CN111337902A - Multi-channel high-repetition-frequency large-dynamic-range distance and speed measuring laser radar method and device - Google Patents
Multi-channel high-repetition-frequency large-dynamic-range distance and speed measuring laser radar method and device Download PDFInfo
- Publication number
- CN111337902A CN111337902A CN202010354911.XA CN202010354911A CN111337902A CN 111337902 A CN111337902 A CN 111337902A CN 202010354911 A CN202010354911 A CN 202010354911A CN 111337902 A CN111337902 A CN 111337902A
- Authority
- CN
- China
- Prior art keywords
- frequency
- signal
- target
- phase
- output
- Prior art date
- Legal status (The legal status 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 status listed.)
- Granted
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
- G01S7/481—Constructional features, e.g. arrangements of optical elements
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
- G01S17/02—Systems using the reflection of electromagnetic waves other than radio waves
- G01S17/50—Systems of measurement based on relative movement of target
- G01S17/58—Velocity or trajectory determination systems; Sense-of-movement determination systems
Abstract
The invention discloses a multi-channel high-repetition-frequency large-dynamic-range distance and speed measuring laser radar method and a device, wherein a laser light source generates a light beam which is divided into output light beams of N channels through a beam splitter, the output light beam of each channel is subjected to broadband linear frequency modulation, and then the phase modulator is driven after phase shifting with different amplitudes, so that the output light beam of each channel has different time delay; then the local oscillation light beam and the emission light beam are divided by a beam splitter; the N emission beams are parallelly emitted to a target and receive echo beams of the target, then coherent light mixing is carried out on the emission beams and corresponding local oscillator beams to obtain intermediate frequency signals containing target distance and speed information, parallel fast Fourier transform and cross spectrum processing are carried out on sampling data of the intermediate frequency signals to achieve parallel synchronous measurement of the target distance and speed, and finally merging and outputting of point cloud images of the N channels are achieved through a main control computer. The invention can effectively overcome the range finding ambiguity and has the advantages of high repetition frequency, large dynamic range finding, high resolution, high precision, high reliability, small volume, light weight and the like.
Description
Technical Field
The invention relates to the technical field of laser radars, in particular to a method and a device for measuring distance and speed of a multi-channel high-repetition-frequency large-dynamic-range laser radar.
Background
The frequency modulation continuous wave laser radar combines the frequency modulation continuous wave distance measurement and the laser detection technology in the modern radar technology. The technology obtains target distance information and radial velocity information by a method of changing the frequency of a transmitting signal linearly in time and measuring the instantaneous frequency of a beat signal of an echo signal and a local oscillator signal. Compared with pulse laser radar, the frequency modulation continuous wave laser radar has the advantages of synchronous distance and speed measurement, large distance/speed measurement range, high resolution, multi-target detection, target imaging and the like, and is widely applied to the fields of automatic driving, high-precision three-dimensional imaging, remote sensing mapping and the like.
However, the chirp frequency modulation continuous wave laser radar still has the following problems: in order to achieve a larger tuning range and thus higher range resolution, the Pulse Repetition Frequency (PRF) is severely limited; the frequency modulation nonlinearity caused by large-range frequency sweep is still an unsolved problem, and the accuracy of speed measurement and distance measurement is seriously influenced; the chirp deskew demodulation requires that the echo signal and the local oscillator signal overlap in the time domain, which determines that the chirp deskew demodulation is not suitable for detection in a large ranging dynamic range.
The schematic diagram of the distance and speed measurement signal of the symmetrical triangular chirp continuous wave coherent lidar shown in fig. 1. Note that the doppler shift is considered here to be much lower than the swept bandwidth, and is shown merely for convenience of illustration. Here, the time T for performing efficient spectral analysis is definedeffTime-domain signal effective overlap ratio η:
when the relative time difference tau between the echo light beam and the local oscillator light beamS-τLWhen the signal frequency difference is small, the echo light beam and the local oscillator light beam can be well overlapped in a linear frequency modulation stage, a fixed frequency difference exists between the echo signal and the local oscillator signal in a detector for a long time, and a high signal-to-noise ratio and a high spectrum resolution ratio can be obtained during spectrum analysis. Effective weightThe overlay ratio η (τ) concept can be used to analyze distance ambiguity:
when tau isS-τLWhen the signal is approximately equal to 0, the echo signal and the local oscillator signal are almost completely overlapped in the same frequency conversion stage, the frequency difference between the echo signal and the local oscillator signal in the frequency conversion stage is always a fixed value, and the effective overlapping proportion is η (0) which is equal to 100%;
when in use
The effective overlap ratio is low, and the signal-to-noise ratio of the obtained signal is low.
When in use
In time, that is, the frequency conversion directions of the echo signal and the local oscillator signal are completely opposite at the same time, and there is no overlap at the same frequency conversion stage, the frequency difference between the echo signal and the local oscillator signal is not fixed, and any effective frequency cannot be analyzed, and the effective overlap ratio is η (± T/2) ═ 0%.
When in use
In the time, the echo signal and the local oscillator signal cannot be partially overlapped with the linear frequency modulation part of the same symmetrical triangular frequency modulation signal in the same frequency conversion direction, and the measurement cannot be carried out, which is called as ranging ambiguity.
The echo-local oscillator frequency difference and the effective overlap ratio caused by the delay are both periodic. The dynamic range of the flight distance detected by the symmetric triangular FMCW lidar system is less than the range allowed by one-half cycle.
Army et al proposed a dual-frequency dual-modulation dual-local oscillator symmetric triangular chirp coherent ranging and speed measuring lidar system, which expanded the range of the symmetric triangular chirp ranging and speed measuring system and had high detection repetition frequency (wuarmy, flood, aspiration, Shurong, a large ranging dynamic range high-repetition frequency coherent ranging and speed measuring lidar (i): system and performance, infrared and millimeter wave academic, 2014, vol.33, No.6,680 and 690); theoretically, the range measurement dynamic range of the system can be increased by prolonging the modulation period of the signal, but on one hand, the mode needs to collect a large number of data points of coherent beat frequency for spectrum analysis during detection, and on the other hand, the modulation time bandwidth product of the symmetric triangular linear frequency modulation needs to be increased, and the long-time high-linearity broadband linear frequency modulation is difficult to realize, so that the complexity of the system is greatly increased, and the application prospect is influenced.
Disclosure of Invention
The invention aims to provide a multi-channel high-repetition-frequency large-dynamic-range distance and speed measuring laser radar method and a device. The invention can effectively overcome the range finding blur and has the advantages of high repetition frequency, large dynamic range finding range, high resolution, high precision, small volume, light weight and the like.
