阅读说明：本技术 基于航迹信息场的无源跟踪方法 (Passive tracking method based on track information field ) 是由 王杰贵 唐希雯 刘方正 韩振中 孔辉 相飞华 吴世龙 武东明 马晓静 于 2020-11-30 设计创作，主要内容包括：本发明公开了一种基于航迹信息场的无源跟踪方法,提出了目标航迹信息场的概念,建立了目标航迹信息场模型,在此基础上,提出了基于信息融合获取目标航迹信息场,并基于航迹信息场实现目标拟合跟踪的方法。该方法步骤如下：量测数据获取,利用无源侦察设备,获取目标的量测数据；基于量测数据的目标状态估计,利用目标状态参数,对目标状态进行估计；点迹形成；基于信息融合的航迹信息场获取,采用灰关联信息融合的方法进行点迹凝聚,获取目标航迹信息场；基于航迹信息场,利用微分多项式模型进行航迹拟合,进而实现目标跟踪；解决了现有目标跟踪方法需要进行数据关联和跟踪滤波的问题。(The invention discloses a passive tracking method based on a track information field, which provides a concept of a target track information field, establishes a model of the target track information field, and provides a method for acquiring the target track information field based on information fusion and realizing target fitting tracking based on the track information field. The method comprises the following steps: measurement data acquisition, namely acquiring measurement data of a target by using passive reconnaissance equipment; estimating a target state by using a target state parameter based on the target state estimation of the measured data; forming a dot trace; acquiring a track information field based on information fusion, and performing point track aggregation by adopting a gray correlation information fusion method to acquire a target track information field; based on the track information field, carrying out track fitting by utilizing a differential polynomial model so as to realize target tracking; the method solves the problems that the existing target tracking method needs data correlation and tracking filtering.)

1. The passive tracking method based on the flight path information field is characterized by comprising the following steps of:

s1: acquiring target measurement data by using passive reconnaissance equipment;

s2: estimating the target state by using the target state parameters;

s3: forming trace point data of the target based on the result of the target state estimation;

s4: performing trace point condensation by a grey correlation information fusion method to obtain a target track information field;

s5: and based on the fitting tracking of the track information field, carrying out track fitting by using a differential polynomial model so as to realize target tracking.

2. The passive tracking method based on the track information field according to claim 1, wherein the target measurement data comprises target state parameters and radiation source characteristic parameters; the target state parameters comprise a signal arrival angle DOA, a signal arrival time TOA and a Doppler frequency; radiation source characteristic parameters include operating frequency RF, pulse width PW, pulse repetition period PRI, and intra-pulse characteristic IPC.

3. The passive tracking method based on the track information field according to claim 1, wherein the estimating of the target state specifically comprises: and based on the target state parameters, estimating the target state according to an observation equation to obtain the position information of the target.

4. The passive tracking method based on the flight path information field according to claim 1, wherein the specific steps of performing point-trace condensation by a gray correlation information fusion method are as follows:

s41: is provided withRepresents a set of valid measurements identified at time k within the tracking gate, wherein m (k) represents the number of valid measurements identified at time k,represents the cumulative valid metric set, θ, up to time k_i(k) Denotes z_i(k) Is an event from the correct measurement of the tracked target, θ₀(k) An event indicating that none of the measurements within the tracking gate are correct;

s42: by p_i(k)＝P(θ_i(k)|Z^k) To represent the information field probability density function, which means the probability that the ith measurement at time k is from the tracking target, i.e. the measurement z_i(k) Probability of correct measurement;

s43: marking the state parameters and the radiation source characteristic parameters of the target as target multi-characteristic data; selecting target multi-feature data as a reference sequence marked as X₀＝{X₀(j)|j＝1,2,…,5}；

S44: selecting m (k) effective observed target multi-features in the tracking gateData as comparison sequence, the ith comparison sequence is marked as X_i＝{X_i(j)|j＝1,2,…,5}，i＝1,2,…,m(k)；

S45: obtaining the correlation coefficient values of each comparison array and each reference array relative to each index through the similarity degree of the multi-feature data, and then, centralizing the correlation coefficients of each index of each comparison array on a numerical value through information fusion, wherein the numerical value is gray correlation;

s46: obtaining the gray correlation degree gamma (X) of the comparison sequence and the ith reference sequence through information fusion₀,X_i) Abbreviated as gamma_i；

S47: calculating an information field probability density function based on the grey correlation:

s48: and after the information field probability density function is obtained, point trace information fusion is carried out based on the information field probability density function, and point trace aggregation is realized.

