WO2023125093A1 - 一种激光雷达的发送装置、探测系统以及探测方法 - Google Patents

一种激光雷达的发送装置、探测系统以及探测方法 Download PDF

Info

Publication number
WO2023125093A1
WO2023125093A1 PCT/CN2022/139889 CN2022139889W WO2023125093A1 WO 2023125093 A1 WO2023125093 A1 WO 2023125093A1 CN 2022139889 W CN2022139889 W CN 2022139889W WO 2023125093 A1 WO2023125093 A1 WO 2023125093A1
Authority
WO
WIPO (PCT)
Prior art keywords
frequency
signal
sweeping
optical signal
sweep
Prior art date
Application number
PCT/CN2022/139889
Other languages
English (en)
French (fr)
Inventor
许丞
高红彪
曾理
Original Assignee
华为技术有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 华为技术有限公司 filed Critical 华为技术有限公司
Priority to CN202280043771.1A priority Critical patent/CN117561457A/zh
Publication of WO2023125093A1 publication Critical patent/WO2023125093A1/zh

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/4802—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00 using analysis of echo signal for target characterisation; Target signature; Target cross-section
    • 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
    • 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
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/483—Details of pulse systems
    • G01S7/486—Receivers
    • G01S7/4861—Circuits for detection, sampling, integration or read-out
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
    • G01S7/483—Details of pulse systems
    • G01S7/486—Receivers
    • G01S7/487—Extracting wanted echo signals, e.g. pulse detection
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A90/00—Technologies having an indirect contribution to adaptation to climate change
    • Y02A90/10—Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

