阅读说明：本技术 一种量子激光雷达的测距滤波跟踪方法及系统 (Range finding filtering tracking method and system for quantum laser radar ) 是由 王海伟 肖�琳 刘文豪 于 2021-08-11 设计创作，主要内容包括：本发明涉及量子激光雷达的测距滤波跟踪方法,依据探测信号合成二值化图像；对预定范围内的所有观测距离数据进行哈夫变换得到目标初始距离以及速度；确定跟踪的观测距离范围和时间范围；对指定范围的所有观测距离数据进行哈夫变换得到实时观测距离以及速度；依据实时观测距离及速度获得更新的观测距离范围,在更新的观测距离范围和时间范围内的所有观测距离进行哈夫变换得到更新的实时观测距离以及速度,重复执行直至跟踪结束后退出；还包括基于卡尔曼滤波的预测估计步骤,依据一当前观测时刻的观测距离估计值和实时速度估计下一观测时刻的观测距离估计值。能够对高速高动态目标进行具有广泛适用性的目标提取和跟踪探测。(The invention relates to a distance measurement filtering tracking method of a quantum laser radar, which synthesizes a binary image according to a detection signal; performing Hough transformation on all observation distance data in a preset range to obtain an initial distance and a speed of a target; determining a tracked observation distance range and a tracked time range; performing Hough transformation on all observation distance data in a specified range to obtain real-time observation distance and speed; obtaining an updated observation distance range according to the real-time observation distance and speed, performing Hough transform on all observation distances in the updated observation distance range and time range to obtain an updated real-time observation distance and speed, and repeating the operation until the tracking is finished; and the method also comprises a prediction estimation step based on Kalman filtering, and the estimation value of the observation distance at the next observation time is estimated according to the estimation value of the observation distance at the current observation time and the real-time speed. The target extraction and tracking detection with wide applicability can be carried out on the high-speed and high-dynamic target.)

1. A quantum laser radar ranging filtering tracking method is characterized by comprising the following steps:

step 1, a detector detects a target echo signal to obtain a detection signal, a target echo intensity and a noise echo intensity are obtained according to the detection signal, a target binary image is obtained according to the target echo intensity, a noise binary image is obtained according to the noise echo intensity, a composite binary image is obtained according to the target binary image and the noise binary image, and the composite binary image comprises each observation time and an observation distance corresponding to each observation time within an observation time range;

step 2, performing Hough transform on data of all observation distances in a preset observation time range in the synthesized binary image to obtain a parameter spatial distribution value, and obtaining a target initial distance and a target initial speed according to the parameter spatial distribution value;

step 3, determining an observation distance range and an observation time range of tracking according to the target initial distance and the target initial speed;

step 4, carrying out Hough transformation on the data of all the observation distances in the observation distance range and the observation time range to obtain a second parameter spatial distribution value, and obtaining a real-time observation distance and a real-time speed in the observation time range according to the second parameter spatial distribution value;

step 5, obtaining an updated observation distance range according to the real-time observation distance and the real-time speed, performing Hough transform on all observation distances in the updated observation distance range and an updated observation time range which is pushed backward for a preset time to obtain an updated parameter spatial distribution value, obtaining the real-time observation distance and the real-time speed in the updated observation time range according to the updated parameter spatial distribution value, and repeatedly executing the step 5 until the tracking is finished and the step is exited;

and in the process of executing the step 4 and the step 5, the method also comprises a prediction estimation step based on Kalman filtering, and the observation distance estimation value of the next observation time is estimated according to the observation distance estimation value of the current observation time and the real-time speed.

2. The quantum lidar ranging, filtering and tracking method according to claim 1, wherein the step 1 comprises:

step 11, calculating the target occurrence probability of each observation distance unit according to the target echo intensity, assigning values in the corresponding observation time and observation distance unit according to the target occurrence probability, and obtaining the target binary image related to the observation time and the corresponding observation distance;

step 12, calculating the noise detection probability of each observation distance unit according to the noise echo intensity, assigning values in the corresponding observation time and observation distance unit according to the noise detection probability, and obtaining the noise binarization image related to the observation time and the corresponding observation distance;

and step 13, performing logical AND operation on the target binary image and the noise binary image to obtain a composite binary image.

