different from each other, and the second mode is based on s levels of the lidar.
  • the angle is a periodic cycle, where s is an integer greater than or equal to 2.
  • the numbers of the lasers at 0.0° are 1-1, 3-1, 4-2, 5-3, 7-4, 9-5, 10-3, 12 -1;
  • the numbers of the lasers at 0.1° are 1-2, 2-7, 3-6, 5-5, 7-2, 10-7, 13-4, respectively , 14-6, the part of the lasers that emit light in the second mode at 0.0 and 0.1° do not overlap.
  • the selection method of the second mode laser should try to ensure that the 128 lasers in different positions are used in batches as much as possible , So that the field of view and resolution of short-range detection are fully guaranteed.
  • the distance measurement of this lidar is 128 lines and the horizontal angular resolution is 0.1°, while the near measurement is 32 lines and the horizontal angular resolution is 0.4°.
  • Different coded pulses can be used in distance measurement and near measurement to distinguish the echo signals of distance measurement and near measurement to avoid misidentification.
  • Fig. 8 illustrates the arrangement of the near and far light emitting sequence of the 128-line radar, where the green block is the light emitting time window for far distance measurement, and the yellow block is the light emitting time window for near distance measurement. The near measurement is arranged after the channel completes the distance measurement, and then the light is emitted again to perform the near measurement.
  • each near-measuring is preferably a single-channel luminescence.
  • select 16 different near-measuring channels In a 0.2° cycle, 32 near-detection channels were sent and received. Therefore, the distance measurement of this lidar is 128 lines and the horizontal angular resolution is 0.1°, while the near measurement is 32 lines and the horizontal angular resolution is 0.2°.
  • the second mode may not be 32 lines, but a higher or lower harness, which can be set according to the actual situation.
  • the high-line beam lasers of the present invention do not necessarily emit light in groups in sequence, and may emit light simultaneously.
  • the laser array 101 includes 128 lasers in the first mode.
  • 128 lasers can simultaneously emit the first detection beam (through appropriate photoelectric isolation, for providing distance measurement data (for the influence of distance measurement optical crosstalk) Smaller), and in the second mode, for example, select multiple lasers (for example, 8 or 16 with relatively separated vertical field of view, less than 128) to emit the second probe beam, for example, for near measurement (providing near measurement data ).
  • Such embodiments are also within the protection scope of the present invention.
  • the embodiment of the present invention proposes a scheme of independently and alternately performing the distance measurement and the near measurement of the lidar.
  • all channels or most of the channels
  • the horizontal scanning frequency is reduced, so that only a few channels or even a few channels are emitted at the same time each time.
  • Single-channel light emission so that it can greatly reduce close-range optical crosstalk, or even completely avoid optical crosstalk.
  • the lidar has a high beam and high horizontal angular resolution when measuring medium and long distances, and a low beam and low horizontal angular resolution when measuring short distances. But this will not significantly reduce the resolution ability of nearby targets, because the detection and recognition of nearby targets requires low wire harness and angular resolution. Too high wire harness and too high horizontal angular resolution are There may even be a stack of light spots nearby, resulting in redundancy.
  • the second aspect of the present invention relates to a laser radar, as shown in FIG. 9, and is described below with reference to the accompanying drawings.
  • the lidar 10 includes a transmitting unit 100, a receiving unit 120, and a processing unit 130 as described above.
  • the transmitting unit 100 may alternately emit the first detection beam and the second detection beam L1/L2 to the outside of the lidar 10 according to the first mode and the second mode, wherein the number of lasers used in the first mode is more than that in the first mode.
  • the number of lasers used in the two modes for example, for distance measurement and near measurement respectively.
  • the first detection beam and the second detection beam are diffusely reflected on the target OB, and the radar echo L1'/L2' returns to the lidar and is received by the receiving unit 120.
  • the receiving unit 200 includes a detector array, such as an array of detectors such as APD, SiPM, SPAD, etc.
  • the detector array is configured to receive the echoes of the first detection beam and the second detection beam reflected by the target, and The echo is converted into an electrical signal.
  • the processing unit 130 is coupled to the detector array and is configured to read the electrical signal output by the detector array, and determine that the electrical signal corresponds to the first detection beam or the second detection beam, and based on the electrical signal The signal calculates the distance of the target object, and generates point cloud data according to the distance and the judgment result.
  • the receiving unit 120 and the processing unit 130 can be configured as separate modules, or can be integrated into an integrated module, which are all within the protection scope of the present invention.
  • the processing unit 130 can be coupled to the transmitting unit 100, so that the first detection beam and the second detection beam can be recorded.
  • the emission time of the probe beam is also feasible to know the emission time by other means, which will not be repeated here.
  • the distance measurement and the near measurement of the high-beam laser radar can be alternately performed independently.
  • the highest wire beam and angular resolution are used for the distance measurement, and the lower wire beam and angular resolution are used for the near measurement. , Which reduces the number of channels that emit light at the same time during proximity measurement, thereby reducing optical crosstalk at close range.
  • the third aspect of the present invention relates to a method 200 for performing distance measurement using the lidar 10 as described above, as shown in FIG. 10, which is described below with reference to the accompanying drawings.
  • step S201 controlling the laser array to emit a first detection beam in a first mode, where the first mode includes: controlling n lasers in the laser array to emit light, where n is less than or equal to N, and N is the laser array
  • the total number of lasers in the middle; the first mode is, for example, a telemetry mode, and it is preferable to enable all the lasers in the laser array to sequentially emit the first detection beam.
  • step S202 controlling part of the lasers in the laser array to emit a second probe beam in a second mode before or after emitting the first probe beam in the first mode.
  • the second mode includes controlling k lasers in the laser array to emit light, wherein the k lasers are selected from the n lasers, and k is less than n; the second mode is, for example, a proximity mode, such as Part of the lasers in the laser array can be activated to emit the second probe beam in sequence.
  • the n is equal to the total number N of lasers in the laser array, and the second mode is preferably single-channel emission.
  • the n lasers emit light at the same time, and the k lasers also emit light at the same time.
  • TOF time-of-flight ranging method
  • step S204 it is determined that the electrical signal corresponds to the first detection beam or the second detection beam.
  • step S205 generate point cloud data according to the distance and the judgment result. For example, when it is determined that the electrical signal corresponds to the first detection beam (distance measurement mode), if the distance between the target and the lidar calculated according to the electrical signal is less than the preset distance (for example, 5 meters), the The electrical signal is used for long-distance measurement. At this time, you can choose not to use or discard the electrical signal instead of generating point cloud data. Conversely, when it is determined that the electrical signal corresponds to the second probe beam (near-finding mode), if the distance between the target and the lidar calculated based on the electrical signal is greater than the preset distance (for example, 5 meters), the The electrical signal is used for proximity measurement. At this time, you can choose not to use or discard the electrical signal instead of generating point cloud data. Use the data splicing of the long-distance and near-measurement modes to generate more accurate 3D point cloud data.
  • the step S202 includes: controlling the k lasers in the laser array to emit the second detection beam in the second mode after emitting the first detection beam in the first mode, such as Shown in Figure 5 and Figure 6.
  • the step S202 includes: controlling part of the lasers in the laser array to emit the second detection beam in the second mode before emitting the first detection beam in the first mode, as shown in FIG. 7.
  • the first mode includes: at each horizontal angular position of the lidar, controlling the n lasers in the laser array to emit light; the second mode includes: At the same horizontal angular position as the first mode, the k lasers in the laser array are controlled to emit light.
  • the laser arrays are divided into m groups to emit light sequentially, m is an integer and m>1, each group of laser arrays is controlled to emit the first detection beam in the first mode, and each group of lasers is controlled The array emits a second probe beam in a second mode before or after emitting the first probe beam in the first mode.
  • the part of the lasers emitting the second probe beam are different from each other, and the second mode is based on the lidar's
  • the s horizontal angles are periodic cycles, where s is an integer greater than or equal to 2.
  • the first detection beam and the second detection beam have different pulse codes, so that according to the different pulse codes, it can be distinguished at the receiving end that the radar echo corresponds to the first detection beam or It is the second detection beam to perform corresponding processing operations.
  • the step S204 includes: judging that the electrical signal corresponds to the first probe beam or the second probe beam through a time window during which the echo is received.
  • the first probe beam and the second probe beam may have different pulse codes.
  • both the first probe beam and the second probe beam can use double pulses, but the double pulses of the two have different time intervals for encoding, so that the receiving end can distinguish that the echo corresponds to the first echo according to the interval of the echo pulse.
  • the first probe beam is still the second probe beam.
  • the first detection beam and the second detection beam can also be distinguished by the signals read by the different time windows reserved by the detectors corresponding to each channel.
  • the first mode If the first probe beam is used for long-distance measurement, the detector (after the channel laser emits light in the first mode) reserves a longer first time window for the echo reception of the first probe beam reflected from the target. After the mode completes the distance measurement, a shorter second time window is reserved for the echo reception of the second probe beam in the second mode near measurement. Therefore, the first time window and the second time window signal of the detectors of each channel are read. Distinguish between the first probe beam and the second probe beam.
  • the present invention proposes a scheme of independently and alternately performing the distance measurement and the near measurement of the lidar.
  • all channels are turned on to measure mid-distance targets; during near measurement, only some channels are turned on, and the horizontal scanning frequency is reduced, so that only a few channels or even a single channel emit light at the same time each time. It can greatly reduce short-range optical crosstalk, and even completely avoid optical crosstalk.
  • the lidar has a high beam and high horizontal angular resolution when measuring medium and long distances, and a low beam and low horizontal angular resolution when measuring short distances. But this will not significantly reduce the resolution ability of nearby targets, because the detection and recognition of nearby targets requires low wire harness and horizontal angular resolution. Too high wire harness and high angular resolution are There may even be a stack of light spots nearby, resulting in redundancy.
  • all channels are turned on, which can be understood as all the lasers emit light in turn during the long-distance measurement, and within the range of the long-distance measurement, the time window corresponding to the detectors of all channels obtains valid data.
  • opening some channels can be understood as part of the lasers that emit light in turn during the near-measuring.
  • the time window corresponding to the detectors of some channels obtains valid data.
  • Different codes can be used in distance measurement and near measurement to distinguish the echo signals of distance measurement and near measurement to avoid misidentification.
  • the distance measurement and the near measurement of the high-beam lidar are performed alternately and independently.
  • the highest wire beam and resolution are used in the distance measurement, and the lower wire beam and resolution are used in the near measurement, so that the light emitting at the same time is used for the near measurement.
  • the number of channels is reduced, thereby reducing optical crosstalk at close range.
  • the distance measurement and near measurement of high-beam lidar are alternately performed independently.
  • the highest harness and resolution are used for distance measurement, and the lower harness and resolution are used for near measurement, so that the light will be illuminated at the same time during near measurement.
  • the number of channels is reduced.
  • lidar can use more channels to emit light in parallel to improve the resolution of distant targets; at the same time, use fewer channels to measure nearby targets, and there are as few luminous channels as possible when measuring near. Reduce the interference between the simultaneous light-emitting channels, so that the accuracy of the close measurement is greatly improved.