Definitions

  • the present application relates to the technical field of optical communication, and in particular to a laser radar transmitting device, detection system and detection method.
  • Coherent laser radar can use the characteristics of the linear frequency modulation signal to make the beat frequency of the local oscillator signal and the echo signal generate a mixed frequency signal that changes with the distance and speed of the detected object.
  • the detected object can be calculated distance and speed information.
  • the directivity of the laser radar is high and the emitted light spot is small, when the emitted light reaches a distant object, the light spot diverges due to the long distance, so that the emitted light signal will be irradiated on multiple objects and multiple objects will be generated. echo signal. After multiple echo signals are coherently detected with local oscillator signals, multiple targets are located, and false targets cannot be excluded from multiple targets.
  • Embodiments of the present application provide a laser radar sending device, detection system, and detection method, so as to eliminate false targets in the case of multiple targets.
  • an embodiment of the present application provides a laser radar transmitting device, including a frequency sweep signal source and a multiplexer/demultiplexer component; wherein, the frequency sweep signal source transmits N frequency sweep optical signals, and N is an integer greater than 1.
  • the sweep slope of the first frequency sweep optical signal and the frequency sweep slope of the second frequency sweep optical signal among the N frequency sweep optical signals in the first time period are opposite in sign and the absolute value of the frequency sweep slope of the first frequency sweep optical signal
  • the absolute value of the frequency sweep slope of the second frequency sweep optical signal is different, or the frequency sweep slope of the first frequency sweep optical signal is not 0 and the frequency sweep slope of the second frequency sweep optical signal is 0; N frequency sweep optical signals different frequencies;
  • the multiplexing and demultiplexing component combines N frequency-sweeping optical signals to obtain the radar transmission signal, and performs optical splitting processing on the radar transmission signal to obtain the local oscillator signal and detection signal, transmits the detection signal through the antenna, and converts the local oscillator signal Send to the receiving device of the lidar.
  • the introduction of frequency-sweeping optical signals with different slopes enables multiple real targets to be coherently detected within at least two time periods respectively corresponding to different frequency-sweeping optical signals. Since the distance and speed of the real target calculated by different frequency-sweeping optical signals will not change, but the distance and speed of the false target will change, so the real target can be determined by the same result of coherent detection of multiple frequency-sweeping optical signals distance and speed, eliminating dummy targets without increasing detection time.
  • the first frequency-sweeping optical signal and the second frequency-sweeping optical signal are periodic frequency-sweeping optical signals.
  • the signal period of the first frequency-sweeping optical signal is M times the signal period of the second frequency-sweeping optical signal, or the signal period of the second frequency-sweeping signal is the signal period of the first frequency-sweeping optical signal M times of , M is a positive integer.
  • the signal period of the first frequency-sweeping optical signal is K times the detection period of the laser radar, or the signal period of the second frequency-sweeping optical signal is K times the detection period of the laser radar, and K is positive integer.
  • multiple detections are performed in one signal period, which can improve detection efficiency and reduce detection delay.
  • the sweep slope of the first frequency sweep signal in the first time period is opposite in sign to the frequency sweep slope in the second time period;
  • the frequency sweep slope of the frequency sweep signal in the first time period is opposite to the sign of the frequency sweep slope in the second time period;
  • the frequency sweep slope of the first frequency sweep signal in the first time period is different from that in the second time
  • the frequency sweep slope of the second frequency sweep signal in the period is different, and the frequency sweep slope of the second frequency sweep signal in the first time period is different from that of the first frequency sweep signal in the second time period
  • the sweep slopes are not the same.
  • the target signal period is the maximum signal period among the signal period of the first frequency-sweeping optical signal and the signal period of the second frequency-sweeping optical signal.
  • the sweeping slopes of the frequency-sweeping optical signals in the two time periods are different, so as to prevent different frequency-sweeping optical signals from being identical to the intermediate frequency signals obtained by beating the local oscillator signal, and further improve the accuracy of eliminating false targets.
  • the minimum frequency difference between the first frequency-sweeping optical signal and the second frequency-sweeping optical signal is related to the receiving bandwidth of the antenna.
  • the frequency range of each sweeping optical signal is determined based on the receiving bandwidth of the antenna, which can reduce generation of unnecessary beat frequency signals and improve the accuracy of calculation results.
  • the minimum frequency difference between the first frequency-sweeping optical signal and the second frequency-sweeping optical signal satisfies the following conditions:
  • f 1 represents the frequency sweep range of the first frequency sweep optical signal
  • f 2 represents the frequency sweep range of the second frequency sweep optical signal
  • fR 1 represents the relative echo signal of the first frequency sweep optical signal
  • fR 2 represents the local oscillator of the echo signal of the second frequency-sweeping optical signal relative to the second frequency-sweeping optical signal
  • the maximum value of the frequency frequency shift of the signal, and fOE represents the receiving bandwidth of the antenna.
  • the first frequency sweep signal and the second frequency sweep signal satisfy:
  • round () represents the rounding operation
  • K 1 represents the absolute value of the frequency sweep slope of the first frequency sweep signal within the first time period
  • K 2 represents the second frequency sweep slope within the first time period.
  • R min represents the minimum detectable distance of the lidar
  • c represents the speed of light.
  • the frequency sweep slopes of different frequency sweep optical signals meet the conditions shown above, and the minimum detectable distance is used to determine the frequency sweep slopes of different frequency sweep optical signals, which can prevent the difference between the frequency sweep slopes of different frequency sweep optical signals The smaller the accuracy of excluding false targets, the lower the accuracy of excluding false targets, and further improve the accuracy of excluding false targets.
  • the waveform of the first frequency-sweeping optical signal includes at least one of triangular wave, trapezoidal wave, and sawtooth wave; when the frequency-sweeping slope of the second frequency-sweeping optical signal is not 0, the The waveform of the second frequency-sweeping optical signal includes at least one of a triangular wave, a trapezoidal wave, and a sawtooth wave.
  • the wavelength ranges of the N frequency-sweeping optical signals are different, or the polarization directions of the N frequency-sweeping optical signals are different.
  • the frequency-sweeping signal source includes N frequency-sweeping lasers, and the frequency-sweeping lasers are used to emit a frequency-sweeping optical signal whose wavelength changes periodically.
  • the frequency ranges of the frequency-sweeping optical signals emitted by different frequency-sweeping lasers are different, so that the frequency-sweeping slope meets the requirements.
  • the frequency sweeping signal source includes a laser, a modulator, a radio frequency amplifier and a frequency sweeping driving signal source; After being amplified, it is input to a modulator; a laser is used to emit laser signals; a modulator is used to modulate N amplified frequency-sweeping signals onto the laser signals to obtain N frequency-sweeping optical signals.
  • a method of generating N frequency-sweeping optical signals satisfying requirements is provided by means of external adjustment.
  • the digital signal processing method is used to generate a frequency-sweeping electrical signal that meets the frequency requirements, and then modulate it to the laser signal emitted by the laser, which is simple to implement.
  • the frequency-sweeping signal source includes N frequency-sweeping signal transmitting components; any frequency-sweeping signal transmitting component in the N frequency-sweeping optical signal transmitting components includes a frequency-sweeping drive signal source, a laser, A modulator and a radio frequency amplifier; the frequency sweep driving signal source is used to generate a frequency sweep signal with a periodic frequency change, which is amplified by the radio frequency amplifier and then input to the modulator; the laser is used to emit a laser signal; The modulator is used to modulate the amplified frequency-sweeping signal onto the laser signal to obtain a frequency-sweeping optical signal; wherein, the wavelengths of the laser signals emitted by the lasers included in different frequency-sweeping signal transmitting components are different, and/or The frequency ranges of the frequency sweep signals generated by the frequency sweep driving signal sources included in different frequency sweep signal transmitting components are different.
  • a method of using N frequency-sweeping signal transmitting components to generate N frequency-sweeping optical signals is provided, and it is relatively easy to generate N frequency-sweeping optical signals meeting requirements.
  • the frequency-sweeping signal source includes a laser, an optical frequency comb, N microring modulators, and N frequency-sweeping drive signal sources;
  • the laser is used to emit laser signals;
  • the optical frequency comb It is used to process the laser signal to obtain optical signals of N wavelengths;
  • N frequency sweeping drive signal sources are connected to the N microring modulators in one-to-one correspondence, and the N microring modulators are in the N
  • the optical paths of the optical signals of two wavelengths are sequentially arranged in series; the first micro-ring modulator is used to modulate the frequency-sweeping signal output by the first frequency-sweeping driving signal source and the frequency range changes periodically to the corresponding first micro-ring modulator.
  • the N microring modulators correspond to the N wavelengths one by one, and the frequency ranges of the frequency sweep signals output by different frequency sweep driving signal sources are different.
  • a method of combining an optical frequency comb and N microring modulators to generate N frequency-sweeping optical signals is provided, which is relatively simple to implement.
  • the multiplexer/demultiplexer component includes a coupler, such as a directional coupler.
  • the polarization directions of the N frequency-sweeping optical signals are different, and the multiplexing and demultiplexing components include a polarization beam combiner and a polarization maintaining coupler; the polarization beam combiner is used to Combining the N frequency-sweeping optical signals according to the polarization direction of the frequency-sweeping optical signal to obtain a radar transmission signal; the polarization-maintaining coupler is used to split the radar transmission signal to obtain the local oscillator signal and the probe signal.
  • the embodiment of the present application provides a laser radar detection system, including the laser radar transmitting device described in the first aspect or any design of the first aspect, and the laser radar receiving device.
  • the receiving device is configured to receive the local oscillator signal from the sending device and the echo signal of the detection signal sent by the sending device, and perform frequency mixing processing on the echo signal and the local oscillator signal to generate a mixed Frequency signal; Obtain location information of the detected object according to the mixed frequency signal.
  • the receiving device may acquire the location information of the detected object by means of IQ detection.
  • the receiving device includes a 90-degree mixer, a first photodetector, a second photodetector, a first analog-to-digital converter, a second analog-to-digital converter, and a signal processor; the 90-degree mixer The frequency converter is used to mix the echo signal and the local oscillator signal of the detection signal received from the antenna to generate a mixed frequency signal, divide the mixed frequency signal into a first channel signal and a second channel signal, and divide the first channel signal The signal is sent to the first photodetector, and the second signal is sent to the second photodetector; the first photodetector is used to detect and process the first signal, and output it to the first analog-to-digital converter for further processing.
  • Analog-to-digital conversion the second photodetector is used to detect and process the second signal, and output it to the second analog-to-digital converter for analog-to-digital conversion;
  • the signal processor is used to output the signal from the first analog-to-digital converter The digital signal is processed with the digital signal output by the second analog-to-digital converter to obtain the location information of the detected object.
  • positive and negative frequency information can be distinguished by using the IQ detection method, which makes the processing algorithm simple and requires less processing performance of the signal processor.
  • the receiving device may use an I detection method or a Q detection method to acquire the location information of the detected object.
  • the receiving device includes a 180-degree mixer, a third photodetector, a third analog-to-digital converter, and a signal processor;
  • the 180-degree mixer is used for detecting signals received from the antenna The echo signal and the local oscillator signal are mixed to generate a mixed frequency signal, and the mixed frequency signal is sent to the third photodetector;
  • the third photodetector is used to detect and process the mixed frequency signal, and output it to the third mode
  • the digital converter performs analog-to-digital conversion;
  • the signal processor is used to process the digital signal output by the third analog-to-digital converter to obtain the location information of the detected object.
  • the I receiver or Q receiver is used to multiplex multiple frequency-sweeping optical signals to form a transmission signal.
  • the local oscillator signal of each frequency-sweeping optical signal can be compared with the The echo signal is beaten to calculate the mixed signal, and then the frequency component of the distance and the frequency component of the speed are respectively determined through the corresponding formulas in different situations, that is to say, three calculation results can be obtained based on each frequency-sweeping optical signal. Then the same result in multiple calculation results is the final calculation result, which can solve the problem of the speed at which the detection occurs due to the fact that the current I receiver or Q receiver cannot use the corresponding calculation results of the corresponding formulas in multiple situations. vague question.
  • the embodiment of the present application provides a lidar-based detection method, including: transmitting N frequency-sweeping optical signals, where N is an integer greater than 1, and in the first time period, the N frequency-sweeping optical signals
  • the sweep slope of the first frequency-sweeping optical signal is opposite to the sign of the sweeping slope of the second frequency-sweeping optical signal, or the sweeping slope of the first frequency-sweeping optical signal is 0 and the sweeping slope of the second frequency-sweeping optical signal
  • the frequency sweep slope is not 0; the frequency of the N frequency sweep optical signals is different; the radar emission signal obtained by combining the N frequency sweep optical signals, and dividing the radar emission signal into a local oscillator signal and a A detection signal, the detection signal is transmitted through the antenna; the local oscillator signal is used for coherent detection with the echo signal of the detection signal to obtain the location information of the detection object.
  • the detection method may further include: receiving an echo signal of the detection signal from the antenna, and performing frequency mixing processing on the echo signal and the local oscillator signal to generate a mixed frequency signal; according to The mixed frequency signal obtains the location information of the detected object.
  • the first frequency-sweeping optical signal and the second frequency-sweeping optical signal are periodic frequency-sweeping optical signals.
  • the signal period of the first frequency-sweeping optical signal is M times the signal period of the second frequency-sweeping optical signal, or the signal period of the second frequency-sweeping signal is M times the signal period of a frequency-sweeping optical signal, where M is a positive integer.
  • the signal period of the first frequency-sweeping optical signal is K times the detection period of the laser radar, or the signal period of the second frequency-sweeping optical signal is K times the detection period of the laser radar K times the period, K is a positive integer.
  • the sweep slope of the first frequency sweep optical signal in the first time period is opposite in sign to the sweep slope in the second time period;
  • the frequency sweep slope of the second frequency sweep optical signal in the first time period is opposite to the sign of the frequency sweep slope in the second time period;
  • the frequency sweep slope of the first frequency sweep optical signal in the first time period is the same as the The frequency sweep slope of the second frequency sweep optical signal in the second time period is different, and the frequency sweep slope of the second frequency sweep optical signal in the first time period is different from the frequency sweep slope of the second frequency sweep optical signal in the second time period.
  • the sweeping slopes of the first frequency-sweeping optical signals are different.
  • the target signal period is the maximum signal period among the signal period of the first frequency-sweeping optical signal and the signal period of the second frequency-sweeping optical signal.
  • the minimum frequency difference between the first frequency-sweeping optical signal and the second frequency-sweeping optical signal is related to the receiving bandwidth of the antenna.
  • the minimum frequency difference between the first frequency-sweeping optical signal and the second frequency-sweeping optical signal satisfies the following conditions:
  • f 1 represents the frequency sweep range of the first frequency sweep optical signal
  • f 2 represents the frequency sweep range of the second frequency sweep optical signal
  • fR 1 represents the relative echo signal of the first frequency sweep optical signal
  • fR 2 represents the local oscillator of the echo signal of the second frequency-sweeping optical signal relative to the second frequency-sweeping optical signal
  • fOE represents the receiving bandwidth of the antenna.
  • the first frequency sweep signal and the second frequency sweep signal satisfy:
  • round () represents the rounding operation
  • K 1 represents the absolute value of the frequency sweep slope of the first frequency sweep signal within the first time period
  • K 2 represents the second frequency sweep slope within the first time period.
  • R min represents the minimum detectable distance of the lidar
  • c represents the speed of light.
  • the waveform of the first frequency-sweeping optical signal includes at least one of triangular wave, trapezoidal wave, and sawtooth wave; when the frequency-sweeping slope of the second frequency-sweeping optical signal is not 0, the The waveform of the second frequency-sweeping optical signal includes at least one of a triangular wave, a trapezoidal wave, and a sawtooth wave.
  • the wavelength ranges of the N frequency-sweeping optical signals are different, or the polarization directions of the N frequency-sweeping optical signals are different.
  • FIG. 1 is a schematic diagram of a lidar architecture
  • Fig. 2 is a schematic diagram of a local oscillator signal, an echo signal and a mixed frequency signal
  • Fig. 3 is a schematic diagram of the frequency spectrum of a mixed frequency signal
  • Fig. 4 is a schematic diagram of a generated false target
  • Fig. 5 is a schematic diagram of a waveform of a mixed frequency signal
  • FIG. 6 is a schematic diagram of the detection system architecture of the laser radar provided by the embodiment of the present application.
  • FIG. 7 is a schematic waveform diagram of a frequency-sweeping optical signal provided by an embodiment of the present application.
  • FIG. 8 is a schematic diagram of waveforms of the first frequency-sweeping optical signal and the second frequency-sweeping optical signal provided by the embodiment of the present application;
  • FIG. 9 is a schematic diagram of the frequency spectrum of the mixed frequency signal in the case of two detection targets provided by the embodiment of the present application.
  • Fig. 10 is a schematic diagram of the distance-velocity calculation principle provided by the embodiment of the present application.
  • FIG. 11 is a schematic diagram of the output waveform of the frequency-sweeping optical signal in the polarization multiplexing mode provided by the embodiment of the present application.
  • FIG. 12 is a schematic diagram of the relationship between the detection period and the signal period provided by the embodiment of the present application.
  • FIG. 13 is a schematic structural diagram of a receiving device 620 provided in an embodiment of the present application.
  • FIG. 14 is a schematic structural diagram of another receiving device 620 provided in the embodiment of the present application.
  • FIG. 15A is a schematic diagram of a detection system architecture provided by an embodiment of the present application.
  • FIG. 15B is a schematic diagram of the waveforms of two frequency-sweeping optical signals and the frequency spectrum of a mixed signal in the case of a detection target provided by the embodiment of the present application;
  • FIG. 16 is a schematic diagram of a detection system architecture provided by an embodiment of the present application.
  • FIG. 17 is a schematic diagram of a detection system architecture provided by an embodiment of the present application.
  • FIG. 18 is a schematic diagram of a detection system architecture provided by an embodiment of the present application.
  • FIG. 19 is a schematic diagram of a detection system architecture provided by an embodiment of the present application.
  • FIG. 20 is a schematic diagram of the generation method of the frequency sweep driving signal source provided by the embodiment of the present application.
  • FIG. 21 is a schematic diagram of a detection system architecture provided by an embodiment of the present application.
  • FIG. 22 is a schematic diagram of the generation method of the frequency sweep driving signal source provided by the embodiment of the present application.
  • FIG. 23 is a schematic diagram of a detection system architecture provided by an embodiment of the present application.
  • FIG. 24 is a schematic diagram of a detection system architecture provided by an embodiment of the present application.
  • FIG. 25 is a schematic flowchart of a laser radar detection method provided by an embodiment of the present application.
  • At least one of the following” or similar expressions refer to any combination of these items, including any combination of single or plural items.
  • at least one item (piece) of a, b, or c can represent: a, b, c, a-b, a-c, b-c, or a-b-c, where a, b, c can be single or multiple .
  • a frequency sweep signal refers to a signal whose frequency varies linearly with time.
  • Sweeping waveform the trace of the sweeping signal.
  • Sweep frequency slope the frequency change of the frequency sweep signal per unit time, unit Hz/s.
  • Sign of Sweep Slope When the sign of the sweep slope is positive, the frequency increases with time. When the sign of the sweep slope is negative, the frequency decreases with time. When the sign of the sweep slope is zero, the frequency does not change over time.
  • the opposite signs of the two sweep slopes means that one of the sweep slopes has a positive sign and the other sweep slope has a negative sign.
  • Guard bandwidth means that when signals are frequency multiplexed, there is a certain frequency range between signals, and no signal is loaded within this range to prevent signals of different frequencies from interfering with each other.
  • the radar transmission signal is generated by one or more frequency sweep signals, and after frequency multiplexing, the signal can be transmitted by the transmitting antenna.
  • Radar signals are generally optical signals.
  • Echo signal The signal reflected back after the transmitted signal reaches the detection object.
  • the echo signal is generally an optical signal.
  • the minimum detectable distance of the lidar some lidars have a blind area, and objects close to the lidar cannot be detected, such as 1 meter, etc.
  • the minimum distance of the blind area is the minimum detectable distance of the lidar.
  • Some laser radars do not have blind spots, but because some objects are close to the laser radar, due to the limitation of processor accuracy or algorithm, after the laser radar sends a detection signal, after the closer object sends an echo signal, the laser radar cannot pass the echo signal Accurate positioning to the exact location of the object. Therefore, the minimum distance that can be accurately positioned is the minimum detectable distance of the lidar.
  • LiDAR can be installed on vehicles, boats or other machines.
  • the laser radar emits a frequency-sweeping optical signal through a frequency-sweeping signal source.
  • the frequency-sweeping optical signal will be reflected by the object after it hits the detection object, and the reflected echo signal can be received by the receiving end of the laser radar. Therefore, the receiving end of the laser radar generates an intermediate frequency signal that changes with the distance and speed of the detected object according to the beat frequency of the echo signal and the local oscillator signal. According to the frequency of the intermediate frequency signal, the distance, speed and reflectivity of the measured object can be calculated. information.
  • the light spots of the laser radar will diverge, so that the emitted light signal will generate multiple echo signals for detecting the target.
  • two echo signals and local oscillator signals are coherently detected to generate multiple mixed frequency signals.
  • the echo signal 1 is coherently detected with the local oscillator signal to generate a mixed frequency signal 1 ;
  • the echo signal 2 is coherently detected with the local oscillator signal to generate a mixed frequency signal 2 .
  • time can be divided into time period 1 and time period 2. The sweeping slopes of the transmitted signal or echo signal are different in different time periods.