The technical scheme includes that a laser light source in a radar platform generates light beams, the light beams are amplified and then divided into output light beams of N channels through a 1 × N beam splitter, each channel of the output light beams enters a corresponding phase modulator and an optical filter to achieve broadband linear frequency modulation, a radio frequency signal source drives the phase modulator after phase shifting with different amplitudes, the output light beams of each channel have different time delays, the output light beams of each channel are divided into local oscillator light beams and emission light beams through a 1 × 2 beam splitter after frequency shifting is performed on the output light beams of each channel through a frequency shifter, the emission light beams of the N channels are transmitted to a target in parallel through an optical telescope and a light beam director of each channel, complete matching of transmitting/receiving fields of the N channels is achieved, echo light beams of corresponding targets are received at receiving ends of the optical telescopes of the channels, coherent light mixing is performed on the echo light beams and the corresponding local oscillator light beams through an optical bridge, intermediate frequency signals containing target distance and speed information are obtained through balanced receiving, filtering processing and sampling data of the obtained by a central frequency signal, real-time conversion and fast Fourier parallel spectrum measurement of the N channels are achieved, and parallel measurement of the point clouds is achieved, and parallel measurement of the main point cloud measurement is achieved.
The multichannel high-repetition-frequency large-dynamic-range distance and speed measuring laser radar method is used for realizing synchronous measurement of the distance and speed of a target, and specifically comprises the steps of filtering and sampling in-phase signals and orthogonal signals in intermediate-frequency signals, respectively carrying out Fourier transform, carrying out cross-spectrum processing to obtain imaginary parts, extracting the position and the positive and negative of a peak value in a frequency spectrum by using a gravity center method to obtain Doppler frequency shift generated by relative motion of a radar platform and the target, and then obtaining the size and the direction of the radial speed of the relative motion of the radar platform and the target distance by using the Doppler frequency shift.
The laser light source in the radar platform is a narrow-linewidth continuous laser light source, the narrow-linewidth continuous laser light source is polarized by a polarizer and then amplified by a laser amplifier, the narrow-linewidth continuous laser light source is divided into output light beams of N channels by a 1 × N beam splitter, the output light beams of each channel respectively pass through a phase modulator and an optical filter to realize broadband linear frequency modulation, the generated output light beams are continuous coherent laser with frequency linear modulation, symmetrical triangular wave linear modulation is adopted, the frequency of a modulation signal is changed into symmetrical triangular shape along with time, in a period, the first half part is positive frequency modulation, the second half part is negative frequency modulation, wherein a radio frequency signal source drives the phase modulator after phase shifting to realize different time delays of each light beam, then the output light beams of each channel pass through a frequency shifter for frequency shifting, and the light field of the nth path of output light beams after time delay and frequency shifting is expressed as:
wherein t is time, E0Is the amplitude, T is the frequency modulation period, f0Is the frequency-modulated initial frequency, fshift_nIs the amount of frequency shift of the nth output beam,
frequency modulation rate, B frequency modulation bandwidth,
is the phase shift of the nth output beam,
n is a positive integer, Tshift_n∈[0,T)，
φup(n) is the initial phase of the rising segment of the nth output beam pulse, phidown(n) is the initial phase of the falling segment of the nth output beam pulse, exp is an exponential function with a natural constant e as the base,
in the method for measuring distance and speed by using multichannel high-repetition-frequency large-dynamic-range laser radar, the nth output light beam is subjected to time delay and frequency shift and then is split by the 1 × 2 beam splitter, a small part of energy is used as a local oscillation light beam, and the local oscillation light beam is subjected to time delay tauLThe optical field is represented as:
wherein E isLIs the local oscillator beam amplitude, phiLOIs the noise phase of the local oscillator beam;
most energy is used as a transmission beam, the transmission beam passes through the space optical circulator, then is transmitted to a target through the optical telescope and the beam director, and an echo beam of the target is received by the optical telescope, wherein the echo beam is time delay tauSExpressed as:
wherein E isSIs the amplitude of the echo beam, phiSIs the noise phase of the echo beam;
the optical field after the target echo light beam and the local oscillator light beam which are subjected to the same frequency shift are combined is represented as follows:
time delay tau of an echo beamSTime delay tau from local oscillator beamLThe relationship of (c) is expressed as:
where c is the speed of light, R is the distance of the target, V is the radial velocity of the relative motion of the radar platform and the target, and fDopplerIs the Doppler shift caused by the relative motion radial velocity of the radar platform and the target,
the four outputs of the echo light beam and the local oscillator light beam after being mixed by the 2 × 490 degree optical bridge are respectively:
wherein phi isN-nIs the nth output beam mixing noise phase, IsIs a direct current quantity related to the echo beam; i isoIs the direct current quantity related to the local oscillator beam;
the in-phase signal and the orthogonal signal with the orthogonal characteristic output by the optical bridge connector are respectively received by a photoelectric balance detector to obtain an intermediate frequency signal containing target distance and speed information; in the intermediate frequency signal of the forward frequency modulation process, the in-phase signal and the quadrature signal are respectively as follows:
in the intermediate frequency signal of the negative direction frequency modulation process, the in-phase signal and the orthogonal signal are respectively as follows:
wherein k isinIs a photoelectric balance detector receiving in-phase signalsResponse rate, kquIs the response rate, phi, of a photoelectric balanced detector receiving quadrature signalsi-nAnd phiq-nNoise phases of the in-phase signal and the quadrature signal, respectively;
the amplitudes of the in-phase and quadrature channels are replaced by:
the in-phase signal and the quadrature signal in the intermediate frequency signal in the forward frequency modulation process are simplified as follows:
in-phase signals and orthogonal signals in intermediate frequency signals in the negative direction frequency modulation process are simplified as follows:
the in-phase signal and the orthogonal signal are filtered by a low-pass filter respectively, analog-to-digital conversion is completed by an analog-to-digital converter, and then parallel fast Fourier transform is performed by field programmable gate array acquisition, wherein the Fourier transform of the in-phase signal is expressed as:
the orthogonal signal fourier transform is represented as:
performing cross-spectrum processing on the two channels:
finally, only the imaginary part is taken to obtain
Img＝δ2(f-fn)-δ2(f+fn)，
The frequency spectrum peak position and the positive and negative are extracted by a gravity center method, and then the intermediate frequency values in the positive frequency modulation process and the negative frequency modulation process can be respectively obtained:
from the above formula, one can obtain:
in the above formula, fn-upIs the value of the intermediate frequency in the forward frequency modulation process, fn-downIs the intermediate frequency value in the negative frequency modulation process;
because the Doppler frequency is in direct proportion to the relative movement speed of the radar platform and the target, the positive and negative Doppler frequency shifts are related to the direction of the radial speed of the relative movement, the positive frequency shift represents that the radar platform and the target move in the opposite direction, and the negative frequency shift represents that the radar platform and the target move in the opposite direction. Therefore, the magnitude and the direction of the relative motion radial velocity of the radar platform and the target can be obtained by the Doppler frequency shift, and the magnitude and the direction of the relative motion radial velocity of the radar platform and the target can be obtained by the Doppler frequency shift and are expressed as
Where λ is the output beam wavelength, fDopplerDoppler frequency shift caused by the relative motion radial velocity of the radar platform and the target;
the distance to the target point is obtained from the above equation:
The main control computer merges the collected point cloud images of the N channels to obtain a space point set of a target coordinate within a frequency modulation period T:
P(xP_n，yP_n，zP_n) The coordinate position of the target P in the spatial coordinate system detected by the nth channel is taken as the coordinate position of the target P in the spatial coordinate system detected by the nth channel;
the spatial point set ∑ P is the final displayed 3D point cloud image.