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

一种激光雷达（10）的发射单元（100），包括激光器阵列（101），可发射出探测光束（L1，L2）；发射控制器（102），与激光器阵列（101）耦接，控制激光器阵列（101）以第一模式发出第一探测光束（L1），并控制激光器阵列（101）在以第一模式发出第一探测光束（L1）之前或之后以第二模式发出第二探测光束（L2），第一模式包括控制激光器阵列（101）中的n个激光器（1011）发光，n小于等于N；第二模式包括，控制激光器阵列（101）中的k个激光器（1011）发光，其中k个激光器（1011）选自n个激光器（1011），k小于n。将激光雷达（10）的测远和测近独立交替进行的方案。在测远时，所有通道，或大部分通道都打开，测量中远处目标物（OB）；在测近时，只采用打开部分通道，这样就能保证测远高分辨率的同时极大地减少近距光串扰。

Description

激光雷达的发射单元、激光雷达以及测距方法 技术领域
本公开涉及激光雷达领域，尤其涉及一种可用于激光雷达的发射单元、包括该发射单元的激光雷达以及利用该激光雷达进行测距的方法。
背景技术
在现有很多激光雷达的结构中，接收透镜组和发射透镜组的光轴一般是不重合的，这种非同轴光学结构会导致激光器发射光束被目标物反射后的光在到达接收透镜组焦平面上的探测器时，光斑会按照目标物的距离在探测器上发生偏移和弥散，这种偏移和弥散会影响探测器对目标物反射光的探测。光斑偏移和弥散对高线束激光雷达影响更大。一个高线束的激光雷达，在探测过程中一般都会有多个通道同时发光和接收，偏移和弥散会使得同时发光的通道之间不可避免的会产生光串扰。尤其是对于近处目标物的测量，干扰到同时收发的其他通道，从点云上看就是近距离时目标物测距不准且通道一致性差。
图1示出了激光雷达两个通道间由于光斑偏移造成光串扰的示例。在激光雷达设定测远处视场匹配的一个激光器和一个探测器即构成一个通道，如图1所示，对于激光雷达的通道A和通道B，当激光雷达用于探测远处的物体时，通道A的激光器发出的探测光束L0被远处目标物OB1反射后，雷达回波接近于平行光，会照射到通道A的探测器上D1，如图1中左上方所示的，这是比较理想的情况，。而当激光雷达用于探测近处OB2的物体时，通道A的激光器发出的探测光束L0被近处目标物反射后，雷达回波不能近似为平行光，在到达探测器所在的焦平面时发生光斑偏移和弥散，会照射到通道A探测器旁边的通道B探测器上D2，如图1中左下方所示的，这种光斑的偏移和弥散会造成激光雷达通道间的光串扰，光斑的偏移和弥散随距离越近越明显，因此对于近距目标物探测使用的线数越多，越影响激光雷达的测距精度和准确性。
为了避免同一雷达在测量远近物体时由于光斑的偏移和弥散导致测距不准的现象，传统方法采用了测远、测近组合式雷达的解决方案，其中一台雷达专门测量远处的物体，另一台雷达专门测量近处的物体，这样虽然可以改善近距测量性能，但增加了系统成本，安装和调试的困难。
背景技术部分的内容仅仅是公开人所知晓的技术，并不当然代表本领域的现有 技术。
发明内容
本发明提供一种激光雷达的发射单元、包括该发射单元的激光雷达以及利用该激光雷达进行测距的方法。
一种激光雷达的发射单元包括：
激光器阵列，配置成可发射出探测光束；
发射控制器，所述发射控制器与所述激光器阵列耦接，配置成可控制所述激光器阵列以第一模式发出第一探测光束，并配置成可控制所述激光器阵列在以所述第一模式发出第一探测光束之前或之后以第二模式发出第二探测光束，
其中所述第一模式包括：控制所述激光器阵列中的n个激光器发光，n小于等于N，N为所述激光器阵列中激光器的总数；所述第二模式包括，控制所述激光器阵列中的k个激光器发光，其中所述k个激光器选自所述n个激光器，k小于n。
根据本发明的一个方面，其中所述第一模式为测远模式，所述第二模式为测近模式。
根据本发明的一个方面，其中所述第一模式包括：在所述激光雷达的每个水平角位置处，控制所述激光器阵列中的所述n个激光器发光；所述第二模式包括：在与所述第一模式相同的所述水平角位置处，控制所述激光器阵列中的所述k个激光器发光。
根据本发明的一个方面，所述发射控制器配置成将所述激光器阵列分为m组依序发光，m为整数且m>1，所述发射控制器配置成可控制每组激光器阵列以第一模式发出第一探测光束，并配置成可控制所述每组激光器阵列在以所述第一模式发出第一探测光束之前或之后以第二模式发出第二探测光束。
根据本发明的一个方面，其中在所述激光雷达的两个相邻水平角位置处，发射所述第二探测光束的所述k个激光器互不相同，所述第二模式以所述激光雷达的s个水平角为周期循环，其中s为大于等于2的整数。
根据本发明的一个方面，其中所述第一探测光束和第二探测光束具有不同的脉冲编码。
根据本发明的一个方面，其中所述激光器阵列为由单个激光器或线阵激光器或面阵激光器形成的激光器阵列，所述激光器包括边发射型激光器或垂直腔面发射激 光器。
本发明还提供一种激光雷达，包括：
如上所述的发射单元；
接收单元，所述接收单元包括探测器阵列，配置成可接收所述第一探测光束和第二探测光束被目标物反射的回波，并将所述回波转换为电信号；和
处理单元，耦接到所述探测器阵列，配置成可读取所述探测器阵列输出的电信号，根据所述电信号计算目标物与激光雷达间的距离，并判断所述电信号对应于第一探测光束或第二探测光束，并根据所述距离和所述判断结果生成点云数据。
本发明还提供一种使用如上所述的激光雷达进行测距的方法，包括：
S201：控制所述激光器阵列以第一模式发出第一探测光束,其中所述第一模式包括：控制所述激光器阵列中的n个激光器发光，n小于等于N，N为所述激光器阵列中激光器的总数；
S202：控制所述激光器阵列在以所述第一模式发出第一探测光束之前或之后以第二模式发出第二探测光束，其中所述第二模式包括，控制所述激光器阵列中的k个激光器发光，其中所述k个激光器选自所述n个激光器，k小于n；
S203：接收探测光束被目标物反射的回波并将所述回波转换为电信号，根据所述电信号计算目标物与激光雷达间的距离；
S204：判断所述电信号对应于第一探测光束或第二探测光束；和
S205：根据所述距离和所述判断结果生成点云数据。
根据本发明的一个方面，其中所述第一模式为测远模式，所述第二模式为测近模式。
根据本发明的一个方面，其中所述第一模式包括：在所述激光雷达的每个水平角位置处，控制所述激光器阵列中的所述n个激光器发光；所述第二模式包括：在与所述第一模式相同的所述水平角位置处，控制所述激光器阵列中的所述k个激光器发光。
根据本发明的一个方面，所述激光器阵列分为m组依序发光，m为整数且m>1，控制每组激光器阵列以第一模式发出第一探测光束，并控制所述每组激光器阵列在以所述第一模式发出第一探测光束之前或之后以第二模式发出第二探测光束。
根据本发明的一个方面，其中在所述激光雷达的两个相邻水平角位置处，发射所述第二探测光束的所述k个激光器互不相同，所述第二模式以所述激光雷达的s 个水平角为周期循环，其中s为大于等于2的整数。
根据本发明的一个方面，其中所述第一探测光束和第二探测光束具有不同的脉冲编码。