  • the distance-related frequency and speed-related frequency of the detection target can be determined. Then further calculate the distance of the detection target according to the distance correlation frequency, and calculate the speed of the detection target according to the speed correlation frequency. Since there are 2 frequency components in time period 1 and 2 frequency components in time period 2, the distances and velocities of 4 detection targets can be calculated through combination.
  • the relationship between the frequency component of time period 1 and the frequency component of time period 2 and the distance-related frequency and speed-related frequency satisfies the following formula (1):
  • f 1 represents the frequency component of time period 1
  • f 2 represents the frequency component of time period 2
  • f R represents the distance-related frequency
  • f D represents the speed-related frequency.
  • f R and f D can be calculated by the following formula (2).
  • the distance of the detection target can be determined by the following formula (3), and the speed of the detection target can be determined by the following formula (4).
  • R represents the distance between the detection target and the lidar
  • B represents the sweep bandwidth of the emitted optical signal
  • T is the duration of a time period, such as time period 1 or time period 2.
  • ⁇ represents the wavelength of light
  • V represents the moving speed of the detection target.
  • (1)-(3) in FIG. 5 are schematic diagrams of frequency changes of local oscillator signals and echo signals in three possible situations.
  • the mixed frequency signal of time period 1 and the mixed frequency signal of time period 2 can be seen in Figure 5 (4) shown.
  • the mixed frequency signal of time period 1 and the frequency mixed signal of time period 2 can be referred to as shown in (7) in FIG. 5 , and the detection of the IQ receiver can distinguish between positive and negative frequencies.
  • the mixed frequency signal of time period 1 and the mixed frequency signal of time period 2 can be referred to in Figure 5 ( 5) as shown.
  • the mixed frequency signal of time period 1 and the mixed frequency signal of time period 2 can be referred to as shown in (8) in FIG. 5 , and the detection of the IQ receiver can distinguish between positive and negative frequencies.
  • I receiver or Q receiver since I receiver or Q receiver cannot distinguish between positive and negative frequencies, theoretically the frequency component of time period 1 and the frequency component of time period 2 are related to the distance-related frequency and speed-related frequency The relationship should satisfy the condition shown in the following formula (7).
  • the mixed frequency signal of time period 1 and the actual mixed frequency signal of time period 2 can be referred to in Figure 5 Shown in (6).
  • the mixed frequency signal of the time period 1 and the mixed frequency signal of the time period 2 can be referred to as shown in (9) in FIG. 5 , and the detection of the IQ receiver can distinguish between positive and negative frequencies.
  • I receiver or Q receiver since I receiver or Q receiver cannot distinguish between positive and negative frequencies, theoretically the frequency component of time period 1 and the frequency component of time period 2 are related to the distance-related frequency and speed-related frequency The relationship should satisfy the condition shown in the following formula (8).
  • the present application provides a laser radar sending device, measuring device and detection method, which can realize simultaneous detection of multiple targets without increasing the detection time, and the detection results are more accurate, even if I receiver or Q receiver is used. There will be a speed blur problem.
  • the detection object is also referred to as a reflector, and the detection object may be any object in the scanning direction of the antenna, for example, it may be a person, a mountain, a vehicle, a tree, a bridge, and the like.
  • the embodiment of the present application relates to an antenna including a transmitting antenna for transmitting optical signals and a receiving antenna for receiving optical signals, which may also be referred to as a scanner, and is used for transmitting optical signals and receiving optical signals.
  • the detection system 600 includes a sending device 610 and a receiving device 620 .
  • the detection system can be applied to distance measuring equipment or speed measuring equipment, for example, it can be applied to FMCW lidar, laser speed measuring instrument, laser range finder, optical coherence tomography (optical coherence tomography, OCT) equipment or optical frequency domain reflectometer ( optical frequency domain reflectometer, OFDR) equipment, etc.
  • OCT optical coherence tomography
  • OFDR optical frequency domain reflectometer
  • the sending device 610 may include a frequency sweep signal source 611 and a multiplexer/demultiplexer component 612 .
  • the frequency-sweeping signal source 611 transmits N frequency-sweeping optical signals. N is an integer greater than 1.
  • the frequency-sweeping signal source can be generated by direct modulation of the laser (also called internal modulation), or by external modulation of the optical signal generated by the laser with a modulator. The structure that can be adopted by the frequency sweep signal source will be described in detail later, and will not be repeated here.
  • the N frequency-sweeping signals include at least two frequency-sweeping optical signals with different frequency-sweeping waveforms.
  • the frequency ranges of the N frequency-sweeping optical signals are different.
  • the two frequency-sweeping signals are referred to as a first frequency-sweeping optical signal and a second frequency-sweeping optical signal.
  • the first frequency-sweeping optical signal and the second frequency-sweeping optical signal at least satisfy the following conditions 1 and 2:
  • the period between the first frequency-sweeping optical signal and the second frequency-sweeping optical signal includes at least a time period in which the sign of the frequency-sweeping slope is opposite. This time period is referred to herein as the first time period. It can be understood that, within the first time period, the sweep slope of the first frequency-sweeping optical signal and the frequency-sweeping slope of the second frequency-sweeping optical signal have opposite signs.
  • the absolute value of the sweep slope of the first frequency-sweeping optical signal is different from the absolute value of the frequency-sweeping slope of the second frequency-sweeping optical signal within the first time period.
  • the first frequency-sweeping optical signal and the second frequency-sweeping optical signal satisfy the following condition 3.
  • Condition 3 there is a certain time period in which the sweep slope of one of the first frequency-sweeping optical signal and the second frequency-sweeping optical signal is 0, and the sweeping slope of the other frequency-sweeping optical signal is not 0.
  • the sweep slope of the first frequency-sweeping optical signal is 0 in the first time period, and the sweeping slope of the second frequency-sweeping optical signal is not 0.
  • the sweep slope of the first frequency-sweeping optical signal is not 0 in the first time period, and the sweeping slope of the second frequency-sweeping optical signal is 0.
  • At least one of the following conditions 4 to 7 is also satisfied among the N frequency-sweeping optical signals.
  • the N frequency-sweeping optical signals are all periodic frequency-sweeping optical signals, or a certain frequency-sweeping optical signal is a constant-frequency signal, that is, the sweeping slope of the frequency-sweeping optical signal is 0.
  • the signal periods among the N frequency-sweeping optical signals satisfy a multiple relationship, and the multiple may also be 1, that is, the signal periods of the frequency-sweeping optical signals are equal.
  • both the first frequency-sweeping optical signal and the second frequency-sweeping optical signal are periodic frequency-sweeping optical signals.
  • the signal periods of the first frequency-sweeping optical signal and the second frequency-sweeping optical signal satisfy a multiple relationship.
  • the signal period of the first frequency-sweeping optical signal is M times the signal period of the second frequency-sweeping optical signal, or the signal period of the second frequency-sweeping optical signal is M times the signal period of the first frequency-sweeping optical signal.
  • M can be 1 or an integer greater than 1.
  • Condition 5 In one target signal period, there are two time periods in which the sign of the sweep slope is opposite to that of the first frequency-sweeping optical signal and the second frequency-sweeping optical signal. In addition to the opposite sign of the frequency sweep slope of the second frequency sweep optical signal, there is at least one time period in which the frequency sweep slope signs of the first frequency sweep optical signal and the second frequency sweep optical signal are opposite. For ease of distinction, the time period other than the first time period is referred to as the second time period.
  • a target signal cycle mentioned here refers to the maximum value of the signal cycle of the first frequency-sweeping optical signal and the second frequency-sweeping optical signal. Take for example that the signal period of the first frequency-sweeping optical signal is greater than or equal to the signal period of the second frequency-sweeping signal.
  • the sign of the frequency-sweep slope of the first frequency-sweep signal in the first time period is opposite to that of the frequency-sweep slope in the second time period;
  • the sweep slope of the first time period is opposite in sign to the sweep slope of the second time period;
  • the sweep slope of the first frequency sweep signal in the first time period is different from the sweep slope of the second frequency sweep signal in the second time period , and
  • the frequency sweep slope of the second frequency sweep signal in the first time period is different from the frequency sweep slope of the first frequency sweep signal in the second time period.
  • Condition 6 Among the N frequency-sweeping optical signals, there is a guard bandwidth between two frequency-adjacent frequency-sweeping optical signals.
  • the setting of the guard bandwidth is related to the receive bandwidth of the antenna.
  • the first frequency-sweeping optical signal and the second frequency-sweeping optical signal are two frequency-sweeping optical signals with the smallest frequency difference among the N frequency-sweeping optical signals.
  • the minimum frequency difference between the first frequency-sweeping optical signal and the second frequency-sweeping optical signal is related to the receiving bandwidth of the antenna.
  • the minimum frequency difference between the first frequency-sweeping optical signal and the second frequency-sweeping optical signal satisfies the condition shown in the following formula (9).
  • f 1 represents the frequency sweep range of the first frequency sweep optical signal
  • f 2 represents the frequency sweep range of the second frequency sweep optical signal
  • fR 1 represents the echo signal of the first frequency sweep optical signal relative to the first frequency sweep light
  • fOE represents The receiving bandwidth of the antenna.
  • round () represents the rounding operation
  • K 1 represents the absolute value of the frequency sweep slope of the first frequency sweep signal within the first time period
  • K 2 represents the second frequency sweep slope within the first time period.
  • R min represents the minimum detectable distance of the lidar
  • c represents the speed of light.
  • the conditions satisfied by the N frequency-sweeping optical signals in the embodiment of the present application may include various combinations of the above conditions.
  • N frequency-sweeping optical signals satisfy condition 1+condition 2+condition 6+condition 7.
  • N frequency-sweeping optical signals satisfy condition 3+condition 6+condition 7.
  • N frequency-sweeping optical signals satisfy condition 1+condition 2+condition 4+condition 5+condition 6+condition 7.
  • N frequency-sweeping optical signals satisfy condition 1+condition 2+condition 5+condition 6+condition 7, etc., which will not be listed here.
  • each periodic signal of the N frequency-sweeping optical signals involved in the present application may adopt frequency-sweeping waveforms whose frequencies vary linearly with time, such as triangular waves, trapezoidal waves, and sawtooth waves, or any combination of the above-mentioned waveforms.
  • some frequency-sweeping optical signals may adopt a constant-frequency waveform, that is, the frequency-sweeping slope is 0. As an example, see the frequency sweep waveform shown in FIG. 7 .
  • the multiplexer/demultiplexer component 612 combines the N frequency-sweeping optical signals to obtain the radar transmission signal, and performs light-splitting processing on the radar transmission signal to obtain the local oscillator signal and detection signal, transmits the detection signal through the antenna, and sends the local oscillator signal to the laser
  • the receiving device 620 of the radar The multiplexer/demultiplexer component 612 combines the N frequency-sweeping optical signals to obtain the radar transmission signal, and performs light-splitting processing on the radar transmission signal to obtain the local oscillator signal and detection signal, transmits the detection signal through the antenna, and sends the local oscillator signal to the laser
  • the receiving device 620 of the radar The receiving device 620 of the radar.
  • the receiving device 620 receives the local oscillator signal from the sending device 610 and the echo signal of the detection signal sent by the sending device 610, performs frequency mixing processing on the echo signal and the local oscillator signal to generate a mixed frequency signal, and then obtains the detection signal according to the mixed frequency signal.
  • the location information of the object includes information such as the speed of the detected object, the distance from the lidar, and the reflectivity.
  • frequency multiplexing or polarization multiplexing may be used when combining the N frequency-sweeping optical signals. It should be noted that when the polarization multiplexing method is adopted, there is no requirement for the guard bandwidth described in the above condition 6 among the N frequency-sweeping optical signals.
  • the first frequency-sweeping optical signal and the second frequency-sweeping optical signal as an example, and the first frequency-sweeping optical signal and the second frequency-sweeping optical signal are multiplexed in a frequency multiplexing manner before transmission.
  • Several possible frequency sweep waveforms of two frequency sweep optical signals are described with reference to FIG. 8 .
  • the frequency sweep bandwidth of the first frequency sweep optical signal is B1 and the frequency sweep bandwidth of the second frequency sweep optical signal is B2.
  • the first frequency-sweeping optical signal and the second frequency-sweeping optical signal have at least two time periods in which the sign of the frequency-sweeping slope is opposite.
  • the sweep slope of the first frequency-sweeping optical signal and the frequency-sweeping slope of the second frequency-sweeping optical signal have opposite signs in the first time period, and the absolute values of the sweeping slopes are different.
  • the sweep slope of the first frequency-sweeping optical signal and the frequency-sweeping slope of the second frequency-sweeping optical signal have opposite signs, and the absolute values of the sweeping slopes are not equal.
  • the sweeping slope of the first frequency-sweeping optical signal in the first time period is different from the sweeping slope of the second frequency-sweeping optical signal in the second time period, and the sweeping frequency of the second frequency-sweeping optical signal in the first time period
  • the slope is different from the frequency sweep slope of the first frequency sweep optical signal in the second time period.
  • the first frequency-sweeping optical signal and the second frequency-sweeping optical signal shown in (1) in FIG. 8 are taken as an example to describe the effect of accurately obtaining positioning information of multiple targets.
  • two detection targets are taken as an example.
  • the two echo signals respectively corresponding to the local oscillator signal 1 of the first frequency-sweeping optical signal are echo signal 1-1 and echo signal 1-2.
  • the two echo signals respectively corresponding to the local oscillator signal 2 of the second frequency-sweeping optical signal are an echo signal 2-1 and an echo signal 2-2.
  • the frequency spectrum of the mixing signal produced by beat frequency in time period 1, shown in (2) in Fig. 9 is the spectrum diagram of the mixing signal adopting I receiver, referring to (4) in Fig. 9 being the mixing signal adopting IQ receiver Spectrum plot of the frequency signal.
  • the frequency spectrum of the mixing signal produced by the beat frequency in the time segment 2, shown in (3) in Fig. 9 is the spectrum diagram of the mixing signal of the I receiver, referring to (5) in Fig. 9 for the mixing of the IQ receiver Spectrum plot of the frequency signal.
  • the velocity of the detection target and the distance of the detection target can be determined based on formula (2)-formula (4).
  • the speed and distance of the detection target can be calculated respectively through the following formulas (6)-(8) in combination with formulas (3) and (4). Since multiple frequency-sweeping optical signals are used for detection in the embodiment of the present application, the mixed frequency signals obtained by mixing each frequency-sweeping optical signal with the local oscillator signal can be combined by the following formulas (6)-(8) Equations (3) and (4) calculate the velocity and distance of the detected target.
  • the real target Due to the introduction of frequency-sweeping optical signals with different slopes, the real target is coherently detected in two time periods corresponding to different frequency-sweeping optical signals. Since the distance and speed of the real target calculated by different frequency-sweeping optical signals will not change, but the distance and speed of the false target will change. Therefore, as shown in Figure 10, the speed and distance corresponding to the intersection of the four lines are is the speed and distance of the real target.
  • the transmitted signals formed by frequency multiplexing of frequency-swept signals with different sweep slopes are used to detect M detection objects, which can eliminate false targets without increasing the detection time.
  • the transmission signal formed by transmitting frequency multiplexing is used to realize the distinction of multiple targets without increasing the measurement time and maintaining the laser radar exit rate unchanged.
  • this embodiment of the present application supports the use of an I receiver or a Q receiver or an IQ receiver. When I receiver or Q receiver is used, multiple frequency-sweeping optical signals are used to frequency-multiplex to form a transmission signal.
  • the local oscillator signal of each frequency-sweeping optical signal can be Beat frequency with the echo signal to calculate the mixed signal, and then determine the frequency component of the distance and the frequency component of the speed through the above formulas (6)-(8), that is to say, based on each frequency-sweeping optical signal, three result.
  • the two identical results in the calculation results of the two frequency-sweeping optical signals are the final calculation results, which can solve the problem of the existing detection speed using I receiver or Q receiver. vague question. And using an I receiver or a Q receiver can reduce costs compared to using an IQ receiver.
  • the first frequency-sweeping optical signal and the second frequency-sweeping optical signal as an example, and the first frequency-sweeping optical signal and the second frequency-sweeping optical signal are multiplexed by polarization multiplexing before transmission .
  • Several possible frequency sweep waveforms of two frequency sweep optical signals are described with reference to FIG. 11 .
  • the frequency sweep bandwidth of the first frequency sweep optical signal is B1 and the frequency sweep bandwidth of the second frequency sweep optical signal is B2.
  • the first frequency-sweeping optical signal and the second frequency-sweeping optical signal have at least two time periods in which the sign of the frequency-sweeping slope is opposite.
  • the sweeping slope of the first frequency-sweeping optical signal and the frequency-sweeping slope of the second frequency-sweeping optical signal have opposite signs in the first time period, and the absolute values of the sweeping slopes are different.
  • the sweep slope of the first frequency-sweeping optical signal and the frequency-sweeping slope of the second frequency-sweeping optical signal have opposite signs, and the absolute values of the sweeping slopes are not equal.
  • the sweeping slope of the first frequency-sweeping optical signal in the first time period is different from the sweeping slope of the second frequency-sweeping optical signal in the second time period, and the sweeping frequency of the second frequency-sweeping optical signal in the first time period
  • the slope is different from the frequency sweep slope of the first frequency sweep optical signal in the second time period.
  • the frequency-sweeping optical signals with different frequency-sweeping slopes are polarized multiplexed to form a transmission signal to detect M detection objects, which can eliminate false targets without increasing the measurement time, and maintain the lidar out-point rate unchanged.
  • the use of I receivers or Q receivers or IQ receivers is supported.
  • I receiver or Q receiver When I receiver or Q receiver is used, multiple frequency-sweeping optical signals are used to frequency-multiplex to form a transmission signal.
  • the local oscillator signal of each frequency-sweeping optical signal can be Beat frequency with the echo signal to calculate the mixed signal, and then determine the frequency component of the distance and the frequency component of the speed through the above formulas (6)-(8), that is to say, based on each frequency-sweeping optical signal, three result.
  • the two identical results in the calculation results of the two frequency-sweeping optical signals are the final calculation results, which can solve the problem of the existing detection speed using I receiver or Q receiver. vague question. And using an I receiver or a Q receiver can reduce costs compared to using an IQ receiver.
  • the signal period of the frequency-sweeping optical signal is K times the detection period of the lidar.
  • the signal period of the frequency-sweeping optical signal mentioned here may be the largest signal period among the signal periods of the N frequency-sweeping optical signals.
  • K is a positive integer.
  • the detection period refers to the time for obtaining the positioning information of a detection object.
  • the frequency-sweeping bandwidths of the first frequency-sweeping optical signal and the second frequency-sweeping optical signal are different.
  • the detection period is represented by T in FIG. 12 .
  • the first frequency-sweeping optical signal and the second frequency-sweeping optical signal in (1) in FIG. 12 are both triangular waves, and the signal period is equal to the detection period.
  • the first frequency-sweeping optical signal and the second frequency-sweeping optical signal in (2) in FIG. 12 are both trapezoidal waves, and the signal period is twice the detection period.
  • the first frequency-sweeping optical signal is a triangular wave
  • the second frequency-sweeping optical signal is a trapezoidal wave
  • the signal period is twice the detection period.
  • the first frequency-sweeping optical signal is a triangular wave
  • the second frequency-sweeping optical signal is a constant-frequency wave
  • the signal period is equal to the detection period.
  • FIG. 12 is only used to exemplarily describe the multiple relationship between the signal period and the detection period, which can be configured according to requirements in specific scenarios, and is not specifically limited in this embodiment of the present application.
  • the receiving device 620 may deploy one or more IQ receivers, or deploy I receivers or Q receivers.
  • FIG. 13 is a schematic structural diagram of a possible IQ receiver.
  • the IQ receiver includes a 90-degree mixer 6201 , a first photodetector 6202 and a second photodetector 6203 , a first analog-to-digital converter 6204 and a second analog-to-digital converter 6205 , and a signal processor 6206 .
  • the receiving device 620 may further include a receiving antenna, and the receiving antenna may also be located outside the receiving device 620 .
  • the receiving device 620 may also include other devices, which are not specifically limited in the present application, and structures of IQ receivers capable of implementing IQ detection are applicable to the embodiments of the present application.
  • the 90-degree mixer 6201 receives the echo signal from the antenna.
  • the received echo signals include N frequency-sweeping optical signals corresponding to the echo signals respectively. When there are multiple detection objects, the echo signals corresponding to each frequency-sweeping optical signal include multiple.
  • the 90-degree mixer 6201 also receives a local oscillator signal from the transmitting device 610 .
  • the received local oscillator signals include local oscillator signals respectively corresponding to the N frequency-sweeping optical signals.
  • the 90-degree mixer 6201 performs frequency mixing processing on the local oscillator signal and the echo signal, and outputs two optical signals, which are the I component optical signal and the Q component optical signal.
  • the first photodetector 6202 performs photodetection on the I-component optical signal, and converts the I-component optical signal into a first analog electrical signal.
  • the second photodetector 6203 performs photodetection on the Q component optical signal, and converts the Q component optical signal into a second analog electrical signal.
  • the first analog-to-digital converter 6204 samples the first analog electrical signal, converts the first analog electrical signal into a first digital signal
  • the second analog-to-digital converter 6205 samples the second analog electrical signal, and converts the second analog electrical signal converted to a second digital signal.
  • the signal processor 6206 processes the first digital signal and the second digital signal to obtain location information of the detected object.
  • the first photodetector 6202 and the second photodetector 6203 may be single-ended photodetectors or balanced photo detectors (balanced photo detectors, BPD).
  • Signal processor 6206 may include digital signal processor (digital signal processor, DSP), central processing unit (CPU), accelerated processing unit (APU), image processing unit (GPU), microprocessor or microcontroller
  • DSP digital signal processor
  • CPU central processing unit
  • APU accelerated processing unit
  • GPU image processing unit
  • microprocessor or microcontroller The signal processor 6206 is used to process the sampled digital signal, so as to obtain the positioning information such as the speed and distance of the target detection object.
  • the operation of processing the sampled digital signal to obtain information such as the speed and distance of the target can be completed by one or more signal processors 6206, for example, by one or more DSPs, Of course, it can also be completed by one or more signal processors 6206 in combination with other devices, for example, a DSP combined with one or more central processing units CPU to jointly complete.
