WO2023173938A1 - 激光雷达的控制方法、计算机存储介质以及激光雷达 - Google Patents

激光雷达的控制方法、计算机存储介质以及激光雷达 Download PDF

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Publication number
WO2023173938A1
WO2023173938A1 PCT/CN2023/073370 CN2023073370W WO2023173938A1 WO 2023173938 A1 WO2023173938 A1 WO 2023173938A1 CN 2023073370 W CN2023073370 W CN 2023073370W WO 2023173938 A1 WO2023173938 A1 WO 2023173938A1
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Prior art keywords
group
detection
channels
channel
pulses
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PCT/CN2023/073370
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English (en)
French (fr)
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时从波
向少卿
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上海禾赛科技有限公司
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Publication of WO2023173938A1 publication Critical patent/WO2023173938A1/zh

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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
    • 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
    • G01S17/88—Lidar systems specially adapted for specific applications
    • G01S17/93—Lidar systems specially adapted for specific applications for anti-collision purposes
    • 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
    • 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
    • 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
    • G01S7/495—Counter-measures or counter-counter-measures using electronic or electro-optical means

Definitions

  • the present disclosure relates to the field of photoelectric detection technology, and in particular, to a control method of a laser radar, a computer storage medium and a laser radar.
  • Lidar as a three-dimensional measurement system, achieves three-dimensional measurement coverage of the measurement area through collected point clouds.
  • Multi-channel lidar based on Time of Flight (ToF) can use multiple transmitting and receiving channels, which is suitable for situations that require scanning a large field of view and acquiring high-density point clouds.
  • ToF Time of Flight
  • the 128 lasers are arranged in 32 rows and 4 columns.
  • Laser 11 represents the laser located in column 1 and row 1
  • laser 12 represents the laser located in column 1 and row 2
  • laser 41 represents the laser located in row 4.
  • the number of parallel light-emitting channels of a certain lidar is 8.
  • select lasers 11 and 13. 22, 24, 33, 34, 44, and 42 are used as a group of lasers to emit light in parallel and detect in parallel.
  • the channels of parallel detection are channel1-channel8, and 8 points with a range upper limit of 200m can be generated in 1.333us. .
  • the 128 lasers are divided into 16 groups, and each group emits light and detects in parallel. In this way, compared to a lidar with only one laser emitting light at the same time, the resolution of the point cloud is increased to eight times.
  • Figure 2a shows a schematic diagram of the vertical field of view of the lidar.
  • the figure is a cross-sectional view of the lidar in the vertical direction.
  • the vertical field of view is the angle range that the lidar can detect in the vertical direction.
  • Multiple lasers arranged vertically emit The detection beams correspond to line beam 1, line beam 2,..., line beam 40 respectively, and the vertical field of view is 23° (from -16° downward to 7° upward).
  • the angle between two adjacent points on a vertical plane parallel to the rotation axis is the vertical angular resolution.
  • the detection beam will be concentrated to the area of interest in the middle. Therefore, the detection beam is not evenly distributed vertically, but dense in the middle and sparse on both sides.
  • Figure 2b shows a schematic diagram of the horizontal field of view of the lidar.
  • the figure shows the angle of the lidar in the horizontal direction.
  • Cross-sectional view the horizontal field of view is the angular range that the lidar can detect in the horizontal direction. For example, if a mechanical lidar rotates 360°, the horizontal field of view is 360°.
  • the angle between two adjacent points on the horizontal plane perpendicular to the rotation axis is the horizontal angular resolution.
  • the horizontal angular resolution is 0.2°.
  • Multi-channel parallel luminescence measurements introduce issues of optical and electrical crosstalk.
  • Optical crosstalk is the interference caused by adjacent laser radar channels emitting light in parallel.
  • the detector in each channel will receive the reflected light from the detection pulse emitted by other channels on the target object.
  • the intensity of reflected light increases as the distance decreases. The higher the reflectivity of the target, the higher the intensity of reflected light.
  • an interfering pulse waveform will be generated on the waveform received by the detector of this channel (which will be superimposed with the echo pulse caused by the real obstacle, and the real echo pulse is the subsequent
  • the above-mentioned optical crosstalk is the main factor affecting the accuracy of ranging, and it often occurs in scenes with high reflectivity at close range.
  • Electrical crosstalk means that when multiple laser radar channels receive electrical signals at the same time, the signal from the channel with stronger electrical signals will directly crosstalk to the remaining receiving channels through the circuit, resulting in an interfering pulse waveform.
  • the present invention relates to a control method of lidar.
  • the lidar includes a plurality of channels, each channel includes at least one laser and at least one detector, and the control method Laws include:
  • S11 The plurality of channels are divided into multiple groups, and each group of channels emits light in parallel. For one group of channels, the emission timing of the laser of the group of channels is determined, where the first emission timing used in the first detection orientation and the first emission timing in the first detection direction are determined. The second lighting timing used in the two detection directions is different;
  • S12 In the first detection orientation, control the laser of the group of channels to emit the first group of detection pulses according to the first lighting timing sequence;
  • S13 The detectors passing through the set of channels respectively receive the first set of echo pulses reflected from the object by the first set of detection pulses;
  • S15 The detectors passing through the set of channels respectively receive the second set of echo pulses reflected from the object by the second set of detection pulses;
  • S16 For one channel in the group of channels, determine the effective echo pulse of the one channel based on the stable first set of echo pulses and the second set of echo pulses of the one channel.
  • the lasers of the group of channels do not emit light at the same time.
  • the echo pulses received by the detector of each channel in the group of channels include effective echo pulses and crosstalk generated by other channels
  • the step S16 includes : According to the time matching degree, determine the echo pulse that coincides with the first detection direction and the second detection direction of the one channel.
  • steps S12 and S14 at least one pulse among the pulses emitted by the laser of the group of channels is used as a ranging pulse
  • the step S16 includes: for one channel in the group of channels, relatively Translate the emission time of the ranging pulses of one channel in the first detection azimuth and the second detection azimuth until they overlap, compare the two ranging results, and select an echo pulse with a stable position.
  • the detectors passing through the group of channels respectively receive the ranging echo pulses reflected from the object by the ranging pulses
  • the step S16 includes: for the group a channel within a channel, relative translation of said one channel in said first detection
  • the emission times of the ranging pulses of the azimuth and the second detection azimuth must coincide with each other, and the ranging echo pulses that are staggered from each other in time are echo pulses with stable positions.
  • step S11 further includes: determining the lighting timing sequence of the laser of the group of channels in at least one other detection orientation after the second detection orientation, wherein the lighting in at least one other detection orientation The timing is different from the first lighting timing and the second lighting timing.
  • the step S16 includes: for a channel in the group of channels, determining whether the one channel is in the first detection orientation, the second detection orientation and at least one The echo pulses with stable positions in other detection directions are used as the effective echo pulses of the one channel in the first detection direction and/or the second detection direction.
  • the time difference between the first detection position, the second detection position and the at least one other detection position is within a preset time range.
  • step S16 further includes: determining the position of the one channel at the first detection position and the second detection position according to the echo pulse of at least one second channel at the first detection position and the second detection position. Echo pulses with stable positions in the first and second detection directions.
  • step S16 includes: when the one channel is in the first detection orientation and the second detection orientation, the difference or ratio of the amplitudes of the echo pulses with stable positions exceeds a predetermined value.
  • the threshold is set, the stable echo pulse is regarded as the effective echo pulse of the one channel in the first detection orientation and/or the second detection orientation.
  • step S11 includes:
  • the first lighting timing and the second lighting timing are determined in the following manner: based on one of the previous ranging results of each channel in the group of channels, the previous ranging results of the channels adjacent to the channel, and obstacle information, or Multiple items, determining the first lighting timing and the second lighting timing, the first lighting timing and the second lighting timing being configured such that the first set of echo pulses and the second set of echo pulses are staggered from each other in time.
  • control method further includes: dividing the total flight time window of the laser of the group of channels into at least a first interval and a second interval, wherein the first light emission timing is configured such that: A group of echo pulses are distributed in the second interval without overlapping, and the second lighting timing is configured such that: the second group of echo pulses and the first group of echo pulses are distributed in the second interval without overlapping. within the second interval.
  • the control method further includes: dividing the second interval into k sub-intervals, where k is an integer and greater than or equal to the number of channels in the group, wherein the first lighting timing configuration Such that: the first group of echo pulses are distributed in the k sub-intervals without overlapping; the second lighting timing is configured such that: the second group of echo pulses and the first group of echo pulses are distributed within the k sub-intervals without overlapping. within the k sub-intervals.
  • the length of each sub-interval is greater than the maximum pulse width of the echo pulse.
  • the first lighting timing is configured such that: the first group of echo pulses are distributed in the unoccupied and closest sub-intervals of the k sub-intervals;
  • the two lighting timings are configured such that the second group of echo pulses are distributed in the unoccupied and closest sub-intervals among the k sub-intervals.
  • the invention also relates to a computer storage medium comprising computer-executable instructions stored thereon, which when executed by a processor implement the control method according to any one of claims 1-14.
  • the invention also relates to a laser radar, including:
  • At least one of the pulses emitted by each laser is used as a ranging pulse
  • a plurality of detectors the plurality of lasers and the plurality of detectors forming a plurality of channels, each channel including at least one laser and at least one detector;
  • control device is connected to the plurality of lasers and the plurality of detectors, and the control device is configured to:
  • the plurality of channels are divided into multiple groups, and each group of channels emits light in parallel.
  • the light-emitting timing of the laser of the group of channels is determined, where the first light-emitting timing used in the first detection orientation and the second detection direction are used.
  • the second lighting timing used in the azimuth is different;
  • the laser that controls the group of channels emits a first group of detection pulses according to the first light-emitting timing sequence
  • the detectors passing through the set of channels respectively receive the first set of echo pulses reflected from the object by the first set of detection pulses;
  • the laser controlling the group of channels emits a second group of detection pulses according to the second light emission timing sequence
  • the detectors passing through the set of channels respectively receive the second set of echo pulses reflected from the object by the second set of detection pulses;
  • the effective echo pulse of the one channel is determined based on the first group of echo pulses and the second group of echo pulses of the one channel.
  • the lasers of the group of channels do not emit light at the same time.
  • the control device is configured to: according to the time matching degree, Determine the echo pulses of the one channel that coincide with the first detection orientation and the second detection orientation.
  • At least one pulse among the pulses emitted by the laser of the group of channels is used as a ranging pulse
  • the control device is configured to: for a channel in the group of channels, relatively translate the one channel within The emission times of the ranging pulses of the first detection azimuth and the second detection azimuth are until they coincide, and the two ranging results are compared to select an echo pulse with a stable position.
  • the detectors passing through the group of channels respectively receive the ranging echo pulses reflected from the object by the ranging pulses
  • the control device is configured to: for one channel in the group of channels, The emission times of the ranging pulses of one channel in the first detection orientation and the second detection orientation are relatively translated to coincide with each other, and the ranging echo pulses that are staggered from each other in time are echo pulses with stable positions.
  • the control device is configured to: determine the lighting timing sequence of the laser of the group of channels in at least one other detection orientation after the second detection orientation, wherein the lighting in at least one other detection orientation The timing is different from the first lighting timing and the second lighting timing, and the control device is further configured to: for one channel in the group of channels, determine the position of the one channel in the first detection orientation, the second detection orientation and Echo pulses with stable positions in at least one other detection orientation are used as effective echo pulses of the one channel in the first detection orientation and/or the second detection orientation.
  • the time difference between the first detection position, the second detection position and the at least one other detection position is within a preset time range.
  • control device is further configured to: determine whether the one channel is in the first detection position and the second detection position based on the echo pulse of at least one second channel in the first detection position and the second detection position. Echo pulses with stable positions in the first and second detection directions.
  • control device is further configured to: the difference or ratio of the amplitudes of the echo pulses with stable positions when the one channel is in the first detection orientation and the second detection orientation.
  • the stable echo pulse is used as the effective echo pulse of the one channel in the first detection orientation and/or the second detection orientation.
  • control device is further configured to determine the first lighting timing and the second lighting timing in the following manner: based on the previous ranging results of each channel in the group of channels, and the One or more of the ranging results before the channel adjacent to the channel and the obstacle information determine the first lighting timing and the second lighting timing, and the first lighting timing and the second lighting timing are configured such that: One set of echo pulses and a second set of echo pulses are offset in time from each other.
  • control device is further configured to: divide the total flight time window of the laser of the group of channels into at least a first interval and a second interval, wherein the first light emission timing is configured such that : The first group of echo pulses are distributed in the second interval without overlapping, and the second lighting timing is configured such that: the second group of echo pulses and the first group of echo pulses are distributed in the second interval without overlapping. within the second interval.
  • control device is further configured to: divide the second interval into k sub-intervals, where k is an integer and greater than or equal to the number of channels in the group, wherein the first light emitting
  • the timing is configured such that: the first group of echo pulses are distributed in the k sub-intervals without overlapping; the second lighting timing is configured such that: the second group of echo pulses do not overlap with the first group of echo pulses are distributed within the k sub-intervals.
  • the length of each sub-interval is greater than the maximum pulse width of the echo pulse.
  • control device is further configured to: the first lighting timing is configured such that: the first group of echo pulse distributions are not occupied in the k sub-intervals. and within the nearest sub-interval; the second lighting timing is configured such that: the second group of echo pulses are distributed in the unoccupied and nearest sub-interval among the k sub-intervals.
  • the first light-emitting timing used by the lidar in the first detection direction is different from the second light-emitting time sequence used in the second detection direction, so that the crosstalk becomes random and it is easy to select the real echo pulse with stable position. , thereby improving detection accuracy and reducing noise.
  • Figure 1 shows a schematic diagram of the arrangement of lasers in an existing multi-channel lidar
  • Figure 2a shows a schematic diagram of the lidar vertical field of view
  • Figure 2b shows a schematic diagram of the lidar horizontal field of view
  • Figure 3a shows a flow chart of a laser radar control method according to an embodiment of the present invention
  • Figure 3b shows a schematic diagram of the laser radar structure and detection according to one embodiment of the present invention
  • Figure 4 shows a comparison diagram of the lighting timing of the first detection direction and the second detection direction according to an embodiment of the present invention
  • Figure 5a shows a schematic diagram of transmitting and receiving in the first detection direction and the second detection direction according to an embodiment of the present invention
  • Figure 5b shows a schematic diagram of sliding window processing for channel 1 in Figure 5a;
  • Figure 5c shows a schematic diagram of the detection and sliding window modes of the two detection directions in Figure 5a;
  • Figure 6a shows a schematic diagram of the first sliding window range according to an embodiment of the present invention
  • Figure 6b shows a schematic diagram of the second sliding window range according to an embodiment of the present invention
  • Figure 6c shows a schematic diagram of the third sliding window range according to an embodiment of the present invention.
  • Figure 6d shows a fourth sliding window range schematic diagram according to an embodiment of the present invention.
  • Figure 7 shows a comparison chart of the ranging results of the first detection direction and the second detection direction according to an embodiment of the present invention
  • Figure 8 shows a schematic diagram of three pulse luminescence encoding settings
  • Figure 9 shows a schematic diagram of transmission and reception of 2 channels transmitting 3 pulses in parallel when there is no crosstalk
  • Figure 10 shows a schematic diagram of crosstalk between two channels
  • Figure 11a shows a schematic diagram of a multi-pulse time interval
  • Figure 11b shows a schematic diagram of the total flight time window when transmitting a double pulse
  • Figure 12a shows a schematic diagram of total flight time window division according to an embodiment of the present invention
  • Figure 12b shows a schematic diagram of total flight time window division according to another embodiment of the present invention.
  • Figure 13 shows a schematic diagram of the first lighting timing sequence and ranging results at ⁇ i angle according to one embodiment of the present invention
  • Figure 14 shows a schematic diagram of a lidar according to an embodiment of the present invention.
  • first and second are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, features defined as “first” and “second” may explicitly or implicitly include one or more of the described features. In the description of the present invention, “plurality” means two or more than two, unless otherwise clearly and specifically limited.
  • connection should be understood in a broad sense.
  • it can be a fixed connection or a removable connection.
  • Detachable connection, or integral connection it can be mechanical connection, electrical connection or mutual communication; it can be directly connected, or it can be indirectly connected through an intermediate medium, it can be internal connection of two elements or mutual communication between two elements. functional relationship.
