Quantum lidar dynamic gating real-time detection system and signal processing method

Abstract

The application discloses a quantum laser radar dynamic gating real-time detection system and a signal processing method, and relates to the technical field of quantum laser radars.The system comprises a laser emission system, a return wave receiving system, an adaptive environment detection module, a gating timing control module and a signal processing module; the laser emission system is connected with the gating timing control module in signal transmission; the return wave receiving system is connected with the gating timing control module and the signal processing module; the adaptive environment detection module is connected with the gating timing control module and the signal processing module; and the gating timing control module and the signal processing module are connected with each other to form a double-closed-loop feedback channel.The application realizes real-time adaptive detection in a complex environment through a double-feedback dynamic gating mechanism, effectively suppresses background noise and improves ranging accuracy.

Description

Technical Field

[0001] This application belongs to the field of quantum lidar technology, specifically relating to a dynamic gating real-time detection system and its signal processing method for quantum lidar, particularly suitable for high-precision ranging and multi-target detection in low-light environments. The "quantum lidar" referred to in this application mainly refers to a lidar system based on single-photon detection for target echo acquisition and processing; in some embodiments, the system can be further extended to include a quantum correlation light source or a quantum interference detection link to enhance noise suppression and weak echo detection capabilities. Because this application employs a single-photon detection and time-correlated single-photon counting processing mechanism to achieve high-sensitivity detection of target echoes, it belongs to a lidar system based on a quantum detection system. Background Technology

[0002] With the development of quantum information and high-precision lidar technology, quantum lidar, due to its high sensitivity and millimeter-level resolution, has been widely used in underwater detection, spatial identification, and environmental monitoring. Quantum lidar combines single-photon detection technology with efficient photon counting methods, enabling high-precision three-dimensional ranging and imaging in complex environments.

[0003] Patent CN120652428A proposes a radar system based on quantum entangled photons, which can adjust optical parameters to cope with different weather environments. However, existing gating strategies still have insufficient detection efficiency and signal processing capabilities in multi-target scenarios, and charged sand particles, haze, and other particles affect the resolution and sensitivity of the radar system.

[0004] Patent CN119335556A proposes an underwater single-photon lidar imaging method based on a gated SPAD array. This method can effectively improve the depth imaging capability of the radar under certain conditions, especially demonstrating millimeter-level accuracy in high-precision 3D target reconstruction. However, the gating strategy is fixed and lacks a dynamic adjustment mechanism, resulting in insufficient detection efficiency and real-time signal processing capabilities in complex environments.

[0005] The paper "The Influence of Charged Sand Particles on Quantum Interference Radar and Simulation," published in the *Journal of Quantum Electronics*, proposes a performance optimization scheme for quantum interference radar. This scheme analyzes the scattering and absorption effects of charged sand particles on radar signals through simulation and optimizes real-time signal processing and signal-to-noise ratio using quantum interference effects, significantly improving detection capabilities in harsh environments such as sandstorms. However, the dynamic changes and environmental distribution of the charged sand particles in this method are complex, resulting in a heavy computational burden on real-time signal processing and optimization algorithms. Especially when the number of targets increases, balancing processing speed and accuracy remains a challenge, affecting the overall real-time detection capability of the system. Summary of the Invention

[0006] The purpose of this application is to provide a quantum lidar dynamic gating real-time detection system and signal processing method to solve the problems of low detection efficiency, decreased signal-to-noise ratio, and limited real-time multi-target detection capability of existing quantum lidars in complex environments.

[0007] To achieve the above objectives, this application provides the following technical solution: In a first aspect, this application provides a quantum lidar dynamic gating real-time detection system, comprising: a laser emitting system, an echo receiving system, and a control and signal processing system. The control and signal processing system includes an adaptive environment detection module, a gating timing control module, and a signal processing module. The adaptive environment detection module is connected to both the gating timing control module and the signal processing module; the gating timing control module is connected to the laser emitting system, the echo receiving system, the adaptive environment detection module, and the signal processing module; and the signal processing module is connected to the echo receiving system, the adaptive environment detection module, and the gating timing control module.

