CN112147623A - Multi-region ranging method and system based on chaotic polarization radar - Google Patents

Abstract

The invention provides a multi-region ranging method and a multi-region ranging system based on a chaotic polarization radar, wherein the method comprises the following steps: the light beam emitted by the distributed feedback laser is divided by a polarization controller to generate a polarization component light beam; wherein the polarization component beam comprises an x-polarization component beam and a y-polarization component beam; the polarization component light beam is divided into a reference signal and a detection signal by an optical fiber polarization beam splitter; the reference signal and the detection signal sequentially pass through the optical fiber beam splitter and the signal processing module to respectively obtain a reference current signal and a detection current signal; generating a position vector of a first ranging target by the reference current signal and the detection current signal through a calculation module; the calculation module comprises: a correlation function calculating module and a target ranging calculating module. The method has the advantages of stability, high ranging resolution, strong anti-noise performance, low relative error required for measuring multi-region target position vectors in complex shapes, and great potential for intelligent precision machining and quality detection of targets in complex shapes.

Description

A multi-area ranging method and system based on chaotic polarization radar

technical field

The invention relates to the technical field of textile sorting, in particular to a multi-area ranging method and system based on chaotic polarization radar.

Background technique

With the rapid development of artificial intelligence, lidar is expected to achieve the following functions by sensing the surrounding environment: accurate target ranging, high-quality 3D imaging, target tracking and identification, automatic positioning and mapping.

Currently, most LiDAR ranging schemes use pulsed lasers and continuous wave lasers as light sources for better signal-to-noise ratio and measurement range. However, radar ranging based on pulsed lasers and continuous wave lasers has the disadvantages of low resolution, high interception probability, weak anti-interference ability and high cost.

Chaos Lidar (CLR)-based ranging generated by using nonlinear dynamics of semiconductors with optical feedback or optical injection has many advantages compared to ranging using pulsed and continuous-wave lasers, such as low probability of interception, Strong anti-interference ability and low cost. Furthermore, thanks to the wide bandwidth of optical chaos, it also has high resolution. Finally, chaotic radar is easy to generate and control due to its sensitivity to laser parameters.

However, first, the resolution of CLR ranging is largely limited by the bandwidth of chaotic lasers, and further improvement of ranging resolution requires ultrafast chaotic lasers with large modulation bandwidths. Secondly, in the current work of CLR ranging, the measured target plane is smooth and flat. CLR is usually used for fixed points in the target, and it is difficult to apply them to intelligent precision machining and quality detection of complex-shaped targets; CLR ranging The proposed scheme and method cannot completely detect the distance of different areas of the target, and are not suitable for accurate ranging of the entire area in the complex-shaped target. Finally, the CLR-based detection waveform is not modulated before target ranging, which reduces the resolution and accuracy of target ranging.

SUMMARY OF THE INVENTION

The present invention provides a multi-area ranging method and system based on chaotic polarization radar. By using two chaotic polarization waveforms modulated by random noise, accurate ranging of multiple areas of two complex-shaped targets is realized.

An embodiment of the present invention provides a multi-area ranging method based on chaotic polarization radar, including:

The beam emitted by the distributed feedback laser is divided by a polarization controller to generate a polarization component beam; wherein the polarization component beam includes an x-polarization component beam and a y-polarization component beam;

The polarization component beam is divided into a reference signal and a detection signal by a fiber polarization beam splitter;

The reference signal and the detection signal pass through the optical fiber beam splitter and the signal processing module in sequence, respectively, to obtain the reference current signal and the detection current signal;

The reference current signal and the detection current signal pass through a calculation module to generate a position vector of the first ranging target; the calculation module includes: a correlation function calculation module and a target range calculation module.

Further, the reference signal and the detection signal pass through the fiber beam splitter and the signal processing module in turn to obtain the reference current signal and the detection current signal, including:

The detection signal is divided into at least one bundle of chaotic radar detection waveforms by the first fiber beam splitter;

The chaotic radar detection waveform obtains an incident photocurrent signal through a signal processing module; wherein, the signal processing module includes: a first noise modulator, a first signal converter, a signal amplifier and a signal transmitter;

The incident photocurrent signal is emitted to the first ranging target, and an outgoing photocurrent signal is obtained through an optical reaction; wherein, the optical reaction includes: reflection and/or scattering;

The outgoing photocurrent signal sequentially passes through the signal receiver and the signal amplifier to obtain the detection current signal.

Further, the reference signal and the detection signal respectively pass through the optical fiber beam splitter and the signal processing module in turn to obtain the reference current signal and the detection current signal, and also include:

The reference signal is divided into at least one bundle of chaotic radar reference waveforms by the second fiber beam splitter;

The chaotic radar reference waveform is passed through a signal processing module to obtain a reference current signal; the signal processing module includes: a second noise modulator and a second signal converter.

Further, generating the position vector of the first ranging target by the reference current signal and the detection current signal calculation module includes:

Calculate the signal correlation of the reference current signal and the detection current signal through the correlation function calculation module;

The position vector of the first ranging target is generated through the target ranging calculation module and the signal correlation.

Further, the beam emitted by the distributed feedback laser is divided by a polarization controller to generate a polarization component beam, including:

The beam emitted by the distributed feedback laser generates a beam of unidirectional propagation through an optical isolator;

The unidirectionally propagating beams are split by a polarization controller to generate polarized component beams.