  • a first feature “on” or “below” a second feature may include the first and second features being in direct contact, or may include the first and second features. Not in direct contact but through additional characteristic contact between them.
  • the terms “above”, “above” and “above” the first feature “above” the second feature include the first feature being directly above and diagonally above the second feature, or simply means that the first feature is higher in level than the second feature.
  • “Below”, “below” and “beneath” the first feature of the second feature includes the first feature being directly above and diagonally above the second feature, or simply means that the first feature is less horizontally than the second feature.
  • the inventor of this application conceived the idea of making the crosstalk random by adjusting the relative timing of the parallel light-emitting channels within a certain time range, and then selecting the echo pulses with stable positions in the two detection directions through pulse filtering. As a true echo signal reflected by an object in the direction of detection.
  • FIG. 3a shows a flow chart of a control method for a lidar according to an embodiment of the present invention. It can also be combined with reference to the lidar 20 shown in Figure 3b.
  • the lidar 20 includes a plurality of channels, and each channel includes at least one laser 21 and at least A detector 22, the control method 10 includes steps S10-S16, specifically as follows:
  • step S10 divide multiple channels into multiple groups, and each group of channels emits light in parallel.
  • the "parallel development "Light” refers to multiple channels completing signal transmission and receiving echoes within a time window. The lighting time of these channels can overlap with each other, but they do not necessarily need to emit or receive light at the same time.
  • a detection is carried out at a distance between 1 and 2. The laser can emit light at t1 and return after encountering the obstacle at the farthest dmax that the radar can detect. The echo is received by the detector at t2, and the time window ⁇ dmax/ 2C (C is the speed of light) ⁇ t2-t1.
  • step S11 for one group of channels, determine the lighting timing of the laser 21 of the group of channels, wherein the first lighting timing used in the first detection orientation and the second lighting timing used in the second detection orientation are different.
  • the light emission timing refers to the relative light emission time sequence of the multiple lasers 21 in a group of channels, that is, the time sequence in which light emission starts.
  • the lasers 21 of the group of channels do not emit light at the same time.
  • Figure 4 shows a comparison diagram of the lighting timing of the first detection orientation and the second detection orientation according to an embodiment of the present invention.
  • the group of channels includes channel 1, channel 2, channel 3 and channel 4, and each channel includes a laser 21.
  • the first light-emitting timing sequence in the first detection orientation is: first, the laser 21 of channel 1 and the laser 21 of channel 3 emit light at the same time, then the laser 21 of channel 2 emits light, and finally the laser 21 of channel 4 emits light;
  • the second light emitting timing is: the laser 21 of channel 2 emits light first, then the laser 21 of channel 1 and the laser 21 of channel 4 emit light at the same time, and finally the laser 21 of channel 3 emits light.
  • the interval between the first detection orientation and the second detection orientation is the vertical angular resolution or horizontal angular resolution of the lidar 20 .
  • the first lighting timing used in the first detection direction is different from the second lighting timing used in the second detection direction, so that the crosstalk becomes random and the real echo pulses are easily picked out.
  • step S12 in the first detection orientation, the laser 21 that controls the group of channels emits the first group of detection pulses according to the first lighting timing sequence.
  • the laser 21 of the group of channels emits At least one of the pulses serves as a ranging pulse.
  • FIG. 5a shows a schematic diagram of transmitting and receiving in the first detection orientation and the second detection orientation according to an embodiment of the present invention.
  • the group of channels includes channel 1, channel 2, channel 3 and channel 4.
  • Each channel includes a laser 21.
  • the first lighting sequence of a detection direction is: first, the laser 21 of channel 1 emits a ranging pulse A, then the laser 21 of channel 2 emits a ranging pulse B, then the laser 21 of channel 3 emits a ranging pulse C, and finally the laser 21 of channel 4 emits a ranging pulse.
  • Laser 21 emits ranging pulses D.
  • the lasers 21 of channels 1-4 can emit a single pulse or multiple pulses, and at least one pulse among the pulses emitted by each laser 21 is used as a ranging pulse.
  • FIG. 5a an example is introduced in which each channel includes one ranging pulse in the first detection orientation. For clear display, only the ranging pulses of each channel are shown in FIG. 5a .
  • step S13 the detectors 22 passing through the group of channels respectively receive the first group of echo pulses reflected from the object by the first group of detection pulses.
  • the echo pulses received by the detector 22 of each channel in the group of channels include effective echo pulses and crosstalk generated by other channels.
  • the detector 22 of the group of channels respectively receives the ranging echo pulse reflected from the object by the ranging pulse.
  • each channel includes a detector 22.
  • the detector 22 of channel 1 receives the ranging echo pulse A' after the ranging pulse A is reflected by the target object, and the detection of channel 2
  • the detector 22 receives the ranging echo pulse B' after the ranging pulse B is reflected by the target object.
  • the detector 22 of channel 3 receives the ranging echo pulse C' after the ranging pulse C is reflected by the target object.
  • Channel 4 The detector 22 receives the ranging echo pulse D' after the ranging pulse D is reflected by the target object.
  • channel 1 also receives the crosstalk corresponding to the ranging echo pulse B’, the crosstalk corresponding to the ranging echo pulse C’, and the crosstalk corresponding to the ranging echo pulse D’.
  • the crosstalk and ranging echo pulses are given the same reference numerals, and the crosstalk of other channels is not shown in Figure 5a.
  • step S14 in the second detection orientation, the laser 21 that controls the group of channels emits a second group of detection pulses according to a second light-emitting timing.
  • the light-emitting timing may refer to the time point when light emission starts.
  • step S14 at least one pulse among the pulses emitted by the laser 21 of the group of channels is used as a ranging pulse.
  • the second lighting sequence in the second detection orientation is: first, the laser 21 of channel 4 emits a ranging pulse D, then the laser 21 of channel 3 emits a ranging pulse C, and then the laser 21 of channel 2 emits a ranging pulse. Pulse B, the laser 21 of channel 1 finally emits ranging pulse A.
  • FIG. 5a an example is introduced in which each channel includes a ranging pulse in the second detection orientation. For clear display, only the ranging pulses of each channel are shown in FIG. 5a .
  • step S15 the detectors 22 passing through the set of channels respectively receive the second set of echo pulses reflected from the object by the second set of detection pulses.
  • the echo pulses received by the detector 22 of each channel in the group of channels include effective echo pulses and crosstalk generated by other channels.
  • the detector 22 of the group of channels respectively receives the ranging echo pulse reflected from the object by the ranging pulse.
  • the detector 22 of channel 1 receives the ranging echo pulse A' after the ranging pulse A is reflected by the target object, and the detector 22 of the channel 2 receives the ranging pulse B and is reflected by the target.
  • the ranging echo pulse B' reflected by the target object.
  • the detector 22 of channel 3 receives the ranging pulse C.
  • the ranging echo pulse C' reflected by the target object.
  • the detector 22 of channel 4 receives the ranging pulse.
  • the ranging echo pulse D' after D is reflected by the target object.
  • channel 1 also receives the crosstalk corresponding to the ranging echo pulse B’, the crosstalk corresponding to the ranging echo pulse C’, and the crosstalk corresponding to the ranging echo pulse D’.
  • the crosstalk and ranging echo pulses are given the same reference numerals, and the crosstalk of other channels is not shown in Figure 5a.
  • step S16 for one channel in the group of channels, determine the effective echo pulse of one channel based on a group of echo pulses and a second group of echo pulses of the one channel.
  • Determining the effective echo pulse of a channel can be achieved by determining the echo pulse whose position is stable when a channel is in the first detection azimuth and the second detection azimuth.
  • the so-called stable position means that a certain echo pulse is in the first echo pulse.
  • the relative deviation between the position in the second echo pulse and the second echo pulse is extremely small, basically fixed and stable, and there is no fluctuation or deviation exceeding a certain preset threshold, so it can be used as a channel in the first detection direction and/or The effective echo pulse of the second detection direction. This is because the first lighting timing used in the first detection direction is different from the second lighting timing used in the second detection direction.
  • the position where the crosstalk signal appears will become random, and the real echo will appear in the first echo pulse. and the first The two echo pulses can appear at basically the same position. Therefore, in this way, the echo with a stable position is selected as the real echo pulse. Based on the real echo, the distance information of the actual obstacle can be obtained. .
  • channels 1, 2, 3, and 4 emit light in parallel, there is still a certain relative timing between them, that is, in the first detection direction, the light-emitting moments of channels 1, 2, 3, and 4 are sequential. Decreasingly later; in the second detection orientation, channels 1, 2, 3, and 4 are still parallel emitting channels, but the relative timing between each other is different from that in the first detection orientation, that is, in the second detection orientation , channels 1, 2, 3, and 4 sequentially light up earlier in sequence.
  • step S16 includes: determining, according to the time matching degree, the echo pulse whose position coincides with that of the one channel at the first detection orientation and the second detection orientation.
  • the logic behind this application is: by adjusting the relative lighting timing of the parallel light-emitting channels in the two horizontal detection directions, the crosstalk signal (from other parallel light-emitting channels) appears in the echo received by the channel under test.
  • step S16 includes: for one channel in the group of channels, relatively translating the emission time of the ranging pulses of the one channel in the first detection azimuth and the second detection azimuth until they coincide, with a ratio of For the two ranging results, select the echo pulse with stable position. That , a sliding window operation is performed on the echo of a channel, that is, the ranging pulses of the channel in the first detection azimuth and the second detection azimuth are relatively translated so that their emission times coincide.
  • the following paragraphs will cooperate with the embodiment to perform the sliding window operation and The sliding window range is introduced.
  • Figure 5b shows a schematic diagram of sliding window processing for channel 1 in Figure 5a.
  • Figure 5c shows a schematic diagram of the detection and sliding window method of the two detection directions in Figure 5a.
  • the ranging echo pulse A' measured in the first detection azimuth and the second detection azimuth is compared, and the ranging is The position of the echo pulse A' is determined, and the leading edge does not coincide with the crosstalk pulses B', C', and D', and can be used as an effective echo pulse for the first detection direction and/or the second detection direction.
  • step S16 includes: One channel is relatively translated so that the emission times of the ranging pulses in the first detection azimuth and the second detection azimuth of the one channel coincide with each other, and the ranging echo pulses that are staggered from each other in time are echo pulses with stable positions.
  • the ranging echo pulse A' in the first detection azimuth and the second detection azimuth, is exactly one pulse width away from the other crosstalk B', crosstalk C' and crosstalk D' received by channel 1. This is a A relatively ideal situation.
  • the lighting timing can be adjusted so that the ranging echo pulse A' does not overlap with the crosstalk B', crosstalk C' and crosstalk D' as much as possible. In this way, the position of the ranging echo pulse A' is stable and can be used as Effective echo pulse in the first detection direction.
  • step S11 also includes: determining the lighting timing of the laser 21 of the group of channels in at least one other detection orientation after the second detection orientation, Wherein the light-emitting timing in at least one other detection orientation is different from the first light-emitting timing and the second light-emitting timing, step S16 includes: for a channel in the group of channels, for a channel in the first detection orientation, the second detection orientation and at least an other detection party
  • the echo signal of the position is subjected to sliding window processing as shown in Figure 5a-5c, and the echo pulse with stable position is determined as the effective echo pulse of the one channel in the first detection azimuth and/or the second detection azimuth.
  • the principle is that if different lighting timings are set for multiple detection directions, even if there is a superposition of ranging echo pulses and crosstalk, after sliding window processing is performed on the echo signals from as many different detection directions as possible, in some detection directions, There will always be a certain deviation between the crosstalk signal and the real echo, so that the real echo signal can eventually be found.
  • the time difference between the first detection position, the second detection position and at least one other detection position is within a preset time range.
  • the ranging results in two detection directions the ranging results in at least one other detection direction.
  • the preset time range is related to the speed of the radar. The faster the speed of the radar, the wider the time range can be set, the stronger the anti-interference effect, and the easier it is to pick out the real ranging echo pulses.
  • the preset time range is set to a multiple of the time interval corresponding to the horizontal angular resolution.
  • Performing sliding window processing in multiple detection orientations includes: for a channel, relatively translating the emission time of ranging pulses of the channel in the first detection orientation, the second detection orientation and at least one other detection orientation until they coincide.
  • the sliding window range is introduced below through examples.
  • Figure 6a shows a schematic diagram of the first sliding window range according to an embodiment of the present invention, in which the first detection azimuth corresponds to the horizontal field of view angle ⁇ i , the second detection azimuth corresponds to the horizontal field of view angle ⁇ i+1 , and the third detection azimuth corresponds to the horizontal field of view angle ⁇ i+1 Corresponding to the horizontal field of view angle ⁇ i+2 , for example, for a group of channels, obtain the ranging of the group of channels at the horizontal field of view angle ⁇ i , the horizontal field of view angle ⁇ i+1 and the horizontal field of view angle ⁇ i+2.
  • the echo pulse with stable position is selected.
  • the time difference between the horizontal field of view angle ⁇ i , the horizontal field of view angle ⁇ i+1 and the horizontal field of view angle ⁇ i+2 is at the preset time. within the time frame.
  • Figure 6b shows a schematic diagram of the second sliding window range according to an embodiment of the present invention, in which the first detection direction corresponds to the horizontal field of view angle ⁇ i , the second detection direction corresponds to the horizontal field of view angle ⁇ i+1 , and the third detection direction corresponds to the horizontal field of view angle ⁇ i+1 Corresponding to the horizontal field of view angle ⁇ i+2 , the fourth detection direction corresponds to the horizontal field of view angle ⁇ i+3 , and the fifth detection direction corresponds to the horizontal field of view angle ⁇ i+4 .
  • the horizontal field of view angle ⁇ i For a group of channels, obtain the horizontal field of view angle ⁇ i , horizontal field of view angle ⁇ i+1 , horizontal field of view angle ⁇ i+2 , horizontal field of view angle ⁇ i+3 and horizontal field of view respectively.
  • the ranging result of the angle ⁇ i+4 for one of the channels, the relative translation of the channel is at the horizontal field of view angle ⁇ i , the horizontal field of view angle ⁇ i+1 , the horizontal field of view angle ⁇ i+2 , the horizontal field of view angle ⁇
  • the emission times of ranging pulses at i+3 and horizontal field of view angle ⁇ i+4 coincide with each other, and the five ranging results are compared to select the echo pulse with a stable position.
  • the time difference between the horizontal field of view angle ⁇ i , the horizontal field of view angle ⁇ i+1 , the horizontal field of view angle ⁇ i+2 , the horizontal field of view angle ⁇ i+3 and the horizontal field of view angle ⁇ i+4 is within the preset time within the range.
  • step S16 further includes: based on the echo pulses of at least one second channel at the first detection azimuth and the second detection azimuth, determining whether the one channel is in the first detection azimuth and the second detection azimuth. Echo pulses with stable position when detecting the azimuth.
  • the interference in a group of channels and the interference of at least one second channel in the group of channels become random, and then through sliding window and pulse filtering, the interference is picked out Positionally stable, true ranging echo pulses.
  • Figure 6c shows a schematic diagram of the third sliding window range according to an embodiment of the present invention, in which the first detection azimuth corresponds to the horizontal field of view angle ⁇ i , the second detection azimuth corresponds to the horizontal field of view angle ⁇ i+1 , and the third detection azimuth corresponds to the horizontal field of view angle ⁇ i+1 Corresponding to the horizontal field of view angle ⁇ i+2 , it includes two second channels, namely CH-1 and CH-2. CH-1 corresponds to the previous vertical channel, and the second channel CH-2 corresponds to the next vertical channel.
  • the vertical channels include adjacent channels in the vertical direction that have been measured or relatively upper channels (refer to Figure 2a).
  • the ranging results of the group of channels at the horizontal field of view angle ⁇ i , the horizontal field of view angle ⁇ i+1 and the horizontal field of view angle ⁇ i+2 , as well as the previous vertical field of view of the group of channels.
  • the ranging pulse is emitted at angle ⁇ i+2 to coincide with each other, compare the above ranging results, and select the ranging echo pulse with stable position.
  • the time difference between the horizontal field of view angle ⁇ i , the horizontal field of view angle ⁇ i+1 and the horizontal field of view angle ⁇ i+2 is within a preset time range.
