CN109323634A - Method based on the linear frequency modulation short-range detecting systematic survey shell angle of fall - Google Patents
Method based on the linear frequency modulation short-range detecting systematic survey shell angle of fall Download PDFInfo
- Publication number
- CN109323634A CN109323634A CN201710643908.8A CN201710643908A CN109323634A CN 109323634 A CN109323634 A CN 109323634A CN 201710643908 A CN201710643908 A CN 201710643908A CN 109323634 A CN109323634 A CN 109323634A
- Authority
- CN
- China
- Prior art keywords
- signal
- phase
- fall
- difference
- angle
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F42—AMMUNITION; BLASTING
- F42B—EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION
- F42B35/00—Testing or checking of ammunition
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Radar Systems Or Details Thereof (AREA)
Abstract
The invention discloses a kind of method based on the linear frequency modulation short-range detecting systematic survey shell angle of fall, includes the following steps: for two-way reception signal to be mixed, obtain difference frequency signal；FFT is done to two-way difference frequency signal, highest spectral peak is searched for, calculates the phase of highest spectral peak, the phase of gained two-way spectral peak is subtracted each other, obtain two-way difference frequency signal phase difference；According to the phase difference measured, the shell angle of fall is calculated with phase comparing method.The high-acruracy survey of phase difference may be implemented in the present invention, and then can accurately measure the angle of fall, has stronger anti-interference.
Description
Technical field
The present invention relates to short-range detecting technologies, especially a kind of to be based on the linear frequency modulation short-range detecting systematic survey shell angle of fall
Method.
Background technique
Currently, linear frequency modulation short-range detecting system is due to the advantages that its is small in size, structure is simple, precision is high, low in cost,
It is widely applied in every field.
But the research of linear frequency modulation short-range detecting system angle measurement is seldom, linear frequency modulation short-range detecting system uses
Phase comparing method can carry out angle measurement, and the key of phase comparing method is the phase difference for finding out two-way echo-signal, currently, phase difference detection had
Balance method, correlation method, since zero-crossing method requires relatively high, poor anti jamming capability to signal-to-noise ratio, correlation method requires strictly whole
Periodic sampling, and be difficult to harmonic carcellation interference, therefore, existing phase difference detection method is all difficult to apply to that signal-to-noise ratio is low, precision
High, strong real-time system.
Summary of the invention
The purpose of the present invention is to provide a kind of method based on the linear frequency modulation short-range detecting systematic survey shell angle of fall, solutions
Certainly linear frequency modulation short-range detecting system surveys angle of fall problem.
Realize the technical solution of the object of the invention are as follows: a kind of based on the linear frequency modulation short-range detecting systematic survey shell angle of fall
Method includes the following steps:
Mixing: two-way reception signal is mixed, difference frequency signal is obtained；
FFT method phase difference detection: FFT is done to two-way difference frequency signal, highest spectral peak is searched for, calculates the phase of highest spectral peak
Position, the phase of gained two-way spectral peak is subtracted each other, two-way difference frequency signal phase difference is obtained；
It calculates the angle of fall: according to the phase difference measured, calculating the shell angle of fall with phase comparing method.
Compared with prior art, remarkable advantage of the invention are as follows: the present invention is based on linear frequency modulation short-range detecting systematic surveys
The high-acruracy survey of phase difference may be implemented in the method for the shell angle of fall, and then can accurately measure the angle of fall, and has stronger anti-
Interference.
Detailed description of the invention
Fig. 1 is frequency-time chart of sawtooth phase modulation signal.
Fig. 2 is that FFT method of the invention surveys phase difference broad flow diagram.
Fig. 3 is the schematic diagram that the present invention measures angle of fall value when signal-to-noise ratio is 20dB.
Fig. 4 is the schematic diagram that the present invention measures value error in the angle of fall when signal-to-noise ratio is 20dB.
Fig. 5 is the schematic diagram that the present invention measures angle of fall value when signal-to-noise ratio is 10dB.
Fig. 6 is the schematic diagram that the present invention measures value error in the angle of fall when signal-to-noise ratio is 10dB.