3. The quantum lidar ranging, filtering and tracking method according to claim 2, wherein the target echo intensity of each observation range unit in step 1 is obtained by the following formula:

Ns＝(p^＊Nt^＊Nr^＊(t^2)^＊Et^＊Ar^＊At^＊Nq^＊Nm)/(Al^＊pi^＊R^＊R^＊E)；

the target occurrence probability of each observation range bin is obtained by the following formula:

Ps＝1-exp(-Ns)；

the noise echo intensity of each observation range cell is obtained by the following formula:

Nn＝(p^＊e^＊i^＊Ar^＊Nr^＊t^2^＊s^2^＊Nq)/E

the noise detection probability of each observation range bin is obtained by the following formula:

Pn＝1-exp(-Nn/(1/tsd))；

wherein p is a target reflectivity, Nt is a laser emission system efficiency, Nr is a laser receiving system efficiency, t is an atmospheric transmittance, Et is a single pulse energy, Ar is a receiving effective area, At is a target projection area, Nq is a single photon detector quantum efficiency, Nm is an aiming probability, pi takes a value of 3.1415926, E is a single photon energy, E represents a background radiation illuminance, i represents a narrow band filter bandwidth, s represents a target field angle, Al represents a laser spot area At a target, R is a detection distance, Ns is a signal photoelectron intensity, Nn is a noise photon intensity, and tsd is an observation time unit corresponding to 1 s.

4. The quantum lidar ranging, filtering and tracking method according to claim 1, wherein the step 2 comprises the steps of:

step 21, taking the number of polar radius units as d as the number of observation distance units of the hough transform, taking the angle range from 0 to theta as an angle parameter, and calculating the angle search range according to the observation distance units, the observation time units, the maximum speed and the minimum speed, wherein the calculation formula is as follows:

θ∈[arctan((Δd/Δt)/Vmax)arctan((Δd/Δt)/Vmin)]，

wherein Vmin is the minimum speed of the target, Vmax is the maximum speed of the target, Δ d is the observation distance unit, Δ t is the observation time unit, and θ is the search angle;

step 22, carrying out Hough transform according to the selected polar radius and the selected angle parameter to obtain a first parameter spatial distribution value;

step 23, searching the first parameter spatial distribution value to obtain a peak point coordinate (ρ, θ), calculating a target initial distance and a target initial velocity corresponding to the peak point coordinate (ρ, θ) according to the following formula,

s0＝ρ/sinθ×Δa，

v0 ═ Δ d/Δ t/tan θ, where s0 is the target initial distance, v0 is the target initial velocity, and ρ is the polar radius.

5. The quantum lidar ranging, filtering and tracking method according to claim 1, wherein the step 3 comprises the steps of:

step 31, obtaining a first observation distance according to the target initial distance and the target initial speed, wherein a calculation formula is as follows: s1-s 0-v0 Δ t, wherein s0 is a target initial distance, v0 is a target initial speed, Δ t is an observation time unit, and s1 is the first observation distance;

step 32, obtaining an observation distance range according to the observation time range and the maximum speed of the target, wherein sg is [ s1-sf 1s 1+ sf2], where sg is the observation distance range, and sf1 and sf2 are distance offset;

step 33, calculating the number of observation distance units corresponding to the distance gate:

dg＝「round((s1-sf1)/Δd)round((s1+sf2)/Δd)]，

where round () represents the integer and Δ d is the observation distance unit.

6. The quantum lidar ranging, filtering and tracking method according to claim 5, wherein the step 4 comprises the steps of:

step 41, taking the number d of units with the polar radius rho as the number of observation distance units of the Haff transformation, and taking the angle range of 0-theta as an angle parameter;

step 42, carrying out Hough transform according to the selected polar radius and the selected angle parameter to obtain a second parameter spatial distribution value;

step 43, searching the peak point coordinates in the second parameter spatial distribution value, and calculating an angle search range according to the observation distance unit, the observation time unit, the maximum speed, and the minimum speed, wherein the calculation formula is as follows:

θ∈[arctan((Δd/Δt)/Vmtax)arctan((Δd/Δt)/Vmin)]，

in the formula, Δ d is the observation distance unit, Δ t is the observation time unit, θ is the search angle, Vmin is the minimum speed of the target, and Vmax is the maximum speed of the target;

step 44, searching the second parameter spatial distribution value to obtain a peak point coordinate (rho, theta), and calculating a real-time observation distance sn and a real-time observation speed vn which correspond to the peak point coordinate (rho, theta);

sn＝ρ/sinθ×Δd+s1-sf，vn＝Δd/Δt/tanθ，

wherein sn is the real-time observation distance, vn is the real-time observation speed, and sf is the distance offset.

