CN113281740A - Ultra-wideband Doppler radar life detection system - Google Patents
Ultra-wideband Doppler radar life detection system Download PDFInfo
- Publication number
- CN113281740A CN113281740A CN202110568198.3A CN202110568198A CN113281740A CN 113281740 A CN113281740 A CN 113281740A CN 202110568198 A CN202110568198 A CN 202110568198A CN 113281740 A CN113281740 A CN 113281740A
- Authority
- CN
- China
- Prior art keywords
- signal
- signals
- frequency
- channel
- ultra
- 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
- 238000001514 detection method Methods 0.000 title claims abstract description 83
- 238000012545 processing Methods 0.000 claims abstract description 30
- 238000007405 data analysis Methods 0.000 claims abstract description 6
- 238000000605 extraction Methods 0.000 claims abstract description 5
- 238000007781 pre-processing Methods 0.000 claims abstract description 4
- 238000010183 spectrum analysis Methods 0.000 claims abstract description 4
- 238000002156 mixing Methods 0.000 claims description 12
- 238000001914 filtration Methods 0.000 claims description 11
- 230000003750 conditioning effect Effects 0.000 claims description 9
- 239000013078 crystal Substances 0.000 claims description 6
- 230000003044 adaptive effect Effects 0.000 claims description 4
- 238000009826 distribution Methods 0.000 claims description 3
- 238000007493 shaping process Methods 0.000 claims description 3
- 230000002194 synthesizing effect Effects 0.000 claims description 3
- 239000002131 composite material Substances 0.000 claims description 2
- 230000003321 amplification Effects 0.000 claims 2
- 230000010354 integration Effects 0.000 claims 2
- 238000003199 nucleic acid amplification method Methods 0.000 claims 2
- 238000001228 spectrum Methods 0.000 abstract description 5
- 238000005070 sampling Methods 0.000 abstract description 3
- 230000005012 migration Effects 0.000 abstract description 2
- 238000013508 migration Methods 0.000 abstract description 2
- 238000003384 imaging method Methods 0.000 description 12
- 230000006870 function Effects 0.000 description 10
- 238000000034 method Methods 0.000 description 8
- 238000005516 engineering process Methods 0.000 description 7
- 230000029058 respiratory gaseous exchange Effects 0.000 description 7
- 238000010586 diagram Methods 0.000 description 4
- 230000004888 barrier function Effects 0.000 description 3
- 238000013461 design Methods 0.000 description 3
- 238000006073 displacement reaction Methods 0.000 description 3
- 230000035945 sensitivity Effects 0.000 description 3
- 238000004364 calculation method Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000000149 penetrating effect Effects 0.000 description 2
- 230000001629 suppression Effects 0.000 description 2
- 230000009466 transformation Effects 0.000 description 2
- 235000017166 Bambusa arundinacea Nutrition 0.000 description 1
- 235000017491 Bambusa tulda Nutrition 0.000 description 1
- 241001330002 Bambuseae Species 0.000 description 1
- 235000015334 Phyllostachys viridis Nutrition 0.000 description 1
- 230000006978 adaptation Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 239000011425 bamboo Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 239000011449 brick Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000013500 data storage Methods 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 230000001121 heart beat frequency Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000012880 independent component analysis Methods 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 230000005764 inhibitory process Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000005065 mining Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000011897 real-time detection Methods 0.000 description 1
- 230000036391 respiratory frequency Effects 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 238000011896 sensitive detection Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 230000008054 signal transmission Effects 0.000 description 1
- 230000003595 spectral effect Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 239000013598 vector Substances 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/88—Radar or analogous systems specially adapted for specific applications
- G01S13/887—Radar or analogous systems specially adapted for specific applications for detection of concealed objects, e.g. contraband or weapons
- G01S13/888—Radar or analogous systems specially adapted for specific applications for detection of concealed objects, e.g. contraband or weapons through wall detection
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
- G01S13/88—Radar or analogous systems specially adapted for specific applications
- G01S13/89—Radar or analogous systems specially adapted for specific applications for mapping or imaging
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/41—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00 using analysis of echo signal for target characterisation; Target signature; Target cross-section
- G01S7/411—Identification of targets based on measurements of radar reflectivity
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
- G01S7/41—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00 using analysis of echo signal for target characterisation; Target signature; Target cross-section
- G01S7/414—Discriminating targets with respect to background clutter
Abstract
The invention discloses a life detection system of an ultra-wideband Doppler radar, and belongs to the technical field of radars. The device comprises a transmitting module, a receiving module and a data processing module; the transmitting module and the receiving module keep signal synchronization; the transmitting module is used for transmitting electromagnetic radio frequency signals, the electromagnetic radio frequency signals form echo signals after being modulated by detected life electromagnetic information, the receiving module is used for completing preprocessing of received signals, the data processing module is used for carrying out data analysis on the preprocessed received signals, and spectrum analysis and extraction of the signals are achieved by adopting a weak signal detection mode based on stochastic resonance, so that detection and capture of the weak life electromagnetic information are achieved. For the received weak physiological characteristic signal, a bistable stochastic resonance detection mode of secondary sampling and parameter compensation is adopted, and the frequency spectrum migration and the enhancement processing of the signal to be detected are realized by utilizing the difference of gain characteristics of different frequency components by the bistable stochastic resonance.