  • Figure 6d shows a schematic diagram of the fourth sliding window range according to an embodiment of the present invention, in which the first detection azimuth corresponds to the horizontal field of view angle ⁇ i , the second detection azimuth corresponds to the horizontal field of view angle ⁇ i+1 , and the third detection azimuth corresponds to the horizontal field of view angle ⁇ i+1 Corresponding to the horizontal field of view angle ⁇ i+2 , the second channel CH-1 corresponds to the previous vertical channel, and the second channel CH-2 corresponds to the next vertical channel.
  • the ranging results of the group of channels at the horizontal field of view angle ⁇ i , the horizontal field of view angle ⁇ i+1 and the horizontal field of view angle ⁇ i+2 , as well as the previous vertical field of view of the group of channels.
  • the emission times of the ranging pulses at the field of view angle ⁇ i , the horizontal field of view angle ⁇ i+1 and the horizontal field of view angle ⁇ i+2 coincide with each other.
  • the time difference between the horizontal field of view angle ⁇ i , the horizontal field of view angle ⁇ i+1 and the horizontal field of view angle ⁇ i+2 is within a preset time range.
  • the sliding window range is introduced above through four embodiments.
  • the real ranging echo pulse is selected, which can be used as an effective echo pulse in the first detection direction, or can be used as an effective echo pulse in the first detection direction.
  • the effective echo pulse of the second detection direction can thereby reduce the amount of data calculation to a certain extent.
  • step S16 includes: when the one channel is in the first detection orientation and the second detection orientation, the difference or ratio of the amplitudes of the echo pulses with stable positions exceeds a preset threshold.
  • the stable echo pulse is regarded as the effective echo pulse of a channel in the first detection azimuth and/or the second detection azimuth.
  • the multi-dimensional sliding Window and pulse filtering can select effective echo pulses; if the ranging results of the first detection direction and the second detection direction are discontinuous, there is no need to perform sliding window and pulse filtering operations.
  • Figure 7 shows a comparison chart of ranging results between the first detection azimuth and the second detection azimuth according to an embodiment of the present invention.
  • the ranging pulse emitted by the laser 21 in the first detection azimuth and the ranging pulse emitted in the second detection azimuth.
  • the sizes of the ranging pulses are the same; the ranging echo pulses received by the corresponding detector 22 in the first detection azimuth are much larger than the ranging echo pulses received in the second detection azimuth.
  • the third The ranging result in the first detection direction ⁇ the ranging result in the second detection direction, and there is no need to perform sliding window and filtering operations.
  • the amplitude ratio of the ranging echo pulse received in the first detection azimuth to the ranging echo pulse received in the second detection azimuth is, for example, ⁇ 80%. This is only an illustrative description, and it can also be used for different detections.
  • the difference in amplitude of the ranging echo pulses between azimuths sets the threshold.
  • control method 10 is introduced through steps S10-S16 and multiple preferred embodiments.
  • steps S10-S16 By adjusting the relative lighting before and after timing of the lighting channel within a certain time range and combining with multi-dimensional sliding windows and filtering, parallelism is reduced.
  • the crosstalk between light-emitting channels improves the signal-to-noise ratio and the accuracy of ranging.
  • the above selection of different light-emitting timings is relatively random and the method is simple, taking into account the amount of data calculation and ranging accuracy.
  • the following is another preferred embodiment to encode the light-emitting timings so that the ranging results of multiple channels of parallel light emitting are the best. The ideal completely non-overlapping result makes the ranging accuracy controllable.
  • this specification provides method operation steps as described in the embodiments or flow charts, but more or less operation steps may be included based on conventional or non-inventive efforts.
  • the sequence of steps listed in the embodiment is only one way of executing the sequence of many steps, and does not represent the only execution sequence.
  • the methods shown in the embodiments or flowcharts may be executed sequentially or in parallel.
  • the lighting timing of the parallel lighting channels can be coded in advance.
  • the specific coding method will be introduced in detail in conjunction with Figures 8-13. In the following introduction, the same steps as above will not be described again. Only the improved steps and the encoding method of the lighting timing will be introduced.
  • the laser radar 20 can control the laser 21 to emit two pulses or more pulses. Referring to Figure 8, taking 3 pulses as an example, after the laser 21 emits the first detection pulse p1, it emits the second detection pulse p2 after the interval of code1, and then emits the third pulse p3 after the interval of code2. For double pulses, after the laser 21 emits the first detection pulse p1, the second detection pulse p2 is emitted after a time interval of code1. For parallel emitting channels, code1 of different sizes can be set. The above setting of specific interval times code1 and code2 for multiple pulses P1, P2 and P3 is one of the encoding methods.
  • the lidar 20 After the laser 21 emits three detection pulses P1, P2 and P3 at intervals of code1 and code2, the intervals between each other are identified from the received pulse group (there may be multiple pulses, such as more than 3 pulses) When there are 3 pulses of code1 and code2, it can be considered that the object has been detected in this luminescence measurement. If the three pulses separated by code1 and code2 are not recognized, it is considered that the object is not detected in this luminescence measurement. This recognition method is more accurate and can minimize noise, but it requires too much calculation and is easy to lose points.
  • Figure 9 shows the detection process of two channels under ideal conditions. There is no electrical crosstalk and optical crosstalk between the two channels, or the electrical crosstalk and optical crosstalk have been eliminated.
  • the pulse emitted by channel1 detects object a
  • the pulse emitted by channel2 detects object b.
  • each channel only receives the signal of the object corresponding to its own channel. If the echo pulse is reflected, the ranging result of object a is generally calculated based on the characteristics of the echo waveform. Based on the calculation results, the distance of object a can be accurately obtained.
  • Figure 10 shows a situation where there is crosstalk between two channels.
  • the pulse emitted by channel1 detects object a
  • the pulse emitted by channel2 detects object b.
  • channel1 emits three detection pulses Pa1, Pa2 and Pa3, and receives three echo pulses Ea1, Ea2 and Ea3 accordingly
  • channel2 emits three detection pulses Pb1, Pb2 and Pb3, and accordingly receives three echo pulses.
  • the three echo pulses of channel2 will generate crosstalk on channel 1 respectively, such as the crosstalk echo pulses Eb1', Eb2' and Eb3' in Figure 10.
  • the crosstalk echo pulses Eb1', Eb2' and Eb3' are respectively superimposed on the echo pulses Ea1, Ea2 and Ea3 of channel1, which will cause echoes
  • the waveforms of pulses Ea1, Ea2 and Ea3 change.
  • the final echo arrival time will be inaccurate, which will lead to inaccurate distance results. For example, there is a possibility that the distance of object a is evaluated as da' rather than the true value da.
  • channel1 receives the echo of object a + the echo of object b (which should actually appear in the direction corresponding to channel2) due to crosstalk (for the direction of channel1, object b does not actually exist) ), in this way, the echo pulse of object a may be superimposed with the crosstalk echo pulse, causing the characteristics of the echo waveform of object a to change.
  • the ranging result of object a is also calculated from the leading edge + pulse width, but there will be a certain deviation from the result without crosstalk. The degree of deviation depends on the deviation of the leading edge and pulse width.
  • W tof is related to the furthest detection distance d max of the lidar 20 .
  • the specific value of d max may be different for each lidar 20 .
  • the lidar 20 can emit a single pulse or multiple pulses.
  • the total flight time window W tof ⁇ d max can be set (in the field of lidar, distance can usually be converted and corresponded to time, so distance is used to represent the time window here, which is more accurate.
  • W tof 2*d max /c, where c is the speed of light.
  • the expression W tof ⁇ d max is still used below, and those skilled in the art can clearly understand its meaning).
  • the pulse interval is code1; if the lidar 20 emits 3 pulses P1, P2 and P3, the pulse intervals are code1 and code2 respectively; if the lidar 20 emits 4 pulses P1, P2, P3 and P4, then the pulse intervals are code1, code2 and code3 respectively.
  • the total flight time window (or detection window) W tof d max +code1.
  • the total flight time window W tof ⁇ d max +code1+code2 can be set; when 4 pulses are emitted, the total flight time window W tof ⁇ d max +code1+code2+code3 can be set.
  • the ranging pulse is the pulse used to calculate the time of flight ToF. If the laser radar 20 emits a single pulse, then the single pulse is a ranging pulse. The flight time is calculated based on the laser 21 transmitting the ranging pulse as the starting time of timing, and the detector 22 receiving the ranging pulse reflected on the object. The time from the echo pulse is the end time of timing. If the lidar 20 emits multiple pulses, one or more pulses may be selected from the multiple pulses as ranging pulses. For example, referring to Figure 11b, the laser 21 emits double pulses. If the first pulse is used as a ranging pulse, the time when the ranging pulse is emitted is t start1 , and the detector 22 receives the ranging echo pulse corresponding to the ranging pulse.
  • the time is t stop1 , then the flight time is t stop1 - tstart1 .
  • this formula is not an accurate way to calculate the flight time in lidar.
  • there may be offset offset for the transmitter such as taking into account the temperature drift of the laser, the response of the laser, etc.
  • the setting of the received signal threshold threshold will be involved. For example, the time point when the intensity of the received echo pulse is greater than the threshold is used as the end time of timing. This is only an exemplary explanation, and the present invention does not limit the specific calculation method of flight time.
  • step S11 includes:
  • the first lighting timing and the second lighting timing are determined in the following manner: based on one or more of the previous ranging results of each channel in the group of channels, the previous ranging results of the channels adjacent to the channel, and the obstacle information , determine the first lighting timing and the second lighting timing, and the first lighting timing and the second lighting timing are configured such that: the first group of echo pulses and the second group of echo pulses are staggered from each other in time.
  • the previous ranging results and obstacle information of each channel in the group of channels and the channels adjacent to the channel predict the time of the ranging echo pulse corresponding to the ranging pulse to be sent, and determine the first lighting timing and the second Lighting timing. For example, based on the ranging results of each channel and its adjacent channels in the group of channels at the horizontal field of view angle ⁇ i-1 , predict the ranging results of the channel at the horizontal field of view angle ⁇ i and ⁇ i+1 , based on The prediction result sets the first lighting timing and the second lighting timing.
  • the first lighting timing and the second lighting timing are set based on the prediction result. For another example, combining object recognition (for example, whether the object is a static obstacle, a slow obstacle, or a fast-moving obstacle) and distance prediction technologies, the previous ranging results are combined to predict the ranging results of the ranging pulse to be sent. , the first lighting timing and the second lighting timing are set based on the prediction result.
  • the purpose of setting the light-emitting timing of the laser 21 to be detected by using any one or more of the above methods is to realize that the ranging pulses of at least part of the parallel light-emitting channels are staggered from each other, preferably The ranging pulses of each parallel light-emitting channel in the set of channels are staggered.
  • the specific degree of staggering is based on the standard that the subsequent processor can distinguish the ranging echo pulses and interference pulses of its own channel without affecting the ranging accuracy of the channel.
  • the first lighting timing and the second lighting timing are set based on the previous ranging results. It can be seen that the accuracy of the previous ranging results directly affects the setting of the lighting timing and the staggering of the ranging echo pulses. Effect. How to improve the accuracy of ranging results is further described below through preferred embodiments.
  • each channel emits multiple pulses
  • at least two pulses can be selected from the multiple pulses as ranging pulses, and the measurement can be obtained based on at least two ranging pulses. distance results, thereby reducing the impact of signal crosstalk and improving the accuracy of ranging results.
  • multiple distances can be calculated based on the multiple ranging pulses and the corresponding multiple ranging echo pulses, and then based on the multiple ranging pulses
  • the preset weight of the pulses is used to calculate the ranging results by weighting the multiple distances, which can reduce the impact of crosstalk on ranging and improve ranging accuracy. For example, if 4 pulses are emitted, refer to Figure 11a. The 4 pulses are P1, P2, P3 and P4. You can choose to use P1-P4 as ranging pulses.
  • each pulse's contribution to the final ranging result d is the same, which is 1. It can also be considered according to different weights. For example, each pulse is assigned a different weight Xi , 1>Xi& gt ;0. For example, if you choose to use P1-P4 as ranging pulses, the final ranging result
  • the above embodiments illustrate how to improve the accuracy of ranging results.
  • the total flight time window can be divided into intervals in advance. Dividing and then allocating unmarked and unoccupied intervals to each ranging echo pulse enables more precise control of the position of the ranging echo pulse, which will be further described below through preferred embodiments.
  • control method 10 further includes: dividing the total flight time window of the laser of the group of channels into at least a first interval and a second interval, wherein the first emission timing is configured such that: the first group returns The wave pulses are distributed in the second interval without overlapping, and the second lighting timing is configured such that the second group of echo pulses and the first group of echo pulses are distributed in the second interval without overlapping.
  • Figure 12a shows a schematic diagram of the total flight time window division according to an embodiment of the present invention.
  • the total flight time window is divided into two intervals, where the first interval is used to place other pulses in front of the ranging echo pulse, and the second interval is To place the ranging echo pulses of each channel.
  • the timing of at least part of the ranging echo pulses respectively generated by the ranging pulses to be emitted by the lasers 21 of the plurality of channels of each group is predicted.
  • the non-coincidence of ranging echo pulses includes that the ranging echo pulses are staggered from each other in time, separated from each other, do not overlap, are spaced apart, fall at different positions, etc.
  • control method 10 further includes: dividing the second interval into k sub-intervals, where k is an integer and greater than or equal to the number of channels in the group, wherein the first lighting timing is configured such that: One group of echo pulses is distributed in k sub-intervals without overlapping; the second lighting timing is configured such that: the second group of echo pulses and the first group of echo pulses are distributed within k sub-intervals without overlapping.
  • Figure 12b shows a schematic diagram of the division of the total flight time window according to another embodiment of the present invention.
  • the total flight time window is divided into k+1 sub-intervals, respectively G0, G1, G2,..., Gk, where G0 is equivalent to the first interval, used to place other pulses before the first received ranging echo pulse; G1-Gk is used to place the ranging echo pulse, where G1 is equivalent to the theoretically existing third range used to place the ranging echo pulse.
  • 1 sub-interval ideally, the non-ranging pulses before the first received ranging echo pulse are concentrated in G0, rather than appearing in G1-Gk.
  • the length of each sub-interval is greater than the maximum pulse width of the ranging echo pulse of the lidar.
  • the length of each interval is assumed to be G, and G is greater than the maximum pulse width of the ranging echo pulse to ensure that each sub-interval can Set a ranging echo pulse.
  • G Preferably, G ⁇ 2 times the pulse width.
  • the pulse width of each lidar may be different. When the maximum pulse width is about 30 ns, G is preferably 60 ns or more.
  • the length division principle of the first interval (that is, the G0 interval) is that other pulses in front of the ranging echo pulse can be placed at the minimum ranging distance.
  • the time window length of G0 is (W tof -k*G).
  • G1 is the first sub-interval that can theoretically be used to place ranging echo pulses. Try to hope that non-ranging echo pulses are concentrated in GO and do not appear.
  • the sub-interval G1 ⁇ Gk the sub-interval G1 ⁇ Gk can be used to place the ranging echo pulses of each channel.
  • the length of the G0 interval is preferably such that the first echo pulse and the second echo pulse can be placed at the minimum ranging distance.
  • the interval of G1 is approximately [d min +code1+code2, d min +code1+code2+G], so G1 is equivalent to a theoretical range used to place the ranging echo pulse (in this embodiment, that is, the third pulse echo pulse) first sub-interval.
  • k must be at least greater than or equal to the number of parallel light-emitting channels.
  • k is greater than the number of parallel emitting channels. This is because it is necessary to ensure that the ranging echo pulses of each channel emitting light in parallel occupy an exclusive sub-interval, that is, they are distributed in the sub-interval G1 ⁇ Gk without overlapping, and it is also necessary to consider that for channels with relatively far obstacles, their non-measurement The distance pulse may also occupy some sub-intervals.
  • the first lighting timing and the second lighting timing can be further It is configured such that at least part of the ranging echo pulses generated by the ranging pulses emitted by the laser 21 of each channel do not coincide with the non-ranging echo pulses generated by the non-ranging pulses emitted by the lasers 21 of other channels in the group.
  • the first lighting timing is configured such that: the first group of echo pulses are distributed in the unoccupied and closest sub-intervals of the k sub-intervals;
  • the two lighting timings are configured such that the second group of echo pulses are distributed in the unoccupied and closest sub-intervals among the k sub-intervals. Placing each ranging echo pulse in an unoccupied sub-interval can avoid the impact of crosstalk on the ranging results. Furthermore, each ranging echo pulse is placed in the nearest sub-interval as much as possible to shorten the measurement time and improve measurement efficiency.