[0008] The laser emission system is used to generate laser pulses with a high repetition frequency of 50MHz to 150MHz and a pulse width of less than 200ps, and to emit the laser pulses to the target area, and output a laser trigger signal synchronized with the emission of the laser pulses; the laser pulses are reflected by the target area to form an echo signal, which serves as the input signal for single-photon detection.

[0009] The echo receiving system is used to receive the echo signal and convert it into an electronic time signal. The time signal is transmitted to the gated timing control module via a signal interface and simultaneously fed back to the signal processing module to construct a photon arrival time histogram and record photon event data, thereby achieving quantum-level high-sensitivity detection.

[0010] The adaptive environment detection module includes an ambient light sensor, an atmospheric scattering measurement device, and an inertial measurement unit. It acquires ambient light intensity, atmospheric scattering coefficient, and the system's pitch, yaw, and roll attitude information to generate environmental perception indicators. These indicators are transmitted digitally to the gating timing control module and the signal processing module, which dynamically adjust the gating window width and delay time, and optimize the signal processing strategy to achieve adaptive detection in complex environments.

[0011] The signal processing module, based on the time-correlated single-photon counting principle, uses the laser triggering time as the starting reference to accumulate and statistically analyze the arrival times of echo photon events to form a photon arrival time histogram. It then uses a feature extraction algorithm to calculate target parameters such as target distance, signal-to-noise ratio, and relative velocity, extracts the time-domain position features of the echo main peak in the photon arrival time histogram, and feeds the processing results back to the gating timing control module to dynamically adjust the gating window width and delay time. This enables the quantum lidar to achieve real-time adaptive detection and closed-loop control in complex environments.

[0012] The gate timing control module is built on a field-programmable gate array (FPGA). Based on the received laser trigger signal, the environmental perception indicators, the echo peak time-domain position characteristics and signal-to-noise ratio information fed back by the signal processing module, it jointly calculates the gate delay time and gate window width, generates a dynamic gate signal, and synchronously controls the sampling window of the echo receiving system. The echo receiving system collects photon event data within this window and transmits the time signal to the signal processing module to form a real-time photon arrival time histogram, thereby realizing closed-loop control.

[0013] In some embodiments, the gating timing control module includes a field-programmable gate array (FPGA) with an embedded adaptive time gating algorithm. The adaptive time gating algorithm compares the time characteristics of the laser trigger signal output by the laser emitting system with the echo signal. Combining the environmental perception indicators and the echo peak time-domain position characteristics and signal-to-noise ratio information fed back by the signal processing module, it calculates and dynamically corrects the gating delay time and gating window width in real time, aligning the center of the gating pulse with the peak of the echo signal.

[0014] Secondly, this application provides a signal processing method for a quantum lidar dynamic gating real-time detection system, the method being applicable to the aforementioned system, and comprising the following steps: The laser emission system generates high-repetition-frequency and narrow-pulse-width laser pulses and irradiates the target area, while simultaneously outputting a laser trigger signal synchronized with the laser pulse emission. The laser pulses are reflected by the target area to form an echo signal. The adaptive environment detection module collects ambient light intensity, atmospheric scattering coefficient and system attitude angle information, and generates environmental perception indicators. The gating timing control module receives the laser trigger signal and, based on the environmental perception indicators and the echo main peak time domain position characteristics and signal-to-noise ratio information fed back by the signal processing module in the previous detection cycle, jointly calculates the gating delay time and gating window width of the current detection cycle, generates a dynamic gating signal, and sends it to the echo receiving system. The echo receiving system receives echo signals from the target area under the control of the dynamic gating signal, and performs single-photon detection on the echo signals to generate photon event data. The signal processing module performs time statistics processing on the photon event data, constructs a photon arrival time histogram, and extracts target distance, signal-to-noise ratio, and echo main peak time domain location features. The gating timing control module updates the gating delay time and gating window width for the next detection cycle based on the echo peak time domain location characteristics, signal-to-noise ratio, and environmental perception indicators obtained in the current detection cycle, so as to form a dual closed-loop optimization based on detection result feedback and environmental parameter feedback.