7. The quantum lidar ranging, filtering and tracking method according to claim 1, wherein in the Kalman filtering based prediction and estimation step, the estimated observation distance and velocity are used to predict the observation distance estimation value,

sn1(k) is sn-vn x (k + n) x Δ t, where k is the observed time sequence number in the next observation period, n is the observation time offset value, and sn and vn are the observed distance estimation value and the speed estimation value estimated in the current observation time range and the observation distance range.

8. The quantum lidar ranging, filtering and tracking method according to claim 1, further comprising a target trajectory obtaining step of forming a target trajectory according to the real-time observation distance at each observation time, and forming a predicted trajectory according to the observation distance estimation value at each observation time.

9. A range filtering and tracking system for quantum laser radar comprises

A processing unit for performing the method of any one of claims 1 to 8;

the interface chip is connected with the processing unit and used for outputting data generated by the processing unit, wherein the data comprises a real-time observation distance and a real-time speed;

the memory chip is connected with the processing unit and used for storing the data generated by the processing unit; the data comprises photon event data;

the input end of the time measurement chip is connected with a laser emission main wave signal, a time signal and a photoelectric signal output by a single photodetector, the output end of the time measurement chip is connected with the processing unit, the time measurement chip outputs the occurrence time of a photon event, and the photon event comprises a target photon event and a noise photon event;

and the crystal oscillator unit is connected with the time measuring chip and the processing unit and is used for providing the time signal.

10. The quantum lidar ranging, filtering and tracking system according to claim 1, wherein the processing unit employs a chip based on an FPGA or DSP architecture, and the interface chip comprises a network interface chip and/or a serial interface chip.

Technical Field

The invention relates to the technical field of quantum laser radars, in particular to a method and a system for ranging, filtering and tracking of a quantum laser radar.

Background

The quantum laser radar realizes the ranging and imaging of a target, and the general quantum laser radar has the advantages of high repetition frequency of laser emission, extremely weak detection signals and sub-photon magnitude, and because photon noise introduced by dark counting and background of a detector is stronger than that of the traditional laser radar, target echo photon signals are often submerged in the background noise, so that the difficulty of signal extraction is caused. At present, a method of multiple accumulation and pseudo-random modulation is adopted, and then a target is extracted according to the distance correlation of the target, and the method is suitable for detection of static, low-speed or cooperative targets.

Compared with the traditional laser radar, the quantum laser radar has the advantages of long observation distance, small volume, low power consumption and the like, has great potential in future application, but is only suitable for detecting static, low-speed or cooperative targets at present. For a high-speed high-dynamic target, because parameters such as the distance, the speed, the acceleration and the motion vector of the high-speed high-dynamic target all change rapidly, the correlation between the front observation distance and the rear observation distance is weakened, the real-time extraction of the target distance cannot be realized through a traditional multiple accumulation method, and the situations of target tracking failure and the like are easy to occur.

Disclosure of Invention

In order to solve the technical problems, the invention provides a ranging filtering tracking method and system of a quantum laser radar. The technical scheme of the invention is as follows:

a quantum laser radar ranging filtering tracking method comprises the following steps:

step 1, a detector detects a target echo signal to obtain a detection signal, a target echo intensity and a noise echo intensity are obtained according to the detection signal, a target binary image is obtained according to the target echo intensity, a noise binary image is obtained according to the noise echo intensity, a composite binary image is obtained according to the target binary image and the noise binary image, and the composite binary image comprises each observation time and an observation distance corresponding to each observation time within an observation time range;

step 2, performing Hough transform on data of all observation distances in a preset observation time range in the synthesized binary image to obtain a parameter spatial distribution value, and obtaining a target initial distance and a target initial speed according to the parameter spatial distribution value;

step 3, determining an observation distance range and an observation time range of tracking according to the target initial distance and the target initial speed;

step 4, carrying out Hough transformation on the data of all the observation distances in the observation distance range and the observation time range to obtain a second parameter spatial distribution value, and obtaining a real-time observation distance and a real-time speed in the observation time range according to the second parameter spatial distribution value;

step 5, obtaining an updated observation distance range according to the real-time observation distance and the real-time speed, performing Hough transform on all observation distances in the updated observation distance range and an updated observation time range which is pushed backward for a preset time to obtain an updated parameter spatial distribution value, obtaining the real-time observation distance and the real-time speed in the updated observation time range according to the updated parameter spatial distribution value, and repeatedly executing the step 5 until the tracking is finished and the step is exited;

and in the process of executing the step 4 and the step 5, the method also comprises a prediction estimation step based on Kalman filtering, and the observation distance estimation value of the next observation time is estimated according to the observation distance estimation value of the current observation time and the real-time speed.