  • the signal processor 6206 processes the sampled digital signal, it can be implemented by invoking a computer program stored in a computer-readable storage medium.
  • the computer-readable storage medium includes but is not limited to a random access memory (random access memory, RAM), read only memory (ROM), erasable programmable read only memory (EPROM), or portable read only memory (compact disc read only memory, CD ROM), which can It is configured in the signal processor 6206, or it may be independent of the signal processor 6206.
  • RAM random access memory
  • ROM read only memory
  • EPROM erasable programmable read only memory
  • CD ROM compact disc read only memory
  • FIG. 14 is a schematic structural diagram of a possible I receiver.
  • the I receiver includes a 180-degree mixer 62011, a photodetector 62012, an analog-to-digital converter (analog digital converter, ADC) 62013, and a signal processor 62014.
  • the 180-degree mixer 62011 mixes the local oscillator signal and the echo signal processing, and output the I component optical signal.
  • the photodetector 62012 performs photodetection on the I component optical signal to obtain an analog electrical signal.
  • the analog-to-digital converter 62013 converts analog electrical signals into digital signals.
  • the signal processor 62014 processes the digital signal to obtain the location information of the detected object.
  • the receiving device 620 may further include a receiving antenna, and the receiving antenna may also be located outside the receiving device 620. It should be noted that the receiving device 620 may also include other devices, which are not specifically limited in the present application, and the structure of the I receiver capable of implementing I detection is applicable to the embodiments of the present application.
  • FIG. 15A it is a schematic structural diagram of a possible detection system.
  • FIG. 15A uses frequency multiplexing as an example for description.
  • the frequency-sweeping signal source 611 includes N frequency-sweeping lasers that are directly modulated. In FIG. 15A , taking N as 2 as an example, they are the frequency-sweeping laser 61111 and the frequency-sweeping laser 61112 .
  • the multiplexer/demultiplexer component 612 includes at least one directional waveguide coupler 6121 .
  • the receiving device 620 may use an IQ receiver, or may use an I receiver or a Q receiver.
  • FIG. 15A uses an IQ receiver as an example, and the structure of the IQ receiver takes the structure shown in FIG. 13 as an example. For simplicity of description, the components in the IQ receiver are not identified anymore.
  • the wavelength of the frequency-sweeping laser 6111 changes with time, so that the frequency of the output frequency-sweeping optical signal changes within a set frequency range.
  • different frequency-sweeping lasers 6111 have different wavelength ranges.
  • the frequency-sweeping laser 61111 outputs a frequency-sweeping optical signal 1, the frequency-sweeping period of the frequency-sweeping optical signal 1 is T1, and the frequency-sweeping bandwidth is B1.
  • the wavelength variation range of the frequency-sweeping laser 61111 is [ ⁇ 1, ⁇ 2], and the frequency variation range of the output frequency-sweeping optical signal 1 is [f1, f2].
  • the wavelength range of the frequency-sweeping laser 61112 is [ ⁇ 3, ⁇ 4], and the frequency range of the output frequency-sweeping optical signal 2 is [f3, f4].
  • the frequency sweep bandwidths B1 and B2 may be the same or different, and the frequency sweep periods T1 and T2 may be the same or different, but T1/T2 or T2/T1 are positive integers. In the embodiment shown in FIG.
  • the output frequency-sweeping optical signal 1 and frequency-sweeping optical signal 2 satisfy the first scanning frequency as described above.
  • the conditions satisfied by the frequency optical signal and the second frequency-sweeping optical signal For example, the frequency-sweeping optical signal 1 and the frequency-sweeping optical signal 2 satisfy condition 1+condition 2+condition 4+condition 5+condition 6+condition 7.
  • the frequency-sweeping optical signal 1 and the frequency-sweeping optical signal 2 output by the frequency-sweeping laser 61111 and the frequency-sweeping laser 61112 are coupled through the directional waveguide coupler 6121, and output two optical signals, one of which is used as a local oscillator signal, and the other optical signal signal as a detection signal.
  • the power of the two optical signals may be the same or different. In some embodiments, when the powers of the two optical signals are not equal, the optical signal with a relatively small power may be used as a local oscillator signal for coherent reception of the received signal.
  • a relatively high-power optical signal is sent out as a detection signal through the scanner to detect the object to be detected. After the detection signal encounters M objects to be detected, it is reflected to form M echo signals.
  • the M echo signals After the M echo signals arrive at the lidar, they are received by the scanner.
  • the M echo signals and one local oscillator signal enter the 90-degree mixer 6201 for optical mixing to obtain a mixed frequency signal.
  • the two optical signals output after mixing are respectively converted into two analog electrical signals by the first photodetector 6202 and the second photodetector 6203, and then passed through the first analog-to-digital converter 6204 and the second analog-to-digital converter 6205 respectively Transform into two digital electrical signals; the two digital signals enter the signal processor 6206 for processing, and finally output information such as the distance and speed of M detection objects.
  • the detection signal before the detection signal is transmitted, it may be amplified first, and then transmitted.
  • the sending device 610 may further include an optical amplifier (not shown in the figure), such as a semiconductor optical amplifier, an optical fiber amplifier, and the like.
  • the optical amplifier amplifies the detection signal output by the directional waveguide coupler 3, and then transmits it through the scanner.
  • frequency-sweeping optical signals in different frequency ranges are realized by adjusting the wavelength ranges of different frequency-sweeping lasers, which is simple to implement. Due to the introduction of frequency-sweeping optical signals with different slopes, real targets are coherently detected within two time periods of different frequency-sweeping optical signals, which can eliminate false targets. When different frequency-sweeping optical signals have a certain guard bandwidth in the frequency domain (that is, when condition 6 is satisfied), it can prevent unnecessary beat frequency signals from being generated, thereby preventing calculation errors and reducing the calculation speed or distance. the complexity.
  • the transmission signal formed by transmitting frequency multiplexing is used to realize the distinction of multiple targets without increasing the measurement time and maintaining the lidar out-point rate unchanged.
  • the frequency value of the frequency-sweeping optical signal 1 is always smaller than the frequency value of the frequency-sweeping optical signal 2 . Therefore, the frequency-sweeping optical signal 1 and the frequency-sweeping optical signal 2 will not be confused in the 90-degree mixer 6201, so the same receiver can be used for reception. In turn, resource utilization can be improved and costs can be reduced.
  • the waveforms of the scanning frequency optical signal 1 and the scanning frequency optical signal 2 are as shown in (1) in FIG. 15B below. Then, the signal waveform and frequency spectrum in the case of normal rate are shown in (2) in FIG. 15B. The signal waveform and frequency spectrum in the case of too fast rate are shown in (3) in FIG. 15B.
  • the local oscillator signal of frequency-sweeping optical signal 1 is called local oscillator signal 1
  • the echo signal of frequency-sweeping optical signal 1 is called echo signal 1
  • the local oscillator signal of frequency-sweeping optical signal 2 is called local oscillator signal 2.
  • the echo signal of the frequency-swept optical signal 2 is called echo signal 2.
  • FIG. 16 uses frequency multiplexing as an example for description.
  • the frequency-sweeping signal source 611 includes N directly-modulated frequency-sweeping lasers. In FIG. 16 , taking N as 2 as an example, they are the frequency-sweeping laser 61111 and the frequency-sweeping laser 61112 .
  • the multiplexer/demultiplexer component 612 includes three directional waveguide couplers 6121, which are respectively called directional waveguide coupler 6121-1, directional waveguide coupler 6121-2, and directional waveguide coupler 6121-3 for the convenience of distinction.
  • the receiving device 620 may employ two IQ receivers. For simplicity of description, the components in the IQ receiver are not identified anymore.
  • the frequency-sweeping laser 61111 outputs the frequency-sweeping optical signal 1 .
  • the frequency-sweeping laser 61112 outputs the frequency-sweeping optical signal 2 .
  • the frequency-sweeping optical signal 1 is output by the directional waveguide coupler 6121-1 and divided into two parts, one part of the optical signal is transmitted to one of the receivers as a local oscillator signal, and the other part of the optical signal enters the directional waveguide coupler 6121-3.
  • the frequency-sweeping optical signal 2 is output by the directional waveguide coupler 6121-2 and divided into two parts, one part of the optical signal is transmitted to another receiver as a local oscillator signal, and the other part of the optical signal enters the directional waveguide coupler 6121-3.
  • the detection signal output by the directional waveguide coupler 3 is transmitted through the scanner to detect the object to be measured.
  • the sending device 610 may further include an optical amplifier (not shown in the figure), which amplifies the detection signal output by the directional waveguide coupler 3 and then transmits it through the scanner.
  • the detection system may further include a wave division multiplexer, which is used to split the echo signal received from the scanner into two optical signals that enter the two receivers respectively. The processing methods of the two receivers are as described above, and will not be repeated here.
  • the receiving device 620 can also use two I receivers or Q receivers, which does not cause the problem of speed ambiguity, and can reduce the cost of detection.
  • the multiplexer/demultiplexer component includes a wavelength division multiplexer 61211 and a coupler 61212 .
  • the frequency-sweeping optical signals 1-N output by N frequency-sweeping lasers are multiplexed by the wavelength division multiplexer 61211, and the optical signal output by the wavelength division multiplexer 61211 is divided into two paths of light by the coupler, one of which is used as The local oscillator signal is input to the receiver, and the other optical signal is sent out through the scanner as a detection signal.
  • the sending device 610 may further include an optical amplifier (not shown in the figure), which amplifies the detection signal output by the coupler 61212 and then transmits it through the scanner.
  • the signals can be used to simultaneously detect M detection objects to eliminate false targets.
  • the IQ receiver at the receiving end to perform coherent detection on different frequency-sweeping optical signals, the computational complexity of the signal processor is reduced.
  • accurate positioning of multi-target detection objects is achieved without increasing the measurement time, and the out-point rate of the laser radar remains unchanged.
  • the receiving device 620 can also use an I receiver or a Q receiver, which does not cause the problem of speed ambiguity, and can reduce the cost of detection.
  • FIG. 18 is a schematic structural diagram of a possible detection system.
  • the difference between FIG. 18 and the embodiment corresponding to FIG. 15A is that the receiving device 620 in FIG. 15A uses an IQ receiver, and the receiving device 620 in FIG. 18 uses an I receiver or a Q receiver.
  • the problem of velocity ambiguity will not occur, and the detection cost can be reduced.
  • the N frequency-sweeping optical signals in FIG. 19 are generated by performing IQ modulation on the laser signal emitted by the laser, and the frequency-sweeping waveform can be generated by digital signal processing.
  • the frequency sweep signal source 611 includes a laser 1910 , a modulator 1920 , a frequency sweep drive signal source 1930 and two radio frequency amplifiers.
  • the two radio frequency amplifiers are called radio frequency amplifier 1941 and radio frequency amplifier 1942 respectively.
  • FIG. 20 it shows the manner in which the frequency sweep driving signal source generates N frequency sweep signals.
  • the frequency sweep signal 1-the frequency sweep signal N are N frequency sweep signals with different frequencies, which are subjected to different up-conversion processes to obtain the frequency sweep signals whose frequency range satisfies the aforementioned conditions.
  • the frequency-sweeping digital signal is converted into a frequency-sweeping analog signal by taking real and imaginary parts and digital-to-analog conversion processing. After further radio frequency amplification, it is modulated onto the laser signal emitted by the laser. After the frequency-sweeping analog signals of different frequency-sweeping frequency ranges are modulated onto the laser signal, frequency-sweeping optical signals of different frequency-sweeping frequency ranges are obtained.
  • the multiplexer/demultiplexer component 612 includes a coupler 1950 .
  • the coupler 1950 sends the local oscillator signal to the receiving device 620, and transmits the detection signal through the scanner.
  • the detection signal may be amplified first, and then transmitted.
  • the sending device 610 may further include an optical amplifier (not shown in the figure), which amplifies the detection signal output by the coupler 1950 and then transmits it through the scanner.
  • the receiving device 620 may also use an I receiver or a Q receiver, which does not cause the problem of speed ambiguity, and can reduce the cost of detection.
  • the frequency sweep signal source 611 includes N frequency sweep signal transmitting components, which are respectively frequency sweep signal transmitting components 1-N.
  • Each sweep signal transmitting component includes a sweep drive signal source 2101 , a radio frequency amplifier 2102 and a radio frequency amplifier 2103 , a laser 2104 and a modulator 2105 .
  • the frequency sweep driving signal source 2101 generates a frequency sweep signal whose frequency changes periodically, and is amplified by a radio frequency amplifier before being input to the modulator.
  • the multiplexer/demultiplexer component 612 includes a coupler 2106 . It is used to perform beam combination processing on the frequency-sweeping optical signals emitted by N frequency-sweeping signal transmitting components, and then split them to obtain local oscillator signals and detection signals.
  • the coupler 2106 sends the local oscillator signal to the receiving device 620, and transmits the detection signal through the scanner. In some embodiments, before the detection signal is transmitted, it may be amplified first, and then transmitted.
  • the sending device 610 may further include an optical amplifier (not shown in the figure), which amplifies the detection signal output by the coupler 2106 and then transmits it through the scanner.
  • the manner in which the frequency-sweeping driving signal source 2101 generates a frequency-sweeping signal whose frequency changes periodically can be referred to in FIG. 22 .
  • the real and imaginary parts of the digital frequency sweep signal are processed, and then converted into an analog frequency sweep signal through digital-to-analog conversion.
  • the wavelengths of the laser signals emitted by the lasers included in different frequency-sweeping signal emitting components are different.
  • the lasers emit laser signals of different wavelengths, so that the frequency range of the frequency-sweeping optical signals emitted by the N frequency-sweeping signal transmitting components satisfies the conditions shown above.
  • the frequency ranges of the frequency sweep signals generated by the frequency sweep driving signal sources included in different frequency sweep signal transmitting components are different.
  • frequency-sweeping analog electrical signals of different frequency ranges are generated by the frequency-sweeping signal source and modulated onto the laser signal emitted by the laser, so that the frequency range of the frequency-sweeping optical signal emitted by the N frequency-sweeping signal emitting components satisfies the above conditions shown.
  • the wavelengths of the laser signals emitted by the lasers included in different frequency sweeping signal emitting assemblies are different, and the frequency ranges of the frequency sweeping signals generated by the frequency sweeping driving signal sources included in different frequency sweeping signal emitting assemblies are different.
  • frequency-sweeping analog electrical signals of different frequency ranges are generated by frequency-sweeping signal sources, and correspondingly modulated onto laser signals of different wavelengths emitted by N lasers, so that the frequency-sweeping light emitted by N frequency-sweeping signal emitting components The frequency range of the signal satisfies the conditions shown previously.
  • the above scheme generates N frequency-sweeping signals satisfying conditions through digital signal processing, and modulates them onto laser signals to generate N frequency-sweeping optical signals satisfying conditions, so as to detect M detection objects and eliminate false targets.
  • the embodiment of the present application can realize the positioning of multi-target detection objects without increasing the measurement time, and keep the laser radar out-of-point rate unchanged.
  • the receiving device 620 may also use an I receiver or a Q receiver, which does not cause the problem of speed ambiguity, and can reduce the cost of detection.
  • the frequency sweep signal source 611 includes a laser 2301 , an optical frequency comb 2302 , N microring modulators, and N frequency sweep drive signal sources.
  • the N microring modulators are microring modulators 1 to N
  • the N frequency sweeping driving signal sources are respectively sweeping driving signal sources 1 to N.
  • the principle of the sweeping signal generated by the sweeping driving signal source can be referred to as shown in FIG. 22 , and will not be repeated here.
  • Laser 2301 emits laser signals.
  • the optical frequency comb 2302 processes the laser signal to obtain optical signals of N wavelengths.
  • the N sweeping drive signal sources are connected to the N microring modulators in one-to-one correspondence, and the N microring modulators are sequentially arranged in series on the optical paths of the optical signals of N wavelengths.
  • the N microring modulators correspond to the N wavelengths one by one, and the frequency ranges of the frequency sweep signals output by different frequency sweep driving signal sources are different.
  • the multiplexer/demultiplexer component 612 may include a directional waveguide coupler 2303 for splitting the optical signal output by the microring modulator N to obtain a local oscillator signal and a detection signal.
  • the directional waveguide coupler 2303 sends the local oscillator signal to the receiving device 620, and transmits the detection signal through the scanner.
  • the sending device 610 may further include a fiber amplifier (not shown in the figure), which amplifies the detection signal output by the directional waveguide coupler 2303, and then transmits it through the scanner.
  • N frequency-sweeping driving signal sources are used to generate frequency-sweeping analog electrical signals in different frequency ranges, and the laser signal is converted into light of multiple frequencies through an optical frequency comb, which can also be understood as light of different wavelengths.
  • N frequency-sweeping analog electrical signals of different frequency ranges are modulated onto optical signals of different wavelengths through N microring modulators, and the frequency ranges of the N frequency-sweeping optical signals generated meet the conditions shown above. False targets can be eliminated by transmitting N frequency-sweeping optical signals satisfying conditions to detect M detection objects.
  • Two adjacent frequency-sweeping analog electrical signals have a certain guard bandwidth in the frequency domain, so that two adjacent frequency-sweeping optical signals have a certain guard bandwidth in the frequency domain, so as to prevent unnecessary beat frequency signals from being generated.
  • the embodiment of the present application can realize the positioning of multi-target detection objects without increasing the measurement time, and keep the laser radar out-of-point rate unchanged.
  • the receiving device 620 may also use an I receiver or a Q receiver, which does not cause the problem of speed ambiguity, and can reduce the cost of detection.
  • the frequency-sweeping signal source 611 includes N frequency-sweeping lasers, which are respectively frequency-sweeping lasers 1-N.
  • the polarization directions of the frequency-sweeping optical signals generated by different frequency-sweeping lasers are different.
  • the N frequency-sweeping lasers generate N frequency-sweeping optical signals, and the N optical signals satisfy the aforementioned conditions.
  • the multiplexer/demultiplexer component 612 includes a polarization beam combiner (polarization beam combiner, PBC) 2401 and a polarization maintaining coupler 2402 .
  • the polarization beam combiner 2401 combines the N frequency-sweeping optical signals based on the polarization directions of the N frequency-sweeping optical signals to obtain radar transmission signals.
  • the polarization maintaining coupler 2402 splits the radar transmission signal to obtain a local oscillator signal and a detection signal.
  • the polarization maintaining coupler 2402 sends the local oscillator signal to the receiving device 620, and transmits the detection signal through the scanner.
  • the sending device 610 may further include a polarization-maintaining amplifier (not shown in the figure), which amplifies the detection signal output by the polarization-maintaining coupler 2402 and then transmits it through the scanner.
  • the frequency-sweeping optical signals with different frequency-sweeping slopes are polarized multiplexed to form a transmission signal to detect M detection objects, which can eliminate false targets without increasing the measurement time, and maintain the lidar out-point rate unchanged.
  • the receiving device 620 can also use an I receiver or a Q receiver, which does not cause the problem of speed ambiguity, and can reduce the cost of detection.
  • the present application provides a lidar detection method, please refer to the introduction of FIG. 25 .
  • This detection method can be applied to the detection system shown in any of the above-mentioned embodiments in FIG. 15A to FIG. 24 . It can also be understood that the detection method can be implemented based on the detection system shown in any one of the above-mentioned embodiments in FIG. 15A to FIG. 24 .
  • FIG. 25 it is a schematic flowchart of a lidar detection method provided by the present application.
  • the detection method includes the following steps:
  • N is an integer greater than 1, and the frequency-sweeping slope of the first frequency-sweeping optical signal among the N frequency-sweeping optical signals is different from that of the second frequency-sweeping optical signal in the first time period.
  • the sign of the frequency sweep slope is opposite, or the frequency sweep slope of the first frequency sweep optical signal is 0 and the frequency sweep slope of the second frequency sweep optical signal is not 0; the frequencies of the N frequency sweep optical signals are different .
  • the local oscillator signal is used for coherent detection with the echo signal of the detection signal to obtain location information of the detection object.
  • the detection method may also include:
  • the first frequency-sweeping optical signal and the second frequency-sweeping optical signal are periodic frequency-sweeping optical signals.
  • the signal period of the first frequency-sweeping optical signal is M times the signal period of the second frequency-sweeping optical signal, or the signal period of the second frequency-sweeping signal is the M times the signal period of the first frequency-sweeping optical signal, where M is a positive integer.
  • the signal period of the first frequency-sweeping optical signal is K times the detection period of the laser radar, or the signal period of the second frequency-sweeping optical signal is K times the detection period of the laser radar. K times the detection period, K is a positive integer.
  • the signal period of the first frequency-sweeping optical signal is greater than or equal to the signal period of the second frequency-sweeping signal; in one signal period of the first frequency-sweeping optical signal, the first The sweep slope of a frequency sweep signal in the first time period is opposite to the sign of the sweep slope in the second time period; the sweep slope of the second frequency sweep signal in the first time period is the same as that in the second time period The sign of the frequency sweep slope is opposite; the frequency sweep slope of the first frequency sweep signal in the first time period is different from the frequency sweep slope of the second frequency sweep signal in the second time period, and the The frequency sweep slope of the second frequency sweep signal in the first time period is different from the frequency sweep slope of the first frequency sweep signal in the second time period.
  • the minimum frequency difference between the first frequency-sweeping optical signal and the second frequency-sweeping optical signal is related to a receiving bandwidth of the antenna.
  • the minimum frequency difference between the first frequency-sweeping optical signal and the second frequency-sweeping optical signal satisfies the following conditions:
  • f 1 represents the frequency sweep range of the first frequency sweep optical signal
  • f 2 represents the frequency sweep range of the second frequency sweep optical signal
  • fR 1 represents the relative echo signal of the first frequency sweep optical signal
  • fR 2 represents the local oscillator of the echo signal of the second frequency-sweeping optical signal relative to the second frequency-sweeping optical signal
  • fOE represents the receiving bandwidth of the antenna.
  • the first frequency sweep signal and the second frequency sweep signal satisfy:
  • round () represents the rounding operation
  • K 1 represents the absolute value of the frequency sweep slope of the first frequency sweep signal within the first time period
  • K 2 represents the second frequency sweep slope within the first time period.
  • R min represents the minimum detectable distance of the lidar
  • c represents the speed of light.
  • the waveform of the first frequency-sweeping optical signal includes at least one of a triangular wave, a trapezoidal wave, and a sawtooth wave; when the frequency-sweeping slope of the second frequency-sweeping optical signal is not 0,
  • the waveform of the second frequency-sweeping optical signal includes at least one of a triangular wave, a trapezoidal wave, and a sawtooth wave.
  • the wavelength ranges of the N frequency-sweeping optical signals are different, or the polarization directions of the N frequency-sweeping optical signals are different.