In the method for measuring distance and speed by using the multi-channel high repetition frequency large dynamic range laser radar, specifically, the in-phase signal and the quadrature signal are filtered by the low-pass filter to remove the crosstalk signal, where the crosstalk signal is expressed as:
ES_mamplitude of the echo beam, E, expressed as crosstalkLO_nRepresenting the amplitude of the local oscillation light beam corresponding to the nth echo light beam;
the crosstalk signal data includes a frequency of | fshift_n-fshift_mAnd the I term is filtered by a low-pass filter, so that a high-frequency crosstalk signal is eliminated, and the detection precision of the single-path output light beam is improved.
The device for realizing the multichannel high-repetition-frequency large-dynamic-range distance and speed measuring laser radar method comprises a laser light source, wherein the output end of the laser light source is sequentially connected with a polarizer and a laser amplifier, and the output end of the laser amplifier is connected with N phase modulators through a 1 × N beam splitter;
the output end of the optical circulator is sequentially connected with an optical telescope and a light beam director, the optical circulator and the 1 × 2 beam splitter are connected with an optical bridge together, the output end of the optical bridge is sequentially connected with a photoelectric balance detector and a low-pass filter, the low-pass filter is connected with a field programmable gate array through an analog-to-digital converter, the output end of the field programmable gate array is connected with a main control computer, and the main control computer is further connected with the light beam director.
The method comprises the steps of amplifying a light beam generated by a laser source, dividing the amplified light beam into output light beams of N channels through a 1 × N beam splitter, delaying and shifting the output light beams of each channel, dividing the amplified light beams into local light beams and emission light beams through a 1 × 2 beam splitter, transmitting the emission light beams of the N channels to a target in parallel through an optical telescope and a light beam director, realizing complete matching of emission/reception fields of the N channels, receiving echo light beams of the target at a receiving end, performing coherent light mixing with the corresponding local light beams through an optical bridge, obtaining intermediate frequency signals containing target distance and speed information by balanced reception, performing filtering and sampling on the intermediate frequency signals to obtain sampled data, performing real-time parallel fast Fourier transform and cross spectrum processing on the obtained N channel sampled data by using a field programmable gate array, thereby realizing parallel synchronous measurement of target distance and speed, obtaining N intermediate frequency signals containing target distance and speed information of the same target, outputting the intermediate frequency signals in parallel, outputting the same target distance and speed information by using a field programmable gate array, and performing parallel fast Fourier transform and parallel synchronous measurement on the obtained N high-resolution parallel spectrum, thereby realizing the problem of the high-frequency spectrum output of the high-frequency spectrum-frequency-range-output radar, and the high-frequency-range-frequency-range-frequency-range radar system.
Drawings
FIG. 1 is a schematic diagram of a waveform relationship between echo beams and local oscillator beams of a symmetric triangular linear frequency modulation continuous wave coherent laser radar and ranging and speed measurement intermediate frequency signals.
Fig. 2 is a schematic structural diagram of the present invention.
FIG. 3 is a schematic diagram of a symmetric triangular linear frequency modulation waveform and frequency modulation delay;
the reference numbers in the drawing are 1, laser light source, 2, polarizer, 3, laser amplifier, 4, 1 × N beam splitter, 5, phase modulator, 6, frequency shifter, 7, 1 × 2 beam splitter, 8, optical circulator, 9, optical telescope, 10, beam director, 11, optical bridge, 12, photoelectric balance detector, 13, low pass filter, 14, analog-to-digital converter, 15, field programmable gate array, 16, main control computer, 17, phase shifter, 18, radio frequency signal source, 19, optical filter.
Detailed Description
The invention is further illustrated by the following figures and examples, which are not to be construed as limiting the invention.
Embodiment 1. a light beam generated by a narrow linewidth continuous laser light source in a radar platform is amplified and then divided into output light beams of N channels through a 1 × N beam splitter, and the output light beam of each channel respectively passes through a phase modulator and an optical filter to realize broadband linear frequency modulation for subsequent speed measurement and distance measurement, wherein a radio frequency signal source drives the phase modulator after phase shifting to realize different time delays of the output light beam of each channel, namely within a period T, a first path of output light beam is not transmitted in a delayed manner, and a second path of output light beam passes through the phase modulator
Is emitted after time delay, and the third path of output light beam passes through
Is emitted after a delay of … …, the nth output beam passes through
Is transmitted until the last output beam passes through
The method comprises the steps of delaying, transmitting, frequency shifting N delayed output light beams through a frequency shifter respectively, dividing the output light beams into local oscillation light beams and emission light beams through a 1 × 2 beam splitter, transmitting the emission light beams of N channels to a target in parallel through an optical telescope and a light beam director, realizing complete matching of transmitting/receiving fields of N channels, receiving echo light beams corresponding to the target at a receiving end of the optical telescope of each channel, performing coherent light mixing on the echo light beams after passing through an optical circulator and the corresponding local oscillation light beams through an optical bridge, obtaining intermediate frequency signals containing target distance and speed information by adopting balanced receiving, performing filtering processing and sampling processing on the intermediate frequency signals to obtain sampling data, and performing real-time parallel fast Fourier transform and cross spectrum processing on the obtained sampling data of N channels by using a field programmable gate array to realize target parallel fast Fourier transform and cross spectrum processingThe device for realizing the method comprises a laser light source 1 as shown in figure 2, wherein the output end of the laser light source 1 is sequentially connected with a polarizer 2 and a laser amplifier 3, the output end of the laser amplifier 3 is connected with N phase modulators 5 through a 1 × N beam splitter 4, each phase modulator 5 is connected with a phase shifter 17, the N phase shifters 17 are connected with a radio frequency signal source 18 together, the phase modulator 5 is connected with a frequency shifter 6 through an optical filter 19, the output end of the frequency shifter 6 is connected with a 1 × 2 beam splitter 7, and the 1 × 2 beam splitter 7 is connected with an optical circulator 8;
the output end of the optical circulator 8 is sequentially connected with an optical telescope 9 and a light beam director 10, the optical circulator 8 and a 1 × 2 beam splitter 7 are connected with an optical bridge 11 together, the output end of the optical bridge 11 is sequentially connected with a photoelectric balance detector 12 and a low-pass filter 13, the low-pass filter 13 is connected with a field programmable gate array 15 through an analog-to-digital converter 14, the output end of the field programmable gate array 15 is connected with a main control computer 16, the main control computer 16 is further connected with the light beam director 10, and the main control computer is used for controlling the pointing direction of the optical director 10, realizing the merging output of point cloud images of N channels and other sensor data acquisition and decision tasks.