The invention discloses a quantum laser radar ranging filtering tracking method, which comprises the following steps of 1:

step 11, calculating the target occurrence probability of each observation distance unit according to the target echo intensity, assigning values in the corresponding observation time and observation distance unit according to the target occurrence probability, and obtaining the target binary image related to the observation time and the corresponding observation distance;

step 12, calculating the noise detection probability of each distance unit according to the noise echo intensity, assigning values in corresponding observation time and observation distance units according to the noise detection probability, and obtaining the noise binarization image related to the observation time and the corresponding observation distance;

and step 13, performing logical AND operation on the target binary image and the noise binary image to obtain a composite binary image.

The quantum laser radar ranging filtering tracking method of the invention comprises the step 1

The target echo intensity of each observation range unit is obtained by the following formula:

Ns＝(p*Nt*Nr*(t^2)*Et*Ar*At*Nq*Nm)/(Al*pi*R*R*E)；

the target occurrence probability of each observation range bin is obtained by the following formula:

Ps＝1-exp(-Ns)；

the noise echo intensity of each observation range cell is obtained by the following formula:

Nn＝(p*e*i*Ar*Nr*t^2*s^2*Nq)/E；

the noise detection probability of each observation range bin is obtained by the following formula:

Pn＝1-exp(-Nn/(1/tsd))；

wherein p is a target reflectivity, Nt is a laser emission system efficiency, Nr is a laser receiving system efficiency, t is an atmospheric transmittance, Et is a single pulse energy, Ar is a receiving effective area, At is a target projection area, Nq is a single photon detector quantum efficiency, Nm is an aiming probability, pi takes a value of 3.1415926, E is a single photon energy, E represents a background radiation illuminance, i represents a narrow band filter bandwidth, s represents a target field angle, Al represents a laser spot area At a target, R is a detection distance, Ns is a signal photoelectron intensity, Nn is a noise photon intensity, and tsd is an observation time unit corresponding to 1 s.

The quantum laser radar ranging filtering tracking method comprises the following steps of:

step 21, taking the number of polar radius units as d as the number of observation distance units of the hough transform, taking the angle range from 0 to theta as an angle parameter, and calculating the angle search range according to the observation distance units, the observation time units, the maximum speed and the minimum speed, wherein the calculation formula is as follows:

θ∈[arctan((Δd/Δt)/Vmax)arctan((Δd/Δt)/Vmin)]，

wherein Vmin is the minimum speed of the target, Vmax is the maximum speed of the target, Δ d is the observation distance unit, Δ t is the observation time unit, and θ is the search angle;

step 22, carrying out Hough transform according to the selected polar radius and the selected angle parameter to obtain a first parameter spatial distribution value;

step 23, searching the first parameter spatial distribution value to obtain a peak point coordinate (ρ, θ), calculating a target initial distance and a target initial velocity corresponding to the peak point coordinate (ρ, θ) according to the following formula,

s0＝ρ/sinθ×Δa，

v0 ═ Δ d/Δ t/tan θ, where s0 is the target initial distance, v0 is the target initial velocity, and ρ is the polar radius.

The quantum laser radar ranging filtering tracking method comprises the following steps of:

step 31, obtaining a first observation distance according to the target initial distance and the target initial speed, wherein a calculation formula is as follows: s1-s 0-v0 Δ t, wherein s0 is the target initial distance, v0 is the target initial speed, and s1 is the first observation distance;

step 32, obtaining an observation distance range according to the observation time range and the maximum speed of the target, wherein sg is [ s1-sf 1s 1+ sf2], where sg is the observation distance range, and sf1 and sf2 are distance offset;

step 33, calculating the number of observation distance units corresponding to the distance gate:

where round () represents rounding; and deltad is the observation distance unit.

