CN102520436B - Carrier resonance receiving type water target detection device - Google Patents

Abstract

The invention discloses a carrier resonance receiving type water target detection device, which comprises a receiver, a signal conditioning circuit, a signal processor and a power supply manager, wherein the receiver, the signal conditioning circuit and the signal processor are connected together sequentially; and the power supply manager is respectively connected with the receiver, the signal conditioning circuit and the signal processor. According to the carrier resonance receiving type water target detection device, a target is detected through sensing a forced resonance signal generated by a carrier under being excitated by a target radiation noise by adopting a manner of arranging an accelerometer on the inner wall of a housing inside the carrier, and a target motion parameter is resolved, and demands on the aspects of underwater guard, self protection and the like of an underwater carrier are met; and the accelerometer is attached on the inner wall of the housing for receiving the forced resonance signal without being in contact with an external medium, thus the carrier resonance receiving type water target detection device has the advantages of shock resistance, compressionand corrosion resistance, flexibility and convenience in an installation mode.

Description

Object detecting device in a kind of carrier resonance receiving type water

Technical field

The present invention relates to target detection technique field in the water, relate in particular to object detecting device in a kind of carrier resonance receiving type water.

Background technology

Because sound wave has good propagation characteristic in water, object detecting device is underwater sound equipment substantially in water of carrying such as (as subsurface buoy) therefore at present under water on the carrier, its transducer need be installed in hull outside, contact and install additional kuppe with aqueous medium, and then link to each other with the electronic device that is installed in enclosure interior by lead.It is very high that the weak point of this transducer mounting means and side connecting conductor formula is that the watertightness performance to housing requires, and increased design difficulty; And transducer easily is corroded or marine growth adheres to, and damage easily, performance reduce even lost efficacy under the situation that is subjected to outside thump.In addition, in some cases, can kuppe be installed in the transducer outside, but the kuppe material is difficult to satisfy simultaneously mechanical property, the design of stream shape and acoustics performance requirement, and is not easy to install.

Summary of the invention

The objective of the invention is for object detecting device in a kind of carrier resonance receiving type water is provided, with carrier under water as the wet end section that receives, employing invests the mode that inner walls is installed accelerometer in carrier inside, the resonance signal that is forced to that produces under the target radiated noise excitation by the perception carrier detects target, and calculate the parameters of target motion, the demand of aspects such as satisfied carrier is under water guarded against under water, self-protection, and avoided the problems referred to above and difficulty effectively.

The objective of the invention is to be achieved through the following technical solutions:

This device comprises and the present invention includes receiver, signal conditioning circuit, signal processor and power supervisor; Wherein receiver, signal conditioning circuit link to each other and link to each other with signal processor order successively, and power supervisor links to each other respectively with receiver, signal conditioning circuit, signal processor;

Described power supervisor provides stabilized voltage supply for this device;

Described receiver comprises a pair of accelerometer in order to received vector forced vibration signal, is symmetrical in the carrier axis in the mode of subtend adhesion and is installed on the main casing inwall of carrier, and output two-way carrier forced vibration signal is given signal conditioning circuit;

Described signal conditioning circuit will amplify the also processing of filter away high frequency noise after the two-way carrier forced vibration signal stack that receive, and the carrier forced vibration signal s (t) after output is handled gives signal processor;

Carrier forced vibration signal s (t) after described signal processor is handled signal conditioning circuit resolves, and calculates speed, distance abeam and the beam of target constantly;

The concrete grammar that resolves is as follows:

Step 1: with the carrier forced vibration signal s (t) after the signal conditioning circuit processing, adopt fast Fourier transform (FFT) to transform to frequency domain;

Step 2: do the selection at frequency domain resonance spectrum peak by dichotomy, obtain resonance spectrum peak value P (f) and respective frequencies f thereof _P, utilize f _PObtain the frequency variance of resonance spectrum peak value correspondence

When satisfying condition

And during P (f)＞β, make the judgement of " detecting target occurs ", connect step 3; Otherwise then return step 1 up to adjudicating to till having target to occur; Wherein, α and β are respectively the fixed thresholds that presets;

Step 3: at the carrier forced vibration signal s (t) in the setting-up time section before the current time t, adopt the short time discrete Fourier transform method, slide and estimate the instantaneous frequency of resonance spectrum peak value, each sliding time is exported a result at interval, obtains the sequence of the instantaneous frequency at one group of resonance spectrum peak of surveying at last