Technical Field

The invention relates to the field of radio positioning, in particular to a passive tracking method based on a track information field.

Background

The target positioning and tracking problem is a basic problem in nature, plays a vital role in modern war, and can quickly and accurately position and track the target of an enemy, which has very important significance for effectively protecting the enemy and accurately fighting against enemies.

The passive positioning and tracking is to position the target by using the electromagnetic wave emitted by the target itself, and the most typical example is to position and track the radar radiation source. The current target tracking mainly adopts data association and tracking filtering technology, wherein the data association is used for determining the most reasonable measurement/track pairing, and the tracking filtering is used for estimating the track state of the target. The data association method mainly includes a "nearest neighbor" (NN) method and a "full neighbor" (AN) method, and a typical representative of the AN method is a Probabilistic Data Association (PDA) method. In the NN method, the observation closest to the target forecast measurement statistical distance is considered to originate from the target, and the PDA method considers that all valid observations may originate from the target, except that the probability of association of each valid observation with the target is different, which takes the weighted sum of the probabilities of all valid observations as the equivalent observation. The current tracking filtering is mainly based on Kalman Filtering (KF) and its extended algorithms, such as Extended Kalman (EKF), unscrupulous kalman algorithm (UKF), volumetric kalman algorithm (CKF), etc.

The target tracking method based on data association and tracking filtering has at least the following defects: 1) the NN method has poor anti-interference capability, and under the condition of large target density or large observation noise, the latest observation is not necessarily generated by the current target, and correlation errors are easy to generate; 2) the PDA method takes the weighted sum of all the probabilities of valid observations as an equivalent observation, which is actually a false target, causing tracking errors; 3) the Kalman filtering and the extended algorithm thereof have the divergence problem of the filtering algorithm due to the deviation of a mathematical model and a physical process, improper linearization or dimension reduction processing and the like.

In order to overcome the defects and improve the performance of target tracking, a passive tracking technology based on a flight path information field is provided. The method comprises the steps of firstly providing a concept of a target track information field, establishing a model of the target track information field, and on the basis, providing a method for obtaining the target track information field based on information fusion and realizing target fitting tracking based on the track information field. The technology does not need data association and tracking filtering, and the convergence performance of target tracking is improved.

Disclosure of Invention

The invention aims to provide a passive tracking method based on a track information field in order to solve the problems that the existing target tracking method needs data correlation and tracking filtering; the target track information field is obtained based on information fusion by establishing a target track information field model, and target fitting tracking is realized based on the track information field.

The purpose of the invention can be realized by the following technical scheme: the passive tracking method based on the flight path information field comprises the following steps:

s1: acquiring target measurement data by using passive reconnaissance equipment;

s2: estimating the target state by using the target state parameters;

s3: forming trace point data of the target based on the result of the target state estimation;

s4: performing trace point condensation by a grey correlation information fusion method to obtain a target track information field;

s5: and based on the fitting tracking of the track information field, carrying out track fitting by using a differential polynomial model so as to realize target tracking.

Preferably, the target measurement data comprises a target state parameter and a radiation source characteristic parameter; the target state parameters comprise a signal arrival angle DOA, a signal arrival time TOA and a Doppler frequency; radiation source characteristic parameters include operating frequency RF, pulse width PW, pulse repetition period PRI, and intra-pulse characteristic IPC.

Preferably, the estimating the target state specifically includes: and based on the target state parameters, estimating the target state according to an observation equation to obtain the position information of the target.

Preferably, the specific steps of performing trace point aggregation by a gray correlation information fusion method are as follows:

s41: is provided withRepresents a set of valid measurements identified at time k within the tracking gate, wherein m (k) represents the number of valid measurements identified at time k,represents the cumulative valid metric set, θ, up to time k_i(k) Denotes z_i(k) Is an event from the correct measurement of the tracked target, θ₀(k) An event indicating that none of the measurements within the tracking gate are correct;

s42: by p_i(k)＝P(θ_i(k)|Z^k) To represent the information field probability density function, which means the probability that the ith measurement at time k is from the tracking target, i.e. the measurement z_i(k) Probability of correct measurement;

s43: marking the state parameters and the radiation source characteristic parameters of the target as target multi-characteristic data; selecting target multi-feature data as a reference sequence marked as X₀＝{X₀(j)|j＝1,2,…,5}；

S44: selecting m (k) effective observed target multi-feature data in the tracking gate as a comparison sequence, and marking the ith comparison sequence as X_i＝{X_i(j)|j＝1,2,…,5}，i＝1,2,…,m(k)；

S45: obtaining the correlation coefficient values of each comparison array and each reference array relative to each index through the similarity degree of the multi-feature data, and then, centralizing the correlation coefficients of each index of each comparison array on a numerical value through information fusion, wherein the numerical value is gray correlation;

s46: obtaining the gray correlation degree gamma (X) of the comparison sequence and the ith reference sequence through information fusion₀,X_i) Abbreviated as gamma_i；

S47: calculating an information field probability density function based on the grey correlation:

s48: and after the information field probability density function is obtained, point trace information fusion is carried out based on the information field probability density function, and point trace aggregation is realized.