An embodiment of the present invention provides a multi-area ranging system based on chaotic polarization radar, including:

a polarization controller splitting module for splitting the beam emitted by the distributed feedback laser by the polarization controller to generate a polarization component beam; wherein the polarization component beam includes an x-polarization component beam and a y-polarization component beam;

an optical fiber polarization beam splitter splitting module, which is used for the polarization component beam to be divided into a reference signal and a detection signal by the optical fiber polarization beam splitter;

a reference current signal and a detection current signal acquisition module, used for the reference signal and the detection signal to pass through the optical fiber beam splitter and the signal processing module in sequence, respectively, to obtain the reference current signal and the detection current signal;

The position vector calculation module is used for the reference current signal and the detection current signal to pass through the calculation module to generate the position vector of the first ranging target; the calculation module includes: a correlation function calculation module and a target ranging calculation module.

Further, the reference current signal and detection current signal acquisition module includes: a detection current signal acquisition sub-module for the following steps:

The detection signal is divided into at least one bundle of chaotic radar detection waveforms by the first fiber beam splitter;

The chaotic radar detection waveform obtains an incident photocurrent signal through a signal processing module; wherein, the signal processing module includes: a first noise modulator, a first signal converter, a signal amplifier and a signal transmitter;

The incident photocurrent signal is emitted to the first ranging target, and an outgoing photocurrent signal is obtained through an optical reaction; wherein, the optical reaction includes: reflection and/or scattering;

The outgoing photocurrent signal sequentially passes through the signal receiver and the signal amplifier to obtain the detection current signal.

Further, the reference current signal and detection current signal acquisition module further includes: a reference current signal acquisition sub-module for the following steps:

The reference signal is divided into at least one bundle of chaotic radar reference waveforms by the second fiber beam splitter;

The chaotic radar reference waveform is passed through a signal processing module to obtain a reference current signal; the signal processing module includes: a second noise modulator and a second signal converter.

Further, the position vector calculation module is also used for:

Calculate the signal correlation of the reference current signal and the detection current signal through the correlation function calculation module;

The position vector of the first ranging target is generated through the target ranging calculation module and the signal correlation.

Further, the polarization controller segmentation module is also used for:

The beam emitted by the distributed feedback laser generates a beam of unidirectional propagation through an optical isolator;

The unidirectionally propagating beams are split by a polarization controller to generate polarized component beams.

Compared with the prior art, the beneficial effects of the embodiments of the present invention are:

An embodiment of the present invention provides a multi-area ranging method based on chaotic polarization radar, including: dividing a beam emitted by a distributed feedback laser by a polarization controller to generate a polarization component beam; wherein the polarization component beam includes x The polarization component beam and the y-polarization component beam; the polarization component beam is divided into a reference signal and a detection signal by the optical fiber polarization beam splitter; the reference signal and the detection signal pass through the optical fiber beam splitter and the signal processing module in turn to obtain the reference current respectively. signal and detection current signal; the reference current signal and the detection current signal pass through the calculation module to generate the position vector of the first ranging target; the calculation module includes: a correlation function calculation module and a target ranging calculation module. The invention has stable and high ranging resolution, strong anti-noise performance and low relative error required for measuring multi-region target position vectors in complex shapes, and has great potential for intelligent precision machining and complex shape target quality detection .

Description of drawings

In order to illustrate the technical solutions of the present invention more clearly, the following will briefly introduce the accompanying drawings used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention, which are common in the art. As far as technical personnel are concerned, other drawings can also be obtained based on these drawings without any creative effort.

1 is a flowchart of a multi-region ranging method based on chaotic polarization radar provided by an embodiment of the present invention;

2 is a flowchart of a multi-region ranging method based on chaotic polarization radar provided by another embodiment of the present invention;

Fig. 3 is the schematic diagram that the present invention realizes accurate ranging to multiple areas of two complex-shaped targets;

Fig. 4 is the geometric diagram of the arbitrary small area ranging of the complex shape target of the present invention;

Fig. 5 is the time trajectory diagram of the light beam of the present invention after noise modulation;

Fig. 6 is the function graph of the beam correlation of the present invention;

Fig. 7 is the function image of the light beam time and space correlation of the present invention;

8 is a geometric diagram of ranging of 10 small areas of a complex shape target of the present invention;

Fig. 9 is the function image of the time and space correlation of the received signal of the present invention;

Fig. 10 is the function image of the variation of the ranging resolution of the present invention with the noise intensity β;

11 is a device diagram of a multi-area ranging system based on chaotic polarization radar provided by an embodiment of the present invention;

FIG. 12 is a device diagram of a multi-area ranging system based on chaotic polarization radar according to another embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

It should be understood that the step numbers used in the text are only for the convenience of description, and are not intended to limit the order in which the steps are performed.

It should be understood that the terms used in the present specification are only for the purpose of describing particular embodiments and are not intended to limit the present invention. As used in this specification and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural unless the context clearly dictates otherwise.

The terms "comprising" and "comprising" indicate the presence of the described features, integers, steps, operations, elements and/or components, but do not exclude one or more other features, integers, steps, operations, elements, components and/or the existence or addition of its collection.

The term "and/or" refers to and including any and all possible combinations of one or more of the associated listed items.

first.

Based on optical injection into optically pumped spin VCSELs, we propose a new scheme for precise ranging of multiple regions in two complex-shaped targets by modulating two chaotic polarization radars with random noise. Here, the two modulated chaotic polarization radars have the excellent characteristics of space-time uncorrelated, femtosecond-level dynamics. Using these features, the reflected multiple beams of chaotic polarization detection waveforms with delayed signals and the corresponding reference waveforms can be correlated to calculate to achieve accurate ranging of the position vectors of multiple areas of two complex-shaped targets. . Further research shows that the ranging of multi-region small targets has a very low relative error, with an error of less than 0.23%. Their range resolution is stable at 0.2mm, and they have excellent noise immunity. The precise ranging of multi-region small targets by optical injection of optically pumped spin VCSELs provides a good prospect for potential applications in intelligent precision machining and quality inspection of complex-shaped targets.