Description
Technical Field
The invention belongs to the technical field of radars, and particularly relates to a life detection system of an ultra-wideband Doppler radar.
Background
China is a country with frequent earthquakes, natural disasters and safety production accidents in industrial production occur occasionally, and a large number of trapped people are lost every year due to the fact that the people cannot be timely rescued, so real-time search and rescue on disaster sites become more important, and high requirements are put forward on search and rescue equipment. The disaster site situation is complex, trapped people are often trapped in serious obstacles, the complexity and search and rescue difficulty of the trapped people are very high when the trapped people are found, and how to realize the positioning of the trapped people in a short time is very important for real-time search and rescue.
With the rapid development of sensor technology and information technology, various life detection instruments are developed like bamboo shoots in spring after raining, the life detection instruments are widely applied to disaster area search and rescue, but many devices are insufficient in detection accuracy and reliability. The existing radar life detection system mainly aims at the detection of a long-distance life body, namely, the long-distance non-contact detection of life information such as breath and heartbeat of a human body, but has some key problems to be solved in application, and mainly comprises high-resolution imaging and target vital sign information identification. Because the single-frequency continuous wave signal is stable and can obtain higher signal-to-noise ratio, the continuous wave signal is adopted as the emission signal of a general radar system, but along with the application of the biological detection radar in disaster rescue, the detection instrument is required to have stronger barrier penetrability and carry out two-dimensional imaging, and the continuous wave radar cannot realize the detection. The existing radar life detection system has poor signal anti-interference capability, and because the electromagnetic wave signal of the life detection system has complex components, the radar life detection system not only contains a reflection signal of a life body, but also contains a reflected wave of a wall, environmental noise, background clutter and the like. The vital sign signals are weak, and once interference signals introduced by obstacles such as concrete, brick walls and the like are mixed in echo signals brought by human body perturbation, micro-motion characteristics brought by human body respiration, heartbeat and the like are difficult to distinguish.
The problems of direct wave suppression, wall parameter estimation, multi-path interference between targets and the like exist in the aspect of high-resolution accurate imaging of the life detection radar, meanwhile, strong electromagnetic interference of a detection environment can also influence the detection effect, the detection distance and the detection imaging resolution are not high, and the detection imaging precision is influenced due to the fact that the detection life signal and the environment clutter are fuzzy crossed due to the fact that the detection imaging precision is influenced due to the fact that Doppler frequency and Doppler dispersion existing in the clutter in detection are influenced. The weak target signals are difficult to distinguish due to direct wave suppression and wall echo signals, errors exist between the target position and the actual position in imaging due to the fact that the dielectric constants of a wall and air are different, and the existing detector needs to compensate in imaging after wall parameters are accurately estimated, so that a false target is formed in imaging, and the performance of life detection equipment is affected.
Therefore, the ultra-wideband radar life detection system designed by adopting advanced intelligent hardware and software algorithms has great practical significance for searching and rescuing on disaster sites, and has very important significance for quickly mining and finding human life information from ruins, realizing intelligent searching and rescuing, life information identification, survivor positioning and the like.
Disclosure of Invention
Aiming at the defects of the prior art, the invention aims to provide an ultra-wideband Doppler radar life detection system, aiming at solving the problems of low reliability, poor signal anti-interference capability and low accuracy of the conventional radar life detection system.