  • the encoding method of light emission timing will be described in detail through embodiments below.
  • a set of 4 channels (Channel 1, Channel 2, Channel 3 and Channel 4) of lasers 21 emit light in parallel, and the laser 21 of each channel emits 3 pulses, of which the 3rd pulse is the measured distance pulse.
  • the total flight time window is divided into sub-intervals of G0 and G1-Gk, where the midpoint position of the G1-Gk sub-interval is g1-gk.
  • each channel emits 3 pulses, the time interval between the first pulse and the second pulse is code1, and the time interval between the second pulse and the third pulse is code2.
  • code1 is set to a fixed value, but those skilled in the art can understand that in order to prevent crosstalk from other radars, code1 can also be set to different values, that is, to encode the pulse interval;
  • the minimum value of the pulse interval code1 and code2 is defined as Cmin.
  • Cmin is related to the processing speed of the laser charging circuit of the emission channel.
  • Cmin ⁇ pulse width/2 can be set to more accurately distinguish two adjacent pulses.
  • control method 10 After making the above settings, according to control method 10, first obtain the previous ranging results.
  • Four channels, Channel 1, Channel 2, Channel 3 and Channel 4 emit light in parallel, and the ranging results at the horizontal field of view angle ⁇ i-1 are d1, d2, d3 and d4 respectively.
  • the position (time) of the ranging echo pulses of the four channels Channel 1, Channel 2, Channel 3 and Channel 4 at the horizontal field of view angle ⁇ i is predicted based on the previous ranging results, and based on the predicted ranging echo pulse
  • the first lighting timing sequence is set at the position, that is, the code2 of the lighting pulse at the angle ⁇ i is encoded. Specifically, the following steps are performed before lighting:
  • the lasers 21 of the four channels are controlled to emit light according to the first light-emitting timing.
  • the ranging echo pulses generated by the four parallel emitting channels are staggered in time, reducing or avoiding the crosstalk problem.
  • the receiving end of each channel in Figure 14 only shows the ranging echo pulses. To avoid confusion, the non-ranging echo pulses are not shown.
  • the encoding method of the second lighting timing is the same as above and will not be described again here.
  • the measurement of each channel The echo pulses will be divided into Gk intervals.
  • the farther away the object is the weaker the crosstalk (the farther the obstacle is, the echo from each channel is very weak, and the crosstalk to each other is also very weak), and the distance measurement accuracy requirement is lower, so it can also Meet the ranging requirements.
  • the invention also relates to a computer storage medium including computer executable instructions stored thereon, which when executed by a processor implement the control method 10 as described above.
  • the present invention also relates to a laser radar 20, as shown in Figure 14, including:
  • a plurality of detectors 22, such as detectors 22-1, ..., detectors 22-n, the plurality of lasers 21 and the plurality of detectors 22 constitute a plurality of channels, each channel includes at least one laser 21 and at least one detector 22;
  • Control device 23 The control device 23 is connected to the plurality of lasers 21 and the plurality of detectors 22, and divides the plurality of channels into multiple groups. Each group of channels emits light in parallel.
  • the control device 23 Configured as:
  • For one of the groups of channels determine the lighting timing of the laser 21 of the group of channels, wherein the first lighting timing used in the first detection orientation and the second lighting timing used in the second detection orientation are different;
  • the laser 21 that controls the group of channels emits the first group of detection pulses according to the first light-emitting timing sequence
  • the detectors 22 passing through the set of channels respectively receive the first set of echo pulses reflected from the object by the first set of detection pulses;
  • the laser 21 that controls the group of channels emits a second group of detection pulses according to the second light emission timing sequence
  • the detectors 22 passing through the set of channels respectively receive the second set of echo pulses reflected from the object by the second set of detection pulses;
  • For a channel in the group of channels determine the echo pulse with a stable position of the one channel at the first detection orientation and the second detection orientation, as the echo pulse for the one channel at the first detection orientation and/or the second detection orientation. Two effective echo pulses in the detection direction.
  • the lasers 21 of the group of channels do not emit light at the same time.
  • the control device 23 is configured to: match according to time degree, and determine the echo pulse whose position coincides with that of one channel at the first detection orientation and the second detection orientation.
  • At least one of the pulses emitted by the laser 21 of the group of channels is used as a ranging pulse
  • the control device 23 is configured to: for a channel in the group of channels, relatively translate the one The emission times of the ranging pulses of the channel at the first detection azimuth and the second detection azimuth overlap until the ranging results of the two times are compared, and an echo pulse with a stable position is selected.
  • the detectors 22 passing through the group of channels respectively receive the ranging echo pulses reflected from the object
  • the control device 23 is configured to: for one of the channels in the group channel, relatively translate the emission time of the ranging pulses of one channel in the first detection azimuth and the second detection azimuth until they coincide, and the ranging echo pulses that are staggered from each other in time are Positionally stable echo pulse.
  • the control device 23 is configured to: determine the lighting timing sequence of the laser 21 of the group of channels at at least one other detection orientation after the second detection orientation, wherein the at least one other detection orientation
  • the lighting timing is different from the first lighting timing and the second lighting timing
  • the control device 23 is also configured to: for one channel in the group of channels, determine whether the one channel is in the first detection orientation, the second detection direction, and the second lighting timing.
  • the echo pulses with stable positions in the detection direction and at least one other detection direction are used as the effective echo pulses of the one channel in the first detection direction and/or the second detection direction.
  • the time difference between the first detection position, the second detection position and the at least one other detection position is within a preset time range.
  • control device 23 is further configured to: determine where the one channel is based on the echo pulses of at least one second channel at the first detection orientation and the second detection orientation. Echo pulses with stable positions in the first and second detection directions.
  • control device 23 is further configured to: when the one channel is in the first detection orientation and the second detection orientation, the difference in amplitude of the echo pulse with stable position or When the ratio exceeds the preset threshold, the stable echo pulse is used as the effective echo pulse of the one channel in the first detection orientation and/or the second detection orientation.