根据本发明的一个方面，其中所述步骤S204包括：通过接收所述回波的时间窗口，判断所述电信号对应于第一探测光束或第二探测光束。
本发明的实施例中，通过将激光雷达的测远和测近独立交替进行，且减少测近的线束，来改善多线束激光雷达在测量近距目标物时同时发光通道较多引发的光串扰问题。基于上述分析，本发明的实施例提出将激光雷达的测远和测近独立交替进行的方案。在测远时，所有通道(或大部分通道)都打开，测量中远处目标物；在测近时，只采用打开部分通道，使得每次同时发光只有很少的通道甚至单通道发光，这样就能极大地减少近距光串扰，甚至完全规避光串扰。这样的话，激光雷达在测中远距离时为高线束、高水平角分辨率，测近距时为低线束、低水平角分辨率。但这并不会显著降低近处目标物的分辨能力，因为近处目标物的探测和识别，本身所需要的线束和水平分辨率就低，过高的线束和过高的角分辨率在近处甚至会形成光斑堆叠，产生冗余。
附图说明
构成本公开的一部分的附图用来提供对本公开的进一步理解，本公开的示意性实施例及其说明用于解释本公开，并不构成对本公开的不当限定。在附图中：
图1示出了激光雷达近距探测过程中发生光斑漂移的示意图；
图2示出了根据本发明一个实施例的激光雷达的发射单元的示意图；
图3示出了根据本发明一个实施例的激光器阵列的示意图；
图4A示出了激光雷达在远处目标物上各个激光束扫过的轨迹；
图4B示出了激光雷达在近处目标物上光斑存在堆叠和冗余的示意图；
图5示出了根据本发明一个实施例的激光器阵列的多个激光器的逻辑排布(发光时序)；
图6示出了根据本发明一个实施例的第一模式和第二模式的发光时序；
图7示出了根据本发明另一个实施例的第一模式和第二模式的发光时序；
图8示出了根据本发明一个实施例在相邻水平角位置处的激光器阵列的逻辑排布(发光时序)；
图9示出了根据本发明一个实施例的激光雷达的示意图；和
图10示出了根据本发明一个实施例的利用激光雷达进行测距的方法的示意图。
具体实施方式
在下文中，仅简单地描述了某些示例性实施例。正如本领域技术人员可认识到的那样，在不脱离本发明的精神或范围的情况下，可通过各种不同方式修改所描述的实施例。因此，附图和描述被认为本质上是示例性的而非限制性的。
在本发明的描述中，需要理解的是，术语"中心"、"纵向"、"横向"、"长度"、"宽度"、"厚度"、"上"、"下"、"前"、"后"、"左"、"右"、"竖直"、"水平"、"顶"、"底"、"内"、"外"、"顺时针"、"逆时针"等指示的方位或位置关系为基于附图所示的方位或位置关系，仅是为了便于描述本发明和简化描述，而不是指示或暗示所指的装置或元件必须具有特定的方位、以特定的方位构造和操作，因此不能理解为对本发明的限制。此外，术语"第一"、"第二"仅用于描述目的，而不能理解为指示或暗示相对重要性或者隐含指明所指示的技术特征的数量。由此，限定有"第一"、"第二"的特征可以明示或者隐含地包括一个或者更多个所述特征。在本发明的描述中，"多个"的含义是两个或两个以上，除非另有明确具体的限定。
在本发明的描述中，需要说明的是，除非另有明确的规定和限定，术语"安装"、"相连"、"连接"应做广义理解，例如，可以是固定连接，也可以是可拆卸连接，或一体地连接:可以是机械连接，也可以是电连接或可以相互通讯；可以是直接相连，也可以通过中间媒介间接相连，可以是两个元件内部的连通或两个元件的相互作用关系。对于本领域的普通技术人员而言，可以根据具体情况理解上述术语在本发明中的具体含义。
在本发明中，除非另有明确的规定和限定，第一特征在第二特征之"上"或之"下"可以包括第一和第二特征直接接触，也可以包括第一和第二特征不是直接接触而是通过它们之间的另外的特征接触。而且，第一特征在第二特征"之上"、"上方"和"上面"包括第一特征在第二特征正上方和斜上方，或仅仅表示第一特征水平高度高于第二特征。第一特征在第二特征"之下"、"下方"和"下面"包括第一特征在第二特征正上方和斜上方，或仅仅表示第一特征水平高度小于第二特征。
下文的公开提供了许多不同的实施方式或例子用来实现本发明的不同结构。为了简化本发明的公开，下文中对特定例子的部件和设置进行描述。当然，它们仅仅 为示例，并且目的不在于限制本发明。此外，本发明可以在不同例子中重复参考数字和/或参考字母，这种重复是为了简化和清楚的目的，其本身不指示所讨论各种实施方式和/或设置之间的关系。此外，本发明提供了的各种特定的工艺和材料的例子，但是本领域普通技术人员可以意识到其他工艺的应用和/或其他材料的使用。
以下结合附图对本发明的优选实施例进行说明，应当理解，此处所描述的优选实施例仅用于说明和解释本发明，并不用于限定本发明。
本发明的第一方面涉及一种激光的发射单元，例如可用作激光雷达的发射单元，下面参考附图详细描述。
如图2所示，发射单元100包括：激光器阵列101和发射控制器102。其中激光器阵列101包括多个激光器，设置在一个或多个基板上，每个激光器可以单独被驱动控制发光。图2中示意性示出了激光器阵列101包括的多个激光器设置在一个基板(例如电路板)，的示意图，激光器阵列101例如包括四列激光器，共计30个激光器。本领域技术人员容易理解，本发明不限于此，激光器阵列101可包括更多或更少数目的激光器，并且激光器的物理排布方式可以根据需要任意设定，例如也可以构思将多个激光器设置在多个基板上，如图3所示。根据本发明的一个实施例，所述发射单元100还包括发射透镜(未示出)，用于将激光器出射的每束激光束调制(准直)成平行光并出射到激光雷达周围的环境空间中，激光器阵列101中每个激光器优选位于发射透镜焦平面上的不同高度处，经发射透镜出射后对应不同的垂直视场。
图3示出了根据本发明另一个实施例的激光器阵列101。其中激光器阵列101包括多个基板1012以及布置在各个基板1012上的激光器1011，其中每个激光器1011在发射透镜焦平面的不同的高度处，分别对应于激光雷达的不同的垂直视场。
如图2所示，发射控制器102与所述激光器阵列101耦接，并配置成可控制所述激光器阵列101中的激光器进行发光。发射控制器102可包括高压单元和逻辑控制单元，其中高压单元用于产生驱动所述激光器发光需要的高压，逻辑控制单元用于控制所述激光器阵列101的发光时序和逻辑。下面详细描述。
在一个示例中，本发明的激光雷达为角度触发，在激光雷达的每个水平角位置处，激光雷达完成一次完整的测距过程。例如，激光雷达水平角分辨率为0.2°，激光雷达的每个水平角即每0.2°，从0°开始，在0°、0.2°、0.4°…进行角度触发完成一次完整的测距过程。以转速10Hz,水平角分辨率0.2°，200m测远为例，一 次测远飞行时间为1.34us，转过0.2°耗时55.6us，也就是说在这个时间内最多允许收发41次光(55.6/1.34＝41.5)，对于中高线数激光雷达，例如64、128线要满足高水平角分辨率，长距离的测远要求，就需要多通道同时发光。而且，水平角分辨率越高，测远要求越远，则同时发光通道的数量就越多。本发明的发明人发现：高线束激光雷达，通道排列密集，同时发光的通道数越多越容易产生光串扰。这种串扰对于探测较远处的目标物的影响尚可接受，但是当测量近处的目标物时，通道间的相互干扰非常严重。从点云上看就是近距离时目标物测距不准且通道一致性差。