Embodiment 2, a multi-channel high repetition frequency large dynamic range distance measurement and speed measurement laser radar method, as shown in fig. 1, includes a laser light source 1, the laser light source 1 employs a 1550nm single-mode narrow-linewidth continuous fiber laser safe to human eyes, the linewidth of the laser is 10kHz, the output power is 20mW, the output of the optical fiber is isolated and protected, the polarization extinction ratio is ensured to be greater than 25dB by polarizing through a polarizer 2, the laser light is amplified to 600mW through an erbium-doped fiber amplifier 3, then the polarized light is divided into 2 output beams through a 1 × 2 beam splitter 4, each beam passes through an optical fiber phase modulator and an optical filter in sequence, a mixed signal of a frequency modulation signal generated by the frequency modulation signal generator and a fundamental frequency signal generated by the fundamental frequency signal generator is used as a driving signal of the optical fiber phase modulator, the optical fiber phase modulator generates a frequency modulation laser signal, harmonics are suppressed by the optical filter to retain the required order of frequency modulation laser signal, the output beam employs a symmetric triangular wave linear modulation, the frequency of the modulation signal is converted with time, the first half of a cycle is a positive frequency modulation part, the second half of the frequency modulation part is 2 GHz, the second half frequency modulation part is 2 GHz, the phs, the output beam is 0.5, the output beam is output beam, the second half of the second half frequency shift frequency, the second half frequency is 150MHz, the second half frequency shift is shown in the second frequency shift frequency, the second frequency shift graph, the second frequency shift is a frequency shift graph, the second frequency shift;
the optical field of the 2 nd output beam is represented as:
where n is 2, t is time, E0Is the amplitude, T is the frequency modulation period, f0Is the frequency-modulated initial frequency, fshift_nIs the amount of frequency shift of the nth output beam,
frequency modulation rate, B frequency modulation bandwidth,
is the phase shift of the nth output beam,
n is a positive integer, Tshift_n∈[0,T)，
φup(n) is the initial phase of the rising segment of the nth emitted laser pulse, phidown(n) is the initial phase of the n-th falling segment of the emitted laser pulse, exp is an exponential function with a natural constant e as the base,
then, a local oscillation light beam and an emission light beam are emitted out through a 1 × 2 beam splitter 7, the power of each light beam is about 250mW considering insertion loss, the light intensity of two output paths is 1:99, and a small part of energy is used as the speed of the local oscillation light;
as shown in FIG. 3, the local oscillator beam is time delayed τLThe optical field is represented as:
wherein E isLIs the local oscillator beam amplitude, phiLOIs the noise phase of the local oscillator beam; most energy is used as a transmission beam, passes through an optical circulator 8 (an optical fiber three-port circulator), is transmitted to a target through a transmitting/receiving optical telescope 9 and a beam director 8, and is received by the optical telescope to realize the complete matching of transmitting/receiving fields of view of N channels;
echo light beam as time delay tauSThe linear frequency modulated signal of (a); expressed as:
wherein E isSIs the amplitude of the echo beam, phiSIs the noise phase of the echo beam;
the optical field after the target echo light beam and the local oscillator light beam which are subjected to the same frequency shift are combined is represented as follows:
time delay tau of an echo beamSTime delay tau from local oscillator beamLThe relationship of (c) is expressed as:
where c is the speed of light, R is the distance of the target, V is the radial velocity of the relative motion of the radar platform and the target, and fDopplerIs the Doppler shift caused by the relative motion radial velocity of the radar platform and the target,
the four outputs of the echo light beam and the local oscillator light beam after being mixed by the 2 × 490-degree optical bridge 11 are respectively:
wherein phi isN-nIs the nth output beam mixing noise phase, IsIs a direct current quantity related to the echo beam; i isoIs the direct current quantity related to the local oscillator beam;
the in-phase signal and the orthogonal signal with the orthogonal characteristic output by the optical bridge 11 are respectively received by the photoelectric balance detector 12, and an intermediate frequency signal containing target distance and speed information is obtained; in the intermediate frequency signal of the forward frequency modulation process, the in-phase signal and the quadrature signal are respectively as follows:
in the intermediate frequency signal of the negative direction frequency modulation process, the in-phase signal and the orthogonal signal are respectively as follows: :
wherein k isinIs the response rate, k, of a photoelectric balanced detector receiving in-phase signalsquIs the response rate, phi, of a photoelectric balanced detector receiving quadrature signalsi-nAnd phiq-nNoise phases of the in-phase signal and the quadrature signal, respectively;
the amplitudes of the in-phase and quadrature channels are replaced by:
the in-phase signal and the quadrature signal in the intermediate frequency signal in the forward frequency modulation process are simplified as follows:
in-phase signals and orthogonal signals in intermediate frequency signals in the negative direction frequency modulation process are simplified as follows:
the crosstalk signal for the other output beams is expressed as:
ES_mamplitude of the echo beam, E, expressed as crosstalkLO_nRepresenting the amplitude of the local oscillation light beam corresponding to the nth echo light beam;
the crosstalk signal data includes a frequency of | fshift_n-fshift_mThe I term is filtered through a low-pass filter 13, so that high-frequency crosstalk signals are eliminated, and the detection precision of the single-path output light beam is improved;
the in-phase signal and the orthogonal signal are respectively filtered by a low-pass filter 13, analog-to-digital conversion is completed by an analog-to-digital converter 14, and then parallel fast Fourier transform is acquired by a field programmable gate array 15, wherein the Fourier transform of the in-phase signal is represented as:
the orthogonal signal fourier transform is represented as:
performing cross-spectrum processing on the two channels:
finally, only the imaginary part is taken to obtain
Img＝δ2(f-fn)-δ2(f+fn)，
In the main control computer 16, the frequency values in the positive and negative frequency modulation processes can be respectively obtained by extracting the peak position and the positive and negative of the frequency spectrum by a gravity center method:
from the above formula, one can obtain:
in the above formula, fn-upIs the value of the intermediate frequency in the forward frequency modulation process, fn-downIs the intermediate frequency value in the negative frequency modulation process;
because the Doppler frequency is in direct proportion to the relative movement speed of the radar platform and the target, the positive and negative Doppler frequency shifts are related to the direction of the radial speed of the relative movement, the positive frequency shift represents that the radar platform and the target move in the opposite direction, and the negative frequency shift represents that the radar platform and the target move in the opposite direction. Therefore, the magnitude and the direction of the relative motion radial velocity of the radar platform and the target can be obtained by the Doppler frequency shift, and the magnitude and the direction of the relative motion radial velocity of the radar platform and the target can be obtained by the Doppler frequency shift and are expressed as
Where λ is the output beam wavelength, fDopplerDoppler frequency shift caused by the relative motion radial velocity of the radar platform and the target;
the distance to the target point is obtained from the above equation:
The main control computer merges the collected point cloud images of the N channels to obtain a space point set of a target coordinate within a frequency modulation period T:
P(xP_n，yP_n，zP_n) The coordinate position of the target P in the spatial coordinate system detected by the nth channel is taken as the coordinate position of the target P in the spatial coordinate system detected by the nth channel;
the spatial point set ∑ P is the final displayed 3D point cloud image.
