CN106125058A - The improvement mass centre angle-measuring method of metre wave radar is swept based on machine - Google Patents

Abstract

The invention belongs to Radar Technology field, disclose a kind of improvement mass centre angle-measuring method sweeping metre wave radar based on machine, to reduce centroid algorithm sensitivity the most scopodromic to antenna beam, reduce angle error, improve angle measurement accuracy；Including: the array radar echo-signal to receiving swept by machine, enter horizontal phasing control, the data obtained after processing are taken maximum amplitude, and find the angle value of correspondence, (L 1)/2 angle values (L is the pulse number that beam pattern three dB bandwidth comprises) are all taken in the left and right of this angle, and find out corresponding amplitude, use centroid method to carry out angle estimation, obtain angle estimation value θ_e.Again at θ_eLeft and right all take (L 1)/2 angle values, and find out the amplitude of correspondence, re-use centroid method and carry out angle estimation, an angle estimation value of getting back, then proceed to repeat above operation, carry out repeatedly centroid algorithm iterative processing.

Description

The improvement mass centre angle-measuring method of metre wave radar is swept based on machine

Technical field

The present invention relates to Radar Technology field, particularly relate to a kind of improvement mass centre angle measurement sweeping metre wave radar based on machine Method, can be used for center of antenna normal in mechanical scanning radar and is not aligned with during target target is carried out centroid algorithm angle measurement.

Background technology

Metre wave radar is little due to signal attenuation, and detection range is remote, has solely at the aspect such as over-the-horizon detection, Anti-amyloid-β antibody Special advantage, but simultaneously because the wavelength of metre wave radar is longer, wave beam is wider so that and its angle-resolved rate variance, angle measurement accuracy is low. Mechanical scanning radar is due to low cost, it is achieved the factor such as simple is extensively applied by people always.Mechanic scan radar angle-measuring method is general Use maximum-signal method, but the precision of this method is poor, sweeps metre wave radar especially for machine.Its electricity size is less, wave beam Wider, maximum-signal method angle measurement accuracy is the highest.And although traditional centroid algorithm is higher than maximum-signal method angle measurement accuracy, But still can not meet our demand to precision, especially when antenna centre normal is not aligned with target, traditional quality Center method angle measurement accuracy can be lower.

Traditional quality center method is simple to system requirements, only one signalling channel of need and a scanning beam, and this The operand planting angle-measuring method is few, low cost, and from the perspective of these, centroid algorithm is a kind of important method.

The angle measurement method of centroid method, is the one of amplitude of vibration method angle measurement, basic with maximum-signal method of its ultimate principle Principle is substantially the same, and no longer maximum for single amplitude is put corresponding antenna beam when difference is to determine target direction Point to as target direction, but the barycenter being determined by each echo pulse signal determines angle on target.

But being swept the shortcomings such as wider, the central beam misalignment target of metre wave radar wave beam to be affected by machine, centroid algorithm is surveyed The most scopodromic impact of angular accuracy acceptor center wave beam is very big, thus affects the resolving power of radar and detection, tracking target Accuracy, precision needs to improve further.

Summary of the invention

For the deficiency of above-mentioned prior art, embodiments of the invention provide a kind of improvement matter sweeping metre wave radar based on machine Amount center angle-measuring method, to reduce centroid algorithm sensitivity the most scopodromic to antenna beam, reduces angle error, carries High angle measurement accuracy.

The array radar echo-signal to receiving swept by the machine of the technical scheme is that, enters horizontal phasing control, after processing The data obtained take maximum amplitude, and find corresponding angle value, and all take (L-1)/2 angle value (L is in the left and right of this angle The pulse number that beam pattern three dB bandwidth comprises), and find out corresponding amplitude, use centroid method to carry out angle estimation, To angle estimation value θ_e.Again at θ_eLeft and right all take (L-1)/2 angle value, and find out the amplitude of correspondence, re-use barycenter Method carries out angle estimation, an angle estimation value of getting back, and then proceedes to repeat above operation, carries out repeatedly centroid algorithm Iterative processing.

For reaching above-mentioned purpose, embodiments of the invention adopt the following technical scheme that

A kind of improvement mass centre angle-measuring method sweeping metre wave radar based on machine, described method comprises the steps:

Step 1, the machine of setting sweeps the antenna of metre wave radar as the uniform line-array being made up of N number of array element, wherein, N for more than or Person's even number equal to 4；

Step 2, machine is swept metre wave radar and is launched K pulse, is spaced fixing preset angle between adjacent pulse；And determine i-th The reference angle of pulseI=1,2 ..., K；Wherein, reference angle is the angle of center of antenna normal and horizontal reference plane；