如图4A和4B所示，高线束激光雷达在探测近处目标物时所有通道都发光测距的话竖直和水平角分辨率都是过剩的。如图4A所示，由于激光雷达不同线是放射发散的，当探测远处的目标物时，由于距离较远，所以在目标物上扫描的激光光斑能够清楚的间隔开。由于距离远，反射回雷达的激光，基本是平行光，光斑在焦面的位置受距离影响小，所以对远距离物体的扫描，此时能够最大化地利用激光雷达的全部通道和最大性能。而当探测近处的目标物时，激光束放射发散的距离短，因此在目标物上各个激光束扫过的轨迹密集，所以存在严重的光斑堆叠和冗余，同时考虑近距光斑的漂移和弥散，即浪费了激光束又会对于激光雷达的测量精度造成影响。
因此，根据本发明的实施例，所述发射控制器102配置成可以在第一模式下采用较多的激光器发光，提高对远处目标物的分辨率；同时，在第二模式下，采用较少通道来测量近处目标物，并且测近时同时发光通道尽可能少，优选的为单通道，以减少同时发光通道之间的干扰，使得近处测量的精度大大提高。具体的，所述第一模式包括：控制所述激光器阵列101中的n个激光器发光，n小于等于N，N为所述激光器阵列中激光器的总数；所述第二模式包括，控制所述激光器阵列中的k个激光器发光，其中所述k个激光器选自所述n个激光器，k小于n。优选的所述n等于所述激光器阵列中激光器的总数N，优选地第二模式为单通道发光,优选地所述n个激光器同时发光，所述k个激光器也同时发光。在本发明的一个实施例中，例如激光器阵列101中的激光器总数是8个(N＝8)，在第一模式控制所述激光器阵列101中的8个激光器发光，优选地所述8个激光器同时发光，在第二模式控制所述激光器阵列101中的2个激光器发光，优选地所述2个激光器同时发光，或者优选地在第二模式控制所述激光器阵列101中的1个激光器单通道发光，更进一步地减小通道串扰。
在本发明的一个实施例中，其中所述第一模式包括：在所述激光雷达的每个水 平角位置处，控制所述激光器阵列中的所述n个激光器发光；所述第二模式包括：在与所述第一模式相同的所述水平角位置处，控制所述激光器阵列中的所述k个激光器发光。例如上文中所述的激光雷达的水平角分辨率为0.2°，激光雷达的每个水平角即每0.2°，从0°开始，在0°、0.2°、0.4°…进行角度触发。即在每个角度0°、0.2°、0.4°…激光器阵列101执行第一模式和第二模式的发光测距，当然激光雷达的水平角分辨率也可以为0.1°或其它角度，根据探测需要进行设定。
上文中仅是激光器阵列101中包括8个激光器为示例简单说明第一模式和第二模式，高线束激光雷达通常可以达到40、64、128以及更高线数，由于受探测距离和水平角分辨率的制约，高线束激光雷达通常需要分多组按序进行发光，每组激光器阵列即子激光器阵列。
根据本发明的一个优选实施例，所述激光器阵列分为m组依序发光，m为整数且m>1，所述发射控制器配置成可控制每组激光器阵列以第一模式发出第一探测光束，并配置成可控制所述每组激光器阵列在以所述第一模式发出第一探测光束之前或之后以第二模式发出第二探测光束。在激光雷达的每个水平角位置处，所述m个子激光器阵列均按模式完成发光。优选地，这m个子阵第一模式和第二模式的先后顺序是一致的。例如对于这m子激光器阵列均先进行第一模式再进行第二模式。m组依序发光是指按时间顺序，一组完成后再进行下一组操作。优选地每个子激光器阵列中，每一模式发光的激光器可以是同时发光，第二模式发光的激光器可以是同时发光。根据本发明的一个实施例，如分组数m较多时，部分子激光器阵列第二模式发光的激光器可以等于0。
以下参考附图详细描述。
图5示出了激光器阵列101的多个激光器的逻辑排布(发光时序)，其中以激光器阵列101包括128个激光器为例进行说明。通常对于高线束的激光雷达，在控制发光时序时，需要将多个激光器并行发光。如图3所示，可以将128个激光器分为16组，每组8个激光器同时发光，一共发16次，可完成128个激光器的发射。图5中水平方向为发光时刻的顺序，将激光器分为16组，每组8个激光器。为方便起见，在第一时刻发光的8个激光器的编号为1-1、1-2、…、1-7、1-8，在第16时刻发光的8个激光器的编号为16-1、16-2、…、16-7、16-8，其余时刻发光的激光器进行类似编号，此处不再赘述。所述128个激光器由同一水平角触发。
根据本发明的一个实施例，所述激光器阵列101为由单个激光器或线阵激光器 或面阵激光器形成的激光器阵列，所述激光器包括边发射型激光器或垂直腔面发射激光器或二者的组合。
本领域技术人员容易理解，图5中是按照发光的逻辑顺序对激光器进行了编号和排布，其与图2和图3所示的激光器的物理排布可以保持一致，也可以是不一致的。例如图2中位于同一列的两个激光器，在图5中可以处于不同的发光时刻，这些都在本发明的保护范围内。
本发明中，所述第一模式和第二模式为相对的概念，其中第一模式使用的激光器的数目多于第二模式使用的激光器的数目。根据本发明的一个优选实施例，第一模式为测远模式，使用所述激光器阵列101中的全部激光器交替发光进行探测；第二模式为测近模式，使用所述激光器阵列101中的部分激光器交替发光进行探测。本领域技术人员容易理解，即使在第一模式下，代替使用全部激光器交替发光，也可以采用部分激光器发光(即n小于N)，只要第一模式下的发射激光器的数目多于第二模式下的发射激光器的数目即可。为方便和清楚起见，以下描述中将以第一模式采用全部激光器发光为例进行说明。
根据本发明的实施例，发射控制器102可控制所述激光器阵列中的所述k个激光器，使得这些所述k个激光器在所述第一模式发出第一探测光束之前或之后，以第二模式发出第二探测光束。所述发射控制器102可预先设置选择方法选择或者随机选择按照第二模式发射的所述k个激光器，当所述k个激光器按照第一模式发射之前或者之后，进行一次根据第二模式的发射。
图5示出了第二模式的发射在第一模式发射之后的情形。图5所示的包括128个激光器的发射单元中，选定8个激光器，其编号分别为1-1、3-1、4-2、5-3、7-4、9-5、10-3、12-1，在正常进行测远(第一模式)的过程中，这8个激光器完成测远后追加一次测近发射(第二模式)，图6中示出了其中一个激光器的测远发射和测近发射，其中绿色块为测远发光时间窗，黄色块为测近发光时间窗。因此在128个通道轮流发光测远中插入8次测近发射。另外，每次测近发射优选是单通道发光，即同一时刻仅有一个激光器按照第二模式发射。
另外，本发明不限于所选择的部分激光器的数目，图5中示出了8个激光器用于发射第二探测光束，具体数目可以多于8个或少于8个，根据所希望的测近水平角分辨率来决定。另外，第二模式发射的所述部分激光器可以是预先设置好的，也可以是实时生成的。例如对于图5中每个发光时刻的8个激光器，可从中随机选择 一个激光器来实施第二模式的发射，这些都在本发明的保护范围内。
图5和图6示出了对于所述k个激光器来说，第二模式的发射位于第一模式发射之后。可替换的，第二模式的发射也可以在第一模式发射之前进行，如图7所示的。在所述k个激光器按照第一模式发射之前，先按照第二模式进行发射，进行近处的目标物探测。此处不再赘述。