Referring to FIG. 1, an embodiment of the present invention provides a multi-area ranging method based on chaotic polarization radar, including:

S10, the beam emitted by the distributed feedback laser is divided by a polarization controller to generate a polarization component beam; wherein, the polarization component beam includes an x-polarization component beam and a y-polarization component beam.

S20, the polarization component beam is divided into a reference signal and a detection signal by a fiber polarization beam splitter.

S30 , the reference signal and the detection signal pass through the fiber beam splitter and the signal processing module in sequence, respectively, to obtain the reference current signal and the detection current signal.

S40. The reference current signal and the detection current signal are passed through a calculation module to generate a position vector of the first ranging target; the calculation module includes: a correlation function calculation module and a target ranging calculation module.

Referring to FIG. 2, in a specific embodiment, in S30, the reference signal and the detection signal pass through the fiber beam splitter and the signal processing module in sequence, respectively, to obtain the reference current signal and the detection current signal, including:

S311. The detection signal is divided into at least one bundle of chaotic radar detection waveforms by the first fiber beam splitter.

S312, the chaotic radar detection waveform is passed through a signal processing module to obtain an incident photocurrent signal; wherein, the signal processing module includes: a first noise modulator, a first signal converter, a signal amplifier and a signal transmitter.

S313. The incident photocurrent signal is transmitted to the first ranging target, and an outgoing photocurrent signal is obtained through an optical reaction; wherein, the optical reaction includes reflection and/or scattering.

S314 , the outgoing photocurrent signal sequentially passes through the signal receiver and the signal amplifier to obtain a detection current signal.

Referring to FIG. 2, in a specific embodiment, in S30, the reference signal and the detection signal pass through the fiber beam splitter and the signal processing module in sequence, respectively, to obtain the reference current signal and the detection current signal, including:

S321. The reference signal is divided into at least one bundle of chaotic radar reference waveforms by the second fiber beam splitter.

S322, the chaotic radar reference waveform is passed through a signal processing module to obtain a reference current signal; the signal processing module includes: a second noise modulator and a second signal converter.

Referring to FIG. 2, in a specific embodiment, in S40, the reference current signal and the detection current signal calculation module generate a position vector of the first ranging target, including:

S41. Calculate the signal correlation between the reference current signal and the detection current signal through a correlation function calculation module.

S42. Generate a position vector of the first ranging target through the target ranging calculation module and the signal correlation.

Referring to FIG. 2, in a specific embodiment, in S10, the beam emitted by the distributed feedback laser is divided by a polarization controller to generate a polarization component beam, including:

S11. The beam emitted by the distributed feedback laser generates a beam of unidirectional propagation through an optical isolator.

S12, the unidirectionally propagating light beam is divided by a polarization controller to generate a polarization component light beam.

Referring to FIG. 3 , in a specific embodiment, two chaotic polarization waveforms are used in an optically injected optically pumped spin VCSEL to perform precise ranging on multiple regions of two complex-shaped targets. Among them, the DFB as an external light source is a distributed feedback laser. Optical isolators (OIs) with subscripts 1-2 are used to ensure unidirectional propagation of light waves. A neutral density filter (NDF) is used to control the intensity of the injected light field from the DFB. To ensure parallel injection of the polarized light of the DFB into the x-polarization component (PC) and y-PC of the optically pumped spin VCSEL, the polarized light output from the DFB needs to be split and adjusted to x by a polarization control optical path (PCOC). -PC and y-PC. In PCOC, the switching between x-PC and y-PC is achieved by some passive devices, such as fiber polarizer (FP), fiber polarization controller (FPCO), fiber depolarizer (FD) and fiber polarizer Coupler (FPC). Target 1 (T1) and target T2 are complex shape targets that are measured. PD is a photodetector. AM is an amplitude modulator. EA is an electric amplifier. TA and RA are the transmit and receive antennas, respectively. A fiber polarization beam splitter (FPBS) splits the chaotic light wave generated by injecting light into an optically pumped spin VCSEL into two PCs, defined as x-polarization chaotic lidar (XP-CLR) and y-polarization chaotic lidar (YP-CLR), respectively. ). The XP-CLR is further split into two light waves by a 1×1 Fiber Beam Splitter 1 (FBS1). One of them is used as a reference signal (RS) and the other is used as a sounding signal (PS). For ease of discussion, they are named XP-CLR-RS and XP-CLR-PS, respectively. Meanwhile, FBS2 further splits YP-CLR into two beams, one of which is used as RS and the other as PS. They are named YP-CLR-RS and YP-CLR-PS, respectively.

For the ranging of complex-shaped target T ₁ , XP-CLR-PS is divided into N beams of chaotic radar detection waveforms by 1×N FBS ₁ , and random noise modulation is performed by using AMs with subscripts 11-1N in sequence. These modulated probe waveforms are converted into N beams of probe current signals by PDs with subscripts 11-1N, and then amplified by EAs with subscripts 11-1N in turn. These amplified current signals are emitted to multiple regions of T1 through TAs subscripted _11-1N . After being reflected or scattered by multiple areas of T ₁ , they first have time-delay information, which are then received by RA ₁ and amplified by EA ₂ . On the other hand, XP-CLR-RS is divided into N beams of reference waveforms by 1×N FBS ₂ , which are subjected to random noise modulation by using AMs with subscripts 21-2N in order. These modulated reference waveforms are converted into N beam reference current signals by PDs with subscripts 21-2N in sequence. The correlation between the probe current signal and its corresponding reference current signal can be calculated by using a correlation function calculation module (CFCM). By observing the temporal position of the maximum expected value of the correlation, the position vectors _of the multiple regions of T1 can be further calculated using the Target Ranging Calculation Module (TRCM). Similarly, the position vectors of multiple regions of T ₂ can be obtained through TRCM.