Step 3, machine is swept metre wave radar and is received echo-signal X of K pulse by antenna array, determines the mesh of i-th pulse Mark off-axis angle, i=1,2 ..., K, and echo-signal X is entered horizontal phasing control, obtain echo-signal Y after phase place adjusts, obtain Take pulse corresponding to maximum amplitude in echo-signal Y after phase place adjusts, and the target off-axis angle that this pulse is corresponding, be designated as the One target off-axis angle；Target off-axis angle is the angle between target and center of antenna normal；

Step 4, each side takes (L-1)/2 angle value, and returning after phase place adjusts in first object off-axis angle Ripple signal Y obtains the range value that each angle value is corresponding, forms new echo data；L is to comprise in 3dB beam angle Pulse number；

Step 5, uses mass centre's angle-measuring method to carry out angle on target estimation described new echo data, obtains target The first angle estimation value θ_e；

Step 6, by the first angle estimation value θ of described target_eThe first object off-axis angle being assigned in step 3；

Step 7, is repeated in performing step 4 and meets default error bars to step 6, the angle estimation value until target Part, and the angle estimation value obtained for the last time is defined as the final angle of target.

The present invention compared with prior art has the advantage that the present invention carries out repeatedly centroid algorithm to receiving data, will The advantage successive ignition of centroid algorithm, thus traditional quality center method is the most sensitive to quasi goal to center of antenna Shortcoming weakens, thus improves the angle measurement accuracy of centroid algorithm.

Accompanying drawing explanation

In order to be illustrated more clearly that the embodiment of the present invention or technical scheme of the prior art, below will be to embodiment or existing In having technology to describe, the required accompanying drawing used is briefly described, it should be apparent that, the accompanying drawing in describing below is only this Some embodiments of invention, for those of ordinary skill in the art, on the premise of not paying creative work, it is also possible to Other accompanying drawing is obtained according to these accompanying drawings.

A kind of reality improving mass centre's angle-measuring method sweeping metre wave radar based on machine that Fig. 1 provides for the embodiment of the present invention Existing schematic flow sheet；

Fig. 2 is to be to use the inventive method, with tradition width centroid algorithm, one target carries out the root-mean-square error of angle measurement Correlation curve schematic diagram.

Detailed description of the invention

Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clear, complete Describe, it is clear that described embodiment is only a part of embodiment of the present invention rather than whole embodiments wholely.Based on Embodiment in the present invention, it is every other that those of ordinary skill in the art are obtained under not making creative work premise Embodiment, broadly falls into the scope of protection of the invention.

A kind of improvement mass centre angle-measuring method sweeping metre wave radar based on machine, with reference to Fig. 1, described method includes walking as follows Rapid:

Step 1, the machine of setting sweeps the antenna of metre wave radar as the uniform line-array being made up of N number of array element, wherein, N for more than or Person's even number equal to 4.

Machine is swept the array antenna that the antenna of metre wave radar is equivalent to be made up of array element.The antenna equivalence of mechanic scan radar is become Array element distance d between the adjacent array element of the uniform line-array being made up of N number of array element, i.e. any two is the most equal, and is metre wave radar Launch the half of the wavelength X of signal, d=λ/2.

Step 2, machine is swept metre wave radar and is launched K pulse, is spaced fixing preset angle between adjacent pulse；And determine i-th The reference angle of pulseI=1,2 ..., K；Wherein, reference angle is the angle of center of antenna normal and horizontal reference plane.

Concrete, mechanic scan radar is with horizontal plane for reference to angle 0 °, and mechanic scan radar is when antenna scanning works, at interval of solid Determine preset angle and launch a pulse, in 3dB beam angle, have L pulse, during angle measurement, launch antenna and launch K pulse, K Containing L pulse in pulse, when will launch i-th pulse, the angle of center of antenna normal and horizontal reference plane is as benchmark AngleI=1,2 ..., K.

In step 2, machine is swept metre wave radar and is launched K pulse, and between adjacent pulse, the fixing preset angle in interval is particularly as follows: machine is swept Metre wave radar, when antenna scanning works, is launched a pulse at interval of fixing preset angle △ Φ, and is wrapped in 3dB beam angle Containing L pulse；Wherein, △ Φ=360*tT, t is the pulse repetition period, and T is the rotating speed that metre wave radar swept by machine.

It is engraved in rotation, so center of antenna normal is change during due to mechanical radar.

Step 3, machine is swept metre wave radar and is received echo-signal X of K pulse by antenna array, determines the mesh of i-th pulse Mark off-axis angle, i=1,2 ..., K, and echo-signal X is entered horizontal phasing control, obtain echo-signal Y after phase place adjusts, obtain Take pulse corresponding to maximum amplitude in echo-signal Y after phase place adjusts, and the target off-axis angle that this pulse is corresponding, be designated as the One target off-axis angle；Target off-axis angle is the angle between target and center of antenna normal.