  • control device 23 is further configured to determine the first lighting timing and the second lighting timing in the following manner: based on the previous ranging results of each channel in the group of channels, and The first lighting timing and the second lighting timing are determined by one or more of the previous ranging results of the channels adjacent to the channel and the obstacle information, and the first lighting timing and the second lighting timing are configured such that: The first set of echo pulses and the second set of echo pulses are offset in time from each other.
  • control device 23 is further configured to: divide the total flight time window of the laser 21 of the group of channels into at least a first interval and a second interval, wherein the first emission timing configuration Such that: the first group of echo pulses are distributed in the second interval without overlapping, and the second lighting timing is configured such that: the second group of echo pulses are distributed without overlapping with the first group of echo pulses. within the second interval.
  • control device 23 is further configured to: divide the second interval into k sub-intervals, where k is an integer and greater than or equal to the number of channels in the group, wherein the first The lighting timing is configured such that: the first group of echo pulses are distributed in the k sub-intervals without overlapping; the second lighting timing is configured such that: the second group of echo pulses are not coincident with the first group of echo pulses. Coincidentally distributed within the k sub-intervals.
  • the length of each sub-interval is greater than the maximum pulse width of the echo pulse.
  • control device 23 is further configured to: the first lighting timing is configured such that: the first group of echo pulse distribution is not occupied in the k sub-intervals and the distance within the nearest sub-interval; the second lighting timing is configured such that the second group of echo pulses are distributed in the unoccupied and nearest sub-interval among the k sub-intervals.

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Abstract

一种激光雷达的控制方法，包括：将多个通道分为多组，每个组的所有通道并行发光（S10）；对于其中一组通道，确定该组通道的激光器发光时序（S11）；在第一探测方位，控制该组通道的激光器按照第一发光时序发射第一组探测脉冲（S12）；通过该组通道的探测器分别接收第一组探测脉冲自物体反射的第一组回波脉冲（S13）；在第二探测方位，控制该组通道的激光器按照第二发光时序发射第二组探测脉冲（S14）；通过该组通道的探测器分别接收第二组探测脉冲自物体反射的第二组回波脉冲（S15）；对于该组通道内的一个通道，根据一个通道的第一组回波脉冲和第二组回波脉冲，确定一个通道的有效回波脉冲（S16）。该方法可降低并行发光通道间的串扰，提高信噪比及测距精度。还提供了一种激光雷达及一种计算机存储介质。

Description

激光雷达的控制方法、计算机存储介质以及激光雷达 技术领域
本公开涉及光电探测技术领域，尤其涉及一种激光雷达的控制方法、一种计算机存储介质以及一种激光雷达。
背景技术
激光雷达作为一种三维测量系统，通过采集的点云实现对测量区域三维测量覆盖。基于时间飞行法(Time of Flight，ToF)的多通道激光雷达可采用多个发射和接收通道，适合要求扫描大视场并且获取高密度点云的情况。
如图1中的128个激光器，呈32行4列排布，其中激光器11表示位于第1列第1行的激光器，激光器12表示位于第1列第2行的激光器，激光器41表示位于第4列第1行的激光器。如果需要提升点云的分辨率或点云频率，可以通过增加并行发光的通道数量的方式，例如：某一款激光雷达并行发光的通道数量为8个，继续参考图1，挑选激光器11、13、22、24、33、34、44、42作为一组激光器并行发光，并行探测，此时并行探测的通道为channel1-channel8，则可以在1.333us时间内生成8个测距上限为200m的点。128个激光器分为16组，每组并行发光，并行探测，通过这样的方式，相比于同一时刻只有一个激光器发光的激光雷达，点云的分辨率提升到八倍。
图2a示出了激光雷达垂直视场角示意图，图中为激光雷达的垂直方向的剖视图，垂直视场角为激光雷达在垂直方向上可以探测的角度范围，垂直排布的多个激光器发出的探测光束分别对应线束1、线束2、……、线束40，垂直视场角为23°(从向下的-16°到向上的7°)。激光雷达输出的点云图像中，与旋转轴平行的垂直平面上相邻两个点之间的夹角为垂直角分辨率。为了更好的利用激光进行探测，会把探测光束集中到中间感兴趣的区域，因此探测光束并非垂直均匀分布，而是中间密集，两边稀疏。
图2b示出了激光雷达水平视场角示意图，图中为激光雷达在水平方向的 剖视图，水平视场角为激光雷达在水平方向上可以探测的角度范围，例如机械式激光雷达旋转一周为360°，则水平视场角为360°。激光雷达输出的点云图像中，与旋转轴垂直的水平面(垂直纸面方向)上相邻两个点之间的夹角为水平角分辨率，例如水平角分辨率为0.2°。
多通道并行发光测量引入了光串扰和电串扰的问题。
光串扰即激光雷达相邻通道并行发光造成的干扰。继续参考图1，激光雷达多通道并行发光时，每个通道的探测器都会接收到来自其他通道发射的探测脉冲在目标物体上的反射光。反射光的强度随距离减小而增强，目标的反射率越高，反射光的强度越高。当其他通道造成的反射光的强度达到一定程度时，会在本通道探测器接收的波形上产生干扰的脉冲波形(会和真正障碍物造成的回波脉冲叠加，而真正的回波脉冲是后续计算距离及反射率的依据，因此距离和反射率的计算都会被干扰，造成结果不准确)。上述光串扰是影响测距精度的主要因素，多发生在近处高反板的场景下。
电串扰即激光雷达多个通道同时接收电信号时，电信号较强的通道的信号会通过电路直接串扰到其余的接收通道上，产生干扰的脉冲波形。
综上所述，多通道间容易发生信号串扰而导致探测结果不准确，如何消除或者降低通道之间的彼此串扰的影响、提高探测的精准度是多通道激光雷达所面临的问题。
背景技术部分的内容仅仅是公开发明人所知晓的技术，并不当然代表本领域的现有技术。
发明内容
有鉴于现有的一个或多个缺陷，本发明涉及一种激光雷达的控制方法，通过调整并行发光通道在一定时间范围内的相对发光前后时序，让串扰变得随机，并结合多个角度的回波的滤波，挑选出在多个探测方位上位置稳定的回波脉冲，作为被探测方向上的物体反射的真正回波信号，可以降低并行发光通道之间的串扰，提高信噪比及测距的精准度。具体地，所述激光雷达包括多个通道，每个通道包括至少一个激光器和至少一个探测器，所述控制方 法包括：
S11：其中所述多个通道分为多组，每组通道并行发光，对于其中一组通道，确定该组通道的激光器的发光时序，其中在第一探测方位所用的第一发光时序和在第二探测方位所用的第二发光时序不同；
S12：在所述第一探测方位，控制该组通道的激光器按照所述第一发光时序发射第一组探测脉冲；
S13：通过该组通道的探测器分别接收所述第一组探测脉冲自物体反射的第一组回波脉冲；
S14：在所述第二探测方位，控制该组通道的激光器按照所述第二发光时序发射第二组探测脉冲；
S15：通过该组通道的探测器分别接收所述第二组探测脉冲自物体反射的第二组回波脉冲；
S16：对于该组通道内的一个通道，根据所述一个通道稳定的第一组回波脉冲和第二组回波脉冲，确定所述一个通道的有效回波脉冲。
根据本发明的一个优选实施例，其中所述第一发光时序和第二发光时序中，该组通道的至少部分激光器不同时发光。
根据本发明的一个优选实施例，其中在步骤S13和S15中，该组通道中每个通道的探测器接收的回波脉冲包括有效回波脉冲和由其他通道产生的串扰，所述步骤S16包括：根据时间匹配度，确定所述一个通道在所述第一探测方位和第二探测方位时重合的回波脉冲。
根据本发明的一个优选实施例，其中在步骤S12和S14中，该组通道的激光器发射的脉冲中至少一个脉冲作为测距脉冲，所述步骤S16包括：对于该组通道内的一个通道，相对平移所述一个通道在所述第一探测方位和第二探测方位的测距脉冲的发射时间至重合，比对两次的测距结果，选出位置稳定的回波脉冲。
根据本发明的一个优选实施例，其中在步骤S13和S15中，通过该组通道的探测器分别接收所述测距脉冲自物体反射的测距回波脉冲，所述步骤S16包括：对于该组通道内的一个通道，相对平移所述一个通道在所述第一探测 方位和第二探测方位的测距脉冲的发射时间至重合，在时间上相互错开的测距回波脉冲为位置稳定的回波脉冲。
根据本发明的一个优选实施例，其中所述步骤S11还包括：确定该组通道的激光器在第二探测方位之后的至少一个其他探测方位的发光时序，其中所述在至少一个其他探测方位的发光时序不同于所述第一发光时序和第二发光时序，所述步骤S16包括：对于该组通道内的一个通道，确定所述一个通道在所述第一探测方位、第二探测方位以及至少一个其他探测方位时位置稳定的回波脉冲，作为所述一个通道在所述第一探测方位和/或第二探测方位的有效回波脉冲。
根据本发明的一个优选实施例，其中所述第一探测方位和所述第二探测方位以及所述至少一个其他探测方位的时间差在预设时间范围内。
根据本发明的一个优选实施例，其中所述步骤S16还包括：根据至少一个第二通道在所述第一探测方位和第二探测方位时的回波脉冲，确定所述一个通道在所述第一探测方位和第二探测方位时位置稳定的回波脉冲。
根据本发明的一个优选实施例，其中所述步骤S16包括：当所述一个通道在所述第一探测方位和第二探测方位时位置稳定的回波脉冲的幅值的差值或比值超过预设阈值时，将所述稳定的回波脉冲作为所述一个通道在所述第一探测方位和/或第二探测方位的有效回波脉冲。
根据本发明的一个优选实施例，其中所述步骤S11包括：
通过以下方式确定所述第一发光时序和第二发光时序：根据该组通道中每个通道之前的测距结果、与该通道邻近的通道之前的测距结果以及障碍物信息中的一项或多项，确定所述第一发光时序和第二发光时序，所述第一发光时序和第二发光时序配置成使得：第一组回波脉冲和第二组回波脉冲在时间上相互错开。
根据本发明的一个优选实施例，所述控制方法还包括：将该组通道的激光器的总飞行时间窗口至少分为第一区间和第二区间，其中所述第一发光时序配置成使得：第一组回波脉冲不重合地分布在所述第二区间内，所述第二发光时序配置成使得：第二组回波脉冲与第一组回波脉冲不重合地分布在所 述第二区间内。
根据本发明的一个优选实施例，所述控制方法还包括：将所述第二区间分为k个子区间，其中k为整数并且大于等于该组内通道的数目，其中所述第一发光时序配置成使得：第一组回波脉冲不重合地分布在所述k个子区间内；所述第二发光时序配置成使得：第二组回波脉冲与第一组回波脉冲不重合地分布在所述k个子区间内。
根据本发明的一个优选实施例，其中所述每个子区间的长度大于所述回波脉冲的最大脉宽。
根据本发明的一个优选实施例，其中所述第一发光时序配置成使得：所述第一组回波脉冲分布在所述k个子区间中未被占用并且距离最近的子区间内；所述第二发光时序配置成使得：所述第二组回波脉冲分布在所述k个子区间中未被占用并且距离最近的子区间内。
本发明还涉及一种计算机存储介质，包括存储于其上的计算机可执行指令，所述可执行指令在被处理器执行时实施如权利要求1-14中任一项所述的控制方法。
本发明还涉及一种激光雷达，包括：
多个激光器，每个激光器发射的脉冲中至少一个脉冲作为测距脉冲；
多个探测器，所述多个激光器和所述多个探测器构成多个通道，每个通道包括至少一个激光器和至少一个探测器；
控制装置，所述控制装置与所述多个激光器和所述多个探测器连接，所述控制装置配置成：
将所述多个通道分为多组，每组通道并行发光，对于其中一组通道，确定该组通道的激光器的发光时序，其中在第一探测方位所用的第一发光时序和在第二探测方位所用的第二发光时序不同；
在所述第一探测方位，控制该组通道的激光器按照所述第一发光时序发射第一组探测脉冲；
通过该组通道的探测器分别接收所述第一组探测脉冲自物体反射的第一组回波脉冲；
在所述第二探测方位，控制该组通道的激光器按照所述第二发光时序发射第二组探测脉冲；
通过该组通道的探测器分别接收所述第二组探测脉冲自物体反射的第二组回波脉冲；
对于该组通道内的一个通道，根据所述一个通道的第一组回波脉冲和第二组回波脉冲，确定所述一个通道的有效回波脉冲。
根据本发明的一个优选实施例，其中所述第一发光时序和第二发光时序中，该组通道的至少部分激光器不同时发光。
根据本发明的一个优选实施例，其中该组通道中每个通道的探测器接收的回波脉冲包括有效回波脉冲和由其他通道产生的串扰，所述控制装置配置成：根据时间匹配度，确定所述一个通道在所述第一探测方位和第二探测方位时重合的回波脉冲。
根据本发明的一个优选实施例，其中该组通道的激光器发射的脉冲中至少一个脉冲作为测距脉冲，所述控制装置配置成：对于该组通道内的一个通道，相对平移所述一个通道在所述第一探测方位和第二探测方位的测距脉冲的发射时间至重合，比对两次的测距结果，选出位置稳定的回波脉冲。
根据本发明的一个优选实施例，其中通过该组通道的探测器分别接收所述测距脉冲自物体反射的测距回波脉冲，所述控制装置配置成：对于该组通道内的一个通道，相对平移所述一个通道在所述第一探测方位和第二探测方位的测距脉冲的发射时间至重合，在时间上相互错开的测距回波脉冲为位置稳定的回波脉冲。
根据本发明的一个优选实施例，其中所述控制装置配置成：确定该组通道的激光器在第二探测方位之后的至少一个其他探测方位的发光时序，其中所述在至少一个其他探测方位的发光时序不同于所述第一发光时序和第二发光时序，所述控制装置还配置成：对于该组通道内的一个通道，确定所述一个通道在所述第一探测方位、第二探测方位以及至少一个其他探测方位时位置稳定的回波脉冲，作为所述一个通道在所述第一探测方位和/或第二探测方位的有效回波脉冲。
根据本发明的一个优选实施例，其中所述第一探测方位和所述第二探测方位以及所述至少一个其他探测方位的时间差在预设时间范围内。
根据本发明的一个优选实施例，其中所述控制装置还配置成：根据至少一个第二通道在所述第一探测方位和第二探测方位时的回波脉冲，确定所述一个通道在所述第一探测方位和第二探测方位时位置稳定的回波脉冲。
根据本发明的一个优选实施例，其中所述控制装置还配置成：当所述一个通道在所述第一探测方位和第二探测方位时位置稳定的回波脉冲的幅值的差值或比值超过预设阈值时，将所述稳定的回波脉冲作为所述一个通道在所述第一探测方位和/或第二探测方位的有效回波脉冲。
根据本发明的一个优选实施例，其中所述控制装置还配置成：通过以下方式确定所述第一发光时序和第二发光时序：根据该组通道中每个通道之前的测距结果、与该通道邻近的通道之前的测距结果以及障碍物信息中的一项或多项，确定所述第一发光时序和第二发光时序，所述第一发光时序和第二发光时序配置成使得：第一组回波脉冲和第二组回波脉冲在时间上相互错开。
根据本发明的一个优选实施例，其中所述控制装置还配置成：将该组通道的激光器的总飞行时间窗口至少分为第一区间和第二区间，其中所述第一发光时序配置成使得：第一组回波脉冲不重合地分布在所述第二区间内，所述第二发光时序配置成使得：第二组回波脉冲与所述第一组回波脉冲不重合地分布在所述第二区间内。
根据本发明的一个优选实施例，其中所述控制装置还配置成：将所述第二区间分为k个子区间，其中k为整数并且大于等于该组内通道的数目，其中所述第一发光时序配置成使得：第一组回波脉冲不重合地分布在所述k个子区间内；所述第二发光时序配置成使得：第二组回波脉冲与所述第一组回波脉冲不重合地分布在所述k个子区间内。
根据本发明的一个优选实施例，其中所述每个子区间的长度大于所述回波脉冲的最大脉宽。
根据本发明的一个优选实施例，其中所述控制装置还配置成：所述第一发光时序配置成使得：所述第一组回波脉冲分布在所述k个子区间中未被占 用并且距离最近的子区间内；所述第二发光时序配置成使得：所述第二组回波脉冲分布在所述k个子区间中未被占用并且距离最近的子区间内。
本发明的方案，激光雷达在第一探测方位所用的第一发光时序和在第二探测方位所用的第二发光时序不同，以使得串扰变得随机，便于挑选出位置稳定的真正的回波脉冲，进而提高探测的精准度，减少噪点。
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示出了现有的多通道激光雷达中激光器的排布示意图；
图2a示出了激光雷达垂直视场角示意图；
图2b示出了激光雷达水平视场角示意图；