In order to achieve the above object, the present invention provides an ultra-wideband doppler radar life detection system, which comprises a transmitting module, a receiving module and a data processing module; the signal source of the transmitting module and the signal source of the receiving module keep signal synchronization through a data synchronization interface; the transmitting module is used for transmitting electromagnetic radio frequency signals, an ultra-wideband radar signal ultrahigh frequency circuit used for detecting the electromagnetic radio frequency signals is used, the duration time of ultra-wideband pulses generated by the pulse generating and receiving module is only a few nanoseconds, the pulse duration time is very short, the ultra-wideband radar signal ultrahigh frequency circuit has very wide penetrating power and detection precision, the electromagnetic radio frequency signals form receiving signals after being modulated by detected life electromagnetic information, the receiving module is used for finishing preprocessing the receiving signals, the data processing module is used for carrying out data analysis on the preprocessed receiving signals, and spectrum analysis and extraction of the signals are realized by adopting a weak signal detection mode based on stochastic resonance, so that the detection and capture of the weak life electromagnetic information are realized.
The transmitting module comprises a first signal source, a function generator, a signal conditioning circuit, a first attenuator, a crystal oscillator, a first low-pass filter, a second attenuator, a first mixer, a first amplifier and a transmitting antenna, wherein the first signal source is used for generating an original transmitting signal; the function generator is used for synthesizing an original transmitting signal and a function signal to generate a signal of a desired type so as to realize flexible adjustment of a transmitting waveform; the signal conditioning circuit is used for conditioning and shaping signals; the first attenuator realizes the attenuation of the signal; the crystal oscillator is used for generating a signal with fixed frequency; the first low-pass filter and the second attenuator sequentially realize the filtering and attenuation of signals; the frequency mixer is used for mixing the signal passing through the first attenuator with the signal passing through the second attenuator to generate a high-frequency signal; the first amplifier is used for amplifying a high-frequency signal; the high-frequency transmitting antenna is used for radiating the high-frequency signal output by the first amplifier.
The receiving module comprises a receiving antenna, a second amplifier, a first power divider, a second signal source, a second frequency mixer, a third frequency mixer, a second low-pass filter, a first amplifying circuit, a third low-pass filter and a second amplifying circuit; the receiving antenna is used for receiving echo signals; the second amplifier is used for amplifying the received signal;
the first power divider is used for realizing power distribution of received signals and dividing the received signals into a first channel and a second channel; the second power divider is used for dividing the signal generated by the second signal source into two paths of orthogonal signals, namely an I channel and a Q channel; the second mixer is used for mixing the first channel and the I channel to generate a frequency-reduced I-channel signal; the third mixer is used for mixing the second channel and the Q channel to generate a frequency-reduced Q-channel signal; the second low-pass filter is used for realizing low-pass filtering of the frequency-reduced I-channel signal; the first amplifying circuit amplifies the frequency-reduced I-channel signal; the third low-pass filter realizes low-pass filtering of the frequency-reduced Q channel signal to remove high-frequency signals and clutter; the second amplifying circuit is used for amplifying the frequency-reduced Q-channel signal.
The data processing module comprises a summation operation unit, an integral operation unit, a cubic operation unit, a first gain unit, a second gain unit, a parameter adjustment control unit and a self-adaptive processing module, wherein two paths of orthogonal signals of the receiving module are synthesized to form an input signal, one path of the output signal passes through the first gain unit, one path of the output signal passes through the cubic operation unit and then passes through the second gain unit, the two paths of the output signal and the input signal pass through the summation operation unit and the integral operation unit to output the output signal, and the self-adaptive processing module adjusts gain parameters of the first gain unit and the second gain unit controlled by the parameter adjustment control unit according to the detected output signal, so that the signal-to-noise ratio of the output signal is maximum, the signal frequency at the moment is extracted, and the characteristic information of the measured life is acquired.
The traditional life detection system is improved by adopting the currently advanced radio frequency technology, information technology and the like. The method comprises the steps of providing a specific electromagnetic information detection and processing scheme for life detection, realizing the software and hardware design of a real-time data acquisition and transmission module of an ultra-wideband radar life detection system by adopting a radio frequency technology and a microprocessor technology, transmitting acquired human physiological electromagnetic information to a data calculation and analysis software system, realizing the detection and real-time search of human life information through the software system, and establishing a search and information sharing platform capable of finishing the human life information according to the acquired electromagnetic data analysis and calculation platform.