Landscapes

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

Abstract

一种激光雷达的发送装置、探测系统以及探测方法，实现在多目标的情况下能够排除虚假目标。通过引入不同的斜率的扫频光信号，不同的扫频光信号存在扫频斜率符号相反的时间段，并且扫频斜率的绝对值也不相等。多个真实的目标在不同的扫频光信号分别对应的至少两个时间段内进行相干探测。由于不同的扫频光信号计算得到的真实目标的距离和速度不会发生变化，而虚假目标的距离和速度会发生变化，因此通过多个扫频光信号的相干探测的相同结果来确定真实目标的距离和速度，从而可以消除虚拟目标，并且不会增加探测时间。并且即使使用I接收机或者Q接收机也不会出现速度模糊的情况，进一步可以降低成本。

Description

一种激光雷达的发送装置、探测系统以及探测方法
相关申请的交叉引用
本申请要求在2021年12月29日提交中国专利局、申请号为202111637896.0、申请名称为“一种激光雷达的发送装置、探测系统以及探测方法”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及光通信技术领域，特别涉及一种激光雷达的发送装置、探测系统以及探测方法。
背景技术
相干的激光雷达，可以利用线性调频信号的特征，使得本振信号与回波信号拍频产生一个随探测物体的距离和速度变化的混频信号，根据混频信号的频率大小可以计算被探测物体的距离信息和速度信息。虽然激光雷达的指向性较高，发射光斑较小，但是当发射光到达较远距离的物体时，由于距离较远导致光斑发散，从而发出去的光信号会照射到多个物体上而产生多个回波信号。多个回波信号分别与本振信号相干检测后，定位出多个目标，无法从多个目标排除虚假目标。
发明内容
本申请实施例提供一种激光雷达的发送装置、探测系统以及探测方法，实现在多目标的情况下能够排除虚假目标。
第一方面，本申请实施例提供一种激光雷达的发送装置，包括扫频信号源、合分波组件；其中，扫频信号源发射N个扫频光信号，N为大于1的整数，在第一时间段内N个扫频光信号中第一扫频光信号的扫频斜率与第二扫频光信号的扫频斜率的符号相反且第一扫频光信号的扫频斜率的绝对值与第二扫频光信号的扫频斜率的绝对值不同，或者第一扫频光信号的扫频斜率不为0且第二扫频光信号的扫频斜率为0；N个扫频光信号的频率不同；合分波组件将N个扫频光信号进行合波得到雷达发射信号，并将雷达发射信号进行分光处理得到本振信号和探测信号，将探测信号通过天线发射，将本振信号发送给激光雷达的接收装置。通过上述方案，采用不同的斜率的扫频光信号的引入，使得多个真实的目标在不同的扫频光信号分别对应的至少两个时间段内进行相干探测。由于不同的扫频光信号计算得到的真实目标的距离和速度不会发生变化，而虚假目标的距离和速度会发生变化，因此通过多个扫频光信号的相干探测的相同结果来确定真实目标的距离和速度，从而可以消除虚拟目标，并且不会增加探测时间。
在一种可能的设计中，第一扫频光信号和第二扫频光信号为周期性的扫频光信号。
在一种可能的设计中，第一扫频光信号的信号周期是第二扫频光信号的信号周期的M倍，或者第二扫频信号的信号周期是第一扫频光信号的信号周期的M倍，M为正整数。
在一种可能的设计中，第一扫频光信号的信号周期为激光雷达的探测周期的K倍，或 者第二扫频光信号的信号周期为激光雷达的探测周期的K倍，K为正整数。上述设计中，在一个信号周期进行多次探测，可以提高探测的效率，减少探测时延。
在一种可能的设计中，在一个目标信号周期中，所述第一扫频信号在第一时间段内的扫频斜率与第二时间段内的扫频斜率的符号相反；所述第二扫频信号在第一时间段的扫频斜率与第二时间段内的扫频斜率的符号相反；所述第一时间段内所述第一扫频信号的扫频斜率与所述第二时间段内所述第二扫频信号的扫频斜率不相同，以及所述第一时间段内所述第二扫频信号的扫频斜率与所述第二时间段内所述第一扫频信号的扫频斜率不相同。其中，所述目标信号周期为所述第一扫频光信号的信号周期和所述第二扫频光信号的信号周期中的最大信号周期。上述设计中，两个时间段内的扫频光信号的扫频斜率均不相同，防止不同扫频光信号与本振信号拍频得到的中频信号相同，进一步提高消除虚假目标的准确度。
在一种可能的设计中，所述第一扫频光信号与所述第二扫频光信号的最小频率差与所述天线的接收带宽相关。上述设计中，基于天线的接收带宽来确定各个扫频光信号的频率范围，可以减少产生不需要的拍频频率信号，提高计算结果的准确度。并且无需使用计算复杂度的算法来区分消除不需要的拍频频率信号，进而可以降低计算复杂度，减少使用的处理资源。
在一种可能的设计中，所述第一扫频光信号与所述第二扫频光信号的最小频率差满足如下条件：
min(|f 1-f 2|)>|fR 1|+|fR 2|+fOE；
其中，f 1表示所述第一扫频光信号的扫频范围，f 2表示所述第二扫频光信号的扫频范围，fR 1表示所述第一扫频光信号的回波信号相对于所述第一扫频光信号的本振信号的频率频移量的最大值，fR 2表示所述第二扫频光信号的回波信号相对于所述第二扫频光信号的本振信号的频率频移量的最大值，fOE表示所述天线的接收带宽。上述设计提供确定扫频光信号的频率差的具体方式，实现简单。并且可以防止产生不需要的拍频频率信号，提高计算结果的准确度。并且无需使用计算复杂度的算法来区分消除不需要的拍频频率信号，进而可以降低计算复杂度，减少使用的处理资源。
在一种可能的设计中，所述第一扫频信号和所述第二扫频信号满足：
Figure PCTCN2022139889-appb-000001
或者
Figure PCTCN2022139889-appb-000002
其中，round()表示四舍五入取整运算，K 1表示所述第一时间段内所述第一扫频信号的扫频斜率的绝对值，K 2表示所述第一时间段内所述第二扫频信号的扫频斜率的绝对值，R min表示激光雷达的最小可探测距离，c表示光速。上述设计中，不同扫频光信号的扫频斜率满足如上所示的条件，结合最小可探测距离来确定不同扫频光信号的扫频斜率大小，可以防止不同扫频光信号的扫频斜率差距较小导致的排除虚假目标的准确度降低，进一步提高排除虚假目标的准确度。
在一种可能的设计中，所述第一扫频光信号的波形包括三角波、梯形波、锯齿波中的至少一种；所述第二扫频光信号的扫频斜率不为0时，所述第二扫频光信号的波形包括三角波、梯形波、锯齿波中的至少一种。
在一种可能的设计中，所述N个扫频光信号的波长变化范围不同，或者所述N个扫频 光信号的偏振方向不同。
在一种可能的设计中，所述扫频信号源包括N个扫频激光器，所述扫频激光器用于发射波长周期变化的扫频光信号。上述设计中，通过调整不同扫频激光器发射的光信号的波长来实现不同的扫频激光器发射的扫频光信号的频率范围不同，使得扫频斜率满足要求。
在一种可能的设计中，扫频信号源包括激光器、调制器、射频放大器和扫频驱动信号源；扫频驱动信号源，用于产生N个频率周期变化的扫频信号，并经过射频放大器放大后输入调制器；激光器，用于发射激光信号；调制器，用于将N个经过放大的扫频信号调制到激光信号上得到N个扫频光信号。上述设计中，提供一种采用外调方式产生N个满足要求的扫频光信号的方式。通过数字信号处理的方式来生成满足频率要求的扫频电信号，然后再调制到激光器发射的激光信号上，实现简单。
在一种可能的设计中，所述扫频信号源包括N个扫频信号发射组件；所述N个扫频光信号发射组件中任一扫频信号发射组件包括扫频驱动信号源、激光器、调制器以及射频放大器；所述扫频驱动信号源，用于产生一个频率周期变化的扫频信号，并经过所述射频放大器放大后输入所述调制器；所述激光器，用于发射激光信号；所述调制器，用于将经过放大的扫频信号调制到所述激光信号上得到一个扫频光信号；其中，不同扫频信号发射组件包括的激光器发射的激光信号的波长不同，和/或不同扫频信号发射组件包括的扫频驱动信号源产生的扫频信号的频率范围不同。上述设计中，提供一种使用N个扫频信号发射组件来产生N个扫频光信号的方式，较容易地产生N个满足要求的扫频光信号。
在一种可能的设计中，所述扫频信号源包括激光器、光频梳、N个微环调制器以及N个扫频驱动信号源；所述激光器，用于发射激光信号；光频梳，用于将所述激光信号进行处理得到N个波长的光信号；N个扫频驱动信号源与所述N个微环调制器一一对应连接，所述N个微环调制器在所述N个波长的光信号的光路依次串联排布；第一微环调制器，用于将第一扫频驱动信号源输出的频率范围周期变化的扫频信号调制到所述第一微环调制器对应波长的光信号上；其中，N个微环调制器与所述N个波长一一对应，不同扫频驱动信号源输出的扫频信号的频率范围不同。上述设计中，提供一种结合光频梳和N个微环调制器来产生N个扫频光信号的方式，实现较简单。
在一种可能的设计中，所述合分波组件包括耦合器，比如定向耦合器。
在一种可能的设计中，N个扫频光信号的偏振方向不同，所述合分波组件包括偏振合束器和保偏耦合器；所述偏振合束器，用于基于所述N个扫频光信号的偏振方向对所述N个扫频光信号进行合束得到雷达发射信号；所述保偏耦合器，用于将所述雷达发射信号进行分光得到所述本振信号和所述探测信号。
第二方面，本申请实施例提供一种激光雷达的探测系统，包括第一方面或者第一方面的任一设计所述的激光雷达的发送装置，以及激光雷达的接收装置。所述接收装置，用于接收来自所述发送装置的本振信号和所述发送装置发送的探测信号的回波信号，并将所述回波信号和所述本振信号进行混频处理生成混频信号；根据所述混频信号获得探测物体的定位信息。
在一种可能的设计中，接收装置可以采用IQ探测方式来获取探测物体的定位信息。
在一种可能的设计中，接收装置包括90度混频器、第一光电探测器、第二光电探测器、第一模数转换器、第二模数转换器和信号处理器；90度混频器，用于对从天线接收的探测信号的回波信号和本振信号进行混频处理生成混频信号，将混频信号分为第一路信号 和第二路信号，并将第一路信号发送给第一光电探测器，以及将第二路信号发送给第二光电探测器；第一光电探测器，用于对第一路信号进行探测处理后，输出给第一模数转换器进行模数转换；第二光电探测器，用于对第二路信号进行探测处理后，输出给第二模数转换器进行模数转换；信号处理器，用于对第一模数转换器输出的数字信号和第二模数转换器输出的数字信号进行处理，获得探测物体的定位信息。上述设计中，通过使用IQ探测的方式，可以区分正负频率信息，使得处理算法简单，对信号处理器的处理性能要求较低。
在一种可能的设计中，接收装置可以采用I探测方式或者Q探测方式来获取探测物体的定位信息。
在一种可能的设计中，接收装置包括180度混频器、第三光电探测器、第三模数转换器和信号处理器；180度混频器，用于对从天线接收的探测信号的回波信号和本振信号进行混频处理生成混频信号，将混频信号发送给第三光电探测器；第三光电探测器，用于对混频信号进行探测处理后，输出给第三模数转换器进行模数转换；信号处理器，用于对第三模数转换器输出的数字信号进行处理，获得探测物体的定位信息。上述设计中使用I接收机或者Q接收机，通过多个扫频光信号复用形成发射信号，由于真实目标的距离和速度不会发生变化，可以针对每个扫频光信号的本振信号与回波信号进行拍频计算混频信号，然后通过不同的情况下对应的公式分别确定距离的频率分量和速度的频率分量，也就是说基于每个扫频光信号可以得到计算三个结果。则多个计算结果中相同的结果即为最终的计算结果，可以解决现有采用I接收机或者Q接收机由于无法多个情况下对应的公式对应的计算结果哪个为正确结果导致探测出现的速度模糊的问题。
第三方面，本申请实施例提供一种基于激光雷达的探测方法，包括：发射N个扫频光信号，N为大于1的整数，在第一时间段内所述N个扫频光信号中第一扫频光信号的扫频斜率与第二扫频光信号的扫频斜率的符号相反，或者所述第一扫频光信号的扫频斜率为0且所述第二扫频光信号的扫频斜率不为0；所述N个扫频光信号的频率不同；将所述N个扫频光信号进行合波得到的雷达发射信号，并将所述雷达发射信号分为本振信号和探测信号，将所述探测信号通过天线发射；所述本振信号用于与所述探测信号的回波信号进行相干探测获取探测物体的定位信息。
一种可能的设计中，探测方法还可以包括：从所述天线接收所述探测信号的回波信号，并将所述回波信号和所述本振信号进行混频处理生成混频信号；根据所述混频信号获得探测物体的定位信息。
在一种可能的设计中，所述第一扫频光信号和所述第二扫频光信号为周期性的扫频光信号。
在一种可能的设计中，所述第一扫频光信号的信号周期是所述第二扫频光信号的信号周期的M倍，或者所述第二扫频信号的信号周期是所述第一扫频光信号的信号周期的M倍，M为正整数。
在一种可能的设计中，所述第一扫频光信号的信号周期为所述激光雷达的探测周期的K倍，或者所述第二扫频光信号的信号周期为所述激光雷达的探测周期的K倍，K为正整数。
在一种可能的设计中，在一个目标信号周期中，所述第一扫频光信号在第一时间段内的扫频斜率与第二时间段内的扫频斜率的符号相反；所述第二扫频光信号在第一时间段的扫频斜率与第二时间段内的扫频斜率的符号相反；所述第一时间段内所述第一扫频光信号 的扫频斜率与所述第二时间段内所述第二扫频光信号的扫频斜率不相同，以及所述第一时间段内所述第二扫频光信号的扫频斜率与所述第二时间段内所述第一扫频光信号的扫频斜率不相同。其中，所述目标信号周期为所述第一扫频光信号的信号周期和所述第二扫频光信号的信号周期中的最大信号周期。
在一种可能的设计中，所述第一扫频光信号与所述第二扫频光信号的最小频率差与所述天线的接收带宽相关。
在一种可能的设计中，所述第一扫频光信号与所述第二扫频光信号的最小频率差满足如下条件：
min(|f 1-f 2|)>|fR 1|+|fR 2|+fOE；
其中，f 1表示所述第一扫频光信号的扫频范围，f 2表示所述第二扫频光信号的扫频范围，fR 1表示所述第一扫频光信号的回波信号相对于所述第一扫频光信号的本振信号的频率频移量的最大值，fR 2表示所述第二扫频光信号的回波信号相对于所述第二扫频光信号的本振信号的频率频移量的最大值，fOE表示所述天线的接收带宽。
在一种可能的设计中，所述第一扫频信号和所述第二扫频信号满足：
Figure PCTCN2022139889-appb-000003
或者
Figure PCTCN2022139889-appb-000004
其中，round()表示四舍五入取整运算，K 1表示所述第一时间段内所述第一扫频信号的扫频斜率的绝对值，K 2表示所述第一时间段内所述第二扫频信号的扫频斜率的绝对值，R min表示激光雷达的最小可探测距离，c表示光速。
在一种可能的设计中，所述第一扫频光信号的波形包括三角波、梯形波、锯齿波中的至少一种；所述第二扫频光信号的扫频斜率不为0时，所述第二扫频光信号的波形包括三角波、梯形波、锯齿波中的至少一种。
在一种可能的设计中，所述N个扫频光信号的波长变化范围不同，或者所述N个扫频光信号的偏振方向不同。
本申请在上述各方面提供的实现的基础上，还可以进行进一步组合以提供更多实现。
上述第二方面和第三方面的有益效果可以参见第一方面的相关描述。
附图说明
为了更清楚地说明本申请实施例中的技术方案，下面将对实施例描述中所需要使用的附图作简要介绍。
图1为一种激光雷达的架构示意图；
图2为一种本振信号、回波信号以及混频信号的示意图；
图3为一种混频信号的频谱示意图；
图4为一种产生的虚假目标的示意图；
图5为一种混频信号的波形示意图；
图6为本申请实施例提供的激光雷达的探测系统架构示意图；
图7为本申请实施例提供的扫频光信号的波形示意图；
图8为本申请实施例提供的第一扫频光信号和第二扫频光信号的波形示意图；
图9为本申请实施例提供的两个探测目标的情况下的混频信号频谱示意图；
图10为本申请实施例提供的距离-速度解算原理示意图；
图11为本申请实施例提供的偏振复用方式下扫频光信号输出波形示意图；
图12为本申请实施例提供的探测周期与信号周期的关系示意图；
图13为本申请实施例提供的一种接收装置620的结构示意图；
图14为本申请实施例提供的另一种接收装置620的结构示意图；
图15A为本申请实施例提供的一种探测系统架构示意图；
图15B为本申请实施例提供的两个扫频光信号的波形以及一个探测目标的情况下混频信号频谱示意图；
图16为本申请实施例提供的一种探测系统架构示意图；
图17为本申请实施例提供的一种探测系统架构示意图；
图18为本申请实施例提供的一种探测系统架构示意图；
图19为本申请实施例提供的一种探测系统架构示意图；
图20为本申请实施例提供的扫频驱动信号源产生方式示意图；
图21为本申请实施例提供的一种探测系统架构示意图；
图22为本申请实施例提供的扫频驱动信号源产生方式示意图；
图23为本申请实施例提供的一种探测系统架构示意图；
图24为本申请实施例提供的一种探测系统架构示意图；
图25为本申请实施例提供的一种激光雷达的探测方法流程示意图。
具体实施方式
下面将结合附图，对本申请实施例进行详细描述。
以下，对本申请中的部分用语进行解释说明。需要说明的是，这些解释是为了便于本领域技术人员理解，并不是对本申请所要求的保护范围构成限定。
1)本申请涉及的术语“至少一个”，是指一个，或一个以上，即包括一个、两个、三个及以上；“多个”，是指两个，或两个以上，即包括两个、三个及以上。另外，需要理解的是，在本申请的描述中，“第一”、“第二”等词汇，仅用于区分描述的目的，而不能理解为指示或暗示相对重要性，也不能理解为指示或暗示顺序。“和/或”，描述关联对象的关联关系，表示可以存在三种关系，例如，A和/或B，可以表示：单独存在A，同时存在A和B，单独存在B的情况，其中A,B可以是单数或者复数。字符“/”一般表示前后关联对象是一种“或”的关系。“以下至少一项(个)”或其类似表达，是指的这些项中的任意组合，包括单项(个)或复数项(个)的任意组合。例如，a,b,或c中的至少一项(个)，可以表示：a,b,c,a-b,a-c,b-c,或a-b-c，其中a,b,c可以是单个，也可以是多个。
2)扫频信号，是指频率随时间线性变化的信号。
3)扫频波形：扫频信号进行扫频的轨迹。
4)扫频斜率，单位时间内扫频信号的频率变化量，单位Hz/s。
扫描斜率的符号：当扫描斜率的符号为正时，频率随时间增加。当扫描斜率的符号为负时，频率随时间减小。当扫描斜率的符号为零时，频率随时间不发生变化。两个扫描斜率的符号相反是指，其中一个扫频斜率的符号为正，另一个扫频斜率的符号为负。
5)保护带宽，是指当信号采用频率复用时，信号与信号之间存在一定的频率范围，在这个范围内不加载任何信号，以防止不同频率的信号相互之间产生干扰。
6)雷达发射信号，是由一个或多个扫频信号生成，并进行频率复用后，可以由发射天线发射出去的信号。雷达发射信号一般为光信号。
7)回波信号：发射信号到达探测物体后，反射回来的信号。回波信号一般为光信号。
8)激光雷达的最小可探测距离：一些激光雷达存在盲区，距离激光雷达较近的物体无法被探测，比如1米等，该盲区的最小距离即为激光雷达的最小可探测距离。一些激光雷达不存在盲区，但由于一些物体距离激光雷达较近，由于处理器精度或者算法的限制，激光雷达发射探测信号后，较近的物体发射回波信号后，激光雷达无法通过回波信号准确定位到该物体的准确位置。因此可以准确定位的最小距离即为激光雷达的最小可探测距离。
本申请应用于激光雷达。激光雷达可以安装在车辆上、船上或者其它机器上。参见图1所示，激光雷达通过扫频信号源发射扫频光信号，扫频光信号照射到探测物体后会被物体反射，反射回来的回波信号可被激光雷达的接收端接收。从而激光雷达的接收端根据回波信号与本振信号进行拍频产生一个随探测物体的距离和速度变化的中频信号，根据中频信号的频率大小可以计算被测物体的距离、速度和反射率等信息。
如背景技术所述，对于距离较远的物体，激光雷达的光斑会发生发散，从而发出去的光信号会产生多个探测目标的回波信号。比如，参见图2所示，以两个探测目标为例，两个回波信号与本振信号相干探测后产生多个混频信号。如图2所示，回波信号1与本振信号进行相干探测，产生混频信号1；回波信号2与本振信号进行相干探测，产生混频信号2。从图2中可以看到，可以将时间分为时间段1和时间段2。不同时间段中发射信号或回波信号的扫频斜率不一样。分别对时间段1和对时间段2的信号做傅里叶变换，可以得到如图3所示的频谱图。当仅有回波信号1时，图3中时间段1的信号频谱只有频率分量1，时间段2的信号频谱只有频率分量3。
进一步地，根据时间段1的频率分量1、频率分量2以及时间段2的频率分量3、频率分量4可以确定探测目标的距离相关频率和速度相关频率。然后进一步根据距离相关频率计算探测目标的距离，根据速度相关频率计算探测目标的速度。由于时间段1的频率分量有2个，时间段2的频率分量有2个，因此经过组合可以计算得到4个探测目标的距离和速度。
以IQ接收机为例，时间段1的频率分量和时间段2的频率分量与距离相关频率和速度相关频率关系满足如下公式(1)：
f 1＝-f R+f D；f 2＝f R+f D     公式(1)