For spin VCSELs, the left-handed and right-handed circularly polarized components of the light field can be reformulated from the orthogonal linear components as:

where E ₊ and E _- are the complex amplitudes of the left and right circularly polarized components, respectively, and _{Ex and E y are} the complex amplitudes of the two orthogonal linear components x-PC and y-PC, respectively. From Equation (1), the four coupling rate equations for optical injection into optically pumped spin VCSELs can be as follows:

Δω是DFB的中心频率和自旋VCSEL的参考频率之间的频率失谐。Among them, the subscripts x and y represent x-PC and y-PC, respectively. The circularly polarized field components are coupled through crystal birefringence, characterized by a velocity _γp and _a dichroism γa. The normalized carrier variables M and n of equations (2)-(5) are defined as M=(n ₊ +n ₋ )/2 and n=(n ₊ −n ₋ )/2, where n ₊ and n _- are the corresponding normalized densities of spin-down and spin-up electrons, respectively. k is the cavity decay rate and a is the linewidth gain factor. γ is the electron density decay rate. _γs is the spin relaxation rate. η is the total normalized pump power. P is the pump polarization ellipticity. k _xinj and k _yinj are the external injection intensities of x-PC and y-PC, respectively; β is the spontaneous scattering coefficient, also known as the noise intensity. Both ξ ₁ and ξ ₂ are independent white Gaussian noise with mean 0 and variance 1, where

Δω is the frequency detuning between the center frequency of the DFB and the reference frequency of the spinning VCSEL.

As shown in _Fig . ₄ , by using N beams of chaotic polarization radar detection waves simultaneously, any small area in T1 or T2 can be detected. After being reflected or scattered at the target, N-beam chaotic polarization radar detection waveforms with different delays are simultaneously received by the RA. In this case, according to the correlation theory, in order to easily detect the position vector of each small area, N-beam XP-CLR-PSs and N-beam YP-CLR-PSs need to satisfy temporally orthogonal uncorrelated and spatially orthogonal irrelevant. To satisfy these conditions, N beams of XP-CLR-PSs and N beams of YP-CLR-PSs are modulated with random noise, namely:

Similarly, N beams of XP-CLR-RSs and N beams of YP-CLR-RSs are modulated with random noise, which is expressed as:

和

分别为第j束XP-CLR-RSs和第j 束YP-CLR-RSs的复振幅。同理，

和

分别为第j束XP-CLR-PSs 和j束YP-CLR-PSs的复振幅。ζ是随机噪声。通过公式(6)-(9)， N束XP-CLR-PSs或N束YP-CLR-PSs彼此正交，在空间中用互相关可以表示为：Among them, the subscripts 1 and 2 represent PS and RS, respectively,

and

are the complex amplitudes of the jth bundle of XP-CLR-RSs and the jth bundle of YP-CLR-RSs, respectively. Similarly,

and

are the complex amplitudes of the jth bundle of XP-CLR-PSs and the jth bundle of YP-CLR-PSs, respectively. ζ is random noise. By formulas (6)-(9), N bundles of XP-CLR-PSs or N bundles of YP-CLR-PSs are orthogonal to each other, and can be expressed as:

and

Moreover, the j-th bundle in XP-CLR-PSs or the j-th bundle in YP-CLR-PSs is uncorrelated at different times, which is expressed by temporal autocorrelation as:

Since XP-CLR-RS and YP-CLR-RS are replica samples of XP-CLR-PS and YP-CLR-PS, respectively, the jth beam of XP-CLR-PS and its corresponding reference signals are mutually orthogonal of. Similarly, the jth beam of YP-CLR-PS and its corresponding reference signal can also achieve mutual orthogonality. They are expressed in space with cross-correlation as:

The cross-correlation in time between the jth beam of XP-CLR-PS and its corresponding reference signal and the cross-correlation between the jth beam of YP-CLR-PS and its corresponding reference signal in time are expressed as:

From equations (10)-(17), we can obtain the correlation functions of N-beam XP-CLR-PSs and N-beam YP-CLR-PSs in time and space, respectively, as follows:

The correlation functions of N bundles of XP-CLR-PSs and their corresponding reference signals and N bundles of YP-CLR-PSs and their corresponding reference signals can be expressed as:

As shown in Fig. 4, we used the modulated N-beam XP-CLR-PSs and N-beam YP-CLR-PSs to detect the target point (A) in a small area of T ₁ (T ₂ ) by RA ₁ (RA 1 (RA ) ₂ ) Receive the reflected or scattered signal. Therefore, the received signals of RA ₁ and RA ₂ can be written as

where τ _1,j and τ _2,j are the time delays from TA _1j to RA ₁ and from TA _2j to RA ₂ , respectively. Therefore, according to formulas (20)-(22), the cross-correlation function of the received signal from RA ₁ and the jth beam of XP-CLR-RS can be obtained as

And get the cross-correlation function of the received signal from RA ₁ and the jth beam YP-CLR-RS as

where T _int is the effective correlation time. The time delays τ _1,j and τ _2,j can be estimated as the values corresponding to the maximum positions, respectively, expressed as follows