The ultra-wideband radar life detection system mainly adopts a high-speed data sensor to acquire data to obtain data representing human life information, and simultaneously designs a biological radar direct wave inhibition and biological radar imaging system. By an independent component analysis method for analyzing ultra-wideband variable frequency biological radar data, the signal is decomposed into a plurality of independent signal components, the interference of direct waves is removed, the non-Gaussian property among the components is strongest, and the detection reliability is improved.
An ultra-wideband frequency conversion life detection system imaging and life body micro Doppler information detection algorithm is designed, and a basic framework is established. The method is characterized in that mathematical modeling is carried out on the ultra-wideband variable-frequency continuous wave biological radar detection vital sign signals, imaging models in different sign information are established, and a distance domain filtering method in ultra-wideband variable-frequency emission signals is adopted to eliminate noise and interference in echo signals, so that the purpose of vital sign detection is achieved. A phasor difference method is designed in a measurement system to remove the inconsistency of the antenna and the inconsistency of each frequency point of antenna parameters, and the setting influence of the stepping frequency interval of the transmitting signal and the bandwidth of a filter at a receiving end is eliminated. The real-time data stream of the detection system is effectively processed, so that the extraction, analysis and state division of the vital electromagnetic information are realized, and the real-time data stream of the detection system is analyzed to realize data identification and real-time assessment of vital signs. Meanwhile, the evaluation result is displayed, network sharing of information is achieved, and the designed ultra-wideband radar life detection system is a system platform integrating real-time monitoring, data analysis and sharing.
If the n-time electromagnetic radio frequency signals generated by the transmitting module are p (t, τ), the echo signals r (t, τ) received by the receiving module are:
wherein p (t) is the received signal, A is the signal amplitude, x (t) is the displacement delay caused by the physiological signals of respiration and heartbeat, d0The distance between the measured life and the receiving antenna, C is the speed of light, mbAnd mhAmplitude of displacement, f, caused by respiration and heartbeat, respectivelybAnd fhRespectively representing the breathing rate and the heart rate. Considering that echo signals are non-stationary, modal decomposition is carried out on the signals after filtering separation to obtain a plurality of intrinsic modal functions, in order to reduce interference of clutter on respiration and heartbeat signals, a stochastic resonance algorithm is adopted to carry out spectrum enhancement processing on the respiration and heartbeat signals, then the signals are reconstructed, and then autocorrelation, spectrum operation and other processing are carried out to finally reconstruct a signal spectrum.
In order to avoid interference of blind spots in detection, the down-conversion technology of an orthogonal structure is adopted to enable two paths of output signals I/Q to always keep a phase difference of 90 degrees, so that a receiving end can be guaranteed to always have one path of signal which is not in the detection blind spot, and accurate demodulation of the signal is facilitated, and the signal can obtain orthogonal receiving signals after I/Q processing, frequency mixing and a low-pass filter, and the output of the orthogonal receiving signals is as follows:
wherein, BI(t) represents the signal after mixing of the received signal and the I-component of the signal source and processing by a low-pass filter, i.e. the down-converted I-channel signal, BQ(t) represents a signal processed by a low-pass filter after the frequency mixing of the receiving signal and the signal source Q component, namely a frequency-reduced Q channel signal, x (t) and delta phi (t) respectively represent displacement and phase difference caused by physiological signals such as respiration and heartbeat, theta is an initial phase, and lambda is the wavelength of the electromagnetic radio-frequency signal.
The digital processing module can be described by the lagrangian equation:
wherein f (B)I(t),BQ(t)) is the composite of the downconverted I-channel signal and the downconverted Q-channel signal, Γ (t) is white Gaussian noise, y (t) is the system output, a and b are the gain parameters, ay (t) -by3(t) is the differential of the potential function.