[0015] According to the specific embodiments provided in this application, the following technical effects are achieved: This application introduces a dynamic gating and dual-feedback closed-loop mechanism, enabling the quantum lidar to adjust the gating window width and delay time in real time based on echo signals and environmental perception indicators, and optimize signal processing strategies for different environmental conditions. This is particularly relevant in situations with strong background light, ambient light intensity greater than 30 klx, and a scattering coefficient less than 0.2 km. -1 In environments with low visibility, visibility below 2km, or scattering coefficient greater than 0.8km, the system automatically compresses the gating window to within 5ns to suppress noise; while in low visibility, visibility below 2km, or scattering coefficient greater than 0.8km... -1 In this environment, the system extends the gating window to 15 ns to improve the ability to capture broadened echoes. This adaptive adjustment effectively suppresses noise under complex backgrounds and low-light conditions, improves photon event utilization, and enables accurate differentiation and parallel detection of multi-target echoes, avoiding signal overlap or crosstalk, thereby maintaining high-precision real-time ranging and imaging capabilities. This scheme overcomes the problems of signal loss and performance degradation in traditional fixed-gating modes, significantly improving the detection performance and environmental adaptability of the quantum lidar system, and possesses the technical advantages of simple structure and easy system integration. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A schematic diagram of the quantum lidar dynamic gating real-time detection system provided in this application; Figure 2 A schematic diagram of the echo receiving system provided in this application; Figure 3A schematic diagram illustrating the generation of the photon arrival time histogram provided in this application; Figure 4 A schematic diagram of the dynamic gated dual feedback closed-loop control structure provided in this application; Figure 5 This is a schematic diagram of the dynamic gating pulse signal waveform provided in this application; Figure 6 A schematic diagram of the time series of synchronous signal acquisition and processing provided in this application; Figure label: 101: Laser emission system; 102: Echo reception system; 103: Adaptive environment detection module; 104: Gated timing control module; 105: Signal processing module; 201: Pulsed laser; 202: Single-photon avalanche diode array (SPAD array); 203: Quenching circuit; 204: Low-pass filter; 205: Amplifier; 206: Time-to-digital converter; 207: Gating control circuit; 208: Synchronous triggering link; 209: Bandpass filter. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] This application provides a quantum lidar dynamic gating real-time detection system, which includes a laser emission system, an echo receiving system, and a control and signal processing system. Specifically, the control and signal processing system includes an adaptive environment detection module, a gating timing control module, and a signal processing module. This structure achieves environmentally adaptive closed-loop detection through the physical connection and signal flow of each module.

[0020] The laser emitting system is used to generate laser pulses with a high repetition frequency of 50MHz to 150MHz and a narrow pulse width of less than 200ps to provide a stable light source for the target area; it is also used to output a laser trigger signal to the gating timing control module to achieve time alignment and trigger control with the echo receiving system and the signal processing module.

[0021] The echo receiving system includes a receiving optical path and a SPAD array for highly sensitive detection of echo signals reflected from a target area. The SPAD array comprises multiple independent detection pixels, each capable of inducing an avalanche breakdown effect upon single-photon incidentity, generating a well-defined electronic pulse signal, achieving single-photon level detection. The echo receiving system also limits the detection time window under external gate control signals to avoid interference from background noise photons or non-target scattered photons, thereby selectively acquiring effective echo signals and ensuring a high signal-to-noise ratio even in complex environments.

[0022] The adaptive environment detection module includes an ambient light sensor, an atmospheric scattering measurement device, and an inertial measurement unit, used to collect ambient light intensity, scattering coefficient, and system attitude angle information in real time and generate environmental perception indicators. The output of the ambient light sensor is preprocessed by the local microprocessor after analog-to-digital conversion by the analog front-end, and then transmitted to the gating timing control module and signal processing module through a standard interface.

[0023] The gating timing control module, built on a field-programmable gate array (FPGA), is used to generate and send dynamic gating signals based on feedback from the signal processing module, environmental perception indicators, and laser trigger signals, so as to precisely control the sampling window of the echo receiving system; it is also used to coordinate the working timing of the laser emitting system and the echo receiving system to cooperate with the signal processing module to complete closed-loop control.