本发明的一个实施例中，当目标物与激光雷达的距离在5-200m时，为测远模式(即测距结果用于提供雷达测远的三维点云数据)，测远模式发射的激光器数量多，当目标物与激光雷达的距离在5m以内时，为测近模式(即测距结果用于提供雷达测近的三维点云数据)，测近模式发射的激光器数量少。本发明不限于上述具体数值，也可以根据具体情况修改调整，例如根据激光雷达的透镜参数获得的随距离变化光斑偏移和弥散程度和系统对探测器输出信号的识别能力来确定距离预设值。所述距离预设值的设定是作为激光雷达输出三维点云数据的参照，下文会详细说明。
根据本发明的一个优选实施例，为了区分第一模式发出的第一探测光束和第二模式发出的第二探测光束，第一探测光束和第二探测光束可以具有不同的脉冲编码。例如第一探测光束和第二探测光束都可以采用双脉冲，但二者的双脉冲具有不同的时间间隔从而进行编码，从而在接收端可以根据回波脉冲的间隔，区分该回波对应于第一探测光束还是第二探测光束。另外，第一探测光束和第二探测光束也可以通过各通道对应的探测器预留的不同时间窗口读取的信号来区分，例如对于第二模式在第一模式之后的情况，第一模式的第一探测光束用于测远则探测器(自该通道激光器按第一模式发光后)预留较长的第一时间窗口用于第一探测光束自目标物反射的回波接收，在第一模式完成测远后预留较短的第二时间窗口用于第二模式测近的第二探测光束的回波接收，因此通过各通道探测器第一时间窗口和第二时间窗口信号读取来区分第一探测光束和第二探测光束。
激光雷达通常具有转轴，可围绕转轴在一个平面内旋转。为方便起见，以激光雷达竖直安装的方位进行说明，即转轴沿着竖直方向，激光雷达可在水平面内旋转，并且在旋转过程中，驱动激光器发射出探测光束。激光雷达具有一定的角分辨率，例如0.1°或者0.2°，激光雷达的每个水平角位置处(例如以激光雷达的水平角分辨率为间隔)发射探测光束，图8示出了激光雷达的角分辨率为0.1°，即每隔0.1°，进行一次探测。根据本发明的一个优选实施例，所述第一模式包括：在所述激光雷达的每个水平角位置处，控制所述激光器阵列中所述n个的激光器发光；所述第二 模式包括：在与所述第一模式相同的所述水平角位置处，控制所述激光器阵列中的部分激光器发光。如图8(a)-(d)所示的，在激光雷达的每个水平角位置处，除了进行第一模式的发光探测以外，还通过所述k个激光器进行第二模式的发光探测。如图8中，128个激光器分为16组发光，每组激光器阵列(即子激光器阵列)包括8个激光器。在第一模式，控制每组激光器阵列中n个激光器发光，这里n的最大值即为每组激光器阵列(子激光器阵列)的激光器的总个数，例如，在第一模式控制该组8个激光器都进行发光，随后第二模式控制每组激光器阵列中只有少数发光，例如1个，按时间顺序，一组完成后再进行下一组操作。以图8(a)为例，第二模式的激光器编号分别为1-1、3-1、4-2、5-3、7-4、9-5、10-3、12-1(参照图5)，其中第二模式的激光器都选自不同的组，从而可进一步降低光串扰可能。本实施中128个激光器均匀分组，当然也可以根据实际情况非均匀分组，即每组激光器阵列中激光器的数量可以不同。
另外优选的，其中在所述激光雷达的两个相邻水平角位置处，发射所述第二探测光束的所述部分激光器互不相同，所述第二模式以所述激光雷达的s个水平角为周期循环，其中s为大于等于2的整数。如图8(a)所示，在0.0°度处所述部分激光器编号分别为1-1、3-1、4-2、5-3、7-4、9-5、10-3、12-1；如图8(b)所示，在0.1°处所述部分激光器编号分别为1-2、2-7、3-6、5-5、7-2、10-7、13-4、14-6，其中在0.0处和0.1°处以第二模式发光的部分激光器是不重合的，第二模式激光器的选择方法尽量确保尽可能充分地分批次利用128个激光器中不同位置的激光器，使近距探测的视场及分辨率得到充分保证。
以图8所示的128线的激光雷达为例，8个通道同时发光，一共发16次，水平分辨率0.1°。在正常进行测远的时候，在某些特定通道完成测远后追加一次测近，在每一次128个通道轮流发光测远中插入8次测近，每次测近都优选是单通道发光。在四个0.1°中，选取不同的8次测近通道，如此在0.4°的循环中，便完成了32个测近通道的收发。因此，该激光雷达的测远为128线，水平角分辨率0.1°，而测近为32线，水平角分辨率0.4°。在测远和测近时可以采用不同编码的脉冲，以区分测远和测近的回波信号，避免误识别。图8举例说明128线雷达的测近和测远发光序列排布，其中绿色块为测远发光时间窗，黄色块为测近发光时间窗。测近是安排在该通道完成测远之后，再发一次光进行测近。
可替换的，在每一次128个通道轮流发光测远中插入16次测近，每次测近都优 选是单通道发光，在2个0.1°中，选取不同的16次测近通道，如此在0.2°的循环中，便完成了32个测近通道的收发。因此，该激光雷达的测远为128线，水平角分辨率0.1°，而测近为32线，水平角分辨率0.2°。
第二模式可以不是32线，是更高或更低的线束，根据实际情况进行设定。
本领域技术人员理解，本发明中高线束激光器并非必然分组依序发光，也可以同时发光。例如在一种情况中，激光器阵列101包括128个激光器以第一模式例如128个激光器可以同时发射第一探测光束(通过适当的光电隔离，用于提供测远数据(对于测远光串扰影响相对较小)，并且以第二模式，例如选择多个激光器(例如垂直视场相对分离的8个，16个，小于128即可)发射第二探测光束，例如用于测近(提供测近数据)。这样的实施例同样在本发明的保护范围内。
基于上述分析，本发明的实施例提出将激光雷达的测远和测近独立交替进行的方案。在测远时，所有通道(或大部分通道)都打开，测量中远处目标物；在测近时，只采用打开部分通道，且降低水平扫描频率，使得每次同时发光只有很少的通道甚至单通道发光，这样就能极大地减少近距光串扰，甚至完全规避光串扰。这样的话，激光雷达在测中远距离时为高线束、高水平角分辨率，测近距时为低线束、低水平角分辨率。但这并不会显著降低近处目标物的分辨能力，因为近处目标物的探测和识别，本身所需要的线束和角分辨率就低，过高的线束和过高的水平角分辨率在近处甚至会形成光斑堆叠，产生冗余。
本发明的第二方面涉及一种激光雷达，如图9所示，下面参考附图描述。
如图9所示，激光雷达10包括如上所述的发射单元100、接收单元120、和处理单元130。其中所述发射单元100可以按照第一模式和第二模式向激光雷达10的外部交错地发射第一探测光束和第二探测光束L1/L2，其中第一模式下使用的激光器的数量多于第二模式下使用的激光器的数目，例如分别用于测远和测近。第一探测光束和第二探测光束在目标物OB上发生漫反射，雷达回波L1'/L2'返回到激光雷达,被接收单元120接收。所述接收单元200包括探测器阵列，例如APD、SiPM、SPAD等探测器的阵列，探测器阵列配置成可接收所述第一探测光束和第二探测光束被目标物反射后的回波，并将所述回波转换为电信号。处理单元130耦接到所述探测器阵列，配置成可读取所述探测器阵列输出的电信号，并判断所述电信号对应于第一探测光束或第二探测光束，并根据所述电信号计算目标物的距离，并根据所述距离和所述判断结果生成点云数据。