Fig. 7 is the schematic diagram that the present invention measures angle of fall value when signal-to-noise ratio is 3dB.
Fig. 8 is the schematic diagram that the present invention measures angle of fall value error when signal-to-noise ratio is 3dB.
Specific embodiment
A method of based on the linear frequency modulation short-range detecting systematic survey shell angle of fall, include the following steps:
Mixing: two-way reception signal is mixed, difference frequency signal is obtained；
FFT method phase difference detection: FFT is done to two-way difference frequency signal, highest spectral peak is searched for, calculates the phase of highest spectral peak
Position, the phase of gained two-way spectral peak is subtracted each other, two-way difference frequency signal phase difference is obtained；
It calculates the angle of fall: according to the phase difference measured, calculating the shell angle of fall with phase comparing method.
Further, the detailed process of mixing are as follows:
Frequency-time curve of sawtooth phase modulation signal is as shown in Figure 1, be divided into two sections, area for a cycle
Between one be formula area, section two be region of disorder.
Transmitting signal frequency expression be
The frequency representation formula of echo-signal is at fuse receiving antenna 1
τ is the delay of echo-signal relative transmission signal, f0For carrier frequency, Δ FMFor modulating bandwidth, TMFor frequency modulation week
Phase,t0For the initial position corresponding time；
Using the π ∫ fdt of relational expression φ=2 of frequency and phase, obtains transmitting signal and receive the instantaneous phase of signal
Difference；Within the single linear frequency modulation period, transmitting signal is found out respectively and receives the instantaneous phase of signal；
WhenWhen, difference frequency signal is in formula area, and the phase expression formula for emitting signal is
WhenWhen, difference frequency signal is in irregular area, emits the phase expression formula of signal
Are as follows:
Wherein, C is constant；
From the continuity of signal phase:Then
WhenWhen, the phase expression formula for receiving signal is
Then whenWhen, transmitting signal is with the instantaneous phase difference for receiving signal
Δφ1=| φR-φT1|=2 π (τ Δ FMfmt+f0τ-τΔFMfmt0)
Due to T in real systemmThe signal of formula area part is mainly studied much larger than τ, therefore in signal analysis process.
Emitting signal with echo-signal is cos (Δ φ by the lower form for being mixed to obtain difference frequency signaln), then difference frequency signal
Expression formula be
cos(Δφ1)=cos2 π (Δ FMfmτt+f0τ-τΔFMfmt0)
=cos2 π (Δ FMfmτt+f0R/c+f0R1/c-τΔFMfmt0)
Then the received another way signal of antenna 2 is by the expression formula that lower mixing obtains difference frequency signal
cos(Δφ2)=cos2 π (Δ FMfmτt+f0R/c+f0R2/c-τΔFMfmt0)
Two-way difference frequency signal phase difference is 2f0(R1-R2)/c, R1、R2Respectively receiving antenna 1 and receiving antenna 2 arrive ground
Distance, R be transmitting antenna to the distance on ground, c is the light velocity, wherein R1-R2=Lsin α, L are antenna spacing, and α is the angle of fall, this
Total phase meter of sample, two paths of signals is shown as
For the wavelength for emitting signal；
It can be seen that being mixed under phase offset unanimous circumstances caused by receiving system signal processing itself in two-way
Afterwards, the phase difference that two receiving antennas receive signal remains unchanged.Therefore, after low-frequency amplifier, two-way is obtained with phase discriminator
Total phase difference φ of signal, to can get angle information α.