The quantum laser radar ranging filtering tracking method comprises the following steps of:

step 41, taking the number d of units with the polar radius rho as the number of observation distance units of the Haff transformation, and taking the angle range of 0-theta as an angle parameter;

step 42, carrying out Hough transform according to the selected polar radius and the selected angle parameter to obtain a second parameter spatial distribution value;

step 43, searching the peak point coordinates in the second parameter spatial distribution value, and calculating an angle search range according to the observation distance unit, the observation time unit, the maximum speed, and the minimum speed, wherein the calculation formula is as follows:

θ∈[arctan((Δd/Δt)/vVmax)arctan((Δd/Δt)/Vmin)]，

in the formula, Δ d is the observation distance unit, Δ t is the observation time unit, θ is the search angle, Vmin is the minimum speed of the target, and Vmax is the maximum speed of the target;

step 44, searching the second parameter spatial distribution value to obtain a peak point coordinate (rho, theta), and calculating a real-time observation distance sn and a real-time observation speed vn which correspond to the peak point coordinate (rho, theta);

sn＝ρ/sinθ×Δd+s1-sf，vn＝Δd/Δt/tanθ，

wherein sn is the real-time observation distance, vn is the real-time observation speed, and sf is the distance offset.

In the prediction and estimation step based on Kalman filtering, the estimated observation distance and the estimated speed are adopted to predict the observation distance estimation value, sn1(k) is sn-vn x (k + n) x delta t, wherein k is the observation time sequence number in the next observation period, n is the observation time deviant, and sn and vn are the estimated observation distance estimation value and the estimated speed value in the current observation time range and the observation distance range.

The quantum laser radar ranging, filtering and tracking method further comprises a target track obtaining step, wherein a target track is formed according to the real-time observation distance at each observation moment, and a prediction track is formed according to the observation distance estimation value at each observation moment.

A range filtering and tracking system for quantum laser radar comprises,

a processing unit for performing the above method;

the interface chip is connected with the processing unit and used for outputting data generated by the processing unit, wherein the data comprises a real-time observation distance and a real-time speed;

the memory chip is connected with the processing unit and used for storing the data generated by the processing unit; the data comprises photon event data;

the input end of the time measurement chip is connected with a laser emission main wave signal, a time signal and a photoelectric signal output by a single photodetector, the output end of the time measurement chip is connected with the processing unit, the time measurement chip outputs the occurrence time of a photon event, and the photon event comprises a target photon event and a noise photon event;

and the crystal oscillator unit is connected with the time measuring chip and the processing unit and is used for providing the time signal.

According to the quantum laser radar ranging, filtering and tracking system, the processing unit adopts a chip based on an FPGA or DSP framework, and the interface chip comprises a network interface chip and/or a serial interface chip.

Has the advantages that: the ranging filtering tracking method of the quantum laser radar can extract and track and detect the target with wide applicability from the high-speed and high-dynamic target, and simultaneously ensures the instantaneity, the robustness and the reliability.

Drawings

FIG. 1 is a schematic flow diagram of the process of the present invention;

FIG. 2 is a block diagram of the system architecture of the present invention;

FIG. 3 is a schematic diagram of a noise binarization image of the present invention;

FIG. 4 is a schematic diagram of a target binary image according to the present invention;

FIG. 5 is a schematic diagram of a composite binarized image according to the present invention;

FIG. 6 is a schematic diagram of a target trajectory of the present invention;

FIG. 7 is a diagram of a full process simulation of a binary image containing noise according to the present invention;

FIG. 8 is a schematic diagram of range filtering during a capture phase based on an analog image;

FIG. 9 is a schematic diagram of a simulated image based predictive tracking stage range filtering;

FIG. 10 is a schematic diagram of an image implemented by the full-process range-finding filtering based on the simulated image according to the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

The invention is further described with reference to the following drawings and specific examples, which are not intended to be limiting.

Referring to fig. 1, a method for filtering and tracking a range of a quantum laser radar includes the following steps:

step 1, a detector detects a target echo signal to obtain a detection signal, a target echo intensity and a noise echo intensity are obtained according to the detection signal, a target binary image is obtained according to the target echo intensity, a noise binary image is obtained according to the noise echo intensity, a composite binary image is obtained according to the target binary image and the noise binary image, and the composite binary image comprises each observation time within an observation time range and an observation distance corresponding to each observation time;

step 2, carrying out Hough transformation on data of all observation distances in a preset observation time range in the synthesized binary image to obtain a parameter spatial distribution value, and obtaining a target initial distance and a target initial speed according to the parameter spatial distribution value;

step 3, determining an observation distance range and an observation time range of tracking according to the initial target distance and the initial target speed;