其中，f 1表示时间段1的频率分量，f 2表示时间段2的频率分量，f R表示距离相关频率，f D表示速度相关频率。
进一步地，f R和f D可以通过如下公式(2)来计算。
Figure PCTCN2022139889-appb-000005
探测目标的距离可以通过如下公式(3)来确定，探测目标的速度可以通过如下公式(4)来确定。
Figure PCTCN2022139889-appb-000006
其中，R表示探测目标与激光雷达的距离，B表示发射的光信号的扫频带宽。
c是光速，T是一个时间段的时长，比如时间段1或者时间段2。
Figure PCTCN2022139889-appb-000007
其中，λ表示光波长，V表示探测目标的移动速度。
则通过如上公式(2)-公式(4)可以确定，V、R与f 1和f 2的关系，可以参见公式(5)所示。
Figure PCTCN2022139889-appb-000008
结合上述公式(5)，确定速度V与距离R以及f 1和f 2的关系曲线，可以参见图4所示。从图4可以看出，由于无法区分频率分量1～4中，哪两个分量来自混频信号1，哪两个分量来自混频信号2，因此无法获得两个探测目标的准确信息。应理解的是，在采用I接收机或者Q接收机时，也会存在上述无法区分多探测目标的问题。
一些场景中，在使用I接收机或者Q接收机的情况下，某个探测目标的移动速度较快，可能会出现计算的探测目标的速度模糊的问题。例如，图5中(1)-(3)所示为三种可能的情况下本振信号和回波信号的频率变化示意图。在图5中(1)所示的第一种可能的情况下，采用I接收机或者Q接收机进行探测时，时间段1的混频信号和时间段2的混频信号可以参见图5中(4)所示。在采用IQ接收机进行探测时，时间段1的混频信号和时间段2的混频信号可以参见图5中(7)所示，IQ接收机探测可以区分正负频率。在采用I接收机或者Q接收机进行探测，由于I接收机或者Q接收机无法区分正负频率，因此理论上时间段1的频率分量和时间段2的频率分量与距离相关频率和速度相关频率关系应满足如下公式(6)所示的条件。
f 1＝f R-f D；f 2＝f R+f D       公式(6)
在图5中(2)所示第二种可能的情况下，采用I接收机或者Q接收机进行探测时，时间段1的混频信号和时间段2的混频信号可以参见图5中(5)所示。采用IQ接收机进行探测时，时间段1的混频信号和时间段2的混频信号可以参见图5中(8)所示，IQ接收机探测可以区分正负频率。在采用I接收机或者Q接收机进行探测，由于I接收机或者Q接收机无法区分正负频率，因此理论上时间段1的频率分量和时间段2的频率分量与距离相关频率和速度相关频率关系应满足如下公式(7)所示的条件。
f 1＝-f R+f D；f 2＝f R+f D      公式(7)
在图5中(3)所示的第三种可能的情况下，采用I接收机或者Q接收机进行探测时，时间段1的混频信号和时间段2的实际混频信号可以参见图5中(6)所示。采用IQ接收机情况下时间段1的混频信号和时间段2的混频信号可以参见图5中(9)所示，IQ接收机探测可以区分正负频率。在采用I接收机或者Q接收机进行探测，由于I接收机或者Q接收机无法区分正负频率，因此理论上时间段1的频率分量和时间段2的频率分量与距离相关频率和速度相关频率关系应满足如下公式(8)所示的条件。
f 1＝f R-f D；f 2＝-f R-f D      公式(8)
基于此，在采用I接收机或者Q接收机进行探测时，如果采用公式(6)所示的方式来计算得到的频率f 1和f 2，可能会存在计算的结果与实际混频信号的频率不相符的情况，导致计算的速度和距离不准确。如果采用公式(6)、(7)和(8)所示的方式分别计算得到频率f 1和f 2，导致无法区分哪个计算结果是准确的。
基于此，本申请提供一种激光雷达的发送装置、测量装置以及探测方法，可以实现多 目标同时探测，并且不会增加探测时长，探测结果较准确，即使采用I接收机或者Q接收机也不会出现速度模糊的问题。本申请实施例中，探测物体也称为反射物，探测物体可以是天线扫描方向上的任何物体，例如，可以是人、山、车辆、树木、桥梁等等。本申请实施例涉及天线包括发射光信号的发射天线和接收光信号的接收天线，也可以称为扫描器，用于发射光信号和接收光信号。
参见图6所示为一种激光雷达的探测系统结构示意图。探测系统600中包括发送装置610和接收装置620。该探测系统可以应用于测距设备或者测速设备上，比如可以应用于FMCW激光雷达、激光测速仪、激光测距仪、光学相干断层扫描(optical coherence tomography，OCT)设备或者光频域反射计(optical frequency domain reflectometer，OFDR)设备等。
发送装置610中可以包括扫频信号源611和合分波组件612。扫频信号源611发射N个扫频光信号。N为大于1的整数。扫频信号源可以采用激光器直调(也可以称为内调)的方式产生，也可以采用调制器对激光器产生的光信号进行外调的方式产生。后续对扫频信号源可以采用的结构进行详细说明，此处不再赘述。
N个扫频信号中至少包括两个扫频波形不同的扫频光信号。N个扫频光信号的频率范围不同。为了便于区分，将该两个扫频信号称为第一扫频光信号和第二扫频光信号。
第一种可能的实现方式中，第一扫频光信号与第二扫频光信号至少满足如下条件1和条件2：
条件1，第一扫频光信号与第二扫频光信号之间至少包括扫频斜率符号相反的时间段。本文将该时间段称为第一时间段。可以理解为，在该第一时间段内第一扫频光信号的扫频斜率与第二扫频光信号的扫频斜率的符号相反。
条件2，在第一时间段内第一扫频光信号的扫频斜率的绝对值与第二扫频光信号的扫频斜率的绝对值不同。
第二种可能的实现方式中，第一扫频光信号与第二扫频光信号满足如下条件3。
条件3，存在一定的时间段第一扫频光信号与第二扫频光信号中其中一个扫频光信号的扫频斜率为0，另外一个扫频光信号的扫频斜率不为0。比如第一时间段内第一扫频光信号的扫频斜率为0，第二扫频光信号的扫频斜率不为0。或者第一时间段内第一扫频光信号的扫频斜率不为0，第二扫频光信号的扫频斜率为0。
一些可能的实施例中，N个扫频光信号之间还满足如下条件4-条件7中的至少一项。
条件4，N个扫频光信号均为周期性的扫频光信号，或者说某个扫频光信号为恒定频率信号，即该扫频光信号的扫频斜率为0。一些实施例中，N个扫频光信号之间信号周期满足倍数关系，倍数也可以为1，即扫频光信号的信号周期相等。以第一扫频光信号和第二扫频光信号为例，第一扫频光信号和第二扫频光信号均为周期性的扫频光信号。示例性地，第一扫频光信号与第二扫频光信号的信号周期之间满足倍数关系。比如第一扫频光信号的信号周期是第二扫频光信号的信号周期的M倍，或者第二扫频光信号的信号周期是第一扫频光信号的信号周期的M倍。M可以为1，也可以为大于1的整数。
条件5，一个目标信号周期中，第一扫频光信号和第二扫频光信号存在扫频斜率符号相反的两个时间段，即可以理解，除上述第一时间段第一扫频光信号和第二扫频光信号的扫频斜率符号相反以外，还存在至少一个时间段第一扫频光信号和第二扫频光信号的扫频斜率符号相反。为了便于区分，将除第一时间段以外的时间段称为第二时间段。这里所说 的一个目标信号周期是指第一扫频光信号和第二扫频光信号的信号周期最大值。以第一扫频光信号的信号周期大于或者等于所述第二扫频信号的信号周期为例。在第一扫频光信号的信号周期中，第一扫频信号在第一时间段内的扫频斜率与第二时间段内的扫频斜率的符号相反；第二扫频信号在第一时间段的扫频斜率与第二时间段内的扫频斜率的符号相反；第一时间段内第一扫频信号的扫频斜率与第二时间段内第二扫频信号的扫频斜率不相同，以及第一时间段内第二扫频信号的扫频斜率与第二时间段内第一扫频信号的扫频斜率不相同。
条件6，N个扫频光信号中频率上相邻近的两个扫频光信号之间具有保护带宽。保护带宽的设置与天线的接收带宽相关。以第一扫频光信号与第二扫频光信号为例，第一扫频光信号与第二扫频光信号为N个扫频光信号中频率差最小的两个扫频光信号。第一扫频光信号与第二扫频光信号的最小频率差与天线的接收带宽相关。
示例性地，第一扫频光信号与第二扫频光信号的最小频率差满足如下公式(9)所示的条件。
min(|f 1-f 2|)>|fR 1|+|fR 2|+fOE     公式(9)
其中，f 1表示第一扫频光信号的扫频范围，f 2表示第二扫频光信号的扫频范围，fR 1表示第一扫频光信号的回波信号相对于第一扫频光信号的本振信号的频率频移量的最大值，fR 2表示第二扫频光信号的回波信号相对于第二扫频光信号的本振信号的频率频移量的最大值，fOE表示天线的接收带宽。
条件7，第一扫频光信号和第二扫频光信号的扫频斜率满足如下公式(10)所示的条件。
Figure PCTCN2022139889-appb-000009
或者
Figure PCTCN2022139889-appb-000010
其中，round()表示四舍五入取整运算，K 1表示所述第一时间段内所述第一扫频信号的扫频斜率的绝对值，K 2表示所述第一时间段内所述第二扫频信号的扫频斜率的绝对值，R min表示激光雷达的最小可探测距离，c表示光速。
示例性地，本申请实施例中N个扫频光信号所满足的条件，可以包括如上条件的多种组合。比如N个扫频光信号满足条件1+条件2+条件6+条件7。再比如，N个扫频光信号满足条件3+条件6+条件7。又比如，N个扫频光信号满足条件1+条件2+条件4+条件5+条件6+条件7。再比如，N个扫频光信号满足条件1+条件2+条件5+条件6+条件7，等等，此处不再一一列举。
在一些实施例中，本申请涉及的N个扫频光信号的每个周期信号可以采用三角波、梯形波、锯齿波等各种频率随时间线性变化的扫频波形，或者上述波形的任意组合。另一些实施例中，一些扫频光信号可以采用恒定频率波形，即扫频斜率为0。作为一种举例，参见图7所示的扫频波形。
合分波组件612将N个扫频光信号进行合波得到雷达发射信号，并将雷达发射信号进行分光处理得到本振信号和探测信号，将探测信号通过天线发射，将本振信号发送给激光雷达的接收装置620。
接收装置620接收来自发送装置610的本振信号和发送装置610发送的探测信号的回波信号，并将回波信号和本振信号进行混频处理生成混频信号，然后根据混频信号获得探测物体的定位信息。示例性地，定位信息包括探测物体的速度、与激光雷达的距离以及反 射率等等信息。
一些实施例中，N个扫频光信号合波时，可以采用频率复用的方式，也可以采用偏振复用的方式。需要说明的是，在采用偏振复用的方式，N个扫频光信号之间对上述条件6所描述的保护带宽没有要求。
作为一种举例，以第一扫频光信号与第二光扫频信号为例，并且第一扫频光信号和第二扫频光信号在发射之前是采用频率复用的方式合波的。结合图8示例描述两个扫频光信号的几种可能的扫频波形。图8中(1)-(3)中以第一扫频光信号的扫频带宽为B1，第二扫频光信号的扫频带宽为B2为例。第一扫频光信号与第二扫频光信号之间具有保护带宽。第一扫频光信号和第二扫频光信号存在至少两段扫频斜率符号相反的时间段。图8中(1)-(3)在第一时间段内第一扫频光信号的扫频斜率与第二扫频光信号的扫频斜率符号相反且扫频斜率的绝对值不等。在第二时间段内第一扫频光信号的扫频斜率与第二扫频光信号的扫频斜率符号相反且扫频斜率的绝对值不等。在第一时间段内第一扫频光信号的扫频斜率与第二时间段内第二扫频光信号的扫频斜率不相同，以及第一时间段内第二扫频光信号的扫频斜率与第二时间段第一扫频光信号的扫频斜率不相同。
作为一种举例，以图8中(1)所示的第一扫频光信号和第二扫频光信号为例，实现准确获得多目标的定位信息的效果进行描述。参见图9所示，以两个探测目标为例。第一扫频光信号的本振信号1分别对应的两个回波信号为回波信号1-1和回波信号1-2。第二扫频光信号的本振信号2分别对应的两个回波信号为回波信号2-1和回波信号2-2。本振信号1与回波信号1-1和回波信号1-2在时间段1拍频产生的混频信号的频谱以及本振信号2与回波信号2-1和回波信号2-2在时间段1拍频产生的混频信号的频谱，参见图9中(2)所示为采用I接收机的混频信号的频谱图，参见图9中(4)为采用IQ接收机的混频信号的频谱图。本振信号1与回波信号1-1和回波信号1-2在时间段2拍频产生的混频信号的频谱以及本振信号2与回波信号2-1和回波信号2-2在时间段2拍频产生的混频信号的频谱，参见图9中(3)所示为采用I接收机的混频信号的频谱图，参见图9中(5)为采用IQ接收机的混频信号的频谱图。
一些实施例中，在采用IQ接收机的情况下，可以基于公式(2)-公式(4)来确定探测目标的速度和探测目标的距离。
另一些实施例中，在采用I接收机或者Q接收机的情况下，可以通过如下公式(6)-(8)结合公式(3)和(4)分别计算探测目标的速度和距离。由于本申请实施例中采用多个扫频光信号来进行探测，因此针对每个扫频光信号与本振信号的混频得到的混频信号均可以通过如下公式(6)-(8)结合公式(3)和(4)计算探测目标的速度和距离。
由于不同斜率的扫频光信号的引入，真实目标在不同的扫频光信号分别对应的两个时间段内进行相干探测。由于不同的扫频光信号计算得到的真实目标的距离和速度不会发生变化，但是虚假目标的距离和速度会发生变化，因此参见图10所示，4条线的交点对应的速度和距离即为真实目标的速度和距离。本申请实施例中通过不同扫频斜率的扫频信号通过频率复用形成的发射信号，对M个探测物体进行探测，可以消除虚假目标并且不会增加探测时间。
当不同扫频光信号在频域存在一定的保护带宽时(即满足条件6的情况下)，可以防止产生不需要的拍频频率信号，从而可以防止计算出现错误，可以降低计算速度或者距离的复杂度。本申请实施例通过发射频率复用形成的发射信号，实现了多目标的区分，且没 有增加测量时间，维持激光雷达出点率不变。此外，本申请实施例支持使用I接收机或者Q接收机或者IQ接收机。而使用I接收机或者Q接收机时，通过多个扫频光信号进行频率复用形成发射信号，由于真实目标的距离和速度不会发生变化，可以针对每个扫频光信号的本振信号与回波信号进行拍频计算混频信号，然后通过上述公式(6)-(8)分别确定距离的频率分量和速度的频率分量，也就是说基于每个扫频光信号可以得到计算三个结果。以两个扫频光信号为例，则两个扫频光信号的计算结果中两个相同的结果即为最终的计算结果，可以解决现有采用I接收机或者Q接收机进行探测出现的速度模糊的问题。并且使用I接收机或者Q接收机相比使用IQ接收机可以降低成本。
作为另一种举例，以第一扫频光信号与第二光扫频信号为例，并且第一扫频光信号和第二扫频光信号在发射之前是采用偏振复用的方式合波的。结合图11示例描述两个扫频光信号的几种可能的扫频波形。图11中(1)-(3)中以第一扫频光信号的扫频带宽为B1，第二扫频光信号的扫频带宽为B2为例。第一扫频光信号和第二扫频光信号存在至少两段扫频斜率符号相反的时间段。图11中(1)-(3)在第一时间段内第一扫频光信号的扫频斜率与第二扫频光信号的扫频斜率符号相反且扫频斜率的绝对值不等。在第二时间段内第一扫频光信号的扫频斜率与第二扫频光信号的扫频斜率符号相反且扫频斜率的绝对值不等。在第一时间段内第一扫频光信号的扫频斜率与第二时间段内第二扫频光信号的扫频斜率不相同，以及第一时间段内第二扫频光信号的扫频斜率与第二时间段第一扫频光信号的扫频斜率不相同。
上述方案中，不同扫频斜率的扫频光信号通过偏振复用的方式形成发射信号，对M个探测物体进行探测，可以消除虚假目标且没有增加测量时间，维持激光雷达出点率不变。此外，支持使用I接收机或者Q接收机或者IQ接收机。而使用I接收机或者Q接收机时，通过多个扫频光信号进行频率复用形成发射信号，由于真实目标的距离和速度不会发生变化，可以针对每个扫频光信号的本振信号与回波信号进行拍频计算混频信号，然后通过上述公式(6)-(8)分别确定距离的频率分量和速度的频率分量，也就是说基于每个扫频光信号可以得到计算三个结果。以两个扫频光信号为例，则两个扫频光信号的计算结果中两个相同的结果即为最终的计算结果，可以解决现有采用I接收机或者Q接收机进行探测出现的速度模糊的问题。并且使用I接收机或者Q接收机相比使用IQ接收机可以降低成本。
在一些可能的实施方式中，为了提高探测效率，减少探测时间，扫频光信号的信号周期是激光雷达的探测周期的K倍。这里所说的扫频光信号的信号周期，可以是N个扫频光信号的信号周期中的最大信号周期。K为正整数。探测周期是指获取一次探测物体的定位信息的时间。
作为一种举例，以第一扫频光信号和第二扫频光信号为例，参见图12所示，第一扫频光信号与第二扫频光信号的扫频带宽不同。第一扫频光信号与第二扫频光信号的信号周期相同为例。图12中通过T来表示探测周期。图12中(1)中第一扫频光信号和第二扫频光信号均为三角波，信号周期等于探测周期。图12中(2)中第一扫频光信号和第二扫频光信号均为梯形波，信号周期是探测周期的2倍。图12中(3)中第一扫频光信号为三角波、第二扫频光信号为梯形波，信号周期是探测周期的2倍。图12中(4)中第一扫频光信号为三角波、第二扫频光信号为恒定频率波，信号周期等于探测周期。图12中仅用于示例性地描述信号周期与探测周期的倍数关系，具体场景中可以根据需求配置，本申请实施例中对此不作具体限定。
下面结合附图对本申请实施例中可能的发送装置610和接收装置620的结构进行介绍说明，以给出示例性地几种实现方式。
本申请实施例中接收装置620可以部署一个或者多个IQ接收机，或者部署I接收机或者Q接收机。作为一种举例，参见图13所示，为一种可能的IQ接收机的结构示意图。IQ接收机包括90度混频器6201、第一光电探测器6202和第二光电探测器6203、第一模数转换器6204和第二模数转换器6205以及信号处理器6206。示例性地，接收装置620还可以包括接收天线，接收天线也可以位于接收装置620外。需要说明的是，接收装置620中还可以包括其它的器件，本申请对此不作具体限定，能够实现IQ探测的IQ接收机的结构均适用于本申请实施例。
90度混频器6201从天线接收回波信号。接收到的回波信号中包括N个扫频光信号分别对应回波信号。当探测物体存在多个时，每个扫频光信号对应的回波信号包括多个。90度混频器6201还从发送装置610接收本振信号。接收到的本振信号中包括N个扫频光信号分别对应的本振信号。90度混频器6201对本振信号和回波信号进行混频处理，输出两路光信号，分别为I分量光信号和Q分量光信号。第一光电探测器6202对I分量光信号执行光电探测，将I分量光信号转换为第一模拟电信号。第二光电探测器6203对Q分量光信号执行光电探测，将Q分量光信号转换为第二模拟电信号。第一模数转换器6204对第一模拟电信号进行采样，将第一模拟电信号转换为第一数字信号，第二模数转换器6205对第二模拟电信号进行采样，将第二模拟信号转换为第二数字信号。进一步地，信号处理器6206对第一数字信号和第二数字信号进行处理获得探测物体的定位信息。示例性地，第一光电探测器6202和第二光电探测器6203可以采用单端光电探测器或者平衡光电探测器(balanced photo detectors，BPD)。
信号处理器6206，信号处理器6206可以包括数字信号处理器(digital signal processor、DSP)、中央处理器(CPU)、加速处理单元(APU)、图像处理单元(GPU)、微处理器或微控制器等具有计算能力的器件，该信号处理器6206用于对采样得到的数字信号进行处理，从而得到目标探测物体的速度、距离等定位信息。
本申请实施例中，对采样得到的数字信号进行处理，从而得到目标物的速度、距离等信息的操作，可以由一个或多个信号处理器6206，例如，由一个或多个DSP来完成，当然也可以由一个或多个信号处理器6206结合其他器件来完成，例如，一个DSP结合一个或多个中央处理器CPU来共同完成。信号处理器6206对采样得到的数字信号进行处理时，可以具体通过调用计算机可读存储介质存储的计算机程序来实现，该计算机可读存储介质包括但不限于是随机存储记忆体(random access memory，RAM)、只读存储器(read only memory，ROM)、可擦除可编程只读存储器(erasable programmable read only memory，EPROM)、或便携式只读存储器(compact disc read only memory，CD ROM)，其可以配置在信号处理器6206中，也可以独立于信号处理器6206。
作为另一种举例，参见图14所示，为一种可能的I接收机的结构示意图。I接收机包括180度混频器62011、光电探测器62012、模数转换器(analog digital converter，ADC)62013和信号处理器62014。180度混频器62011对本振信号和回波信号进行混频处理，输出I分量光信号。光电探测器62012对I分量光信号执行光电探测得到模拟电信号。模数转换器62013将模拟电信号转换为数字信号。进一步地，信号处理器62014对数字信号进行处理获得探测物体的定位信息。示例性地，接收装置620还可以包括接收天线，接收天 线也可以位于接收装置620外。需要说明的是，接收装置620中还可以包括其它的器件，本申请对此不作具体限定，能够实现I探测的I接收机的结构均适用于本申请实施例。