本领域技术人员容易理解，所述接收单元120和处理单元130可以配置为分离的模块，也可以集成为一个整体的模块，这些都在本发明的保护范围内。另外，为了获得飞行时间基于飞行时间测距法(TOF)计算目标物和激光雷达间的距离，所述处理单元130可以耦接到所述发射单元100，从而可以记录第一探测光束和第二探测光束的发射时间，当然通过其他方式获知发射时间也是可行的，此处不再赘述。
根据本发明的激光雷达，可以将高线束激光雷达的测远和测近独立交替进行，测远的时候采用最高的线束和角分辨率，而测近的时候采用较低的线束和角分辨率，使得测近时同时发光的通道数减少，从而减小近距的光串扰。
本发明的第三方面涉及一种使用如上所述的激光雷达10进行测距的方法200，如图10所示，下面参考附图描述。
在步骤S201：控制所述激光器阵列以第一模式发出第一探测光束，其中所述第一模式包括：控制所述激光器阵列中的n个激光器发光，n小于等于N，N为所述激光器阵列中激光器的总数；所述第一模式例如为测远模式，优选启用所述激光器阵列中所有的激光器依次发出第一探测光束。
在步骤S202：控制所述激光器阵列中的部分激光器在以所述第一模式发出第一探测光束之前或之后以第二模式发出第二探测光束。其中所述第二模式包括，控制所述激光器阵列中的k个激光器发光，其中所述k个激光器选自所述n个激光器，k小于n；所述第二模式例如为测近模式，例如可启用所述激光器阵列中部分激光器依次发射出第二探测光束。
优选的所述n等于所述激光器阵列中激光器的总数N，优选地第二模式为单通道发光,优选地所述n个激光器同时发光，所述k个激光器也同时发光。
在步骤S203：接收探测光束被目标物反射的回波并将所述回波转换为电信号，根据所述电信号计算目标物与激光雷达间的距离。例如可根据回波的接收时间以及探测光束的发射时间，基于飞行时间测距法(TOF，距离＝飞行时间*光速/2)，即可得到目标物与激光雷达间的距离。
在步骤S204：判断所述电信号对应于第一探测光束或第二探测光束。
在步骤S205：根据所述距离和所述判断结果生成点云数据。例如，当判断所述电信号对应于第一探测光束时(测远模式)，如果根据该电信号计算出的目标物与激光雷达间的距离小于距离预设值(例如5米)，由于该电信号是用于测远，此时可选择不使用或丢弃该电信号，不用于生成点云数据。反之，当判断所述电信号对应于 第二探测光束时(测近模式)，如果根据该电信号计算出的目标物与激光雷达间的距离大于距离预设值(例如5米)，由于该电信号用于测近，此时可选择不使用或丢弃该电信号，不用于生成点云数据。利用测远和测近模式的数据拼接生成更准确的三维点云数据。
根据本发明的一个实施例，所述步骤S202包括：控制所述激光器阵列中的所述k个激光器在以所述第一模式发出第一探测光束之后以第二模式发出第二探测光束，如图5和图6所示。或者可替换的，所述步骤S202包括：控制所述激光器阵列中的部分激光器在以所述第一模式发出第一探测光束之前以第二模式发出第二探测光束，如图7所示。
根据本发明的一个实施例，其中所述第一模式包括：在所述激光雷达的每个水平角位置处，控制所述激光器阵列中的所述n个激光器发光；所述第二模式包括：在与所述第一模式相同的所述水平角位置处，控制所述激光器阵列中的所述k个激光器发光。根据本发明的一个实施例，所述激光器阵列分为m组依序发光，m为整数且m>1，控制每组激光器阵列以第一模式发出第一探测光束，并控制所述每组激光器阵列在以所述第一模式发出第一探测光束之前或之后以第二模式发出第二探测光束。
根据本发明的一个实施例，在所述激光雷达的两个相邻水平角位置处，发射所述第二探测光束的所述部分激光器互不相同，所述第二模式以所述激光雷达的s个水平角为周期循环，其中s为大于等于2的整数。
根据本发明的一个实施例，所述第一探测光束和第二探测光束具有不同的脉冲编码，从而可根据不同的脉冲编码，在接收端可以区分出该雷达回波对应于第一探测光束或是第二探测光束，从而进行相应的处理操作。
根据本发明的一个实施例，所述步骤S204包括：通过接收所述回波的时间窗口，判断所述电信号对应于第一探测光束或第二探测光束。
为了区分第一探测光束和第二探测光束，第一探测光束和第二探测光束可以具有不同的脉冲编码。例如第一探测光束和第二探测光束都可以采用双脉冲，但二者的双脉冲具有不同的时间间隔从而进行编码，从而在接收端可以根据回波脉冲的间隔，区分该回波对应于第一探测光束还是第二探测光束。另外，第一探测光束和第二探测光束也可以通过各通道对应的探测器预留的不同时间窗口读取的信号来区分，例如对于第二模式在第一模式之后的情况，第一模式的第一探测光束用于测远 则探测器(自该通道激光器按第一模式发光后)预留较长的第一时间窗口用于第一探测光束自目标物反射的回波接收，在第一模式完成测远后预留较短的第二时间窗口用于第二模式测近的第二探测光束的回波接收，因此通过各通道探测器第一时间窗口和第二时间窗口信号读取来区分第一探测光束和第二探测光束。
基于上述分析，本发明提出将激光雷达的测远和测近独立交替进行的方案。在测远时，所有通道都打开，测量中远处目标物；在测近时，只采用打开部分通道，且降低水平扫描频率，使得每次同时发光只有很少的通道甚至单通道发光，这样就能极大地减少近距光串扰，甚至完全规避光串扰。这样的话，激光雷达在测中远距离时为高线束、高水平角分辨率，测近距时为低线束、低水平角分辨率。但这并不会显著降低近处目标物的分辨能力，因为近处目标物的探测和识别，本身所需要的线束和水平角分辨率就低，过高的线束和过高的角分辨率在近处甚至会形成光斑堆叠，产生冗余。
在测远时，所有通道都打开可以理解为在测远时所有激光器轮流发光，并在该测远距离范围内，所有通道的探测器对应的时间窗口获得的是有效数据。在测近时，打开部分通道可以理解为在测近时部分激光器轮流发光，在该测近距离范围内，部分通道的探测器对应的时间窗口获得的是有效数据。在测远和测近时可以采用不同的编码，以区分测远和测近的回波信号，避免误识别。
本发明将高线束激光雷达的测远和测近独立交替进行，测远的时候采用最高的线束和分辨率，而测近的时候采用较低的线束和分辨率，使得测近时同时发光的通道数减少，从而减小近距的光串扰。举例说明：高线束激光雷达的测远和测近独立交替进行，测远的时候采用最高的线束和分辨率，而测近的时候采用较低的线束和分辨率，使得测近时同时发光的通道数减少。
由以上事实可以推断出，激光雷达可以采用较多通道并行发光，提高远处目标的分辨率；同时，采用较少通道来测量近处目标物，并且测近时的同时发光通道尽可能少，减少同时发光通道之间的干扰，使得近处测量的精度大大提高。
最后应说明的是：以上所述仅为本发明的优选实施例而已，并不用于限制本发明，尽管参照前述实施例对本发明进行了详细的说明，对于本领域的技术人员来说，其依然可以对前述各实施例所记载的技术方案进行修改，或者对其中部分技术特征进行等同替换。凡在本发明的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本发明的保护范围之内。