[0024] The signal processing module is used to analyze the gated photon event data and photon arrival time histogram, extract parameters such as target distance, signal-to-noise ratio and relative velocity, and feed the results back to the gated timing control module to achieve closed-loop optimization control.

[0025] The FPGA internally deploys an adaptive time gating algorithm to update the gating delay time and gating window width in real time based on environmental perception indicators and the echo main peak time domain location characteristics and signal-to-noise ratio information fed back by the signal processing module.

[0026] The technical solution of this application will be further illustrated below with specific examples.

[0027] In this embodiment, the quantum lidar dynamic gating real-time detection system is suitable for long-range detection in low-visibility atmospheric environments. The system illuminates the target area by emitting short-pulse lasers. When the laser encounters the target area or atmospheric particles, it is scattered, and a portion of the echo signal is received by the echo receiving system. The laser emitting system generates laser pulses with a center wavelength of approximately 1550 nm, a pulse width of 150 ps, ​​a repetition frequency of 100 MHz, and an average emission power of 200 mW to meet the requirements of high-precision time-of-flight measurement. The SPAD array in the echo receiving system has a quantum efficiency greater than 65% and a dark count rate less than 100 cps, enabling precise recording of photon arrival timestamps.

[0028] like Figure 1 As shown, the quantum lidar dynamic gating real-time detection system provided in this application includes: a laser emitting system 101, an echo receiving system 102, an adaptive environment detection module 103, a gating timing control module 104, and a signal processing module 105. The laser emitting system 101 outputs a laser trigger signal to the gating timing control module 104 and the signal processing module 105. The echo receiving system 102 detects the echo signal of the target area under external gating control. The adaptive environment detection module 103 acquires environmental perception indicators and inputs them to the gating timing control module 104 and the signal processing module 105. The gating timing control module 104 generates a dynamic gating signal based on feedback to control the effective detection time window of the echo receiving system 102. The signal processing module 105 performs statistical analysis and feature extraction on the photon event data.

[0029] like Figure 2 As shown, the echo receiving system provided in this application includes: a receiving optical path, a SPAD array 202, a quenching circuit 203, a low-pass filter 204, an amplifier 205, a time-to-digital converter 206, and a gating control circuit 207. The receiving optical path is positioned between the target region and the SPAD array 202, and is used to receive the echo signal reflected from the target region and couple it to the SPAD array 202. The SPAD array 202 is used to perform single-photon detection on the echo signal under dynamic gating signal control and output a photon event signal.

[0030] The laser emission system includes a pulsed laser 201 and an emission optical path. The emission optical path is located on the output side of the pulsed laser 201 and is used to emit laser pulses to the target area. The pulsed laser 201 is also used to provide a synchronous trigger reference signal to the gating control circuit 207 and the time-to-digital converter 206 to establish a timing correspondence between the transmitter and receiver.

[0031] When the target echo light signal is incident on the SPAD array 202, it triggers avalanche breakdown in the corresponding pixel, thereby outputting an electrical signal pulse characterizing the arrival time of the photon. The electrical signal is first input to the quenching circuit 203 to quickly terminate the avalanche process and reset the pixel after the avalanche is triggered, so as to restore its subsequent detection capability.

[0032] The quenched electrical signal is processed sequentially through a filtering circuit and an amplification circuit. The filtering circuit preferably includes a low-pass filter 204 to suppress high-frequency noise components; the amplification circuit preferably includes an amplification circuit 205 to amplify the amplitude of the effective signal, thereby improving the accuracy of subsequent processing. The processed signal is then sent to a time-to-digital converter 206 for time quantization to obtain the time-of-flight information of the echo signal. Preferably, the time resolution of the time-to-digital converter 206 is better than 30 ps.

[0033] The gating control circuit 207 is used to generate a dynamic gating signal synchronized with the laser emission and apply it to the gating terminal of the SPAD array 202 to control its opening and closing timing, so that the detector is only in an effective detection state within a preset time window, thereby reducing the impact of background light noise and dark counting on measurement accuracy.

[0034] Furthermore, to achieve high-precision time synchronization between the transmitter and receiver, the system is equipped with a synchronization trigger link 208, which is used to establish the timing relationship between the pulse laser 201, the gating control circuit 207 and the time-to-digital converter 206, thereby ensuring the accuracy of the time of flight measurement.