step 4, carrying out Hough transformation on data of all observation distances in the observation distance range and the observation time range to obtain a second parameter spatial distribution value, and obtaining a real-time observation distance and a real-time speed in the observation time range according to the second parameter spatial distribution value;

step 5, obtaining an updated observation distance range according to the real-time observation distance and the real-time speed, carrying out Hough transformation on all observation distances in the updated observation distance range and the updated observation time range which is pushed backward for a preset time to obtain an updated parameter spatial distribution value, obtaining the real-time observation distance and the real-time speed in the updated observation time range according to the updated parameter spatial distribution value, and repeatedly executing the step 5 until the tracking is finished and the step is exited;

and in the process of executing the step 4 and the step 5, a prediction estimation step based on Kalman filtering is further included, and the observation distance estimation value of the next observation time is estimated according to the observation distance estimation value of the current observation time and the real-time speed.

The invention converts the tracking distance measurement filtering problem of weak photon echo signals into a point cloud image processing problem of binary photon events, carries out Hough transform on a synthetic binary image formed by continuous multiple observation to obtain a parameter space distribution value, obtains a target initial distance and a target initial speed from the parameter space distribution value, demarcates an observation distance range and an observation time range of a tracking target according to target prior information, continuously accumulates and records photon counting events for a long time to obtain a real-time observation distance and a real-time speed in the observation time range, obtains an updated observation distance range and an updated observation time range on the basis, continuously repeats until the target is captured, simultaneously applies a Kalman filtering algorithm in a tracking stage to predict the target observation distance and speed, reduces the operation amount by updating the observation distance range and the time range in real time, and continuously iterating and calculating in sequence to continuously output the target distance and the target speed. The prediction tracking stage is based on target prediction information, the accumulated observation times are few, the data volume of the binary photon event image is small, the operand is small, the operation time is short, the data refreshing rate is high, and the method is suitable for high-speed and high-dynamic target tracking.

The invention discloses a quantum laser radar ranging filtering tracking method, which comprises the following steps of 1:

step 11, calculating the target occurrence probability of each observation distance unit according to the target echo intensity, assigning values in the corresponding observation time and observation distance unit according to the target occurrence probability, and obtaining a target binary image related to the observation time and the corresponding observation distance;

step 12, calculating the noise detection probability of each observation distance unit according to the noise echo intensity, assigning values in the corresponding observation time and observation distance unit according to the noise detection probability, and obtaining a noise binarization image related to the observation time and the corresponding observation distance;

and step 13, performing logical AND operation on the target binary image and the noise binary image to obtain a composite binary image.

In quantum laser radar detection, a sub-photon echo signal of a target is detected by a single photon detector, a photon event is converted into a photon event with a certain probability and is recorded by an acquisition system, an observation time and an echo arrival time are recorded by the target echo photon event, the echo arrival time can be converted into a target observation distance, random noise introduced by self dark counting and background of the detector is recorded as a noise photon event, and the random noise does not have correlation with the target and randomly appears.

When the quantum laser radar observes a target, the observation distance is quantized into n distance grids in dimension, the distance fineness is higher when the value of n is larger, when the target distance of a photon event falls into the distance grids, the value of the distance grids is marked as 1, and otherwise, the value of the distance grids is 0. The invention calculates the target occurrence probability of each observation distance unit according to the target echo intensity detected by the single photon detector, generates 0 or 1 assignment according to the probability, generates a target binary image with the observation time as a horizontal axis and the observation distance as a vertical axis in the corresponding observation time and observation distance unit, and similarly, as shown in figure 3, referring to figure 4, calculates the noise detection probability of each observation distance unit according to the noise echo intensity, and obtains the noise binary image with the observation time as the horizontal axis and the observation distance as the vertical axis according to the assignment of the noise detection probabilityAnd (3) image formation, performing and operation on the noise binary image and the target binary image to obtain a final composite binary image, as shown in fig. 5. For example, a value of 1 for the coordinates (M, N) means at M₀+(M-M₀) At the time of multiplied by delta t, the quantum laser radar observes a photon event, and the corresponding distance is N₀+(N-N₀)×Δd，(M₀，N₀) And delta t is the coordinate of the image origin, delta d is the observation time unit and delta d is the observation distance unit.