Further, the detailed process of FFT method phase difference detection are as follows:
Two paths of signals is sampled first；
Secondly FFT transform is carried out, their phases at peak value spectral line are then found out according to following formula；
X1(k) and X2(k) sequence obtained after FFT is done for two-way difference frequency signal；
imag(X1And real (X (k))1(k)) imaginary part and real part are respectively indicated；
Finally the phase of two paths of signals is subtracted each other and finds out phase difference:
Total phase difference φ of two paths of signals in order to obtain measures phase difference φ using FFT phase difference detection method, is based on
The phase difference detection method of DFT spectrum analysis has good rejection ability to noise and harmonic wave interference, and FFT method is the one of DFT method
Kind fast algorithm, FFT method survey the principle of phase difference: sampling first to two paths of signals；Secondly FFT transform is carried out, is then divided
Their phases at peak value spectral line are not found out；Finally the phase of two paths of signals is subtracted each other and finds out phase difference；
If the system two-way to be measured is the same as the expression formula of frequency sinusoidal signal are as follows:
In formula, A1、A2The respectively amplitude of two paths of signals；faFor signal frequency,Respectively two paths of signals initial phase
Position.
Although frequency input signal is it is known that for without loss of generality, by faIt indicates are as follows:
fa=(k0+δ)·fd
k0For integer, fdFor spectral resolution, fd=fs/ N, fsFor sample frequency, N is sampling number, and δ is lobe error system
Number, | δ |≤0.5.
With identical sample frequency fsIn synchronization to s1(n) and s2(n) sampled, thus obtained two-way from
Sequence is dissipated,
N=0,1,2 ..., N-1
Next, because the processing to two-way discrete series is similar, here with s1(n) it is illustrated, to s1(n) DFT change is carried out
Get discrete spectrum S in return1(k), wherein k=0,1,2 ..., N-1.Because of S1(k) peak value spectral line is in k=k0Place obtains, according to
DFT definition, can obtain:
Ignore the negative frequency component in formula, formula can abbreviation are as follows:
If phase1 indicates S1(k) in k=k0The phase at place, then phase1 can be with unified representation are as follows:
Similarly phase2
Phase difference can be obtained
Further, according to formulaThe value of angle of fall α is calculated, L is two receiving antennas in formula
Spacing.
The present invention is described in detail combined with specific embodiments below.
Embodiment
The present embodiment uses following system parameter: sine wave FM system, f0=24G, Δ FM=50MHz, Tm=4us, day
Line spacing L=0.018m, starting distance R=30m, Missile Motion speed v=350m/s preset 30 °~60 ° of angle of fall range.
As shown in Figure 1 and Figure 2, method of the present embodiment based on the linear frequency modulation short-range detecting systematic survey shell angle of fall includes
Following steps:
(1) it is mixed: two-way echo-signal being mixed, difference frequency signal is obtained.
(2) FFT method phase difference detection: being FFT to two-way difference frequency signal first, searches for highest spectral peak, calculates highest spectrum
The phase at peak subtracts each other the phase of gained two-way spectral peak, obtains two-way difference frequency signal phase difference.
(3) angle of fall: the phase difference measured according to step 2 is calculated, the shell angle of fall is calculated.
Fig. 3 is predetermined angle and actual measurement angle contrast's figure, it can be seen that predetermined angle and actual measurement in the case where signal-to-noise ratio is 20dB
The linear variation of angle, Fig. 4 are the measurement error in the case where signal-to-noise ratio is 20dB, and worst error is 0.18 °, and mean error is
0.04°.Fig. 5 is in the case where signal-to-noise ratio is 10dB, and predetermined angle and actual measurement angle contrast's figure, predetermined angle and actual measurement angle are linear
Variation, Fig. 6 are the measurement error in the case where signal-to-noise ratio is 10dB, and worst error is 0.23 °, and mean error is 0.085 °.Fig. 7 be
Signal-to-noise ratio is under 3dB, and predetermined angle and actual measurement angle contrast's figure, predetermined angle and the actual measurement linear variation of angle, Fig. 8 are to believe
It makes an uproar than for the measurement error under 3dB, worst error is 0.23 °, mean error is 0.863 °.It can be seen that the present invention possess it is higher
Angle measurement accuracy and stronger anti-interference.
Claims (4)
1. a kind of method based on the linear frequency modulation short-range detecting systematic survey shell angle of fall, which comprises the steps of:
Mixing: two-way reception signal is mixed, difference frequency signal is obtained；
FFT method phase difference detection: being FFT to two-way difference frequency signal, search for highest spectral peak, calculate the phase of highest spectral peak, will
The phase of gained two-way spectral peak is subtracted each other, and two-way difference frequency signal phase difference is obtained；
It calculates the angle of fall: according to the phase difference measured, calculating the shell angle of fall with phase comparing method.