Compared with the prior art, the invention has the beneficial effects that:

1. the invention can effectively improve the convergence performance of target tracking, and solves the problems of long convergence time and even tracking divergence of the traditional tracking technology based on a filtering algorithm;

2. the passive tracking method based on the flight path information field avoids data association and tracking filtering in the traditional tracking method, and greatly improves the convergence performance of target tracking.

Drawings

In order to facilitate understanding for those skilled in the art, the present invention will be further described with reference to the accompanying drawings.

FIG. 1 is a flow chart of the passive tracking based on the track information field of the present invention;

FIG. 2 is a diagram of passive tracking error based on a filtering algorithm of the present invention;

FIG. 3 is a diagram of the result of the passive tracking simulation based on the track information field according to the present invention.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments, and it should be understood 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.

For a moving Target, all the points observed by the reconnaissance station on the Target contain certain radiation source position and motion track Information, and the Target point Information of multiple observations is accumulated to form a Target Tracking Information Field (TTIF).

1) Basic concept of target track information field

The position of the target can be seen as a random variable subject to a certain distribution in the position observation space. When the target track is tracked, in the case of a single target, when the single target is positioned without errors, the point track of the target is distributed on the real motion track of the target, and in the case of errors in the single positioning, the probability distribution of the point track of the target is determined by the distribution of the real motion track and the positioning errors of the target.

In fact, the problem of tracking the radiation source can be taken into account from an information point of view. Each track contains certain radiation source position and motion track information, and the track information contained in all the target tracks is accumulated to form a target track information field. In the position observation space, the distribution of the target motion trail can be represented by a target track information field function. The larger the field strength of the target track information field at a certain observation position is, the more possibility that the position is the target track of the radiation source is. All the point tracks have larger target track information field intensity at the real target track, and the maximum target track information field intensity at the real motion track of the target can be obtained after accumulation, so that the track of the radiation source target can be estimated according to the target track information field intensity.

2) Target track information field model

Assuming that P radiation source targets exist in the space simultaneously, the spatial position of the ith radiation source target at the k time is u_ik＝[x_i,k,y_i,k,z_i,k]^T(i-1, 2, …, P), in the case of single target location without error, the trace point distribution characteristics of the target can be represented by an accurate probability density function, and alsoThat is, the flight path information field function of the ith radiation source target at the kth time can be expressed as:

wherein, a_ikIs u ═ u_ikIs the reliability factor of the true position of the ith radiation source at the kth time, is a relative value, b_uTo normalize the coefficients, the function p is guaranteed_ikThe spatial region integral value of (u) is 1, and δ (·) is a dirac function.

According to the function of the target track information field under the ideal condition, the field intensity value of the target track information field at the real position of the target is the maximum and is an impact, and the field intensity value of the target track information field at other positions is zero, so that the track position of the target can be determined according to the field intensity value of the target track information field;

referring to fig. 1-3, the passive tracking method based on the track information field includes the following steps:

s1: measurement data acquisition, namely acquiring measurement data of a target by using passive reconnaissance equipment;

in a passive positioning system, target measurement data mainly comprises target state parameters and radiation source characteristic parameters, wherein the target state parameters refer to measurement data related to a target position state, such as a signal arrival angle DOA, a signal arrival time TOA, a Doppler frequency and the like, and the radiation source characteristic parameters comprise a working frequency RF, a pulse width PW, a pulse repetition period PRI, an intra-pulse characteristic IPC and the like;

s2: estimating a target state by using a target state parameter based on the target state estimation of the measured data;

estimating the state of the target according to an observation equation based on parameters such as a signal arrival angle, a signal arrival time and Doppler frequency to obtain the position information of the target;

s3: forming a trace point, and forming trace point data of the target based on the result of the target state estimation;

s4: performing trace point condensation by a grey correlation information fusion method to obtain a target track information field;

suppose thatRepresents a set of valid measurements identified at time k within the tracking gate, wherein m (k) represents the number of valid measurements identified at time k,represents the cumulative valid metric set, θ, up to time k_i(k) Denotes z_i(k) Is an event from the correct measurement of the tracked target, θ₀(k) An event indicating that none of the measurements within the tracking gate are correct;

for the information field probability density function p_i(k)＝P(θ_i(k)|Z^k) Means the probability that the ith measurement at time k is from the event of tracking the target, i.e. measurement z_i(k) Is the probability of correct measurement.