Step 4: the parameter priori space with predefined target velocity, distance abeam and beam span constantly constitutes, equally spaced be divided into a plurality of grids, be cost function with formula (1) then, the corresponding one group of parameter (v of each grid ₀, R ₀, t ₀) the corresponding cost function value Φ (R of difference substitution formula (1) calculating ₀, v ₀, t ₀):

$\mathrm{\Φ}(R_0,v_0,t_0)=$

$E<{\left\{\right[1+\frac{v_0^2\left({t-t}_0\right)}{c\sqrt{R_0^2+v_0^2{\left({t-t}_0\right)}^2}}]\hat{f}\left(t\right)-E<[1+\frac{v_0^2\left({t-t}_0\right)}{c\sqrt{R_0^2+v_0^2{\left({t-t}_0\right)}^2}}]\hat{f}\left(t\right)>\}}^2>---\left(1\right)$

v ₀, R ₀, t ₀The target velocity of respectively corresponding each grid, distance abeam and beam are constantly; C is the velocity of sound in this device place medium; E＜〉expression is with sequence

In each element

Calculate the series of computation result in the substitution＜〉, then result of calculation is averaging;

Step 5: compare the corresponding cost function value of each grid, get one group of parameter of minimum value correspondence as the estimated result of current time t;

Step 6: return step 3, estimate the new corresponding instantaneous frequency in resonance spectrum peak constantly, adopt the instantaneous frequency at the resonance spectrum peak in this new moment to replace resonance spectrum peak frequency sequence

In constantly the instantaneous frequency at resonance spectrum peak the earliest, and at after upgrading

Repeating step four to five calculates the parameter estimation result in the new moment, in circulation execution in step three in the step 5, the device step that whether judgement has target to occur in execution in step two always, and when making the judgement of " driftlessness appearance ", withdraw from the circulation of step 3～step 5.

Beneficial effect of the present invention:

This device under water carrier as the wet end section that receives, employing invests the mode that inner walls is installed accelerometer in carrier inside, the resonance signal that is forced to that produces under the target radiated noise excitation by the perception carrier detects target, and calculate the parameters of target motion, the demand of aspects such as satisfied carrier is under water guarded against under water, self-protection.

2. accelerometer of the present invention invests the inner walls reception and needn't contact external agency, shock resistance, withstand voltage corrosion-resistant, mounting means flexible and convenient.

3. the present invention adopts low-power consumption, modular design, and volume is little, in light weight, utonomous working for a long time.

Description of drawings

Fig. 1 is structural representation block diagram of the present invention.

Fig. 2 is the installation site synoptic diagram of accelerometer.

Fig. 3 is the signal processing flow figure of object detecting device in the carrier resonance receiving type water.

Embodiment

In order to understand technical scheme of the present invention better, below in conjunction with drawings and the specific embodiments the present invention is done to describe in further detail.

As shown in Figure 1: this device comprises and the present invention includes receiver, signal conditioning circuit, signal processor and power supervisor; Wherein receiver, signal conditioning circuit link to each other and link to each other with signal processor order successively, and power supervisor links to each other respectively with receiver, signal conditioning circuit, signal processor;

This device is equipped on as shown in Figure 2 the carrier, described receiver comprises a pair of accelerometer in order to received vector forced vibration signal, be symmetrical in the carrier axis in the mode of subtend adhesion and be installed on the main casing inwall of carrier, output two-way carrier forced vibration signal s (t) gives signal conditioning circuit; Wherein, the line between the two sensors installation site is the z axle, and the carrier axis is the x axle, and the two is vertical mutually, constitutes a three-dimensional system of coordinate with the y axle, and O is initial point.The receiving side signal formula of described receiver be with carrier as the wet end section that receives, institute's perception and the signal that is used be carrier under the target radiated noise excitation, produce be forced to resonance signal.

Described power supervisor provides stabilized voltage supply for this device;

Described signal conditioning circuit will amplify the also processing of filter away high frequency noise after the two-way carrier forced vibration signal stack that receive, and the carrier forced vibration signal s (t) after output is handled gives signal processor;

Carrier forced vibration signal s (t) after described signal processor is handled signal conditioning circuit resolves, and calculates speed, distance abeam and the beam of target constantly; The concrete grammar that resolves such as Fig. 3:

Step 1: with the carrier forced vibration signal s (t) after the signal conditioning circuit processing, adopt fast Fourier transform (FFT) to transform to frequency domain;

Step 2: do the selection at frequency domain resonance spectrum peak by dichotomy, obtain resonance spectrum peak value P (f) and respective frequencies f thereof _P, utilize f _PObtain the frequency variance of resonance spectrum peak value correspondence