The dynamic range of the distance measurement in the embodiment is 1500m, the repetition frequency is 200kHz, and the distance measurement is improved by 1 time compared with the conventional scheme.
In summary, the present invention can obtain N intermediate frequency signals containing target distance and speed information of the same target and output them in parallel, each channel outputs a light beam with different time delay, and then uses the field programmable gate array to perform real-time parallel Fast Fourier Transform (FFT) and cross-spectrum processing on the obtained N intermediate frequency signals, so as to realize parallel synchronous measurement of the target distance and speed, and under a certain repetition frequency, the dynamic range of ranging can be increased by N times; or under a certain ranging dynamic range, the repetition frequency can be increased by N times, so that the method has the advantages of high repetition frequency and large dynamic ranging range; the main control computer realizes the merging output of the point cloud images of the N channels, and realizes high-resolution 3D imaging; the invention adopts the parallel transmission/reception of N output beams, the transmission/reception of each channel output beam is coaxial, the complete matching of the transmission/reception fields of the N channels output beams is realized by adopting a distributed structure, and the system paralysis can not be caused even if the individual channel is damaged, thereby having the advantages of small volume, light weight, high reliability, high resolution, high precision and the like.
Claims (6)
1. A multi-channel high-repetition-frequency large-dynamic-range distance and speed measuring laser radar method is characterized in that a laser light source in a radar platform generates a light beam which is amplified and then divided into output light beams of N channels through a 1 × N beam splitter, each output light beam enters a corresponding phase modulator and an optical filter to achieve broadband linear frequency modulation, a radio frequency signal source drives the phase modulator after phase shifting with different amplitudes, the output light beams of each channel have different time delays, the output light beams of each channel are subjected to frequency shifting through a frequency shifter and then divided into local oscillator light beams and emission light beams through a 1 × 2 beam splitter, the emission light beams of the N channels are emitted to a target in parallel through an optical telescope and a light beam director of each channel, complete matching of emission/reception fields of the N channels is achieved, echo light beams of the corresponding targets are received at receiving ends of the optical telescopes of the channels, coherent light mixing is carried out with the corresponding local oscillator light beams through an optical bridge, intermediate frequency signals containing target distance and speed information are obtained through balanced receiving computers, filtering processing and sampling data of the intermediate frequency signals are filtered and sampled by a programmable gate array, real-time conversion and fast Fourier spectrum parallel measurement of the N channels is achieved, and point cloud parallel measurement is finally achieved.
2. The method of the multi-channel high repetition frequency large dynamic range distance and speed measuring laser radar as claimed in claim 1, wherein: the synchronous measurement of the target distance and the target speed is realized by filtering and sampling an in-phase signal and an orthogonal signal in an intermediate frequency signal, respectively performing Fourier transform, performing cross-spectrum processing to obtain an imaginary part, extracting the position and the positive and negative of a peak value in a frequency spectrum by using a gravity center method to obtain Doppler frequency shift generated by relative motion of the radar platform and the target, and then obtaining the size and the direction of the radial speed of the relative motion of the radar platform and the target distance by using the Doppler frequency shift.
3. The method for measuring the distance and the speed of the laser radar with the multi-channel high repetition frequency and the large dynamic range according to claim 1 is characterized in that a laser light source in the radar platform is a continuous laser light source with a narrow line width, the laser light source is polarized by a polarizer and then amplified by a laser amplifier, the laser light source is divided into output light beams of N channels by a 1 × N beam splitter, the output light beams of each channel respectively pass through a phase modulator and an optical filter to realize broadband linear frequency modulation, the generated output light beams are continuous coherent laser light with frequency linear modulation, symmetrical triangular wave linear modulation is adopted, the frequency of a modulation signal is changed into symmetrical triangular shape along with time, in a period, the front half part is in positive frequency modulation, the rear half part is in negative frequency modulation, wherein a radio frequency signal source drives the phase modulator after phase shifting to realize different time delays of each light beam, then the output light beam of each channel passes through a frequency shifter to shift, and the light field of the nth path of the output light beam:
wherein t is time, E0Is the amplitude, T is the frequency modulation period, f0Is the frequency-modulated initial frequency, fshift_nIs the amount of frequency shift of the nth output beam,
frequency modulation rate, B frequency modulation bandwidth,
is the phase shift of the nth output beam,
k is a positive integer, Tshift_n∈[0,T)，
φup(n) is the initial phase of the rising segment of the nth output beam pulse, phidown(n) is the initial phase of the falling segment of the nth output beam pulse, exp is an exponential function with a natural constant e as the base,
4. the method of claim 3, wherein the nth output beam is delayed and shifted, and then split by a 1 × 2 splitter, and a small portion of energy is used as a local oscillator beam with a time delay τLThe optical field is represented as:
wherein E isLIs the local oscillator beam amplitude, phiLOIs the noise phase of the local oscillator beam;
most energy is used as a transmission beam, the transmission beam passes through the space optical circulator, then is transmitted to a target through the optical telescope and the beam director, and an echo beam of the target is received by the optical telescope, wherein the echo beam is time delay tauSExpressed as:
wherein E isSIs the amplitude of the echo beam, phiSIs the noise phase of the echo beam;
the optical field after the target echo light beam and the local oscillator light beam which are subjected to the same frequency shift are combined is represented as follows:
time delay tau of an echo beamSTime delay tau from local oscillator beamLThe relationship of (c) is expressed as:
where c is the speed of light, R is the distance of the target, V is the radial velocity of the relative motion of the radar platform and the target, and fDopplerIs the Doppler shift caused by the relative motion radial velocity of the radar platform and the target,
the four outputs of the echo light beam and the local oscillator light beam after being mixed by the 2 × 490 degree optical bridge are respectively:
wherein phi isN-nIs the nth output beam mixing noise phase, IsIs a direct current quantity related to the echo beam; i isoIs the direct current quantity related to the local oscillator beam;
the in-phase signal and the orthogonal signal with the orthogonal characteristic output by the optical bridge connector are respectively received by a photoelectric balance detector to obtain an intermediate frequency signal containing target distance and speed information; in the intermediate frequency signal of the forward frequency modulation process, the in-phase signal and the quadrature signal are respectively as follows:
in the intermediate frequency signal of the negative direction frequency modulation process, the in-phase signal and the orthogonal signal are respectively as follows:
wherein k isinIs the response rate, k, of a photoelectric balanced detector receiving in-phase signalsquIs the response rate, phi, of a photoelectric balanced detector receiving quadrature signalsi-nAnd phiq-nNoise phases of the in-phase signal and the quadrature signal, respectively;
the amplitudes of the in-phase and quadrature channels are replaced by:
the in-phase signal and the quadrature signal in the intermediate frequency signal in the forward frequency modulation process are simplified as follows:
in-phase signals and orthogonal signals in intermediate frequency signals in the negative direction frequency modulation process are simplified as follows:
the in-phase signal and the orthogonal signal are filtered by a low-pass filter respectively, analog-to-digital conversion is completed by an analog-to-digital converter, and then parallel fast Fourier transform is performed by field programmable gate array acquisition, wherein the Fourier transform of the in-phase signal is expressed as:
the orthogonal signal fourier transform is represented as:
performing cross-spectrum processing on the two channels:
finally, only the imaginary part is taken to obtain
Img＝δ2(f-fn)-δ2(f+fn)，
The frequency spectrum peak position and the positive and negative are extracted by a gravity center method, and then the intermediate frequency values in the positive frequency modulation process and the negative frequency modulation process can be respectively obtained:
from the above formula, one can obtain:
in the above formula, fn-upIs the value of the intermediate frequency in the forward frequency modulation process, fn-downIs the intermediate frequency value in the negative frequency modulation process;
because the Doppler frequency is in direct proportion to the relative movement speed of the radar platform and the target, the positive and negative Doppler frequency shifts are related to the direction of the radial speed of the relative movement, the positive frequency shift represents that the radar platform and the target move in the opposite direction, and the negative frequency shift represents that the radar platform and the target move in the opposite direction. Therefore, the magnitude and the direction of the relative motion radial velocity of the radar platform and the target can be obtained by the Doppler frequency shift, and the magnitude and the direction of the relative motion radial velocity of the radar platform and the target can be obtained by the Doppler frequency shift and are expressed as
Where λ is the output beam wavelength, fDopplerDoppler frequency shift caused by the relative motion radial velocity of the radar platform and the target;
the distance to the target point is obtained from the above equation:
The main control computer merges the collected point cloud images of the N channels to obtain a space point set of a target coordinate within a frequency modulation period T:
P(xP_n，yP_n，zP_n) The coordinate position of the target P in the spatial coordinate system detected by the nth channel is taken as the coordinate position of the target P in the spatial coordinate system detected by the nth channel;
the spatial point set ∑ P is the final displayed 3D point cloud image.
5. The method of the multi-channel high repetition frequency large dynamic range distance and speed measuring lidar according to claim 4, characterized in that: the in-phase signal and the quadrature signal are filtered by a low-pass filter to remove a crosstalk signal, specifically, the crosstalk signal is represented as:
ES_mamplitude of the echo beam, E, expressed as crosstalkLO_nRepresenting the amplitude of the local oscillation light beam corresponding to the nth echo light beam;
the crosstalk signal data includes a frequency of | fshift_n-fshift_mAnd the I term is filtered by a low-pass filter, so that a high-frequency crosstalk signal is eliminated, and the detection precision of the single-path output light beam is improved.
6. The device for realizing the multi-channel high-repetition-frequency large-dynamic-range distance and speed measuring laser radar method according to any one of claims 1-5 is characterized by comprising a laser light source (1), wherein the output end of the laser light source (1) is sequentially connected with a polarizer (2) and a laser amplifier (3), the output end of the laser amplifier (3) is connected with N phase modulators (5) through a 1 × N beam splitter (4), each phase modulator (5) is connected with a phase shifter (17), the N phase shifters (17) are connected with a radio frequency signal source (18) together, the phase modulator (5) is connected with a frequency shifter (6) through an optical filter (19), the output end of the frequency shifter (6) is connected with a 1 × 2 beam splitter (7), and the 1 × 2 beam splitter (7) is connected with an optical circulator (8);