[0035] In a preferred embodiment, the gate drive signal output by the gate control circuit 207 is amplitude modulated by the gate drive stage and then spectral sculpted by the bandpass filter 209 to obtain a gate drive signal in an approximately sinusoidal form. This sinusoidal signal is applied to the gate terminal of the SPAD array 202 to achieve smooth gate drive, thereby reducing transient noise introduced during the gate control process and improving the system's signal-to-noise ratio and ranging accuracy.

[0036] Through the above structural design, this application can effectively suppress background light interference while ensuring high temporal resolution, thereby improving the detection performance of the lidar system in complex lighting environments.

[0037] Combination Figure 6The timing diagram shows the system workflow as follows: The system uses the global master clock signal clk as the time reference. Under this time reference, the laser emission system outputs a laser trigger signal Trig, synchronized with the laser pulse emission, and sends the Trig signal to the gating timing control module and the signal processing module. The laser emission system outputs a laser pulse signal Pulse from time t1 to t2 according to the preset emission sequence, thereby illuminating the target area.

[0038] Simultaneously, the gating timing control module, based on feedback from the signal processing module, environmental perception indicators, and preset delay parameters, delays the laser emission by [specific parameters]. The time-controlled gate window (Gate) is activated to control the SPAD array to operate within a specified time period, effectively shielding background light and non-target scattered signals. When the target reflected echo signal (Echo) returns between times t3 and t4 and falls within the gate window determined by the gate delay time and the gate window width, the SPAD array is activated, triggering photon event output.

[0039] The signal processing module uses the laser trigger signal Trig as a time reference to measure and statistically analyze the time of echo photon events, obtaining the time difference of flight. The signal processing results are then used to calculate the target distance and signal-to-noise ratio. The signal processing results are transmitted to the gating timing control module via a feedback channel to adjust the gating delay time and gating window width for the next cycle, achieving adaptive timing optimization of the closed loop.

[0040] To cope with complex environments, this embodiment constructs an adaptive dynamic correction model based on multi-source parameter fusion. The gating control program uses the signal-to-noise ratio fed back in real time by the signal processing module. The ambient light intensity provided by the adaptive environment detection module Atmospheric scattering coefficient and historical statistical confidence weights Parameters such as these dynamically adjust the width of the gated window. With delay time The improved model incorporates an environmental fluctuation index. The value is determined by the rate of change of ambient light intensity and the volatility of the scattering coefficient, ranging from 0 to 1. When the environmental volatility index... When the value is greater than 0.5, the system automatically reduces the smoothing coefficient and increases the gate window width to prevent echo signal loss. A signal-to-noise ratio factor is also introduced. (Values ​​range from 0.5 to 1.5), enabling the algorithm to withstand noise. In extreme cases, such as continuous frame drops, the system estimates the main peak of the echo based on the Kalman prediction mechanism. The drift amount is used to adjust the gating center for the next sampling period in advance.

[0041] Among them, the environmental fluctuation index The calculation formula is as follows: in, and These are the ambient light intensities measured by the ambient light sensor at the current time and the previous time, respectively, in klx. and Atmospheric scattering coefficient, unit: km. -1 α and β are preset weighting coefficients of the system, representing the contribution of changes in ambient light intensity and atmospheric scattering coefficient to the degree of environmental degradation during detection, respectively. In this embodiment, after extensive experimental calibration, α is set to 0.38 and β to 0.62. The value of β is higher than that of α because, in quantum lidar detection, the impact of photon attenuation and echo broadening caused by atmospheric scattering on detection performance is usually more drastic than simple changes in background light intensity. Giving the scattering coefficient a higher weight makes the system more sensitive to situations where visibility decreases, such as sudden entry into fog, thus allowing for more timely adjustment of the gating parameters. This formula quantifies the degree of drastic environmental change; when entering a fog area on a clear day... It will increase significantly.