When satisfying condition

And during P (f)＞β, make the judgement of " detecting target occurs ", connect step 3; Otherwise then return step 1 up to adjudicating to till having target to occur; Wherein, α and β are respectively the fixed thresholds that presets;

Step 3: at the carrier forced vibration signal s (t) in the setting-up time section before the current time t, adopt the short time discrete Fourier transform method, slide and estimate the instantaneous frequency of resonance spectrum peak value, each sliding time is exported a result at interval, obtains the sequence of the instantaneous frequency at one group of resonance spectrum peak of surveying at last

Step 4: the parameter priori space with predefined target velocity, distance abeam and beam span constantly constitutes, equally spaced be divided into a plurality of grids, be cost function with formula (1) then, the corresponding one group of parameter (v of each grid ₀, R ₀, t ₀) the corresponding cost function value Φ (R of difference substitution formula (1) calculating ₀, v ₀, t ₀):

$\mathrm{\&Phi;}(R_0,v_0,t_0)=$

$E<{\left\{\right[1+\frac{v_0^2\left({t-t}_0\right)}{c\sqrt{R_0^2+v_0^2{\left({t-t}_0\right)}^2}}]\hat{f}\left(t\right)-E<[1+\frac{v_0^2\left({t-t}_0\right)}{c\sqrt{R_0^2+v_0^2{\left({t-t}_0\right)}^2}}]\hat{f}\left(t\right)>\}}^2>---\left(1\right)$

v ₀, R ₀, t ₀The target velocity of respectively corresponding each grid, distance abeam and beam are constantly; C is the velocity of sound in this device place medium; E＜〉expression is with sequence In each element

Calculate the series of computation result in the substitution＜〉, then result of calculation is averaging;

Step 5: compare the corresponding cost function value of each grid, get one group of parameter of minimum value correspondence as the estimated result of current time t;

Step 6: return step 3, estimate the new corresponding instantaneous frequency in resonance spectrum peak constantly, adopt the instantaneous frequency at the resonance spectrum peak in this new moment to replace resonance spectrum peak frequency sequence

In constantly the instantaneous frequency at resonance spectrum peak the earliest, and at after upgrading

Repeating step four to five calculates the parameter estimation result in the new moment, in circulation execution in step three in the step 5, the device step that whether judgement has target to occur in execution in step two always, and when making the judgement of " driftlessness appearance ", withdraw from the circulation of step 3～step 5.

Wherein the derivation of cost function is as follows:

Be f to centre frequency ₀Target because Doppler shift, t arbitrarily constantly the theoretical value of resonance spectrum peak frequency f (t) satisfy:

$f\left(t\right)={[1+\frac{v_0^2\left({t-t}_0\right)}{c\sqrt{R_0^2+v_0^2{\left({t-t}_0\right)}^2}}]}^{-1}{f}_0---\left(1^{,}\right)$

Wherein, c is the velocity of sound in this device place medium.Disturb if further contemplate diversity of settings, then Shi Ce resonance spectrum peak frequency

And should satisfy following relation between its measuring error e (t):

$\hat{f}\left(t\right)={[1+\frac{v_0^2\left({t-t}_0\right)}{c\sqrt{R_0^2+v_0^2{\left({t-t}_0\right)}^2}}]}^{-1}{f}_0+e\left(t\right)---\left(2\right)$

Wherein, centre frequency f ₀Be a constant, the resonance spectrum peak frequency of measuring error e (t) and actual measurement

It all is stochastic variable.Can get f by following formula ₀The expression formula that satisfies:

$f_0=[1+\frac{v_0^2\left({t-t}_0\right)}{c\sqrt{R_0^2+v_0^2{\left({t-t}_0\right)}^2}}][\hat{f}\left(t\right)-e\left(t\right)]---\left(3\right)$

Suppose that resonance spectrum peak frequency error measurement e (t) satisfies the Gaussian distribution of 0 average, so respectively average statistical being got on formula (3) both sides can get:

$f_0=E<{\hat{f}}_0\left(t\right)>=E<[1+\frac{v_0^2\left({t-t}_0\right)}{c\sqrt{R_0^2+v_0^2{\left({t-t}_0\right)}^2}}]\hat{f}\left(t\right)>---\left(4\right)$

Wherein, E＜〉expression time average.Formula (4) shows: if parameters R ₀, v ₀And t ₀Known, then in a certain amount of time, by the resonance spectrum peak frequency of receiving hydrophone actual measurement

Directly substitution Doppler shift relational expression (1 ') can estimate to obtain a centre frequency sequence