Aiming at a high-speed high-dynamic target, a target motion track in a binarized photon event image presents a straight line, a quadratic curve or a high-order curve, and the problem of target tracking ranging filtering is converted into a curve with correlation extracted from a binarized image formed by continuous multiple observation. Preferably, in step 1

The target echo intensity of each range bin is obtained by the following formula:

Ns＝(p*Nt*Nr*(t^2)*Et*Ar*At*Nq*Nm)/(Al*pi*R*R*E)；

the target occurrence probability of each observation range bin is obtained by the following formula:

Ps＝1-exp(-Ns)；

the noise echo intensity of each range bin is obtained by the following formula:

Nn＝(p*e*i*Ar*Nr*t^2*s^2*Nq)/E

the noise detection probability of each range bin is obtained by the following formula:

Pn＝1-exp(-Nn/(1/tsd))；

wherein p is a target reflectivity, Nt is a laser emission system efficiency, Nr is a laser receiving system efficiency, t is an atmospheric transmittance, Et is a single pulse energy, Ar is a receiving effective area, At is a target projection area, Nq is a single photon detector quantum efficiency, Nm is an aiming probability, pi takes a value of 3.1415926, E is a single photon energy, E represents a background radiation illuminance, i represents a narrow band filter bandwidth, s represents a target field angle, Al represents a laser spot area At a target, R is a detection distance, Ns is a signal photoelectron intensity, Nn is a noise photon intensity, and tsd is an observation time unit corresponding to 1 s.

The invention discloses a quantum laser radar ranging filtering tracking method, which comprises the following steps of 2:

step 21, taking the number of polar radius units as d as the number of observation distance units of Hough transform, taking the angle range of 0-theta as an angle parameter, and calculating the angle search range according to the observation distance units, the observation time units, the maximum speed and the minimum speed, wherein the calculation formula is as follows:

θ∈[arctan((Δd/Δt)/Vmax)arctan((Δd/Δt)/Vmin)]，

the Vmin is the minimum speed of the target, Vmax is the maximum speed of the target, delta d is an observation distance unit, delta t is an observation time unit, and theta is a search angle;

step 22, carrying out Hough transformation according to the selected polar radius and the selected angle parameter to obtain a first parameter spatial distribution value;

step 23, searching the first parameter spatial distribution value to obtain a peak point coordinate (ρ, θ), calculating a target initial distance and a target initial speed corresponding to the peak point coordinate (ρ, θ) according to the following formula,

s0＝ρ/sinθ×Δd，

v0 ═ Δ d/Δ t/tan θ, where s0 is the target initial distance, v0 is the target initial velocity, and ρ is the polar radius.

In the target capture stage, data of all observation distance units in a preset observation time range, which are accumulated at the beginning, are subjected to Hough transform according to the selected polar target and the angle parameter to obtain a first parameter space distribution value, and a peak point is searched in the first parameter space distribution value to obtain the initial distance and the initial speed of the target.

The invention discloses a quantum laser radar ranging filtering tracking method, which comprises the following steps of:

step 31, obtaining a first observation distance according to the target initial distance and the target initial speed, wherein the calculation formula is as follows: s1 is s0-v0 Δ t, wherein s0 is a target initial distance, v0 is a target initial speed, and s1 is a first observation distance;

step 32, obtaining a first observation distance range according to the observation time range and the maximum speed of the target, where sg is [ s1-sf 1s 1+ sf2], where sg is the observation distance range, and sf1 and sf2 are distance offsets;

step 33, calculating the number of observation distance units corresponding to the first observation distance range:

where round () represents rounding; and deltad is an observation distance unit. And calculating a first observation distance range or a distance gate of the tracking according to the initial distance and the initial speed of the target obtained in the capturing stage, and indicating that the target is searched in the distance range. And estimating the next observation distance range and observation time range according to the velocity value obtained by resolving in the corresponding observation time range and observation distance range at the last time.

The invention relates to a quantum laser radar ranging filtering tracking method, which comprises the following steps of step 4:

step 41, taking the unit number d of the polar radius rho as the number of observation distance units of the Haff transformation, and taking the angle range of 0-theta as an angle parameter;

step 42, carrying out Hough transformation according to the selected polar radius and the selected angle parameter to obtain a second parameter spatial distribution value;

step 43, searching the peak point coordinates in the second parameter spatial distribution value, and calculating the angle search range according to the observation distance unit, the observation time unit, the maximum speed and the minimum speed, wherein the calculation formula is as follows:

θ∈[arctan((Δd/Δt)/Vmax)arctan((Δd/Δt)/Vmin)]，

in the formula, Δ d is the observation distance unit, Δ t is the observation time unit, θ is the search angle, Vmin is the minimum speed of the target, and Vmax is the maximum speed of the target;

step 44, searching the second parameter spatial distribution value to obtain a peak point coordinate (rho, theta), and calculating a real-time observation distance sn and a real-time observation speed vn which correspond to the peak point coordinate (rho, theta);

sn＝ρ/sinθ×Δd+s1-sf，vn＝Δd/Δt/tanθ，

wherein sn is the real-time observation distance, vn is the real-time observation speed, and sf is the distance offset.