[0042] Dynamic gating width Calculation formula: in, The base door width is set to 4.8 in this embodiment. ; The environmental sensitivity coefficient is set to 1.47. The signal-to-noise ratio of the current frame is fed back by the signal processing module 105; The safe signal-to-noise ratio threshold is set to 14.8. ; This is the attenuation adjustment factor, set to 0.83. This value is based on the fact that when the signal-to-noise ratio reaches 14.8 dB, the system can extract valid target echoes with a confidence level higher than 90% to avoid false alarms; at this point, the system is capable of narrowing the gate width. The attenuation adjustment factor is set to 0.83. This value determines the rate at which the gate width shrinks when the signal-to-noise ratio is better than the threshold. If the value is too large, the gate width may shrink too quickly and miss the effective signal. If the value is too small, the background noise cannot be filtered out in time. 0.83 is the empirically optimal solution for balancing background suppression and signal preservation.

[0043] The physical meaning of this formula is that when the environment changes drastically, the system actively widens the gate to prevent the target from being lost; while when the current signal-to-noise ratio is excellent, the exponential term comes into play, and the system automatically narrows the gate to filter out background noise to the extreme.

[0044] Gating delay time Calculation formula: in, The speed of light; The distance to the target in the previous frame; The target relative velocity; The detection period is 10 ns in this example. The factor for compensating for the delay broadening caused by atmospheric scattering is set to 0.48. ; The velocity prediction compensation factor is set to 0.95. This formula utilizes conventional time-of-flight distance prediction and innovatively incorporates optical path widening compensation due to atmospheric scattering, ensuring that the gating center can still accurately align with the echo peak even in dense fog conditions.

[0045] To verify the effectiveness of the model, this application provides specific embodiments and implementation data under three typical environmental conditions: Scenario 1, strong background light conditions: such as a sunny day with direct sunlight. When the ambient light intensity is greater than 30 klx and the scattering coefficient is less than 0.2 km. -1 When the system detects strong background light, the gating timing control module compresses the gating window width to within 5 ns. The closed-loop adjustment step size is set to 0.1 ns. This adjustment method is because single-photon detectors have a dead time. If the window is too wide, background photons are likely to trigger the detector before the signal photons, causing it to enter the dead time. Compressing the window to within 5 ns and precisely aligning it with the expected echo time can effectively avoid a large number of randomly arriving background photons, thereby greatly reducing invalid triggering events caused by background photons. In the measurement verification, when detecting a target at 1000 meters, the ranging signal-to-noise ratio of the traditional 10 ns fixed gate width method is only 5 dB. However, after adopting the strategy of this application, the measured signal-to-noise ratio reaches 20.2 dB, the false alarm rate is reduced to below 2%, and the ranging error is controlled within ±5 cm, improving the ranging signal-to-noise ratio under strong light by at least 15 dB.

[0046] Scenario 2, Moderate visibility conditions: such as ordinary cloudy days or light fog. When visibility is approximately 5km, the corresponding scattering coefficient is approximately 0.4km. -1 In this mode, the system automatically maintains the gating window width at 8 ns and sets the closed-loop adjustment step size to 0.5 ns. This eliminates the need for extremely high-frequency gating switching to suppress strong light, reducing the dynamic power consumption of the high-frequency circuit, and also eliminates the need for excessively long gate widths to capture extremely weak signals, reducing the accumulation of dark counts and the burden on temperature control of the detector. Therefore, it ensures both detection efficiency and low-power operation. Actual measurement data shows that in this state, the overall power consumption of the system is reduced by approximately 30% compared to the strong light mode, while the detection probability for targets at 5000 meters remains stable at over 95%, and the ranging accuracy reaches ±10 cm.

[0047] Scenario 3: Low visibility conditions, such as fog, haze, or rain / snow. When visibility is below 2km, the corresponding scattering coefficient is greater than 0.8km. -1 When the signal-to-noise ratio (SNR) is below 14.8 dB, signal attenuation is severe. The system automatically extends the gating window width to 15 ns through the outer loop feedback path and combines multi-frame data fusion to compensate for signal attenuation. This is because when there are very few echo photons in a single frame, the target signal is correlated on the time axis while the background noise is randomly distributed. By accumulating histograms across multiple frames, the effective signal can be superimposed and enhanced while the noise is averaged, thus significantly improving the SNR. Actual measurement data shows that in dense fog with a visibility of 1.5 km, the traditional method has a detection probability of less than 30% for a 2000-meter target. However, after adopting the extended gating and multi-frame fusion strategy of this application, the measured SNR is improved by approximately 8 dB, the detection probability is increased to over 90%, and the ranging error remains within ±20 cm, ensuring complete extraction and continuous locking of the target echo signal.