In order to ensure that the stochastic resonance can furthest improve the signal-to-noise ratio to detect weak physiological signals, the relationship between the signal frequency and the Cleimsen transition rate is ensured to be met in the adjustment of the structural parameters
Wherein f iscFor the signal frequency to be extracted, a and b are gain parameters, and D is the noise intensity. Because the respiratory frequency of the human body is generally between 0.2 and 0.35 Hz, the heartbeat frequency of the human bodyThe frequency scale transformation is adopted for stochastic resonance in order to ensure the sensitivity of the system to low-frequency weak signals, wherein the frequency scale transformation is generally between 0.8 and 2.5 Hz
τ is at, and its frequency adaptation equation is:
wherein the content of the first and second substances,
the signal-to-noise ratio of the system is taken as a parameter for measuring the stochastic resonance of the system to form a self-adaptive stochastic signal detection system, the parameter adjusting and controlling module can automatically adjust an expected parameter and adjust the gain according to the characteristics of an output signal, and the signal-to-noise ratio is as follows:
where S (ω) is a spectral function, ωsAnd (2) for inputting the angular frequency of the signal, delta (omega) is a pulse function, structural parameters of the module are adjusted according to different noise magnitudes, and the gain adjustment process is repeated again to enable the system to generate random resonance, so that the characteristic information of the measured signal is obtained.
Through the technical scheme, compared with the prior art, the invention has the following beneficial effects:
1. the ultra-wideband radar life detection system constructed by the invention can monitor the vital sign signals in a complex use environment, a life detection radar hardware system is designed, and the weak vital sign signals can be extracted through matching of all devices of the radar system, electromagnetic compatibility design and an improved processing algorithm; the received weak physiological characteristic signal is subjected to a bistable stochastic resonance detection mode of secondary sampling and parameter compensation, the spectrum migration and the enhancement processing of the signal to be detected are realized by utilizing the difference of gain characteristics of different frequency components of the bistable stochastic resonance system, and the reliability is high.
2. According to the denoising method for the echo signal of the life detection radar, a core algorithm adopts a nonlinear signal detection method based on a random resonance effect, a double-closed-loop bistable model is adopted in a random resonance mode, a system output signal is fed back to a front end to act together with an input signal, the system can monitor the change trend of an output signal-to-noise ratio, and when the system is in an optimal random resonance state, the output signal-to-noise ratio reaches a maximum value. The system dynamically adjusts the gain value of the feedback system to realize self-adaptive stochastic resonance, so as to realize characteristic capture of signals, combines the characteristics of life detection radar echo signals, adopts a self-adaptive algorithm for adjusting system parameters by changing gain and weight vectors, increases fixed step length from small to large of the system parameters, adjusts sensitivity and signal-to-noise ratio by changing the system parameters to enable the system parameters to reach a stochastic resonance state, can reflect the possibly existing characteristics of multi-frequency periodic signals to the maximum degree, ensures the lower distortion of the signals and improves the signal-to-noise ratio of the detection signals.
3. The vital sign signal detection radar system provided by the invention has higher detection sensitivity, the radar system has more sensitive detection performance when a target is positioned behind a plurality of walls or a barrier exists between the wall and the target, the system can inhibit direct waves under complex conditions and can realize that a biological radar penetrates through a plurality of barriers to image the target, and the accuracy is high.
Drawings
FIG. 1 is an overall block diagram of an ultra-wideband Doppler radar life detection system;
FIG. 2 is a schematic diagram of a detection system signal transmission module;
FIG. 3 is a schematic diagram of a detection system signal receiving module;
FIG. 4 is a schematic diagram of a detection system signal data processing module;
FIG. 5 is a flow chart of the stochastic resonance processing and reconstruction of the detection system signals.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.
As shown in fig. 1, the present invention provides an ultra-wideband doppler radar life detection system, which includes a transmitting module, a receiving module and a data processing module; the signal source of the transmitting module and the signal source of the receiving module keep signal synchronization through a data synchronization interface; the transmitting module is used for transmitting electromagnetic radio frequency signals, an ultra-wideband radar signal ultrahigh frequency circuit used for detecting the electromagnetic radio frequency signals is used, the duration time of ultra-wideband pulses generated by the pulse generating and receiving module is only a few nanoseconds, the pulse duration time is very short, the ultra-wideband radar signal ultrahigh frequency circuit has very wide penetrating power and detection precision, the electromagnetic radio frequency signals form receiving signals after being modulated by detected life electromagnetic information, the receiving module is used for finishing preprocessing the receiving signals, the data processing module is used for carrying out data analysis on the preprocessed receiving signals, and spectrum analysis and extraction of the signals are realized by adopting a weak signal detection mode based on stochastic resonance, so that the detection and capture of the weak life electromagnetic information are realized.