是期望值。如图4所示，将A点的实际位置矢量设为 r_A，将要测量的第j束XP-CLR-PS或第j束YP-CLR-PS的其位置矢量设为r_Aj。发送天线TA_1j和TA_2j的位置矢量分别被设置为r_1j和r_2j。接收天线RA₁和RA₂的位置矢量设置为r_r1和r_r2。根据A点的几何关系，我们得到in,

is the expected value. As shown in FIG. 4 , let the actual position vector of point A be r _A , and let the position vector of the jth beam XP-CLR-PS or the jth beam YP-CLR-PS to be measured be r _Aj . The position vectors of the transmit antennas TA _1j and TA _2j are set to r _1j and r _2j , respectively. The position vectors of the receive antennas RA ₁ and RA ₂ are set to r _r1 and r _r2 . According to the geometric relationship of point A, we get

个几乎相等方程来解得A 点的位置矢量。我们将其平均值作为A点的精确位置向量，表示为From equation (26), we can solve for

A nearly equal equation to solve the position vector of point A. We take its average as the exact position vector of point A, denoted as

Table 1. Parameter values for the system in the calculation

和

由随机噪声调制后的时间轨迹，如图5所示。图中，

和

分别是第一束XP-CLR-PS和第一束YP-CLR-PS。

和

分别是第一束XP-CLR-RS和第一束YP-CLR-RS。从图5中可以看到，

和

的时间轨迹都呈现出混沌状态和飞秒级的快速动态特征，表明XP-CLR-PS，YP-CLR-PS，XP-CLR-RS和 YP-CLR-RS呈现出具有快速动态特征的混沌时间轨迹。这些来自 XP-CLR-PS或YP-CLR-PS的调制混沌雷达元均满足时间和空间上的不相关性(请参见等式(10)-(13))。为了理解它们的不相关性，我们以第5束XP-CLR-PS和第5束YP-CLR-PS为例来计算它们在不同时间的自相关(T_Px和T_Py)以及在空间上的互相关(R_Px和R_Py)，如图6所示。The parameter values used for the following calculations are given in Table 1. By formulas (6)-(9), we calculate

and

The time trace modulated by random noise is shown in Figure 5. In the figure,

and

They are the first beam of XP-CLR-PS and the first beam of YP-CLR-PS.

and

They are the first bundle of XP-CLR-RS and the first bundle of YP-CLR-RS, respectively. As can be seen from Figure 5,

and

The time trajectories of all present chaotic state and femtosecond-level fast dynamic characteristics, indicating that XP-CLR-PS, YP-CLR-PS, XP-CLR-RS and YP-CLR-RS exhibit chaotic time with fast dynamic characteristics trajectory. These modulated chaotic radar elements from XP-CLR-PS or YP-CLR-PS satisfy both temporal and spatial uncorrelation (see equations (10)-(13)). To understand their uncorrelatedness, we take the fifth beam XP-CLR-PS and the fifth beam YP-CLR-PS as examples to calculate their autocorrelations (T _Px and T _Py ) at different times and their spatial correlations Cross-correlation (R _Px and R _Py ), as shown in FIG. 6 .

和

图7(c) 给出了10束XP-CLR-PSs与10束XP-CLR-RSs在时间和空间上的相关性

图7(c)给出了10束YP-CLR-PSs与10束YP-CLR-RSs在时间和空间上的相关性

从图7(a)和7(b)中可以知道，对于第N束XP-CLR-PS，

的最大值出现在t＝0和j＝N处(N＝1,2,3,…,10, 下同)。对于第N束XP-CLR-PS的

最大值出现在t＝0和j＝N处。如图7(c)所示，对于第N束XP-CLR-PS和第N束XP-CLR-RS的

最大值出现在t＝0和j＝N处。从图7(d)中可以看出，对于第N 束YP-CLR-PS和第N束YP-CLR-RS的

最大值出现在t＝0和j＝N 处。这些表明XP-CLR-PS和YP-CLR-PS具有时间和空间不相关的特征。同理，N束XP-CLR-PSs与其对应的参考信号的时空不相关性，以及N束YP-CLR-PSs与其对应的参考信号的时空不相关性都能实现。下面，根据它们的时空不相关性，以复杂形状目标T₁和T₂中12 个小区域为例，讨论对它们的测距。From Figure 6, we can know that the maximum value of T _Px and T _Py occurs at t=0. Except for t=0, the values of T _Px and T _Py are almost zero at all other times. The peaks of R _Px and R _Py appear at j=5. On values of j other than 5, their value is equal to 0. According to companies (18)–(21), the spatiotemporal evolution of the correlation function for 10 beams of XP-CLR-PSs and 10 beams of YP-CLR-PSs is represented in Fig. 7(a) and 7(b) as

and

Figure 7(c) shows the temporal and spatial correlations between 10 beams of XP-CLR-PSs and 10 beams of XP-CLR-RSs

Figure 7(c) shows the temporal and spatial correlations between 10 beams of YP-CLR-PSs and 10 beams of YP-CLR-RSs

From Figures 7(a) and 7(b), it can be known that for the Nth bundle XP-CLR-PS,

The maximum value of appears at t=0 and j=N (N=1, 2, 3, . . . , 10, the same below). For the Nth bundle of XP-CLR-PS

The maximum occurs at t=0 and j=N. As shown in Fig. 7(c), for the Nth bundle of XP-CLR-PS and the Nth bundle of XP-CLR-RS

The maximum occurs at t=0 and j=N. It can be seen from Fig. 7(d) that for the Nth bundle of YP-CLR-PS and the Nth bundle of YP-CLR-RS

The maximum occurs at t=0 and j=N. These suggest that XP-CLR-PS and YP-CLR-PS have temporally and spatially uncorrelated features. In the same way, the spatiotemporal independence of N bundles of XP-CLR-PSs and their corresponding reference signals, and the spatiotemporal independence of N bundles of YP-CLR-PSs and their corresponding reference signals can be achieved. In the following, according to their temporal and spatial irrelevance, taking ₁₂ small regions in complex _- shaped targets T1 and T2 as examples, the ranging of them is discussed.