[0048] like Figure 3 As shown, the horizontal axis of the photon arrival time histogram provided in this application represents the time delay, and the vertical axis represents the photon count. The signal processing module determines the main peak time of the echo signal by mathematically fitting the histogram and calculates the target distance accordingly. For multi-peak echoes, the gating timing control module identifies the echo peak positions corresponding to different targets based on the multiple local peak characteristics in the photon arrival time histogram, and generates gating timing sequences and independent gating windows corresponding to multiple targets to achieve parallel detection of multiple targets.

[0049] Specifically, the gating timing control module includes multi-target timing allocation logic, which is used to analyze the multiple local peak features and allocate corresponding gating timing according to the time domain position of each echo peak, thereby realizing the parallel detection of multiple target echoes.

[0050] Furthermore, during the continuous detection cycle, when the time-domain position characteristics of the echo peak are weakened or the signal-to-noise ratio is lower than a preset threshold, the gating timing control module adaptively expands the gating window width to improve the ability to capture weak or broadened echoes. After re-stabilizing the capture of the echo peak, the gating window width and gating delay time are converged and adjusted according to the updated echo characteristics.

[0051] like Figure 4 As shown, the control system provided in this application achieves coordinated optimization through inner and outer loop feedback paths. The inner loop feedback is based on real-time gating adjustment of the echo signal; the outer loop feedback is based on slow time-varying correction of environmental perception indicators, ensuring stable detection of the system under complex weather conditions such as strong light, rain, and snow.

[0052] like Figure 5As shown, the dynamic gating pulse signal waveform provided in this application is adaptively adjusted in real time according to environmental perception indicators and echo characteristics to accurately limit the effective detection time window of the echo receiving system.

[0053] like Figure 6 As shown, this timing diagram illustrates the timing synchronization relationship between the laser emission system, the gating timing control module, the echo receiving system, and the signal processing module. Each module completes laser triggering, dynamic gating, echo acquisition, time statistics, and feedback updates under a unified clock reference, thereby achieving closed-loop adaptive adjustment of the gating delay time and the gating window width.

[0054] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0055] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A quantum lidar dynamic gating real-time detection system, characterized in that, include: A laser emitting system is used to generate laser pulses with a repetition frequency of 50MHz to 150MHz and a pulse width of less than 200ps, and to emit the laser pulses to a target area, and to output a laser trigger signal synchronized with the emission of the laser pulses; An echo receiving system is used to receive echo signals reflected from a target area and to perform single-photon detection on the echo signals to generate photon event data. A control and signal processing system, comprising an adaptive environment detection module, a gated timing control module, and a signal processing module; the adaptive environment detection module is connected to both the gated timing control module and the signal processing module; the gated timing control module is connected to the laser emission system, the echo reception system, the adaptive environment detection module, and the signal processing module; the signal processing module is connected to both the echo reception system, the adaptive environment detection module, and the gated timing control module. The adaptive environment detection module is used to collect ambient light intensity, atmospheric scattering coefficient and system attitude angle information in real time, and generate environmental perception indicators. The signal processing module is used to perform time statistical processing on the photon event data, construct a photon arrival time histogram, extract target parameters such as target distance, signal-to-noise ratio and relative velocity, extract the time domain position features of the echo main peak, and feed the processing results back to the gated timing control module. The gating timing control module is used to receive the laser trigger signal, and based on the environmental perception index, the echo main peak time domain position characteristics and signal-to-noise ratio information fed back by the signal processing module, jointly calculate the gating delay time and gating window width, generate a dynamic gating signal, and send it to the echo receiving system so that the center of the gating window is aligned with the echo main peak time domain position, and adaptively adjust the gating delay time and gating window width according to environmental changes and echo quality changes. The gating timing control module and the signal processing module form an inner loop feedback path based on echo signal characteristics to adjust the gating parameters in real time according to the photon arrival time histogram and the signal-to-noise ratio; the adaptive environment detection module and the gating timing control module form an outer loop feedback path based on environmental perception indicators to perform slow time-varying correction on the gating parameters, thereby realizing real-time detection of dual closed-loop dynamic gating in complex environments.