As shown in fig. 2, the transmitting module includes a first signal source, a function generator, a signal conditioning circuit, a first attenuator, a crystal oscillator, a first low-pass filter, a second attenuator, a first mixer, a first amplifier, and a transmitting antenna, where the first signal source is used to generate an original transmitting signal; the function generator is used for synthesizing an original transmitting signal and a function signal to generate a signal of a desired type so as to realize flexible adjustment of a transmitting waveform; the signal conditioning circuit is used for conditioning and shaping signals; the first attenuator realizes the attenuation of the signal; the crystal oscillator is used for generating a signal with fixed frequency; the first low-pass filter and the second attenuator sequentially realize the filtering and attenuation of signals; the frequency mixer is used for mixing the signal passing through the first attenuator with the signal passing through the second attenuator to generate a high-frequency signal; the first amplifier is used for amplifying a high-frequency signal; the high-frequency transmitting antenna is used for radiating the high-frequency signal output by the first amplifier.
As shown in fig. 3, the receiving module includes a receiving antenna, a second amplifier, a first power divider, a second signal source, a second mixer, a third mixer, a second low-pass filter, a first amplifying circuit, a third low-pass filter, and a second amplifying circuit; the receiving antenna is used for receiving echo signals; the second amplifier is used for amplifying the received signal;
the first power divider is used for realizing power distribution of received signals and dividing the received signals into a first channel and a second channel; the second power divider is used for dividing the signal generated by the second signal source into two paths of orthogonal signals, namely an I channel and a Q channel; the second mixer is used for mixing the first channel and the I channel to generate a frequency-reduced I-channel signal; the third mixer is used for mixing the second channel and the Q channel to generate a frequency-reduced Q-channel signal; the second low-pass filter is used for realizing low-pass filtering of the frequency-reduced I-channel signal; the first amplifying circuit amplifies the frequency-reduced I-channel signal; the third low-pass filter realizes low-pass filtering of the frequency-reduced Q channel signal to remove high-frequency signals and clutter; the second amplifying circuit is used for amplifying the frequency-reduced Q-channel signal.
As shown in fig. 4, the data processing module includes a summation operation unit, an integral operation unit, a cubic operation unit, a first gain unit, a second gain unit, a parameter adjustment control unit, and an adaptive processing module, wherein two paths of orthogonal signals of the receiving module are synthesized to form an input signal, one path of the output signal passes through the first gain unit, one path of the output signal passes through the cubic operation unit and then passes through the second gain unit, two paths of the output signal and the input signal pass through the summation operation unit and the integral operation unit and then output an output signal, the adaptive processing module adjusts gain parameters of the first gain unit and the second gain unit controlled by the parameter adjustment control unit according to the detected output signal, the signal-to-noise ratio of the output signal is maximized, and the signal frequency at the moment is extracted, so that the characteristic information of the measured life is obtained. The specific flow is shown in fig. 5.
The main modules of the method achieve the following technical indexes:
1. high-frequency antenna and sensor: the frequency range is 1-6 GHz;
2. the data sampling rate reaches 1 GS/s;
3. a data storage module: the capacity of the memory of the large-capacity memory chip reaches 4GB, and the working voltage is 1.5V;
4. the high-speed data acquisition board and the data processing terminal adopt PCI or Ethernet interfaces to realize data exchange;
5. the real-time detection of human body vital sign information can be realized, the detection wall penetration depth of the detection system is 2 meters, and the detection distance is 30 meters.
It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.
Claims (7)
1. The ultra-wideband Doppler radar life detection system is characterized by comprising a transmitting module, a receiving module and a data processing module; the transmitting module and the receiving module keep signal synchronization; the transmitting module is used for transmitting electromagnetic radio frequency signals, the electromagnetic radio frequency signals form echo signals after being modulated by detected life electromagnetic information, the receiving module is used for completing preprocessing of received echo signals, the data processing module is used for carrying out data analysis on the preprocessed received signals, and spectrum analysis and extraction of the signals are achieved through a weak signal detection mode based on stochastic resonance, so that detection and capture of the weak life electromagnetic information are achieved.