Claims (15)

  1. 一种激光雷达的发射单元，包括：
    激光器阵列，配置成可发射出探测光束；
    发射控制器，所述发射控制器与所述激光器阵列耦接，配置成可控制所述激光器阵列以第一模式发出第一探测光束，并配置成可控制所述激光器阵列在以所述第一模式发出第一探测光束之前或之后以第二模式发出第二探测光束，
    其中所述第一模式包括：控制所述激光器阵列中的n个激光器发光，n小于等于N，N为所述激光器阵列中激光器的总数；所述第二模式包括，控制所述激光器阵列中的k个激光器发光，其中所述k个激光器选自所述n个激光器，k小于n。
  2. 如权利要求1中任一项所述的激光雷达的发射单元，其中所述第一模式为测远模式，所述第二模式为测近模式。
  3. 如权利要求1所述的激光雷达的发射单元，其中所述第一模式包括：在所述激光雷达的每个水平角位置处，控制所述激光器阵列中的所述n个激光器发光；所述第二模式包括：在与所述第一模式相同的所述水平角位置处，控制所述激光器阵列中的所述k个激光器发光。
  4. 如权利要求3所述的激光雷达的发射单元，所述发射控制器配置成将所述激光器阵列分为m组依序发光，m为整数且m>1，所述发射控制器配置成可控制每组激光器阵列以第一模式发出第一探测光束，并配置成可控制所述每组激光器阵列在以所述第一模式发出第一探测光束之前或之后以第二模式发出第二探测光束。
  5. 如权利要求1-3中任一项所述的激光雷达的发射单元，其中在所述激光雷达的两个相邻水平角位置处，发射所述第二探测光束的所述k个激光器互不相同，所述第二模式以所述激光雷达的s个水平角为周期循环，其中s为大于等于2的整数。
  6. 如权利要求1-4中任一项所述的激光雷达的发射单元，其中所述第一探测光束和第二探测光束具有不同的脉冲编码。
  7. 如权利要求1-4中任一项所述的激光雷达的发射单元，其中所述激光器阵列为由单个激光器或线阵激光器或面阵激光器形成的激光器阵列，所述激光器包括边发射型激光器或垂直腔面发射激光器。
  8. 一种激光雷达，包括：
    如权利要求1-7中任一项所述的发射单元；
    接收单元，所述接收单元包括探测器阵列，配置成可接收所述第一探测光束和第二探测光束被目标物反射的回波，并将所述回波转换为电信号；和
    处理单元，耦接到所述探测器阵列，配置成可读取所述探测器阵列输出 的电信号，根据所述电信号计算目标物与激光雷达间的距离，并判断所述电信号对应于第一探测光束或第二探测光束，并根据所述距离和所述判断结果生成点云数据。
  9. 一种使用如权利要求8所述的激光雷达进行测距的方法，包括：
    S201：控制所述激光器阵列以第一模式发出第一探测光束,其中所述第一模式包括：控制所述激光器阵列中的n个激光器发光，n小于等于N，N为所述激光器阵列中激光器的总数；
    S202：控制所述激光器阵列在以所述第一模式发出第一探测光束之前或之后以第二模式发出第二探测光束，其中所述第二模式包括，控制所述激光器阵列中的k个激光器发光，其中所述k个激光器选自所述n个激光器，k小于n；
    S203：接收探测光束被目标物反射的回波并将所述回波转换为电信号，根据所述电信号计算目标物与激光雷达间的距离；
    S204：判断所述电信号对应于第一探测光束或第二探测光束；和
    S205：根据所述距离和所述判断结果生成点云数据。
  10. 如权利要求9所述的方法，其中所述第一模式为测远模式，所述第二模式为测近模式。
  11. 如权利要求9所述的方法，其中所述第一模式包括：在所述激光雷达的每个水平角位置处，控制所述激光器阵列中的所述n个激光器发光；所述第二模式包括：在与所述第一模式相同的所述水平角位置处，控制所述激光器阵列中的所述k个激光器发光。
  12. 如权利要求11所述的方法，所述激光器阵列分为m组依序发光，m为整数且m>1，控制每组激光器阵列以第一模式发出第一探测光束，并控制所述每组激光器阵列在以所述第一模式发出第一探测光束之前或之后以第二模式发出第二探测光束。
  13. 如权利要求9-11中任一项所述的方法，其中在所述激光雷达的两个相邻水平角位置处，发射所述第二探测光束的所述k个激光器互不相同，所述第二模式以所述激光雷达的s个水平角为周期循环，其中s为大于等于2的整数。
  14. 如权利要求9-12中任一项所述的方法，其中所述第一探测光束和第二探测光束具有不同的脉冲编码。
  15. 如权利要求9-12中任一项所述的方法，其中所述步骤S204包括：通过接收所述回波的时间窗口，判断所述电信号对应于第一探测光束或第二探测光束。
PCT/CN2020/133185 2020-01-24 2020-12-01 激光雷达的发射单元、激光雷达以及测距方法 WO2021147520A1 (zh)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP20914833.7A EP3995851A4 (en) 2020-01-24 2020-12-01 TRANSMISSION UNIT OF A LASER RADAR, LASER RADAR AND DISTANCE MEASUREMENT METHOD
US17/563,263 US20220120867A1 (en) 2020-01-24 2021-12-28 Transmitting unit of laser radar, laser radar, and distance measurement method