2. the method according to claim 1 based on the linear frequency modulation short-range detecting systematic survey shell angle of fall, feature exist
In the detailed process of mixing are as follows:
Transmitting signal frequency expression be
The frequency representation formula of echo-signal is at fuse receiving antenna 1
In formula, τ is the delay of echo-signal relative transmission signal, f0For carrier frequency, Δ FMFor modulating bandwidth, TMFor frequency modulation week
Phase,t0For the initial position corresponding time；
Using the π ∫ fdt of relational expression φ=2 of frequency and phase, obtains transmitting signal and the instantaneous phase of reception signal is poor；
Within the single linear frequency modulation period, transmitting signal is found out respectively and receives the instantaneous phase of signal；
WhenWhen, difference frequency signal is in formula area, and the phase expression formula for emitting signal is
WhenWhen, difference frequency signal is in irregular area, emits the phase expression formula of signal are as follows:
Wherein, C is constant；
From the continuity of signal phase:Then
WhenWhen, the phase expression formula for receiving signal is
Then whenWhen, transmitting signal is with the instantaneous phase difference for receiving signal
Δφ1=| φR-φT1|=2 π (τ Δ FMfmt+f0τ-τΔFMfmt0)
Emitting signal with echo-signal is cos (Δ φ by the lower form for being mixed to obtain difference frequency signaln), then the table of difference frequency signal
Up to formula are as follows:
cos(Δφ1)=cos2 π (Δ FMfmτt+f0τ-τΔFMfmt0)
=cos2 π (Δ FMfmτt+f0R/c+f0R1/c-τΔFMfmt0)
Then the received another way signal of antenna 2 obtains the expression formula of difference frequency signal by lower mixing are as follows:
cos(Δφ2)=cos2 π (Δ FMfmτt+f0R/c+f0R2/c-τΔFMfmt0)
Two-way difference frequency signal phase difference is 2f0(R1-R2)/c, R1、R2Respectively receiving antenna 1 and receiving antenna 2 to ground away from
From R is transmitting antenna to the distance on ground, and c is the light velocity, wherein R1-R2=Lsin α, L are antenna spacing, and α is the angle of fall, two-way letter
Number total phase meter be shown as:
For the wavelength for emitting signal.
3. the method according to claim 1 based on the linear frequency modulation short-range detecting systematic survey shell angle of fall, feature exist
In the detailed process of FFT method phase difference detection are as follows:
Two paths of signals is sampled first；
Secondly FFT transform is carried out, their phases at peak value spectral line are then found out according to following formula；
X1(k) and X2It (k) is respectively that two-way difference frequency signal does the sequence obtained after FFT；
imag(X1And real (X (k))1(k)) imaginary part and real part are respectively indicated；
Finally the phase of two paths of signals is subtracted each other and finds out phase difference:
。
4. the method according to claim 3 based on the linear frequency modulation short-range detecting systematic survey shell angle of fall, feature exist
According to formulaThe value of angle of fall α is calculated, L is the spacing of two receiving antennas in formula.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710643908.8A CN109323634A (en) | 2017-07-31 | 2017-07-31 | Method based on the linear frequency modulation short-range detecting systematic survey shell angle of fall |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710643908.8A CN109323634A (en) | 2017-07-31 | 2017-07-31 | Method based on the linear frequency modulation short-range detecting systematic survey shell angle of fall |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN109323634A true CN109323634A (en) | 2019-02-12 |
Family
ID=65245847
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710643908.8A Pending CN109323634A (en) | 2017-07-31 | 2017-07-31 | Method based on the linear frequency modulation short-range detecting systematic survey shell angle of fall |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109323634A (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101504462A (en) * | 2008-02-04 | 2009-08-12 | 深圳市博时雅科技有限公司 | Phase difference detection method and system, double-crystal oscillation mixer circuit and distance measurement apparatus |