通过发射天线 (TA_1,1-TA_1,10)发射的10束XP-CLR-PSs用于依次探测目标A₁-A₁₂的距离。这些发射天线的位置矢量依次假定为r_1,1-r_1,10。如图8(b) 所示，T₂中12个小区域被定义为A’₁-A’₁₂，其位置矢量依次视为

通过发射天线(TA_2,1-TA_2,10)发射的10束XP-CLR-PSs用于依次探测目标A’₁-A’₁₂的距离。这些发射天线的位置矢量依次假定为r_2,1-r_2,10。此外，这些发射天线(TA_1,1-TA_1,10和TA_2,1-TA_2,10)呈线性排列，天线和天线的距离为0.5m。As shown in Fig. 8, we present the ranging geometry for ₁₂ small regions in complex _- shaped targets T1 and T2. It can be known from Figure 8(a) that the 12 small regions in T ₁ are defined as A ₁ -A ₁₂ , and then their position vectors are regarded as

10 beams of XP-CLR-PSs transmitted through transmit antennas (TA _1,1 -TA _1,10 ) were used to detect the distances of targets A ₁ -A ₁₂ in sequence. The position vectors of these transmit antennas are sequentially assumed to be r _1,1 -r _1,10 . As shown in Fig. 8(b), 12 small regions in T ₂ are defined as A' ₁ -A' ₁₂ , and their position vectors are sequentially regarded as

10 beams of XP-CLR-PSs transmitted through transmit antennas (TA _2,1 -TA _2,10 ) are used to detect the distances of targets A' ₁ -A' ₁₂ in sequence. The position vectors of these transmit antennas are sequentially assumed to be r _2,1 -r _2,10 . In addition, these transmitting antennas (TA _1,1 -TA _1,10 and TA _2,1 -TA _2,10 ) are arranged linearly, and the distance between the antenna and the antenna is 0.5m.

目标A’₁-A’₁₂的实际距离分别假定为

这些实际距离的值在表(3)和表(4) 中给出。表2中列出了两组发射天线(TA_1,1-TA_1,10和TA_2,1-TA_2,10) 的位置矢量。为了进一步描述两组12个目标的小区域的准确性，我们引进了它们的相对误差，如下所示：In order to verify the feasibility of ranging for two groups of small areas of 10 targets, we assume that the actual distances of targets A ₁ -A ₁₂ are respectively assumed to be

The actual distances of targets A' ₁ -A' ₁₂ are respectively assumed to be

The values of these actual distances are given in Tables (3) and (4). The position vectors of the two sets of transmit antennas (TA _1,1 -TA _1,10 and TA _2,1 -TA _2,10 ) are listed in Table 2. To further characterize the accuracy of small regions for the two groups of 12 objects, we introduce their relative errors as follows:

Among them, j=1, 2, 3, . . . , 12.

同理，可以得到T₁中其余小区域(A₂-A₁₂)的测量位置矢量，如表3所示。同样的办法，可以计算得出T₂中小区域(A’₁-A’₁₂)的位置矢量，如图6所示。因此，根据公式(29)，我们得到了T₁和T₂中12个小区域测距的相对误差，如表3和表4中所示。从表3和表4中我们可以观察到A₁-A₁₂的小目标的测距相对误差在0.04％和0.23％之间。对区域A’₁-A’₁₂的12个小目标的百测距相对误差在0到0.23％之间。这些结果表明，两个复杂形状目标的多区域测距具有较小的相对误差，且小于0.23％。The measured position vectors of the targets in the two groups of 12 small areas can be obtained by formulas (26) and (27). The two sets of delay times (τ _1,1 -τ _1,10 and τ _2,1 -τ _2,10 ) can be obtained by applying the maximum expected values of the correlation operations CC ₁ and CC ₂ given in equation (25). In the following, the ranging process is described by taking the small area A1 as _an example. The received signal from RA ₁ , which includes 10 beams of XP-CLR-PSs from the TA _1,1 -TA _1,10 transmit antennas to detect target A ₁ , we calculate the received signal from RA ₁ and the 10 beams of XP- The cross-correlation of CLR-RSs in time and space (CC _1,1 -CC _1,10 ) is shown in Fig. 9(b). As can be seen from the figure, the maximum expected value of the cross-correlation is located at 10 different time delays in turn. 10 time delays can be derived from Figures 9(a) and 9(c): τ ₁ =34.149ns; τ ₂ =32.770ns; τ ₃ =31.443ns; τ ₄ =30.182ns; τ ₅ =29.004ns; τ ₆ =27.932ns; τ ₇ =26.994 ns; τ ₈ =26.222 ns; τ ₉ =25.652 ns; τ ₁₀ =25.316 ns. Based on these time delays, we can obtain the precise measured position vector of the target using equations (26)-(28)

Similarly, the measured position vectors of the remaining small regions (A ₂ -A ₁₂ ) in T ₁ can be obtained, as shown in Table 3. In the same way, the position vector of the small area (A' ₁ -A' ₁₂ ) in T ₂ can be calculated, as shown in FIG. 6 . Therefore, according to Equation (29), we get the relative errors of ₁₂ small-area ranging in T1 and T2, as shown in Tables ₃ and 4. From Table 3 and Table 4 we can observe that the relative error of ranging for small targets of A ₁ -A ₁₂ is between 0.04% and 0.23%. The relative errors of 100 ranging for the 12 small targets in the area A' ₁ -A' ₁₂ are between 0 and 0.23%. These results show that the multi-area ranging of two complex-shaped targets has a small relative error of less than 0.23%.