Step 3 particularly as follows:

(3a) machine is swept metre wave radar and is received echo-signal X=AS+n of K pulse, wherein, A=[a by antenna array (θ₁),...a(θ_i)...,a(θ_K)] represent the target phase information that echo-signal comprises, a (θ_i)=[1, exp (j2 π d/ λ sin θ_i),...,exp(j2π(N-1)d/λsinθ_i)]^TFor the target off-axis angle vector of i-th pulse, i=1,2 ..., K；D is battle array Unit interval, λ is signal wavelength, represents the transposition of vector；

S=[S₁,...S_i...,S_K]^TRepresent the complex envelope of echo-signal, S_iRepresent the complex envelope information of i-th pulse,Wherein f_dRepresent the Doppler frequency of target, f_d=2Vf₀/ c, V represent that target sweeps metre wave radar relative to machine Radial velocity, f₀Representing the mid frequency of radar emission signal, c represents the light velocity, and t is the pulse repetition period；N represents average 0, variance is N × K rank white Gaussian noise matrix of 1；Exp represents the exponential depth with e as the end, and j represents imaginary unit.

(3b) echo-signal X is entered horizontal phasing control, obtain the echo-signal Y=a (θ after phase place adjusts₀) X, it is assumed that The actual angle of target is θ₀, a (θ₀)=[1, exp (j2 π d/ λ sin (θ₀)),…,exp(j2π(N-1)d/λsin(θ₀))]^T；

It should be noted that the actual angle of the target described in the present embodiment is the mesh estimated according to prior information in advance Target angle, belongs to the category of rough estimate, and the present invention is that the angle to target is accurately estimated.

(3c) obtain pulse corresponding to maximum amplitude in echo-signal Y after phase place adjusts, and this pulse corresponding the One target off-axis angle θ_max。

Step 4, each side takes (L-1)/2 angle value, and returning after phase place adjusts in first object off-axis angle Ripple signal Y obtains the range value that each angle value is corresponding, forms new echo data；L is to comprise in 3dB beam angle Pulse number.

Step 5, uses mass centre's angle-measuring method to carry out angle on target estimation described new echo data, obtains target The first angle estimation value θ_e。

Step 5 particularly as follows:

(5a) by (L-1)/2 angle value taken on the left of first object off-axis angle, take on the right side of first object off-axis angle (L-1)/2 angle value and first object off-axis angle be designated as θ_l, l=1 ..., L, and the range value of its correspondence is designated as a_l, l =1 ..., L, thus obtain new echo data；

(5b) use mass centre's angle-measuring method to carry out angle on target estimation described new echo data, obtain target First angle estimation value θ_e:

${\mathrm{\θ}}_e=\underset{l=1}{\overset{L}{\Σ}}{\mathrm{\θ}}_l{a}_l/\underset{l=1}{\overset{L}{\Σ}}{a}_l.$

Step 6, by the first angle estimation value θ of described target_eThe first object off-axis angle being assigned in step 3.

Step 7, is repeated in performing step 4 and meets default error bars to step 6, the angle estimation value until target Part, and the angle estimation value obtained for the last time is defined as the final angle of target.

Until the angle estimation value of target meets default error condition particularly as follows: until the angle of target is estimated in step 7 The root-mean-square error of evaluation reduces to original 1/5.Root-mean-square error originally refers to not carry out root before technical solution of the present invention According to the rough angle of the target that prior information obtains, according to the root-mean-square error of rough angle calculation.

The effect of the present invention can be verified by machine calculated below emulation:

One, simulated conditions

Simulated conditions: assume the antenna surface that antenna is made up of 10 array elements, the beam angle of antenna is about 20 °, antenna Carrying out rotation sweep with the speed of 10s/r, it is the pulse of 300MHz that radar launches a frequency every 5ms, and antenna receives every time To 55 pulse signals, center of antenna normal is not aligned with target, center of antenna deviation 4 pulses of target；Assume to have one Target, the real angle of target is 10 °, and signal to noise ratio takes-10dB to 10dB, and signal to noise ratio here refers to single array element, single arteries and veins Punching.

Two, emulation content

When utilizing simulated conditions 1 to only one of which target, it is respectively adopted traditional quality center method and the inventive method is carried out Angle measurement, obtains the root-mean-square error curve that two kinds of methods change with signal to noise ratio, as in figure 2 it is shown, abscissa is signal to noise ratio in Fig. 2, Vertical coordinate is root-mean-square error.

From Figure 2 it can be seen that the inventive method is higher than traditional quality center method precision, particularly when signal to noise ratio is low, effect Clearly, the inventive method can reduce effect of noise, improves angle measurement accuracy.

The above, the only detailed description of the invention of the present invention, but protection scope of the present invention is not limited thereto, and any Those familiar with the art, in the technical scope that the invention discloses, can readily occur in change or replace, should contain Cover within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with described scope of the claims.