参见图15A所示为一种可能的探测系统结构示意图。图15A以通过频率复用的方式产生发射信号为例进行描述。扫频信号源611中包括N个直调的扫频激光器，图15A中以N为2为例，分别为扫频激光器61111和扫频激光器61112。合分波组件612包括至少一个定向波导耦合器6121。接收装置620可以采用IQ接收机，也可以采用I接收机或者Q接收机。图15A以采用一个IQ接收机为例，IQ接收机结构以采用图13所示的结构为例。为了描述简便，IQ接收机中各个器件不再进行标识。
扫频激光器6111，其波长随时间变化，使得输出的扫频光信号的频率在设定频率范围内变化。N个扫频激光器6111中，不同的扫频激光器6111的波长变化范围不同。
扫频激光器61111输出扫频光信号1，扫频光信号1的扫频周期为T1，扫频带宽为B1。扫频激光器61111的波长变化范围为[λ1，λ2]，输出的扫频光信号1的频率变化范围为[f1，f2]。扫频激光器61112的波长变化范围为[λ3，λ4],输出的扫频光信号2的频率变化范围为[f3，f4]。扫频带宽B1和B2可以相同也可以不同，扫频周期T1和T2可以相同也可以不同，但T1/T2或者T2/T1是正整数。图15A所示的实施例中，通过调节扫频激光器61111和扫频激光器61112发射的激光信号的波长，使得输出的扫频光信号1和扫频光信号2满足如前所述的第一扫频光信号和第二扫频光信号所满足的条件。例如，扫频光信号1和扫频光信号2满足条件1+条件2+条件4+条件5+条件6+条件7。
扫频激光器61111和扫频激光器61112输出的扫频光信号1和扫频光信号2经由定向波导耦合器6121进行耦合，并输出两路光信号，其中一路光信号作为本振信号，另外一路光信号作为探测信号。两路光信号的功率可以相同也可以不相同。一些实施例中，当两路光信号的功率不相等时，可以将功率比较小的一路光信号作为本振信号，用于对接收到的信号进行相干接收。功率比较大的一路光信号作为探测信号经由扫描器发射出去，用于对待探测物体进行探测。探测信号遇到M个待探测物体后，反射形成M个回波信号。M个回波信号到达激光雷达后，经由扫描器进行接收。M个回波信号与一路本振信号进入90度混频器6201进行光学混频得到混频信号。混频后输出的两路光信号分别由第一光电探测器6202和第二光电探测器6203转换为两路模拟电信号，再分别经由第一模数转换器6204和第二模数转换器6205转变为两路数字电信号；两路数字信号进入信号处理器6206进行处理，最终输出M个探测物体的距离、速度等信息。一些实施例中，探测信号发射之前，可以先经过放大处理，然后再发射出去。例如，发送装置610中还可以包括光放大器(图中未示出)，比如半导体光放大器、光纤放大器等等。光放大器对定向波导耦合器3输出的探测信号进行放大处理，然后再通过扫描器发射出去。
上述方案中，通过调节不同扫频激光器的波长范围来实现不同频率范围的扫频光信号，实现简单。由于不同斜率的扫频光信号的引入，真实目标在不同的扫频光信号的两个时间段内进行相干探测，可以消除假目标。当不同扫频光信号在频域存在一定的保护带宽时(即满足条件6的情况下)，可以防止产生不需要的拍频频率信号，从而可以防止计算出现错误，可以降低计算速度或者距离的复杂度。本申请实施例通过发射频率复用形成的发射信号，实现了多目标的区分，且没有增加测量时间，维持激光雷达出点率不变。此外，上述方案中，由于扫频光信号1的频率值恒小于扫频光信号2的频率值。从而扫频光信号1和扫频光信号2在90度混频器6201中不会发生混淆，因此可以使用同一个接收机进行接收。 进而可以提高资源利用率，并且降低成本。
示例性地，参见图15B所示，以扫描频光信号1和扫频光信号2的波形如下图15B中的(1)所示。则在速率正常情况的信号波形和频谱参见图15B中(2)所示。则在速率过快情况的信号波形和频谱参见图15B中(3)所示。图15B中，扫频光信号1的本振信号称为本振信号1，扫频光信号1的回波信号称为回波信号1，扫频光信号2的本振信号称为本振信号2，扫频光信号2的回波信号称为回波信号2。需要说明的是，图15B仅以扫频光信号1和扫频光信号2的部分波形来进行说明的，其它部分的原理类似不再重复说明。从图15B中(2)和图15B中(3)可以看出，由于扫频光信号1的频率值恒小于扫频光信号2的频率值。从而扫频光信号1和扫频光信号2在90度混频器6201中不会发生混淆。
参见图16所示为一种可能的探测系统结构示意图。图16以通过频率复用的方式产生发射信号为例进行描述。扫频信号源611中包括N个直调的扫频激光器，图16中以N为2为例，分别为扫频激光器61111和扫频激光器61112。合分波组件612包括三个定向波导耦合器6121，为了便于区分，分别称为定向波导耦合器6121-1、定向波导耦合器6121-2和定向波导耦合器6121-3。接收装置620可以采用2个IQ接收机。为了描述简便，IQ接收机中各个器件不再进行标识。
扫频激光器61111输出扫频光信号1。扫频激光器61112输出扫频光信号2。扫频光信号1和扫频光信号2满足的条件参见图15A对应的实施例的描述，此处不再赘述。扫频光信号1经过定向波导耦合器6121-1输出分为两部分，其中一部分光信号作为本振信号传向其中一个接收机，另一部光信号进入定向波导耦合器6121-3。扫频光信号2经过定向波导耦合器6121-2输出分为两部分，其中一部分光信号作为本振信号传向另一个接收机，另一部光信号进入定向波导耦合器6121-3。定向波导耦合器3输出的探测信号经由扫描器发射出去对待测物体进行探测。一些实施例中，探测信号发射之前，可以先经过放大处理，然后再发射出去。例如，发送装置610中还可以包括光放大器(图中未示出)，光放大器对定向波导耦合器3输出的探测信号进行放大处理，然后再通过扫描器发射出去。一些实施例中，探测系统中还可以包括波分解复用器，用于对从扫描器接收的回波信号进行分光处理为两路光信号分别进入到两个接收机。两个接收机的处理方式如前所述，此处不再赘述。
通过使用两个不同波长范围、不同扫频斜率的扫频光信号频率复用形成的发射信号，对M个探测物体进行探测，可以消除假目标。此外，通过在收端使用不同IQ接收机对不同扫频光信号进行相干探测，减少信号处理器的计算复杂度。上述实施例在实现多目标探测物体的准确定位且没有增加测量时间，维持激光雷达出点率不变。
一些实施例中，图16所示的探测系统中，接收装置620也可以采用2个I接收机或者Q接收机，并不会出现速度模糊的问题，并且可以降低探测成本。
参见图17所示为一种可能的探测系统结构示意图。图17与图16对应的实施例不同的是：图17中，合分波组件包括波分复用器61211和耦合器61212。N个扫频激光器输出的扫频光信号1-N，经由波分复用器61211进行复用，波分复用器61211输出的光信号由耦合器分为两路光，其中一路光信号作为本振信号输入到接收机，另一路光信号作为探测信号通过扫描器发出。一些实施例中，探测信号发射之前，可以先经过放大处理，然后再发射出去。例如，发送装置610中还可以包括光放大器(图中未示出)，光放大器对耦合器61212输出的探测信号进行放大处理，然后再通过扫描器发射出去。
上述方案中，通过将N个不同扫频波形的信号加载到不同的波长范围的激光信号上并 进行频率复用生成发射信号，使用该信号同时对M个探测物体进行探测，可以消除假目标。此外，通过在接收端使用IQ接收机对不同扫频光信号进行相干探测，减少信号处理器的计算复杂度。上述实施例在实现多目标探测物体的准确定位且没有增加测量时间，维持激光雷达出点率不变。一些实施例中，图17所示的探测系统中，接收装置620也可以采用I接收机或者Q接收机，并不会出现速度模糊的问题，并且可以降低探测成本。
参见图18所示为一种可能的探测系统结构示意图。图18与图15A对应的实施例不同的是：图15A中接收装置620中采用一个IQ接收机，图18中接收装置620采用一个I接收机或者Q接收机。采用上述方案，不会出现速度模糊的问题，并且可以降低探测成本。
参见图19所示为一种可能的探测系统结构示意图。图19中N个扫频光信号通过对激光器发射的激光信号进行IQ调制的方式来产生，扫频波形可以由数字信号处理的方式生成。扫频信号源611中包括激光器1910、调制器1920、扫频驱动信号源1930和两个射频放大器。为了便于区分，将两个射频放大器分别称为射频放大器1941和射频放大器1942。参见图20所示为扫频驱动信号源产生N个扫频信号的方式。扫频信号1-扫频信号N为N个频率不同的扫频信号，分别经过不同的上变频处理得到频率范围满足如前所述条件的扫频信号。然后通过取实部和虚部以及数模转换处理，将扫频数字信号转换为扫频模拟信号。进一步经过射频放大后，调制到激光器发射的激光信号上。不同的扫频频率范围的扫频模拟信号调制到激光信号上后，得到扫频频率范围不同的扫频光信号。合分波组件612中包括耦合器1950。用于将调制器1920发出的包括N个扫频光信号的一路光信号进行分光得到本振信号和探测信号。耦合器1950将本振信号发送给接收装置620，将探测信号通过扫描器发射出去。一些实施例中，探测信号发射之前，可以先经过放大处理，然后再发射出去。例如，发送装置610中还可以包括光放大器(图中未示出)，光放大器对耦合器1950输出的探测信号进行放大处理，然后再通过扫描器发射出去。
该方案中，通过将不同扫频斜率且扫频方向相反的扫频模拟电信号加载到激光信号上，得到扫频频率范围满足要求的N个扫频光信号，对M个探测物体进行探测，可以消除假目标的问题。本申请实施例可以实现多目标探测物体的定位且没有增加测量时间，维持激光雷达出点率不变。一些实施例中，图19所示的探测系统中，接收装置620也可以采用I接收机或者Q接收机，并不会出现速度模糊的问题，并且可以降低探测成本。
参见图21所示为一种可能的探测系统结构示意图。图21中N个扫频光信号通过对激光器发射的激光信号进行IQ调制的方式来产生，扫频波形可以由数字信号处理的方式生成。图21中，扫频信号源611中包括N个扫频信号发射组件，分别为扫频信号发射组件1～N。每个扫频信号发射组件包括扫频驱动信号源2101、射频放大器2102和射频放大器2103、激光器2104以及调制器2105。扫频驱动信号源2101产生一个频率周期变化的扫频信号，并经过射频放大器放大后输入调制器。激光器2104发射激光信号。调制器2105将经过放大的扫频信号调制到激光信号上得到一个扫频光信号。从而N个扫频信号发射组件产生N个扫频光信号。合分波组件612中包括耦合器2106。用于将N个扫频信号发射组件发射的扫频光信号进行合束处理，然后分光得到本振信号和探测信号。耦合器2106将本振信号发送给接收装置620，将探测信号通过扫描器发射出去。一些实施例中，探测信号发射之前，可以先经过放大处理，然后再发射出去。例如，发送装置610中还可以包括光放大器(图中未示出)，光放大器对耦合器2106输出的探测信号进行放大处理，然后再通过扫描器发射出去。
示例性地，扫频驱动信号源2101产生频率周期变化的扫频信号的方式可以参见图22所示。对数字扫频信号进行取实部和虚部处理，然后通过数模转换处理转换为模拟扫频信号。
一种示例中，不同扫频信号发射组件包括的激光器发射的激光信号的波长不同。该示例中通过激光器发射不同波长的激光信号，来使得N个扫频信号发射组件发出的扫频光信号的频率范围满足如前所示的条件。
另一种示例中，不同扫频信号发射组件包括的扫频驱动信号源产生的扫频信号的频率范围不同。该示例中通过扫频信号源产生不同频率范围的扫频模拟电信号，并调制到激光器发射的激光信号上，来使得N个扫频信号发射组件发出的扫频光信号的频率范围满足如前所示的条件。
又一种示例中，不同扫频信号发射组件包括的激光器发射的激光信号的波长不同以及不同扫频信号发射组件包括的扫频驱动信号源产生的扫频信号的频率范围不同。该示例中通过扫频信号源产生不同频率范围的扫频模拟电信号，并对应调制到N个激光器分别发射的不同波长的激光信号上，来使得N个扫频信号发射组件发出的扫频光信号的频率范围满足如前所示的条件。
上述方案通过数字信号处理的方式产生N个满足条件的扫频信号，并调制到激光信号上而产生N个满足条件的扫频光信号，以对M个探测物体进行探测，可以消除虚假目标。相邻两个扫频模拟电信号在频域存在一定的保护带宽，从而使得输出的相邻两个扫频光信号间在频域存在一定的保护带宽，以防止产生不需要的拍频频率信号。本申请实施例可以实现多目标探测物体的定位且没有增加测量时间，维持激光雷达出点率不变。
一些实施例中，图21所示的探测系统中，接收装置620也可以采用I接收机或者Q接收机，并不会出现速度模糊的问题，并且可以降低探测成本。
参见图23所示为一种可能的探测系统结构示意图。图23中N个扫频光信号通过对激光器发射的激光信号进行调制的方式来产生，扫频波形可以由数字信号处理的方式生成。图23中，扫频信号源611中包括激光器2301、光频梳2302、N个微环调制器以及N个扫频驱动信号源。N个微环调制器分别为微环调制器1～N，N个扫频驱动信号源分别为扫频驱动信号源1～N。扫频驱动信号源产生扫频信号的原理可以参见图22所示，此处不再赘述。
激光器2301发射激光信号。光频梳2302将激光信号进行处理得到N个波长的光信号。N个扫频驱动信号源与N个微环调制器一一对应连接，N个微环调制器在N个波长的光信号的光路依次串联排布。微环调制器i(i＝1……N)将扫频驱动信号源i输出的频率范围周期变化的扫频信号调制到微环调制器i对应波长的光信号上，从而得到N个满足如前所述条件的扫频光信号。N个微环调制器与N个波长一一对应，不同扫频驱动信号源输出的扫频信号的频率范围不同。合分波组件612中可以包括定向波导耦合器2303，用于将微环调制器N输出的光信号进行分光得到本振信号和探测信号。定向波导耦合器2303将本振信号发送给接收装置620，将探测信号通过扫描器发射出去。一些实施例中，探测信号发射之前，可以先经过放大处理，然后再发射出去。例如，发送装置610中还可以包括光纤放大器(图中未示出)，光纤放大器对定向波导耦合器2303输出的探测信号进行放大处理，然后再通过扫描器发射出去。
该方案中，通过N个扫频驱动信号源产生不同频率范围的扫频模拟电信号，通过光频 梳将激光信号转换为多个频率的光，也可以理解为不同的波长的光。并通过N个微环调制器分别将N个不同频率范围的扫频模拟电信号调制到不同波长的光信号上，产生的N个扫频光信号的频率范围满足如前所示的条件。通过发射N个满足条件的扫频光信号，对M个探测物体进行探测，可以消除虚假目标。相邻两个扫频模拟电信号在频域存在一定的保护带宽，使得相邻两个扫频光信号在频域存在一定的保护带宽，以防止产生不需要的拍频频率信号。本申请实施例可以实现多目标探测物体的定位且没有增加测量时间，维持激光雷达出点率不变。
一些实施例中，图23所示的探测系统中，接收装置620也可以采用I接收机或者Q接收机，并不会出现速度模糊的问题，并且可以降低探测成本。
参见图24所示为一种可能的探测系统结构示意图。扫频信号源611中包括N个扫频激光器，分别为扫频激光器1～N。不同的扫频激光器产生的扫频光信号的偏振方向不同。N个扫频激光器产生N个扫频光信号，该N个光信号满足如前所述的条件。图24中，合分波组件612包括偏振合束器(polarization beam combiner，PBC)2401和保偏耦合器2402。偏振合束器2401基于N个扫频光信号的偏振方向对N个扫频光信号进行合束得到雷达发射信号。然后保偏耦合器2402将雷达发射信号进行分光得到本振信号和探测信号。保偏耦合器2402将本振信号发送给接收装置620，将探测信号通过扫描器发射出去。一些实施例中，探测信号发射之前，可以先经过放大处理，然后再发射出去。例如，发送装置610中还可以包括保偏放大器(图中未示出)，保偏放大器对保偏耦合器2402输出的探测信号进行放大处理，然后再通过扫描器发射出去。
上述方案中，不同扫频斜率的扫频光信号通过偏振复用方式形成发射信号，对M个探测物体进行探测，可以消除虚假目标且没有增加测量时间，维持激光雷达出点率不变。一些实施例中，图24所示的探测系统中，接收装置620也可以采用I接收机或者Q接收机，并不会出现速度模糊的问题，并且可以降低探测成本。
基于上述内容和相同的构思，本申请提供一种激光雷达的探测方法，请参阅图25的介绍。该探测方法可应用于上述图15A至图24任一实施例所示的探测系统。也可以理解为，可以基于上述图15A至图24任一实施例所示的探测系统来实现探测方法。
如图25所示，为本申请提供的一种激光雷达的探测方法的流程示意图。该探测方法包括以下步骤：
2501，发射N个扫频光信号，N为大于1的整数，在第一时间段内所述N个扫频光信号中第一扫频光信号的扫频斜率与第二扫频光信号的扫频斜率的符号相反，或者所述第一扫频光信号的扫频斜率为0且所述第二扫频光信号的扫频斜率不为0；所述N个扫频光信号的频率不同。
关于N个扫频光信号所需满足的条件可以参见前述相关描述，此处不再赘述。
2502，将所述N个扫频光信号进行合波得到的雷达发射信号，并将所述雷达发射信号分为本振信号和探测信号。
2503，将所述探测信号通过天线发射。所述本振信号用于与所述探测信号的回波信号进行相干探测获取探测物体的定位信息。
一种可能的设计中，探测方法还可以包括：
2504，从所述天线接收所述探测信号的回波信号，并将所述回波信号和所述本振信号进行混频处理生成混频信号；
2505，根据所述混频信号获得探测物体的定位信息。
在一种可能的实现方式中，所述第一扫频光信号和所述第二扫频光信号为周期性的扫频光信号。
在一种可能的实现方式中，所述第一扫频光信号的信号周期是所述第二扫频光信号的信号周期的M倍，或者所述第二扫频信号的信号周期是所述第一扫频光信号的信号周期的M倍，M为正整数。
在一种可能的实现方式中，所述第一扫频光信号的信号周期为所述激光雷达的探测周期的K倍，或者所述第二扫频光信号的信号周期为所述激光雷达的探测周期的K倍，K为正整数。
在一种可能的实现方式中，所述第一扫频光信号的信号周期大于或者等于所述第二扫频信号的信号周期；在第一扫频光信号的一个信号周期中，所述第一扫频信号在第一时间段内的扫频斜率与第二时间段内的扫频斜率的符号相反；所述第二扫频信号在第一时间段的扫频斜率与第二时间段内的扫频斜率的符号相反；所述第一时间段内所述第一扫频信号的扫频斜率与所述第二时间段内所述第二扫频信号的扫频斜率不相同，以及所述第一时间段内所述第二扫频信号的扫频斜率与所述第二时间段内所述第一扫频信号的扫频斜率不相同。
在一种可能的实现方式中，所述第一扫频光信号与所述第二扫频光信号的最小频率差与所述天线的接收带宽相关。
在一种可能的实现方式中，所述第一扫频光信号与所述第二扫频光信号的最小频率差满足如下条件：
min(|f 1-f 2|)>|fR 1|+|fR 2|+fOE；
其中，f 1表示所述第一扫频光信号的扫频范围，f 2表示所述第二扫频光信号的扫频范围，fR 1表示所述第一扫频光信号的回波信号相对于所述第一扫频光信号的本振信号的频率频移量的最大值，fR 2表示所述第二扫频光信号的回波信号相对于所述第二扫频光信号的本振信号的频率频移量的最大值，fOE表示所述天线的接收带宽。
在一种可能的实现方式中，所述第一扫频信号和所述第二扫频信号满足：
Figure PCTCN2022139889-appb-000011
或者
Figure PCTCN2022139889-appb-000012
其中，round()表示四舍五入取整运算，K 1表示所述第一时间段内所述第一扫频信号的扫频斜率的绝对值，K 2表示所述第一时间段内所述第二扫频信号的扫频斜率的绝对值，R min表示激光雷达的最小可探测距离，c表示光速。
在一种可能的实现方式中，所述第一扫频光信号的波形包括三角波、梯形波、锯齿波中的至少一种；所述第二扫频光信号的扫频斜率不为0时，所述第二扫频光信号的波形包括三角波、梯形波、锯齿波中的至少一种。
在一种可能的实现方式中，所述N个扫频光信号的波长变化范围不同，或者所述N个扫频光信号的偏振方向不同。
在本申请的各个实施例中，如果没有特殊说明以及逻辑冲突，不同的实施例之间的术语和/或描述具有一致性、且可以相互引用，不同的实施例中的技术特征根据其内在的逻辑关系可以组合形成新的实施例。
本领域的技术人员可以清楚地了解到，为了描述的方便和简洁，上述描述的方法，可以参考前述装置或者系统实施例中的对应的描述，在此不再赘述。
尽管结合具体特征及其实施例对本申请进行了描述，显而易见的，在不脱离本申请的范围的情况下，可对其进行各种修改和组合。相应地，本说明书和附图仅仅是所附权利要求所界定的方案进行示例性说明，且视为已覆盖本申请范围内的任意和所有修改、变化、组合或等同物。
显然，本领域的技术人员可以对本申请进行各种改动和变型而不脱离本申请的范围。这样，倘若本申请实施例的这些修改和变型属于本申请权利要求及其等同技术的范围之内，则本申请也意图包含这些改动和变型在内。