Table 2. Position vectors for two sets of transmitting radars (TA _1,1 -TA _1,10 and TA _2,1 -TA _2,10 )

和测量的位置矢量

以及它们的相对误差。Table 3. Actual position vectors _of targets in 12 small regions in T1

and the measured position vector

and their relative errors.

和测量的位置矢量

以及它们的相对误差。Table 4. Actual position vectors of targets in ₁₂ small regions in T2

and the measured position vector

and their relative errors.

It is well known that the full width at half maximum (FWHM) of the correlation peak is often used to describe the ranging resolution. As shown in Fig. 9(d), the corresponding peak FWHM of CC _1,1 is 4/3 ps and the ranging resolution is 0.2 mm. It can be known from Figure 9(c) that the FWHMs of the correlation operations (CC _1,1 -CC _1,10 ) are all 4/3ps, which means that the ranging resolution of all small targets A ₁ -A ₁₂ in T ₁ The rate can reach 0.2mm. Similarly, the ranging resolution of all small targets A' ₁ -A' ₁₂ in T ₂ can also reach 0.2mm. In order to observe the influence of the two key parameters of injection intensity and noise intensity on the ranging resolution, Fig. 10 shows the changes of the injection intensity k _xinj (k _yinj. ) and the noise intensity β for the target A ₁ -A ₁₂ and _A'1 - _A'12 ranging resolution effects. As can be seen from this figure, their range resolution remains 0.2mm throughout, independent of injection strength and noise strength. The results show that by using two chaotic polarization radars modulated by random noise, the ranging of multiple areas of two complex-shaped targets can be achieved with a ranging resolution up to 0.2 mm. They also have excellent strong noise immunity.

In summary, we propose a novel scheme for accurate ranging of multiple regions in two complex-shaped targets by injecting light into two chaotic polarization radars generated by optically pumped spin VCSELs, where random noise is applied. Modulate two chaotic polarization radars. The two modulated chaotic polarization radars have excellent characteristics such as space-time irrelevance and fast dynamic characteristics of femtosecond level. Using these properties, the delay times from multiple regions can be obtained by observing the time position corresponding to the maximum expected value of the cross-correlation between the chaotic polarization probe waveform and its corresponding reference waveform. Based on these delay times, the position vectors of multiple regions in the two complex-shaped targets can be accurately measured. The research results show that the relative error of ranging of multi-region small targets is very low and less than 0.23%. Their resolution is very stable, up to 0.2mm, and they have excellent strong noise immunity. The attractive advantages of our proposed ranging scheme for multi-area small targets are: stable and high ranging resolution, strong noise immunity, and low required to measure multi-area target position vectors in complex shapes Relative error is low. The ranging ideas and methods proposed in our scheme have great potential for intelligent precision machining and quality detection of complex-shaped targets.

The second aspect.

Referring to FIG. 11, an embodiment of the present invention provides a multi-area ranging system based on chaotic polarization radar, including:

The polarization controller splitting module 10 is used for splitting the beam emitted by the distributed feedback laser by the polarization controller to generate a polarization component beam; wherein the polarization component beam includes an x-polarization component beam and a y-polarization component beam.

In a specific embodiment, the polarization controller dividing module 10 is further used for:

The beam emitted by the distributed feedback laser generates a beam of unidirectional propagation through an optical isolator;

The unidirectionally propagating beams are split by a polarization controller to generate polarized component beams.

The fiber polarization beam splitter splitting module 20 is used for dividing the polarization component beam into a reference signal and a detection signal through the fiber polarization beam splitter.

The reference current signal and detection current signal acquisition module 30 is used for the reference signal and detection signal to pass through the optical fiber beam splitter and the signal processing module in sequence, respectively, to obtain the reference current signal and the detection current signal.

The position vector calculation module 40 is used for the reference current signal and the detection current signal to pass through the calculation module to generate the position vector of the first ranging target; the calculation module includes: a correlation function calculation module and a target distance calculation module.

In a specific implementation manner, the position vector calculation module 40 is further configured to:

Calculate the signal correlation of the reference current signal and the detection current signal through the correlation function calculation module;

The position vector of the first ranging target is generated through the target ranging calculation module and the signal correlation.

Referring to FIG. 12 , in a specific implementation manner, the reference current signal and detection current signal acquisition module 30 includes: a detection current signal acquisition sub-module 31 for the following steps:

The detection signal is divided into at least one bundle of chaotic radar detection waveforms by the first fiber beam splitter;

The chaotic radar detection waveform obtains an incident photocurrent signal through a signal processing module; wherein, the signal processing module includes: a first noise modulator, a first signal converter, a signal amplifier and a signal transmitter;

The incident photocurrent signal is emitted to the first ranging target, and an outgoing photocurrent signal is obtained through an optical reaction; wherein, the optical reaction includes: reflection and/or scattering;

The outgoing photocurrent signal sequentially passes through the signal receiver and the signal amplifier to obtain the detection current signal.