图3a示出了本发明一个实施例的激光雷达的控制方法流程图；
图3b示出了本发明一个实施例的激光雷达结构及探测示意图；
图4示出了本发明一个实施例的第一探测方位和第二探测方位的发光时序对比图；
图5a示出了本发明一个实施例的第一探测方位和第二探测方位的收发示意图；
图5b示出了对图5a中的通道1进行滑窗处理的示意图；
图5c示出了图5a中的2个探测方位的探测和滑窗方式示意图；
图6a示出了本发明一个实施例的第一种滑窗范围示意图；
图6b示出了本发明一个实施例的第二种滑窗范围示意图；
图6c示出了本发明一个实施例的第三种滑窗范围示意图；
图6d示出了本发明一个实施例的第四种滑窗范围示意图；
图7示出了本发明一个实施例的第一探测方位和第二探测方位测距结果对比图；
图8示出了3个脉冲发光编码设置的示意图；
图9示出了在没有串扰时，2个通道并行发射3个脉冲的发射和接收示意图；
图10示出了两个通道存在串扰的示意图；
图11a示出了多脉冲时间间隔的示意图；
图11b示出了发射双脉冲时总飞行时间窗口的示意图；
图12a示出了本发明一个实施例的总飞行时间窗口划分示意图；
图12b示出了本发明另一个实施例的总飞行时间窗口划分示意图；
图13示出了本发明一个实施例的θi角度下的第一发光时序和测距结果示意图；
图14示出了本发明一个实施例的激光雷达的示意图。
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。
本申请的发明人构思出：通过调整并行发光通道在一定时间范围内的相对发光前后时序，让串扰变得随机，进而通过脉冲滤波，挑选出在2个探测方位上位置稳定的回波脉冲，作为被探测方向上的物体反射的真正回波信号。
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。
图3a示出了本发明一个实施例的激光雷达的控制方法流程图，还可以结合参考图3b示出的激光雷达20，激光雷达20包括多个通道，每个通道包括至少一个激光器21和至少一个探测器22，控制方法10包括步骤S10-S16，具体如下：
在步骤S10：把多个通道分为多组，每组通道并行发光。所述“并行发 光”指多个通道在一个时间窗口内，完成信号发射和接收回波，这些通道彼此之间的发光时间可以有重叠，但不必然需要同时发光或者收光。为完成对障碍物与雷达之间的距离进行的一次探测，激光器可以在t1时刻发光，遇到预设该雷达可以探测到的最远dmax处的障碍物之后返回，回波于t2被探测器接收到，时间窗口≈dmax/2C(C为光速)≈t2-t1。
在步骤S11：对于其中一组通道，确定该组通道的激光器21的发光时序，其中在第一探测方位所用的第一发光时序和在第二探测方位所用的第二发光时序不同。
其中，发光时序是指一组通道中多个激光器21的相对发光的时间顺序，也就是开始发光的时间顺序。
根据本发明的一个优选实施例，其中第一发光时序和第二发光时序中，该组通道的至少部分激光器21不同时发光。
图4示出了本发明一个实施例的第一探测方位和第二探测方位的发光时序对比图，该组通道包括通道1、通道2、通道3和通道4，每个通道包括一个激光器21，在第一探测方位的第一发光时序为：首先通道1的激光器21和通道3的激光器21同时发光，然后通道2的激光器21发光，最后通道4的激光器21发光；在第二探测方位的第二发光时序为：通道2的激光器21先发光，然后通道1的激光器21和通道4的激光器21同时发光，最后通道3的激光器21发光。
第一探测方位和第二探测方位之间的间隔为激光雷达20的垂直角分辨率或者水平角分辨率。在第一探测方位所用的第一发光时序和在第二探测方位所用的第二发光时序不同，以使得串扰变得随机，便于挑选出真正的回波脉冲。
下文以第一探测方位和第二探测方位之间的间隔为水平角分辨率为例进一步描述。
在步骤S12：在第一探测方位，控制该组通道的激光器21按照第一发光时序发射第一组探测脉冲。
根据本发明的一个优选实施例，在步骤S12该组通道的激光器21发射的 脉冲中至少一个脉冲作为测距脉冲。
图5a示出了本发明一个实施例的第一探测方位和第二探测方位的收发示意图，该组通道包括通道1、通道2、通道3和通道4，每个通道包括一个激光器21，在第一探测方位的第一发光时序为：首先通道1的激光器21发射测距脉冲A，然后通道2的激光器21发射测距脉冲B，接着通道3的激光器21发射测距脉冲C，最后通道4的激光器21发射测距脉冲D。其中，通道1-4的激光器21可以发射单脉冲，也可以发射多脉冲，每个激光器21发射的脉冲中至少一个脉冲作为测距脉冲。图5a中在第一探测方位以每个通道包括一个测距脉冲为例进行介绍，为清楚显示，图5a中仅示出了各通道的测距脉冲。
在步骤S13：通过该组通道的探测器22分别接收第一组探测脉冲自物体反射的第一组回波脉冲。
根据本发明的一个优选实施例，在步骤S13该组通道中每个通道的探测器22接收的回波脉冲包括有效回波脉冲和由其他通道产生的串扰。
在该组通道的激光器21发射测距脉冲后，通过该组通道的探测器22分别接收所述测距脉冲自物体反射的测距回波脉冲。
继续参考图5a，每个通道包括一个探测器22，在第一探测方位：通道1的探测器22接收到测距脉冲A被目标物反射后的测距回波脉冲A’，通道2的探测器22接收到测距脉冲B被目标物反射后的测距回波脉冲B’，通道3的探测器22接收到测距脉冲C被目标物反射后的测距回波脉冲C’，通道4的探测器22接收到测距脉冲D被目标物反射后的测距回波脉冲D’。其中，通道1还接收到测距回波脉冲B’对应的串扰、测距回波脉冲C’对应的串扰以及测距回波脉冲D’对应的串扰。为简化附图及描述，串扰与测距回波脉冲采用相同的附图标记，且其他通道的串扰未在图5a中示出。
在步骤S14：在第二探测方位，控制该组通道的激光器21按照第二发光时序发射第二组探测脉冲，发光时序可以指开始发光的时间点。
根据本发明的一个优选实施例，在步骤S14该组通道的激光器21发射的脉冲中至少一个脉冲作为测距脉冲。
继续参考图5a，在第二探测方位的第二发光时序为：首先通道4的激光器21发射测距脉冲D，然后通道3的激光器21发射测距脉冲C，接着通道2的激光器21发射测距脉冲B，最后通道1的激光器21发射测距脉冲A。图5a中在第二探测方位以每个通道包括一个测距脉冲为例进行介绍，为清楚显示，图5a中仅示出了各通道的测距脉冲。
在步骤S15：通过该组通道的探测器22分别接收第二组探测脉冲自物体反射的第二组回波脉冲。
根据本发明的一个优选实施例，在步骤S15该组通道中每个通道的探测器22接收的回波脉冲包括有效回波脉冲和由其他通道产生的串扰。
在该组通道的激光器21发射测距脉冲后，通过该组通道的探测器22分别接收所述测距脉冲自物体反射的测距回波脉冲。
继续参考图5a，在第二探测方位：通道1的探测器22接收到测距脉冲A被目标物反射后的测距回波脉冲A’，通道2的探测器22接收到测距脉冲B被目标物反射后的测距回波脉冲B’，通道3的探测器22接收到测距脉冲C被目标物反射后的测距回波脉冲C’，通道4的探测器22接收到测距脉冲D被目标物反射后的测距回波脉冲D’。其中，通道1还接收到测距回波脉冲B’对应的串扰、测距回波脉冲C’对应的串扰以及测距回波脉冲D’对应的串扰。为简化附图及描述，串扰与测距回波脉冲采用相同的附图标记，且其他通道的串扰未在图5a中示出。
在步骤S16：对于该组通道内的一个通道，根据所述一个通道的一组回波脉冲和第二组回波脉冲，确定一个通道的有效回波脉冲。
确定一个通道的有效回波脉冲，可以通过确定一个通道在第一探测方位和第二探测方位时位置稳定的回波脉冲来实现，所谓位置稳定是指某个回波脉冲在第一回波脉冲和第二回波脉冲中，出现的位置的相对偏差极小，基本是固定和稳定的，没有出现超过预设某个阈值的波动或者偏离，从而可以作为一个通道在第一探测方位和/或第二探测方位的有效回波脉冲。这是因为在第一探测方位所用的第一发光时序和在第二探测方位所用的第二发光时序不同，串扰的信号出现的位置会变得随机，而真正的回波在第一回波脉冲和第 二回波脉冲中可以出现在基本一致的位置，故而通过这种方式，挑选出位置稳定的回波，作为真正的回波脉冲，进而根据该真正的回波，可以得到实际障碍物的距离信息。
继续参考图5a，虽然通道1、2、3、4为并行发光，但是彼此之间还是有一定的相对前后时序，即，在第一探测方位，通道1、2、3、4的发光时刻依次递减地更晚；在第二探测方位，通道1、2、3、4仍然为并行发光的通道，但彼此之间的相对前后时序与其在第一探测方位时不同，即，在第二探测方位，通道1、2、3、4依次发光时序递增地更早。
根据本发明的一个优选实施例，其中步骤S16包括：根据时间匹配度，确定所述一个通道在所述第一探测方位和第二探测方位时位置重合的回波脉冲。
在调整发光相对前后的时序后，第一探测方位与第二探测方位的发光时序不同，因而串扰的时间位置也不同，如果两个探测方位的测距结果是连续的，根据时间进行匹配并通过脉冲滤波，可以挑选出位置稳定的有效回波脉冲。换言之，本申请背后的逻辑是：通过调整并行发光通道在2次水平探测方位上相对前后的发光时序，打乱串扰信号(来自并行发光的其它通道)在待测通道接收到的回波中出现的位置，让串扰变得随机，同时默认待测通道在相邻2次水平探测方位上的测距结果是连续的(对任意1个通道，在水平角度θi的测距结果di＝在水平角度θi+1的测距结果di+1)，也就意味着真正的外界障碍物对应的回波在接收到的回波信号中出现的位置是固定的，故通过将2次水平探测方位的发光脉冲时间上挪到一致，且让回波脉冲挪同样的大小后，比较2个回波脉冲，就可以挑出在该2个回波脉冲中位置稳定的回波脉冲，以作为外界障碍物产生的真正的回波脉冲，进而采用该真正的回波脉冲，计算外界障碍物的如距离或者反射率等信息。
以下通过优选实施例进一步详述。
根据本发明的一个优选实施例，其中步骤S16包括：对于该组通道内的一个通道，相对平移所述一个通道在第一探测方位和第二探测方位的测距脉冲的发射时间至重合，比对两次的测距结果，选出位置稳定的回波脉冲。其 中，对于一个通道的回波进行滑窗操作，即相对平移该通道在第一探测方位和第二探测方位的测距脉冲使他们的发射时间重合，后续段落将配合实施例对滑窗操作以及滑窗范围进行介绍。
图5b示出了对图5a中的通道1进行滑窗处理的示意图，图5c示出了图5a中的2个探测方位的探测和滑窗方式的示意图，结合图5a-5c可见，相对平移第一探测方位和第二探测方位的测距脉冲A的发射位置至重合，进而对比在第一探测方位和第二探测方位测到的脉冲结果，从中滤波和挑选出位置稳定的那个脉冲，作为第一探测方位下有效的或者真正的回波脉冲，进而采用有效回波脉冲经过处理后，计算出通道1的测距信息。具体地，相对平移第一探测方位和第二探测方位的测距脉冲A的发射位置至重合后，对比在第一探测方位和第二探测方位测到的测距回波脉冲A’，测距回波脉冲A’的位置确定，前沿没有与串扰脉冲B’、C’、D’重合，可以作为第一探测方位和/或第二探测方位的有效回波脉冲。
根据本发明的一个优选实施例，其中在步骤S13和S15中，通过该组通道的探测器22分别接收测距脉冲自物体反射的测距回波脉冲，步骤S16包括：对于该组通道内的一个通道，相对平移所述一个通道在第一探测方位和第二探测方位的测距脉冲的发射时间至重合，在时间上相互错开的测距回波脉冲为位置稳定的回波脉冲。
继续参考图5b，在第一探测方位和第二探测方位，测距回波脉冲A’与通道1接收到的其它串扰B’、串扰C’以及串扰D’刚好错开一个脉冲宽度，这是一种比较理想的情况。在发射脉冲时，可以通过调整发光时序，使得测距回波脉冲A’与串扰B’、串扰C’以及串扰D’尽量不交叠，这样测距回波脉冲A’的位置稳定，可以作为在第一探测方位的有效回波脉冲。
为了在回波脉冲与串扰至少部分重叠的情形下，提高确定真正回波的效率，步骤S11还包括：确定该组通道的激光器21在第二探测方位之后的至少一个其他探测方位的发光时序，其中在至少一个其他探测方位的发光时序不同于第一发光时序和第二发光时序，步骤S16包括：对于该组通道内的一个通道，对一个通道在第一探测方位、第二探测方位以及至少一个其他探测方 位的回波信号做如图5a-5c所示的滑窗处理，确定位置稳定的回波脉冲，作为所述一个通道在第一探测方位和/或第二探测方位的有效回波脉冲。原理是如果对多个探测方位设置不同的发光时序，即使出现测距回波脉冲与串扰叠加，经过尽量多个不同的探测方位上的回波信号进行滑窗处理，在某些探测方位上，串扰信号与真正的回波总会有一定的错开，这样最终也可以找到真正的回波信号。例如，对并行发光的n个通道设置m种相对的发光时序，分别在m个探测方位(可以是水平角度θi-θi+m)按照m种发光时序并行发光，然后把同一个通道在这些采用了不同发光时序所得到的探测回波信号进行滑窗处理，可以在测距回波脉冲与串扰叠加时仍找到真正的回波信号，提高测距的精准度。
根据本发明的一个优选实施例，其中第一探测方位和第二探测方位以及至少一个其他探测方位的时间差在预设时间范围内。该预设时间范围应保证第一探测方位和第二探测方位以及至少一个其他探测方位的测距结果是连续的，亦即，对任意一个通道，在第一探测方位的测距结果＝在第二探测方位的测距结果＝在至少一个其他探测方位的测距结果。该预设时间范围与雷达的转速相关，雷达的转速越快，该时间范围可以设置的越宽，抗干扰效果越强，越容易挑选出真正的测距回波脉冲。优选地，将该预设时间范围设置为水平角分辨率对应的时间间隔的倍数。
在多个探测方位进行滑窗处理包括：对于一个通道，相对平移该通道在第一探测方位和第二探测方位以及至少一个其他探测方位的测距脉冲的发射时间至重合。以下通过实施例对滑窗范围进行介绍。
图6a示出了本发明一个实施例的第一种滑窗范围示意图，其中第一探测方位对应水平视场角θi，第二探测方位对应水平视场角θi+1，第三探测方位对应水平视场角θi+2，例如，对于一组通道，分别获取该组通道在水平视场角θi、水平视场角θi+1以及水平视场角θi+2的测距结果；对于其中一个通道，相对平移该通道在水平视场角θi、水平视场角θi+1以及水平视场角θi+2的测距脉冲的发射时间至重合，比对三次的测距结果，选出位置稳定的回波脉冲。其中，水平视场角θi、水平视场角θi+1以及水平视场角θi+2的时间差在预设 时间范围内。
图6b示出了本发明一个实施例的第二种滑窗范围示意图，其中第一探测方位对应水平视场角θi，第二探测方位对应水平视场角θi+1，第三探测方位对应水平视场角θi+2，第四探测方位对应水平视场角θi+3，第五探测方位对应水平视场角θi+4。例如，对于一组通道，分别获取该组通道在水平视场角θi、水平视场角θi+1、水平视场角θi+2、水平视场角θi+3以及水平视场角θi+4的测距结果；对于其中一个通道，相对平移该通道在水平视场角θi、水平视场角θi+1、水平视场角θi+2、水平视场角θi+3以及水平视场角θi+4的测距脉冲的发射时间至重合，比对五次的测距结果，选出位置稳定的回波脉冲。其中，水平视场角θi、水平视场角θi+1、水平视场角θi+2、水平视场角θi+3以及水平视场角θi+4的时间差在预设时间范围内。
滑窗范围越大，能选出位置稳定的测距回波脉冲的概率越高，但耗费时间和计算量，需要在滑窗范围和测距精度之间平衡。
根据本发明的一个优选实施例，其中步骤S16还包括：根据至少一个第二通道在第一探测方位和第二探测方位时的回波脉冲，确定所述一个通道在第一探测方位和第二探测方位时位置稳定的回波脉冲。在该实施例中，通过调整在不同探测方位的发光时序，使得一组通道内的干扰以及至少一个第二通道对该组通道内的干扰变得随机，进而通过滑窗和脉冲滤波，挑出位置稳定的、真正的测距回波脉冲。
图6c示出了本发明一个实施例的第三种滑窗范围示意图，其中第一探测方位对应水平视场角θi，第二探测方位对应水平视场角θi+1，第三探测方位对应水平视场角θi+2，其中包括两个第二通道，分别为CH-1和CH-2，CH-1对应上一垂直通道，第二通道CH-2对应下一垂直通道。其中，垂直通道包括竖直方向上的、已经完成测量的相邻的通道或者相对靠上的通道(参考图2a)。例如，对于一组通道，分别获取该组通道在水平视场角θi、水平视场角θi+1以及水平视场角θi+2的测距结果，以及该组通道的上一垂直通道和下一垂直通道在水平视场角θi+1时的测距结果；对于其中一个通道，相对平移该通道在水平视场角θi、水平视场角θi+1以及水平视场角θi+2的测距脉冲的发射时 间至重合，比对上述测距结果，选出位置稳定的测距回波脉冲。其中，水平视场角θi、水平视场角θi+1以及水平视场角θi+2的时间差在预设时间范围内。
图6d示出了本发明一个实施例的第四种滑窗范围示意图，其中第一探测方位对应水平视场角θi，第二探测方位对应水平视场角θi+1，第三探测方位对应水平视场角θi+2，第二通道CH-1对应上一垂直通道，第二通道CH-2对应下一垂直通道。例如，对于一组通道，分别获取该组通道在水平视场角θi、水平视场角θi+1以及水平视场角θi+2的测距结果，以及该组通道的上一垂直通道和下一垂直通道在水平视场角θi+1、水平视场角θi+1以及水平视场角θi+2时的测距结果；对于其中一个通道，相对平移该通道在水平视场角θi、水平视场角θi+1以及水平视场角θi+2的测距脉冲的发射时间至重合，比对上述测距结果，选出位置稳定的测距回波脉冲。其中，水平视场角θi、水平视场角θi+1以及水平视场角θi+2的时间差在预设时间范围内。
以上通过四个实施例对滑窗范围进行介绍，通过时间维度和空间维度的滑窗处理，挑选出真正的测距回波脉冲，即可以作为第一探测方位的有效回波脉冲，也可以作为第二探测方位的有效回波脉冲，进而在一定程度上降低数据运算量。
根据本发明的一个优选实施例，其中所述步骤S16包括：当所述一个通道在第一探测方位和第二探测方位时位置稳定的回波脉冲的幅值的差值或比值超过预设阈值时，将稳定的回波脉冲作为一个通道在第一探测方位和/或第二探测方位的有效回波脉冲。
如果第一探测方位和第二探测方位的测距结果是连续的，亦即，对任意一个通道，在第一探测方位的测距结果＝在第二探测方位的测距结果，通过多维度滑窗和脉冲滤波可以挑选出有效回波脉冲；如果第一探测方位和第二探测方位的测距结果是不连续的，则无需进行滑窗和脉冲滤波的操作。
图7示出了本发明一个实施例的第一探测方位和第二探测方位测距结果对比图，对于通道1，激光器21在第一探测方位发射的测距脉冲与其在第二探测方位发射的测距脉冲的大小相同；对应的探测器22在第一探测方位接收的测距回波脉冲远远大于其在第二探测方位接收的测距回波脉冲，此时在第 一探测方位的测距结果≠在第二探测方位的测距结果，无需执行滑窗和滤波的操作。其中，在第一探测方位接收的测距回波脉冲与在第二探测方位接收的测距回波脉冲的幅值比值例如≥80％，此处仅为示例性说明，也可以通过对不同探测方位之间的测距回波脉冲的幅值差值设置阈值。