2. The quantum lidar dynamic gating real-time detection system according to claim 1, characterized in that, The laser emitting system includes a pulsed laser and an emitting optical path. The pulsed laser is used to generate the laser pulse, and the emitting optical path is arranged on the light-emitting side of the pulsed laser. The echo receiving system includes a receiving optical path and a single-photon avalanche diode array. The receiving optical path is disposed between the target region and the single-photon avalanche diode array. The single-photon avalanche diode array is used to respond to the dynamic gating signal and output the photon event data.

3. The quantum lidar dynamic gating real-time detection system according to claim 2, characterized in that, The single-photon avalanche diode array is a high-sensitivity single-photon detection module. The quantum efficiency of the single-photon avalanche diode array is greater than 65% and the dark count rate is less than 100 cps. It is used to record the photon arrival timestamp.

4. The quantum lidar dynamic gating real-time detection system according to claim 1, characterized in that, The adaptive environment detection module includes: an ambient light sensor for detecting background light intensity; an atmospheric scattering measurement device for measuring the atmospheric scattering coefficient; and an inertial measurement unit for providing the system's pitch angle, yaw angle, and roll angle attitude information.

5. The quantum lidar dynamic gating real-time detection system according to claim 1, characterized in that, The signal processing module constructs a photon arrival time histogram based on the time-correlated single-photon counting principle, calculates the flight time from the laser emission system to the echo reception system, and obtains the target distance information accordingly.

6. The quantum lidar dynamic gating real-time detection system according to claim 1, characterized in that, The gating timing control module includes a field-programmable gate array (FPGA), which embeds an adaptive time gating algorithm. The adaptive time gating algorithm is used to compare the time characteristics of the laser trigger signal output by the laser emitting system with the echo signal, and based on the environmental perception index and the echo main peak time domain position characteristics and signal-to-noise ratio information fed back by the signal processing module, it calculates and dynamically corrects the gating delay time and gating window width in real time, so that the center of the gating pulse is aligned with the main peak of the echo signal.

7. The quantum lidar dynamic gating real-time detection system according to claim 1, characterized in that, The gated timing control module is used to generate gated timing corresponding to multiple targets based on multiple local peak features in the photon arrival time histogram; and adaptively expands the gated window width when the time domain position feature of the echo main peak is detected to weaken or the signal-to-noise ratio is lower than a preset threshold during continuous detection cycles.

8. A signal processing method for a quantum lidar dynamic gating real-time detection system, characterized in that, Based on the system implementation according to any one of claims 1 to 7, the method includes: The laser emission system generates high-repetition-frequency and narrow-pulse-width laser pulses and irradiates the target area, while simultaneously outputting a laser trigger signal synchronized with the laser pulse emission. The laser pulses are reflected by the target area to form an echo signal. The adaptive environment detection module collects ambient light intensity, atmospheric scattering coefficient and system attitude angle information, and generates environmental perception indicators. The gating timing control module receives the laser trigger signal and, based on the environmental perception indicators and the echo main peak time domain position characteristics and signal-to-noise ratio information fed back by the signal processing module in the previous detection cycle, jointly calculates the gating delay time and gating window width of the current detection cycle, generates a dynamic gating signal, and sends it to the echo receiving system. The echo receiving system receives echo signals from the target area under the control of the dynamic gating signal, and performs single-photon detection on the echo signals to generate photon event data. The signal processing module performs time statistics processing on the photon event data, constructs a photon arrival time histogram, and extracts target distance, signal-to-noise ratio, and echo main peak time domain location features. The gating timing control module updates the gating delay time and gating window width for the next detection cycle based on the echo peak time domain location characteristics, signal-to-noise ratio, and environmental perception indicators obtained in the current detection cycle, so as to form a dual closed-loop optimization based on detection result feedback and environmental parameter feedback.

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