the output end of the optical circulator (8) is sequentially connected with an optical telescope (9) and a light beam director (10), the optical circulator (8) and a 1 × 2 beam splitter (7) are connected with an optical bridge (11), the output end of the optical bridge (11) is sequentially connected with an optical balance detector (12) and a low-pass filter (13), the low-pass filter (13) is connected with a field programmable gate array (15) through an analog-to-digital converter (14), the output end of the field programmable gate array (15) is connected with a main control computer (16), and the main control computer (16) is further connected with the light beam director (10).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010354911.XA CN111337902B (en) | 2020-04-29 | 2020-04-29 | Multi-channel high-repetition-frequency large-dynamic-range distance and speed measuring laser radar method and device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010354911.XA CN111337902B (en) | 2020-04-29 | 2020-04-29 | Multi-channel high-repetition-frequency large-dynamic-range distance and speed measuring laser radar method and device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111337902A true CN111337902A (en) | 2020-06-26 |
| CN111337902B CN111337902B (en) | 2021-11-23 |
Family
ID=71186531
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010354911.XA Active CN111337902B (en) | 2020-04-29 | 2020-04-29 | Multi-channel high-repetition-frequency large-dynamic-range distance and speed measuring laser radar method and device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111337902B (en) |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111751834A (en) * | 2020-06-30 | 2020-10-09 | 重庆大学 | High-speed high-precision dynamic ranging method based on optical frequency modulation interference and single-frequency interference |
| CN112363146A (en) * | 2020-11-13 | 2021-02-12 | 杭州爱莱达科技有限公司 | Double-modulation common-path linear frequency modulation continuous wave distance and speed measuring method and device |
| CN112649812A (en) * | 2020-11-24 | 2021-04-13 | 中国电子科技集团公司第十一研究所 | Single-pulse multi-channel data processing method and device for non-matched filtering |
| CN113192518A (en) * | 2021-04-14 | 2021-07-30 | 上海交通大学 | Millimeter wave interception method and system |
| CN113589304A (en) * | 2020-09-27 | 2021-11-02 | 北京一径科技有限公司 | Anti-crosstalk processing method and device for laser radar and storage medium |
| CN114466494A (en) * | 2022-01-20 | 2022-05-10 | 南京矽典微系统有限公司 | Intelligent sensing lamp control method, device and equipment |
| CN114879208A (en) * | 2022-06-30 | 2022-08-09 | 北京摩尔芯光半导体技术有限公司 | Frequency modulation continuous wave laser radar system |
| CN115210603A (en) * | 2021-10-20 | 2022-10-18 | 深圳市速腾聚创科技有限公司 | Laser radar and laser radar control method |
| WO2022253102A1 (en) * | 2021-05-31 | 2022-12-08 | 华为技术有限公司 | Optical computing apparatus and method |
| CN117269949A (en) * | 2023-11-22 | 2023-12-22 | 深圳市中图仪器股份有限公司 | Method and device for expanding frequency modulation continuous wave ranging range |
Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202281835U (en) * | 2011-10-18 | 2012-06-20 | 中国科学院上海技术物理研究所 | Submillimetre grade millimeter grade linearity tune laser range finding system |
| CN103412313A (en) * | 2013-07-30 | 2013-11-27 | 桂林理工大学 | Small low-altitude light area array laser radar measuring system |
| CN105137446A (en) * | 2015-09-22 | 2015-12-09 | 中国科学院上海技术物理研究所 | Coherent homodyne Doppler velocity measurement laser radar system based on optical orthogonal demodulation |
| CN105372670A (en) * | 2015-09-22 | 2016-03-02 | 中国科学院上海技术物理研究所 | Coherent homodyne Doppler speed measurement laser radar system on the basis of optics quadrature demodulation |
| CN105510927A (en) * | 2015-11-25 | 2016-04-20 | 中国科学院上海光学精密机械研究所 | Airborne frequency-division laser three-dimensional imaging apparatus and imaging method thereof |
| CN207380238U (en) * | 2017-11-22 | 2018-05-18 | 杭州爱莱达科技有限公司 | A kind of laser radar based on diffraction optics |
| US20190257927A1 (en) * | 2018-02-16 | 2019-08-22 | Xiaotian Steve Yao | Optical sensing based on wavelength division multiplexed (wdm) light at different wavelengths in light detection and ranging lidar systems |
| CN110221292A (en) * | 2019-04-01 | 2019-09-10 | 清华大学 | A kind of microwave photon multiband radar imaging system and method |
| CN110531341A (en) * | 2018-05-26 | 2019-12-03 | 苏州镭智传感科技有限公司 | A kind of FMCW laser radar and its scan method using Broadband FM laser |
| CN110780310A (en) * | 2019-12-31 | 2020-02-11 | 杭州爱莱达科技有限公司 | Polarization diversity dual-channel speed measuring and distance measuring coherent laser radar measuring method and device |
| CN110806586A (en) * | 2020-01-08 | 2020-02-18 | 杭州爱莱达科技有限公司 | Non-scanning linear frequency modulation continuous wave speed and distance measuring laser three-dimensional imaging method and device |
| CN110988864A (en) * | 2019-12-11 | 2020-04-10 | 中国电子科技集团公司第二十研究所 | MTI radar speed measuring method with frequency agility |
| US20200116837A1 (en) * | 2018-10-12 | 2020-04-16 | Silc Technologies, Inc. | Lidar system generating multiple lidar output signals |
| CN111045028A (en) * | 2019-12-11 | 2020-04-21 | 杭州爱莱达科技有限公司 | Voice coherent laser radar interception method and device with motion Doppler frequency shift compensation |
-
2020
- 2020-04-29 CN CN202010354911.XA patent/CN111337902B/en active Active
Patent Citations (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202281835U (en) * | 2011-10-18 | 2012-06-20 | 中国科学院上海技术物理研究所 | Submillimetre grade millimeter grade linearity tune laser range finding system |
| CN103412313A (en) * | 2013-07-30 | 2013-11-27 | 桂林理工大学 | Small low-altitude light area array laser radar measuring system |
| CN105137446A (en) * | 2015-09-22 | 2015-12-09 | 中国科学院上海技术物理研究所 | Coherent homodyne Doppler velocity measurement laser radar system based on optical orthogonal demodulation |
| CN105372670A (en) * | 2015-09-22 | 2016-03-02 | 中国科学院上海技术物理研究所 | Coherent homodyne Doppler speed measurement laser radar system on the basis of optics quadrature demodulation |
| CN205374743U (en) * | 2015-09-22 | 2016-07-06 | 中国科学院上海技术物理研究所 | Relevant homodyne doppler of optics quadrature demodulation laser radar system that tests speed |
| CN105510927A (en) * | 2015-11-25 | 2016-04-20 | 中国科学院上海光学精密机械研究所 | Airborne frequency-division laser three-dimensional imaging apparatus and imaging method thereof |
| CN207380238U (en) * | 2017-11-22 | 2018-05-18 | 杭州爱莱达科技有限公司 | A kind of laser radar based on diffraction optics |
| US20190257927A1 (en) * | 2018-02-16 | 2019-08-22 | Xiaotian Steve Yao | Optical sensing based on wavelength division multiplexed (wdm) light at different wavelengths in light detection and ranging lidar systems |
| CN110531341A (en) * | 2018-05-26 | 2019-12-03 | 苏州镭智传感科技有限公司 | A kind of FMCW laser radar and its scan method using Broadband FM laser |
| US20200116837A1 (en) * | 2018-10-12 | 2020-04-16 | Silc Technologies, Inc. | Lidar system generating multiple lidar output signals |