Claims (4)

1. the improvement mass centre angle-measuring method sweeping metre wave radar based on machine, it is characterised in that described method includes as follows Step:

Step 1, the antenna of metre wave radar swept by the machine of setting is more than or equal to 4 as the uniform line-array being made up of N number of array element, N Even number；

Step 2, machine is swept metre wave radar and is launched K pulse, is spaced fixing preset angle between adjacent pulse；And determine i-th pulse Reference angleI=1,2 ..., K；Wherein, reference angle is the angle of center of antenna normal and horizontal reference plane；

Step 3, machine is swept metre wave radar and is received echo-signal X of K pulse by antenna array, determines that the target of i-th pulse is inclined Shaft angle, i=1,2 ..., K, and echo-signal X is entered horizontal phasing control, obtain echo-signal Y after phase place adjusts, obtain phase The pulse that in echo-signal Y after the adjustment of position, maximum amplitude is corresponding, and the target off-axis angle that this pulse is corresponding, be designated as the first mesh Mark off-axis angle；Target off-axis angle is the angle between target and center of antenna normal；

Step 4, each side takes (L-1)/2 angle value, and the echo letter after phase place adjusts in first object off-axis angle Obtain the range value that each angle value is corresponding in number, form new echo data；L is the pulse comprised in 3dB beam angle Number；

Step 5, uses mass centre's angle-measuring method to carry out angle on target estimation described new echo data, obtains the of target One angle estimation value θ_e；

Step 6, by the first angle estimation value θ of described target_eThe first object off-axis angle being assigned in step 3；

Step 7, is repeated in performing step 4 and meets default error condition to step 6, the angle estimation value until target, and The angle estimation value obtained for the last time is defined as the final angle of target.

A kind of improvement mass centre angle-measuring method sweeping metre wave radar based on machine the most according to claim 1, its feature exists In, in step 2, machine sweep metre wave radar launch K pulse, between adjacent pulse interval fix preset angle particularly as follows:

Machine sweeps metre wave radar when antenna scanning works, and launches a pulse at interval of fixing preset angle ΔΦ, and at 3dB wave beam L pulse is comprised in width；Wherein, ΔΦ=360*t/T, t are the pulse repetition period, and T is the rotating speed that metre wave radar swept by machine.

A kind of improvement mass centre angle-measuring method sweeping metre wave radar based on machine the most according to claim 1, its feature exists In, step 3 particularly as follows:

(3a) machine is swept metre wave radar and is received echo-signal X=AS+n of K pulse, wherein, A=[a (θ by antenna array₁) ... a (θ_i) ..., a (θ_K)] represent the target phase information that echo-signal comprises, a (θ_i)=[1, exp (j2 π d/ λ sin θ_i) ..., exp(j2π(N-1)d/λsinθ_i)]^TFor the target off-axis angle vector of i-th pulse, i=1,2 ..., K；D is array element interval, λ For signal wavelength, represent the transposition of vector；

S=[S₁... S_i..., S_K]^TRepresent the complex envelope of echo-signal, S_iRepresent the complex envelope information of i-th pulse,Wherein f_dRepresent the Doppler frequency of target, f_d=2Vf₀/ c, V represent that target sweeps metre wave radar relative to machine Radial velocity, f₀Representing the mid frequency of radar emission signal, c represents the light velocity, and t is the pulse repetition period；N represents average 0, variance is N × K rank white Gaussian noise matrix of 1；

(3b) echo-signal X is entered horizontal phasing control, obtain the echo-signal Y=a (θ after phase place adjusts₀) X, wherein, θ₀For The actual angle of target, a (θ₀)=[1, exp (j2 π d/ λ sin (θ₀)) ..., exp (j2 π (N-1) d/ λ sin (θ₀))]^T；

(3c) obtain pulse corresponding to maximum amplitude in echo-signal Y after phase place adjusts, and target corresponding to this pulse is inclined Shaft angle, is designated as first object off-axis angle θ_max。

A kind of improvement mass centre angle-measuring method sweeping metre wave radar based on machine the most according to claim 1, its feature exists In, step 5 particularly as follows:

(5a) by (L-1)/2 angle value taken on the left of first object the off-axis angle, (L-that takes on the right side of first object off-axis angle 1)/2 angle values and first object off-axis angle are designated as θ the most successively_l, l=1 ..., L, and the range value of its correspondence is remembered For a_l, l=1 ..., L, thus obtain new echo data；

(5b) use mass centre's angle-measuring method to carry out angle on target estimation described new echo data, obtain the first of target Angle estimation value θ_e:

${\mathrm{\θ}}_e=\underset{l=1}{\overset{L}{\Σ}}{\mathrm{\θ}}_l{a}_l/\underset{l=1}{\overset{L}{\Σ}}{a}_l.$