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202010077216.3 2020-01-24
CN202010077216.3A CN113176555A (zh) 2020-01-24 2020-01-24 激光雷达的发射单元、激光雷达以及测距方法

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US17/563,263 Continuation US20220120867A1 (en) 2020-01-24 2021-12-28 Transmitting unit of laser radar, laser radar, and distance measurement method

Publications (1)

Publication Number Publication Date
WO2021147520A1 true WO2021147520A1 (zh) 2021-07-29

Family

ID=76921426

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2020/133185 WO2021147520A1 (zh) 2020-01-24 2020-12-01 激光雷达的发射单元、激光雷达以及测距方法

Country Status (4)

Country Link
US (1) US20220120867A1 (zh)
EP (1) EP3995851A4 (zh)
CN (1) CN113176555A (zh)
WO (1) WO2021147520A1 (zh)

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20240033051A (ko) * 2021-08-19 2024-03-12 헤사이 테크놀로지 씨오., 엘티디. 개별적으로 어드레스 가능하고 스캔 가능하며 통합 가능한 레이저 방출기를 갖는 라이다
CN115980778A (zh) * 2021-10-15 2023-04-18 华为技术有限公司 激光雷达、接收系统、发射系统以及控制方法
CN114325730B (zh) * 2021-11-17 2022-12-13 杭州宏景智驾科技有限公司 一种大视场远距离激光雷达测试方法
CN113933811B (zh) * 2021-11-22 2023-12-29 上海禾赛科技有限公司 激光雷达的探测方法、激光雷达以及计算机存储介质
CN116265983A (zh) * 2021-12-17 2023-06-20 上海禾赛科技有限公司 激光雷达的控制方法以及多通道激光雷达
CN114236561A (zh) * 2022-02-24 2022-03-25 探维科技(北京)有限公司 探测信号发射系统、激光雷达系统及探测方法
CN116794631A (zh) * 2022-03-14 2023-09-22 上海禾赛科技有限公司 激光雷达的控制方法、计算机存储介质以及激光雷达
WO2023245135A1 (en) * 2022-06-15 2023-12-21 nEYE Systems, Inc. Lidar with split and amplify architecture and integrated protection switches
CN117434539A (zh) * 2022-07-15 2024-01-23 深圳市速腾聚创科技有限公司 多通道激光发射的控制方法、装置和计算可读存储介质
CN115932798A (zh) * 2023-02-21 2023-04-07 探维科技(北京)有限公司 激光雷达收发器、激光雷达探测系统及探测方法

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5099266A (en) * 1989-12-28 1992-03-24 Seikosha Co., Ltd. Range meter for camera
WO1993000568A1 (en) * 1991-06-21 1993-01-07 Eastman Kodak Company Time-multiplexed multi-zone rangefinder
US20040164892A1 (en) * 2001-12-18 2004-08-26 Hitachi, Ltd. Monopulse radar system
CN104457689A (zh) * 2013-09-25 2015-03-25 北京航天计量测试技术研究所 一种用于近距离激光测距仪的光学接发结构
CN109884610A (zh) * 2019-03-14 2019-06-14 深圳市镭神智能系统有限公司 一种激光雷达扫描方法和激光雷达
CN110031845A (zh) * 2018-01-10 2019-07-19 株式会社万都 控制雷达的设备和方法
CN110412600A (zh) * 2018-04-27 2019-11-05 夏普株式会社 光雷达装置

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10203399B2 (en) * 2013-11-12 2019-02-12 Big Sky Financial Corporation Methods and apparatus for array based LiDAR systems with reduced interference
US10126411B2 (en) * 2015-03-13 2018-11-13 Continental Advanced Lidar Solutions Us, Llc. Beam steering LADAR sensor
US10684358B2 (en) * 2016-11-11 2020-06-16 Raytheon Company Situational awareness sensor using a fixed configuration of optical phased arrays (OPAs)
DE102017106380B4 (de) * 2017-03-24 2021-10-07 Sick Ag Optoelektronischer Sensor und Verfahren zum Erfassen von Objekten
EP3652555B1 (en) * 2017-08-31 2024-03-06 SZ DJI Technology Co., Ltd. A solid state light detection and ranging (lidar) system system and method for improving solid state light detection and ranging (lidar) resolution
CN108132464A (zh) * 2017-11-07 2018-06-08 北醒（北京）光子科技有限公司 一种固态面阵激光雷达探测方法
WO2019099166A1 (en) * 2017-11-15 2019-05-23 Veoneer Us, Inc. Scanning lidar system and method with spatial filtering for reduction of ambient light
CN114500808A (zh) * 2019-08-14 2022-05-13 Oppo广东移动通信有限公司 激光投射器、深度相机及电子装置

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5099266A (en) * 1989-12-28 1992-03-24 Seikosha Co., Ltd. Range meter for camera
WO1993000568A1 (en) * 1991-06-21 1993-01-07 Eastman Kodak Company Time-multiplexed multi-zone rangefinder
US20040164892A1 (en) * 2001-12-18 2004-08-26 Hitachi, Ltd. Monopulse radar system
CN104457689A (zh) * 2013-09-25 2015-03-25 北京航天计量测试技术研究所 一种用于近距离激光测距仪的光学接发结构
CN110031845A (zh) * 2018-01-10 2019-07-19 株式会社万都 控制雷达的设备和方法
CN110412600A (zh) * 2018-04-27 2019-11-05 夏普株式会社 光雷达装置
CN109884610A (zh) * 2019-03-14 2019-06-14 深圳市镭神智能系统有限公司 一种激光雷达扫描方法和激光雷达

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP3995851A4 *

Also Published As

Publication number Publication date
US20220120867A1 (en) 2022-04-21
CN113176555A (zh) 2021-07-27
EP3995851A4 (en) 2022-09-28
EP3995851A1 (en) 2022-05-11

Similar Documents

Publication Publication Date Title
WO2021147520A1 (zh) 激光雷达的发射单元、激光雷达以及测距方法
WO2018223821A1 (zh) 多线激光雷达
CN113433564B (zh) 激光雷达及使用激光雷达测距的方法
US20210278540A1 (en) Noise Filtering System and Method for Solid-State LiDAR
CN108132464A (zh) 一种固态面阵激光雷达探测方法
CN108107417A (zh) 一种固态面阵激光雷达装置
CN111007484B (zh) 一种单线激光雷达
WO2020216143A1 (zh) 激光雷达的接收装置、激光雷达及其回波处理方法
WO2021175227A1 (zh) 激光雷达及使用激光雷达测距的方法
WO2021175228A1 (zh) 激光雷达及其测距方法
WO2022105273A1 (zh) 激光雷达的控制方法及激光雷达
CN109814087A (zh) 激光收发模块及激光雷达系统
CN111308443B (zh) 一种激光雷达
CN114174869A (zh) 高分辨率固态lidar发射器
JP2022539706A (ja) 適応型多重パルスｌｉｄａｒシステム
CN115166760A (zh) 激光雷达及测距方法
CN113484869A (zh) 探测装置及方法
CN110118961A (zh) 光线发射模块和激光雷达
WO2023109042A1 (zh) 激光雷达的控制方法以及多通道激光雷达
CN111856429B (zh) 多线激光雷达及其控制方法
WO2020215577A1 (zh) 激光雷达及其探测装置
WO2022227638A1 (zh) 光探测装置及探测方法
CN111580069A (zh) 一种多线激光雷达系统及基于该系统的扫描方法
CN116299347A (zh) 激光雷达及其探测方法
CN209707678U (zh) 一种激光雷达装置

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 20914833

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2020914833

Country of ref document: EP

Effective date: 20220201

NENP Non-entry into the national phase

Ref country code: DE