And (3) carrying out Hough transformation in the selected first observation distance range and observation time range, calculating the real-time observation distance and real-time observation speed of the target in the time period, then executing the step 5, obtaining the updated real-time observation distance and real-time speed according to the updated observation distance range and the updated observation time range which is pushed backward for a preset time, repeatedly executing the step 5 until quitting after the tracking is finished, and indicating the tracking is finished when the position or speed of the target object exceeds the tracking range or the target echo intensity is small and the target cannot be detected.

In the prediction and estimation step based on Kalman filtering, the estimated observation distance and the estimated speed are adopted to predict the observation distance estimation value, sn1(k) is sn-vn x (k + n) x delta t, wherein k is the observation time sequence number in the next observation period, n is the observation time deviant, and sn and vn are the estimated observation distance estimation value and the estimated speed value in the current observation time range and the observation distance range.

The quantum laser radar ranging filtering tracking method further comprises a target track obtaining step, wherein a target track is formed according to the real-time observation distance of each observation moment, and a prediction track is formed according to the observation distance estimation value of each observation moment. Fig. 6 is an extracted target trajectory graph, where '×' represents a tracked true distance value, a real-time observed distance value is obtained every second in the graph, and a line is a predicted value in the tracking stage.

Fig. 7 is a simulation diagram of the whole process of a binary image including noise, which is obtained by capturing the target by taking data of, for example, the previous 750 observations, and obtaining the initial distance and the initial velocity of the target at the current position of the target after capturing the target, and fig. 8 is a schematic diagram of the range-finding filtering based on the simulation image capturing stage. And opening a smaller observation distance range and observation time range for settlement according to the distance and speed values obtained in the capturing stage to obtain the real-time observation distance and real-time observation speed of the target, wherein the square in fig. 9 is the observation distance range (or called range gate) and observation time range (or called time gate) solved each time, and the origin part of fig. 9 is the distance and speed values obtained after each observation distance range and observation time range are solved. And predicting the target position in a subsequent period of time according to the real-time observation distance, the speed value and the motion model calculated by tracking. Fig. 10 is an image obtained by range-finding filtering based on the whole process of the simulation image, and the position of the triangle in fig. 10 is the target predicted position.

A range filtering and tracking system for quantum laser radar comprises,

a processing unit 20 for performing the above-described method;

the interface chip 30 is connected with the processing unit 20 and is used for outputting data g generated by the processing unit 20, wherein the data comprises a real-time observation distance and a real-time speed;

a memory chip 50 connected to the processing unit 20 for storing the data f generated by the processing unit 20; the data comprises photon event data;

the time measurement chip 10 comprises a time measurement chip 10, wherein the input end of the time measurement chip 10 is connected with a laser emission main wave signal b, a time signal and a photoelectric signal c output by a single photodetector, the output end of the time measurement chip 10 is connected with a processing unit 20, the time measurement chip 10 outputs the occurrence time d of a photon event, and the photon event comprises a target photon event and a noise photon event;

and the crystal oscillator unit 40 is connected with the time measuring chip 10 and the processing unit 20 and is used for providing a time signal e.

The processing unit 20 is also connected to a synchronization timing signal a as required.

In the quantum laser radar ranging, filtering and tracking system, the processing unit 20 adopts a chip based on an FPGA or DSP architecture, and the interface chip 30 comprises a network interface chip and/or a serial interface chip.

The invention provides a distance measurement filtering tracking method and a distance measurement filtering tracking system for a quantum laser radar, which can be widely suitable for target extraction and tracking detection of a high-speed high-dynamic target, solve the problems of instantaneity, robustness and reliability, and realize the system based on an embedded system, so that the application of the quantum laser radar to the fields of high-speed high-dynamic target detection and imaging is expanded, and the method and the system have great significance in application scenes such as foundation, airborne, spaceborne early warning radar, missile guidance and the like.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.