2. The ultra-wideband doppler radar life detection system of claim 1 wherein the transmit module comprises a first signal source for generating an original transmit signal, a function generator, a signal conditioning circuit, a first attenuator, a crystal oscillator, a first low pass filter, a second attenuator, a first mixer, a first amplifier, and a transmit antenna; the function generator is used for synthesizing an original transmitting signal and a function signal to generate a signal of a desired type; the signal conditioning circuit is used for conditioning and shaping signals; the first attenuator realizes the attenuation of the signal; the crystal oscillator is used for generating a signal with fixed frequency; the first low-pass filter and the second attenuator sequentially realize the filtering and attenuation of signals; the frequency mixer is used for mixing the signal passing through the first attenuator with the signal passing through the second attenuator to generate an electromagnetic radio frequency signal; the first amplifier is used for amplifying a high-frequency signal; the high-frequency transmitting antenna is used for radiating the electromagnetic radio-frequency signal output by the first amplifier.
3. The ultra-wideband doppler radar life detection system of claim 1 wherein the receive module comprises a receive antenna, a second amplifier, a first power divider, a second signal source, a second power divider, a second mixer, a third mixer, a second low pass filter, a first amplification circuit, a third low pass filter, a second amplification circuit; the receiving antenna is used for receiving echo signals; the second amplifier is used for amplifying the received echo signal;
the first power divider is used for realizing power distribution of received echo signals and dividing the received echo signals into a first channel and a second channel; the second power divider is used for dividing the signal generated by the second signal source into two paths of orthogonal signals, namely an I channel and a Q channel; the second mixer is used for mixing the first channel and the I channel to generate a frequency-reduced I-channel signal; the third mixer is used for mixing the second channel and the Q channel to generate a frequency-reduced Q-channel signal; the second low-pass filter is used for realizing low-pass filtering of the frequency-reduced I-channel signal; the first amplifying circuit amplifies the frequency-reduced I-channel signal; the third low-pass filter realizes low-pass filtering of the frequency-reduced Q-channel signal; the second amplifying circuit is used for amplifying the frequency-reduced Q-channel signal.
4. The ultra-wideband doppler radar life detection system of claim 1, wherein the data processing module comprises a summation unit, an integration unit, a cubic unit, a first gain unit, a second gain unit, a parameter adjustment control unit, and an adaptive processing module, wherein two paths of orthogonal signals of the receiving module are combined to form an input signal, one path of output signal passes through the first gain unit, one path of output signal passes through the cubic unit and then passes through the second gain unit, two paths of output signals and the input signal pass through the summation unit and the integration unit and then output signals, the adaptive processing module adjusts gain parameters of the first gain unit and the second gain unit controlled by the parameter adjustment control unit according to the detected output signal, so as to maximize the signal-to-noise ratio of the output signal, and extracting the signal frequency at the moment so as to obtain the characteristic information of the measured life.
5. The ultra-wideband doppler radar life detection system of claim 1, wherein the data processing module is described by the equation of lewy:
wherein f (B)I(t),BQ(t)) is the composite of the down-converted I-channel signal and the down-converted Q-channel signal, Γ (t) is white Gaussian noise, y (t) is the system output, and a and b are the gain parameters of the first gain unit and the second gain unit, respectively.
6. The ultra wideband doppler radar life detection system of claim 5 wherein the gain parameters a and b of the first gain element and the second gain element are scaled in the same ratio.