| CN105487071A (en) * | 2015-11-23 | 2016-04-13 | 芜湖森思泰克智能科技有限公司 | Multi-moving-object signal processing method based on stepped frequency radar |
-
2017
- 2017-07-31 CN CN201710643908.8A patent/CN109323634A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101504462A (en) * | 2008-02-04 | 2009-08-12 | 深圳市博时雅科技有限公司 | Phase difference detection method and system, double-crystal oscillation mixer circuit and distance measurement apparatus |
| CN105487071A (en) * | 2015-11-23 | 2016-04-13 | 芜湖森思泰克智能科技有限公司 | Multi-moving-object signal processing method based on stepped frequency radar |
Non-Patent Citations (6)
| Title |
|---|
| 周笛: "基于DSP高精度相位差检测系统设计", 《中国优秀硕士学位论文全文数据库 信息科技辑》 * |
| 李益民 等: "靶场连续波测距雷达系统分析", 《飞行器测控学报》 * |
| 涂亚庆 等: "《复杂信号频率估计方法及应用》", 31 August 2016, 北京:国防工业出版社 * |
| 范圆圆: "基于双频调制信号的相位法距离测量研究", 《中国优秀硕士学位论文全文数据库 信息科技辑》 * |
| 蔡玉鑫: "改进型相位式激光测距方法研究", 《中国优秀硕士学位论文全文数据库 信息科技辑》 * |
| 黄亮: "锯齿波调频探测系统信号处理研究与实现", 《中国优秀硕士学位论文全文数据库 信息科技辑》 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109167746B (en) | Continuous wave and pulse signal quick identification device | |
| JP6177467B1 (en) | Radar operation with enhanced Doppler capability | |
| CN101128988A (en) | Method and apparatus for channel estimation to electro-magnetic wave multi path between sender and receiver by using chirp signal | |
| CN101105525A (en) | Pure phase type broad frequency band microwave radiation source direction finding system and method | |
| CN103364783B (en) | Moving target radial velocity non-fuzzy estimation method based on single-channel SAR (synthetic aperture radar) | |
| CN101216549B (en) | Medium-high frequency wave spread-spectrum navigation system distance observed quantity extraction method | |
| CN105676212B (en) | A kind of short range range radar system and the target measuring method based on the system | |
| CN102520410B (en) | High-precision angle measurement method of automotive anti-collision radar based on interference theory | |
| US9568601B1 (en) | Successive-MFCW modulation for ultra-fast narrowband radar | |
| US11428772B2 (en) | Compensating for crosstalk in determination of an angle of arrival of an electromagnetic wave at a receive antenna | |
| CN106154257B (en) | The secondary frequency measuring method of precision instrumentation radar based on FFT and apFFT | |
| CN114217301B (en) | High-precision side slope monitoring radar target detection and distance measurement method | |
| CN106483445B (en) | A kind of built-in measurement method and device of wideband circuit phase nonlinear distortion | |
| US20050078030A1 (en) | Pulse radar apparatus | |
| CN109323634A (en) | Method based on the linear frequency modulation short-range detecting systematic survey shell angle of fall | |
| CN114114302A (en) | LIDAR device using time-delayed local oscillator light and method of operating the same | |
| JP2010281605A (en) | Radar system | |
| CN108983175A (en) | Method based on the continuous wave frequency short-range detecting systematic survey shell angle of fall | |
| GB2540196B (en) | Radar signal processing | |
| CN109387815A (en) | ApFFT composes angle-measuring method in sawtooth phase modulation linear system | |
| Kurniawan et al. | Implementation of automatic I/Q imbalance correction for FMCW radar system | |
| Chen et al. | A frequency estimator for real valued sinusoidal signals using three dft samples | |
| Wang et al. | Time-domain algorithm for FMCW based short distance ranging system | |
| RU2792196C1 (en) | Method for measuring angular coordinates of moving objects with a doppler station | |
| CN117607848B (en) | FDR-based radar positioning and ranging method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20190212 |
|
| RJ01 | Rejection of invention patent application after publication |