综上所述，通过步骤S10-S16以及多个优选实施例对控制方法10进行了介绍，通过调整并发光通道在一定时间范围内的相对发光前后时序并结合多维度滑窗和滤波，降低并行发光通道之间的串扰，提高信噪比以及测距的精准度。以上对不同发光时序的选取较为随机，方法简单，兼顾数据运算量以及测距精准度，以下通过另一优选实施例对发光时序进行编码，使得并行发光的多个通道的测距结果都是最为理想的完全不重叠的结果，使得测距精度可控。此外，本说明书提供了如实施例或流程图所述的方法操作步骤，但基于常规或者无创造性的劳动可以包括更多或者更少的操作步骤。实施例中列举的步骤顺序仅仅为众多步骤执行顺序中的一种方式，不代表唯一的执行顺序。在实际中的系统或设备产品执行时，可以按照实施例或者流程图所示的方法顺序执行或者并行执行。
为了尽量让真正的回波和串扰信号不要出现重叠的情况，可以对并行发光通道的发光时序进行提前编码，具体的编码方法，将结合图8-图13进行详细介绍。以下介绍时，与上述相同的步骤不再赘述，仅对改进的步骤以及发光时序的编码方法进行介绍。
多通道并行发光时，通道之间容易产生串扰，因此可以通过编码设置以消除或者减轻串扰。通常激光雷达20为了完成一次探测(生成点云中的一个点)，可以控制激光器21发射两个脉冲或更多脉冲。参考图8，以3脉冲为例，激光器21发出第一个探测脉冲p1后，间隔code1的时间后发出第二个探测脉冲p2，然后再间隔code2的时间后发出第三个脉冲p3。对于双脉冲而言，则是激光器21发出第一个探测脉冲p1后，间隔code1的时间后发出第二个探测脉冲p2。并行发光的通道，可以设置不同大小的code1。上述为多脉冲P1、P2和P3设置特定的间隔时间code1和code2，为编码的其中一种方式。
对于激光雷达20，当激光器21以code1和code2为间隔发射三个探测脉冲P1、P2和P3之后，从接收的脉冲组(可能有多个脉冲，比如超过3个的脉冲)中识别出彼此间隔为code1及code2的3个脉冲时，此时可以认为本次发光测量探测到了物体。如果未识别出彼此间隔为code1及code2的3个脉冲，则认为本次发光测量未探测到物体。这种识别方式比较精准，可以尽量减少噪点，但计算量太大，且容易丢点。
图9示出了理想情况下两个通道的探测过程，两个通道之间不具有电串扰和光串扰，或者已经消除了电串扰和光串扰。如图9所示，channel1发射的脉冲探测到物体a，channel2发射的脉冲探测到物体b，当channel1和channel2通道之间没有光串扰或电串扰时，各通道仅接收到自己通道对应的物体的反射回波脉冲，则物体a的测距结果一般依据回波波形的特征计算得出，根据计算结果能够准确获得物体a的距离。
图10示出了两个通道之间存在串扰的情形。channel1发射的脉冲探测到物体a，channel2发射的脉冲探测到物体b。channel1发射出三个探测脉冲Pa1、Pa2和Pa3，对应地收到三个回波脉冲Ea1、Ea2和Ea3；channel2发射出三个探测脉冲Pb1、Pb2和Pb3，对应地收到三个回波脉冲Eb1、Eb2和Eb3。当channel1和channel2通道之间有串扰时，channel2的三个回波脉冲会分别在通道1上产生串扰，如图10中的串扰回波脉冲Eb1'、Eb2'和Eb3'。由于channel1和channel2的回波脉冲在时间轴上具有一定的重合度，因此串扰回波脉冲Eb1'、Eb2'和Eb3'分别叠加在channel1的回波脉冲Ea1、Ea2和Ea3上，会导致回波脉冲Ea1、Ea2和Ea3的波形发生变化，在图10所示的情形中，最终获得的回波到达时间将会不准确，进而导致距离结果不准确，比如有一种可能性是导致物体a的距离被计算为da'，而非真实值da。因此在图10的情形中，channel1因为串扰而接收到物体a的回波+物体b(实际应该出现在对应channel2的方位上)的回波(对channel1的方向来说，其实并不存在物体b)时，这样一来，物体a的回波脉冲可能会与串扰回波脉冲进行叠加，导致物体a的回波波形的特征发生变化。此时物体a的测距结果同样由前沿+脉宽计算，但与没有串扰时的结果会有一定的偏差， 偏差程度取决于前沿和脉宽的偏差程度。
用Wtof表示总飞行时间窗口，Wtof与激光雷达20的最远探测距离dmax有关，dmax的具体数值对于每款激光雷达20可能均不相同。为了完成一次测距(生成点云中的一个点)，激光雷达20可发射单脉冲，也可以发射多脉冲。对于激光雷达20发射单脉冲的情况，可以设置总飞行时间窗口Wtof≈dmax(在激光雷达领域，距离通常可与时间互相换算及对应，因此在这里用距离来表示时间窗口，更精确的表达为：Wtof＝2*dmax/c，其中c为光速。然而为了简洁起见，下文仍用Wtof≈dmax的表达方式，本领域技术人员能够清楚理解其含义)。参考图11a，如果激光雷达20发射双脉冲P1和P2，则脉冲间隔为code1；如果激光雷达20发射3脉冲P1、P2和P3，则脉冲间隔分别为code1和code2；如果激光雷达20发射4脉冲P1、P2、P3和P4，则脉冲间隔分别为code1、code2和code3。如果每个通道发射多脉冲，在计算总飞行时间窗口Wtof时，还要考虑让多脉冲的最后1个脉冲也要能在该总飞行时间窗口Wtof内被接收到，因此最后1个脉冲从dmax处返回的时刻也要在总的飞行时间窗口内。参考图11b，以发射双脉冲为例，则总飞行时间窗口(或者称为探测窗口)Wtof＝dmax+code1。同理，如果发射3个脉冲，则可以设置总飞行时间窗口Wtof≈dmax+code1+code2；发射4个脉冲时，可以设置总飞行时间窗口Wtof≈dmax+code1+code2+code3。本领域技术人员可以理解，该公式并非雷达中计算总飞行时间窗口的精准方式，实际中还要考虑激光器21的充电时间和脉冲的宽度等。此处仅为示例性说明，本发明并不对总飞行时间窗口的具体计算方法做限定。
测距脉冲是用来计算飞行时间ToF的脉冲。如果激光雷达20发射单脉冲，那么该单脉冲即为测距脉冲，飞行时间的计算以激光器21发射测距脉冲为计时的开始时刻，以探测器22接收到测距脉冲在物体上反射的测距回波脉冲为计时的结束时刻。如果激光雷达20发射多脉冲，那么可以从多脉冲中选择一个或多个脉冲作为测距脉冲。例如，参考图11b，激光器21发射双脉冲，如果将第一个脉冲作为测距脉冲，则发射测距脉冲的时刻为tstart1，探测器22接收到该测距脉冲对应的测距回波脉冲的时刻为tstop1，则飞行时间为tstop1- tstart1。本领域技术人员可以理解，该公式并非激光雷达中计算飞行时间的精准方式，实际中对于发射端可能存在偏移量offset(比如考虑到激光器的温漂、激光器的响应等)的补偿；对于接收端，为了提高信噪比，会涉及接收信号阈值threshold的设置，例如以接收回波脉冲的强度大于阈值的时间点作为计时的结束时刻。此处仅为示例性说明，本发明并不对飞行时间的具体计算方法做限定。
以下继续对优选实施例进行介绍。
根据本发明的一个优选实施例，其中步骤S11包括：
通过以下方式确定第一发光时序和第二发光时序：根据该组通道中每个通道之前的测距结果、与该通道邻近的通道之前的测距结果以及障碍物信息中的一项或多项，确定第一发光时序和第二发光时序，第一发光时序和第二发光时序配置成使得：第一组回波脉冲和第二组回波脉冲在时间上相互错开。
根据该组通道中每个通道以及与该通道邻近的通道之前的测距结果以及障碍物信息，预测待发出的测距脉冲对应的测距回波脉冲的时间，确定第一发光时序和第二发光时序。例如，根据该组通道中每个通道和其相邻通道在水平视场角θi-1的测距结果，预测该通道在水平视场角θi及θi+1的测距结果，基于该预测结果设置第一发光时序和第二发光时序。又例如，根据该组通道中每个通道在相邻2次的水平视场角θi-2及θi-1测到的距离，预测该通道水平视场角θi及θi+1探测到的距离，基于该预测结果设置第一发光时序和第二发光时序。再例如，结合物体识别(例如物体是否为静态障碍物、慢速障碍物或者快速移动的障碍物)以及距离预测等技术，综合之前的测距结果，预测待发出的测距脉冲的测距结果，基于该预测结果对第一发光时序和第二发光时序进行设置。
需要说明的是，采用以上任意一种或者多种的方式，设置待进行探测的激光器21的发光时序的目的，均是为了实现至少部分的并行发光的通道的测距脉冲相互错开，最好是该组通道中每个并行发光通道的测距脉冲都错开。而具体错开的程度，以后续的处理器能区分自身通道的测距回波脉冲及干扰脉冲，进而不影响该通道的测距精度为标准。
以上通过优选实施例说明基于之前的测距结果设置第一发光时序和第二发光时序，由此可见，之前的测距结果的准确度直接影响到发光时序的设置以及测距回波脉冲相互错开的效果。以下通过优选实施例进一步描述如何提高测距结果的准确度。
根据本发明的一个优选实施例，在多通道并行发光的情况下，若各通道发射多脉冲，可以在多个脉冲中选择至少两个脉冲作为测距脉冲，基于至少两个测距脉冲获取测距结果，从而会降低信号串扰的影响，提高测距结果的准确度。
根据本发明的一个优选实施例，在选择多个测距脉冲时，可以根据多个测距脉冲以及相对应的多个测距回波脉冲分别计算多个距离，进而根据所述多个测距脉冲的预设权重，对所述多个距离加权计算得出测距结果，可以降低串扰对测距的影响，提高测距精准度。例如，如果发射4个脉冲，参考图11a，4个脉冲分别是P1、P2、P3及P4，可以选择将P1-P4都作为测距脉冲，最终的测距结果d＝(dP1+dP2+dP3+dP4)/4；也可以选择将P2-P4都作为测距脉冲，最终的测距结果d＝(dP2+dP3+dP4)/3。
在上面这2个实施例中，每个脉冲对最终测距结果d的贡献的权重相同，均为1。也可以按照不同的权重加以考虑。例如，给每个脉冲分配不同的权重Xi，1＞Xi＞0。比如选择将P1-P4都作为测距脉冲，最终的测距结果
d＝XP1*dP1+XP2*dP2+xP3*dP3+XP4*dP4，其中，XP1+XP2+XP3+XP4＝1。
以上通过实施例对如何提高测距结果的准确度进行了说明，基于之前的测距结果，为了将并行发光的每个通道的测距回波脉冲相互错开，可以预先把总飞行时间窗口进行区间划分，然后为每个测距回波脉冲分配尚未被标记和未被占用的区间，可以更加精确地控制测距回波脉冲的位置，以下将通过优选实施例进一步介绍。
根据本发明的一个优选实施例，控制方法10还包括：将该组通道的激光器的总飞行时间窗口至少分为第一区间和第二区间，其中第一发光时序配置成使得：第一组回波脉冲不重合地分布在第二区间内，第二发光时序配置成使得：第二组回波脉冲与第一组回波脉冲不重合地分布在第二区间内。
图12a示出了本发明一个实施例的总飞行时间窗口划分示意图，将总飞行时间窗口划分为两个区间，其中第一区间用于放置测距回波脉冲前面的其他脉冲，第二区间用于放置各个通道的测距回波脉冲。预测每个组的多个通道的激光器21待发射的测距脉冲分别产生的至少部分测距回波脉冲的时间。基于各通道或其邻近通道之前的测距结果，预测待发射的测距脉冲对应的测距回波脉冲的时间；接着，设置该组通道的第一发光时序和第二发光时序，使得至少部分并行发光的多个通道的激光器21发射测距脉冲后，产生的测距回波脉冲不重合地(不重合的程度，每个雷达可能会不同，以后续的处理器能够分辨本通道的测距回波脉冲和串扰脉冲，不影响本通道的测距精准度为准)分布在第二区间内。其中，测距回波脉冲不重合包括各测距回波脉冲在时间上相互错开、相互分开、不交叠、间隔开来、落在不同位置等。
根据本发明的另一个优选实施例，控制方法10还包括：将第二区间分为k个子区间，其中k为整数并且大于等于该组内通道的数目，其中第一发光时序配置成使得：第一组回波脉冲不重合地分布在k个子区间内；第二发光时序配置成使得：第二组回波脉冲与第一组回波脉冲不重合地分布在k个子区间内。
图12b示出了本发明另一个实施例的总飞行时间窗口划分示意图，将总飞行时间窗口分为k+1个子区间，分别为G0、G1、G2、…、Gk，其中G0相当于第一区间，用于放置最先接收到的测距回波脉冲前面的其他脉冲；G1-Gk用于放置测距回波脉冲，其中G1相当于理论上存在的用来放置测距回波脉冲的第1个子区间，理想情况下，最先接收到的测距回波脉冲前面的非测距脉冲都集中在G0内，而不要出现在G1-Gk内。具体到某个通道，该通道的障碍物越近，测距回波脉冲的飞行时间越短，因此可以用来放置测距回波脉冲的子区间越多；该通道的障碍物越远，测距回波脉冲的飞行时间越长，因此可以用来放置测距回波脉冲的子区间越少。
根据本发明的一个优选实施例，其中每个子区间的长度大于激光雷达的测距回波脉冲的最大脉宽。参考图12a和12b，对于子区间G1～Gk，每个区间的长度假设为G，G大于测距回波脉冲的最大脉宽，以保证每个子区间能够放 置一个测距回波脉冲。优选地，G≥2倍脉宽。每款激光雷达的脉宽可能不同。当最大脉冲的宽度约为30ns时，G优选为60ns以上。
结合图12a和12b,第一区间(亦即G0区间)的长度划分原则是在最小的测距距离上能够放置测距回波脉冲前面的其它脉冲。G0的时间窗口长度为(Wtof-k*G)，G1是理论上可用来放置测距回波脉冲的第1个子区间，尽量希望非测距回波脉冲都集中在GO内，而不要出现在子区间G1～Gk，使得子区间G1～Gk可以用来放置各个通道的测距回波脉冲。
例如，以激光器21发射3脉冲并选择第3个脉冲作为测距脉冲为例，则G0区间的长度优选为在最小的测距距离上能够放置第1个回波脉冲和第2个回波脉冲，那么可以设置G0≈dmin+code1+code2，其中dmin是雷达可测的最小距离。这样G1的区间大约就是[dmin+code1+code2，dmin+code1+code2+G]，因此G1相当于是一个理论的、用来放置测距回波脉冲(在此实施例中，即第3个脉冲的回波脉冲)的第1个子区间。
而G1＝G2＝....＝Gk-1＝Gk＝G，k至少要大于等于并行发光的通道数量。优选地，k大于并行发光的通道数量。因为要确保并行发光的各个通道的测距回波脉冲独占一个子区间，亦即，不重合的分布在子区间G1～Gk内，并且还要考虑到对于障碍物比较远的通道，其非测距脉冲可能也会占用一些子区间。因此，为了进一步减少其它通道的测距回波脉冲和非测距回波脉冲对该通道的干扰，根据本发明的一个优选实施例，其中所述第一发光时序和第二发光时序还可以进一步配置成使得：每个通道的激光器21发射的测距脉冲产生的至少部分测距回波脉冲与该组中其他通道的激光器21发射的非测距脉冲产生的非测距回波脉冲不重合。
根据本发明的一个优选实施例，其中所述第一发光时序配置成使得：所述第一组回波脉冲分布在所述k个子区间中未被占用并且距离最近的子区间内；所述第二发光时序配置成使得：所述第二组回波脉冲分布在所述k个子区间中未被占用并且距离最近的子区间内。将各个测距回波脉冲放置于未被占用的子区间，可以避免串扰对测距结果的影响。更进一步地，将各个测距回波脉冲尽可能的放置于距离最近的子区间，缩短测量时长，提高测量效率。 以下将通过实施例具体描述发光时序的编码方法。
根据本发明的一个实施例，一组4个通道(Channel 1、Channel 2、Channel 3和Channel 4)的激光器21并行发光，每个通道的激光器21发射3个脉冲，其中第3个脉冲为测距脉冲。参考图12b，总飞行时间窗口划分为G0、G1-Gk的子区间，其中G1-Gk子区间的中点位置为g1-gk。参考图14，每个通道发射3个脉冲，第1个脉冲和第2个脉冲的时间间隔为code1，第2个脉冲和第3个脉冲的时间间隔为code2。为方便描述，将code1设为固定值，但是本领域技术人员可以理解，为了防止其他雷达的串扰，code1也可以设置不同值，亦即对脉冲间隔进行编码；
定义脉冲间隔code1和code2的最小值为Cmin，Cmin与发射通道的激光器充电电路的处理速度相关。本实施例中，可以设置Cmin≥脉宽/2，以更准确地区分出相邻的2个脉冲。
进行上述设置后，根据控制方法10，首先获得之前的测距结果。4个通道Channel 1、Channel 2、Channel 3和Channel 4并行发光，在水平视场角θi-1的测距结果分别为d1、d2、d3和d4。
然后根据之前的测距结果预测4个通道Channel 1、Channel 2、Channel 3和Channel 4在水平视场角θi的测距回波脉冲的位置(时刻)，并基于预测的测距回波脉冲的位置设置第一发光时序，亦即对θi角度下的发光脉冲的code2进行编码。具体地，在发光前进行以下步骤：
1.任选一个尚未计算code2的通道Channel x，其中x∈(1,2,3,4)，其在水平视场角θi-1角度的测距结果为dx；
2.从尚未被标记的G1～Gk子区间中选取距离最近的子区间Gy，并且子区间Gy的中点位置为gy；
3.判断选择的子区间Gy是否满足公式：gy-dx–code1≥Cmin；
3.1.如果gy-dx–code1≥Cmin，则Channel x的code2设置为gy-dx–c1，同时将子区间Gy标记。另外，还需判断第1脉冲和第2个脉冲是否占据了G1～Gy之间的其他子区间？若占据了，也将该子区间标记，该子区间就不会被分配给其他测距脉冲。
3.2.如果gy-dx–code1＜Cmin，说明该子区间Gy虽然尚未被标记，但不适合用于通道Channel x，则从尚未被标记的Gy+1～Gk子区间中选取距离最近的子区间Gz，重新进行第3步的判断。
3.3.如果从尚未被标记的子区间中无法找到满足条件的子区间，则选取子区间Gk，则Channel x的code2设置为gk-dx–code1。
4.继续执行第1-3步，直到接下来要并行发光的所有通道的code2都计算选择完毕。
通过以上步骤设置在水平视场角θi的4个通道的第一发光时序后，控制4个通道的激光器21根据第一发光时序进行发光。如图13所示，通过这样的方式，并行发光的4个通道所产生的测距回波脉冲在时间上相互错开，减轻或者避免了串扰问题。需要说明的是，图14中各通道的接收端仅示出测距回波脉冲，为避免混乱，未示出非测距回波脉冲。
第二发光时序的编码方法同上设置，此处不再赘述。
此外，需要说明的是，在物体距离较远时，假设极端情况下并行发光的每个通道在θi角度测量的物体都在最远处，则为了保证能够测到点，每个通道的测距回波脉冲都会被划分到Gk区间。但是物体距离越远，串扰越弱(障碍物离得远，每个通道的回波都很微弱，对彼此的串扰也很弱小)，且远处的测距精准度要求更低，因此也能够满足测距要求。
本发明还涉及一种计算机存储介质，包括存储于其上的计算机可执行指令，所述可执行指令在被处理器执行时实施如上所述的控制方法10。
本发明还涉及一种激光雷达20，如图14所示，包括：
多个激光器21，例如激光器21-1、……、激光器21-n，每个激光器21发射的脉冲中至少一个脉冲作为测距脉冲；
多个探测器22，例如探测器22-1、……、探测器22-n，所述多个激光器21和所述多个探测器22构成多个通道，每个通道包括至少一个激光器21和至少一个探测器22；
控制装置23，所述控制装置23与所述多个激光器21和所述多个探测器22连接，将所述多个通道分为多组，每组通道并行发光，所述控制装置23 配置成：
对于其中一组通道，确定该组通道的激光器21的发光时序，其中在第一探测方位所用的第一发光时序和在第二探测方位所用的第二发光时序不同；