The calculation of the information field probability density function is a key issue. Under the condition of random noise interference or under the condition of multiple targets, in order to improve the accuracy of tracking the target track information field, the method calculates the probability density function of the information field by a gray correlation information fusion method according to state parameters (ST) and radiation source characteristic parameters (RF, PRI, PW and IPC) of the targets, which are collectively called target multi-characteristic data.

Selecting target multi-feature data (including ST, RF, PRI, PW and IPC) as reference sequence, and recording as X₀＝{X₀(j) 1,2, …,5 }. Selecting m (k) effective observed multi-feature data in the tracking gate as a comparison sequence, and marking the ith comparison sequence as X_i＝{X_i(j)|j＝1,2,…,5}，i＝1,2,…,m(k)。

According to the similarity of the multi-feature data, the correlation coefficient values of each comparison number series and the reference number series relative to each index can be obtained, and then the correlation coefficient set of each index of each comparison number series is reflected on a value through information fusion, and the value is gray correlation.

Through information fusion, the gray correlation degree gamma (X) of the comparison sequence and the ith reference sequence can be obtained₀,X_i) Abbreviated as gamma_i。

Calculating an information field probability density function based on the grey correlation:

after the information field probability density function is obtained, point track information fusion is carried out based on the information field probability density function, point track condensation is achieved, and a track information field is obtained;

s5: based on the fitting tracking of the track information field, carrying out track fitting by using a differential polynomial model so as to realize target tracking;

the traditional target tracking method based on data association and tracking filtering mainly adopts Kalman Filtering (KF) and its extended algorithms, such as Extended Kalman (EKF) and unscented Kalman algorithm (UKF). The tracking filter algorithms have divergence problems due to the deviation of a mathematical model and a physical process, improper linearization or dimension reduction processing and the like.

In a cartesian coordinate system, for an object moving in three-dimensional space, at time t, its coordinates with respect to the reference origin O are (xt, yt, zt). In the case of random disturbance not considered, the n-order differential polynomial motion model of the target is:

wherein (x0, y0, z0) represents the coordinates of the target at time t0,

the state vector of the target is taken as:

when random interference is considered, the target state equation based on the differential polynomial model is:

X(k+1)＝Φ(k)X(k)+W(k)

wherein the state transition matrix Φ (k) is:

the fitting tracking based on the flight path information field is that based on the result of the information fusion flight path information field, the flight path fitting is carried out by utilizing a differential polynomial motion model, and then the target tracking is realized;

example (b):

the experimental conditions are as follows: the observation station is positioned at the origin of coordinates, the target radiation source makes uniform linear motion, the initial position of the target is (100,200) km, the flight speed is (-100 ) m/s, the observation period is 1s, the observed quantities are DOA, TOA and Doppler frequency respectively, and the observation errors are 0.5 degrees, 10ns and 1Hz respectively.

In experiment 1, three filter-based algorithms (EKF, UKF, CKF) are respectively adopted for tracking, and the tracking error result is shown in fig. 2. As can be seen from fig. 2, the convergence time of the three filter tracking methods is relatively long.

Experiment 2, tracking is performed by adopting a passive tracking technology based on a flight path information field, and the tracking result is shown in fig. 3. As can be seen from fig. 3, the passive tracking technology based on the track information field performs tracking, so that the convergence performance of target tracking is improved;

when the system is used, the passive reconnaissance equipment is used for acquiring target measurement data; estimating the target state by using the target state parameters; forming trace point data of the target based on the result of the target state estimation; performing trace point condensation by a grey correlation information fusion method to obtain a target track information field; based on the fitting tracking of the track information field, carrying out track fitting by using a differential polynomial model so as to realize target tracking; the convergence performance of target tracking can be effectively improved, the problems of long convergence time and even tracking divergence of the traditional tracking technology based on a filtering algorithm are solved, the data association and tracking filtering in the traditional tracking method are avoided based on the passive tracking method of the flight path information field, and the convergence performance of target tracking is greatly improved.

The preferred embodiments of the invention disclosed above are intended to be illustrative only. The preferred embodiments are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best utilize the invention. The invention is limited only by the claims and their full scope and equivalents.