7. The ultra wideband doppler radar life detection system of claim 5 wherein the signal to noise ratio is:
where SNR (ω) is the signal-to-noise ratio, ωsFor the input signal angular frequency, δ (ω) is the impulse function and D is the noise intensity.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110568198.3A CN113281740A (en) | 2021-05-25 | 2021-05-25 | Ultra-wideband Doppler radar life detection system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110568198.3A CN113281740A (en) | 2021-05-25 | 2021-05-25 | Ultra-wideband Doppler radar life detection system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113281740A true CN113281740A (en) | 2021-08-20 |
Family
ID=77281201
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110568198.3A Pending CN113281740A (en) | 2021-05-25 | 2021-05-25 | Ultra-wideband Doppler radar life detection system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113281740A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114167504A (en) * | 2021-11-01 | 2022-03-11 | 上海卓菡科技有限公司 | Detector power supply control method, device and system, electronic equipment and storage medium |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102967759A (en) * | 2012-11-22 | 2013-03-13 | 杭州电子科技大学 | Weak signal detection circuit based on chaotic oscillator |
| CN104765031A (en) * | 2015-03-02 | 2015-07-08 | 太原理工大学 | Ultra-wide bandwidth microwave chaos life detection radar device |
| CN106405542A (en) * | 2016-10-10 | 2017-02-15 | 康佳集团股份有限公司 | Life sign detection processing method and system based on continuous waves, and life detector |
| CN109738885A (en) * | 2019-02-25 | 2019-05-10 | 太原理工大学 | A kind of life detection radar system and method based on random code modulated sinusoid signal |
-
2021
- 2021-05-25 CN CN202110568198.3A patent/CN113281740A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102967759A (en) * | 2012-11-22 | 2013-03-13 | 杭州电子科技大学 | Weak signal detection circuit based on chaotic oscillator |
| CN104765031A (en) * | 2015-03-02 | 2015-07-08 | 太原理工大学 | Ultra-wide bandwidth microwave chaos life detection radar device |
| CN106405542A (en) * | 2016-10-10 | 2017-02-15 | 康佳集团股份有限公司 | Life sign detection processing method and system based on continuous waves, and life detector |
| CN109738885A (en) * | 2019-02-25 | 2019-05-10 | 太原理工大学 | A kind of life detection radar system and method based on random code modulated sinusoid signal |
Non-Patent Citations (3)
| Title |
|---|
| 行鸿彦, 卢春霞, 张强: "自适应随机共振微弱信号检测", 系统仿真学报, vol. 30, no. 2, pages 587 - 604 * |
| 贾兰芳 等: "随机共振在生命信号检测中的应用", 通信技术, vol. 45, no. 10, pages 75 - 77 * |
| 郝静，杜太行, 等: "调参随机共振在超高频微弱信号检测中标的应用", 计算机应用, vol. 36, no. 9, pages 2374 - 2380 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114167504A (en) * | 2021-11-01 | 2022-03-11 | 上海卓菡科技有限公司 | Detector power supply control method, device and system, electronic equipment and storage medium |
| CN114167504B (en) * | 2021-11-01 | 2024-02-20 | 北京龙智数科科技服务有限公司 | Detector power supply control method, device and system, electronic equipment and storage medium |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106821347B (en) | FMCW broadband life detection radar respiration and heartbeat signal extraction algorithm | |
| Ding et al. | Noncontact multiple targets vital sign detection based on VMD algorithm | |
| WO2008001092A2 (en) | Radar for through wall detection | |
| US20060290561A1 (en) | System and method for measuring characteristics of a continuous medium and/or localized targets using multiple sensors | |
| US7239983B2 (en) | System and method for measuring characteristics of continuous media and/or localized targets using at least one multi-frequency sensor | |
| CN108387892A (en) | Structural healthy monitoring system based on fmcw radar and method | |
| Li et al. | A new method for non-line-of-sight vital sign monitoring based on developed adaptive line enhancer using low centre frequency UWB radar | |
| Kumawat et al. | Approaching/receding target detection using cw radar | |
| CN109738885B (en) | Life detection radar system and method based on random code modulation sine wave signals | |
| CN111505631A (en) | Heart rate estimation algorithm based on L FMCW radar | |
| Yan et al. | Through-the-wall human respiration detection using impulse ultra-wide-band radar | |
| CN113281740A (en) | Ultra-wideband Doppler radar life detection system | |
| US20070013579A1 (en) | Methods and apparatus for target radial extent determination using deconvolution | |
| Vela et al. | Noise radar tomography | |
| Gambi et al. | People movement analysis with automotive radar | |
| CN116087935A (en) | Three-dimensional positioning and identity recognition method and system based on millimeter wave radar | |
| CN114994669A (en) | Radar detection imaging system and power transmission line corona discharge monitoring method thereof | |
| CN115792884A (en) | Personnel detection system and method based on FMCW radar | |
| CN113940660A (en) | Method for detecting respiratory frequency and respiratory volume by radar based on complex signal adjustment | |
| CN112834994A (en) | Millimeter wave radar short-range detection signal detection system for smart car | |
| Abdul-Atty et al. | Hardware Implementation of a Human Movement Detection FMCW Radar | |
| Wang et al. | Research on hand gesture recognition based on millimeter wave radar | |
| Sammartino et al. | Space and frequency diversity for moving personnel spectrogram estimation | |
| Aardal et al. | Radar cross section of the human heartbeat and respiration | |
| Qu et al. | Vital Sign Detection of FMCW Radar Based on Improved Adaptive Parameter Variational Mode Decomposition |
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 |