在所述第一探测方位，控制该组通道的激光器21按照所述第一发光时序发射第一组探测脉冲；
通过该组通道的探测器22分别接收所述第一组探测脉冲自物体反射的第一组回波脉冲；
在所述第二探测方位，控制该组通道的激光器21按照所述第二发光时序发射第二组探测脉冲；
通过该组通道的探测器22分别接收所述第二组探测脉冲自物体反射的第二组回波脉冲；
对于该组通道内的一个通道，确定所述一个通道在所述第一探测方位和第二探测方位时位置稳定的回波脉冲，作为所述一个通道在所述第一探测方位和/或第二探测方位的有效回波脉冲。
根据本发明的一个优选实施例，其中所述第一发光时序和第二发光时序中，该组通道的至少部分激光器21不同时发光。
根据本发明的一个优选实施例，其中该组通道中每个通道的探测器22接收的回波脉冲包括有效回波脉冲和由其他通道产生的串扰，所述控制装置23配置成：根据时间匹配度，确定所述一个通道在所述第一探测方位和第二探测方位时位置重合的回波脉冲。
根据本发明的一个优选实施例，其中该组通道的激光器21发射的脉冲中至少一个脉冲作为测距脉冲，所述控制装置23配置成：对于该组通道内的一个通道，相对平移所述一个通道在所述第一探测方位和第二探测方位的测距脉冲的发射时间至重合，比对两次的测距结果，选出位置稳定的回波脉冲。
根据本发明的一个优选实施例，其中通过该组通道的探测器22分别接收所述测距脉冲自物体反射的测距回波脉冲，所述控制装置23配置成：对于该组通道内的一个通道，相对平移所述一个通道在所述第一探测方位和第二探测方位的测距脉冲的发射时间至重合，在时间上相互错开的测距回波脉冲为 位置稳定的回波脉冲。
根据本发明的一个优选实施例，其中所述控制装置23配置成：确定该组通道的激光器21在第二探测方位之后的至少一个其他探测方位的发光时序，其中所述在至少一个其他探测方位的发光时序不同于所述第一发光时序和第二发光时序，所述控制装置23还配置成：对于该组通道内的一个通道，确定所述一个通道在所述第一探测方位、第二探测方位以及至少一个其他探测方位时位置稳定的回波脉冲，作为所述一个通道在所述第一探测方位和/或第二探测方位的有效回波脉冲。
根据本发明的一个优选实施例，其中所述第一探测方位和所述第二探测方位以及所述至少一个其他探测方位的时间差在预设时间范围内。
根据本发明的一个优选实施例，其中所述控制装置23还配置成：根据至少一个第二通道在所述第一探测方位和第二探测方位时的回波脉冲，确定所述一个通道在所述第一探测方位和第二探测方位时位置稳定的回波脉冲。
根据本发明的一个优选实施例，其中所述控制装置23还配置成：当所述一个通道在所述第一探测方位和第二探测方位时位置稳定的回波脉冲的幅值的差值或比值超过预设阈值时，将所述稳定的回波脉冲作为所述一个通道在所述第一探测方位和/或第二探测方位的有效回波脉冲。
根据本发明的一个优选实施例，其中所述控制装置23还配置成：通过以下方式确定所述第一发光时序和第二发光时序：根据该组通道中每个通道之前的测距结果、与该通道邻近的通道之前的测距结果以及障碍物信息中的一项或多项，确定所述第一发光时序和第二发光时序，所述第一发光时序和第二发光时序配置成使得：第一组回波脉冲和第二组回波脉冲在时间上相互错开。
根据本发明的一个优选实施例，其中所述控制装置23还配置成：将该组通道的激光器21的总飞行时间窗口至少分为第一区间和第二区间，其中所述第一发光时序配置成使得：第一组回波脉冲不重合地分布在所述第二区间内，所述第二发光时序配置成使得：第二组回波脉冲与所述第一组回波脉冲不重合地分布在所述第二区间内。
根据本发明的一个优选实施例，其中所述控制装置23还配置成：将所述第二区间分为k个子区间，其中k为整数并且大于等于该组内通道的数目，其中所述第一发光时序配置成使得：第一组回波脉冲不重合地分布在所述k个子区间内；所述第二发光时序配置成使得：第二组回波脉冲与所述第一组回波脉冲不重合地分布在所述k个子区间内。
根据本发明的一个优选实施例，其中所述每个子区间的长度大于所述回波脉冲的最大脉宽。
根据本发明的一个优选实施例，其中所述控制装置23还配置成：所述第一发光时序配置成使得：所述第一组回波脉冲分布在所述k个子区间中未被占用并且距离最近的子区间内；所述第二发光时序配置成使得：所述第二组回波脉冲分布在所述k个子区间中未被占用并且距离最近的子区间内。
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 (29)

  1. 一种激光雷达的控制方法，所述激光雷达包括多个通道，每个通道包括至少一个激光器和至少一个探测器，所述控制方法包括：
    S11：将所述多个通道分为多组，每个组的所有通道并行发光，对于其中一组通道，确定该组通道的激光器的发光时序，其中在第一探测方位所用的第一发光时序和在第二探测方位所用的第二发光时序不同；
    S12：在所述第一探测方位，控制该组通道的激光器按照所述第一发光时序发射第一组探测脉冲；
    S13：通过该组通道的探测器分别接收所述第一组探测脉冲自物体反射的第一组回波脉冲；
    S14：在所述第二探测方位，控制该组通道的激光器按照所述第二发光时序发射第二组探测脉冲；
    S15：通过该组通道的探测器分别接收所述第二组探测脉冲自物体反射的第二组回波脉冲；
    S16：对于该组通道内的一个通道，根据所述一个通道的第一组回波脉冲和第二组回波脉冲，确定所述一个通道的有效回波脉冲。
  2. 根据权利要求1所述的控制方法，其中所述第一发光时序和第二发光时序中，该组通道的至少部分激光器不同时发光。
  3. 根据权利要求1所述的控制方法，其中在步骤S13和S15中，该组通道中每个通道的探测器接收的回波脉冲包括有效回波脉冲和由其他通道产生的串扰，所述步骤S16包括：根据时间匹配度，确定所述一个通道在所述第一探测方位和第二探测方位时重合的回波脉冲。
  4. 根据权利要求1-3中任一项所述的控制方法，其中在步骤S12和S14中，该组通道的激光器发射的脉冲中至少一个脉冲作为测距脉冲，所述步骤S16包括：对于该组通道内的一个通道，相对平移所述一个通道在所述第一探测 方位和第二探测方位的测距脉冲的发射时间至重合，比对两次的测距结果，选出位置稳定的回波脉冲。
  5. 根据权利要求4所述的控制方法，其中在步骤S13和S15中，通过该组通道的探测器分别接收所述测距脉冲自物体反射的测距回波脉冲，所述步骤S16包括：对于该组通道内的一个通道，相对平移所述一个通道在所述第一探测方位和第二探测方位的测距脉冲的发射时间至重合，在时间上相互错开的测距回波脉冲为位置稳定的回波脉冲。
  6. 根据权利要求1-3中任一项所述的控制方法，其中所述步骤S11还包括：确定该组通道的激光器在第二探测方位之后的至少一个其他探测方位的发光时序，其中所述在至少一个其他探测方位的发光时序不同于所述第一发光时序和第二发光时序，所述步骤S16包括：对于该组通道内的一个通道，确定所述一个通道在所述第一探测方位、第二探测方位以及至少一个其他探测方位时位置稳定的回波脉冲，作为所述一个通道在所述第一探测方位和/或第二探测方位的有效回波脉冲。
  7. 根据权利要求6所述的控制方法，其中所述第一探测方位和所述第二探测方位以及所述至少一个其他探测方位的时间差在预设时间范围内。
  8. 根据权利要求1-3中任一项所述的控制方法，其中所述步骤S16还包括：根据至少一个第二通道在所述第一探测方位和第二探测方位时的回波脉冲，确定所述一个通道在所述第一探测方位和第二探测方位时位置稳定的回波脉冲。
  9. 根据权利要求1-3中任一项所述的控制方法，其中所述步骤S16包括：当所述一个通道在所述第一探测方位和第二探测方位时位置稳定的回波脉冲的幅值的差值或比值超过预设阈值时，将所述稳定的回波脉冲作为所述一个通 道在所述第一探测方位和/或第二探测方位的有效回波脉冲。
  10. 根据权利要求1-3中任一项所述的控制方法，其中所述步骤S11包括：
    通过以下方式确定所述第一发光时序和第二发光时序：根据该组通道中每个通道之前的测距结果、与该通道邻近的通道之前的测距结果以及障碍物信息中的一项或多项，确定所述第一发光时序和第二发光时序，所述第一发光时序和第二发光时序配置成使得：第一组回波脉冲和第二组回波脉冲在时间上相互错开。
  11. 根据权利要求10所述的控制方法，还包括：将该组通道的激光器的总飞行时间窗口至少分为第一区间和第二区间，其中所述第一发光时序配置成使得：第一组回波脉冲不重合地分布在所述第二区间内，所述第二发光时序配置成使得：第二组回波脉冲与第一组回波脉冲不重合地分布在所述第二区间内。
  12. 根据权利要求11所述的控制方法，还包括：将所述第二区间分为k个子区间，其中k为整数并且大于等于该组内通道的数目，其中所述第一发光时序配置成使得：第一组回波脉冲不重合地分布在所述k个子区间内；所述第二发光时序配置成使得：第二组回波脉冲与第一组回波脉冲不重合地分布在所述k个子区间内。
  13. 根据权利要求12所述的控制方法，其中所述每个子区间的长度大于所述回波脉冲的最大脉宽。
  14. 根据权利要求12所示的控制方法，其中所述第一发光时序配置成使得：所述第一组回波脉冲分布在所述k个子区间中未被占用并且距离最近的子区间内；所述第二发光时序配置成使得：所述第二组回波脉冲分布在所述k个子区间中未被占用并且距离最近的子区间内。
  15. 一种计算机存储介质，包括存储于其上的计算机可执行指令，所述可执行指令在被处理器执行时实施如权利要求1-14中任一项所述的控制方法。
  16. 一种激光雷达，包括：
    多个激光器，每个激光器发射的脉冲中至少一个脉冲作为测距脉冲；
    多个探测器，所述多个激光器和所述多个探测器构成多个通道，每个通道包括至少一个激光器和至少一个探测器；
    控制装置，所述控制装置与所述多个激光器和所述多个探测器连接，所述控制装置配置成：
    将所述多个通道分为多组，每组通道并行发光，对于其中一组通道，确定该组通道的激光器的发光时序，其中在第一探测方位所用的第一发光时序和在第二探测方位所用的第二发光时序不同；
    在所述第一探测方位，控制该组通道的激光器按照所述第一发光时序发射第一组探测脉冲；
    通过该组通道的探测器分别接收所述第一组探测脉冲自物体反射的第一组回波脉冲；
    在所述第二探测方位，控制该组通道的激光器按照所述第二发光时序发射第二组探测脉冲；
    通过该组通道的探测器分别接收所述第二组探测脉冲自物体反射的第二组回波脉冲；
    对于该组通道内的一个通道，根据所述一个通道的第一组回波脉冲和第二组回波脉冲，确定所述一个通道的有效回波脉冲。
  17. 根据权利要求16所述的激光雷达，其中所述第一发光时序和第二发光时序中，该组通道的至少部分激光器不同时发光。
  18. 根据权利要求16所述的激光雷达，其中该组通道中每个通道的探测器接 收的回波脉冲包括有效回波脉冲和由其他通道产生的串扰，所述控制装置配置成：根据时间匹配度，确定所述一个通道在所述第一探测方位和第二探测方位时重合的回波脉冲。
  19. 根据权利要求16-18中任一项所述的激光雷达，其中该组通道的激光器发射的脉冲中至少一个脉冲作为测距脉冲，所述控制装置配置成：对于该组通道内的一个通道，相对平移所述一个通道在所述第一探测方位和第二探测方位的测距脉冲的发射时间至重合，比对两次的测距结果，选出位置稳定的回波脉冲。
  20. 根据权利要求19所述的激光雷达，其中通过该组通道的探测器分别接收所述测距脉冲自物体反射的测距回波脉冲，所述控制装置配置成：对于该组通道内的一个通道，相对平移所述一个通道在所述第一探测方位和第二探测方位的测距脉冲的发射时间至重合，在时间上相互错开的测距回波脉冲为位置稳定的回波脉冲。
  21. 根据权利要求16-18中任一项所述的激光雷达，其中所述控制装置配置成：确定该组通道的激光器在第二探测方位之后的至少一个其他探测方位的发光时序，其中所述在至少一个其他探测方位的发光时序不同于所述第一发光时序和第二发光时序，所述控制装置还配置成：对于该组通道内的一个通道，确定所述一个通道在所述第一探测方位、第二探测方位以及至少一个其他探测方位时位置稳定的回波脉冲，作为所述一个通道在所述第一探测方位和/或第二探测方位的有效回波脉冲。
  22. 根据权利要求21所述的激光雷达，其中所述第一探测方位和所述第二探测方位以及所述至少一个其他探测方位的时间差在预设时间范围内。
  23. 根据权利要求16-18中任一项所述的激光雷达，其中所述控制装置还配 置成：根据至少一个第二通道在所述第一探测方位和第二探测方位时的回波脉冲，确定所述一个通道在所述第一探测方位和第二探测方位时位置稳定的回波脉冲。
  24. 根据权利要求16-18中任一项所述的激光雷达，其中所述控制装置还配置成：当所述一个通道在所述第一探测方位和第二探测方位时位置稳定的回波脉冲的幅值的差值或比值超过预设阈值时，将所述稳定的回波脉冲作为所述一个通道在所述第一探测方位和/或第二探测方位的有效回波脉冲。
  25. 根据权利要求16-18所述的激光雷达，其中所述控制装置还配置成：通过以下方式确定所述第一发光时序和第二发光时序：根据该组通道中每个通道之前的测距结果、与该通道邻近的通道之前的测距结果以及障碍物信息中的一项或多项，确定所述第一发光时序和第二发光时序，所述第一发光时序和第二发光时序配置成使得：第一组回波脉冲和第二组回波脉冲在时间上相互错开。
  26. 根据权利要求25所述的激光雷达，其中所述控制装置还配置成：将该组通道的激光器的总飞行时间窗口至少分为第一区间和第二区间，其中所述第一发光时序配置成使得：第一组回波脉冲不重合地分布在所述第二区间内，所述第二发光时序配置成使得：第二组回波脉冲与所述第一组回波脉冲不重合地分布在所述第二区间内。
  27. 根据权利要求26所述的激光雷达，其中所述控制装置还配置成：将所述第二区间分为k个子区间，其中k为整数并且大于等于该组内通道的数目，其中所述第一发光时序配置成使得：第一组回波脉冲不重合地分布在所述k个子区间内；所述第二发光时序配置成使得：第二组回波脉冲与所述第一组回波脉冲不重合地分布在所述k个子区间内。
  28. 根据权利要求27所述的激光雷达，其中所述每个子区间的长度大于所述回波脉冲的最大脉宽。
  29. 根据权利要求28所述的激光雷达，其中所述控制装置还配置成：所述第一发光时序配置成使得：所述第一组回波脉冲分布在所述k个子区间中未被占用并且距离最近的子区间内；所述第二发光时序配置成使得：所述第二组回波脉冲分布在所述k个子区间中未被占用并且距离最近的子区间内。
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Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106443699A (zh) * 2016-09-09 2017-02-22 深圳市砝石激光雷达有限公司 一种多组合式激光雷达装置及其扫描方法
US20180081041A1 (en) * 2016-09-22 2018-03-22 Apple Inc. LiDAR with irregular pulse sequence
CN108614254A (zh) * 2018-08-13 2018-10-02 北京经纬恒润科技有限公司 一种激光雷达
WO2019110206A1 (de) * 2017-12-04 2019-06-13 Osram Gmbh Lidar-system zur umfelderfassung und verfahren zum betreiben eines lidar-systems
US20200158825A1 (en) * 2018-11-21 2020-05-21 Infineon Technologies Ag Interference detection and mitigation for lidar systems
CN113176555A (zh) * 2020-01-24 2021-07-27 上海禾赛科技有限公司 激光雷达的发射单元、激光雷达以及测距方法
WO2021249983A1 (de) * 2020-06-10 2021-12-16 Robert Bosch Gmbh Verfahren und vorrichtung zur sicherstellung eines eindeutigkeitsbereichs eines lidar-sensors und einen solchen lidar-sensor
CN114114207A (zh) * 2021-11-25 2022-03-01 武汉万集光电技术有限公司 多线激光雷达设备和出光功率控制方法

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106443699A (zh) * 2016-09-09 2017-02-22 深圳市砝石激光雷达有限公司 一种多组合式激光雷达装置及其扫描方法
US20180081041A1 (en) * 2016-09-22 2018-03-22 Apple Inc. LiDAR with irregular pulse sequence
WO2019110206A1 (de) * 2017-12-04 2019-06-13 Osram Gmbh Lidar-system zur umfelderfassung und verfahren zum betreiben eines lidar-systems
CN108614254A (zh) * 2018-08-13 2018-10-02 北京经纬恒润科技有限公司 一种激光雷达
US20200158825A1 (en) * 2018-11-21 2020-05-21 Infineon Technologies Ag Interference detection and mitigation for lidar systems
CN113176555A (zh) * 2020-01-24 2021-07-27 上海禾赛科技有限公司 激光雷达的发射单元、激光雷达以及测距方法
WO2021249983A1 (de) * 2020-06-10 2021-12-16 Robert Bosch Gmbh Verfahren und vorrichtung zur sicherstellung eines eindeutigkeitsbereichs eines lidar-sensors und einen solchen lidar-sensor
CN114114207A (zh) * 2021-11-25 2022-03-01 武汉万集光电技术有限公司 多线激光雷达设备和出光功率控制方法

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