| CN110221292A (en) * | 2019-04-01 | 2019-09-10 | 清华大学 | A kind of microwave photon multiband radar imaging system and method |
| CN110988864A (en) * | 2019-12-11 | 2020-04-10 | 中国电子科技集团公司第二十研究所 | MTI radar speed measuring method with frequency agility |
| CN111045028A (en) * | 2019-12-11 | 2020-04-21 | 杭州爱莱达科技有限公司 | Voice coherent laser radar interception method and device with motion Doppler frequency shift compensation |
| CN110780310A (en) * | 2019-12-31 | 2020-02-11 | 杭州爱莱达科技有限公司 | Polarization diversity dual-channel speed measuring and distance measuring coherent laser radar measuring method and device |
| CN110806586A (en) * | 2020-01-08 | 2020-02-18 | 杭州爱莱达科技有限公司 | Non-scanning linear frequency modulation continuous wave speed and distance measuring laser three-dimensional imaging method and device |
Non-Patent Citations (3)
| Title |
|---|
| YI YAN ET AL.: "Experimental research of circular incoherently synthetic aperture imaging ladar using chirped-laser and heterodyne detection", 《CHINESE OPTICS LETTERS》 * |
| 吴军 等: "一种大测距动态范围高重频相干测距测速激光雷达(Ⅰ)：体制及性能", 《红外与毫米波学报》 * |
| 吴军 等: "一种大测距动态范围高重频相干测距测速激光雷达(Ⅱ)：信号调制", 《红外与毫米波学报》 * |
Cited By (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111751834B (en) * | 2020-06-30 | 2024-02-20 | 重庆大学 | High-speed high-precision dynamic ranging method based on optical frequency modulation interference and single-frequency interference |
| CN111751834A (en) * | 2020-06-30 | 2020-10-09 | 重庆大学 | High-speed high-precision dynamic ranging method based on optical frequency modulation interference and single-frequency interference |
| CN113589304A (en) * | 2020-09-27 | 2021-11-02 | 北京一径科技有限公司 | Anti-crosstalk processing method and device for laser radar and storage medium |
| CN112363146A (en) * | 2020-11-13 | 2021-02-12 | 杭州爱莱达科技有限公司 | Double-modulation common-path linear frequency modulation continuous wave distance and speed measuring method and device |
| CN112649812B (en) * | 2020-11-24 | 2023-08-15 | 中国电子科技集团公司第十一研究所 | Non-matched filtering single-pulse multi-channel data processing method and device |
| CN112649812A (en) * | 2020-11-24 | 2021-04-13 | 中国电子科技集团公司第十一研究所 | Single-pulse multi-channel data processing method and device for non-matched filtering |
| CN113192518B (en) * | 2021-04-14 | 2023-03-17 | 上海交通大学 | Millimeter wave interception method and system |
| CN113192518A (en) * | 2021-04-14 | 2021-07-30 | 上海交通大学 | Millimeter wave interception method and system |
| WO2022253102A1 (en) * | 2021-05-31 | 2022-12-08 | 华为技术有限公司 | Optical computing apparatus and method |
| CN115210603A (en) * | 2021-10-20 | 2022-10-18 | 深圳市速腾聚创科技有限公司 | Laser radar and laser radar control method |
| WO2023065149A1 (en) * | 2021-10-20 | 2023-04-27 | 深圳市速腾聚创科技有限公司 | Laser radar and laser radar control method |
| CN114466494A (en) * | 2022-01-20 | 2022-05-10 | 南京矽典微系统有限公司 | Intelligent sensing lamp control method, device and equipment |
| CN114879208A (en) * | 2022-06-30 | 2022-08-09 | 北京摩尔芯光半导体技术有限公司 | Frequency modulation continuous wave laser radar system |
| CN114879208B (en) * | 2022-06-30 | 2022-11-01 | 北京摩尔芯光半导体技术有限公司 | Frequency modulation continuous wave laser radar system |
| CN117269949A (en) * | 2023-11-22 | 2023-12-22 | 深圳市中图仪器股份有限公司 | Method and device for expanding frequency modulation continuous wave ranging range |
| CN117269949B (en) * | 2023-11-22 | 2024-02-13 | 深圳市中图仪器股份有限公司 | Method and device for expanding frequency modulation continuous wave ranging range |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111337902B (en) | 2021-11-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111337902B (en) | Multi-channel high-repetition-frequency large-dynamic-range distance and speed measuring laser radar method and device | |
| CN105629258B (en) | Test the speed range-measurement system and method based on pseudo-random code phases modulation and heterodyne detection | |
| CN106707291B (en) | Double-frequency linear frequency modulation coherent wind lidar | |
| CN110780310B (en) | Polarization diversity dual-channel speed measuring and distance measuring coherent laser radar measuring method and device | |
| US10330778B2 (en) | Coherent lidar system using tunable carrier-suppressed single-sideband modulation | |
| CN110806586B (en) | Non-scanning linear frequency modulation continuous wave speed and distance measuring laser three-dimensional imaging method and device | |
| CN111693988A (en) | Laser millimeter wave integrated distance and speed measuring radar method and device | |
| EP3637134B1 (en) | Laser radar device | |
| US5889490A (en) | Method and apparatus for improved ranging | |
| US7342651B1 (en) | Time modulated doublet coherent laser radar | |
| CN110376607B (en) | Synthetic aperture laser radar system | |
| CN111650601B (en) | High-resolution 3D imaging method and device for vehicle-mounted coherent laser radar | |
| CN111999739A (en) | Coherent laser radar method and device for measuring distance and speed by phase modulation | |
| CN110794421B (en) | Pseudo-random code time delay self-differential interference three-dimensional imaging laser radar method and device | |
| CN108303704B (en) | Laser measurement method based on polarization modulation and laser radar | |
| WO2021036315A1 (en) | Microwave and laser radar integration method and apparatus | |
| CA3048330A1 (en) | Method for processing a signal from a coherent lidar in order to reduce noise and related lidar system | |
| CN114035174A (en) | Double-channel double-chirp linear frequency modulation continuous wave laser radar method and device | |
| CN112363146B (en) | Distance and speed measuring method and device for dual-modulation common-path linear frequency modulation laser radar | |
| CN112799090B (en) | Frequency reuse solid-state laser radar detection method and system | |
| CN112327319A (en) | Solid-state laser radar detection method and system based on cyclic frequency shift ring | |
| CN208367213U (en) | Using the Twin-beam laser Doppler velocity system of phase-modulator | |
| CN104111450A (en) | Method and system for detecting object micro Doppler characteristics by use of double pulses | |
| CN102004243A (en) | Optical bridging heterodyne reception and complex value processing system for synthetic aperture laser imaging radar | |
| CN116106917A (en) | Parallel linear frequency modulation continuous wave laser radar ranging and speed measuring system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20220921 Address after: Room 1803, No. 12, Lane 333, Hongshi Road, Juyuan New District, Jiading District, Shanghai, 201800 Patentee after: Sun Jianfeng Address before: 310053 room 701, block B, 581 torch Avenue, Puyan street, Binjiang District, Hangzhou City, Zhejiang Province Patentee before: HANGZHOU ILIDAR TECHNOLOGY CO.,LTD. |