Claims (25)

  1. 一种激光雷达的发送装置，其特征在于，包括扫频信号源、合分波组件；其中，
    所述扫频信号源，用于发射N个扫频光信号，N为大于1的整数，在第一时间段内所述N个扫频光信号中第一扫频光信号的扫频斜率与第二扫频光信号的扫频斜率的符号相反，或者所述第一扫频光信号的扫频斜率不为0且所述第二扫频光信号的扫频斜率为0；所述N个扫频光信号的频率不同；
    所述合分波组件，用于将所述N个扫频光信号进行合波得到雷达发射信号，并将所述雷达发射信号进行分光处理得到本振信号和探测信号，将所述探测信号通过天线发射，将所述本振信号发送给所述激光雷达的接收装置。
  2. 如权利要求1所述的发送装置，其特征在于，所述第一扫频光信号的扫频斜率的绝对值与第二扫频光信号的扫频斜率的绝对值不同。
  3. 如权利要求1或2所述的发送装置，其特征在于，所述第一扫频光信号和所述第二扫频光信号为周期性的扫频光信号。
  4. 如权利要求3所述的发送装置，其特征在于，所述第一扫频光信号的信号周期是所述第二扫频光信号的信号周期的M倍，或者，所述第二扫频信号的信号周期是所述第一扫频光信号的信号周期的M倍，M为正整数。
  5. 如权利要求3或4所述的发送装置，其特征在于，所述第一扫频光信号的信号周期为所述激光雷达的探测周期的K倍，或者所述第二扫频光信号的信号周期为所述激光雷达的探测周期的K倍，K为正整数。
  6. 如权利要求3-5任一项所述的发送装置，其特征在于：
    一个目标信号周期中，所述第一扫频光信号在所述第一时间段内的扫频斜率与第二时间段内的扫频斜率的符号相反；所述第二扫频光信号在所述第一时间段的扫频斜率与所述第二时间段内的扫频斜率的符号相反；
    所述第一时间段内所述第一扫频光信号的扫频斜率与所述第二时间段内所述第二扫频光信号的扫频斜率不相同，以及所述第一时间段内所述第二扫频光信号的扫频斜率与所述第二时间段内所述第一扫频光信号的扫频斜率不相同；
    其中，所述目标信号周期为所述第一扫频光信号的信号周期和所述第二扫频光信号的信号周期中的最大信号周期。
  7. 如权利要求1-6任一项所述的发送装置，其特征在于，所述第一扫频光信号与所述第二扫频光信号的最小频率差与所述天线的接收带宽相关。
  8. 如权利要求7所述的发送装置，其特征在于，所述第一扫频光信号与所述第二扫频光信号的最小频率差满足如下条件：
    min(|f 1-f 2|)>|fR 1|+|fR 2|+fOE；
    其中，f 1表示所述第一扫频光信号的扫频范围，f 2表示所述第二扫频光信号的扫频范围，fR 1表示所述第一扫频光信号的回波信号相对于所述第一扫频光信号的本振信号的频率频移量的最大值，fR 2表示所述第二扫频光信号的回波信号相对于所述第二扫频光信号的本振信号的频率频移量的最大值，fOE表示所述天线的接收带宽。
  9. 如权利要求1-8任一项所述的发送装置，其特征在于，所述第一扫频信号和所述第二扫频信号满足：
    Figure PCTCN2022139889-appb-100001
    或者
    Figure PCTCN2022139889-appb-100002
    其中，round()表示四舍五入取整运算，K 1表示所述第一时间段内所述第一扫频信号的扫频斜率的绝对值，K 2表示所述第一时间段内所述第二扫频信号的扫频斜率的绝对值，R min表示激光雷达的最小可探测距离，c表示光速。
  10. 如权利要求1-9任一项所述的发送装置，其特征在于，所述第一扫频光信号的波形包括三角波、梯形波、锯齿波中的至少一种；
    所述第二扫频光信号的扫频斜率不为0时，所述第二扫频光信号的波形包括三角波、梯形波、锯齿波中的至少一种。
  11. 如权利要求1-10任一项所述的发送装置，其特征在于，所述N个扫频光信号的波长变化范围不同，或者所述N个扫频光信号的偏振方向不同。
  12. 一种激光雷达的探测系统，其特征在于，包括如权利要求1-11任一项所述的激光雷达的发送装置和激光雷达的接收装置；
    所述接收装置，用于接收来自所述发送装置的本振信号和所述发送装置发送的探测信号的回波信号，并将所述回波信号和所述本振信号进行混频处理生成混频信号；根据所述混频信号获得探测物体的定位信息。
  13. 如权利要求12所述的系统，其特征在于，所述接收装置包括90度混频器、第一光电探测器、第二光电探测器、第一模数转换器、第二模数转换器和信号处理器；
    所述90度混频器，用于对从天线接收的所述探测信号的回波信号和所述本振信号进行混频处理生成混频信号，将混频信号分为第一路信号和第二路信号，并将所述第一路信号发送给所述第一光电探测器，以及将所述第二路信号发送给所述第二光电探测器；
    所述第一光电探测器，用于对所述第一路信号进行探测处理后，输出给所述第一模数转换器进行模数转换；
    所述第二光电探测器，用于对所述第二路信号进行探测处理后，输出给所述第二模数转换器进行模数转换；
    所述信号处理器，用于对所述第一模数转换器输出的数字信号和所述第二模数转换器输出的数字信号进行处理，获得探测物体的定位信息。
  14. 如权利要求12所述的系统，其特征在于，所述接收装置包括180度混频器、第三光电探测器、第三模数转换器和信号处理器；
    所述180度混频器，用于对从天线接收的所述探测信号的回波信号和所述本振信号进行混频处理生成混频信号，将混频信号发送给所述第三光电探测器；
    所述第三光电探测器，用于对所述混频信号进行探测处理后，输出给所述第三模数转换器进行模数转换；
    所述信号处理器，用于对所述第三模数转换器输出的数字信号进行处理，获得探测物体的定位信息。
  15. 一种基于激光雷达的探测方法，其特征在于，包括：
    发射N个扫频光信号，N为大于1的整数，在第一时间段内所述N个扫频光信号中第一扫频光信号的扫频斜率与第二扫频光信号的扫频斜率的符号相反，或者所述第一扫频光信号的扫频斜率为0且所述第二扫频光信号的扫频斜率不为0；所述N个扫频光信号的频率不同；
    将所述N个扫频光信号进行合波得到的雷达发射信号，并将所述雷达发射信号分为本振信号和探测信号，将所述探测信号通过天线发射；
    从所述天线接收所述探测信号的回波信号，并将所述回波信号和所述本振信号进行混频处理生成混频信号；
    根据所述混频信号获得探测物体的定位信息。
  16. 如权利要求15所述的方法，其特征在于，所述第一扫频光信号的扫频斜率的绝对值与第二扫频光信号的扫频斜率的绝对值不同。
  17. 如权利要求15或16所述的方法，其特征在于，所述第一扫频光信号和所述第二扫频光信号为周期性的扫频光信号。
  18. 如权利要求17所述的方法，其特征在于，所述第一扫频光信号的信号周期是所述第二扫频光信号的信号周期的M倍，或者所述第二扫频信号的信号周期是所述第一扫频光信号的信号周期的M倍，M为正整数。
  19. 如权利要求17或18所述的方法，其特征在于，所述第一扫频光信号的信号周期为所述激光雷达的探测周期的K倍，或者所述第二扫频光信号的信号周期为所述激光雷达的探测周期的K倍，K为正整数。
  20. 如权利要求17-19任一项所述的方法，其特征在于：
    在一个目标信号周期中，所述第一扫频光信号在所述第一时间段内的扫频斜率与第二时间段内的扫频斜率的符号相反；所述第二扫频光信号在所述第一时间段的扫频斜率与所述第二时间段内的扫频斜率的符号相反；
    所述第一时间段内所述第一扫频光信号的扫频斜率与所述第二时间段内所述第二扫频光信号的扫频斜率不相同，以及所述第一时间段内所述第二扫频光信号的扫频斜率与所述第二时间段内所述第一扫频光信号的扫频斜率不相同；
    其中，所述目标信号周期为所述第一扫频光信号的信号周期和所述第二扫频光信号的信号周期中的最大信号周期。
  21. 如权利要求15-20任一项所述的方法，其特征在于，所述第一扫频光信号与所述第二扫频光信号的最小频率差与所述天线的接收带宽相关。
  22. 如权利要求21所述的方法，其特征在于，所述第一扫频光信号与所述第二扫频光信号的最小频率差满足如下条件：
    min(|f 1-f 2|)>|fR 1|+|fR 2|+fOE；
    其中，f 1表示所述第一扫频光信号的扫频范围，f 2表示所述第二扫频光信号的扫频范围，fR 1表示所述第一扫频光信号的回波信号相对于所述第一扫频光信号的本振信号的频率频移量的最大值，fR 2表示所述第二扫频光信号的回波信号相对于所述第二扫频光信号的本振信号的频率频移量的最大值，fOE表示所述天线的接收带宽。
  23. 如权利要求15-22任一项所述的方法，其特征在于，所述第一扫频信号和所述第二扫频信号满足：
    Figure PCTCN2022139889-appb-100003
    或者
    Figure PCTCN2022139889-appb-100004
    其中，round()表示四舍五入取整运算，K 1表示所述第一时间段内所述第一扫频信号的扫频斜率的绝对值，K 2表示所述第一时间段内所述第二扫频信号的扫频斜率的绝对值， R min表示激光雷达的最小可探测距离，c表示光速。
  24. 如权利要求15-23任一项所述的方法，其特征在于，所述第一扫频光信号的波形包括三角波、梯形波、锯齿波中的至少一种；
    所述第二扫频光信号的扫频斜率不为0时，所述第二扫频光信号的波形包括三角波、梯形波、锯齿波中的至少一种。
  25. 如权利要求15-24任一项所述的方法，其特征在于，所述N个扫频光信号的波长变化范围不同，或者所述N个扫频光信号的偏振方向不同。
PCT/CN2022/139889 2021-12-29 2022-12-19 一种激光雷达的发送装置、探测系统以及探测方法 WO2023125093A1 (zh)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202280043771.1A CN117561457A (zh) 2021-12-29 2022-12-19 一种激光雷达的发送装置、探测系统以及探测方法

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202111637896.0A CN116413676A (zh) 2021-12-29 2021-12-29 一种激光雷达的发送装置、探测系统以及探测方法
CN202111637896.0 2021-12-29

Publications (1)

Publication Number Publication Date
WO2023125093A1 true WO2023125093A1 (zh) 2023-07-06

Family

ID=86997687

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2022/139889 WO2023125093A1 (zh) 2021-12-29 2022-12-19 一种激光雷达的发送装置、探测系统以及探测方法

Country Status (2)

Country Link
CN (3) CN116413676A (zh)
WO (1) WO2023125093A1 (zh)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116931002B (zh) * 2023-09-07 2023-12-29 深圳市速腾聚创科技有限公司 激光雷达及可移动设备
CN117008145B (zh) * 2023-09-12 2023-12-29 深圳市速腾聚创科技有限公司 激光雷达及可移动设备

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2545678A (en) * 2015-12-21 2017-06-28 Canon Kk Method and apparatus for transmitting a continuous radar wave
CN108008391A (zh) * 2017-11-28 2018-05-08 中南大学 一种基于fmcw的车载雷达多目标识别方法
US20190361113A1 (en) * 2018-05-24 2019-11-28 The Boeing Company Combined Radar and Communications System Using Common Signal Waveform
CN112639523A (zh) * 2020-06-30 2021-04-09 华为技术有限公司 一种雷达探测方法及相关装置
CN112859061A (zh) * 2021-03-12 2021-05-28 兰州理工大学 一种基于调频连续波雷达的多目标检测方法
CN113820688A (zh) * 2021-11-25 2021-12-21 之江实验室 一种基于双光频梳的三维固态激光雷达探测方法及装置

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2545678A (en) * 2015-12-21 2017-06-28 Canon Kk Method and apparatus for transmitting a continuous radar wave
CN108008391A (zh) * 2017-11-28 2018-05-08 中南大学 一种基于fmcw的车载雷达多目标识别方法
US20190361113A1 (en) * 2018-05-24 2019-11-28 The Boeing Company Combined Radar and Communications System Using Common Signal Waveform
CN112639523A (zh) * 2020-06-30 2021-04-09 华为技术有限公司 一种雷达探测方法及相关装置
CN112859061A (zh) * 2021-03-12 2021-05-28 兰州理工大学 一种基于调频连续波雷达的多目标检测方法
CN113820688A (zh) * 2021-11-25 2021-12-21 之江实验室 一种基于双光频梳的三维固态激光雷达探测方法及装置

Also Published As

Publication number Publication date
CN117561457A (zh) 2024-02-13
CN117872313A (zh) 2024-04-12
CN116413676A (zh) 2023-07-11

Similar Documents

Publication Publication Date Title
WO2023125093A1 (zh) 一种激光雷达的发送装置、探测系统以及探测方法
CN106707291B (zh) 一种双频线性调频相干测风激光雷达
EP3637134B1 (en) Laser radar device
CA2800267C (en) Method and apparatus for a pulsed coherent laser range finder
EP3546982B1 (en) Laser radar device
CN111665486B (zh) 激光雷达系统
JP2013238474A (ja) レーザーレーダー装置
EP3605140B1 (en) Laser radar device
CN205608187U (zh) 一种多波长光束合成的相干多普勒激光测风雷达
CN116736319B (zh) 激光雷达及测速测距的方法
US20190032635A1 (en) Laser radar device and wind turbine control system
CN111175780A (zh) 一种注入锁定调频连续波激光雷达测速装置及方法
Xu et al. FMCW lidar using phase-diversity coherent detection to avoid signal aliasing
JP4932378B2 (ja) コヒーレントライダ装置
JP2007085758A (ja) ライダー装置
JP4053542B2 (ja) レーザーレーダ装置
JP2010127839A (ja) レーザレーダ装置
JP3307153B2 (ja) レーザレーダ装置
EP3754364A1 (en) Laser radar device
CN116106917A (zh) 一种并行线性调频连续波激光雷达测距测速系统
CN116660917A (zh) 激光雷达
GB2586499A (en) Multi-pixel coherent LIDAR imaging
WO2020113356A1 (zh) 风场信息测量方法及机舱式激光雷达
CN115236697A (zh) 分时多频脉冲测风激光雷达系统和风速测量方法
JP2006023245A (ja) 微小振動検出装置

Legal Events

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

Ref document number: 22914347

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 202280043771.1

Country of ref document: CN