The average of this sequence just equals the true value f of target's center's frequency ₀, and the variance of this sequence can be written as:

$\mathrm{\&Phi;}(R_0,v_0,t_0)=$

$E<{\left\{\right[1+\frac{v_0^2\left({t-t}_0\right)}{c\sqrt{R_0^2+v_0^2{\left({t-t}_0\right)}^2}}]\hat{f}\left(t\right)-E<[1+\frac{v_0^2\left({t-t}_0\right)}{c\sqrt{R_0^2+v_0^2{\left({t-t}_0\right)}^2}}]\hat{f}\left(t\right)>\}}^2>---\left(1\right)$

In principle, has only parameters R in formula (5) ₀, v ₀And t ₀When getting their true value respectively, variance Φ (R ₀, v ₀, t ₀) just get minimum value.Therefore, can estimate to obtain the kinematic parameter of target by minimizing following formula.

To finishing the carrier of different mission tasks, parameters of target motion estimated result can be exported to control system or the data recording equipment storage of carrier as requested.

In sum, more than be preferred embodiment of the present invention only, be not for limiting protection scope of the present invention.Within the spirit and principles in the present invention all, any modification of doing, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (1)

1. object detecting device in the carrier resonance receiving type water is characterized in that this device comprises receiver, signal conditioning circuit, signal processor and power supervisor; Wherein receiver, signal conditioning circuit and link to each other with signal processor order successively, power supervisor links to each other respectively with receiver, signal conditioning circuit, signal processor;

Described power supervisor is used to this device that stabilized voltage supply is provided;

Described receiver comprises a pair of accelerometer in order to received vector forced vibration signal, is symmetrical in the carrier axis in the mode of subtend adhesion and is installed on the main casing inwall of carrier, and output two-way carrier forced vibration signal is given signal conditioning circuit;

Described signal conditioning circuit will amplify the also processing of filter away high frequency noise after the two-way carrier forced vibration signal stack that receive, and the carrier forced vibration signal s (t) after output is handled gives signal processor;

Carrier forced vibration signal s (t) after described signal processor is handled signal conditioning circuit resolves, and calculates speed, distance abeam and the beam of target constantly;

The concrete grammar that resolves is as follows:

Step 1: with the carrier forced vibration signal s (t) after the signal conditioning circuit processing, adopt fast Fourier transform (FFT) to transform to frequency domain;

Step 2: do the selection at frequency domain resonance spectrum peak by dichotomy, obtain resonance spectrum peak value P (f) and respective frequencies f thereof _P, utilize f _PObtain the frequency variance of resonance spectrum peak value correspondence

When satisfying condition

And during P (f)＞β, make the judgement of " detecting target occurs ", connect step 3; Otherwise then return step 1 up to adjudicating to till having target to occur; Wherein, α and β are respectively the fixed thresholds that presets;

Step 3: at the carrier forced vibration signal s (t) in the setting-up time section before the current time t, adopt the short time discrete Fourier transform method, slide and estimate the instantaneous frequency of resonance spectrum peak value, each sliding time is exported a result at interval, obtains the sequence of the instantaneous frequency at one group of resonance spectrum peak of surveying at last

Step 4: the parameter priori space with predefined target velocity, distance abeam and beam span constantly constitutes, equally spaced be divided into a plurality of grids, be cost function with formula (1) then, the corresponding one group of parameter (v of each grid ₀, R ₀, t ₀) the corresponding cost function value Φ (R of difference substitution formula (1) calculating ₀, v ₀, t ₀):

v ₀, R ₀, t ₀The target velocity of respectively corresponding each grid, distance abeam and beam are constantly; C is the velocity of sound in this device place medium; E＜〉represent sequence

In each element Substitution＜in calculate the series of computation result, then result of calculation is averaging;

Step 5: compare the corresponding cost function value of each grid, get one group of parameter of minimum value correspondence as the estimated result of current time t;

Step 6: return step 3, estimate the new corresponding instantaneous frequency in resonance spectrum peak constantly, adopt the instantaneous frequency at the resonance spectrum peak in this new moment to replace resonance spectrum peak frequency sequence

In constantly the instantaneous frequency at resonance spectrum peak the earliest, and at after upgrading Repeating step four to five calculates the parameter estimation result in the new moment, in circulation execution in step three in the step 5, the object detecting device step that whether judgement has target to occur in execution in step two always in the described carrier resonance receiving type water, and when making the judgement of " driftlessness appearance ", withdraw from the circulation of step 3～step 5.

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