Referring to FIG. 12 , in a specific implementation manner, the reference current signal and detection current signal acquisition module 30 further includes: a reference current signal acquisition sub-module 32 for the following steps:

The reference signal is divided into at least one bundle of chaotic radar reference waveforms by the second fiber beam splitter;

The chaotic radar reference waveform is passed through a signal processing module to obtain a reference current signal; the signal processing module includes: a second noise modulator and a second signal converter.

Claims (10)

1. a multi-region ranging method based on chaotic polarization radar, is characterized in that, comprises: The beam emitted by the distributed feedback laser is divided by a polarization controller to generate a polarization component beam; wherein the polarization component beam includes an x-polarization component beam and a y-polarization component beam; The polarization component beam is divided into a reference signal and a detection signal by a fiber polarization beam splitter; The reference signal and the detection signal pass through the optical fiber beam splitter and the signal processing module in sequence, respectively, to obtain the reference current signal and the detection current signal; The reference current signal and the detection current signal pass through a calculation module to generate a position vector of the first ranging target; the calculation module includes: a correlation function calculation module and a target range calculation module. 2. a kind of multi-region ranging method based on chaotic polarization radar as claimed in claim 1, is characterized in that, described reference signal and detection signal pass through optical fiber beam splitter and signal processing module successively respectively, obtain reference current signal and Detect current signals, including: The detection signal is divided into at least one bundle of chaotic radar detection waveforms by the first fiber beam splitter; The chaotic radar detection waveform obtains an incident photocurrent signal through a signal processing module; wherein, the signal processing module includes: a first noise modulator, a first signal converter, a signal amplifier and a signal transmitter; The incident photocurrent signal is emitted to the first ranging target, and an outgoing photocurrent signal is obtained through an optical reaction; wherein, the optical reaction includes: reflection and/or scattering; The outgoing photocurrent signal sequentially passes through the signal receiver and the signal amplifier to obtain the detection current signal. 3. a kind of multi-region ranging method based on chaotic polarization radar as claimed in claim 1, is characterized in that, described reference signal and detection signal pass through optical fiber beam splitter and signal processing module successively respectively, obtain reference current signal and Detecting current signals, also including: The reference signal is divided into at least one bundle of chaotic radar reference waveforms by the second fiber beam splitter; The chaotic radar reference waveform is passed through a signal processing module to obtain a reference current signal; the signal processing module includes: a second noise modulator and a second signal converter. 4. The multi-area ranging method based on chaotic polarization radar according to claim 1, wherein the reference current signal and the detection current signal calculation module generate the position vector of the first ranging target ,include: Calculate the signal correlation of the reference current signal and the detection current signal through the correlation function calculation module; The position vector of the first ranging target is generated through the target ranging calculation module and the signal correlation. 5. a kind of multi-area ranging method based on chaotic polarization radar as claimed in claim 1, is characterized in that, described beam emitted by distributed feedback laser is divided by polarization controller, generates polarization component beam, comprising: The beam emitted by the distributed feedback laser generates a beam of unidirectional propagation through an optical isolator; The unidirectionally propagating beams are split by a polarization controller to generate polarized component beams. 6. A multi-region ranging system based on chaotic polarization radar, is characterized in that, comprises: a polarization controller splitting module for splitting the beam emitted by the distributed feedback laser by the polarization controller to generate a polarization component beam; wherein the polarization component beam includes an x-polarization component beam and a y-polarization component beam; an optical fiber polarization beam splitter splitting module, which is used for the polarization component beam to be divided into a reference signal and a detection signal by the optical fiber polarization beam splitter; a reference current signal and a detection current signal acquisition module, used for the reference signal and the detection signal to pass through the optical fiber beam splitter and the signal processing module in sequence, respectively, to obtain the reference current signal and the detection current signal; The position vector calculation module is used for the reference current signal and the detection current signal to pass through the calculation module to generate the position vector of the first ranging target; the calculation module includes: a correlation function calculation module and a target ranging calculation module. 7. A multi-area ranging system based on chaotic polarization radar as claimed in claim 6, wherein the reference current signal and detection current signal acquisition module comprises: a detection current signal acquisition sub-module, which is used for the following step: The detection signal is divided into at least one bundle of chaotic radar detection waveforms by the first fiber beam splitter; The chaotic radar detection waveform obtains an incident photocurrent signal through a signal processing module; wherein, the signal processing module includes: a first noise modulator, a first signal converter, a signal amplifier and a signal transmitter; The incident photocurrent signal is emitted to the first ranging target, and an outgoing photocurrent signal is obtained through an optical reaction; wherein, the optical reaction includes: reflection and/or scattering; The outgoing photocurrent signal sequentially passes through the signal receiver and the signal amplifier to obtain the detection current signal. 8. The multi-area ranging system based on chaotic polarization radar as claimed in claim 6, wherein the reference current signal and detection current signal acquisition module further comprises: a reference current signal acquisition sub-module for The following steps: The reference signal is divided into at least one bundle of chaotic radar reference waveforms by the second fiber beam splitter; The chaotic radar reference waveform is passed through a signal processing module to obtain a reference current signal; the signal processing module includes: a second noise modulator and a second signal converter. 9. a kind of multi-region ranging system based on chaotic polarization radar as claimed in claim 6, is characterized in that, described position vector calculation module is also used for: Calculate the signal correlation of the reference current signal and the detection current signal through the correlation function calculation module; The position vector of the first ranging target is generated through the target ranging calculation module and the signal correlation. 10. a kind of multi-area ranging system based on chaotic polarization radar as claimed in claim 6, is characterized in that, described polarization controller dividing module is also used for: The beam emitted by the distributed feedback laser generates a beam of unidirectional propagation through an optical isolator; The unidirectionally propagating beams are split by a polarization controller to generate polarized component beams.

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